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10,778,985 | ACCEPTED | Bicyclic heterocycles, pharmaceutical compositions containing these compounds, their use and processes for preparing them | The present invention relates to bicyclic heterocycles of general formula wherein Ra, Rb, Rc, Rd, Re and X are defined as in claim 1, the tautomers, the stereoisomers, the mixtures thereof and the salts thereof, particularly the physiologically acceptable salts thereof with inorganic or organic acids, which have valuable pharmacological properties, particularly an inhibitory effect on signal transduction mediated by tyrosine kinases, the use thereof for treating diseases, particularly tumoral diseases and benign prostatic hyperplasia (BPH), diseases of the lungs and respiratory tract, and the preparation thereof. | 1. A bicyclic heterocycle of formula wherein Ra denotes a hydrogen atom or a C1-4-alkyl group, Rb denotes a phenyl, benzyl or 1-phenylethyl group, wherein the phenyl nucleus in each case is substituted by the groups R1 to R3, while R1 and R2, which may be identical or different, in each case denote a hydrogen, fluorine, chlorine, bromine or iodine atom, a C1-4-alkyl, hydroxy, C1-4-alkoxy, C2-3-alkenyl or C2-3-alkynyl group, an aryl, aryloxy, arylmethyl or arylmethoxy group, a heteroaryl, heteroaryloxy, heteroarylmethyl or heteroarylmethoxy group, a methyl or methoxy group substituted by 1 to 3 fluorine atoms or a cyano, nitro or amino group, and R3 denotes a hydrogen, fluorine, chlorine or bromine atom, a methyl or trifluoromethyl group, Rc denotes a hydrogen atom or a fluorine, chlorine or bromine atom, a hydroxy or C1-4-alkyloxy group, a methoxy group substituted by 1 to 3 fluorine atoms, an ethyloxy group substituted by 1 to 5 fluorine atoms, a C2-4-alkyloxy group which is substituted by a group R4, while R4 denotes a hydroxy, C1-3-alkyloxy, C3-6-cycloalkyloxy, C3-6-cycloalkyl-C1-3-alkyloxy, amino, C1-3-alkylamino, di-(C1-3-alkyl)amino, bis-(2-C1-3-alkyloxy-ethyl)-amino, bis-(3-C1-3-alkyloxy-propyl)-amino, pyrrolidin-1-yl, piperidin-1-yl, homopiperidin-1-yl, morpholin-4-yl, homomorpholin-4-yl, piperazin-1-yl, 4-(C1-3-alkyl)-piperazin-1-yl, homopiperazin-1-yl or 4-(C1-3-alkyl)-homopiperazin-1-yl group, a C3-7-cycloalkyloxy or C3-7-cycloalkyl-C1-4-alkyloxy group, a tetrahydrofuran-3-yloxy, tetrahydropyran-3-yloxy or tetrahydropyran-4-yloxy group, a tetrahydrofuranyl-C1-4-alkyloxy or tetrahydropyranyl-C1-4-alkyloxy group, a pyrrolidin-3-yloxy, piperidin-3-yloxy or piperidin-4-yloxy group, a 1-(C1-3-alkyl)-pyrrolidin-3-yloxy, 1-(C1-3-alkyl)-piperidin-3-yloxy or 1-(C1-3-alkyl)-piperidin-4-yloxy group, a C1-4-alkoxy group which is substituted by a pyrrolidinyl, piperidinyl or homopiperidinyl group substituted in the 1 position by the group R5, where R5 denotes a hydrogen atom or a C1-3-alkyl group, or a C1-4-alkoxy group which is substituted by a morpholinyl or homomorpholinyl group substituted in the 4 position by the group R5, where R5 is as hereinbefore defined, Re and Rd, which may be identical or different, in each case denote a hydrogen atom or a C1-3-alkyl group and X denotes a methyne group substituted by a cyano group or a nitrogen atom, while by the aryl groups mentioned in the definition of the above groups is meant in each case a phenyl group which is mono- or disubstituted by R6, while the substituents may be identical or different and R6 denotes a hydrogen atom, a fluorine, chlorine, bromine or iodine atom or a C1-3-alkyl, hydroxy, C1-3-alkyloxy, difluoromethyl, trifluoromethyl, difluoromethoxy, trifluoromethoxy or cyano group, by the heteroaryl groups mentioned in the definition of the above groups is meant a pyridinyl, pyridazinyl, pyrimidinyl or pyrazinyl group, while the above-mentioned heteroaryl groups are mono- or disubstituted in each case by the group R6, while the substituents may be identical or different and R6 is as hereinbefore defined, and unless otherwise stated, the above-mentioned alkyl groups may be straight-chain or branched, a tautomer or a stereoisomer thereof, or a mixture of such thereof, or a salt thereof. 2. The bicyclic heterocycle of formula I according to claim 1, wherein Ra denotes a hydrogen atom, Rb denotes a phenyl group substituted by the groups R1 to R3, while R1 denotes a hydrogen, fluorine, chlorine or bromine atom, a methyl, trifluoromethyl or ethynyl group, a phenyloxy or phenylmethoxy group, while the phenyl moiety of the above-mentioned groups is optionally substituted by a fluorine or chlorine atom, or a pyridinyloxy or pyridinylmethoxy group, while the pyridinyl moiety of the above-mentioned groups is optionally substituted by a methyl or trifluoromethyl group, R2 denotes a hydrogen, fluorine or chlorine atom and R3 denotes a hydrogen atom, Rc denotes a hydrogen atom, a C1-3-alkyloxy group, a C4-6-cycloalkyloxy or C3-6-cycloalkyl-C1-2-alkyloxy group, a tetrahydrofuran-3-yloxy, tetrahydropyran-3-yloxy, tetrahydropyran-4-yloxy, tetrahydrofuranyl-C1-2-alkyloxy or tetrahydropyranyl-C1-2-alkyloxy group, an ethyloxy group which is substituted in the 2 position by a group R4, where R4 denotes a hydroxy, C1-3-alkyloxy, amino, C1-3-alkylamino, di-(C1-3-alkyl)amino, bis-(2-methoxyethyl)-amino, pyrrolidin-1-yl, piperidin-1-yl, homopiperidin-1-yl, morpholin-4-yl, homomorpholin-4-yl, piperazin-1-yl, 4-(C1-3-alkyl)-piperazin-1-yl, homopiperazin-1-yl or 4-(C1-3-alkyl)-homopiperazin-1-yl group, a propyloxy group which is substituted by a group R4 in the 3 position, while R4 is as hereinbefore defined, or a butyloxy group which is substituted by a group R4 in the 4 position, while R4 is as hereinbefore defined, Re and Rd, which may be identical or different, in each case denote a hydrogen atom or a methyl group and X denotes a nitrogen atom, while, unless otherwise stated, the above-mentioned alkyl groups may be straight-chain or branched, a tautomer or a stereoisomer thereof, or a mixture of such thereof, or a salt thereof. 3. The bicyclic heterocycle of formula I according to claim 1, wherein Ra denotes a hydrogen atom, Rb denotes a 3-ethynylphenyl, 3-bromophenyl, 3,4-difluorophenyl or 3-chloro-4-fluoro-phenyl group, Rc denotes a hydrogen atom, a methoxy, ethyloxy, 2-(methoxy)ethyloxy, 3-(morpholin-4-yl)propyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy, cyclopropylmethoxy, cyclopentylmethoxy, tetrahydrofuran-3-yloxy, tetrahydropyran-3-yloxy, tetrahydropyran-4-yloxy, tetrahydrofuran-2-yl methoxy, tetrahydrofuran-3-ylmethoxy or tetrahydropyran-4-yl-methoxy group, Re and Rd in each case denote a hydrogen atom and X denotes a nitrogen atom, a tautomer or a stereoisomer thereof, a mixture of such thereof, or a salt thereof. 4. The bicyclic heterocycle of formula I according to claim 1, wherein Ra denotes a hydrogen atom, Rb denotes a 3-chloro-4-fluoro-phenyl group, Rc denotes a tetrahydrofuran-3-yloxy group, Re and Rd in each case denote a hydrogen atom and X denotes a nitrogen atom, a tautomer or a stereoisomer thereof, or a mixture of such thereof or a salt thereof. 5. The following compound of formula I according to claim 1: 4-[(3-chloro-4-fluoro-phenyl)amino]-6-{[4-(homomorpholin-4-yl)-1-oxo-2-buten-1-yl]amino}-7-[(S)-(tetrahydrofuran-3-yl)oxy]-quinazoline or a salt thereof. 6. The physiologically acceptable salt of a compound according to claim 1 with an inorganic or organic acid, or a mixture thereof, or a base. 7. A pharmaceutical composition comprising a compound according to claim 1 or a physiologically acceptable salt thereof and one or more inert carriers and/or diluents. 8. A method for treating in a warm-blooded animal which comprises administering to said animal a therapeutically effective amount of a compound according to claim 1. 9. A method for preventing or treating diseases of the airways and lungs in a warm-blooded animal which comprises administering to said animal a therapeutically effective amount of a compound according to claim 1. 10. A method for treating diseases of the gastrointestinal tract or bile duct or gall bladder in a warm-blooded animal which comprises administering to said animal a therapeutically effective amount of a compound according to claim 1. | The present invention relates to bicyclic heterocycles of general formula the tautomers, the stereoisomers, the mixtures thereof and the salts thereof, particularly the physiologically acceptable salts thereof with inorganic or organic acids, which have valuable pharmacological properties, particularly an inhibitory effect on signal transduction mediated by tyrosine kinases, the use thereof for treating diseases, particularly tumoral diseases and benign prostatic hyperplasia (BPH), diseases of the lungs and respiratory tract, and the preparation thereof. In the above general formula I Ra denotes a hydrogen atom or a C1-4-alkyl group, Rb denotes a phenyl, benzyl or 1-phenylethyl group, wherein the phenyl nucleus in each case is substituted by the groups R1 to R3, while R1 and R2, which may be identical or different, in each case denote a hydrogen, fluorine, chlorine, bromine or iodine atom, a C1-4-alkyl, hydroxy, C1-4-alkoxy, C2-3-alkenyl or C2-3-alkynyl group, an aryl, aryloxy, arylmethyl or arylmethoxy group, a heteroaryl, heteroaryloxy, heteroarylmethyl or heteroarylmethoxy group, a methyl or methoxy group substituted by 1 to 3 fluorine atoms or a cyano, nitro or amino group, and R3 denotes a hydrogen, fluorine, chlorine or bromine atom, a methyl or trifluoromethyl group, Rc denotes a hydrogen atom or a fluorine, chlorine or bromine atom, a hydroxy or C1-4-alkyloxy group, a methoxy group substituted by 1 to 3 fluorine atoms, an ethyloxy group substituted by 1 to 5 fluorine atoms, a C2-4-alkyloxy group which is substituted by a group R4, while R4 denotes a hydroxy, C1-3-alkyloxy, C3-6-cycloalkyloxy, C3-6-cycloalkyl-C1-3-alkyloxy, amino, C1-3-alkylamino, di-(C1-3-alkyl)amino, bis-(2-C1-3-alkyloxy-ethyl)-amino, bis-(3-C1-3-alkyloxy-propyl)-amino, pyrrolidin-1-yl, piperidin-1-yl, homopiperidin-1-yl, morpholin-4-yl, homomorpholin-4-yl, piperazin-1-yl, 4-(C1-3-alkyl)-piperazin-1-yl, homopiperazin-1-yl or 4-(C1-3-alkyl)-homopiperazin-1-yl group, a C3-7-cycloalkyloxy or C3-7-cycloalkyl-C1-4-alkyloxy group, a tetrahydrofuran-3-yloxy, tetrahydropyran-3-yloxy or tetrahydropyran-4-yloxy group, a tetrahydrofuranyl-C1-4-alkyloxy or tetrahydropyranyl-C1-4-alkyloxy group, a pyrrolidin-3-yloxy, piperidin-3-yloxy or piperidin-4-yloxy group, a 1-(C1-3-alkyl)-pyrrolidin-3-yloxy, 1-(C1-3-alkyl)-piperidin-3-yloxy or 1-(C1-3-alkyl)-piperidin-4-yloxy group, a C1-4-alkoxy group which is substituted by a pyrrolidinyl, piperidinyl or homopiperidinyl group substituted in the 1 position by the group R5, where R5 denotes a hydrogen atom or a C1-3-alkyl group, or a C1-4-alkoxy group which is substituted by a morpholinyl or homomorpholinyl group substituted in the 4 position by the group R5, where R5 is as hereinbefore defined, Re and Rd, which may be identical or different, in each case denote a hydrogen atom or a C1-3-alkyl group and X denotes a methyne group substituted by a cyano group or a nitrogen atom, while by the aryl groups mentioned in the definition of the above groups is meant pin each case a phenyl group which is mono- or disubstituted by R6, while the substituents may be identical or different and R6 denotes a hydrogen atom, a fluorine, chlorine, bromine or iodine atom or a C1-3-alkyl, hydroxy, C1-3-alkyloxy, difluoromethyl, trifluoromethyl, difluoromethoxy, trifluoromethoxy or cyano group, by the heteroaryl groups mentioned in the definition of the above groups is meant a pyridinyl, pyridazinyl, pyrimidinyl or pyrazinyl group, while the above-mentioned heteroaryl groups are mono- or disubstituted in each case by the group R6, while the substituents may be identical or different and R6 is as hereinbefore defined, and unless otherwise stated, the above-mentioned alkyl groups may be straight-chain or branched. Preferred compounds of the above general formula I are those wherein Ra denotes a hydrogen atom, Rb denotes a phenyl group substituted by the groups R1 to R3, while R1 denotes a hydrogen, fluorine, chlorine or bromine atom, a methyl, trifluoromethyl or ethynyl group, a phenyloxy or phenylmethoxy group, while the phenyl moiety of the above-mentioned groups is optionally substituted by a fluorine or chlorine atom, or a pyridinyloxy or pyridinylmethoxy group, while the pyridinyl moiety of the above-mentioned groups is optionally substituted by a methyl or trifluoromethyl group, R2denotes a hydrogen, fluorine or chlorine atom and R3 denotes a hydrogen atom, Rc denotes a hydrogen atom, a C1-3-alkyloxy group, a C4-6-cycloalkyloxy or C3-6-cycloalkyl-C1-2-alkyloxy group, a tetrahydrofuran-3-yloxy, tetrahydropyran-3-yloxy, tetrahydropyran-4-yloxy, tetrahydrofuranyl-C1-2-alkyloxy or tetrahydropyranyl-C1-2-alkyloxy group, an ethyloxy group which is substituted in the 2 position by a group R4, where R4 denotes a hydroxy, C1-3-alkyloxy, amino, C1-3-alkylamino, di-(C1-3-alkyl)amino, bis-(2-methoxyethyl)-amino, pyrrolid in-1-yl, piperidin-1-yl, homopiperidin-1-yl, morpholin-4-yl, homomorpholin-4-yl, piperazin-1-yl, 4-(C1-3-alkyl)-piperazin-1-yl, homopiperazin-1-yl or 4-(C1-3-alkyl)-homopiperazin-1-yl group, a propyloxy group which is substituted by a group R4 in the 3 position, while R4 is as hereinbefore defined, or a butyloxy group which is substituted by a group R4 in the 4 position, while R4 is as hereinbefore defined, Re and Rd, which may be identical or different, in each case denote a hydrogen atom or a methyl group and X denotes a nitrogen atom, while, unless otherwise stated, the above-mentioned alkyl groups may be straight-chain or branched, the tautomers, their stereoisomers, the mixtures thereof and the salts thereof. Particularly preferred compounds of the above general formula I are those wherein Ra denotes a hydrogen atom, Rb denotes a 3-ethynylphenyl, 3-bromophenyl, 3,4-difluorophenyl or 3-chloro-4-fluoro-phenyl group, Rc denotes a hydrogen atom, a methoxy, ethyloxy, 2-(methoxy)ethyloxy, 3-(morpholin-4-yl)propyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy, cyclopropylmethoxy, cyclopentylmethoxy, tetrahydrofuran-3-yloxy, tetrahydropyran-3-yloxy, tetrahydropyran-4-yloxy, tetrahydrofuran-2-ylmethoxy, tetrahydrofuran-3-ylmethoxy or tetrahydropyran-4-yl-methoxy group, Re and Rd in each case denote a hydrogen atom and X denotes a nitrogen atom, the tautomers, their stereoisomers, the mixtures thereof and the salts thereof. Most particularly preferred compounds of general formula I are those wherein Ra denotes a hydrogen atom, Rb denotes a 3-chloro-4-fluoro-phenyl group, Rc denotes a tetrahydrofuran-3-yloxy group, Re and Rd in each case denote a hydrogen atom and X denotes a nitrogen atom, the tautomers, their stereoisomers, the mixtures thereof and the salts thereof. The following particularly preferred compound of general formula I is mentioned by way of example: 4-[(3-chloro-4-fluoro-phenyl)amino]-6-{[4-(homomorpholin-4-yl)-1-oxo-2-buten-1-yl]amino}-7-[(S)-(tetrahydrofuran-3-yl)oxy]-quinazoline and the salts thereof. The compounds of general formula I may be prepared by the following methods, for example: a) reacting a compound of general formula wherein Ra, Rb, Rc and X are as hereinbefore defined and R7 and R8, which may be identical or different, denote C1-4-alkyl groups, with a compound of general formula wherein Rd and Re are as hereinbefore defined. The reaction is expediently carried out in a solvent or mixture of solvents such as tetrahydrofuran, tetrahydrofuran/water, acetonitrile, acetonitrile/water, dioxane, ethyleneglycol dimethyl ether, isopropanol, methylene chloride, dimethylformamide or sulpholane, optionally in the presence of an inorganic or organic base, e.g. sodium carbonate, potassium hydroxide or 1,8-diazabicyclo[5.4.0]undec-7-ene and optionally in the presence of a lithium salt such as lithium chloride at temperatures between −50 and 150° C., but preferably at temperatures between −20 and 80° C. The reaction may also be carried out with a reactive derivative of the compound of general formula II, for example the hydrate or a hemiacetal. b) reacting a compound of general formula wherein Ra, Rb, Rc and X are as hereinbefore defined and Z1 denotes a leaving group such as a halogen atom or a substituted sulphonyloxy group such as a chlorine or bromine atom, a methanesulphonyloxy or p-toluenesulphonyloxy group, with a compound of general formula wherein Rd and Re are as hereinbefore defined. The reaction is expediently carried out in a solvent such as isopropanol, butanol, tetrahydrofuran, dioxane, acetonitrile, dimethylformamide, sulpholane, toluene or methylene chloride or mixtures thereof, optionally in the presence of an inorganic or organic base, e.g. sodium carbonate, potassium carbonate, potassium hydroxide, triethylamine or N-ethyl-diisopropylamine and optionally in the presence of a reaction accelerator such as an alkali metal iodide at temperatures between −20 and 150° C., but preferably at temperatures between 0 and 100° C. The reaction may however also be carried out without a solvent or in an excess of the compound of general formula V used. In the reactions described hereinbefore, any reactive groups present such as hydroxy, amino, alkylamino or imino groups may be protected during the reaction by conventional protecting groups which are cleaved again after the reaction. For example, a protecting group for a hydroxy group may be a trimethylsilyl, acetyl, trityl, benzyl or tetrahydropyranyl group. Protecting groups for an amino, alkylamino or imino group may be a formyl, acetyl, trifluoroacetyl, ethoxycarbonyl, tert. butoxycarbonyl, benzyloxycarbonyl, benzyl, methoxybenzyl or 2,4-dimethoxybenzyl group. Any protecting group used is optionally subsequently cleaved for example by hydrolysis in an aqueous solvent, e.g. in water, isopropanol/water, acetic acid/water, tetrahydrofuran/water or dioxane/water, in the presence of an acid such as trifluoroacetic acid, hydrochloric acid or sulphuric acid or in the presence of an alkali metal base such as sodium hydroxide or potassium hydroxide or aprotically, e.g. in the presence of iodotrimethylsilane, at temperatures between 0 and 120° C., preferably at temperatures between 10 and 100° C. However, a benzyl, methoxybenzyl or benzyloxycarbonyl group is cleaved, for example, hydrogenolytically, e.g. with hydrogen in the presence of a catalyst such as palladium/charcoal in a suitable solvent such as methanol, ethanol, ethyl acetate or glacial acetic acid, optionally with the addition of an acid such as hydrochloric acid at temperatures between 0 and 100° C., but preferably at temperatures between 20 and 60° C., and at a hydrogen pressure of 1 to 7 bar, but preferably 3 to 5 bar. A 2,4-dimethoxybenzyl group, however, is preferably cleaved in trifluoroacetic acid in the presence of anisol. A tert.butyl or tert.butyloxycarbonyl group is preferably cleaved by treating with an acid such as trifluoroacetic acid or hydrochloric acid or by treating with iodotrimethylsilane, optionally using a solvent such as methylene chloride, dioxane, methanol or diethylether. A trifluoroacetyl group is preferably cleaved by treating with an acid such as hydrochloric acid, optionally in the presence of a solvent such as acetic acid at temperatures between 50 and 120° C. or by treating with sodium hydroxide solution optionally in the presence of a solvent such as tetrahydrofuran at temperatures between 0 and 50° C. Moreover, the compounds of general formula I obtained may be resolved into their enantiomers and/or diastereomers, as mentioned hereinbefore. Thus, for example, cis/trans mixtures may be resolved into their cis and trans isomers, and compounds with at least one optically active carbon atom may be separated into their enantiomers. Thus, for example, the cis/trans mixtures may be resolved by chromatography into the cis and trans isomers thereof, the compounds of general formula I obtained which occur as racemates may be separated by methods known per se (cf. Allinger N. L. and Eliel E. L. in “Topics in Stereochemistry”, Vol. 6, Wiley Interscience, 1971) into their optical antipodes and compounds of general formula I with at least 2 asymmetric carbon atoms may be resolved into their diastereomers on the basis of their physical-chemical differences using methods known per se, e.g. by chromatography and/or fractional crystallisation, and, if these compounds are obtained in racemic form, they may subsequently be resolved into the enantiomers as mentioned above. The enantiomers are preferably separated by column separation on chiral phases or by recrystallisation from an optically active solvent or by reacting with an optically active substance which forms salts or derivatives such as e.g. esters or amides with the racemic compound, particularly acids and the activated derivatives or alcohols thereof, and separating the diastereomeric mixture of salts or derivatives thus obtained, e.g. on the basis of their differences in solubility, whilst the free antipodes may be released from the pure diastereomeric salts or derivatives by the action of suitable agents. Optically active acids in common use are e.g. the D- and L-forms of tartaric acid or dibenzoyltartaric acid, di-O-p-tolyltartaric acid, malic acid, mandelic acid, camphorsulphonic acid, glutamic acid, aspartic acid or quinic acid. An optically active alcohol may be for example (+) or (−)-menthol and an optically active acyl group in amides, for example, may be a (+)-or (−)-menthyloxycarbonyl. Furthermore, the compounds of formula I obtained may be converted into the salts thereof, particularly for pharmaceutical use into the physiologically acceptable salts with inorganic or organic acids. Acids which may be used for this purpose include for example hydrochloric acid, hydrobromic acid, sulphuric acid, methanesulphonic acid, phosphoric acid, fumaric acid, succinic acid, lactic acid, citric acid, tartaric acid or maleic acid. As already mentioned hereinbefore, the compounds of general formula I according to the invention and the physiologically acceptable salts thereof have valuable pharmacological properties, particularly an inhibiting effect on signal transduction mediated by the Epidermal Growth Factor receptor (EGF-R), whilst this may be achieved for example by inhibiting ligand bonding, receptor dimerisation or tyrosinekinase itself. It is also possible to block the transmission of signals to components located further downstream. The biological properties of the new compounds were investigated as follows: The inhibition of human EGF-receptor kinase was determined using the cytoplasmatic tyrosine kinase domain (methionine 664 to alanine 1186, based on the sequence published in Nature 309 (1984), 418). To do this, the protein was expressed in Sf9 insect cells as a GST fusion protein using the Baculovirus expression system. The enzyme activity was measured in the presence or absence of the test compounds in serial dilutions. The polymer pEY (4:1) produced by SIGMA was used as the substrate. Biotinylated pEY (bio-pEY) was added as the tracer substrate. Every 100 μl of reaction solution contained 10 μl of the inhibitor in 50% DMSO, 20 μl of the substrate solution (200 mM HEPES pH 7.4, 50 mM magnesium acetate, 2.5 mg/ml of poly(EY), 5 μg/ml of bio-pEY) and 20 μl of enzyme preparation. The enzyme reaction was started by the addition of 50 μl of a 100 μM ATP solution in 10 mM magnesium chloride. The dilution of the enzyme preparation was adjusted so that the incorporation of phosphate into the bio-pEY was linear in terms of time and quantity of enzyme. The enzyme preparation was diluted in 20 mM HEPES pH 7.4, 1 mM EDTA, 130 mM common salt, 0.05% Triton X-100, 1 mM DTT and 10% glycerol. The enzyme assays were carried out at ambient temperature over a period of 30 minutes and were ended by the addition of 50 μl of a stopping solution (250 mM EDTA in 20 mM HEPES pH 7.4). 100 μl were placed on a streptavidin-coated microtitre plate and incubated for 60 minutes at ambient temperature. Then the plate was washed with 200 μl of a washing solution (50 mM Tris, 0.05% Tween 20). After the addition of 100 μl of a HRPO-labelled anti-PY antibody (PY20H Anti-PTyr:HRP produced by Transduction Laboratories, 250 ng/ml) it was incubated for 60 minutes. Then the microtitre plate was washed three times with 200 μl of washing solution. The samples were then combined with 100 μl of a TMB-peroxidase solution (A:B=1:1, Kirkegaard Perry Laboratories). After 10 minutes the reaction was stopped. The extinction was measured at OD450 nm with an ELISA reader. All data points were measured three times. The data were matched using an iterative calculation using an analytical programme for sigmoidal curves (Graph Pad Prism Version 3.0; sigmoid curves, variable pitch). All the iteration data released showed a correlation coefficient of more than 0.9. The maxima and minima of the curves showed a spread of at least a factor of 5. The IC50 (concentration of active substance which inhibits the activity of EGF-receptor kinase by 50%) was determined from the curves. The following results were obtained: Inhibition of EGF- Compound receptor kinase (Example No.) IC50 [nM] 1 1.5 The compounds of general formula I according to the invention thus inhibit signal transduction by tyrosine kinases, as demonstrated by the example of the human EGF receptor, and are therefore useful for treating pathophysiological processes caused by hyperfunction of tyrosine kinases. These are e.g. benign or malignant tumours, particularly tumours of epithelial and neuroepithelial origin, metastasisation and the abnormal proliferation of vascular endothelial cells (neoangiogenesis). The compounds according to the invention are also useful for preventing and treating diseases of the airways and lungs which are accompanied by increased or altered production of mucus caused by stimulation by tyrosine kinases, e.g. in inflammatory diseases of the airways such as chronic bronchitis, chronic obstructive bronchitis, asthma, bronchiectasis, allergic or non-allergic rhinitis or sinusitis, cystic fibrosis, (1-antitrypsin deficiency, or coughs, pulmonary emphysema, pulmonary fibrosis and hyperreactive airways. The compounds are also suitable for treating diseases of the gastrointestinal tract and bile duct and gall bladder which are associated with disrupted activity of the tyrosine kinases, such as may be found e.g. in chronic inflammatory changes such as cholecystitis, Crohn's disease, ulcerative colitis, and ulcers in the gastrointestinal tract or such as may occur in diseases of the gastrointestinal tract which are associated with increased secretions, such as Men6trier's disease, secreting adenomas and protein loss syndrome. In addition, the compounds of general formula I and the physiologically acceptable salts thereof may be used to treat other diseases caused by abnormal function of tyrosine kinases, such as e.g. epidermal hyperproliferation (psoriasis), benign prostatic hyperplasia (BPH), inflammatory processes, diseases of the immune system, hyperproliferation of haematopoietic cells, treatment of nasal polyps, etc. By reason of their biological properties the compounds according to the invention may be used on their own or in conjunction with other pharmacologically active compounds, for example in tumour therapy, in monotherapy or in conjunction with other anti-tumour therapeutic agents, for example in combination with topoisomerase inhibitors (e.g. etoposide), mitosis inhibitors (e.g. vinblastine), compounds which interact with nucleic acids (e.g. cis-platin, cyclophosphamide, adriamycin), hormone antagonists (e.g. tamoxifen), inhibitors of metabolic processes (e.g. 5-FU etc.), cytokines (e.g. interferons), antibodies, etc. For treating respiratory tract diseases, these compounds may be used on their own or in conjunction with other therapeutic agents for the airways, such as substances with a secretolytic (e.g. ambroxol, N-acetylcysteine), broncholytic (e.g. tiotropium or ipratropium or fenoterol, salmeterol, salbutamol) and/or anti-inflammatory activity (e.g. theophylline or glucocorticoids). For treating diseases in the region of the gastrointestinal tract, these compounds may also be administered on their own or in conjunction with substances having an effect on motility or secretion. These combinations may be administered either simultaneously or sequentially. These compounds may be administered either on their own or in conjunction with other active substances by intravenous, subcutaneous, intramuscular, intraperitoneal or intranasal route, by inhalation or transdermally or orally, whilst aerosol formulations are particularly suitable for inhalation. For pharmaceutical use the compounds according to the invention are generally used for warm-blooded vertebrates, particularly humans, in doses of 0.01-100 mg/kg of body weight, preferably 0.1-15 mg/kg. For administration they are formulated with one or more conventional inert carriers and/or diluents, e.g. with corn starch, lactose, glucose, microcrystalline cellulose, magnesium stearate, polyvinylpyrrolidone, citric acid, tartaric acid, water, water/ethanol, water/glycerol, water/sorbitol, water/polyethylene glycol, propylene glycol, stearyl alcohol, carboxymethylcellulose or fatty substances such as hard fat or suitable mixtures thereof in conventional galenic preparations such as plain or coated tablets, capsules, powders, suspensions, solutions, sprays or suppositories. The following Examples are intended to illustrate the present invention without restricting it: Preparation of the Starting Compounds: EXAMPLE I 4-[(3-chloro-4-fluoro-phenyl)amino]-6-[(diethoxy-phosphoryl)-acetylamino]-7-[(S)-(tetrahydrofuran-3-yl)oxy]-quinazoline 60.07 g of diethoxyphosphorylacetic acid are placed in 750 ml of N,N-dimethylformamide and at ambient temperature combined with 48.67 g of N,N′-carbonyldiimidazole. After the development of gas has ceased 90.00 g of 4-[(3-chloro-4-fluoro-phenyl)amino]-6-amino-[(S)-(tetrahydrofuran-3-yl)oxy]-quinazoline are added and the reaction mixture is stirred for about 4-5 hours at ambient temperature until the reaction is complete. The reaction mixture is then heated gently in the water bath and 750 ml of water are added twice. The thick suspension is stirred overnight and the next morning another 350 ml of water are added. The suspension is cooled in the ice bath, stirred for one hour and suction filtered. The filter cake is washed again with 240 ml of N,N-dimethylformamide/water (1:2) and 240 ml of diisopropylether and dried at 40° C. in the circulating air dryer. Yield: 117.30 g of (88 % of theory) Rf value: 0.37 (silica gel, methylene chloride/methanol=9:1) Mass spectrum (ESI+): m/z=553, 555 [M+H]+ The following compounds are obtained analogously to Example I: (1) 4-[(3-chloro-4-fluoro-phenyl)amino]-6-[(diethoxy-phosphoryl)-acetylamino]-7-[(R)-(tetrahydrofuran-3-yl)oxy]-quinazoline Mass spectrum (ESI+): m/z=553, 555 [M+H]+ (2) 4-[(3-chloro-4-fluoro-phenyl)amino]-6-[(diethoxy-phosphoryl)-acetylamino]-7-cyclopropylmethoxy-quinazoline melting point: 185-187° C. (3) 4-[(3-bromophenyl)amino]-6-[(diethoxy-phosphoryl)-acetylamino]-quinazoline Mass spectrum (ESI−): m/z=491, 493 [M−H]− (4) 4-[(3-chloro-4-fluoro-phenyl)amino]-6-[(diethoxy-phosphoryl)-acetylamino]-7-cyclopentyloxy-quinazoline Rf value: 0.54 (silica gel, methylene chloride/ethanol=20:1) EXAMPLE II Homomorpholin-4-yl-acetaldehyde-hydrochloride Prepared by stirring (2.5 hours) 4-(2,2-dimethoxy-ethyl)-homomorpholine with semiconcentrated hydrochloric acid at 80° C. The solution obtained is further reacted directly as in Example 1. EXAMPLE III 4-(2,2-dimethoxy-ethyl)-homomorpholine Prepared by stirring (5 hours) homomorpholine-hydrochloride with bromoacetaldehyde-dimethylacetal in the presence of potassium carbonate in N-methylpyrrolidinone at 80° C. Rf value: 0.2 (silica gel, ethyl acetate/methanol/conc. aqueous ammonia=90:10:1) Preparation of the Final Compounds: EXAMPLE 1 4-[(3-chloro-4-fluoro-phenyl)amino]-6-{[4-(homomorpholin-4-yl)-1-oxo-2-buten-1-yl]amino}-7-[(S)-(tetrahydrofuran-3-yl)oxy]-guinazoline A solution of 3.9 g of 4-[(3-chloro-4-fluoro-phenyl)amino]-6-[2-(diethoxy-phosphoryl)-acetylamino]-7-[(S)-(tetrahydrofuran-3-yl)oxy]-quinazoline in 20 ml of tetrahydrofuran is added to a solution of 300 mg of lithium chloride in 20 ml of water at ambient temperature. Then 2.35 g of potassium hydroxide flakes are added and the reaction mixture is cooled to −3° C. in an ice/acetone cooling bath. The solution of the homomorpholin-4-yl-acetaldehyde hydrochloride obtained in Example II is then added dropwise within 5 min at a temperature of 0° C. After the addition has ended the reaction mixture is stirred for another 10 min at 0° C. and for a further hour at ambient temperature. For working up 100 ml of ethyl acetate are added and the aqueous phase is separated off. The organic phase is washed with saturated sodium chloride solution, dried over magnesium sulphate and evaporated down. The crude product is purified by chromatography over a silica gel column using ethyl acetate/methanol/conc. methanolic ammonia as eluant. The product obtained is stirred with a little diisopropyl ether, suction filtered and dried. Yield: 2.40 g of (63 % of theory) Rf value: 0.09 (silica gel, ethyl acetate/methanol/conc. aqueous ammonia=90:10:1) Mass spectrum (ESI+): m/z=542, 544 [M+H]+ The following compounds may also be prepared analogously to the foregoing Examples and other methods known from the literature: Example No. Structure (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) EXAMPLE 2 Coated Tablets Containing 75 mg of Active Substance 1 tablet core contains: active substance 75.0 mg calcium phosphate 93.0 mg corn starch 35.5 mg polyvinylpyrrolidone 10.0 mg hydroxypropylmethylcellulose 15.0 mg magnesium stearate 1.5 mg 230.0 mg Preparation: The active substance is mixed with calcium phosphate, corn starch, polyvinylpyrrolidone, hydroxypropylmethylcellulose and half the specified amount of magnesium stearate. Blanks 13 mm in diameter are produced in a tablet-making machine and these are then rubbed through a screen with a mesh size of 1.5 mm using a suitable machine and mixed with the rest of the magnesium stearate. This granulate is compressed in a tablet-making machine to form tablets of the desired shape. Weight of core: 230 mg die: 9 mm, convex The tablet cores thus produced are coated with a film consisting essentially of hydroxypropylmethylcellulose. The finished film-coated tablets are polished with beeswax. Weight of coated tablet: 245 mg. EXAMPLE 3 Tablets Containing 100 mg of Active Substance Composition: 1 tablet contains: active substance 100.0 mg lactose 80.0 mg corn starch 34.0 mg polyvinylpyrrolidone 4.0 mg magnesium stearate 2.0 mg 220.0 mg Method of Preparation: The active substance, lactose and starch are mixed together and uniformly moistened with an aqueous solution of the polyvinylpyrrolidone. After the moist composition has been screened (2.0 mm mesh size) and dried in a rack-type drier at 50° C. it is screened again (1.5 mm mesh size) and the lubricant is added. The finished mixture is compressed to form tablets. Weight of tablet: 220 mg Diameter: 10 mm, biplanar, facetted on both sides and notched on one side. EXAMPLE 4 Tablets Containing 150 mg of Active Substance Composition: 1 tablet contains: active substance 150.0 mg powdered lactose 89.0 mg corn starch 40.0 mg colloidal silica 10.0 mg polyvinylpyrrolidone 10.0 mg magnesium stearate 1.0 mg 300.0 mg Preparation: The active substance mixed with lactose, corn starch and silica is moistened with a 20% aqueous polyvinylpyrrolidone solution and passed through a screen with a mesh size of 1.5 mm. The granules, dried at 45° C., are passed through the same screen again and mixed with the specified amount of magnesium stearate. Tablets are pressed from the mixture. Weight of tablet: 300 mg die: 10 mm, flat EXAMPLE 5 Hard Gelatine Capsules Containing 150 mg of Active Substance 1 capsule contains: active substance 150.0 mg corn starch (dried) approx. 180.0 mg lactose (powdered) approx. 87.0 mg magnesium stearate 3.0 mg approx. 420.0 mg Preparation: The active substance is mixed with the excipients, passed through a screen with a mesh size of 0.75 mm and homogeneously mixed using a suitable apparatus. The finished mixture is packed into size 1 hard gelatine capsules. Capsule filling: approx. 320 mg Capsule shell: size 1 hard gelatine capsule. EXAMPLE 6 Suppositories Containing 150 mg of Active Substance 1 suppository contains: active substance 150.0 mg polyethyleneglycol 1500 550.0 mg polyethyleneglycol 6000 460.0 mg polyoxyethylene sorbitan monostearate 840.0 mg 2,000.0 mg Preparation: After the suppository mass has been melted the active substance is homogeneously distributed therein and the melt is poured into chilled moulds. EXAMPLE 7 Suspension Containing 50 mg of Active Substance 100 ml of suspension contain: active substance 1.00 g carboxymethylcellulose-Na-salt 0.10 g methyl p-hydroxybenzoate 0.05 g propyl p-hydroxybenzoate 0.01 g glucose 10.00 g glycerol 5.00 g 70% sorbitol solution 20.00 g flavouring 0.30 g dist. water ad 100 ml Preparation: The distilled water is heated to 70° C. The methyl and propyl p-hydroxybenzoates together with the glycerol and sodium salt of carboxymethylcellulose are dissolved therein with stirring. The solution is cooled to ambient temperature and the active substance is added and homogeneously dispersed therein with stirring. After the sugar, the sorbitol solution and the flavouring have been added and dissolved, the suspension is evacuated with stirring to eliminate air. 5 ml of suspension contain 50 mg of active substance. EXAMPLE 8 Ampoules Containing 10 mg Active Substance Composition: active substance 10.0 mg 0.01 N hydrochloric acid q.s. double-distilled water ad 2.0 ml Preparation: The active substance is dissolved in the requisite amount of 0.01 N HCl, made isotonic with common salt, filtered sterile and transferred into 2 ml ampoules. EXAMPLE 9 Composition: active substance 50.0 mg 0.01 N hydrochloric acid q.s. double-distilled water ad 10.0 ml Preparation: The active substance is dissolved in the necessary amount of 0.01 N HCl, made isotonic with common salt, filtered sterile and transferred into 10 ml ampoules. EXAMPLE 10 Capsules for Powder Inhalation Containing 5 mg of Active Substance 1 capsule contains: active substance 5.0 mg lactose for inhalation 15.0 mg 20.0 mg Preparation: The active substance is mixed with lactose for inhalation. The mixture is packed into capsules in a capsule-making machine (weight of the empty capsule approx. 50 mg). weight of capsule: 70.0 mg size of capsule 3 EXAMPLE 11 Solution for Inhalation for Hand-Held Nebulisers Containing 2.5 mg Active Substance 1 spray contains: active substance 2.500 mg benzalkonium chloride 0.001 mg 1N hydrochloric acid q.s. ethanol/water (50/50) ad 15.000 mg Preparation: The active substance and benzalkonium chloride are dissolved in ethanol/water (50/50). The pH of the solution is adjusted with 1N hydrochloric acid. The resulting solution is filtered and transferred into suitable containers for use in hand-held nebulisers (cartridges). Contents of the container: 4.5 g | 20040213 | 20070529 | 20050519 | 64098.0 | 0 | GRAZIER, NYEEMAH A | BICYCLIC HETEROCYCLES, PHARMACEUTICAL COMPOSITIONS CONTAINING THESE COMPOUNDS, THEIR USE AND PROCESSES FOR PREPARING THEM | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,779,069 | ACCEPTED | Methods of use of inhibitors of phosphodiesterases and modulators of nitric oxide, reactive oxygen species, and metalloproteinases in the treatment of peyronie's disease, arteriosclerosis and other fibrotic diseases | The present methods and compositions are of use for treatment of conditions involving fibrosis, such as Peyronie's disease plaque, penile corporal fibrosis, penile veno-occlusive dysfunction, Dupuytren's disease nodules, vaginal fibrosis, clitoral fibrosis, female sexual arousal disorder, abnormal wound healing, keloid formation, general fibrosis of the kidney, bladder, prostate, skin, liver, lung, heart, intestines or any other localized or generalized fibrotic condition, vascular fibrosis, arterial intima hyperplasia, atherosclerosis, arteriosclerosis, restenosis, cardiac hypertrophy, hypertension or any condition characterized by excessive fibroblast or smooth muscle cell proliferation or deposition of collagen and extracellular matrix in the blood vessels and/or heart. In certain embodiments, the compositions may comprise a PDE-4 inhibitor, a PDE-5 inhibitor, a compound that elevates cGMP and/or PKG, a stimulator of guanylyl cyclase and/or PKG, a combination of a compound that elevates cGMP, PKG or NO with an antioxidant that decreases ROS, or a compound that increases MMP activity. | 1. A method of preventing or treating a condition involving fibrosis comprising: a) administering a PDE inhibitor to an individual with a condition involving fibrosis; and b) preventing or treating the fibrosis. 2. The method of claim 1, wherein the PDE inhibitor inhibits PDE-4 and/or PDE-5. 3. The method of claim 2, wherein the administration of a PDE inhibitor comprises long term oral prevention or treatment with sildenafil, tadalafil, vardenafil, pentoxifyllin, rolipram or another inhibitor of PDE5A and/or PDE-4. 4. The method of claim 3, wherein the PDE inhibitor is administered at the same dosage per unit of body weight as the dosages administered to rodents. 5. The method of claim 3, wherein the PDE inhibitor is administered at a different dosage than the dosages administered to rodents. 6. The method of claim 1, wherein the condition is Peyronie's disease plaque, penile corporal fibrosis, penile veno-occlussive dysfunction, Dupuytren's disease nodules, vaginal fibrosis and/or clitoral fibrosis in female sexual arousal disorder, abnormal wound healing, keloid formation, general fibrosis of the kidney, bladder, prostate, skin, liver, lung, heart, intestines or any other localized or generalized fibrotic condition. 7. The method of claim 6, wherein the condition is Peyronie's disease plaque or Dupytren's disease nodules. 8. The method of claim 1, wherein the condition is vascular fibrosis, arterial intima hyperplasia, atherosclerosis, arteriosclerosis, restenosis, hypertension, cardiac hypertrophy or any other condition characterized by excessive fibroblast or smooth muscle cell proliferation or deposition of collagen and extracellular matrix in the blood vessels and/or heart. 9. The method of claim 8, wherein the condition is arteriosclerosis or hypertension. 10. The method of claim 2, wherein the PDE-4 or PDE-5 inhibitor is administered orally, by injection, by local administration to the penis or other target tissue. 11. The method of claim 2, wherein the PDE inhibitor comprises an antisense or siRNA vector for PDE-4 and/or PDE-5. 12. The method of claim 2, wherein the PDE-5 inhibitor is specific for PDE-5 variant 3. 13. A method of preventing or treating a condition involving fibrosis comprising: a) administering a compound that elevates cGMP or PKG to an individual with a condition involving fibrosis; and b) preventing or treating the fibrosis. 14. The method of claim 13, wherein the compound is a stimulator of guanylyl cyclase and/or PKG. 15. The method of claim 13, wherein the compound is a gene therapy vector comprising a PKG cDNA. 16. The method of claim 13, wherein the condition is Peyronie's disease plaque, penile corporal fibrosis, penile veno-occlussive dysfunction, Dupuytren's disease nodules, vaginal fibrosis, clitoral fibrosis, female sexual arousal disorder, abnormal wound healing, keloid formation, general fibrosis of the kidney, bladder, prostate, skin, liver, lung, heart, intestines or any other localized or generalized fibrotic condition, vascular fibrosis, arterial intima hyperplasia, atherosclerosis, arteriosclerosis, restenosis, cardiac hypertrophy, hypertension or any condition characterized by excessive fibroblast or smooth muscle cell proliferation or deposition of collagen and extracellular matrix in the blood vessels and/or heart. 17. A method of preventing or treating a condition involving fibrosis comprising: a) administering a compound that elevates NO(NO donor or generator) and/or decreases ROS to an individual with a condition involving fibrosis; and b) preventing or treating the fibrosis. 18. The method of claim 17, wherein the compound is an NO donor, an NO generator, a gene therapy vector comprising an NOS cDNA, or a PDE inhibitor. 19. The method of claim 18, further comprising administering an antioxidant in combination with the NO donor, NO generator, gene therapy vector comprising an NOS cDNA, or PDE inhibitor. 20. The method of claim 19, wherein the combination is effective to provide an antifibrotic effect without damaging non-fibrotic tissues by excessive peroxynitrite formation. 21. The method of claim 17, wherein the condition is Peyronie's disease plaque, penile corporal fibrosis, penile veno-occlussive dysfunction, Dupuytren's disease nodules, vaginal fibrosis, clitoral fibrosis, female sexual arousal disorder, abnormal wound healing, keloid formation, general fibrosis of the kidney, bladder, prostate, skin, liver, lung, heart, intestines or any other localized or generalized fibrotic condition, vascular fibrosis, arterial intima hyperplasia, atherosclerosis, arteriosclerosis, restenosis, cardiac hypertrophy, hypertension or any condition characterized by excessive fibroblast or smooth muscle cell proliferation or deposition of collagen and extracellular matrix in the blood vessels and/or heart. 22. A method of preventing or treating a condition involving fibrosis comprising: a) administering a compound that increases MMP activity to an individual with a condition involving fibrosis; and b) preventing or treating the fibrosis. 23. The method of claim 22, wherein the compound is an MMP activator, an antagonist of an MMP inhibitor, or a gene therapy vector comprising an MMP cDNA. 24. The method of claim 23, wherein the compound is a Beta thymosin or another peptide in the thymosin family. 25. The method of claim 1, wherein said administering comprises long term continuous treatment for weeks, months or years. 26. The method of claim 13, wherein said administering comprises long term continuous treatment for weeks, months or years. 27. The method of claim 17, wherein said administering comprises long term continuous treatment for weeks, months or years. 28. The method of claim 22, wherein said administering comprises long term continuous treatment for weeks, months or years. 29. A method comprising: administering an amount of a cyclic guanosine 3′,5′-monophosphate (CGMP) type 5 phosphodiesterase (PDE 5) inhibitor to effect a condition comprising fibrosis. | RELATED APPLICATIONS The present application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application Ser. No. 60/420,281, filed on Oct. 22, 2002, and claims the benefit of PCT Serial No. US03/33400, filed on Oct. 23, 2003. BACKGROUND OF THE INVENTION 1. Field The present methods and compositions relate to the field of Peyronie's disease, arteriosclerosis and other fibrotic conditions. More particularly, the method and compositions concern use of phosphodiesterase (PDE) inhibitors and modulators of nitric oxide, reactive oxygen species and metalloproteinases in the treatment of such conditions. In particular embodiments, the inhibitors inhibit type 4 and/or type 5 PDEs. 2. Description of Related Art Peyronie's disease (PD) is a fibromatosis (Hellstrom and Bivalacqua, 2000; Schwarzer et al., 2001; Jarow et al., 1997; Devine et al., 1997) of the tunica albuginea (TA), the specialized lining of the corpora cavernosa of the penis. Clinically, this usually leads to penile deformation (curved penis during erection), pain, and quite frequently erectile dysfunction. The initiating event is believed to be an external force to the erect penis that results in an injury to the TA of the corpora and the TA fails to heal normally (Jarow et al., 1997; Devine et al., 1997; Diegelmann, 1997; Sherratt and Dallon, 2002). In the detumesced state, the only indication of the disease is the palpation of a knot or scar within the TA, which in its most severe state presents as a calcified plaque. PD affects about 5% of men in the USA, and translating into about 3-4 million affected American males. Although the condition is not always associated with erectile dysfunction, patients usually present to the physician with either recognition of a palpable plaque on the penile shaft, pain with tumescence, impotence and/or difficulty with intromission that is due to curvature of the erect penis. Since the disorder was first described in 1743, no medical treatment has ever proven to be beneficial in combating the condition, thereby highlighting the need to develop novel approaches to combat this disorder. There may also be a genetic predisposition to developing PD, since it is associated with other contractures such as Dupuytren's disease (palmar fascia; 10-20% incidence or more in PD) (Connelly, 1999) and Ledeshore's disease (plantar fascia). The pathophysiology is characterized by localized disruption of the TA, increased microvascular permeability, persistent fibrin (deficient fibrinolysis) and collagen deposition, perivascular inflammation, disorganization and loss of elastic fibers (release of elastase by macrophages), disorganized collagen bundles, and an increase in TGF-β1 synthesis. This represents impairment in the repair process that leads to persistent fibrosis and a loss of elasticity of the TA. PD can rarely be alleviated by medical treatment with anti-inflammatory agents (corticosteroids, antihistamine), antioxidants (vitamin E, superoxide dismutase), collagen breakdown (collagenase), Ca channel blockers (verapamil), and other antifibrotic compounds (colchicine, Potaba: K aminobenzoate) (Hellstrom and Bivalacqua, 2000). In most cases, surgery is the only available option to correct the deformity and alleviate the pain so that normal sexual activity can be resumed. A need exists for non-surgical methods of treatment of Peyronie's disease and other medical conditions in which fibrosis is important. Fibrotic disease is not limited to the reproductive organs, but can be found in other tissues, such as cardiovascular tissues. Both erectile dysfunction (ED) and cardiovascular disease, particularly hypertension, are prevalent in the aging male (Kloner et al., 2002; Sullivan et al., 2001; Melman et al., 1999). One of the underlying causes of hypertension is arteriosclerosis, or arterial stiffness, due to an acquired fibrosis of the media of the arterial wall (Breithaupt-Grogler and Belz, 1999; Robert, 1999; Intengan and Schiffrin, 2000, 2001; Formieri et al., 1992). Arteriosclerosis is significantly associated with aging, and is recognized by an increase in collagen, and in some cases by a loss of smooth muscle cells (SMC) within the arterial media, which results in a decrease in the SMC/collagen ratio, often accompanied by endothelial dysfunction (Cai and Harrison, 2000). The pathogenesis of aging associated ED, both in the human and rat, is mostly related to the loss of SMC in the penile corpora cavernosa by apoptosis, with a corresponding increase in collagen fibers (Melman and Gingell, 1999; Cai and Harrison, 2000; Melman, 2001; Garban et al., 1995; Ferrini et al., 2001a). The clinical result of this aging process in the penis is defective cavernosal SMC relaxation leading to veno-occlusive dysfunction (Breithaupt-Grogler and Belz, 1999; Rogers et al., 2003), the most common cause of ED. In the arterial tree, excessive collagen deposition in the media, with or without loss of SMC, leads to defective vaso-relaxation and clinically may present as hypertension (Breithaupt-Grogler and Belz, 1999; Robert, 1999; Intengan and Schiffrin, 2000, 2001). Because the penis may be considered a specialized extension of the vascular tree, the common alterations observed in the SMC of both the penis and peripheral vascular system in the aging male, leading to ED and hypertension, respectively, suggest that both conditions may share a common etiology. A need exists for effective methods to treat and/or ameliorate the symptoms of a variety of fibrotic disease, such as PD, ED and arteriosclerosis. No effective method of treatment currently exists that is directed towards the molecular pathways underlying excessive collagen deposition. SUMMARY OF THE INVENTION Certain embodiments of the present invention fulfill an unresolved need in the art, by providing novel methods for therapeutic treatment of Peyronie's disease, erectile dysfunction, arteriosclerosis and other fibroses. In some embodiments, PD plaques and/or other fibrotic conditions can be pharmacologically arrested or reduced in size, by decreasing collagen synthesis and inducing myofibroblast apoptosis by increasing the NO/ROS ratio, the levels of cGMP, or the activation of its effector, PKG in the TA and/or stimulating collagen degradation by activating the MMPs and/or down-regulating the expression of the MMP inhibitors (TIMP), by increasing NO/cGMP levels and/or the thymosins in the TA. Particular embodiments of the invention may be directed towards increasing levels of cGMP and/or cAMP by selective inhibition of phosphodiesterase (PDE) isoforms. PDE isoforms of interest in the TA and in PD plaque tissues include PDE5A-3, PDE4A, PDE4B and PDE4D. As non-limiting examples, pentoxifylline and similar compounds act as a non-specific cAMP-PDE inhibitor and increase cAMP levels, while sildenafil and similar compounds selectively inhibit PDE5A and increase cGMP levels. Other embodiments may involve increasing NO levels, for example by administering L-arginine, a stimulator of NOS activity. As shown in the following examples, pentoxifylline, sildenafil and L-arginine all act to reduce the expression of collagen I and α-smooth muscle actin. Long-term administration of nitrergic agents, such as pentoxifylline, sildenafil and L-arginine may be of use to reduce PD plaque size and collagen/fibroblast ratio and may reverse or prevent the further development of the fibrosis observed in PD, ED, arteriosclerosis and other fibrotic conditions. BRIEF DESCRIPTION OF THE DRAWINGS The following drawings form part of the present specification and are included to further demonstrate certain embodiments of the claimed subject matter. The embodiments may be better understood by reference to one or more of these drawings in combination with the detailed description presented herein. FIG. 1. The effect of NO, TGF-β1, ROS and cGMP on fibroblast/myoblast differentiation and collagen deposition. FIG. 2. Inhibition of collagen deposition in the fibrotic plaque induced by TGF-β1 in the rat TA, by long-term oral treatment with L-arginine and PDE inhibitors, estimated by Masson staining. (A) Microphotographs (40×) of cross sections of half of the rat penis. Dark arrows indicate the outer extent of plaque development and of tunical thickening. Light arrowheads (lower right-hand corner of each panel) indicate the site of TGF-β1 injection. The control (−) was injected with TGF-β1 injection, no treatment was given. L-ARG received a TGF-β1 injection and L-arginine in water. SIL received a TGF-β1 injection and sildenafil in water. PXF received a TGF-β1 injection and pentoxifylline in water. (B) QIA evaluation (n=5 per group). Five sections/animal, three fields/section. FIG. 3. Stimulation of apoptosis, as estimated by TUNEL, in the fibrotic plaque induced by TGF-β1 injection into the rat TA, following oral treatment with L-arginine, sildenafil or pentoxiphylline. (A) Microphotographs (400×) of tissue sections. Arrows indicate apoptotic cells in the site of the plaque. The control (−) was injected with TGF-β1 injection, no treatment was given. L-ARG received a TGF-β1 injection and L-arginine in water. SIL received a TGF-β1 injection and sildenafil in water. PXF received a TGF-β1 injection and pentoxifylline in water. (B) QIA (n=5 per group) as in FIG. 2. FIG. 4. Expression of PDE-5 mRNA and protein in the human PD plaque and normal tunica albuginea, and their homologous tissues in the TGF-β1 rat model of PD. (A) Ethidium bromide-stained DNA bands obtained by RT/PCR from RNAs isolated from the respective tissues, and fractionated on agarose gels. (B) Luminol-stained protein bands obtained by western blot on polyacrylamide gels. PS: penile shaft; TA: tunica albuginea; PD: Peyronie's disease; CC: corpora cavernosa; CER: cerebellum; CRU: penile crura. (C) Microphotgraphs (200×) of sections from human and untreated rat tissues. D.ART: dorsal artery; ART: artery. Arrows show positive cells for PDE-5. FIG. 5. Inhibition of collagen I synthesis and myofibroblast differentiation by PDE inhibitors in fibroblast cultures from a human PD plaque. (A) QIA evaluation of collagen I and ASMA expression. Control (C) no addition; 50SIL: sildenafil (50 nM); 200SIL: sildenafil (200 nM); 200PXF:pentoxifylline (200 nM). (B) DAB-stained immunocytochemical detection of collagen III in PD cells incubated for 3 days in DME-serum free medium in the presence or absence of 5 ng/ml of TGF-β1 (200×). FIG. 6. Effects on collagen I synthesis and myofibroblast differentiation in fibroblast cultures from the human PD plaque by a cGMP analog (8-Br cGMP), estimated by immunocytochemistry. Cells were incubated for 3 days with the indicated concentration and collagen I and ASMA were immuno-cytochenmically detected. Values are means+/−SEM for three separate incubations. p<0.05 were as follows: panel A: a vs b,c; panel D: a vs c; all others were non-significant. FIG. 7. Expression of PDE-5 mRNA and protein in fibroblast cultures from human PD plaque and human and rat normal tunica albuginea. (A) Ethidium bromide staining of PDE-5A cDNA bands generated from cell RNA by RT-PCR and fractionated on agarose gels. (B) Luminol detection of PDE-5 protein bands obtained by western blot of cell extracts on PAGE. Arrows indicate PDE-5A variants. DUP: cells from Dupuytren's nodules. (C) Microphotographs (200×) of cell cultures stained with the indicated antibodies and counter-stained with Meyer haematoxylin FIG. 8. Gene transfer to the tunica albuginea of plasmid and adenoviral cDNA constructs facilitated by electroporation. Both the pCMV-βgal and the AdV-CMV-βgal constructs were injected into the tunica albuginea of the rat, followed by electroporation, and 10 days later rats were sacrificed and frozen fixed tissue sections were stained with X-gal, and counterstained with neutral red. TA: tunica albuginea. (200× magnification). FIG. 9. Induction of TGF-β1 expression in the Peyronie-like plaque induced by fibrin in the tunica albuginea of the rat. (A) Sections adjacent to the ones for plaques shown on FIG. 11 were immunostained with an antibody for TGF-β1. Arrows point to cells with intense staining. (220× magnification) (B) Image quantitation of positive cells in the average field of the fibrotic plaque (n=5). Values are means+/−SEM, and p values are as indicated. (200× magnification) FIG. 10. Confirmation by RT/PCR of alterations in the expression of certain genes in the human Peyronie's plaque as compared to the normal tunica albuginea. FIG. 11. PD-like plaque similar to the one induced in the rat can be elicited in the tunica albuginea of the mouse by TGF-β1 injection, detected by Masson staining. Low (4×, top); and high (100×, bottom) magnifications of mouse penis injected with saline and TGF-β1. Light arrows show the site of TGF-β1 injection. Boxes represent the area of high magnification. CC corpora cavernosa; UR: urethra; TA: tunica albuginea; Pl: plaque; NB: nerve bundle. FIG. 12. Expression of PDE-4 mRNA and protein in the human PD plaque and normal tunica albuginea, and their homologous tissues in the TGF-β1 rat model of PD, and in fibroblasts cultured from these tissues. (A) Ethidium bromide staining of DNA generated from PD and normal human TA tissue by RT/PCR with primers for PDE4A, PDE4B, and GAPDH (reference gene), separated by agarose gel electrophoresis. (B) PDE4 mRNA in rat penile shaft (PS), rat TA cells, or human TA or PD cells. TA: tunica albuginea; PD: Peyronie's disease; CC: corpora cavernosa smooth muscle; PS: penile shaft. (C) Luminol-stained protein bands on western blots of human tissue and cell extracts with the antibody against PDE4A. FIG. 13. Immunodetection of PDE-4 protein in the rat penis and cultures of rat and human tunica albuginea fibroblasts. Microphotographies of tissue sections (top panels) or cell cultures (middle and botom panels), as indicated, submitted to immunodetection with antibodies against PDE4A or PDE4D, and counterstained with Meyer haematoxylin. FIG. 14. Effect of pentoxifylline and sildenafil on cAMP and cGMP levels in fibroblast cultures from human PD plaque, estimated by enzyme immunoassays. Cells were incubated for 3 days in fibroblast growth medium (FGM)/10% fetal bovine serum, in the presence of SNAP (100 uM; medium changed daily) added 4 hs prior to the PDE inhibitors, and increasing concentrations of sildenafil or pentoxifylline. cGMP and cAMP levels were measured in cell homogenates. Results are the means of 2 separate experiments conducted in triplicate. (A) cGMP levels in the presence of sildenafil. (B) cGMP levels in the presence of pentoxifylline. (C) cAMP levels in the presence of pentoxifylline. FIG. 15. Intensification by iNOS blockade of aging-related fibrosis in the arterial media. Old male rats were given L-NIL for 3 weeks, or left untreated. Young untreated rats served as controls. Tissue sections were obtained from penis (to visualize the dorsal and bulbo-urethral penile arteries) and from the aorta and femoral artery, and stained with Masson (SMC: red; collagen: blue). (A) Micrographs from selected arteries and tissue sections, as indicated. Bar=50 μm. (B) Quantitative image analysis (QIA) expressed as ratios of areas occupied by SMC and collagen, as means+/−SEM. Aorta: A vs. B, C p<0.001; B vs. C p<0.01; Femoral: A vs B, C p<0.001; B vs. C p<0.01; Dorsal: A vs B, C P<0.001 B vs. P<0.05; Bulbourethral: A vs B, C p<0.001; B vs. C: NS. FIG. 16. Reduction by iNOS blockade of the aging-related stimulation of the nitrosative pathway in the media of the penile arteries. Sections were immunostained as indicated. Nitrotyrosine is a marker for peroxynitrite. (A) Micrographs from selected arteries and tissue sections, as indicated. Bar=50 μm. (B) QIA as on FIG. 15, expressed as intensity of immunostaining per area, as means+/−SEM. For iNOS: Dorsal: A vs. B p<0.05; A vs. C: N.S.; B vs C: p<0.05; Bulbo-urethral: A vs. B: p<0.05; A vs. C: N.S; B vs. C: p<0.05. For 3-nitrotyrosine: Dorsal: A vs. B: p<0.001; A vs. C: p<0.05; B vs. C: p<0.05; Bulbourethral: A vs. B p<0.01; A vs. C: N.S; B vs. C: p<0.01. FIG. 17. Intensification by iNOS blockade of aging-related oxidative stress in the arterial media. Tissue sections were immunostained for Cu2+, Zn2+ SOD and for Mn2+ SOD. (A) Micrographs from selected arteries and tissue sections only for Cu2+ Zn2+ SOD, as indicated. Bar=50 μm. (B) QIA as on FIG. 16, expressed as intensity of immunostaining per area, as means+/−SEM. Dorsal: A vs C p<0.05; A vs. NS; B vs. NS; Bulbourethral: A vs. C P<0.001; A vs. B P<0.05; B vs. P<0.01A vs B, C p<0.001; B vs. C: NS. Mn2+ SOD gave essentially similar results (not shown). FIG. 18. Differential expression of another marker of oxidative stress, heme oxygenase 1, in the adventitia of the arterial wall. Sections were immunostained with an antibody against heme oxygenase I and counterstained with hematoxylin. (A) Micrographs from the dorsal artery. Bar=50 μm. (B) QIA as on previous figures. Values expressed as means+/−SEM. *p<0.05: young vs old (t test). FIG. 19. Reduction by iNOS blockade of the aging-related stimulation of apoptosis in the media of the penile arteries. Sections were immunostained with the TUNEL procedure and counterstained with methyl green. (A) Micrographs from selected arteries and tissue sections, as indicated. Bar=50 μm (B) QIA as on previous figures, expressed as apoptotic index (percent number of apoptotic cells/total number of cells), as means+/−SEM. Dorsal: A vs. B, C p<0.001; B vs. C p<0.05; Bulbourethral: A vs. C p<0.001; A vs. p<0.05; B vs C p<0.01 FIG. 20. Intensification by iNOS blockade of the aging-related stimulation of PAI expression in the media of the penile arteries. Sections were immunostained with an antibody against PAI and counterstained with hematoxylin. (A) Micrographs from the dorsal artery. (B) QIA for both the dorsal penile and bulbourethral arteries, as on previous figures. Bar=50 Itm Values expressed as means+/−SEM. a vs. b,c: p<0.001. FIG. 21. Effect of 8 Br-cGMP on apoptosis in fibroblasts from human cultured PD plaque, estimated by TUNEL. (A) Microphotographs (200×) of apoptotic cells in incubations receiving no addition and 400 uM 8 Br-cGMP for 3 days. (B) Apoptotic index, as means+/−SEM for three separate incubations. a vs b,c p>0.05. Table 1. Differential profiles of selected gene expression in human Peyronie's plaques and Dupuytren's nodules against their respective control tissues determined with a DNA microarray assay. Table 2. Effect of aging on arterial wall thickness and lumen diameter in large and small arteries in the rat n=5; **: p<0.01. DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS Abbreviations and Definitions The following abbreviations are used herein. Other abbreviations not listed below have their plain and ordinary meaning. ASMA: α-smooth muscle actin; ED: erectile dysfunction; iNOS: inducible NOS (also NOS II); L-NAME: L-Nω-Nitro-L-arginine methyl esther; L-NIL: L-iminoethyl-L-lysine; MMP: matrix metalloproteinase; nNOS: neuronal NOS; NO: nitric oxide; NOS: nitric oxide synthase; PAI: plasminogen activator inhibitor; PD: Peyronie's disease; PDE: phosphodiesterase; PKG: protein kinase G; PPC: pluripotent cells; QIA: quantitative image analysis; ROS: reactive oxygen species; SMC: smooth muscle cell; SNAP: S-Nitroso-N-acetyl penicillamine; TA: tunica albuginea; TGF-β1: transforming growth factor-β1; TIMP: tissue inhibitor of MMP. As used herein, “a” or “an” may mean one or more than one of an item. This application concerns, at least in part, isolated proteins and nucleic acids for type 5 phosphodiesterase (PDE5, e.g., GenBank Accession Nos. NM033437, NM033431, NM033430, NM001083, NP246273, NP237223, NP236914, NP001074), as well as methods of therapeutic treatment of fibrotic diseases directed towards such proteins. In the present disclosure, reference to “PDE5” or “type 5 phosphodiesterase” without further qualification or limitation means any or all isoforms of PDE5. A “PDE5 isoform” is a variant of type 5 phosphodiesterase that differs in its primary structure (i.e., amino acid sequence) from other isoforms of PDE5. The term encompasses, but is not limited to, isoforms that are produced by truncation, amino acid substitution (mutation) or by alternative mRNA splicing, so long as some difference in amino acid sequence results. For the purposes of the present invention, other types of covalent modification would be considered to fall within the scope of a single isoform. For example, both phosphorylated and unphosphorylated forms of PDE5 would be considered to represent the same isoform. As used herein, an “inhibitor” of PDE5 means any compound or combination of compounds that acts to decrease the activity of PDE5, either directly or indirectly. An inhibitor can be a molecule, an atom, or a combination of molecules or atoms without limitation. The term “antagonist” of PDE5 is generally synonymous with an “inhibitor” of PDE5. Inhibitors may act directly on PDE5 by, for example, binding to and blocking the catalytic site or some other functional domain of PDE5 that is required for activity. An inhibitor may also act indirectly, for example, by facilitating or interfering with the binding of PDE5 to another protein or peptide. This application also concerns, at least in part, isolated proteins and nucleic acids for type 4 phosphodiesterase (PDE4, e.g., GenBank Accession Nos. NM006203, NM002600, NM006202, NP006194, NP002591, NP006193), as well as methods of therapeutic treatment of fibrotic diseases directed towards such proteins. In the present disclosure, reference to “PDE4” or “type 4 phosphodiesterase” without further qualification or limitation means any or all isoforms of PDE4. The terms “PDE4 isoform” and PDE4 “inhibitor” or “antagonist” are used consistently with the corresponding terms defined above for PDE5. Peyronie's Disease and Other Fibrotic Conditions Peyronie's Disease Peyronie's disease (PD) is a localized fibrosis of the tunica albuginea (TA) of the penis (Hellstrom and Bivalacqtia, 2000; Gonzalez-Cadavid et al., 2002; Gholami et al., 2002) affecting close to 5% of the male population (Schwarzer et al., 2001). The leading theory of the etiology of PD is that it results from an abnormal wound healing process of the TA subsequent to an injury, usually during coitus (Hellstrom and Bivalacqua, 2000; Gonzalez-Cadavid et al., 2002; Gholami et al., 2002; Jarow and Lowe, 1997; Devine et al., 1997). It is assumed that at the time of the injury, extravasation of blood borne proteins, mainly fibrin, into the TA occurs (Somers and Dawson, 1997; Van de Water, 1997; Herrick et al., 1999). Some of these foreign proteins may induce a severe but local inflammatory response in the TA resulting in the local release of pro-fibrotic factors, mainly transforming growth factor β1 (TGF-β1) and reactive oxygen species (ROS) (Hellstrom and Bivalacqua, 2000; Gonzalez-Cadavid et al., 2002; Gholami et al., 2002), which then trigger excessive deposition and disorganization of the collagen fibers. Within the injured TA of some individuals, the above process may result in: a) an increase in the differentiation of TA fibroblasts into myofibroblasts (Vernet et al., 2002); b) an increased deposition of collagen fibers by both the TA fibroblasts and myofibroblasts (Vernet et al., 2002; Ferrini et al., 2002); c) a decrease in apoptosis of the TA fibroblasts/myofibroblasts, and d) a decrease in the natural breakdown and reorganization of newly deposited collagen fibers that is normally performed by the matrix metalloproteinases (MMP) (Mignatti et al., 1996; Arthur, 2000). The MMPs are the collagenolytic enzymes that are involved in the natural turnover of collagen in the wound healing process. At its extreme, this process may become excessive, with newly deposited collagen and extracellular matrix in a tissue that fails to “heal and reorganize normally” (Mignatti et al., 1996) eventually becoming calcified (Gelbard, 1988; Muralidhar et al., 1996). Calcification may occur by osteoblasts that are transformed from pluripotent cells (PPC) among the fibroblasts and/or myofibroblasts within the TA by either autocrine and/or paracrine factor(s). The primary cell that is involved in collagen synthesis in the wound healing process is the fibroblast (Singer and Clark, 1999). For wound closure, some of the fibroblasts must differentiate into myofibroblasts (Vernet et al., 2002; Gonzalez-Cadavid et al., 2002; Gholami et al., 2002; Muralidhar et al., 1996; Singer and Clark, 1999, Powel et al., 1999), cells that are intimately involved in the terminal stages of the wound healing process. Once this process is completed, the myofibroblast is normally eliminated from the wound by apoptosis (Gabbiani, 1996). If myofibroblasts persist and do not undergo pre-programmed cell death, they may continue to synthesize additional collagen and extracellular matrix, leading to an increase in fibrosis. Within the TA, this increase in fibrosis may lead to the clinical recognition of a palpable Peyronie's plaque. In addition to being a stimulator of the differentiation of fibroblasts into myofibroblasts, TGF-β1 can be secreted by both fibroblasts and myofibroblasts (Powel et al., 1999; Tomasek et al., 1999; Walker et al., 2001). In other fibrotic conditions, like cardiac and renal fibrosis, TGF-β1 has been shown to not only increase the replication and differentiation of fibroblasts into myofibroblasts, but also to inhibit apoptosis of the myofibroblasts (Desmouliere, 1995; Chipev et al., 2000). This self-perpetuating cycle of cellular differentiation of fibroblasts into myofibroblasts and continued TGF-β1 secretion by these same two cell types, as a result of the exposure of these cells to TGF-β1 itself, may ultimately lead to excessive collagen synthesis. Coupled with a disorganization of collagen fibers and a decrease in their degradation by at least a partial inhibition of the MMPs (Iredale, 1997), this may explain the continued growth of the PD plaque. In response to the pro-fibrotic effects of TGF-β1 and ROS in the TA, the injured TA tissue attempts to counteract these pro-fibrotic processes by releasing the anti-fibrotic compound, nitric oxide (NO). NO in the TA is synthesized by the inducible nitric oxide synthase enzyme (iNOS) (Vernet et al., 2002; Gonzalez-Cadavid et al., 2002; Gholami et al., 2002; Ferrini et al., 2002). Therefore, in the development of PD, there may be a constant battle between pro-fibrotic and anti-fibrotic processes within the TA, as is evident from the results from DNA microarrays discussed in the Examples below, with the winner determining whether normal healing or a fibrotic condition ensues. As discussed in the Examples below, studies on the corresponding human tissues and cells combined with data from rat models have shown that the development of the PD plaque is associated with expression of inducible nitric oxide synthase (INOS) and stimulation of nitric oxide (NO) synthesis, in conjunction with an increase in oxidative stress and ROS levels (Vernet et al., 2002; Gholami et al., 2002; Hellstrom and Bivalacqua, 2000; Sikka et al., 2002). The specific inhibition of iNOS activity with L-iminoethyl-L-lysine (L-NIL) exacerbates fibrosis in the TGF-β1 rat model, consistent with a model wherein NO produced by iNOS plays an antifibrotic role in PD by at least three mechanisms: a) the quenching of the pro-fibrotic ROS by a reaction leading to the formation of peroxynitrite; b) the down-regulation of fibroblast replication and myofibroblast differentiation; and c) the consequent or independent reduction in the transcriptional expression of collagen I. An additional mechanism for NO to counteract fibrosis may involve stimulation of myofibroblast and/or fibroblast programmed cell death. The induction of apoptosis by NO is well documented, either in vitro by NO donors, such as S-Nitroso-N-acetyl penicillamine (SNAP) (Sikka et al., 2002; Nishio et al., 1996) or inducible nitric oxide synthase (iNOS) expression (Nishio et al., 1996; Tain et al., 2002), or in vivo by neuronal NOS (nNOS) activation (Ferrini et al., 2001b), iNOS induction (Ferrini et al., 2001b; Watanabe et al., 2002), or administration of the NOS substrate L-arginine (Wang et al., 1999; Holm et al., 2000). The proposed antifibrotic role of iNOS is in agreement with indirect results obtained in animal models of kidney and cardiac fibrosis, where general NOS inhibitors (not isoform-specific), such as L-Nω-Nitro-L-arginine methyl esther (L-NAME), cause or exacerbate fibrosis (Chatziantoniou et al., 1998; Boffa et al., 1999; Pechanova et al., 1999). L-arginine supplementation has been shown to be anti-fibrotic in vascular and renal disease (Peters et al., 2000), but has not been tested on the PD plaque. Thus, pharmacologic inhibition of the pro-fibrotic process and/or stimulation of the anti-fibrotic processes, may halt the progression and/or reverse the process of PD. More globally, such results may be extrapolated to more life-threatening fibrotic conditions such as renal, lung, liver, and cardiac fibrosis (Nagase and Brew, 2002; Martinez-Hernandez, 1994; Schuppan et al., 2000). The results disclosed herein provide novel avenues of therapy for not only PD but also for fibrosis in general. The interaction within the TA between the pro-fibrotic and anti-fibrotic factors acting on fibroblasts and myofibroblasts and their respective differentiation and apoptotic processes is outlined in FIG. 1. One of the major functions of NO produced by iNOS in the PD tissue is to react with the pro-fibrotic compound ROS to form peroxynitrite (Beckmann and Koppenol, 1996; Ferrini et al., 2001a; Vernet et al., 1998). Peroxynitrite is known to induce apoptosis in most cell types, and specifically of the collagen-producing cells such as the fibroblast and myofibroblast (Heigold et al., 2002; Duffield et al., 2000; Zhang and Phan, 1999). In addition, NO stimulates guanylyl cyclase to produce cGMP Gonzalez-Cadavid et al., 1999), which in turn stimulates PKG (protein kinase G) (Sinnaeve et al., 2002; Wollert et al., 2002). Like NO, both cgMP and PKG inhibit collagen synthesis and are anti-fibrotic (Sinnaeve et al., 2002; Wollert et al., 2002; Hofmann et al., 2000; Chen et al., 1999a, 1999b; Redondo et al., 1998). cGMP is normally degraded to inactive GMP by the phosphodiesterase (PDE) enzymes (Corbin and Francis, 1999; Uckert et al., 2001). Some of the inhibitors of these enzymes, like pentoxifylline, have also been shown to be anti-fibrotic in animal models and humans (Fischer et al., 2001; Desmouliere et al., 1999; Kremer et al., 1999). The accumulation of collagen, which is one of the histological hallmarks of tissue fibrosis, may in part be also due to the inactivation of the MMP enzymes that degrade the already laid-down collagen fibers during its natural turnover cycle (Mignatti et al., 1996; Arthur, 2000). MMPs can be inactivated by TIMPs, the tissue inhibitors of MMP, that have been shown to increase in fibrotic conditions (Iredale, 1997; McCrudden and Iredale, 2000; Arthur, 2000). Another anti-fibrotic effect of NO is that it stimulates MMP activity (Sasaki et al., 1998; Okamoto et al., 1997) and inhibits the expression of TIMP (Darby et al., 2002; Bugno et al., 1999). The results disclosed below provide a series of approaches (Magee et al., 2002b; Ferrini et al., 2002) focused on the role of the myofibroblast and the interaction between NO and ROS (the NO/ROS balance) in the pathogenesis of the PD plaque and in arteriosclerosis, particularly of penile arteries. These include the use of the established TGF-β1 rat model of PD (Ferrini et al., 2002; Vernet et al., 2002; Gonzalez-Cadavid et al., 2002; Gholami et al., 2002), the establishment and study of cell cultures from the human PD and normal TA tissues (Vernet et al., 2002; Gonzalez-Cadavid et al., 2002; Gholami et al., 2002), the application of quantitative image analysis (QIA) of tissue sections and cells subjected to histochemistry and immunohistochemistry (Ferrini et al., 2002; Vernet et al., 2002; Gonzalez-Cadavid et al., 2002; Gholami et al., 2002), the use of selective inhibitors of some of the biochemical pathways shown in FIG. 1 (Ferrini et al., 2002; Vernet et al., 2002; Gonzalez-Cadavid et al., 2002; Gholami et al., 2002), DNA microarrays for multiple gene expression (Magee et al., 2002b), the discovery that the same processes that occur in the PD fibrotic plaque are also involved in aging-related fibrosis of the arterial wall media leading to arteriosclerosis, which by affecting the penile arteries would cause ED, and other molecular biology assays that provide an integrated analysis of the molecular pathophysiology of this condition, with corresponding novel approaches to therapeutic intervention of fibrotic disease directed towards the underlying molecular pathways. The combination of 1) an agent that increases NO, cGMP or cAMP levels, with 2) a compound that reduces oxidative stress and ROS levels, such as an antioxidant, will preserve the antifibrotic effects of agents in the first category, without an undesirable excessive level of apoptosis that may lead to cytotoxicity in cells other than myofibroblasts (e.g., smooth muscle cells, neurons, endothelial cells, etc.) By reducing ROS with the antioxidant, the formation of deleterious levels of peroxynitrite (the product of ROS quenching by NO) would be reduced to the minimum required for effective antifibrotic effects on myofibroblasts and fibroblasts involved in excessive collagen and extracellular matrix synthesis, without damage to other tissues. In the case of the combination of an antioxidant with agents in the first category raising cGMP or cAMP levels, the reduction in ROS would allow more endogenous NO levels to be preserved. Therefore, the combination of agents may be more effective and safe than a single agent in either category alone. The skilled artisan will realize that the methods and compositions disclosed herein are of use not only for treatment of Peyronie's disease and ED due to loss of cavernosal smooth muscle in the trabecular spaces and penile arteries, but also for other conditions involving fibrosis, such as penile corporal fibrosis, Dupuytren's disease nodules, vaginal fibrosis, clitoral fibrosis, female sexual arousal disorder, abnormal wound healing, keloid formation, general fibrosis of the kidney, bladder, prostate, skin, liver, lung, heart, intestines or any other localized or generalized fibrotic condition, vascular fibrosis, arterial intima hyperplasia, atherosclerosis, arteriosclerosis, restenosis, cardiac hypertrophy or any other condition characterized by excessive fibroblast or smooth muscle cell proliferation or deposition of collagen and extracellular matrix in the blood vessels and/or heart. Both the vagina and clitoris are known to undergo fibrosis and hardening with aging, menopause and estrogen/testosterone deficiency. Together with poor lubrication, the vaginal/clitoral fibrosis contribute to the development of female sexual arousal disorder, affecting about 30 to 40% of women. (Traish et al., Arch. Sex Behav. 31:393-400, 2002; Park et al., Intl. J. Impot. Res. 13:116-124, 2001; Berman et al., J. Sex Marital Ther. 27:411-420, 2001; Berman et al., Urology 54:385-391, 1999; Berman et al., Fertil. Steril., 79:925-931, 2003.) The mechanisms of fibrosis are similar for a number of different organs and disease states. A distinction exists between long-term (weeks, months, years) continuous treatment with, for example, a PDE5 inhibitor such as sildenafil to maintain a constant level of these agents in order to arrest or regress a fibrotic condition, versus on demand (prior to the sexual act) single pill, short-term treatment with sildenafil or other PDE5 inhibitors to obtain smooth muscle vasodilation in the penis (male penile erection) or vagina/clitoris (female sexual arousal) upon sexual stimulation. Current studies with sildenafil are symptomatic to treat defects in vaginal/clitoral or penile vasodilation exclusively during a sexual act and are not addressed to the long-term cure of underlying tissue fibrosis. Additional details relevant to the treatment of fibrotic conditions are disclosed in the Examples section below as well as in the references of Vernet et al. (2002), Gonzalez-Cadavid et al. (2002) and Gholami et al. (2002), the entire texts of which are specifically incorporated herein by reference. Peripheral Vascular Disease, Erectile Disfunction and Hypertension One of the prevalent views of peripheral vascular disease is that it is caused by oxidative damage to the arterial wall by reactive oxygen species (ROS), that cause lipid peroxidation and other alterations (Cai and Harrison, 2000; Berry et al., 2001; Zalba et al., 2000). These compounds are mainly produced by xanthine oxidase, NADPH oxidase, as well as mitochondrial enzymes, and are counteracted by heme-oxygenase I and superoxide dismutase (SOD), which can reduce ROS by acting as endogenous antioxidants. In addition to causing endothelial damage, ROS are known stimulators of collagen deposition and SMC proliferation (Berry et al., 2001; Zalba et al., 2000) in the vascular wall. Xanthine oxidase and SOD are also present in the penile corpora cavernosa (Jones et al., 2002), and oxidative stress due to ROS has been postulated to be central to impaired cavernosal function in aging-related ED (Jones et al., 2002; Khan et al., 2001; Bivalacqua et al., 2003). Besides antioxidants, nitric oxide (NO) also quenches ROS in the vasculature, as shown by the increase in ROS levels and the development of cardiac and renal fibrosis and vascular stiffness when there is long-term systemic blockade of NOS activity with NOS inhibitors (Kitamoto et al., 2000; Gonzalez et al, 2000; Usui et al., 1999). The ROS-quenching and anti-fibrotic effects of NO are not limited to the SMC and can be demonstrated in other non-vascular conditions (Ferrini et al., 2002; Vernet et al., 2002). In this process, NO reduces ROS levels through the formation of peroxynitrite (Cai and Harrison, 2000; Jones et al., 2002; Ferrini et al., 2002; Vernet et al., 2002; Gewaltig and Kojda, 2002), thereby increasing the NO/ROS ratio. NO is also postulated to not only inhibit collagen synthesis directly, but to favor collagen degradation by stimulating metalloproteinases and down-regulating expression of their inhibitors, such as the plasminogen activator inhibitor (PAI) (Li et al., 2000; Kaikita et al., 2002). The predominance of nitrosative pathways over oxidative stress is proposed to be protective against fibrosis (Ferrini et al., 2002; Vernet et al., 2002), ED (Jones et al., 2002), atherosclerosis, and hypertension (Gewaltig and Kojda, 2002; Cheng et al., 2001). The NO/ROS balance also directly modulates the relaxation of the vascular and penile smooth muscle. The NO produced by the endothelial NOS in the vascular endothelium controls blood pressure by relaxing the arterial SMC (González-Cadavid et al., 1999). In the penile corpora cavernosa, NO as a mediator of penile erection is produced by the neuronal NOS, specifically the PnNOS variant (Berry et al., 2001), localized in the nerve terminals, and to a lesser extent by endothelial NOS in the lacunar and sinusoidal endothelium of the penis (González-Cadavid et al., 1999). In experimental animals, reduction in NOS levels in the vasculature and penile corpora is associated with hypertension (Gewaltig et al., 2002) and with ED, respectively (González-Cadavid et al., 1999; Garban et al., 1995; Berry et al., 2001). If oxidative stress becomes excessive, the reaction of ROS with NO to form peroxynitrite reduces NO concentration in the tissues, which may lead to hypertension and ED by impairing NO dependent SMC relaxation. It is still unknown to what extent these neuronal and endothelial NOS isoforms participate in producing NO as an antifibrotic mechanism. In contrast, more direct evidence has emerged recently on the role of the inducible isoform of NOS (iNOS) (Kibbe et al., 1999) in reducing ROS and modulating the SMC/collagen ratio in different tissues. iNOS is spontaneously induced in the corpora cavernosa (Ferrini et al., 2001a) and brain (Vernet et al., 1998; Ferrini et al., 2001b) during aging, and in certain fibrotic conditions (Ferrini et al., 2002; Vernet et al., 2002). In the vasculature, iNOS is also induced in the media in aging-related arterial stiffness (Goettsch et al., 2001; Chou et al., 1998; Cernadas et al., 1998), transplant arteriosclerosis (Lee et al., 1999), and atherosclerosis (Ihrig et al., 2001; Niu et al., 2001; Behr-Roussel et al., 2000), and it is assumed to inhibit collagen deposition and prevent medial hyperplasia via induction of SMC apoptosis and/or inhibition of SMC replication (Gewaltig and Kojda, 2002; Kibbe et al., 1999; Niu et al., 2001). The specific inhibition of iNOS activity by L-N-(iminoethyl)-lysine acetate (L-NIL) (Ferrini et al., 2002; Vernet et al., 2002; Behr-Roussel et al., 2000), or the blockade of iNOS expression in the iNOS knockout mouse (Ihrig et al., 2001; Niu et al., 2001; Hochberg et al., 2000), causes fibrosis in non-vascular tissues, a decrease in NO/peroxynitrite levels, an increase in ROS, and a reduction in the SMC/collagen ratio. Despite the fact that a certain predominance of the nitrosative over the oxidative pathways may preserve the normal integrity and function of blood vessels and corpora cavernosa, an excessive production of NO and peroxynitrite, may also induce apoptosis and cell loss (Ferrini et al., 2001a, 2002; Vernet et al., 2002; Kibbe et al., 1999). Depending on the context, this may be beneficial by preventing media hyperplasia in atherosclerosis and restenosis and ameliorate fibrosis in other systems (Ferrini et al., 2002; Vernet et al., 2002; Gewaltig et al., 2002; Behr-Roussel et al., 2000). But excessive peroxynitrite may also be noxious, if it leads to a loss of SMC and the subsequent impairment of tissue relaxation. We propose that during aging, iNOS induction in the vasculature is not restricted to the cavernosal SMC (Ferrini et al., 2001a) and large arteries (Goettsch et al., 2001; Chou et al., 1998; Cernadas et al., 1998), but is generalized to the wall of the entire peripheral vascular tree. This process would aim to counteract oxidative stress and metalloproteinase inhibition, and the subsequent decrease in the SMC/collagen ratio that causes loss of compliance and NO-induced vaso-relaxation. As disclosed in the following Examples, we have examined large and small (resistance) arteries in both young and aged rats for SMC/collagen ratio, iNOS, peroxynitrite, heme oxygenase I, SOD, PAI, and SMC apoptosis, and determined how these parameters were affected in aged rats when iNOS activity was specifically inhibited with L-NML. NO/cGMP Inhibition of Fibrogenic Pathways In molecular terms, the fibrotic process occurring during abnormal wound healing, e.g., in dermal wounds, is essentially an increased and disorganized collagen deposition impairing granulation tissue formation. This is accompanied by an increase in the local production and secretion of TGF-β1 (Klar and Morrisey, 1998; Badalamente et al., 1996; Wahl, 1997), a factor which: a) stimulates collagen synthesis (Tiggelman et al., 1997; Faouzi et al., 1999), b) inhibits collagenolysis (van der Zee et al., 1997) and fibrinolysis (Holmdahl et al., 2001), c) enhances the release of ROS (Casini et al., 1997; Muriel, 1998a), and d) transcriptionally represses iNOS (Hung et al., 1995). ROS are hydroxyl radicals and superoxide anions that are quenched by NO to primarily form peroxynitrite (Poli, 2000; Curtin et al., 2002; Cattell, 2002; Kim et al., 2001; Fan et al., 2000; Ito et al., 1992). The balance between NO and ROS levels is known to be considerably altered in other fibrotic conditions affecting liver (cirrhosis), lung (pulmonary fibrosis), kidney (renal fibrosis), heart (cardiac hypertrophy), and the vascular tree (arterial medial hyperplasia). This abnormal ratio between NO and ROS is believed to be due to both a decrease in local NO synthesis (presumably via iNOS) and an increase in ROS (Casini et al., 1997; Muriel, 1998a; Curtin et al., 2002; Cattell, 2002; Kim et al., 2001; Fan et al., 2000). ROS, produced by the macrophages and neutrophils, have been shown to induce lipid peroxidation in cell membranes and increase vascular permeability and leakage of fibrinogen and other clotting factors into tissue (Cattell, 2002; Kim et al., 2001). ROS generation during oxidative stress is accompanied by a considerable induction of heme-oxygenase-1 (HO-1) (Foresti et al., 1999; Nathan, 1997), the enzyme that protects against oxidative stress and acts as an anti-apoptotic and anti-inflammatory (Ryter and Choi, 2002) response. HO-1 can also be elicited by peroxynitrite. Among the several regulators of collagen deposition and wound healing, NO is particularly interesting as an inhibitor of fibrosis. In the case of PD, NO appears to be produced by the induction of iNOS in the TA (Ferrini et al., 2002; Vernet et al., 2002; Gonzalez-Cadavid et al., 2002; Gholami et al., 2002). This iNOS isoform is involved in producing persistent high levels of NO by transcriptional induction, essentially as a defensive mechanism during inflammation (Nathan, 1997a, 1997b). iNOS is physiologically expressed in the adult at very low basal levels, if at all. Only upon induction by cytokines, such as tumor necrosis factor α (TNFα), interleukin 1β (IL-1β), interferon-γ (INFγ), and related factors, does iNOS induction take place. It can under certain chronic conditions lead to a high, and some times excessive production of NO that acts as either a cytotoxic agent, or, in the specific case of collagen, inhibits fiber deposition. These conditions include inflammation, infections, cancer, degenerative diseases and aging, where the factors triggering this increased iNOS response are unknown (Kibbe et al., 1999; Wang et al., 2002a; Miller and Sandoval, 1999). Additionally, many NO metabolites, particularly peroxynitrite, trigger localized apoptosis and tissue toxicity (Nathan, 1997a). The specific role of NO as a regulator of wound healing is well established in vivo and in vitro (Curtin et al., 2002; Cattell, 2002; kim et al., 2001; Hogaboam et al., 1998; Rizvi and Myers, 1997; Cao et al., 1997; Chatziantoniou et al., 1998; Kolpakov et al., 1995). NO donors and the NOS substrate, L-arginine, have been shown to inhibit collagen fiber ((Curtin et al., 2002; Cattell, 2002; kim et al., 2001; Hogaboam et al., 1998; Rizvi and Myers, 1997; Cao et al., 1997; Chatziantoniou et al., 1998; Kolpakov et al., 1995) and fibrin deposition (Westenfeld et al., 2002; Dambisya and Lee, 1996; Catani et al., 1998; Dambisya et al., 1996), and TGF-β1 synthesis (Craven et al., 1997). The experimental decrease of NO synthesis by NOS inhibition, or the reduction of iNOS induction, leads to impaired wound healing (Schaffer et al., 1997a), and also to fibrosis, as documented in myocardial hypertrophy, coronary vascular remodeling following an infarct, cystic fibrosis, obstructive nephropathy, and pulmonary fibrosis (Takemoto et al., 1997; babal et al., 1997; Numaguchi et al., 1995; Ikeda et al., 1997; Moreno et al., 1996; Morrissey et al., 1996; Kelley and Drumm, 1998). Physiologically, the reduction of NO synthesis may occur by either transcriptional blockade of iNOS induction (Geller and Billiar, 1998; Forstermann et al., 1998), and in certain cases, down-regulation of eNOS (Forstermann et al., 1998), or by inhibition of NOS activity by advanced glycation-end products (AGE) (Jiaan et al., 1995) or a natural NOS competitive inhibitor such as asymmetric dimethyl arginine (ADMA) (Boger et al., 1998). In contrast to the anti-fibrotic effect of NO that would occur as a defense against fibrosis, in the early stages of normal wound healing NO actually stimulates collagen synthesis (Schaffer et al., 1997b; Yamasaki et al., 1998; Thornton et al., 1998; Sherratt and Dallon, 2002; Diegelmann, 1997). Therefore, the anti-fibrotic effects of NO may be the result of a continuous and high level of local NO synthesis, like the one produced upon iNOS induction (Ferrini et al., 2002; Vernet et al., 2002). This shows the importance of the local levels of NO for either facilitating normal collagen deposition (wound healing) or preventing its accumulation (fibrosis). Anti-fibrotic effects of NO may also be mediated by cGMP through guanylyl cyclase activation (Gonzalez-Cadavid et al., 1999). cGMP analogs inhibit collagen synthesis (Chen et al., 1999a, 1999b; Redondo et al., 1998), fibroblast replication (Chiche et al., 1998; Pandey et al., 2000), myofibroblast differentiation (Tao et al., 1999), and promote apoptosis (Loweth et al., 1997; Sirotkin et al., 2000; Taimor et al., 2000). PDE inhibitors, by elevating cGMP, also cause similar effects in vitro (Schade et al., 2002; Horio et al., 1999; Thompson et al., 2000), and in particular induce apoptosis in vivo (Chan et al., 2002; Takuma et al., 2001). Some of these PDE inhibitors, like pentoxifylline, are active in preventing experimental fibrosis in the lung, liver, and heart (Fischer et al., 2001; Desmouliere et al., 1999; Kremer et al., 1999), and are currently being used for the treatment of human liver fibrosis (Windmeier and Gressner, 1997) and Crohn's disease (Reimund et al., 1997). Role of Myofibroblast in Fibrosis One of the major pathological findings in tissue fibrosis is the presence of activated and proliferating myofibroblasts. These cells not only play an important role in the contraction phase of normal wound healing but they also are responsible for the development of tissue fibrosis or of a scar (Powel et al., 1999; Tomasek et al., 1999; Walker et al., 2001). The myofibroblast (FIG. 1) is the cell widely believed to generate the contracture in Dupuytren's disease, the condition present in 10-20% of PD cases (Connelly, 1999). It is believed that after fulfilling its role in wound contraction and in secreting collagen during healing, the myofibroblast disappears by programmed cell death (apoptosis) (Gabbiani, 1996). However, in Dupuytren's disease and other fibrotic conditions the myofibroblast persists, resulting in a persistent fibrosis and contracture (Kloen, 1999; Badalamente and Hurst, 1999). Morphologically, myofibroblasts are intermediate between the fibroblast and the smooth muscle cell. Phenotypically, they express large bundles of actin filaments (actin, myosin, and associated proteins: “stress fibers”), with a fibrillar space material named the “fibronexus”, composed of fibronectin. Myofibroblasts can be identified by the detection of both α smooth muscle actin (ASMA) (absent in fibroblasts), and vimentin (absent in smooth muscle cells). It is believed that myofibroblasts can originate from either fibroblasts, smooth muscle cells, or from an as yet uncharacterized stem cell (Powel et al., 1999; Tomasek et al., 1999; Walker et al., 2001). Upon the appropriate stimulation, the myofibroblast may revert back to a fibroblast or smooth muscle cell. Myofibroblasts express receptors for TGF-β1, PDGF, bFGF, endothelin, and prostaglandins. All these factors generate in culture, an “activated” myofibroblast that is able to proliferate. In liver fibrosis, this activated form of the myofibroblast can be transformed into the non-proliferating “stellate” form by either cAMP or PGE2 (Powel et al., 1999; Tomasek et al., 1999; Walker et al., 2001; Wu and Zern, 2000). The activated myofibroblast is then able to secrete cytokines, TGF-β1 and other growth factors, and inflammatory mediators. Within the latter category, the cell has been shown to release NO and ROS, and matrix proteins involved in wound repair and fibrosis, such as collagens I, III, IV, VI, and XVIII, laminins, proteoglycans, adhesion molecules and MMPs (Powel et al., 1999; Tomasek et al., 1999; Walker et al., 2001). The myofibroblast is involved in functions such as wound repair in skin and repair of the myocardium after myocardial infarction. This cell has been implicated in the pathophysiology of the Dupuytren contracture, keloids, myocardial fibrosis, ischemia reperfusion injury, coronary artery restenosis, glomerulonephritis, liver cirrhosis, pulmonary interstitial fibrosis, and many other fibrotic conditions (Powel et al., 1999; Tomasek et al., 1999; Walker et al., 2001). However, in PD, there are few reports on the role of the myofibroblasts, other than the description of the original culture of fibroblasts from the PD plaque (Somers et al., 1982) and a few more recent studies (Anderson et al., 2000a, 2000b; Mulhall et al., 2001a, 2001b) and our own work (Vemet et al., 2002; Gonzalez-Cadavid et al., 2002; Gholami et al., 2002). In cell culture, PD fibroblasts demonstrate a faster replication rate as compared to those from the normal TA, a higher production of a pro-fibrotic agent (basic fibroblast growth factor), and a potential alteration of the p53 pathway that normally represses cell replication and favors apoptosis, which would indicate a sort of “immortalization” in culture (Anderson et al., 2000a, 2000b; Mulhall et al., 2001a, 2001b). Other groups have studied fibroblast cultures from the Peyronie's plaque but did not focus on their myofibroblast content (Duncan et al., 1991; E1-Sakka et al., 1997a). Animal Models of PD An animal model of PD has recently been developed (E1-Sakka et al., 1997b; El-Sakka et al., 1998), based on the administration of a synthetic heptapeptide of human TGF-β1 directly into the TA of the rat. After 45 days, the animal develops histological alterations and collagen deposition resembling those observed in the human PD plaque (El-Sakka et al., 1997a, 1997b, 1998). The administration of the full human TGF-β1 protein to the TA leads to a similar process in the rat model (Vernet et al., 2002; Gonzalez-Cadavid et al., 2002; Gholami et al., 2002; El-Sakka et al., 1999, 1998). Another potentially useful animal model for the study of the pathophysiology of the PD plaque is the collagen I promoter transgenic mouse (Fakhouri et al., 2001; Tharaux et al., 2000). This mouse carries the regulatory region of the collagen I-α2 gene linked to two reporter genes, luciferase and β-galactosidase, so that whenever collagen mRNA synthesis is stimulated luciferase and α-galactosidase will be expressed. Both proteins can be estimated by a chemiluminescence reaction in tissue homogenates, and β-galactosidase specifically by the development of a blue color in tissue sections. This collagen 1 promoter mouse model has recently been used (Dussaule et al., 2000) to demonstrate the link between NO, endothelin, and collagen synthesis in kidney fibrosis, which is characterized by collagen I accumulation. In essence, by giving the NOS inhibitor L-NAME to these transgenic mice for up to 14 weeks, it was possible to induce nephroangio- and glomerulo-fibrosis, accompanied by an increase in luciferase levels and an increased urinary excretion rate of endothelin. The blockade of endothelin receptors with the selective ET antagonist bosentan reduced collagen deposition in the L-NAME animals, and abolished collagen I promoter activation, as quantitated by luciferase activity. This animal model demonstrated that NO inhibition induces an early activation of the collagen I gene in the kidney arterioles and glomeruli, suggesting that NO inhibits collagen deposition and the endothelin-mediated fibrogenic effect, as confirmed by other studies (Boffa et al., 1999; Tharaux et al., 1999). Nucleic Acids In certain embodiments of the present invention, genes encoding one or more isoforms of PDE4, PDE5, PKG, NOS, MMP or another protein may be incorporated into expression vectors for therapeutic use in fibrosis. As discussed below, a gene encoding a given protein may contain a variety of different bases and yet still produce a corresponding polypeptide that is indistinguishable functionally, and in some cases structurally, from the known sequences of such genes. It is a matter of routine for the skilled artisan to obtain known genomic and/or cDNA sequences encoding various proteins from publicly available sources, such as GenBank. Any reference to a nucleic acid should be read as encompassing a host cell containing that nucleic acid and, in some cases, capable of expressing the product of that nucleic acid. Cells expressing nucleic acids of the present invention may prove useful in the context of screening for agents that induce, repress, inhibit, augment, interfere with, block, abrogate, stimulate, or enhance the catalytic activity and/or regulatory properties of PDE4 and/or PDE5. Nucleic acids according to the present invention may contain an entire gene, a cDNA, or a domain of a protein that expresses catalytic activity. The nucleic acid may be derived from genomic DNA, i.e., cloned directly from the genome of a particular organism. In preferred embodiments, however, the nucleic acid would comprise complementary DNA (cDNA). The DNA segments of the present invention include those encoding biologically functional equivalent proteins and peptides. Such sequences may arise as a consequence of codon redundancy and amino acid functional equivalency that are known to occur naturally within nucleic acid sequences and the proteins thus encoded. Alternatively, functionally equivalent proteins or peptides may be created via the application of recombinant DNA technology, in which changes in the protein structure may be engineered, based on considerations of the properties of the amino acids being exchanged. Changes designed by man may be introduced through the application of site-directed mutagenesis techniques or may be introduced randomly and screened later for the desired function, as described below. Expression Vectors Nucleic acids encoding proteins or peptides may be incorporated into expression vectors for production of the encoded proteins or peptides. Non-limiting examples of expression systems known in the art include bacteria such as E. coli, yeast such as Pichia pastoris, baculovirus, and mammalian expression systems such as in COS or CHO cells. A complete gene can be expressed or, alternatively, fragments of the gene encoding portions of polypeptide can be produced. The gene or gene fragment encoding a polypeptide may be inserted into an expression vector by standard subcloning techniques. An E. coli expression vector may be used which produces the recombinant polypeptide as a fusion protein, allowing rapid affinity purification of the protein. Examples of such fusion protein expression systems are the glutathione S-transferase system (Pharmacia, Piscataway, N.J.), the maltose binding protein system (NEB, Beverley, Mass.), the FLAG system (IBI, New Haven, Conn.), and the 6×His system (Qiagen, Chatsworth, Calif.). Some of these systems produce recombinant polypeptides bearing only a small number of additional amino acids, which are unlikely to affect the antigenic ability of the recombinant polypeptide. For example, both the FLAG system and the 6×His system add only short sequences, both of which are known to be poorly antigenic and which do not adversely affect folding of the polypeptide to its native conformation. Other fusion systems are designed to produce fusions wherein the fusion partner is easily excised from the desired polypeptide. In one embodiment, the fusion partner is linked to the recombinant polypeptide by a peptide sequence containing a specific recognition sequence for a protease. Examples of suitable sequences are those recognized by the Tobacco Etch Virus protease (Life Technologies, Gaithersburg, Md.) or Factor Xa (New England Biolabs, Beverley, Mass.). The expression system used may also be one driven by the baculovirus polyhedron promoter. The gene encoding the polypeptide may be manipulated by standard techniques in order to facilitate cloning into the baculovirus vector. One baculovirus vector is the pBlueBac vector (Invitrogen, Sorrento, Calif.). The vector carrying the gene for the polypeptide is transfected into Spodoptera frugiperda (Sf9) cells by standard protocols, and the cells are cultured and processed to produce the recombinant antigen. See U.S. Pat. No. 4,215,051 (incorporated by reference). Amino acid sequence variants of the polypeptide may also be prepared. These may, for instance, be minor sequence variants of the polypeptide which arise due to natural variation within the population or they may be homologues found in other species. They also may be sequences which do not occur naturally but which are sufficiently similar that they function similarly and/or elicit an immune response that cross-reacts with natural forms of the polypeptide. Sequence variants may be prepared by standard methods of site-directed mutagenesis such as those described herein. Substitutional variants typically contain an alternative amino acid at one or more sites within the protein, and may be designed to modulate one or more properties of the polypeptide such as stability against proteolytic cleavage. Substitutions preferably are conservative, that is, one amino acid is replaced with one of similar size and charge. Conservative substitutions are well known in the art and include, for example, the changes of: arginine to lysine; asparagine to glutamine or histidine; aspartate to glutamate; cysteine to serine; glutamine to asparagine; glutamate to aspartate; histidine to asparagine or glutamine; isoleucine to leucine or valine; leucine to valine or isoleucine; lysine to arginine or glutamine; methionine to leucine or isoleucine; phenylalanine to tyrosine, leucine or methionine; serine to threonine; threonine to serine; tryptophan to tyrosine; tyrosine to tryptophan or phenylalanine; and valine to isoleucine or leucine. Insertional variants include fusion proteins such as those used to allow rapid purification of the polypeptide and also may include hybrid proteins containing sequences from other proteins and polypeptides which are homologues of the polypeptide. For example, an insertional variant may include portions of the amino acid sequence of the polypeptide from one species, together with portions of the homologous polypeptide from another species. Other insertional variants may include those in which additional amino acids are introduced within the coding sequence of the polypeptide. These typically are smaller insertions than the fusion proteins described above and are introduced, for example, to disrupt a protease cleavage site. The engineering of DNA segment(s) for expression in a prokaryotic or eukaryotic system may be performed by techniques generally known to those of skill in recombinant expression. It is believed that virtually any expression system may be employed in the expression of the claimed nucleic acid sequences. As used herein, the terms “engineered” and “recombinant” cells are intended to refer to a cell into which an exogenous DNA segment or gene, such as a cDNA or gene has been introduced through the hand of man. Therefore, engineered cells are distinguishable from naturally occurring cells that do not contain a recombinantly introduced exogenous DNA segment or gene. Recombinant cells include those having an introduced cDNA or genomic gene, and also include genes positioned adjacent to a heterologous promoter not naturally associated with the particular introduced gene. To express a recombinant encoded protein or peptide, whether mutant or wild-type, in accordance with the present invention one would prepare an expression vector that comprises one of the claimed isolated nucleic acids under the control of, or operatively linked to, one or more promoters. To bring a coding sequence “under the control of” a promoter, one positions the 5′ end of the transcription initiation site of the transcriptional reading frame generally between about 1 and about 50 nucleotides “downstream” (i.e., 3) of the chosen promoter. The “upstream” promoter stimulates transcription of the DNA and promotes expression of the encoded recombinant protein. This is the meaning of “recombinant expression” in this context. Many standard techniques are available to construct expression vectors containing the appropriate nucleic acids and transcriptional/translational control sequences in order to achieve protein or peptide expression in a variety of host-expression systems. Cell types available for expression include, but are not limited to, bacteria, such as E. coli and B. subtilis transformed with recombinant bacteriophage DNA, plasmid DNA or cosmid DNA expression vectors. Promoters that are most commonly used in recombinant DNA construction include the β-lactamase (penicillinase), lactose and tryptophan (trp) promoter systems. While these are the most commonly used, other microbial promoters have been discovered and utilized, and details concerning their nucleotide sequences have been published, enabling those of skill in the art to ligate them functionally with plasmid vectors. For expression in Saccharomyces, the plasmid YRp7, for example, is commonly used (Stinchcomb et al., Nature, 282: 39, 1979; Tschemper et al., Gene, 10:157, 1980). This plasmid contains the trpl gene which provides a selection marker for a mutant strain of yeast lacking the ability to grow in tryptophan, for example ATCC No. 44076 or PEP4-1. The presence of the trpl lesion as a characteristic of the yeast host cell genome then provides an effective environment for detecting transformation by growth in the absence of tryptophan. Suitable promoting sequences in yeast vectors include the promoters for 3-phosphoglycerate kinase (Hitzeman et al., J. Biol. Chem., 255:2073, 1980) or other glycolytic enzymes (Hess et al., J. Adv. Enzyme Reg., 7:149, 1968; Holland et al., Biochemistry, 17:4900, 1978), such as enolase, glyceraldehyde-3-phosphate dehydrogenase, hexokinase, pyruvate decarboxylase, phosphofructokinase, glucose-6-phosphate isomerase, 3-phosphoglycerate mutase, pyruvate kinase, triosephosphate isomerase, phosphoglucose isomerase, and glucokinase. In constructing suitable expression plasmids, the termination sequences associated with these genes are also ligated into the expression vector 3′ of the sequence desired to be expressed to provide polyadenylation of the mRNA and termination. Other suitable promoters, which have the additional advantage of transcription controlled by growth conditions, include the promoter region for alcohol dehydrogenase 2, isocytochrome C, acid phosphatase, degradative enzymes associated with nitrogen metabolism, and the aforementioned glyceraldehyde-3-phosphate dehydrogenase, and enzymes responsible for maltose and galactose utilization. In addition to micro-organisms, cultures of cells derived from multicellular organisms may also be used as hosts. In principle, any such cell culture is workable, whether from vertebrate or invertebrate culture. In addition to mammalian cells, these include insect cell systems infected with recombinant virus expression vectors (e.g., baculovirus); and plant cell systems infected with recombinant virus expression vectors (e.g., cauliflower mosaic virus, CaMV; tobacco mosaic virus, TMV) or transformed with recombinant plasmid expression vectors (e.g., Ti plasmid) containing one or more coding sequences. Examples of useful mammalian host cell lines are VERO and HeLa cells, Chinese hamster ovary (CHO) cell lines, W138, BHK, COS-7, 293, HepG2, 3T3, RIN and MDCK cell lines. In addition, a host cell strain may be chosen that modulates the expression of the inserted sequences, or modifies and processes the gene product in the specific fashion desired. Such modifications (e.g., glycosylation) and processing (e.g., cleavage) of protein products may be important for the function of the encoded protein. In preferred embodiments of the invention, the host cells are human cells inside a subject with a fibrotic condition. Different host cells have characteristic and specific mechanisms for the post-translational processing and modification of proteins. Appropriate cells lines or host systems may be chosen to ensure the correct modification and processing of the foreign protein expressed. Expression vectors for use in mammalian cells ordinarily include an origin of replication (as necessary), a promoter located in front of the gene to be expressed, along with any necessary ribosome binding sites, RNA splice sites, polyadenylation site, and transcriptional terminator sequences. The origin of replication may be provided either by construction of the vector to include an exogenous origin, such as may be derived from SV40 or other viral (e.g., Polyoma, Adeno, VSV, BPV) source, or may be provided by the host cell chromosomal replication mechanism. If the vector is integrated into the host cell chromosome, the latter is often sufficient. The promoters may be derived from the genome of mammalian cells (e.g., metallothionein promoter) or from mammalian viruses (e.g., the adenovirus late promoter; the vaccinia virus 7.5K promoter). Further, it is also possible, and may be desirable, to utilize promoter or control sequences normally associated with the desired gene sequence, provided such control sequences are compatible with the host cell systems. A number of viral based expression systems may be utilized, for example, commonly used promoters are derived from polyoma, Adenovirus 2, and most frequently Simian Virus 40 (SV40). The early and late promoters of SV40 virus are particularly useful because both are obtained easily from the virus as a fragment that also contains the SV40 viral origin of replication. Smaller or larger SV40 fragments may also be used, provided there is included the approximately 250 bp sequence extending from the Hind site toward the Bgl I site located in the viral origin of replication. In cases where an adenovirus is used as an expression vector, the coding sequences may be ligated to an adenovirus transcription/translation control complex, e.g., the late promoter and tripartite leader sequence. This chimeric gene may then be inserted in the adenovirus genome by in vitro or in vivo recombination. Insertion in a non-essential region of the viral genome (e.g., region E1 or E3) will result in a recombinant virus that is viable and capable of expressing proteins in infected hosts. Specific initiation signals may also be required for efficient translation of the claimed isolated nucleic acid coding sequences. These signals include the ATG initiation codon and adjacent sequences. Exogenous translational control signals, including the ATG initiation codon, may additionally need to be provided. One of ordinary skill in the art would readily be capable of determining this and providing the necessary signals. It is well known that the initiation codon must be in-frame (or in-phase) with the reading frame of the desired coding sequence to ensure translation of the entire insert. These exogenous translational control signals and initiation codons may be of a variety of origins, both natural and synthetic. The efficiency of expression may be enhanced by the inclusion of appropriate transcription enhancer elements or transcription terminators (Bittner et al., Methods in Enzymol, 153: 516-544, 1987). In eukaryotic expression, one will also typically desire to incorporate into the transcriptional unit an appropriate polyadenylation site (e.g., 5′-AATAAA-3′) if one was not contained within the original cloned segment. Typically, the poly A addition site is placed about 30 to 2000 nucleotides “downstream” of the termination site of the protein at a position prior to transcription termination. Nucleic Acid Delivery Liposomal Formulations In certain broad embodiments of the invention, the oligo- or polynucleotides and/or expression vectors may be entrapped in a liposome. Liposomes are vesicular structures characterized by a phospholipid bilayer membrane and an inner aqueous medium. Multilamellar liposomes have multiple lipid layers separated by aqueous medium. They form spontaneously when phospholipids are suspended in an excess of aqueous solution. The lipid components undergo self-rearrangement before the formation of closed structures and entrap water and dissolved solutes between the lipid bilayers (Ghosh and Bachhawat, In: Liver Diseases, Targeted Diagnosis and Therapy Using Specific Receptors and Ligands, Wu et al. (Eds.), Marcel Dekker, New York, pp 87-104, 1991). Also contemplated are cationic lipid-nucleic acid complexes, such as lipofectamine-nucleic acid complexes. In certain embodiments of the invention, the liposome may be complexed with a hemagglutinating virus (HVJ). This has been shown to facilitate fusion with the cell membrane and promote cell entry of liposome-encapsulated DNA (Kaneda et al., Science, 243:375-378, 1989). In other embodiments, the liposome may be complexed or employed in conjunction with nuclear non-histone chromosomal proteins (HMG-1). In that such expression vectors have been employed in transfer and expression of a polynucleotide in vitro and in vivo, they may be applicable for the present invention. Liposomes within the scope of the present invention can be prepared in accordance with known laboratory techniques. In one embodiment, liposomes are prepared by mixing liposomal lipids, in a solvent in a container, e.g., a glass, pear-shaped flask. The container should have a volume ten-times greater than the volume of the expected suspension of liposomes. Using a rotary evaporator, the solvent is removed at approximately 40□C under negative pressure. The solvent normally is removed within about 5 min to 2 hours, depending on the desired volume of the liposomes. The composition can be dried further in a desiccator under vacuum. The dried lipids generally are discarded after about 1 week because of a tendency to deteriorate with time. The dried lipids or lyophilized liposomes prepared as described above may be reconstituted in a solution of nucleic acid and diluted to an appropriate concentration with an suitable solvent. The mixture is then vigorously shaken in a vortex mixer. Unencapsulated nucleic acid is removed by centrifugation at 29,000□g and the liposomal pellets washed. The washed liposomes are resuspended at an appropriate total phospholipid concentration, e.g., about 50-200 mM. The amount of nucleic acid encapsulated can be determined in accordance with standard methods. After determination of the amount of nucleic acid encapsulated in the liposome preparation, the liposomes may be diluted to appropriate concentration and stored at 4□C until use. Alternative Delivery Systems Adenoviruses: Human adenoviruses are double-stranded DNA tumor viruses with genome sizes of approximate 36 kB. As a model system for eukaryotic gene expression, adenoviruses have been widely studied and well characterized, which makes them an attractive system for development of adenovirus as a gene transfer system. This group of viruses is easy to grow and manipulate, and they exhibit a broad host range in vitro and in vivo. In lytically infected cells, adenoviruses are capable of shutting off host protein synthesis, directing cellular machineries to synthesize large quantities of viral proteins, and producing copious amounts of virus. The E1 region of the genome includes E1A and E1B, which encode proteins responsible for transcription regulation of the viral genome, as well as a few cellular genes. E2 expression, including E2A and E2B, allows synthesis of viral replicative functions, e.g. DNA-binding protein, DNA polymerase, and a terminal protein that primes replication. E3 gene products prevent cytolysis by cytotoxic T cells and tumor necrosis factor and appear to be important for viral propagation. Functions associated with the E4 proteins include DNA replication, late gene expression, and host cell shutoff. The late gene products include most of the virion capsid proteins, and these are expressed only after most of the processing of a single primary transcript from the major late promoter has occurred. The major late promoter (MLP) exhibits high efficiency during the late phase of the infection (Stratford-Perricaudet and Perricaudet, In: Human Gene Transfer, O. Cohen-Haguenauer et al., eds., John Libbey Eurotext, France, pp. 51-61, 1991). As only a small portion of the viral genome appears to be required in cis (Tooze, Molecular Biology of DNA Tumor Viruses, 2nd ed., Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y., 1991), adenovirus-derived vectors offer excellent potential for the substitution of large DNA fragments when used in connection with cell lines such as 293 cells. Ad5-transformed human embryonic kidney cell lines (Graham et al., J. Gen. Virol., 36:59-72, 1977) have been developed to provide the essential viral proteins in trans. Advantages of adenovirus vectors over retroviruses include the higher levels of gene expression. Adenovirus replication is independent of host gene replication, unlike retroviral sequences. Because adenovirus transforming genes in the E1 region can be readily deleted and still provide efficient expression vectors, oncogenic risk from adenovirus vectors is thought to be low (Grunhaus and Horwitz, Seminar in Virology, 3:237-252, 1992). In general, adenovirus gene transfer systems are based upon recombinant, engineered adenovirus which is rendered replication-incompetent by deletion of a portion of its genome, such as E1, and yet still retains its competency for infection. Sequences encoding relatively large foreign proteins can be expressed when additional deletions are made in the adenovirus genome. For example, adenoviruses deleted in both E1 and E3 regions are capable of carrying up to 10 kB of foreign DNA and can be grown to high titers in 293 cells (Stratford-Perricaudet and Perricaudet, 1991). Persistent expression of transgenes following adenoviral infection has also been reported. Other Viral Vectors as Expression Constructs. Other viral vectors may be employed as expression constructs in the present invention. Vectors derived from viruses such as vaccinia virus (Baichwal and Sugden, In: Gene Transfer, Kucherlapati R, ed., New York, Plenum Press, pp. 117-148, 1986) adeno-associated virus (AAV) (Baichwal and Sugden, 1986) and herpes viruses may be employed. They offer several attractive features for various mammalian cells (Horwich, et al., J. Virol., 64:642-650, 1990). With the recent recognition of defective hepatitis B viruses, new insight was gained into the structure-function relationship of different viral sequences. In vitro studies showed that the virus could retain the ability for helper-dependent packaging and reverse transcription despite the deletion of up to 80% of its genome (Horwich et al., 1990). This suggested that large portions of the genome could be replaced with foreign genetic material. The hepatotropism and persistence (integration) were particularly attractive properties for liver-directed gene transfer. Chang et al. recently introduced the chloramphenicol acetyltransferase (CAT) gene into duck hepatitis B virus genome in the place of the polymerase, surface, and pre-surface coding sequences. It was cotransfected with wild-type virus into an avian hepatoma cell line. Culture media containing high titers of the recombinant virus were used to infect primary duckling hepatocytes. Stable CAT gene expression was detected for at least 24 days after transfection (Chang et al., Hepatology, 14:124A, 1991). Non-viral Methods. Several non-viral methods for the transfer of expression vectors into cultured mammalian cells also are contemplated by the present invention. These include calcium phosphate precipitation (Graham and van der Eb, Virology, 52:456-467, 1973) DEAE-dextran (Gopal, Mol. Cell Biol., 5:1188-1190, 1985), lipofectamine-DNA complexes, and receptor-mediated transfection (Wu and Wu, Biochemistry, 27: 887-892, 1988; Wu and Wu, J. Biol. Chem., 262: 4429-4432, 1987). Some of these techniques may be successfully adapted for in vivo or ex vivo use. In one embodiment of the invention, the expression construct may simply consist of naked recombinant vector. Transfer of the construct may be performed by any of the methods mentioned above which physically or chemically permeabilize the cell membrane. For example, Dubensky et al. (Proc. Nat. Acad. Sci. USA, 81:7529-7533, 1984) injected polyomavirus DNA in the form of CaPO4 precipitates into liver and spleen of adult and newborn mice demonstrating active viral replication and acute infection. Anti-Sense The term “antisense” is intended to refer to polynucleotide molecules complementary to a portion of a targeted gene or mRNA species. “Complementary” polynucleotides are those that are capable of base-pairing according to the standard Watson-Crick complementarity rules. That is, the larger purines will base pair with the smaller pyrimidines to form combinations of guanine paired with cytosine (G:C) and adenine paired with either thymine (A:T) in the case of DNA, or adenine paired with uracil (A:U) in the case of RNA. Inclusion of less common bases such as inosine, 5-methylcytosine, 6-methyladenine, hypoxanthine and others in hybridizing sequences does not interfere with pairing. Antisense polynucleotides, when introduced into a target cell, specifically bind to their target polynucleotide and interfere with transcription, RNA processing, transport, translation and/or stability. Antisense RNA constructs, or DNA encoding such antisense RNA's, may be employed to inhibit gene transcription or translation or both within a host cell, either in vitro or in vivo, such as within a host animal, including a human subject. The intracellular concentration of monovalent cation is approximately 160 mM (10 mM Na+; 150 mM K+). The intracellular concentration of divalent cation is approximately 20 mM (18 mM Mg+; 2 mM Ca++). The intracellular protein concentration, which would serve to decrease the volume of hybridization and, therefore, increase the effective concentration of nucleic acid species, is 150 mg/ml. Constructs can be tested in vitro under conditions that mimic these in vivo conditions. Antisense constructs may be designed to bind to the promoter and other control regions, exons, introns or even exon-intron boundaries of a gene. It is contemplated that effective antisense constructs may include regions complementary to the mRNA start site. One can readily test such constructs simply by testing the constructs in vitro to determine whether levels of the target protein are affected. Similarly, detrimental non-specific inhibition of protein synthesis also can be measured by determining target cell viability in vitro. As used herein, the terms “complementary” or “antisense” mean polynucleotides that are substantially complementary to the target sequence over their entire length and have very few base mismatches. For example, sequences of fifteen bases in length may be termed complementary when they have a complementary nucleotide at thirteen or fourteen nucleotides out of fifteen. Sequences that are “completely complementary” will be sequences which are entirely complementary throughout their entire length and have no base mismatches. Other sequences with lower degrees of homology also are contemplated. For example, an antisense construct that has limited regions of high homology, but also contains a non-homologous region (e.g., a ribozyme) could be designed. These molecules, though having less than 50% homology, would bind to target sequences under appropriate conditions. Although the antisense sequences may be full length cDNA copies, or large fragments thereof, they also may be shorter fragments, or “oligonucleotides,” defined herein as polynucleotides of 50 or less bases. Although shorter oligomers (8-20) are easier to make and increase in vivo accessibility, numerous other factors are involved in determining the specificity of base-pairing. For example, both binding affinity and sequence specificity of an oligonucleotide to its complementary target increase with increasing length. It is contemplated that oligonucleotides of 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, 50 or 100 base pairs will be used. While all or part of the gene sequence may be employed in the context of antisense construction, statistically, any sequence of 14 bases long should occur only once in the human genome and, therefore, suffice to specify a unique target sequence. In certain embodiments, one may wish to employ antisense constructs which include other elements, for example, those which include C-5 propyne pyrimidines. Oligonucleotides which contain C-5 propyne analogues of uridine and cytidine have been shown to bind RNA with high affinity and to be potent antisense inhibitors of gene expression (Wagner et al., Science, 260:1510-1513, 1993). Alternatively, the antisense oligo- and polynucleotides according to the present invention may be provided as RNA via transcription from expression constructs that carry nucleic acids encoding the oligo- or polynucleotides. Throughout this application, the term “expression construct” is meant to include any type of genetic construct containing a nucleic acid encoding a product in which part or all of the nucleic acid sequence is capable of being transcribed. Typical expression vectors include bacterial plasmids or phage, such as any of the pUC or Bluescript™ plasmid series or viral vectors adapted for use in eukaryotic cells. In preferred embodiments, the nucleic acid encodes an antisense oligo- or polynucleotide under transcriptional control of a promoter. The term promoter will be used here to refer to a group of transcriptional control modules that are clustered around the initiation site for RNA polymerase II. Promoters are composed of discrete functional modules, each consisting of approximately 7-20 bp of DNA, and containing one or more recognition sites for transcriptional activator or repressor proteins. At least one module in each promoter functions to position the start site for RNA synthesis. The best known example of this is the TATA box, but in some promoters lacking a TATA box, such as the promoter for the mammalian terminal deoxynucleotidyl transferase gene and the promoter for the SV40 late genes, a discrete element overlying the start site itself helps to fix the place of initiation. Additional promoter elements regulate the frequency of transcriptional initiation. Typically, these are located in the region 30-110 bp upstream of the start site, although a number of promoters have recently been shown to contain functional elements downstream of the start site as well. A variety of specific eukaryotic promoter elements are known in the art and any such known element may be used in the practice of the claimed invention. Depending on the promoter, it appears that individual elements can function either co-operatively or independently to activate transcription. The particular promoter that is employed to control the expression of a nucleic acid encoding the inhibitory peptide is not believed to be important, so long as it is capable of expressing the peptide in the targeted cell. Enhancers are genetic elements that increase transcription from a promoter located at a distant position on the same molecule of DNA. Enhancers are organized much like promoters. That is, they are composed of many individual elements, each of which binds to one or more transcriptional proteins. Any promoter/enhancer combination known in the art (e.g., the Eukaryotic Promoter Data Base) also could be used to drive expression of the gene. Where a cDNA insert is employed, typically one will typically include a polyadenylation signal to effect proper polyadenylation of the gene transcript. The nature of the polyadenylation signal is not believed to be crucial to the successful practice of the invention, and any such sequence may be employed, such as human growth hormone and SV40 polyadenylation signals. Also contemplated as an element of the expression construct is a terminator. These elements can serve to enhance message levels and to minimize read through from the construct into other sequences. In certain embodiments of the invention, the delivery of a nucleic acid in a cell may be identified in vitro or in vivo by including a marker in the expression construct. The marker would result in an identifiable change to the transfected cell permitting identification of expression. Enzymes such as herpes simplex virus thymidine kinase (tk) (eukaryotic) or chloramphenicol acetyltransferase (CAT) (prokaryotic) may be employed. siRNA Small interfering RNAs (siRNAs) are short RNA molecules (typically from 21 to 23 nucleotides in length) that may be used to induce targeted gene silencing by RNA interference (Myers et al., Nature Biotechnology 21:324-328, 2003; Elbashir, Nature 411:494-498, 2001; Caplen et al., Proc. Natl. Acad. Sci. USA 98:974247, 2001). SiRNAs occur naturally in vivo when double-stranded RNA is cleaved by ribonuclease III to produce a short siRNA sequence. Synthetic siRNAs may also be introduced into cells to inhibit expression of one or more selected genes. SiRNAs may be generated by standard solid-phase oligonucleotide synthesis, by RNA-specific endonuclease cleavage of double-stranded RNA, or by expression of transfected DNA templates incorporating promoter sequences for RNA polymerase III. Introduction of siRNA into a mammalian cell results in the targeted destruction of messenger RNAs of the same sequence. Commercial products for siRNAs are available from a number of sources, such as Gene Therapy Systems, Inc. (San Diego, Calif.), Promega (Madison, Wis.) and Sirna Therapeutics (Boulder, Colo.). Methods for design of siRNA sequences are publicly available. For example, the siRNA Target Finder may be used online at the Ambion website. Target mRNA sequences are input into the program, which then scans for 21 nucleotide sequences that begin with an AA dinucleotide. The program selects for siRNAs with about a 30 to 50% GC content, avoiding sequences with 4-6 polyT stretches that would function as terminators for RNA Polymerase III transcription. After selection of two to four siRNA candidates, the generated sequences may be searched for homology (for example, using the BLAST search engine on the NCBI server) to other untargeted mRNA sequences. SiRNAs with homology to non-targeted sequences are eliminated from consideration. SiRNA expression cassettes may also be obtained from Ambion (Austin, Tex.). SiRNAs may be purchased and used according to the manufacturer's instructions to provide targeted inhibition of the expression of specific genes, such as PDE-4 and/or PDE-5. Ribozymes Another method for inhibiting the expression of specific genes within the scope of the present invention is via ribozymes. Ribozymes are RNA-protein complexes that cleave nucleic acids in a site-specific fashion. Ribozymes have specific catalytic domains that possess endonuclease activity (Kim and Cech, 1987; Gerlach et al., 1987; Forster and Symons, 1987). For example, a large number of ribozymes accelerate phosphoester transfer reactions with a high degree of specificity, often cleaving only one of several phosphoesters in an oligonucleotide substrate (Cech et al., 1981; Michel and Westhof, 1990; Reinhold-Hurek and Shub, 1992). This specificity has been attributed to the requirement that the substrate bind via specific base-pairing interactions to the internal guide sequence (“IGS”) of the ribozyme prior to chemical reaction. Ribozyme catalysis has primarily been observed as part of sequence-specific cleavage/ligation reactions involving nucleic acids (Joyce, 1989; Cech et al., 1981). For example, U.S. Pat. No. 5,354,855 reports that certain ribozymes can act as endonucleases with a sequence specificity greater than that of known ribonucleases and approaching that of the DNA restriction enzymes. Thus, sequence-specific ribozyme-mediated inhibition of gene expression may be particularly suited to therapeutic applications (Scanlon et al., 1991; Sarver et al., 1990; Sioud et al., 1992). It was reported that ribozymes elicited genetic changes in some cells lines to which they were applied. The altered genes included the oncogenes H-ras, c-fos and genes of HIV. Most of this work involved the modification of a target mRNA, based on a specific mutant codon that is cleaved by a specific ribozyme. Several different ribozyme motifs have been described with RNA cleavage activity (Symons, 1992). Examples that are expected to function equivalently include sequences from the Group I self splicing introns including Tobacco Ringspot Virus (Prody et al., 1986), Avocado Sunblotch Viroid (Palukaitis et al., 1979; Symons, 1981), and Lucerne Transient Streak Virus (Forster and Symons, 1987). Sequences from these and related viruses are referred to as hammerhead ribozyme based on a predicted folded secondary structure. Other suitable ribozymes include sequences from RNase P with RNA cleavage activity (Yuan et al., 1992, Yuan and Altman, 1994, U.S. Pat. Nos. 5,168,053 and 5,624,824), hairpin ribozyme structures (Berzal-Herranz et al., 1992; Chowrira et al., 1993) and Hepatitis Delta virus based ribozymes (U.S. Pat. No. 5,625,047). The general design and optimization of ribozyme directed RNA cleavage activity has been discussed in detail (Haseloff and Gerlach, 1988, Symons, 1992, Chowrira et al., 1994; Thompson et al., 1995). The other variable on ribozyme design is the selection of a cleavage site on a given target RNA. Ribozymes are targeted to a given sequence by virtue of annealing to a site by complimentary base pair interactions. Two stretches of homology are required for this targeting. These stretches of homologous sequences flank the catalytic ribozyme structure defined above. Each stretch of homologous sequence can vary in length from 7 to 15 nucleotides. The only requirement for defining the homologous sequences is that, on the target RNA, they are separated by a specific sequence that is the cleavage site. For hammerhead ribozymes, the cleavage site is a dinucleotide sequence on the target RNA—a uracil (U) followed by either an adenine, cytosine or uracil (A,C or U) (Perriman et al., 1992; Thompson et al., 1995). The frequency of this dinucleotide occurring in any given RNA is statistically 3 out of 16. Therefore, for a given target messenger RNA of 1000 bases, 187 dinucleotide cleavage sites are statistically possible. The large number of possible cleavage sites in genes of moderate size, coupled with the growing number of sequences with demonstrated catalytic RNA cleavage activity indicates that a large number of ribozymes that have the potential to downregulate gene expression are available. Additionally, due to the sequence variation among different genes, ribozymes could be designed to specifically cleave individual genes or gene products. Designing and testing ribozymes for efficient cleavage of a target RNA is a process well known to those skilled in the art. Examples of scientific methods for designing and testing ribozymes are described by Chowrira et al., (1994) and Lieber and Strauss (1995), each incorporated by reference. The identification of operative and preferred sequences for use in ribozymes targeted to specific genes is simply a matter of preparing and testing a given sequence, and is a routinely practiced “screening” method known to those of skill in the art. Formulations and Routes for Administration to Patients In certain embodiments, the inhibitors or activators of PDE5, PKG, NOS, MMP or another protein and/or stimulators or agonists of cGMP may be used for therapeutic treatment of medical conditions, such as Peyronie's disease. Where clinical applications are contemplated, it will be necessary to prepare pharmaceutical compositions in a form appropriate for the intended application. Generally, this will entail preparing compositions that are essentially free of pyrogens, as well as other impurities that could be harmful to humans or animals. Aqueous compositions of the present invention comprise an effective amount of inhibitor or activator, dissolved or dispersed in a pharmaceutically acceptable carrier or aqueous medium. Such compositions also are referred to as innocula. The phrase “pharmaceutically or pharmacologically acceptable” refers to molecular entities and compositions that do not produce adverse, allergic, or other untoward reactions when administered to an animal or a human. As used herein, “pharmaceutically acceptable carrier” includes any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents and the like. The use of such media and agents for pharmaceutically active substances is well known in the art. Except insofar as any conventional media or agent is incompatible with the inhibitors or activators of the present invention, its use in therapeutic compositions is contemplated. Supplementary active ingredients also can be incorporated into the compositions. The active compositions of the present invention may include classic pharmaceutical preparations. Administration of these compositions according to the present invention will be via any common route so long as the target tissue is available via that route. This includes oral, nasal, buccal, rectal, vaginal or topical. Alternatively, administration may be by orthotopic, intradermal, subcutaneous, intramuscular, intraperitoneal or intravenous injection. Such compositions normally would be administered as pharmaceutically acceptable compositions. The active compounds also may be administered parenterally or intraperitoneally. Solutions of the active compounds as free base or pharmacologically acceptable salts can be prepared in water suitably mixed with a surfactant, such as hydroxypropylcellulose. Dispersions also can be prepared in glycerol, liquid polyethylene glycols, and mixtures thereof and in oils. Under ordinary conditions of storage and use, these preparations contain a preservative to prevent the growth of microorganisms. The pharmaceutical forms suitable for injectable use include sterile aqueous solutions or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions. In all cases the form must be sterile and must be fluid to the extent that easy syringability exists. It must be stable under the conditions of manufacture and storage and must be preserved against the contaminating action of microorganisms, such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, and liquid polyethylene glycol, and the like), suitable mixtures thereof, and vegetable oils. The proper fluidity can be maintained, for example, by the use of a coating, such as lecithin, by the maintenance of the required particle size in the case of dispersion and by the use of surfactants. The prevention of the action of microorganisms can be brought about by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, thimerosal, and the like. In many cases, it will be preferable to include isotonic agents, for example, sugars or sodium chloride. Prolonged absorption of the injectable compositions can be brought about by the use in the compositions of agents delaying absorption, for example, aluminum monostearate and gelatin. Sterile injectable solutions are prepared by incorporating the active compounds in the required amount in the appropriate solvent with various other ingredients enumerated above, as required, followed by filtered sterilization. Generally, dispersions are prepared by incorporating the various sterilized active ingredients into a sterile vehicle which contains the basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum-drying and freeze-drying techniques which yield a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof. The compositions of the present invention may be formulated in a neutral or salt form. Pharmaceutically-acceptable salts include the acid addition salts which are formed by reaction of basic groups with inorganic acids such as, for example, hydrochloric or phosphoric acids, or such organic acids as acetic, oxalic, tartaric, mandelic, and the like. Salts formed with free acidic groups can also be derived from inorganic bases such as, for example, sodium, potassium, ammonium, calcium, or ferric hydroxides, and such organic bases as isopropylamine, trimethylamine, histidine, procaine and the like. Upon formulation, solutions will be administered in a manner compatible with the dosage formulation and in such amount as is therapeutically effective. The formulations are easily administered in a variety of dosage forms such as injectable solutions, drug release capsules and the like. For parenteral administration in an aqueous solution, for example, the solution should be suitably buffered if necessary and the liquid diluent first rendered isotonic with sufficient saline or glucose. These particular aqueous solutions are especially suitable for intravenous, intramuscular, subcutaneous and intraperitoneal administration. In this connection, sterile aqueous media which can be employed will be known to those of skill in the art in light of the present disclosure. For example, one dosage could be dissolved in 1 ml of isotonic NaCl solution and either added to 1000 ml of hypodermoclysis fluid or injected at the proposed site of infusion. Some variation in dosage will necessarily occur depending on the condition of the subject being treated. The person responsible for administration will, in any event, determine the appropriate dose for the individual subject. Moreover, for human administration, preparations should meet sterility, pyrogenicity, general safety and purity standards as required by FDA Office of Biologics standards. EXAMPLES The following examples are included to demonstrate preferred embodiments of the invention. It should be appreciated by those of skill in the art that the techniques disclosed in the examples which follow represent techniques discovered by the inventors to function well in the practice of the invention, and thus can be considered to constitute preferred modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention. The results disclosed below are generally addressed to the following areas. NO/cGMP The antifibrotic effects of agents that, either orally or via gene transfer, stimulate the NO/cGMP pathways and increase NO levels and cGMP levels or PKG activity or agents that inhibit oxidative stress by decreasing ROS levels. For example, by a) gene transfer of the sense cDNA for iNOS or nNOS in a single transfection; b) long-term administration of an oral NO donor (e.g. molsidomine), or the NOS substrate (L-arginine) that produces a continuously elevated level of NO. Alternatively, by increasing cGMP and/or stimulating PKG by a) identifying PDE isoforms present in the affected tissue and using oral PDE inhibitors such as sildenafil, zaprinast, and pentoxifylline; b) by gene transfer of PKG1 cDNA, or its mutated version, to increase the level of PKG activation. In other alternatives, by reducing the concentration of ROS by a) early (to arrest the development of the PD-like plaque, arteriosclerotic plaque or other fibrotic lesion) or late (to induce regression of an already formed plaque) administration of oral antioxidants such as vitamin E or S-adenosyl methionine (SAME); b) combination therapy with antioxidant (Vitamin E or SAME) combined with one or more NO donors (molsidomine or L-arginine) or cGMP/PKG therapy (sildenafil, zaprinast, pentoxifylline, or PKG1 cDNA), to induce regression of the plaque (late treatment). MMP Stimulation of MMP (collagenolysis) induced by thymosin peptides or other MMP activators. Correlating MMP inhibition in fibrosis with the levels of TIMP1, an inhibitor of MMP. Use of the MMP inducers thymosin β-4 and 10 are to stimulate MMP activity. Materials and Methods Human Tissues and Cell Cultures Human tissue: Human TA was obtained from non-PD patients (n=4), two undergoing partial penectomy due to penile cancer and two undergoing penile prosthesis surgery. Plaque tissue was isolated from PD patients (n=8) who underwent a surgical procedure to treat this condition (Vernet et al., 2002; Ferrini et al., 2002; Magee et al., 2002b; Davila et al., 2003b). Fragments of newly obtained tissue are stored for 24 h in “RNA-later” (Ambion, Inc., Austin, Tex.), for RNA analysis, in 4% formalin for histochemistry and immunohistochemistry, or in culture medium (DMEM/10% fetal calf serum) or fibroblast growth medium (FGM-2) (Clonetics, Walkersville, Md.) with 20% fetal bovine serum, for protein analysis or cell culture. Tissues were then frozen at −80° C. until further use, except for fixed portions that were stored at 4° C. in PBS until paraffin embedding or cryosectioning, and pieces used for cell cultures. Primary human cell cultures: Human fibroblast primary cultures were obtained from fragments of PD plaque or TA essentially according to Smith and Liu (2002), and their purity was established by immunohistochemistry, as detailed below. New primary cultures were obtained from fragments of PD plaque or TA that were washed in Hanks solution, minced in a fibroblast growth medium (FGM) (BioWhittaker Inc., Walkersville, Md.) and 20% fetal bovine serum (FBS), and plated onto a 25 cm2 culture flask per specimen (Vernet et al., 2002). Fragments were left undisturbed until attachment for about 1 week. Once the monolayer started to develop, the fragment was removed. Medium with 10% FBS was changed once a week and when cells achieved approximately 80% confluence (3-4 weeks) they were trypsinized and split onto 10 cm plates. Cells were allowed to grow again to 80% confluence, with medium changed twice a week. The cells collected from this passage were considered as passage 1. Successive passages were performed at 1/3 split ratio, and studies were carried out on cells from passages 3 onwards. Studies were performed with PD cells from the 4th to the 10th passages. Cells were incubated on: a) 75 cm2 flasks for RNA isolation; b) 6-well plates for protein isolation; and c) 8-well removable chambers for cytochemistry and immunocytochemistry. Treatments with different additions were initiated 24 hours after plating and continued for different periods. Cells incubated in 8-well chamber slides were allowed to grow to 50-60% confluence. At this point, cells received in duplicate sildenafil, pentoxifylline, or 8-Br cGMP at the concentrations indicated, and were allowed to propagate for 3 days without changing medium. In certain cases SNAP was added and replaced daily after changing the medium (Vernet et al., 2002). All studies were done in duplicate or triplicate. For the isolation of rat TA fibroblasts, the TA was carefully dissected from rat corpora cavernosa tissue, and cultures were developed and their purity tested as in the case of the human tissues. Rodent Models and Tissue Processing TGF-β1 rat model. Male Fisher 344 rats, 9-11 month old purchased from the NIH/NIA colony (Harlan Sprague-Dawley, Inc., San Diego, Calif.) and maintained under controlled temperature and lighting, were anesthetized and injected in the penile TA at the middle of the penis with either vehicle only (saline, group 1) or 0.5 μg recombinant human TGF-β1 (Biotech Diagnostic, Laguna Niguel, Calif., groups 2-5) as disclosed (Ferrini et al., 2002; Vernet et al., 2002). After the injection, groups 1 and 2 were given drinking water while the other groups received water with L-arginine (2.25 g/kg/day, group 3) (Moody et al., 1997), or sildenafil (10 mg/kg/day, group 4) or pentoxifylline (10 mg/kg/day, group 5). Forty-five days later, or as indicated, animals were sacrificed and perfused through the left ventricle with saline followed by 4% formalin ((Ferrini et al., 2002; Vernet et al., 2002). After the penises were excised, the penile skin was denuded by removing the glans and adhering non-crural tissue. The penile shaft was separated from the crura and 2-3 mm transverse slices were cut around the site of the saline or TGF-β1 injection. All tissues were post-fixed overnight in 4% formalin, washed in PBS and stored at 4° C. TGF-β1-iNOS knock-out mouse model. The iNOS knockout strain (B6;129PNOS2<TmlLeu>), where iNOS expression was genetically blocked, and the corresponding wild type control (B6;129 PF1/y) (Hochberg et al., 2000), were injected (2-3 months old) in the TA with TGF-β1 as in the rat and sacrificed 45 days later. TGF-β1-collagen I promoter mouse model. The transgenic line pGB 19.5/13.5 was obtained from George Bou-Gharios (London, England). These animals harbor the promoter of the α2 chain of the mouse collagen type I gene linked to the E. coli β-galactosidase, that is expressed in cells and tissues where collagen I is normally expressed (Fakhouri et al., 2001; Tharaux et al., 2000; Dussaule et al., 2000). Animals were injected into the TA as above with TGF-β1, and sacrificed. Arterial Tree Rodent Model. Young (3-month) and aged (22-24 month) male Brown Norway rats were obtained from the NIH/NIA colony (Harlan Sprague-Dawley, Inc., San Diego, Calif.), and maintained under controlled temperature and lighting. One half of the aged animals were treated for 3 weeks with L-NIL at 0.1 g/l in the drinking water, while the rest of the animals received plain drinking water. Animals were anesthetized, pretreated with heparin, and perfused through the left ventricle with saline followed by 4% formalin. The abdominal aorta, brachial and femoral neurovascular bundles as well as the penis, denuded of its skin, were removed and post-fixed overnight in 4% formalin, and washed and stored in PBS at 4 C until paraffin embedding. General Procedures Injection-electroporation. Injection into the TA was performed with the appropriate AdV or plasmid cDNA constructs at doses described below, and electroporation was applied at 100 volts, 8 pulses/sec, 40 ms (Magee et al., 2002a). Minipump implantation. Alza osmotic minipumps (Alza Corp, Palo Alto, Calif.), #2001D, delivering 8 ul/hr of a saline solution (100 ul) containing the selected compound during a period of 24 hs for “short-term” treatment, or 0.25 ul/hour, for 2 weeks (Alza#1002) for “long-term” treatment, were implanted in a subcutaneous tunnel over the inguinal canal, and attached to the abdominal muscles with a non-absorbable suture. A delivery catheter from the minipump was placed through the tissues to the penile crura and sutured to the perineal muscles, as previously described (Garban et al., 1997; Gelman et al., 1998). Detection of PDE mRNA Expression in Tissues and Cells Total RNA was isolated from the human TA and PD tissues, from their respective fibroblast cultures, and from rat TA and penile shaft tissues, and their respective fibroblast and smooth muscle cell cultures, by the Trizol procedure (Gibco BRL, Gaithesburg, Md.). RNA was then submitted (1 ug) to reverse transcription (Vernet et al., 2002; Magee et al., 2002b; Ferrini et al., 2001b) using Superscript II RNase H− reverse transcriptase (Gibco BRL) and random primers (0.25 ug), followed by PCR with the respective gene specific primers (Kuthe et al., 2001): a) for human PDE5A, on nt 1027-1049 (forward) and nt 1788-1764 (reverse) of the respective cDNA (Genbank #158526); encompassing a 762 bp band common to the three variants 1-3; b) for rat PDE5A, the primers on nt 1905-1924 (forward) and nt 2479-2460 (reverse) of the respective cDNA (Genbank #NM 133584), generating a 575 bp band; c, d) for human PDE4A and B, on nt 942-965 (forward) and 1824-1802 (reverse), and nt 1909-1931 (forward) and 2315-2292 (reverse), respectively, of the cDNAs (Genbank #NM 006202 and NM 002600, respectively); as the source of the expected 883 bp (A) and 406 bp (B) bands; e) for rat PDE4, the primers on nt 241-260 (forward) and nt 656-637 (reverse) of the respective cDNA (Genbank #M25350), generating a band of 416 bp. PCR products were separated by electrophoresis on 1% agarose gels and stained with ethidium bromide. For densitometry, normalization was performed against the GAPDH housekeeping gene fragment generated in the same PCR reaction. Detection of PDE5 and 4 Protein Expression in Tissue and Cell Extracts Tissue extracts were obtained by homogenizing in a 1:6 wt/vol ratio in a buffer containing 0.32 M sucrose, 20 mM HEPES (pH 7.2), 0.5 mM EDTA, 1 mM dithithreitol and protease inhibitors (3 μM leupeptin, 1 μM pepstatin A, 1 mM phenylmethyl sulfonyl fluoride). In the case of cell extracts 0.5 ml of this solution per 10 cm Petri dish was used. The particulate and cytosolic fractions were obtained by homogenization of the cells in a Polytron Homogenizer, (Brinkmann, Switzerland), and centrifugation at 12,000×g for 60 min. Equal amounts of protein (30 ug) were run on 7.5% polyacrylamide gels, and submitted to western blot immunodetection with polyclonal anti-mouse PDE5 (against cGMP binding region) IgG (1:1000) (Calbiochem, La Jolla, Calif.), and a secondary donkey anti-mouse IgG linked to horse radish-peroxidase (Amersham Pharmacia, Piscataway, N.J.), followed by a luminol reaction (Simko and Simko, 2000; Magee et al., 2002b; Ferrini et al., 2001b). Human PDE5 does not cross-react with other PDE5 isoforms. Negative controls were performed without primary antibody. For PDE4 immunodetection, the following affinity purified IgGs were used (FabGennix Inc., Shreveport, La.): a) anti-PDE4A selective antibody (detecting variants identified by 1, 5, 8, x, and unassigned); b) anti-PDE4B (detecting variants 1-4), and anti-PDE4D (detecting variants 1-5) (Salanova et al., 1999). The presence of PDEs in the PD fibroblasts in culture was confirmed by the ability of increasing concentrations of sildenafil and pentoxifylline to raise the basal cGMP and cAMP levels in triplicate wells, either in the absence or the presence of the NO donor, SNAP (S-nitroso-N-acetyl penicillamine) (Alexis Biochemicals, San Diego, Calif.) added daily at 100 μM, as measured by cGMP and cAMP EIA (enzyme immuno absorption) kits (Cayman Chemical, Ann Arbor, Mich.). Experiments were performed in duplicate. Values were expressed as pmoles cGMP or cAMP/mg protein. To normalize for differences between experiments, the changes in cGMP and cAMP levels exerted by sildenafil and pentoxifylline were expressed as % of their respective control values in the absence of the PDE inhibitors. Histochemical and Immunohistochemical Determinations In the case of cell cultures, at completion of incubations, slides were removed from the chambers and cells were fixed for immunodetection for 20 min in 4% buffered formalin at room temperature for α-smooth muscle actin (ASMA) (as a myofibroblast marker), vimentin (as a general fibroblast marker), and in certain cases for PDE5 and PDE4, or in ethanol at −20 C for collagen I and III (Vernet et al., 2002). The cells were quenched, blocked with normal goat serum and incubated with monoclonal primary antibodies for ASMA and vimentin (Sigma Immunohistology Kits, Sigma Chemical Co, St. Louis, Mo.), collagen I, and collagen III (1:40) (Chemicon International, Temecula, Calif.), overnight at 4° C. (Vernet et al., 2002; Ferrini et al., 2002). Processing was according with the manufacturer's instructions for ASMA, vimentin and collagen, consisting in the respective monoclonal antibodies and an anti-mouse biotinylated secondary antibody, followed by avidin-biotinylated HRP and the 3-amino-9-ethylcarbazol (AEC) chromogen. For PDE5A, the antibodies were as described above. Negative controls omitted the first antibodies or were replaced by IgG isotype at the same concentration of the first antibodies. Counterstaining was done with Mayer's hematoxylin. All the slides were mounted with Aqua Mount (Lerner, Pittsburgh, Pa.). For PDE4, the anti PDE4A and PDE4B affinity purified IgGs used for western blot was employed, and in addition the anti-PDE4A4 and anti-PDE4D (detecting variants 1-5) from the same source (FabGennix Inc.) were used. In the case of tissue sections, the determinations of the collagen/smooth muscle ratio were carried out with Masson trichrome (Ferrini et al., 2002; Davila et al., 2003b) on adjacent 5 μm paraffin-embedded cross-sections from the human normal tunical or plaque tissues, or from a 2 mm area around the site of injection in the rat saline- and TGF-β1-injected shaft tissues. Other distal sections were obtained along the rat penile shaft. SMC and collagen fibers within the corporal tissue and vascular tree were estimated by Masson trichromic staining (Sigma Diagnostic, St. Louis, Mo.) (Ferrini et al., 2002; Vernet et al., 2002; Davila et al, 2203b) in sections adjacent to those used for immunohistochemical staining, followed by image analysis to measure the ratio between SMC (red) and collagen fibers (blue). The results were expressed as red/blue ratios per area (see below). In the arterial tree, the intima/media thickness (IMT), and the diameter of the lumen were also measured. The determinations of iNOS, nitrotyrosine, heme-oxygenase I, PAI-I (Davila et al., 2003b), manganese superoxide dismutase (MnSOD), and CuZn SOD (Cu/Zn SOD) (Martin et al., 1994) were carried out on 5 μm paraffin-embedded adjacent tissue sections, that. were quenched for endogenous peroxidase activity after deparaffinization and rehydration. Sections were blocked with normal goat serum, and incubated with polyclonal IgG antibodies against mouse iNOS (1:500) (Transduction Laboratories, Lexington, KT), nitrotyrosine (1:100) (Upstate, Lake Placid, N.Y.), Mn SOD and Cu/Zn SOD (Oxygen, Portland, Oreg.) (1:800 and 1:500 respectively), heme oxygenase I (Stressgen, San Diego, Calif.), or PAI-1 (Abcam Ltd, Cambridge, UK). For negative controls the first antibodies were replaced by IgG isotype. The detection was based on a secondary anti-rabbit biotinylated antibody (1:200) for iNOS and nytrotyrosine (Calbiochem, La Jolla, Calif.), or anti-sheep biotinylated antibody (1:200) for Cu/Zn and Mn SOD, followed by the ABC complex (1:100) (Calbiochem) and 3,3′ diaminobenzidine (spelling) (DAB) (Sigma, St Louis Mo.). Sections were counterstained with hematoxylin. TUNEL Assay for Apoptosis The TUNEL assay (Ferrini et al., 2001a, 2001b) was performed in the adjacent matched tissue sections used for collagen, iNOS or nitrotyrosine staining, applying the Apoptag Oncor kit (Oncor, Gaithersburg, Md.). In brief, after deparaffinization and rehydration, sections were incubated with proteinase K (20 ug/ml) and endogenous peroxidase activity was quenched with 2% H2O2. Sections were incubated with digoxigenin-conjugated nucleotides and TdT, and subsequently treated with antidigoxigenin-peroxidase. To detect immunoreactive cells, sections were stained with 0.5% DAB/0.01% H2O2, and counterstained with 0.5% methyl green. As a negative control, buffer was substituted for the TdT enzyme. Testicular sections from old animals were used as positive control. For cell cultures, the cells were fixed in 4% formaldehyde for 30 min on ice, and post-fixed with ethanol-acetic acid 2/1 for 5 min at −20 C. Then the above procedure was applied, except that the proteinase K was omitted. Quantitative Image Analysis (QIA) The quantitation of the staining obtained by either histochemical or immunohisto/cytochemical techniques was performed by computerized densitometry using the ImagePro 4.01 program (Media Cybernetics, Silver Spring, Md.), coupled to an Olympus BHS microscope equipped with a Spot RT digital camera or VCC video camera (Wang et al., 2001; Ferrini et al., 2001a, 2001b; Davila et al., 2003b). The number of positive cells was counted in a computerized grid against the total number of cells determined by counterstaining, and results were expressed as a percentage of positive cells over total cells. In addition, the integrated optical density (IOD) was obtained by measuring the density per object and multiplying it by the respective area. The sum of all the individual values in the field was then divided by the number of positive cells, to obtain the mean IOD/positive cell, as a measure of average immunoreactivity/cell. In certain cases, results were expressed as the unweighted average optical density per area (O.D/AREA), to determine the relative concentration of immunoreactive antigen. For collagen/smooth muscle staining, the ratio between the width of the area stained positive for collagen (blue) divided by the total area of the lacunar spaces plus smooth muscle (white+red) was employed. The apoptotic index (rate of programmed cell death) was calculated as the percentage of apoptotic cells within the total number of cells in a given area (non-apoptotic nuclei plus apoptotic cells). In all cases, five non-overlapping fields were screened per tissue section or per well. Three sections per tissue specimen from groups of five animals, or two wells per experimental point in cell incubations, were then used to calculate the means+/−SEM. For iNOS, nitroyrosine, heme-oxygenase, PAI-1, MnSOD and Cu/Zn SOD determination, at least 6 sections per specimen were analyzed. Each slide assayed had its corresponding negative control. In certain cases, the number of immuno-positive cells was determined as a percentage of the total counterstained nuclei in a computerized grid. In the Masson staining, the ratio between SMC (red) and collagen fibers (blue) was obtained and expressed per area. The rate of programmed cell death (apoptotic index) was expressed as the percentage of apoptotic cells within the total number of cells in a given area (non-apoptotic nuclei plus apoptotic cells). Statistical Analysis Values were expressed as mean (M)+/−standard error of the mean (SEM). The normality distribution of the data was established using the Wilk-Shapiro test, and the outcome measures between two groups were compared by the t test. Multiple comparisons among the different groups were analyzed by a single factor analysis of variance (ANOVA), followed by post-hoc comparisons with the Student-Neuman Keuls test, according to the Graph Pad prism V. 30. Differences among groups were considered significant at P<0.05. Example 1 Spontaneous iNOS Induction In Vivo in the PD Plaque Leads to Increased NO Synthesis, Peroxynitrite Formation, and Fibroblast Apoptosis It has been reported that aging per se results in the spontaneous induction of iNOS and the formation of the NO metabolite, peroxynitrite, in both the rat hypothalamus (Ferrini et al., 2001b; Vernet et al., 1998) and corpora cavernosa (Ferrini et al., 2001a). This was accompanied by apoptosis of both the neurons and the cavernosal smooth muscle. In the TGF-β1 induced rat model of PD, a similar iNOS induction in the TA (Bivalacqua et al., 2000; Hellstrom, 2001) has been reported. Initially, it was assumed that this process of iNOS induction was deleterious to the TA. As proposed herein, it is believed that iNOS induction in the TA, and perhaps in fibrosis in general, is a beneficial, anti-fibrotic, cellular defense mechanism. The locally produced NO from elevated iNOS would inhibit collagen deposition, oppose pro-fibrotic agents, and induce apoptosis of myofibroblasts, which pathologically persist in the PD plaque. This model has been examined in the TA (Ferrini et al., 2002; Vernet et al., 2002; Gonzalez-Cadavid et al., 2002; Gholami et al., 2002) by quantitative image analysis (QIA) of immunohistochemical and histochemical stained tissue sections, and measurement of RNA and protein expression by quantitative RT/PCR, northern blots, western blots, DNA microarrays, and other procedures (n=5 to 9 per experimental group). All results discussed below are significant (p<0.05), unless stated otherwise. It was first observed that in the human PD plaque, iNOS induction as seen by immunohistochemistry occurs spontaneously in discrete cells (Ferrini et al., 2002). These cells were identified as fibroblasts and myofibroblasts based on vimentin as markers for both cell types and alpha smooth muscle actin (ASMA) for myofibroblasts (Vernet et al., 2002). iNOS expression as measured by immunohistochemistry was also detected in the rat PD-like plaque 45 days after TGF-β1 injection in the TA, in comparison to control tissue obtained from rats injected with saline (Ferrini et al., 2002; Vernet et al., 2002). In addition, in plaque tissue from both rat and human, iNOS induction was accompanied by increased peroxynitrite, a product formed by the reaction of NO with ROS (Ferrini et al., 2002). In contrast to its inductive effects on cell apoptosis, peroxynitrite does not induce collagen deposition or fibrosis, which means it is not pro-fibrotic per se (Okamoto et al., 1997), and therefore, differs considerably from one of the compounds from which it originates, ROS, that is highly pro-fibrotic (Casini et al., 1997; Muriel et al., 1998a; Hung et al., 1995; Poli, 2000; Curtin et al., 2002; Cattell, 2002; Kim et al., 2001). The fibrotic plaque was visualized in the rat model by Masson staining showing disorganization of collagen fibers and intensification of collagen deposition and thickening of the TA (Ferrini et al., 2002). In the case of the human plaque, similar changes were revealed with Masson staining. We further observed an increase in collagen I mRNA levels and protein-bound hydroxy-proline, which are additional direct measurements of tissue collagen content (Ferrini et al., 2002). These initial results demonstrated that iNOS was strongly expressed in PD tissue and may play an important role in the plaque. To examine the specific role of NO on PD plaque formation, overall NOS activity was increased in the TA by treating the animals with the oral NOS substrate, L-arginine. The long-term oral administration of the NOS substrate, L-arginine, in the drinking water (2.25%), leads to a stimulation of NOS activity and NO synthesis in the whole penis (Moody et al., 1997) and should also be increased in the TA. In addition, NO has been shown to be a down-regulator of collagen synthesis (Haig et al., 1994). If NO has a down-regulatory effect on collagen synthesis in the plaque, then overproduction of NO should inhibit this collagen synthesis and prevent development or halt progression of the plaque. It was observed that increasing NO by oral L-arginine treatment for 45 days led to a considerable decrease in the size of the TGF-β1-induced plaque (FIG. 2A, top panels). The plaque in the rat model consists of disorganized collagen fibers and thickening of the TA that seems to spread extensively from the site of the TGF-β1 injection. This observed decrease in plaque development by oral L-arginine treatment was also verified by quantitating the ratio of the areas in the TA occupied by collagen fibers to the areas occupied by the cells and lacunar spaces (FIG. 2B). Changes in the width of the tunica as measured by QIA also confirmed these results (not shown). These observations demonstrate that NO, from oral NO donors, seems to play an anti-fibrotic role in the TA of the TGF-β1 injected rat model of PD. Another major effect of high levels of NO in any tissue is its conversion, by its interaction with ROS, into peroxynitrite, which is a known inducer of apoptosis (Beckmann et al., 1996; Ferrini et al., 2001a; Vernet et al., 1998; Heigold et al., 2002; Duffield et al., 2000; Zhang et al., 1999). NO in the TA may also act to increase apoptosis of those cells within the PD plaque that are responsible for promoting collagen synthesis. In the PD animal model given oral L-arginine (2.25%), there appeared to be an increase in the number of apoptotic cells per field in the PD-like plaque as compared to the control animals (FIG. 3A, top panels). But when an apoptotic index (apoptotic cells/total number of cells) was used to quantify apoptosis, no significant difference was observed (FIG. 3B), because of the parallel increase in cell number. Example 2 Inhibition of iNOS Activity In Vivo Stimulates Both Collagen Synthesis and Collagen Fiber Deposition in the Rat PD-Like Plaque The studies with L-arginine detailed in Example 1 show modulation of the size of the PD plaque by NO. To determine whether the NO involved in this anti-fibrotic process emanated from iNOS, we studied in the TGF-β1 rat model the effects of specifically blocking iNOS activity by the long-term oral administration of L-NIL, a specific iNOS inhibitor (Ferrini et al., 2002, Vernet et al., 2002). In the TGF-β1 injected rat model, treatment with L-NIL, which lowers NO derived from iNOS, induced a remarkable expansion and thickening of the TA that was due to excessive collagen fiber deposition (Ferrini et al., 2002). We also observed a considerable increase in peroxynitrite as indicated by nitrotyrosine formation in the TA (Ferrini et al., 2002). These observations further support the role of NO from iNOS in reducing the growth of the plaque in the rat TA. The effect of L-NIL in increasing collagen in the TA of the TGF-β1 rat model may be due to an increase in collagen synthesis, a decrease in its normal breakdown, or both. To determine whether the larger PD plaque in the L-NIL treated rat is due, at least in part, to an increase in collagen I synthesis (the most prevalent collagen protein in the TA), and not simply to the inhibition of collagenolysis by the MMPs, we injected a cDNA plasmid construct of the collagen I promoter driving the expression of a reporter gene (Magee et al., 2002a) into the site of the original TGF-β1 or saline injection, 10 days prior to sacrifice and 35 days after the TGF-β1 injection. This plasmid is an indicator of collagen I transcriptional activity within the rat PD plaque. Expression of the reporter β-galactosidase, measured by luminometry in tissue extracts from areas at and around the plaque, was considerably intensified in comparison to the control TA (Vernet et al., 2002). This suggests that the reduction in NO by L-NIL inhibition of iNOS, directly or indirectly, activates pro-fibrotic factors such as ROS to further activate the collagen I promoter. Example 3 The Inhibition of PDE Activity In Vivo Reduces Collagen Deposition and Intensifies Fibroblast Apoptosis in the PD-Like Plaque in the Animal Model Numerous studies have documented that increasing the levels of cGMP by inhibition of PDE enzymes, either with non-specific PDE inhibitors, such as pentoxifylline (Corbin and Francis, 1999; Uckert et al., 2001; Fischer et al., 2001; Desmouliere et al., 1999; Kremer et al., 1999), or specific isoform inhibitors for PDE-5 such as exisulind (Chan et al., 2002; Takuma et al., 2001), can inhibit collagen synthesis and fibrosis and can induce apoptosis in vivo and in cultured cells (Chiche et al., 1998; Pandey et al., 2000; Tao et al., 1999; Loweth et al., 1997; Sirotkin et al., 2000; Taimor et al., 2000; Schade et al., 2002; Horio et al., 1999; Thompson et al., 2000). Thus, elevating cGMP levels may be able to inhibit tunical plaque formation. A study was performed to determine whether the antifibrotic effects of NO in human and rat PD may be at least partially mediated by the elevation of its downstream product, cGMP. Pentoxifylline (a non-specific, generalized PDE inhibitor), and sildenafil (specific PDE-5 inhibitor) were given orally to the rat in their drinking water (100 mg/l for each PDE inhibitor) for 45 days following TGF-β1 injection to initiate the plaque in the rat model. FIG. 2A, bottom panels shows that, as assessed by Masson staining in terms of collagen fiber/cell-lacunae area ratio, and width of the tunica (not shown), there was considerable reduction in plaque size induced by the PDE inhibitors. This was accompanied by an intensification of the apoptotic index, especially for pentoxifylline (FIG. 3A, bottom panels). The finding that pentoxifylline is more effective than sildenafil in inducing apoptosis may be due to a number of possible mechanisms. Since pentoxifylline inhibits multiple PDE isoforms, it may suggest that other PDEs besides PDE5 may play a role in elevating cGMP levels within the TA that will lead to apoptosis of cells within the plaque. Additionally, PDE inhibitors may act differentially on the three processes that ultimately would inhibit fibrosis development, namely myofibroblast apoptosis, collagen synthesis, and collagen degradation. Although we have not identified the cells undergoing apoptosis, it is likely that they are fibroblasts/myofibroblasts, because those are the predominant cellular component of the rat TA, and because of the direct demonstration of the effects of these treatments on cultures of human fibroblasts and myofibroblasts (see below). Example 4 Presence of PDE5 in the Human Penile Tunica Albuginea and PD Plaque, in the Rat Tunica Albuginea, and in Fibroblasts Cultured From These Tissues As an initial assessment of PDE isoforms expressed in the TA, RT-PCR was performed on splice products of PDE5A (Kim et al., 2000). The observed effects of sildenafil (specific PDE5 inhibitor) and to a partial extent pentoxifylline (has some PDE5 inhibitor activity) are probably mediated by the PDE5A isoform. RT/PCR with primers common to the 3 PDE5A variants (Uckert et al., 2001; Lin et al., 2000a, 2002a) have shown that this enzyme is expressed in both human TA and PD tissues, as well as control tissue, the corpora cavernosa (FIG. 4A). FIG. 4A shows the ethidium bromide staining of PCR DNA fragments from reactions carried out in duplicate and fractionated by agarose gel electrophoresis. The 575 bp PDE5A DNA band was generated as expected from the rat penile shaft (PS) and the 762 bp from the human corpora cavernosa (CC) RNAs, and was amplified to a similar level in total RNA from the human TA and PD. No RNA was extracted from the normal TA and the TGF-β1-induced PD-like plaque in the rat, due to the difficulty in dissecting large amounts of tissue to avoid contamination by cavernosal smooth muscle. PDE5A expression was confirmed at the protein level by western blot assays of tissue extracts, as shown by the luminol-stained protein bands (FIG. 4B), that can discriminate the three splicing variant proteins of PDE5A designated as 1, 2, and 3 with respective apparent sizes of 100, 92, and 83 kDa, respectively (Lin et al., 2000a, 2002a). The three variants were detected as expected in the rat cerebellum (CER), our control tissue, whereas in the rat penile crura (CRU) and shaft (PS), the predominant forms were the 1 and 3, respectively, with only traces of variant 2 in the crura, and a band smaller than the 3 variant in the penile shaft. This PDE5A-3 variant, accompanied by smaller amounts of the 2 variant, was also expressed in the human corpora cavernosa (CC), and in the TA and PD plaque. Some PDE5A-1 variant was also detected in the human CC. Immunohistochemistry in human PD and TA sections confirmed the expression of PDE5 in both tissues, at a higher level in PD. In the rat, it is extremely difficult to isolate pure TA and PD-like tissue totally free from corpora cavernosa cells. Therefore, the whole rat penile shaft, comprised of both TA and corpora cavernosa was assayed. Immunocytochemical detection with an antibody detecting all three variants of PDE5A revealed that it was expressed in discrete cells interspersed among collagen fibers in the normal human TA and the PD plaque (FIG. 4C, upper panels). PDE5A was also detected in the media of the of the dorsal artery and those within the corpora cavernosa, and in both the corporal smooth muscle and TA of the penis (FIG. 4C, lower panels). PDE5 mRNA was also identified by RT/PCR in the fibroblasts cultured from the human normal TA and PD plaque, and from the rat TA (FIG. 7A), and the respective protein was detected by western blot in the human cells as a single PDE5A-3 variant, which agrees with what was observed in vivo in the TA and PD plaque, (FIG. 7B). The rat TA fibroblasts also express the 3 variant, accompanied by equal amounts of the 1 variant, despite the latter larger variant was not detected in the rat penile shaft. Immunocytochemical detection (FIG. 4C, upper panels) confirmed the expression of PDE5A in the three types of cells, namely fibroblasts from the human normal TA and PD plaque, and from the rat normal TA. However, in the latter case, as opposed to the human cell cultures derived from tissues reasonably free from contamination by cavernosal smooth muscle, the rat fibroblasts were obtained from whole corpora cavernosa including the smooth muscle. By successive passages in fibroblast culture medium (Smith et al., 2002), rather pure fibroblast cultures were selected, as evidenced from vimentin staining, and some were myofibroblasts, as seen with ASMA staining (FIG. 7A, bottom panels). Example 5 Presence of PDE4 Variants in the Human Penile Tunica Albuginea and PD Plaque, in the Rat Tunica Albuginea, and in Fibroblasts Cultured From These Tissues PDE4 mRNA Studies Since the cAMP-dependent PDE inhibitor, pentoxifylline, has been used previously as an antifibrotic compound (Lee et al., 1997; Becker et al., 2001; Raetsch et al., 2002), we investigated by RT/PCR whether PDE4 is expressed in the TA and PD tissues and the respective cell cultures, utilizing primers for two (A and B) of the three variants. FIG. 12A shows that PDE4A and B mRNAs are expressed in the human normal TA and in the PD tissue. Both variants were also detected in human corpora cavernosa tissue containing mainly smooth muscle (not shown). Confirming these results, PDE4A and B mRNAs were also found in the fibroblasts cultured from human TA and PD (FIG. 12B). In the case of the rat, PDE4 mRNA (without variant discrimination) was detected in the TA cells, and to a lesser degree in the penile shaft tissue, thus suggesting that PDE4 in the rat TA fibroblast cultures does not arise from contamination with smooth muscle, which in any case had been reasonably excluded above by immunocytochemistry. PDE4 Western Blot. Confirmation of the expression of PDE4A at the protein level was obtained by western blot with an antibody for the different variants, in extracts from the human cultured cells used for the identification of PDE4A in TA and PD plaque. FIG. 12C shows an intense 76 kDa band that would correspond to a variant identified in testis (Salanova et al., 1999), as well as a minor 102 kDa band for the so-called PDE4Ax, also seen in the testis. The 76 kDa protein is very intense in the three human tissues: TA, PD plaque, and corpora cavernosa, but the 102 kDa band was virtually not detected. No PDE4B could be visualized when the western blot membranes were stripped and reacted with an antibody specific for this isoform (not shown). PDE4 Immunohistochemistry Immunodetection with the PDE4A antibody identified cells all along the internal side of the TA, as well as in the corpora cavernosa smooth muscle, expressing PDE4A (FIG. 13, top). An antibody specific for PDE4D also showed cells reactive for this isoform, evidencing that both PDE4 genes are expressed in the TA and corpora cavernosa (FIG. 13, top). A similar situation is seen in the rat TA fibroblasts in culture, with considerable expression of PDE4A in most cells, whereas only a fraction of the cells express PDE4D (FIG. 13, middle). In contrast, most of the human TA fibroblasts were intensively stained with antibodies against the A and D isoforms (FIG. 13, bottom). Despite the fact that the PDE4B mRNA was identified by RT/PCR (see FIG. 12), virtually no protein reactivity for this isoform was observed by imunodetection in tissue sections or cell cultures (not shown). A similar situation occurred with one of the variants of PDE4A (PDE4A4), utilizing a specific antibody, different from the general used above for PDE4A that according to the supplier does not detect variant 4. Example 6 Incubation of PD Fibroblast Cultures With PDE Inhibitors or a cGMP Analog Reduces Collagen I Synthesis and Myofibroblast Differentiation, and Increases Apoptosis Verification that the PDE5A and PDE4 proteins detected in the TA and PD cells and tissues are enzymatically active was obtained by measuring the levels of cGMP in cell extracts of the PD fibroblast cultures, with a basal mean value+/−SEM of 5.0+/−0.4 pmol/mg protein (n=5) in the absence of additions. Levels of cGMP increased 5.0-fold with 100 uM SNAP (an NO donor) for 3 days, with fresh daily replacement of medium with SNAP. A cGMP analog able to enter the cell, 8 Br-cGMP, at 10 uM, was also able to increase cGMP levels by 6.4-fold, and with 100 μM 8 Br-cGMP, the levels of cGMP were dramatically elevated by 38.7-fold. The basal levels of cAMP were 42.6+/−12.7 pmol/mg protein in the absence of SNAP and did not vary significantly when measured after 3 days with SNAP. The cGMP-dependent PDE5 inhibitor sildenafil did not significantly stimulate cGMP levels in the absence of SNAP (not shown). However, in the presence of the NO donor, the cGMP levels expressed as % of the basal control levels in the absence of sildenafil, were increased dose-dependently by sildenafil after the 3-day incubation, as expected (FIG. 14A). When cells were incubated with this NO donor, increasing concentrations of pentoxifylline, also as expected, did not increase significantly cGMP levels expressed as % of control levels (FIG. 14B), but were very effective in increasing cAMP levels (FIG. 14C), thus confirming its role as a cAMP-dependent PDE inhibitor with little or no effect on cGMP-dependent PDE. In order to determine whether the PDE inhibitors may reduce collagen synthesis, the PD cells were incubated with or without the drugs at lower concentrations: pentoxifylline at 200 nM, and sildenafil, at 50 and 200 nM. After 3 days, cells were fixed and the intracellular deposition of collagen I and III was determined by immunocytochemistry with specific antibodies against the two isoforms. The antibody against collagen I elicited an intense granular and perinuclear staining (not shown). In contrast, collagen III was detected in only in about 30% of the cells, and stained more diffusely and rather lightly, even when cells where treated with TGF-β1 (10 ng/ml), a known stimulator of collagen III synthesis (FIG. 5B). Quantitation by image analysis (FIG. 5A) in the cultured human PD fibroblasts indicated that in the absence of additions, most of the cells (100%) expressed collagen I, and that both pentoxifylline and sildenafil at 200 nM completely inhibited collagen synthesis in a small number of cells (5-15% of the total, FIG. 5A top), and significantly reduced (30-40% decrease) the average intensity of expression per cell (FIG. 5A, bottom). In contrast, the PDE inhibitors did not decrease, but even increased, the synthesis of collagen III (not shown). More drastically than in the case of collagen I, both of the PDE inhibitors (pentoxifylline and sildenafil) significantly reduced the number of ASMA positive cells (myofibroblasts) from 37% in the control to about 24%. The average ASMA expression per cell was significantly reduced by the PDE inhibitors by more than 90% in all cases. To show that in the case of sildenafil some of the effects are mediated by the elevation of cGMP, the PD fibroblasts were then incubated for 3 days with 8-Br-cGMP, and a significant (30%) reduction in the number of cells expressing collagen I was obtained at 10 μM 8 Br-cGMP (FIG. 6), although a higher concentration (400 μM) did not induce further decrease (FIG. 6). In contrast to the effects of the PDE inhibitors observed in the previous experiments, collagen I expression per cell was reduced only moderately and non-significantly by the cGMP analog. The differentiation of fibroblasts into myofibroblasts measured by the level of ASMA expression per cell was decreased significantly by 400 μM 8 Br-cGMP, as in the case of the PDE inhibitors, but there was no effect on the relative number of positive cells (FIG. 6). The increase of cGMP in the PD cells incubated with 8 Br-cGMP leads to a stimulation of apoptosis, as shown by an increase in apoptotic bodies detected with the TUNEL technique (FIG. 21A). However, because of variability between experiments, the considerable 2.3 fold-increase measured by image analysis did not achieve statistical significance (FIG. 21B). Example 7 Increase in NO Levels in Fibroblast Cultures From Human Normal TA and PD Leads to Peroxynitrite Formation, Fibroblast Apoptosis, and Reduction of Intracellular Collagen We have developed primary cell cultures from human normal TA and PD plaque, obtained from different patients, that were dissected to avoid contamination with corporal smooth muscle. These cultures contain fibroblasts and some myofibroblasts, as shown by a 100% immuno-reactivity with a vimentin antibody (Vernet et al., 2002) and represent the main cellular component of the original tissues. The main features of these cultures, demonstrated by QIA immunocytochemistry, are: 1) a substantial morphological difference between the TA and PD plaque cells (Vernet et al., 2002), that corresponds to the observations in vivo. PD cells change from small, more spindle shaped cells to much bigger, polygonal cells with bigger nuclei and expansions, and in certain cases typical “stellate” appearance whereas TA cells do not substantially change in morphology. 2) These fibroblasts, particularly those of PD origin, are able to differentiate into vimentin+/ASMA+ myofibroblasts comprising about 30% of the cells in culture (Vemet et al., 2002), and this percentage of myofibroblasts is also seen in vivo in the plaque (Vemet et al., 2002). 3) The cultures can be induced to express iNOS, synthesize collagen I, and undergo apoptosis both in vitro and in vivo (Vernet et al., 2002). 4) Their responses to different agents, specifically the inhibitory action of an NO donor, SNAP, on a) collagen I synthesis in all the cells, and b) myofibroblast differentiation (Vernet et al., 2002), and their response to PDE inhibitors in cell culture (FIG. 5) resemble the responses observed in vivo in the animal model of PD treated with NO donors or PDE inhibitors (FIG. 3). 5) Collagen III, is also synthesized but to a lower extent than collagen I and is not significantly affected by NO or PDE inhibitors (FIG. 5). The use of an NO donor SNAP or iNOS induction with a cytokine cocktail increased intracellular NO reduced fibroblast numbers in both normal human TA and PD cultures (Vernet et al., 2002). This process is associated with the production of peroxynitrite, as evidenced by nitrotyrosine formation (not shown) and resembles the increase in apoptosis seen in vivo after sildenafil and pentoxifylline treatments. Example 8 The Increase in cGMP Levels in Fibroblast Cultures Leads to Fibroblast Apoptosis and the Reduction in Intracellular Collagen I To verify that the effects of pentoxifylline and sildenafil described above were due to an elevation in cGMP levels, we incubated human PD cells with a stable cGMP analog able to traverse the cell membrane, 8-BrcGMP. This compound (with levels as low as 10 uM) inhibited collagen I production by the cells (FIG. 6), and increased apoptosis, as determined by TUNEL (Ferrini et al., 2001a; Vernet et al., 1998), from 7.5+/−0.4 (control) to 20.5+/−1.1 (100 uM 8-BrcGMP) cells per field. The intracellular cGMP levels increased from 0.02 to 1.83 nmoles/106 cells with 100 uM 8-BrcGMP in control vs. treated cells, respectively. The effects of the PDE inhibitors, as seen in in vivo experiments, are most likely mediated in part by PDE-5, as shown by the presence of PDE5A mRNA (FIG. 7A), and specifically, the PDE5A-3 protein variant as in the in vivo derived tissues (FIG. 7B), in both the human TA and human PD derived cells. The fibroblast cultures obtained from the rat TA express all three PDE-5 variants. All human and/or rat cell cultures of normal TA and PD tissues were PDE5 positive by immunocytochemistry (FIG. 7C, top panels). Cells derived from human TA tissue were clearly fibroblasts with some myofibroblast differentiation, as assayed with vimentin and ASMA markers (FIG. 7C, bottom panels). Example 9 ROS Levels are Increased in the Human and Rat PD-Like Plaque Tissues and are Reduced by NO ROS plays an important role in the development and maintenance of many fibrotic disorders including PD, by stimulating collagen synthesis (Poli, 2000; Curtin et al., 2002; Cattell, 2002; Kim et al., 2001; Fan et al., 2000; Higuchi et al., 1999). Therefore, the interplay and reactivity of ROS with NO may be an important therapeutic target. We have previously shown that heme-oxygenase I immunoreactivity, a marker for the strong pro-fibrotic factor ROS, is increased in the PD plaque in comparison to normal TA in the human and the TGF-β1 rat model of PD (Ferrini et al., 2002). Additionally, when iNOS activity was blocked with L-NIL in the TGF-β1 rat model, there was a considerable elevation of ROS levels (Ferrini et al., 2002). The same inverse correlation between NO and ROS was observed utilizing superoxide dismutase immunodetection, which measures the antioxidative response in both human and PD tissue and in human fibroblast cultures (not shown). This reduction in the NO/ROS ratio is associated with a considerable stimulation of collagen deposition and collagen synthesis (Ferrini et al., 2002). Example 10 Use of Gene Transfer and Reporter Gene Expression for Analyzing PD Several of the therapeutic approaches disclosed herein are based on gene transfer of cDNA constructs to the penile TA (e.g., iNOS, PKG). Therapeutic administration of recombinant cDNA may lead to an elevated expression of the corresponding anti-fibrotic protein. In the case of the penis, we have utilized plasmid and adenoviral constructs of iNOS and penile nNOS (PnNOS) (Magee et al., 2002a), including the use of plasmid and adenoviral constructs expressing β-galactosidase as a reporter gene, and electroporation to enhance viral and plasmid uptake during transfection (Magee et al., 2002a). Such constructs can penetrate and spread into the TA, as shown by X-gal staining (FIG. 8) suggesting that the direct injection to the TA with and without electroporation is feasible for targeting genes to the TA for arresting or reversing the growth and development of the PD plaque. Example 11 Confirmation of the Pro-Fibrotic Role of TGF-β1 Expression in Another Model of PD The TGF-β1 rat model for PD is a very valuable tool, and since its introduction in 1997 (E1-Sakka et al., 1997b, 1998, 1999), we have been able to study various aspects of the pathophysiology of PD, some of which are presented above. However, in a different experimental design based on the ubiquitous finding of fibrin in histological samples of human PD tissue (not shown), we have recently re-confirmed the importance of TGF-β1 as the main profibrotic factor in eliciting the PD-like plaque in the TA of the rat. We observed considerable expression of this factor in a tunical lesion induced by the injection of a preparation of human fibrin (fibrinogen/thrombin/aprotinin) in the rat TA (FIG. 9). This tunical lesion, caused by fibrin and mediated by TGF-β1, is fully developed at 3 weeks, as visualized by Masson staining, and is indistinguishable from the one caused by the injection of TGF-β1 alone. However, the TGF-β1 model requires 6 weeks to develop, whereas this fibrin induced model only requires 3 weeks to fully develop (not shown). The fibrin induced plaque is accompanied by detection of fibrin in the lesion (similar to what is seen in the human, but absent from the TGF-β1 injected rat model), disorganization of elastin fibers, expression of iNOS and heme-oxygenase I, and an increased level of apoptosis. Save for the presence of fibrin in the TA, all findings are similar to the ones observed in the TGF-β1 injected model (not shown). Example 12 The TA and the PD Plaque are Tissues in Constant Turnover, and Collagenase Inhibition May Play a Role in Collagen Accumulation As disclosed above, collagen synthesis is stimulated in the TGF-β1 animal model of PD, particularly when NO synthesis is partially inhibited by L-NIL. Data obtained by DNA microarray analysis (Clontech) has allowed us to define and compare changes in the profile of multiple gene expressions at the mRNA level in the PD plaque versus normal TA. Data (Table 1), obtained in 9 patients and 9 control subjects indicated that: a) PD, like its related disorder Dupuytren's contracture, is a condition that seems to be in a state of dynamic flux, with alterations in the expression of mRNAs for genes related to collagen turnover and tissue remodeling, extracellular matrix synthesis and degradation, and cell replication and apoptosis. This suggests that the fibrosis of PD is not a terminal event but a dynamic one, and that it is possible to pharmacologically affect its steady state and alter its direction by: a) inhibiting collagen synthesis and/or fibroblast differentiation and replication, since a subset of differentially expressed genes are related to these processes; and/or b) by stimulating collagen breakdown, since there is a considerable increase in the expression of different types of MMPs (e.g. MMP2 and MMP9). The increased expression of MMPs was confirmed in human PD by RT/PCR (FIG. 10). MMPs may play an important role in extracellular matrix remodeling in the PD plaque. The inhibition of MMP may occur by increased activity of the MMP inhibitors (TIMP). We have verified the increased expression of TIMP in PD tissue using the more sensitive RT/PCR procedure, which showed a 2-fold stimulation of TIMP1. The increased expression of TIMP1 should lead to an increased inhibition of MMP. Example 13 The Expression of a Family of Wound Healing-Related Peptides, the Thymosins, is Increased in Human PD In the DNA microarray study mentioned above, we found increased expression of peptides belonging to the thymosin-β family (Table 1). These proteins stimulate MMP activity, cross-link to fibrin and collagen, and promote wound healing (Huff et al., 2002; Malinda et al., 1999; Sosne et al., 2002). Their increased synthesis in the PD plaque may be another manifestation of a defense mechanism that is unable to control or arrest the progression of fibrosis. The administration of thymosin-β4 has been proposed for wound healing (Huff et al., 2002; Malinda et al., 1999; Sosne et al., 2002), and, as stated above, PD is likely the result of an injury that does not heal properly. It should be possible to further up-regulate this endogenous defense mechanism by pharmacologically increasing thymosin levels in the TGF-β1-induced lesions in the rat model of PD. Example 14 Investigating the Role of NO and ROS in PD Using the iNOS Knockout Mouse Model The blockade of iNOS activity in the rat by long-term oral L-NIL administration (Ferrini et al., 2002) is only partially effective in inhibiting iNOS. Therefore, the iNOS knockout mouse (Hochberg et al., 2000) is of use for studies where iNOS expression is completely absent. NO in this animal model can be synthesized only by the other NOS isoforms, namely eNOS and nNOS. These isoforms are in general constitutive and as such are difficult to induce. It therefore seems unlikely that they would play a significant anti-fibrotic role. The iNOS knockout mouse has previously been used to show that experimental urethral fibrosis is intensified as a consequence of the iNOS knockout (Tanaka et al., 2002). We have tested whether it is possible to develop a PD-like plaque by injection of TGF-β1 into the TA, injecting 0.2 ug of TGF-β1 into the TA of a wild type mouse. FIG. 11 shows plaque formation within the TA at 6 weeks as shown with Masson staining. Example 15 Therapeutic Intervention in PD The results above demonstrate that PDE5 and 4 are both expressed in the human and rat normal tunica albuginea, and the respective PD and PD-like fibrotic plaques, as well as in the cell cultures obtained from these tissues. The results also demonstrate the inhibition of a TGF-β1-induced fibrotic plaque in the rat model of PD, through the reduction of collagen deposition and possibly an increase in apoptosis of the resident fibroblasts and myofibroblasts, by long-term oral administration of the respective PDE5 and cAMP-dependent PDE inhibitors, sildenafil and pentoxifylline, and the NOS substrate, L-arginine. The in vitro effects of both PDE inhibitors and a cGMP analog, 8 Br-cGMP, on fibroblast cultures obtained from the human PD plaque, indicate that these agents may be effective against fibrosis by reducing the relative number of fibroblasts/myofibroblasts through the induction of apoptosis of these cells. We also found that these compounds a) interfere with fibroblast differentiation into myofibroblasts, the cells that are key players in tissue fibrosis, and b) down-regulate the synthesis of collagen I but not collagen m. The effects of sildenafil may be exerted through the inhibition of PDE-5, and in the case of pentoxifylline through a cAMP-dependent PDE, potentially PDE4. The results open a new approach for the treatment of PD and, by extension, tissue fibrosis, based on the use of PDE inhibitors and other enhancers of PDK activity, and possibly of compounds and biologicals that enhance NO synthesis. The reduction of the fibrotic plaque observed in vivo in animals receiving L-arginine, coincides with its effects in preventing experimental ethanol-induced inflammatory and fibrotic changes in liver, kidney, lung, and cardiovascular system (Nanji et al., 2001; Peters et al., 2000; Simko and Simko, 2000; Susic et al., 1999; Song et al., 1998; Bing et al., 2002; Alves et al., 2002). The action of L-arginine may be mediated by the stimulation of NOS activity. This was previously shown by the increase of L-arginine levels in the penis and the improvement of erectile dysfunction in the aging rat by NOS stimulation achieved after a regimen of L-arginine administration of 2.2 g/kg/day (Moody et al., 1997). This dose is within the range normally employed as vasculoprotective for long-term studies in the rat (Bing et al., 2002; Alves et al., 2002). The in vivo and in vitro results showing an inhibition of collagen synthesis and stimulation of apoptosis in the PD-like plaque and in PD cells by both sildenafil and pentoxifylline, are in good agreement with the extensive use pentoxifylline as an antifibrotic agent in liver and vascular fibrosis (Becker et al., 2001; Raetsch et al., 2002; Chen et al., 1999; Tarcin et al., 2003). The fact that the cGMP analog 8-Br-cGMP inhibited collagen I synthesis and induced apoptosis in PD cells suggests that in the case of sildenafil the in vivo effects on the function of the fibroblasts/myofibroblasts in the TA may be mediated by the elevation of cGMP levels. In addition, cGMP analogs, PKG activators, and PDE inhibitors have been shown to inhibit collagen synthesis (Redondo et al., 1998; Wollert et al., 2002), and induce apoptosis (Sirotkin et al., 2000), and some of the PDE inhibitors like sulindac sulfone (Exisulind) are effective as anticancer agents because of their intense pro-apoptotic action (Piazza et al., 2001; Thompson et al., 2000). However, since pentoxifylline did not affect cGMP levels in the human PD fibroblasts, and the drug is considered to be a non-specific inhibitor of cAMP-PDE (Lin et al., 2002c; Liang et al., 1998), and at least in some cell types does not affect cGMP levels (Chen et al., 1999), the increase in cAMP may also have played a role in the antifibrotic effects observed with pentoxifylline. Whether this occurs via the inhibition of PDE4 present in TA and PD remains to be established. Pentoxifylline may also act through its blockade of PDGF-induced activation of the mitogen activated protein kinase system (Souness et al., 2000) and of other cytokine-mediated fibrogenic mechanisms (Raetsch et al., 2002). The daily dose of pentoxifylline used was ⅕ of the oral dose normally employed in rats for the long-term treatment of fibrosis (Chen et al., 1999; Tarcin et al., 2003), and in the case of sildenafil, it is ½ to {fraction (1/7)} of the chronic dosage used in recent studies in rats (Sebkhi et al., 2003). When the 10 mg/kg/day dose is translated into the equivalent dose in humans by correcting for differences in the body weight/skin area (Freireich et al., 1966), it is roughly 1.5 mg/kg which is about the dose ingested by men with an on demand single 100 mg tablet. The selected dose was dispensed in 24 hours and not as a bolus administration, so that concentrations at a given time should be much lower, considering the short half-life (about 4-6 hours) of sildenafil. Therefore, the daily doses of the PDE inhibitors tested in the current work are not supra-pharmacological or associated with toxicity. In addition, it is possible that local administration of either L-arginine or the PDE inhibitors, e.g. by injection into the plaque or in vehicles able to traverse the skin and TA may considerably reduce the effective dosage. It is unknown why administration of L-arginine, which should increase NO synthesis and hence cGMP levels and has been shown to be effective in arresting the growth of the TGF-B1 induced plaque in the rat model of PD, failed to stimulate apoptosis, as could be expected from its effects increasing it in vivo in the smooth muscle of the pulmonary arteries (Wang et al., 1999; Holm et al., 2000). However, the absence of a stimulation of the apoptotic index in the PD plaque by L-arginine may agree with the decrease in apoptosis observed in liver transplants which is in line with the anti-apoptotic effects of NO in certain conditions and tissues (Wang et al., 2002b). In any case, not only cGMP but its down-stream compound in the NO-cGMP cascade, PKG, is also effective in preventing fibrosis and remodeling in balloon-injury and arterial restenosis (Wollert et al., 2002; Chiche et al., 1998), as shown by gene transfer of the PKG cDNA in rats. The results demonstrating the presence of PDE5A and PDE4 in the TA and PD plaque in the human and rat, and in their respective fibroblast cultures, provide a rationale for the anti-fibrotic effects of PDE inhibitors on the PD animal model and on the PD cell cultures. The PDE5A1 and PDE5A2 proteins have been previously localized in human penile corpora cavernosa (Lin et al., 2000a). The PDE5A3 variant was also found in corpora cavernosa and confined to tissues with a smooth muscle or cardiac muscle component, and is twice as sensitive as PDE5A1 to sildenafil, but, as with PDE5A1 and 2, is subject to transcriptional up-regulation by both cAMP and cGMP (Lin et al., 2002a; Turko et al., 1999). As to PDE4, cAMP can activate PKG nearly as effectively as cGMP, so that eventually, the inhibition of PDE4 may cause PKG effects (e.g., counteracting fibrosis) similar to those exerted by as the inhibition of PDE5A. The results reported above indicate that pharmacological interventions aimed at elevating NO, cGMP, or PKG levels, and possibly cAMP, in the penis are of use for the treatment of PD, and potentially, for other fibrotic conditions. This work has not addressed the question on whether intervention would induce regression of an already well-formed plaque, but comparison of multiple gene expression profiles in human PD and the related Dupuytren's disease suggest that both conditions are in a dynamic cell and protein turnover involving replication, differentiation, apoptosis, and collagen and extracellular matrix synthesis and breakdown (Magee et al., 2002b; Gonzalez-Cadavid et al., 2002; Gholami et al., 2002). Therefore, modulation of any of these processes may involute the plaque, as has been observed in generalized fibrotic conditions (Lee et al., 2001; Lai et al., 2000). Example 16 Intensification of Aging-Related Fibrosis in the Arterial Media by iNOS Inhibition In order to determine whether aging per se is associated with an intensification of collagen deposition and a relative loss of SMC in the media from the aorta to the peripheral resistant arteries (Breithaupt-Grogler and Belz, 1999; Robert, 1999; Integan and Schiffrin, 2000), staining was performed on sections from the abdominal aorta, femoral, and brachial arteries as well as from the penile shaft focusing on two peripheral putative resistance arteries: the bulbourethral and dorsal arteries of the penis. FIG. 15A shows that in the media of the dorsal penile artery, few collagen fibers were present in the young rats but were considerably increased in the aged animals, resembling the situation seen in the aorta. Consistent with the model that iNOS may act as antifibrotic agent within the vascular tree, the administration of L-NIL, a specific inhibitor of iNOS activity, for 3 weeks to the aged rats led to a further increase in the collagen fibers within the media of the aorta and the dorsal penile artery. Image analysis was performed in all arteries with the exception of the brachial (FIG. 15B), on 5 animals per experimental group, and 6 sections per animal (3-4 fields per section). In all vessels studied, there was a marked reduction in the SMC/collagen ratio with aging. Following iNOS blockade by L-NIL, there was a further exacerbation in the amount of collagen within the media (with the exception of the bulbourethral artery), suggesting that the decrease in NO production by the inhibition of iNOS leads to an intensification of the aging-related fibrosis. These alterations were not accompanied in the resistant arteries by a significant increase in the intima/media thickness (IMT), whereas in the aorta and femoral the IMT was higher (Table 2). The measurements of the luminal diameter (Table 2) confirmed the clinical observation that the dorsal and bulbo-urethral arteries, with a luminal diameter well below 350 um, fall within the definition of resistance arteries (Intengan and Schriffin, 2000; Moore and Schiffrin, 2001). Example 17 iNOS Induction and Peroxynitrite Deposition in the Arterial Media With Aging All the antibodies used in this work have been validated (Ferrini et al., 2001a, 2002; Vernet et al., 2002; Goettsch et al., 2001), and in the case of the iNOS antibody it was additionally tested in the current work by immunocytochemistry against rat fibroblast cultures (penile tunica albuginea, see Ferrini et al., 2002; Vernet et al. 2002) induced to express iNOS with a cytokine cocktail, producing 130 uM nitrites (Hung et al., 1995). These cells were intensively stained, in comparison to uninduced cells (<10 uM nitrites) that were negative (not shown). Western blots revealed the expected single 130 kDa band in extracts of the induced cells, also detected by the corresponding monoclonal antibody, and this band was absent in aorta extracts from a young iNOS knockout mouse that had received LPS (4 mg/kg) to induce iNOS, whereas the band was visible in the respective extract from the similarly treated wild type animal (not shown). This antibody showed that iNOS is increased with aging in parallel with collagen deposition in the arterial media throughout the vascular tree, confirmed by detection of nitrotyrosinylated proteins. The latter arise from peroxynitrite produced by the reaction between NO and ROS, and therefore are an indirect measure of NOS activity. FIG. 16A shows negligible iNOS expression and nitrotyrosine formation in the dorsal artery of the penis of the young animals, and a remarkable intensification of both processes with aging. The iNOS staining in these vessels was mainly confined to the media and intima. A similar finding was seen in the aorta, brachial, and femoral arteries (not shown). When L-NIL, the inhibitor of iNOS activity, was given, there was a reduction in iNOS expression, which combined with the direct decrease of iNOS activity, led to a reduction in peroxynitrite formation. Quantitation by image analysis confirmed these changes in the resistant dorsal and bulbourethral arteries of the penis (FIG. 16B), as well as in the aorta and femoral arteries (not shown). The brachial artery was not subjected to image analysis. Example 18 Effects of iNOS Inhibition on ROS Production, Apoptosis, and PAI in the Arterial Media Utilizing the Cu/Zn SOD as an indirect marker of ROS, the production of ROS in the arterial media was found to be considerably increased with aging in the femoral, brachial and resistant arteries but not in the aorta, and this process was further increased with iNOS inhibition by L-NIL (FIG. 17A). This was additionally confirmed by image analysis (FIG. 17B), that indicated that L-NIL blockade of iNOS activity raised Cu/Zn SOD by 40 to 50%. The Mn SOD gave similar results from the aorta to the resistant arteries (not shown). Another antioxidant enzyme, heme oxygenase I, demonstrated the same aging related changes in the penile dorsal artery, as observed for both SOD enzymes, but remarkably, L-NIL did not induce a further significant change in the expression of this enzyme (FIG. 18). The localization of virtually all the expression of heme oxygenase-1 was in the arterial adventitia, rather than in the media as seen for the SOD enzymes. The NO/ROS balance was significantly altered throughout the entire arterial media by iNOS inhibition with L-NIL via a reduction in NO synthesis (denoted by peroxynitrite) and a stimulation of ROS formation (denoted by the antioxidant enzymes). Apoptosis of the SMC within the media of the penile resistance arteries increased with aging, and decreased subsequently in the old animals receiving L-NIL treatment (FIG. 19A). The apoptotic index was calculated for both the dorsal and bulbourethral penile arteries by image analysis, and was higher in aged compared to young rats but L-NIL treatment resulted in a reduction in this index (FIG. 19B). Aging alone or in combination with iNOS inhibition affected the expression of PAI-1, a well characterized inhibitor of metalloproteinases (Li et al., 2000; Kaikita et al., 2002). Inhibition of PAI is associated with an increase in collagen fibers due to its interference with metalloproteinases that are involved with the breakdown of collagen. Compared to young animals, PAI expression was considerably increased in the arterial media with aging, and was even further stimulated by iNOS inhibition, as seen in the resistant artery (FIG. 20A). Quantitative image analysis for both the mean intensity of expression (FIG. 20B) and the number of PAI positive cells (FIG. 20B) indicated that the increase in PAI by aging alone was between 2- and 5-fold, respectively. However, the effect of L-NIL on PAI expression in the aged media was negligible (FIG. 20B). These results indicate that the arterial media from the aorta to the small resistant arteries undergoes many of the changes that occur within the corporal tissue with aging, namely: a) a reduction in the SMC/collagen ratio; b) an increase in markers of oxidative stress, and of inhibitors of collagen degradation, such as PAI, which are known pro-fibrotic factors; and c) the spontaneous induction of iNOS, which is believed to act as an anti-fibrotic agent (Vernet et al., 2002; Ferrini et al, 2002; Hochberg et al, 2000). However, the increase in SMC apoptosis in the media of the resistant arteries of the penis, presumably leading to a reduction in the absolute SMC content, contrasts with what has been reported for large vessels such as the aorta and the femoral artery (Connat et al., 2001; Asai et al., 2000), but does agree with the process described in the corporal SMC (Garban et al., 1995; Ferrini et al., 2001a). Our results also confirm the role for NO derived from iNOS produced by the SMCs of the media in combating aging-related fibrosis within the media, as evidenced both by the increase in ROS and an intensification of fibrosis within the media of the arterial wall when iNOS activity is inhibited. The excessive deposition of collagen fibers observed in the arterial media of the aged rats is thought to lead to arterial stiffness or arteriosclerosis in the vascular system. Because of the apoptosis occurring in the SMC, the relative reduction in the SMC/collagen ratio is intensified in the resistant arteries of the penis, in comparison to the larger arteries, e.g. the aorta. This process may be a primary factor involved in the development of essential hypertension, which is very prevalent with aging. In the case of the penile arteries, the data also indicate that a reduction in the ability of penile vessels to relax normally during cavernosal nerve stimulation leading to an erection, may contribute in part to the high prevalence of ED associated with aging. In addition to this aging-related fibrosis of the arterial media (Breithaupt-Grogler and Belz, 1999; Robert, 1999; Integan and Schiffrin, 2000; Formieri et al., 1992), it is well documented (Grein and Schubert, 2002) that similar fibrotic changes occur within the penile corporal sinusoids. The corporal tissue comprises primarily of a syncytium of vascular SMC with an endothelium lining which is biologically and physiologically indistinguishable from the one present in the media and intima of the vascular tree (Krall et al., 1988) and may be considered a highly evolved extension of these arterial tissues. Therefore, insults that afflict the arterial media may also afflict the corporal SMCs, resulting in defective vaso-relaxation in both the corporal tissue (ED) and the arterial tree (hypertension). Indeed, the prevalence of ED and hypertension in man seems to parallel each other as a function of age (Sullivan et al., 2001; Melman and Gingell, 1999), and many disorders that damage one of these vascular tissues also seem to impact the other e.g. diabetes, chronic renal failure, etc. In all these disorders, vascular oxidative stress and fibrosis, leading to arteriosclerosis, are common denominators at the histological and molecular and levels. The results on the abdominal aorta and the rest of the smaller arteries and arterioles are in agreement with previous studies from other groups showing in the aging rat both an intensification of oxidative stress (van der Loo et al., 2000; Demaree et al., 1999) and collagen deposition (Goettsch et al., 2001; Chou et al., 1998; Csiszar et al., 2002), that is the likely cause of the reduction of the SMC/collagen ratio within the media. This alteration, that in the large vessels does not appear to be caused by SMC apoptosis (Connat et al., 2001; Asai et al., 2000), would explain the clinical observation in humans of diminished arterial elasticity associated with aging, which in some instances is compounded by a reduction of the arterial lumen due to media/intimal thickening (Moore and Schiffrin, 2001). The fact that different vessels in the arterial tree, regardless of size or location, seem to experience fibrosis of the media may explain dysfunctional vasorelaxation or impaired perfusion of many organs that occurs with aging (Breithaupt-Grogler and Belz, 1999; Robert, 1999; Integan and Schiffrin, 2000; Formieri et al., 1992; Garban et al., 1995; Ferrini et al., 2001a; Rogers et al., 2003; Berry et al., 2001). The ability of the resistant arteries to relax normally is fundamental for the control of the systemic blood pressure, and as exemplified by the dorsal penile and bulbourethral arteries in this study, they showed an intensification of SMC loss due to apoptosis without a change in IMT, which agrees with has been previously reported for the mesenteric small resistant arteries in hypertension (Rizzoni et al., 2000). Although NO has been shown in animal models to be protective against atherosclerosis and restenosis in the vascular system (Gewaltig and Kojda, 2002; Cheng et al., 2001), and fibrosis throughout the vascular tree and other organs (Ferrini et al., 2002; Vernet et al., 2002; Gewaltig and Kojda, 2002), the concept that NO may prevent aging-related arteriosclerosis is novel. In fact, the pro-apoptotic action of NO (Gewaltig and Kojda, 2002; Kibbe et al., 1999) would suggest that it decreases the SMC/collagen balance through increased cell death. We have found in the aged animals treated with L-NIL an association between NOS inhibition and subsequent reduction of nitrotyrosine formation, with a decrease of apoptosis, which would suggest that NO does cause some SMC loss in the penile resistant arteries similar to what has been previously assumed to occur in the corpora cavernosa (Ferrini et al., 2001a). However, an increased apoptotic index may be balanced by a stimulation of cell replication or tissue remodeling (Ingengan and Schiffrin, 2001), and what really matters physiologically is the net balance between both processes. In the data above, the relative number of SMC in the arterial media (represented by the smooth muscle/collagen ratio), was severely reduced when NO synthesis was diminished by L-NIL. This, together with the well known effects of NO in scavenging the profibrotic compound, ROS, thereby decreasing collagen synthesis and down-regulating its breakdown (see Ferrini et al., 2002; Vernet et al., 2002), would support the view of an overall beneficial role of NO in preventing arterial stiffness and loss of compliance of the corpora cavernosa. A final question is whether collagen accumulation with aging is at least partially mediated via the regulation of PAI-1, TIMP1 and other metalloproteinase inhibitors (Li et al., 2000; Kaikita et al., 2002), that increase in different types of fibrosis. The current results with PAI, combined with previous data where we observed considerable metalloproteinase and PAI mRNA expression in the fibrotic plaque of Peyronie's disease in the human and rat (Magee et al., 2002a), would suggest that although the increase in the pro-fibrotic PAI may induce a compensatory elevation of metalloproteinase levels, the enzyme would remain inhibited and the net result would be an impaired collagen breakdown. In conclusion, the results indicate that within the arterial system and the cavernosal tissue it may be possible to pharmacologically modulate a) the NO/ROS balance with NO donors or other NO generators together with antioxidants, and b) the PAI/MMP balance with agents modifying their relative expression. Such novel therapies may constitute viable approaches for the prevention and/or therapy of vascular disorders that involve the arterial media and the corpora. Example 19 Gene Therapy With iNOS cDNA All studies throughout this section, unless specifically indicated, are performed in the rat model where the PD-like plaque is initiated by the injection of TGF-β1 (0.5 ug) into the TA. TGF-β1 transcriptionally amplifies its own synthesis, allowing for a single injection. Saline-injected TA are used as controls. The AdV-CMV-iNOS construct has been prepared by subcloning the iNOS cDNA driven by the strong CMV promoter (Garban et al., 1997), from a plasmid construct into an AdV plasmid vector, and purifying the AdV construct, as previously described for PnNOS (Magee et al., 2002a). This AdV vector is replication-defective and helper-dependent, and therefore is non-infectious and totally innocuous. In addition, it lacks virtually all the original viral sequences that may be immunogenic. This AdV construct can be transfected into the TA, and it has been cloned and utilized for other therapeutic purposes in the penis (Magee et al., 2002a). Rats are injected in the TA at the same site as the TGF-β1 was injected 5 days earlier (as evidenced by a non-absorbable suture) with 108 and 109 vp of either AdV-CMV-iNOS in 50 ul saline, or with vehicle (saline) only. This 5-day waiting period between the TGF-β1 injection and the cDNA construct avoids any interference of the viral preparation with the injected TGF-β1, and/or its dispersion by the electroporation applied to enhance transfection of the iNOS construct. The resulting 4 groups of rats are allowed to develop the plaque for 40 more days, sacrificed, and the area around the plaque is excised, fixed, paraffin-embedded, and sectioned (Ferrini et al., 2002, Vernet et al., 2002). In another 2 groups of rats injected with TGF-β1 to induce a plaque, the cDNA construct and saline are injected 45 days after the TGF-β1 injection (when the plaque has already formed) and 30 days later the animals are sacrificed. In the “early” treatment groups (iNOS given 5 days after TGF-β1 injection), the TA of the iNOS-treated animals shows, in comparison with controls: 1) a decrease in the size of the plaque as evidenced by Masson, collagen I/III staining, and hydroxyproline content; 2) a higher expression of iNOS and nitrotyrosine; 3) decrease of ROS; and 4) increase in the apoptotic index of the fibroblasts/myofibroblasts. In the “late” treatment group, where the iNOS is injected 45 days after TGF-β1 injection, at least some regression of the plaque is obtained. Example 20 Oral NO Donors or NOS Substrate Plaques are induced in the TA of rats by TGF-β1 injection (Ferrini et al., 2002). Drinking water containing molsidomine (N-ethoxycarbonyl-3-morpho-linosydnomine), at 0.12 g/l (Benigni et al., 1999) (freshly prepared each day) is given to 2 groups of rats, an early and a late treatment group. The dose of molsidomine used is based on the report in which it was utilized for 22 days to protect against tubulo-interstitial injury in a rat model of chronic glomerular disease (Uckert et al., 2001), and is calculated to be equivalent to approximately 15 mg/kg/day in the rat. In the case of L-arginine, it is given only as a late treatment, but at 2 doses: 22.5 and 10.0 g/l (in drinking water) (2 groups). Previously, the 22.5 g/l dose of L-arginine was used for 45 days to elevate NOS activity in the rat penis (Moody et al., 1997), and to inhibit the plaque with the early treatment is equivalent to roughly 2.8 g/kg/day. Example 21 Oral PDE Inhibitors to Regress the PD Plaque Sildenafil (specific PDE5 inhibitor), and pentoxifylline (non-specific PDE inhibitor), are given at doses of 100 mg/l in the drinking water, as well as a control (drinking water only), beginning on day 45 (3 groups). The study may be repeated at double or possibly quadruple the dosage above (2 groups). Reduction in plaque size was observed with both sildenafil and pentoxifylline during the entire time of plaque development (‘early treatment’), and this type of treatment may be as effective in regressing the plaque (‘late treatment’). Eleven PDE mRNAs for the respective isoforms have so far been identified by RT/PCR in the human (Kim et al., 2000). Due to the fact that pentoxifylline is more effective than sildenafil at inhibiting apoptosis in the PD plaque, it is likely that more than one PDE gene product may be involved in plaque development, and the pure PDE4 inhibitor, rolipram (Uckert et al., 2001) may identify a related, relevant PDE. The increase in cAMP may act directly, or through stimulating the synthesis of cGMP (Kim et al., 2000). Rolipram, is given to early and late treatment groups (2 groups), at the same dose, in order to determine whether increasing cAMP levels is as, or more, effective than cGMP. Example 22 Gene Therapy with PKG The AdV-PKG (wild type) and AdV-PKGcat (mutated) are injected into the TA (2 groups). The constitutively active PKG1 mutant consists of the carboxy-terminal catalytic domain without the amino-terminal regulatory domain where cGMP binds (Wollert et al., 2002). Both the wild type and mutated constructs are obtained from Dr. Stefan Janssens (Center for Transgene Technology and Gene Therapy, University of Leuven, Belgium). Example 23 Screening of Other cGMP-Dependent PDE Isoforms Tissues from human normal TA and PD plaque preserved in RNA later (Magee et al., 2002b; Ferrini et al., 2002) or the previously isolated RNAs from these tissues, conserved at −80° C., are used. In the case of the rat model, a 2-3 mm transverse section is obtained at the site of saline or TGF-β1 injection 45 days after plaque initiation. RNA is isolated from 2 groups of human and 2 groups of rat tissues. Example 24 Oral Antioxidant The antioxidant vitamin E (α-tocopherol) is given in a specially prepared oral diet, so that the animal receives in an early treatment phase approximately 200 IU/kg/bw/day, whereas controls receive the normal diet containing less than 20 IU/kg (Gonca et al., 2000). The third group (3 groups) receive twice a day an intramuscular injection (10 mg/kg) of another antioxidant compound that ameliorates oxidative stress and lipid peroxidation, the glutathione precursor S-adenosyl-L-methionine (SAM) (Muriel et al., 1998b). Depending on which antioxidant is more efficacious in the early treatment, a late treatment beginning on day 45 after TGF-β1 injection and lasting for 30 days is performed with the selected compound compared to a control group with normal diet (2 groups). Example 25 Effect of Obliterating iNOS on Collagen Breakdown. Plaque in the iNOS Knockout The PD-like plaque is induced with TGF-β1 given into the TA of the iNOS knock-out mouse, utilizing the wild type mouse as a control, (2 groups, n=6). 45 days after the injection of TGF-β1, the mice are sacrificed and the tunical tissues is either fixed and sectioned for immunohistochemistry (n=3) or used for RNA isolation (n=3). The experiment is repeated, but this time, 8 days before sacrifice, the collagen I promoter plasmid is injected and electroporated (Magee et al., 2002a) (2 groups; n=3). Animals are sacrificed and fresh tunical plaque tissue obtained for β-galactosidase expression and zymography. Example 26 Modulation of MMP Through Thymosin Peptides. Treatment With Thymosin β Thymosin β4 and 10 are given daily intraperitoneally as a late treatment at 60 ug/day, every other day (2 groups) (Sosne et al., 2002). Such treatment with thymosin-β4 (the most abundant thymosin) has been used for promoting healing of dermal wounds (Sosne et al., 2002)). Plasmid preparations of a cDNA encoding both peptides (200 ug/rat) are also given by injection/electroporation to the TA (2 groups), as a late treatment (i.e. 45 days after the TGF-β1 injection, to induce the PD like plaque). All of the COMPOSITIONS, METHODS and APPARATUS disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the COMPOSITIONS, METHODS and APPARATUS and in the steps or in the sequence of steps of the methods described herein without departing from the concept, spirit and scope of the invention. More specifically, it will be apparent that certain agents that are both chemically and physiologically related may be substituted for the agents described herein while the same or similar results would be achieved. 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Westenfeld R, Gawlik A, de Heer E, Kitahara M, Abou-Rebyeh F, Floege J, Ketteler M (2002) Selective inhibition of inducible nitric oxide synthase enhances intraglomerular coagulation in chronic anti-Thy 1 nephritis. Kidney Int 61(3):834-8. Windmeier C, Gressner A M. Pharmacological aspects of pentoxifylline with emphasis on its inhibitory actions on hepatic fibrogenesis. Gen Pharmacol 1997 August;29(2): 181-96 Wollert K C, Fiedler B, Gambaryan S, Smolenski A, Heineke J, Butt E, Trautwein C, Lohmann S M, Drexler H (2002) Gene transfer of cGMP-dependent protein kinase I enhances the antihypertrophic effects of nitric oxide in cardiomyocytes. Hypertension 39(1):87-92. Wu J, Zern M A (2000) Hepatic stellate cells: a target for the treatment of liver fibrosis. J Gastroenterol 35(9):665-72. Yaguchi T, Fukuda Y, Ishizaki M, Yamanaka N. Immunohistochemical and gelatin zymography studies for matrix metalloproteinases in bleomycin-induced pulmonary fibrosis. Pathol Int. 1998 December;48(12):954-63. Yamasaki K, Edington H D J, Mc Closky C, Tzeng E, Lizanova A, Kovesdi I, Steed D L, Billiar T R (1998) Reversal of impaired wound repair in iNOS-deficient mice by topical adenoviral-mediated iNOS gene transfer. Am J Physiol 101:967-971. Zalba G, Beaumont J, San Jose G, Fortuno A, Fortuno M A, Diez J. Vascular oxidant stress: molecular mechanisms and pathophysiological implications. J Physiol Biochem. 2000; 56:57-64 Zhang H Y, Phan S H (1999) Inhibition of myofibroblast apoptosis by transforming growth factor beta (1). Am J Respir Cell Mol Biol 21(6):658-65. Zuk P A, Zhu M, Mizuno H, Huang J, Futrell J W, Katz A J, Benhaim P, Lorenz H P, Hedrick M H (2001) Multilineage cells from human adipose tissue: implications for cell-based therapies. Tissue Engineering 7(2): 211-228. TABLE 1 Dupuytren Peyronie Protein/gene n* Mean ± SE n** Mean ± SE matrix 9 29 ± 10 2 4.7 ± 2.6 metalloproteinase 2 matrix 2 50.8 ± 0.8 metalloproteinase 9 thymosin beta-10 9 5.9 ± 2.6 5 5.5 ± 1.3 (TMSB10) thymosin beta 4 8 5.9 ± 1.5 5 2.5 ± 0.9 prothymosin alpha 2 2.6 ± 0.0 2 6.2 ± 3.8 osteoblast specific 5 5.6 ± 1.4 3 4.3 ± 0.5 factor 1 (OSF-1) osteoblast specific 4 26.7 ± 12.7 factor 2 (OSF2) rho GDP dissociation 6 3.5 ± 1.4 2 18.3 ± 2.4 inihibitor 1 (RHO-GDI 1) n* = 9 patients n** = 10 patients TABLE 2 INTIMA MEDIA THICKNESS YOUNG OLD OLD + L-NIL (μm) (μm) (μm) AORTA 73.4 ± 8.6** 93.0 ± 6.6** 85.2 ± 6.6 FEMORAL 49.7 ± 7.1 63.5 ± 2.4 51.8 ± 4.6 PENILE DORSAL 17.0 ± 2.3 18.6 ± 1.4 23.6 ± 3.3 BULBO URETHRAL 10.5 ± 1.3 10.1 ± 1.6 9.9 ± 0.7 LUMEN DIAMETER YOUNG OLD OLD + L-NIL (μm) (μm) (μm) PENILE DORSAL 100.8 ± 13.7 118.7 ± 6.6 105.5 ± 16. BULBO URETHRAL 40.1 ± 5.6 42.6 ± 6.8 47.3 ± 6.6 | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field The present methods and compositions relate to the field of Peyronie's disease, arteriosclerosis and other fibrotic conditions. More particularly, the method and compositions concern use of phosphodiesterase (PDE) inhibitors and modulators of nitric oxide, reactive oxygen species and metalloproteinases in the treatment of such conditions. In particular embodiments, the inhibitors inhibit type 4 and/or type 5 PDEs. 2. Description of Related Art Peyronie's disease (PD) is a fibromatosis (Hellstrom and Bivalacqua, 2000; Schwarzer et al., 2001; Jarow et al., 1997; Devine et al., 1997) of the tunica albuginea (TA), the specialized lining of the corpora cavernosa of the penis. Clinically, this usually leads to penile deformation (curved penis during erection), pain, and quite frequently erectile dysfunction. The initiating event is believed to be an external force to the erect penis that results in an injury to the TA of the corpora and the TA fails to heal normally (Jarow et al., 1997; Devine et al., 1997; Diegelmann, 1997; Sherratt and Dallon, 2002). In the detumesced state, the only indication of the disease is the palpation of a knot or scar within the TA, which in its most severe state presents as a calcified plaque. PD affects about 5% of men in the USA, and translating into about 3-4 million affected American males. Although the condition is not always associated with erectile dysfunction, patients usually present to the physician with either recognition of a palpable plaque on the penile shaft, pain with tumescence, impotence and/or difficulty with intromission that is due to curvature of the erect penis. Since the disorder was first described in 1743, no medical treatment has ever proven to be beneficial in combating the condition, thereby highlighting the need to develop novel approaches to combat this disorder. There may also be a genetic predisposition to developing PD, since it is associated with other contractures such as Dupuytren's disease (palmar fascia; 10-20% incidence or more in PD) (Connelly, 1999) and Ledeshore's disease (plantar fascia). The pathophysiology is characterized by localized disruption of the TA, increased microvascular permeability, persistent fibrin (deficient fibrinolysis) and collagen deposition, perivascular inflammation, disorganization and loss of elastic fibers (release of elastase by macrophages), disorganized collagen bundles, and an increase in TGF-β1 synthesis. This represents impairment in the repair process that leads to persistent fibrosis and a loss of elasticity of the TA. PD can rarely be alleviated by medical treatment with anti-inflammatory agents (corticosteroids, antihistamine), antioxidants (vitamin E, superoxide dismutase), collagen breakdown (collagenase), Ca channel blockers (verapamil), and other antifibrotic compounds (colchicine, Potaba: K aminobenzoate) (Hellstrom and Bivalacqua, 2000). In most cases, surgery is the only available option to correct the deformity and alleviate the pain so that normal sexual activity can be resumed. A need exists for non-surgical methods of treatment of Peyronie's disease and other medical conditions in which fibrosis is important. Fibrotic disease is not limited to the reproductive organs, but can be found in other tissues, such as cardiovascular tissues. Both erectile dysfunction (ED) and cardiovascular disease, particularly hypertension, are prevalent in the aging male (Kloner et al., 2002; Sullivan et al., 2001; Melman et al., 1999). One of the underlying causes of hypertension is arteriosclerosis, or arterial stiffness, due to an acquired fibrosis of the media of the arterial wall (Breithaupt-Grogler and Belz, 1999; Robert, 1999; Intengan and Schiffrin, 2000, 2001; Formieri et al., 1992). Arteriosclerosis is significantly associated with aging, and is recognized by an increase in collagen, and in some cases by a loss of smooth muscle cells (SMC) within the arterial media, which results in a decrease in the SMC/collagen ratio, often accompanied by endothelial dysfunction (Cai and Harrison, 2000). The pathogenesis of aging associated ED, both in the human and rat, is mostly related to the loss of SMC in the penile corpora cavernosa by apoptosis, with a corresponding increase in collagen fibers (Melman and Gingell, 1999; Cai and Harrison, 2000; Melman, 2001; Garban et al., 1995; Ferrini et al., 2001a). The clinical result of this aging process in the penis is defective cavernosal SMC relaxation leading to veno-occlusive dysfunction (Breithaupt-Grogler and Belz, 1999; Rogers et al., 2003), the most common cause of ED. In the arterial tree, excessive collagen deposition in the media, with or without loss of SMC, leads to defective vaso-relaxation and clinically may present as hypertension (Breithaupt-Grogler and Belz, 1999; Robert, 1999; Intengan and Schiffrin, 2000, 2001). Because the penis may be considered a specialized extension of the vascular tree, the common alterations observed in the SMC of both the penis and peripheral vascular system in the aging male, leading to ED and hypertension, respectively, suggest that both conditions may share a common etiology. A need exists for effective methods to treat and/or ameliorate the symptoms of a variety of fibrotic disease, such as PD, ED and arteriosclerosis. No effective method of treatment currently exists that is directed towards the molecular pathways underlying excessive collagen deposition. | <SOH> SUMMARY OF THE INVENTION <EOH>Certain embodiments of the present invention fulfill an unresolved need in the art, by providing novel methods for therapeutic treatment of Peyronie's disease, erectile dysfunction, arteriosclerosis and other fibroses. In some embodiments, PD plaques and/or other fibrotic conditions can be pharmacologically arrested or reduced in size, by decreasing collagen synthesis and inducing myofibroblast apoptosis by increasing the NO/ROS ratio, the levels of cGMP, or the activation of its effector, PKG in the TA and/or stimulating collagen degradation by activating the MMPs and/or down-regulating the expression of the MMP inhibitors (TIMP), by increasing NO/cGMP levels and/or the thymosins in the TA. Particular embodiments of the invention may be directed towards increasing levels of cGMP and/or cAMP by selective inhibition of phosphodiesterase (PDE) isoforms. PDE isoforms of interest in the TA and in PD plaque tissues include PDE5A-3, PDE4A, PDE4B and PDE4D. As non-limiting examples, pentoxifylline and similar compounds act as a non-specific cAMP-PDE inhibitor and increase cAMP levels, while sildenafil and similar compounds selectively inhibit PDE5A and increase cGMP levels. Other embodiments may involve increasing NO levels, for example by administering L-arginine, a stimulator of NOS activity. As shown in the following examples, pentoxifylline, sildenafil and L-arginine all act to reduce the expression of collagen I and α-smooth muscle actin. Long-term administration of nitrergic agents, such as pentoxifylline, sildenafil and L-arginine may be of use to reduce PD plaque size and collagen/fibroblast ratio and may reverse or prevent the further development of the fibrosis observed in PD, ED, arteriosclerosis and other fibrotic conditions. | 20040213 | 20120313 | 20050421 | 59706.0 | 1 | BETTON, TIMOTHY E | METHODS OF USE OF INHIBITORS OF PHOSPHODIESTERASES AND MODULATORS OF NITRIC OXIDE, REACTIVE OXYGEN SPECIES, AND METALLOPROTEINASES IN THE TREATMENT OF PEYRONIE'S DISEASE, ARTERIOSCLEROSIS AND OTHER FIBROTIC DISEASES | SMALL | 0 | ACCEPTED | 2,004 |
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10,779,435 | ACCEPTED | Apparatus for preventing backlash of spool used in baitcasting reel | Disclosed is an apparatus for preventing backlash of a spool used in a baitcasting reel. A movable cam 20 assembled to a stationary cam 10 secured to a spool shaft moves in a direction parallel with the spool shaft, when a revolution of the spool is increased. A braking plate 30 approaches a permanent magnet 2a of a spool cover, so that the spool is smoothly and precisely braked. | 1. An apparatus for preventing backlash of a spool used in a baitcasting reel, the apparatus comprising: a stationary cam including an opening formed at a center thereof through which a shaft of the spool passes, in which a boss of the spool is inserted into the opening to fix the stationary cam, and at least two first protruded portions formed at an outer periphery thereof, the first protruded portions having an inclined surface at a lower portion thereof; a movable cam including further protruded portions corresponding to the first protruded portions, bosses formed under a bottom of the movable cam, and an opening formed at a center of the cam through which the spool shaft passes, the first protruded portions having an inclined surface abutting against the inclined surface of the further protruded portions of the stationary cam; a breaking plate including holes for receiving the bosses of the movable cam and an opening formed at the center of the plate through which the spool shaft passes, in which the braking plate is affected by a magnetic force of a permanent magnet so that braking force is applied to the spool; and a spring, secured to the spool shaft by a washer and a snap ring, for compressing the movable cam against the stationary cam. 2. (canceled) | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fishing reel, and more particularly, to an apparatus for preventing backlash of a spool used in a baitcasting reel. 2. Background of the Related Art In baitcasting reels, if a flying speed of a sinker containing bait does not coincide with an unwinding speed of a fishing line from a spool upon casting, there is a phenomenon that the excessively unwound fishing line is tangled around the spool. In order to prevent the phenomenon, a centrifugal brake for to controlling a rotating speed of the spool is utilized. It is difficult for the conventional centrifugal brake to precisely control braking force. Further, a brake shoe and a braking ring are worn away. Therefore, it has been proposed a structure for preventing the backlash of the spool by use of a permanent magnet and a braking plate, in which a slider assembled to an inclined surface of the spool is moved toward the permanent magnet by centrifugal force generated from the rotation of the spool, thereby braking the spool. Such a structure is expensive and complicated, and thus its assembly is not easy. SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a backlash preventing apparatus for a baitcasting reel that substantially obviates one or more problems due to limitations and disadvantages of the related art. An object of the present invention is to provide an apparatus for preventing backlash of a spool, in which a decreased phenomenon of carry distance can be improved and a durability of components can be remarkably increased. To achieve the object and other advantages, according to one aspect of the present invention, there is provide an apparatus for preventing backlash used in a baitcasting reel, the apparatus comprising: a stationary cam including an opening formed at a center thereof through which a shaft of a spool passes, in which a boss of the spool is inserted into theopening to fix the stationary cam, at least two protruded portions formed at an outer periphery thereof, the protruded portion having an inclined surface at a lower portion thereof; a movable cam including protruded portions corresponding to the protruded portions, bosses formed under a bottom of the movable cam, and an opening formed at a center of the cam through which the spool shaft passes, the protruded portion having an inclined surface abutting against the inclined surface of the protruded portion of the stationary cam; a braking plate including holes for receiving bosses of the movable cam and an opening formed at a center of the plate through which the spool shaft passes, in which the braking plate is affected by magnetic force of the permanent magnet so that braking force is applied to the spool; and a spring, secured to the spool shaft by a washer and a snap ring, for compressing the movable cap against the stationary cam. Alternatively, the braking plate may be replaced by a braking ring of a cylinder tube shape, and the permanent magnet of the spool cover 2 may be replaced by a plurality of permanent magnets arranged around a spool cover in a circle and permanent magnets secured to a ring gear. The braking ring moves between the permanent magnets and the permanent magnets, thereby preventing the backlash of the spool. It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings: FIGS. 1 and 2 are exploded perspective views of an apparatus for preventing backlash of a spool according to one preferred embodiment of the present invention; FIGS. 3 and 4 are cross-sectional views of an apparatus for preventing backlash of a spool according to one preferred embodiment of the present invention; and FIGS. 5 and 6 are cross-sectional views of an apparatus for preventing backlash of a spool according to alternative embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment according to the present invention will now be explained with reference to the accompanying drawings. Referring to FIG. 1, an apparatus for preventing backlash of a spool for used in a baitcasting reel according to one preferred embodiment of the present invention includes a stationary cam 10, a movable cam 20 assembled to the stationary cam 10, and a braking plate 30 fixed to the movable cam 20. The stationary cam 10 is formed with an opening 11 formed at center of the cam through which a shaft 1b of a spool 1 passes, and a boss 1a of the spool 1 is inserted into the opening 11 to fix the stationary cam 10. As shown in the accompanying drawings, the stationary cam 10 is provided at an outer periphery thereof with at least two protruded portions 12. Three protruded portions 12 are provided in this embodiment, but four or five protruded portions 12 may be provided. The protruded portion 12 has an inclined surface 13 at a lower portion of the protruded portion. The movable cam 20 includes protruded portions 21 corresponding to the protruded portions 12. The protruded portion 21 has an inclined surface 22 abutting against the inclined surface 13 of the protruded portion 12 of the stationary cam 10. Also, the movable cam 20 has bosses 23 formed under a bottom of the movable cam 20 and inserted into holes 32 of the braking plate 30, and an opening 24 at a center of the cam 20 through which the spool shaft 1b passes. The braking plate 30 has holes 32 for receiving bosses 23 of the movable cam 20, and an opening 31 at a center of the plate 30 through which the spool shaft 1b passes. The braking plate is made of a nonmagnetic material, such as aluminum and an alloy of aluminum, and is called as a magnet plate in the industry. If the stationary cam 10, the movable cam 20 and the braking plate 30 are assembled to the reel, one end of the spool shaft 1b is inserted into a spring 40 in such a way that the spring is contacted to the movable cam 20. The spring 40 is secured to the spool shaft 1b by a washer 50 and a snap ring 60. FIG. 3 shows a case where the spring 40 is slightly compressed. The movable cap 20 with the braking plate 30 fixed is not released from the stationary cam 10 by itself. When a fisher casts bait in the state shown in FIG. 3, the movable cam 20 is rotated with the stationary cam 10, with it being not detached from the stationary cam 10, at the early stage in which the spool 1 is rotated. Immediately after the spool 1 is rotated at high speed, the inclined surface 22 of the protruded portion 22 of the movable cam 20 is slid and detached from the inclined surface 13 of the protruded portion 12 of the stationary cam 10. At that time, the movable cam 20 surpasses compression force of the spring 40, and moves toward a spool cover 2 along the spool shaft 1b. Then, when a rotating speed of the spool 1 reached to the maximum level, the movable cam 20 moves to a position closely adjacent to a permanent magnet 2a of the spool cover 2, as shown in FIG. 4. Therefore, the braking plate 30 is affected by magnetic force of the permanent magnet 2a so that braking force is applied to the spool 1. Accordingly, the rotation of the spool 1 is slowly and smoothly reduced, thereby preventing the backlash of the spool 1. When the rotation of the spool 1 is reduced without producing the backlash, the movable cam 20 is slowly moved toward the stationary cam 10 by the compression force of the spring 40, and the braking plate 30 is returned to its original position together with the movable cam 20, as shown in FIG. 3. Specifically, if the spool 1 is rotated at high speed, the braking plate 30 is moved toward the permanent magnet 2a together with the movable cam 20, as shown in FIG. 4, so that the rotation of the spool 1 is reduced without producing the backlash. At the same time the spool 1 is rotated at medium and low speed, the braking plate 30 is moved away from the permanent magnet 2a, and is returned to its original position, as shown in FIG. 3. With the structure, the movable cam 20 is not detached from the stationary cam 10 by centrifugal force. The movable cam 20 is stationary at the initial stage, but is moved in parallel with the spool shaft 1b by the movement of inertial when the spool 1 is rotated at the high speed. If a control member 4 assembled to a side cover 5 is rotated, a slide cam 3 is rotated, and a spiral wing 3a of the slide cam 3 is inserted into a groove 6a formed at a bushing 6 of the spool cover 2. The spool cover 2 and the bushing 6 can be moved toward the braking plate 30, as shown in FIG. 4. The reason is that it is to precisely control operating force of the magnet brake. The present invention can be applied to a centrifugal magnetic brake structure, instead of the shown structure of such magnet plate. FIGS. 5 and 6 show alternative embodiments of the present invention. These alternative embodiments are substantially similar to the first embodiment, except that the braking plate 30 is replaced by a braking ring 30a of a cylinder tube shape. The braking ring 30a is secured to an edge of a movable cam 20a, as shown in FIGS. 5 and 6. The permanent magnet 2a of the spool cover 2 of the first embodiment is replaced by a plurality of permanent magnets 3-2 and 3-2a arranged around a spool cover 301 in a circle, and permanent magnets 8a and 8b secured to a ring gear 7a. According to the alternative embodiments, if the spool 1 is rotated at high speed, the movable cam 20a is detached from the stationary cam 10, as shown in FIGS. 5 and 6. The braking ring 30a moves between the permanent magnets 3-2 and 302a and the permanent magnets 8a and 8b. Therefore, the alternative embodiments perform the same operation as that of the first embodiment, thereby preventing the backlash of the spool 1. The arrangement of the permanent magnets 3-2, 3-2a, 8a and 8b can be applied to a centrifugal magnetic brake structure. Therefore, various structure of the permanent magnets 2a, 3-2, 3-2a, 8a and 8b can be utilized in the apparatus of the present invention, and the present invention is characterized by the braking plate 30 and the braking ring 30a. With the structure of the apparatus, the movable cam 20 is not detached from the stationary cam 10 by centrifugal force. The movable cam 20 is stationary at the initial stage, but is moved in parallel with the spool shaft 1b by the movement of inertial when the spool 1 is rotated at the high speed. The apparatus has a simple structure in relation to the magnetic brake structure employing the centrifugal force, and so its cost is inexpensive. Further, the operation of the apparatus can be permanently guaranteed. Accordingly, the rotation of the spool is controlled more ideally in relation to the prior art, and a decreased phenomenon of carry distance can be improved. Further, a durability of components related to the apparatus for preventing the backlash can be remarkably increased. The forgoing embodiments are merely exemplary and are not to be construed as limiting the present invention. The present teachings can be readily applied to other types of apparatus. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a fishing reel, and more particularly, to an apparatus for preventing backlash of a spool used in a baitcasting reel. 2. Background of the Related Art In baitcasting reels, if a flying speed of a sinker containing bait does not coincide with an unwinding speed of a fishing line from a spool upon casting, there is a phenomenon that the excessively unwound fishing line is tangled around the spool. In order to prevent the phenomenon, a centrifugal brake for to controlling a rotating speed of the spool is utilized. It is difficult for the conventional centrifugal brake to precisely control braking force. Further, a brake shoe and a braking ring are worn away. Therefore, it has been proposed a structure for preventing the backlash of the spool by use of a permanent magnet and a braking plate, in which a slider assembled to an inclined surface of the spool is moved toward the permanent magnet by centrifugal force generated from the rotation of the spool, thereby braking the spool. Such a structure is expensive and complicated, and thus its assembly is not easy. | <SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, the present invention is directed to a backlash preventing apparatus for a baitcasting reel that substantially obviates one or more problems due to limitations and disadvantages of the related art. An object of the present invention is to provide an apparatus for preventing backlash of a spool, in which a decreased phenomenon of carry distance can be improved and a durability of components can be remarkably increased. To achieve the object and other advantages, according to one aspect of the present invention, there is provide an apparatus for preventing backlash used in a baitcasting reel, the apparatus comprising: a stationary cam including an opening formed at a center thereof through which a shaft of a spool passes, in which a boss of the spool is inserted into theopening to fix the stationary cam, at least two protruded portions formed at an outer periphery thereof, the protruded portion having an inclined surface at a lower portion thereof; a movable cam including protruded portions corresponding to the protruded portions, bosses formed under a bottom of the movable cam, and an opening formed at a center of the cam through which the spool shaft passes, the protruded portion having an inclined surface abutting against the inclined surface of the protruded portion of the stationary cam; a braking plate including holes for receiving bosses of the movable cam and an opening formed at a center of the plate through which the spool shaft passes, in which the braking plate is affected by magnetic force of the permanent magnet so that braking force is applied to the spool; and a spring, secured to the spool shaft by a washer and a snap ring, for compressing the movable cap against the stationary cam. Alternatively, the braking plate may be replaced by a braking ring of a cylinder tube shape, and the permanent magnet of the spool cover 2 may be replaced by a plurality of permanent magnets arranged around a spool cover in a circle and permanent magnets secured to a ring gear. The braking ring moves between the permanent magnets and the permanent magnets, thereby preventing the backlash of the spool. It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. | 20040213 | 20051115 | 20050818 | 94500.0 | 0 | MARCELO, EMMANUEL MONSAYAC | APPARATUS FOR PREVENTING BACKLASH OF SPOOL USED IN BAITCASTING REEL | SMALL | 0 | ACCEPTED | 2,004 |
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10,779,532 | ACCEPTED | Inhibitors of c-jun N terminal kinases (JNK) and other protein kinases | The present invention provides compounds of formula I: where R1 is H, CONH2, T(n)—R, or T(n)—Ar2, n may be zero or one, and G, XYZ, and Q are as described below. These compounds are inhibitors of protein kinase, particularly inhibitors of JNK, a mammalian protein kinase involved cell proliferation, cell death and response to extracellular stimuli. The invention also relates to methods for producing these inhibitors. The invention also provides pharmaceutical compositions comprising the inhibitors of the invention and methods of utilizing those compositions in the treatment and prevention of various disorders. | 1. A compound having the formula wherein: X—Y—Z is selected from one of the following: R1 is H, CONH2, T(n)—R, or T(n)—Ar2; R is an aliphatic or substituted aliphatic group; n is zero or one; T is C(═O), CO2, CONH, S(O)2, S(O)2NH, COCH2 or CH2; each R2 is independently selected from hydrogen, —R, —CH2OR, —CH2OH, —CH═O, —CH2SR, —CH2S(O)2R, —CH2(C═O)R, —CH2CO2R, —CH2CO2H, —CH2CN, —CH2NHR, —CH2N(R)2, —CH═N—OR, —CH═NNHR, —CH═NN(R)2, —CH═NNHCOR, —CH═NNHCO2R, —CH═NNHSO2R, -aryl, -substituted aryl, —CH2(aryl), —CH2(substituted aryl), —CH2NH2, —CH2NHCOR, —CH2NHCONHR, —CH2NHCON(R)2, —CH2NRCOR, —CH2NHCO2R, —CH2CONHR, —CH2CON(R)2, —CH2SO2NH2, —CH2(heterocyclyl), —CH2(substituted heterocyclyl), -(heterocyclyl), or -(substituted heterocyclyl); each R3 is independently selected from hydrogen, R, COR, CO2R or S(O)2R; G is R or Ar2; Ar1 is aryl, substituted aryl, aralkyl, substituted aralkyl, heterocyclyl, or substituted heterocyclyl, wherein Ar1 is optionally fused to a partially unsaturated or fully unsaturated five to seven membered ring containing zero to three heteroatoms; Q—NH is wherein the H of Q—NH is optionally replaced by R3; A is N or CR3; U is CR3, O, S, or NR3; Ar2 is aryl, substituted aryl, heterocyclyl or substituted heterocyclyl, wherein Ar2 is optionally fused to a partially unsaturated or fully unsaturated five to seven membered ring containing zero to three heteroatoms; wherein each substitutable carbon atom in Ar2, including the fused ring when present, is optionally and independently substituted by halo, R, OR, SR, OH, NO2, CN, NH2, NHR, N(R)2, NHCOR, NHCONHR, NHCON(R)2, NRCOR, NHCO2R, CO2R, CO2H, COR, CONHR, CON(R)2, S(O)2R, SONH2, S(O)R, SO2NHR, or NHS(O)2R, and wherein each saturated carbon in the fused ring is further optionally and independently substituted by ═O, ═S, ═NNHR, ═NNR2, ═N—OR, ═NNHCOR, ═NNHCO2R, ═NNHSO2R, or ═NR; and wherein each substitutable nitrogen atom in Ar2 is optionally substituted by R, COR, S(O)2R, or CO2R. 2. The compound of claim 1 where G is Ar1. 3. The compound of claim 2 having the formula 4. The compound of claim 3 where Q—NH is selected from: 5. The compound of claim 4 where R1 is alkoxyalkyl, alkoxycarbonylalkyl, hydroxyalkyl, pyridinylalkyl, alkoxycycloalkyl, cycloalkyl, alkoxycarbonylcycloalkyl, hydroxycycloalkyl, Ar2 or T—Ar2 where T is C(═O). 6. The compound of claim 5 where R1 is cyclohexyl, cyclohexanol-4-yl, cyclohexanon-4-yl, 2-propan-1-ol, 2-methoxy-1-methylethyl, 3-butyryl alkyl ester, 2-pyridinyl-2-ethyl, or an optionally substituted phenyl, naphthyl, pyridyl, quinolinyl, thienyl or indanyl. 7. The compound of claim 6 where R2 is an optionally substituted alkyl. 8. A compound selected from those listed in any of Tables 1-7. 9. A compound having the formula: wherein A is N or CH; PG is hydrogen or a nitrogen protecting group; R1 is H, T(n)—R, or T(n)—Ar2; R is an aliphatic or substituted aliphatic group; n is zero or one; T is C(═O), CO2, CONH, S(O)2, S(O)2NH, COCH2 or CH2; and each R2 is independently selected from hydrogen, —R, —CH2OR, —CH2OH, —CH═O, —CH2SR, —CH2S(O)2R, —CH2(C═O)R, —CH2CO2R, —CH2CO2H, —CH2CN, —CH2NHR, —CH2N(R)2, —CH═N—OR, —CH═NNHR, —CH═NN(R)2, —CH═NNHCOR, —CH═NNHCO2R, —CH═NNHSO2R, -aryl, -substituted aryl, —CH2 (aryl), —CH2(substituted aryl), —CH2NH2, —CH2NHCOR, —CH2NHCONHR, —CH2NHCON(R)2, —CH2NRCOR, —CH2NHCO2R, —CH2CONHR, —CH2CON(R)2, —CH2SO2NH2, —CH2(heterocyclyl), —CH2(substituted heterocyclyl), -(heterocyclyl), or -(substituted heterocyclyl). 10. A compound having the formula: wherein: X—Y is N—O or O—N providing an isoxazole or reverse isoxazole ring; A is N or CH; G is R, aryl or-substituted aryl; R is aliphatic or substituted aliphatic R2 is selected from hydrogen, —R, —CH2OR, —CH2OH, —CH═O, —CH2SR, —CH2S(O)2R, —CH2(C═O)R, —CH2CO2R, —CH2CO2H, —CH2CN, —CH2NHR, —CH2N(R)2, —CH═N—OR, —CH═NNHR, —CH═NN(R)2, —CH═NNHCOR, —CH═NNHCO2R, —CH═NNHSO2R, -aryl, -substituted aryl, —CH2(aryl), —CH2(substituted aryl), —CH2NH2, —CH2NHCOR, —CH2NHCONHR, —CH2NHCON(R)2, —CH2NRCOR, —CH2NHCO2R, —CH2CONHR, —CH2CON(R)2, —CH2SO2NH2, —CH2(heterocyclyl), —CH2(substituted heterocyclyl), -(heterocyclyl), or -(substituted heterocyclyl); and R1 is selected from halogen, NH2, SR, or SO2R; provided that R1 is other than Br or Cl when A is CH. 11. A pharmaceutical composition comprising an amount of a compound according any one of claims 1-8 effective to inhibit JNK, and a pharmaceutically acceptable carrier. 12. A method for treating a disease state or condition in mammals that is alleviated by treatment with a protein kinase inhibitor, comprising administering to a mammal in need of such a treatment a therapeutically effective amount of a compound of formula I: wherein: X—Y—Z is selected from one of the following: R1 is H, CONH2, T(n)—R, or T(n)—Ar2; R is an aliphatic or substituted aliphatic group; n is zero or one; T is C(═O), CO2, CONH, S(O)2, S(O)2NH, COCH2 or CH2; each R2 is independently selected from hydrogen, —R, —CH2OR, —CH2OH, —CH═O, —CH2SR, —CH2S(O)2R, —CH2(C═O)R, —CH2CO2R, —CH2CO2H, —CH2CN, —CH2NHR, —CH2N(R)2, —CH═N—OR, —CH═NNHR, —CH═NN(R)2, —CH═NNHCOR, —CH═NNHCO2R, —CH═NNHSO2R, -aryl, -substituted aryl, —CH2(aryl), —CH2(substituted aryl), —CH2NH2, —CH2NHCOR, —CH2NHCONHR, —CH2NHCON(R)2, —CH2NRCOR, —CH2NHCO2R, —CH2CONHR, —CH2CON(R)2, —CH2SO2NH2, —CH2(heterocyclyl), —CH2(substituted heterocyclyl), -(heterocyclyl), or -(substituted heterocyclyl); each R3 is independently selected from hydrogen, R, COR, CO2R or S(O)2R; G is R or Ar1; Ar1 is aryl, substituted aryl, aralkyl, substituted aralkyl, heterocyclyl, or substituted heterocyclyl, wherein Ar1 is optionally fused to a partially unsaturated or fully unsaturated five to seven membered ring containing zero to three heteroatoms; Q—NH is wherein the H of Q—NH is optionally replaced by R3; A is N or CR3; U is CR3, O, S, or NR3; Ar2 is aryl, substituted aryl, heterocyclyl or substituted heterocyclyl, wherein Ar2 is optionally fused to a partially unsaturated or fully unsaturated five to seven membered ring containing zero to three heteroatoms; wherein each substitutable carbon atom in Ar2, including the fused ring when present, is optionally and independently substituted by halo, R, OR, SR, OH, NO2, CN, NH2, NHR, N(R)2, NHCOR, NHCONHR, NHCON(R)2, NRCOR, NHCO2R, CO2R, CO2H, COR, CONHR, CON(R)2, S(O)2R, SONH2, S(O)R, SO2NHR, or NHS(O)2R, and wherein each saturated carbon in the fused ring is further optionally and independently substituted by ═O, ═S, ═NNHR, ═NNR2, ═N—OR, ═NNHCOR, ═NNHCO2R, ═NNHSO2R, or ═NR; and wherein each substitutable nitrogen atom in Ar2 is optionally substituted by R, COR, S(O)2R, or CO2R. 13. The method of claim 12 wherein the disease state is alleviated by treatment with an inhibitor of JNK. 14. The method of claim 12 wherein the disease is selected from inflammatory diseases, autoimmune diseases, destructive bone disorders, proliferative disorders, infectious diseases, neurodegenerative diseases, allergies, reperfusion/ischemia in stroke, heart attacks, angiogenic disorders, organ hypoxia, vascular hyperplasia, cardiac hypertrophy, thrombin-induced platelet aggregation or conditions associated with proinflammatory cytokines. 15. The method according to claim 12, wherein said method is used to treat or prevent an inflammatory disease selected from acute pancreatitis, chronic pancreatitis, asthma, allergies, or adult respiratory distress syndrome. 16. The method according to claim 12, wherein said method is used to treat or prevent an autoimmune disease selected from glomerulonephritis, rheumatoid arthritis, systemic lupus erythematosus, scleroderma, chronic thyroiditis, Graves' disease, autoimmune gastritis, diabetes, autoimmune hemolytic anemia, autoimmune neutropenia, thrombocytopenia, atopic dermatitis, chronic active hepatitis, myasthenia gravis, multiple sclerosis, inflammatory bowel disease, ulcerative colitis, Crohn's disease, psoriasis, or graft vs. host disease. 17. The method according to claim 12, wherein said method is used to treat or prevent a destructive bone disorders selected from osteoarthritis, osteoporosis or multiple myeloma-related bone disorder. 18. The method according to claim 12, wherein said method is used to treat or prevent a proliferative disease selected from acute myelogenous leukemia, chronic myelogenous leukemia, metastatic melanoma, Kaposi's sarcoma, or multiple myeloma. 19. The method according to claim 12, wherein said method is used to treat or prevent neurodegenerative disease selected from Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease, cerebral ischemia or neurodegenerative disease caused by traumatic injury, glutamate neurotbxicity or hypoxia. 20. The method according to claim 12, wherein said method is used to treat or prevent ischemia/reperfusion in stroke or myocardial ischemia, renal ischemia, heart attacks, organ hypoxia or thrombin-induced platelet aggregation. 21. The method according to claim 12, wherein said method is used to treat or prevent a condition associated with T-cell activation or pathologic immune responses. 22. The method according to claim 12, wherein said method is used to treat or prevent an angiogenic disorder selected from solid tumors, ocular neovasculization, or infantile haemangiomas. 23. The method of claim 12 wherein the disease state or condition is alleviated by treatment with an inhibitor of a Src-family kinase. 24. The method of claim 23 wherein the disease state or condition is hypercalcemia, restenosis, hypercalcemia, osteoporosis, osteoarthritis, symptomatic treatment of bone metastasis, rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis, psoriasis, lupus, graft vs. host disease, T-cell mediated hypersensitivity disease, Hashimoto's thyroiditis, Guillaiti-Barre syndrome, chronic obtructive pulmonary disorder, contact dermatitis, cancers Paget's disease, asthma, ischemic or reperfusion injury, allergic disease, atopic dermatitis, or allergic rhinitis. | This application claims the benefit of co-pending International Application PCT/US00/22445 filed Aug. 11, 2000 which claims priority from U.S. Provisional Application Ser. No. 60/148,795 filed Aug. 13, 1999; U.S. Provisional Application Ser. No. 60/166,922 filed Nov. 22, 1999 and U.S. Provisional Application Ser. No. 60/211,517 filed Jun. 14, 2000. TECHNICAL FIELD OF INVENTION The present invention relates to inhibitors of protein kinase, especially c-Jun N-terminal kinases (JNK), which are members of the mitogen-activated protein (MAP) kinase family. There are a number of different genes and isoforms which encode JNKs. Members of the JNK family regulate signal transduction in response to environmental stress and proinflammatory cytokines and have been implicated to have a role in mediating a number of different disorders. The invention also relates to methods for producing these inhibitors. The invention also provides pharmaceutical compositions comprising the inhibitors of the invention and methods of utilizing those compositions in the treatment and prevention of various disorders. BACKGROUND OF THE INVENTION Mammalian cells respond to extracellular stimuli by activating signaling cascades that are mediated by members of the mitogen-activated protein (MAP) kinase family, which include the extracellular signal regulated kinases (ERKs), the p38 MAP kinases and the c-Jun N-terminal kinases (JNKs). MAP kinases (MAPKs) are activated by a variety of signals including growth factors, cytokines, UV radiation, and stress-inducing agents. MAPKs are serine/threonine kinases and their activation occur by dual phosphorylation of threonine and tyrosine at the Thr-X-Tyr segment in the activation loop. MAPKs phosphorylate various substrates including transcription factors, which in turn regulate the expression of specific sets of genes and thus mediate a specific response to the stimulus. One particularly interesting kinase family are the c-Jun NH2-terminal protein kinases, also known as JNKs. Three distinct genes, JNK1, JNK2, JNK3 have been identified and at least ten different splicing isoforms of JNKs exist in mammalian cells [Gupta et al., EMBO J., 15:2760-70 (1996)]. Members of the JNK family are activated by proinflammatory cytokines, such as tumor necrosis factor-α (TNFα) and interleukin-1 β (IL-1β), as well as by environmental stress, including anisomycin, UV irradiation, hypoxia, and osmotic shock [Minden et al., Biochemica et Biophysica Acta, 1333:F85-F104 (1997)]. The down-stream substrates of JNKs include transcription factors c-Jun, ATF-2, Elk1, p53 and a cell death domain protein (DENN) [Zhang et al. Proc. Natl. Acad. Sci. USA, 95:2586-91 (1998)]. Each JNK isoform binds to these substrates with different affinities, suggesting a regulation of signaling pathways by substrate specificity of different JNKs in vivo (Gupta et al., supra) JNKs, along with other MAPKs, have been implicated in having a role in mediating cellular response to cancer, thrombin-induced platelet aggregation, immunodeficiency disorders, autoimmune diseases, cell death, allergies, osteoporosis and heart disease. The therapeutic targets related to activation of the JNK pathway include chronic myelogenous leukemia (CML), rheumatoid arthritis, asthma, osteoarthritis, ischemia, cancer and neurodegenerative diseases. Several reports have detailed the importance of JNK activation associated with liver disease or episodes of hepatic ischemia ([Nat. Genet. 21:326-9 (1999); FEBS Lett. 420:201-4 (1997); J. Clin. Invest. 102:1942-50 (1998); Hepatology 28:1022-30 (1998)]. Therefore, inhibitors of JNK may be useful to treat various hepatic disorders. A role for JNK in cardiovascular disease such as myocardial infarction or congestive heart failure has also been reported as it has been shown JNK mediates hypertrophic responses to various forms of cardiac stress [Circ. Res. 83:167-78 (1998); Circulation 97:1731-7 (1998); J. Biol. Chem. 272:28050-6 (1997); Circ. Res. 79:162-73 (1996); Circ. Res. 78:947-53 (1996); J. Clin. Invest. 97:508-14 (1996)]. It has been demonstrated that the JNK cascade also plays a role in T-cell activation, including activation of the IL-2 promoter. Thus, inhibitors of JNK may have therapeutic value in altering pathologic immune responses [J. Immunol. 162:3176-87 (1999); Eur. J. Immunol. 28:3867-77 (1998); J. Exp. Med. 186:941-53 (1997); Eur. J. Immunol. 26:989-94 (1996)]. A role for JNK activation in various cancers has also been established, suggesting the potential use of JNK inhibitors in cancer. For example, constitutively activated JNK is associated with HTLV-1 mediated tumorigenesis [Oncogene 13:135-42 (1996)]. JNK may play a role in Kaposi's sarcoma (KS) because it is thought that the proliferative effects of bFGF and OSM on KS cells are mediated by their activation of the JNK signaling pathway [J. Clin. Invest. 99:1798-804 (1997)]. Other proliferative effects of other cytokines implicated in KS proliferation, such as vascular endothelial growth factor (VEGF), IL-6 and TNFα, may also be mediated by JNK. In addition, regulation of the c-jun gene in p210 BCR-ABL transformed cells corresponds with activity of JNK, suggesting a role for JNK inhibitors in the treatment for chronic myelogenous leukemia (CML) [Blood 92:2450-60 (1998)]. JNK1 and JNK2 are widely expressed in a variety of tissues. In contrast, JNK3, is selectively expressed in the brain and to a lesser extent in the heart and testis [Gupta et al., supra; Mohit et al., Neuron 14:67-78 (1995); Martin et al., Brain Res. Mol. Brain Res. 35:47-57 (1996)]. JNK3 has been linked to neuronal apoptosis induced by kainic acid, indicating a role of JNK in the pathogenesis of glutamate neurotoxicity. In the adult human brain, JNK3 expression is localized to a subpopulation of pyramidal neurons in the CA1, CA4 and subiculum regions of the hippocampus and layers 3 and 5 of the neocortex [Mohit et al., supra]. The CA1 neurons of patients with acute hypoxia showed strong nuclear JNK3-immunoreactivity compared to minimal, diffuse cytoplasmic staining of the hippocampal neurons from brain tissues of normal patients [Zhang et al., supra]. Thus, JNK3 appears to be involved involved in hypoxic and ischemic damage of CA1 neurons in the hippocampus. In addition, JNK3 co-localizes immunochemically with neurons vulnerable in Alzheimer's disease [Mohit et al., supra]. Disruption of the JNK3 gene caused resistance of mice to the excitotoxic glutamate receptor agonist kainic acid, including the effects on seizure activity, AP-1 transcriptional activity and apoptosis of hippocampal neurons, indicating that the JNK3 signaling pathway is a critical component in the pathogenesis of glutamate neurotoxicity (Yang et al., Nature, 389:865-870 (1997)]. Based on these findings, JNK'signalling, especially that of JNK3, has been implicated in the areas of apoptosis-driven neurodegenerative diseases such as Alzheimer's Disease, Parkinson's Disease, ALS (Amyotrophic Lateral Sclerosis), epilepsy and seizures, Huntington's Disease, traumatic brain injuries, as well as ischemic and hemorrhaging stroke. There is a high unmet medical need to develop JNK specific inhibitors that are useful in treating the various conditions associated with JNK activation, especially considering the currently available, relatively inadequate treatment options for the majority of these conditions. Recently, we have described crystallizable complexes of JNK protein and adenosine monophosphate, including complexes comprising JNK3, in U.S. Provisional Application 60/084056, filed May 4, 1998. Such information hasbeen extremely useful in identifying and designing potential inhibitors of various members of the JNK family, which, in turn, have the described above therapeutic utility. Much work has been done to identify and develop drugs that inhibit MAPKs, such as p38 inhibitors. See, e.g., WO 98/27098 and WO 95/31451. However, to our knowledge, no MAPK inhibitors have been shown to be specifically selective for JNKs versus other related MAPKs. Accordingly, there is still a great need to develop potent inhibitors of JNKs, including JNK3 inhibitors, that are useful in treating various conditions associated with JNK activation. SUMMARY OF THE INVENTION It has now been found that compounds of this invention and pharmaceutical compositions thereof are effective as inhibitors of c-Jun N-terminal kinases (JNK). These compounds have the general formula I: where R1 is H, CONH2, T(n)—R, or T(n)—Ar2, n may be zero or one, and G, XYZ, and Q are as described below. Preferred compounds are those where the XYZ-containing ring is an isoxazole. Preferred G groups are optionally substituted phenyls and preferred Q are pyrimidine, pyridine or pyrazole rings. These compounds and pharmaceutical compositions thereof are useful for treating or preventing a variety of disorders, such as heart disease, immunodeficiency disorders, inflammatory diseases, allergic diseases, autoimmune diseases, destructive bone disorders such as osteoporosis, proliferative disorders, infectious diseases and viral diseases. The compositions are also useful in methods for preventing cell death and hyperplasia and therefore may be used to treat or prevent reperfusion/ischemia in stroke, heart attacks, and organ hypoxia. The compositions are also useful in methods for preventing thrombin-induced platelet aggregation. The compositions are especially useful for disorders such as chronic myelogenous leukemia (CML), rheumatoid arthritis, asthma, osteoarthritis, ischemia, cancer, liver disease including hepatic ischemia, heart disease such as myocardial infarction and congestive heart failure, pathologic immune conditions involving T cell activation and neurodegenerative disorders. DETAILED DESCRIPTION OF THE INVENTION This invention provides novel compounds, and pharmaceutically acceptable derivatives thereof, that are useful as JNK inhibitors. These compounds have the general formula I: wherein: X—Y—Z is selected from one of the following: R1 is H, CONH2, T(n)—R, or T(n)—Ar2; R is an aliphatic or substituted aliphatic group; n is zero or one; T is C(═O), CO2, CONH, S(O)2, S(O)2NH, COCH2 or CH2; each R2 is independently selected from hydrogen, —R, —CH2OR, —CH2OH, —CH═O, —CH2SR, —CH2S(O)2R, —CH2(C═O)R, —CH2CO2R, —CH2CO2H, —CH2CN, —CH2NHR, —CH2N(R)2, —CH═N—OR, —CH═NNHR, —CH═NN(R)2, —CH═NNHCOR, —CH═NNHCO2R, —CH═NNHSO2R, -aryl, -substituted aryl, —CH2(aryl), —CH2(substituted aryl), —CH2NH2, —CH2NHCOR, —CH2NHCONHR, —CH2NHCON (R)2, —CH2NRCOR, —CH2NHCO2R, —CH2CONHR, —CH2CON(R)2, —CH2SO2NH2, —CH2(heterocyclyl), —CH2(substituted heterocyclyl), -(heterocyclyl), or -(substituted heterocyclyl); each R3 is independently selected from hydrogen, R, COR, CO2R or S(O)2R; G is R or Ar1; Ar1 is aryl, substituted aryl, aralkyl, substituted aralkyl, heterocyclyl, or substituted heterocyclyl, wherein Ar1 is optionally fused to a partially unsaturated or fully unsaturated five to seven membered ring containing zero to three heteroatoms; Q—NH is wherein the H of Q—NH is optionally replaced by R3; A is N or CR3; U is CR3, O, S, or NR3; Ar2 is aryl, substituted aryl, heterocyclyl or substituted heterocyclyl, wherein Ar2 is optionally fused to a partially unsaturated or fully unsaturated five to seven membered ring containing zero to three heteroatoms; and wherein each substitutable carbon atom in Ar2, including the fused ring when present, is optionally and independently substituted by halo, R, OR, SR, OH, NO2, CN, NH2, NHR, N(R)2, NHCOR, NHCONHR, NHCON(R)2, NRCOR, NHCO2R, CO2R, CO2H, COR, CONHR, CON(R)2, S(O)2R, SONH2, S(O)R, SO2NHR, or NHS(O)2R, and wherein each saturated carbon in the fused ring is further optionally and independently substituted by ═O, ═S, ═NNHR, ═NNR2, ═N—OR, ═NNHCOR, ═NNHCO2R, ═NNHSO2R, or ═NR; wherein each substitutable nitrogen atom in Ar2 is optionally substituted by R, COR, S(O)2R, or CO2R. As used herein, the following definitions shall apply unless otherwise indicated. The term “aliphatic” as used herein means straight chained, branched or cyclic C1-C12 hydrocarbons, preferably one to six carbons, which are completely saturated or which contain one or moreunits of unsaturation. For example, suitable aliphatic groups include substituted or unsubstituted linear, branched or cyclic alkyl, alkenyl, alkynyl groups and hybrids thereof such as (cycloalkyl)alkyl, (cycloalkenyl)alkyl or (cycloalkyl)alkenyl. The term “alkyl” and “alkoxy” used alone or as part of a larger moiety refers to both straight and branched chains containing one to twelve carbon atoms. The terms “alkenyl” and “alkynyl” used alone or as part of a larger moiety shall include both straight and branched chains containing two to twelve carbon atoms. The terms “haloalkyl”, “haloalkenyl” and “haloalkoxy” means alkyl, alkenyl or alkoxy, as the case may be, substituted with one or more halogen atoms. The term “halogen” means F, Cl, Br, or I. The term “heteroatom” means N, O or S and shall include any oxidized form of nitrogen and sulfur, and the quaternized form of any basic nitrogen. The term “aryl”, used alone or as part of a larger moiety as in “aralkyl”, refers to aromatic ring groups having five to fourteen members, such as phenyl, benzyl, 1-naphthyl, 2-naphthyl, 1-anthracyl and 2-anthracyl, and heterocyclic aromatic groups or heteroaryl groups such as 2-furanyl, 3-furanyl, N-imidazolyl, 2-imidazolyl, 4-imidazolyl, 5-imidazolyl, 3-isoxazolyl, 4-isoxazolyl, 5-isoxazolyl, 2-oxadiazolyl, 5-oxadiazolyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, 2-pyrrolyl, 3-pyrrolyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrimidyl, 4-pyrimidyl, 5-pyrimidyl, 3-pyridazinyl, 3-pyridazinyl, 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, 5-tetrazolyl, 2-triazolyl, 5-triazolyl, 2-thienyl, or 3-thienyl. Aryl groups also include fused polycyclic aromatic ring systems in which a carbocyclic aromatic ring or heteroaryl ring is fused to one or more other rings. Examples include tetrahydronaphthyl, benzimidazolyl, benzothienyl, benzofuranyl, indolyl, quinolinyl, benzodiazepinyl, benzothiazolyl, benzooxazolyl, benzimidazolyl, isoquinolinyl, isoindolyl, acridinyl, benzoisoxazolyl, and the like. Also included within the scope of the term “aryl”, as it is used herein, is a group in which one or more carbocyclic aromatic rings and/or heteroaryl rings are fused to a cycloalkyl or non-aromatic heterocyclyl, for example, indanyl or tetrahydrobenzopyranyl. The term,“heterocyclic ring” or “heterocyclyl” refers to a non-aromatic ring which includes one or more heteroatoms such as nitrogen, oxygen or sulfur in the ring. The ring can be five, six, seven or eight-membered and/or fused to another ring, such as a cycloalkyl or aromatic ring. Examples include 3-1H-benzimidazol-2-one, 3-1-alkyl-benzimidazol-2-one, 2-tetrahydrofuranyl, 3-tetrahydrofuranyl, 2-tetrahydropyranyl, 3-tetrahydropyranyl, 4-tetrahydropyranyl, 2-tetrahydrothiophenyl, 3-tetrahydrothiophenyl, 2-morpholino, 3-morpholino, 4-morpholino, 2-thiomorpholino, 3-thiomorpholino, 4-thiomorpholino, 1-pyrrolidinyl, 2-pyrrolidinyl, 3-pyrrolidinyl, 1-piperazinyl, 2-piperazinyl, 1-piperidinyl, 2-piperidinyl, 3-piperidinyl, 4-piperidinyl, 4-thiazolidinyl, diazolonyl, N-substituted diazolonyl, 1-phthalimidinyl, benzoxane, benzotriazol-1-yl, benzopyrrolidine, benzopiperidine, benzoxolane, benzothiolane, and benzothiane. A compound of this invention may contain a ring that is fused to a partially saturated or fully unsaturated five to seven membered ring containing zero to three heteroatoms. Such a fused ring may be an aromatic or non-aromatic monocyclic ring, examples of which include the aryl and heterocyclic rings described above. An aryl group (carbocyclic and heterocyclic) or an aralkyl group, such as benzyl or phenethyl, may contain one or more substituents. Examples of suitable substituents on the unsaturated carbon atom of an aryl group include a halogen, —R, —OR, —OH, —SH, —SR, protected OH (such as acyloxy), phenyl (Ph), substituted Ph, —OPh, substituted —OPh, —NO2, —CN, —NH2, —NHR, —N(R)2, —NHCOR, —NHCONHR, —NHCON(R)2, —NRCOR, —NHCO2R, —CO2R, —CO2H, —COR, —CONHR, —CON(R)2, —S(O)2R, —SONH2, —S(O)R, —SO2NHR, or —NHS(O)2R, where R is an aliphatic group or a substituted aliphatic group. An aliphatic group or a non-aromatic heterocyclic ring may contain one or more substituents. Examples of suitable substituents on the saturated carbon of an aliphatic group or of a non-aromatic heterocyclic ring include those listed above for the unsaturated carbon, such as in an aromatic ring, as well as the following: ═O, ═S, ═NNHR, ═NNR2, ═N—OR, ═NNHCOR, ═NNHCO2R, ═NNHSO2R, or ═NR. A substitutable nitrogen on an aromatic or non-aromatic heterocyclic ring may be optionally substituted. Suitable substituents on the nitrogen include R, COR, S(O)2R, and CO2R, where R is an aliphatic group or a substituted aliphatic group. Compounds derived by making isosteric or bioisosteric replacements of carboxylic acid or ester moieties of compounds described herein are within the scope of this invention. Isosteres, which result from the exchange of an atom or group of atoms to create a new compound with similar biological properties to the parent carboxylic acid or ester, are known in the art. The bioisosteric replacement may be physicochemically or topologically based. An example of an isosteric replacement for a carboxylic acid is CONHSO2(alkyl) such as CONHSO2Me. It will be apparent to one skilled in the art that certain compounds of this invention may exist in tautomeric forms or hydrated forms, all such forms of the compounds being within the scope of the invention. Unless otherwise stated, structures depicted herein are also meant to include all stereochemical forms of the structure; i.e., the R and S configurations for each asymmetric center. Therefore, single stereochemical isomers as well as enantiomeric and diastereomeric mixtures of the present compounds are within the scope of the invention. Unless otherwise stated, structures depicted herein are also meant to include compounds which differ only in the presence of one or more isotopically enriched atoms. For example, compounds having the present structures except for the replacement of a hydrogen by a deuterium or tritium, or the replacement of a carbon by a 13C- or 14C-enriched carbon are within the scope of this invention. Such compounds are useful, for example, as analytical tools or probes in biological assays. One embodiment of this invention relates to compounds of formula I where the XYZ-containing ring is an isoxazole, as shown by the general formula IA below: where R2 is preferably alkyl, such as methyl, or CH2(heterocyclyl), such as CH2(N-morpholinyl); G is preferably Ar1; and R1 is preferably T(n)—Ar2 or T(n)—R, wherein n is most preferably zero. Most preferred are those compounds where G, R1, and R2 are as just described, and Q—NH is an aminopyridine or aminopyrimidine where the NH is at the 2 position of the ring: or Q—NH is an amino pyrazole:. Table 1 below shows representative examples of IA compounds where Q is a pyrimidine, pyridine or pyrazole and R1 is Ar2, represented by formula IIA. TABLE 1 Examples of Compounds of Formula IIA No. G Q R2 R3 R4 R5 R6 R7 IIA-1 Ph Q1 Me H H H H H IIA-2 Ph Q1 Me H H OMe H H IIA-3 Ph Q1 Me H OMe OMe H H IIA-4 Ph Q1 Me Me H H H H IIA-5 Ph Q1 Me Me H CONH2 H H IIA-6 Ph Q1 Me Me H CN H H IIA-7 Ph Q1 Me H CN H H H IIA-8 Ph Q1 Me Me F H H H IIA-9 Ph Q1 Me Me H F H H IIA-10 Ph Q1 Me CF3 H H H H IIA-11 4-F—Ph Q1 Me H H H H H IIA-12 2,3-(MeO)2—Ph Q1 Me H H H H H IIA-13 2,4-(MeO)2—Ph Q1 Me H H H H H IIA-14 2-Cl—Ph Q1 Me H H H H H IIA-15 3,4-Cl2—Ph Q1 Me H H H H H IIA-16 Ph Q2 Et H CN H H H IIA-17 Ph Q2 Et H CO2H H H H IIA-18 Ph Q2 Me H F H H H IIA-19 Ph Q2 Me H H F H H IIA-20 Ph Q2 Me H H COMe H H IIA-21 Ph Q2 Me H H COPh H H IIA-22 Et Q1 Me H H H H H IIA-23 PhCH2OCH2— Q1 Me H H H H H IIA-24 Ph Q2 Me H H CONH2 H H IIA-25 3-F—Ph Q1 Me H CN H H H IIA-26 3-F—Ph Q1 Me H H CN H H IIA-27 3-F—Ph Q1 Me H F H H H IIA-28 3-F—Ph Q1 Me H H F H H IIA-29 3-F—Ph Q1 Me H Me CN H H IIA-30 3-F—Ph Q1 Me H F CN H H IIA-31 3-F—Ph Q1 Me H H SMe H H IIA-32 Ph Q1 Me H F CN H H IIA-33 Ph Q1 Me H F H H H IIA-34 Ph Q1 Me H H CN H H IIA-35 Ph Q1 Me H H COMe H H IIA-36 Ph Q1 Me H CH═CH H H H IIA-37 Ph Q1 Me H SMe H H H IIA-38 Ph Q1 Me H Me CN H H IIA-39 Ph Q1 Me H COMe H H H IIA-40 Ph Q2 Et H H H H H IIA-41 Ph Q1 Me OMe H H H H IIA-42 Ph Q1 Me H H F H H IIA-43 Ph Q2 Me H CO2H H H H IIA-44 Ph Q1 Me H H Ph H H IIA-45 Ph Q1 Me H Me H Me H IIA-46 Ph Q1 Me H H SMe H H IIA-47 Ph Q2 Me H H OMe H H IIA-48 Ph Q2 Me H OMe H H H Ph Q1 Me OMe H H CN H IIA-50 Ph Q2 Me H CO2Me H H H IIA-51 Ph Q1 Me F H H CN H IIA-52 Ph Q2 Me H H H H H IIA-53 Ph Q2 Me H H CO2H H H IIA-54 Ph Q1 Me Me H CN H H IIA-55 2-F—Ph Q1 Me H H H H H IIA-56 Ph Q1 Me F H F H H IIA-57 Ph Q1 Me Me H CONH2 H H IIA-58 Ph Q1 Me Me Q1 H H H IIA-59 Ph Q1 Me F H H H H IIA-60 2,6-F2—Ph Q1 Me H H H H H IIA-61 Ph Q1 Me Me H OMe H H IIA-62 Ph Q1 Me OMe H H H H IIA-63 Ph Q1 Me H H SO2Me H H IIA-64 Ph Q2 Me H H CO2Me H H IIA-65 Ph Q1 Me NO2 H H H H IIA-66 3-F—Ph Q1 Me H H H H H IIA-67 Ph Q2 Me H CN H H H IIA-68 Ph Q2 Me H H CN H H IIA-69 Ph Q1 Me CH:CH H H H H IIA-70 Ph Q1 Me Me F H H H IIA-71 Ph Q1 Me Cl H H OMe H IIA-72 Ph Q1 Me H Me OMe H H IIA-73 Ph Q1 Me OMe H H OMe H IIA-74 2,5-F2—Ph Q1 Me H H H H H IlA-75 2-Cl-6-F—Ph Q1 Me H H H H H IIA-76 2-Cl—Ph Q1 Me H H H H H IIA-77 3,4-Cl2—Ph Q1 Me H H H H H IIA-78 Ph Q1 Me Me H F H H IIA-79 2-Br—Ph Q1 Me H H H H H IIA-80 2,3-F2—Ph Q1 Me H H H H H IIA-81 Ph Q1 Me SMe H H H H IIA-82 3-CF3—Ph Q1 Me H H H H H IIA-83 3,5-F2—Ph Q1 Me H H H H H IIA-84 2,6-Cl2—Ph Q1 Me H H H H H IIA-85 2,3-(MeO)2—Ph Q1 Me H H H H H IIA-86 Me Q1 Me H H H H H IIA-87 cyclopropyl Q1 Me H H H H H IIA-88 cyclohexyl Q1 Me H H H H H IIA-89 2,4-(MeO)2—Ph Q1 Me H H H H H IIA-90 t-butyl Q1 Me H H H H H IIA-91 2,6-F2—Ph Q1 Me H H COMe H H IIA-92 2,6-F2—Ph Q1 Me H CN H H H IIA-93 2,6-F2—Ph Q1 Me H H CN H H IIA-94 2,6-F2—Ph Q1 Me H F H H H IIA-95 2,6-F2—Ph Q1 Me H H F H H IIA-96 2,6-F2—Ph Q1 Me H CN F H H IIA-97 2,6-F2—Ph Q1 Me H H SMe H H IIA-98 Ph Q2 Me H H NMe2 H H IIA-99 Ph Q2 Me H NO2 H H H IIA-100 Ph Q2 Me H NHAc H H H IIA-101 Ph Q2 Me H NH2 H H H IIA-102 Ph Q1 Me H Me H H H IIA-103 Ph Q1 Me H H Me H H IIA-104 2-Me—Ph Q1 Me H H H H H IIA-105 2-Me—Ph Q1 Me H F CN H H IIA-106 2-Me—Ph Q1 Me H F H H H IIA-107 2-Me—Ph Q1 Me H H CN H H IIA-108 2-Me—Ph Q1 Me H Me H H H IIA-109 2-Me—Ph Q1 Me H CN H H H IIA-110 2-CF3—Ph Q1 Me H F CN H H IIA-111 2-CF3—Ph Q1 Me H CN H H H IIA-112 2-CF3—Ph Q1 Me H H H H H IIA-113 3,4-(OCH2O)— Q1 Me H F CN H H Ph IIA-114 3,4-(OCH2O)— Q1 Me H CN H H H Ph IIA-115 3,4-(OCH2O)— Q1 Me H H H H H Ph IIA-116 Q1 Me IIA-117 3-OBn—Ph Q1 Me H F CN H H IIA-118 3-OBn—Ph Q1 Me H CN H H H IIA-119 3-OBn—Ph Q1 Me H H H H H IIA-120 3-NO2—Ph Q1 Me H F CN H H IIA-121 3-NO2—Ph Q1 Me bis-N,N′-4-cyanophenyl IIA-122 3-NO2—Ph Q1 Me H CN H H H IIA-123 3-NO2—Ph Q1 Me H H H H H IIA-124 3-CN—Ph Q1 Me H F CN H H IIA-125 3-CN—Ph Q1 Me H H CN H H IIA-126 3-CN—Ph Q1 Me H CN H H H IIA-127 3-CN—Ph Q1 Me H H H H H IIA-128 3-NO2—Ph Q1 Me H H CO2Et H H IIA-129 3-CN—Ph Q1 Me H CO2Me H H H IIA-130 Ph Q1 Me H CO2Et H H H IIA-131 Ph Q1 Me N H NO2 H H IIA-132 Ph Q2 Me IIA-133 Ph Q2 Me IIA-134 Ph Q2 Me H CH2OH H H H IIA-135 Ph Q2 Me IIA-136 Ph Q3 Me H CN H H H IIA-137 Ph Q3 Me H H CN H H IIA-138 Ph Q3 Me H COMe H H H For compounds of Formula IIA where R1 is phenyl, preferred phenyl substituents are selected from hydrogen and one or more halo, aliphatic, substituted aliphatic (preferably haloalkyl), alkoxy, CN, CO2H, CO2(alkyl), S(alkyl), CONH2, CO(alkyl), SO2(alkyl), CO(phenyl), or NO2. Preferred G groups are phenyl rings optionally substituted with one or more groups independently selected from alkyl, alkoxy or halogen. Examples of compounds of Formula IIA where R1 is other than phenyl are shown below in Table 2. TABLE 2 Examples of Compounds of Formula IIA (R1 is other than phenyl) No. G A R1 IIAA-1 Ph CH IIAA-2 Ph CH IIAA-3 Ph N IIAA-4 Ph N IIAA-5 Ph N IIAA-6 Ph N IIAA-7 Ph N IIAA-8 Ph N IIAA-9 3-F—Ph N IIAA-10 Ph N IIAA-11 Ph N IIAA-12 Ph N IIAA-13 Ph N IIAA-14 2,6-F2—Ph N IIAA-15 Ph N IIAA-16 Ph N IIAA-17 Ph N IIAA-18 Ph N IIAA-19 2-Me—Ph N IIAA-20 2-Me—Ph N IIAA-21 N IIAA-22 3-NO2—Ph N IIAA-23 3-CN—Ph N IIAA-24 Ph N IIAA-25 Ph N IIAA-26 Ph N IIAA-27 Ph N IIAA-28 Ph N IIAA-29 Ph N IIAA-30 Ph N IIAA-31 Ph N IIAA-32 Ph N IIAA-33 Ph N IIAA-34 Ph N IIAA-35 Ph N IIAA-36 Ph N IIAA-37 Ph N IIAA-38 Ph N IIAA-39 Ph CH IIAA-40 Ph CH Preferred IIA compounds are those where Ar1 is an unsubstituted phenyl or a phenyl substituted with one or more halo, alkyl or alkoxy. More preferred IIA compounds are those where Ar1 is as just described, and Ar2 is a naphthyl or phenyl optionally substituted with one or more halo, alkyl, alkoxy, haloalkyl, carboxyl, alkoxycarbonyl, cyano, or CONH2, or an indanone (as in compound IIAA-11). Also preferred are IIA compounds where R1 is an optionally substituted alkyl or optionally substituted cycloalkyl, more preferably alkoxyalkyl, alkoxycarbonylalkyl, hydroxyalkyl, pyridinylalkyl, alkoxycycloalkyl, alkoxycarbonylcycloalkyl, or hydroxycycloalkyl. Examples of these preferred compounds include IIAA-24, IIAA-33 through IIAA-36, IIAA-38 and IIAA-40. One embodiment of this invention relates to compounds of formula IA where Q is a pyrimidine ring and R1 is T—Ar2 where T is selected from CO, CO2, CONH, S(O)2, S(O)2NH, COCH2 and CH2. When R1 is T—Ar2, preferred compounds are those where T is C(═O), represented by formula IIIA. Table 3 below shows representative examples of IIIA compounds. TABLE 3 Examples of IIIA Compounds Ar2 No. Ar1 Q R2 R3 R4 R5 R6 IIIA-1 phenyl Q1 H H H H H IIIA-2 phenyl Q1 Br H H H H IIIA-3 phenyl Q1 F H H H H IIIA-4 phenyl Q1 Cl H H H H IIIA-5 phenyl Q1 CH3 H H H H IIIA-6 phenyl Q1 H CH3 H H H IIIA-7 phenyl Q1 H H OCH3 H H IIIA-8 phenyl Q1 H OCH3 OCH3 H H IIIA-9 phenyl Q1 OCH3 H OCH3 H H IIIA-10 phenyl Q1 OCH3 H H H OCH3 IIIA-11 phenyl Q1 H H CN H H IIIA-12 5-fluorophenyl Q1 H H OCH3 H H IIIA-13 phenyl Q1 H OCH3 OCH3 OCH3 H IIIA-14 phenyl Q1 H H F H H IIIA-15 phenyl Q1 Ar2 is 2-thienyl IIIA-16 phenyl Q1 Ar2 is 1-oxo-indan-5-yl IIIA-17 phenyl Q1 Ar2 is 4-pyridyl IIIA-18 2-CH3-phenyl Q1 H OCH3 OCH3 OCH3 H IIIA-19 2-CH3-phenyl Q1 H OCH3 H H H IIIA-20 2-CH3-phenyl Q1 H H OCH3 H H IIIA-21 2-CH3-phenyl Q1 H OCH3 H OCH3 H IIIA-22 2-CF3-phenyl Q1 H OCH3 OCH3 OCH3 H IIIA-23 2-CF3-phenyl Q1 H OCH3 H H H IIIA-24 2-CF3-phenyl Q1 H H OCH3 H H IIIA-25 2-CF3-phenyl Q1 H OCH3 H OCH3 H IIIA-26 benzo[3,5]dioxole Q1 H OCH3 OCH3 OCH3 H IIIA-27 benzo[3,5]dioxole Q1 H OCH3 H H H IIIA-28 benzo[3,5]dioxole Q1 H H OCH3 H H IIIA-29 benzo[3,5]dioxole Q1 H OCH3 H OCH3 H IIIA-30 3-benzyloxy-phenyl Q1 H OCH3 OCH3 OCH3 H IIIA-31 3-benzyloxy-phenyl Q1 H OCH3 H H H IIIA-32 3-benzyloxy-phenyl Q1 H H OCH3 H H IIIA-33 3-benzyloxy-phenyl Q1 H OCH3 H OCH3 H IIIA-34 3-nitrophenyl Q1 H OCH3 OCH3 OCH3 H IIIA-35 3-nitrophenyl Q1 H OCH3 H H H IIIA-36 3-nitrophenyl Q1 H H OCH3 H H IIIA-37 3-nitrophenyl Q1 H OCH3 H OCH3 H IIIA-38 3-cyanophenyl Q1 H OCH3 OCH3 OCH3 H IIIA-39 3-cyanophenyl Q1 H OCH3 H H H lIIA-40 3-cyanophenyl Q1 H H OCH3 H H IIIA-41 3-cyanophenyl Q1 H OCH3 H OCH3 H IIIA-42 phenyl Q1 H OCH3 H OCH3 H IIIA-43 phenyl Q1 H CN H H H IIIA-44 phenyl Q1 H H CO2Me H H IIIA-45 3-fluorophenyl Q1 H Cl H H H IIIA-46 3-fluorophenyl Q1 H OCH3 H H H IIIA-47 3-fluorophenyl Q1 H OCH3 H OCH3 H IIIA-48 3-fluorophenyl Q1 H Me H H H IIIA-49 3-fluorophenyl Q1 H H F H H IIIA-50 3-fluorophenyl Q1 H H Me H H IIIA-51 3-fluorophenyl Q1 H CN H H H IIIA-52 3-fluorophenyl Q1 H CH3 OCH3 OCH3 H IIIA-53 3-fluorophenyl Q1 Ar2 is 2-naphthyl IIIA-54 2-fluorophenyl Q1 H Cl H H H IIIA-55 2-fluorophenyl Q1 H OCH3 H H H IIIA-56 2-fluorophenyl Q1 H OCH3 H OCH3 H IIIA-57 2-fluorophenyl Q1 H Me H H H IIIA-58 2-fluorophenyl Q1 H H OCH3 H H IIIA-59 2-fluorophenyl Q1 H H F H H IIIA-60 2-fluorophenyl Q1 H H Me H H IIIA-61 2-fluorophenyl Q1 H CN H H H IIIA-62 2-fluorophenyl Q1 H OCH3 OCH3 OCH3 H IIIA-63 2-fluorophenyl Q1 Ar2 is 2-naphthyl IIIA-64 2,6-F2-phenyl Q1 H Cl H H H IIIA-65 2,6-F2-phenyl Q1 H OCH3 H H H IIIA-66 2,6-F2-phenyl Q1 H OCH3 H OCH3 H IIIA-67 2,6-F2-phenyl Q1 H Me H H H IIIA-68 2,6-F2-phenyl Q1 H H OCH3 H H IIIA-69 2,6-F2-phenyl Q1 H H F H H IIIA-70 2,6-F2-phenyl Q1 H H Me H H IIIA-71 2,6-F2-phenyl Q1 H CN H H H IIIA-72 2,6-F2-phenyl Q1 H OCH3 OCH3 OCH3 H IIIA-73 2,6-F2-phenyl Q1 Ar2 is 2-naphthyl IIIA-74 phenyl Q1 H NO2 H H H IIIA-75 phenyl Q1 H NHAc H H H IIIA-76 phenyl Q1 H COMe H H H IIIA-77 phenyl Q2 H COMe H H H IIIA-78 phenyl Q2 H CN H H H IIIA-79 phenyl Q3 H H H H H IIIA-80 phenyl Q3 H OCH3 H H H IIIA-81 phenyl Q3 H H OCH3 H H IIIA-82 phenyl Q3 H CN H H H IIIA-83 phenyl Q3 H OCH3 H OCH3 H IIIA-84 phenyl Q3 H H F H H IIIA-85 phenyl Q3 H COMe H H H IIIA-86 phenyl Q3 H H COMe H H IIIA-87 phenyl Q3 OCH3 H H H H IIIA-88 phenyl Q3 2-thienyl IIIA-89 phenyl Q3 2-furanyl IIIA-90 3-OMe-phenyl Q3 H OCH3 H H H IIIA-91 Cyclohexyl Q3 H OCH3 H H H IIIA-92 4-Cl-phenyl Q3 H OCH3 H H H IIIA-93 3-Cl-phenyl Q3 H OCH3 H H H IIIA-94 4-F-phenyl Q3 H OCH3 H H H IIIA-95 3-F-phenyl Q3 H OCH3 H H H IIIA-96 4-pyridyl Q3 H OCH3 H H H IIIA-97 3-pyridyl Q3 H OCH3 H H H Preferred IIIA compounds are those compounds where Ar1 is an unsubstituted phenyl or a phenyl substituted with one or more substituents independently selected from halogen. More preferred IIIA compounds are those where Ar1 is just described, and Ar2 is a thienyl, an unsubstituted phenyl or a phenyl substituted with one or more substituents independently selected from halogen, alkyl, alkoxy, CO2H or CO2R. Examples of other compounds where R1 is T—Ar1 are shown below where A is N or CH, and T is one of the following: CH2 (exemplified by IVA-1), S(O)2 (VA-1), CONH (VIA-1), COCH2 (VIIA-1), CO, (VIIIA-1), and S(O)2NH (IXA-1). In other examples of these embodiments the phenyl rings may be optionally substituted as described above. Another embodiment of this invention relates to compounds of formula IA where R1 is T—R, R is a C3-C6 cycloalkyl ring or a C1-C6 straight chain or branched alkyl or alkenyl group optionally substituted by halogen and T is as described above. When R1 is T—R, preferred compounds are those where T is C(═O) as represented by formula XA. Table 4 below shows representative examples of XA compounds. TABLE 4 Examples of XA Compounds (R2 is CH3) No. Ar1 R XA-1 phenyl CH3 XA-2 4-F-phenyl CH3 XA-3 phenyl Cyclopentyl XA-4 phenyl isobutyl XA-5 phenyl propyl Preferred R2 groups of formula I include —CH2OR, —CH2OH, —CH2(heterocyclyl), —CH2 (substituted heterocyclyl), —CH2N(R)2, and an R group such as methyl. Representative examples of compounds wherein R2 is other than methyl (formula IXA) are shown in Table 5 below. TABLE 5 Examples of Compound IXA No. Ar1 A R1 R2 XIA-1 phenyl CH phenyl CH2(morpholin-4-yl) XIA-2 phenyl CH phenyl CH2N(CH3)2 XIA-3 phenyl CH phenyl CH2NEt2 XIA-4 phenyl CH phenyl CH2N(CH3)CH2Ph XIA-5 phenyl CH phenyl CH2(1-t- butoxycarbonylpiperazin-4-yl) XIA-6 phenyl CH benzyl CH2(morpholin-4-yl) XIA-7 phenyl CH cyclohexyl CH2(morpholin-4-yl) XIA-8 phenyl CH 4-[1,2-(OMe)2-phenyl] CH2(morpholin-4-yl) XIA-9 phenyl CH 4-cyclohexanol OH2(morpholin-4-yl) XIA-10 phenyl CH phenyl CH2N(CH3)CH2CH2N(CH3)2 XIA-11 phenyl CH phenyl CH2N(CH3)CH2CO2CH3 XIA-12 phenyl CH phenyl CH2(piperazin-1-yl) XIA-13 phenyl N 2-thienoyl CH2Br XIA-14 phenyl N 2-thienoyl CH2(morpholin-4-yl) XIA-15 4-F-phenyl CH cyclohexyl CH2O(tetrahydrofuran-3-yl) XIA-16 4-F-phenyl CH 3-cyanophenyl CH2O(tetrahydrofuran-3-yl) XIA-17 4-F-phenyl CH 2-(2-pyridinyl)ethyl CH2O(tetrahydrofuran-3-yl) XIA-18 4-F-phenyl CH 1-benzyl-piperidin-4- CH2O(tetrahydrofuran-3-yl) yl XIA-19 4-F-phenyl CH 4-cyclohexanol CH2OCH2CH2OCH3 XIA-20 4-F-phenyl CH cyclohexyl CH2OCH2CH2OCH3 XIA-21 4-F-phenyl CH 2-(2-pyridinyl)ethyl CH2OCH2CH2OCH3 XIA-22 4-F-phenyl CH 1 -benzyl-piperidin-4- CH2OCH2CH2OCH3 yl XIA-23 4-F-phenyl CH 4-cyclohexanol CH2(morpholin-4-yl) XIA-24 4-F-phenyl CH cyclohexyl CH2(morpholin-4-yl) XIA-25 4-F-phenyl CH 3-cyanophenyl CH2(morpholin-4-yl) XIA-26 4-F-phenyl CH 2-(2-pyridinyl)ethyl CH2(morphofin-4-yl) XIA-27 4-F-phenyl CH 1-benzyl-piperidin-4- CH2(morpholin-4-yl) yl XIA-28 4-F-phenyl CH 4-cyclohexanol CH2OCH3 XIA-29 4-F-phenyl CH cyclohexyl CH2OCH3 XIA-30 4-F-phenyl CH 3-cyanophenyl CH2OCH3 XIA-31 4-F-phenyl CH 2-(2-pyridinyl)ethyl CH2OCH3 XIA-32 4-F-phenyl CH 1-benzyl-piperidin-4- CH2OCH3 yl XIA-33 4-F-phenyl CH 4-cyclohexanol CH2OCH3 XIA-34 4-F-phenyl CH cyclohexyl CH2OCH3 XIA-35 4-F-phenyl CH 3-cyanophenyl CH2OCH3 XIA-36 4-F-phenyl CH 2-(2-pyridinyl)ethyl CH2OCH3 XIA-37 4-F-phenyl CH 4-cyclohexanol CH2O(tetrahydrofuran-3-yl) XIA-38 4-F-phenyl CH cyclohexyl CH2O(tetrahydrofuran-3-yl) XIA-39 phenyl N 2-thienoyl CH2(pipendin-1-yl) XIA-40 phenyl N 2-thienoyl CH2(piperazin-1-yl) XIA-41 4-F-phenyl CH 4-methoxybenzyl CH2OCH3 XIA-42 4-F-phenyl N 4-cyclohexanol CH2(morpholin-4-yl) XIA-43 4-F-phenyl N cyclohexyl CH2OCH2CH3 XIA-44 4-F-phenyl N cyclohexyl CH2OCH2(phenyl) XIA-45 4-F-phenyl N cyclohexyl CH2OH XIA-46 4-F-phenyl N CH2CH2(pyridin-2-yl) CH2OH XIA-47 4-F-phenyl N cyclohexyl CH2OCH3 XIA-48 4-F-phenyl N cyclohexyl CH2OCH2CH3 XIA-49 4-F-phenyl N cyclohexyl CH2OCH2CH2OCH3 XIA-50 4-F-phenyl N cyclohexyl CH2O(tetrahydrofuran-3-yl) XIA-51 4-F-phenyl N cyclohexyl XIA-52 4-F-phenyl N cyclohexyl CH2OCH2(phenyl) XIA-53 4-F-phenyl N CH2CH2(pyridin-2-yl) CH2OCH2(phenyl) The XYZ-containing ring of formula I may be an isoxazole ring as shown above or it may an isomeric isoxazole or “reverse” isoxazole (IB). In this embodiment Q is preferably a pyrimidine or pyridine ring where A is N or CH, or Q is a pyrazole ring, and R2 is aliphatic or substituted aliphatic. Examples of IB compounds are shown in Table 6 below. TABLE 6 In another embodiment of this invention, the XYZ-containing ring is a pyrazole ring of formula IC: For compounds of formula IC, G is preferably an optionally substituted aryl. Specific examples of IC compounds are shown in Table 7 below. TABLE 7 Examples of IC Compounds No. G Q R1 R2 IC-1 4-F-phenyl Q2 Phenyl H IC-2 4-F-phenyl Q2 Cyclohexyl H IC-3 4-F-phenyl Q2 Isoquinolin-4-yl H IC-4 4-F-phenyl Q2 6-MeO-naphthalen-2-yl H IC-5 4-F-phenyl Q2 4-cyclohexanol H IC-6 4-F-phenyl Q1 Phenyl H IC-7 4-F-phenyl Q1 Cyclohexyl H IC-8 4-F-phenyl Q1 4-cyclohexanol H IC-9 4-F-phenyl Q2 Cyclohexyl CH3 IC-10 4-F-phenyl Q2 Cyclohexyl IC-11 Phenyl Q2 Cyclohexyl Other embodiments of this invention relate to compounds where the XYZ-containing ring is a furan (ID) or a triazole (IE). These embodiments are exemplified below where R1 is phenyl, R2′ is hydrogen, and A is N or CH. For compounds of formula IB-IE, the phenyl rings of Ar1 and Ar2 may be optionally substituted as shown above for the isoxazoles of formula IA. The compounds of this invention may be prepared in general by methods known to those skilled in the art for analogous compounds, as illustrated by the general schemes below and by the preparative examples that follow. Scheme I above shows a route for making isoxazoles where Q is a pyrimidine ring. The starting benzaldehyde oxime 1 may be converted to the α-chlorobenzaldehyde oxime 2 using N-chlorosuccinimide and a catalytic amount of pyridine. Condensation of 2 with 2,4-pentanedione provides the isoxazole 3 which may be treated with dimethylformamide dimethylacetal to obtain the enamine 4. After an aqueous work-up and without purification, 4 may be cyclized with guanidine hydrochloride to the aminopyrimidine 5. Compounds of formula IIA may be obtained from 5 according to step (e) using the appropriate arylbromide in the presence of tris(dibenylideneacetone) dipalladium. Alternatively, 5 may be treated with the appropriate acid chloride in a pyridine/benzene solvent according to step (f) to give compounds of formula IVA. If the acid chloride is a Ar2COCl, compounds of formula IIIA may be obtained in a similar manner. Scheme II above shows a route for making isoxazoles of this invention where Q is a pyrimidine ring and R2 is modified by various groups. Scheme III above shows a synthetic route for making isoxazoles of this invention where Q is a pyridine and R2 is modified by various groups. In Scheme II and Scheme III, the isoxazole ring is first constructed and then the 2-position of the pyrimidine or pyridine ring is elaborated with the appropriate NHR1 substitution. It will be apparent to one skilled in the art that position 2 of the pyrimidine or pyridine ring can be elaborated with the appropriate NHR1 substitution before the isoxazole ring is constructed. Accordingly, isoxazoles of this invention may be obtained by performing step (b) using an appropriate intermediate having the formula XII: where A is N or CH; R1 and R2 are as described above; and PG is hydrogen or a nitrogen protecting group. Nitrogen protecting groups are well-known and include groups such as benzyl or CO2R, where R is preferably alkyl, allyl or benzyl. Scheme IV above shows a synthetic route king reverse isoxazoles of this invention Q is a pyrimidine ring. Scheme V above shows a synthetic route for making reverse isoxazoles of this invention where Q is a pyridine ring. Scheme VI above shows a general route for preparing compounds of this invention wherein Q is a pyrazole ring. Scheme VII above shows a general route for preparing compounds of this invention wherein the XYZ ring is a pyrazole ring. Certain of the intermediates that are useful for making the kinase inhibitors of this invention are believed to be novel. Accordingly, one embodiment of this invention relates to compounds XII above and compounds represented by formula XIII: wherein: X—Y is N—O or O—N providing an isoxazole or reverse isoxazole ring; A is N or CH; G is R, aryl or substituted aryl; R is aliphatic or substituted aliphatic R2 is selected from hydrogen, —R, —CH2OR, —CH2OH, —CH═O, —CH2SR, —CH2S(O)2R, —CH2(C═O)R, —CH2CO2R, —CH2CO2H, —CH2CN, —CH2NHR, —CH2N(R)2, —CH═N—OR, —CH═NNHR, —CH═NN(R)2, —CH═NNHCOR, —CH═NNHCO2R, —CH═NNHSO2R, -aryl, -substituted aryl, —CH2(aryl), —CH2(substituted aryl), —CH2NH2, —CH2NHCOR, —CH2NHCONHR, —CH2NHCON(R)2, —CH2NRCOR, —CH2NHCO2R, —CH2CONHR, —CH2CON(R)2, —CH2SO2NH2, —CH2(heterocyclyl), —CH2(substituted heterocyclyl), -(heterocyclyl), or -(substituted heterocyclyl); and R1 is selected from halogen, NH2, SR, or SO2R. The activity of the JNK inhibitors of this invention may be assayed in vitro, in vivo or in a cell line. In vitro assays include assays that determine inhibition of either the kinase activity or ATPase activity of activated JNK. For example, see the testing examples described below. Alternate in vitro assays quantitate the ability of the inhibitor to bind to JNK and may be measured either by radiolabelling the inhibitor prior to binding, isolating the inhibitor/JNK complex and determining the amount of radiolabel bound, or by running a competition experiment where new inhibitors are incubated with JNK bound to known radioligands. One may use any type or isoform of JNK, depending upon which JNK type or isoform is to be inhibited. The JNK inhibitors or pharmaceutical salts thereof may be formulated into pharmaceutical compositions for administration to animals or humans. These pharmaceutical compositions, which comprise an amount of JNK inhibitor effective to treat or prevent a JNK-mediated condition and a pharmaceutically acceptable carrier, are another embodiment of the present invention. The term “JNK-mediated condition”, as used herein means any disease or other deleterious condition in which JNK is known to play a role. Such conditions include, without limitation, inflammatory diseases, autoimmune diseases, destructive bone disorders, proliferative disorders, cancer, infectious diseases, neurodegenerative diseases, allergies, reperfusion/ischemia in stroke, heart attacks, angiogenic disorders, organ hypoxia, vascular hyperplasia, cardiac hypertrophy, thrombin-induced platelet aggregation, and conditions associated with prostaglandin endoperoxidase synthase-2. Inflammatory diseases which may be treated or prevented by the compounds of this invention include, but are not limited to, acute pancreatitis, chronic pancreatitis, asthma, allergies, and adult respiratory distress syndrome. Autoimmune diseases which may be treated or prevented by the compounds of this invention include, but are not limited to, glomerulonephritis, rheumatoid arthritis, systemic lupus erythematosus, scleroderma, chronic thyroiditis, Graves' disease, autoimmune gastritis, diabetes, autoimmune hemolytic anemia, autoimmune neutropenia, thrombocytopenia, atopic dermatitis, chronic active hepatitis, myasthenia gravis, multiple sclerosis, inflammatory bowel disease, ulcerative colitis, Crohn's disease, psoriasis, or graft vs. host disease. Destructive bone disorders which may be treated or prevented by the compounds of this invention include, but are not limited to, osteoporosis, osteoarthritis and multiple myeloma-related bone disorder. Proliferative diseases which may be treated or prevented by the compounds of this invention include, but are not limited to, acute myelogenous leukemia, chronic myelogenous leukemia, metastatic melanoma, Kaposi's sarcoma, multiple myeloma and HTLV-1 mediated tumorigenesis. Angiogenic disorders which may be treated or prevented by the compounds of this invention include solid tumors, ocular neovasculization, infantile haemangiomas. Infectious diseases which may be treated or prevented by the compounds of this invention include, but are not limited to, sepsis, septic shock, and Shigellosis. Viral diseases which may be treated or prevented by the compounds of this invention include, but are not limited to, acute hepatitis infection (including hepatitis A, hepatitis B and hepatitis C), HIV infection and CMV retinitis. Neurodegenerative diseases which may be treated or prevented by the compounds of this invention include, but are not limited to, Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis (ALS), epilepsy, seizures, Huntington's disease, traumatic brain injury, ischemic and hemorrhaging stroke, cerebral ischemias or neurodegenerative disease, including apoptosis-driven neurodegenerative disease, caused by traumatic injury, acute hypoxia, ischemia or glutamate neurotoxicity. “JNK-mediated conditions” also include ischemia/reperfusion in stroke, heart attacks, myocardial ischemia, organ hypoxia, vascular hyperplasia, cardiac hypertrophy, hepatic ischemia, liver disease, congestive heart failure, pathologic immune responses such as that caused by T cell activation and thrombin-induced platelet aggregation. In addition, JNK inhibitors of the instant invention may be capable of inhibiting the expression of inducible pro-inflammatory proteins. Therefore, other “JNK-mediated conditions” which may be treated by the compounds of this invention include edema, analgesia, fever and pain, such as neuromuscular pain, headache, cancer pain, dental pain and arthritis pain. The compounds of this invention are also useful as inhibitors of Src-family kinases, especially Src and Lck. For a general review of these kinases see Thomas and Brugge, Annu. Rev. Cell Dev. Biol. (1997) 13, 513; Lawrence and Niu, Pharmacol. Ther. (1998) 77, 81; Tatosyan and Mizenina, Biochemistry (Moscow) (2000) 65, 49. Accordingly, these compounds are useful for treating diseases or conditions that are known to be affected by the activity of one or more Src-family kinases. Such diseases or conditions include hypercalcemia, restenosis, hypercalcemia, osteoporosis, osteoarthritis, symptomatic treatment of bone metastasis, rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis, psoriasis, lupus, graft vs. host disease, T-cell mediated hypersensitivity disease, Hashimoto's thyroiditis, Guillain-Barre syndrome, chronic obtructive pulmonary disorder, contact dermatitis, cancer, Paget's disease, asthma, ischemic or reperfusion injury, allergic disease, atopic dermatitis, and allergic rhinitis. Diseases that are affected by Src activity, in particular, include hypercalcemia, osteoporosis, osteoarthritis, cancer, symptomatic treatment of bone metastasis, and Paget's disease. Diseases that are affected by Lck activity, in particular, include autoimmune diseases, allergies, rheumatoid arthritis, and leukemia. Compounds of formula II-A and I-B wherein. Ar2 is aryl are especially useful for treating diseases associated with the Src-family kinases, particularly Src or Lck. In addition to the compounds of this invention, pharmaceutically acceptable derivatives or prodrugs of the compounds of this invention may also be employed in compositions to treat or prevent the above-identified disorders. A “pharmaceutically acceptable derivative or prodrug” means any pharmaceutically acceptable salt, ester, salt of an ester or other derivative of a compound of this invention which, upon administration to a recipient, is capable of providing, either directly or indirectly, a compound of this invention or an inhibitorily active metabolite or residue thereof. Particularly favored derivatives or prodrugs are those that increase the bioavailability of the compounds of this invention when such compounds are administered to a mammal (e.g., by allowing an orally administered compound to be more readily absorbed into the blood) or which enhance delivery of the parent compound to a biological compartment (e.g., the brain or lymphatic system) relative to the parent species. Pharmaceutically acceptable prodrugs of the compounds of this invention include, without limitation, esters, amino acid esters, phosphate esters, metal salts and sulfonate esters. Pharmaceutically acceptable salts of the compounds of this invention include those derived from pharmaceutically acceptable inorganic and organic acids and bases. Examples of suitable acid salts include acetate, adipate, alginate, aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, citrate, camphorate, camphorsulfonate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, formate, fumarate, glucoheptanoate, glycerophosphate, glycolate, hemisulfate, heptanoate, hexanoate, hydrochloride, hydrobromide, hydroiodide, 2-hydroxyethanesulfonate, lactate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oxalate, palmoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, salicylate, succinate, sulfate, tartrate, thiocyanate, tosylate and undecanoate. Other acids, such as oxalic, while not in themselves pharmaceutically acceptable, may be employed in the preparation of salts useful as intermediates in obtaining the compounds of the invention and their pharmaceutically acceptable acid addition salts. Salts derived from appropriate bases include alkali metal (e.g., sodium and potassium), alkaline earth metal (e.g., magnesium), ammonium and N+(C1-4 alkyl)4 salts. This invention also envisions the quaternization of any basic nitrogen-containing groups of the compounds disclosed herein. Water or oil-soluble or dispersible products may be obtained by such quaternization. Pharmaceutically acceptable carriers that may be used in these pharmaceutical compositions include, but are not limited to, ion exchangers, alumina, aluminum stearate, lecithin, serum proteins, such as human serum albumin, buffer substances such as phosphates, glycine, sorbic acid, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, salts or electrolytes, such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinyl pyrrolidone, cellulose-based substances, polyethylene glycol, sodium carboxymethylcellulose, polyacrylates, waxes, polyethylene-polyoxypropylene-block polymers, polyethylene glycol and wool fat. The compositions of the present invention may be administered orally, parenterally, by inhalation spray, topically, rectally, nasally, buccally, vaginally or via an implanted reservoir. The term “parenteral” as used herein includes subcutaneous, intravenous, intramuscular, intra-articular, intra-synovial, intrasternal, intrathecal, intrahepatic, intralesional and intracranial injection or infusion techniques. Preferably, the compositions are administered orally, intraperitoneally or intravenously. Sterile injectable forms of the compositions of this invention may be aqueous or oleaginous suspension. These suspensions may be formulated according to techniques known in the art using suitable dispersing or wetting agents and suspending agents. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose, any bland fixed oil may be employed including synthetic mono- or di-glycerides. Fatty acids, such as oleic acid and its glyceride derivatives are useful in the preparation of injectables, as are natural pharmaceutically-acceptable oils, such as olive oil or castor oil, especially in their polyoxyethylated versions. These oil solutions or suspensions may also contain a long-chain alcohol diluent or dispersant, such as carboxymethyl cellulose or similar dispersing agents which are commonly used in the formulation of pharmaceutically acceptable dosage forms including emulsions and suspensions. Other commonly used surfactants, such as Tweens, Spans and other emulsifying agents or bioavailability enhancers which are commonly used in the manufacture of pharmaceutically acceptable solid, liquid, or other dosage forms may also be used for the purposes of formulation. The pharmaceutical compositions of this invention maybe orally administered in any orally acceptable dosage form including, but not limited to, capsules, tablets, aqueous suspensions or solutions. In the case of tablets for oral use, carriers commonly used include lactose and corn starch. Lubricating agents, such as magnesium. stearate, are also typically added. For oral administration in a capsule form, useful diluents include lactose and dried cornstarch. When aqueous suspensions are required for oral use, the active ingredient is combined with emulsifying and suspending agents. If desired, certain sweetening, flavoring or coloring agents may also be added. Alternatively, the pharmaceutical compositions of this invention may be administered in the form of suppositories for rectal administration. These can be prepared by mixing the agent with a suitable non-irritating excipient which is solid at room temperature but liquid at rectal temperature and therefore will melt in the rectum to release the drug. Such materials include cocoa butter, beeswax and polyethylene glycols. The pharmaceutical compositions of this invention may also be administered topically, especially when the target of treatment includes areas or organs readily accessible by topical application, including diseases of the eye, the skin, or the lower intestinal tract. Suitable topical formulations are readily prepared for each of these areas or organs. Topical application for the lower intestinal tract can be effected in a rectal suppository formulation (see above) or in a suitable enema formulation. Topically-transdermal patches may also be used. For topical applications, the pharmaceutical compositions may be formulated in a suitable ointment containing the active component suspended or dissolved in one or more carriers. Carriers for topical administration of the compounds of this invention include, but are not limited to, mineral oil, liquid petrolatum, white petrolatum, propylene glycol, polyoxyethylene, polyoxypropylene compound, emulsifying wax and water. Alternatively, the pharmaceutical compositions can be formulated in a suitable lotion or cream containing the active components suspended or dissolved in one or more pharmaceutically acceptable carriers. Suitable carriers include, but are not limited to, mineral oil, sorbitan monostearate, polysorbate 60, cetyl esters wax, cetearyl alcohol, 2-octyldodecanol, benzyl alcohol and water. For ophthalmic use, the pharmaceutical compositions may be formulated as micronized suspensions in isotonic, pH adjusted sterile saline, or, preferably, as solutions in isotonic, pH adjusted sterile saline, either with or without a preservative such as benzylalkonium chloride. Alternatively, for ophthalmic uses, the pharmaceutical compositions may be formulated in an ointment such as petrolatum. The pharmaceutical compositions of this invention may also be administered by nasal aerosol or inhalation. Such compositions are prepared according to techniques well-known in the art of pharmaceutical formulation and may be prepared as solutions in saline, employing benzyl alcohol or other suitable preservatives, absorption promoters to enhance bioavailability, fluorocarbons, and/or other conventional solubilizing or dispersing agents. The amount of JNK inhibitor that may be combined with the carrier materials to produce a single dosage form will vary depending upon the host treated, the particular mode of administration. Preferably, the compositions should be formulated so that a dosage of between 0.01-100 mg/kg body weight/day of the inhibitor can be administered to a patient receiving these compositions. It should also be understood that a specific dosage and treatment regimen for any particular patient will depend upon a variety of factors, including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, rate of excretion, drug combination, and the judgment of the treating physician and the severity of the particular disease being treated. The amount of inhibitor will also depend upon the particular compound in the composition. According to another embodiment, the invention provides methods for treating or preventing a JNK-mediated condition comprising the step of administering to a patient one of the above-described pharmaceutical compositions. The term “patient”, as used herein, means an animal, preferably a human. Preferably, that method is used to treat or prevent a condition selected from inflammatory diseases, autoimmune diseases, destructive bone disorders, proliferative disorders, infectious diseases, degenerative diseases, neurodegenerative diseases, allergies, reperfusion/ischemia in stroke, heart attacks, angiogenic disorders, organ hypoxia, vascular hyperplasia, cardiac hypertrophy, and thrombin-induced platelet aggregation, or any specific disease or disorder described above. Depending upon the particular JNK-mediated condition to be treated or prevented, additional drugs, which are normally administered to treat or prevent that condition, may be administered together with the inhibitors of this invention. For example, chemotherapeutic agents or other anti-proliferative agents may be combined with the JNK inhibitors of this invention to treat proliferative diseases. Those additional agents may be administered separately, as part of a multiple dosage regimen, from the JNK inhibitor-containing composition. Alternatively, those agents may be part of a single dosage form, mixed together with the JNK inhibitor in a single composition. In order that the invention described herein may be more fully understood, the following examples are set forth. It should be understood that these examples are for illustrative purposes only and are not to be construed as limiting this invention in any manner. EXAMPLE 1 Benzaldehyde oxime. To benzaldhyde (10.0 g, 94 mmol) in ethanol (50 mL) was added hydroxylamine hydrochloride (6.5 g, 94 mmol in H2O (50 mL) followed by Na2CO3 in H2O (50 mL). Reaction solution was stirred for 2 hr. Poured into brine and extracted twice with diethyl ether. Combined extracts were dried over MgSO4. Evaporation afforded benzaldehyde oxime (11.0 g, 96.5% yield) as a colorless oil. 1H NMR (CDCl3) δ 7.40-7.50 (m, 3H), 7.60-7.70 (m, 2H), 8.22 (s, 1H), 9.1 (bs, 1H). EXAMPLE 2 α-Chlorobenzaldehyde oxime (Benzoyl chloride oxime). To benzaldehyde oxime (12.2 g, 0.1 mol) in chloroform was added catalytic amount of pyridine, followed by N-chlorosuccinimide (13.35 g, 0.1 mol) at room temperature. The reaction mixture was stirred for 1.5 h, then saturated aqueous NaCl was added. The organic phase was washed with saturated aqueous NaCl (twice) and dried with MgSO4. The solvent was removed under reduced pressure. 13.85 g α-chlorobenzaldehyde oxime was obtained. The yield was 87%. EXAMPLE 3 1-(5-Methyl-3-phenyl-isoxazol-4-yl)-ethanone (Compound 3). To a solution of pentane-2,4-dione (13.23 g, 0.132 mol) and triethylamine (13.35 g, 0.132 mol) in ethanol was added α-chlorobenzaldehyde oxime (13.70 g, 0.088 mol) at room temperature. The reaction mixture was stirred overnight at room temperature. To the reaction was added ethyl acetate and saturated aqueous NaCl. The organic phase was washed with saturated aqueous NaCl (twice) and dried with MgSO4, and the organic solvent was removed under reduced pressure to provide 17.7 g of the title compound. The yield was 100%. EXAMPLE 4 4-(5-methyl-3-phenyl-isoxazol-4-yl)-pyrimidin-2-ylamine (Compound 5). The above Compound 3 (17.7 g, 0.088 mol) and dimethylformamide dimethyl acetal (DMF.DMA) (160 g, 0.132 mol) were refluxed overnight. To the reaction mixture was added ethyl acetate and saturated aqueous NaCl. The organic phase was washed with saturated aqueous NaCl (twice) and dried (MgSO4). The organic solvent was removed under reduced pressure, and the crude product material was dissolved in 200 mL methanol. To the solution was added guanidine hydrochloride (10.5 g, 0.110 mol) in 100 mL methanol, followed by sodium methoxide (6.17 g, 0.114 mol) in 100 mL methanol. The reaction mixture was refluxed overnight and then was cooled to room temperature. The reaction solvent was concentrated to approximately 100 mL total volume, and the precipitated product was filtered. The filtration cake afforded the title compound (9.3 g). The overall yield for two steps was 46%. EXAMPLE 5 [4-(5-Methyl-3-phenyl-isoxazol-4-yl)-pyrimidin-2-yl]-phenyl-amine (Compound IIA). To a solution of 50 mg (0.2 mmol) of 4-(5-methyl-3-phenyl-isoxazole-4-yl)-pyrimidin-2-ylamine in 1 mL of toluene was added successively 63 μL (0.6 mmol) of bromobenzene, 10 mg of tris(dibenzylideneacetone) dipalladium, 10 mg of BINAP and 39 mg (0.4 mmol) of sodium tert-butoxide. The mixture was heated at reflux for 16 h, diluted with ethyl acetate, filtered, washed successively with saturated aqueous sodium bicarbonate and brine, dried (MgSO4) and concentrated in vacuo. The residue was purified by column chromatography over silica gel eluted with ethyl acetate-hexanes 1:3, to afford 24 mg (36%) of the title compound as a yellow oil. EXAMPLE 6 5-Methyl-3-phenyl-isoxazole-4-carboxylic acid methyl ester. An ethanol solution of freshly prepared benzoyl chloride oxime (14.0 g, 90 mmol) (100 mL) was added dropwise, at 5° C. to methyl acetoacetate (11.18 g, 96 mmol) and triethyl amine (13 mL, 103 mmol) in ethanol (50 ml) After stirring for 12 hr at ambient temperature, the solution was diluted with CH2Cl2, washed with 1N HCl. saturated NaHCO3, brine, dried over MgSO4 and evaporated togive amber oil. Flash chromatography (silica) with 10% ethyl acetate in hexanes afforded the title compound (7.56 g, 39% yield) as a white solid: MS m/z MH+218 (100); 1H NMR (CDCl3) δ 2.78 (s, 3H), 3.81 (s, 3H), 7.45-7.55 (m, 3H), 7.65-7.69 (m, 2H). EXAMPLE 7 5-Methyl-3-phenyl-isoxazole-4-carboxylic acid. To 5-Methyl-3-phenyl-isoxazole-4-carboxylic acid methyl ester (0.853 g, 3.69 mmol) in methanol (12 mL) was added 2N NaOH (8 mL) the reaction solution was stirred at ambient temperature for 60 hr. The solution was dilute with waterand extracted twice with ethyl acetate. The combined extract was washed with brine and dried over MgSO4 and concentrated. Recrystallization (hexanes/ethyl acetate) afforded a white solid (0.540 g, 72% yield). EXAMPLE 8 5-Methyl-3-phenyl-isoxazole-4-carbonyl chloride. 5-Methyl-3-phenyl-isoxazole-4-carboxylic acid (0.54 g, 2.56 mmol) was treated with SOCl2 (2 mL) at 70° C. for 1 hr. Concentration in vacuum gave a yellow oil which was used without purification. EXAMPLE 9 3-(5-Methyl-3-phenyl-isoxazol-4-yl)-3-oxo-propionitrile. To cyanoacetic acid (0.43 g, 5.12 mmol) in THF at −78° C., containing one crystal of 1,1′-bipyridyl was added n-butyl lithium (6.4 mL, 10.24 mmol). The temperature was allowed to warm to 0° C. resulting in a pink colored solution. After cooling to −78° C., 5-Methyl-3-phenyl-isoxazole-4-carbonyl chloride (0.567 g, 2.56 mmol) in THF (5 mL) was added dropwise. The mixture was stirred at −78° C. for 1 hr. and at ambient temperature for an addition 1 hr. The reaction was quenched with 1N HCl (13 mL0 and extracted twice with CH2Cl2. Combined extracts were washed with saturated NaHCO3, brine, dried over MgSO4 to give the title compound (0.391 g, 67% yield). EXAMPLE 10 N-[5-(5-Methyl-3-phenyl-isoxazol-4-yl)-2H-pyrazol-3-yl]-benzamide. 3-(5-Methyl-3-phenyl-isoxazol-4-yl)-3-oxo-propionitrile (0.391. g, 1.73 mmol) in Ethanol (3 mL) was treated with hydrazine (0.168 mL, 3.46 mmol) and heated to reflux. Evaporation in vacuum gave 5-(5-Methyl-3-phenyl-isoxazol-4-yl)-2H-pyrazol-3-ylamine used without purification. To the resulting amine (0.039. g, 0.16 mmol) in dioxane was added triethyl amine followed by benzyl chloride (0.019 mL, 0.16 mmol). The reaction was stirred at 10° C. for 1 hr and 2 hr at ambient temperature. The solution was diluted with water extracted with ethyl acetate, washed with saturated NaHCO3, Brine, dried over MgSO4 and concentrated in vacuum. HPLC purification afforded 1.4 mg of title compound. EXAMPLE 11 1-Benzyloxy-3-(2-methylsulfanylpyrimidin-4-yl)-propan-2-one (Compound 7). To a stirred solution of 4-methyl-2-methylsulfanylpyrimidine (9.60 g, 68.5 mmol) in THF (150 mL) at −78° C. was added LDA (2.0 M THF/Hex, 41.1 mL, 82.2 mmol) dropwise over 10 min. The solution was stirred at −78° C. for 15 minutes, warmed to 0° C. for 10 minutes and recooled to −78° C. for 15 minutes. Then, a solution of 3-benzyloxy-N-methyl-N-methoxyacetamide (17.2 g, 82.2 mmol) in THF (30 mL) was added dropwise over 45 minutes. After 15 min. at −78° C., the solution was warmed to 0° C. and stirred for 30 min. The reaction was quenched with HCl (1M, 85 mL) and stirred for 1 h. The solution was poured into saturated NaHCO3 (300 mL), extracted with Et2O (3×200 mL), dried (MgSO4), filtered and concentrated. Flash chromatography (SiO2, 20% EtOAc-hexanes) provided the title compound (13.75 g, 47.7 mmol, 69% yield). EXAMPLE 12 4-[5-Benzyloxymethyl-3-(4-fluoro-phenyl)-isoxazol-4-yl]-2-methylsulfanyl-pyrimidine (Compound 8). To a stirred solution of the above compound 7 (13.75 g, 47.7 mmol) and Et3N (14.6 mL, 105 mmol) in EtOH (200 mL), was added a solution of 4-fluoro-benzoylchloride oxime (56 mmol) in EtOH (50 mL) over 30 min. The solution was stirred at 25° C. for 15 min. Then, the solution was heated to reflux for 90 min. The solution was cooled to 25° C. Additional Et3N (7.3 mL, 52 mmol) was added followed by dropwise addition of a solution of 4-fluoro-benzoylchloride oxime (38.5 mmol) in EtOH (50 mL) over 1 h. to drive the reaction to completion. The solution was refluxed for 1 h. until TLC indicated that all of the starting isoxazole was consumed. The solution was cooled to 25° C. and concentrated. The crude material was picked up in CH2Cl2 (50 mL) and poured into saturated aqueous NaHCO3 (150 mL), extracted with CH2Cl2 (3×150 mL), dried (MgSO4), filtered and concentrated. Flash chromatography (SiO2, 20% EtOAc-hexanes) provided the title compound (14.2 g, 34.8 mmol, 60%) in sufficient purity (>85%) for use in the next reaction. EXAMPLE 13 4-[5-Benzyloxymethyl-3-(4-fluoro-phenyl)-isoxazol-4-yl]-2-methanesulfonyl-pyrimidine (Compound 9). To a stirred solution of the above compound 8 (2.00 g, 4.91 mmol) in MeOH (50 mL) at 25° C. was added dropwise a solution of oxone (7.07 g, 11.5 mmol) in H2O (50 mL) over 10 min. After 20 h., the solution was poured into H2O (75 mL), extracted with CH2Cl2, (3×75 mL), dried (MgSO4), filtered and concentrated. Flash chromatography (SiO2, 45% EtOAc-hexanes) provided the title compound (1.60 g, 3.64 mmol, 74%). EXAMPLE 14 [3-(4-Fluoro-phenyl)-4-(2-methanesulfonyl-pyrimidin-4-yl)-isoxazol-5-yl]-methanol (Compound 10). To a stirred solution of the above compound 9 (750 mg, 1.70 mmol) in CHCl3 (8.5 mL) at 0° C. was added trimethylsilyl iodide (0.73 mL, 5.1 mmol). The reaction was stirred at 0° C. for 30 min. Then, additional trimethylsilyl iodide (0.48 mL, 3.4 mmol) was added. After 40 min. the solution was warmed to 25° C. and stirring was continued for 22 h. The solution was quenched with H2O-MeOH (2 mL) and stirred for 1 h. The solution was poured into saturated aqueous NaHCO3 (30 mL), extracted with EtOAc (3×30 mL), and concentrated. Flash chromatography (SiO2, 80% EtOAc-hexanes) provided the title compound (530 mg, 1.52 mmol, 89%). EXAMPLE 15 4-[5-(Bromomethyl)-3-(4-fluoro-phenyl)-isoxazol-4-yl]-2-methanesulfonyl-pyrimidine (Compound 11). To a stirred solution of the above compound 10 (250 mg, 0.716 mmol) and CBr4 (473 mg, 1.43 mmol) in CH2Cl2 (14 mL) at 25° C. was added PPh3 (244 mg, 0.93 mmol). After 10 min., additional PPh3 (50 mg, 0.19 mmol) was added to drive the reaction to completion. After 15 min., the solution was concentrated. Flash chromatography (SiO2, 50% EtOAc-hexanes) provided the title compound. (265 mg, 0.643 mmol, 90%). EXAMPLE 16 4-[3-(4-Fluoro-phenyl)-4-(2-methanesulfonyl-pyrimidin-4-yl)-isoxazol-5-ylmethyl]-morpholine (Compound 12). To a stirred solution of the above compound 11 (41 mg, 0.099 mmol) and Et3N (20 82 L, 0.15 mmol) in CH3CN (0.5 mL) at 25° C. was added morpholine (9.6 μL, 0.11 mmol). After15 min. the solution was concentrated. Preparative thin layer chromatography (SiO2, EtOAc) provided the title compound (29 mg, 0.069 mmol, 70%). EXAMPLE 17 4-{4-[3-(4-Fluoro-phenyl)-5-(morpholin 4-ylmethyl)-isoxazol-4-yl]pyrimidin-2-ylamino}cyclohexanol (Compound XIA-42). A stirred solution of Compound 13 (29 mg, 0.069 mmol) and trans-4-aminocyclohexanol (24 mg, 0.21 mmol) in DMSO (0.21 mL) was heated to 80° C. for 4 h. The solution was poured into half-saturated aqueous NaHCO3 (5 mL), extracted with EtOAc (5×5 mL), dried (MgSO4), filtered and concentrated. Flash chromatography (SiO2, 10% MeOH—CH2Cl2) provided material which was further purified by ion exchange chromatography (SCX resin, eluent: 0.25M NH3 in 50% MeOH—CH2Cl2) to give the title compound (27 mg, 0.057 mmol, 83%). EXAMPLE 18 4-[5-Ethoxmethyl-3-(4-fluoro-phenyl)-isoxazol-4-yl]-2-methylsulfanyl-pyrimidine (Compound 13). To a stirred solution of the above compound 8 (103 mg, 0.27 mmol) in EtOH (2.0 mL) at 25° C. was added NaOEt (21% w/v EtOH, 0.40 mL, 1.23 mmol). After 2 h. the reaction was quenched with saturated aqueous NH4Cl (3 mL), CH2Cl2 (3×5 mL); dried (MgSO4), filtered and concentrated. Flash chromatography (SiO2, 25% EtOAc-hexanes) provided the title compound (58 mg, 0.17 mmol, 62%). EXAMPLE 19 4-[5-Ethoxymethyl-3-(4-fluoro-phenyl)-isoxazol-4-yl]-2-methanesulfonyl-pyrimidine (Compound 14). This compound was prepared in a manner similar to that described above in Example 13, except starting from the above compound 13 (58 mg, 0.17 mmol) to provide the title compound (64 mg, 0.17 mmol, 100%) which was used directly in the next reaction without purification or characterization. EXAMPLE 20 Cyclohexyl-{4-[5-ethoxymethyl-3-(4-fluoro-phenyl)-isoxazol-4-yl]-pyrimidin-2-yl}amine (Compound XIA-43) This compound was prepared in a manner similar to that described above in Example 17, starting from the above compound 14 (64 mg, 0.17 mmol) and cyclohexylamine (58 μL, 0.51 mmol) to provide the title compound as crude product. After HPLC purification (C-18, gradient elution, 10-90% H2O—CH3CN) and extraction into EtOAc, the crude product was converted to the HCl salt with HCl-Et2O (1M, 1 mL). The solvents were removed in vacuo the give the title compound as the HCl salt (55 mg, 0.13 mmol, 76% over two steps from compound 13). EXAMPLE 21 Cyclohexyl-{4-[5-benzyloxymethyl-3-(4-fluoro-phenyl)-isoxazol-4-yl]-pyrimidin-2-yl}amine (Compound XIA-44) This compound was prepared in a manner similar to that described above in Example 17 starting from the above compound 9 (500 mg, 1.14 mmol) and cyclohexylamine (340 μL, 3.42 mmol). Flash chromatography (SiO2, 30% EtOAc-hexanes) provided the title compound (488 mg, 1.06 mmol, 93%). EXAMPLE 22 [4-(2-Cyclohexylamino-pyrimidin-4-yl)-3-(4-fluoro-phenyl)-isoxazol-5-yl]methanol (Compound XIA-45) A stirred solution of the above compound XIA-44 (461 mg, 1.01 mmol) in TFA-H2O (3:1, 8 mL) was heated to 80° C. for 20 h. The solution was concentrated, and the crude mixture was taken up in CH2Cl2 (25 mL), poured into saturated aqueous NaHCO3 (30 mL), extracted with CH2Cl2 (3×25 mL), dried (MgSO4), filtered and concentrated. TLC (50% EtOAc-hexanes) indicated about 50% consumption of starting compound XIA-44. The crude material was dissolved in TFA-H2O (3:1, 8 mL) and the resulting solution was heated to 100° C. for 22 h. The solution was concentrated, and the crude mixture was taken up in CH2Cl2 (25 mL), poured into saturated aqueous NaHCO3 (30 mL), extracted with CH2Cl2 (3×25 mL), dried (MgSO4), filtered and concentrated. Flash chromatography (SiO2, 40% EtOAc-hexanes) provided the title compound (313 mg, 0.85 mmol, 84%). EXAMPLE 23 1-(2-Bromo-pyridin-4-yl)-propan-2-one (Compound 16). To a stirred solution of 2-bromo-4-methylpyridine (Compound 15) (20.20 g, 117.4 mmol) in THF (250 mL) at −78° C. was added LDA (2.0 M THF/Hex, 70.5 mL, 141 mmol) dropwise over 10 min. The solution was stirred at −78° C. for 35 min. Then a solution of N-methoxy-N-methyl acetamide (14.5 g, 141 mmol) in THF (30 mL) was added dropwise over 10 min. After 15 min. at −78° C., the solution was warmed to 0° C. and stirred for 1 h. The solution was poured into H2O (250 mL), extracted with Et2O (3×250 mL), dried (MgSO4), filtered and concentrated. Flash chromatography (SiO2, 20% EtOAc-hexanes) provided the title compound (16.75 g, 78.2 mmol, 67%). EXAMPLE 24 2-Bromo-4-(5-methyl-3-phenyl-isoxazol-4-yl)-pyridine (Compound 17a). To a stirred solution of Compound 16 (1.71 g, 8.0 mmol) and Et3N (2.23 mL, 16 mmol) in EtOH (16 mL) was added a solution of benzoylchloride oxime (1.62 g, 10.4 mmol) in EtOH (16 mL) over 90 min. The solution was stirred at 25° C. for 90 min. Then, the solution was heated to reflux for 24 h. The solution was cooled to 25° C. and concentrated. The crude material was taken up in CH2Cl2 (50 mL) and poured into saturated aqueous NaHCO3 (50 mL), extracted with CH2Cl2 (3×50 mL), dried (Na2SO4), and filtered. Flash chromatography (SiO2, 20% EtOAc-hexanes) provided the title compound (1.32 g, 4.19 mmol, 52%). 2-Bromo-4-[3-(4-fluoro-phenyl)-5-methyl-isoxazol-4-yl]-pyridine (Compound 17b) was similarly prepared starting with 4-fluorobenzoylchloride oxime. EXAMPLE 25 2-Bromo-4-(5-bromomethyl-3-phenyl-isoxazol-4-yl)-pyridine (Compound 18a). A stirred solution of the above Compound 17a (404 mg, 1.28 mmol), N-bromosuccinimide (239 mg, 1.35 mmol) and AIBN (11 mg, 0.064 mmol) in CCl4 (3 mL) was heated to reflux and placed under a 300 W lamp for 18 h. The solution was diluted with CH2Cl2 (15 mL), extracted with H2O (3×10 mL), brine (40 mL), dried (MgSO4), filtered and concentrated. Flash chromatography (SiO2, 15-20% EtOAc-hexanes) provided the title compound (287 mg, 0.728 mmol, 57%). 2-Bromo-4-[5-bromomethyl-3-(4-fluoro-phenyl)-isoxazol-4-yl]-pyridine (Compound 18b) was similarly prepared starting with Compound 17b. EXAMPLE 26 2-Bromo-4-(5-methoxymethyl-3-(4-fluoro-phenyl)-isoxazol-4-yl)-pyridine (Compound 19b). To the above Compound 18b (200 mg, 0.485 mmol) was added NaOMe (0.5 M in MeOH, 2.0 mL, 1.0 mmol). The solution was stirred at 25° C. for 90 min. Then, the solution was poured into brine, extracted with EtOAc (4×15 mL), dried (MgSO4), filtered through a silica plug. Evaporation of the solvent provided the title compound (175 mg, 0.482 mmol, 99%). EXAMPLE 27 4-(4-(2-Bromo-pyridin-4-yl)-3-phenyl-isoxazol-5-ylmethyl)-morpholine (Compound 20a). A stirred solution of the above Compound 18a (484 mg, 1.22 mmol), morpholine (0.45 mL, 5.1 mmol) and K2CO3 (340 mg, 2.45 mmol) in anhydrous DMF (2 mL) was warmed to 40° C. for 18 h. The solution was poured into brine (10 ml), extracted with CH2Cl2 (3×15 mL), dried (MgSO4), and filtered. Flash chromatography (SiO2, 50% EtOAc-hexanes) provided the title compound (461 mg, 1.15 mmol, 94%). EXAMPLE 28 [4-(5-Methyl-3-phenyl-isoxazol-4-yl)-pyridin-2-yl]phenyl-amine (Compound IIA-52). To a stirred solution of the above Compound 17a (20 mg, 0.063 mmol), aniline (7.0 μL, 0.076 mmol) and BINAP (5.6 mg, 0.009 mmol) in toluene (0.6 mL) at 25° C. was added Pd2(dba)3 (2.7 mg, 0.003 mmol) followed by NaOtBu (9.1 mg, 0.095 mmol). The solution was heated to 80° C. for 2 h. The solution was cooled, filtered and concentrated. Preparative thin layer chromatography (SiO2, 5% EtOAc/CH2Cl2) provided the title compound (12.6 mg, 0.0385 mmol, 61%). EXAMPLE 29 Cyclohexyl-[4-(5-methoxymethyl-3-(4-fluoro-phenyl)-isoxazol-4-yl)-pyridin-2-yl]-amine (Compound XIA-29). To a stirred solution of the above Compound 19b (20 mg, 0.050 mmol), cyclohexylamine (11 μL, 0.13 mmol), and BINAP (4.7 mg, 0.0075 mmol) in toluene (0.4 mL) at 25° C. was added Pd2(dba)3 (2.3 mg, 0.0025 mmol) followed by NaOtBu (12 mg, 0.13 mmol). The solution was heated to 80° C. for 15 h. The solution was cooled, poured into H2O (5 mL), extracted with EtOAc (4×5 mL), dried (MgSO4), filtered and concentrated. HPLC (gradient elution, 90-10% H2O—CH3CN) provided the title compound (9.1 mg, 0.022 mmol, 44%). EXAMPLE 30 3-Methyl-5-phenyl-isoxazole-4-carbonitrile (Compound 24). To an ethyl alcohol solution of benzoylacetonitrile was added 1.5 eq of triethyl amine, followed by 1.5 eq of acetylchloride oxime, the reaction mixture was stirred at r.t. for 4 hours. To the reaction mixture was added ethyl acetate and brine. The organic phase was dried with magnesium sulfate and the solvent was removed under reduced pressure. After chromatographic purification the title compound was obtained in 72% yield. EXAMPLE 31 3-Methyl-5-phenyl-isoxazole-4-carbaldehyde (Compound 25). To a toluene solution of the above compound 24 was added 1.2 eq of DIBAL-H/HAX at 0° C. The reaction was stirred at 0° C. for 3 hours, allowed to warm to room temperature and was stirred at r.t. overnight. The reaction mixture was transfered to 1N HCl slowly and then extracted with ethyl acetate. The organic phase was dried over magnesium sulfate and concentrated under reduced pressure. The crude product was purified by chromatograph providing the title compound in 57% yield. EXAMPLE 32 1-(3-Methyl-5-phenyl-isoxazol-4-yl)-ethanol (Compound 26). To the THF solution of the above Compound 25 was slowly added 1.4 eq of methylmagnesium bromide at room temperature. The reaction mixture was stirred at r.t. for 1 h. To the reaction mixture was added ethyl acetate and 1N HCl. The organic phase was washed with brine and dried over magnesium sulfate. The solvent was removed under reduced pressure, and the crude product, obtained in 96% yield, was used directly for the next step without purification. EXAMPLE 33 1-(3-Methyl-5-phenyl-isoxazol-4-yl)-ethanone (Compound 27). To a dichlordmethane solution of oxalyl chloride was added DMSO at −78° C., the mixture was stirred at −78° C. for 15 min and followed by addition of a dichloromethane solution of compound the above Compound 26. The reaction mixture was stirred for 30 min at −78° C., then triethylamine was added, after which the reaction mixture was allowed to warm to room temperature gradually. To the reaction mixture was added ethyl acetate and brine. The organic phase was dried over magnesium sulfate, and the solvent was removed under reduced pressure. The crude product, obtained in 94% yield, was used directly for the next step without purification. EXAMPLE 34 3-Dimethylamino-1-(3-methyl-5-phenyl-isoxazol-4-yl)-propenone (Compound 28). A toluene solution of the above Compound 27 and excess DMF-DMA was refluxed for 20 hours. To the reaction mixture was added ethyl acetate and brine, the organic phase was dried over magnesium sulfate, and the solvent was then removed under reduced pressure. The crude product was used for the next step without purification. EXAMPLE 35 4-(3-Methyl-5-phenyl-isoxazol-4-yl)-2-methylsulfanyl-pyrimidine (Compound 29). A methanol suspension of the above Compound 28, 2 equivalents: of thiourea and 1.5 equivalents of sodium methoxide was refluxed for 2 days. To the reaction mixture was added ethyl acetate and 1N HCl, the organic phase was washed with brine and dried over magnesium sulfate, and the solvent was then removed under reduced pressure. The crude product was dissolved in chloroform, to it was added 1.5 eq of iodomethane and 1.5 eq of pyridine. The reaction mixture was stirred at r.t. for 2 hours. To the reaction mixture was added dichloromethane and 1N HCl, the organic phase was washed with brine and dried with magnesium sulfate. The solvent was removed under reduced pressure, and the crude product was purified by chromatography to provide the title compound. The yield was 32%. EXAMPLE 36 4-(3-Methyl-5-phenyl-isoxazol-4-yl)-2-methanesulfonyl-pyrimidine (Compound 30). To a dichloromethane solution of the above Compound 29 was added 2 eq of m-CPBA, and the reaction was stirred at r.t. for overnight. The reaction mixture was washed with 1N NaOH twice and brine twice and dried with magnesium sulfate. The solvent was removed under reduced pressure and the crude product was purified by chromatograph to provide the title compound in 79% yield. EXAMPLE 37 Compounds IB. A DMSO solution of the above Compound 30 and 3 equivalents of desired amine was heated at 80° C. for 4 hours. After analytical HPLC indicated the reaction was completed, the crude product was purified by reversed HPLC to provide the desired Compound IB. The yield is generally greater than 80%. The following examples demonstrate how the compounds of this invention may be tested as protein kinase inhibitors, especially inhibitors of c-Jun-N-terminal kinases. EXAMPLE 38 Cloning, Expression and Purification of JNK3 Protein A BLAST search of the EST database using the published JNK3α1 cDNA as a query identified an EST clone, (#632588) that contained the entire coding sequence for human JNK3α1. Polymerase chain reactions (PCR) using pfu polymerase (Strategene) were used to introduce restriction sites into the cDNA for cloning into the pET-15B expression vector at the NcoI and BamHI sites. The protein was expressed in E. coli. Due to the poor solubility of the expressed full-length protein (Met 1-Gln 422), an N-terminally truncated protein starting at Ser residue at position 40 (Ser 40) was produced. This truncation corresponds to Ser 2 of JNK1 and JNK2 proteins, and is preceded by a methionine (initiation) and a glycine residue. The glycine residue was added in order to introduce an NcoI site for cloning into the expression vector. In addition, systematic C-terminal truncations were performed by PCR to identify a construct that give rise to diffraction-quality crystals. One such construct encodes amino acid residues Ser40-Glu402 of JNK3α1 and is preceded by Met and Gly residues. The construct was prepared by PCR using deoxyoligonucleotides: 5′ GCTCTAGAGCTCCATGGGCAGCAAAAGCAAAGTTGACAA 3′ (forward primer with initiation codon underlined) (SEQ ID NO:1) and 5′ TAGCGGATCCTCATTCTGAATTCATTACTTCCTTGTA 3′ (reverse primer with stop codon underlined) (SEQ ID NO:2) as primers and was confirmed by DNA sequencing. Control experiments indicated that the truncated JNK3 protein had an equivalent kinase activity towards myelin basic protein when activated with an upstream kinase MKK7 in vitro. E. coli strain BL21 (DE3) (Novagen) was transformed with the JNK3 expression construct and grown at 30° C. in LB supplemented with 100 μg/ml carbenicillin in shaker flasks until the cells were in log phase (OD600˜0.8). Isopropylthio-β-D-galactosidase (IPTG) was added to a final concentration of 0.8 mM and the cells were harvested 2 hours later by centrifugation. E. coli cell paste containing JNK3 was resuspended in 10 volumes/g lysis buffer (50 mM HEPES, pH 7.2, containing 10% glycerol (v/v), 100 mM NaCl, 2 mM DTT, 0.1 mM PMSF, 2 μg/ml Pepstatin, 1 μg/ml each of E-64 and Leupeptin). Cells were lysed on ice using a microfluidizer and centrifuged at 100,000×g for 30 min at 4° C. The 100,000×g supernatant was diluted 1:5 with Buffer A (20 mM HEPES, pH 7.0, 10% glycerol (v/v), 2 mM DTT) and purified by SP-Sepharose (Pharmacia) cation-exchange chromatography (column dimensions: 2.6×20 cm) at 4° C. The resin was washed with 5 column volumes of Buffer A, followed by 5 column volumes of Buffer A containing 50 mM NaCl. Bound JNK3 was eluted with a 7.5 column volume linear gradient of 50-300 mM NaCl. JNK3 eluted between 150-200 mM NaCl. EXAMPLE 39 Activation of JNK3 5 mg of JNK3 was diluted to 0.5 mg/ml in 50 mM HEPES buffer, pH 7.5, containing 100 mM NaCl, 5 mM DTT, 20 mM MgCl2 and 1 mM ATP. GST-MKK7(DD) was added at a molar ratio of 1:2.5 GST-MKK7:JNK3. After incubation for 30 minutes at 25° C., the reaction mixture was concentrated 5-fold by ultrafiltration in a Centriprep-30 (Amicon, Beverly, Mass.), diluted to 10 ml and an additional 1 mM ATP added. This procedure was repeated three times to remove ADP and replenish ATP. The final addition of ATP was 5 mM and the mixture incubated overnight at 40° C. The activated JNK3/GST-MKK7 (DD) reaction mixture was exchanged into 50 mM HEPES buffer, pH 7.5, containing 5 mM DTT and 5% glycerol (w/v) by dialysis or ultrafiltration. The reaction mixture was adjusted to 1.1 M potassium phosphate, pH 7.5, and purified by hydrophobic interaction chromatography (at 25° C.) using a Rainin Hydropore column. GST-MKK7 and.unactivated JNK3 do not bind under these conditions such that when a 1.1 to 0.05 M potassium phosphate gradient is developed over 60 minutes at a flow rate of 1 ml/minute, doubly phosphorylated JNK3 is separated from singly phosphorylated JNK. Activated JNK3 (i.e. doubly. phosphorylated JNK3) was stored at −70° C. at 0.25-1 mg/ml. EXAMPLE 40 JNK Inhibition Assays Compounds were assayed for the inhibition of JNK3 by a spectrophotometric coupled-enzyme. assay. In this assay, a fixed concentration of activated JNK3 (10 nM) was incubated with various concentrations of a potential inhibitor dissolved in DMSO for 10 minutes at 30° C. in a buffer containing 0.1 M HEPES buffer, pH 7.5, containing 10 mM MgCl2, 2.5 mM phosphoenolpyruvate, 200 μM NADH, 150 μg/mL pyruvate kinase, 50 μg/mL lactate dehydrogenase, and 200 μM EGF receptor peptide. The EGF receptor peptide has the sequence KRELVEPLTPSGEAPNQALLR, and is a phosphoryl acceptor in the JNK3-catalyzed kinase reaction. The reaction was initiated by the addition of 10 μM ATP and the assay plate is inserted into the spectrophotometer's assay plate compartment that was maintained at 30° C. The decrease of absorbance at 340 nm was monitored as a function of time. The rate data as a function of inhibitor concentration was fitted to competitive inhibition kinetic model to determine the Ki. For selected compounds of this invention, activity in the JNK inhibition assay is shown in Table 8. Compounds having a Ki less than 0.1 micromolar (μM) are rated “A”, compounds having a Ki between 0.1 and 1 μM are rated “B” and compounds having a Ki greater than 1 μM are rated “C”. TABLE 8 Activity in the JNK3 Inhibition Assay. No. Activity No. Activity No. Activity IIA-1 A IIA-2 — IIA-3 A IIA-4 — IIA-5 A IIA-6 A IIA-7 A IIA-8 A/B IIA-9 B IIA-10 B IIA-11 A IIA-12 B/C IIA-13 C IIA-14 B IIA-15 B IIA-16 — IIA-17 — IIA-18 — IIA-19 — IIA-20 IIA-21 — IIA-22 — IIA-23 — IIA-24 — IIA-25 — IIA-26 — IIA-27 — IIA-28 — IIA-29 — IIA-30 — IIA-31 — IIA-32 A IIA-33 A IIA-34 A IIA-35 A IIA-36 A IIA-37 A IIA-38 A IIA-39 A IIA-40 A IIA-41 A IIA-42 A IIA-43 A IIA-44 A IIA-45 A IIA-46 A IIA-47 A IIA-48 A IIA-49 A IIA-50 A IIA-51 A IIA-52 A IIA-53 A IIA-54 A IIA-55 A IIA-56 A IIA-57 A IIA-58 A IIA-59 A IIA-60 A IIA-61 A IIA-62 A IIA-63 A IIA-64 A IIA-65 A IIA-66 A IIA-67 A IIA-68 A IIA-69 A IIA-70 A/B IIA-71 A/B IIA-72 A/B IIA-73 B IIA-74 B IIA-75 B IIA-76 B IIA-77 B IIA-78 B IIA-79 B IIA-80 B IIA-81 B IIA-82 B IIA-83 B IIA-84 B IIA-85 C IIA-86 C IIA-87 C IIA-88 — IIA-89 — IIA-90 A IIA-91 A IIA-92 A IIA-93 A IIA-94 A IIA-95 A IIA-96 A IIA-97 A IIA-98 A IIA-99 A IIA-100 A IIA-101 A IIA-102 A IIA-103 A IIA-104 A IIA-105 A IIA-106 B IIA-107 C IIA-108 A IIA-109 A IIA-110 C IIA-111 C IIA-112 C IIA-113 B IIA-114 B IIA-115 B IIA-116 C IIA-117 B IIA-118 B IIA-119 B IIA-120 B IIA-121 C IIA-122 B IIA-123 B IIA-124 B IIA-125 B IIA-126 B IIA-127 B IIA-128 B IIA-129 B IIA-130 A IIA-131 A IIA-132 A IIA-133 A IIA-134 A IIA-135 B IIA-136 — IIA-137 — IIA-138 — IIAA-1 — IIAA-2 — IIAA-3 — IIAA-4 B IIAA-5 — IIAA-6 — IIAA-7 — IIAA-8 — IIAA-9 — IIAA-10 A IIAA-11 A IIAA-12 A IIAA-13 A IIAA-14 A IIAA-15 B IIAA-16 A IIAA-17 C IIAA-18 B IIAA-19 A IIAA-20 B IIAA-21 B IIAA-22 B IIAA-23 B IIAA-24 A IIAA-25 A IIAA-26 C IIAA-27 B IIAA-28 C IIAA-29 B IIAA-30 C IIAA-31 A IIAA-32 B IIAA-33 A IIAA-34 A IIAA-35 A IIAA-36 A IIAA-37 A IIAA-38 A IIAA-39 B IIIA-1 B IIIA-2 C IIIA-3 B IIIA-4 C IIIA-5 C IIIA-6 B IIIA-7 B IIIA-8 B IIIA-9 C IIIA-10 C IIIA-11 B IIIA-12 B IIIA-13 — IIIA-14 B IIIA-15 A IIIA-16 — IIIA-17 — IIIA-18 B IIIA-19 B IIIA-20 B IIIA-21 B IIIA-22 C IIIA-23 C IIIA-24 C IIIA-25 C IIIA-26 C IIIA-27 C IIIA-28 C IIIA-29 C IIIA-30 B IIIA-31 B IIIA-32 B IIIA-33 B IIIA-34 C IIIA-35 C IIIA-36 C IIIA-37 C IIIA-38 C IIIA-39 C IIIA-40 C IIIA-41 C IIIA-42 B IIIA-43 A IIIA-44 B IIIA-45 B IIIA-46 B IIIA-47 B IIIA-48 B IIIA-49 B IIIA-50 B IIIA-51 B IIIA-52 B IIIA-53 B IIIA-54 B IIIA-55 B IIIA-56 B IIIA-57 B IIIA-58 B IIIA-59 B IIIA-60 B IIIA-61 B IIIA-62 B IIIA-63 B IIIA-64 B IIIA-65 B IIIA-66 B IIIA-67 B IIIA-68 B IIIA-69 B IIIA-70 B IIIA-71 B IIIA-72 B IIIA-73 B IIIA-74 A IIIA-75 B IIIA-76 — IIIA-77 — IIIA-78 — IIIA-79 — IIIA-80 — IIIA-81 — IIIA-82 — IIIA-83 — IIIA-84 — IIIA-85 — IIIA-86 — IIIA-87 — IIIA-88 — IIIA-89 — IIIA-90 — IIIA-91 — IIIA-92 — IIIA-93 — IIIA-94 — IIIA-95 — IIIA-96 — IIIA-97 — XA-1 B XA-2 C XA-3 B XA-4 B XA-5 B XA-6 — XIA-1 — XIA-2 — XIA-3 — XIA-4 — XIA-5 — XIA-6 — XIA-7 — XIA-8 — XIA-9 — XIA-10 — XIA-11 — XIA-12 — XIA-13 — XIA-14 — XIA-15 — XIA-16 — XIA-17 — XIA-18 — XIA-19 — XIA-20 — XIA-21 — XIA-22 — XIA-23 — XIA-24 — XIA-25 — XIA-26 — XIA-27 — XIA-28 — XIA-29 — XIA-30 — XIA-31 — XIA-32 — XIA-33 — XIA-34 — XIA-35 — XIA-36 — XIA-37 — XIA-38 — XIA-39 — XIA-40 — XIA-41 — XIA-42 — XIA-43 — XIA-44 — XIA-45 A XIA-46 A XIA-47 A XIA-48 A XIA-49 A XIA-50 A XIA-51 A XIA-52 A XIA-53 A EXAMPLE 41 Src Inhibition Assays The compounds were assayed as inhibitors of full length recombinant human Src kinase (from Upstate Biotechnology, cat. no. 14-117) expressed and purified from baculo viral cells. Src kinase activity was monitored by following the incorporation of 33P from ATP into the tyrosine of a random poly Glu-Tyr polymer substrate of composition, Glu:Tyr=4:1 (Sigma, cat. no. P-0275). The following were the final concentrations of the assay components: 0.05 M HEPES, pH 7.6, 10 mM MgCl2, 2 mM DTT, 0.25 mg/ml BSA, 10 μM ATP (1-2 μCi 33P-ATP per reaction), 5 mg/ml poly Glu-Tyr, and 1-2 units of recombinant human Src kinase. In a typical assay, all the reaction components with the exception of ATP were pre-mixed and aliquoted into assay plate wells. Inhibitors dissolved in DMSO were added to the wells to give a final DMSO concentration of 2.5%. The assay plate was incubated at 30° C. for 10 min before initiating the reaction with 33P-ATP. After 20 min of reaction, the reactions were quenched with 150 μl of 10% trichloroacetic acid (TCA) containing 20 mM Na3PO4. The quenched samples were then transferred to a 96-well filter plate (Whatman, UNI-Filter GF/F Glass Fiber Filter, cat no. 7700-3310) installed on a filter plate vacuum manifold. Filter plates were washed fourtimes with 10% TCA containing 20 mM Na3PO4 and then 4 times with methanol. 200 μl of scintillation fluid was then added to each well. The plates were sealed and the amount of radioactivity associated with the filters was quantified on a TopCount scintillation counter. The most active compounds in the Src assay were found to be those compounds of formula I where G is an optionally substituted aryl and R1 is Ar2. EXAMPLE 42 Lck Inhibition Assays The compounds were assayed as inhibitors of lck kinase purified from bovine thymus (from Upstate Biotechnology, cat. no. 14-106). Lck kinase activity was monitored by following the incorporation of 33P from ATP into the tyrosine of a random poly Glu-Tyr polymer substrate of composition, Glu:Tyr=4:1 (Sigma, cat. no. P-0275). The following were the final concentrations of the assay components: 0.05 M HEPES, pH 7.6, 10 mM MgCl2, 2 mM DTT, 0.25 mg/ml BSA, 10 μM ATP (1-2 μCi 33P-ATP per reaction), 5 mg/ml poly Glu-Tyr, and 1-2 units of lck kinase. In a typical assay, all the reaction components with the exception of ATP were pre-mixed and aliquoted into assay plate wells. Inhibitors dissolved in DMSO were added to the wells to give a final DMSO concentration of 2.5%. The assay plate was incubated at 30° C. for 10 min before initiating the reaction with 33P-ATP. After 20 min of reaction, the reactions were quenched with 150 μl of 10% trichloroacetic acid (TCA) containing 20 mM Na3PO4. The quenched samples were then transferred to a 96-well filter plate (Whatman, UNI-Filter GF/F Glass Fiber Filter, cat no. 7700-3310) installed on a filter plate vacuum manifold. Filter plates were washed four times with 10% TCA containing 20 mM Na3PO4 and then 4 times with methanol. 200 μl of scintillation fluid was then added to each well. The plates were sealed and the amount of radioactivity associated with the filters was quantified on a TopCount scintillation counter. The most active compounds in the Lck assay were found to be those compounds of formula I where G is an optionally substituted aryl and R1 is Ar2. While we have described a number of embodiments of this invention, it is apparent that our basic examples may be altered to provide other embodiments which utilize the compounds and methods of this invention. Therefore, it will be appreciated that the scope of this invention is to be defined by the appended claims rather than by the specific embodiments which have been represented by way of example. | <SOH> BACKGROUND OF THE INVENTION <EOH>Mammalian cells respond to extracellular stimuli by activating signaling cascades that are mediated by members of the mitogen-activated protein (MAP) kinase family, which include the extracellular signal regulated kinases (ERKs), the p38 MAP kinases and the c-Jun N-terminal kinases (JNKs). MAP kinases (MAPKs) are activated by a variety of signals including growth factors, cytokines, UV radiation, and stress-inducing agents. MAPKs are serine/threonine kinases and their activation occur by dual phosphorylation of threonine and tyrosine at the Thr-X-Tyr segment in the activation loop. MAPKs phosphorylate various substrates including transcription factors, which in turn regulate the expression of specific sets of genes and thus mediate a specific response to the stimulus. One particularly interesting kinase family are the c-Jun NH 2 -terminal protein kinases, also known as JNKs. Three distinct genes, JNK1, JNK2, JNK3 have been identified and at least ten different splicing isoforms of JNKs exist in mammalian cells [Gupta et al., EMBO J., 15:2760-70 (1996)]. Members of the JNK family are activated by proinflammatory cytokines, such as tumor necrosis factor-α (TNFα) and interleukin-1 β (IL-1β), as well as by environmental stress, including anisomycin, UV irradiation, hypoxia, and osmotic shock [Minden et al., Biochemica et Biophysica Acta, 1333:F85-F104 (1997)]. The down-stream substrates of JNKs include transcription factors c-Jun, ATF-2, Elk1, p53 and a cell death domain protein (DENN) [Zhang et al. Proc. Natl. Acad. Sci. USA, 95:2586-91 (1998)]. Each JNK isoform binds to these substrates with different affinities, suggesting a regulation of signaling pathways by substrate specificity of different JNKs in vivo (Gupta et al., supra) JNKs, along with other MAPKs, have been implicated in having a role in mediating cellular response to cancer, thrombin-induced platelet aggregation, immunodeficiency disorders, autoimmune diseases, cell death, allergies, osteoporosis and heart disease. The therapeutic targets related to activation of the JNK pathway include chronic myelogenous leukemia (CML), rheumatoid arthritis, asthma, osteoarthritis, ischemia, cancer and neurodegenerative diseases. Several reports have detailed the importance of JNK activation associated with liver disease or episodes of hepatic ischemia ([ Nat. Genet. 21:326-9 (1999); FEBS Lett. 420:201-4 (1997); J. Clin. Invest. 102:1942-50 (1998); Hepatology 28:1022-30 (1998)]. Therefore, inhibitors of JNK may be useful to treat various hepatic disorders. A role for JNK in cardiovascular disease such as myocardial infarction or congestive heart failure has also been reported as it has been shown JNK mediates hypertrophic responses to various forms of cardiac stress [ Circ. Res. 83:167-78 (1998); Circulation 97:1731-7 (1998); J. Biol. Chem. 272:28050-6 (1997); Circ. Res. 79:162-73 (1996); Circ. Res. 78:947-53 (1996); J. Clin. Invest. 97:508-14 (1996)]. It has been demonstrated that the JNK cascade also plays a role in T-cell activation, including activation of the IL-2 promoter. Thus, inhibitors of JNK may have therapeutic value in altering pathologic immune responses [ J. Immunol. 162:3176-87 (1999); Eur. J. Immunol. 28:3867-77 (1998); J. Exp. Med. 186:941-53 (1997); Eur. J. Immunol. 26:989-94 (1996)]. A role for JNK activation in various cancers has also been established, suggesting the potential use of JNK inhibitors in cancer. For example, constitutively activated JNK is associated with HTLV-1 mediated tumorigenesis [ Oncogene 13:135-42 (1996)]. JNK may play a role in Kaposi's sarcoma (KS) because it is thought that the proliferative effects of bFGF and OSM on KS cells are mediated by their activation of the JNK signaling pathway [ J. Clin. Invest. 99:1798-804 (1997)]. Other proliferative effects of other cytokines implicated in KS proliferation, such as vascular endothelial growth factor (VEGF), IL-6 and TNFα, may also be mediated by JNK. In addition, regulation of the c-jun gene in p210 BCR-ABL transformed cells corresponds with activity of JNK, suggesting a role for JNK inhibitors in the treatment for chronic myelogenous leukemia (CML) [ Blood 92:2450-60 (1998)]. JNK1 and JNK2 are widely expressed in a variety of tissues. In contrast, JNK3, is selectively expressed in the brain and to a lesser extent in the heart and testis [Gupta et al., supra; Mohit et al., Neuron 14:67-78 (1995); Martin et al., Brain Res. Mol. Brain Res. 35:47-57 (1996)]. JNK3 has been linked to neuronal apoptosis induced by kainic acid, indicating a role of JNK in the pathogenesis of glutamate neurotoxicity. In the adult human brain, JNK3 expression is localized to a subpopulation of pyramidal neurons in the CA1, CA4 and subiculum regions of the hippocampus and layers 3 and 5 of the neocortex [Mohit et al., supra]. The CA1 neurons of patients with acute hypoxia showed strong nuclear JNK3-immunoreactivity compared to minimal, diffuse cytoplasmic staining of the hippocampal neurons from brain tissues of normal patients [Zhang et al., supra]. Thus, JNK3 appears to be involved involved in hypoxic and ischemic damage of CA1 neurons in the hippocampus. In addition, JNK3 co-localizes immunochemically with neurons vulnerable in Alzheimer's disease [Mohit et al., supra]. Disruption of the JNK3 gene caused resistance of mice to the excitotoxic glutamate receptor agonist kainic acid, including the effects on seizure activity, AP-1 transcriptional activity and apoptosis of hippocampal neurons, indicating that the JNK3 signaling pathway is a critical component in the pathogenesis of glutamate neurotoxicity (Yang et al., Nature, 389:865-870 (1997)]. Based on these findings, JNK'signalling, especially that of JNK3, has been implicated in the areas of apoptosis-driven neurodegenerative diseases such as Alzheimer's Disease, Parkinson's Disease, ALS (Amyotrophic Lateral Sclerosis), epilepsy and seizures, Huntington's Disease, traumatic brain injuries, as well as ischemic and hemorrhaging stroke. There is a high unmet medical need to develop JNK specific inhibitors that are useful in treating the various conditions associated with JNK activation, especially considering the currently available, relatively inadequate treatment options for the majority of these conditions. Recently, we have described crystallizable complexes of JNK protein and adenosine monophosphate, including complexes comprising JNK3, in U.S. Provisional Application 60/084056, filed May 4, 1998. Such information hasbeen extremely useful in identifying and designing potential inhibitors of various members of the JNK family, which, in turn, have the described above therapeutic utility. Much work has been done to identify and develop drugs that inhibit MAPKs, such as p38 inhibitors. See, e.g., WO 98/27098 and WO 95/31451. However, to our knowledge, no MAPK inhibitors have been shown to be specifically selective for JNKs versus other related MAPKs. Accordingly, there is still a great need to develop potent inhibitors of JNKs, including JNK3 inhibitors, that are useful in treating various conditions associated with JNK activation. | <SOH> SUMMARY OF THE INVENTION <EOH>It has now been found that compounds of this invention and pharmaceutical compositions thereof are effective as inhibitors of c-Jun N-terminal kinases (JNK). These compounds have the general formula I: where R 1 is H, CONH 2 , T (n) —R, or T (n) —Ar 2 , n may be zero or one, and G, XYZ, and Q are as described below. Preferred compounds are those where the XYZ-containing ring is an isoxazole. Preferred G groups are optionally substituted phenyls and preferred Q are pyrimidine, pyridine or pyrazole rings. These compounds and pharmaceutical compositions thereof are useful for treating or preventing a variety of disorders, such as heart disease, immunodeficiency disorders, inflammatory diseases, allergic diseases, autoimmune diseases, destructive bone disorders such as osteoporosis, proliferative disorders, infectious diseases and viral diseases. The compositions are also useful in methods for preventing cell death and hyperplasia and therefore may be used to treat or prevent reperfusion/ischemia in stroke, heart attacks, and organ hypoxia. The compositions are also useful in methods for preventing thrombin-induced platelet aggregation. The compositions are especially useful for disorders such as chronic myelogenous leukemia (CML), rheumatoid arthritis, asthma, osteoarthritis, ischemia, cancer, liver disease including hepatic ischemia, heart disease such as myocardial infarction and congestive heart failure, pathologic immune conditions involving T cell activation and neurodegenerative disorders. | 20040213 | 20070130 | 20050203 | 57618.0 | 0 | RAO, DEEPAK R | INHIBITORS OF C-JUN N TERMINAL KINASES (JNK) AND OTHER PROTEIN KINASES | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,779,555 | ACCEPTED | Enhanced performance reactive composite projectiles | A reactive composite projectile includes a reactive composite material in a solid shape and an encasement material applied to and surrounding the solid shape for exerting compressive forces thereon. Additionally or alternatively, an elongate structure can be positioned in the solid shape. The elongate structure is made from a material having a mass density that is approximately 2 to 10 times the mass density of the reactive composite material. | 1. A method for enhancing launch and in-flight integrity of a reactive composite projectile, comprising the steps of: providing a reactive composite material in a solid shape; and encasing the solid shape in an encasement material that applies a compressive force to the solid shape. 2. A method according to claim 1 wherein said encasement material is tape and wherein said step of encasing comprises the steps of: applying a tensile force to said tape; and wrapping said tape about said solid shape while said tensile force is being applied. 3. A method according to claim 2 wherein said tape is made from a material that chemically reacts with the reactive composite material when the solid shape strikes a target. 4. A method according to claim 2 wherein said tape is made from a material that is inert with respect to the reactive composite material when the solid shape strikes a target. 5. A method according to claim 1 wherein said encasement material is a polymeric material and said step of encasing comprises the steps of: coating the solid shape with a liquified form of the polymeric material; and curing the liquified form of the polymeric material so-coated on the solid shape wherein the polymeric material shrinks to thereby apply said compressive force to the solid shape. 6. A method according to claim 1 wherein said encasement material is a polymeric material and said step of encasing comprises the steps of: extruding a flexible solid form of the polymeric material over the solid shape; and curing the flexible solid form of the polymeric material so-extruded over the solid shape wherein the polymeric material shrinks to thereby apply said compressive force to the solid shape. 7. A reactive composite projectile, comprising: a reactive composite material in a solid shape; and an encasement material applied to and surrounding said solid shape for exerting compressive forces thereon. 8. A reactive composite projectile as in claim 7 wherein said encasement material comprises tape wrapped under tension onto said solid shape. 9. A reactive composite projectile as in claim 8 wherein said tape is made from a material that chemically reacts with said reactive composite material when the solid shape strikes a target. 10. A reactive composite projectile as in claim 8 wherein said tape is made from a material that is inert with respect to said reactive composite material when the solid shape strikes a target. 11. A reactive composite projectile as in claim 7 wherein said encasement material is a polymeric material shrink cured onto said solid shape. 12. A reactive composite projectile as in claim 7 further comprising an elongate structure positioned in said solid shape, said elongate structure made from a material having a mass density that is approximately 2 to 10 times said mass density of said reactive composite material. 13. A reactive composite projectile as in claim 12 wherein said elongate structure comprises a plurality of fins extending radially outward from an elongate core. 14. A reactive composite projectile as in claim 12 wherein said elongate structure comprises a one-piece structure that defines a plurality of elongate fins extending radially outward from an elongate core. 15. A reactive composite projectile as in claim 12 wherein said elongate structure comprises an assembly that, when assembled, defines a plurality of elongate fins extending radially outward from an elongate core. 16. A reactive composite projectile as in claim 12 wherein said elongate structure comprises an externally threaded rod. 17. A reactive composite projectile as in claim 12 wherein said elongate structure comprises a plurality of elongate rods. 18. A reactive composite projectile as in claim 17 wherein said plurality of elongate rods are bundled together. 19. A reactive composite projectile as in claim 12 wherein said elongate structure is made from a material selected from the group consisting of metals and ceramics. 20. A reactive composite projectile as in claim 7 wherein said solid shape comprises a cylinder. 21. A reactive composite projectile as in claim 7 wherein said solid shape comprises a sphere. 22. A reactive composite projectile as in claim 7 wherein said solid shape comprises a cube. 23. A reactive composite projectile, comprising: a reactive composite material in a solid shape, said reactive composite material having a mass density; and an elongate structure positioned in said solid shape, said elongate structure made from a material having a mass density that is approximately 2 to 10 times said mass density of said reactive composite material. 24. A reactive composite projectile as in claim 23 wherein said elongate structure comprises a plurality of fins extending radially outward from an elongate core. 25. A reactive composite projectile as in claim 23 wherein said elongate structure comprises a one-piece structure that defines a plurality of elongate fins extending radially outward from an elongate core. 26. A reactive composite projectile as in claim 23 wherein said elongate structure comprises an assembly that, when assembled, defines a plurality of elongate fins extending radially outward from an elongate core. 27. A reactive composite projectile as in claim 23 wherein said elongate structure comprises an externally threaded rod. 28. A reactive composite projectile as in claim 23 wherein said elongate structure comprises a plurality of elongate rods. 29. A reactive composite projectile as in claim 28 wherein said plurality of elongate rods are bundled together. 30. A reactive composite projectile as in claim 23 wherein said solid shape comprises a cylinder. 31. A reactive composite projectile as in claim 23 wherein said solid shape comprises a sphere. 32. A reactive composite projectile as in claim 23 wherein said solid shape comprises a cube. 33. A reactive composite projectile as in claim 23 wherein said elongate structure is made from a material selected from the group consisting of metals and ceramics. 34. A reactive composite projectile, comprising: a reactive composite material in a solid shape, said reactive composite material having a mass density; and an elongate structure positioned in a central portion of said solid shape, said elongate structure made from a material having a mass density that is approximately 2 to 10 times said mass density of said reactive composite material, said elongate structure having an elongate core with fin-like protuberances extending radially outward from said elongate core into said solid shape. 35. A reactive composite projectile as in claim 34 wherein said elongate structure comprises a one-piece structure. 36. A reactive composite projectile as in claim 34 wherein said elongate structure comprises a multiple-piece assembly. 37. A reactive composite projectile as in claim 34 wherein said fin-like protuberances extend longitudinally along said elongate core. 38. A reactive composite projectile as in claim 34 wherein said fin-like protuberances comprise threads. 39. A reactive composite projectile as in claim 34 wherein said solid shape comprises a cylinder. 40. A reactive composite projectile as in claim 34 wherein said solid shape comprises a sphere. 41. A reactive composite projectile as in claim 34 wherein said solid shape comprises a cube. 42. A reactive composite projectile as in claim 34 further comprising an encasement material applied to and surrounding said solid shape for exerting compressive forces thereon. 43. A reactive composite projectile as in claim 42 wherein said encasement material comprises tape wrapped under tension onto said solid shape. 44. A reactive composite projectile as in claim 43 wherein said tape is made from a material that chemically reacts with said reactive composite material when the solid shape strikes a target. 45. A reactive composite projectile as in claim 43 wherein said tape is made from a material that is inert with respect to said reactive composite material when the solid shape strikes a target. 46. A reactive composite projectile as in claim 42 wherein said encasement material is a polymeric material shrink cured onto said solid shape. 47. A reactive composite projectile as in claim 34 wherein said elongate structure is made from a material selected from the group consisting of metals and ceramics. | ORIGIN OF THE INVENTION The invention described herein was made in the performance of official duties by an employee of the Department of the Navy and may be manufactured, used, licensed by or for the Government for any governmental purpose without payment of any royalties thereon. FIELD OF THE INVENTION The invention relates generally to reactive materials, and more particularly to reactive material projectiles encased to enhance launch/in-flight integrity and aerodynamics, and/or having an insert that enhances performance in terms of target penetration and energy release. BACKGROUND OF THE INVENTION Reactive composite materials show promise for use as weapon projectiles designed to defeat a “protected” target. Such protected targets can be targets protected by a building structure or armor. Upon striking such a protected target, the energy of the impact serves as a catalyst that initiates a chemical reaction of the reactive composite material. This reaction releases a large amount of energy. As is known in the art, reactive composite materials generally include particles or powdered forms of one or more reactive metals, one or more oxidizers, and typically some binder materials. The reactive metals can include aluminum, beryllium, hafnium, lithium, magnesium, thorium, titanium, uranium, zirconium, as well as combinations, alloys and hydrides thereof. The oxidizers can include ammonium perchlorate, chlorates, lithium perchlorate, magnesium perchlorate, peroxides, potassium perchlorate, and combinations thereof. The binder materials typically include epoxy resins and polymeric materials. The problems associated with reactive composite projectiles are two-fold. First, the projectiles must be launched and propelled at high speeds in order to penetrate a projected target. However, reactive composite materials have relatively low mechanical strength. This limits launch and in-flight speeds for such projectiles lest they break up at launch or during flight making them aerodynamically unstable and reducing their effectiveness at target impact. Second, the relatively low strength and mass density of reactive composite projectiles limits their target penetration effectiveness on targets having thicker “skins”. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to enhance the performance of a reactive composite projectile in terms of launch and in-flight integrity and/or target penetration and subsequent energy release. Other objects and advantages of the present invention will become more obvious hereinafter in the specification and drawings. In accordance with the present invention, a reactive composite projectile includes a reactive composite material in a solid shape and an encasement material applied to and surrounding the solid shape for exerting compressive forces thereon. Additionally or alternatively, an elongate structure can be positioned in the solid shape. The elongate structure is made from a material having a mass density that is approximately 2 to 10 times the mass density of the reactive composite material. In general, the encasement material enhances projectile performance in terms of launch/in-flight integrity and while the elongate structure enhances projectile performance in terms of penetration/energy release. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a reactive composite projectile encased in a compressive material in accordance with a first aspect of the present invention; FIG. 2 is a partial cut-away perspective view of a tape-wrapped encasing material embodiment of the reactive composite projectile of the present invention; FIG. 3 is a partial cut-away perspective view of a shrink-cured encasing material embodiment of the reactive composite projectile of the present invention; FIG. 4 is a perspective view of a reactive composite projectile that incorporates one embodiment of an elongate structure therein in accordance with a second aspect of the present invention; FIG. 5 is a perspective view of a second embodiment of an elongate structure; FIG. 6 is a perspective view of a third embodiment of an elongate structure; FIG. 7 is a perspective view of a fourth embodiment of an elongate structure; FIG. 8 is a perspective view of a fifth embodiment of an elongate structure; and FIG. 9 is a cross-sectional view of a reactive composite projectile that is encased in a compressive material and that incorporates an elongate structure therein in accordance with a third aspect of the present invention. DETAILED DESCRIPTION OF THE INVENTION Prior to describing the present invention, two terms used in the following description will first be defined. The first of these terms is “reactive composite material” and the second of these terms is “projectile”. As used herein, the term “reactive composite material” refers to any composite material having constituent components that will react together to release energy when subjected to a high force of impact. As is known in the art, typical reactive composite materials include one or more metals, one or more oxidizers and binder material. The choice of reactive composite material is not a limitation of the present invention. A typical example is aluminum polytetrafluoroethylene (Al-PTFE). The term “projectile” as used herein refers to any body that is projected or impelled forward through a medium (e.g., air). The shape of the body is not a limitation of the present invention although regular body shapes (e.g., cylinders, spheres, cubes) will typically be used. The body can be projected or launched individually or as part of a group of such bodies to include breakable arrays of interconnected projectiles. The projection force can be delivered by a mechanism (e.g., a gun, launcher, etc.) or can be delivered by explosive fragmentation of a delivery vehicle (e.g., an airborne fragmenting projectile that disperses smaller projectile bodies or fragments over an area). The present invention can be used to enhance the performance of reactive composite projectiles in several ways. In one aspect of the present invention, launch and in-flight integrity of the projectiles is enhanced. In a second aspect of the present invention, the projectile's target penetration and subsequent energy release performance is enhanced. Further, a third aspect of the present invention combines the features of the first two aspects of the invention to improve the projectiles' launch/in-flight integrity and the projectile's penetration/energy release performance. Referring now to the drawings, and more particularly to FIG. 1, a reactive composite projectile in accordance with a first aspect of the present invention is shown and is referenced generally by numeral 10. Projectile 10 includes a reactive composite material 12 in the form of a solid shape. As mentioned above, the particular constituent elements and shape of material 12 are not limitations of the present invention. Encasing material 12 is an encasing material 14 that applies compressive forces (indicated by arrows 16) to material 12 on all sides thereof. Encasing material 14 and the resulting compressive forces 16 enhance the launch and in-flight integrity of projectile 10. Specifically, after projectile is launched or otherwise propelled through a medium such as air, material 12 is subjected to wave loading that includes waves of tension that pass through material 12. Without encasing material 14, these waves of tension would cause spalling and separation of material 12 at the edges of the shape thereof. However, the compressive state of material 12 brought about by encasing material 14 suppresses the waves of tension brought on by the launching of projectile 10. In addition, high-speed flight of an unencased material 12 can cause spalling and separation of material 12 at the outer edges thereof. However, encasing material 14 prevents such in-flight spalling and separation to insure the integrity of material 12 throughout its flight. Thus, encasing material 14 will improve the launch and in-flight integrity of reactive composite material 12. A variety of materials for encasing material 14 as well as the methods of applying same to material 12 can be utilized without departing from the scope of the present invention. For example, encasing material 14 can be chosen to be either inert or reactive with material 12 when projectile 10 impacts a target. If inert with respect to material 12, encasing material 14 just provides mechanical integrity for material 12. If reactive with respect to material 12, encasing material 14 provides mechanical integrity for material 12 and can also be used to enhance and/or control the reaction of material 12 upon target impact. Encasing material 14 can be applied to material 12 in a variety of ways provided compressive forces 16 are applied to material 12 by encasing material 14. For example, as illustrated in FIG. 2, encasing material 14 can be in the form of a tape 14A (e.g., aluminum, MYLAR, TEFLON, etc.) that is completely wrapped about material 12. Such wrapping would be accomplished by applying a tensioning force to tape 14A as it is being wrapped about material 12 so that tape 14A applies the afore-described compressive forces 16 to material 12. If encasing material 14 must present a seamless surface, material 14 can be applied to material 12 by a shrink curing process that causes compressive forces 16 to be applied as material 14 shrinks and cures. For example, encasing material 14 could be a polymeric material (e.g., polypropylene, epoxy, etc.) applied as a liquid to material 12 and then cured. Another option is for encasing material 14 to be a polymeric material (e.g., polyvinylchloride, polyethylene, polypropylene, etc.) extruded as a flexible solid about material 12 and then cured. In either case, a seamless construction of encasing material 14 results as shown in FIG. 3. The second aspect of the present invention enhances a reactive composite projectile's target penetration and energy release performance. Several exemplary embodiments of such reactive composite projectiles will be described herein with the aid of FIGS. 4-8 where, in each of the embodiments, reactive composite material 12 is in the form of a solid cylinder that is illustrated using phantom lines. As mentioned above, it is to be understood that the cylindrical shape of material 12 is not a limitation of the present invention. In general, each of the projectiles shown in FIGS. 4-8 have an elongate structure positioned therein that is made from a material having a mass density that is approximately 2-10 times greater than the mass density of material 12. The increased mass density improves the penetration performance of the projectile. For flight stability, the elongate structure would typically be positioned in a central portion of material 12. For applications requiring substantial penetration and energy release performance, the elongate structure is made heavier and can extend the length of material 12. For applications requiring a greater level of flight stability for the projectile, the elongate structure might extend only partially through material 12 thereby providing a weighted end. Materials used for the elongate structure can include metals such as steel, tungsten, depleted uranium or other high-mass density metals/alloys. The elongate structure could also be made from ceramics such as alumina or ceramic composites such as silicon carbide, tungsten carbide, etc. Since ceramic materials often possess greater impact strength than many metals, such ceramics may be the better choice of material where penetration performance of the projectile is of concern. The elongate structure can be realized in a variety of ways without departing from the scope of the present invention. For example, in each of FIGS. 4-6, the elongate structure has (i) a central elongate core that extends through material 12, and (ii) fins or fin-like elements or protuberances extending radially out into material 12 from the core. More specifically, FIG. 4 illustrates an elongate structure 20 having a central core 22 with fins 24 (e.g., four are shown) aligned with core 22 and extending radially outward therefrom into material 12. More or fewer fins 24 can be used. Structure 20 can be made from a single piece of material or could be made from multiple pieces that are assembled together. Structure 20 can extend the length of material 12 (as shown) or only partially therethrough as described above. FIG. 5 illustrates an elongate structure 30 having a central core 32 with fins 34 that are aligned with core 32 and extend radially out into material 12. The height h of each fin 34 increases along the length of material 12 such that structure 30 is tapered along its length thereby providing a greater weight at one end of the projectile. FIG. 6 illustrates an elongate structure 40 having a central core 42 with fins 44 running helically around core 42 and extending radially outward and into material 12. Thus, structure 40 is essentially a threaded rod. Accordingly, if elongate structure 40 is a bolt, the head 46 thereof can be positioned at one end of material 12 as shown to weight the end and form an impact head for the projectile. Also note that structure 40 could be an assembly made from multiple pieces such as two elongate halves. The elongate structure in the present invention could also be realized by a plurality of smooth-surface or textured-surface rods 50 positioned in material 12. Rods 50 can be separated from one another as shown in FIG. 7 or could be bundled together as shown in FIG. 8. Furthermore, each of rods 50 could have elongate or helical fins extending radially outward therefrom as in each of the elongate structures depicted in FIGS. 4-6. Each of the above-described embodiments will function in essentially the same fashion upon impact with a target. That is, upon impact, the additional mass density provided by the elongate structure enhances penetration into the target's skin. Then as the elongate structure begins to bed, buckle and/or break, the failing structure causes indentation and break up of material 12 from within. The indentations, break up and shear deformation of material 12 (from within material 12) serve as sources of chemical reaction initiation of material 12. By using fins or multiple rods, the present invention provides a large surface area of contact within material 12 to thereby reduce reaction time for material 12 which, in turn, makes for more intense shear and a more intense chemical reaction of material 12 as the elongate structure bends, buckles and/or breaks. The third aspect of the present invention involves combining the features of the first two aspects of the present invention. For example, FIG. 9 illustrates reactive composite projectile 100 having reactive composite material 12 that (i) is encased by encasing material 14 (to apply compressive forces 16 thereto), and (ii) has an elongate structure such as structure 20 (having fins 24) positioned therein. Thus, projectile 100 will have enhanced performance in terms of both launch/in-flight integrity/aerodynamics and penetration/energy release. Although the invention has been described relative to a specific embodiment thereof, there are numerous variations and modifications that will be readily apparent to those skilled in the art in light of the above teachings. For example, encasement of the reactive composite material could also make use of mechanical end caps to weight the projectile for flight stability. The elongate structure positioned in the reactive composite material could combine the use of elongate fins and helical fins (or threads). It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described. | <SOH> BACKGROUND OF THE INVENTION <EOH>Reactive composite materials show promise for use as weapon projectiles designed to defeat a “protected” target. Such protected targets can be targets protected by a building structure or armor. Upon striking such a protected target, the energy of the impact serves as a catalyst that initiates a chemical reaction of the reactive composite material. This reaction releases a large amount of energy. As is known in the art, reactive composite materials generally include particles or powdered forms of one or more reactive metals, one or more oxidizers, and typically some binder materials. The reactive metals can include aluminum, beryllium, hafnium, lithium, magnesium, thorium, titanium, uranium, zirconium, as well as combinations, alloys and hydrides thereof. The oxidizers can include ammonium perchlorate, chlorates, lithium perchlorate, magnesium perchlorate, peroxides, potassium perchlorate, and combinations thereof. The binder materials typically include epoxy resins and polymeric materials. The problems associated with reactive composite projectiles are two-fold. First, the projectiles must be launched and propelled at high speeds in order to penetrate a projected target. However, reactive composite materials have relatively low mechanical strength. This limits launch and in-flight speeds for such projectiles lest they break up at launch or during flight making them aerodynamically unstable and reducing their effectiveness at target impact. Second, the relatively low strength and mass density of reactive composite projectiles limits their target penetration effectiveness on targets having thicker “skins”. | <SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, it is an object of the present invention to enhance the performance of a reactive composite projectile in terms of launch and in-flight integrity and/or target penetration and subsequent energy release. Other objects and advantages of the present invention will become more obvious hereinafter in the specification and drawings. In accordance with the present invention, a reactive composite projectile includes a reactive composite material in a solid shape and an encasement material applied to and surrounding the solid shape for exerting compressive forces thereon. Additionally or alternatively, an elongate structure can be positioned in the solid shape. The elongate structure is made from a material having a mass density that is approximately 2 to 10 times the mass density of the reactive composite material. In general, the encasement material enhances projectile performance in terms of launch/in-flight integrity and while the elongate structure enhances projectile performance in terms of penetration/energy release. | 20040210 | 20070320 | 20050825 | 80369.0 | 0 | CHAMBERS, TROY | ENHANCED PERFORMANCE REACTIVE COMPOSITE PROJECTILES | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,780,029 | ACCEPTED | Previewing points of interest in navigation system | A vehicle navigation system provides information relating to a list of intersections or other points of interest located ahead of a vehicle relative to a heading vector of the vehicle. The vehicle navigation system uses information about the current location of the vehicle and the heading vector in connection with a navigation database to identify a list of the intersections or other points of interest along the current street. The vehicle navigation system presents this information to an occupant of the vehicle. As the vehicle progresses and makes turn maneuvers, the navigation system updates the list of intersections or other points of interest that the vehicle is approaching. The occupant can receive information regarding points of interest without needing to enter a planned destination beforehand. In addition, the occupant can determine the location of the vehicle relative to the surrounding area without the clutter of irrelevant map details. | 1. A method to communicate to an occupant of a vehicle information relating to a location of the vehicle in the absence of predetermined route information, the method comprising: determining the location of the vehicle; determining a heading vector associated with the vehicle; identifying a point of interest as a function of the location of the vehicle and the heading vector associated with the vehicle; and communicating the point of interest to the occupant of the vehicle. 2. The method of claim 1, wherein communicating the point of interest to the occupant of the vehicle comprises displaying a graphic representation of the point of interest and a graphic representation of the vehicle using a display device. 3. The method of claim 1, wherein communicating the point of interest to the occupant of the vehicle comprises generating an audible indicator of the point of interest using an audio device. 4. The method of claim 1, wherein determining the location of the vehicle comprises identifying a street on which the vehicle is located. 5. The method of claim 4, wherein the point of interest is an intersection, and further comprising identifying the intersection as a function of the location of the vehicle, the heading vector associated with the vehicle, and a list of intersections along the street. 6. The method of claim 1, further comprising: identifying a plurality of points of interest as a function of the location of the vehicle and the heading vector associated with the vehicle; and communicating at least one of the points of interest to the occupant of the vehicle. 7. The method of claim 6, further comprising communicating the at least one of the points of interest to the occupant of the vehicle as a sequence of successive points of interest. 8. The method of claim 7, further comprising communicating the successive points of interest in response to input received from the occupant of the vehicle. 9. The method of claim 7, further comprising communicating the successive points of interest in response to movement of the vehicle. 10. A navigation system for use in a vehicle, the navigation system comprising: a global positioning system (GPS) receiver configured to determine a location of the vehicle; a data retrieval device configured to retrieve, from a data storage medium, navigation data representing a plurality of points of interest; and a processor-based subsystem operatively coupled to the GPS receiver and to the data retrieval device and configured to determine a heading vector associated with the vehicle, receive the navigation data from the data retrieval device, select a point of interest from the plurality of points of interest as a function of the location of the vehicle and the heading vector associated with the vehicle, communicate the point of interest to an occupant of the vehicle. 11. The navigation system of claim 10, further comprising a display device operatively coupled to the processor-based subsystem, wherein the processor-based subsystem is configured to cause the display device to display a graphic representation of the point of interest and a graphic representation of the vehicle. 12. The navigation system of claim 10, further comprising an audio output device operatively coupled to the processor-based system, wherein the processor-based subsystem is configured to cause the audio output device to generate an audible indicator of the point of interest. 13. The navigation system of claim 12, further comprising a speech module operatively coupled to the processor-based system and to the audio output device and configured to generate a speech indicator of the point of interest. 14. The navigation system of claim 10, wherein the processor-based system is further configured to determine the location of the vehicle comprises identifying a street on which the vehicle is located. 15. The navigation system of claim 14, wherein the point of interest is an intersection, and wherein the processor-based system is further configured to identify the intersection as a function of the location of the vehicle, the heading vector associated with the vehicle, and a list of intersections along the street. 16. The navigation system of claim 10, wherein the processor-based system is further configured to: identify a plurality of points of interest as a function of the location of the vehicle and the heading vector associated with the vehicle; and communicate at least one of the points of interest to the occupant of the vehicle. 17. The navigation system of claim 16, wherein the processor-based system is further configured to communicate the at least one of the points of interest to the occupant of the vehicle as a sequence of successive points of interest. 18. The navigation system of claim 17, further comprising an input device operatively coupled to the processor-based system and configured to receive input from the occupant, wherein the processor-based system is further configured to communicate the successive points of interest in response to input received from the occupant of the vehicle. 19. The navigation system of claim 18, wherein the input device comprises at least one of a keypad and an audio input device. 20. The navigation system of claim 17, wherein the processor-based system is further configured to communicate the successive points of interest in response to movement of the vehicle. 21. The navigation system of claim 10, wherein the data retrieval device comprises at least one of a memory device, an optical retrieval device, and a magnetic retrieval device. 22. A processor-readable medium containing processor-executable instructions that, when executed by a processor-based system in a vehicle, cause the processor-based system to: determine a location of the vehicle and a heading vector associated with the vehicle; identify a point of interest as a function of the location of the vehicle and the heading vector associated with the vehicle; and communicate the point of interest to the occupant of the vehicle. 23. The processor-readable medium of claim 22, wherein the processor-executable instructions cause the processor-based system to display a graphic representation of the point of interest and a graphic representation of the vehicle using a display device. 24. The processor-readable medium of claim 22, wherein the processor-executable instructions cause the processor-based system to generate an audible indicator of the point of interest using an audio device. 25. The processor-readable medium of claim 22, wherein the processor-executable instructions cause the processor-based system to identify a street on which the vehicle is located. 26. The processor-readable medium of claim 25, wherein the point of interest is an intersection, and wherein the processor-executable instructions cause the processor-based system to identify the intersection as a function of the location of the vehicle, the heading vector associated with the vehicle, and a list of intersections along the street. 27. The processor-readable medium of claim 22, wherein the processor-executable instructions cause the processor-based system to: identify a plurality of points of interest as a function of the location of the vehicle and the heading vector associated with the vehicle; and communicate at least one of the points of interest to the occupant of the vehicle. 28. The processor-readable medium of claim 27, wherein the processor-executable instructions cause the processor-based system to communicate the at least one of the points of interest to the occupant of the vehicle as a sequence of successive points of interest. 29. The processor-readable medium of claim 28, wherein the processor-executable instructions cause the processor-based system to communicate the successive points of interest in response to input received from the occupant of the vehicle. 30. The processor-readable medium of claim 28, wherein the processor-executable instructions cause the processor-based system to communicate the successive points of interest in response to movement of the vehicle. | TECHNICAL FIELD The disclosure relates generally to vehicle navigation systems. More particularly, the disclosure relates to graphic user interfaces for use in connection with vehicle navigation systems. BACKGROUND An increasing number of vehicles are equipped with on-board navigation systems that display the position of the vehicle and surrounding streets, intersections, and other points of interest. Some navigation systems allow the driver to input or program a route. The navigation system then displays the position of the vehicle along the route. In addition to displaying the vehicle position along a route, a navigation system can typically also display the vehicle location even when no route is programmed. In this case, the navigation system does not have a route that provides a context for the display. Some navigation systems that incorporate relatively large color display screens can display the vehicle location in the context of a detailed map reference of the surrounding area when no route is programmed. Other navigation systems, however, incorporate smaller display screens. Rendering the vehicle location is difficult because the display screen is too small to display a map reference that is both sufficiently detailed and sufficiently free of clutter to be useful. For example, the map reference may be rendered at a sufficient level of detail, but contain so much clutter as to be unreadable from the position of the driver. Even with a relatively large display screen, some users may find a detailed map reference too cluttered to be useful. On the other hand, the map reference may be sufficiently free of clutter to allow the driver to locate the visual representation of the car, but lack detailed information as to surrounding streets. In either case, the driver does not significantly benefit from the map reference. SUMMARY OF THE DISCLOSURE According to various example implementations, a vehicle navigation system provides an occupant of a vehicle with information relating to a list of intersections or other points of interest located ahead of the vehicle relative to the current direction of travel of the vehicle. The vehicle navigation system uses information about the current location of the vehicle and a heading vector that indicates the current direction of travel in connection with a navigation database to identify a list of the intersections or other points of interest along the current street. The vehicle navigation system presents this information to the occupant. As the vehicle progresses and makes turn maneuvers, the navigation system updates the list of intersections or other points of interest that the vehicle is approaching. In one implementation, information relating to a location of a vehicle is communicated to an occupant of the vehicle in the absence of predetermined route information by detemnining the location of the vehicle and a heading vector associated with the vehicle. A point of interest is identified as a function of the location of the vehicle and the heading vector associated with the vehicle. This point of interest is then communicated to the occupant of the vehicle. Another implementation is directed to a navigation system for use in a vehicle. A global positioning system (GPS) receiver is configured to determine a location of the vehicle. A data retrieval device is configured to retrieve, from a data storage medium, navigation data representing a plurality of points of interest. A processor-based subsystem is operatively coupled to the GPS receiver and to the data retrieval device. The processor-based system is configured to determine a heading vector associated with the vehicle and to receive the navigation data from the data retrieval device. The processor-based system is further configured to select a point of interest from the plurality of points of interest as a function of the location of the vehicle and the heading vector associated with the vehicle and to communicate the point of interest to an occupant of the vehicle. In still another embodiment, a processor-readable medium contains processor-executable instructions. When executed by a processor-based system in a vehicle, the processor-executable instructions cause the processor-based system to determine a location of the vehicle and a heading vector associated with the vehicle. The processor-based system then identifies a point of interest as a function of the location of the vehicle and the heading vector associated with the vehicle and communicates the point of interest to the occupant of the vehicle. Various implementations may provide certain advantages. The navigation system communicates information regarding upcoming intersections and points of interest based on the current location and heading vector of the vehicle. As a result, the occupant can receive information regarding points of interest without needing to enter a planned destination beforehand. Even when a destination is entered, the occupant can benefit from being able to determine the location of the vehicle relative to the surrounding area without the clutter of irrelevant map details. Additional advantages and features will become apparent from the following description and the claims that follow, considered in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram depicting a vehicle navigation system according to an embodiment. FIG. 2 is a flow diagram illustrating a method of communicating information relating to a location of a vehicle according to another embodiment. FIG. 3 illustrates an example graphic user interface (GUI) that may be presented to the user. FIG. 4 depicts another example GUI that may be presented to the user. DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS A vehicle navigation system provides an occupant of a vehicle with information relating to a list of intersections or other points of interest located ahead of the vehicle relative to the current direction of travel of the vehicle. Using a global positioning system (GPS), for example, the vehicle navigation system obtains information about the current location of the vehicle and a heading vector that indicates the current direction of travel. The vehicle navigation system uses this information in connection with a navigation database to identify a list of the intersections or other points of interest along the current street. Based on the current location of the vehicle and the heading vector, the vehicle navigation system determines which intersections or other points of interest the vehicle is approaching and presents this information to the occupant. As the vehicle progresses along the street and makes turn maneuvers, the navigation system updates the list of intersections or other points of interest that the vehicle is approaching. Because the navigation system presents information to the occupant based on the current location and heading vector of the vehicle rather than on pre-programmed route information, the occupant can receive information regarding points of interest without needing to enter a planned destination beforehand. Communication of information to the occupant is enhanced, particularly in relatively inexpensive vehicle navigation systems having small display screens. Such systems are better able to provide the occupant with enough information to discern nearby points of interest without cluttering the screen with so much information that the display becomes unusable by the occupant. Navigation systems having larger screens can also benefit from reduced clutter. Various embodiments are described as displaying information without reference to a predetermined route. It will be appreciated by those of skill in the art, however, that the methods and apparatuses described herein can also be used to display information when a destination is entered. When a destination is entered, the occupant can determine the location of the vehicle relative to the surrounding area without the clutter of irrelevant map details. The following description of various embodiments implemented in a vehicle navigation system is to be construed by way of illustration rather than limitation. This description is not intended to limit the invention or its applications or uses. For example, while various embodiments are described as being implemented in a vehicle navigation system, it will be appreciated that the principles described herein may be applicable to navigation systems operable in other environments. In the following description, numerous specific details are set forth in order to provide a thorough understanding of various embodiments. It will be apparent to one skilled in the art that the present invention may be practiced without some or all of these specific details. In other instances, well known components and process steps have not been described in detail in order to avoid unnecessarily obscuring the present invention. Various embodiments may be described in the general context of processor-executable instructions, such as program modules, being executed by a processor. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types. In addition, some embodiments may also be practiced in distributed processing environments in which tasks are performed by remote processing devices that are linked through a communications network or other data transmission medium. In a distributed processing environment, program modules and other data may be located in both local and remote storage media, including memory storage devices. Referring now to the drawings, FIG. 1 illustrates a vehicle navigation system 10. The vehicle navigation system 10 includes a processor-based system comprising a processor 12 configured to execute a number of software modules, including a vehicle position module 14, a navigation server module 16, and a user interface module 18. As described below, the processor 12 may interface with a user 20 via one or more input and output devices controlled by the user interface module 18. The user 20 can be the driver of the vehicle or, alternatively, a passenger. The processor 12 is typically configured to operate with one or more types of processor readable media. Processor readable media can be any available media that can be accessed by the processor 12 and includes both volatile and nonvolatile media, removable and non-removable media. By way of example, and not limitation, processor readable media may include storage media and communication media. Storage media includes both volatile and nonvolatile, removable and nonremovable media implemented in any method or technology for storage of information such as processor-readable instructions, data structures, program modules, or other data. Storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile discs (DVDs) or other optical disc storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and that can be accessed by the processor 12. Communication media typically embodies processor-readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared, and other wireless media. Combinations of any of the above are also intended to be included within the scope of processor-readable media. The vehicle position module 14 determines the location of the vehicle, for example, by obtaining data from a GPS module 22. Alternatively, the vehicle position module 14 may determine the location of the vehicle in another way, such as by measuring the distance and direction traveled from a known reference point. In addition to the location of the vehicle, the vehicle position module 14 determines a heading vector, or direction of travel, of the vehicle. The vehicle position module 14 may determine the heading vector using any of a variety of conventional techniques. The vehicle position module 14 provides the location and heading vector information to the navigation server module 16. The navigation server module 16 uses this information in combination with information relating to points of interest, such as intersections, to identify one or more points of interest that the vehicle is approaching. This information may be contained in a database 24. The database 24 may be stored in any of a variety of processor-readable media, including, for example, optical discs including CD-ROMs and DVD-ROMs, memory cards, and the like. When the navigation server module 16 has identified one or more points of interest that the vehicle is approaching, the navigation server module 16 provides this information to the user 20 using one or more output devices, such as a speaker 26 or a display screen 28, controlled via the user interface module 18. The speaker 26 may be part of a vehicle audio system or a standalone speaker. The display screen 28 is typically part of a vehicle information system, but may be implemented as a standalone display screen. In the embodiment shown in FIG. 1, the navigation server module 16 provides the information regarding points of interest that the vehicle is approaching to a navigation client module 30. The navigation client module 30 in turn generates graphic output, audio output, or both. A display driver 32 processes the graphic output and renders the graphic output on the display screen 28. The audio output may include speech, sound effects, or both. Speech output may be generated, for example, as a synthesized rendering of a name of an intersection or other point of interest by a text-to-speech module 34. Sound effects may include, for example, chimes or other sounds to alert the user 20 of certain types of points of interest, such as intersections or restaurants. Both speech and sound effects are processed by an audio driver 36, which renders the audio output using the speaker 26. In addition to providing output to the user 20, the user interface module 18 can also receive input from the user 20. For example, the user 20 may advance through the list of upcoming points of interest using a keypad 38 or other input device. An input interface 40 provides the input to the navigation client module 30, which makes appropriate changes to the display or audio output according to the input. Further, in some embodiments, the user 20 may interact with the vehicle navigation system 10 by voice commands spoken into a microphone 42. A voice recognition module 44 converts the voice commands to text or another format that can be processed by the vehicle navigation system 10. FIG. 2 is a flow diagram illustrating an example method executed by the processor 12 of FIG. 1 to communicate to the user 20 information relating to intersections or other points of interest that the vehicle is approaching. The processor 12 may communicate this information when the user 20 has not entered a destination or other route information. Further, the processor 12 may also communicate this information when the user 20 has entered a destination or other route information. The vehicle position module 14 obtains from the GPS module 22 information relating to the position of the vehicle, including, for example, latitude and longitude readings (50). Based on the latitude and longitude readings and information received in the navigation server module 16 from the database 24, the processor 12 determines the street on which the vehicle is currently located (52). In addition to the location of the vehicle, the vehicle position module 14 determines a heading vector (54) that indicates the direction in which the vehicle is traveling. The vehicle position module 14 may determine the heading vector using any of a variety of conventional techniques. Based on the location and heading vector of the vehicle, the processor 12 identifies one or more intersections or other points of interest that the vehicle is approaching (56). In some implementations, for example, the intersections or other points of interest are associated in the database 24 with location information, e.g., longitude and latitude coordinates or street identifiers. For instance, the database 24 may contain a list of street names, each of which is associated with a list of intersections located on the corresponding street. The navigation server module 16 executing on the processor 12 compares the location information associated with the intersections or other points of interest with the location and heading vector of the vehicle. In this way, the navigation server module 16 determines which intersections or other points of interest are located in the vicinity of the vehicle and in the current direction of travel of the vehicle. The navigation server module 16 optionally also identifies which intersections or other points of interest are located in the vicinity of and behind the vehicle, i.e., points of interest that the vehicle has passed. The user interface module 18 then communicates the information (58) relating to nearby intersections or other points of interest to the user 20 via one or more output devices, including, but not limited to, the speaker 26, the display screen 28, or both. For example, the user interface module 18 may display graphic representations of the point of interest and of the vehicle using the display screen 28. These graphic representations may include a detailed view of an upcoming intersection. The user interface module 18 may display text in addition to or instead of the graphic representations. The text may include, for example, names of and distances to intersecting streets. Further, the user interface module 18 may generate an audible indicator of the point of interest using the speaker 26, either instead of or in addition to providing a visual indicator. This audible indicator may include speech, sound effects, or both. If the street on which the vehicle is located contains multiple intersections or other points of interest, the user interface module 18 may communicate some or all of these points of interest to the user 20. For example, the user interface module 18 may inform the user 20 of all upcoming intersections, but omit information relating to other types of points of interest. The user interface module 18 may communicate multiple points of interest as a sequence of successive points of interest. In some implementations, the user interface module 18 advances through the sequence in response to input received from the user 20 via an input device, such as the keypad 38 or the microphone 42. The user interface module 18 may also advance through the sequence in response to movement of the vehicle, for example, as a function of the distance of the vehicle from a point of interest or as a function of the speed of the vehicle. To ensure that the information communicated to the user 20 relates to the current position of the vehicle, the processor 12 periodically obtains updated information relating to the location and heading vector of the vehicle (50). In this way, as the vehicle progresses and makes turn maneuvers, the vehicle navigation system 10 looks ahead to update upcoming intersection information to the user 20. As a result, the user 20 can look ahead in the direction of travel without entering a planned destination and gain a sense of the vehicle location relative to intersections and other points of interest. FIG. 3 illustrates an example graphic user interface (GUI) 70 that the user interface module 18 may present to the user 20. A title bar 72 identifies the GUI 70 as a street guide. Immediately below the title bar 72, a text bar 74 identifies the street on which the vehicle is currently located. An icon 76, such as an arrowhead, may indicate the direction of travel of the vehicle using a conventional north-up representation. Below the text bar 74, a dynamic intersection list 78 conveys information relating to upcoming intersections or other points of interest. The dynamic intersection list 78 includes the names of upcoming intersections and the distances to those intersections. Icons 80 may indicate the type of intersection or other point of interest. As depicted in FIG. 3, for example, Cherry St. is a typical intersection, and 126th St. is a traffic circle. A scroll bar 82 indicates the position of the currently displayed points of interest relative to a sequence of points of interest. The dynamic intersection list 78 is automatically updated as the vehicle progresses. In addition, the user 20 can scroll through the dynamic intersection list 78 using the keypad 38, the microphone 42, or another suitable input device. Below the dynamic intersection list 78, soft key indicators facilitate activation of various features. For example, a “menu” soft key indicator 84 may allow the user 20 to access a menu of configuration and other options. A “plan” soft key indicator 86 may allow the user 20 to access a menu for planning a route, e.g., by selecting from a list of recent destinations or favorite destinations. A “view” soft key indicator 88 may allow the user 20 to toggle the display to show a detailed intersection view as depicted in FIG. 4. In some implementations, the soft key indicators 84, 86, and 88 are visually and logically associated with keys on the keypad 38 of FIG. 1. Other implementations may incorporate a touch-sensitive display screen. In such implementations, the soft key indicators 84, 86, and 88 may be rendered on areas of the display screen that, when touched, invoke the associated features. FIG. 4 depicts another example GUI 100 that the user interface module 18 may present to the user 20. A title bar 102 identifies the GUI 100 as a guide view. Immediately below the title bar 102, a detailed intersection view 104 depicts upcoming intersections or other points of interest. For example, text bars 106 and 108 identify upcoming intersections as Cherry St. and 126th St., respectively. A map area 110 depicts the vehicle as an icon 112, such as an arrowhead pointing along the current heading vector. An arrow 114 represents the current path of the vehicle, assuming the vehicle does not make any turns or similar maneuvers. The map area 110 may be depicted using a north-up representation or using a forward-up representation and is automatically updated as the vehicle progresses. In addition, the user 20 can scroll through the map area 110 using the keypad 38, the microphone 42, or another suitable input device. Below the detailed intersection view 104, soft key indicators facilitate activation of various features. For example, a “menu” soft key indicator 116 may allow the user 20 to access a menu of configuration and other options. A “plan” soft key indicator 118 may allow the user 20 to access a menu for planning a route, e.g., by selecting from a list of recent destinations or favorite destinations. A “list” soft key indicator 120 may allow the user 20 to toggle the display to show the dynamic intersection list 78 as depicted in FIG. 3. In some implementations, the soft key indicators 116, 118, and 120 are visually and logically associated with keys on the keypad 38 of FIG. 1. Other implementations may incorporate a touch-sensitive display screen. In such implementations, the soft key indicators 1116, 118, and 120 may be rendered on areas of the display screen that, when touched, invoke the associated features. As demonstrated by the foregoing discussion, various implementations may provide certain advantages. Because the navigation system presents information to the user 20 based on the current location and heading vector of the vehicle rather than on pre-programmed route information, the user 20 can receive information regarding points of interest without entering a planned destination. The readability and usability of the information conveyed to the user 20 is enhanced, particularly in relatively inexpensive vehicle navigation systems having small display screens. Such systems are better able to provide the user 20 with enough information to discern nearby points of interest without cluttering the screen with so much information that the display becomes unusable. Navigation systems having larger screens can also benefit from reduced clutter. It will be understood by those who practice the invention and those skilled in the art that various modifications and improvements may be made without departing from the spirit and scope of the disclosed embodiments. The scope of protection afforded is to be determined solely by the claims and by the breadth of interpretation allowed by law. | <SOH> BACKGROUND <EOH>An increasing number of vehicles are equipped with on-board navigation systems that display the position of the vehicle and surrounding streets, intersections, and other points of interest. Some navigation systems allow the driver to input or program a route. The navigation system then displays the position of the vehicle along the route. In addition to displaying the vehicle position along a route, a navigation system can typically also display the vehicle location even when no route is programmed. In this case, the navigation system does not have a route that provides a context for the display. Some navigation systems that incorporate relatively large color display screens can display the vehicle location in the context of a detailed map reference of the surrounding area when no route is programmed. Other navigation systems, however, incorporate smaller display screens. Rendering the vehicle location is difficult because the display screen is too small to display a map reference that is both sufficiently detailed and sufficiently free of clutter to be useful. For example, the map reference may be rendered at a sufficient level of detail, but contain so much clutter as to be unreadable from the position of the driver. Even with a relatively large display screen, some users may find a detailed map reference too cluttered to be useful. On the other hand, the map reference may be sufficiently free of clutter to allow the driver to locate the visual representation of the car, but lack detailed information as to surrounding streets. In either case, the driver does not significantly benefit from the map reference. | <SOH> SUMMARY OF THE DISCLOSURE <EOH>According to various example implementations, a vehicle navigation system provides an occupant of a vehicle with information relating to a list of intersections or other points of interest located ahead of the vehicle relative to the current direction of travel of the vehicle. The vehicle navigation system uses information about the current location of the vehicle and a heading vector that indicates the current direction of travel in connection with a navigation database to identify a list of the intersections or other points of interest along the current street. The vehicle navigation system presents this information to the occupant. As the vehicle progresses and makes turn maneuvers, the navigation system updates the list of intersections or other points of interest that the vehicle is approaching. In one implementation, information relating to a location of a vehicle is communicated to an occupant of the vehicle in the absence of predetermined route information by detemnining the location of the vehicle and a heading vector associated with the vehicle. A point of interest is identified as a function of the location of the vehicle and the heading vector associated with the vehicle. This point of interest is then communicated to the occupant of the vehicle. Another implementation is directed to a navigation system for use in a vehicle. A global positioning system (GPS) receiver is configured to determine a location of the vehicle. A data retrieval device is configured to retrieve, from a data storage medium, navigation data representing a plurality of points of interest. A processor-based subsystem is operatively coupled to the GPS receiver and to the data retrieval device. The processor-based system is configured to determine a heading vector associated with the vehicle and to receive the navigation data from the data retrieval device. The processor-based system is further configured to select a point of interest from the plurality of points of interest as a function of the location of the vehicle and the heading vector associated with the vehicle and to communicate the point of interest to an occupant of the vehicle. In still another embodiment, a processor-readable medium contains processor-executable instructions. When executed by a processor-based system in a vehicle, the processor-executable instructions cause the processor-based system to determine a location of the vehicle and a heading vector associated with the vehicle. The processor-based system then identifies a point of interest as a function of the location of the vehicle and the heading vector associated with the vehicle and communicates the point of interest to the occupant of the vehicle. Various implementations may provide certain advantages. The navigation system communicates information regarding upcoming intersections and points of interest based on the current location and heading vector of the vehicle. As a result, the occupant can receive information regarding points of interest without needing to enter a planned destination beforehand. Even when a destination is entered, the occupant can benefit from being able to determine the location of the vehicle relative to the surrounding area without the clutter of irrelevant map details. Additional advantages and features will become apparent from the following description and the claims that follow, considered in conjunction with the accompanying drawings. | 20040217 | 20061107 | 20050818 | 72745.0 | 3 | NGUYEN, TAN QUANG | PREVIEWING POINTS OF INTEREST IN NAVIGATION SYSTEM | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,780,600 | ACCEPTED | ANTI-ROOSTING DEVICE | An anti-roosting device is disclosed. The device includes a track, an electrical conductor, and an electrical source. The conductor is embedded within the track, with a portion of the conductor left exposed. The electrical source provides low amperage at high voltage to the electrical conductor such that the device is harmless to both birds and humans, but will deliver a shock that is effective in keeping birds from roosting thereon. | 1. An anti-roosting device, comprising: an elongate track; an electrical conductor at least partially embedded within said track, said electrical conductor including a plurality of wires around a rope; and an electrical source operatively coupled to said electrical conductors; wherein said track includes a substantially flat mounting surface extending substantially along a width said track; and wherein said track further includes an arcuate surface opposite said mounting surface, said electrical conductor being embedded within said arcuate surface. 2. The anti-roosting device of claim 1, wherein said electrical conductor includes at least five wires around a rope. 3. The anti-roosting device of claim 2, wherein said electrical conductor includes from five to ten wires around a rope. 4. The anti-roosting device of claim 3, wherein said electrical conductor includes nine wires around a rope. 5. The anti-roosting device of claim 2, wherein said rope is comprised of a substantially nonconductive material. 6. The anti-roosting device of claim 1, wherein said electrical conductor is generally circular in cross-section and has a diameter of approximately 0.125 inch to approximately 0.175 inch. 7. The anti-roosting device of claim 1, wherein said track includes a channel sized to substantially embed said electrical conductor while leaving a portion thereof exposed. 8. The anti-roosting device of claim 7, wherein said channel is sized to leave from approximately 1% to approximately 25% of said electrical conductor exposed. 9. The anti-roosting device of claim 8, wherein said channel is sized to leave from approximately 10% to approximately 20% of said electrical conductor exposed. 10. The anti-roosting device of claim 7, wherein said track includes a second channel sized to substantially embed a second electrical conductor while leaving a portion thereof exposed. 11. The anti-roosting device of claim 10, wherein said channels are substantially parallel to a longitudinal axis of said track. 12. The anti-roosting device of claim 11, wherein said track defines a plurality of holes between said channels for facilitating attachment of the device to an object. 13. (canceled) 14. The anti-roosting device of claim 1, further comprising a second electrical conductor embedded within said track, said second electrical conductor including a plurality of wires around a rope. 15. The anti-roosting device of claim 1, wherein said electrical source is designed to provide low amperage at high voltage to said electrical conductor. 16. The anti-roosting device of claim 15, wherein said electrical source provides approximately 3 to approximately 6 amps at approximately 4000 to approximately 8000 volts to said electrical conductor. 17. The anti-roosting device of claim 1, wherein said electrical source is a direct current source. 18. The anti-roosting device of claim 1, wherein said electrical source is an alternate current source. 19-20. (canceled) 21. The anti-roosting device of claim 1, wherein said track is substantially unitary. 22. An anti-roosting device, comprising: an elongate track; a first electrical conductor at least partially embedded within said track, said first electrical conductor including a plurality of wires around a rope; a second electrical conductor at least partially embedded within an upper surface of said track; and an electrical source operatively coupled to said first and second electrical conductors; wherein said track includes a flat mounting surface opposite said upper surface, said flat mounting surface extending at least underneath said first and second electrical conductors. 23. (canceled) 24. An anti-roosting device, comprising: an elongate track; an electrical conductor at least partially embedded within said track, said electrical conductor including a plurality of wires around a rope; and an electrical source operatively coupled to said electrical conductor; wherein said track contains a mounting surface that is designed to eliminate air gaps between said track and a surface upon which the device is mounted. 25. The anti-roosting device of claim 24, wherein: said track has a width; and said mounting surface is substantially flat and extends along a majority of said width. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing birds and other pests from inhabiting and fouling an area. In particular, the present invention relates to an anti-roosting device. 2. Description of the Related Art In many locations, the presence of birds is undesired, and even detrimental. For example, birds can interfere with the proper functioning of heating, cooling, and ventilation (HVAC) systems in commercial and residential buildings. The natural wastes associated with birds also frequently have adverse effects on people, equipment, and structures. There are some known devices for preventing the roosting of birds in these areas. However, there is no known device that as effectively prevents the roosting of birds without detrimentally affecting the birds. SUMMARY OF THE INVENTION The present invention is related to an anti-roosting device to prevent birds from roosting near an object. The device includes a track, an electrical conductor, and an electrical source. The track is preferably elongate, sturdy, and flexible. The track may include one or more channels, in which one or more electrical conductors are embedded. A portion of the electrical conductors is left exposed, such that birds landing on the device will contact the electrical conductor. The channels are sized to snugly retain the conductors therein while leaving, preferably, approximately 1% to approximately 25% of the conductor exposed. A more preferred range of exposure is from approximately 10% to approximately 20%. The channels are preferably substantially parallel to a longitudinal axis of the track. The track may have a flat side opposite the exposed electrical conductor(s) for facilitating attachment of the device to the object or area being protected. The track may be attached to the object by adhesive, such as glue or tape, between the object and the flat side. Mechanical fasteners, alone or in conjunction with the adhesive, may also be used. If mechanical fasteners are used, they are preferably connected through holes located in the track between the channels. Each electrical conductor includes a plurality of wires around a rope. Preferably, the conductors include at least five wires around a rope. More preferably, the conductors include from five to ten wires around a rope, and most preferably the conductors include nine wires around a rope. The wires are electrically conductive, and the rope is not electrically conductive. The wires and rope may be braided, and are preferably circular in cross-section with substantially the same diameter. Preferred diameters are within the range of approximately 0.02 inch to approximately 0.03 inch, inclusive. The electrical conductors may be generally circular in cross-section and have a diameter of approximately 0.125 inch to approximately 0.175 inch. The electrical source is operatively connected to the electrical conductor to provide electricity thereto. The electrical source is designed to provide low amperage at high voltage to the electrical conductor such that the device is harmless to both birds and humans, but will deliver a shock that is effective in keeping birds from roosting thereon. Preferred ranges include approximately 3 to approximately 6 amps at approximately 4000 to approximately 8000 volts. The electrical source may be either a direct current source or an alternate current source. DESCRIPTION OF THE DRAWINGS The present invention is described with reference to the accompanying drawings, in which like reference characters reference like elements, and wherein: FIG. 1 shows an anti-roosting device according to the present invention; FIG. 2 shows a detailed, cross-sectional view of an electrical conductor of the anti-roosting device of FIG. 1; and FIG. 3 shows the anti-roosting device of FIG. 1 in use. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows an anti-roosting device 1 according to the present invention. Device 1 includes an elongate track 20 and an electrical conductor 40. Track 20 is preferably comprised of a sturdy, flexible material. Furthermore, track 20 is preferably made of a non-conductive material. A preferred material for track 20 is polyethylene. Track 20 includes at least one channel 22 sized to at least partially embed electrical conductor 40 therein, while leaving a portion of conductor 40 exposed. FIG. 2 shows a detailed, cross-sectional view of electrical conductor 40. As illustrated, a preferred embodiment of conductor 40 includes a plurality of wires 42 around a rope 44. Wires 42 and rope 44 may be braided. Electrical conductor 40 preferably includes at least five wires 42 around rope 44, and more preferably from five to ten wires 42. A most preferred embodiment includes nine wires 42 around rope 44. Rope 44 is preferably made of a substantially nonconductive material, such as polyethylene, and wires 42 are made of a conductive material, such as tinned copper and stainless steel. Wires 42 and rope 44 are preferably circular in cross-section and may have substantially the same diameter. Preferred diameters are within the range of approximately 0.02 inch to approximately 0.03 inch, inclusive. Electrical conductor 40 preferably is generally circular in cross-section and has a diameter of approximately 0.125 inch to approximately 0.175 inch. Channel 22 is sized to snugly retain conductor 40 therein while leaving a portion of conductor 40 exposed such that birds landing on device 1 will contact electrical conductor 40 and receive a shock. A preferred amount of exposure is from approximately 1% to approximately 25% of conductor 40, and a more preferred amount of exposure is from approximately 10% to approximately 20% of conductor 40. These percentages may be measured as a percentage of the outer surface area or outer diameter of conductor 40. Device 1 preferably includes a second channel 23 for embedding a second electrical conductor 40. Channels 22, 23 are substantially parallel to a longitudinal axis LA of track 20. A region 24 of track 20 intermediate channels 22, 23 may define a plurality of holes 25 for facilitating attachment of device 1 to the object or area being protected. Track 20 also preferably includes a flat side 26 opposite exposed electrical conductor(s) 40 for facilitating attachment of device 1 to the object or area being protected. Device 1 further includes an electrical source 50 operatively couple to electrical conductor 40. Electrical source 50 is designed to provide low amperage at high voltage to said electrical conductor such that device 1 is harmless to both birds and humans, but will deliver a shock that is effective in keeping birds from roosting thereon. Preferably, electrical source 50 provides approximately 3 to approximately 6 amps at approximately 4000 to approximately 8000 volts to said electrical conductor. Electrical source 50 may be either a direct current source or an alternate current source. Electrical source 50 may additionally include a combination of both direct current and alternate current components, which may be beneficial in providing a backup power source in the event of a loss of power. FIG. 3 shows anti-roosting device 1 attached to an object 60 to prevent birds from roosting thereon. Object 60 may be anything or any area around which bird presence is undesired, such as ledge, duct, or parapet. Track 20 is coupled to object 60 around the area to be protected. Track 20 may be coupled by adhesive, such as glue or tape, between object 60 and flat side 26. Mechanical fasteners, alone or in conjunction with the adhesive, may also be used to couple device 1 to object 60. If mechanical fasteners are used, they are preferably connected through holes 25. Electrical source 50 is operatively coupled to electrical conductor 40, and a current is provided to prevent birds from roosting on object 60. While the preferred embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not of limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. For example, while the invention has been described above in terms of preventing birds from roosting, it may equally be used to prevent other unwanted animals from roosting or inhabiting around the object or area being protected. Thus, the present invention should not be limited by the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a device for preventing birds and other pests from inhabiting and fouling an area. In particular, the present invention relates to an anti-roosting device. 2. Description of the Related Art In many locations, the presence of birds is undesired, and even detrimental. For example, birds can interfere with the proper functioning of heating, cooling, and ventilation (HVAC) systems in commercial and residential buildings. The natural wastes associated with birds also frequently have adverse effects on people, equipment, and structures. There are some known devices for preventing the roosting of birds in these areas. However, there is no known device that as effectively prevents the roosting of birds without detrimentally affecting the birds. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention is related to an anti-roosting device to prevent birds from roosting near an object. The device includes a track, an electrical conductor, and an electrical source. The track is preferably elongate, sturdy, and flexible. The track may include one or more channels, in which one or more electrical conductors are embedded. A portion of the electrical conductors is left exposed, such that birds landing on the device will contact the electrical conductor. The channels are sized to snugly retain the conductors therein while leaving, preferably, approximately 1% to approximately 25% of the conductor exposed. A more preferred range of exposure is from approximately 10% to approximately 20%. The channels are preferably substantially parallel to a longitudinal axis of the track. The track may have a flat side opposite the exposed electrical conductor(s) for facilitating attachment of the device to the object or area being protected. The track may be attached to the object by adhesive, such as glue or tape, between the object and the flat side. Mechanical fasteners, alone or in conjunction with the adhesive, may also be used. If mechanical fasteners are used, they are preferably connected through holes located in the track between the channels. Each electrical conductor includes a plurality of wires around a rope. Preferably, the conductors include at least five wires around a rope. More preferably, the conductors include from five to ten wires around a rope, and most preferably the conductors include nine wires around a rope. The wires are electrically conductive, and the rope is not electrically conductive. The wires and rope may be braided, and are preferably circular in cross-section with substantially the same diameter. Preferred diameters are within the range of approximately 0.02 inch to approximately 0.03 inch, inclusive. The electrical conductors may be generally circular in cross-section and have a diameter of approximately 0.125 inch to approximately 0.175 inch. The electrical source is operatively connected to the electrical conductor to provide electricity thereto. The electrical source is designed to provide low amperage at high voltage to the electrical conductor such that the device is harmless to both birds and humans, but will deliver a shock that is effective in keeping birds from roosting thereon. Preferred ranges include approximately 3 to approximately 6 amps at approximately 4000 to approximately 8000 volts. The electrical source may be either a direct current source or an alternate current source. | 20040219 | 20050823 | 20050825 | 57513.0 | 0 | NGUYEN, CHAU N | ANTI-ROOSTING DEVICE | SMALL | 0 | ACCEPTED | 2,004 |
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10,780,872 | ACCEPTED | Sinus tarsi implant | An arthroeresis-prosthesis (endorthosis) system comprising a sinus tarsi implant for the purpose of blocking abnormal motion between the talus and calcaneus while allowing normal motion and alignment. In a preferred embodiment, the prosthetic device is composed of a non-metallic, specialized medical grade polymer (polyetheretherketone-PEEK) that is a combination of a frustum of a right cine and an axially extending cylinder that is cannulated and partially structured on the exterior surface. | 1. A sinus tarsi implant for use in correcting anatomical alignment of a patient's ankle bone structure comprising: a first member having an outer surface generally configured in the shape of a frustum of right cone having a circular base portion and a circular top portion with said top portion diameter less than said base portion diameter, and said first member being operable for insertion into a sinus region of the patient's sinus tarsi; and a second member, axially connected to the circular top portion of the first member and having an outer surface generally configured in the shape of a cylinder and having an outer diameter approximately equal to the diameter of the top portion of said first member and being operable for insertion into a canalis tarsi region of the patient's sinus tarsi, wherein said first and second members maintain said sinus tarsi in an anatomically correct alignment and minimize a tendency for abnormal motion between the patent's talus and calcaneus in the patient's ankle bone structure. 2. A sinus tarsi implant for use in correcting anatomical alignment of a patient's ankle bone structure as defined in claim 1 and further comprising: a third member axially connected to said base portion of said first member, said third member having an outer surface generally configured in the shape of a cylinder with an outer diameter approximately equal to the diameter of the base portion of said first member and being operable for insertion into a sinus region of the patient's sinus tarsi. 3. A sinus tarsi implant for use in correcting anatomical alignment of a patient's ankle bone structure as defined in claim 2 wherein said third member further comprises: at least one peripheral channel fashioned about said third member outer surface to engage surrounding tissue and permit fibrous tissue ingrowth to anchor said implant within the patient's sinus tarsi. 4. A sinus tarsi implant for use in correcting anatomical alignment of a patient's ankle bone structure as defined in claim 3 wherein said at least one peripheral channel further comprises: at least a first and a second peripheral channel being axially spaced along the outer surface of said third member to engage surrounding tissue and permit fibrous tissue ingrowth to anchor said implant within the patient's sinus tarsi. 5. A sinus tarsi implant for use in correcting anatomical alignment of a patient's ankle bone structure as defined in claim 1 wherein said second member further comprises: a channeled surface fashioned in said second member outer surface to engage surrounding tissue and permit fibrous tissue ingrowth to anchor said second member within the canalis tarsi region of the patient's sinus tarsi. 6. A sinus tarsi implant for use in correcting anatomical alignment of a patient's ankle bone structure as defined in claim 5 wherein said channeled surface further comprises: a continuous thread fashioned in said second member outer surface to engage surrounding tissue and permit fibrous tissue ingrowth to anchor said second member within the canalis tarsi region of the patient's sinus tarsi. 7. A sinus tarsi implant for use in correcting anatomical alignment of a patient's ankle bone structure as defined in claim 6 wherein said implant further comprises: a lateral end fashioned with a recess configured to accept a tool so that when the tool is inserted into the recess the tool is operable to advance the implant into a proper position. 8. A sinus tarsi implant for use in correcting anatomical alignment of a patient's ankle bone structure as defined in claim 1 wherein said sinus tarsi implant is composed of a composition comprising: a medical grade polymer suitable for implantation in the patient without adverse reactions. 9. A sinus tarsi implant for use in correcting anatomical alignment of a patient's ankle bone structure as defined in claim 1 wherein said sinus tarsi implant is composed of a composition comprising: a polymer selected from the group consisting of high molecular weight polyethylene, polyoxymethylene, DELRIN, polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polymethylmethacrylate (PMMA) polytetrafluoroethylene (PTFE) and DELRIN AF. 10. A sinus tarsi implant for use in correcting anatomical alignment of a patient's ankle bone structure as defined in claim 1 wherein said implant further comprises: a longitudinal bore traversing the entire length of the implant along a central longitudinal axis and fashioned to allow placement of the implant on a guide to facilitate proper surgical implantation. 11. A sinus tarsi implant for use in correcting anatomical alignment of a patient's ankle bone structure as defined in claim 1 and further comprising: said second member outer diameter is in a range from 0.6 cm to 1.1 cm. 12. A sinus tarsi implant for use in correcting anatomical alignment of a patient's ankle bone structure comprising: a first member having an outer surface generally configured in the shape of a right conical frustum having a base portion and a top portion, and being operable for insertion into a sinus region of the patient's sinus tarsi; a second member, axially connected to the top of said first member and having an outer surface generally configured in the shape of a cylinder and having an outer diameter approximately equal to the top portion of said first member and being operable for insertion into a canalis tarsi region of the patient's sinus tarsi; and a third member, axially connected to the base of said first member an having an outer surface generally configured in the shape of a cylinder and being operable for insertion into the sinus region of the patient's sinus tarsi; wherein said first, second and third members maintain said sinus tarsi in an anatomically correct alignment and minimize a tendency for abnormal motion between the patent's talus and calcaneus thereby correcting deformities in the patient's ankle bone structure. 13. A sinus tarsi implant for use in correcting anatomical alignment of a patient's ankle bone structure as defined in claim 12 wherein said third member further comprises: at least one peripheral channel fashioned about said third member outer surface to engage surrounding tissue and permit fibrous tissue ingrowth to anchor said implant within the patient's sinus tarsi. 14. A sinus tarsi implant for use in correcting anatomical alignment of a patient's ankle bone structure as defined in claim 12 wherein said second member further comprises: a channeled surface fashioned in said second member outer surface to engage surrounding tissue and permit fibrous tissue ingrowth to anchor said second member within the canalis tarsi region of the patient's sinus tarsi. 15. A sinus tarsi implant for use in correcting anatomical alignment of a patient's ankle bone structure as defined in claim 14 wherein said channeled surface further comprises: a continuous thread fashioned in said second member outer surface to engage surrounding tissue and permit fibrous tissue ingrowth to anchor said second member within the canalis tarsi region of the patient's sinus tarsi. 16. A sinus tarsi implant for use in correcting anatomical alignment of a patient's ankle bone structure as defined in claim 15 wherein said implant further comprises: a recess fashioned within a lateral end of said implant and being configured to accept a tool so that when the tool is inserted into the recess the tool is operable to advance the implant into a proper position. 17. A sinus tarsi implant for use in correcting anatomical alignment of a patient's ankle bone structure as defined in claim 12 wherein said sinus tarsi implant is composed of a composition comprising: a medical grade polymer suitable for implantation in the patient without adverse reactions. 18. A sinus tarsi implant for use in correcting anatomical alignment of a patient's ankle bone structure as defined in claim 12 wherein said sinus tarsi implant is composed of a composition comprising: a polymer selected from the group consisting of high molecular weight polyethylene, polyoxymethylene, DELRIN, polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polymethylmethacrylate (PMMA) polytetrafluoroethylene (PTFE) and DELRIN AF. 19. A sinus tarsi implant for use in correcting anatomical alignment of a patient's ankle bone structure as defined in claim 12 and further comprising: a longitudinal bore traversing the entire length of the implant along the implant longitudinal central axis and fashioned to allow placement of the implant on a guide to facilitate proper surgical implantation. 20. A sinus tarsi implant for use in correcting anatomical alignment of a patient's ankle bone structure as defined in claim 12 and further comprising: said second member outer diameter is in a range from 0.6 cm to 1.1 cm. | BACKGROUND OF THE INVENTION This invention relates to a medical apparatus for enhancing and for correcting skeletal mechanics. More specifically, this invention relates to the correction of certain bone alignment deformities that impair optimal biped mechanics. Excessive pronation (hyperpronation) is caused by abnormal motion between two bones of the foot; the ankle bone (talus) and the heel bone (calcaneus). This abnormal motion will eventually lead to anatomical mal-alignment both proximally and distally. The abnormal motion is due to obliteration or closure of a naturally occurring space (sinus) formed between the talus and calcaneus. This sinus is referred to anatomically as the sinus tarsi. In anatomical terms, the sinus tarsi is located anterior to the subtalar joint and posterior to the talocalcaneo-navicular joint. As will be described in greater detail below, the subtalar joint is formed by the posterior talar facet of the calcaneus and the posterior calcaneal facet of the talus. The talocalcaneonavicular joint is formed by the middle and anterior calcaneal facet of the talus and middle and anterior talar facet of the calcaneus. Generally speaking, when a human biped is walking or running, the individual's talus acts as a “torque converter” to transfer the weight of the body to the foot. This weight transfer is accomplished via the motion of the subtalar joint, which is mainly movement of the talus onto the calcaneus. The normal mechanics of the subtalar joint produces a triplanar motion-motion through all three anatomical planes. This motion consists of supination, and pronation. Pronation occurs when the talus moves medially (inward), anterior (forward) and plantarly (inferiorly). Supination occurs when the talus moves laterally (outward), posteriorly (backward) and dorsally (upward). Normally, there should be approximately a two-to-one ratio of supination to pronation. Some individuals suffer as a result of abnormal motion of the subtalar joint. This is often referred to as excessive pronation or, more specifically, hyperpronation. The pathomechanics of hyperpronation leads to significant deleterious effects to the bony architecture of the talus and calcaneus both proximally and distally. Hyperpronation is defined by excessive talar deviation medially (inward), anteriorly (forward), and plantarly (inferiorly). Hyperpronation is detected and diagnosed through physical examination of the foot, both non-weight bearing and weight bearing examination, as well as radiographic evaluation of the foot. Non-weight bearing examination of hyperpronation is achieved by applying pressure to the fifth metatarsal head region of the foot to dorsiflex the foot (push the foot toward the front of the shin) and if the foot turns out-ward hyperpronation is present. In the weight-bearing examination, the person stands on his/her feet and the examiner observes both pronation and supination of the subtalar joint. Normally the foot should be in a “neutral” position, that is, neither pronated nor supinated. If the foot is in a pronated position while full weight is on the foot, the foot is considered hyperpronated. Radiographic evaluation of hyperpronation is seen by examining the weight-bearing anterior-posterior (top to bottom) view and the lateral (side) view. These two projections show the relationship of the talus to the other foot bones. If the talus is medially (inward) and/or anteriorly (forward) deviated and/or plantarflexed (inferiorly) displaced hyperpronation is present. Previous implants have been designed for insertion into the sinus tarsi in an attempt to treat foot disorders. In this, one envisioned design included a mushroom-shaped implant with a stem protruding from the bottom. The implant was held in place by inserting the stem into a hole drilled into the dorsum of the calcaneus. Unfortunately, drilling can weaken the calcaneus and often resulted in direct or ultimate fracture. Moreover, the stem of the implant is subject to fracture which, of course, again leads to failure of the procedure. Also, the surgical procedures necessary for implantation is somewhat and subject to physician error. In another previously known design, an implant is threaded on an outer surface and screwed into the sinus tarsi. This implant is usually composed of high molecular weight polyethylene. Unfortunately, this device can only be gas sterilized. This allowed the device to deform under the compressive pressure to which it is subjected under normal post-operative condition. Furthermore, it was difficult to accurately locate the device properly within the sinus tarsi. In yet another design, a cylindrical implant made of a titanium alloy is threaded on an outer surface. However, this implant only corrects one portion of the deformity while both the lateral and medial portions of the sinus tarsi need correction. Furthermore, a titanium implant is much harder than surrounding bone matter. This can lead to bone wear and/or deformation. In addition, fluoroscopy is required in order to verify the position which exposes a patient to radiation. The procedure for insertion requires two separate incisions on the medial and lateral aspect of the foot and calls for a below-the-knee cast for two weeks post-operatively. Finally, the implant is made available in a series of sizes. These implants vary in size, one from the next, by specific increments. Gaps in this series can lead to under and over correction. The problems suggested in the preceding are not intended to be exhaustive but rather are among many which may tend to reduce the effectiveness of sinus tarsi implants known in the past. Other noteworthy problems may also exist; however, those presented above should be sufficient to demonstrate that previously known sinus tarsi implants will admit to worthwhile improvement. OBJECTS OF THE INVENTION It is a general object of the invention to obviate limitations in correcting abnormal foot mechanics of the type previously described. An object of the invention is to insure proper foot motion by stabilizing the motion between the talus and calcaneus. It is a related object of the invention to insure that both the medial and lateral aspects of these bones are stabilized. Another object of the invention is to block hyperpronation between the talus and calcaneus while allowing normal foot motion. A further object of this invention is to correct mal-alignment, both proximally and distally, of the talus and calcaneus. Another object of the invention is to provide an implant that will not, over time, wear or deform the talus and calcaneus. Still another object of the invention is to provide an implant that will not wear or deform over time and thus fail. Another object is to provide an implant that will remain in place without a separate anchoring procedure. Another object of the invention is a method of correctly positioning an implant in the space between the talus and calcaneus bones without having to verify the correct position with a fluoroscope and thus expose the user to radiation. A further object of the invention is to provide less invasive surgery for inserting an implant. A related object of the invention it to provide a sinus tarsi implant without requiring a post-operative below-the-knee cast. BRIEF SUMMARY OF THE INVENTION An embodiment of the present invention that is intended to accomplish at least some of the foregoing objects comprises blocking motion of the subtalar joint with an internally placed orthotic device. In medical terms, this embodiment comprises a subtalar arthroeresis endorthosis implantation system. The implant is termed a subtalar or, more specifically, a sinus tarsi arthroeresis which maintains the sinus tarsi in an anatomically correct alignment, allowing the normal physiological motion to occur while minimizing a tendency for abnormal pre-operative motion. The sinus tarsi implant of the subject invention is generally funnel shaped or tapered and fits into the sinus tarsi. The implant comprises a frustum of a right cone portion as well as an integral extension. The frustum portion is considered the superficial or lateral portion of the implant and may be operably positioned within the lateral or sinus region of the sinus tarsi. A small diameter cylindrical portion of the implant is considered the medial side of the implant and will be operably positioned within a deeper side of the sinus tarsi, the canalis tarsi. The surface of the implant optionally contains channels or a roughened texture in selected regions. These surface regions will, in a preferred embodiment, interact with the surrounding tissue. This interaction increases the mechanical retention between the surface of implant and the surrounding tissue and thus helps maintain the implant in a proper anatomical position. The sinus tarsi implant of the subject invention is preferably constructed of a medical grade polymer. The polymer composition will allow for less trauma to the external bone surface as compared to a metal alloy based implant. The implant optionally has a hole bored through its longitudinal axis (a cannula) that allows for accurate placement into the sinus tarsi via a guide wire or guide peg. BRIEF DESCRIPTION OF THE DRAWINGS Other objects and advantages of the present invention will become apparent from the following detailed description of preferred embodiments taken in conjunction with the accompanying drawings wherein: FIG. 1 is a dorsal view of the bone structure of a human foot with a sinus tarsi implant in situ displaying the axis of rotation of the subtalar joint relative to the midline; FIG. 2 is a lateral view of the bone structure of a human foot with an implant in situ displaying the axis of rotation of the subtalar joint relative to the horizontal plane; FIG. 3 is a perspective view of a sinus tarsi implant in accordance with a preferred embodiment of the invention; FIG. 4 is a side view of the sinus tarsi implant shown in FIG. 3; FIG. 5 is an end view of the sinus tarsi implant shown in FIG. 3; FIG. 6 is a cross-sectional view of the subject sinus tarsi implant taken along section line 6-6 in FIG. 3; FIG. 7 is a broken away view taken in the general direction of arrow “7” in FIG. 2, of a left foot with a sinus tarsi implant in situ; FIG. 8 is a broken away view taken in the general direction of arrow “8” in FIG. 2, of a left foot with the talus removed to reveal the bottom half of the sinus tarsi and an implant in situ in accordance with the subject invention; and FIG. 9 is a broken away view of taken in the general direction of arrow “9” in FIG. 2, of a left foot with the calcaneus removed to reveal the top half of the sinus tarsi with an implant in situ in a correct anatomical position. DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings wherein like numerals indicate the parts, FIG. 1 is a schematic representation of a patient's foot with a sinus tarsi implant 100 placed in accordance with a preferred embodiment of the invention. As described previously, the implant operates by arthroeresis (blocking of motion) of the patient's subtalar joint. The subtalar joint is the articulation between the talus 102 superiorly and the calcaneus 104 inferiorly. FIG. 1 also illustrates an axis A-A of subtalar joint motion which is approximately 16 degrees measured from a midline axis B-B of a human foot. FIG. 2 depicts the sinus tarsi implant 100, talus 102 and calcaneus 104 in a side view. Also shown, axis C-C of subtalar joint motion is approximately 42 degrees measured with respect to a horizontal plane. FIG. 2 further discloses line-of-sight views “7,” “8,” and “9” for FIGS. 7-9 respectively. FIG. 3 illustrates a perspective view of an implant 100 comprising a first member 106 with an outer surface configuration generally in the shape of a frustum of a right cone. A frustum is the portion of a right circular cone lying between a circular cone base and a plane parallel to the base cutting off a top portion of the cone. A second member 108 is longitudinally attached to the frustum member 106 at the smaller end. The second member 108 is preferably a cylinder with a diameter substantially equal to the diameter of the small end of the frustum member 106. FIG. 3 also discloses an optional third member 110 which is another cylindrical member having a diameter substantially equal to the diameter of the base of the frustum 106. FIG. 4 is a side view of an implant that illustrates the specific members that make up an implant. The size and shape of these members are preferably determined as follows, the first member 106 is designed to sit on the lateral most aspect of the canalis tarsi. (The beginning or outermost aspect of the canalis tarsi. See FIGS. 7-9 described below.) In a preferred embodiment, the first member has an outer surface generally shaped as a right conical frustum. The smaller end is equal in diameter to the second member 108 and the larger end is equal in diameter to the optional third member 110. Together, these members preferably form a continuous solid outer surface. As described below, the first member 106 will also play a role in the correct positioning of the implant. The second member 108 has an outer surface generally cylindrical in shape with an outer diameter approximately equal to that of the smaller end of the first (or frustum) member 106. Preferably fashioned about the outer surface of the second member is a series of one or more channels 112. In a preferred embodiment, the channeled surfaces are fashioned as a continuous thread. In addition, however, other tissue engagement surfaces are envisioned such as sinusoidal shapes or microporous cylindrical surfaces to promote interactions with connective tissue within the sinus tarsi. The second member 108 is designed to insert into the narrow, medial, portion of the sinus tarsi, the canalis tarsi. Note again FIGS. 7-9 below. The second member provides the important functions of anchoring the implant 100 in place and preventing collapse of the canalis tarsi canal. The channeling or threading serves to operably engage the surrounding soft tissue and ligaments and thus firmly and permanently anchors the implant in place. Anchoring the implant with channeling or threading is a significant improvement of prior art methods of anchoring. For example, other subtalar blocking implants were anchored by drilling a vertical hole in the dorsal aspect of the calcaneus that forms the floor of the sinus/outer portion of the sinus tarsi. This lead to a problem of weakening and fracture of the calcaneus. The outer diameter of the second member 108 is selected to be large enough to prevent collapse of the canalis tarsi canal but not so large as to interfere with normal foot motion. In a preferred embodiment, a set of implants are provided having second member outer diameters ranging 0.6 cm to 1.1 cm in 0.10 cm increments. For this particular embodiment, the proper size is determined as explained below in Surgical Procedures and Instrumentation. An optional third member 110 is contemplated that extends out from the larger end of the first (or frustum) member 106 in the general shape of a cylinder. In other words, a cylindrical member 110 is axially connected to the base of the frustum 106. This portion of the implant is designed to rest in the outer most (lateral) region of implantation, sitting in the sinus portion of the sinus tarsi, note particularly FIG. 8. For further stabilization, the outer surface of member 110 can be modified to incorporate tissue engagement surfaces as described above. In a preferred embodiment, one or more peripheral channels 114 are fashioned into the outer surface of member 110 to permit fibrous tissue ingrowth. In a further embodiment, a plurality of two or more peripheral channels can be so fashioned. The third member 110 is generally not tapered. It has approximately the same outer diameter along its entire length as the base of the frustum 106. However, the third member can also have an outer surface with a slight degree of taper with the slightly larger diameter at the outermost aspect of the implant. The third member 110 functions (together with the first member) to block medial and anterior deviation of the talus. As a result, the implant blocks hyperpronation of the user's foot while at the same time allowing normal flexing of the user's foot. In order to properly block abnormal motion while allow normal motion, the third member 110 must have a carefully chosen outer diameter. In a preferred embodiment, a set of implants are provided having third member outer diameters ranging from 0.85 cm to 1.6 cm in 0.15 cm increments. FIG. 5 illustrates a lateral end view of an implant. The lateral end is located at the frustum member base. Alternatively, if an optional third member is attached, the lateral end is at the free end of the third member. In a preferred embodiment, this end is provided with a recess having a selected geometric shape. FIG. 5 illustrates a TORX shaped drive recess 118. The recess is configured to accept the end of an insertion tool having a complementary geometric shape. Preferably, the tool would be inserted into the recess and used to advance the implant into position as explained below. Any geometric shape can be used, preferably a shape in which maximum torque can be applied without slippage. Examples, of suitable shapes include straight slots (flat heads), cruciate (PHILLIPS heads), hexagonal, POSIDRIVE, TORX, Allen-type and others. FIG. 6 is a cross-sectional view of a preferred embodiment of the implant. FIG. 6 reveals a cannula or longitudinal bore 116 traversing the entire length of the implant along a central longitudinal axis. The bore is fashioned to allow placement of the implant on a guide to facilitate proper surgical implantation. The implantation method is described below. Turning now to FIG. 7, note sheet 4, this figure illustrates a left foot viewed from the front generally along line-of-sight “7” in FIG. 2. An implant 100 is shown together with cross-sections of both a left talus 102 and a left calcaneus 104. As explained previously, the implant is properly positioned when the frustum member abuts the lateral most aspect of the canalis tarsi. This can be seen in FIG. 7. The lateral most aspect of the canalis tarsi is the region in which the canal narrows. FIG. 7 illustrates that in the narrowing region an implant is in contact with the surrounding bone. FIG. 7 also illustrates the second member in the deepest, or medial, end of the canal. The end of the second member is shown abutting the sulcus tali as explained above. Another method by which one insures proper positioning is to insert an implant until the end of the second member abuts the sulcus tali. This method can be used separately or together with the method above. FIG. 8 illustrates in detail an implant 100 in situ viewed from above, generally along line-of-sight “8” in FIG. 2. Revealed are the structures of the calcaneus 104 that define the bottom half of the sinus tarsi. The sinus tarsi is posterior to (behind) the talocalcaneonavicular joint which comprises the middle 120 and anterior talar facet 122 of the calcaneus 104. The sinus tarsi is anterior to (in front of) the subtalar joint which comprises the posterior talar facet 124 of the calcaneus 104. FIG. 9 illustrates an implant 100 in situ viewed from below, generally along line-of-sight “9” in FIG. 2. FIG. 9 reveals the structures of the talus 102 that define the top half of the sinus tarsi. These structures are the complement of those illustrated in FIG. 8. The sinus tarsi is posterior to (behind) the talocalcaneonavicular joint which comprises the middle 126 and anterior calcaneal facet of the talus 102. The sinus tarsi is anterior to (in front of) the subtalar joint which comprises the posterior calcaneal facet 128 of the talus 102. The subject invention is intended to provide a long term implant with expected useful life ranging from a period of years to a period of decades. Moreover, the subject invention is intended to be operably a permanent implant; one that will rarely or preferably never require replacement over the lifetime of the user. In this, the selected material of an implant 100 must be soft enough so as to prevent excessive wear and deformation of the surrounding bones causing undesirable side effects but, concomitantly, durable enough so that the implant itself will not excessively wear and deform and eventually fail or require premature replacement. Turning now to the compositions from which the implant is made, in a preferred embodiment, an implant is made entirely from a single substance. The implant composition preferably comprises a medical grade polymer suitable for the insertion in the body in that it is substantially inert with respect to chemical reactions present in the body and is unlikely to result in adverse reactions, infections, adverse immunologic reactions such as allergic reactions or rejection. Still another preferred embodiment is a medical grade polymer suitable for long term or permanent implantation as defined above. It is presently envisioned that the implant composition will comprise suitable polymers such as high molecular weight polyethylene, polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polymethyl-methacrylate (PMMA), polytetrafluoroethylene (PTFE), crystalline plastics, polyoxymethylene and DELRIN. The implant composition need not be a single substance. Indeed it is envisioned that compositions comprising blends of two or more substances will be suitable. Suitable blends include combinations of polymer fibers dispersed in resins such as DELRIN AF, a blend of PTFE fibers uniformly dispersed in DELRIN acetal resin. Polymer research has resulted in the development of scores of high grade polymers. These polymers have physical properties that cover the entire range of properties (such as durability and hardness) from metallic and plastic. Accordingly, it is envisioned that many other compositions will be suitable for use with this implant so long as these compositions have the desired properties. It is also contemplated that multiple substances can be combined to form a hybrid implant combining the advantageous properties of each substance. For example, more durable substances can be combined with more flexible substances. High coefficient of friction substances can be combined with low coefficient of friction substances. These substances can be placed in specific portions of the implant where the corresponding property is most critical. Alternatively, the substances can be blended together in a uniform ratio throughout the entire implant. Also, while post operative imaging (fluoroscopic, magnetic resonance imaging, etc) is not needed for proper placement of the implant, imaging may be desired for special purposes. In such cases, an opaque structure can be imbedded into the implant or an opaque substance added to the polymer for the purposes of imaging. It is important to note that in cases where the bone surrounding the implant is protected from wear then harder, more durable materials can be used including metal alloys. For example, biotechnological techniques to stimulate growth of bone cells (osteogenesis) and thus replace worn regions of bone can permit the use of harder materials. Of course, if the implant is only required for a short time then the material from which the implant is made is less critical. Furthermore, any prior art implant material can also be used if the patient is willing to forgo the above advantages of using polymers for any reason. In the context of this invention, terms such as “generally shaped,” “generally configured in the shape,” “generally cylindrically configured” etc. are meant to indicate that the implant may, but need not be shaped so as to conform to strict definitions from solid geometry for solids such as “cylinders” and “frustums.” Indeed, in order to provide an implant with the proper size and shape for every patient, a range of sizes and shapes are contemplated. At one extreme, a “standard set” is utilized where a set of “consensus” sizes and shapes implants are pre-manufactured and provided to health care providers and their patients. This particular embodiment has the advantage of being the most uniform and therefore the least expensive for the patient. At the other extreme, a “custom design” is envisioned where the exact size and shape is determined only after precise, detailed measurements of the inner dimensions of a patient's sinus tarsi. As a result, the generally cylindrical portions of the implant may be tapered or shaped if necessary; however, the general cylindrical configuration will remain. For similar reasons, the first member, or generally frustum shaped portion, may be concave or convex as appropriate; however, the general funnel configuration will remain. In effect, with the custom design method there are as many different shapes and sizes as there are patients. The custom design embodiment has advantages such as the patient receiving a precise amount of arthroeresic correction (degree of blocking of abnormal motion) which could be critical in special cases, for example elite athletes, dancers and others whose occupations place unusual stresses on this region. Thus, the actual number of different sizes and shapes of implants to be manufactured will ultimately depend upon economic considerations. If cost is the predominant factor than a relatively small number of different sized and shaped implants will be manufactured. On the other hand, as precision fit becomes a more dominant factor, then the number of different sizes and shapes available will increase accordingly, perhaps to a very large number. In addition to the shape of the implant overall, the shape of the transition between the cylinder and frustum can also vary. This transition need not be abrupt as depicted, for example, in the implant 100 of FIG. 4. (Note the relatively sharp transition edge between the optional third member 110 and the first member 106 and between the first member 106 and the second member 108). Rather, the transition could be smooth and gradual leaving no sharp “edge.” Surgical Procedures and Instrumentation Instrumentation of this system includes a set of cannulated probing devices, a set of implants, a cannulated insertion tool and a guide wire or guide pin. In a preferred embodiment the probing devices have a diameter ranging from 0.6 cm to 1.1 cm to correspond to the size implant required for correction. Each probing device is increased in diameter by 1 mm. The sinus tarsi implants are preferably provided in a set that range in size. Measuring from the outer diameter of narrow part of the implant (the second member) the set will, preferable, have a gauge from 0.6 cm to 1.1 cm. Implant size should, preferably, increase 1 mm in diameter from 0.6 cm to 1.1 cm. A cannulated insertion tool is also included to advance the implant into the sinus tarsi. In a preferred embodiment, the insertion tool functions much like a screw driver as described below. A preferred operative procedure consists of making a 1 cm to 2 cm linear incision over the sinus tarsi parallel to the relaxed skin tension lines. The incision is deepened via blunt dissection to the sinus tarsi. The proper angle along which the implant is inserted into the patients sinus tarsi is then determined with one of the probing devices. The 0.6 cm cannulated probing device is inserted into the sinus tarsi from lateral distal dorsal to medial proximal plantar until it is palpated exiting the medial aspect of the sinus tarsi. The angle of the probing device is the proper angle along which the implant is inserted. A guide (preferably a guide wire or a guide pin) is then inserted into the cannula of the probing device and is left in place until the end of the procedure. Starting with the smallest diameter probe (0.6 cm) subsequent larger sized probes are inserted over the guide until the appropriate size implant is determined. As noted above, the implant 100 is cannulated (fashioned with a central longitudinal hole or cannula) 116 so that the implant can be placed on the guide followed by the cannulated insertion tool. Through the action of the insertion tool, the implant is then advanced into the sinus tarsi until proper placement is achieved. Correct placement of the implant occurs when the first member 106 abuts the lateral most aspect of the canalis tarsi. (The beginning or outermost aspect of the canalis tarsi.) See the middle members of the implants 100 in FIGS. 7-9. Alternatively, placement can be achieved when the second member 108 abuts the lateral aspect of the talus, the sulcus tali. See the end of the second member (the small member) of implant 100 in FIG. 7. In a preferred embodiment, the implant is advanced into position by rotation. The implant can be rotated into position by use of any conventional method of applying torque, including the use of manual tools and power tools. In a preferred embodiment, the insertion tool is inserted into a recess on the lateral end of the implant and torque is applied. After the implant is fully inserted the incision is closed. The method of closure of the incision is surgeon's choice. Summary of Major Advantages of the Invention After reading and understanding the foregoing description of preferred embodiments of the invention, in conjunction with the illustrative drawings, it will be appreciated that several distinct advantages of the subject implant system are obtained. Without attempting to set forth all of the desirable features and advantages of the implant and associated methods, at least some of the major advantages of the invention are the stabilization of both the medial and lateral aspects of the talus and calcaneus by the corresponding segments of the implant in contact with these regions which results in blocking hyperpronation of the foot while allowing normal motion. Another advantage is the long useful lifetime of the implant. When the implant is made of the correct material, it will neither wear the surrounding bones nor will the implant wear. A related advantage that also increases the lifetime of the implant is the permanent anchoring of the implant by way of the peripheral channels and threading. Failure due to slippage out of position will be rare or absent. Also, the surrounding bones remain strong as compared to procedures in which anchoring is achieved by drilling a hole into the calcaneus or the use of other invasive anchoring methods. As a result, complications stemming from weak surrounding bones are unlikely. A still further advantage of the implant system is the ability to accurately position the implant without irradiation. The implant is correctly positioned when the implant abuts the lateral most aspect of the canalis tarsi or the sulcus tali or both. Thus, there is no need for a fluoroscope (and irradiation of the user's foot) to verify the positioning. Another advantage of the subject sinus tarsi implant is primary correction of hyperpronation, talipes valgus, pes planus, and other related rearfoot and forefoot deformities. The implant will also be used for secondary correction of growing pains, shin splints, posterior tibial tendon dysfunction, plantar fasciitis, hallux abductovalgus, metatarsus primus varus and elevatus, metatarsus adducts, contracted toes, abnormal gait, intermetarsal neuromas, as well as sciatica, patellofemoral pain, genu varum anterior pelvic tilt, lumbar lordosis, etc. Yet, another advantage is that the implant is inserted via a minimally invasive procedure and no casting is needed following the procedure so that there is a quick recovery. In describing the invention, reference has been made to preferred embodiments. Those skilled in the art and familiar with the disclosure of the subject invention, however, may recognize additions, deletions, substitutions, modifications and/or other changes which will fall within the purview of the invention as defined in the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>This invention relates to a medical apparatus for enhancing and for correcting skeletal mechanics. More specifically, this invention relates to the correction of certain bone alignment deformities that impair optimal biped mechanics. Excessive pronation (hyperpronation) is caused by abnormal motion between two bones of the foot; the ankle bone (talus) and the heel bone (calcaneus). This abnormal motion will eventually lead to anatomical mal-alignment both proximally and distally. The abnormal motion is due to obliteration or closure of a naturally occurring space (sinus) formed between the talus and calcaneus. This sinus is referred to anatomically as the sinus tarsi. In anatomical terms, the sinus tarsi is located anterior to the subtalar joint and posterior to the talocalcaneo-navicular joint. As will be described in greater detail below, the subtalar joint is formed by the posterior talar facet of the calcaneus and the posterior calcaneal facet of the talus. The talocalcaneonavicular joint is formed by the middle and anterior calcaneal facet of the talus and middle and anterior talar facet of the calcaneus. Generally speaking, when a human biped is walking or running, the individual's talus acts as a “torque converter” to transfer the weight of the body to the foot. This weight transfer is accomplished via the motion of the subtalar joint, which is mainly movement of the talus onto the calcaneus. The normal mechanics of the subtalar joint produces a triplanar motion-motion through all three anatomical planes. This motion consists of supination, and pronation. Pronation occurs when the talus moves medially (inward), anterior (forward) and plantarly (inferiorly). Supination occurs when the talus moves laterally (outward), posteriorly (backward) and dorsally (upward). Normally, there should be approximately a two-to-one ratio of supination to pronation. Some individuals suffer as a result of abnormal motion of the subtalar joint. This is often referred to as excessive pronation or, more specifically, hyperpronation. The pathomechanics of hyperpronation leads to significant deleterious effects to the bony architecture of the talus and calcaneus both proximally and distally. Hyperpronation is defined by excessive talar deviation medially (inward), anteriorly (forward), and plantarly (inferiorly). Hyperpronation is detected and diagnosed through physical examination of the foot, both non-weight bearing and weight bearing examination, as well as radiographic evaluation of the foot. Non-weight bearing examination of hyperpronation is achieved by applying pressure to the fifth metatarsal head region of the foot to dorsiflex the foot (push the foot toward the front of the shin) and if the foot turns out-ward hyperpronation is present. In the weight-bearing examination, the person stands on his/her feet and the examiner observes both pronation and supination of the subtalar joint. Normally the foot should be in a “neutral” position, that is, neither pronated nor supinated. If the foot is in a pronated position while full weight is on the foot, the foot is considered hyperpronated. Radiographic evaluation of hyperpronation is seen by examining the weight-bearing anterior-posterior (top to bottom) view and the lateral (side) view. These two projections show the relationship of the talus to the other foot bones. If the talus is medially (inward) and/or anteriorly (forward) deviated and/or plantarflexed (inferiorly) displaced hyperpronation is present. Previous implants have been designed for insertion into the sinus tarsi in an attempt to treat foot disorders. In this, one envisioned design included a mushroom-shaped implant with a stem protruding from the bottom. The implant was held in place by inserting the stem into a hole drilled into the dorsum of the calcaneus. Unfortunately, drilling can weaken the calcaneus and often resulted in direct or ultimate fracture. Moreover, the stem of the implant is subject to fracture which, of course, again leads to failure of the procedure. Also, the surgical procedures necessary for implantation is somewhat and subject to physician error. In another previously known design, an implant is threaded on an outer surface and screwed into the sinus tarsi. This implant is usually composed of high molecular weight polyethylene. Unfortunately, this device can only be gas sterilized. This allowed the device to deform under the compressive pressure to which it is subjected under normal post-operative condition. Furthermore, it was difficult to accurately locate the device properly within the sinus tarsi. In yet another design, a cylindrical implant made of a titanium alloy is threaded on an outer surface. However, this implant only corrects one portion of the deformity while both the lateral and medial portions of the sinus tarsi need correction. Furthermore, a titanium implant is much harder than surrounding bone matter. This can lead to bone wear and/or deformation. In addition, fluoroscopy is required in order to verify the position which exposes a patient to radiation. The procedure for insertion requires two separate incisions on the medial and lateral aspect of the foot and calls for a below-the-knee cast for two weeks post-operatively. Finally, the implant is made available in a series of sizes. These implants vary in size, one from the next, by specific increments. Gaps in this series can lead to under and over correction. The problems suggested in the preceding are not intended to be exhaustive but rather are among many which may tend to reduce the effectiveness of sinus tarsi implants known in the past. Other noteworthy problems may also exist; however, those presented above should be sufficient to demonstrate that previously known sinus tarsi implants will admit to worthwhile improvement. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>An embodiment of the present invention that is intended to accomplish at least some of the foregoing objects comprises blocking motion of the subtalar joint with an internally placed orthotic device. In medical terms, this embodiment comprises a subtalar arthroeresis endorthosis implantation system. The implant is termed a subtalar or, more specifically, a sinus tarsi arthroeresis which maintains the sinus tarsi in an anatomically correct alignment, allowing the normal physiological motion to occur while minimizing a tendency for abnormal pre-operative motion. The sinus tarsi implant of the subject invention is generally funnel shaped or tapered and fits into the sinus tarsi. The implant comprises a frustum of a right cone portion as well as an integral extension. The frustum portion is considered the superficial or lateral portion of the implant and may be operably positioned within the lateral or sinus region of the sinus tarsi. A small diameter cylindrical portion of the implant is considered the medial side of the implant and will be operably positioned within a deeper side of the sinus tarsi, the canalis tarsi. The surface of the implant optionally contains channels or a roughened texture in selected regions. These surface regions will, in a preferred embodiment, interact with the surrounding tissue. This interaction increases the mechanical retention between the surface of implant and the surrounding tissue and thus helps maintain the implant in a proper anatomical position. The sinus tarsi implant of the subject invention is preferably constructed of a medical grade polymer. The polymer composition will allow for less trauma to the external bone surface as compared to a metal alloy based implant. The implant optionally has a hole bored through its longitudinal axis (a cannula) that allows for accurate placement into the sinus tarsi via a guide wire or guide peg. | 20040219 | 20060425 | 20050825 | 92887.0 | 1 | MILLER, CHERYL L | SINUS TARSI IMPLANT | SMALL | 0 | ACCEPTED | 2,004 |
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10,780,878 | ACCEPTED | Method and structure for picosecond-imaging-circuit-analysis based built-in-self-test diagnostic | A method (and structure) of at least one of testing, diagnosing, and monitoring an operation of an electronic circuit, includes interrupting a clock signal used to provide a clocking for a normal operation of the circuit and using a second clock signal to repeatedly cycle through a predetermined cycle of operations for the circuit. | 1. A method of at least one of testing, diagnosing, and monitoring an operation of an electronic circuit, said method comprising: interrupting a clock signal used to provide a clocking for a normal operation of said circuit; and using a second clock signal to repeatedly cycle through a predetermined cycle of operations for said circuit. 2. The method of claim 1, further comprising: causing a data signal sequence in said circuit to flow in a reverse direction during the repeated cycling of said predetermined cycle of operation. 3. The method of claim 2, wherein said data signal sequence is reversed by controlling a multiplexer. 4. The method of claim 3, wherein: said circuit comprises a scan chain of latches; said reversed data signal sequence occurs in said scan chain of latches; and said multiplexer interconnects a master flipflop and a slave flipflop in latches that comprise said scan chain. 5. The method of claim 1, further comprising: collecting data on an emission of photons that occur from said circuit during the repeated cycling of said predetermined cycle of operations. 6. The method of claim 1, further comprising: prior to said interrupting said clock signal, performing a Built-In Self Test (BIST) sequence on said circuit. 7. The method of claim 6, further comprising: analyzing a result of said BIST sequence of said circuit. 8. The method of claim 7, further comprising: beginning an execution of said BIST sequence a second time, wherein said interruption of said interrupting a clock signal occurs at a step in said BIST sequence determined during said analyzing to have a failure. 9. An electronic circuit testing apparatus, comprising: a first clock signal line to operate an electronic circuit during a normal sequencing of operations; an interrupt signal line causing said first clock signal to stall in a middle of a cycle; and a second clock signal line to operate said electronic circuit during a period when said first clock signal is stalled. 10. The apparatus of claim 9, further comprising: a signal line to cause a data signal sequence in said circuit to flow in a reverse direction during a period said first clock signal is stalled. 11. The apparatus of claim 9, further comprising: a controller to control said interrupt signal line. 12. The apparatus of claim 9, further comprising: a controller to control an execution of a Built-In Self Test (BIST) sequence of said electronic circuit. 13. The apparatus of claim 9, further comprising: a detection module to detect an activity in said electronic circuit. 14. The apparatus of claim 13, wherein said detection module comprises: a light detector coupled to photomultiplier. 15. The apparatus of claim 14, wherein said light detector detects energy in an infrared light wavelength. 16. The apparatus of claim 15, further comprising: an image analyzer to analyze images obtained from said light detector. 17. The apparatus of claim 12, further comprising: a computer module to analyze a result of said BIST sequence. 18. The apparatus of claim 17, wherein the analysis of said BIST sequence comprises a determination of at least one of a failing pattern of said BIST sequence and a failing path. 19. The apparatus of claim 18, wherein said controller causes said BIST sequence to execute to a position in said BIST sequence where said failing pattern has been determined. 20. A signal-bearing medium tangibly embodying a program of machine-readable instructions executable by a digital processing apparatus to perform a method of at least one of testing, diagnosing, and monitoring an operation of an electronic circuit, said method comprising: interrupting a clock signal used to provide a clocking for a normal operation of said circuit; and using a second clock signal to repeatedly cycle through a predetermined cycle of operations for said circuit. 21. The signal-bearing medium of claim 20, said method further comprising at least one of: causing a data signal sequence in said circuit to flow in a reverse direction during the repeated cycling of said predetermined cycle of operation; collecting data on an emission of photons that occur from said circuit during the repeated cycling of said predetermined cycle of operations; prior to said interrupting said clock signal, performing a Built-In Self Test (BIST) sequence on said circuit; analyzing a result of said BIST sequence of said circuit; and beginning an execution of said BIST sequence a second time, wherein said interruption of said interrupting a clock signal occurs at a position in said BIST sequence determined during said analyzing to have a failure. 22. An electronic circuit, comprising: at least one scan chain of latches; and a mechanism to allow a data flow in said scan chain to be reversed in direction. 23. The electronic circuit of claim 22, wherein each said latch comprises a master flipflop and a slave flipflop and said mechanism to reverse data flow comprises a multiplexer interconnected between said master flipflop and said slave flip-flop. 24. An electronic apparatus, comprising: at least one electronic circuit that includes at least one scan chain of latches and a mechanism corresponding to said at least one scan chain to allow a data flow in said scan chain to be reversed in direction. 25. The electronic apparatus of claim 24, wherein each said latch comprises a master flipflop and a slave flipflop and said mechanism to reverse data flow comprises a multiplexer interconnected between said master flipflop and said slave flipflop. 26. A method of at least one of testing, diagnosing, and monitoring an operation of an electronic circuit, said method comprising: mounting said electronic circuit such that a photodetector can detect photon emissions due to an operation of said electronic circuit; exercising said electronic circuit with a built-in-self-test sequence; determining a position in said built-in-self-test sequence where a failure occurs; and recycling a plurality of times through a sequence of said built-in-self-test sequence at said determined position in said built-in-self-test, said photodetector detecting a photon emission due to activity of said electronic circuit during said recycling, said recycling thereby causing an amplification effect of said photon emission during said recycling. 27. The method of claim 26, wherein said recycling is caused by: interrupting a clock signal used to provide a clocking for a normal operation of said circuit; and using a second clock signal to repeatedly cycle through a predetermined cycle of operations for said circuit. 28. The method of claim 26, wherein said electronic circuit comprises at least one scan chain of latches, said method further comprising: causing a reverse in direction of a signal flow through said scan chain of latches during said recycling. 29. The method of claim 28, wherein said latches comprise a master flipflop and a slave flipflop and said causing a reverse in direction is due to activation of a multiplexer that interconnects said master flipflop and said slave flip-flop. 30. The method of claim 26, further comprising: analyzing said photon emission to determine a failed component in said electronic circuit. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to testing and diagnosis of failures in integrated circuits. More specifically, a clocking signal in a Built-In Self Test (BIST) sequence is interrupted to permit a second clocking cycle to repeatedly recycle through a particular section of the BIST. In an exemplary embodiment, activity in the circuit is determined by detecting photons emitted during this second clocking cycle. 2. Description of the Related Art The rapid densification of VLSI (Very Large Scale Integrated) circuit devices, associated with high speed circuit performance, and relatively short time-to-market, has driven the need to rapidly characterize and diagnose complex designs early in the product cycle. Concurrently, conventional characterization test tools and diagnostic techniques, already somewhat limited, are quickly becoming obsolete. These problems in turn show the need for a novel test and diagnostic methodology that combines new Physical Failure Analysis (PFA) tools with integrated test and diagnostics support built-in the semiconductor device. Some of the built-in test and diagnostic functions may be based on several Design for Test (DFT) techniques such as Level Sensitive Scan Design (LSSD), Logic Built-In-Self-Test (LBIST), Array Built-In-Self-Test (ABIST), On-product-clock-generation (OPCG), and others. Thus, a need exists so that testing tools and diagnostic methods keep pace with the newer techniques of semiconductor design and fabrication. SUMMARY OF THE INVENTION In view of the foregoing, and other, exemplary problems, drawbacks, and disadvantages of the conventional system, it is an exemplary feature of the present invention to provide a novel technique for integrated circuit testing and diagnosis. It is another exemplary feature of the present invention to overcome a problem in a testing technique in which emitted photons are detected to determine circuit activity. It is another exemplary feature of the present invention to provide a technique that can be used to overcome a problem in a testing technique in which circuit activity is shielded by overlying layers of wiring on a chip. It is another exemplary feature of the present invention to provide a method in which photon emission can be amplified in a Built-In Self Test (BIST) process by repeatedly recycling through a sequence of the BIST test. It is another exemplary feature of the present invention to provide a method in which a normal clocking cycle of a BIST test is interrupted and a second clocking cycle is used to repeatedly exercise a sequence of the BIST test. To achieve the above exemplary features and others, in a first exemplary aspect of the present invention, described herein is a method of at least one of testing, diagnosing, and monitoring an operation of an electronic circuit, including interrupting a clock signal used to provide a clocking for a normal operation of the circuit and using a second clock signal to repeatedly cycle through a predetermined cycle of operations for the circuit. In a second exemplary aspect of the present invention, described herein is a structure to execute the above-described method. In a third exemplary aspect of the present invention, described herein is also a signal-bearing medium tangibly embodying a program of machine-readable instructions executable by a digital processing apparatus to perform the above-described method. In a fourth exemplary aspect of the present invention, described herein is also an electronic circuit including at least one scan chain of latches and a mechanism to allow a data flow in the scan chain to be reversed in direction. In a fifth aspect of the present invention, described herein is an apparatus having at least one component having at least one electronic circuit that includes at least one scan chain of latches and a mechanism to allow a data flow in the scan chain to be reversed in direction. In a sixth aspect of the present invention, also described herein is a method of at least one of testing, diagnosing, and monitoring an operation of an electronic circuit, including mounting the electronic circuit such that a photodetector can detect photon emissions due to an operation of the electronic circuit, exercising the electronic circuit with a built-in-self-test sequence, determining a position in the built-in-self-test sequence where a failure occurs, and recycling a plurality of times through a sequence of the built-in-self-test sequence at the determined position in the built-in-self-test, the photodetector detecting a photon emission due to activity of the electronic circuit during the recycling, the recycling thereby causing an amplification effect of the photon emission during the recycling. The exemplary embodiments of present invention provides, for example, an improvement in the testing and diagnosis methods of integrated circuits by providing a method in which a portion of a test sequence is repeatedly recycled to allow data to be accumulated for analysis of the circuit operation and failed components. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other exemplary features, aspects and advantages will be better understood from the following detailed description of an exemplary embodiment of the invention with reference to the drawings, in which: FIG. 1 exemplarily shows the Picosecond Imaging Circuit Analysis (PICA) technique 100, as it might exemplarily be utilized in the present invention; FIG. 2 shows an exemplary flowchart 200 for PICA; FIG. 3 exemplarily shows a generic “standard” Linear Feedback Shift Register (LFSR) configuration 300; FIG. 4 exemplarily shows a “modular” Linear Feedback Shift Register (LFSR) configuration 400; FIG. 5 shows the exclusive-OR logic truth table 500 for a modulo-2 adder; FIG. 6 shows an exemplary LFSR circuit 600 having length n=3; FIG. 7 shows the state table 700 and state diagram 701 for the LFSR of FIG. 6; FIG. 8 exemplarily shows an LFSR configured as a Single Input Signature Register (SISR) 800; FIG. 9 exemplarily shows an LFSR configured as a Multiple Input Signature Register (MISR) 900; FIG. 10 exemplarily depicts an example of a 2-input 5-stage MISR example 1000; FIG. 11 exemplarily shows a typical LSSD structure 1100; FIG. 12 exemplarily shows a typical LSSD configuration 1200; FIG. 13 exemplarily shows a typical LSSD scan chain 1300; FIG. 14 exemplarily shows a configuration 1400 of two consecutive LSSD scan chain latches; FIG. 15 exemplarily shows a STUMPS (Self Test Using MISR and Parallel SRSG (Shift Register Sequencing Generating)) configuration 1500; FIG. 16 shows an exemplary embodiment 1600 of the present invention in which the L1/L2 latches are interconnected by a multiplexer; FIG. 17 exemplarily shows a configuration 1700 of two sequential Shift Register Latches (SRLs) as interconnected in accordance with the concepts of the present invention; FIG. 18 exemplarily shows a PICA timing setup 1800 for implementing the present invention; FIG. 19 shows an exemplary PICA diagnosis flow 1900 in accordance with the present invention; FIG. 20 illustrates an exemplary hardware/information handling system 2000 for incorporating the present invention therein; and FIG. 21 illustrates a signal bearing medium 2100 (e.g., storage medium) for storing steps of a program of a method according to the present invention. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION Referring now to the drawings, and more particularly to FIGS. 1-21, exemplary embodiments of the present invention will now be described. The present invention provides improvements on the concepts of two relatively new semiconductor diagnostic/testing techniques of LBIST (Logic Built-In-Self-Test) and PICA (Picosecond Imaging Circuit Analysis). Both of these concepts will be described in more detail below, but, in summary, LBIST is a scanning pattern technique to exercise an electronic circuit, and PICA is a technique in which circuit component operation is determined by detecting photons emission. The inventors have recognized that a basic problem encountered in testing complex devices that incorporate Built-in-Self-Test (BIST) and utilize the PICA concepts for diagnosis is that the very small amount of light emission makes it difficult to detect circuit operation. This problem is further complicated in a scan design environment where the pattern setup is loaded serially via the scan chain, thereby reducing the test stimuli application rate by several orders of magnitude. The inventors have further recognized that one possible solution to this diagnostic and characterization problem is to provide a simple means of generating a stimuli pattern that can be applied at high rates. Therefore, as will be better understood following a short discussion below on the concepts of BIST and PICA, a key aspect of the novel solution proposed herein is to modify the scan chain design such that the same critical stimuli pattern can be restored and re-applied on every cycle, thereby causing this critical pattern to be repeatedy many times to amplify the photonic emission detection ability during this critical pattern. However, before describing details of the novel techniques of the present invention, the following background information on PICA and BIST is provided for properly explaining and understanding the significance of the features of the exemplary embodiments of the present invention. PICA Overview PICA was developed to provide a fault localization tool which would be useable on flip chip mounted packages. The physics behind the technique are simple: as a transistor switches, a short burst of infrared light is emitted in the form of a photon. The PICA tool prototypes that have been built by the present Assignee allow one to resolve the arrival of the photon in X and Y, the area from which it was emitted, as well as T, the time during a test loop at which it was emitted. The emission thus provides one with a timing sequence, or movie, of all the switches occurring in the area of interest during a test pattern. Thus far, PICA has been used to diagnose failures in test chips and product at the present Assignee's facilities, ensuring fast debug of faulty processes and designs. The uses have been primarily for characterization of existing designs once they were available in hardware. More proactive uses of PICA have begun to occur, primarily in the form of measurements of gate delay on Complementary Metal-Oxide-Semiconductor (CMOS) technologies before their use, thus helping to improve models. Therefore, PICA provides the ability to know the real impact of a technology on a design's timing. Thus, this new circuit testing technique called Picosecond Imaging Circuit Analysis (PICA) captures weak, transient light pulses that are emitted by individual switching transistors through the backside of the chip. The use of PICA as a diagnostic and characterization tool is an emerging technology that can provide precise identification of defect location. It is important to locate defects precisely to improve both the speed and the likelihood that a defect can be analyzed to determine its root cause. Scientists have known since the 1980s that electrons emit light known as photons when they speed through field effect transistors (FETs), the building blocks of CMOS microchips. Microprocessors and memory chips can be made from CMOS circuits. The electrons move only when the CMOS circuits change from one state to another, switching “on” or “off”. Detecting these very faint light emissions can be used to monitor the switching of individual components of advanced CMOS chips. High-speed optical detectors can be used to monitor light emissions from simple high-speed circuits. A sophisticated detector can permit imaging and time resolving light emission from hundreds or thousands of devices on a chip simultaneously. The PICA technique produces “movies” of information flowing through complex chips, such as microprocessors. The technique was named “picosecond imaging circuit analysis” because the pulses of light last for only picoseconds (trillions of a second). Therefore, PICA is a method for recording time and location of photon emission and is positioned in the diagnostic process with other tools, such as e-beam (electron-beam probing), emission microscopy, and FIB (focused-ion-beam milling and repair). E-beam and emission microscopy provide information about the operation of circuitry that is not directly measurable by electrical testing or other forms of contact probing. FIB may be used to expose otherwise hidden circuit components for contact or contact-less probing or may be used to modify internal circuit connectivity as an aid to indirectly deducing a failure mechanism. PICA can be used for chip characterization including timing and clock skew. PICA can also be used for failure analysis such as for direct current (dc) and timing fails. Practically, since few photons are generated per switch, a high repetition rate is needed. Thus, PICA can only be used today practically for clocking, scanning, and memory self-testing. Chip innovations include increasing speed, decreasing size, and new packaging styles. These innovations drive changes in the technologies needed to test and debug the chips. Such tests are critical for identifying failures and faults in chip designs and manufacturing. In earlier chip generations, only one or two wiring layers interconnected the transistors, so that most of the transistors and wires were directly visible. More recently, however, the wiring on the chip is much more complex, leading to as many as eight levels of wiring. Bottom layers of wires and transistors are often almost completely covered by the upper layers of wires. As a result, traditional methods of measuring electrical activity on a chip are becoming impractical. PICA helps overcome this masking effect because of its capability to look at the transistors through the backside of a chip, where no metal wires get in the way. As mentioned, normally biased CMOS logic circuits emit photons for only a short period during the switching transient, allowing precise timing of individual transistors. Since lightly doped silicon substrates absorb a portion of the bandwidth of the emitted light from backside, samples to be analyzed are usually thinned first to improve emission intensity. The samples require no further preparation, and the chip package and socketing used throughout the measurement are the same as those used in electrical testing. The PICA system 100 exemplarily shown in FIG. 1 includes an imaging section 101 with a light-tight enclosure for the components 102, 103, 104 that detect the photon emission for the chip 105 mounted on test board 106. The timing section 110 is used to control the test sequence and analyze the photon emission image. Thus, in PICA, an automated tester 100 is used to stimulate the packaged device so that the transistors to be studied are switched repetitively. A standard infrared microscope 102, 103 is used to magnify and focus these devices onto the detection apparatus 104, which is exemplarily a thermoelectrically-cooled microchannel-plate (MCP) photomultiplier with a position-sensitive resistive anode, thereby determining both the location and the time of a photon emission. Two steps are employed to reduce the overall measurement time. First, the use of software or tester diagnostics minimizes the number of devices to be investigated. This information is used to select the magnification needed to spatially resolve the nearest transistors and to determine the number of measurements needed and their locations, given the field of view determined by the minimum usable magnification. The second step is selection of a test pattern that will rapidly cycle the circuits of interest through a desired switching state. FIG. 2 shows an exemplary flow chart 200 of the PICA diagnostic procedure. In step 201, a software diagnosis is exercised, during which it can be determined in step 202, which regions are likely to include failing gates and to generate, in step 203, the test patterns appropriate to exercise these regions are generated in step 202. The data collected from the measurements in step 204 is then processed in step 205 to provide insights into the device operation. Integration of the measured data, over time, creates an “emission photograph”, which shows the locations of all devices that switched throughout the test sequence. Selecting a single emission “spot” in the (x, y) plane of the collected image and plotting the time dependence of the emission intensity of the spot yield an optical waveform of the emission of the transistor or transistors within the spot. Layout-to-schematic mapping is used to relate optical waveforms to circuit schematic elements, and provides a means for comparison to circuit simulation. Circuit delays and logic evolution can be deduced from the waveform and circuit schematic information. A circuit stuck at a high or low value is detectable by comparing the predicted switching activity of a good device for a tester pattern to the measured switching activity for that pattern. A timing failure is located by comparing the simulated time of such switching to the measured time of the switching. Unfortunately, PICA cannot conventionally be used in certain testing situations because the weak, transient light pulses of the circuits of the chips are undetectable. For example, the LBIST test technique cannot use PICA. PICA techniques require high repetition rates of specific test patterns in order to get a sufficiently good image. Test patterns that have worked well with PICA are clocking patterns and scan patterns, both of which have high repetition rates. Conventional standard chip test technique such as LBIST does not have high repetition rates. Thousands of clocks must be applied to fully load a scan chain for each test pattern, and only one clock in 100 or more patterns may cause a fail. The duty cycle can easily be less than 1/100,000. Therefore, a circuit that fails during an LBIST test is simply not stimulated often enough to provide a PICA image, and PICA, although a valuable testing technique, cannot presently be used for detecting LBIST fails. The present invention provides a way to overcome this deficiency. BIST Overview This section briefly describes the general theory of operation and characteristics of the LFSR (Linear Feedback Shift Register). Although the LFSR has many uses in testing, communication, and encryption applications, the intent here is to use the LFSR as a source of pseudo-random binary sequences. The LFSR is a special configuration of a “linear circuit” into a special form of shift register or counter. These circuits require only a clock input, making them autonomous, and includes three basic logic components: 1) Latch or D-type flip-flop or a unit delay; 2) Exclusive-OR (XOR) or modulo-2 adder; and 3) Modulo-2 scalar multiplier. The LFSR circuit can take either of two equivalent or dual forms. FIG. 3 exemplarily shows a generic “standard” LFSR configuration 300, and FIG. 4 exemplarily shows the “modular” configuration 400. Each cell 301, 401 in each type has the same structure and is replicated to obtain the desired length n of the LFSR. The modulo-2 scalar multiplier (Ci) 302, 402 is either 0 or 1, which results in a connection or no-connection for the feedback signal. The modulo-2 adder 303, 403 is equivalent to an exclusive-OR logic circuit. The truth table 500 for a modulo-2 adder is shown in FIG. 5. FIG. 6 shows a simple example of an LFSR circuit 600 for length n=3. Some of the characteristics of a LFSR are its length or number of cells (n), the feedback configuration or values of Ci, and the initial state of the circuit. A “maximal length” LFSR is a circuit that cycles through 2n−1 unique states when initialized with a non-zero value. Of course, the maximum number of states of an n-length shift register is 2n, so a maximal length LFSR cycles through all the possible states except when initialized to zero. A non-maximal length LFSR also cycles through a sub-set of 2n states depending on the initial seed or initial value. For simplisticity and the purpose of this concept's explanation and effectiveness, only maximal length LFSR implementations are considered. The example in FIG. 6, therefore, shows a simple three stage (n=3) maximal length configured LFSR. In this case, the outputs from latches L2 (601) and L3 (602) are XORed and fed back to L1 (603). FIG. 7 shows the state table 700 and state diagram 701 for the LFSR of FIG. 6, having n=3, and show the sequence of states that this LFSR cycles through after being initialized to all “1”s at state So. The binary output sequence for this example is seven bits before it starts repeating (e.g., “1110010”, see 604 in FIGS. 6 and 702 in FIG. 7). One can easily extend the length of this simple circuit 600 to provide long sequences of binary pseudo-random numbers. For example, a 32-bit maximal length LFSR can cycle for over four billion states before repeating (e.g., 2′-1). Furthermore, by selecting the appropriate feedback parameters for the LFSR, one can generate unique sequences for each configuration. Maximal configuration tables for many values of n are readily available in many references or can be easily generated. Hereinbelow is briefly described the general theory of operation and characteristics of the LFSR when used for data compression as a signature generation register. There are many data compression algorithms and hardware implementations that can be used to generate signatures, but the use of an LFSR as a SISR (Single Input Signature Register) or MISR (Multiple Input Signature Register) has the advantage that it can be easily implemented in both hardware and software with low aliasing probability and a high degree of customization flexibility. The basic concept includes XORing one or more bits of input data on every Nth shift cycle of the LFSR. Typically, data is clocked into the LFSR on every shift cycle. The LFSR can be configured as a single input SISR or as a multiple input MISR. The single input configuration 800, exemplarily shown in FIG. 8, is usually used to serially compress long data bit strings, while the multiple input configuration 900, exemplarily shown in FIG. 9, can be used for simultaneous parallel compression of multiple bits groups such as a byte or word of input data. The data input(s) to the LFSR can be XORed at any point in of the recirculating shift register. Of course, the maximum number of possible single inputs for an N-length LFSR is N. If the number of inputs is greater than N, one could easily increase the length of the LFSR or XOR subsets of inputs for each MISR input. The output or signature of the SISR or MISR is usually the final state of the LFSR after all the data has been compressed or shifted into the LFSR. The length of the output signature can be the whole length of the LFSR or a truncated portion of N. The MISR or SISR can be further customized by selecting the initial seed or state prior to data compression, selecting the feedback configuration, input structure, number of shift cycles per data bit(s), and lengths of the LFSR. The length of the LFSR can be optimized for a particular system platform (i.e., 32-bits, 64-bits, 128-bits, 256-bits, or any bit length) or tailored for security robustness. FIG. 10 exemplarily depicts an example of a 2-input 5-stage MISR example 1000 with the associated state table for two input data sequences. Logic Scan Design & Test In this overview of the scan-based design and test methodology, one example will be discussed, although many of the basic concepts apply to other variations of scan designs. The Level Sensitive Scan Design (LSSD) methodology is a system design and a Design-for-Test (DFT) approach that incorporates several basic test concepts. In such a design, most of the storage elements of the device, such as latches or registers are concatenated in one or more scan chains and can be externally accessible via one or more serial inputs and outputs. Storage elements that are not in this category are usually memory or other special macros that are isolated and tested independently. Furthermore, this design methodology ensures that all logic feedback paths are gated by one or more of these storage elements, thereby simplifying a sequential design into subsets of combinational logic sections, as exemplarily shown in FIG. 11 and FIG. 12. These basic design concepts, in conjunction with the associated system and scan clocking sequences, greatly simplify the test generation, testing, and diagnosability of very complex logic structures. Every latch can be used as a pseudo Primary Input (PI) and as a pseudo Primary Output (PO), in addition to the standard PIs and POs, to enhance the stimulation and observability of the device being tested or diagnosed. As exemplarily shown in FIGS. 13 and 14, LSSD latches 1300 are typically implemented in a L1/L2 configuration where the L1 or master latch 1301 has two data ports (“SRI” and “Data”) and may be updated by either a scan clock (a) or a functional clock (c1). The L2 or slave latch 1302 has only one clock input (b-clk(c2)) and that clock is out of phase with both L1 clocks. Scanning is done using separate A and B clocks. LBIST Overview Two basic components of the LBIST structure 1500 shown in FIG. 145 are a Linear Feedback Shift Register (LFSR) 1501 and a Multiple Input Signature Register (MISR) 1502. The LFSR serves as a pseudo random pattern generator that provides the stimuli for the logic being tested, while the MISR is utilized to generate a unique signature representing the responses from the logic. Ideally, the signature for each failing device is different from the signature of a good device after a predefined number of test cycles. The configuration of the scan chain in the LBIST test mode is partitioned into several sub-chains of approximately the same length. These chains are loaded and unloaded serially for each LBIST test. Once in LBIST mode, the scan chain is reconfigured into a number of parallel sub-chains, as exemplarily shown in FIG. 15. The pseudo random data loaded in parallel into each sub-chain is supplied by the LFSR and used as test stimuli. Similarly, the state of all latches in the sub-chains are unloaded serially into the MISR forming a signature representing the compressed data. Each LBIST test cycle, in addition to the loading and unloading of the sub-chains, requires timed application of system clocks to launch the test vector from these latches through the combinational logic and capture the resulting response in the receiving latches. Since a typical system design may include several system clocks and various path delays, the clock test sequence and timing set-up may be applied multiple times with different clock combinations and timings. Typically, this is accomplished by an on-product clock generation (OPCG) function and LBIST control. An LBIST test interval in turn includes a relatively large number of these load/unload sequences followed by the system clock cycle. At the end of the interval, the MISR contents or signature is unloaded and compared to an expected signature. Several signature intervals may be applied to achieve the desire test coverage. This LBIST methodology is an effective Design for Test (DFT) that can support structural test from the chip level, various package levels, up to the system level. Some of the benefits associated with this approach include relatively low test data volumes, minimal VLSI test system requirements, at-speed test rates, and extendibility to system test. Recycle Scanning of the Present Invention Therefore, given the above technical background information and as mentioned above, a key aspect of the present invention is to modify the scan chain design such that the same critical stimuli pattern can be restored and re-applied on every cycle, thereby causing this critical pattern to be repeatedy many times to amplify the photonic emission detection ability during this critical pattern. This pattern-restore-function can be accommodated by a simple SRL design modification described below (e.g., see FIG. 16). This function is referred to as a “back-shift L2 restorable latches”. In addition to the scan chain back-shift modification, the complete solution of the present invention also uses existing BIST diagnostic methodologies to isolate the critical pattern and a custom timing sequence to setup and execute the PICA acquisition loop. The novel concepts are based on the LBIST test methodology, a back-shift-restore scan chain design, and PICA diagnostic techniques that are executed in two test phases. The first phase utilizes the LBIST test and diagnostic methods to identify the failing tester loop and isolate the associated failing latches, while the second phase utilizes a modified LBIST clocking sequence in conjunction with the PICA tool to diagnose the fault to the failing net, logic block, or device. These two phases are exemplarily summarized in the following steps. Phase I: 1. A LBIST test sequence is executed (skewed load OPCG clocking sequence); 2. Failing tester loop(s) are identified, using binary search, etc.; and 3. Failing Representative Measurable Latch(es) (RML(s)) for each identified failing tester loop are identified. Phase II: 1. The LBIST test (or functional patterns) is executed up to the failing tester loop (same as in Phase I); 2. The failing tester loops random stimuli is loaded into the L1 latches (this step would be normally done during the previous tester loop channel scan load/unload operation and may not be required); 3. A tight loop is applied on a single clocking sequence by continuously applying launch clocks (c2-clks) and back-shift-restore; 4. While looping at high rates on the above special clocking sequence, the PICA tool is used to trace back from the failing RML to the defect location; and 5. The same clocking sequence can be used to loop on a functional pattern, after sequencing to the failing pattern. This basic concept applies to structural as well as functional test patterns diagnostics and can be extended to critical signal path characterization. Furthermore, the concept can be used to diagnose stuck-at scan chains and for delta-I noise analysis. FIG. 16 exemplarily depicts the basic L2 restorable function for a typical LSSD L1/L2 latch 1600, as modified for the present invention. The restore function is achieved by providing an alternate data path to the L2 latch. In the example, this is achieved by a multiplexor (MUX) 1601 or other selector block that, in the normal scan mode selects the output of the L1 latch from the same latch, while in the PICA acquisition mode selects the output of the L1 from the next RSL (Representative Scannable Latch) of the scan chain. The MUX selection is controlled by a global control signal (SEL). FIG. 17 shows the configuration 1700 of two interconnected SRLs 1701, 1702 with the associated back-shift data path. A somewhat different approach to the MUX 1600 may also use a dual data port L2 latch and select the port by another clock similar to the b/c2-clock. Also, not all RSLs in a design need to be modified to support the restore function, since a partial implementation of critical areas may be sufficient in some applications and test methodologies. Besides additional silicon real estate due to the L2 restore function, also to be considered are the additional delay introduced in the L1/L2 system path, the loading on the L1 output for the restore feedback, and the associated wiring. These impacts can be minimized by integrating the function within the RSL macro design. FIG. 18 exemplarily illustrates the timing diagram 1800 for a typical PICA test. The three cycles 1801, 1802, 1803 on the left are part of the pattern setup operation. The data from SRI is loaded via the shift register to all the RSLs for a particular test mode. The last cycle in the SR load sequence is to apply a single a-clock to setup a skewed load. The skewed load allows for the next b/c2-clock to launch a transition through the combinational logic. In a normal test mode, the results from the transition through the logic are typically captured in the L1 latch by applying a c1-clock. Once the critical pattern has been skew-loaded in the scan chain, the PICA acquisition cycle 1804 can be executed in a tight loop at high rates. The timing for this cycle includes first restoring the L2 latch with the next RSL L1 logic value. This is feasible since the next RSL L1 has been loaded to the same state as the L2 by the skewed-load. Note that this will be true as long as the C1-clock to the L1 is not pulsed. The second half of the cycle launches the transitions (e.g., see 1805) by applying the b/c2-clock through the combinational logic. The PICA tool is used during this portion of the cycle to observe these transitions in time and space. Since the L1s are not clocked during this sequence, re-executing the cycle allows for restoring the L2 and reapplying the same transitions as often as necessary for an effective PICA data acquisition and subsequent analysis. FIG. 19 is an exemplary two-phased process flow describing the overall concept. Phase I (e.g., 1901) include the steps 1901.1 involved in a typical LBIST diagnostic process to first identify, in step 1901.2, one or more failing or critical patterns or tester loops (T/Ls). The next step 1901.3 is to further identify the specific failing paths or RMLs. This information is then used to setup the individual critical pattern conditions for Phase II (e.g., PICA data acquisition). Although there are many techniques used in BIST diagnostics, such as binary searches, selective signature generation, etc., the details if these methods can be found in references outside the scope of this application. The steps 1902 of Phase II utilize the results from the LBIST diagnostics to set up the critical pattern and then execute that pattern is a tight loop while collecting backside emission data. The setup includes, in step 1902.1, of executing LBIST up to the pattern of interest, including the skewed load. Once the pattern is set up, the mode is switched to a “back-shift L2-restore & PICA acquisition” looping cycle 1902.3. The looping pattern 1902.3 is executed for as long as necessary for proper PICA timing and spatial resolution. PICA waveforms are then analyzed to determine the circuit functionality and timing characteristics for the output Physical Failure Analysis (PFA). Although the LSSD scan chain and the LBIST test methodology has been used as an example for a specific embodiment of the idea, the basic concept can be extended to other types of scan designs and diverse BIST designs. Furthermore, the concept not only applies to structural test, but can also be used in a functional test environment with latch restore capability. Exemplary Hardware Implementation FIG. 20 illustrates a typical hardware configuration of an information handling/computer system in accordance with the present invention and which preferably has at least one processor or central processing unit (CPU) 2011. The CPUs 2011 are interconnected via a system bus 2012 to a random access memory (RAM) 2014, read-only memory (ROM) 2016, input/output (I/O) adapter 2018 (for connecting peripheral devices such as disk units 2021 and tape drives 2040 to the bus 2012), user interface adapter 2022 (for connecting a keyboard 2024, mouse 2026, speaker 2028, microphone 2032, and/or other user interface device to the bus 2012), a communication adapter 2034 for connecting an information handling system to a data processing network, the Internet, an Intranet, a personal area network (PAN), etc., and a display adapter 2036 for connecting the bus 2012 to a display device 2038 and/or printer 2039 (e.g., a digital printer or the like). In addition to the hardware/software environment described above, a different aspect of the invention includes a computer-implemented method for performing the above method. As an example, this method may be implemented in the particular environment discussed above. Such a method may be implemented, for example, by operating a computer, as embodied by a digital data processing apparatus, to execute a sequence of machine-readable instructions. These instructions may reside in various types of signal-bearing media. Thus, this aspect of the present invention is directed to a programmed product, comprising signal-bearing media tangibly embodying a program of machine-readable instructions executable by a digital data processor incorporating the CPU 2011 and hardware above, to perform the method of the invention. This signal-bearing media may include, for example, a RAM contained within the CPU 2011, as represented by the fast-access storage for example. Alternatively, the instructions may be contained in another signal-bearing media, such as a magnetic data storage diskette 2100 (FIG. 21), directly or indirectly accessible by the CPU 2011. Whether contained in the diskette 2100, the computer/CPU 2011, or elsewhere, the instructions may be stored on a variety of machine-readable data storage media, such as DASD storage (e.g., a conventional “hard drive” or a RAID array), magnetic tape, electronic read-only memory (e.g., ROM, EPROM, or EEPROM), an optical storage device (e.g. CD-ROM, WORM, DVD, digital optical tape, etc.), paper “punch” cards, or other suitable signal-bearing media including transmission media such as digital and analog and communication links and wireless. In an illustrative embodiment of the invention, the machine-readable instructions may comprise software object code. While the invention has been described in terms of exemplary embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the appended claims. Further, it is noted that Applicants' intent is to encompass equivalents of all claim elements, even if amended later during prosecution. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention generally relates to testing and diagnosis of failures in integrated circuits. More specifically, a clocking signal in a Built-In Self Test (BIST) sequence is interrupted to permit a second clocking cycle to repeatedly recycle through a particular section of the BIST. In an exemplary embodiment, activity in the circuit is determined by detecting photons emitted during this second clocking cycle. 2. Description of the Related Art The rapid densification of VLSI (Very Large Scale Integrated) circuit devices, associated with high speed circuit performance, and relatively short time-to-market, has driven the need to rapidly characterize and diagnose complex designs early in the product cycle. Concurrently, conventional characterization test tools and diagnostic techniques, already somewhat limited, are quickly becoming obsolete. These problems in turn show the need for a novel test and diagnostic methodology that combines new Physical Failure Analysis (PFA) tools with integrated test and diagnostics support built-in the semiconductor device. Some of the built-in test and diagnostic functions may be based on several Design for Test (DFT) techniques such as Level Sensitive Scan Design (LSSD), Logic Built-In-Self-Test (LBIST), Array Built-In-Self-Test (ABIST), On-product-clock-generation (OPCG), and others. Thus, a need exists so that testing tools and diagnostic methods keep pace with the newer techniques of semiconductor design and fabrication. | <SOH> SUMMARY OF THE INVENTION <EOH>In view of the foregoing, and other, exemplary problems, drawbacks, and disadvantages of the conventional system, it is an exemplary feature of the present invention to provide a novel technique for integrated circuit testing and diagnosis. It is another exemplary feature of the present invention to overcome a problem in a testing technique in which emitted photons are detected to determine circuit activity. It is another exemplary feature of the present invention to provide a technique that can be used to overcome a problem in a testing technique in which circuit activity is shielded by overlying layers of wiring on a chip. It is another exemplary feature of the present invention to provide a method in which photon emission can be amplified in a Built-In Self Test (BIST) process by repeatedly recycling through a sequence of the BIST test. It is another exemplary feature of the present invention to provide a method in which a normal clocking cycle of a BIST test is interrupted and a second clocking cycle is used to repeatedly exercise a sequence of the BIST test. To achieve the above exemplary features and others, in a first exemplary aspect of the present invention, described herein is a method of at least one of testing, diagnosing, and monitoring an operation of an electronic circuit, including interrupting a clock signal used to provide a clocking for a normal operation of the circuit and using a second clock signal to repeatedly cycle through a predetermined cycle of operations for the circuit. In a second exemplary aspect of the present invention, described herein is a structure to execute the above-described method. In a third exemplary aspect of the present invention, described herein is also a signal-bearing medium tangibly embodying a program of machine-readable instructions executable by a digital processing apparatus to perform the above-described method. In a fourth exemplary aspect of the present invention, described herein is also an electronic circuit including at least one scan chain of latches and a mechanism to allow a data flow in the scan chain to be reversed in direction. In a fifth aspect of the present invention, described herein is an apparatus having at least one component having at least one electronic circuit that includes at least one scan chain of latches and a mechanism to allow a data flow in the scan chain to be reversed in direction. In a sixth aspect of the present invention, also described herein is a method of at least one of testing, diagnosing, and monitoring an operation of an electronic circuit, including mounting the electronic circuit such that a photodetector can detect photon emissions due to an operation of the electronic circuit, exercising the electronic circuit with a built-in-self-test sequence, determining a position in the built-in-self-test sequence where a failure occurs, and recycling a plurality of times through a sequence of the built-in-self-test sequence at the determined position in the built-in-self-test, the photodetector detecting a photon emission due to activity of the electronic circuit during the recycling, the recycling thereby causing an amplification effect of the photon emission during the recycling. The exemplary embodiments of present invention provides, for example, an improvement in the testing and diagnosis methods of integrated circuits by providing a method in which a portion of a test sequence is repeatedly recycled to allow data to be accumulated for analysis of the circuit operation and failed components. | 20040219 | 20071211 | 20050825 | 95417.0 | 0 | TU, CHRISTINE TRINH LE | METHOD AND STRUCTURE FOR PICOSECOND-IMAGING-CIRCUIT-ANALYSIS BASED BUILT-IN-SELF-TEST DIAGNOSTIC | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,780,967 | ACCEPTED | ROM-embedded debugging of computer | A debugger program, embedded in a ROM of a computer, operates on instructions of a target process executed by the computer. | 1. A method for debugging a computer system, comprising: initiating a process in the computer system, the process including instructions; launching a debugger program that is embedded in a ROM of the computer system; executing at least part of the instructions; and the debugger program operating on at least part of the executed instructions. 2. A method as defined in claim 1, further comprising: the debugger program capturing a trace of the at least part of the executed instructions. 3. A method as defined in claim 2 wherein: the computer system includes a port connected to a monitoring system; and further comprising: outputting the captured trace through the port to the monitoring system. 4. A method as defined in claim 1, wherein: the process comprises a boot process; the instructions comprise boot instructions stored in the ROM of the computer system; and the debugger program is launched from within the boot process. 5. A method as defined in claim 1, further comprising: stopping the execution of the instructions at a first break point; the debugger program setting a second break point in the instructions; and continuing the execution of the instructions. 6. A method as defined in claim 5, further comprising: the debugger program disassembling a current instruction of the instructions; determining a length of the current instruction, the length of the current instruction indicating a start point for a next instruction of the instructions; and setting the second break point at the start point of the next instruction. 7. A method as defined in claim 1, further comprising: interrupting the execution of the instructions at a current instruction; the debugger program operating on the current instruction by disassembling the current instruction; and executing the current instruction. 8. A method as defined in claim 7, further comprising: before executing the current instruction, determining a location of a next instruction of the instructions; and after executing the current instruction, interrupting the execution of the instructions at the next instruction. 9. A method as defined in claim 1, further comprising: setting a switch within the computer system; and launching the debugger program in response to detecting the set switch. 10. A method as defined in claim 1, further comprising: setting a break point within the process according to a location specified in a map of the process contained in the debugger program. 11. A computer system, comprising: at least one processor; a read-only memory (ROM) connected to the processor; a target process having instructions capable of being executed by the processor; and a debugger program embedded within the ROM and capable of being executed by the processor to operate on at least part of the instructions of the target process. 12. A computer system as defined in claim 11, wherein: the target process comprises a boot process. 13. A computer system as defined in claim 11, wherein: the debugger program operates on the at least part of the instructions by capturing a trace of the execution of the at least part of the instructions. 14. A computer system as defined in claim 11, wherein: the debugger program further operates on the at least part of the instructions by disassembling the at least part of the instructions. 15. A computer system as defined in claim 11, wherein: the debugger program operates on a current instruction of the target process and sets a break point at a next instruction of the target process to be operated on. 16. A computer system as defined in claim 11, further comprising: a switch that when set enables launching of the debugger program; and wherein the target process launches the debugger program upon detecting that the switch is set. 17. A computer system as defined in claim 11, further comprising: an interrupt flag that when set causes an interruption of execution of the target process; and wherein, upon interruption of the execution of the target process, the debugger program operates on a current instruction of the target process. 18. A computer system as defined in claim 11, further comprising: a map of the target process embedded in the debugger program and specifying locations of parts of the target process. 19. A computer debugging system, comprising: a target computer; a monitoring system connected to the target computer; a data storage device in the monitoring system; a read-only memory (ROM) in the target computer; a target process having instructions executable in the target computer; and a debugger program embedded in the ROM and executable in the target computer to generate data on the execution of at least part of the instructions of the target process and to transfer the data to the monitoring system for recording in the data storage device. 20. A computer debugging system as defined in claim 19, further comprising: a disassembler embedded in the ROM and executable in the target computer to disassemble the at least part of the instructions of the target process. 21. A computer debugging system as defined in claim 19, wherein: the data on the execution of the at least part of the instructions of the target process comprises a trace capture of the at least part of the instructions. 22. A computer system, comprising: a read-only memory (ROM) means for storing computer control instructions; a means for executing a target process; a ROM-embedded means for interrupting the execution of the target process at a current instruction; a ROM-embedded means for disassembling the current instruction; a means for executing the current instruction; and a ROM-embedded means for capturing a trace of the current instruction and of results of the execution of the current instruction. 23. A computer system as defined in claim 22, further comprising: a means for transferring the captured trace to an external means for storing the captured trace. 24. A computer system comprising: a read-only memory (ROM); a target process having executable instructions; and a debugger program embedded within the ROM and having a disassembler and a trace capturer; and wherein: the debugger program interrupts execution of the target process at some of the instructions; the disassembler disassembles at least some of the instructions at which the execution of the target process is interrupted; and the trace capturer captures a trace of at least some of the disassembled instructions. 25. A computer system as defined in claim 24, wherein: the target process comprises a boot process stored within the ROM and having instructions that boot the computer system when the boot process executes. 26. A computer system as defined in claim 24, further comprising: a port that can be connected to a monitoring system; and wherein the debugger program outputs the captured trace through the port to the monitoring system. 27. A computer system as defined in claim 24, wherein: the debugger program disassembles a current instruction of the target process, determines a length of the current instruction, and sets a break point at a next instruction of the target process. 28. A computer system as defined in claim 24, wherein: the computer system executes the current instruction, encounters the break point at the next instruction, and jumps to the debugger program with the next instruction as a new current instruction. 29. A computer system comprising: a switch; a target process having executable instructions; and a debugger program; and wherein: when the switch is off, the debugger program cannot be launched; and when the switch is on, the debugger program can be launched to interrupt execution of the target process at some of the instructions and operate on at least some of the instructions at which the execution of the target process is interrupted. 30. A method for debugging a target process executing on a computer system, comprising: launching a debugger program from a read-only memory (ROM) of the computer system, the ROM having a boot process and the debugger program embedded therein, the debugger program having a disassembler and a trace capturer; interrupting execution of the target process at an instruction; the disassembler disassembling the instruction; and the trace capturer capturing a trace of the instruction. 31. A method as defined in claim 30, further comprising: executing the instruction; and interrupting the execution of the target process after the instruction. 32. A method as defined in claim 30, wherein: the target process comprises the boot process. 33. A method for debugging a target process executing on a computer system, comprising: setting a switch within the computer system to one of an on state and an off state; when the switch is set to the off state, preventing execution of a debugger program; and when the switch is set to the on state: launching the debugger program; interrupting execution of the target process at an instruction; and the debugger program operating on the instruction. | BACKGROUND A processor in a computer operates on instructions with no indication of what is happening internally, except for external signals on I/O pins. The contents of registers and cache within the processor may be assumed, if the processor is functioning properly, but are usually unknown, unless a specific request is made to read such information. Since the internal functions of the processor are effectively hidden, if a hardware or software error occurs during execution of a program, it is often difficult or time-consuming to determine whether the cause of the error is in the processor, in some other component of the computer or in the program instructions. Computer program execution tracing is a useful technique for locating hardware and software errors in the performance of a computer by generating, or “capturing,” a “trace” of executed program instructions. The program execution trace may also log certain events as they occur, a so-called event-based profiling technique. The program execution trace is essentially a listing of the executed instructions, called subroutines and accessed resources and sometimes the results thereof. This technique may be used, for example, in a power-on self test (POST) of the computer to discover errors in the performance of the processor, the firmware or the system board. This technique may also be used after POST to discover errors in programs or peripheral devices operating in the computer. Some variations in program execution tracing use logic analyzers, in-target probes (ITPs) or in-circuit emulators (ICEs) to view executed instructions or to generate the program execution traces. Each of these devices has various benefits or uses. However, in addition to the cost of these devices, each also has limitations. The logic analyzer monitors signals within the computer, such as signals on a bus, the I/O pins of a processor or another component in the computer. The logic analyzer can capture the state of the signals at any given moment and can capture a trace of the signals to record changes in the state of the signals over a period of time. The logic analyzer does not, however, control the computer or issue commands to get specific data. Thus, a significant limitation in logic analyzers is that the captured traces are dependent on the external signals of the processor, or other component, being monitored. The internal workings of the processor, such as the state of the registers or the cache, remain hidden. Thus, when the internal cache of the processor is enabled, many instructions cannot be captured. Additionally, significant manual translation and filtering must be done to correlate the captured signal data to actual instructions executed. An ITP or an ICE enables debugging of the computer, the processor or the program during hardware/software development not only by monitoring the I/O pins or bus signals, but also by controlling the processor, bus or other component to which it is connected. Thus, not only does the ITP or ICE intercede between the desired component (e.g. the processor) and circuit board to intercept and/or sense some or all of the signals from the component, but the ITP or ICE can also issue commands to the component. For example, the ITP or ICE can request data from the registers of the processor in addition to displaying a current state of the signals on the I/O pins. The ITP or ICE cannot, however, access the cache, and the less expensive ITPs or ICEs cannot capture a trace of the executed instructions. The ITP or ICE can be used to manually step through each instruction, but this process is very slow. Additionally, some ICEs have some trace capture ability that only runs off a particular bus that the ICE is monitoring, so the ICE captures only the bus activity. Each of these devices (the logic analyzers, ITPs and ICEs) is used within a laboratory setting. In other words, they are used to debug computers, computer components and programs under development by a manufacturer or that have reported errors in the field and have been returned by a consumer. Due to the cost and size of the logic analyzers, ITPs and ICEs, these devices are almost never taken out of the laboratory setting to analyze a computer, component or program in the field. In order to view the contents of the cache and other internal workings of the processor, special “bond-out” versions of integrated circuit chips have been produced. The bond-out chips resemble the standard versions of their integrated circuits, but have special pins, and sometimes complete buses, that make “internal” signals available at special external bond-out interfaces. The bond-out features, however, take up valuable space in, and can affect the operation of, the integrated circuit. Additionally, special devices and programs are needed to decode and give meaning to the signals provided at the special bond-out interfaces. Another technique for monitoring internal functions of the processor involves an “on-chip trace cache” and supporting circuitry within the integrated circuit of the processor. Trace information is captured in the on-chip trace cache during operation of the processor. Afterwards, the captured information can be downloaded and analyzed. This technique, however, takes up valuable space within the integrated circuit. Another technique to analyze the performance of a target computer, but which does not necessarily incorporate additional devices (e.g. the logic analyzers, ITPs and ICEs) or additional on-chip circuitry, is “instrumented source code.” In this technique, executable “tag statements” are inserted into various branches and locations of source code, thereby “instrumenting” the source code. After the source code has been compiled and linked, the tag statements are executed along with the rest of the code. As each tag statement is executed, it performs an operation that can be either detected by an analysis device or recorded within the target computer for later examination. For example, each tag statement may write a value to different addresses so that the contents of the addresses provide an indication of which tag statements were executed and in what order. The general flow of the software is thus indicated by the contents of the addresses. SUMMARY According to a particular embodiment of the present invention, a method for debugging a computer system comprises initiating a process in the computer system, the process including instructions; launching a debugger program that is embedded in a ROM of the computer system; executing at least part of the instructions; and the debugger program operating on at least part of the executed instructions. According to another embodiment of the present invention, a computer system comprises a processor; a read-only memory (ROM) connected to the processor; a target process having instructions capable of being executed by the processor; and a debugger program embedded within the ROM and capable of being executed by the processor to operate on at least part of the instructions of the target process. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a computer debugging system according to an embodiment of the present invention. FIG. 2 is a block diagram of a target computer system according to an embodiment of the present invention and incorporated in the computer debugging system shown in FIG. 1. FIG. 3 is a simplified flow chart of a generalized procedure according to an embodiment of the present invention for debugging a process in the target computer system shown in FIG. 2. FIG. 4 is a simplified flow chart of a generalized procedure according to an embodiment of the present invention for capturing a continual trace of at least a portion of a process in the target computer system shown in FIG. 2. FIG. 5 is a simplified flow chart of a generalized procedure according to an embodiment of the present invention for capturing a single-step trace of at least a portion of a process in the target computer system shown in FIG. 2. FIG. 6 is a simplified flow chart of a generalized procedure according to an embodiment of the present invention for executing at least a portion of a process in the target computer system shown in FIG. 2 without capturing a trace of the executed portion. DETAILED DESCRIPTION A computer debugging system 100 incorporating an embodiment of the present invention is shown in FIG. 1. The computer debugging system 100 generally includes a target computer 102 and a monitoring system 104. The target computer 102 is preferably a general-purpose X86 processor-based computer system, or any other appropriate computer system, for which hardware and/or software is being developed and/or debugged. The monitoring system 104 is also preferably an appropriate general-purpose computer system. The target computer 102 includes a ROM-embedded debugger program 106 for debugging the hardware and/or software, such as a target process 108 and any hardware with which the target process 108 may operate. The debugger program 106 is ROM-embedded, so the debugger program 106 can be launched at an appropriate point during a “boot,” or power-on self-test (POST), process as well as at any other desired time. Thus, the target process 108 may be the boot process as well as any other process running in the target computer 102. In other words, the debugger program 106 can be used to debug any portion of the boot process following the launch of the debugger program 106 as well as any other process launched after completion of the boot process. In a particular embodiment, the boot process preferably performs only a minimum portion thereof to enable the debugger program 106 to function before the debugger program 106 is launched, so that as much of the boot process as possible can be subjected to the debugger program 106. Additionally, the target computer 102 also preferably includes a terminal 110 (such as, but not limited to, a VT100 terminal) for communicating with the monitoring system 104. In this manner, any data generated by the debugger program 106 can be quickly transferred to the monitoring system 104, instead of using resources within the target computer 102 to save and manage the data. Additionally, if stored in the target computer 102, the data could be lost upon a crash of the target computer 102. The monitoring system 104 preferably includes at least sufficient hardware and/or software to assist the debugger program 106. Such hardware and software preferably includes a terminal 112, a storage device 114, a data management program 116 and optional data for controlling (control data 118) the debugger program 106. The terminal 112 (such as, but not limited to, a VT100 terminal) communicates with the target computer 102 to receive the data generated by the debugger program 106. The data management program 116 reads the data coming in through the terminal 112 and stores the data in the storage device 114. The control data 118 preferably includes files and data, such as previously prepared scripts, which may be transferred through the terminal 112 to the target computer 102 to assist the debugger program 106. Thus, a user may prepare a script of a series of commands within the control data 118 for the debugger program 106 to download and perform. In operation, the user preferably connects the target computer 102 and the monitoring system 104, sets up the monitoring system 104 (e.g. by launching the data management program 116), creates any desired control data 118 and then launches the debugger program 106. The debugger program 106 is preferably launched during execution of the target process 108 or by the target process 108 or before launching the target process 108. For example, if the target process 108 is the boot process, then the debugger program 106 is preferably launched during the boot process and by the boot process. Once the target process 108 and the debugger program 106 are running, the user preferably issues commands to the debugger program 106 to operate on instructions of the target process 108, to display at least some of the data to the user and to send the data to the monitoring system 104. Exemplary commands and operations are described below. The user also preferably operates the monitoring system 104 to view, analyze, manipulate and search the data as needed. According to an embodiment as shown in FIG. 2, the target computer 102 generally includes, among other components, one or more processors 120, a memory subsystem 122, a ROM 124, a port 126 and a switch 128 connected together by one or more bus systems 130 and 132. For example, according to a more particular embodiment, the target computer 102 shown may be an X86-compatible-processor-based personal computer or server, such as a computer with an Intel Pentium™ processor. The processor 120 executes software using a variety of internal components including a cache memory 134 and a set of registers 136, among other components. The memory subsystem 122 provides a main computer memory to support the processor 120. The ROM 124 generally stores the boot process 138 and the debugger program 106. The debugger program 106 generally includes, among other functions, embedded trace code 140 and an embedded disassembler 141. The port 126, such as a serial port, provides a physical connection point for the connection to the monitoring system 104. The switch 128, such as a dip switch on a motherboard in the target computer 102, physically enables and disables the debugger program 106. According to a particular embodiment, the boot process 138 preferably launches the debugger program 106 whenever the boot process 138 determines that the switch 128 is set to enable the debugger program 106, but does not launch the debugger program 106 when the switch is not set to enable the debugger program 106. In this manner, the user can select whether to use the debugger program 106 before the user boots or turns on the target computer 102. If selected, then the debugger program 106 will be launched during and by the boot process 138 after the boot process 138 reads the state of the switch 128. The boot process 138 will then halt, and the user will preferably be presented with a command prompt. The user can then enter commands (described below) to control the operations of the debugger program 106. According to another particular embodiment, the switch 128 may enable the debugger program 106 after the target computer 102 has booted and is ready to run other programs as the target process 108 (FIG. 1). Thus, the switch may be set at any time in order to debug any target process 108. Additionally, the debugger program 106 may be used not only in a laboratory setting or during initial development of the target computer 102, but also in the field to debug a problem encountered any time after the target computer 102 has been developed and a production version has been provided to a customer. To effectively hide the debugger program 106 from the customer, however, the switch 128 may be set to disable the debugger program 106 in the production version of the target computer 102. Additionally, if the monitoring system 104 is a notebook computer, then it is not so inconvenient or costly to take it into the field as it would be to take an ITP, ICE or logic analyzer. Instead, a service call to run the debugger program 106 at the customer's site can be practical to respond to a problem in the production version reported by the customer. A service technician at the customer's site can then set the switch 128 in the production version of the target computer 102 to enable the debugger program 106, connect the production version of the target computer 102 to the (notebook computer) monitoring system 104, and proceed to debug the problem in the production version of the target computer 102. In the case of the boot process 138 being the target process 108, the debugger program 106 preferably has an embedded “map” 142 of the boot process 138. The boot process map 142 preferably includes at least some labels and addresses specifying locations of parts 143 of the boot process 138. The boot process map 142 enables the debugger program 106 to disassemble specific portions of the boot process 138 and to set break points at specific points within the boot process 138 without the user knowing the actual addresses of the portions of and points within the boot process 138. The commands that are available for the user to enter at the command prompt of the debugger program 106 preferably include, but are not limited to, the following exemplary commands. For example, one command (a continual-trace command) preferably causes each instruction of the target process 108 to be executed followed by an interruption. Each interruption allows the debugger program 106 to disassemble (with the embedded disassembler 141) and capture a trace (with the embedded trace code 140) of the current instruction. The captured trace preferably includes the disassembled instruction, which is transferred to the monitoring system 104 for storage. Every instruction that is executed, therefore, can be captured, even if the processor 120 is operating on instructions stored in the cache memory 134. In a particular embodiment involving a target computer 102 having an X86-compatible processor, the interruption of the target process 108, for example, is caused by interrupt 3 (INT3) break points. The trace code 140 preferably sets each INT3 break point at the start of the next instruction immediately following the current instruction before the current instruction is executed. The disassembly of the current instruction identifies the current instruction and its length (e.g. in bytes, words, dwords, etc. of opcode and operands), which enables the trace code 140 to determine the starting point of the next instruction. The identification of the current instruction also enables the trace code 140 to determine whether there is more than one possible next instruction, e.g. for a current instruction that is a conditional jump. In this case, INT3 break points are set at the start of every possible next instruction. Each INT3 break point is set, for example, by copying the first byte of each next instruction to a secure memory location and then writing an INT3 opcode in place of the first byte. The debugger program 106 then sets a “trace flag” to indicate that the continual trace is being performed and then jumps to the target process 108 to allow execution of the current instruction. After execution of the current instruction, the INT3 break point is encountered at the start of the next instruction, which causes execution of an INT3 handler. Thus, at the initial launch of the debugger program 106, the debugger program 106 preferably “hooks” the INT3 handler, so the INT3 handler will transfer execution back to the debugger program 106. Upon returning to the debugger program 106 through the INT3 handler, the previous next instruction is now a new current instruction. The debugger program 106 restores the first byte of the new current instruction (and any other previously possible next instruction). The debugger program 106 proceeds, as above, with disassembling and capturing a trace of the new current instruction. If the trace flag is set, indicating that the continual trace is being performed, then another INT3 break point is set at the start of a new next instruction and the new current instruction is executed as above. Another command may perform most, if not all, of the functions of the continual-trace command, but also transfer a copy of the contents of the registers 136 along with the captured trace of the disassembled instruction to the monitoring system 104 for storage. In either case, the debugger program 106 continues to capture a trace of the execution of the target process 108 until the target process 108 terminates normally or the debugger program 106 encounters a “hard” break point or until the target computer 102 “hangs,” or “crashes.” Another command, therefore, preferably allows the user to set one or more hard break points at one or more desired addresses (e.g. a specified segment and offset) within the target process 108. The hard break points stop the execution and trace capture of the target process 108 at a desired point and return control of the target computer 102 to the command prompt of the debugger program 106. Additionally, other commands preferably clear one or more of the hard break points and/or store the hard break points for later or repeated usage. In case the target computer 102 hangs during a trace capture, the last executed instruction of the target process 108 (presumably the instruction that caused the hang) is the last stored instruction in the storage 114 of the monitoring system 104. The user can, thus, view the last instruction of the captured trace and possibly determine the cause of the hang. Another command preferably starts the continual-trace, described above, but without capturing a trace of subroutines and/or functions called by a higher-level routine. In this manner, valuable processing time is not taken up with capturing a trace of subroutines and/or functions that are known to be good. Instead, a trace is quickly captured of only the higher-level routine. This trace capture provides a simplified view of the execution of the target process 108. Another command preferably causes a trace capture and execution of one instruction of the target process 108 at a time, so the user can carefully single-step through the execution of the target process 108 to try to locate a source of an error. For the X86-compatible-processor-based target computer 102, the single-step trace command preferably uses, for example, an interrupt 1 (INT1) function by setting an INT1 flag. When the INT1 flag is set, program execution is interrupted after the current instruction even though a break point has not been set at the start of the next instruction. Program execution then passes to an INT1 handler, which returns control to the command prompt of the debugger program 106. Thus, the debugger program 106 preferably “hooks” the INT1 handler, as well as the INT3 handler. The single-step trace command, therefore, causes the debugger program 106 to set the INT1 flag before executing the current instruction. Upon returning through the INT1 handler, the debugger program 106 removes the INT1 flag. Another command may start the single-step trace, as above, but at a specified address. Another command preferably causes the current instruction to be executed without a trace being captured. In this manner, the user can skip capturing a trace of instructions in which the user is not interested. Another command preferably causes the target process 108 to be executed without any interruption until the target process 108 terminates. Another command preferably causes the uninterrupted execution of the target process 108 to start at a specified address or instruction. Another command preferably allows the uninterrupted execution only up to a specified break point, at which the continual-trace begins or control is returned to the command prompt of the debugger program 106. Thus, the user can skip tracing some portions of the target process 108 altogether. Another command preferably causes the contents of the registers 136 to be displayed to the user and/or transferred to the monitoring system 104 for storage. Another command preferably causes data (in a byte, word, dword, etc.) at a default or specified address within the memory subsystem 122 or the cache memory 134 to be displayed to the user and/or transferred to the monitoring system 104 for storage. Another command preferably causes one of the registers 136 to be set to a specified desired value. Another command preferably causes a flag within the processor 120 to be set or unset as desired. Another command preferably causes a specified address (in byte, word, dword, etc.) within the memory subsystem 122 or the cache memory 134 to be set to a specified desired value. Other commands preferably cause data (in byte, word, dword, etc.) to be read from or written to a specified port in the target computer 102. Another command preferably causes bus registers (of one of the bus systems 130 or 132) to be displayed to the user and/or transferred to the monitoring system 104 for storage. Another command preferably causes SPD (serial presence detect) data of a memory module within the memory subsystem 122 to be displayed to the user and/or transferred to the monitoring system 104 for storage. Another command preferably causes an instruction at a default or specified address within the target process 108 to be disassembled, so the user can view other instructions that are not the current instruction. Another command preferably causes an unassembled instruction to be assembled and stored at a default or specified address within the target process 108, so the user can try a different instruction to see if the different instruction cures an error. Another command preferably causes a script of commands to be downloaded from the control data 118 (FIG. 1) in the monitoring system 104 to the target computer 102 and executed. Another command preferably causes the debugger program 106 to terminate. The above set of commands is exemplary only. An actual set of commands may depend on anticipated debugging situations and may include some or all of the above-described commands, one or more different commands not described herein and/or one or more modified versions and/or combinations of the above-described commands. A simplified exemplary procedure 144 for the debugger program 106 to operate on the boot process 138 as the target process 108 in the target computer 102 is shown in FIG. 3. The procedure 144 may be combined with other procedures and have other features whether or not described herein. At some point prior to launching the debugger program 106, the boot process 138 may have copied the contents of the ROM 124 to the memory subsystem 122, so the boot process 138 and any other processes provided in the ROM 124 can operate more quickly from the memory subsystem 122. The copy of the ROM contents is known as a “ROM shadow,” which is usually then write-protected to prevent corruption thereof. However, the debugger program 106 may have to write break points into the boot process 138 in order to capture a trace of the execution of the boot process 138 or in order to interrupt execution of the boot process 138 to examine or modify the contents of the registers 136 or of the memory subsystem 122. Therefore, upon the procedure 144 starting (at 146), the write-protection on the ROM shadow is disabled at 148. The current instruction of the boot process 138, before which the boot process 138 launched the debugger program 106, is disassembled at 150. A trace of the disassembled current instruction is also preferably captured and displayed for the user at 150. The trace capturing may also include transferring the current instruction to the monitoring system 104 for storage. The contents of the registers 136 are optionally displayed and/or transferred to the monitoring system 104 for storage (at 152) as well. From the disassembled current instruction, the offset of the next possible instruction is determined and stored (at 154) in case a break point will be set later, e.g. following a continual trace command entered by the user. The command prompt is displayed (at 156) to the user and the procedure 144 waits for input by the user of a command, such as, but not limited to, the commands described above. Once the user enters one or more commands (at 156), the command is executed at 158. If the command is to end the debugger program 106, then the procedure 144 ends at 160. If the command does not end the debugger program 106, then after executing the command, the procedure 144 returns through A or B to 150 or 156, respectively, depending on whether the current instruction needs to be disassembled, captured and displayed at 150 (followed by 152 and 154, as above) before displaying the command prompt and waiting for the user to input another command at 156. If the command executed at 158 is for a continual trace, then the debugger program 106 jumps to a simplified exemplary procedure 162 for performing a continual trace as shown in FIG. 4. The procedure 162 may be combined with other procedures and have other features whether or not described herein. Upon starting (at 164), a break point is set (at 166) at the start of the next possible instruction, preferably as described above, according to the offset that was determined and stored at 154. Additionally, since (according to a particular embodiment) the setting of the break point replaces the first byte of the next possible instruction, the replaced portion of the next possible instruction is saved (at 166) to a secure memory location. The trace flag is set at 168. Control then jumps to the current instruction of the target process 108 to allow execution of the current instruction at 170. After execution of the current instruction, the break point (set at 166) is encountered at 172 at the start of the next instruction, which is now a new current instruction. According to a particular embodiment, the break point causes a call to the INT3 handler, which returns control to the debugger program 106. Control jumps to 174, at which the portion of the next instruction (now the new current instruction) that had been replaced by setting the break point at 166 is restored. If at 156 the user had set a hard break point after the instruction that was just executed at 170 (as determined at 176), then control returns through B to 150 to disassemble, capture and display the new current instruction (followed by 152 and 154, as above) before displaying the command prompt and waiting for the user to input another command at 156. Otherwise, if there is no hard break point as determined at 176, then the new current instruction is disassembled, captured and displayed (at 178). The contents of the registers 136 are optionally displayed and/or transferred to the monitoring system 104 for storage (at 180) as well. From the disassembled new current instruction, the offset of a new next possible instruction is determined and stored (at 182). If the trace flag is set, as determined (at 184), indicating that the continual trace is being performed, then control returns to 166 to set the next break point as determined from the offset stored at 182. Otherwise, control returns through A to 156 to display the command prompt and wait for the user to input another command. The continual trace continues repeatedly through 166-184 until a hard break point is encountered (at 176) or the target process 108 terminates or crashes. If the command executed at 158 is for a single-step trace command, then the debugger program 106 jumps to a simplified exemplary procedure 186 for performing a single-step trace as shown in FIG. 5. The procedure 186 may be combined with other procedures and have other features whether or not described herein. According to a particular embodiment, upon starting (at 188), the INT1 flag is set at 190. Control then jumps to the target process 108 to execute the current instruction at 192. After the execution of the current instruction, the INT1 flag causes an interrupt, which transfers (at 194) control to the INT1 handler, which transfers control back to the procedure 186. The INT1 flag is then removed (at 196), so control will not keep returning to the INT1 handler. Instead, control returns through B to 150 to disassemble, capture and display the next instruction as the new current instruction (followed by 152 and 154, as above) before displaying the command prompt and waiting for the user to input another command at 156. If the user continues to input the single-step trace command at 156, then the procedure 186 will repeat by tracing and executing one step at a time. If the command executed at 158 is to execute a desired portion of the target process 108 without a trace capture, then control jumps (at 198) to execute the instructions at the desired portion of the target process 108 as illustrated by a simplified exemplary procedure 200 shown in FIG. 6. The execution of the desired portion of the target process 108 may continue until the target process 108 terminates or crashes. However, if the user also set at 156 a hard break point to return control to the debugger program 106 after the desired portion of the target process 108 has been executed, then the hard break point is encountered at 202. The setting (at 156) of the hard break point preferably replaced the first byte of the next instruction following the desired portion of the target process 108 with an INT3 opcode. Therefore, control passes to the INT3 handler, which returns control through C to 174 of procedure 162 in FIG. 4. Therefore, the first byte of the next instruction is restored at 174. At 176, the hard break point is encountered, so the code branches through B to 150 in procedure 144 (FIG. 3) to disassemble, capture and display the next instruction as the new current instruction (followed by 152 and 154, as above) before displaying the command prompt and waiting for the user to input another command at 156. | <SOH> BACKGROUND <EOH>A processor in a computer operates on instructions with no indication of what is happening internally, except for external signals on I/O pins. The contents of registers and cache within the processor may be assumed, if the processor is functioning properly, but are usually unknown, unless a specific request is made to read such information. Since the internal functions of the processor are effectively hidden, if a hardware or software error occurs during execution of a program, it is often difficult or time-consuming to determine whether the cause of the error is in the processor, in some other component of the computer or in the program instructions. Computer program execution tracing is a useful technique for locating hardware and software errors in the performance of a computer by generating, or “capturing,” a “trace” of executed program instructions. The program execution trace may also log certain events as they occur, a so-called event-based profiling technique. The program execution trace is essentially a listing of the executed instructions, called subroutines and accessed resources and sometimes the results thereof. This technique may be used, for example, in a power-on self test (POST) of the computer to discover errors in the performance of the processor, the firmware or the system board. This technique may also be used after POST to discover errors in programs or peripheral devices operating in the computer. Some variations in program execution tracing use logic analyzers, in-target probes (ITPs) or in-circuit emulators (ICEs) to view executed instructions or to generate the program execution traces. Each of these devices has various benefits or uses. However, in addition to the cost of these devices, each also has limitations. The logic analyzer monitors signals within the computer, such as signals on a bus, the I/O pins of a processor or another component in the computer. The logic analyzer can capture the state of the signals at any given moment and can capture a trace of the signals to record changes in the state of the signals over a period of time. The logic analyzer does not, however, control the computer or issue commands to get specific data. Thus, a significant limitation in logic analyzers is that the captured traces are dependent on the external signals of the processor, or other component, being monitored. The internal workings of the processor, such as the state of the registers or the cache, remain hidden. Thus, when the internal cache of the processor is enabled, many instructions cannot be captured. Additionally, significant manual translation and filtering must be done to correlate the captured signal data to actual instructions executed. An ITP or an ICE enables debugging of the computer, the processor or the program during hardware/software development not only by monitoring the I/O pins or bus signals, but also by controlling the processor, bus or other component to which it is connected. Thus, not only does the ITP or ICE intercede between the desired component (e.g. the processor) and circuit board to intercept and/or sense some or all of the signals from the component, but the ITP or ICE can also issue commands to the component. For example, the ITP or ICE can request data from the registers of the processor in addition to displaying a current state of the signals on the I/O pins. The ITP or ICE cannot, however, access the cache, and the less expensive ITPs or ICEs cannot capture a trace of the executed instructions. The ITP or ICE can be used to manually step through each instruction, but this process is very slow. Additionally, some ICEs have some trace capture ability that only runs off a particular bus that the ICE is monitoring, so the ICE captures only the bus activity. Each of these devices (the logic analyzers, ITPs and ICEs) is used within a laboratory setting. In other words, they are used to debug computers, computer components and programs under development by a manufacturer or that have reported errors in the field and have been returned by a consumer. Due to the cost and size of the logic analyzers, ITPs and ICEs, these devices are almost never taken out of the laboratory setting to analyze a computer, component or program in the field. In order to view the contents of the cache and other internal workings of the processor, special “bond-out” versions of integrated circuit chips have been produced. The bond-out chips resemble the standard versions of their integrated circuits, but have special pins, and sometimes complete buses, that make “internal” signals available at special external bond-out interfaces. The bond-out features, however, take up valuable space in, and can affect the operation of, the integrated circuit. Additionally, special devices and programs are needed to decode and give meaning to the signals provided at the special bond-out interfaces. Another technique for monitoring internal functions of the processor involves an “on-chip trace cache” and supporting circuitry within the integrated circuit of the processor. Trace information is captured in the on-chip trace cache during operation of the processor. Afterwards, the captured information can be downloaded and analyzed. This technique, however, takes up valuable space within the integrated circuit. Another technique to analyze the performance of a target computer, but which does not necessarily incorporate additional devices (e.g. the logic analyzers, ITPs and ICEs) or additional on-chip circuitry, is “instrumented source code.” In this technique, executable “tag statements” are inserted into various branches and locations of source code, thereby “instrumenting” the source code. After the source code has been compiled and linked, the tag statements are executed along with the rest of the code. As each tag statement is executed, it performs an operation that can be either detected by an analysis device or recorded within the target computer for later examination. For example, each tag statement may write a value to different addresses so that the contents of the addresses provide an indication of which tag statements were executed and in what order. The general flow of the software is thus indicated by the contents of the addresses. | <SOH> SUMMARY <EOH>According to a particular embodiment of the present invention, a method for debugging a computer system comprises initiating a process in the computer system, the process including instructions; launching a debugger program that is embedded in a ROM of the computer system; executing at least part of the instructions; and the debugger program operating on at least part of the executed instructions. According to another embodiment of the present invention, a computer system comprises a processor; a read-only memory (ROM) connected to the processor; a target process having instructions capable of being executed by the processor; and a debugger program embedded within the ROM and capable of being executed by the processor to operate on at least part of the instructions of the target process. | 20040218 | 20080722 | 20050818 | 67563.0 | 0 | DENG, ANNA CHEN | ROM-EMBEDDED DEBUGGING OF COMPUTER | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,781,039 | ACCEPTED | Self-centering mobile | A mobile comprising a frame, one or more mobile arms, freely rotatable connectors, and display members provide a self-centering and balanced mobile. Freely rotatable connectors can include a spinner assembly and spring clips. The mobile arms and display members can rotate a full and continuous 360 degrees to display items such as photographs on multiple sides of the display member. Display enclosures include balanced construction and thumb cut-outs for ease of access to items displayed in the enclosures. Such self-centering mobiles can be mounted on a variety of surfaces, such as on a table, from a wall, on office systems mounting surfaces, on shelving, and on computer terminals. | 1. A self-centering mobile, comprising: a frame; a plurality of freely rotatable connectors; a horizontally disposed arm having two ends and a balance point between the two ends, the arm suspended from the frame at the balance point with one of the freely rotatable connectors; and a display member suspended from each end of the arm with another one of the freely rotatable connectors and having a weight so that the arm is balanced when suspended from the frame at the arm balance point. 2. The mobile of claim 1, wherein the arm comprises a substantially closed loop at the balance point and at each end of the arm. 3. The mobile of claim 1, wherein the arm comprises a continuous, round rod of substantially rigid material. 4. The mobile of claim 3, wherein the rod of material comprises spring steel. 5. The mobile of claim 3, wherein the rod of material comprises a coating that includes zinc. 6. The mobile of claim 1, wherein the freely rotatable connectors comprise: a spinner assembly adapted to rotate freely for 360 degrees in both clockwise and counter-clockwise directions; and a means for attaching the spinner assembly to the frame and to the arm. 7. The mobile of claim 6, wherein the spinner assembly comprises: a hollow central body having a top and a bottom and an aperture in each of the top and the bottom; and an eye hook disposed in each of the top and the bottom of the central body, each eye hook having a base larger than the apertures rotatably secured inside the central body and a hook portion extending through the aperture. 8. The mobile of claim 6, wherein the means for attaching the spinner assembly to the frame and to the arm comprises a spring clip formed from a round rod of spring steel, the rod formed into a substantially closed “S” shape, each end of the rod bent outwardly from the spring clip to form a receiving channel for receiving the frame and the arm. 9. The mobile of claim 8, wherein the rod of spring steel comprises a coating that includes zinc. 10. The mobile of claim 6, wherein the means for attaching the spinner assembly to the frame and to the arm comprises a dual lock snap fastener comprising: a round rod of spring steel formed into an elongated oval-shaped body, the rod terminating with a first end and an overlapping second end on a first side of the body, wherein the second end is bent approximately perpendicularly to a longitudinal axis of the fastener across the fastener body and releasably around a second side of the body opposite the first side to form a first lock biased by the spring steel, and wherein the first end is bent approximately perpendicularly to the longitudinal axis of the fastener away from the fastener body and releasably around the first side to form a second lock biased by the spring steel. 11. The mobile of claim 1, wherein a plurality of display members is suspended from at least one end of the arm, the balance point located on the arm at a pre-determined point such that a particular combination of display members is balanced. 12. The mobile of claim 11, wherein at least one other arm is suspended from at least one end of the arm with one of the freely rotatable connectors. 13. The mobile of claim 1, wherein the display member comprises a display enclosure comprising: a single, flat sheet of transparent material folded over onto itself to form opposing panels for receiving a substantially flat item for display therebetween; the panels having a top and an aperture near the top and through the panels for connecting the panels to a freely rotatable connector; the panels spaced apart approximately one mm to form a bottom for supporting the display item and for facilitating movement of the display item between the panels; and at least one panel having a cutout near an edge of the panel for facilitating insertion and removal of the display item between the panels. 14. The mobile of claim 13, wherein the sheet of transparent material comprises polyethylene terephthalate glycol. 15. The mobile of claim 13, further comprising a plurality of display enclosures of differing dimensions, a portion of the display enclosures adapted for vertical display and another portion adapted for horizontal display, wherein display enclosures for vertical display and display enclosures for horizontal display having the same dimensions comprise the same weight and are interchangeable. 16. The mobile of claim 1, further comprising a means for stationarily mounting the frame to a surface comprising: an oblong block of material having a top, a bottom, a front, and a back; a bore hole extending at least partially downward through the block toward the bottom for fittingly receiving the frame; a threaded hole through the front of the block approximately perpendicular to and intersecting with the bore hole; a screw insertable into the threaded hole for tightening against the frame to secure the frame in the bore hole; and a means for mounting the block to a surface. 17. The mobile of claim 16, wherein the means for mounting the block to a surface comprises a removable adhesive applied to the back of the block. 18. The mobile of claim 1, further comprising a means for adjustably mounting the frame to a surface comprising: a block of material having two holes extending at least partially through the block in approximately perpendicular directions, one hole comprising a bore hole for fittingly receiving the frame and the other hole comprising a threaded hole intersecting with the bore hole; a first screw insertable into the threaded hole for tightening against the frame to secure the frame in the bore hole; a bracket having a surface-mounting portion and a block-mounting portion perpendicular to the surface-mounting portion; a second screw insertable through another hole in the block perpendicular to the bore hole and through a threaded hole in the block-mounting portion of the bracket for adjustably securing the block and frame in a range of positions within an approximately 90 degree angle around an upright position; and a means for mounting the bracket to a surface. 19. The mobile of claim 18, wherein the means for mounting the bracket to a surface comprises a removable adhesive applied to the back of the bracket. 20. The mobile of claim 1, further comprising a means for adjustably mounting the frame to a surface comprising: a circular block of material having a plurality of holes about the circumference and extending at least partially through the block in approximately perpendicular directions, each pair of holes comprising a bore hole for fittingly receiving the frame and the other hole comprising a threaded hole intersecting with the bore hole; a first screw insertable into the threaded hole for tightening against the frame to secure the frame in the bore hole; a rectangular block of material having a front and a back; a second screw insertable through another threaded hole in the circular block perpendicular to the plurality of paired bore holes and threaded holes and into a threaded hole in the front of the rectangular block for adjustably securing the circular block and frame in a range of positions within a 360 degree span; and a means for mounting the rectangular block to a surface. 21. The mobile of claim 20, wherein the means for mounting the rectangular block to a surface comprises a removable adhesive applied to the back of the rectangular block. 22. A self-centering mobile, comprising: a frame; a plurality of freely rotatable connectors; a horizontally disposed arm comprising a round rod of zinc-coated spring steel and having two ends and a balance point between the two ends, the arm suspended from the frame at the balance point with one of the freely rotatable connectors; and a display member suspended from each end of the arm with another one of the freely rotatable connectors and having a weight so that the arm is balanced when suspended from the frame at the arm balance point, wherein the arm comprises a substantially closed loop at the balance point and at each end of the arm, wherein the freely rotatable connectors comprise a spinner assembly adapted to rotate freely for 360 degrees in both clockwise and counter-clockwise directions and further comprising a hollow central body having an aperture in each of a top and a bottom of the central body and an eye hook disposed in each of the top and the bottom, each eye hook having a base larger than the apertures rotatably secured inside the central body and a hook portion extending through the aperture, and a spring clip for attaching the spinner assembly to the frame and to the arm formed from a round rod of zinc-coated spring steel, the rod formed into a substantially closed “S” shape, each end of the rod bent outwardly from the spring clip to form a receiving channel for receiving the frame and the arm. 23. The mobile of claim 22, wherein a plurality of display members is suspended from at least one end of the arm, the balance point located on the arm at a pre-determined point such that a particular combination of display members is balanced. 24. The mobile of claim 23, wherein at least one other arm is suspended from at least one end of the arm with one of the freely rotatable connectors. 25. The mobile of claim 22, wherein the display member comprises a display enclosure comprising: a single, flat sheet of transparent material folded over onto itself to form opposing panels for receiving a substantially flat item for display therebetween; the panels having a top and an aperture near the top and through the panels for connecting the panels to a freely rotatable connector; the panels spaced apart approximately one mm to form a bottom for supporting the display item and for facilitating movement of the display item between the panels; and at least one panel having a cutout near an edge of the panel for facilitating insertion and removal of the display item between the panels. 26. The mobile of claim 25, wherein the sheet of transparent material comprises polyethylene terephthalate glycol. 27. A method of using a self-centering mobile, comprising: providing a frame, a plurality of freely rotatable connectors, and a horizontally disposed arm comprising a round rod of spring steel and a substantially closed loop at each of two ends and at a balance point between the two ends; suspending the arm from the frame at the balance point with one of the freely rotatable connectors; and suspending from each end of the arm with another one of the freely rotatable connectors a display member having a weight so that the arm is balanced when suspended from the frame at the arm balance point. 28. The method of claim 27, further comprising suspending each of the arm from the frame and the display member from each end of the arm with a spring clip formed from a round rod of spring steel into a substantially closed “S” shape, each end of the rod bent outwardly from the spring clip to form a receiving channel for receiving the frame and the arm, one of the spring clips attached to the top and another spring clip attached to the bottom of a spinner assembly adapted to rotate freely for 360 degrees in both clockwise and counter-clockwise directions. 29. The method of claim 27, further comprising suspending a plurality of display members from at least one end of the arm, the balance point located on the arm at a pre-determined point such that a particular combination of display members is balanced. 30. The method of claim 27, further comprising suspending at least one other arm from at least one end of the arm with one of the freely rotatable connectors. | CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to pending U.S. Provisional Patent Application No. 60/447,559, filed Feb. 14, 2003, which is incorporated herein in its entirety. FIELD OF THE INVENTION The present invention relates to mobiles and in particular to mobiles having self-centering and balanced arms, connectors, and display members. Embodiments of the present invention provide mobile display members and arms that freely rotate a continuous 360 degrees. BACKGROUND OF THE INVENTION A mobile is defined as a type of sculpture consisting of carefully equilibrated parts that move, especially in response to air currents. Mobiles have been made for many years. Engineering principles were applied to the art of mobile-making in the early and mid-twentieth century by the American artist Alexander Calder, who is known as the “Father of the Mobile.” One aim of such a sculpture is to depict movement, that is, kinetic rather than static rhythms. In a conventional mobile, display objects of the same or varying shapes are suspended, for example, from a hook attached to a wire. The display objects are attached to a support structure. A hook is positioned at the fulcrum, or balance point, of the support structure such that support structure and the display objects are balanced. The balance point in a mobile is affected by the weight of the objects being displayed and the distance the objects are located from each other along the fulcrum about which the objects are suspended. Mobiles can include sub-assemblies of one or more display objects that are arranged to form a branching, or “tree” mobile. Display objects can be positioned along the balanced display axis in symmetrical or asymmetrical arrangement. Jump rings, or small circle loops, can be added to the structure from which the objects are suspended to add rotational movement of the objects. However, conventional mobiles that include such connections between support arms and display elements allow displayed items to move clockwise or counterclockwise in less than a full or continuous 360 degree rotation. Display elements of conventional mobiles encounter some degree of torque as the display elements rotate, and often succeed in rotating less than 180 degrees before stopping and turning in the opposite direction. Such mobiles have the disadvantage of preventing full circumferential movement of the displayed items such that a person may not be able to view all sides of the displayed item without manipulating the displayed item or moving to the other side of the mobile to view it. Conventional mobiles do not include arms, connection elements, and display members that cooperate to provide a self-centering and balanced mobile. In particular, conventional mobiles fail to allow display of combinations of vertically-oriented and horizontally-oriented display members that together are self-centering and balanced. Thus, there is a need to provide a mobile that is self-centering and balanced and that provides full and continuous 360 degree rotation of displayed items. SUMMARY OF THE INVENTION The present invention provides a self-centering and balanced mobile having a full and continuous 360 degree rotation of its arms and display members. In an embodiment, a self-centering mobile of the present invention includes a frame, a plurality of freely rotatable connectors, and a horizontally disposed arm having two ends and a balance point between the two ends. The arm is suspended from the frame at the balance point with one of the freely rotatable connectors. A display member is suspended from each end of the arm with another one of the freely rotatable connectors. The display members have a weight so that the arm is balanced when it suspended from the frame at the arm balance point. In one embodiment, the mobile arm comprises a substantially closed loop at the balance point and at each end of the arm. The arm can comprise a continuous, round rod of substantially rigid material. Preferably, the rod of material includes spring steel. In embodiments, the rod of material comprises a coating that includes zinc, which provides a surface with a lower coefficient of resistance that contributes to the self-centering characteristic of the present invention. The freely rotatable connectors can include a spinner assembly adapted to rotate freely for 360 degrees in both clockwise and counter-clockwise directions. One such spinner assembly has a hollow central body with an aperture in both the top and bottom of the body. The central body has an eye hook disposed in both its top and bottom. Each eye hook has a base larger than the apertures and is rotatably secured inside the central body. The hook portion of the eye hook extends through the aperture. The connectors also include a means for attaching the spinner assembly to the frame and to the arm. One embodiment of a means for attaching the spinner assembly to the frame and to the arm comprises a spring clip formed from a round rod of spring steel. The rod is formed into a substantially closed “S” shape. Each end of the rod is bent outwardly from the spring clip to form a receiving channel to help guide the frame and the arm into the rounded portions of the spring clip. Preferably, the spring steel rod of the spring clip has a coating that includes zinc, which provides a smooth contact with the mobile arm and facilitates self-centering of the display member supported by the spring clip on the mobile arm. In embodiments, a mobile of the present invention has a plurality of display members suspended from one or both ends of the arm. In this case, the balance point is located on the arm at a pre-determined point such that a particular combination of display members is balanced. In another combination of the present invention, at least one other arm is suspended from one or both ends of the arm with one of the freely rotatable connectors. In another aspect of the present invention, the display member comprises a display enclosure that includes a single, flat sheet of transparent material folded over onto itself to form opposing panels for receiving a substantially flat item for display between the panels. Preferably, the transparent material includes polyethylene terephthalate glycol (PETG). The panels can have an aperture near the top and through the panels for connecting the panels to a freely rotatable connector. The panels are spaced apart approximately one millimeter (mm) to form a bottom for supporting the display item and for facilitating movement of the display item between the panels. In one embodiment, at least one panel has a cutout near an edge of the panel for facilitating insertion and removal of the display item between the panels. A mobile of the present invention can include a plurality of display enclosures of differing dimensions and that are oriented for vertical display or for horizontal display. Display enclosures having the same dimensions also have the same weight, and can therefore be interchanged for vertical or horizontal display. In another aspect of the present invention, a mobile includes a means for mounting the frame to a surface, either in a stationary or adjustable manner. One such means for mounting a frame in a stationary manner includes an oblong block of material having a bore hole extending at least partially downward through the block toward the bottom for fittingly receiving the frame. A threaded hole extends through the front of the block approximately perpendicularly to and intersecting with the bore hole. A screw can be threaded through the threaded hole for tightening against the frame to secure the frame in the bore hole. Another embodiment of a means for mounting the frame to a surface allows the frame to be mounted in an adjustable manner. For example, a block of material has two holes extending at least partially through the block in approximately perpendicular directions. One hole is a bore hole for fittingly receiving the frame. The other hole is a threaded hole intersecting with the bore hole. A first screw is inserted into the threaded hole for tightening against the frame to secure the frame in the bore hole. A second screw is inserted through another hole in the block perpendicular to the bore hole and through a threaded hole in the block-mounting portion of a bracket. As such, the block and frame can be adjusted and secured in a range of positions within an approximately 90 degree angle around an upright position. Another embodiment for adjustably mounting the frame to a surface includes a circular block of material having a plurality of holes about the circumference that extend at least partially through the block in approximately perpendicular directions. Each pair of holes includes a bore hole for fittingly receiving the frame and a threaded hole intersecting with the bore hole. A first screw can be inserted into the threaded hole for tightening against the frame to secure the frame in the bore hole. A second screw can be inserted through another threaded hole in the circular block perpendicular to the plurality of paired bore holes and threaded holes and into a threaded hole in the front of a rectangular block. Accordingly, the circular block and frame can be adjustably secured in a range of positions within a 360 degree span. In either of these means for mounting the frame to a surface, such as a wall or desk, an adhesive may be applied to the back of the block for attaching the block and frame to the surface. Embodiments of the present invention include methods of using a self-centering mobile. One such embodiment includes the steps of providing a frame, a plurality of freely rotatable connectors, and a horizontally disposed arm comprising a round rod of spring steel and a substantially closed loop at each of two ends and at a balance point between the two ends. The arm can be suspended from the frame at the balance point with one of the freely rotatable connectors. A display member can be suspended from each end of the arm with another one of the freely rotatable connectors. The display members have a weight so that the arm is balanced when suspended from the frame at the arm balance point. In another embodiment of a method, the arm can be suspended from the frame and the display member can be suspended from each end of the arm with a spring clip formed from a round rod of spring steel into a substantially closed “S” shape. Each end of the rod is bent outwardly from the spring clip to form a receiving channel for receiving the frame and the arm. One of the spring clips is attached to the top and another spring clip is attached to the bottom of a spinner assembly. The spinner assembly is adapted to rotate freely for 360 degrees in both clockwise and counter-clockwise directions. A plurality of display members can be suspended from at least one end of the arm, and the balance point is located on the arm at a pre-determined point such that a particular combination of display members is balanced. At least one other arm can be suspended from at least one end of the arm with one of the freely rotatable connectors. Features of a self-centering mobile of the present invention may be accomplished singularly, or in combination, in one or more of the embodiments of the present invention. As will be appreciated by those of ordinary skill in the art, the present invention has wide utility in a number of applications as illustrated by the variety of features and advantages discussed below. A self-centering mobile of the present invention provides numerous advantages over prior mobiles. For example, the present invention advantageously provides a self-centering and balanced mobile. Another advantage is that the present invention provides a mobile having arms and display members that are each freely rotatable through a full and continuous 360 degrees in both clockwise and counterclockwise directions. Another advantage is that the present invention provides a mobile having display members, such as photograph enclosures, in which displayed items are easily accessible with a thumb-sized cutout on one or more edges of the display member. Another advantage is that the present invention provides a self-centering, fully-rotatable mobile adapted for uninterrupted attention-gathering motion useful in point-of-sale advertising, for example, at a check-out counter in a retail store. Another advantage is that the present invention provides a self-centering, fully-rotatable mobile that is easy and inexpensive to manufacture and to use. As will be realized by those of skill in the art, many different embodiments of a self-centering mobile according to the present invention are possible. Additional uses, objects, advantages, and novel features of the invention are set forth in the detailed description that follows and will become more apparent to those skilled in the art upon examination of the following or by practice of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view of a mobile displaying one vertical display enclosure and four horizontal display enclosures in an embodiment of the present invention. FIG. 2 is a view of mobile arms and freely rotatable connectors in an embodiment of the present invention. The mobile arms show angled mobiles arm having rounded and substantially closed loops. FIG. 3 is a view of a spinner assembly connected to a spring slip at the top and at the bottom in an embodiment of the present invention. The lower spring clip is connected to a closed loop of an arm. FIG. 4 is a view of dual lock snap fastener in an embodiment of the present invention. FIG. 5 is a view of a means for stationarily mounting a frame to a surface in an embodiment of the present invention. FIG. 6 is a view of the means for stationarily mounting a frame to a surface shown in FIG. 5, with suspended arms and display elements in an embodiment of the present invention. FIG. 7 is a view of a means for adjustably mounting a frame to a surface in an embodiment of the present invention. FIG. 8 is a view of a means for adjustably mounting a frame to a surface in another embodiment of the present invention. FIG. 9 is a view of the means for adjustably mounting a frame to a surface shown in FIG. 7, with suspended arms and display elements in an embodiment of the present invention. FIG. 10 is a view of the means for adjustably mounting a frame to a surface shown in FIG. 8, with suspended arms and display elements in an embodiment of the present invention. DETAILED DESCRIPTION The present invention provides a self-centering and balanced mobile having a full and continuous 360 degree rotation of its arms and display members. FIGS. 1-10 show various embodiments of mobiles of the present invention. As shown in the embodiment in FIGS. 1 and 2, a self-centering mobile 10 of the present invention includes a frame 20, a plurality of freely rotatable connectors 30, and a horizontally disposed arm 40 having two ends 41 and a balance point 42 between the two ends 41. The arm 40 is suspended from the frame 20 at the balance point 42 with one of the freely rotatable connectors 30. A display member 50 is suspended from each end 41 of the arm 40 with another one of the freely rotatable connectors 30. The display members 50 have a weight so that the arm 40 is balanced when it suspended from the frame 20 at the arm balance point 42. The mobile arm 40 comprises a substantially closed loop 43 at the balance point 42 and at each end 41 of the arm 40. The arm 40 can comprise a continuous, round rod 44 of substantially rigid material. Preferably, the rod 44 of material includes spring steel 45. A mobile superstructure, or frame 20, supports mobile arms 40 and display members 50 from the tops of the arms 50. The frame 20 can be any number of structures that provide a means for suspending a mobile arm 40 and display members 50. For example, a frame 20 can be a support arm 40 mounted to a wall or to other surfaces, such as a work station or computer monitor. Alternatively, a mobile frame 20 can be a table stand. In one embodiment, mobile arms 40 comprise a continuous rod of material in shapes having various angles. For example, a mobile arm 40 can be straight or can have an angle between about 15 degrees and about 175 degrees. In embodiments of the present invention, the middle and end loops 43 of mobile arms 40 are precision-made utilizing programmable “computer numerical control” (“CNC”) wire bending technology. Manufacturing tolerances are held to small ranges to assure consistently made arms 40 and loops 43 in order to help provide the ability to balance and self-center in a suspended mobile 10. The arms 40 can be formed from light stock spring steel 45 having recovery properties, for example music wire. Rods 44 of the present invention can be made from fine tempered, light-gauge music spring steel 45 wire. The round-shaped ends and balance point of the mobile arm 40 have a 360 degree round-to-round surface interaction at points of contact with the generally lighter gauge, for example, 5502-1 and 5502-2 gauge, spring steel connector 30 components, such as a spring clip 70. A round-to-round surface contact allows gravity to maintain the mobile 10 structures on center balance points and thus facilitate balance of asymmetrically arranged display members. In embodiments, the rod 44 of material comprises a coating 46 that includes zinc, which provides a surface with a lower coefficient of resistance that contributes to the self-centering characteristic of the present invention. A zinc coating 46 provides a harder, smoother, and slicker surface than conventional powder-coated surfaces due to an uneven thickness of application, uneven distribution of particulates in the powder, and presence of contaminants in powder. Such a zinc-coated 46 surface facilitates increased efficiency of rotating motion and prevents rusting. Mobile arms 40 can be any color desired, for example, in one embodiment, mobile arms 40 are black. As shown best in FIGS. 2 and 3, the freely rotatable connectors 30 can include a spinner assembly 60 adapted to rotate freely in an uninhibited manner for 360 degrees in both clockwise 61 and counter-clockwise 62 directions. One such spinner assembly 60 has a hollow central body 63 with an aperture 66 in both the top 64 and bottom 65 of the body 63. The central body 63 has an eye hook 67 disposed in both its top 64 and bottom 65. Each eye hook 67 has a base (not shown) larger than the apertures 66 and is rotatably secured inside the central body 63. The hook portion of the eye hook 67 extends through the aperture 66. The connectors 30 also include a means for attaching the spinner assembly 60 to the frame 20 and to the arm 40. One embodiment of a means for attaching the spinner assembly 60 to the frame 20 and to the arm 40 comprises a spring clip 70 formed from a round rod 71 of spring steel 72. The rod 71 is formed into a substantially closed “S” shape 73. Each end 74 of the rod 71 is bent outwardly from the spring clip 70 to form a receiving channel 75 to help guide the frame 20 and the arm 40 into the rounded portions of the “S” shape 73 of the spring clip 70. In embodiments in which the spring clip 70 is made from spring steel 72, after another structure is slid between the outwardly bent end 74 and the body of the spring clip into a rounded portion of the substantially closed loop of the spring clip 70, the spring steel biases the temporary opening between the end 74 and the spring clip 70 body back together to a substantially closed position. As such, the connected structure remains securely positioned on the spring clip 70. Preferably, the spring steel rod 71 of the spring clip 70 has a coating that includes zinc, which provides a smooth contact with the mobile arm 40 and facilitates self-centering of the display member 50 supported by the spring clip 70 on the mobile arm 40. Spring clips 70 can be made in various sizes to fit onto mobile arms 40 and display members 50. In one embodiment, spring clips 70 for attaching to display members 50 are approximately one inch in length. Spring clips 70 for attaching to a mobile arm 40 can be approximately one-half inch in length. A spring clip 70 can have one loop of the “S” shape larger than the other loop. A longer loop facilitates fitting the spring clip 70 over the end of a display member 50, such as a plastic photograph enclosure. This is particularly helpful when the attachment opening in a photograph display enclosure is located away from the edge of the display member 50. In an alternative embodiment, the means for attaching the spinner assembly 60 to the frame 20 and to the arm 40 comprises a dual lock snap fastener 80, as shown in FIG. 4. Such a fastener 80 comprises a round rod of spring steel formed into an elongated oval-shaped body 81. The rod terminates with a first end 82 and an overlapping second end 83 on one side 85 of the body 81. The second end 83 is bent approximately perpendicularly to the longitudinal axis 84 of the fastener 80 across the fastener body 81. The second end 83 is bent around the opposite side 86 of the body 81 in a releasable fashion to form a first latch, or lock, 87 biased closed by the inherent force of the spring steel. The first end 82 is bent approximately perpendicularly to the longitudinal axis 84 of the fastener 80 away from the fastener body 81 and around the first side 82 in a releasable fashion to form a second lock 88 biased by the force of the spring steel. Other structures, such as a mobile arm 40, a spinner assembly 60, and a display member 50, can be inserted inside the snap fastener 80 when the dual locks 87, 88 are open, and the ends 82, 83 are biased back into place. The other structures are thus securely connected to the snap fastener 80. In embodiments, as shown in FIGS. 1, 6, 9, and 10, a mobile 10 of the present invention has a plurality of display members 50 suspended from one or both ends 41 of the arm 40. The balance point 42 is located on the arm 40 at a pre-determined point such that a particular combination of display members 50 is balanced. In another combination of the present invention, at least one other arm 40 is suspended from one or both ends 41 of the arm 40 with one of the freely rotatable connectors 30. Therefore, a self-centering mobile 10 of the present invention allows for display of different sizes and quantities of display members 50, such as photographs, in an asymmetric arrangement that would otherwise require excessive amounts of time, labor, and expense to determine the precise configuration necessary to balance a particular combination of photographs. An asymmetric arrangement is defined as a greater number of display members 50 on one side of an arm balance point 42 than on the other side of the balance point 42. It was discovered that to facilitate maintenance of the balance of an asymmetrical arrangement, combinations of odd numbers of display members 50 are optimal. For example, a combination of three (3) or five (5) display members 50 allow maintenance of an asymmetrical balance, thus allowing a self-centering, display member-supporting mobile 10. Mobiles 10 of the present invention can accommodate a variety of sizes in which photographs are offered commercially, including: 2½″×3″; 3½″×5″; 4″×6″; 5″×7″; and 8″×10″. Embodiments of the present invention are sometimes referred to as “photos in motion” or a “photo mobile.” A display member 50 can be adapted for displaying information or a photograph from multiple sides. Such display members 50 may comprise an enclosure in which the enclosure can include, for example, two display surfaces or sides. Thus, three display members 50 having such enclosures can display six photographs, and five photograph enclosures 50 can display ten photographs. In embodiments of the present invention, each arm 40 and display member 50 has full and continuous 360 degree rotation. In such embodiments, connectors 30 between a mobile frame 20 and horizontally disposed arms 40 and between the arms 40 and display members 50 are fully rotatable such that they have unimpeded movement throughout a full 360 degree circle and can rotate in sequential circles without interruption. As such, the present invention provides mobiles that are “freely-articulated”. That is, the display members 50 can rotate fully clockwise 61 and/or counterclockwise 62 so that one display member 50 can rotate in one direction while another display member 50 on the same mobile 10 can rotate in the opposite direction at the same time. In another aspect of the present invention, the display member 50 comprises a display enclosure 90 that includes a single, flat sheet 91 of transparent material folded over onto itself to form opposing panels 92 for receiving a substantially flat item for display between the panels 92. Mobiles 10 of the present invention are useful for displaying a flat display item such as a photograph or piece of paper with educational, directional, and/or advertising information. Embodiments of the present invention include display members 50 that can rotate a full and continuous 360 degrees. As such, display enclosures 90 having display items such as photographs and other graphic information can be displayed from more than one surface of a display member 50. The item displayed in a display enclosure 90 can be the same on both sides, or a different item can be displayed on each side of the enclosure 90. For example, a self-centering mobile 10 comprising three photograph display members 50 would allow display of six photographs, and a self-centering mobile 10 comprising five photograph display members 50 would allow display of ten photographs. Preferably, the transparent material includes polyethylene terephthalate glycol (PETG). The panels 92 can have an aperture 94 near the top 93 and through the panels 92 for connecting the panels 92 to a freely rotatable connector 30. The panels 92 are spaced apart 95 approximately one millimeter (mm) to form a bottom 96 for supporting the display item and for facilitating movement of the display item between the panels 92. In one embodiment, at least one panel 92 has a cutout 97 near an edge of the panel 92 for facilitating insertion and removal of the display item between the panels 92. Display enclosures 90 can be made by cutting a blank of material with a die and folding the cut blank. A hole is cut in the exact center near the top 93 edge, for example, approximately one-fourth inch from the top edge of the enclosure 90. Cutting the hole through the two layers of material when they are folded together can produce a slight fusion of the material around the edges of the hole, providing a means for holding the top 93 of the enclosure together. Alternatively, display enclosures can be injection molded. Preferably, all exterior edges of the display enclosures 90 are smoothed and the corners are rounded to facilitate manipulation by users without risk of scratching the user's hand on the enclosure 90. Display enclosures 90 of the present invention can be made of various materials that allow viewing a displayed item, such as a photograph or other graphic image, through the material and that are of a weight appropriate for balance on a mobile. Acrylic can be used for display enclosures 90; however, acrylic becomes too heavy for enclosures that 8″×10″ or larger. In addition, acrylic tends to yellow and thus not be as clear as desired for optimal viewing of a displayed item. Polyvinyl chloride (PVC) enclosures can also be used, but PVC tends to have wide color variations from batch to batch due to pigmentation irregularities. In embodiments of the present invention, display enclosures 90 are made from polyethylene teraphthalate glycol (PETG) (available commercially from Piedmont Plastics, Inc.). PETG is preferred because it retains a clear quality. In preferred embodiments, PETG is machined with a protective film on the surfaces of the material to protect against scratching during handling. To provide flat display enclosures that do not tend to warp, or “roll up,” it is preferred to use sheet stock of PETG rather than a roll. As shown in FIGS. 1, 6, 9, and 10, a mobile 10 of the present invention can include a plurality of display enclosures 50 of differing dimensions and that are oriented for vertical display 98 or for horizontal display 99. Display enclosures 90 having the same dimensions also have the same weight, and can therefore be interchanged for vertical 98 or horizontal display 99. That is, vertically-oriented display enclosures 98 and horizontally-oriented display enclosures 99, for example of the 2½″×3½″ size, are each made to have the same weight. As such, each enclosure of the same size, whether vertical or horizontal, can be interchanged on a mobile arm 40. Any combination of vertical 98 and horizontal 99 enclosures of the same size can thus be used for display and maintain a self-centering balance. Accordingly, display enclosures 90 can be displayed in an asymmetric arrangement on a mobile arm 40 while maintaining a self-centering balance. In another aspect of the present invention, a mobile 10 includes a means for mounting the frame 20 to a surface, either in a stationary or adjustable manner. Embodiments of mobiles 10 of the present invention can be mounted on a variety of surfaces. For example, such mobiles 10 can be utilized to display photographs and/or other images on a table, from a wall, on office systems mounting surfaces, on shelving, on computer terminals, and other similar surfaces. In yet another aspect of the present invention, an adjustable arm for mounting a self-centering mobile to a computer monitor or other movable surface is provided. An adjustable mounting arm includes a built-in leveling device that can be adjusted to maintain the mobile arms 40 connectors 30, and display members 50 perpendicular to the floor so that the mobile 10 will be self-centering and balanced. One such means 100 for mounting a frame 20 in a stationary manner includes an oblong block 101 of material having a bore hole 106 extending at least partially downward through the block 101 toward the bottom 103 for fittingly receiving the frame 20. A threaded hole 107 extends through the front 104 of the block 101 approximately perpendicularly to and intersecting with the bore hole 106. A screw 108 can be threaded through the threaded hole 107 for tightening against the frame 20 to secure the frame 20 in the bore hole 106. The screw 108 for securing the frame 20 in the bore hole 106 can be a round-headed screw with a knurled surface for ease of manual turning. The screw 108 can also be slotted for final turning with a screw driver to achieve a tighter, more secure contact with the frame 20. Another embodiment of a means 120 for mounting the frame to a surface allows the frame to be mounted in an adjustable manner. For example, a block 121 of material has two holes extending at least partially through the block 121 in approximately perpendicular directions. One hole is a bore hole 106 for fittingly receiving the frame 20. The other hole is a threaded hole 107 intersecting with the bore hole 106. A first screw 122 is inserted into the threaded hole 107 for tightening against the frame 20 to secure the frame 20 in the bore hole 106. A second screw 126 is inserted through another hole 127 in the block perpendicular to the bore hole 106 and through a threaded hole (not shown) in the block-mounting portion 125 of a bracket 123. As such, the block 121 and frame 20 can be adjusted and secured in a range of positions within an approximately 90 degree angle 128 around an upright position. Another embodiment for adjustably mounting the frame to a surface includes a circular block 130 of material having a plurality of holes about the circumference 131 that extend at least partially through the block 130 in approximately perpendicular directions. Each pair of holes includes a bore hole 106 for fittingly receiving the frame 20 and a threaded hole 107 intersecting with the bore hole 106. A first screw 122 can be inserted into the threaded hole 107 for tightening against the frame 20 to secure the frame 20 in the bore hole 106. A second screw 126 can be inserted through another threaded hole 127 in the circular block 130 perpendicular to the plurality of paired bore holes 106 and threaded holes 107 and into a threaded hole (not shown) in the front 133 of a rectangular block 132. Accordingly, the circular block 130 and frame 20 can be adjustably secured in a range of positions within a 360 degree span. The materials from which the blocks 101, 121, 130 utilized in the mounting systems are made can be a light weight metal, such as aluminum. In either of these means for mounting the frame 20 to a surface, such as a wall or desk, a means 109 for mounting the block 101, 121, 130 to a surface is provided. The means 109 for mounting such a block 101, 121, 130 to a surface can be an adhesive 110 applied to the back of the block 101, 121, 130 for attaching the block 101, 121, 130 and frame 20 to the surface. One such removable adhesive is the “Command” adhesive commercially available from 3M. In alternative embodiments, a mobile 10 of the present invention can be mounted to a music box or other rotational table display for supporting and rotating a mobile 10. Embodiments of the present invention include methods of using a self-centering mobile 10. One such embodiment includes the steps of providing a frame 20, a plurality of freely rotatable connectors 30, and a horizontally disposed arm 40 comprising a round rod 44 of spring steel 45 and a substantially closed loop 43 at each of two ends 41 and at a balance point 42 between the two ends 41. The arm 40 can be suspended from the frame 20 at the balance point 42 with one of the freely rotatable connectors 30. A display member 50 can be suspended from each end 41 of the arm 40 with another one of the freely rotatable connectors 30. The display members 50 have a weight so that the arm 40 is balanced when suspended from the frame 20 at the arm balance point 42. In another embodiment of a method, the arm 40 can be suspended from the frame 20 and the display member 50 can be suspended from each end of the arm 40 with a spring clip 70 formed from a round rod 44 of spring steel into a substantially closed “S” shape 73. Each end of the rod is bent outwardly from the spring clip 70 to form a receiving channel 75 for receiving the frame 20 and the arm 40. One of the spring clips 70 is attached to the top 64 and another spring clip 70 is attached to the bottom 65 of a spinner assembly 60. The spinner assembly 60 is adapted to rotate freely for 360 degrees in both clockwise 61 and counter-clockwise 62 directions. A plurality of display members 50 can be suspended from at least one end 41 of the arm 40, and the balance point 42 is located on the arm 40 at a pre-determined point such that a particular combination of display members 50 is balanced. At least one other arm 40 can be suspended from at least one end 41 of the arm 40 with one of the freely rotatable connectors 30. In another aspect of the present invention, a mobile 10 comprising a plurality of mobile arms 40, connectors 30, and display members 50 is pre-assembled and packaged for retail sale. The pre-assembled and packaged mobile 10 can include sample display items, such as photographs, in display enclosures 90 to demonstrate how the enclosures 90 are to be used by the consumer. As such, embodiments of the present invention having multiple components that interact to provide a self-centering, balanced, fully freely rotatable mobile 10 are provided to consumers for immediate and easy installation and use. Another aspect of the pre-assembled feature of mobiles 10 of the present invention is that the substantially closed loops 43 of the arms 40 and the biasing nature of the spring steel 72 in spring clips 70 prevents the components from separating from each other after being assembled prior to packaging. In such a manner, embodiments comprising advertising information can be shipped ready for retail display. Alternatively, a mobile 10 can be packed in a mailer and then readily displayed by the recipient of the mailer. Although the present invention has been described with reference to particular embodiments, it should be recognized that these embodiments are merely illustrative of the principles of the present invention. Those of ordinary skill in the art will appreciate that a self-centering mobile of the present invention may be constructed and implemented in other ways and embodiments. Accordingly, the description herein should not be read as limiting the present invention, as other embodiments also fall within the scope of the present invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>A mobile is defined as a type of sculpture consisting of carefully equilibrated parts that move, especially in response to air currents. Mobiles have been made for many years. Engineering principles were applied to the art of mobile-making in the early and mid-twentieth century by the American artist Alexander Calder, who is known as the “Father of the Mobile.” One aim of such a sculpture is to depict movement, that is, kinetic rather than static rhythms. In a conventional mobile, display objects of the same or varying shapes are suspended, for example, from a hook attached to a wire. The display objects are attached to a support structure. A hook is positioned at the fulcrum, or balance point, of the support structure such that support structure and the display objects are balanced. The balance point in a mobile is affected by the weight of the objects being displayed and the distance the objects are located from each other along the fulcrum about which the objects are suspended. Mobiles can include sub-assemblies of one or more display objects that are arranged to form a branching, or “tree” mobile. Display objects can be positioned along the balanced display axis in symmetrical or asymmetrical arrangement. Jump rings, or small circle loops, can be added to the structure from which the objects are suspended to add rotational movement of the objects. However, conventional mobiles that include such connections between support arms and display elements allow displayed items to move clockwise or counterclockwise in less than a full or continuous 360 degree rotation. Display elements of conventional mobiles encounter some degree of torque as the display elements rotate, and often succeed in rotating less than 180 degrees before stopping and turning in the opposite direction. Such mobiles have the disadvantage of preventing full circumferential movement of the displayed items such that a person may not be able to view all sides of the displayed item without manipulating the displayed item or moving to the other side of the mobile to view it. Conventional mobiles do not include arms, connection elements, and display members that cooperate to provide a self-centering and balanced mobile. In particular, conventional mobiles fail to allow display of combinations of vertically-oriented and horizontally-oriented display members that together are self-centering and balanced. Thus, there is a need to provide a mobile that is self-centering and balanced and that provides full and continuous 360 degree rotation of displayed items. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides a self-centering and balanced mobile having a full and continuous 360 degree rotation of its arms and display members. In an embodiment, a self-centering mobile of the present invention includes a frame, a plurality of freely rotatable connectors, and a horizontally disposed arm having two ends and a balance point between the two ends. The arm is suspended from the frame at the balance point with one of the freely rotatable connectors. A display member is suspended from each end of the arm with another one of the freely rotatable connectors. The display members have a weight so that the arm is balanced when it suspended from the frame at the arm balance point. In one embodiment, the mobile arm comprises a substantially closed loop at the balance point and at each end of the arm. The arm can comprise a continuous, round rod of substantially rigid material. Preferably, the rod of material includes spring steel. In embodiments, the rod of material comprises a coating that includes zinc, which provides a surface with a lower coefficient of resistance that contributes to the self-centering characteristic of the present invention. The freely rotatable connectors can include a spinner assembly adapted to rotate freely for 360 degrees in both clockwise and counter-clockwise directions. One such spinner assembly has a hollow central body with an aperture in both the top and bottom of the body. The central body has an eye hook disposed in both its top and bottom. Each eye hook has a base larger than the apertures and is rotatably secured inside the central body. The hook portion of the eye hook extends through the aperture. The connectors also include a means for attaching the spinner assembly to the frame and to the arm. One embodiment of a means for attaching the spinner assembly to the frame and to the arm comprises a spring clip formed from a round rod of spring steel. The rod is formed into a substantially closed “S” shape. Each end of the rod is bent outwardly from the spring clip to form a receiving channel to help guide the frame and the arm into the rounded portions of the spring clip. Preferably, the spring steel rod of the spring clip has a coating that includes zinc, which provides a smooth contact with the mobile arm and facilitates self-centering of the display member supported by the spring clip on the mobile arm. In embodiments, a mobile of the present invention has a plurality of display members suspended from one or both ends of the arm. In this case, the balance point is located on the arm at a pre-determined point such that a particular combination of display members is balanced. In another combination of the present invention, at least one other arm is suspended from one or both ends of the arm with one of the freely rotatable connectors. In another aspect of the present invention, the display member comprises a display enclosure that includes a single, flat sheet of transparent material folded over onto itself to form opposing panels for receiving a substantially flat item for display between the panels. Preferably, the transparent material includes polyethylene terephthalate glycol (PETG). The panels can have an aperture near the top and through the panels for connecting the panels to a freely rotatable connector. The panels are spaced apart approximately one millimeter (mm) to form a bottom for supporting the display item and for facilitating movement of the display item between the panels. In one embodiment, at least one panel has a cutout near an edge of the panel for facilitating insertion and removal of the display item between the panels. A mobile of the present invention can include a plurality of display enclosures of differing dimensions and that are oriented for vertical display or for horizontal display. Display enclosures having the same dimensions also have the same weight, and can therefore be interchanged for vertical or horizontal display. In another aspect of the present invention, a mobile includes a means for mounting the frame to a surface, either in a stationary or adjustable manner. One such means for mounting a frame in a stationary manner includes an oblong block of material having a bore hole extending at least partially downward through the block toward the bottom for fittingly receiving the frame. A threaded hole extends through the front of the block approximately perpendicularly to and intersecting with the bore hole. A screw can be threaded through the threaded hole for tightening against the frame to secure the frame in the bore hole. Another embodiment of a means for mounting the frame to a surface allows the frame to be mounted in an adjustable manner. For example, a block of material has two holes extending at least partially through the block in approximately perpendicular directions. One hole is a bore hole for fittingly receiving the frame. The other hole is a threaded hole intersecting with the bore hole. A first screw is inserted into the threaded hole for tightening against the frame to secure the frame in the bore hole. A second screw is inserted through another hole in the block perpendicular to the bore hole and through a threaded hole in the block-mounting portion of a bracket. As such, the block and frame can be adjusted and secured in a range of positions within an approximately 90 degree angle around an upright position. Another embodiment for adjustably mounting the frame to a surface includes a circular block of material having a plurality of holes about the circumference that extend at least partially through the block in approximately perpendicular directions. Each pair of holes includes a bore hole for fittingly receiving the frame and a threaded hole intersecting with the bore hole. A first screw can be inserted into the threaded hole for tightening against the frame to secure the frame in the bore hole. A second screw can be inserted through another threaded hole in the circular block perpendicular to the plurality of paired bore holes and threaded holes and into a threaded hole in the front of a rectangular block. Accordingly, the circular block and frame can be adjustably secured in a range of positions within a 360 degree span. In either of these means for mounting the frame to a surface, such as a wall or desk, an adhesive may be applied to the back of the block for attaching the block and frame to the surface. Embodiments of the present invention include methods of using a self-centering mobile. One such embodiment includes the steps of providing a frame, a plurality of freely rotatable connectors, and a horizontally disposed arm comprising a round rod of spring steel and a substantially closed loop at each of two ends and at a balance point between the two ends. The arm can be suspended from the frame at the balance point with one of the freely rotatable connectors. A display member can be suspended from each end of the arm with another one of the freely rotatable connectors. The display members have a weight so that the arm is balanced when suspended from the frame at the arm balance point. In another embodiment of a method, the arm can be suspended from the frame and the display member can be suspended from each end of the arm with a spring clip formed from a round rod of spring steel into a substantially closed “S” shape. Each end of the rod is bent outwardly from the spring clip to form a receiving channel for receiving the frame and the arm. One of the spring clips is attached to the top and another spring clip is attached to the bottom of a spinner assembly. The spinner assembly is adapted to rotate freely for 360 degrees in both clockwise and counter-clockwise directions. A plurality of display members can be suspended from at least one end of the arm, and the balance point is located on the arm at a pre-determined point such that a particular combination of display members is balanced. At least one other arm can be suspended from at least one end of the arm with one of the freely rotatable connectors. Features of a self-centering mobile of the present invention may be accomplished singularly, or in combination, in one or more of the embodiments of the present invention. As will be appreciated by those of ordinary skill in the art, the present invention has wide utility in a number of applications as illustrated by the variety of features and advantages discussed below. A self-centering mobile of the present invention provides numerous advantages over prior mobiles. For example, the present invention advantageously provides a self-centering and balanced mobile. Another advantage is that the present invention provides a mobile having arms and display members that are each freely rotatable through a full and continuous 360 degrees in both clockwise and counterclockwise directions. Another advantage is that the present invention provides a mobile having display members, such as photograph enclosures, in which displayed items are easily accessible with a thumb-sized cutout on one or more edges of the display member. Another advantage is that the present invention provides a self-centering, fully-rotatable mobile adapted for uninterrupted attention-gathering motion useful in point-of-sale advertising, for example, at a check-out counter in a retail store. Another advantage is that the present invention provides a self-centering, fully-rotatable mobile that is easy and inexpensive to manufacture and to use. As will be realized by those of skill in the art, many different embodiments of a self-centering mobile according to the present invention are possible. Additional uses, objects, advantages, and novel features of the invention are set forth in the detailed description that follows and will become more apparent to those skilled in the art upon examination of the following or by practice of the invention. | 20040217 | 20090428 | 20050818 | 91062.0 | 0 | DAVIS, CASSANDRA HOPE | SELF-CENTERING MOBILE | SMALL | 0 | ACCEPTED | 2,004 |
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10,781,044 | ACCEPTED | Mechanical interaction with a phone using a cradle | This invention describes a special cradle having mechanical switches to facilitate interactions between a communication device, such as a mobile device or a mobile phone, and a user of said devices, wherein said communication device is mounted on said cradle. When the user pushes the communication device in different directions, said device moves and tilts within said stable cradle. The movements are registered through the mechanical switches within the cradle. The states of the switches are communicated to the device (phone) through a mechanical connector or a wireless communication channel as a corresponding command, and the user interface reacts accordingly. | 1. A method for transferring at least one predetermined command by a user to a communication device using a cradle, comprising the steps of: pushing said communication device in a predetermined direction to impose a pushing action on, or to make a physical contact of said communication device, with at least one switch of the cradle to reverse a state of said at least one switch, wherein said communication device is mounted on said cradle and optionally there is no said physical contact before said pushing; and communicating said reversal of the state of said at least one switch to said communication device, wherein said reversal is interpreted by the communication device as said at least one predetermined command by the user. 2. The method of claim 1, wherein the step of pushing said communication device is implemented by applying a mechanical force to said communication device by the user, and wherein said pushing action or said physical contact is characterized in that said mechanical force creates a push force of said communication device on the at least one switch. 3. The method of claim 2, wherein said at least one switch is a vertical switch located on a bottom of the cradle in such a way that said vertical switch reverses its state when the push force is in a vertical direction, wherein said communication device is optionally supported by said vertical switch when the push force is not applied. 4. The method of claim 3, wherein there is the at least one switch in addition to the vertical switch contained in the cradle and said vertical switch is used as a pivotal point for guiding the communication device towards said at least one switch. 5. The method of claim 4, wherein said pivotal point is used as the vertical switch with the higher push force required for its reversal than for any other of the at least one switch, or said pivotal point is only used for said guiding and not as a reversal switch. 6. The method of claim 3, wherein, in addition to said vertical switch, said at least one switch is located on the bottom of the cradle in a plane parallel to a front plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a front tilting motion of said communication device in the plane parallel to the front plane of said communication device optionally using said vertical switch as a pivotal point for facilitating said front tilting motion. 7. The method of claim 3, wherein, in addition to said vertical switch, said at least one switch is located on the bottom of the cradle in a plane parallel to a side plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a side tilting motion of said communication device in the plane parallel to the side plane of said communication device optionally using said vertical switch as a pivotal point for facilitating the side tilting motion. 8. The method of claim 3, wherein, in addition to said vertical switch, said at least one switch is located on a side of the cradle, said side being perpendicular to said bottom, in a plane parallel to a front plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a front tilting motion of said communication device in the plane parallel to the front plane of said communication device optionally using said vertical switch as a pivotal point for facilitating said front tilting motion. 9. The method of claim 3, wherein, in addition to said vertical switch, said at least one switch is located on a side of the cradle, said side being perpendicular to said bottom, in a plane parallel to a side plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a side tilting motion of said communication device in the plane parallel to the side plane of said communication device optionally using said vertical switch as a pivotal point for facilitating the side tilting motion. 10. The method of claim 1, wherein the step of communicating said reversal comprises the steps of: sending at least one reversal signal by the at least one switch to a communication block; and sending at least one command signal by the communication block to the communication device, wherein said at least one command signal completes said transferring of said at least one predetermined command signal. 11. The method of claim 9, wherein the at least one command signal is sent via a wire connection or via a wireless connection by the communication block to the communication device. 12. The method of claim 1, wherein said communication device is a mobile device or a mobile phone. 13. The method of claim 1, wherein the step of pushing said communication device in a predetermined direction is performed by the user. 14. The method of claim 1, wherein said cradle is attached to a car dashboard or to a handle bar of a bicycle. 15. A cradle for transferring at least one predetermined command to a communication device by a user, comprising: at least one switch, responsive to a pushing action of, or to making a physical contact with, said communication device facilitated by pushing said communication device in a predetermined direction by a user, for providing a reversal signal indicative of changing a state of said at least one switch in response to said push or the physical contact, wherein said communication device is mounted on said cradle and optionally there is no said physical contact before said pushing is applied; and a communication block, responsive to said reversal signal, for providing a command signal to said communication device, wherein said at least one command signal completes said transferring of said at least one predetermined command signal to the communication device by the user. 16. The cradle of claim 15, wherein the command signal is sent via a wire connection or via a wireless connection by the communication block to the communication device. 17. The cradle of claim 15, wherein said pushing of said communication device is implemented by applying a mechanical force to said communication device by the user, and wherein said pushing action or a physical contact is characterized in that said mechanical force creates a push force of said communication device on the at least one switch. 18. The cradle of claim 17, wherein said at least one switch is a vertical switch located on a bottom of the cradle in such a way that said at least one switch reverses its state when the push force is in a vertical direction, wherein said communication device is optionally supported by said vertical switch when the push force is not applied. 19. The cradle of claim 18, wherein there is the at least one switch in addition to the vertical switch contained in the cradle and said vertical switch is used as a pivotal point for guiding the communication device towards said at least one switch. 20. The cradle of claim 19, wherein said pivotal point is used as the vertical switch with the higher push force required for its reversal than for any other of the at least one switch, or said pivotal point is only used for said guiding and not as a reversal switch. 21. The cradle of claim 18, wherein, in addition to said vertical switch, said at least one switch is located on the bottom of the cradle in a plane parallel to a front plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a front tilting motion of said communication device in the plane parallel to the front plane of said communication device optionally using said vertical switch as a pivotal point for facilitating said front tilting motion. 22. The cradle of claim 18, wherein, in addition to said vertical switch, said at least one switch is located on the bottom of the cradle in a plane parallel to a side plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a side tilting motion of said communication device in the plane parallel to the side plane of said communication device optionally using said vertical switch as a pivotal point for facilitating the side tilting motion. 23. The cradle of claim 18, wherein, in addition to said vertical switch, said at least one switch is located on a side of the cradle, said side being perpendicular to said bottom, in a plane parallel to a front plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a front tilting motion of said communication device in the plane parallel to the front plane of said communication device optionally using said vertical switch as a pivotal point for facilitating said front tilting motion. 24. The cradle of claim 18, wherein, in addition to said vertical switch, said at least one switch is located on a side of the cradle, said side being perpendicular to said bottom, in a plane parallel to a side plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a side tilting motion of said communication device in the plane parallel to the side plane of said communication device optionally using said vertical switch as a pivotal point for facilitating the side tilting motion. 25. The cradle of claim 15, wherein said communication device mounted on said cradle is a mobile device or a mobile phone. 26. The cradle of claim 15, wherein said cradle is attached to a car dashboard or to a handle bar of a bicycle. | FIELD OF THE INVENTION This invention generally relates to communication devices such as mobile phones and more specifically to utilizing a specialized cradle having mechanical switches for facilitating interactions between said devices and a user of said devices. BACKGROUND OF THE INVENTION 1. Problem Formulation When driving a bike or a car, resources used to interact with a mobile device (phone) are limited. Operator's eyes are occupied most of the time for monitoring the traffic and hands are used for other tasks such as operating vehicle steering. However, current phone interaction is highly dependent on a visual feedback from a display, and precise motor operations. More simple and robust techniques are needed for the most important tasks, such as, e.g., incoming call handling. 2. Prior Art Solutions Speech commands have been used in vehicles. However, when driving (especially a bike), surrounding noises reduce a reliability of an automatic speech recognition. Using the speech recognition alone is also difficult; the reliability of the recognition is much higher when an activation button is used to explicitly start the recognition. This limits the usefulness of the speech recognition, since instead of pressing a “start recognition” key, the user can as easily press an “answer incoming call” key. Some cars also have dedicated keys installed for simple phone commands (e.g., Send/End keys). This solution is pretty good in terms of usability and safety, but requires complex installation. Acceleration sensors can be used to detect simple tap or tilt gestures. For example, the user can simply tap the phone front to answer a call. However, the acceleration-sensing is sensitive to external disturbances, especially when driving on a bumpy road, or when using a non-spring-supported vehicle (e.g. most bikes do not have springs). SUMMARY OF THE INVENTION The object of the present invention is to provide a methodology for using a specialized cradle having mechanical switches for facilitating interactions between a communication device (such as a mobile device or a mobile phone) and a user of said devices, wherein said communication device is mounted on said cradle. According to a first aspect of the invention, a method for transferring at least one predetermined command by a user to a communication device using a cradle, comprising the steps of: pushing said communication device in a predetermined direction to impose a pushing action on, or to make a physical contact of said communication device, with at least one switch of the cradle to reverse a state of said at least one switch, wherein said communication device is mounted on said cradle and optionally there is no said physical contact before said pushing; and communicating said reversal of the state of said at least one switch to said communication device, wherein said reversal is interpreted by the communication device as said at least one predetermined command by the user. According further to the first aspect of the invention, the step of pushing said communication device may be implemented by applying a mechanical force to said communication device by the user, and wherein said pushing action or said physical contact is characterized in that said mechanical force creates a push force of said communication device on the at least one switch. Further, said at least one switch may be a vertical switch located on a bottom of the cradle in such a way that said vertical switch reverses its state when the push force is in a vertical direction, wherein said communication device may be optionally supported by said vertical switch when the push force is not applied. Still further, there may be the at least one switch in addition to the vertical switch contained in the cradle and said vertical switch may be used as a pivotal point for guiding the communication device towards said at least one switch. Yet still further, said pivotal point may be used as the vertical switch with the higher push force required for its reversal than for any other of the at least one switch, or said pivotal point may be only used for said guiding and not as a reversal switch. Further according to the first aspect of the invention, in addition to said vertical switch, said at least one switch may be located on the bottom of the cradle in a plane parallel to a front plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a front tilting motion of said communication device in the plane parallel to the front plane of said communication device optionally using said vertical switch as a pivotal point for facilitating said front tilting motion. Further, in addition to said vertical switch, said at least one switch may be located on the bottom of the cradle in a plane parallel to a side plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a side tilting motion of said communication device in the plane parallel to the side plane of said communication device optionally using said vertical switch as a pivotal point for facilitating the side tilting motion. Still further, in addition to said vertical switch, said at least one switch may be located on a side of the cradle, said side being perpendicular to said bottom, in a plane parallel to a front plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a front tilting motion of said communication device in the plane parallel to the front plane of said communication device optionally using said vertical switch as a pivotal point for facilitating said front tilting motion. Yet still further, in addition to said vertical switch, said at least one switch may be located on a side of the cradle, said side being perpendicular to said bottom, in a plane parallel to a side plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a side tilting motion of said communication device in the plane parallel to the side plane of said communication device optionally using said vertical switch as a pivotal point for facilitating the side tilting motion. Still further according to the first aspect of the invention, the step of communicating said reversal may comprise the steps of: sending at least one reversal signal by the at least one switch to a communication block; and sending at least one command signal by the communication block to the communication device, wherein said at least one command signal completes said transferring of said at least one predetermined command signal. Still further, the command signal may be sent via a wire connection or via a wireless connection by the communication block to the communication device. According further to the first aspect of the invention, the communication device may be a mobile device or a mobile phone. According still further to the first aspect of the invention, the step of pushing said communication device in a predetermined direction is performed by the user. According further still to the first aspect of the invention, the cradle may be attached to a car dashboard or to a handle bar of a bicycle. According to a second aspect of the invention, a cradle for transferring at least one predetermined command to a communication device by a user, comprising: at least one switch, responsive to a pushing action of, or to making a physical contact with, said communication device facilitated by pushing said communication device in a predetermined direction by a user, for providing a reversal signal indicative of changing a state of said at least one switch in response to said push or the physical contact, wherein said communication device is mounted on said cradle and optionally there is no said physical contact before said pushing is applied; and a communication block, responsive to said reversal signal, for providing a command signal to said communication device, wherein said at least one command signal completes said transferring of said at least one predetermined command signal to the communication device by the user. According further to the second aspect of the invention, the command signal may be sent via a wire connection or via a wireless connection by the communication block to the communication device. Further according to the second aspect of the invention, the pushing of said communication device may be implemented by applying a mechanical force to said communication device by the user, and wherein said pushing action or a physical contact is characterized in that said mechanical force creates a push force of said communication device on the at least one switch. Further, said at least one switch may be a vertical switch located on a bottom of the cradle in such a way that said at least one switch reverses its state when the push force is in a vertical direction, wherein said communication device is optionally supported by said vertical switch when the push force is not applied. Still further, there may be the at least one switch in addition to the vertical switch contained in the cradle and said vertical switch is used as a pivotal point for guiding the communication device towards said at least one switch. Still further, said pivotal point may be used as the vertical switch with the higher push force required for its reversal than for any other of the at least one switch, or said pivotal point may be only used for said guiding and not as a reversal switch. Yet still further according to the second aspect of the invention, in addition to said vertical switch, said at least one switch may be located on the bottom of the cradle in a plane parallel to a front plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a front tilting motion of said communication device in the plane parallel to the front plane of said communication device optionally using said vertical switch as a pivotal point for facilitating said front tilting motion. Further, in addition to said vertical switch, said at least one switch may be located on the bottom of the cradle in a plane parallel to a side plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a side tilting motion of said communication device in the plane parallel to the side plane of said communication device optionally using said vertical switch as a pivotal point for facilitating the side tilting motion. Still further, in addition to said vertical switch, said at least one switch may be located on a side of the cradle, said side being perpendicular to said bottom, in a plane parallel to a front plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a front tilting motion of said communication device in the plane parallel to the front plane of said communication device optionally using said vertical switch as a pivotal point for facilitating said front tilting motion. Yet still further, in addition to said vertical switch, said at least one switch may be located on a side of the cradle, said side being perpendicular to said bottom, in a plane parallel to a side plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a side tilting motion of said communication device in the plane parallel to the side plane of said communication device optionally using said vertical switch as a pivotal point for facilitating the side tilting motion. Still further according to the second aspect of the invention, said communication device mounted on said cradle may be a mobile device or a mobile phone. According further to the second aspect of the invention, the cradle may be attached to a car dashboard or to a handle bar of a bicycle. The present invention describes an alternative to an acceleration-sensing method that is more robust and more suitable for all driving conditions with a bike or a car. Since the tilting of the phone is sensed by mechanical switches, the solution is much less prone to external accelerations. The mechanical switches also give a tactile feedback to the user, which is helpful since other feedback types may be absent (especially a visual feedback is limited by a visual attention to a surrounding traffic). BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the nature and objects of the present invention, reference is made to the following detailed description taken in conjunction with the following drawings, in which: FIGS. 1a and 1b show front and side views, respectively, representing an example of mounting a communication device in a cradle with a vertical switch and using a vertical motion of the communication device to activate the switch, according to the present invention. FIGS. 2a and 2b show front and side views, respectively, representing an example of mounting a communication device in a cradle with a vertical switch and additional switches located on a bottom of the cradle and using a vertical motion and/or tilting motion of the communication device to activate one of the switches, according to the present invention. FIGS. 3a and 3b show front and side views, respectively, representing an example of mounting a communication device in a cradle with a vertical switch and additional switches located on a side of the cradle (said side is perpendicular to a bottom of the cradle) and using a vertical motion and/or tilting motion of the communication device to activate one of the switches, according to the present invention. FIG. 4 is a block diagram of transferring signals and mechanical forces between a cradle, a user and a communication device. BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides a novel methodology for using a special cradle having mechanical switches to facilitate interactions between a communication device, such as a mobile device or a mobile phone, and a user of said devices, wherein said communication device is mounted on said cradle. The cradle can be attached for example to a car dashboard (like in current car kits) and/or to a handle bar of a bicycle. When the user pushes the communication device such as the mobile phone in different directions, the phone moves and tilts within said stabile cradle. The movements are registered through the mechanical switches within the cradle. The states of the switches are communicated to the phone through a mechanical connector (e.g., pop port) or a wireless communication channel (such as bluetooth) as a corresponding command, and the user interface reacts accordingly. At least 5 tilt/push operations are feasible, as described in different examples of FIGS. 1a and 1b, 2a and 2b, 3a and 3b. For the purpose of the present invention, the term “pushing” is used to accommodate all kinds of movement of said communication device including pulling, actuating, tilting, etc. FIGS. 1a and 1b show front and side views, respectively, representing an example among others of mounting a communication device (e.g., a mobile phone) 10 in a cradle 12 with a vertical switch 14 located on a bottom of the cradle 12, and using a vertical motion 16 of the communication device 10, imposed on said communication device 10 by a user 11, to activate the switch 14 by a physical contact with said device 10 (optionally) or by pushing said switch 14 by said device 10 enough to reverse a state of said switch 14, according to the present invention. The cradle 12 can contain mechanical structures (not shown in detail in FIGS. 1a and 1b) for guiding the device (phone) 10 movements towards the switch 14. The physical contact of the device 10 with the switch 14 is optional before said pushing is applied. The reversal of the state of the switch 14 is communicated to said communication device 10 wherein said reversal is interpreted by the communication device 10 as a predetermined command given by the user 11, as described below in detail in regard to FIG. 4. FIGS. 1 and 1b demonstrate the most simple implementation of the present invention with just one switch 14. More complex scenarios with multiple switches are shown in FIGS. 2a and 2b, 3a and 3b. FIGS. 2a and 2b show front and side views, respectively, representing one example among others of mounting the communication device 10 in a cradle 12a with the vertical switch 14 and additional switches 18a and 18b, respectively, located on a bottom of the cradle 12a and using the vertical motion 16 or tilting motions 20 or 22 of the communication device 10, imposed on said communication device 10 by the user 11, to activate at least one of the switches 14, 18a or 18b by a physical contact with said device 10 (optionally) or by pushing said switch 14, 18a or 18b (using the device 10) deep enough to reverse a state of said switch 14, 18a or 18b, according to the present invention. The cradle 12 can contain mechanical structures (not shown in detail in FIGS. 2a and 2b) for guiding the device (phone) 10 movements towards the switch 14, 18a or 18b. As in FIG. 1, the physical contact of the device 10 with any of the switches 14, 18a or 18b before said pushing is applied by the user 11 is optional. FIG. 2a, in addition to said vertical switch 14, shows two switches 18a located on the bottom of the cradle 12a (on both sides of the switch 14) in a plane parallel to a front plane of said communication device 10 and containing said vertical switch 14 and wherein said switches 18a reverse their state when pushed by said communication device 10, optionally using said vertical switch 14 as a pivotal point 14a for facilitating said front tilting motion 20 of the device 10. FIG. 2b, in addition to said vertical switch 14, shows two switches 18b located on the bottom of the cradle 12a (on both sides of the switch 14) in a plane parallel to a side plane (or perpendicular to the front plane) of said communication device 10 and containing said vertical switch 14 and wherein said switches 18b reverse their state when pushed by said communication device 10, optionally using said vertical switch 14 as a pivotal point 14a for facilitating said side tilting motion 22 of the device 10. As in FIG. 1, the reversal of the state of the switches 14, 18a or 18b is communicated to said communication device 10 wherein said reversal is interpreted by the communication device 10 as the predetermined command given by the user 11, as described below in detail in regard to FIG. 4. FIGS. 3a and 3b show front and side views, respectively, representing an example among others of mounting the communication device 10 in a cradle 12b with the vertical switch 14 and additional switches 18c and 18d, respectively, located on a side of the cradle 12a and using the vertical motion 16 or tilting motions 20 or 22 of the communication device 10, imposed on said communication device 10 by the user 11, to activate at least one of the switches 14, 18c or 18b by a physical contact with said device 10 (optionally) or by pushing said switch 14, 18c or 18d (using the device 10) deep enough to reverse a state of said switch 14, 18c or 18d, according to the present invention. The cradle 12 can contain mechanical structures (not shown in detail in FIGS. 3a and 3b) for guiding the device (phone) 10 movements towards the switch 14, 18c or 18d. As in FIG. 1, the physical contact of the device 10 with any of the switches 14, 18c or 18d before said pushing is applied by the user 11 is optional. FIG. 3a, in addition to said vertical switch 14, shows two switches 18c located on a side of the cradle 12b (said side is perpendicular to the bottom of the cradle 12b) in a plane parallel to the front plane of said communication device 10 and containing said vertical switch 14 and wherein said switches 18c reverse their state when pushed by said communication device 10, optionally using said vertical switch 14 as a pivotal point 14a for facilitating said front tilting motion 20. FIG. 3b, in addition to said vertical switch 14, shows one switch 18d (it can be more than one, according to the present invention) located on one side of the cradle 12b in a plane parallel to the side plane (or perpendicular to the front plane) of said communication device 10 and containing said vertical switch 14 and wherein said switch 18d reverses its state when pushed by said communication device 10, optionally using said vertical switch 14 as a pivotal point 14a for facilitating said side tilting motion 22. As in FIG. 1, the reversal of the state of the switches 14, 18c or 18d is communicated to said communication device 10 wherein said reversal is interpreted by the communication device 10 as the predetermined command given by the user 11, as described below in detail in regard to FIG. 4. Finally, FIG. 4 shows one example among others of a block diagram for transferring signals and mechanical forces between the cradle 12, 12a or 12b, the user 11 and the communication device (e.g. the mobile device or the mobile phone) 10. This block diagram applies to all scenarios shown in FIGS. 1a and 1b, 2a and 2b, 3a and 3b. A mechanical force 36 is applied to the communication device (the mobile device or the mobile phone) 10 by the user 11 as an indication of a predetermined command to be transferred to said communication device 10. This command, for example, can be to “pick up” the phone and start conversation in response to a phone ring. The mechanical force 36 creates a push force 38 imposing a pushing action of said communication device 10 on one of the switches 14, 18a, 18b, 18c or 18d (or making a physical contact between the communication device 10 and one of said switches) to reverse the state of one of the switches 14, 18a, 18b, 18c or 18d. Said reversal of the one of the switches 14, 18a, 18b, 18c or 18d is communicated to said communication device 10 by sending a reversal signal 32 by one of the switches 14, 18a, 18b, 18e or 18d to a communication block 30 of the cradle 12, 12a or 12b. The communication block 30 sends a command signal 34 to the communication device 10 and completes said transferring of said predetermined command from the user 11 to the communication device 10. The command signal 34 can be sent via a wire connection using a mechanical connector (e.g. pop port) or via a wireless connection using a wireless communication channel (such as bluetooth) by the communication block 30 to the communication device 10. There are many possible variations of the present invention. For example different types of switches can be used. One possibility is to use a switch responsive to a physical contact or a touch. Another variation relates to the pivotal point 14a which can be used as the vertical switch 14, for example, with higher pushing force required for its reversal than for other switches 18a 18b, 18c or 18d, or said pivotal point 14a can be only used for said guiding the device 10 and not as a reversal switch. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Problem Formulation When driving a bike or a car, resources used to interact with a mobile device (phone) are limited. Operator's eyes are occupied most of the time for monitoring the traffic and hands are used for other tasks such as operating vehicle steering. However, current phone interaction is highly dependent on a visual feedback from a display, and precise motor operations. More simple and robust techniques are needed for the most important tasks, such as, e.g., incoming call handling. 2. Prior Art Solutions Speech commands have been used in vehicles. However, when driving (especially a bike), surrounding noises reduce a reliability of an automatic speech recognition. Using the speech recognition alone is also difficult; the reliability of the recognition is much higher when an activation button is used to explicitly start the recognition. This limits the usefulness of the speech recognition, since instead of pressing a “start recognition” key, the user can as easily press an “answer incoming call” key. Some cars also have dedicated keys installed for simple phone commands (e.g., Send/End keys). This solution is pretty good in terms of usability and safety, but requires complex installation. Acceleration sensors can be used to detect simple tap or tilt gestures. For example, the user can simply tap the phone front to answer a call. However, the acceleration-sensing is sensitive to external disturbances, especially when driving on a bumpy road, or when using a non-spring-supported vehicle (e.g. most bikes do not have springs). | <SOH> SUMMARY OF THE INVENTION <EOH>The object of the present invention is to provide a methodology for using a specialized cradle having mechanical switches for facilitating interactions between a communication device (such as a mobile device or a mobile phone) and a user of said devices, wherein said communication device is mounted on said cradle. According to a first aspect of the invention, a method for transferring at least one predetermined command by a user to a communication device using a cradle, comprising the steps of: pushing said communication device in a predetermined direction to impose a pushing action on, or to make a physical contact of said communication device, with at least one switch of the cradle to reverse a state of said at least one switch, wherein said communication device is mounted on said cradle and optionally there is no said physical contact before said pushing; and communicating said reversal of the state of said at least one switch to said communication device, wherein said reversal is interpreted by the communication device as said at least one predetermined command by the user. According further to the first aspect of the invention, the step of pushing said communication device may be implemented by applying a mechanical force to said communication device by the user, and wherein said pushing action or said physical contact is characterized in that said mechanical force creates a push force of said communication device on the at least one switch. Further, said at least one switch may be a vertical switch located on a bottom of the cradle in such a way that said vertical switch reverses its state when the push force is in a vertical direction, wherein said communication device may be optionally supported by said vertical switch when the push force is not applied. Still further, there may be the at least one switch in addition to the vertical switch contained in the cradle and said vertical switch may be used as a pivotal point for guiding the communication device towards said at least one switch. Yet still further, said pivotal point may be used as the vertical switch with the higher push force required for its reversal than for any other of the at least one switch, or said pivotal point may be only used for said guiding and not as a reversal switch. Further according to the first aspect of the invention, in addition to said vertical switch, said at least one switch may be located on the bottom of the cradle in a plane parallel to a front plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a front tilting motion of said communication device in the plane parallel to the front plane of said communication device optionally using said vertical switch as a pivotal point for facilitating said front tilting motion. Further, in addition to said vertical switch, said at least one switch may be located on the bottom of the cradle in a plane parallel to a side plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a side tilting motion of said communication device in the plane parallel to the side plane of said communication device optionally using said vertical switch as a pivotal point for facilitating the side tilting motion. Still further, in addition to said vertical switch, said at least one switch may be located on a side of the cradle, said side being perpendicular to said bottom, in a plane parallel to a front plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a front tilting motion of said communication device in the plane parallel to the front plane of said communication device optionally using said vertical switch as a pivotal point for facilitating said front tilting motion. Yet still further, in addition to said vertical switch, said at least one switch may be located on a side of the cradle, said side being perpendicular to said bottom, in a plane parallel to a side plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a side tilting motion of said communication device in the plane parallel to the side plane of said communication device optionally using said vertical switch as a pivotal point for facilitating the side tilting motion. Still further according to the first aspect of the invention, the step of communicating said reversal may comprise the steps of: sending at least one reversal signal by the at least one switch to a communication block; and sending at least one command signal by the communication block to the communication device, wherein said at least one command signal completes said transferring of said at least one predetermined command signal. Still further, the command signal may be sent via a wire connection or via a wireless connection by the communication block to the communication device. According further to the first aspect of the invention, the communication device may be a mobile device or a mobile phone. According still further to the first aspect of the invention, the step of pushing said communication device in a predetermined direction is performed by the user. According further still to the first aspect of the invention, the cradle may be attached to a car dashboard or to a handle bar of a bicycle. According to a second aspect of the invention, a cradle for transferring at least one predetermined command to a communication device by a user, comprising: at least one switch, responsive to a pushing action of, or to making a physical contact with, said communication device facilitated by pushing said communication device in a predetermined direction by a user, for providing a reversal signal indicative of changing a state of said at least one switch in response to said push or the physical contact, wherein said communication device is mounted on said cradle and optionally there is no said physical contact before said pushing is applied; and a communication block, responsive to said reversal signal, for providing a command signal to said communication device, wherein said at least one command signal completes said transferring of said at least one predetermined command signal to the communication device by the user. According further to the second aspect of the invention, the command signal may be sent via a wire connection or via a wireless connection by the communication block to the communication device. Further according to the second aspect of the invention, the pushing of said communication device may be implemented by applying a mechanical force to said communication device by the user, and wherein said pushing action or a physical contact is characterized in that said mechanical force creates a push force of said communication device on the at least one switch. Further, said at least one switch may be a vertical switch located on a bottom of the cradle in such a way that said at least one switch reverses its state when the push force is in a vertical direction, wherein said communication device is optionally supported by said vertical switch when the push force is not applied. Still further, there may be the at least one switch in addition to the vertical switch contained in the cradle and said vertical switch is used as a pivotal point for guiding the communication device towards said at least one switch. Still further, said pivotal point may be used as the vertical switch with the higher push force required for its reversal than for any other of the at least one switch, or said pivotal point may be only used for said guiding and not as a reversal switch. Yet still further according to the second aspect of the invention, in addition to said vertical switch, said at least one switch may be located on the bottom of the cradle in a plane parallel to a front plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a front tilting motion of said communication device in the plane parallel to the front plane of said communication device optionally using said vertical switch as a pivotal point for facilitating said front tilting motion. Further, in addition to said vertical switch, said at least one switch may be located on the bottom of the cradle in a plane parallel to a side plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a side tilting motion of said communication device in the plane parallel to the side plane of said communication device optionally using said vertical switch as a pivotal point for facilitating the side tilting motion. Still further, in addition to said vertical switch, said at least one switch may be located on a side of the cradle, said side being perpendicular to said bottom, in a plane parallel to a front plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a front tilting motion of said communication device in the plane parallel to the front plane of said communication device optionally using said vertical switch as a pivotal point for facilitating said front tilting motion. Yet still further, in addition to said vertical switch, said at least one switch may be located on a side of the cradle, said side being perpendicular to said bottom, in a plane parallel to a side plane of said communication device and containing said vertical switch and wherein said at least one switch reverses its state when the push force is created by a side tilting motion of said communication device in the plane parallel to the side plane of said communication device optionally using said vertical switch as a pivotal point for facilitating the side tilting motion. Still further according to the second aspect of the invention, said communication device mounted on said cradle may be a mobile device or a mobile phone. According further to the second aspect of the invention, the cradle may be attached to a car dashboard or to a handle bar of a bicycle. The present invention describes an alternative to an acceleration-sensing method that is more robust and more suitable for all driving conditions with a bike or a car. Since the tilting of the phone is sensed by mechanical switches, the solution is much less prone to external accelerations. The mechanical switches also give a tactile feedback to the user, which is helpful since other feedback types may be absent (especially a visual feedback is limited by a visual attention to a surrounding traffic). | 20040217 | 20060704 | 20050818 | 94626.0 | 0 | BEAMER, TEMICA M | MECHANICAL INTERACTION WITH A PHONE USING A CRADLE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,781,045 | ACCEPTED | Distributed cardiac activity monitoring with selective filtering | System and techniques for distributed monitoring of cardiac activity include selective T wave filtering. In general, in one implementation, a distributed cardiac activity monitoring system includes a monitoring apparatus, with a selectively activated T wave filter, and a monitoring station. The monitoring apparatus can include a communications interface, a real-time QRS detector, a T wave filter, and a selector that activates the T wave filter to preprocess a cardiac signal provided to the real-time QRS detector in response to a message. The monitoring station can communicatively couple with the monitoring apparatus, over a communications channel, via the communications interface and can transmit the message to the monitoring apparatus to activate the T wave filter based at least in part upon a predetermined criteria (e.g., abnormal T waves for an individual, as identified by a system operator). | 1. A machine-implemented method comprising: identifying heart beats in a sensed cardiac signal; activating a T wave filter, used in said identifying heart beats, in response to a message from a monitoring station generated at least in part based upon discovery of a predetermined characteristic in the sensed cardiac signal; and outputting information corresponding to the identified heart beats to a communications channel of a distributed cardiac activity monitoring system. 2. The method of claim 1, wherein said identifying heart beats comprises identifying R waves in the sensed cardiac signal. 3. The method of claim 1, further comprising sending at least a portion of the sensed cardiac signal to the monitoring station, and wherein the discovery of the predetermined characteristic comprises identification of a tall T wave in the at least a portion of the sensed cardiac signal by an operator at the monitoring station. 4. The method of claim 1, wherein said activating the T wave filter comprises activating a filter that reduces signal amplitude at low frequencies of the sensed cardiac signal. 5. The method of claim 4, wherein the filter has a frequency response of about 0 dB or more at frequencies above ten Hertz. 6. The method of claim 5, wherein the filter has a frequency response of about −10 dB or less in a low frequency range of zero to five Hertz. 7. The method of claim 6, wherein the filter has a frequency response of about +2 dB or more in a high frequency range of twenty to twenty five Hertz. 8. The method of claim 1, wherein said outputting information comprises outputting heart rate data to a wireless communications channel. 9. The method of claim 1, further comprising: determining that an abnormal T wave is possible based on signal morphology analysis; and notifying a system operator of the possible abnormal T wave. 10. The method of claim 1, further comprising deactivating the T wave filter in response to a second message. 11. A distributed cardiac activity monitoring system comprising: a monitoring apparatus including a communications interface, a real-time QRS detector, a T wave filter, and a selector that activates the T wave filter with respect to the real-time QRS detector in response to a message, wherein the activated T waver filter preprocesses a cardiac signal provided to the real-time QRS detector; and a monitoring station that communicatively couples with the monitoring apparatus via the communications interface and transmits the message to the monitoring apparatus to activate the T wave filter based at least in part upon a predetermined criteria. 12. The system of claim 11, wherein the communications interface comprises a wireless communications interface. 13. The system of claim 11, wherein the T wave filter comprises a filter that reduces signal amplitude at low frequencies. 14. The system of claim 13, wherein the filter has a frequency response of about −10 dB or less in a low frequency range of zero to five Hertz. 15. The system of claim 13, wherein the filter has a frequency response of about 0 dB or more at frequencies above ten Hertz. 16. The system of claim 15, wherein the filter has a frequency response of about +2 dB or more in a high frequency range of twenty to twenty five Hertz. 17. The system of claim 11, wherein the selector comprises analog, selective activation circuitry. 18. The system of claim 11, wherein the monitoring apparatus further comprises additional logic that determines if an abnormal T wave is possible based on signal morphology analysis, and notifies a system operator of the possible abnormal T wave. 19. The system of claim 11, wherein the monitoring station further comprises additional logic that determines if an abnormal T wave is possible based on signal morphology analysis, and notifies a system operator of the possible abnormal T wave. 20. A cardiac monitoring apparatus comprising: a communications interface; a real-time heart beat detector; a T wave filter; and a selector that activates the T wave filter with respect to the real-time heart beat detector in response to a message, wherein the activated T waver filter preprocesses a cardiac signal provided to the real-time heart beat detector. 21. The apparatus of claim 20, wherein the communications interface comprises a wireless communications interface. 22. The apparatus of claim 20, wherein the real-time heart beat detector comprises an analog heart beat detector, the T wave filter comprises an analog T wave filter, and the selector comprises analog, selective activation circuitry. 23. The apparatus of claim 20, wherein the T wave filter comprises a filter that reduces signal amplitude at low frequencies. 24. The apparatus of claim 23, wherein the filter has a frequency response of about −10 dB or less in a low frequency range of zero to five Hertz. 25. The apparatus of claim 24, wherein the filter has a frequency response of about 0 dB or more at frequencies above ten Hertz. 26. The apparatus of claim 25, wherein the filter has a frequency response of about +2 dB or more in a high frequency range of twenty to twenty five Hertz. 27. The apparatus of claim 20, further comprising additional logic that determines if an abnormal T wave is possible based on signal morphology analysis, and notifies a system operator of the possible abnormal T wave. 28. A method comprising: receiving at least a portion of a sensed cardiac signal from a monitoring apparatus in contact with a living being under active cardiac monitoring; identify an abnormal T wave in the received cardiac signal; and sending a message to the monitoring apparatus over a communications channel, the message causing the monitoring apparatus to activate a T wave filter used in identifying heart beats of the living being under active cardiac monitoring. 29. The method of claim 23, further comprising: determining that an abnormal T wave is possible based on signal morphology analysis; and notifying a system operator of the possible abnormal T wave, wherein the system operator performs said identifying the abnormal T wave. 30. The method of claim 23, wherein said sending the message comprises sending the message over a wireless communications channel. 31. The method of claim 23, further comprising installing the T wave filter into the monitoring apparatus, which comprises a preexisting beat detector. 32. A system comprising: means for identifying heart beats in a sensed cardiac signal; means for filtering the sensed cardiac signal to reduce T waves in the sensed cardiac signal; and means for selectively activating the means for filtering in response to discovery of a predetermined characteristic in the sensed cardiac signal. 33. The system of claim 32, further comprising means for alerting a system operator of a possible abnormal T wave. 34. The system of claim 32, wherein the means for filtering comprises means for generally highpass filtering. | BACKGROUND The present application describes systems and techniques relating to monitoring cardiac activity, for example, processing cardiac electrical activity to determine heart rate. The electrical activity of the heart can be monitored to track various aspects of the functioning of the heart. Given the volume conductivity of the body, electrodes on the body surface or beneath the skin can display potential differences related to this activity. Anomalous electrical activity can be indicative of disease states or other physiological conditions ranging from benign to fatal. Cardiac monitoring devices can sense the cardiac electrical activity of a living being and identify heart beats. Frequently, identification of heart beats is performed by identifying the R waves in the QRS complex, as can be seen in an electrocardiogram (ECG). The R wave is the first positive deflection in the QRS complex, representing ventricular depolarization. The typically large amplitude of this positive deflection in the QRS complex is useful in identifying a heart beat. SUMMARY In general, in one aspect, a distributed cardiac activity monitoring system includes a monitoring apparatus, with a selectively activated T wave filter, and a monitoring station. The monitoring apparatus can include a communications interface, a real-time QRS detector, a T wave filter, and a message-activated selector that activates the T wave filter with respect to the real-time QRS detector to preprocess a cardiac signal provided to the real-time QRS detector. The monitoring station can communicatively couple with the monitoring apparatus, over a communications channel, via the communications interface and can transmit the message to the monitoring apparatus to activate the T wave filter based at least in part upon a predetermined criteria (e.g., abnormal T waves for an individual, as identified by a system operator). The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features and advantages will become apparent from the description, the drawings, and the claims. DRAWING DESCRIPTIONS FIG. 1 illustrates a distributed cardiac activity monitoring system in which a cardiac signal is monitored for medical purposes. FIG. 2 illustrates an example cardiac monitoring apparatus used with a living being. FIG. 3 illustrates an example ECG of a normal patient. FIG. 4 illustrates an example ECG of a patient with abnormal T waves. FIG. 5 illustrates a process of selectively activating a T wave filter. FIG. 6 illustrates a frequency response of an example T wave filter. FIG. 7 illustrates an impulse response of an example T wave filter. FIG. 8 illustrates an example distributed process for selectively activating a T wave filter. DETAILED DESCRIPTION FIG. 1 illustrates a distributed cardiac activity monitoring system 100 in which a cardiac signal is monitored for medical purposes. A living being 110 (e.g., a human patient, including potentially a healthy patient for whom cardiac monitoring is nonetheless deemed appropriate) has a cardiac monitoring apparatus 120 configured to obtain cardiac signals from the patient's heart. The cardiac monitoring apparatus 120 can be composed of one or more devices, such as a sensing device 122 and a processing device 124. The cardiac monitoring apparatus 120 can communicate with a monitoring station 140 (e.g., a computer in a monitoring center) via a communications channel 130. The cardiac monitoring apparatus 120 can include one or more sensing, calibration, signal processing, control, data storage, and transmission elements suitable for generating and processing the cardiac signal, as well as for relaying all or a portion of the cardiac signal over the communications channel 130. The communications channel 130 can be part of a communications network and can include any suitable medium for data transmission, including wired and wireless media suitable for carrying optical and/or electrical signals. The cardiac monitoring apparatus 120 can communicate sensed cardiac signals (e.g, ECG data), cardiac event information (e.g., real-time heart rate data), and additional physiological and/or other information to the monitoring station 140. The cardiac monitoring apparatus 120 can include an implantable medical device, such as an implantable cardiac defibrillator and an associated transceiver or pacemaker and an associated transceiver, or an external monitoring device that the patient wears. Moreover, the cardiac monitoring apparatus 120 can be implemented using, for example, the CardioNet Mobile Cardiac Outpatient Telemetry (MCOT) device, which is commercially available and provided by CardioNet, Inc of San Diego, Calif. The monitoring station 140 can include a receiver element for receiving transmitted signals, as well as various data processing and storage elements for extracting and storing information carried by transmissions regarding the state of the individual 110. The monitoring station 140 can be located in the same general location (e.g., in the same room, building or health care facility) as the monitoring apparatus 120, or at a remote location. The monitoring station 140 can include a display and a processing system, and a system operator 150 (e.g., a doctor or a cardiovascular technician) can use the monitoring station 140 to evaluate physiological data received from the cardiac monitoring apparatus 120. The system operator 150 can use the monitoring station 140 to change operational settings of the cardiac monitoring apparatus 120 remotely during active cardiac monitoring of the living being 110. Moreover, the cardiac monitoring apparatus 120 can selectively activate a T wave filter in response to discovery of a predetermined characteristic in the sensed cardiac signal, such as described further below. For example, the system operator can determine that the patient has consistently abnormal T waves and cause the monitoring station 140 to send a message to the monitoring apparatus 120 to activate the T wave filter. FIG. 2 illustrates an example cardiac monitoring apparatus 200 used with a living being. The apparatus 200 can include a sensor 210, a signal amplifier 220, a T wave filter 230, a selector 240, a beat detector 250, additional logic 260, and a communications interface 270. The sensor 210 can include two or more electrodes subject to one or more potential differences that yield a voltage signal, such as the signals illustrated in FIGS. 3 and 4. The electrodes can be body surface electrodes such as silver/silver chloride electrodes and can be positioned at defined locations to aid in monitoring the electrical activity of the heart. The sensor 210 can also include leads or other conductors that form a signal path to the signal amplifier 220. The signal amplifier 220 can receive and amplify the voltage signals. Furthermore, the signal amplifier 220 can include additional processing logic. For example, the additional processing logic can perform filtering and analog-to-digital conversion; the T wave filter 230 can be integrated into the signal amplifier 220. Additional processing logic can also be implemented elsewhere in the apparatus 200, and the amplification and other additional processing can occur before or after digitization. The signal amplifier 220 can provide an amplified and processed signal to the T wave filter 230 and to the selector 240. Moreover, some of the additional processing logic discussed in connection with FIG. 2 can also be implemented in the monitoring station 140. The various components of the apparatus 200 can be implemented as analog or digital components. For example, the selector 240 can be analog, selective activation circuitry that selects one of its two inputs (from the signal amplifier 220 and from the T wave filter 230) to be provided to the beat detector 250. Alternatively, the selector 240 can enable and disable the T wave filter 230 (e.g., the T wave filter 230 can be integrated into the beat detector 250 and turned on and off as needed). In general, the selector 240 activates the T wave filter 230 with respect to the heart beat detector 250, to preprocess the signal, in response to a message (e.g., a message received from the monitoring station 140 or a message generated within the apparatus 200). The beat detector 250 is a component (e.g., analog circuitry or digital logic) that identifies the time period between ventricular contractions. For example, the beat detector 250 can be a real-time QRS detector that identifies successive QRS complexes, or R waves, and determines the beat-to-beat timing in real time (i.e., output data is generated directly from live input data). The beat-to-beat timing can be determined by measuring times between successive R-waves. The beat detector 250 can provide information regarding the time period between ventricular contractions to additional logic 260. The additional logic 260 can include logic to determine if an abnormal T wave potentially is occurring based on signal morphology analysis, an atrial fibrillation/atrial flutter (AF) detector, AF decision logic, and an event generator. The heart rate information can be transmitted using the communications interface 270, which can be a wired or wireless interface. Moreover, the sensed cardiac signal, or portions thereof, can be sent to a monitoring station, periodically, upon being interrogated and/or in response to identified events/conditions. The morphology of a cardiac signal can vary significantly from patient to patient. Sometimes, the patient's ECG has a very tall T wave, which might result in false classification of this T wave as an R wave. When this happens, the heart rate reported by the apparatus may be twice the real heart rate, and the morphology of beats may not be detected correctly. The T wave filter 230 can reduce the amplitude of T waves, while preserving or slightly increasing the amplitude of R waves. FIG. 3 illustrates an example ECG 300 of a normal patient. The heart cycle has four generally recognized waveforms: the P wave, the QRS complex, the T wave, and the U wave. The relative sizes of a QRS complex 310 and a T wave 320 represent the signal from a typical heart. FIG. 4 illustrates an example ECG 400 of a patient with abnormal T waves. As shown, a T wave 420 is tall in comparison with a normal T wave 320, and the rest of the cardiac cycle looks the same. In general, abnormal T waves can result in misclassification of T waves as R waves. In these cases, the T wave filter can be selectively applied to improve cardiac monitoring performance. The reduction in amplitude of the T wave may be up to 80% (five times) and can thus create a significant increase in the accuracy of QRS detection in patients with abnormal T waves. FIG. 5 illustrates a process of selectively activating a T wave filter. Heart beats are identified in sensed cardiac signals at 500. A T wave filter is selectively activated in response to discovery of a predetermined characteristic in the sensed cardiac signal at 510. The discovery of the predetermined characteristic can involve an operator's identification of a tall T wave in at least a portion of the sensed cardiac signal, and activating the T wave filter can improve the cardiac monitoring. After filter activation, heart beats are identified in sensed cardiac signals using the activated T wave filter at 520. The T wave filter can be a custom highpass-like filter. The filter can be such that it reduces signal amplitude at low frequencies of the sensed cardiac signal and increases signal amplitude at high frequencies of the sensed cardiac signal. FIG. 6 illustrates a frequency response 600 of an example T wave filter. As shown, the filter's frequency response can be less than or equal to −10 dB in the low frequency range of 0-5 Hertz (Hz). This frequency range is where T wave power spectrum is predominantly located. At higher frequencies, the filter can preserve and/or increase the amplitude of the signal (e.g., modify the signal by 0 dB or more for frequencies above 10 Hz), which can increase the amplitude of the R wave and make the beat detection more reliable. As shown, the filter's frequency response can be +2 dB or more in a high frequency range of 20-25 Hz. FIG. 7 illustrates an impulse response 700 of the example T wave filter illustrated in FIG. 6. FIG. 8 illustrates an example distributed process for selectively activating a T wave filter. Heart beats are identified in a sensed cardiac signal at 800. The cardiac signal can be from a monitoring apparatus in contact with a living being under active cardiac monitoring, as described above. A possibly abnormal T wave can be determined in a post-processing operation that analyzes signal morphology, and a system operator can be notified of the possible abnormal T wave at 805; this operation can alternatively be done at the monitoring station, as mentioned below. This can assist the operator in identifying patients that may benefit from having the T wave filter activated in their monitors. Additionally, the operator can proactively check the sensed cardiac signal from the monitor to assess the T waves. At least a portion of the sensed cardiac signal can be sent to a monitoring station at 810. This can involve continuously or periodically sending the cardiac signal, or sending the cardiac signal in response to identified events/conditions, such as the identification of the possible abnormal T wave at 805. The sensed cardiac signals are received from the monitoring apparatus at 815. A possibly abnormal T wave can be determined using a signal morphology analyzer, and a system operator can be notified of the possible abnormal T wave at 820. An abnormal T wave can be identified, such as by a system operator, in the received cardiac signal at 825, and a message can be sent to the monitoring apparatus over a communications channel at 830. The message causes the monitoring apparatus to activate a T wave filter used in identifying heart beats of the living being under active cardiac monitoring. The T wave filter is activated in response to the message at 835. Information corresponding to the heart beats identified using the T wave filter (e.g., heart rate data) can be output to the communications channel at 840. This information can be received at the monitoring station at 845. Moreover, if the system operator subsequently determines that the T wave filter is not needed for the patient, a message to deactivate the T wave filter can be sent at 850, and the T wave filter can be deactivated in response to this second message at 855. The T wave filter may not distinguish morphology of the beat. Therefore, slow ventricular beats, such as premature ventricular contractions (PVCs), or some ectopic beats may also be reduced in amplitude when the filter is applied. In cases where multiple PVCs are monitored, the T wave filter may reduce the amplitude of these beats, and thus a pause or asystole event may be generated, which generally should alert the system operator to deactivate the T wave filter. However, this may not be relevant in the particular application as many cardiac monitoring applications do not require monitoring of PVCs or ectopic beats. Fast ventricular beats (with a rate over 100 beats per minute) may be left unchanged by the T wave filter because their power spectrum is usually above 10 Hz. The T wave filter described can be installed into a monitoring apparatus that includes a preexisting beat detector. The T wave filter can preprocess the input provided to the preexisting beat detector, improving the functioning of the beat detector for individuals with abnormal T waves, even though the preexisting beat detector was designed without a T wave filter in mind. The T wave filter can be in a disabled state by default and may be turned on only for the monitors used with those individuals with abnormal T waves (e.g., patients whose cardiac signal features constant tall T waves). The systems and techniques described and illustrated in this specification can be implemented in analog electronic circuitry, digital electronic circuitry, integrated circuitry, computer hardware, firmware, software, or in combinations of the forgoing, such as the structural means disclosed in this specification and structural equivalents thereof. Apparatus can be implemented in a software product (e.g., a computer program product) tangibly embodied in a machine-readable storage device for execution by a programmable processor, and processing operations can be performed by a programmable processor executing a program of instructions to perform functions by operating on input data and generating output. Further, the system can be implemented advantageously in one or more software programs that are executable on a programmable system. This programmable system can include the following: 1) at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system; 2) at least one input device; and 3) at least one output device. Moreover, each software program can be implemented in a high-level procedural or object-oriented programming language, or in assembly or machine language if desired; and in any case, the language can be a compiled or an interpreted language. Also, suitable processors include, by way of example, both general and special purpose microprocessors. Generally, a processor will receive instructions and data from a read-only memory, a random access memory, and/or a machine-readable signal (e.g., a digital signal received through a network connection). Generally, a computer will include one or more mass storage devices for storing data files. Such devices can include magnetic disks, such as internal hard disks and removable disks, magneto-optical disks, and optical disks. Storage devices suitable for tangibly embodying software program instructions and data include all forms of non-volatile memory, including, by way of example, the following: 1) semiconductor memory devices, such as EPROM (electrically programmable read-only memory); EEPROM (electrically erasable programmable read-only memory) and flash memory devices; 2) magnetic disks such as internal hard disks and removable disks; 3) magneto-optical disks; and 4) optical disks, such as CD-ROM disks. Any of the foregoing can be supplemented by, or incorporated in, ASICs (application-specific integrated circuits). To provide for interaction with a user (such as the system operator), the system can be implemented on a computer system having a display device such as a monitor or LCD (liquid crystal display) screen for displaying information to the user and a keyboard and a pointing device such as a mouse or a trackball by which the user can provide input to the computer system. The computer system can be programmed to provide a graphical user interface through which computer programs interact with users and operational settings can be changed in the monitoring system. Finally, while the foregoing system has been described in terms of particular implementations, other embodiments are within the scope of the following claims. | <SOH> BACKGROUND <EOH>The present application describes systems and techniques relating to monitoring cardiac activity, for example, processing cardiac electrical activity to determine heart rate. The electrical activity of the heart can be monitored to track various aspects of the functioning of the heart. Given the volume conductivity of the body, electrodes on the body surface or beneath the skin can display potential differences related to this activity. Anomalous electrical activity can be indicative of disease states or other physiological conditions ranging from benign to fatal. Cardiac monitoring devices can sense the cardiac electrical activity of a living being and identify heart beats. Frequently, identification of heart beats is performed by identifying the R waves in the QRS complex, as can be seen in an electrocardiogram (ECG). The R wave is the first positive deflection in the QRS complex, representing ventricular depolarization. The typically large amplitude of this positive deflection in the QRS complex is useful in identifying a heart beat. | <SOH> SUMMARY <EOH>In general, in one aspect, a distributed cardiac activity monitoring system includes a monitoring apparatus, with a selectively activated T wave filter, and a monitoring station. The monitoring apparatus can include a communications interface, a real-time QRS detector, a T wave filter, and a message-activated selector that activates the T wave filter with respect to the real-time QRS detector to preprocess a cardiac signal provided to the real-time QRS detector. The monitoring station can communicatively couple with the monitoring apparatus, over a communications channel, via the communications interface and can transmit the message to the monitoring apparatus to activate the T wave filter based at least in part upon a predetermined criteria (e.g., abnormal T waves for an individual, as identified by a system operator). The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features and advantages will become apparent from the description, the drawings, and the claims. | 20040217 | 20060829 | 20050818 | 68998.0 | 1 | LEE, YUN H | DISTRIBUTED CARDIAC ACTIVITY MONITORING WITH SELECTIVE FILTERING | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,781,200 | ACCEPTED | Metadata access during error handling routines | A data storage control unit is coupled to one or more host devices and to one or more physical storage units. Data is stored in one of the storage units and, for data integrity, copied to another storage unit. An updated state of the copy process (metadata) is maintained and updated in metadata tracks in a memory of the storage controller and periodically destaged to corresponding metadata tracks of a storage unit. If the copy process is interrupted, such as by a power failure, an error handling routine commences. Track state fields associated with each in-memory metadata track are initialized to an ‘invalid’ state and background staging of metadata tracks from the storage unit to the memory. After a track is staged, the associated track state field is changed to a ‘valid’ state. If a request is received to access a track of copy state data and the track has been staged (as indicated by the state of the associated track state field), the track is accessed. If the requested track has not been staged, requester waits while the requested track is staged; then the requested track is accessed. Once the error handling routine is completed, normal I/O operations with customer data may resume. Preferably, completion of the error handling routine is independent of the completion of the staging of copy state data tracks. | 1. A method for initializing a storage controller, comprising: commencing an initial microcode load (IML) operation; commencing background staging of copy state data tracks from a disk storage device to a memory device; receiving a request to access a track of copy state data; if the requested track of copy state data has been staged, accessing the requested track of copy state data; if the requested track of copy state data has not been staged: issuing a wait command in response to the request to access the track of copy state data; staging the requested track of copy state data; revoking the wait command; and accessing the requested track of copy state data; completing the staging of the copy state data tracks; and completing the IML. 2. The method of claim 1, further comprising initializing a parameter in a field of the tracks of copy state data to a first state when the IML is commenced; and changing the state of the parameter of a track to a second state when copy state data is staged to the memory device. 3. The method of claim 2, further comprising, when the request to access the track of copy state data is received: if the parameter is in the second state, allowing access to the requested track; and if the parameter is in the first state: staging the requested track; and allowing access to the requested track. 4. The method of claim 3, wherein completion of the IML is independent of completion of the staging of all copy state data tracks. 5. A method for processing metadata in a data storage controller, comprising: executing a copy service operation; maintaining a current state of the copy services operation in a memory device; periodically destaging the current state of the copy services operation from the memory device to a plurality of metadata tracks on a storage device; following commencement of an error handling routine, commencing background staging of the metadata tracks from the storage device to the memory device; receiving a request to access a metadata track; if the requested metadata track has been staged, allowing access to the requested metadata track; if the requested metadata track has not been staged: issuing a wait command in response to the request to access the metadata track; staging the requested metadata track; revoking the wait command; and accessing the requested metadata track; completing the staging of the metadata tracks; and completing the error handling routine. 6. The method of claim 5, further comprising initializing a parameter in a field in each of the metadata tracks to a first state when the error handling routine is commenced; and changing the state of the parameter of a metadata track to a second state when the metadata is staged to the memory device. 7. The method of claim 6, further comprising, when the request to access the metadata track is received: if the parameter is in the second state, allowing access to the requested track; and if the parameter is in the first state: staging the requested track; and allowing access to the requested track. 8. The method of claim 5, wherein the error handling routine is an initial microcode load. 9. The method of claim 5, wherein completion of the error handling routine is independent of completion of the staging of metadata. 10. A method for processing metadata in a data storage controller, comprising: executing a copy service operation; maintaining a current state of the copy services operation in a memory device; periodically destaging the current state of the copy services operation from the memory device to a plurality of metadata tracks on a storage device; following commencement of an error handling routine, initializing a parameter in a field of each of the metadata tracks to a first state; commencing background staging of the metadata tracks from the storage device to the memory device; changing the state of the parameter of a metadata track to a second state when the metadata track is staged to the memory device. receiving a request to access a metadata track; if the parameter is in the second state, allowing access to the requested metadata track; if the parameter is in the first state: issuing a wait command in response to the request to access the metadata track; staging the requested metadata track; revoking the wait command; and allowing access to the requested metadata track; and completing the error handling routine. 11. The method of claim 10, wherein the error handling routine is an initial microcode load. 12. The method of claim 10, wherein completing the error handling routine is independent of completion of the staging of metadata tracks. 13. A storage controller, comprising: means for receiving customer data from a host device; means for storing the customer data onto a first storage device; means for copying the customer data onto a second storage device in a copying operation; a memory device for storing a current state of the copying operation as a plurality of metadata tracks; means for periodically destaging the metadata tracks to a selected one of the first and second storage devices; and means for processing an error handling routine following an interruption in the copying operation, comprising: means for initializing a parameter of each metadata track in the memory device to a first state; means for commencing background staging of the metadata tracks from the selected storage device to the memory device; means for changing the state of the parameter of a metadata track to a second state when the metadata track is staged to the memory device; means for receiving a request to access a metadata track; means for allowing access to the requested metadata track if the parameter of the requested metadata track is in the second state; if the parameter of the requested metadata track is in the first state: means for issuing a wait command in response to the request to access the metadata track; means for staging the requested metadata track to the memory device; means for revoking the wait command; and means for allowing access to the requested metadata track; and means for completing the error handling routine. 14. The storage controller of claim 13, wherein the error handling routine is an initial microcode load. 15. The storage controller of claim 13, wherein the means for completing the error handling routine comprises means for completing the error handling routine independent of completion of the staging of metadata tracks. 16. A copy services component of a data storage controller, the copy services component comprising: means for directing that customer data be copied onto a storage device in a copy operation; a plurality of data structures for collectively maintaining a current state of the copy operation; an interface through which copies of the data structures are periodically destaged to the storage device; means for processing an error handling routine following an interruption in the copy operation, comprising: means for initializing a parameter of each metadata track in the memory device to a first state; means for commencing background staging of the metadata tracks from the selected storage device to the memory device; means for changing the state of the parameter of a metadata track to a second state when the metadata track is staged to the memory device. means for receiving a request to access a metadata track; means for allowing access to the requested metadata track if the parameter of the requested metadata track is in the second state; if the parameter of the requested metadata track is in the first state: means for issuing a wait command in response to the request to access the metadata track; means for staging the requested metadata track to the memory device; means for revoking the wait command; and means for allowing access to the requested metadata track; and means for completing the error handling routine. 17. The copy services component of claim 16, wherein the error handling routine is an initial microcode load. 18. The copy services component of claim 16, wherein the means for completing the error handling routine comprises means for completing the error handling routine independent of completion of the staging of metadata tracks. 19. A data structure stored in a memory of a data storage controller, the storage controller coupled to a first storage device storing customer data and to a second storage device storing a copy of the customer data, the data structure comprising: a first field for storing a portion of a current state of an active copy operation, the portion being periodically destaged to one of the first and second storage devices; and a track state field having a first state indicative of invalid contents in the first field and a second state indicative of valid contents in the first field; wherein: following commencement of an error handling routine, a background staging commences of the track from the storage device to the memory device; when a request is received to access the first field: if the first field has been staged, access is allowed to the track; if the first field has not been staged: a wait command is issued in response to the request to access the first field; the first field is staged; the wait command is revoked; and the first field is accessed; and the error handling routine is completed. 20. The data structure of claim 19, wherein further: the track state field is initialized to the first state when the error handling routine is commenced; and the state of the track state field is changed to the second state when the first field is staged to the memory device. 21. The data structure of claim 20, wherein further, when the request to access a track is received: if the track state field is in the second state, access to the first field is allowed; and if the track state field is in the first state: the first field is staged; and access to the first field is allowed. 22. The data structure of claim 19, wherein further, completion of the error handling routine is independent of completion of the staging of other data structures. 23. A computer program product of a computer readable medium usable with a programmable computer, the computer program product having computer-readable code embodied therein for initializing a storage controller, the computer-readable code comprising instructions for: commencing an initial microcode load (IML) operation commencing background staging of copy state data tracks from a disk storage device to a memory device; receiving a request to access a track of copy state data; if the requested track of copy state data has been staged, accessing the requested track of copy state data; if the requested track of copy state data has not been staged: issuing a wait command in response to the request to access the track of copy state data; staging the requested track of copy state data; revoking the wait command; and accessing the requested track of copy state data; completing the staging of the copy state data tracks; and completing the IML. 24. The computer program product of claim 23, wherein the instructions further comprise instructions for: initializing a parameter in a field of the tracks of copy state data to a first state when the IML is commenced; and changing the state of the parameter of a track to a second state when copy state data is staged to the memory device. 25. The computer program product of claim 24, wherein the instructions further comprise instructions for, when the request to access the track of copy state data is received: if the parameter is in the second state, allowing access to the requested track; and if the parameter is in the first state: staging the requested track; and allowing access to the requested track. 26. The computer program product of claim 25, wherein completion of the IML is independent of completion of the staging of all copy state data tracks. | TECHNICAL FIELD The present invention relates generally to backup and disaster recovery services for a data storage system and, in particular, to improving the efficiency of error handling routines following the interruption of a data copy operation. BACKGROUND ART High end storage controllers, such as the International Business Machines Corporation (IBM®) Enterprise Storage Server® manage Input/Output (I/O) requests from networked hosts to one or more storage units, such as a direct access storage device (DASD), Redundant Array of Independent Disks (RAID Array), and Just a Bunch of Disks (JBOD). Storage controllers include one or more host bus adapters or interfaces to communicate with one or more hosts over a network and adapters or interfaces to communicate with the storage units. Data integrity is a critical factor in large computer data systems. Consequently, backup systems have been developed and integrated into storage controller to prevent the loss of data in the event of various types of failures. Backup systems provided by IBM, known generally as “copy services”, include Peer-to-Peer Remote Copy, FlashCopy® and Extended Remote Copy and maintain a separate, consistent copy of customer data. As illustrated in FIG. 1, in a storage system 100, data generated by a host device 110 is transmitted to a primary storage unit 120 for storage on associated storage devices 130. A copy of the data is also transmitted, such as over a fibre channel network 140, and to a secondary storage unit 150 for storage on associated storage devices 160. Because of the flexibility of network interconnections, the primary and secondary units 120 and 150 may be physically located remote from the host 110. And, for additional data security, the primary and secondary units 120 and 150 may be (but need not be) physically located distant from each other, thereby reducing the likelihood of a single disaster simultaneously harming both the primary and secondary units 120 and 150. It will be appreciated that the primary and secondary units 120 and 150 may be the same physical unit, divided logically into two. Due at least in part to the risk of a power loss or other comparable significant event while customer data is being copied to the secondary unit, the state of the copy services operation is stored in memory and updated as the copy services operation progresses. The state data (as well as other control information used internally by the storage controller), known as “metadata”, is periodically destaged from the memory to reserved areas of the customer storage devices 130. Preferably, the metadata is divided into tracks of, for example, 8 KB each. There may be as many as 2000 or more such tracks. During an error handing routine or behavior (EHB), such as an internal microcode load (IML), following a power loss during a copy services operation or other comparable significant event, the metadata is staged from the storage device to the memory where it becomes available for the recovery operation. In a conventional EHB, other EHB activities must be paused while all of the metadata tracks are staged to memory. Only after all of the metadata has been staged may the EHB be completed and normal customer I/O operations resumed. Consequently, the requirement to stage all of the metadata tracks delays completion of the EHB and adversely impacts customer I/O. Consequently a need remains for improving the performance of metadata recovery during EHB activities without adversely affecting customer operations. SUMMARY OF THE INVENTION The present invention provides a method for initializing a data storage controller. Following commencement of an IML, copy state data tracks are background staged from a disk storage device to a memory device. If a request is received to access a track of copy state data and the track has been staged, the track is accessed. If the requested track has not been staged, requester waits while the requested track is staged; then the requested track is accessed. Preferably, completion of the IML is independent of the completion of the staging of copy state data tracks. The present invention further provides methods for processing metadata in a storage controller. During a copy services operation, the current state of the operation is maintained in a memory device. Periodically, the current state is destaged to metadata tracks on a storage device. Following commencement of an error handling routine, copy state data tracks are background staged from a disk storage device to a memory device. If a request is received to access a track of copy state data and the track has been staged, the track is accessed. If the requested track has not been staged, the requester waits while the requested track is staged; then the requested track is accessed. Preferably, completion of the error handling routine is independent of the completion of the staging of copy state data tracks. The present invention further provides a data storage controller, including a memory device for storing a current state of a copying operation as metadata tracks and means for processing an error handling routine. The means for processing an error handling routine includes means for initializing a parameter of each metadata track to a first state, means for commencing background staging of the metadata tracks and means for changing the state of the parameter to a second state when a track is staged. If a request is received to access a track of copy state data and the corresponding parameter indicates that the track has been staged, the track is accessed. If the corresponding parameter indicates that the requested track has not been staged, the requester waits while the requested track is staged; then the requested track is accessed. Completion of the error handling routine is independent of the completion of the staging of copy state data tracks. The present invention further provides a copy services component of a data storage controller, including means for processing error handling routines. The means for processing error handling routines includes means for initializing a parameter of each metadata track to a first state, means for commencing background staging of the metadata tracks and means for changing the state of the parameter to a second state when a track is staged. If a request is received to access a track of copy state data and the corresponding parameter indicates that the track has been staged, the track is accessed. If the corresponding parameter indicates that the requested track has not been staged, the requester waits while the requested track is staged; then the requested track is accessed. Completion of the error handling routine is independent of the completion of the staging of copy state data tracks. The present invention further provides a data structure in a memory of a data storage controller, including a first field for storing a portion of a current state of an active copy operation, the portion being periodically destaged to a storage device. The data structure further includes a track state field having a first state indicative of invalid contents in the first field and a second state indicative of valid contents in the first field. Following commencement of an error handling operation, a background staging commences of the first field from the storage device to a memory device. When a request is received to access the first field, if the first field has been staged, access is allowed to the first field. If the first field has not been staged, a wait command is issued in response to the request to access the first field, the first field is staged, the wait command is revoked and the first field is accessed. The present invention further provides a computer program product having computer-readable for initializing a storage controller. The computer-readable code includes instructions for commencing an IML, background staging copy state data tracks from a disk storage device to a memory device. If a request is received to access a track of copy state data and the track has been staged, the track is accessed. If the requested track has not been staged, requester waits while the requested track is staged; then the requested track is accessed. Preferably, completion of the IML is independent of the completion of the staging of copy state data tracks. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a data storage system in which the present invention may be implemented; FIG. 2 is a block diagram of a storage controller in which the present invention may be implemented; and FIGS. 3 and 4 are flow charts of one implementation of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 2 is a block diagram of a primary data storage controller 200 in which the present invention may be implemented. The controller 200 is coupled through appropriate adapters or interfaces to one or more host devices and to one or more physical storage units 250, such as disk storage devices, and to a secondary storage controller. The controller 200 includes a memory device 210 and a processor 220. The memory 210 includes an area in which metadata tracks 212 are stored. A first part 212A of each metadata track 212 is allocated to storing the current state of a copy services operation. A second part of each in-memory metadata track 212 is allocated to a track state field 212B. As will be described, each track state field 212B contains a flag whose state (staged (valid) or unstaged (invalid)) is indicative of the status of the metadata in the corresponding first part 212A of the track 212. Similarly, the attached storage device 250 includes an area in which copies 252 of the metadata tracks are stored in a non-volatile manner. Referring also to the flow chart of FIG. 3, an implementation of the present invention will be described, under the control of program instructions executed in the processor 220. A copy services operation (such as a Peer-to-Peer Remote Copy, a FlashCopy® or an Extended Remote Copy) commences (step 300) to copy customer data from the primary storage controller 120 to the secondary storage controller 150. The details of such copy operations are known in the art and covered by other IBM patents and will not be described herein. The current state of the copy services operation is stored as part of metadata 212 in the memory 210 (step 302). Periodically, the current state is destaged from the memory 210 to metadata tracks 252 in the storage device 250. Such destaging may occur, for example, at regular time intervals, when the copy state is updated (step 306) or at other designated times. Eventually, the copy services operation is completed (step 308). As noted above, there are circumstances, such as a power failure, software bug, hardware failure or other comparable significant event, which interrupt a copy services operation and prevent its completion. Rather than re-start the operation from the beginning, further delaying normal operation of the storage system, an error handling routine is initiated (FIG. 4, step 400). The error handling routine, also known as error handling behavior (EHB), may include an initial microcode load (IML). The track state fields 212B of the in-memory metadata tracks 212 are initialized to a first of two states (step 402) indicating that the contents of the first part 212A of each track 212 (the part in which the copy state information is stored) is ‘invalid’. Next, staging of the metadata tracks 252 from the storage device 250 to the memory 210 is begun (step 404). However, in contrast to conventional error handling routines, in the present invention the metadata tracks are staged in the background, without interrupting or otherwise delaying other aspects of the error handling routine, thus increasing the speed with which normal operations of the storage system may resume. When a metadata track 252 has been staged to the first part 212A of an in-memory track 212, the associated track state field 212B is changed to ‘valid’ (step 406) and a next track is staged. Copy state information contained in the metadata tracks may need to be accessed during the error handling routine. If a request for a track is received (step 408), the track state field 212B of the requested track is examined (step 410). If the field 212B is in the ‘valid’ state, indicating that the metadata contents of the first part 212A have been staged from the storage device 250, access to the contents is allowed (step 412). However, if the field 212B is in the ‘invalid’ state, indicating that the metadata contents of the first part 212A have not yet been staged from the storage device 250, access to the contents is not allowed. Instead, a ‘wait’ command is issued (step 414), and the requested track is staged to the memory 210 out of sequence (step 416). Once staged, the track state field is changed to ‘valid’ (step 418), the ‘wait’ command is revoked (step 420) and access is allowed (step 412). During the subsequent staging of the remaining metadata tracks 252 (step 422), any track which has previously been staged out of sequence, as indicated by the ‘valid’ state of the track state field, will be skipped as re-staging is unnecessary. The error handling routine may continue to completion (step 424) without waiting for the staging of metadata tracks to complete (step 422). Thus, completion of the error handling routine and completion of staging the metadata tracks proceed independent of each other and normal customer I/O operations may commence as soon as the error handling routine is completed. The described techniques may be implemented as a method, apparatus or computer program product using standard programming and/or engineering techniques to produce software, firmware, hardware, or any combination thereof. The computer program product (such as the operating memory 138), as used herein, refers to code or logic implemented in hardware logic (e.g., an integrated circuit chip, Programmable Gate Array (PGA), Application Specific Integrated Circuit (ASIC), etc.) or a computer readable medium (e.g., magnetic storage medium such as hard disk drives, floppy disks, tape), optical storage (e.g., CD-ROMs, optical disks, etc.), volatile and non-volatile memory devices (e.g., EEPROMs, ROMs, PROMs, RAMs, DRAMs, SRAMs, firmware, programmable logic, etc.). Code in the computer readable medium is accessed and executed as instructions by a processor. The code in which implementations are made may further be accessible through a transmission media or from a file server over a network. In such cases, the computer program product in which the code is implemented may comprise a transmission media such as network transmission line, wireless transmission media, signals propagating through space, radio waves, infrared signals, etc. Of course, those skilled in the art will recognize that many modifications may be made to this configuration without departing from the scope of the implementations and that the computer program product may comprise any information bearing medium known in the art. The objects of the invention have been fully realized through the embodiments disclosed herein. Those skilled in the art will appreciate that the various aspects of the invention may be achieved through different embodiments without departing from the essential function of the invention. The particular embodiments are illustrative and not meant to limit the scope of the invention as set forth in the following claims. | <SOH> BACKGROUND ART <EOH>High end storage controllers, such as the International Business Machines Corporation (IBM®) Enterprise Storage Server® manage Input/Output (I/O) requests from networked hosts to one or more storage units, such as a direct access storage device (DASD), Redundant Array of Independent Disks (RAID Array), and Just a Bunch of Disks (JBOD). Storage controllers include one or more host bus adapters or interfaces to communicate with one or more hosts over a network and adapters or interfaces to communicate with the storage units. Data integrity is a critical factor in large computer data systems. Consequently, backup systems have been developed and integrated into storage controller to prevent the loss of data in the event of various types of failures. Backup systems provided by IBM, known generally as “copy services”, include Peer-to-Peer Remote Copy, FlashCopy® and Extended Remote Copy and maintain a separate, consistent copy of customer data. As illustrated in FIG. 1 , in a storage system 100 , data generated by a host device 110 is transmitted to a primary storage unit 120 for storage on associated storage devices 130 . A copy of the data is also transmitted, such as over a fibre channel network 140 , and to a secondary storage unit 150 for storage on associated storage devices 160 . Because of the flexibility of network interconnections, the primary and secondary units 120 and 150 may be physically located remote from the host 110 . And, for additional data security, the primary and secondary units 120 and 150 may be (but need not be) physically located distant from each other, thereby reducing the likelihood of a single disaster simultaneously harming both the primary and secondary units 120 and 150 . It will be appreciated that the primary and secondary units 120 and 150 may be the same physical unit, divided logically into two. Due at least in part to the risk of a power loss or other comparable significant event while customer data is being copied to the secondary unit, the state of the copy services operation is stored in memory and updated as the copy services operation progresses. The state data (as well as other control information used internally by the storage controller), known as “metadata”, is periodically destaged from the memory to reserved areas of the customer storage devices 130 . Preferably, the metadata is divided into tracks of, for example, 8 KB each. There may be as many as 2000 or more such tracks. During an error handing routine or behavior (EHB), such as an internal microcode load (IML), following a power loss during a copy services operation or other comparable significant event, the metadata is staged from the storage device to the memory where it becomes available for the recovery operation. In a conventional EHB, other EHB activities must be paused while all of the metadata tracks are staged to memory. Only after all of the metadata has been staged may the EHB be completed and normal customer I/O operations resumed. Consequently, the requirement to stage all of the metadata tracks delays completion of the EHB and adversely impacts customer I/O. Consequently a need remains for improving the performance of metadata recovery during EHB activities without adversely affecting customer operations. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides a method for initializing a data storage controller. Following commencement of an IML, copy state data tracks are background staged from a disk storage device to a memory device. If a request is received to access a track of copy state data and the track has been staged, the track is accessed. If the requested track has not been staged, requester waits while the requested track is staged; then the requested track is accessed. Preferably, completion of the IML is independent of the completion of the staging of copy state data tracks. The present invention further provides methods for processing metadata in a storage controller. During a copy services operation, the current state of the operation is maintained in a memory device. Periodically, the current state is destaged to metadata tracks on a storage device. Following commencement of an error handling routine, copy state data tracks are background staged from a disk storage device to a memory device. If a request is received to access a track of copy state data and the track has been staged, the track is accessed. If the requested track has not been staged, the requester waits while the requested track is staged; then the requested track is accessed. Preferably, completion of the error handling routine is independent of the completion of the staging of copy state data tracks. The present invention further provides a data storage controller, including a memory device for storing a current state of a copying operation as metadata tracks and means for processing an error handling routine. The means for processing an error handling routine includes means for initializing a parameter of each metadata track to a first state, means for commencing background staging of the metadata tracks and means for changing the state of the parameter to a second state when a track is staged. If a request is received to access a track of copy state data and the corresponding parameter indicates that the track has been staged, the track is accessed. If the corresponding parameter indicates that the requested track has not been staged, the requester waits while the requested track is staged; then the requested track is accessed. Completion of the error handling routine is independent of the completion of the staging of copy state data tracks. The present invention further provides a copy services component of a data storage controller, including means for processing error handling routines. The means for processing error handling routines includes means for initializing a parameter of each metadata track to a first state, means for commencing background staging of the metadata tracks and means for changing the state of the parameter to a second state when a track is staged. If a request is received to access a track of copy state data and the corresponding parameter indicates that the track has been staged, the track is accessed. If the corresponding parameter indicates that the requested track has not been staged, the requester waits while the requested track is staged; then the requested track is accessed. Completion of the error handling routine is independent of the completion of the staging of copy state data tracks. The present invention further provides a data structure in a memory of a data storage controller, including a first field for storing a portion of a current state of an active copy operation, the portion being periodically destaged to a storage device. The data structure further includes a track state field having a first state indicative of invalid contents in the first field and a second state indicative of valid contents in the first field. Following commencement of an error handling operation, a background staging commences of the first field from the storage device to a memory device. When a request is received to access the first field, if the first field has been staged, access is allowed to the first field. If the first field has not been staged, a wait command is issued in response to the request to access the first field, the first field is staged, the wait command is revoked and the first field is accessed. The present invention further provides a computer program product having computer-readable for initializing a storage controller. The computer-readable code includes instructions for commencing an IML, background staging copy state data tracks from a disk storage device to a memory device. If a request is received to access a track of copy state data and the track has been staged, the track is accessed. If the requested track has not been staged, requester waits while the requested track is staged; then the requested track is accessed. Preferably, completion of the IML is independent of the completion of the staging of copy state data tracks. | 20040217 | 20060829 | 20050901 | 96422.0 | 0 | GOODARZI, NASSER MOAZZAMI | METADATA ACCESS DURING ERROR HANDLING ROUTINES | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,781,376 | ACCEPTED | Cable connector with elastomeric band | A connector for a coaxial cable includes a connector body and a fastening member for connecting said connector to an object such as an equipment port. A post is fitted at least partially inside the connector body for receiving a prepared end of the cable. A compression member is fitted to a back of the connector body. An elastomeric band is fitted inside a cavity formed at least in part by the compression member. Axial movement of the compression member onto said connector body causes the elastomeric band to seal an outer layer of the cable to the connector to isolate the inside of the connector from environmental influences. | 1. A connector for a coaxial cable, comprising: a connector body; a fastening member for connecting said connector to an object; a post fitted at least partially inside said connector body for receiving a prepared end of said cable; a compression member fitted to said connector body; and an elastomeric band fitted inside a cavity formed at least in part by said compression member; wherein axial movement of said compression member onto said connector body causes said elastomeric band to deform and seal an outer layer of said cable to said connector to isolate an inside of said connector from environmental influences. 2. A connector according to claim 1, wherein said connector body, said compression member, and said fastening member are of plastic, and said post is of an electrically conductive material. 3. A connector according to claim 2, wherein said post includes a barbed portion disposed where said band seals against said cable. 4. A connector according to claim 1, wherein said post includes a barbed portion disposed where said band seals against said cable. 5. A connector according to claim 4, wherein said connector body, said compression member, said fastening member, and said post are all of metal. 6. A connector according to claim 1, wherein said post includes a barbed portion disposed where said band seals against said cable. 7. A connector for a coaxial cable, comprising: a connector body; first connection means for connecting said connector to an object; and second connection means for connecting a prepared end of said cable to said connector; wherein said second connection means includes an elastomeric band for sealing an outer layer of said cable to said connector to isolate an inside of said connector from environmental influences. 8. A connector according to claim 7, wherein said second connection means includes means for axially moving a compression member onto said connector body, and said elastomeric band is fitted inside a cavity formed at least in part by said compression member. 9. A connector according to claim 7, further comprising receiving means for receiving said prepared end of said cable inside said connector. 10. A connector according to claim 9, wherein said receiving means includes a barbed portion disposed where said band seals against said cable. 11. A connector according to claim 9, wherein said connector body, said first connection means, and said second connection means are of plastic, and said receiving means is of an electrically conductive material. 12. A connector according to claim 11 wherein said receiving means includes a barbed portion disposed where said band seals against said cable. 13. A connector according to claim 9, wherein said connector body, said first connection means, said second connection means, said fastening member, and said receiving means are all of metal. 14. A connector according to claim 13, wherein said receiving means includes a barbed portion disposed where said band seals against said cable. 15. A method of constructing a connector for a coaxial cable, comprising the steps of: providing a connector body; providing a fastening member for fastening said connector body to an object; providing a compression member; fitting an elastomeric band into a cavity formed at least in part by said compression member; inserting a prepared end of said cable through said compression member and said elastomeric band; and fitting said prepared cable end and said compression member to said connector body, wherein axial movement of said compression member onto said connector body causes said elastomeric band to deform and seal an outer layer of said cable to said connector to isolate an inside of said connector from environmental influences. 16. A method according to claim 15, wherein said connector body, said fastening member, and said compression member are of plastic. 17. A method according to claim 15, wherein said connector body, said fastening member, and said compression member are of metal. 18. A method according to claim 15, wherein said step of fitting said prepared cable end and said compression member to said connector body includes the step of fitting a ground sheath of said cable between said connector body and a metal post, and fitting a center conductor and dielectric portion of said cable inside said metal post. 19. A method according to claim 18, wherein said metal post includes a barbed portion disposed where said band seals against said cable. | FIELD OF THE INVENTION This invention relates generally to the field of cable connectors for CATV systems, and more particularly to a cable connector with an elastomeric band which seals the cable connector to a cable. BACKGROUND OF THE INVENTION A problem with cable connections exposed to the weather is that the connections are susceptible to moisture entering the connection whenever the cable connector is improperly or inadequately connected to the cable. Many attempts have been made to ensure that cable connections are sealed against moisture etc. from the environment. Many of the attempts require using a connector body made of two or more components in order to contain an adequate seal, thus increasing the complexity of the cable connector. SUMMARY OF THE INVENTION Briefly stated, a connector for a coaxial cable includes a connector body and a fastening member for connecting said connector to an object such as an equipment port. A post is fitted at least partially inside the connector body for receiving a prepared end of the cable. A compression member is fitted to a back of the connector body. An elastomeric band is fitted inside a cavity formed at least in part by the compression member. Axial movement of the compression member onto said connector body causes the elastomeric band to seal an outer layer of the cable to the connector to isolate the inside of the connector from environmental influences. According to an embodiment of the invention, a connector for a coaxial cable includes a connector body; a fastening member for connecting the connector to an object; a post fitted at least partially inside the connector body for receiving a prepared end of the cable; a compression member fitted to the connector body; and an elastomeric band fitted inside a cavity formed at least in part by the compression member; wherein axial movement of the compression member onto the connector body causes the elastomeric band to deform and seal an outer layer of the cable to the connector to isolate an inside of the connector from environmental influences. According to an embodiment of the invention, a connector for a coaxial cable includes a connector body; first connection means for connecting the connector to an object; and second connection means for connecting a prepared end of the cable to the connector; wherein the second connection means includes an elastomeric band for sealing an outer layer of the cable to the connector to isolate an inside of the connector from environmental influences. According to an embodiment of the invention, a method of constructing a connector for a coaxial cable includes the steps of providing a connector body; providing a fastening member for fastening the connector body to an object; providing a compression member; fitting an elastomeric band into a cavity formed at least in part by the compression member; inserting a prepared end of the cable through the compression member and the elastomeric band; and fitting the prepared cable end and the compression member to the connector body, wherein axial movement of the compression member onto the connector body causes the elastomeric band to deform and seal an outer layer of the cable to the connector to isolate an inside of the connector from environmental influences. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a partial cutaway perspective view of a connector according to an embodiment of the invention. FIG. 2 shows a perspective view of an embodiment of the invention, prior to installation, where the connector components are of plastic. FIG. 3 shows a perspective view of an embodiment of the invention, after installation, where the connector components are of plastic. FIG. 4 shows a partial cutaway perspective view of an embodiment of the invention where the connector components are of metal. FIG. 5 shows a perspective view of an embodiment of the invention, prior to installation, where the connector components are of metal. FIG. 6 shows a perspective view of an embodiment of the invention, after installation, where the connector components are of metal. FIG. 7 shows a partial cutaway perspective view of an embodiment of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a connector 5 includes a connector body 10 with a nut 12 on a front end 14 of body 10. Nut 12 is shown in this embodiment as a nut for connecting connector 5 to an F-port, but the type of connection is not an essential part of the present invention. A compression nut 16 is connected to body 10 at a back end 18 of body 10 via a plurality of threads 20 on compression nut 16 engaging a plurality of threads 22 on body 10. A post 24 is contained within connector 5. An elastomeric band 26 is disposed within a cavity 32 formed in part by a shoulder 34 of compression nut 16. “Band” is used in the sense of a flat strip, i.e., the width is greater than the thickness. (The “length” would be the circumference of the band, with the width being in the radial direction.) An O-ring is not considered a band and would not work as a replacement for the band of the present invention. Connector 5 is intended to be used with a conventional coaxial cable (not shown) which consists of an inner or center conductor surrounded by a dielectric material which in turn is surrounded by a braided ground return sheath. A cable jacket then surrounds the sheath. As a coaxial cable end (not shown) is inserted into back end 18 of connector 5, an end 28 of post 24 fits between the sheath and the dielectric, so that the dielectric and center conductor fit inside post 24, with the sheath and cable jacket between post 24 and connector body 10. In this embodiment, post 24 is of metal with connector body 10, nut 12, and compression nut 16 being of plastic. The electrical ground path thus goes from the cable sheath to post 24 to a ground portion (not shown) of the terminal that connector 5 is screwed into. Post 24 can also be of plastic when not needed to conduct an electrical path. Post 24 preferably includes a barbed portion 30, and as compression nut 16 is tightened onto body 10, elastomeric band 26 is forced to deform around the cable jacket, resulting in decreased length and increased thickness. In it's “open” position, i.e., when compression nut 16 is not tightened onto body 10, band 26 has enough clearance to allow the cable to pass through easily. By tightening compression nut 16 onto body 10, which applies a compressive force to elastomeric band 26, band 26 is squeezed inward onto the cable, thus creating a weather seal, as well as providing a great deal of normal force between elastomeric band 26 and the cable sheathing, thus providing retention force to the cable/connector combination. In addition to the tractive forces created by surface friction, the coaction of barbed portion 30 under the cable sheathing along with the inward pressure of elastomeric band 26 cause the cable sheath to conform closely to the profile of barbed portion 30, thus creating a mechanical interlock. This type of connector easily accommodates a broad range of cable diameters within a given cable family because of the flowable nature of elastomeric band 26 which conforms to the surface irregularities of the cable. Elastomers are also “sticky” which enables elastomeric band 26 to create a better seal than otherwise. Types of connectors with which elastomeric band 26 can be used include tool-compressed, standard compression styles, hand tightened styles, etc. In addition, elastomeric band 26 could be added to an existing connector design as a redundant means of sealing. Because the sealing and gripping are done by a small, contained element of the connector, the exterior of the connector can be made of whatever material suits a particular application. For instance, for outdoor applications the exterior of the connector can be entirely of brass for increased customer appeal, while a hand-tightened all plastic version with only a metal post 24 could easily be injection molded for the indoor consumer market. Outdoor versions of connector 5 can include a brass nut 12, a brass or stainless steel post 24, a brass or die-cast zinc body 10, and a brass or stainless steel compression nut 16. FIG. 2 shows a plastic version of the embodiment of FIG. 1 prior to installation, while FIG. 3 shows the embodiment of FIG. 2 after the embodiment has been installed on a cable (not shown). In the plastic version, all parts are preferably plastic except for post 24. A pair of reveals 13 permit easy thumb and finger access to a knurled portion 15 of plastic nut 12. Referring to FIG. 4, another embodiment of the present invention is shown. A connector 5′ includes a connector body 10′ with a nut 12′ on a front end 14′ of body 10′. Nut 12′ is shown in this embodiment as a nut for connecting connector 5′ to an F-port, but the type of connection is not an essential part of the present invention. A compression fitting 16′ is connected to body 10′ at a back end 18′ of body 10′ via a sleeve 21 on compression fitting 16′ engaging a portion 23 of body 10′. A post 24′ is contained within connector 5′. An elastomeric band 26 is disposed within a cavity 32′ formed in part by a shoulder 34′ of compression fitting 16′. As the coaxial cable end (not shown) is inserted into back end 18′ of connector 5′, an end 28′ of post 24′ fits between the cable sheath and the cable dielectric, so that the dielectric and center conductor fit inside post 24′, with the sheath and cable jacket between post 24′ and connector body 10′. Post 24′ preferably includes a barbed portion 30′, and as compression fitting 16′ is pushed onto body 10′, elastomeric band 26 is forced to deform around the cable jacket, resulting in decreased length and increased thickness. In it's “open” position, i.e., when compression fitting 16′ is not tightened onto body 10′, band 26 has enough clearance to allow the cable to pass through easily. By axial compression, band 26 is squeezed inward onto the cable, thus creating a weather seal, as well as providing a great deal of normal force between elastomeric band 26 and the cable sheathing, thus providing retention force to the cable/connector combination. In addition to the tractive forces created by surface friction, the coaction of barbed portion 30′ under the cable sheathing along with the inward pressure of elastomeric band 26 cause the cable sheath to conform closely to the profile of barbed portion 30′, thus creating a mechanical interlock. FIG. 5 shows an external view of a metal version of FIG. 4 prior to installation, while FIG. 6 shows the embodiment of FIG. 5 after the embodiment has been installed on a cable (not shown). The metal version, intended primarily for outdoor use, can have a brass nut 12′, a brass or stainless steel post 24′, a brass or diecast zinc body 10′, and a brass or stainless steel compression fitting 16′. Referring to FIG. 7, an embodiment is shown in which the elastomeric band of the present invention is used in addition to the seal already present in a cable connector. A cable connector 40 includes a connector body 42 to which a nut 44 is connected. Nut 44 attaches cable connector 40 to a piece of equipment or another connector. A post 48, extending inside body 42, is connected to both nut 44 and body 42. A driving member 50 overlaps a sealing portion 52 of body 42. A compression member 46 fits over both driving member 50 and a part of body 42. In normal operation, a prepared cable end (not shown) is inserted into connector 40 through a back end 56. When compression member is forced axially towards a front end of connector 40, driving member 50 forces sealing portion 52 radially against the cable, thus providing a seal against the outside environment. In this embodiment, an elastomeric band 54 fitted into a cavity 58 formed within compression member 46 and an end of driving member 50 provides extra sealing against the cable by axial compression. When band 54 is squeezed inward onto the cable, it creates a weather seal, as well as a great deal of normal force between elastomeric band 54 and the cable sheathing, thus providing retention force to the cable/connector combination. Examples of elastomers include any thermoplastic elastomer (TPE), silicone rubber, or urethane. The key properties are resilience, resistance to creep, resistance to compression set, and the creation of a good grip with the cable jacket. The length of band 26, i.e., in the axial direction of connector 5, can be equal to the length of the cavity in which it is seated. The important consideration is that any pre-compression done to band 26 must not affect insertion of the cable end, i.e., the thickness of elastomeric ring 26 cannot become so large during pre-compression as to impede insertion of the cable end. While the present invention has been described with reference to a particular preferred embodiment and the accompanying drawings, it will be understood by those skilled in the art that the invention is not limited to the preferred embodiment and that various modifications and the like could be made thereto without departing from the scope of the invention as defined in the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>A problem with cable connections exposed to the weather is that the connections are susceptible to moisture entering the connection whenever the cable connector is improperly or inadequately connected to the cable. Many attempts have been made to ensure that cable connections are sealed against moisture etc. from the environment. Many of the attempts require using a connector body made of two or more components in order to contain an adequate seal, thus increasing the complexity of the cable connector. | <SOH> SUMMARY OF THE INVENTION <EOH>Briefly stated, a connector for a coaxial cable includes a connector body and a fastening member for connecting said connector to an object such as an equipment port. A post is fitted at least partially inside the connector body for receiving a prepared end of the cable. A compression member is fitted to a back of the connector body. An elastomeric band is fitted inside a cavity formed at least in part by the compression member. Axial movement of the compression member onto said connector body causes the elastomeric band to seal an outer layer of the cable to the connector to isolate the inside of the connector from environmental influences. According to an embodiment of the invention, a connector for a coaxial cable includes a connector body; a fastening member for connecting the connector to an object; a post fitted at least partially inside the connector body for receiving a prepared end of the cable; a compression member fitted to the connector body; and an elastomeric band fitted inside a cavity formed at least in part by the compression member; wherein axial movement of the compression member onto the connector body causes the elastomeric band to deform and seal an outer layer of the cable to the connector to isolate an inside of the connector from environmental influences. According to an embodiment of the invention, a connector for a coaxial cable includes a connector body; first connection means for connecting the connector to an object; and second connection means for connecting a prepared end of the cable to the connector; wherein the second connection means includes an elastomeric band for sealing an outer layer of the cable to the connector to isolate an inside of the connector from environmental influences. According to an embodiment of the invention, a method of constructing a connector for a coaxial cable includes the steps of providing a connector body; providing a fastening member for fastening the connector body to an object; providing a compression member; fitting an elastomeric band into a cavity formed at least in part by the compression member; inserting a prepared end of the cable through the compression member and the elastomeric band; and fitting the prepared cable end and the compression member to the connector body, wherein axial movement of the compression member onto the connector body causes the elastomeric band to deform and seal an outer layer of the cable to the connector to isolate an inside of the connector from environmental influences. | 20040218 | 20061010 | 20050818 | 58950.0 | 4 | DINH, PHUONG K | CABLE CONNECTOR WITH ELASTOMERIC BAND | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,781,766 | ACCEPTED | Gallium nitride based light emitting device and the fabricating method for the same | A GaN-based light-emitting device and the fabricating method for the same are described. The light-emitting device is a light-emitting body with a light extraction layer thereon. The light-emitting body has some GaN-based layers and is capable of emitting a light when energy is applied. The light extraction layer is a double layered structure having a current spreading layer and a micro-structure layer, or a single layered structure without the current spreading layer. The micro-structure layer is a TiN layer with a nano-net structure obtained by nitridation of a Ti layer or a Pt layer with metal clusters thereon obtained by annealing of a Pt layer. | 1. A gallium nitride (GaN) based light-emitting device (LED), comprising: a light-emitting body comprising a GaN-based material capable of emitting a light; a light extraction layer comprising: a current spreading layer disposed over said light-emitting body; and a micro-structure layer disposed over said current spreading layer, wherein the micro-structure is a TiN layer having a nano-net structure. 2. The LED according to claim 1, wherein said light-emitting body comprises an n-type GaN-based layer, a semiconductor active layer and a p-type GaN-based layer and said semiconductor active layer is disposed over said n-type GaN-based layer and said p-GaN-based layer is disposed over said active layer. 3. The LED according to claim 1, wherein said light-emitting body has a p-type electrode and an n-type electrode and said p-type electrode is disposed over said micro-structure layer. 4. The LED according to claim 3, wherein said p-type electrode is disposed beside said micro-structure layer and said current spreading layer. 5. The LED according to claim 1, wherein said current spreading layer is a transparent and conductive layer and selected from a group consisting of a Ni/Au double layer structure, Ni, Pt, Pd, Rh, Ru, Os, Ir, Zn, In, Sn, Mg and an oxide thereof. 6. The LED according to claim 1, wherein said TiN nano-net is formed by nitridating a Ti layer. 7. A gallium nitride (GaN) based light-emitting device (LED), comprising: a light-emitting body comprising a GaN-based material capable of emitting a light; and a light extraction layer comprising: a current spreading layer disposed over said light-emitting body; and a micro-structure layer disposed over said current spreading layer and being a Pt layer having metal clusters. 8. The LED according to claim 7, wherein said light-emitting body comprises an n-type GaN-based layer, a semiconductor active layer and a p-type GaN-based layer and said semiconductor active layer is disposed over said n-type GaN-based layer and said p-GaN-based layer is disposed over said active layer. 9. The LED according to claims 7 and 8, wherein said light-emitting body has a p-type electrode and an n-type electrode and said p-type electrode is disposed over said micro-structure layer. 10. The LED according to claim 9, wherein said p-type electrode is disposed beside said micro-structure layer and said current spreading layer. 11. The LED according to claim 6, wherein said current spreading layer is a transparent and conductive layer and selected from a group consisting of a Ni/Au double layer structure, Ni, Pt, Pd, Rh, Ru, Os, Ir, Zn, In, Sn, Mg and an oxide thereof. 12. The LED according to claim 7, wherein said Pt layer having metal clusters is formed by annealing a Pt layer. 13. A method of manufacturing a gallium nitride (GaN) based light-emitting device (LED), comprising the steps of: preparing a substrate; forming an n-type GaN-based layer over said substrate; forming a semiconductor active layer over said n-type GaN-based layer; forming a p-type GaN-based layer over said semiconductor active layer; forming a current spreading layer over said p-GaN-based layer; and forming a micro-net layer over said current spreading layer. 14. The method according to claim 13, further comprising a step of forming a p-type electrode and an n-type electrode over said LED after said step of forming said micro-net layer and wherein said p-type electrode is formed over said micro-net structure or beside said micro-structure layer and said current spreading layer. 15. The method according to claim 13, wherein said current spreading layer is a transparent and conductive layer and selected from a group consisting of a Ni/Au double layer structure, Ni, Pt, Pd, Rh, Ru, Os, Ir, Zn, In, Sn, Mg and an oxide thereof. 16. The method according to claim 13, wherein said step of forming a micro-structure layer further comprises a step of forming a Ti layer over said p-type GaN-based layer and then nitridating said Ti layer. 17. The method according to claim 13, wherein said step of forming a micro-structure layer further comprises a step of forming a Pt layer over said p-type GaN-based layer and then annealing said Pt layer. 18. A gallium nitride (GaN) based light-emitting device (LED), comprising: a light-emitting body comprising a GaN-based material and capable of emitting a light; a GaN-based p+/n+ tunneling junction layer disposed over said light-emitting body; a light extraction layer disposed over said p+/n+tunneling junction layer, the light extraction layer being a TiN layer having a nano-net structure or a Pt layer having metal clusters. 19. The LED according to claim 18, wherein said light-emitting body comprises an n-type GaN-based layer, a semiconductor active layer and a p-type GaN-based layer, said semiconductor active layer is disposed over said n-type GaN-based layer and said p-GaN-based layer is disposed over said active layer. 20. The LED according to claim 18, wherein said light-emitting body has a p-type electrode and an n-type electrode and said p-type electrode is disposed over a micro-structure layer. 21. The LED according to claim 18, wherein said TiN having said nano-net structure is formed by nitridating a Ti layer and said Pt having said metal clusters is formed by annealing a Pt layer. 22. The LED according to claim 18, wherein said light extraction layer further comprises a current spreading layer and said current spreading layer is a transparent and conductive layer and selected from a group consisting of a Ni/Au double layer structure, Ni, Pt, Pd, Rh, Ru, Os, Ir, Zn, In, Sn, Mg and an oxide thereof. 23. A gallium nitride (GaN) based light-emitting device (LED), comprising: a conductive metal substrate; a conductive metal reflector disposed over said substrate; a p-type GaN-based layer disposed over said metal reflector; a semiconductor active layer disposed over said p-type GaN-based layer; an n-type GaN-based layer disposed over said semiconductor active layer; and a micro-structure layer disposed over said n-type GaN-based layer, the micro-structure layer being a TiN layer having a nano-net structure or a Pt layer having metal clusters. 24. The LED according to claim 23, wherein a p-type metal is disposed below said conductive metal substrate and an n-type substrate is disposed over said micro-structure layer. 25. The LED according to claim 23, wherein said TiN having said nano-net structure is formed by nitridating a Ti layer and said Pt having said metal clusters is formed by annealing a Pt layer. | BACKGROUND OF THE INVENTION 1. Field of Invention The present invention is related to an improvement of luminous efficiency of a gallium nitride (GaN) based light-emitting diode (LED). in particular, the present invention is related to a GaN LED with a metal micro-structure as a light extraction layer and a manufacturing method for the same. 2. Related Art Semiconductor light-emitting diodes (LEDs) have been developed for several decades and the luminous efficiency thereof plays a key role in whether LEDs may be further applied in lighting facilities generally used in ordinary living. Therefore, LED research, for the past decades, has been focused on improvement of luminous efficiency. Generally, luminous efficiency varies with the following factors: semiconductor material adopted, device structure devised, transparency of material used, total reflection existed, etc. Of the semiconductor LEDs, a gallium nitride (GaN) based material may be the most commonly used. To let the GaN-based material irradiate light, a voltage or a current has to be applied to the corresponding LED. To apply a voltage or a current to the LED, a pair of positive and negative electrodes are disposed on the LED structure. The positive electrode is also called a p-electrode while the negative electrode is also called an n-electrode, since charges provided by the p-electrode first flow into a p-type semiconductor material layer and charges supplied by the n-electrode first flow into an n-type semiconductor material layer. The p-type electrode is where positive charges flow into the LED structure, and holes are carriers for conductivity. On the other hand, the n-type electrode is where negative charges flow into the LED structure, and electrons are carriers for conductivity. Owing to the poorer mobility of the hole carriers as compared to the electron carriers, a current spreading layer is generally disposed under the p-type electrode so that the hole carriers may be uniformly distributed in the p-type semiconductor layer. In this case, electric force lines between the p-type electrode and the n-type electrode may also be uniformly distributed so as to enhance excitation of light in the LED. The afore-mentioned current spreading layer may be any suitable material, and a Ni/Au double layered structure is the most commonly used. Referring to FIG. 1, which illustrates an LED structure 10, the LED structure 10 comprises a substrate 11, a buffer layer 12, an n-type GaN-based layer 13, a semiconductor active layer 14, a p-type GaN-based layer 15, a p-type semiconductor layer 16, a current spreading layer 17 and a p-type electrode 18. The process thereof may be found in ROC patents 558848, 419837, etc. In the figure, the current spreading layer 17 is disposed between the p-type semiconductor layer 16 and the p-electrode 18 and used to distribute uniformly positive charges thereon and then enter into the p-type semiconductor layer 16. However, a serious total reflection issue is closely related to the current spreading layer since the current spreading layer has flat surface and thus reflects light back to the LED structure and has a poor light extraction. Some technologies for roughening the current spreading layer are provided. For example, roughening structures are disposed where the emitted light is output so that most emission angles of the emitted lights are smaller than a critical angle, which is defined by Snell's Law. These roughening structures are generally shaped as hemispheres or truncated pyramids. However, these roughening shapes are hard to form and may be expensive. Other roughening technologies are available. For example, an etch process is applied onto the upper flat surface of the LED to form small, roughened facets on the flat surface so that most emission angles of emitted light may output without reflection to the LED structure. Such a roughening method comprises a process of randomly etching a surface. For example, particles are deposited on the surface and then used as masks in the random etching. However, there are at least two major disadvantages. First of all, some small islands may exist in the p-type electrode. Since the lower parts of the island structures do not contact the p-type electrode contact, no light will be emitted by these portions and the total light output is reduced. Second, since the upper surface of the LED structure is very close to the light-generating area below, the light generating area may be very likely broken. In view of the disadvantages of the prior GaN-based LED, there is a need to provide a GaN-based LED with high light extraction efficiency. SUMMARY OF THE INVENTION The present invention is aimed to provide a GaN-based LED with high light extraction efficiency and a method for manufacturing the GaN-based LED. In view of the purpose above, a micro-structure surface is formed on a current spreading layer of the GaN-based LED structure according to the present invention. With the micro-structure, a total reflection of light associated with the current spreading layer is reduced and the corresponding luminous efficiency is improved. The LED structure with the micro-structure according to the present invention has two primary embodiments. In the first embodiment, a TiN layer is formed on the current spreading layer and the two layers jointly form a light extraction double layered structure. The double structure is disposed on a light-emitting body. The TiN layer has a micro-structure and the micro-structure is a nano-net structure. With the nano-net structure, lights generated by an active layer in the light-emitting body are more immune to total reflection. In the first manufacturing embodiment according to the present invention, a GaN-based light-emitting body is first formed, a current spreading layer is next formed on the light-emitting body, and a Ti layer is formed on the current spreading layer. Next, the Ti layer is subjected to nitridation so that a TiN micro-structure surface with a nano-net structure is formed. In the second manufacturing embodiment according to the present invention, a GaN-based light-emitting body is first formed, a current spreading layer is next formed on the light-emitting body, and a Pt layer is formed on the current spreading layer. Next, the Pt layer is annealed so that a Pt micro-structure surface with metal clusters is formed. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become more fully understood from the detailed description given hereinbelow for illustration only, and thus are not limitative of the present invention, and wherein: FIG. 1 is a front view of a prior gallium nitride (GaN) based light emitting diode (LED); FIG. 2 is an illustration of a first device structure embodiment according to the present invention; FIG. 3 is an illustration of a first device structure embodiment according to the present invention; FIG. 4 is a first manufacturing method embodiment according to the present invention used to manufacture the first device structure according to the present invention; FIG. 5 is a second manufacturing method embodiment according to the present invention used to manufacture the second device structure according to the present invention; FIG. 6 is an illustration of an alternative LED with a micro-structure layer used according to the present invention; FIG. 7 is an illustration of a tunneling junction LED with the micro-structure layer used according to the present invention; and FIG. 8 an illustration of a vertical LED with the micro-structure layer used according to the present invention. DETAILED DESCRIPTION OF THE INVENTION The present invention provides a light extraction layer with a micro-structure surface to reduce total reflection of light and enhance a light extraction efficiency of the light extraction layer, which is illustrated below. The gallium nitride (GaN) light-emitting device (LED) primarily comprises two major embodiments. Referring to FIG. 2, which illustrates a first device structure 20 embodiment according to the present invention, a substrate 21 is first prepared, which may be sapphire, GaN or SiC or other suitable materials. An n-type GaN-based layer 23, a semiconductor active layer 24 and a p-type GaN-based layer 25 are sequentially formed over the substrate 21 to generate light when a voltage or a current is applied. The three layers 23, 24, 25 comprise a light-emitting body. The semiconductor active layer may be an AlGaNInN layer or an InGaN/GaN layer. The substrate 21 and the n-type GaN-based layer 23 may be selectively disposed on a buffer layer 22 to let the two layers 21, 23 adjacent to the buffer layer 22 have better lattice matching. A p-type contact layer 26 and a light extract layer 27 are sequentially disposed over the contact layer 26. The contact layer 26 may be p-InGaN or p-AlInGaN layer and the light extraction layer 27 is a double layer structure composed of a current spreading layer 28 and a micro-structure layer 29. The current spreading layer 28 is made of transparent and conductive material and is at least a Ni/Au double layered structure, Ni, Pt, Pd, Rh, Ru, Os, Ir, Zn, In, Sn, Mg or oxides thereof, which may be blended with additives to increase conductivity thereof, such as aluminum. The transparent wavelength of the current spreading layer 28 depends on the light-emitting body used, so the lights generated by the light-emitting body may largely penetrate the current spreading layer 28. In FIG. 2, the micro-structure layer 29 is a TiN layer with a nano-net structure and is not shown for clarity. Since the TiN nano-net structure includes considerably fine roughening structures, more photons generated by the semiconductor active layer 24 are output with emission angles smaller than a critical angle. As compared to the prior roughening structure, the micro-structure is much smaller, and hence the total reflection may be greatly reduced. Further, a p-type electrode 40 is disposed on the micro-structure 29 and an n-type electrode 32 on the n-type GaN-based layer for supplying a current into the light-emitting body. Referring to FIG. 3, which shows a second device embodiment according to the present invention, the device 40 comprises a substrate 41, a buffer layer 42, an n-type GaN-based layer 43, a semiconductor active layer 44, a p-type GaN-based layer 45, a p-type contact layer 46, a current spreading layer 48, a micro-structure layer 49 and electrodes 50, 51. The second device embodiment is the same as the first device embodiment except for the micro-structure layer 49 of the light extraction layer 47. In the embodiment, the micro-structure 49 is an annealed Pt layer with metal clusters, which is not shown for clarity. Similarly, since the dimension of the metal clusters is much smaller than that of the prior roughening structure, the number of photons emitted with an emission angle smaller than the critical angle increases greatly. Therefore, the light extraction efficiency may be considerably enhanced. Referring to FIG. 4, which illustrates a first manufacturing embodiment for the first device according to the present invention, a substrate is first prepared (61). Next, a buffer layer is selectively formed over the substrate (62) by a molecular beam epitaxial (MBE) method, metal organic chemical vapor deposition (MOCVD) or other suitable technologies. Next, an n-type GaN-based layer is formed over the buffer layer (63), and a semiconductor active layer is formed over the n-type GaN-based layer 66. Next, a current spreading layer is formed over the contact layer (67) and a Ti layer is formed over the current spreading layer (68). Next, the Ti layer is subjected to nitridation to form a TiN layer with a micro-structure (69). In addition, the micro-structure layer may be formed with a p-type electrode thereon and an n-type electrode may be formed over a portion of the n-type GaN-based layer. Reference is made to FIG. 5, which shows a second manufacturing method embodiment for the second device according to the present invention. In the second manufacturing method, Step 71 to Step 77 is the same as Step 61 to Step 67 in FIG. 4. After Step 77, in which a current spreading layer is formed, a Pt layer is then formed over the current spreading layer (78). Then, the Pt layer is annealed to have a metal cluster formed thereon (79). In addition, a p-type electrode may be formed over the micro-structure layer and an n-type electrode may be formed over a portion of the n-type GaN-based layer. FIG. 6 illustrates a light-emitting device structure 80 where a p-type metal electrode is disposed beside a current spreading layer 86 but not over the current spreading layer 86. The device structure 80 comprises a substrate 81, an n-type GaN-based layer 82, a semiconductor active layer 83, a p-type GaN-based layer 84, a p-type contact layer 85, a GaN-based current spreading layer 86 formed over the p-type contact layer 85, and a p-type metal electrode 88 disposed beside the GaN-based current spreading layer 86. In addition, an inventive micro-structure layer 87 is finally disposed on the GaN-based current spreading layer 86 and beside the metal electrode 88. In the device structure embodiment, since the micro-structure 87 is not involved with current spreading, the micro-structure 87 may be separately formed with the p-type metal electrode 88. The inventive micro-structure with the above nano-net structure or metal clusters may be used in a tunneling junction structure 90, which is described in FIG. 7. In the figure, the structure 90 comprises a substrate 91, an n-type GaN-based layer 92, a semiconductor 93, p-type GaN-based layer 94 and a p+ and an n+-type GaN-based layer 95, 96. The p+-type GaN-based layer is disposed over the n+-type GaN-based layer 96 and the two layers 95, 96 will be referred to as a p+/n+-type GaN-based layer. Then, the inventive micro-structure 97 is directly disposed over the GaN-based layer 96 without need of the current spreading layer in the foregoing embodiments since the GaN-based layer 96 has electrons as its major carriers. However, a current spreading layer may also be selectively included in the structure 90. Finally, a p-type electrode is disposed on the micro-net structure 97 and an n-type electrode on the n-type GaN-based layer 92. Referring to FIG. 8, the micro-structure layer according to the present invention is used in a vertical LED structure 100. In the figure, a metal reflective layer 102 is disposed over a substrate 101 to restrict the light generated by the p-type GaN-based layer 103, the semiconductor active layer 104 and the n-type GaN-based layer 105 above the metal reflective layer 102. The substrate 101 is a conductive metallic material used to supply charges to the p-type GaN-based layer 103 since the n-type electrode 107 is disposed on the most upper part of the structure 100. In such a structure, since no low mobility issue of holes exists, no current spreading layer is required. A current spreading layer may be selectively incorporated. Therefore, the inventive micro-structure layer 106 may be formed directly over the n-type GaN-based layer 105. Then an n-type electrode 107 is disposed on the micro-structure layer 106. In addition to the advantage of reduction of total reflection and improvement of light extraction efficiency, the manufacturing of the device structure of the present invention is not complicated and thus the light extraction layer of the present invention is suitable for use in any type of light emitting device. The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of Invention The present invention is related to an improvement of luminous efficiency of a gallium nitride (GaN) based light-emitting diode (LED). in particular, the present invention is related to a GaN LED with a metal micro-structure as a light extraction layer and a manufacturing method for the same. 2. Related Art Semiconductor light-emitting diodes (LEDs) have been developed for several decades and the luminous efficiency thereof plays a key role in whether LEDs may be further applied in lighting facilities generally used in ordinary living. Therefore, LED research, for the past decades, has been focused on improvement of luminous efficiency. Generally, luminous efficiency varies with the following factors: semiconductor material adopted, device structure devised, transparency of material used, total reflection existed, etc. Of the semiconductor LEDs, a gallium nitride (GaN) based material may be the most commonly used. To let the GaN-based material irradiate light, a voltage or a current has to be applied to the corresponding LED. To apply a voltage or a current to the LED, a pair of positive and negative electrodes are disposed on the LED structure. The positive electrode is also called a p-electrode while the negative electrode is also called an n-electrode, since charges provided by the p-electrode first flow into a p-type semiconductor material layer and charges supplied by the n-electrode first flow into an n-type semiconductor material layer. The p-type electrode is where positive charges flow into the LED structure, and holes are carriers for conductivity. On the other hand, the n-type electrode is where negative charges flow into the LED structure, and electrons are carriers for conductivity. Owing to the poorer mobility of the hole carriers as compared to the electron carriers, a current spreading layer is generally disposed under the p-type electrode so that the hole carriers may be uniformly distributed in the p-type semiconductor layer. In this case, electric force lines between the p-type electrode and the n-type electrode may also be uniformly distributed so as to enhance excitation of light in the LED. The afore-mentioned current spreading layer may be any suitable material, and a Ni/Au double layered structure is the most commonly used. Referring to FIG. 1 , which illustrates an LED structure 10 , the LED structure 10 comprises a substrate 11 , a buffer layer 12 , an n-type GaN-based layer 13 , a semiconductor active layer 14 , a p-type GaN-based layer 15 , a p-type semiconductor layer 16 , a current spreading layer 17 and a p-type electrode 18 . The process thereof may be found in ROC patents 558848, 419837, etc. In the figure, the current spreading layer 17 is disposed between the p-type semiconductor layer 16 and the p-electrode 18 and used to distribute uniformly positive charges thereon and then enter into the p-type semiconductor layer 16 . However, a serious total reflection issue is closely related to the current spreading layer since the current spreading layer has flat surface and thus reflects light back to the LED structure and has a poor light extraction. Some technologies for roughening the current spreading layer are provided. For example, roughening structures are disposed where the emitted light is output so that most emission angles of the emitted lights are smaller than a critical angle, which is defined by Snell's Law. These roughening structures are generally shaped as hemispheres or truncated pyramids. However, these roughening shapes are hard to form and may be expensive. Other roughening technologies are available. For example, an etch process is applied onto the upper flat surface of the LED to form small, roughened facets on the flat surface so that most emission angles of emitted light may output without reflection to the LED structure. Such a roughening method comprises a process of randomly etching a surface. For example, particles are deposited on the surface and then used as masks in the random etching. However, there are at least two major disadvantages. First of all, some small islands may exist in the p-type electrode. Since the lower parts of the island structures do not contact the p-type electrode contact, no light will be emitted by these portions and the total light output is reduced. Second, since the upper surface of the LED structure is very close to the light-generating area below, the light generating area may be very likely broken. In view of the disadvantages of the prior GaN-based LED, there is a need to provide a GaN-based LED with high light extraction efficiency. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention is aimed to provide a GaN-based LED with high light extraction efficiency and a method for manufacturing the GaN-based LED. In view of the purpose above, a micro-structure surface is formed on a current spreading layer of the GaN-based LED structure according to the present invention. With the micro-structure, a total reflection of light associated with the current spreading layer is reduced and the corresponding luminous efficiency is improved. The LED structure with the micro-structure according to the present invention has two primary embodiments. In the first embodiment, a TiN layer is formed on the current spreading layer and the two layers jointly form a light extraction double layered structure. The double structure is disposed on a light-emitting body. The TiN layer has a micro-structure and the micro-structure is a nano-net structure. With the nano-net structure, lights generated by an active layer in the light-emitting body are more immune to total reflection. In the first manufacturing embodiment according to the present invention, a GaN-based light-emitting body is first formed, a current spreading layer is next formed on the light-emitting body, and a Ti layer is formed on the current spreading layer. Next, the Ti layer is subjected to nitridation so that a TiN micro-structure surface with a nano-net structure is formed. In the second manufacturing embodiment according to the present invention, a GaN-based light-emitting body is first formed, a current spreading layer is next formed on the light-emitting body, and a Pt layer is formed on the current spreading layer. Next, the Pt layer is annealed so that a Pt micro-structure surface with metal clusters is formed. | 20040220 | 20061010 | 20051201 | 93491.0 | 0 | NGUYEN, CUONG QUANG | GALLIUM NITRIDE BASED LIGHT EMITTING DEVICE AND THE FABRICATING METHOD FOR THE SAME | SMALL | 0 | ACCEPTED | 2,004 |
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10,781,791 | ACCEPTED | Piezoelectric element and touch screen utilizing the same | A piezoelectric element includes a substrate, a lower electrode on the substrate, a piezoelectric layer on the lower electrode, and an upper electrode on the piezoelectric layer. The upper electrode includes a common base and a plurality of parallel branches extending from the base. The branches are arranged at a regular interval or pitch λ1. The lower electrode faces the branches of the upper electrode via the piezoelectric layer. The thickness h of the piezoelectric layer and the branch pitch λ1 are determined to satisfy an inequality 0.005≦h/λ1≦0.1. The lower electrode has a hillock occurrence rate which is no greater than 0.1%. | 1. A piezoelectric element comprising: a substrate; a piezoelectric layer having a first surface and a second surface opposite to the first surface, the first surface facing the substrate, the piezoelectric layer having a thickness h; a first electrode arranged between the substrate and the first surface of the piezoelectric layer; and a second electrode held in contact with the second surface of the piezoelectric layer; wherein one of the first electrode and the second electrode includes a common base and a plurality of parallel branches extending from the base, the branches being spaced from each other by a pitch λ, the other of the first electrode and the second electrode including a portion that faces the branches via the piezoelectric layer, wherein the thickness h and the pitch λ are determined to satisfy an inequality 0.005≦h/λ≦0.1, wherein the first electrode has a hillock occurrence rate which is no greater than 0.1%. 2. The piezoelectric element according to claim 1, wherein the common base and the branches belong to the first electrode. 3. The piezoelectric element according to claim 1, wherein the first electrode is formed of an aluminum alloy containing 0.1˜3.0 wt % of a metal selected from a group consisting of Ti, Cr, Ni, Cu, Zn, Pd, Ag, Hf, W, Pt and Au. 4. The piezoelectric element according to claim 3, wherein the piezoelectric layer is formed of ZnO doped with Mn. 5. A touch screen comprising: a substrate including a detection region and a marginal region surrounding the detection region; a wave generator arranged in the marginal region for generating a surface acoustic wave in the substrate; and a wave receiver arranged in the marginal region for receiving the surface acoustic wave; each of the wave generator and the wave receiver comprising: a piezoelectric layer having a first surface facing the substrate and a second surface opposite to the first surface, the piezoelectric layer having a thickness h; a first electrode arranged between the substrate and the first surface of the piezoelectric layer; and a second electrode held in contact with the second surface of the piezoelectric layer; wherein one of the first electrode and the second electrode includes a common base and a plurality of parallel branches extending from the base, the branches being spaced from each other by a pitch λ, the other of the first electrode and the second electrode including a portion that faces the branches via the piezoelectric layer, wherein the thickness h and the pitch λ are determined to satisfy an inequality 0.005≦h/λ≦0.1, wherein the first electrode has a hillock occurrence rate which is no greater than 0.1%. 6. The touch screen according to claim 5, wherein the common base and the branches belong to the first electrode. 7. The touch screen according to claim 5, wherein the first electrode is formed of an aluminum alloy containing 0.1˜3.0 wt % of a metal selected from a group consisting of Ti, Cr, Ni, Cu, Zn, Pd, Ag, Hf, W, Pt and Au. 8. The touch screen according to claim 7, wherein the piezoelectric layer is formed of ZnO doped with Mn. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric element to generate or receive surface acoustic waves. The present invention also relates to a SAW touch screen incorporating piezoelectric elements used as a wave generator or receiver. 2. Description of the Related Art Touch screens or touch panels are used as data input units to enable users to interact with a computer system for e.g. factory automation equipment, office automation equipment or automatic measuring device. As known, a touch screen is a force-sensitive device designed to detect an area on the screen that the user touches with his or her finger, for example. The computer system performs required data processing based on the information of a location detected by the touch screen and other necessary data. Recently, attention has been drawn to “SAW” touch screens in which the touched area is detected based on the surface acoustic wave (SAW). A typical SAW touch screen includes a transparent substrate that has a detection region and a marginal region surrounding the detection region. The marginal region is provided with a plurality of piezoelectric elements as a wave generator or wave receiver. Examples of SAW touch screens are disclosed in Japanese patent application laid-open Nos. H06-149459 and H10-55240. A conventional piezoelectric element used as a wave generator or receiver is constituted by an interdigitated transducer (IDT) patterned on the marginal region for each element and a piezoelectric layer formed on the marginal region to cover the IDT. The IDT consists of a pair of comb-like conductors each having a prescribed number of parallel electrode fingers (conductive branches). The electrode fingers of one comb-like conductor are arranged alternately with and parallel to those of the other comb-like conductor. The piezoelectric layer is formed of a piezoelectric material, which exhibits the piezoelectric effect (generation of electric polarization as a result of the application of mechanical stress) and the reverse piezoelectric effect (production of a mechanical distortion as a result of the application of a voltage). Upon application of an alternating voltage to the IDT of a piezoelectric element, an electric field is generated between adjacent electrode fingers. As a result, mechanical distortions occur in the piezoelectric layer due to the reverse piezoelectric effect, thereby producing elastic waves in the piezoelectric layer. In this process, the most strongly excited wave is a wave whose wavelength is equal to the pitch of the electrode fingers of the IDT. The produced elastic waves propagate along the surface of the substrate, to reach the wave-receiving piezoelectric elements. At these wave receivers, alternating electric fields are generated between the electrode fingers of the IDT due to the piezoelectric effect in the piezoelectric layer. Accordingly, an electromotive force is produced, and an alternating current is outputted from the IDT. In operation of the SAW touch screen, the wave-generating piezoelectric elements produce surface acoustic waves. The surface acoustic waves propagate through the detection region of the substrate, to be received by particular piezoelectric elements serving as the wave receivers. When a finger is held in contact with an area in the detection region, the amplitude of the surface acoustic-wave decreases as the wave passes through the contact point. The damping of the wave is detected and analyzed to locate the contact point in the detection region. In a SAW touch screen, the electromechanical conversion rate of the piezoelectric elements should be as high as possible for attaining reduction of the driving voltage and for improving the detection accuracy. Specifically, with a high electromechanical conversion rate, each piezoelectric element can generate elastic waves efficiently in response to the applied voltage (when used as a wave generator), or can output an alternating current efficiently in response to the received elastic wave (when used as a wave receiver). In such a situation, the insertion loss between input and output signals for piezoelectric elements is small, whereby the reduction of driving voltage and the improvement of detection accuracy are realized. In the conventional SAW touch screens, however, the piezoelectric elements do not have a sufficiently high electro-mechanical conversion rate for attaining a desired reduction of the driving voltage and improvement of the detection accuracy. SUMMARY OF THE INVENTION The present invention has been proposed under the circumstances described above. It is, therefore, an object of the present invention to provide a piezoelectric element having a higher electromechanical conversion rate than the conventional elements. Another object of the present invention is to provide a SAW touch screen incorporating such a piezoelectric element for use as a wave generator or wave receiver. According to a first aspect of the present invention, there is provided a piezoelectric element comprising: a substrate; a piezoelectric layer having a first surface and a second surface opposite to the first surface, the first surface facing the substrate, the piezoelectric layer having a thickness h; a first electrode arranged between the substrate and the first surface of the piezoelectric layer; and a second electrode held in contact with the second surface of the piezoelectric layer. One of the first electrode and the second electrode includes a common base and a plurality of parallel branches extending from the base and spaced from each other by a prescribed pitch λ. The other of the first electrode and the second electrode includes a portion that faces the branches via the piezoelectric layer. The thickness h of the piezoelectric layer and the branch pitch λ are determined to satisfy an inequality 0.005≦h/λ≦0.1. In addition, the first electrode has a hillock occurrence rate which is no greater than 0.1%. The above-formulated setting of the thickness h and the pitch λ is advantageous for providing a high electro-mechanical conversion rate in the piezoelectric element. In the prior art devices, however, a sufficiently high electro-mechanical conversion rate fails to be obtained as the thickness h of the piezoelectric layer is made smaller, even if the above relation 0.005≦h/λ≦0.1 is observed. In light of this, according to the present invention, the hillock occurrence rate of the first electrode is no greater than 0.1%. The inventors have found that such a low hillock occurrence rate ensures a required high electromechanical conversion rate even when the thickness h of the piezoelectric layer is very small (on the order of micrometers, for example). The definition of the hillock occurrence rate is found in DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS below. Preferably, the common base and the branches may belong to the first electrode. Preferably, the first electrode may be formed of an aluminum alloy containing 0.1˜3.0 wt % of a metal selected from a group consisting of Ti, Cr, Ni, Cu, Zn, Pd, Ag, Hf, W, Pt and Au. This arrangement serves to make the hillock occurrence rate of the first electrode equal to or lower than 0.1%. This is because the aluminum alloy has a smaller coefficient of thermal expansion than pure aluminum. Preferably, the piezoelectric layer may be formed of ZnO doped with Mn. This arrangement is advantageous for preventing e.g. Al contained in the first electrode from diffusing into the piezoelectric layer. As a result, the piezoelectric element can maintain the high electro-mechanical conversion rate. According to a second aspect of the present invention, there is provided a touch screen comprising: a substrate including a detection region and a marginal region surrounding the detection region; a wave generator arranged in the marginal region for generating a surface acoustic wave in the substrate; and a wave receiver arranged in the marginal region for receiving the surface acoustic wave. Further, each of the wave generator and the wave receiver comprises: a piezoelectric layer having a first surface facing the substrate and a second surface opposite to the first surface, the piezoelectric layer having a thickness h; a first electrode arranged between the substrate and the first surface of the piezoelectric layer; and a second electrode held in contact with the second surface of the piezoelectric layer. One of the first electrode and the second electrode includes a common base and a plurality of parallel branches extending from the base, the branches being spaced from each other by a pitch λ. The other of the first electrode and the second electrode includes a portion that faces the branches via the piezoelectric layer. As in the piezoelectric element of the first aspect, the thickness h and the pitch λ are determined to satisfy an inequality 0.005≦h/λ≦0.1, and the first electrode has a hillock occurrence rate which is no greater than 0.1%. Preferably, the common base and the branches may belong to the first electrode. The first electrode may be formed of an aluminum alloy containing 0.1˜3.0 wt % of a metal selected from a group consisting of Ti, Cr, Ni, Cu, Zn, Pd, Ag, Hf, W, Pt and Au. The piezoelectric layer may be formed of ZnO doped with Mn. Other features and advantages of the present invention will become apparent from the detailed description given below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing a piezoelectric element according to a first embodiment of the present invention; FIG. 2 is a sectional view taken along lines II-II in FIG. 1; FIG. 3 is an enlarged sectional view illustrating hillocks formed in the lower electrode on the substrate; FIGS. 4A˜4C illustrate a process of making the piezoelectric element shown in FIG. 1; FIG. 5 is a plan view showing a piezoelectric element according to a second embodiment of the present invention; FIG. 6 is a sectional view taken along lines VI-VI in FIG. 5; FIGS. 7A˜7C illustrate a process of making the piezoelectric electrode shown in FIG. 5; FIG. 8 is a plan view showing a touch screen according to a third embodiment of the present invention; FIG. 9 is an enlarged view showing a part of the touch screen shown in FIG. 8; FIG. 10 is a plan view showing a touch screen according to a fourth embodiment of the present invention; FIG. 11 is an enlarged view showing a part of the touch screen shown in FIG. 10; FIG. 12 is a plan view showing a SAW filter including piezoelectric elements of FIG. 1; and FIG. 13 is a graph showing the relation between the insertion loss and the hillock occurrence rate for Exemplary Devices 1˜2 and Comparative Devices 1-3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Reference is first made to FIGS. 1 and 2 illustrating a piezoelectric element X according to a first embodiment of the present invention. FIG. 1 is a plan view showing the piezoelectric element X, while FIG. 2 is a sectional view taken along lines II-II in FIG. 1. The piezoelectric element X, including a substrate 11, a piezoelectric layer 12 and electrodes 13 and 14, is arranged to generate and receive surface acoustic waves. The substrate 11 is rigid enough to ensure the integrity of the piezoelectric element and serves as a medium to propagate surface acoustic waves. The substrate 11 is formed of a non-piezoelectric material such as glass. The piezoelectric layer 12 is made of a piezoelectric material, thereby exhibiting the piezoelectric effect (the generation of electric polarization as a result of the application of mechanical stress) and the reverse piezoelectric effect (the production of a mechanical distortion as a result of the application of a voltage). Examples of piezoelectric material are AlN, ZnO, and ZnO doped with Mn. The thickness h of the piezoelectric layer 12 is 1.0˜3.0 μm, for example. As shown in FIG. 2, the lower electrode 13 is provided between the substrate 11 and the piezoelectric layer 12. According to the present embodiment, the “hillock occurrence rate” of the electrode 13 should be no greater than 0.1%, where the rate is defined in the following manner. Referring to FIG. 3, an electrode E is formed on a substrate S, to cover a given area A0 in the surface of the substrate S. In general the electrode E is undulated, as shown in the figure, thereby having hillocks of different heights. In this situation, first, an average height H0 of the electrode surface is calculated by a known surface height calculation method, for example. Then, a height H50 nm is determined, which is higher than the average height H0 by 50 nanometers. Supposing that the respective hillocks in the given area are truncated by the common horizontal plane at the height H50 nm, the section of each hillock gives a cutting area A1. Now, the “hillock occurrence rate” is defined as [the total of the cutting areas A1 of the respective hillocks]÷[the given area A0], or simply denoted by (ΣA1)/A0. As shown in FIG. 3, the above-mentioned hillock is a raised part of the electrode surface opposite to the substrate S, and it may be accompanied by a partial exfoliation of the electrode E from the substrate. The average height H0 of the electrode E may be calculated by reference to the surface of the substrate S. The hillock occurrence rate may not always be calculated over the total area A0 covered with the electrode E. Practically, only a limited region (unit region) in the area A0 may be selected for performing the same calculation as described above. The electrode 13 is formed of a metal material such as aluminum alloy. Preferably, the Al alloy contains 0.1˜3.0 wt % of a metal selected from the group consisting of Ti, Cr, Ni, Cu, Zn, Pd, Ag, Hf, W, Pt and Au. The Al alloy may contain two or more metals selected from the group. In this case, the concentration of each metal is in a range of 0.1˜3.0 wt %. Advantageously, the electrode 13 made of such an Al alloy has a smaller thermal expansion coefficient than a counterpart electrode made of pure aluminum. Accordingly, the occurrence and growth of hillocks on the electrode 13 can be appropriately restricted to ensure 0.1% or smaller hillock occurrence rate. As shown in FIG. 1, the electrode 13 is connected to a terminal 15 having an exposed portion projecting from under the piezoelectric layer 12. The thickness of the electrode 13 is in a range of 300˜600 nm, for example. As shown in FIG. 2, the upper electrode 14 is formed on the piezoelectric layer 12. The electrode 14 has a comb-like structure having a common base 14a and a plurality of branch electrodes 14b (simply called “branches 14b”). The branches 14b extend from the base 14a and are parallel to each other. The branches 14b face the lower electrode 13 via the piezoelectric layer 12. The branches 14b illustrated in FIG. 1 are straight, but the present invention is not limited to this. For example, each branch 14b may have some bents or may be curved smoothly. The thickness of the electrode 14 is in a range of 300˜600 nm, for example. The width d1 of each branch 14b may be 40˜60 μm, while the electrode pitch λ1 of the branches 14b may be 100˜150 μm. According to the present embodiment, the thickness h of the piezoelectric layer 12 and the electrode pitch λ1 of the branches 14b are determined to satisfy the following inequality. 0.005≦h/λ1≦0.1 The upper electrode 14 is formed of a conductive material which may be the same as the one used for making the lower electrode 13. As shown in FIG. 1, the upper electrode 14 is connected to a terminal 16. Reference is now made to FIGS. 4A-4C illustrating a process of making the piezoelectric element X. Specifically, as shown in FIG. 4A, an electrode 13, together with a terminal 15 (not shown) connected to the electrode 13, is formed on the upper surface of a substrate 11. Prior to the formation of the electrode 13 and the terminal 15, the upper surface of the substrate 11 may be subjected to detergent treatment for suppressing the occurrence of hillocks on the electrode 13 that tend to be induced in forming a piezoelectric layer to be described below. In the detergent treatment, the substrate surface is cleaned by e.g. reverse sputtering with the use of Ar plasma. For the reverse sputtering, the sputter pressure may be 0.5 Pa, the applied electric power 200 W, and the sputter time 1 minute. Through such detergent treatment, it is possible to remove dust, which can be cores or precipitants for the occurrence of hillocks on the electrode 13. To provide the electrode 13 and the terminal 15, a metal layer is formed on the substrate 11 by sputtering or vapor deposition, for example. At this stage, the substrate 11 is heated up to a temperature between 100 and 200° C. so that the forming of the metal layer on the substrate 11 is performed in a preheated condition (the technical significance of this preheating will be described below). After the metal layer is prepared, a resist pattern is formed on the metal layer, to cover the portions of the metal layer that are turned into the electrode 13 and the terminal 15. With the resist pattern used as a mask, the metal layer on the substrate 11 is subjected to etching for removal of the uncovered portions of the metal layer. Thus, the electrode 13 and the terminal 15 are obtained. Preferably, the surface of the resultant electrode 13 is subjected to etching by e.g. reverse sputtering with the use of Ar plasma, though the causality between this surface treatment and the advantage of the present invention still remains to be elucidated. The inventors speculate that the surface treatment may serve to remove an oxide film formed on the electrode 13, and this removal may have some positive effect on the prevention of hillocks on the electrode 13. After the electrode 13 and the terminal 15 are completed, a piezoelectric layer 12 is formed on the substrate 11, as shown in FIG. 4B. Specifically, a piezoelectric material is applied to the substrate 11 by sputtering, to produce a piezoelectric deposition which entirely covers the upper surface of the substrate 11. Then, with a prescribed resist pattern used as a mask, the piezoelectric deposition is subjected to etching to provide the desired piezoelectric layer 12. For the piezoelectric layer forming process, the substrate 11 is heated up to a temperature between 150˜200° C. (which is lower than a typical setting temperature for performing a piezoelectric layer forming process). In this connection, it should be recalled that the substrate 11 is heated up to a temperature between 100 and 200° C. in forming the electrode 13 and terminal 15, as previously described with reference to FIG. 4A. Accordingly, the temperature difference between the former process shown in FIG. 4A and the latter process shown in FIG. 4B can be sufficiently small, specifically, no greater than 100° C. (This maximum temperature difference is determined to be on the safe side. The maximum temperature difference may be 150° C. at most) With such a precaution, it is possible to prevent or reduce the thermal expansion of the electrode 13 when the piezoelectric layer 12 is formed. As a result, the occurrence or growth of hillocks on the electrode 13 is suppressed. According to the present invention, the temperature difference adjustment described above may be replaced by or accompanied by the growth rate adjustment for the layer 12 or the pressure adjustment for the sputtering gas. Referring to FIG. 4C, an upper electrode 14 is formed on the piezoelectric layer 12, together with a terminal 16 (not shown in the figure) connected to the electrode 14. Specifically, a conductive material is deposited on the substrate 11 and the piezoelectric layer 12 by sputtering or vapor deposition, for example. Then, a resist pattern is formed on the conductive layer to cover the portions to be turned into the electrode 14 and the terminal 16. With the resist pattern used as a mask, the conductive layer is subjected to etching. Thus, the electrode 14 and the terminal 16 are obtained. According to the present invention, the electrode 14 and the terminal 16 may be formed by a known printing technique. Specifically, Ag paste, for example, is applied to the substrate 11 and the piezoelectric layer 12 with a prescribed mask placed thereon. Then, after the mask is removed, the applied Ag paste is sintered or annealed to evaporate the solvent contained in the paste. Thus, the electrode 14 and the terminal 16 are obtained. The piezoelectric element X is produced in the above-described manner. As stated with reference to FIG. 4B, the formation of the piezoelectric layer 12 is performed under a condition in which the electrode 13 is prevented from undergoing occurrence or growth of hillocks. Thus, the hillock occurrence rate for the electrode 13 is no greater than 0.1%. In the piezoelectric element X, the thickness h of the piezoelectric layer 12 and the branch pitch λ1 of the electrode 14 are determined so that the inequality 0.005≦h/λ1≦0.1 is satisfied. In addition, the hillock occurrence rate for the electrode 13 is no greater than 0.1%. By virtue of these two arrangements, the piezoelectric element X exhibits a higher electromechanical conversion rate than is conventionally possible. Reference is now made to FIGS. 5 and 6 illustrating a piezoelectric element x′ according to a second embodiment of the present invention. FIG. 5 is a plan view showing the element X′, while FIG. 6 is a sectional view taken along lines VI-VI in FIG. 5. The piezoelectric element X′, including a substrate 11, a piezoelectric layer 12, a lower electrode 23 and an upper electrode 24, is designed to generate and receive surface acoustic waves. The element X′ of the second embodiment differs from the element X of the first embodiment in that the element X′ includes electrodes 23, 24 in place of the electrodes 13, 14. The substrate 11 and the piezoelectric layer 12 of the second embodiment are the same as those of the first embodiment described above. The lower electrode 23, arranged between the substrate 11 and the piezoelectric layer 12, has a comb-like structure that includes a common base 23a and a plurality of branches 23b extending in parallel to each other from the base 23a. In the illustrated example, each branch 23b is straight. However, according to the present invention, they may have some bents or may be curved smoothly. The thickness of the electrode 23 is 300˜600 nm, for example. The width d2 of each branch 23b may be 40˜60 μm. The pitch λ2 between the branches 23b may be 100˜150 μm. The thickness h of the piezoelectric layer 12 and the branch pitch λ2 are determined so that the inequality 0.005≦h/λ2≦0.1 is satisfied. The electrode 23 is connected to a terminal 25 having an exposed portion projecting from under the piezoelectric layer 12. In the second embodiment again, the hillock occurrence rate for the electrode 23 is no greater than 0.1%. The electrode 23 is formed of a metal material such as aluminum alloy. Preferably, the Al alloy contains 0.1˜3.0 wt % of a metal selected from the group consisting of Ti, Cr, Ni, Cu, Zn, Pd, Ag, Hf, W, Pt and Au. Advantageously, the electrode 23 made of such an Al alloy has a smaller thermal expansion coefficient than a counterpart electrode made of pure aluminum. Accordingly, the occurrence and growth of hillocks on the electrode 23 can be appropriately restricted to ensure 0.1% or smaller hillock occurrence rate. The upper electrode 24 is formed on the piezoelectric layer 12. The electrode 24 may be made of the same conductive material as that used for making the lower electrode 23. The thickness of the electrode 24 is 300˜600 nm, for example. The electrode 24 faces the respective branches 23b of the lower electrode via the piezoelectric layer 12, and is connected to a terminal 26. FIGS. 7A-7C show a process of making the piezoelectric element X′. Referring to FIG. 7A, a lower electrode 23 is formed on the substrate 11, together with a terminal 25 (not shown in the figure) connected to the electrode 23. As in the first embodiment, preferably the substrate 11 may be subjected to surface cleaning prior to the formation of the electrode 23 and the terminal 25, so that the hillock occurrence on the electrode 23 is suppressed in forming a piezoelectric layer to be described below. In forming the electrode 23 and the terminal 25, a conductive metal material is deposited on the substrate 11 by sputtering or vapor deposition, for example. At this stage, the substrate 11 is heated up to a prescribed temperature, as performed in the first embodiment, for the purposes of preventing the occurrence of hillocks on the electrode 23. Then, a resist pattern is formed on the conductive layer for covering the portions to be turned into the electrode 23 and the terminal 25. With the resist pattern used as a mask, the conductive layer is subjected to etching. Thus, the electrode 25 and the terminal 25 are produced on the substrate 11. Preferably, the resultant electrode 23 is subjected to surface etching by reverse sputtering, for example. Then, as shown in FIG. 7B, a piezoelectric layer 12 is formed on the substrate 11. Specifically, a piezoelectric material is deposited on the substrate 11 by sputtering. Then, with a prescribed resist pattern used as a mask, the piezoelectric deposition is subjected to etching, to produce the desired piezoelectric layer 12. In forming the piezoelectric layer 12, the substrate 11 is heated up to a prescribed temperature, as performed in the first embodiment, for preventing the occurrence of hillocks on the electrode 23. Referring to FIG. 7C, an upper electrode 24 is formed on the piezoelectric layer 12, together with a terminal 26 (not shown in the figure) connected to the electrode 24. The electrode 24 and the terminal 26 may be produced in the same manner as described with respect to the electrode 14 and the terminal 16 of the first embodiment. The piezoelectric element X′ produced in the above-described manner can enjoy the same advantage as the piezoelectric element X of the first embodiment. Specifically, the hillock occurrence rate for the electrode 23 can be no greater than 0.1%. In the piezoelectric element X′, the thickness h of the piezoelectric layer 12 and the branch pitch λ2 of the electrode 23 are determined so that the inequality 0.005≦h/λ2=≦0.1 is satisfied. In addition, the hillock occurrence rate for the electrode 23 is no greater than 0.1%. By virtue of these two arrangements, the piezoelectric element X′ exhibits a higher electromechanical conversion rate than is conventionally possible. Reference is now made to FIGS. 8 and 9 illustrating a SAW touch screen Y according to a third embodiment of the present invention. The touch screen Y includes a substrate 31, a piezoelectric layer 32, lower electrodes 33A˜33D and upper electrodes 34A˜34D. For clarity of illustration, the piezoelectric layer 32 is depicted in double-dot chain lines. The substrate 31 is a transparent plate through which surface acoustic waves propagate. The substrate 31 includes a detection region 31a and a marginal region 31b. In the figures, the boundary between the detection region 31a and the marginal region 31b is indicated by broken lines. The substrate 31 is made of a non-piezoelectric material such as glass and has a thickness of 0.7˜1.1 mm. In the illustrated example, the detection region 31a is rectangular (precisely, square), though the present invention is not limited to this. The detection region 31a is surrounded by the marginal region 31b, in which wave generators and wave receivers (to be described below) are provided. The piezoelectric layer 32 is provided on the marginal region 31b, but not on the detection region 31a. The layer 32 is formed of a piezoelectric material as the piezoelectric layer 12 of the first embodiment, thereby exhibiting the piezoelectric effect and the reverse piezoelectric effect. The thickness h of the piezoelectric layer 32 is 1.0˜3 μm, for example. The lower electrodes 33A˜33D are provided between the substrate 31 and the piezoelectric layer 32, and have a hillock occurrence rate of no greater than 0.1%. The electrodes 33A˜33D are formed of a metal material such as an aluminum alloy that contains 0.1-3.0 wt % of a metal selected from the group consisting of Ti, Cr, Ni, Cu, Zn, Pd, Ag, Hf, W, Pt and Au. The thickness of each electrode 33A˜33D is 300-600 nm, for example. The electrodes 33A˜33D are connected to terminals 35A˜35D, respectively. As seen from FIG. 8, each of the terminals 35A˜35D has an exposed portion projecting from under the piezoelectric layer 32. Each of the upper electrodes 34A˜34D, provided on the piezoelectric layer 32, has a comb-like structure that includes a common base 34a and a plurality of branches 34b extending from the base 34a. As shown in FIG. 8, most of the branches 34b, which are relatively long, have a bent, whereas the remaining branches 34b, which are relatively short, are straight along their entire length. Each of the relatively long branches 34b can be divided at its bent into two locally straight portions: an inner portion 34b′ (closer to the detection region 31a) and an outer portion 34b″ (farther from the detection region 31a). The inner portion 34b′ is angled at a prescribed degree with respect to the outer portion 34b″, so that the two portions 34b′, 34b″ extend in different directions. The angle to be made between the inner and the outer portions may depend on the ratio of the two lengths of the adjacent sides defining the rectangular detection region 31a. In the example illustrated in FIGS. 8 and 9, the detection region 31a is a square, meaning that the ratio of the length of one side (vertical side, for example) to the length of the adjacent side (horizontal side) is 1:1. In this case, the angle between the inner and the outer portions 34b′, 34b″ is 90°. The branches 34b face the electrode 33A˜33D via the piezoelectric layer 32. The thickness of the electrode 34 is 300˜600 nm, for example. Referring to FIG. 9, the width d3 of each branch 34b is 40˜60 μm, for example. Both the pitch λ3 between the inner portions 34b′ of the branches 34b and the pitch λ4 between the outer portions 34b″ are 100˜150 μm, for example, as in the above-mentioned branch pitch λ1. In each electrode 34, the pitches λ3 and λ4 may be the same or different from each other, depending on the operating manner of the touch screen Y. For any two of the electrodes 34A˜34D, the pitch λ3 and/or the pitch λ4 of one electrode may be the same or different from the pitch λ3 and/or the pitch λh4 of the other electrode, depending on the operating manner of the touch screen Y. The thickness h of the piezoelectric layer 32 and the branch pitch λ3 are determined to satisfy the inequality 0.005≦h/λ3≦0.1. Likewise, the thickness h of the piezoelectric layer 32 and the branch pitch λ4 are determined to satisfy the same inequality 0.005≦h/λ4≦0.1. The electrodes 34A˜34D are made of a conductive material which may be the same as the one used for making the electrodes 33A˜33D. As shown in FIG. 8, the electrodes 34A˜34D are connected to terminals 36A˜36D, respectively. The touch screen Y includes four piezoelectric elements X(XA˜XD) produced in accordance with the first embodiment of the present invention. The piezoelectric elements XA˜XD are arranged in the marginal region 31b of the substrate 31. As seen from the comparison between FIG. 8 and FIG. 1, the paired electrodes 33A-34A (and 33B-34B, 33C-34C, 33D-34D as well) correspond to the paired electrodes 13-14 of the piezoelectric element X, the piezoelectric layer 32 to the piezoelectric layer 12, and the substrate 31 to the substrate 11. Further, the terminal 35A-35D and the terminal 36A-36D correspond to the terminal 15 and the terminal. 16, respectively. The touch screen Y with four piezoelectric elements X may be produced in the same procedure as that described above with reference to FIGS. 4A˜4C. In operation of the touch screen Y, two facing piezoelectric elements XA and XC, for example, are energized intermittently, only one at a time. For the piezoelectric element XA, an alternating voltage is applied across the electrodes 33A and 34A via the terminals 35A and 36A for generation of waves. Upon application of the voltage, as shown in FIG. 8, two kinds of surface acoustic waves f1 and f2 of prescribed frequencies are produced by the element XA. The waves f1 propagate in a first direction perpendicular to the inner portions 34b′ of the branches 34b, while the waves f2 propagate in a second direction perpendicular to the outer portions 34b″ of the branches 34b. After propagating through the detection region 31a of the substrate 31, the wave f1 is received by the inner portions 34b′ of the piezoelectric element XD. As a result, a wave detection signal is outputted from the element XD via the terminals 35D and 36D. Specifically, referring to FIG. 8, the output of the signal begins upon reception of the wave f1 by the uppermost inner portion 34b′ of the element XD, and continues until the lowermost inner portion 34b′ of the element XD has completed the reception of the wave f1. Turning now to the wave f2, it is received by the outer portions 34b″ of the piezoelectric element XB after propagating through the detection region 31a of the substrate 31. As a result, a wave detection signal is outputted from the element XB via the terminals 35B and 36B. Specifically, referring to FIG. 8, the output of the signal begins upon reception of the wave f2 by the uppermost outer portion 34b″ of the element XB, and continues until the lowermost outer portion 34b″ of the element XB has completed the reception of the wave f2. Similarly to the above-described piezoelectric element XA, the piezoelectric element XC is energized to operate in the following manner. First, an alternating voltage is applied across the electrodes 33C and 34C via the terminals 35C and 36C for generation of waves. Upon application of the voltage, two kinds of surface acoustic waves f3 and f4 are produced by the element XC. The waves f3 propagate in a third direction perpendicular to the inner portions 34b′ of the branches 34b, while the waves f4 propagate in a fourth direction perpendicular to the outer portions 34b″ of the branches 34b. The piezoelectric element XC is energized immediately after the output process of the wave detection signals from the elements XB, XD has been completed. After propagating through the detection region 31a of the substrate 31, the wave f3 is received by the inner portions 34b′ of the piezoelectric element XB. As a result, a wave detection signal is outputted from the element XB via the terminals 35B, 36B. Referring to FIG. 8, the output of the signal begins upon reception of the wave f3 by the lowermost inner portion 34b′ of the element XB, and continues until the uppermost inner portion 34b′ of the element XB has completed the reception of the wave f3. The wave f4, after propagating through the detection region 31a of the substrate 31, is received by the outer portions 34b″ of the piezoelectric element XD. As a result, a wave detection signal is outputted from the element XD via the terminals 35D, 36D. The output of the signal begins upon reception of the wave f4 by the lowermost outer portion 34b″ of the element XD, and continues until the uppermost outer portion 34b″ of the element XD has completed the reception of the wave f4. While the touch screen Y is operating, the above-described series of processes (i.e., from the generation of waves f1, f2 by the element XA to the output of wave detection signals from the elements XB, XD based on the reception of the waves f3, f4) are performed repeatedly. When an area of the detection region 31a of the touch screen Y in operation is touched with a finger, for example, the waves f1˜f4 undergo amplitude reduction when passing the touched area. Due to the reduced amplitude of the surface acoustic waves, the wave detection signals from the elements XB, XD have a lower output level. Thus, it is possible to locate the touched area in the detection region 31a by analyzing the timing of the level reduction detected in the wave detection signals. In the above-described touch screen Y, the piezoelectric elements XB, XD may be used as a wave generator, and the remaining elements XA, XC as a wave receiver. The touch screen Y includes piezoelectric elements X having a high electro-mechanical conversion rate as a wave generator or wave receiver. Thus, the touch screen Y of the present invention needs a lower driving voltage than the conventional touch screens. The touch screen Y can also provide a greater detection accuracy than is conventionally possible. FIGS. 10 and 11 show a touch screen Y′ according to a fourth embodiment of the present invention. The touch screen Y′ is a SAW touch screen including a substrate 31, a piezoelectric layer 32, lower electrodes 43A˜43D and upper electrodes 44A˜44D. The touch screen Y′ differs from the above-described touch screen Y in that electrodes 43A˜43D and 44A˜44D are used in place of the electrodes 33A˜33D and 34A˜34D. However, the substrate 31 and the piezoelectric layer 32 of the touch screen Y′ are the same as those used for the touch screen Y. The lower electrodes 43A˜43D are arranged between the substrate 31 and the piezoelectric layer 32. Each of these electrodes has a comb-like structure that includes a common base 43a and a plurality of branches 43b extending from the base 43a. As shown in FIG. 10, most of the branches 43b, which are relatively long, have a bent, whereas the remaining branches 43b, which are relatively short, are straight along their entire length. Each of the relatively long branches 43b can be divided at its bent into two locally straight portions: an inner portion 43b′ (closer to the detection region 31a) and an outer portion 43b″ (farther from the detection region 31a). The inner portion 43b′ is angled at a prescribed degree with respect to the outer portion 43b″, so that the two portions 43b′, 43b″ extend in different directions. The angle to be made between the inner and the outer portions may depend on the ratio of the two lengths of the adjacent sides defining the rectangular detection region 31a. In the example illustrated in FIGS. 10 and 11, the detection region 31a is a square, meaning that the ratio of the length of one side (vertical side, for example) to the length of the adjacent side (horizontal side) is 1:1. In this case, the angle between the inner and the outer portions 43b′, 43b″ is 90°. The thickness of the electrode 43 is 300-600 nm, for example. Referring to FIG. 11, the width d4 of each branch 43b is 40˜60 μm, for example. Both the pitch λ5 between the inner portions 43b′ of the branches 43b and the pitch λ6 between the outer portions 43b″ are 100˜150 μm, for example, as in the above-mentioned branch pitch λ2. In each electrode 43, the pitches λ5 and λ6 may be the same or different from each other, depending on the operating manner of the touch screen Y′. For any two of the electrodes 43A˜43D, the pitch λ5 and/or the pitch λ6 of one electrode may be the same or different from the pitch λ5 and/or the pitch λ6 of the other electrode, depending on the operating manner of the touch screen Y′. The thickness h of the piezoelectric layer 32 and the branch pitch λ5 are determined to satisfy the inequality 0.005≦h/λ5≦0.1, Likewise, the thickness h of the piezoelectric layer 32 and the branch pitch λ6 are determined to satisfy the same inequality 0.005=≦h/λ6≦0.1. The hillock occurrence rate for the lower electrodes 43A-43D is no greater than 0.1%. The electrodes 43A˜43D may be formed of an aluminum alloy that contains 0.1˜3.0 wt % of a metal selected from the group consisting of Ti, Cr, Ni, Cu, Zn, Pd, Ag, Hf, W, Pt and Au. The thickness of the electrodes 43A˜43D is 300˜600 nm, for example. The electrodes 43A˜43D are connected to terminals 45A˜45D, respectively. Each of the terminals 45A˜45D has an exposed portion extending from under the piezoelectric layer 32. The upper electrodes 44A˜44D are provided on the piezoelectric layer 32, and formed of a conductive material which may be the same as that used for making the lower electrodes 43A˜43D. The thickness of the electrodes 44A˜44D is 300˜600 nm, for example. The electrodes 44A˜44D face the branches 43b of the lower electrodes via the piezoelectric layer 32. The electrodes 44A˜44D are connected to terminals 46A˜46D, respectively. The touch screen Y′ includes four piezoelectric elements X′ (XA′˜D′) according to the second embodiment, which are disposed in the marginal region 31b of the substrate 31. The paired electrodes 43A-44A (and 43B-44B, 43C-44C, 43D-44D as well) correspond to the paired electrodes 23-24 of the piezoelectric element X′, the piezoelectric layer 32 to the piezoelectric layer 12, and the substrate 31 to the substrate 11. Further, the terminal 45A-45D and the terminal 46A-46D correspond to the terminal 25 and the terminal 26, respectively. The touch screen Y′ with four piezoelectric elements X′ may be produced in the same procedure as that described above with reference to FIGS. 7A˜7C. In operating the touch screen Y′, the pair of the piezoelectric elements XA′and XC′ may be worked as a wave generator, while the other pair of the piezoelectric elements XB′ and XD′ as a wave receiver. It is possible to exchange the functions of these two pairs. The workings of the wave generators and receivers of the touch screen Y′ are the same as those described with respect to the touch screen Y. The touch screen Y′ includes piezoelectric elements X′ having a high electromechanical conversion rate as a wave generator or wave receiver. Thus, the touch screen Y′ of the present invention needs a lower driving voltage than the conventional touch screens. The touch screen Y′ can also provide a greater detection accuracy than is conventionally possible. [Exemplary Device 1] Production of SAW Filters Referring to FIG. 12, a transversal SAW filter was produced with the use of two piezoelectric elements X of the first embodiment. As shown in the figure, the piezoelectric elements X are arranged in a normally facing position. To make the filter X, first, an Al-alloy layer (300 nm in thickness) was formed on a glass substrate 11 by sputtering (First Layer Forming Step). The aluminum alloy used for this step contained 2.0 wt % of copper (Cu). In the sputtering, use was made of an Al-alloy target containing 2.0 wt % of Cu. The sputter gas was argon (Ar) and had a pressure of 0.5 Pa. The discharge power was lkW. Then, the Al-alloy layer was subjected to etching, with a prescribed resist pattern used as a mask. As a result, two facing electrodes 13 and terminals 15 were formed on the substrate 11. The resultant electrodes 13 was subjected to surface etching treatment by reverse sputtering with the use of Ar plasma. Then, a ZnO layer (piezoelectric layer) with a thickness of 2.2 μm was formed on the substrate 11 by reactive sputtering (Second Layer Forming Step). Specifically, in forming the ZnO layer, use was made of a sintered ZnO target, and Ar and O2 gases were utilized for the sputtering gas. The flow ratio of the Ar gas to the O2 gas was 4:1. The sputtering gas had a pressure of 0.3 Pa, and the discharge power was 3 kW. During the second layer forming step, the substrate 11 was heated so that it was kept at 300° C. The layer forming process continued for 20 minutes. Thereafter, the resultant ZnO layer was subjected to etching, with a prescribed resist pattern used as a mask, whereby the desired piezoelectric layer 12 was produced. Then, an Al-alloy layer (300 nm in thickness) was formed on the substrate 11 and the piezoelectric layer 12 by sputtering (Third Layer Forming Step). In the sputtering, uses was made of an Al-alloy target containing 2.0 wt % of Cu. The sputtering gas was Ar, and had a pressure of 0.5 Pa. The discharge power was 1 kW. The resultant Al-alloy layer was subjected to etching, with a prescribed resist pattern used as a mask. Thus, the electrodes 14 and the terminals 16 were obtained. As shown in FIG. 12, each electrode 14 includes a common base 14a and a number of parallel branches 14b extending from the base 14a. The width d1 of each branch 14b is 44 μm, and the pitch λ1 between the branches 14b is 100 μm. In accordance with the above procedure, a prescribed number of filters as shown in FIG. 12 were produced. In each filter, the thickness h of the piezoelectric layer 12 and the branch pitch λ1 were determined to satisfy the inequality 0.005≦h/λ1≦0.1. Measurement of Hillock Occurrence Rate The hillock occurrence rate was measured with respect to samples each produced in the following manner. First, an Al-alloy layer (containing 2.0 wt % of Cu and having a thickness of 300 nm) was formed on a glass substrate under the same condition as that described above with respect to the first layer forming step. Then, the glass substrate with the Al-alloy layer formed thereon was subjected to heating treatment by which the substrate was heated at 300° C. for 20 minutes. It should be noted here that these heating temperature and time are the same as the above-mentioned heating temperature and time adopted for the second layer forming step. In this manner, substantially the same conditions for the occurrence and growth of hillocks in the SAW filers are realized in the samples. The obtained samples were subjected to inspection, whereby the surfaces of the Al-alloy layers of the respective samples were examined by an atomic force microscope (AFM) for determination of the hillock occurrence rate. The result was that the hillock occurrence rate for the Al-alloy layer of the samples was 0.01%. This implies that the hillock occurrence rate for the electrode 13 of the piezoelectric element X (FIG. 12) was also 0.01%. Measurement of Insertion Loss With respect to the SAW filters shown in FIG. 12, the insertion loss between the input signal and the output signal was measured. The result was that the insertion loss of the filter was −12 dB, which is plotted in a graph shown in FIG. 13 (see ED1). The abscissa of the graph represents hillock occurrence rate (logarithmic scale), while the ordinate represents insertion loss (dB). [Exemplary Device 2] SAW filters were produced in the same procedure as that described above with respect to Exemplary Device 1, except that the Al-alloy layer of Device 2 produced in the first layer forming step was made to contain 1.0 wt % of Cu (note that the counterpart layer of Device 1 contained 2.0 wt % of Cu). Consequently, the electrode 13 of Device 2 was formed of an Al-alloy containing 1.0 wt % of Cu. In the filter of Device 2, the thickness h of the piezoelectric layer 12 was 2.2 μm, and the branch pitch λ1 was 100 μm. Thus, the inequality 0.005≦h/λ1≦0.1 was satisfied (in the present case, h/λ1=2.2/110=0.02). For Exemplary Device 2, the hillock occurrence rate was 0.009%, and the insertion loss was −11 dB. The results are plotted in the graph of FIG. 13 (see ED2). [Comparative Devices 1˜3] Comparative SAW filters 13 were produced in the same procedure as that described above with respect to Exemplary Device 1, except that the Al-alloy layer of Device 1 produced in the first layer forming step was replaced with a pure aluminum layer (comparative filter 1), an Al-alloy layer containing 1.0 wt % of Si (comparative filter 2), or an Al-alloy layer containing 0.5 wt % of Si (comparative filter 3). In each of the comparative filters 13, the thickness h of the piezoelectric layer was 2.2 μm, and the branch pitch X was 100 μm (thus, the inequality 0.005≦h/λ≦0.1 was satisfied). The hillock occurrence rates for the electrodes between the glass substrate and the piezoelectric layer were 30% (comparative filter 1), 0.3% (comparative filter 2), and 0.7% (comparative filter 3). The insertion losses were—50 dB (comparative filter 1), −42 dB (comparative filter 2), and −48 dB (comparative filter 3). These measurements are plotted in the graph of FIG. 13 (see CD1˜CD3). [Evaluation of Exemplary Devices] As shown in FIG. 13, the exemplary filters 1 and 2 (the hillock occurrence rate≦0.1%) have a lower insertion loss than the comparative filters 1-3 (the hillock occurrence rate≦0.1%). The inventors speculate that the lower insertion loss in each exemplary filter is due to a relatively high electromechanical conversion rate which results from the lower hillock occurrence rate. The present invention being thus described, it is obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to those skilled in the art are intended to be included within the scope of the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a piezoelectric element to generate or receive surface acoustic waves. The present invention also relates to a SAW touch screen incorporating piezoelectric elements used as a wave generator or receiver. 2. Description of the Related Art Touch screens or touch panels are used as data input units to enable users to interact with a computer system for e.g. factory automation equipment, office automation equipment or automatic measuring device. As known, a touch screen is a force-sensitive device designed to detect an area on the screen that the user touches with his or her finger, for example. The computer system performs required data processing based on the information of a location detected by the touch screen and other necessary data. Recently, attention has been drawn to “SAW” touch screens in which the touched area is detected based on the surface acoustic wave (SAW). A typical SAW touch screen includes a transparent substrate that has a detection region and a marginal region surrounding the detection region. The marginal region is provided with a plurality of piezoelectric elements as a wave generator or wave receiver. Examples of SAW touch screens are disclosed in Japanese patent application laid-open Nos. H06-149459 and H10-55240. A conventional piezoelectric element used as a wave generator or receiver is constituted by an interdigitated transducer (IDT) patterned on the marginal region for each element and a piezoelectric layer formed on the marginal region to cover the IDT. The IDT consists of a pair of comb-like conductors each having a prescribed number of parallel electrode fingers (conductive branches). The electrode fingers of one comb-like conductor are arranged alternately with and parallel to those of the other comb-like conductor. The piezoelectric layer is formed of a piezoelectric material, which exhibits the piezoelectric effect (generation of electric polarization as a result of the application of mechanical stress) and the reverse piezoelectric effect (production of a mechanical distortion as a result of the application of a voltage). Upon application of an alternating voltage to the IDT of a piezoelectric element, an electric field is generated between adjacent electrode fingers. As a result, mechanical distortions occur in the piezoelectric layer due to the reverse piezoelectric effect, thereby producing elastic waves in the piezoelectric layer. In this process, the most strongly excited wave is a wave whose wavelength is equal to the pitch of the electrode fingers of the IDT. The produced elastic waves propagate along the surface of the substrate, to reach the wave-receiving piezoelectric elements. At these wave receivers, alternating electric fields are generated between the electrode fingers of the IDT due to the piezoelectric effect in the piezoelectric layer. Accordingly, an electromotive force is produced, and an alternating current is outputted from the IDT. In operation of the SAW touch screen, the wave-generating piezoelectric elements produce surface acoustic waves. The surface acoustic waves propagate through the detection region of the substrate, to be received by particular piezoelectric elements serving as the wave receivers. When a finger is held in contact with an area in the detection region, the amplitude of the surface acoustic-wave decreases as the wave passes through the contact point. The damping of the wave is detected and analyzed to locate the contact point in the detection region. In a SAW touch screen, the electromechanical conversion rate of the piezoelectric elements should be as high as possible for attaining reduction of the driving voltage and for improving the detection accuracy. Specifically, with a high electromechanical conversion rate, each piezoelectric element can generate elastic waves efficiently in response to the applied voltage (when used as a wave generator), or can output an alternating current efficiently in response to the received elastic wave (when used as a wave receiver). In such a situation, the insertion loss between input and output signals for piezoelectric elements is small, whereby the reduction of driving voltage and the improvement of detection accuracy are realized. In the conventional SAW touch screens, however, the piezoelectric elements do not have a sufficiently high electro-mechanical conversion rate for attaining a desired reduction of the driving voltage and improvement of the detection accuracy. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention has been proposed under the circumstances described above. It is, therefore, an object of the present invention to provide a piezoelectric element having a higher electromechanical conversion rate than the conventional elements. Another object of the present invention is to provide a SAW touch screen incorporating such a piezoelectric element for use as a wave generator or wave receiver. According to a first aspect of the present invention, there is provided a piezoelectric element comprising: a substrate; a piezoelectric layer having a first surface and a second surface opposite to the first surface, the first surface facing the substrate, the piezoelectric layer having a thickness h; a first electrode arranged between the substrate and the first surface of the piezoelectric layer; and a second electrode held in contact with the second surface of the piezoelectric layer. One of the first electrode and the second electrode includes a common base and a plurality of parallel branches extending from the base and spaced from each other by a prescribed pitch λ. The other of the first electrode and the second electrode includes a portion that faces the branches via the piezoelectric layer. The thickness h of the piezoelectric layer and the branch pitch λ are determined to satisfy an inequality 0.005≦h/λ≦ 0.1 . In addition, the first electrode has a hillock occurrence rate which is no greater than 0.1%. The above-formulated setting of the thickness h and the pitch λ is advantageous for providing a high electro-mechanical conversion rate in the piezoelectric element. In the prior art devices, however, a sufficiently high electro-mechanical conversion rate fails to be obtained as the thickness h of the piezoelectric layer is made smaller, even if the above relation 0.005≦h/λ≦0.1 is observed. In light of this, according to the present invention, the hillock occurrence rate of the first electrode is no greater than 0.1%. The inventors have found that such a low hillock occurrence rate ensures a required high electromechanical conversion rate even when the thickness h of the piezoelectric layer is very small (on the order of micrometers, for example). The definition of the hillock occurrence rate is found in DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS below. Preferably, the common base and the branches may belong to the first electrode. Preferably, the first electrode may be formed of an aluminum alloy containing 0.1˜3.0 wt % of a metal selected from a group consisting of Ti, Cr, Ni, Cu, Zn, Pd, Ag, Hf, W, Pt and Au. This arrangement serves to make the hillock occurrence rate of the first electrode equal to or lower than 0.1%. This is because the aluminum alloy has a smaller coefficient of thermal expansion than pure aluminum. Preferably, the piezoelectric layer may be formed of ZnO doped with Mn. This arrangement is advantageous for preventing e.g. Al contained in the first electrode from diffusing into the piezoelectric layer. As a result, the piezoelectric element can maintain the high electro-mechanical conversion rate. According to a second aspect of the present invention, there is provided a touch screen comprising: a substrate including a detection region and a marginal region surrounding the detection region; a wave generator arranged in the marginal region for generating a surface acoustic wave in the substrate; and a wave receiver arranged in the marginal region for receiving the surface acoustic wave. Further, each of the wave generator and the wave receiver comprises: a piezoelectric layer having a first surface facing the substrate and a second surface opposite to the first surface, the piezoelectric layer having a thickness h; a first electrode arranged between the substrate and the first surface of the piezoelectric layer; and a second electrode held in contact with the second surface of the piezoelectric layer. One of the first electrode and the second electrode includes a common base and a plurality of parallel branches extending from the base, the branches being spaced from each other by a pitch λ. The other of the first electrode and the second electrode includes a portion that faces the branches via the piezoelectric layer. As in the piezoelectric element of the first aspect, the thickness h and the pitch λ are determined to satisfy an inequality 0.005≦h/λ≦0.1, and the first electrode has a hillock occurrence rate which is no greater than 0.1%. Preferably, the common base and the branches may belong to the first electrode. The first electrode may be formed of an aluminum alloy containing 0.1˜3.0 wt % of a metal selected from a group consisting of Ti, Cr, Ni, Cu, Zn, Pd, Ag, Hf, W, Pt and Au. The piezoelectric layer may be formed of ZnO doped with Mn. Other features and advantages of the present invention will become apparent from the detailed description given below with reference to the accompanying drawings. | 20040220 | 20070213 | 20050407 | 57312.0 | 0 | PATEL, NITIN | PIEZOELECTRIC ELEMENT AND TOUCH SCREEN UTILIZING THE SAME | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,782,103 | ACCEPTED | Wick trimmer | A wick trimmer apparatus is herein provided and more particularly, a wick trimmer with a measuring foot that facilitates the effective cutting of a wick to an appropriate length. The wick trimmer has two arms and a measuring foot connected to the second arm that determines the length of a wick protruding from the top portion of a candle. The wick trimmer also has a debris tray formed from a top portion of the measuring foot and a top portion of a base of the first arm. The angles of the arms facilitate both the effective trimming of wicks and the ability of the wick trimmer to access a candle housed within a narrow candle container. | 1. A wick trimmer comprising: a first cutting arm; a second cutting arm connected to said first cutting arm; and a base mounted to said second cutting arm which determines the length of a wick which is allowed to remain at the top of a candle. 2. The wick trimmer of claim 1, wherein said base has a thickness of between about ⅛″ and about ⅞″. 3. The wick trimmer of claim 1, wherein said base has a cutting edge. 4. The wick trimmer of claim 1, wherein said first and second cutting arms are configured so as to create variable cutting strength along said cutting edge as said first cutting arm and said second cutting arm are directed to a closed position. 5. The wick trimmer of claim 4, wherein said variable cutting strength is created by a difference in angle of between about 0.25° and about 1.25° between a bottom angle of said first cutting arm and a bottom angle of said second cutting arm. 6. The wick trimmer of claim 4, wherein said variable cutting strength is created by a difference in angle of between about 0.50° and about 1.00° between a bottom angle of said first cutting arm and a bottom angle of said second cutting arm. 7. The wick trimmer of claim 4, wherein said variable cutting strength is created by a difference in angle of about 0.75° between a bottom angle of said first cutting arm and a bottom angle of said second cutting arm. 8. The wick trimmer of claim 7, wherein said bottom angle of said first cutting arm is about 105.750 and said bottom angle of said second cutting arm is about 105.00°. 9. The wick trimmer of claim 1, wherein a top angle of said first cutting arm forms an angle of between about 100° and about 110°. 10. The wick trimmer of claim 1, wherein a top angle of said second cutting arm forms an angle of between about 100° and about 110°. 11. The wick trimmer of claim 1, wherein the wick trimmer comprises stainless steel. 12. The wick trimmer of claim 1, wherein the cutting edge is serrated. 13. The wick trimmer of claim 1, wherein said second cutting arm is pivotably connected to said first cutting arm. 14. The wick trimmer of claim 1, wherein said base is a measuring foot that determines the length of a wick which is to be allowed to remain at the top of a candle. 15. The wick trimmer of claim 1, further comprising a debris tray, formed from a top portion of said base. 16. A wick trimmer comprising: a first cutting arm; a second cutting arm, wherein said second cutting arm is rotably connected to said first cutting arm; a base having a thickness of between about ⅛″ and about ⅞″, wherein said base is connected to said second cutting arm and wherein said base corresponds to the length of a wick which is to be allowed to remain at the top of a candle; and a cutting edge formed along said base. 17. The wick trimmer of claim 16, wherein said base has a thickness of about ⅛″ and about ½″. 18. The wick trimmer of claim 16, wherein said base has a thickness of about ¼″. 19. The wick trimmer of claim 16, further comprising a debris tray, formed within a top portion of said base and a top portion of an end of said first cutting arm when said first cutting arm and second cutting arm are in a closed position. 20. The wick trimmer of claim 16, said first cutting arm having a top angle of between about 95.00° and about 115.00° and a bottom angle at least about 0.25° greater than the top angle. 21. The wick trimmer of claim 16, said second cutting arm having a top angle and a bottom angle of between about 95.00° and about 115.00°. 22. The wick trimmer of claim 16, wherein the difference between said top angle and said bottom angle of said first cutting arm creates variable cutting strength along said cutting edge as said first cutting arm and said second cutting arm are directed to a closed position. 23. The wick trimmer of claim 16, wherein a middle portion of said first cutting arm is angled between about 170° and about 175° and a middle portion of said second cutting arm is angled between about 170° and about 175°, allowing said first cutting arm and said second cutting arm to overlap so that said first cutting arm and said second cutting arm can connect. 24. The wick trimmer of claim 16, wherein said bottom angle of said first cutting arm is about 105.75° and said bottom angle of said second cutting arm is about 105.00°. 25. The wick trimmer of claim 16, wherein a first end of said first cutting arm forms an angle of between about 100° and about 110°. 26. The wick trimmer of claim 16, wherein a first end of said second cutting arm forms an angle of between about 100° and about 110°. 27. The wick trimmer of claim 16, wherein said cutting edge is serrated. 28. The wick trimmer of claim 16, wherein said wick trimmer is configured so as to fit into a cover of a candle, wherein the cover is at least about 1.5 inches in diameter. 29. The wick trimmer of claim 16, wherein said cutting edge cuts through a wick. 30. A wick trimmer comprising: a first cutting arm; and a second cutting arm connected to said first cutting arm, wherein said first and second cutting arms are configured so as to create variable cutting strength along said cutting edge as said first cutting arm and said second cutting arm are directed to a closed position. 31. The wick trimmer of claim 30, wherein said variable cutting strength is created by a difference in angle of between about 0.25° and about 1.25° between a bottom angle of said first cutting arm and a bottom angle of said second cutting arm. 32. The wick trimmer of claim 30, wherein said variable cutting strength is created by a difference in angle of between about 0.35° and about 1.15° between a bottom angle of said first cutting arm and a bottom angle of said second cutting arm. 33. The wick trimmer of claim 30, wherein said variable cutting strength is created by a difference in angle of about 0.75 between a bottom angle of said first cutting arm and a bottom angle of said second cutting arm. 34. A method for trimming a wick to a pre-determined length comprising the steps of: providing a first cutting arm; providing a second cutting arm connected to said first cutting arm; and providing a base mounted to said second cutting arm which determines the length of a wick which is allowed to remain at the top of a candle. 35. The method of claim 34, further comprising the step of providing variable cutting strength that is created by a difference in angle of between about 0.25° and about 1.25° between a bottom angle of said first cutting arm and a bottom angle of said second cutting arm. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wick trimmer. More particularly, the present invention relates to a wick trimmer with a measuring foot that facilitates the effective cutting of a wick to an appropriate length. 2. Background and Related Art Wick trimmers are often used in order to shorten a wick to an appropriate length. Sometimes wicks need to be shortened because candles are sold with wicks that are too long or because candle wicks become too long after a period of burning. Failing to trim wicks to an appropriate length can result in a fire hazard. However, achieving a proper wick trim can be problematic. Existing wick trimmers fail to accurately or easily measure an appropriate wick length. This is because they either rely on the human eye to judge the appropriate wick length or because they are difficult to negotiate. Many existing wick cutters also fail to effectively cut through wicks. Wicks consist of a metal filament that presents difficulties for many wick cutters that are either unsharpened or not sturdy enough to create clean wick cuts. In addition, many wick cutters do not fit into some designs of candle holders. For instance, wick cutters with scissor-like designs do not fit into narrow candle holders. Also, many wick cutters fail to catch the wick after it is cut, leaving a candle cluttered with old wick pieces. SUMMARY OF THE INVENTION The present invention relates to a novel wick trimmer. More particularly, the present invention relates to a wick trimmer with a measuring foot that facilitates the effective cutting of a wick to an appropriate length. Implementation of the present invention takes place in association with a candle, a wick and a wick trimmer. In one implementation, the wick trimmer cuts a wick to a predetermined length. This increases the safety of candle usage by decreasing the fire hazard caused by a long wick. Where multiple-wicks are presented near each other, such as in multi-wick candles or a set of candles, the uniformity of wick length also creates a more aesthetically pleasing appearance. In another implementation, the measuring foot has a uniform thickness. The thickness of the measuring foot facilitates the effectiveness of the cuts produced by the wick trimmer. In a related implementation, the measuring foot has a cutting edge, which when combined with the thickness of the measuring foot, produces effective, clean cuts on all parts of the cutting edge. In yet another implementation, the measuring foot has a debris tray formed on the top portion of the measuring foot. The debris tray catches the wick after it is cut, leaving the candle uncluttered by old wick pieces. In another implementation, the wick trimmer comprises two arms that are connected together. Variable cutting strength is created along the cutting edge because the angles of the arms are slightly different. In a related implementation, the angles of the arms allow the wick trimmer to access the wicks of candles that are housed in candle holders with very narrow openings. In another implementation, the middle portion of both arms is angled to a degree that facilitates the overlap and attachment of both arms onto each other. In another implementation, the wick trimmer is made out of stainless steel. In another implementation, the cutting edge is serrated. While the methods and processes of the present invention have proven to be particularly useful in the area of wick trimming, those skilled in the art can appreciate that the methods and processes can be used in a variety of different applications and in a variety of different areas of manufacture to yield effective trimming results. These and other features and advantages of the present invention will be set forth or will become more fully apparent in the description that follows and in the appended claims. The features and advantages may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. Furthermore, the features and advantages of the invention may be learned by the practice of the invention or will be obvious from the description, as set forth hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS In order that the manner in which the above recited and other features and advantages of the present invention are obtained, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which are illustrated in the appended drawings. Understanding that the drawings depict only typical embodiments of the present invention and are not, therefore, to be considered as limiting the scope of the invention, the present invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: FIG. 1 provides an illustration of a representative embodiment of the present invention, wherein a wick trimmer is in closed position. FIG. 2 illustrates a top view of the first cutting arm. FIG. 3 illustrates a top view of the second cutting arm. FIG. 4 illustrates an alternative view of the second cutting arm. FIG. 5a illustrates a side view of the first cutting arm. FIG. 5b illustrates a side view of the second cutting arm. FIG. 6 provides an illustration of a representative embodiment of the present invention, wherein the wick trimmer is in an open position and is also shown along with a candle, candle container and wick. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wick trimmer. More particularly, the present invention relates to a wick trimmer with a measuring foot that facilitates the effective cutting of a wick to an appropriate length. FIG. 1 provides an illustration of a representative embodiment of the present invention, wherein a wick trimmer 20 is in a closed position 22 that includes a first cutting arm 30, a second cutting arm 32, a measuring foot 34, a pin 36, and a debris tray 38. In this embodiment, the measuring foot 34, which is also referred to as a base or an end, has a uniform thickness of about ¼″. This thickness is the most presently preferred thickness of the preferred embodiment. However, other presently preferred embodiments not shown in FIG. 1 have a thickness of between about ⅛″ and about ⅞″ or more preferably, a thickness of between about ⅛″ and about ½″. In some embodiments, the thickness is uniform and in others it is not. These thicknesses, combined with the sturdy, stainless steel material out of which the wick cutter is made, facilitate a clean, consistent cut of the wick. As can be seen in FIG. 1, the debris tray 38 is formed from a top portion of the measuring foot 40 and a top portion of a base of the first cutting arm 42. When the wick trimmer is in the closed position 22, as is shown in FIG. 1, a trimmed portion of a wick 44 (not shown) sits within the debris tray 38 and can be easily removed from a candle 46 (not shown) or from a candle container 48 (not shown). Also shown in this embodiment of the present invention are oval handles 50, which aid a user 52 (not shown) in manipulating the wick trimmer 20. In addition, FIG. 1 shows a middle portion of the first cutting arm 54 and a middle portion of the second cutting arm 56 that are both angled. The angular configuration allows the first cutting arm 30 and the second cutting arm 32 to overlap such that pin 36 can securely couple the first cutting arm 30 and the second cutting arm 32. FIG. 2 shows a top view of the first cutting arm 30. This view highlights the top portion of the first cutting arm 42 that forms the debris tray 38 when the wick trimmer 20 is in the closed position 22. FIG. 3 shows a top view of the second cutting arm 32. This view highlights the top portion of the measuring foot 40 that forms the debris tray 38 when the wick trimmer 20 is in the closed position 22. FIG. 4 shows an alternative view of the second cutting arm 32. This view highlights the thickness of the measuring foot 34. As seen in FIG. 5a, a first portion of the first cutting arm 76 and a second portion of the first cutting arm 78 form a top angle of the first cutting arm 58 and a third portion of the first cutting arm 80 and a fourth portion of the first cutting arm 82 form a bottom angle of the first cutting arm 60. Similarly, in FIG. 5b, a first portion of the second cutting arm 84 and a second portion of the second cutting arm 86 form a top angle of the second cutting arm 62 and a third portion of the second cutting arm 88 and a fourth portion of the second cutting arm 90 form a bottom angle of the second cutting arm 64. FIG. 5a shows a side view of the first cutting arm 30. This view illustrates an embodiment of the present invention where the top angle of the first cutting arm 58 is different than the bottom angle of the first cutting arm 60. In this particular, non-limiting example, the top angle of the first cutting arm 58 is about 105.00° and the bottom angle of the first cutting arm 60 is about 105.75°. FIG. 5b shows a side view of the second cutting arm 32. This view illustrates an embodiment of the present invention where the top angle of the second cutting arm 62 is the same as the bottom angle of the second cutting arm 64. In this particular, non-limiting example, the top angle of the second cutting arm 62 and the bottom angle of the second cutting arm 64 are both about 105.00°. Thus, when the first cutting arm 30 and the second cutting arm 32 of FIGS. 5a and 5b are coupled together, variable cutting strength is created along a cutting edge 66 because of the difference in angles between the bottom angle of the first cutting arm 60 and the bottom angle of the second cutting arm 64. This embodiment shows that the most presently preferred difference in angle between the bottom angle of the second cutting arm 64 and the bottom angle of the first cutting arm 60 is about 0.75°. In other presently preferred embodiments, this difference is between about 0.25° and about 1.25°, more preferably between about 0.35° and about 1.15° and, most preferably between about 0.50° and about 1.00°. This variable cutting strength in part contributes to the surprisingly successful cutting results of the wick trimmer 20, when compared against other wick cutters. In addition, in other embodiments, a top angle of the first cutting arm 58 and a top angle of the second cutting arm 62 have a range of between about 100° and about 110°. FIG. 6 provides an illustration of a representative embodiment of the present invention, wherein the wick trimmer 20 is in an open position 70. This embodiment also shows candle 46, candle container 48 and wick 72. This embodiment shows how the first cutting arm 30 and the second cutting arm 32 allow the wick trimmer 20 to fit within candle container 48. It also illustrates how measuring foot 34 is placed against a top surface of candle 74 in order to accurately measure the length of the wick 72 that should remain after trimming. Thus, as discussed herein, the embodiments of the present invention embrace the field of wick trimmers. More particularly, the present invention relates to a wick trimmer with a measuring foot that facilitates the effective cutting of a wick to an appropriate length. The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a wick trimmer. More particularly, the present invention relates to a wick trimmer with a measuring foot that facilitates the effective cutting of a wick to an appropriate length. 2. Background and Related Art Wick trimmers are often used in order to shorten a wick to an appropriate length. Sometimes wicks need to be shortened because candles are sold with wicks that are too long or because candle wicks become too long after a period of burning. Failing to trim wicks to an appropriate length can result in a fire hazard. However, achieving a proper wick trim can be problematic. Existing wick trimmers fail to accurately or easily measure an appropriate wick length. This is because they either rely on the human eye to judge the appropriate wick length or because they are difficult to negotiate. Many existing wick cutters also fail to effectively cut through wicks. Wicks consist of a metal filament that presents difficulties for many wick cutters that are either unsharpened or not sturdy enough to create clean wick cuts. In addition, many wick cutters do not fit into some designs of candle holders. For instance, wick cutters with scissor-like designs do not fit into narrow candle holders. Also, many wick cutters fail to catch the wick after it is cut, leaving a candle cluttered with old wick pieces. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention relates to a novel wick trimmer. More particularly, the present invention relates to a wick trimmer with a measuring foot that facilitates the effective cutting of a wick to an appropriate length. Implementation of the present invention takes place in association with a candle, a wick and a wick trimmer. In one implementation, the wick trimmer cuts a wick to a predetermined length. This increases the safety of candle usage by decreasing the fire hazard caused by a long wick. Where multiple-wicks are presented near each other, such as in multi-wick candles or a set of candles, the uniformity of wick length also creates a more aesthetically pleasing appearance. In another implementation, the measuring foot has a uniform thickness. The thickness of the measuring foot facilitates the effectiveness of the cuts produced by the wick trimmer. In a related implementation, the measuring foot has a cutting edge, which when combined with the thickness of the measuring foot, produces effective, clean cuts on all parts of the cutting edge. In yet another implementation, the measuring foot has a debris tray formed on the top portion of the measuring foot. The debris tray catches the wick after it is cut, leaving the candle uncluttered by old wick pieces. In another implementation, the wick trimmer comprises two arms that are connected together. Variable cutting strength is created along the cutting edge because the angles of the arms are slightly different. In a related implementation, the angles of the arms allow the wick trimmer to access the wicks of candles that are housed in candle holders with very narrow openings. In another implementation, the middle portion of both arms is angled to a degree that facilitates the overlap and attachment of both arms onto each other. In another implementation, the wick trimmer is made out of stainless steel. In another implementation, the cutting edge is serrated. While the methods and processes of the present invention have proven to be particularly useful in the area of wick trimming, those skilled in the art can appreciate that the methods and processes can be used in a variety of different applications and in a variety of different areas of manufacture to yield effective trimming results. These and other features and advantages of the present invention will be set forth or will become more fully apparent in the description that follows and in the appended claims. The features and advantages may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. Furthermore, the features and advantages of the invention may be learned by the practice of the invention or will be obvious from the description, as set forth hereinafter. | 20040219 | 20060523 | 20050825 | 70277.0 | 5 | PAYER, HWEI-SIU C | WICK TRIMMER | SMALL | 0 | ACCEPTED | 2,004 |
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10,782,371 | ACCEPTED | Data repair | The invention relates to a method for data repair in a system capable of one-to-many transmission. The method comprises transmitting data from a sender to at least one receiver and provides for various sender driven or receiver driven repair methods of missing data. | 1. A method for data repair in a system capable of one-to-many transmission, the method comprising: transmitting data from a sender to at least one receiver; providing sender driven or receiver driven repair of missing data, concerning data missing at the receiver. 2. The method of claim 1, wherein repair is implemented in a repair session comprising one of the following: re-transmitting missing data in total; re-transmitting only a part of missing data; and repeating original transmission in a whole. 3. The method of claim 1, wherein an error rate parameter is transmitted from sender to receiver to be used as a threshold in requesting repair of missing data. 4. The method of claim 3, wherein said error rate parameter is used to calculate the threshold in a time and/or data window. 5. The method of claim 1, wherein the method comprises indicating to receivers that a session or part of it will be re-transmitted in a point-to-multipoint fashion. 6. The method of claim 5, wherein said indication is implemented with the aid of a point-to-multipoint repair token. 7. The method of claim 1, wherein the method comprises generating random or pseudo-random time dispersion of repair requests to be sent from receiver(s) to sender. 8. The method of claim 7, wherein the method provides for statistically uniform distribution over a relevant period of time. 9. The method of claim 1, wherein the method comprises using receiver roles. 10. The method of claim 9, wherein one or more of the roles comprise a back-off time given by offset time and random time period. 11. The method of claim 9, wherein one or more of the roles comprise flag-holder behaviour. 12. The method of claim 1, wherein the method comprises sharing time parameter(s) and/or data parameter(s) and/or error parameter(s) between sender and receiver by pre-configuring. 13. The method of claim 1, wherein the method comprises indicating from server to receiver, after receipt of a repair request, that repair will be performed only later. 14. The method of claim 1, wherein the method comprises prioritizing between different repair methods. 15. The method of claim 14, wherein the method comprises first starting point-to-multipoint repair followed by point-to-point repair. 16. The method of claim 1, wherein the method comprises using an initiation point for repair sessions/signalling, said initiation point being selected from a group comprising: end of a session, object end, object threshold and end of a session group. 17. The method of claim 1, wherein the method comprises delaying sending of a repair request at the receiver. 18. The method of claim 1, wherein said repair request is delayed with a predetermined amount of time. 19. The method of claim 1, wherein a repair request is performed only when the need to consume the data at the receiver arises. 20. The method of claim 1, wherein a maximum repair availability time is provided. 21. The method of claim 19, wherein the method further comprises taking into account a position of a first loss in data stream. 22. The method of claim 1, wherein a recovery time is calculated and used in missing data repair. 23. The method of claim 1, wherein a separate repair session is requested and/or started before an initial multicast/broadcast transmission has ended. 24. The method of claim 1, wherein the method comprises calculating a repair request suppression time to wait before requesting repair. 25. A receiver device for data repair in a system capable of one-to-many transmission, the receiver device comprising: means for receiving data transmitted by a sender; and means for sender driven or receiver driven repair of missing data, concerning data missing at the receiver device. 26. A sender device for data repair in a system capable of one-to-many transmission, the sender device comprising: means for transmitting data to at least one receiver; and means for sender driven or receiver driven repair of missing data, concerning data missing at the receiver. 27. A system capable of one-to-many transmission, the system comprising a sender device, a network and at least one receiver device, the system comprising: means for transmitting data from said sender device, via said network, to said at least one receiver device; and means for providing sender driven or receiver driven repair of missing data, concerning data missing at the receiver device. 28. A software application executable in a receiver device for data repair in a system capable of one-to-many transmission, the software application comprising: program code for causing the receiver device to receive data transmitted by a sender; and program code for sender driven or receiver driven repair of missing data, concerning data missing at the receiver device. 29. A software application executable in a sender device for data repair in a system capable of one-to-many transmission, the software application comprising: program code for causing the sender device to transmit data to at least one receiver; and program code for sender driven or receiver driven repair of missing data, concerning data missing at the receiver. | FIELD OF THE INVENTION The invention generally relates to multicast and broadcast transmission technology and services, that is, services with at least one data source (or sender) and at least one receiver. BACKGROUND OF THE INVENTION For one-to-many (i.e., point-to-multipoint) services over systems such as IP multicast, IP datacasting (IPDC) and multimedia broadcast/multicast services (MBMS), file delivery (or discrete media delivery or file download) is an important service. Many of the features for delivering files over point-to-point protocols such as file transfer protocol (FTP) and hypertext transfer protocol (HTTP) are problematic for one-to-many scenarios. In particular, the reliable delivery of files—that is the guaranteed delivery of files—using similar one-to-one (i.e., point-to-point) acknowledgement (ACK) protocols such as transmission control protocol TCP is not feasible. The Reliable Multicast Transport (RMT) Working Group of the Internet Engineering Task Force (IETF) is in the process of standardizing two categories of error-resilient multicast transport protocols. In the first category, reliability is implemented through the use of (proactive) forward error correction (FEC), that is, by sending a certain amount of redundant data that can help a receiver in reconstructing erroneous data. In the second category, receiver feedback is used in order to implement reliable multicast transport. Asynchronous Layered Coding (ALC, RFC 3450) is a protocol instantiation belonging to the first category, while the NACK-Oriented Reliable Multicast (NORM) protocol presents an example of the second category. The details of ALC and NORM protocols are discussed in more detail in publications entitled “Asynchronous Layered Coding (ALC) Protocol Instantiation” (IETF RFC 3450) and “NACK-oriented Reliable Multicast Protocol” (Internet Draft) prepared by the Working Group of the IETF. The contents of these publications are fully incorporated herein by reference. Access networks on which these protocols can be used include, but are not limited to, wireless multiple-access networks such as radio access networks of the Universal Mobile Telecommunications Services (UMTS) system, wireless local area networks (WLAN), Digital Video Broadcasting—Terrestrial (DVB-T) networks and Digital Video Broadcasting—Satellite (DVB-S) networks. Briefly, ALC protocol is a proactive FEC based scheme that allows receivers to reconstruct mangled packets or packets that have not been received. ALC protocol uses FEC encoding on multiple channels, allowing the sender to send data at multiple rates (channels) to possibly heterogeneous receivers. Additionally, ALC protocol uses a congestion control mechanism to maintain different rates on different channels. ALC protocol is massively scalable in terms of the number of users because no uplink signalling is required. Therefore, any amount of additional receivers does not exactly put increased demand on the system. However, ALC protocol is not 100% reliable because reception is not guaranteed, thus it may be generally described as robust, rather than reliable. NORM, in turn, specifies the use of negative acknowledgement (NACK) messages in order to signal which packets of data (or otherwise defined “data blocks”) expected to arrive at the receiver were not received at the receiver (or were received incorrectly). In other words, receivers employ NACK messages to indicate loss or damage of transmitted packets to the sender. Accordingly, a receiver that “missed” some data blocks from a data transmission can send a NACK message to the sender requesting the sender to re-transmit the missed data block or blocks. NORM protocol also optionally allows for the use of packet-level FEC encoding for proactive robust transmissions. File Delivery over Unidirectional Transport (FLUTE) is a one-to-many transport protocol that builds on FEC (RFC 3452) and ALC building blocks. It is intended for file delivery from sender(s) to receiver(s) over unidirectional systems. It has specializations which make it suitable to wireless point-to-multipoint (multicast/broadcast) systems. The details of FLUTE protocol are discussed in more detail in the publication entitled “FLUTE—File Delivery over Unidirectional Transport” (Internet Draft) prepared by the above-mentioned Working Group of the IETF. The contents of this publication are fully incorporated herein by reference. NACK messages are not generally NORM specific, but they can also be used in connection with other protocols or systems, such as FLUTE. An ACK is a response message a receiver sends after receiving one or more data packets to acknowledge they were received correctly. A NACK is a response a receiver sends to the sender about packets that are/were expected to arrive, but have never been received. When in multicast or broadcast environment the data transmission occurs in a one-to-many fashion. If the transmission is not error free and different receivers are subject to different error rates (for example in MBMS users in different cells may experience different signal quality and, as a consequence, different error rate), there is the problem of providing increased data reliability. This can be achieved through the use of FEC and/or through the use of repair sessions. FEC provides a certain amount of redundancy to the transmitted data, in order to allow a certain degree of error resilience to enable a receiver to reconstruct the transmitted data. However, one problem of FEC is that it usually does not provide error free error recovery, or it provides full error recovery at the cost of a high use of data redundancy, which increases the channel bandwidth requirements. A repair session (between receiver and sender) can be employed to complement FEC (to reduce or eliminate the residual channel error rate), or can be used alone as the only method for error recovery. A repair session can occur over a point-to-point channel using a separate session. In this case, all the receivers that have missed some data during the multicast/broadcast transmission, send NACK requests to the sender to request the retransmission of the missing packets. However, if all the receivers miss at least one data packet, all the receivers will establish simultaneously point-to-point connections with the sender causing feedback implosion, i.e., congestion in the network (in uplink direction for the large number of NACKs and in downlink direction for the large number of concurrent retransmission and network connection requests) and overload of the sender. This situation is critical when considering for example thousands of users, like the case may be in MBMS networks. SUMMARY OF THE INVENTION Embodiments of the invention provide for scalable and efficient repair of broadcast/multicast (one-to-many) sessions. According to a first aspect of the invention, there is provided a method for data repair in a system capable of one-to-many transmission, the method comprising: transmitting data from a sender to at least one receiver; providing sender driven or receiver driven repair of missing data, concerning data missing at the receiver. The term “one-to-many transmission” is considered to mean in the context of the present application any transmission from at least one sender to more than one receiver. Accordingly, the term “one-to-many” here can be interpreted to mean “one-to-more than one”. The term “missing data” is considered to mean data not received at all at the receiver as well as data incorrectly received. According to a second aspect of the invention, there is provided a receiver device for data repair in a system capable of one-to-many transmission, the receiver device comprising: means for receiving data transmitted by a sender; and means for sender driven or receiver driven repair of missing data, concerning data missing at the receiver device. According to a third aspect of the invention, there is provided a sender device for data repair in a system capable of one-to-many transmission, the sender device comprising: means for transmitting data to at least one receiver; and means for sender driven or receiver driven repair of missing data, concerning data missing at the receiver. According to a fourth aspect of the invention, there is provided a system capable of one-to-many transmission, the system comprising a sender device, a network and at least one receiver device, the system comprising: means for transmitting data from said sender device, via said network, to said at least one receiver device; and means for providing sender driven or receiver driven repair of missing data, concerning data missing at the receiver device. According to a fifth aspect of the invention, there is provided a software application executable in a receiver device for data repair in a system capable of one-to-many transmission, the software application comprising: program code for causing the receiver device to receive data transmitted by a sender; and program code for sender driven or receiver driven repair of missing data, concerning data missing at the receiver device. According to a sixth aspect of the invention, there is provided a software application executable in a sender device for data repair in a system capable of one-to-many transmission, the software application comprising: program code for causing the sender device to transmit data to at least one receiver; and program code for sender driven or receiver driven repair of missing data, conceming data missing at the receiver. The software applications may be computer program products, comprising program code, stored on a medium, such as a memory. Dependent claims relate to embodiments of the invention. The subject matter contained in dependent claims relating to a particular aspect of the invention is also applicable to other aspects of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: FIG. 1A shows a one-to-many data transmission scenario in accordance with an embodiment of the invention; FIG. 1B shows different missing data repair methods in accordance with embodiments of the invention; FIG. 2A illustrates a simplified protocol architecture in accordance with an embodiment of the invention; FIG. 2B illustrates a simplified protocol architecture in accordance with another embodiment of the invention; FIG. 3 shows a system and details of a receiver device in accordance with an embodiment of the invention; FIG. 4 shows a sender device in accordance with an embodiment of the invention; and FIGS. 5-12 illustrate various embodiments of the invention. DETAILED DESCRIPTION The subject-matter contained in the introductory portion of this patent application may be used to support the detailed description. In the following the File Delivery over Unidirectional Transport (FLUTE) protocol is used as an example without an intention to limit the present invention to involve FLUTE only. Any other suitable protocol capable of one-to-many multicast or broadcast file delivery is also applicable here. US-patent application entitled “AN APPARATUS, SYSTEM, METHOD AND COMPUTER PROGRAM PRODUCT FOR RELIABLE MULTICAST TRANSPORT OF DATA PACKETS” (Ser. No. XX/XXX,XXX) filed on Dec. 24, 2003, having the same assignee as the present application presents methods for reliable multicast transport of data packets. The contents of that application are fully incorporated herein by reference. US-patent application entitled “IDENTIFICATION AND RE-TRANSMISSION OF MISSING PARTS” (Ser. No. XX/XXX,XXX) filed on Feb. 13, 2004, having the same assignee as the present application presents methods for identifying and re-transmitting missing data in a system capable of one-to-many transmission. Also the contents of that application are fully incorporated herein by reference. FIG. 1A shows a one-to-many data transmission scenario in accordance with an embodiment of the invention. The sender device 10 is a server, IP-based device, DVB device, GPRS (or UMTS) device or similar device that may use proactive forward error correction, such as an ALC mechanism and/or FEC mechanism, for sending multicast data blocks (or packets) to receiver devices 20 in a one-to-many fashion. Each receiving device 20 sends negative acknowledgement NACK messages (or requests) to the sender device 10 concerning missing blocks (blocks not received or received incorrectly). In response to NACK message(s), the sender device 10 generally re-transmits missing blocks to the receiver device 20 in a FLUTE session (the same session as the original FLUTE session established for original transmission, or a subsequent FLUTE session). Alternatively a session using another protocol than FLUTE may be used. In the context of the present application, a re-transmission session is called a repair session. Data is transferred from sender 10 to receiver(s) 20 as objects. For instance, a file, a JPEG image, a file slice are all objects. A session is established between the sender device 10 and the receiver device(s) 20 for file (or data) delivery. A single session may include the transmission of a single object or multiple objects. Different identifiers are used to identify the objects and sessions. Each data block has a number called source block number (SBN) or similar, which identifies each block. Blocks are represented by a set of encoding symbols. An encoding symbol identifier (ESI) or similar, in turn, indicates how the encoding symbols carried in the payload of a data packet (or block) were generated from the above-mentioned object (e.g., file). FIG. 1B shows different missing data repair methods in accordance with embodiments of the invention. Repair of missing data can be performed by using a point-to-point repair session established between the sender 10 and the receiver 20 or by using a point-to-multipoint session between the sender 10 and more than one receiver 20. In a repair session missing data in total or in part (depending on the case) is re-transmitted from the sender 10 to the receiver(s) 20 or the whole transmission can be repeated. Repair is effected from the original sender 10 or from a “third party server” or a repair server (or just simply a separate server (not shown)) which has a connection with the original server and is configured to buffer the transmission data/information. This server may, for example, be colocated with the original sender (e.g., an MBMS (Multimedia Broadcast/Multicast Service) server, also called BM-SC (Broadcast Multicast—Service Centre)), or, for example, be a separate server within an UMTS operator's network. Generally, in embodiments of the invention, FLUTE or a separate repair session with a method other than FLUTE, e.g., HTTP, SMS, FTP, SAP, GPRS, etc. with suitable underlying protocols can be used for missing data repair. FIG. 2A illustrates a simplified protocol architecture in accordance with an embodiment of the invention. According to this embodiment, the protocol stack to be implemented for the sender device 10 and the receiver device(s) 20 comprises an application layer, FLUTE protocol layer, UDP and IP layers and lower layers. FLUTE protocol layer is built on top of ALC protocol instantiation of the layered coding transport (LCT) building block (not shown). FEC building blocks (not shown) can be used. FLUTE protocol layer together with NACK messages is in—tended to provide reliable data block transmission from the sender device 10 to the receiver device 20. This protocol architecture can be used for one-to-many transmission (for both one-to-many “first transmissions” as well as one-to-many re-transmissions in a repair session). Alternatively, in an embodiment a TCP layer can be used instead of the UDP layer (see FIG. 2B). This applies for the case in which a separate point-to-point repair session (here: TCP session) is used for one-to-one (i.e., point-to-point) retransmissions. It has been observed that, in general, reliable multicast systems present the problem of requiring receiver-server control and data messaging which, due to the multiparty nature of multicast, presents scalability problems. There are three areas, in particular, which are of concern: a) limited radio bandwidth and activation resources, where the time to activate many radio channels, and the radio bandwidth that would take, makes it infeasible to allow many repairs to occur simultaneously; b) limited server capacity, where the server system, which is providing the “repair content” data, can handle limited numbers of requests (messaging) and associated session context data within a certain time window and a limited amount of simultaneous data transfer sessions; and c) limited end-to-end bandwidth, due to one or more bottlenecks in the overall system. Here the data rate, which could be made available to all the users requiring repair simultaneously, is, in many cases, insufficient to provide this service. Thus, a critical factor in increasing scalability under any or all of these limitations is to distribute the messaging in suitable time or avoid it entirely, if applicable. In the following, methods for efficient repair of a multicast/broadcast session are given. The methods are based on the sender decisions or based on the receiver decision. In the following discussion, with “sender” is denoted the data source or any other added or companion data source unit of a given multicast/broadcast network architecture (e.g., the Application Adjunct Entity, as defined in 3GPP TS 23.246 Rel. 6, V.6.1.0, sec. 7.1). Generally, the term “NACK” (Negative Acknowledgement) is used replaceably with “Repair Request” as the motivation for both is generally the same; however each of these methods can be used to NACK without the implicit request for repair in embodiments where objectives such as data gathering, rather than reliable delivery, are paramount. It is also to be noted that NACKing erroneous/missing data is generally a more efficient acknowledgement scheme for reliable multicast than positive acknowledgement schemes. However, this does not exclude the use of the described methods with positive ACK schemes where useful. A) Sender Driven Repair Methods Method A1: With this method, the sender transmits to the receivers an error rate parameter (for example the SDU error rate) during the session announcement (using for example a session description protocol, such as SDP, or any other means). (Other error rates in increments of bits, packets and other data units may be preferred in some embodiments.) The receivers interpret the received parameter as the error rate threshold beyond which the receivers should not request repair sessions using point-to-point sessions. If the sender has knowledge of the average receiver error rate and/or knowledge of the average percentage of receivers that receive erroneous data, it can determine, based on thresholds, to re-transmit the complete data stream in multicast/broadcast to all the users, avoiding receiver feedback implosion and a too high number of point-to-point connections that perform data repair. The means for the sender to know the average receiver error rate and the average percentage of receivers that receive erroneous data are for example given by network messages informing the sender of the quality or error rate (and/or the number of receivers) per cell, geographical area or receiver. An example of the preceding is as follows: The sender announces using SDP a broadcast/multicast session sending an error rate threshold of 10%. The broadcast/multicast session starts and the receiver finds out that data is received with an error rate >10%. Then it refrains from requesting the re-transmission of the missing packets via a point-to-point session. If the sender knows that the average receiver error rate is >10% and/or that the average percentage of receivers that receive erroneous data is >50% it may decide to re-transmit the complete data session in multicast/broadcast (10% and 50% are here example values). Alternatively, if the sender has knowledge of the average receiver error rate and/or the average percentage of receivers that receive erroneous data and the sender has determined that it is the case to re-transmit the entire data session (e.g., because of high average receiver error rate), the sender can decide to send a Point-to-multipoint repair token to the receivers at the end of the session, to announce that the session will—or alternatively “will not”—be re-transmitted in multicast/broadcast fashion (optionally listing the file(s) (and/or listing the block(s) of data within the file(s)) that will be repaired). This avoids the receivers to start point-to-point connections for performing data repair. The repair token is transmitted using any communication protocol at any of the layers 1-7 of the ISO OSI protocol stack, including via SDP in a separate “announcement” after the multicast/broadcast transmission. This can also be included in the last part (e.g., the very last packet) of a FLUTE file delivery within a multicast/broadcast transmission. Method A2: As described in section 7.1 of 3GPP TS 23.246 Rel. 6, V.6.1.0 for MBMS, in order to avoid network overload the sender can distribute the address of (one of many) Application Adjunct Entities (AAE) and parameters to generate a random time dispersion of the uplink traffic to the receivers at activation time. It is to be noted that although the specification states “one of many”, it can be understood to mean also “one or more of more than one”. Method A2 relies on the fact that the sender sends this information not at activation time Ooin), but at session announcement time (via SDP or any other suitable means). This method therefore defines two parameters to be delivered to the receivers during session announcement: AAE address or similar (the name of the parameter is exemplary); and random time. The random time can be computed, for example, on the basis of the knowledge the sender has about the location of the receivers. For example, if the sender knows that the receivers are distributed into different network cells of a cellular network (such as GPRS or UMTS), the sender will compute a random time in order to avoid all the receivers in the same cell to request a point-to-point repair at the same time (so, it will take into account the physical location). Instead, it will make sure the request for point-to-point connections are distributed along different cells in different time. If the sender has no information on the location of the receivers, then it will deliver to the receivers a random time parameter based only on the time (no physical location into account). The random time parameter indicates the start time of the point-to-point repair session. An extension to the prior art (3GPP TS 23.246 v. 6.1.0) and the method just described above is to provide a “NACK-supression parameter set” rather than just a “random time”. One case of this would be to implement an algorithm “NACK-alg-3, fast-window=500 seconds;uniform, slow-window=5000 seconds;normal, error_threshold_for_slow_window” where the algorithm defines the use of two time windows for NACK suppression—and time and statistical distribution parameters for each are given—and an input parameter to select between the use of the two (more explanation of this kind of NACK-suppression scheme is given below in connection with methods A4 and A5). Method A3: In another embodiment of the invention the sender, after reception of a certain number of NACK requests from the receivers may decide, based on its own thresholds, to close the point-to-point connections and re-transmit the entire (or part of the) session in multicast/broadcast. This happens if the sender understands that the receivers have made too many re-transmission requests (i.e., there is a higher error rate), and it is better to avoid wasting network resources using point-to-point connections. The threshold may be statically configured, e.g., 4 different receiver NACKs for a session, or dynamically calculated, e.g. it can be extrapolated from historical data that, e.g., 2 NACKs from different receivers within 3 seconds for a football-video service indicates that 5000 NACKs can be expected within 10 minutes. In the case that the sender has chosen to close point-to-point repair data delivery, and re-deliver the data using point-to-multipoint but not immediately, an embodiment would have the sender signal to the receivers that the repair session will occur in the future, and thus inform receivers which have not yet NACKed their missing data that they do not need to. Furthermore, this signalling to receivers may indicate exactly which fragments of data are to be resent, and thus enable receivers to establish the extent to which their content will be complete—and need for subsequent (point-to-point) repair thereafter. This enables a mixed point-to-multipoint & point-to-point repair. FIG. 5 illustrates the embodiment of using Repair Token to Indicate P-t-M (Point-to-Multipoint) repair at a later time and subsequently using P-t-P (Point-to-Point) for tokens missing from P-to-M repair data. Repair token may be P-t-M or P-t-P in which cases it originates from Sender (Y) and Repair Sender (Z), respectively. The P-t-P or P-t-M decision maker (X) may be a distinct entity, or combined with Sender (Y) or Repair Server (Z). The P-t-P or P-t-M decision maker (X) may be a third entity, which may be embodied as a single or separate logical and/or physical device. The Repair Sender in FIG. 5 (an in other Figures) can be understood to be a repair server or similar. The P-t-P or P-t-M decision maker (or decision making unit) may also be called a repair decision unit. Method A4: As described in Method A1, a receiver should not request a retransmit (send a NACK) when the threshold(s) is reached. Another embodiment is to change the context of a receiver either by: a) changing the NACK-suppression algorithm or its parameters; and/or b) changing the mode of operation. The “should not NACK” (or must not NACK) mentioned above presents an extreme case of changing the NACK-suppression algorithm. Another alternative is to change the behaviour in such way that if error rate below the threshold then “uniformly randomise the NACK(s) over a time period X, starting from the end of the initial delivery session” else “must wait until after a certain time Y after the initial session ends, and then randomise the NACK(s) over a time period Z”. X, Y, Z can be chosen to be different or even equal values. This is particularly useful in enabling a “quick repair plus slow repair” to maximise perceived user QoS. Users who's receivers got many errors in initial delivery are likely to experience worse QoS in any case—if they wish to consume the content immediately after delivery, they will have a potentially long repair session to wait for anyway. However, users who got very few errors are thus given priority in “repair resources”, and so they should be able to quickly use the content after the initial session. Thus, this method enables even poor initial deliveries to complete, while ensuring that good initial deliveries are completed by repair at good user perceived QoS levels. A generalization of the above is a method that uses an array of error rates [ER1, ER2, . . . , ERn], an array of NACK(s) randomizations [X1, X2, . . . , Xn], an array of waiting times [Y1, Y2, . . . , Yn] and an array or NACK(s) randomizations [Z1, Z2, . . . , Zn], where for each k=1, . . . , n, n in N+, the 4-tuple (ERk, Xk, Yk, Zk) indicates that for an error rate <ERk, the receiver must uniformly randomize the NACK(s) over a time period Xk, and for and error rate >=ERk, the receiver must wait until after a certain time Yk after the initial session ends, and then randomize the NACK(s) over a time period Zk. The array of waiting times may be a zero-values array. Some NACK suppression schemes allocate more than one role to receivers/hosts. For instance, a flag-holder scheme expects the flag-holder(s) to respond immediately to errors and other receivers to NACK (randomly), if they do not become aware that the flag-holder(s) NACKed already (similar to IMGP for reporting group membership). An embodiment of the present invention would be to change the mode of operation of a receiver. For instance, if a threshold were exceeded (or alternatively not reached) then the receiver would adopt another role. In the flag-holder example, a receiver under a very low threshold (e.g., with only one error) might NACK immediately or within a very short time window, and other receivers would NACK later. A combinatory embodiment would associate “receiver roles” with NACK-suppression algorithm/parameters such that a certain role (e.g., “low error mode” or “high error mode”) defines the operation of NACKs, and the threshold is used to calculate the mode, which should be used. It may be advantageous to also in—clude hysteresis with these kinds of decision processes, so that the mode may be changed after a number of consecutive measurements—e.g., if a receiver exceeds the threshold only one in 100 measurements, it may not change mode. FIG. 6 illustrates distribution of Back-off times. FIG. 7 shows that for all receivers that experience error rate below Threshold 1 (that is, receivers 1 and 2), the requests are distributed over 60 sec after the start of the session. For receivers that experience error rate higher than Threshold 1 but smaller than Threshold 2 (that is, receivers 3, 5 & 8), the request is sent 60 seconds later and distributed over 120 seconds. Method A5: As described in Method A1, an error rate threshold may be used. Another embodiment provides this and also a time and/or data window in which to calculate the threshold. For example, “10% packet error rate; any, 30 seconds window, sliding” could indicate that the threshold is 10% of packets (missing or contain errors) within the last 30 seconds and to sample from the last 30 seconds continuously (or pseudo-continuously) with a sliding time window. Another example would be “5% bit error rate, any, 2 Kbyte window, blocked” so that the threshold is 5% of bits are erroneous for one or more (any) 2 Kbyte block, where 0-2 KB, 2-4 KB, 4-6 KB, etc. are the blocks sampled. Any data matching the criteria is an embodiment; however in large data transfers it may be advantageous to provide a second level threshold instead, such as “consider threshold reached, if this criteria is met 3 times within a session”. FIG. 8 illustrates the effect of time window for calculation of threshold values. Method A6: Some embodiments may share/deliver the parameters discussed between server and receiver by pre-configuring. For example, such as saving to a SIM card by the operator, which issues the SIM and operates the Multicast system. Another example is to have well known parameters pre-configured, and usually such well known figures would be specified in a standard or maintained by a numbers registry organisation (such as IANA). In an embodiment, the default values of these parameters are pre-configured and are superseded (overwritten) for a certain session if another method to deliver the parameters is also provided. Method A7: A further embodiment of the invention shall, after receiving a repair request from a receiver for a significantly large amount of content data, have the sender indicate to the receiver that is will “repair this later”. The subsequent repair session may be a point-to-point or point-to-multipoint session. Thus, where system bandwidth is the predominant limiting scalability factor, this allows a sender to take care of receivers that can be satisfied quickly first, and in so doing reduce the average time to ensure than a target number of receivers (e.g., 99%) have complete (error free) data. For example, the repair may be started by point-to-multipoint repair first (to repair the largest number of receivers), and then followed by point-to-point repairs (to repair a minor number of receivers). Method A8: The above generally used the end-of-session as the initiation point for repair sessions and signalling. However, in some embodiments the use of object (e.g., file or scene) end, threshold (e.g., every 1 Mbyte of data or every 1000 packets or every 5 minutes) or session group (e.g., the end of all of these 4 related sessions) may be advantageous. FIG. 9 illustrates the start of repair session after end of object detected. B) Receiver Driven Repair Methods Generally, a receiver can delay the request of point-to-point connection establishment for data repair of a certain amount of time, avoiding to perform this request right after the end of the multicast/broadcast session. This avoids the situation in which a larger number of receivers send requests of point-to-point connections for repair simultaneously, and therefore congestion of the network and sender. In the following, some methods of delaying the point-to-point repair request are given: Method B1: The repair can be a lazy repair: in this case, the receiver performs the point-to-point repair request when the user wants to consume the data (e.g., when the user wants to play the video clip that has been downloaded during a multicast/broadcast session). This requires that the user waits for the time it takes to perform the complete point-to-point repair (i.e., it increases the user latency for data fruition). This method optionally requires also that the sender transmits in the session announcement (using SDP or any other suitable mean) the maximum repair availability time, that is the time limit until the sender is able to perform successfully the point-to-point repair. The format of this time unit is not specified, but it can be expressed in a variety of ways (for example, but not restricted to, absolute time, or relative time). After the maximum repair availability time, the point-point repair operation is not guaranteed to succeed. This gives a time limit to the sender to keep data stored to perform data repair. If the point-to-point repair has not been performed by the maximum repair availability time (because the user has not requested the data playback yet), then the receiver is forced to perform the point-to-point repair at that time. If the receiver is switched off, and the maximum repair availability time elapses, then the point-to-point repair at a successive time is not guaranteed. In some cases. It is advantageous to reduce the period over which NACKs are randomised to allow a “safety margin” at the end; for instance, if the period is 432000 seconds, NACKs are generally distributed over 400000 seconds allowing a maximum of 32000 for “deactivated” receivers to be powered up without missing the guaranteed repair time. An example of the preceding is as follows: If the sender sends in its announcement that the maximum repair availability time is until 15 Mar. 2004 17:00, it means that the receivers can perform repair until that date and time specified. After that date/time, the repair operation is not guaranteed. An alternative way could be to express the time as relative time from the multicast/broadcast transmission. For example the sender may signal to the receivers that the maximum repair availability time is 432000 seconds. This tells the receiver that the last possibility to make a point-to-point repair is after 5 days from the multicast/broadcast transmission. FIG. 10 illustrates the embodiment of lazy repair. Method B2: The repair can be a lazy playback repair: in this case the receiver performs the point-to-point repair request when the user wants to consume the data. In addition, the repair takes into account the position of the first loss in the data stream. If the stream is a speech or audio and video stream, the receiver can compute exactly at what media unit time the first data loss occur. The point-to-point repair can then be deferred to start even after playback of the data stream start, in the best case, but it must be performed and completed early enough in such way that the receiver playback is not subject to continuity disruption. If the point-to-point repair operation cannot be performed concurrently to the playback (because the point-to-point repair operation would require a time larger than the time-to-the-first-missing block), then the point-to-point repair can be started immediately when the user issues the playback request, but the actual playback is delayed by the necessary time in order to avoid playback disruption. This scheme is very similar to the first scheme (Method B1) above, but it offers a lower user latency because the repair operation and the playback are temporally partially overlapping. Also in this case, the maximum repair availability time information could be optionally required and used by the receiver as in the first case (Method B 1). The time required to perform the point-to-point repair can be estimated by the receiver based on factors like the measured or granted bandwidth of the point-to-point connection, the measured Round Trip Time over the point-to-point channel, and the point-to-point session establishment and termination delay. An example of the preceding is as follows: If the sender transmits a 5 min audio/video clip and the receiver detects that there are 30 missing packets, the earliest of which occurs at time 4′, then the user can start playback of the stream immediately, and the receiver will start the point-to-point repair operation concurrently with the user playback early enough so that all the 30 missing packets arrive before 4 minutes of playback. If the 30 missing blocks are such that the first missing block occurs at time 1′, and the receiver estimates that the point-to-point repair session will take more than one minute, then the repair session is started and the playback is delayed a time necessary to avoid playback disruption. FIG. 11 illustrates the embodiment of lazy playback repair. Method B3: Another case (analogous to the receiver-driven application of method A7) is that the NACK-suppression uses the quantity of erroneous/missing data as a multiplier to calculate the recovery time. For example, if a sender indicates a “unit of time” is 60 seconds, and that a unit of lost data is 10 packets, a receiver with 56 lost packets would calculate a time of INT(56/10)*60=300 seconds. These resulting times may be used as an offset (do not start NACKing before this many seconds have elapsed after the initial session ends) and/or as the period to distribute the NACKs over (e.g. randomise your NACK uniformly over this time). Method B4: A further embodiment of the invention is the possibility of starting the point-to-point repair session before the initial multicast/broadcast transmission has ended. In this way the repair is faster and the user can start the error-free “play” session with a shorter latency. The exact repair start time can be decided by the receiver, or it can be a function of the location of the first error within the data stream and/or the length of the file. FIG. 12 illustrates the embodiment of repair started due to “early detection”. All the methods described above can also be used in any possible and functionally suitable combination. FIG. 3 shows a system and details of a receiver device 20 in accordance with an embodiment of the invention. The system comprises the sender device 10 a transmission network 30, e.g., an IP network or another fixed network, a wireless network or a combination of a fixed and a wireless (cellular) network etc., and the receiver device 20. The receiver device 20 can be a cellular telephone, a satellite telephone, a personal digital assistant or a Bluetooth device, WLAN device, DVB device, or other similar wireless device. The device 20 includes an internal memory 21, a processor 22, an operating system 23, application programs 24, a network interface 25 and a NACK & repair mechanism 26. The internal memory 21 accommodates the processor 22, operating system 23 and application programs 24. The NACK & repair mechanism 26 enables the NACKing and repair procedures in response to missing or mangled data in a data transmission. The device 20 is able to communicate with the sender device 10 and other devices via the network interface 25 and the network 30. FIG. 4 shows a sender device 10 in accordance with an embodiment of the invention. The sender device 10 can be, for example, a network server or any suitable device intended for file (or media) delivery. The device 10 includes an internal memory 11, a processor 12, an operating system 13, application programs 14, a network interface 15, a transmission & repair mechanism 16 and a data storage 17. The internal memory 11 accommodates the processor 12, operating system 13 and application programs 14. The transmission & repair mechanism 16 enables the transmission of data packets to receiver device(s) 20. Furthermore, it enables re-transmission of data packets in repair sessions. Data to be sent to receiver devices 20 and data to be re-transmitted can be stored in the data storage 17. Alternatively, data can be stored in a separate device co-located with or outside of the sender device 10. The device 10 is able to communicate with the receiver device 20 and other devices via the network interface 15 and the network 30. Procedures relating to repair of missing data can be implemented by software. A computer program product comprising program code stored in the receiver device 20 and run in the processor 22 can be used to implement the procedures at the receiving end of the transmission session, whereas a computer program product comprising program code stored in the sender device 10 and run in the processor 12 can be used to implement the procedures at the transmitting end. Embodiments of the invention have been illustrated with examples of logical sender/server entities and receiver units. The use of a third entity going between for repair requests, and repair responses (if appropriate), also falls within the scope of embodiments of the invention. Such an entity may provide firewall, proxy and/or authorization services, for instance to authorize a repair sender message to a point-to-multipoint sender asking it to deliver a repair token; or to act as a repair request aggregator/proxy for messages from recievers to sender and thus enable a transparent point-to-point/point-to-multipoint decision in a third device. The use of point-to-multipoint delivery of repair tokens has been presented in the preceding. Additionally, the use of point-to-point repair tokens may be advantageous in some embodiments and is within the scope of embodiments of the in—vention (a method of delivery/format corresponding to what has been presented relating to point-to-multipoint repair tokens can be used, e.g., SDP). Such a scheme may indicate to a receiver that point-to-multipoint repair/resend data is “on its way” if a point-to-point request has arrived after the decision to resend by point-to-multipoint has been made, or alternatively to enable a receiver to deactivate its multipoint reception for a time, for power saving, but still learn of a forthcoming point-to-multipoint repair_response/resend. With embodiments of the invention NACK suppression is enabled to provide scalable reliable multicast. An efficient and scalable point-to-point repair for multicast/broadcast transmissions is provided, avoiding feedback implosion and network/sender overload. Particular implementations and embodiments of the invention have been described. It is clear to a person skilled in the art that the invention is not restricted to details of the embodiments presented above. Furthermore, one skilled in the art will be aware that there are many additional ways to embody this invention, which are within the scope of this invention, even though not shown in one of the limited subset of examples. Especially, the invention should not be limited to any specific names of any protocols, parametres or messages. The invention can be implemented in other embodiments using equivalent means without deviating from the characteristics of the invention. The scope of the invention is only restricted by the attached patent claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>For one-to-many (i.e., point-to-multipoint) services over systems such as IP multicast, IP datacasting (IPDC) and multimedia broadcast/multicast services (MBMS), file delivery (or discrete media delivery or file download) is an important service. Many of the features for delivering files over point-to-point protocols such as file transfer protocol (FTP) and hypertext transfer protocol (HTTP) are problematic for one-to-many scenarios. In particular, the reliable delivery of files—that is the guaranteed delivery of files—using similar one-to-one (i.e., point-to-point) acknowledgement (ACK) protocols such as transmission control protocol TCP is not feasible. The Reliable Multicast Transport (RMT) Working Group of the Internet Engineering Task Force (IETF) is in the process of standardizing two categories of error-resilient multicast transport protocols. In the first category, reliability is implemented through the use of (proactive) forward error correction (FEC), that is, by sending a certain amount of redundant data that can help a receiver in reconstructing erroneous data. In the second category, receiver feedback is used in order to implement reliable multicast transport. Asynchronous Layered Coding (ALC, RFC 3450) is a protocol instantiation belonging to the first category, while the NACK-Oriented Reliable Multicast (NORM) protocol presents an example of the second category. The details of ALC and NORM protocols are discussed in more detail in publications entitled “Asynchronous Layered Coding (ALC) Protocol Instantiation” (IETF RFC 3450) and “NACK-oriented Reliable Multicast Protocol” (Internet Draft) prepared by the Working Group of the IETF. The contents of these publications are fully incorporated herein by reference. Access networks on which these protocols can be used include, but are not limited to, wireless multiple-access networks such as radio access networks of the Universal Mobile Telecommunications Services (UMTS) system, wireless local area networks (WLAN), Digital Video Broadcasting—Terrestrial (DVB-T) networks and Digital Video Broadcasting—Satellite (DVB-S) networks. Briefly, ALC protocol is a proactive FEC based scheme that allows receivers to reconstruct mangled packets or packets that have not been received. ALC protocol uses FEC encoding on multiple channels, allowing the sender to send data at multiple rates (channels) to possibly heterogeneous receivers. Additionally, ALC protocol uses a congestion control mechanism to maintain different rates on different channels. ALC protocol is massively scalable in terms of the number of users because no uplink signalling is required. Therefore, any amount of additional receivers does not exactly put increased demand on the system. However, ALC protocol is not 100% reliable because reception is not guaranteed, thus it may be generally described as robust, rather than reliable. NORM, in turn, specifies the use of negative acknowledgement (NACK) messages in order to signal which packets of data (or otherwise defined “data blocks”) expected to arrive at the receiver were not received at the receiver (or were received incorrectly). In other words, receivers employ NACK messages to indicate loss or damage of transmitted packets to the sender. Accordingly, a receiver that “missed” some data blocks from a data transmission can send a NACK message to the sender requesting the sender to re-transmit the missed data block or blocks. NORM protocol also optionally allows for the use of packet-level FEC encoding for proactive robust transmissions. File Delivery over Unidirectional Transport (FLUTE) is a one-to-many transport protocol that builds on FEC (RFC 3452) and ALC building blocks. It is intended for file delivery from sender(s) to receiver(s) over unidirectional systems. It has specializations which make it suitable to wireless point-to-multipoint (multicast/broadcast) systems. The details of FLUTE protocol are discussed in more detail in the publication entitled “FLUTE—File Delivery over Unidirectional Transport” (Internet Draft) prepared by the above-mentioned Working Group of the IETF. The contents of this publication are fully incorporated herein by reference. NACK messages are not generally NORM specific, but they can also be used in connection with other protocols or systems, such as FLUTE. An ACK is a response message a receiver sends after receiving one or more data packets to acknowledge they were received correctly. A NACK is a response a receiver sends to the sender about packets that are/were expected to arrive, but have never been received. When in multicast or broadcast environment the data transmission occurs in a one-to-many fashion. If the transmission is not error free and different receivers are subject to different error rates (for example in MBMS users in different cells may experience different signal quality and, as a consequence, different error rate), there is the problem of providing increased data reliability. This can be achieved through the use of FEC and/or through the use of repair sessions. FEC provides a certain amount of redundancy to the transmitted data, in order to allow a certain degree of error resilience to enable a receiver to reconstruct the transmitted data. However, one problem of FEC is that it usually does not provide error free error recovery, or it provides full error recovery at the cost of a high use of data redundancy, which increases the channel bandwidth requirements. A repair session (between receiver and sender) can be employed to complement FEC (to reduce or eliminate the residual channel error rate), or can be used alone as the only method for error recovery. A repair session can occur over a point-to-point channel using a separate session. In this case, all the receivers that have missed some data during the multicast/broadcast transmission, send NACK requests to the sender to request the retransmission of the missing packets. However, if all the receivers miss at least one data packet, all the receivers will establish simultaneously point-to-point connections with the sender causing feedback implosion, i.e., congestion in the network (in uplink direction for the large number of NACKs and in downlink direction for the large number of concurrent retransmission and network connection requests) and overload of the sender. This situation is critical when considering for example thousands of users, like the case may be in MBMS networks. | <SOH> SUMMARY OF THE INVENTION <EOH>Embodiments of the invention provide for scalable and efficient repair of broadcast/multicast (one-to-many) sessions. According to a first aspect of the invention, there is provided a method for data repair in a system capable of one-to-many transmission, the method comprising: transmitting data from a sender to at least one receiver; providing sender driven or receiver driven repair of missing data, concerning data missing at the receiver. The term “one-to-many transmission” is considered to mean in the context of the present application any transmission from at least one sender to more than one receiver. Accordingly, the term “one-to-many” here can be interpreted to mean “one-to-more than one”. The term “missing data” is considered to mean data not received at all at the receiver as well as data incorrectly received. According to a second aspect of the invention, there is provided a receiver device for data repair in a system capable of one-to-many transmission, the receiver device comprising: means for receiving data transmitted by a sender; and means for sender driven or receiver driven repair of missing data, concerning data missing at the receiver device. According to a third aspect of the invention, there is provided a sender device for data repair in a system capable of one-to-many transmission, the sender device comprising: means for transmitting data to at least one receiver; and means for sender driven or receiver driven repair of missing data, concerning data missing at the receiver. According to a fourth aspect of the invention, there is provided a system capable of one-to-many transmission, the system comprising a sender device, a network and at least one receiver device, the system comprising: means for transmitting data from said sender device, via said network, to said at least one receiver device; and means for providing sender driven or receiver driven repair of missing data, concerning data missing at the receiver device. According to a fifth aspect of the invention, there is provided a software application executable in a receiver device for data repair in a system capable of one-to-many transmission, the software application comprising: program code for causing the receiver device to receive data transmitted by a sender; and program code for sender driven or receiver driven repair of missing data, concerning data missing at the receiver device. According to a sixth aspect of the invention, there is provided a software application executable in a sender device for data repair in a system capable of one-to-many transmission, the software application comprising: program code for causing the sender device to transmit data to at least one receiver; and program code for sender driven or receiver driven repair of missing data, conceming data missing at the receiver. The software applications may be computer program products, comprising program code, stored on a medium, such as a memory. Dependent claims relate to embodiments of the invention. The subject matter contained in dependent claims relating to a particular aspect of the invention is also applicable to other aspects of the invention. | 20040218 | 20071113 | 20050818 | 61543.0 | 0 | CHASE, SHELLY A | DATA REPAIR | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,782,492 | ACCEPTED | Method and apparatus for monitoring power quality in an electric power distribution system | A composite power quality indication generated from user weighted statistical contributions of selected system parameters provides an overall indication of power quality in an electric power distribution system. The user defined weightings are maintained over time by continually updating sensitivities that normalize the component contributions to the composite power quality indication. The current composite power quality indication is displayed in relation to its long-term mean and to dynamic thresholds determined as multiples of the standard deviation of the long-term mean. | 1. A method of monitoring power quality in an electric power distribution system comprising: repetitively determining values of a plurality of selected parameters of the electric power distribution system; generating a composite power quality indicator from the values of the plurality of selected parameters; and generating an output representing the composite power quality indicator. 2. The method of claim 1, wherein generating the composite power quality indicator comprises performing statistical analysis of the values of the plurality of selected parameters. 3. The method of claim 1, wherein generating the composite power quality indicator comprises generating a power quality component for each of the plurality of selected parameters and combining the power quality components to produce the composite power quality indicator. 4. The method of claim 3, wherein combining the power quality components to produce the composite power quality indicator comprises assigning each power quality component an associated weighting factor selected to produce a selected weighting of the power quality component, multiplying each power quality component by its associated weighting factor to generate the power quality component and adding the weighted power quality components to generate the power quality index. 5. The method of claim 4, wherein combining the power quality components further comprises maintaining the selected weighting by establishing a power quality component sensitivity for each of the plurality of selected parameters and multiplying the power quality component by the power quality component sensitivity and the associated weighting factor. 6. The method of claim 5, wherein establishing each power quality component sensitivity comprises maintaining a long-term mean value for each power quality component and a long-term mean value for the composite power quality indicator, and multiplying the associated weighting factor by a ratio of the composite power quality indicator long-term mean value to the power quality component long-term mean value. 7. The method of claim 6, wherein establishing the power quality component sensitivity comprises updating each power quality component sensitivity by multiplying a most recent power quality component sensitivity by the associated weighting factor and the ratio of the composite power quality indicator long-term mean to the power quality component long-term mean. 8. The method of claim 7, wherein generating the composite power quality indicator further comprises generating at least one dynamic threshold for the composite quality indicator by generating a standard deviation of the long-term mean of the composite power quality indicator and generating the at least one dynamic threshold as a function of the standard deviation, and generating the output comprises generating a representation of the composite power quality indicator relative to the long-term mean of the composite power quality indicator and relative to the at least one dynamic threshold. 9. The method of claim 1, wherein generating the composite power quality indicator further comprises generating at least one dynamic threshold for the composite power quality indicator and wherein generating the output comprises generating a representation of the composite power quality indicator relative to the at least one dynamic threshold. 10. The method of claim 9, wherein generating the at least one dynamic threshold comprises generating a long-term mean of the composite power quality indicator, generating a standard deviation of the long-term mean of the composite power quality indicator and generating the at least one dynamic threshold as a function of the standard deviation, and generating the output comprises generating a representation of the composite power quality indicator relative to the long-term mean of the composite power quality indicator as well as relative to the at least one dynamic threshold. 11. The method of claim 10, wherein generating the long-term mean of a composite power quality indicator comprises generating a moving average of the composite power quality indicator over a selected time period. 12. The method of claim 11, wherein generating the composite power quality indicator over the selected time period comprises generating a first moving average of the composite power quality indicator over a first time period and generating a second moving average of the composite power quality indicator over a second time period which is a multiple of the first time period, and generating the composite power quality indicator using only the first moving average until the method has been employed for the second time period and thereafter generating the composite quality indicator using the second moving average. 13. The method of claim 12, wherein the first time period is about one week and the second time period is about one year. 14. A power quality monitor for an electric power distribution system comprising: sensors for sensing currents and voltages in the electric power distribution system; processing means comprising means for repetitively determining values of selected parameters from the currents and voltages and for statistically generating a composite power quality indicator from the values of the selected parameters; and output means providing a representation of the composite power quality indicator. 15. The monitor of claim 14, wherein the processing means comprises means generating power quality components from the values of the selected parameters and combining the power quality components to generate the composite power quality indicator. 16. The monitor of claim 14, wherein the process means comprises means generating a long-term mean of the composite power quality indicator and the output means comprises a display displaying the composite power quality indicator relative to the long-term mean of the composite power quality indicator. 17. The monitor of claim 16, wherein the processing means further comprises means generating a standard deviation of the long-term mean of the composite power quality indicator and at least one dynamic threshold as a function of the standard deviation, and the display further displays the composite power quality indicator relative to the at least one dynamic threshold. 18. The monitor of claim 17, wherein the processing means comprises means generating a first dynamic threshold as a first function of the standard deviation and a second dynamic threshold as a second function of the standard deviation that is greater in value than the first function of the standard deviation, and wherein the display displays the first and second dynamic thresholds relative to the long-term mean of the composite power quality indicator to define a safe zone for the composite power quality indicator between the long-term mean of the power quality indicator and the first dynamic threshold, a caution zone between the first and second dynamic thresholds, and an alert zone farther from the long-term mean of the composite power quality indicator than the second dynamic threshold. 19. The monitor of claim 18, wherein the processing means comprises means generating power quality components from values of the selected parameters, means providing a selected weighting of each power quality component by applying a selected weighting factor to that power quality component to generate weighted power quality components, and means combining the weighted power quality components to generate the composite power quality indicator. 20. The monitor of claim 19, wherein the processing means further comprises means maintaining the weighting of each power quality component by applying a continually adjusted sensitivity to each weighted power quality component derived from the long-term mean of the composite power quality indicator and a long-term mean of the power quality component. | BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a system and method for monitoring the performance of an electric power distribution system, and as one aspect, to the generation and presentation of a composite power quality indicator generated from user weighted statistical contributions of various system parameters. 2. Background Information Various techniques have been employed for monitoring the performance of electric power distribution systems. State-of-the-art monitors calculate various electrical parameters such as RMS currents and voltages, peak currents and voltages, power, energy, power factor and the like. Waveform analyzers are used for oscillographic analysis of system waveforms. Numerous methods have been developed to measure and capture power quality events, such as current and voltage sags and swells, voltage surges and excessive harmonic distortion and flicker. However, the state-of-the-art power quality meters lack a means for telling the user whether the existing power quality is normal. For example, such meters will display and record values and minimum and maximum extremes. Nevertheless, until there is a triggered event, the user still does not know whether conditions are normal. Furthermore, attempts to predefine acceptable power quality levels fail to acknowledge unique attributes of a particular electrical system. In one known system, the triggers dynamically adjust to fill available hard disk space within a preprogrammed time period. However, the user still does not know whether the present values of the monitored parameters are normal. In addition, at present, there is no overall indication of power quality. Each parameter is evaluated separately. SUMMARY OF THE INVENTION The invention is directed to a system and method of monitoring power quality in an electric power distribution system that generates a composite power quality indicator that is a function of a plurality of system parameters. Each component of the indicator is weighted by a user programmable factor to emphasize or de-emphasize its affect. The composite power quality indicator is updated from statistics generated during a sampling period. As part of each update, each component of the composite power quality indicator is normalized by a sensitivity to a preset threshold before multiplication by the user assigned weighting factor. After multiplication, the results accumulate until they are totaled at the end of the sampling period. During the update, the sensitivity is adjusted to maintain the user selected weighting of the components. More particularly, the method in accordance with one aspect of the invention is directed to repetitively determining the values of a plurality of selected parameters of the electric power distribution system, generating a composite power quality indicator from the values of the plurality of selected parameters and generating an output representing the composite power quality indicator. Generation of the composite power quality indicator can comprise performing a statistical analysis of the values of the plurality of selected parameters. The values of the plurality of selected parameters can be determined by generating samples of each of the plurality of selected parameters over a sampling period and determining the values from the samples generated during the sampling period. As another aspect of the invention, the composite power quality indicator is generated by generating a power quality component for each of the plurality of selected parameters and combining the power quality components to produce the composite power quality indicator. Combining the power quality components can comprise assigning an associated weighting factor to each power quality component selected to produce a selected weighting of that power quality component, multiplying each power quality component by its associated weighting factor to generate a weighted power quality component and adding the weighted power quality components to generate the composite power quality indicator. Preferably, the selected weighting of each of the power quality components is maintained by determining an associated power quality component sensitivity and multiplying the power quality component by its power quality component sensitivity as well as the associated weighting factor. Each power quality sensitivity can be determined by maintaining a long-term mean value for each power quality component and a long-term mean value for the composite power quality indicator and multiplying the associated weighting factor by a ratio of the composite power quality indicator long-term mean to the power quality component long-term mean. Each power quality component sensitivity can be updated by multiplying the most recent power quality component sensitivity by the associated weighting factor and a ratio of the composite power quality indicator long-term mean to the power quality component long-term mean. In accordance with another aspect of the invention, the composite power quality indicator is further generated by generating at least one dynamic threshold for the composite power quality indicator and generating the output includes generating a representation of the composite power quality indicator relative to the at least one dynamic threshold. The at least one dynamic threshold can be generated by generating a long-term mean of the composite power quality indicator, generating a standard deviation of the long-term mean and generating the at least one dynamic threshold as a function of the standard deviation. In this case, the output step further comprises generating a representation of the composite power quality indicator relative to its long-term mean and to the at least one dynamic threshold. The long-term mean of the composite power quality indicator can be generated as a moving average over a selected time. The generation of the composite power quality indicator over the selected time period can comprise generating a first moving average over a first time period and generating a second moving average over a second time period which is a multiple of the first time period. The composite power quality indicator is generated using only the first moving average until the method has been used for at least the second time period and then the composite power quality indicator is generated using the second moving average. In the exemplary embodiments of the invention, the first time period is one week and the second time period is one year. As another aspect of the invention, a power quality monitor for an electric power distribution system comprises sensors for sensing current and voltages in the electric power distribution system, processing means comprising means for repetitively determining values of selected parameters from the currents and voltages and for statistically generating a composite power quality indicator from the values of the selected parameters, and output means providing a representation of the composite power quality indicator. The processing means can comprise means generating power quality components from the values of the selected parameters and combining the power quality components to generate the composite power quality indicator. The processing means can also comprise means generating a long-term mean of the composite power quality indicator and the output means can comprise a display displaying the composite power quality indicator relative to the long-term mean of the composite power quality indicator. In addition, the processing means can comprise means generating a long-term mean of the composite power quality indicator, a standard deviation of the long-term of the composite power quality indicator and at least one dynamic threshold as a function of the standard deviation, and the output means can comprise a display displaying the composite power quality indicator relative to the long-term mean of the composite power quality indicator and relative to the at least one dynamic threshold. In a preferred form, the process means can comprise means generating a first dynamic threshold as a first function of the standard deviation and a second dynamic threshold as a second function of the standard deviation greater than the first function of the standard deviation, and wherein the display displays the first and second dynamic thresholds relative to the long-term mean to define a safe zone for the composite power quality indicator between the long-term mean and the first dynamic threshold, a caution zone between the first and second dynamic threshold and an alert zone farther from the long-term mean than the second dynamic threshold. Also, the processing means can comprise means generating the power quality components from values of the selected parameters, means providing a selected weighting of each power quality component by applying a selected weighting factor to that power quality component to generate weighted power quality components and means combining the weighted power quality components to generate the composite power quality indicator. The processing means can further comprise means maintaining the weighting of each power quality component by applying a continually adjusted sensitivity to each weighed power quality component derived from the long-term mean of the composite power quality indicator and a long-term mean of the power quality component. BRIEF DESCRIPTION OF THE DRAWINGS A full understanding of the invention can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which: FIG. 1 is a schematic diagram of a power quality monitor in accordance with the invention. FIG. 2 is CBEMA curve of ITI classifying voltage sags and swells by duration and severity of change in the rms voltage level. FIG. 3 is a flow chart showing operation of the power quality monitor of FIG. 1. DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention is directed to a method and a monitor that provides an overall indication of power quality in an electric power distribution system based upon what is normal for the monitored location. A statistical analysis is performed to maintain an indication of what is normal. A new value of the overall power quality is repetitively generated, every ten minutes in the exemplary monitor, for comparison with normal levels. Thus, referring to FIG. 1, the power quality monitor 1 includes sensors 3 such as potential transformers 5 and current transformers 7 that measure voltage and current, respectively, in the monitored electric power distribution system 9. While a single line representation is used for clarity, typically the electric power distribution system 9 would be a three-phase system, and hence, there would be a potential transformer 5 and current transformer 7 for each phase. The sensed currents and voltages are digitized by an analog to digital converter 11 for input to the processor 13. The power quality monitor 1 further includes an output device, which in the exemplary monitor is a display device 15 generating a visual display of the power quality indicator, which will be further described. The sensed values of current and voltage in the electric power distribution system 1 are utilized by the processor 13 to evaluate parameters relevant to power quality. While there are various parameters that could be monitored, the exemplary monitor focuses on voltage sags and swells, rapid changes in voltage as measured by dv/dt, the percentages of total harmonic distortion (THD) in voltage and in current, and flicker. Sags and swells in voltage are categorized according to the CBEMA/ITI curve established by the Information Technology Industry Council in 2000. This curve is illustrated in FIG. 2 and assigns a numerical value for the severity of duration and amplitude of a deviation in the rms voltage level. A voltage at or near the nominal 100% level has a severity of zero; however, an event that approaches the ITI level is scored as a one. More severe events are scored as two, four, or the highest level of eight. FIG. 2 indicates those categories for both sags and swells. As mentioned above, a calculation of the composite power quality index is made every ten minutes in the exemplary system. Of course, a longer or shorter data gathering period could be used. During this ten-minute period, the voltages and currents are repetitively sampled and values of the selected parameters are determined. The worse case category of sag and swell are recorded for the data recording period, e.g., ten minutes. For the dv/dt parameter, the number of events during which dv/dt exceeds a selected threshold are counted. The total harmonic distortion for voltage is determined as a percentage with respect to a nominal voltage. Similarly, the total harmonic distortion of the current is measured as a percentage of full-scale current. Flicker is measured as Pst in accordance with EN61000-4-15 established by British Standards Institute (BSI). Returning to FIG. 1, it can therefore be seen that the processor 13 includes modules for determining the rms value of voltage at 17, categorizes the severity of the sags and swells at 19 and determines the maximum of each during the data gathering period at 21. The processor 13 detects the dv/dt at 23 and counts the number of times that dv/dt exceeds a threshold at 25. A fast Fourier transform is used at 27 to determine the total harmonic distortion of the current and voltage which is averaged over the data gathering period at 29. A flicker meter 31 detects flicker in the voltages to establish a Pst at 33. Another aspect of the invention is providing the user with the capability of selecting a relative importance of each of the individual parameters. Thus, the user can establish, and even change, weighting factors W0-W5 to be applied to the respective parameters as indicated at 35. Since, as statistics are gathered over time the actual experience can deviate from the user assigned weightings, sensitivities are dynamically adjusted at 37 and used to maintain the user designated weightings. As will be described more fully, the sensitivities and weighting factors are applied to the calculated parameters at 39 to generate a component power quality, PQ0-PQ5, for each of the selected parameters as indicated at 41. The component power qualities are combined by summing at 43 to produce the composite power quality indicator. The processor 13 also includes means for determining the long-term mean of the composite power quality indicator and of each of the component power qualities at 45. The processor then determines the standard deviation of the long-term power quality indicator and from this establishes at least one, but in the exemplary embodiment, two thresholds for the composite power quality indicator. In the exemplary monitor, the first threshold is set at three standard deviations and the second at six standard deviations of the long-term composite power quality indicator. The display 15 generates a visual representation 47 of the power quality indicator relative to the long-term mean of the composite power quality indicator represented by the line 49. The addition of the first threshold 51 and the second threshold 53 delimits three zones for the power quality indicator: a normal zone 55 below the first threshold 51, a caution zone 57 between the first and second thresholds 51 and 53 and an alert zone 59 above the second threshold 53. FIG. 3 is a flow chart 61 illustrating the operation of the processor 13. The power system currents and voltages are sampled repetitively as indicated at 63. The sampling rate is greater than two times the highest harmonic frequency of interest, typically 64 samples/cycle or greater. The routine then performs several functions in parallel. As indicated at 65, the rms voltages are calculated and then evaluated at 67 with respect to the CBEMA/ITI curve to detect the occurrence of any sag or swell which are then each assigned a severity. The largest sag severity and largest swell severity during the data gathering period, e.g., ten minutes, are then recorded at 69. Simultaneously with the evaluation of sags and swells, the voltage samples are processed at 71 to determine if there is excessive dv/dt. The occurrences of excessive dv/dt's in the sampling period are counted at 73. While this is being done, the levels of harmonic distortion in voltage and in current are determined at 75 and average values of total harmonic distortion of each during the ten-minute sampling period are calculated at 77. Flicker in the voltage in units of perceptibility is measured at 79. From this a histogram of perceptibility is created at 81 and used to calculate Pst for the sampling period. At the conclusion of each sampling period, e.g., ten minutes in the exemplary system, the current composite power quality level, PQ, is calculated at 83. This is accomplished by multiplying each of the selected parameters: sag severity, swell severity, dv/dt count, THD current, THD voltage, and flicker Pst by a corresponding sensitivity, S0, S1, S2, S3, S4, S5, and a user-adjustable weight, W0, W2, W3, W4, W5, to produce component power quality levels PQ0, PQ1, PQ2, PQ3, PQ4, and PQ5. These component power quality levels are then summed to produce the composite power quality level CPQ. Following this, the long-term mean and standard deviation of the composite PQ level, CPQ, are determined at 85. The standard deviation is then used to calculate the three sigma and six sigma thresholds. The long-term mean of CPQ and the thresholds are then used along with the most recent CPQ level generated in 83 to generate the display at 87. The sensitivity for each of the component power qualities are then calculated at 89. This requires calculating a long-term mean for each of the component power qualities. The adjusted sensitivity for each component power quality is then calculated as the most recent value multiplied by the corresponding weight assigned to that component power quality times the long-term mean of the composite power quality divided by the long-term mean of the respective component power quality. The program then loops back at 91 to 61 to initiate another sampling period. EXAMPLE In order to establish a statistical basis for normal conditions in an electric power distribution system, data must be collected over the long term. In the exemplary system, a moving average of the composite power quality is maintained over a one-year period. Because this would require the collection of data for one year before the system could be fully utilized, initial calculations of the composite power quality are generated using a one-week moving average. When 52 weeks of data have been accumulated, then the one-year moving average is used. Thus, a first, one-week, long-term moving average is utilized until enough data has been collected for a second long-term moving average, e.g., one year, has been accumulated. In the example, the following Equation 1 is used to calculate the one-week moving average: μ w = 1 1008 [ 1007 μ w - 1 + PQ ] Eq . ( 1 ) Data is calculated for ten-minute intervals, there being 1008 ten-minute intervals in a week. The weekly averages are then utilized to generate the second long-term mean, e.g., one-year moving average, using the following formula: μ avg = 1 52 [ 51 μ avg - 1 + μ w ] Eq . ( 2 ) These formulas 1 and 2 are used to generate the long-term means for both the composite power quality indication and the individual component power qualities. A moving average of the variance of the composite power quality index is generated in the example using the following formula: σ x 2 = 1 1008 [ 1007 σ x - 1 2 + ( PQ - μ w ) 2 ] Eq . ( 3 ) A moving average of the standard deviation, which is the square root of the variance, over one year is calculated by the formula: σ avg = 1 52 [ 51 σ avg - 1 + σ x ] Eq . ( 4 ) The first and second thresholds in the example are three times σavg and six times σavg. The three σavg is added to the long-term mean of the composite power quality, μavg to generate the first threshold 51 shown in FIG. 1 and six μavg is added to the long-term mean, μavg, to generate the second threshold 53. At the end of each data-gathering period, e.g., ten minutes, the component power quality levels for each of the selected parameters are calculated and summed to produce the composite power quality. Table 1 below illustrates an example of this process. TABLE 1 Normalized Weight Component Level Sensitivity Level Setting PQ Sag 0.25 0.125 0.03125 4 0.125 Swell 0.25 0.25 0.0625 2 0.125 dv/dt 0.1 1 0.1 1 0.1 THD V 0.02 20 0.4 1 0.4 (%) THD I (% 0.2 3.3 0.66 1 0.66 of FS) Flicker 0.8 5 4 1 4 (Pst) CPQ = 5.41 The first column lists the parameter. The total harmonic distortion of the current (THD I) is measured as a percentage (%) of the full scale current (FS). The level recorded in the second column is the average value of the parameter during the data-gathering period. For instance, the average value of sag over the last ten-minute period was 0.25. The level of each component is multiplied by the sensitivity in the third column to produce a normalized level in the fourth column. As previously explained, the sensitivity normalizes the levels to maintain the user selected weighting, which is listed in the fifth column. Multiplying the normalized level by the weight setting produces the component power quality in the last column. All of the component power qualities are added to produce the composite power quality, CPQ, which for the exemplary statistics is 5.41. Using the same statistics, σ is 0.715 so that three σ is 2.145 and six σ is 4.29, each of which would be added to the moving average of CPQ calculated at the conclusion of the previous data collection period to which the current CPQ of 5.41 would be compared. As can be seen from Table 1, for the assumed statistics, the weighting of the component power qualities has migrated from the user weight settings. For instance, the flicker Pst has a value of 4 compared to a sag value of 0.125, while under the desire weight setting, the sag would have four times the influence of the flicker. Accordingly, the sensitivities of the component power qualities are adjusted to restore the desired weighting. The sensitivity Sx for each component PQx, is calculated by the formula S x ( n ) = S x ( n - 1 ) * W x * CPQ m PQ xm Eq . ( 5 ) where Wx is the user-assigned weighting factor for that component PQ, CPQm is the long-term mean of the composite power quality, PQxm is the long-term mean of that component power quality, and n is the sampling period. Using the exemplary statistics, the adjusted sensitivities for each of the component PQs is shown in the third column of Table 2 below. The levels of the component PQs from Table 1 are multiplied by the adjusted sensitivities to generate new normalized levels, which when multiplied by the user-selected weight settings, produce adjusted component power qualities. While the adjusted component power qualities in Table 2 differ from those in Table 1, it can be seen that when added together the composite power quality, CPQ, remains the same. TABLE 2 Adjusted Normalized Weight Adjusted Component Level Sensitivity Level Setting PQ Sag 0.25 2.16 0.541 4 2.164 Swell 0.25 2.16 0.541 2 1.082 dv/dt 0.1 5.41 0.541 1 0.541 THD V (%) 0.02 27.05 0.541 1 0.541 THD I (% of 0.2 2.71 0.541 1 0.541 FS) Flicker (Pst) 0.8 0.68 0.541 1 0.541 CPQ = 5.41 The examples above show a rather large change in the relative contributions of the component power qualities, which would normally not occur, but are used for illustrative purposes. It can be seen from this example though that the composite power quality continually adjusts to conditions in the distribution system to continually update what is normal. A significant change in the level of a parameter, especially a heavily-weighted one, can cause the composite power quality indication to make an excursion beyond one or both thresholds, thus alerting the operator to a condition which warrants further investigation. Reference to the current values of the component power qualities would indicate the source of the excursion. While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the claims appended and any and all equivalents thereof. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The invention relates to a system and method for monitoring the performance of an electric power distribution system, and as one aspect, to the generation and presentation of a composite power quality indicator generated from user weighted statistical contributions of various system parameters. 2. Background Information Various techniques have been employed for monitoring the performance of electric power distribution systems. State-of-the-art monitors calculate various electrical parameters such as RMS currents and voltages, peak currents and voltages, power, energy, power factor and the like. Waveform analyzers are used for oscillographic analysis of system waveforms. Numerous methods have been developed to measure and capture power quality events, such as current and voltage sags and swells, voltage surges and excessive harmonic distortion and flicker. However, the state-of-the-art power quality meters lack a means for telling the user whether the existing power quality is normal. For example, such meters will display and record values and minimum and maximum extremes. Nevertheless, until there is a triggered event, the user still does not know whether conditions are normal. Furthermore, attempts to predefine acceptable power quality levels fail to acknowledge unique attributes of a particular electrical system. In one known system, the triggers dynamically adjust to fill available hard disk space within a preprogrammed time period. However, the user still does not know whether the present values of the monitored parameters are normal. In addition, at present, there is no overall indication of power quality. Each parameter is evaluated separately. | <SOH> SUMMARY OF THE INVENTION <EOH>The invention is directed to a system and method of monitoring power quality in an electric power distribution system that generates a composite power quality indicator that is a function of a plurality of system parameters. Each component of the indicator is weighted by a user programmable factor to emphasize or de-emphasize its affect. The composite power quality indicator is updated from statistics generated during a sampling period. As part of each update, each component of the composite power quality indicator is normalized by a sensitivity to a preset threshold before multiplication by the user assigned weighting factor. After multiplication, the results accumulate until they are totaled at the end of the sampling period. During the update, the sensitivity is adjusted to maintain the user selected weighting of the components. More particularly, the method in accordance with one aspect of the invention is directed to repetitively determining the values of a plurality of selected parameters of the electric power distribution system, generating a composite power quality indicator from the values of the plurality of selected parameters and generating an output representing the composite power quality indicator. Generation of the composite power quality indicator can comprise performing a statistical analysis of the values of the plurality of selected parameters. The values of the plurality of selected parameters can be determined by generating samples of each of the plurality of selected parameters over a sampling period and determining the values from the samples generated during the sampling period. As another aspect of the invention, the composite power quality indicator is generated by generating a power quality component for each of the plurality of selected parameters and combining the power quality components to produce the composite power quality indicator. Combining the power quality components can comprise assigning an associated weighting factor to each power quality component selected to produce a selected weighting of that power quality component, multiplying each power quality component by its associated weighting factor to generate a weighted power quality component and adding the weighted power quality components to generate the composite power quality indicator. Preferably, the selected weighting of each of the power quality components is maintained by determining an associated power quality component sensitivity and multiplying the power quality component by its power quality component sensitivity as well as the associated weighting factor. Each power quality sensitivity can be determined by maintaining a long-term mean value for each power quality component and a long-term mean value for the composite power quality indicator and multiplying the associated weighting factor by a ratio of the composite power quality indicator long-term mean to the power quality component long-term mean. Each power quality component sensitivity can be updated by multiplying the most recent power quality component sensitivity by the associated weighting factor and a ratio of the composite power quality indicator long-term mean to the power quality component long-term mean. In accordance with another aspect of the invention, the composite power quality indicator is further generated by generating at least one dynamic threshold for the composite power quality indicator and generating the output includes generating a representation of the composite power quality indicator relative to the at least one dynamic threshold. The at least one dynamic threshold can be generated by generating a long-term mean of the composite power quality indicator, generating a standard deviation of the long-term mean and generating the at least one dynamic threshold as a function of the standard deviation. In this case, the output step further comprises generating a representation of the composite power quality indicator relative to its long-term mean and to the at least one dynamic threshold. The long-term mean of the composite power quality indicator can be generated as a moving average over a selected time. The generation of the composite power quality indicator over the selected time period can comprise generating a first moving average over a first time period and generating a second moving average over a second time period which is a multiple of the first time period. The composite power quality indicator is generated using only the first moving average until the method has been used for at least the second time period and then the composite power quality indicator is generated using the second moving average. In the exemplary embodiments of the invention, the first time period is one week and the second time period is one year. As another aspect of the invention, a power quality monitor for an electric power distribution system comprises sensors for sensing current and voltages in the electric power distribution system, processing means comprising means for repetitively determining values of selected parameters from the currents and voltages and for statistically generating a composite power quality indicator from the values of the selected parameters, and output means providing a representation of the composite power quality indicator. The processing means can comprise means generating power quality components from the values of the selected parameters and combining the power quality components to generate the composite power quality indicator. The processing means can also comprise means generating a long-term mean of the composite power quality indicator and the output means can comprise a display displaying the composite power quality indicator relative to the long-term mean of the composite power quality indicator. In addition, the processing means can comprise means generating a long-term mean of the composite power quality indicator, a standard deviation of the long-term of the composite power quality indicator and at least one dynamic threshold as a function of the standard deviation, and the output means can comprise a display displaying the composite power quality indicator relative to the long-term mean of the composite power quality indicator and relative to the at least one dynamic threshold. In a preferred form, the process means can comprise means generating a first dynamic threshold as a first function of the standard deviation and a second dynamic threshold as a second function of the standard deviation greater than the first function of the standard deviation, and wherein the display displays the first and second dynamic thresholds relative to the long-term mean to define a safe zone for the composite power quality indicator between the long-term mean and the first dynamic threshold, a caution zone between the first and second dynamic threshold and an alert zone farther from the long-term mean than the second dynamic threshold. Also, the processing means can comprise means generating the power quality components from values of the selected parameters, means providing a selected weighting of each power quality component by applying a selected weighting factor to that power quality component to generate weighted power quality components and means combining the weighted power quality components to generate the composite power quality indicator. The processing means can further comprise means maintaining the weighting of each power quality component by applying a continually adjusted sensitivity to each weighed power quality component derived from the long-term mean of the composite power quality indicator and a long-term mean of the power quality component. | 20040219 | 20060523 | 20050825 | 92799.0 | 0 | VO, HIEN XUAN | METHOD AND APPARATUS FOR MONITORING POWER QUALITY IN AN ELECTRIC POWER DISTRIBUTION SYSTEM | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,782,687 | ACCEPTED | Systems and methods for modeling approximate market equilibria | The present invention leverages demarcation of an agent into both a demander and a supplier to provide a polynomial-time method of approximating a supply and demand system's equilibrium value. This provides, in one instance of the present invention, a simplified means to iteratively extract the equilibrium value. By providing demarcated data, the present invention accounts for both demand and supply effects of an agent within a modeled supply and demand system. In one instance of the present invention, a market equilibrium price vector is approximated by employing a revenue value generated for an agent in a current market equilibrium price iteration as a budget value for the agent in the next iteration. This permits market equilibrium value modeling that encompasses an agent's contributions to a market both as a buyer and a seller within the same market for a given good and/or service. | 1. A system that facilitates determining equilibrium values, comprising: a component that receives data relating to supply and demand data for a system and demarcates at least a subset of the data relating to at least one agent operating within the system into demander data and supplier data, respectively; and an approximation component that applies a polynomial-time approximation method to the demarcated data in connection with generating an approximate equilibrium value for the system. 2. The system of claim 1, the system comprising a market system, the demander data comprising buyer data, the supplier data comprising seller data, and the approximate equilibrium value comprising an approximate equilibrium price vector for the market system. 3. The system of claim 2, the approximate equilibrium price vector, comprising an approximate equilibrium price vector, p*, that produces, in conjunction with a bundle of goods, xi, for each agent i, an ε-approximate equilibrium for the market system such that: for every good j: ( 1 - ɛ ) ∑ i = 1 n w j i ≤ ∑ i = 1 n x j i ≤ ∑ i = 1 n w j i ; for all i, a utility, Σj=1muijxji, of agent i is at least (1−ε) times a value of an optimum solution of a maximization of utility function, ui(x), subject to: ∑ j = 1 m p j * x j ≤ ∑ j = 1 m p j * w j i ; ( Eq . 1 ) where m represents types of divisible goods being traded in the market system and wji indicates an initial amount of good j that agent i possesses. 4. The system of claim 2, the polynomial-time approximation method comprising an iterative method that utilizes, at least in part, revenue generated in a previous iteration for a specific agent as a budget for the specific agent in a current iteration. 5. The system of claim 4, the iterative method further utilizes a dummy buyer to account for residual goods. 6. The system of claim 1, the polynomial-time approximation method comprising, at least in part, a linear utility function relating to at least one agent. 7. The system of claim 1, the system comprising a network system, the demander data comprising network client capacity demand data, the supplier data comprising server capacity supply data, and the equilibrium value comprising approximate equilibrium capacity values of the network system. 8. The system of claim 2, the polynomial-time approximation method comprising, at least in part, a polynomial-time method that employs a dichotomous market solution algorithm. 9. The system of claim 8, the dichotomous market solution algorithm comprising a primal-dual heuristics algorithm. 10. The system of claim 8, the dichotomous market solution algorithm comprising a convex programming algorithm. 11. The system of claim 2, the polynomial-time approximation method yields an exact equilibrium price for the market system. 12. A method for facilitating determination of equilibrium values, comprising: receiving data relating to supply and demand data for a system; demarcating at least a subset of the data relating to at least one agent operating within the system into demander data and supplier data, respectively; and applying a polynomial-time approximation method to the demarcated data in connection with generating an approximate equilibrium value for the system. 13. The method of claim 12, the system comprising a market system, the demander data comprising buyer data, the supplier data comprising seller data, and the approximate equilibrium value comprising an approximate equilibrium price vector for the market system. 14. The method of claim 13, the approximate equilibrium price vector, comprising an approximate equilibrium price vector, p*, that produces, in conjunction with a bundle of goods, xi, for each agent i, an ε-approximate equilibrium for the market system such that: for every good j: ( 1 - ɛ ) ∑ i = 1 n w j i ≤ ∑ i = 1 n x j i ≤ ∑ i = 1 n w j i ; for all i, a utility, Σj=1muijxji, of agent i is at least (1−ε) times a value of an optimum solution of a maximization of utility function, ui(x), subject to: ∑ j = 1 m p j * x j ≤ ∑ j = 1 m p j * w j i ; ( Eq . 1 ) where m represents types of divisible goods being traded in the market system and wji indicates an initial amount of good j that agent i possesses. 15. The method of claim 13, the polynomial-time approximation method comprising an iterative method that utilizes, at least in part, revenue generated in a previous iteration for a specific agent as a budget for the specific agent in a current iteration. 16. The method of claim 15, the iterative method further utilizes a dummy buyer to account for residual goods. 17. The method of claim 13, the polynomial-time approximation method comprising, at least in part, a polynomial-time method that employs a dichotomous market solution algorithm. 18. The method of claim 17, the dichotomous market solution algorithm comprising a primal-dual heuristics algorithm. 19. The method of claim 17, the dichotomous market solution algorithm comprising a convex programming algorithm. 20. The method of claim 13, the polynomial-time approximation method yields an exact equilibrium price for the market system. 21. The method of claim 13, the polynomial-time approximation method comprising: initializing with an arbitrary first price vector; setting a variable, D, to represent a maximum deficiency of the price vector; constructing an instance, Mp, of a dichotomous market; executing a dichotomous market solution algorithm on the instance, Mp, of the dichotomous market and outputting a second price vector; setting a budget for i for every agent i with respect to the second price vector according to: e i ′ := ∑ j = 1 m p j ′ w j i ; determining if a budget ratio for every agent i satisfies a budget ratio constraint of: ei′/ei≦1+ε, where ε represents a desired amount of approximation; outputting the second price vector when the budget constraint is satisfied, as the approximate equilibrium price vector for the market system; and iterating the polynomial-time approximation method with the first price vector set equal to the second price vector when the budget constraint is unsatisfied. 22. The method of claim 21, constructing the instance, MP, of the dichotomous market comprising: providing m types of goods and n+1 buyers; setting, for i=1, . . . ,n, a utility of buyer i for the goods as a utility of a corresponding agent in an original instance; and establishing the budget of buyer i according to: e i := ∑ j = 1 m p j w j i , where buyer (n+1) has a budget of en+1:=D and a utility for good j is equal to a price of good j,pj. 23. A system that facilitates determination of equilibrium values, comprising: means for receiving data relating to supply and demand data for a system, and demarcating at least a subset of the data relating to at least one agent operating within the system into demander data and supplier data, respectively; and means for applying a polynomial-time approximation method to the demarcated data in connection with generating an approximated equilibrium value for the system. 24. The system of claim 23, the system comprising a market system, the demander data comprising buyer data, the supplier data comprising seller data, and the approximate equilibrium value comprising an approximate equilibrium price vector for the market system. 25. The system of claim 24, the polynomial-time approximation method comprising an iterative method that utilizes, at least in part, revenue generated in a previous iteration for a specific agent as a budget for the specific agent in a current iteration. 26. The system of claim 24, the polynomial-time approximation method employs, at least in part, a dichotomous market solution algorithm to provide at least one selected from the group consisting of an approximate market equilibrium price and an exact equilibrium market price. 27. A data packet, transmitted between two or more computer components, that facilitates equilibrium value determination, the data packet comprising, at least in part, information relating to an equilibrium value determination system that utilizes, at least in part, demarcation of agent related data into buyer data and seller data to employ in a polynomial-time approximation method that generates an approximated equilibrium value for the system. 28. A computer readable medium having stored thereon computer executable components of the system of claim 1. 29. A device employing the method of claim 12 comprising at least one selected from the group consisting of a computer, a server, and a handheld electronic device. 30. A device employing the system of claim 1 comprising at least one selected from the group consisting of a computer, a server, and a handheld electronic device. | TECHNICAL FIELD The present invention relates generally to computer modeling, and more particularly to systems and methods for modeling approximate equilibrium values for supply and demand systems. BACKGROUND OF THE INVENTION Since the beginning of time, people have desired to obtain items that they did not possess. Often, to accomplish this, they gave something in return in order to obtain what they wanted. Thus, in effect, they were creating a “market” where goods and/or services could be traded. The trading for a particular good usually lasted until everyone who wanted that good obtained one. But, as is often the case, if the one who was supplying the good demanded more in return than what another wanted to give up, that other person left the market without that good. In spite of not getting that particular good, the person, however, was still satisfied because they felt that what they did have was better than the good they did not obtain. This is generally known as “buyer satisfaction.” In other words, buyers enter a marketplace and buy the items they need until the price of a particular item is more than they deem worthy for their own satisfaction. Satisfying a person tends to be a very individual trait; however, over a large number of people involved in a large market, the extreme differences settle out, leaving a general value or “price” of a good for that particular market. If the market price is too low, everyone will demand to have one, quickly depleting the supply of the good. However, if the price of the good is too high, the supply will remain high, with no trades taking place. Ideally, it is most desirable to have the supply equal the demand. Thus, as soon as a good is ready for market, it is quickly sold to someone who needs it. In this manner, a market is considered to be operating “efficiently” due to the supply equaling the demand. All buyers who desire a good at the market price are satisfied, while all sellers have sold their supplies, maximizing sales of their goods. This optimum market price, where supply equals demand, is known as a “market equilibrium price.” Because the market equilibrium price affords great benefits to both sellers and buyers in a market, it is very desirable to ascertain this price, especially for new goods entering a marketplace. A new supplier does not want to manufacture a high volume of goods if its manufacturing costs generate a product price that is too high to move the amount of goods. Likewise, if the new supplier attempts to sell below the market equilibrium price, the supplier will quickly run out of goods because the demand will far exceed the supply. Again, ideally, the supplier wants to produce the right number of goods at the market equilibrium price. Thus, the market equilibrium price becomes a very powerful business tool, foretelling product success or failure in the marketplace. For this reason, great efforts have been made to determine a market equilibrium price for a given good in a given market. Despite these efforts, it is still very difficult to produce a viable market equilibrium price. The amount of variables/factors involved with determining/defining a market are not inconsequential. Market data, such as number of buyers, number of sellers, value to a buyer, production costs, and even weather, play an important role in pricing of goods. Thus, market parameters must be modeled adequately to foretell a market equilibrium price. Accordingly, the behavior of a complex marketplace with multiple goods, buyers, and sellers, can only be understood by analyzing the system in its entirety. In practice, such markets tend toward a delicate balance of supply and demand as determined by the agents' fortunes and utilities. The study of this equilibrium situation is known as general equilibrium theory and was first formulated by Léon Walras in 1874 (see, Éléments d'économie politique pure; ou, Théorie de la richesse sociale (Elements of Pure Economics, or the theory of social wealth); Lausanne, Paris, 1874 (1899, 4th ed.; 1926, rev. ed., 1954, Engl. transl.)). In the Walrasian model, the market consists of a set of agents, each with an initial endowment of goods, and a function describing the utility each one will derive from any allocation. The initial allocation could be sub-optimal, and the task of exchanging goods to mutually increase the utilities might be fairly complicated. A functioning market accomplishes this exchange by determining appropriate prices for the goods. Given these prices, all agents independently maximize their own utility by selling their endowments and buying the best bundle of goods they can afford. This new allocation will be an equilibrium allocation if the total demand for every good equals its supply. The prices that induce this equilibrium are called the market-clearing prices (or market equilibrium price), and the equilibrium itself is called a market equilibrium. Despite the better understanding of how a marketplace functions, modeling such a marketplace has proven extremely difficult. An agent is often both a buyer and a seller of goods. Satisfaction of a buyer can change dependent on many factors including how the buyer is doing as a seller (e.g., were enough goods sold so that the agent could function as a buyer of a good, etc.). Many variables that may seem trivial at first can have profound impact on a marketplace. Theoretical constructs that attempt to provide a basis for modeling the marketplace tend to be extremely complex for these reasons. The complexity often reaches a point where the basis for the model cannot even be resolved with today's fastest computers. Thus, even with the great technological advances in this century, the Walrasian model described in 1874 still cannot be effectively modeled. This leaves society without a means to maximize their markets, resulting in waste of not only manufactured goods, but also a waste of natural resources utilized in products brought to market. Thus, inefficient markets actually cause an increase in overall prices for goods and services. SUMMARY OF THE INVENTION The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later. The present invention relates generally to computer modeling, and more particularly to systems and methods for modeling approximate equilibrium values for supply and demand systems. Demarcation of an agent into both a demander and a supplier is leveraged to provide a polynomial-time method of approximating a supply and demand system's equilibrium value. This provides, in one instance of the present invention, a simplified means to iteratively extract the equilibrium value. By providing demarcated data, the present invention accounts for both demand and supply effects of an agent within a modeled supply and demand system. In one instance of the present invention, a market equilibrium price vector is approximated by employing a revenue value generated for an agent in a current market equilibrium price iteration as a budget value for the agent in the next iteration. This permits market equilibrium value modeling that encompasses an agent's contributions to a market, both as a buyer and a seller within the same market for a given good and/or service. Thus, the present invention more accurately and precisely models an actual market within a polynomial-time constraint. To the accomplishment of the foregoing and related ends, certain illustrative aspects of the invention are described herein in connection with the following description and the annexed drawings. These aspects are indicative, however, of but a few of the various ways in which the principles of the invention may be employed and the present invention is intended to include all such aspects and their equivalents. Other advantages and novel features of the invention may become apparent from the following detailed description of the invention when considered in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an equilibrium modeling system in accordance with an aspect of the present invention. FIG. 2 is another block diagram of an equilibrium modeling system in accordance with an aspect of the present invention. FIG. 3 is a graph illustrating a dichotomous market equality subgraph in accordance with an aspect of the present invention. FIG. 4 is a graph illustrating an equality subgraph in accordance with an aspect of the present invention. FIG. 5 is a flow diagram of a method of facilitating approximating an equilibrium value of a system in accordance with an aspect of the present invention. FIG. 6 is a flow diagram of a method of facilitating approximating an equilibrium price vector of a market system in accordance with an aspect of the present invention. FIG. 7 is another flow diagram of a method of facilitating approximating an equilibrium price vector of a market system in accordance with an aspect of the present invention. FIG. 8 is yet another flow diagram of a method of facilitating approximating an equilibrium price vector of a market system in accordance with an aspect of the present invention. FIG. 9 illustrates an example operating environment in which the present invention can function. FIG. 10 illustrates another example operating environment in which the present invention can function. DETAILED DESCRIPTION OF THE INVENTION The present invention is now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It may be evident, however, that the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing the present invention. As used in this application, the term “component” is intended to refer to a computer-related entity, either hardware, a combination of hardware and software, software, or software in execution. For example, a component may be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a server and the server can be a computer component. One or more components may reside within a process and/or thread of execution and a component may be localized on one computer and/or distributed between two or more computers. A “thread” is the entity within a process that the operating system kernel schedules for execution. As is well known in the art, each thread has an associated “context” which is the volatile data associated with the execution of the thread. A thread's context includes the contents of system registers and the virtual address belonging to the thread's process. Thus, the actual data comprising a thread's context varies as it executes. The present invention provides systems and methods that allow a system's equilibrium state to be determined in a polynomial-time manner. This permits evaluations of systems such as markets to determine effects such as, for example, price increases on the demand of such entities as goods and services and the like. In one instance of the present invention, a linear utility function is utilized in a polynomial-time method to determine a market equilibrium price vector for a market system. The value of the present invention is unlimited in the sense that it can approximate impacts of changing variables within a system, even a global system, to facilitate in maximizing both seller and buyer benefits in the market system. This allows, for example, only the correct amount of goods to be produced for a particular good at a particular price within the system. Thus, resources, such as natural and manmade resources, can be utilized to maximum benefit instead of by producing goods that will remain unsold. The present invention also provides a powerful analytical tool to aid in research and development for new goods and economic solutions, even politically sanctioned tariffs and the like can be accounted for by utilizing the invention. This facilitates immensely in determining pricing strategies and the like. In FIG. 1, a block diagram of an equilibrium modeling system 100 in accordance with an aspect of the present invention is shown. The equilibrium modeling system 100 is comprised of an equilibrium modeling component 102. The equilibrium modeling component 102 receives supply and demand system data 104 and outputs approximate equilibrium value data 106. The approximate equilibrium value data 106 is determined by utilizing, in this instance of the present invention, a polynomial-time method with a linear utility function to assess the supply and demand system data 104. The equilibrium modeling component 102 generally demarcates at least a portion of the supply and demand system data 104 into supply system data and demand system data to be utilized within the polynomial-time method. By processing the supply and demand system data 104 iteratively, in one example of the present invention, a budget of an agent within a current iteration can utilize revenue generated by the agent from a previous iteration. A dummy buyer can also be employed to purchase residual goods in order to facilitate initializing the present invention. The polynomial-time method is discussed in more detail infra. Referring to FIG. 2, another block diagram of an equilibrium modeling system 200 in accordance with an aspect of the present invention is depicted. The equilibrium modeling system 200 is comprised of an equilibrium modeling component 202. The equilibrium modeling component 202 receives supply and demand system data 204 and outputs approximate equilibrium value data 206. The equilibrium modeling component 202 is comprised of an iterative analysis controller component 208, a data demarcation component 210, and a polynomial-time approximation component 212. The iterative analysis controller component 208 provides control for an iterative modeling process and outputs the approximate equilibrium value data 206 at an appropriate point. The iterative analysis controller component 208 initiates the equilibrium modeling component 202 and halts the component 202 when appropriate, either in a predetermined manner and/or dynamic manner. The determination to output the approximate equilibrium value data 206 can be based on, for example, number of iterations, a predetermined threshold error value, and/or a dynamic control process, and the like. The iterative analysis controller component 208 receives the supply and demand system data 204 and outputs supply data and demand data to the data demarcation component 210. The data demarcation component 210 constructs a dichotomous system for supply and demand. Agents of a system are utilized both as suppliers and demanders by the data demarcation component 210. The component 210 utilizes values from data generated from previous iterations to determine values of data to be sent to the polynomial-time approximation component 212. This permits, for example, revenue generated by an agent as a supplier in a previous iteration to be utilized as a budget for the agent as a buyer in a current iteration. The component 210 can also provide a “dummy” agent to facilitate in initializing the polynomial-time approximation component 212. The polynomial-time approximation component 212 processes the data from the data demarcation component 210 utilizing a linear utility function for agents of the system being modeled. Methods utilized by the polynomial-time approximation component 212 are discussed in detail infra. Results from the processing are sent to the iterative analysis controller component 208 to determine if the results are sufficient or not to halt the equilibrium modeling component 202 and output the approximate equilibrium value data 206. In this manner, the present invention provides an approximate equilibrium value within polynomial-time. One skilled in the art can appreciate that various systems can be modeled by the equilibrium modeling component 202. These systems can include, but are not limited to, market systems and computer network traffic systems and the like. Supply and demand features of a system can be exploited by the present invention to provide an approximate equilibrium value that can be utilized to optimize a system. In order to better appreciate the context of the present invention, consider the problem of finding the market equilibrium prices under linear utility functions. A notion of approximate market equilibrium was proposed by Deng, Papadimitriou and Safra (see, Xiaotie Deng, Christos Papadimitriou, and Shmuel Safra; On The Complexity Of Equilibria; In Proceedings of ACM Symposium on Theory of Computing, 2002). Expounding upon this notion, the present invention provides the first fully polynomial-time approximation scheme for finding a market equilibrium price vector. One instance of the present invention employs, in part, a polynomial-time algorithm of Devanur et al. (see, Nikhil R. Devanur, Christos H. Papadimitriou, Amin Saberi, and Vijay V. Vazirani; Market Equilibrium Via A Primal-Dual-Type Algorithm; In The 43rd Annual IEEE Symposium on Foundations of Computer Science, 2002; for a variant of the problem in which there is a clear demarcation between buyers and sellers). Much work has been devoted to establishing the existence of market equilibria (see, K. Arrow and G. Debreu; Existence Of An Equilibrium For A Competitive Economy; Econometrica, 22:265-290, 1954 and A. Wald; On some systems of equations of mathematical economics; Zeitschrift für Nationalökonomie, Vol. 7, 1936. Translated, 1951, Econometrica 19(4), pp. 368-403). This difficult problem is typically approached by placing different assumptions on the endowment and utility functions of the agents. The seminal work of Arrow and Debreu proves the existence of market equilibria in the quite general setting of concave utility functions by applying Kakutani's fixed point theorem. This generality comes at a high price: the proof is non-constructive and so does not give an algorithm to compute the equilibrium prices. Yet computing these prices can be of considerable importance for predicting the market. For example, in order to determine the effects of a change in a tariff, the equilibrium prices must be able to be computed before and after the tariff change. Equilibrium prices also have applications in computer science. Kelly and Vazirani (see, F. P. Kelly and V. V. Vazirani; Rate Control As A Market Equilibrium) show that the rate control for elastic traffic in a network can be reduced to a market equilibrium problem. Despite the impressive progress in computing equilibrium prices (see, K. J. Arrow, H. D. Block, and L. Hurwicz; On The Stability Of Competitive Equilibrium II; Econometrica, 27:82-109, 1959; K. J. Arrow and L. Hurwicz; On The Stability Of Competitive Equilibrium I; Econometrica, 26:522-52, 1958; W. C. Brainard and H. E. Scarf; How To Compute Equilibrium Prices In 1891; Cowles Foundation Discussion Paper 1270, 2000; and H. Scarf; The Computation of Economic Equilibria (with collaboration of T. Hansen); Cowles Foundation Monograph No. 24, New Haven: Yale University Press, 1973), especially the seminal work of Scarf, polynomial-time methods have evaded researchers. In the special case of linear utility functions, Deng, Papadimitriou, and Safra (see also, Christos H. Papadimitriou; Algorithms, Games, And The Internet; In Proceedings of ACM Symposium on Theory of Computing, 2001) provide a polynomial-time algorithm when the number of goods or agents is bounded. Devanur et al. obtain a polynomial-time algorithm via a primal-dual-type approach when there is a demarcation between sellers and buyers. However, the question of existence of a polynomial-time algorithm for the general case was unsolved. The present invention provides the first fully polynomial-time approximation scheme for this problem. Since the market equilibrium problem is not an optimization problem, it needs to be clarified as to what an approximate market equilibrium entails. A definition is utilized as proposed by Deng, Papadimitriou, and Safra. According to this definition, an approximate market equilibrium is a price vector for which there is an allocation of goods to agents of a market that approximately clears the market, and each agent is approximately, maximally-happy with the allocation (subject to their budget constraint). A precise definition is presented infra. In a general market equilibrium problem, all agents are buyers as well as sellers. However, the algorithm of Devanur et al. works only when the buyers and sellers are different. The reason is that their algorithm requires that the buyers' budgets be known beforehand. The present invention overcomes the limitations of Devanur et al., in part, by running in iterations and letting the budget of an agent in a current iteration be revenue the agent generated in a previous iteration. Another limitation of the algorithm of Devanur et al. is that it requires an initial setting of prices in which no good is undersold. The present invention overcomes this limitation as well by adding a dummy buyer who has enough money to buy the residual goods. As an illustration of the present invention, consider a market consisting of n agents trading m types of divisible goods. Initially, each agent i has an endowment wi εm of goods (i.e., wij indicates the amount of good j that agent i initially has). Assume, without loss of generality, that in total there is one unit of each type of good in the initial endowments (i.e., ∑ i = 1 n w j i = 1 for every good j). Also, each agent i has a utility function ui: m+. That is, if xεm is a vector that specifies how much of each good agent i has, then ui(x) indicates the utility (or happiness) of agent i. If a price of p*j dollars is set for one unit of good j, then agent i can sell its endowment for a total of ∑ j = 1 m p j * w j i dollars. Utilizing this money, the agent can buy a bundle xεm of goods. Since each agent is trying to maximize its utility, the bundle x is a solution to the following maximization equation: maximize u i ( x ) subject to ∑ j = 1 m p j * x j ≤ ∑ j = 1 m p j * w j i . ( Eq . 1 ) Such a solution x is called an optimal bundle for agent i. If the function ui is strictly concave (i.e., for every x≠xεm, ui((x+x′)/2)>(ui(x)+ui(x′))/2), then there is a unique optimal bundle for agent i. The Arrow-Debreu theorem states the following: Theorem A: (Arrow and Debreu) Consider the above setting and assume that ui's are strictly concave. Then there is a price vector p* such that if each agent buys the optimal bundle with respect to p*, then the market clears. In other words, if xiεm is the optimal bundle for agent i with respect to p*, then for every good j, ∑ i = 1 n x j i = ∑ i = 1 n w j i . If the utility functions are concave but not strictly concave (e.g., if they are linear), then the optimal bundle is not necessarily unique. In this case, the Arrow-Debreu theorem says that there is a price vector p* and a bundle xi for each agent i, such that xi is an optimal bundle for i with respect to p*, and if for every i, agent i buys the bundle xi, then the market clears. The proof of the Arrow-Debreu theorem is existential and utilizes a fixed point theorem. Therefore, a natural question is whether one can efficiently compute the equilibrium prices that are guaranteed to exist by the Arrow-Debreu theorem. The present invention can be utilized in formulating a representative model which utilizes this theorem. Devanur et al. present a polynomial-time algorithm that computes the market-clearing prices in a market with the following conditions: 1. All utility functions are linear, i.e., u i ( x ) = ∑ j = 1 m u ij x j for non-negative constants uij. 2. There is a distinction between buyers and sellers in the market. More precisely, there are m sellers, each having one unit of a different type of good, and n buyers in the market. Each buyer i has a given budget ei, and wants to buy a certain amount of each good to maximize the buyer's utility, subject to the buyer's budget constraint. A market with this property is denoted as a dichotomous market. The algorithm of Devanur et al. is referred to as the DPSV algorithm. The idea of the DPSV algorithm is to start from a price vector p0 satisfying an invariant stated below and keep increasing the prices subject to not violating the invariant, until the equilibrium prices converge. In order to introduce the invariant, the concept of the equality subgraph is first defined. In FIG. 3, a graph illustrating a dichotomous market equality subgraph 300 in accordance with an aspect of the present invention is shown. Let p be a price vector. For each agent i, let ai=maxj{uij/pj} (αi is agent i's bang per buck). The equality subgraph N(p) 300 is a network whose vertex set consists of a source s 302, a vertex aj for each good j 304, a vertex bi for each buyer i 306, and a sink t 308. Let A 310 and B 312 denote the sets of aj's and bi's, respectively. There is an edge 314 from s to each ajεA of capacity pj (the price of j) and an edge 316 from each biεB to t of capacity ei (the budget of i). Also, for each buyer i and good j, if ai=uij/pj, then an edge 318 is placed from aj to bi of infinite capacity. This edge is called an equality edge. Notice that by this definition a bundle is optimal for buyer i with respect to the prices p if and only if its total price is equal to the budget of i, and it only contains goods that have an equality edge to bi in N(p). The invariant of the DPSV algorithm can be stated as: Invariant 1. The prices p are such that (s, A∪B∪t) is a min-cut in N(p). For a price vector p and a subset S of goods, define Γp(S) as the set of buyers i such that N(p) contains an edge from aj to bi for some jεS. In other words, Γp(S) is the set of buyers who are interested in at least one of the goods in S at price p. For any S⊂A, the money of S (denoted by mp(S)) is the sum of the prices of the goods in S. Similarly, the money of a subset S of B (denoted by me(S)) is the sum of the budgets of the buyers in S. By the above definition, it is straightforward to see that Invariant 1 is equivalent to the following: Invariant 2. The prices p are such that for every S⊂A it exists that mp(S)≦me(Γp(S)). Since the DPSV algorithm starts with an arbitrary price vector satisfying the invariant and only increases the prices until it reaches the equilibrium, therefore, it proves the following stronger statement. This observation is utilized in the analysis of one of the present invention's methods. Theorem B: (Devanur et al.) Let p0 be a price vector satisfying Invariant 1. Then there is a market-clearing price vector p* such that p*j≧pj0 for every good j. Furthermore, p* can be computed in polynomial time. In one instance of the present invention, a method is presented that computes an approximate market equilibrium in the setting of the Arrow-Debreu theorem (where there is no dichotomy between buyers and sellers) assuming that the utility functions are linear. This “approximately” overcomes a limitation of Devanur et al. Since the market equilibrium problem is not an optimization problem, an approximate market equilibrium must be clarified. Deng et al. provides the following natural definition for the notion of approximate market equilibria: Definition 1. An ε-approximate equilibrium for a market is a price vector p* and a bundle xi for each agent i such that: The market approximately clears, i.e., for every good j, ( 1 - ɛ ) ∑ i = 1 n w j i ≤ ∑ i = 1 n x j i ≤ ∑ i = 1 n w j i . For all i, the utility ∑ j = 1 m u ij x j i of agent i is at least (1−ε) times the value of the optimum solution of the maximization equation (1). The present invention provides at least two methods for computing market-clearing prices in a market with m types of goods and n agents, each having an initial endowment wi of goods and a linear utility function u i ( x ) = ∑ j = 1 m u ij x j . The first method is similar in nature to the DPSV algorithm and is based on the approach of increasing the price of oversold items until an equilibrium is reached. The second method is a modification of the first method, proved through utilization of Theorem B that computes an approximate equilibrium in polynomial time. First, an equality subgraph 400 corresponding to the price vector p is defined. In FIG. 4, a graph illustrating the equality subgraph 400 in accordance with an aspect of the present invention is depicted. The definition is similar to the definition of the equality subgraph 300 in a dichotomous market presented supra (see also, FIG. 3), except here the budget of each buyer is a function of prices. More precisely, the equality subgraph 400 has m vertices in the first part A 410, n vertices in the second part B 412, equality edges 418 between A 410 and B 412 as defined supra, an edge 414 of capacity pj from a source s 402 to a vertex ajεA 404, and an edge 416 of capacity ∑ j = 1 m p j w j i from a vertex biεB 406 to a sink t 408. This equality subgraph 400 is denoted by N′(p) to avoid confusion with the equality subgraph 300 for dichotomous markets defined supra. The money of a set (denoted by mp(S)) is defined as before, utilizing ∑ j = 1 m p j w j i as the budget of buyer i. For a set S⊂A, the deficiency of S (denoted by defp(S)) is defined as mp(S)−mp(Γp(S)). The maximum deficiency of the price vector p (denoted by maxdef(p)) is the maximum value of defp(S) over all S⊂A. Thus: Proposition 1. Assume p is a price vector and the budgets defined above are non-zero. Let {s}∪S∪T be the s-side of the minimum st-cut in N′(p). Then T=Γp(S) and the deficiency of the set S is equal to the maximum deficiency of p. A set S with def (S)=maxdef(p) is called a maximally deficient set with respect to p. By the above fact, finding a maximally deficient set is equivalent to finding a minimum st-cut in N′(p). Thus, the first method is as follows: Method 1: 1. Start from an arbitrary price vector, say p0=(1, 1, . . . , 1). 2. Find the largest maximally deficient set S. Let D=def(S). If D=0 then stop. 3. Remove all equality edges between A\S and Γp(S) from N′(p). 4. Increase the prices of the goods in A\S continuously and at the same rate (i.e., multiply these prices by a factor δ initially equal to 1 and increase δ continuously), until one of the following events occur: (a) A new equality edge is added to N′(p). (b) For a set S′S, the deficiency of S′ becomes equal to D. In either case, continue from Step 2. If none of the above events happens for any value of δ>1, then proceed to the next step. 5. Set the prices of the goods in S to zero, remove these goods from the set of goods, and start again from Step 2. Step 4 in the above method can be implemented utilizing binary search over values of δ and/or utilizing a parametric network flow algorithm (see, Giorgio Gallo, Michael D. Grigoriadis, and Robert E. Tarjan; A Fast Parametric Maximum Flow Algorithm And Applications; SIAM J. Comput., 18(1):30-55, 1989) to find the first event that occurs. Notice that Step 5 in the above method is only for taking care of (pathological) cases where in the equilibrium some of the prices are zero. If, for example, it is assumed that each agent has a non-zero utility for each good (i.e., uij>0 for every i, j), then this step is not needed. The premise of Method 1 is that it can be observed that if the maximum deficiency of the initial price vector p0 is D0, then the method never lets the maximum deficiency of p to increase beyond D0. On the other hand, the method keeps increasing the total price of all goods. Therefore, the ratio of the maximum deficiency to the total prices will converge to zero. However, since in each step the prices might increase only slightly, the polynomial upper bound on the running time of Method 1 remains unknown. Instead, the method is modified to utilize the DPSV algorithm as a subroutine in each iteration. This enables a provable polynomial bound on the time it takes until the method reaches an approximate equilibrium. Method 2: 1. Start from an arbitrary price vector, say p:=(1, 1, . . . , 1). 2. Let D:=maxdef(p). 3. Construct an instance Mp of a dichotomous market as follows: There are m types of goods and n+1 buyers. For i=1, . . . , n, the utility of buyer i for the goods is the same as the utility of the corresponding agent in the original instance. Also, the budget of buyer i is e i : = ∑ j = 1 m p j w j i . The (n+1)'th buyer has a budget of en+1:=D and its utility for good j is equal to pj (i.e., at price p, buyer n+1 is equally interested in all goods). 4. Run the DPSV algorithm on the instance Mp starting from the price vector p. Let p′ denote the output of this algorithm. 5. For every agent i, let e i ′ : = ∑ j = 1 m p j ′ w j i be the budget of i with respect to p′. If ei′/ei≦1+ε for every agent i, then output p′ and stop. 6. Let p:=p′. Go to Step 2. Method 2 finds an ε-approximate market equilibrium after, at most, polynomially many iterations. One skilled in the art will appreciate that any algorithm/heuristic (e.g., primal-dual heuristics and/or convex programming algorithms) can be employed as a dichotomous market solution algorithm in place of the DPSV algorithm utilized supra to find equilibrium prices exactly and/or approximately on Mp, starting with price vector p and yielding p′. Proof that Method 2 is correct (i.e., it computes an ε-approximate market equilibrium) and terminates in polynomial time is now analyzed. Start with the following simple lemma, which shows that the price vector p satisfies Invariant 2 of the DPSV algorithm on the instance Mp, and, therefore, in Step 4 of Method 2, the DPSV algorithm runs with the initial price vector p. Lemma 1: In Step 4 of Method 2, the price vector p satisfies Invariant 2 of the DPSV algorithm on the instance Mp. Proof: It is enough to notice that by the definition, at the price p, the buyer n+1 is interested in all goods. Therefore, adding this buyer to the set of buyers decreases the deficiency of every set by the budget of buyer n+1, which is D. Therefore, after adding buyer n+1, the maximum deficiency is non-positive. Thus, p satisfies Invariant 2 on the instance Mp. The following lemma shows that when Method 2 stops in Step 5, it must have found an ε-approximate market equilibrium. Lemma 2: Assume Method 2 terminates and outputs the price vector p*:=p′. Then there exist a bundle xi for each agent i such that: The market clears, i.e., for every good j, ∑ i = 1 n x j i = ∑ i = 1 n w j i . For all i, the utility ∑ j = 1 m u ij x j i of agent i is at least (1−ε) times the value of the optimum solution of the maximization equation (1). Therefore, the price vector p* together with the allocation x is an ε-approximate market equilibrium. Proof: Consider the instance Mp constructed in the last iteration of the method and the equality subgraph N(p′) for this instance. Find a maximum flow from s to t in this network and let yij denote the amount of flow from the aj to bi divided by p′j. Thus, the total amount of flow entering the vertex bi is Σjp′jyji. Therefore, since p′ is a market-clearing price in Mp, it follows that Σjp′jyji=ei for every i. By Theorem B, p′≧p and, therefore, ei′>ei for every i. This shows that the allocation yi does not violate the budget constraint of agents. Also, by the termination condition of the method, it follows that ei≧e′i/(1+ε)≧(1−ε)ei′. Thus, Σjpj′yji≧(1−ε)ei′. That is, every agent uses at least a (1−ε) fraction of its budget. Since utility functions are linear, the solution of the maximization equation (1) is precisely the budget of agent i times the bang per buck for agent i. By the definition of the equality subgraph, the agent only buys goods that have the highest bang per buck for the agent. Therefore, the utility that agent i has for the allocation yi is at least a (1−ε) fraction of the agent's optimal bundle. Thus, the allocation yi satisfies the second condition. In order to satisfy the first condition, the allocation yi is changed as follows: by the principle of conservation of money the total extra money that the agents have after buying the bundles yi is equal to the total price of the unsold goods. These goods are distributed among the agents arbitrarily, so that all goods are sold (i.e., the market clears). Let xi's denote the resulting allocations. Since by doing so, the utility of any agent is not increased, therefore, the allocation xi satisfies both conditions of the lemma. Lemmas 1 and 2 together prove that Method 2 is correct. Now, it is shown that it terminates after polynomially many iterations. This is based on the fact that the price vector p in Method 2 satisfies the following invariant: Lemma 3: Method 2 never increases the maximum deficiency of the price vector p. Proof: The maximum deficiency of the price vector p′ computed in Step 4 must be shown that it is not more than D (the maximum deficiency of p). Since the output p′ of the DPSV algorithm must satisfy Invariant 2, mp′(S)≦me(Γ′p′(S)) for every set S of goods in Mp, where Γ′p′(S) denotes the set of buyers that have an equality edge from the goods in S in the equality subgraph N(p′) for the instance Mp(Γ′ is utilized instead of Γ to indicate the presence of the dummy buyer n+1) and me(Γ′p′(S)) is computed utilizing the budgets e i : = ∑ j = 1 m p j w j i . Therefore, if the buyer n+1 is removed from this instance, it leaves: mp′(S)−me(Γ′p′(S)\{n+1})≦D (Eq. 2) for every set S. On the other hand, by Lemma 2 and Theorem B, the price vector p′ must satisfy pj′≧pj for every good j. Therefore: m e ( Γ p ′ ′ ( S ) \ { n + 1 } ) = ∑ i ∈ Γ p ′ ′ ( S ) \ { n + 1 } e i = ∑ i ∈ Γ p ′ ( S ) ∑ j = 1 m p j w j i ≤ ∑ i ∈ Γ p ′ ( S ) ∑ j = 1 m p j ′ w j i = m p ′ ( Γ p ′ ( S ) ) . ( Eq . 3 ) By Equations 2 and 3: defp′(S)=mp′(S)−mp′(Γp′(S))≦mp′(S)−me(Γ′p′(S)\{n+1})≦D. This completes the proof of the lemma. The running time of Method 2 is analyzed as follows: Lemma 4: Let emin:=miniΣjwji be the minimum budget ei in the first iteration of the algorithm. Then Method 2 terminates after at most O ( n ɛ log ( m ɛ e min ) ) iterations. Proof: By Theorem B, p′≧p and, therefore, ei′≧ei for every i. On the other hand: ∑ i e i ′ = ∑ j p j ′ = ∑ j p j + D = ∑ i e i + D . Therefore, for every i, ei′−ei≦D. (Eq. 4) Let D0 denote the maximum deficiency of the original price vector (1, 1, . . . , 1). By Lemma 3, the value of D in Method 2 is always less than or equal to D0. Also, D0≦m by definition. Therefore, by Equation (4), ei′−ei≦m. Thus, e i ′ e i ≤ 1 + m e i . By the above inequality, the event e i ′ e i > 1 + ɛ can happen only if m e i > ɛ or e i < m / ɛ . However, if this event happens in some iteration, then the value of ei in the next iteration (which is the same as the value of ei′ in the current iteration) will grow by a factor of 1+ε. This means that after k = O ( 1 ɛ log ( m ɛ e min ) ) occurrences of the event e i ′ e ′ > 1 + ɛ , the value of ei will be at least e min ( 1 + ɛ ) k > m ɛ , and, therefore, by the above observation, the event e i ′ e ′ > 1 + ɛ cannot happen anymore. On the other hand, in every iteration in which the algorithm does not stop, this event must happen for at least one i. Thus, after at most O ( n ɛ log ( m ɛ e min ) ) iterations the algorithm stops. Lemmas 2 and 4 together with the observation that log(1/emin) is upper bounded by a polynomial in the size of input imply a polynomial-time method. Theorem 1: For every ε>0, Method 2 computes an ε-approximate market equilibrium in time polynomial in 1/ε and the size of the input. Note. Using Lemma 3 and the fact that in each iteration Σjp′j=Σjpj+D, it is straightforward to show the ratio of the maximum deficiency to the total price of goods (maxdef(p)/Σjpj) in the r th iteration of Method 2 is at most 1/r . Therefore, if instead of the requirements of Definition 1, the relative maximum deficiency is only needed to be less than ε. Therefore, it is enough to run Method 2 for 1/e iterations. Thus, the present invention provides a polynomial-time approximation scheme for computing an approximate market equilibrium for a general market with linear utilities. Although a proof of obtaining a polynomial-time algorithm for computing the exact equilibrium has not been illustrated for Method 1, this instance of the present invention may provide such an algorithm. The proof is limited by the problem of analyzing the running time of Method 1. It has been conjectured that the basic DPSV algorithm runs in strongly polynomial time. A solution to this conjecture might be the first step toward analyzing the running time of Method 1. Another instance of the present invention could also be applied to cases of strictly concave utility functions. In the Arrow-Debreu setting, strictly concave utility functions are more interesting than linear utility functions, since if the utilities are strictly concave, all optimal bundles are uniquely determined from the prices. Even for special classes of strictly concave utility functions, computing efficient market-clearing price is still a problem. Yet another instance of the present invention could utilize unknown initial agent endowments and utilities. Thus, scenarios where the agents are allowed to behave strategically in announcing their initial endowment and/or utility function could be analyzed. In view of the exemplary systems shown and described above, methodologies that may be implemented in accordance with the present invention will be better appreciated with reference to the flow charts of FIGS. 5-8. While, for purposes of simplicity of explanation, the methodologies are shown and described as a series of blocks, it is to be understood and appreciated that the present invention is not limited by the order of the blocks, as some blocks may, in accordance with the present invention, occur in different orders and/or concurrently with other blocks from that shown and described herein. Moreover, not all illustrated blocks may be required to implement the methodologies in accordance with the present invention. The invention may be described in the general context of computer-executable instructions, such as program modules, executed by one or more components. Generally, program modules include routines, programs, objects, data structures, etc., that perform particular tasks or implement particular abstract data types. Typically, the functionality of the program modules may be combined or distributed as desired in various instances of the present invention. In FIG. 5, a flow diagram of a method 500 of facilitating approximating an equilibrium value of a system in accordance with an aspect of the present invention is shown. The method 500 starts 502 by obtaining supply and demand system data 504. The system data can be for any system that yields a variable based upon a supply and demand mechanism. Thus, the system can be, for example, a market system and/or a computer network system and the like. For example, the market system variable can be a pricing equilibrium value and the computer network system variable can be based upon the supply and demand of network capacity. An approximate system equilibrium value is then determined utilizing a polynomial-time process 506, ending the flow 508. The approximate equilibrium value can be determined by utilizing, in one instance of the present invention, a polynomial-time method with a linear utility function to assess the supply and demand system data. The polynomial-time process generally demarcates at least a portion of the system data into supply system data and demand system data. This provides an accounting for an agent of the system being both a demander and a supplier within the same system. The demarcation process within the polynomial-time process provided by the present invention can also be utilized to simplify a system equilibrium method that employs a concave utility function. Referring to FIG. 6, a flow diagram of a method 600 of facilitating approximating an equilibrium price vector of a market system in accordance with an aspect of the present invention is illustrated. The method 600 starts 602 by obtaining market system data 604. A portion of the market system data for an agent of the market system is demarcated into buyer data and seller data for that agent 606. This demarcation method of the present invention can be utilized with linear and/or concave utility functions of a market equilibrium determination method to simplify the processing. A previous iteration's agent revenue data is then utilized as the agent's budget for the current iteration to iteratively determine an approximate market equilibrium price vector in a polynomial-time process 608, ending the flow 610. The polynomial-time process leverages the dichotomous system via iterative analysis to provide a polynomial-time solution. Thus, agents of a market system are utilized both as suppliers and demanders to increase accuracy of the solution. A determination to output the approximate market equilibrium price vector can be based on, for example, number of iterations, a predetermined threshold error value, and/or a dynamic control process, and the like. In other instances of the present invention, a “dummy” agent is provided to facilitate in initializing the polynomial-time process. The dummy buyer is employed to purchase residual goods in order to facilitate initializing the present invention. This permits the initial market system to be “sold out” completely even when an initial price is substantially off from the desired equilibrium price. One skilled in the art will appreciate that the present invention's methods can be utilized in totality and/or in portions to facilitate determining market equilibria. Thus, demarcating agent data and/or iteratively processing demarcated agent data can be utilized to reach a solution in linear and/or concave-based system processing within the scope of the present invention. Looking at FIG. 7, another flow diagram of a method 700 of facilitating approximating an equilibrium price vector of a market system in accordance with an aspect of the present invention is depicted. The method 700 starts 702 by initializing with an arbitrary price vector, p0 for an equality subgraph N′(p) 704. The largest maximally deficient set of a subset of goods, S, is found and denoted as D=def (S) 706. A determination is then made as to whether D is equal to zero 708. If D=0, the current price vector is output as an equilibrium price vector 710, ending the flow 712. If not, any equality edges from between A\S and Γp(S) are removed from N′(p) 714. Prices of goods in A\S are then continuously increased each iteration and at the same rate (e.g., utilizing a δ factor initialized at one and multiplying it with the price) 716. This can be implemented utilizing binary search over values of δ and/or utilizing a parametric network flow algorithm to find the first event that occurs. A determination is then made as to whether the increase has produced a new equality edge or whether a deficiency of S′=D, where S′S 718. If either of these events occurs, a new iteration is started by finding the largest maximally deficient set of S 706. If neither event occurs, a determination is made as to whether the δ factor has been incremented beyond the first initial value of one 720. If not, a new iteration is started beginning with finding the largest maximally deficient set of S 706. However, if the δ factor is greater than one, prices of goods in S are set equal to zero and removed from the set of goods 722. This step in the present invention is only for taking care of (pathological) cases where in the equilibrium some of the prices are zero. If, for example, it is assumed that each agent has a non-zero utility for each good (i.e., uij>0 for every i, j), then this step is not required. The method 700 then continues back for another iteration by finding the largest maximally deficient set of S 706. Essentially, if the maximum deficiency of the initial price vector p0 is D0, then the method 700 never lets the maximum deficiency of p to increase beyond D0. On the other hand, the method 700 keeps increasing the total price of all goods. Therefore, the ratio of the maximum deficiency to the total prices will converge to zero. Turning to FIG. 8, yet another flow diagram of a method 800 of facilitating approximating an equilibrium price vector of a market system in accordance with an aspect of the present invention is shown. The method 800 starts 802 by initializing with an arbitrary price vector, p 804. Then let D:=maxdef (p) 806. An instance, Mp, of a dichotomous market (i.e., demarcated buyers and sellers) is constructed 808. Mp is built on m types of goods and n+1 buyers. For i=1, . . . , n, the utility of buyer i for the goods is the same as the utility of the corresponding agent in the original instance. Also, the budget of buyer i is e i : = ∑ j = 1 m p j w j i . The (n+1)'th buyer has a budget of en+1:=D and its utility for good j is equal to pj (i.e., at price p, buyer n+1 is equally interested in all goods). A dichotomous market solution algorithm is then executed on the dichotomous market instance, Mp, with a starting price vector, p, yielding an output result of price vector p′ 810. Any algorithm/heuristic (e.g., primal-dual heuristics and/or convex programming algorithms) can be employed as the dichotomous market solution algorithm to find equilibrium prices exactly and/or approximately on Mp, starting with price vector p and yielding p′. Then, for every agent i, let e i ′ : = ∑ j = 1 m p j ′ w j i be the budget of i with respect to p′ 812. A determination is then made as to whether every agent i satisfies ei′/ei≦1+ε 814. If every agent i meets this criterion, p′ is output as an approximate equilibrium price vector for the market 816, ending the flow 818. However, if this criterion is not met, set p:=p′ 820 and begin a new iteration at letting D:=maxdef (p) 806. By utilizing the dichotomous market solution algorithm as a subroutine in each iteration, the present invention provides an ε-approximate market equilibrium after, at most, polynomially many iterations. In order to provide additional context for implementing various aspects of the present invention, FIG. 9 and the following discussion is intended to provide a brief, general description of a suitable computing environment 900 in which the various aspects of the present invention may be implemented. While the invention has been described above in the general context of computer-executable instructions of a computer program that runs on a local computer and/or remote computer, those skilled in the art will recognize that the invention also may be implemented in combination with other program modules. Generally, program modules include routines, programs, components, data structures, etc., that perform particular tasks and/or implement particular abstract data types. Moreover, those skilled in the art will appreciate that the inventive methods may be practiced with other computer system configurations, including single-processor or multi-processor computer systems, minicomputers, mainframe computers, as well as personal computers, hand-held computing devices, microprocessor-based and/or programmable consumer electronics, and the like, each of which may operatively communicate with one or more associated devices. The illustrated aspects of the invention may also be practiced in distributed computing environments where certain tasks are performed by remote processing devices that are linked through a communications network. However, some, if not all, aspects of the invention may be practiced on stand-alone computers. In a distributed computing environment, program modules may be located in local and/or remote memory storage devices. As used in this application, the term “component” is intended to refer to a computer-related entity, either hardware, a combination of hardware and software, software, or software in execution. For example, a component may be, but is not limited to, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and a computer. By way of illustration, an application running on a server and/or the server can be a component. In addition, a component may include one or more subcomponents. With reference to FIG. 9, an exemplary system environment 900 for implementing the various aspects of the invention includes a conventional computer 902, including a processing unit 904, a system memory 906, and a system bus 908 that couples various system components, including the system memory, to the processing unit 904. The processing unit 904 may be any commercially available or proprietary processor. In addition, the processing unit may be implemented as multi-processor formed of more than one processor, such as may be connected in parallel. The system bus 908 may be any of several types of bus structure including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of conventional bus architectures such as PCI, VESA, Microchannel, ISA, and EISA, to name a few. The system memory 906 includes read only memory (ROM) 910 and random access memory (RAM) 912. A basic input/output system (BIOS) 914, containing the basic routines that help to transfer information between elements within the computer 902, such as during start-up, is stored in ROM 910. The computer 902 also may include, for example, a hard disk drive 916, a magnetic disk drive 918, e.g., to read from or write to a removable disk 920, and an optical disk drive 922, e.g., for reading from or writing to a CD-ROM disk 924 or other optical media. The hard disk drive 916, magnetic disk drive 918, and optical disk drive 922 are connected to the system bus 908 by a hard disk drive interface 926, a magnetic disk drive interface 928, and an optical drive interface 930, respectively. The drives 916-922 and their associated computer-readable media provide nonvolatile storage of data, data structures, computer-executable instructions, etc. for the computer 902. Although the description of computer-readable media above refers to a hard disk, a removable magnetic disk and a CD, it should be appreciated by those skilled in the art that other types of media which are readable by a computer, such as magnetic cassettes, flash memory cards, digital video disks, Bernoulli cartridges, and the like, can also be used in the exemplary operating environment 900, and further that any such media may contain computer-executable instructions for performing the methods of the present invention. A number of program modules may be stored in the drives 916-922 and RAM 912, including an operating system 932, one or more application programs 934, other program modules 936, and program data 938. The operating system 932 may be any suitable operating system or combination of operating systems. By way of example, the application programs 934 and program modules 936 can include an equilibrium value determination scheme in accordance with an aspect of the present invention. A user can enter commands and information into the computer 902 through one or more user input devices, such as a keyboard 940 and a pointing device (e.g., a mouse 942). Other input devices (not shown) may include a microphone, a joystick, a game pad, a satellite dish, wireless remote, a scanner, or the like. These and other input devices are often connected to the processing unit 904 through a serial port interface 944 that is coupled to the system bus 908, but may be connected by other interfaces, such as a parallel port, a game port or a universal serial bus (USB). A monitor 946 or other type of display device is also connected to the system bus 908 via an interface, such as a video adapter 948. In addition to the monitor 946, the computer 902 may include other peripheral output devices (not shown), such as speakers, printers, etc. It is to be appreciated that the computer 902 can operate in a networked environment using logical connections to one or more remote computers 960. The remote computer 960 may be a workstation, a server computer, a router, a peer device or other common network node, and typically includes many or all of the elements described relative to the computer 902, although, for purposes of brevity, only a memory storage device 962 is illustrated in FIG. 9. The logical connections depicted in FIG. 9 can include a local area network (LAN) 964 and a wide area network (WAN) 966. Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets and the Internet. When used in a LAN networking environment, for example, the computer 902 is connected to the local network 964 through a network interface or adapter 968. When used in a WAN networking environment, the computer 902 typically includes a modem (e.g., telephone, DSL, cable, etc.) 970, or is connected to a communications server on the LAN, or has other means for establishing communications over the WAN 966, such as the Internet. The modem 970, which can be internal or external relative to the computer 902, is connected to the system bus 908 via the serial port interface 944. In a networked environment, program modules (including application programs 934) and/or program data 938 can be stored in the remote memory storage device 962. It will be appreciated that the network connections shown are exemplary, and other means (e.g., wired or wireless) of establishing a communications link between the computers 902 and 960 can be used when carrying out an aspect of the present invention. In accordance with the practices of persons skilled in the art of computer programming, the present invention has been described with reference to acts and symbolic representations of operations that are performed by a computer, such as the computer 902 or remote computer 960, unless otherwise indicated. Such acts and operations are sometimes referred to as being computer-executed. It will be appreciated that the acts and symbolically represented operations include the manipulation by the processing unit 904 of electrical signals representing data bits which causes a resulting transformation or reduction of the electrical signal representation, and the maintenance of data bits at memory locations in the memory system (including the system memory 906, hard drive 916, floppy disks 920, CD-ROM 924, and remote memory 962) to thereby reconfigure or otherwise alter the computer system's operation, as well as other processing of signals. The memory locations where such data bits are maintained are physical locations that have particular electrical, magnetic, or optical properties corresponding to the data bits. FIG. 10 is another block diagram of a sample computing environment 1000 with which the present invention can interact. The system 1000 further illustrates a system that includes one or more client(s) 1002. The client(s) 1002 can be hardware and/or software (e.g., threads, processes, computing devices). The system 1000 also includes one or more server(s) 1004. The server(s) 1004 can also be hardware and/or software (e.g., threads, processes, computing devices). The server(s) 1004 can house threads to perform transformations by employing the present invention, for example. One possible communication between a client 1002 and a server 1004 may be in the form of a data packet adapted to be transmitted between two or more computer processes. The system 1000 includes a communication framework 1008 that can be employed to facilitate communications between the client(s) 1002 and the server(s) 1004. The client(s) 1002 are connected to one or more client data store(s) 1010 that can be employed to store information local to the client(s) 1002. Similarly, the server(s) 1004 are connected to one or more server data store(s) 1006 that can be employed to store information local to the server(s) 1004. In one instance of the present invention, a data packet transmitted between two or more computer components that facilitates equilibrium value determination is comprised of, at least in part, information relating to an equilibrium value determination system that utilizes, at least in part, demarcation of agent related data into buyer data and seller data to employ in a polynomial-time approximation method that generates an approximated equilibrium value for the system. It is to be appreciated that the systems and/or methods of the present invention can be utilized in equilibrium value determination facilitating computer components and non-computer related components alike. Further, those skilled in the art will recognize that the systems and/or methods of the present invention are employable in a vast array of electronic related technologies, including, but not limited to, computers, servers and/or handheld electronic devices, and the like. What has been described above includes examples of the present invention. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the present invention, but one of ordinary skill in the art may recognize that many further combinations and permutations of the present invention are possible. Accordingly, the present invention is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim. | <SOH> BACKGROUND OF THE INVENTION <EOH>Since the beginning of time, people have desired to obtain items that they did not possess. Often, to accomplish this, they gave something in return in order to obtain what they wanted. Thus, in effect, they were creating a “market” where goods and/or services could be traded. The trading for a particular good usually lasted until everyone who wanted that good obtained one. But, as is often the case, if the one who was supplying the good demanded more in return than what another wanted to give up, that other person left the market without that good. In spite of not getting that particular good, the person, however, was still satisfied because they felt that what they did have was better than the good they did not obtain. This is generally known as “buyer satisfaction.” In other words, buyers enter a marketplace and buy the items they need until the price of a particular item is more than they deem worthy for their own satisfaction. Satisfying a person tends to be a very individual trait; however, over a large number of people involved in a large market, the extreme differences settle out, leaving a general value or “price” of a good for that particular market. If the market price is too low, everyone will demand to have one, quickly depleting the supply of the good. However, if the price of the good is too high, the supply will remain high, with no trades taking place. Ideally, it is most desirable to have the supply equal the demand. Thus, as soon as a good is ready for market, it is quickly sold to someone who needs it. In this manner, a market is considered to be operating “efficiently” due to the supply equaling the demand. All buyers who desire a good at the market price are satisfied, while all sellers have sold their supplies, maximizing sales of their goods. This optimum market price, where supply equals demand, is known as a “market equilibrium price.” Because the market equilibrium price affords great benefits to both sellers and buyers in a market, it is very desirable to ascertain this price, especially for new goods entering a marketplace. A new supplier does not want to manufacture a high volume of goods if its manufacturing costs generate a product price that is too high to move the amount of goods. Likewise, if the new supplier attempts to sell below the market equilibrium price, the supplier will quickly run out of goods because the demand will far exceed the supply. Again, ideally, the supplier wants to produce the right number of goods at the market equilibrium price. Thus, the market equilibrium price becomes a very powerful business tool, foretelling product success or failure in the marketplace. For this reason, great efforts have been made to determine a market equilibrium price for a given good in a given market. Despite these efforts, it is still very difficult to produce a viable market equilibrium price. The amount of variables/factors involved with determining/defining a market are not inconsequential. Market data, such as number of buyers, number of sellers, value to a buyer, production costs, and even weather, play an important role in pricing of goods. Thus, market parameters must be modeled adequately to foretell a market equilibrium price. Accordingly, the behavior of a complex marketplace with multiple goods, buyers, and sellers, can only be understood by analyzing the system in its entirety. In practice, such markets tend toward a delicate balance of supply and demand as determined by the agents' fortunes and utilities. The study of this equilibrium situation is known as general equilibrium theory and was first formulated by Léon Walras in 1874 (see, Éléments d'économie politique pure; ou, Théorie de la richesse sociale ( Elements of Pure Economics, or the theory of social wealth ); Lausanne, Paris, 1874 (1899, 4 th ed.; 1926, rev. ed., 1954, Engl. transl.)). In the Walrasian model, the market consists of a set of agents, each with an initial endowment of goods, and a function describing the utility each one will derive from any allocation. The initial allocation could be sub-optimal, and the task of exchanging goods to mutually increase the utilities might be fairly complicated. A functioning market accomplishes this exchange by determining appropriate prices for the goods. Given these prices, all agents independently maximize their own utility by selling their endowments and buying the best bundle of goods they can afford. This new allocation will be an equilibrium allocation if the total demand for every good equals its supply. The prices that induce this equilibrium are called the market-clearing prices (or market equilibrium price), and the equilibrium itself is called a market equilibrium. Despite the better understanding of how a marketplace functions, modeling such a marketplace has proven extremely difficult. An agent is often both a buyer and a seller of goods. Satisfaction of a buyer can change dependent on many factors including how the buyer is doing as a seller (e.g., were enough goods sold so that the agent could function as a buyer of a good, etc.). Many variables that may seem trivial at first can have profound impact on a marketplace. Theoretical constructs that attempt to provide a basis for modeling the marketplace tend to be extremely complex for these reasons. The complexity often reaches a point where the basis for the model cannot even be resolved with today's fastest computers. Thus, even with the great technological advances in this century, the Walrasian model described in 1874 still cannot be effectively modeled. This leaves society without a means to maximize their markets, resulting in waste of not only manufactured goods, but also a waste of natural resources utilized in products brought to market. Thus, inefficient markets actually cause an increase in overall prices for goods and services. | <SOH> SUMMARY OF THE INVENTION <EOH>The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later. The present invention relates generally to computer modeling, and more particularly to systems and methods for modeling approximate equilibrium values for supply and demand systems. Demarcation of an agent into both a demander and a supplier is leveraged to provide a polynomial-time method of approximating a supply and demand system's equilibrium value. This provides, in one instance of the present invention, a simplified means to iteratively extract the equilibrium value. By providing demarcated data, the present invention accounts for both demand and supply effects of an agent within a modeled supply and demand system. In one instance of the present invention, a market equilibrium price vector is approximated by employing a revenue value generated for an agent in a current market equilibrium price iteration as a budget value for the agent in the next iteration. This permits market equilibrium value modeling that encompasses an agent's contributions to a market, both as a buyer and a seller within the same market for a given good and/or service. Thus, the present invention more accurately and precisely models an actual market within a polynomial-time constraint. To the accomplishment of the foregoing and related ends, certain illustrative aspects of the invention are described herein in connection with the following description and the annexed drawings. These aspects are indicative, however, of but a few of the various ways in which the principles of the invention may be employed and the present invention is intended to include all such aspects and their equivalents. Other advantages and novel features of the invention may become apparent from the following detailed description of the invention when considered in conjunction with the drawings. | 20040219 | 20100112 | 20050825 | 73436.0 | 0 | ERB, NATHAN | SYSTEMS AND METHODS FOR MODELING APPROXIMATE MARKET EQUILIBRIA | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,782,704 | ACCEPTED | Extrusion auger with removable auger segments and removal tool | There is provided an extrusion auger having auger segments that are removable from an auger shaft and that include a recess to facilitate removal of the auger segments. A pulling tool is also provided to engage the recess of the auger segment and to facilitate the removal of auger segment from the auger shaft in an axially forward direction. The auger segment includes an access way to provide access to the recess and the recess includes an engaging surface. The pulling tool includes a flanged end that can pass through the access way of the auger segment and contact the engaging surface of the auger segment. The recess of the auger segment may be located in a bore of the auger hub such that the pulling tool can be advanced along a keyway in the auger shaft, rotated to pass the flanged end of the pulling tool through the access way, and pulled axially forward to contact the engaging surface. | 1. An extrusion auger comprising one or more auger segments that are removable from an auger shaft in a forward direction along an axis of the auger shaft, wherein the removal is facilitated by a pulling tool, the auger segment comprising: an auger hub that includes a bore to engage the auger shaft and an outer surface opposite the bore, wherein the auger hub defines a forward end; at least a portion of a flight joined to the outer surface of the auger hub; and at least one engaging surface defined by the auger hub, the engaging surface having at least a portion thereof facing in a generally axial direction away from the forward end of the auger hub to allow the pulling tool to contact the engaging surface and thereby pull the auger segment along the axis of the auger shaft to facilitate removal of the auger segment from the auger shaft. 2. An extrusion auger according to claim 1, wherein the bore of the auger hub includes at least one keyway protrusion located radially inward of the bore for positioning in a keyway of the auger shaft. 3. An extrusion auger according to claim 2, wherein the engaging surface is axially located forward of the keyway protrusion. 4. An extrusion auger according to claim 2, wherein the keyway protrusion includes a radial surface and a bottom surface. 5. An extrusion auger according to claim 1, wherein the engaging surface is radially located between the bore and the outer surface of the auger hub. 6. An extrusion auger according to claim 1, wherein the engaging surface is generally perpendicular to the axis of the auger shaft. 7. An extrusion auger according to claim 1, wherein the auger hub includes two engaging surfaces that are symmetrically located at diametrical positions. 8. An extrusion auger comprising one or more auger segments that are removable from an auger shaft in a forward direction along an axis of the auger shaft, wherein the removal is facilitated by a pulling tool, the auger segment comprising: an auger hub that includes a bore to engage the auger shaft and an outer surface opposite the bore, wherein the auger hub defines a forward end; at least a portion of a flight joined to the outer surface of the auger hub; at least one recess in the forward end of the auger hub, wherein the recess includes an engaging surface; and an access way in the forward end of the auger hub to allow the pulling tool to contact the engaging surface through the access way and thereby pull the auger segment along the axis of the auger shaft to facilitate removal of the auger segment from the auger shaft. 9. An extrusion auger according to claim 8, wherein the bore of the auger hub includes at least one keyway protrusion located radially inward of the bore for positioning in a keyway of the auger shaft. 10. An extrusion auger according to claim 9, wherein the recess is axially located forward of the keyway protrusion. 11. An extrusion auger according to claim 9, wherein the keyway protrusion includes a radial surface and a bottom surface. 12. An extrusion auger according to claim 8, wherein the access way and the recess are radially located between the bore and the outer surface of the auger hub. 13. An extrusion auger according to claim 8, wherein the engaging surface is generally perpendicular to the axis of the auger shaft. 14. An extrusion auger according to claim 8, wherein the auger hub includes two recesses that are symmetrically located at diametrical positions. 15. An extrusion auger apparatus, comprising: an auger shaft having an axis; one or more auger segments comprising: an auger hub that includes a bore to engage the auger shaft and an outer surface opposite the bore, wherein the auger hub defines a forward end; at least a portion of a flight joined to the outer surface of the auger hub; and at least one engaging surface defined by the auger hub, the engaging surface having at least a portion thereof facing in a generally axial direction away from the forward end of the auger hub; and a pulling tool having a flanged end, wherein the flanged end of the pulling tool can contact the engaging surface to facilitate removal of the auger segment from the auger shaft in a forward direction along the axis of the auger shaft. 16. An extrusion auger apparatus according to claim 15, wherein the auger shaft includes a keyway and the bore of the auger hub includes at least one keyway protrusion for positioning in the keyway of the auger shaft. 17. An extrusion auger apparatus according to claim 16, wherein the engaging surface is axially located between the access way and the keyway protrusion. 18. An extrusion auger apparatus according to claim 16, wherein the keyway protrusion includes a radial surface and a bottom surface. 19. An extrusion auger apparatus according to claim 15, wherein the engaging surface is radially located between the bore and the outer surface of the auger hub. 20. An extrusion auger apparatus according to claim 15, wherein the engaging surface is generally perpendicular to the axis of the auger shaft. 21. An extrusion auger apparatus according to claim 15, wherein the auger hub includes two engaging surfaces that are symmetrically located at diametrical positions. 22. A pulling tool for removing an auger segment from an auger shaft of an extrusion auger in a forward direction along an axis of the auger shaft, the pulling tool comprising: a rod having a forward end, wherein the rod defines an outside surface; and a flanged end at an end of the rod opposite the forward end, the flanged end extending radially beyond the outside surface of the rod; wherein the flanged end is structured and arranged to contact an engaging surface of a recess of the auger segment to facilitate removal of the auger segment from the auger shaft. 23. A pulling tool according to claim 22, wherein the flanged end defines a contacting surface that contacts the engaging surface of the auger segment, wherein the contacting surface is generally perpendicular to the axis of the rod. 24. A method of removing an auger segment from an auger shaft of an extrusion auger in a forward direction along an axis of the auger shaft, the method comprising the steps of: advancing a pulling tool axially along the auger shaft; passing a flanged end of the pulling tool through an access way in the forward end of the auger segment; contacting a flanged end of the pulling tool with an engaging surface of a recess of the auger segment; and pulling the pulling tool to remove the auger segment from the auger shaft. 25. A method according to claim 24, wherein the passing step comprises the step of rotating the pulling tool so that the flanged end of the pulling tool passes through the access way. 26. A method according to claim 24, wherein the advancing step further comprises the steps of: positioning the pulling tool into a keyway of the auger shaft; and advancing the pulling tool axially along the keyway. | FIELD OF THE INVENTION The present invention relates generally to extrusion augers. More particularly the invention relates to an extrusion auger having one or more auger segments that are removable from an auger shaft in an axially forward direction. BACKGROUND OF THE INVENTION Many industries utilize extrusion augers to mix and/or extrude the process materials during the manufacturing of a product. An auger is essentially a shaft having a spiraled flight that rotates to push or pull the process material axially along the auger. The process material is predominately moved by the flight because of the screw-like movement of the flight. In some industries, such as the brick industry, constituents of the process materials are very hard and/or abrasive such that the flight is worn during extensive use. Damaged or worn flights may require replacement or refurbishment for efficient operation of the auger. Some extrusion augers include removable auger segments that provide for replacement of auger flights without replacing the entire auger. An auger segment consists of a hollow hub with a portion of the flight, such as a half or a complete revolution. The auger includes an auger shaft about which auger segments are axially attached along the auger shaft. When the auger segments are all attached, the auger defines at least one continuous flight. Auger segments with damaged or worn flight portions can be disposed of and replaced with new auger segments, or the auger segments can be refurbished for continued use. The auger shaft typically includes a feature to prevent the auger segments from rotating relative to the auger shaft and to exert rotational force during the operation of the extrusion auger. A keyway in the auger shaft and a corresponding key or protrusion in the bore of the auger segment is one example of such a feature. A keyway can also orient the flight portions of the auger segments such that the cumulative flight(s) define a continuous surface. Removal of the auger segments is often complicated by the process materials that pass between the auger segments during operation or by rust on the auger shaft and auger segments. The auger segments are removed axially and such debris and rust can complicate the removal of an auger segment by requiring additional force to overcome the debris, rust, or other impediments. In addition, some extruders provide limited access to the auger without major disassembly of the extruder. Thus the maintenance person who is removing the auger segments may have to pull the auger segments axially forward rather than pushing or prying the auger segments forward. Auger segments do not have components that are inherently conducive to gripping and pulling. Gripping the flight portion results in asymmetric application of the removal forces, which increases the forces required to remove the auger segment. Since the worn flight surfaces are polished and curved they are hard to grip thus increasing the risk of injury to the maintenance personnel. Therefore, a need exists for a convenient, cost effective, and safe procedure for removing auger segments from an auger shaft without damaging the auger segments. BRIEF SUMMARY OF THE INVENTION The invention addresses the above needs and achieves other advantages by providing an extrusion auger that includes one or more auger segments that are removable with a pulling tool. At least one recess having an engaging surface is provided in a forward end of the auger segment, particularly in the auger hub that engages the auger shaft. An access way in the forward end allows a pulling tool to enter the recess and to contact an engaging surface in the recess. Advantageously, the pulling tool is able to engage the recess by way of a preexisting keyway on the shaft. By exerting a force on the pulling tool, the auger segment can be axially removed from the auger shaft. In particular, the auger shaft includes a keyway and the auger segment includes a keyway protrusion that is positioned in the keyway of the auger shaft. The access way and recess may be axially located forward of the keyway protrusion such that the pulling tool may be advanced along the keyway and may be rotated such that a flanged end of the pulling tool passes through the access way to enter the recess so that it may contact the engaging surface of the auger segment. The engaging surface is generally perpendicular to the axis of the auger shaft. The auger segment may also include two or more recesses that are located symmetrically at diametrical positions. A pulling tool for removing an auger segment from an auger shaft is also provided by the present invention. The pulling tool includes a flanged end at one end of a rod, wherein the flanged end extends radially beyond an outside surface of the rod. The pulling tool may contact the engaging surface of the auger segment to facilitate removal of the auger segment from the auger shaft. Advantageously, the contacting surface of the flanged end is generally perpendicular to the axis of the rod. A method for removing an auger segment from an auger shaft is also provided. The pulling tool is advanced along the auger shaft and then the flanged end of the pulling tool is passed through the access way of the auger segment. The flanged end of the pulling tool contacts the engaging surface, and the pulling tool is pulled to remove the auger segment from the auger shaft. The method may also include rotating the pulling tool to pass the flanged end through the access way so that the flanged end is aligned with the engaging surface of the auger segment. The extrusion auger and pulling tool of the present invention may be manufactured in a cost-effective manner with relative ease. The recess of the auger segment provides a convenient surface for gripping the auger segment with the pulling tool, wherein the surface has sufficient structural strength to allow removal without damage to the auger segment. The pulling tool may be conveniently used to exert the pulling forces necessary to overcome the resistance created by the process material, rust, and other impediments. Therefore, the extrusion auger and pulling tool of the present invention provide for convenient safe removal of auger segments. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: FIG. 1 is a perspective view of an extrusion auger and pulling tool of the present invention, showing the pulling tool in the keyway of the auger shaft prior to the pulling tool contacting the auger segment; FIG. 2 is an end elevation view of the forward end of the extrusion auger of FIG. 1; FIG. 3 is a schematic, cross-sectional view taken along the line 3-3 of FIG. 2, showing a pulling tool on the top keyway prior to contacting the engaging surface of the auger segment and a pulling tool on the bottom keyway contacting the engaging surface of the auger segment; FIG. 4 is an enlarged end view of the extrusion auger of FIG. 1, showing a pulling tool in the keyway of the auger shaft prior to rotating the flanged end into the recess of the auger segment; FIG. 5 is an enlarged end view of the extrusion auger of FIG. 1, showing a pulling tool in the keyway of the auger shaft after rotating the flanged end into the recess of the auger segment; and FIG. 6 is an enlarged, cross-sectional view of the recess of the extrusion auger of FIG. 1, showing a pulling tool in the recess. DETAILED DESCRIPTION OF THE INVENTION The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout. With reference to FIGS. 1-6, an extrusion auger 10 in accordance with one embodiment of the present invention is illustrated. The extrusion auger 10 includes an auger shaft 12 about which one or more auger segments are removably attached. An auger segment 14 has an auger hub 16 that includes an auger bore 18 that engages the auger shaft 12. At least a portion of a flight 20 is joined to the outer surface 22 of the auger hub 16. The one or more auger segments 14 can be axially attached to the auger shaft 12 such that the portions of a flight 20 are aligned to define a continuous flight. An extrusion auger of further embodiments may have two or more continuous flights such that the auger segments 14 include two or more discrete portions of a flight 20. For example, an extrusion auger having two continuous flights would include auger segments that have portions of a flight that are preferably separated by 180 degrees. When assembling an extrusion auger 10 having one or more auger segments 14, the auger segments are axially attached to the auger shaft 12 such that an aft end 24 of a first auger segment 14 is positioned adjacent the aft end of the extrusion auger, and then a second auger segment 14 is axially advanced until the aft end 24 of the second auger segment engages a forward end 26 of the first auger segment. A third auger segment 14 is then axially advanced until the aft end 24 of the third auger segment engages a forward end 26 of the second auger segment and so forth until all the auger segments of the extension auger are attached. Sealants such as silicone or O-rings, to list two non-limiting examples, are preferably included between the engaging auger segments 14 to prevent or minimize the fine particles from the process material from contacting the auger shaft 12, which could inhibit the removal of an auger segment. The sealants also prevent the keyway of the auger shaft 12 from filling with constituents from the process material, which also inhibit the removal of the auger segment 14. The sealant may also prevent or minimize exposure of the auger shaft 12 to moisture that may create rust, which could further inhibit the removal of an auger segment. The attached auger segments 14 are angularly oriented such that the portion of a flight 20 of a first auger segment engages the portion of a flight 20 of a second auger segment to define a continuous surface of the spiraled flight. The continuous surface of the flight improves the efficiency of the extrusion auger 10 while in operation and reduces the wear on the engaging surfaces of the flight portions 20 during operation of the extrusion auger. As shown in FIG. 2, an auger segment 14 may be angularly oriented using a keyway protrusion 30 that corresponds to, and may be positioned in, a keyway 32 in the auger shaft 12. The keyway protrusion 30 of the auger segment 14 includes a generally radial surface 34 that engages a keyway radial surface 36 of the keyway 32. The keyway 32 is further defined by a bottom surface 38 that intersects the radial surface 36. The engagements between the radial surfaces 34 and 36 provide angular orientation to the auger segments 14 and can allow rotational force from the auger shaft 12 to be exerted on the auger segment during operation of the extrusion auger. FIG. 1 illustrates a pulling tool 50 of the present invention. The pulling tool 50 includes a rod 52 having a forward end (not shown) and defining an outside surface. The rod 52 of the pulling tool 50 may be of any length necessary to reach the auger segment 14 that is to be removed from the auger shaft 12. The rod 52 is preferably a cylindrical rod of high tensile steel, but the rod may be of any geometric shape or material suitable to remove an auger segment 14. The forward end may include a handle or other surface to facilitate gripping of the pulling tool 50 by an operator removing an auger segment 14. The end of the pulling tool 50 opposite the forward end is a flanged end 56 that projects radially beyond the outside surface of the rod 52 on at least one side of the rod. The flanged end 56 defines a contacting surface 58 that may be used to contact the auger segment 14 to facilitate removal of the auger segment. The flanged end 56 may comprise an eccentric end having one projection or may comprise an end having two or more projections. Referring to FIG. 3, the forward end 26 of the auger segment 14 includes an access way 60 that provides access to a recess 62 in the forward end. The access way 60 is an opening sufficiently sized for the flanged end 56 of the pulling tool 50 to pass through the access way and be axially located adjacent the recess 62. The access way 60 and recess 62 are preferably located radially inward of any sealant used between the auger segments 14 to prevent the ingress of the process material through the access way and into the recess. The access way 60 and recess 62 of the auger segment 14 of FIGS. 1-6 are axially forward of the keyway protrusion 30. Therefore, the pulling tool 50 may be advanced along the keyway 32 of the auger shaft 12, as shown in the top keyway of FIG. 3, until the pulling tool is positioned directly below, or radially inward of, the access way 60 and then the flanged end 56 is rotated into the recess 62, as shown in the bottom keyway of FIG. 3. The pulling tool 50 may be advanced along the shaft 12 at any location in further embodiments of the extrusion auger 10. The recess 62 is a hollow portion of the auger hub 16 that is radially located between the bore 18 and the outer surface 22 of the auger segment 14. The recess 62 may be of any cross-sectional configuration that would facilitate removal of the auger segment 14, and does not necessarily define an engaging surface 64 that extends purely radially, as is illustrated. The recess 62 defines an axial depth long enough to accommodate the flanged end 56 of the pulling tool 50 that will be used with the auger segment 14. The recess 62 also defines a radial depth sufficient to accommodate the flanged end 56 when the pulling tool 50 is rotated such that the contacting surface 58 is adjacent or contacts the engaging surface 64. The axially forward surface of the recess 62 defines the engaging surface 64 which may be contacted by the contacting surface 58 of the pulling tool 50 for axial removal of the auger segment 14 in the forward direction. The axial distance of the auger hub 16 between the engaging surface 64 and a forward face of the auger segment 14 must be of sufficient thickness and structural strength to withstand the force required to remove an auger segment that will be exerted through the pulling tool 50 onto the engaging surface 64. The amount of force required to remove an auger segment 14 varies with the materials used for the auger shaft 12 and the auger segment 14, with the relative diameters of the auger shaft and the bore 18, with the weight of the auger segment, and with the amount of debris, rust, or other process materials that are located on or near the auger shaft. The engaging surface 64 of FIG. 3 is one of the surfaces defining the recess 62; therefore, the engaging surface is also radially located between the bore 18 and the outer surface 22 of the auger hub 16. The engaging surface 64 is generally perpendicular to the axis of the auger shaft 12, though in further embodiments of the present invention the engaging surface may be oriented differently relative to the axis of the auger shaft. The engaging surface 64 preferably faces in a generally axial direction away from the forward end 26 of the auger hub to allow the pulling tool 50 to contact the engaging surface. Because the engaging surface 64 is defined in the forward end 26 of the auger hub 16, it axially faces the aft end 24 of the auger hub. The engaging surface 64 is contacted by the contacting surface 58 of the flanged end 56 of the pulling tool 50, and because the contacting surface is generally perpendicular to the axis of the rod, the contact between the contacting surface and the engaging surface is generally planar. After the flanged end 56 is positioned below the access way 60, as shown in FIG. 4, the pulling tool may be rotated approximately 90 degrees, as shown in FIG. 5, and pulled axially forward to contact the engaging surface 64. An alternative pulling tool may include a flanged end that is flexibly attached to the rod such that the flanged end is flexed toward the center of the rod as it passes through the access way 60 and returns to shape in the recess 62 to contact the engaging surface 64 without rotation of the pulling tool. Further embodiments of the pulling tool may contact the engaging surface 64 by additional techniques. The auger segment 14 includes two recesses that are symmetrically located at diametrical positions, as shown in FIG. 3. To pull the auger segment 14 axially forward, a pulling tool 50 is preferably inserted into each recess, and each engaging surface 64 is contacted by the contacting surface 58 of each pulling tool 50. To remove the auger segment 14, a pulling force is applied to each pulling tool 50 such that the pulling forces are generally equivalent. The generally equivalent pulling forces preferably maintain the alignment of the auger segment 14 with the auger shaft 12 during removal to prevent or minimize binding or resistance to removal caused by a misaligned auger segment. Alternatively, an auger segment 14 may be removed with only one pulling tool 50 or with three or more pulling tools corresponding with three or more engaging surfaces 64. To attach the auger segments 14 to the auger shaft 12 prior to first use of the extrusion auger 10 or after the removal of auger segments, the auger segment may be axially pushed in the aft direction with any suitable tool, including, but not limited to, the flanged end 56 of the pulling tool 50. The pulling tool of the present invention may be manufactured using any suitable process, including but not limited to extrusion, welding, or forging, and using any suitable material, including but not limited to high tensile steel. To manufacture the auger segments of the present invention to include the access ways and recesses, materials and manufacturing processes known in the art may be utilized. The access ways and recesses of the various embodiments may be included in the molds used to cast the auger segments, or the access ways and recesses may be machined into the auger segments subsequent to casting or forging of the auger segments. Many modifications and other embodiments of the invention set forth herein will come to mind to one skilled in the art to which the invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. | <SOH> BACKGROUND OF THE INVENTION <EOH>Many industries utilize extrusion augers to mix and/or extrude the process materials during the manufacturing of a product. An auger is essentially a shaft having a spiraled flight that rotates to push or pull the process material axially along the auger. The process material is predominately moved by the flight because of the screw-like movement of the flight. In some industries, such as the brick industry, constituents of the process materials are very hard and/or abrasive such that the flight is worn during extensive use. Damaged or worn flights may require replacement or refurbishment for efficient operation of the auger. Some extrusion augers include removable auger segments that provide for replacement of auger flights without replacing the entire auger. An auger segment consists of a hollow hub with a portion of the flight, such as a half or a complete revolution. The auger includes an auger shaft about which auger segments are axially attached along the auger shaft. When the auger segments are all attached, the auger defines at least one continuous flight. Auger segments with damaged or worn flight portions can be disposed of and replaced with new auger segments, or the auger segments can be refurbished for continued use. The auger shaft typically includes a feature to prevent the auger segments from rotating relative to the auger shaft and to exert rotational force during the operation of the extrusion auger. A keyway in the auger shaft and a corresponding key or protrusion in the bore of the auger segment is one example of such a feature. A keyway can also orient the flight portions of the auger segments such that the cumulative flight(s) define a continuous surface. Removal of the auger segments is often complicated by the process materials that pass between the auger segments during operation or by rust on the auger shaft and auger segments. The auger segments are removed axially and such debris and rust can complicate the removal of an auger segment by requiring additional force to overcome the debris, rust, or other impediments. In addition, some extruders provide limited access to the auger without major disassembly of the extruder. Thus the maintenance person who is removing the auger segments may have to pull the auger segments axially forward rather than pushing or prying the auger segments forward. Auger segments do not have components that are inherently conducive to gripping and pulling. Gripping the flight portion results in asymmetric application of the removal forces, which increases the forces required to remove the auger segment. Since the worn flight surfaces are polished and curved they are hard to grip thus increasing the risk of injury to the maintenance personnel. Therefore, a need exists for a convenient, cost effective, and safe procedure for removing auger segments from an auger shaft without damaging the auger segments. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>The invention addresses the above needs and achieves other advantages by providing an extrusion auger that includes one or more auger segments that are removable with a pulling tool. At least one recess having an engaging surface is provided in a forward end of the auger segment, particularly in the auger hub that engages the auger shaft. An access way in the forward end allows a pulling tool to enter the recess and to contact an engaging surface in the recess. Advantageously, the pulling tool is able to engage the recess by way of a preexisting keyway on the shaft. By exerting a force on the pulling tool, the auger segment can be axially removed from the auger shaft. In particular, the auger shaft includes a keyway and the auger segment includes a keyway protrusion that is positioned in the keyway of the auger shaft. The access way and recess may be axially located forward of the keyway protrusion such that the pulling tool may be advanced along the keyway and may be rotated such that a flanged end of the pulling tool passes through the access way to enter the recess so that it may contact the engaging surface of the auger segment. The engaging surface is generally perpendicular to the axis of the auger shaft. The auger segment may also include two or more recesses that are located symmetrically at diametrical positions. A pulling tool for removing an auger segment from an auger shaft is also provided by the present invention. The pulling tool includes a flanged end at one end of a rod, wherein the flanged end extends radially beyond an outside surface of the rod. The pulling tool may contact the engaging surface of the auger segment to facilitate removal of the auger segment from the auger shaft. Advantageously, the contacting surface of the flanged end is generally perpendicular to the axis of the rod. A method for removing an auger segment from an auger shaft is also provided. The pulling tool is advanced along the auger shaft and then the flanged end of the pulling tool is passed through the access way of the auger segment. The flanged end of the pulling tool contacts the engaging surface, and the pulling tool is pulled to remove the auger segment from the auger shaft. The method may also include rotating the pulling tool to pass the flanged end through the access way so that the flanged end is aligned with the engaging surface of the auger segment. The extrusion auger and pulling tool of the present invention may be manufactured in a cost-effective manner with relative ease. The recess of the auger segment provides a convenient surface for gripping the auger segment with the pulling tool, wherein the surface has sufficient structural strength to allow removal without damage to the auger segment. The pulling tool may be conveniently used to exert the pulling forces necessary to overcome the resistance created by the process material, rust, and other impediments. Therefore, the extrusion auger and pulling tool of the present invention provide for convenient safe removal of auger segments. | 20040219 | 20070320 | 20050825 | 92575.0 | 0 | SOOHOO, TONY GLEN | EXTRUSION AUGER WITH REMOVABLE AUGER SEGMENTS AND REMOVAL TOOL | SMALL | 0 | ACCEPTED | 2,004 |
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10,782,845 | ACCEPTED | Apparatus for homogeneously distributing lights | An apparatus for homogeneously distributing lights includes a light guide plate, an incidence microstructure and an emergence microstructure. The incidence microstructure is arranged on a surface of the light guide plate and opposite to a light source. The emergence microstructure is arranged on a surface of the light guide plate opposite to the incidence microstructure. The lights emitted by the light source pass through said apparatus thereby being homogenously distributed. Thus the manufacture costs are lowered, and the light source utilization ratio is increased. | 1. An apparatus for homogeneously distributing lights, comprising: a light guide plate; an incidence microstructure being arranged on a surface of the light guide plate and opposite to a light source; and an emergence microstructure, the emergence microstructure being arranged on a surface of the light guide plate opposite to the incidence microstructure; wherein the lights emitted by the light source pass through said apparatus thereby being homogenously distributed. 2. The apparatus as claimed in claim 1, wherein the incidence microstructure is a continuous structure or a discontinuous structure having a triangle cross-section and longitudinally arranged along the light source. 3. The apparatus as claimed in claim 1, wherein the emergence microstructure is a continuous structure or a discontinuous structure having a triangle cross-section and longitudinally arranged along the light source. 4. The apparatus as claimed in claim 1, wherein the emergence microstructure is a micro lens array structure. 5. The apparatus as claimed in claim 4, wherein the micro lens array structure is a structure selected from the groups consisting of honeycombed structure, circular dot structure and irregular structure. 6. The apparatus as claimed in claim 1, wherein the light source is a plurality of lamp. 7. The apparatus as claimed in claim 1, wherein the light guide plate is made of one of a light transmitting polymer material and a semi light transmitting polymer material. 8. The apparatus as claimed in claim 1, wherein the apparatus is applied to a backlight module of an LCD panel. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to an apparatus for homogeneously distributing lights, and more particularly, to an apparatus for homogeneously distributing lights applied to a direct type backlight module. 2. Description of the Related Art Large-scale liquid crystal display (LCD) is mainly applied to a notebook computer or an LCD monitor. Liquid crystal material does not emit light itself. Therefore an external light source is needed for displaying images. Because of a trend of light, thin, short and small styles of a light source of a backlight module, and a requirement for being applied to a large-scale panel, such as an LCD television (TV), the backlight module is not only supposed to have the above-mentioned advantages, but also have other advantages, such as high display luminance, broad visual angle, distinct image contrast and long life. Therefore, direct type backlight module, which is designed for solving the limitations of low luminance in lateral sides thereof and unhomogeneously distribution of the lights, when used in large-scale panels, takes full advantage of its high display luminance to apply direct type linear light source for homogeneously distributing the lights; converts the homogeneous lights into area lights; and imports the area lights to the illumination area. General light source of direct type backlight module is cold cathode fluorescernt lamp (CCFL) or light emitting diode (LED). The CCFL has properties like high brightness, high efficiency and long life, and has a cylinder-shaped configuration which is easily coupled with light reflection components to form laminal lighting device. Therefore the CCFL has become the mainstream light emergence component. However, CCFLs are often arranged in a row and disposed at a bottom of an LCD panel, thereby the images displayed on the LCD are asymmetric in light intensity distribution because the diffusion angles of the scattered lights are usually too large, and the light emergence directions are usually disordered. Thus obvious profiles of the CCFLs are shown on the screen, which damage the quality of the images. Therefore, under the circumstance of direct type backlight module being applied, the larger of the dimension of the LCD panel and the greater of the number of the CCFLs are used, the more serious of the deficiency of black and white stripes shown on the screen occurs. The above mentioned problem is a main bottle-neck in the way of the development of the LCD display quality. To solve the above mentioned problem, diffusion components and prisms are disposed between the CCFLs and the LCD panel to diffuse and then converge the lights. Therefore the lights emitted by the CCFLs are diffused, and then the diffusion angle is reduced for being efficiently coupled with the LCD panel, thereby homogeneously distributing the lights. However, the above design applies so many optical components as to not easy to be manufactured, and sharply increase the costs. Furthermore, the effect of homogeneously distributing the lights of the design is finite, and not the best solution to solve the problem. Referring to FIG. 6, U.S. Pat. No. 6,280,063 discloses a multi-layer brightness enhancement article 60 for enhancing the on-axis luminance of a diffuse lighting device. The brightness enhancement article 60 comprises a base layer 61, a separate layer 62 plated on the a bottom of the base layer 61, and a microstructure layer 63 arranged on a side of the base layer 61 opposite to the separate layer 62. The separate layer 62 is used for diffusing the lights. The microstructure layer 63 is used for converging the diffused lights. By using the separate layer 62 and the microstructure layer 63, the lights are homogeneously distributing. However, different processes are required in this invention for respectively forming the separate layer 62 and the microstructure layer 63, thereby increasing the manufacture costs. Furthermore, the processes are complicated and not suitable for mass production, and the effect of homogeneously distributing the lights can not satisfy the images quality requirements of consumers. Referring to FIG. 7, U.S. Pub. No. 20020001055 discloses a backlight module structure 70, which applies resin particles to form a light diffusion layer 71. The light diffusion layer 71 diffuses the lights emitted by a backlight source 72 with wide-angle. A prism sheet 73 then converges the lights to achieve an effect of homogeneous diffusion. However, the backlight module structure 70 comprises so many components that leads to a complicated manufacture process and increases the manufacture costs. Furthermore, the homogeneous diffusion effect and the efficiency of the light utilization can not satisfy the market demands. Additionally, conventional method also increases the number and the arrangement density of the CCFLs to solve the problems of unhomogeneously distributing the lights and of the profiles of the CCFLs being shown on the screen. However, the method greatly increases the manufacture costs. Furthermore, because of the configure limitation, if any one of the CCFLs failures, the whole row of CCFLs will be replaced with a new one. Under the circumstance of the number of the CCFLs being increased, the chance and frequency of CCFL failure and replace are correspondingly increased. Thus the service life of the whole LCD panel is shortened. Thus an improved apparatus applied in the direct type backlight module for homogeneously distributing the lights, efficiently utilizing the light source, greatly lowering the manufacture costs and meeting the demands of the market is desired. SUMMARY OF THE INVENTION The primary objective of the present invention is to provide an apparatus for homogeneously distributing lights, which efficiently controls the light emergence direction and homogeneously distributing the lights. Another objective of the present invention is to provide an apparatus for homogeneously distributing lights, which improves the light source utilization ratio. A further objective of the present invention is to provide an apparatus for homogeneously distributing lights, which applies fewer optical films, and cuts down the manufacture costs. And yet another objective of the present invention is to provide an apparatus for homogeneously distributing lights, which is suitable for mass production. In accordance with the above and other objectives, the present invention proposes an apparatus for homogeneously distributing lights. The apparatus includes a light guide plate, an incidence microstructure and an emergence microstructure. The incidence microstructure is arranged on a surface of the light guide plate and opposite to a light source. The emergence microstructure is arranged on a surface of the light guide plate opposite to the incidence microstructure. The lights emitted by the light source pass through said apparatus thereby being homogenously distributed. The apparatus can be applied to a backlight module of a liquid crystal display (LCD) panel. The incidence microstructure and emergence microstructure are manufactured by ultra-precision machining or micro-electro-mechanical system (MEMS). The incidence microstructure or emergence microstructure is one of the continuous and discontinuous honeycombed, circular, irregular or circular dot structure, or of a micro lens array structure, or any one of said structure incorporating a plurality of micro particles. The guide light plate having a refractive index greater than the outside environment is made of a light transmitting polymer material and semi light transmitting polymer material. The light source is a plurality of parallel cold cathode fluorescernt lamps (CCFLs). The emergence microstructure of the emergence surface is designed for damaging total reflection of the lights in the light guide plate, thereby the lights experienced at least one time total reflection pass through the emergence surface where does not correspond to the light source, and emit to the outside environment environment. Thus the directions of the lights passing through the incidence microstructure of the incidence surface are changed, accordingly, the lights are homogeneously distributed, and further the light source utilization ratio is increased. BRIEF DESCRIPTION OF THE DRAWINGS The drawings included herein provide a further understanding of the invention. A brief description of the drawings is as follows: FIGS. 1A and 1B are schematic views of an apparatus for homogeneously distributing lights applied in a backlight module in accordance with a preferred embodiment of the present invention; FIG. 2 is a schematic view of light passages of the apparatus of FIGS. 1A and 1B; FIG. 3A is a light intensity distribution chart of a conventional backlight module; FIG. 3B is a light intensity distribution chart of the backlight module applying the apparatus of FIG. 1A and/or FIG. 1B; FIG. 4 is an alternative embodiment of the apparatus for homogeneously distributing lights of the present invention; FIG. 5 is still an alternative embodiment of the apparatus for homogeneously distributing lights of the present invention; FIG. 6 is a schematic view of a conventional multi-layer brightness enhancement article disclosed in U.S. Pat. No. 6,280,063; and FIG. 7 is a schematic view of a conventional backlight module structure disclosed in U.S. Pub. No. 20020001055. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Embodiments of an apparatus for homogeneously distributing lights 1 (this is referred to simply as “apparatus”) of the present invention will now be explained in detail with reference to the drawings. Referring to FIGS. 1A and 1B, schematic views of the apparatus 1 applied in a backlight module in accordance with a preferred embodiment of the present invention are shown, wherein the FIG. 1B is a side view of the FIG. 1A. The apparatus 1 is disposed on a surface of a main body of a backlight module 5. The backlight module 5 comprises a plurality of parallel cold cathode fluorescernt lamps (CCFLs) 20. The apparatus 1 comprises a light guide plate 10. The light guide plate 10 comprises an incidence surface 11 and an emergence surface 15. The incidence surface 11 is arranged opposite to the CCFLs 20. Lights emitted by the CCFLs 20 subsequently pass through the incidence surface 11, the main body of the light guide plate 10 and the emergence surface 15, and then emit to an adjacent liquid crystal display (LCD) panel (not shown) for displaying images. The incidence surface 11 and the emergence surface 15 respectively define a plurality of interlaced first areas 12 and second areas 13. The first areas 12 of the incidence surface 11 and the emergence surface 15 correspond to the CCFLs 20. The second areas 13 of the incidence surface 11 and the emergence surface 15 correspond to the spaces sandwiched between the CCFLs 20. Each first area 12 defines an incidence microstructure 30. Each second area 13 defines an emergence microstructure 45. When the lights emitted by the CCFLs 20 pass through the incidence microstructure 30 and enter the light guide plate 10, the lights are scattered with wide-angle, thereby occurring total reflection in the light guide plate 10. After at least one time total reflection in the light guide plate 10, the lights emit to the outside environment through the emergence microstructures 35. That is, by applying the incidence microstructures 30 and the emergence microstructures 35, the lights emitted by the CCFLs 20 are not only emitted through the first areas 12 of the emergence surface 15, but also through the second areas 13 of the emergence surface 15 to the outside environment. Thus the lights generates by the CCFLs 20 are homogeneously distributed. More specifically, the light guide plate 10 is made of transparent polymer material having a low light absorbency, or of light transmitting polymer material, or 5 alternately of semi light transmitting polymer material. Said materials have a refractive index greater than that of the outside environment (such as the air) where the CCFLs 20 locate, thereby increasing the chance for occurring total reflection inside the light guide plate 10. The thickness of the light guide plate 10 (i.e. the distance from the incidence surface 11 to the emergence surface 15) can be adjusted according to the requirement and design. In a backlight module, the thickness of the light guide plate 10 is usually in a millimeter (mm) scale. The incidence microstructures 30 and the emergence microstructures 35 are manufactured by ultra-precision machining or micro-electro-mechanical system (MEMS). In the present embodiment, the section view of the incidence microstructure 30 or the emergence microstructure 35 is a longitudinally arranged continuous zigzag structure having a triangle section along the CCFLs 20. The configuration of the incidence microstructure 30 or the emergence microstructure 35 can be designed as a circular structure, a circular dot structure, or an irregular structure; or the angle, height, arrangement density or the like thereof can be various according to different specifications or requirements; or a plurality of micro particles can be mixed therein. Therefore, the passages of the lights are changed for improving the total reflection condition of the light guide plate 10. Chance for occurring total reflection is increased because the incidence angles of the lights entering into the light guide plate 10 through the incidence microstructure 30 are more likely greater than the corresponding critical angle. Consequently, by properly choosing the material and the refractive index of the light guide plate 10, and the location and configuration of the incidence microstructures 30, the probability for the incidence lights occurring total reflection is greatly increased. Furthermore, by properly choosing the location and configuration of the emergence microstructures 35, the probability for the lights entering into outside environment through the second areas 13 of the emergence surface 15 is greatly increased. Referring to FIG. 2, passages of the lights emitted by the CCFLs 20 are further illustrated (illustrated with the lights emitted form only one CCFL). The lights pass through the incidence microstructure 30 of the first area 12 of the incidence surface 11, and enter into the light guide plate 10. Part of the lights occur total reflection in the light guide plate 10, and transmit along the light guide plate 10. Said lights occurring total reflection then pass through the emergence microstructure 35 which breaches the total reflection condition of the light guide plate 10, and then emitted to the outside environment through the second area 13 of the emergence surface 15. Therefore, the lights emitted from the first area 12 of the emergence surface 15 are greatly decreased, and the lights emitted from the second area 13 of the emergence surface 15 are correspondingly greatly increased. Thus the lights emitted from the whole light guide plate 10 are homogeneously distributed, the deficiency of profiles of the CCFLs 20 shown on the LCD screen of prior arts is eliminated. Referring to FIG. 3A, a light intensity distribution chart of the CCFLs of conventional backlight module is illustrated. As can be seen, the light intensity is unhomogeneously distributed. Referring to FIG. 3B, a light intensity distribution chart of the CCFLs of present invention is illustrated. As can be seen, compared with FIG. 3A, the light intensity is substantially homogeneously distributed. By applying the incidence microstructures 30 and the emergence microstructures 35 to the light guide plate 10, the light energy density emitted through the first areas 12 of the emergence surface 15 is greatly decreased, and correspondingly, the light energy density emitted through the second areas 13 of the emergence surface 15 is greatly increased, thereby forming the light intensity distribution shown in FIG. 3B. The apparatus 1 of the present invention is thus homogeneously distributing the lights, simultaneously, the light source utilization ratio is increased, the manufacture processes are simplified, and the manufacture costs are lowered. The foregoing detail description is only a preferred embodiment of the present invention, in which, the incidence microstructures 30 and emergence microstructures 35 are designed as a continuous shape. However, other structures which can achieve an effect of light diffusion or light total reflection also can be applied to the present invention, the best dimension and designed configuration of the structure can be various in accordance with the specification of the backlight module and the LCD panel, or of the distance from the plurality of CCFLs 20 to the light guide plate 10. Additionally, the feature of the present invention is that the first areas12 of the incidence surface 11 of the light guide 10 define the incidence microstructures30 for occurring total reflection, whether or not the emergence microstructures 35 are defined in the emergence surface 15 does not enormously influence the effect of lights homogeneously distributed. Besides the embodiments disclosed above, other embodiments, such as the emergence surface 15 defines the emergence microstructures 35 in all the areas thereof, or the emergence surface 15 does not define the emergence microstructures 35 therein, can also be applied in the present invention. Referring to FIG. 4, an alternate embodiment of an incidence microstructure 40 (corresponding to the incidence microstructure 30) and an emergence microstructure 45 (corresponding to the emergence microstructure 35) of the present invention is illustrated. The incidence microstructure 40 and emergence microstructure 45 are designed as discontinuous microstructures, and defined in the first areas 12 of the incidence surface 11 and the second areas 13 of the emergence surface 15 by MEMS. The incidence microstructure 40 or emergence microstructure 45 comprises a plurality of evenly spaced teeth for changing the critical angle of total reflection of the lights entering the light guide plate 10, and further for homogeneously distributing the lights. FIG. 5 illustrates another alternate embodiment of an emergence microstructure 50 of the present invention. The emergence microstructure 50 is an uninterrupted micro lens array which is arranged on the emergence surface 15 for changing the condition of total reflection of the lights entering the light guide plate 10, and further for homogeneously distributing the lights. The emergence microstructure 50 can be shaped as one of the honeycombed structure, circular dot structure and irregular structure, or any one of said structure incorporating micro particles. The above embodiments of the apparatus 1 are described as being applied to a direct type backlight module, whereas the apparatus 1 can also be applied to other device whose lights emitted from a light source need to be guided or distributed to other structures. Furthermore, the light source of the present invention is not limited as the CCFLs 20, but can be any type of light source whose lights directions can be controlled by various incidence microstructures or emergence microstructures. Conclusively, the apparatus 1 of the present invention can homogeneously distribute lights, improve light source utilization ratio; reduce the usage of optical films, lower the manufacture costs and be applied to mass production. It should be apparent to those skilled in the art that the above description is only illustrative of specific embodiments and examples of the invention. The invention should therefore cover various modifications and variations made to the herein-described structure and operations of the invention, provided they fall within the scope of the invention as defined in the following appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates generally to an apparatus for homogeneously distributing lights, and more particularly, to an apparatus for homogeneously distributing lights applied to a direct type backlight module. 2. Description of the Related Art Large-scale liquid crystal display (LCD) is mainly applied to a notebook computer or an LCD monitor. Liquid crystal material does not emit light itself. Therefore an external light source is needed for displaying images. Because of a trend of light, thin, short and small styles of a light source of a backlight module, and a requirement for being applied to a large-scale panel, such as an LCD television (TV), the backlight module is not only supposed to have the above-mentioned advantages, but also have other advantages, such as high display luminance, broad visual angle, distinct image contrast and long life. Therefore, direct type backlight module, which is designed for solving the limitations of low luminance in lateral sides thereof and unhomogeneously distribution of the lights, when used in large-scale panels, takes full advantage of its high display luminance to apply direct type linear light source for homogeneously distributing the lights; converts the homogeneous lights into area lights; and imports the area lights to the illumination area. General light source of direct type backlight module is cold cathode fluorescernt lamp (CCFL) or light emitting diode (LED). The CCFL has properties like high brightness, high efficiency and long life, and has a cylinder-shaped configuration which is easily coupled with light reflection components to form laminal lighting device. Therefore the CCFL has become the mainstream light emergence component. However, CCFLs are often arranged in a row and disposed at a bottom of an LCD panel, thereby the images displayed on the LCD are asymmetric in light intensity distribution because the diffusion angles of the scattered lights are usually too large, and the light emergence directions are usually disordered. Thus obvious profiles of the CCFLs are shown on the screen, which damage the quality of the images. Therefore, under the circumstance of direct type backlight module being applied, the larger of the dimension of the LCD panel and the greater of the number of the CCFLs are used, the more serious of the deficiency of black and white stripes shown on the screen occurs. The above mentioned problem is a main bottle-neck in the way of the development of the LCD display quality. To solve the above mentioned problem, diffusion components and prisms are disposed between the CCFLs and the LCD panel to diffuse and then converge the lights. Therefore the lights emitted by the CCFLs are diffused, and then the diffusion angle is reduced for being efficiently coupled with the LCD panel, thereby homogeneously distributing the lights. However, the above design applies so many optical components as to not easy to be manufactured, and sharply increase the costs. Furthermore, the effect of homogeneously distributing the lights of the design is finite, and not the best solution to solve the problem. Referring to FIG. 6 , U.S. Pat. No. 6,280,063 discloses a multi-layer brightness enhancement article 60 for enhancing the on-axis luminance of a diffuse lighting device. The brightness enhancement article 60 comprises a base layer 61 , a separate layer 62 plated on the a bottom of the base layer 61 , and a microstructure layer 63 arranged on a side of the base layer 61 opposite to the separate layer 62 . The separate layer 62 is used for diffusing the lights. The microstructure layer 63 is used for converging the diffused lights. By using the separate layer 62 and the microstructure layer 63 , the lights are homogeneously distributing. However, different processes are required in this invention for respectively forming the separate layer 62 and the microstructure layer 63 , thereby increasing the manufacture costs. Furthermore, the processes are complicated and not suitable for mass production, and the effect of homogeneously distributing the lights can not satisfy the images quality requirements of consumers. Referring to FIG. 7 , U.S. Pub. No. 20020001055 discloses a backlight module structure 70 , which applies resin particles to form a light diffusion layer 71 . The light diffusion layer 71 diffuses the lights emitted by a backlight source 72 with wide-angle. A prism sheet 73 then converges the lights to achieve an effect of homogeneous diffusion. However, the backlight module structure 70 comprises so many components that leads to a complicated manufacture process and increases the manufacture costs. Furthermore, the homogeneous diffusion effect and the efficiency of the light utilization can not satisfy the market demands. Additionally, conventional method also increases the number and the arrangement density of the CCFLs to solve the problems of unhomogeneously distributing the lights and of the profiles of the CCFLs being shown on the screen. However, the method greatly increases the manufacture costs. Furthermore, because of the configure limitation, if any one of the CCFLs failures, the whole row of CCFLs will be replaced with a new one. Under the circumstance of the number of the CCFLs being increased, the chance and frequency of CCFL failure and replace are correspondingly increased. Thus the service life of the whole LCD panel is shortened. Thus an improved apparatus applied in the direct type backlight module for homogeneously distributing the lights, efficiently utilizing the light source, greatly lowering the manufacture costs and meeting the demands of the market is desired. | <SOH> SUMMARY OF THE INVENTION <EOH>The primary objective of the present invention is to provide an apparatus for homogeneously distributing lights, which efficiently controls the light emergence direction and homogeneously distributing the lights. Another objective of the present invention is to provide an apparatus for homogeneously distributing lights, which improves the light source utilization ratio. A further objective of the present invention is to provide an apparatus for homogeneously distributing lights, which applies fewer optical films, and cuts down the manufacture costs. And yet another objective of the present invention is to provide an apparatus for homogeneously distributing lights, which is suitable for mass production. In accordance with the above and other objectives, the present invention proposes an apparatus for homogeneously distributing lights. The apparatus includes a light guide plate, an incidence microstructure and an emergence microstructure. The incidence microstructure is arranged on a surface of the light guide plate and opposite to a light source. The emergence microstructure is arranged on a surface of the light guide plate opposite to the incidence microstructure. The lights emitted by the light source pass through said apparatus thereby being homogenously distributed. The apparatus can be applied to a backlight module of a liquid crystal display (LCD) panel. The incidence microstructure and emergence microstructure are manufactured by ultra-precision machining or micro-electro-mechanical system (MEMS). The incidence microstructure or emergence microstructure is one of the continuous and discontinuous honeycombed, circular, irregular or circular dot structure, or of a micro lens array structure, or any one of said structure incorporating a plurality of micro particles. The guide light plate having a refractive index greater than the outside environment is made of a light transmitting polymer material and semi light transmitting polymer material. The light source is a plurality of parallel cold cathode fluorescernt lamps (CCFLs). The emergence microstructure of the emergence surface is designed for damaging total reflection of the lights in the light guide plate, thereby the lights experienced at least one time total reflection pass through the emergence surface where does not correspond to the light source, and emit to the outside environment environment. Thus the directions of the lights passing through the incidence microstructure of the incidence surface are changed, accordingly, the lights are homogeneously distributed, and further the light source utilization ratio is increased. | 20040223 | 20061024 | 20050616 | 98727.0 | 3 | SEMBER, THOMAS M | APPARATUS FOR HOMOGENEOUSLY DISTRIBUTING LIGHTS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,783,002 | ACCEPTED | Computer-implemented method, system and program product for comparing application program interfaces (APIs) between Java byte code releases | Under the present invention, source input corresponding to a first release of Java byte code and target input corresponding to a second release of the Java byte code is received. The input is transformed into a first list containing class names associated with the first release and a second list containing class names associated with the second release. Thereafter, any classes corresponding to class names that appear on both lists (e.g., matching class names) are loaded. The methods within the matching classes are then compared to determine if any of the APIs have been modified between the two releases. After the comparison, the matching class names are removed from the lists. Any class names remaining on the first list represent APIs that have been removed for the second release, while any class names remaining on the second list represent APIs that have been added for the second release. | 1. A computer-implemented method for comparing Application Program Interfaces (APIs) between Java byte code releases, comprising: receiving source input corresponding to a first release of Java byte code and target input corresponding to a second release of the Java byte code; transforming the source input into a first list that contains Java class names associated with the first release of Java byte code, and the target input into a second list containing Java class names associated with the second release of the Java byte code; finding matching class names between the first list and the second list, and loading classes corresponding to the matching class names; comparing the loaded classes to identify APIs that have been modified between the first release of Java byte code and the second release of the Java byte code; and removing the matching class names from the first list and the second list after the comparing, wherein any class names remaining in the first list represent APIs that have been removed for the second release of the Java byte code, and wherein any class names remaining in the second list represent APIs that have been added for the second release of the Java byte code. 2. The method of claim 1, further comprising outputting a report identifying at least one of the APIs that have been modified, the APIs that have been removed and the APIs that have been added. 3. The method of claim 1, wherein the loading step comprises loading at least one Java class of the first release of Java byte code and at least one Java class of the second release of the Java byte code. 4. The method of claim 3, further comprising listing methods of the at least one Java class of the first release of Java byte code in the first list, and listing methods of the at least one Java class of the second release of the Java byte code in the second list. 5. The method of claim 4, wherein the comparing step comprises comparing the methods in the first list to the methods in the second list to identify APIs that have been modified between the first release of Java byte code and the second release of the Java byte code. 6. The method of claim 5, wherein the removing step comprises removing, from the first list and the second list, any methods in the first list that are identical to methods in the second list based on the comparison, wherein any methods remaining in the first list after the removing represent APIs that have been removed for the second release of the Java byte code, and wherein any methods remaining in the second list after the removing represent APIs that have been added for the second release of the Java byte code. 7. The method of claim 1, wherein the source input and the target input comprise JAR files. 8. The method of claim 1, wherein the source input and the target input comprise a list of classes. 9. The method of claim 1, further comprising inputting class paths common to the first release of Java byte code and the second release of the Java byte code. 10. A system for comparing Application Program Interfaces (APIs) between Java byte code releases, comprising: an input system for receiving source input corresponding to a first release of Java byte code and target input corresponding to a second release of the Java byte code; a transformation system for transforming the source input into a first list that contains Java class names associated with the first release of Java byte code, and the target input into a second list containing Java class names associated with the second release of the Java byte code; a class matching system for finding matching class names between the first list and the second list; a class comparison system for comparing classes corresponding to the matching class names to identify APIs that have been modified between the first release of Java byte code and the second release of the Java byte code; and a removal system for removing the matching class names from the first list and the second list after the comparison, wherein any class names remaining in the first list represent APIs that have been removed for the second release of the Java byte code, and wherein any class names remaining in the second list represent APIs that have been added for the second release of the Java byte code. 11. The system of claim 10, further comprising a report generation system for generating a report identifying at least one of the APIs that have been modified, the APIs that have been removed and the APIs that have been added. 12. The system of claim 10, further comprising a class loader for loading at least one Java class of the first release of Java byte code and at least one Java class of the second release of the Java byte code. 13. The system of claim 12, further comprising a method listing system for listing methods of the at least one Java class of the first release of Java byte code in the first list, and for listing methods of the at least one Java class of the second release of the Java byte code in the second list. 14. The system of claim 13, wherein the class comparison system compares the methods in the first list to the methods in the second list to identify APIs that have been modified between the first release of Java byte code and the second release of the Java byte code. 15. The system of claim 14, wherein the removal system removes, from the first list and the second list, any methods in the first list that are identical to methods in the second list based on the comparison, wherein any methods remaining in the first list after the removing represent APIs that have been removed for the second release of the Java byte code, and wherein any methods remaining in the second list after the removing represent APIs that have been added for the second release of the Java byte code. 16. The system of claim 10, wherein the source input and the target input comprise JAR files. 17. The system of claim 10, wherein the source input and the target input comprise a list of classes. 18. The system of claim 10, wherein the input system further receives class paths common to the first release of Java byte code and the second release of the Java byte code. 19. A program product stored on a recordable medium for comparing Application Program Interfaces (APIs) between Java byte code releases, which when executed, comprises: program code for receiving source input corresponding to a first release of Java byte code and target input corresponding to a second release of the Java byte code; program code for transforming the source input into a first list that contains Java class names associated with the first release of Java byte code, and the target input into a second list containing Java class names associated with the second release of the Java byte code; program code for finding matching class names between the first list and the second list; program code for comparing classes corresponding to the matching class names to identify APIs that have been modified between the first release of Java byte code and the second release of the Java byte code; and program code for removing the matching class names from the first list and the second list after the comparison, wherein any class names remaining in the first list represent APIs that have been removed for the second release of the Java byte code, and wherein any class names remaining in the second list represent APIs that have been added for the second release of the Java byte code. 20. The program product of claim 19, further comprising program code for generating a report identifying at least one of the APIs that have been modified, the APIs that have been removed and the APIs that have been added. 21. The program product of claim 19, further comprising program code for loading at least one Java class of the first release of Java byte code and at least one Java class of the second release of the Java byte code. 22. The program product of claim 21, further comprising program code for listing methods of the at least one Java class of the first release of Java byte code in the first list, and for listing methods of the at least one Java class of the second release of the Java byte code in the second list. 23. The program product of claim 22, wherein the program code for comparing compares the methods in the first list to the methods in the second list to identify APIs that have been modified between the first release of Java byte code and the second release of the Java byte code. 24. The program product of claim 23, wherein the program code for removing removes, from the first list and the second list, any methods in the first list that are identical to methods in the second list based on the comparison, wherein any methods remaining in the first list after the removing represent APIs that have been removed for the second release of the Java byte code, and wherein any methods remaining in the second list after the removing represent APIs that have been added for the second release of the Java byte code. 25. The program product of claim 19, wherein the source input and the target input comprise JAR files. 26. The program product of claim 19, wherein the source input and the target input comprise a list of classes. 27. The program product of claim 19, wherein the program code for receiving further receives class paths common to the first release of Java byte code and the second release of the Java byte code. | BACKGROUND OF THE INVENTION 1. Field of the Invention In general, the present invention provides a computer-implemented method, system and program product for comparing Application Program Interfaces (APIs) between Java byte code releases. Specifically, the present invention provides an accurate and efficient way to determine any API differences between two releases of Java byte code. 2. Related Art As the use of the Java programming language becomes more prevalent, many new software products are being developed in Java. In many instances, a software product will have multiple releases or versions. One major problem with having multiple releases is maintaining backward compatibility so that new releases can support the functionality of previous releases. Between two Software Development Kit (SDK) releases, the problem would be to maintain backward compatibility of Application Program Interfaces (APIs). As known, an API is the specific method by which a programmer writing an application program can make requests of an operating system or another application. In general, an API can be contrasted with a graphical user interface or a command interface (both of which are direct user interfaces) as interfaces to an operating system or a program. When developing APIs, a developer will often use a modeling tool such as the Rational modeling tool, which is commercially available from International Business Machines, Corp. of Armonk, N.Y. Rational allows a developer to define a model using Unified Modeling Language (UML), and automatically generate APIs based thereon. To date, many solutions have been proposed for determining the difference between two software releases. None of these proposed solutions, however, provides a way to determine the API differences between two releases of Java byte code. Specifically, under the Java programming language, Java code is first developed and then later compiled into binary or byte code (e.g., by a Java Virtual Machine), which represents the final “deliverable” to the customer. Existing solutions determine the differences between two releases using the uncompiled Java code. This is usually performed either by manually parsing the Java code, or by using a utility that references comments inserted by developers during the development process. However, manually determining the differences requires both a great deal of manpower and time. Moreover, relying on developer comments assumes that all necessary comments have been inserted. Since it is very easy for a developer to forget to insert a comment, there is a high likelihood that API differences between releases will go unnoticed. Still yet, because the uncompiled Java code does not represent the final “deliverable” to the customer, there is no way to ensure complete accuracy in the analysis. In view of the foregoing, there exists a need for a computer-implemented method, system and program product for comparing Application Program Interfaces (APIs) between Java byte code releases. That is, a need exists for a way to determine the changes made to the APIs of two releases of Java byte code. To this extent, a need exists for any classes in common to both releases to be compared to determine if any APIs were modified between the two releases. Still yet, a need exists for classes added to, or removed from the second release (with respect to the first release) to be identified. SUMMARY OF THE INVENTION In general, the present invention provides a computer-implemented method, system and program product for comparing Application Program Interfaces (APIs) between Java byte code releases. Specifically, under the present invention, source input corresponding to a first release of Java byte code and target input corresponding to a second release of the Java byte code is received. The input is transformed into a first list containing class names associated with the first release and a second list containing class names associated with the second release. Thereafter, any classes corresponding to class names that appear on both lists (e.g., matching class names) are loaded. The methods within the matching classes are then compared to determine if any of the APIs have been modified between the two releases. After the comparison, the matching class names are removed from the lists. Any class names remaining on the first list represent APIs that have been removed for the second release, while any class names remaining on the second list represent APIs that have been added for the second release. A first aspect of the present invention provides a computer-implemented method for comparing Application Program Interfaces (APIs) between Java byte code releases, comprising: receiving source input corresponding to a first release of Java byte code and target input corresponding to a second release of the Java byte code; transforming the source input into a first list that contains Java class names associated with the first release of Java byte code, and the target input into a second list containing Java class names associated with the second release of the Java byte code; finding matching class names between the first list and the second list, and loading classes corresponding to the matching class names; comparing the loaded classes to identify APIs that have been modified between the first release of Java byte code and the second release of the Java byte code; and removing the matching class names from the first list and the second list after the comparing, wherein any class names remaining in the first list represent APIs that have been removed for the second release of the Java byte code, and wherein any class names remaining in the second list represent APIs that have been added for the second release of the Java byte code. A second aspect of the present invention provides a system for comparing Application Program Interfaces (APIs) between Java byte code releases, comprising: an input system for receiving source input corresponding to a first release of Java byte code and target input corresponding to a second release of the Java byte code; a transformation system for transforming the source input into a first list that contains Java class names associated with the first release of Java byte code, and the target input into a second list containing Java class names associated with the second release of the Java byte code; a class matching system for finding matching class names between the first list and the second list; a class comparison system for comparing classes corresponding to the matching class names to identify APIs that have been modified between the first release of Java byte code and the second release of the Java byte code; and a removal system for removing the matching class names from the first list and the second list after the comparison, wherein any class names remaining in the first list represent APIs that have been removed for the second release of the Java byte code, and wherein any class names remaining in the second list represent APIs that have been added for the second release of the Java byte code. A third aspect of the present invention provides a program product stored on a recordable medium for comparing Application Program Interfaces (APIs) between Java byte code releases, which when executed, comprises: program code for receiving source input corresponding to a first release of Java byte code and target input corresponding to a second release of the Java byte code; program code for transforming the source input into a first list that contains Java class names associated with the first release of Java byte code, and the target input into a second list containing Java class names associated with the second release of the Java byte code; program code for finding matching class names between the first list and the second list; program code for comparing classes corresponding to the matching class names to identify APIs that have been modified between the first release of Java byte code and the second release of the Java byte code; and program code for removing the matching class names from the first list and the second list after the comparison, wherein any class names remaining in the first list represent APIs that have been removed for the second release of the Java byte code, and wherein any class names remaining in the second list represent APIs that have been added for the second release of the Java byte code. Therefore, the present invention provides a computer-implemented method, system and program product for comparing Application Program Interfaces (APIs) between Java byte code releases. BRIEF DESCRIPTION OF THE DRAWINGS These and other features of this invention will be more readily understood from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings in which: FIG. 1 depicts an illustrative system for comparing Application Program Interfaces (APIs) between Java byte code releases according to the present invention. FIG. 2 depicts a flow diagram of a first illustrative method for comparing APIs according to the present invention. FIG. 3 depicts a flow diagram of an illustrative method for comparing Java classes according to the present invention. FIG. 4 depicts a flow diagram of a second illustrative method for comparing APIs according to the present invention. It is noted that the drawings of the invention are not necessarily to scale. The drawings are merely schematic representations, not intended to portray specific parameters of the invention. The drawings are intended to depict only typical embodiments of the invention, and therefore should not be considered as limiting the scope of the invention. In the drawings, like numbering represents like elements. DETAILED DESCRIPTION OF THE DRAWINGS For convenience purposes, the Detailed Description of the Drawings will have the following Sections: I. General Description II. Definitions III. Computerized Implementation I. General Description As indicated above, the present invention provides a computer-implemented method, system and program product for comparing Application Program Interfaces (APIs) between Java byte code releases. Specifically, under the present invention, source input corresponding to a first release of Java byte code and target input corresponding to a second release of the Java byte code is received. The input is transformed into a first list containing class names associated with the first release and a second list containing class names associated with the second release. Thereafter, any classes corresponding to class names that appear on both lists (e.g., matching class names) are loaded. The methods within the matching classes are then compared to determine if any of the APIs have been modified between the two releases. After the comparison, the matching class names are removed from the lists. Any class names remaining on the first list represent APIs that have been removed for the second release, while any class names remaining on the second list represent APIs that have been added for the second release. II. Definitions The details of the Java programming language are well known to those of ordinary skill in the art and will not be described in detail herein. However, for clarity purposes, the following terms have the following meanings: A “class” is a template definition of the methods and variables in a particular kind of object. An object is a specific instance of a class that contains real values instead of variables. To this extent, a class can have subclasses that can inherit all or some of the characteristic of the class. A “method” is a programmed procedure that is defined as part of a class and included in any object of that class. A class can have more than one method, and as single method, can be reused in multiple objects. A “Java Archive file (JAR file)” is a file that contains the class(es), image(s) and sound file(s) for a Java program gathered into a single file. A “Java Virtual Machine (JVM)” is an implementation of the Java Virtual Machine Specification that compiles Java code into byte code or binary code and interprets the compiled code for a computer's processor so that it can perform a Java program's instructions. Java was designed to allow application programs to be built that could be run on any platform without having to be rewritten or recompiled by the programmer for each separate platform. A Java virtual machine makes this possible because it is aware of the specific instruction lengths and other particularities of the platform. III. Computerized Implementation Referring now to FIG. 1, a system 10 for comparing APIs of Java byte code releases is shown. As depicted, system 10 includes computer system 12, which generally comprises central processing unit (CPU) 20, memory 22, bus 24, input/output (I/O) interfaces 26, external devices/resources 28 and storage unit 30. CPU 20 may comprise a single processing unit, or be distributed across one or more processing units in one or more locations, e.g., on a client and server. Memory 22 may comprise any known type of data storage and/or transmission media, including magnetic media, optical media, random access memory (RAM), read-only memory (ROM), a data cache, etc. Moreover, similar to CPU 20, memory 22 may reside at a single physical location, comprising one or more types of data storage, or be distributed across a plurality of physical systems in various forms. I/O interfaces 26 may comprise any system for exchanging information to/from an external source. External devices/resources 28 may comprise any known type of external device, including speakers, a CRT, LCD screen, handheld device, keyboard, mouse, voice recognition system, speech output system, printer, monitor/display, facsimile, pager, etc. Bus 24 provides a communication link between each of the components in computer system 12 and likewise may comprise any known type of transmission link, including electrical, optical, wireless, etc. Storage unit 30 can be any system (e.g., database) capable of providing storage for information under the present invention. Such information could include, for example, lists 62A-C, byte code releases, etc. As such, storage unit 30 could include one or more storage devices, such as a magnetic disk drive or an optical disk drive. In another embodiment, storage unit 30 includes data distributed across, for example, a local area network (LAN), wide area network (WAN) or a storage area network (SAN) (not shown). Although not shown, additional components, such as cache memory, communication systems, system software, etc., may be incorporated into computer system 12. Shown in memory 22 of computer system 12 is API system 32 (shown as a program product). As will be further described below, API system 32 facilitates the comparison of APIs between first release of (Java) byte code 14B and second release of (Java) byte code 16B. Specifically, under the present invention, a developer or the like (not shown) will provide uncompiled first release of Java code 14A and uncompiled second release of Java code 16A to computer system 12. As known in the art, compiler 50 within Java Virtual Machine 48 will compile the uncompiled releases 14A and 16A into compiled releases of byte code 14B and 16B, respectively. It should be understood that first release 14A-B and second release 16A-B are intended to be subsequent releases of the same software program. Moreover, it should be understood that Java Virtual Machine 48 will likely include other components not shown in FIG. 1. Such components should be understood to exist by those of ordinary skill in the art. In any event, once compiled into first and second releases of byte code 14B and 16B, API system 32 can make an API comparison there between. As depicted, API system 32 includes input system 34, transformation system 36, class matching system 38, method listing system 40, class comparison system 42, removal system 44 and report generation system 46. It should be understood that each of these systems includes program code/logic for carrying out the functions described herein. Moreover, it should be understood that API system 32 could reside within an existing modeling tool such as Rational (as discussed above). To this extent, the present invention could be embodied as a modification to any modeling tool now know or later developed. Regardless, for the comparison to be performed under the present invention, the developer will provide some basic input. To this extent, as shown, the developer will first provide common class paths for uncompiled first release 14A and uncompiled second release 16A of Java code. Specifically, it could be the case that a class within the releases 14A and/or 16A references another class outside of the releases 14A and/or 16A. Providing the common class paths 54 ensures that such classes can be located. The developer will also provide source input 56 corresponding to uncompiled first release 14A and target input 58 corresponding to uncompiled second release 16A. Source input 56 and target input 58 can be a list of classes, one or more jar files, or the like. In any event, the class paths 54, source input 56 and target input 58 will be received by input system 34 (and possibly stored in storage unit 30). Upon receipt, transformation system 36 will transform source input 56 and target input 58 into two lists 62A-B of Java class names along with their loading information. Specifically, transformation system 36 will transform source input 56 into a first list 62A of class names and target input 58 into a second list 62B of class names. Once listed in this manner, class matching system 38 will attempt to find class names that appear on both lists 62A-B (i.e., matching class names). Assume, for example, that class matching system 38 found one class name (e.g., class name “X”) that appeared on both lists 62A-B. In this event, class loader 52 within Java Virtual Machine 48 would then load the classes corresponding thereto from first release of byte code 14B and second release of byte code 16B. So for example, class loader 52 might load classes “A,” “B,” and “C” from each release of byte code 14B and 16B. Once loaded, method listing system 40 will list the methods of the loaded classes on first list 62A and second list 62B, respectively (or on other lists not shown). At this point, the loaded classes will be compared by class comparison system 42. Specifically, the methods of the loaded classes of first release of byte code 14B will be compared to the corresponding methods of the loaded classes of second release of byte code 16B to determine if any APIs have been modified between first release of byte code 14B and second release of byte code 16B. For example, if the methods of class “A” differed between first release of byte code 14B and second release of byte code 16B, then the API(s) associated with class “A” would be determined to have been modified. In general, a method is considered the same between the two releases if it maintains the same name, parameter order and types, and return types. If any of these elements differ between the two releases, then the method and class is determined to be different and the resulting API(s) modified. In such a case, an entry identifying the modified classes and/or APIs can be made on a “modified API” list 62C. After the comparison is made, the compared methods and the class name corresponding thereto (e.g., class name “X”) will be removed from both lists 62A-B . The process would then be repeated for any other matching class names (although in this example only one class name appeared on both lists 62A-B). Once all matching class names have undergone the comparison process and been removed from lists 62A-B, it can be determined whether API(s) have been added or removed between first release of byte code 14B and second release of byte code 16B. Specifically, any class names remaining in first list 62A will not be present in second list 62B, and therefore represent APIs that have been removed for second release of byte code 16B. Conversely, any class names remaining in second list 62B will not be present in first list 62A, and therefore represent APIs that have been added for second release of byte code 16B. Once the added, removed and/or modified APIs have been identified, report generation system 46 can generate and output a report 60 of the results. Under the present invention, report generation system 46 has the capability to filter the results so that only selected results are outputted. For example, a developer might only desire to see the APIs that have been modified. Accordingly, the report 60 can identify at least one of the added APIs, the removed APIs and/or the modified APIs. Referring to FIGS. 2-4, flow diagrams are depicted to further describe the teachings of the present invention. Specifically, referring first to FIG. 2, the method as described above is depicted. As shown, first step S1 of method 100 is to receive common class paths. Second step S2 is to receive the source input corresponding to the first release of byte code and the target input corresponding to the second release of byte code. As indicated above, the input can be a list of classes, one or more jar files or the like. In step S3, the source input and the target input are transformed into a first and second list of class names associated with the first and second releases of byte code, respectively. In step S4, the classes corresponding to any matching class names (i.e., class names that exist in both lists) are loaded. Once loaded the classes are compared in step S5. Referring briefly to FIG. 3, the comparison operation of step S5 is shown in greater detail. Specifically, first step C1 of comparison method 200 is to load the classes of the matching class name. Second step C2 is to list the methods of the loaded classes. Third step C3 is to compare the listed methods. Fourth step C4 is to then remove the methods from the lists after the comparison. Returning back to FIG. 2, once the comparison method 200 of FIG. 3 has been completed, the class name corresponding to the classes compared in step S5 will be removed from the first and second lists in step S6. In step S7 it is determined if any other matching class names remain. If so, the process is repeated from step S4 for the next matching class name. If not, the process will be ended in step S8. It should be appreciated that the present invention need not be limited to the source input and target input being a list of classes. For example, referring to FIG. 4, a method 300 is depicted whereby the source input and the target input comprises one or more jar files. Specifically, as shown, step J1 is to receive at least one source jar file and at least one target jar file. In step J2, the input jar files will be transformed into two lists of class names (as indicated in FIG. 2). In step J3, matching class names will be identified from the lists, and in step J4, the classes corresponding to the matching class names will be loaded. In step J5, the classes will be compared as described in conjunction with FIG. 3 After the comparison, the matching class name will be removed from the lists in step J6. Similar to method 100 of FIG. 2, the process will be repeated for all matching class names. Once all matching class names have been removed from the lists, the process can end. It should be understood that the teachings described herein could be implemented on a stand-alone computer system 12 as shown in FIG. 1, or over a network in a client-server environment. In the case of the latter, the client and server could communicate over any type of network such as the Internet, a local area network (LAN), a wide area network (WAN), a virtual private network (VPN), etc. As such, communication between the client and server could occur via a direct hardwired connection (e.g., serial port), or via an addressable connection that may utilize any combination of wireline and/or wireless transmission methods. Moreover, conventional network connectivity, such as Token Ring, Ethernet, WiFi or other conventional communications standards could be used. Still yet, connectivity could be provided by conventional TCP/IP sockets-based protocol. In this instance, the client could utilize an Internet service provider to establish connectivity to the server. It should also be understood that the present invention can be realized in hardware, software, or a combination of hardware and software. Any kind of computer system(s)—or other apparatus adapted for carrying out the methods described herein—is suited. A typical combination of hardware and software could be a general purpose computer system with a computer program that, when loaded and executed, carries out the respective methods described herein. Alternatively, a specific use computer, containing specialized hardware for carrying out one or more of the functional tasks of the invention, could be utilized. The present invention can also be embedded in a computer program product, which comprises all the respective features enabling the implementation of the methods described herein, and which—when loaded in a computer system—is able to carry out these methods. Computer program, software program, program, or software, in the present context mean any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following: (a) conversion to another language, code or notation; and/or (b) reproduction in a different material form. The foregoing description of the preferred embodiments of this invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously, many modifications and variations are possible. Such modifications and variations that may be apparent to a person skilled in the art are intended to be included within the scope of this invention as defined by the accompanying claims. For example, the illustrative representation of API system 32 shown in FIG. 1 is not intended to be limiting. That is, the functions of the present invention described herein could be represented by a different configuration of systems. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention In general, the present invention provides a computer-implemented method, system and program product for comparing Application Program Interfaces (APIs) between Java byte code releases. Specifically, the present invention provides an accurate and efficient way to determine any API differences between two releases of Java byte code. 2. Related Art As the use of the Java programming language becomes more prevalent, many new software products are being developed in Java. In many instances, a software product will have multiple releases or versions. One major problem with having multiple releases is maintaining backward compatibility so that new releases can support the functionality of previous releases. Between two Software Development Kit (SDK) releases, the problem would be to maintain backward compatibility of Application Program Interfaces (APIs). As known, an API is the specific method by which a programmer writing an application program can make requests of an operating system or another application. In general, an API can be contrasted with a graphical user interface or a command interface (both of which are direct user interfaces) as interfaces to an operating system or a program. When developing APIs, a developer will often use a modeling tool such as the Rational modeling tool, which is commercially available from International Business Machines, Corp. of Armonk, N.Y. Rational allows a developer to define a model using Unified Modeling Language (UML), and automatically generate APIs based thereon. To date, many solutions have been proposed for determining the difference between two software releases. None of these proposed solutions, however, provides a way to determine the API differences between two releases of Java byte code. Specifically, under the Java programming language, Java code is first developed and then later compiled into binary or byte code (e.g., by a Java Virtual Machine), which represents the final “deliverable” to the customer. Existing solutions determine the differences between two releases using the uncompiled Java code. This is usually performed either by manually parsing the Java code, or by using a utility that references comments inserted by developers during the development process. However, manually determining the differences requires both a great deal of manpower and time. Moreover, relying on developer comments assumes that all necessary comments have been inserted. Since it is very easy for a developer to forget to insert a comment, there is a high likelihood that API differences between releases will go unnoticed. Still yet, because the uncompiled Java code does not represent the final “deliverable” to the customer, there is no way to ensure complete accuracy in the analysis. In view of the foregoing, there exists a need for a computer-implemented method, system and program product for comparing Application Program Interfaces (APIs) between Java byte code releases. That is, a need exists for a way to determine the changes made to the APIs of two releases of Java byte code. To this extent, a need exists for any classes in common to both releases to be compared to determine if any APIs were modified between the two releases. Still yet, a need exists for classes added to, or removed from the second release (with respect to the first release) to be identified. | <SOH> SUMMARY OF THE INVENTION <EOH>In general, the present invention provides a computer-implemented method, system and program product for comparing Application Program Interfaces (APIs) between Java byte code releases. Specifically, under the present invention, source input corresponding to a first release of Java byte code and target input corresponding to a second release of the Java byte code is received. The input is transformed into a first list containing class names associated with the first release and a second list containing class names associated with the second release. Thereafter, any classes corresponding to class names that appear on both lists (e.g., matching class names) are loaded. The methods within the matching classes are then compared to determine if any of the APIs have been modified between the two releases. After the comparison, the matching class names are removed from the lists. Any class names remaining on the first list represent APIs that have been removed for the second release, while any class names remaining on the second list represent APIs that have been added for the second release. A first aspect of the present invention provides a computer-implemented method for comparing Application Program Interfaces (APIs) between Java byte code releases, comprising: receiving source input corresponding to a first release of Java byte code and target input corresponding to a second release of the Java byte code; transforming the source input into a first list that contains Java class names associated with the first release of Java byte code, and the target input into a second list containing Java class names associated with the second release of the Java byte code; finding matching class names between the first list and the second list, and loading classes corresponding to the matching class names; comparing the loaded classes to identify APIs that have been modified between the first release of Java byte code and the second release of the Java byte code; and removing the matching class names from the first list and the second list after the comparing, wherein any class names remaining in the first list represent APIs that have been removed for the second release of the Java byte code, and wherein any class names remaining in the second list represent APIs that have been added for the second release of the Java byte code. A second aspect of the present invention provides a system for comparing Application Program Interfaces (APIs) between Java byte code releases, comprising: an input system for receiving source input corresponding to a first release of Java byte code and target input corresponding to a second release of the Java byte code; a transformation system for transforming the source input into a first list that contains Java class names associated with the first release of Java byte code, and the target input into a second list containing Java class names associated with the second release of the Java byte code; a class matching system for finding matching class names between the first list and the second list; a class comparison system for comparing classes corresponding to the matching class names to identify APIs that have been modified between the first release of Java byte code and the second release of the Java byte code; and a removal system for removing the matching class names from the first list and the second list after the comparison, wherein any class names remaining in the first list represent APIs that have been removed for the second release of the Java byte code, and wherein any class names remaining in the second list represent APIs that have been added for the second release of the Java byte code. A third aspect of the present invention provides a program product stored on a recordable medium for comparing Application Program Interfaces (APIs) between Java byte code releases, which when executed, comprises: program code for receiving source input corresponding to a first release of Java byte code and target input corresponding to a second release of the Java byte code; program code for transforming the source input into a first list that contains Java class names associated with the first release of Java byte code, and the target input into a second list containing Java class names associated with the second release of the Java byte code; program code for finding matching class names between the first list and the second list; program code for comparing classes corresponding to the matching class names to identify APIs that have been modified between the first release of Java byte code and the second release of the Java byte code; and program code for removing the matching class names from the first list and the second list after the comparison, wherein any class names remaining in the first list represent APIs that have been removed for the second release of the Java byte code, and wherein any class names remaining in the second list represent APIs that have been added for the second release of the Java byte code. Therefore, the present invention provides a computer-implemented method, system and program product for comparing Application Program Interfaces (APIs) between Java byte code releases. | 20040220 | 20100518 | 20050825 | 94847.0 | 0 | CHEN, QING | COMPUTER-IMPLEMENTED METHOD, SYSTEM AND PROGRAM PRODUCT FOR COMPARING APPLICATION PROGRAM INTERFACES (APIS) BETWEEN JAVA BYTE CODE RELEASES | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,783,024 | ACCEPTED | Solid formulations of ospemifene | This invention relates to a solid drug formulation comprising granulates containing a therapeutically active compound of the formula (I) or a geometric isomer, a stereoisomer, a pharmaceutically acceptable salt, an ester thereof or a metabolite thereof, in combination with one or more intra-granular excipients. | 1. A solid drug formulation comprising granulates containing a therapeutically active compound of the formula (I) or a geometric isomer, a stereoisomer, a pharmaceutically acceptable salt, an ester thereof or a metabolite thereof, in combination with one or more intra-granular excipients. 2. The drug formulation according to claim 1 wherein compound (I) is ospemifene. 3. The drug formulation according to claim 1 wherein at least one intra-granular excipient is a disintegrant. 4. The drug formulation according to claim 1 wherein at least one intra-granular excipient is a diluent. 5. The drug formulation according to claim 1 wherein at least one intra-granular excipient is a binder. 6. The drug formulation according to claim 1 wherein the intra-granular excipient is a combination of at least one diluent and at least one binder; a combination at least one diluent and at least one disintegrant; a combination of at least one disintegrant and at least one binder; or a combination of at least one diluent, at least one disintegrant and at least one binder. 7. The drug formulation according to claim 3 wherein the disintegrant is selected from the group consisting of povidone, crospovidone, carboxymethylcellulose, methylcellulose, alginic acid, croscarmellose sodium, sodium starch glycolate, starch, formaldehyde-casein and combinations thereof. 8. The drug formulation according to claim 4 wherein the diluent is selected from the group consisting of maltose, maltodextrin, lactose, fructose, dextrin, microcrystalline cellulose, pregelatinized starch, sorbitol, sucrose, silicified microcrystalline cellulose, powdered cellulose, dextrates, mannitol, calsium phospate and combinations thereof. 9. The drug formulation according to claim 5 wherein the binder is selected from a group consisting of acacia, dextrin, starch, povidone, carboxymethylcellulose, guar gum, glucose, hydroxypropyl methylcellulose, methylcellulose, polymethacrylates, maltodextrin, hydroxyethyl cellulose and combinations thereof. 10. The drug formulation according to claim 1 wherein the granulates are made by dry granulation. 11. The drug formulation according to claim 1 wherein the granulates are made by wet granulation. 12. The drug formulation according to claim 1 wherein the formulation is a capsule comprising the granulates encapsulated in a shell. 13. The drug formulation according to claim 12 wherein the formulation comprises an extra-granular lubricant. 14. The drug formulation according to claim 13 wherein the lubricant is selected from the group consisting of calcium stearate, magnesium stearate, stearic acid, talc, a vegetable oil, poloxamer, a mineral oil, sodium lauryl sulphate, sodium stearyl filmarate, zinc stearate and combinations thereof. 15. The drug formulation according to claim 1, wherein the formulation is a tablet comprising the granulates in combination with one or more extra-granular excipient. 16. The drug formulation according to claim 15, wherein the extra-granular excipient is selected from the group consisting of one or more disintegrants, one or more diluents, one or more binders, one or more lubricants, and their combinations. 17. The drug formulation according to claim 16, where the extra-granular disintegrant is selected from the group consisting of povidone, crospovidone, carboxymethylcellulose, methylcellulose, alginic acid, croscarmellose sodium, sodium starch glycolate, starch, formaldehyde-casein and combinations thereof. 18. The drug formulation according to claim 16, where the extra-granular diluent is selected from the group consisting of maltose, maltodextrin, lactose, fructose, dextrin, microcrystalline cellulose, pregelatinized starch, sorbitol, sucrose, silicified microcrystalline cellulose, powdered cellulose, dextrates, mannitol, calsium phospate and combinations thereof. 19. The drug formulation according to claim 16 wherein the extra-granular binder is selected from a group consisting of acacia, dextrin, starch, povidone, carboxymethylcellulose, guar gum, glucose, hydroxypropyl methylcellulose, methylcellulose, polymethacrylates, maltodextrin, hydroxyethyl cellulose and combinations thereof. 20. The drug formulation according to claim 16 wherein the extra-granular lubricant is selected from the group consisting of calcium stearate, magnesium stearate, stearic acid, talc, a vegetable oil, poloxamer, a mineral oil, sodium laurul sulphate, sodium stearly fumarate, zinc stearate and combinations thereof. 21. The drug formulation according to claim 2 wherein 90% of the drug substance has a particle size less than 250 micrometer. 22. The drug formulation according to claim 21 wherein 90% of the drug substance has a particle size less than 150 micrometer and 50% of the drug substance has a particle size less than 25 micrometer. 23. The drug formulation according to claim 22 wherein 90% of the drug substance has a particle size less than 50 micrometer and 50% of the drug substance has a particle size less than 15 micrometer. | FIELD OF THE INVENTION This invention relates to a solid drug formulation comprising granulates containing ospemifene or a closely related compound. BACKGROUND OF THE INVENTION The publications and other materials used herein to illuminate the background of the invention, and in particular, cases to provide additional details respecting the practice, are incorporated by reference. “SERM”s (selective estrogen receptor modulators) have both estrogen-like and antiestrogenic properties (Kauffman & Bryant, 1995). The effects may be tissue-specific as in the case of tamoxifen and toremifene which have estrogen-like effects in the bone, partial estrogen-like effect in the uterus and liver, and pure antiestrogenic effect in breast cancer. Raloxifene and droloxifen are similar to tamoxifen and toremifene, except that their antiestrogenic properties dominate. Based on the published information, many SERMs are more likely to cause menopausal symptoms than to prevent them. They have, however, other important benefits in elderly women: they decrease total and LDL cholesterol, thus deminishing the risk of cardiovascular diseases, and they may prevent osteoporosis and inhibit breast cancer growth in postmenopausal women. There are also almost pure antiestrogens under development. Ospemifene is the Z-isomer of the compound of formula (I) and it is one of the main metabolites of toremifene, is known to be an estrogen agonist and antagonist (Kangas, 1990; International patent publications WO 96/07402 and WO 97/32574). The compound is also called (deaminohydroxy)toremifene and it is also known under the code FC-1271a. Ospemifene has relatively weak estrogenic and antiestrogenic effects in the classical hormonal tests (Kangas, 1990). It has anti-osteoporosis actions and it decreases total and LDL cholesterol levels in both experimental models and in human volunteers (International patent publications WO 96/07402 and WO 97/32574). It also has antitumor activity in an early stage of breast cancer development in an animal breast cancer model. Ospemifene is also the first SERM which has been shown to have beneficial effects in climacteric syndromes in healthy women. The use of ospemifene for the treatment of certain climacteric disorders in postmenopausal women, namely vaginal dryness and sexual dysfunction, is disclosed in WO 02/07718. The published patent application WO 03/103649 describes the use of ospemifene for inhibition of atrophy and for the treatment or prevention of atrophy-related diseases or disorders in women, especially in women during or after the menopause. OBJECT AND SUMMARY OF THE INVENTION An object of the present invention is to provide an improved solid drug formulation containing ospemifene, where the dissolution of the drug is essentially increased. Thus, the invention concerns a solid drug formulation comprising granulates containing a therapeutically active compound of the formula (I) or a geometric isomer, a stereoisomer, a pharmaceutically acceptable salt, an ester thereof or a metabolite thereof, in combination with one or more intra-granular excipients. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 shows dissolution versus time for ospemifene from tablets made by direct compression of the ingredients (diamonds) and from tablets made from granulates comprising the drug (squares). DETAILED DESCRIPTION OF THE INVENTION Granulation: Granulation is a process where primary powder particles are made to adhere to form larger, multiparticle entities called granules. Pharmaceutical granules typically have a size range between 0.2 and 4.0 mm, depending on their subsequent use. In the majority of cases this will be in the production of tablets or capsules when granules will be made as an intermediate product and will have a typical size range between 0.2 and 0.5 mm. The main reasons for granulation are: Prevention of segregation of the constituents of the powder mix. Segregation or demixing is primarily due to differences in the size or density of the components of the mix, the smaller and/or denser particles concentrating at the base or a container with the larger and/or less dense ones above them. An ideal granulation will contain all the constituents of the mix in the correct proportion in each granule and segregation of the ingredients will not occur. Improving the flow properties of the mix. Many powders, because of their small particle size, irregular shape or surface characteristics, are cohesive and do not flow well. Poor flow will often result in a wide weight variation within the final product owing to variable fill of tablet dies etc. Improving the compaction characteristics of the mix. Some powders are difficult to compact even it a readily compactable adhesive is included in the mix, but granules of the same formulation are often more easily compacted and produce stronger tablets. Also other reasons can be mentioned: reduction of dust when handling powders, avoid adhering of slightly hygroscopic materials when stored. The granulation methods can be divided in two types: wet granulation and dry granulation. In a suitable formulation a number of different excipients will be needed in addition to the drug. The common types are diluents, to produce a unit dose weight of a suitable size, and disintegrating agents, which are added to aid the break-up of the granule when it reaches a liquid medium, e.g. on ingestion by the patient. Adhesives in the form of a dry powder may also be added, particularly if dry granulation is employed. These ingredients will be mixed before granulation. Excipients in the granulates are also called intra-granular excipients. When the granulates are formulated to the final formulations, excipients will be added. Excipients outside the granulates are called extra-granular excipients. In the dry granulation methods the primary powder particles are aggregated under high pressure. There are two main processes: either a large tablet (slug) is produced in a heavy-duty tabulating press, or the powder is squeezed between two rollers to produce a sheet of material (roller compaction).These intermediate products are broken by a suitable milling technique. The dry granulation is used for drugs which are sensitive to moisture. The wet granulation involves the massing of a mix of dry primary powder particles using a granulating fluid. The fluid contains a solvent which must be non-toxic and volatile so that it can be removed by drying. Typical liquids include water, ethanol, and isopropanol, either alone or in combination. The granulation liquid may be used alone or, more usually, as a solvent containing a dissolved adhesive (binding agent) which is used to ensure particle adhesion once the granule is dry. The wet mass is forced through a sieve to produce wet granules which are then dried. A subsequent screening stage breaks agglomerates and removes the fine material. Dissolution testing: In vitro dissolution testing serves as an important tool for characterizing the biopharmaceutical quality of a product at different stages in its lifecycle. In early drug development in vitro dissolution properties are supportive for choosing between different alternative formulation candidates for further development and for evaluation of active ingredients/drug substances. Moreover, in vitro dissolution data will be of great importance when assessing changes in production site, manufacturing process or formulation and assist in decision concerning the need for bioavailability studies. Drug absorption from a solid dosage form after oral administration depends on the release of the drug substance from the drug product, the dissolution or solubilization of the drug under physiological conditions, and the permeability across the gastrointestinal tract. Because of the critical nature of the first two of these steps, in vitro dissolution may be relevant to the prediction of in vivo performance. Based on this general consideration, in vitro dissolution tests for immediate release solid oral dosage forms, such as tablets and capsules, are used to a) assess the lot-to-lot quality of a drug product; b) guide development of new formulations; and c) ensure continuing product quality and performance after certain changes, such as changes in the formulation, manufacturing process, site of manufacture, and the scale-up of a manufacturing process. Dissolution profile comparisons: Dissolution profiles may be considered similar by virtue of 1) overall profile similarity and 2) similarity at every dissolution sample time point. The dissolution profile comparisons may be carried out using model independent or model dependent methods. The similarity factor f2 is a logarithmic reciprocal square root transformation of the sum of squared error and is a measurement of the similarity in the percent (%) dissolution between two curves. The similarity factor is calculated according to the following formula f 2 = 50 · log ( 100 ÷ 1 + ( 1 / n ) · ( ∑ t = 1 n ( R t - T t ) ( R t - T t ) ) ) where n is the number of sampling timepoints; Rt is the amount drug released from a reference batch at time t and Tt is the amount drug released from a test batch at time t. For curves to be considered similar, f2 should be close to 100. Generally, f2 values greater than 50 ensure sameness or equivalence of the two curves, i.e. sameness of the performance of the reference product and test product. In the drug formulation according to this invention, the intra-granular excipient can be composed of one or more ingredients, which may belong to the same or different categories of excipients. At least one intra-granular excipient is a disintegrant or a mixture of several disintegrants; a diluent or a mixture of several diluents; or a binder or a mixture of several binders. The intra-granular excipient may also be a combination of at least one diluent and at least one binder; a combination at least one diluent and at least one disintegrant; a combination of at least one disintegrant and at least one binder; or a combination of at least one diluent, at least one disintegrant and at least one binder. As typical non-limiting examples of suitable disintegrants can be mentioned povidone, crospovidone, carboxymethylcellulose, methylcellulose, alginic acid, croscarmellose sodium, sodium starch glycolate, starch, formaldehyde-casein or their combinations. As typical non-limiting examples of suitable diluents can be mentioned maltose, maltodextrin, lactose, fructose, dextrin, microcrystalline cellulose, pregelatinized starch, sorbitol, sucrose, silicified microcrystalline cellulose, powdered cellulose, dextrates, mannitol, calsium phospate or combinations thereof. As typical non-limiting examples of suitable binders can be mentioned acacia, dextrin, starch, povidone, carboxymethylcellulose, guar gum, glucose, hydroxypropyl methylcellulose, methylcellulose, polymethacrylates, maltodextrin, hydroxyethyl cellulose or combinations thereof. The granulates can be made either by dry granulation or by wet granulation according to known technology. Suitable solvents in wet granulation are e.g. water or ethanol. The final solid drug formulation can be any suitable solid formulation such as tablets, capsules, granulates as such or granulates packaged into suitable dosage units, caplets, lozenges, and the like. The term “tablet” shall be understood to cover any kind of tablets, such as uncoated tablets, coated tablets, film-coated tablets, effervescent tablets, oral lyophilisates, orodispersable tablets, gastro-resistant tablets, prolonged-release tablets, modified-release tablets, chewable tablet, oral gums and pillules. The granulates shall be understood to cover also effervescent, gastro-resistant, prolonged-release and modified-release granulates. The capsule shall also be understood to cover gastro-resistant, prolonged-release and modified-release capsules. The formulation may for example be a capsule comprising the granulates encapsulated in a shell made of gelatine or the like. The formulation can in addition to the granulates comprise an extra-granular lubricant. A typical lubricant is, for example, calcium stearate, magnesium stearate, stearic acid, talc, a vegetable oil, poloxamer, a mineral oil, sodium lauryl sulphate, sodium stearyl fumarate, zinc stearate or combinations thereof The formulation can also contain other extra-granular excipients, for example diluents. The drug formulation may alternatively be a tablet comprising the granulates in combination with one or more extra-granular excipient. The extra-granular excipient can be one or more disintegrants, one or more diluents, one or more binders, one or more lubricants, or their combinations. The extra-granular disintegrant can be one of the disintegrants mentioned above or combinations thereof. Similarly, the extra-granular diluents, binders, and lubricants can be selected from those mentioned before. The tablet can also comprise other extra-granular ingredients such as flavouring agents, colouring agents, preservatives, suspending aids and fillers. The granulates comprise preferably one or more disintegrants in the range 0.1 to 10, preferably 0.1 to 4 weight-% of the granulates and one or more diluents in the range 20 to 80 weight-% of the granulates. If the granulates are processed into tablets, such tablets may contain, e.g. extra-granular disintegrants in the range 0.1 to 25%, lubricants 0.1 to 2%, drug containing granulates in the range 20 to 80%, and the remaining part diluents optionally in combination with other other ingredients such as binders, flavouring agents, colouring agents, preservatives, suspending aids, fillers and the like. The percentages are all weight-% of the tablet. The improved drug formulation according to this invention is particularly useful when treating women during or after the menopause. However, the method according to this invention is not restricted to women in this age group. The term “metabolite” shall be understood to cover any ospemifene or (deaminohydroxy)toremifene metabolite already discovered or to be discovered. As examples of such metabolites can be mentioned the oxidation metabolites mentioned in Kangas (1990) on page 9 (TORE VI, TORE VII, TORE XVIII, TORE VIII, TORE XIII), especially TORE VI and TORE XVIII, and other metabolites of the compound. The most important metabolite of ospemifene 4-hydroxyospemifene, which has the formula The use of mixtures of isomers of compound (I) shall also be included in this invention. The compound (I) is preferably ospemifene. The particle size of the ospemifene in the granulates is important in order to get a good dissolution. Preferably at least 90% of the drug substance shall have a particle size less than 250 micrometer. More preferably, 90% of the drug substance shall have a particle size less than 150 micrometer, and 50% of the drug substance shall have a particle size less than 25 micrometer. Especially preferably, 90% of the drug substance shall have a particle size less than 50 micrometer, and 50% of the drug substance shall have a particle size less than 15 micrometer. The term “particle size” refers to the particle diameter, or in case the particles are not spherical, to the largest extension in one direction of the particle. The improved drug formulation according to this invention is useful in any application of ospemifene, especially when the compound is used for treatment or prevention of osteoporosis or for treatment or prevention of symptoms related to skin atrophy, or to epithelial or mucosal atrophy. A particular form of atrophy which can be inhibited by administering of ospemifene is urogenital atrophy. Symptoms related to urogenital atrophy can be divided in two subgroups: urinary symptoms and vaginal symptoms. As examples of urinary symptoms can be mentioned micturation disorders, dysuria, hematuria, urinary frequency, sensation of urgency, urinary tract infections, urinary tract inflammation, nocturia, urinary incontinence, urge incontinence and involuntary urinary leakage. As examples of vaginal symptoms can be mentioned irritation, itching, burning, maladorous discharge, infection, leukorrhea, vulvar pruritus, feeling of pressure and postcoital bleeding. According to previous data, the optimal clinical dose of ospemifene is expected to be higher than 25 mg daily and lower than 100 mg daily. A particularly preferable daily dose has been suggested in the range 30 to 90 mg. At the higher doses (100 and 200 mg daily), ospemifene shows properties more similar to those of tamoxifen and toremifene. Due to the enhanced bioavailability according to the method of this invention, it can be predicted that the same therapeutical effect can be achieved with doses lower those recommended earlier. The invention will be disclosed more in detail in the following non-restrictive Experimental Section. Experimental Section Two different ospemifene tablets were made. One of them was made of ospemifine granulates, which were made by the wet method, and the other tablet was made by direct compression of the ingredients. The composition of the two tablets is given below. Quantity (%) Names of the Quantity (%) DIRECT ingredients GRANULATION COMPRESSION Function Ospemifene 30 30 Active Pregelatinized starch 38 38 Diluent Maize starch 25 25 Diluent Povidone 2 2 Binder Sodium starch 4 4 Disintegrant glycolate Magnesium stearate 1 1 Lubricant Water, purified* 25 — Solvent *Evaporates during the manufacturing process The tablets were subjected to dissolution testing according to the USP 24 paddle method using manual sampling. One tablet was paced in each of twelve vessels containing 900 ml of 2% sodium dodecyl sulphate. The pH was 9.8. After 5, 15, 30, 60, 120, 180, 120 and 240 minutes, 10 ml was manually withdrawn from the dissolution vessels. The samples were filtered immediately and spectrophotometrically analysed using a 2-mm flow-through cell in a computerized spectrophotometer. The concentration of ospemifene in the sample solution was determined by comparison of the absorbance at 238 nm with that of a standard solution. The results are shown in FIG. 1. The calculated similarity factor f2 was 36, which means that the dissolution profiles for the two tablets are very different. FIG. 1 shows that the tablet containing granulates significantly improves the dissolution of ospemifene, compared to tablets manufactured by direct compression. It will be appreciated that the methods of the present invention can be incorporated in the form of a variety of embodiments, only a few of which are disclosed herein. It will be apparent for the expert skilled in the field that other embodiments exist and do not depart from the spirit of the invention. Thus, the described embodiments are illustrative and should not be construed as restrictive. REFERENCES Kangas L. Biochemical and pharmacological effects of toremifene metabolites. Cancer Chemother Pharmacol 27:8-12, 1990. Kauffinan R F, Bryant H U. Selective estrogen receptor modulators. Drug News Perspect 8: 531-539, 1995. | <SOH> BACKGROUND OF THE INVENTION <EOH>The publications and other materials used herein to illuminate the background of the invention, and in particular, cases to provide additional details respecting the practice, are incorporated by reference. “SERM”s (selective estrogen receptor modulators) have both estrogen-like and antiestrogenic properties (Kauffman & Bryant, 1995). The effects may be tissue-specific as in the case of tamoxifen and toremifene which have estrogen-like effects in the bone, partial estrogen-like effect in the uterus and liver, and pure antiestrogenic effect in breast cancer. Raloxifene and droloxifen are similar to tamoxifen and toremifene, except that their antiestrogenic properties dominate. Based on the published information, many SERMs are more likely to cause menopausal symptoms than to prevent them. They have, however, other important benefits in elderly women: they decrease total and LDL cholesterol, thus deminishing the risk of cardiovascular diseases, and they may prevent osteoporosis and inhibit breast cancer growth in postmenopausal women. There are also almost pure antiestrogens under development. Ospemifene is the Z-isomer of the compound of formula (I) and it is one of the main metabolites of toremifene, is known to be an estrogen agonist and antagonist (Kangas, 1990; International patent publications WO 96/07402 and WO 97/32574). The compound is also called (deaminohydroxy)toremifene and it is also known under the code FC-1271a. Ospemifene has relatively weak estrogenic and antiestrogenic effects in the classical hormonal tests (Kangas, 1990). It has anti-osteoporosis actions and it decreases total and LDL cholesterol levels in both experimental models and in human volunteers (International patent publications WO 96/07402 and WO 97/32574). It also has antitumor activity in an early stage of breast cancer development in an animal breast cancer model. Ospemifene is also the first SERM which has been shown to have beneficial effects in climacteric syndromes in healthy women. The use of ospemifene for the treatment of certain climacteric disorders in postmenopausal women, namely vaginal dryness and sexual dysfunction, is disclosed in WO 02/07718. The published patent application WO 03/103649 describes the use of ospemifene for inhibition of atrophy and for the treatment or prevention of atrophy-related diseases or disorders in women, especially in women during or after the menopause. | <SOH> OBJECT AND SUMMARY OF THE INVENTION <EOH>An object of the present invention is to provide an improved solid drug formulation containing ospemifene, where the dissolution of the drug is essentially increased. Thus, the invention concerns a solid drug formulation comprising granulates containing a therapeutically active compound of the formula (I) or a geometric isomer, a stereoisomer, a pharmaceutically acceptable salt, an ester thereof or a metabolite thereof, in combination with one or more intra-granular excipients. | 20040223 | 20140204 | 20050825 | 66231.0 | 1 | AHMED, HASAN SYED | SOLID FORMULATIONS OF OSPEMIFENE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,783,083 | ACCEPTED | Grant, acknowledgement, and rate control active sets | Embodiments disclosed herein address the need in the art for efficient management of grant, acknowledgement, and rate control channels. In one aspect, a list associated with a first station is generated or stored, the list comprising zero or more identifiers, each identifier identifying one of a plurality of second stations for sending a message to the first station. In another aspect, sets of lists for one or more first stations are generated or stored. In yet another aspect, the messages may be acknowledgements, rate control commands, or grants. In yet another aspect, messages comprising one or more identifiers in the list are generated. Various other aspects are also presented. These aspects have the benefit of reduced overhead while managing grant, acknowledgment and rate control messaging for one or more remote stations. | 1. An apparatus, comprising: a memory for storing a list comprising zero or more identifiers, the list associated with a first station, each identifier identifying one of a plurality of second stations for sending a message to the first station. 2. The apparatus of claim 1, wherein the message is an acknowledgement. 3. The apparatus of claim 1, wherein the message is a rate control command. 4. The apparatus of claim 1, wherein the message is a grant. 5. The apparatus of claim 1, wherein the apparatus is included in the first station. 6. The apparatus of claim 1, wherein the apparatus is included in a station controller. 7. The apparatus of claim 1, wherein the memory stores a plurality of lists, the plurality of lists associated with the first station, each list comprising zero or more identifiers, each identifier identifying one of a plurality of second stations for sending a message to the first station. 8. The apparatus of claim 7, wherein the message for one of the lists in the plurality of lists is an acknowledgement. 9. The apparatus of claim 7, wherein the message for one of the lists in the plurality of lists is a rate control command. 10. The apparatus of claim 7, wherein the message for one of the lists in the plurality of lists is a grant. 11. An apparatus, comprising: a memory for storing a list comprising zero or more identifiers, each identifier identifying one of a plurality of remote stations authorized for sending a first message; and a receiver for receiving a plurality of signals from the plurality of remote stations identified in the list. 12. The apparatus of claim 11, wherein the plurality of received signals comprise one or more first messages. 13. The apparatus of claim 12, wherein the first message is an acknowledgement. 14. The apparatus of claim 12, wherein the first message is a rate control command. 15. The apparatus of claim 12, wherein the first message is a grant. 16. The apparatus of claim 12, further comprising a transmitter for transmitting in response to a received signal. 17. The apparatus of claim 16, wherein the transmitter transmits in response to a received acknowledgement. 18. The apparatus of claim 16, wherein the transmitter transmits at a rate adjusted in response to a received rate control command. 19. The apparatus of claim 16, wherein the transmitter transmits at a rate in accordance with a received grant. 20. An apparatus, comprising: a processor for generating a list comprising zero or more identifiers, the list associated with a first station, each identifier identifying one of a plurality of second stations for sending a first message to the first station. 21. The apparatus of claim 20, wherein the list is generated in accordance with one or more predetermined criteria. 22. The apparatus of claim 20, further comprising a receiver for receiving a measurement of a second station, wherein the processor includes an identifier associated with the second station in the list in accordance with the received measurement and in accordance with one or more predetermined criteria. 23. The apparatus of claim 20, further comprising a transmitter for transmitting a second message to the first station, wherein the processor further generates the second message comprising zero or more of the identifiers from the list. 24. The apparatus of claim 23, wherein the second message identifies a list of identifiers for storing in the first station. 25. The apparatus of claim 23, wherein the second message directs the first station to add an identifier to a list of identifiers stored in the first station. 26. The apparatus of claim 23, wherein the second message directs the first station to remove an identifier from a list of identifiers stored in the first station. 27. The apparatus of claim 20, further comprising a transmitter for transmitting a third message to a second station identified in the list, the third message authorizing the second station to transmit the first message to the first station. 28. A station controller, comprising: a memory for storing a plurality of lists, each list associated with one of a plurality of first stations, each list comprising zero or more identifiers, each identifier identifying one of a plurality of second stations for sending a message to the respective first station. 29. The station controller of claim 28, wherein the message is an acknowledgement. 30. The station controller of claim 28, wherein the message is a rate control command. 31. The station controller of claim 28, wherein the message is a grant. 32. The station controller of claim 28, wherein the memory stores a plurality of sets of lists, each set of lists associated with one of the plurality of first stations, each set comprising one or more lists, each list comprising zero or more identifiers, each identifier identifying one of a plurality of second stations for sending a message to the respective first station. 33. The station controller of claim 32, wherein the message for one of the lists in the set of lists is an acknowledgement. 34. The station controller of claim 32, wherein the message for one of the lists in the set of lists is a rate control command. 35. The station controller of claim 32, wherein the message for one of the lists in the set of lists is a grant. 36. A communication system, comprising: a memory for storing a plurality of lists, each list associated with one of a plurality of first stations, each list comprising zero or more identifiers, each identifier identifying one of a plurality of second stations for sending a message to the respective first station. 37. A method for monitoring messages, comprising: storing a list comprising zero or more identifiers, the list associated with a first station, each identifier identifying one of a plurality of second stations for sending a message to the first station. 38. The method of claim 37, further comprising sending one or more messages to the first station from one or more second stations identified in the list. 39. The method of claim 38, wherein one of the messages is an acknowledgement. 40. The method of claim 38, wherein one of the messages is a rate control command. 41. The method of claim 38, wherein one of the messages is a grant. 42. The method of claim 37, further comprising monitoring channels from the second stations identified in the list. 43. The method of claim 37, further comprising transmitting in response to an acknowledgement. 44. The method of claim 37, further comprising adjusting a transmission rate in response to a rate control command. 45. The method of claim 37, further comprising transmitting at a rate in accordance with a grant. 46. A method for monitoring messages, comprising: generating a list comprising zero or more identifiers, the list associated with a first station, each identifier identifying one of a plurality of second stations for sending a first message to the first station. 47. The method of claim 46, further comprising transmitting a second message to the first station, the second message comprising zero or more of the identifiers from the list. 48. The method of claim 47, further comprising storing the list of identifiers from the second message in the first station. 49. The method of claim 47, wherein the second message directs the first station to add an identifier to a list of identifiers stored in the first station. 50. The method of claim 47, wherein the second message directs the first station to remove an identifier from a list of identifiers stored in the first station. 51. The method of claim 46, further comprising transmitting a third message to a second station identified in the list, the third message authorizing the second station to transmit the first message to the first station. 52. An apparatus, comprising: means for storing a list comprising zero or more identifiers, the list associated with a first station, each identifier identifying one of a plurality of second stations for sending a message to the first station. 53. The apparatus of claim 52, further comprising means for sending one or more messages to the first station from one or more second stations identified in the list. 54. An apparatus, comprising: means for generating a list comprising zero or more identifiers, the list associated with a first station, each identifier identifying one of a plurality of second stations for sending a first message to the first station. 55. The apparatus of claim 54, further comprising means for transmitting a second message to the first station, the second message comprising zero or more of the identifiers from the list. 56. The apparatus of claim 54, further comprising means for transmitting a third message to a second station identified in the list, the third message authorizing the second station to transmit the first message to the first station. 57. A communication system, comprising: means for storing a list comprising zero or more identifiers, the list associated with a first station, each identifier identifying one of a plurality of second stations for sending a message to the first station. 58. The communication system of claim 57, further comprising means for sending one or more messages to the first station from one or more second stations identified in the list. 59. The communication system of claim 57, further comprising means for transmitting a second message to the first station, the second message comprising zero or more of the identifiers from the list. 60. The communication system of claim 57, further comprising means for transmitting a third message to a second station identified in the list, the third message authorizing the second station to transmit the first message to the first station. 61. Computer readable media operable to perform the following steps: storing a list comprising zero or more identifiers, the list associated with a first station, each identifier identifying one of a plurality of second stations for sending a message to the first station. 62. The media of claim 61, further operable to perform sending one or more messages to the first station from one or more second stations identified in the list. 63. Computer readable media operable to perform the following steps: generating a list comprising zero or more identifiers, the list associated with a first station, each identifier identifying one of a plurality of second stations for sending a first message to the first station. 64. The media of claim 63, further operable to perform transmitting a second message to the first station, the second message comprising zero or more of the identifiers from the list. 65. The media of claim 63, further operable to perform transmitting a third message to a second station identified in the list, the third message authorizing the second station to transmit the first message to the first station. | CLAIM OF PRIORITY UNDER 35 U.S.C. §119 The present Application for Patent claims priority to Provisional Application No. 60/493,046 entitled “Reverse Link Rate Control for CDMA 2000 Rev D” filed Aug. 5, 2003, and Provisional Application No. 60/496,297, entitled “Reverse Link Rate Control for CDMA 2000. Rev D”, filed Aug. 18, 2003. BACKGROUND 1. Field The present invention relates generally to wireless communications, and more specifically to active sets for grant, acknowledgement, and rate control channels. 2. Background Wireless communication systems are widely deployed to provide various types of communication such as voice and data. A typical wireless data system, or network, provides multiple users access to one or more shared resources. A system may use a variety of multiple access techniques such as Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), Code Division Multiplexing (CDM), and others. Example wireless networks include cellular-based data systems. The following are several such examples: (1) the “TIA/EIA-95-B Mobile Station-Base Station Compatibility Standard for Dual-Mode Wideband Spread Spectrum Cellular System” (the IS-95 standard), (2) the standard offered by a consortium named “3rd Generation Partnership Project” (3GPP) and embodied in a set of documents including Document Nos. 3G TS 25.211, 3G TS 25.212, 3G TS 25.213, and 3G TS 25.214 (the W-CDMA standard), (3) the standard offered by a consortium named “3rd Generation Partnership Project 2” (3GPP2) and embodied in “TR-45.5 Physical Layer Standard for cdma2000 Spread Spectrum Systems” (the IS-2000 standard), (4) the high data rate (HDR) system that conforms to the TIA/EIA/IS-856 standard (the IS-856 standard), and (5) Revision C of the IS-2000 standard, including C.S0001.C through C.S0006.C, and related documents (including subsequent Revision D submissions) are referred to as the 1xEV-DV proposal. In an example system, Revision D of the IS-2000 standard (currently under development), the transmission of mobile stations on the reverse link is controlled by base stations. A base station may decide the maximum rate or Traffic-to-Pilot Ratio (TPR) at which a mobile station is allowed to transmit. Currently proposed are two types of control mechanisms: grant based and rate-control based. In grant-based control, a mobile station feeds back to a base station information on the mobile station's transmit capability, data buffer size, and Quality of Service (QoS) level, etc. The base station monitors feedback from a plurality of mobile stations and decides which are allowed to transmit and the corresponding maximum rate allowed for each. These decisions are delivered to the mobile stations via grant messages. In rate-control based control, a base station adjusts a mobile station's rate with limited range (i.e. one rate up, no change, or one rate down). The adjustment command is conveyed to the mobile stations using a simple binary rate control bit or multiple-valued indicator. Under full buffer conditions, where active mobile stations have large amounts of data, grant based techniques and rate control techniques perform roughly the same. Ignoring overhead issues, the grant method may be better able to control the mobile station in situations with real traffic models. Ignoring overhead issues, the grant method may be better able to control different QoS streams. Two types of rate control may be distinguished, including a dedicated rate control approach, giving every mobile station a single bit, and common rate control, using a single bit per sector. Various hybrids of these two may assign multiple mobile stations to a rate control bit. A common rate control approach may require less overhead. However, it may offer less control over mobile stations when contrasted with a more dedicated control scheme. As the number of mobiles transmitting at any one time decreases, then the common rate control method and the dedicated rate control approach each other. Grant based techniques can rapidly change the transmission rate of a mobile station. However, a pure grant based technique may suffer from high overhead if there are continual rate changes. Similarly, a pure rate control technique may suffer from slow ramp-up times and equal or higher overheads during the ramp-up times. Neither approach provides both reduced overhead and large or rapid rate adjustments. An example of an approach to meet this need is disclosed in U.S. patent application Ser. No. ______ (ATTORNEY DOCKET NO. 030525), entitled “COMBINING GRANT, ACKNOWLEDGEMENT, AND RATE CONTROL COMMANDS”, filed Feb. 17, 2004, assigned to the assignee of the present invention. In addition, it may be desirable to reduce the number of control channels, while maintaining desirable probability of error for the associated commands on the control channels. There is a need in the art for a system that provides the ability to control the rates of (or the allocation of resources to) both individual mobile stations as well as groups of mobile stations, without unduly increasing channel count. Furthermore, there is a need to be able to tailor the probability of error of various rate control or acknowledgement commands. An example of an approach to meet this need is disclosed in U.S. patent application Ser. No. ______ (Attorney Docket No. 030560), entitled “EXTENDED ACKNOWLEDGEMENT AND RATE CONTROL CHANNEL”, filed Feb. 17, 2004, assigned to the assignee of the present invention. While the flexibility of control afforded with combined grant, rate controlled, and acknowledged transmission allows for tailoring of the allocation of system resources, it may be desirable to control the role of various base stations in a system with respect to which signals they transmit and in which allocation controls they may participate. An ad-hoc signaling scheme to provide control may be costly in terms of the overhead required for signaling. Failing to control the reach of some base stations may also cause system performance issues if a grant or rate control command is issued, with effects that are not apparent to the issuing base station. There is therefore a need in the art for efficient management of grant, acknowledgement, and rate control channels. SUMMARY Embodiments disclosed herein address the need in the art for efficient management of grant, acknowledgement, and rate control channels. In one aspect, a list associated with a first station is generated or stored, the list comprising zero or more identifiers, each identifier identifying one of a plurality of second stations for sending a message to the first station. In another aspect, sets of lists for one or more first stations are generated or stored. In yet another aspect, the messages may be acknowledgements, rate control commands, or grants. In yet another aspect, messages comprising one or more identifiers in the list are generated. Various other aspects are also presented. These aspects have the benefit of reduced overhead while managing grant, acknowledgment and rate control messaging for one or more remote stations. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a general block diagram of a wireless communication system capable of supporting a number of users; FIG. 2 depicts an example mobile station and base station configured in a system adapted for data communication; FIG. 3 is a block diagram of a wireless communication device, such as a mobile station or base station; FIG. 4 depicts an exemplary embodiment of data and control signals for reverse link data communication; FIG. 5 is an exemplary acknowledgement channel; FIG. 6 is an exemplary rate control channel; FIG. 7 is an example method deployable in a base station to allocate capacity in response to requests and transmissions from one or more mobile stations; FIG. 8 is an example method of generating grants, acknowledgements, and rate control commands; FIG. 9 is an example method for a mobile station to monitor and respond to grants, acknowledgements, and rate control commands; FIG. 10 depicts timing for an example embodiment with combined acknowledgement and rate control channels; FIG. 11 depicts timing for an example embodiment with combined acknowledgement and rate control channels, along with a new grant; FIG. 12 depicts timing for an example embodiment with combined acknowledgement and rate control channels, without a grant; FIG. 13 depicts an example embodiment of a system comprising a dedicated rate control signal and a common rate control signal; FIG. 14 depicts an embodiment of a system comprising a forward extended acknowledgment channel; FIG. 15 depicts an example constellation suitable for deployment on an extended acknowledgment channel; FIG. 16 depicts an alternate constellation suitable for deployment on an extended acknowledgment channel; FIG. 17 depicts a three-dimensional example constellation suitable for deployment on an extended acknowledgment channel; FIG. 18 depicts an embodiment of a method for processing received transmissions, including acknowledgement and rate control; FIG. 19 depicts an embodiment of a method for responding to common and dedicated rate control; FIG. 20 depicts an alternate embodiment of a method for processing received transmissions, including acknowledgement and rate control; FIG. 21 depicts a method for receiving and responding to a forward extended acknowledgment channel; FIG. 22 is a general block diagram of a wireless communication system including extended active sets; FIG. 23 is an example extended active set; FIG. 24-26 are examples of alternate example extended active sets; FIG. 27 depicts an example embodiment of a method for generation of an extended active set; FIG. 28 depicts an example embodiment of a method for transmission in accordance with an extended active set; FIG. 29 depicts an example embodiment of a method for communicating with an extended active set in a mobile station; and FIG. 30 depicts example messages suitable for communicating changes to an extended active set. DETAILED DESCRIPTION Example embodiments, detailed below, provide for allocation of a shared resource, such as that shared by one or more mobile stations in a communication system, by advantageously controlling or adjusting one or more data rates in connection with various acknowledgment messages communicated in the system. Techniques for combining the use of grant channels, acknowledgement channels, and rate control channels to provide for a combination of grant based scheduling and rate controlled scheduling, and the benefits thereof, are disclosed herein. Various embodiments may allow for one or more of the following benefits: increasing the transmission rate of a mobile station quickly, quickly stopping a mobile station from transmitting, low-overhead adjustments of a mobile station's rate, low-overhead mobile station transmission acknowledgement, low overhead overall, and Quality of Service (QoS) control for streams from one or mobile stations. Combining a rate control channel with an acknowledgment channel, using a constellation of points for the various command pairs, allows for a reduction in control channels. In addition, the constellation may be formed to provide the desired probability of error for each of the associated commands. A dedicated rate control signal may be deployed alongside a common rate control signal. Deploying one or more dedicated rate control channels with one or more common rate control channels allows for specific rate control of a single mobile station as well as the ability to control larger groups of mobile stations with reduced overhead. Various other benefits will be detailed below. One or more exemplary embodiments described herein are set forth in the context of a digital wireless data communication system. While use within this context is advantageous, different embodiments of the invention may be incorporated in different environments or configurations. In general, the various systems described herein may be formed using software-controlled processors, integrated circuits, or discrete logic. The data, instructions, commands, information, signals, symbols, and chips that may be referenced throughout the application are advantageously represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or a combination thereof. In addition, the blocks shown in each block diagram may represent hardware or method steps. More specifically, various embodiments of the invention may be incorporated in a wireless communication system operating in accordance with a communication standard outlined and disclosed in various standards published by the Telecommunication Industry Association (TIA) and other standards organizations. Such standards include the TIA/EIA-95 standard, TIA/EIA-IS-2000 standard, IMT-2000 standard, UMTS and WCDMA standard, GSM standard, all incorporated by reference herein. A copy of the standards may be obtained by writing to TIA, Standards and Technology Department, 2500 Wilson Boulevard, Arlington, Va. 22201, United States of America. The standard generally identified as UMTS standard, incorporated by reference herein, may be obtained by contacting 3GPP Support Office, 650 Route des Lucioles-Sophia Antipolis, Valbonne-France. FIG. 1 is a diagram of a wireless communication system 100 that may be designed to support one or more CDMA standards and/or designs (e.g., the W-CDMA standard, the IS-95 standard, the cdma2000 standard, the HDR specification, the 1xEV-DV system). In an alternative embodiment, system 100 may additionally support any wireless standard or design other than a CDMA system. In the exemplary embodiment, system 100 is a 1xEV-DV system. For simplicity, system 100 is shown to include three base stations 104 in communication with two mobile stations 106. The base station and its coverage area are often collectively referred to as a “cell”. In IS-95, cdma2000, or 1xEV-DV systems, for example, a cell may include one or more sectors. In the W-CDMA specification, each sector of a base station and the sector's coverage area is referred to as a cell. As used herein, the term base station can be used interchangeably with the terms access point or Node B. The term mobile station can be used interchangeably with the terms user equipment (UE), subscriber unit, subscriber station, access terminal, remote terminal, or other corresponding terms known in the art. The term mobile station encompasses fixed wireless applications. Depending on the CDMA system being implemented, each mobile station 106 may communicate with one (or possibly more) base stations 104 on the forward link at any given moment, and may communicate with one or more base stations on the reverse link depending on whether or not the mobile station is in soft handoff. The forward link (i.e., downlink) refers to transmission from the base station to the mobile station, and the reverse link (i.e., uplink) refers to transmission from the mobile station to the base station. While the various embodiments described herein are directed to providing reverse-link or forward-link signals for supporting reverse link transmission, and some may be well suited to the nature of reverse link transmission, those skilled in the art will understand that mobile stations as well as base stations can be equipped to transmit data as described herein and the aspects of the present invention apply in those situations as well. The word “exemplary” is used exclusively herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. 1xEV-DV Forward Link Data Transmission A system 100, such as the one described in the 1xEV-DV proposal, generally comprises forward link channels of four classes: overhead channels, dynamically varying IS-95 and IS-2000 channels, a Forward Packet Data Channel (F-PDCH), and some spare channels. The overhead channel assignments vary slowly; for example, they may not change for months. They are typically changed when there are major network configuration changes. The dynamically varying IS-95 and IS-2000 channels are allocated on a per call basis or are used for IS-95, or IS-2000 Release 0 through B voice and packet services. Typically, the available base station power remaining after the overhead channels and dynamically varying channels have been assigned is allocated to the F-PDCH for remaining data services The F-PDCH, similar to the traffic channel in the IS-856 standard, is used to send data at the highest supportable data rate to one or two users in each cell at a time. In IS-856, the entire power of the base station and the entire space of Walsh functions are available when transmitting data to a mobile station. However, in a 1xEV-DV system, some base station power and some of the Walsh functions are allocated to overhead channels and existing IS-95 and cdma2000 services. The data rate that is supportable depends primarily upon the available power and Walsh codes after the power and Walsh codes for the overhead, IS-95, and IS-2000 channels have been assigned. The data transmitted on the F-PDCH is spread using one or more Walsh codes. In a 1xEV-DV system, the base station generally transmits to one mobile station on the F-PDCH at a time, although many users may be using packet services in a cell. (It is also possible to transmit to two users by scheduling transmissions for the two users, and allocating power and Walsh channels to each user appropriately.) Mobile stations are selected for forward link transmission based upon some scheduling algorithm. In a system similar to IS-856 or 1xEV-DV, scheduling is based in part on channel quality feedback from the mobile stations being serviced. For example, in IS-856, mobile stations estimate the quality of the forward link and compute a transmission rate expected to be sustainable for the current conditions. The desired rate from each mobile station is transmitted to the base station. The scheduling algorithm may, for example, select a mobile station for transmission that supports a relatively higher transmission rate in order to make more efficient use of the shared communication channel. As another example, in a 1xEV-DV system, each mobile station transmits a Carrier-to-Interference (C/I) estimate as the channel quality estimate on the Reverse Channel Quality Indicator Channel (R-CQICH). The scheduling algorithm is used to determine the mobile station selected for transmission, as well as the appropriate rate and transmission format in accordance with the channel quality. As described above, a wireless communication system 100 may support multiple users sharing the communication resource simultaneously, such as an IS-95 system, may allocate the entire communication resource to one user at time, such as an IS-856 system, or may apportion the communication resource to allow both types of access. A 1xEV-DV system is an example of a system that divides the communication resource between both types of access, and dynamically allocates the apportionment according to user demand. An exemplary forward-link embodiment has just been described. Various exemplary reverse-link embodiments are detailed further below. FIG. 2 depicts an example mobile station 106 and base station 104 configured in a system 100 adapted for data communication. Base station 104 and mobile station 106 are shown communicating on a forward and a reverse link. Mobile station 106 receives forward link signals in receiving subsystem 220. A base station 104 communicating the forward data and control channels, detailed below, may be referred to herein as the serving station for the mobile station 106. An example receiving subsystem is detailed further below with respect to FIG. 3. A Carrier-to-Interference (C/I) estimate is made for the forward link signal received from the serving base station in the mobile station 106. A C/I measurement is an example of a channel quality metric used as a channel estimate, and alternate channel quality metrics can be deployed in alternate embodiments. The C/I measurement is delivered to transmission subsystem 210 in the base station 104, an example of which is detailed further below with respect to FIG. 3. The transmission subsystem 210 delivers the C/I estimate over the reverse link where it is delivered to the serving base station. Note that, in a soft handoff situation, well known in the art, the reverse link signals transmitted from a mobile station may be received by one or more base stations other than the serving base station, referred to herein as non-serving base stations. Receiving subsystem 230, in base station 104, receives the C/I information from mobile station 106. Scheduler 240, in base station 104, is used to determine whether and how data should be transmitted to one or more mobile stations within the serving cell's coverage area. Any type of scheduling algorithm can be deployed within the scope of the present invention. One example is disclosed in U.S. patent application Ser. No. 08/798,951, entitled “METHOD AND APPARATUS FOR FORWARD LINK RATE SCHEDULING”, filed Feb. 11, 1997, assigned to the assignee of the present invention. In an example 1xEV-DV embodiment, a mobile station is selected for forward link transmission when the C/I measurement received from that mobile station indicates that data can be transmitted at a certain rate. It is advantageous, in terms of system capacity, to select a target mobile station such that the shared communication resource is always utilized at its maximum supportable rate. Thus, the typical target mobile station selected may be the one with the greatest reported C/I. Other factors may also be incorporated in a scheduling decision. For example, minimum quality of service guarantees may have been made to various users. It may be that a mobile station, with a relatively lower reported C/I, is selected for transmission to maintain a minimum data transfer rate to that user. It may be that a mobile station, not with the greatest reported C/I, is selected for transmission to maintain certain fairness criterion among all users. In the example 1xEV-DV system, scheduler 240 determines which mobile station to transmit to, and also the data rate, modulation format, and power level for that transmission. In an alternate embodiment, such as an IS-856 system, for example, a supportable rate/modulation format decision can be made at the mobile station, based on channel quality measured at the mobile station, and the transmit format can be transmitted to the serving base station in lieu of the C/I measurement. Those of skill in the art will recognize myriad combinations of supportable rates, modulation formats, power levels, and the like which can be deployed within the scope of the present invention. Furthermore, although in various embodiments described herein the scheduling tasks are performed in the base station, in alternate embodiments, some or all of the scheduling process may take place in the mobile station. Scheduler 240 directs transmission subsystem 250 to transmit to the selected mobile station on the forward link using the selected rate, modulation format, power level, and the like. In the example embodiment, messages on the control channel, or F-PDCCH, are transmitted along with data on the data channel, or F-PDCH. The control channel can be used to identify the recipient mobile station of the data on the F-PDCH, as well as identifying other communication parameters useful during the communication session. A mobile station should receive and demodulate data from the F-PDCH when the F-PDCCH indicates that mobile station is the target of the transmission. The mobile station responds on the reverse link following the receipt of such data with a message indicating the success or failure of the transmission. Retransmission techniques, well known in the art, are commonly deployed in data communication systems. A mobile station may be in communication with more than one base station, a condition known as soft handoff. Soft handoff may include multiple sectors from one base station (or one Base Transceiver Subsystem (BTS)), known as softer handoff, as well as with sectors from multiple BTSs. Base station sectors in soft handoff are generally stored in a mobile station's Active Set. In a simultaneously shared communication resource system, such as IS-95, IS-2000, or the corresponding portion of a 1xEV-DV system, the mobile station may combine forward link signals transmitted from all the sectors in the Active Set. In a data-only system, such as IS-856, or the corresponding portion of a 1xEV-DV system, a mobile station receives a forward link data signal from one base station in the Active Set, the serving base station (determined according to a mobile station selection algorithm, such as those described in the C.S0002.C standard). Other forward link signals, examples of which are detailed further below, may also be received from non-serving base stations. Reverse link signals from the mobile station may be received at multiple base stations, and the quality of the reverse link is generally maintained for the base stations in the active set. It is possible for reverse link signals received at multiple base stations to be combined. In general, soft combining reverse link signals from disparately located base stations would require significant network communication bandwidth with very little delay, and so the example systems listed above do not support it. In softer handoff, reverse link signals received at multiple sectors in a single BTS can be combined without network signaling. While any type of reverse link signal combining may be deployed within the scope of the present invention, in the example systems described above, reverse link power control maintains quality such that reverse link frames are successfully decoded at one BTS (switching diversity). Reverse link data transmission may be carried out in system 100 as well. The receiving and transmission subsystems 210-230, and 250, described may be deployed to send control signals on the forward link to direct data transmission on the reverse link. Mobile stations 106 may transmit control information on the reverse link as well. Various mobile stations 106 communicating with one or more base stations 104 may access the shared communication resource (i.e. the reverse link channel, which may be variably allocated, as in 1xEV-DV, or a fixed allocation, as in IS-856), in response to various access control and rate control techniques, examples of which are detailed below. Scheduler 240 may be deployed to determine the allocation of reverse link resources. Example control and data signals for reverse link data communication are detailed below. Example Base Station and Mobile Station Embodiments FIG. 3 is a block diagram of a wireless communication device, such as mobile station 106 or base station 104. The blocks depicted in this example embodiment will generally be a subset of the components included in either a base station 104 or mobile station 106. Those of skill in the art will readily adapt the embodiment shown in FIG. 3 for use in any number of base station or mobile station configurations. Signals are received at antenna 310 and delivered to receiver 320. Receiver 320 performs processing according to one or more wireless system standards, such as the standards listed above. Receiver 320 performs various processing such as Radio Frequency (RF) to baseband conversion, amplification, analog to digital conversion, filtering, and the like. Various techniques for receiving are known in the art. Receiver 320 may be used to measure channel quality of the forward or reverse link, when the device is a mobile station or base station, respectively, although a separate channel quality estimator 335 is shown for clarity of discussion, detailed below. Signals from receiver 320 are demodulated in demodulator 325 according to one or more communication standards. In an example embodiment, a demodulator capable of demodulating 1xEV-DV signals is deployed. In alternate embodiments, alternate standards may be supported, and embodiments may support multiple communication formats. Demodulator 330 may perform RAKE receiving, equalization, combining, deinterleaving, decoding, and various other functions as required by the format of the received signals. Various demodulation techniques are known in the art. In a base station 104, demodulator 325 will demodulate according to the reverse link. In a mobile station 106, demodulator 325 will demodulate according to the forward link. Both the data and control channels described herein are examples of channels that can be received and demodulated in receiver 320 and demodulator 325. Demodulation of the forward data channel will occur in accordance with signaling on the control channel, as described above. Message decoder 330 receives demodulated data and extracts signals or messages directed to the mobile station 106 or base station 104 on the forward or reverse links, respectively. Message decoder 330 decodes various messages used in setting up, maintaining and tearing down a call (including voice or data sessions) on a system. Messages may include channel quality indications, such as C/I measurements, power control messages, or control channel messages used for demodulating the forward data channel. Various types of control messages may be decoded in either a base station 104 or mobile station 106 as transmitted on the reverse or forward links, respectively. For example, described below are request messages and grant messages for scheduling reverse link data transmission for generation in a mobile station or base station, respectively. Various other message types are known in the art and may be specified in the various communication standards being supported. The messages are delivered to processor 350 for use in subsequent processing. Some or all of the functions of message decoder 330 may be carried out in processor 350, although a discrete block is shown for clarity of discussion. Alternatively, demodulator 325 may decode certain information and send it directly to processor 350 (a single bit message such as an ACK/NAK or a power control up/down command are examples). Various signals and messages for use in embodiments disclosed herein are detailed further below. Channel quality estimator 335 is connected to receiver 320, and used for making various power level estimates for use in procedures described herein, as well as for use in various other processing used in communication, such as demodulation. In a mobile station 106, C/I measurements may be made. In addition, measurements of any signal or channel used in the system may be measured in the channel quality estimator 335 of a given embodiment. In a base station 104 or mobile station 106, signal strength estimations, such as received pilot power can be made. Channel quality estimator 335 is shown as a discrete block for clarity of discussion only. It is common for such a block to be incorporated within another block, such as receiver 320 or demodulator 325. Various types of signal strength estimates can be made, depending on which signal or which system type is being estimated. In general, any type of channel quality metric estimation block can be deployed in place of channel quality estimator 335 within the scope of the present invention. In a base station 104, the channel quality estimates are delivered to processor 350 for use in scheduling, or determining the reverse link quality, as described further below. Channel quality estimates may be used to determine whether up or down power control commands are required to drive either the forward or reverse link power to a desired set point. The desired set point may be determined with an outer loop power control mechanism. Signals are transmitted via antenna 310. Transmitted signals are formatted in transmitter 370 according to one or more wireless system standards, such as those listed above. Examples of components that may be included in transmitter 370 are amplifiers, filters, digital-to-analog (D/A) converters, radio frequency (RF) converters, and the like. Data for transmission is provided to transmitter 370 by modulator 365. Data and control channels can be formatted for transmission in accordance with a variety of formats. Data for transmission on the forward link data channel may be formatted in modulator 365 according to a rate and modulation format indicated by a scheduling algorithm in accordance with a C/I or other channel quality measurement. A scheduler, such as scheduler 240, described above, may reside in processor 350. Similarly, transmitter 370 may be directed to transmit at a power level in accordance with the scheduling algorithm. Examples of components, which may be incorporated in modulator 365, include encoders, interleavers, spreaders, and modulators of various types. A reverse link design, including example modulation formats and access control, suitable for deployment on a 1xEV-DV system is also described below. Message generator 360 may be used to prepare messages of various types, as described herein. For example, C/I messages may be generated in a mobile station for transmission on the reverse link. Various types of control messages may be generated in either a base station 104 or mobile station 106 for transmission on the forward or reverse links, respectively. For example, described below are request messages and grant messages for scheduling reverse link data transmission for generation in a mobile station or base station, respectively. Data received and demodulated in demodulator 325 may be delivered to processor 350 for use in voice or data communications, as well as to various other components. Similarly data for transmission may be directed to modulator 365 and transmitter 370 from processor 350. For example, various data applications may be present on processor 350, or on another processor included in the wireless communication device 104 or 106 (not shown). A base station 104 may be connected, via other equipment not shown, to one or more external networks, such as the Internet (not shown). A mobile station 106 may include a link to an external device, such as a laptop computer (not shown). Processor 350 may be a general-purpose microprocessor, a digital signal processor (DSP), or a special-purpose processor. Processor 350 may perform some or all of the functions of receiver 320, demodulator 325, message decoder 330, channel quality estimator 335, message generator 360, modulator 365, or transmitter 370, as well as any other processing required by the wireless communication device. Processor 350 may be connected with special-purpose hardware to assist in these tasks (details not shown). Data or voice applications may be external, such as an externally connected laptop computer or connection to a network, may run on an additional processor within wireless communication device 104 or 106 (not shown), or may run on processor 350 itself. Processor 350 is connected with memory 355, which can be used for storing data as well as instructions for performing the various procedures and methods described herein. Those of skill in the art will recognize that memory 355 may be comprised of one or more memory components of various types, that may be embedded in whole or in part within processor 350. A typical data communication system may include one or more channels of various types. More specifically, one or more data channels are commonly deployed. It is also common for one or more control channels to be deployed, although in-band control signaling can be included on a data channel. For example, in a 1xEV-DV system, a Forward Packet Data Control Channel (F-PDCCH) and a Forward Packet Data Channel (F-PDCH) are defined for transmission of control and data, respectively, on the forward link. Various example channels for reverse link data transmission are detailed as follows. 1xEV-DV Reverse Link Design Considerations In this section, various factors considered in the design of an example embodiment of a reverse link of a wireless communication system are described. In many of the embodiments, detailed further in following sections, signals, parameters, and procedures associated with the 1xEV-DV standard are used. This standard is described for illustrative purposes only, as each of the aspects described herein, and combinations thereof, may be applied to any number of communication systems within the scope of the present invention. This section serves as a partial summary of various aspects of the invention, although it is not exhaustive. Example embodiments are detailed further in subsequent sections below, in which additional aspects are described. In many cases, reverse link capacity is interference limited. Base stations allocate available reverse link communication resources to mobile stations for efficient utilization to maximize throughput in accordance with Quality of Service (QoS) requirements for the various mobile stations. Maximizing the use of the reverse link communication resource involves several factors. One factor to consider is the mix of scheduled reverse link transmissions from various mobile stations, each of which may be experiencing varying channel quality at any given time. To increase overall throughput (the aggregate data transmitted by all the mobile stations in the cell), it is desirable for the entire reverse link to be fully utilized whenever there is reverse link data to be sent. To fill the available capacity, mobile stations may be granted access at the highest rate they can support, and additional mobile stations may be granted access until capacity is reached. One factor a base station may consider in deciding which mobile stations to schedule is the maximum rate each mobile can support and the amount of data each mobile station has to send. A mobile station capable of higher throughput may be selected instead of an alternate mobile station whose channel does not support the higher throughput. Another factor to be considered is the quality of service required by each mobile station. While it may be permissible to delay access to one mobile station in hopes that the channel will improve, opting instead to select a better situated mobile station, it may be that suboptimal mobile stations may need to be granted access to meet minimum quality of service guarantees. Thus, the data throughput scheduled may not be the absolute maximum, but rather maximized considering channel conditions, available mobile station transmit power, and service requirements. It is desirable for any configuration to reduce the signal to noise ratio for the selected mix. Various scheduling mechanisms are described below for allowing a mobile station to transmit data on the reverse link. One class of reverse link transmission involves the mobile station making a request to transmit on the reverse link. The base station makes a determination of whether resources are available to accommodate the request. A grant can be made to allow the transmission. This handshake between the mobile station and the base station introduces a delay before the reverse link data can be transmitted. For certain classes of reverse link data, the delay may be acceptable. Other classes may be more delay-sensitive, and alternate techniques for reverse link transmission are detailed below to mitigate delay. In addition, reverse link resources are expended to make a request for transmission, and forward link resources are expended to respond to the request, i.e. transmit a grant. When a mobile station's channel quality is low, i.e. low geometry or deep fading, the power required on the forward link to reach the mobile may be relatively high. Various techniques are detailed below to reduce the number or required transmit power of requests and grants required for reverse link data transmission. To avoid the delay introduced by a request/grant handshake, as well as to conserve the forward and reverse link resources required to support them, an autonomous reverse link transmission mode is supported. A mobile station may transmit data at a limited rate on the reverse link without making a request or waiting for a grant. It may also be desirable to modify the transmission rate of a mobile station that is transmitting in accordance with a grant, or autonomously, without the overhead of a grant. To accomplish this, rate control commands may be implemented along with autonomous and request/grant based scheduling. For example, a set of commands may include a command to increase, decrease and hold steady the current rate of transmission. Such rate control commands may be addressable to each mobile station individually, or to groups of mobile stations. Various example rate control commands, channels, and signals are detailed further below. The base station allocates a portion of the reverse link capacity to one or more mobile stations. A mobile station that is granted access is afforded a maximum power level. In the example embodiments described herein, the reverse link resource is allocated using a Traffic to Pilot (T/P) ratio. Since the pilot signal of each mobile station is adaptively controlled via power control, specifying the T/P ratio indicates the available power for use in transmitting data on the reverse link. The base station may make specific grants to one or more mobile stations, indicating a T/P value specific to each mobile station. The base station may also make a common grant to the remaining mobile stations, which have requested access, indicating a maximum T/P value that is allowed for those remaining mobile stations to transmit. Autonomous and scheduled transmission, individual and common grants, and rate control are detailed further below. Various scheduling algorithms are known in the art, and more are yet to be developed, which can be used to determine the various specific and common T/P values for grants as well as desired rate control commands in accordance with the number of registered mobile stations, the probability of autonomous transmission by the mobile stations, the number and size of the outstanding requests, expected average response to grants, and any number of other factors. In one example, a selection is made based on Quality of Service (QoS) priority, efficiency, and the achievable throughput from the set of requesting mobile stations. One example scheduling technique is disclosed in co-pending U.S. patent application Ser. No. 10/651,810, entitled “SYSTEM AND METHOD FOR A TIME-SCALABLE PRIORITY-BASED SCHEDULER”, filed Aug. 28, 2003, assigned to the assignee of the present invention. Additional references include U.S. Pat. No. 5,914,950, entitled “METHOD AND APPARATUS FOR REVERSE LINK RATE SCHEDULING”, and U.S. Pat. No. 5,923,650, also entitled “METHOD AND APPARATUS FOR REVERSE LINK RATE SCHEDULING”, both assigned to the assignee of the present invention. A mobile station may transmit a packet of data using one or more subpackets, where each subpacket contains the complete packet information (each subpacket is not necessarily encoded identically, as various encoding or redundancy may be deployed throughout various subpackets). Retransmission techniques may be deployed to ensure reliable transmission, for example Automatic Repeat reQuest (ARQ). Thus, if the first subpacket is received without error (using a CRC, for example), a positive Acknowledgement (ACK) is sent to the mobile station and no additional subpackets will be sent (recall that each subpacket comprises the entire packet information, in one form or another). If the first subpacket is not received correctly, then a Negative Acknowledgement signal (NAK) is sent to the mobile station, and the second subpacket will be transmitted. The base station can combine the energy of the two subpackets and attempt to decode. The process may be repeated indefinitely, although it is common to specify a maximum number of subpackets. In example embodiments described herein, up to four subpackets may be transmitted. Thus, the probability of correct reception increases as additional subpackets are received. Detailed below are various ways to combine ARQ responses, rate control commands, and grants, to provide the desired level of flexibility in transmission rates with acceptable overhead levels. As just described, a mobile station may trade off throughput for latency in deciding whether to use autonomous transfer to transmit data with low latency or requesting a higher rate transfer and waiting for a common or specific grant. In addition, for a given T/P, the mobile station may select a data rate to suit latency or throughput. For example, a mobile station with relatively few bits for transmission may decide that low latency is desirable. For the available T/P (probably the autonomous transmission maximum in this example, but could also be the specific or common grant T/P), the mobile station may select a rate and modulation format such that the probability of the base station correctly receiving the first subpacket is high. Although retransmission will be available if necessary, it is likely that this mobile station will be able to transmit its data bits in one subpacket. In various example embodiments described herein, each subpacket is transmitted over a period of 5 ms. Therefore, in this example, a mobile station may make an immediate autonomous transfer that is likely to be received at the base station following a 5 ms interval. Note that, alternatively, the mobile station may use the availability of additional subpackets to increase the amount of data transmitted for a given T/P. So, a mobile station may select autonomous transfer to reduce latency associated with requests and grants, and may additionally trade the throughput for a particular T/P to minimize the number of subpackets (hence latency) required. Even if the full number of subpackets is selected, autonomous transfer will be lower latency than request and grant for relatively small data transfers. Those of skill in the art will recognize that as the amount of data to be transmitted grows, requiring multiple packets for transmission, the overall latency may be reduced by switching to a request and grant format, since the penalty of the request and grant will eventually be offset by the increased throughput of a higher data rate across multiple packets. This process is detailed further below, with an example set of transmission rates and formats that can be associated with various T/P assignments. Reverse Link Data Transmission One goal of a reverse link design may be to maintain the Rise-over-Thermal (RoT) at the base station relatively constant as long as there is reverse link data to be transmitted. Transmission on the reverse link data channel is handled in three different modes: Autonomous Transmission: This case is used for traffic requiring low delay. The mobile station is allowed to transmit immediately, up to a certain transmission rate, determined by the serving base station (i.e. the base station to which the mobile station directs its Channel Quality Indicator (CQI)). A serving base station is also referred to as a scheduling base station or a granting base station. The maximum allowed transmission rate for autonomous transmission may be signaled by the serving base station dynamically based on system load, congestion, etc. Scheduled Transmission: The mobile station sends an estimate of its buffer size, available power, and possibly other parameters. The base station determines when the mobile station is allowed to transmit. The goal of a scheduler is to limit the number of simultaneous transmissions, thus reducing the interference between mobile stations. The scheduler may attempt to have mobile stations in regions between cells transmit at lower rates so as to reduce interference to neighboring cells, and to tightly control RoT to protect the voice quality on the R-FCH, the DV feedback on R-CQICH and the acknowledgments (R-ACKCH), as well as the stability of the system. Rate Controlled Transmission: Whether a mobile station transmits scheduled (i.e. granted) or autonomously, a base station may adjust the transmission rate via rate control commands. Example rate control commands include increasing, decreasing, or holding the current rate. Additional commands may be included to specify how a rate change is to be implemented (i.e. amount of increase or decrease). Rate control commands may be probabilistic or deterministic. Various embodiments, detailed herein, contain one or more features designed to improve throughput, capacity, and overall system performance of the reverse link of a wireless communication system. For illustrative purposes only, the data portion of a 1xEV-DV system, in particular, optimization of transmission by various mobile stations on the Enhanced Reverse Supplemental Channel (R-ESCH), is described. Various forward and reverse link channels used in one or more of the example embodiments are detailed in this section. These channels are generally a subset of the channels used in a communication system. FIG. 4 depicts an exemplary embodiment of data and control signals for reverse link data communication. A mobile station 106 is shown communicating over various channels, each channel connected to one or more base stations 104A-104C. Base station 104A is labeled as the scheduling base station. The other base stations 104B and 104C are part of the Active Set of mobile station 106. There are four types of reverse link signals and four types of forward link signals shown. They are described below. R-REQCH The Reverse Request Channel (R-REQCH) is used by the mobile station to request from the scheduling base station a reverse link transmission of data. In the example embodiment, requests are for transmission on the R-ESCH (detailed further below). In the example embodiment, a request on the R-REQCH includes the T/P ratio the mobile station can support, variable according to changing channel conditions, and the buffer size (i.e. the amount of data awaiting transmission). The request may also specify the Quality of Service (QoS) for the data awaiting transmission. Note that a mobile station may have a single QoS level specified for the mobile station, or, alternately, different QoS levels for different types of service options. Higher layer protocols may indicate the QoS, or other desired parameters (such as latency or throughput requirements) for various data services. In an alternative embodiment, a Reverse Dedicated Control Channel (R-DCCH), used in conjunction with other reverse link signals, such as the Reverse Fundamental Channel (R-FCH) (used for voice services, for example), may be used to carry access requests. In general, access requests may be described as comprising a logical channel, i.e. a Reverse Schedule Request Channel (R-SRCH), which may be mapped onto any existing physical channel, such as the R-DCCH. The example embodiment is backward compatible with existing CDMA systems such as IS-2000 Revision C, and the R-REQCH is a physical channel that can be deployed in the absence of either the R-FCH or the R-DCCH. For clarity, the term R-REQCH is used to describe the access request channel in embodiment descriptions herein, although those of skill in the art will readily extend the principles to any type of access request system, whether the access request channel is logical or physical. The R-REQCH may be gated off until a request is needed, thus reducing interference and conserving system capacity. In the example embodiment, the R-REQCH has 12 input bits that consist of the following: 4 bits to specify the maximum R-ESCH T/P ratio that the mobile can support, 4 bits to specify the amount of data in the mobile's buffer, and 4 bits to specify the QoS. Those of skill in the art will recognize that any number of bits and various other fields may be included in alternate embodiments. F-GCH The Forward Grant Channel (F-GCH) is transmitted from the scheduling base station to the mobile station. The F-GCH may be comprised of multiple channels. In the example embodiment, a common F-GCH channel is deployed for making common grants, and one or more individual F-GCH channels are deployed for making individual grants. Grants are made by the scheduling base station in response to one or more requests from one or more mobile stations on their respective R-REQCHs. Grant channels may be labeled as GCHx, where the subscript x identifies the channel number. A channel number 0 may be used to indicate the common grant channel. If N individual channels are deployed, the subscript x may range from 1 to N. An individual grant may be made to one or more mobile stations, each of which gives permission to the identified mobile station to transmit on the R-ESCH at a specified T/P ratio or below. Making grants on the forward link will naturally introduce overhead that uses some forward link capacity. Various options for mitigating the overhead associated with grants are detailed herein, and other options will be apparent to those of skill in the art in light of the teachings herein. One consideration is that mobile stations will be situated such that each experiences varying channel quality. Thus, for example, a high geometry mobile station with a good forward and reverse link channel may need a relatively low power for grant signal, and is likely to be able to take advantage of a high data rate, and hence is desirable for an individual grant. A low geometry mobile station, or one experiencing deeper fading, may require significantly more power to receive an individual grant reliably. Such a mobile station may not be the best candidate for an individual grant. A common grant for this mobile station, detailed below, may be less costly in forward link overhead. In the example embodiment, a number of individual F-GCH channels are deployed to provide the corresponding number of individual grants at a particular time. The F-GCH channels are code division multiplexed. This facilitates the ability to transmit each grant at the power level required to reach just the specific intended mobile station. In an alternative embodiment, a single individual grant channel may be deployed, with the number of individual grants time multiplexed. To vary the power of each grant on a time multiplexed individual F-GCH may introduce additional complexity. Any signaling technique for delivering common or individual grants may be deployed within the scope of the present invention. In some embodiments, a relatively large number of individual grant channels (i.e. F-GCHs) are deployed to allow for a relatively large number of individual grants at one time. In such a case, it may be desirable to limit the number of individual grant channels each mobile station has to monitor. In one example embodiment, various subsets of the total number of individual grant channels are defined. Each mobile station is assigned a subset of individual grant channels to monitor. This allows the mobile station to reduce processing complexity, and correspondingly reduce power consumption. The tradeoff is in scheduling flexibility, since the scheduling base station may not be able to arbitrarily assign sets of individual grants (e.g., all individual grants can not be made to members of a single group, since those members, by design, do not monitor one or more of the individual grant channels). Note that this loss of flexibility does not necessarily result in a loss of capacity. For illustration, consider an example including four individual grant channels. The even numbered mobile stations may be assigned to monitor the first two grant channels, and the odd numbered mobile stations may be assigned to monitor the last two. In another example, the subsets may overlap, such as the even mobile stations monitoring the first three grant channels, and the odd mobile stations monitoring the last three grant channels. It is clear that the scheduling base station cannot arbitrarily assign four mobile stations from any one group (even or odd). These examples are illustrative only. Any number of channels with any configuration of subsets may be deployed within the scope of the present invention. The remaining mobile stations, having made a request, but not receiving an individual grant, may be given permission to transmit on the R-ESCH using a common grant, which specifies a maximum T/P ratio that each of the remaining mobile stations must adhere to. The common F-GCH may also be referred to as the Forward Common Grant Channel (F-CGCH). A mobile station monitors the one or more individual grant channels (or a subset thereof) as well as the common F-GCH. Unless given an individual grant, the mobile station may transmit if a common grant is issued. The common grant indicates the maximum T/P ratio at which the remaining mobile stations (the common grant mobile stations) may transmit for the data with certain type of QoS. In the example embodiment, each common grant is valid for a number of subpacket transmission intervals. Once receiving a common grant, a mobile station that has sent a request, but doesn't get an individual grant may start to transmit one or more encoder packets within the subsequent transmission intervals. The grant information may be repeated multiple times. This allows the common grant to be transmitted at a reduced power level with respect to an individual grant. Each mobile station may combine the energy from multiple transmissions to reliably decode the common grant. Therefore, a common grant may be selected for mobile stations with low-geometry, for example, where an individual grant is deemed too costly in terms of forward link capacity. However, common grants still require overhead, and various techniques for reducing this overhead are detailed below. The F-GCH is sent by the base station to each mobile station that the base station schedules for transmission of a new R-ESCH packet. It may also be sent during a transmission or a retransmission of an encoder packet to force the mobile station to modify the T/P ratio of its transmission for the subsequent subpackets of the encoder packet in case congestion control becomes necessary. In the example embodiment, the common grant consists of 12 bits including a 3-bit type field to specify the format of the next nine bits. The remaining bits indicate the maximum allowed T/P ratio for 3 classes of mobiles as specified in the type field, with 3 bits denoting the maximum allowable T/P ratio for each class. The mobile classes may be based on QoS requirements, or other criterion. Various other common grant formats are envisioned, and will be readily apparent to one of ordinary skill in the art. In the example embodiment, an individual grant comprises 12 bits including: 11 bits to specify the Mobile ID and maximum allowed T/P ratio for the mobile station being granted to transmit, or to explicitly signal the mobile station to change its maximum allowed T/P ratio, including setting the maximum allowed T/P ratio to 0 (i.e., telling the mobile station not to transmit the R-ESCH). The bits specify the Mobile ID (1 of 192 values) and the maximum allowed T/P (1 of 10 values) for the specified mobile. In an alternate embodiment, 1 long-grant bit may be set for the specified mobile. When the long-grant bit is set to one, the mobile station is granted permission to transmit a relatively large fixed, predetermined number (which can be updated with signaling) of packets on that ARQ channel. If the long-grant bit is set to zero, the mobile station is granted to transmit one packet. A mobile may be told to turn off its R-ESCH transmissions with the zero T/P ratio specification, and this may be used to signal the mobile station to turn off its transmission on the R-ESCH for a single subpacket transmission of a single packet if the long-grant bit is off or for a longer period if the long-grant bit is on. In one example embodiment, the mobile station only monitors the F-GCH(s) from the Serving base station. If the mobile station receives an F-GCH message, then the mobile station follows the rate information in the F-GCH message and ignores the rate control bits. An alternative would be for the mobile station to use the rule that if any rate control indicator from a base station other than the serving base station indicates a rate decrease (i.e., the RATE_DECREASE command, detailed below) then the mobile station will decrease its rate even if the F-GCH indicates an increase. In an alternative embodiment, the mobile station may monitor the F-GCH from all base stations or a subset of the base stations in its Active Set. Higher layer signaling indicates to the mobile station which F-GCH(s) to monitor and how to combine them at channel assignment, through a hand-off direction message, or other messages. Note that a subset of F-GCHs from different base stations may be soft combined. The mobile station will be notified of this possibility. After the possible soft combining of the F-GCHs from different base stations, there may still be multiple F-GCHs at any one time. The mobile station may then decide its transmit rate as the lowest granted rate (or some other rule). R-PICH The Reverse Pilot Channel (R-PICH) is transmitted from the mobile station to the base stations in the Active Set. The power in the R-PICH may be measured at one or more base stations for use in reverse link power control. As is well known in the art, pilot signals may be used to provide amplitude and phase measurements for use in coherent demodulation. As described above, the amount of transmit power available to the mobile station (whether limited by the scheduling base station or the inherent limitations of the mobile station's power amplifier) is split among the pilot channel, traffic channel or channels, and control channels. Additional pilot power may be needed for higher data rates and modulation formats. To simplify the use of the R-PICH for power control, and to avoid some of the problems associated with instantaneous changes in required pilot power, an additional channel may be allocated for use as a supplemental or secondary pilot. Although, generally, pilot signals are transmitted using known data sequences, as disclosed herein, an information bearing signal may also be deployed for use in generating reference information for demodulation. In an example embodiment, the R-RICH is used to carry the additional pilot power desired. R-RICH The Reverse Rate Indicator Channel (R-RICH) is used by the mobile station to indicate the transmission format on the reverse traffic channel, R-ESCH. This channel may be alternately referred to as the Reverse Packet Data Control Channel (R-PDCCH). The R-RICH may be transmitted whenever the mobile station is transmitting a subpacket. The R-RICH may also be transmitted with zero-rate indication when the mobile station is idle on R-ESCH. Transmission of zero-rate R-RICH frames (an R-RICH that indicates the R-ESCH is not being transmitted) helps the base station detect that the mobile station is idle, maintain reverse link power control for the mobile station, and other functions. The beginning of an R-RICH frame is time aligned with the beginning of the current R-ESCH transmission. The frame duration of R-RICH may be identical to or shorter than that of the corresponding R-ESCH transmission. The R-RICH conveys the transmit format of the concurrent R-ESCH transmission, such as payload, subpacket ID and ARQ Instance Sequence Number (AISN) bit, and CRC for error detection. An example AI_SN is a bit that flips every time a new packet is transmitted on a particular ARQ, sometimes referred to as a “color bit”. This may be deployed for asynchronous ARQ, in which there is no fixed timing between subpacket transmissions of a packet. The color bit may be used to prevent the receiver from combining subpacket(s) for one packet with the subpacket(s) of an adjacent packet on the same ARQ channel. The R-RICH may also carry additional information. R-ESCH The Enhanced Reverse Supplemental Channel (R-ESCH) is used as the reverse link traffic data channel in the example embodiments described herein. Any number of transmission rates and modulation formats may be deployed for the R-ESCH. In an example embodiment, the R-ESCH has the following properties: Physical layer retransmissions are supported. For retransmissions when the first code is a Rate 1/4 code, the retransmission uses a Rate 1/4 code and energy combining is used. For retransmissions when the first code is a rate greater than 1/4, incremental redundancy is used. The underlying code is a Rate 1/5 code. Alternatively, incremental redundancy could also be used for all the cases. Hybrid Automatic-Repeat-Request (HARQ) is supported for both autonomous and scheduled users, both of which may access the R-ESCH. Multiple ARQ-channel synchronous operation may be supported with fixed timing between the retransmissions: a fixed number of sub-packets between consecutive sub-packets of same packet may be allowed. Interlaced transmissions are allowed as well. As an example, for 5 ms frames, 4 channel ARQ could be supported with 3 subpacket delay between subpackets. Table 1 lists example data rates for the Enhanced Reverse Supplemental Channel. A 5 ms subpacket size is described, and the accompanying channels have been designed to suit this choice. Other subpacket sizes may also be chosen, as will be readily apparent to those of skill in the art. The pilot reference level is not adjusted for these channels, i.e. the base station has the flexibility of choosing the T/P to target a given operating point. This max T/P value is signaled on the Forward Grant Channel. The mobile station may use a lower T/P if it is running out of power to transmit, letting HARQ meet the required QoS. Layer 3 signaling messages may also be transmitted over the R-ESCH, allowing the system to operate without the R-FCH and/or R-DCCH. TABLE 1 Enhanced Reverse Supplemental Channel Parameters Number Symbol Number of Effective of Number Data Repetition Binary Code Code Bits per of Data Rate/ Factor Symbols in Rate Encoder 5-ms Rate 9.6 Code Before the Walsh All the Including Packet Slots (kbps) kbps Rate Interleaver Modulation Channels Subpackets Repetition 192 4 9.6 1.000 1/4 2 BPSK on I ++−− 6,144 1/32 192 3 12.8 1.333 1/4 2 BPSK on I ++−− 4,608 1/24 192 2 19.2 2.000 1/4 2 BPSK on I ++−− 3,072 1/16 192 1 38.4 4.000 1/4 2 BPSK on I ++−− 1,536 1/8 384 4 19.2 2.000 1/4 1 BPSK on I ++−− 6,144 1/16 384 3 25.6 2.667 1/4 1 BPSK on I ++−− 4,608 1/12 384 2 38.4 4.000 1/4 1 BPSK on I ++−− 3,072 1/8 384 1 76.8 8.000 1/4 1 BPSK on I ++−− 1,536 1/4 768 4 76.8 4.000 1/4 1 QPSK ++−− 12,288 1/16 768 3 102.4 5.333 1/4 1 QPSK ++−− 9,216 1/12 768 2 153.6 8.000 1/4 1 QPSK ++−− 6,144 1/8 768 1 307.2 16.000 1/4 1 QPSK ++−− 3,072 1/4 1,536 4 76.8 8.000 1/4 1 QPSK +− 24,576 1/16 1,536 3 102.4 10.667 1/4 1 QPSK +− 18,432 1/12 1,536 2 153.6 16.000 1/4 1 QPSK +− 12,288 1/8 1,536 1 307.2 32.000 1/4 1 QPSK +− 6,144 1/4 2,304 4 115.2 12.000 1/4 1 QPSK ++−−/+− 36,864 1/16 2,304 3 153.6 16.000 1/4 1 QPSK ++−−/+− 27,648 1/12 2,304 2 230.4 24.000 1/4 1 QPSK ++−−/+− 18,432 1/8 2,304 1 460.8 48.000 1/4 1 QPSK ++−−/+− 9,216 1/4 3,072 4 153.6 16.000 1/5 1 QPSK ++−−/+− 36,864 1/12 3,072 3 204.8 21.333 1/5 1 QPSK ++−−/+− 27,648 1/9 3,072 2 307.2 32.000 1/5 1 QPSK ++−−/+− 18,432 1/6 3,072 1 614.4 64.000 1/5 1 QPSK ++−−/+− 9,216 1/3 4,608 4 230.4 24.000 1/5 1 QPSK ++−−/+− 36,864 1/8 4,608 3 307.2 32.000 1/5 1 QPSK ++−−/+− 27,648 1/6 4,608 2 460.8 48.000 1/5 1 QPSK ++−−/+− 18,432 1/4 4,608 1 921.6 96.000 1/5 1 QPSK ++−−/+− 9,216 1/2 6,144 4 307.2 32.000 1/5 1 QPSK ++−−/+− 36,864 1/6 6,144 3 409.6 42.667 1/5 1 QPSK ++−−/+− 27,648 2/9 6,144 2 614.4 64.000 1/5 1 QPSK ++−−/+− 18,432 1/3 6,144 1 1228.8 128.000 1/5 1 QPSK ++−−/+− 9,216 2/3 In an example embodiment, turbo coding is used for all the rates. With R=1/4 coding, an interleaver similar to the current cdma2000 reverse link is used. With R=1/5 coding, an interleaver similar to the cdma2000 Forward Packet Data Channel is used. The number of bits per encoder packet includes the CRC bits and 6 tail bits. For an encoder packet size of 192 bits, a 12-bit CRC is used; otherwise, a 16-bit CRC is used. The 5-ms slots are assumed to be separated by 15 ms to allow time for ACK/NAK responses. If an ACK is received, the remaining slots of the packet are not transmitted. The 5 ms subpacket duration, and associated parameters, just described, serve as an example only. Any number of combinations of rates, formats, subpacket repetition options, subpacket duration, etc. will be readily apparent to those of skill in the art in light of the teaching herein. An alternate 10 ms embodiment, using 3 ARQ channels, could be deployed. In one embodiment, a single subpacket duration or frame size is selected. For example, either a 5 ms or 10 ms structure would be selected. In an alternate embodiment, a system may support multiple frame durations. F-CPCCH The Forward Common Power Control Channel (F-CPCCH) may be used to power control various reverse link channels, including the R-ESCH when the F-FCH and the F-DCCH are not present, or when the F-FCH and the F-DCCH are present but not dedicated to a user. Upon channel assignment, a mobile station is assigned a reverse link power control channel. The F-CPCCH may contain a number of power control subchannels. The F-CPCCH may carry a power control subchannel called the Common Congestion Control subchannel (F-OLCH). The exemplary congestion control subchannel is typically at a rate of 100 bps, though other rates can be used. The single bit (which may be repeated for reliability), referred to herein as the busy bit, indicates the mobile stations in autonomous transmission mode, or in the common grant mode, or both, whether to increase or decrease their rate. In an alternate embodiment, individual grant modes may be also be sensitive to this bit. Various embodiments may be deployed with any combination of transmission types responsive to the F-OLCH. This can be done in a probabilistic manner, or deterministically. In one embodiment, setting the busy bit to ‘0’ indicates that mobile stations responsive to the busy bit should decrease their transmission rate. Setting the busy bit to ‘1’ indicates a corresponding increase in transmission rate. Myriad other signaling schemes may be deployed, as will be readily apparent to those of skill in the art, and various alternate examples are detailed below. During channel assignment, the mobile station is assigned to these special power control channels. A power control channel may control all the mobiles in the system, or alternatively, varying subsets of the mobile stations may be controlled by one or more power control channels. Note that use of this particular channel for congestion control is but one example. F-ACKCH The Forward Acknowledgement Channel, or F-ACKCH, is used by a base station to acknowledge the correct reception of the R-ESCH, and can also be used to extend an existing grant. An acknowledgement (ACK) on the F-ACKCH indicates correct reception of a subpacket. Additional transmission of that subpacket by the mobile station is unnecessary. A negative acknowledgement (NAK) on the F-ACKCH allows the mobile station to transmit another subpacket, limited by a maximum allowed number of subpackets per packet. In embodiments detailed herein, the F-ACKCH is used to provide positive or negative acknowledgment of a received subpacket, as well as an indication of whether or not rate control commands will be issued (described below with respect to the F-RCCH channel). FIG. 5 is an example embodiment illustrating a tri-valued F-ACKCH. This example F-ACKCH consists of a single indicator, transmitted from one or more base stations to a mobile station, to indicate whether or not the transmission on the R-ESCH from the mobile station has been received correctly by the respective base station. In an example embodiment, the F-ACKCH indicator is transmitted by every base station in the Active Set. Alternatively, the F-ACKCH may be transmitted by a specified subset of the Active Set. The set of base stations sending the F-ACKCH may be referred to as the F-ACKCH Active Set. The F-ACKCH Active Set may be signaled by Layer 3 (L3) signaling to the mobile station and may be specified during channel assignment, in a Handoff Direction message (HDM), or via other techniques known in the art. For example, F-ACKCH may be a 3-state channel with the following values: NAK, ACK_RC, and ACK_STOP. A NAK indicates that the packet from the mobile station has to be retransmitted (however, if the last subpacket has been sent, the mobile station may need to resend the packet using any of the techniques available, such as request/grant, rate control, or autonomous transmission). The mobile station may need to monitor the Rate Control indicator on the corresponding F-RCCH (detailed further below) if the NAK corresponds to last subpacket of a packet. An ACK_RC indicates that no retransmissions of the packet from the mobile station are necessary, and the mobile station should monitor the Rate Control indicator on the corresponding F-RCCH. ACK_STOP also indicates no retransmission is necessary. However, in this case, the mobile station should revert to autonomous mode for the next transmission unless the mobile station receives a grant message on the F-GCH (detailed above). L3 signaling may indicate whether or not the mobile station is to soft-combine the F-ACKCH indicators from different base stations in its Active Set. This may be equivalent to handling the power control bits in accordance with Revision C of IS-2000. For example, there may be an indicator, say ACK_COMB_IND, sent upon channel assignment and in handoff messages that would indicate whether the mobile station is to combine the F-ACKCH indicators from different base stations. A variety of techniques may be employed for transmitting the F-ACKCH, examples of which are given below. Some examples include a separate TDM channel, a TDM/CDM channel, or some other format. In this example, there are two classes of results from monitoring the F-ACK channels, depending on whether the packet is acknowledged or not. If a NAK is received, a variety of options are available. The mobile station may send additional subpackets until the maximum number of subpackets has been sent. (In the example embodiment, the subpackets are sent using the same transmission format, whether initiated through autonomous or granted transmission, and whether or not subject to a rate control revision. In an alternate embodiment, the subpacket transmission format may be altered using any of the techniques disclosed herein). Subsequent to a NAK of the final subpacket, the mobile station may either take action relative to corresponding rate control commands (monitor the F-RCCH), stop transmitting according to the previous grant or rate control command (i.e. revert to autonomous transmission, if desired), or respond to a new received grant. If an ACK is received, it may correspond to a rate control command or an indication to stop. If rate control is indicated, the rate control channel (F-RCCH) is monitored and followed. If the outcome is to stop, then the mobile station does not follow the rate control indicators on the F-RCCH and reverts to the autonomous mode (transmitting up to the assigned maximum autonomous rate). If an explicit grant is received at the same time as an ACK_STOP, then the mobile station follows the command in the explicit grant. For example, first consider a single Active Set Member or the case when the indicators from all sectors are the same (and are so indicated by ACK_COMB_IND). In this case, there is a single resultant indicator. When the mobile station receives a NAK (indicator not transmitted), then the mobile station retransmits the next subpacket (at the appropriate time). If the mobile station does not receive an ACK for the last subpacket, then the mobile station goes on to the next packet (the errant packet may be retransmitted according to whatever retransmission algorithm is being followed). However, the mobile station takes this as a rate control indication (i.e. monitors the rate control channel). In this example, a general rule is as follows (applicable to both a single Active Set member and multiple distinctive F-ACKCH Active Set members). If any indicator is an ACK_STOP or ACK_RC, the result is an ACK. If none of the indicators is an ACK_STOP or ACK_RC, the result is a NAK. Then, in relation to rate control, if any indicator is an ACK_STOP, the mobile station will stop (i.e. revert to autonomous mode, or respond to a grant, if any). If no indicator is an ACK_STOP and at least one indicator is an ACK_RC, decode the indicator on the rate control channel (F-RCCH) of the corresponding base station. If the last subpacket has been transmitted, and all indicators are NAK, decode the indicator on the rate control channels (F-RCCH) of all the base stations. Responding to the rate control commands in these scenarios is detailed further below with respect to the description of F-RCCH. An ACK_RC command, combined with the rate control channel, may be thought of as a class of commands referred to as ACK-and-Continue commands. The mobile station may continue transmitting subsequent packets, continuing in accordance with the various rate control commands that may be issued (examples detailed below). An ACK-and-Continue command allows the base station to acknowledge successful reception of a packet and, at the same time, permit the mobile station to transmit using the grant that led to the successfully received packet (subject to possible revisions according to the rate control commands). This saves the overhead of a new grant. In the embodiment of the F-ACKCH, depicted in FIG. 5, a positive value for the ACK_STOP symbol, a NULL symbol for the NAK, and a negative value for the ACK_RC symbol is used. On-off keying (i.e., not sending NAK) on the F-ACKCH allows the base stations (especially non-scheduling base stations) an option of not sending an ACK when the cost (required power) of doing so is too high. This provides the base station a trade-off between the forward link and reverse link capacity, since a correctly received packet that is not ACKed will likely trigger a re-transmission at a later point in time. A variety of techniques for sending the F-ACKCH may be deployed within the scope of the present invention. Individual signals for each mobile station may be combined in a common channel. For example, acknowledgement responses for a plurality of mobile stations may be time multiplexed. In an example embodiment, up to 96 Mobile IDs can be supported on one F-ACKCH. Additional F-ACKCHs may be deployed to support additional Mobile IDs. Another example is to map a plurality of acknowledgement signals for a plurality of mobile stations onto a set of orthogonal functions. A Hadamard Encoder is one example of an encoder for mapping onto a set of orthogonal functions. Various other techniques may also be deployed. For example, any Walsh Code or other similar error correcting code may be used to encode the information bits. Different users may be transmitted to at different power levels if independent each subchannel has an independent channel gain. The exemplary F-ACKCH conveys one dedicated tri-valued flag per user. Each user monitors the F-ACKCH from all base stations in its Active Set (or, alternatively, signaling may define a reduced active set to reduce complexity). In various embodiments, two channels are each covered by a 128-chip Walsh cover sequence. One channel is transmitted on the I channel, and the other is transmitted on the Q channel. Another embodiment of the F-ACKCH uses a single 128-chip Walsh cover sequence to support up to 192 mobile stations simultaneously. An example embodiment uses a 10-ms duration for each tri-valued flag. To review, when the mobile station has a packet to send that requires usage of the R-ESCH, it may request on the R-REQCH. The base station may respond with a grant using an F-GCH. However, this operation may be somewhat expensive. To reduce the forward link overhead, F-ACKCH may send the ACK_RC flag, which extends the existing grant (subject to rate control) at low cost by the scheduling base station (or others, when soft handoff grants from multiple base stations are supported). This method works for both individual and common grants. ACK_RC is used from the granting base station (or base stations), and extends the current grant for one more encoder packet on the same ARQ channel (subject to rate control). Note that, as shown in FIG. 4, not every base station in the Active Set is required to send back the F-ACKCH. The set of base stations sending the F-ACKCH in soft handoff may be a subset of the Active Set. Example techniques for transmitting the F-ACKCH are disclosed in co-pending U.S. patent application Ser. No. 10/611,333, entitled “CODE DIVISION MULTIPLEXING COMMANDS ON A CODE DIVISION MULTIPLEXED CHANNEL”, filed Jun. 30, 2003, assigned to the assignee of the present invention. F-RCCH The Forward Rate Control Channel (F-RCCH) is transmitted from one or more base stations to a mobile station to signal a rate adjustment for the next transmission. A mobile station may be assigned to monitor the indicator from every member of the F-ACKCH Active Set or a subset thereof. For clarity, the set of base stations sending the F-RCCH to be monitored by the mobile station will be referred to as the F-RCCH Active Set. The F-RCCH Active Set may be signaled by Layer 3 (L3) signaling, which may be specified during channel assignment, in a Hand-Off Direction message (HDM), or any of various other ways known to those of skill in the art. FIG. 6 depicts an exemplary F-RCCH. The F-RCCH is a 3-state channel with the following values: RATE_HOLD, indicating the mobile station can transmit the next packet at no more than the same rate of current packet; RATE_INCREASE, indicating that the mobile station can, either deterministically or probabilistically, increase the maximum rate to transmit the next packet relative to the transmit rate of current packet; and RATE_DECREASE, indicating that the mobile station can, either deterministically or probabilistically, decrease the maximum rate to transmit the next packet relative to the transmit rate of current packet. L3 signaling may indicate whether or not the mobile station is to combine the Rate Control indicators from different base stations. This is similar to what is done with the power control bits in IS-2000 Rev. C. Thus, there would be an indicator, for example RATE_COMB_IND, sent upon channel assignment, and in handoff messages, that would indicate whether the mobile station is to soft-combine the F-RCCH bits from different base stations. Those of skill in the art will recognize that there are many formats for transmitting channels such as the F-RCCH, including separate TDM channels, combined TDM/CDM channels, or other formats. In various embodiments, various rate control configurations are possible. For example, all mobile stations may be controlled by a single indicator per sector. Alternatively, each mobile station may be controlled by a separate indicator per sector dedicated to each mobile station. Or, groups of mobile stations may be controlled by their own assigned indicator. Such a configuration allows mobile stations with the same maximum QoS grade to be assigned the same indicator. For example, all mobile stations whose only stream is designated “best effort” may be controlled by one assigned indicator, thus allowing a reduction in load for these best effort streams. In addition, signaling may be used to configure a mobile station so that the mobile station only pays attention to the F-RCCH indicator from the Serving Base Station or from all base stations in the F-RCCH Active Set. Note that if the mobile station is only monitoring the indicator from the Serving Base Station and RATE_COMB_IND specifies that the indicator is the same from multiple base stations, then the mobile station may combine all indicators in the same group as the Serving Base Station before making a decision. The set of base stations with distinctive rate control indicators in use at any time will be referred to as the F-RCCH Current Set. Thus, if the mobile station is configured so that the mobile station only pays attention to the F-RCCH indicator from the Serving Base Station, then the size of the F-RCCH Current Set is 1. It is envisioned that the usage rules for the F-RCCH may be adjusted by the base station. The following is an example set of rules for a mobile station with a single-member F-RCCH Current Set. If a RATE_HOLD is received, the mobile station does not change its rate. If a RATE_INCREASE is received, the mobile station increases its rate by one (i.e. one rate level, examples of which are detailed above in Table 1). If a RATE_DECREASE is received, the mobile station decreases its rate by one. Note that the mobile station monitors these indicators only when circumstances dictate (i.e. the action as a result of the ACK process, detailed further below, indicating rate control is active). The following is an example set of rules for a mobile station with multiple F-RCCH Current Set members. The simple rule of increasing/decreasing the rate by 1 rate is modified. If any ACK_STOP is received, the mobile station reverts to autonomous rates. Otherwise, if any indicator is a RATE_DECREASE, the mobile station decreases its rate by one. If no indicator is a RATE_DECREASE, and at least one base station has an action of rate control (as a result of the ACK process) that indicates RATE_HOLD, then the mobile station maintains the same rate. If no indicator is a RATE_DECREASE, no base station indicates rate control and RATE_HOLD, and at least one base station has an action of rate control and an indication of RATE_INCREASE; then the mobile station increases its rate by one. Example Combined Grant, ARO, and Rate Control Command Embodiments To summarize some of the aspects introduced above, mobile stations may be authorized to make autonomous transmissions, which, while perhaps limited in throughput, allow for low delay. In such a case, the mobile station may transmit without request up to a max R-ESCH T/P ratio, T/PMax_auto, which may be set and adjusted by the base station through signaling. Scheduling may be determined at one or more scheduling base stations, and allocations of reverse link capacity may be made through grants transmitted on the F-GCH at a relatively high rate. Additionally, rate control commands may be used to modify previously granted transmissions or autonomous transmissions, with low overhead, thus tuning the allocation of reverse link capacity. Scheduling may thus be employed to tightly control the reverse link load and thus protect voice quality (R-FCH), DV feedback (R-CQICH) and DV acknowledgement (R-ACKCH). An individual grant allows detailed control of a mobile station's transmission. Mobile stations may be selected based upon geometry and QoS to maximize throughput while maintaining required service levels. A common grant allows efficient notification, especially for low geometry mobile stations. The F-ACKCH channel in combination with the F-RCCH channel effectively implements “ACK-and-Continue” commands, which extend existing grants at low cost. (The continuation may be rate controlled, as described above, and detailed further below). This works with both individual grants and common grants. Various embodiments and techniques for scheduling, granting, and transmitting on a shared resource, such as a 1xEV-DV reverse link, are disclosed in co-pending U.S. patent application Ser. No. 10/646,955, entitled “SCHEDULED AND AUTONOMOUS TRANSMISSION AND ACKNOWLEDGEMENT”, filed Aug. 21, 2003, assigned to the assignee of the present invention, and incorporated by reference herein. FIG. 7 depicts example method 700 that one or more base stations may deploy to allocate capacity in response to requests and transmissions from one or more mobile stations. Note that the order of blocks shown is but one example, and the order of the various blocks may be interchanged or combined with other blocks, not shown, without departing from the scope of the present invention. The process starts at block 710. The base station receives any requests for transmission that may be transmitted by one or more mobile stations. As method 700 may be iterated indefinitely, there may be prior requests also received that may not have been granted, which may be combined with new requests to estimate the amount of demand for transmission according to requests. In block 720, one or more mobile stations may transmit subpackets that are received by the base station. These transmitted subpackets may have been transmitted in accordance with previous grants (potentially modified with previous rate control commands) or autonomously (also potentially modified with previous rate control commands). The number of autonomous transmissions, the number of registered mobile stations, and/or other factors may be used to estimate the amount of demand for autonomous transmission. In block 730, the base station decodes any received subpackets, optionally soft-combining with respective previously received subpackets, to determine whether the packets have been received without error. These decisions will be used to send a positive or negative acknowledgement to the respective transmitting mobile stations. Recall that HARQ may be used for packet transmission on the R-ESCH. That is, a packet may be transmitted up to certain number of times until it is received correctly by at least one base station. At each frame boundary, each base station decodes the R-RICH frame and determines the transmit format on the R-ESCH. A base station may also make this determination using the current R-RICH frame and previous R-RICH frames. Alternatively, a base station may also make the determination using other information extracted from a Reverse Secondary Pilot Channel (R-SPICH) and/or the R-ESCH. With the determined transmit format, the base station attempts to decode the packet on the R-ESCH, using previously received subpackets, as appropriate. In block 740, the base station performs scheduling. Any scheduling technique may be deployed. The base station may factor in demand for transmission according to requests, anticipated autonomous transmission, estimates of current channel conditions, and/or various other parameters in order to perform scheduling to allocate the shared resource (reverse link capacity, in this example). Scheduling may take various forms for the various mobile stations. Examples include making a grant (allocating according to a request, increasing a previous grant or reducing a previous grant), generating a rate control command to increase, decrease, or hold a previously granted rate or autonomous transmission, or ignoring a request (relegating the mobile station to autonomous transmission). In step 750, the base station processes the received transmissions for each mobile station. This may include, among other functions, acknowledging received subpackets, and conditionally generating grants in response to requests for transmission. FIG. 8 depicts example method 750 of generating grants, acknowledgements, and rate control commands. It is suitable for deployment in the example method 700 depicted in FIG. 7, and may be adapted for use with other methods, as will be readily apparent to those of ordinary skill in the art. Method 750 may be iterated for each active mobile station during each pass through method 700, as described above. In decision block 805, if a subpacket for the mobile station currently being processed has not been received, proceed to block 810. There is no acknowledgement necessary, and no rate control command to issue. Neither the F-ACKCH nor the F-RCCH need to be transmitted, and both symbols may be DTXed (not transmitted). In decision block 815, if a request has been received, proceed to decision block 820. Otherwise the process may stop. In decision block 820, if a grant has been determined for this mobile station during scheduling, proceed to block 825 to transmit the grant on the appropriate F-GCH. Then the process may stop. The mobile station may transmit in accordance with this grant during the next appropriate frame (timing examples are detailed below with respect to FIGS. 10-12). Returning to decision block 805, if a subpacket from the mobile station was received, proceed to decision block 830. (Note that it is possible for a subpacket and a request to be received, in which case both branches out of decision block 805 may be performed for a mobile station, details not shown for clarity of discussion). In decision block 830, if the received subpacket was decoded correctly, an ACK will be generated. Proceed to decision block 835. If rate control is desired (including a rate hold, i.e. “Continue”), proceed to block 845. If no rate control is desired, proceed to block 840. In block 840, an ACK_STOP is transmitted on F-ACKCH. F-RCCH need not be transmitted, i.e. a DTX may be generated. If no grant is generated at this time, the mobile station will be relegated to autonomous transmission (or must stop, if autonomous transmission is not available, or not deployed). Alternatively, a new grant may be issued which will override the stop command. Proceed to decision block 820 to process this decision, as described above. In block 845, rate control was indicated. As such, an ACK_RC will be transmitted on F-ACKCH. Proceed to decision block 850. If an increase is desired, transmit a RATE_INCREASE on F-RCCH. Then the process may stop. If an increase is not desired, proceed to decision block 860. In decision block 860, if a decrease is desired, transmit a RATE_DECREASE on F-RCCH. Then the process may stop. Otherwise, transmit a RATE_HOLD on F-RCCH. In this example, a hold is indicated by a DTX. Then the process may stop. Returning to decision block 830, if the received subpacket was not decoded correctly, a NAK will be generated. Proceed to block 875 to transmit a NAK on F-ACKCH. In this example, a NAK is indicated by a DTX. Proceed to decision block 880 to determine if the received subpacket was the last subpacket (i.e. the maximum number of subpacket retransmissions has been reached). If not, in this example, the mobile station may retransmit according to the previous transmission format. A DTX may be transmitted on F-RCCH, as indicated in block 895. (Alternative embodiments may perform alternate signaling in this case, examples of which are described below.) Then the process may stop. If the received, and NAKed, subpacket is the last subpacket, proceed from decision block 880 to decision block 885 to determine if rate control (including a hold) is desired. This is an example technique for extending the previous grant or autonomous transmission (including previous rate control, if any), with low overhead. If no rate control is desired, a DTX is generated for the F-RCCH. In this example, the mobile station will transmit the next subpacket. Similar to decision block 835, if a new grant is not generated for the mobile station, the mobile station will be relegated to autonomous transmission (if available). Alternatively, a new grant may be generated, which will dictate the available transmission for the mobile station. Proceed to decision block 820 to perform this determination, as described above. In decision block 885, if rate control is desired, proceed to decision block 850. An increase, decrease, or hold may be generated for transmission on F-RCCH, as described above. Then the process may stop. In summary, if a packet is received correctly, the base station may send positive acknowledgement and conditionally may send a rate control message to the mobile station. The base station may send an ACK_STOP (on F-ACKCH) to signal that the packet has been delivered and the mobile station reverts to autonomous mode for the next transmission. The base station may also send a new grant, if desired. The mobile station may transmit up to the granted rate for the next transmission. In either case, F-RCCH is DTXed. In one embodiment, only a serving (or granting) base station may generate grants. In an alternate embodiment, one or more base stations may generate grants (details for handling this option are detailed below). The base station may send ACK_RC (on F-ACKCH) and RATE_HOLD (on F-RCCH) to signal that the packet was delivered and that the maximum rate the mobile station may transmit the next packet is same as the transmit rate of the current packet. The base station may send ACK_RC (on F-ACKCH) and RATE_INCREASE (on F-RCCH) to signal that the packet was delivered and that mobile station may increase the maximum rate for the next packet transmission relative to the transmit rate of the current packet. The mobile station may increase the rate following certain rules known to both base station and the mobile station. The increase may be either deterministic or probabilistic. Those of skill in the art will recognize myriad rules for increasing a rate. The base station may send ACK_RC (on F-ACKCH) and RATE_DECREASE (on F-RCCH) to signal that the packet was delivered and that the mobile station should decrease the maximum rate for the next packet transmission relative to the transmit rate of the current packet. The mobile station may decrease the rate following certain rules known to both the base station and the mobile station. The decrease may be either deterministic or probabilistic. Those of skill in the art will recognize myriad rules for decreasing a rate. If a packet is not received successfully by the base station, and the packet may be further retransmitted (i.e., not the last subpacket), the base station sends a NAK on F-ACKCH. Note that F-RCCH is DTXed in this example. If further retransmission is not allowed for the packet (i.e., last subpacket), the following are possible actions the base station may take. The base station may send NAK (on F-ACKCH) and a grant message simultaneously on the F-GCH to signal the mobile station that the packet was not delivered and that the mobile station may transmit up to the granted rate for the next transmission. F-RCCH is DTXed in this case. In one embodiment, only a serving (or granting) base station may generate grants. In an alternate embodiment, one or more base stations may generate grants (details for handling this option are detailed below). The base station may also send a NAK (on F-ACKCH) and RATE_HOLD (on F-RCCH) to signal that the packet was not delivered and that the maximum rate the mobile station may transmit the next packet is the same as the transmit rate of the current packet. The base station may also send a NAK (on F-ACKCH) and RATE_INCREASE (on F-RCCH) to signal that the packet was not delivered and that the mobile station may increase the maximum rate for next packet transmission relative to the transmit rate of the current packet. The mobile station may increase the rate following certain rules known to both the base station and the mobile station. The increase can be either deterministic or probabilistic. The base station may also send a NAK (on F-ACKCH) and RATE_DECREASE (on F-RCCH) to signal that the packet was not delivered and that the mobile station should decrease the maximum rate for the next packet transmission relative to the transmit rate of the current packet. The mobile station may decrease the rate following certain rules known to both the base station and the mobile station. The decrease may be either deterministic or probabilistic. In an alternative embodiment (details not shown in FIG. 8), an alternative for NAK and stop may be created. For example, in the above scenario, a DTX on F-RCCH corresponding to a NAK cannot be distinguished from a “NAK-and-hold”. If it is desired to have a command to force a stop (or reversion to autonomous transmission), the base station could also use NAK and rate control, prior to the last subpacket, to indicate that a rate hold (or increase, or decrease) on the final subpacket is to mean stop. For example, any one of the rate control commands (i.e. RATE_INCREASE, RATE_DECREASE, or RATE_HOLD) may be assigned to mean stop in this special case. The mobile station will know when the last subpacket was transmitted, and can then parse the rate control commands accordingly. When the base station knows that if the final subpacket transmission should be followed by a stop in the event of a NAK, the selected rate control command may be issued with a NAK of a previous subpacket. A mobile station receiving the identified rate control command along with a NAK of a subpacket (not the final) would know that a NAK (and RATE_HOLD, for example) on the final subpacket would mean that any previous grant would be rescinded, and the mobile station must revert to autonomous transmission. The rate control commands not used for this purpose (i.e. RATE_INCREASE or RATE_DECREASE) transmitted with a final subpacket NAK would still be available. An alternative would be to transmit a grant with a zero (or lowered) rate along with the final NAK, although this would require additional overhead. Those of skill in the art will readily tradeoff these alternatives in accordance with the likelihood of “NAK-and-Stop” with other possibilities. The required overhead may then be optimized based on the probabilities of the various events. FIG. 9 depicts example method 900 for a mobile station to monitor and respond to grants, acknowledgements, and rate control commands. This method is suitable for deployment in one or more mobile stations for use in conjunction with one or more base stations employing method 700, as described above, as well as other base station embodiments. The process begins in block 910. The mobile station monitors the F-GCH, F-ACKCH, and F-RCCH. Note that in various embodiments, as described above, a mobile station may monitor one or more of these channels. For example, there may be multiple grant channels, and each mobile station may monitor one or more of them. Note also that each of these channels may be received from one base station, or more than one when the mobile station is in soft handoff. A channel may incorporate messages or commands directed to multiple mobile stations, and so a mobile station may extract the messages or commands specifically directed to it. Other rules may be employed to allow a mobile station to conditionally monitor one or more of the control channels. For example, as described above, the F-RCCH may not be transmitted when an ACK_STOP is issued. Thus, in such a case, the mobile station need not monitor the F-RCCH when an ACK_STOP is received. A rule may be specified that a mobile station looks for grant messages and/or rate control commands only if the mobile station has sent a request to which those messages may be responsive. In the following description of FIG. 9, it is assumed that the mobile station has previously transmitted a subpacket, for which an acknowledgement (including potential grants or rate control commands) response is expected. If a request has not been previously granted, the mobile station may still monitor for a grant in response to a previously transmitted request. Those of skill in the art will readily adapt method 900 to account for this situation. These, and other potential mobile station processing blocks, have been omitted for clarity of discussion. Beginning in decision block 915, the processing of the F-ACKCH begins. The mobile station extracts the information on all the F-ACKCH channels it monitors. Recall that there may be an F-ACKCH between the mobile station and every member of its F-ACKCH Active Set. Some of the F-ACKCH commands may be soft-combined, as specified via L3 signaling. If a mobile station receives at least one positive acknowledgement, either ACK_RC or ACK_STOP (on F-ACKCH), the current packet has been received correctly, and additional subpackets need not be transmitted. The allowable rate for transmission of the next packet, if any, needs to be determined. In decision block 915, if an ACK_STOP has been received, the mobile station knows that the previously transmitted subpacket has been received correctly, and that rate control commands need not be decoded. In decision block 920, the mobile station determines if a grant has been received on an F-GCH. If so, the mobile station transmits the next packet according to the grant, as indicated in block 930. In one embodiment, only one granting base station makes grants. If ACK_STOP and a grant message are received from the base station, the mobile station transmits a new packet on the same ARQ channel at any rate equal to or below the granted rate. In an alternate embodiment, more than one base station may send a grant. If the base stations coordinate the grant, and send an identical message, the mobile station may soft combine those grants. Various rules may be deployed to handle the cases when differing grants are received. One example is to have the mobile station transmit at the lowest rate indicated in a received grant, to avoid excessive interference in the cell corresponding to the respective granting base station (including an ACK_STOP without a corresponding grant—indicating that transmission should revert to autonomous mode). Various other alternatives will be apparent to those of skill in the art. If a grant was not received in decision block 920, the mobile station must return to autonomous rate, as shown in block 925. Then the process may stop. Returning to decision block 915, if an ACK_STOP is not received, proceed to decision block 940. If an ACK_RC is received, the mobile station monitors the corresponding F-RCCH of base stations from which positive acknowledgement(s) are received, if any. Note that there may not be an F-RCCH between a base station and the mobile station, as the F-RCCH Active Set is a subset of the F-ACKCH Active Set. Note again that when a mobile station receives an F-ACKCH from multiple base stations, the corresponding messages may be in conflict. For example, one or more ACK_STOP commands may be received, one or more ACK_RC commands may be received, one or more grants may be received, or any combination thereof. Those of skill in the art will recognize various rules for implementing to accommodate any of the possibilities. For example, the mobile station may determine the lowest possible transmission permission (which may be from either an ACK_STOP with no grant, an ACK_RC with a decrease, or a grant with a lower value) and transmit accordingly. This is similar to a technique known as an “OR-of-Downs” rule. Such a technique may be used to strictly avoid excessive interference with neighbor cells. Or, one or more base stations may have a priority assigned with them, such that one or more base station may have the ability to trump others (with conditions attached, perhaps). For example, a scheduling (or granting) base station may have some priority over other base stations in soft handoff. Other rules are also anticipated. (Recall that one or more NAKs may also be received, but the mobile station need not retransmit. However, a mobile station may incorporate rate control commands or grants, in similar fashion, from a NAKing base station, if desired.) To facilitate the discussion herein, when it is said that a mobile station determines whether an ACK_STOP, ACK_RC, NAK, or grant is received, it may be the result of applying a desired set of rules to a number of commands received, and the outcome is the command identified. If an ACK_RC has been received, proceed to decision block 945 to begin determining what type of rate control command should be followed. If an increase is indicated, proceed to block 950. The next transmission may be transmitted on the same ARQ channel at an increased rate from the current rate. Then the process may stop. Again, the increase may be deterministic or probabilistic. Also, a RATE_INCREASE may not necessarily result in immediate rate increase but would increase the transmission rate from the mobile station in the future (i.e., a credit-like algorithm is used at the mobile station), or a RATE_INCREASE may result in an increase spanning multiple rates. In an example credit algorithm, a mobile station maintains an internal “balance/credit” parameter. Whenever it receives RATE_INCREASE but can't increase its rate (because it is either running out of power or data), the mobile station increases the parameter. When power or data becomes available for the mobile station, it may use the stored “credit/balance” in selecting data rates. Various ways of increasing the rate will be apparent to those of skill in the art. If an increase is not indicated in decision block 945, proceed to decision block 955 to determine if a decrease is indicated. If a decrease is indicated, proceed to block 960. The next transmission may be transmitted on the same ARQ channel at a decreased rate from the current rate. Then the process may stop. Again, the decrease may be deterministic or probabilistic. Also, a RATE_DECREASE may not necessarily result in immediate rate decrease but would decrease the transmission rate from the mobile station in the future (i.e., a credit-like algorithm is used at the mobile station), or a RATE_DECREASE may result in a decrease spanning multiple rates. When an example credit algorithm is used in the RATE_DECREASE context, when a mobile station gets a RATE_DECREASE but doesn't follow it for some reason (e.g. urgent data that needs to be sent out), it gets a negative credit, and this negative credit needs to be paid back later on, in a sense. Various ways of decreasing the rate will be apparent to those of skill in the art. If neither an increase nor decrease is indicated, a RATE_HOLD has been received. The mobile station may transmit the next packet at a maximum rate equal to the rate of the current packet, as indicated in block 965. Then the process may stop. Returning to decision block 940, if neither type of ACK has been identified, a NAK will be determined to have been received. In decision block 970, if retransmission is still possible for the packet (i.e., the current subpacket was not the last subpacket), the mobile station retransmits the subpacket on the same ARQ channel with the subpacket ID incremented, as depicted in block 980. In decision block 970, if the current packet was the last subpacket, the mobile station has run out of retransmissions for the packet. Proceed to decision block 975 to determine if a grant has been received (in similar fashion as described above with respect to block 920). If a grant message is designated to the mobile station (whether from a single base station, or more than one, as discussed above), the mobile station may transmit a new packet on the same ARQ channel at a rate equal to or below the granted rate. Proceed to block 930, described above. In decision block 975, if a grant has not been received, the mobile station may monitor the F-RCCH Active Set, obtain rate control commands, and decide the maximum rate allowed for next packet transmission on the same ARQ channel. The selection of rates when more than one rate control command is received may be made as described above. Proceed to decision block 945 and continue as described above. Various other techniques may be employed by an exemplary embodiment of a mobile station. A mobile station may monitor the number of packet erasures (i.e., no positive acknowledgement after the last subpacket). A measurement may be made by counting the number of consecutive packet erasures or counting the number of erased packets within a window (i.e. a sliding window). If the mobile station recognizes too many packets have been erased, it may reduce its transmit rate even if the rate control commands indicate another command (i.e. RATE_HOLD or RATE_INCREASE). In one embodiment, a grant message may have higher priority than a rate control bit. Alternatively, a grant message may be treated with the same priority as a rate control bit. In such a case, rate determination may be modified. For example, if no grant message is designated to the mobile station, the rate for next transmission is determined from all rate control commands (RAT _INCREASE, RATE_HOLD, RATE_DECREASE, and ACK_STOP) using an “OR-of-DOWN” or similar rule. When a grant is also received, a rate for next transmission may determined from all rate control commands (RATE_INCREASE, RATE_HOLD, RATE_DECREASE, and ACK_STOP) using an “OR-of-DOWN” or similar rule, the result of which is compared with a granted rate and the smaller rate chosen. Signaling may be deployed to configure the mobile station so that the mobile station only monitors the F-RCCH indicator from either the serving base station or from all base stations in the F-RCCH Active Set. For example, when RATE_COMB_IND may specify that a rate control command is the same from multiple base stations, then the mobile station may combine all indicators in the identified group before making a decision. The number of distinctive indicators in use at any time may be indicated as the F-RCCH Current Set. In one example, a mobile station may be configured to monitor only the F-RCCH indicator from the Serving base station, in which case the size of the F-RCCH Current Set is 1. In addition, as described above, various rules may be deployed for adjusting rates in response to commands on the F-RCCH. Any of these rules may be adjusted by signaling from the base station. In one example, there may be a set of probabilities and step sizes used in determining whether the mobile station increases or decreases its rate, and by how much. These probabilities and possible rate step sizes may be updated through signaling, as necessary. Method 900 may be adapted to include the various alternatives described for a base station employing method 750, described above. For example, in one embodiment, a NAK and stop command is not explicitly defined, as a DTX on the F-RCCH along with a NAK indicates a rate hold. In an alternate embodiment, NAK and stop functionality may be deployed responding to any of the alternate techniques described above for method 750. Also, as noted above with respect to method 750, in the example embodiment, rate control or grant based change of rate is carried out on packet boundaries. It is anticipated that the methods described may be modified to incorporate inter-subpacket rate changes as well. It will clear to those of skill in the art in light of the teaching herein that any of the procedures and features described herein may be combined in various ways. For example, a mobile station may only be controlled by the primary base station via grants but not controlled by other base stations via rate control bits. Alternatively, the mobile station may be controlled via grants from all the base stations, or a subset of base stations in its Active Set. Some F-GCHs may be soft combined. The mode in which a mobile station operates may be set up via L3 signaling during channel assignment or via other messages during a packet data call. As another example, if a packet is received correctly, the primary base station may send either ACK_STOP or ACK_RC. The rate control commands may not be used, thus ACK_RC may be used to mean “ACK and continue” for this mode. In this context “ACK and continue” indicates that the mobile station may transmit a new packet at the same rate as the packet that is being acknowledged. As before, if ACK_STOP is sent, the base station may also send an overriding grant on F-GCH designated to the MS. In this example, a NAK will indicate “NAK and stop”, unless a corresponding grant is transmitted with the NAK. In this scenario, non-primary base stations also send ACK_STOP or ACK_RC, where ACK_RC is not accompanied by a rate control command, and indicates “ACK and continue”. In another example special mode, incorporating a subset of the features described, the mobile station may be controlled via rate control bits only (from base stations in its F-RCCH Active Set). This mode may be set up via L3 signaling during channel assignment or other messages during a packet data call. In this mode, a base station sends NAK if a packet is not received successfully. When a packet is received correctly, a base station sends either ACK_STOP or ACK_RC along with the F-RCCH (RATE_HOLD, RATE_INCREASE, or RATE_DECREASE). A NAK after the last subpacket may be accompanied with the F-RCCH (RATE_HOLD, RATE_INCREASE, or RATE_DECREASE). FIGS. 10-12 show examples illustrating timing of various channels described herein. The examples do not represent any specific choice of frame length, but illustrate relative timing of the grant, ACK, and rate control (RC) indicators. The ACK indicator, RC indicator, and the grant occur during the same time interval such that the mobile station receives the ACK, RC and grant information at roughly the same time for application to the next packet transmission. In these examples, the mobile station need not monitor the RC indicators except when it receives an acknowledgement or when all subpackets have been transmitted (as described in example embodiments above). A mobile station monitors the ACK bit assigned to it and to the RC indicator corresponding to the particular ARQ sequence. For example, if there are four ARQ sequences, and the mobile station is transmitting on all ARQ sequences, then the mobile station monitors the ACK indicator every frame and to the RC indicator (as applicable) every frame. Empty frames between various transmissions are introduced to allow time for a base station or mobile station, as applicable, to receive and decode requests, subpacket transmissions, grants, acknowledgements, and rate control commands. Note that these timing diagrams are not exhaustive, but serve only to illustrate various aspects described above. Those of skill in the art will recognize myriad combinations of sequences. FIG. 10 depicts timing for an example embodiment with combined acknowledgement and rate control channels. A mobile station transmits a request for transmission on the R-REQCH. A base station subsequently transmits a grant on the F-GCH in response to the request. The mobile station then transmits a first subpacket using parameters in accordance with the grant. The subpacket is not decoded correctly at a base station, as indicated by the strikeout of the subpacket transmission. The base station transmits an ACK/NAK transmission on the F-ACKCH along with a rate control command on the F-RCCH. In this example, a NAK is transmitted, and the F-RCCH is DTXed. The mobile station receives the NAK and retransmits the second subpacket in response. This time, the base station correctly decodes the second subpacket, and again sends an ACK/NAK transmission on the F-ACKCH along with a rate control command on the F-RCCH. In this example, no additional grant is transmitted. An ACK_RC is transmitted, and a rate control command is issued (it may indicate an increase, decrease, or hold, as determined according to the desired scheduling). The mobile station then transmits the first subpacket of the next packet, using parameters associated with the grant, modified as necessary by the rate control command on the F-RCCH. FIG. 11 depicts timing for an example embodiment with combined acknowledgement and rate control channels, along with a new grant. A request, grant, subpacket transmission (not decoded correctly) and NAK are transmitted the same as the first eight frames described above with respect to FIG. 10. In this example, the second subpacket transmission is also received and decoded correctly. However, instead of an ACK_RC being sent by the base station, an ACK_STOP is transmitted. If no grant accompanied the ACK_STOP, the mobile station would revert to autonomous transmission. Instead, a new grant is transmitted. The mobile station needn't monitor the F-RCCH for this frame. The mobile station then transmits the first subpacket of the next packet in accordance with the new grant. FIG. 12 depicts timing for an example embodiment with combined acknowledgement and rate control channels, without a grant. This example is identical to FIG. 10, except that no grant is sent in response to the original mobile station request. Thus, the first subpacket transmission of the first packet is transmitted at the autonomous rate. Again, this subpacket is decoded incorrectly at the base station. The second subpacket is again decoded correctly, and an ACK_RC is transmitted along with a rate control command. The mobile station then sends the next packet at the potentially adjusted rate. This example illustrates the possibility of moving a mobile station rate arbitrarily using rate control commands only, without any grant. Note that in an alternative embodiment, a base station may use rate control with autonomous transmissions with or without a previous request. Reductions may be used to relieve congestion, and an increase may be awarded when there is extra capacity, even though the BS may not know the data requirements, since a request was not transmitted. FIG. 13 depicts an example embodiment of a system 100 comprising a dedicated rate control signal and a common rate control signal. A dedicated rate control channel (F-DRCCH) is transmitted from a base station 104 to a mobile station 106. The F-DRCCH functions along with the forward acknowledgement channel (F-ACKCH) to provide acknowledgement, continue grants, and perform rate control, in substantially the same manner as the F-ACKCH and F-RCCH, described above. A base station may send a dedicated rate control channel to each of a plurality of mobile stations. In this embodiment, the base station also transmits a common rate control channel (F-CRCCH). The common rate control channel may be used to control the rate of a group of mobile stations simultaneously. FIG. 14 depicts an embodiment of a system 100 comprising a forward extended acknowledgment channel (F-EACKCH). The F-EACKCH may take the place of both an acknowledgment channel (i.e. the F-ACKCH described above) and a rate control channel (i.e. the F-RCCH). The functions of both channels may be combined into one channel in a manner consistent with various aspects of the invention. The F-EACKCH is transmitted from one or more base stations 104 to one or more mobile stations 106. The F-CRCCH may be transmitted along with the F-EACKCH, as described above, and detailed further below. The concepts of common rate control and extended acknowledgement channel are distinct, however, so the two need not be combined (hence the dashed line for F-CRCCH, shown in FIG. 14). For example, the F-ACKCH may comprise commands according to a two-bit data pattern (having four states). ACK-and-continue information may be combined with a command for data rate increase as the first state. ACK-and-continue information may be combined with a command for data rate decrease as the second state. ACK-and-stop may be the third state, and NAK as the fourth state. The four states may be represented with an I and Q modulation format constellation in accordance with commonly know techniques. FIG. 15 depicts an example constellation suitable for deployment on the F-EACKCH. As known in the art, such a constellation may be deployed using Quadrature Amplitude Modulation (QAM) techniques. In alternative embodiment, any two signals may be deployed to map commands in two dimensions, as shown. In this example, seven points are assigned to various commands. The null transmission (0,0) point is assigned to NAK_HOLD. This may be the most likely transmitted command, and therefore transmission power and capacity may be preserved by such an assignment. The various other commands, assigned to points on the circle, as shown, include ACK_INCREASE, ACK_HOLD, ACK_DECREASE, NAK_DECREASE, NAK_INCREASE, and ACK_STOP. Each of these commands may be sent as a single QAM modulation symbol. Each command corresponds to a pair of commands sent on an analogous set of F-ACKCH and F-RCCH channels. An ACK_INCREASE indicates that a previous subpacket was decoded correctly, and future subpackets may be sent at an increased rate. An ACK_HOLD indicates that a previous subpacket was decoded correctly, and a future subpacket may be transmitted at the present rate. An ACK_DECREASE indicates that a previous subpacket was decoded correctly, and that a future subpacket may be transmitted, albeit at a reduced rate. An ACK_STOP indicates that a previous subpacket was decoded correctly, but any previous grants and/or rate control commands are rescinded. The mobile station is relegated to autonomous transmission (if applicable) only. A NAK_INCREASE indicates that a subpacket was not decoded correctly. Future transmissions may be sent at a higher rate (perhaps due to capacity constraints easing, for example). In one embodiment, rate control commands are sent after the final subpacket transmission. An alternative embodiment may allow for rate control transmissions with NAKs at any time. In similar fashion, a NAK_DECREASE indicates that the previous subpacket did not decode correctly, and future transmissions must be made at a reduced rate. A NAK_HOLD indicates that a previous subpacket was not decoded correctly, and future transmission may be made at the present rate. A NAK_STOP command is not deployed in the example of FIG. 15, although those of skill in the art will recognize that such a command (or other commands) could be introduced. Various alternatives for encoding NAK_STOP (detailed above) may also be used with an F-EACKCH, as well. Those of skill in the art will recognize myriad constellations may be deployed incorporating any set of commands (or combinations thereof), as detailed herein. Constellations may be designed to provide various protection levels (i.e. probability of correct reception) to various commands, sets of commands, or command types. FIG. 16 depicts an alternate constellation suitable for deployment on an F-EACKCH. This example illustrates the removal of rate control for NAK commands. The various ACK commands include ACK_HOLD, ACK_INCREASE, ACK_DECREASE, and ACK_STOP. The null command (0,0) is assigned to NAK, for reasons described above. In addition, it can be seen that the distance between a NAK and any ACK command is equal, and can be set to any value to provide the probability of error for the NAK desired. Various constellations may be designed to group sets of commands with properties desired. For example, NAK commands may be allocated points relatively close together, ACK commands may be allocated points relatively close together, and the two groups may be separated by a relatively larger distance. In that way, although the probability of mistaking one type of command in a group with another in the group may increase, the probability of mistaking the group type is reduced in relation. So, an ACK is less likely to be misidentified as a NAK, and vice versa. If decrease, increase, or hold is misidentified, then a subsequent rate control command may be used to compensate. (Note that an indication of an increase when a decrease or hold was sent, for example, may increase the interference to other channels in the system). FIG. 17 depicts a three-dimensional example constellation suitable for deployment on an F-EACKCH. A three-dimensional constellation may be formed by using any three signals to indicate the magnitude of each axis. Or, a single signal may be time multiplexed to carry the information for one or more dimensions in a first time period, followed by information for one or more additional dimensions in one or more second dimensions. Those of skill in the art will recognize that this may be expanded to any number of dimensions. In one example, a QAM signal and a BPSK signal may be transmitted simultaneously. The QAM signal may carry the x and y axis information, while the BPSK signal carries the z axis information. Constellation generation techniques are well known in the art. The example of FIG. 17 further illustrates the concept of grouping ACK commands away from NAK commands. Note that the relative distance between the ACK_STOP, ACK_DECREASE, ACK_HOLD, and ACK_INCREASE is smaller than the distance between any ACK command and any NAK command (which include NAK_HOLD, NAK_INCREASE, and NAK_DECREASE, in this example). Thus, a mobile station is less likely to misinterpret an acknowledgement command than a rate command. Those of skill in the art will apply the teachings herein to form constellations comprising any set of commands, with protection set equally for the commands, or with protection distributed in any fashion desired. FIG. 18 depicts an embodiment of method 750, for processing received transmissions at a base station, including acknowledgement and rate control, suitable for deployment as step 750, described above. Recall that, prior to step 750, a base station has received previous requests, if any, made any grants desired, received both granted and autonomous transmissions, and performed scheduling incorporating these and other factors. This embodiment of step 750 begins in block 1810. The base station makes any grants required, as applicable, in accordance with the previously performed scheduling. In block 1820, an ACK or NAK command is generated to acknowledge previous transmissions. The acknowledgement command may be combined with or accompanied by a command to extend a previous grant, or a command to rate control existing grants (including rate control of autonomous transmissions). Any of the techniques described herein may be deployed for the signaling of block 1820, including separate rate control and acknowledgement signals as well as a combined acknowledgement rate control signal. In block 1830, an ACK_STOP command may be sent to indicate that a mobile station should revert from a previous grant to autonomous mode. In this example, an ACK_STOP is also used to direct the mobile station to switch from monitoring a dedicated rate control channel (i.e. an F-DRCCH) and to monitor a common rate control signal (i.e. F-CRCCH) instead. In an alternate embodiment, other commands may be selected to indicate a shift from dedicated to common rate control channel monitoring. A specific command for this purpose may be defined. The specific command may be incorporated in a combined channel as well, with one or more points on a constellation, or it may be sent via signaling. In block 1840, one or more base stations provide acknowledgement for subsequent autonomous transmissions. In block 1850, common rate control is then used to modify the rates of one or more mobile stations monitoring the common rate control channel. Then the process may stop. FIG. 19 depicts an embodiment of method 1900 for responding to common and dedicated rate control. Method 1900 may be deployed in a mobile station responsive to a base station deploying a combination of common and dedicated rate control, such as described above with respect to FIGS. 7 and 18. The process begins in decision block 1910. In this example, dedicated rate control is provided along with a grant. A mobile station not operating under a grant will monitor the common rate control channel. In alternative embodiments, mobile stations operating under a grant may also be directed to follow the common rate control signal, or non-granted mobile stations may be assigned a dedicated rate control channel. These alternates are not depicted in FIG. 19, but those of skill in the art will readily deploy such embodiments, and modifications thereof, using any of various signaling techniques, in light of the teaching herein. In decision block 1910, if the mobile station is operating under a previous grant, proceed to block 1940. In block 1940, the mobile station monitors the grant channel (i.e. the F-GCH), acknowledgment, and rate control channels (which may be the F-ACKCH and F-DRCCH, or a combined F-EACKCH, as described above). In block 1945, if an ACK_STOP command is received, proceed to block 1950. In this embodiment, an ACK_STOP is used to designate a reversion to autonomous transmission, as shown in block 1950. As will be detailed further below, an ACK_STOP also indicates a transition from monitoring the dedicated rate control channel to monitoring the common rate control channel. In alternate embodiments, a command other than ACK_STOP may be used to indicate a switch from dedicated to common rate control channel monitoring, and the command need not be identical to the command for reverting to autonomous transmission. After block 1950, the process may stop. In an example embodiment, method 1900 will be iterated repeatedly, as necessary. In decision block 1945, if an ACK_STOP is not received, proceed to block 1955. In block 1955, the mobile station may transmit according to the ACK/NAK, rate control, and/or grant channel commands that may be received. Then the process for the current iteration may stop. Returning to decision block 1910, if the mobile station is not currently operating under a previous grant, proceed to decision block 1915. In decision block 1915, if a grant is received on a grant channel, proceed to block 1920 and transmit according to the received grant, after which the process may stop. Note that, in this example, as described above, a grant is used to indicate that a mobile station is to monitor a dedicated rate control channel. Thus, in a subsequent iteration of method 1900, this mobile station would proceed from decision block 1910 to block 1940, as described above. In alternate embodiments, alternate techniques for signaling a switch to dedicated rate control monitoring may be deployed. In decision block 1915, if grant is not received, the mobile station monitors the common rate control channel, as shown in decision block 1925. If a common rate control command is issued, proceed to block 1930. The mobile station adjusts the rate in accordance with the common rate control command and may continue to transmit autonomously at the revised rate. Then the process may stop. If, in decision block 1925, a common rate control command is not received, proceed to block 1935. The mobile station may continue to transmit autonomously at the current rate. Then the process may stop. FIG. 20 depicts an alternate embodiment of method 750, for processing received transmissions, including acknowledgement and rate control, suitable for deployment as step 750, described above. This embodiment illustrates the used of the extended acknowledgement channel (F-EACKCH) to combine acknowledgment and rate control. Recall that, prior to step 750, a base station has received previous requests, if any, made any grants desired, received both granted and autonomous transmissions, and performed scheduling incorporating these and other factors. This embodiment of step 750 begins in block 2005. The base station makes any grants required, as applicable, in accordance with the previously performed scheduling, depicted in block 2010. In decision block 2015, an ACK or NAK is determined in response to the previously received transmission. The ACK or NAK will be combined with rate control to provide a combined F-EACKCH, detailed below. If an ACK is to be sent, proceed to decision block 2020. If rate control, including holding the current rate (i.e. ACK-and-continue) is desired for the target mobile station (as determined in any scheduling performed in prior steps), proceed to decision block 2030. In decision block 2030, if an increase is desired, proceed to block 2035 and send an ACK_INCREASE on the F-EACKCH. Then the process may stop. If an increase is not desired, determined if a decrease is desired in decision block 2040. If so, proceed to block 2045 to transmit an ACK_DECREASE on the F-EACKCH. Then the process may stop. If neither an increase nor decrease is desired, a hold is in order. Proceed to block 2050 to transmit an ACK_HOLD on the F-EACKCH. Then the process may stop. Note that each of these three ACK commands, with rate control, are used to extend the previous grant as well. In decision block 2020, if rate control is not desired, transmit an ACK_STOP on the F-EACKCH, as shown in block 2025. Then the process may stop. When used in conjunction with an embodiment such as depicted in FIGS. 18-19, for example, in which common and dedicated rate control are deployed, an ACK_STOP is one example of a command that can indicate a mobile station to transition from dedicated to common rate control monitoring. In this example, an ACK_STOP terminates any previous grant, and the mobile station will then be relegated to autonomous transmission. Returning to decision block 2015, if an ACK is not to be transmitted, then a NAK is in order. As described above, there are various alternatives for combining rate control with a NAK, depending on whether the NAK is in response to the final subpacket or not. In alternative embodiments, those alternatives may also be incorporated in the method depicted in FIG. 20. In this example, if, in decision block 2055, the NAK is not in response to the final subpacket, proceed to block 2060, to transmit a NAK_HOLD on the F-EACKCH. This command, as described above, indicates that the subpacket was not decoded correctly, and the next subpacket may be transmitted at the current rate. Then the process may stop. In decision block 2055, if the NAK is in response to the final subpacket, proceed to decision block 2065. If no rate control is desired, proceed to block 2060 to transmit the NAK_HOLD on the F-EACKCH, as described above. Note that, in an alternate embodiment, additional commands may also be incorporated. For example, a NAK_STOP may be deployed for sending a NAK to a subpacket, while rescinding a previous grant. Those of skill in the art will recognize myriad other combinations in light of the teaching herein. In decision block 2065, if rate control is desired, proceed to decision block 2070. If an increase is desired, proceed to block 2075 to transmit a NAK_INCREASE on the F-EACKCH. Otherwise, proceed to block 2085 to transmit a NAK_DECREASE on the F-EACKCH. Then the process may stop. Note that, in this example, the default NAK, a NAK_HOLD, as shown in block 2060, is reachable from decision block 2065. If an alternate embodiment, i.e. including a NAK_STOP, is deployed, an additional decision path, analogous to blocks 2040-2050, described above, may be deployed to incorporate an alternate path to transmit a NAK_HOLD. FIG. 21 depicts method 2100 for receiving and responding to an F-EACKCH. In one embodiment, method 2100 may be deployed in a mobile station responsive to a base station transmitting according to various methods described above, including those depicted in FIGS. 7, 18, and 20. The method begins in block 2110, in which the mobile station monitors the grant channel (i.e. F-GCH) to determine if a grant has been received. In block 2120, the mobile station also monitors the F-EACKCH in response to a previously transmitted subpacket. The mobile station then transmits or retransmits according to the ACK or NAK indication on the F-EACKCH. The rate of transmission is also modified in accordance with any STOP, HOLD, INCREASE, or DECREASE on the F-EACKCH, as well as any received grants. Then the process may stop. Various alternative embodiments including common and dedicated rate control are described further below. A mobile station in soft handoff may monitor a common rate control from all cells in the active set, from a subset thereof, or from the serving cell only. In one example embodiment, each mobile station may increase its data rate only if all the F-CRCCH channels from the set of monitored cells indicate an allowed increase in data rate. This may allow for improved interference management. As indicated with this example, the data rate of various mobile stations in soft handoff may be different, due to differences in their active set sizes. The F-CRCCH may be deployed to accommodate more processing gain than the F-DRCCH. Thus, for the same transmit power, it may be inherently more reliable. Recall that rate control can be configured as common rate control (i.e., single indicator per sector), dedicated rate control (dedicated to a single mobile station), or group rate control (one or more mobile stations in one or more groups). Depending which mode of rate control is selected (which may be indicated to a mobile station via L3 signaling), a mobile station may have different rules for rate adjustment based on rate control bits, i.e., in particular, RATE_INCREASE and RATE_DECREASE. For example, the rate adjustment can be probabilistic if it is common rate control, and deterministic if it is dedicated rate control. Various other permutations will be apparent in light of the teaching herein. Also, in various examples described above, it has been assumed that rate control is per HARQ channel. That is, the mobile station only pays attention to rate control commands when it receives positive acknowledgement or negative acknowledgement after the last subpacket, and determines the rate adjustment for next transmission on the same ARQ channel. It may not pay attention to rate control commands during the middle of a retransmission. Accordingly, the base station doesn't send rate control commands in a middle of retransmission. For common rate control or group rate control, alternatives to the above rule are envisioned. In particular, the base station may send rate control commands during the middle of a retransmission. Accordingly, the mobile station may accumulate rate control commands during the middle of retransmission and apply them for the next packet transmission. In this example, we assume rate control is still per HARQ channel. However, F-ACKCH and F-RCCH function as two channels with independent operation. These techniques can also be generalized to rate control across all ARQ channels (or subsets thereof). Grant, Acknowledgment, and Rate Control Active Sets FIG. 22 depicts an example embodiment of system 2200. System 2200 is suitable for deployment as system 100 depicted in FIG. 1. One or more base stations 104A-104Z communicate with Base Station Controller (BSC) 2210. Well known in the art, the base station-to-BSC connections may be wired or wireless, using any of a variety of protocols. One or more mobile stations 106A-106N are deployed and may travel within and through the coverage area of the BSC 2210 and its connected base stations 104. The mobile stations 106 communicate with the base stations using one or more communication formats, examples of which are defined in the standards described previously. For example, mobile station 106A is shown communicating wirelessly with base station 104A and 104M, and mobile station 106N is shown communicating with base stations 104M and 104Z. BSC 2210 includes active sets 2220A-2220N, one for each mobile station with which the BSC is communicating. Various handoff and registration schemes are well known in the art for determining which mobile stations are within the coverage area of system 2200 at any given time. Each mobile station 106 has an active set 2230 corresponding to one of the active sets 2220 in the BSC. The active sets 2220 are the same in BSC 2210 as the active sets 2230 in corresponding mobile stations 106. In an example embodiment, once the BSC decides to change an active set, it signals the change to the mobile station with a corresponding action time. At the designated action time, both the BSC and mobile station update their active sets. Thus, the two active sets remain synchronized. In an alternate embodiment, if such a synchronization technique were not deployed, the two may be out of synch until signaling or some other mechanism communicates the active set updates. An active set 2220 or 2230 may be stored in memory using any of various techniques, well known in the art. In current systems, and an example embodiment, the BSC determines the active set for each mobile station. In general, in alternate embodiments, a mobile station or a BSC may determine the active set, in whole or in part. In such case, changes in one may be signaled to the other, in order to keep the active sets synchronized. In a traditional CDMA cellular system, a mobile station's active set is generated as follows. The mobile station reports the signal strength of neighboring base stations through one or more base stations to the base station controller. In an example embodiment, this is reporting is accomplished with a Pilot Strength Measurement Message (PSMM). The BSC may then determine the mobile station's active set using the reported pilot signal strengths, among other criteria. The active set may be signaled via one or more base stations to the mobile station. In an example embodiment, such as a 1xEV-DV system, the mobile station may autonomously select its serving cell by transmitting its channel quality indicator (CQI) using a covering sequence that is unique to the serving cell. To switch cells, a mobile station simply changes the covering sequence. Various other methods for autonomously selecting a base station will be apparent to those of skill in the art. Examples include sending a message to the previously selected base station, the newly selected base station, or both. In an alternate embodiment, an active set in a 1XEV-DV style system, where a mobile station selects base stations autonomously, for example, may be created at the mobile station by storing recently selected base stations as well as other monitored base stations that meet certain criteria. The mobile station may also signal its created active set to the base station controller to aid in selection of additional active sets, such as grant, acknowledgement, and rate control active sets, described below. The mobile station may combine signals from multiple base stations in an active set, when desired. For example, the FCH (Fundamental Channel) or DCCH (Dedicated Control Channel), example signals in various standards listed previously, may be transmitted from an active set including multiple base stations and combined at the mobile station. In these examples, the active set associated with the example signals is generally decided by the BSC or some other central processing location. In the example 1xEV-DV embodiment, however, the F-PDCH is generally sent from a single base station, as described above. Thus, the mobile station does not have multiple F-PDCH signals to combine. Reverse link signals may be combined in one or more base stations. Sector combining is particularly suitable, in which multiple sectors of a single base station (or other co-located sectors) may be combined. With a suitably high bandwidth backhaul, it is conceivable that disparate base stations may also combine received signals. In example cellular systems deployed today, selection combining is typically deployed, in which each separately located base station decodes the received transmission (possibly softer-combining sectors), and responds based on whether the separate decoding is successful. If so, the received transmission may be forwarded to the BSC (or other destination of the received packet), and an acknowledgement may be transmitted to the mobile station. If any receiver decodes the packet correctly, the transmission is deemed successful. The principles disclosed herein may be deployed with any type of forward or reverse link combining strategies. In FIG. 23, an extended active set, suitable for deployment as active set 2220 or 2230, is graphically depicted. Various active sets are shown as ellipses to illustrate the base stations included in the active sets. Overlapped or circumscribed ellipses denote common inclusion of base stations in more than one type of active set (i.e., they may be seen as Venn diagrams). The example extended active set 2230 or 2230 shown in FIG. 23 includes an FCH type active set 2310 (alternate examples include a mobile station generated active set as described for the 1xEV-DV F-PDCH channel, described above). Active set 2310 may be used for the functionality of the traditional active set, that is, for receiving and combining forward or reverse link signals at a mobile station or group of base stations (and/or sectors), respectively. In the discussion herein, the group of active sets, detailed further below, included in the extended active set 2220 or 2230 may also be deployed as independent active sets, as will be apparent to those of skill in the art. Acknowledgement active set 2320 identifies the base stations from which a forward acknowledgement channel will be transmitted. Base stations within the acknowledgement active set 2320 may transmit acknowledgement commands, examples of which are detailed above, to the mobile station associated with the active set. A base station in an acknowledgment active set may not be required to transmit an acknowledgment command at all times. The associated mobile station may monitor the acknowledgment channels from those base stations in the acknowledgment active set. In an example embodiment, the mobile station need not monitor acknowledgement channels from base stations outside the acknowledgement active set, thus potentially minimizing complexity and/or power consumption in the mobile station. By efficiently maintaining the acknowledgment active set, signaling or other techniques for identifying the required acknowledgement channels may be reduced, thus increasing the effective use of shared resources. For examples of potential efficiency gains, consider an alternative ad-hoc signaling method for determining which base stations transmit certain signals to a mobile station. The ad-hoc signaling may require extra power or resource allocation. Another benefit may be ease and efficient allocation of Walsh channels for transmitting the varied signaling. Those of skill in the art will recognize that in many instances, Walsh tree utilization may be a factor in determining capacity. In the example of FIG. 23, the acknowledgment active set is shown as a subset of active set 2310, although this is not a requirement. The two sets may be identical, and, depending on how active set 2310 is defined, the acknowledgment active set 2320 may be a superset of active set 2310. Grant active set 2340 is shown as a subset of acknowledgement active set 2320. Again, this is one example only. The grant active set may be used to indicate which base stations may transmit a grant to an associated mobile station. Thus, the associated mobile station may use the grant active set to identify the grant channels from which a grant may come, and thus may limit its monitoring to those channels, potentially minimizing complexity and/or power consumption in the mobile station. By efficiently maintaining the acknowledgment active set, signaling or other techniques for identifying the required grant channels may be reduced, thus increasing the effective use of shared resources. Overhead from signaling may be reduced by adopting a grant active set 2340. As an example of a potential additional efficiency gain, consider an alternative in which the number of base stations authorized to make a grant are not restricted. A base station with a relatively weak connection with a mobile station may not have an accurate picture of the channel environment closer to the mobile station. A grant from such a base station may create system performance issues for the base stations (and their respective connected mobile stations) if a grant is made in this situation. In addition, sending grant for a weak forward link may be costly. The grant channel active set may be altered with a mobile station autonomously. As described above, the mobile station may autonomously change serving cells by switching the covering sequence of its CQI. When a mobile autonomously switches its serving base station, there are other alternatives for updating the grant active set. In the case where the grant channel active set size is set to one, the mobile station may update the grant channel active set as it effects a change in the serving cell, assuming the single granting base station is the serving cell. Another option, not limited to the grant active set size, is to set the grant active set to a null set, and the mobile station waits for messages to include one or more new base stations in the grant active set. Or, each base station may have a pre-defined or signaled list of other granting base stations to be used when the corresponding base station is selected. Various other alternatives may also be deployed. A base station, upon learning of a new mobile station in its coverage area (i.e. receiving a new series of CQI messages) may signal to the BSC that the mobile station has autonomously reselected, thus the BSC may update its copy of the mobile station active set accordingly. The mobile station may also send a message to the BSC through one or more base stations as well. Generally speaking, the notion of a serving base station may be disconnected from the notion of the granting active set (although it may common for the granting active set to include the serving base station). For example, signaling may be used to direct the mobile station to monitor the grant channel from each of specific lists of base stations, while the mobile station may autonomously select its serving base station (i.e., the base station sending the F-PDCH) at will. Rate control active set 2350 is also shown as a subset of acknowledgement active set 2320. It is shown intersecting with grant active set 2340. Again, this is one example only. Various alternative embodiments are detailed below. The rate control active set may be used to indicate which base stations may transmit a rate control command or channel to an associated mobile station. Thus, the associated mobile station may use the rate control active set to identify the rate control channels from which a grant may come, and thus may limit its monitoring to those channels, potentially minimizing complexity and/or power consumption in the mobile station. By efficiently maintaining the acknowledgment active set, signaling or other techniques for identifying the required rate control channels may be reduced, thus increasing the effective use of shared resources. Note that combined acknowledgement/rate control channels, detailed above, may also be deployed in combination with the active sets described herein. Those of skill in the art will readily adapt the various embodiments detailed above in light of the teaching herein. In FIG. 23, rate control active set 2350 is shown as a subset of acknowledgement active set 2320, and intersecting with grant active set 2340. Again, this is one example only. As an illustration, it may be desirable for any base station capable of receiving and potentially decoding a reverse link transmission to attempt to decode and transmit the appropriate acknowledgment command in response. However, the channel between the mobile station and one or more of these base stations may be sufficiently weak that those base stations need not be involved in granting or rate controlling the mobile station. Thus, a relatively larger acknowledgment active set 2320 may be in order. Other base stations, within the larger acknowledgment active set 2320, may be situated such that they are strong enough to perform rate control, but a grant may not be desirable (for example, the weaker base station may not fully understand the effects of a grant to the stronger base stations, in relation to the mobile station). Other factors may also come into play. For example, a grant may be expensive in terms of forward link overhead. A relatively weaker base station may still perform rate control without using an undue amount of power that may be required to satisfactorily transmit a grant. Rate control generally requires fewer bits than a grant, examples of which are detailed above. Furthermore, a rate control loop may be more tolerant of errors, since incremental rate adjustments are made, and the loop can self correct. A grant, depending on its magnitude, and the magnitude of change introduced by an error, may result in a large rate change in the mobile. System capacity may be more harshly degraded in such a situation. Thus, in situations such as these, it may be desirable to deploy a rate control active set 2350 that is separate from or partially overlaps grant active set 2340. Those of skill in the art will readily adapt various techniques for allocating base stations to various active sets in light of the teaching herein. FIG. 24 depicts an example alternate extended active set 2220 or 2230. In this example, the rate control active set 2350 is a superset of grant active set 2340. As such, every base station in the grant active set may also use rate control, if desired. Some of the base stations in the rate control active set 2350 are not authorized to transmit a grant. One reason for the contrast of intersecting grant and rate control active sets may be that some base stations may not be equipped for scheduling, or may not be equipped for rate control. Other reasons for limiting a base station to scheduling solely with grants without rate control may be found. For example, in some instances, the nature of the data being transmitted may lend itself to rapid changes, more suitable to a grant method. Alternatively, some data may lend itself better to a rate control method. Nonetheless, the example of FIG. 24 illustrates a grant active set 2340 that is a subset of rate control active set 2350. Those of skill in the art will recognize myriad configurations of active sets in light of the teaching herein. FIG. 25 depicts yet another example alternate extended active set 2220 or 2230. In this example, there is no rate control active set 2350. Alternately, a rate control active set 2350 may be deployed, but it is empty. In this case, resource allocation, at least for the associated mobile station, is via grant scheduling only. There is no rate control. A variety of factors may lead to such a deployment, such as the nature of the data, or the lack of support for rate control in a network or mobile station. In this example, the acknowledgment active set 2320 is a superset of the grant active set 2340. FIG. 26 depicts yet another example alternate extended active set 2220 or 2230. In this example, there is no grant active set 2340. Alternately, a grant active set 2340 may be deployed, but it is empty. In this case, resource allocation, at least for the associated mobile station, is via rate control only. There is no grant scheduling. A variety of factors may lead to such a deployment, such as the nature of the data, or the lack of support for grant scheduling in a network or mobile station. In this example, the acknowledgment active set 2320 is a superset of the rate control active set 2350. Note that the size and configuration of the active sets may be continually updated as desired, to effect varying implementations of scheduled or rate controlled resource allocation. The active sets may be updated in response to the nature of the date being transmitted. For example, as discussed previously, grant scheduling may be desired when a fast ramp-up or ramp-down of data rate is needed (i.e. bursty, relatively large quantities of data, or particularly time-sensitive data). Or, for steady data flow, rate control may provide the needed control with lower overhead. By restricting the various allocation methods to the base stations within the respective active sets, reverse link transmission may be controlled efficiently, as detailed herein, without undue interference in neighboring cells. Meanwhile, flexibility is retained to support various QoS levels, etc. In neighboring systems, one vendor may employ a different functionality set than another. For example, one vendor may not support grant scheduling. Or, one vendor may not support rate control. The deployed features of the various base stations may be incorporated by including them in the respective active sets. Active sets may include any number of base stations, including zero. Another alternate, not shown, is an extended active set 2220 or 2230 including an acknowledgement active set 2320 and no grant or rate control active sets (or, in the alternative, empty grant and rate control active sets). In this case, a mobile station is effectively relegated to autonomous transmission only. The mobile station may preserve resources and reduce overhead by suppressing any desired request for transmission when the grant active set is empty. Any combination of grant, acknowledgement, and rate control active sets may be deployed within the scope of the present invention. FIG. 27 depicts example method 2700 for generation of an extended active set, such as active set 2220 or 2230. In this example, method 2700 may be performed in a BSC 2210, although those of skill in the art will recognize that method 2700, or portions thereof, may be adapted for deployment in a mobile station 106 or base station 104 as well. The process begins in block 2705, where a pilot signal strength measurement message (i.e. a PSMM) for a base station is received from a mobile station. Note that, in alternate embodiments, other base station measurements, or other information relevant to extended active set selection may be received at the BSC. In decision block 2710, if the information received indicates that the base station meets the criteria for selection in the grant active set, proceed to block 2715. Otherwise, proceed to decision block 2725. Various criteria, including signal strength, may be used in making the determination. Examples of other factors that may be included are described above. In block 2715, the base station has met the criteria, so the base station is added to the grant active set for the corresponding mobile station. In block 2720, a message or signal is sent to the mobile station indicating that it should add the base station to its grant active set. Note that if the base station is already in the grant active set, blocks 2715 and 2720 may be omitted (details not shown). If, in decision block 2725, the base station is currently in the grant active set, proceed to block 2730 to remove it since it no longer meets the criteria. In block 2735, the mobile station is sent a message or signal indicating the corresponding base station should be removed from the grant active set. In decision block 2740, if the information received indicates that the base station meets the criteria for selection in the rate control active set, proceed to block 2745. Otherwise, proceed to decision block 2755. Various criteria, including signal strength, may be used in making the determination. Examples of other factors that may be included are described above. In block 2745, the base station has met the criteria, so the base station is added to the rate control active set for the corresponding mobile station. In block 2750, a message or signal is sent to the mobile station indicating that it should add the base station to its rate control active set. Note that if the base station is already in the rate control active set, blocks 2745 and 2750 may be omitted (details not shown). If, in decision block 2755, the base station is currently in the rate control active set, proceed to block 2760 to remove it since it no longer meets the criteria. In block 2765, the mobile station is sent a message or signal indicating the corresponding base station should be removed from the rate control active set. In decision block 2770, if the information received indicates that the base station meets the criteria for selection in the acknowledgment active set, proceed to block 2775. Otherwise, proceed to decision block 2785. Various criteria, including signal strength, may be used in making the determination. Examples of other factors that may be included are described above. In block 2775, the base station has met the criteria, so the base station is added to the acknowledgment active set for the corresponding mobile station. In block 2780, a message or signal is sent to the mobile station indicating that it should add the base station to its acknowledgment active set. Note that if the base station is already in the acknowledgment active set, blocks 2775 and 2780 may be omitted (details not shown). If, in decision block 2785, the base station is currently in the acknowledgment active set, proceed to block 2790 to remove it since it no longer meets the criteria. In block 2795, the mobile station is sent a message or signal indicating the corresponding base station should be removed from the acknowledgment active set. The process depicted for method 2700 may be repeated for multiple base stations for each of a plurality of mobile stations. In alternate embodiments, various subsets of the steps shown may be omitted. For example, if rate control, or grant scheduling, is not supported, the respective steps could be removed. Method steps may be interchanged without departing from the scope of the present invention. FIG. 28 depicts method 2800 for transmission in accordance with an extended active set. The process starts in block 2810. According to the communication system or standard being deployed, each of the mobile stations in a system make measurements of the various base stations surrounding them. System measurements may also be made at various base stations deployed throughout the system. The measurements may be relayed to a central processing location, such as a BSC, or to various destinations for use in distributed computation. In block 2815, an extended active set is generated or updated for each of the mobile stations in the system. The measurements made, and other criteria, examples of which are detailed above, may be used to determine the extended active set. In the example embodiment, an acknowledgement active set, a grant active set, and a rate control active set are included in the extended active set. In alternate embodiments, other selected active sets may be deployed. In block 2820, the active set information, such as updated extended active sets, is signaled to the appropriate target. In one example, an active set is signaled from the BSC to each mobile station, through one or more base stations. In alternate embodiments, if part or all of the extended active set is determined in other locations, such as at a mobile station or base station, the determination is then transmitted to the BSC or other base stations, as appropriate. In block 2825, the base stations are signaled to indicate which channels to transmit to various mobile stations in accordance with the extended active set. For example, a base station added to a mobile station's grant active set would be signaled that it may issue grants, as applicable, to the respective mobile station. Naturally, base stations need only be signaled when a change in their status occurs. In block 2830, send acknowledgements to the mobile stations in the system via base stations in accordance with the acknowledgement active sets. The transmission of an acknowledgement command or signal may be made in accordance with any of the examples detailed above, as well as any other technique known in the art. In block 2835, send grants to the mobile stations in the system via base stations in accordance with the grant active sets. The transmission of a grant may be made in accordance with any of the examples detailed above, as well as any other technique known in the art. In block 2840, send rate control commands to the mobile stations in the system via base stations in accordance with the rate control active sets. The transmission of a rate control command or signal may be made in accordance with any of the examples detailed above, as well as any other technique known in the art. In block 2845, each mobile station monitors the channels according to the respective extended active sets. In block 2850, the mobile stations transmit in response to the commands received on the monitored channels. FIG. 29 depicts example method 2900 for communicating with an extended active set in a mobile station, such as mobile station 106. The process begins in block 2910, where the mobile station measures surrounding base stations. A mobile station may be signaled from a base station or a BSC the parameters to be used for neighboring base station measurement. In an alternate embodiment, extended active set generation may be made without mobile station generated measurements. In block 2915, the mobile station transmits active set information to the BSC (or other active set processing device, such as a base station, or other central processor). The active set may include the measurements made in block 2910. Any active set selection made in the mobile station may also be transmitted, as necessary. For example, in a 1xEV-DV system, a mobile station may autonomously select the serving base station. Such a selection may be signaled from a base station, or from the mobile station itself. As detailed above with respect to FIGS. 27-28, a BSC or other device may update the extended active sets, in accordance with mobile station generated information, among other criteria. If an extended active set modification is made, it may be signaled to the corresponding mobile station. In decision block 2920, if an active set update is received, proceed to block 2925 to modify the respective active set or sets. Proceed to decision block 2930. In decision block 2930, if there are one or more base stations in the acknowledgment active set, monitor the acknowledgment channels from the respective base stations, as shown in block 2935. Then proceed to decision block 2940. In decision block 2940, if there are one or more base stations in the grant active set, monitor the grant channels from the respective base stations, as shown in block 2945. Then proceed to decision block 2950. In decision block 2950, if there are one or more base stations in the rate control active set, monitor the rate control channels from the respective base stations, as shown in block 2955. Then proceed to block 2960. In decision block 2960, the mobile station may adjust its transmission rate in response to any grants or rate control commands it may have received on the monitored channels. The mobile station may transmit a new packet or retransmit a previously transmitted packet in response to any acknowledgment commands or messages on the monitored channels. Then the process may stop. FIG. 30 depicts example messages suitable for communicating changes to an extended active set. These messages may be deployed with any of the previously described methods. It will be apparent to those of skill in the art that the messages depicted in FIG. 30 are illustrative only. The messages may be fixed or variable length. The fields of the messages may be of any size. Messages may be adapted to various modulation formats. Messages may be included with or include other message information for use in the system as well. Myriad message types are known in the art, and may be adapted for use in light of the teaching herein. Add message 3000 may be used to signal that a base station should be added to an extended active set. Note that this message may be transmitted to and from any two devices. In the example embodiment, a BSC may generate most of the messages for transmission to one or more mobile stations through one or more base stations. Field 3005 of the message indicates that the message is an add message. Field 3010 identifies the mobile station associated with the active set, and may be used to identify the recipient of the message. Field 3015 includes an identifier associated with the base station to be added. In an alternate message embodiment, more than one base station may be added at once, thus field 3015 would include one or more base station identifiers. Field 3020 may be used to indicate the active set to which the base station should be added. An identifier may be associated with each active set in the extended active set (i.e., an identifier for the grant active set, another identifier for the rate control active set, another for the acknowledgement active set, and so on). Remove message 3030 may be used to signal that a base station should be removed from the extended active set. Similar to message 3000, there is a field 3035 for identifying the message (which may include other header information as well). Field 3040 identifies the mobile station associated with the active set, and may be used to identify the recipient of the message. Field 3045 includes an identifier associated with the base station to be removed. In an alternate message embodiment, more than one base station may be removed at once, thus field 3045 would include one or more base station identifiers. As with message 3000, a field 3050 may be used to indicate the active set to which the base station should be added. List message 3060 may be used to signal an entire active set at once. For example, any of the included active sets in the extended active set may be defined with a list message. A list message may be sent empty to clear an active set. Similar to message 3000 and 3030, there is a field 3065 for identifying the message (which may include other header information as well). Field 3070 identifies the mobile station associated with the active set, and may be used to identify the recipient of the message. Fields 3075A-3075N include identifiers associated with the N base stations to be included in the active set. As with message 3000 and 3030, a field 3080 may be used to identify the active set defined by the list of base stations. It should be noted that in all the embodiments described above, method steps can be interchanged without departing from the scope of the invention. The descriptions disclosed herein have in many cases referred to signals, parameters, and procedures associated with a 1aEV-DV system, but the scope of the present invention is not limited as such. Those of skill in the art will readily apply the principles herein to various other communication systems. These and other modifications will be apparent to those of ordinary skill in the art. Those of skill in the art would understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention. The various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal. The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. | <SOH> BACKGROUND <EOH>1. Field The present invention relates generally to wireless communications, and more specifically to active sets for grant, acknowledgement, and rate control channels. 2. Background Wireless communication systems are widely deployed to provide various types of communication such as voice and data. A typical wireless data system, or network, provides multiple users access to one or more shared resources. A system may use a variety of multiple access techniques such as Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), Code Division Multiplexing (CDM), and others. Example wireless networks include cellular-based data systems. The following are several such examples: (1) the “TIA/EIA-95-B Mobile Station-Base Station Compatibility Standard for Dual-Mode Wideband Spread Spectrum Cellular System” (the IS-95 standard), (2) the standard offered by a consortium named “3rd Generation Partnership Project” (3GPP) and embodied in a set of documents including Document Nos. 3G TS 25.211, 3G TS 25.212, 3G TS 25.213, and 3G TS 25.214 (the W-CDMA standard), (3) the standard offered by a consortium named “3rd Generation Partnership Project 2” (3GPP2) and embodied in “TR-45.5 Physical Layer Standard for cdma2000 Spread Spectrum Systems” (the IS-2000 standard), (4) the high data rate (HDR) system that conforms to the TIA/EIA/IS-856 standard (the IS-856 standard), and (5) Revision C of the IS-2000 standard, including C.S0001.C through C.S0006.C, and related documents (including subsequent Revision D submissions) are referred to as the 1xEV-DV proposal. In an example system, Revision D of the IS-2000 standard (currently under development), the transmission of mobile stations on the reverse link is controlled by base stations. A base station may decide the maximum rate or Traffic-to-Pilot Ratio (TPR) at which a mobile station is allowed to transmit. Currently proposed are two types of control mechanisms: grant based and rate-control based. In grant-based control, a mobile station feeds back to a base station information on the mobile station's transmit capability, data buffer size, and Quality of Service (QoS) level, etc. The base station monitors feedback from a plurality of mobile stations and decides which are allowed to transmit and the corresponding maximum rate allowed for each. These decisions are delivered to the mobile stations via grant messages. In rate-control based control, a base station adjusts a mobile station's rate with limited range (i.e. one rate up, no change, or one rate down). The adjustment command is conveyed to the mobile stations using a simple binary rate control bit or multiple-valued indicator. Under full buffer conditions, where active mobile stations have large amounts of data, grant based techniques and rate control techniques perform roughly the same. Ignoring overhead issues, the grant method may be better able to control the mobile station in situations with real traffic models. Ignoring overhead issues, the grant method may be better able to control different QoS streams. Two types of rate control may be distinguished, including a dedicated rate control approach, giving every mobile station a single bit, and common rate control, using a single bit per sector. Various hybrids of these two may assign multiple mobile stations to a rate control bit. A common rate control approach may require less overhead. However, it may offer less control over mobile stations when contrasted with a more dedicated control scheme. As the number of mobiles transmitting at any one time decreases, then the common rate control method and the dedicated rate control approach each other. Grant based techniques can rapidly change the transmission rate of a mobile station. However, a pure grant based technique may suffer from high overhead if there are continual rate changes. Similarly, a pure rate control technique may suffer from slow ramp-up times and equal or higher overheads during the ramp-up times. Neither approach provides both reduced overhead and large or rapid rate adjustments. An example of an approach to meet this need is disclosed in U.S. patent application Ser. No. ______ (ATTORNEY DOCKET NO. 030525), entitled “COMBINING GRANT, ACKNOWLEDGEMENT, AND RATE CONTROL COMMANDS”, filed Feb. 17, 2004, assigned to the assignee of the present invention. In addition, it may be desirable to reduce the number of control channels, while maintaining desirable probability of error for the associated commands on the control channels. There is a need in the art for a system that provides the ability to control the rates of (or the allocation of resources to) both individual mobile stations as well as groups of mobile stations, without unduly increasing channel count. Furthermore, there is a need to be able to tailor the probability of error of various rate control or acknowledgement commands. An example of an approach to meet this need is disclosed in U.S. patent application Ser. No. ______ (Attorney Docket No. 030560), entitled “EXTENDED ACKNOWLEDGEMENT AND RATE CONTROL CHANNEL”, filed Feb. 17, 2004, assigned to the assignee of the present invention. While the flexibility of control afforded with combined grant, rate controlled, and acknowledged transmission allows for tailoring of the allocation of system resources, it may be desirable to control the role of various base stations in a system with respect to which signals they transmit and in which allocation controls they may participate. An ad-hoc signaling scheme to provide control may be costly in terms of the overhead required for signaling. Failing to control the reach of some base stations may also cause system performance issues if a grant or rate control command is issued, with effects that are not apparent to the issuing base station. There is therefore a need in the art for efficient management of grant, acknowledgement, and rate control channels. | <SOH> SUMMARY <EOH>Embodiments disclosed herein address the need in the art for efficient management of grant, acknowledgement, and rate control channels. In one aspect, a list associated with a first station is generated or stored, the list comprising zero or more identifiers, each identifier identifying one of a plurality of second stations for sending a message to the first station. In another aspect, sets of lists for one or more first stations are generated or stored. In yet another aspect, the messages may be acknowledgements, rate control commands, or grants. In yet another aspect, messages comprising one or more identifiers in the list are generated. Various other aspects are also presented. These aspects have the benefit of reduced overhead while managing grant, acknowledgment and rate control messaging for one or more remote stations. | 20040219 | 20061024 | 20050210 | 67921.0 | 0 | PATEL, AJIT | GRANT, ACKNOWLEDGEMENT, AND RATE CONTROL ACTIVE SETS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,783,085 | ACCEPTED | Foldable massaging bed rest | A foldable massaging bed cushion for supporting a person in a sitting position is disclosed. The foldable massaging bed cushion has a backrest with two side edges, two armrests rotatably coupled to the backrest, and one or more massaging units within the backrest. The two armrests can rotate from a sitting position to a folded position along the two side edges of the backrest. The foldable massaging bed cushion can also have one or more heating units and one more massaging units located within the backrest and a control panel to control the massaging units and heating units. | 1. A massaging bed cushion for supporting a person in a sitting position, comprising: a backrest with two side edges; two armrests rotatably coupled to the backrest wherein the two armrests can rotate from a sitting position to a folded position along the two side edges of the backrest; and one or more massaging units within the backrest. 2. The massaging bed cushion of claim 1, wherein the two armrests are perpendicular to the backrest in the sitting position. 3. The massaging bed cushion of claim 1, wherein the two armrests rotate from zero to one hundred and eighty degrees from the backrest. 4. The massaging bed cushion of claim 1, wherein the sitting position is formed by rotating the two armrests from about forty-five to about one hundred and thirty-five degrees from the backrest. 5. The massaging bed cushion of claim 1, further comprising: one or more latches that prevent the two armrests from rotating about the backrest beyond the sitting position. 6. The massaging bed cushion of claim 1, wherein the backrest and the two armrests form nearly a rectangular top profile in the folded position. 7. The massaging bed cushion of claim 1, wherein the one or more massaging units are massaging motors. 8. The massaging bed cushion of claim 1, wherein the one or more massaging units are pulsating transducers. 9. The massaging bed cushion of claim 1, further comprising: a control panel wherein the control panel is coupled by electrical communication to the one or more massaging units. 10. The massaging bed cushion of claim 9, wherein the control panel is located in one of the two armrests. 11. The massaging bed cushion of claim 1, further comprising a control panel and one more heating sources located within the backrest and controlled by the control panel, wherein the control panel is coupled by electrical communication to the one or more heating units. 12. The massaging bed cushion of claim 1, further comprising a power supply wherein the power supply is coupled by electrical communication to a control panel. 13. The massaging bed cushion of claim 12, wherein the power supply is a battery. 14. The massaging bed cushion of claim 1, wherein the backrest comprises a rectangular frame covered by a cushion and a fabric. 15. The massaging bed cushion of claim 1, wherein the two armrests are coupled to the backrest by an axle that runs through a bottom portion of the backrest. 16. A massaging cushion, comprising: a backrest having a right side and a left side; a right armrest rotatably coupled to the right side of the backrest; a left armrest rotatably coupled to the left side of the backrest wherein the right armrest and the left armrest can rotate into a folded position wherein the right armrest and left armrest are parallel to the left side and right side of the backrest; and one or more massaging units located within the backrest. 17. The massaging cushion of claim 16, wherein the right armrest and the left armrest rotate to form a sitting position. 18. The massaging cushion of claim 16, wherein the right armrest and the left armrest rotate from zero to one hundred and eighty degrees from the backrest. 19. The massaging cushion of claim 16, wherein the sitting position is formed by rotating the right armrest and the left armrest from about forty-five to about one hundred and thirty-five degrees from the backrest. 20. The massaging cushion of claim 16, further comprising one or more latches that prevent the right armrest and left armrest from rotating about the backrest beyond the sitting position. 21. The massaging cushion of claim 16, wherein the backrest, the right armrest, and the left armrest form nearly a rectangular top profile in the folded position. 22. The massaging cushion of claim 16, wherein the one or more massaging units are massaging motors. 23. The massaging cushion of claim 16, wherein the one or more massaging units are pulsating transducers. 24. The massaging cushion of claim 16, further comprising a control panel wherein the control panel is coupled by electrical communication to the one or more massaging units. 25. The massaging cushion of claim 24, wherein the control panel is located in either the right armrest or left armrest. 26. The massaging cushion of claim 24, further comprising one more heating sources located within the backrest and controlled by the control panel wherein the control panel is coupled by electrical communication to the one or more heating sources. 27. The massaging cushion of claim 24, further comprising a power supply wherein the power supply is coupled by electrical communication to the control panel. 28. The massaging cushion of claim 27, wherein the power supply is a battery. 29. The massaging cushion of claim 16 wherein the backrest is a fabric-covered, rectangular cushion. 30. The massaging cushion of claim 16, wherein the right armrest and left armrest are coupled to the backrest by an axle running through a bottom portion of the backrest. 31. A massaging bed cushion, comprising: means for back support with two side edges; two means for arm resting rotatably coupled to the means for back support wherein the two means for arm resting can rotate from a sitting position to a folded position along the two side edges of the means for back support; and one or more means for massaging within the means for back support. | FIELD OF THE INVENTION The present invention is generally related to a massaging bed rest, and more particularly is related to a massaging bed rest with rotatable armrests. BACKGROUND OF THE INVENTION Cushioned bed loungers are known in the art. Bed loungers normally include a back portion and arm rests or elbow rests. The back portion may be contoured and may include a padded neck or head rest. Chair back massagers also are known in the art. One form of prior art back massager is in the form of a pad containing a mechanical massage arrangement powered by electricity. In use, a person places the massager against the back of a chair, automobile seat, or couch and then sits downs and leans back against the massaging device. Other configurations have the massaging elements built into the seat back, for example in a lounge chair or automobile seat. Such massagers include a back portion including a massaging element driven by an electric motor. U.S. Pat. No. 5,895,365, by Tomlinson, discloses a bed rest cushion for providing a vibrating massage including a back portion and two armrests. The two armrests are pivotally coupled to the back portion. However, the armrests are coupled to allow the armrest to rotate outward from the back portion. The armrests do not rotate about the sides of the back portion. The rotation of the bed rest cushion described by Tomlinson does not facilitate storage of the bed rest cushion, nor using the bed rest as a flat massaging cushion for placement in a chair or under the chest of a person when laying down on their stomach. Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies. SUMMARY OF THE INVENTION In one aspect, the invention features a foldable massaging bed cushion for supporting a person in a sitting position. The massaging bed cushion contains a backrest with two side edges, two armrests rotatably coupled to the backrest, and one or more massaging units within the backrest. The two armrests can rotate from a sitting position to a folded position along the two side edges of the backrest. The two armrests can be perpendicular to the backrest in the sitting position. In addition, the two armrests can rotate from zero to one hundred and eighty degrees from the backrest. The sitting position is formed by rotating the two armrests from about forty-five to about one hundred and thirty-five degrees from the backrest. Preferably, the sitting position is formed by rotating the two armrests to ninety degrees (90°) from the backrest. The backrest and the two armrests can form nearly a rectangular top profile in the folded position. Other features and advantages of the present invention will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional features and advantages be included within this description, be within the scope of the present invention, and be protected by the accompanying claims. BRIEF DESCRIPTION OF THE DRAWINGS Many aspects of the invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. FIG. 1 is a perspective view of the massaging cushion unfolded for use in a sitting position, in accordance with a first exemplary embodiment. FIG. 2 is a side view of the massaging cushion of FIG. 1 unfolded for use in the sitting position. FIG. 3 is a front view of the massaging cushion of FIG. 1 unfolded for use in the sitting position. FIG. 4a is a block diagram illustrating interaction of the interior components of the massaging cushion of FIG. 1, in accordance with the first exemplary embodiment of the invention. FIG. 4b is a block diagram illustrating the interaction of the interior components of the massaging cushion of FIG. 1, in accordance with a second exemplary embodiment of the invention. FIG. 5 is a perspective view of the massaging cushion of FIG. 1 folded into a storage position or for use in a laying down position. FIG. 6 is a top view of the massaging cushion of FIG. 1 folded into a flattened position for use in a laying down position or for storage in accordance with the first exemplary embodiment of the invention. FIG. 7 is a perspective view of a massaging cushion folded into a flattened position for use in a lying down position or for storage in accordance with a third exemplary embodiment of the invention. DETAILED DESCRIPTION FIG. 1 is a perspective view, FIG. 2 is a side view, and FIG. 3 is a front view of the massaging cushion 100 unfolded for use in a sitting position, in accordance with a first exemplary embodiment of the invention. The massaging cushion 100 comprises a backrest 102, a right armrest 104, and a left armrest 106. An axle 108 couples the right armrest 104 and left armrest 106 to the backrest 102. In addition, the axle 108 runs through a lower portion 110 of the backrest 102. The axle 108 allows the right armrest 104 and left armrest 106 to rotate about the backrest 102 as indicated by the arrows shown in FIG. 1 and FIG. 2. When the massaging cushion 100 is unfolded into a sitting position, the user sits between the right armrest 104 and left armrest 106. The right and left arms of the user rest on the right armrest 104 and the left armrest 106, respectively. The back of the user rests on a front surface 118 of the backrest 102 of the massaging cushion 100. The weight of the arms and upper body of the user rests upon the right armrest 104 and left armrest 106. The weight on the armrests 104 and 106 upon the floor provides a frictional force that prevents the backrest 102 from sliding backwards when using the massaging cushion 100 in the sitting position. Alternatively, while resting on the massaging cushion 100, a back surface 120 of the backrest 102 may be leaned against a wall, a back portion of a bed, or any other surface that will prevent the backrest 102 from moving backward. The axle 108 allows the right armrest 104 and left armrest 106 to rotate about the backrest 102. In the first exemplary embodiment, the right armrest 104 and left armrest 106 can rotate one hundred and eighty degrees from the backrest 102. When the massaging cushion 100 is in the sitting position, the right armrest 104 and left armrest 106 are rotated between about ninety degrees to about one hundred and twenty degrees from the backrest 102. The lower backside of the user prevents the backrest 102 from rotating out of the sitting position. The user can adjust the slant of the backrest 102 by moving the lower backside of the user closer or further away from the lower portion 110 of the backrest 102. By moving the lower backside of the user closer to the backrest 102, the angle between the armrests 104 and 106 and the backrest 102 is decreased. By moving the lower backside of the user further away from the lower portion 110 of the backrest 102, the backrest 102 is allowed to rotate, increasing the angle between the armrests 104 and 106 and the backrest 102. The left armrest 106 and right armrest 104 may rotate about the axle 108 together or separately. As an example, movement of the left armrest 106 may force the right armrest 104 to rotate with the left arm rest 106. Alternatively, the left armrest 106 may rotate about the axle 108 independent from the right armrest 104 These different examples of movement of the left armrest 106 and right armrest 104 may be made possible by a series of gears, joints, or any other device known by those having ordinary skill in the art that may allow and/or limit rotation about the axle 108. In another embodiment, a rotation latch (not shown) can be used to prevent the backrest 102 from rotating out of the sitting position. The rotation latch prevents the right armrest 104 and left armrest 106 from rotating beyond a desired angle from the backrest 102. For example, the rotation latch can allow the backrest 102 to rotate one hundred degrees from the right armrest 104 and the left armrest 106. This allows the massaging cushion 100 to remain in the sitting position without relying on support from the arms and lower backside of the user. In addition, the rotation latch can also be an adjustable latch that allows the user to set a maximum angle of rotation. This allows the user to customize and set the maximum angle between the armrest 104, 106 and the backrest 102 that is allowed by the massaging cushion 100. A control panel 112 located on a top surface of the right armrest 104 allows the user to activate one or more massaging units 114 and one or more heating units 116. The location of the control panel 112 provides easy access by the hands of the user when the user is being supported by the massaging cushion 100 adjusted to the sitting position. The control panel 112 is not limited to being located on the top surface of the right armrest 104. The control panel 112 can instead be mounted on a variety of different locations and surfaces of the massaging cushion 100. The control panel 112 can contain various displays, switches, and knobs used to control the one or more massaging units 114 and the one or more heating units 116. For example, the knobs or switches can be used to control the amount of heat provided by the heating units 116. The knobs or switches can also be used to control the massaging intensity and motion of the massaging units. The display can be a Light Emitting Diode (LED) display that shows the current settings of the one or more massaging units 114 and one or more heating units 116. The one or more massaging units 114 can be located within the backrest 102. In addition, the one or more massaging units 114 can be built into the cushion of the backrest 102. The massaging units 114 can be a variety of massaging devices arranged within the backrest 102, for example, but not limited to, massage motors, pulsating transducers, and powered rollers. The location of the massaging units 114 can be a variety of locations and surfaces on the massaging cushion 100, for example, but not limited to, the top surface or inside surface of the armrests 104 and 106. Along with the one or more massaging units 114, the massaging cushion 100 can also have the one or more heating units 116. Similar, to the massaging units 114, the one or more heating units 116 can also be built into the cushion of the backrest 102. The heating units 116 also can be located in a variety of locations and surfaces of the massaging cushion 100. In addition, the heating units 116 may be located within the armrests 104, 106. During use, the heating unit 116 can generate heat when current is applied to the heating element. Other means for providing heat would be known by those having ordinary skill in the art. The control panel 112 can regulate both the one or more massaging units 114 and the heating units 116. The control panel 112 can also selectively activate the massaging units 114 and heating units 116 in a variety of patterns, providing different massaging sequences. These sequences can be stored in a memory of the control panel 112. A user can select a desired sequence on the control panel 112 and the control panel 112 can activate the different massaging units 114 and heating units 116 based on the selected pattern of the user. FIG. 4a is a block diagram illustrating interaction of interior components 400a of the massaging cushion 100 in accordance with a first exemplary embodiment of the invention. The control panel 112a can be electrically coupled to each massaging unit 114a and each heating unit 116a. A power source 402a supplies the power to operate the control panel 112a. The control panel 112a selectively supplies power to each of the massaging units 114a and each of the heating units 116a depending on the control panel 112a setting. The control panel 114a controls each massaging unit 114a and each heating unit 116a by varying the amount of current supplied to each massaging unit 114a and each heating unit 116a. FIG. 4b is a block diagram illustrating interaction of interior components 400b of the massaging cushion 100 in accordance with a second exemplary embodiment of the invention. The power source 402b can be electrically coupled to the control panel 112b, the one or more massaging units 114b, and the one or more heating units 116b. The power source 402b supplies power directly to each component. The control panel 112b can be electrically coupled to each massaging unit 114b and each heating unit 116b or the control panel 112b can be connected to each massaging unit 114b and each heating unit 116b by wireless communication. The control panel 112b signals each of the massaging units 114b and each of the heating units 116b by electrical pulse or a wireless communication protocol based on the desired setting selected by the user via the control panel 112b. Each of the massaging units 114b and each of the heating units 116b respond to the signals by adjusting to the desired setting. For example, a heating unit 116b that receives the signals from the control panel 112b to increase the temperature, would increase the current to the heating unit 116b. The power source 402a and 402b can be a battery mounted within the backrest 102, the right armrest 104, or the left armrest 106. In addition to the power source 402a, 402b being a battery, the power source 402a, 402b can also be an electrical plug that enters through a surface on the massaging cushion 100. The user would plug the electrical plug into a wall socket to supply the power to run the control panel 112, the one or more massaging units 114, and the one or more heating units 116. The power source 402a, 402b can also be a combination of the electrical plug and the battery. For example, the battery can be a rechargeable battery that supplies the power for the massaging cushion 100 when the massaging cushion 100 is used in a location remote from a wall socket. The massaging cushion 100 can also have the electrical plug used to recharge the battery or supply power when the massaging cushion 100 is used in a location within reach of a wall socket. The massaging cushion 100 can be constructed of a solid frame with foam or padding material located between the solid frame and a cover. The cover can be made from a variety of materials, for example, but not limited to, fabric, leather, or vinyl. The solid frame can be made of a variety of materials, for example, wood, metal, or plastic. Instead of a solid frame surrounded by padding material, the frame can also be constructed using a semi-hard foam rubber. The semi-hard foam rubber would not require the additional padding material. The control panel 112, massaging units 114, and heating units 116 can be supported by the solid frame or the semi-hard foam rubber frame within the massaging cushion 100. The massaging cushion 100 can be constructed to have a relatively flat surface profile as shown in FIGS. 1-3. The massaging cushion 100 can also be constructed to have a more contoured profile that conforms to the contours of the human body. FIG. 5 is a perspective view and FIG. 6 is a top view of the massaging cushion 100 folded into a flattened position for use in a lying down position or for storage in accordance with the first exemplary embodiment of the invention. The right armrest 104 and left armrest 106 may be folded inline with the backrest 102. This allows the massaging cushion 100 to have a rectangular shape when in the flattened position to facilitate storage. Due to rectangular shape when in the flattened position, multiple massaging cushions 100 can be stacked vertically or the massaging cushion can be easily stored on a shelf in the folded position. In addition, when in the flattened position, the massaging cushion 100 easily fits within a rectangular storage device, such as, but not limited to, a box. The massaging cushion 100 can also be used as a massaging pillow in the folded position. The user can sit on top of the massaging cushion 100 while the massaging cushion 100 provides a massage to the lower back and thighs of the user. A user can also use the massaging cushion 100 in the folded position to prop up the chest of the user when the user is lying on their stomach. In this position the massaging cushion 100 can be used to provide a massage to the chest of the user. As previously discussed, the massaging units 114 and heating units 116 can be provided on a variety of surfaces and locations on the massaging cushion 100. The massaging units 114 and heating units 116 can be provided on both the back surface 120 and the front surface 118 of the backrest 102. This allows the user to use the massaging cushion 100 in the sitting position or in the folded position as a pillow while maintaining easy access to the control panel 112. The massaging units 114 and heating units 116 can also be centrally located within the backrest 102 so as to provide a massaging effect and heating to both the back surface 120 and the front surface 118 of the backrest 102 from within the backrest 102. FIG. 7 is a top view of the massaging cushion 700 folded into a flattened position for use in a lying down position or for storage in accordance with a third exemplary embodiment of the invention. In the third exemplary embodiment, the axle 108 shown in FIG. 1 does not run all the way through the backrest 102. Instead, in the third exemplary embodiment of the right armrest 706 is coupled to the backrest 702 by a right axle 707 and the left armrest 704 is coupled to the backrest 702 by a left axle 709. The right axle 707 and left axle 709 allow the right armrest 706 and left armrest 704 to rotate about the backrest 702. The third exemplary embodiment also allows the right armrest 706 and left armrest 704 to rotate independently about the backrest 702. It should be emphasized that the above-described embodiments of the present invention are merely possible examples of implementations merely set forth for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described embodiment(s) of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of this disclosure and the present invention and protected by the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Cushioned bed loungers are known in the art. Bed loungers normally include a back portion and arm rests or elbow rests. The back portion may be contoured and may include a padded neck or head rest. Chair back massagers also are known in the art. One form of prior art back massager is in the form of a pad containing a mechanical massage arrangement powered by electricity. In use, a person places the massager against the back of a chair, automobile seat, or couch and then sits downs and leans back against the massaging device. Other configurations have the massaging elements built into the seat back, for example in a lounge chair or automobile seat. Such massagers include a back portion including a massaging element driven by an electric motor. U.S. Pat. No. 5,895,365, by Tomlinson, discloses a bed rest cushion for providing a vibrating massage including a back portion and two armrests. The two armrests are pivotally coupled to the back portion. However, the armrests are coupled to allow the armrest to rotate outward from the back portion. The armrests do not rotate about the sides of the back portion. The rotation of the bed rest cushion described by Tomlinson does not facilitate storage of the bed rest cushion, nor using the bed rest as a flat massaging cushion for placement in a chair or under the chest of a person when laying down on their stomach. Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies. | <SOH> SUMMARY OF THE INVENTION <EOH>In one aspect, the invention features a foldable massaging bed cushion for supporting a person in a sitting position. The massaging bed cushion contains a backrest with two side edges, two armrests rotatably coupled to the backrest, and one or more massaging units within the backrest. The two armrests can rotate from a sitting position to a folded position along the two side edges of the backrest. The two armrests can be perpendicular to the backrest in the sitting position. In addition, the two armrests can rotate from zero to one hundred and eighty degrees from the backrest. The sitting position is formed by rotating the two armrests from about forty-five to about one hundred and thirty-five degrees from the backrest. Preferably, the sitting position is formed by rotating the two armrests to ninety degrees (90°) from the backrest. The backrest and the two armrests can form nearly a rectangular top profile in the folded position. Other features and advantages of the present invention will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional features and advantages be included within this description, be within the scope of the present invention, and be protected by the accompanying claims. | 20040220 | 20080212 | 20050908 | 75981.0 | 1 | MAYO-PINNOCK, TARA LEIGH | FOLDABLE MASSAGING BED REST | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,783,199 | ACCEPTED | System and method of using a side-mounted interferometer to acquire position information | A system and method for acquiring position information of a movable apparatus relevant to a specific axis is disclosed. In one embodiment, an interferometer generates first and second beams and various beam-steering members are located to define beam path segments for the two beams, but no beam path segment varies in length in unity with displacements of the movable apparatus along the specific axis. In another or the same embodiment, each beam path segment in which the first beam either impinges or has been reflected from the movable apparatus is symmetrical to a corresponding beam path segment of the second beam. The movable apparatus may be a wafer stage in which the “specific axis” is the exposure axis of a projection lens, but with all optical members which cooperate with the stage being located beyond the ranges of the wafer stage in directions perpendicular to the lithographic exposure axis. | 1. A system for acquiring position information relevant to a specific axis comprising: a movable apparatus having first and second reflective faces at a side associated with a parallel to said specific axis, said first reflective face being at an angle to said second reflective face and said first and second reflective faces being non-parallel to said specific axis; an interferometer positioned to direct a first beam for impingement of said first reflective face and to direct a second beam for impingement of said second reflective face, said interferometer including a beam combiner aligned with a detector; and beam-steering members located with respect to said interferometer and said first and second reflective faces to manipulate said first and second beams to reach said beam combiner without a beam path segment that varies in length in unity with displacements of said movable apparatus along said specific axis. 2. The system of claim 1 wherein said first and second reflective faces are surfaces that are angled such that beam paths of said first and second beams vary in opposition when said movable apparatus is displaced along said specific axis. 3. The system of claim 2 wherein said interferometer is configured to generate said first and second beams and to direct said first and second beams at a generally perpendicular angle with respect to displacement of said movable apparatus along said specific axis, said first and second reflective faces being oppositely angled as measured with respect to said perpendicular angle. 4. The system of claim 1 wherein said beam-steering members are mirrors that are positioned such that, when said movable apparatus is in a symmetry position on said specific axis, each beam path segment in which said first beam either impinges or has been reflected from said movable apparatus is symmetrical to a corresponding beam path segment of said second beam. 5. The system of claim 4 wherein said beam-steering members include first and second beam-return mirrors respectively aligned with and oriented to said first and second reflective faces to define return beam path segments, said first beam thereby reflecting from said first reflective face to said first beam-return mirror and being reflected back to said first reflective face, said second beam thereby reflecting from said second reflective face to said second beam-return mirror and being reflected back to said second reflective face. 6. The system of claim 5 wherein said first and second beam-return mirrors are in any orientation and are selected from at least one of the following types: reflective components, including plane mirrors and roof mirrors, refractive components, diffractive components, and holographic components. 7. The system of claim 1 wherein said movable apparatus is a support stage within a wafer lithography system having a lithography optical axis, said support stage being mounted for movement in directions perpendicular to said lithography optical axis and for movement aligned with said lithography optical axis, said specific axis being said lithography optical axis. 8. The system of claim 7 wherein said interferometer includes a laser source and a beam splitter that are cooperative to emit said first and second beams with differences in at least one of frequencies and polarization. 9. The system of claim 6 wherein said beam-steering members remain beyond reaches of said support stage in said X and Y directions as said support stage is displaced. 10. A method of utilizing an interferometric system to acquire position information of a movable apparatus along a specific axis comprising: directing first and second beams to impinge said movable apparatus; manipulating said first and second beams via reflections such that each beam path segment in which said first beam either impinges or has been reflected from said movable apparatus is symmetrical to a corresponding beam path segment of said second beam when said movable apparatus is in a beam symmetry position along said specific axis; combining said first and second beams as a basis for interferometrically acquiring said position information. 11. The method of claim 10 wherein directing said first and second beams toward said movable apparatus is a step in which said first and second beams are optically distinguishable with respect to at least one of frequency and polarization and wherein said movable apparatus is a wafer stage. 12. The method of claim 11 wherein manipulating said first and second beams includes positioning mirrors to define said beam path segments in which said first and second beams either impinge or have been reflected from said wafer stage, including locating said mirrors beyond ranges of motion of said wafer stage in directions perpendicular to said specific axis, said wafer stage including first and second reflective faces in alignment with said beam path segments. 13. The method of claim 12 wherein positioning said mirrors includes selecting said mirrors from at least one of the following types: reflective components, including plane mirrors and roof mirrors, refractive components, diffractive components, and holographic components. 14. The method of claim 10 wherein manipulating said first and second beams is implemented without maintaining a beam path segment that is parallel to said specific axis and that varies in length with displacement of said movable apparatus along said specific axis. 15. The method of claim 14 wherein manipulating said first and second beams includes providing said movable apparatus to include first and second reflective faces that are oppositely sloped with respect to a plane perpendicular to said specific axis. 16. A system for acquiring position information relevant to a specific axis comprising: a wafer stage movable in X and Y directions and in a perpendicular Z direction, said Z direction being aligned with a lithography exposure axis, wherein a perimeter is defined by extremes of travel of said wafer stage in said X and Y directions, said wafer stage having first and second surfaces on a side thereof: a source of first and second beams, said first beam being directed to reflect from said first surface and said second beam being directed to reflect from said second surface; a plurality of optical members arranged to define first and second beam paths for said first and second beams following reflections from said first and second surfaces, said optical members being located beyond projections of said perimeter in said Z direction, wherein both of said first and second beam paths vary in length when said wafer stage is moved in said Z direction; a beam combiner at ends of said first and second beam paths to combine said first and second beams; and a processor operatively associated with said beam combiner for acquiring interferometry-based determinations regarding movements of said wafer stage in said Z direction. 17. The system of claim 16 wherein said source emits said first and second beams having different frequencies and different polarizations. 18. The system of claim 16 wherein said optical members include a first mirror aligned with and oriented to said first surface of said wafer stage to redirect said first beam back to said first surface, said optical members further including a second mirror aligned with and oriented to said second surface of said wafer stage to redirect said second beam back to said second surface. 19. The system of claim 18 wherein said first and second surfaces of said wafer stage are oppositely sloped with respect to a plane perpendicular to said Z direction. 20. The system of claim 19 wherein said opposite slopes are such that said first and second beam paths vary in opposition when said wafer stage is moved in said Z direction. 21. The system of claim 18 wherein said first and second mirrors for respectively redirecting said first and second beams are in any orientation and are selected from at least one of the following types: reflective components, including plane mirrors and roof mirrors, refractive components, diffractive components, and holographic components. | BACKGROUND ART In various applications, it is necessary to acquire precise information regarding the position of an object. The object of interest may be fixed in position or may be a movable one. By way of example, positioning systems and measuring systems that are used in the integrated circuit fabrication industry must have a high level of accuracy. Prior to wafer dicing, an array of identical integrated circuits is formed on a semiconductor wafer by stepping the wafer relative to a system or system component, such as an image-bearing reticle. Often, both the reticle and the wafer are connected to stages which are movable. As used herein, a “wafer stage” includes both an apparatus for supporting the wafer and/or the apparatus for supporting the reticle. A typical wafer stage is movable in perpendicular X and Y directions. The wafer stage can therefore be stepped after each exposure of the wafer. For example, in the use of a reticle, a photoresist layer may be repetitively exposed onto a wafer by projecting an image of the reticle through a projection lens to one area on the wafer, stepping the wafer stage, and repeating the exposure. The wafer is scanned using the X and Y movements of the wafer stage until each integrated circuit region is properly exposed. In addition to the movements in the X and Y directions, Z axis movement is enabled. In wafer lithography, the Z axis may also be considered the exposure optical axis or the “focus” axis. The required range of motion in the Z direction is significantly less than the necessary ranges in the X and Y directions. Acquiring position information regarding movement of a wafer stage in the Z direction is somewhat more problematic than acquiring such information for X and Y movements. An approach to providing Z axis measurements is to use an encoder that employs interferometric techniques. One concern with this approach is that interferometer components must be relatively large in order to capture the diffracted orders as the stage translates through its full range, since the required diffraction angle must be relatively great in order to achieve the target accuracy. As an alternative, a standard Michelson interferometer may be used to monitor Z axis motions. However, if the measurement is performed from the projection lens side of the wafer stage, the percentage of stage real estate that is available to the wafer or reticle must be smaller (for a given size stage), since the laser light from the interferometer should not impinge the wafer or reticle. On the other hand, if the measurement is performed from the side of the stage opposite to the projection lens, the measurement system must use an intermediate reference, such as the stone below the stage. Among other potential disadvantages, this requires a separate measurement of the stone relative to the projection lens. FIG. 1 illustrates another approach to acquiring position information of a wafer stage 10 along a Z axis. This approach is described in detail in U.S. Pat. No. 6,208,407 to Loopstra. A wafer 12 is shown as being supported on the stage for exposure by projection optics or exposure tool 14. The advantage of this approach is that although the interferometer 16 is positioned at the side of the stage 10, accurate Z axis measurements may be obtained. This is enabled by properly positioning mirrors which establish a Z measuring axis 18 that is parallel to the Z axis 20 of the exposure system. A first mirror 22 is arranged at a forty-five degree angle to movement of the stage 10 along the X or Y direction. A measuring beam 24 from the interferometer impinges the forty-five degree mirror to establish the Z measuring axis 18. A horizontal mirror 26 is attached to structure 28 of the exposure system, so that the beam is redirected to the first mirror 22, which reflects the returned beam to the interferometer 16. In addition to the measuring beam 24, the interferometer projects a test beam 30 for reflection from a vertical surface 31 of the stage 10. As can be seen in FIG. 1, movement of the wafer stage 10 along the Z axis 20 will result in a change in the length of the beam path segment from the forty-five degree mirror 22 to the horizontal mirror 26. Thus, while the interferometer 16 is located at the side of the stage, the measuring beam 24 has a path segment that varies in length in unity with Z axis displacements of the stage. In fact, the reflection from the horizontal mirror 26 to the forty-five degree mirror provides a second beam path segment that varies in unity with Z axis movement of the stage. On the other hand, the length of each beam path segment for the test beam 30 is fixed, unless the stage 10 is moved in the X direction. While the approach described with reference to FIG. 1 operates well for its intended purposes, there are cost concerns, since the horizontal mirror 26 is a relatively large reflective component that requires a high degree of planarity. Moreover, as the linewidths of the features of integrated circuits decrease, the size of the projection lens of the projection optics 14 increases. In FIG. 1, this would result in an increase of the diameter of the projection optics. As a consequence, the requirement of a horizontal mirror 26 to accommodate the entire range of motion of the stage imposes a potential difficulty with respect to achieving further reductions of linewidths. For systems in which the increase in size of a projection lens is not an issue, there may be other reasons for avoiding the use of a horizontal mirror of a similar type and orientation of FIG. 1. SUMMARY OF THE INVENTION A system for acquiring position information of a movable apparatus relevant to a specific axis is achieved without requiring either an interferometer or its beam-steering members to be located in a position that would affect performance or design flexibility of the overall system in which the movable apparatus is a component. For example, where the movable apparatus is a wafer stage and the specific axis is the vertical Z axis, the beam-steering members of the system for acquiring position information are neither directly above nor directly below the wafer stage. In accordance with one embodiment of the invention, the system includes a movable apparatus having first and second reflective faces, an interferometer positioned to direct beams for impingement of the reflective faces, and beam-steering members located with respect to the interferometer and reflective faces to manipulate the reflected beams to reach a beam combiner without requiring a beam path segment that varies in length in unity with displacements of the movable apparatus along the axis. The movable apparatus may be a “wafer stage” on which a wafer or reticle is mounted for movement between steps of integrated circuit fabrication. In this application, the “specific axis” is the Z axis (i.e., the lithography optical axis) and the reflective faces are on the side of the wafer stage associated with a parallel to the Z axis. However, the first and second reflective faces are non-parallel to the Z axis itself. In order to control “walk-off” of the first beam relative to the second beam upon reaching the beam combiner, the angles of the first and second reflective faces and the positions and angles of the beam-steering members are preferably selected such that the two beam paths vary in opposition when the movable apparatus is displaced along the axis for which the position information is being acquired. The interferometer may be configured to direct the first and second beams at a generally perpendicular angle with respect to displacement of the movable member along the specific axis, with the first and second reflective faces being oppositely sloped as measured with respect to the perpendicular angle. The beam-steering members may include first and second beam-return mirrors that are respectively located in alignment with the first and second reflective faces to cause the beams to retrace (e.g., plane mirrors) or to parallel (e.g., roof mirrors) their original beam path segments in returning to the interferometer. In accordance with the method of utilizing the interferometric system to acquire the position information, the first and second beams are generated and directed toward the movable apparatus. As previously noted, the beams may both be at ninety degrees to the specific axis. The two beams are manipulated via reflections such that each beam path segment in which the beam either impinges or is reflected by the movable apparatus is symmetrical to a corresponding beam path segment for the other beam, if the movable member is in its beam symmetry position along the specific axis. However, as the movable apparatus is displaced from its beam symmetry position, at least some of the beam path segments will be changed in length, thereby providing the basis for interferometrically determining the position information. The two beams have different optical characteristics (e.g., frequency and/or polarization), allowing the employment of standard interferometric techniques. The system and method enable all optical members that are mounted to a wafer stage to remain beyond the ranges of the wafer stage movements in the X and Y directions, even if the wafer stage is considered to move beyond its possible range of motion in the Z direction. Consequently, the locations of the optical members are unlikely to affect design considerations of other aspects of the overall system in which the invention resides. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a prior art system for acquiring position information relevant to a specific axis. FIG. 2 is a side view of a system for acquiring position information in accordance with one embodiment of the invention. FIG. 3 is a side view of one possible combination of optical components for splitting and recombining beams of the system of FIG. 2. FIG. 4 is a side view of another embodiment of the invention, using roof mirrors and a divided prism. FIG. 5 is a third possible embodiment of the invention. FIG. 6 is a process flow of steps for utilizing the systems of FIGS. 2-5. DETAILED DESCRIPTION A system for acquiring position information relevant to a specific axis will be described as being used within a lithography environment. However, the invention may be used in other applications. The system is best suited for applications in which the range of movement is relatively minor, compared to a range in motion in either or both of the perpendicular axes. In FIG. 2, the system may be used to monitor motion along a vertical Z direction, which is aligned with the exposure optical axis 32 (or “focus” axis) of a lithography system 34. In this particular application, the movable apparatus includes a wafer stage 36 and a prism reflector 38 having a first reflective face 40 and a second reflective face 42. As previously noted, the term “wafer stage” is defined herein as including stages which support a reticle of the lithography system, but at the upper portion of the system, rather than the lower portion shown in FIG. 2. It should be noted that the lithography system can be rotated, so that the axis is no longer vertical. The position acquisition system includes a source of a first beam 44 and a second beam 46. As one possibility, the source comprises a laser 48 and a beam splitter and recombiner 50. As will be described more fully below, the recombined beams are directed to a detector 52. The laser 48, splitter and recombiner 50, and detector 52 are components of an interferometer. The first and second beams may have different frequencies and polarizations, wherein the different polarizations facilitate separation and recombination of the beams, and wherein the different frequencies facilitate the measurements of beam path lengths, thereby providing the basis for detecting and/or quantifying movements. Merely by way of example, FIG. 3 shows a more detailed arrangement of possible components for implementing the interferometer. The laser 48 may be a standard two-frequency optical laser. The frequency difference can be generated in a number of ways, including, but not limited to, Zeeman split or acousto-optic modulation. A Helium-Neon laser may be used to provide a beam having orthogonal polarized components with a frequency difference. The beam from the laser 48 enters a beam splitter 54 that is polarization sensitive. The first beam 44 having a particular frequency and polarization passes through the beam splitter, while the second beam 46 having a different frequency and a different polarization is internally reflected toward a mirror 56 of the interferometer. Upon exiting from the beam splitter 54, the first and second beams 44 and 46 pass through quarter-wave plates 58 and 60, respectively. Each quarter-wave plate provides circular polarization. The two beams 44 and 46 are directed toward the stage 36 having the mounted wafer 62 at angles less than forty-five degrees relative to the Z axis. In the embodiment of FIG. 3, the angle is ninety degrees relative to the Z axis. Therefore, the angles of the first and second reflective faces 40 and 42 of the prism reflector 38 should be less than forty-five degrees to the incoming beam path. An angle of forty-five degrees or greater would result in a reflection that carries the concerns and disadvantages of prior approaches. The first and second reflective faces 40 and 42 of the prism reflector 38 determine the angles of the next beam path segments. A pair of beam-steering members 64 and 66 is located to again reflect the two beams. Since the reflection is back to the wafer stage, the two optical members may be referred to as beam-return mirrors. The second reflections from the prism reflector 38 direct the first and second beams 44 and 46 back to the interferometer. Each beam follows its original path to the interferometer, where the second beam 46 is again reflected by the interferometer mirror 56. Upon transition through the two quarter-wave plates 58 and 60, the orientations of the two polarizations are such that the first beam 44 is now reflected and the second beam 46 is now propagated without reflection through the beam splitter 54. This produces a combined beam 68 that exits the splitter at its lower port in order to reach the detector 52. Any detector conventionally used in interferometry may be employed. For example, the detector may be a photodiode connected to a conventional amplifier 70 and phase detector 72. As is well known in the art, shifts in phase may be used to acquire position information regarding stage displacement. Returning to FIG. 2, the wafer stage 36 may be considered to be currently in a “symmetry position,” since each of the four beam path segments of the first beam 44 involving contact with the reflective face 40 is symmetrical to a corresponding beam path segment of the second beam 46. That is, in comparing the propagations of the first and second beams, the path lengths between the interferometer 50 and the prism reflector 38 are equal and the path lengths between the prism reflector and the beam-steering mirrors 64 and 66 are equal. However, as the wafer stage 36 is moved upwardly or downwardly along the Z axis, the lengths of the path segments will vary in opposition. Downward movement of the wafer stage will cause the four relevant path segments for the first beam 44 to decrease in length, since the first reflective face 40 is sloped accordingly. On the other hand, the opposite slope of the second reflective face 42 causes the four beam path segments to lengthen with the downward movement. Upward movement of the wafer stage 36 increases the lengths of the path segments for the first beam, but decreases the path segments for the second beam. As can be readily understood, the total length change for each beam path is multiplied by a factor of four, since four path segments vary uniformly. As a result of the multiplication of length variations, the phase detection processing performed on the combined beam 68 may be used to precisely measure the displacements of the wafer stage 36. Referring now to FIG. 4, another embodiment of the invention is illustrated. In this embodiment, a pair of reflectors 74 and 76 takes the place of the single prism reflector of FIGS. 2 and 3. However, the two oppositely sloped reflective faces 40 and 42 are still provided. A more significant difference is that rather than using plane mirrors to provide the beam steering, a pair of roof mirrors 78 and 80 is utilized. A roof mirror may consist of two mirrors joined together at ninety degrees. The roof mirrors are in any orientation that establishes symmetrical beam segments. In some applications, the symmetry requirement is somewhat relaxed, but in such applications there can be no beam path segment that varies in length in unity with displacements of the movable apparatus (such as the wafer stage 36) along the axis of interest (such as the Z axis). The operations of the position information acquisition system of FIG. 4 are generally identical to those of the embodiment of FIG. 2. However, the beam return paths for the first and second beams 44 and 46 will be slightly spaced from the original beam propagation paths. Nevertheless, because the two reflective faces 40 and 42 are oppositely sloped and the roof mirrors are properly oriented, the four beam path segments in which the first beam 44 either impinges or has been reflected from the reflective face 40 will be symmetrical to the corresponding beam path segments for the second beam 46, when the wafer stage 36 is in its symmetry position. Moreover, any movement by the stage along its Z axis will cause the two beam paths to vary in opposition. The interior configuration (not shown) of the beam splitter and recombiner 50 is designed to recombine the two incoming beams to form a single beam 68 directed to the detector 52. Then, conventional techniques may be used to acquire position information regarding the wafer stage 36. FIG. 5 shows another embodiment of the invention. As with FIG. 4, components that are identical to those described with reference to other embodiments are provided with the same reference numerals. A laser 48 provides the input to a beam splitter and recombiner 50. By operation of the beam splitter, first and second beams are provided with a difference in either or both of frequency and polarization. Similar to the embodiments of FIGS. 2, 3 and 4, each of the two beams follows a path that includes four path segments that either impinge or have been reflected by the associated reflective face 40 and 42. Reference numeral 82 represents two of these beam segments for the first beam, while reference numeral 84 represents the two corresponding beam segments for the second beam. In similar manner, the reference numeral 86 represents the other two beam segments for the first beam (where contact is made with the reflective face 40) and reference numeral 88 represents the corresponding two segments for the second beam. When the wafer stage is in its beam symmetry position, the combination of beam segments 82 and 86 will be symmetrical with the combination of beam segments 84 and 88. The first beam exits from the beam splitter and recombiner 50 and is directed toward the reflective face 40, along the beam segment represented by reference numeral 82. In comparison, the second beam exits from the upper port of the beam splitter and recombiner and is reflected by a plane mirror 90 before reaching a penta mirror 92. Alternatively, mirror 90 is a roof mirror. The second beam is manipulated by the penta mirror to provide the initial beam path segment to the reflective face 42. The second and third beam path segments for both beams are provided by the return reflections between the reflective faces and the plane mirror 90. Finally, the fourth beam segments are coaxial with the first segments for the same beams. Consequently, the two beams are recombined and directed to the detector 52. Referring now to FIG. 6, a process flow of steps for implementing the invention in accordance with one embodiment includes the step 94 of generating first and second beams. The two beams are distinguishable with respect to either or both of frequency or polarization. It is likely that performance is maximized when the beams have different frequencies and orthogonal polarizations. The two beams may be generated using separate lasers, or the above-described techniques for beam splitting may be used. At step 96, the two beams are directed to impinge a movable apparatus, such as a wafer stage. In FIG. 2, both beams 44 and 46 are directed by the interferometer, but FIG. 5 shows an embodiment in which the second beam is directed at the movable apparatus only after reflections from a plane mirror 90 and a penta mirror 92. In step 98, beam reflections are used to establish symmetrical beam segments. In some applications, the symmetry requirement is some-what relaxed, but in such applications there can be no beam path segment that varies in length in unity with displacements of the movable apparatus along the specific axis of interest. As the movable apparatus is displaced along the specific axis, the symmetry will be affected, since the beam path segments for one beam will lengthen while the path segments for the other beam will be reduced in length. Nevertheless, the differences in lengths of individual segments will be relatively minor, so that the associated path segments remain “generally symmetrical.” The two beams are combined at step 100. Conventional techniques may be employed. Then, at step 102, position information is determined regarding the movable apparatus. As previously noted, phase detection may be used in acquiring the position information. While the illustrated embodiments of the invention utilize plane mirrors, roof mirrors and penta mirrors, other reflective components may be substituted. Moreover, other types of beam-return “mirrors” may be employed, including refractive components, diffractive components, and holographic components. One advantage of the invention results directly from the first and second reflective faces being located on a side of the movable apparatus associated with a parallel to the specific axis. In some applications of the invention, this has significant consequences. For example, in the movement of a wafer stage during fabrication processing, any remaining limitations on design are imposed by non-measurement related factors. The optical members that cooperate with the reflective faces remain beyond the ranges of the wafer stage as it is moved in directions perpendicular to the exposure axis. Thus, the optical members do not interfere with other considerations. In lithography and other possible optical applications, air showers are provided for purposes such as cooling and reducing the risk of contamination by settling particles. Uniformity of the air shower can be important, since disruptions in the air shower can cause fluctuations in the index of refraction of air. These fluctuations in the index can in turn cause fluctuations in the optical phase measured by a laser interferometer, leading to interferometer measurement error. It is believed that another advantage of the present invention is that, as compared to prior art techniques for acquiring the desired position information, the likelihood of a uniform air shower is increased. One prior art approach to determining movement of a wafer stage includes a stage mirror that is at a forty-five degree angle to the incoming laser beam (FIG. 1). A concern is that as the stage rotates, the alignment of the beam polarization to the s and p directions of the beam/mirror interface degrades, resulting in polarization rotation. In comparison, the embodiments of FIGS. 2, 3, 4 and 5 use stage reflective faces that are near normal to the incoming radiation, thereby minimizing the effects of polarization rotation. Yet another advantage of the invention is that the dynamic range is improved. Some prior art approaches unintentionally introduce beam shear that is different for the two beams of an interferometer. By reducing the relative beam shear between the interfering beams, the present invention improves the dynamic range. Moreover, the reduction in the relative beam shear reduces the effect of wavefront-related measurement. Any walk-off of one beam relative to the other at the detector remains well within the acceptable tolerances for applications such as displacement of a wafer stage. | <SOH> BACKGROUND ART <EOH>In various applications, it is necessary to acquire precise information regarding the position of an object. The object of interest may be fixed in position or may be a movable one. By way of example, positioning systems and measuring systems that are used in the integrated circuit fabrication industry must have a high level of accuracy. Prior to wafer dicing, an array of identical integrated circuits is formed on a semiconductor wafer by stepping the wafer relative to a system or system component, such as an image-bearing reticle. Often, both the reticle and the wafer are connected to stages which are movable. As used herein, a “wafer stage” includes both an apparatus for supporting the wafer and/or the apparatus for supporting the reticle. A typical wafer stage is movable in perpendicular X and Y directions. The wafer stage can therefore be stepped after each exposure of the wafer. For example, in the use of a reticle, a photoresist layer may be repetitively exposed onto a wafer by projecting an image of the reticle through a projection lens to one area on the wafer, stepping the wafer stage, and repeating the exposure. The wafer is scanned using the X and Y movements of the wafer stage until each integrated circuit region is properly exposed. In addition to the movements in the X and Y directions, Z axis movement is enabled. In wafer lithography, the Z axis may also be considered the exposure optical axis or the “focus” axis. The required range of motion in the Z direction is significantly less than the necessary ranges in the X and Y directions. Acquiring position information regarding movement of a wafer stage in the Z direction is somewhat more problematic than acquiring such information for X and Y movements. An approach to providing Z axis measurements is to use an encoder that employs interferometric techniques. One concern with this approach is that interferometer components must be relatively large in order to capture the diffracted orders as the stage translates through its full range, since the required diffraction angle must be relatively great in order to achieve the target accuracy. As an alternative, a standard Michelson interferometer may be used to monitor Z axis motions. However, if the measurement is performed from the projection lens side of the wafer stage, the percentage of stage real estate that is available to the wafer or reticle must be smaller (for a given size stage), since the laser light from the interferometer should not impinge the wafer or reticle. On the other hand, if the measurement is performed from the side of the stage opposite to the projection lens, the measurement system must use an intermediate reference, such as the stone below the stage. Among other potential disadvantages, this requires a separate measurement of the stone relative to the projection lens. FIG. 1 illustrates another approach to acquiring position information of a wafer stage 10 along a Z axis. This approach is described in detail in U.S. Pat. No. 6,208,407 to Loopstra. A wafer 12 is shown as being supported on the stage for exposure by projection optics or exposure tool 14 . The advantage of this approach is that although the interferometer 16 is positioned at the side of the stage 10 , accurate Z axis measurements may be obtained. This is enabled by properly positioning mirrors which establish a Z measuring axis 18 that is parallel to the Z axis 20 of the exposure system. A first mirror 22 is arranged at a forty-five degree angle to movement of the stage 10 along the X or Y direction. A measuring beam 24 from the interferometer impinges the forty-five degree mirror to establish the Z measuring axis 18 . A horizontal mirror 26 is attached to structure 28 of the exposure system, so that the beam is redirected to the first mirror 22 , which reflects the returned beam to the interferometer 16 . In addition to the measuring beam 24 , the interferometer projects a test beam 30 for reflection from a vertical surface 31 of the stage 10 . As can be seen in FIG. 1 , movement of the wafer stage 10 along the Z axis 20 will result in a change in the length of the beam path segment from the forty-five degree mirror 22 to the horizontal mirror 26 . Thus, while the interferometer 16 is located at the side of the stage, the measuring beam 24 has a path segment that varies in length in unity with Z axis displacements of the stage. In fact, the reflection from the horizontal mirror 26 to the forty-five degree mirror provides a second beam path segment that varies in unity with Z axis movement of the stage. On the other hand, the length of each beam path segment for the test beam 30 is fixed, unless the stage 10 is moved in the X direction. While the approach described with reference to FIG. 1 operates well for its intended purposes, there are cost concerns, since the horizontal mirror 26 is a relatively large reflective component that requires a high degree of planarity. Moreover, as the linewidths of the features of integrated circuits decrease, the size of the projection lens of the projection optics 14 increases. In FIG. 1 , this would result in an increase of the diameter of the projection optics. As a consequence, the requirement of a horizontal mirror 26 to accommodate the entire range of motion of the stage imposes a potential difficulty with respect to achieving further reductions of linewidths. For systems in which the increase in size of a projection lens is not an issue, there may be other reasons for avoiding the use of a horizontal mirror of a similar type and orientation of FIG. 1 . | <SOH> SUMMARY OF THE INVENTION <EOH>A system for acquiring position information of a movable apparatus relevant to a specific axis is achieved without requiring either an interferometer or its beam-steering members to be located in a position that would affect performance or design flexibility of the overall system in which the movable apparatus is a component. For example, where the movable apparatus is a wafer stage and the specific axis is the vertical Z axis, the beam-steering members of the system for acquiring position information are neither directly above nor directly below the wafer stage. In accordance with one embodiment of the invention, the system includes a movable apparatus having first and second reflective faces, an interferometer positioned to direct beams for impingement of the reflective faces, and beam-steering members located with respect to the interferometer and reflective faces to manipulate the reflected beams to reach a beam combiner without requiring a beam path segment that varies in length in unity with displacements of the movable apparatus along the axis. The movable apparatus may be a “wafer stage” on which a wafer or reticle is mounted for movement between steps of integrated circuit fabrication. In this application, the “specific axis” is the Z axis (i.e., the lithography optical axis) and the reflective faces are on the side of the wafer stage associated with a parallel to the Z axis. However, the first and second reflective faces are non-parallel to the Z axis itself. In order to control “walk-off” of the first beam relative to the second beam upon reaching the beam combiner, the angles of the first and second reflective faces and the positions and angles of the beam-steering members are preferably selected such that the two beam paths vary in opposition when the movable apparatus is displaced along the axis for which the position information is being acquired. The interferometer may be configured to direct the first and second beams at a generally perpendicular angle with respect to displacement of the movable member along the specific axis, with the first and second reflective faces being oppositely sloped as measured with respect to the perpendicular angle. The beam-steering members may include first and second beam-return mirrors that are respectively located in alignment with the first and second reflective faces to cause the beams to retrace (e.g., plane mirrors) or to parallel (e.g., roof mirrors) their original beam path segments in returning to the interferometer. In accordance with the method of utilizing the interferometric system to acquire the position information, the first and second beams are generated and directed toward the movable apparatus. As previously noted, the beams may both be at ninety degrees to the specific axis. The two beams are manipulated via reflections such that each beam path segment in which the beam either impinges or is reflected by the movable apparatus is symmetrical to a corresponding beam path segment for the other beam, if the movable member is in its beam symmetry position along the specific axis. However, as the movable apparatus is displaced from its beam symmetry position, at least some of the beam path segments will be changed in length, thereby providing the basis for interferometrically determining the position information. The two beams have different optical characteristics (e.g., frequency and/or polarization), allowing the employment of standard interferometric techniques. The system and method enable all optical members that are mounted to a wafer stage to remain beyond the ranges of the wafer stage movements in the X and Y directions, even if the wafer stage is considered to move beyond its possible range of motion in the Z direction. Consequently, the locations of the optical members are unlikely to affect design considerations of other aspects of the overall system in which the invention resides. | 20040220 | 20061031 | 20050825 | 73557.0 | 0 | LYONS, MICHAEL A | SYSTEM AND METHOD OF USING A SIDE-MOUNTED INTERFEROMETER TO ACQUIRE POSITION INFORMATION | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,783,243 | ACCEPTED | Rekeyable lock assembly | A rekeyable lock cylinder includes a cylinder body with a plug body and carrier sub-assembly disposed therein. The plug body includes a plurality of spring-loaded pins and the carrier assembly includes a plurality of racks for engaging the pins to operate the lock cylinder. The racks and pins move in a transverse direction, in response to insertion of a first valid key into the lock cylinder, to unlock the lock cylinder. The carrier moves in a longitudinal direction, in response to insertion of a tool in a tool-receiving aperture, from an operating position to a rekeying position. In the rekeying position, the racks are disengaged from the pins and a second valid key can replace the first valid key. Rotation of the plug body from the rekeying position with the second valid key in the lock cylinder obsoletes the first valid key. | 1. A rekeyable lock cylinder comprising: a cylinder body with a longitudinal axis; a plurality of pins disposed in the cylinder body; and a carrier sub-assembly disposed in the cylinder body and including a plurality of racks for engaging the pins, the carrier sub-assembly being moveable parallel to the longitudinal axis of the cylinder body between a first position and a second position to disengage the racks from the pins. 2. The lock cylinder of claim 1 further comprising a plug assembly having a plurality of pins, the carrier sub-assembly further including a plurality of racks for engaging the pins. 3. The lock cylinder of claim 1 wherein the racks disengage from the pins in response to movement of the carrier from the first position to the second position and engage the pins in response to movement of the carrier from the second position to the first position, the lock cylinder being in a rekeyable condition when the carrier is in the second position. 4. The lock cylinder of claim 1 wherein each pin includes at least one gear tooth. 5. The lock cylinder of claim 1 wherein the pin includes a hollow cup-shaped body. 6. The lock cylinder of claim 1 further comprising a plurality of springs, the plurality of springs having a non-constant diameter. 7. The lock cylinder of claim 6 wherein the pins are cup-shaped and configured to receive the plurality of springs. 8. The lock cylinder of claim 1 further comprising a spring catch for retaining the carrier in the second position. 9. The lock cylinder of claim 8 wherein the spring catch includes a U-shaped center portion and a pair of arms extending from the center portion. 10. The lock cylinder of claim 9 wherein the carrier sub-assembly further includes a spring-catch recess, the recess including a guide configured to receive the U-shaped center portion of the spring catch and a pair of anchors configured to engage the pair of arms. 11. The lock cylinder of claim 8 wherein the cylinder body includes a groove for receiving the spring catch when the carrier sub-assembly is in the second position. 12. The lock cylinder of claim 8 wherein the spring catch moves from an engaging position, wherein the spring catch retains the carrier sub-assembly in the second position, to a disengaged position in response to rotation of the carrier sub-assembly in the cylinder housing. 13. The lock cylinder of claim 1 wherein each rack includes at least one locking bar-receiving groove and a plurality of pin-engaging gear teeth and each pin includes at least one gear tooth for engaging the rack between two of the plurality of pin-engaging gear teeth. 14. The lock cylinder of claim 1 wherein the carrier sub-assembly further includes a carrier having a plurality of rack-receiving slots and a locking bar recess. 15. A rekeyable lock cylinder comprising: a cylinder body with a longitudinal axis; a plurality of racks selectively engageable with a plurality of pins; and means for changing the lock cylinder between a rekeying condition and an operating condition, the means for changing being moveable parallel to the longitudinal axis of the cylinder body to disengage the racks from the pins. 16. The lock cylinder of claim 15 wherein the means for changing includes means for preventing rotational movement of the racks and pins about the longitudinal axis. 17. The lock cylinder of claim 16 wherein the means for preventing includes means for locking the plug assembly against rotation in the cylinder body. 18. The lock cylinder of claim 15 wherein the means for changing includes a carrier movable between a first position and a second position and means for biasing the carrier toward the first position. 19. The lock cylinder of claim 18 further comprising a plug assembly including a carrier configured to engage the plurality of racks, the racks being engaged with the pins when the carrier is in the first position and disengaged from the pins when the carrier is in the second position. 20. The lock cylinder of claim 15 wherein the means for changing includes means for engaging the cylinder body to retain the carrier in the second position. 21. The lock cylinder of claim 20 wherein the means for engaging is configured to disengage from the cylinder body in response to rotation of the plug assembly in the cylinder body. 22. A rekeyable lock cylinder comprising: a cylinder body with a longitudinal axis; a plurality of pins disposed in the cylinder body; and a plurality of racks for engaging the plurality of pins, the racks being disposed in the cylinder body for movement parallel to, transversely to, and rotationally about the longitudinal axis of the cylinder body. 23. The lock cylinder of claim 22 further including a plug body having a locking bar movable between a locked position and an unlocked position, wherein the plug body is rotatable in the cylinder body to a rekeying position when the locking bar is in the unlocking position and the racks can be disengaged from the pins in the rekeying position. 24. The lock cylinder of claim 22 wherein each pin includes at least one gear tooth for engaging one of the plurality of racks. 25. The lock cylinder of claim 24 further including a biasing spring disposed against each of the plurality of pins, each biasing spring having a non-constant diameter. 26. The lock cylinder of claim 25 wherein each of the plurality of pins includes a cup-shaped body for receiving the biasing spring. 27. A rekeyable lock cylinder comprising: a plug body having a longitudinal axis and a plurality of pins; and a plurality of racks disposed to engage the pins, the racks being moveable transversely to the longitudinal axis and parallel to the longitudinal axis. 28. The lock cylinder of claim 27 further comprising a carrier having a plurality of slots for receiving the racks, the carrier being movable longitudinally between a first position and a second position, the racks being engaged with the pins in the first position and disengaged from the pins in the second position. 29. The lock cylinder of claim 28 wherein the carrier is rotated about the longitudinal axis from a home position to the first position and longitudinally from the first position to the second position. 30-41. Cancel 42. A rekeyable lock cylinder comprising: a cylinder body with a longitudinal axis; a plurality of pins; and a plurality of racks for engaging the plurality of pins, the racks being movable longitudinally to disengage from the pins. 43. The lock cylinder of claim 42 further including a carrier configured to carry the plurality of racks and a plug face having a keyway and a rekeying tool-receiving aperture, the carrier being movable parallel to the longitudinal axis in response to insertion of a rekeying tool into the rekeying tool-receiving aperture. 44. The lock cylinder of claim 43 further including a locking bar movable between a locking position and an unlocking position, wherein the carrier is rotatable in the cylinder body to a rekeying position when the locking bar is in an unlocking position and is movable longitudinally when the plug body is in the rekeying position. 45. The lock cylinder of claim 42 wherein each pin includes at least one gear tooth for engaging one of the plurality of racks. 46. The lock cylinder of claim 42 further including a biasing spring disposed against each of the plurality of pins, each biasing spring having a non-constant diameter. 47. The lock cylinder of claim 46 wherein each of the plurality of pins includes a cup-shaped body for receiving the biasing spring. 48. A rekeyable lock cylinder comprising: a cylinder body with a longitudinal axis; a plug body disposed in the cylinder body and having a face with a keyway and a tool-receiving aperture; a carrier disposed in the plug body; and a first valid key configured to be received in the keyway, the plug body being rotatable between a first position and a rekeying position when the first valid key is disposed in the keyway, the carrier moving longitudinally in response to the insertion of a rekeying tool into the tool-receiving aperture, the first valid key being removable from the plug body after the tool is inserted in the tool-receiving aperture. | This application is a divisional of U.S. application Ser. No. 10/256,06, filed Sep. 26, 2002. The classification of the claims contained in this application is class 70, subclass 492. The status of Parent application Ser. No. 10/256,066 is currently pending, and the location is Group Art Unit 3676, assigned to Examiner Lloyd Gall. The present invention relates generally to lock cylinders and particularly to lock cylinders that can be rekeyed. More particularly, the invention relates to lock cylinders that can be rekeyed without the use of a master key. BACKGROUND OF THE INVENTION When rekeying a cylinder using a traditional cylinder design, the user is required to remove the cylinder plug from the cylinder body and replace the appropriate pins so that a new key can be used to unlock the cylinder. This typically requires the user to remove the cylinder mechanism from the lockset and then disassemble the cylinder to some degree to remove the plug and replace the pins. This requires a working knowledge of the lockset and cylinder mechanism and is usually only performed by locksmiths or trained professionals. Additionally, the process usually employs special tools and requires the user to have access to pinning kits to interchange pins and replace components that can get lost or damaged in the rekeying process. Finally, professionals using appropriate tools can easily pick traditional cylinders. The present invention overcomes these and other disadvantages of conventional lock cylinders. The lock cylinder of the present invention operates in a transparent way that presents the familiar experience of inserting a key and rotating the key in the lock cylinder, as with current cylinders. However, in the present invention, that same familiar experience is used to rekey the lock cylinder. Thus, the user does not require any special knowledge, training, or tools to rekey the lock cylinder of the present invention. SUMMARY OF THE INVENTION The present invention provides a simple means for “teaching” a lock cylinder a new key while obsoleting old keys. According to the present invention, a rekeyable lock cylinder comprises a cylinder body with a longitudinal axis and a plug assembly disposed in the cylinder body. The plug assembly includes a plug body and a carrier sub-assembly disposed adjacent the plug body. The plug assembly further includes a plurality of pins. The carrier sub-assembly is moveable parallel to the longitudinal axis of the cylinder body and includes a plurality of racks for engaging the pins. The racks disengage from the pins in response to movement of the carrier in a first direction and engage the pins in response to movement of the carrier in a second direction. The lock cylinder is in a rekeyable condition when the racks are disengaged from the pins. The present invention further includes a novel method of rekeying a rekeyable lock cylinder. According to the invention, a method of rekeying a rekeyable lock cylinder comprises the steps of providing a lock cylinder with a plug body and a lock face having a keyway and a tool-receiving aperture, inserting a first valid key in the keyway, rotating the plug body to a first position, inserting a tool in the tool-receiving aperture, removing the first valid key from the keyway, inserting a second valid key in the keyway, and rotating the plug body away from the first position. The step of inserting the tool includes the step of moving a rack out of engagement with a pin. According to one aspect of the invention, the lock cylinder includes a carrier that is moveable parallel to a longitudinal axis of the lock cylinder and the step of inserting the tool includes the step of moving the carrier. Other features and advantages will become apparent from the following description when viewed in accordance with the accompanying drawings and appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a lock cylinder according to the present invention. FIG. 2 is an exploded view of the lock cylinder of FIG. 1. FIG. 3 is a perspective view of a plug assembly illustrating a carrier sub-assembly with a locking bar disposed in a locking position to lock the plug assembly in a lock cylinder body. FIG. 4 is a top plan view of the plug assembly of FIG. 3. FIG. 5 is a partially broken away side view of the plug assembly of FIG. 3. FIG. 6 is a partially exploded view of the plug assembly of FIG. 3. FIG. 7 is a section view through the plug assembly of FIG. 3 and a cylinder body, the section being taken transversely at one of the pins and illustrating the positioning of the pin, a rack, and the locking bar relative to each other and the cylinder body in a locked configuration. FIG. 8 is a perspective view of the plug assembly of FIG. 3 with a valid key inserted therein and illustrating the locking bar disposed in an unlocking position to allow the plug assembly to rotate in the lock cylinder body. FIG. 9 is a top plan view of the plug assembly of FIG. 8. FIG. 10 is a partially broken away side view of the plug assembly of FIG. 8. FIG. 11 is a partially exploded view of the plug assembly of FIG. 8. FIG. 12 is a section view through the plug assembly of FIG. 8 and a cylinder body, the section being taken transversely at one of the pins and illustrating the positioning of the pin, the rack, and the locking bar relative to each other and the cylinder body in an unlocked configuration. FIG. 13 is a perspective view similar to FIG. 8 but with the carrier assembly moved axially to a rekeying position. FIG. 14 is a top plan view of the plug assembly of FIG. 13. FIGS. 15a-15e are various views of a cylinder body for use in the present invention. FIGS. 16a-16f are various views of the cylinder plug body for use in the present invention. FIGS. 17a-17f are various view of the carrier for use in the present invention. FIGS. 18a-18b are views of a rack for use in the present invention. FIGS. 19a-19b are views of a spring catch for use in the present invention. FIGS. 20a-20b are views of a pin for use in the present invention. FIGS. 21a-21b are views of a locking bar for use in the present invention. FIGS. 22a-22d are views of a spring retaining cap for use in the present invention. FIG. 23 is an exploded perspective view of an alternative embodiment of the invention. FIGS. 24a-24e are views of an alternative embodiment of the lock cylinder housing. FIG. 25 is a transverse section view taken through an alternative embodiment of the present invention. FIGS. 26a-26b are views of an alternative embodiment of the spring catch. FIGS. 27a-27eb are views of an alternative embodiment of the carrier. FIGS. 28a-28b are views of an alternative embodiment of the pin. FIGS. 29a-29b are views of an alternative embodiment of the rack. FIGS. 30a-30b are views of an alternative embodiment of the locking bar. DETAILED DESCRIPTION OF THE DRAWINGS A lock cylinder 10 according to the present invention is illustrated in FIG. 1-2. The lock cylinder 10 includes a longitudinal axis 11, a lock cylinder body 12, a plug assembly 14 and a retainer 16. In FIG. 1, the plug assembly 14 is in the home position relative to the cylinder body 12. The lock cylinder body 12, as seen in FIGS. 15a-15e, includes a generally cylindrical body 20 having a front end 22, a back end 24 and a cylinder wall 26 defining an interior surface 28. The cylinder wall 26 includes an interior, locking bar-engaging groove 29 and a pair of detent recesses 30, 32. The generally V-shaped locking bar-engaging groove 29 extends longitudinally along a portion of the cylinder body 12 from the front end 22. The first detent recess 30 is disposed at the back end 24 and extends to a first depth. The second detent recess 32 is disposed adjacent the first detent recess 30 and extends to a lesser depth. A detent bore 34 extends radially through the cylinder wall 26 for receiving a detent ball 36 (FIG. 2). The plug assembly 14 includes a plug body 40, a carrier sub-assembly 42 and a plurality of spring-loaded pins 38 (FIGS. 2 and 20a-20b). The plug body 40, illustrated in FIGS. 16a-16f, includes a plug face 44, an intermediate portion 46 and a drive portion 50. The plug face 44 defines a keyway opening 52, a rekeying tool opening 54 and a pair of channels 56 extending radially outwardly for receiving anti-drilling ball bearings 60 (FIG. 2). The drive portion 50 includes an annular wall 62 with a pair of opposed projections 64 extending radially inwardly to drive a spindle or torque blade (neither shown). The drive portion 50 further includes a pair of slots 66 formed in its perimeter for receiving the retainer 16 to retain the plug body 40 in the cylinder body12. The intermediate portion 46 includes a main portion 70 formed as a cylinder section and having a first longitudinal planar surface 72 and a plurality of channels 74 for receiving the spring-loaded pins 38. The channels 74 extend transversely to the longitudinal axis of the plug body 40 and parallel to the planar surface 72. A second planar surface 76 extends perpendicular to the first planar surface 72 and defines a recess 80 for receiving a retaining cap 82 (FIGS. 2 and 22a-22d). The channels 74 extend from the second planar surface 76 partially through the plug body 40, with the sidewalls of the channels open to the first planar surface 72. The first planar surface 72 further includes a plurality of bullet-shaped, rack-engaging features 78. A bore 86 for receiving a spring-loaded detent ball 36 (FIG. 2) extends radially inwardly from opposite the first planar surface 72. The carrier sub-assembly 42 (FIGS. 2, 6 and 10) includes a carrier 90 (FIGS. 17a-17e), a plurality of racks 92 (FIGS. 18a-18b), a spring catch 96 (FIGS. 19a-19b), a spring-loaded locking bar 94 (FIGS. 21a-21b), and a return spring 98 (FIG. 2). The carrier 90 includes a body 100 in the form of a cylinder section that is complementary to the main portion 70 of the plug body 40, such that the carrier 90 and the main portion 70 combine to form a cylinder that fits inside the lock cylinder body 12. The carrier 90 includes a curved surface 102 and a flat surface 104. The curved surface102 includes a locking bar recess 106 and a spring catch recess 108. The locking bar recess 106 further includes a pair of return spring-receiving bores 109 (FIG. 17c) for receiving the locking bar return springs. The flat surface 104 includes a plurality of parallel rack-receiving slots 102 extending perpendicular to the longitudinal axis of the carrier. A semi-circular groove 111 extends along the flat surface 104 parallel to the longitudinal axis of the carrier 90. The back end of the carrier 90 includes a recess 112 for receiving the return spring 98. Each spring-loaded pin 38 includes a pin 113 and a biasing spring 115. The pins 113, illustrated in FIGS. 20a-20b, are generally cylindrical with annular gear teeth 114 and a central longitudinal bore 116 for receiving biasing springs 115 (FIG. 2). The racks 92, illustrated in FIGS. 18a-18b, include a pin-engaging surface 118 having a plurality of gear teeth 122 configured to engage the annular gear teeth 114 on the pins 113, as illustrated in FIGS. 7 and 12, and a semi-circular recess 124 for engaging the bullet-shaped, rack-engaging features 78 on the planar surface 72, as illustrated in FIG. 12. The racks 92 further include a second surface 126 that includes a plurality of anti-pick grooves 128 and a pair of locking bar-engaging grooves 132. The spring-loaded locking bar 94, illustrated in FIGS. 21a-22b, is sized and configured to fit in the locking bar recess 106 in the carrier 90 and includes a triangular edge 134 configured to fit in the V-shaped locking bar-engaging groove 29. Opposite the triangular edge 134, the locking bar 94 includes a pair of longitudinally extending gear teeth 136 configured to engage the locking bar-engaging grooves 132 formed in the racks 92, as illustrated in FIG. 12. The spring-retaining cap 82, illustrated in FIGS. 22a-22d, includes a curvilinear portion 140 having an upper surface 142 and a lower surface 144. The thickness of the curvilinear portion 140 is set to allow the curvilinear portion 140 to fit in the recess 80 with the upper surface 142 flush with the intermediate portion 46 of the plug body 40, as illustrated in FIGS. 7 and 12. A plurality of spring alignment tips 146 extend from the lower surface 144 to engage the springs 148. In addition, a pair of cap retaining tips 152 extend from the lower surface 144 to engage alignment openings 154 formed in the plug body 40 (FIGS. 16e-16f). To assemble the lock cylinder 10, the pins 113 and spring 115 are disposed in the channels 74 of the plug body 40. The spring-retaining cap 82 is placed in the recess 80, with the cap retaining tips 152 disposed in the alignment openings 154 and the spring alignment tips 146 engaged with the springs 115. The carrier sub-assembly 42 is assembled by placing the racks 92 into the slots 102 and the spring-loaded locking bar 94 into the locking bar recess 106, with the gear teeth 136 engaging the locking bar-engaging grooves 132 formed in the racks 92. The spring catch 96 is disposed in the spring catch recess 108 of the carrier 90. A valid key 160 is inserted into the keyway 52, the return spring 98 is compressed into the return spring recess 112, and the carrier sub-assembly is placed adjacent the plug body 40, as illustrated in FIG. 3. The plug assembly 14 is placed in the lock cylinder body 12 and the retainer 16 is disposed in the slots 66 formed in the plug body 40 to retain the plug assembly 14 in the cylinder body 12. The lock cylinder 10 is now keyed to the valid key 160. The properly keyed lock cylinder 10, without the key 160 inserted, is illustrated in FIGS. 4-7. The pins 113 are biased to the bottom of the channels 74 and, based on the cut of the key 160, the racks 92 are disposed at various positions in the slots 102 of the carrier 90. In this configuration, the locking bar 94 extends from the carrier 90 to engage the groove 29 in the cylinder body 12 to prevent the plug assembly 14 from rotating in the cylinder body 12 and the racks 92 engage the pins 113, as illustrated in FIG. 4. In addition, the bullet-shaped features 78 are misaligned with the recesses 111 in the racks 92 and therefore interfere with movement of the racks 92 parallel to the longitudinal axis of the lock cylinder 10, preventing the lock cylinder 10 from being rekeyed. The internal configuration of a lock cylinder 10 with the valid key 160 inserted therein at the home position is illustrated in FIGS. 8-12. In this configuration, the locking bar 94 is free to cam out of the groove 29 in the cylinder body 12, as depicted in FIGS. 8, 9 and 12. The bits of the key 160 lift the pins 113 in the channels 74 and thereby re-position the racks 92 in the slots 102. When repositioned, the racks 92 are disposed to align the locking bar-engaging grooves 132 with the extended gear teeth 136 on the locking bar 94. The locking bar 94 is free to cam out of the groove 29 as the key 160 is rotated. At the same time, the bullet-shaped features 78 are aligned with the recesses 111 in the racks 92, as illustrated in FIG. 12, allowing the racks 92, and the carrier 90, to move parallel to the longitudinal axis of the lock cylinder 10. To rekey the lock cylinder 10, the valid key 160 is inserted into the keyway 52, as illustrated in FIGS. 13-14 and rotated approximately 45° counterclockwise from the home position until the spring catch 96 moves into the second detent recess 32 formed in the cylinder body 12. A paperclip or other pointed device 162 is inserted into the tool opening 54 and pushed against the carrier 90 to move the carrier 90 parallel to the longitudinal axis of the lock cylinder 10 until the spring catch 96 moves into the first detent recess 30, and the pointed device 162 is removed. With the spring catch 96 disposed in the first detent recess 30, the racks 92 are disengaged from the pins 113, as illustrated in FIG. 14. The valid key 160 is removed and a second valid key is inserted and rotated clockwise to release the spring catch 96. As the spring catch 96 leaves the first detent recess 30, the carrier 90 is biased toward the plug face 44 by the return spring 98, causing the racks 92 to re-engage the pins 113. At this point, the lock cylinder 10 is keyed to the second valid key and the first valid key 160 no longer operates the lock cylinder 10. The lock cylinder 10 can be rekeyed to fit a third valid key by replacing the first and second valid keys in the above procedures with the second and third valid keys, respectively. An alternative embodiment 210 of the invention is illustrated in FIGS. 23-29. The alternative embodiment includes the same components, as illustrated in FIG. 23, but several of the components have been modified. Functionally, both embodiments are the same. The modified housing 212, illustrated in FIGS. 23 and 24, includes a plurality of apertures 214 running longitudinally along the bottom thereof and a pair of vertical grooves 216, 218 formed in the housing sidewall. In addition, the sidewall includes a removable side panel 220. The rectangular holes 214 are positioned to allow the use of a manual override tool. The center groove 216 includes an aperture 222 extending through the housing sidewall. The aperture 222 allows a user to move the locking bar during a manual override operation. The side panel 220 provides access for performing certain operations while changing the master key of the lock cylinder. The modified pin biasing springs 226, illustrated in FIGS. 23 and 25, include a non-constant diameter, with the last few coils at each end of the springs 226 having a reduced diameter. The tapering allows for a greater spring force in a smaller physical height. The modified spring catch 228, illustrated in FIGS. 23 and 26, includes a central U-shaped portion 230 and a pair of arms 232 extending from the U-shaped portion 230. The modified carrier 236, illustrated in FIGS. 23 and 27, includes means for retaining the spring catch 228 in the spring catch recess 238. In the illustrated embodiment, this includes a guide 240 projecting outwardly in the center of the spring catch recess 238 and a pair of anchors 242 radially offset from the guide 240. The guide 240 prevents the spring catch 228 from moving transversely in the recess 238 while permitting it to move radially outwardly to engage the housing 12, 212 as described above. The anchors 242 engage the arms 232 of the spring catch 228 and prevent the arms 232 from splaying outwardly, thereby directing the compressive force of the spring catch 228 to extend the U-shaped portion 230 outwardly to engage the housing 12, 212. The modified pins 244, illustrated in FIGS. 23 and 28, include a single gear tooth 246 instead of the plurality of gear teeth of the pins 113 described above. The single gear tooth 246, which preferably includes beveled sides 248, provides for a smoother engagement with the racks during the rekeying process. The modified racks 250, illustrated in FIGS. 23 and 29, include beveled gear teeth to improve the engagement with the pins during the rekeying process. In addition, the pair of locking bar-engaging grooves 132 in the racks 92 are replaced with a single locking bar-engaging groove 251. The modified locking bar 252, illustrated in FIGS. 23 and 30, is thinner than locking bar 94 and replaces the pair of gear teeth 136 with a single gear tooth 256 and rounds out the triangular edge 134. The thinner design reduces any rocking of the locking bar 252 in the locking bar recess 106. The above-described embodiments, of course, are not to be construed as limiting the breadth of the present invention. Modifications and other alternative constructions will be apparent that are within the spirit and scope of the invention as defined in the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>When rekeying a cylinder using a traditional cylinder design, the user is required to remove the cylinder plug from the cylinder body and replace the appropriate pins so that a new key can be used to unlock the cylinder. This typically requires the user to remove the cylinder mechanism from the lockset and then disassemble the cylinder to some degree to remove the plug and replace the pins. This requires a working knowledge of the lockset and cylinder mechanism and is usually only performed by locksmiths or trained professionals. Additionally, the process usually employs special tools and requires the user to have access to pinning kits to interchange pins and replace components that can get lost or damaged in the rekeying process. Finally, professionals using appropriate tools can easily pick traditional cylinders. The present invention overcomes these and other disadvantages of conventional lock cylinders. The lock cylinder of the present invention operates in a transparent way that presents the familiar experience of inserting a key and rotating the key in the lock cylinder, as with current cylinders. However, in the present invention, that same familiar experience is used to rekey the lock cylinder. Thus, the user does not require any special knowledge, training, or tools to rekey the lock cylinder of the present invention. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides a simple means for “teaching” a lock cylinder a new key while obsoleting old keys. According to the present invention, a rekeyable lock cylinder comprises a cylinder body with a longitudinal axis and a plug assembly disposed in the cylinder body. The plug assembly includes a plug body and a carrier sub-assembly disposed adjacent the plug body. The plug assembly further includes a plurality of pins. The carrier sub-assembly is moveable parallel to the longitudinal axis of the cylinder body and includes a plurality of racks for engaging the pins. The racks disengage from the pins in response to movement of the carrier in a first direction and engage the pins in response to movement of the carrier in a second direction. The lock cylinder is in a rekeyable condition when the racks are disengaged from the pins. The present invention further includes a novel method of rekeying a rekeyable lock cylinder. According to the invention, a method of rekeying a rekeyable lock cylinder comprises the steps of providing a lock cylinder with a plug body and a lock face having a keyway and a tool-receiving aperture, inserting a first valid key in the keyway, rotating the plug body to a first position, inserting a tool in the tool-receiving aperture, removing the first valid key from the keyway, inserting a second valid key in the keyway, and rotating the plug body away from the first position. The step of inserting the tool includes the step of moving a rack out of engagement with a pin. According to one aspect of the invention, the lock cylinder includes a carrier that is moveable parallel to a longitudinal axis of the lock cylinder and the step of inserting the tool includes the step of moving the carrier. Other features and advantages will become apparent from the following description when viewed in accordance with the accompanying drawings and appended claims. | 20040220 | 20070508 | 20050120 | 78406.0 | 1 | GALL, LLOYD A | REKEYABLE LOCK ASSEMBLY | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,783,266 | ACCEPTED | Vehicle mounted electrical generator system | A vehicle mounted AC generator system having an AC generator mounted outside the engine/transmission compartment and connected by drive shaft with universal joints and a belt driven RPM ratio device. The ratio is set to provide accurate AC generator RPM at a preselected engine RPM. The AC generator is mechanically engageable when certain conditions are met and is disconnected when other conditions are present, including an operator emergency stop switch. | 1. A vehicle mounted AC electrical generator system, said vehicle including a prime mover and a compartment for said prime mover, said AC electrical generator system comprising: an AC electrical generator substantially positioned outside said prime mover compartment and having a mechanical power input connection for driving said AC electrical generator to produce electricity, and a rotatable connection between said power take-off output and extending to a point adjacent said AC electrical generator, and for receiving mechanical power from said prime mover and transferring said mechanical power to said AC electrical generator mechanical power input connection and a pair of pulleys and a belt for interconnecting said pulleys between said rotatable connection and the mechanical power input connection of said AC electrical generator, said device being connected to said AC electrical generator, said pulleys having diameters relative to one another to achieve said predetermined RPM ratio. 2. Apparatus as claimed in claim 1 wherein said prime mover has an auxiliary power output providing said mechanical power to said transfer device. 3. Apparatus as claimed in claim 2 wherein said auxiliary power device comprises a power take-off output providing a rotatable input. 4. (canceled) 5. (canceled) 6. Apparatus as claimed in claim 1 wherein said belt comprises a toothed belt interconnecting said pulleys. 7. Apparatus as claimed in claim 1 wherein said rotatable connection comprises a shaft having a universal joint at the output of said power take-off output and another universal joint adjacent to said AC electrical generator. 8. Apparatus as claimed in claim 3 wherein said power take-off output is selectively connectable to said prime mover. 9. Apparatus as claimed in claim 8 wherein said system further comprises a solenoid for selectively engaging and disengaging said power take-off unit. 10. Apparatus as claimed in claim 1 wherein: said vehicle has a chassis incorporating generally parallel frame rails, said apparatus further comprises a device to mount said AC electrical generator between said frame rails. 11. Apparatus as claimed in claim 10 wherein said mounting device comprises clamps for clamping said AC electrical generator to at least one of said frame rails. 12. A vehicle mounted AC electrical generator system, said vehicle including a prime mover controlled by a control system to a predetermined RPM, said AC electrical generator system comprising: an AC electrical generator positioned in said vehicle and having a mechanical power input connection for driving said AC electrical generator to produce electricity, a device receiving mechanical power from said prime mover and transferring said mechanical power to said AC electrical generator mechanical power input connection, said mechanical power device incorporating a fixed RPM ratio to match the RPM of the prime mover to the operational RPM of said AC electrical generator. 13. Apparatus as claimed in claim 12 wherein said mechanical power device incorporates a step up RPM ratio to increase the RPM from said prime mover to said AC electrical generator. 14. Apparatus as claimed in claim 13 wherein said prime mover operates at a preselected RPM and over a variable operational RPM range as dictated by said control system, and wherein said prime mover operates the transfer device when said prime mover is at said preselected RPM. 15. Apparatus as claimed in claim 12 wherein the control system for said prime mover has an electronic control module. 16. Apparatus as claimed in claim 12 wherein said prime mover has an auxiliary power output and said transfer device connects between said auxiliary power output and the mechanical power input connection of said AC electrical generator. 17. Apparatus as claimed in claim 16 wherein said transfer device comprises: a connection between the rotary output of said auxiliary power output and a point adjacent said AC electrical generator, and a means for establishing a predetermined RPM ratio between said rotatable output connection and the input connection of said AC electrical generator. 18. Apparatus as claimed in claim 17 wherein said RPM ratio device increases the RPM between said auxiliary power takeoff output and said AC electrical generator. 19. Apparatus as claimed in claim 17 wherein said AC generator operates at 3600 RPM during operation. 20. Apparatus as claimed in claim 17 wherein said AC generator operates at 3,000 RPM during operation. 21. Apparatus as claimed in claim 15 wherein said electronic control system supplies fuel to said prime mover at a rate and condition to vary the power output of said prime mover, whereby said operational RPM of said AC electrical generator is maintained substantially constant irrespective of variations on electrical loads applied to said AC electrical generator. 22. A vehicle mounted AC electrical generator system, said vehicle including a prime mover controlled by a control system, said AC electrical generator system, comprising: an AC electrical generator positioned in said vehicle and having a mechanical power input connection for driving said AC electrical generator to produce electricity, a device releasably engageable to receive mechanical power from said prime mover and transfer said mechanical power to said AC electrical generator mechanical power input connection, a device operable to engage and disengage said mechanical power transfer device from said prime mover, said engaging and disengaging device being interconnected with the control system for said prime mover to control engagement of said AC electrical generator dependent upon inputs from said control system. 23. Apparatus as claimed in claim 22 wherein said releasably engageable device comprises a power takeoff output shaft having a mechanism for releasably engaging said transfer device. 24. Apparatus as claimed in claim 23 wherein: said power takeoff output shaft has a driven gear, said prime mover has a driving gear providing a rotatable output from said prime mover and displaceable into and out of engagement with said power output shaft driven gear, and said system has a device for displacing said driving gear into and out of engagement with said driven gear. 25. Apparatus as claimed in claim 24 wherein said device for displacing said driving gear is a solenoid receiving an electrical input. 26. Apparatus as claimed in claim 25 wherein said solenoid valve biases said driving gear to a disengaged position in the absence of an electrical signal and to an engaged position in the presence of an electrical signal. 27. Apparatus as claimed in claim 26 wherein said system further comprises a device interconnecting said solenoid valve to said prime mover control system for the purpose of said power takeoff output in the event certain operating parameters are detected. 28. Apparatus as claimed in claim 22 wherein said mechanical power transfer device comprises a hydraulic drive providing a rotatable output to said AC electrical generator. 29. Apparatus as claimed in claim 22 wherein said engaging and disengaging device transfers mechanical power to said AC electrical generator when certain operating parameters exist. 30. Apparatus as claimed in claim 22 wherein said vehicle has a further control system for controlling vehicle parameters and wherein said engaging and disengaging device is also responsive to vehicle control parameters to transfer mechanical power to said AC electrical generator. 31. Apparatus as claimed in claim 30 wherein said prime mover has an engine control module, and a transmission control module and wherein said engaging and disengaging device is responsive to electrical control signals, said AC electrical generator system comprising a relay device receiving inputs from said engine control module and said transmission control module for enabling operation of said AC electrical generator when certain control parameters exist in said engine control module and said transmission control module. 32. Apparatus as claimed in claim 22 wherein said engaging and disengaging device disconnects said mechanical power to said AC generator when certain operating parameters are present. 33. Apparatus as claimed in claim 32 wherein said AC generating system has an output box for providing electrical load connection to said AC generator and wherein the operating parameter is temperature above a given level. 34. Apparatus as claimed in claim 33 further comprising an emergency operation switch to disengage the AC generator from said prime mover. 35. (canceled) 36. (canceled) 37. (canceled) 38. (canceled) 39. (canceled) 40. A method of adding an AC electrical generator operating at a predetermined RPM to a vehicle having a support frame and powered by a prime mover located in a prime mover compartment, said prime mover providing a rotary output and having an operating condition during which said prime mover operates at a preselected RPM, said method comprising the steps of: mounting said AC electrical generator outside said prime mover compartment, and in an available location in said support frame, providing a mechanical connection between said prime mover and said AC electrical generator, and providing a predetermined RPM ratio in said mechanical connection so that said AC electrical generator operates at said predetermined RPM when said prime mover operates at said preselected RPM. 41. (canceled) 42. A method as claimed in claim 40 wherein said vehicle has a control system and wherein said mechanical connection is engageable and disengageable, said method further comprising the step of integrating the operation of said AC generator with the control system of said vehicle. 43. Apparatus as claimed in claim 12 wherein said mechanical power transfer device comprises a hydraulic drive providing a rotatable output to said AC generator. 44. (canceled) 45. Apparatus as claimed in claim 28 wherein said vehicle and prime mover operate over a range of RPMs and wherein said system further comprises: a control device providing a variable RPM ratio to said hydraulic drive, and a device for sensing prime mover RPM and hydraulic drive output RPM and operating said control device to maintain said predetermined AC generator RPM irrespective of said prime mover RPM. | The present invention relates to electrical generators and more specifically to electrical generators for use in vehicles. BACKGROUND OF THE INVENTION There has been a long-felt need for an AC electrical power source in locations not served by electrical utilities. Usually these involve construction sites where the electrical power grid is not yet extended to an individual site. In addition, there are sites that are so remote that electricity is not available. Typically, AC power generated by a vehicle has been accomplished y the use of inverters which take DC voltage, step it up to well above 240 volts and then electronically manipulate the DC signal so that some form of AC signal at either 120 volts or 240 volts is provided at an outlet box. The system shown in U.S. Pat. No. 6,157,175 is typical of such systems. These involve an alternator positioned in or near the engine compartment and driven off of an accessory belt drive. The alternator generates DC voltage which is then electronically boosted and then chopped to produce a pseudo-AC wave. The problem with devices of this type is significant expense associated with the alternator itself and the complex electrical control system used to produce the pseudo-AC wave output. Furthermore, such systems are relatively incapable of sustaining maximum or above maximum output for any length of time and lack reserve capacity to achieve really heavy-duty current output as when an arc welder or other electrical power-consuming device is utilized with the system. SUMMARY The above invention relates to a vehicle-mounted AC electrical generator system where the vehicle includes a prime mover and a compartment for the prime mover. An AC electrical generator is positioned outside said prime mover compartment and has a mechanical power input connection for driving the AC electrical generator to produce electricity. The device receives mechanical power from the prime mover and transfers the mechanical power to the AC electrical generator mechanical power input connection. In another form, the invention relates to a method of adding an AC electrical generator to a vehicle having a support frame and powered by a prime mover located in a prime mover compartment. The method comprises the steps of mounting the AC electrical generator outside the prime mover compartment and in an available location in the support frame. A mechanical connection is provided between the prime mover and the AC electrical generator. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic drawing of a vehicle and an AC electrical generator system embodying the present invention. FIG. 2 is a schematic diagram of another electrical generator system for providing AC electrical generation capacity when a vehicle is stationary. FIG. 3 is a schematic diagram showing an alternate embodiment of the present invention adaptable for provision of electrical power while a vehicle is moving. FIG. 4 is a partial view of a vehicle in which the AC electrical generating system is installed looking from the front toward the aft section of the vehicle. FIG. 5 is a side fragmentary view of the vehicle of FIG. 4 taken on lines 5-5 of FIG. 4. FIG. 6 is a plan view of the system of FIG. 4 taken on lines 6-6 of FIG. 4. FIG. 7 is a greatly enlarged longitudinal fragmentary section view of a power takeoff (PTO) shown in FIG. 4 and taken on lines 7-7 of FIG. 4. FIG. 8 is an enlarged side view of an AC electrical generator mounting assembly used to support the AC generator shown in FIGS. 4 through 6. DESCRIPTION OF THE SELECTED EMBODIMENT For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated herein and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the described processes, systems or devices, and any further applications of the principles of the invention as described herein, are contemplated as would normally occur to one skilled in the art to which the invention relates. FIG. 1 shows a vehicle system 10 with which an AC electrical generating system is incorporated. The existing vehicle components and AC generator accessories are demarked by a reference line A. The vehicle 10 has a frame, not illustrated in FIG. 1, but illustrated in FIG. 4 through FIG. 8, which provides a support for a vehicle body, also not shown, and an engine 14 driving a transmission 16 through a primary mechanical output 18 to function as a prime mover for vehicle 10. Engine 14 may be any one of a variety of prime movers including spark-ignited gasoline or natural gas fueled engine or a compression ignition diesel engine. It should be apparent to those skilled in the art that other forms of prime movers providing mechanical outputs may be incorporated. The transmission 16 may be one of a variety of transmissions herein shown as an automatic transmission providing a rotatable output shaft 20 for the vehicle 10. The engine 14 is controlled by an engine control module (ECM) 22 interconnected to engine 14 at 24. The interconnection between engine control module 22 and engine 14 may vary widely according to the type of engine and the desired control parameters. In most cases, the engine fuel supply system (not shown) is controlled by a computer in the (ECM) 22 in accordance with an algorithm based on various engine operating parameters such as engine RPM, required torque, ambient temperatures, absolute pressure and a host of other variables. The result is that the interconnection between the engine control module 22 and engine 14 through 24 is a two-way connection wherein parameter signals are transmitted to the ECM and control signals are transmitted to the engine 14. In a number of vehicles, the transmission 16 has a more sophisticated control through a transmission control module 26 interconnected to transmission 16 through 28 and connected to engine control module 22 through 30. The transmission control module 26, ECM 22, engine 14 and transmission 16 are all coordinated so that the appropriate balance of required power, fuel economy and emissions level is maintained. In addition to the transmission control module 26, the vehicle 10 has an ignition switch 32 connected to ECM 22 by line 34. The vehicle 10 also has an operator's switch 36 connected to ECM 22 by line 38 for controlling the power takeoff (PTO) described later. In addition, the vehicle 10 has a cruise control resume switch 40 connected to the ECM 22 by line 42. In order to simplify the description of the present invention, the vehicle elements generally described by reference character 10 will be given the same reference characters in FIG. 2 and FIG. 3 even though the AC power generation system will have different elements cooperating with the vehicle components. The present invention consists of applying a readily available, highly commercially developed and relatively inexpensive AC generator to a vehicle instead of the overly complicated DC generators and inverters previously applied to such vehicles. The elements set forth below allow this to be achieved in a way that is consistent with heavy-duty electrical generation and convenience and safety of use. The AC generator system generally indicated by 12 comprises an AC generator 44 that can be selected from various sizes and manufacturers. Measured in kilowatt output, it has been found that 5-15 kilowatts are readily accommodated within vehicles as set out below. It should be apparent to those skilled in the art, however, that many other AC generators could be employed for this purpose. One of the advantages of an AC generator is that it produces a perfect sine wave which replicates the sine wave produced by utility companies as opposed to the modified or mock sine wave produced by standard inverters on the market. It is also a feature of AC generators that they are very robust and can easily handle high continuous current loadings as would be experienced in typical construction site activities like welding and heavy-duty cutting of materials. The AC generator 44 is positioned in the vehicle outside of the compartment for the prime mover consisting of the engine and transmission as will be described in detail later. The AC generator has a mechanical power input 46 which is adapted to receive a rotatable input from an RPM ratio assembly. Assembly 48 is connected to a PTO unit 50 via an appropriate mechanical link such as a shaft 52. PTO unit 50 is driven from transmission 16 through an engageable and disengageable mechanical connection 54. A solenoid 56 mechanically connects with PTO unit 50 through a connection 58 to engage or disengage PTO unit 50 and thus drive the AC generator 44 as will be described later. Solenoid 56 is of a type that is biased to a disengaged position in the absence of an electrical signal and then urged to an engaged position when an electrical signal is sent to solenoid 56 via line 60. Line 60 is connected to a relay box 62 which enables engagement of solenoid 56 and therefore mechanical operation of AC generator 44 only when certain conditions exist. The relay box receives input from the cruise control resume button 40 via line 64 and from ignition switch 32 via line 66. Finally, the relay box receives an input from operator switch 36 via line 68, and from ECM 22 via line 70, and from the transmission control module via line 71. The electrical output of AC generator 44 extends to output box 72 via power line 74. Output box 72 has usual electrical receptacles. In addition, output box contains an emergency stop switch 74 having a line 76 which connects with relay box 62. In addition, output box 72 has an over-temperature sensor 78 also connected to relay box 62 by means of a line 80. The AC generator system 12 disclosed above takes advantage of the fact that the ECM 22 accurately controls the RPM of engine 14 under a variety of circumstances including conditions where the engine control module maintains a preselected RPM. In certain vehicles having the capability to connect a power takeoff unit or PTO, there is a feature within the ECM 22 and transmission control module 26 known as the PTO program. The PTO program dictates the prime mover to operate at an RPM that is maintained essentially constant but at a level higher than the normal RPM of the vehicle when it is operating at normal idle. For example, if the normal idle of a vehicle is under 1,000 RPM, the PTO program controls to 1,150 RPM. The drive ratio in housing 48 is selected so that the RPM of the AC generator 44 would be at its optimum to replicate a utility sine wave. Generally speaking, the AC generator's optimum RPM is 3600 for 60 cycles AC in the U.S. and 3000 RPM for 50 cycles found outside of the U.S. Thus the RPM of the generator 44 is extremely accurately controlled by virtue of the governing aspect of the engine control module 22 which varies the quantity of fuel delivered to the engine 14 to account for variations in mechanical load when the electrical loads through output box 72 are varied. As pointed out before, relay box 62 plays a key role in enabling operation of solenoid 56 so that the AC generator system is only operated when conditions are safe. Thus the following conditions must exist before solenoid 56 can be engaged: (1) automatic transmission in park as sensed through line 71, (or if a manual transmission, in neutral with vehicle parking brake set), (2) operator switch 36 on as sensed through line 68, (3) ignition switch 32 on as sensed through line 66. When these are present, the solenoid is engaged and when the ignition switch 32 is turned to start the engine 14, the solenoid 56 engages the PTO unit 50 to drive AC generator 44. The cruise control resume switch 40 or PTO set position on the operator switch 36 is activated to place the engine 22 in the PTO program for optimum operation of the AC generator 44. The AC generator 44 supplies electrical power through the output box 72. This continues until either: (1) the operator switch 36 is turned off, (2) the ignition switch 32 is turned off, (3) the emergency switch 74 in output box 72 is activated, or (4) the over-temperature sensor 78 indicates too high a temperature through output box 72. Thus it is seen that the AC generator system efficiently utilizes existing sophisticated controls in the vehicle 10 to produce highly accurate and rugged electrical energy. It should be also noted that for vehicles having automatic transmissions with a PTO, the lock-up switch in the transmission is activated when the PTO is engaged. Accordingly, the responsiveness of the ECM to RPM variations due to load is greatly enhanced, thereby enabling an accurate regulation of RPM. It should also be noted that the mechanical input into the generator 44, while shown as coming from the PTO, may be also derived from any convenient accessory output of the engine including accessory gear boxes, accessory belt drives and the like. The system shown in FIG. 1 contemplates a mechanical connection described later between the transmission PTO unit 50 and the input to the AC generator 14. The system shown in FIG. 2 employs a hydraulic drive, generally indicated by reference character 82, which is interconnected to the vehicle 10 by a mechanical connection 84 from engine 14 to a hydraulic pump 86. It should be noted that the mechanical input from 84 may either be an accessory gear drive or belt drive or even a PTO depending upon the particular engine/transmission combination. In any event, the mechanical input 84 rotates hydraulic pump 86 to supply fluid under pressure through line 88 past adjustable flow control 90 to hydraulic motor 92 which has as its output the mechanical input 46 to the AC generator 44. A return line 94 extends to a hydraulic reservoir 96 having a feed line 98 to hydraulic pump 86. Details of the hydraulic drive 82 will not be discussed in order to aid in an understanding of the present invention. However, typical hydraulic drives may consist of a gear pump 86 having its output regulated by an adjustable flow control 80 to a gear motor 92 having an output RPM controlled by flow as regulated by flow control 80. Alternately, hydrostatic drives involve multi-piston hydraulic pumps and corresponding multi-piston hydraulic motors. The translatory movement of the pistons is translated into rotary movement by virtue of a wobble plate. Variations may come in the form of flow control or mechanical variations in the components in order to provide a predetermined RPM ratio between the output of the engine 14 and the input to the AC generator 44. As in the case with the system set forth in FIG. 1, the adjustable flow control 90 is set to produce an RPM ratio that takes into account the preselected engine RPM and the required RPM for the AC generator. The enablement features of relay box 62 are similar to those for FIG. 1 depending upon the engine transmission interconnections and controls. Still another variation in the generator control system 12 is found in FIG. 3 wherein a hydraulic drive is adapted to control the AC generator when the vehicle 10 is operated on the highway with varying RPMs from output shaft 20. In this case, a hydraulic drive 100 is connected between an output shaft 102 of the PTO 50 and the input shaft 46 to the AC generator. Hydraulic drive 100 comprises a hydraulic pump 104 driven by input shaft 102 and supplying fluid through line 106 via adjustable flow control 108 to hydraulic motor 110 which has its output connected to input shaft 46 for AC generator 44. A return line 112 extends to a hydraulic reservoir 114 and in turn has a feed pipe 116 to the hydraulic pump 104. Additionally, the hydrostatic drive 100 has a speed sensor and flow control module 118, which acts to vary the RPM ratio between the PTO unit and the drive to the AC generator. Speed sensor 118 receives engine RPM (and therefore vehicle speed) inputs via line 120 extending to relay box 62 and to the engine control module 70. The details of how this operates will not be discussed to simplify an understanding of the present invention. However, it is sufficient to say that the speed sensor and flow control module 18 varies the RPM ratio between the PTO unit and the input shaft 46 to AC generator to maintain a specific RPM from AC generator 44 as sent to the speed sensor 118 via line 122. This preselected RPM is maintained regardless of the variation in RPM of engine 14 and transmission 16. What has been described above is how the generator system of the present invention integrates with the operational control and safety system of the vehicle 10. Reference is now directed to FIGS. 4 through 8 which show a specific implementation of the system described in FIG. 1. FIGS. 4 though 8 show only those portions of the vehicle 10 necessary to properly explain the present invention. All the other details have been omitted to allow a simplification and focus on a proper understanding of the invention. Vehicle 10 has a pair of frame rails 130 and 132. The frame rails 130 and 132 are generally parallel and form the structural support for many commercial vehicles. Within the frame rails 130 and 132, the engine 14 (not shown) is mounted in such a way that its crankshaft axis identified at 134 is generally parallel to the longitudinal axis of the frame rails 130 and 132. It should also be noted, however, that the engine center line may be oriented other than as shown and still achieve the benefits of the present invention. The transmission 16 is secured to the engine so that the input face 18 to the transmission 16 is coaxial with the axis 134 of the engine. The primary power output from the engine transmission 16 is not shown in order to simplify an understanding of the present invention. It should be apparent to those skilled in the art that it will drive a differential axle at the rear of the vehicle. In addition, it may have an additional output to provide all-wheel-drive by connecting to a similar differential or drive arrangement at the front of the vehicle. As herein shown, the transmission 16 is an automatic manufactured by Allison Division of General Motors. It should be apparent that other transmission brands may be used with equivalent advantage. Transmission 16 has a power takeoff or PTO 50 which has a standard SAE 6 or 8 bolt mounting plate configuration that is equivalent for all commercially available transmissions. As shown particularly in FIG. 5, PTO 50 has a universal joint 136 at its output which connects to a torque tube 138 extending aft from vehicle compartment 140 substantially housing the prime mover consisting of the engine 14 and transmission 16. The prime mover compartment 140 is shown in solid outline in FIG. 4 and in dashed outline in FIG. 5. The torque tube 138 extends to a universal joint 142 forming the input to an RPM ratio device 48 that connects to AC generator 44. As shown particularly in FIG. 4, RPM ratio device comprises a housing 144 having journaled therein an input pulley 146 and output pulley 148. Output pulley 148 is fixed to the input 46 to AC generator 44. Input shaft 46 is a shaft and pulley 148 is secured to the shaft in normal fashion. A belt 150 extends between pulleys 146 and 148. The belt 150 is shown as a toothed belt to provide increased torque carrying capacity. It should be noted, however, that a non-toothed belt and other forms of RPM ratio manipulation may be employed with equivalent advantages. Specifically, intermeshing gears may also be employed for this application. As mentioned in the discussion of FIG. 1, the ratio between the power takeoff output RPM and the required input of AC generator 44 is selected to match the optimal RPM conditions for AC generator 44. This is done by selecting the diameters of pulleys 148 and 146 to achieve the required RPM. The PTO 50 is shown as being engageable and disengageable with the output of transmission 16. FIG. 7 shows one implementation of this feature. A housing 152 is secured to the transmission housing 154 by appropriate screws 156 (see FIG. 4). Housing 152 is positioned over a transmission PTO drive gear 158 shown in FIG. 7 and in FIG. 4. An output shaft 160 is journaled in housing 152 by appropriate bearings 162 and 164 to journal shaft 160 on an axis parallel to the axis 134 of the engine 14 and transmission 16. The end of shaft 160 extending from housing 152 connects with universal joint 136. Shaft 160 has an elongated splined section 166 on which a spur gear 168 is telescoped. Spur gear 168 has internal splines 170 which cause gear 168 to rotate with shaft 160 but permits it to be axially displaceable from the solid position shown in FIG. 7 where the AC generator is disengaged from the prime mover to the leftmost position indicated by partial lines in FIG. 7 where the AC generator is engaged with the prime mover. Spur gear 168 has an integral extension 172 and groove 174 which receives a fork 176. Fork 176 is secured to the moveable output shaft 178 of a solenoid 180. Output shaft 178 of the solenoid 180 is biased to its solid position shown in FIG. 7 by a spring 182 acting against a flange 184 on shaft 178 and an end wall 186 in solenoid 180. Solenoid 180 then holds the gear 168 in its disengaged position by virtue of the spring and when electrical power is applied to solenoid 180 by line 60, the output shaft 178 is displaced to the left as shown in FIG. 7 thus meshing gear 168 with the transmission accessory drive gear 158 to cause the AC generator to be operated. It should be noted particularly in FIG. 4 that housing 152 of PTO 50 has an angled outer configuration so as to clear the existing wall of prime mover compartment 140. This is particularly advantageous for applications where the PTO is desired to be taken off of a side of the transmission opposite to the provision made by the original equipment manufacturer. As pointed out earlier, the AC generator 44 is positioned at a point substantially outside of the prime mover compartment 140. In vehicles of this type, it is common to have frame rails. The brackets shown in FIG. 8 show in detail how the AC generator 44 and RPM ratio device 48 may be mounted in the vehicle frame without having to drill holes or otherwise cut into the structural integrity of the frame rails. As shown particularly in FIG. 8, frame rail 132 from which the AC generator 44 will be mounted has a C-shaped cross-section with lips 188 extending toward one another. The bracket for mounting the AC generator 44 and RPM ratio device 48 comprises a pair of fingers 190 extending from vertical brackets 192 and in a direction generally at right angles to the axis of rotation of AC generator 44. Brackets 192 extend vertically beyond the upper and lower extent of frame 132 and connect to plates 194 by means of fasteners 196 to sandwich the lips 188 of frame rail 132. A pair of longitudinal support plates 198 interconnect brackets 190 and provide a mounting platform for the AC generator 44. It should be noted that because the frame 132 is generally of uniform cross-section, the vertical brackets 192 and plates 194 may be easily positioned in an optimal location along frame rail 132 to provide optimum positioning of AC generator where a space is available within the frame of the vehicle 10. It should be noted that in practice the space within the frame of the vehicle is usually crowded with a significant number of components including the main drive shaft to the rear axle, the catalytic converter and muffler and appropriate interconnecting exhaust pipe. In addition, items like a fuel tank could be contained within the frame. By clamping the mounting for the AC generator in the manner described above, greater flexibility is realized to fit the AC generator 44 into an appropriate location. As shown particularly in FIG. 6, the electrical output from AC generator 44 through line 74 extends from AC generator 44 through the frame 132 to the output box 72 (not shown in FIG. 6). However it should be noted that at least a portion of the electrical line 74 extends through frame 132 for added protection as it extends to outlet box 72. Also with reference to FIG. 6, the load-carrying portion of vehicle 10 is indicated by dashed lines 200 and it is apparent that the AC generator 44 is contained within the frame adjacent the load carrying section 200. This is advantageous because the outlet box 72 is also positioned in the load carrying section making it convenient to construction equipment and supplies to be used by an operator. While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. | <SOH> BACKGROUND OF THE INVENTION <EOH>There has been a long-felt need for an AC electrical power source in locations not served by electrical utilities. Usually these involve construction sites where the electrical power grid is not yet extended to an individual site. In addition, there are sites that are so remote that electricity is not available. Typically, AC power generated by a vehicle has been accomplished y the use of inverters which take DC voltage, step it up to well above 240 volts and then electronically manipulate the DC signal so that some form of AC signal at either 120 volts or 240 volts is provided at an outlet box. The system shown in U.S. Pat. No. 6,157,175 is typical of such systems. These involve an alternator positioned in or near the engine compartment and driven off of an accessory belt drive. The alternator generates DC voltage which is then electronically boosted and then chopped to produce a pseudo-AC wave. The problem with devices of this type is significant expense associated with the alternator itself and the complex electrical control system used to produce the pseudo-AC wave output. Furthermore, such systems are relatively incapable of sustaining maximum or above maximum output for any length of time and lack reserve capacity to achieve really heavy-duty current output as when an arc welder or other electrical power-consuming device is utilized with the system. | <SOH> SUMMARY <EOH>The above invention relates to a vehicle-mounted AC electrical generator system where the vehicle includes a prime mover and a compartment for the prime mover. An AC electrical generator is positioned outside said prime mover compartment and has a mechanical power input connection for driving the AC electrical generator to produce electricity. The device receives mechanical power from the prime mover and transfers the mechanical power to the AC electrical generator mechanical power input connection. In another form, the invention relates to a method of adding an AC electrical generator to a vehicle having a support frame and powered by a prime mover located in a prime mover compartment. The method comprises the steps of mounting the AC electrical generator outside the prime mover compartment and in an available location in the support frame. A mechanical connection is provided between the prime mover and the AC electrical generator. | 20040220 | 20051227 | 20050825 | 67444.0 | 1 | PONOMARENKO, NICHOLAS | VEHICLE MOUNTED ELECTRICAL GENERATOR SYSTEM | SMALL | 0 | ACCEPTED | 2,004 |
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10,783,339 | ACCEPTED | Apparatus and method for supporting a removable anvil | A grinding machine having a mounting arrangement and an anvil. The grinding machine generally including a feed table and a grinding drum positioned within a mill box. The mounting arrangement being configured to support an end of the feed table and the anvil. The anvil including a wedge-shaped portion and having a length. The length of the anvil being configured to extend beyond sides of the mill box. | 1. A grinding machine, comprising: a) a mill box; b) a grinding drum positioned within the mill box; c) a feed table for transporting material to the mill box, the feed table defining a transport plane; and d) an anvil oriented generally parallel to the grinding drum, the anvil having a first surface and a second surface, the first and second surfaces defining a wedge-shaped portion, the anvil being oriented such that the first surface of the wedge-shaped portion is generally aligned with the transport plane of the feed table. 2. The grinding machine of claim 1, wherein the first surface is aligned with the transport plane of the feed table such that the first surface is a planar extension of the transport plane of the feed table. 3. The grinding machine of claim 1, wherein the anvil is oriented to provide an increasing clearance distance between feed table and the second surface of the anvil. 4. The grinding machine of claim 1, wherein the anvil further includes a third surface extending at an angle from the first surface. 5. The grinding machine of claim 4, wherein the first and third surface meet at an edge, the arrangement of the edge of the anvil in relation to the grinding drum defining a minimum clearance gap between the anvil and the grinding drum. 6. The grinding machine of claim 4, wherein the third surface is generally parallel to the second surface. 7. The grinding machine of claim 4, wherein the anvil has a maximum thickness defined between the third surface and the second surface. 8. The grinding machine of claim 1, wherein the anvil is made of a solid construction. 9. The grinding machine of claim 1, wherein the anvil has first and second ends, each of the first and second ends extending outside of the mill box. 10. The grinding machine of claim 9, further including a mounting arrangement having clamp arms, the clamp arms being configured to secure the first and second ends of the anvil at a location outside of the mill box. 11. The grinding machine of claim 1, further including a mounting arrangement configured to mount the anvil in relation to the feed table, the mounting arrangement including a first support surface configured to support an end of the feed table and a second support surface configured to support the anvil. 12. A grinding machine, comprising: a) a mill box having opposite sides, the opposite sides of the mill box defining a grinding width, each of the sides defining an aperture; b) a grinding drum positioned within the mill box; c) a wedge-shaped anvil located adjacent to the grinding drum, the wedge-shaped anvil being positioned within the apertures of each of the sides of the mill box, the anvil having a length greater than the grinding width of the mill box such that ends of the anvil extend beyond the sides of the mill box. 13. The grinding machine of claim 12, wherein the wedge-shaped anvil is made of a solid construction. 14. The grinding machine of claim 12, further including a mounting arrangement having clamp arms, the clamp arms being configured to secure the ends of the anvil when positioned within the apertures of each of the sides of the mill box. 15. The grinding machine of claim 12, further including a feed table for transporting material to the mill box. 16. The grinding machine of claim 15, further including a mounting arrangement, the mounting arrangement including a first support surface configured to support an end of the feed table and a second support surface configured to support the anvil. 17. The grinding machine of claim 16, wherein the second support surface is located outside of the mill box of the grinding machine. 18. A mounting arrangement for a grinding machine, the grinding machine including a grinding drum positioned within a mill box, a feed table for transporting material to the mill box, and an anvil, the mounting arrangement comprising: a) a mounting arrangement including an adaptor, the adaptor having: i) a first support surface configured to support an end of the feed table; and ii) a second support surface configured to support the anvil. 19. The mounting arrangement of claim 18, wherein the second support surface is a planar support surface, and the first support surface is an annular bearing support surface. 20. The mounting arrangement of claim 18, further including a clamp arm, the clamp arm being arranged to secure the anvil in a position relative to the second support surface of the adaptor. 21. A grinding machine, comprising: a) a mill box having opposite sides, the opposite sides of the mill box defining a grinding width, each of the sides defining an aperture; b) a grinding drum positioned within the mill box; c) an anvil located adjacent to the grinding drum, the anvil being positioned within the apertures of each of the sides of the mill box, the anvil having a length greater than the grinding width of the mill box such that ends of the anvil extend beyond the sides of the mill box; and d) a mounting arrangement configured to clamp upon the ends of the anvil that extend beyond the sides of the mill box to mount the anvil adjacent to the grinding drum when positioned within the apertures of each of the sides of the mill box. 22. The grinding machine of claim 21, wherein the anvil is wedge-shaped. 23. The grinding machine of claim 21, wherein anvil is made of a solid construction. 24. The grinding machine of claim 21, wherein the mounting arrangement includes clamp arms, the clamp arms being configured to contact the ends of the anvil when positioned within the apertures of each of the sides of the mill box. 25. The grinding machine of claim 21, further including a feed table for transporting material to the mill box. 26. The grinding machine of claim 25, wherein the mounting arrangement includes a first support surface configured to support an end of the feed table and a second support surface configured to support the anvil. 27. The grinding machine of claim 26, wherein the second support surface is located outside of the mill box of the grinding machine. | TECHNICAL FIELD This disclosure generally relates to horizontal grind machines, and more particularly, to an anvil and anvil support arrangement and apparatus. BACKGROUND The grinding of a variety of materials can have a desirable effect. For instance, grinding of some types of waste results in increased rate of decomposition, which is useful in landfill operations; grinding wood waste produces mulch that is useful in landscaping applications; and grinding asphalt is useful in recycling efforts. Some types of shingles can also be ground for use in asphalt production. The benefits of and need for such recycling processes continue to grow. Several types of machines are used in grinding applications. One type is known as a horizontal grinder. An example of a horizontal grinder is disclosed in U.S. Pat. No. 5,881,959. Horizontal grinders typically include a horizontal feed table onto which material to be ground is placed. The feed table is capable of moving the material to a point where a feed roller begins to cooperate with the feed table. The feed roller generally presses down on top of the material, while being rotationally powered, to assist in forcing the material into contact with the side of a grinding drum. The grinding drum is as wide as the feed table and rotationally powered on a generally horizontal axis perpendicular to the direction of travel of the feed table. The grinding drum typically includes hammers or cutters mounted to the outer perimeter of the drum to impact the material as it is fed from the feed roller/feed table. These hammers or cutters tend to propel the material either up, for grinders known as up-cut grinders, or down, for grinders known as down-cut grinders. Down-cut grinders force the material past a stationary bar, typically known as an anvil, which is in relatively close proximity to the outer swing diameter of the hammers or cutters. Because of the anvil's relative close proximity, the size of the outer swing diameter is reduced, as necessary, to travel past the anvil. Once the material passes the anvil, the material is further reduced, as necessary, to pass through a screen. In the '959 patent, a primary anvil is positioned a slight distance from the grinding drum such that a primary grind will occur as the material is forced past the primary anvil. The material is further reduced at a secondary anvil. If the material is ungrindable, the material passes through a trap door positioned between the primary and secondary anvils. This arrangement involves several components and moving parts that add complexity to the overall design of the grinder. An alternative design, marketed by Vermeer Mfg (Model HG525) includes a single anvil that is located in close proximity to the grinding drum such that any material that passes by this single anvil, is capable of passing through the screens. Ungrindable material is typically retained in the feed conveyor where it can more easily be removed manually. Since the grinding drum is typically rotating such that cutters mounted to the outer perimeter of the drum are traveling at a high rate of speed, any ungrindable material is subjected to highly dynamic impact loading. The dynamic impact loading is then transferred to this single anvil, or the feed table adjacent the anvil. In certain instances, the loading can be sufficient enough to damage the anvil and supporting structure. A robust, replaceable anvil and supporting structure is thus advantageous. In other cases, highly abrasive material is processed, which wears away the anvil. It is desirable to easily maintain the anvil if wear is excessive; a removable anvil facilitates such maintenance. In general, improvement has been sought with respect to such arrangements, generally to better accommodate: ease of use, assembly, and maintenance; and improved component and equipment life. SUMMARY One aspect of the present disclosure relates to a grinding machine having a mill box, a grinding drum positioned within the mill box, and a feed table for transporting material to the mill box. The grinding machine includes an anvil oriented generally parallel to grinding drum. The anvil includes a first surface and a second surface that define a wedge-shaped portion. The anvil is oriented such that the first surface of the wedge shaped portion is generally aligned with the transport plane of the feed table. In another aspect, the present disclosure relates to a grinding machine having a mill box with opposite sides and a grinding drum. The opposite sides of the mill box define a grinding width of the machine. A wedge-shaped anvil is located adjacent to the grinding drum and positioned within apertures defined in the sides of the mill box. The anvil has a length greater than the grinding width of the mill box such that the ends of the anvil extend beyond the sides of the mill box. In yet another aspect, the present disclosure relates to mounting arrangement for a grinding machine. The mounting arrangement includes an adapter having a first support surface configured to support an end of a feed table of the grinding machine, and a second support surface configured to support an anvil of the grinding machine. A variety of examples of desirable product features or methods are set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practicing various aspects of the disclosure. The aspects of the disclosure may relate to individual features as well as combinations of features. It is to be understood that both the foregoing general description and the following detailed description are explanatory only, and are not restrictive of the claimed invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the left side of a materials grinder embodying various features of the present invention; FIG. 2 is a partial left-side elevation view of the materials grinder shown in FIG. 1; FIG. 3 is a partial cross-section of the materials grinder of FIG. 1, taken along line 3-3; FIG. 4 is a partial right-side elevation view of the materials grinder shown in FIG. 1; FIG. 5 is a cross-section of the materials grinder of FIG. 4, taken along line 5-5; FIG. 6 is a cross-section of the materials grinder of FIG. 4, taken along line 6-6; FIG. 7 is a partially exploded perspective view of the right side of the materials grinder of FIG. 1, showing an anvil, a mount, and a clamp arm of the present invention; FIG. 8 is a partial perspective view of the right side of the materials grinder of FIG. 1, showing the anvil, the mount, and the clamp arm in installed positions; and FIG. 9 is a cross-sectional view of the anvil shown in FIG. 7. DETAILED DESCRIPTION Reference will now be made in detail to various features of the present disclosure that are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Referring to the drawings, and in particular to FIG. 1, a materials grinder 100 is illustrated. This materials grinder 100 is a horizontal grinder and includes a mill box 150 and a feed hopper 110 to transport material to the mill box 150. The materials grinder 100 can be used in a wide variety of grinding application. For, example, the material grinder 100 may be used to grind material such as leaves, shingles, small branches and is also capable of grinding larger objects such as large branches, boards, planks. Still referring to FIG. 1, the feed hopper 110 includes a feed table 112 and sides 114. The feed table 112 defines a transport plane or bottom 111 of the feed hopper 110 onto which material is loaded for transport to the mill box 150. That is, in use, material is loaded onto the feed table 112 of the feed hopper 110, which propels the material towards a mill box 150. The feed table 112 includes a first conveyor roller 118, a second conveyor roller 202, and a conveyor arrangement 130. The conveyor arrangement 130 includes conveyor bars 116 that are attached to a conveyor chain 117. The conveyor chain 117 is routed around the first conveyor roller 118. The second conveyor roller 202 is powered, typically by a hydraulic motor, in a manner that allows the conveyor chain 117 and the conveyor bars 116 to be propelled in either direction. The first conveyor roller 118 is supported by the sides 114 of the feed hopper 100. The second conveyor roller 202 (FIG. 2) is mounted to sides 300 of the mill box 150. Cross-members 308, 318 extend between the sides 300 of the mill box 150. In the illustrated embodiment, the cross-members 308, 318 are constructed of square tubing material. The cross-members 308, 318 provide the structure necessary to support the basic elements of the materials grinder 110, including a grinding drum 160, the second conveyor roller 202, an anvil 500, screens 180, and a feed roller 120. The first cross-member 308 is attached to each of the mill box sides 300 by a gusset 309. Referring now to FIGS. 1 and 2, the feed roller 120 is mounted on a feed roller shaft 122. The feed roller shaft 122 is supported on mount arms 124. During operation, material is propelled or conveyed towards the grinding drum 160 by the conveyor arrangement 130. As the material is conveyed, the feed roller 120 (driven by a hydraulic motor) engages the material to provide additional feed pressure to urge the material towards the grinding drum 160. Referring now to FIG. 3, the grinding drum 160, the conveyor roller 202, and an anvil 500 are illustrated. The grinding drum 160 is similar to that disclosed in U.S. Pat. No. 6,422,495, herein incorporated by reference. The grinding drum 160 includes cutters 164 mounted on hammers 166. As the material approaches the grinding drum 160, the material is contacted by cutters 164 and forced into contact with the anvil 500. Referring now to FIG. 9, the anvil 500 is preferably a wedge-shaped anvil having first and second surfaces 502, 504. The first and second surfaces 502, 504 define a wedge portion 524 of the anvil 500. The material is fractured or broken upon impact with the cutters 164, or by a crushing or shearing force acting generally perpendicular to the first surface 502 of the anvil 500 (the shearing force being directionally represented by force vector 510 of FIG. 3). Some material may be sized such that it wedges between the anvil 500 and the cutters 164 and hammers 166, thereby generating a reaction force acting generally perpendicular to a third surface 503 of the anvil 500 (the reaction force being directionally represented by force vector 512 of FIG. 3). The material that passes by the anvil 500 will be further ground to a size necessary to pass through the screens 180. Once through the screens 180, the material will exit the mill box 150 and fall onto a discharge conveyor 126 (FIG. 2) for transport to a secondary conveyor 200 (FIG. 1) where it may be further transferred to any desired position (such as to a pile beside the materials grinder 100). Referring to FIG. 3, the primary grinding action of the present materials grinder involves the interaction of the cutters 164, which are traveling at a high rate of speed, with the stationary anvil 500. In particular, typical material, as represented by material 204, will be impacted by cutters 164 and driven down towards the anvil 500 and conveyor roller 202. The anvil 500 is placed in close proximity to the grinding drum 160 so that any ungrindable material, not able to pass by the anvil 500, will be retained at the infeed area 142, in order to prevent damage to other components including the screen 180. Upon contact with the grinding drum 160, the ungrindable materials will be forced backward, away from grinding drum 160, or will become trapped between cutters 164 and anvil 500. If the ungrindable material becomes trapped and stops the grinding drum 160, the resulting rapid deceleration will generate significant and unusual overload forces acting against either the anvil 500, the roller 202, or a combination of both. The anvil 500, the roller 202, and the supporting framework may thus be subjected to severe loads. The present disclosure relates to an anvil 500 having a robust configuration, and a mounting arrangement 330 for the anvil 500 and the roller 202 that permits easy maintenance of the anvil 500 and the feed table 112. Preferably, the anvil 500 is replaceable and the mounting arrangement 330 configured such that the anvil 500 is easily accessible for replacement and maintenance purposes. Referring now to FIG. 4, the anvil 500 and the mounting arrangement 330 are illustrated (the conveyor roller 202 is not shown for purposes of clarity). The mounting arrangement 330 includes adapters 210 positioned on opposite sides of the material grinder 100 (FIG. 5) such that the anvil 500 is generally parallel to an axis A-A of rotation of the grinding drum 160. Each of the adaptors 210 is mounted to an outside surface 324 (FIG. 5) of the corresponding mill box side 300 with fasteners 230. The adapter 210 is restrained in a stationary rotational orientation by a stop structure 219 that reacts against the gusset 309. In particular, the gusset 309 includes a reaction surface 310 (FIG. 7). The stop structure 219 of the adaptor 210 is configured to react with the reaction surface 310 of the gusset 309 to transfer a portion of any load applied to the anvil 500 directly to the cross-member 308. Accordingly, the cross-member 308 structurally supports the gusset 309 to maintain the adapter 201 in the stationary rotational orientation. Referring now to FIG. 7, the adaptor 210 also includes a bearing mount surface 214 and first and second anvil mounting surfaces 216, 218. The adaptors 210 are configured to fit into apertures 302 formed in the sides 300 of the mill box 150. Each of the adaptors 210 includes a flange 220 having holes 212 to receive the fasteners 230 that secure the adaptor to the corresponding mill box side 300. The anvil 500 is structurally configured to provide sufficient rigidity that can withstand grinding forces generated during operation, and to provide adequate protection for, and to cooperate with, the second conveyor roller 202 and conveyor chain 117. As shown in FIG. 3, the first surface 502 of the anvil 500 is essentially a planar extension of the transport plane 111 of the feed table 112 (FIG. 1). Referring still to FIG. 3, the anvil 500 is also oriented such that the second surface 504 cooperates with the conveyor chain 117. For example, as material progress toward the anvil 500, the material reaches a first nip point 506. The first nip point 506 is where the material transfers from the conveyor chain 117 to the anvil 500. At the first nip point 506, the second surface 504 is closest to the second conveyor roller 202 and the transport plane 111 of the feed table 112 to assist in lifting material off the conveyor chain 117 and reduce the amount of material carried around the second conveyor roller 202. Any material carried around the second conveyor roller 202 will drop out of the feed hopper 110 without being ground. Still referring to FIG. 3, the clearance between the conveyor chain 117 and the second surface 504 of the anvil 500 is minimized at the first nip point 506. Preferably, the second surface 504 is a generally flat surface that lies perpendicular to a radial line R projecting from the center of roller 202 toward the first nip point 506. This orientation reduces the chance of material wedging between the second conveyor roller 202 and the second surface 504 of the anvil 500. Referring again to FIG. 9, the wedge-shaped portion 524 of the anvil 500 is configured to resist deflection when the anvil is subjected to the force vector 510 or 512. In particular, the anvil 500 has a tapering thickness defined by a varying distance (d, for example) between the first surface 502 and the second surface 504. The thickness of the wedge shape anvil 500 increases to a maximum thickness T at a point where the first surface 502 defines a second nip point 508 (FIG. 3). The second nip point 508 is where there is minimum clearance between the anvil 500 and the grinding drum 160. In the illustrated embodiment, the maximum thickness T is between 2 inches and 6 inches, preferably between 4.5 inches to 5 inches. Referring again to FIG. 3, the orientation of the first surface 502 affects the performance of the grinder; for instance if the first surface 502 is arranged higher than the feed table 112, or if the first surface is angled upward such that nip point 508 is higher than nip point 506, as compared to the bottom plane 111 of the feed table, the feeding characteristics will be negatively affected. Thus, preferably, the first surface 502 of the anvil 500 is generally aligned with the bottom plane 111 of the feed table. That is, the first surface 502 of the anvil 550 is oriented generally parallel to the bottom plane 111 of the feed table such that nip point 508 is aligned with nip point 506. In an alternative embodiment, the first surface 502 may be oriented to angle downward such that nip point 508 is lower than nip point 506. The anvil 500 also has a generally rectangular cross-section portion 514 (partially represented by a dashed line) to provide additional rigidity to the overall structure. The rectangular cross-section portion 514 is in part defined by an extension 516 of the second surface 504 and the third surface 503 of the anvil 500. As shown in FIG. 9, the third surface 503 of the anvil 500 extends at an angle from the first surface 502. The third surface 503 is oriented generally parallel to the second surface 504. The geometry and structural orientation of the disclosed anvil 500 in relation to the other components of the materials grinder 100 are important to provide proper function while simultaneously providing adequate structural rigidity. For example, the relative position of the anvil 500 and the conveyor roller 202 at the first nip point 506; the clearance between the anvil 500 and grinding drum 160 at the second nip point 508; the orientation of the first surface 502 of the anvil 500 relative to the feed table 112 and the grinding drum 160; the orientation and increasing clearance of second surface 504 of the anvil 500 relative to the second conveyor roller 202; and the overall thickness of the anvil are all features that contribute to the structural enhancement of the disclosed materials grinder 100. In the preferred embodiment, the wedge-shaped anvil 500 is a solid construction that further enhances structural rigidity. That is, the anvil 500 is made of a construction that has no through holes, for example. The solid construction of the presently disclosed anvil eliminates stress concentrations associated with through holes or other similar structures that may weaken the structural integrity of the anvil. In addition to the shape of the anvil 500, the anvil is preferably constructed of a material that provides mechanical properties suitable to withstand load and wear conditions experienced during operation. In one embodiment, the anvil can be constructed of a high yield strength alloy steel, such as a steel marketed as T-1® by Bethlehem Steel having a minimum yield strength of 100,000 psi. In the illustrated embodiment, the anvil 500 includes beads of hardface weld material 518, illustrated in FIGS. 5 and 7, applied to the first and second surfaces 502, 503. Referring now to FIGS. 5 and 7, the mill box sides 300 are spaced apart by the cross-members 308, 318 (FIG. 3) to define the grinding width W1 of the materials grinder 100. Each of the mill box sides 300 includes an aperture 304 configured to receive the anvil 500. The anvil 500 passes through one mill box side 300 to and through the opposite mill box side 300. In the preferred embodiment, the anvil 500 has a length L (FIG. 5) that is greater than the grinding width W1 defined by the mill box sides 300 of the mill box 150. That is, the anvil 500 is longer than the grinding width W1 such that when properly positioned, ends 520 of the anvil 500 extend beyond an outer surface 324 of the mill box sides 300. The ends 520 of the anvil 500 engage with the first and second anvil mounting surfaces 216 and 218 of each of the adaptors 210. Any forces applied to the anvil 500 are transferred to the adaptors 210. Referring now to FIG. 5, the mounting arrangement 330 of the present disclosure utilizes the adaptors 210 to support and position both the anvil 500 and the second conveyor roller 202. In the illustrated embodiment, the bearing mount surface 214 is an annular bearing mount surface and the first and second anvil mounting surfaces are planar surfaces. The conveyor roller 202 is rotationally supported by bearings 240. The bearings 240 are installed at the annular bearing mount surface 214 (see also FIG. 7) of the adaptors 210. The anvil 500 is supported by the first and second planar anvil mounting surfaces 216 and 218 (FIG. 7), while being positioned and retained in a direction parallel to the grinding drum axis A-A. The anvil 500 is secured in position by bolts 242 and clips 244 as shown in FIGS. 6 and 8. Referring back to FIG. 4, the mounting arrangement 330 also includes clamp arms 400. The anvil 500 is further restrained by the clamp arms 400 having a width W2 (FIG. 5) sized and configured to provide a secure clamping force on the anvil 500. The clamp arm 400 forces the anvil 500 against the first and second anvil mounting surfaces 216 and 218 such that the anvil 500 can be described as a beam with fixed supports. Referring to FIG. 7, in order to achieve this type of mounting, the first and second anvil mounting surfaces 216 and 218 are sized to provide sufficient load carrying areas A1, A2. Preferably, each of the load carrying areas A1, A2 is defined by a width W3 of at least one inch. Referring now to FIGS. 4 and 8, the clamp arm 400, includes a first end 402 and a second end 406. A contact structure 404 is located between the first and second ends 402, 406 of the clamp arm 400. The first end 402 of the clamp arm 400 is interconnected to an actuator 410. The actuator 410 includes a bolt 411 and a slug 412. The bolt 411 mounts the first end 402 of the actuator 410 to the first cross-member 308. The second ends 406 of each of the clamp arms 400 are configured to react against frame members 306. Each of the frame members 306 is attached to the sides 300 of the mill box 150. In use, the clamp arm 400, bolt 411, and slug 412 are positioned generally as shown in FIG. 4 relative to the adaptor 210. The bolt 411 is then secured to the first cross-member 308. As the bolt 411 is tightened, the contact structure 404 of the clamp arm 400 contacts the anvil 500 and pivots the second end 406 of the clamp arm 400 upward. The second end 406 of the clamp arm anchors or reacts against the frame member 306 (see also FIGS. 7 and 8). This creates a clamp force against the anvil 500 at the anvil contact structure 404. The clamp force applied to the anvil 500 by the anvil contact structure 404 is transferred through the adaptor 210 creating a reaction force at the stop structure 219. The reaction force at the stop structure 219 acts against the reaction surface 310 (FIG. 8) of the gusset 309. The gusset 309 thereby transfers some of the clamp force to the cross-member 308 to which the gusset 309 is attached. In addition, some of the clamp force is transferred from the adaptor 210 to the mill box sides 300 through the frame member 306 and the bore 302. Preferably, the mounting arrangement 330 of the present disclosure accommodates a removable and replaceable anvil 200 via the cooperative interaction of the adapter 210. Preferably, the first and second anvil mounting surfaces 214, 216, and the clamp arms 400 of the adapter 210 are located outside of the mill box sides 300 for accessibility. In accord with this feature, the clamp arm 400 secures the anvil 500 by clamping the ends 520 of the anvil 500 that extend beyond the outer surface 324 of the mill box sides 300. This provides easy access to all the securing components of the mounting arrangement 330 for easy maintenance of the anvil 500. In addition, the mounting arrangement 330 eliminates the need for welding the anvil for securing purposes. Thereby, the anvil 500 can be constructed from a wide range of materials without concern for welding compatibility. The geometry and structural orientation of the disclosed anvil 500 interacts with the feed table 112 and with the grinding drum 160 to optimize performance of the materials grinder 100. The preferred mounting arrangement 330 allows the anvil 500 to be predictably positioned relative to the feed table 112 by incorporating into the adaptor 210 both the mount for the anvil 500 and the mount for the conveyor roller 202. What is meant by predictably positioned is that the relative positions of the feed table and anvil are dependent upon one another because each of the feed table 112 and the anvil 500 mount to a single component, i.e. the adaptor 210. The adaptor 210 is constructed and arranged such that loads applied to the anvil 500 are transferred from the anvil to the structural cross-members 308, 318 and to the mill box sides 300. This enhances the fatigue life of the anvil 500. Various principles of the embodiments of the present disclosure may be used in applications other than the illustrated down-cut horizontal grinders. For example, the principals of the present disclosure may likewise be adapted to a tub grinder or to an up-cut horizontal grinder. The above specification provides a complete description of the present invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, certain aspects of the invention reside in the claims hereinafter appended. | <SOH> BACKGROUND <EOH>The grinding of a variety of materials can have a desirable effect. For instance, grinding of some types of waste results in increased rate of decomposition, which is useful in landfill operations; grinding wood waste produces mulch that is useful in landscaping applications; and grinding asphalt is useful in recycling efforts. Some types of shingles can also be ground for use in asphalt production. The benefits of and need for such recycling processes continue to grow. Several types of machines are used in grinding applications. One type is known as a horizontal grinder. An example of a horizontal grinder is disclosed in U.S. Pat. No. 5,881,959. Horizontal grinders typically include a horizontal feed table onto which material to be ground is placed. The feed table is capable of moving the material to a point where a feed roller begins to cooperate with the feed table. The feed roller generally presses down on top of the material, while being rotationally powered, to assist in forcing the material into contact with the side of a grinding drum. The grinding drum is as wide as the feed table and rotationally powered on a generally horizontal axis perpendicular to the direction of travel of the feed table. The grinding drum typically includes hammers or cutters mounted to the outer perimeter of the drum to impact the material as it is fed from the feed roller/feed table. These hammers or cutters tend to propel the material either up, for grinders known as up-cut grinders, or down, for grinders known as down-cut grinders. Down-cut grinders force the material past a stationary bar, typically known as an anvil, which is in relatively close proximity to the outer swing diameter of the hammers or cutters. Because of the anvil's relative close proximity, the size of the outer swing diameter is reduced, as necessary, to travel past the anvil. Once the material passes the anvil, the material is further reduced, as necessary, to pass through a screen. In the '959 patent, a primary anvil is positioned a slight distance from the grinding drum such that a primary grind will occur as the material is forced past the primary anvil. The material is further reduced at a secondary anvil. If the material is ungrindable, the material passes through a trap door positioned between the primary and secondary anvils. This arrangement involves several components and moving parts that add complexity to the overall design of the grinder. An alternative design, marketed by Vermeer Mfg (Model HG525) includes a single anvil that is located in close proximity to the grinding drum such that any material that passes by this single anvil, is capable of passing through the screens. Ungrindable material is typically retained in the feed conveyor where it can more easily be removed manually. Since the grinding drum is typically rotating such that cutters mounted to the outer perimeter of the drum are traveling at a high rate of speed, any ungrindable material is subjected to highly dynamic impact loading. The dynamic impact loading is then transferred to this single anvil, or the feed table adjacent the anvil. In certain instances, the loading can be sufficient enough to damage the anvil and supporting structure. A robust, replaceable anvil and supporting structure is thus advantageous. In other cases, highly abrasive material is processed, which wears away the anvil. It is desirable to easily maintain the anvil if wear is excessive; a removable anvil facilitates such maintenance. In general, improvement has been sought with respect to such arrangements, generally to better accommodate: ease of use, assembly, and maintenance; and improved component and equipment life. | <SOH> SUMMARY <EOH>One aspect of the present disclosure relates to a grinding machine having a mill box, a grinding drum positioned within the mill box, and a feed table for transporting material to the mill box. The grinding machine includes an anvil oriented generally parallel to grinding drum. The anvil includes a first surface and a second surface that define a wedge-shaped portion. The anvil is oriented such that the first surface of the wedge shaped portion is generally aligned with the transport plane of the feed table. In another aspect, the present disclosure relates to a grinding machine having a mill box with opposite sides and a grinding drum. The opposite sides of the mill box define a grinding width of the machine. A wedge-shaped anvil is located adjacent to the grinding drum and positioned within apertures defined in the sides of the mill box. The anvil has a length greater than the grinding width of the mill box such that the ends of the anvil extend beyond the sides of the mill box. In yet another aspect, the present disclosure relates to mounting arrangement for a grinding machine. The mounting arrangement includes an adapter having a first support surface configured to support an end of a feed table of the grinding machine, and a second support surface configured to support an anvil of the grinding machine. A variety of examples of desirable product features or methods are set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practicing various aspects of the disclosure. The aspects of the disclosure may relate to individual features as well as combinations of features. It is to be understood that both the foregoing general description and the following detailed description are explanatory only, and are not restrictive of the claimed invention. | 20040220 | 20081209 | 20050825 | 94120.0 | 0 | MILLER, BENA B | APPARATUS AND METHOD FOR SUPPORTING A REMOVABLE ANVIL | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,783,597 | ACCEPTED | Universal tray design having anatomical features to enhance fit | A tray-shaped dental treatment device includes a moisture-resistant barrier layer having a front side wall and a bottom wall, and a dental treatment composition. In addition, the tray-shaped dental treatment device includes at least one of the following anatomical features to enhance the fit of the device: (1) the bottom wall includes a plurality of cuts positioned to help the bottom wall better conform to abrupt changes in the diameters of a person's teeth where the bicuspids and canines meet, or (2) the bottom wall includes at least one V-shaped or U-shaped indentation configured to be inserted into the depression typically found along the top surfaces of a person's molars, or (3) the front side wall and bottom wall include radii of curvature that account for typical flaring of a patient's incisors. | 1. A tray-shaped dental treatment device comprising: a moisture-resistant barrier layer having a front side wall and a bottom wall; said bottom wall including a plurality of cuts positioned so as to help said bottom wall better conform to abrupt changes in the diameter of a person's teeth where the bicuspids and canines meet; and a dental treatment composition. 2. A tray-shaped dental treatment device as recited in claim 1, further comprising an exoskeleton having a tray-like configuration configured to receive said moisture-resistant barrier layer. 3. A tray-shaped dental treatment device as recited in claim 2, wherein said exoskeleton includes a handle. 4. A tray-shaped dental treatment device as recited in claim 1, wherein each of said cuts comprises a notch. 5. A tray-shaped dental treatment device as recited in claim 1, wherein said tray-shaped dental treatment device is sized and configured so as to fit over at least a portion of a person's upper dental arch. 6. A tray-shaped dental treatment device as recited in claim 1, wherein said tray-shaped dental treatment device is sized and configured so as to fit over at least a portion of a person's lower dental arch. 7. A tray-shaped dental treatment device as recited in claim 1, wherein said dental treatment composition comprises at least one of a sticky viscous gel, a less viscous gel, a highly viscous putty, or a substantially solid composition. 8. A tray-shaped dental treatment device as recited in claim 7, wherein the dental treatment composition includes at least one tissue adhesion agent. 9. A tray-shaped dental treatment device as recited in claim 8, wherein said dental treatment composition further includes at least one active agent. 10. A tray-shaped dental treatment device as recited in claim 9, said active agent comprising at least one of a dental bleaching agent, a desensitizing agent, a remineralizing agent, an antimicrobial agent, an antiplaque agent, an anti-tartar agent, or another medicament. 11. A tray-shaped dental treatment device as recited in claim 8, said tissue adhesion agent comprising polyvinyl pyrrolidone. 12. A tray-shaped dental treatment device as recited in claim 8, said tissue adhesion agent comprising at least one of carboxypolymethylene, polyethylene oxide, polyacrylic acid, copolymer of polyacrylic acid, polyacrylate, polyacrylamide, copolymer of polyacrylic acid and polyacrylamide, PVP-vinyl acetate copolymer, carboxymethylcellulose, carboxypropylcellulose, polysaccharide gum, and protein. 13. A tray-shaped dental treatment device as recited in claim 8, said tissue adhesion agent having a concentration in a range of about 10% to about 90% by weight of said treatment composition. 14. A tray-shaped dental treatment device as recited in claim 8, said tissue adhesion agent having a concentration in a range of about 20% to about 80% by weight of said treatment composition. 15. A tray-shaped dental treatment device as recited in claim 8, said tissue adhesion agent having a concentration in a range of about 40% to about 75% by weight of said treatment composition. 16. A tray-shaped dental treatment device as recited in claim 8, wherein the treatment composition comprises a substantially solid adhesive composition and at least one of a sticky viscous gel, a less viscous gel, or a highly viscous putty adjacent to at least one of said adhesive composition or said barrier layer. 17. A tray-shaped dental treatment device as recited in claim 1, wherein said device is contained within a sealed package prior to use. 18. A tray-shaped dental treatment device as recited in claim 1, further comprising a notch in said bottom wall so as to help said tray-shaped dental treatment device to more easily spread open or compress in the area of a person's incisors. 19. A tray-shaped dental treatment device as recited in claim 1, further comprising at least one V-shaped or U-shaped indentation in said bottom wall configured to be inserted into the depression typically found along the top surfaces of a person's molars. 20. A tray-shaped dental treatment device as recited in claim 1, wherein said front side wall and bottom wall include radii of curvature that account for typical flaring of a patient's incisors. 21. A tray-shaped dental treatment device comprising: a moisture-resistant barrier layer having a front side wall and a bottom wall, said bottom wall including a plurality of cuts positioned so as to help said bottom wall better conform to abrupt changes in the diameter of a person's teeth where the bicuspids and canines meet; a substantially solid adhesive composition that has increased adhesiveness to teeth when moistened with saliva or water, said adhesive composition including; at least one active agent; and at least one tissue adhesion agent that contributes or provides increased adhesiveness to oral tissue when moistened with saliva; and at least one of a sticky viscous gel, a less viscous gel, or a highly viscous putty adjacent to at least one of said barrier layer or said adhesive composition. 22. A tray-shaped dental treatment device as recited in claim 21, further comprising an exoskeleton having a tray-like configuration configured to receive said moisture-resistant barrier layer. 23. A tray-shaped dental treatment device as recited in claim 21, said barrier layer comprising a mixture of ethyl vinyl acetate and polypropylene. 24. A tray-shaped dental treatment device as recited in claim 23, said barrier layer comprising up to 50% polypropylene by weight. 25. A tray-shaped dental treatment device as recited in claim 23, said barrier layer comprising about 5% to about 40% polypropylene by weight. 26. A tray-shaped dental treatment device as recited in claim 23, said barrier layer comprising about 10% to about 30% polypropylene by weight. 27. A tray-shaped dental treatment device as recited in claim 21, said barrier layer comprising at least one polyolefin. 28. A tray-shaped dental treatment device as recited in claim 27, said polyolefin comprising at least one of polyethylene, high density polyethylene, low density polyethylene, ultra-low density polyethylene, polypropylene, or polytetrafluoroethylene. 29. A tray-shaped dental treatment device as recited in claim 21, said barrier layer comprising at least one of wax, metal foil, paraffin, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, polycaprolactone, polyester, polycarbonate, polyurethane, polyamide, or polyesteramide. 30. A tray-shaped dental treatment device as recited in claim 21, wherein said barrier layer has a cross-sectional thickness in a range of about 0.025 mm to about 1.5 mm. 31. A tray-shaped dental treatment device as recited in claim 21, wherein said barrier layer is sized and configured so as to approximately terminate at or near a person's gingival margin when said tray-shaped dental treatment device is in use. 32. A tray-shaped dental treatment device as recited in claim 21, said at least one sticky viscous gel, less viscous gel, or highly viscous putty includes a dental bleaching agent. 33. A tray-shaped dental treatment device as recited in claim 32, said dental bleaching agent comprising at least one of carbamide peroxide, metal peroxide, percarbonate, perborate, peroxy acid, peroxy acid salt, chlorite, or hypochlorite. 34. A tray-shaped dental treatment device as recited in claim 32, said dental bleaching agent having a concentration in a range of about 5% to about 80% by weight of said at least one sticky viscous gel, less viscous gel, or highly viscous putty. 35. A tray-shaped dental treatment device as recited in claim 32, said dental bleaching agent having a concentration in a range of about 10% to about 60% by weight of said at least one sticky viscous gel, less viscous gel, or highly viscous putty. 36. A tray-shaped dental treatment device as recited in claim 32, said dental bleaching agent having a concentration in a range of about 20% to about 50% by weight of said at least one sticky viscous gel, less viscous gel, or highly viscous putty. 37. A tray-shaped dental treatment device comprising: a moisture-resistant barrier layer having a front side wall and a bottom wall; said bottom wall including at least one V-shaped or U-shaped indentation configured to be inserted into the depression typically found along the top surfaces of a person's molars; and dental treatment composition. 38. A tray-shaped dental treatment device comprising: a moisture-resistant barrier layer having a front side wall and a bottom wall; said front side wall and bottom wall including radii of curvature that account for typical flaring of a patient's incisors; and a dental treatment composition. 39. A kit for use in bleaching a person's teeth comprising a plurality of tray-shaped dental treatment devices according to claim 1. 40. A kit as recited in claim 39, wherein at least some of said devices are stacked and interested together. 41. A kit as recited in claim 39, wherein said kit includes from 3 to 10 tray-shaped dental treatment devices. 42. A method for bleaching a person's teeth, comprising: (a) obtaining a tray-shaped dental treatment device as recited in claim 1; (b) placing said tray-shaped dental treatment device over at least a portion of the person's teeth for a desired time period, a moistened adhesive composition or other dental treatment composition adhering and retaining said tray-shaped dental treatment device against the person's teeth during the desired time period. 43. A method for bleaching a person's teeth as recited in claim 42, wherein said tray-shaped dental device includes a substantially solid adhesive composition that has increased adhesiveness to teeth when moistened with saliva or water, said substantially solid adhesive composition including at least one tissue adhesion agent that contributes or provides increased adhesiveness to oral tissue when moistened; and wherein said method further comprises moistening an exposed surface of said substantially solid adhesive composition so as to increase adhesiveness of said adhesive composition to teeth prior to placing said device over at least a portion of the person's teeth. 44. A method for bleaching a person's teeth as recited in claim 43, wherein moistening an exposed surface of said substantially solid adhesive composition is performed by applying water or an aqueous solution to the exposed surface. 45. A method for bleaching a person's teeth as recited in claim 43, wherein moistening an exposed surface of the substantially solid adhesive composition is performed by allowing residual saliva on the person's teeth to moisten the exposed surface as said tray-shaped dental treatment device is placed over the person's teeth. 46. A method for bleaching a person's teeth as recited in claim 42, further comprising removing said tray-shaped dental treatment device. 47. A method for bleaching a person's teeth as recited in claim 46, said tray-shaped dental treatment device being removed about 10 to about 30 minutes after being placed over the person's teeth. 48. A method for bleaching a person's teeth as recited in claim 46, said tray-shaped dental treatment device being removed about 30 minutes to about 2 hours after being placed over the person's teeth. 49. A method for bleaching a person's teeth as recited in claim 46, said tray-shaped dental treatment device being removed about 2 hours to about 12 hours after being placed over the person's teeth. | BACKGROUND OF THE INVENTION 1. The Field of the Invention The present invention is in the field of dental tray shaped devices used to provide a desired dental treatment to a person's teeth. The device can be used for dental treatments such as bleaching, administration of fluoride, or application of other medicines. 2. The Relevant Technology Virtually all people desire white or whiter teeth. To achieve this goal, people have veneers placed over their teeth or have their teeth chemically bleached. A common bleaching method involves the use of a dental tray that is custom-fitted to a person's teeth and that is therefore comfortable to wear. One type of customized tray is made from a stone cast of a person's teeth. Another is customized directly using a person's teeth as a template (e.g., “boil-and-bite” trays). Non-customized trays that approximate the shapes and sizes of a variety of users' dental arches have also been used. A dental bleaching composition is placed into the tray and the tray placed over the person's teeth for a desired period of time. Another bleaching method involves painting a bleaching composition directly onto a person's teeth. A perceived advantage of paint-on bleaching is that it eliminates the need for a dental tray. The main disadvantage of a paint-on bleaching composition is that it remains directly exposed to the person's saliva and disruptive forces found in a person's mouth. As a result, a significant portion of the bleaching composition does not remain on the teeth where bleaching is desired. Some or all of the composition can dissolve away into the person's saliva and/or be transferred to adjacent oral tissues, potentially irritating soft oral tissues. Another tooth bleaching method involves placing a flexible bleaching strip over a user's tooth surfaces. Conventional bleaching strips comprise a flexible plastic strip coated with a dental bleaching gel of moderate viscosity and relatively low stickiness on the side of the strip facing the user's teeth. To install the bleaching strip, a portion of the bleaching strip is placed over the front surfaces of the user's teeth, and the remainder is folded around the occlusal edges of the teeth and against a portion of the lingual surfaces. Like paint-on bleaching compositions, this procedure does not require the use of dental trays. Unlike paint-on bleaching compositions, bleaching strips include a plastic barrier that, at least in theory, keeps the dental bleaching gel from diffusing into the user's mouth. In reality, because of the generally poor adhesion of bleaching strips to the user's teeth, coupled with their generally flimsy nature, it is often difficult for the user to maintain the bleaching strip in its proper position for the recommended time. Conventional bleaching strips are prone to slip off the teeth as a result of even minimal movement of the user's mouth, jaw or tongue. Indeed, it is recommended that the user not eat, drink, smoke or sleep while wearing the bleaching strip. In practice, it is difficult to talk or smile while properly maintaining the bleaching strip in the correct position. Even if a user successfully maintains a conventional bleaching strip in its proper position during the recommended bleaching period, the bleaching gel often diffuses into the person's saliva, potentially causing a poor taste in the user's mouth and possibly discomfort to soft oral and throat tissues. The tendency of the bleaching gel to diffuse into the user's mouth can be accelerated through even minimal shifts of the bleaching strip over the user's teeth, with each shift potentially causing bleaching gel that remains adhered to the user's teeth, but not covered by the plastic strip, to be exposed to saliva in the user's mouth. In some cases, the bleaching strip can become so dislodged or mangled that it must be removed by the user and replaced with a fresh bleaching strip to complete the recommended bleaching time. This multiplies the cost and hassle of using conventional bleaching strips. In practical terms, the use of conventional bleaching strips can greatly inhibit even the simplest of activities that involve movement of the user's mouth or tongue, such as talking, smiling, making other facial expressions, or even swallowing (which normally occurs subconsciously throughout the day). Indeed, the time when a person's mouth and tongue are the least prone to move is at night while the person is sleeping. Unfortunately, it is recommended that conventional bleaching strips not be used while sleeping, presumably to prevent accidental choking on an inadvertently dislodged bleaching strip. This confirms the tendency of conventional bleaching strips to easily dislodge from a user's teeth. Ultimately, the main impediment to successful bleaching is the failure of users to complete the prescribed bleaching regimen. If the bleaching apparatus is difficult to install over a person's teeth, requires numerous repetitions to achieve observable results, or is uncomfortable to wear, the user may simply give up and prematurely abort the prescribed bleaching regimen. Thus, even if dental bleaching is possible using a particular bleaching apparatus or method, it is less likely to occur if the inadequacies of the bleaching apparatus or method cause a user to become discouraged before desired results are attained. In view of the foregoing, there is an ongoing need for improved bleaching apparatus and methods that are simple and easy to use and that reliably remain in position over the user's teeth so as to reduce diffusion of bleaching composition into a user's oral cavity. Such improvements would be expected to improve or encourage compliance by the user. BRIEF SUMMARY OF THE PREFFERED EMBODIMENTS The present invention generally relates to improved dental treatment devices used to treat (e.g., bleach) a person's teeth. The inventive tray-shaped device includes a front side wall and a bottom wall. In addition, the tray-shaped device includes at least one of the following features to enhance anatomical fit: (1) the bottom wall includes a plurality of cuts positioned to help the bottom wall better conform to abrupt changes in the diameters of a person's teeth, particularly where the bicuspids and canines meet, (2) the bottom wall includes at least one V-shaped or U-shaped indentation configured to be inserted into the depression typically found along the top surfaces of a person's molars, and (3) the front and bottom wall include radii of curvature that account for typical flaring of a patient's incisors. In one embodiment of a treatment device according to the invention, the bottom wall includes a cut on either side of the device approximately corresponding to the intersection of a person's canines and bicuspids. The cuts help to compensate for the fact that bicuspids are significantly thicker than canines by allowing for an abrupt discontinuity in the bottom wall of the treatment device. Without these cuts the bottom wall would be harder to conform to the canines since the adjacent bicuspids would tend to push the bottom wall away from the canines, thus potentially dislodging the bottom wall in this region. These and any other cuts within the bottom wall may also help compensate for differences between the inner and outer radii of the dental arch generally defined by the inner and outer tooth surfaces. In another embodiment of a treatment device according to the invention, the bottom wall may include V-shaped or U-shaped indentations in the region of a person's molars that cause the bottom wall to better conform to the depression normally found in molars. In the absence of such V-shaped or U-shaped indentations, the bottom wall of the treatment device may have a tendency to span the molars like a bridge between the generally higher outer edges, thereby leaving a gap between the bottom wall and the surface of the molars between the outer edges. Permitting such a gap may inhibit or prevent bleaching the depressed molar surfaces. Moreover, a bottom wall that is stretched between the outer surfaces so as to leave a gap over the molar depressions may result in inadvertent dislodgment of the treatment device when the upper and lower molars are brought together. For example, if the bottom wall of a treatment device is pushed into the molar depression by the opposing molars, the front and/or bottom side walls may be pulled down across the tooth surfaces to compensate for this effective lengthening of the bottom wall in the vicinity of the molars. In another embodiment of a treatment device according to the invention, the front and bottom walls may have different radii in order to compensate for the general flaring out of a person's incisors toward the incisal edges. Due to such flaring the diameter of a person's dental arch at the incisal edges is generally greater than the diameter at the gingival margin. Thus the part of the treatment device corresponding to the incisal edges near a person's incisors may advantageously have a larger radius than the part of the treatment device corresponding to the gingival margin. This helps provide better fit of the treatment device over a person's tooth surfaces. The treatment composition may comprise various forms. According to one embodiment, the treatment composition comprises a single continuous bead or layer adjacent to at least a portion of an inner surface of a barrier layer. The treatment composition may comprise a sticky viscous gel, a less viscous gel, a highly viscous putty, or a substantially solid composition that is less adhesive prior to being moistened with saliva or water but that becomes more sticky and adhesive when moistened. In another embodiment, the treatment device includes a layer or region of a substantially solid adhesive composition and a treatment gel or composition adjacent to at least one of the barrier layer or adhesive composition. The adhesive composition may, in some cases, be formulated so as to provide the same treatment as the separate treatment composition, a different treatment, or no treatment. It may provide a protective barrier between the active agent in the treatment composition or gel and the person's gums. It may include a bleaching agent activator in the case where the treatment composition includes a bleaching agent. According to one embodiment, the tray-shaped device includes a barrier layer made of a moisture resistant material. According to one embodiment, the barrier layer comprises a thin, flexible membrane formed from a moisture-resistant polymer material. It is within the scope of the invention to provide barrier layers having any desired thickness or rigidity. In one embodiment, the barrier layer comprises a mixture of ethyl vinyl acetate and polypropylene. The treatment and/or adhesive compositions may include any desired active agent, including, but not limited to, dental bleaching agents, desensitizing agents, remineralizing agents, antimicrobial agents, antiplaque agents, anti-tartar agents, or other medicaments. They also include at least one tissue adhesion agent. A non-limiting example of a suitable tissue adhesion agent is polyvinyl pyrrolidone (PVP). The treatment and/or adhesive: compositions may include other components as desired to yield a final composition having desired properties. Examples of other components include, but are not limited to, plasticizers and humectants (e.g., glycerin, sorbitol, and polyethylene glycol), volatile solvents (e.g., water and alcohols), bleaching agent stabilizers (e.g., EDTA and alkyl sulfates), bleaching agent activators (e.g., metals and metal compounds), neutralizing agents, thickening agents (e.g., fumed silica), flavorants, sweeteners, and the like. The size and shape of the treatment devices according to the invention can be tailored to readily fit a person's upper or lower dental arch. They may also be tailored to fit person's having differently sized or shaped dental arches. The treatment devices are advantageously designed so as to substantially cover the front and lingual surfaces of the teeth and/or gums to be treated. The treatment devices are advantageously flexible and adhesive so as to readily conform to a wide variety of differently-sized teeth and dental arches. The treatment devices according to the invention can be designed to be worn for any desired time period. Increasing the concentration of active agent used generally reduces the required treatment time. Nevertheless, due to the extremely comfortable fit between the inventive treatment devices and the person's teeth, it is possible to wear such devices for extended periods of time. Treatment devices according to the invention can be designed to be worn while, e.g., talking, sleeping, eating, drinking, smiling, frowning, grimacing, yawning, coughing, smoking, or making virtually any facial expression or mouth contortion. This greatly decreases their intrusiveness into everyday activities compared to conventional bleaching strips, which do not reliably adhere to teeth, or intrusive bleaching devices such as large, bulky bleaching dental appliances. The treatment devices can be designed to be worn for as little as a few minutes or as long as several hours. By way of example, not limitation, a typical treatment session of fast duration may last from about 10 to about 30 minutes. A treatment session of intermediate duration may last from about 30 minutes to about 2 hours. A treatment session of long duration, including professional or overnight treatment while a person is sleeping, may last from about 2 hours to about 12 hours. Treatment sessions may be repeated as many times as are needed to obtain a desired result. In the case of tooth bleaching, a clinical whitening effect has been observed after only 1-3 whitening sessions. A typical bleaching regimen will preferably include 1-20 bleaching sessions, more preferably 2-15 bleaching sessions, and most preferably 3-10 bleaching sessions. According to one embodiment, the treatment device may include an associated supporting structure, such as an exoskeleton, prior to use. An exoskeleton may be particularly useful where the barrier layer is very thin and flexible. The exoskeleton may have the same configuration as the treatment device so as to receive and support the front and bottom walls of the treatment device. The exoskeleton can provide additional support and ease of placement to the treatment device while positioning the device over a person's teeth. In one embodiment, the exoskeleton includes a handle to facilitate gripping and maneuverability of the exoskeleton while placing the treatment device over the teeth. Once positioned, the exoskeleton can be removed so as to leave the treatment device in place over the teeth. For convenience of use, multiple treatment devices may be packaged together and sold as a kit. In one embodiment, the number of treatment devices provided with each kit can equal the number of sessions that represent a prescribed treatment regimen. The treatment devices can be sealed collectively or individually as desired. They may contain a removable protective layer on their interior surfaces to protect the treatment and/or adhesive composition from contamination or moisture. It is within the scope of the invention to provide a treatment composition that is initially separate from a barrier layer in the shape of a treatment device and that is applied onto the barrier layer by the end user. These and other advantages and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS To further clarify the above and other advantages and features of the present invention, a more particular description of the invention will be rendered by references to specific embodiments thereof, which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: FIG. 1A is a perspective view of an exemplary tray-shaped dental treatment device configured to fit over at least a portion of a person's upper dental arch, next to an associated exoskeleton; FIG. 1B is a perspective view of an exemplary tray-shaped dental treatment device configured to fit over at least a portion of a person's lower dental arch, next to an associated exoskeleton; FIG. 2 is a perspective view of an exemplary tray-shaped dental treatment device comprising a barrier layer and a substantially solid adhesive composition placed within an exo-skeleton; FIG. 3 is a perspective view of the device of FIG. 2 with a gel treatment composition placed within the tray shaped device; FIG. 4A is a cross sectional view of an exemplary tray-shaped dental treatment device with a gel treatment composition placed in the tray shaped device; FIG. 4B is a cross sectional view of the exemplary tray-shaped dental treatment device of FIG. 2; FIG. 4C is a cross sectional view of the exemplary tray-shaped dental treatment device of FIG. 3; FIG. 4D is a cross sectional view of an exemplary tray-shaped dental treatment device with two separate gel treatment compositions placed in the tray shaped device; FIG. 5 illustrates an exemplary tray-shaped dental treatment device and associated exoskeleton contained within a sealed protective package having a peelable cover; FIG. 6A illustrates a person placing a tray-shaped dental treatment device according to one embodiment of the invention over the upper dental arch; FIG. 6B illustrates a person having placed a tray-shaped dental treatment device according to one embodiment of the invention over the lower dental arch, with a tray-shaped dental treatment device already placed over the upper dental arch; FIG. 7A is a close up cross sectional view of the exemplary tray-shaped dental treatment device of FIG. 6B placed over a persons lower dental arch showing how the V-shaped indentation in the bottom wall is configured for insertion into the depression of a person's molars; and FIG. 7B is a close up cross sectional view of the exemplary tray-shaped dental treatment device of FIG. 6A placed over a person's upper dental arch showing how the curvature of the front side wall and bottom wall account for flaring of a person's incisors. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS I. Introduction and Definitions The inventive tray-shaped dental treatment device includes a moisture-resistant barrier layer having a front side wall and a bottom wall, and a dental treatment composition. In addition, the tray-shaped dental treatment device includes at least one of the following anatomical features to enhance the fit of the device: (1) the bottom wall includes a plurality of cuts positioned to help the bottom wall better conform to abrupt changes in the diameters of a person's teeth, particularly where the bicuspids and canines meet, (2) the bottom wall includes at least one V-shaped or U-shaped indentation configured to be inserted into the depression typically found along the top surfaces of a person's molars, and (3) the front and bottom wall include radii of curvature that account for typical flaring of a patient's incisors. The term “barrier layer”, as used herein, refers to one or more layers of a moisture-resistant material that protect the treatment composition and/or adhesive composition layer from ambient moisture and saliva found within a person's mouth when the tray-shaped dental treatment device is placed over the person's teeth. The barrier layer may also serve to protect the treatment composition and/or adhesive composition from moisture or other contaminants during storage and prior to use. The barrier layer may be in any desired form including, but not limited to, a sheet laminated to a surface of the treatment and/or adhesive composition, a coating applied to the treatment and/or adhesive composition, or a dental treatment tray. The term “substantially solid,” as used herein, refers to a composition that is in a solid or semi-solid condition. One characteristic of “substantially solid” adhesive compositions according to the invention is that they become more adhesive when an exposed surface thereof is moistened with, e.g., saliva or water. When moistened, the surface of the adhesive composition turns into a sticky material that is able to more strongly adhere to teeth compared to a substantially solid adhesive composition that has not been moistened. The composition at the surface may become a viscous liquid, paste or gel, at least temporarily, depending on the amount of moisture that is applied to the surface of the “substantially solid” adhesive composition. Nevertheless, the consistency of the moistened surface can remain “substantially solid” depending on the degree of initial moistening, or it can stiffen and even revert back to being “substantially solid” as the initial quantity of surface moisture diffuses into a remaining portion of the “substantially solid” adhesive composition over time (e.g., during a bleaching procedure in which the composition is protected from saliva and ambient moisture in a person's mouth by a moisture-resistant barrier layer). The term “molecular weight”, as used herein, refers to number average molecular weight expressed in Daltons unless otherwise specified. II. Exemplary Tray-Shaped Dental Treatment Devices A. Barrier Layer The tray-shaped dental treatment device includes a barrier layer. According to one embodiment of the invention, the barrier layer comprises a thin, flexible membrane formed from a moisture-resistant polymer material. In a preferred embodiment, the barrier layer comprises a thin, flexible layer of a mixture of ethyl vinyl acetate and polypropylene. According to another embodiment, it may be formed of a polyolefin or similarly moisture-resistant material, such as wax, metal foil, paraffin, ethylene-vinyl acetate copolymer (EVA), ethylene-vinyl alcohol copolymer (EVAL), polycaprolactone (PCL), polyvinyl chloride (PVC), polyesters, polycarbonates, polyamides, polyurethanes or polyesteramides. Examples of suitable polyolefins for use in making the barrier layer include, but are not limited to, polyethylene (PE), high density polyethylene (HDPE), low density polyethylene (LDPE), ultra low density polyethylene (ULDPE), polypropylene, and polytetrafluoroethylene (PTFE) (e.g., TEFLON). An example of a suitable polyester for use in making the barrier layer includes, but is not limited to, polyethylene terephthalate (PET), an example of which is MYLAR, sold by DuPont. Plasticizers, flow additives, and fillers known in the art can be used as desired to modify the properties of any of the foregoing polymers used to form the barrier layer. B. Dental Treatment Compositions The dental treatment composition may comprise various forms. According to one embodiment, the treatment composition comprises a single continuous bead or layer adjacent to at least a portion of an inner surface of the barrier layer. The treatment composition may comprise a sticky viscous gel, a less viscous gel, a highly viscous putty, or a substantially solid adhesive composition that is less adhesive prior to being moistened with saliva or water but that becomes more sticky and adhesive when moistened. The treatment composition may comprise various forms. According to one embodiment, the treatment composition comprises a single continuous bead or layer adjacent to at least a portion of an inner surface of a barrier layer. The treatment composition may comprise a sticky viscous gel, a less viscous gel, a highly viscous putty, or a substantially solid composition that is less adhesive prior to being moistened with saliva or water but that becomes more sticky and adhesive when moistened. In one embodiment, the treatment device includes a layer or region of a substantially solid adhesive composition and a treatment gel or putty adjacent to at least one of the barrier layer or adhesive composition. The adhesive composition may, in some cases, be formulated so as to provide the same treatment as the separate gel or putty treatment composition, a different treatment, or no treatment. It may provide a protective barrier between the active agent in the gel or putty and the person's gums. It may include a bleaching agent activator in the case where the gel or putty includes a bleaching agent. Prior to being moistened in preparation for or during use, the substantially solid adhesive composition comprises a substantially solid composition. The adhesive composition may comprise a single coherent mass or region, or it may comprise a plurality of coherent masses or regions of a substantially solid adhesive composition. Providing a substantially solid and coherent adhesive composition better maintains the tray-like treatment device against the teeth being bleached. This, in turn, promotes better tooth whitening and reduces irritation to surrounding oral tissues. The dental treatment compositions include at least one tissue adhesion agent, and may include an optional active agent. Following are examples of tissue adhesion agents and optional active agents. 1. Tissue Adhesion Agents The tissue adhesion agent may comprise any known tackifying agent that is substantially non-adhesive, or less adhesive, when treatment composition is substantially solid but which becomes more adhesive to teeth when the treatment composition is moistened with, e.g., water or saliva. A presently preferred tissue adhesion agent is polyvinyl pyrrolidone (PVP). Examples of other suitable tissue adhesion agents include carboxypolymethylene (e.g., CARBOPOL, sold by Novean, Inc.), polyethylene oxide (e.g., POLYOX, made by Union Carbide), polyacrylic acid polymers or copolymers (e.g., PEMULEN, sold by Novean, Inc.), polyacrylates, polyacrylamides, copolymers of polyacrylic acid and polyacrylamide, PVP-vinyl acetate copolymers, carboxymethylcellulose, carboxypropylcellulose, polysaccharide gums, proteins, and the like. Characteristics of substantially solid adhesive treatment compositions in particular, and these and other tissue adhesion agents are disclosed in U.S. patent application Ser. No. 10/446,235, filed May 27, 2003, and titled TRAY-LIKE DENTAL BLEACHING DEVICES HAVING A BARRIER LAYER AND A SUBSEQUENTLY SOLID BLEACHING COMPOSITION, and U.S. patent application Ser. No. 10/446,471, filed May 27, 2003, and titled SUBSTANTIALLY SOLID DENTAL BLEACHING COMPOSITION IN A TRAY-LIKE CONFIGURATION, both of which are hereby incorporated by reference with respect to their disclosure of substantially solid adhesive compositions and tissue adhesion agents. The amount of tissue adhesion agent in the dental treatment composition often depends on whether the composition is a gel, a putty, or a substantially solid adhesive composition. According to one embodiment, the one or more tissue adhesion agents are included in an amount in a range of about 10% to about 90% by weight of the treatment composition (exclusive of any bound water or other solvent), more preferably in a range of about 20% to about 80% by weight of the treatment composition, and most preferably in a range of about 40% to about 75% by weight of the treatment composition. 2. Active Agents One or more active agents may be included in the dental treatment composition. Examples of various active agents include dental bleaching agents, desensitizing agents, remineralizing agents, antimicrobial agents, antiplaque agents, anti-tartar agents, or other medicaments. A common dental bleaching agent that is known to bleach teeth and that has been found to be safe for oral use is hydrogen peroxide. However, hydrogen peroxide does not itself exist free in nature, but only as an aqueous solution or as a complex. Preferred dental bleaching agents comprise complexes of hydrogen peroxide because they are more stable than aqueous hydrogen peroxide, which tends to be unstable when heated, especially when water is removed by evaporation. Non-limiting examples of complexed hydrogen peroxide include carbamide peroxide and metal perborates. Other bleaching agents that can be used to bleach teeth include, but are not limited to, metal percarbonates, peroxides, chlorites, and hypochlorites, peroxy acids, and peroxy acid salts. If present, the one or more bleaching agents are preferably included in an amount in a range of about 5% to about 80% by weight of the treatment composition, more preferably in a range of about 10% to about 60% by weight of the treatment composition, and most preferably in a range of about 20% to about 50% by weight of the treatment composition. As mentioned, other optional active agents may be included. Examples of desensitizing agents include potassium nitrate, other potassium salts, citric acid, citrates, and sodium fluoride. These and other desensitizing agents are disclosed in U.S. patent application Ser. No. 10/637,237, filed Aug. 8, 2003, and titled SUBSTANTIALLY SOLID DESENSITIZING COMPOSITIONS AND DEVICES HAVING A TRAY-LIKE CONFIGURATION AND METHODS OF MANUFACTURING AND USING SUCH COMPOSITIONS AND DEVICES, which is hereby incorporated by reference with respect to its disclosure of desensitizing agents. Examples of remineralizing agents include sodium fluoride, stannous fluoride, sodium monofluorophosphate, and other fluoride salts. Examples of antimicrobial agents include chlorhexidine, triclosan, and tetracycline. Examples of antiplaque and anti-tartar agents include pyrophosphate salts. These and additional medicaments that may be included as optional active agents are disclosed in U.S. patent application Ser. No. 10/646,484, filed Aug. 22, 2003, and titled COMPOSITIONS AND DEVICES HAVING A TRAY-LIKE CONFIGURATION FOR DELIVERING A MEDICAMENT AND METHODS OF MANUFACTURING AND USING SUCH COMPOSITIONS AND DEVICES, which is hereby incorporated by reference with respect to its disclosure of active agents. 3. Other Components The dental treatment composition may include other components as desired to yield a final composition having desired properties. Examples of other components include, but are not limited to, plasticizers and humectants (e.g., glycerin, sorbitol, and polyethylene glycol), volatile solvents (e.g., water and alcohols, such as ethanol), bleaching agent stabilizers (e.g., EDTA and alkyl sulfates), bleaching agent activators (e.g., metals and metal compounds) neutralizing agents (e.g., sodium hydroxide), thickening agents (e.g., fumed silica), flavorants, sweeteners, and the like. Additional treatment compositions and their components are disclosed in U.S. patent application Ser. No. 10/701,788, filed Nov. 4, 2003, and titled PRE-SHAPED DENTAL TRAYS AND TREATMENT DEVICES AND METHODS THAT UTILIZE SUCH DENTAL TRAYS, and U.S. patent application Ser. No. 10/692,117, filed Oct. 22, 2003, and titled BLEACHING COMPOSITIONS AND DEVICES HAVING A SOLID ADHESIVE LAYER AND BLEACHING GEL ADJACENT THERETO, both of which are hereby incorporated by reference with respect to their disclosure of treatment compositions. C. Characteristics of Tray-Shaped Dental Treatment Devices The tray-shaped dental treatment devices include at least one of the following anatomical features to enhance the fit of the tray-shaped dental treatment device: (1) the bottom wall includes a plurality of cuts positioned to help the bottom wall better conform to abrupt changes in the diameters of a person's teeth, particularly where the bicuspids and canines meet, (2) the bottom wall includes at least one V-shaped or U-shaped indentation configured to be inserted into the depression typically found along the top surfaces of a person's molars, and (3) the front and bottom wall include radii of curvature that account for typical flaring of a patient's incisors. FIG. 1A illustrates a perspective view of an exemplary tray-shaped dental treatment device 100, along with an associated exoskeleton 100a having a handle 103a. The device 100 of FIG. 1A is sized and configured for placement over a person's upper dental arch. In the illustrated embodiment, the tray-shaped dental treatment device includes a substantially solid adhesive composition 101 which covers all the interior surfaces of the front wall 102 and the bottom wall 104. The bottom wall 104 includes a plurality of cuts positioned to help the bottom wall better conform to abrupt changes in the diameters of a person's teeth, particularly where the bicuspids and canines meet. The cuts help to compensate for the fact that bicuspids are significantly thicker than canines by allowing for an abrupt discontinuity in the bottom wall 104 of the treatment device 100. Without these cuts the bottom wall 104 would be harder to conform to the canines since the adjacent bicuspids would tend to push the bottom wall 104 away from the canines, thus potentially dislodging the bottom wall 104 in this region. These and any other cuts within the bottom wall 104 may also help compensate for differences between the inner and outer radii of the dental arch generally defined by the inner and outer tooth surfaces. The cuts in the bottom wall 104 may extend the full width of the bottom wall 104. In the illustrated embodiment, the cuts comprise notches 106. Notches 106 allow the bottom wall 104 to more freely spread open or compress without catching or overlapping other portions of the bottom wall 104. Notches 106 are positioned to help the bottom wall better conform to abrupt changes in the diameter of a person's teeth, particularly where the bicuspids and the canines meet. In the illustrated embodiment, the vertex of each notch 106 initially opens at about 10°. Each notch 106 spreads substantially wider before reaching the inside edge of bottom wall 104. In the illustrated embodiment, except for the vertex, the notches 106 do not include any sharp corners. The corners are preferably rounded so as to provide a more comfortable fit. The bottom wall also includes a notch 108 near the front of the bottom wall 104 of the device 100. Optional notch 108 allows the tray-shaped dental treatment device 100 to more easily spread open or compress in the area of the incisors. This is helpful in allowing the bottom wall 104 to more easily conform to differently-sized dental arches. As illustrated, notch 108 may also have rounded corners. In the illustrated embodiment, the bottom wall 104 also includes two V-shaped indentations 110 configured to be inserted into the depression typically found along the top surfaces of a person's left and right molars. Such a feature provides a tray-shaped dental treatment device that better conforms to the person's teeth, resulting in a more comfortable fit, as further illustrated in FIG. 7A. FIG. 1B illustrates a perspective view of an exemplary tray-shaped dental treatment device 100′ along with an associated exoskeleton 100a′ having a handle 103a′. The tray-shaped dental treatment device 100′ is sized and configured for placement over a person's lower dental arch. In the illustrated embodiment, the tray-shaped dental treatment device 100′ includes an adhesive composition 101′. The tray-shaped dental treatment device includes a barrier layer of moisture resistant material having a front side wall 102′ and a bottom wall 104′. Bottom wall 104′ includes notches 106′ in the bottom wall 104′ positioned so as to help the bottom wall 104′ better conform to abrupt changes in the diameter of a person's teeth, particularly where the bicuspids and canines meet. Bottom wall 104′ further includes optional notch 108′, which allows the tray-shaped dental treatment device 100′ to more easily spread open or compress in the area of the incisors so as to more easily conform to differently-sized dental arches. Finally, the bottom wall 104′ also includes two V-shaped indentations 110′ configured to be inserted into the depression typically found along the top surfaces of a person's left and right molars. FIG. 2 illustrates a tray-shaped dental treatment device 200 having a moisture-resistant barrier layer 212 having a front side wall 202 and a bottom wall 204. The device 200 is held within exoskeleton 200a. The tray-shaped dental treatment device 200 also includes a substantially solid adhesive composition 201 covering the front side wall 202. The adhesive composition 201 includes an exterior surface disposed adjacent to an interior surface of the barrier layer 212 and an interior surface designed to directly contact a person's teeth when the tray-shaped dental treatment device 200 is in use. Bottom wall 204 includes notches 206 in the bottom wall 204 positioned so as to help the bottom wall 204 better conform to abrupt changes in the diameter of a person's teeth, particularly where the bicuspids and canines meet. Bottom wall 204 also includes an optional notch 208, which allows the tray-shaped dental treatment device 200 to more easily spread open or compress in the area of the incisors so as to more easily conform to differently-sized dental arches. The bottom wall 204 also includes two V-shaped indentations 210 configured to be inserted into the depressions typically found along the top surfaces of a person's left and right molars. FIG. 3 illustrates a tray-shaped dental treatment device 300 having a moisture-resistant barrier layer 312 having a front side wall 302 and a bottom wall 304. The device 300 is held within exoskeleton 300a. A substantially solid adhesive composition 301 is disposed adjacent to the front side wall 302. Tray-shaped dental treatment device 300 also includes a gel treatment composition 314 adjacent to at least one of the adhesive composition 301 or the barrier layer 312. Bottom wall 304 includes notches 306 in the bottom wall 304 positioned so as to help the bottom wall 304 better conform to abrupt changes in the diameter of a person's teeth, particularly where the bicuspids and canines meet. Bottom wall 304 also includes an optional notch 308, which allows the tray-shaped dental treatment device 300 to more easily spread open or compress in the area of the incisors so as to more easily conform to differently-sized dental arches. The bottom wall 304 also includes two V-shaped indentations 310 configured to be inserted into the depressions typically found along the top surfaces of a person's left and right molars. FIGS. 4A-4D illustrate cross sections of various other exemplary tray-shaped dental treatment devices. FIG. 4A illustrates a cross section of a tray-shaped dental treatment device 400 including a front side wall 402 and a bottom wall 404. A gel treatment composition 414 is positioned adjacent to both the front side wall 402 and the bottom wall 404. FIG. 4B illustrates a cross section of a tray-shaped dental treatment device 400b including a front side wall 402b and a bottom wall 404b. A substantially solid adhesive composition 401b is positioned adjacent to both the front side wall 402b and the bottom wall 404b. FIG. 4C illustrates a cross section of a tray-shaped dental treatment device 400c including a front side wall 402c and a bottom wall 404c. A substantially solid adhesive composition 401c is positioned adjacent to both the front side wall 402c and the bottom wall 404c, while a gel treatment composition 414c is positioned adjacent to the substantially solid adhesive composition 401c. FIG. 4D illustrates a cross section of a tray-shaped dental treatment device 400d including a front side wall 402d and a bottom wall 404d. A gel treatment composition 414d is positioned adjacent to both the front side wall 402d and the bottom wall 404d, while a second gel treatment composition 415d is positioned adjacent to the front side wall 404d, near the top. Second gel treatment composition 415d may be a treatment composition intended to provide no treatment, and to contact the gums. Such a composition preferably contains no dental bleaching agent which otherwise may irritate the soft tissue surrounding the teeth (e.g. gingival tissue). Second gel treatment composition 415d reduces or prevents contact between gel treatment composition 414d and the person's soft tissue. In order to protect a tray-shaped dental treatment device according to the invention from contaminants during storage and prior to use, the tray-shaped dental treatment device can be packaged within a sealed container or package. As illustrated in FIG. 5, the tray-shaped dental treatment device 200, along with an associated exoskeleton 200a can be sealed within a protective package 516 that includes a rigid support layer 518 and a peelable cover 520. Although illustrated with tray-shaped dental treatment device 200 and associated exoskeleton 200a, any embodiment of the tray-shaped dental treatment device with or without an associated exoskeleton can be sealed within a protective package. When it is desired to use the tray-shaped dental treatment device 200, the peelable cover 520 is removed and the bleaching device 200 is removed or separated from the support layer 518. In addition to, or instead of, the protective package 516, the tray-shaped dental treatment device 200 may alternatively include a removable protective layer (not shown) that is temporarily placed adjacent to the interior surface of the adhesive composition 201 and/or a gel or putty treatment composition. When it is desired to use the tray-shaped dental treatment device 200, the removable protective layer is removed so as to expose the interior surface of the adhesive composition 201 and/or other treatment composition. In addition, prior to using the tray-shaped dental treatment device 200, a gel or putty treatment composition may be applied to the inside of the device 200, as shown in FIGS. 3, 4A, 4C, or 4D. In general, the thickness of the adhesive composition layer and the barrier layer can be adjusted to yield a tray-shaped dental treatment device having a desired strength and flexibility. In order for the barrier layer to remain flexible so as to conform to a person's teeth, the barrier layer will generally have a thickness ranging from about 0.025 mm to about 1.5 mm. When present, the substantially solid adhesive composition will generally have a thickness ranging from about 0.1 mm to about 3 mm. The thickness of the adhesive composition can also be selected depending on the intended duration of each bleaching session. In general, increasing the thickness of the adhesive composition layer where the adhesive composition includes a dental bleaching agent will provide a longer or more sustained release of active dental bleaching agent. By way of example, for short wear times, the adhesive composition layer including a dental bleaching agent will preferably have a thickness ranging from about 0.1 mm to about 0.5 mm. For intermediate wear times, the adhesive composition layer including a dental bleaching agent will preferably have a thickness ranging from about 0.5 mm to about 2 mm. For professional use and for overnight bleaching, the adhesive composition layer having a dental bleaching agent will preferably have a thickness ranging from about 2 mm to about 3 mm. III. Exemplary Methods of Making Tray-Shaped Dental Treatment Devices According to one embodiment, the tray-shaped dental treatment device includes a moisture-resistant barrier layer having a front side wall and a bottom wall, a dental treatment composition, and at least one of the anatomical features discussed above to enhance the fit of the tray-shaped dental treatment device. According to one method of manufacturing one exemplary device, an adhesive composition is made by first forming a flowable composition that is later dried to form a substantially solid adhesive composition. This may be performed by heating or otherwise causing one or more volatile solvents to be driven off by evaporation, thus leaving behind a substantially solid composition. The drying process may be performed before or after the adhesive composition is placed into contact with the barrier layer. According to one embodiment, tray-shaped dental treatment devices can be made by spreading a flowable adhesive composition onto the surface of a large or continuous polymeric sheet. The polymeric sheet and adhesive composition are then placed into a forced air oven, other appropriate desiccation device, or allowed to dry in ambient conditions. Drying the sheet and adhesive composition drives off a substantial portion of the ethanol or other solvent used to form the flowable adhesive composition. Removal of the volatile solvent yields a substantially solid adhesive composition. Thereafter, individual tray-shaped dental treatment devices can be molded, such as by vacuum forming, pressing or stamping from the coated polymeric sheet and then separated into individual dental treatment devices suitable for placement over a person's teeth. Alternatively, a flowable adhesive composition or a substantially solid adhesive composition can be molded or shaped into a desired tray-like configuration. Thereafter, a barrier layer may be attached or applied to an outer surface of the adhesive composition layer. In this embodiment, the barrier layer may initially comprise a flowable barrier material or precursor that is later cured or hardened, such as by removing a solvent by evaporation, by chemical or light curing, or by cooling a thermoplastic melt. In yet another embodiment of the invention, a barrier layer having a front side wall and a bottom wall can be coated with a flowable adhesive composition. The adhesive composition is then heated together with the barrier layer or otherwise allowed to dry in order to form a substantially solid adhesive composition. This process can be performed during commercial manufacture of the tray-shaped dental treatment device or by an end user. Sticky viscous gels, less viscous gels, and/or highly viscous putties may be manufactured separate from the barrier layer. They may be applied to the barrier layer or an adhesive composition prior to packaging, if desired. Alternatively, the tray-shaped dental treatment devices can be provided with a separate gel or putty which the end user may apply. The tray-shaped dental treatment devices may be placed within an optional exoskeleton during the manufacturing process prior to packaging, if desired. Alternatively, the tray-shaped dental treatment devices may be provided with a separate exoskeleton, or without an exoskeleton, as desired. IV. Exemplary Methods of Using Tray-Shaped Dental Treatment Devices The tray-shaped dental treatment devices according to the invention can be designed to be worn for any desired time period. Increasing the concentration of dental bleaching agent in the treatment composition(s) generally reduces the bleaching time required to effect bleaching. Nevertheless, due to the extremely comfortable fit between the inventive tray-shaped dental treatment devices and the person's teeth, it is possible to wear such devices for extended periods of time in order to ensure more uniform bleaching. Especially with respect to tray-shaped dental treatment devices including a substantially solid adhesive composition layer, they may be designed to be worn while performing normal daily activities, such as talking, eating, drinking, smoking, coughing, smiling, frowning, grimacing, or while sleeping. This greatly decreases their intrusiveness into everyday activities compared to conventional bleaching strips, which do not reliably adhere to teeth, or intrusive bleaching devices such as large, bulky bleaching dental appliances. Tray-shaped dental treatment devices according to the invention may be worn over a person's upper dental arch, lower dental arch, or both simultaneously. The ability to reliably and comfortably wear tray-shaped dental treatment devices over the upper and lower dental arches simultaneously is another departure from bleaching strips, which are not recommended for use in bleaching the upper and lower dental arches at the same time. FIG. 6A illustrates a person 622 placing a tray-shaped dental treatment device 600 over the person's upper dental arch using an exoskeleton as a support. FIG. 6B illustrates the person 622 placing a tray-shaped dental treatment device 600‘over the person’s lower dental arch after having placed the tray-shaped dental treatment device 600 over the upper dental arch. It will be appreciated, however, that the tray-shaped dental treatment devices can be placed over a person's upper and lower dental arches in any desired order. The tray-shaped dental treatment devices 600 and 600′ include a plurality of notches 606 and 606′, respectively, and V-shaped indentations 610 and 610′, respectively, in the bottom wall. FIGS. 6A and 6B illustrate how the notches 606, 606′ in the bottom wall help the bottom wall better conform to abrupt changes in the diameter of a person's teeth where the bicuspids and canines meet. FIG. 7A is a close up cross sectional view illustrating how the V-shaped indentation 610′ in the bottom wall 604′ of tray-shaped dental treatment device 600′ is configured for insertion into the depression in the lower molar 624′. As seen, molar 624′ includes a depression 626′ into which V-shaped indentation 610′ is configured to be inserted. This results in better conformity between the tray-shaped dental treatment device 600′ and the molar 624′, even when downward pressure is applied to the bottom wall 604′. In the absence of such indentations, the bottom wall 604′ of the treatment device 600′ may have a tendency to span the molar 624′ like a bridge between the generally higher outer edges, thereby leaving a gap between the bottom wall 604′ and the surface of the molar 624′ between the outer edges. Permitting such a gap may inhibit or prevent bleaching of the depressed molar surfaces. Moreover, a bottom wall 604′ that is stretched between the outer surfaces so as to leave a gap over the molar depressions may result in inadvertent dislodgment of the treatment device 600′ when the upper and lower molars are brought together. For example, if the bottom wall 604′ of a treatment device 600′ is pushed into the molar depression 626′ by the opposing molars, the front and/or bottom side walls 602′ and 604′, respectively, may be pulled down across the tooth surfaces to compensate for this effective lengthening of the bottom wall 604′ in the vicinity of the patient's molars. FIG. 7B is a close up cross sectional view illustrating how the curvature of the front side wall 602 and bottom wall 604 account for flaring of the person's incisors 628. A typical person's incisors are not vertical. Rather, they typically flare outwards slightly. The front side wall 602 and bottom wall 604 may have different radii in order to compensate for the general flaring out of a person's incisors toward the incisal edges. Due to such flaring the diameter of a person's dental arch at the incisal edges is generally greater than the diameter at the gingival margin. Thus the part of the treatment device 600 corresponding to the incisal edges near a person's incisor 628 may advantageously have a larger radius than the part of the treatment device 600 corresponding to the gingival margin. This helps provide for a better fit of the treatment device 600 over a person's incisors 628. To remove the tray-shaped dental treatment device, a user can pry open a corner of the barrier layer using a fingernail or rigid tool and then pull the remainder off. Any residual adhesive composition or gel or putty treatment composition that remains adhered to the person's teeth can be removed by washing or flushing water over the person's teeth, and/or by brushing. Although the adhesive compositions are very adhesive to teeth when protected from excessive moisture, they can be formulated to quickly breakdown and dissolve when flushed with excess water and/or by gentle mechanical action (e.g., brushing). The tray-shaped dental treatment devices can be worn for as little as a few minutes and as long as several hours. By way of example, not limitation, a typical bleaching session of fast duration may last from about 10 to about 30 minutes. A bleaching session of intermediate duration may last from about 30 minutes to about 2 hours. A bleaching session of long duration, including professional bleaching or overnight bleaching while a person is sleeping, may last from about 2 hours to about 12 hours. Bleaching sessions may be repeated as many times as are needed to obtain a desired degree of whitening. In some cases, a clinical whitening effect has been observed after only 1-3 whitening sessions. A typical bleaching regimen will preferably include 1-20 bleaching sessions, more preferably 2-15 bleaching sessions, and most preferably 3-10 bleaching sessions. V. Dental Bleaching Kits For convenience of use, multiple tray-shaped dental treatment devices may be packaged together and sold as a kit. In one embodiment, the number treatment devices provided with each kit will equal the number of sessions that represent a prescribed bleaching regimen. To efficiently utilize the space within a kit package, multiple tray-shaped dental treatment devices can be stacked or interested together. The devices can be sealed collectively or individually as desired. A protective package 516 is depicted in FIG. 5. The bleaching devices may optionally contain a removable protective layer on an interior surface to protect the adhesive composition from contamination or moisture. It is within the scope of the invention to provide exoskeletons, barrier layers, gel or putty treatment compositions, and/or adhesive compositions that are initially separate and that are brought together by the end user. For example, the adhesive composition may be a dry insert that is placed into a tray-like barrier layer, with or without actually adhering the adhesive composition to the barrier layer. Alternatively, a flowable adhesive composition can be placed within a tray-like barrier layer and allowed to dry prior to placement of the finished tray-shaped dental treatment device over the person's teeth. VI. EXAMPLES OF THE PREFERRED EMBODIMENTS Following is an example of a tray-shaped dental treatment device that has been formulated and manufactured according to the invention. Additional examples of treatment compositions and barrier layers that may be used are disclosed in U.S. patent application Ser. No. 10/446,235, filed May 27, 2003 and titled TRAY-LIKE DENTAL BLEACHING DEVICES HAVING A BARRIER LAYER AND A SUBSEQUENTLY SOLID BLEACHING COMPOSITION, hereby incorporated by reference with respect to examples of barrier layers and treatment compositions. The exemplary formulations and manufacturing conditions are given by way of example, and not by limitation, in order to illustrate tray-shaped dental treatment devices that have been found to be useful for bleaching a person's teeth. Unless otherwise indicated, all percentages are by weight. EXAMPLE 1 An initially flowable adhesive composition suitable for use in manufacturing a substantially solid adhesive composition was formed by mixing together the following components: Ethanol 31.95% Water 10% Polyvinyl Pyrrolidone (M.W. = 1.3 million) 27% Polyvinyl Pyrrolidone (M.W. of about 60,000) 10% Sodium Laurel Sulfate 0.5% Glycerine 15% Sucralose 25% solution 0.5% Peach Flavor 4% Potassium Nitrate 0.8% Sodium Fluoride 0.25% The resulting adhesive composition was spread over the surface of a large flat sheet formed of 80% ethyl vinyl acetate and 20% polypropylene. The EVA/PP sheet had a thickness of about 0.15 mm. The adhesive composition was spread using a skreeding device. The coated sheet was heated in a forced air oven until the adhesive composition dried. The coated sheet was removed from the oven and inspected. The adhesive composition had dried sufficiently so as to form a substantially solid layer on the surface of the polymer sheet. The adhesive composition was dry to the touch, but became very sticky when touched by a wet object. After drying, the adhesive composition film was reduced to approximately one-third of its original thickness when wet. The coated sheet was thermoformed into tray-shaped devices with the dry adhesive composition on the inside surface of the devices. Individual tray-shaped devices were cut out using dye cutting tools. A laser could alternatively be used for cutting. The tray-shaped devices included a front side wall, a bottom wall, a plurality of notches formed in the bottom wall so as to help the bottom wall better conform to abrupt changes in the diameter of a person's teeth, particularly where the bicuspids and canines meet, two V-shaped indentations in the bottom wall configured to be inserted into the depression typically found in a persons left and right molars, and a curvature of the front side wall and bottom wall that accounts for typical flaring of a person's incisors. A bleaching gel treatment composition for use with the tray-shaped devices was prepared by mixing together the following components: Water 22.5% EDTA Disodium 0.1% Carbamide Peroxide 18.5% Sucralose 25% solution 0.75% Glycerine 41.6% Carbopol 974 5.3% Sodium Hydroxide 50% solution 2.25% Polyvinyl Pyrrolidone (M.W. = 1.3 million) 2% Carboxymethyl Cellulose 4% Watermelon Flavor 3% The tray-shaped devices were placed in a holding device, and a bead of bleaching gel treatment composition was spread along the front side wall of the bleaching devices. Each tray-shaped device was then transferred to an exoskeleton. The tray-shaped devices were tested by placing them over a person's teeth. The residual saliva present on the tooth surfaces moistened the exposed surface of the adhesive composition and caused it to become sticky and very adhesive to teeth almost immediately. The tray-shaped devices were pressed against the teeth, which caused them to conform to the natural irregularities of the dental arch and adhere firmly against the teeth. The plurality of notches formed in the bottom wall helped the bottom wall better conform to abrupt changes in the diameter of a person's teeth, particularly where the bicuspids and canines meet. The two V-shaped indentations in the bottom wall were received within the depression in the left and right molars, and the curvature of the front side wall and bottom wall resulted in a good fit against the person's outwardly flared incisors. The tray-shaped devices were worn for varying time periods ranging from several minutes to several hours without becoming dislodged. In some cases a noticeable bleaching effect was detected after just one bleaching session (e.g., a 2-hour bleaching session). In all cases, noticeable bleaching was detected after 1-3 bleaching sessions. The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. The Field of the Invention The present invention is in the field of dental tray shaped devices used to provide a desired dental treatment to a person's teeth. The device can be used for dental treatments such as bleaching, administration of fluoride, or application of other medicines. 2. The Relevant Technology Virtually all people desire white or whiter teeth. To achieve this goal, people have veneers placed over their teeth or have their teeth chemically bleached. A common bleaching method involves the use of a dental tray that is custom-fitted to a person's teeth and that is therefore comfortable to wear. One type of customized tray is made from a stone cast of a person's teeth. Another is customized directly using a person's teeth as a template (e.g., “boil-and-bite” trays). Non-customized trays that approximate the shapes and sizes of a variety of users' dental arches have also been used. A dental bleaching composition is placed into the tray and the tray placed over the person's teeth for a desired period of time. Another bleaching method involves painting a bleaching composition directly onto a person's teeth. A perceived advantage of paint-on bleaching is that it eliminates the need for a dental tray. The main disadvantage of a paint-on bleaching composition is that it remains directly exposed to the person's saliva and disruptive forces found in a person's mouth. As a result, a significant portion of the bleaching composition does not remain on the teeth where bleaching is desired. Some or all of the composition can dissolve away into the person's saliva and/or be transferred to adjacent oral tissues, potentially irritating soft oral tissues. Another tooth bleaching method involves placing a flexible bleaching strip over a user's tooth surfaces. Conventional bleaching strips comprise a flexible plastic strip coated with a dental bleaching gel of moderate viscosity and relatively low stickiness on the side of the strip facing the user's teeth. To install the bleaching strip, a portion of the bleaching strip is placed over the front surfaces of the user's teeth, and the remainder is folded around the occlusal edges of the teeth and against a portion of the lingual surfaces. Like paint-on bleaching compositions, this procedure does not require the use of dental trays. Unlike paint-on bleaching compositions, bleaching strips include a plastic barrier that, at least in theory, keeps the dental bleaching gel from diffusing into the user's mouth. In reality, because of the generally poor adhesion of bleaching strips to the user's teeth, coupled with their generally flimsy nature, it is often difficult for the user to maintain the bleaching strip in its proper position for the recommended time. Conventional bleaching strips are prone to slip off the teeth as a result of even minimal movement of the user's mouth, jaw or tongue. Indeed, it is recommended that the user not eat, drink, smoke or sleep while wearing the bleaching strip. In practice, it is difficult to talk or smile while properly maintaining the bleaching strip in the correct position. Even if a user successfully maintains a conventional bleaching strip in its proper position during the recommended bleaching period, the bleaching gel often diffuses into the person's saliva, potentially causing a poor taste in the user's mouth and possibly discomfort to soft oral and throat tissues. The tendency of the bleaching gel to diffuse into the user's mouth can be accelerated through even minimal shifts of the bleaching strip over the user's teeth, with each shift potentially causing bleaching gel that remains adhered to the user's teeth, but not covered by the plastic strip, to be exposed to saliva in the user's mouth. In some cases, the bleaching strip can become so dislodged or mangled that it must be removed by the user and replaced with a fresh bleaching strip to complete the recommended bleaching time. This multiplies the cost and hassle of using conventional bleaching strips. In practical terms, the use of conventional bleaching strips can greatly inhibit even the simplest of activities that involve movement of the user's mouth or tongue, such as talking, smiling, making other facial expressions, or even swallowing (which normally occurs subconsciously throughout the day). Indeed, the time when a person's mouth and tongue are the least prone to move is at night while the person is sleeping. Unfortunately, it is recommended that conventional bleaching strips not be used while sleeping, presumably to prevent accidental choking on an inadvertently dislodged bleaching strip. This confirms the tendency of conventional bleaching strips to easily dislodge from a user's teeth. Ultimately, the main impediment to successful bleaching is the failure of users to complete the prescribed bleaching regimen. If the bleaching apparatus is difficult to install over a person's teeth, requires numerous repetitions to achieve observable results, or is uncomfortable to wear, the user may simply give up and prematurely abort the prescribed bleaching regimen. Thus, even if dental bleaching is possible using a particular bleaching apparatus or method, it is less likely to occur if the inadequacies of the bleaching apparatus or method cause a user to become discouraged before desired results are attained. In view of the foregoing, there is an ongoing need for improved bleaching apparatus and methods that are simple and easy to use and that reliably remain in position over the user's teeth so as to reduce diffusion of bleaching composition into a user's oral cavity. Such improvements would be expected to improve or encourage compliance by the user. | <SOH> BRIEF SUMMARY OF THE PREFFERED EMBODIMENTS <EOH>The present invention generally relates to improved dental treatment devices used to treat (e.g., bleach) a person's teeth. The inventive tray-shaped device includes a front side wall and a bottom wall. In addition, the tray-shaped device includes at least one of the following features to enhance anatomical fit: (1) the bottom wall includes a plurality of cuts positioned to help the bottom wall better conform to abrupt changes in the diameters of a person's teeth, particularly where the bicuspids and canines meet, (2) the bottom wall includes at least one V-shaped or U-shaped indentation configured to be inserted into the depression typically found along the top surfaces of a person's molars, and (3) the front and bottom wall include radii of curvature that account for typical flaring of a patient's incisors. In one embodiment of a treatment device according to the invention, the bottom wall includes a cut on either side of the device approximately corresponding to the intersection of a person's canines and bicuspids. The cuts help to compensate for the fact that bicuspids are significantly thicker than canines by allowing for an abrupt discontinuity in the bottom wall of the treatment device. Without these cuts the bottom wall would be harder to conform to the canines since the adjacent bicuspids would tend to push the bottom wall away from the canines, thus potentially dislodging the bottom wall in this region. These and any other cuts within the bottom wall may also help compensate for differences between the inner and outer radii of the dental arch generally defined by the inner and outer tooth surfaces. In another embodiment of a treatment device according to the invention, the bottom wall may include V-shaped or U-shaped indentations in the region of a person's molars that cause the bottom wall to better conform to the depression normally found in molars. In the absence of such V-shaped or U-shaped indentations, the bottom wall of the treatment device may have a tendency to span the molars like a bridge between the generally higher outer edges, thereby leaving a gap between the bottom wall and the surface of the molars between the outer edges. Permitting such a gap may inhibit or prevent bleaching the depressed molar surfaces. Moreover, a bottom wall that is stretched between the outer surfaces so as to leave a gap over the molar depressions may result in inadvertent dislodgment of the treatment device when the upper and lower molars are brought together. For example, if the bottom wall of a treatment device is pushed into the molar depression by the opposing molars, the front and/or bottom side walls may be pulled down across the tooth surfaces to compensate for this effective lengthening of the bottom wall in the vicinity of the molars. In another embodiment of a treatment device according to the invention, the front and bottom walls may have different radii in order to compensate for the general flaring out of a person's incisors toward the incisal edges. Due to such flaring the diameter of a person's dental arch at the incisal edges is generally greater than the diameter at the gingival margin. Thus the part of the treatment device corresponding to the incisal edges near a person's incisors may advantageously have a larger radius than the part of the treatment device corresponding to the gingival margin. This helps provide better fit of the treatment device over a person's tooth surfaces. The treatment composition may comprise various forms. According to one embodiment, the treatment composition comprises a single continuous bead or layer adjacent to at least a portion of an inner surface of a barrier layer. The treatment composition may comprise a sticky viscous gel, a less viscous gel, a highly viscous putty, or a substantially solid composition that is less adhesive prior to being moistened with saliva or water but that becomes more sticky and adhesive when moistened. In another embodiment, the treatment device includes a layer or region of a substantially solid adhesive composition and a treatment gel or composition adjacent to at least one of the barrier layer or adhesive composition. The adhesive composition may, in some cases, be formulated so as to provide the same treatment as the separate treatment composition, a different treatment, or no treatment. It may provide a protective barrier between the active agent in the treatment composition or gel and the person's gums. It may include a bleaching agent activator in the case where the treatment composition includes a bleaching agent. According to one embodiment, the tray-shaped device includes a barrier layer made of a moisture resistant material. According to one embodiment, the barrier layer comprises a thin, flexible membrane formed from a moisture-resistant polymer material. It is within the scope of the invention to provide barrier layers having any desired thickness or rigidity. In one embodiment, the barrier layer comprises a mixture of ethyl vinyl acetate and polypropylene. The treatment and/or adhesive compositions may include any desired active agent, including, but not limited to, dental bleaching agents, desensitizing agents, remineralizing agents, antimicrobial agents, antiplaque agents, anti-tartar agents, or other medicaments. They also include at least one tissue adhesion agent. A non-limiting example of a suitable tissue adhesion agent is polyvinyl pyrrolidone (PVP). The treatment and/or adhesive: compositions may include other components as desired to yield a final composition having desired properties. Examples of other components include, but are not limited to, plasticizers and humectants (e.g., glycerin, sorbitol, and polyethylene glycol), volatile solvents (e.g., water and alcohols), bleaching agent stabilizers (e.g., EDTA and alkyl sulfates), bleaching agent activators (e.g., metals and metal compounds), neutralizing agents, thickening agents (e.g., fumed silica), flavorants, sweeteners, and the like. The size and shape of the treatment devices according to the invention can be tailored to readily fit a person's upper or lower dental arch. They may also be tailored to fit person's having differently sized or shaped dental arches. The treatment devices are advantageously designed so as to substantially cover the front and lingual surfaces of the teeth and/or gums to be treated. The treatment devices are advantageously flexible and adhesive so as to readily conform to a wide variety of differently-sized teeth and dental arches. The treatment devices according to the invention can be designed to be worn for any desired time period. Increasing the concentration of active agent used generally reduces the required treatment time. Nevertheless, due to the extremely comfortable fit between the inventive treatment devices and the person's teeth, it is possible to wear such devices for extended periods of time. Treatment devices according to the invention can be designed to be worn while, e.g., talking, sleeping, eating, drinking, smiling, frowning, grimacing, yawning, coughing, smoking, or making virtually any facial expression or mouth contortion. This greatly decreases their intrusiveness into everyday activities compared to conventional bleaching strips, which do not reliably adhere to teeth, or intrusive bleaching devices such as large, bulky bleaching dental appliances. The treatment devices can be designed to be worn for as little as a few minutes or as long as several hours. By way of example, not limitation, a typical treatment session of fast duration may last from about 10 to about 30 minutes. A treatment session of intermediate duration may last from about 30 minutes to about 2 hours. A treatment session of long duration, including professional or overnight treatment while a person is sleeping, may last from about 2 hours to about 12 hours. Treatment sessions may be repeated as many times as are needed to obtain a desired result. In the case of tooth bleaching, a clinical whitening effect has been observed after only 1-3 whitening sessions. A typical bleaching regimen will preferably include 1-20 bleaching sessions, more preferably 2-15 bleaching sessions, and most preferably 3-10 bleaching sessions. According to one embodiment, the treatment device may include an associated supporting structure, such as an exoskeleton, prior to use. An exoskeleton may be particularly useful where the barrier layer is very thin and flexible. The exoskeleton may have the same configuration as the treatment device so as to receive and support the front and bottom walls of the treatment device. The exoskeleton can provide additional support and ease of placement to the treatment device while positioning the device over a person's teeth. In one embodiment, the exoskeleton includes a handle to facilitate gripping and maneuverability of the exoskeleton while placing the treatment device over the teeth. Once positioned, the exoskeleton can be removed so as to leave the treatment device in place over the teeth. For convenience of use, multiple treatment devices may be packaged together and sold as a kit. In one embodiment, the number of treatment devices provided with each kit can equal the number of sessions that represent a prescribed treatment regimen. The treatment devices can be sealed collectively or individually as desired. They may contain a removable protective layer on their interior surfaces to protect the treatment and/or adhesive composition from contamination or moisture. It is within the scope of the invention to provide a treatment composition that is initially separate from a barrier layer in the shape of a treatment device and that is applied onto the barrier layer by the end user. These and other advantages and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. | 20040219 | 20060613 | 20050825 | 91128.0 | 0 | WEHNER, CARY ELLEN | UNIVERSAL TRAY DESIGN HAVING ANATOMICAL FEATURES TO ENHANCE FIT | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,783,662 | ACCEPTED | Copper-faced modules, imprinted copper circuits, and their application to supercomputers | A method for fabricating copper-faced electronic modules is described. These modules are mechanically robust, thermally accessible for cooling purposes, and capable of supporting high power circuits, including operation at 10 GHz and above. An imprinting method is described for patterning the copper layers of the interconnection circuit, including a variation of the imprinting method to create a special assembly layer having wells filled with solder. The flip chip assembly method comprising stud bumps inserted into wells enables unlimited rework of defective chips. The methods can be applied to multi chip modules that may be connected to other electronic systems or subsystems using feeds through the copper substrate, using a new type of module access cable, or by wireless means. The top copper plate can be replaced with a chamber containing circulating cooling fluid for aggressive cooling that may be required for servers and supercomputers. Application of these methods to create a liquid cooled supercomputer is described. | 1. An electronic module comprising: an electrically conductive substrate; conductive feedthroughs in said conductive substrate; a multi-layer interconnection circuit having conductive traces fabricated on said conductive substrate; one or more integrated circuit chips having bumps that attach to selected traces of said interconnection circuits; and, wherein selected of said feedthroughs connect with selected traces of said interconnection circuits. 2. An electronic module comprising: an electrically conductive substrate; a multi-layer interconnection circuit having conductive traces fabricated on said conductive substrate; one or more integrated circuit chips having bumps that attach to selected traces of said interconnection circuits; and, one or more cables having bumps that attach to selected traces of said interconnection circuit. 3. The electronic module of claims 1 or 2 wherein one or more of said integrated circuit chips implement the function of a radio frequency transceiver. 4. The electronic module of claims 1 or 2 wherein said attachment of said bumps includes a well filled with solder interposed between each of said bumps and each of said traces. 5. An electronic system comprising: an electrically conductive substrate; a multi-layer interconnection circuit having conductive traces fabricated on said conductive substrate, selected traces of said interconnection circuits terminating at input/output pads; and, one or more electronic modules attached to said interconnection circuit using bumps that connect with said input/output pads. 6. The electronic module of claims 1-4 and including a top conductive plate bonded to the backsides of said integrated circuit chips. 7. The electronic system of claim 5 and including a top conductive plate bonded to the backsides of said modules. 8. The module or system of claims 1-7 wherein said conductive substrate is copper or dispersion strengthened copper. 9. The module of claim 6 or system of claim 7 wherein said top conductive plate is copper or dispersion strengthened copper. 10. The module of claim 1 wherein said multi-layer circuit comprises alternating layers of a patterned conductive material and a dielectric material. 11. The module of claim 10 wherein said dielectric is a thermoplastic material. 12. The module of claim 11 wherein said thermo plastic material is a liquid crystal polymer. 13. The module of claims 1-2 wherein said traces are formed from electroplated copper. 14. The module or system of claim 9 wherein said conductive top plate is replaced with a cooling chamber through which a cooling fluid may circulate. 15. The module or system of claims 1-5 wherein said bumps are gold stud bumps. 16. The module or system of claim 15 wherein said stud bumps are inserted into corresponding wells filled with solder provided in a special assembly layer on top of said interconnection circuits. 17. An electronic system fabricated on a blade comprising: a conductive blade substrate; a multi-layer interconnection circuit fabricated on said blade substrate, with selected traces terminating in input/output pads; a special assembly layer formed on top of said interconnection circuit that provides a well filled with solder at each of said input/output pads; and, a plurality of integrated circuit chips that are flip chip mounted using bumps that are inserted into said wells. 18. The blade system of claim 17 wherein said circuit chips are provided in groupings that include logic, memory, and communication functions. 19. The blade system of claim 18 wherein a plurality of said groups is arrayed to form a supergroup, and said supergroup may include an additional set of chips providing support functions for said supergroup. 20. The blade system of claim 19 including multiple supergroups, plus special chips for communicating between blades. 21. The blade system of claim 17 wherein said integrated circuit chips have their backsides thermally coupled to a conducting plate. 22. The blade system of claim 21 wherein said conducting plate is replaced with a flat chamber fabricated from thermally conducting material wherein said chamber is co-extensive with said blades and is filled with a cooling fluid that circulates within said chamber. 23. The blade system of claim 17 wherein said conductive substrate is copper or dispersion-strengthened copper. 24. The blade system of claim 17 wherein said imprintable dielectric material is a thermo plastic material. 25. The blade system of claim 17 wherein said thermo plastic material is a liquid crystal polymer. 26. The blade system of claim 17 wherein said traces are formed from electroplated copper. 27. The blade system of claim 17 wherein said bumps are gold stud bumps. 28. A method for fabricating a conductive plate with isolated feedthroughs comprising the steps of: providing a suitable base material for said conductive plate such as copper, or an alloy of copper, or a dispersion hardened form of copper; drilling said plate with holes on a suitable grid; filling each of said holes with a plug of dielectric material and polishing to planarize; drilling said dielectric plugs to create apertures concentric with said holes; laminating a sheet of dielectric material so as to cover said apertures on one side of said conductive plate; coating the side and bottom walls of said apertures with an adhesion layer such as titanium, followed by a seed layer of copper; electroplating copper to fill said apertures and form feedthroughs; polishing to planarize said electroplated copper and provide electrical isolation between said feedthroughs; patterning a mask layer of material such as aluminum on said laminated dielectric material, with apertures matching said apertures in said dielectric plugs; dry etching through said apertures to expose said electroplated copper; depositing an adhesion layer of a material such as titanium and a seed layer of copper or gold onto said exposed electroplated copper; and, electroplating said seed layer to produce a plated contact under each of said feedthroughs. 29. A dual damascene method for patterning a pair of layers including a conductive layer and a dielectric layer of an interconnection circuit comprising the steps of: providing a planarized surface with exposed contact pads; providing a layer of thermoplastic dielectric material over said planarized surface; aligning a toolfoil and imprinting a dual level pattern, said dual levels including a lesser depth for trenches, and a greater depth for vias, with said vias aligned with said contacts pads; removing any remaining web of dielectric material to expose said contact pads; coating said imprinted pattern with an adhesion layer of a material such as titanium followed by a seed layer of copper; electroplating said seed layer to fill said vias and provide a suitable trench thickness of several microns; and, polishing said electroplated material to provide a planarized surface and to provide electrical isolation between said trenches. 30. A method for imprinting a special assembly layer that includes a conductive well at each input/output pad of an interconnection circuit comprising the steps of:. providing exposed input/output pads at a polished and planarized surface; providing a layer of thermoplastic material over said interconnection circuit; aligning an embossing tool to alignment features of said interconnection circuit; pressing said embossing tool into said imprintable dielectric to form a well including at least a portion of said well that is formed in close proximity to corresponding said input/output pad; cooling to room temperature if necessary and separating said embossing tool from said interconnection circuit; removing by etching or other means a remaining web of said imprintable material if any, to expose said input output pads; depositing a diffusion barrier material such as nickel to a thickness of approximately 1.5 microns; polishing until a planarized surface is achieved and said wells are electrically isolated from one another; and, filling said wells with solder paste. 31. A method for reworking defective die on a blade substrate comprising the steps of: providing wells filled with solder at input/output pads of said blade substrate; providing integrated circuits in bare die form; providing conductive bumps at bonding sites of said integrated circuits, said bonding sites corresponding with said input/output pads; assembling said integrated circuits onto said blade substrate by inserting said conductive bumps in said wells filled with solder, melting said solder as required; providing means to test said blade substrate and identify any defective integrated circuits; heating said blade substrate to a temperature below the solder melting point using a hot plate; providing additional heat to said defective integrated circuit using hot inert gas applied to the backside of said bare die; removing said defective integrated circuit by withdrawing said conductive bumps from said wells filled with solder; cleaning the surface of said blade substrate around the site of said defective die as required; providing additional solder in said wells as required; and, inserting a good integrated circuit to replace said defective integrated circuit, providing heating to melt said solder and cooling as required. 32. A supercomputer arranged in the approximate shape of a cube comprising: a parallel array of planar shaped cooling chambers; blade components, each having a conductive substrate, wherein said substrate is thermally coupled to at least one of said cooling chambers and said blade components each include more than 100 flip chip mounted integrated circuit chips assembled onto circuits fabricated on said substrate. 33. The supercomputer of claim 32 wherein said blades are interconnected using blade access cables attached to blade access ports provided on each of said blades. 34. The supercomputer of claim 33 wherein each of said blade access ports includes an array of terminals wherein each of said terminals comprises a well filled with solder, and said wells are spaced apart with a pitch of 200 microns or less. 35. A blade access cable comprising: a rigid carrier for use during fabrication; a release layer employing ultra violet release materials; one or more signal layers; two or more ground or power planes; and, a stud bump at each input/output pad. 36. The blade access cable of claim 35 wherein said stud bumps are provided at a pitch of less than 200 microns. | RELATED APPLICATIONS This application claims priority to provisional Application Ser. No. 60/496,948 filed Aug. 20, 2003. BRIEF DESCRIPTION OF THE INVENTION This invention relates to apparatus and method for building microelectronic modules having one or two conductive faceplates, imprinting methods, and their application to blade servers and supercomputers. BACKGROUND OF THE INVENTION Conventional printed circuit boards are constructed using copper signal planes laminated between glass-epoxy layers. Copper planes (foils) are also used for ground and for power supply voltages. For conventional epoxy laminate boards, trace and space dimensions are typically 100 microns each for a trace pitch of 200 microns, and hole diameters for plated through holes are typically 340 microns or more. More advanced boards are available from companies such as Unitive, Inc. of Research Triangle Park, N.C., USA. Unitive's boards employ BCB, a spin-on resin available from Dow Chemical Company, rather than glass-epoxy. For a copper trace thickness of 2-3 microns, these boards achieve trace widths as small as 12 microns and trace spacing as small as 13 microns; traces on different levels are connected using vias with a diameter of 35 microns and a pitch of 45-55 microns. At 10 GHz the dielectric constant of BCB is 2.65 and its dissipation factor is 0.002. Its coefficient of thermal expansion (CTE) is 52 ppm/° C., and its moisture uptake is 0.14% by weight (as reported by Dow Chemical). Moisture uptake is critical because small amounts of absorbed water can substantially raise the effective dielectric constant, and a higher dielectric constant may effectively prohibit high frequency operation. The CTE of copper is 17 ppm/° C.; various researchers list the CTE of silicon as 2.6-4.2 ppm/° C. The coefficients of thermal expansion are important because the manufacturing process typically requires thermal cycles, and mismatches in CTE between materials in a stacked configuration result in mechanical stresses that can damage the board, or components attached to it. Additional thermal cycling is typically present during operation of the board, but usually this variation is less than during manufacturing and assembly. In recent years, imprinting methods have been developed for several products. An example is the compact disc (CD) that has been manufactured by pressing a master tool into a plastic material, leaving an imprint of the desired pattern. A feature size of one micron and a fabrication cost less than a dollar per square foot have been reported. For both integrated circuit manufacture and printed circuit board manufacture, the imprinting method has potential to be an inexpensive patterning method compared with current photolithographic patterning methods. Photolithography has been the mainstay of integrated circuit patterning for many decades; it generally requires highly sophisticated tools for projecting a beam of light through a mask onto photosensitive materials. A fabrication facility to process silicon wafers by this method typically costs more than US$1 B today. By contrast, imprinting requires unsophisticated tools, yet it can produce fine features, smaller than 100 nanometers in some applications. The tools required for imprinting generally include a laminating press with provisions for aligning the layers, and for heating the thermoplastic material to be patterned. Cold embossing has also been developed using glass tools with embossed features etched therein, and UV curable dielectrics. Electroplating is typically used to build up the copper layers, and chemical/mechanical polishing (CMP) is preferably used for planarizing each layer after plating. Imprinting and CMP methods can be combined to implement a dual damascene process using copper as the conductor material. Dual damascene processes are known in the art; “dual” refers to the fact that two depths of copper are implemented: trenches used for creating traces have a lesser depth than cylindrical holes for vias. The combination of tools for imprinting, plating and CMP may cost less than 1% of the cost of equivalent photolithographic tools. Other conductors may be used instead of copper, but copper offers a compelling combination of good electrical and thermal conductivity, adequate mechanical properties (especially in the form of dispersion strengthened copper, to be further discussed), and an infrastructure of existing tools and processes for drilling, electroplating, etching, and polishing at reasonable cost. Liquid crystal display (LCD) panel fabrication plants are now being built for glass panels measuring 1870×2200 mm. The thickness of these glass panels is 0.7 mm, similar to the preferred thickness of 0.6 mm for copper substrates of the current invention. This means that an infrastructure of semiconductor processing equipment, particularly including thin film coating and etching equipment could be adapted to handle copper substrates in panel sizes up to around 2 meters square. This may be useful for coating thin film adhesion layers and seed layers on large panels of the current invention, and for plasma etching dielectric materials, as will be further described. The photolithographic patterning capability for large panels, generally employing step and repeat exposure systems (“steppers”), may also be used for fabricating the embossing tools described herein. The preferred method of imprinting discussed herein uses an embossing tool in the form of a flexible foil, hereinafter called a “toolfoil”. It is also possible to use rigid embossing tools, particularly if release agents are applied to the tool to aid in separation; also if the impressions are shallow they require a relatively small force for release. A release agent comprised of low surface energy material such as teflon is also preferably provided on the toolfoils discussed herein. One method of making a toolfoil is to electroplate nickel in an additive process to create a master or “father” foil. The sidewalls of the plated features preferably have an angle of about 5° to the vertical. This release angle is useful so that negatives of fathers can be made to produce “mothers”, and negatives of mothers are made to produce “sons”, which are the equivalent of photo-tool working plates. Suitable toolfoils can be obtained from Tecan Components Ltd., Dorset, England. If the toolfoil is used to implement a dual damascene process, then two nickel thicknesses are required and two photo-tools (glass masks) will be used in the fabrication of the master. An alternative embodiment of the imprinting method may be used for large patterns that require a step and repeat methodology. Molecular Imprints of Austin, Tex., USA, has developed a step and flash imprint lithography process called S-Fil. In this process, a substrate is coated with an organic planarization layer. Then a low viscosity photo-polymerizable imprint solution is dispensed on the surface. A surface treated transparent template bearing patterned relief structures is aligned over the coated substrate. The template is lowered into contact with the substrate, thereby displacing the solution, filling the imprint field, and trapping the photo-polymerizable imprint solution in the template relief. Irradiation with UV light through the backside of the template cures the solution. The template is then separated from the substrate leaving a relief image on the surface that is a replica of the template pattern. A short halogen etch is used to clear any remaining thin webs of undisplaced material. A subsequent reactive ion etch into the planarization layer may be used to amplify the aspect ratio of the relief image. Liquid crystal polymer (LCP) is a new dielectric material that has recently become available for imprinting applications in the printed circuit board arena. An example of this material is R/Flex 3800 available from Rogers Corp., Circuit Materials Division, Chandler Arizona. It is available with a CTE matched to copper at 17 ppm/° C. Melting points of 280° C. and 315° C. are available, with thickness varying from 25 microns to 100 microns. From 1-10 GHz the dielectric constant is 2.9 and the dissipation factor is 0.002. The moisture uptake is 0.04% by weight (compared with 0.14% for BCB), resulting in good stability for high frequency applications. Dispersion strengthening is a method for improving the strength properties of copper, without seriously affecting its electrical and thermal conductivity. Cold rolled sheets of dispersion strengthened copper (DSC) known as Glidcop are available from SCM Metal Products, Inc., North Carolina. For use as a substrate for a printed circuit of the current invention, this material is available in thickness ranging from 125-625 microns. By incorporating minute amounts of aluminum oxide to pin the grain boundaries of the copper, the yield strength of DSC is typically improved by about 10 times, while the thermal and electrical properties are degraded by less than 1%. Electroplating methods are well known in the art. Current processes support fabrication of via structures with aspect ratios (depth:diameter) as great as 10. Using layered plating solutions and sophisticated power supplies including reverse pulse biasing, void-free plated structures are achievable. CMP is also well known in the art. A substrate to be polished is held in a polishing chuck so that typically one third of its edge dimension extends below the chuck. A polishing slurry is provided between the exposed surface and a rotating wheel having a finely textured surface; the substrate may simultaneously rotate and orbit in a planetary motion with respect to the wheel. The desired result is a polished planar surface with clearly defined copper features embedded in the dielectric resin. Modem computer circuits such as multi-chip modules for computer server applications typically operate at GHz frequencies and with large power supply currents at low operating voltages: 200 amps at 1.0V is a typical requirement. Cooling of the module is a critical issue, and building such circuits on a copper substrate can help address the cooling requirements. In addition, a “copper sandwich” will be described having integral copper plates at both the top and bottom of the assembly for improved ruggedness and better thermal access to the heat-producing chips. Flip chip assembly is generally recognized as the most advanced assembly method in terms of system density and performance. It enables bare integrated circuit (IC) chips to be assembled, in preference to packaged parts. The chips can have area arrays of input/output (1/O) bonding pads, rather than just at the chip periphery. Inductance of these chip-to-board connections is substantially lower than that of wire bonds, and power pins can be located close to the circuit blocks that need the power. Advanced flip chip assembly methods have recently been reported. One such method is to provide gold stud bumps on the IC chips, and corresponding wells filled with solder on the board. This structure supports pad pitches of 100 microns or less and also routine replacement of defective die using a rework process. There have been two major impediments to the integration of large systems that are exclusively or primarily assembled using flip chip assembly methods: the inability to effectively test such a system (particularly a functional test at full system speed), and the inability to rework defective chips in the assembly. For these reasons, many flip chip assemblies have been limited to 10 IC chips or fewer, because the cost of scrapping defective assemblies becomes prohibitive with a greater number of chips. Solutions to these problems have been recently proposed. Firstly, a special-purpose test chip or chips may be provided on the board under test; working together with a test support computer this chip can provide the means to functionally test the module at full system speed. The test chip preferably includes high speed sampling circuits and comparators that are under control of the support computer. The support computer performs low speed testing chores such as boundary scan and loading of test files, and also hosts diagnostic software for aiding a test operator in determining which chips need to be replaced, if any. Secondly, the proposed variation of flip chip assembly allows effective rework of defective chips. In summary, the rework method is as follows. The board is placed on a hot plate and the temperature is raised to a level just below the melting point of the solder in the wells (the preferred melting point of the preferred In:Ag solder is 143° C.). Then a rework wand emitting hot inert gas is directed at the backside of the defective chip; the solder in the wells melts for this chip, but not for neighboring chips that are not defective. Focused infra red systems have also been deployed for heating the area local to a single chip without melting the solder of surrounding chips. After the solder of the defective chip is molten, the stud bumps are withdrawn from the wells, the surface is inspected and cleaned as necessary, the wells are touched up with additional solder paste as required, and a replacement part is picked, flipped, aligned, and inserted. After re-flowing the solder for the replacement part and validating the assembly with another module test, the rework cycle is complete. There is preferably no epoxy under layer beneath the defective chip (whose removal would be labor intensive, difficult, and potentially damaging to the board). Also, there are no delicate traces around or near the I/O pads that can be damaged during the rework process; the receiving terminal becomes the solder paste in the well rather than the pad. Finally, the materials used easily tolerate the rework temperatures. These factors result in a rework procedure that may be repeated as many times as necessary, enabling the integration of systems comprising hundreds or thousands of IC chips, assembled onto a single monolithic high performance substrate (or blade). This high level of integration in turn enables supercomputer architectures of the current invention. The purpose of the epoxy under layer between chip and board is to prevent mechanical failure such as cracking that can arise from stresses accompanying temperature excursions that occur during manufacturing or operation. Part of the justification for eliminating this under layer in the proposed flip chip mounting structure is that the preferred arrangement of gold stud bumps inserted into wells filled with solder is mechanically stronger (shear forces can not easily detach a stud bump from its pad or a well from its pad). Because the stud bumps are formed from gold, and because gold is one of the most ductile materials, and because the proposed stud bumps have a pointed shape, the proposed structure is also more mechanically compliant than previous structures such as solder balls re-flowed onto matching lands. In addition, the low melting point of the proposed indium based solder (143° C.) results in lower thermal strains than would occur with commonly used solders that melt at higher temperatures (63:37 Sn:Pb solder melts at 183° C.). Even with this improved flip chip attachment it may be necessary to limit the maximum chip size in the proposed assembly structures, to limit the stress imposed. For interconnecting modules, module access cables have been proposed that use a similar arrangement of stud bumps and wells as described for attaching the IC chips. These module access cables can support pin pitches of 100 microns or less, and should be re-workable using the same method as outlined for reworking the IC chips. SUMMARY OF THE INVENTION The current invention is intended to address the need for microelectronic assemblies that support operating frequencies of the order of 10 GHz (data rates of the order of 10 Gbps), and power supply currents of several hundred amps. An alternative application is to make lower performance electronic assemblies (sub 1 GHz) less expensively than using current printed circuit board and assembly methods. The preferred embodiment has a base copper layer for mechanical support. A method is described for fabricating feedthroughs in the copper substrate for signals and power. By alternately fabricating layers of dielectric resin and copper conductors, a printed circuit with multiple power and signal planes is built up. Imprinting is used to pattern the layers, preferably using nickel toolfoils. A special assembly layer is preferably fabricated on top of the interconnection circuit wherein a well filled with solder paste is provided at each I/O pad of the board. IC chips are provided with a gold stud bump at each of their I/O pads, and the chips are assembled onto the board by inserting the stud bumps into the wells, then melting the solder to form mechanical and electrical connections. In the preferred embodiment, no epoxy under layer is used between the IC chips and the board. After all the chips are assembled, tested, and reworked as required, a top copper plate may be attached to the backsides of the assembled IC chips, to make a robust mechanical, electrical and thermal package at the module level. An alternate embodiment supports fabrication of modules such as multi-chip modules (MCMs) or system in package (SIP) devices that are integrated onto a motherboard. The motherboard may be a conventional board employing glass-epoxy laminate for example, or a large interconnection circuit fabricated on a copper substrate using methods described herein. For either case, the copper substrate of the attached module is preferably provided with feeds for power and signals that pass through it and connect to the motherboard, typically on a 1 mm grid. In the preferred embodiment, imprinting is used to pattern thermo-plastic dielectric layers, and copper conductors are employed. LCP is the preferred dielectric material and DSC is the preferred form of copper for the base layer. After CMP has been used to polish and planarize the surface of a preceding layer, the following sequence summarizes the steps to form the next pair of interleaved dielectric and conducting layers: a) place a sheet of LCP on top of the polished planar assembly b) mount a toolfoil on a rigid carrier, align and position on top of the LCP sheet c) apply heat to soften the LCP d) apply pressure to imprint the LCP e) cool to room temperature and separate toolfoil from its carrier f) peel the toil foil away from the assembly g) dry etch or sputter etch any remaining web of dielectric material, to expose the copper patterns underneath h) sputter deposit an adhesion layer such as Ti plus a seed layer of Cu i) plate Cu to the desired thickness, typically 3-5 microns in the trenches, some of which is removed in the following step j) CMP to delineate the Cu patterns and planarize the surface A variation of this imprinting procedure will be described for forming the special assembly layer having wells at each of the I/O pads of the interconnection circuit. “Imprinting” and “embossing” are used interchangeably in this application. These techniques are employed to create copper-faced modules configured as blade servers, plus their integration into liquid-cooled supercomputers of the current invention. BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the invention are described below with reference to the following accompanying drawings. FIG. 1 is a perspective view of a module built on a conductive substrate that uses a module access cable to communicate with other electronic systems. FIG. 2 is a perspective view of a module built on a conductive substrate that uses feeds through the copper plate (not shown) to communicate with a motherboard. FIG. 3 is a plan view of the underside of a conductive substrate having feedthroughs arranged in a two-dimensional grid. FIG. 4 is a perspective view of a module built on a conductive substrate that uses a wireless link to communicate with other electronic systems. FIG. 5 is a plan view of a system substrate having multiple modules attached, that connects to other electronic systems using a module access cable. FIG. 6 is a perspective view of a module having two conductive faces that connects to other electronic systems using a module access cable. FIG. 7 is a perspective view of a module having two conductive faces that connects to other electronic systems using feeds (not shown) through the bottom conductive face (substrate). FIG. 8 is a perspective view of a module having two conductive faces that communicates with other electronic systems by wireless means. FIG. 9 is a plan view of a system substrate having two conductive faces, with multiple modules attached to the bottom face (substrate), that connects to other electronic systems using a module access cable. FIG. 10 is a schematic side view of a stack of layers to be laminated for drilling. FIG. 11 is a cross-sectional view of a fragment of a conducting substrate having feedthrough holes drilled therein. FIGS. 12(a)-(g) includes fragmentary cross-sectional views that illustrate the process steps required for fabrication of feedthroughs in a conducting substrate. FIG. 13A is a plan view of a fragment of an embossing tool in the form of a toolfoil showing a trench and an associated via. FIG. 13B is a cross-section of the trench and via of the toolfoil shown in FIG. 13A. FIG. 13C is a schematic cross-sectional view of an imprint corresponding to the toolfoil of FIGS. 13A and 13B. FIG. 14 is a schematic cross-sectional view of an aligner/laminating press for making imprinted patterns of the current invention. FIGS. 15(a)-(d) illustrates in cross-section the process steps to fabricate a pair of interconnection layers including a conductive layer and a dielectric layer. FIG. 16(a)-(e) illustrates in cross-section the process steps to fabricate a special assembly layer including wells filled with solder. FIG. 17 is a cross-section of a fragment of a module assembly including a conductive substrate with feedthroughs, interconnection circuits, and a flip-chip mounted die. FIG. 18 is a flow chart that summarizes the process steps for imprinting a pair of layers of an interconnection circuit. FIG. 19 is a flow chart that summarizes the process steps for imprinting a special assembly layer, including wells for flip chip assembly. FIG. 20 is a schematic cross-sectional side view of a supercomputer of the current invention. FIG. 21 is a schematic top view of the supercomputer of FIG. 20. FIG. 22 shows a group of integrated circuit chips including processing, memory, and communication capabilities. FIG. 23 shows a supergroup of integrated circuit chips including multiple groups defined as in FIG. 22 plus other special purpose chips. FIG. 24 shows a blade layout including multiple super groups of integrated circuit chips, plus blade access ports. FIG. 25A shows a fragment of a blade computer with a blade access port. FIG. 25B shows cross-sectional details corresponding to section BB of FIG. 25A. FIG. 26 shows a blade access cable attached to a rigid carrier using a release layer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an electronic module 10 having a conductive substrate 11. (base layer), and multiple integrated circuit chips (IC chips) such as 12 flip chip mounted thereon. Module 10 receives power and communicates with other electronic systems via module access cable 13, utilizing module access port 14, as will be further described. The attachment of IC chips 12 and access cable 13 preferably employ a new version of flip chip assembly wherein each input/output pad of each chip and each cable preferably has a stud bump attached, and each stud bump mates with a well filled with solder formed on top of the interconnection circuit (not shown) fabricated on substrate 11. Detailed manufacturing steps for fabricating these circuits will be described. IC chip 15 may be a test chip, as will be further described. The material of conductive substrate 11 is preferably copper or a dispersion-strengthened copper (DSC). FIG. 1 is an example of a module with a single conductive face. FIG. 2 shows another module 20 with a single conductive face 21 (substrate), except that this substrate has feeds for signals and power (feedthroughs) running through it (not shown), as will be further described. All of the conductive faces in modules and systems described in this application, including substrates and top plates (to be described), are preferably manufactured from copper or DSC. Multiple IC chips such as 12 of FIG. 1 are flip chip mounted as shown. FIG. 3 shows the backside of substrate 21 including a two-dimensional array of input/output terminals such as 22, preferably arranged on a 1 mm grid. The fabrication of the feedthroughs and terminals will be further described. FIG. 4 shows another module 30 having a single conductive face 11 and multiple IC chips such as 12 flip chip mounted thereon as in FIG. 1, and includes a wireless transceiver chip 32 (or group of chips), that preferably communicates via a two-way radio link 33 with other electronic systems. Power to module 30 may be provided using energy storage devices such as batteries or fuel cells (not shown), or via a cable like 13 of FIG. 1, or via feedthroughs to a motherboard as in module 20 of FIG. 2. FIG. 5 shows an electronic system 40 including a system substrate 41 (base plate) and multiple modules such as 20 of FIG. 2 mounted thereon. Additional IC chips such as 43 may be included on substrate 41. Chips 43 may be used for testing, for power conversion, for maintenance and administration, for implementing interface protocols and driving communication interfaces, or for diagnostic purposes, as examples. System 40 interfaces to other electronic systems using system access cable 44 connected to system access port 45. However, system 40 may additionally or alternatively communicate with other systems using feeds through substrate 41 to another electronic assembly, or by wireless means. FIG. 6 shows electronic module 50 having two conductive faces: substrate 11 as in FIG. 1 and top plate 52. Sandwiched between the two faces are flip chip mounted components such as 53 shown in dotted outline for illustration purposes. Module 50 may communicate with other electronic systems via a module access cable like 13 of FIG. 1. After flip chip assembly (direct attachment) of all of the components onto substrate 11, a grinding or lapping step may be employed to make the components of uniform thickness, and provide a planar surface for attachment of top plate 52. Top plate 52 may be bonded or thermally coupled to the backsides of the IC chips using conductive epoxy or eutectic bonding materials or thermal grease, as is known in the art. FIG. 7 shows electronic module 60 having two conductive faces: a substrate 21 as in FIG. 2 and a top plate 62. The backside of substrate 21 includes an array of feedthroughs for signals and power, as depicted in FIG. 3. FIG. 8 shows module 70 having two conductive faces: substrate 11 as in FIG. 1 and top plate 72. However in contrast with top plate 62 of FIG. 7, top plate 72 has an opening 73 for radio waves to interact with radio transceiver chip 74, to enable a radio link 33 as in FIG. 4. FIG. 9 shows electronic system 80 that is similar to system 40 except that a top plate covers the modules such as 20 of FIG. 2 and IC chips such as 43 of FIG. 5, shown in dotted outline. System 80 communicates with other systems via a system access cable like 44 of FIG. 5, but other communication methods may be additionally or alternatively employed. FIG. 10 shows a stack of metal layers 90 that can be assembled with layers of wax 91 between each of the metal sheets. This stack is used to drill feedthrough holes in the copper or DSC substrates that include feeds for signals and power. A suitable wax is Ocon-195, and a preferred wax thickness between the metal layers is around 0.008 inches or 200 microns. For the preferred substrate thickness of 600 microns, a suitable drill diameter is 0.0295 inches or 750 microns. A 0.040 inch thick layer of aluminum is preferably provided as a top layer 92 and as a bottom layer 93 of the stack; this provides more cleanly drilled holes at the inner layers, with some tearing permitted at the entry and exit, confined to the aluminum layers. In addition, the interposed wax layers 91 allow the drill to clear between each of the inner layers. A center drill is used to “spot drill” each location with a small diameter hole that is accurately placed, e.g., using a “0” center drill that will create a “dimple” with 0.030 inch diameter. Typically a drilling stack will include 8 layers of 600 micron thick substrate material 94. The preferred drilling machine is a vertical milling center such as the Bridgeport VMC 760. Using the same machine setup, it may also be desirable to mill the outline of the stack to a standard wafer size; the standard shape provides compatibility with mask aligners that may be employed for the lamination step, to be further described. FIG. 11 shows a fragment 95 of substrate 21 as in FIG. 2 in which holes 96 have been drilled with a preferred pitch, P, 97 of 1 mm or 1000 microns, and a preferred diameter, D, 98 of 0.0295 inches or 750 microns. FIG. 12 summarizes a preferred process sequence for fabricating feedthroughs in a copper substrate such as 21 of FIG. 2, starting with a substrate layer that has been drilled as in FIG. 11. FIG. 12(a) shows that the drilled holes 96 have been filled with a dielectric material 100 such as a liquid crystal polymer. Since the available thickness of LCP may be limited to 100 microns, it may be necessary to stack and laminate 7 or 8 sheets to reliably fill drilled holes 96. After lamination, the top and bottom surfaces are preferably polished using CMP to achieve planarization. FIG. 12(b) shows that dielectric material 100 has been concentrically drilled with a preferred drill size of 0.0225 inches or 572 microns. This step may be performed with individual substrates, or with a stack of substrates that has been pre-aligned and bonded with wax. For alignment purposes, 4 separate alignment holes are provided outside the two dimensional array of feedthrough holes, one in each quadrant (not shown). FIG. 12(c) shows that a layer of LCP 102 has been laminated onto the bottom of the drilled substrate, and a coating has been deposited that coats the bottom 103 and the walls 104 of drilled aperture 101. Coating 104 includes an adhesion layer such as titanium to a preferred thickness of 300-400 Angstroms or 0.03-0.04 microns, plus a seed layer of copper to a preferred thickness of 500-800 Angstroms or 0.05-0.08 microns. FIG. 12(d) shows electroplated copper 105 filling the holes. Advanced plating methods including layered chemicals in the plating bath and pulse-reversing power supplies to effect plating from the bottom up are preferred. An uneven surface 106 results, and this is polished using CMP to achieve the planarized top surface 107 shown in FIG. 12(e). FIG. 12(f) shows that a masking layer 108 has been deposited and patterned to expose laminated dielectric material 102 at the base of each feedthrough, and this layer has been removed by dry etching through the metal mask to expose electroplated copper material 105. A preferred material for masking layer 108 is aluminum. Finally, FIG. 12(g) shows the result of coating the exposed copper with an adhesion layer of titanium plus a seed layer of gold, electroplating gold to form gold contacts 109 on the bottom side of each feedthrough, and etching away masking layer 108. In the preferred embodiment, copper substrate 110 includes copper feedthroughs in a copper substrate that is 0.6 mm thick, having a pitch P, 97, of 1 mm, with a gold contact at the base of each feedthrough. FIG. 13A shows a fragment of a toolfoil 120 including a first raised portion 121 for imprinting a trench pattern, and a second raised portion 122 for imprinting a via. FIG. 13B shows profile 123 of the toolfoil features in cross-section. Trench depth d1, 124, and via depth d2, 125, are shown. Release angle θ, 126, is preferably around 5° so that molded parts can be separated from toolfoil 120. It is also preferable to coat toolfoil 120 with a release material having a low surface energy such as teflon. FIG. 13C shows the imprinted pattern achieved by impressing toolfoil 120 with profile 123 into a plastic material such as a heated liquid crystal polymer 127. Typically, the smaller depth d1, 124 is faithfully transferred, and d3, 128 equals d1. However, the larger depth d2, 125 is typically imperfectly transferred due to the spreading characteristics of the plastic material, and d4, 129<d2. For the preferred geometries of the current invention, d1 equals approximately 4 microns, d2 equals approximately 20 microns, d3 equals approximately 4 microns, and d4 equals approximately 16 microns. After plating and polishing, these geometries result in a trace thickness of approximately 2 microns, and a total via depth of approximately 18 microns, with approximately 5 microns of web material 130 removed by dry etching to expose the underlying contact metal (not shown), that is intended to connect with the via metal. FIG. 14 is a schematic of a laminating press/alignment fixture 134 suitable for making imprints of the current invention. This schematic represents a modified version of a commercial mask aligner, the MA600 available from Suss Microtec. Normally this tool operates with a glass mask (photo tool) held in a mask holder, and a semiconductor wafer held in a wafer chuck. It provides alignment optics for aligning wafer to mask, controlled UV radiation from above for exposing photo resist and other UV sensitive materials, and controlled pressure between mask and wafer up to about 15 pounds per square inch. The modification relates to the addition of infrared heating 143 directed toward the wafer chuck from below, as will be further explained. For the current application, the mask is replaced by an assembly including a glass plate 135 and toolfoil 120 of FIG. 13B bonded to plate 135 using a UV release layer 136. The glass plate is captured in position by mask holder 137. From the bottom side, quartz chuck 138 holds copper substrate 139 (preferably machined in the form of a semiconductor wafer) which may have some interconnection circuit layers 140 already formed on it. A sheet of thermoplastic dielectric material 141 is positioned over interconnection circuits 140, but it is trimmed so as not to cover alignment holes in copper substrate 139. An operator employs alignment optics 142 to align copper substrate 139 with toolfoil 120. Toolfoil 120 has alignment features in the form of apertures that are sized slightly larger than the alignment holes drilled in copper substrate 139. The alignment operator achieves alignment by centering the concentric circles of the two sets of alignment features. Note that “copper substrate”, “conductive substrate”, and “DSC substrate” are interchangeable in this application. After substrate 139 and toolfoil 120 are properly aligned, heat is applied to copper substrate 139 using infrared radiating lamps positioned in a space underneath quartz chuck 138. The wavelength of IR radiation 143 is carefully selected so that the radiation will not be absorbed by quartz chuck 138, but will be absorbed by copper substrate 139. As substrate 139 heats up, it will emit radiation that can be detected by a sensor below quartz chuck 138 for tracking its temperature during heating and cooling cycles (at temperatures above a certain minimum, depending on the wavelength of the IR radiation). A wavelength of 2.5 microns is suitable in the preferred embodiment. Heating of substrate 139 is monitored until a desired softening point or melting point of the dielectric material is reached. In the preferred embodiment, 280° C. is the melting point of the LCP dielectric. The preferred embossing temperature is around 200° C. so that the LCP remains contained in the embossed layers during each imprint cycle. The required pressure for imprinting will vary with the particular patterns imprinted, the materials used, and the embossing temperature. A process of trial and error is required to determine the optimal pressure for a particular setup; the goal is to provide clean trenches and vias and leave only a thin web of dielectric material to be removed. The thickness of the web for the preferred embodiment is approximately 5 microns (using 25 micron LCP sheets). After imprinting, IR radiation 143 is turned off and the parts are allowed to cool, while force 144 is applied. Then UV exposure 145 is turned on to radiate the UV release material, to effect separation between toolfoil 120 and glass plate 135 as the pressure is released. Substrate 139 with the new imprint pattern is removed from fixture 134, and toolfoil 120 is peeled away. FIG. 15(a) shows a fragment of a pre-existing interconnection circuit 150 that has been planarized and has an exposed contact region 151 on a dielectric material 152. Following an imprinting sequence as described in reference to FIG. 14, trenches 153 and vias 154 are imprinted as shown in FIG. 15(b), with a thin web of dielectric material 155 remaining. Web 155 is removed by dry etching or sputter etching, and the profile is as shown in FIG. 15(c). An adhesion layer is coated onto the surface, such as 300-400 Angstroms of titanium, followed by a seed layer of copper having a preferred thickness of 500-800 Angstroms. The seed copper is then electroplated from the bottom up, and the top surface is polished to planarize it and to isolate the trench conductors 156 shown in FIG. 15(d). The bottom of via 157 is in intimate contact with contact region 151 for a low resistance connection. Because copper and LCP both have CTEs of 17 ppm/° C., there should be minimal distortion or warping of the substrate during manufacture of these layer pairs, particularly if copper is also used as the base substrate layer. FIG. 16 illustrates a modified imprinting sequence for forming a special assembly layer including wells filled with solder. FIG. 16(a) shows a pre-existing interconnection circuit 160 that has been polished and planarized, exposing polished trace 161. FIG. 16(b) shows an imprint of a well feature 162, positioned above a conducting trace, fabricated using the procedure described in reference to FIG. 14. Dielectric 163 is preferably BCB that has been applied using a spin-on method. FIG. 16(c) shows that the remaining web of dielectric material 164 has been removed, and the top surface has been coated with an adhesion layer of titanium plus nickel to a thickness of approximately 50 micro inches or 1.3 microns. Nickel coating 165 provides a diffusion barrier between the copper traces of the underlying structure and the solder materials to be provided in the well. After polishing and planarization the nickel coating is removed except for coating in the well 166, as shown in FIG. 16(d). FIG. 16(e) shows that well 166 has been filled with solder paste 167 to form a well filled with solder 169, and a gold stud bump 168 has been inserted. After a reflow cycle to melt solder paste 167, a permanent mechanical and electrical connection is achieved. The preferred solder paste 167 is 3% silver and 97% indium with a melting point of 143° C. Preferred dimensions for a well include a diameter of 55 microns and a depth of 15 microns. By using imprinting to pattern them, economic fabrication is achievable for creating wells at a pitch of 100 microns or less. For logic elements requiring a large number of input/output connections, many thousands or even millions of wells can be filled with paste using one pass of a squeegee. Including the cost of the imprinted layer and a material cost of approximately 0.00008 cents per well for Indalloy 290 at $3.48/gm leads to a manufacturing cost of less than 0.02 cents per well. Coupled with an estimated cost of 0.03 cents per gold stud bump, high density flip chip bonds may be achieved at 0.05 cents per connection. In addition, these bump/well connections are anticipated to be re-workable using simple and effective procedures, without risk of damaging the board to which the components are flip chip mounted. FIG. 17 shows a scaled fragment of a flip chip assembly 170 using the method of the current invention. Copper substrate 110 of FIG. 12 has feeds for signals and power as previously described, including substrate 94 of FIG. 10, dielectric material 100, and electroplated copper 105. Interconnection circuit 171 includes 4 signal layers 172 and 3 power planes 173, plus a special assembly layer 174 including wells filled with solder 169. Stud bumps 168 of FIG. 16 are attached to I/O pads on IC chips like 15 of FIG. 1 and inserted into wells 169 at a preferred pitch of 100 microns. Because of the good dielectric properties of LCP, and using known methods for creating differential signal pairs having controlled impedance, an assembly represented by FIG. 17 can operate at high frequencies. With copper and LCP both having CTEs of around 17 ppm/° C. and silicon having a CTE of around 3.5 ppm/° C., stress will be induced in assembly 170 as the components cool after the flip chip assembly procedure. The strains arising from these stresses have to be taken up by mechanical compliance of the bump/well structure, plus some compliance of the LCP dielectric. If a copper top plate like 52 of FIG. 6 is employed, everything except the silicon chips will be thermally matched. Since the copper base plate and top plate are typically thicker and stronger than the silicon chips, strain will occur mostly in the silicon chips. However, this strain is acceptable for most IC chips, and a module having matched copper faceplates will not warp significantly during the temperature excursions of typical operating environments. It should be mechanically robust, easily cooled, and electrically quiet (low electromagnetic radiation). FIG. 18 is a summary flow chart of the aforementioned process for creating a pair of interconnection layers, including a conducting layer and a dielectric layer of an interconnection circuit. FIG. 19 is a summary flow chart of the additional process steps required to form a special assembly layer including wells that can be filled with solder. The copper-faced modules described herein can be integrated into servers and supercomputers to provide greater functional density and better cooling than have been available to date. FIG. 20 is a schematic side view of a supercomputer 200 of the current invention, formed in the approximate shape of a cube. Cooling chambers 201 have a planar shape with a coolant fluid entering at an inlet port 202 and exiting at an outlet port 203. Manifolds (not shown) distribute the incoming fluid flows 204 and the outgoing fluid flows 205 through ports such as 202 and 203. A blade component (or “blade system”) 206 is constructed on a conducting substrate 207, and is sandwiched between a pair of cooling chambers 201. Substrate 207 is like an enlarged version of substrate 11 of FIG. 1. IC chips such as 208 are flip chip mounted to blade component 206, preferably using bumps 168 and wells 169 as previously described in reference to FIG. 16. Because the flip chip assembly method provides a high functional density on blade 206, and because cooling chambers 201 can be constructed to have a thin profile, new levels of system density can be achieved. With higher system density, signal paths are shorter and operating speeds are higher. Key factors that enable such large flip chip assemblies include new methods of testing and rework that are described in the background section of this application. FIG. 21 shows a schematic top view of supercomputer 200 of FIG. 20, showing outlet ports 203. Blade access cables 211 are provided for each blade to connect to each of its neighbors, as will be further described. System input/output cables 212 and 213 are also provided. FIG. 22 shows that IC chips may be formed into groups 220, each group preferably containing a computing chip 221, a bus interface chip or other communications chip 222, and one or more memory chips 223. FIG. 23 shows that groups 220 may be integrated into supergroups 230, comprising multiple copies of group 220 plus a single copy of special purpose chips such as may be provided for testing 231, power conversion 232, cross bar switching 233 between pairs of groups or supergroups (for high speed group-to-group communications), and also chips for diagnostics, maintenance and administration 234. Another important function for a special purpose chip may be scheduling of events in preparation for connecting a pair of computing nodes, using a cross bar switch for example. If a failure occurs in a blade system at a commercial business (“in the field”), any required rework will be expensive. Rather than rework any failing elements of such a blade system, it is preferable to provide an administration function that keeps track of defective elements or groups, and automatically switches them out of operation if any defects occur. To detect failures, periodic health checks of all hardware elements may be conducted in the background, using test chips such as 231. The impact of a failed group will be small because it represents a small fraction of the total functionality, and maintenance costs will be minimized. FIG. 24 shows a top view of blade 206 of FIG. 20 including multiple supergroups 230 as described in FIG. 23 arrayed thereon plus an upper blade access port 241 and a lower blade access port 242. Combining the two access ports on each blade with upper and lower blade access cables like 211 of FIG. 21, it can be seen that each blade can be connected to each of its neighbors. Cable driver/receiver circuits may be implemented on transceiver chips such as 243. As previously discussed, a semiconductor manufacturing infrastructure exists for flat panels as large as 2 meters on a side. In principle, large toolfoils could be fabricated for imprinting such a large panel in one step; the photo-imaging of such a large toolfoil area could be accomplished using a stepper exposure system, employing photolithographic exposure systems already in service for LCD manufacture. If this is done, the preferred dielectric material (LCP) can be used and high frequency circuits can be produced in large panels using a single imprint cycle. Alternatively, imprinting of large panels can be achieved using a step and repeat imprinting process like the S-Fil process already described. FIG. 25A shows a blade access cable like 211 of FIG. 21 connecting to upper blade access port 241 of FIG. 24. FIG. 25B shows an expanded cross-sectional view of section BB of FIG. 25A. An interconnection circuit 251 preferably includes multiple signal and power layers plus special assembly layer 174 of FIG. 17. Stud bumps 168 as shown in FIG. 16 connect between input/output pads 252 on cable 211 and corresponding wells filled with solder connecting to traces or nodes 253 of interconnection circuit 251. The pitch P 254 of these bump/well connections is preferably 100 microns. Cable 211 preferably includes a signal layer 255 and two ground layers 256. The arrangement of FIG. 25B supports a connection density of 10,000 connections per square centimeter (at a pad pitch of 100 microns), while also supporting controlled impedances for high frequency operation. For pad pitches as small as 100 microns, as shown in FIG. 25B, dimensional stability during assembly of the parts is essential. Cable 211 includes conductive and dielectric materials that flex; it is a flexible circuit and typically does not exhibit good dimensional stability. Therefore, cable 211 must be supported on a rigid carrier with good dimensional stability until all the connections have been made and tested. Carrier 260 in FIG. 26 provides this capability; in the preferred embodiment it is a glass substrate on which cable 211 is fabricated. Release layer 261 is preferably formed from a UV release material, and release is preferably achieved using intense UV exposure through carrier 260. | <SOH> BACKGROUND OF THE INVENTION <EOH>Conventional printed circuit boards are constructed using copper signal planes laminated between glass-epoxy layers. Copper planes (foils) are also used for ground and for power supply voltages. For conventional epoxy laminate boards, trace and space dimensions are typically 100 microns each for a trace pitch of 200 microns, and hole diameters for plated through holes are typically 340 microns or more. More advanced boards are available from companies such as Unitive, Inc. of Research Triangle Park, N.C., USA. Unitive's boards employ BCB, a spin-on resin available from Dow Chemical Company, rather than glass-epoxy. For a copper trace thickness of 2-3 microns, these boards achieve trace widths as small as 12 microns and trace spacing as small as 13 microns; traces on different levels are connected using vias with a diameter of 35 microns and a pitch of 45-55 microns. At 10 GHz the dielectric constant of BCB is 2.65 and its dissipation factor is 0.002. Its coefficient of thermal expansion (CTE) is 52 ppm/° C., and its moisture uptake is 0.14% by weight (as reported by Dow Chemical). Moisture uptake is critical because small amounts of absorbed water can substantially raise the effective dielectric constant, and a higher dielectric constant may effectively prohibit high frequency operation. The CTE of copper is 17 ppm/° C.; various researchers list the CTE of silicon as 2.6-4.2 ppm/° C. The coefficients of thermal expansion are important because the manufacturing process typically requires thermal cycles, and mismatches in CTE between materials in a stacked configuration result in mechanical stresses that can damage the board, or components attached to it. Additional thermal cycling is typically present during operation of the board, but usually this variation is less than during manufacturing and assembly. In recent years, imprinting methods have been developed for several products. An example is the compact disc (CD) that has been manufactured by pressing a master tool into a plastic material, leaving an imprint of the desired pattern. A feature size of one micron and a fabrication cost less than a dollar per square foot have been reported. For both integrated circuit manufacture and printed circuit board manufacture, the imprinting method has potential to be an inexpensive patterning method compared with current photolithographic patterning methods. Photolithography has been the mainstay of integrated circuit patterning for many decades; it generally requires highly sophisticated tools for projecting a beam of light through a mask onto photosensitive materials. A fabrication facility to process silicon wafers by this method typically costs more than US$1 B today. By contrast, imprinting requires unsophisticated tools, yet it can produce fine features, smaller than 100 nanometers in some applications. The tools required for imprinting generally include a laminating press with provisions for aligning the layers, and for heating the thermoplastic material to be patterned. Cold embossing has also been developed using glass tools with embossed features etched therein, and UV curable dielectrics. Electroplating is typically used to build up the copper layers, and chemical/mechanical polishing (CMP) is preferably used for planarizing each layer after plating. Imprinting and CMP methods can be combined to implement a dual damascene process using copper as the conductor material. Dual damascene processes are known in the art; “dual” refers to the fact that two depths of copper are implemented: trenches used for creating traces have a lesser depth than cylindrical holes for vias. The combination of tools for imprinting, plating and CMP may cost less than 1% of the cost of equivalent photolithographic tools. Other conductors may be used instead of copper, but copper offers a compelling combination of good electrical and thermal conductivity, adequate mechanical properties (especially in the form of dispersion strengthened copper, to be further discussed), and an infrastructure of existing tools and processes for drilling, electroplating, etching, and polishing at reasonable cost. Liquid crystal display (LCD) panel fabrication plants are now being built for glass panels measuring 1870×2200 mm. The thickness of these glass panels is 0.7 mm, similar to the preferred thickness of 0.6 mm for copper substrates of the current invention. This means that an infrastructure of semiconductor processing equipment, particularly including thin film coating and etching equipment could be adapted to handle copper substrates in panel sizes up to around 2 meters square. This may be useful for coating thin film adhesion layers and seed layers on large panels of the current invention, and for plasma etching dielectric materials, as will be further described. The photolithographic patterning capability for large panels, generally employing step and repeat exposure systems (“steppers”), may also be used for fabricating the embossing tools described herein. The preferred method of imprinting discussed herein uses an embossing tool in the form of a flexible foil, hereinafter called a “toolfoil”. It is also possible to use rigid embossing tools, particularly if release agents are applied to the tool to aid in separation; also if the impressions are shallow they require a relatively small force for release. A release agent comprised of low surface energy material such as teflon is also preferably provided on the toolfoils discussed herein. One method of making a toolfoil is to electroplate nickel in an additive process to create a master or “father” foil. The sidewalls of the plated features preferably have an angle of about 5° to the vertical. This release angle is useful so that negatives of fathers can be made to produce “mothers”, and negatives of mothers are made to produce “sons”, which are the equivalent of photo-tool working plates. Suitable toolfoils can be obtained from Tecan Components Ltd., Dorset, England. If the toolfoil is used to implement a dual damascene process, then two nickel thicknesses are required and two photo-tools (glass masks) will be used in the fabrication of the master. An alternative embodiment of the imprinting method may be used for large patterns that require a step and repeat methodology. Molecular Imprints of Austin, Tex., USA, has developed a step and flash imprint lithography process called S-Fil. In this process, a substrate is coated with an organic planarization layer. Then a low viscosity photo-polymerizable imprint solution is dispensed on the surface. A surface treated transparent template bearing patterned relief structures is aligned over the coated substrate. The template is lowered into contact with the substrate, thereby displacing the solution, filling the imprint field, and trapping the photo-polymerizable imprint solution in the template relief. Irradiation with UV light through the backside of the template cures the solution. The template is then separated from the substrate leaving a relief image on the surface that is a replica of the template pattern. A short halogen etch is used to clear any remaining thin webs of undisplaced material. A subsequent reactive ion etch into the planarization layer may be used to amplify the aspect ratio of the relief image. Liquid crystal polymer (LCP) is a new dielectric material that has recently become available for imprinting applications in the printed circuit board arena. An example of this material is R/Flex 3800 available from Rogers Corp., Circuit Materials Division, Chandler Arizona. It is available with a CTE matched to copper at 17 ppm/° C. Melting points of 280° C. and 315° C. are available, with thickness varying from 25 microns to 100 microns. From 1-10 GHz the dielectric constant is 2.9 and the dissipation factor is 0.002. The moisture uptake is 0.04% by weight (compared with 0.14% for BCB), resulting in good stability for high frequency applications. Dispersion strengthening is a method for improving the strength properties of copper, without seriously affecting its electrical and thermal conductivity. Cold rolled sheets of dispersion strengthened copper (DSC) known as Glidcop are available from SCM Metal Products, Inc., North Carolina. For use as a substrate for a printed circuit of the current invention, this material is available in thickness ranging from 125-625 microns. By incorporating minute amounts of aluminum oxide to pin the grain boundaries of the copper, the yield strength of DSC is typically improved by about 10 times, while the thermal and electrical properties are degraded by less than 1%. Electroplating methods are well known in the art. Current processes support fabrication of via structures with aspect ratios (depth:diameter) as great as 10. Using layered plating solutions and sophisticated power supplies including reverse pulse biasing, void-free plated structures are achievable. CMP is also well known in the art. A substrate to be polished is held in a polishing chuck so that typically one third of its edge dimension extends below the chuck. A polishing slurry is provided between the exposed surface and a rotating wheel having a finely textured surface; the substrate may simultaneously rotate and orbit in a planetary motion with respect to the wheel. The desired result is a polished planar surface with clearly defined copper features embedded in the dielectric resin. Modem computer circuits such as multi-chip modules for computer server applications typically operate at GHz frequencies and with large power supply currents at low operating voltages: 200 amps at 1.0V is a typical requirement. Cooling of the module is a critical issue, and building such circuits on a copper substrate can help address the cooling requirements. In addition, a “copper sandwich” will be described having integral copper plates at both the top and bottom of the assembly for improved ruggedness and better thermal access to the heat-producing chips. Flip chip assembly is generally recognized as the most advanced assembly method in terms of system density and performance. It enables bare integrated circuit (IC) chips to be assembled, in preference to packaged parts. The chips can have area arrays of input/output ( 1 /O) bonding pads, rather than just at the chip periphery. Inductance of these chip-to-board connections is substantially lower than that of wire bonds, and power pins can be located close to the circuit blocks that need the power. Advanced flip chip assembly methods have recently been reported. One such method is to provide gold stud bumps on the IC chips, and corresponding wells filled with solder on the board. This structure supports pad pitches of 100 microns or less and also routine replacement of defective die using a rework process. There have been two major impediments to the integration of large systems that are exclusively or primarily assembled using flip chip assembly methods: the inability to effectively test such a system (particularly a functional test at full system speed), and the inability to rework defective chips in the assembly. For these reasons, many flip chip assemblies have been limited to 10 IC chips or fewer, because the cost of scrapping defective assemblies becomes prohibitive with a greater number of chips. Solutions to these problems have been recently proposed. Firstly, a special-purpose test chip or chips may be provided on the board under test; working together with a test support computer this chip can provide the means to functionally test the module at full system speed. The test chip preferably includes high speed sampling circuits and comparators that are under control of the support computer. The support computer performs low speed testing chores such as boundary scan and loading of test files, and also hosts diagnostic software for aiding a test operator in determining which chips need to be replaced, if any. Secondly, the proposed variation of flip chip assembly allows effective rework of defective chips. In summary, the rework method is as follows. The board is placed on a hot plate and the temperature is raised to a level just below the melting point of the solder in the wells (the preferred melting point of the preferred In:Ag solder is 143° C.). Then a rework wand emitting hot inert gas is directed at the backside of the defective chip; the solder in the wells melts for this chip, but not for neighboring chips that are not defective. Focused infra red systems have also been deployed for heating the area local to a single chip without melting the solder of surrounding chips. After the solder of the defective chip is molten, the stud bumps are withdrawn from the wells, the surface is inspected and cleaned as necessary, the wells are touched up with additional solder paste as required, and a replacement part is picked, flipped, aligned, and inserted. After re-flowing the solder for the replacement part and validating the assembly with another module test, the rework cycle is complete. There is preferably no epoxy under layer beneath the defective chip (whose removal would be labor intensive, difficult, and potentially damaging to the board). Also, there are no delicate traces around or near the I/O pads that can be damaged during the rework process; the receiving terminal becomes the solder paste in the well rather than the pad. Finally, the materials used easily tolerate the rework temperatures. These factors result in a rework procedure that may be repeated as many times as necessary, enabling the integration of systems comprising hundreds or thousands of IC chips, assembled onto a single monolithic high performance substrate (or blade). This high level of integration in turn enables supercomputer architectures of the current invention. The purpose of the epoxy under layer between chip and board is to prevent mechanical failure such as cracking that can arise from stresses accompanying temperature excursions that occur during manufacturing or operation. Part of the justification for eliminating this under layer in the proposed flip chip mounting structure is that the preferred arrangement of gold stud bumps inserted into wells filled with solder is mechanically stronger (shear forces can not easily detach a stud bump from its pad or a well from its pad). Because the stud bumps are formed from gold, and because gold is one of the most ductile materials, and because the proposed stud bumps have a pointed shape, the proposed structure is also more mechanically compliant than previous structures such as solder balls re-flowed onto matching lands. In addition, the low melting point of the proposed indium based solder (143° C.) results in lower thermal strains than would occur with commonly used solders that melt at higher temperatures (63:37 Sn:Pb solder melts at 183° C.). Even with this improved flip chip attachment it may be necessary to limit the maximum chip size in the proposed assembly structures, to limit the stress imposed. For interconnecting modules, module access cables have been proposed that use a similar arrangement of stud bumps and wells as described for attaching the IC chips. These module access cables can support pin pitches of 100 microns or less, and should be re-workable using the same method as outlined for reworking the IC chips. | <SOH> SUMMARY OF THE INVENTION <EOH>The current invention is intended to address the need for microelectronic assemblies that support operating frequencies of the order of 10 GHz (data rates of the order of 10 Gbps), and power supply currents of several hundred amps. An alternative application is to make lower performance electronic assemblies (sub 1 GHz) less expensively than using current printed circuit board and assembly methods. The preferred embodiment has a base copper layer for mechanical support. A method is described for fabricating feedthroughs in the copper substrate for signals and power. By alternately fabricating layers of dielectric resin and copper conductors, a printed circuit with multiple power and signal planes is built up. Imprinting is used to pattern the layers, preferably using nickel toolfoils. A special assembly layer is preferably fabricated on top of the interconnection circuit wherein a well filled with solder paste is provided at each I/O pad of the board. IC chips are provided with a gold stud bump at each of their I/O pads, and the chips are assembled onto the board by inserting the stud bumps into the wells, then melting the solder to form mechanical and electrical connections. In the preferred embodiment, no epoxy under layer is used between the IC chips and the board. After all the chips are assembled, tested, and reworked as required, a top copper plate may be attached to the backsides of the assembled IC chips, to make a robust mechanical, electrical and thermal package at the module level. An alternate embodiment supports fabrication of modules such as multi-chip modules (MCMs) or system in package (SIP) devices that are integrated onto a motherboard. The motherboard may be a conventional board employing glass-epoxy laminate for example, or a large interconnection circuit fabricated on a copper substrate using methods described herein. For either case, the copper substrate of the attached module is preferably provided with feeds for power and signals that pass through it and connect to the motherboard, typically on a 1 mm grid. In the preferred embodiment, imprinting is used to pattern thermo-plastic dielectric layers, and copper conductors are employed. LCP is the preferred dielectric material and DSC is the preferred form of copper for the base layer. After CMP has been used to polish and planarize the surface of a preceding layer, the following sequence summarizes the steps to form the next pair of interleaved dielectric and conducting layers: a) place a sheet of LCP on top of the polished planar assembly b) mount a toolfoil on a rigid carrier, align and position on top of the LCP sheet c) apply heat to soften the LCP d) apply pressure to imprint the LCP e) cool to room temperature and separate toolfoil from its carrier f) peel the toil foil away from the assembly g) dry etch or sputter etch any remaining web of dielectric material, to expose the copper patterns underneath h) sputter deposit an adhesion layer such as Ti plus a seed layer of Cu i) plate Cu to the desired thickness, typically 3-5 microns in the trenches, some of which is removed in the following step j) CMP to delineate the Cu patterns and planarize the surface A variation of this imprinting procedure will be described for forming the special assembly layer having wells at each of the I/O pads of the interconnection circuit. “Imprinting” and “embossing” are used interchangeably in this application. These techniques are employed to create copper-faced modules configured as blade servers, plus their integration into liquid-cooled supercomputers of the current invention. | 20040220 | 20080805 | 20050224 | 69852.0 | 0 | CLARK, SHEILA V | INTERCONNECTION CIRCUIT AND ELECTRONIC MODULE UTILIZING SAME | SMALL | 0 | ACCEPTED | 2,004 |
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10,783,735 | ACCEPTED | Fibrillation/tachycardia monitoring and preventive system and methodology | A cardiac assist device senses conditions of a heart and controls the generation of various electrical stimuli in response to sense conditions of the heart. The cardiac assist device generates a electrical pulse so as to defibrillate a fibrillated heart when the cardiac assist device determines from the sensed conditions a state of fibrillation. The cardiac assist device generates a chaos control electrical signal so as to bring a pre-fibrillated heart condition back into a normal beating condition when the cardiac assist device determines from the sensed conditions a pre-state of fibrillation. Lastly, the cardiac assist device generates an electrical enhancement signal that causes a threshold of pacing cells in the heart to be exceeded in response to a subthreshold stimulus when the cardiac assist device determines from the sensed conditions a subthreshold pacing signal. | 1. A cardiac assist device, comprising: a primary device housing; a sensor to sense conditions of a heart; and a lead system to transmit and receive signals between the heart and said primary housing; said primary device housing including, a control circuit, in operative communication with said sensor, to control generation of various electrical stimuli in response to sense conditions of the heart, a chaos control generator to generate an electrical signal so as to bring a pre-fibrillated heart condition back into a normal beating condition when said control circuit determines from the sensed conditions a pre-state of fibrillation, and a pacing environment enhancement generator to generating an electrical enhancement signal that causes a threshold of pacing cells in the heart to be exceeded in response to a subthreshold stimulus when control circuit determines from the sensed conditions a subthreshold pacing signal. 2. The cardiac assist device as claimed in claim 1, wherein said electrical enhancement signal comprises a noise signal. 3. The cardiac assist device as claimed in claim 1, wherein said electrical enhancement signal comprises a periodic signal. 4. The cardiac assist device as claimed in claim 1, wherein said electrical enhancement signal comprises a high frequency deterministic signal. 5. The cardiac assist device as claimed in claim 1, wherein said electrical enhancement signal comprises a randomly fluctuating intensity signal. 6. The cardiac assist device as claimed in claim 1, wherein said electrical enhancement signal comprises a randomly fluctuating frequency signal. 7. The cardiac assist device as claimed in claim 1, wherein said electrical enhancement signal is modulated in response to the sensed subthreshold pacing signal. 8. The cardiac assist device as claimed in claim 1, wherein said sensor comprises a two-dimensional high resolution touch sensitive patch attached to the heart to provide fast frames of pressure readings from a two-dimensional array of individual pressure sites. 9. The cardiac assist device as claimed in claim 1, wherein said sensor comprises a two-dimensional high resolution patch to measure, capacitively, a voltage waveform traveling across the heart. 10. The cardiac assist device as claimed in claim 9, wherein said two-dimensional high resolution patch comprises a two-dimensional array of individual non-destructive floating-gate charge-sensing amplifiers. 11. The cardiac assist device as claimed in claim 1, wherein said primary device housing further includes a defibrillation circuit to generate a electrical pulse so as to defibrillate a fibrillated heart when said control circuit determines from the sensed conditions a state of fibrillation. 12. The cardiac assist device as claimed in claim 1, wherein said lead system comprises a fiber optic based communication system. 13. The cardiac assist device as claimed in claim 1, wherein said lead system comprises a plurality of electrical leads. 14. The cardiac assist device as claimed in claim 13, wherein said plurality of electrical leads have a shielding therearound, said shielding preventing said electrical leads from conducting stray electromagnetic interference. 15. The cardiac assist device as claimed in claim 14, wherein said shielding is a metallic sheath to prevent said electrical leads from conducting stray electromagnetic interference. 16. The cardiac assist device as claimed in claim 14, wherein said shielding is a carbon composite sheath to prevent said electrical leads from conducting stray electromagnetic interference. 17. The cardiac assist device as claimed in claim 14, wherein said shielding is a polymer composite sheath to prevent said electrical leads from conducting stray electromagnetic interference. 18. The cardiac assist device as claimed in claim 13, wherein each electrical lead includes an electrical filter, said electrical filter removing stray electromagnetic interference from a signal being received from said electrical lead. 19. The cardiac assist device as claimed in claim 18, wherein said plurality of electrical leads have a shielding therearound, said shielding preventing said electrical leads from conducting stray electromagnetic interference. 20. The cardiac assist device as claimed in claim 19, wherein said shielding is a carbon composite sheath to prevent said electrical leads from conducting stray electromagnetic interference. 21. The cardiac assist device as claimed in claim 19, wherein said shielding is a polymer composite sheath to prevent said electrical leads from conducting stray electromagnetic interference. 22. A method for assisting a heart beat normally, comprising: (a) sensing conditions of a heart; (b) determining a state of the heart from the sensed conditions; (c) generating a control electrical signal so as to bring a pre-fibrillated heart condition back into a normal beating condition when the determined state of the heart is a pre-state of fibrillation, and (d) generating an electrical enhancement signal that causes a threshold of pacing cells in the heart to be exceeded in response to a subthreshold stimulus when the determined state of the heart is a state associated with a subthreshold pacing signal. 23. The method as claimed in claim 22, wherein the electrical enhancement signal comprises a noise signal. 24. The method as claimed in claim 22, wherein the electrical enhancement signal comprises a periodic signal. 25. The method as claimed in claim 22, wherein the electrical enhancement signal comprises a high frequency deterministic signal. 26. The method as claimed in claim 22, wherein the electrical enhancement signal comprises a randomly fluctuating intensity signal. 27. The method as claimed in claim 22, wherein the electrical enhancement signal comprises a randomly fluctuating frequency signal. 28. The method as claimed in claim 22, wherein the electrical enhancement signal is modulated in response to the sensed subthreshold pacing signal. 29. The method as claimed in claim 22, wherein the conditions of the heart are sensed by measuring pressure waves upon a surface of the heart. 30. The method as claimed in claim 22, wherein the conditions of the heart are sensed by capacitively measuring a voltage waveform traveling across the heart. 31. The method as claimed in claim 22, further comprising: (e) generating a electrical pulse so as to defibrillate a fibrillated heart when the determined state of the heart is a state of fibrillation; | CROSS REFERENCE TO RELATED PATENT APPLICATIONS The subject matter of co-pending U.S. patent application Ser. No. 09/885,867, filed on Jun. 20, 2001, entitled “Controllable, Wearable MRI-Compatible Cardiac Pacemaker With Pulse Carrying Photonic Catheter And VOO Functionality”; co-pending U.S. patent application Ser. No. 09/885,868, filed on Jun. 20, 2001, entitled “Controllable, Wearable MRI-Compatible Cardiac Pacemaker With Power Carrying Photonic Catheter And VOO Functionality”; co-pending U.S. patent application Ser. No. 10/037,513, filed on Jan. 4, 2002, entitled “Optical Pulse Generator For Battery Powered Photonic Pacemakers And Other Light Driven Medical Stimulation Equipment”; co-pending U.S. patent application Ser. No. 10/037,720, filed on Jan. 4, 2002, entitled “Opto-Electric Coupling Device For Photonic Pacemakers And Other Opto-Electric Medical Stimulation Equipment”; co-pending U.S. patent application Ser. No. 09/943,216, filed on Aug. 30, 2001, entitled “Pulse Width Cardiac Pacing Apparatus”; co-pending U.S. patent application Ser. No. 09/964,095, filed on Sep. 26, 2001, entitled “Process for Converting Light”; co-pending U.S. patent application Ser. No. 09/921,066, filed on Aug. 2, 2001, entitled “MRI-Resistant Implantable Device”; co-pending U.S. patent application Ser. No. 10/077,842, filed on Feb. 19, 2002, entitled “An Electromagnetic Interference Immune Tissue Invasive System”; co-pending U.S. patent application Ser. No. 10/077,823, filed on Feb. 19, 2002, entitled “An Electromagnetic Interference Immune Tissue Invasive System”; co-pending U.S. patent application Ser. No. 10/077,887, filed on Feb. 19, 2002, entitled “An Electromagnetic Interference Immune Tissue Invasive System”; co-pending U.S. patent application Ser. No. 10/077,883, filed on Feb. 19, 2002, entitled “An Electromagnetic Interference Immune Tissue Invasive System”; and co-pending U.S. patent application Ser. No. 10/077,958, filed on Feb. 19, 2002, entitled “An Electromagnetic Interference Immune Tissue Invasive System”. The entire content of each of the above noted co-pending U.S. patent application Ser. No. 09/885,867; 09/885,868; 10/037,513; 10/037,720; 09/943,216; 09/964,095; 09/921,066; 10/077,842; 10/077,823; 10/077,887; 10/077,883; and 10/077,958 is hereby incorporated by reference. FIELD OF THE PRESENT INVENTION The present invention relates generally to an implantable device that is capable of monitoring cardiac conditions and preventing tachycardia. More particularly, the present invention is directed to an implantable system that monitors cardiac electrical signals to determine a convergence upon uniformity and applies electrical noise into the cardiac environment to break-up the convergence upon uniformity. BACKGROUND OF THE PRESENT INVENTION The heart is a series of pumps that are carefully controlled by a very special electrical system. This electrical system attempts to regulate the heart rate between 60 and 100 beats per minute. With normal conduction, the cardiac contractions are very organized and timed so that the top chambers (the atria) contract before the lower chambers and the heart rate is maintained between 60 and 100 beats per minute. Abnormally fast heart rates, called tachycardias, occur when the ventricular chambers beat too quickly. In such an instance, the ventricles may not be able to fill with enough blood to supply the body with the oxygen rich blood that it needs. Conventionally, ventricular tachycardia (“VT”) has been controlled by medication and electrical methods. The most common conventional electrical therapy for VT is implantation of a device known as an Implantable Cardioverter Defibrillator or ICD. The conventional ICD applies an electric shock to the heart muscle to interrupt or disrupt the fast rhythm. The electric shock may be in the form of specially timed pacemaker pulses (unfelt by the patient), called antitachycardia pacing, and/or by high voltage shock. The high voltage shock, if required, is usually felt by the patient. Cardiac pacers, which provide stimulation to a patient's heart, by means of amplitude and frequency modulated electrical pulses, have been developed for permanent or temporary applications. The two most common types of cardiac pacers currently in use are pacemakers and implantable cardioverter-defibrillators (ICD). Cardiac pacers can be implanted in a suitable location inside the patient's body or located outside the patient's body. The human heart may suffer from two classes of rhythmic disorders or arrhythmias: bradycardia and tachyarrhythmia. Bradycardia occurs when the heart beats too slowly, and may be treated by a common implantable pacemaker delivering low voltage (about 3 V) pacing pulses. The conventional implantable pacemaker is usually contained within a hermetically sealed enclosure, in order to protect the operational components of the device from the harsh environment of the body, as well as to protect the body from the device. This implantable pacemaker operates in conjunction with one or more electrically conductive leads, adapted to conduct electrical stimulating pulses to sites within the patient's heart, and to communicate sensed signals from those sites back to the implanted device. Furthermore, the conventional implantable pacemaker typically has a metal case and a connector block mounted to the metal case that includes receptacles for leads which may be used for electrical stimulation or which may be used for sensing of physiological signals. The battery and the circuitry associated with the common implantable pacemaker are hermetically sealed within the case. Electrical interfaces are employed to connect the leads outside the metal case with the medical device circuitry and the battery inside the metal case. Electrical interfaces serve the purpose of providing an electrical circuit path extending from the interior of a hermetically sealed metal case to an external point outside the case while maintaining the hermetic seal of the case. A conductive path is provided through the interface by a conductive pin that is electrically insulated from the case itself. Such interfaces typically include a ferrule that permits attachment of the interface to the case, the conductive pin, and a hermetic glass or ceramic seal that supports the pin within the ferrule and isolates the pin from the metal case. In all of the conventional electrical stimulus devices, the conventional ICD senses a fibrillation or tachycardia cardiac state and proceeds to use various measures to bring the heart out of the fibrillation or tachycardia, through defibrillation by antitachycardia pacing, and/or by high voltage shock. In other words, the heart has already reached a dangerous state before the conventional ICDs provide any stimulus to rectify the problem. Therefore, it is desirable to have a device that can sense or detect an approaching fibrillation or tachycardia cardiac state and take remedial actions prior to the heart entering a dangerous state. Moreover, it is desirable to have a device that can sense or detect a failure of remedial actions and provide, as a backup remedy, the conventional defibrillation by antitachycardia pacing, and/or by high voltage shock. SUMMARY OF THE PRESENT INVENTION A first aspect of the present invention is a cardiac assist device. The cardiac assist device includes a primary device housing; a sensor to sense conditions of a heart; and a lead system to transmit and receive signals between the heart and the primary housing. The primary device housing includes a control circuit, in operative communication with the sensor, to control generation of various electrical stimuli in response to sense conditions of the heart; a chaos control generator to generate an electrical signal so as to bring a pre-fibrillated heart condition back into a normal beating condition when the control circuit determines from the sensed conditions a pre-state of fibrillation; and a pacing environment enhancement generator to generating an electrical enhancement signal that causes a threshold of pacing cells in the heart to be exceeded in response to a subthreshold stimulus when control circuit determines from the sensed conditions a subthreshold pacing signal. A second aspect of the present invention is a method for assisting a heart beat normally. The method senses conditions of a heart; determines a state of the heart from the sensed conditions; generates a control electrical signal so as to bring a pre-fibrillated heart condition back into a normal beating condition when the determined state of the heart is a pre-state of fibrillation, and generates an electrical enhancement signal that causes a threshold of pacing cells in the heart to be exceeded in response to a subthreshold stimulus when the determined state of the heart is a state associated with a subthreshold pacing signal. BRIEF DESCRIPTION OF THE DRAWINGS The present invention may take form in various components and arrangements of components, and in various steps and arrangements of steps. The drawings are only for purposes of illustrating a preferred embodiment and are not to be construed as limiting the present invention, wherein: FIG. 1 illustrates one embodiment of a cardiac assist system according to the concepts of the present invention; FIG. 2 illustrates an example of a Poincaré map used by the present invention to manage the generation of electrical stimulus during a pre-fibrillation stage; FIGS. 3 and 4 illustrate further embodiments of a cardiac assist system according to the concepts of the present invention; and FIG. 5 is a flowchart illustrating the management of a heart according to the concepts of the present invention. DETAILED DESCRIPTION OF THE PRESENT INVENTION The present invention will be described in connection with preferred embodiments; however, it will be understood that there is no intent to limit the present invention to the embodiments described herein. On the contrary, the intent is to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the present invention as defined by the appended claims. For a general understanding of the present invention, reference is made to the drawings. In the drawings, like reference have been used throughout to designate identical or equivalent elements. It is also noted that the various drawings illustrating the present invention are not drawn to scale and that certain regions have been purposely drawn disproportionately so that the features and concepts of the present invention could be properly illustrated. Current medical research has demonstrated that fibrillation has three detectable stages wherein some intervention is needed by the second stage to prevent fibrillation or actual intervention at the third stage to cause defibrillation. Moreover, from this research, it appears that fibrillation is not necessarily an immediate situation, but fibrillation is a breaking down, over a period of time, of a stable cardiac system into a chaotic cardiac system to finally a pseudo-random cardiac system and heart failure. Of the stages discussed above, the first stage is a warning stage wherein warning signs are produced indicating that the heart beating may be progressing towards the realization of fibrillation; the second stage is the onset of fibrillation, thus intervention is critical to avoid heart failure and the need for a defibrillation stimulus to bring the heart back into proper rhythm. It is these first two stages that the present invention provides a non-defibrillation stimulus to bring the heart back into proper rhythm. Moreover, the present invention proposes a pre-warning stage wherein a sub-threshold stimulus is provided as a preventive means to avoid the heart from entering the first warning stage of fibrillation. As illustrated in FIG. 1, a medical device 12 is provided to monitor the conditions of the heart and to provide proper stimulus as dictated by the monitored conditions. Although this embodiment of FIG. 1 illustrates the medical device 12 as implantable, the medical device 12 may be implantable or non-implantable. Stimulus leads 14 and 15 are connected to the medical device 12 in connector block region 13 using an interface. It is noted that stimulus leads 14 and 15 may be a fiber optic based communication system wherein the fiber optic communication system contains at least one channel within a multi-fiber optic bundle. The fiber optic based communication system is covered with a biocompatible material wherein the biocompatible material is a non-permeable diffusion resistant biocompatible material. The stimulus leads 14 and 15 may also be a plurality of electrical leads that have a shield therearound to prevent the electrical leads from conducting stray electromagnetic interference. This shield may be a metallic sheath, a carbon composite sheath, or a polymer composite sheath to prevent the electrical leads from conducting stray electromagnetic interference. In addition to the shield or in lieu of the shield, each electrical lead may include an electrical filter wherein the electrical filter removes stray electromagnetic interference from a signal being received from the electrical lead. The electrical filter may comprise capacitive and inductive filter elements adapted to filter out predetermined frequencies of electromagnetic interference. The shield is covered with a biocompatible material wherein the biocompatible material is a non-permeable diffusion resistant biocompatible material. The stimulus leads 14 and 15 may be unipolar leads, bipolar leads, or a combination of unipolar and bipolar leads. The stimulus leads 14 and 15 may also be a combination of a fiber optic based communication system and electrical leads. Moreover, the stimulus leads 14 and 15 may be defibrillator leads. The stimulus leads 14 and 15 may also include a detection circuit (not shown) to detect a phase timing of an external electromagnetic field such that a control circuit alters its operations to avoid interfering with the detected external electromagnetic field. As further illustrated in FIG. 1, a cardiac sensor lead 18 with associated sensor 20 is connected to the implantable medical device 12 in connector block region 13 using an interface. As discussed above, the present invention provides a means for sensing the cardiac conditions and also provides a means for generating stimuli in response thereto. With respect to monitoring the cardiac conditions, one embodiment of the present invention contemplates that the sensor 20 is a two-dimensional high-definition (high resolution) touch sensitive patch attached to the heart that provides fast frames of pressure readings from individual pressure sites for the two-dimensional area of interest. In this embodiment, the sensor 20 provides pressure readings from the sensed pressure pulses. These pressure readings are correlated to the pulsing of the heart muscle by a microprocessor located within the implantable medical device 12. In another embodiment of the present invention, the sensor 20 is a two-dimensional high-definition (high resolution) patch that can measure, capacitively, the voltage. The voltage sensitive sites would be, for example, individual non-destructive floating-gate charge-sensing amplifiers located in very defined areas without affecting the voltage in other areas. According to the concepts of the present invention, the information received from the sensor 20 is processed by the microprocessor so as to generate information that is equivalent to a Poincaré map of the sensed situation. Upon this information being internally mapped by the microprocessor, the sequence of the data points is used to determine the stable and unstable directions of the Poincaré map. An example of this determination is illustrated by FIG. 2 wherein the determined stable 120 and unstable 110 directions (manifolds) and the unity line 130 of the Poincaré map 100 are shown. A normal functioning heart will have its points lying along or in very close proximity to the stable manifold 120. As shown in FIG. 2, point B represent a condition wherein the system is beginning to become unstable and in the case of the present invention, the heart is showing warning signs of fibrillation. Therefore, when a condition represented by point B of FIG. 2 is sensed by the present invention, a signal is generated to bring the point from B to B′. In other words, the signal generated by the present invention provides chaos control by bringing the condition (B), as illustrated by a Poincaré map, to a new condition (B′) that lies along or is in very close proximity to the stable manifold 120 of the Poincaré map. In other words, the present invention provides a stimulus to prevent fibrillation. According to the concepts of the present invention the stimulus can be managed in amplitude, frequency, and timing (modulation) to be effective. Moreover, the stimulus may be either positive (in that it enhances the natural signal being generated by the heart) or negative (in that is blocks, dampens, or diminishes the natural signal being generated by the heart). The stimulus brings the sensed conditions back to a normal state (points on the Poincaré map back to unity). Simply put the control unit of the present invention translates the measured conditions into Poincaré space, find the difference between a stable condition in Poincaré space and the measured condition in Poincaré space, and translate the Poincaré space difference to a voltage, current, power, or drug stimulus space so that effective treatment can be realized. Thus, instead of powerful electric jolts from defibrillator paddles to restore a normal heartbeat, the present invention provides a more gentle stimulation during an early warning stage of fibrillation so as to prevent the full onslaught of fibrillation so as to avoid unnecessary harm or discomfort to the patient. FIG. 3 illustrates another embodiment of the present invention. As illustrated in FIG. 3, a primary housing 400 includes a control unit 410 that manages the overall operations of the cardiac assist system or device. The control unit 410 is operatively connected to a memory unit 420 that stores the applications needed to control the cardiac assist device as well as the data associated with the sensed conditions of the heart. For illustrative purposes, the cardiac assist device of FIG. 3 includes a fiber optic communication system comprising an optical bundle 300 having optical fibers 310 and 320; lasers 440 and 210 to provide optical pulses between the primary housing 400 and a secondary housing 200; photodiodes 450 and 260 to convert the optical pulses to electrical data signals; and drivers 210 and 340 to convert electrical signals into control signals that cause the optical pulses to be generated. It is noted that the fiber optic communication system can be replaced with an electrical system, an acoustic system, or a radio transmission system. In such cases the various components described above would be replaced with their equivalent corresponding components. It is further noted that the fiber optic communication system contains at least one channel within a multi-fiber optic bundle. The fiber optic based communication system is covered with a biocompatible material wherein the biocompatible material is a non-permeable diffusion resistant biocompatible material. The communication system may also be a plurality of electrical leads that have a shield therearound to prevent the electrical leads from conducting stray electromagnetic interference. This shield may be a metallic sheath, a carbon composite sheath, or a polymer composite sheath to prevent the electrical leads from conducting stray electromagnetic interference. In addition to the shield or in lieu of the shield, each electrical lead may include an electrical filter wherein the electrical filter removes stray electromagnetic interference from a signal being received from the electrical lead. The electrical filter may comprise capacitive and inductive filter elements adapted to filter out predetermined frequencies of electromagnetic interference. The shield is covered with a biocompatible material wherein the biocompatible material is a non-permeable diffusion resistant biocompatible material. The communication system may be unipolar leads, bipolar leads, or a combination of unipolar and bipolar leads. The communication system may also be a combination of a fiber optic based communication system and electrical leads. The communication system may also include a detection circuit (not shown) to detect a phase timing of an external electromagnetic field such that a control circuit alters its operations to avoid interfering with the detected external electromagnetic field. FIG. 3 further illustrates a secondary housing 200 that includes a control unit 270. The control unit 270 is in operative communication with control unit 410 of the primary housing. It is noted that the cardiac assist device of the present invention may be constructed in a single housing and thus only a single control unit would be needed, as will be described below in more detail with respect to FIG. 4. The secondary housing 200 further includes a sensor 230 to sense the conditions, of the heart. The sensor 230 may be integral to the secondary housing 200 or operatively connected to the secondary housing through optical or electrical leads, or a combination thereof. With respect to monitoring the cardiac conditions, one embodiment of the present invention contemplates that the sensor 230 is a two-dimensional high-definition (high resolution) touch sensitive patch attached to the heart that provides fast frames of pressure readings from individual pressure sites for the two-dimensional area of interest. In this embodiment, the sensor 230 provides pressure readings from the sensed pressure pulses. These pressure readings are correlated to the pulsing of the heart muscle by the control unit 410. In another embodiment of the present invention, the sensor 230 is a two-dimensional high-definition (high resolution) patch that can measure, capacitively, the voltage. The voltage sensitive sites would be, for example, individual non-destructive floating-gate charge-sensing amplifiers located in very defined areas without affecting the voltage in other areas. In a preferred embodiment of the present invention, the information received from the sensor 230 is processed by the control unit 410 so as to generate information that is equivalent to a Poincaré map of the sensed situation. Upon this information being internally mapped by the control unit 410, the sequence of the data points is used to determine the stable and unstable directions of the Poincaré map. The mapped information is stored in memory 420 for use by the control unit 410. It is noted that various memory management schemes, such as compression techniques, may be used to effectively store the required amount of data necessary for proper analysis by the control unit 410. It is preferred that the mapped information be analyzed in its compressed state to conserve memory space. If a two-dimensional sensor is utilized, the secondary housing 200 would include a frame memory 240 and a register 250 to convert the two-dimensional array of data into a serial data to be transmitted to the primary housing 400. The control unit 270 controls the operations of a subthreshold stimulus generator 287, a chaos management generator 280, and a defibrillation pulse generator 285. These various generators are connected to an electrode 290 that is connected to the heart. When the control unit 410 determines that the natural pacing signal of the heart falls below a threshold to trigger the heart to beat, the control unit 410 generates a signal to control unit 270 instructing the control unit 270 to activate the subthreshold stimulus generator 287. Subthreshold stimulus generator 287 generates a signal that causes a threshold of pacing cells in the heart to be exceeded in response to a subthreshold pacing signal or natural stimulus. The signal generated by the subthreshold stimulus generator 287 may be a noise signal; a periodic signal; a high frequency deterministic signal; a randomly fluctuating intensity signal; a randomly fluctuating frequency signal; or any combination thereof The signal generated by the subthreshold stimulus generator 287 may also be modulated in response to the sensed subthreshold pacing signal. When the control unit 410 determines that the state of the heart is entering in a pre-fibrillation stage, the control unit 410 generates a signal to control unit 270 instructing the control unit 270 to activate the chaos management generator 280. Chaos management generator 280 generates a signal that prevents the onslaught of fibrillation. The stimulus can be managed in amplitude, frequency, and timing (modulation) to be effective. Moreover, the stimulus may be either positive (in that it enhances the natural signal being generated by the heart) or negative (in that is blocks, dampens, or diminishes the natural signal being generated by the heart). The stimulus brings the sensed conditions back to a normal state (points on the Poincaré map back to unity). Lastly, when the control unit 410 determines that the state of the heart is in a fibrillation stage, the control unit 410 generates a signal to control unit 270 instructing the control unit 270 to activate the defibrillation pulse generator 285. Defibrillation pulse generator 285 generates a high voltage pulse to defibrillate the heart. FIG. 4 illustrates another embodiment of the present invention that includes a housing 500 and a control unit 570 therein. The housing 500 is operatively connected to a sensor 530 to sense the conditions of the heart. The sensor 530 may be integral to the housing 500 or operatively connected to the housing through optical or electrical leads, or a combination thereof With respect to monitoring the cardiac conditions, one embodiment of the present invention contemplates that the sensor 530 is a two-dimensional high-definition (high resolution) touch sensitive patch attached to the heart that provides fast frames of pressure readings from individual pressure sites for the two-dimensional area of interest. In this embodiment, the sensor 530 provides pressure readings from the sensed pressure pulses. These pressure readings are correlated to the pulsing of the heart muscle by the control unit 570. In another embodiment of the present invention, the sensor 530 is a two-dimensional high-definition (high resolution) patch that can measure, capacitively, the voltage. The voltage sensitive sites would be, for example, individual non-destructive floating-gate charge-sensing amplifiers located in very defined areas without affecting the voltage in other areas. In a preferred embodiment of the present invention, the information received from the sensor 530 is processed by the control unit 570 so as to generate information that is equivalent to a Poincaré map of the sensed situation. Upon this information being internally mapped by the control unit 570, the sequence of the data points is used to determine the stable and unstable directions of the Poincaré map. The mapped information is stored in second memory 545 for use by the control unit 570. It is noted that various memory management schemes, such as compression techniques, may be used to effectively store the required amount of data necessary for proper analysis by the control unit 570. It is preferred that the mapped information be analyzed in its compressed state to conserve memory space. If a two-dimensional sensor were utilized, the housing 500 would include a memory 540 to convert the two-dimensional array of data into a serial data to be transmitted to the control unit 570. The control unit 570 controls the operations of a subthreshold stimulus generator 520, a pre-fibrillation control generator 550, and a defibrillation pulse generator 560. These various generators are connected, via pulse bus 580, to an electrode 590 that is connected to the heart. When the control unit 570 determines that the natural pacing signal of the heart falls below a threshold to trigger the heart to beat, the control unit 570 generates a signal to activate the subthreshold stimulus generator 520. Subthreshold stimulus generator 520 generates a signal that causes a threshold of pacing cells in the heart to be exceeded in response to a subthreshold pacing signal or natural stimulus. The signal generated by the subthreshold stimulus generator 520 may be a noise signal; a periodic signal; a high frequency deterministic signal; a randomly fluctuating intensity signal; a randomly fluctuating frequency signal; or any combination thereof The signal generated by the subthreshold stimulus generator 520 may also be modulated in response to the sensed subthreshold pacing signal. When the control unit 570 determines that the state of the heart is entering in a pre-fibrillation stage, the control unit 570 generates a signal to activate the pre-fibrillation control generator 550. Pre-fibrillation control generator 550 generates a signal that prevents the onslaught of fibrillation. The stimulus can be managed in amplitude, frequency, and timing (modulation) to be effective. Moreover, the stimulus may be either positive (in that it enhances the natural signal being generated by the heart) or negative (in that is blocks, dampens, or diminishes the natural signal being generated by the heart). The stimulus brings the sensed conditions back to a normal state (points on the Poincaré map back to unity). Lastly, when the control unit 570 determines that the state of the heart is in a fibrillation stage, the control unit 570 generates a signal to activate the defibrillation pulse generator 560. Defibrillation pulse generator 560 generates a high voltage pulse to defibrillate the heart. The methodology utilized by the present invention is illustrated in FIG. 5. As illustrated in FIG. 5, step S1 senses the conditions of the heart. If it is determined at step S2 that the natural pacing signal of the heart falls below a threshold to trigger the heart to beat, step S3 causes a signal to be generated that causes a threshold of pacing cells in the heart to be exceeded in response to a subthreshold pacing signal or natural stimulus. If it is determined at step S4 that the heart is entering in a pre-fibrillation stage, step S5 causes a signal to be generated that prevents the onslaught of fibrillation. If it is determined at step S6 that the heart is entering a fibrillation stage, step S7 causes a high voltage pulse to be generated to defibrillate the heart. In each of the embodiments described above, the cardiac assist device of the present invention may be contained within a hermetically sealed enclosure, in order to protect the operational components of the device from the harsh environment of the body, as well as to protect the body from the device. The cardiac assist device of the present invention may have a metal case and a connector block mounted to the metal case that includes receptacles for leads which may be used for electrical stimulation or which may be used for sensing of physiological signals. The battery and the circuitry associated with the common implantable pacemaker are hermetically sealed within the case. Electrical interfaces are employed to connect the leads outside the metal case with the medical device circuitry and the battery inside the metal case. Electrical interfaces serve the purpose of providing an electrical circuit path extending from the interior of a hermetically sealed metal case to an external point outside the case while maintaining the hermetic seal of the case. A conductive path is provided through the interface by a conductive pin that is electrically insulated from the case itself. Such interfaces typically include a ferrule that permits attachment of the interface to the case, the conductive pin, and a hermetic glass or ceramic seal that supports the pin within the ferrule and isolates the pin from the metal case. Furthermore, in each of the embodiments described above, the cardiac assist device of the present invention may be constructed to as to be immune or hardened to electromagnetic insult or interference. Although the leads may be fiber optic strands or electrical leads with proper shielding, the actual interface to the tissue, the electrodes, cannot be shielded because the tissue needs to receive the stimulation from the device without interference. This causes the electrodes to be susceptible to electromagnetic interference or insult, and such insult can cause either damage to the tissue area or the circuitry at the other end. To realize immunity from the electromagnetic interference or insult, each electrode has an anti-antenna geometrical shape. The anti-antenna geometrical shape prevents the electrode from picking up and conducting stray electromagnetic interference. While various examples and embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that the spirit and scope of the present invention are not limited to the specific description and drawings herein, but extend to various modifications and changes all as set forth in the following claims. | <SOH> BACKGROUND OF THE PRESENT INVENTION <EOH>The heart is a series of pumps that are carefully controlled by a very special electrical system. This electrical system attempts to regulate the heart rate between 60 and 100 beats per minute. With normal conduction, the cardiac contractions are very organized and timed so that the top chambers (the atria) contract before the lower chambers and the heart rate is maintained between 60 and 100 beats per minute. Abnormally fast heart rates, called tachycardias, occur when the ventricular chambers beat too quickly. In such an instance, the ventricles may not be able to fill with enough blood to supply the body with the oxygen rich blood that it needs. Conventionally, ventricular tachycardia (“VT”) has been controlled by medication and electrical methods. The most common conventional electrical therapy for VT is implantation of a device known as an Implantable Cardioverter Defibrillator or ICD. The conventional ICD applies an electric shock to the heart muscle to interrupt or disrupt the fast rhythm. The electric shock may be in the form of specially timed pacemaker pulses (unfelt by the patient), called antitachycardia pacing, and/or by high voltage shock. The high voltage shock, if required, is usually felt by the patient. Cardiac pacers, which provide stimulation to a patient's heart, by means of amplitude and frequency modulated electrical pulses, have been developed for permanent or temporary applications. The two most common types of cardiac pacers currently in use are pacemakers and implantable cardioverter-defibrillators (ICD). Cardiac pacers can be implanted in a suitable location inside the patient's body or located outside the patient's body. The human heart may suffer from two classes of rhythmic disorders or arrhythmias: bradycardia and tachyarrhythmia. Bradycardia occurs when the heart beats too slowly, and may be treated by a common implantable pacemaker delivering low voltage (about 3 V) pacing pulses. The conventional implantable pacemaker is usually contained within a hermetically sealed enclosure, in order to protect the operational components of the device from the harsh environment of the body, as well as to protect the body from the device. This implantable pacemaker operates in conjunction with one or more electrically conductive leads, adapted to conduct electrical stimulating pulses to sites within the patient's heart, and to communicate sensed signals from those sites back to the implanted device. Furthermore, the conventional implantable pacemaker typically has a metal case and a connector block mounted to the metal case that includes receptacles for leads which may be used for electrical stimulation or which may be used for sensing of physiological signals. The battery and the circuitry associated with the common implantable pacemaker are hermetically sealed within the case. Electrical interfaces are employed to connect the leads outside the metal case with the medical device circuitry and the battery inside the metal case. Electrical interfaces serve the purpose of providing an electrical circuit path extending from the interior of a hermetically sealed metal case to an external point outside the case while maintaining the hermetic seal of the case. A conductive path is provided through the interface by a conductive pin that is electrically insulated from the case itself. Such interfaces typically include a ferrule that permits attachment of the interface to the case, the conductive pin, and a hermetic glass or ceramic seal that supports the pin within the ferrule and isolates the pin from the metal case. In all of the conventional electrical stimulus devices, the conventional ICD senses a fibrillation or tachycardia cardiac state and proceeds to use various measures to bring the heart out of the fibrillation or tachycardia, through defibrillation by antitachycardia pacing, and/or by high voltage shock. In other words, the heart has already reached a dangerous state before the conventional ICDs provide any stimulus to rectify the problem. Therefore, it is desirable to have a device that can sense or detect an approaching fibrillation or tachycardia cardiac state and take remedial actions prior to the heart entering a dangerous state. Moreover, it is desirable to have a device that can sense or detect a failure of remedial actions and provide, as a backup remedy, the conventional defibrillation by antitachycardia pacing, and/or by high voltage shock. | <SOH> SUMMARY OF THE PRESENT INVENTION <EOH>A first aspect of the present invention is a cardiac assist device. The cardiac assist device includes a primary device housing; a sensor to sense conditions of a heart; and a lead system to transmit and receive signals between the heart and the primary housing. The primary device housing includes a control circuit, in operative communication with the sensor, to control generation of various electrical stimuli in response to sense conditions of the heart; a chaos control generator to generate an electrical signal so as to bring a pre-fibrillated heart condition back into a normal beating condition when the control circuit determines from the sensed conditions a pre-state of fibrillation; and a pacing environment enhancement generator to generating an electrical enhancement signal that causes a threshold of pacing cells in the heart to be exceeded in response to a subthreshold stimulus when control circuit determines from the sensed conditions a subthreshold pacing signal. A second aspect of the present invention is a method for assisting a heart beat normally. The method senses conditions of a heart; determines a state of the heart from the sensed conditions; generates a control electrical signal so as to bring a pre-fibrillated heart condition back into a normal beating condition when the determined state of the heart is a pre-state of fibrillation, and generates an electrical enhancement signal that causes a threshold of pacing cells in the heart to be exceeded in response to a subthreshold stimulus when the determined state of the heart is a state associated with a subthreshold pacing signal. | 20040220 | 20060328 | 20050825 | 95380.0 | 0 | GETZOW, SCOTT M | FIBRILLATION/TACHYCARDIA MONITORING AND PREVENTIVE SYSTEM AND METHODOLOGY | SMALL | 0 | ACCEPTED | 2,004 |
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10,783,830 | ACCEPTED | Structures and methods for fabricating integrated HBT/FET's at competitive cost | Methods and systems for fabricating integrated pairs of HBT/FET's are disclosed. One preferred embodiment comprises a method of fabricating an integrated pair of GaAs-based HBT and FET. The method comprises the steps of: growing a first set of epitaxial layers for fabricating the FET on a semi-insulating GaAs substrate; fabricating a highly doped thick GaAs layer serving as the cap layer for the FET and the subcollector layer for the HBT; and producing a second set of epitaxial layers for fabricating the HBT. | 1. A structure comprising: a first epitaxial structure on top of the substrate, the epitaxial structure forming a portion of a FET; a second epitaxial structure on top of the first epitaxial structure, the second epitaxial structure being shared by a HBT and the FET; and a third epitaxial structure on top of the second epitaxial structure, the epitaxial structure forming a portion of the HBT. 2. The structure of claim 1, wherein the second epitaxial structure further comprises a contact layer, said contact layer serving as both the cap layer for the FET and the subcollector layer for the HBT. 3. The structure of claim 2, wherein the contact layer is highly doped. 4. The structure of claim 3, wherein the contact layer is a n-type GaAs layer having a doping concentration of approximately 4.0×1018 cm−3 or more. 5. The structure of claim 2, wherein the thickness of the contact layer is determined based on one or more design trade-offs between the HBT and the FET. 6. The structure of claim 2, wherein the thickness of the contact layer is about 350 nm. 7. The structure of claim 1, wherein the first epitaxial structure further comprises a low leakage buffer layer. 8. The structure of claim 7, wherein the low leakage buffer layer further comprises one or more undoped GaAs or AlGaAs layers. 9. The structure of claim 1, wherein the first epitaxial structure further comprises a set of MESFET epitaxial layers. 10. The structure of claim 9, wherein the set of MESFET epitaxial layers further comprises an undoped GaAs spacer layer and a doped GaAs channel layer. 11. The structure of claim 1, wherein the first epitaxial structure further comprises a set of pHEMT epitaxial layers. 12. The structure of claim 11, wherein the set of pHEMT epitaxial layers further comprises a lower GaAs barrier layer, an InGaAs channel layer and an AlGaAs or InGaP Schottky barrier layer. 13. The structure of claim 1, wherein the third epitaxial structure further comprises a GaAs collector layer, a GaAs base layer and a InGaP emitter layer. 14. A method of fabricating integrated HBT and FET on the same substrate, said method comprising the steps of: providing the structure of claim 1; fabricating the HBT from the third epitaxial structure of the structure; forming an isolation barrier in the first and second epitaxial structures of the structure; and, optimizing the FET and the HBT independently. 15. The method of claim 14, wherein the step of forming an isolation further comprises the step of implanting an isolation into the first and the second epitaxial structures of the structure between the HBT and the FET. 16. The method of claim 14, further comprising, between the step of fabricating and the step of forming, the step of depositing a passivation layer on the HBT. 17. An integrated pair of HBT and FET transistors, the HBT and FET sharing a contact layer, said contact layer serving as both the cap layer for the FET and the subcollector layer for the HBT. 18. The integrated pair of HBT and FET transistors of claim 17, wherein the HBT and the FET are isolated by an implanted isolation barrier. 19. The integrated pair of HBT and FET transistors of claim 18, where the isolation barrier is formed using a He+ ion implantation. 20. The integrated pair of HBT and FET transistors of claim 17, where the HBT and FET are GaAs-based transistors. 21. An integrated circuit comprising an integrated pair of HBT and FET transistors of claim 17. 22. A method of fabricating an epitaxial structure for fabricating an integrated pair of GaAs-based HBT and FET, said method comprising the steps of: growing a first set of epitaxial layers, the epitaxial layers forming a portion of the FET on a semi-insulating GaAs substrate; fabricating a highly doped thick GaAs layer serving as the cap layer for the FET and the subcollector layer for the HBT; and, producing a second set of epitaxial layers, the epitaxial layers forming a portion of the HBT. | FIELD OF INVENTION This invention is related in general to HBT/FET fabrication technologies and in particular to structures and methods for fabricating integrated InGaP/GaAs HBT/FET's on the same chip at a competitive cost. BACKGROUND OF INVENTION InGaP/GaAs HBT Technology is very attractive for use in many commercial applications for its excellent reliability and thermal stability. The first generation of InGaP-based power amplifiers for wireless handsets, wireless LAN, broadband gain blocks, and high-speed fiber optic products have been successfully developed and marketed. For future generations of these products, it is important to reduce the die size and cost as well as to provide additional functionality with improved circuit performance. The integration of bipolar (HBT) and field effect transistors (FET or HEMT) on the same chip offers a unique way to achieve these goals. While the combination of bipolar and field effect devices in an integrated circuit is well known in the silicon world (BiCMOS), there has been no viable way to realize this concept in GaAs-based technologies for large volume commercial applications. Several methods of integrating AlGaAs/GaAs HBT with field effect devices have been discussed in the literature. In one approach described in Ho et al., “A GaAs BiFET LSI technology”, GaAs 1C Sym. Tech. Dig., 1994, p. 47, and D. Cheskis et al., “Co-integration of GaAlAs/GaAs HBT's and GaAs FET's with a simple manufacturable process”, IEDM Tech. Dig., 1992, p. 91, the HBT emitter cap layer is used as a FET channel. This approach had two major drawbacks. First, the emitter resistance of the HBT is high and second, the parasitic effect of the base layer degrades FET performance and limits its applications. Another approach is to grow HBT and HEMT structures by selective MBE growth. (See Streit, et al., “Monolithik HEMT-HBT integration by selective MBE”, IEEE Trans. Electron Devices, vol. 42, 1995, p. 618 and Streit, et al., “35 GHz HEMT amplifiers fabricated using integration HEMT-HBT material grown by selective MBE”, IEEE Microwave Guided Wave Lett., vol. 4, 1994, p. 361.) The problem with this approach is the requirement of epi-growth interruption, wafer processing and epi re-growth. These steps render this approach un-manufaurable (i.e. high cost) with poor epi quality control. It has also been shown that AlGaAs/GaAs HBT may be grown on top of the HEMT in a single growth run. (See K, Itakura. Y. Shimamolo, T. Ueda, S. Katsu, D. Ueda, “A GaAs Bi-FET technology for large scale integration”, IEDM Tech. Dig., 1989, p. 389.) In this approach the FET is merged into the collector of the HBT through a single epitaxial growth. Several attempts have been also made to integrate InGaP/GaAs HBT with MESFET and HEMT. (See J. H. Tsai, “Characteristics of InGaP/GaAs co-integrated d-doped heterojunction bipolar transistor and doped-channel field effect transistor,” Solid State Electronics, vol. 46., 2002, p. 45 and Yang et al., “Integration of GalnP/GaAs heterojunction bipolar transistors and high electron mobility transistors”, IEEE Electron Device Lett., vol. 17, no, 7, July 1996, p. 363. In these approaches the channel of the field effect devices used an InGaP layer with low mobility and saturation velocity which results in high linear resistance and poor high frequency performance. These devices also show threshold voltages lower than −2 Volts. These characteristics, however, make them largely unsuitable for commercial applications. There is therefore a need for methods and epitaxial structures for fabricating integrated pairs of GaAs-based HBT and FET devices that are suitable for commercial applications. SUMMARY OF INVENTION One aspect of the present invention is a structure comprising a first epitaxial layer on top of the substrate; a second layer structure on top of the first epitaxial layer, and a third epitaxial layer on top of the second epitaxial layer. In one embodiment, the first epitaxial layer forms a portion of a field effect transistor. The third epitaxial layer forms a portion of a bipolar transistor. The second epitaxial layer is shared by the bipolar and the field effect transistors. Another aspect of the present invention comprises a method of fabricating integrated bipolar transistor and field effect transistors on the same substrate. In one embodiment, the method comprises the steps of: providing the three-layer structure comprising a first, second, and third epitaxial layer; fabricating the bipolar transistor from the first epitaxial layer of the structure; isolating the second and third epitaxial layers of the structure; and optimizing the field effect transistor and the bipolar transistor independently. Yet another aspect of the present invention comprises an integrated pair of bipolar and field effect transistors. In one embodiment, the bipolar and field effect transistors share a contact layer. The contact layer serves as both the cap layer for the field effect transistor and the subcollector layer for the bipolar transistor. Yet another aspect of the present invention comprises a method of fabricating an epitaxial structure for fabricating an integrated pair of GaAs-based HBT and FET. In one embodiment, the method comprises the steps of: growing a first set of epitaxial layers for fabricating the FET on a semi-insulating GaAs substrate; fabricating a highly doped thick GaAs layer serving as the cap layer for the FET and the subcollector layer for the HBT; and producing a second set of epitaxial layers for fabricating the HBT. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 illustrates a structure for fabricating an integrated FET and HBT pair in one embodiment of this invention. FIGS. 2a-2b demonstrate the results of a sensitivity study of the relationships between subcollector thickness and the power-added efficiency (PAE), cut-off frequency (ft) and maximum oscillating frequency (fmax) characteristics of the HBT. FIG. 3 describes the characteristics of each layer in the epitaxial structure in one embodiment of this invention. FIG. 4 shows the process flow used in the fabrication of HBT/FETs according to one embodiment of this invention. FIG. 5 shows a cross-section view of the integrated pair of HBT and FET formed during the process of FIG. 4. FIGS. 6-7 summarize the characteristics of the HBT and MESFET fabricated according to one embodiment of this invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 1 illustrates the formation of the structure for fabricating an integrated FET and HBT pair in one embodiment of this invention. Substrate 101 is first provided and may be a semi-insulating GaAs wafer substrate, or any suitable substrate for fabricating the integrated HBT and FET pair. The GaAs substrate 101 may be fabricated using well-known crystal-growth technologies such as the Czochralski technique or the Bridgman technique. Detailed descriptions of these techniques can be found, for example, at page 343-349 of S. M. Sze, “Semiconductor Devices: Physics and Technology”, 2nd Ed., John Wiley & Sons, Inc. 2002. After providing the substrate 101, a first epitaxial structure 102 may be grown on top of the substrate 101. The epitaxial structure 102 may comprise one or more epitaxial layers. The epitaxial structure 102 (and other epitaxial structures grown on top of it) may be fabricated using well-known technologies such as chemical vapor deposition (CVD), Metalorganic CVD (MOCVD), or molecular bean epitaxy (MBE). Detailed descriptions of these technologies can be found, for example, at page 356-361 of S. M. Sze, “Semiconductor Devices: Physics and Technology”, 2nd Ed., John Wiley & Sons, Inc. 2002. The composition and thickness of each epitaxial layer in the epitaxial structure 102 may depend on the application and the type of FET that is being fabricated. In FIG. 1, the epitaxial structure 102 comprises a first set of epitaxial layers 121 and a second set of epitaxial layers 122. The first set of epitaxial layers 121 may be used to form a low leakage buffer layer, which can help reduce the substrate leak current and output conductance, thereby improving the efficiency of the FET. The low leakage buffer layer may (but not necessarily) further comprise one or more undoped GaAs or AlGaAs layers. The thickness of each layer and the aluminum mole fraction of each AlGaAs layer may be chosen to optimize the performance of the FET or the HBT. The low leakage buffer layer may comprise an undoped GaAs layer approximately 75 nm (1 nm=10−9 meter) thick and an undoped AlGaAs layer with approximately 250 nm thick. The undoped AlGaAs may comprise approximately 25% Al. The second set of epitaxial layers 122 may be used to form the epitaxial structure for the FET. The layer structure and the thickness of each epitaxial layer in the epitaxial layers 122 may depend on the application and the type of FET that is being fabricated. In FIG. 1, the epitaxial layers 122 form the epitaxial structure for a MESFET. The set of epitaxial layers 122 may comprise an approximately 50 nm thick undoped GaAs spacer layer and a doped GaAs channel layer of about 120 nm thick. The spacer layer can help carrier confinement and provide spatial separation between the active channel and the AlGaAs/GaAs heterojunction in the buffer layer 121. The doping type and concentration of the channel layer depends on the application. For example, the channel layer may be doped with n-type Silicon with a doping concentration of approximately 3.2×1017 cm−3. Moreover, a thin (about 20 nm) highly doped InGap etch stop layer 103 may be grown on top of the GaAs channel layer for recess etch reproducibility. As known by skilled people in the field, other layered structures may be fabricated for other types of MESFET and are intended to be encompassed by this invention. In other embodiments, the epitaxial layers 122 form the epitaxial structure for a pHEMT. The set of epitaxial layers 122 may further comprise a lower GaAs barrier layer, an InGaAs channel layer and an AlGaAs Schottky barrier layer. Double delta doping may be used between these layers to further improve the performance. A thin (about 20 nm) highly doped InGap etch stop layer may be grown on top of the AlGaAs Schottky layer for recess etch reproducibility. Depending on the application, the pHEMT epitaxial structure may be formed by different layer structure and doping methods known to skilled people in the field. After completion of the growth of the first epitaxial structure 102, a second epitaxial structure is then grown on top of the first epitaxial structure 102. In FIG. 1, the second epitaxial layer further comprises a highly doped GaAs contact layer 104 that is grown on top of the etch-stop layer 103. The contact layer 104 may be shared by the FET and the HBT. The contact layer 104 serves as the cap layer for the FET and the subcollector layer for the HBT. The requirements for the contact layer may include low resistivity for both the FET and the HBT. The doping concentration in this layer can be the maximum doping concentration achievable from the growth technology. In an illustrative example, an n-type Silicon doping with a doping concentration of greater then 4.0×1018 cm−3 is used for the contact layer 104. The thickness of the contact layer 104 depends on the application. The thickness of the contact layer may be chosen based on the following trade-off. The thickness of the subcollector layer may be increased so that the HBT does not have excessive collector resistance and degraded performance. On the other hand, a thinner cap may be preferred to minimize surface topology and simplify the FET fabrication process. More specifically, in the embodiment shown in FIG. 1, the thickness of the contact layer 104 is selected based on a sensitivity study of the relationships between HBT characteristics and subcollector thickness. Such a study may be performed using, for example, a physical device simulator, such as the ATLAS device simulation software provided by SILVACO International, headquartered in Santa Clara, Calif. FIGS. 2a-2b illustrate the results of a sensitivity study of the relationships between subcollector thickness and the power-added efficiency (PAE), cut-off frequency (ft) and maximum oscillating frequency (fmax) characteristics of the HBT. Specifically, curve 220 in FIG. 2a shows the relationship between subcollector thickness and the power-added efficiency (PAE). Curve 230 of FIG. 2b shows the relationship between subcollector thickness and the cut-off frequency (ft). Curve 240 of FIG. 2b shows the relationship between subcollector thickness and the maximum oscillating frequency (fmax). A thickness of 350 nm may be selected for the contact layer 104, based in part on the result of this study. The rest of the HBT layers may be fabricated on top of the contact layer 104 using existing HBT fabrication Technologies. In the embodiment shown in FIG. 1, for example, an n-type GaAs collector layer 105 of thickness from about 800 nm to about 1200 nm is grown on top of the contact layer 104. A p-type GaAs base layer 106 and an n-type InGaP emitter 107 layer are then grown on the collector layer 105 followed by a highly doped InGaAs contact layer 108. The HBT structure described above is a generic form. The thickness and doping characteristics of the HBT structure may be optimized further for specific applications. For example, the collector layer 105 may comprise two lightly doped GaAs layers. The base layer 106 may be about 110 nm thick and doped with carbon at a concentration of about 4.0×1019 cm−3. The emitter layer 107 may be about 50 nm thick and doped with silicon with a doping concentration of about 3.0×1017 cm−3. The contact layer 108 may be about 40 nm thick and doped with Tellurium (Te) with a doping concentration of 1.0×1019 cm−3. A thin (about 20 nm) InGaP etch stop layer 124 may be grown between the contact layer 104 and the collector layer 105. The epitaxial layers 102-108 described above can be fabricated in a single MOCVD or MBE growth run. FIG. 3 summaries the characteristics of each layer in the epitaxial structure in the embodiment shown in FIG. 1. The fabricated epitaxial structure may then be processed to fabricate the integrated HBT and FET pair. FIG. 4 shows the process flow used in the fabrication of HBT/FETs according to one embodiment of this invention. FIG. 5 illustrates a cross-section view of the integrated pair of HBT and FET formed during the process shown in FIG. 4. Epitaxial layers 102-108 are first grown on a wafer substrate 101 in step 400. In step 410, the emitter contact 110 is deposited on the wafer after establishing alignment keys on the wafer. In this step, the emitter area 111 is first defined using photoresist. Next, the emitter metal film 112 is deposited over the photoresist. The emitter film 112 may be formed by metals such as Ti, Pt, Pl, Au, Al, or Cu or metal compounds or alloys formed using these metals. The emitter film 112 may be deposited using well-known physical-vapor deposition (PVD) methods such as e-beam evaporation, plasma spray deposition, or sputtering. In the embodiment shown in FIG. 4, a Ti/Pt/Au or Pt/Ti/Pt/Au emitter film 112 is deposited on the photoresist by e-beam evaporation. Those portions of emitter film on the photoresist but not on the emitter area are then removed using the well-known liftoff technique. In step 420, the emitter of the HBT is formed by etching the emitter layer 107 and the contact layer 108. In the embodiment shown in FIG. 4, the emitter layer 107 and the contact layer 108 are placed in a phosphoric acid-based chemistry that is selective to InGaP to etch the emitter after depositing the emitter contact. In step 430, the base of the HBT is formed. In this step, the base area 114 is first defined using photoresist. Base contact 115 is then deposited on the photoresist using similar PVD and liftoff technologies as described above. In FIG. 4, an InGaP etch through the photoresist openings may be performed prior to base metal evaporation to define the InGaP ledge and expose the base layer 106 for base contact deposition. The InGaP layer 107 may be etched in a hydrochloric acid based chemistry which is selective to GaAs. After depositing the base contact 115, the base layer 106 is then etched to produce the base of the HBT. In the embodiment shown in FIG. 4, the base layer 106 is etched in a phosphoric acid-based chemistry that is selective to GaAs. In step 440, the collector of the FET is formed. In this step, the collector area 117 is first formed using photoresist. Collect contacts 118 are then deposited on the photoresist using similar PVD and liftoff technologies as described above. In FIG. 4, the collector layer 105 is first etched in a phosphoric acid based chemistry for the GaAs layer 105 and then etched in a hydrochloric acid based chemistry for the InGaP layer 124. In step 450, an isolation barrier 130 is implanted after the collector etch to isolate the HBT and the FET so that the HBT and the FET can be optimized independently. The subcollector layer is exposed except underneath the HBT base area. A passivation layer may be deposited on the wafer using well-known chemical vapor deposition (CVD) methods to protect the HBT device during subsequent process steps. A nitride passivation layer is deposited on the wafer using plasma-enhanced CVD (PECVD). Besides isolating the HBT and the FET, the isolation barrier 130 may also be used to isolate the HBT/FET pair from other devices such as diodes or resistors that are fabricated on the same substrate. The isolation barrier 130 may be implanted using well-known ion or trench implantation techniques. In FIG. 4, the isolation barrier 130 may be formed using a He+ ion implantation, wherein the isolation pattern is defined using a thick photoresist mask. In step 460, the source contact 132 and the drain contact 134 of the FET are deposited on the wafer using well-known metal evaporation and liftoff technologies. The contacts 132 and 134 are made from AuGeNi and these contacts are deposited by evaporation of AuGeNi and the corresponding liftoff technique. In an alternative embodiment, the Collector contacts 118 are deposited in this step instead of in step 440. In step 470, channel recess etch for the FET is performed. In this step, the FET recesses area 136 is first defined and the cap layer 104 is then etched. The cap layer 104 is etched in a phosphoric acid based chemistry for GaAs and the InGaP layer 103 is then etched in a Hydrochloric acid based chemistry for InGaP. The InGap etch stop layer 103 ensures a uniform and reproducible etch. In step 480, the FET gate 138 is formed. The FET gate formation process may depend on the specific device structure and application requirements. For example, for driver or amplifier applications, a low resistance gate may be required and for such applications a T-gate process block may be introduced at this step. For applications such as dc/rf switch, an evaporated gate may be sufficient. The fabrication of T-gates and evaporated gates are well-known in the art. In the embodiment shown in FIG. 4, an evaporation gate is fabricated as follows. First, the FET gate is defined by a photoresist mask. The photoresist mask may be optimized for thickness to provide adequate coverage over the topology and for the minimum required gate length. Next, gate metal of TiPtAu is deposited by e-beam evaporation and lift-off technique. After completion of the FET gate 138, a nitride film may be deposited to passivate the FET. The integrated HBT/FET pair fabricated may be further processed for passive component and interconnect fabrication. These steps can be performed using conventional IC fabrication techniques. Devices fabricated using the integrated HBT/FET Technology described above show performance equivalent to similar non-integrated “stand-alone” HBT or FET transistors. This makes it possible to use them in commercial applications with no penalty in performance but with significant improvement in integration opportunities. The characteristics of the HBT and FET fabricated based on the epitaxial structure shown in FIG. 3 are summarized in FIG. 6 and FIG. 7. Since bipolar and field effect transistors are de-coupled by the isolation 130, the epitaxial layers that form these devices can be optimized independently to achieve any given device characteristics. The method of integrating bipolar and field effect transistors described in this invention is not limited to GaAs-based devices alone. It can be used equally effectively on any set of bipolar and field effect transistors that can be fabricated using epitaxial active layers on the same substrate. Examples of bipolar and field effect transistor pairs may include, but not limited to, InP-based HBT and InP FET/pHEMT, GaN based HBT and GaN pHEMT/FET. Moreover, the integrated HBT and FET devices may be fabricated with alternative process flows, etch chemistries and ohmic contact metalizations. As an illustrative example, citric acid and sulfuric acid based chemistries may be used to selectively etch or dry etch GaAs/AlGaAs layers on InGaP layers. In another illustrative example, the FET recess and gate layers may be formed right after the formation of the HBT base. The field effect transistor can be optimized for particular applications and can be either enhancement mode (E-mode) or depletion mode (D-mode) or it can be designed to provide both E and D mode FETs. E/D FETs are especially desirable for the implementation of digital logic functions. The Field Effect Transistor can be realized with alternative epitaxial layer structures known in the industry. Examples of alternative epitaxial layers include but not limited to pHEMT with InGaP as the Schottky layer, pHEMT with AlAs etch stop layer, double recessed pHEMT and MESFET, HIGFET and Hi/Lo MESFET. Based on the above description, it may occur to any person skilled in the art that passive components such as N-resistor, NiCr resistor, MIM capacitor, spiral inductors, backside via and global and local interconnects may also be fabricated using processes similar to the processes described above. While the above invention has been described with reference to certain preferred embodiments, the scope of the present invention is not limited to these embodiments. One skilled in the art may find variations of these embodiments which, nevertheless, fall within the spirit of the present invention, whose scope is defined by the claims set forth below. | <SOH> BACKGROUND OF INVENTION <EOH>InGaP/GaAs HBT Technology is very attractive for use in many commercial applications for its excellent reliability and thermal stability. The first generation of InGaP-based power amplifiers for wireless handsets, wireless LAN, broadband gain blocks, and high-speed fiber optic products have been successfully developed and marketed. For future generations of these products, it is important to reduce the die size and cost as well as to provide additional functionality with improved circuit performance. The integration of bipolar (HBT) and field effect transistors (FET or HEMT) on the same chip offers a unique way to achieve these goals. While the combination of bipolar and field effect devices in an integrated circuit is well known in the silicon world (BiCMOS), there has been no viable way to realize this concept in GaAs-based technologies for large volume commercial applications. Several methods of integrating AlGaAs/GaAs HBT with field effect devices have been discussed in the literature. In one approach described in Ho et al., “A GaAs BiFET LSI technology”, GaAs 1C Sym. Tech. Dig., 1994, p. 47, and D. Cheskis et al., “Co-integration of GaAlAs/GaAs HBT's and GaAs FET's with a simple manufacturable process”, IEDM Tech. Dig., 1992, p. 91, the HBT emitter cap layer is used as a FET channel. This approach had two major drawbacks. First, the emitter resistance of the HBT is high and second, the parasitic effect of the base layer degrades FET performance and limits its applications. Another approach is to grow HBT and HEMT structures by selective MBE growth. (See Streit, et al., “Monolithik HEMT-HBT integration by selective MBE”, IEEE Trans. Electron Devices, vol. 42, 1995, p. 618 and Streit, et al., “35 GHz HEMT amplifiers fabricated using integration HEMT-HBT material grown by selective MBE”, IEEE Microwave Guided Wave Lett., vol. 4, 1994, p. 361.) The problem with this approach is the requirement of epi-growth interruption, wafer processing and epi re-growth. These steps render this approach un-manufaurable (i.e. high cost) with poor epi quality control. It has also been shown that AlGaAs/GaAs HBT may be grown on top of the HEMT in a single growth run. (See K, Itakura. Y. Shimamolo, T. Ueda, S. Katsu, D. Ueda, “A GaAs Bi-FET technology for large scale integration”, IEDM Tech. Dig., 1989, p. 389.) In this approach the FET is merged into the collector of the HBT through a single epitaxial growth. Several attempts have been also made to integrate InGaP/GaAs HBT with MESFET and HEMT. (See J. H. Tsai, “Characteristics of InGaP/GaAs co-integrated d-doped heterojunction bipolar transistor and doped-channel field effect transistor,” Solid State Electronics, vol. 46., 2002, p. 45 and Yang et al., “Integration of GalnP/GaAs heterojunction bipolar transistors and high electron mobility transistors”, IEEE Electron Device Lett., vol. 17, no, 7, July 1996, p. 363. In these approaches the channel of the field effect devices used an InGaP layer with low mobility and saturation velocity which results in high linear resistance and poor high frequency performance. These devices also show threshold voltages lower than −2 Volts. These characteristics, however, make them largely unsuitable for commercial applications. There is therefore a need for methods and epitaxial structures for fabricating integrated pairs of GaAs-based HBT and FET devices that are suitable for commercial applications. | <SOH> SUMMARY OF INVENTION <EOH>One aspect of the present invention is a structure comprising a first epitaxial layer on top of the substrate; a second layer structure on top of the first epitaxial layer, and a third epitaxial layer on top of the second epitaxial layer. In one embodiment, the first epitaxial layer forms a portion of a field effect transistor. The third epitaxial layer forms a portion of a bipolar transistor. The second epitaxial layer is shared by the bipolar and the field effect transistors. Another aspect of the present invention comprises a method of fabricating integrated bipolar transistor and field effect transistors on the same substrate. In one embodiment, the method comprises the steps of: providing the three-layer structure comprising a first, second, and third epitaxial layer; fabricating the bipolar transistor from the first epitaxial layer of the structure; isolating the second and third epitaxial layers of the structure; and optimizing the field effect transistor and the bipolar transistor independently. Yet another aspect of the present invention comprises an integrated pair of bipolar and field effect transistors. In one embodiment, the bipolar and field effect transistors share a contact layer. The contact layer serves as both the cap layer for the field effect transistor and the subcollector layer for the bipolar transistor. Yet another aspect of the present invention comprises a method of fabricating an epitaxial structure for fabricating an integrated pair of GaAs-based HBT and FET. In one embodiment, the method comprises the steps of: growing a first set of epitaxial layers for fabricating the FET on a semi-insulating GaAs substrate; fabricating a highly doped thick GaAs layer serving as the cap layer for the FET and the subcollector layer for the HBT; and producing a second set of epitaxial layers for fabricating the HBT. | 20040220 | 20060321 | 20050825 | 74724.0 | 1 | HUYNH, ANDY | STRUCTURES AND METHODS FOR FABRICATING VERTICALLY INTEGRATED HBT-FET DEVICE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,784,022 | ACCEPTED | Swivel mount for a spray head | A swivel mount for a spray head configured to be at least partially recessed within a mounting surface of a wall. | 1. A swivel mount for a spray head comprising: a holder including an opening concentrically disposed about a longitudinal holder axis; a first retainer including an axially extending tubular portion and a retaining member extending outwardly from the tubular portion, the tubular portion being received within the opening of the holder; a body including an outer surface having a semi-spherical portion and an opening concentrically receiving the tubular portion of the first retainer, the body defining a longitudinal body axis; a seal positioned in sealing engagement with the semi-spherical portion of the body; and wherein the body is supported for pivoting movement relative to the holder such that the longitudinal body axis may be angularly offset from the longitudinal holder axis. 2. The swivel mount of claim 1, further comprising a second retainer supported by the tubular portion of the first retainer, wherein axial movement of the body relative to the holder is restrained by the first retainer and the second retainer. 3. The swivel mount of claim 1, further comprising a nipple including a socket concentrically receiving the holder and a passageway in fluid communication with the tubular portion of the first retainer. 4. The swivel mount of claim 3, further comprising an annular seal positioned intermediate the nipple and the holder, wherein the nipple includes an annular seat configured to support the seal. 5. The swivel mount of claim 3, further comprising a bonnet concentrically receiving and coupled to the socket of the nipple, the bonnet including a retaining ring and the holder including an annular lip, wherein the annular lip of the holder is coupled intermediate the socket of the nipple and the retaining ring of the bonnet. 6. The swivel mount of claim 5, further comprising: a sleeve concentrically receiving and coupled to the bonnet, the sleeve including a generally cylindrical body, a plurality of supports extending upwardly from the body, and a plurality of locking tabs extending outwardly from the body; and a shroud including an upper portion supported by the plurality of supports of the sleeve and a lower portion including an annular lip operably coupled to the plurality of locking tabs of the sleeve. 7. The swivel mount of claim 6, further comprising an annular seal positioned intermediate the bonnet and the sleeve, wherein the bonnet includes an annular seat and a plurality of locating tabs extending upwardly adjacent to the seat, the seal being supported by the seat and positioned by the locating tabs. 8. The swivel mount of claim 6, further comprising a cover including an outer shield portion concentrically receiving the shroud and an inner support portion coupled to the body for movement relative to the shroud. 9. The swivel mount of claim 8, wherein the outer surface of the body includes a plurality of circumferentially spaced lips and the inner support portion of the cover includes a plurality of locking tabs positioned inwardly from the outer shield portion, the plurality of locking tabs being operably coupled with the plurality of lips of the body to axially secure the cover to the body. 10. The swivel mount of claim 9, wherein the outer surface of the body includes a plurality of circumferentially spaced channels and the inner support portion of the cover includes a plurality of locating tabs positioned inwardly from the outer shield portion and disposed intermediate the locking tabs, the locating tabs being operably coupled with the channels of the body to rotatably secure the cover to the body. 11. The swivel mount of claim 3, further comprising a flow regulator received within the passageway of the nipple and a retainer operably coupled with the nipple to retain the flow regulator within the nipple. 12. The swivel mount of claim 3, further comprising a hexagonal opening concentrically received within the passageway of the nipple and configured to receive a tool. 13. The swivel mount of claim 1, wherein the body is configured to receive a fluidic cartridge assembly in fluid communication with the tubular portion of the first retainer. 14. A fluid delivery assembly configured to be at least partially recessed within a mounting surface of a wall, the fluid delivery assembly comprising: a fluid spray head; a body receiving and coupled to the fluid spray head, the body including a downwardly facing semi-spherical surface and an opening concentrically disposed about a longitudinal axis; a lower retainer including a disc having an upwardly facing semi-spherical surface positioned in spaced relation to the downwardly facing semi-spherical surface of the body; a generally bowl-shaped passageway defined intermediate the semi-spherical surface of the body and the semi-spherical surface of the lower retainer; and a holder received within the passageway, the body and the lower retainer being pivotable relative to the holder about axes orthogonal to the longitudinal axis, thereby orienting the fluid spray head in a desired position. 15. The fluid delivery assembly of claim 14, wherein the body is rotatable about the longitudinal axis. 16. The fluid delivery assembly of claim 14, further comprising an annular seal received intermediate the body and the holder. 17. The fluid delivery assembly of claim 14, wherein the lower retainer includes an axially extending tubular portion extending upwardly from the disc and received within the opening of the body. 18. The fluid delivery assembly of claim 14, further comprising an upper retainer coupled to the lower retainer such that the body and the holder are positioned axially intermediate the lower retainer and the upper retainer. 19. The fluid delivery assembly of claim 14, further comprising a nipple including a socket concentrically receiving the holder and a passageway in fluid communication with the fluid spray head through the opening of the body. 20. The fluid delivery assembly of claim 19, further comprising a bonnet concentrically receiving and coupled to the socket of the nipple, the bonnet including a retaining ring and the holder including an annular lip, wherein the annular lip of the holder is secured intermediate the socket of the nipple and the retaining ring of the bonnet. 21. The fluid delivery assembly of claim 20, further comprising: a sleeve coupled to the bonnet and including an annular body supporting a downwardly facing seat; and an annular seal positioned axially intermediate the seat and a mounting surface of a wall such that at least a portion of the body is recessed within the wall. 22. The fluid delivery assembly of claim 20, further comprising: a sleeve concentrically receiving and coupled to the bonnet, the sleeve including an annular body, a plurality of supports extending upwardly from the body, and a plurality of locking tabs extending outwardly from the body; and a shroud including an upper portion supported by the plurality of supports of the sleeve and a lower portion including an annular lip operably coupled to the plurality of locking tabs of the sleeve. 23. The fluid delivery assembly of claim 22, further comprising a cover including an outer shield portion concentrically receiving the shroud and an inner support portion coupled to the body for movement relative to the shroud. 24. A body spray assembly including: a holder including an upper semi-spherical surface, a lower semi-spherical surface, and an opening concentrically disposed about a longitudinal holder axis; a first retainer including an axially extending tubular portion and a disc extending outwardly from the tubular portion, the tubular portion being received within the opening of the holder and the disc including an upper semi-spherical surface conforming to the shape of the lower semi-spherical surface of the holder; a body including a downwardly facing semi-spherical surface conforming to the shape of the upper semi-spherical surface of the holder and an opening concentrically receiving the tubular portion of the first retainer, the body defining a longitudinal body axis; a fluid spray head received within and coupled to the body; an annular seal in sealing engagement with the holder and the body; a second retainer coupled to the tubular portion of the first retainer; the holder and the body being positioned axially intermediate the disc of the first retainer and the second retainer, and the first retainer and the body are pivotable about the holder such that the longitudinal body axis may be angularly offset from the longitudinal holder axis; a nipple including a socket concentrically receiving the holder and a passageway in fluid communication with the tubular portion of the first retainer; an annular seal positioned intermediate the nipple and the holder, wherein the nipple includes an annular seat to support the seal; a bonnet concentrically receiving and coupled to the socket of the nipple, the bonnet including a retaining ring and the holder including an annular lip, the annular lip of the holder being coupled intermediate the socket of the nipple and the retaining ring of the bonnet; a sleeve concentrically receiving and coupled to the bonnet, the sleeve including a generally cylindrical body, a plurality of supports extending upwardly from the body, and a plurality of locking tabs extending outwardly from the body; a shroud including an upper portion supported by the plurality of supports of the sleeve and a lower portion including an annular lip operably coupled to the plurality of locking tabs of the sleeve; an annular seal positioned intermediate the bonnet and the sleeve, wherein the bonnet includes an annular seat and a plurality of locating tabs extending upwardly adjacent to the seat, the seal being supported by the seat and positioned by the locating tabs; and a cover including an outer shield portion concentrically receiving the shroud and an inner support portion coupled to the body for movement relative to the shroud. | BACKGROUND AND SUMMARY OF THE INVENTION The present invention relates to a mounting assembly for supporting a spray head in a wall of a tub or shower installation. Conventional body spray assemblies typically use a simple rotatable ball spray head to provide the swivel required for directing fluid flow. Such conventional ball spray heads have necessitated that the entire body spray assembly be positioned on the visible side of the tub or shower installation. The present invention provides a swivel mount permitting at least a portion of the spray head assembly to be hidden behind the wall of the tub or shower installation. This provides not only a more pleasing installed appearance with less spray head assembly exposed within the tub or shower, but also permits the use of spray heads having increased axial lengths. For example, technically advanced spray heads often include complex arrangements of fluid chips and, as such, have a length greater than conventional ball spray heads. The swivel mount of the present invention permits recessed mounting, thereby facilitating the use of such elongated spray heads without causing undesired intrusion into the tub or shower installation. The swivel mount of the present invention includes a body coupled to the spray head and having an outer surface with a semi-spherical portion. A holder supports the body, and a seal is positioned intermediate the semi-spherical portion of the body and the holder. First and second retainers cooperate to compress the seal between the body and the holder with sufficient force to provide sealing engagement therebetween while permitting rotating and pivoting movement of the body relative to the holder. Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the presently perceived best mode of carrying out the invention. BRIEF DESCRIPTION OF THE DRAWINGS The detailed description of the drawings particularly refers to the accompanying figures in which: FIG. 1 is a perspective view of the spray head assembly of the present invention; FIG. 2 is an exploded perspective view of the spray head assembly of the present invention; FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 1, illustrating the spray head in a center position coaxially aligned with the longitudinal axis of the holder; FIG. 4 is a cross-sectional view similar to FIG. 3, illustrating the spray head pivoted to the left relative to its position in FIG. 3 and with details of the fluid chips of the spray head removed for clarity; FIG. 5 is a view similar to FIG. 3, illustrating the spray head pivoted to the right relative to its position in FIG. 3 and with details of the fluid chips of the spray head removed for clarity; FIG. 6 is a cross-sectional view similar to FIG. 3, with the details of the fluid chips of the spray head removed for clarity and showing the spray head assembly mounted in a recessed position relative to a wall of a tub or shower installation; FIG. 7 is a detailed exploded perspective view of the body, the annular seal, and the holder of the swivel mount of the present invention; FIG. 8 is a top plan view of the holder; FIG. 9 is a cross-sectional view of the holder taken along line 9-9 of FIG. 8; FIG. 10 is a detailed exploded perspective view of the first retainer and the second retainer of the swivel mount of the present invention; FIG. 11 is a side elevational view of the swivel mount of the present invention received within the nipple, but with a wedge-shaped portion thereof removed for illustrative purposes; FIG. 12 is a top plan view of the nipple; FIG. 13 is a cross-sectional view of the nipple taken along line 13-13 of FIG. 12; FIG. 14 is a top plan view of the sleeve; FIG. 15 is a cross-sectional view of the sleeve taken along line 15-15 of FIG. 14; FIG. 16 is a detailed exploded perspective view of the body and the cover of the present invention; and FIG. 17 is an exploded perspective view of an illustrative embodiment fluidic cartridge assembly. DETAILED DESCRIPTION OF THE DRAWINGS In accordance with the present invention as illustrated in FIGS. 1-3 and 6, a swivel mount assembly 10 is employed within a spray head assembly 12. The spray head assembly 12 may generally be mounted on a wall 11 of a tub or a shower (FIG. 6). It should be appreciated that a wide variety of spray heads 14, including spouts, body sprays, shower heads, or other like devices may be coupled to the swivel mount assembly 10 of the present invention depending upon the particular application. Referring now primarily to FIGS. 2, 3, and 7, the swivel mount assembly 10 includes a pivot body 16, a holder 18, an annular seal 19, a first retainer 20 and a second retainer 22. The pivot body 16 includes a substantially cylindrical upper portion 24 and a semi-spherical lower portion 26. The inner surface 28 of the pivot body 16 is configured to receive the spray head 14 through an upper opening 30. The inner surface 28 of the upper portion 24 illustratively includes a plurality of female threads 32 which threadably engage a plurality of male threads 34 formed within the spray head 14 (FIGS. 3 and 17). As described in greater detail below, an annular seal 36 is positioned intermediate the spray head 14 and the pivot body 16 in order to provide sealing engagement therebetween. The outer surface 38 of the lower portion 26 of pivot body 16 includes a downwardly facing semi-spherical portion 40, as shown in FIGS. 3, 7 and 11. The pivot body 16 defines a longitudinal body axis 42 and includes a passageway or opening 44 formed in the lower portion 26 and concentrically positioned about the longitudinal body axis 42. The opening 44 is illustratively defined by an integral tubular member 46 extending from above the inner surface 28 to below the outer surface 38 of the pivot body 16. The pivot body 16 may be formed from a thermoplastic material, although other suitable materials may be substituted therefor. With reference to FIGS. 3, 7-9, and 11, the holder 18 includes a body 52 having a side wall 54 extending upwardly and outwardly from an opening 56. The opening 56 is concentrically disposed about a longitudinal holder axis 58, which in FIG. 3 is shown in a coaxially aligned position with the longitudinal axis 42 of the pivot body 16. An annular ring or lip 60 extends outwardly from an upper end of the sidewall 54. An annular seat 62 is defined within an inner surface of the side wall 54 and is configured to receive the annular seal 19, illustratively a conventional O-ring formed of a resilient material, such as an elastomer. While an annular seal 19 is illustrated, it should be appreciated that other seals may be substituted therefor. A plurality of webs or ribs 66 extend inwardly from the inner surface 68 of the side wall 54 from above the seat 62. Each of the ribs 66 includes an arcuate inwardly facing surface 70 such that in combination, the ribs 66 define a semi-spherical surface substantially conforming to the shape of the semi-spherical outer surface 40 of the pivot body 16. The holder 18 may be formed from a thermoplastic material, although other suitable materials may be substituted therefor. Referring now to FIGS. 3, 10, and 11, the first or lower retainer 20 includes an axially extending tubular portion 80 defining a fluid passageway 82 which is cconcentrically disposed about the longitudinal body axis 42. A retaining member, illustratively an upwardly curved disc 84, extends outwardly from a lower end of the tubular portion 80. The disc 84 includes an upwardly facing semi-spherical or concave surface 86 and a downwardly extending semi-spherical or convex surface 88. The tubular portion 80 is concentrically received within the opening 44 of tubular member 46 of body 16. The first retainer 20 is illustratively formed of brass, although other suitable materials may be readily substituted therefor. A generally bowl-shaped passageway 90 is defined intermediate the semi-spherical portion 40 of outer surface 38 of pivot body 16 and the facing surface 86 of disc 84 of the first retainer 20. The side wall 54 of the holder 18 is received within the passageway 90. The pivot body 16 and the first retainer 20 are rotatable relative to the holder 18 about the longitudinal axis 42, and are pivotable relative to the holder 18 about axes orthogonal to the longitudinal axis 42. As such, the spray head 14 within the body 16 has three degrees of rotational freedom and may be oriented as desired by the user. As shown in FIGS. 4 and 5, the first retainer 20 and the pivot body 16 supporting the spray head 14 are supported for pivoting movement relative to the holder 18 such that the longitudinal body axis 42 may be angularly offset from the longitudinal holder axis 58. The cylindrical surface 92 defining the opening 56 of the holder 18 defines a stop to limit pivoting movement of the pivot body 16. More particularly, engagement between the outer surface 94 of the tubular member 46 of pivot body 16 and the surface 92 of the holder 18 stops further pivoting movement in a given direction (FIGS. 4 and 5). The second retainer 22 is coupled proximate an upper end of the tubular portion 80 of the first retainer 20. More particularly, the second retainer 22 illustratively comprises a conventional spring clip received within a groove 93 formed proximate the upper end of the tubular portion 80. It should be appreciated that other suitable retainers could be substituted for the spring clip. For example, the upper end of the tubular portion 80 could support a plurality of threads which engage a conventional nut or a plurality of threads integrally formed within the pivot body 16. The first retainer 20 and the second retainer 22 axially clamp or squeeze the seal 19 between the pivot body 16 and the holder 18. The distance between the disc 84 of the first retainer 20 and the second retainer 22 is dimensioned so as to provide sufficient compressive force on the seal 19 for providing sealing engagement between the holder 18 and the pivot body 16 while still permitting rotating and pivoting movement of the body 16 relative to the holder 18. In other words, the first retainer 20 and the second retainer 22 cooperate to compress the seal 19 in order to provide a dynamic seal between the pivot body 16 and the holder 18. As shown in FIGS. 2-6, the swivel mount assembly 10 is mounted within a nipple assembly 100 including a nipple 102, a flow regulator 104, and a retaining clip 106. With reference to FIGS. 2, 3, 12, and 13, the nipple 102 includes a cylindrical upper socket 108 and a cylindrical lower connector 110. A fluid passageway 112 extends through the connector 110 to the socket 108. The fluid passageway 112 is in fluid communication with the passageway 82 of the first retainer 20 through a fluid chamber 128. The flow regulator 104 is of conventional design and is received within the passageway 112. The flow regulator 104 is retained in position by the retaining clip 106. As shown in FIGS. 2 and 3, the retaining clip 106 includes a plurality of wedge-shaped openings 113 in fluid communication with the flow regulator 104, and a plurality of outwardly extending retaining tabs 114. The retaining tabs 114 frictionally engage the inner surface 115 of the passageway 112 through an interference fit therewith. The lower end 116 of the fluid passageway 112 includes a plurality of female threads 118 configured to threadably engage a plurality of male threads 120 extending from a conventional water pipe 122 (FIG. 6). A hexagonal broach or opening 124 is concentrically received proximate an upper end 126 of the passageway 112 and is accessible through the socket 108 by conventional tools to assist in installation and removal of the nipple 102 to conventional pipe 122. The fluid chamber 128 includes a relief area 129 which provides clearance for pivoting movement of the first retainer 20 (FIGS. 4 and 5). The nipple 102 is illustratively formed from brass, although other suitable materials may be substituted therefor. With reference to FIGS. 2-6, a bonnet 130 concentrically receives and is coupled to the socket 108 of the nipple 102. The bonnet 130 illustratively includes a generally cylindrical body 131 having a plurality of inwardly facing or female threads 132 which threadably engage a plurality of outwardly facing or male threads 134 formed within the socket 108 of the nipple 102. The body 131 of the bonnet 130 includes a retaining ring 135 wherein the annular lip 60 of the holder 18 is coupled intermediate the retaining ring 135 of the bonnet 120 and the socket 108 of the nipple 102. The bonnet 130 is illustratively made of brass, although other suitable materials may be readily substituted therefor. An annular seal 136 is illustratively supported intermediate an annular seat 138 formed within the socket 108 of the nipple 102 and a seat 139 formed within the side wall 54 of the holder 18. The annular seal 136 illustratively comprises a conventional O-ring formed of a resilient material, such as an elastomer. A shroud assembly 140 includes a sleeve 142 and a shroud 144. The sleeve 142 concentrically receives and is coupled to the bonnet 130. As shown in FIGS. 14 and 15, the sleeve 142 illustratively includes a generally cylindrical body 145, a plurality of supports 146 extending upwardly from the body 145, and a plurality of locking tabs 148 extending outwardly and downwardly from the body 145. A plurality of inwardly facing or female threads 149 threadably engage a plurality of outwardly facing or male threads 150 supported on the bonnet 130. The sleeve 142 may be formed from a thermoplastic or other suitable material. An annular seal 152 is illustratively positioned intermediate the bonnet 130 and the sleeve 142. The seal 152 is illustratively formed of a resilient material, such as a polyethylene. The bonnet 130 includes an annular seat 154 and a plurality of locating tabs 156 extending upwardly adjacent to the seat, wherein the seal 152 is supported by the seat 154 and is positioned by the locating tabs 156. The shroud 144 concentrically receives the sleeve 142 and includes an upper portion 160 supported by the plurality of supports 146 of the sleeve 142. A plurality of downwardly extending tabs 162 are circumferentially positioned intermediate the supports 146 of the sleeve 142 and restrain rotational movement of the shroud 144. The shroud 144 further includes a lower portion 164 including an annular lip 166 operably coupled to the plurality of locking tabs 148 of the sleeve 142. The cooperation between the upper portion 160 and the supports 146, along with the cooperation between the lower portion 164 and the locking tabs 148 permits for a convenient and simple snap-fit installation of the shroud 144 to the sleeve 142. The shroud 144 is illustratively formed from brass, although other suitable materials may be substituted therefor. With reference to FIGS. 2, 3, and 16, a cover 170 concentrically receives the upper portion 162 of the shroud 160 and is coupled to the upper portion 24 of the pivot body 16. More particularly, the cover 170 includes an outer shield portion 172 concentrically receiving the upper portion 162 of the shroud 160. The cover 170 further includes an inner support portion 174 having a plurality of locking tabs 176 positioned inwardly from the outer shield portion 172. The plurality of locking tabs 176 are operably coupled with a plurality of lips 178 formed within the outer surface of the body 16 and are configured to cooperate therewith to axially secure the cover 170 to the body 16. The inner support portion 174 of the cover 170 further includes a plurality of locating tabs 180 positioned inwardly from the outer shield portion 172 and circumferentially offset from the locking tabs 176. The outer surface of the pivot body 16 includes a plurality of circumferentially spaced channels 182 configured to receive the locating tabs 180. Cooperation between the locating tabs 180 and the channels 182 assists in proper angular orientation between the cover 170 and the pivot body 16 while also rotatably securing the cover 170 to the pivot body 16. The cover 170 may be formed from a thermoplastic or other suitable material. Referring now to FIGS. 3 and 17, in the illustrative embodiment of the present invention, the spray head 14 includes a fluidic cartridge assembly 190 including a plurality of fluid chips 192 disposed within a channel 194 of a holder body 196. A base or diverter 198 is positioned below the fluid chips 192 and is in fluid communication with the passageway 82 of the first retainer 20. A top plate 200 is secured to the body 196 and is configured to secure the fluid chips 192 therewithin. A plurality of conventional fasteners, such as screws 202, may be utilized to secure the top plate 200 to the body 196. The annular seal 36, illustratively a conventional O-ring formed of a resilient material, is supported by a seat 204 formed within an outer surface of the body 196. As shown in FIGS. 2 and 3, a label 206 may be secured to an upper surface of the top plate 200 to provide an aesthetically pleasing appearance to the finished body spray assembly 12. The fluid chips 192 of the fluidic cartridge assembly 190 are designed to provide a desired fluid flow pattern. While the illustrative embodiment uses such fluid chip technology, as noted above, it should be appreciated that other types of spray heads may be readily substituted therefor. With reference to FIGS. 2 and 6, an annular mounting seal 208 is illustratively positioned intermediate the sleeve 142 and the mounting surface 210 of the wall 11. The mounting seal 208 illustratively comprises a polyethylene material, but other suitable materials may be readily substituted therefor. With further reference to FIGS. 2 and 3, assembly of the spray head assembly 12 begins with the formation of the swivel mount assembly 10. The swivel mount assembly 10 is assembled by initially placing the annular seal 19 into the seat 62 of the holder 18. Next, the pivot body 16 is inserted into the holder 18 such that the semi-spherical outer surface 40 of the pivot body 16 is facing the surfaces 70 of the ribs 66 of the holder 18. The body 16 and the holder 18 are retained in place by the fastener formed by the first retainer 20 and the second retainer 22. More particularly, the tubular portion 80 of the first retainer 20 is inserted through the openings 56 and 44 of the holder 18 and the pivot body 16, respectively. Next, the second retainer 22, illustratively a spring clip, is coupled to the upper end of the tubular portion 80 of the first retainer 20. As noted above, the first and second retainers 20 and 22 compress the seal 19 between the body 16 and the holder 18. At this point in the process, assembly of the swivel mount 10 is complete. The spray head 14, in the illustrative form of fluidic cartridge assembly 190, is assembled by inserting the fluid chips 192 and the diverter 198 within the channel 194 of the body 196. The top plate 200 is secured to the body 196 by screws 202 and covered by the label 206 which is adhesively affixed thereto. The annular seal 36 is then placed within seat 204. Next, the spray head 14 is inserted into the body 16 thereby forming a first installation assembly. The nipple assembly 100 defines a second installation assembly and is assembled by inserting the flow regulator 104 into the passageway of the nipple 102. Next, the retaining clip 106 is inserted within the passageway and forms an interference fit therein. The flow regulator 104 is thereby retained in place. The shroud assembly 140 defines a third installation assembly and is assembled by placing the shroud 144 over the sleeve 142. More particularly, the upper portion 160 intermediate the tabs 162 is supported by supports 146 of the sleeve 142, and the annular lip 166 of the shroud 144 couples to the locking tabs 148 of the sleeve 142. As such, the shroud 144 is easily “snap-fit” over the sleeve 142. During installation, the installer couples the nipple assembly 100 to the external pipe 122 by threading the female threads 118 of the nipple 102 onto the male threads 120 of the pipe 122. As needed, the installer may insert a tool, such as a wrench, into the hexagonal opening 124 of the nipple 102. Next, the first installation assembly, including the swivel mount assembly 10 and the spray head 14, is inserted into nipple assembly 100, or second installation assembly. More particularly, the seal 136 is placed in the seat 138 of the nipple socket 108, and the swivel mount assembly 10 is inserted into the nipple socket 108. The bonnet 130 is then coupled to the nipple 102 by threading the female threads 132 of the bonnet 130 onto the male threads 134 of the nipple 102, thereby securing the lip 60 of the holder 18 between the nipple 102 and the bonnet 130. Next, the seal 208 is placed against the mounting surface 240 of the wall 11, and the seal 152 is compressed between the sleeve 142 and the bonnet 130, by coupling the shroud assembly 140 or third installation assembly, to the bonnet 130. More particularly, the seal 152 is place on the seat 154 of the bonnet 130 and positioned by the tabs 156. Next, seal 208 is placed over the nipple 102. The female threads 149 of the sleeve 142 are then threaded onto the male threads 150 of the bonnet 130, thereby compressing the seals 152 and 208. Finally, the cover 170 is coupled to the pivot body 16 by aligning the locating tabs 180 within the channels 182 and aligning the locking tabs 176 with the lips 178. As detailed above, the locking tabs 176 couple with the lips 178 to secure the body 16 with the cover 170. Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the spirit and scope of the invention as described and defined in the following claims. | <SOH> BACKGROUND AND SUMMARY OF THE INVENTION <EOH>The present invention relates to a mounting assembly for supporting a spray head in a wall of a tub or shower installation. Conventional body spray assemblies typically use a simple rotatable ball spray head to provide the swivel required for directing fluid flow. Such conventional ball spray heads have necessitated that the entire body spray assembly be positioned on the visible side of the tub or shower installation. The present invention provides a swivel mount permitting at least a portion of the spray head assembly to be hidden behind the wall of the tub or shower installation. This provides not only a more pleasing installed appearance with less spray head assembly exposed within the tub or shower, but also permits the use of spray heads having increased axial lengths. For example, technically advanced spray heads often include complex arrangements of fluid chips and, as such, have a length greater than conventional ball spray heads. The swivel mount of the present invention permits recessed mounting, thereby facilitating the use of such elongated spray heads without causing undesired intrusion into the tub or shower installation. The swivel mount of the present invention includes a body coupled to the spray head and having an outer surface with a semi-spherical portion. A holder supports the body, and a seal is positioned intermediate the semi-spherical portion of the body and the holder. First and second retainers cooperate to compress the seal between the body and the holder with sufficient force to provide sealing engagement therebetween while permitting rotating and pivoting movement of the body relative to the holder. Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the presently perceived best mode of carrying out the invention. | <SOH> BACKGROUND AND SUMMARY OF THE INVENTION <EOH>The present invention relates to a mounting assembly for supporting a spray head in a wall of a tub or shower installation. Conventional body spray assemblies typically use a simple rotatable ball spray head to provide the swivel required for directing fluid flow. Such conventional ball spray heads have necessitated that the entire body spray assembly be positioned on the visible side of the tub or shower installation. The present invention provides a swivel mount permitting at least a portion of the spray head assembly to be hidden behind the wall of the tub or shower installation. This provides not only a more pleasing installed appearance with less spray head assembly exposed within the tub or shower, but also permits the use of spray heads having increased axial lengths. For example, technically advanced spray heads often include complex arrangements of fluid chips and, as such, have a length greater than conventional ball spray heads. The swivel mount of the present invention permits recessed mounting, thereby facilitating the use of such elongated spray heads without causing undesired intrusion into the tub or shower installation. The swivel mount of the present invention includes a body coupled to the spray head and having an outer surface with a semi-spherical portion. A holder supports the body, and a seal is positioned intermediate the semi-spherical portion of the body and the holder. First and second retainers cooperate to compress the seal between the body and the holder with sufficient force to provide sealing engagement therebetween while permitting rotating and pivoting movement of the body relative to the holder. Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the presently perceived best mode of carrying out the invention. | 20040220 | 20070724 | 20050825 | 57277.0 | 0 | GANEY, STEVEN J | SWIVEL MOUNT FOR A SPRAY HEAD | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,784,051 | ACCEPTED | Hollow plunger with guide integrated to bobbin assembly | An actuator suitable for use with a fluid flow control valve includes a frame, a bobbin, a coil and a plunger assembly. The frame is generally cylindrical and has a longitudinal axis. The bobbin, which is wound with the coil, includes a central cavity. The plunger assembly is received within the central cavity and includes a plunger portion and a rod portion. The plunger portion is formed of magnetic material. The rod portion may be snapped on the plunger portion to form the plunger assembly. The plunger assembly is configured to move within the cavity in response to an actuator control signal applied to the magnetic coil. Separating the plunger portion and the rod portion improves manufacturability as well as reduces the occurrence of rod damage. | 1. An actuator comprising: a frame having a longitudinal axis; a bobbin disposed in said frame, said bobbin having a central cavity; a coil wound on said bobbin for producing a magnetic field in at least said central cavity in response to a control signal applied thereto; and a plunger assembly movably disposed in said central cavity, said plunger assembly having a plunger portion secured to a rod portion, said plunger portion comprising magnetic material, wherein said rod portion comprises plastic material configured to allow a predetermined amount of elastic deformation, said rod portion being removably secured to said plunger portion by way of a snap fit onto a forward end of said plunger portion. 2. (canceled) 3. The actuator of claim 1 wherein said rod portion has a first end having a funnel shape, said forward end of said plunger portion having a conical shape corresponding to said funnel shape. 4. The actuator of claim 1 wherein said rod portion has a first through-bore, said plunger portion having a second through-bore, said first through-bore being in communication with said second through-bore when said rod portion is secured to said plunger portion. 5. The actuator of claim 4 wherein said first and second through-bores are configured for fluid flow. 6. The actuator of claim 5 wherein said first and second through-bores are configured for fluid damping and compensation of hydraulic forces in said actuator. 7. The actuator of claim 1 wherein said cavity includes a closed end, said bobbin further including a guide axially extending from said closed end into said cavity, said guide being configured to align said plunger assembly within said cavity. 8. The actuator of claim 7 wherein said plunger portion includes a back end axially opposite said forward end, said second through-bore at said back end being configured to receive said guide therein. 9. The actuator of claim 7 wherein said guide includes an axially extending post, said post having a pair of guiding discs extending radially outwardly from said post, one of said pair of discs being axially offset from the other one of said pair of discs, each of said pair of discs having a diameter corresponding to a diameter of said second through-bore of said plunger portion at said back end. 10. The actuator of claim 7 wherein said guide further includes a stop feature configured to minimize contact of said back end of said plunger portion with said closed end of said cavity. 11. The actuator of claim 1 wherein said bobbin includes an annular secondary plate formed of magnetic material insert molded therein, said bobbin being configured to provide an annular isolation layer between an inner diameter of said secondary plate and said plunger portion in said cavity. 12. An actuator for controlling a valve, said actuator comprising: a frame having a longitudinal axis; a bobbin disposed in said frame, said bobbin having a central cavity, said bobbin further including an outer winding surface; a coil wound on said winding surface of said bobbin for producing a magnetic field in at least said central cavity in response to a control signal applied thereto; and a plunger assembly movably disposed in said central cavity, said plunger assembly having a plunger portion secured to a rod portion, said plunger portion comprising magnetic material, said rod portion comprising plastic material configured to allow a predetermined amount of elastic deformation, said rod portion being removably secured to said plunger portion by way of a snap fit onto a forward end of said plunger portion, said rod portion having a first through-bore, said plunger portion having a second through-bore, said first through-bore being in communication with said second through-bore when said rod portion is secured to said plunger portion, said first and second through-bores being configured for fluid flow, said cavity including a closed end, said bobbin further including a guide axially extending from said closed end into said cavity, said guide being configured to align said plunger assembly within said cavity, said plunger portion including a back end axially opposite said forward end, said second through-bore at said back end being configured to receive said guide therein, said guide including an axially extending post, said post having a pair of guiding discs extending radially outwardly from said post, one of said pair of discs being axially offset from the other one of said pair of discs, each of said pair of discs having a disc diameter corresponding to a plunger-bore diameter of said second through-bore of said plunger portion at said back end. 13. The actuator of claim 12 wherein said first through-bore being in registry with said second through-bore. 14. The actuator of claim 13 wherein said rod portion has a first end having a funnel shape, said forward end of said plunger portion having a conical shape corresponding to said funnel shape. 15. The actuator of claim 14 wherein said first and second through-bores are configured for fluid damping and compensation of hydraulic forces in said actuator. 16. The actuator of claim 15 wherein said guide further includes a stop feature configured to minimize contact of said back end of said plunger portion with said closed end of said cavity. 17. The actuator of claim 16 wherein said bobbin includes an annular secondary plate formed of magnetic material insert molded therein, said bobbin being configured to provide an annular isolation layer between an inner diameter of said secondary plate and said plunger portion in said cavity. | TECHNICAL FIELD The present invention relates to an actuator, and more particularly, to an actuator having a hollow plunger positioned in a housing used for fluid flow control. BACKGROUND OF THE INVENTION Solenoid actuators are well known in fluid flow control, where an orifice or aperture in a fluid flow path is to be opened or closed by means of a closure member such as a plunger, rod, spool or the like. Such actuators commonly comprise a magnetic circuit including a flux-generating coil, and a plunger formed of magnetic material moving under the influence of a magnetic field that changes in response to varying current flow through the coil. The plunger may be mechanically coupled to the closure member, which opens or closes the aperture or orifice in the fluid flow path as the plunger moves in accordance with changes in the magnetic field. In a particular arrangement, it is known to use a solenoid actuator as part of a camshaft control system (i.e., cam phaser position control). As known, the camshaft of an internal combustion engine may be employed to control the opening/closing of engine valves (e.g., intake, exhaust). As further background, then, cam phasing may be understood as the shifting of valve events in a crank angle (or cam angle) domain. Typically, a mechanical device is attached to the end of the camshaft for such purpose (“cam phaser”). The cam phaser may include an oil-actuated piston coupled to a gear train, a spool control valve for controlling the flow of oil to the piston, and an actuator for controlling the spool control valve. The actuator is driven by a pulse width modulated (PWM) signal from an engine control unit. The actuator includes a forward rod that extends into the spool valve and acts as a closure member, opening/closing various ports. As the duty cycle of the PWM signal is varied, the rod is caused to move to a controlled depth in the spool valve, controlling the flow of oil, for example, to one side or the other of the above-mentioned piston, thereby in-effect actuating the gear train in a controlled fashion. The gear train moves the camshaft. FIG. 1 is a cross-sectional, side view showing a conventional solenoid actuator 10 used in connection with the above-described cam phaser. Actuator 10 includes a solid plunger 12 having a rod portion 13, a cup 14, a magnetic coil 16, a secondary plate 18, a washer 20 and a bobbin 22. Plunger 12 is a solid piece of ferromagnetic material, conical in shape at the front or at the tip, and is typically machined from a steel bar. Plunger 12 is also shown to include a plurality of axially extending flutes 24 formed in the outer surface of plunger 12. Flutes 24 interact with the oil for damping and hydraulic force compensation. FIG. 1 is taken in section through a pair of such flutes; thus, flutes 24 shown in FIG. 1 are shown without cross-hatching. Cup 14 acts as a guide for plunger 12 and additionally isolates plunger 12 from secondary plate 18. Cup 14 is a deep drawn component that is supported inside bobbin 22 to avoid fractures of the cup itself. Washer 20 is used as a magnetic brake between plunger 12 and primary plate 18. In operation, plunger 12 moves within cup 14 in accordance with the magnetic force induced by the magnetic flux produced by coil 16. Rod portion 13 is configured to extend into a spool control valve (not shown) for controlling oil flow, as described above. However, there are several shortcomings. First, the rod portion 13 of the integral plunger/rod 12 may become bent during the manufacturing operation (e.g., machining) or shipping, which may result in an inoperable actuator when assembled and tested. Second, the flutes, among other features, are relatively complex to manufacture. Third, the inside diameter surface of cup 14 (i.e., the guide) and the outside diameter surface of plunger 12 (i.e., the guided part) are coextensive over a relatively large area, thus increasing drag or friction therebetween. Fourth, a hydraulic lock (i.e., sticking) condition may occur when the rear of plunger 12 contacts the closed end of cup 14. There is therefore a need for an improved actuator that minimizes or eliminates one or more of the shortcomings set forth above. SUMMARY OF THE INVENTION One object of the present invention is to provide a solution to one or more of the problems set forth in the Background. According to one aspect of the present invention, the rod portion is decoupled from the plunger portion. This has the advantage of easing manufacturing as well as reducing the risk of bent rods during manufacturing and/or shipping. In a preferred embodiment, the rod portion comprises plastic material, which has an increased measure of elasticity compared to ferromagnetic material required for the plunger portion. In this preferred embodiment, the rod portion is configured to “snap” on a correspondingly-shaped end of the plunger. Another advantage of the present invention is that it eliminates the difficult to manufacture flutes referred to above that compensate for the damping and hydraulic forces effect of the oil. Rather, in another preferred embodiment, the rod portion and the plunger portion are both “hollow” providing a centrally disposed fluid pathway for damping/hydraulic force compensation. Still another advantage of the present invention is a guiding mechanism that exhibits reduced drag/friction, and which is preferably integral with a bobbin portion of the actuator. A solenoid portion of an actuator according to the present invention comprises a frame, a bobbin, a coil on the bobbin and a plunger assembly. The frame, which is part of the magnetic circuit is a deep drawn can produced from a magnetic sheet of steel, includes a longitudinal axis. The bobbin is disposed in the frame and includes a central cavity. The coil, which is wound on the bobbin, is provided for producing a magnetic field in at least the central cavity in response to a control signal applied to the coil. The plunger assembly is movably disposed in the central cavity. The plunger assembly includes a plunger portion secured to a rod portion. The plunger portion is formed of magnetic material to thereby be influenced by the magnetic field. In a preferred embodiment, the rod portion comprises plastic material configured to allow a predetermined amount of elastic deformation. The rod portion is removably secured to the plunger portion by way of a snap fit onto a forward end of the plunger portion. The foregoing reduces the occurrence of bent rods. In another aspect of the invention, both the rod portion and the plunger portion include respective through-bores. When secured to each other, the through-bores are in fluid communication. Through the foregoing, fluid damping/hydraulic force compensation may be obtained using the through-bores. This feature is an improvement over the conventional design, which relied on flutes machined on an outer surface of the steel rod that formed the plunger, which involved an expensive and relatively complex process. In yet another aspect of the invention, a guide is provided for maintaining alignment of the plunger assembly as it moves within the cavity. Preferably, the guide mechanism is integral with the bobbin, and includes a guiding post projecting axially into the cavity from a closed end of the bobbin cavity. A pair of guiding discs, offset one from another, extend radially outwardly from the guiding post. The diameter of the guiding discs is selected so as to correspond to the diameter of the through-bore in the plunger portion. This guide exhibits a reduced drag or friction characteristic inasmuch as the surface area of the outer periphery of the guiding discs facing the inner diameter of the plunger through-bore is substantially reduced compared to conventional approaches, which implement the guiding function using substantially the entire outer surface area of the plunger. Other objects, features and advantages will become apparent to those of ordinary skill in the art from the following detailed description of the preferred embodiments taken in connection with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be described by way of example, with reference to the accompanying drawings. FIG. 1 is a side, cross-sectional view of a conventional actuator. FIG. 2A is a side, cross-sectional view of an actuator according to the invention, in a de-energized state. FIG. 2A is a side, cross-sectional view of the actuator of FIG. 2A, in a fully energized state. FIG. 3 is a cross-sectional view of a plunger assembly included in the actuators of FIGS. 2A and 2B. FIG. 4 is a graph illustrating a force operating characteristic associated with the actuator of FIGS. 2A and 2B. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings in which the same reference numerals are used to identify identical components in the various views, FIG. 2A shows an actuator 30 in accordance with the present invention. Actuator 30, in FIG. 2A, is illustrated in a de-energized state and accordingly is shown in a fully retracted position (i.e., 0 mm of travel or stroke). With continued reference to FIG. 2A, actuator 30 includes a frame 32, a bobbin 34, a coil 36, a magnetic plate 38, and a plunger assembly 40. Frame 32 is configured to retain the main, internal components of actuator 30. Frame 32 may be generally cylindrical, having a longitudinal axis designated “A” in the drawings. Frame 32 may comprise metal material for strength and durability and magnetic properties. Bobbin 34 is disposed in housing 32 and is provided with a winding surface 42 and axially opposing winding flanges 44, 46 configured to receive coil 36. Bobbin 34 further includes a central cavity 48 configured in size and shape to, among other things, receive plunger assembly 40. In the illustrated embodiment, the cavity 48 is sized (oversized) to accommodate plunger assembly 40 yet allow for a defined fluid path to be formed around plunger assembly 40. With reference to FIG. 28, central cavity 48 includes an open end 50 and an axially opposing closed end 52. In addition, bobbin 34 is further formed with an integral guide 54, to be described in greater below, as well as with an integral mechanical stop 56. Bobbin 34, in a constructed embodiment, comprises electrically insulating material, such as various types of plastic, as known to those of ordinary skill in the art. Coil 36 is configured to establish a magnetic field in at least the central cavity 48 in response to an actuator control signal, designated S1 applied to coil 36. As shown, coil 36 is wound on bobbin 34, particularly on winding surface 42. Coil 36 may comprise magnetic wire, having suitable electrical characteristics (e.g., AWG) and a desired number of turns to achieve a predefined magnetic field strength, as within the knowledge of one of ordinary skill in the art. Magnetic plate 38 is configured as part of the magnetic circuit of actuator 30, as known to those of ordinary skill in the art. Plate 38 may be annular in shape and comprise magnetic material, for example, ferromagnetic material. In a preferred embodiment, plate 38 is insert molded directly into bobbin 34 in such a way so as to leave an annular isolation layer 58 between plunger assembly 40 in the cavity 48, on the one hand, and the inside diameter surface of annular plate 38, on the other hand. This isolation layer 58 is configured to minimize and/or prevent magnetic lock between plunger assembly 40 and magnetic plate 38 when plunger assembly 40 moves in cavity 48. Plunger assembly 40 is movably disposed in central cavity 48. Plunger assembly 40 includes a plunger portion 60 and a rod portion 62 removably secured to plunger portion 60. FIG. 3 is an enlarged, cross-section view of plunger assembly 40. In accordance with one aspect of the present invention, plunger portion 60 is decoupled and is a separate part from rod portion 62; that is, plunger portion 60 and rod portion 62 are not integral but may be secured to each other. Plunger portion 60 comprises magnetically permeable material and preferably comprises ferromagnetic material so as to be influenced by the magnetic field generated by coil 36. Plunger portion further includes a forward end 64 and an axially opposite back end 66. In the illustrated embodiment, the forward end 64 of the plunger portion 60 has a conical shape for a purpose to be described below. The back end is generally flat, as shown. In addition, plunger portion 60 includes a through-bore 68. Rod portion 62 includes a centrally-disposed through-bore 70. In addition, rod portion 62, at a first end thereof, has a funnel shape. The funnel shape at end 62 and the conical shape of the forward end 64 of plunger portion 60 correspond in both size and shape. Rod portion 62 comprises plastic or other material that possesses enough strength and durability suitable for the intended application, and, in addition, possesses a predetermined measure of elastic deformation. Through the foregoing, in one embodiment, the rod portion 62 may be removably secured to the plunger portion 60 by way of a snap fit of the funnel-shaped end of the rod onto the cone shaped end of the plunger (i.e., funnel-to-conical ends). While this is the preferred method of securing the rod portion to the plunger portion since it provides the advantage of ease of manufacturability and assembly (“snap”), other conventional approaches are within the spirit and scope of the present invention. Since rod 62 is made of non-magnetic material, it eliminates the need for a washer as required in conventional designs (e.g., FIG. 1), which acted as a magnetic brake between a primary plate (not shown) and the plunger. Additionally, the “hollow” rod portion 62 increases manufacturability by eliminating the machined flutes required by conventional systems for fluid flow/damping/hydraulic force compensation, as described in the Background. In accordance with the present invention, producing rod portion 62 having a predetermined amount of allowable elastic deformation reduces the occurrence of “bent” rod ends present in the prior “plunger,” as described in the Background. The occurrence is reduced because (i) the use of plastic provides a degree elastic deformation, and (ii) the rod portions can be handled/shipped separately with specific attention to protecting the extended rods. This improvement reduces the occurrence of failed actuators, for example, after initial assembly and test. When rod portion 62 is secured to plunger portion 60, the through-bores 68 and 70 are in fluid communication, one with the other, and are configured for fluid (e.g., oil) flow. In the illustrated embodiment, through-bore 68 is in registry with through-bore 70. In accordance with another aspect of the present invention, making the plunger assembly 40 “hollow” allows for the replacement of the flutes known in the art, as described in the Background. The through-bores 68, 70 are configured for fluid damping and to provide compensation of hydraulic forces in actuator 30 (i.e., the fluid can flow to the back end of the plunger assembly and thereafter surround the plunger assembly back to the front, equalizing the fluid pressure to some significant extent). Providing plunger assembly 40 that is “hollow” for achieving fluid dynamics control is an approach that is easier to implement that providing externally-formed flutes or the like. With continued reference to FIG. 2B, guide 54 is configured to cooperate with plunger portion 60, particularly through-bore 68, to align plunger assembly 40 within cavity 48. This improved alignment also optimizes, i.e., reduces variation, in the air gaps. Guide 54 is preferably integrated with bobbin 34. In the illustrated embodiment, guide 54 includes a guide post 72 that extends axially away from the closed end 52 into cavity 48. Post 72, again in the illustrated embodiment, has a pair of annular guiding discs 74, 76 extending radially outwardly from post 72. One of the pair of discs 74 is axially offset from the other one of the pair of discs 76. Each of the pair of discs 74, 76 has a diameter corresponding to the diameter of through-bore 68 at the back end of plunger portion 60. In accordance with yet another aspect of the present invention, the guide 54 is operative to reduce drag or friction compared to conventional approaches. Guide 54 helps reduce the “contact” or facing surface area between the plunger portion 60 and the remainder of the actuator. As described in the Background, the plunger (metal) in a conventional product, was disposed in a metallic guide cup. A very large portion of the inside diameter of the cup and the outside diameter of the plunger were coextensive, increasing drag/friction. In the present invention, the guiding function is performed by the pair of discs that collectively have a greatly reduced surface area in “contact” with the through-bore 68 of plunger assembly 60. In addition, the outside diameter of plunger portion 60 is surrounded by a plastic or other nonmetallic material that makes up the bobbin 34. Guide 54 further includes a stop feature 56 configured to minimize contact of the back end of plunger portion 60 with the closed end 52 of cavity 48. This stop feature is configured to reduce the occurrence of hydraulic lock that could occur when the back end contacts the closed end of the cavity. A description of the operation of actuator 30 will now be set forth. When the actuator control signal S1 applied to coil 36 is discontinued (i.e., is zero), plunger assembly 40 assumes its initial, rest, de-energized position, as shown in FIG. 2A. However, when the actuator control signal S1 in a non-zero state is applied to actuator 30, particularly coil 36 in the preferred embodiment, a magnetic field is established, as least in cavity 48. Plunger assembly 40 will move out of cavity 48 (i.e., away from closed end 52). The degree to which plunger assembly 40 will move can depend on the duty cycle of the signal S1. Accordingly, plunger assembly 40 moves forward, as shown in FIG. 2B. Rod 62, for example when coupled to a spool valve as described in the Background, as it moves within such a spool valve (not shown), may operate as a closure member, opening/closing various ports. FIG. 2B is representative of actuator 30 of FIG. 2A in a fully energized state. In one embodiment, the fully energized state corresponds to a 3 mm maximum stroke of rod 62. This maximum excursion, designated by reference numeral 78, may occur when a maximum magnetic force is induced at the maximum duty cycle. The actuator 30 may thus be arranged as a proportional actuator that can be commanded to any position from a fully retracted position (e.g., 0 mm of stroke) to a fully extended position (e.g., 3 mm of stroke). For example only, actuator 30 may be energized with a pulse width modulated (PWM) voltage signal that can operate from 100 Hertz (Hz) to 300 (Hz). FIG. 4 represents the operating characteristics of the solenoid actuator 30 of the present invention. A force vs. travel graph is generally indicated by reference numeral 80. The operating characteristic of a conventional, solid plunger type solenoid actuator is represented by dashed lines, while the present invention is represented by solid lines. Graph 80 illustrates that although the amount of magnetic material in the plunger portion has been reduced relative to the conventional design (“hollow” versus “solid”), the overall magnetic operating characteristic curves are not significantly affected. Actuator 30 may be usefully employed, for example only, as part of a cam phasing system, which may be used to improve engine performance, increase fuel economy and lower emissions, as set forth in a publication entitled A Verification Study for Cam Phaser Position Control using Robust Engineering Techniques, Society of Automotive Engineers (SAE) Publication No. 2001-01-0777, as described in the Background, and which is hereby incorporated by reference in its entirety. Although the present invention has been fully described in connection with the preferred embodiment thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of the present invention as defined by the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Solenoid actuators are well known in fluid flow control, where an orifice or aperture in a fluid flow path is to be opened or closed by means of a closure member such as a plunger, rod, spool or the like. Such actuators commonly comprise a magnetic circuit including a flux-generating coil, and a plunger formed of magnetic material moving under the influence of a magnetic field that changes in response to varying current flow through the coil. The plunger may be mechanically coupled to the closure member, which opens or closes the aperture or orifice in the fluid flow path as the plunger moves in accordance with changes in the magnetic field. In a particular arrangement, it is known to use a solenoid actuator as part of a camshaft control system (i.e., cam phaser position control). As known, the camshaft of an internal combustion engine may be employed to control the opening/closing of engine valves (e.g., intake, exhaust). As further background, then, cam phasing may be understood as the shifting of valve events in a crank angle (or cam angle) domain. Typically, a mechanical device is attached to the end of the camshaft for such purpose (“cam phaser”). The cam phaser may include an oil-actuated piston coupled to a gear train, a spool control valve for controlling the flow of oil to the piston, and an actuator for controlling the spool control valve. The actuator is driven by a pulse width modulated (PWM) signal from an engine control unit. The actuator includes a forward rod that extends into the spool valve and acts as a closure member, opening/closing various ports. As the duty cycle of the PWM signal is varied, the rod is caused to move to a controlled depth in the spool valve, controlling the flow of oil, for example, to one side or the other of the above-mentioned piston, thereby in-effect actuating the gear train in a controlled fashion. The gear train moves the camshaft. FIG. 1 is a cross-sectional, side view showing a conventional solenoid actuator 10 used in connection with the above-described cam phaser. Actuator 10 includes a solid plunger 12 having a rod portion 13 , a cup 14 , a magnetic coil 16 , a secondary plate 18 , a washer 20 and a bobbin 22 . Plunger 12 is a solid piece of ferromagnetic material, conical in shape at the front or at the tip, and is typically machined from a steel bar. Plunger 12 is also shown to include a plurality of axially extending flutes 24 formed in the outer surface of plunger 12 . Flutes 24 interact with the oil for damping and hydraulic force compensation. FIG. 1 is taken in section through a pair of such flutes; thus, flutes 24 shown in FIG. 1 are shown without cross-hatching. Cup 14 acts as a guide for plunger 12 and additionally isolates plunger 12 from secondary plate 18 . Cup 14 is a deep drawn component that is supported inside bobbin 22 to avoid fractures of the cup itself. Washer 20 is used as a magnetic brake between plunger 12 and primary plate 18 . In operation, plunger 12 moves within cup 14 in accordance with the magnetic force induced by the magnetic flux produced by coil 16 . Rod portion 13 is configured to extend into a spool control valve (not shown) for controlling oil flow, as described above. However, there are several shortcomings. First, the rod portion 13 of the integral plunger/rod 12 may become bent during the manufacturing operation (e.g., machining) or shipping, which may result in an inoperable actuator when assembled and tested. Second, the flutes, among other features, are relatively complex to manufacture. Third, the inside diameter surface of cup 14 (i.e., the guide) and the outside diameter surface of plunger 12 (i.e., the guided part) are coextensive over a relatively large area, thus increasing drag or friction therebetween. Fourth, a hydraulic lock (i.e., sticking) condition may occur when the rear of plunger 12 contacts the closed end of cup 14 . There is therefore a need for an improved actuator that minimizes or eliminates one or more of the shortcomings set forth above. | <SOH> SUMMARY OF THE INVENTION <EOH>One object of the present invention is to provide a solution to one or more of the problems set forth in the Background. According to one aspect of the present invention, the rod portion is decoupled from the plunger portion. This has the advantage of easing manufacturing as well as reducing the risk of bent rods during manufacturing and/or shipping. In a preferred embodiment, the rod portion comprises plastic material, which has an increased measure of elasticity compared to ferromagnetic material required for the plunger portion. In this preferred embodiment, the rod portion is configured to “snap” on a correspondingly-shaped end of the plunger. Another advantage of the present invention is that it eliminates the difficult to manufacture flutes referred to above that compensate for the damping and hydraulic forces effect of the oil. Rather, in another preferred embodiment, the rod portion and the plunger portion are both “hollow” providing a centrally disposed fluid pathway for damping/hydraulic force compensation. Still another advantage of the present invention is a guiding mechanism that exhibits reduced drag/friction, and which is preferably integral with a bobbin portion of the actuator. A solenoid portion of an actuator according to the present invention comprises a frame, a bobbin, a coil on the bobbin and a plunger assembly. The frame, which is part of the magnetic circuit is a deep drawn can produced from a magnetic sheet of steel, includes a longitudinal axis. The bobbin is disposed in the frame and includes a central cavity. The coil, which is wound on the bobbin, is provided for producing a magnetic field in at least the central cavity in response to a control signal applied to the coil. The plunger assembly is movably disposed in the central cavity. The plunger assembly includes a plunger portion secured to a rod portion. The plunger portion is formed of magnetic material to thereby be influenced by the magnetic field. In a preferred embodiment, the rod portion comprises plastic material configured to allow a predetermined amount of elastic deformation. The rod portion is removably secured to the plunger portion by way of a snap fit onto a forward end of the plunger portion. The foregoing reduces the occurrence of bent rods. In another aspect of the invention, both the rod portion and the plunger portion include respective through-bores. When secured to each other, the through-bores are in fluid communication. Through the foregoing, fluid damping/hydraulic force compensation may be obtained using the through-bores. This feature is an improvement over the conventional design, which relied on flutes machined on an outer surface of the steel rod that formed the plunger, which involved an expensive and relatively complex process. In yet another aspect of the invention, a guide is provided for maintaining alignment of the plunger assembly as it moves within the cavity. Preferably, the guide mechanism is integral with the bobbin, and includes a guiding post projecting axially into the cavity from a closed end of the bobbin cavity. A pair of guiding discs, offset one from another, extend radially outwardly from the guiding post. The diameter of the guiding discs is selected so as to correspond to the diameter of the through-bore in the plunger portion. This guide exhibits a reduced drag or friction characteristic inasmuch as the surface area of the outer periphery of the guiding discs facing the inner diameter of the plunger through-bore is substantially reduced compared to conventional approaches, which implement the guiding function using substantially the entire outer surface area of the plunger. Other objects, features and advantages will become apparent to those of ordinary skill in the art from the following detailed description of the preferred embodiments taken in connection with the drawings. | 20040220 | 20060214 | 20050825 | 58074.0 | 0 | DONOVAN, LINCOLN D | HOLLOW PLUNGER WITH GUIDE INTEGRATED TO BOBBIN ASSEMBLY | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,784,450 | ACCEPTED | Methods, apparatus and computer program products for dispatching and prioritizing communication of generic-recipient messages to recipients | Devices, methods and computer program products are provided for dispatching messages to recipients and for prioritizing the dispatch of generic-recipient messages. The device and methods are generally automatic and, thus, require minimal manual intervention by system administrators. Further, the devices and methods are capable of supporting both local and remote message dispatching so as to optimize the system and achieve a lowest cost alternative. In addition, the devices and methods of the present invention dispatch messages over various communication means, such as short-range wireless, Internet, cellular networks and the like. | 1. A method for determining one or more recipients of a generic-recipient message and for dispatch of the message within a digital communication network, the method comprising the steps of: receiving a generic-recipient message at a network hub; determining predefined attributes of the message; determining one or more recipients for the message based upon the predefined attributes; and dispatching the message to one or more recipients. 2. The method of claim 1, wherein the step of receiving a generic-recipient message at a network hub further comprises receiving a generic-recipient message, chosen from the group of messages consisting of a Short Message Service (SMS) message, a Multimedia Message Service (MMS) message, electronic mail (email) message and voice message. 3. The method of claim 1, wherein the step of receiving a generic-recipient message at a network hub further comprises receiving a message at a wireless network hub. 4. The method of claim 1, wherein the step of determining predefined attributes of the message further comprises determining predefined attributes chosen from the group of attributes consisting of type of message, sender of the message, subject of the message and content of the message. 5. The method of claim 1, wherein the step of determining one or more recipients for the message based upon the predefined attributes further comprises the step of correlating the predefined attributes of the message with stored information related to potential recipients. 6. The method of claim 1, wherein the step of dispatching the message to one or more recipients further comprises the step of assigning recipient Radio Frequency (RF) identifiers to the message. 7. The method of claim 1, wherein the step of dispatching the message to one or more recipients further comprises the step of displaying the message on a display. 8. The method of claim 8, wherein the step of displaying the message on a display further comprises displaying the message on a display associated with a radio frequency (RF) identifier. 9. The method of claim 1, wherein the step of dispatching the message to one or more recipients further comprises transmitting the message to one or more recipients via a communication medium chosen from the group of communication medium consisting of short-range wireless communication, Internet communication, SMS communication, and MMS communication. 10. A method for prioritizing a generic-recipient message at a network hub, the method comprising the steps of: receiving a generic-recipient message at a network hub; determining predefined attributes of the message; determining whether the message has priority based on the predefined attributes; and prioritizing the message if a determination is made that the message has priority. 11. The method of claim 10, wherein the step of determining whether the message has priority based on the predefined attributes further comprises determining whether the message has display priority based on the predefined attributes. 12. The method of claim 11, wherein the step of prioritizing the message if a determination is made that the message has priority further comprises prioritizing the display of the message if a determination is made that the message has display priority. 13. The method of claim 12, wherein the step of prioritizing the display of the message if a determination is made that the message has display priority further comprises the step of displaying the message in a prominent position on a display associated with the hub. 14. The method of claim 10, wherein the step of determining whether the message has priority based on the predefined attributes further comprises determining whether the message has dispatch priority based on the predefined attributes. 15. The method of claim 13, wherein the step of prioritizing the message if a determination is made that the message has priority further comprises prioritizing the dispatch of the message if a determination is made that the message has dispatch priority. 16. The method of claim 15, wherein the step of prioritizing the dispatch of the message if a determination is made that the message has dispatch priority further comprises the step of prioritizing the communication medium used to dispatch the message if a determination is made that the message has communication medium dispatch priority. 17. The method of claim 15, wherein the step of prioritizing the dispatch of the message if a determination is made that the message has dispatch priority further comprises the step of prioritizing the time of dispatch of the message if a determination is made that the message has time dispatch priority. 18. The method of claim 10, wherein the step of receiving a generic-recipient message at a network hub further comprises receiving a generic-recipient message, chosen from the group of messages consisting of a Short Message Service (SMS) message, a Multimedia Message Service (MMS) message, electronic mail (email) message and voice message. 19. The method of claim 10, wherein the step of receiving a generic-recipient message at a network hub further comprises receiving a generic-recipient message at a wireless network hub. 20. The method of claim 10, wherein the step of determining predefined attributes of the group-addresses message further comprises determining predefined attributes chosen from the group of attributes consisting of type of message, sender of the message, subject of the message and content of the message. 21. The method of claim 10, wherein the step of determining whether the message has priority based on the predefined attributes further comprises the step of correlating the predefined attributes of the message with stored information related to message priority. 22. A network hub device for determining one or more recipients for a generic-recipient message, the device comprising: a processing unit; a memory unit in communication with the processing unit, the memory unit stores information related to one or more potential recipients; a message reception application executed by the processing unit, the message reception application receives a generic-recipient message from one or more communication networks; and a message recipient determination and dispatch application executed by the processing unit, the message recipient determination and dispatch application determines predefined attributes of the generic-recipient message and compares the predefined attributes to the information related to the one or more potential recipients to determine one or more recipients. 23. The network hub device of claim 22, further comprising a Radio Frequency (RF) transceiver for dispatching the messages to one or more determined recipients via lower power RF. 24. The network hub device of claim 22, further comprising a Global System for Mobile communications (GSM) application for dispatching the message to one or more determined recipients via a digital cellular network. 25. The network hub device of claim 22, further comprising a communication network application for dispatching the message to one or more determined recipients via a communication network. 26. The network hub device of claim 25, wherein the communication network is chosen from the group consisting of the Internet, a Short Message Service (SMS) network, a Multimedia Message Service (MMS) network and a telephony network. 27. The network hub device of claim 22, further comprising a display associated with the network hub that displays a message associated with a message identifier. 28. The network hub device of claim 27, wherein the message identifier is further defined as a Radio Frequency (RF) identifier. 29. A network hub device for prioritizing generic-recipient messages, the hub comprising: a processing unit; a memory unit in communication with the processing unit, the memory unit stores priority information; a message reception application executed by the processing unit, the message reception application receives generic-recipient messages from one or more communication networks; and a message priority application executed by the processing unit, the message priority application determines predefined attributes of received generic-recipient messages and compares the predefined attributes to the priority information to determine if the received message requires prioritization. 30. The network hub device of claim 29, wherein the memory unit stores display priority information and the message priority application is further defined as a message display priority application that determines predefined attributes of received generic-recipient messages and compares the predefined attributes to the display priority information to determine if the received messages require display prioritization. 31. The network hub device of claim 30, further comprising a display associated with the network device that displays message identifiers to one or more recipients. 32. The network hub device of claim 30, wherein the message display priority application further provides for display prioritization to be chosen from the group consisting of displaying prioritized messages first in a list of messages, displaying prioritized messages in a new viewable window and displaying prioritized messages in a highlighted form. 33. The network hub device of claim 29, wherein the memory unit stores dispatch priority information and the message priority application is further defined as a message dispatch priority application that determines predefined attributes of received generic-recipient messages and compares the predefined attributes to the dispatch priority information to determine if the received messages require dispatch prioritization. 34. The network hub device of claim 33, wherein the message dispatch priority application further provides for dispatch prioritization to be chosen from the group consisting of prioritizing the time at which messages will be dispatched, prioritizing the communication medium used to dispatch messages and prioritizing the recipients of the dispatched messages. 35. The network hub device of claim 27, wherein the message priority application determines predefined attributes of the received generic-recipient messages, the predefined attributes chosen from the group consisting of a sender of the message, a type of the message, a subject of the message and the content of the message. 36. A computer program product for automatically determining one or more recipients of a generic-recipient message and dispatching the message to the one or more recipients within a digital communication network, the computer program product comprising a computer readable storage medium having computer-readable program instructions embodied in the medium, the computer-readable program instructions comprising: first instructions for storing information related to potential message recipients; second instructions for receiving a generic-recipient message at a network hub and determining predefined attributes associated with the generic-recipient message; and third instructions for determining one or more recipients of the generic-recipient message by comparing the predefined attributes associated with the generic-recipient message to the stored information related to potential message recipients. 37. The computer program product of claim 36, wherein the computer-readable program instructions further comprise fourth instructions for dispatching the message to the one or more determined recipients. 38. The computer program product of claim 36, wherein the second instructions for receiving a generic-recipient message at a network hub and determining predefined attributes associated with the generic-recipient message further comprises second instructions for receiving a generic-recipient message, chosen from the group of messages consisting of a Short Message Service (SMS) message, a Multimedia Message Service (MMS) message, electronic mail (email) message and voice message. 39. The computer program product of claim 36, wherein the second instructions for receiving a generic-recipient message at a network hub and determining predefined attributes associated with the generic-recipient message further comprises second instructions for receiving a generic-recipient message at a wireless network hub. 40. The computer program product of claim 36, wherein the second instructions for receiving a generic-recipient message at a network hub and determining predefined attributes associated with the generic-recipient message further comprises second instructions for determining predefined attributes associated with the generic-recipient message chosen from the group of attributes consisting of type of message, sender of the message, subject of the message and content of the message. 41. The computer program product of claim 37, wherein the fourth instruction for dispatching the message to one or more recipients further comprises assigning recipient Radio Frequency (RF) identifiers to the message. 42. The computer program product of claim 37, wherein the fourth instructions for dispatching the message to one or more recipients further comprises displaying the message on a display associated with the network hub. 43. The computer program product of claim 42, wherein the fourth instructions for displaying the message on a display associated with the network hub further comprises fourth instructions for displaying the message, which is associated with a Radio Frequency (RF) identifier, on a display associated with the network hub. 44. The computer program product of claim 37, wherein the step of dispatching the message to one or more recipients further comprises transmitting the message to one or more recipients via a communication medium chosen from the group of communication medium consisting of short-range wireless communication, Internet communication, SMS communication, and MMS communication. 45. A computer program product for prioritizing generic-recipient messages at a network hub, the computer program product comprising a computer readable storage medium having computer-readable program instructions embodied in the medium, the computer-readable program instructions comprising: first instructions for storing information related to message priority; second instructions for receiving a generic-recipient message at a network hub and determining predefined attributes associated with the generic-recipient message; and third instructions for determining whether the generic-recipient message has priority by comparing the predefined attributes associated with the generic-recipient message to the stored information related to message priority. 46. The computer program product of claim 45, wherein the first instructions for storing information related to message priority further comprises first instructions for storing information related to message display priority and the third instructions for determining whether the generic-recipient message has priority further comprises third instructions for determining whether the generic-recipient message has display priority by comparing the predefined attributes associated with the generic-recipient message to the stored information related to message display priority. 47. The computer program product of claim 45, wherein the first instructions for storing information related to message priority further comprises first instructions for storing information related to message dispatch priority and the third instructions for determining whether the message has priority further comprises third instructions for determining whether the message has dispatch priority by comparing the predefined attributes associated with the messages to the stored information related to message dispatch priority. 48. The computer program product of claim 45, wherein the second instructions for receiving a generic-recipient message at a network hub and determining predefined attributes associated with the message further comprises second instructions for receiving a generic-recipient message, chosen from the group of messages consisting of a Short Message Service (SMS) message, a Multimedia Message Service (MMS) message, electronic mail (email) message and voice message. 49. The computer program product of claim 45, wherein the second instructions for receiving a generic-recipient message at a network hub and determining predefined attributes associated with the message further comprises second instructions for receiving a generic-recipient message at a wireless network hub. 50. The computer program product of claim 45, wherein the second instructions for receiving a generic-recipient message at a network hub and determining predefined attributes associated with the message further comprises second instructions for determining predefined attributes associated with the message chosen from the group of attributes consisting of type of message, sender of the message, subject of the message and content of the message. | FIELD OF THE INVENTION This invention relates to messaging in a digital communication network, and more particularly, relates to determining recipients and dispatching generic-recipient messages in a digital communication network. BACKGROUND OF THE INVENTION In today's business environment an individual receives digital messages from various sources and by various communication means. For example, an individual may receive messages from a fellow employee, from a customer, from a supplier or from any other relevant business contact. The sender of message may be internally located at the same worksite as the individual receipt, as typically is the case with fellow employees, or may be externally located outside of the workplace, as typically is the case with customers or suppliers. In addition to the variance in message source, digital messages are communicated to individuals by various digital means, such as electronic mail, voice mail, Short Message Service (SMS) communication, Multimedia Message Service (MMS) communication and the like. Moreover, the recipient of these messages is provided multiple means for receiving the messages. For example, email accounts can be accessed from a personal computer, a wired or wireless laptop computer, a wireless Personal Digital Assistant (PDA), a wireless cellular telephone or any other conceivable wired or wireless device capable of digital communication. Even voice mail, once limited to access via the wired or wireless telephone, can now be accessed via the personal computer, laptop computer, PDA or the like. The vast majority of the digital messaging communication is conducted on a person-to-person basis. For example, one individual sends another individual an email or an SMS communication or one individual initiates a cellular telephone call to another individual. Much more limited are the communication options for person-to-group, person-community, person-to-place or person-to-application communication. This type of communication is also referred to herein as generic-recipient message, in which the user does not send the message to a specific individual but rather to a group, a community, a location or an application. Email allows an individual to send a group email to multiple recipients; however, in this regard the user forms the group email address from a collection of known individual email addresses. In practice, the group email provides person-to-person communication to multiple recipients. The group email communication does not allow the sender to send an email correspondence to a group if the sender is unaware of the individuals that form the group. The concept of generic-recipient messaging is best explained by providing examples. An individual wishes to contact Company X and inquire about the status of a particular product that they recently ordered from Company X. The individual wishes to communicate via email. Unless the individual is aware of the specific individual within Company X that is handling this order, email communication can become somewhat problematic. Typically, the individual's only email option is to send an email correspondence to a generic Company X email address and have a system administrator manually dispatch the email to a perceived intended recipient. Thus, the sender of the email is provided very little assurance that the email will be dispatched to the proper entity handling the order. In many of these instances, the individual's email is dispatched to the incorrect recipient and, thus, the individual never receives an appropriate reply. This same dilemma presents itself in the example of an individual trying to contact Company X via telephone communication to status an outstanding order. The individual is unaware of the direct line telephone number of the individual handling the account and, thus, the only option presented to the individual is to contact Company X's main switchboard and either ask for a specific department or explain to the main switchboard operator the question at hand. All too often the switchboard operator will dispatch the call to the incorrect recipient, thus, frustrating the individual who is trying to status an outstanding order. In other instances, the switchboard operator is unaware of whether a recipient is available to receive the call and will invariably lead the individual caller into the unavailable recipient's voice mail system. In the same regard, automated key-tone or voice command systems, which obviate the need for a switchboard operator, are often cumbersome and confusing to the user and provide even greater opportunity to dispatch the call to an incorrect recipient. In addition to properly dispatching these generic-recipient messages to proper recipients, a need exists to identify and prioritize the dispatch of generic-recipient messages that require priority dispatching. For example, in the email scenario the sender of the email may emphasize the messages importance by flagging the message or otherwise highlighting the subject header or contents or the message. However, if the sender of the email fails to designate the message as a priority message, it is unlike that the system administrator who dispatches the message will recognize the importance and subjectively provide for the requisite higher priority. Additionally, even in the instance in which the system administrator receives a message marked by the sender as requiring priority, manual dispatch provides no assurance that the priority will be forwarded to the determined recipient upon dispatch. Therefore, a need exists to develop a system and methods for dispatching generic-recipient messages to proper recipients. The desired system should function without an expensive private telephone network or a central system for short incoming text, graphic or voice communication. In addition, the desired dispatch system should be generally automatic and, thus, require minimal manual intervention by system administrators. The desired system and method should be capable of supporting both local and remote generic-recipient message dispatching so as to achieve a lowest cost alternative. In addition, the desired system and method should support the dispatch of generic-recipient messages over various communication means, such as short-range wireless, Internet, cellular networks and the like. A need also exists to develop a system and methods for providing dispatch priority to generic-recipient messages. The desired system should provide for multiple priority schemes, such that priority can be given to generic-recipient messages depending on the communication network used to dispatch the message. Additionally, the priority system and methods should be automated to allow for message priority to be determined with minimal manual intervention by system administrators. BRIEF SUMMARY OF THE INVENTION The present invention provides for devices, methods and computer program products for dispatching generic-recipient messages to determined recipients and for prioritizing the dispatch of generic-recipient messages. The invention utilizes a network hub device that receives generic-recipient messages and executes a dispatch application to determine one or more recipients. The system functions without an expensive private telephone network or a central system for short incoming text or voice communication. The generally automatic nature of the dispatch application provides for minimal manual intervention by system administrators. In addition, the network hub is typically located within the network such that it is capable of supporting both local and remote message dispatching. The network hub device and associated methods support dispatch of generic-recipient messages over various communication means, such as short-range wireless, Internet, cellular networks and the like. In one embodiment, the network hub is associated with a display device, such that received generic-recipient messages can be prominently displayed to potential recipients prior to dispatch via short-range wireless communication. In addition, the network hub device may be a wireless device to provide for physical portability of the hub. Additionally the network hub and related methods may execute a dispatch priority application that automatically attaches dispatch priority to messages based on predefined priority attributes. Multiple priority schemes are feasible to accommodate for the communication network used to dispatch the message. For example, a message that will be prominently displayed prior to dispatch may be granted display priority or priority may be defined by the communication network used to dispatch a message. The invention may be defined by a method for determining a recipient of a generic-recipient message and dispatching the message to the determined recipient. The method includes the steps of receiving a message at a network hub, determining predefined attributes of the received message, determining the recipients for the message based upon the predefined attributes and dispatching the message to the determined recipients. The message may be a Short Message Service (SMS) message, a Multimedia Message Service (MMS) message, an electronic mail (email) message, a voice message or the like. The network hub will typically be a wireless network hub, although a wired network hub is also within the concepts of the present invention. The predefined attributes of the message may include the type of message (i.e., SMS, MMS, email, voice, etc.), the sender of the message, the subject of the message and the content of the message. The step of determining the recipients for the message based upon the predefined attributes may further include the step of correlating the predefined attributes of the message with stored information related to potential recipients. The step of dispatching the message to the determined recipients may further include the step of assigning recipient Radio Frequency (RF) identifiers to the message. In this regard, message recipients may receive the message by communicating with the network hub via an RF tag and corresponding RF reader. Additionally, the step of dispatching the message to the determined recipients may further include the step of displaying the message on a display associated with the network hub. By displaying the messages on a display potential recipients can view, at least a portion of, the message such as the subject header and determine if they are the determined recipient of the message. If a potential recipient determines that they are the intended recipient they may receive the message by short-range wireless communication techniques, such as RFID communication or the like. The dispatching of the message to the determined recipients may involve transmitting the message to the determined recipients via a standard communication medium, such as short-range wireless communication, Internet communication, SMS communication, MMS communication or the like. In a further embodiment of the invention a network hub device for determining recipients of generic-recipient messages and dispatching the to determined recipients is defined. The network hub device includes a processing unit and a memory unit in communication with the processing unit that stores information related to the potential recipients. Additionally, the network hub includes a message reception application executed by the processing unit that receives generic-recipient messages from various communication networks and determines predefined attributes of received messages. The network hub also includes a message recipient determination and dispatch application executed by the processing unit that compares the predefined attributes to the information related to the potential recipients to determine the recipients. The network hub may further include a Radio Frequency (RF) transceiver for dispatching assigned messages to determined recipients via lower power RF communication. Additionally, the network hub may include a Global System for Mobile communications (GSM) application for dispatching messages to determined recipients via a digital cellular network or a similar communication network application, such as an Internet application, a Short Message Service (SMS) application, a Multimedia Message Service (MMS) application or the like. The network hub device may also include an associated display that visually displays, at least a portion of, the message. By displaying the assigned messages on a display potential recipients can view the message and determine if they are the intended recipients of the message. If a potential recipient determines that they are the intended recipient they may receive the message by short-range wireless communication techniques, such as RFID communication or the like. In yet another embodiment of the invention a computer program product is described for automatically determining recipients of generic-recipient messages. The computer program product includes a computer readable storage medium having computer-readable program instructions embodied in the medium. The computer-readable program instructions include first instructions for storing information related to potential message recipients and second instructions for receiving a message at a network hub, typically a wireless network hub, and determining predefined attributes associated with the message. The message may include any conventional digital message such as, a Short Message Service (SMS) message, a Multimedia Message Service (MMS) message, an electronic mail (email) message and a voice message. The predefined attributes associated with the message may include the type of message, sender of the message, subject of the message and content of the message. Additionally, the computer-readable program instructions includes third instructions for determining the message recipients of the message by comparing the predefined attributes associated with the messages to the stored information related to potential message recipients. The computer-readable program instructions may further include fourth instructions for dispatching the message to the determined message recipient(s). Dispatching may involve communicating the messages via short-range wireless communication, wired or wireless Internet communication, SMS communication, MMS communication or the like. Dispatching may include the step of assigning recipient Radio Frequency (RF) identifiers to the message. In this regard, a transponder within the network hub may communicate via RF with tags in the possession of the recipients. Additionally, dispatching may include displaying, at least a portion of the message on a display associated with the network hub, so that intended recipients are visually aware that messages are designated for their receipt. The invention is further defined by a method for prioritizing generic-recipient messages at a network hub. The method includes the steps of receiving a message at a network hub, determining predefined attributes of the received message, determining whether the message has priority based on the predefined attributes and prioritizing the message if a determination is made that the message has priority. The generic-recipient messages will typically include various message formats including SMS, MMS, email and voice message. The network hub will typically be a wireless network hub, however; a wired network hub is also possible. The step of determining whether the message has priority based on the predefined attributes may further include determining whether the message has display priority based on the predefined attributes. Display priority may take the form of displaying the prioritized message in a prominent position on a display associated with the hub, create a pop-up type window for the display of the prioritized message or otherwise highlighting the display of the prioritized message. Additionally, the step of determining whether the message has priority based on the predefined attributes may further include determining whether the message has dispatch priority based on the predefined attributes. Dispatch priority may take the form of prioritized the communication medium used to dispatch the message, prioritizing a sequence of recipients to whom the message may be dispatched, prioritizing the time of dispatch and the like. The step of determining predefined attributes of the group-addresses message may define the predefined attributes as the type of message, the sender of the message, the subject of the message, the content of the message or any other message attribute may be included as a predefined parameter. The invention is also embodied in a network hub device for prioritizing generic-recipient messages. The network hub device includes a processing unit, a memory unit in communication with the processing unit that stores priority information, a message reception application executed by the processing unit that receives generic-recipient messages from one or more communication networks and determines predefined attributes of received generic-recipient messages. The network hub also includes a message priority application executed by the processing unit that compares the predefined attributes to the priority information to determine if the received message requires prioritization. The predefined attributes will typically include attributes defined in the message, such as a sender of the message, a type of the message, a subject of the message, the content of the message and the like. Prioritization may be defined as display prioritization or dispatch prioritization. In network hubs that define priority in terms of display priority, the memory unit will store display priority information and the message priority application will compare the predefined attributes to the display priority information to determine if the received message requires display prioritization. In those embodiments that implement display priority, the network hub may include a display associated with the hub that displays the messages. Display prioritization may take the form of listing prioritized messages first, displaying prioritized messages in a pop-up style window or otherwise highlighting the display of the prioritized message. In network hubs that define priority in terms of dispatch priority, the memory unit will store dispatch priority information and the message priority application will compare the predefined attributes to the dispatch priority information to determine if the received message requires dispatch prioritization. Dispatch priority may take the form of prioritizing the time at which messages are dispatched, the communication medium used to dispatch the message or a priority sequence of whom the message will be dispatched to. In yet another embodiment of the invention a computer program product is described for prioritizing generic-recipient messages at a network hub. The computer program product includes a computer readable storage medium having computer-readable program instructions embodied in the medium. The computer-readable program instructions include first instructions for first instructions for storing information related to message priority and second instructions for receiving a message at a network hub and determining predefined attributes associated with the message. The group message priority information may be display priority information or dispatch priority information. The message may include any conventional digital message such as, a Short Message Service (SMS) message, a Multimedia Message Service (MMS) message, an electronic mail (email) message and a voice message. The predefined attributes associated with the message may include the type of message, sender of the message, subject of the message and content of the message. Additionally, the computer-readable program instructions includes third instructions for determining whether the message has priority by comparing the predefined attributes associated with the generic-recipient messages to the stored information related to message priority. Therefore, the present invention provides for devices, methods and computer program products for determining a recipient for a generic-recipient message, dispatching the generic-recipient message to determined recipients and prioritizing the dispatch of the generic-recipient message. The device and methods function without an expensive private telephone network or a central system for short incoming text or voice communication. In addition, the device and methods are generally automatic and, thus, require minimal manual intervention by system administrators. Further, the devices and methods are capable of supporting both local and remote message dispatching so as to optimize the system and achieve a lowest cost alternative. In addition, the devices and methods of the present invention dispatch generic-recipient messages over various communication means, such as short-range wireless, Internet, cellular networks and the like. The devices and methods also provide for multiple priority schemes, such that priority can be given to messages depending on the communication network used to dispatch the message. Additionally, the priority system and methods should be automated to allow for message priority to be determined with minimal manual intervention by system administrators. BRIEF DESCRIPTION OF THE DRAWINGS Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale. FIG. 1 is block diagram illustrating the network hub and messages that are typically trafficked at the hub, in accordance with an embodiment of the present invention. FIG. 2 is block diagram of a system incorporating a network hub for automated recipient determination of generic-recipient messages, message dispatching and/or message prioritizing, in accordance with an embodiment of the present invention. FIG. 3 is a block diagram of a network hub device that executes automated recipient determination of generic-recipient messages, message dispatching and/or message prioritizing, in accordance with one embodiment of the present invention. FIG. 4 is a block diagram of recipient-determined messages being displayed and awaiting short-range wireless dispatch, in accordance with one embodiment of the present invention. FIGS. 5A and 5B are block diagrams of examples of information fields for stored messages and stored potential recipients, in accordance with an embodiment of the present invention. FIG. 6 is a flow diagram depicting a method for automated priority assignment and dispatch of generic-recipient messages, in accordance with one embodiment of the present invention. FIGS. 7A and 7B are flow diagrams depicting manual and automated methods for dispatch of messages implementing short-range wireless dispatch, in accordance with embodiments of the present invention. FIG. 8 is a flow diagram depicting a method for automated dispatch of messages implementing short-range wireless dispatch, in accordance with embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. The present invention is defined by methods, devices and computer programs for determining recipients of generic-recipient messages, dispatching the generic-recipient messages to the determined recipients and for prioritizing the dispatch of the generic-recipient messages. The invention utilizes a network hub device that receives generic-recipient messages and executes a message recipient determination and dispatch application to determine one or more recipients for the message and to dispatch the message to the recipients. The system functions without an expensive private telephone network or a central system for short incoming text or voice communication. The generally automatic nature of the dispatch application provides for minimal manual intervention by system administrators. In addition, the network hub is typically located within the network such that it is capable of supporting both local and remote message dispatching. The network hub device and associated methods support dispatch of messages over various communication means, such as short-range wireless, Internet, cellular networks and the like. In one embodiment, the network hub is associated with a display device, such that messages can be prominently displayed to determined recipients prior to dispatch via short-range wireless communication. In addition, the network hub device may be a wireless device to provide for physical portability of the hub. FIG. 1 represents the network hub device 10 and examples of environments in which the network hub is utilized. For example, the network hub may be utilized in a community environment 12 in which individual send messages to a specified family, workgroup or the like. Upon receipt of the community message, the network hub determines which family or workgroup member the message is intended for or which family or workgroup member is most appropriate for receipt of the message. In the community environment the workgroup may be located at different worksites and the family may reside at different residences. The community environment is in contrast to the location environment 14, in which individuals send messages to a specific local, such as an office, a home, a school or the like. Upon receipt of the location message, the network hub determines which individual or individuals within the location the message is intended for or which individual or individuals within the location is/are most appropriate for receipt of the message. Similar to the community environment 12, the network hub may be utilized in a group environment 16 in which individuals send messages to a specific organization, corporation or club. Upon receipt of the group message, the network hub determines which individual or individuals within the group the message is intended for or which individual or individuals within the group is/are most appropriate for receipt of the message. In the group environment the potential recipients may be physically located anywhere. Another example is utilization of the network hub in connection with certain applications 18, such as Short Message Servicing chat or vote or Multimedia Message Service boards. Additionally the network hub and related methods may execute a dispatch priority application that automatically attaches dispatch priority to generic-recipient messages based on predefined priority attributes. Multiple priority schemes are feasible to accommodate for the communication network used to dispatch the message. For example, a message that will be prominently displayed prior to dispatch may be granted display priority or priority may be defined in the communication network used to dispatch a message. FIG. 2 is a block diagram illustrating a communications network that incorporates a network hub device, in accordance with an embodiment of the present invention. The communications network 10 includes a network hub device 20 that serves to determine recipients of generic-recipient messages, dispatch the messages to the determined recipients and/or prioritize the generic-recipient messages. In the illustrated embodiment the network hub is a wireless network hub, however; in alternate embodiments of the invention the network hub may be a conventional wired network hub. The wireless embodiment of the network hub provides for device portability. The network hub device 20 is capable of receiving, dispatching and/or prioritizing generic-recipient messages from various communication sources. The FIG. 2 embodiment illustrates an example of four distinct communication sources. User generated Short Message Service (SMS) or Multimedia Message Service (MMS) messages 30 can be communicated to the network hub, typically through intermediary network points, such as SMS or MMS center 40 or a network mail server 50. In a similar fashion, machine generated SMS or MMS messages 60 can be communicated to the network hub, typically through intermediary network points, such as SMS or MMS center 40 or a network mail server 50. The network hub may also receive messages from user generated email 70 communication that is communicated via a network mail server 50. In addition, the network hub may receive voice messages 80 communicated, wirelessly or wired, over a standard telephony network. In the FIG. 2 embodiment the network hub 20 is physically located at a place of employment 90. However, the network hub of the present invention may be physically located at other advantageous locations within the communication network 10 without departing from the inventive concepts herein disclosed. Physical location at a place of employment is illustrated here to highlight various optional advantageous features of the present invention, such as low power short-range communication capabilities. In this same regard, the network hub could be physically located at other locales that typically receive messages and require dispatch of the messages. In the illustrated embodiment the network hub is in communication with an optional display 100. The optional display serves as a joint message board and, as such, the display may be a conventional personal computer display or the display may be a large bulletin board display capable of being viewed simultaneously by multiple employees within the viewing area. The display allows for the messages that have been assigned recipient(s) to be displayed, typically in an abbreviated list type format, such that employees that view the display can determine if a message has been assigned for their dispatch. In one embodiment of the invention dispatch of the messages may be accomplished by short-range communication, such as Radio Frequency Identification (RFID), Bluetooth®, or any other suitable form of short-range communication. In the RFID scenario, the employee is equipped with an RFID tag 110 and the network hub embodies a tag reader (not shown in FIG. 2). The tag may be embodied within an identification card, a key fob or within a device, such as a cellular telephone, personal digital assistant (PDA) or the like. The employee will routinely bring the tag in the general vicinity of the tag reader, commonly referred to as “swiping” the tag, for the purpose of receiving messages that have been assigned to the employee. Alternatively, the device, such as a cellular telephone, PDA or the like, may be equipped with a tag reader and the tag may be embodied in the network hub or a device associated with the network hub. In this regard, the optional display serves to provide notice to an employee that a message has been dispatched to their attention and allows the employee to non-routinely bring their tag or reader in the general vicinity of the corresponding tag reader or tag (i.e., the network hub), for the purpose of receiving the message. FIG. 3 provides a block diagram of a network hub 400, in accordance with an embodiment of the present invention. In this embodiment of the invention the network hub is in communication with a display that lists, within the viewable area 410 of the display, an identifiable portion of the assigned message 420, typically the subject header, the sender and/or the determined recipient. The order of the listing of the assigned messages may be determined by the temporal order of receipt at the network hub or the order may be determined by a priority application implemented at the network hub, which is discussed at length infra. In one embodiment of the invention, each message will be assigned a short-range wireless communication identifier, such as an LPRF identifier 430, at the network hub. The identifier will typically associate the message with one or more recipients or, more specifically, the tag associated with the recipients receiving device (i.e., cellular telephone, PDA or the like). As such, in embodiments in which the network hub possesses short-range wireless communication capability, the hub is equipped with an appropriate transceiver, processor/controller, antennae and serial data system to provide for short-range wireless communication. In addition to short-range communication, the network hub may be configured to dispatch messages by other conventional communication means. For example, the network hub may be configured to dispatch messages to off-site employees 120 or any other external entity by communication means, such as email communication, Short Message Service (SMS) communication, Multimedia Message Service (MMS) communication, voice communication, paging communication or the like. The external communication of messages may be wireless communication or it may be wired communication. Additionally, the network hub may be configured to dispatch messages to on-site employees 130 or any other internal entity by communication means such as email communication, Short Message Service (SMS) communication, Multimedia Message Service (MMS) communication, voice communication, paging communication or the like. In addition to dispatching received generic-recipient messages, the network hub may be configured to send messages either internally within the physical confines of the hub, typically by short-range wireless communication, or externally, typically by SMS, MMS, email or voice communication. FIG. 4 is a block diagram illustrating the architecture of a network hub, in accordance to an embodiment of the present invention. In the illustrated embodiment the network hub is configured to automatically determine a recipient of a generic-recipient message, dispatch the generic-recipient message to the determined recipient and/or prioritize the generic-recipient message according to a chosen predetermined parameter. However, in alternate embodiments of the present invention the network hub may be configured such that it implements either, but not both, automatic determination of a recipient of a generic-recipient message and subsequent dispatch or prioritization of generic-recipient messages. The network hub device 20 will include a central processing unit (CPU) 200 that it is communication with a storage unit or memory device 210. The memory device may store information related to potential recipients of generic-recipient messages (i.e., employees or the like), information related to priority attributes or the like. The processing unit will execute an operating system 220 that controls the peripheral devices and provides a software platform for application routines. The operating system may be Windows® (Microsoft Corporation, Redmond, Wash.) based, OS/2 (Apple Corporation, Cupertino Calif.) based, an open-source operating system, such as Linux or any other suitable operating system. The processing unit of the network hub will additionally, typically, execute middleware 230 that provides for connectivity between separate and distinct applications. In the present of the middleware provides a link between the message reception logic 240, the message recipient determination and dispatch logic 250 and the message priority logic 260. The message reception logic 240, also referred to as the message reception application is executed by the central processing unit 200 and is responsible for receiving generic-recipient messages from one or more communication networks, such as a SMS network, a MMS network, an email network, telephone network or the like. The message reception logic is typically in communication with message storage 270 that provides for the storage of messages and information related to received messages. The message recipient determination and dispatch logic 250, also referred to as the message recipient determination and dispatch application, is executed by the central processing unit 200 and is responsible for determining recipients for messages. The message recipient determination and dispatch logic determines predefined attributes of interest related to the generic-recipient messages, such as the message sender, the message subject, the message form, the message content and the like. Once the predefined attributes of interest are determined they are compared to recipient information stored in memory device 210. The comparison process will logically determine one or more recipients for the message. The network hub may additionally include message priority logic 260, also referred to as the message priority application, which is executed by the central processing unit 200 and is responsible for determining dispatch priority for the generic-recipient messages received at the network hub device. The message priority application may prioritize the messages in terms of display priority, recipient dispatch priority, mode of dispatch or any other priority designated by the message or the recipient. The message priority application will determine priority either based on the receipt information stored in memory device 210 or based on predefined attributes related to the message, such as sender, content, subject, etc. In one embodiment of the invention the message priority application will determine display priority. Display priority provides for assigned messages that are determined to have display priority to be displayed, typically on a display associated with the network hub, in a prioritized fashion. Prioritized fashion may include listing the priority messages first, creating a separate pop-up-type window for a priority message, highlighting the priority message or otherwise prominently featuring the priority message. In an alternate embodiment the message priority application may prioritize dispatch recipients. For example, a message determined to be sent from sender “X”, is first dispatched to employees “A”, “B” and “C”. If no receipt acknowledgement is received by the hub from employees “A”, “B” and “C” within a specified time period, the message is then dispatched to the supervisor of employees “A”, “B” and “C”. If no receipt acknowledgement by the hub from the supervisor within a specified time period, the message is then dispatched to the site manager. Further, the message priority application may prioritize the mode of dispatch. For example, messages sent from a predefined sender or messages including predefined content, such as, voice communication, in the form of a telephone call or voice mail. In other embodiments of the message priority application priority may be determined by the application of the network hub and the priority desired by the users of the network hub. Additionally, the network hub 20 may include a display driver 280 that is executed by the CPU 200 and provides for control over a display (not shown in FIG. 4) that is associated with the network hub. An associated display provides for the network hub to display messages that have are either awaiting dispatch or have been dispatched. The network hub may additionally include a Global System for Mobile communication (GSM) engine 290 that provides for the network hub to receive and transmit digital cellular communications and/or a Low Power Radio Frequency (LPRF) transponder 300. The LPRF transponder provides for the network hub to transmit messages, via short-range wireless communication, to devices equipped with LPRF tags. FIGS. 5A and 5B provide examples of message information and potential recipient information stored at the network hub, in accordance with an embodiment of the present invention. For example, FIG. 5A provides received message information fields, including message identification 500, sender 510, type 520, subject 530 and content 540. The message identification field may include a message id number, an email address or some other form of message identification. The sender field will identify the name of the individual who sent the message. The type field will indicate the type of message, such as email message, SMS message, MMS message, voice message or the like. The subject field will identify the subject matter of the message, such as found in an email header listing. The content of the message may include the entire content of the message or an abbreviated form of the content of the message. In addition, the message information fields may include message priority 550, time sent 560, time received 570, dispatched status 580, dispatched recipient 590 and acknowledgement status 600. The message priority field will be provided for in those embodiments of the invention that implement message priority and will indicate whether the message has been determined to be a priority message. The time sent and the time received fields will indicate the time at which the sender of the message transmitted the message and the time at which the network hub received the message. The dispatch status will indicate whether the message has been dispatched. For example, in short-range communication dispatch will occur when the tag (i.e., the recipients device) comes in close proximity with the hub, such that the tag is read by the hub. In other scenarios, dispatch may occur when the message is transmitted via email, SMS or some other form of network communication. The dispatched recipient field will identify the one or more recipients of the message as determined by the message recipient determination and dispatch application. The acknowledgement field will indicate whether the message has been dispatched and received by the determined recipients. FIG. 5B provides an example of information stored at the network hub related to potential recipients of generic-recipient messages, in accordance with an embodiment of the present invention. The network hub uses stored information related to potential recipients to determine whom a message is dispatched to and to determine how it is dispatched. The potential recipient information fields may include a potential recipient ID 610, a Mobile Station International ISDN Number (MSISDN) 620, Bluetooth MAC address 630, WLAN MAC address 640, instant message address 650 and email address 660. The potential recipient ID will typically be used when the potential recipients are employees or some other group of recipients that are characteristically identified by an identification number. The Bluetooth MAC address and WLAN MAC address identify devices that are associated with the potential recipient and are capable of communicating in either Bluetooth or WLAN short-range wireless communication. The instant message address and email address identify potential recipients according to their instant message or email address. Additionally, other potential recipient attributes may be stored at the network hub as dictated by the application. FIG. 6 illustrates a flow diagram of an overall network hub process for message receipt, prioritizing generic-recipient messages and message dispatch, in accordance with an embodiment of the present invention. At step 700, the network hub receives a message from a communication network. The communication network may include a cellular telephone network, a SMS network, a MMS network, an email network or the like. At step 710, the message priority application is executed to determine if the message requires priority. Determination of message priority will entail comparing attributes of the message to a listing of attributes requiring priority. For example, the network hub may be configured to provide priority to generic-recipient messages sent from a particular sender or messages having specific content. In addition, to determining whether a message requires prioritization, the application will determine the type of prioritization required. For example, messages from a particular sender may require display prioritization or messages having specific content may require dispatch prioritization. In the example provided by the flow diagram of FIG. 6, the priority that is determined is display priority. As such, if the message priority application determines that the message requires display priority then, at step 720, the message is provided display priority, in this instance display priority is defined by displaying the assigned message first amongst a listing of messages. Typically, the priority message will remain at or near the first position in the listing as subsequent messages are received and added to the listing, dependent upon how many subsequent messages are also prioritized messages. If the message priority application determines that the message does not require display priority then, at step 730, the message is displayed at the relevant position in the display list. The relevant position may be the first position in the listing if no priority messages currently exist in the listing or the relevant position may be the first position in the listing after the listing of all priority messages. Alternatively, priority may be determined manually, by a network hub administrator. In such instances, the network hub administrator uses application information, message information, potential recipient information and other related information to determine message priority. At step 740, the message recipient determination and dispatch application is executed to determine the recipients of the message and to dispatch the message to the determined recipients. The message recipient determination and dispatch application compares predefined attributes of the generic-recipient message to stored information related to potential recipients to determine one or more recipients for the generic-recipient messages. Dispatch of the assigned messages may be accomplished by various message dispatch means. For example, dispatch may be accomplished by short-range wireless communication, whereby recipient RFID identifiers associated with messages and the message are dispatched when the recipients RFID tag is placed in close proximity to the network hub. In other examples, dispatch of the message may be accomplished by transmitting email, voice mail, SMS, MMS or some other form of network communication. Alternatively, recipient determination may be conducted manually, by a network hub administrator. In such instances, the network hub administrator uses message information, potential recipient information and other related information to determine the recipient(s) of the message. Once determination of the recipient is made, the recipient will typically be identified on the associated display, if the hub utilizes an associated display for message dispatch. Alternatively, the method may determine the recipient prior to display of the message, such that, upon determination of the recipient the message or message identifier along with the determined recipients are displayed. At step 750, the process determines whether the dispatched message has been acknowledged by the one or more recipients. Acknowledgement by the recipient insures that the determined recipient has received and acknowledged the message (i.e., read the message or performed the task required of the message). If no acknowledgement is received the network hub either continues to wait for acknowledgement or returns to the message recipient determination and dispatch application step 740. In some embodiments of the invention if the network hub does not receive an acknowledgement within a predefined period of time, the network hub will either dispatch the message to a next-in-line recipient or re-execute the message recipient determination and dispatch application to determine a next-in-line recipient. If the network hub receives an acknowledgement then, at step 760, the address will deleted from the network hub according to applicable deletion logic. Alternatively, the dispatched and acknowledged message may be stored at the network hub for a predefined period of time. FIGS. 5A and 5B depict flow diagrams of alternate methods for dispatching generic-recipient messages, in accordance with embodiments of the present invention. The methods differ by the means in which the recipients of the generic-recipient messages are determined. In the FIG. 7A embodiment the determination of recipient(s) is conducted manually, at step 800, typically by a network hub administrator who relies on information in the generic-recipient messages, information related to potential recipients and potential recipients availability to determine one or more recipients. In the FIG. 7B embodiment the determination of recipient(s) is conducted, at step 810, by executing a message recipient determination and dispatch application at the network hub. The message recipient determination and dispatch application will compare predefined attributes of the message with predefined attributes of potential recipients to determine one or more message recipients. Steps 820-850 are characteristic of a network hub that implements short-range wireless communication as the predominate means of dispatching messages. In alternate embodiments of the network hub, other means of dispatch, such as email. SMS, voice mail or the like, may be the predominate chosen means of dispatching messages. At step 820, the network hub makes the determination of whether the recipient's short-range wireless tag is within range to receive short-range wireless communication. If the tag is within range then, at step 830, the network hub will implement Bluetooth, WLAN or some other form of short-range wireless communication to dispatch the message to the determined recipient(s). If the tag is not within range then, at step 840, the network hub will implement email, voice mail, SMS, MMS or some other form of messaging to dispatch the message to the determined recipient(s). At step 850, once the message has been dispatched, the network hub will mark the messages as dispatched. FIG. 8 illustrates a flow diagram of a method for message dispatch in accordance with an embodiment of the present invention. The method of FIG. 8 implements low power, short-range wireless communication to dispatch messages. As noted previously in the detailed discussion, the invention may also utilize other methods of dispatch, such as email, voice mail, SMS or the like, without departing from the inventive concepts herein disclosed. At step 900, a potential recipient of messages swipes an RFID tag at the network hub device or at the associated display of the network hub device. In the instance in which the network hub has an associated display, the potential recipient may be aware that a message is intended for their dispatch by visual representation on the display. At step 910, the network hub determines if the swiped tag is a new tag and, if it is a new tag, adds the potential recipient and the associated tag to the database of potential recipients. At step 920, the network hub makes the determination of whether the recipient's short-range wireless tag is within range to receive short-range wireless communication. If the tag is within range then, at step 930, the network hub will implement Bluetooth, WLAN or some other form of short-range wireless communication to dispatch the message to the determined recipient(s). If the tag is not within range then, at step 940, the network hub will implement email, voice mail, SMS, MMS or some other form of messaging to dispatch the message to the determined recipient(s). At step 950, once the message has been dispatched, the network hub will mark the messages as dispatched. In this regard, FIGS. 6-8 provide for methods, systems and program products according to the invention. It will be understood that each block or step of the flowcharts, and combinations of blocks in the flowcharts, can be implemented by computer program instructions. These computer program instructions may be loaded onto a computer or other programmable apparatus to produce a machine, such that the instructions which execute on the computer or other programmable apparatus create means for implementing the functions specified in the flowchart block(s) or step(s). These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart block(s) or step(s). The computer program instructions may also be loaded onto a computer or other programmable apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block(s) or step(s). Accordingly, blocks or steps of the flowcharts support combinations of means for performing the specified functions, combinations of steps for performing the specified functions and program instruction means for performing the specified functions. It will also be understood that each block or step of the flowchart, and combinations of blocks or steps in the flowchart, can be implemented by special purpose hardware-based computer systems that perform the specified functions or steps, or combinations of special purpose hardware and computer instructions. Therefore, the present invention provides for devices, methods and computer program products for automatically determining recipients of generic-recipient messages, dispatching generic-recipient messages to proper recipients and prioritizing the dispatch of generic-recipient messages. The device and methods function without an expensive private telephone network or a central system for short incoming text or voice communication. In addition, the device and methods are generally automatic and, thus, require minimal manual intervention by system administrators. Further, the devices and methods are capable of supporting both local and remote message dispatching so as to optimize the system and achieve a lowest cost alternative. In addition, the devices and methods of the present invention dispatch of messages over various communication means, such as short-range wireless, Internet, cellular networks and the like. The devices and methods also provide for multiple priority schemes, such that priority can be given to generic-recipient messages depending on the communication network used to dispatch the message. Additionally, the priority system and methods should be automated to allow for message priority to be determined with minimal manual intervention by system administrators. Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the cope of the appended claims. Although specific terms are employed herein, they are used in a generic-recipient and descriptive sense only and not for purposes of limitation. | <SOH> BACKGROUND OF THE INVENTION <EOH>In today's business environment an individual receives digital messages from various sources and by various communication means. For example, an individual may receive messages from a fellow employee, from a customer, from a supplier or from any other relevant business contact. The sender of message may be internally located at the same worksite as the individual receipt, as typically is the case with fellow employees, or may be externally located outside of the workplace, as typically is the case with customers or suppliers. In addition to the variance in message source, digital messages are communicated to individuals by various digital means, such as electronic mail, voice mail, Short Message Service (SMS) communication, Multimedia Message Service (MMS) communication and the like. Moreover, the recipient of these messages is provided multiple means for receiving the messages. For example, email accounts can be accessed from a personal computer, a wired or wireless laptop computer, a wireless Personal Digital Assistant (PDA), a wireless cellular telephone or any other conceivable wired or wireless device capable of digital communication. Even voice mail, once limited to access via the wired or wireless telephone, can now be accessed via the personal computer, laptop computer, PDA or the like. The vast majority of the digital messaging communication is conducted on a person-to-person basis. For example, one individual sends another individual an email or an SMS communication or one individual initiates a cellular telephone call to another individual. Much more limited are the communication options for person-to-group, person-community, person-to-place or person-to-application communication. This type of communication is also referred to herein as generic-recipient message, in which the user does not send the message to a specific individual but rather to a group, a community, a location or an application. Email allows an individual to send a group email to multiple recipients; however, in this regard the user forms the group email address from a collection of known individual email addresses. In practice, the group email provides person-to-person communication to multiple recipients. The group email communication does not allow the sender to send an email correspondence to a group if the sender is unaware of the individuals that form the group. The concept of generic-recipient messaging is best explained by providing examples. An individual wishes to contact Company X and inquire about the status of a particular product that they recently ordered from Company X. The individual wishes to communicate via email. Unless the individual is aware of the specific individual within Company X that is handling this order, email communication can become somewhat problematic. Typically, the individual's only email option is to send an email correspondence to a generic Company X email address and have a system administrator manually dispatch the email to a perceived intended recipient. Thus, the sender of the email is provided very little assurance that the email will be dispatched to the proper entity handling the order. In many of these instances, the individual's email is dispatched to the incorrect recipient and, thus, the individual never receives an appropriate reply. This same dilemma presents itself in the example of an individual trying to contact Company X via telephone communication to status an outstanding order. The individual is unaware of the direct line telephone number of the individual handling the account and, thus, the only option presented to the individual is to contact Company X's main switchboard and either ask for a specific department or explain to the main switchboard operator the question at hand. All too often the switchboard operator will dispatch the call to the incorrect recipient, thus, frustrating the individual who is trying to status an outstanding order. In other instances, the switchboard operator is unaware of whether a recipient is available to receive the call and will invariably lead the individual caller into the unavailable recipient's voice mail system. In the same regard, automated key-tone or voice command systems, which obviate the need for a switchboard operator, are often cumbersome and confusing to the user and provide even greater opportunity to dispatch the call to an incorrect recipient. In addition to properly dispatching these generic-recipient messages to proper recipients, a need exists to identify and prioritize the dispatch of generic-recipient messages that require priority dispatching. For example, in the email scenario the sender of the email may emphasize the messages importance by flagging the message or otherwise highlighting the subject header or contents or the message. However, if the sender of the email fails to designate the message as a priority message, it is unlike that the system administrator who dispatches the message will recognize the importance and subjectively provide for the requisite higher priority. Additionally, even in the instance in which the system administrator receives a message marked by the sender as requiring priority, manual dispatch provides no assurance that the priority will be forwarded to the determined recipient upon dispatch. Therefore, a need exists to develop a system and methods for dispatching generic-recipient messages to proper recipients. The desired system should function without an expensive private telephone network or a central system for short incoming text, graphic or voice communication. In addition, the desired dispatch system should be generally automatic and, thus, require minimal manual intervention by system administrators. The desired system and method should be capable of supporting both local and remote generic-recipient message dispatching so as to achieve a lowest cost alternative. In addition, the desired system and method should support the dispatch of generic-recipient messages over various communication means, such as short-range wireless, Internet, cellular networks and the like. A need also exists to develop a system and methods for providing dispatch priority to generic-recipient messages. The desired system should provide for multiple priority schemes, such that priority can be given to generic-recipient messages depending on the communication network used to dispatch the message. Additionally, the priority system and methods should be automated to allow for message priority to be determined with minimal manual intervention by system administrators. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>The present invention provides for devices, methods and computer program products for dispatching generic-recipient messages to determined recipients and for prioritizing the dispatch of generic-recipient messages. The invention utilizes a network hub device that receives generic-recipient messages and executes a dispatch application to determine one or more recipients. The system functions without an expensive private telephone network or a central system for short incoming text or voice communication. The generally automatic nature of the dispatch application provides for minimal manual intervention by system administrators. In addition, the network hub is typically located within the network such that it is capable of supporting both local and remote message dispatching. The network hub device and associated methods support dispatch of generic-recipient messages over various communication means, such as short-range wireless, Internet, cellular networks and the like. In one embodiment, the network hub is associated with a display device, such that received generic-recipient messages can be prominently displayed to potential recipients prior to dispatch via short-range wireless communication. In addition, the network hub device may be a wireless device to provide for physical portability of the hub. Additionally the network hub and related methods may execute a dispatch priority application that automatically attaches dispatch priority to messages based on predefined priority attributes. Multiple priority schemes are feasible to accommodate for the communication network used to dispatch the message. For example, a message that will be prominently displayed prior to dispatch may be granted display priority or priority may be defined by the communication network used to dispatch a message. The invention may be defined by a method for determining a recipient of a generic-recipient message and dispatching the message to the determined recipient. The method includes the steps of receiving a message at a network hub, determining predefined attributes of the received message, determining the recipients for the message based upon the predefined attributes and dispatching the message to the determined recipients. The message may be a Short Message Service (SMS) message, a Multimedia Message Service (MMS) message, an electronic mail (email) message, a voice message or the like. The network hub will typically be a wireless network hub, although a wired network hub is also within the concepts of the present invention. The predefined attributes of the message may include the type of message (i.e., SMS, MMS, email, voice, etc.), the sender of the message, the subject of the message and the content of the message. The step of determining the recipients for the message based upon the predefined attributes may further include the step of correlating the predefined attributes of the message with stored information related to potential recipients. The step of dispatching the message to the determined recipients may further include the step of assigning recipient Radio Frequency (RF) identifiers to the message. In this regard, message recipients may receive the message by communicating with the network hub via an RF tag and corresponding RF reader. Additionally, the step of dispatching the message to the determined recipients may further include the step of displaying the message on a display associated with the network hub. By displaying the messages on a display potential recipients can view, at least a portion of, the message such as the subject header and determine if they are the determined recipient of the message. If a potential recipient determines that they are the intended recipient they may receive the message by short-range wireless communication techniques, such as RFID communication or the like. The dispatching of the message to the determined recipients may involve transmitting the message to the determined recipients via a standard communication medium, such as short-range wireless communication, Internet communication, SMS communication, MMS communication or the like. In a further embodiment of the invention a network hub device for determining recipients of generic-recipient messages and dispatching the to determined recipients is defined. The network hub device includes a processing unit and a memory unit in communication with the processing unit that stores information related to the potential recipients. Additionally, the network hub includes a message reception application executed by the processing unit that receives generic-recipient messages from various communication networks and determines predefined attributes of received messages. The network hub also includes a message recipient determination and dispatch application executed by the processing unit that compares the predefined attributes to the information related to the potential recipients to determine the recipients. The network hub may further include a Radio Frequency (RF) transceiver for dispatching assigned messages to determined recipients via lower power RF communication. Additionally, the network hub may include a Global System for Mobile communications (GSM) application for dispatching messages to determined recipients via a digital cellular network or a similar communication network application, such as an Internet application, a Short Message Service (SMS) application, a Multimedia Message Service (MMS) application or the like. The network hub device may also include an associated display that visually displays, at least a portion of, the message. By displaying the assigned messages on a display potential recipients can view the message and determine if they are the intended recipients of the message. If a potential recipient determines that they are the intended recipient they may receive the message by short-range wireless communication techniques, such as RFID communication or the like. In yet another embodiment of the invention a computer program product is described for automatically determining recipients of generic-recipient messages. The computer program product includes a computer readable storage medium having computer-readable program instructions embodied in the medium. The computer-readable program instructions include first instructions for storing information related to potential message recipients and second instructions for receiving a message at a network hub, typically a wireless network hub, and determining predefined attributes associated with the message. The message may include any conventional digital message such as, a Short Message Service (SMS) message, a Multimedia Message Service (MMS) message, an electronic mail (email) message and a voice message. The predefined attributes associated with the message may include the type of message, sender of the message, subject of the message and content of the message. Additionally, the computer-readable program instructions includes third instructions for determining the message recipients of the message by comparing the predefined attributes associated with the messages to the stored information related to potential message recipients. The computer-readable program instructions may further include fourth instructions for dispatching the message to the determined message recipient(s). Dispatching may involve communicating the messages via short-range wireless communication, wired or wireless Internet communication, SMS communication, MMS communication or the like. Dispatching may include the step of assigning recipient Radio Frequency (RF) identifiers to the message. In this regard, a transponder within the network hub may communicate via RF with tags in the possession of the recipients. Additionally, dispatching may include displaying, at least a portion of the message on a display associated with the network hub, so that intended recipients are visually aware that messages are designated for their receipt. The invention is further defined by a method for prioritizing generic-recipient messages at a network hub. The method includes the steps of receiving a message at a network hub, determining predefined attributes of the received message, determining whether the message has priority based on the predefined attributes and prioritizing the message if a determination is made that the message has priority. The generic-recipient messages will typically include various message formats including SMS, MMS, email and voice message. The network hub will typically be a wireless network hub, however; a wired network hub is also possible. The step of determining whether the message has priority based on the predefined attributes may further include determining whether the message has display priority based on the predefined attributes. Display priority may take the form of displaying the prioritized message in a prominent position on a display associated with the hub, create a pop-up type window for the display of the prioritized message or otherwise highlighting the display of the prioritized message. Additionally, the step of determining whether the message has priority based on the predefined attributes may further include determining whether the message has dispatch priority based on the predefined attributes. Dispatch priority may take the form of prioritized the communication medium used to dispatch the message, prioritizing a sequence of recipients to whom the message may be dispatched, prioritizing the time of dispatch and the like. The step of determining predefined attributes of the group-addresses message may define the predefined attributes as the type of message, the sender of the message, the subject of the message, the content of the message or any other message attribute may be included as a predefined parameter. The invention is also embodied in a network hub device for prioritizing generic-recipient messages. The network hub device includes a processing unit, a memory unit in communication with the processing unit that stores priority information, a message reception application executed by the processing unit that receives generic-recipient messages from one or more communication networks and determines predefined attributes of received generic-recipient messages. The network hub also includes a message priority application executed by the processing unit that compares the predefined attributes to the priority information to determine if the received message requires prioritization. The predefined attributes will typically include attributes defined in the message, such as a sender of the message, a type of the message, a subject of the message, the content of the message and the like. Prioritization may be defined as display prioritization or dispatch prioritization. In network hubs that define priority in terms of display priority, the memory unit will store display priority information and the message priority application will compare the predefined attributes to the display priority information to determine if the received message requires display prioritization. In those embodiments that implement display priority, the network hub may include a display associated with the hub that displays the messages. Display prioritization may take the form of listing prioritized messages first, displaying prioritized messages in a pop-up style window or otherwise highlighting the display of the prioritized message. In network hubs that define priority in terms of dispatch priority, the memory unit will store dispatch priority information and the message priority application will compare the predefined attributes to the dispatch priority information to determine if the received message requires dispatch prioritization. Dispatch priority may take the form of prioritizing the time at which messages are dispatched, the communication medium used to dispatch the message or a priority sequence of whom the message will be dispatched to. In yet another embodiment of the invention a computer program product is described for prioritizing generic-recipient messages at a network hub. The computer program product includes a computer readable storage medium having computer-readable program instructions embodied in the medium. The computer-readable program instructions include first instructions for first instructions for storing information related to message priority and second instructions for receiving a message at a network hub and determining predefined attributes associated with the message. The group message priority information may be display priority information or dispatch priority information. The message may include any conventional digital message such as, a Short Message Service (SMS) message, a Multimedia Message Service (MMS) message, an electronic mail (email) message and a voice message. The predefined attributes associated with the message may include the type of message, sender of the message, subject of the message and content of the message. Additionally, the computer-readable program instructions includes third instructions for determining whether the message has priority by comparing the predefined attributes associated with the generic-recipient messages to the stored information related to message priority. Therefore, the present invention provides for devices, methods and computer program products for determining a recipient for a generic-recipient message, dispatching the generic-recipient message to determined recipients and prioritizing the dispatch of the generic-recipient message. The device and methods function without an expensive private telephone network or a central system for short incoming text or voice communication. In addition, the device and methods are generally automatic and, thus, require minimal manual intervention by system administrators. Further, the devices and methods are capable of supporting both local and remote message dispatching so as to optimize the system and achieve a lowest cost alternative. In addition, the devices and methods of the present invention dispatch generic-recipient messages over various communication means, such as short-range wireless, Internet, cellular networks and the like. The devices and methods also provide for multiple priority schemes, such that priority can be given to messages depending on the communication network used to dispatch the message. Additionally, the priority system and methods should be automated to allow for message priority to be determined with minimal manual intervention by system administrators. | 20040223 | 20171219 | 20050908 | 66527.0 | 0 | JAKOVAC, RYAN J | Methods, apparatus and computer program products for dispatching and prioritizing communication of generic-recipient messages to recipients | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,784,604 | ACCEPTED | Compression apparatus | A compression apparatus including an expandable body configured for disposal about a foot. A strap extends from the body. The strap is configured for disposal about the foot adjacent an ankle. The strap has a first layer configured to engage an outer surface of the foot adjacent the ankle, a second layer and a third cushion layer disposed therebetween. The body may include a metatarsal portion. The first layer and the second layer may be configured to provide a barrier to the third cushion layer. The first layer may be configured to prevent engagement of the third cushion layer with the outer surface of the foot. | 1. A compression apparatus comprising: an expandable body configured for disposal about a foot; a strap extending from the body, the strap being configured for disposal about the foot adjacent an ankle, wherein the strap has a first layer configured to engage an outer surface of the foot adjacent the ankle, a second layer and a third cushion layer disposed therebetween. 2. A compression apparatus as recited in claim 1, wherein the strap is integrally connected to the body. 3. A compression apparatus as recited in claim 1, wherein the strap is monolithically formed with the body. 4. A compression apparatus as recited in claim 1, wherein the body includes the first layer. 5. A compression apparatus as recited in claim 4, wherein the body includes the second layer. 6. A compression apparatus as recited in claim 1, wherein the strap has a segmented configuration for contour with the foot. 7. A compression apparatus as recited in claim 1, wherein the third cushion layer is disposed within the first layer and the second layer such that the first layer and the second layer are configured to provide a barrier to the third cushion layer. 8. A compression apparatus as recited in claim 1, wherein the body includes a metatarsal strap. 9. A compression apparatus as recited in claim 1, wherein the first layer includes a soft material. 10. A compression apparatus as recited in claim 1, wherein the first layer includes a soft material and a flexible film. 11. A compression apparatus as recited in claim 1, wherein the third cushion layer includes a foam material. 12. A compression apparatus as recited in claim 1, wherein the second layer has an outer surface including a loop material disposed therewith. 13. A compression apparatus as recited in claim 1, wherein the second layer includes a flexible film and an outer surface having a loop material disposed therewith. 14. A compression apparatus as recited in claim 8, wherein the second layer has an outer surface including a loop material such that the metatarsal strap includes hook elements that are engageable with the loop material to mount the expandable body with the foot. 15. A compression apparatus as recited in claim 12, wherein the body includes hook elements that are engageable with the loop material to mount the expandable body with the foot. 16. A compression apparatus comprising: a foot sleeve including an inflatable body configured for disposal about a foot, the foot sleeve including a metatarsal portion; a strap integrally connected to the foot sleeve and extending therefrom, the strap being configured for disposal about the foot adjacent an ankle, wherein the strap has a first layer configured to engage an outer surface of the foot adjacent the ankle, a second layer and a third cushion layer disposed therebetween such that the first layer and the second layer are configured to provide a barrier to the third cushion layer. 17. A compression apparatus as recited in claim 16, wherein the first layer is configured to prevent engagement of the third cushion layer with the outer surface of the foot. 18. A compression apparatus as recited in claim 16, wherein the third cushion layer includes a foam material. 19. A compression apparatus as recited in claim 16, wherein the strap has a segmented configuration for contour with the foot. 20. A compression apparatus comprising: a foot sleeve including an inflatable bladder configured for disposal about a foot, the foot sleeve including a metatarsal portion that overlies the foot; a strap integrally connected to the foot sleeve and extending therefrom, the strap being configured for disposal about the foot adjacent an ankle, wherein the strap has a foot contact layer including a soft material that is configured to engage an outer surface of the foot adjacent the ankle, an outer layer and a cushion layer including foam material disposed therebetween such that the foot contact layer and the outer layer are configured to provide a barrier to the cushion layer, the outer layer having an outer surface including a loop material such that the metatarsal portion includes hook elements that are engageable with the loop material to mount the foot sleeve with the foot. 21. A compression apparatus as recited in claim 1, wherein the compression apparatus includes a plurality of straps extending from the body. 22. A compression apparatus comprising: an expandable body configured for disposal about a foot, the expandable body including a top layer and a bottom layer; and a strap member extending from the expandable body, wherein a portion of the strap member is disposed between the top and bottom layers of the expandable body. 23. A compression apparatus as recited in claim 22, wherein the strap member includes a plurality of layers, whereby the plurality of layers comprises an interiorly disposed cushion layer. | BACKGROUND 1. Technical Field The present disclosure generally relates to the field of vascular therapy for application to a limb of a body, and more particularly, to a compression apparatus configured to artificially stimulate blood vessels of the limb. 2. Description of the Related Art A major concern for immobile patients and persons alike are medical conditions that form clots in the blood, such as, deep vein thrombosis (DVT) and peripheral edema. Such patients and persons include those undergoing surgery, anesthesia and extended periods of bed rest. These blood clotting conditions generally occur in the deep veins of the lower extremities and/or pelvis. These veins, such as the iliac, femoral, popiteal and tibial return deoxygenated to the heart. For example, when blood circulation in these veins is retarded due to illness, injury or inactivity, there is a tendency for blood to accumulate or pool. A static pool of blood is ideal for clot formations. A major risk associated with this condition is interference with cardiovascular circulation. Most seriously, a fragment of the blood clot can break loose and migrate. A pulmonary emboli can form blocking a main pulmonary artery, which may be life threatening. The conditions and resulting risks associated with patient immobility may be controlled or alleviated by applying intermittent pressure to a patient's limb, such as, for example, portions of a leg and foot to assist in blood circulation. Known devices have been employed to assist in blood circulation, such as, one piece pads and compression boots. See, for example, U.S. Pat. Nos. 4,696,289 and 5,989,204. Compression devices that consist of an air pump connected to a disposable wraparound pad by one or more air tubes have been used. The wraparound pad is placed around the patient's foot or other extremity. Air is then forced into the wraparound pad creating pressure around the parts of the foot or other extremity. These known devices may suffer from various drawbacks due to their bulk, cumbersome nature of use, potential for contamination and irritation to the extremity during application and use. These drawbacks reduce comfort, compliance, cause skin breakdown and may disadvantageously prevent mobility of the patient as recovery progresses after surgery. Therefore, it would be desirable to overcome the disadvantages and drawbacks of the prior art with a foot sleeve that prevents contamination, mitigates the incidence of skin breakdown and facilitates disposal with an extremity. It is contemplated that a compression apparatus including the foot sleeve reduces bulk and is not cumbersome during use to improve comfort and compliance to a patient. It is further contemplated that the compression apparatus is easily and efficiently manufactured. SUMMARY Accordingly, a compression apparatus is provided that prevents contamination, mitigates the incidence of skin breakdown and facilitates disposal with an extremity for overcoming the disadvantages and drawbacks of the prior art. Desirably, a compression apparatus including the foot sleeve reduces bulk and is not cumbersome during use to improve comfort and compliance to a patient. The compression apparatus is easily and efficiently fabricated. The embodiments of the compression apparatus, according to the present disclosure, are configured to provide vascular therapy, including for example the prevention of deep vein thrombosis (“DVT”) by artificially stimulating blood vessels throughout the foot of a patient, including the toes and the heel, to increase blood circulation for patients. The compression apparatus according to the present disclosure is an intermittent pneumatic compression device for applying slow compression to a foot. Such pressure simulates blood flow that would normally result from, for example, walking, by employing a foot sleeve that is supported about a foot of a patient. The compression apparatus may have an inflatable bladder designed to cover and engage the entire area of the bottom of the foot, beyond the heel and ball to a substantial portion of the toes. The inflatable bladder wraps about the side portions of the foot via a hook and loop type connector flap that transverses the instep of the foot. The inflatable bladder may include an outside layer and an inside layer. The bladder can be formed by welding the outside layer and the inside layer together. The bladder provides a uniform application of pressure to the entire foot and is then deflated. Moreover, the compression apparatus may include bladder sections that are capable of enabling venous refill detection. The compression apparatus according to the present disclosure includes various embodiments and combinations as will be appreciated herein. The various embodiments and combinations may each be manufactured in various sizes to accommodate subjects of varying sizes as well as right and left foot models. The compression apparatus includes a strap that improves comfort by using a single piece laminate structure whose inside layer is a cushioning layer. The strap is integrated with a foot sleeve by sandwiching the strap between separate layers of the foot sleeve body. The comfort to the patient may be improved by segmenting the strap to contour about the heel of the foot. The strap can also include one or more layers configured to provide a barrier to the cushioning layer from the environment. The foot sleeve can improve ease of use by having a universal design with a one flap metatarsal closure. The strap may include a laminate consisting of various layers. The layers may include a center layer that is configured for comfort. Outside layers disposed about the center layer provide a barrier between the environment and an outer surface of the foot. One of the outside layers can be a skin contact layer that is soft to the touch. The strap may be a separate part integrated into the body of the foot sleeve by being sandwiched between separate layers of the foot sleeve body and then permanently secured. The body of the foot sleeve may be designed for adaptability to various foot sizes and shapes by employing a single metatarsal flap that facilitates ease of use. The body may be configured to provide inspection of the tops of the phalanges of the foot. One of the advantages of the present disclosure is a cushioning layer that is not in direct engagement with the outer surface of the foot. The cushioning layer has a soft skin contact layer. The foot sleeve may also include a liner that is configured to provide a physical barrier to the cushioning layer that assists in the prevention of contamination. The interior cushioning layer provides comfort and mitigates skin breakdown. Thus, the foot sleeve improves patient compliance and provides sanitation by isolating the cushioning layer from the environment. The foot sleeve is also easily manufactured, for instance, the material stack up contained in the layers allows the strap and/or foot sleeve to be cut as one piece and ensures an even stack up of materials. In one embodiment, in accordance with the principles of the present disclosure, the compression apparatus includes an expandable body configured for disposal about a foot. A strap extends from the body. The strap is configured for disposal about the foot adjacent an ankle. The strap has a first layer configured to engage an outer surface of the foot adjacent the ankle, a second layer and a third cushion layer disposed therebetween. The strap may be integrally connected to the expandable body. Alternatively, the strap may be monolithically formed with the expandable body. The expandable body can include a first, top layer and/or a second, bottom layer. Moreover, a portion of the strap member may be disposed between a top and bottom layer of the foot sleeve body. The strap may have a segmented configuration for contour with the foot. The third cushion layer can be disposed within the first layer and the second layer such that the first layer and the second layer are configured to provide a barrier to the third cushion layer. The body can include a metatarsal strap. Alternatively, the first layer includes a soft polyester material. The first layer may include a soft polyester material and polyvinylchloride. The third cushion layer may include a foam material. The second layer can have an outer surface including a loop material disposed therewith. The second layer may include a polyvinylchloride material and an outer surface having a loop material disposed therewith. Alternatively, the second layer has an outer surface including a loop material such that the metatarsal strap includes hook elements that are engageable with the loop material to mount the compression apparatus with the foot. The body may include hook elements that are engageable with the loop material to mount the compression apparatus with the foot. In an alternate embodiment, the compression apparatus has a foot sleeve including an inflatable body configured for disposal about a foot. The foot sleeve includes a metatarsal portion. A strap is integrally connected to the foot sleeve and extends therefrom. The strap is configured for disposal about the foot adjacent an ankle. The strap has a first layer configured to engage an outer surface of the foot adjacent the ankle, a second layer and a third cushion layer is disposed therebetween. The first layer and the second layer are configured to provide a barrier to the third cushion layer. The first layer may be configured to prevent engagement of the third cushion layer with the outer surface of the foot. BRIEF DESCRIPTION OF THE DRAWINGS The objects and features of the present disclosure, which are believed to be novel, are set forth with particularity in the appended claims. The present disclosure, both as to its organization and manner of operation, together with further objectives and advantages, may be best understood by reference to the following description, taken in connection with the accompanying drawings, which are described below. FIG. 1 is a plan view of one particular embodiment of a compression apparatus and showing an inflatable bladder and a foot in phantom, in accordance with the principles of the present disclosure; FIG. 1A is a partial cross-sectional view of the compression apparatus shown in FIG. 1; FIG. 2 is a cutaway cross section view of a strap of the compression apparatus shown in FIG. 1; FIG. 3 is a cutaway cross section view of an alternate embodiment of the strap of the compression apparatus shown in FIG. 1; FIG. 4 is a plan view of an alternate embodiment of the compression apparatus shown in FIG. 1, illustrating an inflatable bladder in phantom; FIG. 5 is a plan view of another alternate embodiment of the compression apparatus shown in FIG. 1, illustrating an inflatable bladder in phantom; FIG. 6 is a plan view of another alternate embodiment of the compression apparatus shown in FIG. 1, illustrating an inflatable bladder in phantom; and FIG. 7 is a plan view of another alternate embodiment of the compression apparatus shown in FIG. 1, illustrating an inflatable bladder in phantom. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS The exemplary embodiments of the compression apparatus including the foot sleeve and methods of operation disclosed are discussed in terms of vascular therapy including a compression apparatus for application to a foot or other limb of a body and more particularly in terms of a compression apparatus configured to artificially stimulate the blood vessels of the limb including the foot, heel and toes of a patient. It is contemplated that the compression apparatus may be employed for preventing and overcoming the risks associated with patient immobility. It is further contemplated that the compression apparatus alleviates the conditions arising from patient immobility to prevent for example, DVT, and peripheral edema. It is contemplated that the compression apparatus according to the present disclosure may be employed with various types of venous compression systems, including, but not limited to rapid inflation, slow compression, non-sequential and sequential compression apparatus. It is envisioned that the present disclosure, however, finds application with a wide variety of immobile conditions of persons and patients alike, such as, for example, those undergoing surgery, anesthesia, extended periods of bed rest, obesity, advanced age, malignancy, and prior thromboembolism. In the discussion that follows, the term “subject” refers to a patient undergoing vascular therapy using the compression apparatus. The following discussion includes a description of the compression apparatus, followed by a description of an exemplary method of operating the compression apparatus in accordance with the principals of the present disclosure. Reference will now be made in detail to the exemplary embodiments and disclosure, which are illustrated with the accompanying figures. Turning now to the figures, wherein like components are designated by like reference numerals throughout the several views. Referring initially to FIGS. 1, 1A and 2, there is illustrated a compression apparatus 10, constructed in accordance with the principals of the present disclosure (see, for example, the compression sleeve described in U.S. patent application Ser. No. ______, filed on Feb. 23, 2004 and entitled Compression Apparatus, the entire contents of which is hereby incorporated by reference herein). Compression apparatus 10 includes an expandable body, such as, for example, a foot sleeve 12 configured for disposal about a foot F of a subject (not shown). Foot sleeve 12 may be disposed with the right or left foot of the subject. Foot sleeve 12 fluidly communicates with a pressurized fluid source 14 via tubing 16 and a valve connector 18 (see, for example, the valve connector described in U.S. patent application Ser. No. ______, filed on Feb. 23, 2004 and entitled Fluid Conduit Connector Apparatus, the entire contents of which is hereby incorporated by reference herein) for applying compression to the left foot and/or the right foot to provide vascular therapy to the subject and augment venous return. Compression apparatus 10 employs a controller 20 to regulate fluid pressure for vascular therapy. See, for example, the controller described in U.S. patent application Ser. No. ______, filed on Feb. 23, 2004 and entitled Compression Treatment System, the entire contents of which is hereby incorporated by reference herein. Pressurized fluid source 14 may include a pump and may be stationary or portable. It is contemplated that pressurized fluid source 14 may include the necessary electronics and computer software to carry out vascular therapy, in accordance with the principles of the present disclosure. Foot sleeve 12 is configured to apply vascular therapy to the entire area of the bottom of foot F, beyond a heel H and a ball B to a substantial portion of toes T. It is contemplated that foot sleeve 12 and other parts of compression apparatus 10 may be disposed, wrapped and mounted with various limbs and extremities of a subject's body, such as, for example, legs and arms. It is further contemplated that foot sleeve 12 or portions thereof may be disposable. It is envisioned that foot sleeve 12 may include flexible sections, such as, elastic or spandex materials to facilitate mobility of a limb during use. The components of strap 22 may be fabricated from materials suitable for compression vascular therapy such as, for example, films and fabrics, such as PVC (polyvinyl chloride) and PE (polyethylene). Strap 22 is configured for disposal about foot F adjacent to the ankle. Strap 22 is integrally connected to foot sleeve 12 and fixedly mounted between a foot contact layer 26 and an outer layer 28 of foot sleeve 12, as will be discussed. Strap 22 may be monolithically formed with foot sleeve 12, wherein at least a portion of the strap 22 is formed from the same contiguous material as a portion of the foot sleeve 12. By way of non-limiting example, foot contact layer 26 may be formed from the same contiguous material as foot contact layer 32 of foot sleeve 12. Strap 22 has segmented portions 24 that are configured to contour about heel H of foot F. It is contemplated that segmented portions 24 may be variously configured and dimensioned, such as, rounded or alternatively, strap 22 may have a uniform outer surface, such as, smooth. Strap 22 has a first layer, such as, for example, foot contact layer 26 that is configured to engage to an outer surface of foot F adjacent the ankle. Foot contact layer 26 includes a soft polyester material 26a that is soft for engaging the skin of the subject. This soft skin contact layer 26 advantageously provides comfort to the subject, prevents contamination and mitigates skin breakdown. Foot contact layer 26 may also include a PVC portion 26b disposed adjacent soft polyester material 26a. A second layer, such as, for example, outer layer 28 cooperates with foot contact layer 26 such that a third layer 30 is disposed therebetween. Third layer 30 includes a foam material to provide a cushioning effect to the subject. It is contemplated that layer 30 may include alternative materials that provide a cushioned configuration. Outer layer 28 includes a loop type material 28a disposed therewith, for engagement with a corresponding hook element of foot sleeve 12, and a PVC portion 28b disposed adjacent loop material 28a. Outer layer 28 advantageously prevents contamination of third cushion layer 30 from the environment, such as, for example, air, moisture and dirt. Foot contact layer 26 and outer layer 28 are configured to form a physical barrier to third cushion layer 30. This configuration advantageously provides comfort to the subject, as well as compliance, and prevents contamination of third cushioning layer 30. In an alternate embodiment, as shown in FIG. 3, strap 22 includes a laminate structure having a cushion layer 130 and a PVC portion 132 disposed adjacent thereto. An outer layer 134 is disposed adjacent PVC portion 132. Layer 134 may include a soft polyester material for engaging the outer surface of foot F, or alternatively, may include a loop material to prevent contamination of cushion layer 130 from the environment. Foot contact layer 26 and outer layer 28 are overlaid to form strap 22. Foot contact layer 26 and outer layer 28 are fixedly joined at seams adjacent corresponding perimeters thereof, to support the components of strap 22. The components of strap 22 may be bonded via welding, e.g., RF welding, adhesive, industrial strength double sided tape and the like. It is envisioned that only a portion of the foot contact layer 26 and outer layer 28 are joined. It is further envisioned that strap 22 includes a plurality of seams, disposed variously thereabout, that join foot contact layer 26 and outer layer 28. In an alternative embodiment and with reference to FIG. 1A, an exaggerated partial cross-sectional view of a strap member 22 and its union to foot sleeve 12 is shown. The strap member 22 is disposed between the foot contact layer 32 and outer layer 42 of foot sleeve 12 such that the union of strap 22 and foot sleeve 12 is generally uniform. Such uniformity provides additional comfort to the user of the foot sleeve 12. More particularly, foot contact layer 26 and outer layer 28 of strap 22 are joined to interior portions of foot contact layer 32 and outer layer 42 of foot sleeve 12. Alternatively, it is also contemplated that cushioning layer 30 may or may not be disposed between foot contact layer 32 and outer layer 42 of foot sleeve 12. Strap 22 has a longitudinally projecting configuration extending from foot sleeve 12 and is configured for disposal about portions of foot F adjacent the ankle. Strap 22 forms part of a hook and loop type connector. A hook element 33 is mounted to strap 22 at foot contact layer 26. As strap 22 is wrapped about the portions of foot F adjacent the ankle, hook element 33 engages the loop material of outer layer 42 of foot sleeve 12 to facilitate mounting of foot sleeve 12 with foot F. Alternative to hook and loop type elements, clips, adhesive and pins may be employed. Foot sleeve 12 includes a foot contact layer 32 configured to engage foot F for applying pressure thereto. Foot contact layer 32 has sections 35 and is flexible for conforming to the shape of foot F. It is envisioned that foot contact layer 32 may be fabricated from a polyester fabric. It is contemplated that foot contact layer 32 may be configured for wicking fluids such as, moisture and perspiration from an outer surface of foot F. Foot contact layer 32 may be treated chemically to enhance such wicking effect. Alternatively, foot contact layer 32 may be monolithically formed with foot contact layer 26 of strap 22. An inflatable bladder 34 of foot sleeve 12 includes an upper bladder layer 36 and a lower bladder layer 38 that are overlaid to form inflatable bladder 34. Upper bladder layer 36 engages foot contact layer 32 to facilitate application of pressure for vascular therapy to foot F. Upper bladder layer 36 and lower bladder layer 38 are fixedly joined via welding at seams along their perimeters to define inflatable bladder 34. It is contemplated that inflatable bladder 34 may include a plurality of seams, disposed variously thereabout, that join upper bladder layer 36 and lower bladder layer 38. It is further contemplated that the seams may be formed by adhesive, heat sealed and the like. Upper bladder layer 36 and lower bladder layer 38 may be fabricated from a laminated material, for example, a PVC material. It is contemplated that each bladder layer may have a thickness of approximately 6-15 mils. It is further contemplated that the PVC material may be laminated to a non-woven or woven material and is RF heat sealable. Upper bladder layer 36 and lower bladder layer 38 may be fabricated from two different thicknesses to provide directional inflation. It is envisioned that the overall dimensions and materials described throughout this disclosure are not limiting and that other dimensions and materials may be used. It is further envisioned that inflatable bladder 34 may define one or a plurality of expandable chambers. Inflatable bladder 34 extends along foot F to apply vascular therapy to the entire area of the bottom of foot F, beyond heel H and ball B to a substantial portion of toes T. It is contemplated that inflatable bladder 34 may have various geometric configurations, such as, circular, elliptical and rectangular. Inflatable bladder 34 includes an inlet port 40 that connects to tubing 16 to facilitate fluid communication with pressurized fluid source 14. An outer layer 42 of foot sleeve 12 is disposed adjacent to lower bladder layer 38. Outer layer 42 may be fabricated from a laminated material including fabric and a loop material, for example, a loop/non-woven laminate. Outer layer 42 provides an attachment surface for hook elements. Alternatively, outer layer 42 may be monolithically formed with outer layer 28 of strap 22. Outer layer 42 may include die cut holes to provide for a fluid inlet to pass through, such as inlet port 40. It is envisioned that outer layer 42 and other portions of foot sleeve 12 may include vent openings disposed variously thereabout to provide cooling to the subject and increase mobility during use. Foot contact layer 32 and outer layer 42 are overlaid to form foot sleeve 12. Foot contact layer 32 and outer layer 42 are fixedly joined at seams adjacent corresponding perimeters thereof, to support the components of foot sleeve 12. The components of foot sleeve 12 may be bonded via welding, e.g., RF welding, adhesive, industrial strength double sided tape and the like. It is envisioned that only a portion of the perimeters of foot contact layer 32 and outer layer 42 are joined. It is envisioned that foot sleeve 12 includes a plurality of seams, disposed variously thereabout, that join foot contact layer 32 and outer layer 42. The components of foot sleeve 12 may be fabricated from materials suitable for compression vascular therapy such as, for example, films and fabrics, such as PVC (polyvinyl chloride) and PE (polyethylene), depending on the particular vascular therapy application and/or preference. Semi-flexible and flexible fabrics, such as urethanes and silicones may also be used. Moreover, foot sleeve 12 may be fabricated from synthetic, natural, and non-woven materials of varying degrees of softness and pliability. One skilled in the art, however, will realize that other materials and fabrication methods suitable for assembly and manufacture, in accordance with the present disclosure, also would be appropriate. Foot sleeve 12 is configured to support inflatable bladder 34. Foot sleeve 12 extends laterally and is configured for disposal about foot F and mounting thereto. Foot sleeve 12 is disposed with foot F such that the top portion of toes T are visible for observation and inspection. A metatarsal flap 44 of foot sleeve 12 wraps about the side portions of foot F and transverses the instep of foot F during vascular therapy. Metatarsal flap 44 forms part of a hook and loop type connector. A hook element 46 is mounted to foot sleeve 12 at foot contact layer 32. As metatarsal flap 44 is wrapped about foot F, hook element 46 engages the loop material of outer layer 42 to facilitate mounting of foot sleeve 12 with foot F. In turn, this causes inflatable bladder 34 to be disposed about foot F for vascular therapy. This configuration of foot sleeve 12 advantageously engages foot F to augment circulation of vessels of the limb. It is contemplated that foot sleeve 12 may have various geometric configurations, such as, circular, elliptical, and rectangular. Alternative to hook and loop type elements, clips, adhesive, and pins may be employed. Compression apparatus 10, similar to that described above, is assembled and packaged for use. In operation, foot sleeve 12 of compression apparatus 10 is disposed about foot F and in fluid communication with pressurized fluid source 14, as discussed. Controller 20 regulates vascular therapy of compression apparatus 10 to a subject. Foot sleeve 12 applies compression to foot F to provide vascular therapy to the subject and augment venous return. It is envisioned that compression apparatus 10 may include inflatable sleeves for disposal about various portions of a subject's limb, such as for example, thigh, calf, ankle and that a second limb may be treated in alternate compression cycles with other sleeve(s). For example, during a selected compression cycle for controller 20, inflatable bladder 34 is slowly inflated for 5 seconds with air to a pressure, such as 130 mm Hg. This configuration provides vascular therapy to foot F and augments venous return. At the end of the inflation and hold, foot sleeve 12 is vented and inflatable bladder 34 is deflated. Other compression cycles and pressures are also contemplated. In an alternate embodiment, compression apparatus 10 performs venous refill time measurement. Venous refill time (VRT) measurement is an air plethysmographic technique that determines when the veins of a limb have completely refilled with blood following a compression cycle. See, for example, the venous refill time measurement described in U.S. Pat. No. 6,231,352 to Watson et al., the entire contents of which is hereby incorporated by reference herein. The VRT minimizes the amount of time that the blood remains stagnant inside the veins. The VRT is substituted for the default rest time between compression cycles. It is contemplated that the VRT technique and algorithm can be used for both leg sleeve and foot sleeve compression. The VRT measurement uses an air plethysmographic technique where a low pressure is applied to inflatable bladder 34. As the veins fill with blood, the pressure in inflatable bladder 34 increases until a plateau is reached. The time that it takes for the pressure to plateau is the VRT. If two sleeves are connected to controller 20, then the VRT is determined separately for each limb being compressed and the greater of the two measurements is used as the new vent time of the compression cycle. The VRT measurement for each sleeve is made as each particular sleeve reaches set pressure independently. However, the vent time is not updated until VRT measurements have been calculated for both sleeves. For example, compression apparatus 10 may employ the VRT measurement after the system initiates vascular therapy. Subsequently, after 30 minutes have elapsed, a VRT measurement will be taken on the next full inflation cycle. After foot sleeve 12 inflates, inflatable bladder 34 is vented down to zero. It is contemplated that a selected bladder pressure is monitored and the vent to the bladder is closed when the pressure falls to 5-7 mm Hg. If the pressure in the bladder is 5-7 mm Hg on a current cycle then a VRT measurement is taken. If the pressure in the bladder does not vent down to 5-7 mm Hg then the vent time will remain at its current value and another measurement will be made in 30 minutes. The VRT measurement algorithm determines when the pressure in inflatable bladder 34 plateaus after compression. The VRT measurement algorithm initiates with a time counter started from the end of the inflation cycle, which occurs after inflatable bladder 34 reaches 5-7 mm Hg (enough pressure to cause the bladder to remain in contact with the surface of the foot) and the venting is stopped. The VRT measurement initiates with the time counter started from the end of the inflation cycle. The pressure in inflatable bladder 34 is then monitored with a 10-second, moving sample window. The window moves in 1-second intervals. When the difference between the first and last values in the window is less than approximately 0.05-0.5 mm Hg, the curve has reached its plateau. The VRT measurement is considered done, and the time interval is determined. The end of the window is considered to be the point at which the venous system in the foot has refilled. The VRT measurement is considered erroneous if at any time during the measurement, the pressure in inflatable bladder 34 is below 2 mmHg, the calculation is discarded, and the old value of VRT is used. This may occur if there is a leak in the system. It is contemplated that if the pressure is greater than 20 mmHg at any time during the VRT measurement, the old value of the VRT is used. Referring to FIG. 4, an alternate embodiment of compression apparatus 10 is shown. Compression apparatus 10 includes a foot sleeve 212, similar to foot sleeve 12 described above with regard to FIGS. 1, 1A and 2, configured for disposal about foot F. A pair of straps 222, similar to strap 22 described above with regard to FIGS. 1, 1A and 2, extend from foot sleeve 212. Straps 222 are configured for disposal about foot F adjacent to the ankle. One or a plurality of straps 222 may be employed. Straps 222 have a longitudinally projecting configuration extending from foot sleeve 212 and are configured for disposal about portions of foot F adjacent the ankle. As discussed herein, it is contemplated that straps 222 may be separately or monolithically formed with foot sleeve 212. Straps 222 form part of hook and loop type connectors. Hook element 232 and loop element 232a are mounted to straps 222. As each of straps 222 are wrapped about the portions of foot F adjacent the ankle, hook element 232 engages loop material 232a to facilitate mounting of foot sleeve 212 with foot F. It is contemplated that hook elements 232, 232a may engage loop material disposed with an outer surface of foot sleeve 212 to facilitate mounting of foot sleeve 212 with foot F. An inflatable bladder 234, similar to bladder 34 described above with regard to FIGS. 1 and 2, extends longitudinally along foot F to apply vascular therapy to the entire area of the bottom of foot F, beyond heel H and ball B to a substantial portion of toes T. Inflatable bladder 234 includes an inlet port 240 that connects to tubing 16 to facilitate fluid communication with pressurized fluid source 14. Foot sleeve 212 is configured to support inflatable bladder 234. Foot sleeve 212 extends laterally and is configured for disposal about foot F and mounting thereto. Foot sleeve 212 is disposed with foot F such that the top portion of toes T are visible for observation and inspection. A pair of metatarsal flaps 244 extend laterally from foot sleeve 212 for wrapping about the side portions of foot F and transversing the instep of foot F during vascular therapy. Metatarsal flaps 244 form the hook and loop type connectors. Hook element 246 and loop element 246a are mounted to foot sleeve 212. As metatarsal flaps 244 are wrapped about foot F, hook element 246 engages to loop element 246a to engage the foot sleeve 212 to facilitate mounting of foot sleeve 212 with foot F. In turn, this causes inflatable bladder 234 to be disposed about foot F for vascular therapy. This configuration of foot sleeve 212 advantageously engages foot F to augment circulation of vessels of the limb. Foot sleeve 212 includes vent openings 250 disposed to provide cooling to the subject and increase mobility during use. Referring to FIG. 5, another alternate embodiment of compression apparatus 10 is shown. Compression apparatus 10 includes a foot sleeve 312, similar to those described above, configured for disposal about foot F. A strap 322, similar to those described above, extends from foot sleeve 312. An inflatable bladder 334, similar to those described above, extends longitudinally along foot F to apply vascular therapy to the entire area of the bottom of foot F, beyond heel H and ball B to a substantial portion of toes T. Inflatable bladder 334 includes side portions 336 that extend laterally therefrom to engage side portions of foot F during application of foot sleeve 312 with foot F. Foot sleeve 312 is configured to support inflatable bladder 334. Foot sleeve 312 extends laterally and is configured for disposal about foot F and mounting thereto. Foot sleeve 312 is disposed with foot F such that the top portion of toes T are visible for observation and inspection. A pair of metatarsal flaps 344 extend laterally from one side of foot sleeve 312 for wrapping about the side portions of foot F and transversing the instep of foot F during vascular therapy. Metatarsal flaps 344 form part of hook and loop type connectors. Hook elements 346, 346a are mounted to foot sleeve 312. As metatarsal flaps 344 are wrapped about foot F, hook elements 346, 346a engage the loop material of foot sleeve 312 to facilitate mounting of foot sleeve 312 with foot F. In turn, this causes inflatable bladder 334 to be disposed about foot F, including side portions 336 engaging the side portions of foot F, for vascular therapy. This configuration of foot sleeve 312 advantageously engages foot F to augment circulation of vessels of the limb. Referring to FIG. 6, another alternate embodiment of compression apparatus 10 is shown. Compression apparatus 10 includes a foot sleeve 412, similar to those described above, configured for disposal about foot F. A strap 422, similar to those described above, extends from foot sleeve 412. An inflatable bladder 434, similar to those described above, extends longitudinally along foot F to apply vascular therapy to the bottom of foot F, beyond heel H and ball B to a substantial portion of toes T. Foot sleeve 412 has wings 444 (similar to metatarsal flaps described above) and is configured to support inflatable bladder 434. Foot sleeve 412 extends laterally, via wings 444, and is configured for disposal about foot F and mounting thereto. Foot sleeve 412 is disposed with foot F such that the top portion of toes T are visible for observation and inspection. Wings 444 wrap about the side portions of foot F and transverse the instep of foot F during vascular therapy. Wings 444 form part of hook and loop type connectors. Hook element 446 and loop element 446a are mounted to wings 444. As wings 444 are wrapped about foot F, hook element 446 engages with loop element 446a to facilitate mounting of foot sleeve 412 with foot F. In turn, this causes inflatable bladder 434 to be disposed about foot F for vascular therapy. This configuration of foot sleeve 412 advantageously engages foot F to augment circulation of vessels of the limb. Referring to FIG. 7, another alternate embodiment of compression apparatus 10 is shown. Compression apparatus 10 includes a foot sleeve 512, similar to those described above, configured for disposal about foot F. A strap 522, similar to those described above, extends from foot sleeve 512. An inflatable bladder 534, similar to those described above, extends longitudinally along foot F to apply vascular therapy to the bottom of foot F, beyond heel H and ball B to a substantial portion of toes T. Inflatable bladder 534 includes longitudinal portions 536 that extend longitudinally therefrom to engage desired portions of the bottom of foot F during application of foot sleeve 512 with foot F. Foot sleeve 512 is configured to support inflatable bladder 534. This configuration of foot sleeve 512 advantageously engages foot F to augment circulation of vessels of the limb. It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplification of the various embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto. | <SOH> BACKGROUND <EOH>1. Technical Field The present disclosure generally relates to the field of vascular therapy for application to a limb of a body, and more particularly, to a compression apparatus configured to artificially stimulate blood vessels of the limb. 2. Description of the Related Art A major concern for immobile patients and persons alike are medical conditions that form clots in the blood, such as, deep vein thrombosis (DVT) and peripheral edema. Such patients and persons include those undergoing surgery, anesthesia and extended periods of bed rest. These blood clotting conditions generally occur in the deep veins of the lower extremities and/or pelvis. These veins, such as the iliac, femoral, popiteal and tibial return deoxygenated to the heart. For example, when blood circulation in these veins is retarded due to illness, injury or inactivity, there is a tendency for blood to accumulate or pool. A static pool of blood is ideal for clot formations. A major risk associated with this condition is interference with cardiovascular circulation. Most seriously, a fragment of the blood clot can break loose and migrate. A pulmonary emboli can form blocking a main pulmonary artery, which may be life threatening. The conditions and resulting risks associated with patient immobility may be controlled or alleviated by applying intermittent pressure to a patient's limb, such as, for example, portions of a leg and foot to assist in blood circulation. Known devices have been employed to assist in blood circulation, such as, one piece pads and compression boots. See, for example, U.S. Pat. Nos. 4,696,289 and 5,989,204. Compression devices that consist of an air pump connected to a disposable wraparound pad by one or more air tubes have been used. The wraparound pad is placed around the patient's foot or other extremity. Air is then forced into the wraparound pad creating pressure around the parts of the foot or other extremity. These known devices may suffer from various drawbacks due to their bulk, cumbersome nature of use, potential for contamination and irritation to the extremity during application and use. These drawbacks reduce comfort, compliance, cause skin breakdown and may disadvantageously prevent mobility of the patient as recovery progresses after surgery. Therefore, it would be desirable to overcome the disadvantages and drawbacks of the prior art with a foot sleeve that prevents contamination, mitigates the incidence of skin breakdown and facilitates disposal with an extremity. It is contemplated that a compression apparatus including the foot sleeve reduces bulk and is not cumbersome during use to improve comfort and compliance to a patient. It is further contemplated that the compression apparatus is easily and efficiently manufactured. | <SOH> SUMMARY <EOH>Accordingly, a compression apparatus is provided that prevents contamination, mitigates the incidence of skin breakdown and facilitates disposal with an extremity for overcoming the disadvantages and drawbacks of the prior art. Desirably, a compression apparatus including the foot sleeve reduces bulk and is not cumbersome during use to improve comfort and compliance to a patient. The compression apparatus is easily and efficiently fabricated. The embodiments of the compression apparatus, according to the present disclosure, are configured to provide vascular therapy, including for example the prevention of deep vein thrombosis (“DVT”) by artificially stimulating blood vessels throughout the foot of a patient, including the toes and the heel, to increase blood circulation for patients. The compression apparatus according to the present disclosure is an intermittent pneumatic compression device for applying slow compression to a foot. Such pressure simulates blood flow that would normally result from, for example, walking, by employing a foot sleeve that is supported about a foot of a patient. The compression apparatus may have an inflatable bladder designed to cover and engage the entire area of the bottom of the foot, beyond the heel and ball to a substantial portion of the toes. The inflatable bladder wraps about the side portions of the foot via a hook and loop type connector flap that transverses the instep of the foot. The inflatable bladder may include an outside layer and an inside layer. The bladder can be formed by welding the outside layer and the inside layer together. The bladder provides a uniform application of pressure to the entire foot and is then deflated. Moreover, the compression apparatus may include bladder sections that are capable of enabling venous refill detection. The compression apparatus according to the present disclosure includes various embodiments and combinations as will be appreciated herein. The various embodiments and combinations may each be manufactured in various sizes to accommodate subjects of varying sizes as well as right and left foot models. The compression apparatus includes a strap that improves comfort by using a single piece laminate structure whose inside layer is a cushioning layer. The strap is integrated with a foot sleeve by sandwiching the strap between separate layers of the foot sleeve body. The comfort to the patient may be improved by segmenting the strap to contour about the heel of the foot. The strap can also include one or more layers configured to provide a barrier to the cushioning layer from the environment. The foot sleeve can improve ease of use by having a universal design with a one flap metatarsal closure. The strap may include a laminate consisting of various layers. The layers may include a center layer that is configured for comfort. Outside layers disposed about the center layer provide a barrier between the environment and an outer surface of the foot. One of the outside layers can be a skin contact layer that is soft to the touch. The strap may be a separate part integrated into the body of the foot sleeve by being sandwiched between separate layers of the foot sleeve body and then permanently secured. The body of the foot sleeve may be designed for adaptability to various foot sizes and shapes by employing a single metatarsal flap that facilitates ease of use. The body may be configured to provide inspection of the tops of the phalanges of the foot. One of the advantages of the present disclosure is a cushioning layer that is not in direct engagement with the outer surface of the foot. The cushioning layer has a soft skin contact layer. The foot sleeve may also include a liner that is configured to provide a physical barrier to the cushioning layer that assists in the prevention of contamination. The interior cushioning layer provides comfort and mitigates skin breakdown. Thus, the foot sleeve improves patient compliance and provides sanitation by isolating the cushioning layer from the environment. The foot sleeve is also easily manufactured, for instance, the material stack up contained in the layers allows the strap and/or foot sleeve to be cut as one piece and ensures an even stack up of materials. In one embodiment, in accordance with the principles of the present disclosure, the compression apparatus includes an expandable body configured for disposal about a foot. A strap extends from the body. The strap is configured for disposal about the foot adjacent an ankle. The strap has a first layer configured to engage an outer surface of the foot adjacent the ankle, a second layer and a third cushion layer disposed therebetween. The strap may be integrally connected to the expandable body. Alternatively, the strap may be monolithically formed with the expandable body. The expandable body can include a first, top layer and/or a second, bottom layer. Moreover, a portion of the strap member may be disposed between a top and bottom layer of the foot sleeve body. The strap may have a segmented configuration for contour with the foot. The third cushion layer can be disposed within the first layer and the second layer such that the first layer and the second layer are configured to provide a barrier to the third cushion layer. The body can include a metatarsal strap. Alternatively, the first layer includes a soft polyester material. The first layer may include a soft polyester material and polyvinylchloride. The third cushion layer may include a foam material. The second layer can have an outer surface including a loop material disposed therewith. The second layer may include a polyvinylchloride material and an outer surface having a loop material disposed therewith. Alternatively, the second layer has an outer surface including a loop material such that the metatarsal strap includes hook elements that are engageable with the loop material to mount the compression apparatus with the foot. The body may include hook elements that are engageable with the loop material to mount the compression apparatus with the foot. In an alternate embodiment, the compression apparatus has a foot sleeve including an inflatable body configured for disposal about a foot. The foot sleeve includes a metatarsal portion. A strap is integrally connected to the foot sleeve and extends therefrom. The strap is configured for disposal about the foot adjacent an ankle. The strap has a first layer configured to engage an outer surface of the foot adjacent the ankle, a second layer and a third cushion layer is disposed therebetween. The first layer and the second layer are configured to provide a barrier to the third cushion layer. The first layer may be configured to prevent engagement of the third cushion layer with the outer surface of the foot. | 20040223 | 20071016 | 20050825 | 67041.0 | 0 | THANH, QUANG D | COMPRESSION APPARATUS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,784,613 | ACCEPTED | POWER DISSIPATION REDUCTION IN WIRELESS TRANSCEIVERS | Methods and circuits for reducing power dissipation in wireless transceivers and other electronic circuits and systems. Embodiments of the present invention use bias current reduction, impedance scaling, and gain changes either separately or in combination to reduce power dissipation. For example, bias currents are reduced in response to a need for reduced signal handling capability, impedances are scaled thus reducing required drive and other bias currents in response to a strong received signal, or gain is increased and impedances are scaled in response to a low received signal in the presence of no or weak interfering signals. | 1. A method of receiving a signal using an integrated circuit, the integrated circuit comprising a signal path including a low-noise amplifier configured to receive the signal, a mixer having an input coupled to an output of the low-noise amplifier, and a low-pass filter having an input coupled to an output of the mixer, the method comprising: determining a first signal strength at a first node in the signal path in the integrated circuit; and reducing a switching current in the signal path by dynamically changing an impedance of a component in the signal path based on the first signal strength. 2. The method of claim 1 wherein the signal comprises a preamble portion and a data portion, the impedance of a component is changed while receiving the preamble portion, and the method further comprises receiving the data portion of the signal. 3. The method of claim 2 further comprising: determining a second signal strength at a second node in the signal path, wherein the second node in the signal path is after the first node in the signal path. 4. The method of claim 3 wherein the impedance of the component in the signal path is also changed based on the second signal strength. 5. The method of claim 2 wherein the component in the signal path comprises a MOS transistor. 6. The method of claim 2 wherein the component in the signal path comprises a resistor. 7. The method of claim 2 wherein the component in the signal path comprises a capacitor. 8. The method of claim 4 wherein the component in the signal path is included in the mixer. 9. The method of claim 4 wherein the component in the signal path is included in the low-pass filter. 10. A method of receiving a signal comprising a preamble portion and a data portion using an integrated circuit, the integrated circuit comprising a signal path including a low-noise amplifier configured to receive the signal, a mixer having an input coupled to an output of the low-noise amplifier, and a low-pass filter having an input coupled to an output of the mixer, the method comprising: determining a first signal strength at a first node in the signal path in the integrated circuit; and while receiving the preamble portion of the signal, dynamically changing a bias current in the signal path based on the first signal strength and while receiving the data portion of the signal, maintaining the bias current in the signal path. 11. The method of claim 10 wherein the method further comprises receiving the data portion of the signal. 12. The method of claim 11 further comprising: determining a second signal strength at a second node in the signal path, wherein the second node in the signal path is after the first node in the signal path. 13. The method of claim 12 wherein the bias current in the signal path is also changed based on the second signal strength. 14. The method of claim 11 wherein the bias current is a bias current for the low-noise amplifier. 15. The method of claim 11 wherein the bias current is a bias current for the mixer. 16. The method of claim 11 wherein the bias current is a bias current for the low-pass filter. 17. A method of receiving a signal using an integrated circuit, the integrated circuit comprising a signal path including a first circuit and a second circuit having an input coupled to an output of the first circuit, the method comprising: determining a first signal strength at a first node in the signal path in the integrated circuit, wherein the first node is before the first circuit in the signal path; dynamically changing a gain of the first circuit based on the first signal strength; and dynamically changing an impedance of a component in the second circuit based on the first signal strength. 18. The method of claim 17 wherein the signal comprises a preamble portion and a data portion, the gain and impedance are changed while receiving the preamble portion, and the method further comprises receiving the data portion of the signal. 19. The method of claim 18 further comprising: determining a second signal strength at a second node in the signal path, wherein the second node in the signal path is after the second circuit in the signal path. 20. The method of claim 19 wherein the gain of the first circuit and impedance of the component in the second circuit is also changed based on the second signal strength. 21. The method of claim 18 wherein the first circuit is a low-noise amplifier. 22. The method of claim 18 wherein the first circuit is a mixer. 23. A wireless transceiver integrated circuit comprising: a receiver comprising a signal path, the signal path comprising: a low-noise amplifier; a mixer having an input coupled to an output of the low-noise amplifier; and a low-pass filter having an input coupled to an output of the mixer; and a first signal strength indicator circuit coupled to the signal path, and configured to determine a first signal strength; wherein an impedance in the signal path is configured to be dynamically adjusted to reduce a switching current in response to the first signal strength. 24. The wireless transceiver of claim 23 further comprising: a second signal strength indicator circuit coupled to the output of the mixer, and configured to determine a second signal strength, wherein the first signal strength indicator is coupled to the output of the low-noise amplifier, and wherein the impedance in the signal path is configured to be adjusted in response to the first and second signal strengths. 25. The wireless transceiver of claim 23 further comprising: a second signal strength indicator circuit coupled to the output of the low-pass filter, and configured to determine a second signal strength, wherein the first signal strength indicator is coupled to the output of the mixer, and wherein the impedance in the signal path is configured to be adjusted in response to the first and second signal strengths. 26. A wireless transceiver integrated circuit comprising: a receiver comprising a signal path, the signal path comprising: a low-noise amplifier; a mixer having an input coupled to an output of the low-noise amplifier; and a low-pass filter having an input coupled to an output of the mixer; and a first signal strength indicator circuit coupled to the signal path, and configured to determine a first signal strength, the first signal strength the strength of a signal comprising a preamble portion and a data portion; wherein a bias current in the signal path is configured to be dynamically adjusted during the preamble portion of the signal in response to the first signal strength and further configured to be maintained during the data portion of the signal. 27. The wireless transceiver of claim 26 further comprising: a second signal strength indicator circuit coupled to the output of the mixer, and configured to determine a second signal strength, wherein the first signal strength indicator is coupled to the output of the low-noise amplifier, and wherein the bias current in the signal path is configured to be adjusted in response to the first and second signal strengths. 28. The wireless transceiver of claim 26 further comprising: a second signal strength indicator circuit coupled to the output of the low-pass filter, and configured to determine a second signal strength, wherein the first signal strength indicator is coupled to the output of the mixer, and wherein the bias current in the signal path is configured to be adjusted in response to the first and second signal strengths. 29. A wireless transceiver integrated circuit comprising: a receiver comprising a signal path, the signal path comprising: a first circuit; and a second circuit having an input coupled to an output of the first circuit; and a first signal strength indicator circuit coupled to the signal path, and configured to determine a first signal strength; wherein a gain of the first circuit is configured to be dynamically adjusted in response to the first signal strength, and wherein an impedance in the second circuit is configured to be dynamically adjusted in response to the first signal strength. 30. The wireless transceiver of claim 29 further comprising: a transmitter comprising: a power amplifier; and an output-level-sensing circuit coupled to an output of the power amplifier, wherein the output-level-sensing circuit is configured to dynamically adjust a gain of the power amplifier. | CROSS-REFERENCES TO RELATED APPLICATIONS This application claims the benefit of U.S. provisional application No. 60/451,229, filed Mar. 1, 2003, which is incorporated by reference. This application is related to U.S. provisional application No. 60/451,230, filed Mar. 1, 2003, which is incorporated by reference. BACKGROUND The present invention relates to power dissipation reduction techniques for electronic circuits, for example wireless transceiver integrated circuits. Wireless networking is quickly becoming ubiquitous, as desktop, notebook, and handheld computers are connected to share Internet access and files. Wireless networking cards compatible with PCMCIA and compact flash form factors are popular for laptops and handhelds respectively, particularly as mobile users connect to the Internet on the road at coffee shops, hotels, and airports. A downside of this connectivity is a corresponding drain on battery life, especially for these portable devices. The power consumed by a wireless transmitter and receiver reduces the usefulness of a device and sends a user on a hunt for an electrical outlet for recharging. One reason why this power drain is high is that electronic circuits are typically designed to function properly under worst-case operating conditions. For a wireless transceiver, the worst case condition is when a desired signal reception strength is low, while other transceivers or nearby electronic equipment generate interfering signals and other spurious noise. But a wireless transceiver does not always operate in these worst-case conditions. For example, a base station, router or access point may be nearby such that the received signal is strong. Also, there may be no interfering signals, or they may be relatively weak. In these situations, receiver circuit currents can be reduced below what is necessary for the worst case condition. If this is done, power dissipation is reduced, and battery life is increased. Thus, what is needed are circuits and methods that can adapt to a better-than-worst-case condition and reduce circuit currents and therefore power dissipation accordingly. SUMMARY Accordingly, embodiments of the present invention provide methods and circuits for reducing power dissipation in wireless transceivers and other electronic circuits and systems. Embodiments of the present invention use bias current reduction, impedance scaling, gain, and other dynamic changes either separately or in combination to reduce power dissipation in response to better-than-worst case conditions. For example, bias currents are reduced in response to a need for reduced signal handling capability, impedances are scaled thus reducing required drive and other bias currents in response to a strong received signal, or gain is varied and impedances are scaled in response to a low received signal in the presence of no or weak interfering signals. Alternately, currents may start low and be increased in response to worse-than-best-case conditions, or they may start at a point in between and vary up or down. These variations may be made to electronic systems generally, and are particularly suited and discussed below in the context of a wireless transceiver that may be used in networking devices, cellular telephones, and other wireless systems. An exemplary embodiment of the present invention provides a method of receiving a signal using an integrated circuit. The integrated circuit includes a signal path having a low-noise amplifier configured to receive the signal, a mixer having an input coupled to an output of the low-noise amplifier, and a low-pass filter having an input coupled to an output of the mixer. The method itself includes determining a first signal strength at a first node in the signal path in the integrated circuit and dynamically changing an impedance of a component in the signal path based on the first signal strength. A further exemplary embodiment of the present invention provides a method of receiving a signal using an integrated circuit. The integrated circuit includes a signal path having a low-noise amplifier configured to receive the signal, a mixer having an input coupled to an output of the low-noise amplifier, and a low-pass filter having an input coupled to an output of the mixer. The method itself includes determining a first signal strength at a first node in the signal path in the integrated circuit and dynamically changing a bias current in the signal path based on the first signal strength. Another exemplary embodiment of the present invention provides a method of receiving a signal using an integrated circuit. The integrated circuit includes a signal path having a first circuit and a second circuit having an input coupled to an output of the first circuit. The method itself includes determining a first signal strength at a first node in the signal path in the integrated circuit. The first node is before the first circuit in the signal path. The method further includes dynamically changing a gain of the first circuit based on the first signal strength and dynamically changing an impedance of a component in the second circuit based on the first signal strength. Still a further exemplary embodiment of the present invention provides a wireless transceiver integrated circuit including a receiver having a signal path, the signal path including a low-noise amplifier, a mixer having an input coupled to an output of the low-noise amplifier, and a low-pass filter having an input coupled to an output of the mixer, as well as a first signal strength indicator circuit coupled to the signal path and configured to determine a first signal strength. An impedance in the signal path is configured to be dynamically adjusted in response to the first signal strength. Yet a further exemplary embodiment of the present invention provides a wireless transceiver integrated circuit. This integrated circuit includes a receiver comprising a signal path, the signal path having a low-noise amplifier, a mixer having an input coupled to an output of the low-noise amplifier, and a low-pass filter having an input coupled to an output of the mixer, as well as a first signal strength indicator circuit coupled to the signal path, and configured to determine a first signal strength. A bias current in the signal path is configured to be dynamically adjusted in response to the first signal strength. Another exemplary embodiment of the present invention provides a wireless transceiver integrated circuit. This circuit includes a receiver comprising a signal path, the signal path having a first circuit; and a second circuit having an input coupled to an output of the first circuit; as well as a first signal strength indicator circuit coupled to the signal path, and configured to determine a first signal strength. A gain of the first circuit is configured to be dynamically adjusted in response to the first signal strength, and an impedance in the second circuit is configured to be dynamically adjusted in response to the first signal strength. A better understanding of the nature and advantages of the present invention may be gained with reference to the following detailed description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a wireless transceiver that may benefit by incorporation of embodiments of the present invention; FIGS. 2A and 2B illustrate examples of desired and interfering signals and noise that may be received by a circuit in a wireless receiver; FIG. 3 illustrates what can occur as a maximum signal handling capability is reduced in the worst-case signal condition; FIG. 4 illustrates a portion of a receiver consistent with an embodiment of the present invention; FIG. 5 illustrates the relationship between a required bias current and a given output signal for a representative circuit; FIG. 6 is an example of how a circuit's impedances may be scaled to reduce drive currents, and depending on the circuit configuration used, to reduce associated bias currents as well; FIG. 7 illustrates how gain may be inserted in a signal path to improve a circuit's signal to noise ratio; FIGS. 8A-8D illustrate some of the possible power saving techniques that may be used when received desired and interferer signals are all at a low power level; FIGS. 9A-9C illustrate one of the possible power saving techniques that may be used when a received desired signal is strong while all interfering signals are at a low power level; FIGS. 10A-10C illustrate one of the possible power saving techniques that may be used when received desired and interferer signals are all at a high power level; FIGS. 11A-11D illustrate one of the possible power saving techniques that may be used when a received desired signal is weak while one or more interfering signals are strong; FIG. 12 is a summary illustrating four different input conditions and some of the appropriate power-saving changes that may be made in response to those conditions; FIG. 13 shows how power may be saved as a function of time by employing one or more of the power saving methods consistent with embodiments of the present invention; FIG. 14 is a block diagram of a portion of a receiver consistent with an embodiment of the present invention; and FIG. 15 is a block diagram of a portion of a transmitter consistent with an embodiment of the present invention. DESCRIPTION OF EXEMPLARY EMBODIMENTS FIG. 1 is a block diagram of a wireless transceiver that may benefit by incorporation of embodiments of the present invention. This wireless transceiver may be designed to send and receive signals consistent with the IEEE 802.11a, 802.11b, 802.11g, or other signaling standard or combination of standards. This figure, as with all the included figures, is shown for illustrative purposes only and does not to limit either the possible embodiments of the present invention or the claims. There are three main portions of this transceiver circuit, a receiver, transmitter, and synthesizer. This transceiver may be completely or partially integrated on a semiconductor chip, or it may be integrated onto multiple integrated circuits. In a specific embodiment, the circuitry bounded by dashed line 100 is integrated on a single chip coupled to one or more external components or circuits. The integrated circuit or circuits forming this wireless transceiver may incorporate various integrated circuit devices such as a bipolar, CMOS, or BiCMOS devices made using a silicon, silicon-germanium (SiGe), gallium arsenide or other III-V process, or other manufacturing process. Embodiments of the present invention may also be applicable to circuits manufactured using nanotechnology processing. The receiver includes a signal path formed by low-noise amplifier 102, I and Q mixers 104 and 106, low pass filters 108 and 110, and baseband amplifiers 114 and 116. Other circuitry in the receiver includes received strength indicator 122, automatic gain control circuit 166, baseband gain control circuit 120, tuning circuit 112, and offset cancellation circuit 118. The transmitter includes input up-converter mixers 124 and 126, summing node 176, which may be conceptual rather than an actual circuit, transmit variable gain amplifier 128, and power amplifier 130. The synthesizer includes a voltage-controlled oscillator 148, which drives I and Q buffers 154 and 152, prescaler 156, reference clock buffer 142 and divider 158, phase-frequency detector 160, charge pump 162, and loop filter 146, which in a specific embodiment is formed by external components. Signals are received on an antenna, not shown, and typically pass through an RF switch and bandpass filter before being received by the low-noise amplifier 102 on line 101. The low noise amplifier gains the received signal and provides it to quadrature mixers 104 and 106. I and Q mixers 104 and 106 down-convert the received signal to baseband by multiplying them with quadrature versions of the oscillator signal provided by buffers 152 and 154. This down conversion also produces a high frequency component at a frequency that is equal to the sum of the frequencies of the received signal and the VCO. This unwanted signal is filtered by low pass filters 108 and 110, which in turn drive baseband amplifiers 114 and 116. The outputs of baseband amplifiers 114 and 116 are typically converted to digital signals by analog-to-digital converters at the front end of a digital signal processing block. In the transmit mode, I and Q versions of the signal to be transmitted are provided on lines 121 and 123 to up-convert mixers 124 and 126. These up-convert mixers multiply the I and Q portions of the transmit signal by quadrature versions of the VCO signal provided by buffers 152 and 154. The outputs of the up-convert mixers 124 and 126 are summed, and amplified by transmit VGA 128, which in turn drives power amplifier 130. The output of power amplifier 130 is typically filtered, and passes through the RF switch to the antenna for transmission. A reference clock is received and buffered by the reference buffer 142. The VCO generates quadrature oscillatory signals that are divided by prescaler 156. The reference clock is typically generated by a crystal or other stable periodic clock source. The phase-frequency detector 116 compares the phase or frequency (depending on whether the synthesizer is tracking or acquiring the correct frequency) of the divided VCO signal and the reference clock, or a divided version of the reference clock, and generates an error signal, which drives the charge pump 162. The output signal of the charge pump 162 is filtered by the loop filter 146, which is commonly a lead-lag filter, and which provides a tuning or correction signal to the VCO 148. Embodiments of the present invention may be used to reduce the power dissipation of one or more of these included circuits. For example, the power dissipation in the low-noise amplifier 102, down-convert mixers 104 and 106, low pass filters 108 and 110, or baseband amplifiers 114 and 116 may be optimized. Also, power dissipation in up-convert mixers 124 126, variable gain amplifier 128, and power amplifier 130 may also be optimized. Similarly, VCO 148 and prescaler 156 currents may be adjusted. Embodiments of the present invention may also be applied in other circuits which may be included in other integrated circuit receivers, transmitters, transceivers, or other electronic circuits or systems. When a receiver is actively receiving a desired signal, each block in the signal path has at its input the desired signal as well as noise and possibly interfering signals. The desired signal is the useful, information-carrying portion of a received signal. The noise may be thermal, shot, or other noise generated on the integrated circuit, in addition to received noise generated by sources external to the chip. The noise at the input of a block may be referred to as the equivalent input noise. The interfering signal or signals, or interferers, may be generated by similar transceivers, or other electrical equipment, circuits, or systems. FIGS. 2A and 2B illustrate examples of desired signals, interferers, and noise that may be received by one of the various circuits in a wireless receiver. In each of these figures, the signal strength is plotted along a Y-axis 204 or 254 as a function of frequency along an X-axis 202 or 252. In the example of FIG. 2A, a received desired signal 206 is large in comparison to interfering signals 208 and 210. In these examples, two interfering signals are shown for illustrative purposes, though there may be no such signals, one such signal, or more than two such signals in the frequency range of interest. Also, while for these examples the interferers are shown as being at a higher frequency than the desired signal, there may be one or more interferers at higher or lower frequencies as the desired signal. In this specific example, the acceptable noise floor 214 is relatively high, while maximum signal handling capability Smax 212 (that is the maximum signal power that can be handled with an acceptably low distortion) needs only to be high enough to accommodate the desired signal. For this specific example, the circuit receiving this input spectrum only requires a relatively small dynamic range for proper operation, that is the range between Smax 212 and the noise floor 214 is relatively small. Conversely, in the example shown in FIG. 2B, the desired signal 256 is relatively weak compared to the large interferers 258 and 260. In this example, the noise floor 264 should be relatively low so as to prevent an unacceptable level of error in the recovery the desired signal 256. The maximum signal handling capability Smax 262 should be relatively high to accommodate the large interferers in order to avoid the creation of intermodulation products as described below. Accordingly, in this specific example, the circuit receiving this input spectrum should have a large dynamic range, particularly in comparison to the example of FIG. 2A. It should be noted that the noise level or noise floors shown in these and the other included figures is the noise density integrated over the bandwidth of interest. For simplicity and comparison, this level is shown as a horizontal line, and is not meant to imply noise density. Often in wireless receivers, a circuit at different times will receive an input spectrum similar to those shown in FIGS. 2A and 2B. The input spectrum of FIG. 2B is generally considered the worst-case input signal, and typical design methodology involves designing a receiver for this condition, specifically the weakest desired signal accompanied by largest interference level. Circuit impedances and currents are set such that the noise floor 264 is sufficiently low for an acceptable bit-error rate, while bias currents are set sufficiently high for the required Smax 262. Conversely, the input spectrum in FIG. 2A is that of the best-case input signal, specifically, a robust desired signal accompanied by no or low-level interferers. In this case, the noise floor 214 may be allowed to rise, while the maximum signal handling capability Smax 212 may be reduced. When this is done, the receiver circuit may save significant power. For example, the circuit's impedances may be increased, thus reducing required drive currents. Similarly, bias currents may be lowered, thus reducing the maximum signal in handling capability. The minimum power dissipation for a circuit is proportional to the required maximum signal-to-noise ratio, which is the ratio between Smax 212 or 262 and N 214 and 264. Thus, a circuit receiving an input similar to the one shown in FIG. 2A can dissipate less power than one receiving the input as shown in FIG. 2B, while still achieving an acceptable bit-error rate. FIG. 3 illustrates what can occur when the maximum signal handling capability Smax 314 is reduced in the worst-case condition, that is when a weak desired signal 306 is accompanied by large interferers 310 and 312. Again, signal strength is plotted along a Y-axis 304 as a function of frequency along X-axis 302. In this specific example, Smax 314 is reduced below the peak levels of the interferers 310 and 312. Since Smax is low, the circuit cannot handle the interferers linearly. The resulting nonlinearities lead to a mixing of the interferers and the creation of intermodulation products 308 (for example, a third-order intermodulation distortion, IM3), one of which in this example occurs at the same frequency as the desired signal 306. As can be seen, if the intermodulation products 308 become excessive, the received signal bit error rate may become excessive, and the desired signal 306 may be lost. Accordingly, while Smax may be lowered even under some unfavorable conditions in order to reduce power, care should be taken to avoid corruption of the received desired signal. FIG. 4 illustrates a portion of a receiver consistent with an embodiment of the present invention. Included is a filter 430. An optional gain element 420 is placed in front of the filter 430 in order to increase signal levels. Signal strength indicator circuits 440 and 450 are connected to input line 410 and output line 460. In this specific example, the input signal spectrum on line 410 is shown as desired signal 412 and interferers 414 and 416. The signal spectrum at the output line 460 is shown as desired signal 462 and interferers 464 and 466. The signal strength indicators 440 and 450 do not provide information as to the relative sizes of the desired and interfering signals. Rather, a cumulative signal level is provided at their outputs. For example, the first signal strength indicator 440 outputs a level corresponding to the sum of desired signal 412 and interfering signals 414 and 416, while the second signal strength indicator 450 provides a signal level corresponding to the sum of desired signal 462 and interfering signals 464 and 466. In this specific example, the gain of the gain and filter circuit combinations is shown as approximately one, while the interfering signals 414 and 416 signal levels are reduced. A comparison of the signal levels provided by the signal strength indicators 440 and 450 indicates that much of the combined received signal on line 410 has been filtered. Accordingly, it may be deduced that large interfering signals present at the input are being filtered by the filter 430. From this information, as will be shown in greater detail below, the bias, impedance, and gain of the gain stage 420 and filter 430 combination may be optimized to reduce power dissipation. There are several real world situations where the received signal is better than the worst-case condition such that power can be saved. For example, large interferers may be present only part of the time, that is, on a temporary or transient basis. The interfering equipment may be some distance from the transceiver, or it may be operating in the low power mode. Also, the desired signal may be very strong as compared to the noise and interferers, for example a hub, router, or access point may be nearby. Some transceivers consistent with embodiments of the present invention are designed to work with more than one data transfer specification or standard. In this case, when a transceiver is operating in a mode having a lower data rate, the power saving techniques described here may be employed. FIG. 5 illustrates the relationship between a required biased current 516 for a given output signal 514 for a representative circuit 510. If the output signal current level is relatively low, such as the output current shown as 526, the corresponding bias current 528 may be low. Conversely, if the output signal current level is larger as with the example 536, the corresponding bias current level 538 should also be high. Accordingly, if a bias current is initially set high to handle large a large input signal, for example a large interferer, this current may be reduced if the input signal is smaller. There are many ways by which these bias currents can be reduced. For example, the current may be generated by placing a voltage across a resistor by applying a bias voltage to the base of a device whose emitter is connected to ground through a resistance. In this case, the resistor may be increased by opening switches across portions of the resistance, or lowering the bias voltage applied at the base. Several ways in which this may be done will be readily understood by one skilled in the art. FIG. 6 is an example of how a circuit's impedances may be scaled to reduce drive currents, and, depending on the circuit configuration used, associated bias currents as well. A driver 612 has a load R 614 and C 616. The frequency response of this circuit is the same as that seen by driver 622, which drives an impedance of 2R 624 and C/2 626. But the impedance of the load seen by driver 622 is double that seen by 612, thus the output current required by the driver 622 is reduced by one-half. As an example, the output stage of each of these drivers may be a Class A emitter follower formed by an emitter follower connected to a current source. When the outputs are driven high, the emitter of driver 622 need supply only one-half the drive current as driver 612. In this way, an impedance can be scaled in order to decrease a circuit's required drive current. Also, the discharge current for driver 622 is only one half that of driver 612 for a given negative-going slew rate. Thus, the current source of 622 may be reduced by the same factor of one-half as compared to driver 612. In this example, the bias current, that is the current in the pull-down current source can be reduced. Many other examples where drive currents and possibly bias currents may be reduced will be appreciated by one skilled in the art. FIG. 7 illustrates another degree of freedom that made be employed to reduce current levels in a transceiver. Specifically, a gain element 720 may be inserted in front of a circuit block 730 in order to improve the combined circuit's signal-to-noise ratio by a factor equal to the gain of the inserted gain block. This is particularly useful when large interferers are absent and the desired received signal is moderate or low. Specifically, gain is added to the signal while impedances are increased, which raise the noise floor. In this way, a given signal-to-noise ratio may be maintained while the power is decreased. The gain of such an element may be varied by increasing a current in a differential pair or increasing a load resistance using switches. Many other examples where the gain of this element may be varied will be appreciated by one skilled in the art. These variables, or degrees of freedom, specifically reducing bias currents, increasing impedances, and increasing gain may be used as in the following examples. FIG. 8A is a block diagram of a functional block 820 and optional gain element 810 in accordance with an embodiment of the present invention. Functional block 820, like the functional blocks in the following diagrams, may be a filter, mixer, amplifier, or other circuit or circuits in a wireless transceiver or other electronic circuits or system. An input signal is received on line 812 by the optional gain element 814. When the optional gain block 810 is not used, the input signal may be received directly by the function block 820. The gain of the optional gain element 812 is controlled by a gain control signal on line 814. The functional block receives an output signal from the optional gain element 810 and provides an output VOUT on line 822. The lines in this and the other included figures may be one or more lines, depending on whether single-ended, differential, or other type of signaling is employed. One or more impedances are under control of signals on impedance control lines 824. Similarly, one or more bias currents in the function block are under control of one or more signals on bias control lines 826. These various control lines may be logic signals, analog signals, voltage or currents lines, or other signal or bias lines. In other embodiments of the present invention, the gain control element 810 may be included in the function block 820. Also, various embodiments may not incorporate either or both the impedance control and bias control. FIG. 8B is an example input that may be present on line VIN 812. In this example, a desired signal 836 is relatively weak, as are interfering signals 837 and 838. The initial bias and circuit configuration is such that the noise floor 833 and maximum signal handling capability Smax 831 are adjusted for worst case conditions. The circuit of FIG. 8A, as with all the circuits described here, receives noise at its input which may be referred to as input equivalent noise or input referred noise. Additionally, the circuit of FIG. 8A generates noise which is added to the input referred noise. Depending on the gain characteristics of the circuitry, the output noise at various frequencies may be greater than, equal to, or less than the input referred noise. For simplicity, the noise floor and maximum signal handling capability Smax, in this and the other figures, are shown as straight lines, though the noise and Smax are typically curved as a function of frequency. That the input spectrum is as shown in FIG. 8B can be determined, for example, by low signal strength indications on line VIN 812 and VOUT 822. That is, a low level signal strength indication on line VIN 812 indicates that no portion of the input signal is particularly large. For this exemplary input, there are at least two methods by which the power dissipation for this circuitry may be reduced. Depending on the exact circuits and structures used, one of these methods may be preferred. In FIG. 8C, the bias current is decreased, thereby lowering the maximum signal handling capability 841 as compared to 831, closer to the desired and interfering signal levels. Again, the bias currents in the function block 820 may be reduced by switching impedances that appear across a voltage thereby changing a resulting bias current, by reducing a voltage at the gate of a MOS or base of a bipolar transistor, or by other methods. In FIG. 8D, a second method of reducing power dissipation in the function block 820 is employed. Specifically, Smax 851 is held constant as compared Smax 831. The desired and interfering signals are amplified such that they are closer to the available signaling handling capability 851. Also, the noise floor 853 is raised as compared to noise floor 833 in FIG. 8B. Specifically, the noise contributed by the function block 820 is increased, such that the noise at its output is increased to noise floor 853. This is done by increasing one or more impedance in function block 810, such that drive currents inside that block are reduced. Depending on the exact configuration, this may also allow some biasing currents to be reduced, while maintaining the maximum signal handling capability 851 at a sufficient level. Alternately, these two methods of reducing power dissipation in function block 820 may be done in combination. The included examples are explained for the exemplary situation where biasing and other parameters are set for worst-case conditions, and then changed to save power when it is discovered that the conditions are better-than-worst case. Alternately, the bias currents and other parameters may be set for maximum power savings, or an intermediate point, and the power can be adjusted from there. FIG. 9A illustrates a block diagram including an optional gain element 910 and function block 920. Again, an input signal is received on line 912 by optional gain element 910 which in turn drives function block 920. The function block provides an output VOUT on line 922, and receives impedance and bias control signals on lines 924 and 926. FIG. 9B shows the spectrum for what may be considered a best-case received signal. Specifically, the desired signal 936 is strong, while the interfering signals 937 and 938 are relatively weak. This may be determined, for example, by detecting a large signal level at the input line VIN 812 and a large signal level after a filter, since these readings would indicate that a large signal is received, but that it is at the desired signal frequency. The maximum signaling capability 931 and noise floor 933 are shown as being set for the worst case conditions. In this case, the noise floor 933 is lower than the maximum allowed for proper signal reception. Accordingly, one or more impedance in the function block 920 may be increased, such that the noise floor 943 rises as shown in FIG. 9C. In this way one or more the driving currents in the function block 920 may be reduced. Similarly, since the drive current is reduced, one or more bias current may also be reduced, depending on the exact circuit configuration. FIG. 10A illustrates a block diagram showing an optional gain element 1010 driving a function block 1020. An input signal is received by the gain element 1010 on line 1012, and an output is provided by function block 1020 on line VOUT 1022. One or more gain control signals present on lines 1014 control the gain of gain control element 1010, while one or more impedance and bias control signals are received by the function block 1020 on line to 1024 and 1026. FIG. 10B illustrates a received signal that may be received on line VIN 1012. In this example, the desired signal 1036 and interferers 1037 and 1038 are each relatively large. This may be determined, for example, by detecting a large signal level at the input line VIN 812 and a smaller signal level after a filter, since these readings would indicate that a large signal is received, but that interferers are being reduced. As before, in this example, the noise floor 1033 and maximum signal handling capability 1031 are initially set for the worst case conditions. Since the desired signal is relatively large in this case, the noise floor may be allowed to rise, a shown by noise floor 1043 in FIG. 10C. Since the desired signal 1046 and interferers 1047 are large, the maximum signal handling capability Smax 1041 remains constant. Again, the noise floor is increased by increasing impedances in the function block 1020. This reduces the required drive current, and may also allow for a reduction in bias currents. FIG. 11A illustrates a block diagram including an optional gain element 1110 and function block 1120 in accordance with an embodiment of the present convention. An input signal is received on line 1112 by the optional gain control element 1110, while an output signal is provided by the function block 1120 on line VOUT 1122. Gain, impedance, and bias control signals are received on lines 1114, 1124, and 1126. FIG. 11B is an exemplary input signal that may be received by the gain control element 1110 on line VIN 1112. In this specific example, the desired signal 1136 is relatively low or weak while the interfering signals 1137 and 1138 are large. This may be determined, for example, by detecting a large signal level at the input line VIN 812 and a much smaller signal level after a filter, since these readings would indicate that a large signal is received and that large interferers are being reduced such that the resulting signal, the desired signal, is relatively weak. Again, the maximum signal handling capability 1131 and noise floor 1133 are initially set for worst case conditions. If the desired signal is sufficiently low, while the interferers are sufficiently high, power savings may not be achievable over the worst case settings, since this is in fact the worst case condition. But, if the desired signal is somewhat larger than the worst case condition, then power may be saved in at least two different ways. For example, FIG. 11C shows the maximum signal handling capability 1141 being lowered. In this case, the interfering signals 1147 in 1148 began to clip and distort, thereby creating intermodulation products 1145, which distort the desired signal 1146. So long as care is taken to not corrupt the desired signal 1146 beyond an acceptable limit, typically measured by a bit-error rate, power may be reduced in this way. Similarly, in FIG. 11D, the noise floor 1153 is raised somewhat, thereby saving power. Again, this may be done so long as the noise floor is not sufficiently high that the system bit-error rate becomes unacceptable. FIG. 12 is a summary of the above four examples. The received signal strengths are shown in column 1210, while appropriate power saving responses are listed in column 1220. Specifically, in row 1230, the desired signal and interferer signal strengths are both weak or small. In this case, proper responses include decreasing Smax, or increasing one or more circuit impedances while increasing the circuit gain. Depending on the exact circuit configuration, one of these options may be preferred over the other. Alternately, they may be done in combination, or done in combination with other power saving techniques. Also, in some specific embodiments, when both desired signal and interferer signal strengths are small, the gain may need to be increased while the impedance is maintained or not increased in order to keep the noise floor low. In row 1240, the desired signal strength is strong or large, while the interfering signals are small. In this case, an appropriate response is to increase one or more of the circuit impedances. Again, depending on the exact circuit in question, one or more of the bias currents may also be reduced. In row 1250, both the desired signals and interfering signal strengths are large. Again, in this case an appropriate response is to increase one or more of the circuit impedances. In row 1260, the received desired signal strength is weak or small, while the interfering signals are large. Since this is the worst case situation for which the circuit is designed, substantial power savings are difficult to achieve. However, again, if the received signal is above a minimum level necessary for proper operation, some distortion of the interferers or raising of the noise floor may be acceptable. It should be noted that not all possible signal conditions are listed here. For example, either the signal or interferer may be of a relatively medium strength, or the interferer may be absent. Also, these terms are for exemplary purposes and are not meant to convey specific signal conditions, but rather are only qualitative. The proper response to a specific condition depends on the embodiment of the present invention, the particular circuit topology, the requirements of the signaling standard used, as well as other constraints. FIG. 13 is an example shown how power may be saved as a function of time by employing one or more of these methods consistent with embodiments of the present invention. Power is plotted along a Y-axis 1304 as a function of time along X-axis 1302. Conventional worst case design would fix power dissipation at line 1310. As can be seen, dynamic power dissipation 1320 under the control of variable gains, impedances, biasing, or combination thereof, allows for a lower average power 1330 as compared to the power dissipated 1310 by the conventional design. FIG. 14 is a block diagram of a portion of a receiver consistent with an embodiment of the present invention. Included are low-noise amplifier 1410, mixer 1420, gain stage 1430, filter 1440, AGC amplifier 1450, and VCO 1460. Signal strength detection is done at the output of the low-noise amplifier by signal strength indicator 1470, at the output of the mixer by signal strength indicator 1472, and at the output of the filter by signal strength indicator 1474. The outputs of the signal strength indicator circuits are received by the computational circuit 1470, which in turn controls gain and power control circuits 1480 and 1485. Power and gain control circuits 1480 and 1485 control the gain, biasing, and impedance levels of the circuits in the receiver signal path. Also, the gain and power control circuits may control the same parameters in the VCO 1460. This figure is greatly simplified for purposes of explanation. For example, the quadrature nature of the mixers and following circuits are not shown. Also, power-down and start-up circuits are not included. The current level in the low-noise amplifier determines a multitude of parameters including voltage gain, linearity, input impedance matching, and noise figure. When conditions are better than worst-case, some of these parameters may be relaxed while maintaining an acceptable bit-error rate, thus saving power. The bias current in the mixers effect that block's noise figure and linearity. Care is taken in reducing power in this block so as not to increase nonlinearities, particularly the third-order nonlinearity as measured by IP3, the third-order intercept point, beyond an acceptable limit. A key parameter of the VCO is phase noise, an increase in which increases the sidebands on either side of the oscillation signal. During transmission, the phase noise should be kept low to avoid interference with adjacent channels and for preserving modulation information. During reception however, if the conditions are better than worst case, the phase noise requirement for the VCO is relaxed, and power can be saved consistent with embodiments of the present invention. The achievable phase noise power spectral density is approximately inversely proportional to the bias current used. Thus, when low phase noise is not required during reception, bias current in the VCO can be reduced. Most of the power savings in a transceiver in accordance with embodiments of the present invention is achieved in the receiver portion. Additional power may be saved in the transmitter section. FIG. 15 is a block diagram of a transmitter portion consistent with an embodiment of the present invention. Included is a signal path formed by gain stage 1510 and power amplifier 1520. The output power level is sensed by output level sensing circuit 1550, which in turn adjusts the biasing of the power amplifier 1520 through the power control circuit 1540. Additionally, a transmitter level control signal is received by power control circuits 1530 and 1540, which in turn control the biasing of gain stage 1510 and power amplifier 1520. Gain control circuit 1560 also adjusts the gain of gain stage 1510 and power amplifier 1520. Additional circuitry that varies impedances in each of these circuits may also be included. Since the gain, impedance and biasing of these blocks are being dynamically varied, care must be taken to not negatively affect the signal being processed. For example, specific embodiments of the present invention perform some or all of these variations during preamble. Also, as changes occur, the circuits in some embodiments are limited such that they may only adapt to an improvement in conditions after frames are completed. If conditions worsen, the circuits may be allowed to change in order to save the data. Alternately, a system may be manually calibrated, for example at set up, and when the network configuration is changed. The above description of specific embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form described, and many modifications and variations are possible in light of the teaching above. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. | <SOH> BACKGROUND <EOH>The present invention relates to power dissipation reduction techniques for electronic circuits, for example wireless transceiver integrated circuits. Wireless networking is quickly becoming ubiquitous, as desktop, notebook, and handheld computers are connected to share Internet access and files. Wireless networking cards compatible with PCMCIA and compact flash form factors are popular for laptops and handhelds respectively, particularly as mobile users connect to the Internet on the road at coffee shops, hotels, and airports. A downside of this connectivity is a corresponding drain on battery life, especially for these portable devices. The power consumed by a wireless transmitter and receiver reduces the usefulness of a device and sends a user on a hunt for an electrical outlet for recharging. One reason why this power drain is high is that electronic circuits are typically designed to function properly under worst-case operating conditions. For a wireless transceiver, the worst case condition is when a desired signal reception strength is low, while other transceivers or nearby electronic equipment generate interfering signals and other spurious noise. But a wireless transceiver does not always operate in these worst-case conditions. For example, a base station, router or access point may be nearby such that the received signal is strong. Also, there may be no interfering signals, or they may be relatively weak. In these situations, receiver circuit currents can be reduced below what is necessary for the worst case condition. If this is done, power dissipation is reduced, and battery life is increased. Thus, what is needed are circuits and methods that can adapt to a better-than-worst-case condition and reduce circuit currents and therefore power dissipation accordingly. | <SOH> SUMMARY <EOH>Accordingly, embodiments of the present invention provide methods and circuits for reducing power dissipation in wireless transceivers and other electronic circuits and systems. Embodiments of the present invention use bias current reduction, impedance scaling, gain, and other dynamic changes either separately or in combination to reduce power dissipation in response to better-than-worst case conditions. For example, bias currents are reduced in response to a need for reduced signal handling capability, impedances are scaled thus reducing required drive and other bias currents in response to a strong received signal, or gain is varied and impedances are scaled in response to a low received signal in the presence of no or weak interfering signals. Alternately, currents may start low and be increased in response to worse-than-best-case conditions, or they may start at a point in between and vary up or down. These variations may be made to electronic systems generally, and are particularly suited and discussed below in the context of a wireless transceiver that may be used in networking devices, cellular telephones, and other wireless systems. An exemplary embodiment of the present invention provides a method of receiving a signal using an integrated circuit. The integrated circuit includes a signal path having a low-noise amplifier configured to receive the signal, a mixer having an input coupled to an output of the low-noise amplifier, and a low-pass filter having an input coupled to an output of the mixer. The method itself includes determining a first signal strength at a first node in the signal path in the integrated circuit and dynamically changing an impedance of a component in the signal path based on the first signal strength. A further exemplary embodiment of the present invention provides a method of receiving a signal using an integrated circuit. The integrated circuit includes a signal path having a low-noise amplifier configured to receive the signal, a mixer having an input coupled to an output of the low-noise amplifier, and a low-pass filter having an input coupled to an output of the mixer. The method itself includes determining a first signal strength at a first node in the signal path in the integrated circuit and dynamically changing a bias current in the signal path based on the first signal strength. Another exemplary embodiment of the present invention provides a method of receiving a signal using an integrated circuit. The integrated circuit includes a signal path having a first circuit and a second circuit having an input coupled to an output of the first circuit. The method itself includes determining a first signal strength at a first node in the signal path in the integrated circuit. The first node is before the first circuit in the signal path. The method further includes dynamically changing a gain of the first circuit based on the first signal strength and dynamically changing an impedance of a component in the second circuit based on the first signal strength. Still a further exemplary embodiment of the present invention provides a wireless transceiver integrated circuit including a receiver having a signal path, the signal path including a low-noise amplifier, a mixer having an input coupled to an output of the low-noise amplifier, and a low-pass filter having an input coupled to an output of the mixer, as well as a first signal strength indicator circuit coupled to the signal path and configured to determine a first signal strength. An impedance in the signal path is configured to be dynamically adjusted in response to the first signal strength. Yet a further exemplary embodiment of the present invention provides a wireless transceiver integrated circuit. This integrated circuit includes a receiver comprising a signal path, the signal path having a low-noise amplifier, a mixer having an input coupled to an output of the low-noise amplifier, and a low-pass filter having an input coupled to an output of the mixer, as well as a first signal strength indicator circuit coupled to the signal path, and configured to determine a first signal strength. A bias current in the signal path is configured to be dynamically adjusted in response to the first signal strength. Another exemplary embodiment of the present invention provides a wireless transceiver integrated circuit. This circuit includes a receiver comprising a signal path, the signal path having a first circuit; and a second circuit having an input coupled to an output of the first circuit; as well as a first signal strength indicator circuit coupled to the signal path, and configured to determine a first signal strength. A gain of the first circuit is configured to be dynamically adjusted in response to the first signal strength, and an impedance in the second circuit is configured to be dynamically adjusted in response to the first signal strength. A better understanding of the nature and advantages of the present invention may be gained with reference to the following detailed description and the accompanying drawings. | 20040223 | 20060307 | 20060316 | 64337.0 | H04B1700 | 2 | VUONG, QUOCHIEN B | POWER DISSIPATION REDUCTION IN WIRELESS TRANSCEIVERS | SMALL | 0 | ACCEPTED | H04B | 2,004 |
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10,784,639 | ACCEPTED | Fluid conduit connector apparatus | A fluid conduit connector apparatus that the approximates pneumatic characteristics of a removed pneumatic system component when a fluid conduit is removed from a pneumatic system. The fluid conduit connector apparatus includes a port portion having a valve disposed therein. The valve closes to provide a reduced fluid orifice when a fluid conduit is removed from the port. The reduced fluid orifice is configured to provides pneumatic characteristics of the device being disconnected to facilitate uninterrupted operation of a timed pressure source having pneumatic sensing capability. | 1. A fluid connector apparatus adapted for use with a compression apparatus, the fluid connector apparatus comprising: a connector including a plurality of fluid ports formed therewith that facilitates fluid communication between a plurality of fluid conduits of the compression apparatus and a pressurized fluid source, each of the plurality of fluid ports defining a fluid orifice configured for fluid flow; and a valve being disposed with one of the fluid ports, said valve being operable to engage the fluid port such that disconnect of a fluid conduit of the compression apparatus corresponding to the fluid port from the connector reduces a dimension of the fluid orifice of the fluid port. 2. The fluid connector apparatus according to claim 1 wherein the connector includes a first connector having a first plurality of fluid ports and a second connector having a second plurality of fluid ports. 3. The fluid connector apparatus according to claim 1 wherein upon disconnect of the fluid conduit, said valve is adapted to approximate pneumatic characteristics of the fluid port having the valve in an open position. 4. The fluid connector apparatus according to claim 1 wherein the valve completely closes the fluid port. 5. The fluid connector apparatus according to claim 2 wherein said first connector removably mates with the second connector. 6. The fluid connector apparatus according to claim 4 wherein said valve includes a spring loaded plunger. 7. The fluid connector apparatus according to claim 6 wherein said fluid port includes a cap portion disposed therein and said spring loaded plunger engages said cap portion to create an orifice that provides a pneumatic behavior approximating said in an open position. 8. The fluid connector apparatus according to claim 2 further comprising a gasket disposed to facilitate fluid sealing between said first and second connectors. 9. The fluid connector apparatus according to claim 2 wherein said second connector includes a locking arm extending therefrom such that said locking arm is adapted to releasably retain said first connector with said second connector. 10. The fluid connector apparatus according to claim 9 wherein said second connector includes a slot for engaging said locking arm. 11. A fluid connector apparatus adapted for use with a compression apparatus, the fluid connector apparatus comprising: a first connector having tubular walls defining a plurality of fluid ports adapted to connect to a first plurality of fluid conduits, each of the plurality of fluid ports defining a fluid orifice configured for fluid flow wherein one of said ports comprises a coupling port, wherein one of said first plurality of fluid conduits comprises a coupling fitting adapted for removable mating with said coupling port; a valve disposed within said coupling port, said valve being operable to engage the coupling port such that disconnect of the coupling fitting from the coupling port reduces a dimension of the fluid orifice of the coupling port; and a second connector adapted to connect to a second plurality of fluid conduits and mate with said first connector. 12. The fluid connector apparatus according to claim 11 wherein said valve includes a spring loaded plunger, wherein said coupling fitting includes an engagement portion extending therefrom and said spring loaded plunger is displaced by said engagement portion when said coupling fitting is mated to said coupling port. 13. The fluid connector apparatus according to claim 12 wherein said coupling port includes a cap portion disposed therein and said spring loaded plunger engages said cap portion to reduce the dimension of the fluid orifice of the coupling port. 14. The fluid connector apparatus according to claim 11 wherein upon disconnect of the coupling fitting, said valve is adapted to approximate pneumatic characteristics of the coupling port having the valve in an open position. 15. The fluid connector apparatus according to claim 11 wherein the valve completely closes the coupling port. 16. The fluid connector apparatus according to claim 11 further comprising a gasket disposed to facilitate fluid sealing between said first and second connectors. 17. The fluid connector apparatus according to claim 11 wherein said first connector includes a locking arm extending therefrom such that said locking arm is adapted to releasably retain said first connector with said second connector. 18. The fluid connector apparatus according to claim 17 wherein said second connector includes a slot for engaging said locking arm. 19. A fluid connector apparatus adapted for use with a compression apparatus, the fluid connector apparatus comprising: a first connector including a first plurality of fluid ports formed therewith that fluidly communicates with a first plurality of fluid conduits, each of the plurality of fluid ports defining a fluid orifice configured for fluid flow; a second connector in fluid communication with a second plurality of fluid conduits and comprising a plurality of couplings in fluid communication therewith; and restrictor means within said first connector for engaging the one of the fluid ports of the first connector such that disconnect of a corresponding fluid conduit from the first connector reduces a dimension of the fluid orifice of the corresponding fluid port to approximating desired pneumatic characteristics of the fluid port. 20. The fluid connector apparatus according to claim 19 wherein the valve completely closes the fluid port. | BACKGROUND 1. Technical Field The present disclosure generally relates to the field of fluid conduit connectors for application to multiple fluid line systems and more particularly to fluid line connectors having a valved port. 2. Description of the Related Art Medical conditions that form clots in the blood, such as deep vein thrombosis (DVT) and peripheral edema, are a major concern to immobile medical patients. Such patients include those undergoing surgery, anesthesia, extended periods of bed rest, etc. These blood clotting conditions generally occur in the deep veins of the lower extremities and/or pelvis. These veins, such as the iliac, femoral, popiteal and tibial return deoxygenated blood to the heart. When blood circulation in these veins is retarded due to illness, injury or inactivity, there is a tendency for blood to accumulate or pool. A static pool of blood provides an ideal environment for dangerous clot formations. A major risk associated with this condition is interference with cardiovascular circulation. Most seriously, a fragment of the blood clot can break loose and migrate. A pulmonary emboli can form a potentially life-threatening blockage in a main pulmonary artery. The conditions and resulting risks associated with patient immobility can be controlled or alleviated by applying intermittent pressure to a patient's limb to assist in blood circulation. Known devices such as one piece pads and compression boots have been employed to assist in blood circulation. See, for example, U.S. Pat. Nos. 6,290,662 and 6,494,852. Sequential compression devices have been used, which consist of an air pump connected to a disposable wraparound pad by a series of fluid conduits such as air tubes, for example. The wraparound pad is placed around the patient's leg. Air is then forced into different parts of the wraparound pad in sequence, creating pressure around the calves and improving venous return. These known devices suffer from various drawbacks due to their bulk and cumbersome nature of use. These drawbacks cause patient discomfort, reduce compliance and can prevent mobility of the patient as recovery progresses after surgery. It would be desirable to overcome the disadvantages of such known devices with a compression apparatus that employs a fluid connector apparatus in accordance with the principles of the present disclosure. SUMMARY U.S. patent application Ser. No. ______, filed on Feb. 23, 2004 and entitled Compression Apparatus, the contents of which being hereby incorporated by reference herein in its entirety, discloses an exemplary sequential compression apparatus that overcomes the disadvantages and drawbacks of the prior art by reducing bulk and improving comfort and compliance to a patient. This sequential compression apparatus includes a removable portion of a compression sleeve (wraparound pad) and a valve connector that facilitates coupling of the removable portion from a pressurized fluid source. In the sequential compression apparatus, a predetermined fluid pressure is supplied to each of a plurality of tubes to the apparatus according to a predetermined timing sequence. Fluid pressure feedback information is acquired to ensure proper operation of the apparatus. Closure of a valve in the valve connector prevents fluid leakage when the removable portion and corresponding tube is disconnected and removed. Valve connectors heretofore known either completely open or completely close a fluid conduit. The open or closed fluid conduit has pneumatic characteristics different from those of the previously connected system components. In an illustrative apparatus, a controller recognizes a pressure change indicating closure of the valve connector when the removable portion is removed. The controller then begins executing a second predetermined pressure timing sequence to supply pressurized fluid to the remaining portions of the apparatus. If the valve connector is not present or malfunctions when the removable portion is removed, the controller recognizes a pressure change indicating an open fluid line and can execute an error or alarm program sequence (see, for example, the controller described in U.S. patent application Ser. No. ______, filed on Feb. 23, 2004 and entitled Compression Treatment System, the entire contents of which is hereby incorporated by reference herein). Use of such valve connectors thus disadvantageously requires a more complicated control element in the fluid supply apparatus which must be capable of executing a plurality of pressure/timing sequences in response to acquired pressure measurements. In the illustrative apparatus, switching between multiple control sequences disadvantageously requires interruption of the system and can require manual input to initiate the second pressure/timing sequence. It would be desirable to overcome the drawbacks of heretofore known fluid line connectors by providing a coupling valve that allows a controller to continue uninterrupted operation of a single pressure timing sequence when a removable portion is disconnected from a controlled pressure system. It would be further desirable to accommodate such uninterrupted operation of a single control sequence by providing a coupling valve that approximates the pneumatic characteristics of a removable portion of controlled pressure system. It would be desirable to provide such a connector that is inexpensive to manufacture and configured for use in a prophylaxis sequential compression apparatus. Accordingly, a fluid conduit connector apparatus is provided that facilitates uninterrupted execution of a single pressure timing sequence when a fluid conduit is removed from a pneumatic system. The fluid conduit connector apparatus overcomes the disadvantages and drawbacks of the prior art when incorporated in a prophylaxis sequential compression apparatus by reducing control system complexity, providing ease of use and minimizing interruption to patients. Desirably, the fluid conduit connector apparatus includes a port portion including a valve to achieve the advantages of the present disclosure. Most desirably, the fluid conduit connector apparatus has a valve that approximates the pneumatic characteristics of a removed pneumatic system component. The fluid conduit connector apparatus is easily and efficiently fabricated. The fluid conduit connector apparatus, in accordance with the principles of the present disclosure, is adapted for use with a compression apparatus. The fluid connector apparatus includes a connector having a plurality of fluid ports formed therewith that facilitates fluid communication between a plurality of fluid conduits of the compression apparatus and a pressurized fluid source. Each of the plurality of fluid ports defines a fluid orifice configured for fluid flow. A valve is disposed with one of the fluid ports. The valve is operable to engage the fluid port such that disconnect of a fluid conduit of the compression apparatus corresponding to the fluid port from the connector reduces a dimension of the fluid orifice of the fluid port. The fluid connector apparatus can include a first connector having a first plurality of fluid ports formed therewith that fluidly communicates with a first plurality of fluid conduits. In an illustrative embodiment, the first plurality of fluid conduits is a set of three air tubes. A valve is supported with the first connector and is movable such that upon disconnection of one of the first plurality of fluid conduits from the first connector, the valve engages a corresponding fluid port in a configuration that creates a reduced fluid orifice therein. The valve is adapted to approximate pneumatic characteristics of a connected apparatus when the connected apparatus is disconnected from the first connector. In another embodiment, one of the fluid ports includes a coupling port and one of the first plurality fluid conduits includes a quick-disconnect fitting adapted for removable mating with the coupling port. The valve is disposed in the coupling port and can, for example, include a spring loaded plunger. An illustrative coupling fitting includes an engagement portion extending therefrom. The spring loaded plunger is displaced by the engagement portion when the coupling fitting is mated to the coupling port. In one embodiment, the coupling port includes a cap portion disposed therein. The spring loaded plunger engages the cap portion to create an orifice that provides a pneumatic behavior approximating one of the first plurality of fluid conduits when the coupling fitting is disconnected from the coupling port. In an illustrative embodiment, the fluid connector apparatus according the present disclosure also includes a second connector in fluid communication with a second plurality of fluid conduits. In an exemplary embodiment, the second plurality of fluid conduits is a set of three air tubes. A plurality of couplings is in fluid communication with the air tubes. The first connector includes a sleeve defining a cavity adapted for mating with the plurality of couplings. The cavity defines a female mating receptacle. The plurality of couplings defines a male mating plug adapted for mating with the female mating receptacle. In certain embodiments, the first and/or second connectors include improved streamlining of their outer surfaces to prevent snagging of the connectors on patient garments and bedding. In one embodiment, the first connector includes an interference key in the cavity to prevent the first connector from mating with legacy connector components. The second connector includes a clearance space for the interference key. In yet another embodiment, the first plurality of fluid conduits is a set of webbed tubing having increased webbing volume between at least one pair of adjacent conduits. At least one interference rib is formed between at least one pair of adjacent fluid ports in the first plurality of fluid ports. The increased webbing volume is aligned with the interference rib if the plurality of fluid conduits is improperly oriented with said first connector. The interference rib thereby prevents attachment of improperly oriented fluid conduits to the first connector. Similarly, the second plurality of fluid conduits can include an increased webbing volume configured to interfere with an interference rib between adjacent ports in the second connector to prevent attachment of improperly oriented fluid conduits to the second connector. In one embodiment of the present disclosure, the fluid conduit connector apparatus further includes a gasket disposed in the cavity. The gasket is adapted to provide fluid sealing between the first and second connectors when the first and second connectors are mated together. In at least one embodiment, the sleeve includes a window extending at least partially therethrough. The second connector includes a locking arm extending therefrom. The locking arm is adapted to engage the window to releasably retain the first connector with the second connector. The sleeve can include a slot extending to the window which partially bifurcates the sleeve to define opposing snap arms for engaging the locking arm. One of the first or second connectors can include an alignment slot and the other of the first or second connectors can include an alignment rib configured for engaging the alignment slot. In a particular illustrative embodiment, the locking arm includes a leading surface inclined at a first angle to provide a predetermined engagement force between the locking arm and snap arms, and a trailing surface inclined at a second angle to provide a predetermined disengagement force between the locking arm and snap arms. The predetermined engagement force can be designed, for example, to be less than the predetermined disengagement force. In another embodiment of the present disclosure, a fluid connector apparatus includes a first connector having tubular walls defining a plurality of fluid ports adapted to connect to a first plurality of fluid conduits. At least one of the fluid ports comprises a coupling port. At least one of the first plurality of fluid conduits includes a coupling fitting adapted for removable mating with the coupling port. A valve is disposed within the coupling port. The valve engages the coupling port to create an orifice approximating pneumatic behavior of one of the first plurality of conduits when the coupling fitting is disconnected from said coupling port. A second connector is adapted to connect to a second plurality of fluid conduits and mate with the first connector. In an exemplary embodiment, the valve includes a spring loaded plunger disposed in the coupling port. In one embodiment, the coupling fitting includes an engagement portion extending therefrom. The spring loaded plunger is displaced by the engagement portion when the coupling fitting is mated to said coupling port. The coupling port includes a cap portion disposed therein. The spring loaded plunger engages the cap portion to create an orifice that provides a pneumatic behavior approximating said one of the first plurality of fluid conduits when the coupling fitting is disconnected from the coupling port. In another embodiment of the fluid connector apparatus, the second connector comprises a plurality of couplings in fluid communication with the second plurality of fluid conduits. The first connector includes a sleeve formed therewith defining a cavity adapted for mating with the plurality of couplings. The sleeve includes a window extending at least partially therethrough. The second connector includes a locking arm extending therefrom which is adapted to engage the window to releasably retain the first connector with the second connector. The sleeve includes a slot extending to the window and partially bifurcating the sleeve to define opposing snap arms for engaging the locking arm. A particular embodiment of the present disclosure a fluid connector apparatus includes a sleeve connector having tubular walls defining a plurality of fluid ports adapted to connect to a first tubing set including an ankle tube, a calf tube and a thigh tube. One of the ports includes a coupling port. The thigh tube has a coupling fitting adapted for removable mating with the coupling port. In the particular embodiment, a valve is disposed within the coupling port. The valve includes a spring loaded plunger which engages the coupling port to create an orifice approximating pneumatic behavior of the thigh tube when the fitting is disconnected from the coupling port. The coupling fitting includes an engagement portion extending therefrom. The spring loaded plunger is displaced by the engagement portion when the coupling fitting is mated to the coupling port. The coupling port includes a cap portion disposed therein. The spring loaded plunger engages the cap portion to create an orifice that provides pneumatic behavior approximating the thigh tube when the coupling fitting is disconnected from the coupling port. A tubing set connector can be adapted to connect to a second tubing set and mate with the sleeve connector. The tubing set connector includes a plurality of couplings in fluid communication with the second tubing set. The sleeve connector includes a sleeve formed therewith defining a cavity adapted for mating with the plurality of couplings, and having a gasket disposed in the cavity. The gasket is adapted to provide fluid sealing between the sleeve connector and the tubing set connector. In at least one embodiment, the gasket includes a retention portion extending therefrom. The sleeve includes a gasket retention groove adapted to accept the retention portion and thereby retain the gasket to the sleeve. In a particular embodiment, the sleeve includes a window extending at least partially therethrough. The tubing set connector includes a locking arm extending therefrom. The locking arm is adapted to engage the window to releasably retain the sleeve connector with the tubing set connector. The sleeve includes a slot extending to the window and partially bifurcating the sleeve to define opposing snap arms for engaging the locking arm. One of the sleeve connector or the tubing set connector includes an alignment slot and the other of the sleeve connector or the tubing set connector includes an alignment rib configured for engaging the alignment slot. In another embodiment, the present application discloses a coupling apparatus including a coupling fitting permanently mounted to a first end of a fluid conduit. A second end of the fluid conduit is connected to an inflatable device. A coupling port is adapted for mating with the coupling fitting and includes a valve supported with the coupling port. The valve approximates pneumatic characteristics of the inflatable device and fluid conduit when the coupling fitting is disconnected from the coupling port. In another particular embodiment, the coupling fitting can include a proximal cylinder and a distal cylinder extending therefrom. A central longitudinal axis extends through the proximal cylinder and distal cylinder. The proximal cylinder has an inside diameter approximately equal to the outside diameter of said fluid conduit to facilitate an interference fit therebetween. The distal cylinder has an inside diameter approximately equal to the outside diameter of said coupling port to facilitate a slip fit therebetween and includes a locking tab extending radially from the outer surface of the distal cylinder. The coupling port includes a fluid communication channel and is incorporated with a sleeve having a detent for engaging the locking tab to removably secure the coupling fitting to the coupling port. Alternatively, the sleeve or interior surface of the first connector can include a detent cavity extending at least partially into the interior surface and adapted for accepting the locking tab. An exemplary detent cavity includes a longitudinal track portion adapted for guiding the locking tab during engagement and disengagement and an annular portion adapted for retaining the locking tab when the coupling fitting is rotated about its longitudinal axis. Along its length, the detent cavity can have varying depth or width into the interior surface. The varying depth of the detent cavity provides a predetermined engagement/disengagement force/displacement profile between the locking tab and the detent cavity. In one embodiment, the locking tab has an outer portion with an enlarged manual engagement surface to assist manipulation of the locking tab. In an illustrative embodiment, the valve includes a spring loaded plunger. The spring is compressed by engagement between the coupling fitting and the plunger to open the coupling port for fluid communication when the coupling fitting is connected to the coupling port. The spring is extended to force the plunger into the channel. The plunger is perforated to provide a predetermined fluid resistance through the channel when the coupling fitting is disconnected from the coupling port. In another embodiment, the present disclosure provides a fluid connector apparatus including a first connector having a first plurality of fluid ports formed therewith which fluidly communicate with a first plurality of fluid conduits. A second connector is in fluid communication with a second plurality of fluid conduits and includes a plurality of couplings in fluid communication therewith. Restrictor means within the first connector are provided for approximating pneumatic characteristics of one of the fluid conduits when it is disconnected from the first connector. In yet another embodiment, the present disclosure provides a method of coupling a pressure source to a pneumatic device. According to the method of the present disclosure, a first plurality of fluid conduits from the pneumatic device is connected to a second plurality of conduits from the pressure source using a multi-port tube connector. One of the first plurality of conduits is disconnected from the multi-port tube connector. A valve is thereby released in the connector which approximates the pneumatic characteristics of one of the first plurality of conduits. Another illustrative embodiment of the present disclosure provides a fluid conduit coupling. The fluid conduit coupling has a coupling fitting with a proximal cylinder and a distal cylinder monolithically formed with the proximal cylinder along a central longitudinal axis. The proximal cylinder has an inside diameter adapted for receiving a fluid conduit. The fluid conduit coupling also includes a fluid port having a male cylindrical portion extending proximally therefrom and a fluid channel extending through the port from the male cylindrical portion to a distal opening. The distal cylinder of the coupling fitting includes a female orifice adapted for mating with the male cylindrical portion of the coupling port. A valve disposed in the port is operatively configured to approximate pneumatic characteristics of a disconnected device when the coupling fitting is detached from the coupling port. The coupling fitting of the fluid conduit coupling according to the illustrative embodiment has an engagement portion adapted to displace the valve in the coupling port. The valve includes plunger biased proximally by a spring force. The engagement portion is aligned to displace the plunger distally against said spring force when the fitting is attached to the port. The plunger providing an increased fluid passage when displaced distally and a reduced fluid passage when biased proximally. BRIEF DESCRIPTION OF THE DRAWINGS The objects and features of the present disclosure, which are believed to be novel, are set forth with the particularity in the appended claims. The present disclosure, both as to its organization and manner of operation, together with further objectives and advantages, may be best understood by reference to the following description, taken in connection with the accompanying drawings, which are described below. FIG. 1 is a perspective view of an illustrative embodiment of a fluid conduit connector apparatus in accordance with the principles of the present disclosure; FIG. 2 is a perspective view of a first and second connector according to an illustrative embodiment of the fluid conduit connector apparatus of the present disclosure; FIG. 3 is a side partial cross-sectional view of the illustrative fluid conduit connector apparatus shown in FIG. 1; FIG. 4 is a top cross sectional view of the illustrative fluid conduit connector apparatus shown in FIG. 1; FIG. 5 is front cross sectional view of the coupling port in an illustrative fluid conduit connector apparatus according to the present disclosure; FIG. 6 is a side cross sectional perspective view of the fluid conduit connector apparatus according to an illustrative embodiment of the present disclosure; FIG. 6A is a cutaway perspective view of the fluid conduit connector apparatus shown in FIG. 6; FIG. 6B is a cutaway perspective view of the fluid conduit connector apparatus shown in FIG. 6; FIG. 7 is an exploded view of the various components of an illustrative fluid conduit connector apparatus according to the present disclosure; FIG. 8 is an exploded view of the various components of an illustrative first connector in a fluid conduit connector apparatus according to the present disclosure; FIG. 8A is a perspective view of an alternate embodiment of the first connector shown in FIG. 8; FIG. 8B is a perspective view of the first connector shown in FIG. 8A and an alternate embodiment of the second connector shown in FIG. 2; FIG. 8C is a cross-sectional plan view of the first connector and the second connector shown in FIG. 8B; FIG. 9 is a side view of an illustrative coupling fitting according to the present disclosure; FIG. 10 is a top view of a first or second connector including a detent cavity according to an illustrative embodiment of the present disclosure; FIG. 11 is a front view of a first or second connector including an interference rib according to an illustrative embodiment of the present disclosure; FIG. 12 is a front view of webbed tubing having an increased webbing volume according to an illustrative embodiment of the present; FIG. 13 is an end view of a first or second connector including an interference key according to an illustrative embodiment of the present disclosure; and FIG. 14 is a schematic view of two embodiments of a first connector and two embodiments of a second connector. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS The exemplary embodiments of the fluid conduit connector apparatus and methods of operation disclosed are discussed in terms of prophylaxis compression apparatus and vascular therapy including a prophylaxis compression apparatus for application to a limb of a body and more particularly in terms of a compression apparatus having removable portions. It is envisioned that the present disclosure, however, finds application with a wide variety of pneumatic systems having removable fluid conduits, such as, for example, medical and industrial applications requiring timed sequences of compressed air in a plurality of air tubes. In the discussion that follows, the term “proximal” refers to a portion of a structure that is closer to a torso of a subject and the term “distal” refers to a portion that is further from the torso. As used herein the term “subject” refers to a patient undergoing vascular therapy using the prophylaxis sequential compression apparatus. According to the present disclosure, the term “practitioner” refers to an individual administering the prophylaxis sequential compression apparatus and may include support personnel. The following discussion includes a description of the fluid conduit connector apparatus, followed by a description of an exemplary method of operating the fluid conduit connector apparatus in accordance with the principals of the present disclosure. Reference will now be made in detail to the exemplary embodiments and disclosure, which are illustrated with the accompanying figures. Turning now to the figures, wherein like components are designated by like reference numerals throughout the several views. Referring initially to FIGS. 1 and 2, there is illustrated a fluid conduit connector apparatus 10, constructed in accordance with the principals of the present disclosure. The fluid conduit connector apparatus 10 includes a connector having a first connector 12 and second connector 14. First connector 12 is configured for removable engagement with a second connector 14. The first connector 12 includes a first plurality of fluid ports 16 extending proximally therefrom and adapted for receiving a first plurality of fluid conduits 18. Fluid conduits 18 are connected to a compression apparatus, including for example, a compression sleeve (not shown) adapted for disposal and treatment about a limb of a subject (not shown). The second connector 14 includes a second plurality of fluid ports 20 extending distally therefrom and adapted for receiving a second plurality of fluid conduits 22. Fluid conduits 22 fluidly communicate with a pressurized fluid source (not shown) that is adapted to inflate the compression sleeve via the advantageous configuration of fluid conduit connector apparatus 10, as described in accordance with the principles of the present disclosure. It is envisioned that conduits 18, 22 may include various tubing such as, for example, non-webbed tubing, etc. The fluid ports 16, 20 of connectors 12, 14 respectively, each define an inner fluid orifice or passageway that facilitate fluid communication between connectors 12, 14. In turn, connectors 12, 14 facilitate fluid communication between the pressurized fluid source and the compression sleeve. Although the fluid conduit connector apparatus 10 is illustrated as having a set of three fluid ports in each connector for connecting sets of three fluid conduits, it is contemplated that each connector can have any number of fluid ports without departing from the scope of the present disclosure. The first connector 12 includes a sleeve 24 defining a cavity 26 having a distal opening. The cavity 26 houses distal portions of the first plurality of fluid ports 16 which extend distally within the cavity 26. The second connector 14 includes a plurality of fluid couplings 28 extending proximally therefrom. The plurality of fluid couplings 28 is formed by proximal portions of the second plurality of fluid ports 20 for alignment with the distal portions of the first plurality of fluid ports 16. A locking arm 30 extends proximally from the body portion 32 of the second connector 14. A slot 34 in the sleeve 24 of first connector 12 includes a window 36 adapted for removably accepting the locking arm 30 to retain the first connector 12 to the second connector 14. At least one of the first plurality of ports is a coupling port 38 adapted for receiving a coupling fitting 40. The coupling fitting 40 is permanently attached to the distal end of a corresponding one of the first plurality of fluid conduits 18. A locking tab extending radially from the coupling fitting 40 is configured for engaging a detent cavity 44 in the first connector 12, for example in the sleeve 24 as shown in FIG. 1. A streamlined outer surface 25 prevents the connectors from snagging on patient clothing or bedding. Referring now to FIGS. 3-7, the various components of the fluid conduit connector apparatus will be described in further detail. A gasket 46 conforms to the space between the plurality of couplings 28 and the distal portion of the first plurality of fluid ports 16 within the cavity 26 when the first 12 is engaged with the second connector 14. The gasket 46 provides sealing for pressurized fluid communication between corresponding fluid conduits by providing a sealed fluid channel including the first plurality of fluid ports and second plurality of fluid ports. It is envisioned that the gasket 46 can be efficiently and inexpensively manufactured using a variety of common materials or fabrication methods, for example by injection molding an elastomeric material or dye cutting a cork or paper based gasket material. It is envisioned that the gasket 46 can be configured for retention to one or the other of the first connector 12 and second connector 14. In the illustrative embodiment, the gasket includes a proximal lip 48 configured to engage the distal portion of each of the first plurality of fluid ports to provide fluid sealing between the first connector 12 and the second connector 14. The gasket includes a retention portion extending therefrom. The sleeve 24 includes a gasket retention groove adapted to accept the retention portion and thereby retain the gasket to the sleeve 24 when the second connector 14 is removed therefrom. The slot 34 at least partially bifurcates the sleeve 24 to allow spreading of the sleeve 24 under stress when the locking arm 30 is pressed into the slot 34 at its distal end as the first connector 12 is mated to the second connector 14. When an engagement portion 48 of the locking arm 30 reaches the window portion 36 of the slot 34 the sleeve returns to its relaxed shape to releasably retain the second connector 14 by its locking arms 30. The locking arm 48 is formed with a leading surface 39 inclined at an angle (i.e., first angle) and a trailing surface 41 inclined at a second angle. In the illustrative embodiment, the leading surface 39 is inclined at a shallower angle than the trailing 41 surface so that the force to connect the first connector 12 to the second connector 14 is lighter than the force to disconnect the first connector 12 from the second connector 14. Predetermined connection/disconnection forces can thereby be achieved by proper selection of the first and second angle when designing a particular locking arm 48. Although the illustrative embodiment described herein refers to a particular locking arm and slot configuration, it is envisioned that virtually any type of removable retention method may be used to removably retain the first connector to the second connector without departing from the scope of the present disclosure. For example, an interference fit may be provided between the first connector 12 and second connector 14 or may be provided by a properly configured deformable gasket 46. Alternatively, a snap or detent arrangement known in the art may be used to retain the first connector 12 to the second connector 14. For example, as shown in FIGS. 8A, 8B and 8C, first connector 12 includes a locking arm 234 that is configured for mating engagement with corresponding slot 230 formed in second connector 14, similar to the arm and slot structure described. An alignment rib 59 (FIG. 1) extends radially from at least one of the plurality of couplings 28 along its longitudinal axis. A corresponding alignment slot (not shown) is provided in the inner surface of the sleeve 24 extending to the distal end thereof for accepting the alignment rib 59. It is contemplated that virtually any type of alignment rib/slot configuration commonly used in the art of for alignment of mating connectors can be used without departing from the scope of the present disclosure. The coupling fitting 40 includes a proximal cylinder 52 and a distal cylinder 54 aligned along a longitudinal axis 56. The proximal cylinder 52 includes a proximal opening 58 and an inside diameter 60 defining an inner surface 62 configured for a press fit corresponding to the outside diameter of one of the first plurality of fluid conduits 18. In the illustrative embodiment, the corresponding fluid conduit is an air tube which is press fit into the proximal cylinder 52 through its proximal opening 58. In an illustrative embodiment, the fluid conduit is substantially permanently attached to the proximal cylinder 52 by friction. In alternative embodiments a variety of suitable adhesives may be applied to the inner surface 62 of the proximal cylinder 52 to permanently attach the fluid conduit and provide a fluid tight seal therebetween. For example, it is envisioned that a silicon adhesive, rubber cement, a material specific adhesive compound, an o-ring, a gasket or the like can be used according to methods well known in the art to attach the fluid conduit to the coupling fitting. The distal cylinder 54 comprises an inner surface defined by an inside contour 64 revolved about the longitudinal axis 56 and an outer surface 66 defined by an outside diameter. In the illustrative embodiment, the inside contour 64 includes a sealing portion 68, a flexing portion 70 and an annular lip portion 72. The sealing portion 68 has an inside diameter adapted for a tight fit against the outside surface of the coupling port 38 to provide at least partial fluid sealing therebetween. The annular lip portion 72 defines an annular ring that compresses against the outside surface of coupling port 38 and provides fluid sealing therebetween. The flexing portion 70 is defined by a reduced wall thickness which allows the distal cylinder 54 to deflect inwardly to facilitate engagement of the locking tab 42 to the detent cavity 44. Although the illustrative embodiment is described with respect to a particular retention and sealing configuration between the coupling fitting 40 and coupling port 38, it is envisioned that virtually any type of coupling fitting retention and sealing method known in the art can be used between the coupling fitting 40 and the external surface of the coupling port 38 without departing from the scope of the present disclosure. For example, it is envisioned that a threaded collar, a cantilever snap arm or the like can be used for attachment of the coupling fitting 40 to the coupling port 38 or to the first connector 12. In another example referring to FIGS. 9 and 10, the sleeve 24 or interior surface of the first connector 12 can include a detent cavity 44 extending at least partially into the interior surface and adapted for accepting the locking tab 42 of the coupling fitting 40. A detent 57 of tab 42 is inserted into sleeve 24 to become disposed in cavity 44. Detent 57 is rotated through cavity 44, via manipulation of fitting 40 and retained in position by bump formed in the wall of cavity 44. In an alternate embodiment, the detent cavity shown in FIG. 10 includes a longitudinal track portion 55 (shown in phantom) adapted for guiding the locking tab 42 (FIG. 9) during engagement and disengagement and an annular portion 57 adapted for retaining the locking tab 42 (FIG. 9) when the coupling fitting 40 is rotated about its longitudinal axis 56. Along its length, the detent cavity 44 can have varying depth or width into the interior surface. The varying depth of the detent cavity 44 provides a predetermined engagement/disengagement force/displacement profile between the locking tab 42 and the detent cavity. In one embodiment, the locking tab has an outer portion with an enlarged manual engagement surface 43 to assist manipulation of the locking tab 42. In an illustrative embodiment of the invention, the coupling fitting includes an engagement portion 74 adapted for opening a valve 76 disposed within the coupling port 38. The engagement portion 74 extends distally from a transverse wall 78 within the coupling fitting 40 to displace a plunger 80 in the valve 76. In the illustrative embodiment, the transverse wall 78 is disposed within the coupling fitting 40 about between the proximal cylinder 52 and the distal cylinder 54 and orthogonal to the longitudinal axis 56. At least one fluid passageway extends through the transverse wall. Although the illustrative embodiment is described in terms of a distally extending engagement portion, it is envisioned that virtually any type of valve engagement structure can be used to displace a valve plunger 80 within the scope of the present disclosure. For example, a flat surface of the transverse wall 78 or a rib extending from the inner surface of the distal cylinder 54, can be aligned with a complementary structure within a valve 76 to displace a valve plunger 80 when the coupling fitting 40 is engaged with the coupling port 38. The illustrative embodiment includes a valve 76 is disposed within the coupling port 38. The valve 76 includes a plunger 80 movable along the longitudinal axis of the coupling port 38 and biased proximally by a spring 82. The spring 82 is supported by the gasket 46 which is held in place in cavity 26 by protrusion 51 on the gasket 46. Adhesive may alternatively be used to maintain gasket 46 in position. The gasket 46 includes a spring seat formed along the longitudinal axis of any gasket passageway to be aligned with a coupling port. (FIGS. 4-5) The spring seat in the illustrative embodiment includes a central stub 84 supported by radial spars 86 within the gasket opening. The valve can be easily assembled by installing the spring 82 over the distal end of the plunger 80 to form a plunger and spring sub-assembly. The plunger 80 includes a step 88 to engage the proximal end of the spring 82. The plunger and spring sub-assembly can then be installed into the coupling port 38 from its proximal end. The gasket 46 can then be installed into the cavity 26. Alternatively, the plunger and spring sub-assembly can be installed to the gasket 46 by fitting the spring 82 to the spring seat before installing the gasket 46 spring 82 and plunger 80 together to the first connector 12. FIGS. 7 and 8 provide two illustrative embodiments of a plunger 80 according to the present disclosure. Although the present disclosure illustrates the use of a coil spring 82 to bias the plunger 80, it is contemplated that virtually any type of plunger and spring arrangement known in the art can be used to provide biasing of the plunger 80 within the scope of the present disclosure. For example, it is envisioned that spring force could be applied to the plunger 80 by forming a plastic cantilever spring arm that could be formed within the first connector 12. Alternatively a structure similar to the spring seat could be formed of elastomeric material as part of the gasket 46 to provide a biasing force to the plunger 80 without departing from the scope of the present disclosure. When the coupling fitting 40 is engaged with the coupling port 38, the engagement portion 74 of the coupling fitting forces the plunger 80 to move distally against the force of the spring 82 which is thereby compressed. An open fluid connection is thereby provided from the fluid conduit connected to the coupling fitting 40, through the coupling port 38 to the corresponding one of the second plurality of fluid conduits 22, i.e., the corresponding air tube. For example, a portion of the compression sleeve that fluidly communicates with the pressurized fluid source via coupling port 38 may be removed from the remainder of the compression sleeve. The remaining portion of the compression sleeve continues to provide treatment to the limb of the subject. Upon removal of the selected portion, the coupling fitting 40 is disconnected and not engaged to the coupling port 38. Spring 82 forces the plunger 80 to its proximal limit of travel where the plunger 80 engages a proximal stop such that valve 76 is in a closed position. The plunger 80 is configured to cooperate with an internal structure in the coupling port 38 to define a reduced fluid orifice when the plunger 80 is displaced to its proximal limit. The reduced fluid orifice is designed to provide pneumatic characteristics approximating the pneumatic characteristics of a detached device. In an illustrative embodiment, (FIGS. 6-7), a cap 90 having a fluid passageway 92 therethrough is disposed in the proximal opening of the coupling port 38. The cap 90 provides a stop defining a proximal limit of plunger travel and is configured to cooperate with the plunger 80 of valve 76, such that valve 76 reduces the dimension of the fluid orifice of coupling port 38. For example, as shown in FIGS. 6A and 6B, coupling fitting 40 is connected to the coupling port 38 to force plunger 80 distally and open the fluid connection (FIG. 6A), described above, for inflating a removable portion of an inflatable compression sleeve (not shown). To provide such an open connection, a valve seat 282 of plunger 80 is disposed via spring 82 (not shown in FIGS. 6A and 6B for clarity), out of engagement with a conical seat 284 of cap 90. This configuration allows air to flow around the conical seat 284 and through conduit 22 (not shown), and out to the inflatable removable portion of the compression sleeve, as shown by arrows A. For removal of the removable portion of the compression sleeve, coupling fitting 40 is removed from coupling port 38. Spring 82 forces valve seat 282 into engagement with a counter bore edge of conical seat 284. Thus, this configuration advantageously reduces the dimension of the fluid orifice of coupling port 38 such that air only flows through cavities defined by semi-circular slots 286 of valve seat 282 and the bore edge of conical seat 284. Slots 286 are formed on the sides of valve seat 282. The cavities defined by slots 286 and conical seat 284 facilitate fluid flow that approximates the pneumatic behavior of the removable portion of the compression sleeve when coupling fitting 40 is connected to coupling port 38 during an open fluid connection. The cavities defined by slots 286 and conical seat 284 may have various configurations and dimensions including geometries such as, for example, elliptical, polygonal, etc. This configuration advantageously approximates the pneumatic characteristics of a detached device. It is contemplated that the fluid orifice of coupling port 38 may be variously configured such that corresponding engagement with plunger 80 reduces the orifice dimension to approximate fluid flow through coupling port 38 that would otherwise occur with valve 76 in the open position. It is further contemplated that plunger 80 may includes openings to approximate fluid flow. It is envisioned that valve 76 is operable to reduce the dimension of the fluid orifice of coupling port 38 over a range of closed positions, including partial fluid flow, leakage, etc. to approximate fluid in the port or alternatively, the orifice may completely close to prevent fluid flow through the corresponding port. In a completely closed configuration, pump speed or other settings may be adjusted. In a particular embodiment, the present disclosure provides an air tubing connector for use with a compression apparatus having removable portions, see, for example, the compression sleeve described in U.S. patent application Ser. No. ______, filed on Feb. 23, 2004 and entitled Compression Apparatus. Three separate air tube are connected to an ankle portion, a calf portion and a knee portion of the apparatus. Each portion is supplied with a timed sequence of compressed air through its respective air tube. The proximal end of each of the three air tubes is connected to the first plurality of fluid ports 16 in a first connector 12 according to the present disclosure. A mating set of three air tubes extends from a timed pressure source and is connected to the second plurality of fluid ports 18 in a second connector 14 according to the present disclosure. In the illustrative embodiment, the distal end of the thigh tube is connected to the first connector 12 via a coupling fitting 40 and port 38 as described hereinbefore. When a patient no longer requires the thigh portion of the prophylaxis compression apparatus, the thigh portion can be removed and the tubing attached thereto can be disconnected from the first connector at the coupling port 38. Operation of the valve 76 in the coupling port 38 provides a reduced fluid orifice that restricts airflow therethrough to approximate the pneumatic characteristics of the thigh portion and its corresponding air tube. Thus, sensors in the timed pressure source will not detect a change in fluid pressure or flow rate when the thigh portion is removed. This allows the timed pressure source to continue supplying uninterrupted timed air pressure to the ankle and calf portions of the prophylaxis compression apparatus. Referring to FIGS. 11 and 12, certain embodiments are provided wherein the first plurality of fluid conduits 18 is a set of webbed tubing 98 having increased webbing volume 100 between at least one pair of adjacent conduits. At least one interference rib 94 is formed between at least one pair of adjacent fluid ports in the first plurality of fluid ports. The increased webbing volume 100 is aligned with the interference rib 94 if the set of webbed tubing 98 is improperly oriented with the first connector 12. The interference rib 94 thereby prevents attachment of improperly oriented fluid conduits to the first connector 12. Similarly, the second plurality of fluid conduits 22 can include an increased webbing volume configured to interfere with an interference rib between adjacent ports in the second connector 14 to prevent attachment of improperly oriented fluid conduits to the second connector 14. Referring to FIG. 13, one embodiment includes a first connector 12 having an interference key 96 in the cavity 26 to prevent the first connector 12 from mating with legacy connector components. The second connector 14 includes a clearance space for the interference key 96. FIG. 14 schematically depicts the function of an interference key 96 to prevent connection of certain embodiments of a first connector 12 to certain embodiments of a second connector 13. For example, key slot 98 in second connector 13B provides clearance for interference key 96 in first connector 12B to facilitate mating one to the other. Second connector 13B can also be mated to certain first connectors such as 12A which do not include an interference key. Second connector 13A does not include a key slot and therefore can not be mated with first connector 12B. In at least one embodiment, second connector 13A is a legacy connector. In the illustrative embodiment, the interference key 96 in a non-compatible connector such as first connector 12B is used to prevent connection of the non-compatible connector to the legacy connector. It will be understood that various modifications may be made to the embodiments disclosed herein. For example, the connector of the present disclosure may be used with various single and plural bladder compression sleeve devices including, for example, the compression sleeve described in U.S. patent application Ser. No. ______, filed on Feb. 23, 2004 and entitled Compression Apparatus, the entire contents of which is hereby incorporated by reference herein. Therefore, the above description should not be construed as limiting, but merely as exemplification of the various embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto. | <SOH> BACKGROUND <EOH>1. Technical Field The present disclosure generally relates to the field of fluid conduit connectors for application to multiple fluid line systems and more particularly to fluid line connectors having a valved port. 2. Description of the Related Art Medical conditions that form clots in the blood, such as deep vein thrombosis (DVT) and peripheral edema, are a major concern to immobile medical patients. Such patients include those undergoing surgery, anesthesia, extended periods of bed rest, etc. These blood clotting conditions generally occur in the deep veins of the lower extremities and/or pelvis. These veins, such as the iliac, femoral, popiteal and tibial return deoxygenated blood to the heart. When blood circulation in these veins is retarded due to illness, injury or inactivity, there is a tendency for blood to accumulate or pool. A static pool of blood provides an ideal environment for dangerous clot formations. A major risk associated with this condition is interference with cardiovascular circulation. Most seriously, a fragment of the blood clot can break loose and migrate. A pulmonary emboli can form a potentially life-threatening blockage in a main pulmonary artery. The conditions and resulting risks associated with patient immobility can be controlled or alleviated by applying intermittent pressure to a patient's limb to assist in blood circulation. Known devices such as one piece pads and compression boots have been employed to assist in blood circulation. See, for example, U.S. Pat. Nos. 6,290,662 and 6,494,852. Sequential compression devices have been used, which consist of an air pump connected to a disposable wraparound pad by a series of fluid conduits such as air tubes, for example. The wraparound pad is placed around the patient's leg. Air is then forced into different parts of the wraparound pad in sequence, creating pressure around the calves and improving venous return. These known devices suffer from various drawbacks due to their bulk and cumbersome nature of use. These drawbacks cause patient discomfort, reduce compliance and can prevent mobility of the patient as recovery progresses after surgery. It would be desirable to overcome the disadvantages of such known devices with a compression apparatus that employs a fluid connector apparatus in accordance with the principles of the present disclosure. | <SOH> SUMMARY <EOH>U.S. patent application Ser. No. ______, filed on Feb. 23, 2004 and entitled Compression Apparatus, the contents of which being hereby incorporated by reference herein in its entirety, discloses an exemplary sequential compression apparatus that overcomes the disadvantages and drawbacks of the prior art by reducing bulk and improving comfort and compliance to a patient. This sequential compression apparatus includes a removable portion of a compression sleeve (wraparound pad) and a valve connector that facilitates coupling of the removable portion from a pressurized fluid source. In the sequential compression apparatus, a predetermined fluid pressure is supplied to each of a plurality of tubes to the apparatus according to a predetermined timing sequence. Fluid pressure feedback information is acquired to ensure proper operation of the apparatus. Closure of a valve in the valve connector prevents fluid leakage when the removable portion and corresponding tube is disconnected and removed. Valve connectors heretofore known either completely open or completely close a fluid conduit. The open or closed fluid conduit has pneumatic characteristics different from those of the previously connected system components. In an illustrative apparatus, a controller recognizes a pressure change indicating closure of the valve connector when the removable portion is removed. The controller then begins executing a second predetermined pressure timing sequence to supply pressurized fluid to the remaining portions of the apparatus. If the valve connector is not present or malfunctions when the removable portion is removed, the controller recognizes a pressure change indicating an open fluid line and can execute an error or alarm program sequence (see, for example, the controller described in U.S. patent application Ser. No. ______, filed on Feb. 23, 2004 and entitled Compression Treatment System, the entire contents of which is hereby incorporated by reference herein). Use of such valve connectors thus disadvantageously requires a more complicated control element in the fluid supply apparatus which must be capable of executing a plurality of pressure/timing sequences in response to acquired pressure measurements. In the illustrative apparatus, switching between multiple control sequences disadvantageously requires interruption of the system and can require manual input to initiate the second pressure/timing sequence. It would be desirable to overcome the drawbacks of heretofore known fluid line connectors by providing a coupling valve that allows a controller to continue uninterrupted operation of a single pressure timing sequence when a removable portion is disconnected from a controlled pressure system. It would be further desirable to accommodate such uninterrupted operation of a single control sequence by providing a coupling valve that approximates the pneumatic characteristics of a removable portion of controlled pressure system. It would be desirable to provide such a connector that is inexpensive to manufacture and configured for use in a prophylaxis sequential compression apparatus. Accordingly, a fluid conduit connector apparatus is provided that facilitates uninterrupted execution of a single pressure timing sequence when a fluid conduit is removed from a pneumatic system. The fluid conduit connector apparatus overcomes the disadvantages and drawbacks of the prior art when incorporated in a prophylaxis sequential compression apparatus by reducing control system complexity, providing ease of use and minimizing interruption to patients. Desirably, the fluid conduit connector apparatus includes a port portion including a valve to achieve the advantages of the present disclosure. Most desirably, the fluid conduit connector apparatus has a valve that approximates the pneumatic characteristics of a removed pneumatic system component. The fluid conduit connector apparatus is easily and efficiently fabricated. The fluid conduit connector apparatus, in accordance with the principles of the present disclosure, is adapted for use with a compression apparatus. The fluid connector apparatus includes a connector having a plurality of fluid ports formed therewith that facilitates fluid communication between a plurality of fluid conduits of the compression apparatus and a pressurized fluid source. Each of the plurality of fluid ports defines a fluid orifice configured for fluid flow. A valve is disposed with one of the fluid ports. The valve is operable to engage the fluid port such that disconnect of a fluid conduit of the compression apparatus corresponding to the fluid port from the connector reduces a dimension of the fluid orifice of the fluid port. The fluid connector apparatus can include a first connector having a first plurality of fluid ports formed therewith that fluidly communicates with a first plurality of fluid conduits. In an illustrative embodiment, the first plurality of fluid conduits is a set of three air tubes. A valve is supported with the first connector and is movable such that upon disconnection of one of the first plurality of fluid conduits from the first connector, the valve engages a corresponding fluid port in a configuration that creates a reduced fluid orifice therein. The valve is adapted to approximate pneumatic characteristics of a connected apparatus when the connected apparatus is disconnected from the first connector. In another embodiment, one of the fluid ports includes a coupling port and one of the first plurality fluid conduits includes a quick-disconnect fitting adapted for removable mating with the coupling port. The valve is disposed in the coupling port and can, for example, include a spring loaded plunger. An illustrative coupling fitting includes an engagement portion extending therefrom. The spring loaded plunger is displaced by the engagement portion when the coupling fitting is mated to the coupling port. In one embodiment, the coupling port includes a cap portion disposed therein. The spring loaded plunger engages the cap portion to create an orifice that provides a pneumatic behavior approximating one of the first plurality of fluid conduits when the coupling fitting is disconnected from the coupling port. In an illustrative embodiment, the fluid connector apparatus according the present disclosure also includes a second connector in fluid communication with a second plurality of fluid conduits. In an exemplary embodiment, the second plurality of fluid conduits is a set of three air tubes. A plurality of couplings is in fluid communication with the air tubes. The first connector includes a sleeve defining a cavity adapted for mating with the plurality of couplings. The cavity defines a female mating receptacle. The plurality of couplings defines a male mating plug adapted for mating with the female mating receptacle. In certain embodiments, the first and/or second connectors include improved streamlining of their outer surfaces to prevent snagging of the connectors on patient garments and bedding. In one embodiment, the first connector includes an interference key in the cavity to prevent the first connector from mating with legacy connector components. The second connector includes a clearance space for the interference key. In yet another embodiment, the first plurality of fluid conduits is a set of webbed tubing having increased webbing volume between at least one pair of adjacent conduits. At least one interference rib is formed between at least one pair of adjacent fluid ports in the first plurality of fluid ports. The increased webbing volume is aligned with the interference rib if the plurality of fluid conduits is improperly oriented with said first connector. The interference rib thereby prevents attachment of improperly oriented fluid conduits to the first connector. Similarly, the second plurality of fluid conduits can include an increased webbing volume configured to interfere with an interference rib between adjacent ports in the second connector to prevent attachment of improperly oriented fluid conduits to the second connector. In one embodiment of the present disclosure, the fluid conduit connector apparatus further includes a gasket disposed in the cavity. The gasket is adapted to provide fluid sealing between the first and second connectors when the first and second connectors are mated together. In at least one embodiment, the sleeve includes a window extending at least partially therethrough. The second connector includes a locking arm extending therefrom. The locking arm is adapted to engage the window to releasably retain the first connector with the second connector. The sleeve can include a slot extending to the window which partially bifurcates the sleeve to define opposing snap arms for engaging the locking arm. One of the first or second connectors can include an alignment slot and the other of the first or second connectors can include an alignment rib configured for engaging the alignment slot. In a particular illustrative embodiment, the locking arm includes a leading surface inclined at a first angle to provide a predetermined engagement force between the locking arm and snap arms, and a trailing surface inclined at a second angle to provide a predetermined disengagement force between the locking arm and snap arms. The predetermined engagement force can be designed, for example, to be less than the predetermined disengagement force. In another embodiment of the present disclosure, a fluid connector apparatus includes a first connector having tubular walls defining a plurality of fluid ports adapted to connect to a first plurality of fluid conduits. At least one of the fluid ports comprises a coupling port. At least one of the first plurality of fluid conduits includes a coupling fitting adapted for removable mating with the coupling port. A valve is disposed within the coupling port. The valve engages the coupling port to create an orifice approximating pneumatic behavior of one of the first plurality of conduits when the coupling fitting is disconnected from said coupling port. A second connector is adapted to connect to a second plurality of fluid conduits and mate with the first connector. In an exemplary embodiment, the valve includes a spring loaded plunger disposed in the coupling port. In one embodiment, the coupling fitting includes an engagement portion extending therefrom. The spring loaded plunger is displaced by the engagement portion when the coupling fitting is mated to said coupling port. The coupling port includes a cap portion disposed therein. The spring loaded plunger engages the cap portion to create an orifice that provides a pneumatic behavior approximating said one of the first plurality of fluid conduits when the coupling fitting is disconnected from the coupling port. In another embodiment of the fluid connector apparatus, the second connector comprises a plurality of couplings in fluid communication with the second plurality of fluid conduits. The first connector includes a sleeve formed therewith defining a cavity adapted for mating with the plurality of couplings. The sleeve includes a window extending at least partially therethrough. The second connector includes a locking arm extending therefrom which is adapted to engage the window to releasably retain the first connector with the second connector. The sleeve includes a slot extending to the window and partially bifurcating the sleeve to define opposing snap arms for engaging the locking arm. A particular embodiment of the present disclosure a fluid connector apparatus includes a sleeve connector having tubular walls defining a plurality of fluid ports adapted to connect to a first tubing set including an ankle tube, a calf tube and a thigh tube. One of the ports includes a coupling port. The thigh tube has a coupling fitting adapted for removable mating with the coupling port. In the particular embodiment, a valve is disposed within the coupling port. The valve includes a spring loaded plunger which engages the coupling port to create an orifice approximating pneumatic behavior of the thigh tube when the fitting is disconnected from the coupling port. The coupling fitting includes an engagement portion extending therefrom. The spring loaded plunger is displaced by the engagement portion when the coupling fitting is mated to the coupling port. The coupling port includes a cap portion disposed therein. The spring loaded plunger engages the cap portion to create an orifice that provides pneumatic behavior approximating the thigh tube when the coupling fitting is disconnected from the coupling port. A tubing set connector can be adapted to connect to a second tubing set and mate with the sleeve connector. The tubing set connector includes a plurality of couplings in fluid communication with the second tubing set. The sleeve connector includes a sleeve formed therewith defining a cavity adapted for mating with the plurality of couplings, and having a gasket disposed in the cavity. The gasket is adapted to provide fluid sealing between the sleeve connector and the tubing set connector. In at least one embodiment, the gasket includes a retention portion extending therefrom. The sleeve includes a gasket retention groove adapted to accept the retention portion and thereby retain the gasket to the sleeve. In a particular embodiment, the sleeve includes a window extending at least partially therethrough. The tubing set connector includes a locking arm extending therefrom. The locking arm is adapted to engage the window to releasably retain the sleeve connector with the tubing set connector. The sleeve includes a slot extending to the window and partially bifurcating the sleeve to define opposing snap arms for engaging the locking arm. One of the sleeve connector or the tubing set connector includes an alignment slot and the other of the sleeve connector or the tubing set connector includes an alignment rib configured for engaging the alignment slot. In another embodiment, the present application discloses a coupling apparatus including a coupling fitting permanently mounted to a first end of a fluid conduit. A second end of the fluid conduit is connected to an inflatable device. A coupling port is adapted for mating with the coupling fitting and includes a valve supported with the coupling port. The valve approximates pneumatic characteristics of the inflatable device and fluid conduit when the coupling fitting is disconnected from the coupling port. In another particular embodiment, the coupling fitting can include a proximal cylinder and a distal cylinder extending therefrom. A central longitudinal axis extends through the proximal cylinder and distal cylinder. The proximal cylinder has an inside diameter approximately equal to the outside diameter of said fluid conduit to facilitate an interference fit therebetween. The distal cylinder has an inside diameter approximately equal to the outside diameter of said coupling port to facilitate a slip fit therebetween and includes a locking tab extending radially from the outer surface of the distal cylinder. The coupling port includes a fluid communication channel and is incorporated with a sleeve having a detent for engaging the locking tab to removably secure the coupling fitting to the coupling port. Alternatively, the sleeve or interior surface of the first connector can include a detent cavity extending at least partially into the interior surface and adapted for accepting the locking tab. An exemplary detent cavity includes a longitudinal track portion adapted for guiding the locking tab during engagement and disengagement and an annular portion adapted for retaining the locking tab when the coupling fitting is rotated about its longitudinal axis. Along its length, the detent cavity can have varying depth or width into the interior surface. The varying depth of the detent cavity provides a predetermined engagement/disengagement force/displacement profile between the locking tab and the detent cavity. In one embodiment, the locking tab has an outer portion with an enlarged manual engagement surface to assist manipulation of the locking tab. In an illustrative embodiment, the valve includes a spring loaded plunger. The spring is compressed by engagement between the coupling fitting and the plunger to open the coupling port for fluid communication when the coupling fitting is connected to the coupling port. The spring is extended to force the plunger into the channel. The plunger is perforated to provide a predetermined fluid resistance through the channel when the coupling fitting is disconnected from the coupling port. In another embodiment, the present disclosure provides a fluid connector apparatus including a first connector having a first plurality of fluid ports formed therewith which fluidly communicate with a first plurality of fluid conduits. A second connector is in fluid communication with a second plurality of fluid conduits and includes a plurality of couplings in fluid communication therewith. Restrictor means within the first connector are provided for approximating pneumatic characteristics of one of the fluid conduits when it is disconnected from the first connector. In yet another embodiment, the present disclosure provides a method of coupling a pressure source to a pneumatic device. According to the method of the present disclosure, a first plurality of fluid conduits from the pneumatic device is connected to a second plurality of conduits from the pressure source using a multi-port tube connector. One of the first plurality of conduits is disconnected from the multi-port tube connector. A valve is thereby released in the connector which approximates the pneumatic characteristics of one of the first plurality of conduits. Another illustrative embodiment of the present disclosure provides a fluid conduit coupling. The fluid conduit coupling has a coupling fitting with a proximal cylinder and a distal cylinder monolithically formed with the proximal cylinder along a central longitudinal axis. The proximal cylinder has an inside diameter adapted for receiving a fluid conduit. The fluid conduit coupling also includes a fluid port having a male cylindrical portion extending proximally therefrom and a fluid channel extending through the port from the male cylindrical portion to a distal opening. The distal cylinder of the coupling fitting includes a female orifice adapted for mating with the male cylindrical portion of the coupling port. A valve disposed in the port is operatively configured to approximate pneumatic characteristics of a disconnected device when the coupling fitting is detached from the coupling port. The coupling fitting of the fluid conduit coupling according to the illustrative embodiment has an engagement portion adapted to displace the valve in the coupling port. The valve includes plunger biased proximally by a spring force. The engagement portion is aligned to displace the plunger distally against said spring force when the fitting is attached to the port. The plunger providing an increased fluid passage when displaced distally and a reduced fluid passage when biased proximally. | 20040223 | 20090217 | 20050825 | 91491.0 | 0 | ROST, ANDREW J | FLUID CONDUIT CONNECTOR APPARATUS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,784,663 | ACCEPTED | Post-session internet advertising system | The present invention is directed to a post-session advertising system that may be used in media such as computers, personal digital assistants, telephones, televisions, radios, and similar devices. In one preferred embodiment, a first display is viewed in a first platform in the foreground of a media by a viewer. A viewer initiates a load triggering event and in response, a post-session platform is opened to display a post-session display in the background of the media. Significantly, in the preferred embodiment, the post-session platform stays in said background until a view triggering event occurs. The type of platform and display used will depend significantly on the media. In one preferred embodiment of the present invention an optional focus timer is activated by the view triggering event to allow an accurate assessment of the actual time a viewer focuses on the display in the post-session platform. In another alternate preferred embodiment of the present invention, the number of post-session platforms is limited to, for example, one platform. | 1-19. (canceled). 20. A system for Internet advertising for use in a media capable of simultaneously maintaining a foreground window and at least one background window and capable of displaying a first browser in a said foreground window for selectively browsing the Internet, said system comprising: (a) a script handler that invokes a post-session procedure in said first browser, said post-session procedure opening a second browser in a said background window while said first browser is simultaneously displayed in said foreground window; and (b) an event handler that receives an advertisement and loads said advertisement into said second browser while said second browser is in a said background window. 21. The system of claim 20 where said second browser is opened in response to a load-triggering event. 22. The system of claim 21 where said load-triggering event comprises at least one of: (a) clicking on an off-site link; (b) entering a new address; (c) refreshing a web site (d) exiting a web site; and (e) being redirected to a web site. 23. The system of claim 21 where said script handler delays invocation of said post-session procedure for a predetermined time period. 24. The system of claim 23 where said script handler cancels invocation of said post-session procedure if a user loads a new web site in said first browser before said predetermined time period has elapsed. 25. The system of claim 20 where said second browser is displayed in a foreground window after the occurrence of a view-triggering event. 26. The system of claim 25 including a focus timer that tracks the duration that said second browser is displayed in said foreground window. 27. The system of claim 20 where said media comprises one of a computer, a PDA, a cell phone, and a television. 28. The system of claim 20 where said event handler selects and returns one of a plurality of advertisements maintained at an Internet address. 29. The system of claim 28 capable of opening a plurality of second browsers, each maintained in a separate said background window, said event handler capable of receiving a link to an advertisement for each said second browser and loading a respective said advertisement into each said second browser while each said second browser remains in its respective said background window. 30. A post-session advertising method for use in a media capable of simultaneously maintaining a background window and a foreground window, said method comprising the steps of: (a) embedding post-session instructions into a first browser, said first browser for being displayed in said foreground window; (b) said post-session instructions opening a second browser in a said background window while said first browser is being displayed in said foreground window; (c) said post-session instructions receiving an advertisement; and (d) loading said advertisement into said second browser while said second browser is in said background window. 31. The method of claim 30 where said second browser is opened in response to a load-triggering event. 32. The method of claim 31 where said load-triggering event comprises at least one of: (a) clicking on an off-site link; (b) entering a new address; (c) refreshing a web site (d) exiting a web site; and (e) being redirected to a web site. 33. The method of claim 31 where implementation of said post-session instructions is delayed for a predetermined time period. 34. The method of claim 33 where implementation of said post-session instructions is canceled if a user loads a new web site in said first browser before said predetermined time period has elapsed. 35. The method of claim 30 where said second browser is displayed in a foreground window after the occurrence of a view-triggering event. 36. The method of claim 35 including the step of tracking the duration that said second browser is displayed in said foreground window. 37. The method of claim 30 where said media comprises one of a computer, a PDA, a cell phone, and a television. 38. The method of claim 30 where an event handler selects and returns one of a plurality of advertisements maintained at an Internet address. 39. The method of claim 38 where a plurality of second browsers are opened, each maintained in a separate said background window, and a link is received to an advertisement for each said second browser and a respective said advertisement being loaded into each said second browser while each said second browser remains in its respective said background window. | RELATED APPLICATIONS This application is a divisional of U.S. patent application Ser. No. 09/866,425, filed May 24, 2001, which is based on and claims the benefit of provisional application Ser. No. 60/207,698, filed May 26, 2000. BACKGROUND OF THE INVENTION The post-session Internet advertising system of the present invention is a system and method for delivering displays to viewers browsing displays with platforms, for exchanging traffic between platforms, and for accurately tracking focus time on display content. Web pages can be created using Hypertext Mark-up Language (“HTML”) and Extensible Mark-up Language (“XML”). HTML is a text-based set of instructions (known as “tags”) that describe the layout of elements on a Web page. HTML can also be used to create “links” (generally, a highlighted word, phrase or graphic image that points to a target such as another Web page) on the World Wide Web. XML consists of a set of tags that abstractly describe data, which can be translated into HTML using standard tools. In addition, a Web page can be divided into subpages (using Frames, an HTML extension). A frameset is the set of subpages that together comprise a Web page. (For example, a Web page may be divided horizontally creating a frameset of two subpages comprising the top and bottom half of the Web page). In addition to its use in creating Web pages, HTML and XML can be used to create advertising for the Internet. The developer or maintainer of a Web site can insert HTML or XML code in their Web pages so that when potential customers view the Web page an advertisement and a link to another Web site is displayed. Web pages and Internet advertising may be enhanced by small programs written in the Java language that are built into a Web page to perform a specific function (such as displaying an animation), often referred to as “applets.” In addition, scripting languages such as JavaScript or VBScript are used to enhance the capabilities of Web pages by performing functions that are beyond the scope of HTML and XML, such as popping up special windows in response to mouse clicks. Scripting languages include an event driven model responsive to changes in a client's state and an Application Programmer's Interface for defining custom behaviors to be followed in response to such “events.” Another technique often used by Web site developers and Internet advertisers is to place a text file on the hard disc of a client when the user visits a Web site. These text files, referred to as “cookies,” are retrieved and read on subsequent visits that a user makes to the Web site. Cookies can be used to track the behavior of site visitors. The economic potential of the Internet is enormous, but the medium is still in its early stages of development. Revenue is directly proportional to the volume of qualified potential customers (“traffic”) that reach and view a commercial Web site. Each visit (often referred to as a “hit”) to a commercial Web site has economic value. Thus, the primary goal of Internet marketing is generating traffic. A secondary goal is to get potential customers to make purchases or otherwise use a commercial Web site (i.e., “capture traffic”). Traffic is more difficult to generate than it is to capture. Further, investment made to generate traffic produces a greater economic return than investment made to capture traffic. A company can a spend a lot of money on effective Web site design so that potential customers will have a rewarding experience and thus a higher inclination to make a purchase once the customer has reached the Web site. But investment in Web site design is wasted unless the site is actually visited. A third goal is “branding,” or increasing consumer awareness or recognition of a brand. In order to meet these goals, most Internet businesses use interrupting advertisements such as pop-up windows, or space consuming advertisements (or “real estate” consuming advertisements) such as banner advertisements, link exchanges, and banner exchanges. Other Internet businesses use alternative advertising methods such as bulk e-mail. Although interrupting advertisements guarantee that a user will see the advertisement for at least a split second, if only to locate the icon used to close the window, these interrupting advertisements are particularly offensive to potential customers because they force the user's attention to be diverted. Most users simply close the window of an interrupting advertisement. Space consuming advertisements, on the other hand, are so pervasive that they have become “white noise.” Usually, a viewer focuses his attention on the information he needs from the Web page and ignores the space consuming advertisement. Alternative advertising methods are similarly problematic. With pop-up window advertising, a separate window of a Web browser is displayed “on top” or “in front” of the Web page being viewed. The advertisement, which may be larger, smaller, or the same size as a banner advertisement, is displayed in the new browser window. Pop-up window advertising has the advantage (for the Web site designer) of displaying an advertisement without having to change the layout of the Web page displaying the advertisement. But potential customers commonly consider the pop-up aspect disruptive and annoying. Banner advertising, a space consuming advertising method, is currently the primary method of advertising on the World Wide Web. Banner advertising relies on HTML and some of the techniques used to create a Web site. Site maintainers insert HTML code in their Web pages that causes a small advertisement (approximately 0.5″ times 2″ on the average screen) to appear in a frame on the Web page, i.e., a “banner advertisement.” The HTML code also contains a link to another site. In short, when potential customers view a Web site with banner creating HTML code, a banner advertisement and link are displayed on the Web page. The more traffic a Web sites has, the more it can charge for displaying banner advertisements. The reason is that a banner advertisement placed on a high volume site generates a lot of traffic for the advertised Web site. In theory, this is advantageous for both parties. But market research shows that as use of the Internet becomes widespread, banner advertisements are becoming less effective. The average potential customer is becoming jaded because banner advertisements appear on almost every Web site. A measure of the effectiveness of Internet marketing is the CTR, or click-through ratio. CTR is the ratio of the number of times an advertisement is exposed to the number of hits generated by the advertisement when viewers “click through” to the advertised site. The trend is that CTRs for banner advertisements are dropping. Link exchanges are another space consuming advertising method for generating Web traffic. A link exchange is an arrangement whereby a first Web site puts a link on its site to a second Web site. In exchange, the second Web site places a link on its site to the first Web site. In addition to exchanging links, a fee may be paid by one site to the other. Each link to the other site is generally placed in a prominent place on the referring Web site. Effectively, a link exchange is a mechanism for sharing traffic between two Web sites. Alternatively, links may not be exchanged. Instead, a first Web site pays a second Web site to put a link to it on the second Web site. Link exchange advertising has the advantage of lower cost than other advertising methods. In fact, a link exchange may be free. In addition, any consideration paid for a link exchange or link placement is generally much lower than that for banner advertisements. A drawback of link exchanges is that their effectiveness varies. The effectiveness depends on where the link is placed, whether there is an image associated with it (thus blurring the line between a link exchange and a banner advertisement), and how much traffic each site receives from other forms of marketing. Market research shows that CTRs on link exchanges are consistently lower than CTRs for banner advertising. Banner exchanges are a hybrid of banner advertising and link exchanges. A Web site joins a Web site syndicate and adds special banner advertisement HTML code to its Web site. The special HTML code causes a banner advertisement for and a link to a syndicate member Web site to be displayed. Typically, the banner advertisement varies so that an advertisement for each syndicate member is alternately displayed. A syndicate may be joined for free or for a nominal fee. In exchange for displaying banner advertisements, banner advertisements for the member's Web site are displayed on the Web sites of other members. In addition, the company managing the exchange syndicate will usually have paid advertisers as members. Fees paid by such advertisers represent a source of revenue for the company managing the exchange syndicate. A limitation of banner exchanges is that they are still fundamentally banner advertisements and as such are experiencing the same declining CTRs as conventional banner advertisements. Bulk e-mail is an alternative advertising method that has a reasonable return on investment but potential customers generally regard it unfavorably. If the bulk e-mail message is read, it may effectively generate traffic. But it is far more likely that the potential customer immediately identifies the message as a “UBE” (unsolicited bulk e-mail), sends complaints to the sender and to their connection provider, and deletes the message unopened and unread. Two events that are important to understanding the experience of a viewer browsing the Web are the “focus” and “blur” events. Typically, a viewer accesses the Internet using a platform, such as a Web browser, on media, such as a computer. For example, a viewer accessing the Internet using the Internet Explorer™ Web browser as a platform on media consisting of a computer running the Windows™ operating system observes the platform as appearing in a window. Focus and blur describe states of a window. A focus event occurs if a window is selected so that it may currently receive input from a viewer. A blur event occurs if focus is removed from a window. While it is possible to simultaneously have multiple windows open, only one window may have focus at any time. If a window is in the focus state, it always fully visible (i.e., it appears “on top” of other open windows) and is sometimes referred to as the “active” window. Windows that are in the blur state are said to be in the “background” and are at least partially obscured by the window in the focus state. A viewer “clicks on” or otherwise selects a window to create a focus event. Alternatively, a computer program may cause a focus event. A focus event may also be referred to as a “view triggering event.” With known Web marketing techniques there is no way of knowing if an advertisement has been seen by the potential customer. A banner advertisement, pop up window, or other Internet advertisement may appear at length in an active window and be fully visible, or may appear only momentarily in an active window and be at least partially obscured for most of the period it is displayed. The time an advertisement is displayed in an active window is called “focus time.” Known techniques do not verify the focus time of an advertisement that has been delivered to a potential customer. BRIEF SUMMARY OF THE INVENTION The post-session Internet advertising system of the present invention is a system and method for delivering displays to viewers browsing displays with platforms, for exchanging traffic between platforms, and for accurately tracking focus time on display content. This method of content delivery overcomes many of the inherent limitations of known Internet based advertising methods. The present invention is directed to a post-session advertising system that may be used in media such as computers, personal digital assistants, telephones, televisions, radios, and similar devices. In one preferred embodiment, a first display is viewed in a first platform in the foreground of a media by a viewer. Then, a load triggering event is initiated by the viewer. Next, in response to the load triggering event, a post-session platform is opened to display a post-session display in the background of the media. Significantly, in the preferred embodiment, the post-session platform stays in the background until a view triggering event occurs. The type of platform and display used will depend significantly on the media. In one preferred embodiment of the present invention an optional focus timer is activated by the view triggering event to allow an accurate assessment of the actual time a viewer focuses on the display in the post-session platform. In another alternate preferred embodiment of the present invention, the number of post-session platforms is limited to, for example, one platform. Multiple load triggering events would either be ignored or would cause the display to refresh (or change) in the already loaded post-session platform. The computer and the Internet are exemplary media that might be used in the present invention. In this exemplary embodiment, Web browsers are the platforms. Further, in this exemplary embodiment, Web sites and advertisements are exemplary display content. More specifically, while a participating Web site (display content) is being visited by a viewer using a first Web browser (platform), a second or post-session Web browser (platform) loads with a second or post-session advertisement (display content) upon a first or load triggering event such as exiting the specific Web page. The post-session Web browser does not disrupt the viewer's browsing experience in his first Web browser. Instead, a second or view triggering event, such as closing the first Web browser, allows the post-session Web browser (and the advertisement thereon) to be viewable by the viewer. The present invention may also monitor the period of time that the advertisement appears in the now active post-session Web browser and provides statistical information to advertisers. The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING FIG. 1 is a block diagram of an exemplary embodiment of a client, a Web server, media, and at least one viewer, platforms and displays of the post-session Internet advertising system of the present invention. FIG. 2 is a flow diagram showing the sequence of steps that a viewer observes or initiates in the process of delivering a display in an exemplary embodiment of the post-session Internet advertising system of the present invention. FIGS. 3A, 3B, and 3C are block diagrams of an exemplary embodiment of a Web server, a client, media, and a count daemon of the present invention showing a load triggering event, a view triggering event, and data flow of the post-session Internet advertising system of the present invention. FIG. 4 is a flow diagram of the script handler of an exemplary preferred embodiment the post-session Internet advertising system of the present invention. FIG. 5 is a flow diagram of the event handler of an exemplary preferred embodiment the post-session Internet advertising system of the present invention. FIG. 6 is a block diagram showing data flow of an exemplary preferred embodiment of a focus handler, media, and the count daemon of the post-session Internet advertising system of the present invention. FIG. 7 is a block diagram showing the data path to and the thread components and data path within the count daemon of an exemplary preferred embodiment the post-session Internet advertising system of the present invention. FIG. 8 is flow diagram of the process of the post-session Internet advertising system of the present invention. FIG. 9 shows an exemplary screen view of a frameset displaying branding information in an upper frame and client advertising content in a lower frame in one preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION The post-session Internet advertising system of the present invention is a system and method for delivering displays to viewers browsing displays with platforms, for exchanging traffic between platforms, and for accurately tracking focus time on display content. As shown in FIGS. 1 and 2, a client 20 interacts with a Web server 22 to deliver, upon the occurrence of a “load triggering event,” a post-session platform 24 to a viewer's 26 media 28 so that the viewer 26 may view the client's 20 post-session display 30 after the viewer 26 has exited (or another “view triggering event” has occurred) a foreground platform 32. Specifically, when the viewer 26 who is viewing a first or foreground display 34 in a first or foreground platform 74 exits a client's foreground platform 32 (or another load triggering event occurs 76), a post-session platform 24 is opened and is immediately sent to the background 78. Because it is in the background, the post-session platform 24 does not disrupt the viewer's 26 browsing experience. When the viewer 26 closes the foreground platform 32 (either the original or a subsequent platform 32) or another view triggering event occurs 80, the post-session platform 24 comes to the foreground 82. Finally, in one preferred embodiment, the amount of time the post-session platform 24 spends in the foreground may be monitored. Throughout this specification terminology will be used to describe the present invention. The following definitions and examples of the terminology are not meant to exclude broader concepts, unspecified examples, or undeveloped technology that would logically fall within the scope of the invention. Viewers 26, for example, may be potential voters viewing a television program or potential customers browsing the Internet on a computer. The term “viewer” is also used to describe a telephone user, a radio listener, or any media user. Clients 20 are entities that want to advertise or direct traffic such as commercial enterprises, political, governmental, non-profit, or charitable organizations, individuals, hobbyists, or any other person or entity that wants to advertise or direct traffic. The Web server 22, as will be described in detail below, substantially controls or directs the system of the present invention. Media 28 may be any communication device, including but not limited to computers, personal digital assistants, telephones, televisions, radios, and similar devices. Platforms 24, 32 are means through which a viewer accesses a display to the exclusion of other displays. A platform may allow the viewer to play, show, enable, perform, transmit, update, or record the selected display. Platforms 24, 32 may include, for example, Web browsers, browser windows, media channels, media stations, media frequencies, audio connections, streaming media, content delivery applications, media viewing or interacting technology, and similar means. A foreground platform 32 is a platform that can be primarily sensed by a viewer 26. A post-session platform 24 is a platform that begins its life in the background and that can be fully sensed by a viewer 26 only after it has been brought to the foreground. Displays 30, 34 have content that a viewer 26 sees, hears, or otherwise senses within or from a platform 24, 32. Displays 30, 34 may include, for example, Internet content (such as streaming video, Web sites, Web pages), video broadcast content (such as television programs, movies, videos, commercials, and infomercials), audio broadcast content (such as radio programs, commercials, and sound recordings or such as commercials or sound recordings played over a telephone connection), and any other content capable of being transmitted over media. As mentioned above, FIG. 2 is a flow diagram showing the sequence of events from the viewer's 26 perspective. The viewer 26 first views 74 a first or foreground display 34 in a first or foreground platform 32 of media 28. The viewer 26 then initiates 76 a load triggering event. This event causes the opening 78 of a second or post-session platform 24 in the background of the media 28. The post-session platform 24 remains in the background until the viewer 26 initiates 80 a view triggering event. The viewer 26 then views 82 the post-session display 30 in the post-session platform 24. FIGS. 3A-3C show an exemplary system of the present invention with data flow between elements of the system. It should be noted that the functions shown in the Web server 22 element may be implemented by the Web server 22 alone (as shown), by a combination of the Web server 22 and the client 20, or by the client 20 alone. It should also be noted that the media 28 is shown as providing the foreground platform 32, the post-session platform 24 while it is in the background, and the post-session platform 24 while it is in the foreground. Exemplary individual elements of the system are detailed in separate figures. Specifically, FIG. 4 details an exemplary script handler 42, FIG. 5 details an exemplary event handler 44, FIG. 6 details an exemplary focus handler 46 and the timer applications, and FIG. 7 details an exemplary count daemon 48. FIG. 8 is a flow diagram showing the sequence of steps in the process of delivering display content in the embodiment of the present invention shown in FIGS. 3A-3C. In the first step, a client 20 adds post-session instructions to its display 50. A viewer 26 requests a foreground display 52 from a first or foreground platform with post-session instructions embedded (or otherwise linked) therein. After the foreground display 34 loads, the post-session instructions cause a post-session procedure 43a to be requested 54 and, in turn, the script handler 42 returns a post-session procedure 43b, 56. At some point the viewer 26 initiates a load triggering event 58. This load triggering event causes a post-session platform to open 60 in the background (physically behind or otherwise hidden from the viewer) and also causes the post-session platform to request a post-session display 62. In one alternative embodiment, the post-session platform 24 that opens is of a type different from the foreground platform 32. The event handler 44 receives the request for a link 45a, 62 and returns a link to post-session display 45b, 64. In an alternative preferred embodiment, the client 20 includes an event handler 44 that receives request 62 and returns a post-session display 64 into a secondary post-session platform. Optionally, the event handler 22 returns a focus timer process 45c, 66. The post-session platform 24 and display 30 remain in the background until the viewer 26 initiates a view triggering event 68. The viewer 26 views the post-session display in the post-session platform 69. After the viewer 26 is done viewing the post-session display 30, the viewer 26 exits the post-session display 70. Optionally, when the viewer 26 exits the post-session display, time data 47 may be returned to the focus handler 72. A count daemon 48 (which may be housed in the Web server or in a secondary server 84) optionally may monitor and/or analyze statistical data. It should be noted that the script handler 42, event handler 44, and focus handler 46 may be processes implemented by the Web server 22 as shown or may be processes implemented by a plurality of servers or may be multiplied or divided into any number of processes. Applying the basic flow shown in FIGS. 3A-3C and 8 to an exemplary embodiment of a Web surfer viewer surfing the Internet, a commercial client 20 adds post-session instructions (HTML code) to its Web page display 50. A surfer 26 requests the client's Web page 52 with the post-session instructions (HTML code) embedded therein. After the foreground Web page 34 loads, the post-session instructions (HTML code) cause a script code 54 to be requested and, in turn, the Web server 22 returns a script code 56. At some point the surfer 26 initiates a load triggering event 58, usually by exiting the initially viewed client's Web page. This load triggering event causes a post-session browser to open 60 behind the foreground browser and also causes the post-session browser to request a post-session display 62. The Web server 22 receives request 62 and returns a link or address to a post-session display 64. Optionally, the Web server 22 also returns a focus timer 66. The post-session browser 24 and display 30 remain in the background until the surfer 26 initiates a view triggering event 68 such as exiting the foreground browser 32. The surfer 26 views the post-session display in the post-session browser 69. After the surfer 26 is done viewing the post-session display 30, the surfer 26 exits the post-session display 70 and time data is optionally returned to the Web server 72. Detailed Chronological Description The following paragraphs provide exemplary details of one exemplary method by which the present invention may be implemented. Alternate methods could be developed by those skilled in the art to implement the basic concepts of the present invention. These details will be addressed in substantially the same order in which they were discussed in relation to FIGS. 3A-3C and 8. First, it should be noted that the present invention may be implemented on the World Wide Web service on the Internet or other analogous network service in an alternate network environment (e.g. a telephone network or a television network). The term Web server 22 is meant to be broadly construed to be applicable to alternate network environments. Details of opening and maintaining a network connection, selecting the appropriate actions for various uniform resource indicators, content negotiation, and transaction logging handled by the existing Web server system, however, are meant to be exemplary as such protocols may or may not be necessary in alternate network environments. As shown in FIGS. 3A-3C, the functions of the Web server 22 may be divided into the three Web services: the script handler 42 (FIG. 4), the event handler 44 (FIG. 5), and the focus handler 46. These services may be implemented as separate processes by a Web server (as shown), as a single process, or as any number of processes on any number of servers. These services may also be implemented by the client's system or on the viewer's media. These services are similar in some functions, but there are differences in which portion of a single transaction each service handles. For example, each service can read its state from the information and cookies present in the HTTP connection headers. Each service can retrieve account information from a relational database about the requesting client 20. Each service may transmit statistical packets to a caching statistical collation module, referred to as the “count daemon” 48 (detailed in FIG. 7), and then may deliver an appropriate response to the post-session Web browser. The response can also optionally include state and status information about the post-session Web browser in the form of cookies. These services will be discussed individually in the order they appear in the system as shown and described in FIGS. 3A-3C and 8. Adding Post Session Code. In order to activate the method of the present invention, a client 20 obtains post-session instructions from a Web Server 22 and adds them to its display 34. In one exemplary preferred embodiment, the post-session instructions are post-session HTML code that a client 20 adds to its Web pages. In an alternative preferred embodiment, the post-session instructions are post-session XML code that a client 20 adds to its Web pages. Viewer Opens a Platform. A viewer 26 opens a client's 20 display 34 with a foreground platform 32. In one preferred embodiment, a viewer 26 opens a client's 20 Web page with a Web browser. Script Code Delivery. As shown in FIG. 3A, when a viewer 26 opens a client's 20 display 34 with a foreground platform 32, the post-session instructions that the client 20 added to its display 34 cause the foreground platform 32 to download 43a, 43b a post-session procedure from the Web server 22. In one exemplary preferred embodiment the post-session procedure downloaded from the Web server 22 to the platform 32 is script code. In one preferred embodiment, the client's account number is encoded directly into foreground platform's 32 request for a post-session procedure so that proper credit is given to the client 20 for bringing in traffic to the system of the present invention, for verification, and/or for determining the appropriate category of advertisement to return. Script Handler. In the exemplary preferred embodiment shown in FIGS. 3A and 4, when a viewer requests a display 34 to which post-session HTML code has been added, a request for a post-session procedure 43a is sent to the script handler 42. The time at which the request for the post-session procedure is made is preferably recorded, noted, and/or stored. In addition, the script handler 42 may verify that the account number present in the requesting link is valid. The script handler 42 then returns a post-session procedure 43b to the platform 32. As illustrated in the exemplary embodiment of FIG. 4, the script handler 42 may parse each request and assemble statistics packets for transmission to the count daemon 48. If a viewer subsequently requests a second client Web page, a second request for script code is sent to the script handler 42. Using the time data that has been recorded, noted, and/or stored, the length of time that has elapsed between the initial and subsequent requests is determined. The script handler 42 determines if the elapsed time is longer or shorter than a specified time period (“time window”). If the elapsed time is shorter than the time window, script code specifying that no operations are to be performed is returned (blank script). If the elapsed time is longer than the time window, normal script code is returned. Finally, a response is assembled and returned to the viewer's foreground platform 32. The reason for determining whether a second request for script code is made within a time window is to provide the viewer with a reasonable opportunity to view a display before replacing it with a new display. If a viewer requests a second Web page to which the same client's (or, in an alternate embodiment, any client's) post-session HTML code has been added, a load triggering event occurs. If this load triggering event occurs within the time window, a request for script code will result in blank script code being returned. In other words, the viewer is not sent a second display. On the other hand, if this load triggering event occurs after the time window, the viewer will be sent a second display to replace the first unseen display. It should be noted that, although an optional feature of the present invention, this process of replacing unseen displays can be very strategic. Viewers tend to dislike being flooded with displays such as advertising. Where a single display causes the viewer to examine its content, multiple displays tend to aggravate the viewer. Accordingly, although the scope of the invention clearly includes opening multiple platforms with multiple displays, the preferred embodiment is to allow only allow a single post-session platform. It should also be noted that the “time window” could be replaced by a “hit counter” in which the replacement is not done for a certain number of hits. Alternately, there could be a ranking system in which clients/displays with higher rankings (perhaps paying versus unpaying clients/displays) cannot be replaced by clients/displays with lower rankings. These alternatives are meant to be exemplary and not to limit the scope of the invention. Load Triggering Event. At some point while viewing the display 34, the viewer activates a load triggering event. Load triggering events may include, for example, the viewer leaving or exiting the specific display 34 or the viewer closing the foreground platform 32. Exemplary alternative load triggering events may include clicking on an off-site link or entering a new address in a dialogue box, time delay, load, unload, click, resize, submit, focus, blur, drag, key press (including a mouse button key), select, change (contents of a form field), refresh, open, close, redirect, enter, exit, move, minimize, maximize, end of program, beginning of program, beginning of session, end of session, “switching services,” or change of service. These load triggering events are meant to be exemplary. Additional Load Triggering Events. In one exemplary preferred embodiment, if a first load triggering event is followed by a second load triggering event, a second post-session platform 24 is opened and sent to the background. In an alternative preferred embodiment, a second post-session platform is not opened. In an additional preferred embodiment, if a first load triggering event is followed by a second load triggering event, a second post-session window is opened only if the time period between load triggering events is shorter than a predetermined time period. Post-Session Procedure. The post-session procedure consists of a set of actions to be taken in response to the load triggering event. The post-session procedure causes no immediate visible change to the foreground display 34, but when the load triggering event occurs, a new platform (post-session platform 24) opens and is immediately sent to the background. The post-session platform 24 may be a full sized window or any other sized window. Event Handler. As shown in FIGS. 3B and 5, the event handler 44 is invoked by a request for a display link 45a by the newly opened post-session Web browser. The event handler 44 chooses and delivers a link to a client's Web site 45b. In one preferred embodiment, the event handler delivers a link to an HTML frameset. There is no requirement, however, that the post-session browser link to HTML code. In alternative preferred embodiments, the post-session browser links to any form of network content including sound, animation, streaming video, or any other form of rich media. In one preferred embodiment, the event handler 44 delivers links to automatically load the focus timer 45c. As shown in FIG. 5, the event handler 44 parses a request and assembles statistics packets which it then transmits to the count daemon 48. A response is assembled and returned to the platform 24. The post-session procedure downloaded from the Web server 22 to the platform 32 may be written in any supported scripting language, such as JavaScript or VBscript. In an exemplary preferred embodiment, the post-session procedure is an advertising session consisting of opening a post-session platform 24, linking to the Web server 22, sending the post-session platform 24 to the background (or conversely, bringing the viewer's platform to the foreground), and optionally loading a process used for tracking focus time. In other words, one preferred embodiment of the present invention uses the load triggering event to trigger an advertising session. Post-Session Platform. As shown in FIGS. 3B and 3C, the post-session platform 24 requests from the Web server 22 the address of display 30. In one preferred embodiment, the address of display 30 is the client 20. In alternative embodiments, the address may be, for example, other clients or the Web server. When display 30 is returned, the post-session platform 24 displays display 30. In one preferred embodiment, display 30 is advertising content for a client 20. In an alternative preferred embodiment, display 30 is a Web site or Web page of a client 20. In one preferred embodiment, as shown in FIG. 9, the post-session platform 24 shows the display 30 in a frameset with branding information of the Web server 22 in one frame and client advertising content in another frame. In one preferred embodiment, the post-session platform 24 is a default browser window of the same type as the current foreground platform 32. One alternate embodiment could have a specific viewer-specified default platform. Another alternate embodiment could use a default platform predetermined by the client 20, Web server 22, or the specific type of display. View Triggering Event. At some point after viewing the display 34, the viewer activates a view triggering event. View triggering events may include, for example, the viewer closing the foreground platform 32, the viewer selecting the post-session platform 24 from the task bar at the bottom of a media screen or an alternative menu structure, or the viewer minimizing or moving the foreground platform 32. Exemplary view triggering events could include clicking on an off-site link or entering a new address in a dialogue box, load, unload, click, resize, submit, focus, blur, drag, key press (including a mouse button key), select, change (contents of a field), refresh, open, close, redirect, enter, exit, maximize, end of program, beginning of program, beginning of session, end of session, “switching services,” or change of service. Still other view triggering events may be time controlled. These view triggering events are meant to be exemplary. It should be recognized from the exemplary view triggering events set out in the preceding paragraph that one feature of a view triggering event is that it is preferably viewer driven. While a view triggering event is initiated by viewer action, a time delay may also be an aspect of a view triggering event. For example, a viewer may initiate a view triggering event by clicking an off-site link, but the set of actions to be taken in response to the view triggering event may not occur for a pre-determined time period. In other words, the view triggering event may be time delayed. Post-Session Timer. As shown in FIGS. 3B and 6, in one preferred embodiment, the post-session procedure optionally includes the loading of a process used for tracking focus time. When the display 30 on the post-session platform 24 changes or the platform 24 is closed, the focus timer process returns time data to the Web server 22 or secondary server 84. The duration of time that the post-session platform spends in the foreground, and thus being viewed, is tracked. In the embodiment shown in FIGS. 3B, 3C, and 6, a focus timer is optionally delivered to a post-session Web browser by the event handler 44 and time data 47 is optionally returned to a focus handler 46. In an alternative preferred embodiment, the focus timer is incorporated into a post-session platform (the focus timer being implemented as a Java applet embedded in the frameset). The focus timer is linked to the post-session Web browser and monitors the activation of focus and blur events, signifying that the post-session Web browser has been brought to the foreground, sent to the background, or closed. In one preferred embodiment, the focus timer is incorporated into the post-session Web browser. It should be noted that while the focus timer process may only track the time period between when a post-session platform is brought to the foreground to when the post-session platform is closed, it may track time periods pertaining to other events relevant to a client. In one preferred embodiment, the focus timer process may track the length of the time the post-session platform is in the foreground although a viewer may bring a post-session platform to the foreground and return it to the background multiple times before the viewer ultimately closes the platform. In another alternative embodiment, the focus timer process tracks the length of time the post-session browser spends in the background. Focus Handler. As shown in FIGS. 3C and 6, the focus handler 46 receives time data 47 from the focus timer and transmits statistical packets to the count daemon 48 to track the focus time for a display 30 displayed in a post-session platform 24. In an exemplary shown embodiment, the focus handler 46 performs only minimal data lookup and returns a response to the focus timer that indicates that no content body follows. Count Daemon. As shown in FIGS. 3C and 7, the count daemon 48 receives statistics packets from the script handler 42, the event handler 44, and the focus handler 46 and collates statistical data. This reduces the load on the relational database. In an exemplary preferred embodiment, the count daemon 48 is implemented with three simultaneously operating processes, or “threads”: the listener, parse and cache threads. As shown in FIG. 7, the listener thread accepts packets from the network and inserts them into a queue. In one preferred embodiment, a plurality of listener threads each listen at a separate network address so that statistics for a plurality of services can be simultaneously collated by a single count daemon 48. The parse thread reads and analyzes the packets in the queue. In one preferred embodiment, the parse thread uses standard reference libraries for the parsing of XML. This advantageously reduces the complexity of processing. The cache thread reads and performs maintenance on the parsed packets as described below. As will be recognized by one skilled in the art, a parsed statistical packet represents all of the different pieces of information included in a single page load on a Web server. A single hit can have the effect of causing in excess of 40 individual values in the relational database to incremented. With daily hit quantities in the millions, directly updating a relational database would quickly overwhelm the capacity of the database storage media. In one preferred embodiment, the cache thread is implemented as follows: First, the cache data structures are abstracted to appear programmatically as simple data structures; second, each cache is configured with a maximum number of elements; third, when a cache member is requested that is not within the cache's current dataset, a request is made transparently to the database for the data corresponding to the specified key; fourth, if this action would cause the cache to have too many elements, the least recently used element is flushed (i.e., any changes are committed to the database) and deleted; and fifth, changed data items throughout the entire cache are periodically flushed. This embodiment is particularly advantageous where efficient use of the database storage media is desired. The rationale for using this kind of caching scheme is based on the proportional distribution of hits per day. For example, a “busy” client Web site may receive 432,000 hits/day or 5 hits/second; an “average” client Web site may receive 86,400 hits/day, or 1 hit/second; and a “slow” client Web site may receive 2,880 hits/day or 0.033 hits/second. If the Web server of the present invention receives a 10 hits/second as a result of viewers accessing client Web sites, the distribution of hits received attributable to the busy, average, and slow Web sites is 50%, 10%, and 3.33%, respectively. If data is cached and flushed at a rate of 1 flush per minute instead updating of the database each time a hit is received, then the database load and network traffic are reduced by a factor of 600, 120, and 2 for the busy, moderate, and slow Web sites, respectively. Post-Session Database. In one preferred embodiment, the present invention includes a relational database for storing member account information and statistical data on focus time. Alternative Media FIGS. 4 to 7, and 9 show one exemplary preferred embodiment of the present invention that uses computers and the Web. This exemplary preferred embodiment is explained in greater detail above. The present invention is well suited to alternative media such as a telephone. For example, a viewer 26 may request a display 34 from a client 20 airline using as media 28 the viewer's telephone. The display 34 consists of the audio communication interface (which may be an actual person or an automated voice response unit) provided by the client 20 airline and the foreground platform 32 consists of a telephone circuit. In this example, the viewer's 26 request for an audio communication interface (e.g., dialing) from the client 20 airline is a load triggering event that causes a post-session procedure to be delivered to media 28 (e.g., the viewer's telephone). When the view triggering event (e.g., hanging up the phone) occurs, the audio communication advertisement is brought to the foreground (e.g., an automatic call back feature) and played. In this example, the post-session procedure requests a post-session platform (a second telephone circuit) which in turn requests a display 30. In this example, display 30 might be an audio communication advertisement provided by a client 20 rental car company or an audio communication advertisement provided by a client 20 lodging provider. The post-session second telephone circuit is sent to the background and does not disrupt the viewer's 26 perception of the audio communication interface 32. It should be noted that the telephone media might not actually be sent to the background, but could wait to run in the background until the view triggering event occurs. Another alternative media is television. For example, a viewer 26 requests a display 34 from a client 20 television broadcaster using television as media 28. The display 34 consists of broadcast content, such as a television program and the foreground platform 32 consists of a television channel. In this example, the viewer's 26 request for display 34 (e.g., television program) is a load triggering event that causes a post-session procedure to be delivered to media 28 (e.g., the interactive television). A view triggering event occurs when the viewer changes the display 34 (e.g., broadcast context), and as a result a post-session platform 24 (e.g., television channel) is brought to the foreground. (It should be noted that the post-session procedure, in this example, causes the post-session platform to be opened upon and sent to the background upon a load triggering event.) In this example, post-session display 30 may consist of an advertisement that is presented within the post-session platform 24. Alternative Embodiments Although the present invention has been discussed in terms of the Internet, alternative media is also contemplated within the scope of the invention. For example, as shown in the exemplary embodiments discussed above, interactive television and wireless communication devices would be ideally suited to the method described in this disclosure. Further, although the terms “Web server,” “Web site,” and “Web page,” are used throughout this disclosure, they are used in the generic sense and are not meant to exclude their equivalent as associated with intranets, LANs, WANS, or alternate media. Alternative embodiments could be developed in which the order of the operations is changed. For example, the function of the script handler 42 may be carried out after the load triggering event. Another example would be one in which the function of the event handler 44 is carried out after the view triggering event. Yet another example would be combining the functions of the script and event handlers so that the post-session platform is opened and sent to the background by the “script handler” prior to the load triggering event. Still another example is one in which the entire system is delayed for a significant period so that the post-session platform and display 24, 30 do not become visible for a predetermined time, a predetermined number of view triggering events, or a specific type of triggering event. The invention could also be implemented by having the post-session platform and display 24, 30 come to the foreground after a predetermined period of time (for example, thirty minutes or two hours), a predetermined number of view triggering events, or a specific type of triggering event. Although the present invention has been discussed as a sequence of steps as shown in FIG. 8, it is contemplated that the functions of the shown steps could be combined into a smaller number of steps or could be expanded to include additional steps and sub-steps. In one preferred embodiment, the functions of opening and sending to the background a post-session platform and display may be performed in a single step. It should noted that although FIG. 1 shows a single client 20, it should be noted that an alternative preferred embodiment contemplates multiple clients. For example, the present invention may be used with a collection of independent Web sites related by a common theme (e.g. Web sites featuring Thai cooking, a Thai restaurant, travel to Thailand, the Thai language, the Thai religion, and Thailand). The present invention may also be used with a network of related sites. For example, a commercial enterprise with several lines of business may have a Web site for each line of business, such as food products, cooking supplies, a travel agency, and a book seller. These commonly owned Web sites featuring different topics could jointly use the present invention. It should be noted that in one preferred embodiment, a client 20 registers to use the system by accessing a Web server 22. A client 20 registering to use the present invention provides the Web server 22 with information such as client name, company name, address, e-mail address, telephone address, line of business, planned advertising budget, estimated daily traffic, Web site information, and other similar information. In a first alternate preferred embodiment, a client 20 uses the present invention without registering. In a second alternate preferred embodiment, a client 20 uses the present invention for free. In another preferred embodiment, the client 20 registers for a fee. As has been discussed above, a load triggering event causes a post-session platform to be opened and immediately sent to the background. It should be understood that the term “immediately” ideally means instantaneously or without any perceptible time delay. But this term may also mean a momentary time delay that is perceptible so long as the delay does not disturb the viewer's viewing experience. As shown in FIG. 8, a load triggering event 58 causes a post-session platform to open 60 and also causes the post-session platform to request a post-session display 62. In one preferred embodiment, the event handler 44 returns a link to a single post-session display 45b, 64. In alternative embodiments, the post-session display may be refreshed one or more times. In other words, the event handler may deliver multiple links to the post-session platform that are downloaded at periodic intervals while the post-session platform remains in the background. In these alternative embodiments, the post-session display may be refreshed even though a new load triggering event has not occurred. The terms and expressions that have been employed in the foregoing specification are used as terms of description and not of limitation and are not intended to exclude equivalents of the features shown and described or portions of them. The scope of the invention is defined and limited only by the claims that follow. | <SOH> BACKGROUND OF THE INVENTION <EOH>The post-session Internet advertising system of the present invention is a system and method for delivering displays to viewers browsing displays with platforms, for exchanging traffic between platforms, and for accurately tracking focus time on display content. Web pages can be created using Hypertext Mark-up Language (“HTML”) and Extensible Mark-up Language (“XML”). HTML is a text-based set of instructions (known as “tags”) that describe the layout of elements on a Web page. HTML can also be used to create “links” (generally, a highlighted word, phrase or graphic image that points to a target such as another Web page) on the World Wide Web. XML consists of a set of tags that abstractly describe data, which can be translated into HTML using standard tools. In addition, a Web page can be divided into subpages (using Frames, an HTML extension). A frameset is the set of subpages that together comprise a Web page. (For example, a Web page may be divided horizontally creating a frameset of two subpages comprising the top and bottom half of the Web page). In addition to its use in creating Web pages, HTML and XML can be used to create advertising for the Internet. The developer or maintainer of a Web site can insert HTML or XML code in their Web pages so that when potential customers view the Web page an advertisement and a link to another Web site is displayed. Web pages and Internet advertising may be enhanced by small programs written in the Java language that are built into a Web page to perform a specific function (such as displaying an animation), often referred to as “applets.” In addition, scripting languages such as JavaScript or VBScript are used to enhance the capabilities of Web pages by performing functions that are beyond the scope of HTML and XML, such as popping up special windows in response to mouse clicks. Scripting languages include an event driven model responsive to changes in a client's state and an Application Programmer's Interface for defining custom behaviors to be followed in response to such “events.” Another technique often used by Web site developers and Internet advertisers is to place a text file on the hard disc of a client when the user visits a Web site. These text files, referred to as “cookies,” are retrieved and read on subsequent visits that a user makes to the Web site. Cookies can be used to track the behavior of site visitors. The economic potential of the Internet is enormous, but the medium is still in its early stages of development. Revenue is directly proportional to the volume of qualified potential customers (“traffic”) that reach and view a commercial Web site. Each visit (often referred to as a “hit”) to a commercial Web site has economic value. Thus, the primary goal of Internet marketing is generating traffic. A secondary goal is to get potential customers to make purchases or otherwise use a commercial Web site (i.e., “capture traffic”). Traffic is more difficult to generate than it is to capture. Further, investment made to generate traffic produces a greater economic return than investment made to capture traffic. A company can a spend a lot of money on effective Web site design so that potential customers will have a rewarding experience and thus a higher inclination to make a purchase once the customer has reached the Web site. But investment in Web site design is wasted unless the site is actually visited. A third goal is “branding,” or increasing consumer awareness or recognition of a brand. In order to meet these goals, most Internet businesses use interrupting advertisements such as pop-up windows, or space consuming advertisements (or “real estate” consuming advertisements) such as banner advertisements, link exchanges, and banner exchanges. Other Internet businesses use alternative advertising methods such as bulk e-mail. Although interrupting advertisements guarantee that a user will see the advertisement for at least a split second, if only to locate the icon used to close the window, these interrupting advertisements are particularly offensive to potential customers because they force the user's attention to be diverted. Most users simply close the window of an interrupting advertisement. Space consuming advertisements, on the other hand, are so pervasive that they have become “white noise.” Usually, a viewer focuses his attention on the information he needs from the Web page and ignores the space consuming advertisement. Alternative advertising methods are similarly problematic. With pop-up window advertising, a separate window of a Web browser is displayed “on top” or “in front” of the Web page being viewed. The advertisement, which may be larger, smaller, or the same size as a banner advertisement, is displayed in the new browser window. Pop-up window advertising has the advantage (for the Web site designer) of displaying an advertisement without having to change the layout of the Web page displaying the advertisement. But potential customers commonly consider the pop-up aspect disruptive and annoying. Banner advertising, a space consuming advertising method, is currently the primary method of advertising on the World Wide Web. Banner advertising relies on HTML and some of the techniques used to create a Web site. Site maintainers insert HTML code in their Web pages that causes a small advertisement (approximately 0.5″ times 2″ on the average screen) to appear in a frame on the Web page, i.e., a “banner advertisement.” The HTML code also contains a link to another site. In short, when potential customers view a Web site with banner creating HTML code, a banner advertisement and link are displayed on the Web page. The more traffic a Web sites has, the more it can charge for displaying banner advertisements. The reason is that a banner advertisement placed on a high volume site generates a lot of traffic for the advertised Web site. In theory, this is advantageous for both parties. But market research shows that as use of the Internet becomes widespread, banner advertisements are becoming less effective. The average potential customer is becoming jaded because banner advertisements appear on almost every Web site. A measure of the effectiveness of Internet marketing is the CTR, or click-through ratio. CTR is the ratio of the number of times an advertisement is exposed to the number of hits generated by the advertisement when viewers “click through” to the advertised site. The trend is that CTRs for banner advertisements are dropping. Link exchanges are another space consuming advertising method for generating Web traffic. A link exchange is an arrangement whereby a first Web site puts a link on its site to a second Web site. In exchange, the second Web site places a link on its site to the first Web site. In addition to exchanging links, a fee may be paid by one site to the other. Each link to the other site is generally placed in a prominent place on the referring Web site. Effectively, a link exchange is a mechanism for sharing traffic between two Web sites. Alternatively, links may not be exchanged. Instead, a first Web site pays a second Web site to put a link to it on the second Web site. Link exchange advertising has the advantage of lower cost than other advertising methods. In fact, a link exchange may be free. In addition, any consideration paid for a link exchange or link placement is generally much lower than that for banner advertisements. A drawback of link exchanges is that their effectiveness varies. The effectiveness depends on where the link is placed, whether there is an image associated with it (thus blurring the line between a link exchange and a banner advertisement), and how much traffic each site receives from other forms of marketing. Market research shows that CTRs on link exchanges are consistently lower than CTRs for banner advertising. Banner exchanges are a hybrid of banner advertising and link exchanges. A Web site joins a Web site syndicate and adds special banner advertisement HTML code to its Web site. The special HTML code causes a banner advertisement for and a link to a syndicate member Web site to be displayed. Typically, the banner advertisement varies so that an advertisement for each syndicate member is alternately displayed. A syndicate may be joined for free or for a nominal fee. In exchange for displaying banner advertisements, banner advertisements for the member's Web site are displayed on the Web sites of other members. In addition, the company managing the exchange syndicate will usually have paid advertisers as members. Fees paid by such advertisers represent a source of revenue for the company managing the exchange syndicate. A limitation of banner exchanges is that they are still fundamentally banner advertisements and as such are experiencing the same declining CTRs as conventional banner advertisements. Bulk e-mail is an alternative advertising method that has a reasonable return on investment but potential customers generally regard it unfavorably. If the bulk e-mail message is read, it may effectively generate traffic. But it is far more likely that the potential customer immediately identifies the message as a “UBE” (unsolicited bulk e-mail), sends complaints to the sender and to their connection provider, and deletes the message unopened and unread. Two events that are important to understanding the experience of a viewer browsing the Web are the “focus” and “blur” events. Typically, a viewer accesses the Internet using a platform, such as a Web browser, on media, such as a computer. For example, a viewer accessing the Internet using the Internet Explorer™ Web browser as a platform on media consisting of a computer running the Windows™ operating system observes the platform as appearing in a window. Focus and blur describe states of a window. A focus event occurs if a window is selected so that it may currently receive input from a viewer. A blur event occurs if focus is removed from a window. While it is possible to simultaneously have multiple windows open, only one window may have focus at any time. If a window is in the focus state, it always fully visible (i.e., it appears “on top” of other open windows) and is sometimes referred to as the “active” window. Windows that are in the blur state are said to be in the “background” and are at least partially obscured by the window in the focus state. A viewer “clicks on” or otherwise selects a window to create a focus event. Alternatively, a computer program may cause a focus event. A focus event may also be referred to as a “view triggering event.” With known Web marketing techniques there is no way of knowing if an advertisement has been seen by the potential customer. A banner advertisement, pop up window, or other Internet advertisement may appear at length in an active window and be fully visible, or may appear only momentarily in an active window and be at least partially obscured for most of the period it is displayed. The time an advertisement is displayed in an active window is called “focus time.” Known techniques do not verify the focus time of an advertisement that has been delivered to a potential customer. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>The post-session Internet advertising system of the present invention is a system and method for delivering displays to viewers browsing displays with platforms, for exchanging traffic between platforms, and for accurately tracking focus time on display content. This method of content delivery overcomes many of the inherent limitations of known Internet based advertising methods. The present invention is directed to a post-session advertising system that may be used in media such as computers, personal digital assistants, telephones, televisions, radios, and similar devices. In one preferred embodiment, a first display is viewed in a first platform in the foreground of a media by a viewer. Then, a load triggering event is initiated by the viewer. Next, in response to the load triggering event, a post-session platform is opened to display a post-session display in the background of the media. Significantly, in the preferred embodiment, the post-session platform stays in the background until a view triggering event occurs. The type of platform and display used will depend significantly on the media. In one preferred embodiment of the present invention an optional focus timer is activated by the view triggering event to allow an accurate assessment of the actual time a viewer focuses on the display in the post-session platform. In another alternate preferred embodiment of the present invention, the number of post-session platforms is limited to, for example, one platform. Multiple load triggering events would either be ignored or would cause the display to refresh (or change) in the already loaded post-session platform. The computer and the Internet are exemplary media that might be used in the present invention. In this exemplary embodiment, Web browsers are the platforms. Further, in this exemplary embodiment, Web sites and advertisements are exemplary display content. More specifically, while a participating Web site (display content) is being visited by a viewer using a first Web browser (platform), a second or post-session Web browser (platform) loads with a second or post-session advertisement (display content) upon a first or load triggering event such as exiting the specific Web page. The post-session Web browser does not disrupt the viewer's browsing experience in his first Web browser. Instead, a second or view triggering event, such as closing the first Web browser, allows the post-session Web browser (and the advertisement thereon) to be viewable by the viewer. The present invention may also monitor the period of time that the advertisement appears in the now active post-session Web browser and provides statistical information to advertisers. The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings. | 20040223 | 20080610 | 20050127 | 74018.0 | 2 | WASSUM, LUKE S | POST-SESSION INTERNET ADVERTISING SYSTEM | SMALL | 1 | CONT-ACCEPTED | 2,004 |
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10,784,781 | ACCEPTED | Previewing a new event on a small screen device | Method and apparatus for previewing new eve in a computing device having a plurality of applications for managing respective events are described. Individual applications are each represented by an application icon on a screen of a graphical user interface for the device. When a new event occurs, particularly when the new event relates to a specific one of a plurality of similar applications, the invention provides a convenient way to denote which application relates to the event. In response to a new event of a one of the applications, the application's icon is visually modified to notify of the new event. A visual modification may be determined in response to the new event, for example, to preview a content of the event. The visual modification may include a count of all new events that remain to be disposed. On a selection of the visually modified icon, additional previewing may be provided. Activation of the application having a visually modified application icon may be configured to automatically initiate the application at the new event. | 1. In a computing device having a plurality of applications for managing respective events, individual ones of said applications each represented by an application icon on a screen of a graphical user interface for the device, a method for previewing new events on the screen comprising: in response to a new event of a one of said applications, visually modifying the one of said applications' icon to notify of the new event. 2. The method of claim 1 comprising invoking the one of said applications in response to the visually modified icon. 3. The method of claim 1 comprising monitoring the one of said applications to determine an occurrence of the new event. 4. The method of claim 1 comprising: determining a visual modification for the one of said applications' icon in response to the new event; and using said visual modification when visually modifying. 5. The method of claim 4 wherein said determining a visual modification comprises maintaining a count of new events for the one of said applications. 6. The method of claim 1 wherein said visually modifying the one of said applications' icon comprises displaying a preview of a content of the new event. 7. The method of claim 6 wherein said act of displaying a preview is responsive to a user action. 8. The method of claim 7 wherein said displaying a preview of a content comprises displaying a dialog box over a portion of the screen. 9. The method of claim 1 comprising in response to an activation of the one of said applications having its icon visually modified to notify of the new event, automatically navigating through the one of said applications to the new event. 10. The method of claim 1 wherein said device comprises at least one of a data communication device and a voice communication device; wherein at least some of said plurality of applications manage communications capabilities associated with the device and-wherein said events of said at least some of said plurality of applications comprise communication events. 11. The method of claim 10 wherein said device comprises a wireless handheld device. 12. In a computing device having a controller coupled to a memory, the memory storing a plurality of applications for managing respective events, a graphical user interface (GUI) for the applications, the GUI comprising: a main screen for displaying on the computing device, the screen comprising a plurality of icons, each icon associated with one of the plurality of applications; at least one monitoring component to determine the occurrence of new events of the applications; and at least one icon modifying component to modify a one of the icons for display on the main screen in response to a new event of the application associated with the one of the icons to notify of the new event. 13. The GUI of claim 12 wherein said GUI maintains a count of new events for respective applications and said icon modifying component modifies in response to said count. 14. The GUI of claim 12 wherein the icon modifying component displays a preview of a content of the new event. 15. The GUI of claim 14 wherein the display of a preview is in response to a user interaction with the one of the icons. 16. The GUI of claim 15 wherein said display of a preview comprises displaying a dialog box over a portion of the main screen. 17. The GUI of claim 12, wherein in response to a user interaction with the one of the icons, said GUI invokes the application associated with the one of the icons to display the new event. 18. The GUI of claim 12 wherein said computing device comprises at least one of a data communication device and a voice communication device; wherein at least some of said plurality of applications manage communications capabilities associated with the computing device and wherein said new events of said at least some of said plurality of applications comprise communication events. 19. The GUI of claim 18 wherein said computing device comprises a wireless handheld device. 20. A wireless handheld device comprising: a controller; a memory coupled to the controller, the memory storing a plurality of applications for execution by the controller to manage respective events and a graphical user interface (GUI) for the applications, the GUI comprising: a main screen for displaying on the device, the screen comprising a plurality of icons, each icon associated with one of the plurality of applications; at least one monitoring component to determine the occurrence of new events of the applications; and at least one icon modifying component to modify a one of the icons for display on the main screen in response to a new event of the application associated with the one of the icons to notify of the new event. | CROSS-REFERENCE TO RELATED APPLICATION This application claims the benefit of U.S. Provisional Patent Application No. 60/525,959 filed Dec. 01, 2003. FIELD OF THE INVENTION The present invention relates generally to wireless communication devices, and more particularly to a graphical user interface for controlling such devices. DESCRIPTION OF THE RELATED ART With the proliferation of communications services available on wireless mobile devices, it becomes increasingly complex to create a single device that can excel at many different functions. Many critics claim that a wireless telephone device can never make a good handheld personal digital assistant (PDA) device and a handheld PDA device will never make a good wireless telephone. It is also said that only teenagers are using Instant Messaging (IM) services or Short Message Services (SMS) to exchange messages with friends and acquaintances and that such users should get an entirely different wireless mobile device. However, many users of wireless handheld devices desire to have multiple services and functionality on a single device. Representing multiple services and functions to a user on a single wireless mobile device presents a number of challenges to the designer of a user interface, particularly a graphical user interface (GUI), for controlling the device. Wireless devices are usually small relative to less portable computing devices such as laptops and desktop computers. Inherently then, a visual display such as an LCD or other screen component of the wireless mobile device has a small display area. Typically, GUIs for wireless mobile devices comprise a main or home screen and one or more sub-screens that may be navigated from the main screen. Notification icons are often rendered on a portion of the main screen to indicate a new event such as the receipt of a new IM message, electronic mail (e-mail) or other service event such as a calendar reminder or alarm and other status information such as time, date and battery life. For each type of service or function available via the device, a graphical image or icon is often rendered on a major portion of the main screen, which icon may be selected using a cursor or other means to launch a specific GUI for the selected service or function. A user may subscribe to multiple similar services and have these services available via a single wireless mobile device. For example, a user may subscribe to more than one Instant Message-type service, such as AOL™ Instant Messenger (AIM™), ICQ™, Microsoft Network™ (MSN™), Yahoo!™ Messenger and Quick Messaging™. Alternatively or as well, a user may have a corporate and personal e-mail account coupled to the wireless mobile device. When a user is notified of a new event such as a new IM message, the user is required to check each of their IM service applications separately, via their respective activation icons, to determine which IM service is responsible for the new event. Checking each service is inconvenient. Moreover, there is a demand to have information made available to a user quicker than previously available in order to optimize the control of the wireless device. Accordingly, there is a resulting need for a method and apparatus that addresses one or more of these shortcomings. SUMMARY The invention relates to a method, graphical user interface and apparatus for notifying and previewing a new event on a display of a device. In accordance with a first aspect of the invention, there is provided a method for a computing device having a plurality of applications for managing respective events, individual ones of said applications each represented by an application icon on a screen of a graphical user interface for the device. The method for previewing new events on the screen comprises, in response to a new event of a one of said applications, visually modifying the one of said applications' icon to notify of the new event. In response to the visually modified icon, a user may invoke the one of said applications. The one of said applications may be monitored to determine an occurrence of the new event. Further, the first aspect may comprise determining a visual modification for the one of said applications' icon in response to the new event; and using said visual modification when visually modifying. Determining a visual modification may comprise maintaining a count of new events for the one of said applications and visually modifying the one of said applications' icon may comprise displaying a preview of a content of the new event. Displaying a preview can be responsive to a user action, such as an interaction with the modified icon. Displaying a preview of a content can comprise displaying a dialog box over a portion of the main screen. In one embodiment, the method comprises, in response to an activation of the one of said applications having its icon visually modified to notify of the new event, automatically navigating through the one of said applications to the new event. In one embodiment, the device comprises at least one of a data communication device and a voice communication device and at least some of said plurality of applications manage communications capabilities associated with the device. As such, the events of said at least some of said plurality of applications comprise communication events. For example, the device may be a wireless device. In a second aspect, in a computing device having a controller coupled to a memory, the memory storing a plurality of applications for managing respective events, there is provided a graphical user interface (GUI) for the applications. The GUI comprises a main screen for displaying on the computing device, the screen comprising a plurality of icons, each icon associated with one of the plurality of applications; at least one monitoring component to determine the occurrence of new events of the applications; and at least one icon modifying component to modify a one of the icons for display on the main screen in response to a new event of the application associated with the one of the icons to notify of the new event. In a third aspect there is provided a wireless handheld device comprising a controller; a memory coupled to the controller, the memory storing a plurality of applications for execution by the controller to manage respective events and a graphical user interface (GUI) for the applications. The GUI comprises a main screen for displaying on the device, the screen comprising a plurality of icons, each icon associated with one of the plurality of applications; at least one monitoring component to determine the occurrence of new events of the applications; and at least one icon modifying component to modify a one of the icons for display on the main screen in response to a new event of the application associated with the one of the icons to notify of the new event. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of present invention will now be described by way of example with reference to attached figures, wherein: FIG. 1 is a block diagram which illustrates pertinent components of a wireless communication device which communicates within a wireless communication network in accordance with the prior art; FIG. 2 is a more detailed diagram of a preferred wireless communication device of FIG. 1 in accordance with the prior art; FIG. 3 is an illustration of an exemplary main screen, in accordance with the invention, for a wireless communication device such as the devices of FIGS. 1 and 2; FIG. 4 is an illustration of the main screen of FIG. 3 after a new event; FIG. 5 is an illustration of the main screen of FIG. 4 following a user action; FIG. 6 is an illustration of a change to an IM application icon when the user selects the application icon with the new event; FIG. 7 is an illustration of multiple new events within one application; FIG. 8 is an illustration of further embodiments for previewing new events on the main screen; and FIGS. 9A and 9B are flowcharts which describe a method in accordance with the invention. DETAILED DESCRIPTION Method and apparatus for previewing new events in a computing device having a plurality of applications for managing respective events are described. Individual applications are each represented by an application icon on a screen of a graphical user interface for the device. When a new event occurs, particularly when the new event relates to a specific one of a plurality of similar applications, the invention provides a convenient way to denote which application relates to the event. In response to a new event of one of the applications, the application's icon is visually modified to notify of the new event. A visual modification may be determined in response to the new event, for example, to preview a content of the event. The visual modification may include a count of all new events that remain to be disposed. On a selection of the visually modified icon, additional previewing may be provided. Activation of the application having a visually modified application icon may be configured to automatically initiate the application at the new event. FIG. 1 is a block diagram of a communication system 100 which includes a mobile station 102 which communicates through a wireless communication network 104 symbolized by a station. Mobile station 102 preferably includes a visual display 112, a keyboard 114, and perhaps one or more auxiliary user interfaces (UI) 116, each of which are coupled to a controller 106. Controller 106 is also coupled to radio frequency (RF) transceiver circuitry 108 and an antenna 110. Typically, controller 106 is embodied as a central processing unit (CPU) which runs operating system software in a memory component (not shown). Controller 106 will normally control overall operation of mobile station 102, whereas signal processing operations associated with communication functions are typically performed in RF transceiver circuitry 108. Controller 106 interfaces with device display 112 to display received information, stored information, user inputs, and the like. Keyboard 114, which may be a telephone type keypad or full alphanumeric keyboard, is normally provided for entering data for storage in mobile station 102, information for transmission to network 104, a telephone number to place a telephone call, commands to be executed on mobile station 102, and possibly other or different user inputs. Mobile station 102 sends communication signals to and receives communication signals from the wireless network 104 over a wireless link via antenna 110. RF transceiver circuitry 108 performs functions similar to those of a base station and a base station controller (BSC) (not shown), including for example modulation/demodulation and possibly encoding/decoding and encryption/decryption. It is also contemplated that RF transceiver circuitry 108 may perform certain functions in addition to those performed by a BSC. It will be apparent to those skilled in art that RF transceiver circuitry 108 will be adapted to particular wireless network or networks in which mobile station 102 is intended to operate. Mobile station 102 includes a battery interface (IF) 134 for receiving one or more rechargeable batteries 132. Battery 132 provides electrical power to electrical circuitry in mobile station 102, and battery IF 132 provides for a mechanical and electrical connection for battery 132. Battery IF 132 is coupled to a regulator 136 which regulates power to the device. When mobile station 102 is fully operational, an RF transmitter of RF transceiver circuitry 108 is turned on only when it is sending to network, and is otherwise turned off or placed in a low-power mode to conserve power. Similarly, an RF receiver of RF transceiver circuitry 108 is typically periodically turned off to conserve power until it is needed to receive signals or information (if at all) during designated time periods. Mobile station 102 operates using a Subscriber Identity Module (SIM) 140 which is connected to or inserted in mobile station 102 at a SIM interface (IF) 142. SIM 140 is one type of a conventional “smart card” used to identify an end user (or subscriber) of mobile station 102 and to personalize the device, among other things. Without SIM 140, the mobile station terminal is not fully operational for communication through the wireless network. By inserting SIM 140 into mobile station 102, an end user can have access to any and all of his/her subscribed services. SIM 140 generally includes a processor and memory for storing information. Since SIM 140 is coupled to SIM IF 142, it is coupled to controller 106 through communication lines 144. In order to identify the subscriber, SIM 140 contains some user parameters such as an International Mobile Subscriber Identity (IMSI). An advantage of using SIM 140 is that end users are not necessarily bound by any single physical mobile station. SIM 140 may store additional user information for the mobile station as well, including datebook (or calendar) information and recent call information. Mobile station 102 may consist of a single unit, such as a data communication device, a multiple-function communication device with data and voice communication capabilities, a personal digital assistant (PDA) enabled for wireless communication, or a computer incorporating an internal modem. Alternatively, mobile station 102 may be a multiple-module unit comprising a plurality of separate components, including but in no way limited to a computer or other device connected to a wireless modem. In particular, for example, in the mobile station block diagram of FIG. 1, RF transceiver circuitry 108 and antenna 110 may be implemented as a radio modem unit that may be inserted into a port on a laptop computer. In this case, the laptop computer would include display 112, keyboard 114, one or more auxiliary UIs 116, and controller 106 embodied as the computer's CPU. It is also contemplated that a computer or other equipment not normally capable of wireless communication may be adapted to connect to and effectively assume control of RF transceiver circuitry 108 and antenna 110 of a single-unit device such as one of those described above. Such a mobile station 102 may have a more particular implementation as described later in relation to mobile station 202 of FIG. 2. FIG. 2 is a detailed block diagram of a preferred mobile station 202. Mobile station 202 is preferably a two-way communication device having at least voice and advanced data communication capabilities, including the capability to communicate with other computer systems. Depending on the functionality provided by mobile station 202, it may be referred to as a data messaging device, a two-way pager, a cellular telephone with data messaging capabilities, a wireless Internet appliance, or a data communication device (with or without telephony capabilities). Mobile station 202 may communicate with any one of a plurality of fixed transceiver stations 200 within its geographic coverage area. Mobile station 202 will normally incorporate a communication subsystem 211, which includes a receiver, a transmitter, and associated components, such as one or more (preferably embedded or internal) antenna elements and, local oscillators (LOs), and a processing module such as a digital signal processor (DSP) (all not shown). Communication subsystem 211 is analogous to RF transceiver circuitry 108 and antenna 110 shown in FIG. 1. As will be apparent to those skilled in field of communications, particular design of communication subsystem 211 depends on the communication network in which mobile station 202 is intended to operate. Network access is associated with a subscriber or user of mobile station 202 and therefore mobile station 202 requires a Subscriber Identity Module or “SIM” card 262 to be inserted in a SIM IF 264 in order to operate in the network. SIM 262 includes those features described in relation to FIG. 1. Mobile station 202 is a battery-powered device so it also includes a battery IF 254 for receiving one or more rechargeable batteries 256. Such a battery 256 provides electrical power to most if not all electrical circuitry in mobile station 202, and battery IF 254 provides for a mechanical and electrical connection for it. The battery IF 254 is coupled to a regulator (not shown) which provides power V+ to all of the circuitry. Mobile station 202 includes a microprocessor 238 (which is one implementation of controller 106 of FIG. 1) which controls overall operation of mobile station 202. Communication functions, including at least data and voice communications, are performed through communication subsystem 211. Microprocessor 238 also interacts with additional device subsystems such as a display 222, a flash memory 224, a random access memory (RAM) 226, auxiliary input/output (I/O) subsystems 228, a serial port 230, a keyboard 232, a speaker 234, a microphone 236, a short-range communications subsystem 240, and any other device subsystems generally designated at 242. Some of the subsystems shown in FIG. 2 perform communication-related functions, whereas other subsystems may provide “resident” or on-device functions. Notably, some subsystems, such as keyboard 232 and display 222, for example, may be used for both communication-related functions, such as entering a text message for transmission over a communication network, and device-resident functions such as a calculator or task list. Operating system software used by microprocessor 238 is preferably stored in a persistent store such as flash memory 224, which may alternatively be a read-only memory (ROM) or similar storage element (not shown). Those skilled in the art will appreciate that the operating system, specific device applications, or parts thereof, may be temporarily loaded into a volatile store such as RAM 226. Microprocessor 238, in addition to its operating system functions, preferably enables execution of software applications on mobile station 202. A predetermined set of applications which control basic device operations, including at least data and voice communication applications, will normally be installed on mobile station 202 during its manufacture. A preferred application that may be loaded onto mobile station 202 may be a personal information manager data items relating to the user such as, but not limited to, instant messaging (IM), e-mail, calendar events, voice mails, appointments, and task items. Naturally, one or more memory stores are available on mobile station 202 and SIM 262 to facilitate storage of PIM data items and other information. The PIM application preferably has the ability to send and receive data items via the wireless network. In a preferred embodiment, PIM data items are seamlessly integrated, synchronized, and updated via the wireless network, with the mobile station user's corresponding data items stored and/or associated with a host computer system thereby creating a mirrored host computer on mobile station 202 with respect to such items. This is especially advantageous where the host computer system is the mobile station user's office computer system. Additional applications may also be loaded onto mobile station 202 through network 200, an auxiliary I/O subsystem 228, serial port 230, short-range communications subsystem 240, or any other suitable subsystem 242, and installed by a user in RAM 226 or preferably a non-volatile store (not shown) for execution by microprocessor 238. Such flexibility in application installation increases the functionality of mobile station 202 and may provide enhanced on-device functions, communication-related functions, or both. For example, secure communication applications may enable electronic commerce functions and other such financial transactions to be performed using mobile station 202. In a data communication mode, a received signal such as a text message, an e-mail message, or web page download will be processed by communication subsystem 211 and input to microprocessor 238. Microprocessor 238 will preferably further process the signal for output to display 222, to auxiliary I/O device 228 or both as described further herein below with reference to FIGS. 3-9. A user of mobile station 202 may also compose data items, such as e-mail messages, for example, using keyboard 232 in conjunction with display 222 and possibly auxiliary I/O device 228. Keyboard 232 is preferably a complete alphanumeric keyboard and/or telephone-type keypad. These composed items may be transmitted over a communication network through communication subsystem 211. For voice communications, the overall operation of mobile station 202 is substantially similar, except that the received signals would be output to speaker 234 and signals for transmission would be generated by microphone 236. Alternative voice or audio I/O subsystems, such as a voice message recording subsystem, may also be implemented on mobile station 202. Although voice or audio signal output is preferably accomplished primarily through speaker 234, display 222 may also be used to provide an indication of the identity of a calling party, duration of a voice call, or other voice call related information, as some examples. Serial port 230 in FIG. 2 is normally implemented in a personal digital assistant (PDA)-type communication device for which synchronization with a user's desktop computer is a desirable, albeit optional, component. Serial port 230 enables a user to set preferences through an external device or software application and extends the capabilities of mobile station 202 by providing for information or software downloads to mobile station 202 other than through a wireless communication network. The alternate download path may, for example, be used to load an encryption key onto mobile station 202 through a direct and thus reliable and trusted connection to thereby provide secure device communication. Short-range communications subsystem 240 of FIG. 2 is an additional optional component which provides for communication between mobile station 202 and different systems or devices, which need not necessarily be similar devices. For example, subsystem 240 may include an infrared device and associated circuits and components, or a Bluetooth™ communication module to provide for communication with similarly-enabled systems and devices. Bluetooth™ is a registered trademark of Bluetooth SIG, Inc. In accordance with an embodiment of the invention, mobile station 202 is configured for sending and receiving data items and includes a PIM for organizing and managing data items relating to the user such as, but not limited to, instant messaging (IM), e-mail, calendar events, calendar appointments, and task items, etc. By way of example, mobile station 202 is configured for three instant messaging services and two e-mail services to which the user subscribes. To provide a user-friendly environment to control the operation of mobile station 202, PIM together with the operation system and various software applications resident on the station 202 provides a GUI having a main screen and a plurality of sub-screens navigable from the main screen. Referring now to FIG. 3, there is an illustration of an exemplary main screen 300, in accordance with an embodiment of the invention, for display 222 of mobile station 202 providing a graphical user interface for controlling mobile station 202. Main screen 300 is divided into two main portions, namely an application portion 301 for displaying and manipulating icons (e.g. 304-312) for various software applications and functions enabled by mobile station 202 and a mobile station status portion 302 for displaying status information such as time, date, battery and signal strength, etc. FIG. 3 illustrates three icons 304, 306 and 308 for respective IM applications IM 1, IM 2 and IM 3 and two icons 310, 312 for the two e-mail services Email 1 and Email 2. Associated with each icon is a name (e.g. IM 1) for the application for icon 304. The name may also be presented in a name region 314 of application portion 301. Main screen 300 may not represent all application icons at once in application portion 301. A user may be required to navigate or scroll through the icons of application portion 301 to view additional application icons. For simplicity, each icon is represented as a circle but persons of ordinary skill in the art will appreciate that other graphics may be used. In the exemplary main screen and GUI of mobile station 202, when a particular icon, e.g. 304, is selected or made active by a user (such as by manipulating keyboard 232 or other auxiliary I/O device 228), the icon 304 is changed such as by highlighting, shadowing or the like. In accordance with an embodiment of the invention, an icon (e.g. 304) may be visually modified in response to a new event from the application associated with the icon to provide an immediate notification of the event via a change in main screen 300. The notification may distinguish the icon from icons for similar services to assist a user to control mobile station 202 as described further. Each of the icons in the main screen 300 of FIG. 3 is in an initial state indicating no new events have occurred and remain unattended by the user. FIG. 4 is an illustration of the main screen 300 after a new IM event, for example, a new message, has arrived into one of the IM applications, namely IM 2, associated with icon 306. In this exemplary embodiment, the new IM message is indicated with a visual modification 400 comprising a bubble, alluding to new received text, and a numeric indicator “1” representing a count of new events, which in this case are unread messages. Persons of ordinary skill in the art will appreciate that a visual modification 400 different from a bubble may be used and the count may represent other information, such as the number of correspondents or “buddies” from which one or more messages have been received but remain unread. In addition to indicating the number of unread messages, this mechanism may be used to reflect other new event information such as additional state information pertaining to the associated application. State information may include whether the user is currently signed in (and their user name), the state of the connection, and the current state of the user (away vs. available). In an e-mail application, such as associated with one of icons 310, 312, a count may be of unread e-mail messages or distinct senders of unread e-mail. Similar counts may represent SMS messages, appointments, alarms or other events for respective applications. Optionally, the count may be configurable for each application or instance thereof. For application icon 304 it may identify the number of distinct senders of unread IM messages and for application icon 308 distinct unread IM messages. FIG. 5 is an illustration of IM application icon 306 following a user action. When the user of mobile station 202 moves the focus of main screen from icon 304 through 306 and 308 to highlight phone icon 502, visual modification 400 persists at icon 306 to maintain the visual modification and remind the user of the unread message. Preferably, only once the user activates an application and reads the unread message is the visual modification changed, for example, to decrease the count and, if applicable, remove the modification if the count is zero. FIG. 6 is an illustration of main screen 300 when IM application icon 306 having an unread message is highlighted. Upon selection of icon 306, in addition to highlighting the icon, a dialog box 602 comprising a message preview 604 of at least a portion of the unread message is displayed. The opening of the dialog box 604 may be briefly delayed after icon 306 is brought in focus by the user. If a dialog box is opened too quickly as a user navigates among the icons, navigation may be preempted before the user navigates to a particular icon of choice. Dialog box 604 is opened at name region 314 though persons skilled in the art will recognize that another region may be selected to position the dialog box 604. By way of example, message preview 604 in dialog box 602 shows the application service (i.e. “AIM” for AOL Instant Messenger) the correspondent sending the message (i.e. “red98”) and a part of the unread message (i.e. “See you at 4:00 . . . ”). FIG. 7 shows a dialog box 602 for an IM application 306 having two unread messages indicated at visual modification 400. Dialog box 602 comprises message previews 604 and 704. Due to the inherent size of main screen 300 and other considerations apparent to those skilled in the art, there is an upper limit to the number of unread messages that may be previewed in such a manner. This limit may be optionally configurable by a user within a predetermined range or simply configured to a maximum size based on the available screen space, font, etc. Optionally, in accordance with an embodiment of the invention, a user may be enabled to “jump” (i.e. automatically navigate) to the unread message directly from the application icon on the main screen, eliminating any intervening screens that may normally be navigated to read messages when navigating the GUI for the associated application. For example, highlighted icon 306 may be activated as per normal (e.g. selecting “enter” on keyboard 232) and the application initiated to start at an unread message (e.g. most or least recent). The application's initial screen or buddies list may be skipped. The opportunity to “jump” may be time-limited and enabled only for a short period of time immediately following the occurrence of the new event, such as from about a few seconds to about 30 seconds. The “jump” activation anticipates the user's need to see the unread message. FIG. 8 is an illustration of another embodiment for previewing events on a main screen of a mobile station such as station 202. In this embodiment, two new events, one for each of IM application icons 304, 306 are indicated via respective visual modifications 802 and 804. Visual modification 802 comprises an event count, namely a count of unread messages and a message preview providing a sender identity and a portion of the unread message. Similarly though differently modification 804 comprises an event count and state preview indicating IM correspondent buddy Tom has signed on. Persons of ordinary skill in the art will appreciate that different events may be visualized on the main screen in accordance with the invention and these events may depend upon the associated application. However, options may be selectively configurable. FIGS. 9A and 9B are flowcharts which describe a method in accordance with the invention for the visual modification of an application icon to represent a new event. FIG. 9A represents operations 900 for identifying a new event to determine the modification and FIG. 9B represents operations 901 to display the modification. Operations 900 may be enabled for a service or other application such as IM, e-mail, etc. Though not shown events to be monitored (for example, by a monitoring component of the GUI) and visually indicated (for example, by a icon modifying component) upon occurrence are pre-determined in accordance with a type or types of events to be notified and previewed. For example, for operations 900 for use in accordance with IM, whether the count is to count distinct unread messages or senders is pre-determined. Beginning at a start block 902 of FIG. 9A, operations 900 commence and the application represented by the application icon to be modified is monitored for a new event (step 904). Persons of ordinary skill in the art will understand that monitoring may be implemented in a number of fashions depending, in part, on operating system and other system services and the interface between communication subsystem 211 and microprocessor 238. Each of the plurality of applications to be monitored may have a dedicated monitoring component to determine the occurrence of respective new events. Alternatively, a single monitoring component could monitor each of the applications. Monitoring may be continuously or intermittently performed repeating step 904, until a new event is determined. Upon a new event, at step 906, the visual modification to the icon to be changed is determined by an icon modifying component. The counter, if any, is incremented and any visual element or graphic to be overlaid may be configured. For example, text may be obtained for the overlay as exemplified by visual modification 802 of FIG. 8. The counter may be decremented if the monitored event is the reading of a previously unread message, for example. User actions that may be performed in association with the modified icon may be set up. For example, text for a dialog box may be obtained in advance and associated with the visual modification for use when the icon is highlighted on the main screen by the user. Should the icon be activated to initiate the application, data to facilitate an immediate automatic jump to the most recent unread message may also be determined in advance if necessary, and associated with the visual modification. The sender of the message may be identified and various user action options prepared for that sender. For example, actions to permit a phone call, e-mail, SMS or other selectable message may be presented to a user highlighting an icon having a visual modification. At step 908, the visual modification and any associated data, as applicable, is identified to a main screen maintenance portion of the PIM GUI or other application responsible for maintaining the main screen as described further with reference to operations 901. The notification may pass an object or other data sharing mechanism to provide the modification and any associated action data. Thereafter, monitoring continues at step 904 of operation 900. Monitoring may continue for as long as station 202 is powered. Beginning at step 910, operations 901 commence for main screen maintenance. At step 912 operations monitor to determine that the main screen is active. If yes, operations monitor for a user action or a notification of a visual modification to an icon (step 914). Upon such an occurrence, a new screen is drawn reflecting the visual modification of an icon or the user's action (step 916, via Yes branch). Exemplary user actions are moving the focus or cursor over the icons of a main screen to highlight an icon or activating an application associated with the icon. The highlighting of an icon that was previously visually modified may further initiate a dialog box display requiring the drawing of the main screen as described above. Once the screen is drawn at step 916 or if no new icon or user activity is detected at step 914, operations 901 repeat at 912. At step 912, if the main screen is no longer active, for example because a user has navigated to another screen, operations 901 may cease (step 918 via No branch) until the main screen is reactivated (not shown). Operations 900 illustrate a method aspect of an embodiment of the invention monitoring events of a single application. As will be understood to those of ordinary skill in the art, mobile station 202 may be configured to have multiple monitors, one for each application, or a single monitor configured to monitor all applications for new events. Alternatively, each type of application could have a monitor for monitoring respective instances of the application type. For example, a single monitor could be configured for monitoring the three IM applications of the above-described embodiment, a further monitor may be configured for the two e-mail applications, a further for the phone application, etc. While operations 910 are illustrated as waiting to be advised of a new visual modification, other initiation mechanisms could be employed. For example, each application or respective monitor therefor could be queried for new visual modifications. Though operation 900 and 901 are described with reference to new events, persons of ordinary skill in the art will appreciate that modifications may be incorporated therein to expire the preview of a new event and display a default or other icon for an application. For example, with reference to FIG. 8, icon 804 illustrates a status event preview, namely the sign-on of Red98. This preview may be expired automatically after a predetermined period of time. A standard or default icon could be used to replace the preview icon. Alternatively, a modified preview icon could be used such as one indicating a count of new events. Similarly, it may be desired to persist some new event previews information even upon the happening of subsequent new events for he same application. For example, new event information relating to a status of the associated application, (e.g. sign-in/out status, availability etc.) may be persisted even as new events occur and are previewed. The above-described embodiments of the present application are intended to be examples only. Those of skill in the art may effect alterations, modifications and variations to the particular embodiments without departing from the scope of the application. The invention described herein in the recited claims intend to cover and embrace all suitable changes in technology. | <SOH> FIELD OF THE INVENTION <EOH>The present invention relates generally to wireless communication devices, and more particularly to a graphical user interface for controlling such devices. | <SOH> SUMMARY <EOH>The invention relates to a method, graphical user interface and apparatus for notifying and previewing a new event on a display of a device. In accordance with a first aspect of the invention, there is provided a method for a computing device having a plurality of applications for managing respective events, individual ones of said applications each represented by an application icon on a screen of a graphical user interface for the device. The method for previewing new events on the screen comprises, in response to a new event of a one of said applications, visually modifying the one of said applications' icon to notify of the new event. In response to the visually modified icon, a user may invoke the one of said applications. The one of said applications may be monitored to determine an occurrence of the new event. Further, the first aspect may comprise determining a visual modification for the one of said applications' icon in response to the new event; and using said visual modification when visually modifying. Determining a visual modification may comprise maintaining a count of new events for the one of said applications and visually modifying the one of said applications' icon may comprise displaying a preview of a content of the new event. Displaying a preview can be responsive to a user action, such as an interaction with the modified icon. Displaying a preview of a content can comprise displaying a dialog box over a portion of the main screen. In one embodiment, the method comprises, in response to an activation of the one of said applications having its icon visually modified to notify of the new event, automatically navigating through the one of said applications to the new event. In one embodiment, the device comprises at least one of a data communication device and a voice communication device and at least some of said plurality of applications manage communications capabilities associated with the device. As such, the events of said at least some of said plurality of applications comprise communication events. For example, the device may be a wireless device. In a second aspect, in a computing device having a controller coupled to a memory, the memory storing a plurality of applications for managing respective events, there is provided a graphical user interface (GUI) for the applications. The GUI comprises a main screen for displaying on the computing device, the screen comprising a plurality of icons, each icon associated with one of the plurality of applications; at least one monitoring component to determine the occurrence of new events of the applications; and at least one icon modifying component to modify a one of the icons for display on the main screen in response to a new event of the application associated with the one of the icons to notify of the new event. In a third aspect there is provided a wireless handheld device comprising a controller; a memory coupled to the controller, the memory storing a plurality of applications for execution by the controller to manage respective events and a graphical user interface (GUI) for the applications. The GUI comprises a main screen for displaying on the device, the screen comprising a plurality of icons, each icon associated with one of the plurality of applications; at least one monitoring component to determine the occurrence of new events of the applications; and at least one icon modifying component to modify a one of the icons for display on the main screen in response to a new event of the application associated with the one of the icons to notify of the new event. | 20040224 | 20120626 | 20050602 | 93026.0 | 2 | HEFFINGTON, JOHN M | PREVIEWING A NEW EVENT ON A SMALL SCREEN DEVICE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,784,984 | ACCEPTED | System and method for maintaining a network connection | A system and method for maintaining a persistent connection is provided. In an embodiment, a system includes a client that connects to a web-server via physical link that is bandwidth-constrained. The physical link also includes at least one network address translation (“NAT”) router that is configured to terminate idle connections between the client and the web-server. The client is configured to send keep-alive packets to the web-server in order to reduce the likelihood of the NAT router terminating the connection. The keep-alive packets are sent on a variable basis that is intended to reduce bandwidth consumption while ensuring that the NAT router does not deem the connection idle and terminate the connection. | 1. An electronic device including a network interface for participating in a network connection with a second device via a network connection carried over physical link that includes equipment for terminating said connection if said connection remains idle according a predefined time-out criteria, said device operable to determine said predefined time-out criteria. 2. The electronic device of claim 1 wherein said electronic device is further operable to send keep-alive signals according to said determined criteria in order to reduce dropped connections by said equipment and reducing overall traffic carried over said link. 3. The device according to claim 2 wherein said connection is an HTTP web-page being requested by said first electronic device of said second electronic device and said keep-alive signal is a no-op signal. 4. The electronic device of claim 1 wherein said equipment is a NAT router. 5. The electronic device of claim 1 wherein said criteria is a predefined time period. 6. The electronic device of claim 5 wherein said device determines said predefined time period by: establishing said connection with an initial default time period; sending a keep-alive signal to said second device once during said time period; increasing said time period if said time period does not cause said connection to be dropped then repeating said sending step; and maintaining a last-known good time period if said time period does cause said connection to be dropped and then reestablishing said connection and returning to said sending step; during which said device sends keep alive signals to said second electronic device, and varying said time period sending keep-alive signals over said connection during said time period for each iteration until said time period causes said equipment to terminate said connection. 7. The device according to claim 6 wherein said device is a client, said second device is a web-server and at least a portion of said link includes the Internet. 8. The device according to claim 7 wherein said client is battery operated and said time periods are increased more quickly as said battery life is depleted to thereby reduce battery consumption while determining said predefined time period. 9. The device according to claim 8 wherein said client is a wireless device and at least a portion of said link includes a wireless connection from said wireless device to the Internet. 10. A method of maintaining a network connection comprising the steps of: loading a timeout criteria into a first electronic device of an initial default value; establishing a connection from said first electronic device to a second electronic device via a physical link that includes equipment for terminating said connection if said connection remains idle for a predefined timeout period; sending keep-alive signals from one said electronic device to the other said electronic device via said equipment according to said timeout criteria; increasing said timeout criteria and repeating said sending step; and, repeating said increasing step until said connection is terminated by said equipment and thereafter performing said sending step using a known good timeout criteria. 11. The method according to claim 10 wherein said at least one least known timeout criteria is a last-known good timeout criteria. 12. The method according to claim 10 wherein said at least one least known timeout criteria is determined by iteratively decreasing said timeout criteria until said connection is no longer terminated. 13. The method according to claim 10 wherein said connection is an HTTP web-page being requested by said first electronic device of said second electronic device and said keep-alive signal is a no-op signal. 14. The method according to claim 10 wherein said equipment is a NAT router. 15. The method according to claim 10 wherein said first device is a client, said second device is a web-server and at least a portion of said link includes the Internet. 16. The method according to claim 10 wherein said client is battery operated and said increasing step is based on larger intervals when said battery life is approaching depletion. 17. The method according to claim 16 wherein said client is a wireless device and at least a portion of said link includes a wireless connection from said wireless device to the Internet. 18. A computer-readable storage medium containing a set of instructions for an electronic device the set of instructions comprising the steps of: loading a timeout criteria into said electronic device of an initial default value; establishing a connection from said electronic device to a second electronic device via a physical link that includes equipment for terminating said connection if said connection remains idle for a predefined timeout period; sending keep-alive signals from said electronic device to said second electronic device according to said timeout criteria; increasing said timeout criteria and repeating said sending step; and, repeating said increasing step until said connection is terminated by said equipment and thereafter performing said sending step using a known good timeout criteria. | FIELD OF THE INVENTION The present application relates generally to computer networking and more particularly to a system and method for maintaining a network connection. BACKGROUND OF THE INVENTION In certain network connections, such as connections made over the Hypertext Transfer Protocol (“HTTP”), it can be desired to maintain a persistent connection between the client and the web-server in order to reduce the overhead needed to reestablish the connection. However, Network Address Translation (“NAT”) gateways and other equipment that lie along the connection pathway may terminate the connection in the event that the connection goes idle beyond a predefined period of time. In order to prevent NAT gateway from terminating the connection, it is known to periodically send “keep-alive” packets from the client to the web-server. Such keep-alive packets do not actually include any transactional information and have no effect of the state of the data between the client and the web-server, and are merely used to prevent the NAT gateway from terminating the connection. It is typical to aggressively send keep-alive packets, without any regard to the actual parameters used by the NAT gateway, and thereby implement a universal strategy to keep the connection open. However, these prior art methods of maintaining persistent connections are ideally suited to channels where bandwidth is not constrained. Thus, in bandwidth constrained mediums, such as wireless network channels, this strategy is wasteful of precious bandwidth. This prior art method is also undesirable in battery operated devices, where aggressive delivery of keep-alive packets could quickly drain the battery. SUMMARY OF THE INVENTION It is an object to provide a novel a system and method for maintaining a network connection that obviates or mitigates at least one of the above-identified disadvantages of the prior art. An aspect of the invention provides a system comprising a first electronic device including a first network interface for participating in a network connection. The system also includes a physical link connected to the first network interface. The physical link is for carrying the network connection. The link includes equipment for terminating the connection if the connection remains idle according to a predefined time-out criteria. The system also includes a second electronic device that includes a second network interface for participating in the network connection via the link. The second electronic device is operable to determine the predefined time-out criteria, and send keep-alive signals to the first electronic device within the parameters of the time-out criteria. The type of time-out criteria that is determined by the second electronic device is not particularly limited. For example, commonly that the time-out criteria is simply a time period of inactivity over the physical link. Another, less common time-out criteria can be in a specially configured Network Address Translation device that located on the physical link that is configured to only time-out the connection if the NAT device requires the resources. Another time-out criteria that is somewhat more common is where there is a non-idle timeout. In this system the NAT device can choose to terminate any connection that is active for more than a predefined period. The second electronic device can be configured to determine which of these criteria (or any other criteria) is being employed along the physical link and respond with a delivery of keep-alive signals so as to reduce the likelihood of the connection being terminated. An aspect of the invention provides an electronic device comprising a microcomputer and a network interface for establishing a network connection with a second electronic device over a physical link. The physical link includes equipment with a timeout period that terminates the connection when the connection is idle. The microcomputer is operable to send keep-alive signals to the second electronic device according to an iteratively changing criteria to establish the timeout period. Thereafter, the microcomputer sends the keep-alive signals within the timeout period and thereby reduces the likelihood of the equipment dropping the connection due to idleness. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described by way of example only, and with reference to the accompanying drawings, in which: FIG. 1 is a schematic representation of a system for maintaining a network connection in accordance with an embodiment of the invention; FIG. 2 is a flow chart depicting a method of maintaining a network connection in accordance with another embodiment of the invention; FIG. 3 shows the system of FIG. 1 during the performance of the method in FIG. 2; FIG. 4 shows set of sub-steps for performing one of the steps in the method of FIG. 2; and, FIG. 5 shows the system of FIG. 1 during the performance of the method in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. 1, a system for maintaining a persistent network connection is indicated generally at 30. In a present embodiment, system 30 includes at least one client 34 that connects to a service provider node 38 via a wireless link 42. Node 38 includes a wireless base station 46 that interacts with client 34 via link 42 and a NAT gateway 50. In turn, gateway 50 connects to the Internet 54 via a backhaul 58. Backhaul 58 can be a T1, T3 or any other suitable link for connecting node 38 to Internet 54. Internet 54, itself, connects to a web-server 62 via a second backhaul 66. In a present embodiment, client 34 is a battery operated device that is based on the computing environment and functionality of a wireless personal digital assistant. It is, however, to be understood that client 34 need not be battery operated and/or can include the construction and functionality of other electronic devices, such as cell phones, smart telephones, desktop computers or laptops with wireless 802.11 or bluetooth capabilities or the like. It is also to be understood that, at least a portion of the connection between client 34 and web-server 62 is bandwidth-constrained. In system 30, since link 42 is a wireless connection that may need to serve a plurality of clients 34, then link 42 is bandwidth constrained in relation to backhaul 58, backhaul 66 and the other elements that compose the connection between client 34 and web-server 62. Such bandwidth constraints can thus interfere with the speed with which a user operating clients 34 can access Internet 54 and web-server 62. Such constraints become particularly acute when a plurality of clients wish to access link 42. Furthermore, judicious use of link 42 by client 34 is desirable due to the fact that client 34 is battery operated. NAT gateway 50 is based on standard NAT technology and thus allows a multiple number of clients 34 connected to node 38 to connect to Internet 54 though a public Internet Protocol (“IP”) address assigned to NAT gateway 50. Accordingly, client 34 (and other clients connected to node 38) will typically have a private IP address, while NAT gateway 50 will have a public IP address accessible to any party on Internet 54. Thus, as client 34 accesses Internet 54, web-server 62 will communicate with client 34 via gateway 50, with gateway 50 “translating” IP addresses during such communication. In an example unique to the present embodiment, client 34 has the private IP address “10.0.0.2”, gateway has the private IP address 10.0.0.1 and the public IP address of “50.0.0.1” and web-server has the public IP address “62.0.0.1”. Like existing NAT gateways, gateway 50 is thus also configured to automatically terminate idle connections between client 34 and Internet 54 in order to free-up resources for NAT gateway 50. Client 34 is configured to maintain a connection between client 34 and web-server 62 notwithstanding the automatic termination feature of gateway 50. More particularly, client 34 is configured to send keep-alive packets during an idle communication period to web-server 50 according to a variable criteria, such keep-alive packets being intended to prevent gateway 50 from dropping the connection between client 34 and web-server 50, but without changing the state of data in client 34 or web-server 62. Such keep-alive packets can be any suitable packet, that achieves this result, such as a “no-op” command, a command that generates a non critical error result in the server or a command designed into the application level protocol as a keep alive mechanism. In a present embodiment, the variable criteria is based on an time period that is arrived upon iteratively. The iterations are considered complete when a time period is established that is substantially close to the maximum amount of time that NAT gateway 50 will allow to lapse before terminating the connection between client 34 and web-server 50. Further understanding about client 34 and this criteria will provided below. In order to help explain certain of these implementations and various other aspects of system 30, reference will now be made to FIG. 2 which shows a method for maintaining a network connection and which is indicated generally at 400. In order to assist in the explanation of the method, it will be assumed that method 400 is operated by client 34 using system 30. However, it is to be understood that client 34, system 30 and/or method 400 can be varied, and need not work exactly as discussed herein in conjunction with each other, and that such variations are within the scope of the invention. Before discussing method 400, it will be assumed that NAT gateway 50 is configured to drop connections where a connection is idle for greater than fifteen minutes (However, other time periods are also within the scope of the invention, according to the configuration of the particular NAT gateway. Such other time periods can be greater than twenty minutes, or greater than thirty minutes, or greater than ten minutes.) It will also be assumed that this timeout period is unknown to client 34 on invocation of method 400. Beginning first at step 410, a set of default criteria is loaded. As will be discussed below, the default criteria that is loaded is used by client 34 to define an initial time period during which keep-alive packets that are sent by client 34 in order to prevent gateway 50 from dropping a connection between client 34 and an entity on Internet 54, but without changing the state of data in client 34 or that entity. In the present example, it will be assumed that the default criteria that is loaded will be a period of five minutes. (Other example default periods can be seven minutes, ten minutes and twelve minutes.) Next, at step 420, a connection is established. Continuing with the present example, it will be assumed that client 34 opens a connection with web-server 62. This example is represented in FIG. 3, wherein a connection is represented by a dotted line indicated generally at 100. The connection is opened in the usual manner, such as by having a web-browser on client 34 open an HTTP web-page that is located on web-server 34. The establishment of connection 100 thus involves having NAT gateway 50 create a mapping of client 34's private IP address to gateway 50's own public IP address. This is represented in FIG. 4 by having gateway 50 represent to web-server 62 that the public IP address of client 34 is “50.0.0.1/8”, wherein “50.0.0.1” is gateway 50's own public IP address, while “/8” represents the individual port on gateway 50 that is mapped to client 34's private IP address of “10.0.0.2”. Thus, traffic carried over connection 100 will be passed through gateway 50 using this mapping. Once connection 100 is opened, network traffic is sent thereover in the usual manner. In general, it is to be reemphasized that this is merely an example and the way in which a connection is established is not particularly limited. Next, at step 430, keep-alive signals are sent according to the established criteria. Since the criteria that was established at step 410 is a period of five minutes, then at step 430 keep-alive signals will be sent from client 34 to web-server 62 every five minutes. Since these keep-alive signals pass through gateway 50, then gateway 50 will only perceive that connection 100 is idle for five minute periods. Since this five minute period is less than the fifteen minute timeout period that gateway 50 will await before terminating connection 100, then gateway 50 will not terminate connection 100 and thus connection 100 will be persistent. Method 400 will then advance to step 440, at which point a determination is made as to whether the connection established at step 420 has been terminated. Since the five minute interval during which client 34 sends keep-alive signals to web-server 62 is less than the previously mentioned fifteen minute timeout period, connection 100 will not be terminated and so it will be determined at step 440 that “no”, connection 100 as not been terminated and method 400 will advance to step 450. At step 450, an adjustment, if any, to the criteria used at step 430 will determined. In a present embodiment, step 450 is carried out over a number of sub-steps, indicated generally at 450 on FIG. 4. At step 451, it is determined whether the connection has ever been terminated. If there has been a prior termination, then the method advances to step 452 and the last known good criteria is maintained, and thus no adjustment is made to the criteria. At this point the method returns to step 430 on FIG. 2. However, if at step 451 it is determined that there has been no prior termination of the connection, then the method advances to step 453 and an adjustment is made to increase the time between delivery of the keep-alive signals. Thus, in the example being discussed herein in relation to connection 100, it will be determined at step 451 that connection has never been terminated, and the method will advance from step 451 to step 4523. At step 453, the criteria will be adjusted to increase the amount of time between delivery of keep-alive signals. The amount and/or rate by which the increase is made at step 453 is not particularly limited. In accordance with the present example, it will be assumed that the time interval will be increased by one-minute each time method 400 advances to step 453. Accordingly, during this cycle through method 400, the time period will be increased to six minutes from five minutes. The method then advances from step 453 back to step 430, at which point the keep-alive signals are sent according to the criteria that has been established at step 453. Since the criteria that was established at step 453 is a period of six minutes, then at step 430 keep-alive signals will be sent from client 34 to web-server 62 every six minutes. Since these keep-alive signals pass through gateway 50, then gateway 50 will only perceive that connection 100 is idle for six minute periods. Since this six minute period is less than the fifteen minute timeout period that gateway 50 will await before terminating connection 100, then gateway 50 will not terminate connection 100 and thus connection 100 will be persistent. Method 400 will thus continue cycle through steps 430, 440 and 450 (i.e. sub-steps 451 and 453) as previously mentioned until the criteria established at step 453 finally adjusts the time interval beyond the timeout period of gateway 50. More specifically, once at step 453 a time period of sixteen minutes is established, then during the next cycle through step 430 the keep-alive signal will be sent outside the fifteen minute time-out period, and thus connection 100 will be terminated. This time, when method 400 reaches step 440, it will be determined that connection 100 has been terminated, and thus method 400 will advances from step 440 to step 460, at which point the last-known good criteria will be loaded. In the present example, the last-known good criteria that was established previously at step 453 will be the time interval of fifteen minutes, and thus at step 460, in this example, client 34 will load the time period of fifteen minutes as the criteria. Method 400 then advances from step 460 to step 420 at which point the connection is established (i.e. re-established). Continuing with the present example, it will be assumed that client 34 reopens a connection with web-server 62. This example is represented in FIG. 5, wherein a new connection is represented by a dotted line indicated generally at 104. The connection is opened in the usual manner, such as by having a web-browser on client 34 open an HTTP web-page that is located on web-server 34. The establishment of connection 100 thus involves having NAT gateway 50 create a mapping of client 34's private IP address to gateway 50's own public IP address. This is represented in FIG. 4 by having gateway 50 represent to web-server 62 that the public IP address of client 34 is “50.0.0.1/9”, wherein “50.0.0.1” is gateway 50's own public IP address, while “/9” represents the individual port on gateway 50 that is mapped to client 34's private IP address of “10.0.0.2”. Thus, traffic carried over connection 104 will be passed through gateway 50 using this mapping. Once connection 104 is opened, network traffic is sent thereover in the usual manner. Method 400 then advances to step 430, at which point the keep-alive signals are sent according to the criteria that has been established at step 460. Since the criteria that was established at step 460 is a period of fifteen minutes, then at step 430 keep-alive signals will be sent from client 34 to web-server 62 every fifteen minutes. Since these keep-alive signals pass through gateway 50, then gateway 50 will only perceive that connection 104 is idle for fifteen minute periods. Since this fifteen minute period is acceptable according to the fifteen minute timeout period that gateway 50 will await before terminating connection 104, then gateway 50 will not terminate connection 100 and thus connection 104 will be persistent. Method 400 will then advance from step 430 to step 440, at which point a determination is made as to whether the connection established at step 420 has been terminated. Since the fifteen minute interval during which client 34 sends keep-alive signals to web-server 62 is acceptable in relation to the fifteen minute timeout period, connection 104 will not be terminated and so it will be determined at step 440 that “no”, connection 104 as not been terminated and method 400 will advance to step 450. At step 450, an adjustment, if any, to the criteria used at step 430 will determined. Recall that in a present embodiment step 450 is carried out over a number of sub-steps, indicated generally at 450 on FIG. 4. At step 451, it is determined whether the connection has ever been terminated. Since the connection between client 34 and web-server 62 has been terminated once already (i.e. since connection 100 was terminated), then the method advances to step 452 and the last known good criteria is maintained, and thus no adjustment is made to the criteria. More specifically, since it is known that the fifteen minute time interval is an acceptable criteria, this criteria is maintained and at this point the method returns to step 430 on FIG. 2. Back at step 430, at which point the keep-alive signals are thus sent according to the criteria preserved at step 452. Since the criteria that was established at step 452 is a period of fifteen minutes, then at step 430 keep-alive signals will be sent from client 34 to web-server 62 every fifteen minutes. Since these keep-alive signals pass through gateway 50, then gateway 50 will only perceive that connection 104 is idle for fifteen minute periods, within the accepted fifteen minute timeout period that gateway 50 will await before terminating connection 100. Thus gateway 50 will not terminate connection 104 and thus connection 104 will be persistent. Method 400 will thus continue cycle as long as needed to maintain a connection between client 34 and web-server 62 during idle period. It should now be apparent that a change in routing of connection 104 (or other change in the physical link between client 34 and web-server 62) could cause the timeout period to change—i.e. decrease over time from the time period that had been previously established through earlier cycles through method 400. For example, if another router in Internet 54 is introduced into the pathway that carries connection 104, and where that router drops idle connections after ten minutes, then method 400 may at various times cycle through step 460 and thereby the connection between client 34 and web-server 62 may be torn down and reestablished several times until at step 460 the criteria is decreased back to a ten minute interval. It is thus contemplated that step 460 can include sub-steps that will continue to decrease the criteria to shorter and shorter time periods until the shortest timeout period for any equipment along the physical link between client 34 and web-server 62 is established, at which point that shortest timeout period will be used at step 430. In this manner, it is contemplated that the criteria used at step 430 may at various times decrease or increase according to the timeout behaviours of the equipment that forms the physical link between client 34 and web-server 62. Also, it is to be understood that, in other embodiments of the invention, normal spurious connection timeouts can be handled by a suitably modified version of method 400. Such a modified version of method 400 can be configured to respond to such spurious connection timeouts. For example a form of weighting or hysteresis can be utilized in a suitably modified version of method 400 that favours time-intervals for delivering keep-alive signals that client 34 has previously found effective in reducing the likelihood connection 104 being terminated. It should also be understood that the rates by which the criteria is adjusted at step 450 and step 460 is not particularly limited. Further, the type of criteria that is used need not be particularly limited. For example the changes in criteria at step 450 and 460 need not be in a linear fashion, and need not be based on simple minute-by-minute increments or decrements. For example, a logarithmic convergence, based on splitting the various time intervals in half, using Newton's Method can be used. As an additional example, it can be desired at steps 450 and step 460 to consider the remaining battery life of client 34, and thus where the battery of client 34 has a long period of remaining life, the criteria adjustment made at step 450 need not be as aggressive. However, where the battery of client 34 has a short period of remaining life, the criteria adjustment made at step 450 may aggressively attempt to have the criteria reach the idle timeout period as fast as possible in order to preserve the battery life of client 34. While only specific combinations of the various features and components of the invention have been discussed herein, it will be apparent to those of skill in the art that desired subsets of the disclosed features and components and/or alternative combinations of these features and components can be utilized, as desired. For example, while not necessary, it is typically contemplated that steps 430-460 are only invoked during time periods that client 34 is aware that connection 100 (or connection 104) is idle, and so method 400 can be modified to cause steps 430-460 to be performed only during those time periods when connection 100 (or connection 104) is idle. Furthermore, it is also to be understood that the origin of the keep-alive packets need not be restricted to client 34. For example, where base station 46 is aware of the need to maintain connection 100 as persistent, then it can be desired to have base station 46 perform steps 430-460 on behalf of client 34 and thereby free up resources on client 34 and link 42. By the same token, it is contemplated that steps 430-460 could also be conducted by web-server 62 on behalf of client 34. In another variation of the invention, it is contemplated that steps 430-460 can be performed by client 34 prior to the establishment of a connection, and thereby determine the appropriate criteria for sending keep-alive signals within the timeout period prior to establishment of the connection and thereby reduce likelihood of termination of the connection. Further, once this timeout period is established, it is contemplated that the period can be reported to other clients attached to node 38, thereby obviating the need for those clients to perform steps 430-460 themselves. While system 30 is directed to a specific type of network, it should be understood that other types of clients, servers, and networks can be used. For example, the invention can be applied to peer-to-peer connections and need not be limited to client/server type relationships. Furthermore the type of physical connections that carry the connection are not limited, and can be based on Ethernet, Intranets, 802.11, bluetooth etc. Additionally, while the embodiments herein are discussed in relation to connections over which at least a portion are bandwidth constrained, it should be understood that the invention is also applicable to connections that are not bandwidth constrained. The above-described embodiments of the invention are intended to be examples and alterations and modifications may be effected thereto, by those of skill in the art, without departing from the scope of the invention which is defined solely by the claims appended hereto. | <SOH> BACKGROUND OF THE INVENTION <EOH>In certain network connections, such as connections made over the Hypertext Transfer Protocol (“HTTP”), it can be desired to maintain a persistent connection between the client and the web-server in order to reduce the overhead needed to reestablish the connection. However, Network Address Translation (“NAT”) gateways and other equipment that lie along the connection pathway may terminate the connection in the event that the connection goes idle beyond a predefined period of time. In order to prevent NAT gateway from terminating the connection, it is known to periodically send “keep-alive” packets from the client to the web-server. Such keep-alive packets do not actually include any transactional information and have no effect of the state of the data between the client and the web-server, and are merely used to prevent the NAT gateway from terminating the connection. It is typical to aggressively send keep-alive packets, without any regard to the actual parameters used by the NAT gateway, and thereby implement a universal strategy to keep the connection open. However, these prior art methods of maintaining persistent connections are ideally suited to channels where bandwidth is not constrained. Thus, in bandwidth constrained mediums, such as wireless network channels, this strategy is wasteful of precious bandwidth. This prior art method is also undesirable in battery operated devices, where aggressive delivery of keep-alive packets could quickly drain the battery. | <SOH> SUMMARY OF THE INVENTION <EOH>It is an object to provide a novel a system and method for maintaining a network connection that obviates or mitigates at least one of the above-identified disadvantages of the prior art. An aspect of the invention provides a system comprising a first electronic device including a first network interface for participating in a network connection. The system also includes a physical link connected to the first network interface. The physical link is for carrying the network connection. The link includes equipment for terminating the connection if the connection remains idle according to a predefined time-out criteria. The system also includes a second electronic device that includes a second network interface for participating in the network connection via the link. The second electronic device is operable to determine the predefined time-out criteria, and send keep-alive signals to the first electronic device within the parameters of the time-out criteria. The type of time-out criteria that is determined by the second electronic device is not particularly limited. For example, commonly that the time-out criteria is simply a time period of inactivity over the physical link. Another, less common time-out criteria can be in a specially configured Network Address Translation device that located on the physical link that is configured to only time-out the connection if the NAT device requires the resources. Another time-out criteria that is somewhat more common is where there is a non-idle timeout. In this system the NAT device can choose to terminate any connection that is active for more than a predefined period. The second electronic device can be configured to determine which of these criteria (or any other criteria) is being employed along the physical link and respond with a delivery of keep-alive signals so as to reduce the likelihood of the connection being terminated. An aspect of the invention provides an electronic device comprising a microcomputer and a network interface for establishing a network connection with a second electronic device over a physical link. The physical link includes equipment with a timeout period that terminates the connection when the connection is idle. The microcomputer is operable to send keep-alive signals to the second electronic device according to an iteratively changing criteria to establish the timeout period. Thereafter, the microcomputer sends the keep-alive signals within the timeout period and thereby reduces the likelihood of the equipment dropping the connection due to idleness. | 20040225 | 20080916 | 20050825 | 93281.0 | 0 | DUONG, OANH | SYSTEM AND METHOD FOR MAINTAINING A NETWORK CONNECTION | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,785,096 | ACCEPTED | Zoom lens system | A zoom lens system having high zoom ratio capable of shifting an image for vibration reduction correction. The system includes, in order from an object, a first lens group having positive power, a second lens group having negative power, a third lens group having positive power, and a fourth lens group having positive power. Each of the first lens group through the fourth lens group moves such that when zooming from a wide-angle end state to a telephoto end state, a distance between the first and the second lens groups increases, a distance between the second and the third lens groups decreases, and a distance between the third and the fourth lens group decreases. The third lens group includes at least two sub-lens groups having positive refractive power. Image shifting carried out by moving either of the two sub-lens groups perpendicularly to the optical axis. Given conditions are satisfied. | 1. A zoom lens system comprising, in order from an object: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; and a fourth lens group having positive refractive power; each of the first lens group through the fourth lens group moving such that; when the state of lens group positions varies from a wide-angle end state to a telephoto end state; a distance between the first lens group and the second lens group increases; a distance between the second lens group and the third lens group decreases; and a distance between the third lens group and the fourth lens group decreases; the third lens group including at least two sub-lens groups having positive refractive power; an image being shifted by moving either of the two sub-lens groups as a shift lens group perpendicularly to the optical axis; and wherein the following conditional expression is satisfied: 0.120<DT/ft<0.245 where DT denotes an air space between the most image side lens surface of the first lens group and the most object side lens surface of the second lens group in the telephoto end state, and ft denotes the focal length of the zoom lens system in the telephoto end state. 2. The zoom lens system according to claim 1, wherein the following conditional expression is satisfied: 0.8<(1−|A)×βB<3.5 where βA denotes the lateral magnification of the shift lens group and βB denotes the lateral magnification of the optical elements locating between the shift lens group and an image plane. 3. The zoom lens system according to claim 2; wherein the third lens group consists of, in order from the object; a third A lens group having positive refractive power; a third B lens group having positive refractive power; and a third C lens group having negative refractive power; and wherein the shift lens group having positive refractive power is the third B lens group. 4. The zoom lens system according to claim 3, wherein the shift lens group includes at least one aspherical surface. 5. The zoom lens system according to claim 3, wherein the third A lens group consists of two positive lenses and one negative lens. 6. The zoom lens system according to claim 3, wherein the third B lens group consists of one positive lens and one negative lens. 7. The zoom lens system according to claim 2, wherein the shift lens group includes at least one aspherical surface. 8. The zoom lens system according to claim 1; wherein the third lens group consists of, in order from the object; a third A lens group having positive refractive power; a third B lens group having positive refractive power; and a third C lens group having negative refractive power; and wherein the shift lens group having positive refractive power is the third B lens group. 9. The zoom lens system according to claim 8, wherein the shift lens group includes at least one aspherical surface. 10. The zoom lens system according to claim 8, wherein the third A lens group consists of two positive lenses and one negative lens. 11. The zoom lens system according to claim 8, wherein the third B lens group consists of one positive lens and one negative lens. 12. The zoom lens system according to claim 1, wherein the shift lens group includes at least one aspherical surface. 13. The zoom lens system according to claim 1, wherein the second lens group includes at least three negative lenses and one positive lens. 14. The zoom lens system according to claim 1, wherein the fourth lens group includes at least one aspherical surface having a shape that positive refractive power becomes weak from the center to the periphery of the lens surface. 15. A zoom lens system comprising, in order from an object: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; and a fourth lens group having positive refractive power; each of the first lens group through the fourth lens group moving such that; when the state of lens group positions varies from a wide-angle end state to a telephoto end state; a distance between the first lens group and the second lens group increases; a distance between the second lens group and the third lens group decreases; and a distance between the third lens group and the fourth lens group decreases; the third lens group including at least two sub-lens groups having positive refractive power; an image being shifted by moving either of the two sub-lens groups as a shift lens group perpendicularly to the optical axis. 16. A zoom lens system comprising, in order from an object: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; and a fourth lens group having positive refractive power; at least the first lens group and the fourth lens group moving to the object side such that when the state of lens group positions varies from a wide-angle end state to a telephoto end state a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group decreases; the third lens group including a first sub-lens group, a second sub-lens group, and a third sub-lens group; the second sub-lens group being arranged to the image side of the first sub-lens group with an air space; the third sub-lens group being arranged to the image side of the second sub-lens group with an air space; an image being shifted by moving the second sub-lens groups shifting substantially perpendicularly to the optical axis; and an aperture stop being arranged in the vicinity of the third lens group, inclusive of inside of the third lens group; wherein the following conditional expressions are satisfied: 0.05<Ds/fw<0.7 0.1<ft/fA<1.5 where Ds denotes a distance along the optical axis between the aperture stop and the nearest lens surface of the second sub-lens group, fw denotes the focal length of the zoom lens system in the wide-angle end state, fA denotes the focal length of the whole lenses locating to the object side of the second sub-lens group in the telephoto end state, and ft denotes the focal length of the zoom lens system in the telephoto end state. 17. The zoom lens system according to claim 16, wherein the first sub-lens group has positive refractive power and the following conditional expression is satisfied: 0.06<fa/ft<0.2 where fa denotes the focal length of the first sub-lens group. 18. The zoom lens system according to claim 17, wherein the second sub-lens group includes at least one positive lens and one negative lens, and has positive refractive power, and wherein the following conditional expression is satisfied: −0.6<(na/ra)/(nb/rb)<0 where ra denotes a radius of curvature of the most object side lens surface of the second sub-lens group, na denotes refractive index at d-line of the most object side lens of the second sub-lens group, rb denotes a radius of curvature of the most image side lens surface of the second sub-lens group, and nb denotes refractive index at d-line of the most image side lens of the second sub-lens group. 19. The zoom lens system according to claim 18, wherein the third sub-lens group has negative refractive power and the following conditional expression is satisfied: 0.5<|fc|/f3<0.9 where fc denotes the focal length of the third sub-lens group, and f3 denotes the focal length of the third lens group. 20. The zoom lens system according to claim 19, wherein the third sub-lens group includes a negative lens having a concave surface facing to the object locating to the most object side and the following conditional expression is satisfied: 0.5<|rc|/f3<0.75 where rc denotes a radius of curvature of the negative lens locating to the most object side of the third sub-lens group. 21. The zoom lens system according to claim 17, wherein the third sub-lens group has negative refractive power and the following conditional expression is satisfied: 0.5<|fc|/f3<0.9 where fc denotes the focal length of the third sub-lens group, and f3 denotes the focal length of the third lens group. 22. The zoom lens system according to claim 21, wherein the third sub-lens group includes a negative lens having a concave surface facing to the object locating to the most object side and the following conditional expression is satisfied: 0.5<|rc|/f3<0.75 where rc denotes a radius of curvature of the negative lens locating to the most object side of the third sub-lens group. 23. The zoom lens system according to claim 16, wherein the second sub-lens group includes at least one positive lens and one negative lens, and has positive refractive power, and wherein the following conditional expression is satisfied: −0.6<(na/ra)/(nb/rb)<0 where ra denotes a radius of curvature of the most object side lens surface of the second sub-lens group, na denotes refractive index at d-line of the most object side lens of the second sub-lens group, rb denotes a radius of curvature of the most image side lens surface of the second sub-lens group, and nb denotes refractive index at d-line of the most image side lens of the second sub-lens group. 24. The zoom lens system according to claim 23, wherein the third sub-lens group has negative refractive power and the following conditional expression is satisfied: 0.5<|fc|/f3<0.9 where fc denotes the focal length of the third sub-lens group, and f3 denotes the focal length of the third lens group. 25. The zoom lens system according to claim 24, wherein the third sub-lens group includes a negative lens having a concave surface facing to the object locating to the most object side and the following conditional expression is satisfied: 0.5<|rc|/f3<0.75 where rc denotes a radius of curvature of the negative lens locating to the most object side of the third sub-lens group. 26. The zoom lens system according to claim 16, wherein the third sub-lens group has negative refractive power and the following conditional expression is satisfied: 0.5<|fc|/f3<0.9 where fc denotes the focal length of the third sub-lens group, and f3 denotes the focal length of the third lens group. 27. The zoom lens system according to claim 26, wherein the third sub-lens group includes a negative lens having a concave surface facing to the object locating to the most object side and the following conditional expression is satisfied: 0.5<|rc|/f3<0.75 where rc denotes a radius of curvature of the negative lens locating to the most object side of the third sub-lens group. 28. A zoom lens system comprising, in order from an object: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; and a fourth lens group having positive refractive power; at least the first lens group and the fourth lens group moving to the object side such that when the state of lens group positions varies from a wide-angle end state to a telephoto end state a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group decreases; the third lens group including a first sub-lens group, a second sub-lens group, and a third sub-lens group; the second sub-lens group being arranged to the image side of the first sub-lens group with an air space; the third sub-lens group being arranged to the image side of the second sub-lens group with an air space; an image being shifted by moving the second sub-lens groups shifting substantially perpendicularly to the optical axis; and an aperture stop being arranged in the vicinity of the third lens group including inside of the third lens group; wherein the following conditional expressions are satisfied: 0.05<Ds/fw<0.7 where Ds denotes a distance along the optical axis between the aperture stop and the nearest lens surface of the second sub-lens group, and fw denotes the focal length of the zoom lens system in the wide-angle end state. | The disclosures of the following priority applications are herein incorporated by reference: Japanese Patent Application No. 2003-051386 filed on Feb. 27, 2003; and Japanese Patent Application No. 2003-341903 filed on Sep. 30, 2003. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zoom lens system and in particular to a high zoom ratio zoom lens system capable of shifting an image. 2. Related Background Art An optical system capable of moving (shifting) an image perpendicularly to the optical axis by moving (shifting) one or some of lens elements constructing the optical system substantially perpendicularly to the optical axis has been known. As for such optical systems, a zoom lens system capable of shifting an image by shifting one or some of lens elements provided in the zoom lens system has been proposed (see, for example, Japanese Patent Application Laid-Open No. 2003-140048 and Japanese Patent Application Laid-Open No. 2-081020). In the present specification, one or some of lens elements being shifted substantially perpendicularly to the optical axis is hereinafter called a shift lens group. Recently, a zoom lens has widely used as a photographic lens. When a zoom lens is used as a photographic lens, it makes you possible to take a photograph closer to the subject, so it has a merit that you can take a photograph just as you intend. According to popularization of a zoom lens as a photographic lens, a high zoom ratio zoom lens capable of shooting closer to the subject has come onto the market. As a high zoom ratio zoom lens capable of shooting closer to the subject, a positive-negative-positive-positive four-lens-group type zoom lens has been known (see, for example, Japanese Patent Application Laid-Open No. 2001-117005 and Japanese Patent Application Laid-Open No. 11-142739). A positive-negative-positive-positive type zoom lens is composed of, in order from the object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power. When the state of lens group positions varies from a wide-angle end state (which gives the shortest focal length) to a telephoto end state (which gives the longest focal length), at least the first lens group and the fourth lens group move to the object side such that a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group decreases. According to further popularization of a zoom lens as a photographic lens, in order to meet user's expectation to improve portability, compact and lightweight zoom lenses have been proposed. On the other hand, in particular for a compact and lightweight zoom lens, an image tends to be blurred during exposure by minute vibration produced on a camera while shooting such as a camera shake caused by a photographer upon releasing a shutter button. When the amount of the camera vibration is assumed to be constant, the amount of image blurring increases in accordance with the increase in the focal length of the lens, so the minute camera vibration causes severe deterioration on the image. Accordingly, a method for compensating the above-described image blur caused by the camera shake by combining a zoom lens capable of shifting an image with a driver, a detector and a controller has been known (see, for example, Japanese Patent Application Laid-Open No. 10-282413). In such zoom lens, the detector detects a camera shake. The controller controls the shift lens group giving the driver a driving amount in order to correct the shake detected by the detector. The driver corrects the image blur caused by the camera shake by driving the shift lens group substantially perpendicularly to the optical axis. Generally, in a zoom lens, it is necessary to correct various aberrations for each lens group to obtain given optical performance as a whole zoom lens. The state of aberration correction required to each lens group has a certain range, and the range generally becomes narrow when the zoom ratio becomes large. On the other hand, in an optical system capable of shifting an image, in order to suppress variation in various aberrations produced upon shifting an image, there is a state of aberration correction required for the shift lens group only. Accordingly, the state of aberration correction required for the shift lens group in order to obtain good optical performance when the zoom ratio becomes large is completely different from that required for the shift lens group in order to correct aberrations produced upon shifting an image to obtain good optical performance. Therefore, it is very difficult to combine to attain a high zoom ratio and to construct an optical system capable of shifting an image. A conventional zoom lens having vibration reduction correction disclosed in Japanese Patent Application Laid-Open No. 2003-140048, however, has a large number of lens elements, and a vibration reduction mechanism has to be put into the lens barrel. Accordingly, the total lens length and the diameter of the lens barrel become large, so the compactness tends to be spoiled. Moreover, when the zoom lens is made to be a high zoom ratio with having a vibration reduction correction, deterioration in optical performance is severe, so that it becomes difficult to maintain sufficient optical performance as a zoom lens. A zoom lens disclosed in Japanese Patent Application Laid-Open No. 10-282413 has a large number of lens elements, so that when the state of lens group positions varies from the wide-angle end state to the telephoto end state, degree of freedom for selecting zoom trajectory of each lens group is large. Accordingly, high optical performance can be obtained. However, the driving mechanism for moving each lens group becomes complicated and the factors to produce mutual decentering of each lens group upon manufacturing increase, so that it becomes difficult to secure stable optical performance. SUMMARY OF THE INVENTION The present invention is made in view of the aforementioned problems and has an object to provide a high zoom ratio zoom lens capable of shifting an image, which can carry out vibration reduction correction and accomplish a high zoom ratio. According to one aspect of the present invention, a zoom lens system includes, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power. Each of the first lens group through the fourth lens group move such that when the state of lens group positions varies from a wide-angle end state to a telephoto end state, a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group decreases. The third lens group includes at least two sub-lens groups having positive refractive power. An image is shifted by moving either of the two sub-lens groups as a shift lens group perpendicularly to the optical axis. The following conditional expression (1) is satisfied: 0.120<DT/ft<0.245 (1) where DT denotes an air space between the most image side lens surface of the first lens group and the most object side lens surface of the second lens group in the telephoto end state, and ft denotes the focal length of the zoom lens system in the telephoto end state. In one preferred zoom lens system of the one aspect of the present invention, the following conditional expression (2) is preferably satisfied: 0.8<(1−βA)×βB<3.5 (2) where βA denotes the lateral magnification of the shift lens group and βB denotes the lateral magnification of the optical elements locating between the shift lens group and an image plane. In one preferred zoom lens system of the one aspect of the present invention, the third lens group consists of, in order from the object, a third A lens group having positive refractive power, a third B lens group having positive refractive power, and a third C lens group having negative refractive power. The shift lens group having positive refractive power is the third B lens group. In one preferred zoom lens system of the one aspect of the present invention, the shift lens group includes at least one aspherical surface. In one preferred zoom lens system of the one aspect of the present invention, the second lens group includes at least three negative lenses and one positive lens. In one preferred zoom lens system of the one aspect of the present invention, the third A lens group consists of two positive lenses and one negative lens. In one preferred zoom lens system of the one aspect of the present invention, the third B lens group consists of one positive lens and one negative lens. In one preferred zoom lens system of the one aspect of the present invention, the fourth lens group includes at least one aspherical surface having a shape that positive refractive power becomes weak from the center to the periphery of the lens surface. According to another aspect of the present invention, a zoom lens system includes, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power. At least the first lens group and the fourth lens group move to the object side such that when the state of lens group positions varies from a wide-angle end state to a telephoto end state a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group decreases. The third lens group includes a first sub-lens group, a second sub-lens group, and a third sub-lens group. The second sub-lens group is arranged to the image side of the first sub-lens group with an air space. The third sub-lens group is arranged to the image side of the second sub-lens group with an air space. An image is shifted by moving the second sub-lens groups shifting substantially perpendicularly to the optical axis. An aperture stop is arranged in the vicinity of the third lens group including inside of the third lens group. The following conditional expressions (3) and (4) are satisfied: 0.05<Ds/fw<0.7 (3) 0.1<ft/fA<1.5 (4) where Ds denotes a distance along the optical axis between the aperture stop and the nearest lens surface of the second sub-lens group, fw denotes the focal length of the zoom lens system in the wide-angle end state, fA denotes the focal length of the whole lenses locating to the object side of the second sub-lens group in the telephoto end state, and ft denotes the focal length of the zoom lens system in the telephoto end state. In one preferred zoom lens system of the another aspect of the present invention, the first sub-lens group has positive refractive power and the following conditional expression (5) is preferably satisfied: 0.06<fa/ft<0.2 (5) where fa denotes the focal length of the first sub-lens group. In one preferred zoom lens system of the another aspect of the present invention, the second sub-lens group includes at least one positive lens and one negative lens, and has positive refractive power. The following conditional expression (6) is preferably satisfied: −0.6<(na/ra)/(nb/rb)<0 (6) where ra denotes a radius of curvature of the most object side lens surface of the second sub-lens group, na denotes refractive index at d-line of the most object side lens of the second sub-lens group, rb denotes a radius of curvature of the most image side lens surface of the second sub-lens group, and nb denotes refractive index at d-line of the most image side lens of the second sub-lens group. In one preferred zoom lens system of the another aspect of the present invention, the third sub-lens group has negative refractive power and the following conditional expression (7) is preferably satisfied: 0.5<|fc|/f3<0.9 (7) where fc denotes the focal length of the third sub-lens group, and f3 denotes the focal length of the third lens group. In one preferred zoom lens system of the another aspect of the present invention, the third sub-lens group includes a negative lens having a concave surface facing to the object locating to the most object side and the following conditional expression (8) is preferably satisfied: 0.5<|rc|/f3<0.75 (8) where rc denotes a radius of curvature of the negative lens locating to the most object side of the third sub-lens group. Other feature and advantages according to the present invention will be readily understood from the detailed description of the preferred embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a sectional view of a zoom lens system according to Example 1 of a first embodiment of the present invention. FIGS. 2A and 2B graphically show various aberrations of the zoom lens system according to Example 1 in a wide-angle end state in which FIG. 2A shows various aberrations without vibration reduction correction, and FIG. 2B shows coma with vibration reduction correction. FIGS. 3A and 3B graphically show various aberrations of the zoom lens system according to Example 1 in an intermediate focal length state in which FIG. 3A shows various aberrations without vibration reduction correction, and FIG. 3B shows coma with vibration reduction correction. FIGS. 4A and 4B graphically show various aberrations of the zoom lens system according to Example 1 in a telephoto end state in which FIG. 4A shows various aberrations without vibration reduction correction, and FIG. 4B shows coma with vibration reduction correction. FIG. 5 is a diagram showing a sectional view of a zoom lens system according to Example 2 of the first embodiment of the present invention. FIGS. 6A and 6B graphically show various aberrations of the zoom lens system according to Example 2 in a wide-angle end state in which FIG. 6A shows various aberrations without vibration reduction correction, and FIG. 6B shows coma with vibration reduction correction. FIGS. 7A and 7B graphically show various aberrations of the zoom lens system according to Example 2 in an intermediate focal length state in which FIG. 7A shows various aberrations without vibration reduction correction, and FIG. 7B shows coma with vibration reduction correction. FIGS. 8A and 8B graphically show various aberrations of the zoom lens system according to Example 2 in a telephoto end state in which FIG. 8A shows various aberrations without vibration reduction correction, and FIG. 8B shows coma with vibration reduction correction. FIG. 9 is a diagram showing a sectional view of a zoom lens system according to Example 3 of the first embodiment of the present invention. FIGS. 10A and 10B graphically show various aberrations of the zoom lens system according to Example 3 in a wide-angle end state in which FIG. 11A shows various aberrations without vibration reduction correction, and FIG. 10B shows coma with vibration reduction correction. FIGS. 11A and 11B graphically show various aberrations of the zoom lens system according to Example 3 in an intermediate focal length state in which FIG. 11A shows various aberrations without vibration reduction correction, and FIG. 11B shows coma with vibration reduction correction. FIGS. 12A and 12B graphically show various aberrations of the zoom lens system according to Example 3 in a telephoto end state in which FIG. 12A shows various aberrations without vibration reduction correction, and FIG. 12B shows coma with vibration reduction correction. FIG. 13 is a diagram showing a sectional view of a zoom lens system according to Example 4 of the first embodiment of the present invention. FIGS. 14A and 14B graphically show various aberrations of the zoom lens system according to Example 4 in a wide-angle end state in which FIG. 14A shows various aberrations without vibration reduction correction, and FIG. 14B shows coma with vibration reduction correction. FIGS. 15A and 15B graphically show various aberrations of the zoom lens system according to Example 4 in an intermediate focal length state in which FIG. 15A shows various aberrations without vibration reduction correction, and FIG. 15B shows coma with vibration reduction correction. FIGS. 16A and 16B graphically show various aberrations of the zoom lens system according to Example 4 in a telephoto end state in which FIG. 16A shows various aberrations without vibration reduction correction, and FIG. 16B shows coma with vibration reduction correction. FIG. 17 is a diagram showing a sectional view of a zoom lens system according to Example 5 of the first embodiment of the present invention. FIGS. 18A and 18B graphically show various aberrations of the zoom lens system according to Example 5 in a wide-angle end state in which FIG. 18A shows various aberrations without vibration reduction correction, and FIG. 18B shows coma with vibration reduction correction. FIGS. 19A and 19B graphically show various aberrations of the zoom lens system according to Example 5 in an intermediate focal length state in which FIG. 19A shows various aberrations without vibration reduction correction, and FIG. 19B shows coma with vibration reduction correction. FIGS. 20A and 20B graphically show various aberrations of the zoom lens system according to Example 5 in a telephoto end state in which FIG. 20A shows various aberrations without vibration reduction correction, and FIG. 20B shows coma with vibration reduction correction. FIG. 21 is a diagram showing a sectional view of a zoom lens system according to Example 6 of the first embodiment of the present invention. FIGS. 22A and 22B graphically show various aberrations of the zoom lens system according to Example 6 in a wide-angle end state in which FIG. 22A shows various aberrations without vibration reduction correction, and FIG. 22B shows coma with vibration reduction correction. FIGS. 23A and 23B graphically show various aberrations of the zoom lens system according to Example 6 in an intermediate focal length state in which FIG. 23A shows various aberrations without vibration reduction correction, and FIG. 23B shows coma with vibration reduction correction. FIGS. 24A and 24B graphically show various aberrations of the zoom lens system according to Example 6 in a telephoto end state in which FIG. 24A shows various aberrations without vibration reduction correction, and FIG. 24B shows coma with vibration reduction correction. FIG. 25 is a diagram showing power arrangement of a zoom lens system according to each Example of a second embodiment of the present invention. FIG. 26 is a diagram showing the lens arrangement of a zoom lens system according to Example 7 of a second embodiment of the present invention. FIGS. 27A, 27B, and 27C graphically show various aberrations of the zoom lens system according to Example 7 focusing at infinity in a wide-angle end state (f=28.80), an intermediate focal length state (f=100.00), and a telephoto end state (f=291.00), respectively. FIGS. 28A, 28B, and 28C graphically show coma of the zoom lens system according to Example 7 focusing at infinity in a wide-angle end state (f=28.80), an intermediate focal length state (f=100.00), and a telephoto end state (f=291.00), respectively, when a second sub-lens group is shifted. FIG. 29 is a diagram showing the lens arrangement of a zoom lens system according to Example 8 of the second embodiment of the present invention. FIGS. 30A, 30B, and 30C graphically show various aberrations of the zoom lens system according to Example 8 focusing at infinity in a wide-angle end state (f=28.80), an intermediate focal length state (f=100.00), and a telephoto end state (f=290.99), respectively. FIGS. 31A, 31B, and 31C graphically show coma of the zoom lens system according to Example 8 focusing at infinity in a wide-angle end state (f=28.80), an intermediate focal length state (f=100.00), and a telephoto end state (f=290.99), respectively, when a second sub-lens group is shifted. FIG. 32 is a diagram showing the lens arrangement of a zoom lens system according to Example 9 of the second embodiment of the present invention. FIGS. 33A, 33B, and 33C graphically show various aberrations of the zoom lens system according to Example 9 focusing at infinity in a wide-angle end state (f=28.80), an intermediate focal length state (f=100.00), and a telephoto end state (f=291.00), respectively. FIGS. 34A, 34B, and 34C graphically show coma of the zoom lens system according to Example 9 focusing at infinity in a wide-angle end state (f=28.80), an intermediate focal length state (f=100.00), and a telephoto end state (f=291.00), respectively, when a second sub-lens group is shifted. DESCRIPTION OF THE PREFERRED EMBODIMENTS Basic construction of the high zoom ratio zoom lens system capable of shifting an image (hereinafter called a zoom lens system) according to the present invention is going to be explained below. [First Embodiment] A zoom lens system according to a first embodiment of the present invention includes, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power. When the state of lens group positions varies from a wide-angle end state to a telephoto end state, the first lens group through the fourth lens group move such that a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group decreases. The third lens group includes at least two sub-lens groups having positive refractive power. The zoom lens system carries out vibration reduction correction by shifting an image by means of moving either sub-lens group of the two sub-lens groups as a shift lens group perpendicularly to the optical axis. The following conditional expression (1) is satisfied: 0.120<DT/ft<0.245 (1) where DT denotes an air space between the most image side lens surface of the first lens group and the most object side lens surface of the second lens group in the telephoto end state, and ft denotes the focal length of the zoom lens system in the telephoto end state. In the third lens group having positive refractive power, when either sub-lens group of the two sub-lens groups having positive refractive power is used as a shift lens group, variation in aberrations upon shifting can be small since small refractive power affects aberrations little. When a vibration reduction correction is carried out by using a lens group having negative refractive power as a shift lens group, the shift lens group has to be moved in the same direction of the camera shake, so that the burden on the controller becomes heavier and vibration upon correcting camera shake becomes larger causing discomfort to a photographer in comparison with a vibration reduction correction using the positive sub-lens group as a shift lens group. Accordingly, it is desirable to select a sub-lens group having positive refractive power as a shift lens group. Conditional expression (1) defines an appropriate range of an air space between the first lens group and the second lens group in the telephoto end state. When the ratio DT/ft is equal to or falls below the lower limit of conditional expression (1), negative spherical aberration in the telephoto end state cannot be corrected well and a high zoom ratio cannot be accomplished, so it is undesirable. When the lower limit is set to 0.15 or more, various aberrations such as spherical aberration can further be corrected, so that it is desirable. On the other hand, when the ratio DT/ft is equal to or exceeds the upper limit of conditional expression (1), the off-axis ray passing through the first lens group leaves away from the optical axis in the telephoto end state, so the diameter of the first lens group becomes large. It is undesirable. When the upper limit is set to 0.240 or less, various aberrations such as spherical aberration can further be corrected, so that it is desirable. In a zoom lens system according to the first embodiment of the present invention, in order to obtain better optical performance, it is desirable to satisfy the following conditional expression (2): 0.8<(1−βA)×B<3.5 (2) where βA denotes the lateral magnification of the shift lens group and βB denotes the lateral magnification of the optical elements locating between the shift lens group and the image plane. Conditional expression (2) relates to the lateral magnification of the shift lens group and that of the optical elements locating between the shift lens group and the image plane. When the ratio (1−βA)×βB is equal to or falls below the lower limit of conditional expression (2), the decentering amount of the shift lens group for obtaining sufficient amount of the image shift becomes large, so that the diameter of the shift lens group becomes large causing increase in the weight. As a result, a driver for the shift lens group becomes large and compactness is damaged, so that it is undesirable. On the other hand, when the ratio (1−βA)×βB is equal to or exceeds the upper limit of conditional expression (2), the image moves largely in accordance with a minute variation in the shift lens group, so that it becomes difficult to control and drive the shift lens group upon correcting camera shake. It is undesirable. When the upper limit is set to 3.0 or less, it becomes easy to control and drive the shift lens group obtaining good optical performance, so that it is preferable. In a zoom lens system according to the first embodiment of the present invention, it is preferable that the third lens group is composed of, in order from the object, a third A lens group having positive refractive power, a third B lens group having positive refractive power, and a third C lens group having negative refractive power, and the third B lens group is the shift lens group. Accordingly, the shift lens group can be compact and lightweight, so that it becomes possible to obtain a compact, high zoom ratio optical system without sacrificing good optical performance. In a zoom lens system according to the first embodiment of the present invention, it is desirable that the shift lens group has at least one aspherical surface. Now, it becomes possible to obtain good optical performance upon shifting the image. In a zoom lens system according to the first embodiment of the present invention, it is preferable that the second lens group includes at least three negative lenses and a positive lens, the third A lens group includes two positive lenses and a negative lens, the third B lens group consists of a positive lens and a negative lens, and the fourth lens group has at least one aspherical surface having a shape that positive refractive power becomes strong from the center to the periphery of the lens surface. Accordingly, it becomes possible to obtain a compact zoom lens system having optical performance. In a zoom lens system according to the first embodiment of the present invention, although focusing is carried out by the second lens group, any lens group other than the second lens group can be used for focusing. Although the aperture stop is arranged between the second lens group and the third lens group, it may be arranged in other space such as the space between the third lens group and the fourth lens group, or a space in a lens group such as a space in the third lens group. Although a zoom lens system according to the first embodiment of the present invention is composed of four lens groups, any other lens group can be added between each lens group or adjacent to the object or image side of the lens system. In a zoom lens system according to the first embodiment of the present invention, a diffractive optical element can be used from other point of view. By using a diffractive optical element chromatic aberration can be corrected well. Each zoom lens system according to each example of the first embodiment is explained below. In a zoom lens system according to each Example of the present invention, an aspherical surface is expressed by the following expression; x=cy2/[1+(1−κc2y2)1/2]+C4·y4+C6·y6+C8·y8+C10·y10 where y denotes a height from the optical axis, x denotes a sag amount, c denotes a radius of curvature of a reference sphere (a paraxial radius of curvature), κ denotes a conical coefficient, C4, C6, C8, and C10 denote 4th, 6th, 8th, and 10th order aspherical coefficient, respectively. EXAMPLE 1 FIG. 1 is a diagram showing a sectional view of a zoom lens system according to Example 1 of the first embodiment of the present invention. In FIG. 1, the zoom lens system is composed of, in order from an object, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, and a fourth lens group G4 having positive refractive power. When the state of lens group positions varies from a wide-angle end state to a telephoto end state, the first lens group G1 through the fourth lens group G4 move such that a distance between the first lens group G1 and the second lens group G2 increases, a distance between the second lens group G2 and the third lens group G3 decreases, and a distance between the third lens group G3 and the fourth lens group G4 decreases. The reference symbol I denotes the image plane. The third lens group G3 is composed of, in order from the object, a third A lens group 3A having positive refractive power, a third B lens group 3B having positive refractive power, and a third C lens group 3C having negative refractive power. The image can be shifted by moving the third B lens group 3B as a shift lens group perpendicularly to the optical axis. The first lens group G1 is composed of a cemented lens constructed by a negative meniscus lens L11 having a convex surface facing to the object cemented with a double convex positive lens L12 and a positive meniscus lens L13 having a convex surface facing to the object. The second lens group G2 is composed of a negative meniscus lens L21 having a convex surface facing to the object, a double concave negative lens L22, a double convex positive lens L23, and a double concave negative lens L24. The third A lens group 3A is composed of a double convex positive lens L31, and a cemented lens constructed by a positive meniscus lens L32 having a convex surface facing to the object and a negative meniscus lens L33 having a convex surface facing to the object. The third B lens group 3B is composed of a cemented lens constructed by a double convex positive lens L34 and a negative meniscus lens L35 having a concave surface facing to the object. The third C lens group 3C is composed of a negative meniscus lens L36 having a concave surface facing to the object. The fourth lens group G4 is composed of a double convex positive lens L41, and a cemented lens constructed by a positive meniscus lens L42 having a concave surface facing to the object and a double concave negative lens L43. The aperture stop S is arranged in the vicinity of the most object side lens surface of the third lens group G3 and moved together with the third lens group G3 upon zooming. Various values of a zoom lens system according to Example 1 are shown below in Table 1. In [Specifications], f denotes the focal length, FNO denotes an f-number, 2ω denotes an angle of view, and BF denotes the back focal length. In [Lens Data], the left most column shows the surface number that is a lens surface counted in order from the object, r denotes the radius of curvature of a lens, d denotes a distance along the optical axis between the lens surfaces, ν denotes Abbe number of the medium between the lens surfaces, and n denote refractive index of a medium between the lens surfaces at d-line (λ=587.56 nm). In the tables for various values, “mm” is generally used for the unit of length such as the focal length, the radius of curvature, and the separation between optical surfaces. However, since an optical system proportionally enlarged or reduced its dimension can be obtained similar optical performance, the unit is not necessary to be limited to “mm” and any other suitable unit can be used. In [Aspherical Data], “E−n” denotes “10−n”. The explanation of reference symbols is the same in the other examples. TABLE 1 [Specifications] Wide-angle Intermediate Telephoto f = 31.169 112.180 299.993 mm 2ω = 72.3 21.0 8.0° FNO = 3.6 5.6 6.6 [Lens Data] Surface Number r d ν n 1 128.0762 2.000 28.56 1.79504 2 74.7110 8.000 82.52 1.49782 3 −301.4490 0.100 4 62.5606 5.200 82.52 1.49782 5 174.0263 D1 6 133.1122 0.200 38.09 1.55389 7 110.0000 1.000 49.61 1.77250 8 18.5937 4.800 9 −68.9214 1.000 42.72 1.83481 10 80.9399 0.100 11 31.2602 4.200 22.76 1.80809 12 −61.8236 1.200 13 −26.3434 1.000 49.61 1.77250 14 302.0857 D2 15 0.0000 0.500 (Aperture Stop S) 16 32.0000 3.500 54.66 1.72916 17 −631.6375 0.100 18 21.1207 4.000 82.52 1.49782 19 248.3602 1.000 37.17 1.83400 20 28.9425 3.000 21 49.5392 3.000 49.52 1.74442 22 −39.8231 1.000 23.78 1.84666 23 −121.9266 3.000 24 −26.5552 1.000 42.72 1.83481 25 −220.0557 D3 26 53.1534 4.000 55.34 1.67790 27 −20.4060 0.100 28 −117.6204 4.000 33.80 1.64769 29 −14.2583 1.000 42.72 1.83481 30 71.3854 BF [Aspherical Data] Surface Number 6 κ = 64.5192 C4 = 7.6611E−07 C6 = 1.7093E−09 C8 = −2.1081E−11 C10 = 1.0148E−13 Surface Number 21 κ = −1.0025 C4 = −5.4592E−07 C6 = −3.9750E−09 C8 = 2.0368E−11 C10 = 1.8147E−13 Surface Number 26 κ= −19.8163 C4 = 1.9335E−07 C6 = −2.0631E−08 C8 = 1.4059E−10 C10 = 0.0000E−00 Surface Number 27 κ = 0.3829 C4 = 6.9273E−06 C6 = −1.0557−08 C8 = 1.5108E−10 C10 = 3.9880E−13 [Variable Intervals] Wide-angle Intermediate Telephoto f = 31.169 112.180 299.993 D1 = 1.692 38.508 62.092 D2 = 27.147 12.174 1.502 D3 = 4.956 0.910 0.033 BF = 46.216 82.184 100.098 [Various Values upon Shifting] Wide-angle Intermediate Telephoto f = 31.169 112.180 299.993 Lens Shift 0.250 0.350 0.450 Image Shift 0.295 0.673 1.041 [Values for Conditional Expressions] (1) DT/ft = 0.207 (2) ( 1 - βA ) × βB = 1.2 ( Wide - angle end state ) = 1.9 ( Intermediate focal length state ) = 2.3 ( Telephoto end state ) FIGS. 2A, 2B through 4A, 4B are graphs showing various aberrations of the zoom lens system according to Example 1 of the first embodiment of the present invention focusing at infinity at d-line (λ=587.6 nm). FIGS. 2A and 2B graphically show various aberrations in a wide-angle end state (f=31.2) in which FIG. 2A shows various aberrations without vibration reduction correction, and FIG. 2B shows coma with vibration reduction correction. FIGS. 3A and 3B graphically show various aberrations in an intermediate focal length state (f=112.2) in which FIG. 3A shows various aberrations without vibration reduction correction, and FIG. 3B shows coma with vibration reduction correction. FIGS. 4A and 4B graphically show various aberrations in a telephoto end state (f=300.0) in which FIG. 4A shows various aberrations without vibration reduction correction, and FIG. 4B shows coma with vibration reduction correction. In respective graphs, FNO denotes the f-number, and A denotes a half angle of view (unit: degree). In the graph showing spherical aberration, f-number shows the value at the maximum aperture. In the graphs showing astigmatism and distortion, the maximum value of a half angle of view A is shown. In the graph showing coma, a half angle of view A is shown. In the graph showing astigmatism, a solid line indicates a sagittal image plane and a broken line indicates a meridional plane. The above-described explanation regarding various aberration graphs is the same as the other examples. As is apparent from the respective graphs, the zoom lens system according to Example 1 shows superb optical performance as a result of good corrections to various aberrations in each focal length state (the wide-angle end state, the intermediate focal length state, and the telephoto end state). EXAMPLE 2 FIG. 5 is a diagram showing a sectional view of a zoom lens system according to Example 2 of the first embodiment of the present invention. In FIG. 5, the zoom lens system is composed of, in order from an object, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, and a fourth lens group G4 having positive refractive power. When the state of lens group positions varies from a wide-angle end state to a telephoto end state, the first lens group G1 through the fourth lens group G4 move such that a distance between the first lens group G1 and the second lens group G2 increases, a distance between the second lens group G2 and the third lens group G3 decreases, and a distance between the third lens group G3 and the fourth lens group G4 decreases. The reference symbol I denotes the image plane. The third lens group G3 is composed of, in order from the object, a third A lens group 3A having positive refractive power, a third B lens group 3B having positive refractive power, and a third C lens group 3C having negative refractive power. The image can be shifted by moving the third B lens group 3B as a shift lens group perpendicularly to the optical axis. The first lens group G1 is composed of a cemented lens constructed by a negative meniscus lens L11 having a convex surface facing to the object cemented with a double convex positive lens L12 and a positive meniscus lens L13 having a convex surface facing to the object. The second lens group G2 is composed of a negative meniscus lens L21 having a convex surface facing to the object, a double concave negative lens L22, a double convex positive lens L23, and a double concave negative lens L24. The third A lens group 3A is composed of a double convex positive lens L31, and a cemented lens constructed by a double convex positive lens L32 and a double concave negative lens L33. The third B lens group 3B is composed of a cemented lens constructed by a double convex positive lens L34 and a negative meniscus lens L35 having a concave surface facing to the object. The third C lens group 3C is composed of a double concave negative lens L36. The fourth lens group G4 is composed of a double convex positive lens L41, and a cemented lens constructed by a positive meniscus lens L42 having a concave surface facing to the object and a double concave negative lens L43. The aperture stop S is arranged in the vicinity of the most object side lens surface of the third lens group G3 and moved together with the third lens group G3 upon zooming. Various values of a zoom lens system according to Example 2 are shown below in Table 2. TABLE 2 [Specifications] Wide-angle Intermediate Telephoto f = 29.207 115.150 349.995 mm 2ω = 75.8 20.5 6.9° FNO = 3.6 6.0 6.7 [Lens Data] Surface Number r d ν n 1 95.2158 2.000 28.56 1.79504 2 62.6157 8.200 82.52 1.49782 3 −924.0888 0.100 4 73.6118 5.000 82.52 1.49782 5 303.8324 D1 6 119.3054 0.200 38.09 1.55389 7 100.0000 1.200 49.61 1.77250 18 18.8047 6.417 19 −48.2046 1.000 42.72 1.83481 10 65.6505 0.100 11 34.8008 4.800 22.76 1.80809 12 −44.4934 1.000 13 −24.5572 1.000 49.61 1.77250 14 1817.3930 D2 15 0.0000 0.500 (Aperture Stop S) 16 27.1464 4.500 55.52 1.69680 17 −150.2724 0.100 18 26.8350 5.000 82.52 1.49782 19 −46.9911 1.000 37.17 1.83400 20 38.4531 3.000 21 45.1473 3.800 49.52 1.74442 22 −68.3823 1.000 23.78 1.84666 23 −181.6270 2.000 24 −36.5030 1.000 42.72 1.83481 25 357.3702 D3 26 60.3036 4.200 55.52 1.69680 27 −24.3217 0.100 28 −83.5169 5.500 33.80 1.64769 29 −13.7618 1.000 42.72 1.83481 30 144.8077 BF [Aspherical Data] Surface Number 6 κ = 40.8477 C4 = 8.7927E−07 C6 = −1.6679E−09 C8 = −7.6432E−12 C10 = 1.0148E−13 Surface Number 21 κ = 0.3574 C4 = −3.3903E−06 C6 = 9.1445E−09 C8 = −2.4850E−11 C10 = −0.0000E−00 Surface Number 26 κ = −0.5113 C4 = −8.1127E−06 C6 = −3.1018E−08 C8 = 1.8406E−10 C10 = 0.0000E−00 Surface Number 27 κ = 2.0550 C4 = 2.1909E−05 C6 = −1.2389E−08 C8 = 2.0864E−10 C10 = 0.000E−00 [Variable Intervals] Wide-angle Intermediate Telephoto f = 29.207 115.150 349.995 D1 = 1.400 38.416 62.500 D2 = 27.734 12.761 2.089 D3 = 5.892 1.846 0.970 BF = 43.781 86.842 112.269 [Various Values upon Shifting] Wide-angle Intermediate Telephoto f = 29.207 115.150 349.995 Lens Shift 0.250 0.350 0.450 Image Shift 0.296 0.724 1.178 [Values for Conditional Expressions] (1) DT/ft = 0.179 (2) ( 1 - βA ) × βB = 1.2 ( Wide - angle end state ) = 2.1 ( Intermediate focal length state ) = 2.6 ( Telephoto end state ) FIGS. 6A, 6B through 8A, 8B are graphs showing various aberrations of the zoom lens system according to Example 2 of the first embodiment of the present invention focusing at infinity at d-line (λ=587.6 nm). FIGS. 6A and 6B graphically show various aberrations in a wide-angle end state (f=29.2) in which FIG. 6A shows various aberrations without vibration reduction correction, and FIG. 6B shows coma with vibration reduction correction. FIGS. 7A and 7B graphically show various aberrations in an intermediate focal length state (f=115.2) in which FIG. 7A shows various aberrations without vibration reduction correction, and FIG. 7B shows coma with vibration reduction correction. FIGS. 8A and 8B graphically show various aberrations in a telephoto end state (f=350.0) in which FIG. 8A shows various aberrations without vibration reduction correction, and FIG. 8B shows coma with vibration reduction correction. As is apparent from the respective graphs, the zoom lens system according to Example 2 shows superb optical performance as a result of good corrections to various aberrations in each focal length state (the wide-angle end state, the intermediate focal length state, and the telephoto end state). EXAMPLE 3 FIG. 9 is a diagram showing a sectional view of a zoom lens system according to Example 3 of the first embodiment of the present invention. In FIG. 9, the zoom lens system is composed of, in order from an object, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, and a fourth lens group G4 having positive refractive power. When the state of lens group positions varies from a wide-angle end state to a telephoto end state, the first lens group G1 through the fourth lens group G4 move such that a distance between the first lens group G1 and the second lens group G2 increases, a distance between the second lens group G2 and the third lens group G3 decreases, and a distance between the third lens group G3 and the fourth lens group G4 decreases. The reference symbol I denotes the image plane. The third lens group G3 is composed of, in order from the object, a third A lens group 3A having positive refractive power, a third B lens group 3B having positive refractive power, and a third C lens group 3C having negative refractive power. The image can be shifted by moving the third B lens group 3B as a shift lens group perpendicularly to the optical axis. The first lens group G1 is composed of a cemented lens constructed by a negative meniscus lens L11 having a convex surface facing to the object cemented with a double convex positive lens L12 and a positive meniscus lens L13 having a convex surface facing to the object. The second lens group G2 is composed of a negative meniscus lens L21 having a convex surface facing to the object, a double concave negative lens L22, a double convex positive lens L23, and a double concave negative lens L24. The third A lens group 3A is composed of a double convex positive lens L31, and a cemented lens constructed by a double convex positive lens L32 and a double concave negative lens L33. The third B lens group 3B is composed of a cemented lens constructed by a double convex positive lens L34 and a negative meniscus lens L35 having a concave surface facing to the object. The third C lens group 3C is composed of a double concave negative lens L36. The fourth lens group G4 is composed of a double convex positive lens L41, and a cemented lens constructed by a positive meniscus lens L42 having a concave surface facing to the object and a double concave negative lens L43. The aperture stop S is arranged in the vicinity of the most object side lens surface of the third lens group G3 and moved together with the third lens group G3 upon zooming. Various values of a zoom lens system according to Example 3 are shown below in Table 3. TABLE 3 [Specifications] Wide-angle Intermediate Telephoto f = 30.785 100.428 260.003 mm 2ω = 73.0 23.4 9.2° FNO = 3.6 5.2 6.2 [Lens Data] Surface Number r d ν n 1 113.0938 2.000 23.78 1.84666 2 77.8725 7.500 82.52 1.49782 3 −392.0046 0.100 4 63.1691 4.500 82.52 1.49782 5 144.9233 D1 6 187.1436 0.200 38.09 1.55389 7 160.7200 1.200 49.61 1.77250 8 19.5404 6.200 9 −57.2837 1.000 42.72 1.83481 10 89.0734 0.100 11 35.5271 4.500 23.78 1.84666 12 −48.5191 1.000 13 −27.5498 1.000 49.61 1.77250 14 274.0976 D2 15 0.0000 0.500 (Aperture Stop S) 16 30.0000 4.000 55.34 1.67790 17 −79.6551 0.100 18 21.4733 4.500 82.52 1.49782 19 −131.3788 1.000 37.17 1.83400 20 29.5229 2.500 21 46.6074 3.200 49.52 1.74442 22 −50.5322 1.000 23.78 1.84666 23 −178.5738 2.500 24 −27.8094 1.000 42.72 1.83481 25 143.2554 D3 26 87.3995 4.500 55.34 1.67790 27 −21.0343 0.200 28 −102.6584 5.000 34.47 1.63980 29 −14.3797 1.000 42.72 1.83481 30 459.5424 BF [Aspherical Data] Surface Number 6 κ = 1.0000 C4 = 3.4488E−06 C6 = 3.5836E−09 C8 = −1.8482E−11 C10 = 1.2823E−13 Surface Number 21 κ = 5.3475 C4 = 3.9544E−06 C6 = −2.1153E−09 C8 = 1.2308E−11 C10 = 1.8147E−13 Surface Number 26 κ = −18.7137 C4 = 9.3928E−06 C6 = 7.6348E−09 C8 = 1.4059E−10 C10 = 0.0000E−00 Surface Number 27 κ = 0.7025 C4 = 4.8101E−06 C6 = −1.1899E−08 C8 = 1.9145E−10 C10 = 3.9880E−13 [Variable Intervals] Wide-angle Intermediate Telephoto f = 30.785 100.428 260.003 D1 = 1.791 38.386 61.905 D2 = 28.018 13.045 2.372 D3 = 6.467 2.421 1.544 BF = 42.136 72.054 90.192 [Various Values upon Shifting] Wide-angle Intermediate Telephoto f = 30.785 100.428 260.003 Lens Shift 0.250 0.350 0.450 Image Shift 0.268 0.574 0.902 [Values for Conditional Expressions] (1) DT/ft = 0.238 (2) ( 1 - βA ) × βB = 1.1 ( Wide - angle end state ) = 1.9 ( Intermediate focal length state ) = 2.3 ( Telephoto end state ) FIGS. 10A, 10B through 12A, 12B are graphs showing various aberrations of the zoom lens system according to Example 3 of the first embodiment of the present invention focusing at infinity at d-line (λ=587.6 nm). FIGS. 10A and 10B graphically show various aberrations in a wide-angle end state (f=30.8) in which FIG. 10A shows various aberrations without vibration reduction correction, and FIG. 10B show coma with vibration reduction correction. FIGS. 11A and 11B graphically show various aberrations in an intermediate focal length state (f=100.4) in which FIG. 11A shows various aberrations without vibration reduction correction, and FIG. 11B shows coma with vibration reduction correction. FIGS. 12A and 12B graphically show various aberrations in a telephoto end state (f=260.0) in which FIG. 12A shows various aberrations without vibration reduction correction, and FIG. 12B shows coma with vibration reduction correction. As is apparent from the respective graphs, the zoom lens system according to Example 3 shows superb optical performance as a result of good corrections to various aberrations in each focal length state (the wide-angle end state, the intermediate focal length state, and the telephoto end state). EXAMPLE 4 FIG. 13 is a diagram showing a sectional view of a zoom lens system according to Example 4 of a first embodiment of the present invention. In FIG. 13, the zoom lens system is composed of, in order from an object, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, and a fourth lens group G4 having positive refractive power. When the state of lens group positions varies from a wide-angle end state to a telephoto end state, the first lens group G1 through the fourth lens group G4 move such that a distance between the first lens group G1 and the second lens group G2 increases, a distance between the second lens group G2 and the third lens group G3 decreases, and a distance between the third lens group G3 and the fourth lens group G4 decreases. The reference symbol I denotes the image plane. The third lens group G3 is composed of, in order from the object, a third A lens group 3A having positive refractive power, a third B lens group 3B having positive refractive power, and a third C lens group 3C having negative refractive power. The image can be shifted by moving the third B lens group 3B as a shift lens group perpendicularly to the optical axis. The first lens group G1 is composed of a cemented lens constructed by a negative meniscus lens L11 having a convex surface facing to the object cemented with a double convex positive lens L12 and a positive meniscus lens L13 having a convex surface facing to the object. The second lens group G2 is composed of a negative meniscus lens L21 having a convex surface facing to the object, a double concave negative lens L22, a double convex positive lens L23, and a double concave negative lens L24. The third A lens group 3A is composed of a double convex positive lens L31, and a cemented lens constructed by a double convex positive lens L32 and a double concave negative lens L33. The third B lens group 3B is composed of a cemented lens constructed by a double convex positive lens L34 and a negative meniscus lens L35 having a concave surface facing to the object. The third C lens group 3C is composed of a double concave negative lens L36. The fourth lens group G4 is composed of a double convex positive lens L41, and a cemented lens constructed by a positive meniscus lens L42 having a concave surface facing to the object and a double concave negative lens L43. The aperture stop S is arranged in the vicinity of the most object side lens surface of the third lens group G3 and moved together with the third lens group G3 upon zooming. Various values of a zoom lens system according to Example 4 are shown below in Table 4. TABLE 4 [Specifications] Wide-angle Intermediate Telephoto f = 29.000 105.000 283.000 mm 2ω = 76.0 22.4 8.3° FNO = 3.6 5.4 5.9 [Lens Data] Surface Number r d ν n 1 126.4186 2.000 32.35 1.85026 2 70.0034 8.500 82.52 1.49782 3 −481.5412 0.100 4 61.9364 6.300 82.52 1.49782 5 326.2642 D1 6 206.3466 0.200 38.09 1.55389 7 155.0000 1.200 49.61 1.77250 8 19.2055 6.400 9 −48.3934 1.000 42.72 1.83481 10 89.2606 0.100 11 36.1705 4.800 23.78 1.84666 12 −41.8254 1.000 13 −25.8295 1.000 49.61 1.77250 14 197.7146 D2 15 0.0000 0.500 (Aperture Stop S) 16 28.1052 4.500 55.34 1.67790 17 −110.1068 0.100 18 27.8213 5.000 82.52 1.49782 19 −58.2729 1.000 37.17 1.83400 20 41.8777 3.800 21 42.5913 3.800 49.16 1.74001 22 −57.2086 1.000 23.78 1.84666 23 −230.3293 2.700 24 −30.2739 1.000 42.7 21.83481 25 217.1532 D3 26 55.2978 5.800 54.6 11.67440 27 −24.3191 0.150 28 −82.9547 6.500 34.47 1.63980 29 −14.5022 1.000 42.72 1.83481 30 499.5854 BF [Aspherical Data] Surface Number 6 κ = 1.0000 C4 = 4.0183E−06 C6 = 4.0686E−09 C8 = −2.4754E−11 C10 = 1.50995−13 Surface Number 21 κ = 0.4310 C4 = 1.3165E−07 C6 = 4.2138E−09 C8 = 3.4757E−11 C10 = 1.0724E−13 Surface Number 26 κ = −12.7409 C4 = 9.5672E−07 C6 = −4.9808E−09 C8 = 1.4920E−10 C10 = 0.0000E−00 Surface Number 27 K = 0.1485 C4 = 5.5835E−06 C6 = 1.4084E−08 C8 = 2.1151E−10 C10 = 4.0383E−13 [Variable Intervals] Wide-angle Intermediate Telephoto f = 29.000 105.000 288.000 D1 = 1.813 16.856 61.926 D2 = 27.746 19.801 2.100 D3 = 5.887 3.883 0.965 BF = 39.504 54.503 89.559 [Various Values upon Shifting] Wide-angle Intermediate Telephoto f = 29.000 105.000 288.000 Lens Shift 0.250 0.350 0.450 Image Shift 0.277 0.632 0.960 [Values for Conditional Expressions] (1) DT/ft = 0.179 (2) ( 1 - βA ) × βB = 1.1 ( Wide - angle end state ) = 1.8 ( Intermediate focal length state ) = 2.1 ( Telephoto end state ) FIGS. 14A, 14B through 16A, 16BB are graphs showing various aberrations of the zoom lens system according to Example 4 of the first embodiment of the present invention focusing at infinity at d-line (λ=587.6 nm). FIGS. 14A and 14B graphically show various aberrations in a wide-angle end state (f=29.0) in which FIG. 14A shows various aberrations without vibration reduction correction, and FIG. 14B shows coma with vibration reduction correction. FIGS. 15A and 15B graphically show various aberrations in an intermediate focal length state (f=105.0) in which FIG. 15A shows various aberrations without vibration reduction correction, and FIG. 15B shows coma with vibration reduction correction. FIGS. 16A and 16B graphically show various aberrations in a telephoto end state (f=288.0) in which FIG. 16A shows various aberrations without vibration reduction correction, and FIG. 16B shows coma with vibration reduction correction. As is apparent from the respective graphs, the zoom lens system according to Example 4 shows superb optical performance as a result of good corrections to various aberrations in each focal length state (the wide-angle end state, the intermediate focal length state, and the telephoto end state). EXAMPLE 5 FIG. 17 is a diagram showing a sectional view of a zoom lens system according to Example 5 of the first embodiment of the present invention. In FIG. 17, the zoom lens system is composed of, in order from an object, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, and a fourth lens group G4 having positive refractive power. When the state of lens group positions varies from a wide-angle end state to a telephoto end state, the first lens group G1 through the fourth lens group G4 move such that a distance between the first lens group G1 and the second lens group G2 increases, a distance between the second lens group G2 and the third lens group G3 decreases, and a distance between the third lens group G3 and the fourth lens group G4 decreases. The reference symbol I denotes the image plane. The third lens group G3 is composed of, in order from the object, a third A lens group 3A having positive refractive power, a third B lens group 3B having positive refractive power, and a third C lens group 3C having negative refractive power. The image can be shifted by moving the third B lens group 3B as a shift lens group perpendicularly to the optical axis. The first lens group G1 is composed of a cemented lens constructed by a negative meniscus lens L11 having a convex surface facing to the object cemented with a double convex positive lens L12 and a positive meniscus lens L13 having a convex surface facing to the object. The second lens group G2 is composed of a negative meniscus lens L21 having a convex surface facing to the object, a double concave negative lens L22, a double convex positive lens L23, and a double concave negative lens L24. The third A lens group 3A is composed of a double convex positive lens L31, and a cemented lens constructed by a double convex positive lens L32 and a double concave negative lens L33. The third B lens group 3B is composed of a cemented lens constructed by a double convex positive lens L34 and a negative meniscus lens L35 having a concave surface facing to the object. The third C lens group 3C is composed of a double concave negative lens L36. The fourth lens group G4 is composed of a double convex positive lens L41, and a negative meniscus lens L42 having a concave surface facing to the object. The aperture stop S is arranged in the vicinity of the most object side lens surface of the third lens group G3 and moved together with the third lens group G3 upon zooming. Various values of a zoom lens system according to Example 5 are shown below in Table 5. TABLE 5 [Specifications] Wide-angle Intermediate Telephoto f = 28.743 99.628 289.713 mm 2ω = 77.0 23.7 8.3° FNO = 3.5 5.4 6.3 [Lens Data] Surface Number r d ν n 1 94.4674 1.900 23.78 1.84666 2 67.7698 7.500 81.61 1.49700 3 −529.7017 0.100 4 60.3188 4.800 81.61 1.49700 5 135.6483 D1 6 111.7769 0.200 38.09 1.55389 7 105.1950 1.150 49.61 1.77250 8 16.3778 5.800 9 −44.8931 1.000 46.63 1.81600 10 98.5517 0.100 11 32.0133 4.200 22.76 1.80809 12 −49.2124 1.100 13 −27.3224 0.900 42.72 1.83481 14 1744.7263 D2 15 0.0000 0.500 (Aperture Stop 5) 16 32.4669 4.500 64.14 1.51633 17 −42.3952 0.100 18 37.5370 5.000 81.61 1.49700 19 −27.2467 1.000 37.17 1.83400 20 159.3545 3.000 21 60.0000 3.500 58.54 1.65160 22 −27.9361 0.800 46.63 1.81600 23 −57.3368 4.200 24 −36.9720 0.800 54.66 1.72916 25 120.8635 D3 26 150.0000 4.500 55.18 1.66547 27 −39.3664 8.000 28 −40.0000 1.000 54.66 1.72916 29 62.5642 BF [Aspherical Data] Surface Number 6 κ = 6.0000 C4 = 2.1440E−06 C6 = 2.0424E−09 C8 = −5.7444E−11 C10 = 2.0549E−13 Surface Number 16 κ = 0.4048 C4 = 1.6192E−06 C6 = 8.8809E−09 C8 = 0.0000E−00 C10 = 0.0000E−00 Surface Number 21 κ = 0.1975 C4 = 1.2413E−07 C6 = 4.8313E−09 C8 = 0.0000E−00 C10 = 0.0000E−00 Surface Number 27 κ = 0.2523 C4 = 7.8933E−07 C6 = 4.3698E−09 C8 = 1.0465E−11 C10 = 0.0000E−00 Surface Number 28 κ = 1.5241 C4 = −6.4146E−06 C6 = −1.2538E−08 C8 = 3.8377E−13 C10 = 0.0000E−00 [Variable Intervals] Wide-angle Intermediate Telephoto F = 28.743 99.628 289.713 D1 = 2.160 36.094 61.516 D2 = 25.560 10.629 0.005 D3 = 11.051 3.584 2.629 BF = 37.502 75.686 91.283 [Various Values upon Shifting] Wide-angle Intermediate Telephoto F = 28.743 99.628 289.713 Lens Shift 0.250 0.350 0.450 Image Shift 0.287 0.643 0.966 [Values for Conditional Expressions] (1) DT/ft = 0.212 (2) ( 1 - βA ) × βB = 1.1 ( Wide - angle end state ) = 1.8 ( Intermediate focal length state ) = 2.1 ( Telephoto end state ) FIGS. 18A, 18B through 20A, 20B are graphs showing various aberrations of the zoom lens system according to Example 5 of the first embodiment of the present invention focusing at infinity at d-line (λ=587.6 nm). FIGS. 18A and 18B graphically show various aberrations in a wide-angle end state (f=28.7) in which FIG. 18A shows various aberrations without vibration reduction correction, and FIG. 18B shows coma with vibration reduction correction. FIGS. 19A and 19B graphically show various aberrations in an intermediate focal length state (f=99.6) in which FIG. 19A shows various aberrations without vibration reduction correction, and FIG. 19B shows coma with vibration reduction correction. FIGS. 20A and 20B graphically show various aberrations in a telephoto end state (f=289.7) in which FIG. 20A shows various aberrations without vibration reduction correction, and FIG. 20B shows coma with vibration reduction correction. As is apparent from the respective graphs, the zoom lens system according to Example 5 shows superb optical performance as a result of good corrections to various aberrations in each focal length state (the wide-angle end state, the intermediate focal length state, and the telephoto end state). EXAMPLE 6 FIG. 21 is a diagram showing a sectional view of a zoom lens system according to Example 6 of a first embodiment of the present invention. In FIG. 21, the zoom lens system is composed of, in order from an object, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, and a fourth lens group G4 having positive refractive power. When the state of lens group positions varies from a wide-angle end state to a telephoto end state, the first lens group G1 through the fourth lens group G4 move such that a distance between the first lens group G1 and the second lens group G2 increases, a distance between the second lens group G2 and the third lens group G3 decreases, and a distance between the third lens group G3 and the fourth lens group G4 decreases. The reference symbol I denotes the image plane. The third lens group G3 is composed of, in order from the object, a third A lens group 3A having positive refractive power, a third B lens group 3B having positive refractive power, and a third C lens group 3C having negative refractive power. The image can be shifted by moving the third B lens group 3B as a shift lens group perpendicularly to the optical axis. The first lens group G1 is composed of a cemented lens constructed by a negative meniscus lens L11 having a convex surface facing to the object cemented with a double convex positive lens L12 and a positive meniscus lens L13 having a convex surface facing to the object. The second lens group G2 is composed of a negative meniscus lens L21 having a convex surface facing to the object, a double concave negative lens L22, a double convex positive lens L23, and a negative meniscus lens L24 having a concave surface facing to the object. The third A lens group 3A is composed of a double convex positive lens L31, a positive meniscus lens L32 having a convex surface facing to the object, and a double concave negative lens L33. The third B lens group 3B is composed of a cemented lens constructed by a double convex positive lens L34 and a negative meniscus lens L35 having a concave surface facing to the object. The third C lens group 3C is composed of a negative meniscus lens L36 having a concave surface facing to the object. The fourth lens group G4 is composed of a double convex positive lens L41, and a cemented lens constructed by a positive meniscus lens L42 having a concave surface facing to the object and a negative meniscus lens L43 having a concave surface facing to the object. The aperture stop S is arranged in the vicinity of the most object side lens surface of the third lens group G3 and moved together with the third lens group G3 upon zooming. Various values of a zoom lens system according to Example 6 are shown below in Table 6. TABLE 6 [Specifications] Wide-angle Intermediate Telephoto f = 28.800 100.001 287.999 mm 2ω = 77.0 23.7 8.32° FNO = 3.6 5.5 5.8 [Lens Data] Surface Number r d ν n 1 115.6310 1.800 28.56 1.79504 2 71.8788 7.200 81.61 1.49700 3 −555.2835 0.100 4 65.0392 5.500 81.61 1.49700 5 232.0570 D1 6 512.2381 0.100 38.09 1.55389 7 180.0000 1.200 53.85 1.71300 8 18.5968 6.500 9 −50.4004 1.000 42.72 1.83481 10 63.9703 0.100 11 39.9492 4.600 23.78 1.84666 12 −50.7514 1.500 13 −25.9825 0.900 49.61 1.77250 14 −100.6446 D2 15 0.0000 0.500 (Aperture Stop S) 16 22.7861 6.000 81.61 1.49700 17 −76.8308 0.100 18 27.0706 4.000 90.30 1.45600 19 304.3279 2.350 20 −54.3445 0.800 40.77 1.88300 21 95.0234 3.150 22 33.1566 4.500 61.18 1.58913 23 −72.2937 0.800 23.78 1.84666 24 −194.8570 6.700 25 −22.3588 0.800 37.17 1.83400 26 −167.7429 D3 27 730.6059 2.800 49.32 1.74320 28 −40.4002 0.100 29 −120.1675 7.400 36.26 1.62004 30 −16.1891 1.000 46.63 1.81600 31 −45.2280 BF [Aspherical Data] Surface Number 6 κ = 1.0000 C4 = 5.68685−06 C6 = 6.5389E−09 C8 = −6.8904E−11 C10 = 1.5909E−13 Surface Number 22 κ = 1.0000 C4 = 5.2152E−06 C6 = 1.22385−08 C8 = 6.5604E−11 C10 = −4.46465−13 Surface Number 28 κ = 1.0000 C4 = 1.41055−05 C6 = 3.3242E−08 C8 = −8.46795−11 C10 = 3.5821E−13 [Variable Intervals] Wide-angle Intermediate Telephoto F = 28.800 100.001 287.999 D1 = 1.528 32.944 62.211 D2 = 33.290 14.442 2.102 D3 = 4.508 1.422 0.946 BF = 38.606 82.076 93.134 [Various Values upon Shifting] Wide-angle Intermediate Telephoto F = 28.800 100.001 287.999 Lens Shift 0.250 0.350 0.450 Image Shift 0.272 0.652 0.934 [Values for Conditional Expressions] (1) DT/ft = 0.216 (2) ( 1 - βA ) × βB = 1.1 ( Wide - angle end state ) = 1.9 ( Intermediate focal length state ) = 2.1 ( Telephoto end state ) FIGS. 22A, 22B through 24A, 24B are graphs showing various aberrations of the zoom lens system according to Example 6 of the first embodiment of the present invention focusing at infinity at d-line (λ=587.6 nm). FIGS. 22A and 22B graphically show various aberrations in a wide-angle end state (f=28.8) in which FIG. 22A shows various aberrations without vibration reduction correction, and FIG. 22B shows coma with vibration reduction correction. FIGS. 23A and 23B graphically show various aberrations in an intermediate focal length state (f=100.0) in which FIG. 23A shows various aberrations without vibration reduction correction, and FIG. 23B shows coma with vibration reduction correction. FIGS. 24A and 24B graphically show various aberrations in a telephoto end state (f=288.0) in which FIG. 24A shows various aberrations without vibration reduction correction, and FIG. 24B shows coma with vibration reduction correction. As is apparent from the respective graphs, the zoom lens system according to Example 6 shows superb optical performance as a result of good corrections to various aberrations in each focal length state (the wide-angle end state, the intermediate focal length state, and the telephoto end state). [Second Embodiment] A zoom lens system according to a second embodiment includes, in order from the object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power. When the state of lens group positions varies from a wide-angle end state to a telephoto end state, at least the first lens group and the fourth lens group move to the object side such that a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group decreases. In a high zoom ratio zoom lens system, in order to correct variation in off-axis aberration upon varying state of lens group positions well, it is preferable that an aperture stop is arranged in the vicinity of the center of the lens system. Accordingly, in a zoom lens system according to the second embodiment of the present invention, the aperture stop is located in the vicinity of the third lens group, inclusive of inside of the third lens group. Here, the meaning of “the aperture stop is located in the vicinity of the third lens group” includes the meaning of “the aperture stop is located inside of the third lens group.” With the above-described construction, the zoom lens system according to the second embodiment can correct variation in various aberrations produced upon shifting an image well by satisfying the following conditions (A), (B), and (C): (A) The third lens group is composed of, in order from the object, a first sub-lens group, a second sub-lens group, and a third sub-lens group, and the image shift is carried out by shifting the second sub-lens group substantially perpendicularly to the optical axis. (The second sub-lens group is the shift lens group.) (B) A distance between the second sub-lens group and the aperture stop is set suitably. (C) The focal length of the whole lenses locating to the object side of the second sub-lens group is set suitably. Condition (A) is for preferably correcting variation in various aberrations produced upon shifting the image and upon varying the state of lens group positions. In a zoom lens system according to the second embodiment, aberration correction function is separated such that the whole third lens group preferably corrects variation in various aberrations produced upon varying the state of lens group positions and the second sub-lens group (shift lens group) preferably corrects variation in various aberrations produced upon shifting the image. Accordingly, variation in various aberrations produced upon varying the state of lens group positions as well as that upon shifting the image can be corrected preferably. Condition (B) is for preferably correcting variation in off-axis aberrations produced upon shifting the image. Generally, an off-axis ray incident to a lens group locating in the vicinity of an aperture stop passes through the lens group near to the optical axis. On the other hand, an off-axis ray incident to a lens group locating away from the aperture stop passes through the lens group away from the optical axis. The surface shape of each lens surface is a sphere rotationally symmetrical around the optical axis. Accordingly, when the shift lens group is shifted substantially perpendicularly to the optical axis, refractive power in the direction of the shift and that in the opposite direction vary reversely with each other. In other words, among light rays incident to the shift lens group, a light ray incident to the shift-direction side refracts near to the optical axis and a light ray incident to the opposite-to-shift-direction side refracts away from the optical axis. Accordingly, variation in off-axis aberrations tends to occur. Condition (C) is for preferably correcting variation in on-axis aberrations produced upon shifting the image. When off-axis rays incident to the second sub-lens group are substantially parallel, the bundle of rays incident to the lens system with parallel to the optical axis moves its image position in response to the shift of the second sub-lens group. However, variation in aberration is small. When the focal length of the lens elements locating to the object side of the second sub-lens group is negative as a whole, since on-axis rays are divergently incident to the second sub-lens group, spherical aberration cannot be corrected sufficiently. Accordingly, when the lens elements locating to the object side of the second sub-lens group has positive refractive power as a whole and the positive refractive power is not so strong, variation in on-axis aberrations can be corrected preferably. Then, respective conditional expressions are explained below. The following conditional expression (3) is for numerically defining the above-described condition (B) and defines a distance between an aperture stop and the second sub-lens group arranged in the third lens group in the wide-angle end state: 0.05<Ds/fw<0.7 (3) where Ds denotes a distance along the optical axis between an aperture stop and the lens surface of the second sub-lens group locating nearest to the aperture stop, and fw denotes the focal length of the zoom lens system in the wide-angle end state. When the ratio Ds/fw is equal to or exceeds the upper limit of conditional expression (3), off-axis ray incident to the shift lens group passes excessively away from the optical axis in the wide-angle end state. Accordingly, variation in off-axis aberrations producing upon shifting an image cannot be corrected preferably. On the other hand, when the ratio Ds/fw is equal to or falls below the lower limit of conditional expression (3), sufficient space cannot be secured between the aperture stop and the shift lens group, so that an interference between the aperture stop and the shift lens group occurs at small aperture (when stopping down the aperture small). Otherwise, it is likely to happen that the shift lens group contacts the aperture stop upon manufacturing in accordance with tolerance of each part. The following Conditional expression (4) is for numerically defining the above-described condition (C): 0.1<ft/fA<1.5 (4) where fA denotes the focal length of the whole lens elements locating to the object side of the second sub-lens group in the telephoto end state, and ft denotes the focal length of the zoom lens system in the telephoto end state. When the ratio ft/fA is equal to or exceeds the upper limit of conditional expression (4), on-axis ray is incident to the second sub-lens group converging excessively. Accordingly, variation in on-axis aberrations producing upon shifting an image becomes excessively large. On the other hand, when the ratio ft/fA is equal to or falls below the lower limit of conditional expression (4), on-axis ray is divergently incident to the second sub-lens group. Accordingly, on-axis aberrations cannot be corrected sufficiently. The diameter of the second sub-lens group directly relates to the dimension of a driver for shifting the second sub-lens group substantially perpendicularly to the optical axis. Accordingly, in order to increase portability by miniaturizing the diameter of the second sub-lens group, it is preferable to set the lower limit of conditional expression (4) to 0.15. With the construction described above, the zoom lens system according to the second embodiment of the present invention may preferably correct variation in various aberrations producing upon shifting an image and accomplish miniaturizing the lens diameter by constructing respective sub-lens groups of the third lens group satisfying the following conditions (D), (E), and (F): (D) Refractive power of the first sub-lens group is set to positive and the focal length thereof is set suitably. (E) Refractive power of the second sub-lens group is set to positive and the shape thereof is set suitably. (F) Refractive power of the third sub-lens group is set to negative. Condition (D) is for accomplishing compactness and preferably correcting aberrations at the center of the image frame in the telephoto end state. In the zoom lens system according to the second embodiment of the present invention, combined refractive power of the first lens group and the second lens group is negative. Accordingly, in the zoom lens system according to the second embodiment of the present invention in order to satisfy condition (C), the first sub-lens group locating between the second lens group and the second sub-lens group has positive refractive power. In order to accomplish compactness, it is effective that refractive power of the first sub-lens group is set to a large value. However, when refractive index of the first sub-lens becomes too large, negative spherical aberration cannot be corrected sufficiently in the telephoto end state. Accordingly, in the zoom lens system according to the second embodiment of the present invention, it is preferable to satisfy the following conditional expression (5): 0.06<fa/ft<0.2 (5) where fa denotes the focal length of the first sub-lens group, and ft denotes the whole zoom lens system in the telephoto end state. Conditional expression (5) defines the focal length of the first sub-lens group. When the ratio fa/ft is equal to or exceeds the upper limit of conditional expression (5), total lens length of the zoom lens system in the telephoto end state becomes large. On the other hand, when the ratio fa/ft is equal to or falls below the lower limit of conditional expression (5), negative spherical aberration producing in the telephoto end state cannot be corrected preferably. Condition (E) is for preferably correcting decentering coma producing in the center of the image frame by the shift lens group alone upon shifting an image. Generally, image shifting can be carried out when the shift lens group has either positive refractive power or negative refractive power. In the zoom lens system according to the second embodiment of the present invention, since an angle of view in the wide-angle end state is large, when the shift lens group has negative refractive power, the light flux diverges. Accordingly, not only the lens diameter becomes large, but also coma produces severely since off-axis ray proceeding to the periphery of the image frame passes on the periphery of the lens. Therefore, in the zoom lens system according to the second embodiment of the present invention, the second sub-lens group, which is the shift lens group, has positive refractive power. Moreover, in order to preferably correct decentering coma producing at the center of the image frame by the shift lens group alone upon shifting an image, it is preferable to set the shape of the shift lens group suitably. For this purpose, it is necessary to satisfy sine condition in addition to preferably correcting spherical aberration producing by the shift lens group alone. Accordingly, in the zoom lens system according to the second embodiment of the present invention, the second sub-lens group includes at least one positive lens and one negative lens and the following conditional expression (6) is preferably satisfied: −0.6<(na/ra)/(nb/rb)<0 (6) where ra denotes a radius of curvature of the most object side lens surface of the second sub-lens group, na denotes refractive index at d-line of the most object side lens of the second sub-lens group, rb denotes a radius of curvature of the most image side lens surface of the second sub-lens group, nb denotes refractive index at d-line of the most image side lens of the second sub-lens group. Conditional expression (6) is for suitably defining the shape of the second sub-lens group and for preferably correcting decentering coma producing at the center of the image frame by the shift lens group alone upon shifting an image. As described above, the zoom lens system according to the second embodiment of the present invention corrects spherical aberration produced by the shift lens group alone as well as satisfies the sine condition. When the ratio (na/ra)/(nb/rb) is equal to or exceeds the upper limit of conditional expression (6), sine condition becomes largely negative producing inner coma severely at the center of the image frame upon shifting an image. On the other hand, when the ratio is equal to or falls below the lower limit of conditional expression (6), sine condition becomes largely positive producing outer coma severely at the center of the image frame upon shifting an image. The zoom lens system according to the second embodiment of the present invention preferably corrects variation in various aberrations upon changing focal length state by making aberration correction function of each lens group clear. The zoom lens system according to the second embodiment of the present invention is constructed such that the distance between the first lens group and the second lens group is small as much as possible, and the distance between the second lens group and the aperture stop is suitably large in the wide-angle end state. With this construction, off-axis ray passing through the first lens group passes near to the optical axis, and off-axis ray passing through the second lens group passes away from the optical axis. In the zoom lens system according to the second embodiment of the present invention, when the state of lens group positions varies from the wide angle end state to the telephoto end state, the first lens group and the second lens group are moved such that a distance between the first lens group and the second lens group increases, and a distance between the second lens group and the aperture stop decreases. With this construction, off-axis ray passing through the first lens group passes away from the optical axis, and off-axis ray passing through the second lens group passes near to the optical axis. In the zoom lens system according to the second embodiment of the present invention as described above, by varying the heights of off-axis ray passing through the first lens group and the second lens group, variation in off-axis aberrations producing upon varying the state of lens group positions is corrected preferably. In the zoom lens system according to the second embodiment of the present invention, a distance between the third lens group and the fourth lens group becomes large in the wide-angle end state. Accordingly, off-axis ray passing through the fourth lens group passes away from the optical axis. In the zoom lens system according to the second embodiment of the present invention, when the state of lens group positions varies from the wide-angle end state to the telephoto end state, the distance between the third lens group and the fourth lens group decreases. Accordingly, off-axis ray passing through the fourth lens group passes near to the optical axis, so that variation in off-axis aberrations producing upon varying the state of lens group positions is corrected preferably. In the zoom lens system according to the second embodiment of the present invention as described above, the first lens group mainly corrects off-axis aberration producing in the telephoto end state, the second lens group mainly corrects off-axis aberrations producing in the wide-angle end state, and the fourth lens group also mainly corrects off-axis aberrations producing in the wide-angle end state. By the way, the function for correcting aberrations is different between the second lens group and the fourth lens group since these two lens groups are located to the object side and image side of the aperture stop, respectively. In the zoom lens system according to the second embodiment of the present invention, the aperture stop is located in the vicinity of the third lens group and off-axis ray passing through the third lens group passes near to the optical axis, so that production of off-axis aberration is small. Accordingly, the third lens group mainly corrects on-axis aberrations. In the zoom lens system according to the second embodiment of the present invention, on-axis light bundle coming out from the third lens group approaches parallel. Accordingly, by varying the distance between the third lens group and the fourth lens group off-axis aberration alone can be varied without varying on-axis aberrations, so that variation in curvature of field producing upon varying the state of lens group positions is corrected preferably. Condition (F) is for bringing off-axis light bundle coming out from the third lens group close to parallel. In the zoom lens system according to the second embodiment of the present invention, since the first sub-lens group and the second sub-lens group in the third lens group have positive refractive power, in order to bring off-axis light bundle coming out from the third lens group close to parallel, it is preferable that the third sub-lens group has negative refractive power. The zoom lens system according to the second embodiment of the present invention preferably satisfies the following conditional expression (7): 0.5<|fc|/f3<0.9 (7) where fc denotes the focal length of the third sub-lens group and f3 denotes the focal length of the third lens group. Conditional expression (7) is for suitably defining the focal length of the third sub-lens group in order to accomplish high optical performance of the zoom lens system according to the second embodiment of the present invention. When the ratio |fc|/f3 is equal to or exceeds the upper limit of conditional expression (7), negative distortion produced in the wide-angle end state cannot be corrected preferably. On the other hand, when the ratio |fc|/f3 is equal to or falls below the lower limit of conditional expression (7), positive spherical aberration produced at the third sub-lens group cannot be corrected preferably. In the zoom lens system according to the second embodiment of the present invention, the third sub-lens group has a negative lens having a concave surface facing to the object locating to the most object side, and the following conditional expression (8) is preferably satisfied: 0.5<|rc|/f3<0.75 (8) where rc denotes a radius of curvature of the object side surface of the negative lens locating to the most object side of the third sub-lens group, and f3 denotes the focal length of the third lens group. Conditional expression (8) is for preferably correcting variation in various aberrations producing upon shifting an image, and defining a radius of curvature of the object side surface of the negative lens locating to the most object side of the third sub-lens group. When the ratio |rc|/f3 is equal to or exceeds the upper limit of conditional expression (8), optical performance on the periphery of the image frame in the wide-angle end state upon shifting an image is severely degraded. On the other hand, when the ratio |rc|/f3 is equal to or falls below the lower limit of conditional expression (8), optical performance at the center of the image frame in the telephoto end state upon shifting an image is severely degraded. In the zoom lens system according to the second embodiment of the present invention, by suitably arranging an aspherical lens, higher optical performance can be obtained. In order to increase optical performance at the center of the image frame regardless of the state of lens group positions, it is preferable that a lens surface of the first sub-lens group in the third lens group is an aspherical surface. In order to correct variation in coma produced upon varying an angle of view in the wide-angle end state ideally, it is preferable that at least one lens surface of the second lens group or the fourth lens group is an aspherical surface. Moreover, by arranging aspherical lenses in both of the second lens group and the fourth lens group, further high optical performance can be obtained. In the zoom lens system according to the second embodiment of the present invention, when focusing at close object, in order to suppress variation in various aberrations it is preferable that the second lens group is moved along the optical axis. The present invention is not limited to a zoom lens system, but is preferably applied to a so-called variable focal length lens whose focal length does not exist continuously. The zoom lens system according to the second embodiment of the present invention can be applied to an optical system using a photoelectric converter such as a CCD as an imaging device by keeping an exit pupil from the image plane with arranging an additional lens to the image side of the fourth lens group. The reason is that when a photoelectric device is used for an imaging device, the position of an exit pupil has to be kept away from the image plane since a micro lens array is arranged right in front of the imaging device. When detected light quantity is small, noise tends to produce and an exposure cannot be completed within short time. Accordingly, the micro lens array is arranged for increasing detected light quantity. The zoom lens system according to the second embodiment of the present invention is composed of, in order from an object, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, and a fourth lens group G4 having positive refractive power. When the state of lens group positions varies from a wide-angle end state (W) to a telephoto end state (T), at least the first lens group G1 and the fourth lens group G4 are moved to the object side such that a distance between the first lens group G1 and the second lens group G2 increases, a distance between the second lens group G2 and the third lens group G3 decreases, and a distance between the third lens group G3 and the fourth lens group G4 decreases. EXAMPLE 7 FIG. 26 is a diagram showing the lens arrangement of a zoom lens system according to Example 7 of the second embodiment of the present invention. In a zoom lens system according to Example 7 of the second embodiment, the first lens group G1 is composed of, in order from the object, a cemented lens L11 constructed by a negative meniscus lens having a convex surface facing to the object cemented with a positive lens having a convex surface facing to the object, and a positive meniscus lens L12 having a convex surface facing to the object. The second lens group G2 is composed of, in order from the object, a negative lens L21 having a concave surface facing to an image, a negative lens L22 having a concave surface facing to the object, a positive lens L23 having a convex surface facing to the object, and a negative lens L24 having a concave surface facing to the object. The third lens group G3 is composed of, in order from the object, a cemented positive lens L31 constructed by a double convex positive lens and a negative lens having a concave surface facing to the object, a cemented positive lens L32 constructed by a double convex positive lens cemented with a negative lens having a concave surface facing to the object, and a negative lens L33 having a concave surface facing to the object. The fourth lens group G4 is composed of, in order from the object, a positive lens L41 having a convex surface facing to the image, a cemented lens L42 constructed by a double convex positive lens cemented with a negative lens having a concave surface facing to the object. In a zoom lens system according to Example 7 of the second embodiment, an aperture stop S is arranged to the object side of the third lens group G3 and is moved together with the third group G3 upon varying the state of lens group positions. A thin resin layer having an aspherical surface is arranged to the object side surface of the negative lens L21 in the second lens group G2. In the zoom lens system according to Example 7 of the second embodiment, the cemented positive lens L31, the cemented positive lens L32, and the negative lens L33 in the third lens group G3 work as the first sub-lens group, the second sub-lens group, and the third sub-lens group, respectively. Various values according to Example 7 are listed in Table 7. TABLE 7 [Specifications] Wide-angle Intermediate Telephoto f = 28.80 100.00 291.01 mm 2ω = 76.85 23.73 8.27° FNO = 3.70 5.31 5.90 [Lens Data] Surface Number r d ν n 1 90.3212 1.900 23.78 1.84666 2 65.4471 7.850 81.61 1.49700 3 −927.1234 0.100 4 62.8419 4.950 81.61 1.49700 5 160.5701 (D5) 6 82.3260 0.300 52.42 1.51742 7 81.0734 1.150 54.66 1.72916 8 15.7871 6.000 9 −48.6106 1.000 52.32 1.75500 10 67.3687 0.100 11 30.3042 3.750 23.78 1.84666 12 −77.9581 1.400 13 −28.3626 0.900 46.58 1.80400 14 481.9617 (D14) 15 0.0000 2.200 Aperture Stop 16 22.2500 6.000 61.18 1.58913 17 −36.1506 0.800 37.17 1.83400 18 −89.4952 6.800 19 31.1943 4.950 65.47 1.60300 20 −34.5962 0.800 28.39 1.79504 21 −95.5120 3.050 22 −24.5379 0.800 37.17 1.83400 23 135.1604 (D23) 24 79.6117 4.900 64.14 1.51633 25 −29.6445 0.100 26 317.9892 8.100 33.80 1.64769 27 −14.2806 0.900 42.72 1.83481 28 −183.2245 (Bf) [Aspherical Data] Surface Number 6 κ = −4.2585 C4 = 4.4810E−6 C6 = 1.2417E−8 C8 = −1.0672E−10 C10 = 3.1231E−13 Surface Number 16 κ = 1.0000 C4 = −3.9585E−6 C6 = 4.2904E−9 C8 = −8.0515E−12 C10 = 4.2777E−14 Surface Number 24 κ = 1.0000 C4 = 1.0383E−5 C6 = −1.4668E−8 C8 = 1.2224E−10 C10 = −1.4347E−12 Wide-angle Intermediate Telephoto [Variable Intervals] f 28.8002 100.0049 291.0057 D5 1.5083 36.2039 61.0436 D14 26.4577 11.8866 0.8000 D23 7.4610 3.6316 3.0000 BF 39.5005 75.2032 89.4717 [Shift Amount of Shifting lens group] f 28.8002 100.0049 291.0057 δb 0.1114 0.2425 0.6095 where δb denotes a shift amount of the second sub-lens group for shifting an image corresponding to a half angle of view of 0.3 degrees. [Values for Conditional Expressions] fA=552.282 fa=34.860 fc=−24.845 f3=37.103 (1) Ds/fw=0.549 (2) ft/fA=0.527 (3) fa/ft=0.120 (4)(na/ra)/(nb/rb)=−0.366 (5)|fc|/f3=0.670 (6)|rc|/f3=0.661 FIGS. 27A, 27B, and 27C graphically show various aberrations of the zoom lens system according to Example 7 of the second embodiment focusing at infinity in a wide-angle end state (f=28.80), an intermediate focal length state (f=100.00), and a telephoto end state (f=291.00), respectively. FIGS. 28A, 28B, and 28C graphically show coma of the zoom lens system according to Example 7 focusing at infinity in a wide-angle end state (f=28.80), an intermediate focal length state (f=100.00), and a telephoto end state (f=291.00), respectively, when a second sub-lens group is shifted the amount shown in Table 7. FIGS. 27A-27C and 28A-28C show various aberrations at d-line (λ=587.6 nm). In FIGS. 27A, 27B, and 27C, FNO denotes the f-number, ω denotes a half angle of view (unit: degree), and Y denotes an image height. In the graph showing spherical aberration, f-number shows the value at the maximum aperture. In the graphs showing astigmatism and distortion, the maximum value of Y is shown. In the graph showing coma, a half angle of view ω and each image height 0, 10.8, 15.12, 18.34, and 21.6 are shown. In the graph showing spherical aberration, a solid line indicates spherical aberration and a broken line indicates sine condition. In the graph showing astigmatism, a solid line indicates a sagittal image plane and a broken line indicates a meridional plane. In FIGS. 28A, 28B, and 28C, ω denotes a half angle of view, and Y denotes an image height. In FIGS. 28A-28C, values corresponding to the image height Y=−15.0, 0.0, and 15.0 are shown. The above-described explanation regarding various aberration graphs is the same as the other examples. As is apparent from FIGS. 27A, 27B, and 27C, the zoom lens system according to Example 7 of the second embodiment shows superb optical performance as a result of good corrections to various aberrations in each focal length state. As is apparent from FIGS. 28A, 28B, and 28C, the zoom lens system according to Example 7 of the second embodiment shows superb optical performance as a result of good corrections to variation in various aberrations upon shifting an image. EXAMPLE 8 FIG. 29 is a diagram showing the lens arrangement of a zoom lens system according to Example 8 of the second embodiment of the present invention. In a zoom lens system according to Example 8 of the second embodiment, the first lens group G1 is composed of, in order from the object, a cemented lens L11 constructed by a negative meniscus lens having a convex surface facing to the object cemented with a positive lens having a convex surface facing to the object, and a positive meniscus lens L12 having a convex surface facing to the object. The second lens group G2 is composed of, in order from the object, a negative lens L21 having a concave surface facing to an image, a negative lens L22 having a concave surface facing to the object, a positive lens L23 having a convex surface facing to the object, and a negative lens L24 having a concave surface facing to the object. The third lens group G3 is composed of, in order from the object, a cemented positive lens L31 constructed by a double convex lens and a negative lens having a concave surface facing to the object, a positive lens L32 having a convex surface facing to the object, a cemented positive lens L33 constructed by a double convex positive lens cemented with a negative lens having a concave surface facing to the object, and a cemented negative lens L34 constructed by a double concave negative lens cemented with a positive lens having a convex surface facing to the image. The fourth lens group G4 is composed of, in order from the object, a positive lens L41 having a convex surface facing to the image, a cemented lens L42 constructed by a double convex positive lens cemented with a negative lens having a concave surface facing to the object. In a zoom lens system according to Example 8 of the second embodiment, an aperture stop S is arranged in the third lens group G3 and is moved together with the third group G3 upon varying the state of lens group positions. A thin resin layer having an aspherical surface is arranged to the object side surface of the negative lens L21 in the second lens group G2. In the zoom lens system according to Example 8 of the second embodiment, the cemented positive lens L31 and the positive lens L32, the cemented positive lens L33, and the cemented negative lens L34 in the third lens group G3 work as the first sub-lens group, the second sub-lens group, and the third sub-lens group, respectively. Various values according to Example 8 are listed in Table 8. TABLE 8 [Specifications] Wide-angle Intermediate Telephoto f = 28.80 100.00 290.99 mm 2ω = 76.85 23.73 8.27° FNO = 3.99 5.31 5.90 [Lens Data] Surface Number r d ν n 1 93.2544 1.900 23.78 1.84666 2 67.4338 7.600 81.61 1.49700 3 −870.3714 0.100 4 63.9756 4.950 81.61 1.49700 5 169.1582 (D5) 6 170.7827 0.200 52.42 1.51742 7 116.1866 1.150 54.66 1.72916 8 17.5797 6.350 9 −44.1340 1.000 49.61 1.77250 10 69.9097 0.100 11 37.2520 4.300 23.78 1.84666 12 −47.1656 1.850 13 −25.1574 0.900 42.72 1.83481 14 −206.1842 (D14) 15 22.9038 5.250 60.29 1.62041 16 −75.3318 0.800 40.94 1.80610 17 1045.3379 0.100 18 100.0000 1.450 61.18 1.58913 19 167.7113 1.000 20 0.0000 4.750 (Aperture Stop) 21 33.2835 4.750 65.47 1.60300 22 −32.1197 0.800 25.43 1.80518 23 −82.2892 3.200 24 −23.5322 0.800 37.17 1.83400 25 323.3398 1.800 61.18 1.58913 26 −277.1591 (D26) 27 106.3107 5.500 61.18 1.58913 28 −31.4892 0.100 29 126.8073 8.100 33.04 1.66680 30 −15.4408 0.900 42.72 1.83481 31 233.8464 (Bf) [Aspherical Data] Surface Number 6 κ = −5.3669 C4 = 6.2843E−6 C6 = 7.3170E−9 C8 = −6.0486E−11 C10 = 1.9131E−13 Surface Number 18 κ = 1.0000 C4 = −2.8655E−6 C6 = 7.4080E−9 C8 = 3.4886E−11 C10 = −1.9586E−14 Surface Number 28 κ = 1.0000 C4 = 1.1991E−5 C6 = −8.1306E−9 C8 = 1.0850E−10 C10 = −7.3969E−13 Wide-angle Intermediate Telephoto [Variable Intervals] f 28.7990 99.9955 290.9864 D5 1.5536 35.9680 60.9566 D14 27.3832 12.2670 1.0000 D26 6.0825 2.2082 1.5269 BF 39.5688 75.2798 91.8252 [Shift Amount of Shifting lens group] f 28.7990 99.9955 290.9864 δb 0.1145 0.2479 0.6095 where δb denotes a shift amount of the second sub-lens group for shifting an image corresponding to a half angle of view of 0.3 degrees. [Values for Conditional Expressions] fA=1429.95 fa=37.913 fc=−29.443 f3=38.774 (1) Ds/fw=0.165 (2) ft/fA=0.203 (3) fa/ft=0.130 (4)(na/ra)/(nb/rb)=−0.455 (5)|fc|/f3=0.759 (6)|rc|/f3=0.607 FIGS. 30A, 30B, and 30C graphically show various aberrations of the zoom lens system according to Example 8 of the second embodiment focusing at infinity in a wide-angle end state (f=28.80), an intermediate focal length state (f=100.00), and a telephoto end state (f=290.99), respectively. FIGS. 31A, 31B, and 31C graphically show coma of the zoom lens system according to Example 8 focusing at infinity in a wide-angle end state (f=28.80), an intermediate focal length state (f=100.00), and a telephoto end state (f=290.99), respectively, when a second sub-lens group is shifted the amount shown in Table 8. As is apparent from FIGS. 30A, 30B, and 30C, the zoom lens system according to Example 8 of the second embodiment shows superb optical performance as a result of good corrections to various aberrations in each focal length state. As is apparent from FIGS. 31A, 31B, and 31C, the zoom lens system according to Example 8 of the second embodiment shows superb optical performance as a result of good corrections to variation in various aberrations upon shifting an image. EXAMPLE 9 FIG. 32 is a diagram showing the lens arrangement of a zoom lens system according to Example 9 of the second embodiment of the present invention. In a zoom lens system according to Example 9 of the second embodiment, the first lens group G1 is composed of, in order from the object, a cemented lens L11 constructed by a negative meniscus lens having a convex surface facing to the object cemented with a positive lens having a convex surface facing to the object, and a positive meniscus lens L12 having a convex surface facing to the object. The second lens group G2 is composed of, in order from the object, a negative lens L21 having a concave surface facing to an image, a negative lens L22 having a concave surface facing to the object, a positive lens L23 having a convex surface facing to the object, and a negative lens L24 having a concave surface facing to the object. The third lens group G3 is composed of, in order from the object, a cemented positive lens L31 constructed by a double convex positive lens and a negative lens having a concave surface facing to the object, a positive lens L32 having a convex surface facing to the object, a cemented positive lens L33 constructed by a double convex positive lens cemented with a negative lens having a concave surface facing to the object, and a cemented negative lens L34 constructed by a double concave negative lens cemented with a positive meniscus lens having a convex surface facing to the object. The fourth lens group G4 is composed of, in order from the object, a positive lens L41 having a convex surface facing to the image, a cemented lens L42 constructed by a double convex positive lens cemented with a negative lens having a concave surface facing to the object. In a zoom lens system according to Example 9 of the second embodiment, an aperture stop S is arranged to the object side of the third lens group G3 and is moved together with the third group G3 upon varying the state of lens group positions. A thin resin layer having an aspherical surface is arranged to the object side surface of the negative lens L21 in the second lens group G2. In the zoom lens system according to Example 9 of the second embodiment, the cemented positive lens L31 and the positive lens L32, the cemented positive lens L33, and the cemented negative lens L34 in the third lens group G3 work as the first sub-lens group, the second sub-lens group, and the third sub-lens group, respectively. Various values according to Example 9 are listed in Table 9. TABLE 9 [Specifications] Wide-angle Intermediate Telephoto f = 28.80 100.00 291.01 mm 2ω = 76.77 23.72 8.27° FNO = 3.70 5.32 5.90 [Lens Data] Surface Number r d ν n 1 92.4229 1.900 23.78 1.84666 2 66.7560 7.750 81.61 1.49700 3 −846.2717 0.100 4 63.6267 4.950 81.61 1.49700 5 165.9874 (D5) 6 128.4411 0.200 52.42 1.51742 7 101.5414 1.150 54.66 1.72916 8 17.1504 6.250 9 −46.5218 1.000 52.32 1.75500 10 66.4470 0.100 11 33.9329 4.200 23.78 1.84666 12 −53.7522 1.800 13 −26.2934 0.900 42.72 1.83481 14 −885.5810 (D14) 15 0.0000 2.200 (Aperture Stop) 16 23.3505 7.000 61.18 1.58913 17 −25.1524 0.800 46.58 1.80400 18 −280.9645 0.100 19 37.9321 3.200 64.14 1.51633 20 −414.9721 4.050 21 34.8328 3.850 52.32 1.75500 22 −60.1069 0.800 23.78 1.84666 23 −456.9696 3.100 24 −21.2766 0.800 37.17 1.83400 25 32.5985 2.650 70.24 1.48749 26 863.3676 (D26) 27 145.6193 3.600 64.14 1.51633 28 −30.7860 0.100 29 629.7219 7.700 33.04 1.66680 30 −13.2652 0.900 42.72 1.83481 31 −80.0893 (Bf) [Aspherical Data] Surface Number 6 κ = −4.2585 C4 = 4.4810E−6 C6 = 1.2417E−8 C8 = −1.0672E−10 C10 = 3.1231E−13 Surface Number 16 κ = 1.0000 C4 = −3.9585E−6 C6 = 4.2904E−9 C8 = −8.0515E−12 C10 = 4.2777E−14 Surface Number 28 κ = 1.0000 C4 = 1.0383E−5 C6 = −1.4668E−8 C8 = 1.2224E−10 C10 = −1.4347E−12 Wide-angle Intermediate Telephoto [Variable Intervals] f 28.8001 100.0017 291.0077 D5 1.5358 36.1674 61.1207 D14 27.1675 12.0649 0.8000 D26 6.3826 2.6488 2.0000 BF 39.5003 75.7001 90.8947 [Shift Amount of Shifting lens group] f 28.8001 100.0017 291.0077 δb 0.1123 0.2444 0.6095 where δb denotes a shift amount of the second sub-lens group for shifting an image corresponding to a half angle of view of 0.3 degrees. [Values for Conditional Expressions] fA=224.755 fa=30.182 fc=−19.750 f3=35.153 (1) Ds/fw=0.602 (2) ft/fA=1.295 (3) fa/ft=0.104 (4)(na/ra)/(nb/rb)=−0.080 (5)|fc|/f3=0.562 (6)|rc|/f3=0.605 FIGS. 33A, 33B, and 33C graphically show various aberrations of the zoom lens system according to Example 9 of the second embodiment focusing at infinity in a wide-angle end state (f=28.80), an intermediate focal length state (f=100.00), and a telephoto end state (f=291.00), respectively. FIGS. 34A, 34B, and 34C graphically show coma of the zoom lens system according to Example 9 focusing at infinity in a wide-angle end state (f=28.80), an intermediate focal length state (f=100.00), and a telephoto end state (f=291.00), respectively, when a second sub-lens group is shifted the amount shown in Table 9. As is apparent from FIGS. 33A, 33B, and 33C, the zoom lens system according to Example 9 of the second embodiment shows superb optical performance as a result of good corrections to various aberrations in each focal length state. As is apparent from FIGS. 34A, 34B, and 34C, the zoom lens system according to Example 9 of the second embodiment shows superb optical performance as a result of good corrections to variation in various aberrations upon shifting an image. As described above, the present invention makes it possible to provide a high zoom ratio zoom lens system capable of shifting an image by shifting one or some of lens elements consisting of the zoom lens system substantially perpendicularly to the optical axis, having relatively short total lens length in the wide-angle end state, with small variation in the total lens length upon varying the state of lens group positions from the wide-angle end state to the telephoto end state. Additional advantages and modification will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, and representative devices shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a zoom lens system and in particular to a high zoom ratio zoom lens system capable of shifting an image. 2. Related Background Art An optical system capable of moving (shifting) an image perpendicularly to the optical axis by moving (shifting) one or some of lens elements constructing the optical system substantially perpendicularly to the optical axis has been known. As for such optical systems, a zoom lens system capable of shifting an image by shifting one or some of lens elements provided in the zoom lens system has been proposed (see, for example, Japanese Patent Application Laid-Open No. 2003-140048 and Japanese Patent Application Laid-Open No. 2-081020). In the present specification, one or some of lens elements being shifted substantially perpendicularly to the optical axis is hereinafter called a shift lens group. Recently, a zoom lens has widely used as a photographic lens. When a zoom lens is used as a photographic lens, it makes you possible to take a photograph closer to the subject, so it has a merit that you can take a photograph just as you intend. According to popularization of a zoom lens as a photographic lens, a high zoom ratio zoom lens capable of shooting closer to the subject has come onto the market. As a high zoom ratio zoom lens capable of shooting closer to the subject, a positive-negative-positive-positive four-lens-group type zoom lens has been known (see, for example, Japanese Patent Application Laid-Open No. 2001-117005 and Japanese Patent Application Laid-Open No. 11-142739). A positive-negative-positive-positive type zoom lens is composed of, in order from the object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power. When the state of lens group positions varies from a wide-angle end state (which gives the shortest focal length) to a telephoto end state (which gives the longest focal length), at least the first lens group and the fourth lens group move to the object side such that a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group decreases. According to further popularization of a zoom lens as a photographic lens, in order to meet user's expectation to improve portability, compact and lightweight zoom lenses have been proposed. On the other hand, in particular for a compact and lightweight zoom lens, an image tends to be blurred during exposure by minute vibration produced on a camera while shooting such as a camera shake caused by a photographer upon releasing a shutter button. When the amount of the camera vibration is assumed to be constant, the amount of image blurring increases in accordance with the increase in the focal length of the lens, so the minute camera vibration causes severe deterioration on the image. Accordingly, a method for compensating the above-described image blur caused by the camera shake by combining a zoom lens capable of shifting an image with a driver, a detector and a controller has been known (see, for example, Japanese Patent Application Laid-Open No. 10-282413). In such zoom lens, the detector detects a camera shake. The controller controls the shift lens group giving the driver a driving amount in order to correct the shake detected by the detector. The driver corrects the image blur caused by the camera shake by driving the shift lens group substantially perpendicularly to the optical axis. Generally, in a zoom lens, it is necessary to correct various aberrations for each lens group to obtain given optical performance as a whole zoom lens. The state of aberration correction required to each lens group has a certain range, and the range generally becomes narrow when the zoom ratio becomes large. On the other hand, in an optical system capable of shifting an image, in order to suppress variation in various aberrations produced upon shifting an image, there is a state of aberration correction required for the shift lens group only. Accordingly, the state of aberration correction required for the shift lens group in order to obtain good optical performance when the zoom ratio becomes large is completely different from that required for the shift lens group in order to correct aberrations produced upon shifting an image to obtain good optical performance. Therefore, it is very difficult to combine to attain a high zoom ratio and to construct an optical system capable of shifting an image. A conventional zoom lens having vibration reduction correction disclosed in Japanese Patent Application Laid-Open No. 2003-140048, however, has a large number of lens elements, and a vibration reduction mechanism has to be put into the lens barrel. Accordingly, the total lens length and the diameter of the lens barrel become large, so the compactness tends to be spoiled. Moreover, when the zoom lens is made to be a high zoom ratio with having a vibration reduction correction, deterioration in optical performance is severe, so that it becomes difficult to maintain sufficient optical performance as a zoom lens. A zoom lens disclosed in Japanese Patent Application Laid-Open No. 10-282413 has a large number of lens elements, so that when the state of lens group positions varies from the wide-angle end state to the telephoto end state, degree of freedom for selecting zoom trajectory of each lens group is large. Accordingly, high optical performance can be obtained. However, the driving mechanism for moving each lens group becomes complicated and the factors to produce mutual decentering of each lens group upon manufacturing increase, so that it becomes difficult to secure stable optical performance. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention is made in view of the aforementioned problems and has an object to provide a high zoom ratio zoom lens capable of shifting an image, which can carry out vibration reduction correction and accomplish a high zoom ratio. According to one aspect of the present invention, a zoom lens system includes, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power. Each of the first lens group through the fourth lens group move such that when the state of lens group positions varies from a wide-angle end state to a telephoto end state, a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group decreases. The third lens group includes at least two sub-lens groups having positive refractive power. An image is shifted by moving either of the two sub-lens groups as a shift lens group perpendicularly to the optical axis. The following conditional expression (1) is satisfied: in-line-formulae description="In-line Formulae" end="lead"? 0.120 <DT/ft< 0.245 (1) in-line-formulae description="In-line Formulae" end="tail"? where DT denotes an air space between the most image side lens surface of the first lens group and the most object side lens surface of the second lens group in the telephoto end state, and ft denotes the focal length of the zoom lens system in the telephoto end state. In one preferred zoom lens system of the one aspect of the present invention, the following conditional expression (2) is preferably satisfied: in-line-formulae description="In-line Formulae" end="lead"? 0.8<(1 −βA )×β B< 3.5 (2) in-line-formulae description="In-line Formulae" end="tail"? where βA denotes the lateral magnification of the shift lens group and βB denotes the lateral magnification of the optical elements locating between the shift lens group and an image plane. In one preferred zoom lens system of the one aspect of the present invention, the third lens group consists of, in order from the object, a third A lens group having positive refractive power, a third B lens group having positive refractive power, and a third C lens group having negative refractive power. The shift lens group having positive refractive power is the third B lens group. In one preferred zoom lens system of the one aspect of the present invention, the shift lens group includes at least one aspherical surface. In one preferred zoom lens system of the one aspect of the present invention, the second lens group includes at least three negative lenses and one positive lens. In one preferred zoom lens system of the one aspect of the present invention, the third A lens group consists of two positive lenses and one negative lens. In one preferred zoom lens system of the one aspect of the present invention, the third B lens group consists of one positive lens and one negative lens. In one preferred zoom lens system of the one aspect of the present invention, the fourth lens group includes at least one aspherical surface having a shape that positive refractive power becomes weak from the center to the periphery of the lens surface. According to another aspect of the present invention, a zoom lens system includes, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power. At least the first lens group and the fourth lens group move to the object side such that when the state of lens group positions varies from a wide-angle end state to a telephoto end state a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group decreases. The third lens group includes a first sub-lens group, a second sub-lens group, and a third sub-lens group. The second sub-lens group is arranged to the image side of the first sub-lens group with an air space. The third sub-lens group is arranged to the image side of the second sub-lens group with an air space. An image is shifted by moving the second sub-lens groups shifting substantially perpendicularly to the optical axis. An aperture stop is arranged in the vicinity of the third lens group including inside of the third lens group. The following conditional expressions (3) and (4) are satisfied: in-line-formulae description="In-line Formulae" end="lead"? 0.05 <Ds/fw< 0.7 (3) in-line-formulae description="In-line Formulae" end="tail"? in-line-formulae description="In-line Formulae" end="lead"? 0.1 <ft/fA< 1.5 (4) in-line-formulae description="In-line Formulae" end="tail"? where Ds denotes a distance along the optical axis between the aperture stop and the nearest lens surface of the second sub-lens group, fw denotes the focal length of the zoom lens system in the wide-angle end state, fA denotes the focal length of the whole lenses locating to the object side of the second sub-lens group in the telephoto end state, and ft denotes the focal length of the zoom lens system in the telephoto end state. In one preferred zoom lens system of the another aspect of the present invention, the first sub-lens group has positive refractive power and the following conditional expression (5) is preferably satisfied: in-line-formulae description="In-line Formulae" end="lead"? 0.06 <fa/ft< 0.2 (5) in-line-formulae description="In-line Formulae" end="tail"? where fa denotes the focal length of the first sub-lens group. In one preferred zoom lens system of the another aspect of the present invention, the second sub-lens group includes at least one positive lens and one negative lens, and has positive refractive power. The following conditional expression (6) is preferably satisfied: in-line-formulae description="In-line Formulae" end="lead"? −0.6<( na/ra )/( nb/rb )<0 (6) in-line-formulae description="In-line Formulae" end="tail"? where ra denotes a radius of curvature of the most object side lens surface of the second sub-lens group, na denotes refractive index at d-line of the most object side lens of the second sub-lens group, rb denotes a radius of curvature of the most image side lens surface of the second sub-lens group, and nb denotes refractive index at d-line of the most image side lens of the second sub-lens group. In one preferred zoom lens system of the another aspect of the present invention, the third sub-lens group has negative refractive power and the following conditional expression (7) is preferably satisfied: in-line-formulae description="In-line Formulae" end="lead"? 0.5 <|fc|/f 3<0.9 (7) in-line-formulae description="In-line Formulae" end="tail"? where fc denotes the focal length of the third sub-lens group, and f3 denotes the focal length of the third lens group. In one preferred zoom lens system of the another aspect of the present invention, the third sub-lens group includes a negative lens having a concave surface facing to the object locating to the most object side and the following conditional expression (8) is preferably satisfied: in-line-formulae description="In-line Formulae" end="lead"? 0.5 <|rc|/f 3<0.75 (8) in-line-formulae description="In-line Formulae" end="tail"? where rc denotes a radius of curvature of the negative lens locating to the most object side of the third sub-lens group. Other feature and advantages according to the present invention will be readily understood from the detailed description of the preferred embodiments in conjunction with the accompanying drawings. | 20040225 | 20061114 | 20050421 | 75591.0 | 0 | DINH, JACK | ZOOM LENS SYSTEM | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,785,236 | ACCEPTED | perpendicular pole tip and method of fabrication | A method for forming a magnetic structure, such as a pole tip, includes forming a pole tip layer of magnetic material. A layer of polyimide precursor material is added above the pole tip layer and cured. A silicon-containing resist layer is added above the layer of polyimide precursor material and patterned. The resist layer is exposed to oxygen plasma for converting the resist into a glass-like material. Exposed portions of the cured polyimide precursor material are removed for exposing portions of the pole tip layer. The exposed portions of the pole tip layer are removed for forming a pole tip. Chemical mechanical polishing (CMP) can then be performed to remove any unwanted material remaining above the pole tip. | 1. A method for forming a pole tip, comprising: forming a pole tip layer of magnetic material; adding a layer of polyimide precursor material above the pole tip layer; curing the polyimide precursor material; adding an oxygen etch resistant resist layer above the layer of polyimide precursor material; patterning the etch resistant layer; exposing the polyamide precursor material layer to oxygen-containing plasma; removing exposed portions of the cured polyimide precursor material for exposing portions of the pole tip layer; and removing the exposed portions of the pole tip layer for forming a pole tip. 2. A method as recited in claim 1, wherein the curing converts at least a substantial portion of the polyimide precursor material to at least one of a polyimide and a polyimide-like material. 3. A method as recited in claim 1, wherein the oxygen etch-resistant layer is a silicon-containing resist. 4. A method as recited in claim 1, wherein the oxygen etch-resistant layer consists of a sputtered film. 5. A method as recited in claim 1, wherein the exposed portions of the cured polyimide precursor material are removed by reactive ion etching. 6. A method as recited in claim 1, wherein the exposed portions of the pole tip layer are removed by milling. 7. A method as recited in claim 1, further comprising adding a first layer of material resistant to chemical mechanical polishing above the pole tip layer. 8. A method as recited in claim 1, further comprising adding a layer of nonmagnetic material for substantially encapsulating the pole tip. 9. A method as recited in claim 8, further comprising adding a second layer of material resistant to chemical mechanical polishing above the layer of nonmagnetic material. 10. A method as recited in claim 1, wherein the remaining portion of the pole tip layer has a width of less than about 100 nm. 11. A pole tip formed according to the method recited in claim 1. 12. A method for forming a pole tip, comprising: forming a pole tip layer of magnetic material; adding a first layer of material resistant to chemical mechanical polishing above the pole tip layer; adding a layer of polyimide precursor material above the first layer of material resistant to chemical mechanical polishing; baking the polyimide precursor material; adding an etch resistant layer above the layer of polyimide precursor material; patterning the etch resistant layer; removing exposed portions of the polyimide precursor material for exposing portions of the pole tip layer; removing the exposed portions of the pole tip layer for forming a pole tip; adding a layer of nonmagnetic material for substantially encapsulating the pole tip; adding a second layer of material resistant to chemical mechanical polishing above the layer of nonmagnetic material; and polishing for removing material above the first layer of material resistant to polishing. 13. A method for forming a magnetic structure, comprising: forming a layer of magnetic material; adding a first layer of material resistant to chemical mechanical polishing above the pole tip layer; adding a layer of polyimide precursor material above the first layer of material resistant to chemical mechanical polishing; baking the polyimide precursor material; adding an etch resistant layer above the layer of polyimide precursor material; patterning the etch resistant layer; removing exposed portions of the polyimide precursor material for exposing portions of the layer of magnetic material; removing the exposed portions of the layer of magnetic material; adding a layer of nonmagnetic material for substantially encapsulating the remaining portion of the layer of magnetic material; and polishing for removing material above the first layer of material resistant to polishing. 14. A method as recited in claim 13, wherein the etch resistant layer is formed of a silicon-containing resist. 15. A method as recited in claim 13, wherein the etch resistant layer is a glass-like material. 16. A method as recited in claim 13, wherein the baking converts at least a substantial portion of the polyimide precursor material to at least one of a polyimide and a polyimide-like material. 17. A method as recited in claim 13, wherein the layer of nonmagnetic material has a thickness at least as great as a thickness of the layer of magnetic material. 18. A method as recited in claim 13, wherein the layer of nonmagnetic material has a thickness greater than a thickness of the layer of magnetic material, wherein the layer of nonmagnetic material forms a plane that is above a top surface of the layer of magnetic material. 19. A method as recited in claim 13, further comprising adding a second layer of material resistant to chemical mechanical polishing above the layer of nonmagnetic material. 20. A method as recited in claim 19, wherein a lower surface of the second layer of material resistant to chemical mechanical polishing lies above a plane positioned above a plane extending along an upper surface of the pole tip. 21. A method as recited in claim 13, wherein the magnetic structure has a width of less than 100 mm. 22. A magnetic storage system, comprising: magnetic media; at least one head for reading from and writing to the magnetic media, each head having a pole tip formed according to the method of claim 1; a slider for supporting the head; and a control unit coupled to the head for controlling operation of the head. 23. A perpendicular pole tip structure, comprising: a pole tip layer of magnetic material having a top surface, a bottom surface, and sides extending between the top and bottom surface; layers of non-magnetic materials surrounding the layer of magnetic material towards the sides of the pole tip layer; and interface layers above the non-magnetic material, portions of the interface layers lying along a plane substantially parallel to the top surface of the pole tip layer; wherein portions of the interface layers taper towards the pole tip layer at a slope that is from about one to about five times a thickness of the pole tip layer, where the thickness of the pole tip layer is defined between the top and bottom surfaces thereof. 24. A perpendicular pole tip structure as recited in claim 23, wherein each of the interface layers includes a layer of chemical mechanical polishing resistant material. 25. A perpendicular pole tip structure as recited in claim 23, further comprising a layer of chemical mechanical polishing resistant material above the top surface of the pole tip layer. 26. A magnetic storage system, comprising: magnetic media; at least one perpendicular head for reading from and writing to the magnetic media, the head comprising: a pole tip layer of magnetic material having a top surface, a bottom surface, and sides extending between the top and bottom surface; layers of non-magnetic materials surrounding the layer of magnetic material towards the sides of the pole tip layer; and interface layers above the non-magnetic material, portions of the interface layers lying along a plane substantially parallel to the top surface of the pole tip layer, wherein portions of the interface layers taper towards the pole tip layer at a slope that is from about one to about five times a thickness of the pole tip layer, where the thickness of the pole tip layer is defined between the top and bottom surfaces thereof; a slider for supporting the head; and a control unit coupled to the head for controlling operation of the head. 27. A magnetic storage system as recited in claim 26, wherein each of the interface layers includes a layer of chemical mechanical polishing resistant material. 28. A magnetic storage system as recited in claim 26, further comprising a layer of chemical mechanical polishing resistant material above the top surface of the pole tip layer. | FIELD OF THE INVENTION The present invention relates to a method of patterning magnetic structures, and more particularly, this invention relates to a method of patterning particularly useful for perpendicular head fabrication. BACKGROUND OF THE INVENTION In a typical head, an inductive write head includes a coil layer embedded in first, second and third insulation layers (insulation stack), the insulation stack being located between first and second pole piece layers. A gap is formed between the first and second pole piece layers by a gap layer at an air bearing surface (ABS) of the write head. The pole piece layers are connected at a back gap. Currents are conducted through the coil layer, which produce magnetic fields in the pole pieces. The magnetic fields fringe across the gap at the ABS for the purpose of writing bits of magnetic field information in tracks on moving media, such as in circular tracks on a rotating magnetic disk or longitudinal tracks on a moving magnetic tape. The second pole piece layer has a pole tip portion which extends from the ABS to a flare point and a yoke portion which extends from the flare point to the back gap. The flare point is where the second pole piece begins to widen (flare) to form the yoke. The placement of the flare point directly affects the magnitude of the magnetic field produced to write information on the recording medium. Since magnetic flux decays as it travels down the length of the narrow second pole tip, shortening the second pole tip will increase the flux reaching the recording media. Therefore, performance can be optimized by aggressively placing the flare point close to the ABS. FIG. 1 illustrates, schematically, a conventional recording medium such as used with conventional magnetic disc recording systems. This medium is utilized for recording magnetic impulses in or parallel to the plane of the medium itself. The recording medium, a recording disc in this instance, comprises basically a supporting substrate 100 of a suitable non-magnetic material such as glass, with an overlying coating 102 of a suitable and conventional magnetic layer. FIG. 2 shows the operative relationship between a conventional recording/playback head 104, which may preferably be a thin film head, and a conventional recording medium, such as that of FIG. 1. FIG. 3 illustrates schematically the orientation of magnetic impulses substantially perpendicular to the surface of the recording medium. For such perpendicular recording the medium includes an under layer 302 of a material having a high magnetic permeability. This under layer 302 is then provided with an overlying coating 304 of magnetic material preferably having a high coercivity relative to the under layer 302. Two embodiments of storage systems with perpendicular heads 300 are illustrated in FIGS. 3 and 4 (not drawn to scale). The recording medium illustrated in FIG. 4 includes both the high permeability under layer 302 and the overlying coating 304 of magnetic material described with respect to FIG. 3 above. However, both of these layers 302 and 304 are shown applied to a suitable substrate 306. By this structure the magnetic lines of flux extending between the poles of the recording head loop into and out of the outer surface of the recording medium coating with the high permeability under layer of the recording medium causing the lines of flux to pass through the coating in a direction generally perpendicular to the surface of the medium to record information in the magnetically hard coating of the medium in the form of magnetic impulses having their axes of magnetization substantially perpendicular to the surface of the medium. The flux is channeled by the soft underlying coating 302 back to the return layer (P1) of the head 300. FIG. 5 illustrates a similar structure in which the substrate 306 carries the layers 302 and 304 on each of its two opposed sides, with suitable recording heads 300 positioned adjacent the outer surface of the magnetic coating 304 on each side of the medium. As perpendicular heads become smaller to accommodate ever increasing data density, fabrication processes must be adapted to properly create the fragile structures that will ultimately form the head. Current fabrication methods are not capable of adequately and consistently forming pole tips to the scale and tolerances required for modern disk drives. One proposed process uses a patterned photoresist mask 602 formed above a pole tip layer of magnetic material 604 and a layer of nonmagnetic material 606 such as Al2O3. The structure 600 is shown in FIG. 6. The structure 600 is milled to form the pole tip from the layer of magnetic material 604. The resulting structure 700 is shown in FIG. 7. While the process forms a pole tip 702 with the desired tapered cross-section, there are several disadvantages. First, this process does not scale easily below 0.25 μm, which is necessary for high data density drives. Second, the resist 602 does not have an acceptable mill resistance, i.e., too much of the mask 602 is consumed in the mill process. The result is that the pole tip is sometimes damaged by the milling. Third, removal of the resist 602 is necessary at the pole tip 702 without knocking over or destroying the pole tip 702. However, milling inherently produces redeposition 704, which tends to form on the sides of the resist 602, and may even encapsulate the resist. This redeposition makes removal of the resist 602 more difficult, as solvent has a harder time reaching the resist-pole tip interface. If any resist 602 remains coupled to the pole tip 702, attempted removal of the resist 602 tends to tip the pole tip 702 over. Further, some of the resist 602 may be entirely encapsulated by the redeposition. This is unacceptable, as having a layer of soft polymer (resist) at the ABS causes hard disk drive tribology issues, i.e., head-disk interface problems such as wear, water uptake, swelling, etc. Rather, it is desirable to have only hard materials at the ABS. Another proposed process uses an alumina hard mask layer 802 above a pole tip layer 804. Instead of photoresist, a layer of NiFe (nonmagnetic) 806 is plated on top of the hard mask layer 802 and trimmed and notched to form the structure 800 shown in FIG. 8. Then, the structure 800 is milled to form the pole tip 902, as shown in FIG. 9. This process avoids having to remove photoresist, but the extended milling required to mill through the layer of NiFe 806 and alumina hard mask layer 802 create cavities adjacent to the pole tip 902. Thus, the desired tapered shape of the pole tip 902 is difficult to achieve. Further, if further processing is to be performed above the pole tip 902, the layer of NiFe 806 and possibly the alumina hard mask layer 802 may need to be removed to reduce the overall head size and provide a smooth surface upon which to add the additional layers. Removal of these layers without damaging the pole tip 902 is difficult. What is needed is a method of fabricating pole tips of very small scale while overcoming the aforementioned disadvantages. SUMMARY OF THE INVENTION The present invention overcomes the disadvantages described above by providing a method of patterning standard and thin film magnetic structures, and that is particularly adapted to perpendicular heads. A method for forming a magnetic structure, such as a pole tip, includes forming a layer of magnetic material, hereinafter referred to as a pole tip layer. A layer of polyimide precursor material is added above the pole tip layer. The polyimide precursor material is cured to convert at least a substantial portion of the polyimide precursor material to at least one of a polyimide and a polyimide-like material. A silicon-containing resist layer is added above the layer of polyimide precursor material. The resist layer is patterned. The resist layer is also exposed to oxygen plasma for converting the resist into a glass-like material. Exposed portions of the cured polyimide precursor material are removed for exposing portions of the pole tip layer for defining a width of the pole tip. The exposed portions of the pole tip layer are removed for forming a pole tip. Chemical mechanical polishing (CMP) can then be performed to remove any unwanted material remaining above the pole tip. The exposed portions of the cured polyimide precursor material can be removed by reactive ion etching. The exposed portions of the cured polyimide precursor material can be removed by reactive ion etching with an oxygen-containing plasma. The exposed portions of the pole tip layer can be removed by milling. Several optional layers can be added. A first layer of material resistant to chemical mechanical polishing can be added above the pole tip layer to protect the pole tip during the CMP. A layer of nonmagnetic material can be added for substantially encapsulating the pole tip for reducing the tendency of the pole tip to tip over during CMP. Also, a second layer of material resistant to chemical mechanical polishing can be added above the layer of nonmagnetic material to further protect the pole tip from CMP damage. Additional options include alteration of the mask layer where the mask layer contains a layer that is etch resistant to an oxygen-containing plasma. This may include a hard etch mask that is patterned in a separate process. Using the methods described herein, pole tips and other structures having a width of less than 70 nm can be successfully created. One such pole tip is a perpendicular pole tip structure, comprising a pole tip layer of magnetic material having a top surface, a bottom surface, and sides extending between the top and bottom surface. Layers of non-magnetic materials surround the layer of magnetic material towards the sides of the pole tip layer. Interface layers are positioned above the non-magnetic material, portions of the interface layers lying along a plane substantially parallel to the top surface of the pole tip layer. Portions of the interface layers taper towards the pole tip layer at a slope that is from about one to about five times a thickness of the pole tip layer, where the thickness of the pole tip layer is defined between the top and bottom surfaces thereof. In one embodiment, each of the interface layers includes a layer of chemical mechanical polishing resistant material. In another embodiment, a layer of chemical mechanical polishing resistant material is positioned above the top surface of the pole tip layer. Other aspects and advantages of the present invention will become apparent from the following detailed description, which, when taken in conjunction with the drawings, illustrate by way of example the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of the nature and advantages of the present invention, as well as the preferred mode of use, reference should be made to the following detailed description read in conjunction with the accompanying drawings. FIG. 1 is a schematic representation in section of a recording medium utilizing a longitudinal recording format. FIG. 2 is a schematic representation of a conventional magnetic recording head and recording medium combination for longitudinal recording as in FIG. 1. FIG. 3 is a magnetic recording medium utilizing a perpendicular recording format. FIG. 4 is a schematic representation of a recording head and recording medium combination for perpendicular recording on one side. FIG. 5 is a schematic representation of the recording apparatus of the present invention, similar to that of FIG. 4, but adapted for recording separately on both sides of the medium. FIG. 6 is an ABS view of a structure to be formed into a pole tip according to a known process. FIG. 7 is an ABS view of the structure of FIG. 6 upon milling. FIG. 8 is an ABS view of a structure to be formed into a pole tip according to a known process. FIG. 9 is an ABS view of the structure of FIG. 8 upon milling. FIG. 10 is a simplified drawing of a magnetic recording disk drive system. FIG. 11 is an ABS view of a magnetic structure, not to scale, being formed according to one embodiment of the present invention. FIG. 12 is an ABS view of the magnetic structure of FIG. 11, not to scale, upon further processing. FIG. 13 is an ABS view of the magnetic structure of FIG. 12, not to scale, upon further processing. FIG. 14 is an ABS view of the magnetic structure of FIG. 13, not to scale, upon further processing. FIG. 15 is an ABS view of the magnetic structure of FIG. 14, not to scale, upon further processing. FIG. 16 is an ABS view of the magnetic structure of FIG. 15, not to scale, upon further processing. FIG. 17 is an ABS view of a magnetic structure, not to scale, being formed according to one embodiment of the present invention. FIG. 18 is an ABS view of the magnetic structure of FIG. 17, not to scale, upon further processing. FIG. 19 is an ABS view of the magnetic structure of FIG. 18, not to scale, upon further processing. FIG. 20 is an ABS view of the magnetic structure of FIG. 19, not to scale, upon further processing. FIG. 21 is an ABS view of the magnetic structure of FIG. 20, not to scale, upon further processing. FIG. 22 is an ABS view of the magnetic structure of FIG. 21, not to scale, upon further processing. FIG. 23 is a chart of experimental data showing actual track widths of pole tips formed by the process described above vs. target track widths. BEST MODE FOR CARRYING OUT THE INVENTION The following description is the best embodiment presently contemplated for carrying out the present invention. This description is made for the purpose of illustrating the general principles of the present invention and is not meant to limit the inventive concepts claimed herein. Referring now to FIG. 10, there is shown a disk drive 1000 embodying the present invention. As shown in FIG. 10, at least one rotatable magnetic disk 1012 is supported on a spindle 1014 and rotated by a disk drive motor 1018. The magnetic recording on each disk is in the form of an annular pattern of concentric data tracks (not shown) on the disk 1012. At least one slider 1013 is positioned near the disk 1012, each slider 1013 supporting one or more magnetic read/write heads 1021. More information regarding such heads 1021 will be set forth hereinafter during reference to the remaining FIGS. As the disks rotate, slider 1013 is moved radially in and out over disk surface 1022 so that heads 1021 may access different tracks of the disk where desired data are recorded. Each slider 1013 is attached to an actuator arm 1019 by way of a suspension 1015. The suspension 1015 provides a slight spring force which biases slider 1013 against the disk surface 1022. Each actuator arm 1019 is attached to an actuator means 1027. The actuator means 1027 as shown in FIG. 10 may be a voice coil motor (VCM). The VCM comprises a coil movable within a fixed magnetic field, the direction and speed of the coil movements being controlled by the motor current signals supplied by controller 1029. During operation of the disk storage system, the rotation of disk 1012 generates an air bearing between slider 1013 and disk surface 1022 which exerts an upward force or lift on the slider. The air bearing thus counter-balances the slight spring force of suspension 1015 and supports slider 1013 off and slightly above the disk surface by a small, substantially constant spacing during normal operation. The various components of the disk storage system are controlled in operation by control signals generated by control unit 1029, such as access control signals and internal clock signals. Typically, control unit 1029 comprises logic control circuits, storage means and a microprocessor. The control unit 1029 generates control signals to control various system operations such as drive motor control signals on line 1023 and head position and seek control signals on line 1028. The control signals on line 1028 provide the desired current profiles to optimally move and position slider 1013 to the desired data track on disk 1012. Read and write signals are communicated to and from read/write heads 1021 by way of recording channel 1025. The above description of a typical magnetic disk storage system, and the accompanying illustration of FIG. 10 are for representation purposes only. It should be apparent that disk storage systems may contain a large number of disks and actuators, and each actuator may support a number of sliders. FIG. 11 is an ABS view of a structure 1100 formed during a process for forming a magnetic structure such as a perpendicular pole tip. For clarity and ease of understanding, the following description shall refer to creation of a pole tip, it being understood by one skilled in the art that the processes can be adapted with little or no modification to form magnetic structures for various uses. It is also assumed that one can form additional poles and coil layers at different points in the process. As shown in FIG. 11, a magnetic pole tip layer 1102 is formed on a layer of nonmagnetic material 1104 such as Al2O3. The pole tip layer 1102 can be formed of any suitable magnetic material including NiFe, CoFe, laminates, etc. As depicted in FIG. 12, a layer of a polyimide precursor polymer 1202 is spun onto the structure of FIG. 11. A preferred polyimide precursor polymer is DURIMIDE®, sold by Arch Chemicals Inc., 501 Merritt 7, P.O. Box 5204, Norwalk, Conn., 06856-5204, USA. Note that instead of a polyimide precursor polymer, other material that upon curing (e.g., baking) forms a material that is polyimide-like may also be used. For clarity, the remaining discussion shall refer to a polyimide precursor polymer, it being understood that this term includes polymers capable of forming polyimides and polyimide-like materials. The polyimide precursor polymer 1202 is hard baked to cure the polymer 1202, forming the polyimide or polyimide-like material. Referring to FIG. 13, to form the desired shape of the cured polyimide precursor polymer 1202, a silicon-containing resist layer 1302 is added and patterned to allow patterning of the cured polyimide precursor polymer 1202. Photo-exposable or electron beam exposable Si-containing resists may be used. A preferred Si-containing resist is an e-beam resist such as hydrogen silsesquioxane (HSQ), sold by Dow Corning Corporation, Corporate Center, PO box 994, Midland, Mich., 48686-0994, USA. FIG. 14 is a top down depiction of the structure of FIG. 13. As shown, the e-beam exposes an anchor pad 1402, a line (pole) 1404, and another anchor pad 1406. The anchor pads 1402, 1406 add stability to the pole 1404 so that it is less likely to tip over during subsequent processing. In addition, the exposed surface (i.e., ABS) of the slider 1409 should coincide with the pole. The Si-containing resist 1302 is exposed to an oxygen plasma, which converts the resist 1302 to a material that is like glass, e.g., SiOx. The SiOx mask is then used as a hard mask to RIE with an oxygen-containing plasma (e.g., CO2 plasma) to form the polyimide stack, as shown in FIG. 15. In general terms, the resulting structure is a patterned polyimide layer and a Si-containing mask on top of a polyimide layer. The structure of FIG. 15 is milled, such as by ion beam milling, to remove the exposed portions of the pole tip layer 1102, thereby forming the pole tip 1502. The resulting structure is shown in FIG. 16. Subsequent processing, described in more detail below, is used to remove the polyimide layer and any remaining resist. Note that in the above process, as well as in the subsequently discussed processes, additional layers may be added to the structures if desired. In a preferred process, a pole tip layer 1102 is formed on a layer of nonmagnetic material 1104 as above. As shown in FIG. 17, the pole tip layer 1102 is coated with a first chemical mechanical polishing (CMP)-resistant layer 1702 prior to addition of the polyimide precursor polymer 1202. The CMP-resistant layer 1702 is hard such that it is more resistant to removal by CMP than other surrounding materials. The CMP-resistant layer 1702 is preferably formed of diamond-like carbon (DLC) of a thickness greater than about 50 Å, and ideally in the range of about 100-1000 Å. A thin layer of an adhesive (not shown) can be added to the pole tip layer 1102 prior to coating with the CMP resistant layer to aid in adhering the CMP-resistant layer 1702 to the pole tip layer 1102. For example a layer of Si-containing adhesive having a thickness of about 5-20 Å can be used. Then, the polyimide precursor polymer 1202 and Si-containing resist 1302 are formed, cured and patterned as described above, resulting in the structure shown in FIG. 18. The structure of FIG. 18 is milled to define the pole tip 1802, which is shown in FIG. 19. The actual milling process will vary depending on the type of tool selected, gas used, ion energies, etc. The mill pattern may also vary. For example, the wafer can be rotated in one direction, sweep milling (oscillating rotation) can be performed, etc. Preferably the milling is performed at alternating mill angles of less than 25 degrees from normal to remove the exposed portions of the pole tip layer 1102 and greater than 50 degrees from normal to remove redeposition, where normal is defined as perpendicular to the plane of the layers of materials and parallel to the ABS. The structure is preferably milled such that the pole tip 1802 has a certain amount of beveling to form a trapezoidal shape. The trapezoidal shape reduces the likelihood of writing to adjacent tracks, translating into a lower error rate. The inventors have found that alternating milling at about 10 degrees and at about 70 degrees from normal provide a beveled pole tip 1802 without substantial amounts of redeposition. As shown in FIG. 20, after milling, the entire surface is coated with a nonmagnetic material 2002, preferably alumina (e.g., AlOx), by full film deposition. The entire thickness of the alumina layer 2002 is preferably about as thick as or thicker than the thickness of the pole tip 1802. Making the alumina layer 2002 as thick as or thicker than the pole tip 1802 prevents the pole tip 1802 from delaminating from its underlayer and/or tipping over during later CMP, as well as aiding in the prevention of CMP damage to the pole tip 1802 itself. The thickness of alumina refill 2002 is preferably in the range of about 100-500% the thickness of the pole tip 1802. More than 500% can result in the subsequent CMP not being able to remove enough material to expose the resist to solvent. On top of the AlOx fill, a second CMP-resistant layer 2102 (e.g., DLC), or interface layer, is deposited full film onto the structure, as depicted in FIG. 21. The thickness of the second CMP-resistant layer 2102 may or may not be the same as that of the first CMP-resistant layer 1702. A preferred thickness of the second CMP-resistant layer 2102 should be greater than about 50 Å, and is ideally in the range of about 100-1000 Å. The upper surface of the second CMP-resistant layer 2102 is preferably located at or above the plane of the upper surface of the pole tip 1802 to prevent the pole tip 1802 from delaminating from its underlayer and/or tipping over during later CMP, as well as aiding in the prevention of CMP of the pole tip 1802 itself. The structure shown in FIG. 21 is polished such as by CMP to create the structure shown in FIG. 22. The amount of polishing is important, as it is desirable to avoid any CMP of the pole tip material to avoid damage to the pole tip 1802, which could result in the pole tip 1802 having a variable track width. However, too little CMP may result in not breaking open the anchor pad to allow solvent to reach the remaining polyimide-like layer 1202. Also, some of the resist may remain encapsulated by material redeposited during the milling. Too much CMP may result in damaging the pole tip 1802. Thus, the structure is preferably polished down to or into the first CMP-resistant layer 1702, but not remove the layer 1702. The preferred CMP process is very gentle. In one embodiment, the wafer is rotated one or more times for a duration of less than about a minute, and preferably less than 30 seconds, under the CMP pad at a pressure of less than about 5 psi and in a nonreactive slurry (e.g., a slurry that does not readily etch the pole tip material) such as CABO-SPERSE® SCI available from Cabot Microelectronics, 870 N. Commons Drive, Aurora, Ill. 60504, USA. Solvent is applied to remove any remaining resist exposed by the CMP. The carbons can be removed with an oxygen plasma, leaving an essentially (but not necessarily perfectly) coplanar surface of alumina 2002, the pole tip 1802 (e.g., NiFe), and alumina 2002. Because the alumina refill 2002 is thicker than the pole tip 1802, portions of the alumina refill 2002 adjacent the pole tip will tend to taper towards the pole tip 1802 at a slope that is from about one to about five times a thickness of the pole tip 1802 after the polish process. FIG. 22 also shows that the completed pole tip contains a transition length 2202 consisting of the non-magnetic material 1202. It should also be noted that it is likely that the plane 2208 defined substantially away from the pole will ideally be inside the field CMP-resistant layer 2102. This plane 2208 will be slightly higher than the plane 2222 defined by the top surface of the pole tip 1102. Therefore, it is not unexpected that this creates a transition 2202 between the two aforementioned planes 2208, 2222. Additional layers can then be added for forming additional portions of the structure. Because the upper surface of the formed structure is essentially flat, the additional layers will be more easily formed. The process described herein has been used to form pole tips of about 69 nm wide, and can be used to form pole tips of even smaller widths. EXAMPLES FIG. 23 is a chart 2300 of experimental data showing actual track widths of pole tips formed by the process described above vs. target track widths. As shown, the actual track widths are nearly on target. For example, when the target track width created in the hard mask layer 1302 was 150 nm, the actual track width was about 160 nm. When the target track width was 100 nm, the actual track width was about 100 nm (±10%). What is also mentioned in FIG. 23 is various thicknesses of a “clean up” mill. This simply was to illustrate that the mill time at high angle (to remove redeposition from the milling) influences the track width and the amount of bevel angle that is found in the final pole tip 1102. The “clean up” mill of longer time is equivalent of removing greater amounts of NiFe. While various embodiments have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of a preferred embodiment should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. | <SOH> BACKGROUND OF THE INVENTION <EOH>In a typical head, an inductive write head includes a coil layer embedded in first, second and third insulation layers (insulation stack), the insulation stack being located between first and second pole piece layers. A gap is formed between the first and second pole piece layers by a gap layer at an air bearing surface (ABS) of the write head. The pole piece layers are connected at a back gap. Currents are conducted through the coil layer, which produce magnetic fields in the pole pieces. The magnetic fields fringe across the gap at the ABS for the purpose of writing bits of magnetic field information in tracks on moving media, such as in circular tracks on a rotating magnetic disk or longitudinal tracks on a moving magnetic tape. The second pole piece layer has a pole tip portion which extends from the ABS to a flare point and a yoke portion which extends from the flare point to the back gap. The flare point is where the second pole piece begins to widen (flare) to form the yoke. The placement of the flare point directly affects the magnitude of the magnetic field produced to write information on the recording medium. Since magnetic flux decays as it travels down the length of the narrow second pole tip, shortening the second pole tip will increase the flux reaching the recording media. Therefore, performance can be optimized by aggressively placing the flare point close to the ABS. FIG. 1 illustrates, schematically, a conventional recording medium such as used with conventional magnetic disc recording systems. This medium is utilized for recording magnetic impulses in or parallel to the plane of the medium itself. The recording medium, a recording disc in this instance, comprises basically a supporting substrate 100 of a suitable non-magnetic material such as glass, with an overlying coating 102 of a suitable and conventional magnetic layer. FIG. 2 shows the operative relationship between a conventional recording/playback head 104 , which may preferably be a thin film head, and a conventional recording medium, such as that of FIG. 1 . FIG. 3 illustrates schematically the orientation of magnetic impulses substantially perpendicular to the surface of the recording medium. For such perpendicular recording the medium includes an under layer 302 of a material having a high magnetic permeability. This under layer 302 is then provided with an overlying coating 304 of magnetic material preferably having a high coercivity relative to the under layer 302 . Two embodiments of storage systems with perpendicular heads 300 are illustrated in FIGS. 3 and 4 (not drawn to scale). The recording medium illustrated in FIG. 4 includes both the high permeability under layer 302 and the overlying coating 304 of magnetic material described with respect to FIG. 3 above. However, both of these layers 302 and 304 are shown applied to a suitable substrate 306 . By this structure the magnetic lines of flux extending between the poles of the recording head loop into and out of the outer surface of the recording medium coating with the high permeability under layer of the recording medium causing the lines of flux to pass through the coating in a direction generally perpendicular to the surface of the medium to record information in the magnetically hard coating of the medium in the form of magnetic impulses having their axes of magnetization substantially perpendicular to the surface of the medium. The flux is channeled by the soft underlying coating 302 back to the return layer (P 1 ) of the head 300 . FIG. 5 illustrates a similar structure in which the substrate 306 carries the layers 302 and 304 on each of its two opposed sides, with suitable recording heads 300 positioned adjacent the outer surface of the magnetic coating 304 on each side of the medium. As perpendicular heads become smaller to accommodate ever increasing data density, fabrication processes must be adapted to properly create the fragile structures that will ultimately form the head. Current fabrication methods are not capable of adequately and consistently forming pole tips to the scale and tolerances required for modern disk drives. One proposed process uses a patterned photoresist mask 602 formed above a pole tip layer of magnetic material 604 and a layer of nonmagnetic material 606 such as Al 2 O 3 . The structure 600 is shown in FIG. 6 . The structure 600 is milled to form the pole tip from the layer of magnetic material 604 . The resulting structure 700 is shown in FIG. 7 . While the process forms a pole tip 702 with the desired tapered cross-section, there are several disadvantages. First, this process does not scale easily below 0.25 μm, which is necessary for high data density drives. Second, the resist 602 does not have an acceptable mill resistance, i.e., too much of the mask 602 is consumed in the mill process. The result is that the pole tip is sometimes damaged by the milling. Third, removal of the resist 602 is necessary at the pole tip 702 without knocking over or destroying the pole tip 702 . However, milling inherently produces redeposition 704 , which tends to form on the sides of the resist 602 , and may even encapsulate the resist. This redeposition makes removal of the resist 602 more difficult, as solvent has a harder time reaching the resist-pole tip interface. If any resist 602 remains coupled to the pole tip 702 , attempted removal of the resist 602 tends to tip the pole tip 702 over. Further, some of the resist 602 may be entirely encapsulated by the redeposition. This is unacceptable, as having a layer of soft polymer (resist) at the ABS causes hard disk drive tribology issues, i.e., head-disk interface problems such as wear, water uptake, swelling, etc. Rather, it is desirable to have only hard materials at the ABS. Another proposed process uses an alumina hard mask layer 802 above a pole tip layer 804 . Instead of photoresist, a layer of NiFe (nonmagnetic) 806 is plated on top of the hard mask layer 802 and trimmed and notched to form the structure 800 shown in FIG. 8 . Then, the structure 800 is milled to form the pole tip 902 , as shown in FIG. 9 . This process avoids having to remove photoresist, but the extended milling required to mill through the layer of NiFe 806 and alumina hard mask layer 802 create cavities adjacent to the pole tip 902 . Thus, the desired tapered shape of the pole tip 902 is difficult to achieve. Further, if further processing is to be performed above the pole tip 902 , the layer of NiFe 806 and possibly the alumina hard mask layer 802 may need to be removed to reduce the overall head size and provide a smooth surface upon which to add the additional layers. Removal of these layers without damaging the pole tip 902 is difficult. What is needed is a method of fabricating pole tips of very small scale while overcoming the aforementioned disadvantages. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention overcomes the disadvantages described above by providing a method of patterning standard and thin film magnetic structures, and that is particularly adapted to perpendicular heads. A method for forming a magnetic structure, such as a pole tip, includes forming a layer of magnetic material, hereinafter referred to as a pole tip layer. A layer of polyimide precursor material is added above the pole tip layer. The polyimide precursor material is cured to convert at least a substantial portion of the polyimide precursor material to at least one of a polyimide and a polyimide-like material. A silicon-containing resist layer is added above the layer of polyimide precursor material. The resist layer is patterned. The resist layer is also exposed to oxygen plasma for converting the resist into a glass-like material. Exposed portions of the cured polyimide precursor material are removed for exposing portions of the pole tip layer for defining a width of the pole tip. The exposed portions of the pole tip layer are removed for forming a pole tip. Chemical mechanical polishing (CMP) can then be performed to remove any unwanted material remaining above the pole tip. The exposed portions of the cured polyimide precursor material can be removed by reactive ion etching. The exposed portions of the cured polyimide precursor material can be removed by reactive ion etching with an oxygen-containing plasma. The exposed portions of the pole tip layer can be removed by milling. Several optional layers can be added. A first layer of material resistant to chemical mechanical polishing can be added above the pole tip layer to protect the pole tip during the CMP. A layer of nonmagnetic material can be added for substantially encapsulating the pole tip for reducing the tendency of the pole tip to tip over during CMP. Also, a second layer of material resistant to chemical mechanical polishing can be added above the layer of nonmagnetic material to further protect the pole tip from CMP damage. Additional options include alteration of the mask layer where the mask layer contains a layer that is etch resistant to an oxygen-containing plasma. This may include a hard etch mask that is patterned in a separate process. Using the methods described herein, pole tips and other structures having a width of less than 70 nm can be successfully created. One such pole tip is a perpendicular pole tip structure, comprising a pole tip layer of magnetic material having a top surface, a bottom surface, and sides extending between the top and bottom surface. Layers of non-magnetic materials surround the layer of magnetic material towards the sides of the pole tip layer. Interface layers are positioned above the non-magnetic material, portions of the interface layers lying along a plane substantially parallel to the top surface of the pole tip layer. Portions of the interface layers taper towards the pole tip layer at a slope that is from about one to about five times a thickness of the pole tip layer, where the thickness of the pole tip layer is defined between the top and bottom surfaces thereof. In one embodiment, each of the interface layers includes a layer of chemical mechanical polishing resistant material. In another embodiment, a layer of chemical mechanical polishing resistant material is positioned above the top surface of the pole tip layer. Other aspects and advantages of the present invention will become apparent from the following detailed description, which, when taken in conjunction with the drawings, illustrate by way of example the principles of the invention. | 20040223 | 20061121 | 20050825 | 77448.0 | 0 | HEINZ, ALLEN J | MAGNETIC POLE TIP FOR PERPENDICULAR MAGNETIC RECORDING | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,785,697 | ACCEPTED | Volumetric imaging using "virtual'' lenslets | A system constructs an image using virtual lenslets. | 1. A method comprising: capturing a primary image representation with a photo-detector array at a primary position; associating a primary set of discrete portions of the primary image representation with one or more defined virtual lenslets of a lens; moving the photo-detector array to another position; capturing another image representation with the photo-detector array at the other position; associating another set of discrete portions of the other image representation with the one or more defined virtual lenslets of the lens; and assembling a volumetric image from those virtual lenslet associated portions of the primary and the other image representation that have relatively sharper focuses. 2. The method of claim 1, wherein said capturing a primary image representation with a photo-detector array at a primary position further comprises: extracting at least one of a red, blue, or green color component of the primary image. 3. The method of claim 2, wherein said extracting at least one of a red, blue, or green color component of the primary image further comprises: numerically filtering the primary image. 4. The method of claim 1, wherein said associating a primary set of discrete portions of the primary image representation with one or more defined virtual lenslets of a lens further comprises: obtaining one or more projections of the one or more defined virtual lenslets through a geometric surface in 3-space corresponding to an imaging surface of the photo-detector array at the primary position. 5. The method of claim 4, wherein said obtaining one or more projections of the one or more defined virtual lenslets through a geometric surface in 3-space corresponding to an imaging surface of the photo-detector array at the primary position further comprises: defining one or more geometric shapes at a predefined position of a lens; and calculating a projection of the one or more defined geometric shapes to the geometric surface in 3-space corresponding to an imaging surface of the photo-detector array at the primary position. 6. The method of claim 1, wherein said moving the photo-detector array to another position further comprises: tilting the CCD detector array about a defined axis of tilt. 7. The method of claim 6, wherein said tilting the CCD detector array about a defined axis of tilt further comprises: tilting a portion of the photo-detector array forward of the defined axis of tilt. 8. The method of claim 6, wherein said tilting the CCD detector array about a defined axis of tilt further comprises: tilting a portion of the photo-detector array rearward of the defined axis of tilt. 9. The method of claim 1, wherein said moving the photo-detector array to another position further comprises: rotating the photo-detector array about a defined axis of rotation. 10. The method of claim 1, wherein said capturing another image representation with the photo-detector array at the other position further comprises: extracting at least one of a red, blue, or green color component of the other image. 11. The method of claim 10, wherein said extracting at least one of a red, blue, or green color component of the other image further comprises: numerically filtering the other image. 12. The method of claim 1, wherein said associating another set of discrete portions of the other image representation with the one or more defined virtual lenslets of the lens further comprises: obtaining one or more projections of the one or more defined virtual lenslets through a geometric surface in 3-space corresponding to an imaging surface of the photo-detector array at the other position. 13. The method of claim 12, wherein said obtaining one or more projections of the one or more defined virtual lenslets through a geometric surface in 3-space corresponding to an imaging surface of the photo-detector array at the other position further comprises: defining one or more geometric shapes at a predefined position of a lens; and calculating a projection of the one or more defined geometric shapes to the geometric surface in 3-space corresponding to an imaging surface of the photo-detector array at the other position. 14. The method of claim 1, wherein said assembling a volumetric image from those virtual lenslet associated portions of the primary and the other image representation that have relatively sharper focuses further comprises: determining an image score for each of the lenslet-associated portions; and storing the image score. 15. The method of claim 14, wherein said determining an image score for each of the lenslet-associated portions further comprises: calculating a Fourier transform of each of the lenslet associated portions. 16. The method of claim 1, wherein said assembling a volumetric image from those virtual lenslet associated portions of the primary and the other image representation that have relatively sharper focuses further comprises: correlating a feature of the primary image with a feature of the other image; detecting at least one of size, color, or displacement deviation of at least one of the primary image or the other image; correcting the detected at least one of size, color, or displacement deviation of the at least one of the primary image or the other image; and assembling the composite image using the corrected deviation. 17. The method of claim 1, wherein said assembling a volumetric image from those virtual lenslet associated portions of the primary and the other image representation that have relatively sharper focuses further comprises: correlating a feature of a virtual lenslet of the primary image with a feature of a virtual lenslet of the other image; detecting at least one of size, color, or displacement deviation of at least one virtual lenslet of the primary image or at least one virtual lenslet of the other image; correcting the detected at least one of size, color, or displacement deviation of the at least one virtual lenslet of the primary image or the at least one virtual lenslet of the other image; and assembling the composite image using the corrected deviation. 18. A system comprising: means for capturing a primary image representation with a photo-detector array at a primary position; means for associating a primary set of discrete portions of the primary image representation with one or more defined virtual lenslets of a lens; means for moving the photo-detector array to another position; means for capturing another image representation with the photo-detector array at the other position; means for associating another set of discrete portions of the other image representation with the one or more defined virtual lenslets of the lens; and means for assembling a volumetric image from those virtual lenslet associated portions of the primary and the other image representations that have relatively sharper focuses. 19. The system of claim 18, wherein said means for capturing a primary image representation with a photo-detector array at a primary position further comprises: means for extracting at least one of a red, blue, or green color component of the primary image. 20. The system of claim 19, wherein said means for extracting at least one of a red, blue, or green color component of the primary image further comprises: means for numerically filtering the primary image. 21. The system of claim 18, wherein said means for associating a primary set of discrete portions of the primary image representation with one or more defined virtual lenslets of a lens further comprises: means for obtaining one or more projections of the one or more defined virtual lenslets through a geometric surface in 3-space corresponding to an imaging surface of the photo-detector array at the primary position. 22. The system of claim 21, wherein said means for obtaining one or more projections of the one or more defined virtual lenslets through a geometric surface in 3-space corresponding to an imaging surface of the photo-detector array at the primary position further comprises: means for defining one or more geometric shapes at a predefined position of a lens; and means for calculating a projection of the one or more defined geometric shapes to the geometric surface in 3-space corresponding to an imaging surface of the photo-detector array at the primary position. 23. The system of claim 18, wherein said means for moving the photo-detector array to another position further comprises: means for tilting the CCD detector array about a defined axis of tilt. 24. The system of claim 23, wherein said means for tilting the CCD detector array about a defined axis of tilt further comprises: means for tilting a portion of the photo-detector array forward of the defined axis of tilt. 25. The system of claim 23, wherein said means for tilting the CCD detector array about a defined axis of tilt further comprises: means for tilting a portion of the photo-detector array rearward of the defined axis of tilt. 26. The system of claim 18, wherein said means for moving the photo-detector array to another position further comprises: means for rotating the photo-detector array about a defined axis of rotation. 27. The system of claim 18, wherein said means for capturing another image representation with the photo-detector array at the other position further comprises: means for extracting at least one of a red, blue, or green color component of the other image. 28. The system of claim 27, wherein said means for extracting at least one of a red, blue, or green color component of the other image further comprises: means for numerically filtering the other image. 29. The system of claim 18, wherein said means for associating another set of discrete portions of the other image representation with the one or more defined virtual lenslets of the lens further comprises: means for obtaining one or more projections of the one or more defined virtual lenslets through a geometric surface in 3-space corresponding to an imaging surface of the photo-detector array at the other position. 30. The system of claim 29, wherein said means for obtaining one or more projections of the one or more defined virtual lenslets through a geometric surface in 3-space corresponding to an imaging surface of the photo-detector array at the other position further comprises: means for defining one or more geometric shapes at a predefined position of a lens; and means for calculating a projection of the one or more defined geometric shapes to the geometric surface in 3-space corresponding to an imaging surface of the photo-detector array at the other position. 31. The system of claim 18, wherein said means for assembling a volumetric image from those virtual lenslet associated portions of the primary and the other image representations that have relatively sharper focuses further comprises: means for determining an image score for each of the lenslet associated portions; and means for storing the image score. 32. The system of claim 31, wherein said means for determining an image score for each of the lenslet associated portions further comprises: means for calculating a Fourier transform of each of the lenslet associated portions. 33. The system of claim 18, wherein said means for assembling a volumetric image from those virtual lenslet associated portions of the primary and the other image representations that have relatively sharper focuses further comprises: means for correlating a feature of the primary image with a feature of the other image; means for detecting at least one of size, color, or displacement deviation of at least one of the primary image and the other image; means for correcting the detected at least one of size, color, or displacement deviation of the at least one of the primary image or the other image; and means for assembling the composite image using the corrected deviation. 34. The system of claim 18, wherein said means for assembling a volumetric image from those virtual lenslet associated portions of the primary and the other image representations that have relatively sharper focuses further comprises: means for correlating a feature of a virtual lenslet of the primary image with a feature of a virtual lenslet of the other image; means for detecting at least one of size, color, or displacement deviation of at least one virtual lenslet of the primary image or at least one virtual lenslet of the other image; means for correcting the detected at least one of size, color, or displacement deviation of the at least one virtual lenslet of the primary image or the at least one virtual lenslet of the other image; and means for assembling the composite image using the corrected deviation. 35. A system comprising: a lens associated with one or more virtual lenslets; a controller configured to position a photo-detector array at a primary and another position; an image capture unit configured to capture a primary image at the primary position and another image at the other position; and a volumetric image construction unit configured to utilize at least a part of the one or more virtual lenslets in association with at least one of the primary image or the other image. 36. The system of claim 35, wherein said controller configured to position a photo-detector array at a primary and another position further comprises: a transducer system having a control signal input operably coupled with said controller and a motion output operably coupled with said photo-detector array. 37. The system of claim 36, wherein said transducer system further comprises an electric motor operably coupled to move said photo-detector array. 38. The system of claim 36, wherein said transducer system further comprises an electric motor operably coupled to distort said photo-detector array. 39. The system of claim 35, wherein said image capture unit configured to capture a primary image at the primary position and another image at the other position further comprises: circuitry for obtaining one or more projections of the one or more virtual lenslets through a geometric surface in 3-space corresponding to an imaging surface of the photo-detector array. 40. The system of claim 35, wherein said volumetric image construction unit configured to utilize at least a part of the one or more virtual lenslets in association with at least one of the primary image or the other image further comprises: circuitry for utilizing at least a part of the one or more virtual lenslets in association with at least one of the primary image or the other image said circuitry including at least one of electrical circuitry having at least one discrete electrical circuit, electrical circuitry having at least one integrated circuit, electrical circuitry having at least one application specific integrated circuit, electrical circuitry having a general purpose computing device configured by a computer program, electrical circuitry having a memory device, or electrical circuitry having a communications device. | TECHNICAL FIELD The present application relates, in general, to imaging. SUMMARY In one aspect, a method includes but is not limited to: capturing a primary image representation with a photo-detector array at a primary position; associating a primary set of discrete portions of the primary image representation with one or more defined virtual lenslets of a lens; moving the photo-detector array to another position; capturing another image representation with the photo-detector array at the other position; associating another set of discrete portions of the other image representation with the one or more defined virtual lenslets of the lens; and assembling a volumetric image from those virtual lenslet associated portions of the primary and the other image representation that have relatively sharper focuses. In addition to the foregoing, other method aspects are described in the claims, drawings, and text forming a part of the present application. In one or more various aspects, related systems include but are not limited to circuitry and/or programming for effecting the herein-referenced method aspects; the circuitry and/or programming can be virtually any combination of hardware, software, and/or firmware configured to effect the herein-referenced method aspects depending upon the design choices of the system designer. In one aspect, a system includes but is not limited to: capturing a primary image representation with a photo-detector array at a primary position; associating a primary set of discrete portions of the primary image representation with one or more defined virtual lenslets of a lens; moving the photo-detector array to another position; capturing another image representation with the photo-detector array at the other position; associating another set of discrete portions of the other image representation with the one or more defined virtual lenslets of the lens; and assembling a volumetric image from those virtual lenslet associated portions of the primary and the other image representations that have relatively sharper focuses. In addition to the foregoing, other system aspects are described in the claims, drawings, and text forming a part of the present application. In one aspect, a system includes but is not limited to: a lens associated with one or more virtual lenslets; a controller configured to position a photo-detector array at a primary and another position; an image capture unit configured to capture a primary image at the primary position and another image at the other position; and a volumetric image construction unit configured to utilize at least a part of the one or more virtual lenslets in association with at least one of the primary image and the other image. In addition to the foregoing, other system aspects are described in the claims, drawings, and text forming a part of the present application. In addition to the foregoing, various other method and/or system aspects are set forth and described in the text (e.g., claims and/or detailed description) and/or drawings of the present application. The foregoing is a summary and thus contains, by necessity, simplifications, generalizations and omissions of detail; consequently, those skilled in the art will appreciate that the summary is illustrative only and is NOT intended to be in any way limiting. Other aspects, inventive features, and advantages of the devices and/or processes described herein, as defined by the claims, will become apparent in the detailed description set forth herein. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 shows a front-plan view of tree image 104, person image 106, and bird image 108 projected onto photo-detector array 102 (e.g., through lens 204 of lens system 200 of FIG. 2). FIG. 2 depicts a side-plan view of lens system 200 that can give rise to tree image 104, person image 106, and bird image 108 of FIG. 1. FIG. 3 illustrates a perspective view of lens 204 positioned to focus light onto an imaging surface of photo-detector array 102. FIG. 4 shows the perspective view of FIG. 3 wherein exemplary virtual lenses are illustrated. FIG. 5 depicts the perspective view of FIG. 4 wherein projections of the exemplary virtual lenslets onto the imaging surface of photo-detector array 102 are illustrated. FIG. 6 depicts a high level logic flowchart of a process. Method step 600 shows the start of the process. FIGS. 7 and 8 depict partial perspective views of the system of FIG. 2 wherein photo-detector array 102 is being moved in accordance with aspects of processes shown and described herein (e.g., in relation to FIG. 6). FIG. 9 illustrates a perspective view of the system of FIG. 2 wherein photo-detector array 102 is being moved in accordance with aspects of the process shown and described herein (e.g., in relation to FIG. 6). The use of the same symbols in different drawings typically indicates similar or identical items. DETAILED DESCRIPTION With reference to the figures, and with reference now to FIG. 1, shown is a front-plan view of tree image 104, person image 106, and bird image 108 projected onto photo-detector array 102 (e.g., through lens 204 of lens system 200 of FIG. 2). Tree image 104 is illustrated as large and blurry, which can occur when an actual tree is positioned relative to a lens such that when the actual tree is projected through the lens tree image 104 comes to a focus in front of an imaging surface of photo-detector array 102 (e.g., actual tree 224 projected through lens 204 of FIG. 2). Person image 106 is illustrated as right sized, which can occur when an actual person is positioned relative to a lens such that when the actual person is projected through the lens person image 106 comes to a focus substantially on an imaging surface of photo-detector array 102 (e.g., actual person 226 projected through lens 204 of FIG. 2). Bird image 108 is shown as small and faint, which can occur when an actual bird is positioned relative to a lens such that when the actual bird is projected through the lens bird image 108 comes to a focus (virtual) behind an imaging surface of photo-detector array 102 (e.g., actual bird 228 projected through lens 204 of FIG. 2). In addition, although not expressly shown, those having skill in the art will appreciate that various lens defects could also cause the image to be distorted in x-y; those having skill in the art will also appreciate that different colored wavelengths of light can in and of themselves focus at different positions due to differences in refraction of the different colored wavelengths of light. Referring now to FIG. 2, depicted is a side-plan view of lens system 200 that can give rise to tree image 104, person image 106, and bird image 108 of FIG. 1. Lens 204 of lens system 200 is illustrated as located at a primary position that gives rise to tree image 104, person image 106, and bird image 108 of FIG. 1. Tree image 104 is illustrated as focused in front of an imaging surface of photo-detector array 102 as a consequence of actual tree 224's position relative to lens 204's focal length. Person image 106 is illustrated as right sized and focused on an imaging surface of photo-detector array 102 as a consequence of actual person 226's position relative to lens 204's focal length. (It is recognized that in side plan view the head and feet of actual person 226 would appear as lines; however, for sake of clarity, they are shown in profile in FIG. 2 to help orient the reader relative to FIG. 1.) Bird image 108 is shown as virtually focused behind an imaging surface of photo-detector array 102 as a consequence of actual bird 228's position relative to lens 204's focal length. Continuing to refer to FIG. 2, further shown are components that can serve as an environment for one or more processes shown and described herein. Specifically, controller 208 is depicted as controlling the position of photo-detector array 102 (e.g., via use of a feedback control subsystem). Image capture unit 206 is illustrated as receiving image data from photo-detector array 102 and receiving control signals from controller 208. Image capture unit 206 is shown as transmitting captured image information to focus detection unit 210. Focus detection unit 210 is depicted as transmitting focus data to volumetric image construction unit 212. Volumetric image construction unit 212 is illustrated as transmitting a composite image to image store/display unit 214. With reference now to FIG. 3, illustrated is a perspective view of lens 204 positioned to focus light onto an imaging surface of photo-detector array 102. The focused light is illustrated as projecting a geometric pattern 300 onto the imaging surface of photo-detector array 102 that is more or less the same shape as lens 204. Image 100 (e.g., FIGS. 1 and 2) is shown being projected within the confines of geometric pattern 300. As noted, the positions of actual tree 104, actual person 106, and actual bird 108 relative to the focal lengths of lens 204 give rise to tree image 104, person image 106, and bird image 108. The inventors have determined that the misfocused/distorted tree image 104, person image 106, and bird image 108 can be corrected by using a virtual lens technique. Referring now to FIG. 4, shown is the perspective view of FIG. 3 wherein exemplary virtual lenslets are illustrated. Lens 204 is depicted as having inscribed within it several small circles that may be conceived of as “virtual lenslets” 400. The term “virtual” is used herein to indicate that in most instances these virtual lenslets are conceptual overlays (e.g., mathematical constructs) onto at least a portion of the actual physical lens 204. In various implementations, the overlays are done mathematically and/or computationally. With reference now to FIG. 5, depicted is the perspective view of FIG. 4 wherein projections of the exemplary virtual lenslets onto the imaging surface of photo-detector array 102 are illustrated. Virtual lenslets 400 are shown as geometrically projected within the confines of geometric pattern 300 on the imaging surface of photo-detector array 102. In various implementations, the projections are done mathematically and/or computationally. As noted elsewhere herein, lens defects and/or other factors may give rise to z-axis misfocusing and/or x-y plane all or part of image 100. In one implementation, all or part of such z-axis distortion is corrected by using one or more virtual lenses in conjunction with tilting and/or rotation of photo-detector array 102. Referring now to FIG. 6, depicted is a high level logic flowchart of a process. Method step 600 shows the start of the process. Method step 601 depicts associating/generating virtual lenslets that overlay a lens at a known position. For example, for any particular lens, a pre-stored set of virtual lenses for such a particular lens might be recalled or might be calculated in near real-time. In some instances, the calculation is keyed to image requirements (e.g., higher resolution requirements would typically engender more virtual lenslets and lower resolution requirements would typically engender fewer virtual lenslets). Referring again to FIG. 2, one specific example of method step 601 (FIG. 6) would be image capture unit 206 recalling a set of mathematical functions defining virtual lenslets (e.g., virtual lenslets 400 of FIG. 4) from memory storage and thereafter fitting the recalled virtual lenslet mathematical functions onto/into a likewise recalled known mathematical geometry of lens 204 of FIGS. 2, 3, and 4. Another specific example of method step 601 (FIG. 6) would be image capture unit 206 calculating set of mathematical functions defining virtual lenslets (e.g., virtual lenslets 400 of FIG. 4) in response to user resolution requirements, and thereafter fitting the calculated virtual lenslet mathematical functions onto/into an either a measured, a calculated, or a recalled known mathematical geometry of lens 204 of FIGS. 2, 3, and 4. Method step 602 illustrates projecting the virtual lenslets through a volume of space that encompasses an imaging surface of a photo-detector at a known primary position (e.g., a mathematical projection onto an imaging surface of the photo-detector). Referring again to FIG. 2, one specific example of method step 602 (FIG. 6) would be image capture unit 206 obtaining from lens system 200's control system (not shown) positioning information of lens 204 and thereafter using that position information, in conjunction with the mapped virtual lenslets (e.g., method step 601), to mathematically project the virtual lenslets onto a known imaging surface primary position of photo-detector array 102. In one specific example, image capture unit 206 obtains the imaging surface primary position from controller 208. Method step 603 depicts capturing a primary image with a photo-detector array at a primary position. In one implementation, method step 603 includes the sub-step of capturing the primary image at an average primary focal surface location of a lens (e.g., a defined focal surface of the lens array where an image would form if the lens had no aberrations and/or defects outside certain specified tolerances) and associating portions of the captured image with the projections of the virtual lenslets. In another implementation, method step 603 includes the sub-step of capturing the primary image with a photo-detector array at the average primary focal surface location of a lens (e.g., positioning the lens such that a defined focal surface of the lens coincides with an imaging surface of a photo-detector array). Referring again to FIG. 2, one specific example of method step 603 (FIG. 6) would be controller 208 positioning photo-detector array 102 at a primary position, and thereafter instructing image capture unit 206 to capture an image from photo-detector array 102. Method step 603A depicts associating portions of the captured primary image with the projections of the virtual lenslets. In one implementation, method step 603A includes the sub-step of associating portions of the captured primary image with mathematical projections of the virtual lenslets. Referring again to FIGS. 2, 4, and 5, one specific example of method step 603A (FIG. 6) would be image capture unit 206 mapping the mathematical projections of the virtual lenslets 400 (FIGS. 4 and 5) into the primary image captured from photo-detector array 102. With reference again to FIG. 6, method step 604 illustrates determining focused and/or out-of-focus portions of the primary image that map with the projected virtual lenslets. In one implementation, method step 604 includes the sub-step of calculating a Fourier transform of at least a part of the primary image that maps to a virtual lenslet (e.g., sharp, or in-focus images produce abrupt transitions that often have significant high frequency components). Referring again to FIG. 2, one specific example of method step 604 (FIG. 6) would be focus detection unit 210 performing a Fourier transform and subsequent analysis on those virtual-lenslet mapped parts of an image that has been captured by image capture unit 206 when photo-detector array 102 was at the primary position. In this example, focus detection unit 210 could deem portions of the image having significant high frequency components as “in focus” images. As a more specific example, the Fourier transform and analysis may be performed on one or more parts of the image that are associated with one or more virtual lenslets 400 of lens 204 (e.g., FIGS. 4 and 5). With reference again to FIG. 6, method step 605 shows moving the photo-detector array to another position. In one implementation, method step 605 further includes the sub-step of moving at least a part of the photo-detector array to the other position while the lens is held stationary (e.g., photo-detector array 102 is moved to another position, while lens 204 remains stationary, such as shown and described in relation to FIGS. 4 and 5). In another implementation, the step of moving at least a part of the photo-detector array to the other position further includes the sub-step of tilting the photo-detector array. In another implementation, the step of moving at least a part of the photo-detector array to the other position further includes the sub-step of rotating the photo-detector array. In another implementation, the step of moving at least a part of the photo-detector array to the other position further includes the sub-step of tilting and rotating the photo-detector array. In another implementation, the step of moving at least a part of the photo-detector array to the other position further includes the sub-step of distorting the photo-detector array such that the at least a part of the photo-detector array resides at the other position (e.g., all or part of photo-detector array 102 is moved to another position, such as might happen if photo-detector array 102 were to be compressed laterally in a controlled manner or moved using micro-electro-mechanical-systems (MEMS) techniques, while lens 204 remains stationary, such as shown and described in relation to FIGS. 7, 8, and/or 9). Those having skill in the art will appreciate that the herein described tilting and/or rotating will move the photo-detector array in x, y, and/or z directions such that other image surfaces of lens 204 may be captured. Referring now to FIGS. 2, 7, 8, and/or 9, one specific example of method step 605 (FIG. 6) would be controller 208 positioning photo-detector array 102 at the other position using feedback control sub-systems (not shown). Those having skill in the art will appreciate that the herein described tilting and/or rotating will move photo-detector array 102 in x, y, and/or z directions such that other image surfaces of lens 204 may be approximately captured. As a specific example, successively tilting photo-detector array 102 such that successive relatively-in-focus virtual lenslet projections of actual tree 224 or actual bird 228 may be captured at or near the focused and/or undistorted tree image 104 and bird image 108 (e.g., as shown and described in relation to FIG. 2). With reference again to FIG. 6, method step 606 shows capturing another image with the photo-detector array at the other position. In one implementation, method step 606 further includes the sub-step of extracting at least one of a red, blue, and green color component of the other image. In another implementation, the step of extracting at least one of a red, blue, and green color component of the other image further includes the sub-step of numerically filtering the other image. Referring now to FIGS. 2, 7, 8, and/or 9, one specific example of method step 606 (FIG. 6) would be image capture unit 206 capturing an image from photo-detector array 102 at the other position. In one implementation, logic of image capture unit 206 communicates with logic of controller 208 to capture the other image when photo-detector array 102 is as the other position. In one implementation, logic of image capture unit 206 extracts at least one of a red, blue, and green color component of the other image. In one implementation, logic of image capture unit 206 extracts the at least one of a red, blue, and green color component by use of numerical filtering techniques. Method step 607 depicts associating portions of the captured other image with the projections of the virtual lenslets. In one implementation, method step 607 includes the sub-step of associating portions of the captured other image with mathematical projections of the virtual lenslets through a volume of space and onto an imaging surface of the photo-detector array at the other position. Referring again to FIGS. 2, 7, 8, and 9, one specific example of method step 607 (FIG. 6) would be image capture unit 206 mapping the mathematical projections of the virtual lenslets 400 (FIGS. 4 and 5) into the other image captured from photo-detector array 102. In one implementation of method step 607, logic of image capture unit 206 maps the mathematical projections of virtual lenslets 400 (FIGS. 4 and 5) into the other image captured from photo-detector array 102. In one implementation of method step 607, logic of image capture unit 206 determines where on re-positioned photo-detector array 102 the virtual lenslets 400 will project (e.g., mathematically projecting the virtual lenslets onto a known imaging surface location of the re-positioned photo-detector array). With reference again to FIG. 6, method step 608 depicts determining the focuses of the portion(s) of this other image that map with the projected virtual lenslets (e.g., the virtual lenslets of method step 601). In one implementation, method step 608 includes the sub-step of calculating a Fourier transform of at least a part of at least one region of the other image that maps with the projected virtual lenslets (e.g., sharp or in-focus images produce abrupt transitions that often have significant high frequency components). In one implementation, the step of calculating a Fourier transform of at least one region of the other image that maps with the projected virtual lenslets includes the sub-step of determining the Fourier transform and analysis on one or more parts of the image that are associated with one or more virtual lenslet projections intersecting the re-positioned photo-detector array. Referring again to FIGS. 2, 7, 8, and/or 9, one specific example of method step 608 (FIG. 6) would be focus detection unit 210 performing a Fourier transform and subsequent analysis on at least a part of an image captured by image capture unit 206 when photo-detector array 102 was at the other position specified by controller 208. In one specific example, focus detection unit 210 receives an image and its associated virtual lenslet projections from image capture unit 206 and thereafter performs the Fourier transforms and subsequent analyses on a per-virtual-lenslet basis, and thereafter stores the results of the transforms and analyses in memory. Those skilled in the art will appreciate that such Fourier transforms and subsequent analyses constitute specific examples of more “image scores,” and that other suitable image analysis techniques, consistent with the teachings herein, may be substituted for the Fourier transform and analysis. With reference again to FIG. 6, method step 610 depicts constructing a volumetric image by replacing the out-of-focus virtual lenslet portion(s) of the primary image with their more in-focus counterparts. In one implementation, method step 610 includes the sub-step of replacing at least a part of one out-of-focus virtual-lenslet region of the primary image with at least a part of one more-in-focus virtual-lenslet region of the other image. In yet another implementation, method step 610 includes the sub-step of utilizing at least one of tiling image processing techniques, morphing image processing techniques, blending image processing techniques, and stitching image processing techniques. In yet another implementation, method step 610 includes the sub-steps of correlating a feature of the primary image with a feature of the other image; detecting at least one of size, color, and displacement distortion of at least one of the primary image and the other image; correcting the detected at least one of size, color, and displacement distortion of the at least one of the primary image and the other image; and assembling the composite image using the corrected distortion. In yet another implementation, these sub-steps are performed on a per-virtual-unit basis. In yet another implementation, method step 610 includes the sub-step of correcting for motion between the primary and the other image. In yet another implementation, this sub-step is performed on a per-virtual-lenslet basis. Referring again to FIGS. 2, 7, 8, and/or, 9 one specific example of method step 610 (FIG. 6) would be logic of volumetric image construction unit 212 creating a composite image replacing those virtual lenslet associated portions of an image captured at a primary position with more in-focus virtual lenslet associated portions of an image captured by image capture unit 206 when photo-detector array 102 was at the other position. In one implementation of the example, volumetric image construction unit 212 corrects for the motion between images using conventional techniques if such correction is desired. In another implementation of the example, motion correction is not used. With reference again to FIG. 6, method step 612 shows a determination of whether an aggregate change in photo-detector position, relative to the primary position of method step 602, has exceeded a maximum specified change in photo-detector position. For example, there will typically be a limit on the volume which photo-detector array 102 is to sweep out as it is moved about, and that volume limit will indicate limits in x, y, and z-axis movements. Referring again to FIGS. 2, 7, 8, and/or 9, one specific example of method step 612 (FIG. 6) would be controller 208 comparing an aggregate movement in a defined direction against a pre-stored upper limit value. In an implementation of the example illustrated in FIG. 4, controller 208 will determine whether the total forward movement of photo-detector array 102 is greater than a predefined forward movement limit relative to the primary position. In an implementation of the example illustrated in FIG. 5, controller 208 will determine whether the total rearward movement of lens 204 is greater than 0.05 mm relative to the primary position. In other implementations, manufacturing criteria in x-y provide analogous tolerances in x-y distortion which likewise give rise to pre-stored upper limit values in x-y rotation. With reference again to FIG. 6, if the inquiry of method step 612 yields a determination that the aggregate change in position has met or exceeded the maximum specified change in photo-detector position, the process proceeds to method step 614. Method step 614 illustrates that the current composite image (e.g., of method step 610) is stored and/or displayed. One specific example of method step 614 would be image store/display unit 214 either storing or displaying the composite image. Method step 616 shows the end of the process. Returning to method step 612, shown is that in the event that the upper limit on maximum specified change in photo-detector position has not been met or exceeded, the process proceeds to method step 605 and continues as described herein (e.g., moving the photo-detector to yet another position (method step 605) and capturing yet another image (e.g., method step 606) . . . ). Referring now to FIGS. 7 and 8, depicted are partial perspective views of the system of FIG. 2 wherein photo-detector array 102 is being moved in accordance with aspects of processes shown and described herein (e.g., in relation to FIG. 6). Photo-detector array 102 is illustrated as being rotated through other positions different from the primary position which gave rise to tree image 104, person image 106, and bird image 108 shown and described in relation to FIGS. 1-5. The remaining components and control aspects of the various parts of FIGS. 7 and 8 (shown and unshown) function as described elsewhere herein. Referring now to FIG. 9, illustrated is a perspective view of the system of FIG. 2 wherein photo-detector array 102 is being moved in accordance with aspects of the process shown and described herein (e.g., in relation to FIG. 6). Photo-detector array 102 is illustrated as being tilted through other positions different from the primary position which gave rise to the five different portions of image 100 shown and described in relation to FIGS. 1 and 2. The remaining components and control aspects of the various parts of FIG. 9 (shown and unshown) function as described elsewhere herein. Those having skill in the art will recognize that the state of the art has progressed to the point where there is little distinction left between hardware and software implementations of aspects of systems; the use of hardware or software is generally (but not always, in that in certain contexts the choice between hardware and software can become significant) a design choice representing cost vs. efficiency tradeoffs. Those having skill in the art will appreciate that there are various vehicles by which processes and/or systems described herein can be effected (e.g., hardware, software, and/or firmware), and that the preferred vehicle will vary with the context in which the processes are deployed. For example, if an implementer determines that speed and accuracy are paramount, the implementer may opt for a hardware and/or firmware vehicle; alternatively, if flexibility is paramount, the implementer may opt for a solely software implementation; or, yet again alternatively, the implementer may opt for some combination of hardware, software, and/or firmware. Hence, there are several possible vehicles by which the processes described herein may be effected, none of which is inherently superior to the other in that any vehicle to be utilized is a choice dependent upon the context in which the vehicle will be deployed and the specific concerns (e.g., speed, flexibility, or predictability) of the implementer, any of which may vary. Those skilled in the art will recognize that optical aspects of implementations will require optically-oriented hardware, software, and or firmware. The foregoing detailed description has set forth various embodiments of the devices and/or processes via the use of block diagrams, flowcharts, and examples. Insofar as such block diagrams, flowcharts, and examples contain one or more functions and/or operations, it will be understood as notorious by those within the art that each function and/or operation within such block diagrams, flowcharts, or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. In one embodiment, the present invention may be implemented via Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), or other integrated formats. However, those skilled in the art will recognize that the embodiments disclosed herein, in whole or in part, can be equivalently implemented in standard integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the present invention are capable of being distributed as a program product in a variety of forms, and that an illustrative embodiment of the present invention applies equally regardless of the particular type of signal bearing media used to actually carry out the distribution. Examples of a signal bearing media include, but are not limited to, the following: recordable type media such as floppy disks, hard disk drives, CD ROMs, digital tape, and computer memory; and transmission type media such as digital and analog communication links using TDM or IP based communication links (e.g., packet links). In a general sense, those skilled in the art will recognize that the various embodiments described herein which can be implemented, individually and/or collectively, by various types of electromechanical systems having a wide range of electrical components such as hardware, software, firmware, or virtually any combination thereof; and a wide range of components that may impart mechanical force or motion such as rigid bodies, spring or torsional bodies, hydraulics, and electro-magnetically actuated devices, or virtually any combination thereof. Consequently, as used herein “electromechanical system” includes, but is not limited to, electrical circuitry operably coupled with a transducer (e.g., an actuator, a motor, a piezoelectric crystal, etc.), electrical circuitry having at least one discrete electrical circuit, electrical circuitry having at least one integrated circuit, electrical circuitry having at least one application specific integrated circuit, electrical circuitry forming a general purpose computing device configured by a computer program (e.g., a general purpose computer configured by a computer program which at least partially carries out processes and/or devices described herein, or a microprocessor configured by a computer program which at least partially carries out processes and/or devices described herein), electrical circuitry forming a memory device (e.g., forms of random access memory), electrical circuitry forming a communications device (e.g., a modem, communications switch, or optical-electrical equipment), and any non-electrical analog thereto, such as optical or other analogs. Those skilled in the art will also appreciate that examples of electromechanical systems include but are not limited to a variety of consumer electronics systems, as well as other systems such as motorized transport systems, factory automation systems, security systems, and communication/computing systems. Those skilled in the art will recognize that electromechanical as used herein is not necessarily limited to a system that has both electrical and mechanical actuation except as context may dictate otherwise. Those skilled in the art will recognize that it is common within the art to describe devices and/or processes in the fashion set forth herein, and thereafter use standard engineering practices to integrate such described devices and/or processes into image processing systems. That is, at least a portion of the devices and/or processes described herein can be integrated into an image processing system via a reasonable amount of experimentation. Those having skill in the art will recognize that a typical image processing system generally includes one or more of a system unit housing, a video display device, a memory such as volatile and non-volatile memory, processors such as microprocessors and digital signal processors, computational entities such as operating systems, drivers, and applications programs, one or more interaction devices, such as a touch pad or screen, control systems including feedback loops and control motors (e.g., feedback for sensing lens position and/or velocity; control motors for moving/distorting lenses to give desired focuses. A typical image processing system may be implemented utilizing any suitable commercially available components, such as those typically found in digital still systems and/or digital motion systems. The foregoing described embodiments depict different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely exemplary, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected” or “operably coupled” to each other to achieve the desired functionality. While particular embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that, based upon the teachings herein, changes and modifications may be made without departing from this invention and its broader aspects and, therefore, the appended claims are to encompass within their scope all such changes and modifications as are within the true spirit and scope of this invention. Furthermore, it is to be understood that the invention is solely defined by the appended claims. It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” “comprise” and variations thereof, such as, “comprises” and “comprising” are to be construed in an open, inclusive sense, that is as “including, but not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). | <SOH> TECHNICAL FIELD <EOH>The present application relates, in general, to imaging. | <SOH> SUMMARY <EOH>In one aspect, a method includes but is not limited to: capturing a primary image representation with a photo-detector array at a primary position; associating a primary set of discrete portions of the primary image representation with one or more defined virtual lenslets of a lens; moving the photo-detector array to another position; capturing another image representation with the photo-detector array at the other position; associating another set of discrete portions of the other image representation with the one or more defined virtual lenslets of the lens; and assembling a volumetric image from those virtual lenslet associated portions of the primary and the other image representation that have relatively sharper focuses. In addition to the foregoing, other method aspects are described in the claims, drawings, and text forming a part of the present application. In one or more various aspects, related systems include but are not limited to circuitry and/or programming for effecting the herein-referenced method aspects; the circuitry and/or programming can be virtually any combination of hardware, software, and/or firmware configured to effect the herein-referenced method aspects depending upon the design choices of the system designer. In one aspect, a system includes but is not limited to: capturing a primary image representation with a photo-detector array at a primary position; associating a primary set of discrete portions of the primary image representation with one or more defined virtual lenslets of a lens; moving the photo-detector array to another position; capturing another image representation with the photo-detector array at the other position; associating another set of discrete portions of the other image representation with the one or more defined virtual lenslets of the lens; and assembling a volumetric image from those virtual lenslet associated portions of the primary and the other image representations that have relatively sharper focuses. In addition to the foregoing, other system aspects are described in the claims, drawings, and text forming a part of the present application. In one aspect, a system includes but is not limited to: a lens associated with one or more virtual lenslets; a controller configured to position a photo-detector array at a primary and another position; an image capture unit configured to capture a primary image at the primary position and another image at the other position; and a volumetric image construction unit configured to utilize at least a part of the one or more virtual lenslets in association with at least one of the primary image and the other image. In addition to the foregoing, other system aspects are described in the claims, drawings, and text forming a part of the present application. In addition to the foregoing, various other method and/or system aspects are set forth and described in the text (e.g., claims and/or detailed description) and/or drawings of the present application. The foregoing is a summary and thus contains, by necessity, simplifications, generalizations and omissions of detail; consequently, those skilled in the art will appreciate that the summary is illustrative only and is NOT intended to be in any way limiting. Other aspects, inventive features, and advantages of the devices and/or processes described herein, as defined by the claims, will become apparent in the detailed description set forth herein. | 20040224 | 20070619 | 20050825 | 66750.0 | 0 | SPECTOR, DAVID N | VOLUMETRIC IMAGING USING "VIRTUAL'' LENSLETS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,785,735 | ACCEPTED | Location based messaging | Systems and methods are provided for messages, such as short messages and multi-media messages. In one implementation a message is received from a sender, a location of the sender is determined, the message is modified to include the location of the sender, and the modified message is transmitted to a recipient. | 1. A method of processing a message, the method comprising: receiving a message from a sender; determining a location of the sender; modifying the message to include the location of the sender; and transmitting the modified message to a recipient. 2. The method of claim 1, wherein the message includes a request to include the location of the sender in the message. 3. The method of claim 2, wherein the request comprises a location-request code added to a destination number included in the message. 4. The method of claim 3, wherein transmitting the modified message to a recipient comprises transmitting the modified message to a recipient associated with the destination number. 5. The method of claim 1, wherein the message is a multi-media message. 6. The method of claim 1, wherein the message is a short message. 7. The method of claim 1, further comprising: based on the location-request code, transmitting the message to a location server; receiving from the location server the modified message; wherein, the location server performs the steps of determining a location of the sender and modifying the message to include the location of the sender. 8. The method of claim 7, further comprising: the location server further modifying the message to remove the location-request code from the destination number. 9. The method of claim 7, wherein the location server performing the step of determining a location of the sender comprises sending a request from the location server to a location-enabled server and receiving at the location server a location of the sender from the location-enabled server. 10. The method of claim 7, wherein the location server performing the step of determining a location of the sender comprises retrieving a location for the sender from a cache of location information. 11. The method of claim 10, wherein retrieving a location for the sender from a cache of location information further comprises: receiving location information from a plurality of network probes about locations of a plurality of network users including the sender; periodically caching the location information for the plurality of network users including the sender; and retrieving at the location server a location for the sender from the cache of location information. 12. The method of claim 1, further comprising: modifying the message to add a location-request code to a sender number included in the message, where the location-request code is a request to include the recipient's location in a reply message to the message. 13. The method of claim 12, wherein modifying the message to add a location-request code to a sender number further comprises: determining if a location of the recipient can be included in a message originating from the recipient; if a location of the recipient can be included, then modifying the message. 14. The method of claim 1, wherein determining a location of the sender comprises: querying a location enabled server for a location of the sender; and receiving a location of the sender from the location enabled server. 15. The method of claim 1, wherein determining a location of the sender comprises: retrieving a location for the sender from a cache of location information 16. The method of claim 1, wherein retrieving a location for the sender from a cache of location information comprises: receiving location information from a plurality of network probes about locations for a plurality of network users including the sender; periodically caching the location information for the plurality of network users including the sender; and retrieving a location for the sender from the cache of location information. 17. A method of processing a message, comprising: receiving a message from a first messaging service center; determining a location of a sender of the message; modifying the message to include the location of the sender; and transmitting the modified message to a second messaging service center. 18. The method of claim 17, wherein the message is a short message, and the first messaging service center and the second messaging service centers are short messaging service centers. 19. The method of claim 17, wherein the message is a multi-media message, and the first messaging service center and the second messaging service centers are multi-media messaging service centers. 20. The method of claim 17, wherein the first messaging service center and the second messaging service center are the same messaging service centers. 21. The method of claim 17, wherein the first messaging service center services a mobile network used by a sender of the message and the second messaging service center services a mobile network used by a recipient of the message. 22. The method of claim 17, wherein the message includes a location-request code added to a destination number, the method further comprising: before transmitting the modified message to the second messaging service center, further modifying the message to remove the location-request code from the destination number. 23. The method of claim 17, wherein determining a location of the sender comprises sending a request to a location-enabled server and receiving a location of the sender from the location-enabled server. 24. The method of claim 17, wherein determining a location of the sender comprises retrieving a location for the sender from a cache of location information. 25. The method of claim 24, wherein retrieving a location for the sender from a cache of location information further comprises: receiving location information from a plurality of network probes about locations for a plurality of network users including the sender; periodically caching the location information for the plurality of network users including the sender; and retrieving a location for the sender from the cache of location information. 26. A method of processing a message, comprising: inputting a message into a mobile station; inputting into the mobile station a location-request code and a destination number, where the location-request code specifies a request to modify the message to include a location of the mobile station in the message and where the destination number specifies a destination for delivery of the message; and transmitting the message from the mobile station to a messaging service center. 27. The method of claim 26, wherein the message is a short message. 28. The method of claim 26, wherein the message is a multi-media message. 29. A system for processing a message, comprising: a sender mobile station configured to receive a user input and based on the user input transmit a message over a mobile network for delivery to a recipient messaging entity associated with a destination number, where the message includes a request to include a location of the sender mobile station in the message; a messaging service center configured to: receive from a sender mobile station a message including a request to include a location of the sender mobile station in the message; transmit the message to a location server; receive a modified message from a location server; transmit the modified message to a recipient messaging entity; a location server configured to: receive a message from a messaging center, the message including a request to include a location of a sender mobile station in the message; determine a location of the sender mobile station; modify the message to include the location; and transmit the modified message to a messaging center; and a recipient messaging entity configured to receive a message including a location of a sender mobile station from which the message originated. 30. The system of claim 29, wherein: the message is a short message, and the messaging service center is a short messaging service center. 31. The system of claim 29, wherein: the message is a multi-media message, and the messaging service center is a multi-media messaging service center. 32. A method of processing a multi-media message, comprising: receiving a multi-media message originating from a sender mobile station, the multi-media message including destination information; determining a location of the sender mobile station; modifying the multi-media message to include the location of the sender mobile station; and transmitting the modified multi-media message to a recipient based on the destination information. 33. The method of claim 32, wherein the transmitting step further comprises: accessing a user profile associated with the sender mobile station; based on the user profile and the destination information, determining an e-mail address associated with the recipient; and transmitting the modified multi-media message to the recipient e-mail address. 34. The method of claim 32, wherein determining a location of the sender mobile station comprises: querying a location enabled server for a location of the sender mobile station; and receiving a location of the sender mobile station from the location enabled server. 35. The method of claim 32, wherein determining a location of the sender mobile station comprises: retrieving a location for the sender mobile station from a cache of location information. 36. The method of claim 35, wherein retrieving a location for the sender mobile station from a cache of location information comprises: receiving location information from a plurality of network probes about locations for a plurality of network users including the sender mobile station; periodically caching the location information for the plurality of network users including the sender mobile station; and retrieving a location for the sender mobile station from the cache of location information. | BACKGROUND The following disclosure relates to processing a message, such as a short message or a multi-media message. Short messaging service (SMS) is a globally accepted service for transmitting short messages between wireless devices. Typically a “short message” is 160 alpha-numeric characters or less, and can be transmitted between mobile subscribers, e.g., using mobile telephones, over a wireless network or between a mobile device and a system external to the wireless network, such as application server for handling electronic mail or paging. SMS uses the mobile application protocol (MAP) which, in the mobile network context, is an application layer protocol designed to support database interrogation and mobility management, and uses the services of the SS7 (Signalling System No.7) transaction capabilities application part (TCAP). The American and the international standards bodies have defined a MAP layer using the services of the SS7 TCAP: the American standard is published by the Telecommunication Industry Association and is referred to as IS-41, and the international standard is defined by the European Telecommunication Standards Institute and is referred to as GSM (global standard for mobiles) MAP. Some additional protocols used in short messaging include the Short Message Peer to Peer (SMPP) protocol, an open industry standard messaging protocol designed to simplify integration of data applications with wireless mobile networks, and the Universal Computer Protocol (UCP). A short messaging entity (SME) is an entity which may receive or send short messages, and may be located in a fixed network or a wireless network. For example, a SME can be a mobile station (MS), such as a mobile telephone, that sends and receives messages over a wireless network. A different example of an SME is a personal computer used to receive short messages into an e-mail account via an e-mail server that communicates with a wireless network. Referring to FIG. 1, a base station system (BSS) 110 receives a short message transmitted from a mobile station (MS) 105. For example, the mobile station 105 can be a mobile telephone, and a user can input the short message using a user interface on the mobile telephone, and include a destination number that is associated with a recipient mobile station 145, i.e., a telephone number. Abase-station system 110 typically consists of base-station controllers and base-transceiver stations and is responsible for transmitting voice and data traffic between mobile stations. The base-station system 110 transmits the short message to a mobile switching center (MSC) 115. The mobile switching center 115 performs switching functions for a mobile system and controls calls to and from other telephone and data systems; typically a MSC 115 services multiple base-station systems. The short message is routed from the mobile switching center 115 to a short messaging service center (SMSC) 120. The SMSC 120 is responsible for the relaying and store-and-forwarding of a short message between short message entities, including mobile stations. The SMSC 120 makes a determination based on the destination number, for example, using a look-up table, whether the short message should be rerouted to a different SMSC or whether routing information for the short message can be obtained by the SMSC 120 from a home location register (HLR) 125. For the sake of simplicity, in this example, the SMSC 120 determines that routing information can be obtained from the HLR 125, and proceeds to interrogate the HLR 125 for the routing information. An HLR 125 is a database used for permanent storage and management of subscriptions and service profiles of network users. The routing information provided by an HLR 125 is at the “MSC level”, meaning an HLR 125 can provide information as to which MSC in a wireless network to which to route the short message so that it can be routed to a recipient mobile station 145 associated with the destination number. Based on the routing information, the SMSC 120 transmits the short message to a MSC 130 that is presently servicing the recipient mobile station 145 (i.e., as the recipient mobile station 145 moves through the network, the MSC that is presently servicing the mobile station 145 can change). The MSC 130 interrogates a visitor location register (VLR) 135, which is a database that contains temporary location information about network users that are currently in the area of a base station serviced by the MSC 130. That is, the location information in the VLR 135 is at the base station transceiver (i.e., cell tower) level, as compared to the routing information provided by the HLR 125, which is at the MSC level. Based on information received from the VLR 135, the MSC 130 routes the short message to a base-station system 140 and from there the short message is delivered to the recipient mobile station 145. Delivery of the short message to the recipient mobile station 145 is based on the destination number input by the user of the sender mobile station 105. In addition to the destination number, the short message typically includes a sender number, that is, a number that is associated with the sender mobile station 105, such as the sender's mobile telephone number. The recipient mobile station 105 can reply to the short message, which reply is automatically routed to the sender mobile station 105 based on the sender number included in the original short message, similar to an e-mail user clicking on the “reply” button when replying to an e-mail message. The reply short message is routed to the sender mobile station 105 using the same steps described above to route the original message to the recipient mobile station 145. Multi-media messaging service (MMS) is similar to SMS, except that in addition to text, multi-media messages can include graphics, audio, images and video. A multi-media message can be transmitted from a sender mobile station 105 to a recipient mobile station 145 in a similar manner as an SMS, except that the SMSC 120 is replaced by a multi-media messaging center (MMSC), which provides corresponding functions for multi-media messages. In some instances, for example, if the recipient mobile station 145 is not MMS-enabled, the MMSC stores the content of the multi-media message and sends a short message, referred to as a “notification message”, to the recipient mobile station 145 advising the recipient mobile station 145 that there is a multi-media message available for the recipient to retrieve from a location provided in the notification message as a link, for example, to a URL. A user of the recipient mobile station 145 can click on the link and retrieve the content of the multi-media message from the location, which may be a server included in the MMSC. A recipient of a multi-media message can be an e-mail address, in which case the MMSC routes the multi-media message to an application server, i.e., an e-mail server. MMS is a global service and also uses various well known protocols and standards. SUMMARY The following describes apparatus and techniques relating to messages, such as short messages and multi-media messages. In general, in one aspect, the invention features a method of processing a message, including the steps of receiving a message from a sender, determining a location of the sender, modifying the message to include the location of the sender, and transmitting the modified message to a recipient. Implementations may feature one or more of the following. The message can be, for example, a short message or a multi-media message. The message can include a request to include the location of the sender in the message. The request can be a location-request code added to a destination number included in the message. Transmitting the modified message to a recipient can include transmitting the modified message to a recipient associated with the destination number. The message can be transmitted to a location server, based on the location-request code, and the location server can perform the steps of determining a location of the sender and modifying the message to include the location of the sender. The location server can further modify the message to remove the location-request code from the destination number. Determining a location of the sender can include sending a request (e.g., from the location server) to a location-enabled server and receiving a location of the sender from the location-enabled server. Alternatively, a location of the sender can be retrieved from a cache of location information. Retrieving a location for the sender from a cache of location information can include: receiving location information from multiple network probes about locations of multiple network users including the sender; periodically caching the location information for the network users; and retrieving a location for the sender from the cache of location information. The message can be further modified to add a location-request code to a sender number included in the message, where the location-request code is a request to include the recipient's location in a reply message to the message. Modifying the message to add a location-request code to a sender number can include determining if a location of the recipient can be included in a message originating from the recipient, and if a location of the recipient can be included, then modifying the message. In general, in another aspect, the invention features a method of processing a message, including the steps of receiving a message from a first messaging service center, determining a location of a sender of the message, modifying the message to include the location of the sender, and transmitting the modified message to a second messaging service center. Implementations can include one or more of the following. The message can be a short message, and the first messaging service center and the second messaging service centers can be short messaging service centers. Alternatively, the message can be a multi-media message, and the first messaging service center and the second messaging service centers can be multi-media messaging service centers. The first messaging service center and the second messaging service center can be the same messaging service centers. The first messaging service center can service a mobile network used by a sender of the message, and the second messaging service center can service a mobile network used by a recipient of the message. The message can include a location-request code added to a destination number, and before transmitting the modified message to the second messaging service center, the message can be further modified to remove the location-request code from the destination number. Determining a location of the sender can include sending a request to a location-enabled server and receiving a location of the sender from the location-enabled server. Alternatively, determining a location of the sender can include retrieving a location for the sender from a cache of location information. Retrieving a location from a cache of location information can include receiving location information from multiple network probes about locations for multiple network users including the sender, periodically caching the location information for the network users, and retrieving a location for the sender from the cache of location information. In general, in another aspect, the invention features, a method of processing a message including the steps of inputting a message into a mobile station, inputting into the mobile station a location-request code and a destination number, where the location-request code specifies a request to modify the message to include a location of the mobile station in the message and where the destination number specifies a destination for delivery of the message, and transmitting the message from the mobile station to a messaging service center. In one implementation the message can be a short message, and in another implementation the message can be a multi-media message. In general, in another aspect, a system for processing a message features a sender mobile station, a messaging service center, a location server and a recipient messaging entity. The sender mobile station is configured to receive a user input and based on the user input transmit a message over a mobile network for delivery to a recipient messaging entity associated with a destination number, where the message includes a request to include a location of the sender mobile station in the message. The messaging service center is configured to receive from a sender mobile station a message including a request to include a location of the sender mobile station in the message, transmit the message to a location server, receive a modified message from a location server, transmit the modified message to a recipient messaging entity. The location server is configured to receive a message from a messaging center, the message including a request to include a location of a sender mobile station in the message; determine a location of the sender mobile station; modify the message to include the location; and transmit the modified message to a messaging center. The recipient messaging entity is configured to receive a message including a location of a sender mobile station from which the message originated. Implementations can include one or more of the following. The message can be a short message, and the messaging service center can be a short messaging service center. Alternatively, the message can be a multi-media message, and the messaging service center can be a multi-media messaging service center. In general, in another aspect, a method of processing a multi-media message includes the steps of receiving a multi-media message originating from a sender mobile station, the multi-media message including destination information; determining a location of the sender mobile station; modifying the multi-media message to include the location of the sender mobile station; and transmitting the modified multi-media message to a recipient based on the destination information. Implementations can include one or more of the following. The transmitting step can further include accessing a user profile associated with the sender mobile station; based on the user profile and the destination information, determining an e-mail address associated with the recipient; and transmitting the modified multi-media message to the recipient e-mail address. Determining a location of the sender mobile station can include querying a location enabled server for a location of the sender mobile station, and receiving a location of the sender mobile station from the location enabled server. Alternatively, determining a location of the sender mobile station can include retrieving a location for the sender mobile station from a cache of location information. Retrieving a location for the sender mobile station from a cache of location information can include receiving location information from multiple network probes about locations for a multiple network users including the sender mobile station, periodically caching the location information for the network users including the sender mobile station, and retrieving a location for the sender mobile station from the cache of location information. Implementations of the invention can realize one or more of the following advantages. A current location of a sender mobile station can automatically be included in a message, such as a short message or multi-media message, originating from the sender mobile station. A location server can be used to determine a location of a sender mobile station and modify a message to include the location without requiring a software or hardware upgrade of mobile network elements, such as a short messaging service center or a multi-media messaging center. The short messaging service center or multi-media messaging center can process a short message or multi-media message that includes a location request without awareness of the location request, and the message can be seamlessly diverted to and received back from a location server with the location of the sender mobile station added thereto. Mobile users can use the location request service with a mobile station, e.g., a mobile telephone or other such handset, that is two-way SMS or MMS capable without requiring any upgrades to the mobile station. A user of a sending device can decide on a message-by-message basis whether to include a request to add the location of the sending device to a message originating from the sending device. The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. DESCRIPTION OF DRAWINGS FIG. 1 shows a schematic representation of a conventional transmission path of a short message. FIG. 2 is a flowchart showing a process for modifying a short message to include a location of a sender. FIG. 3 shows a schematic representation of the transmission path of a short message and a modified short message. FIG. 4 is a flowchart showing a process for creating a short message including a location request. FIG. 5 is a flowchart showing a process for including a location of a sender in a short message. FIG. 6 is a flowchart showing a process for modifying a short message to include a location of a sender. FIG. 7 is a flowchart showing a process for modifying a short message to include a location of a sender and include a location-request for a reply to the short message. FIG. 8 shows a schematic representation of the transmission path of a multi-media message and a modified multi-media message. FIG. 9 is a flowchart showing a process for including a location of a sender in a multi-media message. FIG. 10 shows a schematic representation of a transmission path of a multi-media message delivered to an e-mail address. FIG. 11 shows a schematic representation of a transmission path of a multi-media message and a modified multi-media message that is delivered to an e-mail address. FIG. 12A is a flowchart showing a process for creating a multi-media message including a location-request. FIG. 12B is a flowchart showing a process for including a location of a sender in a multi-media message for delivery to an e-mail address. Like reference symbols in the various drawings indicate like elements. DETAILED DESCRIPTION A short message typically includes some information in addition to the text input by a sender, such as the destination number, the sender's number (e.g., a MSISDN (mobile station integrated services digital number) such as a mobile telephone number, or an e-mail address), the time the short message was sent and a date stamp. Referring to FIG. 2, a process 200 is shown for including a location of a sender at the time a short message originated from the sender in the short message. A SMSC receives a short message that originated with a sender mobile station (step 205) and determines a current location of the sender mobile station (step 210). The SMSC then modifies the short message to include the current location of the sender mobile station (step 215) and proceeds to route the short message to a recipient mobile station (step 220). Referring to FIG. 3, a transmission path of a short message that is modified to include a location of a sender mobile station 305 is shown. FIG. 4 shows a process 400 of a user of a sender mobile station 305 transmitting a short message. In a first step, a user of the sender mobile station 305 inputs a short message including a destination number associated with a recipient mobile station 345 (step 405). The term destination number as used herein refers to an identifier of a recipient, such as a mobile telephone number associated with a recipient mobile station, an e-mail address, an IP address, and the like, and accordingly may or may not be an actual number per se. The user or system includes within the short message an indication that the current location of the sender mobile station 305 is to be included in the short message that is delivered to the recipient mobile station 345 (step 410). For example, the user or system can add a “location-request code” to the beginning of the destination number, such as inputting prefix digits, e.g., “99”, before the destination number. Alternatively, the location-request code can be programmed into the sender mobile station 305, so that the user can simply press a specified button on the user interface to automatically add the location-request code to the destination number. In another alternative, the sender mobile station 305 can be programmed so that as a default a location-request code is automatically added to the destination number of a short message originating from the sender mobile station 305. Alternatively, a network element other than the sender mobile station 305, such as the SMSC 320 or a MSC 315, can prompt the inclusion of the sender mobile station's location in the short message. For example, the SMSC 320 can determine whether a sender mobile station is “location-enable” (e.g., a subscriber to a location enabled service), and if so then include the location of the sender mobile station in the short message. Other techniques for including a location-request code in a short message can be used. The short message including the location-request code is transmitted from the sender mobile station 305 to a base-station system 310, to a mobile switching center 315 and finally to a SMSC 320 (step 415). FIG. 5 shows an exemplary process 500 for including a current location of a sender mobile station in the short message using a location server 350. The process 500 relates to one implementation where a location server 350 is used to determine the current location of the sender mobile station 305. Typically, when the SMSC 320 receives the short message originating from the sender mobile station 305 (step 510), the SMSC 320 uses the destination number included therein to route the short message. The SMSC 320 may use a look-up table to determine an appropriate second SMSC to reroute the short message to if the destination number is on a different network. Alternatively, the SMSC 320 may query the HLR 325 for routing information for the recipient mobile station 345 associated with the destination number, if the destination number is within a network serviced by the SMSC 320. If the destination number is an address, such as an IP address of an application server, the SMSC 320 may route the short message to the address. When the SMSC 320 receives the short message including the location-request code included at the beginning of the destination number, the SMSC 320 interprets the location-request code as a “destination number” and routes the short message to a location server 350 associated with the destination number. For example, the SMSC 320 can parse the short message to retrieve a destination number beginning with the digits “99” (where “99” is the location-request code). The SMSC 320 performs a look-up in a look-up table to determine a destination associated with “99” and retrieves an address, e.g., an IP address; the address can be the address for the location server 350. The SMSC 320 then transmits the short message to the address, i.e., to the location server 350 (step 515). The location server 350 is capable of receiving and sending short messages and is therefore a short messaging entity (SME). The SMSC 320 does not need to be aware of the purpose of routing the short message to the location server 350, i.e., to determine a current location of the sender mobile station 305, and from the perspective of the SMSC 320, processing of the short message is complete, since a destination was determined (i.e., the location server 350) and the short message was routed accordingly. The SMSC 320 subsequently receives a modified short message from the location server 350 (step 520); the SMSC 320 may not necessarily recognize the modified short message as a modified version of a previously processed short message, i.e., from the perspective of the SMSC 320 the modified short message is just another short message to be processed. The SMSC 320 can use a destination number for the recipient mobile station 345 included in the modified short message to route the modified short message to a second SMSC for processing or to query the HLR 325 for routing information for the recipient mobile station 345, and route the modified short message to a mobile switching center 330 based on the routing information (step 525). For the purpose of this example, the modified short message is not re-routed to a second SMSC. The mobile switching center 330 may interrogate a VLR 335 for temporary routing information about the recipient mobile station 345 and, based on the information, route the modified short message to a base-system station 340 serving the vicinity of the recipient mobile station 345. The modified short message is then finally sent from a base-station transceiver to the recipient mobile station 345. In another implementation, the location server 350 can include, or have access to, information so that the location server 350 can determine an appropriate SMSC to route the modified short message to, based on the destination number. The location server 350 can then route the modified short message directly to the appropriate SMSC, rather than automatically route the modified short message back to the SMSC 320, although in some instances the SMSC 320 will be the appropriate SMSC. Referring to FIG. 6, a process 600 is shown wherein the location server 350 determines a current location of the sender mobile station 305 and modifies the short message. The location server 350 receives the short message from the SMSC 320 (step 610), the short message including the sender's number, that is, a number associated with the sender mobile station 305. The location server 350 can use various techniques for determining the sender mobile station's 305 current location (step 615). In one implementation, location server 350 includes, or has access to, information about which “location-enabled server” (LES) in a mobile network is dynamically tracking the location of the sender mobile station 305. For example, the location server 350 can look-up the sender's number in a look-up table and determine an address of a corresponding LES. A LES is a server maintained by a network provider, for example, AT&T Wireless, that dynamically tracks the location of network users typically in the form of geographic coordinates, i.e., the latitude and longitude of the sender mobile station's 305 position. The location server 350 can send a request via the wireless or a wired network to the LES 355, which responds by transmitting the current location of the sender mobile station 305 to the location server 350. In another implementation, the location server 350 can passively monitor the locations of network users, for example, by receiving location information from network probes that monitor the network users that are within the vicinity of a probe at a given time, and periodically caching the location information. When a location is required, the location server 350 retrieves the location from the cache of location information. The location cache can be compiled by using location information from existing network probes, network probes that exist for the purpose of providing information to a location server, or a combination of the two. For example, a network probe can be an acceSS7 device available from Agilent Technologies of Palo Alto, Calif. Other techniques for determining the location of the sender mobile station 305 can be used. As mentioned above, the location of the sender mobile station 305 determined by the location server 350 can be in the form of geographic coordinates, i.e., the latitude and longitude of the sender mobile station 305. A user of the recipient mobile station 345 may prefer the location to identify a city, street or street address. Thus, optionally, the location server 350 can translate the determined location from a received format, such as geographic coordinates, into a more meaningful format, such as a street address, for example, by querying a database including geographic coordinate locations mapped to street address locations. The location server 350 modifies the short message to include the location of the sender mobile station 305 (step 620), the location being expressed in any desirable format, such as geographic coordinates, a street address or otherwise. The location server 350 can perform a further modification to the short message before transmitting the short message back to the SMSC 320; the location server 350 can remove the location-request code, since the location request has now been satisfied. That is, the location server 350 can remove the location-request code that was added to the beginning of the destination number (step 625). The location server 350 now transmits the modified short message back to the SMSC 320 (step 630). The modified short message received by the SMSC 320 includes a destination number without the location-request code added thereto. Accordingly, when the SMSC 320 parses the short message to determine a destination number to which to route the short message, the SMSC 320 determines the destination number associated with the recipient mobile station 345. The SMSC 320 can look-up the destination number in a look-up table, and if the destination number is in a different network, the SMSC 320 routes the modified short message to a SMSC in the different network, otherwise (as is the case in the present example) the SMSC 320 queries the HLR 325 for routing information. By contrast, when the SMSC 320 received the original short message (i.e., pre-modification), and looked up the destination number (which included as prefix digits the location-request code) in a look-up table, the SMSC 320 found an address for the location server 350 and routed the short message to the location server 350. By the location server 350 removing the location-request code from the short message, the SMSC 320 can now route the modified short message to the appropriate destination number, that is, the destination number associated with the recipient mobile station 345. In some instances, a SMS Router can be included in the mobile network, and typically sits in front of a SMSC. A short message can be transmitted from a MSC to the SMS Router which looks at the destination number and determines whether the short message should continue to the SMSC or be rerouted to a different SMSC (i.e., if the destination number is in a different network), or whether the destination is an address, e.g., an IP address for an application server, in which case the short message is routed to the application server without reaching the SMSC. In such an instance, the process described in reference to FIG. 5 would differ slightly in that the short message would be routed from the MSC 315 to the SMS Router to the location server 350, without first being routed to the SMSC 320. It should also be noted that the MSC 315 and the MSC 330 can be the same MSC if, for example, the sender mobile station 305 and the recipient mobile station 345 were both in locations being serviced by the same MSC when the short message originated from the sender mobile station 305. In the above example of including a location of a sender mobile station in a short message, a location server 350 was used to determine the location and modify the short message. However, the steps performed by the location server 350 can be performed by a SMSC or some other entity along the transmission path of the short message. An advantage of using a location server is that a short message can be modified to include a location of the sender without requiring a software or hardware upgrade of the wireless network elements, including the SMSC. The SMSC can process a short message that includes a location request without awareness of the location request, and the short message can be seamlessly diverted to and received back from the location server with the location of the sender added thereto. Additionally, mobile users can use the location request service with a mobile station, e.g., a mobile telephone, that is two-way SMS capable without requiring any upgrades to the mobile station. Referring to FIG. 7, a process 700 for modifying a short message to include a location of the sender mobile station 305 is shown that includes at least one additional step, performed in the illustrated implementation by the location server 350. The location server 350 receives the short message from the SMSC 320 (or an SMS Router as the case may be), the short message including the location-request code added to a destination number (step 710). The location server 350 determines a location of the sender mobile station 305 (step 715), modifies the short message to include the location (step 720) and further modifies the short message to remove the location-request code from the destination number (step 725). The location server 350 can determine if the recipient mobile station 345 associated with the destination number is “location-enabled” (step 730). That is, the location server 350 can determine whether a short message originating from the recipient mobile station 345 can include a location-request, which location-request can be satisfied by a mobile network used by the recipient mobile station 345 (e.g., whether the recipient mobile station has subscribed to a “location-enabled” service). If the recipient mobile station 345 is location-enabled (“Yes” branch of decision step 730), then the location server 350 further modifies the short message to add a location-request code to the sender's number (which sender's number was included in the original short message) (step 735). If the recipient mobile station 345 is not location-enabled (“No” branch of decision step 730), then no further modifications are made to the short message. The location server 350 then transmits the modified short message back to the SMSC 320 (step 740). The location server 350 can determine whether the recipient mobile station 345 is location-enabled using any convenient means. In one implementation, a user of the recipient mobile station 345 can create a user profile in a database that is accessible by the location server 350. For example, the user can complete a user profile form on a webpage, which form is used to create a database record associated with the user. Included in the user profile will be information as to whether or not the user is a subscriber to a location-enabled service. The location server 350 can determine from the user profile whether or not the recipient mobile station 345 is location-enabled. In another example, the user profile may provide information, such as the user's account number with a mobile subscription service and an address for the mobile subscription service, and the location server can query the mobile subscription service to determine whether or not the user subscribes to a location-enabled service. The sender's number is typically included in any short message originating from the sender mobile station 305 so that a recipient mobile station can reply to the short message, and have the reply automatically routed back to the sender's number. If the location-request code is added to the sender's number, then when the recipient mobile station 345 replies to the modified short message, the “destination number” for the reply short message includes the location-request code. When the reply short message is received by a SMSC, the location-request code will trigger the process described above in relation to FIGS. 5 and 6. That is, the SMSC will determine the location of the recipient mobile station 345 (now the short message originator) and modify the reply short message to include the location of the recipient mobile station 345. In the exemplary process described above, a location server determined whether the recipient mobile station 345 was location-enabled and, if so, modified the short message to add a location-request code to the sender's number. However, this function can be performed by a SMSC or other entity along the transmission path of the short message. The step 730 of determining whether a recipient mobile station is location enabled can be eliminated, and the short message automatically can be modified to include a location-request code at the beginning of the sender's number. However, the additional service of having a location included in a short message may be implemented as a value-added service for which a mobile subscriber must pay an extra fee, for example, a monthly flat fee or a per message fee. Under such conditions, the additional step 730 facilitates ensuring that only paying mobile subscribers benefit from the service. The example of processing a short message described above in reference to FIG. 3 was illustrated using a simplified transmission path. One skilled in the art will recognize that a short message may be transmitted to a first SMSC and, if the destination number is not in the mobile network serviced by the first SMSC, an appropriate second SMSC in a different mobile network can be identified, e.g., using look-up tables, and the short message routed to the second SMSC. Alternatively, as mentioned above, the process of identifying an appropriate SMSC and rerouting of the short message can be performed by a SMS Router that intercepts the short message before the message reaches the first SMSC, or which is included within the SMSC. The example described a short message sent between two mobile stations 305 and 345. However, the short message may be sent between a mobile station and a SME that is not a mobile station, for example, an e-mail address or an IP address of an application server. The processes and systems described above to include a location in a short message can be implemented in other messaging services. For example, the location of a sender mobile station from which a multi-media message originates can be included in the multi-media message. Referring to FIGS. 8 and 9, a multi-media message can originate from a sender mobile station 805. The multi-media message includes a destination number associated with a recipient, in this example, a recipient mobile station 845. A location-request code can be included in the multi-media message using similar techniques described above in reference to short messages. That is, a user can include prefix digits before the destination number, such as “99”, indicating that the user wants the location of the sender mobile station 805 to be included in the multi-media message delivered to the recipient mobile station 845. The multi-media message is transmitted from the sender mobile station 805 to a base-station system 810, to a mobile switching center 815 and finally to a multi-media messaging service center (MMSC) 820 (step 905). Alternatively, a MMS Router can intercept the multi-media message before the message reaches the MMSC 820, or the MMSC 820 can include a MMS Router. In this example, the MMSC 820 determines whether the destination number is in the mobile network serviced by the MMSC 820, for example, by looking up the destination number in a look-up table. Because the location-request code 99 has been added to the beginning of the destination number associated with the recipient mobile station 845, the MMSC 820 will determine from the look-up table that an address of an application server is associated with the location-request code (i.e., the 99). The address can be the address of the location server 850, and the MMSC 820 delivers the multi-media message to the location server 850 (step 910). The location server 850 determines the sender's number from the multi-media message and determines the current location of the sender mobile station 805 associated with the sender's number (step 915). The location server 850 can use similar techniques described above in reference to short messaging, for example, by querying a LES 855. The location server 850 modifies the multi-media message to include the location of the sender mobile station 805 (step 920) and transmits the modified multi-media message to the MMSC 820 (step 925), or alternatively can send the modified multi-media message to a different MMSC, if the destination number is a network that is not serviced by the MMSC 820. The location server 850 can remove the location-request code from the destination number, such that the MMSC 820 can parse the modified multi-media message to retrieve the destination number associated with the recipient mobile station 845, and route the modified multi-media message accordingly. The modified multi-media message routes from the MMSC 820 to a MSC 830 (which in some instances can be the same as MSC 815), to a base-station system 840 and finally to the recipient mobile station 845 (step 930). As discussed above in the context of short messaging, some or all of the steps performed by the location server 850 can be performed by a MMSC 820 or other network element directly or indirectly in the transmission path of a multi-media message. In another implementation, a location-request code included in a multi-media message can trigger the MMSC 820 to determine the location of the sender mobile station 805 and modify the multi-media message to include the location. If the recipient mobile station 845 is not MMS-enabled, then the multi-media message can be modified to include the location of the sender mobile station 805 before storing the multi-media message on an Internet accessible server and transmitting a corresponding notification message to the recipient mobile station 845. If the recipient mobile station 845 is MMS-enabled and the content of a multi-media message can be sent directly to the recipient mobile station 845, then the modified multi-media message is sent to the recipient mobile station 845. An additional step, which can be performed by the location server 850 or some other network element, to add a location-request code to the sender's number within the multi-media message can be performed, using similar techniques as discussed above. Referring to FIG. 10, a sender mobile station 1005 can address a multi-media message to a recipient 1030 that is not a mobile station, for example, an e-mail address. The multi-media message is transmitted from the sender mobile station 1005 to a base-station system 1010, to a mobile switching center 1015 and finally to a MMSC 1020. The MMSC routes the multi-media message to an e-mail server 1025, which e-mail server 1025 delivers the multi-media message to the recipient e-mail address 1030. Referring to FIG. 11, a user of a sender mobile station 1105 can include a location-request in a multi-media message for delivery to a recipient e-mail address 1140, rather than a recipient mobile station. In this implementation, the multi-media message is modified to include the location of the sender mobile station 1105 by a location server 1125, although another network element, such as the MMSC 1120, can perform this step. In the implementation where an entity other than the MMSC 1120 is modifying the multi-media message, such as the location server 1125, then in order for the multi-media message to be routed to the location server 1125, the multi-media message is initially transmitted to an address associated with the location server 1125, rather than the recipient e-mail address 1140. Referring to FIG. 12A, in one implementation the multi-media message can be initially delivered to the location server 1125 and then rerouted to the recipient e-mail address 1140 as follows. The user of the sender mobile station 1105 can create a user profile that is stored in a location, such as a web server or a database, that is accessible by the location server 1125 (Step 1205). For example, the user can access a website over the Internet that provides a web page for creating a user profile. The user inputs information prompted by the web page, thereby creating the user profile, which may be stored as a database record. The user profile may include definitions of “handles” (i.e., aliases) for potential recipients of multi-media messages originating from the user's mobile station. For example, a handle for an e-mail address of newman@xyzcompany.com may be “newman-xyz”. The web page prompts the user to define handles for e-mail addresses the user may wish to send multi-media messages to from the user's mobile station (step 1210). The handle definitions are stored as part of the user profile, and therefore also accessible by the location server 1125. A sender, such as the user referred to above, creates a multi-media message, for example, by taking a digital photograph with the sender's mobile telephone, which is intended for delivery to newman@xyzcompany.com (step 1215). However, rather than input the newman@xyzcompany.com e-mail address as the destination number for the multi-media message, the sender inputs an e-mail address that will direct the multi-media message to the location server 1125 (step 1220), which e-mail address includes the handle associated with the recipient e-mail address, i.e., the handle “newman-xyz”. For example, the sender can input the following e-mail address: newman-xyz@locationserver.com (i.e., handle@locationserver.com). The multi-media message will route from the sender's mobile station 1105 to a BSS 1110, to a MSC 1115 and to the MMSC 1120. The MMSC 1120 will route the multi-media message to an application server associated with the e-mail address, which in this case is the location server 1125. Referring to FIG. 12B, when the location server 1125 receives the multi-media message (step 1225), the location server 1125 parses the multi-media message to determine the sender's number. The location server 1125 determines the current location of the sender's mobile station 1105, for example, by sending a request to a location-enabled server 1127 requesting the location of a mobile station associated with the sender's number, using similar techniques as described above (step 1230). The location server 1125 modifies the multi-media message to include the location of the sender's mobile station 1105 (step 1235). The modified multi-media message can be routed to the recipient e-mail address 1140. The multi-media message included destination information, in this instance, the handle associated with the recipient e-mail address was included in the original destination number, i.e., the e-mail to which the multi-media message was originally sent. The location server 1125 retrieves the user profile 1130 associated with the sender's number, and determines from the user profile an e-mail destination address associated with the handle provided by the destination information (step 1240). That is, the sender addressed the multi-media message to newman-xyz@locationserver.com, thereby indicating that the handle of the recipient e-mail address is newman-xyz. The location server 1125 determines from the sender's user profile that newman-xyz is a handle for newman@xyzcompany.com, which is therefore the recipient e-mail address 1140. The location server 1125 sends the modified multi-media message to the recipient e-mail address 1140 (i.e., destination address) (step 1245). The modified multi-media message may be routed first to an e-mail server 1135 and then delivered to the recipient e-mail address 1140. In one implementation, the multi-media message can be further modified to include a location-request code before the sender's number, so that a reply message is sent to the sender with the location of the recipient included therein, using similar techniques as described above in reference to SMS. In another implementation, the sender mobile station 1105 can include the corresponding user profile, which includes the handle definitions. The sender can request that the location of the sender mobile station 1105 be included in a multi-media message, for example, by inputting a location-request code into the sender mobile station 1105 or setting the mobile station 1105 to automatically request the location be included in all such messages. The sender can specify the recipient e-mail address by either entering the entire e-mail address or entering the handle. The sender mobile station 1105 can automatically route the multi-media message to the appropriate e-mail address, e.g., handle@locationserver.com. This technique may require upgrades to the sender mobile station 1105, but can facilitate the sender's experience. The above example is illustrative, and describes one technique for routing a multi-media message to a location server for modification to include a location, and then rerouting to a final destination e-mail address. Other techniques can be used. Additionally, the multi-media message can be modified to include a location by a location server, as described, or by another network element, for example, the MMSC. An MMSC 820 can determine from a destination number a format for a multi-media message that is compatible with the recipient associated with the destination number, and convert the multi-media message into the format before delivering the message to the recipient. Thus, an MMSC 820 may determine a format for the multi-media message that is compatible with the location server 850 (i.e., the recipient associated with the destination number, based on the 99 included before the recipient destination number), and the MMSC 820 may deliver the multi-media message to the location server 850 in the determined. In one implementation, the location server 850 determines a format for the multi-media message that is compatible with the recipient based on the destination number associated with the recipient and, if necessary, changes the format of the modified multi-media message to the determined format before transmitting the modified multi-media message to an MMSC 820 or e-mail server 1025. The techniques described above for determining a location of a sender of a short message or a multi-media message can be implemented for other messaging services using similar techniques. For example, the techniques can be implemented for Smart Messaging, Enhanced Messaging Services and using iMode available in Japan. A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. The logic flows depicted in FIGS. 2, 4-7, 9, 12A and 12B do not require the particular order shown, or sequential order, to achieve desirable results, and the steps of the invention can be performed in a different order and still achieve desirable results. Accordingly, other embodiments are within the scope of the following claims. | <SOH> BACKGROUND <EOH>The following disclosure relates to processing a message, such as a short message or a multi-media message. Short messaging service (SMS) is a globally accepted service for transmitting short messages between wireless devices. Typically a “short message” is 160 alpha-numeric characters or less, and can be transmitted between mobile subscribers, e.g., using mobile telephones, over a wireless network or between a mobile device and a system external to the wireless network, such as application server for handling electronic mail or paging. SMS uses the mobile application protocol (MAP) which, in the mobile network context, is an application layer protocol designed to support database interrogation and mobility management, and uses the services of the SS7 (Signalling System No.7) transaction capabilities application part (TCAP). The American and the international standards bodies have defined a MAP layer using the services of the SS7 TCAP: the American standard is published by the Telecommunication Industry Association and is referred to as IS-41, and the international standard is defined by the European Telecommunication Standards Institute and is referred to as GSM (global standard for mobiles) MAP. Some additional protocols used in short messaging include the Short Message Peer to Peer (SMPP) protocol, an open industry standard messaging protocol designed to simplify integration of data applications with wireless mobile networks, and the Universal Computer Protocol (UCP). A short messaging entity (SME) is an entity which may receive or send short messages, and may be located in a fixed network or a wireless network. For example, a SME can be a mobile station (MS), such as a mobile telephone, that sends and receives messages over a wireless network. A different example of an SME is a personal computer used to receive short messages into an e-mail account via an e-mail server that communicates with a wireless network. Referring to FIG. 1 , a base station system (BSS) 110 receives a short message transmitted from a mobile station (MS) 105 . For example, the mobile station 105 can be a mobile telephone, and a user can input the short message using a user interface on the mobile telephone, and include a destination number that is associated with a recipient mobile station 145 , i.e., a telephone number. Abase-station system 110 typically consists of base-station controllers and base-transceiver stations and is responsible for transmitting voice and data traffic between mobile stations. The base-station system 110 transmits the short message to a mobile switching center (MSC) 115 . The mobile switching center 115 performs switching functions for a mobile system and controls calls to and from other telephone and data systems; typically a MSC 115 services multiple base-station systems. The short message is routed from the mobile switching center 115 to a short messaging service center (SMSC) 120 . The SMSC 120 is responsible for the relaying and store-and-forwarding of a short message between short message entities, including mobile stations. The SMSC 120 makes a determination based on the destination number, for example, using a look-up table, whether the short message should be rerouted to a different SMSC or whether routing information for the short message can be obtained by the SMSC 120 from a home location register (HLR) 125 . For the sake of simplicity, in this example, the SMSC 120 determines that routing information can be obtained from the HLR 125 , and proceeds to interrogate the HLR 125 for the routing information. An HLR 125 is a database used for permanent storage and management of subscriptions and service profiles of network users. The routing information provided by an HLR 125 is at the “MSC level”, meaning an HLR 125 can provide information as to which MSC in a wireless network to which to route the short message so that it can be routed to a recipient mobile station 145 associated with the destination number. Based on the routing information, the SMSC 120 transmits the short message to a MSC 130 that is presently servicing the recipient mobile station 145 (i.e., as the recipient mobile station 145 moves through the network, the MSC that is presently servicing the mobile station 145 can change). The MSC 130 interrogates a visitor location register (VLR) 135 , which is a database that contains temporary location information about network users that are currently in the area of a base station serviced by the MSC 130 . That is, the location information in the VLR 135 is at the base station transceiver (i.e., cell tower) level, as compared to the routing information provided by the HLR 125 , which is at the MSC level. Based on information received from the VLR 135 , the MSC 130 routes the short message to a base-station system 140 and from there the short message is delivered to the recipient mobile station 145 . Delivery of the short message to the recipient mobile station 145 is based on the destination number input by the user of the sender mobile station 105 . In addition to the destination number, the short message typically includes a sender number, that is, a number that is associated with the sender mobile station 105 , such as the sender's mobile telephone number. The recipient mobile station 105 can reply to the short message, which reply is automatically routed to the sender mobile station 105 based on the sender number included in the original short message, similar to an e-mail user clicking on the “reply” button when replying to an e-mail message. The reply short message is routed to the sender mobile station 105 using the same steps described above to route the original message to the recipient mobile station 145 . Multi-media messaging service (MMS) is similar to SMS, except that in addition to text, multi-media messages can include graphics, audio, images and video. A multi-media message can be transmitted from a sender mobile station 105 to a recipient mobile station 145 in a similar manner as an SMS, except that the SMSC 120 is replaced by a multi-media messaging center (MMSC), which provides corresponding functions for multi-media messages. In some instances, for example, if the recipient mobile station 145 is not MMS-enabled, the MMSC stores the content of the multi-media message and sends a short message, referred to as a “notification message”, to the recipient mobile station 145 advising the recipient mobile station 145 that there is a multi-media message available for the recipient to retrieve from a location provided in the notification message as a link, for example, to a URL. A user of the recipient mobile station 145 can click on the link and retrieve the content of the multi-media message from the location, which may be a server included in the MMSC. A recipient of a multi-media message can be an e-mail address, in which case the MMSC routes the multi-media message to an application server, i.e., an e-mail server. MMS is a global service and also uses various well known protocols and standards. | <SOH> SUMMARY <EOH>The following describes apparatus and techniques relating to messages, such as short messages and multi-media messages. In general, in one aspect, the invention features a method of processing a message, including the steps of receiving a message from a sender, determining a location of the sender, modifying the message to include the location of the sender, and transmitting the modified message to a recipient. Implementations may feature one or more of the following. The message can be, for example, a short message or a multi-media message. The message can include a request to include the location of the sender in the message. The request can be a location-request code added to a destination number included in the message. Transmitting the modified message to a recipient can include transmitting the modified message to a recipient associated with the destination number. The message can be transmitted to a location server, based on the location-request code, and the location server can perform the steps of determining a location of the sender and modifying the message to include the location of the sender. The location server can further modify the message to remove the location-request code from the destination number. Determining a location of the sender can include sending a request (e.g., from the location server) to a location-enabled server and receiving a location of the sender from the location-enabled server. Alternatively, a location of the sender can be retrieved from a cache of location information. Retrieving a location for the sender from a cache of location information can include: receiving location information from multiple network probes about locations of multiple network users including the sender; periodically caching the location information for the network users; and retrieving a location for the sender from the cache of location information. The message can be further modified to add a location-request code to a sender number included in the message, where the location-request code is a request to include the recipient's location in a reply message to the message. Modifying the message to add a location-request code to a sender number can include determining if a location of the recipient can be included in a message originating from the recipient, and if a location of the recipient can be included, then modifying the message. In general, in another aspect, the invention features a method of processing a message, including the steps of receiving a message from a first messaging service center, determining a location of a sender of the message, modifying the message to include the location of the sender, and transmitting the modified message to a second messaging service center. Implementations can include one or more of the following. The message can be a short message, and the first messaging service center and the second messaging service centers can be short messaging service centers. Alternatively, the message can be a multi-media message, and the first messaging service center and the second messaging service centers can be multi-media messaging service centers. The first messaging service center and the second messaging service center can be the same messaging service centers. The first messaging service center can service a mobile network used by a sender of the message, and the second messaging service center can service a mobile network used by a recipient of the message. The message can include a location-request code added to a destination number, and before transmitting the modified message to the second messaging service center, the message can be further modified to remove the location-request code from the destination number. Determining a location of the sender can include sending a request to a location-enabled server and receiving a location of the sender from the location-enabled server. Alternatively, determining a location of the sender can include retrieving a location for the sender from a cache of location information. Retrieving a location from a cache of location information can include receiving location information from multiple network probes about locations for multiple network users including the sender, periodically caching the location information for the network users, and retrieving a location for the sender from the cache of location information. In general, in another aspect, the invention features, a method of processing a message including the steps of inputting a message into a mobile station, inputting into the mobile station a location-request code and a destination number, where the location-request code specifies a request to modify the message to include a location of the mobile station in the message and where the destination number specifies a destination for delivery of the message, and transmitting the message from the mobile station to a messaging service center. In one implementation the message can be a short message, and in another implementation the message can be a multi-media message. In general, in another aspect, a system for processing a message features a sender mobile station, a messaging service center, a location server and a recipient messaging entity. The sender mobile station is configured to receive a user input and based on the user input transmit a message over a mobile network for delivery to a recipient messaging entity associated with a destination number, where the message includes a request to include a location of the sender mobile station in the message. The messaging service center is configured to receive from a sender mobile station a message including a request to include a location of the sender mobile station in the message, transmit the message to a location server, receive a modified message from a location server, transmit the modified message to a recipient messaging entity. The location server is configured to receive a message from a messaging center, the message including a request to include a location of a sender mobile station in the message; determine a location of the sender mobile station; modify the message to include the location; and transmit the modified message to a messaging center. The recipient messaging entity is configured to receive a message including a location of a sender mobile station from which the message originated. Implementations can include one or more of the following. The message can be a short message, and the messaging service center can be a short messaging service center. Alternatively, the message can be a multi-media message, and the messaging service center can be a multi-media messaging service center. In general, in another aspect, a method of processing a multi-media message includes the steps of receiving a multi-media message originating from a sender mobile station, the multi-media message including destination information; determining a location of the sender mobile station; modifying the multi-media message to include the location of the sender mobile station; and transmitting the modified multi-media message to a recipient based on the destination information. Implementations can include one or more of the following. The transmitting step can further include accessing a user profile associated with the sender mobile station; based on the user profile and the destination information, determining an e-mail address associated with the recipient; and transmitting the modified multi-media message to the recipient e-mail address. Determining a location of the sender mobile station can include querying a location enabled server for a location of the sender mobile station, and receiving a location of the sender mobile station from the location enabled server. Alternatively, determining a location of the sender mobile station can include retrieving a location for the sender mobile station from a cache of location information. Retrieving a location for the sender mobile station from a cache of location information can include receiving location information from multiple network probes about locations for a multiple network users including the sender mobile station, periodically caching the location information for the network users including the sender mobile station, and retrieving a location for the sender mobile station from the cache of location information. Implementations of the invention can realize one or more of the following advantages. A current location of a sender mobile station can automatically be included in a message, such as a short message or multi-media message, originating from the sender mobile station. A location server can be used to determine a location of a sender mobile station and modify a message to include the location without requiring a software or hardware upgrade of mobile network elements, such as a short messaging service center or a multi-media messaging center. The short messaging service center or multi-media messaging center can process a short message or multi-media message that includes a location request without awareness of the location request, and the message can be seamlessly diverted to and received back from a location server with the location of the sender mobile station added thereto. Mobile users can use the location request service with a mobile station, e.g., a mobile telephone or other such handset, that is two-way SMS or MMS capable without requiring any upgrades to the mobile station. A user of a sending device can decide on a message-by-message basis whether to include a request to add the location of the sending device to a message originating from the sending device. The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. | 20040223 | 20081202 | 20050825 | 63485.0 | 1 | VU, MICHAEL T | LOCATION BASED MESSAGING | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,786,144 | ACCEPTED | Method and system for finding | A wireless system and method for determining the location of a fixed or mobile target configured to have a transponder on the target, a transceiver monitoring the target location, communicating between the transponder and transceiver, and a processor for finding the target by virtual triangulation based on values of received position information. The processor is determines virtual triangulation based on successive values of the position information using at least three points P1, P2 and P3 of the transponder respective of the transceiver. The present invention discloses methods for finding with virtual triangulation by: (1) finding with virtual triangulation by generating position information in real-time, in the case of (i) stationary and moving target, and or (ii) in the case of the presence of obstacles; (2) finding with virtual triangulation relating to the average speed of the motion of operator; and or (3) finding with simplified virtual triangulation. | 1. A system for finding a target, comprising: a transponder disposed on the target; a transceiver for monitoring the location of the target; a wireless communication system configured to allow communication between said transponder and said transceiver, and a processor configured to find the target by virtual triangulation based on values of position information from said transponder and said transceiver. 2. The system for finding of claim 1, wherein said processor being configured to determine virtual triangulation based on successive values of said position information using at least three points P1, P2 and P3 of said transponder respective of said transceiver. 3. The system for finding of claim 1, wherein said processor being configured to determine virtual triangulation based on successive values of said position information of said transponder respective of said transceiver using a means for successive pattern movement technique configured to find the target, whereby said means for successive pattern movement obtains and corrects the direction to the location of the target T based on said values of said position information. 4. The system for finding of claim 1, wherein said processor being configured to determine virtual triangulation based on successive values of said position information relating to the average speed of the motion of the user of said transponder respective of said transceiver. 5. The system for finding of claim 1, wherein said processor being configured to determine virtual triangulation based on successive values of said position information relating to input of a user of said transceiver, whereby said user input signals motion between said transponder respective of said transceiver begins. 6. The system for finding of claim 1, wherein said processor being configured to determine virtual triangulation based on successive values of the elapsed time a ranging signal transmitted by said transceiver to said transponder, said transponder transmitting a reply ranging signal to said transceiver, whereby said transceiver transmitting said ranging signal and receiving said reply ranging signals from said transponder a predetermined number of times sufficient to determine an elapsed time. 7. The system for finding of claim 1, wherein said processor being configured to accumulate a phase shift between said ranging signal and said reply ranging signal. 8. The system for finding of claim 1, wherein said processor being configured with a phase shift detector. 9. The system for finding of claim 8, wherein said processor being configured to determine a value of an optimal operating resolution of said phase shift detector. 10. The system for finding of claim 8, wherein said phase shift detector is configured to measure a value of said phase shift between said ranging signal and said reply ranging signal. 11. The system for finding of claim 8, wherein said processor being configured to determine a value of said phase shift based on a value of a transmission interval. 12. The system for finding of claim 8, wherein said processor being configured to determine a value of said phase shift based on a value of a calibration interval. 13. The system for finding of claim 12, wherein said value of said calibration interval is periodically determined by each of said transponder and or said transceiver. 14. The system for finding of claim 8, wherein said processor determines said phase shift based on a value of an antenna propagation interval. 15. The system according to claim 1,.wherein said transceiver is configured to enter a homing mode for searching for the target, said homing mode being entered when a value of said position information between said transceiver and the target corresponds to a predetermined value. 16. The system according to claim 15, wherein said homing mode toggled between states of on and off by a value of said position information of the target being equal to a predetermined value of a position ambiguity of the target. 17. The system according to claim 16, wherein said transceiver is configured to exit said homing mode after an elapsed predetermined time period. 18. The system according to claim 16, wherein said transceiver is configured to enter said homing mode to determine a location of the target when requested by input from a user. 19. The system according to claim 1, wherein said processor is configured to reduce position ambiguity of transceiver respective of the target based on generating a value for input information signals on at least one band. 20. The system according to claim 19, wherein said transceiver is configured to generate auditory signals representative of when said position ambiguity of the target is equal to a predetermined value for said position ambiguity. 21. The system according to claim 1, wherein said processor is configured to operate on a band using on a spread spectrum to establish position information signals from said transponder and said transceiver. 22. The system according to claim 1, wherein said transceiver being configured with an interface with the user so as to communicate to the user through said interface by one or more of the sensing group of audible, visual or physical. 23. The system according to claim 22, wherein said interface includes a display for visually displaying said position information to the user. 24. The system according to claim 23, wherein said display includes is LCD screen having means for indicating said position information to the user. 25. The system according to claim 22, wherein said interface includes indicator means configured to display said position information to the user on a predetermined pattern. 26. The system according to claim 2, wherein said values from said three points P1, P2 and P3 create a point of intersection of circles based on circles with radii R1, R2 and R3 originating from said points P1, P2 and P3, respectively, whereby said point of intersection finds the target respective of said transceiver. 27. The system according to claim 1, wherein said transceiver is configured to adjust adaptively a power value of a transmitter of said transceiver so as to improve a value of said position information. 28. The system according to claim 1, wherein said transceiver is configured to adjust adaptively a sensitivity value of a receiver of said transceiver so as to improve a value of said position information. 29. The system according to claim 1, wherein said transponder is configured to adjust adaptively a power value of a transmitter of said transponder so as to improve a value of said position information. 30. The system according to claim 1, wherein said transponder is configured to adjust adaptively a sensitivity value of a receiver of said transponder so as to improve a value of said position information. 31. The system according to claim 1, wherein said processor being configured to be in communication with an antenna, said processor being configured to repeatedly determine values for said position information based on one or more of the following values for: a transmission interval between said transceiver and said transponder, said transmission interval being an elapsed time between transmitting said ranging signal and receiving said reply ranging signal, a calibration interval between each of said transceiver and transponder said calibration interval being a time interval of a period to normalize the circuitry of said transponder and said transceiver, and an antenna propagation interval of either of said transceiver or said transponder, or both, said antenna propagation interval being an elapsed time of a signal measured as it passes through said antenna of said transponder or said transceiver. 32. The system according to claim 1, wherein said processor is configured for communication with an antenna to repeatedly determine values for said position information based on a value for a measured distance between said transponder and said transceiver. 33. The system according to claim 1, wherein said transceiver is configured for transmitting a ranging signal to said transponder, said transponder is configured for responding to said ranging signal by transmitting a reply ranging signal to said transceiver, and said processor is configured to determine a value of a measured distance between said transponder and said transceiver based on position information from said ranging signal and said reply ranging signal. 34. A method, comprises the steps of: determining a value of a point P1 from position information received by a transceiver corresponding to a location of a transponder disposed on a target; prompting said user to move said transceiver to a point P2 relative to a location of the target; determining a value of a point P2 from position information received by said transceiver corresponding to a location of said transponder; prompting said user to move said transceiver to a point P3 relative to a location of the target; determining a value of a point P3 from position information received by said transceiver corresponding to a location of said transponder; and finding the location of the target by virtual triangulation in accordance with each of said values for said points P1, P2 and P3 of position information received by said transceiver. 35. The method of claim 34 wherein said step of determining said position information further comprises repeating as necessary the steps of: prompting a user to move said transceiver to a point Pn relative to a location of said target having said transponder; determining a value of a point Pn from position information received by said transceiver corresponding to a location of said transponder; and finding the location of the target from position information received by said transceiver by repeating said determining by virtual triangulation for two of each of said values for said points P1, P2 or P3 and said point Pn. 36. The method of claim 34 wherein said step of determining said position information further comprises the steps of: determining said values of said position information of said target by: determining a transmission interval between said transceiver and said transponder; determining a calibration interval between each of said transceiver and transponder; and determining an antenna propagation interval of each of said transceiver and transponder. 37. The method of claim 36 wherein said step of determining said position information further comprises the steps of: determining said transmission interval based on an elapsed time between transmitting said ranging signal and receiving said reply ranging signal. 38. The method of claim 36 wherein said step of determining said position information further comprises the steps of: determining said calibration interval based on a time interval of a period to normalize the circuitry of said transceiver and said transponder. 39. The method of claim 36 wherein said step of determining said position information further comprises the steps of: determining said antenna propagation interval based on an elapsed time of a signal measured passing through said antenna of said transceiver and said transponder. 40. The method of claim 36 wherein said step of determining said position information further comprises the steps of: generating a measured distance between each of said transceiver and said transponder. 41. The method of claim 40 wherein said step of determining determining said measured distance further comprises the steps of: determining said position information of the target generated by a virtual triangulation relationship when successive values of said position information have a predetermined logical relationship relative to said previous values between said transceiver and said transponder. 42. The method of claim 36 wherein said step of determining said position information further comprises the steps of: generating a measured distance between each of said transceiver and said transponder. 43. A computer-readable medium having stored thereon a plurality of sequences of instructions, said plurality of sequences of instructions including sequences of instructions which, when executed by a processor, cause said processor to perform the steps of: determining a value of a point P1 from position information received by a transceiver corresponding to a location of a transponder disposed on a target; prompting said user to move said transceiver to a point P2 relative to a location of the target; determining a value of a point P2 from position information received by said transceiver corresponding to a location of said transponder; prompting said user to move said transceiver to a point P3 relative to a location of the target; determining a value of a point P3 from position information received by said transceiver corresponding to a location of said transponder; and finding the location of the target in accordance with each of said values for said points P1, P2 and P3 of position information received by said transceiver. 44. A computer-readable medium having stored thereon a plurality of sequences of instructions, said plurality of sequences of instructions including sequences of instructions which, when executed by a processor, cause said processor to perform the steps of: determining successive values of position information of a transceiver respective of a transponder disposed on a target; finding using virtual triangulation the location of the target T based on said values of said position information, and correcting position ambiguity of the location of the target based on said values of said position information. 45. A computer-readable medium having stored thereon a plurality of sequences of instructions, said plurality of sequences of instructions including sequences of instructions which, when executed by a processor, cause said processor to perform the steps of: determining successive values of position information of a transceiver respective of a transponder disposed on a target; and finding using virtual triangulation the location of the target T based on said values of said position information based on successive values of said position information relating to the average speed of the motion of the user of said transponder respective of said transceiver. 46. A computer-readable medium having stored thereon a plurality of sequences of instructions, said plurality of sequences of instructions including sequences of instructions which, when executed by a processor, cause said processor to perform the steps of: determining successive values of position information of a transceiver respective of a transponder disposed on a target; finding using virtual triangulation the location of the target T based on successive values of said position information relating to input of a user of said transceiver, whereby said user input signals motion between said transponder respective of said transceiver begins. 47. A portable device for tracking a target, comprising: processor for determining position information of the target, memory operabaly connected to said processor, wherein said memory being configured to store a plurality of sequences of instructions, said plurality of sequences of instructions including sequences of instructions which, when executed by said processor, cause said processor to perform the steps of: determining a value of a point P1 from position information received by a transceiver corresponding to a location of a transponder disposed on a target; prompting said user to move said transceiver to a point P2 relative to a location of the target; determining a value of a point P2 from position information received by said transceiver corresponding to a location of said transponder; prompting said user to move said transceiver to a point P3 relative to a location of the target; determining a value of a point P3 from position information received by said transceiver corresponding to a location of said transponder; and finding the location of the target by virtual triangulation in accordance with each of said values for said points P1, P2 and P3 of position information received by said transceiver. 48. The portable device of claim 47 wherein said processor further repeating as necessary the steps of: prompting a user to move said transceiver to a point Pn relative to a location of said target having said transponder; determining a value of a point Pn from position information received by said transceiver corresponding to a location of said transponder; and finding the location of the target from position information received by said transceiver by repeating said determining by virtual triangulation for two of each of said values for said points P1, P2 or P3 and said point Pn. 49. The portable device of claim 47 wherein said processor further executing the steps of: determining said values of said position information of said target by: determining a transmission interval between said transceiver and said transponder; determining a calibration interval between each of said transceiver and transponder; and determining an antenna propagation interval of each of said transceiver and transponder. 50. The portable device of claim 49 wherein said processor further executing the steps of: determining said transmission interval based on an elapsed time between transmitting said ranging signal and receiving said reply ranging signal. 51. The portable device of claim 49 wherein said processor further executing the steps of: determining said calibration interval based on a time interval of a period to normalize the circuitry of said transceiver and said transponder. 52. The portable device of claim 49 wherein said processor further executing the steps of: determining said antenna propagation interval based on an elapsed time of a signal measured passing through said antenna of said transceiver and said transponder. 53. The portable device of claim 49 wherein said processor further executing the steps of: generating a measured distance between each of said transceiver and said transponder. 54. The portable device of claim 53 wherein said processor further executing the steps of: determining said position information of the target generated by a Virtual triangulation relationship when successive values of said position information have a predetermined logical relationship relative to said previous values between said transceiver and said transponder. 55. A mobile system for tracking a target T, comprising: a unit disposed on the target T; a monitoring unit for monitoring the location of the target T; a wireless communication system operating on at least one Radio Frequency (RF) band, said wireless communication system being configured to allow communication between configured to allow communication between at least two monitoring units and the target T, and a processor configured to find the target T by virtual triangulation based on values of position information from said monitoring unit and said unit disposed on the target. T. 56. The mobile system according to claim 55, wherein said processor being configured to be in communication with an antenna, said processor being configured to repeatedly determine values for said position information from: a transmission interval between said monitoring unit and the target T, a calibration interval between each of said monitoring unit and the target T, and an antenna propagation interval of said monitoring unit and the target T. 57. The mobile system according to claim 56, wherein further comprising: means for generating values of a measured distance between units, said generating means determining said values of said measured distance between said monitoring unit and the target T based on a virtual triangulation relationship using said position information. 58. The mobile system according to claim 57, wherein said processor being configured to be in communication with an antenna, said processor being configured to repeatedly determine values for said position information from: a transmission interval between said monitoring unit and the target T, a calibration interval between each of said monitoring unit and the target T, and an antenna propagation interval of said monitoring unit and the target T. 59. The mobile system according to claim 56, wherein said transmission interval being an elapsed time between transmitting said ranging signal and receiving said reply ranging signal. 60. The mobile system according to claim 56, wherein said calibration interval being a time interval of a period to normalize the circuitry of said monitoring unit and the target T. 61. The mobile system according to claim 56, wherein said antenna propagation interval being an elapsed time of a signal measured as it passes through said antenna of said monitoring unit and the target T. 62. The mobile system according to claim 56, wherein said system being configured to generate said virtual triangulation from said position information from a plurality of monitoring units or units disposed on the target T. 63. The mobile system according to claim 56, further comprising a plurality of monitoring units being configured to generate said virtual triangulation from said position information based on values received from said monitoring unit, or said units disposed on the target T, or units adjacent the target T. 64. The mobile system according to claim 63, whereby said monitoring unit or said units disposed on the target T or units adjacent the target T, are linked dynamically so as to form a mobile network adapted to locate, track and determine the position of each of said plurality of units. 65. The mobile system according to claim 64, wherein said mobile network being configured to enable a coordinated search to intercept the target T. 66. The mobile system according to claim 65, wherein said monitoring unit of said mobile network configured having an indicator means adapted to illustrate to each of said monitoring units in a predetermined range, said indicator means configured to instruct respective monitoring units to move coordinately so as to converge on said target T based on said position information determined by said virtual triangulation relationship. 67. The mobile system according to claim 56, wherein said position information determines values for three points P1, P2 and P3 so as to create a point of intersection of circles with radii R1, R2 and R3 originating from said points P1, P2 and P3, respectively, whereby said point of intersection finds the target respective of each of said monitoring units. 68. The mobile system according to claim 56, wherein said processor being configured to determine virtual triangulation based on successive values of said position information using at least three points P1, P2 and P3 of said monitoring unit respective of said unit disposed on the target T. 69. The mobile system according to claim 56, wherein said processor being configured to determine virtual triangulation based on successive values of said position information of said transponder respective of said transceiver using a means for position ambiguity reduction (PAR) configured to find the target, whereby said PAR means obtains and corrects the direction to the location of the target T based on said values of said position information. 70. The mobile system according to claim 56, wherein said processor being configured to determine virtual triangulation based on successive values of said position information relating to the average speed of the motion of the user of said unit slave unit respective of said master unit. 71. The mobile system according to claim 56, wherein said processor being configured to determine virtual triangulation based on successive values of said position information relating to input of a user of said transceiver, whereby said user input signals motion based on slave unit respective of said master unit begins. 72. The mobile system according to claim 56, wherein said processor is configured to operate on a band using on a spread spectrum to establish position information signals from said slave unit respective of said master unit. 73. A computer-readable medium having stored thereon a plurality of sequences of instructions, said plurality of sequences of instructions including sequences of instructions which, when executed by a processor, cause said processor to perform the steps of: determining a value of a point P1 from position information received by a transceiver corresponding to a location of a transponder disposed on a target; prompting said user of a predetermined transceiver to move said predetermined transceiver to a point P2 relative to a location of the target; determining a value of a point P2 from position information of said predetermined transceiver corresponding to a location of said transponder; requesting said value of said point P2 of said predetermined transceiver; requesting a value of a point P3 corresponding to a location of said predetermined transceiver; and finding the location of the target in accordance with each of said values for said points P1, P2 and P3. 74. A system for finding a target, comprising: a tracked unit, said tracked unit being configured with a transponder and is disposed on the target; a monitoring unit, said monitoring unit being configured with a transceiver, said monitoring unit configured for monitoring and tracking the location of the target; a communication system configured to communicate between said transponder and said transceiver on radio frequency band, and whereby said monitoring device has means for generating a measured distance between said monitoring device and said tracked unit, said monitoring device has means for determining the monitoring and tracking of the location of the target by a virtual triangulation relationship without need for additional points of references. 75. The system for finding the target of claim 74, wherein said monitoring unit moves in a virtual triangulation pattern where successive movements of said monitoring unit are based on logical, algorithmic and mathematical relationships between said measured distance values between said monitoring unit and said tracked unit. 76. The system for finding the target of claim 74, wherein said monitoring unit includes means for generating a measured distance between locations of successive movements of said monitoring unit or between successive locations of said monitoring unit as input by the user. 77. The system for finding the target of claim 76, wherein said monitoring unit moves in a virtual triangulation pattern where successive movements of said monitoring unit are based on logical, algorithmic and mathematical relationships between said measured distance values between said monitoring unit and said tracked unit, and said distance values between said monitoring unit successive locations. 78. The system for finding the target of claim 77, wherein said monitoring unit generates visual and audio information prompts for said monitoring unit successive movement. 79. The system for finding the target of claim 78, wherein said monitoring unit generates visual and audio information that conveys said monitoring unit successive movements and said target movements, and said monitoring unit and said target relative location as well the bearing angle to the target. 80. The system for finding the target of claim 79, wherein said monitoring or tracked units are configured with GPS, compass or other position and/or direction determining devices. 81. The system for finding the target of claim 80, wherein said monitoring unit generates visual and audio information that conveys said monitoring unit and the target successive movements, relative location and or absolute location. 82. The system for finding the target of claim 80, wherein said monitoring unit generates visual and audio information that conveys said monitoring unit and the target successive movements, relative location and or absolute location. 83. The system for finding the target of claim 74, wherein any three said monitoring units are stationary and are not located on the same straight line. 84. The system for finding the target of claim 83, wherein said three stationary monitoring units can form a virtual system of coordinates in which the coordinates of the said three stationary monitoring units and the coordinates can be determined of all of the mobile monitoring units and targets that are within the communication range of said three stationary monitoring units. 85. The system for finding the target of claim 84, wherein said mobile monitoring unit generates visual and audio information prompts for said monitoring unit successive movement. 86. The system for finding the target of claim 85, wherein said mobile monitoring unit generates visual and audio information that conveys said virtual scaled coordinates together with said mobile monitoring unit and the target relative location, and successive movements of said mobile monitoring unit and said target, and said bearing angle from said mobile monitoring unit to the target, and said stationary monitoring units relative location. 87. The system for finding the target of claim 86, wherein the data processing is performed by any said monitoring unit, stationary or mobile, or in a distributed fashion. 88. The system for finding the target of claim 87, wherein said monitoring and tracked units are combined with GPS, compass or other position and/or direction determining devices. 89. The system for finding the target of claim 88, wherein each mobile or stationary monitoring unit is equipped with a compass. 90. The system for finding the target of claim 74 whereby an ambiguity zone is decreased by increasing a distance between each of points P1, P2 and P3, said distance is increased between two of said points P1, P2 or P3 from an approximate value of 1.75*E to 4*E to reduce said ambiguity zone formed between each of said tracked units, whereby E is a maximum error in said distance measured between two of said points P1, P2 or P3, a width of said ambiguity zone is equal to E, and a length of said ambiguity zone is less than 2*E. 91. The system for finding the target of claim 74, whereby an ambiguity zone is reduced by increasing a distance between each of points P1, P2 and P3, said distance is increased between two of said points P1, P2 or P3 from an approximate value of 1.9*E to 5*E to reduce an ambiguity zone formed between each of said tracked units, whereby E is a maximum error said distance measured between two of said points P1, P2 or P3, a width of said ambiguity zone is equal to E, and a length of said ambiguity zone is less than 2*E. 92. The system for finding the target of claim 91, whereby said system increases said distance measured between two of said points P1, P2 or P3 to a large distance reduces said ambiguity zone to a square having sides equal to E. 93. The system for finding the target of claim 74, whereby said monitoring unit is configured with a loop back mode, said loop back mode utilizes a value representing a data processing time correction, said value for data processing time correction is determined by sending an output signal to the input of a receiver from an output of the transmitter of said monitoring unit, whereby said processor of said monitoring unit sends test data to the input of an encoder and starts a timer, said processor receives said output signal from said input of said receiver and stops said timer, said processor compares said test data and said received signal for a validation, said processor computing a loop back elapsed time from said timer, and said processor further corrects said loop back elapsed time by adding either of said validation or said data processing time correction, or both. 94. The system for finding the target of claim 74, whereby said monitoring unit is configured with a loop back mode, said loop back mode utilizes an output signal sent from an output of a transmitter sent to an attenuator connected directly to the input of a receiver of said monitoring unit. 95. The system for finding the target of claim 74, wherein said monitoring unit includes an interface for audio communications and telemetry information exchange so as to communicate between each of master units in the system simultaneously or independently from the operation of a processor regarding said distance measurement. 96. The system for finding the target of claim 74, wherein an interface provides communications between said monitoring unit and said tracked unit in the system simultaneously or independently from the distance measurement operation. 97. The system for finding the target of claim 96, whereby said interface provides full duplex audio communications and telemetry information exchange between said monitoring unit and said tracked unit, or between a plurality of said monitoring units in the system. 98. An integrated circuit for a wireless system for locating and tracking a subject or object, comprising a receiver; a transmitter; a microprocessor having a common clock as a source of synchronization; whereby said receiver and transmitter together define an active transponder and the integrated circuit is preferably a monolithic single die integrated circuit including said receiver, said transmitter, and said microprocessor; said transponder supplies predetermined ranging signals to a data processor portion of said microprocessor, said transponder includes an encoder for encoding data for transmission by said transmitter, and said a receiver includes a decoder circuit for receiving and decoding signals received from said antennae, and said a data processor for determining interval and position information, said data processor comprising a digital signal processor (DSP), a voltage stabilizer, and a battery supervisor; and an antenna for propagating said ranging said signal. 99. The circuit of claim 98, wherein said data information and ranging signals determined from input signals are coupled through a band pass filter, a distance measurement unit, and said decoder. 100. The circuit of claim 99, further including a microphone coupled to an input of a summing amplifier through a low frequency amplifier, said low frequency amplifier having compression/pre-emphasis, a low pass filter and an analog switch, said analog switch is operated by said DSP to enable a user to send voice communications when a monitoring or master unit is operating in a voice mode. 101. A method of a dynamic, mobile network for tracking and locating a plurality of monitoring units and targets T, comprising: tracking a primary target T with a primary monitoring unit having a predetermined range; determining when said target T moves out of said predetermined r ange; sending a ranging signal to at least one secondary monitoring unit within said predetermined range; receiving a reply ranging signal from at least one of said secondary monitoring unit; sending a request for a list of identified targets T to said secondary monitoring unit within a range of said secondary monitoring unit; receiving said list of identified targets T from said secondary monitoring unit; comparing said list of identified targets T to said primary target T; matching said primary target to one of said list of identified targets T from said secondary monitoring unit; and determining the location of the primary target from position information provided by said secondary monitoring unit. 102. A method of a dynamic, mobile network as in claim 101, comprising the additional step of: transferring tracking of said primary target to said secondary monitoring unit having said primary target in range. 103. A method for finding a target, comprising the steps of: determining a point P1 by having a user make an input to a monitoring unit; transmitting a ranging signal from said monitoring unit; receiving a reply ranging signal from a slave unit located on a subject or on an object at a point T, where said point T is located out of a range of said master unit; entering a homing mode on said monitoring unit; prompting said user to select a direction and having said user move in said direction along a path “Delta (1)” in a direction towards a point P2; actuating a step button on said monitoring unit to input once for each step taken by said user to generate reference points for a virtual triangulation calculation; prompting said user through said master unit to stop data input of said step button when said user reaches said point P2 determining using a processor of said monitoring unit whether the distance between subsequent points Delta (n) is equal or greater than (4−5)*E such that a value of said path Delta (1) is sufficiently large to minimize the a position ambiguity of said target T. 104. The method for finding a target of claim 103, further comprising the step of: prompting said user after reaching point P1 randomly to go either right or left from said Point P1 to a point P2 in a direction away from said target T. 105. The method for finding a target of claim 104, further comprising the step of: actuating a step button on said monitoring unit to input once for each step taken by said user going to point P2 in a direction away from said target T to generate reference points for a virtual triangulation calculation. 106. The method for finding a target of claim 105, further comprising the step of: prompting said user after reaching point P2 randomly to go either right or left from said Point P2 along a path “Delta (2)” to a point P3 in a direction away from said target T. 107. The method for finding a target of claim 106,, further comprising the step of: actuating a step button on said monitoring unit to input once for each step taken by said user going to point P3 in a direction away from said target T to generate reference points for a virtual triangulation determination. 108. The method for finding a target of claim 107, further comprising the step of: determining a Delta (n) using a current reference unit pre-programmed in said processor and calculating said Delta (n), which is equal to the difference (P(n−1)−current position). 109. The method for finding a target of claim 108, further comprising the step of: prompting said user after determining said Delta (n) to move in a direction toward the target T. 110. The method for finding a target of claim 109, further comprising the step of: prompting said user repeatedly along successive points P(n) in a direction toward the target T using virtual triangulation, and entering a homing mode upon approaching said target T after determining said Delta (n) to move in a direction toward the target T, wherein said master unit prompts said user. 111. The method for finding a target of claim 110, further comprising the step of: requesting said slave unit to generate an audible signal upon approaching said target point T in said homing mode within a predetermined range, and generating an audible signal using said slave unit. 108. The method for finding a target of claim 111, further comprising the step of: requesting said slave unit to generate an audible signal upon approaching said target point T in said homing mode within a predetermined range, and generating an audible signal using said slave unit. 109. A method for finding a target, comprising the steps of: determining a point Pi by having a user make an input to a monitoring unit; transmitting a ranging signal from said monitoring unit; receiving a reply ranging signal from at least three stationary slave units located on subjects or on objects at a points T1, T2 and T3 within a predetermined range of said monitoring unit, whereby each of said points T1, T2 and T3 form a set of virtual coordinates relative to said point P1; and determining a location of said monitoring unit relative to said slave units using triangulation of points T1, T2 and T3 and said virtual coordinates relative to said point P1. 110. The method for finding a target of claim 109, further comprising the step of: transmitting a ranging signal from said monitoring unit to said slave units; receiving a reply ranging signal from each of said slave units; and prompting said user when said slave is out of a range of said monitoring unit. 111. The method for finding a target of claim 110, further comprising the step of: entering a homing mode on said monitoring unit; prompting said user to select a direction and having said user move in said direction along a path “Delta (1)” in a direction towards a point P2; determining a Delta (n) using a current reference unit pre-programmed in said processor and calculating said Delta (n), which is equal to the difference (P(n−1)−current position); and prompting said user after determining said Delta (n) to move in a direction toward the target T. 112. A method for finding a target, comprising the steps of: transmitting a ranging signal from a searching monitor unit MS; receiving a reply ranging signal from at least three stationary slave units located on subjects or on objects at a points P1, P2 and P3 within a predetermined range of said searching monitor unit MS, whereby each of said points P1, P2 and P3 form a set of virtual coordinates relative to said point Pi; determining said points P1 and P2relative to said searching monitor unit MS having virtual coordinates X and Y using a processor of said searching monitor unit MS; determining a location of a mobile slave unit disposed on a subject forming a tracked target T, said target T having virtual coordinates are Ty and Tx; determining a location of said searching monitor unit MS relative to said tracked target T using said virtual coordinates formed by said stationary slave units and said virtual coordinates are MSxy and Smy for said searching monitor unit MS. 113. The method for finding a target of claim 112, further comprising the step of: determining a location of three stationary master units M1, M2 and M3, whereby said master unit M1 is separated from said master unit M2 by a distance D12, said master unit M1 is separated from said master unit M3 by a distance D13, said master unit M2 is separated from said master unit M3 by a distance D23. 114. The method for finding a target of claim 113, further comprising the step of: determining a distance Ms_R1, Ms_R2 and Ms_R3 [SM_R1, SM_R2 and SM_R3] between said searching monitor unit Ms and said master units M1, M2 and M3, respectively. 115. The method for finding a target of claim 114, further comprising the step of: determining a distance T_R1, T_R2 and T_R3 between said target T and said master units M1, M2 and M3, respectively. 116. The method for finding a target of claim 115, further comprising the step of: determining position ambiguity between said master units M1, M2 and M3 and said distances D12, D13 and D23 so as to minimize ambiguity error between said target T distances T_R1, T_R2 and T_R3 and said master units M1, M2 and M3, respectively. 117. The circuit of claim 116, wherein said data information and ranging signals determined from input signals are coupled through a band pass filter, a distance measurement unit, and said decoder. | This application claims the benefit of U.S. Provisional Patent Application No. 60/449,702 filed Feb. 24, 2003. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to locator systems and techniques, and more particularly, to finding systems for determining the location of objects and/or subjects. 2. Description of the Related Art Most systems for locating a subject or object employ the use of direction locating antennas to determine the position of the subject. However, such locating systems are characterized by shortcomings associated with the size of the antenna at the bandwidth that is optimal for the application. Direction locating antennas experience significant degradation of directional capabilities in close range conditions wherein the separation between a search unit and a target is about several hundred feet or less. It is well known that there is a correlation between antenna size and RF wavelength. A larger antenna is needed for a longer RF wavelength. The need for small antenna size forces the selection of relatively high frequency bands of 900 MHz and higher where there is a lot of interference in the form of reflections and where there is considerable signal degradation as the signal passes over small objects or obstacles. In short, relatively high frequency bands are not suited for searches where the separation between the search unit and the target is greater than a hundred feet. Moreover, the use of directional antennas precludes coordinated searches wherein several search units are homing in on a target or are tracking multiple targets. The use of directional antennas also precludes monitoring a plurality of subjects at the same time because a monitoring unit employing a directional antenna cannot receive and transmit signals in multiple directions. Because of significant directional errors that are associated with directional antennas, the operator also is required to have special skills in performing the search, i.e., locator systems employing directional antennas are not user friendly. Known locator systems rely on distance measurement to determine the separation between a monitoring unit and a subject whose location is being monitored. Distance measurement generally is carried out either by measuring signal strength or by measuring the propagation time between sending a ranging signal and receiving a ranging signal. Examples of systems that use signal strength to determine distance to locate a subject are disclosed in U.S. Pat. No. 5,086,290 and in U.S. Pat. No. 5,650,769, for example. Systems that rely on measurement of signal strength are prone to be unreliable due to noise, interference, signal strength changes, reflections, etc. as well as signal degradation as the signals pass over obstacles. Moreover, measurement error is a function of signal strength, whereby large signal attenuation typically occurs within a building as opposed to outside of a building. In these systems accuracy of measurement is distance dependent, whereby if the distance change is small such systems function appropriately, although, they are known to be less accurate at larger distances. Another system disclosed in U.S. Pat. No. 5,525,967 uses timing to determine distance. Time measurement does not rely on signal strength and is immune to the signal attenuation. Also, the distance measurement error is constant and does not distant depend signal attenuation. Some of the known time measurement locator systems rely on variations of directional antennas, for example a phase array antenna. Such variations allow the reduction of antenna size. However, the price for these improvements is a complex antenna design and an extremely complex signal processing requirements, which result in a lower accuracy, higher cost and power consumption. Also, such antennas are subject to operating frequency limitations and require a wide bandwidth. Known distance measurement systems that employ time-measurement techniques require a large bandwidth in order to achieve a desired accuracy. This results in increased interference, higher circuit complexity and power consumption as well as higher cost. Wide bandwidth requirements also limit the number of devices that can operate simultaneously within a given band. These devices have wide bandwidth requirements that have particular disadvantages such as, for example, such devices cannot operate on business or otherwise unlicensed bands that prohibit ease of the units to transmit and receive in an unregulated environment, limit the units from being sold “over the counter” or integrated with mass-produced popular hand-held radios. In U.S. patent Publication No. 2002/0155845, a position location system is disclosed that uses spread spectrum technology for determining range information in a severe multi-path environment. The system uses ranging processes wherein ranging pulses at eight different frequencies within a band are exchanged between a master radio unit and each of at least four reference radio units. The position and velocity information obtained by the ranging process enables determination of the position of the master radio's position in three dimensions. This system uses a variation of time-measurement based techniques for distance determination. As a result, it carries all of the drawbacks mentioned above plus its operation frequencies and or bands are limited. The system does not employ a directional antenna. Instead, it uses additional four fixed references with known coordinates, or four mobile references that have their coordinates continuously updated via GPS or manually. This system allows simultaneous operation of many units. In this system, the usage of a directional antenna is eliminated. However, the system has disadvantages that include adding a complex infrastructure requiring multiple references, fixed and or mobile, that all include GPS or otherwise need continuous manual updating of coordinate data; limited operating band; increased complexity of the system both technological and logistical; cost; and power consumption. As a result, the system has a very narrow usage in specialized applications. The present invention overcomes such disadvantages of the prior art to provide methods and devices for finding subjects and objects that reduce and or eliminate the infrastructure overhead, for example, the present invention operates without (i) usage of a directional antenna, (ii) any position references, and or (iii) operating band limitations so as to lower the complexity of the system and the overall cost of the devices. SUMMARY OF THE INVENTION A wireless system and method for determining the location of a fixed or mobile subject or object includes a transponder disposed on the target, a transceiver for monitoring the location of the target, a wireless communication system operating on at least one Radio Frequency (RF) band configured to allow communication between the transponder and the transceiver, and a processor configured to find the target by virtual triangulation based on values of position information received from the transponder and the transceiver. The processor is configured to determine virtual triangulation based on successive values of the position information using at least three points P1, P2 and P3 of the transponder respective of the transceiver. The processor can include a successive pattern movement technique configured to find the target by correcting the direction to the location of the target T based on the values of the position information. The processor can also determine the position of the target based on the average speed of the motion of the user of the transponder respective of the transceiver. Furthermore, the processor can determine virtual triangulation based on successive values of the position information from user input on the transceiver. The present invention uses various methods, software, and techniques for finding the target T (“finder” techniques) based on one or more position determination principles including determining the position of the target using virtual triangulation between the master or monitoring unit and at least one target T, whereby the monitoring device Ms measures the distance between it and the slave unit and, alternatively, in addition to measuring the distance between itself and the slave unit, between itself and another monitoring unit, or the monitoring device Ms measures the distance between its own successive locations. The present invention relates to several methods for finding with virtual triangulation relates including: (1) finding with virtual triangulation by generating position information in real-time, in the case of (i) stationary and moving target, and or (ii) in the case of the presence of obstacles; (2) finding with virtual triangulation relating to the average speed of the motion of operator; and or (3) finding with simplified virtual triangulation, whereby the user-device interaction is minimized—eliminating the need for monitoring device Ms to measure the distance between its own successive locations as well as the user's signaling to the monitoring or master unit when in motion or during stops. The present invention is further configured to provide the method for finding by virtual triangulation as well as for finding using a mobile network on a computer-readable medium having stored thereon a plurality of sequences of instructions, which plurality of sequences of instructions including sequences of instructions, when executed by a processor, cause said processor to perform the steps of determining a value of a point P1 from position information received by a transceiver corresponding to a location of a transponder disposed on a target. The user is prompted for a transceiver or a predetermined transceiver to move to a point P2 relative to a location of the target. Another value of a point P2 is determined from position information of the transceiver or predetermined transceiver corresponding to a location of the transponder. Another request is made for a value of a point P3 of the transceiver or of point P2 of the predetermined transceiver corresponding to a location of the transceiver or the predetermined transceiver. The target is found using virtual triangulation principals in accordance with each of said values for said points P1, P2 and P3. DESCRIPTION OF THE DRAWINGS These and other advantages of the present invention are best understood with reference to the drawings, in which: FIG. 1 is a simplified representation of an RF mobile tracking and locating system provided by an embodiment the present invention; FIG. 2 is a block diagram of a master unit of the RF mobile tracking and locating system of FIG. 1; FIG. 2A a simplified representation of the master unit of FIG. 2; FIG. 3 is a block diagram of a slave unit of the RF mobile tracking and locating system of FIG. 1; FIG. 3A a simplified representation of the slave unit of FIG. 3; FIG. 3B illustrates the format for data packets used for communications between the master and slave units; FIG. 3C illustrates the format for identification fields for the data packet format of FIG. 3B; FIG. 3D illustrates the format for the data field for the data packet format of FIG. 3B; FIG. 4 is a block diagram of a master unit and a slave unit of the tracking and locating system of FIG. 1, and illustrating the timing points through the circuits of a master unit and the slave unit during signal transmission; FIG. 4A is a timing diagram illustrating the states sequence of the master and slave units of the tracking and locating system of FIG. 1, including a first-calibration option; FIG. 4B is a timing diagram illustrating the states sequence of the master and slave units of the tracking and locating system of FIG. 1, including a second calibration option; FIG. 5 is a functional block diagram of the master unit of FIG. 2; FIGS. 6A and 6B illustrate an exemplary embodiment of the present invention, whereby FIG. 6A is a functional block diagram of the slave unit of FIG. 3, and FIG. 6B is a simplified representation of the allocation of frequency ranges of the modulation bandwidth to allow multiplexing of voice, ranging signals and data transmission for the RF mobile tracking and locating system of FIG. 1; FIG. 7 is a graph showing position determination in accordance with an embodiment of the present invention; FIG. 8 is a graph showing ambiguity error in the position determination according to FIG. 7; FIG. 9 is a graph showing position ambiguity error as a function of distance measurement error for the position determination method of FIG. 7; FIG. 10 is a graph showing an example of ambiguity error reduction in accordance with an embodiment of the invention; FIG. 11 is a graph showing another example of ambiguity error reduction in accordance with an embodiment of the invention; FIGS. 12A and 12B are process flow charts illustrating a technique (Technique 1) for determining the location of a target; FIG. 13 is a process flow chart illustrating another method (Technique 2) for determining location of a target; FIG. 14 is a process flow chart illustrating still yet another method (Technique 3) for determining location of a target; FIG. 15 illustrates the homing process for determining location of a unit associated with an animate or inanimate object otherwise known as a target in accordance with an embodiment of the invention using Technique 1, where no reference units are needed; FIG. 16 is a diagram illustrating an example of homing using three stationary monitor reference units, providing a fixed reference for the process of FIG. 14; FIG. 17 is a diagram similar to that of FIG. 16 and showing virtual coordinates rotated for mapping into a display grid; FIG. 18 shows a display grid that can be displayed by a display unit of the master unit for showing results for homing using Technique 3 with three stationary reference units according to FIGS. 16 and 17; FIG. 19 is a display grid that can be displayed by a display unit of the master unit for showing the results of homing using Technique 3 with three moving reference units; FIG. 20 is a diagram showing use of Technique 2 for homing with three stationary child units, with virtual coordinates rotated; FIG. 21 is a graph illustrating the use of Technique 2 for homing with three stationary child devices in accordance with an embodiment of the invention; FIG. 22 is a graph similar to that of FIG. 21 and illustrating obstacle avoidance or bypassing operation; FIG. 23 is a diagram illustrating an exemplary embodiment of the method for resolving the position ambiguity between units; where no reference units are needed; FIG. 24 is a diagram illustrating the technique for determining location of a target by resolving the position ambiguity between units, where no reference units are needed; FIG. 25 is a diagram illustrating the technique for resolving the ambiguity zone created between units; FIG. 26 is a diagram illustrating the technique for determining location of a target by resolving the position ambiguity between units; where no reference units are needed; FIG. 27 is a diagram illustrating the technique determining location of a target by resolving the position ambiguity between units; where no reference units are needed; FIG. 28 is a diagram illustrating the technique for determining location of a target by resolving the position ambiguity between units; where no reference units are needed; FIG. 29 is a diagram illustrating the technique for determining location of a target by resolving the position ambiguity between units; where no reference units are needed; FIG. 30 is a diagram illustrating the technique determining location of a target by resolving the position ambiguity between units; where no reference units are needed; FIG. 31 is a diagram illustrating the technique determining location of a target by resolving the position ambiguity between units; where no reference units are needed; FIG. 32 is a diagram illustrating the technique determining location of a target by resolving the position ambiguity between units; where no reference units are needed; FIG. 33 is a diagram illustrating the technique for determining location of a target by resolving the position ambiguity between units; where no reference units are needed; FIG. 34 is a diagram illustrating the technique for determining location of a target by resolving the position ambiguity between units; where no reference units are needed; FIG. 35 is a diagram illustrating the technique for determining location of a target by resolving the position ambiguity between units; where no reference units are needed; FIG. 36 is a diagram illustrating the technique for determining location of a target by resolving the position ambiguity between units, where no reference units are needed; FIGS. 37A and 37B is a diagram illustrating the method of a mobile network to find and or track a target T; FIG. 38A and 38B is a diagram illustrating the mobile network created by the monitoring and slave units to track a target T; and FIG. 39 is a diagram illustrating the mobile network created by the monitoring and slave units to track a target T. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a tracking and locating system 20 is illustrated according to an exemplary embodiment of the present invention for finding, locating, monitoring and or tracking of at least one target (T) that can be animate or inanimate, or both. The tracking and locating system 20 and method is described herein in several exemplary embodiments that have application for finding the location of a target T and or for allowing tracking of numerous targets T in different contexts. The method and system of the present invention is not limited to such enumerated exemplary embodiments in the different contexts as it should be appreciated that techniques and devices of the tracking and locating system 20 can be used for tracking and locating other animate things and or subjects such as pets and other animals. The method, techniques and tracking and locating system 20 can be used in locating inanimate things and subjects such as keys, eyeglasses, wallets, purses, portable telephones or cell phones, remotes for television sets, video cassette recorders and digital video disc players, and generally any item, particularly those carried by a person that may be prone to misplacement. In addition, the tracking and monitoring system 20 can be used for to find, track and monitor mobile targets T such as, for example, tagged animals, personnel, waste management, inventory, time and attendance, postal tracking, airline baggage reconciliation, toll road management, transportation and logistics, manufacturing and processing, inventory or supply chain management, as well as security and surveillance. In other embodiments, the method, techniques and tracking and locating system 20 also can be combined with GPS, Wi-Fi, Bluetooth and other wireless technology for further advantages such as adding capabilities techniques and devices of the tracking and locating system 20 to reduce the workload and steps of a user in the finding, tracking or monitoring function. The tracking and locating system 20 includes at least one master or searching monitor (Ms), such as master units 21, 22, and 23 and at least one slave unit such as slave units 31, 32, 33 and 34, and in an alternative exemplary embodiments, combinations of monitoring, master and slave units as is described herein. The master units 21, 22, and 23 are generally configured to operate as a transceiver. The slave units 31, 32, 33 and 34 are generally configured to operate as a transponder. Each of the master units 21, 22, and 23 and slave can have added functionality as is described herein. Each of the master units 21, 22, and 23 and slave units 31, 32, 33 and 34 are configured to have a unique identification (ID) or tag to identify and distinguish from each other. For purposes of this detailed description, once the unique identification (ID) or tag is disposed on a subject or object, such object or subject can be a Target (T) to be monitored, tracked, located and or found by the techniques employed by the present invention whether the tag is located in a slave unit, or alternatively a master unit. The master units 21, 22, and 23 are configured generally for monitoring, tracking and locating each other and or slave units 31, 32, 33 and 34, as each master or slave unit can be disposed on a user or one or more targets T. The master or slave unit are generally are secured, carried, worn or otherwise affixed to targets T such that they do not separate readily from the target T. Communication between the master units and the slave units is carried using RF signaling techniques on separate bands or on one band utilizing various techniques such as spread spectrum or spread signal to lower the possibility of detection and efficiently utilize the bandwidth of the particular band. In operation, master and slave units can be disposed and located anywhere with the position of any one master or slave unit being located if such unit is within the communicating range of the master unit and or slave unit in the manner described herein to convey position and range related information. A user can hold or wear the master unit 21 and the slave unit 31 can be disposed on an object or subject such as, for example, a person can carry the master unit 21 and the slave unit 31 can be carried or worn by another person such as a child, or other target, whose location is to be monitored and, if necessary, is to be located and found. Additionally, a group of subjects having master units can form a mobile network to track master and slave units disposed on each subject and or objects, which may operate as a waypoint, an obstacle to be avoided, or as an object to be retrieved. The master units can be configured so as to monitor slave units to determine whether the slave units are within a preset or programmed range such as, for example, a value of the range of monitoring of a master unit is set to be ten to thirty meters. Referring to FIG. 1, the circle of radius R represents and illustrates the range 25 of the master unit 21 which is located at the center of the circle, thereby indicating the predetermined range 25, relative to master unit 21. The slave units 31, 33 and 34 are within the predetermined range 25. Sometimes a slave unit 32 will be located outside of the predetermined range 25 relative to master unit 21. However, the slave unit 32 can be located nonetheless within the predetermined range of other master units such as, for example, master unit 23 and master units 21 and 23 can communicate and locate the slave unit 32 using the techniques of the present invention. It should be appreciated that such permissible range 25 is not the receiving range, but rather represents an allowable separation between a values of the location of a slave unit 32 relative to the master unit 21. In the exemplary embodiment, each master unit can communicate with the four slave units 31 through 34 to determine the position of each of the slave units. The master unit transmits a ranging signal to the slave units and receives reply ranging signals from each of the slave units. As above, each master and slave unit is configured to have a unique identification code or address so as to make each master and slave unit addressable individually. Master and slave units can operate on the same frequency or, in other exemplary embodiments described herein, different frequencies are used for transmitting from the master units to the slave units and transmitting from the slave units back to the master units. This configuration allows for full-duplex audio, video and data message transmission and or communication and provide additional advantages such as improved position measurement accuracy and lower device complexity as described herein. Moreover, the tracking and locating system 20 also can provide for voice communication either bi-directional or unidirectional from the master units to the slave units. However, in another exemplary embodiment, the slave units do not have a speaker or microphone. However, in such embodiment, the slave units can be adapted to receive a headset and or microphone, for example, allowing bi-directional voice communication. Each master unit, such as master unit 21, operates to determine periodically the distance between the master unit and each of the slave units 31-34 by sending a ranging signal to the slave units. The slave units 31-34, such as slave unit 31, transmit responsively a reply ranging signal back to the master unit 21. The master unit 21 responds to the reply ranging signal received from the slave unit 31 and measures the time elapsed between the transmission of ranging signals to the reception of the reply ranging signal from a slave unit. In another exemplary embodiment, a processor or signal processing unit of the master unit 21 determines the time of each signal such as, for example, a value of the time that the ranging signal was sent by the master unit 21 to the target unit 31. Once a value of the elapsed time is determined, together with a value for the time of incidence of the ranging signal, the processor determines a value of the distance between the slave unit 31 disposed on the target and the monitoring or master unit 21. The distance is determined by taking the elapsed time, i.e., the total time for a ranging signal originated by the master unit 21 to travel from the master or monitoring unit 21 to the slave or target unit 31 and a reply ranging signal originating from the slave unit 31 to travel back to the master or monitoring unit 21, less a value for error correction determined from several factors such as, for example, an offset amount indicative of internal delays of the slave or target unit 31 and the master or monitoring unit 21. The propagation delay within the master and slave units becomes a problem for short distances such as a few hundred meters or less. The RF signal is transmitted at the speed of light in air, but its transmission is slower in the electronic circuits of the master unit 21 and the slave unit 31 due to propagation delays, which vary by temperature, supply voltage, time and the like. The present invention determines this factor for the value for calibrating units to determine the propagation time through the master and slave units to determine a value of error correction or offset time, which is subtracted from the total time in making distance calculations. The value of the offset time can be determined using a calibration and or loop back procedure as will be described herein. Also, in order to increase the accuracy of a single measurement, the ranging signal may traverse continuously between master and slave units more than once before a measurement is made, as will be described. The ranging signal propagation time can be measured directly or indirectly. In other embodiments, ranging signals are successively transmitted and the tracking and locating system uses detection of phase shift between successive ranging signals. One example of such indirect measurement is measurement of a value of a ranging signal phase shift. The phase shift is proportional to the distance traveled by the ranging signal as well as the value of error correction or offset time for propagation delays in the electronic circuits of the master and slave units. The value of error correction or offset time propagation delays in the master and slave units are determined using a calibration procedure. The calibration procedure of the operating cycle is continuously tested by measuring the delay time (i.e., “calibrating” or periodically testing the master and slave units) to determine the signal propagation time through each unit. Calibration procedure is determined periodically such as, for example, at the time each unit is powered up, at the beginning of each transmission or calibration also can be carried out on a periodic basis during operation to achieve improved performance. Referring again to FIG. 1, according to an exemplary embodiment of the present invention, if slave unit 32 moves out of the allowable range, master unit 21 can enter automatically a search or homing mode. In the search or homing mode, the master unit 21 uses a technique termed “virtual triangulation” or, simple, establishing its own reference points, to determine the location of a slave unit, which can be utilized whether the slave unit is in or is out of the allowable predetermined and or permissible range, for example, slave unit 32 as is shown in FIG. 1. Virtual triangulation advantageously allows the searcher to home in on the slave unit 32 without need of additional references, whether fixed or mobile. The technique of virtual triangulation of the present invention results in higher accuracy and the improved “outcome” of finding the target quickly. The technique of virtual triangulation is involved in various applications to demonstrate the capabilities of the present invention. For example, the slave unit 31 can be stationary, or substantially stationary, or moving at a speed that is comparable with the speed capability of the master unit 21 in which case the location and tracking of the slave unit 31 can be determined using a single master unit 21, which will be termed the searching master or monitoring unit (MS). The user operating the master unit 21 as a monitoring unit MS moves in a pattern and periodically checks to determine the target T position relative to the user. The master unit 21 through an interface gives instructions to the user, in order to correct the path of movement in accordance with the technique of virtual triangulation. Alternatively, according to another embodiment of the present invention, the monitoring unit requests input from other master units queried by the monitoring unit MS thereby locating the slave unit 31. It will be appreciated that, of course, at the same time, the master unit 21 can monitor, determine the location of, and or track other targets T. In addition, one or more of the master units, such as master units 22 and 23, whereby unit 25 is represented as out of range, can function as a fixed or mobile position reference for the master unit 21 and can be queried in determining the location of a slave unit, such as slave unit 31. Such coordinated effort of the master units 22 and 23 allows for efficient and effective determination of the location of the slave unit 31 relative to a master unit 21 when the subject is stationary, out of the predetermined range, fast moving or otherwise is in motion relative to the master unit 21. In other embodiments of the present invention, a plurality of master units, such as master units 22 and 23 (that will come in and out of range 25 depending on the movement of master unit 21), can be used as position reference units in determining the location of a slave unit, such as slave unit 31, with the position reference units being fixed or movable with respect to the master unit 21 that originated the finding of the target T operation. Also, as is described in another method of the present invention, the monitoring unit MS can use stationary slave unit(s) that can be employed as a fixed reference. In another exemplary embodiment of the present invention, the technique of the monitoring unit MS querying other master units is a useful method to find the target T, especially if a target being tracked moves out of the range of a monitoring unit that has principal responsibility or is principally engaged with tracking such target. Such monitoring unit may nonetheless find such target by making a request to other master units, fixed or mobile, as to whether the target is in their communication range so as to find the target. For example, the technique of the monitoring unit MS querying other master units for finding a target in a network of master units, fixed or mobile, can be accomplished by the monitoring unit requesting a list of targets (ID's) in the range of each master unit within the communication range of the monitoring unit. Once a master unit receives the request from the monitoring unit and determines the targets in the range and their unique identification. Once a list of the targets is identified in the area of the particular master unit receiving the request, the master unit responds by sending signals concerning each identified target to the monitoring unit. The monitoring unit can identify the particular target such as, for example, from the ID or from last known position and rate information correlated with the position of the master unit sending the list, thereby locating the target. The method is adaptable such that the monitoring unit can hand off the principal responsibility of monitoring such target to a desired master unit so as to create a dynamic locating and tracking network. Moreover, the monitoring unit MS can utilize other position information, according to an additional embodiment of the virtual triangulation technique, such as the time of arrival of ranging signals transmitted between a master unit 21 and slave units to determine a value of the measured distance to each slave unit 31, 33 and 34 with respect to master unit 21. If any of the slave units move out of the permissible range of the master unit 21 such as, for example, if slave unit 31 should move to the position occupied by slave unit 32, the master unit 21 can be configured to enter a search mode using virtual triangulation to determine from the range measurements provided by the master unit 21, the relative location between the master unit 21 and the slave unit 32 currently out of range. In another embodiment where the slave unit 31 is moving relative to the master unit 21, a plurality of fixed position reference monitoring, master or slave units, such as master units 22 and 23 (if in range 25) or fixed slave units (not shown in FIG. 1), can be used to provide position reference points, allowing the user of master unit 21, or another single unit, to determine the location of the target associated with the slave unit 31. In a further embodiment in which the slave unit 31 is moving fast with respect to the master unit 21 capabilities, a plurality of mobile position reference units are used to define references that can be used by the master unit 21 to determine the location of the target. Preferably, the mobile position reference units are master units 22-23 or other units configured as a transceiver. In this embodiment, the master units or other transceivers provide the reference signals as well as the master unit 21 used to locate target T can be moving with respect to the target T and with respect to other units. This mode of operation allows coordinated searches and or movement where several master units are homing in on a target, or are tracking multiple targets while, at the same time, monitoring other targets such as those associated with slave units 32-34. In another exemplary embodiment of the technique of virtual triangulation, the monitoring unit MS can be configured to utilize additional channels or frequency bands for position information and or communication purposes, for example, the ranging signal includes frequency modulated RF signals transmitted in four channels, one channel for each of the slave units 31-34, and receive reply ranging signals on such channels or on another band. Voice and other communications can be on another band, sub channel or portion of a channel. Alternatively, as is apparent to those skilled in the art, the master and slave units can transmit in the same frequency bands using a time division multiplexing arrangement or spread spectrum techniques. It should be appreciated that although the foregoing general description makes specific reference to master unit 21 and slave unit 31, each of the other master units, such as master units 22 and 23, can function in the manner described for master unit 21, and the slave units 32-34 can function in the manner described for slave unit 31. Moreover, the master and slave units are configured to serve as a position reference unit such as, for example, master units 21 and 23 operate in a search as fixed or mobile position reference units for master unit 22 and, similarly, master units 21 and 22 can serve as fixed or mobile position reference units for master unit 23. While only four slave units are shown and discussed in the exemplary tracking and locating system 20 illustrated in FIG. 1, a command and control system can be configured so as to track and locate multiple master and slave units whereby one monitoring unit is designated as the command unit. In applications where it is necessary to monitor multiple units, the number of transmission channels available in the exemplary embodiment of the present invention can be exhausted. In such an application, the tracking and locating system 20 can be configured to be scalable so as to provide multiple time slots or to provide additional transmission channels to allow for expansion of the tracking and locating system 20 so as to increase the number of master and slave units—to potentially an unlimited number of units. Moreover, interference between two or more master units in same zone is possible, whereby the tracking and locating system 20 can be adapted to account for multiple master units in same zone by assigning different frequency channels to master and slave units, employing time division multiplexing as well as various standards, such as CDMA, or standard and or proprietary communications protocols. In the embodiment of the invention concerning the command and control unit, the location of the master and slave units and all related information can be reported by the query technique to one or more monitoring units MS designated as a control and command unit. The control and command unit can display, process and analyze the mobile network topology dynamically in real-time, including position information of the units in a particular area such as a geographic area. The control and command unit can be configured to alert the user if a particular unit is unaccounted for, outside of the predetermined range, or otherwise is out of certain predetermined location or signaling parameters. The control and command unit can be configured to enter a search or homing mode to allow a monitoring unit MS queried by the control and command unit to search for a particular master or slave in the geographic area. As master units are routing the information about other master units and their targets, the command and control unit can limit the ability of a routing master unit to convey this information to its operator. The control and command unit advantageously can be configured to purposefully limit visibility of certain units in the field to other units in the field by manipulation of data tracked by a database as well as display techniques supported by data values generated in the query technique such as, for example, the monitoring unit MS passes specific information in query technique to some units but to other units. For higher reliability the command and control unit can be made redundant. In such an embodiment, if necessary, additional processing capability can be configured into the control and command unit or by connecting a monitoring unit designated as the command and control unit to a computer through Ethernet, wireless, Bluetooth or other WiFi communication schemes such as, for example, WiFi Protocols 813.11a,b or g. Master or Searching Monitor Unit Referring to FIGS. 2 and 2A, FIG. 2 is a block diagram of an exemplary embodiment of the circuitry of the master unit 21 and, similarly, FIG. 2A is an exemplary embodiment of the physical arrangement of the master unit 21, whereby master units 22-23, as shown in FIG. 1, being configured and operating the same as master unit 21 except for the unique identifying address. The master unit 21 is a transceiver unit that includes a processor 40 for processing data signals, a transmitter section 41 that includes an encoder circuit 42 and a transmitter 43, a receiver section 44 that includes a receiver 45 and a decoder circuit 46, and an antenna 47. In addition, the master unit 21 includes a distance measuring unit 48. The master unit 21 further includes input devices such as, for example, a keypad 49 and a microphone 50, which can be used for voice activation of the processor 40 or for sending a voice transmission to a designated slave unit through the transmitter 43, and output devices such as, for example, a display unit 51 and or a speaker 52. The master unit 21 also includes a Step button 53 and a jack 55 for allowing the operator to use a headset including a microphone and an earphone to hear audible prompts and voice communications. A switch 75 enables the operator to hear synthesized commands generated by the data processor 40 and applied to the speaker 52. The microphone 50 and the speaker 52, which advantageously may be configured as a headset, comprise an interface to allow for audio communications such as voice communication at least with the other master units, and provides the user's with an audio interface for to send and receive audio instructions from the master unit to other master units or to a slave unit. The keypad 49 provides an interface for the entry of data and commands to the master unit. For example, the Step button 53 is used by the user for entering reference point indications that are indicative of how far the user has walked between reference points during a homing operation when a first search method is being used in accordance with the present invention. The display unit 51 shows the status of a homing operation, provides instructions to the user and other information. The display unit 51 also can display a grid that shows the relative location of master unit 21 with respect to other master or slave units of the tracking and locating system 20. The master unit 21 and the slave unit 31 can operate at different frequencies or bands to efficiently track a target T. Preferably, the tracking and locating system 20 of the present invention uses publicly available frequencies such as, for example, the FCC business or unlicensed bands. The wireless tracking and locating system 20 of the present invention can operate on different frequencies to determine using master and slave units 21 and 31, respectively, the location of a target T, for example, one frequency is utilized for transmitting from the master unit to the slave units and another frequency is used for transmitting from the slave units back to the master unit. In still yet another embodiment of the present invention, position ambiguity can be resolved advantageously by master and slave units operating on different frequencies for transmitting from master unit to slave units in a predetermined operating range, for example, the master and slave units operate on a low frequency when the units are large distances apart, and the units are configured to switch to a higher frequency when the units are short distances apart to aid in resolving position ambiguity. Utilizing multiple frequency bands has the advantage of increasing the accuracy and overall efficiency in the locating of the units utilizing multiple RF bands such as, for example, for power consumption, manufacturing cost, tracking and the like as is discussed herein. In such an embodiment of the present invention, the master unit 21 operates in frequency bands of 150 MHz and 460 MHz, whereby a master unit 21 transmits in the 150 MHz band and receives in the 460 MHz band and is configured for simultaneous operations of transmitting and receiving. Similarly, slave units transmit in the 460 MHz band and receive in the 150 MHz band, such as slave unit 31 shown in FIGS. 3 and 3A, whereby such configuration increases the accuracy of distance measurement. In addition, such configuration supports full duplex in audio communications, for example, a push-to-talk button is not needed. In another embodiment, the operating or carrier frequencies for master and slave units are configured in other frequency bands in the RF range, other than the 150 MHz and 460 MHz frequency bands, for example, other GHz frequencies, frequencies in the infrared, microwave or ultrasonic bands. Slave Unit Referring to an exemplary embodiment of the present invention, the circuitry of the slave unit 31 is illustrated in FIGS. 3 and 3A, FIG. 3 in a block diagram format. FIG. 3A illustrates the physical packaging of a slave unit, for example slave units 31-34 of FIG. 1, each having a unique identifying address. The slave unit 31 is configured as a transponder configuration and, as similar to the master unit 21, includes a processor 60 for processing data signals, a transmitter section 61 configured with an encoder 62 and a transmitter 63, a receiver section 64 configured with a receiver 65 and a decoder 66, an antenna 67, and a distance measuring unit 68. The slave unit 31 does not include a microphone, as shown in FIG. 3, however it includes a speaker 71 for receiving voice communications from master units. In another embodiment, the slave unit 31 can also include a microphone 70, shown by the dashed line, to allow bi-directional voice communication with the master unit, as desired for a particular application, for example, the slave unit can include a jack 105 to allow use of a headset for the communication functions. The slave unit 31 further includes a plurality of indicators 69. The slave unit can also include a switch 125 that enables an individual to hear synthesized commands generated by the data processor 40 and applied to the speaker 52. A voice communication request button 170 enables the user to signal a monitoring unit if voice communication is desired. The master and slave units, 21 and 31, respectively, as shown in FIG. 3, are configured with similar transmitter and receiver sections, however, since the master unit 21 provides control and monitoring functions the transceiver includes additional components such as the interface components of the keypad 49 and the display unit 51. Implementation of the Master and Slave Unit Circuitry Referring to FIGS. 2 and 3, the data processing and control functions of the master and slave units can be implemented either in hardware or real-time firmware, or both. In each case, a digital architecture can be utilized advantageously for reduced power consumption, digital communications, and data manipulation to operate synchronously each unit using a common clock as a source of synchronization. Furthermore, the propagation delay of data signals through such synchronous hardware designs tend to stay constant, i.e., a data signal propagation does not change with temperature, supply voltage variations, or the like. As above, a value for the error correction relating to a propagation delay can be determined from simulations, loop back or a direct measurement. A crystal controlled oscillator can generate the clock signal and is selected for accuracy and stability, for example, accuracy to 0.001%. Similarly, the data encoder 42 of the master unit 21, the data encoder 62 of slave unit 31, the data decoder 46 of the master unit 21, and the data decoder 66 of slave unit 31 can be configured to include synchronous hardware and to exhibit constant propagation delay properties. The data encoders 42 and 62 and the data decoders 46 and 66 can be implemented in real-time firmware as a part of the data processing and control block functionality. A value for the error correction relating to the propagation delays of the transmitter sections 41 and 61 and the receiver sections 44 and 64 will change significantly with temperature, supply voltage variations or the like. Error correction values are taken to monitor such the variations in the delay times associated with the processing time of master unit 21 and slave unit 31. The processing time of master units is referred to herein as time T6 and the processing time of slave units is referred to herein as time T3. It should be appreciated that throughout this description certain representations for the capital letter T have been adopted for clarity, whereby (T) represents various time intervals of exemplary embodiments when it is followed by numerals such as, for example, T1, T2, . . . , Tn and (T) represents particular a Target when it is followed by alpha characters such as, for example, TA, TB, . . . , T2*n. Data Transmission Packet Format Referring to FIG. 3B, the data packets configured to communicate between the master and slave units are illustrated. Each data packet includes a Preamble 181, Master and Slave ID fields 182, a Data field 183 and a Postamble 184. The Preamble 181 contains a data pattern that enables, or wakes up, the data decoding mechanism of a master or slave unit receiving the signal, respectively. The Preamble 181 can optionally serve as an automatic gain control (AGC) field to automatically set the signal gain for the receiver of the master or slave unit receiving the signal. Referring to FIG. 3C, the Master and Slave ID fields 182 include separate slave ID fields 185 and master ID fields 186. The slave ID fields 185 include a slave ID synchronization pattern 187, a slave ID address mark (AM) pattern 188, a slave ID data field 189, a slave ID cyclic redundancy check (CRC) 190 and a slave ID pad 191. Similarly, the master ID fields 186 include a master ID synchronization pattern 192, a master ID address (AM) pattern 193, a master ID data field 194, a master ID cyclic redundancy check (CRC) 195, and or a master ID pad 196. The synchronization and address mark (AM) patterns allow synchronization of the decoder with the incoming data. The cyclic redundancy check (CRC) and the error correction check (EEC) allow the detection and correction (in case of ECC) of errors in the data field. The ID pads are bit patterns that move the decoder 46 or 66 to a state where the decoder is ready to receive the next field or message. The ID pads also provide the decoder with a time interval to reach this state. Referring to FIG. 3D, the Data field 183 includes a data synchronization pattern 197, a data automatic mark (AM) pattern 198, a data field 199, a data error correction check (ECC) or cyclic redundancy check (CRC) 200 and a data pad 201. The synchronization and address mark (AM) patterns allow synchronization of the decoder with the incoming data. The cyclic redundancy check (CRC) and the error correction check (ECC) allow the detection of errors and or correction of errors in the data field. The ID pad are bit patterns that return the decoder 46 or 66 to a state and or to provide the decoder with a time interval to reach this state where it is ready to receive the next field or message. Referring again to FIG. 3B, the Postamble 184 places the decoder 46 or 66 into a wait or low power consumption state after received data has been processed. Operating Cycle Referring to FIGS. 1, 2 and 2A, 3 and 3A, 3B-3D, and 4, the following general description of the operation makes specific reference to master unit 21 and slave unit 31. However, as is stated above, the description applies to the other master units 22-23 and to the other slave units 32-34. As is stated above, the master unit 21 measures the time between the RF signals to determine the distance between the two transponders such as one transponder in a master unit and one in a slave unit disposed on a target T. FIG. 4 is a block diagram of the master unit 21 and the slave unit 31 and illustrating the timing points through the circuits of the master and slave units during signal transmission. The mathematical formula for determining the distance D between two transponders is as follows: D=((T2+T4)*V)/2 (1) where T2+T4 is the RF signal round trip time in the air between the master unit 21 and the slave unit 31. Again, throughout this description when (T) represents Time intervals it is followed by numerals and when (T) represents a Target it is followed by alpha characters. T2+T4=(T−T1−T3−T5) (2) where: T is the total elapsed time from presenting the data to be transmitted by the data processing and control block of the master unit, to the reception and processing of the response (from the slave transponder) by the data processor 40 of the same master unit that initiated the transmission; T1 is the transmitter path propagation delay from the time the data to be transmitted have entered the data encoder 42 until the signal transmission commences, e.g. when the modulated RF signal reaches the antenna 47; T2 is the signal elapsed time of travel between the antenna 47 of the master unit 21 and the antenna 67 of the slave unit 31; T3 is the processing time of the slave unit 31 (for example, signal propagation delay in the receiver 65 plus (+) signal propagation delay in the decoder 66 plus (+) data processing time in the data processor 60 plus (+) signal propagation delay in the encoder 62 plus (+) signal propagation delay in the transmitter 63); T4 is the signal elapsed time of travel between the antenna 67 of the slave unit 31 and the antenna 47 of the master unit 21; T5 is the propagation delay over the receive path of the master unit 21 path plus data processing time (signal propagation delay in the receiver 45 plus the signal propagation delay in the decoder 46 plus the data processing time in the data processor 40); and V is the signal velocity in the open air (3*10{circumflex over ( )}8 m/s constant). Because the value of V is very large (3*10{circumflex over ( )}8 m/s) and the value of the distance D is small (D<300 m), the RF signal round trip time in the air between the master unit 21 and the slave unit 31 is significantly less than either of the transmitter path propagation delay, the processing time of the slave unit 31 or the propagation delay over the receive path of the master unit 21 path plus data processing time (T2+T4)<<T1 or T3 or T5. As a result, the values of T1, T3 and T5 are determined with a high accuracy in order to obtain precise distance measurements. Also, T2+T4=(T−T1−T3−T5)=(T−T3−(T1+T5)) (3) or, T2+T4=(T−T3−T6) (4) where T6 is the sum of T1+T5 which is equal to the processing time of the master unit 21 (i.e., the sum of the signal propagation delays in the receiver 45, the decoder 46, the data processor 40, the encoder 42 and the transmitter 43). Equations (1) and (4) yield: D=(T−(T3+T6))*V/2 (5) Therefore, the values of measurements of the times T, T3 and T6, within a short period of time, are used to compensate for the impact of variations in the propagation delays. As propagation delays of the data processing and control functions remain constant, the values of T3 and T6 can be measured during the “loop back” mode of operation. In the loop back mode of operation, the output of the transmitter is connected directly to the input of the receiver, such that the transmitter output signal is forwarded to the input of the receiver via an attenuator. In some embodiments, the data processor 40 (or data processor 60 of a slave unit) places a special test data on the input of the encoder 42 (or 62), starts time measurement (timer) and waits for an Output data ready signal provided by the decoder 46 (or decoder 66 of a slave unit). Upon reception of the output data ready signal, the data processor 40 (or data processor 60 of a slave unit) verifies the validity of data and stops the timer. If the data are valid, the data processors 40 (or 60) calculate the times T6 (or T3) by reading the “loop back elapsed time” from the timer and adding the necessary data validation and data processing times. In other embodiments, encoder and or decoder blocks are not in the path of the ranging signal. Here, the output of the transmitter section is permanently coupled to the input of the receiver section. The data processor 40, and in an alterative embodiment element 60, changes the transmitting frequency to the receiving frequency and enables the distance measuring unit 48 or enables distance measuring unit 68 of a slave unit. In this manner, the circuit generates the ranging signal and performs the distance measuring function. The results are translated, by the control and or processor 40 (or reference numeral 60 in the slave unit 31), back into time delays T3 and T6. Calibration In accordance with an exemplary embodiment of the invention, the master and slave units are periodically “calibrated”. A test signal is transmitted through the master and or the slave units and the propagation time is measured. In some embodiments, the output of the transmitter section is coupled to the input of the receiver section. During calibration, the transmitting frequency such as, for example, 460 MHz, is changed to the receiving frequency of 150 MHz under the control of the data processor 40. The output RF filter of the transmitter attenuates the RF signal being supplied to the receiver section. In other embodiments the transmitting frequency is unchanged, however, the receiver is tuned to the transmitting frequency whereby signal is transmitted through the master and or slave units 21 and 31, respectively, and having front-end RF filter attenuates the RF signal being supplied to the receiver section. Distance and or Time Measurement Sequence Reference is now made to FIGS. 4A and 4B which show timing diagrams illustrating the sequence of the distance and or time measurement events, including calibration. In another embodiment, a one second time cycle time can be utilized to check for the current propagation delay time and to send the ranging signal to the slave unit 31 and receive a reply ranging signal from the slave unit 31. The ranging signal includes an identification field 182 as shown in FIG. 3B. The transmission also employs error checking, bit checking, and other known like means for generally insuring the integrity of the transmitted and received signal. A transmission operation can be aborted after a 5 to 10 second delay or timeout, when a reply signal fails to be received from a slave unit 31 to which an interrogation signal has been addressed. The master unit 21 sends a command sequence configured, in part, to wake up the slave unit 31 maintained normally in a low power idle mode as power saving feature when not conducting ranging signal operations. Advantageously, the circuits of the master and slave units 21 and 31, respectively, may operate in a power saver mode in which energizing power is applied to circuits only when necessary for the master and slave units to operate. Slave unit 31 performs a “propagation time check” (loop back calibration) and transmits a “delay factor” to the master unit 21. The master unit 21 also performs a propagation time check. The master unit 21 receives the reply ranging signal and uses a value of the time of sending the ranging signal, the time of receipt of the reply ranging signal and the values for any error correction constants, in part, calculated by the slave unit 31 and the master unit 21 to calculate the distance between the master unit and the slave unit. Referring to FIG. 4, the master unit 21 can request a calibration procedure from the slave unit each cycle or request a calibration periodically. This request can be made at any time in the operating cycle. Moreover, the master unit 21 can perform its own calibration with each transmission, for example, transmitting the test signal through the master unit and or the slave units on a periodic basis. In another embodiment, the calibration process is carried out initially or “up front” such as, for example, at the start of each distance and or time measurement sequence in the master unit and the slave unit. Certain portion of the propagation delay can be determined at the factory, and such propagation delay will remain substantially constant for the data processing and control functions, such values of the propagation delays can be stored in a table or other memory of the unit for use in determining distance measurements. As is indicated in FIGS. 4A and 4B, both the master unit 21 and the slave unit 31 employ predetermined values for timing out a particular distance and or time measurement sequence. For example, timeout windows can be configured during portions of the distance and or time measurement sequence when the master unit fails to receive a valid distance and or time signal (ranging signal, reply ranging signal or data sequence) within the time defined by a timeout window, the master unit 21 terminates the distance and or time measurement sequence. Thereafter, the master unit 21 can be configured to continue its attempts to obtain a valid distance and or time measurement. If all attempts fail, the master unit 21 enters an error recovery and diagnostics mode and informs the user through the interface by generating appropriate audio and or visual messages. The slave unit 31 can be similarly configured to employ predetermined values for timing out a particular distance and or time measurement sequence. For example, timeout windows can be configured during portions of the distance and or time measurement sequence when the slave unit 31 fails to receive a valid ranging signal (or data sequence) within the a timeout window, the slave unit 31 terminates the distance measurement sequence and returns to an idle state. In a first mode (FIG. 4A), referred to as Option 1, a master unit can enter the loop back mode at the beginning of the distance and or time measurement sequence. In a second mode (FIG. 4B), referred to as Option 2, a master unit can enter the loop back mode in the middle of the distance and or time measurement sequence. Referring to FIG. 4A, in Option 1, the master unit 21 enters the loop back mode and to determine and or otherwise calculate the value for T6. During this time, the slave unit 31 is idle. The master unit 21 issues a command to conduct a distance and or time measurement with calibration such as, for example, a predetermined data sequence; thereafter transmitting the command to the slave unit 31. The data processor 40 of the master unit 21 opens a timeout window and waits for a reply from the slave unit 31. The slave unit checks the slave ID data of the incoming signal. If the slave ID data indicates this transmission is intended for slave unit 31, the slave unit 31 enters the loop back mode and calculates the value of T3. The slave unit 31 exits the loop back mode and transmits to the master unit a reply that includes a “Ready” status and the value calculated for T3. The slave unit 31 opens the timeout window and waits for the ranging signal. The slave unit 31 also prepares to repeat a ranging signal. Upon receiving the “Ready” status signal from the slave unit 31, the master unit 21 responsively receives and stores the T3 value. Then, the master unit 21 starts the “t” count, or in the alternative embodiment using phase detection, enabling the distance measurement unit to generate the ranging signal or phases, and to transmit the ranging signal sequence to the slave unit 31. The master unit 21 opens the timeout window and waits for a reply from the slave unit 31. Slave unit 31 detects and repeats the ranging signal, i.e. transmits the ranging signal back to the master unit 21 that originated this ranging signal. The slave unit 31 will detect and repeat the ranging signal each time it is transmitted by the master unit during a distance and or time measurement sequence. Thereafter, the slave unit enters an idle state. Master unit 21 detects and processes the returned ranging signal and obtains the “t” count or, when phase detection is used, obtains the t value from the time-measurement or distance measurement unit. The master unit 21 calculates distance and checks for possible errors. The slave unit 31 remains idle during this time. The master unit 21 stores the values representing the internal delay for the master unit 21 and the slave unit 31. Master unit 21 compares the calculated distance with a “range factor” to determine if the slave unit 31 is within the preset range. If the slave unit 31 is out of range, the master unit 21 activates the location method to locate the position of the slave unit 31. The location calculation uses distance calculation in the location finding procedure. Referring to FIG. 4B, in Option 2, the master unit 21 operation begins with the distance measurement command and the master unit 21 enters the loop back mode later in the measurement sequence as is described below. The master unit 21 issues a command to conduct a distance and or time measurement (without requesting calibration) and transmits the command to the slave unit 31. The data processor 40 of the master unit 21 opens a timeout window and waits for a reply from the slave unit 31. The slave unit checks the slave ID data of the incoming signal. If the slave ID data indicates this transmission is intended for slave unit 31, the slave unit 31 enters the loop back mode and calculates the value of T3. The slave unit 31 exits the loop back mode and transmits to the master unit a reply that includes a “Ready” status and the value calculated for T3. The slave unit 31 opens the timeout window and waits for the ranging signal. The slave unit 31 also prepares to repeat a ranging signal. Master unit 21 responds to the “Ready” status signal received from the slave unit 31 and enters the loop back mode and calculates the value of T6. Then, the master unit 21 starts the “t” count, or in the alternative embodiment using phase detection, enabling the distance measurement unit to generate the ranging signal or phase, and to transmit the ranging signal sequence to the slave unit. The master unit 21 opens the timeout window and waits for a reply from the slave unit 31. The slave unit 31 detects and repeats the ranging signal, such as, for example, transmits the ranging signal back to the master unit 21 that originated this ranging signal. The slave unit 31 will detect and repeat the ranging signal each time it is transmitted by the master unit 21 during a distance and or time measurement sequence. Thereafter, the slave unit 31 enters an idle state. Master unit 21 detects and processes the returned ranging signal and obtains the “t” count or, when phase detection is used, obtains the t-value from the time-measurement or distance measurement unit. The master unit 21 calculates distance and checks for possible errors. The slave unit 31 remains idle during this time. The master unit 21 stores the values representing the internal delay for the master unit 21 and the slave unit 31. Master unit 21 compares the calculated distance with a “range factor” to determine if the slave unit 31 is within the preset range. The location calculation uses distance calculation in the location finding procedure. If the slave unit 31 is out of range, the master unit 21 activates methods according to the present invention to locate the position of the slave unit 31. Processor for Processing Values of the Data Signals Reference to FIG. 5, according to an exemplary embodiment of the present invention, the processor 40 is configured to determine position information and to process values of data signals. The processor 40 includes a digital signal processor (DSP) 74, a voltage stabilizer 76, and a battery supervisor 78. DSP 74 provides the central control for the master unit 21, thereby establishing the operating sequences for the master unit 21. DSP 74 further controls the components of the transmitter section 41, the receiver section 44 and the distance measuring unit 48 of the master unit 21 during operation of the master unit 21. The DSP 74 includes an analog to digital converter 80 that converts analog signals from the receiver section 44 into digital signals for use by the DSP 74. The voltage stabilizer 76 derives a regulated DC voltage from the battery 77 to supply to the DSP 74. The battery supervisor 78 advantageously provides to the interface an indication of a low battery voltage condition as an output to the DSP 74. The processor 40 further includes a controller 81 configured to interface with the DSP 74 as well as interface, input and output devices such as the keypad 49 and the display unit 51. The display unit 51 can be a liquid crystal display (LCD) having a screen 84 (FIG. 2A) or, alternatively, can be incorporated into “heads up” eyepiece(s) or other headgear of the monitor. The keypad 49 of the master unit 21 can be similar that used in cell phones or otherwise keypad 49 includes a combination of alpha, numeric, control keys or otherwise multi-function keys. Referring also to FIG. 2A, the keypad 49 includes keys for entering “command sequences” for initiating homing operations and for modifying a homing operation. The keypad 49 also includes function buttons (multiplexed with alphabetical characters, similar to those of a cell phone keypad) and or indicators to enable a user to enter control commands and to initiate functions of the master unit 21 during use of the master unit 21, particularly during homing operations. The function buttons can be implemented in software and be displayed include a portion of the display unit can function as a touch screen allowing a user to enter commands by pressing on images displayed on the display screen. The master unit 21 also includes an on/off switch 85 that is interposed between the battery 77 and the voltage stabilizer 76 as shown in FIG. 5. Transmitter Section Referring to FIG. 5, the encoder 42 of the transmitter section 41, includes a digital to analog converter (DAC) 86, a bandpass filter 87 and a frequency converter 88. The DAC 86 produces control signals under the control of the DSP 74 for transmission to the slave unit 31. Encoder functionality can be implemented in firmware for advantages including preprogramming, updating, upgrading and the like. The digital to analog converter (DAC) 86 forms analog information from digital information signals as well as control signals under the control of the DSP 74. The frequency converter 88 operates to convert information and control signals produced by the digital to analog converter 86 at frequencies in the range of 100-3400 Hz into signals at frequencies in the range of 3500-6800 Hz. Switch 89 enables the synthesized speech signals to bypass the frequency converter 88. The information and control signals produced by the encoder are applied to an input of a summing amplifier 96, which passes the control signals to an FM modulator 92 of the transmitter 43. The transmitter 43 includes a frequency synthesizer 90, a timing generator 91, embodied as a crystal oscillator, the FM modulator 92, a power output stage 93 and an output bandpass filter 94. The crystal generator produces a clock signal at 10 MHz as a time base for the frequency synthesizer 90 which, operating under the control of the DSP 74, produces a carrier frequency signal at 150 MHz, for the FM modulator 92. The carrier signal is frequency modulated by the control signals produced by the encoder 42. The output of the FM modulator 92 is connected to the input of the transmitter power stage 93, the output of which is coupled through the output bandpass filter 94 to the antenna 47. The transmitter power stage 93 has an associated A/D converter 95 that is operated under the control of the DSP 74 to control the power level of the output power stage 93. The output bandpass filter 94 has a 150 MHz central frequency. Receiver Section Referring now to the receiver section 44, the receiver 45 includes a bandpass filter 100, a receiver front-end amplifier 101, a frequency synthesizer 102, and an FM demodulator 103. The receiver 45 sensitivity also is controlled by the DSP 74. The input band-pass filter 100 has a passband for passing the 460 MHz signal through the front-end amplifier 101 to the FM demodulator 103. The frequency synthesizer 102 operates under the control of the DSP 74 for providing synthesized signals at 460 MHz less the intermediate frequency value for driving the FM demodulator 103 to recover the low frequency data and voice signals from the frequency modulated 460 MHz carrier signals transmitted by the slave units. Voice communication signals recovered from received input signals are coupled through a band pass filter 104, having a pass band of approximately 100 Hz to 3400 Hz, an analog switch 109 and a low-frequency power amplifier 106 which couple voice frequency signals to the speaker 52 when the master unit 21 is operating in the voice mode. The analog switch 109 is operated to a closed condition under the control of the DSP 74 during voice mode operation. A received voice frequency power measurement circuit 117 derives from voice frequency signals being extended to the speaker, a signal indicative of the amplitude of the voice frequency signal being received. In addition, switch 75 is connected between a terminal of the analog switch 109 at the input of low frequency power amplifier and the output of the bandpass filter 87, which in turn is connected to the output of the digital to analog converter (DAC) 86. The processor 40 can operate the switch 75, allowing the user to hear synthesized commands generated by the DSP 74, which are routed to the speaker 52 when the switch 75 is operated. Information, data and ranging signals recovered from input signals are coupled through a band pass filter 107 to the distance measurement unit 48 and the decoder 46. The band-pass filter 107 has a pass band of approximately 3500 Hz to 6800 Hz. Decoder 46 includes a frequency converter 108, which converts the frequency from 3500 Hz-6800 Hz to 100 Hz-3400 Hz. The output of the frequency converter 108 is applied to the A/D converter 80 for conversion of digital signals supplied to the data processor 40. The decoder functionality can be implemented in firmware for advantages including preprogramming, updating, upgrading and the like. Decoder 46 further includes a conventional Received Signal Strength Indicator (RSSI) 119. The RSSI 119 provides an input to the DSP 74 via the A/D converter 80. The RSSI 119 can be built from discrete components or integrated with demodulator 103. Transmitter 43 configured to provide voice communication between the user and the slave unit 31, as control and ranging signals separated by frequency converters 88 and 108 and filters 98, 104, 107 and 87. In operation, the microphone 50 is coupled to an input of the summing amplifier 96 which output is supplied through a low frequency amplifier 97, with compression and or pre-emphasis, to a low pass filter 98 and an analog switch 99. The analog switch 99 is operated under the control of the DSP 74 to enable the user to send voice communications when the master unit 21 is operating in a voice mode. In addition the antennae can be configured and selected to receive other wireless communications signals such as, for example, wireless communication between the in the command and control unit and a computer processor by Bluetooth and or Wi-Fi protocols, or other wireless signals such as GPS whereby the units can utilize the input signal in the calibration procedure, propagation delay and correct for other errors such as timing and the like. GPS, Bluetooth and Wi-Fi chipsets have been developed and the present invention is easily adapted to collect and route input and output signals from known wireless architectures such as, for example, either (GPS), Bluetooth or Wi-Fi chipsets, to the locating and tracking circuitry of the present invention so as to be operated on by such circuitry and returned to be sent as output signals. As a result, the cost of such chipsets can be economical and the time, distance and position information may be taken from appropriate outputs of the chipset and utilized by the interval processing and position processing systems of the present invention to provide virtual triangulation. In this manner, alternative exemplary embodiments of the present invention can be integrated with GPS, Bluetooth, WiFi and other known communication chipsets operating at various frequency bands to provide advantageously tracking and locating functions in simple and effective manner, anywhere in the world. Distance Measuring Unit In this embodiment, an indirect measurement is used in generating and processing the ranging signal to determine the distance between the master unit and a slave unit. In some embodiments, the indirect measurement is obtained by determining the phase shift between successive ranging signals. To this end, the distance measuring unit 48 includes a phase detector (PD) 110, an analog inverter amplifier 111, a reference signal generator 112, and analog switches 114, 115 and 116. The phase shift-between successive ranging signals can be determined using a voltage controlled oscillator (VCO) 113 and analog switches 114,115 and 116. The ranging signal received from the slave unit is applied to one input of the PD 110 and compared with a reference signal applied to the other input of PD 110 by reference signal generator 112. The difference (error) signal is applied via A/D converter 80 to the DSP 74, which stores the difference, obtained from processing the successive ranging signals. The distance measuring unit 48 is configured to measure the propagation time of the ranging signal as a function of the phase shift of the signal generated by the VCO 113 which, with other above mentioned components, forms a phase locked loop (PPL) to produce a test or calibration signal for use in determining the internal delay time attributable to circuits of the master unit 21. The analog switches 114, 115 and 116 are configured to operate under the control of the DSP 74 so as to alter the configuration of the distance measuring unit 48 during calibration either (i) to initially synchronize the output of the VCO 113 with the reference signal produced by the reference signal generator 112 or (ii) to measure the parameters of the PLL including the PLL gain. When calibration has been achieved, the output of the VCO 113 is connected to an input of the summing amplifier 96 for application to the FM modulator 92. At the same time, the input to the PD 110 is switched to the output of the filter 107. In operation, ranging signals are transmitted between a master unit and a slave unit or, alternatively, ranging signals are transmitted between a monitoring unit and a master unit, a command and control unit and a master unit, or simply signals transmitted and received between units configured as transceivers. The master unit 21 advantageously can be configured to utilize standard commodity hardware components for the antenna 47, the battery, the LCD display, the keypad, the On/Off switches, the LED and the like. Other components of the master unit 21 such as elements shown as functional blocks in FIG. 5 are implemented in hardware and/or processor real-time firmware. The processor 40 can be configured as a digital signal processor (DSP) or other integrated circuit programmable architectures such as, for example, an application specific integrated circuit (ASIC), some other type of processor or a combination of a processor and an ASIC, or a processor and standard parts, or a combination of the above. Slave Unit Referring to FIG. 6A, the slave unit 31 transponder circuit architecture is generally similar to the master unit 31 and can have functionality added to the base transponder features as is described in embodiments of the present invention. When applicable for ease of clarity and understanding the present invention, similar electronic circuitry of the master unit 21 and the slave unit 31 throughout this detailed description will use the same reference numerals but with “50” added to the reference number for components of the slave unit corresponding to similar components of the master unit 21, for example, the input filter 150 of receiver 65 corresponds to the input filter 100 of the receiver 45, as shown in FIG. 5. As above, the slave unit 31 can be configured, for example, to transmit signals in the 460 MHz band and to receive signals in the 150 MHz band for determining position information. Moreover, the slave unit 31 is configured to respond to homing operations but not to initiate such homing operations. The slave unit 31 is configured as a transponder, as described in the methods and system of the present invention, in part, to improve the cost profile of the unit. Some of the differences between the slave unit 31 and the master unit 21 are outlined to further illustrate the features of the present invention. In certain embodiments, the slave unit operates as a simple transponder to receive and reply to ranging signals. The master unit 31 is configured to have complete control over slave units 31, whereby the slave unit 31 does not have an input, voice communication, or display function such as, for example, a speaker, microphone, keypad, a display or the like including a controller or other circuitry to oversee the input functionality. In other exemplary embodiments a slave unit 31 is configured to include an interface for input, voice communications or display such as, for example, a voice communication request button 170 and light emitting diodes 171, 172 and 173. The light emitting diodes 171, 172 and 173 can be configured to indicate the state or other status of the unit. Moreover, the slave unit is not initially configured with a microphone, however, under certain applications it may be desirable and a headset and or microphone can be incorporated by a jack or the like. However, in some applications, it can be desirable for the slave unit 31 to include a display unit and or a keypad similar to those of the master unit 21. In addition, a switch 125 is connected between a terminal of the analog switch 159 at the input of low frequency power amplifier 156 and an output of the bandpass filter 137, which bandpass filter 137 in turn is connected to an output of the digital-to-analog converter (DAC) 136. In operation, the processor 60 can operate and toggle the switch 125 on or off, thereby allowing the user to hear synthesized commands generated by the DSP and routed to the speaker 71 (or a headset). Examples of Operating Modes of the Transceiver Unit According to the exemplary embodiments of the present invention, a command and control unit, a searching monitor unit Ms or master unit 21 can be configured to have four modes of operation, namely: (1) voice communications; (2) data and or command exchange; (3) distance measurement; and or (4) internal delay measurement and or calibration. Referring to FIGS. 2 and 5, the transceiver operating of the system can by configured to utilize modulation bandwidth multiplexing, thereby allowing, for example, simultaneous distance measurement and communication operations as in certain applications it is advantageous to have distance measurement and communication operations performed in parallel rather than separately. Such applications include separate voice communications, data, command exchange, and or distance measurement operations for economical and effective use of the bandwidth occupied by transceiver or combination transceiver/transponder, in a particular band. If a unit is configured to have voice communications, data, command exchange, and or distance measurement operations carried out simultaneously using frequency division multiplexing increased capacity and economy of scale can be realized. Referring to FIG. 6B, as an example, voice communications can be carried out in a first portion 176 of the modulation bandwidth at modulating frequencies from about 0.3 KHz to 3.1 KHz and data and or command exchange or ranging signal transmission can be carried out in a second portion 178 of the modulation bandwidth at modulating frequencies from about 3.8 KHz to 6.5 KHz. The DSP 74 reconfigures the signal paths in the circuits of the master and slave units during the calibration procedure and, as a result, calibration in the embodiments of the present invention is configured to be determined as an off-line condition. (1) Voice Communication Referring now to FIG. 5, the analog switches 99 and 109 are initially configured in a closed position. The output signal produced by the microphone 50 is applied to the modulator 92 through the amplifier 97, the filter 98, the switch 99 (now closed), and the analog summing amplifier 96. The modulator 92 forms an RF signal in the 150 MHz band, which is amplified by the power stage 93 of the transmitter 43. The amplified modulated RF signal is passed through the transmitter output filter 94 to the antenna 47 for transmission to the slave unit 31, or as is described in other exemplary embodiments, transmitted to other master or slave units within the predetermined range. In antenna 47, in addition to the transmitted signal in the 150 MHz band, the master unit 21 can receive a reply ranging or other signal in the 460 MHz band from the slave unit 31 or another master or slave unit. The received signal passes through the filter 100, front-end circuitry 101 to the demodulator 103. After demodulation, the demodulated signal passes through the filter 104 and the switch 102 to the amplifier 106. The amplified signal is sent to the speaker 52. The DSP 74 also can be configured advantageously to synthesize voice signals and send the synthesized voice signals to the modulator 92 via the DAC 86 and the filter 87, bypassing the frequency converter 88 in order to reduce the input to the unit workload of the user or to operate in a hand-free condition. The DSP 74 can send synthesized voice signals to the speaker 52 via the switch 75 and the amplifier 106, or in case of slave unit 31, the DSP 124 sends the synthesized voice signals to the loudspeaker 102 via the switch 125 and the amplifier 156 advantageously utilizing digitized synthesized voice signals to achieve low power and complex signal processing techniques. (2) Data Command Exchange The DSP 74 is configured to generate command and or data signals in a digital format so as to advantageously utilize low power and complex signal processing techniques. When necessary, the digital signals are sent to the DAC 86, which converts the digital signals to analog signals for such operations as, for example, transmitting through RF modulator to RF transmitter and to the antenna or through the speaker. Analog signals are sent through the filter 87, frequency converter 88 and the summing amplifier 96 to modulator 92 to form an RF signal in the 150 MHz band, which is amplified by the transmitter power stage 93 for transmission. In operation, the amplified modulated RF signal is passed through the transmitter output filter 94 to the antenna 47. In addition to transmitting signals in the 150 MHz band, the antenna 47 can be configured to receive data and or command signals, for example, in the 460 MHz band, from a slave unit 31 or from another monitoring or master unit as is described in alternative embodiments herein. The received signal passes through the receiver input filter 100, the front-end circuitry 101 to the demodulator 103, whereby the demodulated signal passes through the filter 107, the frequency converter 108. The signal output from the frequency converter 108 is applied to the input of the ADC 80, which can be integrated with the DSP 74 for processing the received signal. In operation, the configuration using frequency converters 88 and 108 as well as the filters 87, 98, 104 and 107 so as to allow for simultaneous exchange of voice as well as data and or command signal operations as illustrated in FIG. 6B. (3) Distance Measurement At initiation of a distance measurement operation, the DSP 74 sets the analog switches 114 and 116 in the upper position, and the analog switch 115 into the lower position. In this configuration, the PD 110, the amplifier 111 and the VCO 113 form a phase locked loop (PLL) circuit and, as a result, the VCO 113 synchronizes with the reference generator 112. The target slave unit (or another master unit being used as a position reference) closes the analog switch 166 (or switch 116 in another master unit). The VCO 113 is synchronized when the output of the PD 110, reflecting a 90° phase difference between the signals input to the PD 110, whereby the derivative of the PD 110 output over time will equal zero. Upon synchronization, the master unit 21 initiates sending data and or command signals having command instructions to the slave unit 31. In response, a particular slave unit 31 closes the switch 168 so as to route the distance measurement signal from the receiver demodulator output through filter 157 to the input of the transmitter modulator 142 as well as through the summing amplifier 146. In this manner the data and or command signal is looped back immediately and a particular master unit 21 measures the phase shift. Similarly, another master unit 22 may be utilized to close the switch 118 in its distance measuring unit for distance measurement between two master units. After confirmation that the switch 168 is closed in the slave unit being addressed (or switch 118 in another master unit), the DSP 74 operates the analog switches 114 and 116 into the lower position and the analog switch 115 into the upper position, whereby such configuration allows the output signal from the VCO 113 to reach the modulator 92 via the summing amplifier 96. The output signal frequency of the VCO 113 is outside of the pass-band of the filter 98. As a result, combinations of the functions of voice communications, data and or command signals, or distance measurements can be carried out simultaneously, as described above with reference to FIG. 6B. The action of the analog switch 115 will be explained in the following description of the distance measurement method. The amplified, modulated RF signal is supplied to the filter 94 and subsequently to the antenna 47. The antenna 47 advantageously can be configured to transmit and receive on different bands or utilizing one band and/or accommodate spread spectrum signals throughout the bandwidth such as, for example, in addition to transmitted signal in the 150 MHz band, there can be a distance measurement received signal in the 460 MHz band from a slave unit 31 (or another master unit). The distance measurement received signal is supplied to the filter 100 with such output signal being supplied to the front-end circuitry 101 and with such output signal being supplied to the demodulator 103 for demodulating the signal. The signal output of the demodulator 103 is supplied to the input of the filter 107 which supplies its output to the input of the PD 110. The output of the PD 110, the phase error signal, is proportional to the phase difference between the measurement received signal and the reference signal being produced by the reference generator 112. The phase error signal or output signal (error signal) is then applied to the input of the ADC 80 and its output is applied to the DSP 74 as well as to the input of the VCO 113. The output signal of the VCO 113 is transmitted to a slave unit 31 or to another master or monitoring unit and such phase error signal is used to determine accurately distance measurement. In monitoring, master or slaver units, the signal is demodulated and, without any transformation, is applied to the modulator input because the switch 168 in the slave unit 31 (or the switch 118 in another master unit) is closed. As a result, the signal is transmitted back to the particular master unit 21 that originally transmitted the signal. In such originating master unit 21, such received signal is demodulated and applied to the input of the PD 110. During this “round trip”, the output signal of the VCO 113 is delayed. To the PD 110, this delay appears as a phase shift relative to the phase of the output signal of the reference oscillator 112. The output of the PD 110, that is proportional to this shift, is applied to the input of the amplifier 111, and the output signal provided by amplifier 111 is applied to the VCO 113. The VCO 113 starts changing its frequency proportionally to the output of the PD 110. This new frequency signal makes another round trip and is applied again to the input of the PD 110. The amplifier 111 inverts the signal, thereby configuring a 180 degree phase shift from the signal provided by the PD 110, so that the VCO frequency is changing in the direction that adds to the phase difference between the PD 110 inputs, instead of reducing it, as is normal in PLL operation. By allowing the signal to go through successive, multiple round trips, the delay of RF signals is accumulated to allow advantageously for a high precision delay measurement configured for an accuracy that exceeds the actual resolution of the PD 110. Also during this time, the DSP 74 reads-in, at a periodic time intervals, the values of the output signals or other error signals produced by the PD 110 such as, for example, the phase difference error signal, and stores such values in memory. In addition, a technique implemented in the DSP 74 determines the round trip delay value from the output of the VCO 113 to the input of the PD 110 as another error signal useful to determine accurately distance measurement. In the distance measurement mode, the measurement of the round trip delay includes measuring values for delays in internal slave unit 31 and master unit 21 delays such as, for example, master, slave or monitor transmitter or receiver delays; antenna delays; RF signal propagation time between the signal origination monitoring unit and slave unit or another monitoring unit disposed on the target; and the RF signal propagation time between the signal origination monitoring unit and slave unit or another monitoring unit disposed on the target during the second leg of the round trip. Distance Measurement Technique Example Referring now to FIG. 5, in the initial configuration absent the inverting amplifier 111 and absent any round-trip delay, the PLL error signal or original output signal of PD 110, the EPLL response to a phase step function with an amplitude A can be calculated as follows: EPLL=A*exp(−k*t) (6) where “k” is the phase lock loop (PLL) gain, and “t” is the elapsed time from the applying the phase step. From equation (6), after a certain amount of time, the error signal approaches a zero value, EPLL→0, and so the error signal EPLL derivative over time will become very or infinitely small. As the DSP 74 reads-in, at a periodic time intervals, the values of the error signals EPLL produced by the PD 110 and stores these values in memory, it also calculates the EPLL derivative over time. When the value of the error signal EPLL and its derivative fall below a certain threshold(s), the PLL is synchronized. The presence of the round-trip delay D and the inverting amplifier 111 change the PD 110 output error signal (Edmeas) dynamics. With delay D, the error voltage Edmeas cannot be described mathematically in a closed form without certain assumptions: D has to be small (which is the case) and k*D product less than 0.25. With these assumptions the Edmeas values can be calculated as follows: Edmeas=(A/2)*[((B+1)/B)*exp((B−1)/2*D)*t)+((B−1)/B)*exp(−((B+1)/2*D)*t))] (7) where: B=sqrt(1+4*k*D) (8) More precise behavior can be obtained by conducting a simulation as is evident to one skilled in the art. After the DSP 74 operates the analog switches 114 and 116 into the lower position and the analog switch 115 into upper position, the roundtrip delay changes the phase of the VCO output signal, whereby the change can be represented by the step function with an amplitude A=2*pi*D/T (9) where: D/T is the period of VCO oscillations and 2*pi=6.28. After combining equations (7) and (9), the output error signal (Edmeas) of the PD 110 will be as follows: Edmeas=(2*pi*D/T)*[((B+1)/B)*exp((B−1)/2*D)*t)+((B−1)/B)*exp(−(B+1)/2*D)*t))] (10) Because B>1, the signal Edmeas will grow exponentially over time. For a fixed value of k, the signal growth will depend on D value. The Edmeas values over time t for various D values can be tabulated and stored in the DSP 74 memory in the form of a look-up table. The DSP 74 reads-in, at periodic time intervals, the values of signal Edmeas and compares these values with the values stored in the look-up table. The DSP 74 finds the closest match by calculating correlation values between measured and tabulated Edmeas vs. time t values for different D. The D value that yields the highest correlation between the signal Edmeas readings, and or samples, and the tabulated Edmeas vs. values of t is the round-trip delay value. In addition to finding the closest match between the values of signal Edmeas and t, the DSP 74 can also calculate the Edmeas derivative vs. time values and compare (correlate) these with Edmeas derivative table. For accurate results, according to an exemplary embodiment of the present invention, the PD 110, the amplifier 111 and the VCO 113 should be configured to operate in the linear region under the control of the DSP 74, and PD 110 can be configured to set the resolution point at its highest value. The DSP 74 also checks the Edmeas signal samples against a “saturation threshold”. Once the signal Edmeas exceeds a predetermined value established for the threshold level, the DSP 74 reconfigures the circuitry of the distance measurement unit into the PLL in order to re-synchronize the VCO 113 and brings the PD 110 output error signal to its initial value. The value of k can be calibrated or otherwise measured in the PLL configuration that is used for synchronization with the reference 112. Under the control of the DSP 74, the reference 112 can be programmed to produce a phase step function with amplitude a. The DSP 74 can than obtain the EPLL samples and compare or otherwise correlate the obtained samples with the tabulated values of the EPLL vs. t for different values of k. The values for the EPLL and Edmeas tables can be configured advantageously during manufacture thereby loading and storing such the EPLL and Edmeas tables and or other useful tables in the DSP memory. The DSP 74 also calibrates phase detector PD 110 to find the best operating point at which PD 110 has the highest resolution. The values for error correction and other internal signal delay factors of the slave unit 31 and or the master or monitoring unit 21 as well as any transceiver delays such as, for example, the transmitting and receiving of signals of a respective master unit sending the signal, are determined in the internal delay measurement and or calibration mode. Antenna delays can be determined during initial device calibration and a factor, representing the delay attributable to the antenna 47, can be stored in a table in the DSP for use in subsequent calculations. Alternatively, a delay factor can be configured into each unit during calibration when dual antennas are used. (4) Internal Delay Measurement and or Calibration Mode Similarly to distance measurement mode, the DSP 74 is configured in the internal delay measurement and or calibration mode to operate the analog switches 114 and 116 from the lower position illustrated in FIG. 5 to an upper position (not shown) in order to synchronize the output signal of the VCO 113 with the output signal of the reference generator 112. Initially during synchronization, the DSP 74 changes the carrier frequency generated by frequency synthesizer 90 from the 150 MHz band to the 460 MHz band. In addition, the DSP 74 lowers the power of the transmitter output stages 93 by controlling the A/D converter 95. As the pass-band of the filter 94 is configured to operate at around 150 MHz, signals in the 460 MHz band from the transmitter output stages are greatly attenuated already, thereby avoiding saturation of the receiver front-end 101 and advantageously synchronizing without any additional components. In other modes, the frequency of the signals produced by the synthesizer 90 is configured to be set to be within the 460 MHz band. In an alternative embodiment, the frequency synthesizer 90 is configured to have the carrier frequency remain unchanged as well as the power of the transmitter output stages 93. In other embodiments, however, the frequency synthesizer 109 is configured, by the DSP 74, for the FM demodulator 103 to receive signals from the transmitter output stages 93, i.e., around 150 MHz frequency, whereby such 150 MHz frequency signals are greatly attenuated by the receiver front-end filters 100 tuned to the 460 MHz band or frequency, thus avoiding saturation of the receiver front-end 101. After synchronization is complete, as is discussed herein, the DSP is configured to operate the analog switches 114 and 116 to the lower position and the analog switch 115 to upper position. Based on this condition, the output signal from VCO 113 reaches the modulator 92 through the summing amplifier 96. Advantageously the synchronization technique is useful in the distance measurement mode, whereby signals are used to determine the value of an internal round-trip delay time. However, it is important that in this case, the round-trip delay time includes the sum of the values of a delay for each device internal transmitter and receiver delay. Examples of Slave Unit Operating Modes The modes of operation for the slave unit 31 can be configured to be substantially the same as those for the master unit 21 or alternatively reduced to a simple transponder depending on the application and other factors such as cost, efficiency and environmental considerations. One distinction between the mode of operation of the master or monitoring unit and a slave unit is in relation to the distance measurement mode, whereby the switch 168 is configured to route the distance measurement signal from the output of the receiver demodulator 153, through the filter 157, to the input of the transmitter modulator 142 through the summing amplifier 146. Similarly, when a distance is desired to be measured between two monitoring or master units, or otherwise transceivers in the system of the present invention, one of the two master units also uses switch 118 to route the distance measurement signal from the output of the receiver demodulator 103, through the filter 107, to the input of the transmitter modulator 92 through the summing amplifier 96. Position Determination Referring now to FIG. 7, one way of determining the position of a target T without using a directional antenna is illustrated according to the virtual triangulation technique of one of the exemplary embodiments of the methods of finding of the present invention. Virtual triangulation determines the distance to the target T, measured at any three points that do not lie in a straight line, by creating in real time the points for the determination. For example, in FIG. 7, three points P1, P2 and P3 are located along coordinates X and Y such as, for this example at 90 degrees, however, coordinates with angles different than 90° also can be used. Similarly, for determining virtual triangulation in three dimensions, the target T is measured at any four points that do not lie in a straight line, or in one plane, by creating in real time the points for the determination. Simply, the method for finding the position determination of a target T in three dimensional space differ from two dimensional space merely by determining position information values for such fourth point. The value for distance measurement respective of a measured distance between the master unit and the target T can be represented as points P1, P2 and P3. Similarly, values for measured distances between a respective master unit and the target T can be represented as circles configured with radii R1, R2 and R3, respectively, from points P1, P2 and P3. Simply, the target T can be illustrated as located at the point of intersection of three imaginary circles with centers at points P1, P2 and P3 and having radii R1, R2 and R3 corresponding to the distance measurements. Measurements at any two points also will produce a target image TM, as is shown in FIG. 7. The three point measurement technique can be used to resolve position ambiguity. Referring to FIG. 8, where the measured values of such three points P1, P2 and P3 are projected as lying along a straight line, resolution of the position ambiguity requires creating an additional value. For example, the position ambiguity cannot be resolved directly as no variation in location is present to distinguish between the position of points and the target so as to resolve the ambiguity, whereby another value for the position is desired. According, as to yet another embodiment of the present invention, the monitoring, master or slave units can be configured to prompt, upon detecting the position ambiguity condition, such unit to move so as to create a variation or other value to resolve the ambiguity of the straight line condition. For any two circles, such as the circles that have radii R1 and R2, the centers of which lie along the X coordinate, the target coordinate Tx (relative to these three points of measurements) can be calculated as follows: Tx=((R1)2−(R2)2+(X12)2)/(2*X12) (11) where X12 is a value of the difference between the points (P1 and P2) at which the radii R1 and R2 intersect the X coordinate. The value of the target coordinate Ty (relative to these three points of measurements) can be found by substituting the value of X with the value of Tx and the value of Y with Ty in Ry or R2 circles equations (see below) and solving equation for Ty, where: (X)2+(Y)2=(R1)2, (for circle R1) (12) (X−X12)2+(Y)2=(R2)2, (for circle R2). (13) As is illustrated in FIG. 7, each pair of circles has two values of Ty, one for T and the other for its image Tm, thereby creating a total of four points T and three target image points Tm. This can be represented, for example, from equations (12) and (13) which involve circles R1 and R2. Ty1,2=±sqrt((R1)2−(Tx)2). (14) Similarly, values for Ty3,4 and Ty5,6 for the two other T and or Tm pairs of points can be found from the rest of combinations as is shown in FIG. 7. Additionally, some of the Ty(i,j) pairs can have the same value for Ty(k) and, similarly, some of the Tx(i,j) pairs can have the same value for Tx(n). In this condition, identical values for Ty(k) and Tx(n) represent the real target T coordinates, i.e. Ty(k)=Ty and Tx(n)=Tx. In operation, by comparing all six Ty(i,j) values, the values for Tx and Ty can be found by the relationship Ty(k)=Ty and Tx(n)=Tx. In the example illustrated in FIG. 7, it is assumed that there is no error in distance measurement. However, in the operation, there is an error that is associated with every measurement and such error is considered advantageously by the methods and system of the present invention in the determination to achieve improved accuracy. Referring to FIG. 9, a case for resolving error in the determining technique is illustrated according to an exemplary embodiment of the present invention, whereby it can be seen that such error creates an ambiguity error zone shaded in black as illustrated in FIG. 9. Initially, the value or size of the ambiguity error zone appears to be relatively large; however, the size of the ambiguity error zone can be reduced if the relative distance between points P1, P2 and P3 is increased according the technique illustrated in FIG. 10. Referring to FIG. 10, the technique of the present invention to reduce the value or size of the ambiguity error zone increases the distance between points. Initially, when the distance between points P1 and P3 is increased from 1.75*E to 4*E (point P4), the ambiguity error zone can be reduced substantially, whereby the value of the width of the ambiguity error zone is equal to E and the value of the length of the ambiguity error zone is less than 2*E. According to the technique to reduce the ambiguity error zone by increasing the distance between points: (i) E is the worst case error value, (ii) E is constant such as, for example, E does not depends upon distance; and (iii) a typical value for E is about two to three meters. Referring to FIG. 11, the technique to reduce the value or size of the ambiguity error zone further is illustrated. Similarly, when the distance between points P1 and P2 is increased from 1.9*E to 5*E (point P5), the ambiguity error zone is further reduced, where the value of the width of the ambiguity error zone equals E and the value of the length of the ambiguity zone is less than 2*E. Where the distance between points is infinite, such as points P1 and P2, the ambiguity error zone will be reduced to a square having each side equal to E. However, in operation, an infinite distance between points is a remote possibility. Accordingly, for the system transceiver or monitoring unit, the processor is configured to recognize position ambiguity, ambiguity error zone, and to reduce such position and ambiguity zone errors utilizing the above-described techniques. Other techniques and steps in the various methods of the present invention are advantageously implemented to reduce complexities, increase accuracy, and automate the finding, coordinated search and movement and tracking process of a target. The methods and system of present invention is configured to reduce the overall task load on the user operating the monitoring or master unit 21, for example, during a homing operation by requiring the user to perform limited, simple repetitive tasks such as directing the user to move along straight lines, to make 90° or 180° turns. Such limited, simple repetitive tasks are conveyed to the user through the interface of the monitoring or master unit 21 either audibly or through a display of detailed execution instructions. In operation, when utilizing the ambiguity reduction techniques of the present invention, the monitoring and or other master units are configured to bring the operator into a close proximity of a target T, within a value of a circle of [sqrt(2)*E] radius. At all times, the user can monitor other animate and inanimate things associated to a particular master or slave unit such as, for example, other children or persons, to track other targets and or inanimate objects, which is a disadvantage of the monitoring capabilities in the prior art when, for example various types of directional antenna are employed for homing. For example, in known devices when a directional antennas are employed for homing, not only will the operator not be able to monitor other targets T while homing in on one target T, but the operator also is required to have special skills in performing the search because of significant directional errors that are associated with these antennas. Moreover, prior art devices have not appeared to automate the searching process. As a result, the improved operation of the present invention as set forth in the exemplary embodiments offers advantages over the prior art by automating homing and reducing the tasks on the person monitoring the subjects. In addition, unlike the prior art that employs an omni-directional antenna(s), the various techniques utilized by present invention reduce workload on the user, the operation complexity, increases the flexibility and capabilities of the user, for example, the techniques where the user is capable of finding, locating and or tracking the target without fixed and or mobile references. Examples of Methods for Finding Virtual Triangulation Finding Techniques The following search techniques for finding the target T (“finder” techniques) are based on one or more of the position determination principles described above, for example, the method according to the consine theorem. An exemplary technique according to the present invention is to determine the position of the target using virtual triangulation between the master or monitoring unit and at least one target T, whereby the monitoring device Ms measures the distance between it and the slave unit and, alternatively, in addition to measuring the distance between itself and the slave unit (or another monitoring unit), the monitoring device Ms measures the distance between its own successive locations. There are several technique for finding with virtual triangulation relates that are described herein, which are generally: (1) finding with virtual triangulation by generating position information in real-time, in the case of (i) stationary and moving target, and or (ii) in the case of the presence of obstacles; (2) finding with virtual triangulation relating to the average speed of the motion of operator; and or (3) finding with simplified virtual triangulation, whereby the user-device interaction is minimized—eliminating the need for monitoring device Ms to measure the distance between its own successive locations as well as the user's signaling to the monitoring or master unit when in motion or during stops. The monitor and slave units may support one or more of these techniques. In some embodiments, preferably all of the search routines are stored in memory of the digital signal processor (DSP) of the master control units, such as (DSP) 74 of master unit 21. The routines can be selected by the user by making appropriate entries using the keypad 49 and the display unit 51 of the master unit 21. Alternatively, the master and slave units can be configured advantageously for operation in applications that require and use only a subset of the virtual triangulation techniques described herein. A. Transceiver and Transponder Virtual Triangulation Point Search Technique An exemplary method may be used in a situation when a target T moves out of an area and continues to move around. Reference is made to FIGS. 12A and 12B, which illustrate a process flow chart for the Point Search Technique and FIG. 15, which illustrates an exemplary application. Referring first to FIG. 15, in the example, it is assumed that a slave unit is disposed on an animate subject such as, for example, a child, person, animal or an object in motion (keys in a purse) for that matter, to form a target. The target T is represented to be located at a point T in FIG. 15 which is out of the predetermined range of a master or monitoring unit located at a point P1. In response to a monitoring operation, the user is prompted that the slave unit is out of range, and the monitoring unit automatically enters the homing mode. The user selects a direction and for example, begins moving along a path “Delta (1)” which happens to be in a direction towards a point P2. As the user walks along this path, the user depresses the Step button 53 (FIG. 2A) on the master unit once for each step taken. After the user has walked a distance, such as to point P2, that the value Delta (1) (the distance that the user has walked) is sufficiently large as to minimize the ambiguity error zone, the user is prompted to stop. The processor of the monitoring unit determines if the value Delta (1) is sufficiently large by determining that the distance between subsequent points Delta (n) is equal or greater than (4−5)*E, for example. A desirable Delta (n), which is equal to the difference (P(n-1)—current position), can be also pre-programmed into the processor of the monitoring unit 21. The monitoring unit is storing the current “step count” which is indicative of the distance that the user has walked along path “Delta (1)”. The monitoring unit prompts the user to go right or left from point P2. In the example, it is assumed that the user chooses to turn left, which in the example is in a direction away from the location of the target T. The user begins walking along a path “Delta (2)” towards a further point P3, operating the Step button 53 (FIG. 2A) to register the number of steps taken by the user along path “Delta (2)”. After the user has walked a sufficient distance along the path “Delta (2)”, the user is prompted to stop and wait for a prompt as to in what direction to head. Assuming that the user has reached a point P3, the user is prompted to “Go Back” or to “Go Left”, which directs the user towards the target T. In the example, the user selects to go left and upon reaching a point P4, the user is prompted to “Go Left” and so the user will now be moving in the direction of the target at point T. When the user reaches a point P5, the user is prompted to stop and is then prompted to “Go in the Same Direction”. When the user reaches a further point P6, the user is again prompted to stop and is then prompted to “Go Right”, which direction is toward the target point T. As the user approaches the target point T, the monitoring unit will determine that the target point T, and thus the subject being located, is again within range. Moreover, the user typically will come within sight or hearing distance of the subject. The monitoring unit will revert to the homing standby mode. However, if for any reason the user wants to continue the homing operation, the user can override the monitoring unit. Other features, options and functions of Search Technique 1 are set forth in the following description of Search Technique 1. It will be appreciated that the prompts to the user from the monitor can be adapted to be simple and easy to use such as, for example, audible or text prompts could follow the metaphor and gradations between “hot” and “cold”, and present a human aspect to a homing function—“getting hotter” or show direction by the use of arrows displayed on the master unit's LCD. Referring to FIG. 12A, after initialization and programming, the monitoring unit may enter a homing standby mode, exemplary flow that A, block 240, wherein the monitoring unit periodically measures the distance to the subject. The monitoring unit may continuously display “Homing Standby On”. The user can disable the standby mode by entering an appropriate sequence. When the standby mode is disabled, the monitoring unit may continuously display “Homing Standby Off”. Block 241 determines if the measured distance between the monitoring unit and the subject is within a pre-programmed value such as, for example, within the predetermined range of the master unit, and if so, the user is prompted to this effect, block 242, and the flow loops back, through block 243, to block 241 and the monitoring unit stays in the homing standby mode and continues periodic distance measurements. The homing mode can be also entered unconditionally by the user request or independent action. The monitoring unit is set into the homing mode by depressing a button or entering a sequence using the keypad. Block 243 enables the user to override the automatic mode and to request entry into the homing mode even when the subject or target is within range. This also applies to a case when an operator wants to continue homing search even if the target is within the range. The user enters an appropriate sequence and the monitoring unit 21 continuously displays “Range OFF”. If block 241 determines that the target is not within range, the monitoring unit prompts the user and automatically enters the homing mode, block 244, if programmed to do so. After entering the homing mode, the message “Homing On” is displayed on the message display 51 (FIG. 2A). A reset button or reset code entered using the keypad, can be used to reset (unconditionally exit) the homing mode, if desired by the user. In that case, the message “Homing Off” will be displayed on the message display. With regard to the monitoring range value, it should be noted that the monitoring unit can not conduct the search within the ambiguity error zone—within a circle of (sgrt(2))*E. As a result, the monitoring range distance value should not be smaller than the (sgrt(2))*E. Exemplary flow path B includes a homing mode starting at block 244, the R1 distance (FIG. 7) between the starting point P1 and the target T is measured and the message “Homing ON” is displayed on the display along with the R1 value. This is the first point P1 of distance measurement. In block 245, the R1 measurement is qualified in exemplary flow path X (FIG. 12B), as will be described. Exemplary flow path X qualifies the following events: (1) has the user moved within the range of the target; (2) has the user reached the ambiguity error zone; and (3) is there an unexpected significant change in the target's position or a change using statistical approach. Depending upon this qualification outcome, the exemplary flow path X may or may not continue the flow. In case the flow is continued, the monitoring unit enters exemplary flow path C3 at decision block 246. In exemplary flow path C, the user of the monitoring unit may enter the “Find next point” mode. The monitoring unit keeps track of number of passes through path C at block 246. If decision block 246 determines that it is the first time through the path C, flow proceeds to block 247 and the monitoring unit prompts the user with an appropriate message, including “Choose Initial Direction” prompt. The initial direction of walking is not important, the user can select any direction, block 248. The monitoring unit prompts the user to start walking and the user starts moving in the selected direction, block 249. Alternatively, from block 248, the user can exit the homing mode, block 250, and the flow returns to the standby mode, path A, at block 240. Otherwise, from block 246, flow proceeds to block 251 and the monitoring unit updates the target position and block 252 prompts the user with movement directions to make one or more of the following choices: (1) the user can continue without changing the direction—“same direction”; (2) the user can make a 90° turn to the right—“right”; (3) the user can make a 90° turn to the left—“left”; or (4) the user can make a 180° turn, for example, “go back”. The latter choice usually is displayed for points Pn where n>3. The position of the target is determined in path C (block 251) when distance measurement values for three points Pn become available (n=3). Subsequently, when more then three distance measurement values are available (n>3), normally the most current three measurements are used to update the target position (provided that these last three measurements do not lie along a straight line, FIG. 8). Decision block 253 determines whether there is an unobstructed path. Because of physical obstacles, there can be cases where it can be difficult or impractical to choose a direction. In such cases, block 254, the user may: (1) exit the homing and homing standby mode; (2) move to a new, more open location; and (3) re-start the search, e.g. path A at block 240. Otherwise, the user selects the “same direction” or “right” or “left” or “go back” and positions his or her self accordingly, block 255 and starts following the selected path. The user walks in a straight line, marking every step by pressing and releasing the “Step” button (FIG. 2A) on the monitoring unit. The monitoring unit 21 automatically counts the number of steps. Alternatively, an external pedometer device automatically counts the steps taken by an operator in searching for a target, thus eliminating the need for the user to continuously depress the “Step” button while walking, or completely eliminating the need for a Step button 53 (FIG. 2A). In response to a request by the controller of the monitoring unit, the pedometer electronically transfers the step count to the monitoring unit. The pedometer's step count can be reset automatically upon the monitor unit request. At all times that exemplary flow path C is executed, it is important that the user continue walking close to a straight line. Step length can be programmed into the monitoring unit 21. The monitoring unit 21 can hold step lengths of several operators. In addition, it is important that the user continue moving in the direction chosen. The monitoring unit 21 can prompt the user with an appropriate message in this regard. Flow proceeds from block 256, exemplary flow path D, to block 257, which measures the distance the user has walked thus far. In this regard, the monitoring unit 21 periodically measures the distance between the monitoring unit and the target unit. Each measurement is qualified in path X, block 270 (FIG. 12B), which qualifies the measurement. Path X may or may not continue the flow. In the cases when path X continues the flow, in path 4, the processor of the monitoring unit checks for the next point criteria match—block 257A. If both or one of the following two events occurs: (1) the difference between the current measurement and the previous distance measurement point R(n-1) value is statistically greater than a certain value, which depends upon E and R(n-1), and is calculated by the processor of the monitoring unit; (2) the distance between the previous position P(n-1) and the current position is greater than a certain distance, which amongst other things also depends upon E and R(n-1), and is calculated by the processor of the monitoring unit. A desirable difference (P(n-1)−current position) can be also pre-programmed into the processor of the monitoring unit 21. While executing path D at block 257A, the user may encounter some obstacles, as represented by block 261. If the user encounters an obstacle, the user has the following options to deal with these obstacles: (1) To bypass small obstacles, as represented by block 262, the user executes a detour routine—block 263 and continues moving in the original direction. While bypassing the obstacle, the user can stop incrementing the step count until the user is back on track (direction) after which the user can estimate the straight line distance and adjust the count such as by pressing the Step button 53 (FIG. 2A) without making steps, or enter the estimated step count via keypad, which also includes the case of external pedometer; (2) if it is difficult or impractical for the user to continue in the same direction, the user can cancel the measurement point search (restart this point search—block 264), recall the previous point state, block 265, and check for an alternative available direction, block 266. If an alternative direction is available, the user can return back to the previous measurement point and choose an alternate direction, block 267, and continue the next measurement point search, returning to block 256 (path D); or, if an alternative direction is not available, from block 266, exit the homing mode, choose and move to a new location, block 268, re-start the search (by re-entering path A, at block 240). After the “next point criteria match” event has occurred, block 257A, the monitoring unit flow enters exemplary flow path E, block 258. In path E at block 258, the monitoring unit prompts the user to stop walking. The user stops walking and acknowledges this event of stopping by pressing a button or, for example, holding the “Step” button depressed for a long period of time. This is the next point of distance measurement Pn. Flow proceeds to exemplary flow path F, block 259. At this time, block 259 causes the monitoring unit to display the Rn value, and the processor of the monitoring unit saves the Rn value and the distance between P(n-1) and Pn, which is equal to: |P(n-1)−Pn|=(step_count*step_length)=Delta(n) (15) Thereafter, flow returns to block 246 and repeats path C to find the next Pn point and the value Rn associated with that point Pn. Referring to FIG. 12B, a description of path X is now provided. In block 270, the processor of the monitoring unit evaluates the following possibilities or cases. Decision block 271 determines if the distance between the monitoring unit and the target T is within a pre-programmed value or communication range, the monitoring unit prompts the user, block 272, and if so, exits the homing mode, block 273, unless the user wants to continue the homing operation, block 274. This can be done even if the subject is within the range. The user enters an appropriate sequence and the monitoring unit responsively displays “RANGE OFF”. In the “RANGE OFF” mode, block 275, if the processor of the monitoring unit has determined that the user is within the target's ambiguity error zone, the monitoring unit displays “Ambiguity Zone Standby”, block 276, and the processor checks for the user request to exit the “Ambiguity Zone Standby” mode, block 277A. If there is no such request the flow returns to the Step 2 (FIG. 12, block 244). If the master unit 21 has moved into the ambiguity error zone, in this mode the user can move freely and can use other means and or sensory means, visual, voice, etc., for detecting the subject. The monitoring unit processor erases the prior distance measurement point's values, but continues the distance measurements to the target (path B). When the user has moved outside of the ambiguity error zone, the monitoring unit will enter path C, where operator will be prompted with the “First time message” and the search will be automatically re-started. If, while in the ambiguity mode, the user wants to exit the “Ambiguity Zone Standby” mode, the user must enter such request. The processor will check for this request in block 277A. The user is prompted and the “Ambiguity Zone Standby” mode is exited, block 278A and the flow is returned to path A. Note that upon exiting the “Ambiguity Zone Standby” mode, the processor automatically clears any pending homing mode request (unconditionally exits the homing mode). If the distance is outside of the range or outside of the ambiguity error zone, the processor of the monitoring unit checks to see if the user decided to re-start the homing process, block 277. In this case the user is prompted, the homing mode is exited, block 278, and the flow is returned to path A. If there is no request to re-start the homing process, the processor evaluates the target's position change, block 279. If the position change is qualified, the processor continues the homing operation, block 279A, the monitoring unit continues the flow (return), enters the next step. If after calculations have been carried out, the processor of the monitoring unit can not qualify the distance measurement data, the monitoring unit prompts the user, the homing mode is exited, block 278B, and flow is returned to path A. This can occur when the target's position has abruptly shifted and the previously obtained distance measurement data cannot be relied upon. B. Virtual Triangulation˜Successive Pattern Movement Technique Referring to FIGS. 23-36, another exemplary embodiment of the methods of the present invention relating to virtual triangulation technique is described for determining the actual location of the target. Referring to FIG. 23, when a slave unit 31 is located within range of the monitoring unit 21, the monitoring unit 21 can measure the distance to a slave unit 31, but cannot determine the direction to the slave unit 31. Thus, conceptually, the slave unit 31 can be anywhere within the two concentric circles. The monitoring unit 21 utilizes “Successive Pattern Movement Technique” to find the precise location or position of a target or other unit. The Successive Pattern Movement Technique utilizes the Cosine Theorem to obtain and correct the direction to the location of the target T or slave unit after each additional measurement. The Successive Pattern Movement Technique for finding, tracking and or locating operates in real-time both in the case of stationary and moving target as well as in the case of the presence of obstacles. For example, if an obstacle is present, the user can move around the obstacle while determining the location of the target. In operation, the user is instructed to move in relatively straight lines under the Successive Pattern Movement Technique. For any unplanned change in direction of movement, the user simply requests a distance measurement and calculation for the next successive movement such as, for example, the user inputs through the interface a request to the monitoring unit 21 to perform a distance measurement and the unit calculates a value for the distance for any of the slave unites 31, 32, 33 and 34, as is shown in FIG. 1. At the point of such request, the monitoring unit 21 stores the distance the user moved between direction changes either from a pedometer connected thereto or by the user entering a step count as is described herein. Referring to FIG. 24, a method to perform distance measurement R0 at the initial point−d0 is illustrated with respect to the monitoring unit 21. As above, the monitoring unit 21 can have a measurement error represented by E. At the location of a point for a particular monitoring, the error of the monitoring unit and or slave unit (represented as the Target T) is between R0−E and R0+E in the range represented by or on the circle with radius R0 as is shown in FIG. 23. It should be appreciated that the measurement error E is determined reliably by a difference in the two measurement readings Ri and Ri+1 when the following criteria is matched: |Ri−Ri+1|>2*E (16) The condition d1>2*E exists when the user initially moves in any direction for a predetermined distance d1, as is illustrated in FIG. 24. In measuring the traveled distance, the user can use a pedometer associated with the monitoring unit 21 such as, for example, to measure the distance traveled (di). Otherwise the monitoring unit 21 counts steps as input by the user to provide a signal to device, for example, pressing a button for every step. Also, the user can count and input a total number of steps into the monitoring unit 21 and or input a value in the monitoring unit 21 that the distance di has been covered after walking the distance di. Once the user covers distance di the monitoring unit 21 prompts the user to stop, whereby the unit generates a distance measurement by processing the position information. The monitoring unit 21 instructs the user audibly or through the display to proceed in another direction according to distance di+1. The monitoring unit 21 generates a Ri+1 distance measurement, and as in the first instance of computing the value is R1, The processor 40 of the monitoring unit 21 determines sectors where the target may be located from the associations and relationships generated by the following equations: α 1 = arccos ( ( R i + 1 + E ) 2 + d i 2 - ( R i - E ) 2 2 * d i * ( R i + 1 + E ) ) ( 17 ) α 2 = arccos ( ( R i + 1 - E ) 2 + d i 2 - ( R i + E ) 2 2 * d i * ( R i + 1 - E ) ) ( 18 ) Here, it is possible that because of the distance measurement error (E), the absolute value of the arccos function argument may exceed 1 and, in such case, the processor can be directed to assume that angle α is equal to 0 or 180 degrees depending upon the sign of the arccos function argument. Referring to FIG. 25, this condition is illustrated where the target may be located from the associations and relationships generated from solutions of the above equations, where: α2=0° Since cosine is a symmetrical function, a value for a mirror image sector exists where the target may be located logically. Here, the arccos function determines and generates two symmetrical possible target location sectors and, where one of angles alpha is 0 or 180 degrees, two such sectors will have a common point. Here, the monitoring unit 21 prompts and or otherwise directs the user, audibly or visually, in a motion toward one of the two possible locations such as, for example, advantageously along the corresponding bisector lines for quick resolution of the association and relationship of the location of the target as is shown in FIG. 25. At this time, the monitoring unit 21 determines the next di+1 value, which in the first instance is d2. Alternatively, the monitoring unit 21 can be use fixed value, i.e.: d1=d2=d3= . . . (19) whereby, the values of di can be calculated by: d i + 1 = R i * cos ( α 0 ) - R i 2 * cos 2 ( α 0 ) - R i 2 + ( R i - 2 * E ) 2 ( 20 ) Where α0 is the difference between the largest of (α1 or α2) and γ. α0=(max<α1α1>)−γ (21) Ultimately, under such conditions the sequence of events may be identical for motion along each of the bisectors, whereby the user can select one of the bisectors and walk along the selected bisector for distance d2 such as, for example, a bisector that leads away from the target T. Furthermore, the correction of angle in erroneously chosen path occurs normally relative to the direction of motion as is shown in FIGS. 26 and 27. The monitoring unit 21 determines at the end of d2 a new direction or bisector(s) for the next di value, under this example (d3), if programmed to do so as is shown in FIG. 26. The monitoring unit 21 again will prompt and communicate the new bisector direction to the user and optionally its value (d3). The target T is located in bisector when the target T location is in the intersection region of sectors from the previous and current determination, as is shown by the sector arc lines in FIG. 26. Each time the monitoring unit determines, or alternatively the user selects, the bisector of the newly formed sector to arrive on the target location such as, for example, the new bisector for distance d3. At the end of d3 the monitoring unit determines the new direction and or bisector and the next di value (d4), as is shown in FIG. 27. Again, the target T location can be determined to be located in the intersection region of sectors from the previous determinations and the current sector lines as is shown in FIG. 27. The technique is repeated as is shown in FIGS. 28 and 29 until the target is reached. As is shown in FIG. 30, the monitoring unit can propose an alternative angle and or direction of motion leading away from the target T, which when selected by the user, alternate bearings for each bisector, for example, after a subsequent determination on a predetermined bisector an opposite bearing is selected by the user, e.g. first left then right. Alternating bearings advantageously simplifies the position locating-tracking technique by determining the bearing to the position quickly without needing to calculate the intersection of sectors, which improves performance when tracking a moving target T and reduces the workload of the processor section of the monitoring unit as well as reducing the number of measurements taken and the time of search. In addition, according to the technique described above, the monitoring unit 21 can be configured to propose or otherwise automatically select for the user the bisector and or direction of movement to achieve optimal performance. C. Virtual Triangulation˜Successive Pattern Movement Technique Using the Speed of a User's Movement Under certain circumstances, the Successive Pattern Movement Technique using virtual triangulation is optimized when a user or the monitoring unit has no pedometer for inputting steps, or the user does not want to count steps such as, for example, after the initial movement and or position determination such task of inputting can become repetitive. The monitoring unit 21 nonetheless can perform the finding, tracking and locating operations by using the average speed of the motion of the user. The value of the average speed of the motion is determined by calculating a value for the time a user was in motion for a particular or selected direction. For example, an average speed of Vavg can be calculated from the user's initial movement (d1) during the determination using a step count. Subsequently, this virtual triangulation determination follows the sequence of: a) Initially, the user moves in any direction for a predetermined distance d1 b) The monitoring unit 21 determines a value for Vavg, the average speed of the user according to formula Vavg=(d1)/(t1) (22) where t1 is the time the user spent traveling distance d1. c) The monitoring unit 21, of course, likewise repeatedly determines another direction of the subsequent motion and the next value of di. The substitution of value of t(i)*Vavg into Equation 22 can be made instead of distance di in order to generate consistent data when traveling along bisectors, whereby: a) A user moves along the selected bisector. The monitoring unit 21 counts the time of the motion of the user along the selected bisector and prompts the user to stop when the value meets the condition: t(i)*Vavg≧di (23) b) The monitoring unit 21 carries out the measurement of distance to the target T and performs the calculation of the new sector and associated bisector as well as di+1, if desired. c) The monitoring unit 21 continues determining such measurements by repeating steps a) and b) until the value of and or the location of the target T is reached. By this method, the user is not inputting counted, or is not otherwise counting steps; instead the monitoring unit 21 determines a value of the time of the motion. For accuracy, the monitoring unit is configured to determine when the user has stopped (i) by the user inputting a stop, (ii) by a predetermined timing-out condition, or (iii) where the monitoring unit signals the user to turn off the timer after a predetermined time. Furthermore, the monitoring unit 21 can be configured to remain in a suspended state until motion is detected—thereby starting timing—as there is no need to perform continuous or periodic measurements of distance to the target T. The monitoring unit 21 can be configured to be based on a value of the measurement error (E) so as to determine a value when the user moves for a certain minimum distance ensuring that a reliable change in the distance measurement occurs. D. Virtual Triangulation˜Successive Pattern Movement Technique Minimal User-Unit Interaction Under certain circumstances, according to yet another exemplary embodiment of the present invention, the Successive Pattern Movement Technique using virtual triangulation is optimized to reduce the workload on the user, or to reduce the interaction between a user and the monitoring unit, whereby further simplification of the technique eliminates the step count effort and the user's input or otherwise signaling to the monitoring unit for motion or during stops. Normally, a user input signals, continuously or on periodic basis, indicate to the monitoring unit position or distance between successive movements. However, under a simplified, minimal user-unit interaction technique, the user inputting or otherwise providing such input information can be reduced in scope for determining position information while monitoring stationary or quasi-stationary targets. It is appreciated that while the minimal user-unit interaction technique is less efficient in comparison with other techniques such as, in particular for moving targets, nonetheless the minimal user-unit interaction technique is advantageous for determining and monitoring stationary or quasi-stationary targets that innately do not generate numerous values of position information. As a result, minimal user-unit interaction technique can be expressed as follows: 1. The user initial movement is: a) Start moving in any direction for a predetermined distance d1>2*E, as is illustrated in FIG. 24. The unit or user counts steps and, after determining a covered distance d1, the unit prompts the user to stop; b) The unit determines a distance measurement and sectors where the target T can be located, as is illustrated in FIG. 25 and Equations (17) and (18); c) The unit prompts the user to change direction, e.g., to make a left or right turn and the user input or signals to the unit and starts moving in chosen direction for a predetermined distance d2=d1 as is shown in FIG. 31; d) At the end of the leg having a value of d2, the user stops and the unit determines a distance measurement, finds sectors where the target T can be located based on such distance measurement and d2 as is shown in FIG. 31 (purple lines); In addition, the monitoring unit determines a sector for the logical location of the target T such as, for example, the sector is determined from the intersection region (blue lines) of sectors from the previous and current calculations—orange and purple sector arc lines—as well as its bisector represented by a magenta line, as is illustrated in FIG. 31. The bisector angle gamma is calculated from the values of d1 and d2 and the values of the angles generated and referenced as alpha, as is illustrated in FIG. 31. 2. The monitoring or master unit 21 prompts the operator or user to walk along this bisector and no distance d3 will be specified at this time. The user walks in the direction of bisector (see FIG. 32). At the same time the monitoring or master unit starts periodically measure the distance to target T a) Device keeps record of periodical distance measurements. After every measurement the monitoring or master unit performs the following calculations: If RMIN≦RCUR, than RMIN is unchanged; or Otherwise, the RMIN value is changed to the RCUR value At the beginning RMIN=RCUR=R2. However, the monitoring or master unit still keeps the R2 value and keeps it as for further calculations RMIN cannot be larger than RCUR, otherwise RMIN=RCUR. b) Thereafter, the monitoring or master unit compares the current distance measurement (RCUR) against the following criteria: |R2−RCUR|>2*E (24) and RCUR−RMIN>2*E (25) Where: R2—is the measurement value that was obtained after completion of movement along d2 and before the user began walking along the bisector; RMIN—is the minimum distance measurement value from all previous periodic measurements c) If criterion of Equation (24) is true and R2−RMIN≦2*E and R2<RCUR, then the monitoring or master unit prompts the operator or user to stop, whereby the user is moving away from target. This should not normally happen at this stage, as the target image ambiguity has been resolved by calculating the intersection region of sectors from the d1 and d2 operator movements. It is an indication of target movement. In this case the user may switch to the main technique 1 or stop and wait for target movement to stop and then start from paths a and b. d) If criterion of Equation (24) is true and criterion of Equation (25) is false and R2>RCUR then: the user is closing in and the monitoring or master unit prompts operator to continue his movement. Alternatively, the monitoring or master unit may not provide any feedback to operator as long as he is getting closer to the target, for example, as is shown in FIG. 32. e) If criterion (25) is true, and R2−RMIN>2*E, then: the monitoring or master unit prompts operator to stop and to change the direction. The monitoring or master unit calculates the angle Ω for the new two directions options. These new directions are represented by the bisectors of the two newly formed sectors, which the target may belong to (blue lines in FIG. 33). These sectors can be found from the following equations: β 1 = 90 ° + arccos ( ( R MIN - E ) ( R CUR + E ) ) ( 26 ) β 2 = 90 ° + arccos ( ( R MIN + E ) ( R CUR - E ) ) ( 27 ) It is notable, similarly to the previous technique, that when the module of the arccos function argument in Equation 27 exceeds 1 it can be assumed that angle beta is equal to 90 or 270 degrees depending upon the sign of the arccos function argument. The user can choose from two bisectors. Operator picks up a bisector and walks along it. f) During this time the monitoring or master unit keeps record of periodical distance measurements as well as calculating the RMIN. It also compares the current distance measurement (RCUR) against the following criteria: |Ri−RCUR|>2*E (28) and in Equation (25). Where Ri—is the RCUR measurement value that was used to calculate the angle omega, i.e. obtained before the user has changed the direction of movement. Note: At the beginning RMIN=RCUR=Ri. However, the monitoring or master unit will keep the Ri value (see also step 2). Similarly to step 2, sub step b). g) If criterion of Equation (28) is true and Ri−RMIN≦2*E and Ri<RCUR, then: The monitoring or master unit prompts operator to stop because either operator has chosen a bisector that leads away from the target T or the target is moving. While stopped, the user can check if target is moving. If target is moving, may switch to the main technique 1 or wait for target movement to stop and then start from paths A and B. Otherwise, operator has chosen a bisector that leads away from the target. The monitoring or master unit will ask operator to walk along the chosen bisector in an opposite direction (see FIG. 34) and will restart from step 2 above. However, the monitoring or master unit will keep record about the turn around event. h) If criterion of Equation (28) is true and If criterion of Equation (25) is false and Ri>RCUR then: the user is closing in and the monitoring or master unit prompts operator to continue his movement. Alternatively, the monitoring or master unit may not provide any feedback to operator as long as he is getting closer to t: he target i) If criterion of Equation (25) is true, and Ri−RMIN>2*E, then The monitoring or master unit prompts operator to stop. The user has chosen bisector that leads toward the target T, but passed the point of shortest distance to the target T and it is time to change the direction as described below 1. The monitoring or master unit calculates a new direction, using formula Equations (26) and (27) in the same manner as in step 2, sub step e), (see FIG. 35). However, if there was a turn around event, then the ambiguity of selecting from two available bisectors is eliminated, as the target is assumed to be in the vicinity of the previous bisector that was not chosen by the user; i.e. the bisector of choice and the previous (old) bisector that was not followed (chosen) must be intersecting (see FIG. 34) 2. Otherwise, the user must choose between two available bisectors. Here the user may follow several strategies. For example, the user may alternate bisector direction in a manner that is described in technique 1; or always choose bisectors in only one direction, for example, bisector to the left; or randomly (with the help of device) choose the bisector. Note: the monitoring or master unit can be preprogrammed to automatically provide bisector selection in all of the above strategies 3. The process continues by repeating the step 2 subsections f) through i) until the user reaches the target, see FIG. 36. Here, red and purple arrows indicate the user movements. In this example the bisector to the left is always selected. For both techniques 1 and 1′ it should be noted, that once the user arrived into ambiguity error zone where: 0≦RCUR≦2*E (29) the monitoring or master unit will not be able to deliver a better accuracy and operator has to rely on other means of locating the target, for example, by enabling audio signals to the user such as a buzzer in the target device. II. Technique 2, Method for Finding A. At Least One Slave Unit Used as a Reference Point A process flow diagram illustrating a search that uses three slave units as position references, which speeds up the target position determination and homing process as is shown in FIG. 12A. Alternatively, stationary reference points may be determined from monitoring or master units within range, however, the distinction in this method stationary slave units are less expensive, smaller in size and consume less power. Also a single stationary transponder reference points can be utilized as “bread crumbs” so monitoring unit(s) will be able to determine their own location relative to a single stationary unit using a virtual triangulation technique or any other technique described in the later sections. In the case of the three stationary slaves at any given point, the monitoring unit 21 can determine its location in the virtual coordinates that are formed by these three stationary slave units. As a result, the user does not need to mark steps by pressing the “Step” button or use the pedometer, or employ timer. Although the user is prompted to change the direction, the direction change does not need to be close to 90°, 180°, etc. This makes it easier for the user to bypass obstacles, because the user does not need to cancel the previous (next step) measurements and does not need to return to the previous point or perform distance estimation. In the end, the homing-in process is simplified and allows for the user's faster movement. Also, the homing-in process becomes obstacle resilient. An example of a distance determination process using Technique 2 with three stationary slave units is illustrated in FIGS. 20-22. Referring first to FIG. 20, the relative positions of a target T. which here is a slave unit or other transponder disposed on a child target (C), and a monitoring unit or searching monitor Ms are shown with respect to virtual coordinates X and Y. The positions of the target T, the searching monitor Ms and the three reference slave units C1, C2 and C3 have been rotated for mapping into a display grid. Every position and virtual X, Y coordinate is rotated. However, the relative positions between all of the monitoring units Ms, C1, C2 and C3 and the target T are unchanged. The searching monitor Ms at point P1 is separated from target reference units C1, C2 and C3 by distances P1—C1, P1—C2 and P1—C3, respectively. Target reference unit C1 is separated from target reference unit C2 by a distance D1,2. Target reference unit C1 is separated from target reference unit C3 by a distance D1,3. Target reference unit C2 is separated from target reference unit C3 by a distance D2,3. The distances between the target reference units C1, C2 and C3 can be measured (by the searching monitor unit Ms) or have fixed values that are entered into a “searching monitor unit Ms” during the initialization phase. Also shown are Ck—Y and C_X—target reference units C1-C3 X,Y coordinates. The distances, along the X coordinate between the target reference units C1 and C2 is C2—X and the distance between reference units C1 and C3 is C3—X. The distance along the Y coordinate between C1 and C2 and C3 is C1—Y. The Pny, Pnx (where n=1,2,3, . . . n+1) are the X,Y coordinates of the Ms points Pn (for simplicity only first point Pn coordinates are shown). These can be calculated from the distances Pn_Ck and the X,Y coordinates for the positions of the target reference units C1-C3. To avoid position determination ambiguity, the three stationary target units C1, C2 and C3 which are used as reference units preferably should not be located along a straight line as discussed above with reference to FIGS. 7-10, for example. Moreover, the distances D1,2, D1,3 and D2,3 should be large enough to minimize ambiguity error as discussed above with reference to FIGS. 9-11, for example. In some embodiments, the preferable separation distances can be stored in the memory of the master unit and displayed automatically by the searching monitor when entering into Technique 2 mode. FIG. 21 shows the relative locations between the searching monitor Ms, the target reference monitors C1, C2 and C3 after the searching monitor Ms has moved a distance Delta 1, from its initial position at point P1 to a point P2 and then a distance Delta 2 from point P2 to a position P3. When the searcher with searching monitor Ms reaches point P2, the monitoring unit calculates the position of the searching monitor relative to the virtual coordinates X, Y using distance information provided by the target reference units C1, C2 and C3. As a result, the X,Y coordinates for points Pn (Pny and Pnx) become known. The distance Delta is calculated automatically from the values for Pny and Pnx. The searching monitor provides a prompt “Go right or left”. In the example, the searcher has chosen to go right and proceeded to point P3 and the process is repeated. The searching monitor Ms provides a prompt “Go back or go right”. In the example, the searcher has chosen return and proceeds to point P4 where the searcher is prompted to proceed. This takes the searcher into the proximity of the target T such that the target is within range and the searching monitor returns to the homing standby mode. FIG. 22 illustrates a variation of the example shown in FIG. 21 wherein the searcher with the searching monitor Ms encounters an obstacle upon selecting to go right from point P2. Upon encountering the obstacle, the searcher cancels the original point P2 and continues moving to a new point P2′ (also referred to as “New P2” in FIG. 22). In response to the prompt, the searcher again has chosen to go right, and the searcher has bypassed the obstacle without need to move close to a straight line. The example continues as described above with the searcher continuing to points P3 and P4 and then to the proximity of the target. Referring to FIG. 13, the process flow chart for this method is similar to that for a virtual triangulation point search, as shown in FIGS. 12A and 12B, and accordingly for clarity, similar or like blocks of the process flow diagram for this method are referenced using the same reference numbers as corresponding blocks, for example, Paths A-C, of blocks 240-255 and Path D is entered via block 280. Block 257 provides distance measurement and checking for path X conditions as in virtual triangulation point search technique, thereafter flow proceeds to block 257A which provides “next point criteria match” similar to finding by virtual triangulation. After the “next point criteria match” event has occurred, block 257A, the monitoring unit flow enters path E, block 258 and continues to path F, at block 259, and returns to path C similar to finding by virtual triangulation. Alternatively, if block 257A determines that a next point criteria match event has not occurred, flow proceeds to decision block 281 which checks for an obstacle. Block 282 determines if an obstacle can be bypassed—if so, flow proceeds to block 283 which cancels the previous point measurements and, at block 284, allows direction to be changed and the flow is returned to block 257—if not, block 282 determines that the obstacle cannot be bypassed, flow proceeds to block 285 which exits the homing mode and the user must chose a new location and restart the homing process. Flow is ultimately is returned to path A, block 240. B. Multiple Monitoring or Master Units as Reference Points Referring now to FIG. 38A and 38B another technique for finding the target is illustrated which uses three stationary monitoring or master units as reference points in an adaptive interactive mode. According to the method, a monotoring unit is configured to operate as a searching monitoring unit Ms and to generate values for points P1, P2 and P3 by obtaining such points P1, P2 and P3 from at least three stationary master references Mref. The designation of a monitoring or master unit in the operable range as the searching monitoring unit is advantageously adaptive for optimal performance such as, for example, when a particular monitoring unit can hand-off its searching monitoring unit Ms functions under predetermined conditions including the target moving out of its range into the range of another monitoring unit. Furthermore, the method allows for tracking of multiple searching monitoring or master units Ms and targets T by using stationary references and advantageously increases the location or otherwise speeds up the search process. The method also shares generated data, generates data between multiple searching monitoring or master units Ms concerning the position of multiple targets T, thereby making an interactive network of monitoring or master units Ms. The monitoring or master units Ms can communicate with each audibly, visually, transmit data concerning identity, distance measurement, multiple error factors—attenuation, propagation, calibration, clock synchronization or the like as well as data lists of targets within the predetermined range of a predetermined monitoring or master units Ms. The monitoring or master units, irrespective of being designated as the searching monitoring unit Ms, can be configured to measure repeatedly the distance between each monitoring or master unit within the predetermined communication range. In operation, an interactive search is configured advantageously to have the monitoring or master units Ms to not rely on the distance measurements between successive moves of the units Ms, which eliminates the repetitive method of inputting reference points such as, for example, the steps of a user counting steps, entering one or successive inputs, stopping and waiting for a new direction, and so on as has been described herein at least with respect to the virtual triangulation determination. Each monitoring or master units Ms can display the position of target T and each monitoring or master units Ms in range on a grid or polar LCD display having scaled coordinates. Under certain circumstance it is desirable and advantageous to display the traces of movement between successive values of the position of the target T and each monitoring or master units Ms or optionally, to display the stationary references in relationship to the target T and each monitoring or master units Ms. It should be appreciated that the interactive search forms a virtual system of coordinates utilizing values of reference points from a combination of any three stationary monitoring or master units Ms. Referring now to FIGS. 37A and 37B, an embodiment of the present invention describes the interactive search utilizes a virtual coordinates system and the search algorithm description. Three stationary monitoring or master units Mref are shown as (A) Mref-A, (B) Mref-B, and (C) Mref-C, or simply reference points A, B and C, whereby one of A, B or C is designated as the origin. For example, assuming (A) Mref-A is the origin, (B) Mref-B is used to define abscissa X and, more importantly, the third (C) Mref-C does not belong to abscissa Y because the A, B and C coordinates in this virtual system define values, which are as follows—A:(0, 0), B:(AB, 0) and C:((AC*cos(BAC), AC*sin(BAC)), where BAC is the angle between vectors AC and AB. The distances between each of Mref (A, B and C) are known, and from these A, B, and C coordinates can be calculated. Furthermore, the distances between each of Mref (A, B and C), Ms and the target T will be known. As a result, the monitoring unit 21 can be configured in this manner to the coordinates of target T and searching monitoring unit Ms in this virtual coordinate system. The searching monitoring unit Ms also can display each of Mref (A, B and C), Ms and the target T on the virtual coordinate grid. However, at the beginning of the search, while in the original position, Ms cannot determine an original bearing of the target T no reference has been determined with respect to the virtual coordinates. In order to determine the original bearing, searching monitoring unit Ms has to move initially in any direction until the stationary masters, each of Mref (A, B and C), detect a change in the distance between searching monitoring unit Ms and the target T. After that the searching monitoring unit Ms has moved to new coordinates respective of target T, the searching monitoring unit Ms can display the new coordinates on the virtual grid. In addition, the searching monitoring unit Ms can be configured to display traces of the movement of the searching monitoring unit Ms and the movement of target T, the bearing from the searching monitoring unit Ms to the target T, including the bearing angle, and other information. The steps of this method can be repeated while the searching monitoring unit Ms and or the target T are moving with the searching monitoring unit Ms displaying interactively the relative positions of the searching monitoring unit Ms and the target T relative positions, the bearing of the searching monitoring unit Ms to the target T, and other related information. Finally, other mobile searching monitoring Ms units and targets T may be optionally displayed as well as the stationary masters, each of Mref (A, B and C) according to another embodiment of the display mode for the monitoring unit 21. It is appreciated in this illustration of the exemplary embodiment, that: 1. The monitoring unit is configured to assume the value of the point B coordinate X is positive, and that the value of the point C coordinate Y is also positive, so as to avoid position ambiguity. 2. Three stationary references do not belong to a straight line. 3. The value of the coordinates of each of the target T and the searching monitoring or master unit Ms can be based on the principles of the method of the present invention involving intersecting circles having radii R1, R2, and R3 or on polar coordinate principles. 4. The user of the searching monitoring or master unit Ms does not count steps or time, whereby the user utilizes the unit's display to obtain the relative position to the target or targets, to obtain a bearing on target or targets as well as other information. 5. The value of the coordinates, bearing angles and other information of each of the target T and the searching monitoring or master unit Ms, can be calculated by any of Mref units and/or the Ms unit, or in a distributed fashion. 6. The value of the bearing of the searching monitoring or master unit Ms to the target T can be determined based on the triangle formed by the values of the points of two sequential positions (or points of movement) of the any of the values of the points of reference master units Mref and/or the searching monitoring unit Ms and the current target T from the available coordinate values for the target T and searching monitoring unit Ms. 7. The accuracy of position determination depends, in part, on accuracy of the value of the measured distances of the reference points generated by at least one of the Mref units and/or the Ms unit, for example, Mref (points A, B and C) disclosed above. C. Multiple Slave Units As Reference Points It is appreciated in this illustration of the exemplary embodiment, that the present invention may use any three stationary slave references (Sref) are able to serve multiple stationary monitoring or master units because technique utilizes the base transponder aspect of the slave unit. As described above in case of using the values generated by three stationary monitoring or master units as reference points, any three stationary slave references Sref likewise form such a virtual system of coordinates, if each of the Sref units must not be positioned on a straight line. As a result, any monitoring or master units that are within the communication range of these three stationary slave references Sref of this example, each unit can determine its own coordinates relative in this virtual system of coordinates. Slave units are not configured to communicate with each other but communicate as a transponder to a ranging signal from a monitoring or master unit. Therefore, the distance between the three stationary slave references Sref is measured by a monitoring or master unit (or otherwise) and pre-programmed or transmitted and stored in each Sref unit. Similarly, the target T coordinates can be determined by monitoring or master units as the target T is essentially a slave unit disposed on a subject or object. Despite the step of having to pre-load or program distances to the stationary slave references Sref to establish a reference triangle of virtual coordinates such configuration has been shown to be useful under limited circumstances. A user can manually establish a reference virtual coordinate system, a triangle of virtual coordinates, or path of virtual coordinate's extremely obtuse triangle referenced loosely as a “bread crumb” marker for field work, whereby one or more stationary slave units are made a point of reference to mark—an individual bread crumb—a particular path taken. A monitoring or master unit Ms and or user may locate such marker's position relative to a marker using virtual triangulation techniques. Three or more monitoring or master unit Ms operating in a mobile network such as, for example, references points of Mref also can be used to locate a monitoring or master unit's Ms position without need of virtual triangulation. It is appreciated in this example, that the multiple advantages and expanded opportunities for finding by using three stationary slave references Sref include the lower cost of these units due to less electronic functionality as compared to monitoring or master units, as well as the smaller size and lower power consumption obtainable in a slave unit. Further advantages of such a configuration include (i) allowing a monitoring or master unit to determine the traveled distance between successive movements, (ii) relative direction of these movements, and (iii) freeing operations of the monitoring or master unit as well as the user from measuring (directly or indirectly) these distances using the measured distance methods described above and or using electronic compass. Alternatively, if the coordinate calculation functionality is desired to be implemented and or performed by either a monitoring unit, master unit, or even by one or more Sref unit in the virtual coordinate system, such coordinate calculation functionality by firmware or the like. It should be appreciated that: 1) Unlike the example illustrating using three stationary master references, if a single searching monitoring or master unit Ms under certain conditions cannot locate a signal or obtain a bearing angle to a target and, accordingly, such searching monitoring or master unit Ms can be configured to revert to the virtual triangulation techniques to locate, track and or otherwise find the target. in a mobile network as is described herein, such searching monitoring or master unit Ms reverting to the virtual triangulation techniques can be freed from other functionality by the command unit such as, for example, such searching monitoring or master unit Ms from measuring distances between successive movements; 2) Alternatively, three stationary slave references Sref can be effectively use moving monitoring or master units as reference points in a mobile network, whereby such master reference units and the user operating them are now freed from measuring (directly or indirectly) distances between successive movements and freed from using an electronic compass; and 3) Finally, the three stationary slave references Sref can be successfully employed for building hierarchical points of reference for the methods and system of the present invention when establishing mobile networks for finding targets, whereby such systems establish a reference virtual coordinate system, or triangle of virtual coordinates or path of virtual coordinates extremely obtuse triangle referenced loosely as a “bread crumb” marker for field work, whereby one or more stationary slave units are made a reference to act as marker—an individual bread crumb—of a particular path taken. A monitoring or master unit Ms and or user may locate such marker's position relative to a marker using virtual triangulation techniques. Three or more monitoring or master unit Ms operating in a mobile network such as, for example, references points of Mref also can be used to locate a monitoring or master unit's Ms position without need of virtual triangulation as is described in the next example. D. Interactive, Adaptive Network Using Units as Reference Points Referring again to FIGS. 38A and 38B, an interactive, adaptive network of units using units as points of reference is described in view of the system of the present invention and its various embodiments. A searching monitoring or master unit Ms can be configured to be based on an adaptive interactive mode or technique for finding the target using three stationary monitoring or master units as reference points, or a preestablished bread crumb virtual coordinate system as points of reference. According to the method, a searching monitoring unit Ms generates values for points P1, P2 and P3 by obtaining such points P1, P2 and P3 from at least three stationary master references Mref, or virtual coordinates of three stationary slave references Sref, where (i) a searching monitoring unit Ms is equipped with an electronic compass, (ii) a Cartesian coordinate system is established—a North—South and East—West coordinate system—with one of the stationary monitoring or master units Mref at the origin of the Cartesian coordinate system, (iii) coordinates of any two other stationary monitoring or master units Mref are identified in such established Cartesian coordinate system or, alternatively, such searching monitoring unit Ms is capable of measuring and storing the direction of movement relative to one axis of such established Cartesian coordinate system such as, for example, North. Accordingly, such searching monitoring unit Ms can determine a value for a bearing angle relative to the target T from a value relative to one axis of such established Cartesian coordinate system—for example the North axis—when searching monitoring unit Ms is in its original position and, thus, there would be no need for an initial searching monitoring unit Ms movement described above. The determination of the value of the bearing angle, under this example the bearing angle is designated (Alpha) as is shown in FIGS. 38A and 38B, relative to the North axis, is as follows: Determine the coordinates of target T and searching monitor Ms; Generate a value based on the relationship Alpha=arccos((x2−X2)/R); Determine movement in the direction relative to the North axis, accordingly: If Alpha>90 and x1<X1 then the bearing value is <<(180-Alpha) degrees South—West>>; 1. If Alpha>90 and x1>X1 then the bearing value is <<(180-Alpha) degrees South—East>>; 2. If Alpha>90 and x1<X1 then the bearing value is <<Alpha degrees North—West >>; or 3. If Alpha<90 and x1>X1 then the bearing value is <<Alpha degrees North—East>>. Where R is the distance between searching monitoring unit Ms and the target T; x1 is the first (1st) value of the coordinate respective of target T; x2 is the second (2nd) value of the coordinate respective of target T; X1 is the first (1st) value of the coordinate of searching monitoring unit Ms; and X2 is the second (2nd) value of the coordinate of searching monitoring unit Ms. Additionally, the determination of the value of the bearing angle is guided by the principle that the larger the first coordinate, the more to the East is the object and the larger the second coordinate, the more to the North is the object, and so forth. Each of the units include the transponder function so as to identify a position. Such transponder function is important and is used by the system and methods of the present invention for identifying positions relative to the stationary units and to calculate values of bearing from other units. In a broad sense, monitoring or master units are configured with an interface display or otherwise “see” other reference points, such as other master or slave units, as well as to communicate between other monitoring or master units. III. Technique 3, Mobile Network Method for Finding Referring now to FIGS. 38A and 38B, in this example, each of the three mobile master references Mref are configured to serve, separately or concurrently, as a searching monitoring unit Ms for finding a target T in an adaptive, dynamic mobile network. Using multiple mobile master units as points of reference, and the values generated individually by each of the master units, allows for increased speed in determining and finding the target T according to a particular search in progress as well as making such search process interactive utilizing the additional functionality of master units such as, for example, the transceiver functions to transmit and receive data and or values for position information, for full duplex communications, and position ambiguity reduction. Principally, the mobile master units are configured to communicate with each other and are capable of measuring and determining the distance between each other as each is capable of determining the position of a target T and respective mobile master units. Moreover, any value of three points of reference not in the same line and in communication range of each other from a respective mobile master units (or any stationary master or slave units, marker or source of a virtual coordinate reference) can be utilized to engage in a coordinated search for a desired, predetermined or designated target T as is shown in FIG. 38A. Accordingly, under such system where (i) every mobile monitoring or master units designated as a Mref is equipped with an electronic compass, (ii) a Cartesian coordinate system is established—a North—South and East—West coordinate system—with one of the stationary monitoring or master units Mref at the origin of the Cartesian coordinate system, (iii) coordinates of any two other stationary monitoring or master units Mref are identified in such established Cartesian coordinate system or, alternatively, (iv) such searching monitoring unit Ms is capable of is capable of (a) measuring and storing the distance between successive movements or accepting such distance as an input as well as (b) measuring and storing the direction of movement relative to one axis of such established Cartesian coordinate system such as, for example, North, and (v) every mobile monitoring or master units designated as a Mref can be displayed on the unit interface such as, for example, (a) on a scaled or polar coordinate grid together with target T and the mobile monitoring or master units own positions, (b) traces of movement on a scaled or polar coordinate grid indicating the target T and or the mobile monitoring or master units, (c) bearing angle of current indicating movement of the target T and or the mobile monitoring or master Units Mref relative to the North axis or, alternatively, bearing angle movement of the mobile monitoring or master units Mref relative to the target T (from Mref to T) relative to the North axis and other related information. Multiple bearings also can be displayed such as, for example, a value of the bearing angle of one or more of the other mobile monitoring or master units Mref relative to the target T relative to the North axis. Accordingly, such searching monitoring unit Ms can determine a value for a bearing angle relative to the target T from a value relative to one axis of such established Cartesian coordinate system—for example the North axis—when searching monitoring unit Ms is in its original position and, thus, there would be no need for an initial searching monitoring unit Ms movement described above. Of course, at the same time, respective mobile monitoring or master units can be utilized as being a part of the reference system according to the various techniques described for the present invention, for example, virtual triangulation, virtual coordinate system or the like. As is shown in to FIGS. 38A and 38B, the adaptive, dynamic mobile network configured for a coordinated search using multiple mobile monitoring or master units for multiple functions such as, for example, as points of reference, making such search process interactive, e.g. utilizing the additional functionality of monitoring or master units such as, for example, the transceiver functions to transmit and receive data and or values for position information, for full duplex communications, and reduction of position ambiguity. The starting point is to determine three values of any such points of reference of any of the mobile monitoring or master units not in a straight line and or in communication range. Any three values of such points of reference from such mobile monitoring or master units can be used for and or to engage in a coordinated search, movement, tracking, finding or other coordinated activity with respect to the Target T, all the while such mobile monitoring or master units are part of the reference system for another searching monitoring units Ms (not shown in FIG. 38A). The system and methods of the present invention, accordingly, can be used to control numerous mobile master references searching for numerous targets T provided that there is a combination of three or more transceivers and or transponders in the communication range. For example, three mobile points of reference from units (monitoring, master or slave) Mref are shown as A, B and C. Designating one unit Mref at the origin of a Cartesian coordinate system, the positions are known of the two remaining mobile units Mref and, also, the determined value of the distance measured mobile units Mref (A, T); (B, T) and (C, T). From this position information, the coordinates of the desired target T may be determined and, based on such position information, each mobile units designated as a Mref can calculate the bearing angle to the target T relative to a coordinate axis to determine its direction or movement, for example, the North axis. Once a particular mobile unit Mref has moved for some time (or distance) in a particular direction, such mobile unit Mref can (i) generate a value for the distance traveled (actual measurement or accept input from other units or from the user) and (ii) generate a value for the bearing or the measure of the angle of movement (relative to North axis). Consequently, such mobile unit Mref can generate new coordinates and or update the initial system of coordinates used by other units in communication range. Such new coordinates determined by such mobile unit Mref can be used to determine the target T coordinates in the same initial system of coordinates, for example, the next point in time, as is shown in FIG. 38B. This configuration allows for each mobile monitoring or master units Mref to search independently for a predetermined target T. However, all three mobile monitoring or master units Mref can be used to determine the target T coordinates at any given time. Finally, each mobile monitoring or master units Mref can determine and share its own coordinates in the established system of coordinates to other units and its own coordinates respective of the target T coordinates such that each mobile monitoring or master units Mref can determine the bearing angle to the target T relative to the North axis; also in the established coordinate system, the coordinates of other searching monitoring units Ms can be determined by the reference master units Mref, searching monitoring units Ms or in a distributed fashion. Multiple targets T and or units adaptively can be added to the mobile network established already during the search, tracking, finding, while conducting reference operations, or to accomplish other features of the present invention. At the beginning, new unit and or target T coordinates are calculated based on any three already established coordinates for masters units in the mobile network, whereby units serving as values for points of reference should be configured for measuring and storing the distance between successive movements, or accepting such distance as an input, as well as measuring and storing the direction of movement relative to one of the axis, for example, North. It should be appreciated that the already established coordinates system should remain constant during the search, tracking, finding, while conducting reference operations or to accomplish other features of the present invention, or otherwise regenerated based on steps 1-8 below. In operation, the established coordinates system of a mobile reference master unit configured with input from a compass, the determination of the value of the bearing angle designated (Alpha), relative to the North axis, is as follows, as is shown in FIGS. 38A and 38B: Generate a value based on the relationship Alpha=arccos((x2−X2)/R); Determine movement in the direction relative to the North axis, accordingly: If Alpha>90 and x1<X1 then the bearing value is <<(180-Alpha) degrees South—West>>; 1. If Alpha>90 and x1>X1 then the bearing value is <<(180-Alpha) degrees South—East>>; 2. If Alpha>90 and x1<X1 then the bearing value is <<Alpha degrees North—West>>; or 3. If Alpha<90 and x1>X1 then the bearing value is <<Alpha degrees North—East>>. Where R is the distance between searching monitoring unit Ms and the target T; x1 is the first (1st) value of the coordinate respective of target T; x2 is the second (2nd) value of the coordinate respective of target T; X1 is the first (1st) value of the coordinate of searching monitoring unit Ms; and X2 is the second (2nd) value of the coordinate of searching monitoring unit Ms. Additionally, the determination of the value of the bearing angle is guided by the principle that the larger the first coordinate, the more to the East is the object and the larger the second coordinate, the more to the North is the object, and so forth. For a mobile reference master that is moving relatively the North axis in an angle Alpha, new coordinates calculation between two points in time are conducted according to conditions 1 through 4. Selecting a new direction, or regenerating the coordinate system, that units are using for selecting direction relative to the North axis, can be determined using steps 5-8, as follows: 5. X1 new=X1−SIN(Alpha)*d, X2 new=X2 −COS(Alpha)*d 6. X1 new=X1+SIN(Alpha)*d, X2 new=X2 −COS(Alpha)*d 7. X1 new=X1−SIN(Alpha)*d, X2 new=X2 +COS(Alpha)*d 8. X1 new=X1+SIN(Alpha)*d, X2 new=X2 +COS(Alpha)*d Where d is the value of the distance that was covered by point of reference of the unit mobile monitoring or master unit between two points in time. It should be appreciated that: a) Determining any of the Target T, mobile points of reference Mref, and searching monitor Ms coordinates can be based on circles intersections or on polar coordinate principles. b) Other monitoring or master units and or users that do not serve as points of reference: i. will not need to measure the distance between their own successive movements or accepting such distance as an input; ii. similarly, search monitoring or master unit operations will closely resemble the search operations of stationary master references, for example, such units can choose to participate, to use or not to use compass input or the like for determining the bearing on the target and calculate the bearing angle to the target accordingly; iii. as above, searching monitoring or masters units Ms can interface with the user so as to display a scaled grid or polar coordinates with target T and searching monitoring or masters units Ms as well as traces of movement When searching monitoring or masters units Ms and or a target T fall outside of the communication range of the master units Mref (stationary or mobile), other units within the communication range of the reference master units Mref, searching monitoring or masters units Ms, and or target T can be used as an intermediate position reference to determine coordinates in the system of coordinates that is formed by the above mentioned reference masters that are out of the communication range. Upon request, the searching monitoring or masters unit Ms will communicate with all available units to form at least three intermediate master units to obtain values of points of reference that will be used form an intermediate virtual system of coordinates such as, for example, forming a hierarchical, reference table of values for the system of coordinates of three stationary master units in the range of the searching monitoring unit Ms and designated target T. Thereafter, these formed system of coordinates and the hierarchical, reference table of values for the previous system of coordinates can be used as a transfer function to translate values of points of reference “out of range” reference base on, for example: 1. The coordinates of the “out of range” points of reference for the translated system of coordinates to such the intermediate points of reference for newly located units within range, 2. Selecting one of such units as the origin of the intermediate virtual system of coordinates, 3. Selecting one of the two of the remaining units for the translated system of coordinates to such intermediate points of reference for the abscissa X (or Y) in the intermediate virtual system of coordinates, 4. Determining transfer functions or otherwise matrix translations of points or reference from such system of coordinates to such intermediate system of coordinates having points of reference in order to determine the angle of rotation between the original and the intermediate coordinates. This hierarchical referencing may be continued further and extrapolated, thus covering a large area and distances. Furthermore, units can be used as points of reference for three monitoring units Ms and a target T in range can be in a mobile network. Referring to FIG. 14, which is a process flow diagram for Technique 3, Mobile Network For Finding, can be used in high speed search and rescue operations, tracking multiple targets, whether animate subjects or inanimate objects, utilizing a coordinated search by multiple master units, fixed or mobile. An example of a distance determination process using technique 3 is illustrated in FIGS. 16-19. Referring first to FIG. 16, the relative positions of a target T and a monitoring unit or searching monitor Ms are shown with respect to virtual coordinates X and Y. Each target has virtual coordinates are Ty and Tx. The virtual coordinates for the searching monitor are Msx and Msy. In this example, technique 3 employs the process of technique 2 utilizing master units M1, M2 and M3 as reference units as shown in FIG. 16, for example. Reference unit M1 is separated from reference unit M2 by a distance D1,2. Reference unit M1 is separated from reference unit M3 by a distance D1,3. Reference unit M2 is separated from reference unit M3 by a distance D2,3. The distances between the searching monitor SM and the reference units M1, M2 and M3 are Ms_R1, Ms_R2 and Ms_R3, respectively. The distances between the target T and the reference units M1, M2 and M3 are T_R1, T_R2 and T_R3, respectively. To avoid position determination ambiguity, the three stationary master units M1, M2 and M3 which are used as reference units preferably should not be located along a straight line as discussed above with reference to FIGS. 7-10, for example. Moreover, the distances D1,2, D1,3 and D2,3 should be large enough to minimize ambiguity error as discussed above with reference to FIGS. 9-11, for example. In some embodiments, the preferable separation distances can be stored in the memory of the master unit and displayed automatically by the searching monitor when entering into technique 3 mode. With reference to FIG. 14, the process is entered into in path A, block 290, which enables the homing standby mode. As described above for techniques 1 and 2, the monitoring unit or searching monitor periodically checks the monitoring units having responsibility for the target to determine whether all of the targets being monitored are within the prescribed range. Whenever a target moves out the prescribed range, the homing mode is automatically initiated. Path B, block 291, determines if reliable communication can be established between the searching monitor Ms and the reference units M1, M2 and M3, as well as between reference units M1, M2, M3, the searching monitor Ms and the target T. If not, the user moves to a new location, as represented by block 292 and the flow returns to block 291 to determine if reliable communications can now be provided between the searching monitor and the reference monitors. When reliable communications are established, flow proceeds to decision block 293 which determines whether the targets being monitored are within the prescribed range. If so, the searching monitor Ms provides a suitable prompt to the user, block 294, and flow normally returns through block 295 to block 291. Blocks 293-295 form a wait loop that continuously monitors the target units to detect when a target being monitored moves of range, block 295 enables the user to force entry into the homing mode. When a target moves out of range, or if forced entry into the homing mode is requested by the user, flow proceeds to Step 3, block 296, which obtains the searching monitor and target unit distances relative to the reference units M1-M3. The distances between the reference units M1, M2 and M3 can be measured (by the monitoring units themselves) or have fixed values that are entered into a “searching monitor unit Ms” during the initialization phase. The three position reference units M1, M2 and M3 do not have to be stationary. For example, members of a search team can carry these units, the members of the search team may be moving relative to one another in conducting the search. Whether the units are stationary or not, there may be three or more monitoring units in the field. As result, at any given moment, a combination of any three monitoring units can be used as the position reference. Such arrangement can be used for conducting multiple simultaneous automated high-speed searches. It is also impervious to obstacles and is very precise. One possible application is for locating individuals in a theme park. Other possible applications include a search and rescue operation that has to be conducted in a very short time and or at high speed, or a search operation when only a few master units are monitoring a large number of targets. Flow proceeds to path E, block 297, which determines the relative distance between the searching monitor Ms and the unit carried by the target T. In response to a request initiated by a user of a master unit 21, the three position reference units provide outputs indicative of the distance between all master units as well as distance between master units M1, M2 and M3 and target children, such as target T. Based upon this information, the positions of all reference units M1, M2 and M3 and targets are calculated relative to “virtual” coordinates that are formed by any three monitoring or reference devices M1, M2 and M3. The virtual coordinates are mapped into a grid so that the relative positions between all monitoring units and the targets relative to each other are displayed on the grid, block 298, as well as the positions of other reference or monitoring units. Referring to FIG. 17, the positions of the target T, the searching monitor Ms and the three reference units M1, M2 and M3 have been rotated for mapping into a display grid. Every position and virtual X,Y coordinate is rotated. However, the relative positions between all of the monitoring units Ms, M1, M2 and M3 and the target T are unchanged. Mn—Y and Mn—X (where n=1, 2, 3) are stationary reference virtual coordinates. The coordinates of reference units M1, M2 and M3 can be calculated from the distances D1,2, D1,3 and D2,3. The coordinates Ty and Tx for the target T can be calculated from the distances T_Rn and the coordinates Mn—Y and Mn—X of the reference units M1, M2 and M3 (where n=1, 2, 3). The coordinates Msy and Msx for the searching monitor Ms can be calculated from and the coordinates Mn—Y and Mn—X of the three reference units M1, M2 and M3 and the distances Ms_R1, Ms_R2 and Ms_R3. Referring again to FIG. 14, flow proceeds from block 298 of path E to path F, block 299, which evaluates conditions such as whether the target is within range, block 300, and whether the distance between the searching monitor and the target calculated is within an ambiguity error zone, block 304. If block 300 determines that the target is outside of the range, flow returns to Path B. Otherwise, the target is within range, the user is prompted to that effect, block 301, and flow proceeds to decision block 302 which determines whether the user has forced the homing operation. If the user has not forced the homing mode and if the target is now within range, the homing mode is exited, block 303, and flow returns to Path A to await the next time a determination is made that a target has moved out of range. If the user has forced the homing mode, flow proceeds to decision block 304 which determines whether the distance calculated places the searching monitor within the ambiguity error zone. If the searching monitor is not within the ambiguity error zone, flow returns to Path B. If block 304 determines that the searching monitor is within the ambiguity error zone, the user is prompted, block 305, prior to the flow returning to path B. Referring to FIG. 18, the virtual coordinate information allows the searching monitor and target to be mapped onto a display grid of the master unit 21. In some embodiments, illustrated in FIG. 18, only relative positions for the target and the searching monitor Ms, including the initial position for the searching monitor Ms, are displayed. Also, the relative positions of other units C1 and C2 can be shown. In the case of three stationary monitoring or reference units M1, M2 and M3, optionally, these may or may not be displayed on the grid shown in FIG. 18. In addition, the original in-range circle 25 (FIG. 1) and the original position of the searching monitor Ms (which can correspond to master unit 21 in FIG. 1) can be displayed on the grid as shown in FIG. 18. The scale of the display can be set automatically or be set by the user. The “searching monitor Ms” can determine it's own position relative to the reference units M1, M2 and M3 as well as the target's position relative to the reference units M1, M2 and M3. Consequently, the searching monitor Ms can also determine its own position relative to the target without a need for establishing its own three-point coordinates for the example for three stationary master units M1, M2 and M3 shown in FIGS. 16, 17 and 18. As a result, a searching monitor Ms need not move in a pattern. Although there are many possible ways of defining virtual coordinates, in every instance, the result will be the same. Also, the “virtual” coordinates do not need to be displayed on a grid. It should be noted that several search operations are carried out simultaneously real-time (three simultaneous operations are shown in FIG. 19. The accuracy of measurements does not depend upon the speed of the target. Also, displaying on a “grid” the position of the searching monitor Ms and the positions of the other monitoring units relative to the position of the target or targets, gives operator the ability to perform an interactive search, no matter what the speed of the target or targets. This also improves productivity as only few operators can oversee many targets such as, for example, FIG. 19. FIG. 19 shows an example of the use of the homing Method 3 when the reference monitors M1-M3 are moving. However, a stationary reference unit, such as a stationary target unit CU, is located at the center of the “range” circle 25. M1—I, M2—I, and M3—I, represent the initial positions of the reference monitors M1, M2 and M3, and M1—C, and M3—C, represent current positions of the reference monitors M1 and M3, respectively (reference monitor M2 not having moved) Ms_I is the original position of the searching monitor Ms and Ms_C is the current position of searching monitor Ms. D1 is the distance from the current position of the searching monitor and the target T1, D2 is the distance from the current position of the monitor M1 and the target T2. The manner in which these are determined is similar to that described above for the example in which the locations of the reference monitors M1, M2 and M3 are fixed. In addition, in case of mobile reference monitors, each reference monitor and the search monitor may have to be equipped with a compass, GPS input or any other device that helps to establish an actual or absolute direction or position reference. Also, the traces (consequent positions) of monitors M1, M2 and M3, searching monitor Ms and target units T1 and T2, as well as anticipated direction(s) of movements of these units are displayed. The master unit 21 can also improve the target position determination accuracy and speed by combining its own measurements with the measurements of the other monitoring units M1, M2 and M3, which can include master units 22, 23 and 24, for example, as is shown in FIG. 1. Similarly, several operators can organize a coordinated real-time search for a very fast moving target, a target that is moving faster than an operator, as positions of the target and all monitoring units participating in the search can be displayed on the grid as is shown in FIG. 19. Also, a numerous master units 21 can effectively monitor many targets having units disposed on the subject, object, or both. As is stated above, FIG. 19 illustrates the case where the position reference monitoring units are moving. Here one monitoring unit 21, for example, a team leader, (shown as “searching monitor unit” Ms), is arbitrarily designated the searching monitor Ms that periodically requests distance measurements from other three moving monitoring or reference units 21. The searching monitor Ms processes the ilformation in a similar fashion that is in case of three stationary monitoring units, and broadcasts the display information to the other monitoring or reference units (shown as M1, M2 and M3). This allows providing a coordinated search for a single target or a plurality of targets. When all of the reference monitoring units are moving, there is a chance that at some point, the reference units M1, M2 and M3 (or two of the reference units and the searching monitor Ms) might end located along a straight line. However, as described above, the searching monitor Ms displays the relative positions of the reference units and so the traces will indicate to the searcher that the reference units are moving in directions toward alignment along a straight line. In such case, the searcher can send a voice communication to the reference units to warn the other operators to change the direction in which they are moving. It should be noted that several groups of monitoring units can conduct a simultaneous independent real-time search for multiple targets. Because all of the monitoring units are moving, the original in-range circle position cannot be preserved unless a stationary slave unit is used as position reference. In such case, the original in-range circle can be displayed in proper relation to the positions of all of the monitoring units and the target units carried by subjects or disposed on objects. Referring to FIG. 37, in yet another exemplary embodiment of the present invention, a dynamic, mobile network of master and slave units capable of locating objects and or subjects as the mobile network moves. If a target being tracked moves out of the range of a monitoring unit that is principally engaged with tracking such target, such monitoring unit may nonetheless find such target by making a request to other master units, fixed or mobile, to find the target. Such method of finding a target in a network of master units, fixed or mobile, can be accomplished by the monitoring unit requesting a list of targets (-ID's) in the range of each master unit within the range of the monitoring unit. The master unit receives the request from the monitoring unit and determines the targets in the range and their unique identification. Once a list of the targets identified in the area of the particular master unit receiving the request, the master unit sends each identity to the monitoring unit. The monitoring unit can identify the particular target such as, for example, from the ID or from last known position and rate information correlated with the position of the master unit sending the list, thereby locating the target. The method is adaptable such that the monitoring unit can hand off the principal responsibility of monitoring such target to a master unit so as to create a dynamic locating and tracking network. Global Positioning Systems (GPS) are useful in determining the location of a “receiving device” to within about 50-100 meters; however, in certain environments such as covered or enclosed buildings, dense forest, bad weather, and the like, GPS cannot operate well or at all. In a further application of the present invention, the tracking and locating system 20 can be seamlessly integrated to a GPS chip-set to utilize serial information data of GPS. This is because the present invention search techniques 1-3 can use the control processor to operate on RF distance measurement data obtained by the technology of the present invention as well as data obtained by the GPS-based technology. A GPS receiver antenna can be separate or combined with the master or slave antenna. Thus, providing the user with a unified man-machine interface, as described in the present invention, regardless of technology that is used to collect the position data. Such system is adaptable to operating in adverse environments and, on a very cost effective per person basis, provide tracking and location functionality with an easy to understand the present invention graphical user interface (GUI). In applications which include GPS-based technology, the operation of the tracking and locating system 20 can be similar to that described above using the homing techniques 1-3. In another application, the slave unit can be embedded into an object, for example, a golf ball or a document. In this application, the slave unit is stripped of all man-machine peripherals and interfaces (such as keys, microphone, speaker or headset plug, LEDs, switches, etc.) and its electronics are integrated together with a small rechargeable battery into a golf ball. The battery can be re-charged without contact using an electromagnetic field, for example. A micro-machined switch that is turned on by a certain acceleration forces is used as a power-on switch. This switch can turned off in response to a command signal transmitter by the master or monitoring unit. When the golf ball is hit with a force that exceeds a certain threshold, the power switch is turned on, powering the embedded electronic circuits. In this application, the operation of the golf ball tracking and locating system 20 in locating golf balls can be similar to that described above using to the homing techniques 1-3. Although exemplary embodiments of the present invention have been shown and described with reference to particular embodiments and applications thereof, it will be apparent to those having ordinary skill in the art that a number of changes, modifications, or alterations to the methods and system of the present invention may be made, none of which depart from the spirit or scope of the present invention that is described herein according the exemplary embodiments. For example, virtual triangulation can be used to find an object or subject using the display and auditory instructions. Other methods of finding broadly described in Techniques 1, 2 and 3 may be combined in various ways to form systems adapted to find the target with reduced feature sets according the requirements of a particular application. In other embodiments, mobile networks can be formed from one or more monitoring units and units disposed on targets T. Advantageously, these configurations can utilize virtual triangulation, however, the functionality of each monitoring unit provides additional values for position information from data resident in each unit. Moreover, the interface between the unit and the user can be adapted and further integrated. For example, the display and auditory commands given to the user can advantageously be configured according to simplified metaphors easily assimilated by the user so as to guide the user to the target using a spectrum of commands ranging from “hot” to “cold”, whereby variations of hot, hotter, hottest, and “you're on top of it” or “look around” can be given to the user as the user gets closer to the target or subject. Similarly, the display and auditory commands given to the user can advantageously be configured to guide the user to the target using a spectrum of commands ranging from “cold” “colder”, “coldest” and “you're an iceberg” or “start over” can be given to the user as the user gets further away from the target or subject. All such changes, modifications, and alterations should therefore be seen as being within the scope of the present invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates generally to locator systems and techniques, and more particularly, to finding systems for determining the location of objects and/or subjects. 2. Description of the Related Art Most systems for locating a subject or object employ the use of direction locating antennas to determine the position of the subject. However, such locating systems are characterized by shortcomings associated with the size of the antenna at the bandwidth that is optimal for the application. Direction locating antennas experience significant degradation of directional capabilities in close range conditions wherein the separation between a search unit and a target is about several hundred feet or less. It is well known that there is a correlation between antenna size and RF wavelength. A larger antenna is needed for a longer RF wavelength. The need for small antenna size forces the selection of relatively high frequency bands of 900 MHz and higher where there is a lot of interference in the form of reflections and where there is considerable signal degradation as the signal passes over small objects or obstacles. In short, relatively high frequency bands are not suited for searches where the separation between the search unit and the target is greater than a hundred feet. Moreover, the use of directional antennas precludes coordinated searches wherein several search units are homing in on a target or are tracking multiple targets. The use of directional antennas also precludes monitoring a plurality of subjects at the same time because a monitoring unit employing a directional antenna cannot receive and transmit signals in multiple directions. Because of significant directional errors that are associated with directional antennas, the operator also is required to have special skills in performing the search, i.e., locator systems employing directional antennas are not user friendly. Known locator systems rely on distance measurement to determine the separation between a monitoring unit and a subject whose location is being monitored. Distance measurement generally is carried out either by measuring signal strength or by measuring the propagation time between sending a ranging signal and receiving a ranging signal. Examples of systems that use signal strength to determine distance to locate a subject are disclosed in U.S. Pat. No. 5,086,290 and in U.S. Pat. No. 5,650,769, for example. Systems that rely on measurement of signal strength are prone to be unreliable due to noise, interference, signal strength changes, reflections, etc. as well as signal degradation as the signals pass over obstacles. Moreover, measurement error is a function of signal strength, whereby large signal attenuation typically occurs within a building as opposed to outside of a building. In these systems accuracy of measurement is distance dependent, whereby if the distance change is small such systems function appropriately, although, they are known to be less accurate at larger distances. Another system disclosed in U.S. Pat. No. 5,525,967 uses timing to determine distance. Time measurement does not rely on signal strength and is immune to the signal attenuation. Also, the distance measurement error is constant and does not distant depend signal attenuation. Some of the known time measurement locator systems rely on variations of directional antennas, for example a phase array antenna. Such variations allow the reduction of antenna size. However, the price for these improvements is a complex antenna design and an extremely complex signal processing requirements, which result in a lower accuracy, higher cost and power consumption. Also, such antennas are subject to operating frequency limitations and require a wide bandwidth. Known distance measurement systems that employ time-measurement techniques require a large bandwidth in order to achieve a desired accuracy. This results in increased interference, higher circuit complexity and power consumption as well as higher cost. Wide bandwidth requirements also limit the number of devices that can operate simultaneously within a given band. These devices have wide bandwidth requirements that have particular disadvantages such as, for example, such devices cannot operate on business or otherwise unlicensed bands that prohibit ease of the units to transmit and receive in an unregulated environment, limit the units from being sold “over the counter” or integrated with mass-produced popular hand-held radios. In U.S. patent Publication No. 2002/0155845, a position location system is disclosed that uses spread spectrum technology for determining range information in a severe multi-path environment. The system uses ranging processes wherein ranging pulses at eight different frequencies within a band are exchanged between a master radio unit and each of at least four reference radio units. The position and velocity information obtained by the ranging process enables determination of the position of the master radio's position in three dimensions. This system uses a variation of time-measurement based techniques for distance determination. As a result, it carries all of the drawbacks mentioned above plus its operation frequencies and or bands are limited. The system does not employ a directional antenna. Instead, it uses additional four fixed references with known coordinates, or four mobile references that have their coordinates continuously updated via GPS or manually. This system allows simultaneous operation of many units. In this system, the usage of a directional antenna is eliminated. However, the system has disadvantages that include adding a complex infrastructure requiring multiple references, fixed and or mobile, that all include GPS or otherwise need continuous manual updating of coordinate data; limited operating band; increased complexity of the system both technological and logistical; cost; and power consumption. As a result, the system has a very narrow usage in specialized applications. The present invention overcomes such disadvantages of the prior art to provide methods and devices for finding subjects and objects that reduce and or eliminate the infrastructure overhead, for example, the present invention operates without (i) usage of a directional antenna, (ii) any position references, and or (iii) operating band limitations so as to lower the complexity of the system and the overall cost of the devices. | <SOH> SUMMARY OF THE INVENTION <EOH>A wireless system and method for determining the location of a fixed or mobile subject or object includes a transponder disposed on the target, a transceiver for monitoring the location of the target, a wireless communication system operating on at least one Radio Frequency (RF) band configured to allow communication between the transponder and the transceiver, and a processor configured to find the target by virtual triangulation based on values of position information received from the transponder and the transceiver. The processor is configured to determine virtual triangulation based on successive values of the position information using at least three points P 1 , P 2 and P 3 of the transponder respective of the transceiver. The processor can include a successive pattern movement technique configured to find the target by correcting the direction to the location of the target T based on the values of the position information. The processor can also determine the position of the target based on the average speed of the motion of the user of the transponder respective of the transceiver. Furthermore, the processor can determine virtual triangulation based on successive values of the position information from user input on the transceiver. The present invention uses various methods, software, and techniques for finding the target T (“finder” techniques) based on one or more position determination principles including determining the position of the target using virtual triangulation between the master or monitoring unit and at least one target T, whereby the monitoring device M s measures the distance between it and the slave unit and, alternatively, in addition to measuring the distance between itself and the slave unit, between itself and another monitoring unit, or the monitoring device M s measures the distance between its own successive locations. The present invention relates to several methods for finding with virtual triangulation relates including: (1) finding with virtual triangulation by generating position information in real-time, in the case of (i) stationary and moving target, and or (ii) in the case of the presence of obstacles; (2) finding with virtual triangulation relating to the average speed of the motion of operator; and or (3) finding with simplified virtual triangulation, whereby the user-device interaction is minimized—eliminating the need for monitoring device M s to measure the distance between its own successive locations as well as the user's signaling to the monitoring or master unit when in motion or during stops. The present invention is further configured to provide the method for finding by virtual triangulation as well as for finding using a mobile network on a computer-readable medium having stored thereon a plurality of sequences of instructions, which plurality of sequences of instructions including sequences of instructions, when executed by a processor, cause said processor to perform the steps of determining a value of a point P 1 from position information received by a transceiver corresponding to a location of a transponder disposed on a target. The user is prompted for a transceiver or a predetermined transceiver to move to a point P 2 relative to a location of the target. Another value of a point P 2 is determined from position information of the transceiver or predetermined transceiver corresponding to a location of the transponder. Another request is made for a value of a point P 3 of the transceiver or of point P 2 of the predetermined transceiver corresponding to a location of the transceiver or the predetermined transceiver. The target is found using virtual triangulation principals in accordance with each of said values for said points P 1 , P 2 and P 3 . | 20040224 | 20100831 | 20050127 | 94626.0 | 0 | BEAMER, TEMICA M | SYSTEM AND METHOD FOR LOCATING A TARGET USING RFID | SMALL | 0 | ACCEPTED | 2,004 |
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10,786,449 | ACCEPTED | Long term rapid color changing time indicator | A long term rapid color changing time indicator includes a front part and a back part. The front part includes a transparent layer, an opaque layer, a colorant layer, and a neutralizing layer. The colorant layer includes a matrix and a colorant having a non-migratory form that does not migrate in the matrix and having a migratory form that migrates in the matrix. The back part has a reactant. When the front part and the back part are placed in contact, the reactant migrates into the neutralizing layer and a portion of the reactant is depleted by a coreactant. The unreacted reactant migrates into the colorant layer and reacts with the non-migratory form of the colorant converting the non-migratory form to the migratory form such that the migratory form of the colorant migrates through the opaque layer to cause a visual color indication in the transparent layer. | 1. A time indicator comprising: a front part comprising an opaque layer and a colorant layer in contact with the opaque layer at an interface, the colorant layer comprising a matrix and a colorant in the matrix, the colorant having a non-migratory form in which the colorant does not migrate in the matrix to the interface and a migratory form in which the colorant migrates in the matrix to the interface; and a back part comprising a reactant capable of migrating in the colorant layer, wherein, when the front part and the back part are placed in contact, the reactant migrates into the colorant layer and reacts with the non-migratory form of the colorant converting the non-migratory form of the colorant to the migratory form of the colorant such that the migratory form of the colorant migrates to the interface and through the opaque layer to cause a visual color indication in the front part. 2. The time indicator of claim 1 wherein: the non-migratory form of the colorant is an ionomer dye. 3. The time indicator of claim 2 wherein: the matrix comprises a pressure sensitive adhesive. 4. The time indicator of claim 1 wherein: the non-migratory form of the colorant includes an acid group, the reactant has a basic pH, and an acid-base reaction between the non-migratory form of the colorant and the reactant converts the non-migratory form of the colorant to the migratory form of the colorant. 5. The time indicator of claim 4 wherein: the acid group is a sulfite group. 6. The time indicator of claim 4 wherein: the reactant is an amine. 7. The time indicator of claim 1 wherein: the front part further comprises a transparent layer in contact with the opaque layer at a surface of the opaque layer opposite the interface. 8. The time indicator of claim 7 wherein: the transparent layer comprises a transparent substrate and a transparent adhesive providing adhesion between the transparent substrate and the opaque layer. 9. The time indicator of claim 1 wherein: the front part further comprises a neutralizing layer in contact with the colorant layer at a surface of the colorant layer opposite the interface, the reactant is capable of migrating through the neutralizing layer to the colorant layer, and the neutralizing layer includes an amount of a coreactant that reacts with an amount of the reactant to form a reaction product such that at least a portion of the reactant entering the neutralizing layer does not migrate into the colorant layer. 10. The time indicator of claim 9 wherein: the coreactant has a pH opposite to that of the reactant, and an acid-base reaction forms the reaction product. 11. The time indicator of claim 10 wherein: the reactant is an amine, and the coreactant is an acid. 12. The time indicator of claim 9 wherein: the reactant is a reduced species, the coreactant is an oxidizing agent, and an oxidation-reduction reaction forms the reaction product. 13. The time indicator of claim 9 wherein: the front part further comprises a timing layer in contact with the neutralizing layer at a surface of the neutralizing layer opposite the colorant layer, and the reactant is capable of migrating through the timing layer to the neutralizing layer. 14. The time indicator of claim 13 wherein: the timing layer comprises a material selected from the group consisting of pressure sensitive adhesives, hydrogels, polymer resins, and mixtures thereof. 15. The time indicator of claim 13 wherein: the timing layer comprises a polymer resin and a plasticizer. 16. The time indicator of claim 1 wherein: the back part further comprises a base substrate in contact with the reactant. 17. The time indicator of claim 1 wherein: the opaque layer has an acidic pH, and the colorant that migrates into the opaque layer undergoes a color change due to the acidic pH. 18. A time indicator comprising: a front part comprising an opaque layer, a colorant layer in contact with the opaque layer at an interface, a neutralizing layer in contact with the colorant layer at a surface of the colorant layer opposite the interface, and a transparent layer in contact with the opaque layer at a surface of the opaque layer opposite the interface, wherein the colorant layer comprises a matrix and a colorant in the matrix, the colorant has a non-migratory form in which the colorant does not migrate in the matrix to the interface and a migratory form in which the colorant migrates in the matrix to the interface; and a back part comprising a reactant capable of migrating in the colorant layer and the neutralizing layer, wherein, when the front part and the back part are placed in contact, the reactant migrates into the neutralizing layer and an amount of the reactant reacts with an amount of a coreactant in the neutralizing layer to form a reaction product such that at least a portion of the reactant entering the neutralizing layer does not migrate out of the neutralizing layer, and wherein unreacted reactant migrates into the colorant layer and reacts with the non-migratory form of the colorant converting the non-migratory form of the colorant to the migratory form of the colorant such that the migratory form of the colorant migrates to the interface and through the opaque layer to cause a visual color indication in the transparent layer. 19. The time indicator of claim 18 wherein: the front part further comprises a timing layer in contact with the neutralizing layer at a surface of the neutralizing layer opposite the colorant layer, and the reactant is capable of migrating through the timing layer to the neutralizing layer. 20. The time indicator of claim 18 wherein: the reactant is a base, the coreactant is an acid, and an acid-base reaction forms the reaction product, and the non-migratory form of the colorant is an ionomer dye. 21. The time indicator of claim 20 wherein: the reactant is an amine, and the ionomer dye includes a sulfite group. 22. The time indicator of claim 21 wherein: the matrix comprises a pressure sensitive adhesive. 23. The time indicator of claim 20 wherein: the reactant is included in a reactant layer comprising a pressure sensitive adhesive. | CROSS-REFERENCES TO RELATED APPLICATIONS Not Applicable. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH Not Applicable. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a time indicator and, in particular, to a long term time indicator which provides a rapid and clear indication of expiration. 2. Description of the Related Art Numerous devices are known which provide, after activation, a visual indication of the passage of a predetermined amount of time. Such a time indicator is useful, for example, as a security badge, as an indicator of the length of time a perishable item has been on the wholesaler's or retailer's shelf and for numerous other uses. Some known time-indicating devices involve the migration of a colorant, dye or other material through a media. Many of these known time indicators, which are generally short term time indicators, are based on the migration of ink from one substrate through another substrate, i.e., in a path perpendicular to the surface of the substrate. After the ink diffuses for a time period through the substrate(s), it is viewed on a display surface to thereby indicate that the predetermined time has elapsed. Examples of this diffusion technology can be found in: U.S. Pat. No. 4,212,153 which describes a time indicator where a dye migrates to the surface of an indicator badge; U.S. Pat. Nos. 5,446,705 and 4,903,254 which describe the use of an ink dissolver layer in a time indicator; U.S. Pat. No. 5,058,088 which describes the concept of varying ink dot size and spacing to change the time indication period; U.S. Pat. No. 5,602,804 which describes a time indicator with control of lateral migration; U.S. Pat. Nos. 5,633,835 and 5,822,280 which describe the use of an organic liquid to dissolve a barrier layer and allow for dye migration; U.S. Pat. No. 6,295,252 which describes the use of an accelerator in an adhesive layer; U.S. Pat. No. 6,452,873 which discloses the enablement of dye migration by use of a plasticizer, U.S. Pat. No. 6,514,462 which describes the use of rubber polymers as the diffusion layer in a time-temperature indicator; and U.S. Patent Application Publication No. 2003/0053377 which describes the migration of an amorphous material into a porous matrix when the materials are brought together. Technologies based on dye diffusion are typically useful for short time intervals such as days or weeks. They are usually not useful for longer time intervals such as months because the color change occurs by gradual dye diffusion which begins the instant the activating adhesive cover is applied over these printed dyes. The time indicator may stay pure white for about a month and then start to gradually change color. During the time interval of gradual color change, the time indicator is in a “gray area” between absolutely YES and absolutely NO. This lack of a sharp transition time is a problem with simple dye diffusion systems. Other indicators in the prior art rely primarily upon chemical reactions to cause a visually perceptible change over a desired time period rather than merely the migration of fluids or compounds. U.S. Pat. No. 5,045,283 lists various color change reactions that are suitable for time indicator devices. In one example, U.S. Pat. No. 5,045,283 describes the use of acid or base reactant depletion before trigger of an indicator or to control diffusion. U.S. Pat. Nos. 5,085,802 and 5,182,212 also describe the concept of acid or base reactant depletion before trigger of an indicator. U.S. Pat. No. 6,254,969 describes the similar concept of oxygen depletion before trigger of an indicator. U.S. Pat. No. 6,544,925 discloses the use of co-reactants for color formation in a time-temperature indicator system. The aforedescribed devices are often complicated to adjust for a selected period of time. Adjustments often involve experimentation with many types of chemicals, inks, solvents, etc. to prepare a device which can operate under the conditions expected. Most of the prior art devices gradually change color over a period of time and involve, at best, a guess on how much time has elapsed. When this is combined with the possible variations in temperature, humidity, etc. that may exist in the environment of the time indicator, the viewer may have very little confidence that he is close to the expiration time of the device. Therefore, there remains a need for a long term time indicator wherein the dye does not begin to appear until the end or near the end of the time interval. Such a time indicator would remain unchanged (white or clear) until near the end of the time interval, and then the color would rapidly or, ideally, instantaneously appear. In essence, what is desirable is a time switch (a color-appearing step-function from white to dark), which stays white until the end of the time interval and then produces a step-function, meaning an instantaneous or rapid color change to clearly show that the time interval has ended. The time indicator would solve the problems with longer term indicators that suffer from an extended “gray time” where there is a slow change in the indication color. The time indicator would allow for a reduced “gray time” for a longer term indicator. SUMMARY OF THE INVENTION The foregoing needs are met by a time indicator according to the invention. The time indicator rapidly changes color after a specified time. The time indicator system includes: a back part having a base substrate and a migrating reactant in or on the base substrate; and a front part having a timing layer, a neutralizing layer, a colorant layer, an opaque layer, a transparent adhesive enhancement layer, and a transparent front substrate. When the time indicator is activated by placing the timing layer of the front part and the reactant of the back part in contact, the reactant begins to migrate through the timing layer and to the neutralizing layer at a known rate. In one form, the neutralizing layer contains a counter pH agent that neutralizes the reactant. The timing layer is optional and may be needed for controlling the migration rate of the reactant and to extend or vary the timing as needed by the application. There is an excess of reactant compared to the neutralizing agent. The reactant migrates to the neutralizing layer and the acid or base is neutralized by the neutralizing agent. After the neutralizing agent is depleted, the reactant migrates to the colorant layer. The colorant layer has a colorant in a matrix. The colorant has a non-migratory form in which the colorant does not migrate in the matrix and a migratory form in which the colorant migrates in the matrix. The reactant combines with the non-migratory form of the colorant and converts the colorant to its migrating form. After conversion, the colorant migrates through the colorant layer and the opaque layer and can be seen by the user in the transparent front substrate. The time indicator according to the invention rapidly changes from a secure to an unsecure state (i.e., a color change is visible) after a well-defined delay time. In order to accomplish this, the timing control (induction time or delay period) and color change mechanisms (the rate of switching to an “alarm” state) are independently controlled. Previous devices used the timing control process and the color changing process to be the same. This invention separates the timing process and the color changing process. The time indicator is a three-step process. First is the activation process, followed by the timing process and then the color changing process. The activation process is a separate process, which is started by the end user, activated by allowing the front and back parts of the time indicator to come together. Indicators in which the timing process and the color changing process are combined have indications that are not very clear to the user, that is, a gradual color appearance. Very problematic are prior indicators of long periods wherein the timing process is as long as the color change process, making it difficult to distinguish a clear endpoint. Prior devices where a visual message becomes either visible or obscured are based on diffusion of a dye or an activator, which controls both the timing control process and the color changing process. The present invention overcomes these difficulties. The mechanism for the color change is separate from the mechanism to impart a time delay period so that the colorant remains immobilized until contacted by the reactant, which then allows the colorant to migrate very rapidly through the opaque layer and be seen by the end user. It is therefore an advantage of the present invention to provide a long term time indicator wherein the dye does not begin to appear until the end or near the end of the time interval. It is another advantage of the present invention to provide a time indicator that remains unchanged (white or clear) until near the end of the time interval, and then the color rapidly or instantaneously appears. It is yet another advantage of the present invention to provide a time indicator that acts as a time switch with a color-appearing step-function from white to dark to clearly show that a time interval has ended. It is still another advantage of the present invention to provide a time indicator that utilizes separate timing control and color change mechanisms to eliminate the problems associated with gradual color change in longer term time indicating devices. These and other features, aspects, and advantages of the present invention will become better understood upon consideration of the following detailed description, drawings, and appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a cross-sectional view of one embodiment of a time indicator according to the invention prior to activation. DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a time indicator that utilizes separate timing control and color change mechanisms. It utilizes either acid-base or oxidation-reduction reactants to migrate into and neutralize in a separate layer and then the excess migrates further, reacting with a non-migrating colorant. The non-migrating colorant reacts to a migrating colorant which then migrates through an opaque layer to a display layer. Utilizing this approach, an indicator can be made which allows for longer time periods (e.g., about 30 to 60 days) until initial readability with a distinct end point. Turning now to FIG. 1, there is shown an example embodiment of a time indicator according to the present invention. The time indicator is provided in two parts, a front part (activator) 1 and a back part 2. The term “front” part is used herein to indicate the part which is viewed by an end user and does not limit the orientation of the time indicator in space. The front part 1 includes a transparent substrate 3 or sheet such as polyester or acetate film. Attached to one side of the transparent substrate 3 is a transparent adhesive referred to as the enhancement layer 4. Together the transparent substrate 3 and the enhancement layer 4 form a transparent layer. Attached to the enhancement layer 4 is an opaque layer 5 which functions to hide a colorant that is contained in the attached colorant layer 6. The colorant layer 6 includes a colorant (e.g., dye molecule) that does not migrate in its initial non-migratory form in the matrix comprising the colorant layer 6. After a predetermined time and a reaction, this colorant will change form and become a migrating colorant. The layer adjacent and attached to the colorant layer 6 is a neutralizing layer 7. The bottom layer of the front part 1 is a timing layer 8. The timing layer 8 may not be required if the timing is sufficient without the timing layer 8. The timing layer 8 may be an adhesive layer and/or the neutralizing layer 7 may be an adhesive layer used to attach it to the reactant layer 9 described below. An optional release liner may be attached over the timing layer 8 or the neutralizing layer 7 for ease of handling before activation. The back part 2 consists of a base substrate 10 such as paper or polymer film. On one side of the base substrate 10 is a reactant layer 9. This layer 9 contains a migrating reactant such as an acid or base that migrates upward into the front part 1. The reactant layer 9 may be a continuous layer of the migrating reactant or may comprise discrete or dispersed regions of the migrating reactant. If the last bottom layer in the front part 1 is not an adhesive layer, then reactant layer 9 includes an adhesive. An optional release liner may be attached over the reactant layer 9 for ease of handling before activation. Upon activation, the timing layer 8 of the front part 1 is placed into contact with the reactant layer 9 of the back part 2. The migrating reactant in reactant layer 9 will gradually migrate through the timing layer 8 into the neutralizing layer 7. At the neutralizing layer 7, the migrating reactant will react with a neutralizing agent in the neutralizing layer 7. The neutralizing agent is in an opposite form (coreactant) than the migrating reactant. If the reactant is an acid, then the neutralizing agent is a base or vice versa. The result of the reaction of the reactant and coreactant is a neutral reaction product. The reactant continues to migrate in the neutralizing layer 7 at a known rate. After a specified time, the neutralizing agent is depleted. The reactant will then be able to migrate into the colorant layer 6. Thus, diffusion of the reactant through the timing layer 8 and the neutralizing layer 7 provides a timing control mechanism. Once the reactant meets a non-migrating colorant in the colorant layer 6 and reacts, the colorant will change form. The colorant will change from a non-migrating colorant to a migrating colorant. The colorant can change by several means such as: acid/base neutralization, oxidation/reduction reaction, or similar reaction. The preferred reaction is an acid/base neutralization. After the colorant is converted to a migrating colorant, it will migrate through the colorant layer 6, the opaque layer 5 and into the enhancement layer 4 and be seen by the end user as a change in color. An example of a time switch time indicator according to the invention includes the following for the front part 1: transparent substrate 3 comprising a transparent polymeric film; enhancement layer 4 comprising a transparent adhesive; opaque layer 5 including a colored adhesive; colorant layer 6 including an ionomer dye in a polymeric matrix; neutralizing layer 7 including an acid in an adhesive; and timing layer 8 including an adhesive. The back part 2 includes: reactant layer 9 including a migrating reactant with a basic pH in an adhesive; and a base substrate 10 comprising paper or polymer film, which may have an adhesive (and optional associated removable release liner) on the bottom side for adhering to objects. A preferred example of a time switch time indicator (approximately 30-60 days to initial readability) includes the following for front part 1: transparent substrate 3 comprising clear PET (polyester) film; enhancement layer 4 comprising a clear layer including an adhesive commercially available as H&N 213 pressure sensitive adhesive—1 mil thick dry; white opaque layer 5 including commercially available Morton 1106VTiO2 in H&N 213 pressure sensitive adhesive (59.7%)—1 mil thick dry; colorant layer 6 including an ionomer dye, propylene glycol and a matrix of a pressure sensitive adhesive commercially available as Duro Tak 80-1100 from National Starch and Chemical Company, Bridgewater N.J., USA—1 mil dry; neutralizing layer 7 including para-toluene sulfonic acid, propylene glycol and Duro Tak 80-1100 pressure sensitive adhesive—1 mil dry; and timing layer 8 including propylene glycol and Duro Tak 80-1100 pressure sensitive adhesive—1 mil dry. The back part 2 includes: reactant layer 9 including a 2-amino-2-ethyl-1,3-propanediol (AEDP) (base) migrating reactant in Duro Tak 80-1100 pressure sensitive adhesive—1 mil dry; and a base substrate 10 comprising paper or polymer film. Various colorants may be used in the time indicator of the invention. The term colorant, used here, has a broad meaning in that it is a substance that has color or that can combine with another component and develop a new color. The colorant can be: hydrophilic or hydrophobic dyes, pigments, leuco dyes, dye intermediates, pH indicators, reactive dyes or any color formers. There are many ways that color can be formed after reacting with a reactant. These systems involve the migration of a component through the opaque layer. After migration of the component, a second component or components could react, interact, or combine to form a color change. Many different color change mechanisms can be used and are known throughout the art. Examples of the color changing mechanisms are: pH indicators, oxidation or reduction of a colorant, substitution reactions, elimination reactions, acid/base reactions, metal ion complexation, photosensitive reaction, decomposition reactions, or any other reaction and interaction known in the art. These mechanisms can involve the use of many different materials and colorants such as: reactive dyes, dye intermediates, leuco dyes, and other commercially available dyes. One way that the color can appear in the time indicator of the invention is with the use of the opaque layer 5 that initially conceals the colorant in the colorant layer 6. After the colorant is converted from the non-migratory form to the migratory form, the migratory form of the colorant can migrate into the opaque layer 5 and enhancement layer 4, revealing the color. In order to see the color, the opaque layer 5 should have a color different from the color of the colorant when in the opaque layer 5 or when at the surface of the opaque layer 5. One preferred non-migrating form of the colorant is an ionomer prepared from a dye called Disperse Orange 3. This type of colorant is referred to as an ionomer dye. The dye in this form does not migrate in the preferred medium of the colorant layer 6. The synthesis of this colorant in an ionamine form and similar others is as follows: Ionamine, Major Product ref. Journal of the Society of Dyers and Colourists, 39,11-16 (1923) Green and Saunders, “The Ionamines: A New Class of Dyestuffs for Acetate Silk” Anhydro dimer ref. Chemische Berichte, 39, 2814-2823 (1906) Bucherer and Schwalbe, “Ueber Aldehyde-Bisulfite und Hydrosulfite” Rearrangement product ref. Journal of Organic Chemistry, 24,1943-1948 (1959) Neelakatan and Hartung “alpha-Aminoalkanesulfonic Acids” This ionamine colorant, after being converted with a base (such as AEDP) yields a dye that migrates in the preferred medium of the colorant layer 6. Certain migratory dyes may be one color under a neutral environment, and when the dye migrates to the opaque layer 5 and the enhancement layer 4 and these layers are acidic in nature, the color will change toward a different color. The opaque layer 5 and the enhancement layer 4 can also be neutral in pH such that the final color seen is the original color of the migratory dye. Different colors can be produced if the base (chromophore) of the ionomer dye is changed. There are many other dyes that can be produced into ionomer dyes by the reaction schemes listed above. The preferred dye color is orange but there are several other dyes known in the art that can be used as the colorant in the colorant layer 6. Examples of red dyes that can be used are: Disperse Red 60, Disperse Red 4, Disperse Red 11, Disperse Red 15, Disperse Red 91, Solvent Red 5, and Disperse Violet 17. Various neutralizing agents (coreactants) can be used in the neutralizing layer 7. In particular, the neutralizing agent contains any coreactant that reacts with the migrating reactant. In one form, the neutralizing agent is of opposite pH to the migrating reactant. The coreactant in the neutralizing layer 7 prevents the migrating reactant from entering the colorant layer 6 and reacting with the colorant until the coreactant is depleted. The reaction can be a typical acid/base reaction, where the migrating reactant is a base and the coreactant is an acid, or the migrating reactant is an acid and the coreactant is a base. The reaction of an acid with a base yields a salt usually of a neutral pH. After all of the coreactant is reacted, the migrating reactant can react with the non-migratory ionomer dye in the colorant layer 6. For example, one suitable reaction is an acid/base reaction where the migrating reactant is a base and the neutralizing agent is an acid. Another type of reaction that can occur that is similar in nature and can occur in the neutralizing layer 7 is an oxidation/reduction reaction. In this case, the migrating reactant can be a reduced species and the neutralizing agent can be the oxidizing agent (or vice versa). When the two species interact, the reduced species becomes oxidized until the entire oxidizing agent is depleted. The migrating reactant can then migrate to the colorant layer 6 and interact with the non-migratory form of the colorant. The timing layer 8 can be a separate layer or can be combined with the neutralizing layer 7 depending on the preferred timing of the time indicator application. It can include a pressure sensitive adhesive, hydrogel, plasticized polymer resin such as an acrylic, urethane, styrene, polyester or any other similar material. It may contain plasticizers that lower the Tg of the resin and allow the reactant to migrate. The timing layer 8 must allow the migrating reactant to diffuse through itself. The thickness, selection of migrating reactant and timing layer composition will be the main control of the timing for the migration of the reactant. The timing control for the time indicator is based on the diffusion of the reactant in the timing layer 8 and the neutralizing layer 7, the rate of neutralization in the neutralizing layer 7, and the time required to deplete the neutralizing agent in the neutralizing layer 7 based on the amount of materials, thickness and composition. The color changing process is completely separate. It is based on the diffusion of the migrating reactant to the non-migratory dye in the colorant layer 6, the rate of the non-migratory to migratory conversion of the dye, and the diffusion of the migratory dye in the colorant layer 6 and the opaque layer 5. The activation process is the third process. Activation occurs when the end user marries the front part 1 and the back part 2 together. The goal is to have a long timing process yet have a short color changing process. The result is a clear understanding of the expiration point. EXAMPLE It has been demonstrated that a long term time indicator would be possible using the transformation of a non-migrating dye to a migrating dye brought about by migration of an amine. Fast migrating Disperse Orange 3 was chemically modified as follows to a non-migratory dye. In a two neck round bottom flask (300 ml.) equipped with magnetic stir bar, reflux condenser, thermometer and a stirrer/heating mantle, were mixed equimolar amounts (0.02 to 0.05 moles) of Disperse Orange 3 dye (available from Aldrich, 95% dye) and formaldehyde/sodium bisulfite 1:1 adduct (available from Aldrich) in 200 ml. of 50% aqueous alcohol (distilled water and completely denatured alcohol (ethanol/methanol {100 parts}, 2-propanol {10 parts}, methyl isobutyl ketone {1 part}). The mixture was stirred and heated to reflux for approximately six hours, then left to cool to room temperature overnight. The copious reddish brown precipitate was filtered using a Buchner funnel and vacuum sidearm flask. The crude yield was greater than 100% (based on the weight of Disperse Orange 3 charged) after air drying overnight. The dried, crude, solid reaction product was dried for several hours on filter paper in a 120° C. oven to remove residual solvents. In direct contact with triethanolamine, the color of the reaction product changed back to orange, with subsequent migration and development of color through opaque color change layers. Although the present invention has been described in detail with reference to certain embodiments, one skilled in the art will appreciate that the present invention can be practiced by other than the described embodiments, which have been presented for purposes of illustration and not of limitation. Therefore, the scope of the appended claims should not be limited to the description of the embodiments contained herein. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention This invention relates to a time indicator and, in particular, to a long term time indicator which provides a rapid and clear indication of expiration. 2. Description of the Related Art Numerous devices are known which provide, after activation, a visual indication of the passage of a predetermined amount of time. Such a time indicator is useful, for example, as a security badge, as an indicator of the length of time a perishable item has been on the wholesaler's or retailer's shelf and for numerous other uses. Some known time-indicating devices involve the migration of a colorant, dye or other material through a media. Many of these known time indicators, which are generally short term time indicators, are based on the migration of ink from one substrate through another substrate, i.e., in a path perpendicular to the surface of the substrate. After the ink diffuses for a time period through the substrate(s), it is viewed on a display surface to thereby indicate that the predetermined time has elapsed. Examples of this diffusion technology can be found in: U.S. Pat. No. 4,212,153 which describes a time indicator where a dye migrates to the surface of an indicator badge; U.S. Pat. Nos. 5,446,705 and 4,903,254 which describe the use of an ink dissolver layer in a time indicator; U.S. Pat. No. 5,058,088 which describes the concept of varying ink dot size and spacing to change the time indication period; U.S. Pat. No. 5,602,804 which describes a time indicator with control of lateral migration; U.S. Pat. Nos. 5,633,835 and 5,822,280 which describe the use of an organic liquid to dissolve a barrier layer and allow for dye migration; U.S. Pat. No. 6,295,252 which describes the use of an accelerator in an adhesive layer; U.S. Pat. No. 6,452,873 which discloses the enablement of dye migration by use of a plasticizer, U.S. Pat. No. 6,514,462 which describes the use of rubber polymers as the diffusion layer in a time-temperature indicator; and U.S. Patent Application Publication No. 2003/0053377 which describes the migration of an amorphous material into a porous matrix when the materials are brought together. Technologies based on dye diffusion are typically useful for short time intervals such as days or weeks. They are usually not useful for longer time intervals such as months because the color change occurs by gradual dye diffusion which begins the instant the activating adhesive cover is applied over these printed dyes. The time indicator may stay pure white for about a month and then start to gradually change color. During the time interval of gradual color change, the time indicator is in a “gray area” between absolutely YES and absolutely NO. This lack of a sharp transition time is a problem with simple dye diffusion systems. Other indicators in the prior art rely primarily upon chemical reactions to cause a visually perceptible change over a desired time period rather than merely the migration of fluids or compounds. U.S. Pat. No. 5,045,283 lists various color change reactions that are suitable for time indicator devices. In one example, U.S. Pat. No. 5,045,283 describes the use of acid or base reactant depletion before trigger of an indicator or to control diffusion. U.S. Pat. Nos. 5,085,802 and 5,182,212 also describe the concept of acid or base reactant depletion before trigger of an indicator. U.S. Pat. No. 6,254,969 describes the similar concept of oxygen depletion before trigger of an indicator. U.S. Pat. No. 6,544,925 discloses the use of co-reactants for color formation in a time-temperature indicator system. The aforedescribed devices are often complicated to adjust for a selected period of time. Adjustments often involve experimentation with many types of chemicals, inks, solvents, etc. to prepare a device which can operate under the conditions expected. Most of the prior art devices gradually change color over a period of time and involve, at best, a guess on how much time has elapsed. When this is combined with the possible variations in temperature, humidity, etc. that may exist in the environment of the time indicator, the viewer may have very little confidence that he is close to the expiration time of the device. Therefore, there remains a need for a long term time indicator wherein the dye does not begin to appear until the end or near the end of the time interval. Such a time indicator would remain unchanged (white or clear) until near the end of the time interval, and then the color would rapidly or, ideally, instantaneously appear. In essence, what is desirable is a time switch (a color-appearing step-function from white to dark), which stays white until the end of the time interval and then produces a step-function, meaning an instantaneous or rapid color change to clearly show that the time interval has ended. The time indicator would solve the problems with longer term indicators that suffer from an extended “gray time” where there is a slow change in the indication color. The time indicator would allow for a reduced “gray time” for a longer term indicator. | <SOH> SUMMARY OF THE INVENTION <EOH>The foregoing needs are met by a time indicator according to the invention. The time indicator rapidly changes color after a specified time. The time indicator system includes: a back part having a base substrate and a migrating reactant in or on the base substrate; and a front part having a timing layer, a neutralizing layer, a colorant layer, an opaque layer, a transparent adhesive enhancement layer, and a transparent front substrate. When the time indicator is activated by placing the timing layer of the front part and the reactant of the back part in contact, the reactant begins to migrate through the timing layer and to the neutralizing layer at a known rate. In one form, the neutralizing layer contains a counter pH agent that neutralizes the reactant. The timing layer is optional and may be needed for controlling the migration rate of the reactant and to extend or vary the timing as needed by the application. There is an excess of reactant compared to the neutralizing agent. The reactant migrates to the neutralizing layer and the acid or base is neutralized by the neutralizing agent. After the neutralizing agent is depleted, the reactant migrates to the colorant layer. The colorant layer has a colorant in a matrix. The colorant has a non-migratory form in which the colorant does not migrate in the matrix and a migratory form in which the colorant migrates in the matrix. The reactant combines with the non-migratory form of the colorant and converts the colorant to its migrating form. After conversion, the colorant migrates through the colorant layer and the opaque layer and can be seen by the user in the transparent front substrate. The time indicator according to the invention rapidly changes from a secure to an unsecure state (i.e., a color change is visible) after a well-defined delay time. In order to accomplish this, the timing control (induction time or delay period) and color change mechanisms (the rate of switching to an “alarm” state) are independently controlled. Previous devices used the timing control process and the color changing process to be the same. This invention separates the timing process and the color changing process. The time indicator is a three-step process. First is the activation process, followed by the timing process and then the color changing process. The activation process is a separate process, which is started by the end user, activated by allowing the front and back parts of the time indicator to come together. Indicators in which the timing process and the color changing process are combined have indications that are not very clear to the user, that is, a gradual color appearance. Very problematic are prior indicators of long periods wherein the timing process is as long as the color change process, making it difficult to distinguish a clear endpoint. Prior devices where a visual message becomes either visible or obscured are based on diffusion of a dye or an activator, which controls both the timing control process and the color changing process. The present invention overcomes these difficulties. The mechanism for the color change is separate from the mechanism to impart a time delay period so that the colorant remains immobilized until contacted by the reactant, which then allows the colorant to migrate very rapidly through the opaque layer and be seen by the end user. It is therefore an advantage of the present invention to provide a long term time indicator wherein the dye does not begin to appear until the end or near the end of the time interval. It is another advantage of the present invention to provide a time indicator that remains unchanged (white or clear) until near the end of the time interval, and then the color rapidly or instantaneously appears. It is yet another advantage of the present invention to provide a time indicator that acts as a time switch with a color-appearing step-function from white to dark to clearly show that a time interval has ended. It is still another advantage of the present invention to provide a time indicator that utilizes separate timing control and color change mechanisms to eliminate the problems associated with gradual color change in longer term time indicating devices. These and other features, aspects, and advantages of the present invention will become better understood upon consideration of the following detailed description, drawings, and appended claims. | 20040225 | 20061121 | 20050825 | 79334.0 | 0 | GOODWIN, JEANNE M | LONG TERM RAPID COLOR CHANGING TIME INDICATOR | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,786,569 | ACCEPTED | Method and apparatus for receiving a signal | The present invention provides a method for a flexible multimode operation of spread spectrum receivers, e.g., global navigation satellite system (GNSS) receivers, using a shared circuitry hardware configuration of the receiver for processing of different types of code division multiple access (CDMA) signals. According to said method the receiver utilizes shared channel circuitry to receive signals of different CDMA types providing a flexible multimode operation. The present invention provides a way to select the received signal type for each channel by replacing the dedicated channels with multimode channels suitable to multiple types of receiver signals. The multimode receiver is more flexible to operate in varying reception conditions. By utilizing shared channel circuitry the hardware size is kept small. | 1. A multimode spread spectrum receiver with a shared circuitry operation, capable of receiving at least two types of code division multiple access (CDMA) signals, comprising: an antenna, responsive to a radio frequency signal containing said at least two types of code division multiple access (CDMA) signals, for providing a radio frequency electrical signal; a preprocessor, responsive to the radio frequency electrical signal, for providing a digital signal; and at least one multimode receiving channel block, responsive to the digital signal and selecting, based on a predetermined selection criteria, one of at least two types of coding corresponding to one of said at least two types code division multiple access (CDMA) signals and utilizing said coding for further processing of said digital signal by said at least one multimode receiving block using said shared circuitry operation. 2. The multimode receiver of claim 1, wherein the digital signal is a digital intermediate frequency signal, wherein said selection is performed by the at least one multimode receiving channel block in response to a mode selection signal or to a mode-generating selection signal and wherein said at least one multimode receiving channel block generates, based on said selection, and provides internally one of the at least two code signals to said at least one multimode receiving channel block for implementing said further processing. 3. The multimode receiver of claim 2, wherein the at least one multimode receiving channel block is further responsive to a code control signal and providing a code and carrier measurement signal. 4. The multimode receiver of claim 3, further comprising: a receiver processing block, responsive to the code and carrier measurement signal, for providing the code control signal, a frequency control signal, and the mode selection signal or the mode-generating selection signal. 5. The multimode receiver of claim 4, further comprising: a residual carrier removing block, responsive to the digital intermediate frequency signal, for providing a data intermediate signal; and an integration and dumping block responsive to the data intermediate signal, to said one of the at least two code signals, for providing P dump signals to the receiver processing block, wherein P is an integer of at least a value of one. 6. The multimode receiver of claim 4, wherein the at least one multimode receiving channel block comprises: a code numerically controlled oscillator block, responsive to the code control signal, for providing a numerically controlled oscillator clock signal; a first code generator, responsive to the numerically controlled oscillator clock signal, for providing a first one of the at least two code signals for a corresponding first one of the at least two types of the code division multiple access receiver processing; a second code generator responsive to the numerically controlled oscillator clock signal, for providing a second one of the at least two code signals for a corresponding second one of the at least two types of the code division multiple access receiver processing; and a code selector, responsive to the mode selection signal, to said first one of the at least two code signals and to said second one of the at least two code signals, for providing said first one of the at least two code signals or said second one of the at least two code signals, selected by the code selector based on the mode selection signal, for further processing by the at least one multimode receiving channel block using said shared circuitry operation. 7. The multimode receiver of claim 6, wherein the first code generator, the second code generator or both code generators contain binary offset carrier capabilities. 8. The multimode receiver of claim 6, wherein the first one of the at least two code signals is for global positioning system receiver processing and the second one of the at least two code signals is for Galileo receiver processing. 9. The multimode receiver of claim 2, wherein the at least one multimode receiving channel block comprises: a code numerically controlled oscillator block responsive to the code control signal, for providing a numerically controlled oscillator clock signal; and a universal code generator, responsive to the numerically controlled oscillator clock signal and to the mode-generating selection signal, for generating and providing, based on the mode-generating selection signal, a first one of the at least two code signals for a corresponding first one of the at least two types of the code division multiple access receiver processing or a second one of the at least two code signals for a corresponding second one of the at least two types of the code division multiple access receiver processing for further processing by the at least one multimode receiving channel block using said shared circuitry operation. 10. The multimode receiver of claim 9, wherein the universal code generator contains binary offset carrier capabilities. 11. The multimode spread spectrum receiver of claim 1, wherein said receiver is a multimode global navigation satellite system receiver. 12. The multimode receiver of claim 11, wherein a first one of the at least two code signals is for global positioning system receiver processing and a second one of the at least two code signals is for Galileo receiver processing. 13. A method for a shared circuitry operation of a multimode spread spectrum receiver, capable of receiving at least two types of code division multiple access signals, comprising: receiving the radio frequency signal containing said at least two types of code division multiple access signals by an antenna of the multimode spread spectrum receiver and converting said radio frequency signal to a radio frequency electrical signal; converting the radio frequency electrical signal to a digital signal by a preprocessor of the multimode spread spectrum receiver and providing said digital signal to the at least one multimode receiving channel block; and selecting by at least one multimode receiving channel block, based on a predetermined selection criteria, one of at least two types of coding corresponding to one of said at least two types code division multiple access signals and utilizing said coding for further processing of said digital signal by said at least one multimode receiving block using said shared circuitry operation. 14. The method of claim 13, wherein the digital signal is a digital intermediate frequency signal, wherein said selection is performed by the at least one multimode receiving channel block in response to a mode selection signal or to a mode-generating selection signal and wherein said at least one multimode receiving channel block generates, based on said selection, and provides internally one of the at least two code signals to said at least one multimode receiving channel block for implementing said further processing. 15. The method of claim 14, wherein said selection by at least one multimode receiving block, based on a predetermined selection criteria, of one of at least two types of coding comprises: generating a first one of the at least two code signals for a corresponding first one of the at least two types of the code division multiple access receiver processing by a first code generator and generating a second one of the at least two code signals for a corresponding second one of the at least two types of the code division multiple access receiver processing by a second code generator and providing said first one of the at least two code signals and said second one of the at least two code signals to a code selector of the at least one multimode receiving channel block, wherein said first one of the at least two code signals and said second one of the at least two code signals are parts of said at least one multimode receiving channel block; selecting said first one of the at least two code signals or said second one of the at least two code signals by the code selector; and providing the selected said first one of the at least two code signals or said second one of the at least two code signals for further processing by the at least one multimode receiving channel block using said shared circuitry operation. 16. The method of claim 15, wherein said selecting of said first one of the at least two code signals or said second one of the at least two code signals by the code selector is based on the mode selection signal provided to the code selector by a receiver processing block. 17. The method of claim 15, wherein before generating the first one of the at least two code signals and the second one of the at least two code signals, the method further comprises: providing a code control signal to a code numerically controlled oscillator block of the at least one multimode receiving channel block; and generating, in response to said code control signal, a numerically controlled oscillator clock signal by the code numerically controlled oscillator block and providing the numerically controlled oscillator clock signal to the first code generator and to the second code generator. 18. The method of claim 17, wherein said code control signal is provided to the code numerically controlled oscillator block by a receiver processing block. 19. The method of claim 15, wherein the further processing is performed by an integrating and dumping block of the at least one multimode receiving channel block. 20. The method of claim 19, wherein before providing the code control signal, the method further comprises: generating a data intermediate signal by removing a residual carrier frequency from the digital intermediate frequency signal by a residual carrier removing block of the at least one multimode receiving channel block and providing said data intermediate signal to the integrating and dumping block for further processing. 21. The method of claim 14, wherein said selection by at least one multimode receiving block, based on a predetermined selection criteria, of one of at least two types of coding comprises: generating a first one of the at least two code signals for a corresponding first one of the at least two types of the code division multiple access receiver processing or a second one of the at least two code signals for a corresponding second one of the at least two types of the code division multiple access receiver processing by a universal code generator of the at least one multimode receiving channel block; and providing the first one of the at least two code signals or the second one of the at least two code signals by the universal code generator for further processing by the at least one multimode receiving channel block using said shared circuitry operation. 22. The method of claim 21, wherein generating the first one of the at least two code signals or the second one of the at least two code signals by the universal code generator is based on the mode-generating selection signal provided to the universal code generator by a receiver processing block. 23. The method of claim 21, wherein before generating the first one of the at least two code signals and the second one of the at least two code signals, the method further comprises: providing a code control signal to a code numerically controlled oscillator block of the at least one multimode receiving channel block; and generating, in response to said code control signal, a numerically controlled oscillator clock signal by the code numerically controlled oscillator block and providing the numerically controlled oscillator clock signal to the universal code generator. 24. The method of claim 21, wherein said code control signal is provided to the code numerically controlled oscillator block by a receiver processing block. 25. The method of claim 21, wherein the further processing is performed by an integrating and dumping block of the at least one multimode receiving channel block. 26. The method of claim 25, wherein before providing the code control signal, the method further comprises: generating a data intermediate signal by removing a residual carrier frequency from the digital intermediate frequency signal by a residual carrier removing block of the at least one multimode receiving channel block and providing said data intermediate signal to the integrating and dumping block for further processing. 27. The method of claim 13, wherein said receiver is a multimode global navigation satellite system receiver. 28. The method of claim 27, wherein a first one of the at least two code signals is for global positioning system receiver processing and a second one of the at least two code signals is for Galileo receiver processing. 29. A computer program product comprising: a computer readable storage structure embodying computer program code thereon for execution by a computer processor with said computer program code, characterized in that it includes instructions for performing the steps of the method of claim 13 indicated as being performed by the multimode spread spectrum receiver, or by the multimode receiving channel block of said spread spectrum receiver, or by a terminal containing said spread spectrum receiver. 30. A system for communicating at least two types of code division multiple access signals received by a multimode spread spectrum receiver with a shared circuitry operation, comprising: at least one satellite, for providing said at least two types of code division multiple access signals, or at least two satellites each providing one of said at least two types of the code division multiple access signals; at least one base station, for providing said at least two types of the code division multiple access signals used for mobile communications; and a terminal, responsive to said at least two different types of the code division multiple access signals, wherein said terminal containing said multimode spread spectrum receiver capable of receiving said at least two types of code division multiple access signals using at least one multimode receiving channel block, responsive to the digital signal indicative of one of said at least two different types of the code division multiple access signals and selecting, based on a predetermined selection criteria, one of at least two types of coding corresponding to said one of the at least two types code division multiple access signals and utilizing said coding for further processing of said digital signal by said at least one multimode receiving block using said shared circuitry operation. 31. A multimode receiving module with a shared circuitry operation capable of receiving at least two types of code division multiple access signals and contained in a multimode spread spectrum receiver, comprising: at least one multimode receiving channel block, responsive to the digital signal containing one of said at least two types of the code division multiple access signals and selecting, based on a predetermined selection criteria, one of at least two types of coding corresponding to said one of at least two types code division multiple access signals and utilizing said coding for further processing of said digital signal by said at least one multimode receiving block using said shared circuitry operation, wherein said multimode receiving module is removable from said multimode spread spectrum receiver. | FIELD OF THE INVENTION This invention generally relates to a spread spectrum receiver, and more specifically to a multimode operation of the receiver using a shared circuitry hardware configuration. BACKGROUND OF THE INVENTION 1. Field of Technology and Problem Formulation It is desirable to have a spread spectrum receiver capable of receiving at least two (or more) types of code division multiple access (CDMA) signals. For example, dual mode GPS (global positioning system)/Galileo receivers must be able to receive both GPS and Galileo signals simultaneously. An obvious approach used so far is combining a GPS receiver and a Galileo receiver, so that some hardware receiving channels are dedicated to receive a GPS signal, and some channels are dedicated to receive a Galileo signal. For example, a 16-channel receiver can have 8 GPS channels and 8 Galileo channels. However, in some situations it might be desirable to receive e.g., 12 Galileo signals and 4 GPS signals due to DOP (dilution of precision) or signal blocking conditions. With the 8 GPS channels plus 8 Galileo channels hardware this is impossible. Therefore, a more flexible multimode operation of the spread spectrum receiver and hardware architecture is desirable. 2. Prior Art An example of a prior art solution is demonstrated in FIGS. 1 and 2. FIG. 1 is a block diagram representing one example of a typical operation of a global navigation satellite system receiver 10 with dedicated M GPS receiving channel blocks 16-1, 16-2, . . . , 16-M and dedicated N Galileo receiving channel blocks 18-1, 18-2, . . . , 18-N, wherein M is an integer of at least a value of one and N is an integer of at least a value of one. Typical operation includes receiving the radio frequency signal and converting said radio frequency signal to a radio frequency electrical signal 11a by an antenna 11 followed by converting said radio frequency electrical signal 11a to a digital intermediate frequency (IF) signal 14 by a preprocessor 12 and providing said digital IF signal 14 to the dedicated M GPS receiving channel blocks 16-1, 16-2, . . . , 16-M and to the dedicated N Galileo receiving channel blocks 18-1, 18-2, . . . , 18-N, which normally exchange information with the receiver processing block 22 during their operation. FIG. 2 is a block diagram representing an example of one of the dedicated GPS receiving channel blocks 16-1, 16-2, . . . , 16-M or the dedicated Galileo receiving channel blocks 18-1, 18-2, . . . , 18-N shown in FIG. 1. As seen from FIG. 2, the only difference between the GPS receiving channel blocks 16-1, 16-2, . . . , 16-M and the Galileo receiving channel blocks 18-1, 18-2, . . . , 18-N is in a code generating block 24 which uses a dedicated GPS code generator 28-1 for generating a GPS code signal 42 in case of the GPS receiving channel blocks 16-1, 16-2, . . . , 16-M and a dedicated Galileo code generator 28-2 for generating a Galileo code signal 44 in case of the Galileo receiving channel blocks 18-1, 18-2, . . . , 18-N, respectively. All other components including an integrating and damping block 32 and a residual carrier removing block 25 as well as a frequency control signal 34, a code control signal 38, a data intermediate signal 36, a code and carrier measurement signal 37 and dump signals 46-1, 46-2, . . . , 46-P (P is an integer of at least a value of one) perform identical functions for both GPS and Galileo receiving channel blocks 16-1, 16-2, . . . , 16-M, 18-1, 18-2, . . . , 18-N. FIGS. 1 and 2 demonstrate only one example for implementing the global navigation satellite system receiver 10 per the prior art. It is noted that details incorporated in blocks 12 and 16-1, 16-2, . . . , 16-M, 18-1, 18-2, . . . , or 18-N are provided for reference only and represent only one example among many others for implementation of these blocks. SUMMARY OF THE INVENTION It is now invented a novel method for providing a multimode operation of a spread spectrum receiver, e.g., a global navigation satellite system (GNSS) receiver, using a shared circuitry hardware configuration of said receiver. According to a first aspect of the invention, a multimode spread spectrum receiver with a shared circuitry operation, capable of receiving at least two types of code division multiple access (CDMA) signals, comprises: an antenna, responsive to a radio frequency signal containing said at least two types of code division multiple access (CDMA) signals, for providing a radio frequency electrical signal; a preprocessor, responsive to the radio frequency electrical signal, for providing a digital signal; and at least one multimode receiving channel block, responsive to the digital signal and selecting, based on a predetermined selection criteria, one of at least two types of coding corresponding to one of said at least two types code division multiple access (CDMA) signals and utilizing said coding for further processing of said digital signal by said at least one multimode receiving block using said shared circuitry operation. According further to the first aspect of the invention, the digital signal may be a digital intermediate frequency signal, said selection may be performed by the at least one multimode receiving channel block in response to a mode selection signal or to a mode-generating selection signal and finally said at least one multimode receiving channel block may generate, based on said selection, and provide internally one of the at least two code signals to said at least one multimode receiving channel block for implementing said further processing. Further, the at least one multimode receiving channel block may be further responsive to a code control signal and providing a code and carrier measurement signal. Still further, the multimode receiver may further comprise a receiver processing block, responsive to the code and carrier measurement signal, for providing the code control signal, a frequency control signal, and the mode selection signal or the mode-generating selection signal. Yet still further, the multimode receiver may further comprise: a residual carrier removing block, responsive to the digital intermediate frequency signal, for providing a data intermediate signal; and an integration and dumping block responsive to the data intermediate signal, to said one of the at least two code signals, for providing P dump signals to the receiver processing block, wherein P is an integer of at least a value of one. Further according to the first aspect of the invention, the at least one multimode receiving channel block may comprise: a code numerically controlled oscillator block, responsive to the code control signal, for providing a numerically controlled oscillator clock signal; a first code generator, responsive to the numerically controlled oscillator clock signal, for providing a first one of the at least two code signals for a corresponding first one of the at least two types of the code division multiple access receiver processing; a second code generator responsive to the numerically controlled oscillator clock signal, for providing a second one of the at least two code signals for a corresponding second one of the at least two types of the code division multiple access receiver processing; and a code selector, responsive to the mode selection signal, to said first one of the at least two code signals and to said second one of the at least two code signals, for providing said first one of the at least two code signals or said second one of the at least two code signals, selected by the code selector based on the mode selection signal, for further processing by the at least one multimode receiving channel block using said shared circuitry operation. Further, the first code generator, the second code generator or both code generators may contain binary offset carrier capabilities. Yet still further, the first one of the at least two code signals may be for global positioning system receiver processing and the second one of the at least two code signals may be for Galileo receiver processing. Still further according to the first aspect of the invention, the at least one multimode receiving channel block may comprise: a code numerically controlled oscillator block responsive to the code control signal, for providing a numerically controlled oscillator clock signal; and a universal code generator, responsive to the numerically controlled oscillator clock signal and to the mode-generating selection signal, for generating and providing, based on the mode-generating selection signal, a first one of the at least two code signals for a corresponding first one of the at least two types of the code division multiple access receiver processing or a second one of the at least two code signals for a corresponding second one of the at least two types of the code division multiple access receiver processing for further processing by the at least one multimode receiving channel block using said shared circuitry operation. Further still, the universal code generator may contain binary offset carrier capabilities. According further to the first aspect of the invention, the receiver may be a multimode global navigation satellite system receiver. Yet still further, a first one of the at least two code signals may be for global positioning system receiver processing and a second one of the at least two code signals may be for Galileo receiver processing. According to a second aspect of the invention, a method for a shared circuitry operation of a multimode spread spectrum receiver, capable of receiving at least two types of code division multiple access signals, comprises:receiving the radio frequency signal containing said at least two types of code division multiple access signals by an antenna of the multimode spread spectrum receiver and converting said radio frequency signal to a radio frequency electrical signal; converting the radio frequency electrical signal to a digital signal by a preprocessor of the multimode spread spectrum receiver and providing said digital signal to the at least one multimode receiving channel block; and selecting by at least one multimode receiving channel block, based on a predetermined selection criteria, one of at least two types of coding corresponding to one of said at least two types code division multiple access signals and utilizing said coding for further processing of said digital signal by said at least one multimode receiving block using said shared circuitry operation. Further, the digital signal may be a digital intermediate frequency signal, said selection may be performed by the at least one multimode receiving channel block in response to a mode selection signal or to a mode-generating selection signal and finally said at least one multimode receiving channel block may generate, based on said selection, and provide internally one of the at least two code signals to said at least one multimode receiving channel block for implementing said further processing. According further to the second aspect of the invention, the selection by at least one multimode receiving block, based on a predetermined selection criteria, of one of at least two types of coding may comprise: generating a first one of the at least two code signals for a corresponding first one of the at least two types of the code division multiple access receiver processing by a first code generator and generating a second one of the at least two code signals for a corresponding second one of the at least two types of the code division multiple access receiver processing by a second code generator and providing said first one of the at least two code signals and said second one of the at least two code signals to a code selector of the at least one multimode receiving channel block, wherein said first one of the at least two code signals and said second one of the at least two code signals are parts of said at least one multimode receiving channel block; selecting said first one of the at least two code signals or said second one of the at least two code signals by the code selector; and providing the selected said first one of the at least two code signals or said second one of the at least two code signals for further processing by the at least one multimode receiving channel block using said shared circuitry operation. Further, said selecting of said first one of the at least two code signals or said second one of the at least two code signals by the code selector may be based on the mode selection signal provided to the code selector by a receiver processing block. Further according to the second aspect of the invention, before generating the first one of the at least two code signals and the second one of the at least two code signals, the method may further comprise: providing a code control signal to a code numerically controlled oscillator block of the at least one multimode receiving channel block; and generating, in response to said code control signal, a numerically controlled oscillator clock signal by the code numerically controlled oscillator block and providing the numerically controlled oscillator clock signal to the first code generator and to the second code generator. Further, said code control signal may be provided to the code numerically controlled oscillator block by a receiver processing block. Still further, Still further according to the second aspect of the invention, the further processing may be performed by an integrating and dumping block of the at least one multimode receiving channel block. Further, before providing the code control signal, the method may further comprise: generating a data intermediate signal by removing a residual carrier frequency from the digital intermediate frequency signal by a residual carrier removing block of the at least one multimode receiving channel block and providing said data intermediate signal to the integrating and dumping block for further processing. According further to the second aspect of the invention, the selection by at least one multimode receiving block, based on a predetermined selection criteria, of one of at least two types of coding may comprise: generating a first one of the at least two code signals for a corresponding first one of the at least two types of the code division multiple access receiver processing or a second one of the at least two code signals for a corresponding second one of the at least two types of the code division multiple access receiver processing by a universal code generator of the at least one multimode receiving channel block; and providing the first one of the at least two code signals or the second one of the at least two code signals by the universal code generator for further processing by the at least one multimode receiving channel block using said shared circuitry operation. Further, generating the first one of the at least two code signals or the second one of the at least two code signals by the universal code generator may be based on the mode-generating selection signal provided to the universal code generator by a receiver processing block. Still further, before generating the first one of the at least two code signals and the second one of the at least two code signals, the method may further comprise: providing a code control signal to a code numerically controlled oscillator block of the at least one multimode receiving channel block; and generating, in response to said code control signal, a numerically controlled oscillator clock signal by the code numerically controlled oscillator block and providing the numerically controlled oscillator clock signal to the universal code generator. Yet still further, said code control signal may be provided to the code numerically controlled oscillator block by a receiver processing block. According still further to the second aspect of the invention, the further processing may be performed by an integrating and dumping block of the at least one multimode receiving channel block. Further, before providing the code control signal, the method may further comprise: generating a data intermediate signal by removing a residual carrier frequency from the digital intermediate frequency signal by a residual carrier removing block of the at least one multimode receiving channel block and providing said data intermediate signal to the integrating and dumping block for further processing. According further still to the second aspect of the invention, said receiver may be a multimode global navigation satellite system receiver. Still further, a first one of the at least two code signals may be for global positioning system receiver processing and a second one of the at least two code signals may be for Galileo receiver processing. According to a third aspect of the invention, a computer program product comprises: a computer readable storage structure embodying computer program code thereon for execution by a computer processor with said computer program code characterized in that it includes instructions for performing the steps of the method of the second aspect indicated as being performed by the multimode spread spectrum receiver, or by the multimode receiving channel block of said spread spectrum receiver, or by a terminal containing said spread spectrum receiver. According to a fourth aspect of the invention, a system for communicating at least two types of code division multiple access signals received by a multimode spread spectrum receiver with a shared circuitry operation, comprises: at least one satellite, for providing said at least two types of code division multiple access signals, or at least two satellites each providing one of said at least two types of the code division multiple access signals; at least one base station, for providing said at least two types of the code division multiple access signals used for mobile communications; and a terminal, responsive to said at least two different types of the code division multiple access signals, wherein said terminal containing said multimode spread spectrum receiver capable of receiving said at least two types of code division multiple access signals using at least one multimode receiving channel block, responsive to the digital signal indicative of one of said at least two different types of the code division multiple access signals and selecting, based on a predetermined selection criteria, one of at least two types of coding corresponding to said one of the at least two types code division multiple access signals and utilizing said coding for further processing of said digital signal by said at least one multimode receiving block using said shared circuitry operation. According to a fifth aspect of the invention, a multimode receiving module with a shared circuitry operation capable of receiving at least two types of code division multiple access signals and contained in a multimode spread spectrum receiver, comprises: at least one multimode receiving channel block, responsive to the digital signal containing one of said at least two types of the code division multiple access signals and selecting, based on a predetermined selection criteria, one of at least two types of coding corresponding to said one of at least two types code division multiple access signals and utilizing said coding for further processing of said digital signal by said at least one multimode receiving block using said shared circuitry operation, wherein said multimode receiving module is removable from said multimode spread spectrum receiver. BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the nature and objects of the present invention, reference is made to the following detailed description taken in conjunction with the following drawings, in which: FIG. 1 is a block diagram representing an example of a global navigation satellite system receiver with dedicated GPS and Galileo receiving channel blocks, according to the prior art. FIG. 2 is a block diagram representing an example of a dedicated GPS receiving channel block or a Galileo receiving channel block, according to the prior art. FIG. 3 is a block diagram representing an example of a multimode global navigation satellite system receiver with a shared circuitry operation, capable of generating and providing GPS or Galileo code signals, according to the present invention. FIG. 4 is a block diagram representing an example of a multimode receiving channel block, a part of a multimode global navigation satellite system receiver, with a shared circuitry operation, capable of generating and providing a GPS code signal or a Galileo code signal, according to the present invention. FIG. 5 is a block diagram representing an alternative example for a code generating block of a multimode receiving channel block, according to the present invention. FIG. 6 shows an example of a flow chart for generating and providing a GPS code signal or a Galileo code signal by a multimode receiving channel block with a shared circuitry operation, according to the present invention. FIG. 7 shows an alternative example of a flow chart for generating and providing a GPS code signal or a Galileo code signal by a code generating block of a multimode receiving channel block, according to the present invention. FIG. 8 shows an example of a terminal with a spread spectrum multimode CDMA receiver using a shared circuitry hardware configuration of the receiver for multimode operation processing of different types of code division multiple access (CDMA) signals from satellites or a base station. DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for a flexible multimode operation of spread spectrum receivers, e.g., global navigation satellite system (GNSS) receivers using a shared circuitry hardware configuration of the receiver for processing of different types of code division multiple access (CDMA) signals. According to said method the receiver utilizes shared channel circuitry to receive signals from different satellite systems providing a flexible multimode operation. The present invention provides a way to select the received signal type (e.g., GPS or Galileo) for each channel. By replacing the dedicated GPS/Galileo channels with multimode channels suitable to both receiver signals or, in a general case, by replacing the dedicated channels with multimode channels suitable to multiple types (more than two) of receiver signals, the receiver is more flexible to operate in varying reception conditions. By utilizing shared channel circuitry the hardware size is kept small. FIG. 3 is a block diagram representing one example among others of a multimode global navigation satellite system receiver 10a with a shared circuitry operation, capable of generating and providing GPS or Galileo code signals, according to the present invention. The key difference between FIG. 3 and FIG. 1 describing the prior art is that the dedicated GPS receiving channel blocks 16-1, 16-2, . . . , 16-M and the Galileo receiving channel blocks 18-1, 18-2, . . . , 18-N of FIG. 1 are substituted by multimode receiving channel blocks 20-1, 20-2, . . . , 20-K (K is an integer of at least a value of one), each capable of both GPS and Galileo signal processing. FIG. 4 is a block diagram representing one example among many others of a multimode receiving channel block 20-1, 20-2, . . . , or 20-K with a shared circuitry operation, capable of generating and providing a GPS code signal 42 or a Galileo code signal 44, according to the present invention. Again, the key difference between FIG. 4 and FIG. 2 describing the prior art is that the multimode receiving channel block 20-1, 20-2, . . . , or 20-K has a modified code generation block 24a instead of the block 24. The code generation block 24a consists of a code numerically controlled oscillator (NCO) block 26, which generates a numerically controlled oscillator (NCO) clock signal 40 in response to the code control signal 38 from the receiver processing block 22 as in the prior art. But then said NCO clock signal 40 is provided to both a GPS code generator 28a and to a Galileo code generator 28b. The GPS code generator 28a and a Galileo code generator 28b generate a GPS code signal 42 and a Galileo code signal 44, respectively, and provide both signals 42 and 44 to a code selector 30. The code selector 30 selects the GPS code signal 42 or the Galileo code signal 44 based on a mode selection signal 31 provided to the code selector 30 by the receiver processing block 22. Finally, the selected GPS code signal 42 or the Galileo code signal 44 is provided to the integrating and dumping block 32 which performs further processing as in the prior art (see FIG. 2). FIG. 5 is a block diagram representing an alternative example among others for implementing of a code generating block 24b of a multimode receiving channel block 20-1, 20-2, . . . , or 20-K with a shared circuitry operation, capable of generating and providing the GPS code signal 42 or the Galileo code signal 44, according to the present invention. The difference between the block 24b and the block 24a of FIG. 4 is that a universal code generator 28c of the block 24b shown in FIG. 5 performs the functions performed by the blocks 28a, 28b and 30 of FIG. 4. In particular, the NCO clock signal 40 is provided by the code NCO block 26 only to the universal code generator 28c, which generates the GPS code signal 42 or the Galileo code signal 44 based on a mode-generating selection signal 33 provided to the universal code generator 28c by the receiver processing block 22. And finally, the generated GPS code signal 42 or the Galileo code signal 44 is provided to the integrating and dumping block 32 which performs further processing as in the prior art (see FIG. 2). FIG. 6 shows an example of a flow chart for generating and providing the GPS code signal 42 or the Galileo code signal 44 by the multimode receiving channel block 20-1, 20-2, . . . , or 20-K with the shared circuitry operation as shown in FIG. 4, according to the present invention. The flow chart of FIG. 6 represents only one possible scenario among others. In a method according to the present invention, in a first step 50, the radio frequency signal is received by the antenna 11 and converted to the radio frequency electrical signal 11a. In a next step 52, said radio frequency electrical signal 11a is converted to a digital intermediate frequency signal 24 by a preprocessor 12 and provided to the residual carrier removing (RCR) block 25 of the multimode receiving channel block 20-1, 20-2, . . . , or 20-K. In a next step 54, the RCR block 25 removes a residual carrier frequency from the digital IF signal 14 using the frequency control signal 34 provided to the RCR block 25 by the receiver processing block 22 thus generating the data intermediate signal 36 and providing said signal 36 to the integrating and dumping block 32 for further processing. In a next step 55, the code control signal 38 is provided to the code NCO block 26 by the receiver processing block 22. In a next step 56, the NCO block 26 generates the NCO clock signal 40 in response to the code control signal 38 from the receiver processing block 22 and provides said NCO clock signal 40 to both the GPS code generator 28a and to the Galileo code generator 28b. In a next step 58, the GPS code generator 28a and a Galileo code generator 28b generate the GPS code signal 42 and the Galileo code signal 44, respectively, and provide both signals 42 and 44 to the code selector 30. In a next step 60, the code selector 30 selects the GPS code signal 42 or the Galileo code signal 44 based on the mode selection signal 31 provided to the code selector 30 by the receiver processing block 22. In a next step 62, the selected GPS code signal 42 or the Galileo code signal 44 is provided to the integrating and dumping block 32 of the multimode receiving channel block 20-1, 20-2, . . . , or 20-K for further processing. Finally, in a next step 64, dump signals 46-1, 46-2, . . . , 46-P are generated, in response to the signals 42 or 44 and to the data intermediate signal 36, and provided to the receiver processing block 22. FIG. 7 shows an alternative example among many others of a flow chart for generating and providing the GPS code signal 42 or the Galileo code signal 44 by the multimode receiving channel block 20-1, 20-2, . . . , or 20-K with the shared circuitry operation as shown in FIG. 5, according to the present invention. First four steps 50 through 55 are the same as in FIG. 6 and are described above. In a next step 66, the NCO block 26 generates the NCO clock signal 40 in response to the code control signal 38 from the receiver processing block 22 and provides the NCO clock signal 40 to the universal code generator 28c. In a next step 68, the mode-generating selection signal 33 is provided to the universal code generator 28c by the receiver processing block 22. In a next step 70, the code generator 28c generates the GPS code signal 42 or the Galileo code signal 44 in response to the mode-generating selection signal 33. The last two steps 62 and 64 are the same as in FIG. 6 and are described above. There are many variations of the scenarios described above, according to the present invention. For example, the code generator blocks 28a, 28b and 28c can also include binary offset carrier (BOC) generation. Also, it is not necessary that all channels are multimode channels as presented in FIG. 3. It is also possible to have a mixture of dedicated channels and multimode channels. Although GPS and Galileo satellite navigation systems have been used as an example in the description, it is obvious that the present invention can be used equally well with other navigation systems or more generally to any communication system utilizing a multimode spread spectrum receiver. An example of such a system is shown in FIG. 8. A terminal (or a user equipment, UE) 72 is a communication device, such as a mobile device or a mobile phone, containing a multimode CDMA receiver 73 according to the present invention. The multimode CDMA receiver 73 can be, for instance, the multimode global navigation satellite system (GNSS) receiver 10a described in the examples of FIGS. 3 through 7. Moreover, said multimode CDMA receiver 73 contains a multimode receiving module 74 with the key innovation as described in the present invention. The block 74 can be built as a removable unit. The multimode receiving module 74 can be, for example, a combination of blocks 20-1, 20-2, . . . , and 20-K as presented in FIG. 3 for the multimode GNSS receiver 10a. FIG. 8 shows at least two satellites (e.g., GPS application typically requires 3 satellites) 76 sending two different types of CDMA signals, CDMA 1 and CDMA 2 satellite signals 80a and 80b, respectively, to the CDMA receiver 73. FIG. 8 also shows a base station 78, which communicates with the terminal 72 by sending, e.g., a mobile CDMA communication signal 82a to the multimode CDMA receiver 73 and receiving back the outgoing communication signal 82b from the terminal 72. Said signal 82a can be of various CDMA types and is processed by the multimode receiving module as described in the present invention. As explained above, the invention provides both a method and corresponding equipment consisting of various modules providing the functionality for performing the steps of the method. The modules may be implemented as hardware, or may be implemented as software or firmware for execution by a processor. In particular, in the case of firmware or software, the invention can be provided as a computer program product including a computer readable storage structure embodying computer program code, i.e. the software or firmware thereon for execution by a computer processor provided with the terminal 72, with the CDMA receiver 73 (e.g., multimode global navigation satellite system receiver 10a) or with the multimode receiving module 74 (e.g., multimode receiving channel blocks 20-1, 20-2, . . . and 20-K). | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of Technology and Problem Formulation It is desirable to have a spread spectrum receiver capable of receiving at least two (or more) types of code division multiple access (CDMA) signals. For example, dual mode GPS (global positioning system)/Galileo receivers must be able to receive both GPS and Galileo signals simultaneously. An obvious approach used so far is combining a GPS receiver and a Galileo receiver, so that some hardware receiving channels are dedicated to receive a GPS signal, and some channels are dedicated to receive a Galileo signal. For example, a 16-channel receiver can have 8 GPS channels and 8 Galileo channels. However, in some situations it might be desirable to receive e.g., 12 Galileo signals and 4 GPS signals due to DOP (dilution of precision) or signal blocking conditions. With the 8 GPS channels plus 8 Galileo channels hardware this is impossible. Therefore, a more flexible multimode operation of the spread spectrum receiver and hardware architecture is desirable. 2. Prior Art An example of a prior art solution is demonstrated in FIGS. 1 and 2 . FIG. 1 is a block diagram representing one example of a typical operation of a global navigation satellite system receiver 10 with dedicated M GPS receiving channel blocks 16 - 1 , 16 - 2 , . . . , 16 -M and dedicated N Galileo receiving channel blocks 18 - 1 , 18 - 2 , . . . , 18 -N, wherein M is an integer of at least a value of one and N is an integer of at least a value of one. Typical operation includes receiving the radio frequency signal and converting said radio frequency signal to a radio frequency electrical signal 11 a by an antenna 11 followed by converting said radio frequency electrical signal 11 a to a digital intermediate frequency (IF) signal 14 by a preprocessor 12 and providing said digital IF signal 14 to the dedicated M GPS receiving channel blocks 16 - 1 , 16 - 2 , . . . , 16 -M and to the dedicated N Galileo receiving channel blocks 18 - 1 , 18 - 2 , . . . , 18 -N, which normally exchange information with the receiver processing block 22 during their operation. FIG. 2 is a block diagram representing an example of one of the dedicated GPS receiving channel blocks 16 - 1 , 16 - 2 , . . . , 16 -M or the dedicated Galileo receiving channel blocks 18 - 1 , 18 - 2 , . . . , 18 -N shown in FIG. 1 . As seen from FIG. 2 , the only difference between the GPS receiving channel blocks 16 - 1 , 16 - 2 , . . . , 16 -M and the Galileo receiving channel blocks 18 - 1 , 18 - 2 , . . . , 18 -N is in a code generating block 24 which uses a dedicated GPS code generator 28 - 1 for generating a GPS code signal 42 in case of the GPS receiving channel blocks 16 - 1 , 16 - 2 , . . . , 16 -M and a dedicated Galileo code generator 28 - 2 for generating a Galileo code signal 44 in case of the Galileo receiving channel blocks 18 - 1 , 18 - 2 , . . . , 18 -N, respectively. All other components including an integrating and damping block 32 and a residual carrier removing block 25 as well as a frequency control signal 34 , a code control signal 38 , a data intermediate signal 36 , a code and carrier measurement signal 37 and dump signals 46 - 1 , 46 - 2 , . . . , 46 -P (P is an integer of at least a value of one) perform identical functions for both GPS and Galileo receiving channel blocks 16 - 1 , 16 - 2 , . . . , 16 -M, 18 - 1 , 18 - 2 , . . . , 18 -N. FIGS. 1 and 2 demonstrate only one example for implementing the global navigation satellite system receiver 10 per the prior art. It is noted that details incorporated in blocks 12 and 16 - 1 , 16 - 2 , . . . , 16 -M, 18 - 1 , 18 - 2 , . . . , or 18 -N are provided for reference only and represent only one example among many others for implementation of these blocks. | <SOH> SUMMARY OF THE INVENTION <EOH>It is now invented a novel method for providing a multimode operation of a spread spectrum receiver, e.g., a global navigation satellite system (GNSS) receiver, using a shared circuitry hardware configuration of said receiver. According to a first aspect of the invention, a multimode spread spectrum receiver with a shared circuitry operation, capable of receiving at least two types of code division multiple access (CDMA) signals, comprises: an antenna, responsive to a radio frequency signal containing said at least two types of code division multiple access (CDMA) signals, for providing a radio frequency electrical signal; a preprocessor, responsive to the radio frequency electrical signal, for providing a digital signal; and at least one multimode receiving channel block, responsive to the digital signal and selecting, based on a predetermined selection criteria, one of at least two types of coding corresponding to one of said at least two types code division multiple access (CDMA) signals and utilizing said coding for further processing of said digital signal by said at least one multimode receiving block using said shared circuitry operation. According further to the first aspect of the invention, the digital signal may be a digital intermediate frequency signal, said selection may be performed by the at least one multimode receiving channel block in response to a mode selection signal or to a mode-generating selection signal and finally said at least one multimode receiving channel block may generate, based on said selection, and provide internally one of the at least two code signals to said at least one multimode receiving channel block for implementing said further processing. Further, the at least one multimode receiving channel block may be further responsive to a code control signal and providing a code and carrier measurement signal. Still further, the multimode receiver may further comprise a receiver processing block, responsive to the code and carrier measurement signal, for providing the code control signal, a frequency control signal, and the mode selection signal or the mode-generating selection signal. Yet still further, the multimode receiver may further comprise: a residual carrier removing block, responsive to the digital intermediate frequency signal, for providing a data intermediate signal; and an integration and dumping block responsive to the data intermediate signal, to said one of the at least two code signals, for providing P dump signals to the receiver processing block, wherein P is an integer of at least a value of one. Further according to the first aspect of the invention, the at least one multimode receiving channel block may comprise: a code numerically controlled oscillator block, responsive to the code control signal, for providing a numerically controlled oscillator clock signal; a first code generator, responsive to the numerically controlled oscillator clock signal, for providing a first one of the at least two code signals for a corresponding first one of the at least two types of the code division multiple access receiver processing; a second code generator responsive to the numerically controlled oscillator clock signal, for providing a second one of the at least two code signals for a corresponding second one of the at least two types of the code division multiple access receiver processing; and a code selector, responsive to the mode selection signal, to said first one of the at least two code signals and to said second one of the at least two code signals, for providing said first one of the at least two code signals or said second one of the at least two code signals, selected by the code selector based on the mode selection signal, for further processing by the at least one multimode receiving channel block using said shared circuitry operation. Further, the first code generator, the second code generator or both code generators may contain binary offset carrier capabilities. Yet still further, the first one of the at least two code signals may be for global positioning system receiver processing and the second one of the at least two code signals may be for Galileo receiver processing. Still further according to the first aspect of the invention, the at least one multimode receiving channel block may comprise: a code numerically controlled oscillator block responsive to the code control signal, for providing a numerically controlled oscillator clock signal; and a universal code generator, responsive to the numerically controlled oscillator clock signal and to the mode-generating selection signal, for generating and providing, based on the mode-generating selection signal, a first one of the at least two code signals for a corresponding first one of the at least two types of the code division multiple access receiver processing or a second one of the at least two code signals for a corresponding second one of the at least two types of the code division multiple access receiver processing for further processing by the at least one multimode receiving channel block using said shared circuitry operation. Further still, the universal code generator may contain binary offset carrier capabilities. According further to the first aspect of the invention, the receiver may be a multimode global navigation satellite system receiver. Yet still further, a first one of the at least two code signals may be for global positioning system receiver processing and a second one of the at least two code signals may be for Galileo receiver processing. According to a second aspect of the invention, a method for a shared circuitry operation of a multimode spread spectrum receiver, capable of receiving at least two types of code division multiple access signals, comprises:receiving the radio frequency signal containing said at least two types of code division multiple access signals by an antenna of the multimode spread spectrum receiver and converting said radio frequency signal to a radio frequency electrical signal; converting the radio frequency electrical signal to a digital signal by a preprocessor of the multimode spread spectrum receiver and providing said digital signal to the at least one multimode receiving channel block; and selecting by at least one multimode receiving channel block, based on a predetermined selection criteria, one of at least two types of coding corresponding to one of said at least two types code division multiple access signals and utilizing said coding for further processing of said digital signal by said at least one multimode receiving block using said shared circuitry operation. Further, the digital signal may be a digital intermediate frequency signal, said selection may be performed by the at least one multimode receiving channel block in response to a mode selection signal or to a mode-generating selection signal and finally said at least one multimode receiving channel block may generate, based on said selection, and provide internally one of the at least two code signals to said at least one multimode receiving channel block for implementing said further processing. According further to the second aspect of the invention, the selection by at least one multimode receiving block, based on a predetermined selection criteria, of one of at least two types of coding may comprise: generating a first one of the at least two code signals for a corresponding first one of the at least two types of the code division multiple access receiver processing by a first code generator and generating a second one of the at least two code signals for a corresponding second one of the at least two types of the code division multiple access receiver processing by a second code generator and providing said first one of the at least two code signals and said second one of the at least two code signals to a code selector of the at least one multimode receiving channel block, wherein said first one of the at least two code signals and said second one of the at least two code signals are parts of said at least one multimode receiving channel block; selecting said first one of the at least two code signals or said second one of the at least two code signals by the code selector; and providing the selected said first one of the at least two code signals or said second one of the at least two code signals for further processing by the at least one multimode receiving channel block using said shared circuitry operation. Further, said selecting of said first one of the at least two code signals or said second one of the at least two code signals by the code selector may be based on the mode selection signal provided to the code selector by a receiver processing block. Further according to the second aspect of the invention, before generating the first one of the at least two code signals and the second one of the at least two code signals, the method may further comprise: providing a code control signal to a code numerically controlled oscillator block of the at least one multimode receiving channel block; and generating, in response to said code control signal, a numerically controlled oscillator clock signal by the code numerically controlled oscillator block and providing the numerically controlled oscillator clock signal to the first code generator and to the second code generator. Further, said code control signal may be provided to the code numerically controlled oscillator block by a receiver processing block. Still further, Still further according to the second aspect of the invention, the further processing may be performed by an integrating and dumping block of the at least one multimode receiving channel block. Further, before providing the code control signal, the method may further comprise: generating a data intermediate signal by removing a residual carrier frequency from the digital intermediate frequency signal by a residual carrier removing block of the at least one multimode receiving channel block and providing said data intermediate signal to the integrating and dumping block for further processing. According further to the second aspect of the invention, the selection by at least one multimode receiving block, based on a predetermined selection criteria, of one of at least two types of coding may comprise: generating a first one of the at least two code signals for a corresponding first one of the at least two types of the code division multiple access receiver processing or a second one of the at least two code signals for a corresponding second one of the at least two types of the code division multiple access receiver processing by a universal code generator of the at least one multimode receiving channel block; and providing the first one of the at least two code signals or the second one of the at least two code signals by the universal code generator for further processing by the at least one multimode receiving channel block using said shared circuitry operation. Further, generating the first one of the at least two code signals or the second one of the at least two code signals by the universal code generator may be based on the mode-generating selection signal provided to the universal code generator by a receiver processing block. Still further, before generating the first one of the at least two code signals and the second one of the at least two code signals, the method may further comprise: providing a code control signal to a code numerically controlled oscillator block of the at least one multimode receiving channel block; and generating, in response to said code control signal, a numerically controlled oscillator clock signal by the code numerically controlled oscillator block and providing the numerically controlled oscillator clock signal to the universal code generator. Yet still further, said code control signal may be provided to the code numerically controlled oscillator block by a receiver processing block. According still further to the second aspect of the invention, the further processing may be performed by an integrating and dumping block of the at least one multimode receiving channel block. Further, before providing the code control signal, the method may further comprise: generating a data intermediate signal by removing a residual carrier frequency from the digital intermediate frequency signal by a residual carrier removing block of the at least one multimode receiving channel block and providing said data intermediate signal to the integrating and dumping block for further processing. According further still to the second aspect of the invention, said receiver may be a multimode global navigation satellite system receiver. Still further, a first one of the at least two code signals may be for global positioning system receiver processing and a second one of the at least two code signals may be for Galileo receiver processing. According to a third aspect of the invention, a computer program product comprises: a computer readable storage structure embodying computer program code thereon for execution by a computer processor with said computer program code characterized in that it includes instructions for performing the steps of the method of the second aspect indicated as being performed by the multimode spread spectrum receiver, or by the multimode receiving channel block of said spread spectrum receiver, or by a terminal containing said spread spectrum receiver. According to a fourth aspect of the invention, a system for communicating at least two types of code division multiple access signals received by a multimode spread spectrum receiver with a shared circuitry operation, comprises: at least one satellite, for providing said at least two types of code division multiple access signals, or at least two satellites each providing one of said at least two types of the code division multiple access signals; at least one base station, for providing said at least two types of the code division multiple access signals used for mobile communications; and a terminal, responsive to said at least two different types of the code division multiple access signals, wherein said terminal containing said multimode spread spectrum receiver capable of receiving said at least two types of code division multiple access signals using at least one multimode receiving channel block, responsive to the digital signal indicative of one of said at least two different types of the code division multiple access signals and selecting, based on a predetermined selection criteria, one of at least two types of coding corresponding to said one of the at least two types code division multiple access signals and utilizing said coding for further processing of said digital signal by said at least one multimode receiving block using said shared circuitry operation. According to a fifth aspect of the invention, a multimode receiving module with a shared circuitry operation capable of receiving at least two types of code division multiple access signals and contained in a multimode spread spectrum receiver, comprises: at least one multimode receiving channel block, responsive to the digital signal containing one of said at least two types of the code division multiple access signals and selecting, based on a predetermined selection criteria, one of at least two types of coding corresponding to said one of at least two types code division multiple access signals and utilizing said coding for further processing of said digital signal by said at least one multimode receiving block using said shared circuitry operation, wherein said multimode receiving module is removable from said multimode spread spectrum receiver. | 20040224 | 20071023 | 20050825 | 93052.0 | 0 | TRAN, KHAI | METHOD AND APPARATUS FOR RECEIVING A SIGNAL | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,786,604 | ACCEPTED | Specifying different type generalized event and action pair in a processor | A processor with a generalized eventpoint architecture, which is scalable for use in a very long instruction word (VLIW) array processor, such as the manifold array (ManArray) processor is described. In one aspect, generalized processor event (p-event) detection facilities are provided by use of compares to check if an instruction address, a data memory address, an instruction, a data value, arithmetic-condition flags, or other processor change of state eventpoint has occurred. In another aspect, generalized processor action (p-action) facilities are provided to cause a change in the program flow by loading the program counter with a new instruction address, generate an interrupt, signal a semaphore, log or count the p-event, time stamp the event, initiate a background operation, or to cause other p-actions to occur. The generalized facilities are defined in the eventpoint architecture as consisting of a control register and three eventpoint parameters, namely at least one register to compare against, a register containing a second compare register, a vector address, or parameter to be passed, and a count or mask register. Based upon this generalized eventpoint architecture, new capabilities are enabled. For example, auto-looping with capabilities to branch out of a nested auto-loop upon detection of a specified condition, background DMA facilities, the ability to link a chain of p-events together for debug purposes, and others are all important capabilities which are readily obtained. | 1. An eventpoint chaining apparatus for generalized event detection and action specification in a processing environment comprising: a first processing element having a programmable eventpoint module with an input trigger (InTrig) input and two outputs one which produces an OutTrigger (OT) signal and one which produces an EP interrupt signal; a second processing element having a programmable eventpoint module with an input trigger (InTrig) input and two outputs one which produces an OutTrigger (OT) signal and one which produces an EP interrupt signal, the InTrig input of the second processing element connected to the OT output of the first processing element and the InTrig input of the first processing element connected to the OT output of the second processing element; and a sequence processor interrupt control unit for receiving processing element EP interrupt signals. 2. The apparatus of claim 1 wherein each of said eventpoint modules further comprises: means for detecting a generalized processor event (p-event) comprising a change of state it is desirable to recognize; and means for implementing a generalized processor action (p-action) in acknowledgement in response to the detection of the generalized p-event. 3. The apparatus of claim 1 wherein the first processing element is a sequence processor. 4. The apparatus of claim 1 wherein the first and second processing elements are array processor elements. 5. The apparatus of claim 1 wherein the first and second processing elements both further comprise a special purpose register (SPR) or registers for the storage of the eventpoint parameters. 6. The apparatus of claim 5 wherein eventpoints are separated into two basic classes, instruction eventpoints and data eventpoints and both classes of eventpoints are stored in the SPR file. 7. An eventpoint chaining apparatus for generalized event detection and action specification in a processing environment comprising: a processing element having at least a first and a second programmable eventpoint module each with an input trigger (InTrig) input and two outputs, one which produces an OutTrigger (OT) signal and one which produces an eventpoint (EP) interrupt signal; the InTrig of the second eventpoint module connected to the OT output of the first eventpoint module and the InTrig of the first eventpoint module connected to the OT output of the second eventpoint module for the purpose of chaining eventpoints within the processing element. 8. The apparatus of claim 7 wherein the processing element is a sequence processor. 9. The apparatus of claim 7 wherein one eventpoint module is for an instruction eventpoint and the other eventpoint module is for a data eventpoint. 10. The apparatus of claim 7 wherein both eventpoint modules are for instruction eventpoints. 11. The apparatus of claim 7 wherein both eventpoint modules are for data eventpoints. | RELATED APPLICATIONS This application is a divisional of U.S. Ser. No. 09/598,566 filed Jun. 21, 2000 and claims the benefit of U.S. Provisional Application Ser. No. 60/140,245 filed Jun. 21, 1999 which are incorporated by reference herein in their entirety. FIELD OF THE INVENTION The present invention relates generally to improved techniques for processor event detection and action specification using a generalized mechanism. BACKGROUND OF THE INVENTION A processor event or p-event may be defined as some change of state that it is desirable to recognize. The acknowledgement of a processor event may be termed a processor action or p-action. The purpose of the event-action mechanism, or eventpoint, is to synchronize various actions with specific program and/or data flow events within the processor. Examples of eventpoints which may be encountered include reaching a specified instruction address, finding a specific data value during a memory transfer, noting the occurrence of a particular change in the arithmetic condition flags, accessing a particular memory location, etc. Eventpoints can also include a linked sequence of individual eventpoints, termed chaining, such as finding a specific data value after reaching a specified instruction address, or reaching a second specified instruction address after reaching a first specified instruction address. The p-actions can include changing the sequential flow of instructions, i.e., vectoring to a new address, causing an interrupt, logging or counting an event, time stamping an event, initiating background operations such as direct memory access (DMA), caching prefetch operations, or the like. In previous approaches, each p-event and its consequent p-action typically was treated uniquely and separately from other specific event-actions in order to solve some special problem. One of the many new contributions the architecture of the present invention provides is a generalized eventpoint mechanism. A requirement of the traditional sequential model of computation is that the processor efficiently handle the programming constructs that affect the sequential flow of instructions to be executed on the processor. In the prior art, one of these programming constructs is an auto-looping mechanism, which is found on many digital signal processors (DSPs). Auto-looping is employed to change the program flow for repetitive loops without the need for branch instructions, thereby improving the performance of programs that use loops frequently. Nested loops have also been supported in the prior art. It has also been found imperative that a processor support facilities to debug a program. In the prior art, the capability of setting breakpoints on instructions, data, or addresses that cause a branch to a specified target address or cause an interrupt has been developed. The interrupt or debug branch directs the program flow to a special program that provides debug operations to aid the programmer in developing their software. In another example, it has also been found imperative that a processor support facilities for initiating a DMA operation to occur in the background of normal program execution. In the past, the background DMA capability was typically initiated by specific DMA instructions or instructions specialized for DMA by nature of the side effect that they cause. Consequently, auto-looping, background DMA operation, debug breakpoint capability, and other unique p-events and their consequent p-actions, represent approaches that have been considered separately in the prior art. The present invention generalizes these functions and provides additional unique capabilities that arise due to the generalization of the various p-events and p-actions in a common architecture thereby providing a common design and program approach to the development and use of all of these types of functions. SUMMARY OF THE PRESENT INVENTION The present invention addresses the need to provide a processor with a generalized p-event and p-action architecture which is scalable for use in a very long instruction word (VLIW) array processor, such as the ManArray processor. In one aspect of the invention, generalized p-event detection facilities are provided by use of a compare performed to discover if an instruction address, a data memory address, an instruction, a data value, arithmetic-condition flags, and/or other processor change of state eventpoint has occurred. In another aspect of this invention, generalized p-action facilities are provided to cause a change in the program flow by loading the program counter with a new instruction address, generating an interrupt, generating a log, counting the p-event, passing a parameter, etc. The generalized facilities may be advantageously defined in the eventpoint architecture as consisting of a control register and three eventpoint parameters: 1) a register to compare against, 2) a register containing a second compare parameter, vector address, or parameter to be passed, and 3) a count or mask register. Based upon this generalized eventpoint architecture, new capabilities are supported that extend beyond typical prior art capabilities. For example, auto-looping with capabilities to branch out of a nested auto-loop upon detection of a specified condition, background DMA facilities, and the ability to link a chain of p-events together for debug purposes, among others are all new capabilities easily obtained by use of this invention. A more complete understanding of the present invention, as well as other features and advantages of the invention, will be apparent from the following Detailed Description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates an exemplary 2×2 ManArray iVLIW processor suitable for use in conjunction with the present invention; FIG. 2A illustrates an exemplary load from special purpose register (LSPR) instruction encoding; FIG. 2B illustrates an exemplary load from special purpose register syntax/operation description; FIG. 3A illustrates an exemplary store to special purpose register (SSPR) instruction encoding; FIG. 3B illustrates an exemplary store to special purpose register syntax/operation description; FIG. 4 illustrates an exemplary placement of eventpoint registers in an special purpose register file (SPRF) in accordance with the present invention; FIG. 5 illustrates an exemplary instruction eventpoint high level logic flow diagram; FIGS. 6A-6G illustrate exemplary decode and control logic descriptions for instruction eventpoint modules in accordance with the present invention; FIG. 7A illustrates an exemplary event point loop (EPLOOP) instruction encoding in accordance with the present invention; FIG. 7B shows a syntax/operation table for the EPLOOP instruction of FIG. 7A; FIG. 7C illustrates an exemplary event point loop immediate (EPLOOPI) instruction encoding in accordance with the present invention; FIG. 7D shows a syntax/operation table for the EPLOOPI instruction of FIG. 7C; FIG. 8 illustrates a ManArray pipeline timing diagram for the EPLOOP instruction of FIG. 7A; FIG. 9 illustrates an exemplary data eventpoint high level logic flow diagram; FIGS. 10A-10J illustrate exemplary decode and control logic descriptions for data eventpoint modules in accordance with the present invention; FIG. 11 illustrates an exemplary eventpoint chaining apparatus in accordance with the present invention; and FIGS. 12A-12C illustrate aspects of an exemplary background DMA eventpoint program in accordance with the present invention. DETAILED DESCRIPTION Further details of a presently preferred ManArray core, architecture, and instructions for use in conjunction with the present invention are found in U.S. patent application Ser. No. 08/885,310 filed Jun. 30, 1997, now U.S. Pat. No. 6,023,753, U.S. patent application Ser. No. 08/949,122 filed Oct. 10, 1997, U.S. patent application Ser. No. 09/169,255 filed Oct. 9, 1998, U.S. patent application Ser. No. 09/169,256 filed Oct. 9, 1998, U.S. patent application Ser. No. 09/169,072 filed Oct. 9, 1998, U.S. patent application Ser. No. 09/187,539 filed Nov. 6, 1998, U.S. patent application Ser. No. 09/205,558 filed Dec. 4, 1998, U.S. patent application Ser. No. 09/215,081 filed Dec. 18, 1998, U.S. patent application Ser. No. 09/228,374 filed Jan. 12, 1999, U.S. patent application Ser. No. 09/238,446 filed Jan. 28, 1999, U.S. patent application Ser. No. 09/267,570 filed Mar. 12, 1999, U.S. patent application Ser. No. 09/337,839 filed Jun. 22, 1999, U.S. patent application Ser. No. 09/350,191 filed Jul. 9, 1999, U.S. patent application Ser. No. 09/422,015 filed Oct. 21, 1999, U.S. patent application Ser. No. 09/432,705 filed Nov. 2, 1999, U.S. patent application Ser. No. 09/471,217 filed Dec. 23, 1999, U.S. patent application Ser. No. 09/472,372 filed Dec. 23, 1999, U.S. patent application Ser. No. 09/596,103, filed Jun. 16, 2000, now U.S. Pat. No. 6,397,324, U.S. patent application Ser. No. 09/598,567, filed Jun. 21, 2000, U.S. patent application Ser. No. 09/598,564 filed Jun. 21, 2000, now U.S. Pat. No. 6,662,234, U.S. patent application Ser. No. 09/598,558, filed Jun. 21, 2000, and U.S. patent application Ser. No. 09/598,084 filed Jun. 21, 2000, as well as, Provisional Application Ser. No. 60/113,637, filed Dec. 23, 1998, Provisional Application Ser. No. 60/113,555, filed Dec. 23, 1998, Provisional Application Ser. No. 60/139,946, filed Jun. 18, 1999, Provisional Application Ser. No. 60/140,245, filed Jun. 21, 1999, Provisional Application Ser. No. 60/140,163, filed Jun. 21, 1999, Provisional Application Ser. No. 60/140,162, filed Jun. 21, 1999, Provisional Application Ser. No. 60/140,244, filed Jun. 21, 1999, Provisional Application Ser. No. 60/140,325, filed Jun. 21, 1999, Provisional Application Ser. No. 60/140,425, filed Jun. 22, 1999, Provisional Application Ser. No. 60/165,337, filed Nov. 12, 1999, Provisional Application Ser. No. 60/171,911, filed Dec. 23, 1999, Provisional Application Ser. No. 60/184,668, filed Feb. 24, 2000, Provisional Application Ser. No. 60/184,529, filed Feb. 24, 2000, Provisional Application Ser. No. 60/184,560, filed Feb. 24, 2000, Provisional Application Ser. No. 60/203,629, filed May 12, 2000, and Provisional Application Ser. No. 60/121,987 filed Jun. 21, 2000, respectively, all of which are assigned to the assignee of the present invention and incorporated by reference herein in their entirety. In order to support generalized p-event detection, p-event counting, and p-action flow control or parameter passing, a minimum of two parameters are used with generally three parameters utilized. These three general parameters are defined in the eventpoint architecture as a first register to compare against, a second optional register containing either a second compare parameter, a vector address, or parameter to be passed, and a third register acting as a p-event counter or a mask. To allow flexibility in the control of how these three parameters are used, a control register is employed for each eventpoint set of the three parameters. The control register content specifies the type of comparison that is to be made and defines the action to be taken. For example, an eventpoint can be uniquely identified when a compare match occurs between the first compare register parameter and a specified processor state, or when a chain of eventpoints occurs in some logical or sequential fashion. Some of the possible processor states that can be compared for include an instruction address, a specific instruction, a VLIW Memory (VIM) address, a data memory address, a memory or register file data value, flags, a control register value, and the like. The control register also defines how the eventpoint is to be treated and the p-action that is to occur. Some p-actions make use of the second register parameter. For example, the second register parameter can contain a vector address that is loaded in the program counter upon a p-event detection, thereby directing the program to a debug routine or the beginning of a program loop. Other examples include: starting a background operation at an eventpoint, such as a DMA operation, and using the second parameter register to pass a variable to the DMA hardware, generating an interrupt at the eventpoint and using the second parameter register to pass a variable to the interrupt routine, and the like. Other p-actions include counting the p-event, link to and enable another eventpoint, etc. The determination of whether a p-event is used directly to cause a p-action, or whether multiple occurrences of the same p-event are required before causing a p-action, is made by the control register in conjunction with the third count parameter. The eventpoint counter is tested for a zero state, a one state, or other state indicating it contains some count value. These three states can be tested for at different eventpoints and different p-actions can result. An eventpoint (EP) auto-loop with unique capabilities can be specified as a subset of the capabilities of the present invention. For example, an EP auto-loop can be set up that skips the loop completely if the count is zero at the loop start address, or an auto-loop can be set up that allows a conditional exit from the auto-loop based upon the state of an arithmetic condition flag. It is noted that depending upon the application, the scope of and requirements for the generalized eventpoint hardware can vary. Consequently, it is desirable to have a standard architectural approach for implementation and programmer use. To demonstrate the apparatus and use of this invention in the context of a presently preferred processor, the next sections describe in detail the incorporation of this generalized eventpoint architecture into the scalable indirect-VLIW ManArray processor. In a preferred embodiment of the present invention, a ManArray 2×2 iVLIW single instruction multiple data stream (SIMED) processor 100 shown in FIG. 1 contains a controller sequence processor (SP) combined with processing element-0 (PE0) SP/PE0 101, as described in further detail in U.S. application Ser. No. 09/169,072 entitled “Methods and Apparatus for Dynamic Merging an Array Controller with an Array Processing Element”. Three additional PEs 151, 153, and 155 are also utilized to demonstrate the generalized processor event detection and action specification architecture and design apparatus for the present invention. The SP/PE0 101 contains a fetch controller 103 to allow the fetching of short instruction words (SIWs), also known as native instructions, from a B=32-bit instruction memory 105. The fetch controller 103 provides the typical functions needed in a programmable processor, such as a program counter (PC), branch capability, eventpoint (EP) loop control operations, support for interrupts, and also provides the instruction memory control which could include an instruction cache if needed by an application. In addition, the SIW I-Fetch controller 103 dispatches 32-bit SIWs to the other PEs in the system by means of the 32-bit instruction bus 102. In this exemplary system, common elements are used throughout to simplify the explanation, though actual implementations need not be so limited. For example, the execution units 131 in the combined SP/PE0 101 can be separated into a set of execution units optimized for the control function, for example, fixed point execution units, and the PE0 as well as the other PEs 151, 153 and 155 can be optimized for a floating point application. For the purposes of this description, it is assumed that the execution units 131 are of the same type in the SP/PE0 and the other PEs. In a similar manner SP/PE0 and the other PEs are shown as all using a five instruction slot iVLIW architecture which contains a very long instruction word memory (VIM) 109 and an instruction decode and VIM controller function unit 107 which receives instructions as dispatched from the SP/PE0's I-Fetch unit 103 and generates the VIM addresses-and-control signals 108 required to access the iVLIWs stored in the VIM. Store, load, arithmetic logic unit (ALU), multiply accumulate unit (MAU), and data select unit (DSU) instruction types are identified by the letters SLAMD in VIM 109 as follows; store (S), load (L), ALU (A), MAU (M), and DSU (D). The loading of the iVLIWs is described in further detail in U.S. patent application Ser. No. 09/187,539 entitled “Methods and Apparatus for Efficient Synchronous MIMD Operations with iVLIW PE-to-PE Communication”. Also contained in the SP/PE0 and the other PEs is a common PE configurable register file 127 which is described in further detail in U.S. patent application Ser. No. 09/169,255 entitled “Methods and Apparatus for Dynamic Instruction Controlled Reconfiguration Register File with Extended Precision”. Due to the combined nature of the SP/PE0, the data memory interface controller 125 must handle the data processing needs of both the SP controller, with SP data in memory 121, and PE0, with PE0 data in memory 123. The SP/PE0 controller 125 also is the source of the data that is sent over the 32-bit or 64-bit (depending upon implementation) broadcast data bus 126 and contains a special purpose register file (SPRF) and instruction and data eventpoint modules described in this invention. The other PEs, 151, 153, and 155 contain common physical data memory units 123′, 123″, and 123″ though the data stored in them is generally different as required by the local processing done on each PE. The interface to these PE data memories is also a common design in PEs 1, 2, and 3 and indicated by PE local memory and data bus interface logic 157, 157′ and 157″. The interface logic units 157, 157′, and 157″ also contain the PEs SPRF and data eventpoint modules described further below. Interconnecting the PEs for data transfer communications is the cluster switch 171 more completely described in U.S. Pat. No. 6,023,753 entitled “Manifold Array Processor”, U.S. patent application Ser. No. 08/949,122 entitled “Methods and Apparatus for Manifold Array Processing”, and U.S. patent application Ser. No. 09/169,256 entitled “Methods and Apparatus for ManArray PE-to-PE Switch Control”. The interface to a host processor, other peripheral devices, and/or external memory can be implemented in many ways. The primary mechanism shown for completeness is contained in a direct memory access (DMA) control unit 181 that provides a scalable ManArray data bus 183 that connects to devices and interface units external to the ManArray core. The DMA control unit 181 provides the data flow and bus arbitration mechanisms needed for these external devices to interface to the ManArray core memories including the VIM via the multiplexed bus interface represented by line 185. A high level view of the ManArray control bus (MCB) 191 is also shown. All of the above noted patents and applications are assigned to the assignee of the present invention and incorporated herein by reference in their entirety. Generalized Eventpoint Description Each eventpoint specifies a set of one or more p-events which are to be monitored and the associated p-actions to perform when they occur. As part of the architecture definition, the eventpoints are separated into two basic classes: instruction eventpoints and data eventpoints. This separation allows a better utilization of the control register that specifies the eventpoints, though having a bit in the control register that selects instruction or data type eventpoints is not precluded. Both classes of eventpoint parameters and controls are stored in registers located in a ManArray special purpose register file (SPRF). SPRs are registers that provide specialized control and/or communication capabilities to the array processor. Most SPRs are accessible by the SP, but some are implemented in both the SP's SPR address space and in the PE's SPR address space. These registers are accessible in 1-cycle by the SP (or PE) when using the Load SPR (LSPR) instruction encoding format 200 shown in FIG. 2A, or store SPR (SSPR) instruction, having encoding format 300 of FIG. 3A. Syntax/operation tables 210 and 310 for these instructions are shown in FIGS. 2B and 3B, respectively. The LSPR instruction loads a byte, half-word, or word operand into an SP target register from an SP special-purpose register or into a PE target register from a PE special-purpose register. The SPR to load from is specified by its SPR Address SPRADDR. The SSPR instruction stores a byte, half-word, or word operand to an SP special-purpose register from an SP source register or to a PE special-purpose register from a PE source register. The SPR being stored to is specified by its SPR Address SPRADDR. The SP and each PE contains an SPR file, each optimized according to its use. FIG. 4 shows an exemplary SPR register map 400 providing details of the placement of the instruction and data eventpoint registers in the ManArray SPR address space. The leftmost column 401 contains the specific system addresses for the eventpoint registers 410 as seen from the ManArray control bus (MCB). The next column 403 has the core SP/PE addresses for the eventpoint registers 410 as identified in the rightmost three columns 405, 407 and 409. The eventpoint SPRs have a guaranteed single cycle access. The primary mechanism to access to the SPRs is through the use of load and store SPR instructions that move data between the compute register file (CRF) and the SPRs. It is also possible to set the eventpoints via a system ManArray control bus (MCB). In that case, it takes multiple cycles to set up an eventpoint. Even though no architecture limit is set for the total number of eventpoints that can be implemented, there is a practical limit dictated by the functionality desired. For example, one ManArray implementation specifies six instruction and three data eventpoints in the SP and a single data eventpoint in each PE. It is noted that each eventpoint has associated with it a small 8-bit control register and up to three parameter registers. The ManArray implementation is used as one suitable and presently preferred implementation in the description of the invention which follows. Instruction Eventpoints An instruction eventpoint (IEP) implementation is described first. FIG. 5 depicts an exemplary instruction eventpoint module 500 having three eventpoint registers, comprising two half-word 16-bit registers 516 and 518, and two other eventpoint registers 524, and 528, an 8-bit control register 514 comprising a plurality of instruction eventpoint control bits, eventpoint decode and control logic 510 and the interfaces necessary for implementing the generalized instruction eventpoint architecture of the present invention. The IEPxR2.H0 register 518 is operable as a counter whose initial count value is loadable under program control. The plurality of instruction eventpoint control registers are byte-wide registers with one such assigned for each instruction eventpoint, for example, register 514. The eventpoint control registers for up to eight instruction eventpoints are stored in two 32-bit registers, IEPCTL0 and IEPCTL1, located in the SP SPR file and formatted as shown in the tables below: IEPCTL0 Register Reset Value = 0x00000000 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 S P T IEP3 S P T IEP2 S P T IEP1 S P T IEP0 3 3 3 2 2 2 1 1 1 0 0 0 IEPCTL1 Register Reset Value = 0x00000000 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 S P T IEP7 S P T IEP6 S P T IEP5 S P T IEP4 7 7 7 6 6 6 5 5 5 4 4 4 Reserved in Example System Each evenpoint “x” has associated with it an IEPx control byte that specifies how the three evenpoint parameter registers IEPxR0, IEPxR1 and IEPxR2 are used for detecting instruction events and generating corresponding actions as explained further below. Each control byte is made up of a three bit field labeled (SPT) and a five bit field labeled with the instruction event point number (IEPx). The SPT encoding and meanings are given in the follow table: Code (SPT) Meaning 000 No EP Interrupt, OutTrigger InTrigger, InTriggerFF always set 001 No EP Interrupt, OutTrigger InTrigger, InTriggerFF from InTrigger 010 No EP Interrupt, OutTrigger control logic, InTriggerFF always set 011 No EP Interrupt, OutTrigger control logic, InTriggerFF from InTrigger 100 EP Interrupt, OutTrigger InTrigger, InTriggerFF always set 101 EP Interrupt, OutTrigger InTrigger, InTriggerFF from InTrigger 110 EP Interrupt, OutTrigger control logic, InTriggerFF always set 111 EP Interrupt, OutTrigger control logic, InTriggerFF from InTrigger In general, the control logic for each eventpoint receives an input trigger signal from a predecessor eventpoint and generates a trigger signal output to a successor eventpoint. In the exemplary ManArray implementation, all SP resident eventpoints (IEP0-IEP5 and SP DEP0-DEP2) are inked in a circular chain so that it is possible to support chaining of the eventpoints. The SPT bits are defined as follows: S Signal bit. Used to control output signal generation from eventpoint logic. This bit is primarily used to indicate whether or not an EP interrupt signal will be generated when the specified event occurs, but may be used for other purposes for some specialized types of event points. P Pass-through control bit. This bit is most commonly used to indicate pass-through of the InTrigger signal from input to output. If this bit is a “0”, then the InTrigger signal is passed from input to output of the eventpoint logic. If this bit is a “1” then the InTrigger signal is not passed to the output of the eventpoint logic. T Trigger function bit. This bit is used to control the use of the InTrigger and/or InTriggerFF signals within the eventpoint logic. Its use is dependent on the control code (IEPx fields). The term InTrigger refers to an input signal representing that a p-event has been detected. The term InTriggerFF refers to a latched signal to enable event monitoring. OutTrigger refers to an output control signal indicating a p-event has been detected, and EP Interrupt refers to whether an eventpoint interrupt is specified to occur on detecting the eventpoint. The detection of a p-event is indicated in the generation of an OutTrigger signal which is connected to the InTrigger input of the next eventpoint logic module to allow chaining of eventpoints. EP Interrupt is an output of an eventpoint module that can be enabled to cause an interrupt depending upon the encoding of the eventpoint control. In the exemplary ManArray architecture, the eventpoint interrupt is also termed the debug interrupt. The following table describes these signals in greater detail: InTriggerFF The InTrigger flip-flop is a non-programmer-visible register bit used to enable event monitoring. The control of this bit depends on the value programmed into the event point control register ‘T’ bit, and on the event point operation code (IEPx). InTrigger This signal is used to designate the unlatched input trigger signal which is the OutTrigger signal from the previous event point module in the chain (see eventpoint chaining description). OutTrigger This non-programmer visible signal is an output from an event point control logic or from the InTrigger signal. The source of this signal depends on the setting of the ‘S’ bit and the operation code in the event point's control field. EXTOUT This signal is asserted in Data Event Point control modes when the event point counter is being used as a semaphore and an address match has occurred with a non-zero count present. (In the example implementation this is used for DMA data flow control and these signals are connected to inputs in the DMA controller which cause semaphore increments). EP Interrupt This is a signal which allows the generation of an eventpoint interrupt (also known as a debug interrupt) based on the occurrence of a detected event. The source of this signal depends on the setting of the ‘S’ bit and the operation code in the event point's control field. Operation utilizing these signals is illustrated in FIG. 5 and described in more detail in the following sections. In FIG. 5, the programmer/compiler specified content of the control register 514 is one of the byte fields from the 32-bit IEPCTL0 or IEPCTL1. The eventpoint control information is conveyed on the 8-bit output of the {SPT, IEPx} byte register on signal lines 529 to the decode and control logic 510. Details for the three other eventpoint registers 524, 528, and the half-word 16-bit registers 516 and half-word counter register 518 for eventpoint “x” are shown in more detail in the tables below: IEPxR0 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 IEPxR0.W (compare value) IEPxR1 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 IEPxR1.W (compare value) IEPxR2 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 IEPxR2.H1 IEPxR2.H0 Reload Count Event Count IEPxR0 524 holds a programmer-specified value, that had been loaded via a store to special purpose register (SSPR) instruction, as illustrated in FIGS. 3A and 3B, over the SPR bus 517, which consists of address, data, and control, that is to be compared with a selected bus signal 521. Multiplexer 534 selects either the instruction fetch address bus 519 or other implementation specific bus signal 557 by means of multiplexer control signal 563. The multiplexer control signal 563 is generated based upon the decoding of the eventpoint control register IEPCTLz.By 514 contents, where z=0 or 1 and By represents the yth control byte of the 32 bit IEPCTLz control register. IEPxR0 524 contains either an address value (an instruction fetch address, a load unit's effective address, or a store unit's effective address) or an instruction as a data value. The exemplary implementation, though not architecturally limited to this, shown in FIG. 5 provides for two compare IEPxR0 paths: the instruction fetch address bus 519 and the other bus signal 557 which could be an instruction bus, for example. For use in EP auto-loop constructs, the IEPxR0 register 524 is loaded, via the SSPR instruction, with the address of the last instruction in a program loop. During each instruction fetch, the contents of the IEPxR0 register 524 are compared with the instruction fetch address. When comparator 526 detects a match as indicated by signal 539, then, if the count value in the associated IEPxR2.H0 counter register 518 is greater than one, the program counter is loaded with the contents of the associated IEPxR1 register 528, which contains the address of the first instruction in the EP loop, to start a new iteration of the EP loop. The value stored in the IEPxR1 register 528 represents the programmer-specified value that had been loaded via the SSPR instruction either over the SPR bus 517, which consists of address, data, and controls, or the instruction fetch address bus 519 as selected by multiplexer 530 under control of the decode and control logic 510 and control output signal 561. The value loaded into the IEPxR1 register 528 is either passed to a background operation, over the EPxBus 551 or is used as an address to be loaded into the program counter (PC) as is done in eventpoint looping, using the EPxBus 551, to change the flow of the program to a new start address. The value placed upon the EPxBus 551 is accompanied by a load EPxBus signal 549. The IEPxR2 register is split into two half-word portions IEPxR2.H1 516 and IEPxR2.H0 518. The IEPxR2.H0 counter register 518 portion contains a programmer specified count value that is counted down on the detection of each event by counter hardware included in register 518. Certain eventpoints can cause the counter to be incremented. The counter register is useful for the counting of events and indicating if a count is pending or if, on a count down operation, it has reached a 1 or a 0. The count pending output, count=1 or count=0 situation is detected in detector block 522 connected to counter register output 235 and the appropriate signal 537 is sent to the decode and control logic 510. Both halfword portions of IEPxR2 are loaded over the SPR bus 517, which consists of address, data, and controls, and the IEPxR2.H0 portion can also be loaded with the IEPxR2.H1 value 531 as selected by multiplexer 520 to pass through to input 533, depending upon the event as controlled by the decode and control logic 510 based upon the control register 514. For example, in EP auto-loops when the end of the EP loop is reached, or, in other words, the IEPxR2.H0 is equal to 1 and the address in the associated IEPxR0 register matches the instruction fetch address, the contents of IEPxR2.H0 are replaced with the reload count IEPxR2.H1. Another option available to the eventpoint logic is to cause an EP interrupt 547 that changes the program flow to an EP interrupt routine useful for analysis and problem solving. The operation of decode and control logic 510 is discussed below in connection with exemplary decode and control logic descriptions 600, 640, 650, 660, 670, 680, and 690 shown in FIGS. 6A-6G, where the control value, {Sx, Px, Tx, IEPx}, represents the byte control field loaded in control register 514 and is shown as SPTxxxxx. An operation column 601 of the tables describes the operation of the decode and control logic 510, use of the inputs, and specifies the output generation. A control value column 602 contains a functional description of the operation. FIG. 6A will be explained in detail to describe the general operation of the eventpoint logic. On power on, line 603, the control value for eventpoint ‘x’ is ‘00000000’ which indicates the eventpoint ‘x’ is disabled, no action is to be specified, and the InTrigger signal 515 of FIG. 5 is passed through the multiplexer 508 to the OutTrigger signal 545. When the IEPCTLz.By control byte is loaded with a value ‘00T11000’ 604, the eventpoint is enabled to eventpoint looping, skip the loop if the count is zero, and if T=1 then InTrigger can be used to exit or skip the loop. In the operation description 601, pseudo code describes the control logic for this control code encoding. The symbols used are as follows: // precedes comments, == is the equality operator, && is the logical AND operator, ∥ is the logical OR operator, and A←B indicates the signal A or register A is assigned the value of the signal B or register B, respectively. Beginning at the top of FIG. 6A and noting references to FIG. 5, line 605 indicates the OutTrigger signal 545 is always assigned the InTrigger signal 515. The next two lines 606 and 607 indicate that if T=1, then the InTriggerFF 512 is set by the InTrigger signal 515. If this occurs, then the logic can exit or skip the loop dependent upon a previous event OutTrigger. This external event trigger is termed eventpoint chaining and is described in further detail below. Lines 608 and 609 cover the case where T=0. When T=0, then the InTriggerFF is set to a “1” which enables this eventpoint module and does not react to any external trigger event. Line 610 indicates that “When” the value in the program counter (PC), or, in other words, the instruction fetch address, equals the value stored IEPxR0 OR the value of the PC equals the value stored in IEPxR1, then some type of action is to be taken. It is noted that for use in eventpoint looping the value stored in IEPxR0 is the last instruction in a program loop and the value stored in IEPxR1 is the first instruction of the program loop. Statement 610 indicates that when the program counter reaches either the start of a program loop or the last instruction in a program loop some p-action is to be taken. When this compare point is reached, the next line 611 indicates a compare 532 of the instruction fetch address 519 with the IEPxR1 551 which at the match point indicates the program counter has reached the first instruction of a loop. If this compare is true AND either the trigger is enabled AND active (line 612) OR the loop count is zero (line 613), then the p-action of lines 614-617 is to occur. Line 614 indicates the PC is loaded with the end of loop address, causing a jump to the end of the loop. The loop counter is reinitialized as indicated in line 615 and the InTriggerFF is cleared in line 616 to prepare it for another event detection. It is noted that since the PC was directed to the last instruction in the loop and the loop is to be bypassed this “last instruction in the loop” is canceled in line 617. It is further noted that this canceling procedure was done in this exemplary implementation to avoid a timing path problem with having an adder in the path to load “last instruction in the loop+1”. Alternative implementations may choose to implement this adder scheme which is also supported by the present invention. When the program counter indicates a match with the loop end address, line 618, through a compare of the instruction fetch address 519 and IEPxR0 525, then the program sequence can either 1) fall out of the loop if a different trigger event has occurred, 2) fall out of the loop if the loop count indicates the loop has been completed or is zero for the single instruction loop case, or 3) branch back to the beginning of the loop if the loop is not complete. The next logic segment, lines 619-622, represents the logic and actions that are to occur if a different trigger event has occurred. In line 619, the requirement is: if T=1 AND InTriggerFF==1 which if true indicates the trigger is enabled and active. In FIG. 5, this logic is in the decode and control logic block 510 which receives input 527 from the InTriggerFF (InTFF) register 512. Given line 619 is true, then falling out of the loop, with a good probability that the number of loop iterations did not complete, is accomplished by line 620 which requires the hardware to load the program counter with the next sequential program step, i.e., taking the program away from the loop. In addition, line 621 requires the eventpoint to be reinitialized in case the loop is entered again by loading the loop reload count stored in IEPxR2.H1 into IEPxR2.H0. This reload path is implemented in FIG. 5 by lines 531 which connect the output of the reload count register IEPxR2.H1 to a multiplexer 520 which multiplexes this output with a signal on programming SPR path 517, which consists of address, data, and controls, as selected by the decode and control logic 510 to place the reload count value on the multiplexer output 533 for loading into the loop counter register 518 IEPxR2.H0. Further, the trigger event which caused the loop to exit is reset as indicated in line 622. The second case is covered by the “else” clause of line 623 which indicates a hardware compare of the loop counter output testing for a zero or one count. In FIG. 5, this is implemented in hardware in block 522 that tests the output of the IEPxR2.H0 counter register 518 and sends the results to the decode and control block 510. If this situation is detected, then the loop is to be exited due to count completion, or if the loop count had been loaded with a zero, then the program loop is not to be repeated. Consequently, line 624 requires the program counter to be loaded with the next sequential program address and line 625 requires the loop count to be reinitialized to the value stored in the reload count IEPxR2.H1. If these conditions are not met, line 626, then the loop count is neither a 0 nor a 1 and since the program counter is at the last instruction in the loop the loop is to be repeated. Consequently, the program counter is loaded with the loop “start” address IEPxR1 627. This loading is accomplished by sending the start address IEPxR1 value on the EPxBus 551 and a load EPxBus signal 549 to the program counter causing the PC to be loaded and directing the program flow back to the beginning of the loop. Line 628 indicates the loop counter register 518 is to be decremented indicating the loop has completed another execution sequence. This ends the logic operation description of what happens when the PC is at the end address of a loop. FIGS. 6B-6G illustrate other forms of instruction eventpoint operations providing a programmer with unique capabilities due to the general approach taken for the architecture. For example, FIGS. 6C and 6D illustrate the logic operation for loop operations that can exit based on the state of the F0 arithmetic condition flag. FIG. 6E represents the logic operation for generating an EP or debug interrupt with optional pre-count and pre-trigger. The approach of FIG. 6F is useful for vectoring or branching to a target address after count matches have occurred. The approach of FIG. 6G is used to generate an EP interrupt after count InTriggers have been received. It will be appreciated that other eventpoint operations are easily achieved for numerous purposes using this architectural and programming approach for eventpoints. Another aspect of this invention regards handling single instruction loops where the loop start address and loop end address are the same. To ensure correct operation, the instruction eventpoints have a priority associated with them to handle situations where more than one eventpoint asserts its control to load the PC with the next fetch address. The priority is chosen such that when a program uses nested loops that share starting and/or ending addresses, the inner most loop should be the lowest numbered eventpoint. The priority is as follows: 1) eventpoint 0 load of PC with IEP0R1 * 2) eventpoint 1 load of PC with IEP1R1 * 3) eventpoint 2 load of PC with IEP2R1 * 4) eventpoint 3 load of PC with IEP3R1 * 5) eventpoint 4 load of PC with IEP4R1 * 6) eventpoint 5 load of PC with IEP5R1 * 7) eventpoint 5 load of PC with IEP5R0 8) eventpoint 4 load of PC with IEP4R0 9) eventpoint 3 load of PC with IEP3R0 10) eventpoint 2 load of PC with IEP2R0 11) eventpoint 1 load of PC with IEP1R0 12) eventpoint 0 load of PC with IEP0R0 For the asterixed items above, this priority is used in the logic provided that one of the two following statements is true: a) the eventpoint is configured as a loop and no higher numbered eventpoint asserts control to skip a loop, or b) for those alternative uses of the eventpoint logic, the eventpoint is not configured as a loop. Eventpoint Looping To minimize the number of set-up cycles, specialized instructions, a set up and execute an instruction eventpoint loop (EPLOOPx) instruction encoding 700 shown in FIG. 7A and a set up and execute an instruction eventpoint loop immediate (EPLOOPIx) instruction encoding 720 shown in FIG. 7C may be advantageously employed. The syntax/operation descriptions 710 and 730 for these instructions are shown in FIGS. 7B and 7D, respectively. The EPLOOPx instruction 700 sets up and executes a program loop beginning with the next sequential instruction. The instruction eventpoint register (IEPxR1) is loaded with the address of the next sequential instruction, representing the start address of the first instruction in the loop. The instruction event point register (IEPxR0) is loaded with the address of the last instruction in the loop, which is the sum of the address of the LOOP instruction and a 10-bit unsigned displacement UDISP10 which is produced in the assembly using a label. The appropriate instruction eventpoint control field IEPx, IEP0-IEP3, in the IEPCTL0 register is loaded with the hexadecimal value 0x18. If the loop counter (IEPxR2.h0) is non-zero, execution proceeds with the next sequential instruction. If the loop counter is zero, the body of the loop is skipped and execution proceeds with the next sequential instruction after the address in IEPxR0. While a loop is active (Loop Counter>0) each instruction address is compared to the IEPxR0. When there is a match and Loop Counter>1, PC is set to IEPxR1 and the Loop Counter is decremented. When there is a match and Loop Counter=1, the Loop Counter is loaded with the Loop Reload Value and the loop is exited. It is noted that the “x” in EPLOOPx, IEPxR0, IEPxR1 and IEPxR0 is equal to the BPID value 0, 1, 2 or 3. The EPLOOPIx instruction 720 shown in FIG. 7C sets up and executes a program loop beginning with the next sequential instruction. The instruction eventpoint register (IEPxR1) is loaded with the address of the next sequential instruction. The instruction eventpoint register (IEPxR0) is loaded with the address of the last instruction in the loop, which is the sum of the address of the EPLOOPI instruction and the 10-bit unsigned displacement UDISP10. The instruction eventpoint register (IEPxR2) is loaded with the unsigned 12-bit value LoopCnt, placing the value in both the upper and lower half-words. The appropriate instruction eventpoint control field IEPx, IEP0-IEP3, in the IEPCTL0 register is loaded with the hexadecimal value 0x18. If the loop counter (IEPxR2) is non-zero, execution proceeds with the next sequential instruction. If the loop counter is zero, the body of the loop is skipped and execution proceeds with the next sequential instruction after the IEPxR0. While the loop counter is greater than zero, a loop is active and each instruction address is compared to the IEPxR0. When there is a match and the loop counter is greater than one, PC is set to IEPxR1 and the loop counter is decremented. When there is a match and the loop counter equals one, the loop counter is loaded with the loop reload value and the loop is exited. The EPLOOP and EPLOOPI instructions 700 and 720 are used to provide a low latency mechanism for a select group of the eventpoints. The exemplary ManArray architecture allows up to four nested eventpoint loops so as to better optimize utilization of the eventpoint hardware and conserve bits in the EPLOOP instructions. Specifically, the four eventpoints are specified in the EPLOOP and EPLOOPI instructions, by means of the BPID encoding in bits 23-22, for this purpose. An exemplary pipeline timing diagram 800 for a ManArray processor implementation for the start up sequence of the EPLOOPx instruction 700 for a multi-instruction program loop is shown in FIG. 8. It is noted that for the EPLOOPx instruction the loop count is loaded using the SSPR instruction prior to issuing the EPLOOPx instruction. EPLOOPIx simplifies this further by not requiring a separate load of the loop count value as it is already contained in an immediate field 722, bits 21-10 in the instruction 720 of FIG. 7C. The pipeline timing diagram 800 of FIG. 8 is made up of five columns: a clock cycle indicator column 802 which is set to zero as a reference point for the fetch of the EPLOOPx instruction, an EP compare column 804 indicating when the compares for a program loop occur, a fetch column 806 indicating the instruction fetch sequencing, a decode column 808 indicating the operations that occur during decode, and an execute column 810 indicating the operations that occur during execute. Beginning with cycle 0 shown in row 812, the EPLOOPx instruction is fetched and prior instructions continue to execute. In cycle 1 shown in row 814, the first instruction of the program loop is fetched. In the decode phase, the end address for the loop is calculated as program counter value plus a 10-bit displacement obtained from the EPLOOPx instruction. The program counter is held, and a no-operation (NOP) instruction is inserted in the pipe. Also, in the execute phase, the previous instruction to the EPLOOPx instruction is executed. In cycle 2 shown in row 816, no new instruction is fetched as the first instruction of the program loop has already been fetched. In the decode phase, the hardware executes the NOP that was inserted in the pipe in the previous cycle. In the execute phase, the end address is sent to the IEPx module on the SPR bus and loaded into IEPxR0. The program counter value is loaded into IEPxR1 representing the start address of the loop. The program counter is still held, and a second NOP instruction is inserted in the pipe. In cycle 3 shown in row 818, the first compare of IPExR0 loop start address with the program counter is done with a match signal generated. The first instruction of the loop is allowed to continue in the pipe. In the decode phase, the second inserted NOP is decoded. In the execute phase, the first inserted NOP is executed. In cycle 4 shown in row 820, the next or second instruction of the program loop is fetched. In the decode phase, the first instruction of the loop is decoded. In the execute phase, the second inserted NOP is executed. In cycle 5 shown in row 822, the processing continues to proceed with fetching, decoding, and executing the instructions in the program loop. Data Eventpoints FIG. 9 shows an exemplary data eventpoint module 900 having three data eventpoint registers, comprising two half-word 16-bit registers 916 and 918, and two other parameter registers 924 and 928. Data eventpoint module 900 also includes a control register 914, eventpoint decode and control logic 910 and the necessary interfaces required for a generalized data eventpoint architecture in accordance with the present invention. The data eventpoint control register 914 is one of a plurality of byte-wide control registers, with one byte-wide register assigned for each data eventpoint. The data eventpoint control registers for up to three data eventpoints may be suitably stored in an SPR file made up of a 32-bit register as shown in the tables below: SP/PE0 DEPCTL0 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 R P P P R D D D S P T DEP2 S P T DEP1 S P T DEP0 e E E E e M A M 2 2 2 1 1 1 0 0 0 s D D D s A M A e E E E e S S S r P P P r e e e v 2 1 0 v 1 1 1 e e 2 1 0 d d PEx DEPCTL0 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 Reserved P Reserved D Reserved S P T DEP0 E M 0 0 0 D A E S P e 0 1 0 In the above tables, DEPx Specifies how DEPxRO, DEPxR1 and DEPxR2 are used for detecting data events and generating corresponding actions. Sx Sx = 0: Do not output debug interrupt on match event. Sx = 1: Debug interrupt is driven by control logic on match event. Px Px = 0: Pass InTrigger signal to OutTrigger signal (except when generating an OutTrigger from control logic). Px = 1: Always generate OutTrigger from control logic. Tx Tx=0: InTriggerFF always set to ‘1’ during monitoring. Tx=1: InTriggerFF set by InTrigger signal (previous EP's OutTrigger signal). DMASelx Select DMA Lane address for DEPx. For DMA synchronization DEP control codes. DMASelx = 0: Monitor DMA Lane 0 address. DMASelx = 1: Monitor DMA Lane 1 address. PEDEPx For SP/PE0, these bits indicate whether the DEP is configured to monitor SP or PE0 addresses. PEDEPx = 0: Monitor SP data addresses. PEDEPx = 1: Monitor PE0 data addresses. It is noted that in the exemplary implementation specified by the control register definition above, additional data eventpoints can be added by using another data eventpoint control register for each group of up to three data eventpoints. The control register 914 represents one of the byte fields from the DEPCTL0 and passes the 8-bits of control information on signal lines 929 to the decode and control logic 910. Further details for the three other data eventpoint registers 924 (DEPxR0), 928 (DEPxR1), and 16-bit half-word registers 916 and 918, DEPxR2.H1 and DEPxR2.H0 respectively, are shown in the tables below: DEPxR0 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 parameter value DEPxR1 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 parameter value DEPxR2 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 DEPxR2.H1 DEPxR2.H0 The register DEPxR0 924 holds a programmer-specified value, loaded over the SPR bus 917, which consists of address, data, and controls, that is to be compared with the bus/signals 921 as selected by the control register 914 DEPCTLz. By encoded bit field. In the data eventpoint module 900 of FIG. 9, multiplexer 923 provides a mechanism to select either the load effective address (LEA) or the store effective address (SEA) as the value on the multiplexer output 921 to be compared. This mechanism provides the capability to trigger an event on a match of a load data effective address or a store data effective address. The register DEPxR1 928 holds a programmer specified data value, loaded over the SPR bus 917, which consists of address, data, and controls, that is to be compared with either a selected data value 975 that represents a masked 950 LDATA or SDATA bus by use of the DEPxR2.H1 and DEPxR2H0 or one of the bus/signals 971 as selected by the control register 914 DEPx encoded bit field. It is noted that the load data (LDATA) bus 977 and store data (SDATA) bus 979 are latched data values stored in a hidden scratch pad register due to the execution pipeline in use for the ManArray processor. The DEPxR2.H0 count register 918 can also act as an eventpoint counter which indicates a count of 1, a count of 0, or if the count is greater than 1. The decode and control logic 910 operation is described in detail in operation tables 1010, 1015, 1020, 1030, 1040, 1050, 1060, 1070, 1080, 1090, and 1095 shown in FIGS. 10A-10J. These tables are constructed in the same manner as the instruction eventpoint logic descriptions of FIGS. 6A-6G. The control value column 1012 of each figure provides a description of the logic operation for the programmed control value also indicated in the same column. Matches with the load effective address (LEA), the store effective address (SEA), load data (LDATA), and/or store data (SDATA) of the data memory accesses are enumerated as options for the data eventpoint logic. Background DMA operations, described in greater detail below, are also presented with use of data eventpoints in FIGS. 10I and 10J. It is appreciated that other eventpoint operations are easily achieved for numerous purposes using this architectural and programming approach for eventpoints. When a data eventpoint is detected, one option selected by the eventpoint logic is to cause an EP interrupt 947 that changes the program flow to a debug interrupt routine useful for analysis and problem solving. The EPxOut signal 976 of FIG. 9 is asserted in data eventpoint control modes when the eventpoint counter is being used as a semaphore and an address match has occurred with a non-zero count present. For example, this approach is used for DMA data flow control by connecting the signal to inputs in the DMA controller which cause semaphore increments. Each data event point provides an EPxOut signal to a controlling event action module such as a DMA controller. The use of eventpoints in DMA operations is discussed further after eventpoint chaining and eventpoint status are discussed. Eventpoint Chaining FIG. 11 depicts an eventpoint chaining apparatus 1100 which may be advantageously used in an exemplary implementation of the ManArray architecture similar to the system shown in FIG. 1 is discussed further below. The eventpoint chaining apparatus 1100 uses the OutTrigger (OutTrig) signal, for example signal 1101 from an eventpoint module 1104 as an input InTrigger (InTrig) signal 1103 for the next eventpoint module 1102. Eventpoint modules 1102-1118 are linked together in a circular chain. The chaining of eventpoints, in reference to FIGS. 5 and 9, is accomplished through the use of the OutTrigger signal 545 or 945 and the InTrigger signal 515 or 915. The OutTrigger signal 545 or 945 is selected by multiplexer 508 or 908 as controlled by control signal 543 or 943, when the OutTrigger path 941 is enabled and an eventpoint is discovered. Alternatively, the InTrigger signal 515 or 915 can be passed through the eventpoint module as selected by multiplexer 508 or 908 and controlled by control signal 543 or 943. The InTriggerFF (InTFF) latch 512 or 912, when enabled, captures the state of the InTrigger signal 515 or 915 which is sent to the decode and control logic 510 or 910 over line 527 or 927. The InTFF latch, 512 or 912, is cleared whenever A value is written to the control register field associated with its eventpoint, or An eventpoint match has occurred, or The eventpoint is disabled. The OutTrigger output 545 or 945 from an eventpoint module connects to the InTrigger input 515 or 915 of the assigned eventpoint module. FIG. 11 depicts an exemplary chaining with a mixture of six instruction eventpoints SP/PE0 IEP5-0 and three data eventpoints DEP2-0 in the SP/PE0, such as the SP/PE0 101. It is noted that the specific order of the chaining shown represents one choice as used in an exemplary implementation of a 2×2 ManArray processor. It is further noted that while the chaining of data eventpoints between PE is not shown and the use of multiple data eventpoints in each PE is not shown in FIG. 11, these options are not precluded by the architecture of the present invention. The OutTrigger (OutTrig) from each eventpoint module is connected to the InTrigger (InTrig) of the connecting eventpoint module. Eventpoint Status Eventpoints may be programmed with various control options. The purpose of some of these options is simply to detect when a particular event or sequence of events has occurred. The EPSTAT register is used to capture event occurrence for those events which generate an EP interrupt so that if multiple eventpoint interrupts are being tracked, they may be distinguished. Suitable EPSTAT registers and the chosen definition for the status bits for the exemplary 2×2 ManArray implementation are shown in the following format tables for a 32-bit example. Since the ManArray processor merges the SP array controller with PE0 of the PE array, the EPSTAT register data eventpoints are shared between the SP and the PE0. In other implementations, this organization may not exist, but the concepts and use of the eventpoints and the EPSTAT registers still applies. SP/PE0 EPSTAT (Read-only, SP SPR) Reset Value = 0x00000000 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 Reserved I I I I I I Reserved D D D E E E E E E E E E V V V V V V V V V 5 4 3 3 1 0 2 1 0 PE EPSTAT (Read-only, PE SPR) Reset Value = 0x00000000 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 Reserved D E V 0 DEVx This bit is set when a match event generates an EP interrupt for Data Event Point ‘x’. (Not all control codes that may be programmed cause an interrupt to be generated on a match event, and for these cases the DEVx bits are not set). 0 = event has not occurred 1 = event has occurred IEVx This bit is set when a match event generates an EP interrupt for Instruction Event Point ‘x’. (Not all control codes that may be programmed cause an interrupt to be generated on a match event, and for these cases the IEVx bits are not set). 0 = event has not occurred 1 = event has occurred FIG. 11 further illustrates that for each eventpoint module 1102-1123 an EP Interrupt can be generated. All instruction 1126 and data 1128 eventpoint EP interrupts are logically ORed together by OR gate 1125 to provide the eventpoint interrupt signal to the SP interrupt control unit 1130. Within the SP and PEs, the EPSTAT registers are used to store event status from SP or PE resident event point control logic. The EP status saved in the EPSTAT registers indicates when an event point has matched its event criteria and generated an EP interrupt. A read from this register returns the status while a write to this register with any data clears the status flags. These bits are also cleared at reset. It is noted that other formats and bit definitions are not precluded. For example, status indication on any match event can be provided in addition to the above noted match and EP interrupt event status. The SP/PE0 and each of the other PEs contains an EPSTAT register that is visible in their own SP and PE SPR address spaces. In the SP/PE0, the SP EPSTAT register can be read by use of the LSPR.S instruction illustrated in FIGS. 2A and 2B. In the PEs, the PE EPSTAT register can be read by use of the LSPR.P instruction also illustrated in FIGS. 2A and 2B. In the exemplary implementation of FIG. 1, each PE's EPSTAT register contains only a single status bit that indicates if the PE generated a match event which caused an EP interrupt. In this illustrative example, each PE, such as one of the PEs 151, 153 or 155 of FIG. 1, supports one data eventpoint requiring only three parameter registers and one control register. Specifically, PE event status may be read using an LSPR.P instruction along with SPRECV instructions to retrieve each PE's status to the SP register file. The SPRECV instruction causes the specified SP target register to receive data from PE0's cluster switch input port. Even though the exemplary implementation describes only a single eventpoint per PE, multiple data eventpoints per PE are not precluded and may be readily implemented utilizing the present teachings. In the SP and depending upon the implementation and with two eventpoint control register specifications, up to eight instruction eventpoints can be set up. It will be recognized that additional eventpoints can be added as desired. The eventpoints can be shared and combinations of capabilities provided. For example, '1 in the SP, two nested EP loops with two background DMA operations with two instruction and two data debug eventpoints can be programmed. In addition, highly advantageous capabilities, as described in the control value and logic description of FIGS. 6A-6F and 10A-10G, are provided to the general programmer. Eventpoint Background DMA One of the many unique uses of the present eventpoint architecture is its use to initiate and control background direct memory access (DMA) operations to efficiently move data while normal processing continues. For example, the managing of a data buffer 1200, such as is shown in FIG. 12A, where a local memory data segment M is split into two buffer portions, a Buf1 1202 and a Buf2 1204. In a typical application, such as processing an MPEG compressed bit-stream, it is desirable to achieve efficient processing of the data without using a lot of performance-limiting memory management steps. The eventpoint architecture of the present invention advantageously achieves this goal as discussed further below. In one approach using data-access triggered DMA, the following requirements are assumed: A stream of variable-length data elements is consumed from a circular buffer in memory which is of length BUFSIZE words. The elements are processed as they are read. A new word is loaded into the buffer at intermittent intervals based on the size of the variable length code (vlc). Conditional execution is used to perform the LOAD of a new word, and a load does not occur on every pass through the “get new vlc” function. Thus, there is not a direct correlation between fetching of an instruction address and consumption of data. It is desired to trigger a background refill operation after N data accesses from the buffer, not N instruction fetches from a particular address. In this case, the background operation is a DMA operation to refill a buffer. It is necessary to prevent overrun of the buffer, in other words, to prevent DMA writes on top of unprocessed data. It is necessary to prevent underrun, in other words, to prevent the case where the processor reads ahead of data. It is assumed a ping-pong buffer is accessed in a circular fashion by the SP code. Buffer halves are labeled Buf1 and Buf2, each of length N. A DMA transfer is set up to move N words of data at a time to a circular buffer of size 2N, that is the core transfer count (CTC) of data to be transferred to the core is N, but the buffer size of the circular transfer is 2N. The DMA transfer uses a semaphore to indicate when it is allowed to fill a buffer. Initially, the DMA semaphore is set to 2, indicating it can fill both buffers. Each time the DMA unit decrements CTC to zero, i.e., transfers N data values, it also will decrement and check the semaphore. If the semaphore is non-zero after the decrement, the transfer reloads CTC with N and continues the transfer, filling the other half of the buffer (Buf2). If the semaphore has been decremented to zero, then the DMA waits until it is non-zero to reload CTC and continue with another transfer. Whenever N data elements are transferred (CTC reaches zero), the DMA sends a signal to an eventpoint (EP) module which causes it to increment its count value. Whenever the SP accesses a data address (via a LOAD instruction in this case) that has been programmed into the EP block, the EP sends a signal to the DMA unit which causes its semaphore to increment. If the EP count value is zero, then the SP will optionally stall to wait for data to arrive. If the EP count is non-zero, the EP count is decremented and the SP continues. If both the DMA and SP access the counter simultaneously and the count remains the same, the SP is allowed to continue. Since a Data EP can only specify up to 2 address parameters in the example implementation, the count value can be up to two. Signaling from DMA to EP block is done by each DMA Lane Controller which routes its CTCzero interrupt signal to 1 of the IEP and 1 of the DEP modules of the SP. In another approach, FIG. 12B contains an outline of a simple program routine 1220 set up as a data dependent loop to process an unknown quantity of data elements. The data processing is to continue until an end-of-data code is decoded from the received encoded bit-stream stored in the buffers prior to processing. Initially, a DMA for Buf1 is started, after which the program routine starts at address L0. The routine 1220 then loops until an end-of-data code is decoded. The routine accesses data from the memory buffer by use of a load modulo index type of instruction that begins addressing at the address A, the start address of FIG. 12A, and automatically wraps the address around, at the end of Buf2, to the beginning of Buf1, address A. The three eventpoints used are shown in table 1240 of FIG. 12C. The first eventpoint is an instruction event point that is chained to the two data eventpoints, DEP0 and DEP1. The IEP0 eventpoint, control value OPT00001 670 of FIG. 6F, is setup with IEPOR0=not used, IEPOR1=XL, address of DMA-not-complete-do-something-else program, and IEPOR2.H0=IEPOR2.H1=2, indicating at the start that either Buf1 or Buf2 has data. The IEP0 counter is set up by its decode and control logic to increment the counter upon receiving a DMA transfer complete signal 509 (FIG. 5). The counter decrements whenever an InTrigger event occurs. The instruction eventpoint, when InTrigger occurs and the count is a one, causes the vector address X1 to be loaded into the PC thereby changing the program flow to the DMA-not-complete-do-something-else routine. In normal operation, the count is incremented by the DMA transfer complete signal prior to receiving an InTrigger signal and the IEP0 eventpoint will not occur. If the DMA is held up and the DMA operation is not complete, only then will the program reach the special routine. The other two background DMA data eventpoints are set up for interfacing with the system DMA unit. The first one uses data eventpoint0 (DEP0) with DEPOR0=A, the Start address of Buf1, DEPOR1=C, the start of Buf2 address, and DEPOR2.H0=0, DEPOR2.H1=O, Buf2 empty state. The second one uses data eventpoint1 (DEP1) with DEP1R0=C, the start of Buf2 address, DEP1R1=A, the start of Buf1 address, and DEP1R2.H0=1, DEP1R2.H1=0, Buf1 full state. It is further assumed for this example, that the size of Buf1 is equal the size of Buf2 (FIG. 12A), and the DMA unit is set up previous to the program routine to transfer a buffer size of N beginning at a start address that is passed to the DMA hardware when the background DMA is initiated. The sequence of events is as follows assuming Buf1 is fully loaded with the initial data at the start of the program. The program routine begins processing data in Buf1, which on the first access at address A the DEP0 eventpoint is detected which initiates a DMA operation to load data into Buf2 beginning at address C, which address value is passed to the DMA hardware unit over the EP1Bus 981. When DEP0 is activated, the count in IEP1R2.H0 reloads a 0 indicating that Buf2 is empty. The program routine continues processing the data in Buf1 while the DMA unit in the background independently loads the next set of data elements into Buf2. At the end of the DMA transfer of data to Buf2, the DMA unit generates a DMA complete signal which increments the Buf2 count in DEP0R2.H0 to 1 indicating Buf2 is now full and processing can proceed. Meanwhile, the processing of Buf1 data has continued until it reaches the first data element in Buf2 at address C and DEP1 eventpoint is triggered reloading DEP1's count DEP1R2.H0 to zero indicating Buf1 is now empty and DEP1R1=A is passed to the DMA unit over the EP0Bus 981. The DMA unit now initiates the background loading of Buf1 while the program is allowed to continue with the processing of Buf2 data. The program routine continues processing the two buffers until the end-of-data code is decoded. If the program ever tries to access data from Buf1 at address A, or Buf2 at address C, and the DMA transfer has not completed for that buffer, instruction eventpoint IEP0 is triggered, indicating the background DMA has not completed operation. This concept is extended by allowing address masking in the address compare, for example, by using a single address with a mask register, and then supporting multiple address matching for buffer sizes that are a power of 2. Since masking is already allowed for the data compares, this approach may be readily implemented. Address masking is also useful for trapping when access to specified regions of memory by either instruction fetch or data fetch is attempted. The generalized eventpoint architecture shown in FIGS. 5 and 9 and discussed above in detail includes the advantageous capabilities highlighted in the partial list that follows: auto looping, auto looping with loop skip if count is zero, auto looping where an InTrigger signal can be used to exit or skip the loop, background DMA, initiating a timer from some data or instruction eventpoint, and cache pre-fetch operation. While the present invention has been disclosed in the context of various aspects of presently preferred embodiments, it will be recognized that the invention may be suitably applied to other environments and applications consistent with the claims which follow. | <SOH> BACKGROUND OF THE INVENTION <EOH>A processor event or p-event may be defined as some change of state that it is desirable to recognize. The acknowledgement of a processor event may be termed a processor action or p-action. The purpose of the event-action mechanism, or eventpoint, is to synchronize various actions with specific program and/or data flow events within the processor. Examples of eventpoints which may be encountered include reaching a specified instruction address, finding a specific data value during a memory transfer, noting the occurrence of a particular change in the arithmetic condition flags, accessing a particular memory location, etc. Eventpoints can also include a linked sequence of individual eventpoints, termed chaining, such as finding a specific data value after reaching a specified instruction address, or reaching a second specified instruction address after reaching a first specified instruction address. The p-actions can include changing the sequential flow of instructions, i.e., vectoring to a new address, causing an interrupt, logging or counting an event, time stamping an event, initiating background operations such as direct memory access (DMA), caching prefetch operations, or the like. In previous approaches, each p-event and its consequent p-action typically was treated uniquely and separately from other specific event-actions in order to solve some special problem. One of the many new contributions the architecture of the present invention provides is a generalized eventpoint mechanism. A requirement of the traditional sequential model of computation is that the processor efficiently handle the programming constructs that affect the sequential flow of instructions to be executed on the processor. In the prior art, one of these programming constructs is an auto-looping mechanism, which is found on many digital signal processors (DSPs). Auto-looping is employed to change the program flow for repetitive loops without the need for branch instructions, thereby improving the performance of programs that use loops frequently. Nested loops have also been supported in the prior art. It has also been found imperative that a processor support facilities to debug a program. In the prior art, the capability of setting breakpoints on instructions, data, or addresses that cause a branch to a specified target address or cause an interrupt has been developed. The interrupt or debug branch directs the program flow to a special program that provides debug operations to aid the programmer in developing their software. In another example, it has also been found imperative that a processor support facilities for initiating a DMA operation to occur in the background of normal program execution. In the past, the background DMA capability was typically initiated by specific DMA instructions or instructions specialized for DMA by nature of the side effect that they cause. Consequently, auto-looping, background DMA operation, debug breakpoint capability, and other unique p-events and their consequent p-actions, represent approaches that have been considered separately in the prior art. The present invention generalizes these functions and provides additional unique capabilities that arise due to the generalization of the various p-events and p-actions in a common architecture thereby providing a common design and program approach to the development and use of all of these types of functions. | <SOH> SUMMARY OF THE PRESENT INVENTION <EOH>The present invention addresses the need to provide a processor with a generalized p-event and p-action architecture which is scalable for use in a very long instruction word (VLIW) array processor, such as the ManArray processor. In one aspect of the invention, generalized p-event detection facilities are provided by use of a compare performed to discover if an instruction address, a data memory address, an instruction, a data value, arithmetic-condition flags, and/or other processor change of state eventpoint has occurred. In another aspect of this invention, generalized p-action facilities are provided to cause a change in the program flow by loading the program counter with a new instruction address, generating an interrupt, generating a log, counting the p-event, passing a parameter, etc. The generalized facilities may be advantageously defined in the eventpoint architecture as consisting of a control register and three eventpoint parameters: 1) a register to compare against, 2) a register containing a second compare parameter, vector address, or parameter to be passed, and 3) a count or mask register. Based upon this generalized eventpoint architecture, new capabilities are supported that extend beyond typical prior art capabilities. For example, auto-looping with capabilities to branch out of a nested auto-loop upon detection of a specified condition, background DMA facilities, and the ability to link a chain of p-events together for debug purposes, among others are all new capabilities easily obtained by use of this invention. A more complete understanding of the present invention, as well as other features and advantages of the invention, will be apparent from the following Detailed Description and the accompanying drawings. | 20040225 | 20060606 | 20050609 | 91220.0 | 0 | KIM, KENNETH S | CASCADED EVENT DETECTION MODULES FOR GENERATING COMBINED EVENTS INTERRUPT FOR PROCESSOR ACTION | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,786,798 | ACCEPTED | Space process to prevent the reverse tunneling in split gate flash | A split gate flash memory cell structure is disclosed for prevention of reverse tunneling. A gate insulator layer is formed over a semiconductor surface and a floating gate is disposed over the gate insulator layer. A floating gate insulator layer is disposed over the floating gate and sidewall insulator spacers are disposed along bottom portions of the floating gate sidewall adjacent to said gate insulator layer. The sidewall insulator spacers are formed from a spacer insulator layer that had been deposited in a manner that constitutes a minimal expenditure of an available thermal budget and etching processes used in fashioning the sidewall insulator spacers etch the spacer insulator layer faster than the gate insulator layer and the floating gate insulator layer. An intergate insulator layer is disposed over exposed portions of the gate insulator layer, the floating gate, the floating gate insulator layer and the sidewall insulator spacers. A conductive control gate is disposed over the intergate insulator layer, covering about half of the floating gate. | 1. A split gate flash memory cell structure for prevent of reverse tunneling comprising: a semiconductor region within a substrate extending to a surface; a gate insulator layer formed over said semiconductor surface; a conductor floating gate disposed over said gate insulator layer a floating gate insulator layer disposed over said floating gate adjacent to said gate insulator layer, where etching processes used to fashion said sidewall insulator spacers from a spacer insulator layer, etch said spacer insulator layer faster than said gate insulator layer and said floating gate insulator layer; an integrate insulator layer disposed over exposed portions of said gate insulator layer, said floating gate, said floating gate insulator layer and said sidewall insulator spacers; a conductive control gate disposed over said intergate insulator layer and covering about half of said floating gate. 2. The structure of claim 1 wherein said semiconductor region is a silicon region. 3. The structure of claim 1 wherein said substrate is a silicon containing substrate. 4. The structure of claim 1 wherein said gate insulator layer is a thermally grown oxide layer grown to a thickness of about 50 to 200 angstroms. 5. The structure of claim 1 wherein said conductive floating gate is composed of polysilicon. 6. The structure of claim 1 wherein said floating gate insulator layer is a grown polysilicon oxide layer grown to a thickness of about 800 to 2000 Angstroms. 7. The structure of claim 1 wherein said spacer insulator is an oxide layer. 8. The structure of claim 1 wherein said spacer insulator layer is a PECVD oxide layer. 9. The structure of claim 1 wherein said spacer insulator layer is a deposited oxide layer, said gate insulator layer is a thermal oxide layer and said floating gate insulator layer is a polysilicon oxide layer. 10. The structure of claim 1 wherein said etching processes used to fashion said sidewall insulator spacers from said spacer insulator layer are an anisotropic dry etch leaving some of said spacer insulator layer everywhere followed by a wet etch leaving only said sidewall insulator spacers. 11. The structure of claim 1 wherein said intergate insulator layer is an oxide layer. 12. The structure of claim 1 wherein said conductive control gate is composed of polysilicon. 13. A method for forming a split gate flash memory cell that prevents reverse tunneling comprising: providing a semiconductor region within a substrate extending to a surface; forming a gate insulator layer over said semiconductor surface; forming a conductive floating gate disposed over said gate insulator layer with a glaoting gate insulator layer disposed over said floating gate; depositing a spacer insulator layer over exposed portions of said gate insulator layer, said floating gate and said floating gate insulator layer; etching said spacer insulator layer to fashion sidewall insulator spacers along bottom portion of said floating gate sidewall adjacent to said gate insulator layer; forming an intergate insulator layer disposed over exposed portions of said gate insulator layer, said floating gate, said floating gate insulator layer and said sidewall insulator spacers; forming a conductive control gate disposed over said intergate insulator layer and covering about half of said floating gate. 14. The method of claim 13 wherein said semiconductor region is a silicon region. 15. The method of claim 13 wherein said substrate is a silicon containing substrate. 16. The method of claim 13 wherein said conductive floating gate is composed of polysilicon. 17. The method of claim 134 wherein said conductive floating gate is composed of polysilicon. 18. The method of claim 13 wherein said floating gate insulator layer is a thermally grown polysilicon oxide layer. 19. The method of claim 13 wherein said floating gates and floating gate insulator layer are formed by depositing a polysilicon layer over said gate insulator layer, depositing a hard mask layer over said polysilicon layer, patterning and etching said hard mask to expose a floating gate pattern on said polysilicon layer, growing a thermal polysilicon oxide over said exposed polysilicon layer to form said floating gate insulator layer, removing remaining said hard mask layer and etching said polysilicon layer stopping at said gate insulator layer. 20. The method of claim 13 wherein said floating gates and floating gate insulator layer are formed by depositing a polysilicon layer over said gate insulator layer, depositing a hard mask layer over said polysilicon layer, patterning and etching said hard mask to expose a floating gate pattern on said polysilicon layer, growing a thermal polysilicon oxide over said exposed polysilicon layer to form said floating gate insulator layer, removing remaining said hard mask layer and etching polysilicon layer stopping at said gate insulator layer and wherein said hard mask layer is a nitride layer. 21. The method of claim 13 wherein said floating gates and floating gate insulator layer are formed by depositing a polysilicon layer over said gate insulator layer, depositing a hard mask layer over said polysilicon layer, patterning and etching said hard mask to expose a floating gate pattern on said polysilicon layer, growing a thermal polysilicon oxide over said exposed polysilicon layer to form said floating gate insulator layer, removing remaining said hard mask layer and etching polysilicon layer stopping at said gate insulator layer and wherein said patterning and etching of said hard mask layer is accomplished by forming a photoresist layer, patterning said photoresist layer and etching said hard mask layer stopping at the said polysilicon layer and removing said photoresist layer. 22. The method of claim 13 wherein said floating gates and floating gate insulator layer are formed by depositing a polysilicon layer over said gate insulator layer, depositing a hard mask layer over said polysilicon layer, patterning and etching said hard mask to expose a floating gate pattern on said polysilicon layer, growing a thermal polysilicon oxide over said exposed polysilicon layer to form said floating gate insulator layer, removing remaining said hard mask layer and etching polysilicon layer stopping at said gate insulator layer and wherein said growing of said thermal polysilicon oxide is performed at about 800° C.-1500° C. to a thickness of about 500-3000 Angstroms. 23. The method of claim 13 wherein said spacer insulator layer is an oxide layer. 24. The method of claim 13 wherein said spacer insulator layer is a deposited oxide layer, said gate insulator layer is a thermal oxide layer and said floating gate insulator layer is a polysilicon oxide layer. 25. The method of claim 13 wherein said etching processes used to fashion said sidewall insulator spacers from said spacer insulator layer are an anisotropic dry etch leaving some of said spacer insulator layer everywhere followed by a wet etch leaving only said sidewall insulator spacers layer. 26. The method of claim 13 wherein said intergate insulator layer is an oxide layer. 27. The structure of claim 13 wherein said conductive control gate is composed of polysilicon. | BACKGROUND OF THE INVENTION (1) Field of the Invention The present invention relates generally to semiconductor integrated circuit technology and more particularly to memory cells used in split gate flash EEPROMs (Electrically Erasable Programmable Read Only Memory). (2) Description of Prior Art In programming and erase operations used in split-gate flash memory cells, electrons are transferred into (programming) or out of (erasing) floating gates. As is well known in the art, this transfer of electrons is accomplished by tunneling through thin insulator layers separating the three basic components of a split-gate memory cell, namely: substrate, floating gate and control gate. The programming and erase operations are affected by the passage of electrons trough the intervening thin insulator layers by application of different voltage levels to the control gate and source and drain of the cell. It is important that no extraneous current paths exist that could interfere with the charge transfers of the programming and erasing operations. Such extraneous current paths can seriously impact device yield and reliability and steps need be taken to prevent the occurrence of extraneous current paths. A common and persistent defect found in conventional split gate flash cells is shown in FIGS. 1a and 1b. This defect is appropriately denoted “poly tip” and it is what gives rise to an extraneous current that is commonly called “reverse tunneling”. Shown in FIG. 1a is a typical structure for a conventional split gate flash cell. A floating gate, 6, is disposed over a gate oxide layer, 4, which had been formed over a silicon region, 2. A thermally grown poly oxide layer, 10, is disposed over the floating gate and an intergate insulator layer, 8, is deposited over the poly oxide layer, the floating gate sidewalls and the exposed gate oxide layer. A magnified view of the region where the poly tip occurs is shown in FIG. 1b. An etching of the poly layer and a wet dip, process steps used to form the floating gate, can give rise to an undercut, 14, of the floating gate. The undercut is replicated on the deposited intergate insulator layer, as shown in FIG. 1b. Another method of separating the control gate from the floating gate is to grow an oxide layer over the floating gate sidewalls, but the replication of the undercut would also occur in this method. In either method, when forming the control gate, 12, the undercut shape is filled with conductive material giving rise to a poly tip, 16. Since the poly tip is a feature that causes reverse tunneling, it is important to devise split gate structures and processing methods that do not produce a poly tip. Prior art methods exist that produce structures that do not contain a poly tip or in which the affect of the poly tip is alleviated. This is usually accomplished by increasing the spacing between the control gate and the bottom of the floating gate, which can be done in various ways, such as, tapering the sides of the floating gate or by forming insulating barriers and spacers. These methods invariably involve extra processing steps and adding processing steps is inherently undesirable because of increased cost and decreased reliability. Moreover other problems could be introduced. For example, silicon nitride spacers could be used to alleviate the poly tip problem, but such spacers could give rise to undesirable excessive stress and the high nitride deposition temperature strains the present generation thermal budget limitations. Chiang et al. U.S. Pat. No. 6,617,638 discloses a method of forming a split-gate flash memory cell with a tapered floating gate. The negatively tapered walls provide a geometry better suited for forming thicker spacers around the floating gate. Hsieh et al. U.S. Pat. No. 6,465,841 teaches a method to fabricate a split-gate flash memory cell with nitride spacers. U.S. Pat. No. 6,380,030 to Chen et al. shows an implant method for forming a silicon nitride spacer. U.S. Pat. No. 6,031,264 to Chien et al. discloses a nitride spacer for flash EPROM. SUMMARY OF THE INVENTION It is a primary objective of the invention to provide a method of forming split gate flash memory cells in which reverse tunneling does not occur. It is a further primary objective of the invention to provide a method of forming split gate flash memory cells in which poly tips do not occur. It is yet a further primary objective of the invention to provide a method of forming split gate memory cells in which reverse tunneling does not occur, which does not introduce any other problems and which is readily compatible with thermal budget limitations. It is another primary objective of the invention to provide a structure for split gate memory flash cells that can be fabricated so that reverse tunneling does not occur. It is yet another primary objective of the invention to provide a structure that can be fabricated so that poly tips do not occur. It is further yet another primary objective of the invention to provide a split gate flash memory cell structure that can be fabricated so that reverse tunneling does not occur, which does not introduce any other problems and which is compatible with thermal budget limitations. These objectives are attained in the invention by the formation of an oxide spacer utilizing a two-step etching procedure. A deposited oxide layer is first subjected to an anisotropic dry etch which is followed by a wet etch to form a sidewall oxide spacer on the floating gate. The deposited oxide layer must have a higher wet etch rate than the thermal floating gate oxide and the thermal poly oxide. This oxide spacer prevents the formation of poly tips and consequently there is no reverse tunneling is observed. No other problems are introduced and the oxide deposition can be performed at moderate temperatures so the process is suitable to thermal budget limitations. A split gate flash memory cell structure is disclosed for prevention of reverse tunneling. A gate insulator layer is formed over a semiconductor surface and a floating gate is disposed over the gate insulator layer. A floating gate insulator layer is disposed over the floating gate and sidewall insulator spacers are disposed along bottom portions of the floating gate sidewall adjacent to said gate insulator layer. The sidewall insulator spacers are formed from a spacer insulator layer that had been deposited in a manner that constitutes a minimal expenditure of an available thermal budget and etching processes used in fashioning the sidewall insulator spacers etch the spacer insulator layer faster than the gate insulator layer and the floating gate insulator layer. An intergate insulator layer is disposed over exposed portions of the gate insulator layer, the floating gate, the floating gate insulator layer and the sidewall insulator spacers. A conductive control gate is disposed over the intergate insulator layer, covering about half of the floating gate. BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawing forming a material part of this description, there is shown: FIGS. 1a and 1b show how a poly tip is formed in a traditional split gate flash memory cell structure. FIGS. 2-11 show a method for forming a split gate flash memory cell according to preferred embodiments of the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the invention are well described with the aid of FIGS. 2-11. Methods for forming split gate flash memory cell structures in which poly tips do not form are advantageously described with reference to FIGS. 2-11, in which cross-sectional views of the structure are shown at various stages of the fabrication process. FIG. 2 shows the structure prior to patterning and forming floating gates. A gate insulator layer, 4, is formed over a semiconductor region, 2, of a substrate. Preferably, the gate insulator layer is a tunneling oxide layer grown to a thickness of about 50 to 200 Angstroms over the semiconductor region, which preferably is a silicon region of a silicon substrate. A first conductive layer, 18, which preferably is a deposited polysilicon layer, is formed over the first insulator layer. The first conductive layer will be utilized to form floating gates, 28, over which a floating gate insulating layer, 26, is disposed. In most preferred embodiments of the invention the formation of the floating gate and floating gate insulating layer is accomplished by first forming a hard mask insulator layer, 20, which preferably is a silicon nitride layer. Patterning of the hard mask insulator layer to achieve a floating gate pattern can preferably be accomplished by forming a photoresist layer, 22, patterning the photoresist layer and etching the hard mask insulator layer stopping at the first conductive layer and removing the photoresist layer. The structure is now as shown in FIG. 3. The floating gate insulator layer 26 is then formed as shown in FIG. 4. Preferably the floating gate insulator layer is formed by a wet oxidation of the polysilicon first conductive layer, 18, at a temperature in the range of about 800° C.-1000° C. to a thickness of about 800-2000 Angstroms. Removal of the remaining hard mask layer results in the structure shown in FIG. 5. Formation of the floating gate, 28, can now be completed by etching the first conductive layer using the floating gate insulator layer as a hard mask, which results in the structure shown in FIG. 6. A spacer insulator layer, 30, is now formed as shown in FIG. 7, from which spacers, 34, conforming to preferred embodiments of the invention are to be fashioned. Preferably the spacer insulator layer is formed by a low temperature, i.e. less than about 500° C., deposition of oxide to a depth of about 800 to 1000 Angstroms, using processes such as PECVD and LPCVD that enable such low deposition temperatures. A key point of the invention is that deposition of the spacer insulator layer be performed using materials and deposition processes that can be accomplished at temperatures low enough so as not to strain the thermal budget. It is also crucial to the invention that the wet etch rate of the spacer insulator layer be larger than the wet etch rate of the gate insulator layer and of the floating gate insulator layer. In preferred embodiments of the invention in which the gate insulator layer is a thermally grown oxide and the floating gate insulator layer is a thermally grown poly oxide, the difference in etch rate is realized when the spacer insulator layer is a deposited oxide layer such as a PECVD or a LPCVD oxide layer. Wet etch rates of PECVD and LPCVD oxides are significantly larger than wet etch rates of thermal oxides. A major advantage of deposited oxide films such as PECVD or LPCVD oxide films is that deposition temperatures can be less than 500° C. so that these processes hardly impact the thermal budget. Traditional silicon nitride spacers used to prevent reverse tunneling require deposition temperatures in excess of about 700° C., which constitutes a significantly higher thermal budget expenditure. In addition, nitride spacers can introduce excessive stress, which does not occur with an oxide spacer. Forming spacers from the spacer insulator layer according to the invention involves a two-stage etching process. First an anisotropic dry etch is performed to reduce the spacer insulator layer thickness to achieve a profile, 32, as shown in FIG. 8. This is a partial etch, the spacer insulator layer should not be entirely removed anywhere in this first stage of the etch process. A second stage wet etch follows to form sidewall insulator spacers, 34, on the floating gate, 28. The reason for the requirement of a higher wet etch rate for the spacer insulator layer than for the gate insulator layer and for the floating gate insulator layer is apparent. Otherwise the wet etch could reduce the gate insulator layer and the floating gate insulator layer, which would be detrimental. Next a blanket interpoly insulator layer, 36, which preferably is an oxide layer, is deposited. This is followed by deposition and patterning of a control gate, 38, that is disposed over the interpoly insulator layer and, as shown in FIG. 11, is above about half of the floating gate. Poly tips do not occur for spacers fabricated according to the invention and reverse currents are not observed. While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>(1) Field of the Invention The present invention relates generally to semiconductor integrated circuit technology and more particularly to memory cells used in split gate flash EEPROMs (Electrically Erasable Programmable Read Only Memory). (2) Description of Prior Art In programming and erase operations used in split-gate flash memory cells, electrons are transferred into (programming) or out of (erasing) floating gates. As is well known in the art, this transfer of electrons is accomplished by tunneling through thin insulator layers separating the three basic components of a split-gate memory cell, namely: substrate, floating gate and control gate. The programming and erase operations are affected by the passage of electrons trough the intervening thin insulator layers by application of different voltage levels to the control gate and source and drain of the cell. It is important that no extraneous current paths exist that could interfere with the charge transfers of the programming and erasing operations. Such extraneous current paths can seriously impact device yield and reliability and steps need be taken to prevent the occurrence of extraneous current paths. A common and persistent defect found in conventional split gate flash cells is shown in FIGS. 1 a and 1 b . This defect is appropriately denoted “poly tip” and it is what gives rise to an extraneous current that is commonly called “reverse tunneling”. Shown in FIG. 1 a is a typical structure for a conventional split gate flash cell. A floating gate, 6 , is disposed over a gate oxide layer, 4 , which had been formed over a silicon region, 2 . A thermally grown poly oxide layer, 10 , is disposed over the floating gate and an intergate insulator layer, 8 , is deposited over the poly oxide layer, the floating gate sidewalls and the exposed gate oxide layer. A magnified view of the region where the poly tip occurs is shown in FIG. 1 b . An etching of the poly layer and a wet dip, process steps used to form the floating gate, can give rise to an undercut, 14 , of the floating gate. The undercut is replicated on the deposited intergate insulator layer, as shown in FIG. 1 b . Another method of separating the control gate from the floating gate is to grow an oxide layer over the floating gate sidewalls, but the replication of the undercut would also occur in this method. In either method, when forming the control gate, 12 , the undercut shape is filled with conductive material giving rise to a poly tip, 16 . Since the poly tip is a feature that causes reverse tunneling, it is important to devise split gate structures and processing methods that do not produce a poly tip. Prior art methods exist that produce structures that do not contain a poly tip or in which the affect of the poly tip is alleviated. This is usually accomplished by increasing the spacing between the control gate and the bottom of the floating gate, which can be done in various ways, such as, tapering the sides of the floating gate or by forming insulating barriers and spacers. These methods invariably involve extra processing steps and adding processing steps is inherently undesirable because of increased cost and decreased reliability. Moreover other problems could be introduced. For example, silicon nitride spacers could be used to alleviate the poly tip problem, but such spacers could give rise to undesirable excessive stress and the high nitride deposition temperature strains the present generation thermal budget limitations. Chiang et al. U.S. Pat. No. 6,617,638 discloses a method of forming a split-gate flash memory cell with a tapered floating gate. The negatively tapered walls provide a geometry better suited for forming thicker spacers around the floating gate. Hsieh et al. U.S. Pat. No. 6,465,841 teaches a method to fabricate a split-gate flash memory cell with nitride spacers. U.S. Pat. No. 6,380,030 to Chen et al. shows an implant method for forming a silicon nitride spacer. U.S. Pat. No. 6,031,264 to Chien et al. discloses a nitride spacer for flash EPROM. | <SOH> SUMMARY OF THE INVENTION <EOH>It is a primary objective of the invention to provide a method of forming split gate flash memory cells in which reverse tunneling does not occur. It is a further primary objective of the invention to provide a method of forming split gate flash memory cells in which poly tips do not occur. It is yet a further primary objective of the invention to provide a method of forming split gate memory cells in which reverse tunneling does not occur, which does not introduce any other problems and which is readily compatible with thermal budget limitations. It is another primary objective of the invention to provide a structure for split gate memory flash cells that can be fabricated so that reverse tunneling does not occur. It is yet another primary objective of the invention to provide a structure that can be fabricated so that poly tips do not occur. It is further yet another primary objective of the invention to provide a split gate flash memory cell structure that can be fabricated so that reverse tunneling does not occur, which does not introduce any other problems and which is compatible with thermal budget limitations. These objectives are attained in the invention by the formation of an oxide spacer utilizing a two-step etching procedure. A deposited oxide layer is first subjected to an anisotropic dry etch which is followed by a wet etch to form a sidewall oxide spacer on the floating gate. The deposited oxide layer must have a higher wet etch rate than the thermal floating gate oxide and the thermal poly oxide. This oxide spacer prevents the formation of poly tips and consequently there is no reverse tunneling is observed. No other problems are introduced and the oxide deposition can be performed at moderate temperatures so the process is suitable to thermal budget limitations. A split gate flash memory cell structure is disclosed for prevention of reverse tunneling. A gate insulator layer is formed over a semiconductor surface and a floating gate is disposed over the gate insulator layer. A floating gate insulator layer is disposed over the floating gate and sidewall insulator spacers are disposed along bottom portions of the floating gate sidewall adjacent to said gate insulator layer. The sidewall insulator spacers are formed from a spacer insulator layer that had been deposited in a manner that constitutes a minimal expenditure of an available thermal budget and etching processes used in fashioning the sidewall insulator spacers etch the spacer insulator layer faster than the gate insulator layer and the floating gate insulator layer. An intergate insulator layer is disposed over exposed portions of the gate insulator layer, the floating gate, the floating gate insulator layer and the sidewall insulator spacers. A conductive control gate is disposed over the intergate insulator layer, covering about half of the floating gate. | 20040225 | 20060418 | 20050825 | 98631.0 | 0 | TRAN, MAI HUONG C | SPACE PROCESS TO PREVENT THE REVERSE TUNNELING IN SPLIT GATE FLASH | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,786,954 | ACCEPTED | Drain seal for vehicle drain tube | A drain seal for connecting a drain tube to a support structure includes a molded unitary body having first and second moldingly joined portions, each formed of dissimilar durometer materials. The first portion is formed to sealingly join the body to a drain tube. The second portion is formed to mount the body in an aperture in a support structure. A bore extends completely through the body. | 1. A drain seal for use with a drain tube in a structure having an\ aperture, the drain seal comprising: a unitary, body having first and second moldingly joined portions; the first portion formed of a material having a first durometer, and carrying means for sealingly joining the body to a drain hose; the second portion formed of a material having a second durometer, and including means for mounting the body in an aperture in a structure; and a bore extending through the body from one end of the first portion of the body to an opposite end of the second portion of the body. 2. The drain seal of claim 1 further comprising: a chemical formed between the first and second portions. 3. The drain seal of claim 1 wherein the sealingly joining means comprises: at least one enlargement formed on the first portion. 4. The drain seal of claim 3 wherein the at least one enlargement has an outer diameter larger than an inner diameter of a drain tube. 5. The drain seal of claim 1 wherein the mounting means comprises: a rim having a diameter greater than an outer diameter of the first portion; and an annular recess formed between the rim and one end of the second portion, the recess receiving a surface in a structure. 6. The drain seal of claim 5 wherein: the first portion is joined to the second portion in a rim of the first portion. 7. The drain seal of claim 6 wherein the second portion further comprises: a drain end extending from the rim. 8. The drain seal of claim 7 wherein: the drain end has exterior surface tapering inward along two mutually opposed axes. 9. The drain seal of claim 7 further comprising: at least one slot formed in the drain end of the at least one slot fluidically coupled to the bore extending through the body. 10. The drain seal of claim 9 wherein the at least one slot comprises: a pair of intersecting slots formed in the drain end and fluidically coupled to the bore extending through the body. 11. The drain seal of claim 1 wherein: the first durometer of the material form in the first portion is higher than the second durometer of the material forming the second portion of the body. 12. The drain seal of claim 1 further comprising: an extension formed centrally on the first portion; the second portion surrounding and receiving the extension of the first portion. 13. A method for forming a drain seal for use with a drain tube and a structure having an aperture, the method comprising the steps of: molding a unitary body of first and second portions moldingly joined in a double shot molding operation; forming the first portion of a material having a first durometer; forming the second portion of a material having a second durometer; forming a bore extending through the body from one end of the first portion to an opposite end of the second portion. 14. The method of claim 13 further comprising the step of: forming the first durometer material with a higher durometer than the second durometer material. 15. The method of claim 13 further comprising the step of: forming a sealing means on the first portion of the body for joining the body to a drain tube. 16. The method of claim 13 further comprising the step of: forming a mounting means on the second portion of the body for mounting the body in an aperture in a structure. 17. The method of claim 16 wherein the step of forming the mounting means comprises the step of: forming an annular undercut between a drain end of the second portion of the body and an end surface of the body. 18. The method of claim 13 further comprising the steps of: forming enlarged ends for the first and second portions; and moldingly joining the enlarged ends. | BACKGROUND Sun roof assemblies are a common option in automotive vehicles. Such sun roof assemblies can be of the tilting and/or sliding type and have a panel mounted in a roof opening in the vehicle. The panel is moveably supported in a pair of longitudinally extending guide rails affixed to the vehicle roof A trough extends around the edge of the roof opening and collects water when the sun roof panel is open or if any water passes through the sealing structure typically employed with the sun roof panel. This drain trough is connected to one or more drain tubes which are typically run through the vehicle body side pillars. A lower end of the tube is open to allow water to be discharged from the vehicle. The bottom of the drain tube receives a drain seal which provides the dual functions of fixing one end of the drain tube to the vehicle body structure as well as providing a small, one way opening to allow water collected by the drain tube to exit the drain tube while at the same time preventing the entry of water or debris into the lower end of the drain tube. Prior drain seals have been formed of two separate elements which are joined together, typically by an adhesive. The two different elements have different shapes to serve different functions as well as being formed of different materials to again serve specific, different functions. One of the elements is formed of a softer durometer material to serve as a seal to the vehicle body structure. The other element is typically formed of a higher durometer material for fixed mounting of the drain seal to the drain tube. While effective, the prior art drain seals involve multiple parts which must be joined together. This increases the cost of the drain seal. It would be desirable to provide a drain seal for an automotive vehicle which can be manufactured at a lower cost while still providing all of the required functions of a drain seal. SUMMARY The inventive drain seal provides all the functions of a typical drain seal for a sun roof drain tube while, at the same time, having a unitary one piece construction thereby eliminating secondary assembly operations for lower manufacturing costs and improved reliability. The inventive drain seal mounts a drain hose to a vehicle support structure while allowing drainage of fluid from the attached drain hose. In one aspect, the drain seal includes a molded, unitary, monolithic body having first and second moldingly joined portions, the first portion formed of a material having a first durometer and carrying means for sealingly joining the body to a drain hose. The second portion is formed of a material having a second durometer, and includes means for mounting the body in an aperture in a structure. A bore extends through the body from one end of the first portion to an opposite end of the second portion. A bond between the first and second portions is a chemical bond. At least one enlargement formed on the first portion. The at least one enlargement has an outer diameter larger than an inner diameter of a drain hose. A surface having a diameter greater than a diameter of the stem of the first portion. An annular recess is formed between the surface and a mounting end of the second portion, the recess defining a surface for receiving a panel in the body. The first portion is joined to the second portion at the surface of the first portion. A drain end extends from the surface. The drain end has exterior surface tapering inward along two mutually opposed axes. At least one slot is formed in the drain end of the second portion. The at least one slot is fluidically coupled to the bore extending through the body. Optionally, a pair of intersecting slots are formed in the drain end of the second portion and extending from the bore through the body. In another aspect, the present invention is a method of forming a drain seal including the steps of molding a unitary body of first and second moldingly joined portions in a double shot molding operation, forming the first portion of a material having a first durometer, forming the second portion of a material having a second lower durometer, forming a bore extending through the body from one end of the first portion of the body to an opposite end of the second portion of the body, forming the first durometer material of a higher durometer than the second durometer material of the second portion of the body, forming a sealing means on the first portion of the body for joining the body to a drain hose, forming a mounting means on the second portion of the body for mounting the body in an aperture in a structure, forming enlarged ends for the first and second portions, the enlarged ends moldingly joined and forming an annular undercut or recess between a drain and of the second portion of the body and an end surface of the body. BRIEF DESCRIPTION OF THE DRAWING The various features, advantages and other uses of the present invention will become more apparent by referring to the following detailed description and drawing in which: FIG. 1 is a perspective view of a drain seal constructed in accordance with the teachings of the present invention; FIG. 2 is a side elevational view of the drain seal shown in FIG. 1; FIG. 3 is a cross-sectional view generally taken along line 3-3 of FIG. 1; and FIG. 4 is a cross-sectional view generally taken along line 4-4 of FIG. 1. DETAILED DESCRIPTION Referring now to FIGS. 1-4, there is depicted a drain seal 10 constructed in accordance with the teachings of the present invention. The drain seal 10 is uniquely formed as a one piece, monolithic body of two dissimilar different durometer materials which are chemically bonded together. The drain seal 10 includes a first element or portion 12 having a base 14 of a generally dome-like shape and a hemispherical shaped cross-section as shown in FIG. 2 extending from a central axis to an exterior peripheral edge. As also shown in FIG. 2, the peripheral edge 16 depends in an arcuate fashion with respect to the central axis. A leg 17 extends centrally from one side of the base 14. A stem 18 projects from an opposite side of the base 14. Tube joining means 20 are formed on the stem 18. By way of example only, the tube joining means includes one or more angularly extending barbs 22. The barbs 22 forcibly expand a drain tube 23 shown in FIG. 3, outward during insertion of the stem 18 into one end of the tube 23 and conforms the tube 23 which is generally formed of a softer durometer material, to the shape of the barbs 22 thereby resisting separation of the tube 23 from the drain seal 10. A longitudinal bore 24 extends through the stem 18, the base 14 and the lower leg 17. According to the present invention, the first element 12 is formed of a high durometer material, such as high density polypropylene (HDPP). The drain seal 10 also includes a second element or portion 40 which is formed of a lower durometer material than the material used to form the first element 12. By example only, the second element 40 is formed of a thermoplastic rubber (TPR), such as SANOPRENE. Again, by example, 60 durometer SANOPRENE may be employed as the material for the second element 40. While the material used to form the second element 40 is dissimilar from the material used to form the first element 12 of the drain seal 10, the two materials are selected so as to form a chemical bond during a two shot molding operation. For example, the first element 12 can be initially formed in a mold. While still in the mold, material for the second element 40 is injected into the mold and, due to the elevated temperatures associated with the molding operation, chemically bonds to the material forming the first element 12 to form a monolithic, one-piece structure for the drain seal 10. As shown in FIGS. 1-4, the second element 40 has an upper rim 42 formed with a peripheral edge 44 and having a generally dome-shaped cross-section. The rim 42 contacts the base 14 of the first element 12. A central open-ended recess 46 is formed in the second element 40 complementary to and receiving the central leg 17 of the first element 12 as shown in FIG. 4. It should be noted that while the recess 46 has been described as a structural feature of the second element 40, it will be understood that the recess 40 is not actually preformed, but merely defines wall structure which surrounds or is formed about the leg 17 of the first element 12 when the second element 40 is double shot molded about the first element 12. As shown in FIG. 1, when the second element 40 is molded about the first element 12, the rim 42 of the second element 40 will surround the inner surface and the peripheral edge 16 of the base 14 of the first element 12. These mating surfaces define the interface in which a chemical bond is formed between the materials forming the first and second elements 12 and 40 to unitarily join the first and second elements 12 and 40 into a unitary, monolithic, one piece structure. The second element 40 includes a lower portion 46 which is formed with opposed major sidewalls 50 and 52 and an intervening, opposed, side edges 53 and 54 all of which taper in two axes from a larger diameter first end 56 to a smaller diameter second end 58. The second element 40 has a mounting portion formed by an undercut or recess 60 between the inner surface of the rim 42 and the first end 56. The recess 60 has a generally annular shape extending inward from an open end adjacent the outer surface of the side walls 50 and 52 and the side edges 53 and 54. The softer durometer material used to form the second element 40 provides compression to enable the second element 40 to be inserted through an aperture 64 in a vehicle body structure, such as a sheet metal panel 66 shown in FIG. 2, until the inner edges of the panel surrounding the aperture slide into the recess 50 in the second element 40. The adjacent rim 42 of the second element 40 and the base 14 of the first element 12 provide an ergonomic surface to facilitate the insertion of the drain seal 10 through an aperture in a vehicle support structure or panel. Further, the arcuate shape of the rim 42 of the second element 40 and the base 14 of the first element 12 provide a resiliency or biasing force against the panel 66 to assist in retaining the drain seal 10 in the vehicle support structure or panel 66. As shown in FIGS. 1-4, the lower end of the second element 40 has at least one and preferably a pair of intersecting slots 70 and 72 formed at the end 58 of the second element 40. The slots 70 and 72 are formed as open-ended slots extending inward from the second end of the second element 40. The slots 60 and 62 intersect at the central axis of the second element 40 and are fluidically coupled to a bore 74 extending through the second element 40 and the contiguous bore 24 extending through the first element 12. The slots 60 and 62 facilitate egress or drainage of fluid through the bores 24 and 74 in the drain seal 10 regardless of the orientation of the vehicle. Thus, to form the drain seal 10, the first element 12 is initially formed in a mold. While the material forming the first element 12 is still at an elevated temperature, a different material used to form the second element 40 is injected into the mold and joins to the base 14 of the first element 12 at the interface described above when the rim 42 is formed as part of the second element 40. Next, the stem 18 of the first element 12 of the drain seal 10 is inserted into an open end of a drain tube 23 to fixedly join the stem 18 to the drain tube 23 and to establish fluid communication between the bores 24 and 74 in the drain seal 10 with the interior bore in the drain tube 23. It should be noted that the assembly of the drain seal 10 to the drain tube 23 can take place in the manufacturing facility of the sunroof or other structure using the drain tube 10. This enables the drain tube 10 to be shipped to the vehicle assembly plant as part of the overall sunroof or other structure which contains the drain tube 10. When the sunroof or other structure is mounted in a vehicle, drain tube 23 and attached drain seal 10 is routed through the appropriate vehicle body structure, such as one of the side pillars. The installer then grasps the base 14 and rim 42 and forcibly urges the lower portion 46 of the second element 40 through the aperture 64 in the vehicle body structure or panel 66 until the panel 66 snaps into the recess 60 in the second element 40. It should be noted, as shown in FIG. 3, that the engagement of the panel 66 in the recess 60 causes a deformation of the peripheral edges of the rim 42 and possibly the base 14. This causes an inherent resilient force to be formed in the rim 42 and possibly the base 14 which biases the drain seal 10 into engagement with the panel 66. The slots 70 and 72 in the second end 58 of the second element 40 of the drain seal 10 are now positioned to provide a drainage outlet for water flowing through the drain tube 23 and the bores 24 and 74 in the drain seal 10. | <SOH> BACKGROUND <EOH>Sun roof assemblies are a common option in automotive vehicles. Such sun roof assemblies can be of the tilting and/or sliding type and have a panel mounted in a roof opening in the vehicle. The panel is moveably supported in a pair of longitudinally extending guide rails affixed to the vehicle roof A trough extends around the edge of the roof opening and collects water when the sun roof panel is open or if any water passes through the sealing structure typically employed with the sun roof panel. This drain trough is connected to one or more drain tubes which are typically run through the vehicle body side pillars. A lower end of the tube is open to allow water to be discharged from the vehicle. The bottom of the drain tube receives a drain seal which provides the dual functions of fixing one end of the drain tube to the vehicle body structure as well as providing a small, one way opening to allow water collected by the drain tube to exit the drain tube while at the same time preventing the entry of water or debris into the lower end of the drain tube. Prior drain seals have been formed of two separate elements which are joined together, typically by an adhesive. The two different elements have different shapes to serve different functions as well as being formed of different materials to again serve specific, different functions. One of the elements is formed of a softer durometer material to serve as a seal to the vehicle body structure. The other element is typically formed of a higher durometer material for fixed mounting of the drain seal to the drain tube. While effective, the prior art drain seals involve multiple parts which must be joined together. This increases the cost of the drain seal. It would be desirable to provide a drain seal for an automotive vehicle which can be manufactured at a lower cost while still providing all of the required functions of a drain seal. | <SOH> SUMMARY <EOH>The inventive drain seal provides all the functions of a typical drain seal for a sun roof drain tube while, at the same time, having a unitary one piece construction thereby eliminating secondary assembly operations for lower manufacturing costs and improved reliability. The inventive drain seal mounts a drain hose to a vehicle support structure while allowing drainage of fluid from the attached drain hose. In one aspect, the drain seal includes a molded, unitary, monolithic body having first and second moldingly joined portions, the first portion formed of a material having a first durometer and carrying means for sealingly joining the body to a drain hose. The second portion is formed of a material having a second durometer, and includes means for mounting the body in an aperture in a structure. A bore extends through the body from one end of the first portion to an opposite end of the second portion. A bond between the first and second portions is a chemical bond. At least one enlargement formed on the first portion. The at least one enlargement has an outer diameter larger than an inner diameter of a drain hose. A surface having a diameter greater than a diameter of the stem of the first portion. An annular recess is formed between the surface and a mounting end of the second portion, the recess defining a surface for receiving a panel in the body. The first portion is joined to the second portion at the surface of the first portion. A drain end extends from the surface. The drain end has exterior surface tapering inward along two mutually opposed axes. At least one slot is formed in the drain end of the second portion. The at least one slot is fluidically coupled to the bore extending through the body. Optionally, a pair of intersecting slots are formed in the drain end of the second portion and extending from the bore through the body. In another aspect, the present invention is a method of forming a drain seal including the steps of molding a unitary body of first and second moldingly joined portions in a double shot molding operation, forming the first portion of a material having a first durometer, forming the second portion of a material having a second lower durometer, forming a bore extending through the body from one end of the first portion of the body to an opposite end of the second portion of the body, forming the first durometer material of a higher durometer than the second durometer material of the second portion of the body, forming a sealing means on the first portion of the body for joining the body to a drain hose, forming a mounting means on the second portion of the body for mounting the body in an aperture in a structure, forming enlarged ends for the first and second portions, the enlarged ends moldingly joined and forming an annular undercut or recess between a drain and of the second portion of the body and an end surface of the body. | 20040225 | 20070529 | 20050825 | 68507.0 | 0 | BOCHNA, DAVID | DRAIN SEAL FOR VEHICLE DRAIN TUBE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,787,023 | ACCEPTED | Method for interconnecting multiple printed circuit boards | A method for electrically interconnecting two printed circuit boards includes the steps of: providing a first printed circuit board (20); providing a second printed circuit board (30); providing a receiving slot (22) in one of the first and the second printed circuit boards such that the first and the second printed circuit boards are orthogonally intersected with each other; and providing at least one electrical connector (1) adjacent the receiving slot and in electrical connection with the first and the second printed circuit boards. | 1. A method for electrically interconnecting two printed circuit boards, comprising the steps of: providing a first printed circuit board; providing a second printed circuit board; providing a receiving slot in one of the first and the second printed circuit boards such that the first and the second printed circuit boards are orthogonally intersected with each other; and providing at least one electrical connector adjacent the receiving slot and in electrical connection with the first and the second printed circuit boards. 2. The method as recited in claim 1, wherein the first and the second printed circuit boards together define four quadrants. 3. The method as recited in claim 2, wherein the at least one electrical connector comprises a first connector arranged in a first quadrant and a second connector arranged in a fourth quadrant. 4. The method as recited in claim 3, wherein the first and the second connectors are mounted on the second printed circuit board. 5. The method as recited in claim 4, wherein the first and the second electrical connectors each comprise an electrical contact and an actuator capable of actuating the contact to have a wiping contact with the first and the second printed circuit boards. 6. A method for electrically interconnecting multiple printed circuit boards, comprising the steps of: providing a plurality of first printed circuit boards; providing a plurality of second printed circuit boards; providing receiving slots in either the first printed circuit boards or the second printed circuit boards such that the first and the second printed circuit boards are orthogonally intersected with each other, every two orthogonally arranged printed circuit boards together defining four quadrants; and providing, in at least one of the four quadrants of every two orthogonally arranged printed circuit boards, a respective electrical connector to electrically interconnect the first and the second printed circuit boards. 7. The method as recited in claim 6, wherein the receiving slot is defined in the first printed circuit board. 8. The method as recited in claim 7, wherein the first and the second quadrants of every two orthogonally arranged printed circuit boards each have the electrical connector arranged therein, and each connector is mounted on the second printed circuit board. 9. The method as recited in claim 8, wherein the connectors respectively arranged in the first and the second quadrants are mirror image with respect to the second printed circuit board. 10. The method as recited in claim 9, wherein the third and the fourth quadrants of every two orthogonally arranged printed circuit boards each have the electrical connector arranged therein. 11. The method as recited in claim 10, wherein the connectors respectively arranged in the third and the fourth quadrants are mirror image with respect to the second printed circuit board. 12. The method as recited in claim 11, wherein the connectors respectively arranged in the first and the fourth quadrants are mirror image with respect to the first printed circuit board. 13. A method for configuring an electrical system adapted for mating with a complementary device, comprising the steps of: providing a printed circuit board having a surface; providing a first group of conductive traces on the surface; providing a second group of conductive traces on the surface and spaced from the first conductive traces; mounting a first electrical connector on the first group of the conductive traces, the first electrical connector defining a mating face; and mounting a second electrical connector on the second group of the conductive traces, the second electrical connector defining a second mating face facing the first mating face. 14. A method of making an interconnection system, comprising steps of: providing a first set of parallel spaced printed circuit boards defining first front edge sections thereof, respectively; providing a second set of parallel spaced printed circuit boards defining second front edge sections thereof, respectively; and intersecting each of said first set of parallel spaced printed circuit boards with all of said second set of parallel spaced printed circuit boards, respectively, around the first front edge section of said each of the first set of parallel spaced printed circuit boards and the second front edge sections of said second set of parallel spaced printed circuit boards. 15. The method as recited in claim 14, further including a step of providing at least one electrical connector located in one of four quadrants derived from intersection by said each of said first set of parallel spaced printed circuit boards and the corresponding one of said second set of parallel spaced printed circuit boards, and electrically connected to said each of said first set of parallel spaced printed circuit boards and the corresponding one of said second set of parallel spaced printed circuit boards. 16. The method as recited in claim 15, wherein said connector extends in a longitudinal direction with a plurality of juxtaposed contacts therein, and said longitudinal direction is parallel to a center line defined by said four quadrants. | CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part application of U.S. patent application Ser. No. 10/669,969 entitled “ELECTRICAL CONNECTOR FOR INTERCONNECTING TWO INTERSECTED PRINTED CIRCUIT BOARDS”, and Ser. No. 10/669,968 entitled “ELECTRICAL INTERCONNECTION BETWEEN MULTIPLE PRINTED CIRCUIT BOARDS”, both of which are assigned to the same assignee with this application. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for interconnecting multiple printed circuit boards, and more particularly to a method for interconnecting a plurality of orthogonally arranged printed circuit boards. 2. Description of Related Art Various electronic systems, especially a telecommunication system, servers and switches, comprise a wide array of components mounted on printed circuit boards, such as daughterboards and motherboards. The motherboard to which the daughterboards are connected are generally referred to as backplane as it is stationary. Connectors used to assemble the daughterboards, which are removable, to the motherboards are referred to as backplane connectors. The motherboard and the daughterboard are interconnected by the connectors so as to transfer signals and power throughout the systems. Typically, the motherboard, backplane, is a printed circuit board that is mounted in a server or a switch and is provided with a plurality of backplane connectors. Multiple daughterboards are also each provided with a mating connector and then removeably plugged into the connectors on the backplane. After all the daughterboards are interconnected to the backplane, the daughterboards are interconnected through the backplane and are arranged parallel to each other. However, connecting the daughterboards via the backplane leads to the potential for signal interference. Because the daughterboards are all connected via the backplane, signal strength may be attenuated as signals travel through the backplane. In general, signals passing between two daughterboards pass through at least a first connector pair between a first daughterboard and the backplane, and a second connector pair between the backplane and a second daughterboard. In general, the signal passes through totally two pairs of mated connectors, and each time the signal is attenuated as it passes. Generally, the arrangement between the backplane and the daughterboard can be referred to as a “TTTT” type viewed from atop, i.e. the backplane is arranged in a horizontal direction, while the daughterboard is arranged in a position perpendicular to the backplane. In some cases, both sides of the backplane are all provided with connectors for assembling the daughterboards from both sides. This arrangement can be referred to as a “++++” type viewed from atop. In this arrangement, the daughterboards arranged in both sides are in communication with each other through the motherboard, i.e. centerplane. Many connectors have been provided for achieving such arrangement. U.S. Pat. No. 5,993,259 (the '259 patent) issued to Stokoe et al. discloses an electrical connector of such application. The connector disclosed in the '259 patent includes a plurality of modularized wafers bounded together. As shown in FIG. 4 of the '259 patent, the terminals are stamped from a metal sheet and then embedded within an insulative material to form the wafer. U.S. Pat. No. 6,083,047 issued to Paagman discloses an approach to make a high-density connector by introducing the use of printed circuit boards. Conductive traces are formed on surfaces of the printed circuit board in a mirror-image arrangement, typically shown in FIG. 12. U.S. Pat. No. 6,267,604 issued to Mickievicz et al. discloses a similar configuration. U.S. Pat. No. 5,356,301 issued to Champion et al. discloses a pair of back-to-back arranged plug connectors mounted on opposite sides of a motherboard via common contacts for respectively connecting with a receptacle connector mounted on a daughterboard and a cable connector. However, all connectors suggested above are all mounted on the backplane or centerplane. As it is well known that if the centerplane can be eliminated such that the daughterboards can be directly interconnected with each other, then the signal attenuation as well as the interference can be largely reduced. However, none of the connectors provided yet meets such a requirement. U.S. Pat. No. 6,540,522 (the '522 patent) issued to Sipe sheds light on eliminating the centerplane, i.e. two daughterboards can be interconnected orthogonally, as clearly shown in FIG. 9. This is really a leap step. However, the signal still travels a long distance from one end of a first connector on a first circuit board, to a second connector on a second circuit board. This signal attenuation is still left unsolved. On the other hand, all these above mentioned connectors could be mounted on a single side and along an edge of the motherboard as well as the daughterboards. As shown in FIG. 9 of the '522 patent, it is impossible to install a second set connectors on the opposite side of the boards. Traditionally, if a contact defines a longitudinal direction, then a mating direction of an electrical component, i.e. a mating contact of a complementary connector or a conductive pad of a printed circuit board has to be the same direction as the contact. Before the present invention, it is impossible to insert a card into a card-edge connector where the insertion direction of the card is orthogonal to the contact within the connector. If the contacts are not well arranged, the insertion of the card will collapse the contacts within the connector. The contacts have to be retracted behind a mating face of the connector during the insertion of the card, and then extend beyond the mating face after the card arrives to its final position. None of the existing connectors meets such a requirement. For example, U.S. Pat. No. 6,508,675, assigned to the same assignee with this patent application, discloses a configuration providing the shortest electrical path between two orthogonally arranged printed circuit boards. It can be easily appreciated, as shown in FIGS. 1 and 2, that if the printed circuit board is not inserted into a slot of a connector along a top-to-bottom direction, i.e. a vertical direction, viewed from the drawings, contact portions of contacts extending into the slot will surely be damaged by the insertion of the circuit board. In order to let the circuit board be inserted into the slot from a direction other than the top-to-bottom direction, a mechanism has to be invented to control the contact such that the contact is retracted behind the mating face when the printed circuit board is inserted and extends over the mating face after the printed circuit board is finally positioned. The present invention aims to provide an improved method for interconnecting multiple printed circuit boards to solve the above-mentioned problems. SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for interconnecting a plurality of orthogonally arranged printed circuit boards in which a shortest electrical path is reached. It is another object of the present invention to provide a method for interconnecting orthogonally arranged printed circuit boards, wherein at least an electrical connector is arranged in a quadrant defined between two orthogonally arranged printed circuit boards. In order to achieve the objects set forth, a method for electrically interconnecting a plurality of horizontally arranged stationary boards and a plurality of vertically arranged removeable boards comprises the steps of: a) providing a stationary board; 2) providing a removeable board; 3) providing a receiving slot in one of the stationary and the removeable boards; and 4) providing an electrical connector arranged adjacent to the receiving slot to thereby electrically interconnecting the stationary and the removeable boards. According to one aspect of the present invention, it is yet provided with an electrical interconnection system. The electrical interconnection system comprises a first printed circuit board defining a receiving slot, a second printed circuit board assembled to the first printed circuit board and having an edge received in the receiving slot, and an electrical connector comprising contacts electrically connecting with the first and the second printed circuit boards. According to another aspect of the present invention, the connector is mounted on the second printed circuit board and has a mating face and a mounting face perpendicular to each other. Each electrical contact of the connector includes a first end electrically contacting with the first printed circuit board, and a second end electrically contacting with the second printed circuit board. An actuator is associated with the electrical connector and includes a base defining a plurality of holes in which the second ends of the electrical contacts are received. The actuator is actuated to move from a first position in which the first ends of the contacts are closer to the second printed circuit board, and a second position in which the first ends of the contacts are farther to the second printed circuit board. Still according to another aspect of the present invention, the electrical connector for electrically interconnecting two printed circuit boards comprises a dielectric housing defining first and second faces perpendicular to each other and a plurality of passageways extending from the first face to the second face. A plurality of electrical contacts each is moveably received in a corresponding passageway and each includes a first end extending beyond the first face and a second end extending beyond the second face. An actuator is associated with the housing and defines a plurality of holes receiving the first ends of the contacts so as to actuate the contacts to move in the passageways. Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing summary, as well as the following detailed description of the preferred embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, embodiments which are presently preferred. It should be understood, however, that the present invention is not limited to the precise arrangements and instrumentality shown in the attached drawings. FIG. 1 is an illustration of a solution provided by the present invention in which a plurality of stationary boards each is provided with a plurality of slots for receiving multiple removeable daughter boards; FIG. 2 is an assembled view of FIG. 1; FIG. 3 is an end view of FIG. 2; FIG. 4 is a partial, cut-away view showing the stationary board (horizontal) and the removeable board (vertical) are electrically interconnected by a connector made in accordance with the present invention; FIG. 5 is a cross-sectional view of FIG. 4; FIG. 6 is an illustration before actuation of an actuator; FIG. 7 is an illustration after actuation of the actuator, showing a contact coupled with the actuator moving downwardly and outwardly marked by arrows A and B; FIG. 8 is an illustration showing the stationary board and the removeable board are electrically interconnected by four connectors, in which two connectors are away from the removeable board for illustration; FIG. 9 is a view similar to FIG. 8 but showing the four connectors are finally positioned; FIG. 10 shows a relationship between the contacts and the actuators; FIG. 11 is a side view showing an end of the contact engaging with a dielectric boot of the actuator; FIG. 12 is a perspective view of the connector, prior to the assembly of the actuator; FIG. 13 is a perspective view showing conductive pads and holes are arranged on the removeable board and showing two connectors are mounted on the removeable board; FIG. 14 is a perspective view showing the slot on the stationary board and conductive pads arranged therealong; FIG. 15 is a perspective view showing the connectors mounted on the stationary and the removeable boards; and FIG. 16 is a schematic view showing the stationary and the removeable boards are interconnected by the connectors. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Reference will now be made in detail to the preferred embodiment of the present invention. Referring to FIGS. 1, 2 and 3, a plurality of horizontal boards 20 and a plurality of vertical boards 30 are intersected with each other to form a plurality of interconnections or nodes 203 therebetween. For discussion purpose, the horizontal board 20 is referred to as the “stationary board”, while the vertical board 30 is referred to as the “removeable board”. Referring to FIGS. 4 and 5, an electrical connector 1 in accordance with the present invention is provided to electrically interconnect the stationary board 20 and the removeable board 30. The connector 1 comprises a dielectric housing 10 defining a plurality of passageways 11 between a mating face 10a and a mounting face 10b adjacent to each other, and a plurality of contacts 12 moveably received in the passageways 11. That is, the contacts 12 are moveable with respect to the housing 10. It is noted that the contacts 12 being moveable with respect to the housing 10 also include a pivotal design fixed at a certain point or a fixed design with a moveable part and etc as long as the contacts 12 can move along the stationary board 20, in addition to the design described hereinafter. Each contact 12 includes a first contacting end 12a extending over the mating face 10a and a second contacting end 12b extending over the mounting face 10b. The passageway 11 is designed to have open ends 11a, 11b such that the first contacting end 12a and the second contacting end 12b of the contact 12 can move along the mating face 10a and the mounting face 10b, respectively. The contact 12 is stamped from a sheet of metal. According to a preferred embodiment, the contact 12 is preferable rigid or less flexibility. The physical property makes the contact 12 easily to move within the passageway 11 when an external force is applied to the contact 12. The electrical connector 1 further includes a plurality of biasing springs 14. Each biasing spring 14 includes an anchor 14a securely retained in an anchoring slit 13 of the dielectric housing 10, a spring arm 14b extending from the anchor 14a and an insulator 14c connecting with a free end of the spring arm 14b. The insulator 14c can be integrally formed with the spring arm 14b, or can be firstly molded and then assembled to the spring arm 14b. The plurality of biasing springs 14 can also be integrated as a single one. The insulator 14c of the biasing spring 14 provides a biasing force to the first end 12a of the contact 12. The electrical connector 1 is further provided with an actuator 15 moveably arranged along the mounting face 10b. The actuator 15, according to the preferred embodiment, includes a main body 15a made of a metal sheet and a dielectric boot 15b connecting with the main body 15a. The dielectric boot 15b define a plurality of holes 150 receiving therein the second contacting ends 12b of the contacts 12. Accordingly, when the actuator 15 is moved downward along the mounting face 10b of the housing 10, the second contacting end 12b of the contact 12 is moved downward along the mounting face 10b, while the first contacting end 12a of the contact 12 moves away from the removeable board 30. As mentioned above, the biasing spring 14 provides a driving force to the contact 12. As such, when the contact 12 is moved with the movement of the actuator 15, the first end 12a and the second end 12b of the contact 12 provide a wiping contact with respect to corresponding conductive pads 21, 31 on the stationary board 20 and the removeable board 30. As clearly shown in FIGS. 10 and 11, the second end 12b of the contact 12 is connected with the boot 15b of the actuator 15. As such, when the actuator 15 is moved, the contact 12 is moved accordingly. The electrical connector 1 further includes a metal shell 16 attached to the housing 10 and shielding the contacts 12 from being influenced by electromagnetic interference. Referring to FIGS. 12 and 13, the housing 10 has a pair of projections 100 formed on the mounting face 10b adjacent opposite sides 102 of the housing 10. The pair of projections 100 defines a cavity 104 therebetween for receiving the actuator 15. The housing 10 is formed with a pair of positioning pins 10c for positioning the connector 1 on the removeable board 30 and defines a pair of through holes 10d receiving a pair of locking bolts 10e for securely attaching the connector 1 to the removeable board 30. Accordingly, the shell 16 can be grounded to the removeable board 30 or the stationary board 20. FIGS. 6 and 7 illustrate the movement of the contact 12 within the passageway 11 of the housing 10 when the actuator 15 is actuated. As shown in FIG. 6, the removeable board 30 is intersected with the stationary board 20. When the connector 1 is securely mounted on the removeable board 30, the contact 12 is normally pushed toward the conductive pad 31 of the removeable board 30 by the driving force applied to the contact 12 from the biasing spring 14. In this position, the second end 12b of the contact 12 is located in a highest position within the passageway 11 and the spring arm 14b is substantially perpendicular to the stationary board 20. When the actuator 15 is moved downward, the second ends 12b of the contacts 12 are moved downward as illustrated by arrow A with the movement of the boot 15b. Accordingly, the first ends 12a of the contacts 12 are moved along the stationary board 20 in a direction away from the removeable board 30 as illustrated by arrow B. The spring arm 14b provides a driving force to the first end 12a of the contact 12 to thereby hold the actuator 15 in position. By this arrangement, the first ends 12a and the second ends 12b of the contacts 12 electrically abut against the conductive pads 21, 31 of the stationary board 20 and the removeable board 30, respectively. Accordingly, an electrical connection is established between the stationary board 20 and the removeable board 30 through the connector 1. As clearly shown in FIG. 7, the first end 12a of the contact 12 moves along the stationary board 20 in a first direction and the second end 12b of the contact 12 moves along the removeable board 30 in a second direction which is perpendicular to the first direction. This is a great leap advancing the achievement of solving the long-expected but unsolved market demanding. By the provision of the connector 1 in accordance with the present invention, the long-expected request has been finally solved. Referring to FIG. 13, the removeable board 30 defines a pair of positioning holes 32 receiving therein the positioning pins 10c of the connector 1 and a pair of mounting holes 33 receiving therein the pair of locking bolts 10e for mounting the connector 1 on the removeable board 30. The conductive pads 31 are arranged on opposite side faces of the removeable board 30 between the pair of mounting holes 33. For description purpose, the conductive pads 31, the positioning holes 32 and the mounting holes 33 are collectively referred to as “footprints”. Referring to FIGS. 8 and 9 in conjunction with FIG. 13, the “footprints” are arranged in such manner that two connectors 1 are mounted on one side of the removeable board 30 in a substantially mirror-image manner. These two connectors 1 are spaced apart from each other to define a receiving channel 18 therebetween. The receiving channel 18 is adapted to receive the stationary board 20. Referring to FIG. 14 in conjunction with FIG. 4, the stationary board 20 defines a receiving slot 22 extending from an edge 20a thereof to receive an edge 30a (FIGS. 1 and 13) of the removeable board 30 to make the stationary board 20 be readily received into the channel 18, thereby establishing the electrical connection between the removeable board 30 and the stationary board 20 via the connector 1. The conductive pads 21 are arranged along the receiving slot 22. As shown in FIG. 9, when the stationary board 20 and the removeable board 30 are intersected with each other, four connectors 1 can be used to interconnect the stationary board 20 and the removeable board 30. This provides a robust flexibility to a system designer as the designer can readily select the numbers for the interconnections therebetween so as to achieve the enhanced electrical performance. From a view point of math, four quadrants are defined by the stationary board 20 and the removeable board 30. In the preferable embodiment, four connectors 1 are provided to be each located at a corresponding quadrant. It can be readily appreciated that the numbers of the connectors 1 can be specially selected according to the actual requirement. For example, the removeable board 30 can be provided with only two connectors 1 respectively located at first and second quadrants or first and third quadrants or first and fourth quadrants. This provides a high flexibility of the interconnection between the stationary board 20 and the removeable board 30. According to the above disclosures, a method for electrically interconnecting the horizontally arranged stationary board 20 and the vertically arranged removeable board 30 comprises the steps of: a) providing the stationary board 20 having the conductive pads 21; b) providing the removeable board 30 having the conductive pads 31; c) providing the receiving slot in one of the stationary board 20 and the removeable board 30; and d) providing the connector 1 located adjacent to the receiving slot to thereby electrically interconnecting the stationary board 20 and the removeable board 30. Referring to FIGS. 15 and 16, in this embodiment, each quadrant is provided with a connector 1. However, it is not imperative that each quadrant be mounted with a connector 1. It all depends on the actual requirements and implementations. By this arrangement, there is a good flexibility for the designer to arrange the interconnection between the removeable board 30 and the stationary board 20. The connector 1 in accordance with the present invention can be made in various ways. In this embodiment, the housing 10 of the connector 1 is first formed with the passageways 11, the contacts 12 are then inserted into the passageways 11 and the biasing springs 14 are assembled to the housing 10. Finally, the shell 16 is attached to the housing 10 to partially enclose the housing 10. It is noted that the connector 1 can be configured by a plurality of wafers as teaching in U.S. Pat. No. 6,508,675. Each wafer may define the passageway 11 receiving the contact 12 therein. The biasing spring 14 can be assembled to the wafer as well. Finally, the wafers are assembled together. It is preferable to configure the connector 1 through the wafer arrangement. On the other hand, two contacts 12 can be received in one passageway 11 to serve as a differential pair. In this embodiment, the contact 12 can be a wire, such as a gold wire, encapsulated by insulative plastic material. It should be noted that the connector 1 can be arranged on the stationary board, i.e. motherboard 20, while the receiving slot is arranged on the removeable board 30, if necessary. The present invention provides a robust flexibility such that the designer can do whatever they want to do so as to achieve optimum electrical interconnections between the stationary boards 20 and the removeable boards 30. It should be also noted that even the concept of the receiving slot is introduced so as to interconnect the stationary board 20 and the removeable board 30. Alternatively, the stationary board 20 can be provided with extended tabs having conductive pads thereon so as to make electrical interconnections with the removeable board 30 via the connector 1. As such, a variety of embodiments can be implemented within the scope of the present invention. It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a method for interconnecting multiple printed circuit boards, and more particularly to a method for interconnecting a plurality of orthogonally arranged printed circuit boards. 2. Description of Related Art Various electronic systems, especially a telecommunication system, servers and switches, comprise a wide array of components mounted on printed circuit boards, such as daughterboards and motherboards. The motherboard to which the daughterboards are connected are generally referred to as backplane as it is stationary. Connectors used to assemble the daughterboards, which are removable, to the motherboards are referred to as backplane connectors. The motherboard and the daughterboard are interconnected by the connectors so as to transfer signals and power throughout the systems. Typically, the motherboard, backplane, is a printed circuit board that is mounted in a server or a switch and is provided with a plurality of backplane connectors. Multiple daughterboards are also each provided with a mating connector and then removeably plugged into the connectors on the backplane. After all the daughterboards are interconnected to the backplane, the daughterboards are interconnected through the backplane and are arranged parallel to each other. However, connecting the daughterboards via the backplane leads to the potential for signal interference. Because the daughterboards are all connected via the backplane, signal strength may be attenuated as signals travel through the backplane. In general, signals passing between two daughterboards pass through at least a first connector pair between a first daughterboard and the backplane, and a second connector pair between the backplane and a second daughterboard. In general, the signal passes through totally two pairs of mated connectors, and each time the signal is attenuated as it passes. Generally, the arrangement between the backplane and the daughterboard can be referred to as a “TTTT” type viewed from atop, i.e. the backplane is arranged in a horizontal direction, while the daughterboard is arranged in a position perpendicular to the backplane. In some cases, both sides of the backplane are all provided with connectors for assembling the daughterboards from both sides. This arrangement can be referred to as a “++++” type viewed from atop. In this arrangement, the daughterboards arranged in both sides are in communication with each other through the motherboard, i.e. centerplane. Many connectors have been provided for achieving such arrangement. U.S. Pat. No. 5,993,259 (the '259 patent) issued to Stokoe et al. discloses an electrical connector of such application. The connector disclosed in the '259 patent includes a plurality of modularized wafers bounded together. As shown in FIG. 4 of the '259 patent, the terminals are stamped from a metal sheet and then embedded within an insulative material to form the wafer. U.S. Pat. No. 6,083,047 issued to Paagman discloses an approach to make a high-density connector by introducing the use of printed circuit boards. Conductive traces are formed on surfaces of the printed circuit board in a mirror-image arrangement, typically shown in FIG. 12. U.S. Pat. No. 6,267,604 issued to Mickievicz et al. discloses a similar configuration. U.S. Pat. No. 5,356,301 issued to Champion et al. discloses a pair of back-to-back arranged plug connectors mounted on opposite sides of a motherboard via common contacts for respectively connecting with a receptacle connector mounted on a daughterboard and a cable connector. However, all connectors suggested above are all mounted on the backplane or centerplane. As it is well known that if the centerplane can be eliminated such that the daughterboards can be directly interconnected with each other, then the signal attenuation as well as the interference can be largely reduced. However, none of the connectors provided yet meets such a requirement. U.S. Pat. No. 6,540,522 (the '522 patent) issued to Sipe sheds light on eliminating the centerplane, i.e. two daughterboards can be interconnected orthogonally, as clearly shown in FIG. 9. This is really a leap step. However, the signal still travels a long distance from one end of a first connector on a first circuit board, to a second connector on a second circuit board. This signal attenuation is still left unsolved. On the other hand, all these above mentioned connectors could be mounted on a single side and along an edge of the motherboard as well as the daughterboards. As shown in FIG. 9 of the '522 patent, it is impossible to install a second set connectors on the opposite side of the boards. Traditionally, if a contact defines a longitudinal direction, then a mating direction of an electrical component, i.e. a mating contact of a complementary connector or a conductive pad of a printed circuit board has to be the same direction as the contact. Before the present invention, it is impossible to insert a card into a card-edge connector where the insertion direction of the card is orthogonal to the contact within the connector. If the contacts are not well arranged, the insertion of the card will collapse the contacts within the connector. The contacts have to be retracted behind a mating face of the connector during the insertion of the card, and then extend beyond the mating face after the card arrives to its final position. None of the existing connectors meets such a requirement. For example, U.S. Pat. No. 6,508,675, assigned to the same assignee with this patent application, discloses a configuration providing the shortest electrical path between two orthogonally arranged printed circuit boards. It can be easily appreciated, as shown in FIGS. 1 and 2, that if the printed circuit board is not inserted into a slot of a connector along a top-to-bottom direction, i.e. a vertical direction, viewed from the drawings, contact portions of contacts extending into the slot will surely be damaged by the insertion of the circuit board. In order to let the circuit board be inserted into the slot from a direction other than the top-to-bottom direction, a mechanism has to be invented to control the contact such that the contact is retracted behind the mating face when the printed circuit board is inserted and extends over the mating face after the printed circuit board is finally positioned. The present invention aims to provide an improved method for interconnecting multiple printed circuit boards to solve the above-mentioned problems. | <SOH> SUMMARY OF THE INVENTION <EOH>It is an object of the present invention to provide a method for interconnecting a plurality of orthogonally arranged printed circuit boards in which a shortest electrical path is reached. It is another object of the present invention to provide a method for interconnecting orthogonally arranged printed circuit boards, wherein at least an electrical connector is arranged in a quadrant defined between two orthogonally arranged printed circuit boards. In order to achieve the objects set forth, a method for electrically interconnecting a plurality of horizontally arranged stationary boards and a plurality of vertically arranged removeable boards comprises the steps of: a) providing a stationary board; 2) providing a removeable board; 3) providing a receiving slot in one of the stationary and the removeable boards; and 4) providing an electrical connector arranged adjacent to the receiving slot to thereby electrically interconnecting the stationary and the removeable boards. According to one aspect of the present invention, it is yet provided with an electrical interconnection system. The electrical interconnection system comprises a first printed circuit board defining a receiving slot, a second printed circuit board assembled to the first printed circuit board and having an edge received in the receiving slot, and an electrical connector comprising contacts electrically connecting with the first and the second printed circuit boards. According to another aspect of the present invention, the connector is mounted on the second printed circuit board and has a mating face and a mounting face perpendicular to each other. Each electrical contact of the connector includes a first end electrically contacting with the first printed circuit board, and a second end electrically contacting with the second printed circuit board. An actuator is associated with the electrical connector and includes a base defining a plurality of holes in which the second ends of the electrical contacts are received. The actuator is actuated to move from a first position in which the first ends of the contacts are closer to the second printed circuit board, and a second position in which the first ends of the contacts are farther to the second printed circuit board. Still according to another aspect of the present invention, the electrical connector for electrically interconnecting two printed circuit boards comprises a dielectric housing defining first and second faces perpendicular to each other and a plurality of passageways extending from the first face to the second face. A plurality of electrical contacts each is moveably received in a corresponding passageway and each includes a first end extending beyond the first face and a second end extending beyond the second face. An actuator is associated with the housing and defines a plurality of holes receiving the first ends of the contacts so as to actuate the contacts to move in the passageways. Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. | 20040224 | 20050719 | 20050324 | 95583.0 | 0 | TSUKERMAN, LARISA Z | METHOD FOR INTERCONNECTING MULTIPLE PRINTED CIRCUIT BOARDS | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,787,040 | ACCEPTED | User interface for representing logical path information and displaying available adapters in a storage subsystem | A user interface facilitates copying data between storage resources, such as servers. A user selects a source storage resource and a target storage resource. Available adapters are displayed through which a path can be established between the selected source and target storage resources. The user selects at least one of the available adapters to configure the path to copy data from the selected source storage resource to the selected target storage resource. The list of available adapters is dynamically updated so that only currently available adapters are displayed. The displayed adapters may be further limited to those that are compatible with a certain path type selected by the user, such as adapters used for a unidirectional or a bi-directional path. | 1. A method for copying data, comprising: displaying a user interface from which a user selects a source storage resource and a target storage resource; and displaying available adapters, via the user interface, through which a path can be established between the selected source storage resource and the selected target storage resource; wherein the user selects at least one of the available adapters, via the user interface, to configure the path to copy data from the selected source storage resource to the selected target storage resource. 2. The method of claim 1, wherein: the selected source storage resource and the selected target storage resource comprise respective storage servers. 3. The method of claim 1, wherein: the user selects the selected source storage resource by selecting, via the user interface, a source storage server and an associated logical subsystem. 4. The method of claim 1, wherein: the user selects the selected target storage resource by selecting, via the user interface, a target storage server and an associated logical subsystem. 5. The method of claim 1, wherein: the user selects a path type, via the user interface, from among a plurality of different path types; and the displaying available adapters comprises displaying available adapters whose type is compatible with the selected path type. 6. The method of claim 5, wherein: the plurality of different path types include unidirectional and bi-directional path types. 7. The method of claim 1, wherein: the path comprises a switched path, wherein at least one switch is provided between the selected source storage resource and the selected target storage resource; and the user selects an outgoing port of the at least one switch, via the user interface, to configure the path. 8. The method of claim 1, wherein: the path comprises a switched path, wherein at least one switch is provided between the selected source storage resource and the selected target storage resource; the available adapters include target adapters that are associated with the selected target storage resource; and the user selects at least one of the target adapters to configure the path. 9. The method of claim 1, wherein: the configured path comprises a direct connection between the selected source storage resource and the selected target storage resource. 10. The method of claim 1, further comprising: displaying dynamically-updated status information, via the user interface, regarding the configured path. 11. The method of claim 1, further comprising: providing a wizard, via the user interface, for guiding the user in selecting the selected source storage resource, the selected target storage resource, and the at least one of the available adapters. 12. A program storage device tangibly embodying a program of instructions executable by a machine to perform a method for copying data, the method comprising: displaying a user interface from which a user selects a source storage resource and a target storage resource; and displaying available adapters, via the user interface, through which a path can be established between the selected source storage resource and the selected target storage resource; wherein the user selects at least one of the available adapters, via the user interface, to configure the path to copy data from the selected source storage resource to the selected target storage resource. 13. The program storage device of claim 12, wherein: the user selects a path type, via the user interface, from among a plurality of different path types; and the displaying available adapters comprises displaying available adapters whose type is compatible with the selected path type. 14. The program storage device of claim 12, wherein: the path comprises a switched path, wherein at least one switch is provided between the selected source storage resource and the selected target storage resource; the available adapters include target adapters that are associated with the selected target storage resource; and the user selects at least one of the target adapters to configure the path. 15. The program storage device of claim 12, wherein the method further includes: displaying dynamically-updated status information, via the user interface, regarding the configured path. 16. An apparatus for copying data, comprising: means for displaying a user interface from which a user selects a source storage resource and a target storage resource; and means for displaying available adapters, via the user interface, through which a path can be established between the selected source storage resource and the selected target storage resource; wherein the user selects at least one of the available adapters, via the user interface, to configure the path to copy data from the selected source storage resource to the selected target storage resource. 17. The apparatus of claim 16, wherein: the user selects a path type, via the user interface, from among a plurality of different path types; and the means for displaying available adapters displays available adapters whose type is compatible with the selected path type. 18. The apparatus of claim 16, wherein: the path comprises a switched path, wherein at least one switch is provided between the selected source storage resource and the selected target storage resource; the available adapters include target adapters that are associated with the selected target storage resource; and the user selects at least one of the target adapters to configure the path. 19. The apparatus of claim 16, further comprising: means for displaying dynamically-updated status information, via the user interface, regarding the configured path. | BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates generally to the field of data storage in computer systems and, more specifically, to a copy services user interface for a storage subsystem for representing complex logical path information, and for displaying available adapters through which a remote copying path can be established. 2. Description of the Related Art Computer storage devices such as storage servers have high-capacity disk arrays to backup data from external host systems, such as host servers. For example, a large corporation or other enterprise may have a network of servers that each store data for a number of workstations used by individual employees. Periodically, the data on the host servers is backed up to the high-capacity storage server to avoid data loss if the host servers malfunction. A storage server may also backup data from another storage server, such as at a remote site, in a peer-to-peer copying operation. The storage servers are also known to employ redundant systems to provide additional safeguards against data loss. The IBM Enterprise Storage Server (ESS) is an example of a storage server. However, it is often difficult for the user to configure appropriate paths for copying data from a source storage server to a target storage server, and to ascertain complex logical path information once the paths are configured. BRIEF SUMMARY OF THE INVENTION To address these and other issues, the present invention describes a method and system for assisting a user in configuring appropriate paths for copying data from a source storage server to a target storage server, and for displaying complex logical path information once the paths are configured. In a particular aspect of the invention, a method for copying data includes displaying a user interface from which a user selects a source storage resource and a target storage resource, and displaying available adapters, via the user interface, through which a path can be established between the selected source storage resource and the selected target storage resource. The user selects at least one of the available adapters, via the user interface, to configure the path to copy data from the selected source storage resource to the selected target storage resource. A related apparatus and program storage device are also provided. BRIEF DESCRIPTION OF THE DRAWINGS These and other features, benefits and advantages of the present invention will become apparent by reference to the following text and figures, with like reference numbers referring to like structures across the views, wherein: FIG. 1 illustrates an overview of storage systems, hosts, and a user interface in a computer system; FIG. 2 illustrates an overview of a logical structure of a dual cluster storage server; FIG. 3 illustrates a method for selecting a path between storage systems; FIG. 4 illustrates a user interface for selecting a path between storage systems, such as an ESCON path; FIG. 5 illustrates a user interface for displaying information regarding a selected path, and confirming a selection; FIG. 6 illustrates a user interface for selecting a path between storage systems, such as a Fibre Channel Protocol (FCP) path; and FIG. 7 illustrates a user interface for displaying path status information. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 illustrates an overview of storage systems, hosts, and a user interface in a computer system. Storage systems 100 and 110, which may be IBM Enterprise Storage Servers (ESSs), for instance, host servers 120 and 130 or other hosts, a user interface 150, and a web server 160, are illustrated in a simplified example. The storage systems 100 and 110 typically can connect to a variety of host servers, which may be servers that store data for different networks. The data of the storage system 100 may be mirrored to another storage system, such as storage system 110, which is typically at a remote site. Communication between the devices may be achieved using any desired communication protocol and medium. The user interface 150 may include a workstation with video screen. The computing resources of the workstation run software to access information in the storage system 100 to generate a display that allows the user to set up source-target pairs of storage resources for copying data, and provides information regarding the status of copying activities in the storage system 100. For example, a distributed application may include a portion running on the user interface 150 and a portion running on a web server 160 that the user interface 150 communicates with. The web server 160, in turn, communicates with the storage system 100. In the example illustrated, the storage system 100 is a source storage system that copies data to the storage system 110 as a target storage system. The web server 160 may communicate with different storage systems to enable the user to configure paths and to provide information regarding the configured paths. The storage system 100 may copy data to the storage system 110 using a switched path or a direct connection (a non-switched path). With a switched path, a switch 115 is provided between the storage systems 100 and 110. The switch 115 may include a number of output ports 116, 117 and 118 as well as input ports, not shown. The storage system 100 configures the path to the storage system 100 by selecting one of the outgoing ports 116, 117 and 118 through which data will travel. For example, a switched path may be provided using serial interfaces at the storage systems 100 and 110 that communicated with the switch 115. IBM's enterprise systems connection (ESCON) card is one possible example. Such a path is typically configured as a unidirectional path, where data is transferred in only one direction at a time. A direct connection may be realized, e.g., via a fiber optic path 122 between the storage systems 100 and 110. For example, IBM's bi-directional Fibre-channel protocol (FCP) for open-systems hosts may be used. A direct connection may also be realized using ESCON. FIG. 2 illustrates an overview of a logical structure of the storage system 100. The example shown relates to the IBM ESS, which includes special features such as redundant storage resources that may not be used in other storage devices. However, the overview is an example only to show one way in which a storage system may connect to other devices and arrange the storage of data internally. The present invention does not require the specific configuration shown, and is suitable for use with other storage devices, as will be apparent to those skilled in the art. The storage system 100 includes two clusters for redundancy. Each cluster includes a cluster processor complex, a cluster cache, and device adapters to connect disk storage resources to the cluster processor complexes. The cluster processor complexes each work independently. Each may contain symmetric multi processors with (volatile) cache, non-volatile storage/cache (NVS), and device adapters (DA). The device adapters, which are installed in pairs, one in each cluster, are used to connect disks to the cluster processor complexes. Each disk array or rank is attached to two DAs. The ranks can be configured as RAID 5 (redundant array of independent disks) or non-RAID arrays. In the ranks, “S” indicates a spare disk and “A” and “B” identify the rank. A host adapter (HA) is a physical subunit of a storage server that provides the ability to attach to one or more host I/O interfaces. The IBM ESS has four HA bays, two in each cluster, and each bay supports up to four host adapters. For example, the storage system 110, host servers 120, 130 and the web server 160 may communicate with the storage system 100 via the HAs. Each HA connects to both cluster processor complexes so that either cluster can handle I/Os from any host adapter. A system adapter identification number (SAID) is a unique identification number automatically assigned to each HA. A mix of various types of host adapters may be supported, such as a small computer systems interface (SCSI) card, which provides two SCSI ports, IBM's ESCON card, which provides two ESCON links, and a fibre-channel card. The fibre-channel card provides one fibre-channel port per HA that supports data transmission over fiber-optic cable using either of two data transmission protocols (not both simultaneously), namely the FCP for open-systems hosts, and the Fibre-connection (FICON) protocol for IBM S/390 or zSeries hosts. FICON is a data-transmission architecture based on the ANSI fibre-channel standard, which supports full-duplex communication. FCP is a protocol with five layers that define how fibre-channel ports interact through their physical links to communicate with other ports. Processing resources in the storage systems 100 and 110 may maintain information regarding a hierarchy of storage resources. At the first, highest level of the hierarchy is the device level, which may include the storage systems 100 and 110 themselves. The second level represents storage resources within a storage system. For example, the storage systems 100 and 110 and hosts 120 and 130 may have logical subsystems (LSSs), which in turn are comprised of volumes, in the third level of the hierarchy. The LSS is a topological construct that includes a group of logical devices such as logical volumes, which may be units of recording medium associated with a logical disk drive. For example, a logical volume in a RAID array may be spread over the disks in the array. The units may include sectors of one or more disks. The storage system 100 employs remote copying, such as peer-to-peer remote copying (PPRC), e.g., to copy data to the storage system 110. PPRC provides synchronous mirroring, and is typically used as a disaster recovery solution. It maintains a consistent copy of a logical volume on the same storage system or on another storage system. All modifications that any attached host performs on the primary logical volume are also performed on the secondary logical volume. A related type of copying, PPRC extended distance, maintains a fuzzy copy of a logical volume on the same storage system, e.g., ESS, or on another storage system. All modifications that any attached host performs on the primary logical volume are also performed on the secondary logical volume at a later point in time. The original order of update is not strictly maintained. Extended remote copying (XRC), e.g., between the storage system 100 and host 120 and 130, provides asynchronous mirroring. It assists a control program to maintain a consistent copy of a logical volume on another storage facility. All modifications of the primary logical volume by any attached host are presented in order to a single host. The host then makes these modifications on the secondary logical volume. XRC is generally used with mainframe host computers. FIG. 3 illustrates a method for selecting a path between storage systems. In one aspect of the invention, a method and user interface are provided for displaying available adapters through which a remote copying path, such as for PPRC, can be established based on source and target system or subsystem selections. In an earlier web user interface (WUI), the user selected an adapter to use in creating a PPRC path after selecting a source subsystem. After that, the user specified the target storage subsystem. However, this procedure did not work for PPRC over Fibre because we needed the source and target subsystem in order to query for the Fibre Channel connectivity. In accordance with the invention, the user supplies the source and target subsystems via the WUI, e.g., user interface 150. Then, we display the possible adapters on which a PPRC or other remote copying path can be established between the source and target subsystems. The user may specify the source and target subsystems used in creating remote copying paths. For example, in one possible approach, the user specifies PPRC over Fibre Channel and ESCON PPRC paths. The user interface 150 displays the possible adapters on which the copying path can be made, given the source and target subsystems specified. This procedure allows the user to configure the paths in a convenient and intuitive manner. The available adapters may be identified by the web server 160 sending a request for available adapters that can connect to a specified target storage resource, when the user interface 150 sends a connectivity request to the web server. In particular, the user specifies the source subsystem with as many parameters as needed to identify it, such as the serial number or other identifier. The same is done for identifying the target subsystem. Then, the user can select which type of remote copying path is desired. For example, PPRC using ESCON or Fibre Channel Protocol may be used. Once the adapter type is defined, the adapters on which a path can be established between the selected source and target subsystems are displayed. The displayed adapters are those that are compatible with the selected path type. Equivalently, the user can select an adapter type. The user can select one of the adapters using any convenient interface device or widget, such as a drop down list. In summary, an example method for selecting a path between storage systems begins at block 300. At block 310, the source storage system is selected. This is the system, sometimes referred to as a subsystem, from which data is to be copied. At block 320, the source logical subsystem from which the data is to be copied is selected. At block 330, the target storage system, to which the data is to be copied, is selected. At block 340, the target logical subsystem to which the data is to be copied, is selected. At block 350, the user selects the adapter type, as needed. At block 360, the available adapters, of a compatible type, and through which a path can be made, are displayed to the user. The process ends at block 370. Note that identification of the source and target storage resources can be tailored to the particular data storage scheme used. A scheme with the storage system and logical subsystem at different hierarchical levels is discussed as an example only. The user interface 150 may use various devices to allow the user to identify the source and target storage resources. For example, the application running at the user interface 150 and web server 160 may display a list of storage systems to the user from which the user selects one as a source system using a checkbox or other device. The source logical subsystem (LSS) can similarly be identified by the user using appropriate interface tools. The target storage system and target LSS can similarly be identified. A technique for displaying path information according to the invention depicts, in one possible implementation, both ESCON and Fibre connections, provides both physical and logical information needed to establish a path between logical subsystems, depicts switched and direct connection path information, and shows end-to-end path information so that the user can easily see source and target logical subsystems for creating paths. A user selects path types “Enterprise Systems Connection” or “Fibre Channel Protocol” (ESCON or FCP, respectively), when establishing paths. Users select a checkbox for one or more (up to eight) desired paths from a list of available paths on a “Select Paths” panel. Paths may be a direct connection or a switched connection between storage systems, for instance. For direct connections, users choose relationships between source and target SAIDs, which identify the adapters. For a switched connection, users must choose the outgoing port (for ESCON) on the switch in addition to source and target SAIDs, or choose the target adapter (for FCP). The user may not continue until a port/adapter is chosen for each switch path selected. Only paths of one type or another (e.g., ESCON or FCP) are displayed. As mentioned, when there is a switch involved, the user can select the target adapter(s) at the target storage resource. Moreover, selecting the target adapter applies to Fibre, whereas for ESCON, we supply the port on the switch. For a given adapter, we display information about the target of a given adapter when viewing adapter status, which could be a port on a switch or an adapter on a storage server such as an ESS. After choosing paths, users can confirm selections made in a “Confirm Selections” panel. Users cannot make changes directly in this panel. Instead, if a user decides to change a selected adapter or adapters, they must go back and reselect the adapter or adapters on a “Select Paths” panel and reconfirm their selections. The solution provided is advantageous since it clearly shows source-to-target relationships for paths in one view. Example user interfaces for implementing the invention are discussed below. The user interfaces may be provided as part of a wizard. FIG. 4 illustrates a user interface 400 for selecting a path, such as an ESCON or other unidirectional path, between storage systems. As noted, the user interface 400 may be provided as part of a wizard. Prior to this panel, the user would have selected the source storage resource, such as a source ESS/LSS, a target storage resource, such as a target ESS/LSS and the adapter or path type, such as ESCON or FCP. In the interface 400, the user can select a desired path or paths based on previous choices. After the user selects a path or paths, a confirm selections panel is displayed (such as the interface 500 of FIG. 5). The confirm selections panel is suitable for use with different adapter types, and thus may apply to the case where an FCP adapter or other adapter type is used as well. In the first row of the user interface 400, under the legend “Source”, the source storage resource is identified by a serial number of the source storage server or ESS, which is “16277”, an identifier of an LSS, which is “22”, and a SAID. The system adapter identification number (SAID) is a unique identification number assigned to a host adapter used by the source storage resource. Under the legend “Path”, a switch is identified by the identifier “0000016277”, and a drop down menu can be used to select a switch port. For example, referring to FIG. 1, one of the output ports 116, 117 and 118 of the switch 115 may be selected. A port identified by “0:00” is displayed in the confirmation panel of FIG. 5. Under the legend “Target”, the target storage resource is identified by a serial number of the source ESS, which is “16496”, and an identifier of an LSS, which is “18”, and a SAID. In the second row of the user interface 400, similar information regarding the source and target resources is provided for a direct connection that has been configured. Note that both the overall path status view and the path information in the wizards, including the list of available adapters and/or switch ports, can be dynamically updated. The user will see an “Alert” column in the establish path wizard panels for both ESCON and FCP. In particular, an Alert column to the right of the path selection area alerts the users to 1) whether or not a path currently has PPRC paths (represented by a “paths established” icon), and 2) whether or not a path has failed (represented by an “error” icon). The icons in the alert column are clickable, and users can obtain additional information on paths established or paths that have failed. Users do not need to make any changes in response to path alert items before proceeding in the wizard. Regarding the dynamic updating of the path status on the adapter, let's say an adapter has a good path going through it. Then, for some reason, the path fails. We want to populate this up to the user interface to inform the user that the path in question is faulty. This path status is displayed for an adapter, given that an adapter can have various paths going through it. Also, a new path could have been established through a given adapter, and we want to display this in the user interface. Another possibility is that the adapter gets reconfigured to a protocol that is not handled. Therefore, we have to remove that adapter from the list of available adapters. FIG. 5 illustrates a user interface 500 for displaying information regarding a configured path, and confirming a selection. The interface 500 may reflect selections made via the interface 400, for example. In the first row, the interface 500 displays the selected switch and port identifiers. In the second row, the interface 500 indicates that a direct connection has been selected. FIG. 6 illustrates a user interface for selecting a path, such as a Fibre Channel Protocol (FCP) or other bi-directional path, between storage systems. The wizard for establishing an FCP path may have the same flow as the one for establishing an ESCON path. In the first row of the user interface 600, under the legend “Source”, the source storage resource is identified as discussed in connection with FIG. 4. The target storage resource is identified by a serial number of the source server or ESS, which is “16496”, and an identifier of an LSS, which is “18”. Under the legend “Path”, the interface 600 denotes that a switched path is selected, and a drop down menu can be used to select an adapter. Any identifier, such as the SAID, can be used for the adapters. In accordance with the invention, the available and compatible adapters are displayed, based on the designated source and target storage resources, and the path/adapter type, to assist the user in the selection process. For example, assume there are sixteen adapters total at the source storage resource, with identifiers SAID 1, . . . , SAID 16. Assume further that SAID 1 through SAID 8 are compatible with a first path type such as ESCON, and SAID 9 through SAID 16 are compatible with a second path type such as FCP. Also assume that SAID 9 through SAID 12 are currently in use for other paths or are otherwise unavailable. Then, the interface 600 will inform the user, via the drop down menu, that SAID 13 through SAID 16 are available for establishing an FCP path. The second row of the interface denotes that a direct connection is made, in which case the user does not need to select an adapter. The target for the direct connection is also identified. Once the selections are made via the interface 600, a confirmation panel analogous to the interface 500 may appear to confirm the selections and display the relevant information regarding the configured paths. FIG. 7 illustrates a user interface 700 for displaying path status information. The interface 700 can be selected at any time, such as by highlighting the “Paths” selection in the hierarchical tree display on the left hand side of the interface 700. In the tree display, the storage server or ESS is at the top of the tree. The serial number of a particular ESS, e.g., “16277” is provided at the second level. The third level provides the “Paths” node and LSS nodes. A “Status” region of the interface 700 provides information regarding one or more remote copying operations. A first row indicates that an FCP path from the ESS “16277” to a target resource (ESS) with an identifier “18740” has been established. A second row indicates that an ESCON path from the ESS “16277” to a target resource (ESS) with an identifier “18554” has been established. The field “Value” identifies the SAID number. The field “ESCON” identifies the number of ESCON paths. The field “FCP” identifies the number of FCP paths. The field “PPRC Paths” identifies the number of total PPRC paths. The invention has been described herein with reference to particular exemplary embodiments. Certain alterations and modifications may be apparent to those skilled in the art, without departing from the scope of the invention. The exemplary embodiments are meant to be illustrative, not limiting of the scope of the invention, which is defined by the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The invention relates generally to the field of data storage in computer systems and, more specifically, to a copy services user interface for a storage subsystem for representing complex logical path information, and for displaying available adapters through which a remote copying path can be established. 2. Description of the Related Art Computer storage devices such as storage servers have high-capacity disk arrays to backup data from external host systems, such as host servers. For example, a large corporation or other enterprise may have a network of servers that each store data for a number of workstations used by individual employees. Periodically, the data on the host servers is backed up to the high-capacity storage server to avoid data loss if the host servers malfunction. A storage server may also backup data from another storage server, such as at a remote site, in a peer-to-peer copying operation. The storage servers are also known to employ redundant systems to provide additional safeguards against data loss. The IBM Enterprise Storage Server (ESS) is an example of a storage server. However, it is often difficult for the user to configure appropriate paths for copying data from a source storage server to a target storage server, and to ascertain complex logical path information once the paths are configured. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>To address these and other issues, the present invention describes a method and system for assisting a user in configuring appropriate paths for copying data from a source storage server to a target storage server, and for displaying complex logical path information once the paths are configured. In a particular aspect of the invention, a method for copying data includes displaying a user interface from which a user selects a source storage resource and a target storage resource, and displaying available adapters, via the user interface, through which a path can be established between the selected source storage resource and the selected target storage resource. The user selects at least one of the available adapters, via the user interface, to configure the path to copy data from the selected source storage resource to the selected target storage resource. A related apparatus and program storage device are also provided. | 20040225 | 20080325 | 20050825 | 66857.0 | 0 | SUN, SCOTT C | USER INTERFACE FOR REPRESENTING LOGICAL PATH INFORMATION AND DISPLAYING AVAILABLE ADAPTERS IN A STORAGE SUBSYSTEM | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,787,219 | ACCEPTED | Methods for obtaining thermostable enzymes, DNA polymerase I variants from Thermus aquaticus having new catalytic activities, methods for obtaining the same, and applications of the same | The present invention provides a method for obtaining thermostable enzymes. The present invention also provides variants of DNA polymerase I from Thermus aquaticus. The present invention further provides methods of identifying mutant DNA polymerases having enhanced catalytic activity. The present invention also provides polynucleotides, expression systems, and host cells encoding the mutant DNA polymerases. Still further, the present invention provides a method to carry out reverse transcriptase-polymerase chain reaction (RT-PCR) and kits to facilitate the same. | 1. A purified polynucleotide which encodes a thermostable polypeptide comprising an amino acid sequence having at least 80% identity to SEQ ID NO: 26, wherein said polypeptide has at least one mutation in amino acids 738 to 767 of SEQ ID NO:26, or at a position selected from the group consisting of A331, L332, D333, Y334, S335, M470, F472, M484, W550, L332, D333, and Y334, and wherein said polypeptide has DNA polymerase activity. 2. The purified polynucleotide of claim 1, wherein said at least one mutation is selected from the group consisting of A331T, S335N, M470K, M470R, F472Y, M484V, M484T, and W550R. 3. The purified polynucleotide of claim 1, wherein said polypeptide has at least 90% identity to SEQ ID NO: 26. 4. The purified polynucleotide of claim 1, wherein said polypeptide has at least 95% identity to SEQ ID NO: 26. 5. The purified polynucleotide of claim 1, wherein said polypeptide has at least 97.5% identity to SEQ ID NO: 26. 6. The purified polynucleotide of claim 1, wherein said polypeptide comprises at least two mutations. 7. The purified polynucleotide of claim 1, wherein said polypeptide has an amino acid sequence selected from the group consisting of SEQ ID NO: 20, SEQ ID NO: 22, SEQ ID NO: 24, SEQ ID NO: 28, SEQ ID NO: 30, SEQ ID NO: 32, SEQ ID NO: 34, SEQ ID NO: 36, and SEQ ID NO: 38. 8. The purified polynucleotide of claim 7, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 20. 9. The purified polynucleotide of claim 7, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 22. 10. The purified polynucleotide of claim 7, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 24. 11. The purified polynucleotide of claim 7, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 28. 12. The purified polynucleotide of claim 7, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 30. 13. The purified polynucleotide of claim 7, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 32. 14. The purified polynucleotide of claim 7, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 34. 15. The purified polynucleotide of claim 7, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 36. 16. The purified polynucleotide of claim 7, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 38. 17. The purified polynucleotide of claim 1, wherein said polynucleotide has a sequence selected from the group consisting of SEQ ID NO: 19, SEQ ID NO: 21, SEQ ID NO: 23, SEQ ID NO: 27, SEQ ID NO: 29, SEQ ID NO: 31, SEQ ID NO: 33, SEQ ID NO: 35, and SEQ ID NO: 37. 18. A purified polynucleotide that is complementary to the polynucleotide of claim 1. 19. A purified polynucleotide which hybridizes under stringent conditions to the polynucleotide of claim 1; wherein said stringent conditions comprise washing in 5×SSC at a temperature from 50 to 68° C. 20. A vector comprising the purified polynucleotide of claim 1. 21. The vector of claim 20, wherein said polynucleotide is operably linked to a heterologous expression sequence. 22. A host cell comprising the purified polynucleotide of claim 1. 23. A purified thermostable polypeptide comprising an amino acid sequence having at least 80% identity to SEQ ID NO: 26, wherein said polypeptide has at least one mutation in amino acids 738 to 767 of SEQ ID NO:26, or at a position selected from the group consisting of A331, L332, D333, Y334, S335, M470, F472, M484, W550, L332, D333, and Y334, and wherein said polypeptide has DNA polymerase activity. 24. The purified polypeptide of claim 22, wherein said at least one mutation is selected from the group consisting of A331T, S335N, M470K, M470R, F472Y, M484V, M484T, and W550R. 25. The purified polypeptide of claim 23, wherein said polypeptide has at least 90% identity to SEQ ID NO: 26. 26. The purified polypeptide of claim 23, wherein said polypeptide has at least 95% identity to SEQ ID NO: 26. 27. The purified polypeptide of claim 23, wherein said polypeptide has at least 97.5% identity to SEQ ID NO: 26. 28. The purified polypeptide of claim 23, wherein said polypeptide wherein said polypeptide comprises at least two mutations. 29. The purified polypeptide of claim 23, wherein said polypeptide has an amino acid sequence selected from the group consisting of SEQ ID NO: 20, SEQ ID NO: 22, SEQ ID NO: 24, SEQ ID NO: 28, SEQ ID NO: 30, SEQ ID NO: 32, SEQ ID NO: 34, SEQ ID NO: 36, and SEQ ID NO: 38. 30. The purified polypeptide of claim 29, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 20. 31. The purified polypeptide of claim 29, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 22. 32. The purified polypeptide of claim 29, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 24. 33. The purified polypeptide of claim 29, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 28. 34. The purified polypeptide of claim 29, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 30. 35. The purified polypeptide of claim 29, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 32. 36. The purified polypeptide of claim 29, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 34. 37. The purified polypeptide of claim 29, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 36. 38. The purified polypeptide of claim 29, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 38. 39. A kit for amplifying DNA comprising: a purified thermostable polypeptide, wherein said polypeptide has at least 80% homology to SEQ ID NO: 26, wherein said polypeptide has at least one mutation in amino acids 738 to 767 of SEQ ID NO:26, or at a position selected from the group consisting of A331, L332, D333, Y334, S335, M470, F472, M484, W550, L332, D333, and Y334, and wherein said polypeptide has DNA polymerase activity; a concentrated buffer solution, and optionally one or more divalent metal ions; and a mixture of deoxyribonucleotides. 40. The kit of claim 39, wherein said at least one mutation is selected from the group consisting of A331T, S335N, M470K, M470R, F472Y, M484V, M484T, and W550R. 41. The kit of claim 39, wherein said divalent metal ion is Mg2+ or Mn2+. 42. The kit of claim 39, wherein said polypeptide has at least 90% identity to SEQ ID NO: 26. 43. The kit of claim 39, wherein said polypeptide has at least 95% identity to SEQ ID NO: 26. 44. The kit of claim 39, wherein said polypeptide has at least 97.5% identity to SEQ ID NO: 26. 45. The kit of claim 39, wherein said polypeptide comprises at least two mutations. 46. The kit of claim 39, wherein said polypeptide has an amino acid sequence selected from the group consisting of SEQ ID NO: 20, SEQ ID NO: 22, SEQ ID NO: 24, SEQ ID NO: 28, SEQ ID NO: 30, SEQ ID NO: 32, SEQ ID NO: 34, SEQ ID NO: 36, and SEQ ID NO: 38. 47. The kit of claim 46, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 20. 48. The kit of claim 46, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 22. 49. The kit of claim 46, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 24. 50. The kit of claim 46, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 28. 51. The kit of claim 46, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 30. 52. The kit of claim 46, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 32. 53. The kit of claim 46, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 34. 54. The kit of claim 46, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 36. 55. The kit of claim 46, wherein said polypeptide has the amino acid sequence of SEQ ID NO: 38. 56. The kit of claim 39, further comprising a 5′ to 3′ exonuclease or a 3′ to 5′ exonuclease. 57. The kit of claim 56, wherein said 5′ to 3′ exonuclease has SEQ ID NO: 50. 58. The kit of claim 56, wherein said 3′ to 5′ exonuclease has SEQ ID NO: 51. 59. A method for reverse transcribing an RNA comprising: a) providing a reverse transcription reaction mixture comprising said RNA, a primer, a divalent cation, and a purified thermostable polypeptide comprising an amino acid sequence having at least 80% identity to SEQ ID NO: 26, wherein said polypeptide has at least one mutation in amino acids 738 to 767 of SEQ ID NO:26, or at a position selected from the group consisting of A331, L332, D333, Y334, S335, M470, F472, M484, W550, L332, D333, and Y334, and wherein said polypeptide has DNA polymerase activity; and b) treating said reaction mixture at a temperature and under conditions suitable for said purified polypeptide to initiate synthesis of an extension product of said primer to provide a cDNA molecule complementary to said RNA. 60. The method of claim 59, wherein said at least one mutation is selected from the group consisting of A331T, S335N, M470K, M470R, F472Y, M484V, M484T, and W550R. 61. A method of identifying thermostable mutant polypeptides comprising a) packaging a vector in which a polynucleotide encoding a phage coat protein is fused to a polynucleotide encoding a protein having at least 80% identity to SEQ ID NO: 26 into a phage; b) expressing the fusion protein; c) isolation of phage particles; d) infecting E. coli and incubating the infected E. coli; e) detecting the fusion protein; f) assessing polymerase activity. 62. The method of claim 61, wherein (b)-(f) are repeated 0 to 25 times. 63. The method of claim 61, wherein the phage coat protein is SEQ ID NO: 39. 64. A method of identifying thermostable mutant polypeptides having a catalytic activity comprising: a) packaging a vector in which a gene or fragment thereof encoding variants of a catalytic domain responsible for the catalytic activity fused to a gene encoding a phage coat protein; b) isolation and purification of phage particles; c) heating the phage-mutant polypeptide at a temperature ranging from 50° C. to 90° C. for a time ranging from 30 seconds to several hours; d) cross-linking a specific substrate with a phage particle; e) forming a reaction product from the substrate catalyzed by the thermostable mutant protein on phage, wherein the temperature is optionally regulated to be the same or greater or lower than the temperature of (c) f) selecting the phage particles comprising a variant nucleotidic sequence encoding for the catalytic domain responsible for the catalytic activity at the regulated temperature, by capturing the reaction product or screening for said reaction product, g) infecting E. coli with the phage particles selected at step (f), h) incubating the infected E. coli; and i) assessing catalytic activity of the proteins corresponding to isolated genes. 65. The method of claim 64, wherein the gene or fragment thereof encoding variants of a catalytic domain is directly fused to the gene encoding a phage coat protein. 66. The method of claim 64, wherein the steps (a) to (h) are repeated 0 to 20 times. 67. The method of claim 64, wherein the gene or fragment thereof encoding variants of a catalytic domain and the gene encoding a phage coat protein, are indirectly fused by a peptide or polypeptide linker. 68. The method of claim 67, wherein the peptide is selected from the group consisting of: a glycine rich linker such as (SG4)n (SEQ ID NO: 39), a human calmodulin (SEQ ID NO: 46), and a hexahistidine binding single chain variable fragment consisting of (i) an anti-His Tag Antibody 3D5 Variable Heavy Chain (SEQ ID NO: 47) (ii) a linker (SEQ ID NO: 48) (iii) an anti-His Tag Antibody 3D5 Variable Light Chain (SEQ ID NO: 49). 69. The method of claim 67, wherein the polypeptide linker is selected from the group consisting of: a protein binding the substrate at high temperature a catalytic domain of a 5′ to 3′ exonuclease a catalytic domain of a 3′ to 5′ a catalytic domain of Bacillus circulans cyclodextringlycosyltransferase (SEQ ID NO: 52), a catalytic domain of Bordetella pertussis adenylate cyclase(SEQ ID NO: 53) a Bacillus amyloliquefaciens serine protease subtilisin (SEQ ID NO: 54), and a catalytic domain of Bacillus subtilis lipase A (SEQ ID NO: 55). 70. The method of claim 64, wherein the cross-linking between the specific substrate of the catalytic domain of the polypeptide with the phage particule is made by a cross-linking agent selected from the group consisting of a: maleimidyl group iodoacetyl group disulfide derivative and any other thermostable link. 71. The method of claim 64, wherein the catalytic domain is the catalytic domain of an enzyme selected from the group consisting of a: DNA polymerase, alpha-amylase, lipase, protease, a cyclodextringlycosyltransferase, and an adenylate cyclase. 72. The method of claim 64, wherein the assessment of the catalytic activity of (f) is made by means of a DNA polymerization. 73. The method of claim 64, wherein (b) is performed after (e) or during (h). 74. The method of claim 64, wherein the temperature in (e) is regulated to be the same or greater than the temperature of (c). 75. The method of claim 64, wherein the temperature in (e) is regulated to be the same or less than the temperature of (c). 76. A method of obtaining a thermostable variant enzyme comprising: a) screening enzymes expressed at the surface of phage particles and identifying at least a thermostable variant conserving its active; catalytic domain at regulated temperature according to the method of claim 61, b) isolating and sequencing a DNA encoding said identified thermostable variant; c) preparing a vector comprising the DNA of step (b); d) transfecting or infecting cells with the vector obtained at step c); e) expressing the thermostable variant enzyme from the cells and optionally, f) recovering, isolating and purifying said thermostable variant enzyme expressed at step (e). 77. A method of obtaining a thermostable variant enzyme comprising: a) screening enzymes expressed at the surface of phage particles and identifying at least a thermostable variant conserving its active; catalytic domain at regulated temperature according to the method of claim 69, b) isolating and sequencing a DNA encoding said identified thermostable variant; c) preparing a vector comprising the DNA of step (b); d) transfecting or infecting cells with the vector obtained at step c); e) expressing the thermostable variant enzyme from the cells and optionally, f) recovering, isolating and purifying said thermostable variant enzyme expressed at step (e). 78. An insert contained in a phage selected from the group consisting of I-3168, I-3169,I-3170, I-3171, I-3172, I-3173, I-3174, I-3175, and I-3176 deposited in CNCM on Feb. 27, 2004 under the number. 79. A recombinant host cell comprising an insert or a polynucleotide encoding a thermostable polymerase according claim 78. | CROSS-REFERENCE TO RELATED APPLICATIONS Not Applicable. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a method for obtaining thermostable enzymes. The present invention also provides variants of DNA polymerase I from Thermus aquaticus. The present invention further provides methods of identifying mutant DNA polymerases having enhanced catalytic activity. The present invention also provides polynucleotides, expression systems, and host cells encoding the mutant DNA polymerases. Still further, the present invention provides a method to carry out reverse transcriptase-polymerase chain reaction (RT-PCR) and kits to facilitate the same. 2. Discussion of the Background Filamentous phage display is commonly used as a method to establish a link between a protein expressed as a fusion with a phage coat protein and its corresponding gene located within the phage particle (Marks et al., J. Biol. Chem. (1992) 267, 16007-16010). The use of filamentous phage particles as a chemical reagent provides further a strategy to create a complex between an enzyme, its gene and a substrate (Jestin et al., Angew. Chem. Int. Ed. (1999) 38, 1124-1127). This substrate can be cross-linked on the surface of filamentous phage using the nucleophilic properties of coat proteins. If the enzyme is active, conversion of the substrate to the product yields a phage particle cross-linked with the product, which can be captured by affinity chromatography (see discussion in Vichier-Guerre & Jestin, Biocat. & Biotransf. (2003) 21, 75-78). Several similar approaches based on product formation for the isolation of genes encoding enzymes using phage display have been described in the literature for various enzymes (Fastrez et al., (2002) In: Brackmann, S. and Johnsson, K. eds., Directed Molecular Evolution of Proteins (Wiley VCH, Weinheim), pp 79-110). These in vitro selections of proteins for catalytic activity are well suited for use with large repertoires of about 108 proteins or more. Several libraries of enzyme variants on phage have been constructed and catalytically active proteins with wild type like activities have been isolated (Atwell & Wells (1999) Proc. Natl. Acad. Sci. USA 96, 9497-9502; Heinis et al. (2001) Prot. Eng. 14, 1043-1052; Ponsard et al. (2001) Chembiochem. 2, 253-259; Ting et al. (2001) Biopol. 60, 220-228.). Mutants with different substrate specificities have been also obtained (Xia et al. (2002) Proc. Natl. Acad. Sci. USA 99, 6597-6602.). In these studies, the fraction of active variants in the libraries can be large and it remains unclear how rare an enzyme can be in the initial protein library so as to be selected after iterative selection cycles. Accordingly, there remains a critical need for an efficient process for making and identifying thermostable enzymes possessing a desired catalytic activity. Reverse transcriptases are enzymes that are present generally in certain animal viruses (i.e., retroviruses), which are used in vitro to make complementary DNA (cDNA) from an mRNA template. Practically, reverse transcriptases have engendered significant interest for their use in reverse transcriptase-polymerase chain reaction (RT-PCR). As such, these proteins lend themselves to be a model system for development of an efficient method of making thermostable enzymes having a desired activity. RNA generally contains secondary structures and complex tertiary sections, accordingly it is highly desired that the RNA be copied in its entirety by reverse transcription to ensure that integrity of cDNA is maintained with high accuracy. However, due to the often complicated secondary and tertiary structures of RNA, the denaturation temperatures are generally about 90° C. and, as such, the reverse transcriptase must be capable of withstanding these extreme conditions while maintaining catalytic efficiency. The classically utilized enzymes for RT-PCR have been isolated from the AMV (Avian myeloblastosis virus) or MMLV (Moloney murine leukemia virus); however, these enzymes suffer from a critical limitation in that they are not thermostable. In fact, the maximum temperature tolerated by most commercially available reverse transcriptases is about 70° C. One common approach to overcome this limitation in the existing technology with the previously described polymerases has been the use of a protein chaperones in addition to the polymerase. However, this method leads to problems associated with environmental compatibility metal ion requirements, multi-stage procedures, and overall inconvenience. Accordingly, an alternative strategy has been to use thermostable reverse transcriptases. This approach makes it possible to perform multiple denaturation and reverse transcription cycles using only a single enzyme. To this end, the DNA-dependent DNA polymerase I of Thermus aquaticus (i.e., Taq polymerase), is thermostable and has reverse transcriptase activity only in the presence of manganese. However, when the manganese ion concentration is maintained in the millimolar range the fidelity of the enzyme is affected. It has been suggested that the thermostable DNA-dependent DNA polymerase of Bacillus stearothermophilus has reverse transcriptase activity, even in absence of magnesium, but in this case it is necessary to add a thermostable DNA polymerase for the PCR. Therefore, there remains a critical need for high efficiency, thermostable enzymes that are capable of catalyzing reverse transcription and subsequent DNA polymerization in “one-pot” RT-PCR. Accordingly, the present invention provides an isolated population of thermostable reverse transcriptases, which are active in absence of manganese, by directed evolution of the Stoffel fragment of the Taq polymerase. SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of identifying thermostable mutant polypeptides having a catalytic activity by: a) packaging a vector in which a gene or fragment thereof encoding variants of a catalytic domain responsible for the catalytic activity fused to a gene encoding a phage coat protein, b) isolation and purification of phage particles; c) heating the phage-mutant polypeptide at a temperature ranging from 50° C. to 90° C. for a time ranging from less than 1 minute to several hours d) cross-linking a specific substrate with a phage particle e) forming a reaction product from the substrate catalyzed by the thermostable mutant protein on phage, wherein the temperature is optionally regulated to be the same or greater or lower than the temperature of (c) f) selecting the phage particles comprising a variant nucleotidic sequence encoding for the catalytic domain responsible for the catalytic activity at the regulated temperature, by capturing the reaction product or screening for said reaction product, g) infecting E. coli with the phage particles selected at step (f), h) incubating the infected E. coli; and i) assessing catalytic activity of the proteins corresponding to isolated genes. It is an object of the present invention to provide a thermostable mutant DNA polymerase having at least 80% homology to the Stoffel fragment (SEQ ID NO: 26) of DNA polymerase I obtained from Thermus aquaticus. To this end, the present invention provides thermostable polypeptides having at least 80% homology to SEQ ID NO: 26, wherein said polypeptide has at least one mutation selected from the group consisting of a mutation in amino acids 738 to 767 of SEQ ID NO:26, A331T, S335N, M470K (position 747 of the Taq polymerase wild-type sequence), M470R (position 747 of the Taq polymerase wild-type sequence), F472Y (position 749 of the Taq polymerase wild-type sequence), M484V (position 761 of the Taq polymerase wild-type sequence), M484T (position 761 of the Taq polymerase wild-type sequence), and W550R (position 827 of the Taq polymerase wild-type sequence), and wherein said polypeptide has improved DNA polymerase activity and retains 5′-3′ exonuclease activity. In an object of the present invention, the 3′-5′ exonuclease activity of the mutant polypeptide is inactive. In an object of the present invention, the thermostable mutant DNA polymerase also has a mutation at one or more position selected from A331, L332, D333, Y334, and S335 of SEQ ID NO: 26 (positions 608-612 of the Taq polymerase wild-type sequence). In a particular object of the present invention, the mutant DNA polymerase has one of the following sequences: SEQ ID NO: 20, SEQ ID NO: 22, SEQ ID NO: 24, SEQ ID NO: 28, SEQ ID NO: 30, SEQ ID NO: 32, SEQ ID NO: 34, SEQ ID NO: 36, and SEQ ID NO: 38. Further, in another object of the present invention are polynucleotides that encode for the aforementioned thermostable mutant DNA polymerases. In yet another object of the present invention is a kit for DNA amplification, which contains: (a) one or more of the aforementioned thermostable mutant DNA polymerases; (b) a concentrated buffer solution, wherein when said concentrated buffer is admixed with the isolated polypeptide the overall buffer concentration is 1×; (c) one or more divalent metal ion (e.g., Mg2+ or Mn2+); and (d) deoxyribonucleotides. In yet another object of the present invention is a method of reverse transcribing an RNA by utilizing the inventive thermostable mutant DNA polymerases. In still a further object of the present invention is a phage-display method for identifying thermostable mutant DNA polymerases in which the Stoffel fragment has been mutated, while the DNA polymerase activity and 5′-3′ exonuclease activity has been maintained and/or enhanced. The above objects highlight certain aspects of the invention. Additional objects, aspects and embodiments of the invention are found in the following detailed description of the invention. BRIEF DESCRIPTION OF THE FIGURES A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following Figures in conjunction with the detailed description below. FIG. 1 shows the reverse transcriptase activity of phage-polymerases assessed as obtained after different rounds of selection in the presence of Mg2+ or Mn2+ ions. The lane labels correspond to the following: MnCl2 MgCl2 a: phage-polymerases of round 6 h: phage-polymerases of round 6 b: phage-polymerases of round 5 i: phage-polymerases of round 5 c: phage-polymerases of round 4 j: phage-polymerases of round 4 d: phage-polymerases of round 3 k: phage-polymerases of round 3 e: phage-polymerases of round 2 l: phage-polymerases of round 2 f: phage-polymerases of round 1 m: phage-polymerases of round 1 g: phage-polymerases of initial n: phage-polymerases of initial population population FIG. 2 shows the reverse transcriptase activity of phage-polymerases assessed as obtained after different rounds of selection in the presence of Mg2+ ions. The lane designations in FIG. 2 are as follows: Phage-polymerase heated Phage-polymerase not at 65° C. for 5 min. preheated a: phage-polymerases of initial h: phage-polymerases of initial population population b: phage-polymerases of round 1 i: phage-polymerases of round 1 c: phage-polymerases of round 2 j: phage-polymerases of round 2 d: phage-polymerases of round 3 k: phage-polymerases of round 3 e: phage-polymerases of round 4 l: phage-polymerases of round 4 f: phage-polymerases of round 5 m: phage-polymerases of round 5 g: phage-polymerases of round 6 n: phage-polymerases of round 6 o: control AMV-RT, 1 U p: control AMV-RT, 0.1 U q: control AMV-RT, 0.01 U r: control AMV-RT, 0.001 U FIG. 3 shows the reverse transcriptase activity of various monoclonal phage-polymerases obtained after round 6 in the presence of Mg2+ ions. The lane designations in FIG. 3 are as follows: s=SEQ ID NO: 38; a=SEQ ID NO: 20; d=SEQ ID NO: 24; g=SEQ ID NO: 28; C=AMV-RT; i=SEQ ID NO: 30; m=SEQ ID NO: 32; n=SEQ ID NO: 34; b=SEQ ID NO: 22; and q=SEQ ID NO: 36. FIG. 4 shows the reverse transcriptase activities and the polymerase activities of monoclonal phage-polymerases obtained after the round 6 in the presence of Mg2+ or Mn2+ ions. The lane designations in FIG. 4 are as follows: a=SEQ ID NO: 20; b=SEQ ID NO: 22; d=SEQ ID NO: 24; and e=SEQ ID NO: 26. FIG. 5 shows purified mutant RT-polymerases a, b, and d used in polymerase chain reaction. The lanes in the gel appearing in FIG. 5 include the three clones corresponding on clones a, b and d on FIG. 4. In addition, the positive control was performed using the Stoffel fragment polymerase e and commercially Taq polymerase (Promega). The lanes in FIG. 5 are as follows: lane 1: Taq lane 2: a=SEQ ID NO: 20 lane 3: b=SEQ ID NO: 22 lane 4: d=SEQ ID NO: 24 lane 5: e=SEQ ID NO: 26 lane 6: Molecular weight marker FIG. 6 shows purified mutant RT-polymerases a, b, and d used in RT-polymerase chain reaction. The lanes in the gel appearing in FIG. 6 include the three clones corresponding to clones a, b and d on FIG. 4. In addition, the positive control was performed using the Stoffel fragment polymerase e and the phage-polymerase of AMV-RT (Promega). The lanes in FIG. 6 are as follows: lane 1: molecular weight marker lane 2: control AMV-RT lane 3: b=SEQ ID NO: 22 lane 4: a=SEQ ID NO: 20 lane 5: e=SEQ ID NO: 26 lane 6: d=SEQ ID NO: 24 DETAILED DESCRIPTION OF THE INVENTION Unless specifically defined, all technical and scientific terms used herein have the same meaning as commonly understood by a skilled artisan in enzymology, biochemistry, cellular biology, molecular biology, and the medical sciences. All methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, with suitable methods and materials being described herein. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. Further, the materials, methods, and examples are illustrative only and are not intended to be limiting, unless otherwise specified. The present invention provides a method of identifying thermostable mutant polypeptides having a catalytic activity comprising: a) packaging a vector in which a gene or fragment thereof encoding variants of a catalytic domain responsible for the catalytic activity fused to a gene encoding a phage coat protein, b) isolation and purification of phage particles; c) heating the phage-mutant polypeptide at a temperature ranging from 50° C. to 90° C., preferably from 55° C. to 65° C., more preferably at 65° C. for a time ranging from 30 seconds to several hours, preferably from 1 minute to 3 hours, more preferably from 5 minutes to 2 hours, most preferably 10 minutes to 1 hour d) cross-linking a specific substrate with a phage particle e) forming a reaction product from the substrate catalyzed by the thermostable mutant polypeptide on phage, wherein the temperature is optionally regulated to be the same or greater or lower than the temperature of (c) (i.e., from 25° C. to 70° C., preferably from 37° C. to 70° C. and more preferably at 65° C.). f) selecting the phage particles comprising a variant nucleotidic sequence encoding for the catalytic domain responsible for the catalytic activity at the regulated temperature, by capturing the reaction product or screening for said reaction product, g) infecting E. coli with phage particles selected at (f) h) incubating the infected E. coli; and i) assessing catalytic activity of the proteins corresponding to isolated genes. In the embodiment above, the gene or fragment thereof encoding variants of a catalytic domain may be directly or indirectly fused to the gene encoding a phage coat protein. When the gene or fragment thereof encoding variants of a catalytic domain and the gene encoding a phage coat protein are indirectly fused it is preferred that the fusion be through a peptide or polypeptide linker. Within this above-recited embodiment, steps (a) to (h) may be repeated 0 to 20 times, preferably 1 to 15 times, more preferably 2 to 10 times, most preferably 3 to 7 times The method comprising a single cycle (repeated 0 times) is particularly adapted to high throughput screening, when steps are repeated from 3 to 7 times, the method is better adapted for classical empirical screening. The peptide utilized within this embodiment is selected from the group consisting of: a flexible linker such as a glycine rich linker such as (SG4)n (SEQ ID NO: 39), Human calmodulin (SEQ ID NO: 46, the DNA encoding SEQ ID NO:46 is SEQ ID NO:56), and Hexahistidine binding single chain variable fragment (Grütter M. G., J. Mol. Biol. 2002, 318, 135-147.) consisting of (i) Anti-His Tag Antibody 3D5 Variable Heavy Chain (SEQ ID NO: 47) (ii) Linker (SEQ ID NO: 48) (iii) Anti-His Tag Antibody 3D5 Variable Light Chain (SEQ ID NO: 49). Moreover, the polypeptide linker is selected from the group consisting of: any protein binding the substrate at high temperature, any catalytic domain such as exonuclease 5′ to 3′ (from Thermus thermophilus, SEQ ID NO: 50), or 3′ to 5′(from E. coli, SEQ ID NO: 51), Catalytic domain of Bacillus circulans cyclodextringlycosyltransferase (SEQ ID NO: 52, the DNA is in SEQ ID NO:57), Catalytic domain of Bordetella pertussis adenylate cyclase(SEQ ID NO: 53-the DNA is in SEQ ID NO:58), Bacillus amyloliquefaciens serine protease subtilisin (SEQ ID NO: 54—the DNA is in SEQ ID NO:59), and Catalytic domain of Bacillus subtilis lipase A (SEQ ID NO: 55, Quax W. J. 2003, 101, 19-28 J Biotechnol.). As used in the present invention, the cross-linking between the specific substrate of the catalytic domain of the polypeptide with the phage particle is made by a cross-linking agent selected from the group consisting of a: maleimidyl group, iodoacetyl group, disulfide derivative and any other thermostable link (conducting to a stable protein-protein interaction or protein-molecule interaction). In a preferred embodiment, the catalytic domain may be the catalytic domain of an enzyme selected from the group consisting of: a polymerase, an alpha-amylase (substrate such as starch), a lipase (substrate such as ester), a protease (modified or not modified peptide or polypeptide as substrate), a cyclodextringlycosyltransferase, and an adenylate cyclase. In another embodiment, the assessment of the catalytic activity of step (f) is made by means of a DNA polymerization. In yet another embodiment of the present invention, step (b) may be performed after (e) of cross-linking or during (h) of assesing catalytic activity. As a general method for the isolation of thermostable enzymes and their genes the following should be noted: First, the gene encoding variants of a catalytic domain are fused to the gene encoding a phage coat protein (such as filamentous phage g3, g6, g7, g9 or g8 protein or of other phage/virus particles) either directly or using a peptide or polypeptide linker such as a short peptide sequence or a protein or a protein domain. These genes encoding phage coat proteins may be fused either at the 3′ or at the 5′ terminus depending on whether the N- or the C-termini of the proteins are located on the outside of the particle. This is done either using a phage vector or a phagemid vector used with a helper phage. Second, the phage-variant enzymes may be heated at a preferred temperature of 65° C. for 1 minute or for several hours as appropriate. This step can be performed before or after the substrate cross-linking (maleimidyl group derivatised substrate (DNA primer) crosslinked to the phage particle) and catalysis (DNA polymerisation) steps. Catalysis is preferably at 65° C. for 2 minutes, but can be done at any temperature between 0° C. and 100° C. Crosslinking is typically performed for 2 hours at 37° C., but can be done at other temperatures (higher temperature may increase maleimidyl hydrolysis versus maleimidyl phage cross-linking). It is worth noting that the link between the gene and the corresponding enzyme variants is unaltered by high temperatures and the phage particle are still infective and the genes selected can be amplified by E. coli after infection (cf. for example, Kristensen P, Winter G. Proteolytic selection for protein folding using filamentous bacteriophages. Fold Des. 1998;3(5):321-8) By way of example of the aforementioned embodiments, the present invention relates to a purified, thermostable DNA polymerase purified from Thermus aquaticus and recombinant means for producing the enzyme. Thermostable DNA polymerases are useful in many recombinant DNA techniques, especially nucleic acid amplification by the polymerase chain reaction (PCR) Directed protein-evolution strategies generally make use of a link between a protein and the encoding DNA. In phage-display technology, this link is provided by fusion of the protein with a coat-protein that is incorporated into the phage particle containing the DNA. Optimization of this link can be achieved by adjusting the signal sequence of the fusion. Linking of a gene to its corresponding polypeptide is a central step in directed protein evolution toward new functions. Filamentous bacteriophage particles have been extensively used to establish this linkage between a gene of interest and its protein expressed as a fusion product with a phage coat protein for incorporation into the phage particle. Libraries of proteins displayed on phage can be subjected to in vitro selection to isolate proteins with desired properties together with their genes. Creating a link between a gene and a single corresponding protein was achieved by making use of a phagemid for expression of the fusion protein and of a helper phage for assembly of the phage particles. This approach, yielding a monovalent display of protein, was found to be essential to avoid avidity effects or chelate effects, which introduce strong biases during in vitro selections for affinity. However, it also produces phage particles that do not display any protein of interest and which thereby represent a background in evolution experiments. To optimize the link between a gene and a single corresponding protein, several methods have been used. For example, the periplasmic factor Skp was found to improve the display of single-chain Fv antibodies on filamentous phage (Bothmann, H. and Plückthun, A. (1998) Selection for a periplasmic factor improving phage display and functional periplasmic expression. Nat. Biotech. 16, 376-380.). In a previous study, the present inventors showed that specific signal sequences for optimal display on phage of the Taq DNA polymerase I Stoffel fragment can be isolated from a library of more than 107 signal sequences derived from pelB (Jestin, J. L., Volioti, G. and Winter, G. (2001). Improving the display of proteins on filamentous phage. Res. Microbiol. 152, 187-191). Signal sequences, once translated, are recognized by the bacterial protein export machinery. The polypeptide is then exported in the bacterial periplasm before cleavage of the signal peptide by the signal peptidase, thereby releasing the mature protein. A short sequence, m (SG4CG4; SEQ ID NO: 39), at the C-terminus of the signal sequence, was initially introduced as a potential cross-linking site of substrates on phage that may be useful for selections by catalytic activity. This glycine-rich sequence may also be important for preventing structure formation at the peptidase cleavage site or for defining two independently folding units in the pre-protein. The glycine-rich sequence may then improve the signal sequence processing and finally lead to a greater ratio of protein fusions on phage. The present inventors, therefore, evaluated the effect of a selected signal sequence on the display of proteins on phage, as well as the effect of the m sequence at the C-terminus of the signal peptide. In an embodiment of the present invention is a method of identifying thermostable mutant polymerases derived from the Stoffel fragment of Taq comprising a) packaging a vector in which a polynucleotide encoding a phage coat protein is fused to a polynucleotide encoding a protein having at least 80% identity to SEQ ID NO: 26 into a phage b) expressing the fusion protein; c) isolation (selection) of phage particles; d) infecting E. coli and incubating the infected E. coli; e) detecting the fusion protein; f) assessing polymerase activity. In this method, evolutionarily advantageous mutants may be identified by repeating steps (b)-(f) 0 to 25 times, preferably 0-20 times, more preferably 1-15 times, a most preferably 2 to 10 times. The method comprising one cycle (repeated 0 times) is particularly adapted to high throughput screening, when steps are repeated from 3 to 7 times, the method is better adapted for classical emprirical screening. In a preferred embodiment, the phage coat protein has a sequence of SEQ ID NO: 39. By way of example, Applicants provide the following exemplary discussion of the phage-display method of the present invention and refer to Strobel et al, Molec. Biotech. 2003, vol. 24, pp. 1-9, which is incorporated herein by reference in its entirety: The amino acid signal sequences are: pelB: MKYLLPTAAAGLLLLAAQPAMA; (SEQ ID NO: 41) l7: MKTLLAMVLVGLLLLPPGPSMA; (SEQ ID NO: 42) l10: MRGLLAMLVAGLLLLPIAPAMA; (SEQ ID NO: 43) and l12: MRRLLVIAAGLLLLLAPPTMA. (SEQ ID NO: 44) The present inventors goal was to increase the display of proteins at the surface of filamentous phages. As model proteins, the present inventors chose the catalytic domains of adenylate cyclases from E. coli (ACE) and from B. pertussis (ACB). The present inventors also examined the display of two different enzymes, an adenylate cyclase and the Stoffel fragment of Taq DNA polymerase I, incorporated into phage particles as single polypeptide fusion products with minor coat protein p3. In this work, the present inventors evaluated the effects of two signal peptides (pelB and 17) and of the short peptide (m; SEQ ID NO: 39) at the N-terminus of the fusion of these enzymes with p3. One other construct, deriving from the selected signal peptide 112, is also mentioned here, and the data are summarized together with previously published data for the selected signal sequences 110 and 112 (2). The phage particles were produced by using a helper phage, KM13 (6), for assembly of the particles, and by using phagemids pHEN1 (5), pHEN117, and pHEN1112 (2) encoding the p3 fusion proteins. These phagemid vectors differ in their signal sequence: pelB is from Erwinia caratovora pectate lyase B (7), whereas signal sequences 17, 110, and 112, were selected from a library of more than 107 signal sequences for optimal display of the Stoffel fragment on filamentous phage (2). For all 17 phagemids encoding the different fusion proteins described in this work, the present inventors observed standard titers of infective particles, which were all in the range of 1.4×1010-7.8×1010 phages/mL of culture medium. Furthermore, enzymatic activities were detected for all phage-cyclase particles by thin layer chromatography and by HPLC (data not shown). The efficiency of protein display on phage was evaluated through two approaches. The first makes use of the engineered helper phage KM13 (6) to measure the fraction of infective phage particles that display a fusion product. The p3 fusion protein provided by the phagemid and the p3 protein provided by the helper phage compete for incorporation into the phage particles. The helper phage p3 is engineered so as to contain a protease cleavage site between domains 2 and 3 of p3. In phage particles that contain only helper p3 copies, no full p3 copy is available for bacterial infection after protease treatment: the phage particles are noninfective. If a phage particle has incorporated a p3 fusion protein, one copy of the three-p3 domains remains after protease cleavage, and is sufficient for infection of E. coli. The trypsin-resistant fraction of phage is therefore a measure of protein display on infective phages. With this method, the display of fusion proteins was found to vary over more than two orders of magnitude for each cyclase, depending on the signal sequence and on neighboring sequences. Among the phagemid vectors containing the selected signal sequence 17, three of the four fusion proteins that the present inventors studied (AC—p3 and AC—Stoffel—p3, where AC is the adenylate cyclase catalytic domain of E. coli or B. pertussis) were remarkably well incorporated into phage particles: more than one phage particle out of ten displayed an enzyme. No more than one particle in 300 displayed the E. coli cyclase fused to the Stoffel fragment and to protein 3, and better display of this protein could not be found among the constructs tested. The peptide m, SG4CG4, at the N-terminus of the mature fusion protein, was found to increase the display of B. pertussis cyclase-polymerase fusion on phage, by 100-fold for signal sequence 17 and by 10-fold for pelB. For this fusion, the worst display ratios are significantly improved with peptide m. Display of B. pertussis cyclase on phage was high in all cases, such that a marginal improvement due to the m peptide was found for signal sequence 17, and improvement within the limits of experimental error for pelB. Concerning the E. coli cyclase protein, peptide m decreases the latter's display by a factor of 30 to 40. For the E. coli cyclase-polymerase fusion, peptide m showed no significant effect with the signal sequence pelB and a small improvement with signal sequence 17. Significant effects of the signal sequence on phage display were detected for three of the four fusions in the present inventors' study: from 5- to about 20-fold improvements in display on phage were noted for substitution of pelB by signal sequence 17. In the case of the B. pertussis cyclase—p3 fusion protein, incorporation of the fusion protein into phage particles was high, whether the signal sequence was pelB, 17, or 112. Indeed, for the selected signal sequence 112, up to 40% of infective phage particles displayed an enzyme at the surface of filamentous phage. When two enzymes were simultaneously displayed on phage (either E. coli or B. pertussis adenylate cyclase and the Stoffel fragment polymerase), the present inventors noted that the incorporation of p3 fusion products was significantly reduced in most cases. Remarkably, about half of the infective phage particles displayed a B. pertussis adenylate cyclase—Stoffel fragment polymerase—p3 protein fusion when the selected signal sequence 17 and the short N-terminal peptide m were present in the construct. The second approach to estimating the level of fusion proteins incorporated into phage particles relies on the detection of p3 domain 3 by a monoclonal antibody (8) after SDS-PAGE and Western blotting of denatured phage particles. These results are in accordance with the data the present inventors obtained by measuring the trypsin-resistant fraction of infective phages. All fusion products expressed on phage and which correspond to a trypsin-resistant fraction of phage higher than 0.1 are indeed observed by Western blot analysis. The present inventors aim to direct the evolution of adenylate cyclases by in vitro selection using a chemistry involving filamentous phage. This should provide a tool for the engineering of adenylate cyclases as well as a strategy for the functional cloning of this class of enzymes. Recent in vitro selection methods for catalytic activity using phage display have been designed as affinity chromatography methods for the reaction product linked to the phageenzyme that catalyzed the reaction from substrate to product. These selection methods were established with enzymes such as nuclease (9), DNA polymerase (10), peptidase (11,12), peptide ligase (13), and beta-lactamase (14). They require an efficient display of enzyme on phage and a method to link the substrate/product to phage-enzymes. In the work reported here, the present inventors investigated the display of adenylate cyclases from B. pertussis and from E. coli on filamentous phage, and the display of two independent enzymes, an adenylate cyclase and the Taq DNA polymerase I Stoffel fragment. The Stoffel fragment (15) could be used as a tool to establish an in vitro selection for cyclase activity as follows: the polymerase domain may serve as an anchor of the substrate ATP on phage through double-stranded DNA used as a linker with a high affinity for the fusion protein. Another approach to cross-linking substrate and phage involves introduction of the thiol group of a cysteine residue within peptide m (SG4CG4), at the N-terminus of the mature fusion protein and at the C-terminus of the fusion protein's signal sequence (10). The signal sequences 17, 110, and 112, used in the present inventors' study had been selected from large libraries of pelB mutants for optimal display of the Stoffel fragment—p3 protein fused to the peptide m (2). It was therefore important to further investigate which sequence context was essential for selection of these signal sequences, either the short peptide m or the entire gene. Interestingly, the present inventors found that the presence or the absence of this short peptide, SG4CG4, can yield up to 100-fold increases in the display of a fusion protein on filamentous phage. This strong effect was observed for the B. pertussis cyclase—Stoffel—p3 fusion as well as for the E. coli cyclase—p3 fusion in the case of the signal sequence 17 (Table 2). Of further note is that the signal sequences 17 and 1 12, yield generally better levels of protein display on phage than does pelB (FIG. 3). This improved display of proteins might be ascribed to the different targeting modes of the signal sequences. These selected signal sequences that improve the display of proteins on phage should therefore be useful in other systems. Our study highlights the important effects of the signal sequence and of a short peptide at the C-terminus of the signal sequence on the display of proteins on phage. Apart from the previously stated conclusions that the selected signal sequence 17 often yields an improved display as compared with pelB, and that sequence m can have drastic effects on the level of protein display, the set of protein fusions described here is not sufficient to define any further rules about sequences and optimal display of proteins on phage. Indeed, incorporation of a fusion protein into a phage particle is the result of a complex sequence of events involving fusion gene transcription and translation, folding, and export of the fusion protein, as well as cleavage of the signal sequence. Two approaches, however, can be envisaged for efficient display of proteins on bacteriophage. First, directed signal peptide evolution experiments can be undertaken for any defined protein so as to isolate a signal sequence for optimal display on phage. This approach was described previously in the case of the Stoffel fragment of Taq DNA polymerase I (2). A more straightforward and quicker approach consists of the screening of several phagemid vectors that differ in their signal sequences and, more generally, in their regulatory sequences. In this report the present inventors have shown that for three of the four fusion proteins tested, excellent cyclase display levels can be obtained: more than one phage in ten displays an enzyme. Such display levels for large proteins should be useful for further approaches to directed protein evolution. With use of the phagemid strategy, almost every particle expresses a p3 copy provided by the phagemid if no gene fusion has been engineered or if the insert from the gene fusion has been deleted. On the contrary, about one phage particle in a thousand incorporates large fusion proteins such as cyclase—Stoffel fragment—p3 fusions. This indicates that for an equal mixture of two genes, thousand-fold differences in expression of the corresponding proteins on phage particles can be obtained. This bias may be of no importance if enrichment factors per selection round are much larger than 103, but it may otherwise significantly alter the outcome of evolution experiments. Similar protein expression levels on phage of different genes would be useful to minimize biases introduced by successive amplifications in evolution experiments. The use of sets of phagemid vectors that differ by their signal sequences and by neighboring sequences might be of interest for better representation of protein libraries on filamentous phage. Additionally, the display of two distinct enzymes on single phage particles might be useful to direct their coevolution, especially in the case of two enzymes involved in the same metabolic pathway with an unstable reaction intermediate. By insertion or by deletion of the short peptide sequence SG4CG4 (m; SEQ ID NO: 39) at the C-terminus of the signal sequence, the present inventors have shown that two enzymes can be very efficiently expressed as single polypeptides on the surface of filamentous bacteriophage by using the phagemid strategy. The model proteins described in this study are the catalytic domains of adenylate cyclases of B. pertussis or of E. coli, fused or not fused to the Stoffel-fragment DNA polymerase. On average, the present inventors found the best display levels for the selected signal sequence 17, which had been previously selected from a large library for optimal display on phage of the Stoffel fragment, and not for the commonly used signal sequence pelB. Yet the present inventors observed striking differences in display levels of these enzymes on the surfaces of phage particles, depending on the short N-terminal peptide m. The findings reported here should be useful for the display of large and of cytoplasmic proteins on filamentous phage particles, and more generally for protein engineering using phage display. The term “thermostable” enzyme refers to an enzyme that is stable over a temperature range of approximately 55° C. to 105° C. In particular, thermostable enzymes in accordance with the present invention are heat resistant and catalyze the template directed DNA synthesis. Preferably, the activity of the thermostable enzymes of the present is at least 50% of activity, preferably at least 75%, more preferably at least 85%, of the wild-type enzyme activity over the same temperature range. In a particularly preferred embodiment, the thermostable enzyme of the present invention exhibits at least 50% of activity, preferably at least 75%, more preferably at least 85%, of the wild-type enzyme activity when said wild-type enzyme activity is measured under optimal conditions. Moreover, it is preferable that the “thermostable” enzyme does not become irreversibly denatured when subjected to the elevated temperatures and incubation time for denaturation of double-stranded nucleic acids, as well as the repetitive cycling between denaturation, annealing, and extension inherent to PCR-based techniques. As used herein, the term “reduced” or “inhibited” means decreasing the activity of one or more enzymes either directly or indirectly. The definition of these terms also includes the reduction of the in vitro activity, either directly or indirectly, of one or more enzymes. The term “enhanced” as used herein means increasing the activity or concentration one or more polypeptides, which are encoded by the corresponding DNA. Enhancement can be achieved with the aid of various manipulations of the bacterial cell, including mutation of the protein, replacement of the expression regulatory sequence, etc. In order to achieve enhancement, particularly over-expression, the number of copies of the corresponding gene can be increased, a strong promoter can be “operably linked,” or the promoter- and regulation region or the ribosome binding site which is situated upstream of the structural gene can be mutated. In this regard, the term “operably linked” refers to the positioning of the coding sequence such that a promoter, regulator, and/or control sequence will function to direct the expression of the protein encoded by the coding sequence located downstream therefrom. Expression cassettes that are incorporated upstream of the structural gene act in the same manner. In addition, it is possible to increase expression by employing inducible promoters. A gene can also be used which encodes a corresponding enzyme with a high activity. Expression can also be improved by measures for extending the life of the mRNA. Furthermore, preventing the degradation of the enzyme increases activity as a whole. Moreover, these measures can optionally be combined in any desired manner. These and other methods for altering gene activity in a plant are known as described, for example, in Methods in Plant Molecular Biology, Maliga et al, Eds., Cold Spring Harbor Laboratory Press, New York (1995). The definition of these terms also includes the enhancement of the in vitro activity, either directly or indirectly, of one or more enzymes. A gene (polynucleotide) can also be used which encodes a corresponding or variant polymerase having at least 80% identity to SEQ ID NO: 26. These gene(polynucleotides) can have various mutations. For example, a mutation of one or more amino acids in amino acids 738 to 767 of SEQ ID NO:26. Further examples of mutations include mutations at positions M470, F472, M484, and W550 A331, and S335. In a preferred embodiment, these mutations are A331T, S335N, M470K, M470R, F472Y, M484V, M484T, and W550R. In a particularly preferred embodiment, the polynucleotides of the present invention encode polypeptides having one or more of the aforementioned mutations and share at least 85% identity, at least 90% identity, at least 95% identity, or at least 97.5% identity to the polypeptide of SEQ ID NO: 26. Moreover, polynucleotides of the present invention encode polypeptides that have DNA polymerase activity and/or 5′-3′ exonuclease activity. More particularly, the polynucleotides of the present invention encode polypeptides that are capable of catalyzing the reverse transcription of mRNA. In the present invention, the polynucleotide may encode a polypeptide contain at least one mutation at a position selected from the group consisting of A331, L332, D333, Y334, and S335. The polynucleotide may encode a polypeptide of the present invention which has amino acid sequence selected from the group consisting of SEQ ID NO: 20, SEQ ID NO: 22, SEQ ID NO: 24, SEQ ID NO: 28, SEQ ID NO: 30, SEQ ID NO: 32, SEQ ID NO: 34, SEQ ID NO: 36, and SEQ ID NO: 38. Within the context of the present application, the preferred polynucleotides possess a polynucleotide sequence selected from the group consisting of SEQ ID NO: 19, SEQ ID NO: 21, SEQ ID NO: 23, SEQ ID NO: 27, SEQ ID NO: 29, SEQ ID NO: 31, SEQ ID NO: 33, SEQ ID NO: 35, and SEQ ID NO: 37. Within the scope of the present invention are also polynucleotides that are homologous to the aforementioned sequences. In the context of the present application, a polynucleotide sequence is “homologous” with the sequence according to the invention if at least 80%, preferably at least 90%, more preferably 95%, and most preferably 97.5% of its base composition and base sequence corresponds to the sequence according to the invention. It is to be understood that, as evinced by the Examples of the present invention and the phage-display method highlighted herein, screening of theoretical mutations within the scope of the present invention would require nothing more than a technician's level of skill in the art. More specifically, as is routine in the art, with the identification of a candidate sequence the artisan would assay and screen one or all possible permutations of the said sequence to identify mutants possessing the same or better DNA polymerase activity, reverse transcriptase activity, and/or 5′-3′ exonuclease activity. The expression “homologous amino acids” denotes those that have corresponding properties, particularly with regard to their charge, hydrophobic character, steric properties, etc. Homology, sequence similarity or sequence identity of nucleotide or amino acid sequences may be determined conventionally by using known software or computer programs such as the BestFit or Gap pairwise comparison programs (GCG Wisconsin Package, Genetics Computer Group, 575 Science Drive, Madison, Wisc. 53711). BestFit uses the local homology algorithm of Smith and Waterman, Advances in Applied Mathematics 2: 482-489 (1981), to find the best segment of identity or similarity between two sequences. Gap performs global alignments: all of one sequence with all of another similar sequence using the method of Needleman and Wunsch, J. Mol. Biol. 48:443-453 (1970). When using a sequence alignment program such as BestFit, to determine the degree of sequence homology, similarity or identity, the default setting may be used, or an appropriate scoring matrix may be selected to optimize identity, similarity or homology scores. Similarly, when using a program such as BestFit to determine sequence identity, similarity or homology between two different amino acid sequences, the default settings may be used, or an appropriate scoring matrix, such as blosum45 or blosum80, may be selected to optimize identity, similarity or homology scores. The terms “isolated” or “purified” means separated from its natural environment. The term “polynucleotide” refers in general to polyribonucleotides and polydeoxyribonucleotides, and can denote an unmodified RNA or DNA or a modified RNA or DNA. The term “polypeptides” is to be understood to mean peptides or proteins that contain two or more amino acids that are bound via peptide bonds. A “polypeptide” as used herein is understood to mean a sequence of several amino acid residues linked by peptide bonds. Such amino acids are known in the art and encompass the unmodified and modified amino acids. In addition, one or more modifications known in the art such as glycosylation, phosphorylation, etc may modify the polypeptide. The term “homologous” as used herein is understood to mean two or more proteins from the same species or from a different species. Within the meaning of this term, said two or more polypeptides share at least 80% identity to the polypeptide of SEQ ID NO: 26 and can have the mutations discussed herein. In a particularly preferred embodiment, the polypeptides of the present invention have one or more of the aforementioned mutations and share at least 85% identity, at least 90% identity, at least 95% identity, or at least 97.5% identity to the polypeptide of SEQ ID NO: 26. Moreover, the polypeptides of the present invention have DNA polymerase activity and/or 5′-3′ exonuclease activity. More particularly, the polypeptides of the present invention are capable of catalyzing the reverse transcription of mRNA. In the present invention, the polypeptide may contain one or more mutations, such as A331, L332, D333, Y334, and S335. The isolated polypeptide of the present invention has an amino acid sequence selected from the group consisting of SEQ ID NO: 20, SEQ ID NO: 22, SEQ ID NO: 24, SEQ ID NO: 28, SEQ ID NO: 30, SEQ ID NO: 32, SEQ ID NO: 34, SEQ ID NO: 36, and SEQ ID NO: 38. In an embodiment of the present invention are mutations concerning alanine in position 331 (A331), and serine in position 335 (S335) that may have particular importance derived from the fact that they are surrounding the aspartic acid D in position 333 which is responsible for the chelation of Mn2+ or Mg2+. Thus, in one embodiment of the present invention, mutations of one or more amino acids 10 amino acids upstream and/or 10 amino acids downstream of this site are provided. The expression “homologous amino acids” denotes those that have corresponding properties, particularly with regard to their charge, hydrophobic character, steric properties, etc. Moreover, one skilled in the art is also aware of conservative amino acid replacements such as the replacement of glycine by alanine or of aspartic acid by glutamic acid in proteins as “sense mutations” which do not result in any fundamental change in the activity of the protein, i.e. which are functionally neutral. It is also known that changes at the N- and/or C-terminus of a protein do not substantially impair the function thereof, and may even stabilize said function. As such, these conservative amino acid replacements are also envisaged as being within the scope of the present invention. The present invention also relates to DNA sequences that hybridize with the DNA sequence that encodes a corresponding or variant polymerase having at least 80% homology to SEQ ID NO: 26, the polypeptides having the mutations described herein. The present invention also relates to DNA sequences that are produced by polymerase chain reaction (PCR) using oligonucleotide primers that result from the DNA sequence that encodes a corresponding or variant polymerase having at least 80% homology to SEQ ID NO: 26, wherein the polypeptide has at least one mutation as described herein, or fragments thereof. Oligonucleotides of this type typically have a length of at least 15 nucleotides. The terms “stringent conditions” or “stringent hybridization conditions” includes reference to conditions under which a polynucleotide will hybridize to its target sequence, to a detectably greater degree than other sequences (e.g., at least 2-fold over background). As used herein, stringent hybridization conditions are those conditions which allow hybridization between polynucleotides that are 80%, 85%, 90%, 95%, or 97.5% homologous as determined using conventional homology programs, an example of which is UWGCG sequence analysis program available from the University of Wisconsin. (Devereaux et al., Nucl. Acids Res. 12: 387-397 (1984)). Stringent conditions are sequence-dependent and will be different in different circumstances. By controlling the stringency of the hybridization and/or washing conditions, target sequences can be identified which are 100% complementary to the probe (homologous probing). Alternatively, stringency conditions can be adjusted to allow some mismatching in sequences so that lower degrees of similarity are detected (heterologous probing). Typically, stringent conditions will be those in which the salt concentration is less than about 1.5 M Na ion, typically about 0.01 to 1.0 M Na ion concentration (or other salts) at pH 7.0 to 8.3 and the temperature is at least about 30° C. for short probes (e.g., 10 to 50 nucleotides) and at least about 60° C. for long probes (e.g., greater than 50 nucleotides). Stringent conditions may also be achieved with the addition of destabilizing agents such as formamide. Exemplary low stringency conditions include hybridization with a buffer solution of 30 to 35% formamide, 1 M NaCl, 1% SDS (sodium dodecyl sulfate) at 37° C., and a wash in 1× to 2×SSC (20×SSC=3.0 M NaCl/0.3 M trisodium citrate) at 50 to 55° C. Exemplary moderate stringency conditions include hybridization in 40 to 45% formamide, 1 M NaCl, 1% SDS at 37° C., and a wash in 0.5× to 1×SSC at 55 to 60 ° C. Exemplary high stringency conditions include hybridization in 50% formamide, 1 M NaCl, 1% SDS at 37° C., and a wash in 0.1×SSC at 60 to 65° C. Specificity is typically the function of post-hybridization washes, the critical factors being the ionic strength and temperature of the final wash solution. For DNA—DNA hybrids, the Tm can be approximated from the equation of Meinkoth and Wahl, Anal. Biochem., 138:267-284 (1984): Tm=81.5° C. +16.6 (log M)+0.41 (% GC)−0.61 (% form)−500/L; where M is the molarity of monovalent cations, % GC is the percentage of guanosine and cytosine nucleotides in the DNA, % form is the percentage of formamide in the hybridization solution, and L is the length of the hybrid in base pairs. The Tm is the temperature (under defined ionic strength and pH) at which 50% of a complementary target sequence hybridizes to a perfectly matched probe. Tm is reduced by about 1° C. for each 1% of mismatching; thus, Tm, hybridization and/or wash conditions can be adjusted to hybridize to sequences of the desired identity. For example, if sequences with approximately 90% identity are sought, the Tm can be decreased 10° C. Generally, stringent conditions are selected to be about 5° C. lower than the thermal melting point (Tm) for the specific sequence and its complement at a defined ionic strength and pH. However, severely stringent conditions can utilize a hybridization and/or wash at 1, 2, 3, or 4° C. lower than the thermal melting point (Tm); moderately stringent conditions can utilize a hybridization and/or wash at 6, 7, 8, 9, or 100° C. lower than the thermal melting point (Tm); low stringency conditions can utilize a hybridization and/or wash at 11, 12, 13, 14, 15, or 20° C. lower than the thermal melting point (Tm). Using the equation, hybridization and wash compositions, and desired Tm, those of ordinary skill will understand that variations in the stringency of hybridization and/or wash solutions are inherently described. If the desired degree of mismatching results in a Tm of less than 45° C. (aqueous solution) or 32° C. (formamide solution) it is preferred to increase the SSC concentration so that a higher temperature can be used. An extensive guide to the hybridization of nucleic acids is found in Current Protocols in Molecular Biology, Chapter 2, Ausubel, et al., Eds., Greene Publishing and Wiley-Interscience, New York (2000). Thus, with the foregoing information, the skilled artisan can identify and isolated polynucleotides, which are substantially similar to the present polynucleotides. In isolating such a polynucleotide, the polynucleotide can be used as the present polynucleotide in, for example, to express a polypeptide having DNA polymerase activity and 5′-3′ exonuclease activity. One embodiment of the present invention is methods of screening for polynucleotides, which have substantial homology to the polynucleotides of the present invention, preferably those polynucleotides encoding a polypeptide having DNA polymerase activity and/or 5′-3′ exonuclease activity. The polynucleotide sequences of the present invention can be carried on one or more suitable plasmid vectors, as known in the art for bacteria or the like. Host cells useful in the present invention include any cell having the capacity to be infected or transfected by phages or vectors comprising the polynucleotide sequences encoding the enzymes described herein and, preferably also express the thermostable enzymes as described herein. Suitable host cells for expression include prokaryotes, yeast, archae, and other eukaryotic cells. Appropriate cloning and expression vectors for use with bacterial, fungal, yeast, and mammalian cellular hosts are well known in the art, e.g., Pouwels et al. Cloning Vectors: A Laboratory Manual, Elsevier, N.Y. (1985). The vector may be a plasmid vector, a single or double-stranded phage vector, or a single or double-stranded RNA or DNA viral vector. Such vectors may be introduced into cells as polynucleotides, preferably DNA, by well known techniques for introducing DNA and RNA into cells. The vectors, in the case of phage and viral vectors also may be and preferably are introduced into cells as packaged or encapsulated virus by well known techniques for infection and transduction. Viral vectors may be replication competent or replication defective. In the latter case viral propagation generally will occur only in complementing host cells. Cell-free translation systems could also be employed to produce the enzymes using RNAs derived from the present DNA constructs. Prokaryotes useful as host cells in the present invention include gram negative or gram positive organisms such as E. coli or Bacilli. In a prokaryotic host cell, a polypeptide may include a N-terminal methionine residue to facilitate expression of the recombinant polypeptide in the prokaryotic host cell. The N-terminal Met may be cleaved from the expressed recombinant polypeptide. Promoter sequences commonly used for recombinant prokaryotic host cell expression vectors include β-lactamase and the lactose promoter system. Expression vectors for use in prokaryotic host cells generally comprise one or more phenotypic selectable marker genes. A phenotypic selectable marker gene is, for example, a gene encoding a protein that confers antibiotic resistance or that supplies an autotrophic requirement. Examples of useful expression vectors for prokaryotic host cells include those derived from commercially available plasmids such as the cloning vector pBR322 (ATCC 37017). pBR322 contains genes for ampicillin and tetracycline resistance and thus provides simple means for identifying transformed cells. To construct an expression vector using pBR322, an appropriate promoter and a DNA sequence are inserted into the pBR322 vector. Other commercially available vectors include, for example, pKK223-3 (Pharmacia Fine Chemicals, Uppsala, Sweden) and pGEM1 (Promega Biotec, Madison, Wisc., USA). Promoter sequences commonly used for recombinant prokaryotic host cell expression vectors include β-lactamase (penicillinase), lactose promoter system (Chang et al., Nature275:615, (1978); and Goeddel et al., Nature 281:544, (1979)), tryptophan (trp) promoter system (Goeddel et al., Nucl. Acids Res. 8:4057, (1980)), and tac promoter (Maniatis, Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory, p. 412 (1982)). Yeasts useful as host cells in the present invention include those from the genus Saccharomyces, Pichia, K. Actinomycetes and Kluyveromyces. Yeast vectors will often contain an origin of replication sequence from a 2μ yeast plasmid, an autonomously replicating sequence (ARS), a promoter region, sequences for polyadenylation, sequences for transcription termination, and a selectable marker gene. Suitable promoter sequences for yeast vectors include, among others, promoters for metallothionein, 3-phosphoglycerate kinase (Hitzeman et al., J. Biol. Chem. 255:2073, (1980)) or other glycolytic enzymes (Holland et al., Biochem. 17:4900, (1978)) such as enolase, glyceraldehyde-3-phosphate dehydrogenase, hexokinase, pyruvatee decarboxylase, phosphofructokinase, glucose-6-phosphate isomerase, 3-phosphoglycerate mutase, pyruvate kinase, triosephosphate isomerase, phosphoglucose isomerase, and glucokinase. Other suitable vectors and promoters for use in yeast expression are further described in Fleer et al., Gene, 107:285-195 (1991). Other suitable promoters and vectors for yeast and yeast transformation protocols are well known in the art. Yeast transformation protocols are known to those of skill in the art. One such protocol is described by Hinnen et al., Proceedings of the National Academy of Sciences USA, 75:1929 (1978). The Hinnen protocol selects for Trp.sup.+ transformants in a selective medium, wherein the selective medium consists of 0.67% yeast nitrogen base, 0.5% casamino acids, 2% glucose, 10 μ/ml adenine, and 20 μ/ml uracil. Mammalian or insect host cell culture systems well known in the art could also be employed to express recombinant polypeptides, e.g., Baculovirus systems for production of heterologous proteins in insect cells (Luckow and Summers, Bio/Technology 6:47 (1988)) or Chinese hamster ovary (CHO) cells for mammalian expression may be used. Transcriptional and translational control sequences for mammalian host cell expression vectors may be excised from viral genomes. Commonly used promoter sequences and enhancer sequences are derived from Polyoma virus, Adenovirus 2, Simian Virus 40 (SV40), and human cytomegalovirus. DNA sequences derived from the SV40 viral genome may be used to provide other genetic elements for expression of a structural gene sequence in a mammalian host cell, e.g., SV40 origin, early and late promoter, enhancer, splice, and polyadenylation sites. Viral early and late promoters are particularly useful because both are easily obtained from a viral genome as a fragment which may also contain a viral origin of replication. Exemplary expression vectors for use in mammalian host cells are well known in the art. The enzymes of the present invention may, when beneficial, be expressed as a fusion protein that has the enzyme attached to a fusion segment. The fusion segment often aids in protein purification, e.g., by permitting the fusion protein to be isolated and purified by affinity chromatography. Fusion proteins can be produced by culturing a recombinant cell transformed with a fusion nucleic acid sequence that encodes a protein including the fusion segment attached to either the carboxyl and/or amino terminal end of the enzyme. In one embodiment, it may be advantageous for propagating the polynucleotide to carry it in a bacterial or fungal strain with the appropriate vector suitable for the cell type. Common methods of propagating polynucleotides and producing proteins in these cell types are known in the art and are described, for example, in Maniatis et al., Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press, New York (1982) and Sambrook et al., Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press, New York (1989). In one embodiment of the present invention are monoclonal phages: 1. SJL q deposited as CNCM I-3168 in the Collection Nationale de Cultures de Microorganismes (CNCM) on Feb. 27, 2004. 2. SJL d deposited as CNCM I-3169 in the Collection Nationale de Cultures de Microorganismes (CNCM) on Feb. 27, 2004. 3. SJL I deposited as CNCM I-3170 in the Collection Nationale de Cultures de Microorganismes (CNCM) on Feb. 27, 2004. 4. SJL s deposited as CNCM I-3171 in the Collection Nationale de Cultures de Microorganismes (CNCM) on Feb. 27, 2004. 5. SJL b deposited as CNCM I-3172 in the Collection Nationale de Cultures de Microorganismes (CNCM) on Feb. 27, 2004. 6. SJL n deposited as CNCM I-3173 in the Collection Nationale de Cultures de Microorganismes (CNCM) on Feb. 27, 2004. 7. SJL g deposited as CNCM I-3174 in the Collection Nationale de Cultures de Microorganismes (CNCM) on Feb. 27, 2004. 8. SJL m deposited as CNCM I-3175 in the Collection Nationale de Cultures de Microorganismes (CNCM) on Feb. 27, 2004. 9. SJL a deposited as CNCM I-3176 in the Collection Nationale de Cultures de Microorganismes (CNCM) on Feb. 27, 2004. In an embodiment of the present invention is a kit for amplifying DNA containing: an isolated thermostable polypeptide, wherein said polypeptide has at least 80% homology to SEQ ID NO: 26, wherein said polypeptide has at least one mutation at a position selected from the group consisting of M470, F472, M484, and W550, more preferably selected from the group consisting of M470K, M470R, F472Y, M484V, M484T, and W550R, and wherein said polypeptide has DNA polymerase activity and 5′-3′ exonuclease activity; a concentrated buffer solution, wherein when said concentrated buffer is admixed with the isolated polypeptide the overall buffer concentration is 1×; one or more divalent metal ions; and deoxyribonucleotides. In this embodiment, the preferred divalent metal ion is Mg2+ or Mn2+. In this connection, the concentration of the divalent metal ion ranges from 0.1 to 5 mM, preferably from 1 to 3 mM, more preferably from 2 to 2.5 mM. However, if the reaction is performed in a phosphate buffer, a buffer containing EDTA, or a buffer containing any other magnesium chelator, the concentration of magnesium may be increased to up to 100 mM. For the kit of the present invention the isolated thermostable polypeptide may be in a form selected from the group consisting of a lyophilized form, a solution form in a suitable buffer or carrier, and a frozen form in a suitable buffer or carrier. The kit of the present invention may also include a 5′ to 3′ exonuclease and/or a 3′ to 5′ exonuclease. A preferred 5′ to 3′ exonuclease has a sequence as in SEQ ID NO: 50 (the DNA is in SEQ ID NO:60) and the 3′ to 5′ exonuclease as in SEQ ID NO: 51 (the DNA is in SEQ ID NO:61). With respect to the suitable buffer or carrier, the following components may be used: Tris-HCl, KCl, Triton-X100, dimethylsulfoxide, tetramethyl ammonium chloride, etc. In the present invention, the concentrated buffer solution corresponds to a stock solution that has a concentration ranging from 1.5× to 10×, where the concentration is measured in relation to the final reaction concentration (1×). To this end, the buffer solution (1×) contains the following components: 10 mM Tris-HCl, pH at 25° C. of 9, 50 mM KCl, 0.1% Triton-X100. For the kit according to the present invention, the stock concentration of the deoxyribonucleotides ranges from 50 μM to 200 mM, preferably from 75 μM to 150 mM, more preferably 100 μM to 100 mM, for each dNTP. Moreover, the concentration of each dNTP in the PCR reaction according to the present invention should range from 10 μM to 500 μM, preferably from 25 μM to 400 μM, more preferably 50 μM to 300 μM. As used in the present invention, the term “deoxyribonucleotides” includes: dATP, dCTP, dGTP, and dTTP. It is to be understood that within the scope of the present invention, the kit may include in place of or in addition to the aforementioned components, RNA precursors, minor (“rare”) bases, and/or labelled bases. In another embodiment of the present invention is a method of amplifying DNA from a culture and/or purified stock solution of DNA and/or mRNA by utilizing a thermostable polypeptide according to the present invention. To this end, protocols for conducting PCR and RT-PCR would be readily appreciated by the skilled artisan. However, for sake of completeness, the artisan is directed to the following exemplary references for protocols for conducting PCR and RT-PCR (See, for example, Rougeon, F, et al. (1975) Nucl. Acids Res., 2, 2365-2378; Rougeon, F, et al. (1976) Proc. Natl. Acad. Sci. USA, 73, 3418-3422; Grabko, V. I., et al. (1996) FEBS Letters, 387, 189-192; and Perler, F., et al. (1996) Adv. Prot. Chem., 48, 377-435) With reference to reverse transcribing an RNA, a preferred method includes: a) providing a reverse transcription reaction mixture comprising said RNA, a primer, a divalent cation, and an isolated thermostable polypeptide comprising an amino acid sequence having at least 80% homology to SEQ ID NO: 26, wherein said polypeptide has at least one mutation at a position selected from the group consisting of M470, F472, M484, and W550, more preferably selected from the group consisting of M470K, M470R, F472Y, M484V, M484T, and W550R, and wherein said polypeptide has DNA polymerase activity and 5′-3′ exonuclease activity in a suitable buffer; and b) treating said reaction mixture at a temperature and under conditions suitable for said isolated polypeptide to initiate synthesis of an extension product of said primer to provide a cDNA molecule complementary to said RNA. It is to be understood that the skilled artisan would appreciate that the thermal cycling should be optimized to account for variations in the enzyme selected, the template to be reverse transcribed, the primers to be used to facilitate amplification (i.e., with respect to the melting and annealing temperatures), and the relative concentrations to be used for each of the reaction components. Such optimization is well within the purview of the skilled artisan; however, exemplary protocols may include the following: TABLE 2 PCR protocols # of repeated a b c d e Cycles PCR 1 94° C., 3′ 94° C., 1′ 66° C., 1′ 72° C., 2′ 72° C., 15′ b-d = 30 PCR 2 94° C., 3′ 94° C., 1′ 62° C., 1′ 72° C., 2′ 72° C., 15′ b-d = 30 PCR 3 94° C., 3′ 94° C., 30″ 59° C., 30″ 72° C., 1′ 72° C., 15′ b-d = 30 PCR 4 94° C., 3′ 94° C., 30″ 68° C., 1.5′ 68° C., 6′ b-c = 35 PCR 5 94° C., 1′ 94° C., 30″ 70° C., 30″ 72° C., 1′ 72° C., 15′ b-d = 25 PCR 6 94° C., 3′ 94° C., 30″ 59° C., 30″ 72° C., 1′ 72° C., 15′ b-d = 35 PCR 7 94° C., 3′ 94° C., 1′ 58° C., 1′ 72° C., 2′ 72° C., 15′ b-d = 35 Moreover, it is to be understood that contemplated in the present invention is that with the polypeptide of the present invention the skilled artisan would appreciate that the buffer components and buffer concentrations should also be optimized. To this end, in a preferred embodiment, the kit of the present invention may be utilized. As used above, the phrases “selected from the group consisting of,” “chosen from,” and the like include mixtures of the specified materials. In one embodiment of a method of obtaining a thermostable variant enzyme is provided. This method comprises the following: a) screening enzymes expressed at the surface of phage particles and identifying at least a thermostable variant conserving its active; catalytic domain at regulated temperature according to the method of identifying thermostable mutant polypeptides having a catalytic activity as described herein, b) isolating and sequencing a DNA encoding said identified thermostable variant; c) preparing a vector comprising the DNA of step (b); d) transfecting or infecting cells with the vector obtained at step c); e) expressing the thermostable variant enzyme from the cells and optionally, f) recovering, isolating and purifying said thermostable variant enzyme expressed at step (e). Where a numerical limit or range is stated herein, the endpoints are included. Also, all values and subranges within a numerical limit or range are specifically included as if explicitly written out. Having generally described this invention, a further understanding can be obtained by reference to certain specific examples, which are provided herein for purposes of illustration only, and are not intended to be limiting unless otherwise specified. EXAMPLES Materials and methods Buffers Buffer A (1×): 50 mM Tris-HCl at pH 8.3 at 25° C., 50 mM KCl, 10 mM MgCl2, 0.5 mM spermidine, 10 mM dithiothreitol Buffer B (1×): 20 mM Tris-HCl at pH 8.8 at 25° C., 10 mM KCl, 10 mM (NH4)2SO4, 2 mM MgSO4, 0.1% Triton X-100, 0.1 g/l BSA Buffer C (1×): 10 mM Tris-HCl at pH 9.0 at 25° C., 50 mM KCl, 1.5 mM MgCl2, 0.1% Triton X-100 Synthesis of Substrates for Selection Deoxyoligonucleotides were prepared by solid phase synthesis on a DNA synthesizer (Expedite™, Millipore). The 5′-maleimidyl derivatized primer TAA CAC GAC AAA GCG CAA GAT GTG GCG T (SEQ ID NO: 13) was synthesized as described previously (Jestin J. L., Kristensen P., Winter G., A method for the selection of catalysis using phage display and proximity coupling. Angew. Chem. Int. Ed. 1999, 38, 8, 1124-1127. ) purified on a C18 reverse phase HPLC column, and characterized by electrospray mass spectroscopy 8998.4/8999.9 (measured/calculated). 5-[-N—[N—(N-biotinyl-ε-aminocaproyl)-γ-aminobutyryl]-3-aminoallyl]-2′deoxy-uridine-5′-triphosphate (biotin-dUTP) was purchased from Sigma and the other deoxynucleotide triphosphates dATP, dCTP and dGTP were obtained from Roche-Boehringer. Library Construction Three phagemids libraries were mixed for phage preparation. The first two libraries (I: FseI/NotI and II: PstI/NheI) derive from mutagenic PCR amplification of the wild-type Taq gene in the presence of manganese [I: reference(Fromant, Blanquet, Plateau, Anal. Biochem., 224, 347-353, 1995) with MnCl2: 0.5 mM; II: reference (Cadwell, Joyce, PCR methods and amplifications, Mutagenic PCR, 3, S136-S140) with four distinct MnCl2 concentrations (0.5, 0.35, 0.25 and 0.125 mM)] using following primers (I) SEQ ID NO: 1 and SEQ ID NO: 2, PCR 1, or (II) SEQ ID NO: 3 and SEQ ID NO: 4, PCR 2 (for primers: see Table 1, and for cycle settings: see Table 2). The third phagemids library (III) was constructed by oligonucleotide assembly using the wild-type Taq gene. First, four PCR fragments were prepared using Taq polymerase (PCR 3, see Table2), the wild-type Stoffel fragment gene as template and the following primer pairs (5-6), (7-8), (9-10) and (11-2) in buffer C 1X (for primers: see Table 1). After purification with the QIAquick PCR Purification kit (QIAGEN), the four PCR fragments were assembled in a second PCR round using the kit GC-Advantage obtained from Clontech under PCR 4 (see Table 2), using buffer D 1×. The crude PCR product was then amplified by PCR using PCR 5 protocol, the GC-Advantage kit, and the primers 1 and 2 in buffer D 1×. Subsequently, the product was purified using the QIAquick Gel extraction gel (QIAGEN). Buffer D 1× 40 mM Tricine-KOH (pH 9,2) 15 mM KOAc 3.5 mM Mg(OAc)2 5% DMSO 3.75 μg/ml BSA 0.005% Noninet P-40 0.005% Tween-20 After subcloning into pHEN1 vectors using restriction sites FseI/NotI or PstI/NheI, 1.1×107 distinct clones were obtained by electroporation in E. coli strain TG1. TABLE 1 Oligonuleotides and primers SEQ ID NO: Oligonucleotide sequences 1 TAACAATAGGCCGGCCACCCCTTC 2 GAGTTTTTGTTCTGCGGC 3 TTTAATCATCTGCAGTACCGGGAGCTC 4 TTCATTCTTGCTAGCTCCTGGGAGAGGC 5 CCG GCC ACC CCT TC(C AR/A VY)C TCA AC(C AR/A VY)CGG GAC CAG CTG GAA AG 6 GGA TGA GGT CCG GCA A(YT G/RB T) (YT G/RB T)AA T(YT G/RB T)GG TGC T CT TCA GCT T(YT G/RB T)GA GCT CCC GGT ACT GCA GG 7 CAA CCA GAC GGC CAC G(CA R/AV Y)AC GGG CAG GCT A(CA R/AV Y)AG CTC C(CA R/AV Y)CC CAA CCT CCA GAA CAT CC 8 CCG CCT CCC GCA C(YT G/RB T)CT TCA C(YT G/RB T)GG CCT CTA GGT CTG GCA C 9 CCT GCA GTA CCG GGA GCT C(CA R/AV Y)AA GCT GAA GAG CAC C (CA R/AV Y)AT T(CA R/AV Y)(CA R/AV Y)TT GCC GGA CCT CAT CC 10 GGA TGT TCT GGA GGT TGG G(YTG/RBT)GG AGC T(YTG/RBT)TA GCC TGC CCG T(YTG/RBT)CG TGG CCG TCT GGT TG 11 GTG CCA GAC CTA GAG GCC (CAR/AVY) GTG AAG (CAR/AVY) GTG CGG G AG GCG G 12 AAA UAC AAC AAU AAA ACG CCA CAU CUU GCG 13 TAA CAC GAC AAA GCG CAA GAT GTG GCG T 14 AAA TAC AAC AAT AAA ACG CCA CAT CTT GCG 15 TTCATTCTTGCTAGCTCCTGGGAGAGGC 16 GAG AAG ATC CTG CAG TAC CGG GAG C 17 GACCAAC ATCAAGACTGCC 18 TTGGCCAGGAACTTGTCC TABLE 2 PCR cycles # of repeated a b c d e Cycles PCR 1 94° C., 3′ 94° C., 1′ 66° C., 1′ 72° C., 2′ 72° C., 15′ b-d = 30 PCR 2 94° C., 3′ 94° C., 1′ 62° C., 1′ 72° C., 2′ 72° C., 15′ b-d = 30 PCR 3 94° C., 3′ 94° C., 30″ 59° C., 30″ 72° C., 1′ 72° C., 15′ b-d = 30 PCR 4 94° C., 3′ 94° C., 30″ 68° C., 1.5′ 68° C., 6′ b-c = 35 PCR 5 94° C., 1′ 94° C., 30″ 70° C., 30″ 72° C., 1′ 72° C., 15′ b-d = 25 PCR 6 94° C., 3′ 94° C., 30″ 59° C., 30″ 72° C., 1′ 72° C., 15′ b-d = 35 PCR 7 94° C., 3′ 94° C., 1′ 58° C., 1′ 72° C., 2′ 72° C., 15′ b-d = 35 Phage Preparation and Selection For phage preparation, E. coli TG1 transformed by the phagemid library and grown to an optical density of 0.3 at 600 nm were infected by a twenty-fold excess of helper phage. Phage particles were produced at 30° C. for 19 hours in a 2×TY medium containing 100 mg/l ampicillin, 25 mg/l kanamycin. After removal of bacteria by two centrifugation (4000 rpm, 4° C.), phage particles in the supernatant were purified by two precipitations in 4% polyethyleneglycol in 0.5 M NaCl, resuspended in 1 ml of PBS (pH 7.4), and dialyzed four times against PBS over a period of 24 hours. The pH of the final solution was raised to pH 8. The protocol for selection was as described previously (Jestin J. L., Kristensen P., Winter G. A method for the selection of catalysis using phage display and proximity coupling. Angew. Chem. Int. Ed. 1999, 38, 8, 1124-1127; Vichier-Guerre S., Jestin J. L. Iterative cycles of in vitro protein selection for DNA polymerase activity, Biocat. & Biotransf. 2003, 21, 75-78), except that 1010 infectious phages particles were used after heating at 65° C. for 5 minutes and that DNA polymerization was done at 65° C. Substrate cross-linking on phage was done by incubating the phage particles with 10 μM maleimidyl-derivatized primer, 50 μM RNA template of SEQ ID NO: 12 in the presence of 10 mM magnesium chloride at 37° C. for 2 hours and polymerization during 2 minutes at 65° C. after addition of 3 μM biotin-dUTP and 1 μM dVTP. The reactions were blocked by addition of one volume of 0.25 M ethylene diamine tetra-acetate. The phage mixture was added to 200 μl of streptavidin-coated superparamagnetic beads (Dynabeads M-280, Dynal). After 30 minutes at room temperature, the beads were washed seven times and resuspended in 200 μl PBS. The phage-bead mixture was incubated for 10 min at 37 ° C. after addition of one-tenth, in volume, of trypsin (0.1 g/l). 1.8 mL of E. coli TG1 was then added for infection during 25 min at 37 ° C. Bacteria were plated on 530 cm2 Petri dishes (Coming). After 12 hours at 30° C., bacteria were scraped from the plate with a 2×TY medium containing ampicillin and about 2×109 cells were used for preparation of the phage particles. RT-Polymerization and Polymerization Activity Assay Using Phage-Polymerase In the following examples, the activity of the different mutant phage-polymerases was assayed by incorporation of radiolabeled dTTP. Example 1 Polyclonal Phage-Polymerases (FIG. 1) In this example, the reverse transcriptase activity of phage-polymerases was assessed as obtained after different rounds of selection in the presence of Mg2+ or Mn2+ ions. In these experiments, two reverse transcription (RT) mixes were used. The final concentration of each component in a reaction was: 10 μM RNA (SEQ ID NO: 12); 5 μM DNA (SEQ ID NO: 13); 0.25 mM dNTP; 3 mM MgCl2 or 2.5 mM MnCl2. Each 1.9 μl aliquot of the reaction mix was further added to 15 μl of phage-polymerases (108 particles) after a given selection round heated for 5 min at 65° C. The solutions were then incubated at 37° C. for 15 min. The reactions were stopped by adding 15 μl of EDTA/formamide containing denaturation solution, heating for 3 min. at 94° C., and placed on ice. The incorporation of alpha 32P-dTTP was determined on 20% polyacrylamide gel; 15 μl of the final reaction volume were loaded. The lane designations in FIG. 1 are as follows: MnCl2 MgCl2 a: phage-polymerases of round 6 h: phage-polymerases of round 6 b: phage-polymerases of round 5 i: phage-polymerases of round 5 c: phage-polymerases of round 4 j: phage-polymerases of round 4 d: phage-polymerases of round 3 k: phage-polymerases of round 3 e: phage-polymerases of round 2 l: phage-polymerases of round 2 f: phage-polymerases of round 1 m: phage-polymerases of round 1 g: phage-polymerases of initial n: phage-polymerases of initial population population This experiment demonstrated that: A RT-activity is present using phage-polymerase obtained after round 5 (i) or 6 (h) of selection in presence of Mg2+. A high RT-activity was detected at the round 3 (d) in the presence of Mn2+ and for further rounds. Example 2 Polyclonal Phage-Polymerases (FIG. 2) In this example, the reverse transcriptase activity of phage-polymerases was assessed as obtained after different rounds of selection in the presence of Mg2+ ions. In these experiments, a reverse transcription (RT) mix was used. The final concentration of each component in a reaction was: 10 μM RNA (SEQ ID NO: 12); 5 μM DNA (SEQ ID NO: 13); 0.25 mM dNTP; 3 mM MgCl2. Each 1.2 μl aliquot of the reaction mix was further mixed with 15 μl of phage-polymerase polymerases (108 particles) after one round of selection round, either not preheated or heated 5 min at 65° C. before reaction of polymerization. The solutions were then incubated at 37° C. for 15 min. The reactions were stopped by adding 15 μl of the denaturation solution, heating for 3 min. at 94° C. and placing on ice. The incorporation of alpha 32P-dTTP was determined on 20% polyacrylamide gel; 15 μl of the final reaction volume were loaded. The positive control was performed with addition of different concentration of commercial AMV reverse transcriptase (Promega). The lane designations in FIG. 2 are as follows: Phage-polymerase heated Phage-polymerase not at 65° C. for 5 min. preheated a: phage-polymerases of initial h: phage-polymerases of initial population population b: phage-polymerases of round 1 i: phage-polymerases of round 1 c: phage-polymerases of round 2 j: phage-polymerases of round 2 d: phage-polymerases of round 3 k: phage-polymerases of round 3 e: phage-polymerases of round 4 l: phage-polymerases of round 4 f: phage-polymerases of round 5 m: phage-polymerases of round 5 g: phage-polymerases of round 6 n: phage-polymerases of round 6 o: control AMV-RT, 1 U p: control AMV-RT, 0.1 U q: control AMV-RT, 0.01 U r: control AMV-RT, 0.001 U This experiment demonstrated that: A RT-activity is present using phage-polymerase obtained after round 5 or 6 of selection preheated for 5 min. at 65° C. (f and g) or not (m and n) as in FIG. 1 in presence of Mg2+. A high RT-activity was detected using 1 unit of AMV-RT (o) but no activity was detected using decreasing concentration of AMV-RT. Example 3 Monoclonal Phage-Polymerases (FIG. 3) In this example, the reverse transcriptase activity of various monoclonal phage-polymerases obtained after round 6 in the presence of Mg2+ ions was assessed. In these experiments, a reverse transcription (RT) mix was prepared in which the final concentration of each component in a reaction was: 10μM RNA (SEQ ID NO: 12); 5 μM DNA (SEQ ID NO: 13); 0.25 mM dNTP; 3 mM MgCl2. Each 1.45 μl aliquot of the reaction mix was further mixed with 15 μl of phage-polymerase heated for 5 min at 65° C. The solutions were then incubated at 37° C. for 20 min. The reactions were stopped by adding 15 μl of denaturation solution, heating for 3 min. at 94° C., and placed on ice. The incorporation of alpha 32P-dTTP was determined on a 20% polyacrylamide gel; 15 μl of the final reaction volume were loaded. The positive control was performed using the AMV-RT (Promega), lane C. The different monoclonal phage-polymerases were obtained among the phage-polymerases of round 6. The phage-polymerases present various DNA-polymerase RNA-dependant activities. The lane designations in FIG. 3 are as follows: s=SEQ ID NO: 38; a=SEQ ID NO: 20; d=SEQ ID NO: 24; g=SEQ ID NO: 28; C=AMV-RT; i=SEQ ID NO: 30; m=SEQ ID NO: 32; n=SEQ ID NO: 34; b=SEQ ID NO: 22; and q=SEQ ID NO: 36. The clones a, b, and d possess a high RT-activity, which were further studied as reported in FIG. 4. Randomly chosen clones from the selected populations were assayed for monoclonal phage-polymerase reverse transcriptase activity and that further sequencing of the corresponding mutant genes revealed identical sequences (for example, 7 clones reported on the figure were found to have the same sequence noted a). Example 4 Monoclonal Phage-Polymerases (FIG. 4) In this example, the reverse transcriptase and the polymerase activities of monoclonal phage-polymerases obtained after the round 6 in the presence of Mg2+ or Mn2+ ions was assessed. In these experiments, the final concentration of each component in a reaction was: 10 μM RNA (SEQ ID NO: 12); 5 μM DNA (SEQ ID NO: 13); 0.25 mM dNTP; 3 mM MgCl2 or 2.5 mM MnCl2; and 1 μM DNA (SEQ ID NO: 14); 1 μM DNA (SEQ ID NO: 13); 0.25 mM dNTP; 3 mM MgCl2 or 2.5 mM MnCl2 2 μl aliquots of the reaction mix were further added to 15 μl of each phage-polymerase pre-heated for 5 min at 65° C. The solutions were then incubated at 37° C. for 15 min. The reactions were stopped by adding 15 μl of denaturation solution, heating 3 min. at 94° C., and placed on ice. The incorporation of alpha 32P-dTTP was determined on polyacrylamide gel; 15 μl of the final reaction volume were loaded. The positive control was performed using the phage Stoffel fragment (e). The lane designations in FIG. 4 are as follows: a=SEQ ID NO: 20; b=SEQ ID NO: 22; d=SEQ ID NO: 24; and e=SEQ ID NO: 26. Three families of phage polymerase were characterized among the phage-polymerases of round 6. The phage-polymerases a and b present a high DNA-polymerase DNA-dependent activity, which is higher than that of Stoffel phage-polymerase. The phage-polymerases b and d present a high DNA-polymerase RNA-dependent activity, which is higher than that of the Stoffel phage-polymerase e (not detectable, see figure) or than the phage-polymerase a, whatever the conditions in the presence of magnesium or of manganese. The phage-polymerase d shows a poor DNA-polymerase DNA-dependent activity, which is lower than the activity of the Stoffel phage-polymerase. Construction and Overproducing Clones Three phagemids corresponding to clones a, b and d on FIG. 4 were isolated from individual colonies of E. coli strain TG1. The plasmid DNA was prepared and purified using Wizard Plus miniprep kits. The phagemids were cleaved with NcoI and NotI restriction endonucleases. The fragments were dephosphorylated with alkaline phosphatase, purified on QIAgen QIAquick and ligated into expression vector pET-28b(+) (Novagen) that had been cleaved with NcoI and NotI and containing a sequence for the thrombin cleavage site between the NotI and XhoI restriction sites (GCGGCCGCACTGGTGCCGCGCGGCAGC CTCGAG; SEQ ID NO: 45). Recombinant plasmids were transformed in E. coli strain BL21 pLysS and plated on 2YT media with kanamycin and chloramphenicol. Correct plasmid constructions were initially identified by restriction analysis of plasmid miniprep. E. coli strain BL21, used as a host for recombinant plasmids to over produce the mutant RT-polymerase, was grown in 2YT medium supplemented with 10 μg/ml kanamycin and 25 μg/ml chloramphenicol to propagate plasmids and 1 mM of isopropyl-1-thio-β-D-galactopyranoside (IPTG) to induce production of enzyme. Purification of Mutant RT-Polymerases Mutants were prepared from 500 ml batches of cells. 2YT media plus kanamycin and chloramphenicol was inoculated with bacteria (containing a recombinant plasmid) freshly picked on a plate and grown at 37° C. to an absorbance at 600 nm of approximately 0.5. Subsequently, IPTG was added to a final concentration of 1 mM and the cultures were allowed to further grow for 5 h. Cells were harvested by centrifugation at 15000 g and 4° C. for 10 min., resuspended in 30 ml of lysis buffer (50 mM Na2HPO4, 300 mM NaCl, 5 mM imidazole, pH=8), lysed 3 times for 45 sec by ultrasound. Cell debris were removed by centrifugation at 10000 g and 4° C. for 15 min. Mutant RT polymerases were recovered from this clarified lysate and purified using Ni-NTA agarose (QIAGEN). Example 5 Purified Mutant RT-Polymerases a, b, and d Used in Polymerase Chain Reaction (FIG. 5) After purification on Ni-NTA agarose, the mutant polymerases were dialyzed in buffer Tris 100 mM, pH=8 and stored at 4° C. PCR mix Component Amount Buffer B 10X (*) 20 μl MgCl2 25 mM 10 μl primer 15 (50 μM) 4 μl primer 16 (50 μM) 4 μl dNTP 25 mM 2 μl Water 157.5 μl Template (Stoffel fragment gene) 2 μl Pfu polymerase (3 U/μl) 0.5 μl (*) See Buffer B composition above The PCR was performed using 19 μl of PCR mix and 0.6 μl of mutant-polymerase, a, b and d. The lanes in the gel appearing in FIG. 5 include the three clones corresponding to clones a, b and d on FIG. 4. In addition, the positive control was performed using the Stoffel fragment polymerase e and commercial Taq DNA polymerase (Promega). The lanes in FIG. 5 are as follows: lane 1: Taq lane 2: a=SEQ ID NO: 20 lane 3: b=SEQ ID NO: 22 lane 4: d=SEQ ID NO: 24 lane 5: e=SEQ ID NO: 26 lane 6: Molecular weight marker Example 6 Purified Mutant RT-Polymerases a, b, and d Used in RT-Polymerase Chain Reaction (FIG. 6) The positive control was performed using the phage-polymerase of AMV-RT (Promega). These studies were performed using the three clones corresponding on clones a, b and d in FIG. 4. The reverse transcription was performed at 65° C. during 1 h using the following conditions. Control RT mix Component Amount RNA from rabbit globin (sigma), 20 μg/ml 1 μl primer 17 (5 μM) 0.4 μl primer 18 (5 μM) 0.4 μl buffer A (**)AMV-RT 5X 3 μl dNTP 2.5 mM 0.8 μl AMV-RT 10 U/μl 3 μl water 6.4 μl (**) See buffer A composition above RT mix Component Amount RNA from rabbit globin (sigma), 20 μg/ml 1 μl primer 17 (5 μM) 0.4 μl primer 18 (5 μM) 0.4 μl MgCl2 25 mM 0.75 buffer C (***) 1.5 μl dNTP 2.5 mM 0.8 μl mutant polymerase a, b, d 3 μl or the Stoffel fragment e water 7.15 μl (***) See buffer C composition above The PCR was performed using PCR 7 (see table 2) and following conditions. PCR mix Component Amount Buffer B 10x 20 μl primer 17 (50 μM) 4 μl primer 18 (50 μM) 4 μl dNTP 2 μl water 164.5 μl Taq DNA polymerase (5 U/μl) 5 μl Pfu polymerase (3 U/μl) 0.5 μl 19 μl aliquot of the PCR mix was added to 1 μl of the RT reaction product. A RT-PCR product of 372 bp was detectable using mutant RT-polymerases b and d. The lanes in the gel appearing in FIG. 6 include the three clones corresponding to clones a, b and d on FIG. 4. In addition, the positive control was performed using the Stoffel fragment polymerase e and the commercial AMV-RT (Promega). The lanes in FIG. 6 are as follows: lane 1: molecular weight marker lane 2: control AMV-RT lane 3: b=SEQ ID NO: 22 lane 4: a=SEQ ID NO: 20 lane 5: e=SEQ ID NO: 26 lane 6: d=SEQ ID NO: 24 Summary of the Taq Sequence Variants Above In the N-terminus of the purified proteins, the signal sequence is not taken in account, the peptide having the sequence MASG4CG4 (SEQ ID NO: 39) has been introduced upstream the sequence SPKA (amino acids 13-16 of SEQ ID NO: 26), which correspond to the Stoffel fragment beginning (S being the amino acid occupying the position number 290 in the Taq polymerase sequence). In the C-terminus of the purified proteins, the sequence AAALVPRGSLEH6 (SEQ ID NO: 40) comprising a site of cleavage by thrombin, as well as a polyhistidine tag has been introduced to facilitate further purification of the protein. Mutations assessment sequence SEQ ID NO: M761V SEQ ID No. “s” 38 M761T, D547G, I584V SEQ ID No. “a” 20 W827R SEQ ID No. “m” 32 W827R, E520G, A608T SEQ ID No. “b” 22 W827R, A517V, T664S, F769S SEQ ID No. “g” 28 M747K, Q698L, P816L SEQ ID No. “n” 34 M747R, W604R, S612N, V730L, SEQ ID No. “d” 24 R736Q, S739N, N483Q, S486Q, T539N, Y545Q, D547T, P548Q, A570Q, D578Q, A597T F749Y, A568V SEQ ID No. “i” 30 F749Y, P550Q, R556S, V740E, V819A SEQ ID No. “q” 36 Numerous modifications and variations on the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the accompanying claims, the invention may be practiced otherwise than as specifically described herein. REFERENCES 1. Bothmann, H. and Pluickthun, A. (1998) Selection for a periplasmic factor improving phage display and functional periplasmic expression. Nat. Biotech. 16, 376-380. 2. Jestin, J. L., Volioti, G. and Winter, G. (2001) Improving the display of proteins on filamentous phage. Res. Microbiol. 152, 187-191. 3. Holland, M. M., Leib, T. K., and Gerlt, J. A. (1988) Isolation and characterization of a small catalytic domain released from the adenylate cyclase from Escherichia coli by digestion with trypsin. J Biol. Chem. 263, 14661-14668. 4. Ladant, D., Glaser, P., and Ullmann, A. (1992) Insertional mutagenesis of Bordetella pertussis adenylate cyclase. J. Biol. Chem. 267, 2244-2250. 5. Hoogenboom, H. R., Griffiths, A. D., Johnson, K. S., et al. (1991) Multi-subunit proteins on the surface of filamentous phage: methodologies for displaying antibody Fab heavy and light chains. Nuc. Acids Res. 19, 4133-4137. 6. Kristensen, P. and Winter, G. (1998) Proteolytic selection for protein folding using filamentous bacteriophages. Fold. Design 3, 321-328. 7. Lei, S. P., Lin, H. C., Wang, S. S., Callaway, J., et al. (1987) Characterization of the Erwinia carotovora ; pelB gene and its product pectate lyase. J. Bacteriol. 169, 4379-4383. 8. Tesar, M., Beckmann, C., Rottgen, P., et al. (1995) Monoclonal antibody against pIII of filamentous phage: an immunological tool to study pill fusion protein expression in phage display systems. Immunotechnology 1, 53-64. 9. Pedersen, H., Hölder, S., Sutherlin, D. P., et al. (1998) A method for directed evolution and functional cloning of enzymes. Proc. Natl. Acad. Sci. USA 95, 10523-10528. 10. Jestin, J. L., Kristensen, P., and Winter, G. (1999) A method for the selection of catalytic activity using phage display and proximity coupling. Angew. Chem. Int. Ed. 38, 1124-1127. 11. Dematris, S., Huber, A., et al. (1999) A strategy for the isolation of catalytic activities from repertoires of enzymes displayed on phage. J. Mol. Biol. 286, 617-633. 12. Heinis, C., Huber, A. et al. (2001) Selection of catalytically active biotin ligase and trypsin mutants by phage display. Protein Eng. 14, 1043-1052. 13. Atwell, S. and Wells, J. A. (1999) Selection for improved subtiligases by phage display. Proc. Natl. Acad. Sci. USA 96, 9497-9502. 14. Ponsard, I., Galleni, M., Soumillion, P., Fastrez, J., Selection of metalloenzymes by catalytic activity using phage display and catalytic elution. Chembiochem. 2, 253-259. 15. Lawyer, F. C., Stoffel, S., Saiki, R. K., et al. (1989) Isolation, characterisation and expression in E. coli of the DNA polymerase gene from Thermus aquaticus. J. Biol. Chem. 264, 6427-6437. 16. Marks et al., (1992) Molecular evolution of proteins on filamentous phage, Mimicking the strategy of the immune system. J. Biol. Chem. 267, 16007-16010. 17. Vichier-Gurre & Jestin, (2003) Iterative cycles of in vitro protein selection for DNA polymerase activity, Biocat. & Biotransf. 21, 75-78. 18. Fastrez et al., (2002) Investigation of phage display for the directed evolution of enzymes,” In: Brackmann, S. and Johnsson, K. eds., Directed Molecular Evolution of Proteins (Wiley VCH, Weinheim), pp 79-110 19. Ponsard et al. (2001) Selection of metalloenzymes by catalytic activity using phage display and catalytic elution. Chembiochem. 2, 253-259. 20. Ting et al. (2001) Phage-display evolution of tyrosine kinases with altered nucleotide specificity. Biopol. 60, 220-228. 21. Xia et al. (2002) Directed evolution of novel polymerase activities: mutation of a DNA polymerase into an efficient RNA polymerase. Proc. Natl. Acad. Sci. USA 99, 6597-6602. 22. Rougeon, F., Kourilsky, P., Mach, B. Insertion of a rabbit beta-globin gene sequence into an E. coli plasmid Nucl. Acids Res., 1975, 2, 2365-2378. 23. Rougeon, F., Mach, B. Stepwise biosynthesis in vitro of globin genes from globin mRNA by DNA polymerase of avian myeloblastosis virus Proc. Natl. Acad. Sci. USA, 1976, 73, 3418-3422. 24. Grabko, V. I., Chistyakova, L. G., Lyapustin, V. N., Korobko, V. G., Miroshnikov, A. I., Reverse transcription, amplification and sequencing of poliovirus RNA by Taq DNA polymerase FEBS Letters, 1996, 387, 189-192. 25. Perler, F., Kumar, S., Kong, H. Thermostable DNA polymerases Adv. Prot. Chem., 1996, 48, 377-435. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention provides a method for obtaining thermostable enzymes. The present invention also provides variants of DNA polymerase I from Thermus aquaticus. The present invention further provides methods of identifying mutant DNA polymerases having enhanced catalytic activity. The present invention also provides polynucleotides, expression systems, and host cells encoding the mutant DNA polymerases. Still further, the present invention provides a method to carry out reverse transcriptase-polymerase chain reaction (RT-PCR) and kits to facilitate the same. 2. Discussion of the Background Filamentous phage display is commonly used as a method to establish a link between a protein expressed as a fusion with a phage coat protein and its corresponding gene located within the phage particle (Marks et al., J. Biol. Chem. (1992) 267, 16007-16010). The use of filamentous phage particles as a chemical reagent provides further a strategy to create a complex between an enzyme, its gene and a substrate (Jestin et al., Angew. Chem. Int. Ed. (1999) 38, 1124-1127). This substrate can be cross-linked on the surface of filamentous phage using the nucleophilic properties of coat proteins. If the enzyme is active, conversion of the substrate to the product yields a phage particle cross-linked with the product, which can be captured by affinity chromatography (see discussion in Vichier-Guerre & Jestin, Biocat. & Biotransf. (2003) 21, 75-78). Several similar approaches based on product formation for the isolation of genes encoding enzymes using phage display have been described in the literature for various enzymes (Fastrez et al., (2002) In: Brackmann, S. and Johnsson, K. eds., Directed Molecular Evolution of Proteins (Wiley VCH, Weinheim), pp 79-110). These in vitro selections of proteins for catalytic activity are well suited for use with large repertoires of about 10 8 proteins or more. Several libraries of enzyme variants on phage have been constructed and catalytically active proteins with wild type like activities have been isolated (Atwell & Wells (1999) Proc. Natl. Acad. Sci. USA 96, 9497-9502; Heinis et al. (2001) Prot. Eng. 14, 1043-1052; Ponsard et al. (2001) Chembiochem. 2, 253-259; Ting et al. (2001) Biopol. 60, 220-228.). Mutants with different substrate specificities have been also obtained (Xia et al. (2002) Proc. Natl. Acad. Sci. USA 99, 6597-6602.). In these studies, the fraction of active variants in the libraries can be large and it remains unclear how rare an enzyme can be in the initial protein library so as to be selected after iterative selection cycles. Accordingly, there remains a critical need for an efficient process for making and identifying thermostable enzymes possessing a desired catalytic activity. Reverse transcriptases are enzymes that are present generally in certain animal viruses (i.e., retroviruses), which are used in vitro to make complementary DNA (cDNA) from an mRNA template. Practically, reverse transcriptases have engendered significant interest for their use in reverse transcriptase-polymerase chain reaction (RT-PCR). As such, these proteins lend themselves to be a model system for development of an efficient method of making thermostable enzymes having a desired activity. RNA generally contains secondary structures and complex tertiary sections, accordingly it is highly desired that the RNA be copied in its entirety by reverse transcription to ensure that integrity of cDNA is maintained with high accuracy. However, due to the often complicated secondary and tertiary structures of RNA, the denaturation temperatures are generally about 90° C. and, as such, the reverse transcriptase must be capable of withstanding these extreme conditions while maintaining catalytic efficiency. The classically utilized enzymes for RT-PCR have been isolated from the AMV (Avian myeloblastosis virus) or MMLV (Moloney murine leukemia virus); however, these enzymes suffer from a critical limitation in that they are not thermostable. In fact, the maximum temperature tolerated by most commercially available reverse transcriptases is about 70° C. One common approach to overcome this limitation in the existing technology with the previously described polymerases has been the use of a protein chaperones in addition to the polymerase. However, this method leads to problems associated with environmental compatibility metal ion requirements, multi-stage procedures, and overall inconvenience. Accordingly, an alternative strategy has been to use thermostable reverse transcriptases. This approach makes it possible to perform multiple denaturation and reverse transcription cycles using only a single enzyme. To this end, the DNA-dependent DNA polymerase I of Thermus aquaticus (i.e., Taq polymerase), is thermostable and has reverse transcriptase activity only in the presence of manganese. However, when the manganese ion concentration is maintained in the millimolar range the fidelity of the enzyme is affected. It has been suggested that the thermostable DNA-dependent DNA polymerase of Bacillus stearothermophilus has reverse transcriptase activity, even in absence of magnesium, but in this case it is necessary to add a thermostable DNA polymerase for the PCR. Therefore, there remains a critical need for high efficiency, thermostable enzymes that are capable of catalyzing reverse transcription and subsequent DNA polymerization in “one-pot” RT-PCR. Accordingly, the present invention provides an isolated population of thermostable reverse transcriptases, which are active in absence of manganese, by directed evolution of the Stoffel fragment of the Taq polymerase. | <SOH> SUMMARY OF THE INVENTION <EOH>It is an object of the present invention to provide a method of identifying thermostable mutant polypeptides having a catalytic activity by: a) packaging a vector in which a gene or fragment thereof encoding variants of a catalytic domain responsible for the catalytic activity fused to a gene encoding a phage coat protein, b) isolation and purification of phage particles; c) heating the phage-mutant polypeptide at a temperature ranging from 50° C. to 90° C. for a time ranging from less than 1 minute to several hours d) cross-linking a specific substrate with a phage particle e) forming a reaction product from the substrate catalyzed by the thermostable mutant protein on phage, wherein the temperature is optionally regulated to be the same or greater or lower than the temperature of (c) f) selecting the phage particles comprising a variant nucleotidic sequence encoding for the catalytic domain responsible for the catalytic activity at the regulated temperature, by capturing the reaction product or screening for said reaction product, g) infecting E. coli with the phage particles selected at step (f), h) incubating the infected E. coli; and i) assessing catalytic activity of the proteins corresponding to isolated genes. It is an object of the present invention to provide a thermostable mutant DNA polymerase having at least 80% homology to the Stoffel fragment (SEQ ID NO: 26) of DNA polymerase I obtained from Thermus aquaticus. To this end, the present invention provides thermostable polypeptides having at least 80% homology to SEQ ID NO: 26, wherein said polypeptide has at least one mutation selected from the group consisting of a mutation in amino acids 738 to 767 of SEQ ID NO:26, A331T, S335N, M470K (position 747 of the Taq polymerase wild-type sequence), M470R (position 747 of the Taq polymerase wild-type sequence), F472Y (position 749 of the Taq polymerase wild-type sequence), M484V (position 761 of the Taq polymerase wild-type sequence), M484T (position 761 of the Taq polymerase wild-type sequence), and W550R (position 827 of the Taq polymerase wild-type sequence), and wherein said polypeptide has improved DNA polymerase activity and retains 5′-3′ exonuclease activity. In an object of the present invention, the 3′-5′ exonuclease activity of the mutant polypeptide is inactive. In an object of the present invention, the thermostable mutant DNA polymerase also has a mutation at one or more position selected from A331, L332, D333, Y334, and S335 of SEQ ID NO: 26 (positions 608-612 of the Taq polymerase wild-type sequence). In a particular object of the present invention, the mutant DNA polymerase has one of the following sequences: SEQ ID NO: 20, SEQ ID NO: 22, SEQ ID NO: 24, SEQ ID NO: 28, SEQ ID NO: 30, SEQ ID NO: 32, SEQ ID NO: 34, SEQ ID NO: 36, and SEQ ID NO: 38. Further, in another object of the present invention are polynucleotides that encode for the aforementioned thermostable mutant DNA polymerases. In yet another object of the present invention is a kit for DNA amplification, which contains: (a) one or more of the aforementioned thermostable mutant DNA polymerases; (b) a concentrated buffer solution, wherein when said concentrated buffer is admixed with the isolated polypeptide the overall buffer concentration is 1×; (c) one or more divalent metal ion (e.g., Mg 2+ or Mn 2+ ); and (d) deoxyribonucleotides. In yet another object of the present invention is a method of reverse transcribing an RNA by utilizing the inventive thermostable mutant DNA polymerases. In still a further object of the present invention is a phage-display method for identifying thermostable mutant DNA polymerases in which the Stoffel fragment has been mutated, while the DNA polymerase activity and 5′-3′ exonuclease activity has been maintained and/or enhanced. The above objects highlight certain aspects of the invention. Additional objects, aspects and embodiments of the invention are found in the following detailed description of the invention. | 20040227 | 20080826 | 20050901 | 72082.0 | 0 | WILDER, CYNTHIA B | METHODS FOR OBTAINING THERMOSTABLE ENZYMES, DNA POLYMERASE I VARIANTS FROM THERMUS AQUATICUS HAVING NEW CATALYTIC ACTIVITIES, METHODS FOR OBTAINING THE SAME, AND APPLICATIONS OF THE SAME | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,787,224 | ACCEPTED | System and method for generalized imaging utilizing a language agent and encapsulated object oriented polyphase preboot execution and specification language | The present invention discloses a method and system for specifying and executing computing tasks in a preboot execution environment in general, and, in particular, a method and system for generalized imaging utilizing a language agent and encapsulated object oriented polyphase preboot execution and specification language. The target customization is advantageously accomplished by encapsulating target dependent parameters in specification files. The target specific parameters are resolved at appropriate execution time when the parameter information becomes available. Such approach simplifies specification of complex tasks to a merely few lines of code. The approach of the present invention nevertheless affords reliable, robust, and accurate performance, because the pertinent parametric information are resolved only when they can be accurately ascertained. Furthermore, the specification encapsulations are themselves a part of the image set, providing self-describing images with self-contained imaging methods. The result is a robust, reliable, flexible, and simple method and system for centralized maintenance and management of client devices in a networked enterprise computing environment with a lower total cost of ownership than existing products. | 1. A system for executing computing tasks in a preboot execution environment, comprising a language agent with a preboot execution language interpreter. 2. The system of claim 1, wherein the preboot execution language interpreter is an object-oriented language interpreter. 3. The system of claim 1, further comprising at least one specification for performing at least one computing task in the preboot execution environment, wherein the language agent interprets the at least one specification for performing at least one computing task in the preboot execution environment, and performs the at least one computing task specified. 4. The system of claim 3, wherein the at least one specification is an encapsulation, encapsulating parameters resolved by the preboot execution language interpreter at execution time. 5. The system of claim 4, wherein the encapsulated parameters are parametric behaviors as well as parametric data. 6. A system for image installation in a preboot execution environment, comprising: a language agent with a preboot execution language interpreter. 7. The system of claim 6, wherein the preboot execution language interpreter is an object-oriented language interpreter. 8. The system of claim 6, further comprising: at least one specification for performing at least one task for image installation in the preboot execution environment, wherein the language agent interprets the at least one specification, and performs the at least one task specified. 9. The system of claim 8, wherein the at least one specification is an encapsulation, encapsulating parameters resolved by the preboot execution language interpreter at execution time. 10. The system of claim 9, wherein the encapsulated parameters are parametric behaviors as well as parametric data. 11. The system of claim 9, wherein an image set for image installation itself is a self-describing encapsulation, containing the at least one specification as an encapsulation which encapsulates parameters resolved by the preboot execution language interpreter at execution time. 12. A system for remote imaging in a preboot execution environment, comprising: a language agent with a preboot execution language interpreter. 13. The system of claim 12, wherein the preboot execution language interpreter is an object-oriented language interpreter. 14. The system of claim 12, further comprising: at least one specification for performing at least one task for remote imaging over a network in the preboot execution environment, wherein the language agent interprets the at least one specification, and performs the at least one task specified. 15. The system of claim 14, wherein the at least one specification is an encapsulation, encapsulating parameters resolved by the preboot execution language interpreter at execution time. 16. The system of claim 15, wherein the encapsulated parameters are parametric behaviors as well as parametric data. 17. The system of claim 15, wherein an image set for remote imaging itself is a self-describing encapsulation, containing the at least one specification as an encapsulation which encapsulates parameters resolved by the preboot execution language interpreter at execution time. 18. A system for remote booting over a network, comprising: a language agent with a preboot execution language interpreter. 19. The system of claim 18, wherein the preboot execution language interpreter is an object-oriented language interpreter. 20. The system of claim 18, further comprising: at least one specification for performing at least one task in a preboot execution environment for remotely booting a computer over a network, wherein the language agent interprets the at least one specification, and performs the at least one task specified. 21. The system of claim 20, wherein the at least one specification is an encapsulation, encapsulating parameters resolved by the preboot execution language interpreter at execution time. 22. The system of claim 21, wherein the encapsulated parameters are parametric behaviors as well as parametric data. 23. The system of claim 21, wherein an image set for remote booting itself is a self-describing encapsulation, containing the at least one specification as an encapsulation which encapsulates parameters resolved by the preboot execution language interpreter at execution time. 24. A method for executing computing tasks in a preboot execution environment, comprising the steps of: providing a language agent with a preboot execution language interpreter; providing at least one specification for performing at least one computing task in the preboot execution environment; interpreting by the language agent the at least one specification for performing at least one computing task in the preboot execution environment; and performing the at least one computing task specified. 25. The method of claim 24, wherein the preboot execution language interpreter is an object-oriented language interpreter. 26. The method of claim 24, wherein the at least one specification is an encapsulation, encapsulating parameters resolved by the preboot execution language interpreter at execution time. 27. The method of claim 26, wherein the encapsulated parameters are parametric behaviors as well as parametric data. 28. A method for image installation in a preboot execution environment, comprising the steps of: providing a language agent with a preboot execution language interpreter; providing at least one specification for performing at least one task for image installation in the preboot execution environment; interpreting by the language agent the at least one specification for performing at least one task for image installation in the preboot execution environment; and performing the at least one task for image installation specified. 29. The method of claim 28, wherein the preboot execution language interpreter is an object-oriented language interpreter. 30. The method of claim 28, wherein the at least one specification is an encapsulation, encapsulating parameters resolved by the preboot execution language interpreter at execution time. 31. The method of claim 30, wherein the encapsulated parameters are parametric behaviors as well as parametric data. 32. The method of claim 30, wherein an image set for image installation itself is a self-describing encapsulation, containing the at least one specification as an encapsulation which encapsulates parameters resolved by the preboot execution language interpreter at execution time. 33. A method for remote imaging in a preboot execution environment, comprising the steps of: providing a language agent with a preboot execution language interpreter; providing at least one specification for performing at least one task for remote imaging in the preboot execution environment; interpreting by the language agent the at least one specification for performing at least one task for remote imaging in the preboot execution environment; and performing the at least one task for remote imaging specified. 34. The method of claim 33, wherein the preboot execution language interpreter is an object-oriented language interpreter. 35. The method of claim 33, wherein the at least one specification is an encapsulation which encapsulates parameters resolved by the preboot execution language interpreter at execution time. 36. The method of claim 35, wherein the encapsulated parameters are parametric behaviors as well as parametric data. 37. The method of claim 35, wherein an image set for remote imaging itself is a self-describing encapsulation, containing the at least one specification as an encapsulation which encapsulates parameters resolved by the preboot execution language interpreter at execution time. 38. A method for remote booting in a preboot execution environment, comprising the steps of: providing a language agent with a preboot execution language interpreter; providing at least one specification for performing at least one task for remote booting in the preboot execution environment; interpreting by the language agent the at least one specification for performing at least one task for remote booting in the preboot execution environment; and performing the at least one task for remote booting specified. 39. The method of claim 38, wherein the preboot execution language interpreter is an object-oriented language interpreter. 40. The method of claim 38, wherein the at least one specification is an encapsulation which encapsulates parameters resolved by the preboot execution language interpreter at execution time. 41. The method of claim 40, wherein the encapsulated parameters are parametric behaviors as well as parametric data. 42. The method of claim 40, wherein an image set for remote booting itself is a self-describing encapsulation, containing the at least one specification as an encapsulation which encapsulates parameters resolved by the preboot execution language interpreter at execution time. 43. A system for specifying computing tasks in a preboot execution environment, comprising a language agent with a preboot execution specification generator. 44. The system of claim 43, further comprising a definition for at least one specification for performing at least one computing task in a preboot execution environment, wherein the at least one specification is generated from the definition by the language agent with a preboot execution specification generator. 45. The system of claim 43, wherein the preboot execution specification generator is an object-oriented language code generator. 46. The system of claim 44, wherein the at least one specification is an encapsulation, encapsulating parameters resolved at execution time. 47. The system of claim 46, wherein the encapsulated parameters are parametric behaviors as well as parametric data. 48. A system for specifying tasks for image installation in a preboot execution environment, comprising a language agent with a preboot execution specification generator. 49. The system of claim 48, further comprising a definition for at least one specification for performing at least one task for image installation in a preboot execution environment, wherein the at least one specification is generated from the definition by the language agent with a preboot execution specification generator. 50. The system of claim 48, wherein the preboot execution specification generator is an object-oriented language code generator. 51. The system of claim 48, wherein the at least one specification is an encapsulation, encapsulating parameters resolved at execution time. 52. The system of claim 51, wherein the encapsulated parameters are parametric behaviors as well as parametric data. 53. The system of claim 51, wherein the at least one specification which is an encapsulation is a part of an image set for image installation, which henceforth renders the image set itself to be a self-describing encapsulation, encapsulating parameters resolved at execution time. 54. A system for specifying remote imaging tasks in a preboot execution environment, comprising a language agent with a preboot execution specification generator. 55. The system of claim 54, further comprising a definition for at least one specification for performing at least one task for remote imaging in a preboot execution environment, wherein the at least one specification is generated from the definition by the language agent with a preboot execution specification generator. 56. The system of claim 54, wherein the preboot execution specification generator is an object-oriented language code generator. 57. The system of claim 54, wherein the at least one specification is an encapsulation, encapsulating parameters resolved at execution time. 58. The system of claim 57, wherein the encapsulated parameters are parametric behaviors as well as parametric data. 59. The system of claim 57, wherein the at least one specification which is an encapsulation is a part of an image set for remote imaging, which henceforth renders the image set itself to be a self-describing encapsulation, encapsulating parameters resolved at execution time. 60. A system for specifying remote booting tasks in a preboot execution environment, comprising a language agent with a preboot execution specification generator. 61. The system of claim 60, further comprising a definition for at least one specification for performing at least one task for remote booting in a preboot execution environment, wherein the at least one specification is generated from the definition by the language agent with a preboot execution specification generator. 62. The system of claim 60, wherein the preboot execution specification generator is an object-oriented language code generator. 63. The system of claim 60, wherein the at least one specification is an encapsulation, encapsulating parameters resolved at execution time. 64. The system of claim 63, wherein the encapsulated parameters are parametric behaviors as well as parametric data. 65. The system of claim 63, wherein the at least one specification which is an encapsulation is a part of an image set for remote booting, which henceforth renders the image set itself to be a self-describing encapsulation, encapsulating parameters resolved at execution time. 66. A method for specifying computing tasks in a preboot execution environment, comprising the steps of: providing a language agent with a preboot execution specification generator; providing at least one definition for at least one computing task in a preboot execution environment; and generating a preboot execution specification from the at least one definition utilizing the language agent with a preboot execution specification generator. 67. The method of claim 66, wherein the preboot execution specification generator is an object-oriented language code generator. 68. The method of claim 66, wherein the preboot execution specification is an encapsulation, encapsulating parameters resolved at execution time. 69. The method of claim 68, wherein the encapsulated parameters are parametric behaviors as well as parametric data. 70. A method for specifying computing tasks for image installation in a preboot execution environment, comprising the steps of: providing a language agent with a preboot execution specification generator; providing at least one definition for at least one computing task for image installation in a preboot execution environment; and generating a preboot execution specification from the at least one definition utilizing the language agent with a preboot execution specification generator. 71. The method of claim 70, wherein the preboot execution specification generator is an object-oriented language code generator. 72. The method of claim 70, wherein the preboot execution specification is an encapsulation, encapsulating parameters resolved at execution time. 73. The method of claim 72, wherein the encapsulated parameters are parametric behaviors as well as parametric data. 74. The method of claim 72, wherein the preboot execution specification, which is an encapsulation, is a part of an image set for image installation, which henceforth renders the image set itself to be a self-describing encapsulation, encapsulating parameters resolved at execution time. 75. A method for specifying remote imaging in a preboot execution environment, comprising the steps of: providing a language agent with a preboot execution specification generator; providing at least one definition for at least one computing task for remote imaging in a preboot execution environment; and generating a preboot execution specification from the at least one definition utilizing the language agent with a preboot execution specification generator. 76. The method of claim 75, wherein the preboot execution specification generator is an object-oriented language code generator. 77. The method of claim 75, wherein the preboot execution specification is an encapsulation, encapsulating parameters resolved at execution time. 78. The method of claim 77, wherein the encapsulated parameters are parametric behaviors as well as parametric data. 79. The method of claim 77, wherein the preboot execution specification, which is an encapsulation, is itself a part of an image set for remote imaging, which henceforth renders the image set itself to be a self-describing encapsulation. 80. A method for specifying remote booting operations in a preboot execution environment, comprising the steps of: providing a language agent with a preboot execution specification generator; providing at least one definition for at least one computing task for remote booting in a preboot execution environment; and generating a preboot execution specification from the at least one definition utilizing the language agent with a preboot execution specification generator. 81. The method of claim 80, wherein the preboot execution specification generator is an object-oriented language code generator. 82. The method of claim 80, wherein the preboot execution specification is an encapsulation, encapsulating parameters resolved at execution time. 83. The method of claim 82, wherein the encapsulated parameters are parametric behaviors as well as parametric data. 84. The method of claim 82, wherein the preboot execution specification, which is an encapsulation, is itself a part of an image set for remote booting, which henceforth renders the image set itself to be a self-describing encapsulation. 85. A system for encapsulated platform imaging, comprising: a language agent with an encapsulated language interpreter for executing an encapsulation, wherein the encapsulation contains all instructions and data necessary to install an operating system onto a computing device. 86. The system of claim 85, further comprising: a logical connection, wherein the language agent with an encapsulated language interpreter and the encapsulation is provided over the logical connection. 87. The system of claim 86, wherein the logical connection is a computer readable medium. 88. The system of claim 87, further comprising: a bootable interface on the computer readable medium. 89. The system of claim 86, wherein the logical connection is a network connection. 90. The system of claim 89, further comprising: a bootable interface on the network connection. 91. The system of claim 90, wherein the bootable interface on the network connection is a Preboot Execution Environment (PXE) implementation. 92. A method for encapsulated platform imaging, comprising the steps of: providing an encapsulation which contains all instructions and data necessary to install an operating system onto a computing device; providing a language agent with an encapsulated language interpreter for executing the encapsulation; and executing the encapsulation to install the operating system onto the computing device. 93. The method of claim 92, wherein the encapsulation and the language interpreter are provided over a logical connection. 94. The method of claim 93, wherein the logical connection is a computer readable medium. 95. The method of claim 94, further comprising the steps of: providing a bootable interface on the computer readable medium. 96. The method of claim 95, further comprising the steps of: booting from the computer readable medium; loading the language agent with an encapsulated language interpreter for executing the encapsulation from the computer readable medium; and loading the encapsulation from the computer readable medium before executing the encapsulation. 97. The method of claim 93, wherein the logical connection is a network connection. 98. The method of claim 97, further comprising the steps of: providing a bootable interface on the network connection. 99. The method of claim 98, further comprising the steps of: booting over the network connection; loading the language agent with an encapsulated language interpreter for executing the encapsulation over the network connection; and loading the encapsulation over the network connection before executing the encapsulation. 100. The method of claim 98, wherein the bootable interface on the network connection is a Preboot Execution Environment (PXE) implementation. 101. A system for encapsulated platform imaging, comprising: a language agent with an encapsulation generator for defining and creating an encapsulation, wherein the encapsulation contains all instructions and data necessary to install an operating system onto a computing device. 102. A method for encapsulated platform imaging, comprising the steps of: providing a language agent with an encapsulation generator; providing a definition for an encapsulation; and generating from the definition an encapsulation containing all instructions and data necessary to install an operating system onto a computing device by utilizing the language agent with an encapsulation generator. 103. A system for executing computing tasks in a preboot execution environment, comprising the steps of: means for providing a language agent with a preboot execution language interpreter; means for providing at least one specification for performing at least one computing task in the preboot execution environment; means for interpreting by the language agent the at least one specification for performing at least one computing task in the preboot execution environment; and means for performing the at least one computing task specified. 104. A system for specifying computing tasks in a preboot execution environment, comprising: means for providing a language agent with a preboot execution specification generator; means for providing at least one definition for at least one computing task in a preboot execution environment; and means for generating a preboot execution specification from the at least one definition utilizing the language agent with a preboot execution specification generator. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to specifying and executing computing tasks in a preboot execution environment, and specifically to generalized imaging utilizing a language agent and encapsulated object oriented preboot execution and specification language. 2. Description of the Related Art Network-based computing has been gaining popularity in recent years as a more desirable approach to managing enterprise computing needs. Ranging from network-managed PCs, network computers, and thin-clients, network-based computing is largely motivated by the need to reduce the cost of providing IT services (known as the Total Cost of Ownership, TCO) in networked computing environments. It is well known in the industry that the most expensive part of providing computing resources to end-users is not the cost of the computing hardware and software but the cost of on-going maintenance and management. See, Thin Client Benefits, Newburn Consulting (2002); Total Cost of Application Ownership, The Tolly Group Whitepaper (1999); TCO Analyst: A White Paper on GartnerGroup's Next Generation Total Cost of Ownership Methodology, GartnerConsulting (1997). According to the well known studies, network-based computing approach dramatically reduces the TCO by centralizing the maintenance and management functions of IT services, thereby reducing the recurring cost of on-going maintenance and management. A key component of network-based computing is Remote Imaging, that is, installing images on client computers from centrally managed image servers. Remote Imaging is also synonymous to or closely related to Remote Image Installation and Remote Device Management. The basic idea is that centralized maintenance and management of client computers is accomplished by installing or delivering operating system or application images from a centrally managed servers. Existing technologies such as Microsoft Remote Installation Service, Symantec Ghost, and Rapport Device Management, all provide a method of remote imaging. For remote imaging of operating system components, remote imaging operation is usually initiated during a preboot phase. In other words, it is desirable to transfer operating system images to the client computer before it boots so that the client computer boots with the newly installed operating system images or components. Clearly, this preboot phase is the most critical aspect of remote imaging, as the client computer will not function properly at all if wrong operating system image or components were delivered. In a network with significant number of client computers or devices, the preboot phase of remote imaging presents special challenges due to numerous types of devices or computers that need to be managed. For example, the types of machines and corresponding images or components must be ascertained during the preboot phase where none of the typical operating system utilities or application tools are available. Ideally, what is needed is a tool that runs at the client computers during preboot because the client machine is the best place to ascertain what hardware it has and what operating system and software it needs. Furthermore, a maximum flexibility would be afforded by a generalized specification language for specifying and executing computing tasks during the preboot phase. Although preboot imaging and operating system installation is a complex process, much of the process can be parameterized at some abstract level. For example, installation of device drivers, often the most challenging part of installation, can be parameterized as: if X device is found, install Y device driver file. Moreover, overall scheme of operation of remote imaging may be quite similar for many types of devices, e.g., downloading bootstrap code, OS kernel, device drivers, system DLLs, etc. Thus, such operation can be parameterized if the unknown parameters are resolved at the client side by the client devices during execution of remote imaging operations. However, no vendor currently provides a generalized specification language for the preboot execution environment. Without a generalized specification language for the preboot execution environment, the specification and management of images and components at the central image server is a highly complex process with many inherent risks. The device type of the clients must be ascertained beforehand, and images and components must be prepared for each device types within which all devices must have identical hardware. Then, the client device type must be verified when the images and components are delivered to the client devices. The complexities and difficulties of this process is mainly attributable to information mismatch—that is, trying to manage at the server side operations which critically depends on information at the client side. Thus, a generalized specification language for the preboot execution environment which runs at the client machines will also greatly simplify the management functions at the central server. Instead of complex scripts and programs to prepare images and components, all that is needed is a simple specification that provides: if x, y, z hardware or configuration is found, perform X, Y, Z tasks. It can be seen, then, there is a need in the field for a system and a method for specifying and executing imaging tasks in a preboot execution environment. SUMMARY OF THE INVENTION Accordingly, the present invention addresses the foregoing need by providing a system and method for specifying and executing computing tasks in a preboot execution environment in general, and by providing, in particular, a method and system for generalized imaging utilizing a language agent and encapsulated object oriented preboot execution and specification language. According to one aspect of the invention, the present invention is a system for executing computing tasks in a preboot execution environment, comprising a language agent with a preboot execution language interpreter. The language agent interprets specifications for performing computing tasks in the preboot execution environment, and performs the specified computing tasks. The preboot execution language interpreter can be an object-oriented language interpreter, and the specification can be an encapsulation, encapsulating parameters resolved by the preboot execution language interpreter at execution time. The computing tasks can be those for accomplishing general image installation, platform imaging, remote imaging, remote booting, preboot computer diagnostics, and preboot device management. According to another aspect of the invention, the present invention is a system for specifying computing tasks in a preboot execution environment, comprising a language agent with a preboot execution specification generator. The preboot execution specification generator can be an object-oriented language code generator, and the generated specifications can be encapsulations, encapsulating parameters resolved at execution time. The computing tasks specified can be those for accomplishing general image installation, platform imaging, remote imaging, remote booting, preboot computer diagnostics, and preboot device management. According to yet another aspect of the invention, the present invention is a system for encapsulated platform imaging, comprising a language agent with an encapsulated language interpreter for executing an encapsulation, wherein the encapsulation contains all instructions and data necessary to install an operating system onto a computing device. Imaging of an entire platform is accomplished through a single, self-describing encapsulation instance by executing or interpreting the self-describing encapsulation by the language agent with an encapsulated language interpreter. Encapsulated platform imaging of the present invention provides several advantages over existing methods. With existing technologies, such as Ghost or Rapport, the applications or software programs utilized to accomplish imaging is separate from the program code, as well as from the data or component images necessary for imaging. The intelligence of the application is relied upon to place the component images onto a client to obtain the state desired on the client machine. Thus, entirely different set of program code is required for each different type of platforms; and the applications, the program codes, and the component images must be maintained separately. A set of component images must be preserved along with the corresponding programs that image a particular client device type. In contrast, according to the present invention, only a single encapsulation is required to obtain the same desired state on the client device. Since all target dependent information are parameterized and encapsulated, the same class-object definition can be used to accomplish platform imaging for any platform. Encapsulated platform imaging is a self-contained as well as self-describing method to accomplish platform imaging. It can be seen, then, the present invention provides a more robust, reliable, and accurate execution or performance of specified computing tasks, as the target specific parameters are resolved only when the parameterized information becomes available at the appropriate phase to discover the pertinent information. The result is a robust, reliable, flexible, and simple method and system for centralized maintenance and management of client devices in a networked enterprise computing environment with a lower total cost of ownership than existing products. Other and further objects and advantages of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS Referring now to the drawings in which like reference numbers represent corresponding parts throughout: FIG. 1 illustrates an overview of a system according to the present invention; FIG. 2 illustrates a preboot execution environment according to the present invention; FIG. 3 illustrates downloading and operation of a language agent at a client computer according to the present invention; FIG. 4 illustrates a logical view of downloading a language agent according to the present invention; FIG. 5 illustrates downloading a specification file according to the present invention; FIG. 6 illustrates downloading a series of specification files according to the present invention; FIG. 7 illustrates a conceptual overview of logical operation of an encapsulated object-oriented polyphase language according to the present invention; FIG. 8a to FIG. 8c show example code for generating a polyphase encapsulation according to the present invention; and FIG. 9 illustrates a polyphase encapsulation generated by the example code shown in FIG. 8a to FIG. 8c according to the present invention. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 illustrates an overview of a system according to the present invention. As shown in FIG. 1, the system environment in which the present invention operates comprises Image Server (110), Server Language Agent (112), Specification and Image (114) generated by Server Language Agent (112), Client Computer (120), Client Language Agent (122), and Network (130). As also shown in FIG. 1, Specification and Image (114) generated by Server Language Agent (112) is delivered to Client Computer (120) over Network (130), and processed by Client Language Agent (122) to perform computing tasks specified in Specification and Image (114). In one aspect of the invention, the present invention is a system for executing computing tasks in a preboot execution environment, comprising a language agent with a preboot execution language interpreter. As well known to those skilled in the art, a preboot execution environment is a computing environment at a computer before the computer completes booting—i.e., completes loading an operating system (OS). FIG. 2 illustrates a preboot execution environment according to the present invention. As shown in FIG. 2, a preferred embodiment of the present invention operates in the Preboot Execution Environment (PXE). PXE is a widely-adopted industry standard for network booting or remote booting over a network that provides a way for network cards to initiate a network connection to servers before any OS is loaded so that the OS images or components can be downloaded over the network. See, “Preboot Execution Environment (PXE) Specification Version 2.1”, by Intel Corporation, September 1999. As illustrated in FIG. 2, ImageDisk/BootDisk (210) is downloaded from Image Server (110) to Client Computer (120) over Network (130) utilizing PXE facilities. ImageDisk/BootDisk (210) contains computer code that initializes operation of Client Computer (120) and provides Execution Environment (220) in Program Memory (230) of Client Computer (120). A preferred embodiment of Execution Environment (220) is Wyse Imaging System (WISard) execution environment. However, Execution Environment (220) can be any preboot execution environment known to those skilled in the art without departing from the scope of the present invention. To briefly describe the operation of network boot and PXE, the booting process of a client computer starts at the ROM BIOS (240) of Client Computer (120) which contains code for recognizing the network interface card (NIC) as an IPL Device (Initial Program Load Device) from which to boot and load an operating system. See, “BIOS Boot Specification”, by Compaq Computer Corporation, Phoenix Technologies Ltd., and Intel Corporation, January 1996. The network card in turn must also be a bootable device such as a PXE-enabled NIC. PXE includes DHCP (Dynamic Host Configuration Protocol) that allows IP address assignment to the NIC at Client Computer (120) so that Client Computer (120) may communicate with Image Server (110) over Network (130) utilizing industry standard TCP/IP network protocol. In addition, PXE supports TFTP (Trivial File Transfer Protocol) of TCP/IP suite for transferring files over Network (130). The network card can also employ any preboot communication protocol known to those skilled in the art such as the IBM RPL (Remote Program Load) without departing from the scope of the present invention. When Client Computer (120) initiates booting, the BIOS Boot code instructs the PXE-enabled NIC to perform PXE operation—DHCP, DHCP-proxy and TFTP transfer—to obtain the initial OS boot code, which in turn connects to a boot server, for example, Image Server (110), to download the initial OS boot code, which can be provided by an image, DiskImage (210), or a proprietary archive, BootDisk (210). When loaded to Program Memory (230) of Client Computer (120), DiskImage/BootDisk (210) code provides Execution Environment (220) such as WISard. For legacy OS support, Execution Environment (220) then traps the pre-OS disk access requests (INT 13 in PC architecture) and redirects them to the PXE-enabled NIC so that the necessary OS files can continued to be downloaded to Client Computer (120). For non-legacy OS support, INT13-interception is not required since bootstrap may contain all intelligence to perform preboot functions. That is, no INT13 related translation is required since the bootstrap contains operating intelligence (such as WISard). In either case, the entire boot process is completely transparent to users on Client Computer (120). FIG. 3 illustrates downloading and operation of a language agent at a client computer according to the present invention. As shown in FIG. 3, the first image file downloaded to Client Computer (120), designated as Root.i2u (310), contains code for Client Language Agent (122). All subsequent image files downloaded are processed by Client Language Agent (122). A key component of Client Language Agent (122) is a preboot execution language interpreter, which is a general purpose interpreter which can interpret and execute specifications for preboot computing tasks in accordance with the supported syntax and semantics. The preboot execution language interpreter of Client Language Agent (122) of the present invention, thus allows processing of any computing task at Client Computer (120) by transmitting to Client Computer (120) files which contain specifications for preboot computing tasks. Since a computer language is by nature symbolic, abstract entity, this process is better understood when viewed from a symbolic, or more accurately, a logical perspective. FIG. 4 illustrates a logical view of downloading a language agent according to the present invention. Any file or image is an Endpoint (410), which in the present case is Root.i2u (310). A more complete definition and description of an Endpoint is given below. As shown in FIG. 4, Root.i2u (310) provides code that operates as Client Language Agent (122) in WISard Execution Environment (220). FIG. 5 illustrates downloading a specification file according to the present invention. As shown in FIG. 5, a specification file, designated as Rule.i2d (510) is downloaded from Image Server (110), and processed by Client Language Agent (122). The preboot execution language interpreter of Client Language Agent (122) interprets the specifications for executing computing tasks contained in Rule.i2d (510) and performs the specified computing tasks. Rule.i2d (510) can also contain instructions to download further specification files. FIG. 6 illustrates downloading a series of specification files according to the present invention. As shown in FIG. 6, a series of specification files, designated as Rule0.i2d (610), Rule1.i2d (612), Rule2.i2d (614), and RuleN.i2d (616), are downloaded in succession by chain download instructions contained in the files. Since this process can be continued for an arbitrary number of times, any computing task can be specified and performed in the preboot execution environment. The computing tasks can be those for general imaging, platform imaging, remote imaging, remote booting, preboot computer diagnostics, and computer preparations (“prepping”) such as formatting and partitioning the hard disks on Client Computer (120), without departing from the scope of the present invention. The veracity of these propositions, remarkable they may be, would become evident when the syntax of the preboot execution and specification language of the present invention is described. First, definitions of the terms are given. (1) “Method” is the means to provide data through an endpoint. Some examples of methods are stream/, fswyse/, fsfat/, or any other WISard supported method. (2) “Location” provides for a complete description of a physical interface; this is where data is actually located. Examples of location are: ide0-0/, ide0-1/, ide1-0, and ide1-1/ for IDE hard disk drives; nand/ and nor/ for flash memory devices; or any WISard supported location or device. (3) “Reference” is used as an operator to define a sub-part of a method/location/definition. An example of a reference name is a file on a device through a file-system, e.g., fsfat/ide1-0/file, or any WISard supported reference. (4) “Endpoint” is a Location of a data image, Method of retrieval, and Reference name. Endpoints are generally of the form: Method/Location/Reference. (5) “Pipe” is a pair of well-defined endpoints comprising source and destination information from which to read and write data. Given the foregoing definitions, the syntax of the preboot execution specification language of the present invention is as follows. First, the preboot execution specification language of the present invention provides an instance copy language where a left-side (LHS) is copied to the right hand-side (RHS). It operates in a manner similar to a familiar MS-DOS ‘copy’ operation: “LangPXE f1 f2”, where the instance f1 is copied and a new instance f2 is created by the language agent LangPXE. Note that f1 and f2 may also contain any additional drive or path information formally utilized by the file-system rules. Second, the language of the present invention provides a means of device copying describing a physical path to the instance: “LangpXE physical-path/f1 physical-path/f1”. An example of this type of copying is copying entire content of one hard disk drive and place it onto another hard disk. For instance, when “LangPXE ide0-0/f1 ide0-1/f2” is carried out, a duplicate of ide0-0 drive is created on ide0-1 drive. Third, the language of the present invention provides a means of copying or applying an endpoint to the instance: “LangPXE Method 1/Location 1/Reference 1 Method2/Location2/Reference2.” For example, “LangPXE stream/ide1-0/disk.raw tftp/disk.raw” would copy disk ide1-0 to file disk.raw over a network using TFTP. Fourth, the language of the present invention provides a means of describing a Transport for the purpose of executing its described copy operations. In other words, the Transport contains instructions for executing copy operations. A Transport is also called an Archive in the present invention. Also, it is said that the copy operations are “encapsulated” in the Transport or Archive. For example, “LangPXE stream/ide1-0/disk.raw archive/rule.i2d tftp/disk.raw” would encapsulate the copy operation “stream/ide1-0/disk.raw tftp/disk.raw” in the archive/rule.i2d file. In general, the form of the syntax for this purpose is: “LangPXE LHS ARCHIVE RHS”. Fifth, the language of the present invention provides a means of describing the extraction (or unpacking) of an archive for the purpose of performing an encapsulated copy operation. For example, “LangPXE archive/rule.i2d” will result in execution of operations encapsulated in archive/rule.i2d. Sixth, the language of the present invention provides a means of defining symbols for LHS, RHS, and ARCHIVE type. For example, “LangPXE f1 definesymbols/” will define symbols specifically defined in the instance represented by f1. Seventh, the language of the present invention provides symbolic or parametric LHS, RHS, and ARCHIVE types. The parametric types are denoted by < > notation. For example, “LangPXE <f1> archive/<T1> <f2>” encapsulates operations “LangePXE <f1> <f2>” into Transport archive/<T1>, where <f1> and <f2> can substitute for any allowable LHS and RHS forms, respectively, and <T1> can be any Transport reference. In other words, <f1>, <T1>, and <f2> are “variables” or “parameters”. <T1> and <f2> can be NULL, i.e., nonexistent. Eighth, the language of the present invention provides de-referencing of LHS. De-reference operation is denoted by ˜ operator. For example, with “LangPXE ˜f1 archive/T1 f2”, archive/T1 created will not contain the instance represented by f1 until archive/T1 is actually executed. Instead, archive/T1 will contain “˜f1 f2”, which specifies “f1 f2” operation when archive/T1 is executed. In contrast, with “LangPXE ˜f1 archive/T1 f2”, archive/T1 created contains “f1 f2” operation, which is executed when archive/T1 is executed. Thus, ˜ operator effects de-referencing. Another way to understand de-referencing is “nesting” of operations at successive phases of operations specified. “f1 f2” runs the specified operation at the level (or phase) of archive/T1 execution. In contrast, “˜f1 f2” runs “f1 f2” operation at the level of execution of one of the tasks specified by execution of archive/T1, that is, one level down or nested from archive/T1. That is, the object represented by f1 is not contained in the archive/T1, but only the reference is specified. When archive/T1 is executed, f1's object is satisfied and the object is copied to f2. Ninth, the language of the present invention provides de-referencing to the Nth degree, that is de-referencing nested to the Nth level. For example, “LangPXE ˜˜f1 archive/T1 f2” will create the instance of f1 only after the second level event specified in the Transport archive/T1 takes place. Tenth, the language of the present invention provides a means of initiating and terminating encapsulation (or encoding) of archives (or transports). “LangPXE ˜encode archive/T1 T2” will result in all subsequently defined LHS to be placed or referenced in T1 to be placed into T2, and “LangPXE ˜encodeoff archive/T1 T2” will terminate the encoding or encapsulation process for T2. Eleventh, the language of the present invention provides a means of referencing other archives from a single archive. “LangPXE archive/t2 archive/t1” will result in archive/t2 called from archive/t1. Twelfth, the language of the present invention provides a means of returning when called from another archive. “LangPXE RETURN archive/t1” will result in returning to the calling archive which called archive/t1. Thirteenth, the language of the present invention provides a means of describing conditional operations. “LangPXE ˜if archive/t2” will result in the evaluation of the next completed pipe description and process all pipes immediately following the evaluation if the process returned success. If however, it returned false, the process would skip all arguments contained in the transport until coming upon the syntax, “LangPXE ˜endif archive/t2.” Finally, the language of the present invention provides a means of encapsulating within an encapsulation, denoted by @ operator. For example, “LangPXE @archive/t2 archive/t1” will encapsulate archive/t2 within archive/t1, so that when archive/t1 is executed one of the tasks performed is execution of archive/t2 archive. Although the language of the present invention is primarily directed to a preboot execution environment, it should also be noted that the language is a general language that can be operated in any execution environment known to those skilled in the art without departing from the scope of the present invention. Now, with the syntax described above, it is possible to specify and execute any preboot computing tasks, including general imaging, platform imaging, remote imaging, remote booting, preboot diagnostics, and preboot prepping. For example, a “pull” operation in imaging, where images are copied by a client from a server, can be simply specified as: “stream/ide1-0/disk.raw ftp/disk.raw”, which will result in making an duplicate copy of ide1-0 disk over a network by using FTP. Furthermore, “Platform.k stream/sec/validate; stream/ide1-0/disk.raw ftp/disk.raw” will perform: (1) validating Platform is of correct type; and (2) in making a duplicate copy of ide1-0 disk over a network by using FTP. Similarly, a simple “push” operation, where images are copied by a server to a client, can be specified as: “ftp/disk.raw stream/ide1-0/disk.raw”. Remote booting can be accomplished in an analogous fashion, since remote booting is simply providing images necessary over a network to boot a client computer. Client or Target specific customization can be accomplished by utilizing the parametric capability of the language of the present invention. For example, “<GET00> <T00><PUT00> ”, when “<GET00>=ValidLHS,” and “<T00>=NULL,” will provide an immediate pull-and-push operation, where the object represented by LHS is written as an object to RHS. This is a pull-and-push operation (Immediate Write). Using the same example, “<GET00>=ValidLHS, and <T00>=archive/validTransport,” will provide any generalized object-pipe operation where object represented by ValidLHS syntax is immediately placed into an encoding named <T00>. This operation is a pull operation (Immediate Read) which, when <T00> is later executed by the language interpreter, will result in a completed copy operation that places the data-object now contained in the transport <T00> to the now valid RHS reference <PUT00>. This secondary operation is a push operation (Transported Write). In contrast to this example, “<GET00> <T00> <PUT00>”, where “<GET00>=˜ValidLHS” and “<T00>=archive/ValidTransport,” will provide any generalized reference-pipe operation, where ValidLHS reference-syntax is placed into an encoding named <T00>, which, when <T00> is later executed by the language interpreter, will result in read from LHS (ValidLHS) and a write to RHS reference <PUT00>. This is a delayed-pull-and-push operation (Delayed Immediate Write). This differs from the first generalized statement when the current executed transport itself has syntax to encode yet another transport by use of the “˜encode” operation. In this example, “<GET00> <T00> <PUT00>” where “<T00>=archive/ValidTransport” and “<GET00>=+ValidLHS,” causes the object read during the encoding process to be placed into the newly created encoding (future transport). This is an Encoded-Immediate-Read operation and will result in a literal object being placed into a transport as did the previously described pull operation encoding above. Note that in all cases shown, the operators delayed when the existence of LHS occurred and where the placement of the eventual object was to be placed (RHS or Transport). The parametric specification and execution capability of the language of the present invention affords one aspect of object-oriented character of the language. For instance, “<method1>/<location1>/disk1.raw <method2>/<location2>/disk2.raw” is a general specification for a pull-and-push operation. Furthermore, the archive that contains this line is an encapsulation of generalized pull-and-push operation. While an encoding specifying “<method 1>/<location 1>/disk 1.raw archive/<T00> <method2>/<location2>/disk2.raw” is a generalized pull operation, placing all drive contents into the transported archive indicated by the symbol <T00>; later executing the archive <T00> will result in a push operation. As illustrated above, the language of the present invention has capability for symbolic translation, that is, denoting parameters with symbols and resolving that an appropriate time. Moreover, the symbol definitions can be placed in a separate file, a symbol file, to translate or resolve the symbols. Another implication of symbolic translation is the ability to modify the encapsulations by replacing symbols with resolved definitions or with yet another symbol or symbols, since a symbol, by definition, can be anything. In another aspect of the invention, the present invention is a system for specifying computing tasks in a preboot execution environment, comprising a language agent with a preboot execution specification generator. As described in the syntax specification above, the language of the present invention is an interpreter of preboot computing task specification as well as a generator of preboot computing task specification. For example, the archives or transports generated by the present language are encapsulated specifications. Therefore, the language of the present invention is also employed by Server Language Agent (112) to generate preboot computing task specifications. The specified computing tasks can be any tasks supportable by the present invention, including, but not limited to, general imaging, platform imaging, remote imaging, remote booting, preboot diagnostics, and preboot prepping. Thus, complex scripts generated by the existing technologies can be reduced to merely a few lines with parametric specifications. Furthermore, by utilizing parameters and symbols, target or client dependent parameters can by specified in encapsulations before even knowing what the target or client machines will be. With symbolic translation and capability to include encapsulations within another encapsulation, the present invention provides a powerful, flexible, generalized method of specifying computing tasks in preboot environment. Therefore, encapsulations can be used provide a generalized specification for any class of computing operations, including, but not limited to, general imaging, platform imaging, remote imaging, remote booting, preboot diagnostics, and preboot prepping. Such operations or tasks can be encapsulated in an encapsulation of the present invention even when the ultimate target destination or client environment is not known at the time of definition or specification. From the foregoing, it is evident that the language of the present invention has at least two behaviors in three distinct phases—that is, the language behaves as a specification generator at the server during task definition phase, and as a specification interpreter and generator during the specification generation and execution phase. In the example discussed above, “<method>/<location>/disk.raw archive/<T00><method2>/disk.raw”, the distinct phases are: a definition phase, where the encoding is defined; a generation phase, where the archive <T00> is generated by pull operation; and an execution phase, where push operation is performed when the archive <T00> is executed. However, there is no reason to limit specification function at the server or during the definition phase. Since the operations described by the present language can be de-referenced or nested to Nth degree by the ˜ operator, execution of an archive can also generate specification by appropriate instructions. In addition, the @ operator allows encapsulating entire archives within an archive. Thus, the language of the present invention exhibits behavior that changes depending on the execution environment. In object-oriented design literature, this type of behavior is called Polymorphic behavior. Therefore, the language of the present invention has polymorphic behavior with respect to the different “Phases” of operation. That is, the present language is a “Polyphase” language. According to another aspect of the invention, the present invention is an encapsulated object-oriented polyphase language for specifying computing tasks in multiple phases of generating and executing preboot execution specification, comprising: a computing task specification generator; and a computing task interpreter, wherein behaviors of generated specification are polymorphic with respect to the multiple phases of generating and executing preboot execution specification. The multiple phases of generating and executing preboot execution specification comprise: a definition phase, wherein computing tasks are defined; a generating phase, wherein specifications for the computing tasks are generated; and an execution phase, wherein the specifications for the computing tasks are executed. FIG. 7 illustrates a conceptual overview of logical operation of an encapsulated object-oriented polyphase language according to the present invention. As shown in FIG. 7, a computing task in a preboot execution environment can be specified as a set of Pipes (710), comprising a pair of Endpoints (720 and 730), where Endpoint (720) as well as Endpoint (730) can be any source or target. A set of Pipes (710) is then executed by Client Language Agent (122) under WISard Execution Environment (220). Because the language of the present invention is a polyphase language, exactly the same language is used for both Client Language Agent (122) and Server Language Agent (112). This means that both Client Language Agent (122) and Server Language Agent (112) can generate encapsulations and interpret (or execute) the encapsulation. Thus, an encapsulation of the present invention can be modified, propagated, multiplied, or otherwise manipulated in any way. For example, an encapsulation can translate symbols and modify itself or create another encapsulation by Server Language Agent (112) or Client Language Agent (122). Client Language Agent (122), while executing an encapsulation, can generate yet another encapsulation that is to be executed at a later time, e.g., when some desired parameters can be ascertained appropriately, such as additional hardware. FIG. 8a to FIG. 8c show example code for generating a polyphase encapsulation according to the present invention; and FIG. 9 illustrates a polyphase encapsulation generated by the example code shown in FIG. 8a to FIG. 8c according to the present invention. FIG. 9 shows a view of the generated encapsulation, which is a binary image file, by using a binary file viewer. The right pane (910) shows an ASCII representation, and the left pane (920) shows a hexadecimal (Hex) representation. The fact that the specification files, or rule encapsulations are binary files—that is, binary images—underscores an important point. It is that the archives, i.e., the rule or specification files, are simply a part of the image set for the overall imaging process. They are downloaded by PXE as if the files are just any OS component files. Thus, the images are self-describing images. In other words, the images contain all instructions necessary to execute or accomplish their purpose, such as installing the images, booting from the images, or executing any function or set of functions specified. Furthermore, the images encapsulate all parametric behaviors resolved during the appropriate levels of execution nesting. Thus, all target customization is encoded in the image files themselves. The image files are encapsulated method-images. Encapsulated imaging is particularly suited for Platform Imaging, which is defined as installing operating system images on a computing device. Examples of Platform Imaging are: installing Windows XP on a PC, installing Windows CE on an embedded computing device, and installing PocketPC on a hand-held device. In general, Platform Imaging is a target computing device dependent operation because what operating system can be installed on a target depends on the type and capabilities of the target hardware. Thus, Platform Imaging can be advantageously accomplished by encapsulated imaging, since all target dependent parameters can be encapsulated in the images themselves. According to one aspect of the invention, the present invention is a system for encapsulated platform imaging, comprising a language agent with an encapsulated language interpreter for executing an encapsulation, wherein the encapsulation contains all instructions and data necessary to install an operating system onto a computing device. Imaging of an entire platform is accomplished through a single, self-describing encapsulation instance by executing or interpreting the self-describing encapsulation by the language agent with an encapsulated language interpreter. For this purpose, the encapsulation can be considered as persistent encapsulation of operating system class. The operating system can be any operating system known to those skilled in the art, including, but not limited to, Windows XP, Windows 2000, Windows NT, Windows Me, Windows 98, Windows CE, PocketPC, various flavors of Unix systems, and Linux, without departing from the scope of the present invention. The computing device can be any computing device known to those skilled in the art, including, but not limited to, a desktop PC, a notebook PC, an embedded computing device, and a hand-held device. It is important to note that, for platform imaging, the operation is not necessarily limited to preboot environments. For example, an update operation of an existing operating system installation need not take place during preboot time. It can be performed while an operating system is up and running. Encapsulated platform imaging of the present invention provides several advantages over existing methods. According to the present invention, only a single encapsulation is required to obtain a desired state on the client device. Since all target dependent information are parameterized and encapsulated, the same class-object definition can be used to accomplish platform imaging for any platform. Moreover, as described above, the language agent for executing an encapsulation itself can be a part of the method-image encapsulation. Hence, encapsulated platform image is self-contained as well as self-describing, and, therefore, an encapsulation is complete by itself to accomplish platform imaging. No programs or codes need to be preserved separate from the images. Furthermore, all supporting or ancillary operations or computing tasks necessary to accomplish platform imaging can also be encapsulated in the encapsulated method-image itself. For example, hardware configuration and capabilities of a target device can be ascertained and compared for validation process. A status or result of one operation or process can be reported to another. Ancillary tasks such as hostname preservation, OS image preservation, and maintaining and configuring BIOS version and CMOS settings can be encapsulated in the same single encapsulation instance, representing the update operation of all of these parameters. According to the present invention, an encapsulation and the language agent with an encapsulated language interpreter can be provided over a logical connection. A logical connection can be any method of providing data known to those skilled in the art, including, but not limited to, a computer readable medium and a network connection without departing from the scope of the present invention. A computer readable medium can be any computer readable medium known to those skilled in the art, including, but not limited to, a diskette, a compact disc, and a flash disk device without departing from the scope of the present invention. Thus, platform imaging can be accomplished through a single encapsulation instance stored on or delivered from a diskette, a compact disc, a flash disk device, or a network connection. In addition, a bootable interface, which is an initial boot facility, can be provided on or over a logical connection. For instance, a diskette or compact disc containing an encapsulation can be a bootable disk or a bootable compact disc. Similarly, a network connection can provide an initial boot facility by a bootable NIC such as a PXE-enable NIC. With a bootable interface provided, a target device can boot from the logical connection, load the language agent with an encapsulated language interpreter, load the rest of the encapsulation, and interpret or execute the encapsulation with the language agent to accomplish the entire platform imaging operation. Thus, the computer readable medium or a network connection endpoint represent a complete, self-contained, self-describing method of platform imaging. Encapsulated platform imaging with encapsulated method-image is simple to define, create, maintain, inventory, and distribute, reducing the complex process of platform imaging to a simple, elegant, and straightforward procedure. It can seen, then, from the foregoing that the language of the present invention provides a more robust, reliable, and accurate execution or performance of specified tasks, as the target specific parameters are resolved only when the parameterized information becomes available at the appropriate phase to discover the pertinent information. The result is a robust, reliable, flexible, and simple method and system for centralized maintenance and management of client devices in a networked enterprise computing environment with a lower total cost of ownership than existing products. The foregoing description of the preferred embodiment of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention not be limited by this detailed description, but by the claims and the equivalents to the claims appended hereto. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates generally to specifying and executing computing tasks in a preboot execution environment, and specifically to generalized imaging utilizing a language agent and encapsulated object oriented preboot execution and specification language. 2. Description of the Related Art Network-based computing has been gaining popularity in recent years as a more desirable approach to managing enterprise computing needs. Ranging from network-managed PCs, network computers, and thin-clients, network-based computing is largely motivated by the need to reduce the cost of providing IT services (known as the Total Cost of Ownership, TCO) in networked computing environments. It is well known in the industry that the most expensive part of providing computing resources to end-users is not the cost of the computing hardware and software but the cost of on-going maintenance and management. See, Thin Client Benefits, Newburn Consulting (2002); Total Cost of Application Ownership, The Tolly Group Whitepaper (1999); TCO Analyst: A White Paper on GartnerGroup's Next Generation Total Cost of Ownership Methodology, GartnerConsulting (1997). According to the well known studies, network-based computing approach dramatically reduces the TCO by centralizing the maintenance and management functions of IT services, thereby reducing the recurring cost of on-going maintenance and management. A key component of network-based computing is Remote Imaging, that is, installing images on client computers from centrally managed image servers. Remote Imaging is also synonymous to or closely related to Remote Image Installation and Remote Device Management. The basic idea is that centralized maintenance and management of client computers is accomplished by installing or delivering operating system or application images from a centrally managed servers. Existing technologies such as Microsoft Remote Installation Service, Symantec Ghost, and Rapport Device Management, all provide a method of remote imaging. For remote imaging of operating system components, remote imaging operation is usually initiated during a preboot phase. In other words, it is desirable to transfer operating system images to the client computer before it boots so that the client computer boots with the newly installed operating system images or components. Clearly, this preboot phase is the most critical aspect of remote imaging, as the client computer will not function properly at all if wrong operating system image or components were delivered. In a network with significant number of client computers or devices, the preboot phase of remote imaging presents special challenges due to numerous types of devices or computers that need to be managed. For example, the types of machines and corresponding images or components must be ascertained during the preboot phase where none of the typical operating system utilities or application tools are available. Ideally, what is needed is a tool that runs at the client computers during preboot because the client machine is the best place to ascertain what hardware it has and what operating system and software it needs. Furthermore, a maximum flexibility would be afforded by a generalized specification language for specifying and executing computing tasks during the preboot phase. Although preboot imaging and operating system installation is a complex process, much of the process can be parameterized at some abstract level. For example, installation of device drivers, often the most challenging part of installation, can be parameterized as: if X device is found, install Y device driver file. Moreover, overall scheme of operation of remote imaging may be quite similar for many types of devices, e.g., downloading bootstrap code, OS kernel, device drivers, system DLLs, etc. Thus, such operation can be parameterized if the unknown parameters are resolved at the client side by the client devices during execution of remote imaging operations. However, no vendor currently provides a generalized specification language for the preboot execution environment. Without a generalized specification language for the preboot execution environment, the specification and management of images and components at the central image server is a highly complex process with many inherent risks. The device type of the clients must be ascertained beforehand, and images and components must be prepared for each device types within which all devices must have identical hardware. Then, the client device type must be verified when the images and components are delivered to the client devices. The complexities and difficulties of this process is mainly attributable to information mismatch—that is, trying to manage at the server side operations which critically depends on information at the client side. Thus, a generalized specification language for the preboot execution environment which runs at the client machines will also greatly simplify the management functions at the central server. Instead of complex scripts and programs to prepare images and components, all that is needed is a simple specification that provides: if x, y, z hardware or configuration is found, perform X, Y, Z tasks. It can be seen, then, there is a need in the field for a system and a method for specifying and executing imaging tasks in a preboot execution environment. | <SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, the present invention addresses the foregoing need by providing a system and method for specifying and executing computing tasks in a preboot execution environment in general, and by providing, in particular, a method and system for generalized imaging utilizing a language agent and encapsulated object oriented preboot execution and specification language. According to one aspect of the invention, the present invention is a system for executing computing tasks in a preboot execution environment, comprising a language agent with a preboot execution language interpreter. The language agent interprets specifications for performing computing tasks in the preboot execution environment, and performs the specified computing tasks. The preboot execution language interpreter can be an object-oriented language interpreter, and the specification can be an encapsulation, encapsulating parameters resolved by the preboot execution language interpreter at execution time. The computing tasks can be those for accomplishing general image installation, platform imaging, remote imaging, remote booting, preboot computer diagnostics, and preboot device management. According to another aspect of the invention, the present invention is a system for specifying computing tasks in a preboot execution environment, comprising a language agent with a preboot execution specification generator. The preboot execution specification generator can be an object-oriented language code generator, and the generated specifications can be encapsulations, encapsulating parameters resolved at execution time. The computing tasks specified can be those for accomplishing general image installation, platform imaging, remote imaging, remote booting, preboot computer diagnostics, and preboot device management. According to yet another aspect of the invention, the present invention is a system for encapsulated platform imaging, comprising a language agent with an encapsulated language interpreter for executing an encapsulation, wherein the encapsulation contains all instructions and data necessary to install an operating system onto a computing device. Imaging of an entire platform is accomplished through a single, self-describing encapsulation instance by executing or interpreting the self-describing encapsulation by the language agent with an encapsulated language interpreter. Encapsulated platform imaging of the present invention provides several advantages over existing methods. With existing technologies, such as Ghost or Rapport, the applications or software programs utilized to accomplish imaging is separate from the program code, as well as from the data or component images necessary for imaging. The intelligence of the application is relied upon to place the component images onto a client to obtain the state desired on the client machine. Thus, entirely different set of program code is required for each different type of platforms; and the applications, the program codes, and the component images must be maintained separately. A set of component images must be preserved along with the corresponding programs that image a particular client device type. In contrast, according to the present invention, only a single encapsulation is required to obtain the same desired state on the client device. Since all target dependent information are parameterized and encapsulated, the same class-object definition can be used to accomplish platform imaging for any platform. Encapsulated platform imaging is a self-contained as well as self-describing method to accomplish platform imaging. It can be seen, then, the present invention provides a more robust, reliable, and accurate execution or performance of specified computing tasks, as the target specific parameters are resolved only when the parameterized information becomes available at the appropriate phase to discover the pertinent information. The result is a robust, reliable, flexible, and simple method and system for centralized maintenance and management of client devices in a networked enterprise computing environment with a lower total cost of ownership than existing products. Other and further objects and advantages of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and drawings. | 20040227 | 20090908 | 20050901 | 60461.0 | 0 | LOUIE, JUE WANG | SYSTEM AND METHOD FOR GENERALIZED IMAGING OR COMPUTING TASKS UTILIZING A LANGUAGE AGENT AND ONE OR MORE SPECIFICATIONS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,787,403 | ACCEPTED | Method for automatically regulating an oscillator | A method for automatically regulating an oscillator is applicable to a low-speed USB interface connecting system and includes the steps of (a) providing a voltage-controlled oscillator in a USB interface for generating a controllable oscillating signal to a USB electronic device; (b) feeding back the controllable oscillating signal to a frequency comparing unit for comparing the controllable oscillating signal with a Keep Alive Strobe signal in the USB interface; (c) inputting an output signal of the frequency comparing unit to a frequency regulating unit for changing the frequency of the controllable oscillating signal according to a signal regulating voltage fed back from the frequency comparing unit; and (d) repeating (b) and (c) to synchronize the controllable oscillating signal with the Keep Alive Strobe signal in the USB interface; so that the USB interface connecting system and the USB electronic device may be quickly synchronized for data transmission at reduced cost. | 1. A method for automatically regulating an oscillator applicable to a low-speed USB interface connecting system, comprising the steps of: (a) providing a voltage-controlled oscillator in a USB interface so that a controllable oscillating signal is generated by said voltage-controlled oscillator to a USB electronic device; (b) feeding back said controllable oscillating signal to a frequency comparing unit which is used to compare said controllable oscillating signal with a Keep Alive Strobe signal in said USB interface in order to find a difference between frequencies of said controllable oscillating signal and said Keep Alive Strobe signal; (c) inputting an output signal of the frequency comparing unit to a frequency regulating unit where the frequency of said controllable oscillating signal is changed according to a signal regulating voltage fed back from said frequency comparing unit; and (d) repeating steps (b) and (c) to synchronize said controllable oscillating signal with said Keep Alive Strobe signal in said USB interface. 2. The method for automatically regulating an oscillator as claimed in claim 1 wherein said frequency comparing unit comprises a micro integrated circuit. 3. The method for automatically regulating an oscillator as claimed in claim 1 wherein said frequency regulating unit comprises a micro integrated circuit. | FIELD OF THE INVENTION The present invention relates to a method for automatically regulating an oscillator, and more particularly to a method for automatically regulating an oscillator in which a Keep Alive Strobe signal in the Universal Serial Bus (USB) interface is utilized to regulate frequency, so that a USB connecting interface and a USB electronic device are synchronized within a very short time to enable data transmission. BACKGROUND OF THE INVENTION The Universal Serial Bus (USB) is one of the most noticeable products in the new generation of connecting interfaces at the end of year 1998, and has quickly become widely known in the market. The USB specification has actually long been established mainly by Intel in 1996. However, most operating systems in the past did not support USB products because of the high cost when they were first introduced into the market, preventing the USB products from being widely accepted by users. Thanks to the introduction of iMAC, which uses USB interface, into the market and the built-in support provided by Windows 98, USB products eventually became the hottest products in the computer field. Compared to the conventional expansion ports or slots USB largely simplifies connection to various kinds of expansion slots. It enables series connection of up to 127 devices to one computer (this is a theoretical value that may be reached depending on the cooperation between a USB hub and a signal cable; current experiments indicate that up to 111 USB devices may be series connected to one computer via the USB connector) and has the further advantages of enabling Hot Attach and Detach as well as plug-and-play. This means a user does not need to worry about the differences between various kinds of connecting ports nor does the user need to remove the external computer casing or wait for normal shutdown to install/unplug a peripheral. The user only needs to connect a new peripheral to an externally accessible, standard USB slot, execute the steps for installing a driver and the new peripheral can immediately operate normally. Theoretically speaking, any device adapted to transmit digital data may be designed to have a USB interface. Thus, a lot of devices, including loudspeakers, keyboards, mice, scanners, printers, digital cameras, etc., may be designed to connect to a computer via a USB interface. That is why the USB interface is so popular. The USB is a standard connecting interface, which allows connection of an external apparatus to a computer without the need of re-allocating and re-planning the whole system, or the need of open the computer case to adjust the finger-tip controlled switch of the interface card. When a new peripheral is connected to a computer via the USB interface the computer will automatically identify the new peripheral and actuate an appropriate driver. The user does not need to change the computer settings. The starting point on the USB interface for connecting a USB device is referred to as the “host”, which is a USB head for controller output. The USB head may be welded to a base plate or located at an external position. Currently, most base plates may support up to 4 USB plugs each. A regular high-speed USB cable must have aluminum foil and polyester shielding to prevent deterioration of signal during transmission via the cable. The cable internally includes four wires, two of which are positive and negative electrodes for electric power, and the other two are positive (D+) and negative (D−) electrodes for signal. It is important for the four wires to evenly fix inside the cable. The advantages of using a 4-wire cable are to reduce and simplify the plug connections and to enable easier control of the product hardware manufacturing costs. When a personal computer (PC) mainframe issues a control signal all the devices and peripherals connected thereto receive the same signal via a root hub. However, after a comparison of the addresses allocated to these devices and peripherals, only one of them would respond to the signal correspondingly. This is somewhat similar to the network architecture. Therefore, it is necessary for a device or a peripheral not only to correctly receive the data sent from the mainframe but also to correctly issue a corresponding signal in response to the mainframe. For this reason a special encoding must be used for the differential data lines, D+ and D−, before sending the signal so as to solve the problems of signal delay and signal error associated with the USB cable. In this aspect the USB adopts a Non-Return to Zero Invert (NRZI) encoding method, which enables synchronous data access even without synchronous clock pulse signals. As a rule of the NRZI encoding data is not converted when a data bit is a “1”; data is converted when the data bit is a “0”. Please refer to FIG. 3, that is an example explaining the NRZI encoding. A very severe problem exists during the encoding in this way. That is, when a plurality of the same “1” signals are repeatedly received the data are not converted for a long period of time and are thus accumulated, resulting in a “jamming” condition, which then causes serious mistakes in the sequence of reading data. Therefore, a bit-stuffing task must be executed during the NRZI encoding. FIGS. 4(a), 4(b), and 4(c) explain the process of NRZI decoding. Please refer to FIG. 4(a). When there are six consecutive “1” bits contained in an original serial data it is necessary to do the bit-stuffing task by stuffing a “0” bit after the sixth “1” bit, as shown in FIG. 4(b). And, in the process of NRZI encoding, data conversion is executed on these six consecutive “1” bits, as shown in FIG. 4(c). Therefore, before data transmission at the sending end the tasks of bit stuffing and NRZI encoding must be executed. On the other hand, before data reception at the receiving end it is necessary to do NRZI decoding first and then proceed with the unBit-stuffing task. The following are some of the features and advantages of the USB: 1. The USB interface unifies the connectors for various kinds of peripherals. All the communication interfaces, printer interfaces, display output, sound input/output devices, and storage devices use the same USB interface specification. The USB interface functions like a universal contact. A user needs only to insert a plug to complete all connections and setup (or whatever else). 2. The USB has the feature of plug-and-play and is able to automatically detect and allocate system resources. Moreover, the USB interface does not require system resources. That is, it is not necessary to arrange additional system resources in order to set up a USB device, such as interrupt request (IRQ), I/O address, and direct memory access (DMA). 3. The USB has the feature of Hot Attach & Detach. That is, a USB device may be plugged to or unplugged from the computer while the operating system is in a started and operating state. It is not necessary for the user to shut down the computer before connecting a USB device thereto. 4. The USB interface version 1.1 has a transmission speed of 12 Mbps that satisfies most user demands. Of course, the high-speed USB interface 2.0 provides an even better transmission rate. 5. One USB interface allows connection of up to 127 peripherals. Since the USB interface uses a 7-bit addressing field, it provides a total of 27=128 usable addresses. After deduction of one address, that is preset by the USB host for a peripheral first connected to the computer, there are still 127 addresses available for use. Therefore, up to 127 USB devices may be connected to a computer via the USB interface. In brief, the overall function of the USB is to simplify the connection between external peripherals and the computer mainframe. With the USB only a single transmission cable is used for series connection of various kinds of peripherals, such as the parallel port for a printer or the serial port for a modem, and the confusing problem of having a large mass of tangled cables and wires behind the mainframe is solved. However, in using the USB system for data transmission, a clock pulse synchronizing system is required between the mainframe and the peripherals to synchronize their signals. In 1932 a concept was developed to use a phase-locked loop (PLL) as a frequency synthesizer. According to this concept, an input reference signal, extracted from a signal received from a remote transmitter, generates a limited oscillating signal, so that the frequency of the oscillating signal changes with the input reference signal. The following are different accuracies that must be met by different USB specifications for different data transmission rates: For high-speed USB specification: 480 MHz+/−0.05% For full-speed USB specification: 12 MHz+/−0.25% For low-speed USB specification: 1.5 MHz+/−1.5% Therefore, each device must be provided with its own clock pulse (frequency) generator, which must meet the above-mentioned accuracy ranges specified for the clock pulse (frequency) signal to enable compatibility of the device with the USB system. Generally, a clock pulse (frequency) signal is generated via a circuit on a chip and has an accuracy range about +/−3%. A well-known way for increasing the signal accuracy is to use additional quartz units. However, the following disadvantages are found in the circuit design with additional quartz units: 1. Expensive: When an external quartz unit is used there must be one or two more connecting pins provided on the chip. Moreover, the quartz unit has a relatively high unit price that disadvantageously increases the cost of the USB device. 2. Bulky: In a chip card the quartz should have limited size, so that the thickness thereof does not exceed 800 micrometers. However, it is impossible to manufacture quartz to meet this predetermined specification. U.S. Pat. No. 6,297,705 discloses the use of a digital controlled oscillator (DCO) to generate an oscillating signal where the frequency is compared using a counter and then coarsely and finely adjusted. The adjusted oscillating signal is then input to the DCO again. These procedures are repeated until the frequency of the oscillating signal is adjusted to synchronize with the USB electronic device. In this manner, the use of expensive quartz units can be avoided. Nevertheless, the disclosure of U.S. Pat. No. 6,297,705 has the following shortcomings: 1. Prolonged Frequency Adjusting Time: The frequency is coarsely and finely adjusted using a whole packet signal instead of the Keep Alive Strobe signal initially generated by the USB system. This results in a prolonged frequency adjusting time. 2. High Cost and Power Consumption: The design provided by U.S. Pat. No. 6,297,705 requires additional computation power, time consumption and higher costs. Basically, the design involves the use of a counter circuit that is comprised of a calibration block and a look-up table. When the frequency of oscillation is not corrected, the value of the signal will begin a start/stop count, which may be repeated over a longer portion of the packet in order to greater resolution in the correction term. This process requires computation power, time consumption and costs more. Because of the above mentioned problems, the inventor developed a method of regulating the frequency using the Keep Alive Strobe signal generated by the USB interface system so that the USB interface connecting system and the USB electronic apparatus may be synchronized within a very short time to enable data transmission. SUMMARY OF THE INVENTION The primary object of the present invention is to provide a method for automatically regulating an oscillator by utilizing the Keep Alive Strobe signal in the USB interface system to regulate the input frequency so that the USB interface connecting system and the USB electronic device may be synchronized within a very short time period to enable data transmission. Another object of the present invention is to provide a method for automatically regulating an oscillator that enables a reduced number of required components, and accordingly, reduced cost through using a low-speed USB interface connecting system. To achieve the above and other objects the method for automatically regulating an oscillator according to the present invention is applicable to a low-speed USB interface connecting system and includes the steps of (a) providing a voltage-controlled oscillator in a USB interface for generating a controllable oscillating signal to a USB electronic device; (b) feeding back the controllable oscillating signal to a frequency comparing unit to compare the controllable, oscillating signal with a Keep Alive Strobe signal in the USB interface; (c) inputting an output signal of the frequency comparing unit to a frequency regulating unit for changing the frequency of the controllable oscillating signal according to a signal regulating voltage fed back from the frequency comparing unit; and (d) repeating (b) and (c) to synchronize the controllable oscillating signal with the Keep Alive Strobe signal in the USB interface so that the USB interface connecting system and the USB electronic device may be quickly synchronized for data transmission at reduced cost. BRIEF DESCRIPTION OF THE DRAWINGS The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein FIG. 1 is a clock pulse pattern for a USB interface connecting system; FIG. 2 is a flowchart showing the method for automatically regulating an oscillator according to the present invention; FIG. 3 is an example explaining the NRZI encoding; and FIGS. 4(a), 4(b), and 4(c) explain the process of NRZI decoding. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Please refer to FIG. 1 that is a clock pulse pattern for a USB interface connecting system. When a USB interface connecting system is in a connected state it will generate a Keep Alive Strobe signal having a width of 1.33 microsecond (μs) at an interval of one millisecond (ms). The system would automatically enter a non-connect state if there were not a response to the Keep Alive Strobe signal within 3 ms. A simple Phase-Locked Loop (PLL) may take advantage of this signal to continuously regulate synchronous signals of a USB. Please refer to FIG. 2 that is a flowchart of the method of the present invention for automatically regulating an oscillator. As shown, the present invention is applicable to a low-speed USB interface connecting system and mainly includes the following steps: (a) Providing a voltage-controlled oscillator 100 in a USB interface so that a controllable oscillating signal is generated by the voltage-controlled oscillator 100 to a USB electronic device; (b) Feeding back the controllable oscillating signal to a frequency comparing unit 200, which is used to compare the controllable oscillating signal with the Keep Alive Strobe signal in the USB interface in order to find the difference between their frequencies; (c) Inputting an output signal of the frequency comparing unit 200 to a frequency regulating unit 300, where the frequency of the controllable oscillating signal is changed according to a signal regulating voltage fed back from the frequency comparing unit 200; and (d) Repeating steps (b) and (c) to synchronize the controllable oscillating signal with the Keep Alive Strobe signal in the USB interface. Wherein, the frequency comparing unit 200 and the frequency regulating unit 300 may be a micro integrated circuit. Through the comparison and regulation operations respectively conducted by the frequency comparing unit 200 and the frequency regulating unit 300 on the frequency of the oscillating signal output by the voltage-controlled oscillator 100, it is possible to achieve the function of automatically regulating the oscillator. It is noted that the present invention is most suitable for use with low-speed peripherals, that is, devices having a data transmission frequency below 1.5 MHz, such as a mouse, joystick, keyboard, or barcode scanner. Since the present invention is particularly designed for use with a low-speed USB interface connecting system, it allows the clock pulse (frequency) accuracy to have an error range of +/−1.5%, which is much wider than the error ranges of +/−0.25% and +/−0.05% for a full-speed and a high-speed USB interface connecting system, respectively. This wide error range of +/−1.5% may be easily met using the PLL circuit with reference to the Keep Alive Strobe signal. Therefore, the present invention not only solves the problems of high cost and large volume in using the quartz units, but also shortens the time needed to adjust the frequency and reduces the high cost associated with the complicated structures that currently exist in the conventional skill. In brief, the present invention enables synchronization of the USB interface connecting system with USB electronic devices within very short time for data transmission at reduced cost. | <SOH> BACKGROUND OF THE INVENTION <EOH>The Universal Serial Bus (USB) is one of the most noticeable products in the new generation of connecting interfaces at the end of year 1998, and has quickly become widely known in the market. The USB specification has actually long been established mainly by Intel in 1996. However, most operating systems in the past did not support USB products because of the high cost when they were first introduced into the market, preventing the USB products from being widely accepted by users. Thanks to the introduction of iMAC, which uses USB interface, into the market and the built-in support provided by Windows 98, USB products eventually became the hottest products in the computer field. Compared to the conventional expansion ports or slots USB largely simplifies connection to various kinds of expansion slots. It enables series connection of up to 127 devices to one computer (this is a theoretical value that may be reached depending on the cooperation between a USB hub and a signal cable; current experiments indicate that up to 111 USB devices may be series connected to one computer via the USB connector) and has the further advantages of enabling Hot Attach and Detach as well as plug-and-play. This means a user does not need to worry about the differences between various kinds of connecting ports nor does the user need to remove the external computer casing or wait for normal shutdown to install/unplug a peripheral. The user only needs to connect a new peripheral to an externally accessible, standard USB slot, execute the steps for installing a driver and the new peripheral can immediately operate normally. Theoretically speaking, any device adapted to transmit digital data may be designed to have a USB interface. Thus, a lot of devices, including loudspeakers, keyboards, mice, scanners, printers, digital cameras, etc., may be designed to connect to a computer via a USB interface. That is why the USB interface is so popular. The USB is a standard connecting interface, which allows connection of an external apparatus to a computer without the need of re-allocating and re-planning the whole system, or the need of open the computer case to adjust the finger-tip controlled switch of the interface card. When a new peripheral is connected to a computer via the USB interface the computer will automatically identify the new peripheral and actuate an appropriate driver. The user does not need to change the computer settings. The starting point on the USB interface for connecting a USB device is referred to as the “host”, which is a USB head for controller output. The USB head may be welded to a base plate or located at an external position. Currently, most base plates may support up to 4 USB plugs each. A regular high-speed USB cable must have aluminum foil and polyester shielding to prevent deterioration of signal during transmission via the cable. The cable internally includes four wires, two of which are positive and negative electrodes for electric power, and the other two are positive (D+) and negative (D−) electrodes for signal. It is important for the four wires to evenly fix inside the cable. The advantages of using a 4-wire cable are to reduce and simplify the plug connections and to enable easier control of the product hardware manufacturing costs. When a personal computer (PC) mainframe issues a control signal all the devices and peripherals connected thereto receive the same signal via a root hub. However, after a comparison of the addresses allocated to these devices and peripherals, only one of them would respond to the signal correspondingly. This is somewhat similar to the network architecture. Therefore, it is necessary for a device or a peripheral not only to correctly receive the data sent from the mainframe but also to correctly issue a corresponding signal in response to the mainframe. For this reason a special encoding must be used for the differential data lines, D+ and D−, before sending the signal so as to solve the problems of signal delay and signal error associated with the USB cable. In this aspect the USB adopts a Non-Return to Zero Invert (NRZI) encoding method, which enables synchronous data access even without synchronous clock pulse signals. As a rule of the NRZI encoding data is not converted when a data bit is a “1”; data is converted when the data bit is a “0”. Please refer to FIG. 3 , that is an example explaining the NRZI encoding. A very severe problem exists during the encoding in this way. That is, when a plurality of the same “1” signals are repeatedly received the data are not converted for a long period of time and are thus accumulated, resulting in a “jamming” condition, which then causes serious mistakes in the sequence of reading data. Therefore, a bit-stuffing task must be executed during the NRZI encoding. FIGS. 4 ( a ), 4 ( b ), and 4 ( c ) explain the process of NRZI decoding. Please refer to FIG. 4 ( a ). When there are six consecutive “1” bits contained in an original serial data it is necessary to do the bit-stuffing task by stuffing a “0” bit after the sixth “1” bit, as shown in FIG. 4 ( b ). And, in the process of NRZI encoding, data conversion is executed on these six consecutive “1” bits, as shown in FIG. 4 ( c ). Therefore, before data transmission at the sending end the tasks of bit stuffing and NRZI encoding must be executed. On the other hand, before data reception at the receiving end it is necessary to do NRZI decoding first and then proceed with the unBit-stuffing task. The following are some of the features and advantages of the USB: 1. The USB interface unifies the connectors for various kinds of peripherals. All the communication interfaces, printer interfaces, display output, sound input/output devices, and storage devices use the same USB interface specification. The USB interface functions like a universal contact. A user needs only to insert a plug to complete all connections and setup (or whatever else). 2. The USB has the feature of plug-and-play and is able to automatically detect and allocate system resources. Moreover, the USB interface does not require system resources. That is, it is not necessary to arrange additional system resources in order to set up a USB device, such as interrupt request (IRQ), I/O address, and direct memory access (DMA). 3. The USB has the feature of Hot Attach & Detach. That is, a USB device may be plugged to or unplugged from the computer while the operating system is in a started and operating state. It is not necessary for the user to shut down the computer before connecting a USB device thereto. 4. The USB interface version 1.1 has a transmission speed of 12 Mbps that satisfies most user demands. Of course, the high-speed USB interface 2.0 provides an even better transmission rate. 5. One USB interface allows connection of up to 127 peripherals. Since the USB interface uses a 7-bit addressing field, it provides a total of 2 7 =128 usable addresses. After deduction of one address, that is preset by the USB host for a peripheral first connected to the computer, there are still 127 addresses available for use. Therefore, up to 127 USB devices may be connected to a computer via the USB interface. In brief, the overall function of the USB is to simplify the connection between external peripherals and the computer mainframe. With the USB only a single transmission cable is used for series connection of various kinds of peripherals, such as the parallel port for a printer or the serial port for a modem, and the confusing problem of having a large mass of tangled cables and wires behind the mainframe is solved. However, in using the USB system for data transmission, a clock pulse synchronizing system is required between the mainframe and the peripherals to synchronize their signals. In 1932 a concept was developed to use a phase-locked loop (PLL) as a frequency synthesizer. According to this concept, an input reference signal, extracted from a signal received from a remote transmitter, generates a limited oscillating signal, so that the frequency of the oscillating signal changes with the input reference signal. The following are different accuracies that must be met by different USB specifications for different data transmission rates: For high-speed USB specification: 480 MHz+/−0.05% For full-speed USB specification: 12 MHz+/−0.25% For low-speed USB specification: 1.5 MHz+/−1.5% Therefore, each device must be provided with its own clock pulse (frequency) generator, which must meet the above-mentioned accuracy ranges specified for the clock pulse (frequency) signal to enable compatibility of the device with the USB system. Generally, a clock pulse (frequency) signal is generated via a circuit on a chip and has an accuracy range about +/−3%. A well-known way for increasing the signal accuracy is to use additional quartz units. However, the following disadvantages are found in the circuit design with additional quartz units: 1. Expensive: When an external quartz unit is used there must be one or two more connecting pins provided on the chip. Moreover, the quartz unit has a relatively high unit price that disadvantageously increases the cost of the USB device. 2. Bulky: In a chip card the quartz should have limited size, so that the thickness thereof does not exceed 800 micrometers. However, it is impossible to manufacture quartz to meet this predetermined specification. U.S. Pat. No. 6,297,705 discloses the use of a digital controlled oscillator (DCO) to generate an oscillating signal where the frequency is compared using a counter and then coarsely and finely adjusted. The adjusted oscillating signal is then input to the DCO again. These procedures are repeated until the frequency of the oscillating signal is adjusted to synchronize with the USB electronic device. In this manner, the use of expensive quartz units can be avoided. Nevertheless, the disclosure of U.S. Pat. No. 6,297,705 has the following shortcomings: 1. Prolonged Frequency Adjusting Time: The frequency is coarsely and finely adjusted using a whole packet signal instead of the Keep Alive Strobe signal initially generated by the USB system. This results in a prolonged frequency adjusting time. 2. High Cost and Power Consumption: The design provided by U.S. Pat. No. 6,297,705 requires additional computation power, time consumption and higher costs. Basically, the design involves the use of a counter circuit that is comprised of a calibration block and a look-up table. When the frequency of oscillation is not corrected, the value of the signal will begin a start/stop count, which may be repeated over a longer portion of the packet in order to greater resolution in the correction term. This process requires computation power, time consumption and costs more. Because of the above mentioned problems, the inventor developed a method of regulating the frequency using the Keep Alive Strobe signal generated by the USB interface system so that the USB interface connecting system and the USB electronic apparatus may be synchronized within a very short time to enable data transmission. | <SOH> SUMMARY OF THE INVENTION <EOH>The primary object of the present invention is to provide a method for automatically regulating an oscillator by utilizing the Keep Alive Strobe signal in the USB interface system to regulate the input frequency so that the USB interface connecting system and the USB electronic device may be synchronized within a very short time period to enable data transmission. Another object of the present invention is to provide a method for automatically regulating an oscillator that enables a reduced number of required components, and accordingly, reduced cost through using a low-speed USB interface connecting system. To achieve the above and other objects the method for automatically regulating an oscillator according to the present invention is applicable to a low-speed USB interface connecting system and includes the steps of (a) providing a voltage-controlled oscillator in a USB interface for generating a controllable oscillating signal to a USB electronic device; (b) feeding back the controllable oscillating signal to a frequency comparing unit to compare the controllable, oscillating signal with a Keep Alive Strobe signal in the USB interface; (c) inputting an output signal of the frequency comparing unit to a frequency regulating unit for changing the frequency of the controllable oscillating signal according to a signal regulating voltage fed back from the frequency comparing unit; and (d) repeating (b) and (c) to synchronize the controllable oscillating signal with the Keep Alive Strobe signal in the USB interface so that the USB interface connecting system and the USB electronic device may be quickly synchronized for data transmission at reduced cost. | 20040224 | 20061024 | 20050825 | 67150.0 | 0 | TRAN, VINCENT HUY | METHOD FOR AUTOMATICALLY REGULATING AN OSCILLATOR | SMALL | 0 | ACCEPTED | 2,004 |
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10,787,538 | ACCEPTED | Extended dynamic resource allocation in packet data transfer | A method for control of packet data transmissions in a TDMA wireless network to provide for additional choices in the allocation of communication channels. The fixed relationship in the timing of the downlink allocation signalling and subsequent uplink transmission is altered for certain classes of mobile station to avoid physical constraints. Examples of variations in USF signalling in GPRS are given. | 1-31. (Canceled). 32. A multiple access communication method for a mobile station, comprising the steps of: receiving an uplink status flag (USF) on a downlink slot; monitoring the downlink slot to detect the USF; and performing transmission on an uplink slot assigned by the USF, wherein if shifted USF operation is not used, then a first downlink slot is monitored to detect a USF for assigning a first uplink slot and if the shifted USF operation is used, then a second downlink slot is monitored to detect both the USF for assigning the first uplink slot and a USF for assigning a second uplink slot. 33. The method according to claim 32, wherein if the USF for assigning the first uplink slot is detected on the second downlink slot then the transmission is performed on the first uplink slot. 34. The method according to claim 33, wherein if the USF for assigning the first uplink slot is detected on the second downlink slot, then the transmission is performed on the first uplink slot and all consecutive uplink slots allocated for uplink transmission. 35. The method according to claim 33, wherein if the USF for assigning the first uplink slot is not detected on the second downlink slot, then the second downlink slot is monitored to detect the USF for assigning the second uplink slot. 36. The method according to claim 35, wherein if the USF for assigning the second uplink slot is detected on the second downlink slot, then the transmission is performed on the second uplink slot. 37. The method according to claim 32, wherein a value of the USF for assigning the first uplink slot is different from a value for assigning the second uplink slot. 38. The method according to claim 32, wherein the transmission is performed on an nth (n being an integer) uplink slot if a USF for assigning the nth uplink slot is detected on an nth downlink slot. 39. The method according to claim 38, wherein the transmission is performed on the nth uplink slot and all consecutive uplink slots allocated for uplink transmission if the USF for assigning the nth uplink slot is detected on the nth downlink slot. 40. The method according to claim 32, wherein eight consecutive uplink slots form an uplink TDMA frame and eight consecutive downlink slots form a downlink TDMA frame. 41. The method according to claim 40, wherein if a USF for assigning an nth (n being an integer) uplink slot is detected on an nth downlink slot of a present downlink TDMA frame, the transmission is performed on the nth uplink slot of a next uplink TDMA frame or consecutive group of uplink TDMA frames. 42. The method according to claim 40, wherein an offset between the uplink TDMA frame and the downlink TDMA frame is three slots or approximately three slots. 43. The method according to claim 32, further comprising the step of performing adjacent cell signal level measurement and preparation for reception prior to re-configuration from transmission to reception. 44. The method according to claim 43, wherein the time needed for performing adjacent cell signal level measurement and preparation for reception is three slots. 45. The method according to claim 43, wherein the time needed for performing adjacent cell signal level measurement and preparation for reception is one slot. 46. The method according to claim 43, wherein the time needed for performing adjacent cell signal level measurement and preparation for reception is one slot and thirty one symbol periods timing advance offset. 47. The method according to claim 32, further comprising the step of: performing adjacent cell signal level measurement and preparation for reception prior to re-configuration from reception to transmission, wherein the time needed for performing adjacent cell signal level measurement and preparation for transmission is one slot. 48. The method according to claim 44, wherein usage of the shifted USF operation is indicated if three slots are allocated for the uplink transmission in the uplink TDMA frame. 49. The method according to claim 45, wherein usage of the shifted USF operation is indicated if five slots are allocated for the uplink transmission in the uplink TDMA frame. 50. The method according to claim 46, wherein usage of the shifted USF operation is indicated if five slots are allocated for the uplink transmission in the uplink TDMA frame. 51. The method according to claim 47, wherein usage of the shifted USF operation is indicated if six slots are allocated for the uplink transmission in the uplink TDMA frame. 52. The method according to claim 48, wherein the indication to use the shifted USF operation is automatic. 53. The method according to claim 49, wherein the indication to use the shifted USF operation is automatic. 54. The method according to claim 50, wherein the indication to use the shifted USF operation is automatic. 55. The method according to claim 51, wherein the indication to use the shifted USF operation is automatic. 56. The method according to claim 32, wherein the number of multi-slot class is any one of multi-slot classes 7, 34, 39 and 45. 57. A mobile station apparatus for multiple access communication, comprising: a reception section that receives an uplink status flag (USF) on a downlink slot; a detection section that monitors the downlink slot to detect the USF; and a transmission section that performs transmission on an uplink slot assigned by the USF, wherein if shifted USF operation is not used, then the detection section monitors a first downlink slot to detect a USF for assigning a first uplink slot and if the shifted USF operation is used, then the detection section monitors a second downlink slot to detect both the USF for assigning the first uplink slot and a USF for assigning a second uplink slot. 58. The apparatus according to claim 57, wherein if the USF for assigning the first uplink slot is detected on the second downlink slot, then the transmission is performed on the first uplink slot. 59. The apparatus according to claim 58, wherein if the USF for assigning the first uplink slot is detected on the second downlink slot, then the transmission is performed on the first uplink slot and all consecutive uplink slots allocated for uplink transmission. 60. The apparatus according to claim 58, wherein if the USF for assigning the first uplink slot is not detected on the second downlink slot, then the second uplink slot is monitored to detect the USF for assigning the second uplink slot. 61. The apparatus according to claim 60, wherein if the USF for assigning the second uplink slot is detected on the second downlink slot, then the transmission is performed on the second uplink slot. 62. The apparatus according to claim 57, wherein a value of the USF for assigning the first uplink slot is different from a value for assigning the second uplink slot. 63. The apparatus according to claim 57, wherein the transmission is performed on an nth (n being an integer) uplink slot if a USF for assigning the nth uplink slot is detected on an nth downlink slot. 64. The apparatus according to claim 63, wherein the transmission is performed on the nth uplink slot and all consecutive uplink slots allocated for uplink transmission if the USF for assigning the nth uplink slot is detected on the nth downlink slot. 65. The apparatus according to claim 57, wherein eight consecutive uplink slots form an uplink TDMA frame and eight consecutive downlink slots form a downlink TDMA frame. 66. The apparatus according to claim 65, wherein if a USF for assigning an nth (n being an integer) uplink slot is detected on an nth downlink slot of a present downlink TDMA frame, the transmission is performed on the nth uplink slot of a next uplink TDMA frame or consecutive group of uplink TDMA frames. 67. The apparatus according to claim 65, wherein an offset between the uplink TDMA frame and the downlink TDMA frame is three slots or approximately three slots. 68. The apparatus according to claim 57, further comprising: a preparation section that prepares for reception prior to reconfiguration from transmission to reception; and a measurement section that performs adjacent cell signal level measurement prior to re-configuration from transmission to reception or prior to re-configuration from reception to transmission. 69. The apparatus according to claim 68, wherein the measurement section performs adjacent cell signal level measurement prior to reconfiguration from transmission to reception and the time needed for performing adjacent cell signal level measurement and preparation for reception is three slots. 70. The apparatus according to claim 68, wherein the measurement section performs adjacent cell signal level measurement prior to reconfiguration from transmission to reception and the time needed for performing adjacent cell signal level measurement and preparation for reception is one slot. 71. The apparatus according to claim 68, wherein the measurement section performs adjacent cell signal level measurement prior to reconfiguration from transmission to reception and the time needed for performing adjacent cell signal level measurement and preparation for reception is one slot and thirty one symbol periods timing advance offset. 72. The apparatus according to claim 68, wherein the measurement section performs adjacent cell signal level measurement prior to reconfiguration from reception to transmission and the time needed for performing adjacent cell signal level measurement and preparation for transmission is one slot. 73. The apparatus according to claim 69, wherein usage of the shifted USF operation is indicated if three slots are allocated for the uplink transmission in the uplink TDMA frame. 74. The apparatus according to claim 70, wherein usage of the shifted USF operation is indicated if five slots are allocated for the uplink transmission in the uplink TDMA frame. 75. The apparatus according to claim 71, wherein usage of the shifted USF operation is indicated if five slots are allocated for the uplink transmission in the uplink TDMA frame. 76. The apparatus according to claim 72, wherein usage of the shifted USF operation is indicated if six slots are allocated for the uplink transmission in the uplink TDMA frame. 77. The apparatus according to claim 73, wherein the indication to use the shifted USF operation is automatic. 78. The apparatus according to claim 74, wherein the indication to use the shifted USF operation is automatic. 79. The apparatus according to claim 75, wherein the indication to use the shifted USF operation is automatic. 80. The apparatus according to claim 76, wherein the indication to use the shifted USF operation is automatic. 81. The apparatus according to claim 57, wherein the number of multi-slot class is any one of multi-slot classes 7, 34, 39 and 45. 82. A multiple access communication system, comprising: a base station apparatus that transmits a uplink status flag (USF) on a downlink slot; and a mobile station apparatus that receives the USF on the downlink slot, monitors the downlink slot to detect the USF and performs transmission on an uplink slot assigned by the USF, wherein if shifted USF operation is not used, then the mobile station apparatus monitors a first downlink slot to detect a USF for assigning a first uplink slot and if the shifted USF operation is used, then the mobile station apparatus monitors a second downlink slot to detect both the USF for assigning the first uplink slot and a USF for assigning a second uplink slot. | BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to multiple access communication systems and in particular it relates to dynamic resource allocation in time division multiple access systems. 2. Description of Related Art In Multiple access wireless systems such as GSM, a number of mobile stations communicate with a network. The allocation of physical communication channels for use by the mobile stations is fixed. A description of the GSM system may be found in The GSM System for Mobile Communications by M. Mouly and M. B. Pautet, published 1992 with the ISBN reference 2-9507190-0-7. With the advent of packet data communications over Time Division Multiple Access (TDMA) systems, more flexibility is required in the allocation of resources and in particular in the use of physical communication channels. For packet data transmissions in General Packet Radio Systems (GPRS) a number of Packet Data CHannels (PDCH) provide the physical communication links. The time division is by frames of 4.615 ms duration and each frame has eight consecutive 0.577 ms slots. A description of the GPRS system may be found in (3GPP TS 43.064 v5.1.1). The slots may be used for uplink or downlink communication. Uplink communication is a transmission from the mobile station for reception by the network to which it is attached. Reception by the mobile station of a transmission from the network is described as downlink. In order to utilise most effectively the available bandwidth, access to channels can be allocated in response to changes in channel conditions, traffic loading, Quality of Service and subscription class. Owing to the continually changing channel conditions and traffic loadings a method for dynamic allocation of the available channels is available. The amounts of time that the mobile station receives downlink or transmits uplink may be varied and slots allocated accordingly. The sequences of slots allocated for reception and transmission, the so-called multislot pattern is usually described in the form RXTY. The allocated receive (R) slots being the number X and the allocated transmit slots (T) the number Y. A number of multislot classes, one through to 45, is defined for GPRS operation and the maximum uplink (Tx) and downlink (Rx) slot allocations are specified for each class. In a GPRS system, access to a shared channel is controlled by means of an Uplink Status Flag (USF) transmitted on the downlink to each communicating mobile station (MS). In GPRS two allocation methods are defined, which differ in the convention about which uplink slots are made available on receipt of a USF. The present invention relates to a particular allocation method, in which an equal number “N” of PDCH's, a “PDCH” representing a pair of uplink and downlink slots corresponding to each other on a 1-1 basis, are allocated for potential use by the MS. The uplink slots available for actual use by a particular mobile station sharing the uplink channel are indicated in the USF. The USF is a data item capable of taking 8 values V0-V7, and allows uplink resources to be allocated amongst up to 8 mobiles where each mobile recognises one of these 8 values as ‘valid’, i.e. conferring exclusive use of resources to that mobile. A particular mobile station may recognise a different USF value on each of the slots assigned to that mobile station. In the case of the extended dynamic allocation method, for example, reception of a valid USF in the slot 2 of the present frame will indicate the actual availability for transmission of transmit slots 2 . . . N in the next TDMA frame or group of frames, where N is the number of allocated PDCHs. Generally for a valid USF received at receiver slot n, transmission takes place in the next transmit frame at transmit slots n, n+1 et seq. to the allocated number of slots (N). For the extended dynamic allocation method as presently defined these allocated slots are always consecutive. The mobile station is not able instantly to switch from a receive condition to a transmit condition or vice versa and the time allocated to these reconfigurations is known as turnaround time. It is also necessary for the mobile station, whilst in packet transfer mode, to perform neighbourhood cell measurements. The mobile station has continuously to monitor all Broadcast Control Channel (BCCH) carriers as indicated by the BA (GPRS) list and the BCCH carrier of the serving cell. A received signal level measurement sample is taken in every TDMA frame, on at least one of the BCCH carriers. (3GPP TS 45.008v5 10.0). The turnaround and measurement times guaranteed by the network for a mobile station depend on the multislot class to which the mobile claims conformance (3GPP TS 45.002v5.9.0 Annex B). The neighbour cell measurements are taken prior to re-configuration from reception to transmission or prior to re-configuration from transmission to reception. A mobile station operating in extended dynamic allocation mode presently must begin uplink transmission in the Tx timeslot corresponding to the Rx timeslot in which the first valid USF is recognised. That is to say that there is a fixed relationship in the timing of the downlink allocation signalling and subsequent uplink transmission. Owing to the physical limitations of single transceiver mobile stations some desirable multislot configurations are not available for use. These restrictions reduce the availability of slots for uplink transmissions thereby reducing the flow of data and the flexibility of response to changing conditions. There is a need therefore to provide a method with which to enable the use of those multislot configurations currently unavailable for Extended Dynamic Allocation. SUMMARY OF THE INVENTION It is an object of this invention to reduce the restrictions affecting extended dynamic allocation with minimal effect on the existing prescript. This may be achieved by altering the fixed relationship in the timing of the downlink allocation signalling and subsequent uplink transmission for certain classes of mobile station. In accordance with the invention there is a method for controlling uplink packet data transmissions and a mobile station operating in accordance with the method as set out in the attached claims. BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the invention will now be described with reference to the accompanying figures in which: FIG. 1 illustrates the GPRS TDMA frame structure showing the numbering convention used for uplink (UL) and downlink (DL) timeslots; FIG. 2 illustrates a prior art 4 slot steady state allocation R1T4; FIG. 3 illustrates a 5 slot steady state allocation R1T5 prohibited in the prior art; FIG. 4 illustrates a 5 slot steady state allocation R1T5 enabled by the method of the present invention; FIG. 5 illustrates a shifted USF applied to a class 7 MS with 3 uplink slots allocated; FIG. 6 illustrates a class 7 MS with 2 uplink slots allocated; FIG. 7 is a flow diagram for the implementation of shifted USF in a mobile station; FIG. 8 illustrates a transition from one uplink slot to five uplink slots for a class 34 MS; and FIG. 9 illustrates a transition from four to five uplink slots for a class 34 MS. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In this embodiment, the invention is applied to a GPRS wireless network operating in accordance with the standards applicable to multislot classes. In FIG. 1 the GPRS TDMA frame structure is illustrated and shows the numbering convention used for uplink (Tx) and downlink (Rx) timeslots. It should be noted that in practice Tx may be advanced relative to Rx due to timing advance (TA), although this is not shown in the illustration. Thus in practice the amount of time between the first Rx and first Tx of a frame may be reduced a fraction of a slot from the illustrated value of 3 slots due to timing advance. Two successive TDMA frames are illustrated with downlink (DL) and uplink (UL) slots identified separately. The slot positions within the first frame are shown by the numerals 0 through to 7 with the transmission and reception slots offset by a margin of three slots. This is in accordance with the convention that that the first transmit frame in a TDMA lags the first receive frame by an offset of 3 (thus ordinary single slot GSM can be regarded as a particular case in which only slot 1 of transmit and receive is used). The remaining figures conform to the illustration of FIG. 1 but the slot numbering has been removed for extra clarity. The shaded slots are those allocated for the particular states and the arrowed inserts indicate the applicable measurement and turnaround intervals. The hashed slots indicate reception of a valid USF and the timeslot in which that USF is received. As mentioned above, constraints are imposed by the need to allow measurement and turnaround slots and the prescript for these in 3GPP TS 45.002 Annex B limits dynamic allocation as shown in table 1. TABLE 1 Maximum Minimum Multislot number of slots number of slots class Rx Tx Sum Tta Ttb Tra Trb 7 3 3 4 3 1 3 1 34 5 5 6 2 1 1 1 39 5 5 6 2 1 1 + to 1 45 6 6 7 1 1 1 to Tta is the time needed for the MS to perform adjacent cell signal level measurement and get ready to transmit. Ttb is the time needed for the MS to get ready to transmit Tra is the time needed for the MS to perform adjacent cell signal level measurement and get ready to receive. Trb is the time needed for the MS to get ready to receive It should be noted that in practice the times Tta and Ttb may be reduced by a fraction of a slot due to timing advance. t0 is 31 symbol periods timing advance offset With reference to FIG. 2, a steady state single downlink and 4 uplink slot allocation for a class 34 mobile station is illustrated. The turnaround and measurement periods for this class are shown in table 1 as Tra, Trb and Ttb each having one slot and Tta having two slots. These periods can be accommodated for this allocation when a valid USF is received in time slot 0. When the allocation of uplink slots extends to five, however, a constraint arises as indicated in the illustration of FIG. 3 which is for a class 34 mobile station with an allocation of one downlink and five uplink slots. The constraint occurs at the position indicated by ‘A’ because no time is allowed for the changeover from transmit to receive (Trb). In the downlink time slot 0 a valid USF is received and the following two slots provide for Tta. In accordance with the invention, for this embodiment the mobile has uplink slots assigned in the usual way, through the use of USF_TN0 . . . USF_TN7 Information Elements in Packet Uplink Assignment and Packet Timeslot Reconfigure messages. The network sends the USF, however, for both first and second assigned timeslots on the downlink PDCH associated with the second assigned timeslot. Considering by way of example a class 34 MS with an assignment of 5 uplink slots (TN0-TN4) as discussed above where the network sends USF_TN0 on timeslot 1 rather than timeslot 0. This arrangement is illustrated in FIG. 4 where it can be seen that slots marked ‘B’ and ‘C’ provide for turnaround times Tra and Trb respectively. An allocation by the network of 4 uplink slots to the MS will be signalled by the sending of USF_TN1 on timeslot 1. The characters of the two signals USF_TN0 and USF_TN1 must differ and must be distinguishable by the mobile station. It is not necessary to add extra information elements to indicate when the Shifted USF mechanism is to be used, as it may be made implicit in the timeslot allocations for the particular multislot class of the mobile station. Therefore no increase in signalling overhead would be required. With reference to FIG. 5, another example of an allocation enabled by implementation of a shifted USF is illustrated in FIG. 5. The application is a class 7 MS with three uplink slots allocated. The USF on downlink slot 1 allocating the 3 uplink slots indicates that the first uplink slot available is uplink slot 0 rather than the usual slot 1. This provides for the Ttb and Tra periods (as required by table 1) and as indicated in FIG. 5 at D and E respectively. The allocation would not previously have been available for want of a sufficient period for Tra. The 2 slot allocation illustrated in FIG. 6 reverts to normal operation i.e. the USF is not shifted. There are no physical constraints in normal allocations for this 2 slot arrangement of FIG. 6 and the standard USF in time slot 1 allocates uplink slots beginning with uplink slot number 1. Alternatively it may be convenient to apply positive signalling of the shift in position of the uplink allocation and an implementation of a shifted USF in a mobile station operating extended dynamic allocation is illustrated in FIG. 7. It should be noted that the indication (2) in FIG. 7 may be explicit (i.e. extra signalling) or implicit (automatic for particular multislot class configuration). With reference to FIG. 7, the mobile station receives at 1 an assignment of uplink resources and USF's from the network. If at 2, an indication to use a shifted USF is detected then, for the first USF, the second downlink slot is monitored (3) otherwise the first downlink slot is monitored (4). In either case, when a valid USF has been received at 5 then uplink transmissions are initiated in the first uplink slot from the mobile station (6). When no valid USF has been received at 5 then the second downlink slot is monitored for a second USF at 7 and if valid (8) then uplink transmissions are initiated in the second uplink slot (9). In the examples illustrated in FIGS. 2 to 6 the allocations are steady state such that the allocations shown are maintained from frame to frame. The invention is not restricted to steady state allocations and may be applied also to control of uplink resources that change from one frame to another. Examples of transitions are illustrated in FIGS. 8 and 9. These figures each represent four consecutive frames but have been split for presentation. FIG. 8 illustrates the transition from one uplink slot allocation to five uplink slots allocation, for a Class 34 mobile. The first (top) two frames show steady state operation with one slot and the next (bottom) two frames show the transitional frames. For this transition the slot location of the USF is changed. FIG. 9 illustrates the transition from four uplink slots to five uplink slots, for a Class 34 mobile. The first two frames show steady state operation with four slots and the next two frames show the transitional frames. For this transition the USF slot location is constant but the value of the USF is changed. In order to implement the invention in GPRS for example a table (Table 2) may be constructed for a Type 1 MS to allow extended dynamic allocation using the principles below: In the case of extended dynamic allocation it is desirable for the MS to be able to “transmit up to its physical slot limit”; specifically, the MS should be able to transmit the maximum number of slots possible according to the limitation of its multislot class, while continuing to receive and decode the USF value on exactly one slot and performing measurements. If it is not possible to define a multislot configuration which permits the MS to “transmit up to its physical slot limit” using Tra, but it would be possible by using Tta, then Tta shall be used. If it is not possible to define a multislot configuration for extended dynamic allocation which permits the MS to “transmit up to its physical slot limit” but it would be possible by using the shifted USF mechanism, then shifted USF shall be used. In this case Tra will be used as first preference, but if this is not possible Tta will be used as second preference. TABLE 2 Tra Tta Applicable Medium shall shall Multislot access mode No of Slots apply apply classes Note Uplink, 1-3 Yes — 1-12, 19-45 Ext. 4 No Yes 33-34, 2 Dynamic 38-39, 43-45 5 Yes — 34, 39 5 5 No Yes 44-45 2, 4 6 No Yes 45 5 Down + up, d + u = 2 − 4 Yes — 1-12, 19-45 Ext. d + u = 5, d > 1 Yes — 8-12, 19-45 Dynamic d = 1, u = 4 No Yes 30-45 2 d + u = 6, d > 1 Yes 30-45 2, 3 d = 1, u = 5 Yes 34, 39 5 d + u = 7, d > 1 No Yes 40-45 2, 4 d = 1, u = 6 No Yes 45 5 Note 1 Normal measurements are not possible (see 3GPP TS 45.008). Note 2 Normal BSIC decoding is not possible (see 3GPP TS 45.008). Note 3 TA offset required for multislot classes 35-39. Note 4 TA offset required for multislot classes 40-45. Note 5 Shifted USF operation shall apply (see 3GPP TS 44.060) | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention This invention relates to multiple access communication systems and in particular it relates to dynamic resource allocation in time division multiple access systems. 2. Description of Related Art In Multiple access wireless systems such as GSM, a number of mobile stations communicate with a network. The allocation of physical communication channels for use by the mobile stations is fixed. A description of the GSM system may be found in The GSM System for Mobile Communications by M. Mouly and M. B. Pautet, published 1992 with the ISBN reference 2-9507190-0-7. With the advent of packet data communications over Time Division Multiple Access (TDMA) systems, more flexibility is required in the allocation of resources and in particular in the use of physical communication channels. For packet data transmissions in General Packet Radio Systems (GPRS) a number of Packet Data CHannels (PDCH) provide the physical communication links. The time division is by frames of 4.615 ms duration and each frame has eight consecutive 0.577 ms slots. A description of the GPRS system may be found in (3GPP TS 43.064 v5.1.1). The slots may be used for uplink or downlink communication. Uplink communication is a transmission from the mobile station for reception by the network to which it is attached. Reception by the mobile station of a transmission from the network is described as downlink. In order to utilise most effectively the available bandwidth, access to channels can be allocated in response to changes in channel conditions, traffic loading, Quality of Service and subscription class. Owing to the continually changing channel conditions and traffic loadings a method for dynamic allocation of the available channels is available. The amounts of time that the mobile station receives downlink or transmits uplink may be varied and slots allocated accordingly. The sequences of slots allocated for reception and transmission, the so-called multislot pattern is usually described in the form RXTY. The allocated receive (R) slots being the number X and the allocated transmit slots (T) the number Y. A number of multislot classes, one through to 45, is defined for GPRS operation and the maximum uplink (Tx) and downlink (Rx) slot allocations are specified for each class. In a GPRS system, access to a shared channel is controlled by means of an Uplink Status Flag (USF) transmitted on the downlink to each communicating mobile station (MS). In GPRS two allocation methods are defined, which differ in the convention about which uplink slots are made available on receipt of a USF. The present invention relates to a particular allocation method, in which an equal number “N” of PDCH's, a “PDCH” representing a pair of uplink and downlink slots corresponding to each other on a 1-1 basis, are allocated for potential use by the MS. The uplink slots available for actual use by a particular mobile station sharing the uplink channel are indicated in the USF. The USF is a data item capable of taking 8 values V0-V7, and allows uplink resources to be allocated amongst up to 8 mobiles where each mobile recognises one of these 8 values as ‘valid’, i.e. conferring exclusive use of resources to that mobile. A particular mobile station may recognise a different USF value on each of the slots assigned to that mobile station. In the case of the extended dynamic allocation method, for example, reception of a valid USF in the slot 2 of the present frame will indicate the actual availability for transmission of transmit slots 2 . . . N in the next TDMA frame or group of frames, where N is the number of allocated PDCHs. Generally for a valid USF received at receiver slot n, transmission takes place in the next transmit frame at transmit slots n, n+1 et seq. to the allocated number of slots (N). For the extended dynamic allocation method as presently defined these allocated slots are always consecutive. The mobile station is not able instantly to switch from a receive condition to a transmit condition or vice versa and the time allocated to these reconfigurations is known as turnaround time. It is also necessary for the mobile station, whilst in packet transfer mode, to perform neighbourhood cell measurements. The mobile station has continuously to monitor all Broadcast Control Channel (BCCH) carriers as indicated by the BA (GPRS) list and the BCCH carrier of the serving cell. A received signal level measurement sample is taken in every TDMA frame, on at least one of the BCCH carriers. (3GPP TS 45.008v5 10.0). The turnaround and measurement times guaranteed by the network for a mobile station depend on the multislot class to which the mobile claims conformance (3GPP TS 45.002v5.9.0 Annex B). The neighbour cell measurements are taken prior to re-configuration from reception to transmission or prior to re-configuration from transmission to reception. A mobile station operating in extended dynamic allocation mode presently must begin uplink transmission in the Tx timeslot corresponding to the Rx timeslot in which the first valid USF is recognised. That is to say that there is a fixed relationship in the timing of the downlink allocation signalling and subsequent uplink transmission. Owing to the physical limitations of single transceiver mobile stations some desirable multislot configurations are not available for use. These restrictions reduce the availability of slots for uplink transmissions thereby reducing the flow of data and the flexibility of response to changing conditions. There is a need therefore to provide a method with which to enable the use of those multislot configurations currently unavailable for Extended Dynamic Allocation. | <SOH> SUMMARY OF THE INVENTION <EOH>It is an object of this invention to reduce the restrictions affecting extended dynamic allocation with minimal effect on the existing prescript. This may be achieved by altering the fixed relationship in the timing of the downlink allocation signalling and subsequent uplink transmission for certain classes of mobile station. In accordance with the invention there is a method for controlling uplink packet data transmissions and a mobile station operating in accordance with the method as set out in the attached claims. | 20040227 | 20051004 | 20050106 | 73775.0 | 31 | FERRIS, DERRICK W | EXTENDED DYNAMIC RESOURCE ALLOCATION IN PACKET DATA TRANSFER | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,787,544 | ACCEPTED | Channel adaptation synchronized to periodically varying channel | A method of operating in a network (e.g., a power line communication network) in which a plurality of stations communicate over a shared medium (e.g., an AC power line) having a periodically varying channel. The method includes determining a plurality of channel adaptations (e.g., tone maps) for communication between a pair of stations, and assigning a different one of the plurality of channel adaptations to each of a plurality of phase regions of the periodically varying channel. | 1. A method of operating in a network in which a plurality of stations communicate over a shared medium having a periodically varying channel, comprising determining a plurality of channel adaptations for communication between a pair of stations; assigning a different one of the plurality of channel adaptations to each of a plurality of phase regions of the periodically varying channel. 2. The method of claim 1 wherein the channel adaptations for a particular phase region are adapted to the channel in that phase region. 3. The method of claim 2 wherein the network is a power line communication network, the shared medium is an AC power line, and the channel characteristics vary with the phase of the AC line cycle. 4. A method of operating in a network in which a plurality of stations communicate over a shared medium having a periodically varying channel, comprising synchronizing channel adaptation to the periodically varying channel. 5. The method of claim 4 wherein the network is a power line communication network, the shared medium is an AC power line, and the channel characteristics vary with the phase of the AC line cycle. 6. A method of operating in a power line communication network in which a plurality of stations communicate over an AC power line in which the channel characteristics vary with the phase of the AC line cycle, comprising synchronizing channel adaptation to the phase of the AC line cycle. 7. The method of claim 1, 4 or 6 where channel adaptation is substantially unique between any pair of transmitter and receiver. 8. The method of claim 6 wherein each station has a channel adaptation facility that interacts with the channel facility at other stations. 9. The method of claims 1 or 4 wherein each station has a channel adaptation facility that interacts with the channel facility at other stations. 10. The method of claim 8 wherein the channel adaptation facility comprises a tone map generator for generating a tone map. 11. The method of claim 9 wherein the channel adaptation facility comprises a tone map generator for generating a tone map. 12. The method of claim 10 wherein the channel adaptation facility comprises an indication of the start of the AC line cycle. 13. The method of claim 10 wherein the stations exchange tone maps. 14. The method of claim 10 wherein the tone map generator has the capability to generate multiple tone maps, with different tone maps being assigned to different phases regions of the AC line cycle. 15. The method of claim 14 wherein different tone maps are assigned to different regions of each half cycle of the AC line cycle, with each half cycle of the AC line cycle being treated as equivalent to the other half cycle for the purpose of channel adaptation. 16. The method of claim 14 wherein the AC line cycle is divided into a plurality of substantially equal size phase regions, to which a different tone map may be assigned. 17. The method of claim 16 wherein some of the substantially equal size phase regions are assigned the same tone map. 18. The method of claim 15 wherein the AC line cycle is divided into a plurality of substantially equal size phase regions, to which a different tone map may be assigned. 19. The method of claim 18 wherein some of the substantially equal size phase regions are assigned the same tone map. 20. The method of claim 10 wherein associated with each tone map is an indication of the tolerance of that tone map for use outside its boundaries. 21. The method of claim 11 wherein associated with each tone map is an indication of the tolerance of that tone map for use outside its boundaries. 22. The method of claim 12 wherein the indication of the start of an AC line cycle comprises recognition of an AC line cycle zero crossing. 23. The method of claim 12 wherein the indication of the start of an AC line cycle comprises recognition of an AC line cycle zero crossing followed by a rising signal. 24. The method of claim 12 wherein the indication of the start of an AC line cycle comprises recognition of an AC line cycle zero crossing followed by a falling signal. 25. The method of claim 12 wherein the indication of the start of an AC line cycle comprises recognition of a repeating feature in the AC line signal. 26. The method of claim 25 wherein the repeating feature in the AC line signal comprises one or more of the following: a zero crossing, a peak in AC power amplitude, a peak or a minimum in noise amplitude. 27. The method of claim 6 wherein time stamps are transmitted between stations to aid synchronization of channel adaptation to the AC line cycle. 28. The method of claim 4 wherein time stamps are transmitted between stations to aid synchronization of channel adaptation. 29. The method of claim 6 wherein the phase of the AC line cycle at a receiving station is offset from the AC line cycle at a transmitting station, and information relating to the phase offset is provided to the transmitting station so that the channel adaptation used by the transmitting station is synchronized to the AC line cycle at the receiving station. 30. The method of claim 29 wherein the information relating to the phase offset comprises a zero crossing offset between the receiving and transmitting stations. 31. The method of claim 30 wherein the receiving station determines the zero crossing offset, and transmits it to the transmitting station. 32. The method of claim 31 wherein the transmitting station determines the zero crossing offset. 33. The method of claim 22 wherein one station in the network tracks the AC line cycle zero crossing and transmits information on the time of the zero crossing to a plurality of stations on the network, and wherein the plurality of stations use the time of the zero crossing at the one station as their own local AC line cycle zero crossing. 34. The method of claim 22 wherein the AC line cycle zero crossing is derived using virtual tracking, wherein a station uses its local clock along with knowledge of the AC line cycle frequency to track a virtual zero crossing. 35. The method of claim 14 wherein the number of tone map regions, boundaries of each region, and the tone map for each region are determined based on periodically varying channel attenuation characteristics. 36. The method of claim 14 wherein the number of tone map regions, boundaries of each region, and the tone map for each region are determined based on periodically varying local noise characteristics. 37. The method of claim 14 wherein data is transmitted in packets that include at least one header and one payload, and wherein the tone map boundaries and length of the packets are configured so that the payload of most packets is transmitted within one phase region so that the payload does not cross a boundary between tone maps. 38. The method of claim 14 wherein data is transmitted in packets that include at least one header and one payload, and wherein the tone map boundaries and length of the packets are configured so that the payload of at least some packets is transmitted in two adjoining phase regions, so that a first portion of the payload is transmitted using one tone map and a second portion of the payload is transmitted using a second tone map. | TECHNICAL FIELD This invention relates to high-speed communication using AC power lines. BACKGROUND Communication systems are designed to reliably transfer information using the underlying physical medium. Well-known communication systems like Ethernet use special wiring (e.g., Cat 5 cable) for exchanging information. Such systems, by design, allow all connected stations to exchange data at a fixed data rate. With the increasing need for ubiquitous exchange of information, a new class of no-new-wire systems has emerged. Such systems use existing infrastructure to exchange information. Power line communication systems are one example of such systems. Power line communication systems use existing AC wiring to exchange information. Owing to their being designed for much lower frequency transmissions, AC wiring provides varying channel characteristics at the higher frequencies used for data transmission (e.g., depending on the wiring used and the actual layout). To maximize the data rate between various links, stations need to adjust their transmission parameters dynamically in both time and frequency. This process is called channel adaptation. Channel adaptation results in a set of transmission parameters (referred to as tone maps in this document) that can be used on each link. Tone maps include such parameters as the frequencies used, their modulation, and the forward error correction (FEC) used. In high-speed power line communication systems, good channel adaptation is critical to providing high data rates on all links. SUMMARY We have discovered that higher data rates can be achieved in power line communication systems by taking into account the fact that the noise and/or the frequency response of the power line channel between any pair of stations depends on the AC line cycle phase. Power line communication systems share the power line medium with various appliances that draw electric power from the power supply grid. These devices are some of the major sources of noise that affect the characteristics of power line channels. Several types of such devices generate noise that varies with the AC line cycle phase and the carrier frequencies. FIG. 1 shows an example wherein the noise around the zero crossing on the AC line cycle is lower by comparison to the noise at the peaks of the AC cycle. Devices like triac-controlled dimmers turn on and off during each AC line cycle. These not only generate impulse noise but also change the channel frequency response. Further, several devices that use AC motors (e.g., vacuum cleaners, drills, etc.) generate noise that is also a function of the phase of the line cycle. The net effect is a time varying channel whose noise characteristics and frequency response depend on the AC line cycle phase. In general the invention features a method of operating in a network in which a plurality of stations communicate over a shared medium having a periodically varying channel. The method includes determining a plurality of channel adaptations for communication between a pair of stations, and assigning a different one of the plurality of channel adaptations to each of a plurality of phase regions of the periodically varying channel. In preferred implementations, one or more of the following features may be incorporated. The channel adaptations for a particular phase region may be adapted to the channel in that phase region. The network may be a power line communication network, the shared medium may be an AC power line (inside or outside a building and low, medium, or high voltage), and the channel characteristics may vary with the phase of the AC line cycle. Channel adaptation may be synchronized to the periodically varying channel. Channel adaptation may be substantially unique between any pair of transmitter and receiver. Each station may have a channel adaptation facility that interacts with the channel facility at other stations. The channel adaptation facility may include a tone map generator for generating a tone map. The channel adaptation facility may include an indication of the start of the AC line cycle. The stations may exchange tone maps. The tone map generator may have the capability to generate multiple tone maps, with different tone maps being assigned to different phases regions of the AC line cycle. Different tone maps may be assigned to different regions of each half cycle of the AC line cycle, with each half cycle of the AC line cycle being treated as equivalent to the other half cycle for the purpose of channel adaptation. The AC line cycle may be divided into a plurality of substantially equal size phase regions, to which a different tone map may be assigned. Some of the substantially equal size phase regions may be assigned the same tone map. Associated with each tone map may be an indication of the tolerance of that tone map for use outside its boundaries. The indication of the start of an AC line cycle may include recognition of an AC line cycle zero crossing. The indication of the start of an AC line cycle may include recognition of an AC line cycle zero crossing followed by a rising signal. The indication of the start of an AC line cycle may include recognition of an AC line cycle zero crossing followed by a falling signal. The indication of the start of an AC line cycle may include recognition of a repeating feature in the AC line signal. The repeating feature in the AC line signal may include one or more of the following: a zero crossing, a peak in AC power amplitude, a peak or a minimum in noise amplitude. Time stamps may be transmitted between stations to aid synchronization of channel adaptation to the AC line cycle. The phase of the AC line cycle at a receiving station may be offset from the AC line cycle at a transmitting station, and information relating to the phase offset may be provided to the transmitting station so that the channel adaptation used by the transmitting station is synchronized to the AC line cycle at the receiving station. The information relating to the phase offset may include a zero crossing offset between the receiving and transmitting stations. The receiving station may determine the zero crossing offset, and transmit it to the transmitting station. The transmitting station may determine the zero crossing offset. One station in the network may track the AC line cycle zero crossing and transmit information on the time of the zero crossing to a plurality of stations on the network, and the plurality of stations may use the time of the zero crossing at the one station as their own local AC line cycle zero crossing. The AC line cycle zero crossing may be derived using virtual tracking, wherein a station uses its local clock along with knowledge of the AC line cycle frequency to track a virtual zero crossing. The number of tone map regions, boundaries of each region, and the tone map for each region may be determined based on periodically varying channel attenuation characteristics or on periodically varying local noise characteristics. If data is transmitted in packets that include at least one header and one payload, the tone map boundaries and length of the packets may be configured so that the payload of most packets is transmitted within one phase region so that a payload does not cross a boundary between tone maps. Or the tone map boundaries and length of the packets may be configured so that the payload of at least some packets is transmitted in two adjoining phase regions, so that a first portion of the payload is transmitted using one tone map and a second portion of the payload is transmitted using a second tone map. Among the many advantages of the invention (some of which may be achieved only in some of its implementations) are the following. It enables stations to operate reliability and at higher data rates under various power line environments. It provides a channel adaptation mechanism that can be used in power line communication systems as well as other media that are affected by periodically varying channel impairments. It can provide a higher level of guaranteed quality of service (QoS). DESCRIPTION OF DRAWINGS FIG. 1 shows an example of the variation in noise with AC line cycle phase. FIG. 2 is a schematic of a power line network configuration. FIG. 3 is a block diagram of the configuration of a station on the power line network. FIG. 4 shows the format of a packet sent over the network. FIG. 5 shows an implementation in which a different tone maps may be assigned to each of five different phase regions of the AC line cycle. FIG. 6 shows an implementation in which a different tone map may be assigned to each of three different phase regions of each half period of the AC line cycle. FIG. 7 shows an implementation in which a different tone map may be assigned to each of five equal-size phase regions of each half period of the AC line cycle. FIG. 8 shows an example in which the phase of the AC line cycle is offset between the transmitting and receiving stations. FIG. 9 illustrates the use of transmitter zero cross time stamps to compute the phase offset between stations. FIG. 10 is a block diagram of a synchronizer zero crossing tracking circuit that can be used in some implementations. FIG. 11 shows the MPDU format. FIG. 12 shows an example where MPDU boundaries matching tone map boundaries. FIG. 13 shows an example where MPDU boundaries cross tone map boundaries. DETAILED DESCRIPTION There are a great many possible implementations of the invention, too many to describe herein. Some possible implementations that are presently preferred are described below. It cannot be emphasized too strongly, however, that these are descriptions of implementations of the invention, and not descriptions of the invention, which is not limited to the detailed implementations described in this section but is described in broader terms in the claims. As shown in FIG. 2, the network configuration may include a plurality of stations, S1 to Sn, communicating over power line medium M. Because of the previously discussed channel variations between different locations on a power line network, medium M is unique between any pair of stations. Furthermore, the medium characteristics (which include attenuation, noise etc.,) show a periodic behavior. Each station Si has a channel adaptation function Ai, that interacts with channel adaptation function at other stations to determine communication parameters that are referred to as tone maps. FIG. 3 shows a typical station configuration. Each station S includes a channel adaptation function A, which includes a local clock, tone map generator, medium period start indicator (MPSI) and medium period start synchronization (MPSS). The tone map generator provides the tone maps that are used at various phase regions of the AC cycle. Each tone map specifies parameters including the set of carriers that are to be used, their modulation, and the forward error correction coding to be used. The local clock is a free running clock operating at a certain frequency. It is used as a time reference at each station. The medium period start indicator (MPSI) provides a reference for the start of the medium period for channel adaptation purposes. The medium period start synchronizer (MPSS) is used in implementations in which the MPSI of the transmitter and the MPSI of the receiver are offset from each other. The MPSS enables the tone map boundaries to be properly interpreted by the transmitter and the receiver. Stations exchange structured protocol entities called packets, the format of which is shown in FIG. 4. The packet format allows for the exchange of tone maps, various fields required for medium period start synchronization (which can vary with the particular implementation), and regular data. Various implementations of the tone map generator are possible. In general terms, the tone map generator uses knowledge of channel characteristics and the variation of those characteristics with the phase of the AC line cycle to derive multiple tone maps, which are assigned to different phase regions. The tone map generator uses the channel characteristics and their variation of those characteristics with the phase of the AC line cycle to determine the number of tone maps regions and the boundaries for each tone map region. Tone Map generator also generates tone maps for each of the tone map regions. The channel characteristics used by the tone map generator can include channel attenuation characteristics (or equivalently, the channel impulse response). The channel characteristics used by the tone map generator can also include local noise characteristics. In one implementation, the receiver generates multiple tone maps that can be used in various phase regions of each AC line cycle. FIG. 5 shows an example of such an implementation. In this example, the medium period start indicator (MPSI) tracks the rising edge of the AC zero crossing, and the channel estimation process produces five tone maps, one for each of five phase regions of the AC line cycle. ToneMap-1 is valid in regions (0, t1). ToneMap-2 is valid in regions (t1, t2). ToneMap-3 is valid in regions (t2, t3). ToneMap-4 is valid in region (t3, t4). ToneMap-5 is valid in region (t4, t5). The number of tone maps and their boundaries can be varied enormously from what is shown in FIG. 5. Another implementation allows the receiver to generate multiple tone maps that can be used in various phase regions of each AC half line cycle. But in this implementation; both the positive and negative halves of the AC line cycle are treated as equivalent. The two halves of the line cycle are very often substantially identical (except for being of opposite phase) in most PLC networks. FIG. 6 shows an example of the tone maps used in this implementation. The MPSI tracks the zero crossing of the AC line cycle, and the channel estimation process produces three tone maps. ToneMap-1 is valid in regions (0, t1) and (t3, t3+t1). ToneMap-2 is valid in regions (t1, t2) and (t3+t1, t3+t2). ToneMap-3 is valid in regions (t2, t3) and (t3+t2, t3+t3). As with the first implementation example, the number of tone maps and their boundaries can be varied enormously from what is shown in FIG. 6. Another implementation divides the AC line cycle into a fixed number of equal size phase regions. The channel adaptation process in this case results in tone maps for each of the equal size regions. It may turn out, that the same tone map is used in more than one of the regions. This approach can also use either full line cycle (e.g., FIG. 5) or half line cycle (e.g., FIG. 6) repetition of tone maps. FIG. 7 shows an example where each half line cycle is divided into five phase regions, and the channel adaptation process produces tone maps for each of the five regions. Depending on the channel conditions, it is possible that the same tone map is used in multiple regions. For example, ToneMap-1 and ToneMap-2 might be the same. In this example, the MPSI tracks the zero crossings of the AC line cycle. In all the above implementations, the tone maps generated may contain a tolerance for their boundaries. For example, a tone map may have a 100 μsec tolerance, which indicates that the tone map may be used up to a maximum of 100 μsec away from the actual boundary. Alternatively, a tone map may have a zero tolerance, indicating that the tone map may not be used beyond the boundaries provided. Another approach is to have tone maps boundaries overlap to indicate the tolerance. The transmitting station should ensure that proper tone maps are used at various phases of the AC line cycle. Several approaches can be used by the transmitter to maintain tone map boundaries. Some implementations that are considered preferred are presented below. These implementations can be used in packet-oriented networks, where MAC Protocol Data Units (MPDUs) are used to exchange data between stations. FIG. 11 shows the MPDU format. MPDU contains header and payload fields. The header field contains information on MPDU transmission duration and tone map used for transmitting the payload fields. The payload field contains the data that is being exchanged. One preferred implementation is to align the MPDU payload boundaries so that they do not cross tone map boundaries. FIG. 12 shows an example with two tone map boundaries within a AC half line cycle. In this case, the length of MPDU-1 is chosen so that the payload duration does not cross the tone map boundary-I. A similar procedure has to be used at the tone map boundary-II. Another approach is to allow for change of tone map within the MPDU payload. FIG. 13 shows an example of this preferred implementation. In this case, the MPDU header will indicate the location within the MPDU payload where a tone map change occurs. Thus, the MPDUs payload duration need not be aligned to the tone map boundaries. As shown in FIG. 8, the AC line phase experienced by the transmitter (Station A) may not be offset from the phase experienced by the receiver (Station B). This can result from various causes, including the two stations being on different phases of the AC power in the building, or inductive loading from an AC motor. Generally, it is desirable that the tone maps used be prescribed by the phase of the receiver. For that to happen, the transmitter must be made aware of the relative phase offset of the receiver from the transmitter. A wide variety of implementations are possible for achieving this result. One implementation uses knowledge of the AC zero crossing at each station. A circuit at both the transmitter and receiver, tracks the rising edge of the AC line cycle zero crossing, and information characterizing the offset of the zero crossings is transmitted to the other station. For example, the transmitter (Station A in FIG. 9) may insert the offset of the current time from AC zero crossing (TA,zc,Offset) just before transmitting a packet, The receiver may then store its local AC zero crossing offset (TB,zc,Offset) upon reception of the packet. The difference between the local and received zero crossing offsets (TB,zc,Offset-TA,zc,Offset) provides the relative phase offset of the receiver from the transmitter. Information relating to the phase offset can be sent back to the transmitter in another packet so that tone maps used by the transmitter can be synchronized to the zero crossing at the receiver. Alternatively, the transmitter could determine the offset, by itself, based on zero crossing offset information received from the receiver. Another implementation uses a centralized approach, wherein one station (referred to as the synchronizer station) in the network has a circuit for tracking the rising edge of the AC line cycle zero crossing. The packet format for this implementation enables the transmission of the zero crossing offset between the synchronizer station and all other stations in the network (e.g., by broadcast to all stations in the network and/or unicast to each individual station). All stations in the network track the AC line cycle zero crossing of the synchronizer station and use it as their own local AC line cycle zero crossing. FIG. 10 shows an example of a circuit that can be used to track the synchronizer station zero crossing. This circuit computes the expected zero crossing period based on a feedback loop. Tone map boundaries of all stations in the network are synchronized as all stations track the same synchronizer station zero crossing. Various alternatives to tracking the rising edge of the AC line cycle zero crossing are possible. For example, a circuit tracking the falling edge of the AC Line cycle zero crossing can be used. Alternatively, a circuit tracking the zero crossing (irrespective of whether it is the rising or falling edge) of the AC line cycle can be used. And a circuit tracking a certain phase (for example, a peak of one polarity of the other) can be tracked in place of zero crossings. Another of the many possibilities is a circuit that tracks the synchronous noise on the line cycle. The physical tracking of the zero crossing can also be replaced by virtual tracking. To use virtual tracking, a station uses its local clock along with knowledge of the AC line cycle frequency to track a virtual zero crossing. If the local clocks are not tightly synchronized, stations may exchange time stamps to obtain tight synchronization. Time stamps of various types can be sent while channel adaptation is in progress or during regular transmissions. Many other implementations of the invention other than those described above are within the invention, which is defined by the following claims. | <SOH> BACKGROUND <EOH>Communication systems are designed to reliably transfer information using the underlying physical medium. Well-known communication systems like Ethernet use special wiring (e.g., Cat 5 cable) for exchanging information. Such systems, by design, allow all connected stations to exchange data at a fixed data rate. With the increasing need for ubiquitous exchange of information, a new class of no-new-wire systems has emerged. Such systems use existing infrastructure to exchange information. Power line communication systems are one example of such systems. Power line communication systems use existing AC wiring to exchange information. Owing to their being designed for much lower frequency transmissions, AC wiring provides varying channel characteristics at the higher frequencies used for data transmission (e.g., depending on the wiring used and the actual layout). To maximize the data rate between various links, stations need to adjust their transmission parameters dynamically in both time and frequency. This process is called channel adaptation. Channel adaptation results in a set of transmission parameters (referred to as tone maps in this document) that can be used on each link. Tone maps include such parameters as the frequencies used, their modulation, and the forward error correction (FEC) used. In high-speed power line communication systems, good channel adaptation is critical to providing high data rates on all links. | <SOH> SUMMARY <EOH>We have discovered that higher data rates can be achieved in power line communication systems by taking into account the fact that the noise and/or the frequency response of the power line channel between any pair of stations depends on the AC line cycle phase. Power line communication systems share the power line medium with various appliances that draw electric power from the power supply grid. These devices are some of the major sources of noise that affect the characteristics of power line channels. Several types of such devices generate noise that varies with the AC line cycle phase and the carrier frequencies. FIG. 1 shows an example wherein the noise around the zero crossing on the AC line cycle is lower by comparison to the noise at the peaks of the AC cycle. Devices like triac-controlled dimmers turn on and off during each AC line cycle. These not only generate impulse noise but also change the channel frequency response. Further, several devices that use AC motors (e.g., vacuum cleaners, drills, etc.) generate noise that is also a function of the phase of the line cycle. The net effect is a time varying channel whose noise characteristics and frequency response depend on the AC line cycle phase. In general the invention features a method of operating in a network in which a plurality of stations communicate over a shared medium having a periodically varying channel. The method includes determining a plurality of channel adaptations for communication between a pair of stations, and assigning a different one of the plurality of channel adaptations to each of a plurality of phase regions of the periodically varying channel. In preferred implementations, one or more of the following features may be incorporated. The channel adaptations for a particular phase region may be adapted to the channel in that phase region. The network may be a power line communication network, the shared medium may be an AC power line (inside or outside a building and low, medium, or high voltage), and the channel characteristics may vary with the phase of the AC line cycle. Channel adaptation may be synchronized to the periodically varying channel. Channel adaptation may be substantially unique between any pair of transmitter and receiver. Each station may have a channel adaptation facility that interacts with the channel facility at other stations. The channel adaptation facility may include a tone map generator for generating a tone map. The channel adaptation facility may include an indication of the start of the AC line cycle. The stations may exchange tone maps. The tone map generator may have the capability to generate multiple tone maps, with different tone maps being assigned to different phases regions of the AC line cycle. Different tone maps may be assigned to different regions of each half cycle of the AC line cycle, with each half cycle of the AC line cycle being treated as equivalent to the other half cycle for the purpose of channel adaptation. The AC line cycle may be divided into a plurality of substantially equal size phase regions, to which a different tone map may be assigned. Some of the substantially equal size phase regions may be assigned the same tone map. Associated with each tone map may be an indication of the tolerance of that tone map for use outside its boundaries. The indication of the start of an AC line cycle may include recognition of an AC line cycle zero crossing. The indication of the start of an AC line cycle may include recognition of an AC line cycle zero crossing followed by a rising signal. The indication of the start of an AC line cycle may include recognition of an AC line cycle zero crossing followed by a falling signal. The indication of the start of an AC line cycle may include recognition of a repeating feature in the AC line signal. The repeating feature in the AC line signal may include one or more of the following: a zero crossing, a peak in AC power amplitude, a peak or a minimum in noise amplitude. Time stamps may be transmitted between stations to aid synchronization of channel adaptation to the AC line cycle. The phase of the AC line cycle at a receiving station may be offset from the AC line cycle at a transmitting station, and information relating to the phase offset may be provided to the transmitting station so that the channel adaptation used by the transmitting station is synchronized to the AC line cycle at the receiving station. The information relating to the phase offset may include a zero crossing offset between the receiving and transmitting stations. The receiving station may determine the zero crossing offset, and transmit it to the transmitting station. The transmitting station may determine the zero crossing offset. One station in the network may track the AC line cycle zero crossing and transmit information on the time of the zero crossing to a plurality of stations on the network, and the plurality of stations may use the time of the zero crossing at the one station as their own local AC line cycle zero crossing. The AC line cycle zero crossing may be derived using virtual tracking, wherein a station uses its local clock along with knowledge of the AC line cycle frequency to track a virtual zero crossing. The number of tone map regions, boundaries of each region, and the tone map for each region may be determined based on periodically varying channel attenuation characteristics or on periodically varying local noise characteristics. If data is transmitted in packets that include at least one header and one payload, the tone map boundaries and length of the packets may be configured so that the payload of most packets is transmitted within one phase region so that a payload does not cross a boundary between tone maps. Or the tone map boundaries and length of the packets may be configured so that the payload of at least some packets is transmitted in two adjoining phase regions, so that a first portion of the payload is transmitted using one tone map and a second portion of the payload is transmitted using a second tone map. Among the many advantages of the invention (some of which may be achieved only in some of its implementations) are the following. It enables stations to operate reliability and at higher data rates under various power line environments. It provides a channel adaptation mechanism that can be used in power line communication systems as well as other media that are affected by periodically varying channel impairments. It can provide a higher level of guaranteed quality of service (QoS). | 20040226 | 20100511 | 20050901 | 63129.0 | 0 | CHERY, DADY | CHANNEL ADAPTATION SYNCHRONIZED TO PERIODICALLY VARYING CHANNEL | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,787,558 | ACCEPTED | Turbine blade shroud cutter tip | A shroud for use with a turbine blade is disclosed wherein the shroud provides at least one knife edge with at least one tooth for cutting a groove in a compliant rub strip that minimizes wear on the knife edge. The tooth is positioned along the knife edge a distance substantially away from the ends of the knife edge such that the moment created by the tooth mass and its effect on shroud bending stress is significantly reduced, thereby resulting in increased turbine blade durability. | 1. A turbine blade having reduced bending stresses at a blade tip region, said turbine blade comprising: an attachment extending generally parallel to an axis and having a plurality of serrations generally parallel with said axis; a neck extending radially outward from said attachment; a platform of generally planar shape extending radially outward from said neck; an airfoil extending radially outward from said platform and having a generally radially extending stacking line; a shroud extending radially outward from said airfoil, said shroud comprising: a first surface fixed to said airfoil opposite said platform; a second surface in spaced relation to and generally parallel to, said first surface; a plurality of radially extending sidewalls, generally perpendicular to, and connecting said first and second surfaces; at least one knife edge extending outward from said second surface, said knife edge extending across said second surface, having a first height, and knife ends at said sidewalls; and, at least one tooth positioned immediately adjacent said at least one knife edge a distance substantially away from said knife ends; 2. The turbine blade of claim 1 further comprising a plurality of cooling holes extending radially from said attachment, through said neck, platform, and airfoil, to said shroud in order to provide a cooling fluid to said turbine blade. 3. The turbine blade of claim 2 wherein said cooling fluid is compressed air. 4. The turbine blade of claim 1 wherein said at least one tooth has a second height substantially equal to said first height of said knife edge. 5. The turbine blade of claim 1 wherein said at least one knife edge and said at least one tooth are integrally cast into said turbine blade. 6. The turbine blade of claim 1 wherein said at least one knife edge is generally perpendicular to said axis. 7. The turbine blade of claim 1 wherein said at least one tooth comprises two teeth. 8. The turbine blade of claim 7 wherein said teeth are spaced apart along said knife edge an equal distance from said stacking line of said airfoil. 9. The turbine blade of claim 1 wherein said at least one knife edge comprises two parallel knife edges. 10. A shroud for use with a turbine blade for reducing bending stresses at a blade tip region, said shroud comprising: a first surface fixed to an airfoil; a second surface in spaced relation to and generally parallel to, said first surface; a plurality of radially extending sidewalls, generally perpendicular to, and connecting said first and second surfaces; at least one knife edge extending outward from said second surface, said knife edge extending across said second surface, having a first height, and knife ends at said sidewalls; and, at least one tooth positioned immediately adjacent said at least one knife edge a distance substantially away from said knife ends; 11. The shroud of claim 10 wherein said at least one tooth has a second height substantially equal to said first height of said knife edge. 12. The shroud of claim 10 wherein said at least one knife edge and said at least one tooth are integrally cast into a turbine blade. 13. The shroud of claim 10 wherein said at least one knife edge is generally perpendicular to an axis of a turbine blade. 14. The shroud of claim 10 wherein said at least one tooth comprises two teeth. 15. The shroud of claim 14 wherein said teeth are spaced apart along said knife edge an equal distance from a stacking line of a turbine blade airfoil. 16. The shroud of claim 10 wherein said at least one knife edge comprises two parallel knife edges. | TECHNICAL FIELD This invention relates to shrouded turbine blades and more specifically to an improved cutter tip design that reduces the bending stresses in the shroud to airfoil interface region of a turbine blade. BACKGROUND OF THE INVENTION Gas turbine engines have compressor and turbine blades of varying length in order to compress and expand the fluid flow passing through the engine. For the turbine section, as energy is extracted from the hot combustion gases, the fluid expands and the turbine section expands accordingly, including the stages of turbine blades. As turbine blade length increases, the blades become more susceptible to vibration and require dampening. In order to dampen the vibrations, a shroud is added to the blade, most often at the blade tip. The shroud serves to reduce blade vibrations by interlocking adjacent turbine blade tips, as well as to seal the blade tip region to prevent hot combustion gases from leaking around the blade tip and bypassing the turbine. While this sealing and dampening design is effective, the use of a shroud causes additional load and stress on the turbine blade due to its shape, weight, and position. Specifically the shroud has a radial stress component on the blade attachment due to its weight and radial position. Furthermore, the shroud exhibits a bending moment at the interface region between the shroud and airfoil due to the large mass cantilevered along the edges of the shroud. This bending moment is further complicated by the mass due to a cutter tooth located along at the edge of the shroud knife edge. As the operating temperature of the turbine blade increases, it stretches radially outward and approaches an outer compliant rub strip that surrounds the row of turbine blades. The rub strip is typically fabricated from segments of honeycomb. The cutter tooth is designed to cut a groove in the honeycomb of the surrounding rub strip to allow the shroud sufficient area under all operating conditions to seal and not adversely contact the rub strip. Depending on the size and position of the cutter tooth, the bending moment between the shroud and airfoil increases, and the associated shroud bending stresses will increase by as much as 20%, thereby reducing the durability of the shroud. An example of this type of shroud design is shown in FIG. 1. A shroud 10 is fixed to airfoil 11. Extending radially outward from shroud 10 is knife edge 12 having a cutter tooth 13 located at one end thereof. As discussed previously, cutter tooth 13 is designed to cut a groove in the honeycomb of the surrounding compliant rub strip to allow the shroud sufficient area under all operating conditions to seal and not adversely contact the rub strip. In this prior art shroud design, cutter tooth 13 is positioned at one end of knife edge 12 and while it cuts a sufficient groove into the surrounding rub strip for knife edge 12, cutter tooth 13 causes a large bending moment at the airfoil to shroud interface due to the distance from the center of the shroud to the cutter tooth. The present invention seeks to overcome the shortcomings of the prior art by providing a turbine blade shroud configuration having a cutter tooth design that results in lower shroud bending stresses. SUMMARY AND OBJECTS OF THE INVENTION A shrouded turbine blade having reduced bending stresses at the blade tip region is disclosed. In general, the turbine blade comprises an attachment, neck, platform, airfoil, and shroud. More specifically, the shroud comprises a first surface fixed to an end of the airfoil, a second surface in spaced relation and generally parallel to the first surface, with a plurality of radially extending sidewalls connecting the first surface and second surface to give the shroud a thickness. Extending outward from the shroud second surface and across the second surface is at least one knife edge having knife ends at the shroud sidewalls. Positioned immediately adjacent the at least one knife edge yet a distance substantially away from the knife ends is at least one tooth used for cutting a groove in a compliant rub strip that surrounds the turbine blade tip. The tooth, which in prior art shroud designs, has been known to be a significant factor in shroud bending stresses, is repositioned to reduce its bending moment on the airfoil to shroud region and associated shroud bending stresses. It has been determined that the tooth can be repositioned without compromising cutting performance, while at the same time reducing shroud bending stresses for the preferred embodiment by approximately 18% over the prior art configuration. It is an object of the present invention to provide a shrouded turbine blade having lower shroud bending stresses. It is another object of the present invention to provide a shrouded turbine blade with smaller clearances between the blade tip and surrounding seal. In accordance with these and other objects, which will become apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a perspective view of a turbine blade shroud of the prior art. FIG. 2 is a perspective view of a turbine blade incorporating a shroud in accordance with the present invention. FIG. 3 is a detailed perspective view of a turbine blade shroud in accordance with the present invention. FIG. 4 is an elevation view of a tip portion of a turbine blade in accordance with the present invention. FIG. 5 is a top view of a shroud in accordance with an alternate embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 2, a turbine blade 20 incorporating the present invention is shown. Turbine blade 20 comprises an attachment 21 that extends generally parallel to an axis A-A and has a plurality of serrations 22 for attaching turbine blade 20 to a blade disk (not shown). In the preferred embodiment, serrations 22 are generally parallel to axis A-A. Extending radially outward from attachment 21 is a region 23 commonly referred to as a blade neck. Neck 23 connects to platform 24, which is generally planar in shape. Extending radially outward from platform 24 is airfoil 25, wherein airfoil 25 also includes a generally radially extending stacking line B-B through which sections of the airfoil are stacked to create airfoil 25. Referring now to FIGS. 3 and 4, extending radially outward from airfoil 25 is shroud 26 with the shroud comprising a first surface 27 fixed to airfoil 25 at an end opposite of platform 24, a second surface 28 in spaced relation to and generally parallel to first surface 27. Extending radially between and generally perpendicular to first surface 27 and second surface 28 is a plurality of sidewalls 29. Fixed to and extending radially outward from second surface 28 is at least one knife edge 30, where knife edge 30 extends across second surface 28, has a first height H1, and knife ends 31 proximate sidewalls 29. In the preferred embodiment, knife edge 30 extends across second surface 28 such that knife edge 30 is generally perpendicular to axis A-A. Positioned immediately adjacent knife edge 30, but a distance substantially away from knife end 31, is at least one tooth 32, having a second height H2, that is substantially equal to knife edge first height H1. At least one tooth is positioned adjacent the knife edge of a turbine blade shroud in order to cut a groove in a surrounding compliant rub strip for the relatively thin knife edge of the shroud such that a seal between the turbine blade and surrounding rub strip is provided. Cutting a slot wider than the width of the knife edge ensures the thinner knife edge will not contact the rub strip and adversely wear. Cutting a wider slot with margin on either side of the knife edge to compensate for shroud movement can be accomplished by multiple cutter teeth as shown in FIG. 3. In this configuration, teeth 32 are spaced apart along knife edge 30 an equal distance from stacking line B-B of airfoil 25 in order to provide a more even stress distribution. In the preferred embodiment of the present invention, knife edge 30 and at least one tooth 32 are both integrally cast into turbine blade 20. Although being cast into the turbine blade, typically the height of the tooth and knife edge are determined by a final blade machining process. Depending on the operating temperatures of the turbine, often times turbine blades require cooling in order to reduce the overall blade temperature to an acceptable level for the blade material. An example of blade cooling is shown in FIGS. 2-4, where turbine blade 20 includes a plurality of cooling holes 33 that extend radially from attachment 21 through neck 23, platform 24, airfoil 25, and to shroud 26 in order to provide a cooling fluid to turbine blade 20. Depending on the cooling requirements, compressed air or steam can be used to cool the turbine blade, but for the embodiment disclosed in FIGS. 2 and 3, compressed air is the preferred cooling medium. Depending on the size of the turbine blade shroud, more than one knife edge may be necessary in order to provide an effective seal between the turbine blade and surrounding compliant rub strip. An example of this alternate shroud configuration is shown in FIG. 5. Shroud 46 includes all of the elements of the preferred embodiment of the shroud, but instead of a single knife edge, utilizes a pair of knife edges 50 that are parallel to one another. Furthermore, each knife edge includes at least one tooth 52 for cutting a path in a compliant rub strip that surrounds the turbine blades containing shrouds 46. One skilled in the art of turbine blade design will understand that the use of this type of shroud configuration is independent of the turbine blade geometry. Therefore, the shroud and knife edge geometry disclosed herein could be used in combination with other airfoil, platform, neck, and attachment configurations. While the invention has been described in what is known as presently the preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment but, on the contrary, is intended to cover various modifications and equivalent arrangements within the scope of the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Gas turbine engines have compressor and turbine blades of varying length in order to compress and expand the fluid flow passing through the engine. For the turbine section, as energy is extracted from the hot combustion gases, the fluid expands and the turbine section expands accordingly, including the stages of turbine blades. As turbine blade length increases, the blades become more susceptible to vibration and require dampening. In order to dampen the vibrations, a shroud is added to the blade, most often at the blade tip. The shroud serves to reduce blade vibrations by interlocking adjacent turbine blade tips, as well as to seal the blade tip region to prevent hot combustion gases from leaking around the blade tip and bypassing the turbine. While this sealing and dampening design is effective, the use of a shroud causes additional load and stress on the turbine blade due to its shape, weight, and position. Specifically the shroud has a radial stress component on the blade attachment due to its weight and radial position. Furthermore, the shroud exhibits a bending moment at the interface region between the shroud and airfoil due to the large mass cantilevered along the edges of the shroud. This bending moment is further complicated by the mass due to a cutter tooth located along at the edge of the shroud knife edge. As the operating temperature of the turbine blade increases, it stretches radially outward and approaches an outer compliant rub strip that surrounds the row of turbine blades. The rub strip is typically fabricated from segments of honeycomb. The cutter tooth is designed to cut a groove in the honeycomb of the surrounding rub strip to allow the shroud sufficient area under all operating conditions to seal and not adversely contact the rub strip. Depending on the size and position of the cutter tooth, the bending moment between the shroud and airfoil increases, and the associated shroud bending stresses will increase by as much as 20%, thereby reducing the durability of the shroud. An example of this type of shroud design is shown in FIG. 1 . A shroud 10 is fixed to airfoil 11 . Extending radially outward from shroud 10 is knife edge 12 having a cutter tooth 13 located at one end thereof. As discussed previously, cutter tooth 13 is designed to cut a groove in the honeycomb of the surrounding compliant rub strip to allow the shroud sufficient area under all operating conditions to seal and not adversely contact the rub strip. In this prior art shroud design, cutter tooth 13 is positioned at one end of knife edge 12 and while it cuts a sufficient groove into the surrounding rub strip for knife edge 12 , cutter tooth 13 causes a large bending moment at the airfoil to shroud interface due to the distance from the center of the shroud to the cutter tooth. The present invention seeks to overcome the shortcomings of the prior art by providing a turbine blade shroud configuration having a cutter tooth design that results in lower shroud bending stresses. | <SOH> SUMMARY AND OBJECTS OF THE INVENTION <EOH>A shrouded turbine blade having reduced bending stresses at the blade tip region is disclosed. In general, the turbine blade comprises an attachment, neck, platform, airfoil, and shroud. More specifically, the shroud comprises a first surface fixed to an end of the airfoil, a second surface in spaced relation and generally parallel to the first surface, with a plurality of radially extending sidewalls connecting the first surface and second surface to give the shroud a thickness. Extending outward from the shroud second surface and across the second surface is at least one knife edge having knife ends at the shroud sidewalls. Positioned immediately adjacent the at least one knife edge yet a distance substantially away from the knife ends is at least one tooth used for cutting a groove in a compliant rub strip that surrounds the turbine blade tip. The tooth, which in prior art shroud designs, has been known to be a significant factor in shroud bending stresses, is repositioned to reduce its bending moment on the airfoil to shroud region and associated shroud bending stresses. It has been determined that the tooth can be repositioned without compromising cutting performance, while at the same time reducing shroud bending stresses for the preferred embodiment by approximately 18% over the prior art configuration. It is an object of the present invention to provide a shrouded turbine blade having lower shroud bending stresses. It is another object of the present invention to provide a shrouded turbine blade with smaller clearances between the blade tip and surrounding seal. In accordance with these and other objects, which will become apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings. | 20040226 | 20060822 | 20050901 | 66397.0 | 0 | EDGAR, RICHARD A | TURBINE BLADE SHROUD CUTTER TIP | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,787,573 | ACCEPTED | Fluid ejection device metal layer layouts | A fluid ejection device comprises a first metal layer and a second metallayer. The first metal layer comprises an address path portion and a nonaddress path portion. The second metal layer, which overlies the first metal layer, comprises a first portion which comprises a power conducting portion. The power conducting portion is routed only over the non-address path portion of the first metal layer. | 1. A fluid ejection device, comprising: a first metal layer comprising an address path portion and a non-address path portion; a second metal layer overlying the first metal layer, the second metal layer comprising a first metal portion which overlies only the non-address path portion of the first metal layer, wherein the first portion is a power conducting portion. 2. The fluid ejection device of claim 1, wherein the second metal layer further comprises a second portion which overlies the address path portion and is electrically isolated from the first portion. 3. The fluid ejection device of claim 2, wherein the second portion comprises a second-metal-layer ground portion. 4. The fluid ejection device of claim 3, wherein: the first metal layer comprises a first-metal-layer ground portion; and the second-metal-layer ground portion overlaps a portion of the first-metal-layer ground portion and is electrically connected to the first-metal-layer ground portion. 5. The fluid ejection device of claim 2, wherein: the second metal layer comprises a first conductive layer portion having a first resistivity and a second conductive layer portion having a second resistivity, wherein the first resistivity is less than the second resistivity; and the second portion comprises the second conductive layer portion and does not comprise the first conductive layer portion. 6. The fluid ejection device of claim 5, wherein the second conductive layer portion comprises tantalum. 7. The fluid ejection device of claim 6, wherein the first conductive layer portion comprises gold. 8. A fluid ejection device comprising: a first metal layer comprising a resistor portion, the resistor portion defining a swath height; and a second metal layer over the first metal layer, the second metal layer comprising a second-metal-layer ground portion routed through the swath height. 9. The fluid ejection device of claim 8, wherein the first metal layer further comprises a first-metal-layer ground portion which is electrically connected to the second-metal-layer ground portion. 10. The fluid ejection device of claim 8, wherein the first metal layer further comprises an address path portion, and the second-metal-layer ground portion is routed over the address path portion. 11. The fluid ejection device of claim 8, wherein: the first metal layer further comprises a first-metal-layer ground portion and an address path portion; and the second-metal-layer ground portion is routed over the address path portion and electrically connected to the first-metal-layer ground portion. 12. A fluid ejection device, comprising: a first metal layer comprising an address path portion; a second metal layer, overlying the first metal layer, wherein the second metal layer comprises a first power conducting portion and a second-metal-layer ground portion, and wherein the first power conducting portion does not overlie the address path portion. 13. The fluid ejection device of claim 12, wherein the second-metal-layer ground portion is routed over the address path portion. 14. The fluid ejection device of claim 13, wherein the first metal layer further comprises a first transistor portion arranged generally parallel with the address path portion. 15. The fluid ejection device of claim 14, wherein the first power conducting portion is routed over the first transistor portion. 16. The fluid ejection device of claim 14, wherein the first metal layer further comprises a first logic portion arranged between the address path portion and the first transistor portion. 17. The fluid ejection device of claim 16, wherein the first metal layer further comprises a first first-metal-layer ground portion arranged between the logic portion and the transistor portion. 18. The fluid ejection device of claim 17, wherein the first first-metal-layer ground portion is electrically connected to the second-metal-layer ground portion. 19. The fluid ejection device of claim 15, wherein: the first metal layer further comprises a second transistor portion arranged generally parallel with the address path portion, the address portion being between the first transistor portion and the second transistor portion. 20. The fluid ejection device of claim 19, wherein the second metal layer further comprises a second power conducting portion, wherein the second power conducting portion is routed over the second transistor portion. 21. A fluid ejection device, comprising: a first metal layer comprising an address path portion and a non-address path portion comprising a ground portion; a second metal layer overlying the first metal layer and comprising a first power conducting portion having a first resistivity and a second conductive portion having a second resistivity which is greater than the first resistivity, wherein the first power conducting portion is routed over the non-address path portion and the second conductive portion is electrically isolated from the ground portion and electrically isolated from the power conducting portion. 22. The fluid ejection device of claim 21, wherein the second conductive portion is routed over the address path portion. 23. The fluid ejection device of claim 21, wherein the second conductive portion comprises tantalum. 24. The fluid ejection device of claim 21, wherein: the non-address path portion comprises a first transistor portion arranged generally parallel with the address path portion. 25. The fluid ejection device of claim 24, wherein the first power conducting portion is routed over the first transistor portion. 26. The fluid ejection device of claim 24, wherein the first metal layer comprises a first logic portion arranged between the address path portion and the first transistor portion. 27. The fluid ejection device of claim 26, wherein the second conductive portion is routed over the address path portion and over the first logic portion. 28. The fluid ejection device of claim 26, wherein the first logic portion is separated from the first transistor portion by at least 30 um. 29. The fluid ejection device of claim 26, wherein the first logic portion is separated from the first transistor portion by at least 100 um. 30. The fluid ejection device of claim 26, further comprising a logic element underlying the first logic portion and a corresponding drive transistor underlying at least in part the first transistor portion, wherein the logic element is separated from the corresponding drive transistor by at least 30 um. 31. The fluid ejection device of claim 30, wherein the logic element is separated from the corresponding drive transistor by at least 100 um. 32. The fluid ejection device of claim 26, wherein the first metal layer comprises a first ground portion arranged between the logic portion and the transistor portion. 33. The fluid ejection device of claim 25, wherein: the non-address path portion further comprises a second transistor portion arranged generally parallel with the address path portion, the address path portion being between the first transistor portion and the second transistor portion. 34. The fluid ejection device of claim 33, wherein the second metal layer further comprises a second power conducting portion routed over the second transistor portion. 35. The fluid ejection device of claim 21, wherein: the second metal layer further comprises a second power conducting portion routed between the first portion and the second conductive portion. 36. The fluid ejection device of claim 35, wherein: the second conductive portion is routed over the address path portion. 37. The fluid ejection device of claim 21, wherein: the second metal layer further comprises a second power conducting portion and a third power conducting portion, the first and second portions being routed on first and second opposed sides of the second conductive portion, and the third portion being routed between the first portion and the second conductive portion on the first opposed side and between the second portion and the second conductive portion on the second opposed side of the second conductive portion. 38. The fluid ejection device of claim 37, wherein the first power conducting portion is electrically connected to a first primitive group of firing resistors in a first column of firing resistors; the second power conducting portion is electrically connected to a second primitive group of firing resistors in a second column of firing resistors; and the third power conducting portion is electrically connected to a third primitive group of firing resistors in the first and second column of firing resistors. 39. The fluid ejection device of claim 22, wherein the address path portion is one of a data path, select path, or enable path. 40. A fluid ejection device, comprising: a first metal layer comprising an address path portion and a non-address path portion; a second metal layer comprising a power bus portion, wherein the power bus portion is routed only over the non-address path portion to reduce capacitive coupling between the power bus portion and the address path portion. 41. The fluid ejection device of claim 40, wherein the second metal layer further comprises a non-power bus portion routed over the address path portion. 42. The fluid ejection device of claim 41, wherein the non-power bus portion comprises a ground portion. 43. A fluid ejection device, comprising: a first metal layer comprising a resistor portion defining a swath height; and a second metal layer over the first metal layer, the second metal layer comprising a ground portion routed through the swath height to reduce energy variation. 44. The fluid ejection device of claim 43, wherein: the first metal layer further comprises an address path portion; the second metal layer further comprises a first power conducting portion, wherein the first power conducting portion is not routed over the address path portion, thereby reducing capacitive coupling between the first power conducting portion and the address path portion; and the ground portion is routed over the address path portion. 45. A fluid ejection device, comprising: a first metal layer comprising a transistor portion, a ground portion running generally parallel to the transistor portion, and a logic portion running generally parallel with the transistor portion and separated from the transistor portion by a distance greater than 5 um, wherein the ground portion runs between the transistor portion and the logic portion and has a width sufficient to reduce energy variation. 46. The fluid ejection device of claim 45, wherein the distance is greater than 30 um. 47. The fluid ejection device of claim 45, wherein the distance is greater than 100 um. 48. A fluid ejection device, comprising: a first metal layer comprising an address path portion; a second metal layer comprising a power conducting portion having a first resistivity and a second conductive portion having a second resistivity which is greater than the first resistivity, wherein the second portion overlies the address path portion; a barrier layer formed over the second metal layer; an orifice plate formed over the barrier layer; an expansion grate through the orifice plate; wherein the expansion grate overlies the second conductive portion. 49. A fluid ejection device, comprising: a first metal layer comprising a transistor portion and a logic portion running generally parallel with the transistor portion and separated from the transistor portion by a distance of greater than 30 um. 50. The fluid ejection device of claim 49, wherein the first metal layer further comprises a ground portion arranged between the logic portion and the transistor portion. 51. A fluid ejection device, comprising: a substrate structure; and a thin film stack formed on the substrate structure, the thin film stack comprising a first metal layer with an address path portion and a non-address path portion, a second metal layer deposited over the first metal layer and having a power conducting portion routed over the non-address path portion. 52. The fluid ejection device of claim 51, wherein the second metal layer further comprises a second portion, the second portion being routed over the address path portion and being electrically separated from the first portion. 53. The fluid ejection device of claim 52, wherein the second portion comprises a second-metal-layer ground portion. 54. The fluid ejection device of claim 53 wherein the first metal layer further comprises a first-metal-layer ground portion which is electrically connected to the second-metal-layer ground portion. 55. The fluid ejection device of claim 52, wherein: the power conducting portion comprises a first metal having a first resistivity; and the second portion comprises a second metal having a second resistivity which is less than the first resistivity and does not comprise the first metal. 56. The fluid ejection device of claim 55, further comprising a barrier layer over the thin film stack and an orifice plate over the barrier layer, wherein the orifice plate comprises an expansion grate which overlies the second portion. 57. The fluid ejection device of claim 55, wherein the first metal comprises gold and the second metal comprises tantalum. 58. The fluid ejection device of claim 55, wherein: the non-address path portion comprises a transistor portion arranged generally parallel with the address path portion. 59. The fluid ejection device of claim 58, wherein the first power conducting portion is routed over the transistor portion. 60. The fluid ejection device of claim 58, wherein the first metal layer comprises a logic portion arranged between the address path portion and the transistor portion. 61. The fluid ejection device of claim 60, wherein the second portion overlies the logic portion and the address path portion. 62. The fluid ejection device of claim 60, wherein the first logic portion is separated from the first transistor portion by at least 30 um. 63. The fluid ejection device of claim 60, wherein the first logic portion is separated from the first transistor portion by at least 100 um. | BACKGROUND OF THE DISCLOSURE Some fluid ejection devices, including, for example, inkjet printheads, have a vertical column of nozzles arranged in a column on a die and defining a swath area. Firing resistors located in a firing chamber below the nozzles are energized, thereby heating fluid in the chamber and causing it to expand and be ejected from the nozzle. Circuitry fabricated on a substrate structure using standard thin film techniques includes a conductive path for carrying electrical power for firing the firing resistors, address signal paths, logic elements, and firing transistors. This circuitry is used to properly energize and operate the firing resistors. Capacitive coupling between the address bus and the fire line or power bus can generate noise and degrade performance. The cost of a fluid ejection device can be reduced by reducing the device die size. Such reduction, however, may adversely impact the size of power conduits, leading to increased energy variation and reduced print quality. Power conduits may comprise gold which is susceptible to delamination. BRIEF DESCRIPTION OF THE DRAWINGS Features and advantages of the invention will be readily appreciated by persons skilled in the art from the following detailed description of exemplary embodiments thereof, as illustrated in the accompanying drawings, in which: FIG. 1 illustrates a block diagram of relative positions of metal portions of an exemplary embodiment of a fluid ejection device. FIG. 2 illustrates an exemplary embodiment of a first metal layer of a fluid ejection device. FIG. 3 illustrates an exemplary embodiment of a second metal layer of the fluid ejection device of FIG. 2. FIG. 4 is a block diagram of relative positions of portions of an exemplary embodiment. FIGS. 5A and 5B are block diagrams of relative positions of metal portions of an alternate exemplary embodiment of a fluid ejection device. FIG. 6 illustrates an exemplary embodiment of a first metal layer of a fluid ejection. FIG. 7 illustrates an exemplary embodiment of a second metal layer of the fluid ejection device of FIG. 6. FIG. 8 illustrates an exemplary embodiment of a layout of a second metal layer of a fluid ejection device. FIG. 9 is a block diagram of the relative positions of portions of an exemplary embodiment of a fluid ejection device. FIG. 10 illustrates a top view of an exemplary embodiment of a fluid ejection device. DETAILED DESCRIPTION OF THE DISCLOSURE In the following detailed description and in the several figures of the drawing, like elements are identified with like reference numerals. FIG. 1 illustrates a simplified cross-sectional view of relative positions of metal layer portions in an exemplary embodiment of metal layer layouts for an exemplary fluid ejection device. A thin film stack 10 comprises a first metal layer 1 and a second metal layer 11. The first metal layer 1 comprises at least an address path portion 6 and non-address path portions. The non-address path portions of the first metal layer 1 may comprise at least a resistor portion 2, a first-metal-layer ground portion 4, and a logic portion 5. In an exemplary embodiment, the first metal layer 1 comprises at least two each of the resistor portion 2, ground portion 4 and logic portion 5, arranged on opposite sides of the address path portion 6. The resistor portion 2 and associated nozzles (FIG. 10) define a swath height 26. The resistor portion 2 comprises a plurality of resistors 21 (FIG. 2). The address path portion 6 comprises an address bus, address lines or conductors, data paths, select or enable paths that are utilized to operate resistors that comprise resistor portion 2, as is known in the art. The address path portion 6 carries signals to logic elements, the logic elements causing particular firing transistors to cause particular corresponding firing resistors to fire in response to the signals. The logic elements include components such as transistors that provide functionality for address signal generation, fire signal coupling, select signal generation, synchronization signal generation and the like. The thin film stack 10 of FIG. 1 also comprises a second metal layer 11 over the first metal layer 1. The second metal layer 11 comprises at least a power conducting portion 7 and a second-metal-layer ground portion 8. The power conducting portions 7 comprise conductive paths, fire lines or power busses for providing an electrical connection to the source of electrical power for firing the resistors 21. In an exemplary embodiment, the second metal layer comprises at least two power conducting portions 7 arranged on opposite sides of the ground portion 8. The power conducting portions 7 are routed, at least in part, over the first-metal-layer ground portions 4 in the first metal layer. The second-metal-layer ground portion 8 is routed through the swath height, substantially parallel with the column 22 of resistors 21, and over and over the logic portions 5 and the address path portion 6 of the first metal layer 1. The outboard edges of the second-metal-layer ground portion 8 overlap the inboard edges of the first-metal-layer ground portions 4. Conductive vias 41 (FIGS. 2-4) provide electrical connections 42 between the first-metal-layer ground portions 4 and the second-metal-layer ground portion 8 in the second metal layer 11. By arranging the layout or topology of the first and second metal layers 1, 11 so that the power conducting portions 7 are not routed over, i.e. do not overlie or overlap, the address path portion 6, the opportunity for noise generation and degraded performance, caused by capacitive coupling between power conducting portions and address path portions, is reduced. Routing the second-metal-layer ground portion 8 through the area of the second metal layer 11 that overlies logic portions 5 and the address path portion 6 of the first metal layer 1, may result in reduced energy variation due to decreased ground resistance resulting from the greater ground area. Providing the second-metal-layer ground portion 8 in the second metal layer avoids costs associated with increased die sizes which result where ground resistance is decreased by widening ground paths in the first metal layer, with corresponding increases in the die size. Routing the second-metal-layer ground portion 8 through the swath height may also increase the improvements in energy variation that can be achieved by increasing the thickness of the second metal layer 11. FIG. 2 illustrates a top view of an exemplary layout or topology of a first metal layer 1 of an exemplary embodiment of a fluid ejection device. The first metal layer 1 is deposited on a substrate structure. The first metal layer 1 is masked and etched to define and fabricate the desired layout and topology of the first metal layer 1 of a portion of fluid ejection device circuitry. The first metal layer defines and comprises resistor portions 2, transistor portions 3, first-metal-layer ground portions 4, logic portions 5 and an address path portion 6. The resistor portions 2 each comprise a plurality of individual resistors 21. In an exemplary embodiment, the resistor portions 2 also comprise heater legs 27 extending beyond the edges of an underlying transistor to provide an electrical connection to the individual resistors 21. In an exemplary embodiment, the resistor portions 2 may be about 168 um wide, the resistors being about 75 um wide and the heater legs 27 extending about 93 um outward from the edge of an underlying drive transistor. In an exemplary embodiment, the transistor portions 3 may be about 156 um wide, the logic portions 5 about 126 um wide and the address path portion about 206 um wide. In the exemplary embodiment of FIG. 2, the first-metal-layer ground portion 4 is routed over the drive transistors. In an exemplary embodiment, the ground portion is about 96 um wide. These dimensions are for one exemplary embodiment; other embodiments may employ other sizes and dimensions. In an exemplary embodiment, the resistors 21 are formed, in part, by etching away at least the conductive layer portion from the resistor portion of the first metal layer. The resistors 21 are arranged in columns 22, although they can be rows as well. FIG. 2 shows eight representative resistors 21 in a column 22. A column of resistors may comprise any number of resistors. In exemplary embodiments, a column of resistors can comprise, for example, 100 resistors or 168 resistors. The transistor portions 3 comprise drive transistor metal portions 31 of individual drive transistors associated with corresponding resistors 2. The drive transistor metal portions 31 are shown with representative, exemplary shapes. It is understood that the details of the form depends on the particular layout and design of the drive transistors. Conductive vias 32 connect the drive transistor metal portions 31 to overlying power conducting portions 7 (FIG. 3). The drive transistor metal portions 31 connect resistors 21 to a source of electrical power, and connect source and drain portions of the drive transistors to the resistors 21 and to the ground portions 4 through vias or PSG contacts through underlying layers (not shown), for example through PSG, poly and/or gate oxide layers. The ground portions 4 comprise a common ground connection or path to ground running between the drive transistor metal portions 31 and the logic portion 5. Ground vias 41 electrically connect the first-metal-layer ground portions 4 to a second-metal-layer ground portion 8 (FIG. 3) in an overlying second metal layer. The logic portion 5 comprises logic element metal portions 51 for individual logic elements 53 (FIG. 4) which are associated with corresponding drive transistors 33 (FIG. 4) and resistors 21. In an exemplary embodiment, the address path portion 6 comprises a plurality of address path portions 61 which carry signals to the logic elements 53, which determine which of the individual firing resistors 21 are to be energized. For each resistor 21, corresponding drive transistors 33 and logic elements 53 operate together to receive and interpret signals from the address path portions and to switch power to the resistor to fire the resistor at appropriate times, responsive to the address signals. FIG. 3 illustrates a top view of an exemplary topology of a second metal layer 11 corresponding to the exemplary embodiment of FIG. 2. The second metal layer 11 overlies the first metal layer 1 (FIG. 2) and is deposited and fabricated using thin film techniques. The second metal layer 11 comprises power conducting portions 7 and a second-metal-layer ground portion 8. The power conducting portions 7 and the second-metal-layer ground portion 8 comprise and are defined by conductive layer portions of the second metal layer, for example, gold. The second metal layer 11 may also comprise a second conductive layer portion 112 underlying first conductive layer portions 113, as shown in FIG. 4. In the exemplary embodiment of FIG. 3, the second-metal-layer ground portion 8 and the power conducting portions 7 comprise conductive layer portions and second conductive layer portions with substantially the same topology. In an exemplary embodiment, the second conductive layer portions may extend beyond the outside edges of the conductive layer portions, for example about 4 um beyond the edges of the conductive layer portions. The power conducting portions 7 are routed over, at least in part, the non-address path portions. In the embodiment of FIG. 3, for example, the power conducting portions 7 are routed over at least a portion of the drive transistor portion 3, for example over at least a portion of the drive transistor metal portions 31 and a portion of the ground portion 4 (FIG. 2). The second-metal-layer ground portion 8 is routed alongside and between the columns 22 of resistors 21 in the first metal layer 1, over the logic portions 5 and address portion 6 of the first metal layer 1 (FIG. 2). In this exemplary embodiment, the power conducting portions 7 do not overlie any portion of the address path portion 6 (FIG. 2). In an exemplary embodiment, the power conducting portions 7 are about 196 um wide and the second-metal-layer ground portion 8 is about 475 um wide. FIG. 4 illustrates a diagram of relative positions of the first metal layer portions and the second metal layer portions of a thin film stack 10 of an fluid ejection device for the exemplary embodiments shown in FIGS. 1-3. The first metal layer 1 comprises the firing resistor portions 2, transistor portions 3, including the drive transistor metal portions 31 and the ground portions 4, logic portions 5, and the address path portion 6. The first metal layer 1 comprises a resistive layer portion 13 and a conductive layer portion 14. In an exemplary embodiment, the resistive layer portion comprises TaAl and the conductive layer portion comprises AlCu. A passivation layer 12 separates the first metal layer 1 from the second metal layer 11. In an exemplary embodiment, the passivation layer 12 comprises, for example, SiC and/or SiN. The first metal layer 1 is deposited on a substrate structure 15. In an exemplary embodiment, the substrate structure 15 includes a silicon substrate, gate oxide layer, doped regions, PSG and poly layers (not shown). Drive transistors 33 and logic elements 53 are defined in the substrate structure 15. The transistor portions 3 overlie at least a portion of the drive transistors 33 and the logic portions 5 overlie the logic elements 53. The second metal layer 11 comprises power conducting portions 7 and a second-metal-layer ground portion 8. The second-metal-layer ground portion 8 overlies the address path portion 6, logic element metal portions 5 and the inboard edges of the ground portions 4. The second-metal-layer ground portion 8 is connected to the ground portions 4 by conductive vias 41. The power conducting portions 7 do not overlie the address path portion 6. The power conducting portions 7 are connected to the drive transistor metal portions 3 through conductive vias 32. The second metal layer comprises at least a first conductive layer portion 113 and may further comprise a second conductive layer portion 112. The second conductive layer portion 112 has a resistivity which is greater than the resistivity of the first conductive layer portion 113. In an exemplary embodiment, the first conductive layer portion 113 comprises gold, which may have a resistivity of about 0.08 Ohm/sq. In an exemplary embodiment, the first conductive layer portion 113 may compromise a layer of gold about 0.36 um thick. In other embodiments, the first conductive layer portion 113 may compromise a layer of gold with a thickness within a range of about 0.3 um to about 1.5 um. The first conductive layer portion 113 may comprise AlCu. In an exemplary embodiment, the second conductive layer portion 112 comprises tantalum, which may have a resistivity of about 60 ohm/sq. The second conductive layer portion 112 may comprise a layer of tantalum about 0.3 um thick. In other embodiments, the layer of tantalum may have a thickness within a range of about 0.0 to 0.5 um. The second conductive layer portion may comprise, for example, tantalum. Depositing a tantalum layer portion 112 before depositing a gold layer portion 113 may improve the adhesion of the gold layer. FIG. 5A illustrates a simplified illustration of the relative layout of metal layer portions in an alternate exemplary embodiment of a thin film stack 10 of an exemplary fluid ejection device. The thin film stack 10 comprises a first metal layer 1 and a second metal layer 11. The first metal layer 1 comprises at least a resistor portion 2, a first-metal-layer ground portion 4, a logic portion 5 and an address path portion 6. In an exemplary embodiment, the first metal layer comprises at least two each of a resistor portion 2, ground portion 4, and the logic portion 5, arranged on opposing sides of the address path portion 6. The resistor portions 2 each comprise a column 22 of individual resistors 21 (FIG. 6). The second metal layer 11 comprises at least a power conducting portion 9 and a second conductive portion 8′. The second conductive portion 8′ is electrically isolated from the power conducting portion 9. The second conductive portion 8′ is routed over the address path portion 6 and logic portions 5. In an exemplary embodiment, the second metal layer 11 comprises at least two power conducting portions 9, arranged on opposed sides of the second conductive portion 8′. FIG. 5B illustrates a simplified illustration of the relative layout of metal layer portions in an exemplary embodiment of a thin film stack 10 of an exemplary fluid ejection device. The second metal layer 11 comprises power conducting portions 7 and 9. In an exemplary embodiment, the arrangement of FIG. 5A and the arrangement of FIG. 5B correspond to the arrangement in two different parts of the circuitry of a fluid ejection device. For example, the layout of the second metal layer 11 of FIG. 5A may correspond to the layout in those portions of the second metal layer 11 of FIG. 8 where the power conducting portions 7 and 9 are routed alongside each other. The layout of the second metal layer 11 of FIG. 5B may correspond to the layout in the portions of the second metal layer 11 of FIG. 8 where the power conducting portions 9 are routed beyond the ends of the power conducting portions 7. By arranging the layout or topology of the first and second metal layers 1, 11 so that the power conducting portions 7 and/or 9 are not routed over the address path portion 6 and so that the second portion 8′ is electrically isolated from the power conducting portions 7 and 9, the arrangements of FIGS. 5A and 5B reduce the opportunity for noise generation caused by capacitive coupling between power conducting portions and address path portions. Providing the second metal layer 11 with a second conductive portion 8′ which comprises tantalum may reduce delamination of the second metal layer 11 from an overlying barrier layer. FIG. 6 illustrates a simplified top view of an alternate, exemplary embodiment of a first metal layer 1 of a fluid ejection device. The first metal layer comprises an address path portion 6 and non-address path portions. The non-address path portions comprise resistor portions 2, transistor portions 3, first-metal-layer ground portions 4 and logic portions 5. The resistor portion 2 comprises a plurality of individual resistors 21 arranged in a column 22. The transistor portion 3 comprises drive transistor metal portions 31 of individual drive transistors associated with corresponding resistors 21, and which overlie the underlying drive transistors 33 (FIG. 9). Conductive vias 32 electrically connect the drive transistor portions 31 to overlying power conducting portions 7, 9 (FIG. 7). The logic portions 5 overlie underlying logic elements 53 which are defined in the substrate structure 15 (FIG. 9). The logic portions are not located as close as possible to the transistor portions 3. The logic portions may be separated from the transistor portions 3 by a distance greater than 5 um. In an exemplary embodiment, the logic portions 5 are about 65 um wide and separated from the corresponding transistor portions 3 by about 134 um. In other exemplary embodiments, the logic portions 5 may be separated from corresponding transistor portions by greater than 30 um or greater than 100 um. In the exemplary embodiment of FIG. 6, the first-metal-layer ground portion 4 extends over the underlying transistors 33 and comprises, in part, the transistor portion 3. In an exemplary embodiment, the first-metal-layer ground portion 4 is about 281 um wide. In an exemplary embodiment, the address path portion 6 is about 139 um wide. FIG. 7 illustrates a simplified top view of an alternate exemplary embodiment of a second metal layer corresponding to the embodiment of the first metal layer shown in FIG. 6. The second metal layer comprises power conducting portions 7 and 9, which are defined by and comprise conductive layer portions 71, 91 of the second metal layer 11. The second metal layer also comprises second conductive portions 72, 92 and a second conductive portion 8′ which overlies the address path portion and logic element portions 5 of the underlying first metal layer. In an exemplary embodiment, the second conductive portions 72, 92 may be wider than the corresponding, overlying conductive layer portions 71, 91, and may extend, for example, about 4 um beyond the edges of the overlying conductive layer portions 71, 91. Second conductive layer portions 23 overlie the resistor portions 2 (FIG. 6) of the underlying first metal layer. The second conductive layer portions 23 may protect underlying resistors 21 from damage due to cavitation. The second conductive portions 23, 72, 92 and 8′ are separated by continuous gaps 111 in the second metal layer. The gaps 111 electrically separate the power conducting portions 7, 9 and their respective second conductive portions 71, 91 from one another. The power conducting portions 7 are electrically connected to underlying transistor portions 3 (FIG. 6) of the first metal layer by conductive power vias 32. The power conducting portions 7 provide power to the resistors corresponding to underlying drive transistors. The power conducting portions 9 are routed over the ground portions 4 to provide power to drive transistors and resistors further along the columns (FIG. 8). FIG. 8 illustrates an exemplary layout of the second metal layer 11 for the embodiments illustrated in FIGS. 5A-7. In this embodiment, the second metal layer 11 comprises six power conducting portions—four power conducting portions 7 and two power conducting portions 9, the power conducting portions being defined by conductive layer portions 71, 91 of the second metal layer 11. The second metal layer also comprises corresponding second conductive portions 72, 92 which extend beyond the edges of the conductive portions 71, 91 and second conductive portions 23, which overlies the resistor portion 2 (FIG. 6) of the first metal layer, and second conductive portion 8′, which overlies the address path portion 6. The second conductive portions 72, 92 extend underneath the conductive portions 71, 91 in the power conducting portions 7, 9. The second conductive portions 72, 92 and 8′ are separated by continuous gaps 111 in the second metal layer. In exemplary embodiments, the continuous gaps 111 may be from 8 um to 20 um. Providing a second metal layer 11 with a second conductive portion 8′ which comprises tantalum may reduce delamination of the second metal layer 11 from an overlying barrier layer. Providing a second metal layer 11 with second conductive portions 72, 92 which extend beyond the edges of conductive portions 71, 91 may prevent delamination of an overlying barrier layer from the second metal layer at the edge of the conductive portions, where the edge of the second metal layer 11 may be exposed. Delamination may be more likely to occur where gold is exposed at the edge of the conductive portions. The four power conducting portions 7 are routed, at least in part, over non-address path portions. In the embodiment of FIG. 8, for example, the power conducting portions 7 are routed over at least those portions of the transistor portions and first-metal-layer ground portion 4 of an underlying first metal layer (not shown) which are associated with corresponding upper- and lower-most groups of resistors. The power conducting portions 9 are routed between the second conductive portions 71 and the respective power conducting portions 7. The power conducting portions 9 extend past the power conducting portions 7 to provide electrical power to groups of drive transistors and resistors toward the middle of the columns. FIG. 9 illustrates relative positions of portions of the first metal layer 1, second metal layer 11 and drive transistors 33 and logic elements 53 in the substrate structure 15, for the exemplary embodiments of the exemplary layouts of FIGS. 5A-8. The first metal layer 1 comprises a conductive layer portion 14 and a resistive layer portion 13. The first metal layer 1 comprises resistor portions 2, drive transistor portions 3, first-metal-layer ground portions 4, logic element portions 5 and an address portion 6. The first metal layer 1 is formed over a substrate, which includes a gate oxide layer, PSG, poly and doped regions. Drive transistors 33 and logic elements 53 are defined in the substrate structure below the drive transistor portions 3 and logic element portions 5 respectively. The logic elements 53 and transistors 33 are not spaced as close to each other as possible. The logic elements 53 and corresponding transistors 33 are separated by a distance greater than 5 um. In an exemplary embodiment, the drive transistors 33 are about 216 um wide and separated from corresponding logic elements 53 by 134 um. Providing a separation between the transistor portion and the logic portion provides additional space for a wider ground portion 4, which may decrease ground resistance, thereby decreasing energy variation and improving performance of the fluid ejection device. A passivation layer 12 separates the first metal layer 1 from the second metal layer 11. The second metal layer comprises a second conductive layer portion 112 and a first conductive layer portion 113. The second conductive layer portion 112 comprises second conductive portions 72, 92, 8′ and 23. The second conductive portions 72 are routed over the drive transistor portions 3, the second conductive portions 92 are routed over the first-metal-layer ground portions 4, the second conductive portion 8′ is routed over the address path portion 6 and the second conductive portions 23 are routed over the resistor portions 2. The first conductive layer portion 113 comprises conductive portions 71, 91 which define and comprise power conducting portions 7, 9. The conductive portions 71, 91 are routed over the second conductive portions 72 and 92, respectively. In an exemplary embodiment, no power conducting portion is routed over the address path portion 6. FIG. 10 illustrates an isometric view of an exemplary embodiment of a fluid ejection device 100. The fluid ejection device comprises an orifice layer 101, a barrier layer 102 and a substrate structure 15. In an exemplary embodiment, the orifice layer 101 may comprise an orifice plate 101, which may comprise metal. The orifice layer 101 comprises at least one column 24 of nozzles 25. In the embodiment of FIG. 10, two columns 24 of nozzles 25 are shown. It is understood that an orifice layer 101 may comprise more columns 24 of nozzles 25. Each nozzle 25 corresponds to a resistor 21 in an underlying first metal layer 11. The nozzles 25 may be arranged in primitive groups, the nozzles 25 of each group being powered by a common power conducting portion 7 or 9 (FIG. 8). In the exemplary embodiment of FIG. 10, the nozzles 25 are arranged in six groups a-f. Primitive groups a, b, c, and d correspond to nozzles 25, corresponding to resistors 21 which are powered by corresponding power conducting portions 7 of the second metal layer 11 of FIG. 8. The groups e and f correspond to nozzles powered by power conducting portions 9 shown in FIG. 8. FIG. 10 shows a representative number of nozzles in each group. It is understood that the number of nozzles can vary. In an exemplary embodiment, for example, the groups a, b, c and d can each include at least 28 nozzles and groups e and f can include at least 116 nozzles, 58 nozzles from each column 24. In an exemplary embodiment, the orifice plate 101 may comprise openings 16 through the orifice plate. In an exemplary embodiment, the openings 16 overlie the second conductive portion 8′ of FIG. 8, the outlines of which are shown by the dotted line 8′. The openings 16 may comprise an expansion grate which accommodates and reduces the likelihood of damage from thermal expansion. Arranging the expansion grates 16 such that they overlie the second conductive portion 8′, instead of overlying gold, may reduce the likelihood of delamination between the barrier layer and the second metal layer. Providing a second metal layer in which the second conductive layer portions extend beyond the edges of the conductive layer portions may reduce the likelihood of problems caused by shorts and/or delamination. It should be noted that the terms line, bus, or path apply to any conductive path that is of sufficient conduction to provide a signal path for a particular type of signal to propagate. It is understood that the above-described embodiments are merely illustrative of the possible specific embodiments which may represent principles of the present invention. Other arrangements may readily be devised in accordance with these principles by those skilled in the art without departing from the scope and spirit of the invention. | <SOH> BACKGROUND OF THE DISCLOSURE <EOH>Some fluid ejection devices, including, for example, inkjet printheads, have a vertical column of nozzles arranged in a column on a die and defining a swath area. Firing resistors located in a firing chamber below the nozzles are energized, thereby heating fluid in the chamber and causing it to expand and be ejected from the nozzle. Circuitry fabricated on a substrate structure using standard thin film techniques includes a conductive path for carrying electrical power for firing the firing resistors, address signal paths, logic elements, and firing transistors. This circuitry is used to properly energize and operate the firing resistors. Capacitive coupling between the address bus and the fire line or power bus can generate noise and degrade performance. The cost of a fluid ejection device can be reduced by reducing the device die size. Such reduction, however, may adversely impact the size of power conduits, leading to increased energy variation and reduced print quality. Power conduits may comprise gold which is susceptible to delamination. | <SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>Features and advantages of the invention will be readily appreciated by persons skilled in the art from the following detailed description of exemplary embodiments thereof, as illustrated in the accompanying drawings, in which: FIG. 1 illustrates a block diagram of relative positions of metal portions of an exemplary embodiment of a fluid ejection device. FIG. 2 illustrates an exemplary embodiment of a first metal layer of a fluid ejection device. FIG. 3 illustrates an exemplary embodiment of a second metal layer of the fluid ejection device of FIG. 2 . FIG. 4 is a block diagram of relative positions of portions of an exemplary embodiment. FIGS. 5A and 5B are block diagrams of relative positions of metal portions of an alternate exemplary embodiment of a fluid ejection device. FIG. 6 illustrates an exemplary embodiment of a first metal layer of a fluid ejection. FIG. 7 illustrates an exemplary embodiment of a second metal layer of the fluid ejection device of FIG. 6 . FIG. 8 illustrates an exemplary embodiment of a layout of a second metal layer of a fluid ejection device. FIG. 9 is a block diagram of the relative positions of portions of an exemplary embodiment of a fluid ejection device. FIG. 10 illustrates a top view of an exemplary embodiment of a fluid ejection device. detailed-description description="Detailed Description" end="lead"? | 20040225 | 20070710 | 20050825 | 71820.0 | 1 | GOLDBERG, BRIAN J | FLUID EJECTION DEVICE METAL LAYER LAYOUTS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,787,607 | ACCEPTED | Realtime billable timekeeper method, system and apparatus | A computer method, system and apparatus for generating and tracking time expended by professionals in providing services to their clients on a realtime basis with all services performed through use of a computer including the realtime tracking and generation of billing entries with respect to the daily generation of Internet-based and local area network (LAN) documents and other Internet-based services such as preparation of e-mails and legal research, through integration with existing computer-based systems and programs. | 1. A method for realtime billable timekeeping using a computer, comprising: detecting opening of a document; and generating a timekeeper entry box corresponding to said document wherein said timekeeper entry box contemporaneously tracks time said document is in use. 2. The method of claim 1, further comprising receiving at least one of a client identifier, a personal code and a subject description for entry within said timekeeper entry box. 3. The method of claim 1, further comprising extracting at least one of a document type, an author identifier, a recipient identifier and a subject description for entry within said timekeeper entry box. 4. The method of claim 1, wherein said timekeeper entry box includes at least one of the following functions: pause, end, erase, minimize, maximize and favorites. 5. The method of claim 1, further comprising storing information obtained from said timekeeper entry box. 6. The method of claim 1, further comprising integrating information obtained from said timekeeper entry box into an accounting and billing system. 7. The method of claim 1, further comprising displaying at least one of a start time, an end time, a total time, a date, a client identifier, a personal code, a document type, an author identifier, a recipient identifier, and a subject description within said timekeeper entry box. 8. The method of claim 1, further comprising displaying a running clock within said timekeeper entry box. 9. The method of claim 1, further comprising requesting permission to track time of said document. 10. A computing device for a realtime billable timekeeper, comprising: a storage device; and a processor connected to said storage device, said storage device storing a program for controlling said processor; said processor operative with said program to, detect opening of a document; and generate a timekeeper entry box corresponding to said document wherein said timekeeper entry box contemporaneously tracks time said document is in use. 11. The computing device of claim 10, wherein said processor is further operative with said program to receive at least one of a client identifier, a personal code and a subject description for entry within said timekeeper entry box. 12. The computing device of claim 10, wherein said processor is further operative with said program to extract at least one of a document type, an author identifier, a recipient identifier and a subject description for entry within said timekeeper entry box. 13. The computing device of claim 10, wherein said timekeeper entry box includes at least one of the following functions: pause, end, erase, minimize, maximize and favorites. 14. The computing device of claim 10, wherein said processor is further operative with said program to store information obtained from said timekeeper entry box. 15. The computing device of claim 10, wherein said processor is further operative with said program to display at least one of a start time, an end time, a total time, a date, a client identifier, a personal code, a document type, an author identifier, a recipient identifier, and a subject description within said timekeeper entry box. 16. The computing device of claim 10, wherein said processor is further operative with said program to display a running clock within said timekeeper entry box. 17. The computing device of claim 10, wherein said processor is further operative with said program to request permission to track time of said document. 18. A computer readable medium having computer executable software code stored thereon for a realtime billable timekeeper, comprising: code for detecting opening of a document; code for generating a timekeeper entry box corresponding to said document wherein said timekeeper entry box contemporaneously tracks time said document is in use. 19. The computer readable medium of claim 18, further comprising code for receiving at least one of a client identifier, a personal code and a subject description for entry within said timekeeper entry box. 20. The computer readable medium of claim 18, further comprising code for extracting at least one of a document type, an author identifier, a recipient identifier and a subject description for entry within said timekeeper entry box. 21. The computer readable medium of claim 18, wherein said timekeeper entry box includes at least one of the following functions: pause, end, erase, minimize, maximize and favorites. 22. The computer readable medium of claim 18, further comprising code for storing information obtained from said timekeeper entry box. 23. The computer readable medium of claim 18, further comprising code for displaying at least one of a start time, an end time, a total time, a date, a client identifier, a personal code, a document type, an author identifier, a recipient identifier, and a subject description within said timekeeper entry box. 24. The computer readable medium of claim 18, further comprising code for displaying a running clock within said timekeeper entry box. 25. The computer readable medium of claim 18, further comprising code for requesting permission to track time of said document. 26. A method for realtime billable timekeeping using a computer, comprising: detecting initiation of a client service; and generating a timekeeper entry box corresponding to said client-service wherein said timekeeper entry box contemporaneously tracks time of said client-service session. 27. A computing device for a realtime billable timekeeper, comprising: a storage device; and a processor connected to said storage device, said storage device storing a program for controlling said processor; said processor operative with said program to, detect initiation of a client-service; and generate a timekeeper entry box corresponding to said client-service wherein said timekeeper entry box contemporaneously tracks time of said client-service session. 28. A computer readable medium having computer executable software code stored thereon for a realtime billable timekeeper, comprising: code for detecting initiation of a client-service; and code for generating a timekeeper entry box corresponding to said client-service wherein said timekeeper entry box contemporaneously tracks time of said client-service session. 29. A method for realtime billable timekeeping using a computer, comprising: detecting initiation of a telephone call; and generating a timekeeper entry box corresponding to said telephone call wherein said timekeeper entry box contemporaneously tracks time of said telephone call. 30. A computing device for a realtime billable timekeeper, comprising: a storage device; and a processor connected to said storage device, said storage device storing a program for controlling said processor; said processor operative with said program to, detect initiation of a telephone call; and generate a timekeeper entry box corresponding to said telephone call wherein said timekeeper entry box contemporaneously tracks time of said telephone call. 31. A computer readable medium having computer executable software code stored thereon for a realtime billable timekeeper, comprising: code for detecting initiation of a telephone call; and code for generating a timekeeper entry box corresponding to said telephone call wherein said timekeeper entry box contemporaneously tracks time of said telephone call. | FIELD OF THE INVENTION The present invention relates to a timekeeping and tracking computer method, system and apparatus on a document-by-document, task-by-task, realtime basis for the purpose of generating associated billing information for an individual services-related professional. The invention also permits the individual to control the time allocated and the description for each document, whether Internet-based or local area network (LAN) based, or task, on a realtime basis through a timekeeper entry box generated for each such document and task. BACKGROUND OF THE INVENTION Electronic time and billing and/or cost systems have evolved from the traditional time log manually recorded on blank sheets of paper or on pre-formatted paper forms. Such systems have been in a constant state of flux and evolution since the introduction of computer technology into the professional working environment. Today, virtually one hundred percent of the documents that are generated and stored in professional offices are computer generated. The need for a realtime computer generated time and billing system for the individual professional is thus essential in today's working environment. This is particularly true for attorneys and other service-related professionals who bill clients based on an hourly rate for time spent on a particular matter where hourly rates vary for each professional, and thus, it is essential to record and bill each professional's time on an individual basis. Moreover, in an increasingly cost conscious environment, clients have justifiably mandated strict guidelines and specific support for all time billed down to the minute. This has increased the burden on professionals such as attorneys to keep a running track record of every hour, every minute, of their billable time and to provide adequate justification for such billable time on a daily basis. Many attorneys and other billing professionals do not record time expended for rendering professional services contemporaneous with the task or service performed. This results in time being lost and never billed due to the inability to remember the task performed or the amount of time spent for performing the task. The absence of a computer system which monitors billable time for every document generated and/or task undertaken during the course of a given day contemporaneous with the service being performed has proven to be an insurmountable burden for many professionals who have a difficult time administratively logging their time on a daily basis. Unfortunately, while there have been numerous attempts to improve existing time and billing systems, none have addressed the need for a timekeeping tracking computer system, method and apparatus on a document-by-document, task-by-task, realtime basis for the purpose of generating a daily billing report for an individual service-related professional. For example, U.S. Pat. No. 5,991,742, entitled “Time and Expense Logging System”, is directed to a portable time and billing system for professionals who are constantly on their feet, do not have access to desktop or notebook computers and may not have typing skills or familiarity with operating a computer. The '742 patent is directed to a computer system which accepts data from the user using an input recognizer such as a handwriting recognizer or speech recognizer. Other computer systems are directed to overall billkeeping or litigation management or cost budgeting. U.S. Pat. No. 6,622,128, entitled “Internet-based attorney-client billing system” is directed to an Internet-based billkeeping and litigation management system, allowing third parties to monitor the progress and expense of litigation and/or possibly other legal matters. U.S. Patent Application Publication No. 20030225989, entitled “System for calculating billable time” is directed to a timing system for tracking the time spent on a client file for cost budget purposes. The timing system does not address the tracking of billable time for an individual professional on a document-by-document, task-by-task, realtime basis for the purpose of generating a daily billing report for that individual professional. The timing system also is not directed to monitoring each newly generated document, whether Internet-based or LAN based, or task of an individual professional on a daily basis. SUMMARY OF THE INVENTION The present invention relates to a timekeeping and tracking computer method, system and apparatus on a document-by-document, task-by-task, realtime basis for the purpose of generating a daily billing report for an individual services-related professional. The manner by which the computer method, system and apparatus may generate, track and record time may be through the use of a software program that generates a timekeeper entry box each time a document or task is being performed by the professional. The timekeeper entry box may appear on the professional's computer screen for each document, task or other service (LAN or Internet-based) performed by the professional. The timekeeper entry box may include a field for entry of a client identifier (client name or billing number). The timekeeper entry box may also include additional fields for entry of information, such as date, document type, description of task being performed and billing professional identifier. The timekeeper entry box may automatically appear on the professional's computer screen every time the professional is working on a computer based task—LAN document or Internet-based task. The information included in the fields in the timekeeper entry box may either be extracted whereby the invention automatically extracts the information from the document or other task being performed by the professional or can be input by the professional as he or she is performing the document or task. The invention may read the document profile created for each LAN document in order to extract pertinent information for the timekeeper entry box. The billing professional may also manually type in the pertinent information into the timekeeper entry box as the professional is performing that service. In the case of a Internet-based service such as e-mail or research, the system may read certain tagged or designated fields in order to extract pertinent information for the timekeeper entry box. The billing professional may also manually type in the pertinent information into the timekeeper entry box, as the billing professional is performing that service. The time computation feature in the timekeeper entry box will automatically start upon creation of a LAN document by the professional or upon commencement of a Internet-based task such as E-mail or a research session. The time computation function will automatically cease upon closing of the LAN document, upon sending, saving or closing the e-mail, and upon cessation of the research session or other task by closing out of the session. The timekeeper entry box may also include command buttons which the billing professional can use to control the time computation function as well as other functions related to the timekeeper entry box. These command buttons may function to “Pause”, “Erase”, “End”, “Maximize” and “Minimize”, or function to perform any other command necessary for efficient billable timekeeping. For example, if the professional is performing a research session on Lexis/Nexis and is interrupted with a phone call on another matter, the professional can click the Pause button on the timekeeper entry box for the research session. This will pause the time computation function until the billing professional clicks on pause again to restart or resume the time computation function. In another embodiment, the invention may detect a lack of mouse, keyboard and/or other interaction activity, and may automatically pause billing for the task. The invention generates a daily time and billing report for an individual professional which can either be uploaded and viewed on the computer screen or printed for review and/or revision. The report may contain the following information: date, name of billing attorney or billing professional, and for each document generated or task, the client identifier, subject of document or description of task, time expended (start and end time and total time converted into the standard billing increments utilized by the firm or company, such as tenth of an hour or quarter of an hour). The report may also combine time calculations relating to the same document or task (e.g., an individual may work on the same document or task at different times during the same day) in order to generate a cumulative billing entry for that document or task, or may combine time calculations for same client matters or may combine time calculations following other programmed instructions. The invention may also generate a summary report based on any specific subject matter category, or combination of categories selected, or for a particular client. Moreover, the information generated by the report can be entered directly into the firm's or company's existing accounting or billing system used for generating billing invoices for professional services rendered to clients. In another embodiment of the invention, there is a telephone and means operatively associated with the telephone for detecting when the telephone is in use and generating a signal in response to the in use. A CPU is operatively associated with the detecting means and has software associated with the detecting means for enabling the timekeeper entry box to track time and billing information for telephone calls initiated or received by an individual professional on a daily basis. It will be appreciated by those skilled in the art that the foregoing brief description and the following detailed description are exemplary and explanatory of the invention, but are not intended to be restrictive thereof or limiting of the advantages which can be achieved by the invention. Thus, the accompanying drawings, referred to herein and constituting a part hereof, illustrate preferred embodiments of this invention, and, together with the detailed description, serve to explain the principles of this invention. BRIEF DESCRIPTION OF THE DRAWINGS The features and advantages of the present invention, both as to its structure and operation, will be apparent from the following detailed description, especially when taken in conjunction with the accompanying drawings, wherein: FIG. 1 is a block diagram of an embodiment of a computer device that can be used in the invention; FIG. 2 is an exemplary illustration of the software program icon of the invention (labeled “CompuBiller”) among other program icons uploaded on a computer device; FIG. 3 is an exemplary illustration of a computer screen of a Internet-based e-mail document and the timekeeper entry box; FIG. 4 is an exemplary illustration of a computer screen of a LAN-based Microsoft Word document and the timekeeper entry box; FIG. 5 is an exemplary illustration of a timekeeper entry box; FIG. 6 is an exemplary illustration of a timekeeper entry box including fields for inputting pertinent billing information; FIG. 7 is an exemplary illustration of a timekeeper entry box including extracted information pertinent to a billing entry; FIG. 8 is a flow chart illustrating an embodiment of the method for implementing a realtime billing process; FIG. 9 is a flow chart illustrating an embodiment of the method of extracting pertinent billing information for inclusion in the timekeeper entry box; FIG. 10 is an exemplary illustration of the format of a daily report generated by the invention based on a compilation of stored timekeeper entry boxes for an individual professional. DETAILED DESCRIPTION OF THE INVENTION A realtime billable timekeeper program implemented in software or hardware or both is provided to be used by individual service-related professionals, such as attorneys, on a computer, desktop, notebook, palm pilot, handheld or like device to track the billable time spent by an individual professional on a document-by-document, task-by-task basis contemporaneous with the service being performed, for the purpose of generating a daily billing report for such individual. The program may have particular applicability to those professionals who bill clients on an hourly rate basis, particularly where hourly rates vary for each professional. A person skilled in the art will understand that the present invention may be supplemented in various forms of hardware, software, or a combination thereof. In one embodiment, the present invention may be implemented in software as an application program tangibly embodied on a program storage device. The application program may be uploaded to and executed by a computer device comprising any suitable architecture such as that shown in FIG. 1. Turning now to FIG. 1, illustrated thereon are exemplary components of a computer device 100 for use in the invention. The primary component of computer device 100 is processor (CPU) 105, which may be any commonly available microprocessor. Processor 105 may be operatively connected to further exemplary components, such as random access memory (RAM)/read-only memory (ROM) 110, clock 115, input/output devices 120 and memory 125 which, in turn, stores one or more computer programs 130 and databases 135. Processor 105 operates in conjunction with RAM and ROM. The RAM portion of RAM/ROM 110 may be a suitable number of Single In-Line Memory Module (SIMM) chips having a storage capacity (typically measured in kilobytes or megabytes) sufficient to store and transfer, inter alia, processing instructions utilized by processor 105 which may be received by application programs 130. The ROM portion of RAM/ROM 110 may be any permanent non-rewritable memory medium capable of storing and transferring, inter alia, processing instructions performed by processor 105. Clock 115 may be an on-board component of processor 105 which dictates a clock speed (typically measured in MHz) at which processor 105 performs and synchronizes, inter alia, communication between the internal components of computer device 100. Input/output devices 120 may be one or more known devices used for receiving operator inputs, network data, and the like and transmitting outputs resulting therefrom. Accordingly, exemplary input devices may include a keyboard, a mouse, a voice recognition unit and the like for receiving operator inputs. Output devices may include any known devices used to present data to an operator of computer device 100 or to transmit data over Internet 140. Accordingly, suitable output devices may include a display, a printer and a voice synthesizer connected to a speaker. Other input/output devices may include a telephone or network connection device, such as a telephone modem, a cable modem, a T-1 connection, a digital subscriber line or a network card, for communicating data to and from other computer devices over Internet 140. Input/output devices can have capacity to handle high bandwidth traffic in order to accommodate communications with a large number of visitors. Memory 125 may be an internal or external large capacity device for storing computer processing instructions, computer-readable data, and the like. The storage capacity of memory 125 is typically measured in megabytes or gigabytes. Accordingly, memory 125 may be one or more of the following: a floppy disk in conjunction with a floppy disk drive, a hard disk drive, a CD-ROM disk and reader/writer, a DVD disk and reader/writer, a ZIP disk and a ZIP drive, and/or any other computer readable medium that may be encoded with processing instructions in a read-only or read-write format. Further functions of and available devices for memory 125 will be apparent. Memory 125 may store, inter alia, a plurality of programs 130, such as the realtime software billable timekeeper program of the invention. Memory 125 also includes databases 135 comprising multiple blocks of information such as the realtime billing entries of an individual professional on a document-by-document, task-by-task basis and for any given time period, including on a daily basis. The realtime software billable timekeeper program interfaces with any Internet-based or LAN application program that generates a file, e.g., Microsoft Word®, Microsoft Outlook®, Lotus Notes®, Acrobat Reader®, Adobe Illustration®, Adobe Photoshop®, Adobe Acrobat®, TimeKeeper Desktop®, PCTime®, CMS OPEN®, LexisNexis®, WestLaw® and Internet Explorer® and any other program that generates a file. Turning now to FIG. 2, illustrated therein is a computer device 200, here a desktop computer. Visible on the screen of the computer are various icons for program applications, namely Internet Explorer® 210, Lexis® 220, Microsoft Word® 230, My Computer® 240, PC Time® 250 and the software program of the invention, here identified as CompuBiller® 260. Any computer device can be adopted for use in the invention, including, without limitation, desktop, notebook, palm pilot, handheld or like devices. Moreover, the software program of the invention is adaptable for interfacing with any program that generates a file, service or other application for billing purposes. FIG. 3 is an embodiment of Timekeeper Entry Box™ 300 generated by the software program of the invention for interfacing with a Internet-based document, here e-mail 310, generated by a professional. Timekeeper Entry Box™ 300 is generated contemporaneous with the professional's generation of e-mail 310. In this embodiment, Timekeeper Entry Box™ 300 requires a professional to enter Client Identifier 320 and Personal Code 330. Timekeeper Entry Box™ automatically generates Start Time 340, End Time 350 and Total Time 360. Control command buttons Minimize 370, Maximize 380, Pause 385, End 390 and Erase 395 are also configured in Timekeeper Entry Box™ 300. Contemporaneous with the opening of e-mail 310, Timekeeper Entry Box™ 300 is generated and billable Start Time 340 commences. The professional has the ability to control certain aspects of the Timekeeper Entry Box™. Minimize button 370 can be activated, for example by clicking on the button with a pointer directed by a mouse or by any other means known to a person skilled in the art. The Minimize button functions to reduce Timekeeper Entry Box™ so that it does not obstruct the view of the Internet-based document, LAN document, task or other service the professional is working on. Maximize button 380 can be activated to increase the size of the Timekeeper Entry Box™, enabling the professional, for example, to input information into the specified fields on the Timekeeper Entry Box™. Pause button 385 can be activated at any time while the document is open or during the course of the service to pause the running time clock for billing purposes. For example, if a professional is interrupted (e.g., a phone call on another matter) while working on the document, task or service, the professional can click on the Pause button to prevent the client from being billed for time not spent working on the document, task or service. The professional can resume the running time clock upon returning to work on the document, task or service by, for example, reclicking on the Pause button. If the professional prefers to limit the amount of billable time allocated to a particular document, service or task, the professional can also click on the End button 390 while the document, service or task is still in session. The End command will terminate the billable time keeping for that particular document, service or task. Upon termination of the billable session by closing a document, saving a document, sending a document, deleting a document being reviewed, ending a session or task, clicking the End button or by any other means, the program records End Time 350 for the session and Total Time 360. The Timekeeper Entry Box™ closes and the information generated in the box is stored by the program. To the extent a professional does not want to record billable time with respect to a particular document, service or task, the professional can click on Erase button 395. The Erase command functions to delete the Timekeeper Entry Box™ so that no information or time relating to a particular document, task or session is stored. In another embodiment, a professional may be given the option of recording billable time for a particular document, service or task. A precursor request can be configured to appear prior to displaying the Timekeeper Entry Box™, requesting the professional whether the document, service or task should be billed. The professional has the option of billing time to the document, service or task session, whereupon the Timekeeper Entry Box™ is generated, or proceeding without activating the Timekeeper Entry Box™ so that no billable time will be recorded for such session. The software program of the invention can also be configured to apply only to selected documents, services and/or tasks performed by a professional. For example, in the case of attorneys, the software program may only be configured to apply to the legal memoranda generated, edited and/or reviewed by an attorney as well as legal research sessions undertaken on LexisNexis®, WestLaw® or the like but will not be activated for e-mail use. FIG. 4 is an embodiment of Timekeeper Entry Box™ 400 generated contemporaneous with a professional's generation of a Microsoft Word® LAN-based document 410. The invention can be employed with any Internet-based or LAN-based documents or services or tasks performed by a professional using a computer device. Moreover, the invention is applicable to such documents, services or tasks generated, received or reviewed by a professional. FIG. 5 is an exemplary configuration of Timekeeper Entry Box™ 500 that is generated by the software program of the invention contemporaneously with the initiation of any document, service or task using a computer. Timekeeper Entry Box™ 500 may be configured to include any user input information and/or automatically extracted information relating to the document, service or task for the purpose of generating a contemporaneous billable time report for an individual professional. Timekeeper Entry Box™ 500 may also include one or more command functions permitting the user to control aspects of the billable timekeeping mechanism, as well as a favorites function which may include present client matter information for incorporation in the timekeeper entry box. Another feature of the Timekeeper Entry Box™ is the visual aspect of the box to a professional. The fact that the box will appear on a contemporaneous basis with each document, service and/or task performed by the professional will encourage the professional to account for billable time on a contemporaneous basis with services provided. Moreover, the box also provides a visual of billable time tracked by the invention for each document, service and/or task. In this embodiment, Timekeeper Entry Box™500 incorporates the following information: Client Identifier 510, Personal Code 520, Start Time 530, End Time 540, Total Time 550. The client identifier may include any number of letters, numerals and/or other characters to identify a specific client. The personal code may include any number of letters, numerals and/or characters to identify a specific professional individual. The start time may be the time the document, session and/or task commences; the end time may be the time the document, session and/or task concludes; and the total time is the time difference between the start time and the end time. The Timekeeper Entry Box™ may also include a running clock visual to the professional so that the professional is informed of the time spent on a particular service at any moment. Timekeeper Entry Box™ 500 also includes Favorites button 555, Minimize button 560, Maximize button 570, Pause button 580, End button 590 and Erase button 595. Command functions can be configured in any manner in the box and any number of commands may be utilized as suitable to a professional individual. FIGS. 6 and 7 are further embodiments of the Timekeeper Entry Box™. The Timekeeper Entry BOX™ can be configured to require a professional's input of information in each of the fields contained therein, automatically extract information relating to a document, session or task for incorporation into the box and/or require a professional's input for certain information and automatically extract other information for incorporation into the box. In FIG. 6, Timekeeper Entry Box™ 600 requires a professional to input Date 610, Client Identifier 620, Personal Code 630, Document Type 640, document Author(s) 650, document Recipient(s) 660, Detailed Description 670 of document, service or task, Start Time 680, End time 690 and Total Time 695. In FIG. 7, certain information is required to be input by a professional and certain information has been automatically extracted by the software program of the invention for incorporation in Timekeeper Entry Box™ 700. Information to be input are Client Identifier 720 and Personal Code 730. Extracted information are Date 710, Document Type 740, Author(s) 750, Recipient(s) 760, Detailed Description 770 and Start Time 780. In addition, End Time 790 and Total Time 795 will be automatically extracted by the software program upon completion of the document, service or task. FIG. 8 is an embodiment of a flow scheme of the invention. In Step 800, the invention detects that a document is opened or the initiation of a service or task. In Step 805, the invention generates a Timekeeper Entry Box™ contemporaneous with the opening of the document or initiation of service/task. In Step 810, upon opening the timekeeper entry box, the invention automatically starts the time computation corresponding to the specific professional service undertaken by the individual professional. In Step 815, the invention extracts and/or receives input information for incorporation in the timekeeper entry box to define the billable item for the service being performed. In Step 820, the invention detects that the document has been closed, saved and/or sent, or the service/task has been completed or an end command. Upon detecting that the document has been closed, saved or sent, or the service/task has been completed or an end command, the invention ends the time computation, and stores the information generated in the timekeeper entry box in Step 825. Alternatively, during the service being performed, the invention may detect a pause command as in Step 830. Upon detecting a pause command, the invention stops the time computation in Step 835, and upon detecting a resume command 840, the invention resumes the time computation relating to the specific document and/or service/task being performed by the individual professional. In Step 845, the invention may also detect an erase command, upon which the invention ends the process and deletes the timekeeper entry box in Step 850. No information relating to this service is stored by the invention. In addition, prior to generating a timekeeper entry box relating to a particular service, an individual professional may be requested in Step 855 whether the service should be billed and, consequently, a timekeeper entry box should be generated. If the individual professional requests that the service be billed, a timekeeper entry box is generated. If the individual professional chooses not to bill a client for a particular service, the timekeeping session is terminated in Step 860, and no billable time is recorded for this particular service. The software program of the invention further is capable of detecting the service or task being performed by the individual professional and extracting pertinent information relating to each type of search being performed for inclusion in the “Timekeeper Entry Box™”. As such, the pertinent information extracted may differ depending upon the task being performed. FIG. 9 is a flow diagram setting forth the detection/extraction steps undertaken by an embodiment of the invention. In FIG. 9, the invention detects the task being performed by the professional in Step 900. The task may comprise drafting, reviewing or editing a Internet-based document, such as an e-mail, drafting, reviewing or editing a LAN based document, a research session, making or receiving a telephone call or any other billable service undertaken by a professional. Depending upon the type of task detected, e.g., drafting, reviewing or editing an e-mail (Step 905), drafting, reviewing or editing a newly generated LAN document (Step 910), editing an existing LAN document (Step 915), research session (Step 920) or making or receiving a telephone call (Step 925), the invention is configured to extract particular information for inclusion in the “Timekeeper Entry Box™” depending upon the form of the task or service performed. For example, in Step 930, the invention detects a service being performed relating to an e-mail and extracts pertinent information from the e-mail headers or the harddrive or other source relating to the e-mail. The extracted information may be verified and/or used to look up matter identifying data in a database, address book, and/or the like. Such information may be the author(s), recipient(s), subject and/or date of the e-mail. In Step 935, the invention detects a new LAN document being generated by a professional individual and extracts pertinent information from the document's profile or harddrive or other source relating to the newly generated LAN document. In Step 940, the invention detects the editing of an existing LAN document and extracts pertinent information from the document's profile, metadata or harddrive or other source relating to the edited document. In Step 945, the invention detects a research session and extracts a client identifier, professional's code or other pertinent information from the search session. In Step 950, the invention detects a telephone call and extracts a caller ID, client identifier, professional's code, voice recognition information or other pertinent information relating to the telephone call. The extracted information may be verified and/or used to look up matter identifying data in a database, address book, and/or the like. FIG. 10 is an embodiment of “Daily Report” 1000 on Date 1010 for attorney 1020 generated by the invention based on the billable services performed by the attorney. The report that is generated is specific to the attorney's billable services for that date and compiles all information stored from the timekeeper entry boxes generated on that date. As the report shows the information compiled for each billable service or task undertaken by the attorney for that date, includes for Document/Task Description 1030, a Client Identifier 1050, Document Type 1060, Description 1070, and for corresponding Time 1040, a Start/End time 1080 and Total time 1090. The invention can be configured to generate a billable report for an individual professional for any length of time, and can categorize and/or subcategorize the billable time entries in any suitable manner, e.g., by client or service. The invention can also be configured such that the report is transmitted, received and incorporated into any LAN application program that generates a file for billing purposes. Although illustrative preferred embodiments have been described herein in detail, it should be noted and will be appreciated by those skilled in the art that numerous variations may be made within the scope of this invention without departing from the principle of this invention and without sacrificing its chief advantages. The terms and expressions have been used as terms of description and not terms of limitation. There is no intention to use the terms or expressions to exclude any equivalents of features shown and described in portions thereof and this invention should be defined in accordance with the claims which follow. | <SOH> BACKGROUND OF THE INVENTION <EOH>Electronic time and billing and/or cost systems have evolved from the traditional time log manually recorded on blank sheets of paper or on pre-formatted paper forms. Such systems have been in a constant state of flux and evolution since the introduction of computer technology into the professional working environment. Today, virtually one hundred percent of the documents that are generated and stored in professional offices are computer generated. The need for a realtime computer generated time and billing system for the individual professional is thus essential in today's working environment. This is particularly true for attorneys and other service-related professionals who bill clients based on an hourly rate for time spent on a particular matter where hourly rates vary for each professional, and thus, it is essential to record and bill each professional's time on an individual basis. Moreover, in an increasingly cost conscious environment, clients have justifiably mandated strict guidelines and specific support for all time billed down to the minute. This has increased the burden on professionals such as attorneys to keep a running track record of every hour, every minute, of their billable time and to provide adequate justification for such billable time on a daily basis. Many attorneys and other billing professionals do not record time expended for rendering professional services contemporaneous with the task or service performed. This results in time being lost and never billed due to the inability to remember the task performed or the amount of time spent for performing the task. The absence of a computer system which monitors billable time for every document generated and/or task undertaken during the course of a given day contemporaneous with the service being performed has proven to be an insurmountable burden for many professionals who have a difficult time administratively logging their time on a daily basis. Unfortunately, while there have been numerous attempts to improve existing time and billing systems, none have addressed the need for a timekeeping tracking computer system, method and apparatus on a document-by-document, task-by-task, realtime basis for the purpose of generating a daily billing report for an individual service-related professional. For example, U.S. Pat. No. 5,991,742, entitled “Time and Expense Logging System”, is directed to a portable time and billing system for professionals who are constantly on their feet, do not have access to desktop or notebook computers and may not have typing skills or familiarity with operating a computer. The '742 patent is directed to a computer system which accepts data from the user using an input recognizer such as a handwriting recognizer or speech recognizer. Other computer systems are directed to overall billkeeping or litigation management or cost budgeting. U.S. Pat. No. 6,622,128, entitled “Internet-based attorney-client billing system” is directed to an Internet-based billkeeping and litigation management system, allowing third parties to monitor the progress and expense of litigation and/or possibly other legal matters. U.S. Patent Application Publication No. 20030225989, entitled “System for calculating billable time” is directed to a timing system for tracking the time spent on a client file for cost budget purposes. The timing system does not address the tracking of billable time for an individual professional on a document-by-document, task-by-task, realtime basis for the purpose of generating a daily billing report for that individual professional. The timing system also is not directed to monitoring each newly generated document, whether Internet-based or LAN based, or task of an individual professional on a daily basis. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention relates to a timekeeping and tracking computer method, system and apparatus on a document-by-document, task-by-task, realtime basis for the purpose of generating a daily billing report for an individual services-related professional. The manner by which the computer method, system and apparatus may generate, track and record time may be through the use of a software program that generates a timekeeper entry box each time a document or task is being performed by the professional. The timekeeper entry box may appear on the professional's computer screen for each document, task or other service (LAN or Internet-based) performed by the professional. The timekeeper entry box may include a field for entry of a client identifier (client name or billing number). The timekeeper entry box may also include additional fields for entry of information, such as date, document type, description of task being performed and billing professional identifier. The timekeeper entry box may automatically appear on the professional's computer screen every time the professional is working on a computer based task—LAN document or Internet-based task. The information included in the fields in the timekeeper entry box may either be extracted whereby the invention automatically extracts the information from the document or other task being performed by the professional or can be input by the professional as he or she is performing the document or task. The invention may read the document profile created for each LAN document in order to extract pertinent information for the timekeeper entry box. The billing professional may also manually type in the pertinent information into the timekeeper entry box as the professional is performing that service. In the case of a Internet-based service such as e-mail or research, the system may read certain tagged or designated fields in order to extract pertinent information for the timekeeper entry box. The billing professional may also manually type in the pertinent information into the timekeeper entry box, as the billing professional is performing that service. The time computation feature in the timekeeper entry box will automatically start upon creation of a LAN document by the professional or upon commencement of a Internet-based task such as E-mail or a research session. The time computation function will automatically cease upon closing of the LAN document, upon sending, saving or closing the e-mail, and upon cessation of the research session or other task by closing out of the session. The timekeeper entry box may also include command buttons which the billing professional can use to control the time computation function as well as other functions related to the timekeeper entry box. These command buttons may function to “Pause”, “Erase”, “End”, “Maximize” and “Minimize”, or function to perform any other command necessary for efficient billable timekeeping. For example, if the professional is performing a research session on Lexis/Nexis and is interrupted with a phone call on another matter, the professional can click the Pause button on the timekeeper entry box for the research session. This will pause the time computation function until the billing professional clicks on pause again to restart or resume the time computation function. In another embodiment, the invention may detect a lack of mouse, keyboard and/or other interaction activity, and may automatically pause billing for the task. The invention generates a daily time and billing report for an individual professional which can either be uploaded and viewed on the computer screen or printed for review and/or revision. The report may contain the following information: date, name of billing attorney or billing professional, and for each document generated or task, the client identifier, subject of document or description of task, time expended (start and end time and total time converted into the standard billing increments utilized by the firm or company, such as tenth of an hour or quarter of an hour). The report may also combine time calculations relating to the same document or task (e.g., an individual may work on the same document or task at different times during the same day) in order to generate a cumulative billing entry for that document or task, or may combine time calculations for same client matters or may combine time calculations following other programmed instructions. The invention may also generate a summary report based on any specific subject matter category, or combination of categories selected, or for a particular client. Moreover, the information generated by the report can be entered directly into the firm's or company's existing accounting or billing system used for generating billing invoices for professional services rendered to clients. In another embodiment of the invention, there is a telephone and means operatively associated with the telephone for detecting when the telephone is in use and generating a signal in response to the in use. A CPU is operatively associated with the detecting means and has software associated with the detecting means for enabling the timekeeper entry box to track time and billing information for telephone calls initiated or received by an individual professional on a daily basis. It will be appreciated by those skilled in the art that the foregoing brief description and the following detailed description are exemplary and explanatory of the invention, but are not intended to be restrictive thereof or limiting of the advantages which can be achieved by the invention. Thus, the accompanying drawings, referred to herein and constituting a part hereof, illustrate preferred embodiments of this invention, and, together with the detailed description, serve to explain the principles of this invention. | 20040225 | 20120724 | 20050825 | 96467.0 | 1 | IWARERE, OLUSEYE | REALTIME BILLABLE TIMEKEEPER METHOD, SYSTEM AND APPARATUS | SMALL | 0 | ACCEPTED | 2,004 |
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10,787,644 | ACCEPTED | Methods and systems for automatically tracking information during flight | Methods and systems for automatically tracking information during flight are disclosed. A method in accordance with one embodiment of the invention includes receiving first information corresponding to a proposed aspect of a flight of the aircraft and including at least one target value. The method can further include automatically receiving second information that includes an actual value corresponding to the at least one target value, as the aircraft executes the flight. The at least one target value and the actual value can be provided together in a common computer-based medium. | 1. A computer-implemented method for collecting aircraft flight data, comprising: receiving first information corresponding to a proposed aspect of a flight of the aircraft, the first information including at least one target value; as the aircraft executes the flight, automatically receiving second information that includes an actual value corresponding to the at least one target value; and providing the at least one target value and the actual value together in a common computer-based medium. 2. The method of claim 1 wherein providing the at least one target value and the actual value includes providing the at least one target value and the actual value in a printable electronic file. 3. The method of claim 1 wherein providing the at least one target value and the actual value includes providing the at least one target value and the actual value in a printout. 4. The method of claim 1 wherein providing the at least one target value and the actual value includes providing the at least one target value and the actual value in a computer-displayable file. 5. The method of claim 1 wherein providing the at least one target value and the actual value includes providing the at least one target value and the actual value to an aircraft flight data recorder. 6. The method of claim 1 wherein providing the at least one target value and the actual value includes providing the at least one target value and the actual value to a ground facility via a data link. 7. The method of claim 1 wherein providing the at least one target value and the actual value includes providing a graphical representation of the at least one target value and the actual value. 8. The method of claim 1 wherein providing the at least one target value and the actual value includes providing an alphanumeric representation of the at least one target value and the actual value in a tabular format. 9. The method of claim 1 wherein providing the at least one target value and the actual value includes storing the at least one target value and the actual value on a computer-readable medium. 10. The method of claim 1, further comprising displaying the at least one target value and the actual value simultaneously. 11. The method of claim 1 wherein receiving the first information includes receiving information including at least one of a target altitude, target airspeed, target time, target heading, target fuel consumption and target location. 12. The method of claim 1 wherein receiving the first information includes automatically receiving information uplinked from air traffic control. 13. The method of claim 1 wherein receiving the first information includes receiving information input by an operator of the aircraft via an input device. 14. The method of claim 1 wherein receiving the first information includes receiving information included as part of an aircraft flight plan. 15. The method of claim 1 wherein the target includes a target location on a target path, and wherein the method further comprises automatically receiving the second information when the aircraft intersects a line passing through the target location and oriented at least approximately perpendicular to an actual path. 16. The method of claim 1, further comprising: displaying the target value in a first manner; and displaying the actual value in a second manner different than the first manner. 17. The method of claim 1 wherein the target value includes a target distribution of fuel usage as a function of distance traveled by the aircraft and wherein the actual value includes an actual distribution of fuel usage as a function of distance traveled by the aircraft, and wherein the method further comprises displaying the target distribution and the actual distribution graphically. 18. The method of claim 1, further comprising: receiving third information corresponding to an aspect of the flight, the third information being input by an operator of the aircraft; and providing the third information along with the target value and the actual value in the common medium. 19. A computer-implemented method for collecting aircraft flight data, comprising: receiving first information corresponding to a proposed flight plan, the first information including a plurality of targets to which an aircraft may be directed during flight, the plurality of targets having corresponding target values; as the aircraft executes the flight, automatically receiving second information that includes actual values corresponding to the target values; and providing the target values and the actual values together in a common computer-based medium to an operator of the aircraft. 20. The method of claim 19 wherein providing the target values and the actual values includes: providing the target values and the actual values at a single display of the aircraft; and providing the target values and the actual values in a printable electronic file. 21. The method of claim 19 wherein providing the target values and the actual values includes providing a graphical representation of the target values and the actual values. 22. The method of claim 19 wherein receiving the first information includes receiving information including at least one of a target altitude, target airspeed, target time, target heading, target fuel consumption and target location. 23. The method of claim 19 wherein the target includes a target location on a target path, and wherein the method further comprises automatically receiving the second information when the aircraft intersects at a right angle a line passing through the target location. 24. The method of claim 19, further comprising: displaying the target value in a first manner; and displaying the actual value in a second manner different than the first manner. 25. The method of claim 19 wherein the target value includes a target distribution of fuel usage as a function of distance traveled by the aircraft and wherein the actual value includes an actual distribution of fuel usage as a function of distance traveled by the aircraft, and wherein the method further comprises displaying the target distribution and the actual distribution graphically. 26. The method of claim 19, further comprising: receiving third information corresponding to an aspect of the flight, the third information being input by an operator of the aircraft; and providing the third information along with the target value and the actual value in the common medium. 27. A system for collecting aircraft flight data, comprising: a first receiving portion configured to receive first information corresponding to a proposed aspect of a flight of the aircraft, the first information including at least one target value; a second receiving portion configured to automatically receive second information as the aircraft executes the flight, the second information including an actual value corresponding to the at least one target value; and an assembly portion configured to provide the target value and the actual value together in a common computer-based medium. 28. The system of claim 27 wherein the first receiving portion includes a link to an aircraft flight guidance computer. 29. The system of claim 27 wherein the second receiving portion includes a link to aircraft sensors. 30. The system of claim 27 wherein the assembly portion is configured to provide the at least one target value and the actual value in a printable electronic file. 31. The system of claim 27, further comprising a printer coupled to the assembly portion to provide a printout of the at least one target value and the actual value. 32. The system of claim 27 wherein the first receiving portion, the second receiving portion and the assembly portion include computer readable media. 33. The system of claim 27, further comprising a graphical user interface coupled to the assembly portion to provide a graphical representation of the at least one target value and the actual value. 34. The system of claim 27 wherein the first receiving portion is configured to receive information including at least one of a target altitude, target airspeed, target time, target heading, target fuel consumption and target location, and wherein the second receiving portion is configured to receive information including at least one of an actual altitude, actual airspeed, actual time, actual heading, actual fuel consumption and actual location. 35. The system of claim 27, further comprising a display device coupled to the assembly portion to display the at least one target value in a first manner and display the actual value in a second manner different than the first manner. 36. The system of claim 27 wherein the at least one target value includes a target distribution of fuel usage as a function of distance traveled by the aircraft and wherein the actual value includes an actual distribution of fuel usage as a function of distance traveled by the aircraft, and wherein the system further comprises a graphical user interface coupled to the assembly portion to display the target distribution and the actual distribution graphically. 37. The system of claim 27, further comprising a third receiving portion coupled to the assembly portion and configured to receive third information corresponding to an aspect of the flight, the third information being input by an operator of the aircraft and wherein the assembly portion is configured to provide the third information along with the at least one target value and the actual value in the common computer-based medium. 38. A system for collecting aircraft flight data, comprising: first receiving means configured to receive first information corresponding to a proposed aspect of a flight of the aircraft, the first information including at least one target value; second receiving means configured to automatically receive second information as the aircraft executes the flight, the second information including an actual value corresponding to the at least one target value; and assembly means configured to provide the target value and the actual value together in a common computer-based medium. 39. The system of claim 38 wherein the first receiving means, the second receiving means and the third receiving means include portions of one or more computer processors. 40. The system of claim 38, further comprising output means for outputting the target value and the actual value, the output means being operatively coupled to the assembly means. | TECHNICAL FIELD The present invention relates generally to methods and systems for automatically tracking information, including navigational information, fuel consumption data, flight plan data and/or system check data during aircraft flight operations. BACKGROUND Since the advent of organized flight operations, pilots have been required to maintain an historical record of the significant events occurring during their flights. In the earliest days of organized flight, pilots accomplished this task by writing notes by hand on pieces of paper. Still later, this informal arrangement was replaced with a multiplicity of forms, which the pilot filled out during and after flight. Eventually, the preflight portion of this activity became computerized. For example, computers are currently used to generate preflight and flight planning data in standardized forms. Pilots print out the forms and, for each predicted item of flight data, manually enter a corresponding actual item of flight data. For example, the forms can include predicted arrival and departure times, predicted fuel consumption, and predicted times for overflying waypoints en route. These forms are typically maintained for a minimum of 90 days, at the request of regulatory agencies and/or airlines. One characteristic of the foregoing approach is that it requires the pilot to manually input “as-flown” data for many parameters identified in a typical flight plan. As a result, the pilot's workload is increased and the pilot's attention may be diverted from more important or equally important tasks. A drawback with this arrangement is that it may not make efficient use of the pilot's limited time. SUMMARY The present invention is directed to methods and systems for collecting aircraft flight data. A method in accordance with one aspect of the invention can include receiving first information corresponding to a proposed aspect of a flight of the aircraft, with the first information including at least one target value. The method can further include automatically receiving second information that includes an actual value corresponding to the at least one target value, as the aircraft executes the flight. The at least one target value and the actual value can be provided together in a common computer-based medium. For example, the at least one target value and the actual value can be provided in a printable electronic file, a printout, a computer-displayable file, a graphical representation, or via a data link. A system in accordance with an embodiment of the invention can include a first receiving portion configured to receive first information corresponding to a proposed aspect of a flight of the aircraft, the first information including at least one target value. A second receiving portion can be configured to automatically receive second information as the aircraft executes the flight, with the second information including an actual value corresponding to the at least one target value. An assembly portion can be configured to provide the target value and the actual value together in a common computer-based medium. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram illustrating a process for receiving and processing information in accordance with an embodiment of the invention. FIG. 2 is a schematic illustration of a system for receiving and processing flight information in accordance with an embodiment of the invention. FIG. 3 is a block diagram of an embodiment of the system shown in FIG. 2. FIG. 4 is an illustration of a flight plan table having predicted data in accordance with an embodiment of the invention. FIG. 5 is an illustration of a flight plan table having predicted data and actual flight data in accordance with an embodiment of the invention. FIG. 6 is a schematic illustration of a method for determining actual flight data corresponding to predicted flight plan data in accordance with an embodiment of the invention. FIG. 7 is an illustration of a graph comparing actual fuel usage with predicted fuel usage in accordance with an embodiment of the invention. FIG. 8 is an illustration of a table that includes altimeter calibration data in accordance with an embodiment of the invention. FIG. 9 is an illustration of a table that includes information input by a flight crew in accordance with an embodiment of the invention. FIG. 10 illustrates a list of parameters that can be tracked using systems and methods in accordance with embodiments of the invention. FIG. 11 illustrates a flight deck having systems and displays for carrying out methods in accordance with an embodiment of the invention. FIG. 12 illustrates a system for obtaining input from an operator in accordance with an embodiment of the invention. DETAILED DESCRIPTION The following disclosure describes systems and methods for receiving information proposed for an aircraft flight (e.g., flight plan information) and providing this information along with actual, “as flown” data together in a common medium. Certain specific details are set forth in the following description and in FIGS. 1-12 to provide a thorough understanding of various embodiments of the invention. Well-known structures, systems and methods often associated with these aircraft systems have not been shown or described in detail to avoid unnecessarily obscuring the description of the various embodiments of the invention. Those of ordinary skill in the relevant art will understand that additional embodiments of the present invention may be practiced without several of the details described below. Many embodiments of the invention described below may take the form of computer-executable instructions, including routines executed by a programmable computer (e.g., a flight guidance computer or a computer linked to a flight guidance computer). Those skilled in the relevant art will appreciate that the invention can be practiced with other computer system configurations as well. The invention can be embodied in a special-purpose computer or data processor that is specifically programmed, configured or constructed to perform one or more of the computer-executable instructions described below. Accordingly, the term “computer” as generally used herein refers to any data processor and includes Internet appliances, hand-held devices (including palm-top computers, wearable computers, cellular or mobile phones, multi-processor systems, processor-based or programmable consumer electronics, network computers, minicomputers and the like). The invention can also be practiced in distributed computing environments, where tasks or modules are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules or subroutines may be located in both local and remote memory storage devices. Aspects of the invention described below may be stored or distributed on computer-readable media, including magnetic and optically readable and removable computer disks, as well as distributed electronically over networks. Data structures and transmissions of data particular to aspects of the invention are also encompassed within the scope of the invention. FIG. 1 is a block diagram illustrating a process 100 for assembling, correlating and presenting information in accordance with an embodiment of the invention. In one aspect of this embodiment, the process 100 includes receiving first information corresponding to a proposed aspect of a flight of an aircraft (process portion 102). The first information can include at least one predicted target value. For example, the first information can include a description of one or more legs of a flight plan, with the target including a destination airport or a waypoint en route to the destination airport. The target for a destination airport can include an identification of the airport, the airport runway, and/or an estimated touchdown time. The target for a waypoint can include a longitude, latitude, altitude and/or estimated arrival time. The flight of the aircraft can encompass aircraft operations prior to takeoff (e.g., outbound taxi maneuvers) and after landing (e.g., inbound taxi maneuvers). In process portion 104, the process 100 includes automatically receiving second information as the aircraft executes the flight. The second information can include an actual value corresponding to the at least one predicted target value. For example, if the target value includes the latitude, longitude and altitude of a particular waypoint, along with a target time for passing the waypoint, the second information can include the actual latitude, longitude and altitude of the aircraft at its closest approach to the waypoint, along with the time at which the closest approach occurred. The second information can be automatically received, for example, from the aircraft system that generates the second information. In process portion 106, the at least one target value and the actual value can be provided together in a common, computer-based medium. For example, the first information and the second information can be provided in a computer-readable file or a computer-generated printout. As a result, the operator of the aircraft need not manually input actual flight data corresponding to the predicted flight data. Instead, this information can be automatically provided along with the predicted flight data, which can reduce the operator's workload. FIG. 2 is a schematic illustration of a system 210 configured to carry out processes including the process 100 described above. In one aspect of an embodiment shown in FIG. 2, the system 210 includes a processor 211 that receives predicted an actual inputs from input devices 212 and distributes assembled output to output devices 213. For example, the processor can receive the first (e.g., predicted) information described above with reference to FIG. 1 from a flight guidance computer 230 or other computers and systems 240. The flight guidance computer 230 can receive information from other computers, (e.g., with a ground-based data link provided by a dispatcher or air traffic control) or from the operator. The processor 211 can receive the second (e.g., actual) information described above from sensors 250 (via a navigation system 290 and/or the other systems 240), and/or directly from an operator via a keyboard 214 or other input device. The processor 211 can assemble the information and provide the assembled information for access by the operator and/or other personnel associated with aircraft operations. For example, the processor 211 can display the information on a display unit 216, print the information on a printer 215, store the information on computer-readable media and/or direct the information to another system. Further aspects of these operations are described below with reference to FIGS. 3-12. Referring now to FIG. 3, the system 210 can be carried by an aircraft 323 and can include one or more information receivers 317 (three are shown in FIG. 3 as a first receiver 317a, a second receiver 317b and a third receiver 317c) for receiving the predicted and actual information. In other embodiments, the processor 211 (FIG. 2) or other portions of the system 210 can include more receivers (for example, if the functions provided by the receivers are further divided) or fewer receivers (for example, if the functions are consolidated). In a particular aspect of an embodiment shown in FIG. 3, the first receiver 317a can receive first (e.g., predicted) information from a pre-formatted flight plan list 331, which can be generated by and/or reside on the flight guidance computer 230. The second receiver 317b can receive second (e.g., actual) information from the navigation system 290, the other systems 240, and/or directly from an operator via an operator entry device 312. The third receiver 317c can receive third information (e.g., actual flight information that does not necessarily correspond to predicted values) from the other systems 240 and/or the operator. In any of these embodiments, the receiver(s) 317 can include computer-based routines that can access and retrieve the predicted and actual data. An assembler 318 can assemble some or all of the information obtained by the receivers 317 and provide the assembled information to output devices. For example, the assembler 318 can provide information to the operator display 216 (for operator access) and/or to a flight data recorder 319 for access by investigators or other personnel in the event of an aircraft mishap. The assembled information can also be stored on an onboard storage device 320, for example, as file structured data or non-file structured data on a magnetic or optical computer-readable medium. The information stored on the computer-readable medium can be printed onboard the aircraft with an onboard printer 315, and/or the information can be printed off-board the aircraft. Some or all of the foregoing output devices can be housed in a flight deck 360 of the aircraft 323. In still another embodiment, the information can be routed to a communications transmitter 321 and directed offboard the aircraft, for example, to a ground-based receiver 322. The information received at the ground-based receiver 322 can then be routed to an appropriate end destination, for example, an airline or regulatory agency. At least some of the second (e.g., actual) information described above can be obtained and provided to the receivers 317 automatically. Accordingly, the aircraft sensors 250 can detect information during the operation of the aircraft and provide this information for comparison to predicted data. In a particular aspect of this embodiment, the sensors 250 can include navigation sensors 351 (for example, gyroscopes and GPS sensors that determine the location and speed of the aircraft), chronometers (that determine the time elapsed between points along the aircraft's route), compasses (that determine the aircraft's heading), and/or altimeters (that determine the aircraft's altitude). Fuel sensors 352 can determine the amount of fuel onboard the aircraft and/or the rate at which the fuel is being consumed. Other sensors 353 can be used to detect other characteristics of the aircraft during operation, for example, the weight of the aircraft and the outside air temperature. In some embodiments, some of the second information can be provided to the processor 211 by the operator via the operator entry device 312, as described in greater detail below with reference to FIG. 9. In still further embodiments, the operator can use the operator entry device 312 to authorize the operation of the processor 211 at selected points during the flight. In still further embodiments, the operator entry device 312 can be used to provide not only the second information but also the first information. For example, the operator entry device 312 can be used to update the flight plan list 331 and/or other aspects of the aircraft's proposed flight. FIG. 4 is an illustration of a flight plan list 331 configured in accordance with an embodiment of the invention, prior to execution of a flight. In one aspect of this embodiment, the flight plan list 331 can include an airport list 432a and an en route list 432b. The airport list 432a can include the identification of the departure airport, destination airport, and alternate destination airport. The airport list 432a can also list projected or forecast (identified as “FCST”) gate, departure time, lift-off time, touchdown time and gate arrival time. Corresponding actual data (identified as “ACT”) are described below with reference to FIG. 5. The en route list 432b can include a vertical listing of waypoints (“WPT”) and corresponding frequency (“FRQ”), e.g., for corresponding VOR frequencies. For each waypoint, the en route list 432b can include predicted values for flight level altitude (“FL”), tropopause (“TRO”), temperature (“T”), deviation in temperature from a standard day temperature (“TDV”), wind direction and speed (“WIND”), and the component of the wind that is either a headwind or a tailwind (“COMP”). Additional variables can include the true airspeed (“TAS”), ground speed (“GS”), course (“CRS”), heading (“HDG”), airway designation (“ARWY”), minimum safe altitude (“MSA”), distance from previous waypoint (“DIS”), distance remaining in the flight (“DISR”), estimated time en route from previous waypoint (“ETE”), actual time en route from previous waypoint (“ATE”), estimated time of arrival (“ETA”), actual time of arrival (“ATA”), deviation between estimated and actual times (“±”), fuel used from previous waypoint (“ZFU”), estimated fuel remaining at a waypoint (“EFR”), fuel flow per engine per hour (“FFE”), actual fuel remaining (“AFR”), and deviation between estimated fuel remaining and actual fuel remaining (“±”). As described above with reference to the airport list 432a, the en route list 432b can include space for actual values of at least some of the foregoing variables. FIG. 5 illustrates the flight plan list 331, including the airport list 432a and the en route list 432b after completion of a flight. In particular aspect of this embodiment, the predicted values are identified in the flight plan list 331 in a first manner and the actual values are identified in a second manner. For example, the predicted values can be indicated in regular type and the actual values indicated in bold type. In other embodiments, the differences between the predicted and actual data can be highlighted by other methods, for example, by using different colors or different font sizes. In any of these embodiments, the actual flight data can be recorded on both the airport list 432a and the en route list 432b automatically, without the operator manually generating this information. FIG. 6 is a plan view of an aircraft flight route, including a departure point 691, a destination point 695, a proposed flight path 693a and an actual flight path 693b. The proposed flight path 693a passes through two waypoint targets 692a, while the actual flight path 693b passes through two actual waypoints 692b. In one aspect of this embodiment, the actual waypoints 692b represent the points along the actual flight path 693b that are closest to the waypoint targets 692a. Accordingly, each actual waypoint 692b can be determined by locating the intersection of a line passing normal to the actual flight path 693b and through the corresponding waypoint target 692a. In other embodiments, the actual waypoints 692b can be determined by other methods. In any of these embodiments, determining the actual waypoint can provide a way for the operator to easily compare the as-flown route with the predicted route. In one aspect of the embodiments described above, the predicted and actual flight data are presented in tabular format as alphanumeric characters. In other embodiments, these data can be displayed graphically. For example, referring now to FIG. 7, the system 210 described above can generate a fuel consumption graph 770 that compares the actual fuel usage of the aircraft with one or more predicted schedules, both as a function of distance traveled by the aircraft. In a particular embodiment, the fuel consumption graph 770 can include a line 771 corresponding to the predicted fuel usage (assuming the aircraft arrives at its destination with no fuel), and/or a line 772 corresponding to the foregoing predicted fuel usage, plus a reserve. Line 773 identifies the actual fuel used by the aircraft. In one embodiment, the fuel consumption graph 770 can be generated and displayed to the operator en route and/or at the conclusion of the aircraft's flight. One feature of an embodiment of the arrangement described above with reference to FIG. 7 is that the operator need not manually plot the actual fuel used during flight, and can instead rely on the system 210 (FIG. 2) to do so. An advantage of this feature is that it can reduce the operator's workload. Another advantage of this feature is that it can allow the operator to more easily identify a fault with the fuel system (should one exist), for example, if the actual fuel usage is significantly higher or lower than predicted. A further advantage of the foregoing feature, in particular, in combination with the actual waypoint calculation feature described above with reference to FIG. 6, is that the operator can easily determine what the aircraft's fuel consumption performance is, even if the aircraft does not follow the proposed flight path. For example, referring now to FIGS. 6 and 7 together, if the aircraft receives a direct clearance between the departure point 691 and the destination point 695, the system 210 can determine the actual fuel used at each actual waypoint 692b even though the aircraft may be quite distant from the waypoint targets 692a. This information can be obtained and made available to the operator quickly and accurately, without increasing the operator's workload. Accordingly, the operator can more accurately track the fuel usage of the aircraft. This information can be particularly important when determining (a) which airports are within range in case of an in-flight emergency, (b) which airports the aircraft can be rerouted to if ground conditions do not permit landing at the target destination airport, and/or (c) whether a more direct routing can allow the aircraft to skip a scheduled fuel stop. In other embodiments, the system 210 can collect data corresponding to other aspects of the aircraft's operation. For example, referring now to FIG. 8, the system 210 can generate an altimeter calibration list 880 that identifies altimeter calibration data at a variety of points en route, for example, at waypoints or other locations. In other embodiments, other mandatory and/or operator selected calibration or equipment check data can be tracked automatically by the system 210. In still further embodiments, the system 210 can be used by the operator to track information that the operator inputs manually. For example, as shown in FIG. 9, the system can generate a flight event list 980 that includes entries 981 made by the operator and corresponding to data that may have no connection with either preplanned, predicted flight information or equipment calibration. Such information can include passenger specific information, connecting flight information, clearance information and other information selectively deemed by the operator to be pertinent, or required by the airline or regulator to be tracked. FIG. 10 illustrates a sample, non-exhaustive and non-limiting list of variables 1082, many of which have been described above and any or all of which can be tracked by the system 210 described above. In some embodiments, some or all of these items can be selected by an operator to be tracked by the system 210. In other embodiments, the operator can selectively identify other variables for tracking. FIG. 11 is a partially schematic, forward looking view of the flight deck 360 described above with reference to FIG. 3, which provides an environment in which the data described above are received and optionally displayed in accordance with an embodiment of the invention. The flight deck 360 can include forward windows 1161 providing a forward field of view out of the aircraft 323 for operators seated in a first seat 1167a and/or a second seat 1167b. In other embodiments, the forward windows 1161 can be replaced with one or more external vision screens that include a visual display of the forward field of view out of the aircraft 323. A glare shield 1162 can be positioned adjacent to the forward windows 1161 to reduce the glare on one or more flight instruments 1163 positioned on a control pedestal 1166 and a forward instrument panel 1164. The flight instruments 1163 can include primary flight displays (PFDs) 1165 that provide the operators with actual flight parameter information. The flight deck 360 can also include multifunction displays (MFDs) 1169 which can in turn include navigation displays 1139 and/or displays of other information, for example, the completed flight plan list described above with reference to FIG. 5. The flight plan list can also be displayed at one or more control display units (CDUs) 1133 positioned on the control pedestal 1166. Accordingly, the CDUs 1133 can include flight plan list displays 1128 for displaying information corresponding to upcoming (and optionally, completed) segments of the aircraft flight plan. The CDUs 1133 can be operated by a flight management computer 1129 which can also include input devices 1127 for entering information corresponding to the flight plan segments. The flight instruments 1163 can also include a mode control panel 1134 having input devices 1135 for receiving inputs from the operators, and a plurality of displays 1136 for providing flight control information to the operators. The operators can select the type of information displayed at least some of the displays (e.g., the MFDs 1169) by manipulating a display select panel 1168. In other embodiments, the information can be displayed and/or stored on a laptop computer 1141 coupled to the flight instruments 1163. Accordingly, the operator can easily download the information to the laptop computer 1141 and remove it from the aircraft after flight. In another embodiment, the data can be automatically downloaded via the data communications transmitter 321 (FIG. 3) or stored on a removable medium, including a magnetic medium and/or an optically scannable medium. FIG. 12 illustrates one of the CDUs 1133 described above. The CDU can include input devices 1127, such as a QWERTY keyboard for entering data into a scratchpad area 1137. The data can be transferred to another display (e.g., an MFD 1169) or other device by highlighting a destination field 1138 via a cursor control device 1139 (for example, a computer mouse) and activating the cursor control device 1139. In other embodiments, the operator can input information in other manners and/or via other devices. One feature of the embodiments described above with reference to FIGS. 1-12 is that information that had previously been manually input by the operator of the aircraft (for example, actual, as flown flight data) is instead generated, assembled, and/or provided automatically by an aircraft system. An advantage of this arrangement is that it can reduce operator workload, thereby freeing the operator to spend his or her limited time on potentially more pressing aspects of the aircraft's operation. Accordingly, the overall efficiency with which the operator completes his or her tasks, and/or the accuracy with which such tasks can be improved. From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the invention. For example, aspects of the invention described above in the context of particular embodiments can be combined, re-arranged or eliminated in other embodiments. Accordingly, the invention is not limited except as by the appended claims. | <SOH> BACKGROUND <EOH>Since the advent of organized flight operations, pilots have been required to maintain an historical record of the significant events occurring during their flights. In the earliest days of organized flight, pilots accomplished this task by writing notes by hand on pieces of paper. Still later, this informal arrangement was replaced with a multiplicity of forms, which the pilot filled out during and after flight. Eventually, the preflight portion of this activity became computerized. For example, computers are currently used to generate preflight and flight planning data in standardized forms. Pilots print out the forms and, for each predicted item of flight data, manually enter a corresponding actual item of flight data. For example, the forms can include predicted arrival and departure times, predicted fuel consumption, and predicted times for overflying waypoints en route. These forms are typically maintained for a minimum of 90 days, at the request of regulatory agencies and/or airlines. One characteristic of the foregoing approach is that it requires the pilot to manually input “as-flown” data for many parameters identified in a typical flight plan. As a result, the pilot's workload is increased and the pilot's attention may be diverted from more important or equally important tasks. A drawback with this arrangement is that it may not make efficient use of the pilot's limited time. | <SOH> SUMMARY <EOH>The present invention is directed to methods and systems for collecting aircraft flight data. A method in accordance with one aspect of the invention can include receiving first information corresponding to a proposed aspect of a flight of the aircraft, with the first information including at least one target value. The method can further include automatically receiving second information that includes an actual value corresponding to the at least one target value, as the aircraft executes the flight. The at least one target value and the actual value can be provided together in a common computer-based medium. For example, the at least one target value and the actual value can be provided in a printable electronic file, a printout, a computer-displayable file, a graphical representation, or via a data link. A system in accordance with an embodiment of the invention can include a first receiving portion configured to receive first information corresponding to a proposed aspect of a flight of the aircraft, the first information including at least one target value. A second receiving portion can be configured to automatically receive second information as the aircraft executes the flight, with the second information including an actual value corresponding to the at least one target value. An assembly portion can be configured to provide the target value and the actual value together in a common computer-based medium. | 20040226 | 20090818 | 20050901 | 93970.0 | 0 | TO, TUAN C | METHODS AND SYSTEMS FOR AUTOMATICALLY TRACKING INFORMATION DURING FLIGHT | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,787,663 | ACCEPTED | Rendering GUI widgets with generic look and feel | Rendering GUI widgets with generic look and feel by receiving in a display device a master definition of a graphics display, the master definition including at least one graphics definition element, the graphics definition element including a reference to a protowidget and one or more instance parameter values characterizing an instance of the protowidget, the protowidget includes a definition of a generic GUI object, including generic display values affecting overall look and feel of the graphics display, and rendering at least one instance of the protowidget to a graphics display in dependence upon the generic display values and the instance parameter values. | 1. A method for rendering a GUI widget with a generic look and feel, the method comprising: receiving in a display device a master definition of a graphics display, the master definition including at least one graphics definition element, the graphics definition element comprising a reference to a protowidget and one or more instance parameter values characterizing an instance of the protowidget, the protowidget comprising a definition of a generic GUI object, including generic display values affecting overall look and feel of the graphics display; and rendering at least one instance of the protowidget to a graphics display in dependence upon the generic display values and the instance parameter values. 2. The method of claim 1 wherein rendering at least one instance of the protowidget further comprises inserting in the instance of the protowidget the instance parameter values from the master definition. 3. The method of claim 1 wherein rendering at least one instance of the protowidget further comprises creating instance display values for the instance of the protowidget in dependence upon the instance parameter values. 4. The method of claim 3 wherein: the protowidget further comprises at least one generic display rule, and creating instance display values for the instance of the protowidget further comprises creating instance display values for the instance of the protowidget in dependence upon the generic display rule. 5. The method of claim 1 further comprising creating the protowidget. 6. The method of claim 5 wherein creating the protowidget further comprises defining the protowidget in a scalable vector graphics language. 7. The method of claim 1 further comprising creating the master definition of a graphics display. 8. The method of claim 1 wherein rendering at least one instance of the protowidget further comprises creating in computer memory a data structure comprising an instance of the protowidget. 9. The method of claim 8 wherein the data structure comprising an instance of the protowidget further comprises a DOM. 10. A system for rendering a GUI widget with a generic look and feel, the system comprising: means for receiving in a display device a master definition of a graphics display, the master definition including at least one graphics definition element, the graphics definition element comprising a reference to a protowidget and one or more instance parameter values means for characterizing an instance of the protowidget, the protowidget comprising a definition of a generic GUI object, including generic display values affecting overall look and feel of the graphics display; and means for rendering at least one instance of the protowidget to a graphics display in dependence upon the generic display values and the instance parameter values. 11. The system of claim 10 wherein means for rendering at least one instance of the protowidget further comprises means for inserting in the instance of the protowidget the instance parameter values from the master definition. 12. The system of claim 10 wherein means for rendering at least one instance of the protowidget further comprises means for creating instance display values for the instance of the protowidget in dependence upon the instance parameter values. 13. The system of claim 12 wherein: the protowidget further comprises at least one generic display rule, and means for creating instance display values for the instance of the protowidget further comprises means for creating instance display values for the instance of the protowidget in dependence upon the generic display rule. 14. The system of claim 10 further comprising means for creating the protowidget. 15. The system of claim 14 wherein means for creating the protowidget further comprises means for defining the protowidget in a scalable vector graphics language. 16. The system of claim 10 further comprising means for creating the master definition of a graphics display. 17. The system of claim 10 wherein means for rendering at least one instance of the protowidget further comprises means for creating in computer memory a data structure comprising an instance of the protowidget. 18. The system of claim 17 wherein the data structure comprising an instance of the protowidget further comprises a DOM. 19. A computer program product for rendering a GUI widget with a generic look and feel, the computer program product comprising: a recording medium; means, recorded on the recording medium, for receiving in a display device a master definition of a graphics display, the master definition including at least one graphics definition element, the graphics definition element comprising a reference to a protowidget and one or more instance parameter values means, recorded on the recording medium, for characterizing an instance of the protowidget, the protowidget comprising a definition of a generic GUI object, including generic display values affecting overall look and feel of the graphics display; and means, recorded on the recording medium, for rendering at least one instance of the protowidget to a graphics display in dependence upon the generic display values and the instance parameter values. 20. The computer program product of claim 19 wherein means, recorded on the recording medium, for rendering at least one instance of the protowidget further comprises means, recorded on the recording medium, for inserting in the instance of the protowidget the instance parameter values from the master definition. 21. The computer program product of claim 19 wherein means, recorded on the recording medium, for rendering at least one instance of the protowidget further comprises means, recorded on the recording medium, for creating instance display values for the instance of the protowidget in dependence upon the instance parameter values. 22. The computer program product of claim 21 wherein: the protowidget further comprises at least one generic display rule, and means, recorded on the recording medium, for creating instance display values for the instance of the protowidget further comprises means, recorded on the recording medium, for creating instance display values for the instance of the protowidget in dependence upon the generic display rule. 23. The computer program product of claim 19 further comprising means, recorded on the recording medium, for creating the protowidget. 24. The computer program product of claim 23 wherein means, recorded on the recording medium, for creating the protowidget further comprises means, recorded on the recording medium, for defining the protowidget in a scalable vector graphics language. 25. The computer program product of claim 19 further comprising means, recorded on the recording medium, for creating the master definition of a graphics display. 26. The computer program product of claim 19 wherein means, recorded on the recording medium, for rendering at least one instance of the protowidget further comprises means, recorded on the recording medium, for creating in computer memory a data structure comprising an instance of the protowidget. 27. The computer program product of claim 26 wherein the data structure comprising an instance of the protowidget further comprises a DOM. | BACKGROUND OF THE INVENTION 1. Field of the Invention The field of the invention is data processing, or, more specifically, methods, systems, and products for rendering graphical user interface (“GUI”) widgets with generic look and feel. 2. Description of Related Art It is difficult to design an overall look and feel for GUI displays and at the same time allow third parties other than the designer to establish custom controls, GUI components, or widgets to their own specifications. The designer may not wish to hinder the developer's ability to lay out screens and displays, but it is difficult to maintain overall look and feel without limiting layout specifications. An inflexible example would involve a set of control attributes for a button, where the attributes are rectangle width, rectangle height, text color, and background color. This may work for simple button designs, but when a developer wishes to build elliptical buttons that contain icons, inflexible predetermination of width, height, color, and so on, is insufficient. SUMMARY OF THE INVENTION Methods, systems, and products are disclosed that operate generally to support application developers other than an original look and feel designer to set up custom control with arbitrary additional aspects of look and feel. Methods, systems, and products according to embodiments of the present invention typically render GUI widgets with generic look and feel by receiving in a display device a master definition of a graphics display, the master definition including at least one graphics definition element, the graphics definition element including a reference to a protowidget and one or more instance parameter values characterizing an instance of the protowidget, the protowidget includes a definition of a generic GUI object, including generic display values affecting overall look and feel of the graphics display. Typical embodiments also include rendering at least one instance of the protowidget to a graphics display in dependence upon the generic display values and the instance parameter values. In typical embodiments, rendering at least one instance of the protowidget includes inserting in the instance of the protowidget the instance parameter values from the master definition. In some embodiments, rendering at least one instance of the protowidget includes creating instance display values for the instance of the protowidget in dependence upon the instance parameter values. In many embodiments, the protowidget also includes at least one generic display rule and creating instance display values for the instance of the protowidget includes creating instance display values for the instance of the protowidget in dependence upon the generic display rule. Typical embodiments include creating the protowidget, defining the protowidget in a scalable vector graphics language, and creating the master definition of a graphics display. In typical embodiments, rendering at least one instance of the protowidget also includes creating in computer memory a data structure representing an instance of the protowidget. In such embodiments, the data structure may be implemented as a DOM. The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular descriptions of exemplary embodiments of the invention as illustrated in the accompanying drawings wherein like reference numbers generally represent like parts of exemplary embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 sets forth a diagram of a system for rendering GUI widgets with generic look and feel. FIG. 2 sets forth a line drawing that depicts an exemplary graphics display on a computer running a data communication application. FIG. 3 sets forth a block diagram of automated computing machinery comprising a computer useful to render GUI widgets with generic look and feel. FIG. 4 sets forth a flow chart illustrating an exemplary method for rendering a GUI widget with generic look and feel. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS Introduction The present invention is described to a large extent in this specification in terms of methods for rendering GUI widgets with generic look and feel. Persons skilled in the art, however, will recognize that any computer system that includes suitable programming means for operating in accordance with the disclosed methods also falls well within the scope of the present invention. Suitable programming means include any means for directing a computer system to execute the steps of the method of the invention, including for example, systems comprised of processing units and arithmetic-logic circuits coupled to computer memory, which systems have the capability of storing in computer memory, which computer memory includes electronic circuits configured to store data and program instructions, programmed steps of the method of the invention for execution by a processing unit. The invention also may be embodied in a computer program product, such as a diskette or other recording medium, for use with any suitable data processing system. Embodiments of a computer program product may be implemented by use of any recording medium for machine-readable information, including magnetic media, optical media, or other suitable media. Persons skilled in the art will immediately recognize that any computer system having suitable programming means will be capable of executing the steps of the method of the invention as embodied in a program product. Persons skilled in the art will recognize immediately that, although most of the exemplary embodiments described in this specification are oriented to software installed and executing on computer hardware, nevertheless, alternative embodiments implemented as firmware or as hardware are well within the scope of the present invention. Rendering GUI Widgets With Generic Look and Feel Methods, systems, and products for rendering GUI widgets with generic look and feel are explained with reference to the accompanying drawings beginning with FIG. 1. FIG. 1 sets forth a diagram of a system for rendering GUI widgets with generic look and feel that operates generally by receiving in a display device (124) a master definition (104) of a graphics display. In the example of FIG. 1 the master definition includes at least one graphics definition element (106) that includes a reference (108) to a protowidget and one or more instance parameter values (110) characterizing an instance of the protowidget. In the example of FIG. 1, the protowidget (128) is a definition of a generic GUI object that includes generic display values (130) affecting overall look and feel of the graphics display and generic display rules (118) for use in deriving instance display values (116) from instance parameter values (110). In the system of FIG. 1, a display device (124) with a graphics display (126) renders at least one instance (112) of the protowidget (128) to a graphics display (126) in dependence upon the generic display values (130) and the instance parameter values (110). A widget is a graphical user interface (“GUI”) component that displays information and implements user input for interfacing with software applications and operating systems. ‘Widget’ is a term that is often used to refer to such graphical components. In some environments other terms are used for the same thing. In Java environments, for example, widgets are often referred to as ‘components.’ In other environments, widgets may be referred to as ‘controls’ or ‘containers.’ This disclosure, for clarity of explanation, uses the term ‘widget’ generally to refer to such graphical components. Examples of widgets include buttons, dialog boxes, pop-up windows, pull-down menus, icons, scroll bars, resizable window edges, progress indicators, selection boxes, windows, tear-off menus, menu bars, toggle switches, checkboxes, and forms. The term ‘widget’ also refers to the underlying software program that displays the graphic component of the widget in a GUI and operates the widget, depending on what action the user takes while operating the GUI in response to the widget. That is, ‘widget,’ depending on context, refers to data making up a GUI component, a software program controlling a GUI component, or to both the data and the program. A protowidget is a widget definition from which widgets may be instantiated with similar generic look and feel but different instance characteristics. Protowidgets typically are created by a generic look and feel designer operating a graphics editor on a graphics workstation or personal computer (120). Protowidgets may include generic display values (130) that govern the overall look and feel of a display, values that may be similar for a related group of protowidgets defining, buttons, dialog boxes, pull-down menus, and so on, all supporting the creation of instances of the protowidgets having a similar overall generic look and feel. Such a similar overall generic look and feel is sometimes referred to as a ‘skin,’ and GUI displays created by use of protowidgets according to instances of the present invention may be considered readily ‘skinnable.’ An instance of a protowidget, of course, is a widget, but for clarity in this specification, an instance derived from a protowidget is referred to as an ‘instance.’ A protowidget is typically defined in a graphics definition language, such as, for example, “SVG,” the Scalable Vector Graphics language, a modularized language for describing graphics in XML, the eXtensible Markup Language. The SVG specification is promulgated by the World Wide Web Consortium. A master definition (104) of a graphics display is a description of a display for one or more widgets, that is, instances of protowidgets. That is, the master definition lists protowidgets and describes how instances of them are to be created and displayed. Multiple instances of a single protowidget may be described in a master definition. That is, a protowidget defining a tool bar button, for example, may be instantiated and used at several locations on a single GUI display to perform several different functions. For further explanation, consider the example of the display shown in FIG. 2. FIG. 2. FIG. 2 sets forth a line drawing that depicts an exemplary graphics display on a computer running a data communication application, more particularly, in the example of FIG. 2, a web browser. The browser of FIG. 2, as depicted, has been operated by a user to point to a web site named “SomeSearchEngine.com,” as shown in the title bar of the browser display (314). The browser of FIG. 2 includes a GUI toolbar (318) with a Back button, a Forward button, and buttons for refreshing the display, searching, printing, and stopping web page retrievals. The browser of FIG. 2 also includes a horizontal menu (316) containing the menu items File, Edit, View, Bookmark (sometimes called “Favorites”), Tools, and Help. The browser of FIG. 2 displays a search query, “mine geology,” displayed in a query entry field (328). In this example, a user ceased operations just before invoking the search feature (320) of the search engine, so that the area of the graphics display in which search results are displayed is still empty (322). The graphics display in this example includes an advertisement (308) that supports a hyperlink labeled “CLICK HERE.” In the example of FIG. 2, every graphical object on the display may be a widget, that is, an instantiation of a protowidget. In particular, all the buttons on the toolbar (318) may be instantiations of a single button protowidget instantiated several times to form multiple widgets having generic look and feel with differing instance display values effecting differing locations with differing label text. That fact the exemplary application of FIG. 2 is represented as a browser is not a limitation of the present invention. On the contrary, many applications that implement rendering GUI widgets with generic look and feel are useful in various embodiments of the present invention, including email clients, word processors, database applications such as are used by personal digital assistants (“PDAs”), and so on. The use of all such applications, and others as will occur to those of skill in the art, is well within the scope of the present invention. In the system of FIG. 1, a display device (124) with a graphics display (126) renders at least one instance (112) of the protowidget (128) to a graphics display (126) in dependence upon generic display values (130) and instance parameter values (110). Generic display values (130) are display values effecting overall look and feel of a display or a set of related displays, as, for example, a set of display screens related in the sense that they are all screens provided by a single software application or a single web site. Generic overall look and feel is the fact that such screens advantageously provide widgets having similar edge treatments, similar colors, similar hatching and shading, similar fonts in their labels and other text elements, and so on. Instance parameter values (110) are values affecting the creation and display of a particular widget without affecting overall look and feel. Examples of instance display values include display location, height, width, label text, and so on. In the system of FIG. 1, a look and feel designer uses a graphics editor on a workstation (120) to create one or more protowidgets (128). Each protowidget is a definition of a type of widget that may be instantiated by use of the protowidget and one or more instance parameter values from a master definition (104). Each protowidget in this example includes generic display values (130) and generic display rules (118). Generic display rules are rules that are applied to instance parameter values (114) when a widget is rendered to create instance display values (116). In many systems according to embodiments of the present invention, creating a protowidget is carried out by expressing the protowidget in a scalable vector graphics language such as SVG from the World Wide Web Consortium. In the system of FIG. 1, an application developer uses a graphics editor on a workstation (122) to create a master definition (104) of a graphics display. A master definition may advantageously be expressed in an XML language, although in some embodiments at least the master definition language is not be the language in which protowidgets are specified. The master definition language may manipulate protowidgets at a level of abstraction above the protowidgets. In other words, a language for specifying a display of widgets defined in an XML language such as SVG advantageously is a kind of superset of SVG. Given the flexibility of XML language specification, many such super-languages no doubt will occur to those of skill in the art, but one example of a language in which master definitions of graphics may be expressed is MXML from Macromedia, Inc., 600 Townsend Street, San Francisco, Calif. 94103. MXML is an XML-based markup language used to declaratively describe the layout of widgets on a graphics display, and an object-oriented programming language which handles user interactions with an application. MXML runs on a presentation server from Macromedia called “Flex.” Flex is a presentation server installed on top of a Java™ application server or servlet container. Here is an example of a master definition (104) of a graphics display expressed in MXML: <?xml version=“1.0” encoding=“UTF-8”?> <mx:Application width=‘700’ height=‘700’ xmlns:mx=“http://www.macromedia.com/2003/mxml” > <mx:VBox> <mx:Button id=“button1” label=“Press Me” width=“125” height=“35” /> <mx:CheckBox id=“checkbox1” label=“Check Me” /> <mx:ComboBox id=“combobox1” width=“100” height=“35”/> </mx:VBox> </mx:Application> This exemplary master definition lists references to three protowidgets, a Button, a CheckBox, and a ComboBox. The Button has instance parameter values for an identification code of ‘button1,’ for a width of ‘125’ , and for a height of ‘35‘. The CheckBox has instance parameter values for an identification code of ‘checkbox1’ and for label text of ‘Check Me.’ The ComboBox has instance parameter values for an identification code of ‘combobox1,’ for a width of ‘100’, and for a height of ‘35.’ The references to all three protowidgets include a namespace identifier ‘mx’ at a location in cyberspace specified by the URL: “http://www.macromedia.com/2003/mxml.” The URL identifies the location of the protowidgets for each reference, the Button, the CheckBox, and the ComboBox. That is, in this example, a reference to a protowidget is implemented as a markup element name of another markup document where the protowidget is defined. As described in more detail below, the protowidgets found at the URL contain the pertinent generic display values and generic display rules effecting their overall look and feel. Display devices in this specification are generally computers, that is, any automated computing machinery having a graphics display. The terms “display device” or “computer” include not only general purpose computers such as laptops, personal computer, minicomputers, and mainframes, but also devices such as personal digital assistants (“PDAs), network enabled handheld devices, internet-enabled mobile telephones, and so on. FIG. 3 sets forth a block diagram of automated computing machinery comprising a computer (134) useful according to various embodiments of the present invention to render GUI widgets with generic look and feel. The computer (134) of FIG. 3 includes at least one computer processor (156) or ‘CPU’ as well as random access memory(168) (“RAM”). Stored in RAM (168) is are two application program, a graphics editor (186) and a browser (188). The use of a graphics editor and a browser is for explanation, not for limitation. Application programs useful in rendering GUI widgets with generic look and feel in accordance with various embodiments of the present invention include browsers, word processors, spreadsheets, database management systems, email clients, and others as will occur to those of skill in the art. Also stored in RAM (168) is an operating system (154). Operating systems useful in computers according to embodiments of the present invention include Unix, Linux198 , Microsoft NT™M, and others as will occur to those of skill in the art. In the example of FIG. 3, operating system (154) also includes at least one device driver for use in input/output communications among applications (186 and 188), user input devices (180), and graphics displays (180). Examples of graphics displays include GUI screens, touch sensitive screens, a liquid crystal displays, and the like. Examples of user input devices include mice, keyboards, numeric keypads, touch sensitive screens, microphones, and so on. The example computer (134) of FIG. 3 includes computer memory (166) coupled through a system bus (160) to the processor (156) and to other components of the computer. Computer memory (166) may be implemented as a hard disk drive (170), optical disk drive (172), electrically erasable programmable read-only memory space (so-called ‘EEPROM’ or ‘Flash’ memory) (174), RAM drives (not shown), or as any other kind of computer memory as will occur to those of skill in the art. The example computer (134) of FIG. 3 includes communications adapter (167) that implements connections for data communications (184) to other computers (182). Communications adapters (167) implement the hardware level of data communications connections through which client computers and servers send data communications directly to one another and through networks. Examples of communications adapters (167) include modems for wired dial-up connections, Ethernet (IEEE 802.3) adapters for wired LAN connections, 802.11 adapters for wireless LAN connections, and Bluetooth adapters for wireless microLAN connections. The example computer of FIG. 3 includes one or more input/output interface adapters (178). Input/output interface adapters (178) in computer (134) include hardware that implements user input/output to and from user input devices (181) and graphics display (180). Examples of input/output interface adapters include mouse adapters, keyboard adapters, and particularly graphics adapters. For further explanation, FIG. 4 sets forth a flow chart illustrating an exemplary method for rendering a GUI widget with a generic look and feel that includes receiving (402) in a display device a master definition (104) of a graphics display, the master definition including at least one graphics definition element (106). In the example of FIG. 4, the graphics definition element (106) includes a reference (108) to a protowidget and one or more instance parameter values (110) characterizing an instance of the protowidget. In the example of FIG. 4, the protowidget (128) includes a definition of a generic GUI object which in turn includes generic display values (130) affecting overall look and feel of the graphics display. The exemplary method of FIG. 4 also includes rendering (406) at least one instance (112) of the protowidget (128) to a GUI display (126) in dependence upon the generic display values (130) and the instance parameter values (110). In the method of FIG. 4, rendering at least one instance (112) of the protowidget includes creating in computer memory a data structure comprising an instance (112) of the protowidget (128). In the method of FIG. 4, a data structure comprising an instance (112) of the protowidget (128) may be implemented as a DOM. A DOM is a ‘Document Object Model,’ a data structure created according to a specification for how the graphical elements of a document are represented and rendered. A DOM contains attribute values defining graphics objects, and provides an API (application programming interface) for manipulating the graphics objects. The Dynamic HyperText Markup Language (“DHTML”), for example, relies on a DOM to dynamically change the appearance of Web pages after they have been downloaded to a user's browser. Netscape and Microsoft specify HTML DOMs for their browsers, but the W3C's DOM specification supports both HTML and XML. The W3C's DOM specification includes an API for valid HTML and well-formed XML documents. It defines the logical structure of documents and the way a document is accessed and manipulated. A DOM may be used to manage or manipulate any graphics components or widgets represented in compliant XML. With a DOM, programmers can build documents, navigate their structure, and add, modify, or delete elements and content. Almost anything found in an HTML or XML document can be accessed, changed, deleted, or added using a DOM. The specification for the DOM API for use with any programming language. The specification itself at this time provides language bindings for Java and ECMAScript, an industry-standard scripting language based on JavaScript and JScript. In the method of FIG. 4, rendering (406) at least one instance (112) of the protowidget (128) includes inserting (408) in the instance (112) of the protowidget the instance parameter values (110) from the master definition (104) and creating (410) instance display values (116) for the instance (112) of the protowidget (128) in dependence upon the instance parameter values (114). In the method of FIG. 4, the protowidget (128) includes at least one generic display rule (118) and creating (410) instance display values (116) for the instance (112) of the protowidget (128) is carried out by creating instance display values for the instance (112) of the protowidget (128) in dependence upon the generic display rule (118). The following exemplary SVG representation of a protowidget for a GUI button is provided for further explanation: <?xml version=“1.0” encoding=“iso-8859-1”?> <!DOCTYPE svg PUBLIC “-//W3C//DTD SVG 20000303 Stylable//EN” “http://www.w3.org/TR/2000/03/WD-SVG-20000303/DTD/svg- 20000303-stylable.dtd”> <svg id=“svgRoot” xml:space=“preserve” width=“300” height=“300”> <desc>MXML Button</desc> <style type=“text/css”> <![CDATA[ .t1 { fill: #00ff00; stroke: #ff0000; } .t2 { text-anchor: middle; } ]]> </style> <!-- Begin ECMA Script --> <script type=“text/ecmascript”> <![CDATA[ var parms = document.getElementById(“parms”); var rect1 = document.getElementById(“Button.rect1”); var rect2 = document.getElementById(“Button.rect2”); var text = document.getElementById(“Button.text”); function setX(att) { } function setY(att) { } function setWidth(att) { rect1.setAttribute(“width”, att-1); rect2.setAttribute(“width”, att-5); text.setAttribute(“x”, att/2); } function setHeight(att) { rect1.setAttribute(“height”, att-1); rect2.setAttribute(“height”, att-5); text.setAttribute(“y”, att*7/10); } function setBackgroundColor(att) {rect2.setAttribute(“fill”, att); } function setColor(att) { rect1.setAttribute(“stroke”, att); rect2.setAttribute(“stroke”, att); text.setAttribute(“fill”, att); } function setLabel(att) { var fc = text.getFirstChild( ); alert(“fc: ”+fc); fc.setNodeValue(att); } function setFontFamily(att) {text.setAttribute(“font-family”, att); } function setFontSize(att) {text.setAttribute(“font-size”, att); } function setFontStyle(att) { text.setAttribute(“font-style”, att);} function setFontWeight(att) {text.setAttribute(“font-weight”, att); } <!-- Begin Set Parms function --> function setParms(evt) { if (parms.hasAttribute(“MxmlX”)) { setX(parms.getAttribute(“MxmlX”)); } if (parms.hasAttribute(“MxmlY”)) { setY(parms.getAttribute(“MxmlY”)); } if (parms.hasAttribute(“MxmlWidth”)) { setWidth(parms.getAttribute(“MxmlWidth”)); } if (parms.hasAttribute(“MxmlHeight”)) { setHeight(parms.getAttribute(“MxmlHeight”)); } if (parms.hasAttribute(“MxmlBackgroundColor”)) { setBackgroundColor(parms.getAttribute( “MxmlBackgroundColor”));} if (parms.hasAttribute(“MxmlColor”)) { setColor(parms.getAttribute(“MxmlColor”)); } if (parms.hasAttribute(“MxmlLabel”)) { setLabel(parms.getAttribute(“MxmlLabel”)); } if (parms.hasAttribute(“MxmlFontFamily”)) { setFontFamily(parms.getAttribute( “MxmlFontFamily”));} if (parms.hasAttribute(“MxmlFontSize”)) { setFontSize(parms.getAttribute(“MxmlFontSize”));} if (parms.hasAttribute(“MxmlFontStyle”)) { setFontStyle(parms.getAttribute(“MxmlFontStyle”));} if (parms.hasAttribute(“MxmlFontWeight”)) { setFontWeight(parms.getAttribute( “MxmlFontWeight”)); } setLabel(“test”); } ]]> </script> <!-- Begin Component Definitions --> <rect id=“parms” x=“0” y=“0” width=“0” height=“0” fill=“none” stroke=“none”/> <symbol id=“Button”> <rect id=“Button.rect1” x=“0” y=“0” width=“50” height=“22” rx=“3” ry=“3” fill=“#ffffff” stroke=“#949694”/> <rect id=“Button.rect2” x=“2” y=“2” width=“46” height=“18” rx=“2” ry=“2” fill=“#ffffff” stroke=“#D6DADC”/> <text id=“Button.text” class=“t2” x=“25” y=“16” font- size=“12” fill=“#000000”>mx:Button</text> </symbol> <!-- Begin Component Usage --> <use id=“Button.use” xlink:href=“#Button” onload=“setParms(evt)”/> </svg> This exemplary protowidget contains two SVG component definitions, one for the button itself, <symbol id=“Button”>, and another component definition: <rect id=“parms” x=“0” y=“0” width=“0” height=“0” fill=“none” stroke=“none”/> defining storage locations for instance parameter values. The rectangle having id=“parms” is considered a dummy component, not to be displayed, but provided only to define the storage space for the instance parameter values inside an instance of the protowidget, such as, for example, a DOM. In the example of FIG. 4, the instance (112) of the protowidget (128) under processing may typically be implemented as a DOM. In fact, as a practical matter, in an example like the method of FIG. 4, the master definition (104) also is represented initially as XML and then parsed into a DOM in computer memory for processing through a DOM's API. Using the exemplary SVG protowidget defined above, inserting (408) in the instance (112) of the protowidget the instance parameter values (110) from the master definition (104) is carried out at render time by calling the function identified in the component usage description in the SVG definition: <use id=“Button.use” ... onload=“setParms(evt)”/> That is, the rendering function at render time calls the ‘onload’ function defined in the SVG for the protowidget, “setParms( ).” The setParms( ) function tests with an if( ) statement whether each supported instance parameter has a value in the master definition (“parms”), and, if the value is present, setParmtZ( ) sets that value in a DOM representing an instance of the protowidget. The functions setX( ), setY( ), setWidth( ), setHeight( ), and so on, are DOM API functions. In this example, creating (410) instance display values (116) for the instance (112) of the protowidget (128) in dependence upon the instance parameter values (114) may be carried out in a trivial example by using the instance parameter values as instance display values. Often, however, the protowidget (128) includes at least one generic display rule (118) and creating (410) instance display values (116) for the instance (112) of the protowidget (128) is carried out by creating instance display values for the instance (112) of the protowidget (128) in dependence upon the generic display rule (118). In the exemplary SVG protowidget set forth above, a generic display rule is exemplified by the member method: function setWidth(att) { rect1.setAttribute(“width”, att-1); rect2.setAttribute(“width”, att-5); text.setAttribute(“x”, att/2); } in which the value of the parameter ‘att’ is an instance parameter value which is used according to processing rules to produce instance display values. In this example, the generic display rules may be interpreted as: for a first rectangle defining the screen appearance of a button, create the instance display value for the width of the first rectangle as the instance parameter value minus 1 for a second rectangle defining the screen appearance of a button, create the instance display value for the width of the second rectangle as the instance parameter value minus 5 for button text defining the screen appearance of a button, create the instance display value for the button text as the instance parameter value divided by 2 It will be understood from the foregoing description that modifications and changes may be made in various embodiments of the present invention without departing from its true spirit. The descriptions in this specification are for purposes of illustration only and are not to be construed in a limiting sense. The scope of the present invention is limited only by the language of the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The field of the invention is data processing, or, more specifically, methods, systems, and products for rendering graphical user interface (“GUI”) widgets with generic look and feel. 2. Description of Related Art It is difficult to design an overall look and feel for GUI displays and at the same time allow third parties other than the designer to establish custom controls, GUI components, or widgets to their own specifications. The designer may not wish to hinder the developer's ability to lay out screens and displays, but it is difficult to maintain overall look and feel without limiting layout specifications. An inflexible example would involve a set of control attributes for a button, where the attributes are rectangle width, rectangle height, text color, and background color. This may work for simple button designs, but when a developer wishes to build elliptical buttons that contain icons, inflexible predetermination of width, height, color, and so on, is insufficient. | <SOH> SUMMARY OF THE INVENTION <EOH>Methods, systems, and products are disclosed that operate generally to support application developers other than an original look and feel designer to set up custom control with arbitrary additional aspects of look and feel. Methods, systems, and products according to embodiments of the present invention typically render GUI widgets with generic look and feel by receiving in a display device a master definition of a graphics display, the master definition including at least one graphics definition element, the graphics definition element including a reference to a protowidget and one or more instance parameter values characterizing an instance of the protowidget, the protowidget includes a definition of a generic GUI object, including generic display values affecting overall look and feel of the graphics display. Typical embodiments also include rendering at least one instance of the protowidget to a graphics display in dependence upon the generic display values and the instance parameter values. In typical embodiments, rendering at least one instance of the protowidget includes inserting in the instance of the protowidget the instance parameter values from the master definition. In some embodiments, rendering at least one instance of the protowidget includes creating instance display values for the instance of the protowidget in dependence upon the instance parameter values. In many embodiments, the protowidget also includes at least one generic display rule and creating instance display values for the instance of the protowidget includes creating instance display values for the instance of the protowidget in dependence upon the generic display rule. Typical embodiments include creating the protowidget, defining the protowidget in a scalable vector graphics language, and creating the master definition of a graphics display. In typical embodiments, rendering at least one instance of the protowidget also includes creating in computer memory a data structure representing an instance of the protowidget. In such embodiments, the data structure may be implemented as a DOM. The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular descriptions of exemplary embodiments of the invention as illustrated in the accompanying drawings wherein like reference numbers generally represent like parts of exemplary embodiments of the invention. | 20040226 | 20100406 | 20050901 | 60071.0 | 1 | KUMAR, ANIL N | RENDERING GUI WIDGETS WITH GENERIC LOOK AND FEEL | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,788,012 | ACCEPTED | FRUIT/VEGETABLE BLENDER HAVING MULTI-SPEED CONTROL SWITCH | A fruit/vegetable blender having a multi-speed control switch comprises a speed controller mounted on the motor house thereof, for controlling power on/off and motor speed. The speed controller utilizes a variable resistor, a flexible conducting plate, a conducting slider, a push button, a slider handle and a plurality of conducting ports along the variable resistor to provide a resistance adjusting mechanism, thereby the motor speed changing accordingly. The multi-speed control switch is further protected by an inner retaining plate, an outer retaining plate, a wavy plate and a water-resistant pad from water infiltration. | 1. A fruit/vegetable blender having a multi-speed control switch, comprising: a motor house made of stainless steel and provided with a slot, a through hole and a plurality of insertion holes on a lateral wall thereof; a base provided with a ring-shaped inner wall along the rim of a top side thereof, said inner wall and said rim forming a ring groove for providing a firm engaging mechanism with the bottom side of said motor house; an inner retaining plate attached to an inner wall of said motor house and provided with a plurality of hollow positioning tubes, a through hole and a slot, said through hole and said sliding slot respectively corresponding to said slot and said through hole of said motor house; an outer retaining plate attached to an outer wall of said motor house and provided with a plurality of solid positioning posts that can be coupled to said hollow positioning tubes of said inner retaining plate, said outer retaining plate further including a through hole and a sliding slot respectively corresponding to said slot and said through hole of said motor house; a water-resistant pad sandwiched by said outer wall of said motor house and an inner face of said outer retaining plate, said water-resistant pad covering along the border of said inner face of said outer retaining plate, said water-resistant pad being for protecting said motor house from water infiltration from outside; a speed controller including a circuit board that is provided with a variable resistor, a flexible conducting plate and a power connecting point, said power connecting point being connected to a power socket through a wire, one end of said flexible conducting plate being connected to said variable resistor through another wire, said push button controlling the connection of another end of said flexible conducting plate to said power connecting point, said variable resistor further including a wire connected to a motor, a plurality of conducting ports and a conducting slider having a projection, said conducting slider bridging two of said conducting ports so as to define a resistance for said variable resistor, said conducting slider being capable of sliding along said variable resistor to switch said resistance to other values, whereby the variation in said resistance provides a control mechanism for changing the rotational speed of said motor; wherein said speed controller is locked by a set of screws onto the top ends of said positioning posts extending from said outer retaining plate after being coupled with said hollow positioning tubes extending from said inner retaining plate, whereby said inner retaining plate and said outer retaining plate can be respectively attached onto two opposite sides of said lateral wall of said motor house; and a wavy plate disposed between said outer wall of said motor house over said slot thereon and said inner face of said outer retaining plate over said sliding slot thereon so as to shield said slot of said motor house from liquid drops and dust from outside; a slider handle going through said sliding slots of said outer retaining plate and said inner retaining plate, as well as said wavy plate, and being connected to said projection of said conducting slider of said variable resistor, whereby said slider handle urges a sliding motion of said conducting slider along said variable resistor. | FIELD OF THE INVENTION The present invention relates to fruit/vegetable blenders, more particularly to a fruit/vegetable blender having a multi-speed control switch and a water-resistant mechanism. DESCRIPTION OF THE PRIOR ART Restricted by the problem of water infiltration, the speed control switches for a fruit/vegetable blender of the prior art are a panel including a plurality of buttons respectively corresponding to different rotational speeds. It is common that the conventional speed control switches consist of three speed selecting buttons, respectively for high, middle and low speed, and a power switch. Therefore, the conventional speed control switch cannot have many speed options, and, further, the push buttons may fail after being used for an extended period of time. SUMMARY OF THE INVENTION Accordingly, the present invention as fruit/vegetable blender having a multi-speed control switch comprises a switching means for controlling rotational speed. The switching means has a circuit board, a variable resistor and a flexible conducting plate, which can not only control the power on/off but also slidably position the resistor to a suitable resistance so as to select a preferred rotational speed. The fruit/vegetable blender having a multi-speed control switch further includes a water-resistant means for preventing water infiltration into the motor housing base. The means includes a water-resistant pad, a wavy plate, an inner retaining plate and an outer retaining plate. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of the motor base of a fruit/vegetable blender having a multi-speed control switch according to the present invention. FIG. 2 is a cross-sectional view of a fruit/vegetable blender having a multi-speed control switch according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 2, a fruit/vegetable blender having a multi-speed control switch according to the present invention comprises a motor house 1, a base 4, an inner retaining plate 20, a water-resistant pad 24, an outer retaining plate 30, a wavy plate 25 and a speed controller 10. A motor M is housed within the motor house 1 and is integrally mounted on the base 4. The motor house 1 is made of stainless steel and is provided with a slot 2, a through hole 3 and a plurality of insertion holes 101 for retaining parts of the speed control switch. The through hole 3 is for receiving a push button 7. The base 4 is provided with an inner wall 5 that is concentric with the inner rim thereof, so as to form a ring groove 6 for being coupled to the bottom end of the motor house 1. The inner retaining plate 20 is attached to the inner wall of the motor house 1 and is provided with hollow positioning tubes 21, a through hole 23 and a sliding slot 22. The through hole 23 and the sliding slot 22 respectively correspond to the slot 2 and the through hole 3 of the motor house 1. The outer retaining plate 30 is attached to the outer wall of the motor house 1 and is provided with solid positioning posts 31 capable of being respectively inserted into the hollow positioning tubes 21 of the inner retaining plate 20. The outer retaining plate 30 further includes a through hole 33 and a sliding slot 32, respectively corresponding to the slot 2 and the through hole 3 of the motor house 1. The water-resistant pad 24 is sandwiched by the outer wall of the motor house 1 and the inner face of the outer retaining plate 30; the water-resistant pad 24 covers along the border of inner face of the outer retaining plate 30. The water-resistant pad 24 is for preventing water infiltration from outside the motor house 1. The speed controller 10 includes a circuit board 11 that is provided with a variable resistor 12, a flexible conducting plate 14 and a power connecting point 13. The power connecting point 13 is connected to a power socket through a wire. One end of the flexible conducting plate 14 is connected to the variable resistor 12 through a wire. Controlled by the push button 7, another end of the flexible conducting plate 14 can be connected or disconnected to the power connecting point 13. The variable resistor 12 further includes a wire connected to the motor M, a plurality of conducting ports 120 and a conducting slider 15 having a projection 16. The conducting slider 15 bridges two of the conducting ports 120 so as to define a resistance for the variable resistor 12, and, as it slides up and down, the resistance switches to other values. The variation in resistance provides a control mechanism for changing the rotational speed of the motor M. Further, a slider handle 34 goes through the sliding slots 32, 22 of the outer retaining plate 30 and the inner retaining plate 20, as well as the wavy plate 25, and is connected to the projection 16 of the conducting slider 15 of the variable resistor 12, for actuating a sliding motion of the conducting slider 15 along the variable resistor 12. The speed controller 10 is locked by a set of screws on the positioning posts 31 of the outer retaining plate 30 under the condition that the positioning posts 31 are coupled with the hollow positioning tubes 21 of the inner retaining plate 20. Thereby, the inner retaining plate 20 and the outer retaining plate 30 are attached respectively onto the inner wall and the outer wall of the motor house 1. The wavy plate 25 is disposed between the slot 2 on the outer wall of the motor house 1 and the slot 32 on the inner face of the outer retaining plate 30, so as to shield the slot 2 from the invasion of liquid drops and dust from outside. To use the aforesaid fruit/vegetable blender having a multi-speed control switch, the push button 7 is pushed to connect the power connecting point 13 and the variable resistor 12. The slider handle 34 is then urged to move up and down by which the conducting slider 15 slides along the variable resistor 12 so as to connect two conducting ports 120 corresponding to a desired motor speed. The smaller the resistance of the variable resistor 12, the higher is the motor speed. The motor M rotates a blade set 8 within the food container 80 to mince the fruit/vegetable therein, as shown in FIG. 2. The present invention has the advantages as follows. The ring groove 5 defined by the ring wall 6 and the outer rim of the base 4 provides a firm engaging structure by which the motor house 1 can be mounted on the base 4. The coupling of the positioning posts 31 and the hollow positioning tubes 21 provides a firm connection of the outer retaining plate 30 and the inner retaining plate 20 with the motor house 1. The speed controller 10 is connected to the positioning posts 31 and the hollow positioning tubes 21, which are non-metallic (plastic) parts, and therefore is electrically insulated. The water-resistant pad 24 pinched between the outer retaining plate 30 and the motor house 1 protects the motor house 1 from water infiltration from outside. The wavy plate 25, capable of extending and contracting along the direction the slot 2 extends, provides a water-resistant effect for the slot 2 of the motor house 1. The multiple speed control mechanism achieved the variable resistor 12 provides many speed options for a user. | <SOH> FIELD OF THE INVENTION <EOH>The present invention relates to fruit/vegetable blenders, more particularly to a fruit/vegetable blender having a multi-speed control switch and a water-resistant mechanism. | <SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, the present invention as fruit/vegetable blender having a multi-speed control switch comprises a switching means for controlling rotational speed. The switching means has a circuit board, a variable resistor and a flexible conducting plate, which can not only control the power on/off but also slidably position the resistor to a suitable resistance so as to select a preferred rotational speed. The fruit/vegetable blender having a multi-speed control switch further includes a water-resistant means for preventing water infiltration into the motor housing base. The means includes a water-resistant pad, a wavy plate, an inner retaining plate and an outer retaining plate. | 20040227 | 20051122 | 20050901 | 92575.0 | 0 | SOOHOO, TONY GLEN | FRUIT/VEGETABLE BLENDER HAVING MULTI-SPEED CONTROL SWITCH | SMALL | 0 | ACCEPTED | 2,004 |
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10,788,138 | ACCEPTED | Method and apparatus for delivery of bulk cement | A method for delivering a pre-weighed package comprising sand, aggregate and dry cement to a mixing site comprises the steps of preparing a first mixture comprising fine aggregate and course aggregate at an offsite plant. The first mixture is placed into a first storage compartment of a hopper and the load of dry cement is placed into a second storage compartment of the hopper. The hopper is transported to the mixing site, where the first mixture and the cement are discharged from the hopper and mixed to form a concrete slurry. The hopper comprises the first storage compartment and the second storage compartment, where there is a water tight dividing means separating the first storage compartment and the second storage compartment. The storage compartments have respective inlets and outlets for receiving and discharging the respective components. | 1. A method for delivering a pre-weighed package comprising fine aggregate, course aggregate and dry cement to a mixing site, the method comprising the steps of: (a) preparing a first mixture comprising fine aggregate and course aggregate; (b) weighing the first mixture; (c) weighing a load of the dry cement; (d) placing the first mixture into a first storage compartment of a bulk transport apparatus and placing the load of dry cement into a second storage compartment of the bulk transport apparatus, the bulk transport apparatus comprising: (i) an outer shell having a top and a bottom, (ii) a water tight dividing means contained inside the shell, the water tight dividing means defining the first storage compartment and the second storage compartment; (iii) the first storage compartment having a first inlet for receiving the first mixture and a first outlet for discharging the first mixture; (iv) the second storage compartment having a second inlet for receiving the load of dry cement and a second outlet for discharging the load of dry cement; and (v) means for attachment to a lifting means connected to the outer shell; (e) loading the bulk transport apparatus onto transportation means with the lifting means; (f) transporting the bulk transport apparatus to the mixing site; (g) discharging the first mixture through the first outlet into a mixing means; and (h) discharging the load of dry cement through the second outlet into the mixing means. 2. The method of claim 1 wherein a weigh document is generated when the first mixture and the load of dry cement are weighed. 3. The method of claim 1 wherein the first storage compartment comprises a vessel enclosed within the shell. 4. The method of claim 1 wherein the second storage compartment comprises a vessel enclosed within the shell. 5. The method of claim 1 wherein the bulk transport apparatus further comprises means for vibrating the first storage compartment. 6. The method of claim 1 wherein the bulk transport apparatus further comprises means for vibrating the second storage compartment. 7. The method of claim 1 wherein the bulk transport apparatus further comprises a means for opening and closing the first outlet. 8. The method of claim 7 wherein the means for opening and closing the first outlet comprises a gate pivotally attached to the shell. 9. The method of claim 1 wherein the bulk transport apparatus further comprises a means for opening and closing the second outlet. 10. The method of claim 9 wherein the means for opening and closing the second outlet comprises a butterfly valve. 11. The method of claim 1 wherein the first mixture comprises an admix. 12. The method of claim 11 wherein the admix is selected from the group consisting of water reducer, water replacer, accelerant, retardant, extender, shrinkage reducer, air entrainer, strengthener, and porosity reducer. 13. The method of claim 11 wherein the admix is selected from any one or more of the group comprising water reducer, water replacer, accelerant, retardant, extender, shrinkage reducer, air entrainer, strengthener, and porosity reducer. 14. A method for delivering a pre-weighed package comprising fine aggregate, course aggregate and dry cement to a mixing site, the method comprising the steps of: (a) preparing a first mixture comprising fine aggregate and course aggregate; (b) weighing the first mixture; (c) weighing a load of the dry cement; (d) placing the first mixture into a first storage compartment of a bulk transport apparatus and placing the load of dry cement into a second storage compartment of the bulk transport apparatus, the bulk transport apparatus comprising: (i) an outer shell having a top and a bottom, (ii) a water tight dividing means contained inside the shell, the water tight dividing means defining the first storage compartment and the second storage compartment wherein the second storage compartment comprises a vessel; (iii) the first storage compartment having a first inlet for receiving the first mixture and a first outlet for discharging the first mixture; (iv) the second storage compartment having a second inlet for receiving the load of dry cement and a second outlet for discharging the load of dry cement; and (v) means for attachment to a lifting means connected to the outer shell; (e) loading the bulk transport apparatus onto transportation means with the lifting means; (f) transporting the bulk transport apparatus to the mixing site; (g) discharging the first mixture through the first outlet into a mixing means; and (h) discharging the load of dry cement through the second outlet into the mixing means. 15. The method of claim 14 wherein a weigh document is generated when the first mixture and the load of dry cement are weighed. 16. The method of claim 14 wherein the vessel is cylindrical. 17. The method of claim 16 wherein the vessel comprises a tapered bottom. 18. The method of claim 14 wherein the bulk transport apparatus further comprises means for vibrating the first storage compartment. 19. The method of claim 14 wherein the bulk transport apparatus further comprises means for vibrating the second storage compartment. 20. The method of claim 14 wherein the bulk transport apparatus further comprises a first valve means attached to the first outlet. 21. The method of claim 14 wherein the bulk transport apparatus further comprises a second valve means attached to the second outlet. 22. The method of claim 20 wherein the first valve means comprises a gate pivotally attached to the shell. 23. The method of claim 20 wherein the bulk transport apparatus further comprises a first actuation means for opening and closing the first valve means. 24. The method of claim 21 wherein the second valve means comprises a butterfly valve. 25. The method of claim 21 wherein the bulk transport apparatus further comprises a second actuation means for opening and closing the second valve means. 26. The method of claim 14 wherein the bulk transport apparatus further comprises support members attached to the outer shell. 27. The method of claim 14 wherein the bulk transport apparatus further comprises a first removable cover on the first inlet. 28. The method of claim 14 wherein the bulk transport apparatus further comprises a second removable cover on the second inlet. 29. A bulk transport apparatus comprising: a shell having an outside surface and an inside surface, a top, and a bottom; water tight dividing means enclosed within the shell, the water tight dividing means defining a first storage compartment and a second storage compartment contained within the shell; a first inlet extending through the top of the shell and connected to the first storage compartment; a first outlet extending from the first storage compartment through the shell to the exterior of the shell; a second inlet extending through the top of the shell and connected to the second storage compartment; a second outlet extending from the second storage compartment through the shell to the exterior of the shell; and a support structure comprising a cradle support and a plurality of legs attached to the cradle support, the cradle support engaging the shell. 30. The bulk transport apparatus of claim 29 wherein the shell is in the approximate shape of an inverted pyramid having a generally rectangular top and bounded by opposite-facing and matching sides. 31. The bulk transport apparatus of claim 29 wherein the first storage compartment comprises a vessel. 32. The bulk transport apparatus of claim 29 wherein the second storage compartment comprises a vessel. 33. The bulk transport apparatus of claim 32 wherein the vessel is cylindrical. 34. The bulk transport apparatus of claim 33 wherein the vessel has a tapered bottom. 35. The bulk transport apparatus of claim 29 further comprising weigh document storage means attached to the support structure. 36. The bulk transport apparatus of claim 29 further comprising means for vibrating the first storage compartment. 37. The bulk transport apparatus of claim 29 further comprising means for vibrating the second storage compartment. 38. The bulk transport apparatus of claim 29 further comprising a first valve means attached to the first outlet. 39. The bulk transport apparatus of claim 29 further comprising a second valve means attached to the second outlet. 40. The bulk transport apparatus of claim 38 further comprising a first actuation means for opening and closing the first valve means. 41. The bulk transport apparatus of claim 39 further comprising a second actuation means for opening and closing the second valve means. 42. The bulk transport apparatus of claim 38 wherein the first valve means comprises a gate pivotally attached to the shell. 43. The bulk transport apparatus of claim 39 wherein the second valve means comprises a butterfly valve. 44. The bulk transport apparatus of claim 29 further comprising a first removable cover on the first inlet. 45. The bulk transport apparatus of claim 29 further comprising a second removable cover on the second inlet. | BACKGROUND OF THE INVENTION The present invention relates to a method and apparatus for delivery of concrete to a job site, and more particularly to a method and apparatus by which the dry components of a concrete mixture are prepared in pre-weighed packages at a cement plant, delivered to the job site in the apparatus, and thereafter the dry components are blended together, mixed with water, and used as needed or desired. The logistics of providing concrete for a construction project can be quite complicated. Concrete is a mixture of a “paste” and aggregate, where the aggregate is typically a blend of course aggregate (gravel) and fine aggregate (sand). The paste, composed of portland cement and water, coats the surface of the fine and coarse aggregates. The paste hardens and gains strength to form concrete, a rock-like mass. Concrete therefore has the trait of being plastic and malleable when newly mixed, but strong and durable when hardened. Other additives or “admixes” may be added to provide various properties to the concrete, including water reducer, accelerant, retardant, foaming agents, and other density control additives. Soon after the aggregate, water, and the cement are combined together as a slurry, the mixture starts to harden. During the chemical reaction of the cement with the water (i.e., hydration), a node forms on the surface of each cement particle. The node grows and expands until it links up with nodes from other cement particles or adheres to adjacent aggregates. This process results in the progressive stiffening and hardening of the slurry and the gradual development of strength in the slurry. Therefore, once the cement is placed into contact with water through the mixing of the slurry components, the concrete should be placed as desired before the slurry becomes too stiff to be properly placed. It is important that the proper ratios of course aggregate, fine aggregate, cement and water be used in preparing the concrete slurry. The concrete slurry must be sufficiently workable for proper placement in the construction application, yet the hardened concrete must possess the required durability and strength for the application. A mixture which does not have sufficient paste to fill the voids between the aggregate components will be difficult to place and will produce rough honey-combed surfaces and porous concrete. However, a mixture with excess paste will be smoother and easier to place, but it is subject to shrinkage and is more expensive. Therefore, the methods of providing concrete to a job site must maintain the proper proportions of each of the components of the concrete. There are generally three different known methods for providing concrete to a construction site. In the first method, pre-measured sacks of dry cement and aggregate are delivered to the job site, where the sack is opened and mixed with water to create the concrete slurry. This method has the advantage of allowing the slurry to be mixed shortly before placement, allowing substantial time for placement of the slurry before the concrete begins to stiffen. However, this method has the disadvantage of being costly and labor intensive. Individual sacks of dry concrete are more expensive than concrete purchased in bulk. In addition to the added expense for packaging and handling, the aggregate in sack concrete must have a very low moisture content to prevent the cement from prematurely hydrating within the sack. The sacks are heavy, difficult to handle, and must be individually opened and mixed. A 94 pound sack of dry concrete when mixed with approximately 6 gallons of water yields less than 5 cubic feet of concrete. It is to be appreciated that because a common cement truck holds 9.5 cubic yards of concrete slurry (i.e., approximately 256 cubic feet), one would have to mix over 50 individual sacks of cement to equal the volume of slurry delivered by a single cement truck. By way of example, a 4 inch thick 1800 square foot concrete pad requires over 22 cubic yards of concrete, requiring three cement trucks to deliver the concrete slurry. This same job would require mixing and placing approximately 120 sacks of cement. Because of these limitations, the sack method is generally limited to very small jobs. The second method of providing concrete to a construction site is perhaps the most commonly used. In this method, concrete slurry comprising aggregate, cement and water is placed into cement trucks at a cement plant, and the trucks thereafter deliver the slurry to the job site. There are several disadvantages of this method. The concrete slurry should be poured within 90 minutes from the time the cement and aggregate are mixed with water. Therefore, the distance of the job site from the cement plant can limit or prevent use of this method. If the truck is delayed by traffic or other reasons and the concrete slurry not placed within the required time window, the concrete slurry cannot be used and it becomes waste material. Not only is the concrete lost, but it must then also be transported to a proper disposal site. Typically, it is desired that concrete be delivered to the construction site first thing in the morning. Accordingly, demand for concrete at the cement plant is high in the early morning. A cement plant might have a capacity of loading 15 to 20 trucks per hour. Depending upon the demand, there may be congestion at the cement plant, with a large number of cement trucks idling and waiting for concrete. If a particular construction project has a large demand for concrete, the number of trucks required to deliver concrete can be large, consuming large amounts of fuel, and emitting pollutants. The third method of delivering concrete to a construction site is only practical for very large construction projects. This method is to set up a portable plant on the job site, with separate bulk storage for each of the concrete components. The components are thereafter weighed, blended and mixed on the job site as required for the construction. While this method has the advantage of providing concrete on an as-needed basis, it is prohibitively expensive except for large projects. SUMMARY OF THE INVENTION The present invention is directed to an apparatus and method which meet the needs identified above for delivery of concrete to construction sites. A method for delivering a pre-weighed package comprising sand, aggregate and dry cement to a mixing site is disclosed. One embodiment of the method comprises the steps of preparing a first mixture comprising fine aggregate and course aggregate at an offsite plant. This first mixture is weighed. A load of dry cement is weighed. The first mixture is placed into a first storage compartment of a bulk transport apparatus (i.e. a hopper). The load of dry cement is placed into a second storage compartment of the bulk transport apparatus. The bulk transport apparatus is loaded onto transportation means with lifting means. The bulk transport apparatus is transported by the transportation means to the mixing site, which is at or convenient to the job site. The first mixture is discharged from the first storage means of the bulk transport apparatus into mixing means. Likewise, the dry cement is discharged from the second storage means of the bulk transport apparatus into the mixing means. The first mixture and cement are mixed with water to achieve the desired slurry properties and the concrete slurry is thereafter poured as desired. In this method, the bulk transport apparatus comprises the first storage compartment and the second storage compartment, where there is a water tight dividing means separating the first storage compartment and the second storage compartment. The first storage compartment has a first inlet for receiving the first mixture and a first outlet for discharging the first mixture. The second storage compartment has a second inlet for receiving the load of dry cement and a second outlet for discharging the load of dry cement. The bulk transport apparatus further comprises means for attachment of the apparatus to a lifting means. These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of one embodiment of the bulk transport apparatus. FIG. 2 is a front view of the embodiment of the bulk transport apparatus depicted in FIG. 1. FIG. 3 is a top view of the embodiment of the bulk transport apparatus depicted in FIG. 1. FIG. 4 is a cross-section taken along line 4-4 of FIG. 2. FIG. 5 shows the bulk transport apparatus loaded on a truck. FIG. 6 shows how the bulk transport apparatus may be lifted by a forklift. DETAILED DESCRIPTION OF THE EMBODIMENTS Referring now specifically to the drawings, FIGS. 1 through 6 show an embodiment 100 of the disclosed apparatus. This embodiment, hereinafter referred to as the hopper, comprises a shell 102 having an outside surface 104, an inside surface 106, a top 108 and a bottom 110. As generally shown in the drawings, the shell 102 may be in the approximate shape of an inverted pyramid having a generally rectangular top 108 and bounded by opposite-facing and matching sides 112. The sides 112 may taper inwardly as the sides 112 extend toward the bottom 110 as shown in FIG. 2. The back 114 of the shell may be substantially vertical as shown in FIG. 1, while the front 116 may taper inwardly as the front extends from the top 108 toward the bottom 110. While many materials may be used for shell 102, 3/16″ thick mild steel is an appropriate material. The hopper 100 may be constructed to hold different volumes of cement and aggregate, which typically will range from 3 to 5 cubic yards, or roughly a third to one half the volume of the commonly known cement truck. The shell 102 may be supported by various support members or structures attached to the outside surface 104 of the shell 102. For example, as shown in the drawings, the shell may be cradled within support structure 118. Support structure 118 comprises vertical legs 120 which are attached at the upper end of each vertical leg to cradle support 122. Cradle support 122 engages and supports shell 102. Cradle support 122 has openings 124 which are generally oriented outside of and parallel to sides 112. As shown in FIG. 6, openings 124 are of a dimension to receive the forks 126 of a lifting means, such as a forklift 128. Vertical legs 120 have feet 130 at the lower end of each leg to support the entire hopper 100. This configuration of the hopper 100 allows the device to be lifted by a forklift 128 onto transportation means, such as a flat bed truck 132, or alternatively, a railroad flat car or other conveyance for transportation to the desired job site. Alternatively, the hopper 100 may be lifted by a crane or boom, with lifting cables attached to lifting eyes 134. The lifting eyes 134 may also be used in conjunction with tie-downs to secure the hopper 100 to the flat bed truck 132. The hopper 100 comprises a first storage compartment 136 and a second storage compartment 138, which are defined by a water tight dividing means, such as dividing wall 140. The water tight dividing means keeps the fine and course aggregate separated from the cement, which is often necessary because the moisture content of the aggregate may be sufficiently high to initiate the hydration of the cement. The first storage compartment 136 is formed between the inside surface 106 of the shell 102 and dividing wall 140. A first inlet 142 extends through the top 108 of the shell 102 providing access into the first compartment 136. A first outlet 144 extending through the shell 102, provides an outlet at the bottom 110 of the shell for materials stored within the first storage compartment 136. The second storage compartment 138 is on the opposite side of dividing wall 140 from the first storage compartment 136. A second inlet 146 extends through the top 108 of the shell 102 providing access into second storage compartment 138. A second outlet 148 extends through shell 102, providing an outlet at the bottom 110 of the shell for materials stored within the second storage compartment 138. First inlet 142 and second inlet 146 may be respectively covered with first removable cover 150 and second removable cover 152. However, while the drawings show first inlet 142 being covered with first removable cover 150, it is to be appreciated that first inlet 142 does not necessarily require cover 150 and the first inlet may comprise the rectangular opening of top 108 excluding second inlet 146 and its supporting structure, thereby simplifying the loading of first storage compartment 136. In this configuration, a cover may be fabricated which simply fits over the first inlet 142. In common usage, first storage compartment 136 will be used to store a first mixture comprising a blend of fine aggregate and course aggregate. It may be most convenient to load the first storage compartment 136 through a first inlet 142 having a large cross-sectional area. For construction purposes, it may be advantageous for either the first storage compartment 136 or the second storage compartment 138 to comprise a vessel enclosed within shell 102. For example, the drawings generally depict second storage compartment 138 as a vessel 154. However, it is to be appreciated that the second storage compartment 138 may be formed simply by means of fabricating dividing wall 140 within shell 102, thereby defining two separate compartments. As generally shown in the drawings, vessel 154 may be generally cylindrical in shape, and may be tapered or finneled at the bottom 156 of the vessel. As shown in the drawings, first outlet 144 and second outlet 148 may coincide, such that one of the outlets is defined by the annulus formed between the shell 102 and the other outlet. For example, as shown in the drawings, first outlet 144 may comprise the annulus between shell 102 and second outlet 148. While first outlet 144 may be simply sealed with a plate, screwable cap or other sealing means, alternatively a first valve means may be used to allow for material to flow from the first storage compartment 136 through the first outlet 144 to the outside of the hopper 100. For example, as shown in FIGS. 1 and 2, first outlet 144 may be closed by gate 158 which may be disposed across first outlet 144 to contain materials within the first storage compartment 136, and pivotally retracted to allow materials to flow through the first outlet. While gate 158 may be operated manually, alternatively, as further shown in FIGS. 1 and 2, a first actuation means 160 may be used in conjunction with gate 158 to open and close the valve. The actuation means is an actuator of the type generally known in the art, which may be activated either pneumatically or hydraulicly. The air or hydraulic power source for the actuation means is of the type generally known in the art. Likewise, second outlet 148 may comprise a second valve means to allow material to flow from the second storage compartment 138 through the second outlet 148 to the outside of the hopper 100. For example, as shown schematically in FIGS. 1 and 2, second outlet 148 may be closed by butterfly valve 162, which may be rotated to either an open or closed position. Butterfly valve 162 may used in conjunction with a second actuation means 164 to either open or close the valve. The actuation means is of the type generally known in the art, and may be activated either pneumatically or hydraulicly. The air or hydraulic power source for the actuation means is of the type generally known in the art. The hopper 100 may further comprise means for vibrating different components of the apparatus. FIG. 1 shows vibrating unit 166 attached to vessel 154, although it should be appreciated that the same vibrating unit could be attached to various portions of shell 102 so as to vibrate the first storage compartment 136 or second storage compartment 138 in order to assist unloading of materials contained within either of the storage compartments. The vibrating unit may be of the pneumatic variety, such as those available from the ARNOLD COMPANY of Trenton, Ill. The hopper may also comprise weigh document storage means, such as lock box 168, which may be attached to either the outside surface of the shell 102 or to the support structure 118. The purpose of the document storage means is to store weigh documents which are prepared when the apparatus is loaded with the desired cement and aggregate components, where the respective weights of each component are determined at the cement plant and recorded on the documents. These documents thereafter accompany the concrete package contained within the hopper to the job site, where the documents may be referred to for control purposes and for determining the volume of water required for mixing the concrete slurry. A method for delivering a pre-weighed package for mixing concrete at a job site is realized using the hopper 100 described above. The pre-weighed package, which is prepared at the cement plant, comprises fine aggregate, course aggregate and dry cement. A first mixture is prepared which comprises a blend of fine aggregate and course aggregate. This first mixture is weighed and placed into one of the storage compartments of the hopper 100. For purposes of describing the method, it will be assumed that the first mixture is placed within the first storage compartment 136, although the second storage compartment 138 could also be used for storing the first mixture. A load of dry cement is weighed and placed within the other storage compartment of the hopper 100, which is assumed, for purposes of this example, to be the second storage compartment 138. The hopper is loaded onto transportation means, such as a flatbed truck 132, or a railroad flat car for delivery to the mixing site. A lifting means, such as forklift 128, is used to lift the hopper 100 onto the transportation means. It is to be appreciated that, depending upon the configuration of the cement plant, that the hopper 100 may be loaded either before or after it is loaded with the first mixture and/or the cement. Once loading of the hopper 100 has been completed and weigh documents generated, the hopper is transported to a mixing site, which should be conveniently located to the site where the mixed concrete is required. Mixing means, such a conventional cement mixing trucks or mixers may be used to receive the first mixture and cement from the hopper, which may be lifted by forklift 128 or other lifting means such that the first outlet 144 and second outlet 148 are positioned to discharge the first mixture and cement into the mixing means. Various admix may either be blended in with the first mixture at the cement plant when the first mixture is loaded into the hopper. Alternatively, the admix may be added with the mixing water to the first mixture and the cement. The admix may comprise any one or a combination of the following substances: water reducer, water replacer, accelerant, retardant, extender, shrinkage reducer, air entrainer, strengthener, and porosity reducer. While the above is a description of various embodiments of the present invention, further modifications may be employed without departing from the spirit and scope of the present invention. For example, the size, shape, and/or material of the various components may be changed as desired. Thus the scope of the invention should not be limited by the specific structures disclosed. Instead the true scope of the invention should be determined by the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates to a method and apparatus for delivery of concrete to a job site, and more particularly to a method and apparatus by which the dry components of a concrete mixture are prepared in pre-weighed packages at a cement plant, delivered to the job site in the apparatus, and thereafter the dry components are blended together, mixed with water, and used as needed or desired. The logistics of providing concrete for a construction project can be quite complicated. Concrete is a mixture of a “paste” and aggregate, where the aggregate is typically a blend of course aggregate (gravel) and fine aggregate (sand). The paste, composed of portland cement and water, coats the surface of the fine and coarse aggregates. The paste hardens and gains strength to form concrete, a rock-like mass. Concrete therefore has the trait of being plastic and malleable when newly mixed, but strong and durable when hardened. Other additives or “admixes” may be added to provide various properties to the concrete, including water reducer, accelerant, retardant, foaming agents, and other density control additives. Soon after the aggregate, water, and the cement are combined together as a slurry, the mixture starts to harden. During the chemical reaction of the cement with the water (i.e., hydration), a node forms on the surface of each cement particle. The node grows and expands until it links up with nodes from other cement particles or adheres to adjacent aggregates. This process results in the progressive stiffening and hardening of the slurry and the gradual development of strength in the slurry. Therefore, once the cement is placed into contact with water through the mixing of the slurry components, the concrete should be placed as desired before the slurry becomes too stiff to be properly placed. It is important that the proper ratios of course aggregate, fine aggregate, cement and water be used in preparing the concrete slurry. The concrete slurry must be sufficiently workable for proper placement in the construction application, yet the hardened concrete must possess the required durability and strength for the application. A mixture which does not have sufficient paste to fill the voids between the aggregate components will be difficult to place and will produce rough honey-combed surfaces and porous concrete. However, a mixture with excess paste will be smoother and easier to place, but it is subject to shrinkage and is more expensive. Therefore, the methods of providing concrete to a job site must maintain the proper proportions of each of the components of the concrete. There are generally three different known methods for providing concrete to a construction site. In the first method, pre-measured sacks of dry cement and aggregate are delivered to the job site, where the sack is opened and mixed with water to create the concrete slurry. This method has the advantage of allowing the slurry to be mixed shortly before placement, allowing substantial time for placement of the slurry before the concrete begins to stiffen. However, this method has the disadvantage of being costly and labor intensive. Individual sacks of dry concrete are more expensive than concrete purchased in bulk. In addition to the added expense for packaging and handling, the aggregate in sack concrete must have a very low moisture content to prevent the cement from prematurely hydrating within the sack. The sacks are heavy, difficult to handle, and must be individually opened and mixed. A 94 pound sack of dry concrete when mixed with approximately 6 gallons of water yields less than 5 cubic feet of concrete. It is to be appreciated that because a common cement truck holds 9.5 cubic yards of concrete slurry (i.e., approximately 256 cubic feet), one would have to mix over 50 individual sacks of cement to equal the volume of slurry delivered by a single cement truck. By way of example, a 4 inch thick 1800 square foot concrete pad requires over 22 cubic yards of concrete, requiring three cement trucks to deliver the concrete slurry. This same job would require mixing and placing approximately 120 sacks of cement. Because of these limitations, the sack method is generally limited to very small jobs. The second method of providing concrete to a construction site is perhaps the most commonly used. In this method, concrete slurry comprising aggregate, cement and water is placed into cement trucks at a cement plant, and the trucks thereafter deliver the slurry to the job site. There are several disadvantages of this method. The concrete slurry should be poured within 90 minutes from the time the cement and aggregate are mixed with water. Therefore, the distance of the job site from the cement plant can limit or prevent use of this method. If the truck is delayed by traffic or other reasons and the concrete slurry not placed within the required time window, the concrete slurry cannot be used and it becomes waste material. Not only is the concrete lost, but it must then also be transported to a proper disposal site. Typically, it is desired that concrete be delivered to the construction site first thing in the morning. Accordingly, demand for concrete at the cement plant is high in the early morning. A cement plant might have a capacity of loading 15 to 20 trucks per hour. Depending upon the demand, there may be congestion at the cement plant, with a large number of cement trucks idling and waiting for concrete. If a particular construction project has a large demand for concrete, the number of trucks required to deliver concrete can be large, consuming large amounts of fuel, and emitting pollutants. The third method of delivering concrete to a construction site is only practical for very large construction projects. This method is to set up a portable plant on the job site, with separate bulk storage for each of the concrete components. The components are thereafter weighed, blended and mixed on the job site as required for the construction. While this method has the advantage of providing concrete on an as-needed basis, it is prohibitively expensive except for large projects. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention is directed to an apparatus and method which meet the needs identified above for delivery of concrete to construction sites. A method for delivering a pre-weighed package comprising sand, aggregate and dry cement to a mixing site is disclosed. One embodiment of the method comprises the steps of preparing a first mixture comprising fine aggregate and course aggregate at an offsite plant. This first mixture is weighed. A load of dry cement is weighed. The first mixture is placed into a first storage compartment of a bulk transport apparatus (i.e. a hopper). The load of dry cement is placed into a second storage compartment of the bulk transport apparatus. The bulk transport apparatus is loaded onto transportation means with lifting means. The bulk transport apparatus is transported by the transportation means to the mixing site, which is at or convenient to the job site. The first mixture is discharged from the first storage means of the bulk transport apparatus into mixing means. Likewise, the dry cement is discharged from the second storage means of the bulk transport apparatus into the mixing means. The first mixture and cement are mixed with water to achieve the desired slurry properties and the concrete slurry is thereafter poured as desired. In this method, the bulk transport apparatus comprises the first storage compartment and the second storage compartment, where there is a water tight dividing means separating the first storage compartment and the second storage compartment. The first storage compartment has a first inlet for receiving the first mixture and a first outlet for discharging the first mixture. The second storage compartment has a second inlet for receiving the load of dry cement and a second outlet for discharging the load of dry cement. The bulk transport apparatus further comprises means for attachment of the apparatus to a lifting means. These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings. | 20040225 | 20070213 | 20050825 | 71982.0 | 0 | COOLEY, CHARLES E | METHOD AND APPARATUS FOR DELIVERY OF BULK CEMENT | SMALL | 0 | ACCEPTED | 2,004 |
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10,788,243 | ACCEPTED | LED forward voltage estimation in pulse oximeter | An apparatus and method for determining if a forward voltage of an LED in a pulse oximeter is within a predetermined range. This is accomplished by measuring the current through the LED, and also by knowing the duty cycle of the pulse width modulator (PWM) drive signal to the LED. | 1. A pulse oximeter comprising: at least one light emitting diode (LED) drive circuit; a current measuring circuit for measuring a current through said LED; a controller for generating a pulse width modulator (PWM) drive signal to said LED; and a processor, coupled to said controller and to said current measuring circuit, configured to determine if a forward voltage of said LED is within a predetermined range using a measurement of said current and said PWM signal. 2. The pulse oximeter of claim 1 wherein said processor is configured to provide an error signal if said forward voltage is outside said range. 3. The pulse oximeter of claim 1 wherein said processor is configured to compare said PWM drive signal to said measurement of said current to determine if the ratio is within an acceptable voltage range. 4. The pulse oximeter of claim 1 wherein said processor includes a proportional integral (PI) loop which generates said PWM signal from a current error signal reflecting a difference between said measurement of said current and a desired current. 5. A pulse oximeter comprising: at least one light emitting diode (LED) drive circuit; a current measuring circuit for measuring a current through said LED; a controller for generating a pulse width modulator (PWM) drive signal to said LED; a processor, coupled to said controller and to said current measuring circuit, configured to determine if a forward voltage of said LED is within a predetermined voltage range using a measurement of said current and said PWM signal, by comparing said PWM drive signal to said measurement of said current to determine if the ratio is within an acceptable voltage range; wherein said processor is configured to provide an error signal if said forward voltage is outside said voltage range; and wherein said processor includes a proportional integral (PI) loop which generates said PWM signal from a current error signal reflecting a difference between said measurement of said current and a desired current. 6. A method for operating a pulse oximeter comprising: providing a current using at least one light emitting diode (LED) drive circuit; measuring a current through said LED; generating a pulse width modulator (PWM) drive signal to said LED; and determining if a forward voltage of said LED is within a predetermined range using a measurement of said current and said PWM signal. 7. The method of claim 6 further comprising providing an error signal if said forward voltage is outside said range. 8. The method of claim 6 further comprising comparing said PWM drive signal to said measurement of said current to determine if the ratio is within an acceptable voltage range. 9. The method of claim 6 further comprising using a proportional integral (PI) loop to generate said PWM signal from a current error signal reflecting a difference between said measurement of said current and a desired current. 10. A method for operating a pulse oximeter comprising: providing a current using at least one light emitting diode (LED) drive circuit; measuring a current through said LED; generating a pulse width modulator (PWM) drive signal to said LED; determining if a forward voltage of said LED is within a predetermined voltage range using a measurement of said current and said PWM signal, by comparing said PWM drive signal to said measurement of said current to determine if the ratio is within an acceptable voltage range; providing an error signal if said forward voltage is outside said voltage range; and using a proportional integral (PI) loop to generate said PWM signal from a current error signal reflecting a difference between said measurement of said current and a desired current. | BACKGROUND OF THE INVENTION The present invention relates to oximeters, and in particular to controlling the LED voltage. Pulse oximetry is typically used to measure various blood chemistry characteristics including, but not limited to, the blood-oxygen saturation of hemoglobin in arterial blood, the volume of individual blood pulsations supplying the tissue, and the rate of blood pulsations corresponding to each heartbeat of a patient. Measurement of these characteristics has been accomplished by use of a non-invasive sensor which scatters light through a portion of the patient's tissue where blood perfuses the tissue, and photoelectrically senses the absorption of light in such tissue. The amount of light absorbed is then used to calculate the amount of blood constituent being measured. The light scattered through the tissue is selected to be of one or more wavelengths that are absorbed by the blood in an amount representative of the amount of the blood constituent present in the blood. The amount of transmitted light scattered through the tissue will vary in accordance with the changing amount of blood constituent in the tissue and the related light absorption. For measuring blood oxygen level, such sensors have typically been provided with a light source that is adapted to generate light of at least two different wavelengths, and with photodetectors sensitive to both of those wavelengths, in accordance with known techniques for measuring blood oxygen saturation. Known non-invasive sensors include devices that are secured to a portion of the body, such as a finger, an ear or the scalp. In animals and humans, the tissue of these body portions is perfused with blood and the tissue surface is readily accessible to the sensor. The light sources, typically light emitting diodes (LEDs), need to be driven with current to activate them. In order to determine sensor failure, such as an open or shorted LED, the current through the LED can be measured. Typically, this is done with a feedback resistor across which the voltage is measured to determine if any current is flowing. If no current is flowing, there is assumed to be an open connection. BRIEF SUMMARY OF THE INVENTION The present invention provides an apparatus and method for determining if a forward voltage of an LED in a pulse oximeter is within a predetermined range. This is accomplished by measuring the current through the LED, and also by knowing the duty cycle of the pulse width modulator (PWM) drive signal to the LED. In one embodiment, the determination of the forward voltage being within a predetermined range is done within a processor, which provides an error signal if the forward voltage is outside the range. The error signal could indicate, for example, a short or open connection in the LED sensor. In one embodiment, the processor includes a proportional integral (PI) loop which generates the PWM signal from an error signal corresponding to the difference between the actual current and desired current delivered to the LED. For a further understanding of the nature and advantages of the present invention, reference should be made to the following description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an oximeter incorporating the present invention. FIG. 2 is a circuit diagram of a LED drive circuit according to an embodiment of the present invention. FIGS. 3 and 4 are graphs illustrating the forward voltage versus current and PWM duty cycle versus power, respectively, for an LED in an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION Oximeter Front-End FIG. 1 illustrates an embodiment of an oximetry system incorporating the present invention. A sensor 10 includes red and infrared LEDs and a photodetector. These are connected by a cable 12 to a board 14. LED drive current is provided by an LED drive interface 16. The received photocurrent from the sensor is provided to an I-V interface 18. The IR and red voltages are then provided to a sigma-delta interface 20 incorporating the present invention. The output of sigma-delta interface 20 is provided to a microcontroller 22 which includes a 10-bit A/D converter. Microcontroller 22 includes flash memory for a program, and SRAM memory for data. The oximeter also includes a microprocessor 24 connected to a flash memory 26. Finally, a clock 28 is used and an interface 30 to a digital calibration in the sensor 10 is provided. A separate host 32 receives the processed information, as well as receiving an analog signal on a line 34 for providing an analog display. LED Drive Circuit FIG. 2 is a circuit diagram of the LED drive circuit according to an embodiment of the invention, which forms a portion of LED drive interface 16 of FIG. 1. A voltage regulator 36 provides a voltage separate from the voltage supply for the overall oximeter circuitry. The output is provided as a 4.5 volt signal on line 38, with the level being set by the feedback resistor divider of resistors R89 and R90. The voltage on line 38 is provided to a FET transistor Q11 to an inductor L6. The current through inductor L6 is provided by a switch 40 to one of capacitors C65 and C66, which store charge for the red and IR LEDs, respectively. A red/IR control signal on line 42 selects the switch position under control of the oximeter processor. A control signal LED PWM gate on line 44 controls the switching of transistor switch Q11. Once the capacitors are charged up, the control signal on line 44 turns off switch Q11 and current is provided from either capacitor C65 or C66, through switch 40 and inductor L6 to either the red anode line 46 or the IR anode line 48 by way of transistors Q5 and Q6, respectively. A signal “red gate” turns on transistor Q5, while its inverse, “/red gate” turns off transistor Q7. This provides current through the red anode line 46 to the back to back LEDs 50, with the current returning through the IR anode to transistor Q8 and through resistor R10 to ground. Transistor Q8 is turned on by the signal “/IR gate” while the inverse of this signal, “IR gate” turns off transistor Q6. The signals are reversed when the IR anode is to be driven, with the “IR gate” and “red gate” signals, and their inverses, changing state, so that current is provided through transistor Q6 to IR anode 48 and returns through red anode 46 and through transistor Q7 to resistor R10 and ground. The “LED current sense” signal is read for calibration purposes not relevant to the present invention. When the current from the capacitor C65 or C66 is provided through inductor L6 to the LEDs, and that current is switched off at the desired time, transistor Q11 is turned on so that the remaining current during the transition can be dumped into capacitor C64. This addresses the fact that the FET transistor switching is not instantaneous. Subsequently, C64 will dump its current through Q11 and inductor L6 into the capacitors when they are recharged. Resistor R38 and capacitor C67 are connected in parallel to inductor L6 to protect against signal spikes, and provide a smooth transition. Connected to inductor L6 is a sampling circuit with a switch 52 controlled by an LED sample hold signal on line 54 to sample the signals and provide them through an amplifier 56 to a “LED current” signal on line 58 which is read by the processor. An integrating capacitor C68 provides feedback for amplifier 56. A switch 60 responds to a “clear LED sample” signal to operate the switch to short out the capacitor between samples. Operational amplifier 56 operates between 4.5 volts and ground. Thus, a voltage reference slightly above ground, of 0.2 volts, is provided as a voltage reference on pin 3. The sample and hold circuit measures the voltage at node T18, between capacitor C69 and inductor L6, to determine the current. Capacitor C69 is 1/1000 of the value of capacitors C65 and C66. Thus, a proportional current is provided through C69, which is injected through switch 52 to integrating capacitor C68 to provide a voltage which can be measured at the output of amplifier 56 on line 58. The voltage measured by the processor on line 58 is used as a feedback, with the processor varying the width of the pulse delivered to transistor Q11 to selectively vary the amount of energy that's delivered to the capacitors 65 and 66, and then is eventually discharged to the LEDs 50. A PI (Proportional Integral) loop inside the processor then controls the PWM signal that controls Q11. This allows precise control of the LED intensity, allowing it to be maximized, if desired, without exceeding the desired limits. The lower left of the diagram shows a “4.5 v LED disable” signal which is used by the microprocessor to turn off the voltage regulator 36 in certain instances. For example, diagnostics looking for shorts in a new sensor plugged in may turn off the voltage regulator if there is a problem with the LED line. LED Voltage Determination FIGS. 3 and 4 illustrate the properties discovered by the present inventors which allowed development of the present invention. FIG. 3 is a graph of LED forward voltage versus LED current. The three different graphs produce three different lines with three different slopes for different types of loads: an IR LED, a red LED and a functional tester (SRC) which has a diode and a resistor in series. As can be seen, measuring the current alone does not indicate what the LED forward voltage is unless one also knows the type of load, and has stored a curve such as that shown in FIG. 3. FIG. 4 illustrates a plot of LED PWM duty cycle, which is the pulse width modulated drive signal for driving the LED. This is plotted on the vertical axis versus the power on a horizontal axis (LED voltage times LED current). As can be seen, for four different types of LED or SRC devices plotted, the plots are nearly identical with nearly identical slopes. From this recognition, the inventors determined that the voltage could be determined if one knows the PWM duty cycle and the current. The current is available from line 58 in FIG. 2, the LED current signal provided to the processor. The processor itself produces the PWM signal, and thus the processor has the two pieces of information needed to calculate the LED voltage for a particular LED, without knowing the type of LED. By using the information in FIG. 4, showing that the duty cycle is proportional by a constant to the power dissipated in the LED, a forward voltage can be derived. In one embodiment, the PWM signal is generated using a PI (proportional integral) loop. This loop takes the formal equation set forth below: y=Ae(t)+B∫e(t)dt where: A and B are constants e=error signal, difference between desired and actual current y=PWM signal In one embodiment, a PWM duty cycle generated by the processor is provided to a lookup table which stores the data in the graph of FIG. 4. The lookup table will produce the power dissipated as an output. This value can then be divided by the LED current as provided on line 58. The result of the division will be the forward voltage of the LED. Alternately, in another embodiment, a lookup table can be eliminated and a comparison can be done of the duty cycle and the current. Since the duty cycle is equal to the current times the voltage times a constant, upper and lower ranges for the ratio of duty cycle/LED current can be established to indicate conditions such as a short circuit or open connection in the LED. Alternately, a series of ranges could be used, with an outer range indicating the short or open condition, and an inner range, in one example, indicating the desired operating range for the LED. For example, the oximeter may need to drive the LED harder, near its maximum current, for certain patients with weak pulse signals. As will be understood by those with skill in the art, the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. For example, the determination of forward voltage could be done entirely in hardware, rather than in software in a processor. Accordingly, the foregoing description is intended to be illustrative, but not limiting, of the scope of the invention which is set forth in the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates to oximeters, and in particular to controlling the LED voltage. Pulse oximetry is typically used to measure various blood chemistry characteristics including, but not limited to, the blood-oxygen saturation of hemoglobin in arterial blood, the volume of individual blood pulsations supplying the tissue, and the rate of blood pulsations corresponding to each heartbeat of a patient. Measurement of these characteristics has been accomplished by use of a non-invasive sensor which scatters light through a portion of the patient's tissue where blood perfuses the tissue, and photoelectrically senses the absorption of light in such tissue. The amount of light absorbed is then used to calculate the amount of blood constituent being measured. The light scattered through the tissue is selected to be of one or more wavelengths that are absorbed by the blood in an amount representative of the amount of the blood constituent present in the blood. The amount of transmitted light scattered through the tissue will vary in accordance with the changing amount of blood constituent in the tissue and the related light absorption. For measuring blood oxygen level, such sensors have typically been provided with a light source that is adapted to generate light of at least two different wavelengths, and with photodetectors sensitive to both of those wavelengths, in accordance with known techniques for measuring blood oxygen saturation. Known non-invasive sensors include devices that are secured to a portion of the body, such as a finger, an ear or the scalp. In animals and humans, the tissue of these body portions is perfused with blood and the tissue surface is readily accessible to the sensor. The light sources, typically light emitting diodes (LEDs), need to be driven with current to activate them. In order to determine sensor failure, such as an open or shorted LED, the current through the LED can be measured. Typically, this is done with a feedback resistor across which the voltage is measured to determine if any current is flowing. If no current is flowing, there is assumed to be an open connection. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>The present invention provides an apparatus and method for determining if a forward voltage of an LED in a pulse oximeter is within a predetermined range. This is accomplished by measuring the current through the LED, and also by knowing the duty cycle of the pulse width modulator (PWM) drive signal to the LED. In one embodiment, the determination of the forward voltage being within a predetermined range is done within a processor, which provides an error signal if the forward voltage is outside the range. The error signal could indicate, for example, a short or open connection in the LED sensor. In one embodiment, the processor includes a proportional integral (PI) loop which generates the PWM signal from an error signal corresponding to the difference between the actual current and desired current delivered to the LED. For a further understanding of the nature and advantages of the present invention, reference should be made to the following description taken in conjunction with the accompanying drawings. | 20040225 | 20061010 | 20050825 | 91768.0 | 0 | BERHANU, ETSUB D | LED FORWARD VOLTAGE ESTIMATION IN PULSE OXIMETER | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,788,303 | ACCEPTED | Anti-pilfering device for a vending machine | A vending machine includes a storage/display region, a dispensing chamber including a product access opening, and an anti-pilfer device that prevents unauthorized removal of products from the storage/display region through the product access opening. A delivery door is provided which can be shifted from a closed position to an open position to enable the removal of products from the dispensing chamber. The anti-pilfer device includes a plate coupled to a lower portion of the delivery door. When the delivery door is moved from the closed position, the anti-pilfer plate shifts, over a guide element, into a position that prevents products from being withdrawn from the storage/display area. Preferably, the storage/display region and dispensing chamber are separated by a product door, with the anti-pilfer plate preventing the product door from opening when the delivery door is shifted from the closed position. | 1. A vending machine comprising: a product storage area; a dispensing chamber in communication with the product storage area, said dispensing chamber including a product access opening for removal of products transferred to the dispensing chamber from the product storage area; a delivery door having an upper portion and a lower portion, with the upper portion being pivotally mounted adjacent the product access opening such that said delivery door is shiftable between a closed position, wherein the delivery door substantially covers the product access opening, and an open position, wherein products can be readily accessed and removed from the dispensing chamber; and an anti-pilfer plate pivotally mounted to the lower portion of the delivery door, said anti-pilfer plate being shiftable from a first position, wherein the anti-pilfer plate enables free passage of products from the product storage area to the dispensing chamber when the delivery door is in the closed position, to a second position, wherein passage of products from the product storage area to the dispensing chamber is prevented when the delivery door is shifted from the closed position. 2. The vending machine according to claim 1, further comprising: a product door pivotally mounted between the product storage area and the dispensing chamber, said product door being shifted from a closed position to an open position by passage of a product into the dispensing chamber. 3. The vending machine according to claim 2, further comprising: a delivery chute interposed between the product storage area and the product door for directing a product from the product storage area to the dispensing chamber. 4. The vending machine according to claim 3, wherein the product door closes off the delivery chute. 5. The vending machine according to claim 3, further comprising: a seal interposed between the product door and the delivery chute, said seal being adapted to isolate the product storage area from the dispensing area when the product door is in the closed position. 6. The vending machine according to claim 5, wherein the seal is carried by the product door. 7. The vending machine according to claim 3, wherein the anti-pilfer plate blocks the product door from being shifted from the closed position to the open position when the delivery door is shifted to the open position. 8. The vending machine according to claim 1, further comprising: a guide element for directing the anti-pilfer plate between the first and second positions. 9. The vending machine according to claim 8, wherein the guide element is constituted by a rod projecting substantially perpendicularly from a side portion of the dispensing chamber, said anti-pilfer plate being guided upon the rod. 10. The vending machine according to claim 1, wherein the vending machine is constituted by a glass-front vending machine. 11. The vending machine according to claim 1, wherein the anti-pilfer plate projects from the lower portion of the delivery door upwardly and rearwardly into the dispensing chamber. 12. A method of preventing pilfering of products from a vending machine comprising: shifting a product access door, having an upper portion and a lower portion, from a closed position to an open position to access a product dispensing chamber; and simultaneously moving an anti-pilfer plate pivotally mounted to the lower portion of the product access door from a first position, wherein a passage extending between a product storage area and the dispensing chamber is unobstructed to allow passage of a vended product to the dispensing chamber, to a second position, wherein the passage between the product storage area and the dispensing chamber is blocked. 13. The method of claim 12, wherein the anti-pilfer plate blocks a product door, interposed between the product storage area and the dispensing chamber, when the anti-pilfer plate is moved from the first position to the second position. 14. The method according to claim 12, further comprising: guiding the anti-pilfering plate for movement between the first and second positions upon a guide element provided in the dispensing chamber. 15. The method according to claim 14, further comprising: sliding the anti-pilfering plate upon the guide element. 16. A vending machine comprising: a product storage area; a dispensing chamber in communication with the product storage area, said dispensing chamber including a product access opening for removal of products transferred to the dispensing chamber from the product storage area; a delivery door pivotally mounted adjacent the product access opening for rotation about a pivot axis, said delivery door being shiftable between a closed position, wherein the delivery door substantially covers the product access opening, and an open position, wherein products can be readily accessed and removed from the dispensing chamber; and an anti-pilfer plate pivotally mounted to the delivery door at a position spaced from the pivot axis, said anti-pilfer plate being shiftable from a first position, wherein the anti-pilfer plate enables free passage of products from the product storage area to the dispensing chamber when the delivery door is in the closed position, to a second position, wherein passage of products from the product storage area to the dispensing chamber is prevented when the delivery door is shifted from the closed position. 17. The vending machine according to claim 16, further comprising: a product door arranged between the product storage area and the dispensing chamber, said product door being adapted to be shifted from a closed position to an open position by passage of a product into the dispensing chamber, wherein the anti-pilfer plate blocks the product door from being shifted from the closed position to the open position when the delivery door is shifted to the open position. 18. The vending machine according to claim 17, further comprising: a guide element for directing the anti-pilfer plate between the first and second positions. 19. The vending machine according to claim 18, wherein the guide element is constituted by a rod upon which the anti-pilfer plate is guided for movement between the first and second positions. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention pertains to the art of vending machines and, more particularly, to an anti-pilfering device that prevents unauthorized removal of products from a vending machine. 2. Discussion of the Prior Art Certain types of vending machines include a glass front that covers a storage/display region. After a consumer makes a selection and deposits currency into an appropriate receptacle, the selected product is moved from the storage/display region to a dispensing chamber of the vending machine. Typically, the dispensing chamber is accessed through a product delivery door provided on a bottom, front portion of the vending machine. In order to retrieve the selected product, the consumer must push the product delivery door open. Generally, the product delivery door is hinged at an upper portion and coupled to an anti-pilfer device. As the door is opened, a mechanism, interconnecting the door and the anti-pilfer device, causes the anti-pilfer device to close off access to the storage/display region. The mechanism moves the anti-pilfer device quickly so that opening the product delivery door will begin to shift a plate or door to completely cut-off access to the storage/display region. However, in many cases, opening the product delivery door slightly will provide enough room for a tool to be inserted up into the storage/display section to remove a product. In addition, and particularly in the area of beverage vending machines, it is becoming increasingly difficult to provide a dispensing chamber large enough to accommodate the increased size of product containers while, at the same time, providing an anti-pilfer mechanism that moves quickly using very little force. Based on the above, there still exists a need in the art for a fully effective anti-pilfering device for a vending machine. More specifically, there exists a need for an anti-pilfering device for a vending machine having a large dispensing chamber that can be quickly shifted into a position that prevents unauthorized access to product using minimal activating force. SUMMARY OF THE INVENTION The present invention is directed to a vending machine including a product storage area, a dispensing chamber in communication with the product storage area, and a product access opening for removal of products transferred to the dispensing chamber from the product storage area. A delivery door is pivotally mounted to an upper edge of the product access opening. More specifically, the delivery door is adapted to shift from a closed position to an open position to facilitate the removal of products from the dispensing chamber. In accordance with a preferred embodiment of the present invention, an anti-pilfer plate is coupled to a lower portion of the delivery door. When the delivery door is shifted from the closed position, the anti-pilfer plate shifts into a position that prevents products from being withdrawn from the storage area. In further accordance with the invention, a product door is pivotally mounted between the product storage area and the dispensing chamber. Preferably, the product door includes a seal provided about the product door to prevent the passage of refrigerated air from the storage area into the dispensing chamber. The product door is arranged so that, when the delivery door is moved from the closed position, the anti-pilfer plate shifts into a position so as to prevent the product door from opening. In still further accordance with the invention, the anti-pilfer plate is directed into the position that prevents unauthorized access to the product storage area through the use of at least one guide element projecting from at least one side wall of the dispensing chamber. The anti-pilfer plate projects from a bottom edge portion of the delivery door and rests upon the guide elements. When the product door is moved from the closed position, the anti-pilfer plate is directed over the guide elements into a position that prevents unauthorized retrieval of stored products. Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of a preferred embodiment when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevational view of a vending machine including an anti-pilfer device constructed in accordance with the present invention; FIG. 2 is a partial, cross-sectional view of a dispensing chamber of the vending machine of FIG. 1, showing the anti-pilfer in a first or product dispensing position; FIG. 3 is a partial, cross-sectional view of the dispensing chamber of FIG. 2, showing the anti-pilfer plate moving from the product dispensing position; and FIG. 4 is a partial, cross-sectional view of the dispensing chamber of FIG. 2, showing the anti-pilfer plate in a second or anti-pilfer position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT With initial reference to FIG. 1, a vending machine generally indicated at 2 includes a cabinet frame 4. As shown, cabinet frame 4 includes top, bottom and opposing side walls 6-9. Arranged below bottom wall 7 are a pair of leg members 10 and 11 for positioning vending machine 2 upon a supporting surface (not shown). In the preferred embodiment shown, vending machine 2 is divided into a plurality of zones for performing various functions associated with the delivery of products to a consumer. Toward that end, vending machine 2 includes a storage and display zone 14, a currency receiving zone 15 and a dispensing zone 16. In the embodiment shown, storage/display zone 14 is provided with a plurality of product support shelves 20-24 for supporting and displaying a plurality of product containers, one of which is indicated at 26. Each of the plurality of product support shelves 20-24 includes an associated plurality of dispensing mechanisms (not shown) for delivering each product container 26 from storage/display zone 14 to dispensing zone 16. The actual construction and operation of the dispensing mechanisms does not constitute part of the present invention. Instead, various known dispensing mechanisms could be employed, including that set forth in detail in commonly assigned U.S. Pat. No. 6,571,988 entitled “Article Release Mechanism For a Vending Machine” issued on Jun. 3, 2003. Again, it should be understood that various other dispensing mechanisms could be employed, such as coils for prepackaged food items. In a manner known in the art, storage/display zone 14 is provided with a door 28 having a glass panel 29 to enable a consumer to view and choose between the variety of product containers 26 carried within vending machine 2. In accordance with the embodiment shown, dispensing zone 16 is arranged below storage/display zone 14 and includes a dispensing chamber 37 having a plurality of product access openings 39 and 40 that enable the consumer to remove a dispensed product from dispensing chamber 37. As will be discussed more fully below, product access openings 39 and 40 are provided with delivery doors 43 and 44 respectively, which are pivotally mounted to dispensing chamber 37 so as to be shiftable between a first position, effectively closing off product access openings 39 and 40, and a second position, enabling the retrieval of a dispensed product from dispensing chamber 37. Arranged alongside storage/display zone 14 and dispensing zone 16 is currency receiving zone 15. In the embodiment shown, currency receiving zone 15 includes a currency receiving center 50 for inputting and storing currency deposited by the consumer during a vend transaction. Currency receiving center 50 includes a bill acceptor/validator 52, a multi-price coin mechanism 53 and a key pad 55 for inputting particular product selections. Currency receiving center 50 also includes a display 57 for providing information to the consumer, as well as validating the particular selection made. Finally, a coin return slot 59 is provided for returning any required change to the consumer at the completion of a vend operation. Reference will now be made to FIGS. 2-4 in describing further details of dispensing zone 16, and particularly dispensing chamber 37. Once a product container 26 is released from one of the plurality of product support shelves 20-24, the product container 26 falls, under the force of gravity, into a delivery chute 70 that opens into dispensing chamber 37. As shown, a product door 72 is pivotally mounted across delivery chute 70 so as to isolate storage/display zone 14 from dispensing zone 16. Toward that end, a seal 73 is arranged around an outer periphery of product door 72 so that refrigerated air, if present in storage/display zone 14, will not pass through delivery chute 70 into dispensing chamber 37. With this construction, product container 26 passing through delivery chute 70 will open product door 72 and pass into dispensing chamber 37. Once product container 26 has passed through delivery chute 70, product door 72 will close, either under the force of gravity or through the use of a biasing spring (not shown), to once again close off delivery chute 70. In order to retrieve a vended product from dispensing zone 16, a consumer must access dispensing chamber 37 through, for example, delivery door 43. In accordance with a preferred form of the invention, delivery door 43 includes a first end 80 that extends to a second end 81 through an intermediate portion 83. First end 80 is pivotally mounted to an upper portion of delivery chamber 37 through a hinge 85, with second end 81 overlapping a lower lip portion 86 of product access opening 39 so that intermediate portion 83 effectively closes off dispensing chamber 37 as represented in FIG. 2. Without the present invention, after opening delivery door 43, a consumer could access, either manually or by using a tool, dispensing chamber 37 and retrieve product containers 26 from storage/display zone 14 without inserting or depositing currency into currency receiving center 50. Therefore, in accordance with the present invention, vending machine 2 is provided with an anti-pilfer plate 100 arranged so as to prevent unauthorized access to storage/display zone 14. In accordance with the most preferred form of the present invention, anti-pilfer plate 100 includes a first end 103 pivotally mounted to second end 81 of delivery door 43 through a hinge mechanism 104. First end 103 leads to a second end 106 through an intermediate or blocking portion 108. When delivery door 43 is closed, anti-pilfer plate 100 enables free passage of product container(s) 26 into dispensing chamber 37 as represented in FIG. 2. Once delivery door 43 moves from the closed position, anti-pilfer plate 100 moves in unison into a second or product blocking position as represented from FIG. 3 to FIG. 4. That is, anti-pilfer plate 100 is directed over a guide element 114 such that second end 106 and blocking portion 108 prevent unauthorized access to storage/display zone 14. In accordance with one aspect of the invention, guide element 114 is constituted by a rod that projects generally perpendicularly from a side portion 120 of dispensing chamber 37. In still further accordance with the most preferred form of the present invention, anti-pilfer plate 100, when moved into the blocking position, actually prevents product door 72 from opening thus providing an even more restricted access to storage/display zone 14. With this particular construction, once delivery door 43 is moved from the closed position, unauthorized access to storage/display zone 14 is prevented. More specifically, the path traveled by a particular product container 26 from storage/display zone 14 into dispensing zone 16 is completely blocked so that either insertion of an arm or a tool is completely restricted. As described, an anti-pilfering device constructed in accordance with the present invention will provide a mechanism that effectively seals off a storage region of a vending machine to prevent unauthorized access to products stored therein. Moreover, the anti-pilfering device will not only prevent entry of a hand or arm, but tools will be unable to pass into and retrieve products from the vending machine. Although described with reference to a preferred embodiment of the present invention, it should be readily apparent to one of ordinary skill in the art that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For instance, the present invention can also be readily employed in solid front or other types of vending machines, including machines which employ mechanisms to transfer products to a dispensing region instead of relying on gravity. In addition, while the vending machine is depicted as having two product access openings, the anti-pilfer plate arrangement can work with any number of openings provided in the vending machine. In general, the invention is only intended to be limited to the scope of the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention pertains to the art of vending machines and, more particularly, to an anti-pilfering device that prevents unauthorized removal of products from a vending machine. 2. Discussion of the Prior Art Certain types of vending machines include a glass front that covers a storage/display region. After a consumer makes a selection and deposits currency into an appropriate receptacle, the selected product is moved from the storage/display region to a dispensing chamber of the vending machine. Typically, the dispensing chamber is accessed through a product delivery door provided on a bottom, front portion of the vending machine. In order to retrieve the selected product, the consumer must push the product delivery door open. Generally, the product delivery door is hinged at an upper portion and coupled to an anti-pilfer device. As the door is opened, a mechanism, interconnecting the door and the anti-pilfer device, causes the anti-pilfer device to close off access to the storage/display region. The mechanism moves the anti-pilfer device quickly so that opening the product delivery door will begin to shift a plate or door to completely cut-off access to the storage/display region. However, in many cases, opening the product delivery door slightly will provide enough room for a tool to be inserted up into the storage/display section to remove a product. In addition, and particularly in the area of beverage vending machines, it is becoming increasingly difficult to provide a dispensing chamber large enough to accommodate the increased size of product containers while, at the same time, providing an anti-pilfer mechanism that moves quickly using very little force. Based on the above, there still exists a need in the art for a fully effective anti-pilfering device for a vending machine. More specifically, there exists a need for an anti-pilfering device for a vending machine having a large dispensing chamber that can be quickly shifted into a position that prevents unauthorized access to product using minimal activating force. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention is directed to a vending machine including a product storage area, a dispensing chamber in communication with the product storage area, and a product access opening for removal of products transferred to the dispensing chamber from the product storage area. A delivery door is pivotally mounted to an upper edge of the product access opening. More specifically, the delivery door is adapted to shift from a closed position to an open position to facilitate the removal of products from the dispensing chamber. In accordance with a preferred embodiment of the present invention, an anti-pilfer plate is coupled to a lower portion of the delivery door. When the delivery door is shifted from the closed position, the anti-pilfer plate shifts into a position that prevents products from being withdrawn from the storage area. In further accordance with the invention, a product door is pivotally mounted between the product storage area and the dispensing chamber. Preferably, the product door includes a seal provided about the product door to prevent the passage of refrigerated air from the storage area into the dispensing chamber. The product door is arranged so that, when the delivery door is moved from the closed position, the anti-pilfer plate shifts into a position so as to prevent the product door from opening. In still further accordance with the invention, the anti-pilfer plate is directed into the position that prevents unauthorized access to the product storage area through the use of at least one guide element projecting from at least one side wall of the dispensing chamber. The anti-pilfer plate projects from a bottom edge portion of the delivery door and rests upon the guide elements. When the product door is moved from the closed position, the anti-pilfer plate is directed over the guide elements into a position that prevents unauthorized retrieval of stored products. Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of a preferred embodiment when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views. | 20040301 | 20070904 | 20050922 | 59269.0 | 0 | BOLLINGER, DAVID H | ANTI-PILFERING DEVICE FOR A VENDING MACHINE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,788,427 | ACCEPTED | Exchangeable keymat | A communication device comprising a keymat, a cover, and a substrate comprising a plurality of key switches is disclosed. The keymat comprises a plurality of lips located at the edges of the keymat. The cover comprises a plurality of indentations configured to receive the plurality of lips. The indentations are located at the edges of a recess for removably mounting the keymat. | 1. A communication device comprising a keymat, a cover, and a substrate comprising a plurality of key switches, wherein, said keymat comprises a plurality of lips located at edges of said keymat, and said cover comprises a plurality of indentations configured to receive said plurality of lips, wherein said indentations are located at edges of a recess for removably mounting said keymat. 2. Communication device according to claim 1, wherein said keymat comprises one or more guiding pieces, and said cover comprises one or more corresponding guiding recesses. 3. Communication device according to claim 2, wherein said guiding pieces are arranged in direct connection to one or more of said plurality of lips. 4. Communication device according to claim 1, wherein said keymat comprises one or more guiding recesses, and said cover comprises one or more corresponding guide pieces. 5. Communication device according to claim 4, wherein said guiding pieces comprises one or more ribs extending to be received by said guide pieces. 6. A cover for a communication device comprising a recess for receiving a keymat comprising a plurality of lips, comprising a plurality of indentations located at the edges of said recess for receiving said plurality of lips. 7. Cover according to claim 6, further comprising one or more guiding recesses. 8. Cover according to claim 7, wherein said one or more guiding recesses are arranged in direct connection to one or more of said plurality of indentations. 9. Cover according to claim 6, further comprising one or more guiding pieces. 10. Cover according to claim 9, wherein said guiding pieces are one or more ribs on a surface of said cover facing a place where a keymat is to be mounted. 11. A keymat for removable mounting on a cover of a communication device, comprising lips located at edges of said keymat configured to insert into indentations of said cover. 12. Keymat according to claim 11, further comprising one or more guiding pieces. 13. Keymat according to claim 12, wherein said guiding pieces are arranged in direct connection to one or more of said plurality of lips. 14. Keymat according to claim 11, further comprising one or more guiding recesses. 15. Keymat according to claim 14, wherein said one or more guiding recesses are an incision in a surface that is to be in contact with said cover when mounted on said cover. 16. Keymat according to claim 11, being moulded in one piece. | FIELD OF INVENTION The present invention relates to a communication device with an on a cover exteriorly attachable keymat, a cover for an exteriorly attachable keymat, and an exteriorly attachable keymat. BACKGROUND OF INVENTION It has become desirable for users of radiotelephones to replace a cover of the radiotelephone easily without requiring any special training or tools. Telephone handsets with exchangeable covers are known, e.g. from EP 1028574 A2. EP 1028574 A2 discloses a radio telephone comprising a front and a back cover. The radio telephone further comprises an inner housing retaining electronic components of the radiotelephone. FIG. 1 shows a prior art radiotelephone 1 with a front cover 2, a back cover 3, an inner housing 4, and a keymat 5. To assemble the radiotelephone 1, the front and back covers 2, 3 are attached to mutual sides of the inner housing 4. The keymat 5 is sandwiched between the front cover 2 and the inner housing 4 such that keys 6 of the keymat 5 extend through holes 7 in the front cover 2 and, when a key is pressed, actuate key switches (not shown) on the inner housing 4. The main purpose of the keymat is to act as an interface between the user and the functions of the radiotelephone. A problem with known technology is that a change of keymat require that the front cover is removed from the internal housing. Another problem is that the front cover limits the freedom to design the keys of the keymat, since the keys have to fit the holes of the front cover. U.S. 2003/0201983 discloses a keymat for use with a mobile station. The keymat includes a web for interconnecting a plurality of keys. The keymat is attached externally on a cover of the mobile station to permit a user to exchange the keymat for another. A plurality of key pins extends through openings in the cover of the mobile station. The keymat has retaining means for removably retaining the keymat to the mobile station. The retaining means are either key pins integrally formed with the keymat and extending inwardly through openings in the cover of the mobile station and provided with extensions on the key pins to engage the interior surface of the cover, or recesses in the keymat for receiving the key pins, or a slide plate disposed inward of the cover for engaging a keymat fixedly attached to a plurality of key pins that forms a recess for engaging the slide plate. A problem with this solution is that the edges of the keymat is unprotected and not tightly attached to the cover, and may cause that the keymat is ripped off the cover during every day use, such as keeping the mobile station in a pocket or bag. Another problem with this solution is that attachment and removal are difficult. Further, a problem with this solution is that, when removing the keymat, the stress on the extensions for retaining the keymat many times will cause that the extensions are torn off, and it will not be possible to re-attach the keymat. SUMMARY OF THE INVENTION An object of the present invention is to overcome at least a part of the above stated problems. The above object, together with numerous other objects, which will become evident from the detailed description below, is obtained according to a first aspect of the present invention by a communication device comprising a keymat, a cover, and a substrate comprising a plurality of key switches, wherein the keymat is exteriorly attachable on the cover, and keypins of said keymat extend through holes of said cover towards said plurality of key switches, wherein the keymat comprises a plurality of lips located at the edges of the keymat, and the cover comprises a plurality of indentations configured to receive the plurality of lips, wherein the indentations are located at the edges of a recess for removably mounting the keymat. The keymat may comprise one or more guiding pieces, and the cover may comprise one or more corresponding guiding recesses. The guiding pieces may be arranged in direct connection to one or more of the plurality of lips. The keymat may be provided with one or more guiding recesses, and the cover may be provided with one or more corresponding guide pieces. The guiding pieces may be one or more ribs extending to be received by the guide pieces. The above object, together with numerous other objects, which will become evident from the detailed description below, is obtained according to a second aspect of the present invention by a cover for a communication device comprising a recess for receiving a keymat comprising a plurality of lips, wherein the recess is provided with a plurality of indentations located at the edges of the recess for receiving the plurality of lips. The cover may further comprise one or more guiding recesses. The one or more guiding recesses may be arranged in direct connection to one or more of said plurality of indentations. The cover may further comprise one or more guiding pieces. The guiding pieces may be one or more ribs on a surface of the cover facing a place where a keymat is to be mounted. The above object, together with numerous other objects, which will become evident from the detailed description below, is obtained according to a third aspect of the present invention by a keymat for removable mounting on a cover of a communication device, comprising lips located at the edges of the keymat. The lips are configured to insert into indentations of said cover. The keymat may further comprise one or more guiding pieces. The guiding pieces may be arranged in direct connection to one or more of said plurality of lips. The keymat may further comprise one or more guiding recesses. Said one or more guiding recesses may be an incision in a surface that is to be in contact with a cover when mounted on the cover. The keymat may be moulded in one piece. A particular feature of the present invention relates to the possibility to mount, demount, and remount the keymat without any tools or training. A particular advantage of the present invention is easier mounting, demounting, and remounting of a keymat since the cover do not have to be removed. Further, an advantage of the invention is that the retaining of the keymat is improved, and the risk for unintentional removal of the keymat during wearing and using the communication device is decreased. Another advantage of the present invention is that a designer has more freedom in designing different keymats, and the user has more freedom in changing keymats. Another advantage of the present invention is a more attractive appearance, since the recess of the cover enables the keymat to be in level of the cover. Another advantage of the present invention is reduced costs since the exchangeable keymat can be moulded in one piece, and material can be saved. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a telephone according to prior art. FIG. 2 shows a communication device according to the present invention. FIG. 3 shows an embodiment according to the present invention. FIG. 4a and 4b are views of a front cover with a mounted keymat seen from opposite sides, respectively. FIG. 5 shows a cross section view of an embodiment of the present invention. FIG. 6 shows a cross section view of an embodiment of the present invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 2 shows a communication device 100 which is provided with a plurality of parts, e.g. a processor (not shown), radio electronics (not shown), a substrate (not shown), a microphone 104, a speaker 106, a display 108 and a plurality of key switches (not shown). The communication device 100 is also provided with a front cover 102, a back cover (not shown) and a keymat 110. FIG. 3 shows a front cover 202 and a keymat 206 according to an embodiment of the present invention, wherein the front cover 202 is provided with a recess 204 to receive the keymat 206. The keymat 206 is preferably made of rubber or any elastomer. The keymat 206 is provided with a plurality of lips 208, 210, 212, 214 that enables a removable mounting of the key mat 206 on the front cover 202. The keymat 206 is mounted by bending the keymat 206 slightly and putting it into the recess 204, and the elastic properties of the keymat 206 will force the lips into corresponding indentations of the front cover 202. Similarly, the keymat 206 is demounted by bending the keymat 206 slightly and lifting it out of the recess 204. The keymat 206 is also provided with a guide piece 216 that enables guiding the keymat 206 to a correct position at the front cover 202. The guide piece 216 is received by a corresponding guide recess in the front cover 202. FIG. 4a is a front view of a front cover 302 with a mounted keymat 304. When the keymat 304 is mounted in the front cover 302, the lips are not visible, and an attractive appearance is achieved. A designer now has the ability to design the keypad with the keys 306 of the keymat 304 more freely. FIG. 4b is a view of the front cover 302 with the mounted keymat 304 from the opposite side compared to FIG. 4a. A plurality of pressure transmitters 308, one for each key 306 of the keymat 304, protrudes through a plurality of holes 310 in the front cover 302, thereby enabling actuation of a plurality of key switches of a communication device. The pressure transmitters 308 are bosses formed when moulding the keymat 304. Guide pieces 312, 314 guide the keymat 304 to a correct position by fitting into recesses 316, 318 of the front cover 302. The guide pieces 312, 314 are flanges extending from the surface of the keymat 304 facing the cover 302, through the recesses 316, 318, when the keymat 304 is attached to the cover 302. Lips 320, 322, 324, 326, 328, 330, 332 of the keymat 304 insert into indentations of the front cover 302 to hold the keymat 304 without adhesive, glue, tape, or other mounting means. Preferably, the guide pieces 312, 314 are arranged in direct contact with some of the snap connectors 320, 322. FIG. 5 shows a cross section view of a front cover 402 and a keymat 404 according to an embodiment of the present invention. The front cover 402 is shown with the mounted keymat 404. The front cover 402 is provided with a guide piece 406, that is received by a guiding recess 408 in the keymat 404 to ensure a correct positioning of the keymat 404. The guide piece 406 is a rib on the surface facing the keymat 404 and the guide recess 408 is an incision in the surface facing the cover 402. The keymat is provided with lips 410, 412 that are received by indentations 414, 416 in the front cover 402 to hold the keymat 404 without adhesive, glue, tape, or other mounting means. FIG. 6 shows a cross section view of a front cover 502 and a keymat 504 according to an embodiment of the present invention. The front cover 502 is shown with the mounted keymat 504. The keymat is provided with lips 506, 508 that are received by indentations 510, 512 in the front cover 502 to hold the keymat 504 without adhesive, glue, tape, or other mounting means. The front cover 502 is further provided with locking parts 514, 516 that forces the lips 506, 508 of the keymat 504 into the indentations 510, 512 of the front cover 502 to improve gripping pressure. The front cover 502 is provided with a plurality of holes 518, 520, 522 to enable pressure transmitters 524, 526, 528 to protrude through the front cover 502 to reach key switches located on a substrate of the communication device (not shown). The keymat 504 is provided with a plurality of keys 530, 532, 534. When one of the keys 530, 532, 534 is pressed, the corresponding pressure transmitter 524, 526, 528 displaces and actuates the corresponding key switch (not shown). In the above presented embodiments of the present invention, a keymat is mounted on a front cover. It is the most common design of a communication device to locate a keypad on the front of the communication device. However, a keypad can be located on a back cover, on a cover of a tiltable and/or swivable part where the terms “front” and “back” are not applicable, or anywhere on a cover of the communication device. Therefore, the invention is applicable on any cover used for a communication device. | <SOH> BACKGROUND OF INVENTION <EOH>It has become desirable for users of radiotelephones to replace a cover of the radiotelephone easily without requiring any special training or tools. Telephone handsets with exchangeable covers are known, e.g. from EP 1028574 A2. EP 1028574 A2 discloses a radio telephone comprising a front and a back cover. The radio telephone further comprises an inner housing retaining electronic components of the radiotelephone. FIG. 1 shows a prior art radiotelephone 1 with a front cover 2 , a back cover 3 , an inner housing 4 , and a keymat 5 . To assemble the radiotelephone 1 , the front and back covers 2 , 3 are attached to mutual sides of the inner housing 4 . The keymat 5 is sandwiched between the front cover 2 and the inner housing 4 such that keys 6 of the keymat 5 extend through holes 7 in the front cover 2 and, when a key is pressed, actuate key switches (not shown) on the inner housing 4 . The main purpose of the keymat is to act as an interface between the user and the functions of the radiotelephone. A problem with known technology is that a change of keymat require that the front cover is removed from the internal housing. Another problem is that the front cover limits the freedom to design the keys of the keymat, since the keys have to fit the holes of the front cover. U.S. 2003/0201983 discloses a keymat for use with a mobile station. The keymat includes a web for interconnecting a plurality of keys. The keymat is attached externally on a cover of the mobile station to permit a user to exchange the keymat for another. A plurality of key pins extends through openings in the cover of the mobile station. The keymat has retaining means for removably retaining the keymat to the mobile station. The retaining means are either key pins integrally formed with the keymat and extending inwardly through openings in the cover of the mobile station and provided with extensions on the key pins to engage the interior surface of the cover, or recesses in the keymat for receiving the key pins, or a slide plate disposed inward of the cover for engaging a keymat fixedly attached to a plurality of key pins that forms a recess for engaging the slide plate. A problem with this solution is that the edges of the keymat is unprotected and not tightly attached to the cover, and may cause that the keymat is ripped off the cover during every day use, such as keeping the mobile station in a pocket or bag. Another problem with this solution is that attachment and removal are difficult. Further, a problem with this solution is that, when removing the keymat, the stress on the extensions for retaining the keymat many times will cause that the extensions are torn off, and it will not be possible to re-attach the keymat. | <SOH> SUMMARY OF THE INVENTION <EOH>An object of the present invention is to overcome at least a part of the above stated problems. The above object, together with numerous other objects, which will become evident from the detailed description below, is obtained according to a first aspect of the present invention by a communication device comprising a keymat, a cover, and a substrate comprising a plurality of key switches, wherein the keymat is exteriorly attachable on the cover, and keypins of said keymat extend through holes of said cover towards said plurality of key switches, wherein the keymat comprises a plurality of lips located at the edges of the keymat, and the cover comprises a plurality of indentations configured to receive the plurality of lips, wherein the indentations are located at the edges of a recess for removably mounting the keymat. The keymat may comprise one or more guiding pieces, and the cover may comprise one or more corresponding guiding recesses. The guiding pieces may be arranged in direct connection to one or more of the plurality of lips. The keymat may be provided with one or more guiding recesses, and the cover may be provided with one or more corresponding guide pieces. The guiding pieces may be one or more ribs extending to be received by the guide pieces. The above object, together with numerous other objects, which will become evident from the detailed description below, is obtained according to a second aspect of the present invention by a cover for a communication device comprising a recess for receiving a keymat comprising a plurality of lips, wherein the recess is provided with a plurality of indentations located at the edges of the recess for receiving the plurality of lips. The cover may further comprise one or more guiding recesses. The one or more guiding recesses may be arranged in direct connection to one or more of said plurality of indentations. The cover may further comprise one or more guiding pieces. The guiding pieces may be one or more ribs on a surface of the cover facing a place where a keymat is to be mounted. The above object, together with numerous other objects, which will become evident from the detailed description below, is obtained according to a third aspect of the present invention by a keymat for removable mounting on a cover of a communication device, comprising lips located at the edges of the keymat. The lips are configured to insert into indentations of said cover. The keymat may further comprise one or more guiding pieces. The guiding pieces may be arranged in direct connection to one or more of said plurality of lips. The keymat may further comprise one or more guiding recesses. Said one or more guiding recesses may be an incision in a surface that is to be in contact with a cover when mounted on the cover. The keymat may be moulded in one piece. A particular feature of the present invention relates to the possibility to mount, demount, and remount the keymat without any tools or training. A particular advantage of the present invention is easier mounting, demounting, and remounting of a keymat since the cover do not have to be removed. Further, an advantage of the invention is that the retaining of the keymat is improved, and the risk for unintentional removal of the keymat during wearing and using the communication device is decreased. Another advantage of the present invention is that a designer has more freedom in designing different keymats, and the user has more freedom in changing keymats. Another advantage of the present invention is a more attractive appearance, since the recess of the cover enables the keymat to be in level of the cover. Another advantage of the present invention is reduced costs since the exchangeable keymat can be moulded in one piece, and material can be saved. | 20040227 | 20101130 | 20050901 | 85599.0 | 0 | STEPHEN, EMEM O | EXCHANGEABLE KEYMAT | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,788,575 | ACCEPTED | Methods and apparatuses of estimating the position of a mobile user in a system of satellite differential navigation | Disclosed are methods and apparatuses for estimating the floating ambiguities associated with the measurement of the carrier signals of a plurality of global positioning satellites, such that the floating ambiguities are preferably consist for a plurality of different time moments. In one aspect of the invention, a real-time iterative matrix refactorization process is provided which reduces processor load and retains history of the measurements. | 1. A method of estimating a set of floating ambiguities associated with a set of phase measurements of a plurality n of satellite carrier signals made by a first navigation receiver (B) and a second navigation receiver (R) separated by a distance, wherein a baseline vector (xo,yo,zo) relates the position of the second receiver to the first receiver, each satellite carrier signal being transmitted by a satellite and having a wavelength, wherein each receiver has a time clock for referencing its measurements and wherein any difference between the time clocks may be represented by an offset, said method receiving, for a plurality of two or more time moments j, the following inputs: a vector γjB representative of a plurality of pseudo-ranges measured by the first navigation receiver (B) and corresponding to the plurality of satellite carrier signals, a vector γjR representative of a plurality of pseudo-ranges measured by the second navigation receiver (R) and corresponding to the plurality of satellite carrier signals, a vector DjB representative of a plurality of estimated distances between the satellites and the first navigation receiver (B), a vector DjR representative of a plurality of estimated distances between the satellites and the second navigation receiver (R), a vector φjB representative of a plurality of full phase measurements of the satellite carrier signals measured by the first navigation receiver (B), a vector φjR representative of a plurality of full phase measurements of the satellite carrier signals measured by the second navigation receiver (R), a geometric Jacobian matrix Hjγ whose matrix elements are representative of the changes in the distances between the satellites and one of the receivers that would be caused by changes in that receiver's position and time clock offset, said method comprising the steps of: (a) generating, for each time moment j, a vector Δγj of a plurality of range residuals of pseudo-range measurements made by the first and second navigation receivers in the form of: Δγj=(γjR−γjB)−(DjR−DjB); (b) generating, for each time moment j, a vector Δφj of a plurality of phase residuals of full phase measurements made by the first and second navigation receivers in the form of: Δφj=(φjR−φjB)−Λ−1·(DjR−DjB), where Λ−1 is a diagonal matrix comprising the inverse wavelengths of the satellites; (c) generating, for time moment j=1, an LU-factorization of a matrix M1 or a matrix inverse of matrix M1, the matrix M1 being a function of at least Λ−1 and H1γ, (d) generating, for time moment j=1, a vector N1 as a function of at least Δγ1, Δφ1, and the LU-factorization of matrix M1 or the matrix inverse of matrix M1; (e) generating, for an additional time moment j≠1, an LU-factorization of a matrix Mj or a matrix inverse of matrix Mj, the matrix Mj being a function of at least Λ−1, Hjγ and an instance of matrix M generated for a different time moment; and (f) generating, for an additional time moment j≠1, a vector Nj as a function of at least Δγj, Δφj, and the LU-factorization or matrix Mj or the matrix inverse of matrix Mj, the vector Nj having estimates of the floating ambiguities. 2. The method of claim 1 wherein step (c) comprises generating an LU-factorization for a matrix comprising a form equivalent to (GTP1G), where: the matrix G has 2n rows, n columns, an upper sub-matrix, and a lower sub-matrix, one of the sub-matrices comprises an n×n zero matrix and the other sub-matrix comprising an n×n identity matrix, the matrix GT comprises the transpose matrix of matrix G, and the matrix P1 has 2n rows, 2n columns, and a form which comprises a matrix equivalent to (R1−1−R1−1Q1(Q1TR1−1Q1+qS1)−1Q1TR1−1) where the matrix R1 is a weighting matrix, where the matrix R1−1 comprises an inverse of matrix R1, where the matrix Q1 has an upper sub-matrix and a lower sub-matrix, one of the sub-matrices of Q1 comprising matrix H1γ and the other of the sub-matrices of Q1 comprising the matrix product Λ−1H1γ, and wherein the matrix Q1T comprises the transpose of matrix Q1, and where the quantity qSk is a zero matrix when the distance between the first and second navigation receivers is unconstrained and where q may be a non-zero weighting parameter and Sk may be a non-zero matrix when the distance between the first and second navigation receivers is constrained. 3. The method of claim 2 wherein step (d) comprises the step of generating vector N1 to comprise a vector having a form equivalent to M1−1(GTP1μ1+qg1), where the matrix M1−1 comprises an inverse of matrix of matrix M1, and where the vector μ1 comprises the vector [Δγ1, Δφ1]T, and where the quantity qgk is a zero vector when the distance between the first and second navigation receivers is unconstrained and where q may be non-zero and gk may be a non-zero vector when the distance between the first and second navigation receivers is constrained. 4. The method of claim 1 wherein step (e) comprises generating an LU-factorization for a matrix comprising a form equivalent to Mj=Mj−1+GTPjG, where: Mj−1 comprises the matrix M1 of step (c) when j=2 and comprises the matrix Mj of step (e) for the j−1 time moment when j>2, the matrix G has 2n rows, n columns, an upper sub-matrix, and a lower sub-matrix, one of the sub-matrices comprising an n×n zero matrix and the other sub-matrix comprising an n×n identity matrix, the matrix GT comprises the transpose matrix of matrix G, and the matrix Pj has 2n rows, 2n columns, and a form which comprise a matrix equivalent to (Rj−1−Rj−1Qj(QjTRj−1Qj+qSj)−1QjTRj−1) where the matrix Rj is a weighting matrix, where the matrix Rj−1 comprises an inverse of matrix Rj, where the matrix Qj has an upper sub-matrix and a lower sub-matrix, one of the sub-matrices of Qj comprising matrix Hjγ and the other of the sub-matrices of Qj comprising the matrix product Λ−1Hjγ, and wherein the matrix QjT comprises the transpose of matrix Qj, and where the quantity qSj is a zero matrix when the distance between the first and second navigation receivers is unconstrained and where q may be a non-zero weighting parameter and Sj may be a non-zero matrix when the distance between the first and second navigation receivers is constrained. 5. The method of claim 4 wherein step (f) comprises the step of generating vector Nj to comprise a vector having a form equivalent to Nj−1+Mj−1└GTPj(μj−GNj−1)+qgj┘, where the matrix Mj−1 comprises an inverse of matrix of matrix Mj, where the vector μj comprises the vector [Δγj, Δφj]T, and where the vector Nj−1 comprises the vector N1 generated by step (d) when j=2 and comprises the vector Nj−1 generated by step (f) for the j−1 time moment when j>2, and where the quantity qgj is a zero vector when the distance between the first and second navigation receivers is unconstrained and where q may be non-zero and gj may be a non-zero vector when the distance between the first and second navigation receivers is constrained. 6. The method of claim 3 wherein the distance between the first and second navigation receivers is constrained to a distance LRB, wherein step (c) generates matrix S1 in a form equivalent to: S 1 = ( 1 - L RB r 1 ) ( I 3 O 3 × 1 O 1 × 3 0 ) + L RB r 1 r 1 r 1 T where r1 is a vector comprising estimates of the three coordinates of the baseline vector for the time moment j=1 and a zero as fourth component, where r1T is the vector transpose of r1, where I3 is the 3-by-3 identity matrix, where O1×3 is a row vector of three zeros, and where O3×1 is a column vector of three zeros; and wherein step (d) generates vector g1 for the time moment j=1 in a form equivalent to: g1=GTR1−1Q1(Q1TR1−1Q1+qS1)−1h1, where: h 1 = ( 1 - L RB r 1 ) r 1 . 7. The method of claim 3 wherein weighting matrix R1 comprises an identity matrix multiplied by a scalar quantity. 8. The method of claim 5 wherein the distance between the first and second navigation receivers is constrained to a distance LRB, wherein step (e) generates matrix Sj in a form equivalent to: Sj = ( 1 - L RB r j ) ( I 3 O 3 × 1 O 1 × 3 0 ) + L RB r j rj rj T where rj is a vector comprising estimates of the three coordinates of the baseline vector for the j-th time moment and a zero as fourth vector component, where rjT is the vector transpose of rj, where I3 is the 3-by-3 identity matrix, where O1×3 is a row vector of three zeros, and where O3×1 is a column vector of three zeros; and wherein step (f) generates vector gj for the j-th time moment in a form equivalent to: gj=GTRj−1Qj(QjTRj−1Qj+qSj)−1hj, where: h j = ( 1 - L RB r j ) r j . 9. The method of claim 5 wherein the weighting matrix Rj comprises an identity matrix multiplied by a scalar quantity for at least one time moment j. 10. The method of claim 4 wherein the generation of the LU-factorization in step (e) comprises the steps of: (g) generating an LU-factorization of matrix Mj−1 in a form equivalent to Lj−1Lj−1T wherein Lj−1 is a low-triangular matrix and Lj−1T is the transpose of Lj−1; (h) generating a factorization of GTPjG in a form equivalent to TjTjT=GTPjG, where TjT is the transpose of Tj; (i) generating an LU-factorization of matrix Mj in a form equivalent to LjLjT from a plurality n of rank-one modifications of matrix Lj−1, each rank-one modification being based on a respective column of matrix Tj, where n is the number of rows in matrix Mj. 11. The method of claim 10 wherein step (h) generates matrix Tj from a Cholesky factorization of GTPjG. 12. The method of claim 10 wherein weighting matrix Rj has a form equivalent to: R j = [ R j γ 0 0 R j φ ] , where Rγ and Rφ are weighting matrices; wherein Rγ and Rφ are related to a common weighting matrix W and scaling parameters σγ and σφ as follows ( R γ ) - 1 = 1 σ γ 2 W , and ( R φ ) - 1 = 1 σ φ 2 W , wherein step (h) of generating matrix Tj comprises the steps of: generating a scalar b in a form equivalent to: b = σ γ 2 λ GPS 2 σ γ 2 + λ GPS 2 σ ψ 2 , where λGPS is the wavelength of the satellite signals, generating a matrix {tilde over (H)} in a form equivalent to {tilde over (H)}=W1/2Hjγ, generating a Householder matrix SHH for matrix {tilde over (H)}, and generating matrix Tj in a form equivalent to: T j = 1 σ ψ W 1 / 2 S HH [ ( 1 - b λ GPS 2 ) I 4 | O 4 × ( n - 4 ) — — — | — — — O ( n - 4 ) × 4 | I ( n - 4 ) × ( n - 4 ) ] . 13. The method of claim 10 wherein weighting matrix Rj is applied to a case where there is a first group of satellite signals having carrier signals in a first wavelength band and a second group of satellite signals having a carrier signals in a second wavelength band, the weighting frequency having a form equivalent to: R j = [ R j γ 0 0 R j ψ ] , where Rγ and Rφ are weighting matrices; wherein Rγ and Rφ are related to a common weighting matrix W, the carrier wavelengths of the first group of signals as represented by matrix Λ(1), the carrier wavelengths of the second group of signals as represented by matrix Λ(2), the center wavelength of the first band as represented by λ1, the center wavelength of the first band as represented by λ2, and scaling parameters σγ and σφ, as follows: ( R j γ ) - 1 = [ 1 σ γ 2 W | O n × n — — — | — — — O n × n | 1 σ γ 2 W ] , ( R j ψ ) - 1 = [ 1 σ ψ 2 W ( 1 ) | O n × n — — — | — — — O n × n | 1 σ γ 2 W ( 2 ) ] , where W ( 1 ) = 1 λ 1 2 Λ ( 1 ) W Λ ( 1 ) , W ( 2 ) = 1 λ 2 2 Λ ( 2 ) W Λ ( 2 ) , wherein step (h) of generating matrix Tj comprises the steps of: generating a scalar b in a form equivalent to: b = σ γ 2 λ 1 2 λ 2 2 2 σ ψ 2 λ 1 2 λ 2 2 + σ γ 2 λ 1 2 + σ γ 2 λ 2 2 , where λ1 is the wavelength of a first group of satellite signals and λ2 is the wavelength of a second group of satellite signals, generating a matrix {tilde over (H)} in a form equivalent to {tilde over (H)}=W1/2Hjγ, generating a Householder matrix SHH for matrix {tilde over (H)}, and generating matrix Tj in a form equivalent to: T j = 1 σ φ [ A11 O n × n A21 A22 ] , where sub-matrixces A11, A21, and A22 are as follows: A 11 = ( W ( 1 ) ) 1 2 S HH [ 1 - b / λ 1 2 I 4 | O 4 × ( n - 4 ) -- -- -- | -- -- -- O ( n - 4 ) × 4 | I ( n - 4 ) ] , A 21 = ( W ( 2 ) ) 1 2 S HH [ - b λ 1 λ 2 1 - b / λ 1 2 I 4 | O 4 × ( n - 4 ) -- -- -- | -- -- -- O ( n - 4 ) × 4 | O ( n - 4 ) × ( n - 4 ) ] , and A 22 = ( W ( 2 ) ) 1 2 S HH [ 1 - b / λ 1 2 - b / λ 2 2 1 - b / λ 1 2 I 4 | O 4 × ( n - 4 ) -- -- -- | -- -- -- O ( n - 4 ) × 4 | I ( n - 4 ) ] . 14. The method of claim 4 wherein step (d) comprises generating a vector B1 to comprise a vector having a form equivalent to GTP1μ1+qg1, where the vector μ1 comprises the vector [Δγ1, Δφ1]T, and where the quantity qgj is a zero vector when the distance between the first and second navigation receivers is unconstrained and where q may be non-zero and gj may be a non-zero vector when the distance between the first and second navigation receivers is constrained; and wherein step (f) further comprises generating, for each time moment j≠1, a vector Bj to comprise a matrix having a form equivalent to Bj−1+GTPjμj+qgi, where the vector μj comprises the vector [Δγj, Δφj]T, and where the vector Bj−1 is the vector B1 generated by step (d) when j=2 and comprises the vector generated by step (f) for the for the j−1 time moment when j>2, and where the quantity qgi is a zero vector when the distance between the first and second navigation receivers is unconstrained and where q may be non-zero and gj may be a non-zero vector when the distance between the first and second navigation receivers is constrained; and wherein step (f) further comprises generating vector Nj to comprise a vector having a form equivalent to Nj=[Mj]−1Bj, where the matrix Mj−1 comprises an inverse of matrix of matrix Mj. 15. The method of claim 14 wherein the distance between the first and second navigation receivers is constrained to a distance LRB, wherein step (c) generates matrix S1 in a form equivalent to: S 1 = ( 1 - L RB ∥ r 1 ∥ ) ( I 3 O 3 × 1 O 1 × 3 0 ) + L RB ∥ r 1 ∥ r 1 r 1 T where r1 is a vector comprising estimates of the three coordinates of the baseline vector for the time moment j=1 and a zero as fourth component, where r1T is the vector transpose of r1, where I3 is the 3-by-3 identity matrix, where O1×3 is a row vector of three zeros, and where O3×1 is a column vector of three zeros; and wherein step (d) generates vector g1 for the time moment j=1 in a form equivalent to: g1=GRR1−1Q1(Q1TR1−1Q1+qS1)−1h1, where: h 1 = ( 1 - L RB ∥ r 1 ∥ ) r 1 . 16. The method of claim 14 wherein the distance between the first and second navigation receivers is constrained to a distance LRB, wherein step (e) generates matrix Sj in a form equivalent to: Sj = ( 1 - L RB ∥ r j ∥ ) ( I 3 O 3 × 1 O 1 × 3 0 ) + L RB ∥ r j ∥ r j r j T where rj is a vector comprising estimates of the three coordinates of the baseline vector for the j-th time moment and a zero as fourth vector component, where rjT is the vector transpose of rj, where I3 is the 3-by-3 identity matrix, where O1×3 is a row vector of three zeros, and where O3×1 is a column vector of three zeros; and wherein step (f) generates vector gj for the j-th time moment in a form equivalent to: gj=GTRj−1Qj(QjTRj−1Qj+qSj)−1hj, where: h j = ( 1 - L RB r j ) r j . 17. The method of claim 14 wherein the weighting matrix Rj comprises an identity matrix multiplied by a scalar quantity for at least one time moment j. 18. A method of estimating a set of floating ambiguities associated with a set of phase measurements of a plurality n of satellite carrier signals made by a first navigation receiver (B) and a second navigation receiver (R), wherein a baseline vector (xo,yo,zo) relates the position of the second receiver to the first receiver, each satellite carrier signal being transmitted by a satellite and having a wavelength, wherein each receiver has a time clock for referencing its measurements and wherein any difference between the time clocks may be represented by an offset, said method receiving, for a plurality of two or more time moments j, the following inputs for each time moment j: a vector γjB representative of a plurality of pseudo-ranges measured by the first navigation receiver (B) and corresponding to the plurality of satellite carrier signals, a vector γjR representative of a plurality of pseudo-ranges measured by the second navigation receiver (R) and corresponding to the plurality of satellite carrier signals, a vector DjB representative of a plurality of estimated distances between the satellites and the first navigation receiver (B), a vector DjR representative of a plurality of estimated distances between the satellites and the second navigation receiver (R), a vector φjB representative of a plurality of full phase measurements of the satellite carrier signals measured by the first navigation receiver (B), a vector φjR representative of a plurality of full phase measurements of the satellite carrier signals measured by the second navigation receiver (R), a geometric Jacobian matrix Hjγ whose matrix elements are representative of the changes in the distances between the satellites and one of the receivers that would be caused by changes in that receiver's position and time clock offset, said method comprising the steps of: (a) generating, for each time moment j, a vector Δγj of a plurality of range residuals of pseudo-range measurements made by the first and second navigation receivers in the form of: Δγj=(γjR−γjB)−(DjR−DjB), said step generating a set of range residuals Δγk, k=1, . . . , j; (b) generating, for each time moment j, a vector Δφj of a plurality of phase residuals of full phase measurements made by the first and second navigation receivers in the form of: Δφj=(φjR−φjB)−Λ−1·(DjR−DjB), where Λ−1 is a diagonal matrix comprising the inverse wavelengths of the satellites, said step generating a set of phase residuals Δφk, k=1, . . . , j; (c) generating an LU-factorization of a matrix M or a matrix inverse of matrix M, the matrix M being a function of at least Λ−1 and Hkγ, for index k of Hkγ covering at least two of the time moments j; (d) generating a vector N of estimated floating ambiguities as a function of at least the set of range residuals Δγk, the set of phase residuals Δφk, and the LU-factorization of matrix M or the matrix inverse of matrix M. 19. The method of claim 18 wherein step (c) comprises generating matrix M in a form equivalent to the summation [ ∑ k = 1 j ( G T P k G ) ] , where: the matrix G has 2n rows, n columns, an upper sub-matrix, and a lower sub-matrix, one of the sub-matrices comprises an n×n zero matrix and the other sub-matrix comprising an n×n identity matrix, the matrix GT comprises the transpose matrix of matrix G, and the matrix Pk has 2n rows, 2n columns, and a form which comprises a matrix equivalent to Pk=Rk−1−Rk−1Qk(QkTRk−1Qk+qSk)−1QkTRk−1, where the matrix Rk is a weighting matrix, where the matrix Rk−1 comprises an inverse of matrix Rk, where the matrix Qk has an upper sub-matrix and a lower sub-matrix, one of the sub-matrices of Qk comprising matrix Hkγ and the other of the sub-matrices of Qk comprising the matrix product Λ−1Hkγ, and wherein the matrix QkT comprises the transpose of matrix Qk, and where the quantity qSk is a zero matrix when the distance between the first and second navigation receivers is unconstrained and where q may be a non-zero weighting parameter and Sk may be a non-zero matrix when the distance between the first and second navigation receivers is constrained. 20. The method of claim 19 wherein step (d) comprises generating matrix N in a form equivalent to: N = M - 1 × [ ∑ k = 1 j ( G T P k μ k + qg k ) ] , where the matrix M−1 comprises an inverse of matrix of matrix M, where the vector μk comprises the vector [Δγk, Δφk]T, and where the quantity qgk is a zero vector when the distance between the first and second navigation receivers is unconstrained and where q may be non-zero and gk may be a non-zero vector when the distance between the first and second navigation receivers is constrained. 21. The method of claim 20 wherein the distance between the first and second navigation receivers is constrained to a distance LRB, wherein step (c) generates matrix Sk for the k-th time moment in a form equivalent to: S k = ( 1 - L RB r k ) ( I 3 O 3 × 1 O 1 × 3 0 ) + L RB r k r k r k T where rk is a vector comprising estimates of the three coordinates of the baseline vector at the k-th time moment, and a zero as fourth component, where rkT is the vector transpose of rk, where I3 is the 3-by-3 identity matrix, where O1×3 is a row vector of three zeros, and where O3×1 is a column vector of three zeros; and wherein step (d) generates vector gk for the k-th time moment in a form equivalent to: gk=GTRk−1Qk(QkTRk−1Qk+qsk)−1hk, where: h k = ( 1 - L RB r k ) r k . 22. The method of claim 19 wherein at least one of the weighting matrices Rk comprises an identity matrix multiplied by a scalar quantity. 23. A computer program product for directing a data processor to estimate a set of floating ambiguities associated with a set of phase measurements of a plurality n of satellite carrier signals made by a first navigation receiver (B) and a second navigation receiver (R) separated by a distance, wherein a baseline vector (xo,yo,zo) relates the position of the second receiver to the first receiver, each satellite carrier signal being transmitted by a satellite and having a wavelength, wherein each receiver has a time clock for referencing its measurements and wherein any difference between the time clocks may be represented by an offset, the process receiving, for a plurality of two or more time moments j, the following inputs: a vector γjB representative of a plurality of pseudo-ranges measured by the first navigation receiver (B) and corresponding to the plurality of satellite carrier signals, a vector γjR representative of a plurality of pseudo-ranges measured by the second navigation receiver (R) and corresponding to the plurality of satellite carrier signals, a vector DjB representative of a plurality of estimated distances between the satellites and the first navigation receiver (B), a vector DjR representative of a plurality of estimated distances between the satellites and the second navigation receiver (R), a vector φjB representative of a plurality of full phase measurements of the satellite carrier signals measured by the first navigation receiver (B), a vector φjR representative of a plurality of full phase measurements of the satellite carrier signals measured by the second navigation receiver (R), a geometric Jacobian matrix Hjγ whose matrix elements are representative of the changes in the distances between the satellites and one of the receivers that would be caused by changes in that receiver's position and time clock offset, the computer program product comprising: a computer-readable medium; a first set of instructions embodied on the computer-readable medium which directs the data processor to generate, for each time moment j, a vector Δγj of a plurality of range residuals of pseudo-range measurements made by the first and second navigation receivers in the form of: Δγj=(γjR−γjB)−(DjR−DjB); a second set of instructions embodied on the computer-readable medium which directs the data processor to generate, for each time moment j, a vector Δφj of a plurality of phase residuals of full phase measurements made by the first and second navigation receivers in the form of: Δφj=(φjR−φjB)−Λ−1·(DjR−DjB), where Λ−1 is a diagonal matrix comprising the inverse wavelengths of the satellites; a third set of instructions embodied on the computer-readable medium which directs the data processor to generate, for time moment j=1, an LU-factorization of a matrix M1 or a matrix inverse of matrix M1, the matrix Ml being a function of at least Λ−1 and H1γ; a fourth set of instructions embodied on the computer-readable medium which directs the data processor to generate, for time moment j=1, a vector N1 as a function of at least Δγ1, Δφ1, and the LU-factorization of matrix M1 or the matrix inverse of matrix M1; a fifth set of instructions embodied on the computer-readable medium which directs the data processor to generate, for an additional time moment j≠1, an LU-factorization of a matrix Mj or a matrix inverse of matrix Mj, the matrix Mj being a function of at least Λ−1 and Hjγ; and a sixth set of instructions embodied on the computer-readable medium which directs the data processor to generate, for an additional time moment j≠1, a vector Nj as a function of at least Δγj, Δφj, and the LU-factorization or matrix Mj or the matrix inverse of matrix Mj, the vector Nj having estimates of the floating ambiguities. 24. The computer program product of claim 23 wherein the third set of instructions directs the data processor to generate an LU-factorization for a matrix comprising a form equivalent to (GTP1G), where: the matrix G has 2n rows, n columns, an upper sub-matrix, and a lower sub-matrix, one of the sub-matrices comprises an n×n zero matrix and the other sub-matrix comprising an n×n identity matrix, the matrix GT comprises the transpose matrix of matrix G, and the matrix P1 has 2n rows, 2n columns, and a form which comprises a matrix equivalent to (R1−1−R1−1Q1(Q1TR1−1Q1+qS1)−1Q1TR1−1) where the matrix R1 is a weighting matrix, where the matrix R1−1 comprises an inverse of matrix R1, where the matrix Q1 has an upper sub-matrix and a lower sub-matrix, one of the sub-matrices of Q1 comprising matrix H1γ and the other of the sub-matrices of Q1 comprising the matrix product Λ−1H1γ, and wherein the matrix Q1T comprises the transpose of matrix Q1, and where the quantity qSk is a zero matrix when the distance between the first and second navigation receivers is unconstrained and where q may be a non-zero weighting parameter and Sk may be a non-zero matrix when the distance between the first and second navigation receivers is constrained. 25. The computer program product of claim 24 wherein the fourth set of instructions directs the data processor to generate vector N1 to comprise a vector having a form equivalent to M1−1(GTP1μ1+qg1), where the matrix M11 comprises an inverse of matrix of matrix M1, and where the vector μ1 comprises the vector [Δγ1, Δφ1]T, and where the quantity qgk is a zero vector when the distance between the first and second navigation receivers is unconstrained and where q may be non-zero and gk may be a non-zero vector when the distance between the first and second navigation receivers is constrained. 26. The computer program product of claim 23 wherein the fifth set of instructions directs the data processor to generate an LU-factorization for a matrix comprising a form equivalent to Mj=Mj−1+GTPjG, where: Mj−1 comprises the matrix M1 of step (c) when j=2 and comprises the matrix Mj of step (e) for the j−1 time moment when j>2, the matrix G has 2n rows, n columns, an upper sub-matrix, and a lower sub-matrix, one of the sub-matrices comprising an n×n zero matrix and the other sub-matrix comprising an n×n identity matrix, the matrix GT comprises the transpose matrix of matrix G, and the matrix Pj has 2n rows, 2n columns, and a form which comprise a matrix equivalent to (Rj−1−Rj−1Qj(QjTRj−1Qj+qSj)−1QjTRj−1) where the matrix Rj is a weighting matrix, where the matrix Rj−1 comprises an inverse of matrix Rj, where the matrix Qj has an upper sub-matrix and a lower sub-matrix, one of the sub-matrices of Qj comprising matrix Hjγ and the other of the sub-matrices of Qj comprising the matrix product Λ−1Hjγ, and wherein the matrix QjT comprises the transpose of matrix Qj, and where the quantity qSj is a zero matrix when the distance between the first and second navigation receivers is unconstrained and where q may be a non-zero weighting parameter and Sj may be a non-zero matrix when the distance between the first and second navigation receivers is constrained. 27. The computer program product of claim 26 wherein the sixth set of instructions directs the data processor to generate a vector Nj to comprise a vector having a form equivalent to Nj−1+Mj−1└GTPj(μj−GNj−1)+qgj┘, where the matrix Mj−1 comprises an inverse of matrix of matrix Mj, where the vector μj comprises the vector [Δγj, Δφj]T, and where the vector Nj−1 comprises the vector N1 generated by step (d) when j=2 and comprises the vector Nj−1 generated by step (f) for the j−1 time moment when j>2, and where the quantity qgj is a zero vector when the distance between the first and second navigation receivers is unconstrained and where q may be non-zero and gj may be a non-zero vector when the distance between the first and second navigation receivers is constrained. 28. The computer program product of claim 27 wherein the distance between the first and second navigation receivers is constrained to a distance LRB, and wherein the fifth set of instructions directs the data processor to generate matrix Sj in a form equivalent to: S j = ( 1 - L RB r j ) ( I 3 O 3 × 1 O 1 × 3 0 ) + L RB r j r j r j T where rj is a vector comprising estimates of the three coordinates of the baseline vector for the j-th time moment and a zero as fourth vector component, where rjT is the vector transpose of rj, where I3 is the 3-by-3 identity matrix, where O1×3 is a row vector of three zeros, and where O3×1 is a column vector of three zeros; and wherein the sixth set of instructions directs the data processor to generate vector gj for the j-th time moment in a form equivalent to: gj=GTRj−1Qj(QjTRj−1Qj+qsj)−1hj, where: h j = ( 1 - L RB r j ) r j . 29. The computer program product of claim 28 wherein the fifth set of instructions comprises: a seventh set of instructions that direct the data processor to generate an LU-factorization of matrix Mj−1 in a form equivalent to Lj−1 Lj−1T wherein Lj−1 is a low-triangular matrix and Lj−1T is the transpose of Lj−1; an eighth set of instructions that direct the data processor to generate a factorization of GT Pj G in a form equivalent to TjTjT=GT=GTPjG, where TjT is the transpose of Tj; and a ninth set of instructions that direct the data processor to generate an LU-factorization of matrix Mj in a form equivalent to Lj LjT from a plurality n of rank-one modifications of matrix Lj−1, each rank-one modification being based on a respective column of matrix Tj, where n is the number of rows in matrix Mj. 30. The computer program product of claim 29 wherein the eighth set of instructions directs the data processor to generate matrix Tj from a Cholesky factorization of GT Pj G. 31. The computer program product of claim 29 wherein weighting matrix Rj has a form equivalent to: R j = [ R j γ 0 0 R j φ ] , where Rγ and Rφ are weighting matrices; wherein Rγ and Rφ are related to a common weighting matrix W and scaling parameters σγ and σφ as follows ( R γ ) - 1 = 1 σ γ 2 W , and ( R φ ) - 1 = 1 σ φ 2 W ; and wherein the eighth set of instructions comprises: instructions that direct the data processor to generate a scalar b in a form equivalent to: b = σ γ 2 λ GPS 2 σ γ 2 + λ GPS 2 σ φ 2 , where λGPS2 is the wavelength of the satellite signals, instructions that direct the data processor to generate a matrix {tilde over (H)} in a form equivalent to {tilde over (H)}=W1/2Hjγ, instructions that direct the data processor to generate a Householder matrix SHH for matrix {tilde over (H)}, and instructions that direct the data processor to generate matrix Tj in a form equivalent to: T j = 1 σ φ W 1 / 2 S HH [ ( 1 - b λ GPS 2 ) I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 I ( n - 4 ) × ( n - 4 ) ] . 32. The method of claim 29 wherein weighting matrix Rj is applied to a case where there is a first group of satellite signals having carrier signals in a first wavelength band and a second group of satellite signals having a carrier signals in a second wavelength band, the weighting frequency having a form equivalent to: R j = [ R j γ 0 0 R j φ ] , where Rγ and Rφ are weighting matrices; wherein Rγ and Rφ are related to a common weighting matrix W, the carrier wavelengths of the first group of signals as represented by matrix Λ(1), the carrier wavelengths of the second group of signals as represented by matrix Λ(2), the center wavelength of the first band as represented by λ1, the center wavelength of the first band as represented by λ2, and scaling parameters σγ and σφ, as follows: ( R j γ ) - 1 = [ 1 σ γ 2 W O n × n O n × n 1 σ γ 2 W ] , ( R j φ ) - 1 = [ 1 σ φ 2 W ( 1 ) O n × n O n × n 1 σ φ 2 W ( 2 ) ] , where W ( 1 ) = 1 λ 1 2 Λ ( 1 ) W Λ ( 1 ) , W ( 2 ) = 1 λ 2 2 Λ ( 2 ) W Λ ( 2 ) , wherein step (h) of generating matrix Tj comprises the steps of: generating a scalar b in a form equivalent to: b = σ γ 2 λ 1 2 λ 2 2 2 σ φ 2 λ 1 2 λ 2 2 + σ γ 2 λ 1 2 + σ γ 2 λ 2 2 , where λ1 is the wavelength of a first group of satellite signals and λ2 is the wavelength of a second group of satellite signals, generating a matrix {tilde over (H)} in a form equivalent to {tilde over (H)}=W1/2Hjγ, generating a Householder matrix SHH for matrix {tilde over (H)}, and generating matrix Tj in a form equivalent to: T j = 1 σ φ [ A11 O n × n A21 A22 ] , where sub-matrixces A11, A21, and A22 are as follows: A11 = ( W ( 1 ) ) 1 2 S HH [ 1 - b / λ 1 2 I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 I ( n - 4 ) ] , A21 = ( W ( 2 ) ) 1 2 S HH [ - b λ 1 λ 2 1 - b / λ 1 2 I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 O ( n - 4 ) × ( n - 4 ) ] , and A22 = ( W ( 2 ) ) 1 2 S HH [ 1 - b / λ 1 2 - b / λ 2 2 1 - b / λ 1 2 I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 I ( n - 4 ) ] . 33. A computer program product for directing a data processor to estimate a set of floating ambiguities associated with a set of phase measurements of a plurality n of satellite carrier signals made by a first navigation receiver (B) and a second navigation receiver (R) separated by a distance, wherein a baseline vector (xo,yo,zo) relates the position of the second receiver to the first receiver, each satellite carrier signal being transmitted by a satellite and having a wavelength, wherein each receiver has a time clock for referencing its measurements and wherein any difference between the time clocks may be represented by an offset, the process receiving, for a plurality of two or more time moments j, the following inputs: a vector γjB representative of a plurality of pseudo-ranges measured by the first navigation receiver (B) and corresponding to the plurality of satellite carrier signals, a vector γjR representative of a plurality of pseudo-ranges measured by the second navigation receiver (R) and corresponding to the plurality of satellite carrier signals, a vector DjB representative of a plurality of estimated distances between the satellites and the first navigation receiver (B), a vector DjR representative of a plurality of estimated distances between the satellites and the second navigation receiver (R), a vector φjB representative of a plurality of full phase measurements of the satellite carrier signals measured by the first navigation receiver (B), a vector φjB representative of a plurality of full phase measurements of the satellite carrier signals measured by the second navigation receiver (R), a geometric Jacobian matrix Hjγ whose matrix elements are representative of the changes in the distances between the satellites and one of the receivers that would be caused by changes in that receiver's position and time clock offset, the computer program product comprising: a computer-readable medium; a first set of instructions embodied on the computer-readable medium which directs the data processor to generate, for each time moment j, a vector Δγj of a plurality of range residuals of pseudo-range measurements made by the first and second navigation receivers in the form of: Δγj=(γjR−γjB)−(DjR−DjB); a second set of instructions embodied on the computer-readable medium which directs the data processor to generate, for each time moment j, a vector Δφj of a plurality of phase residuals of full phase measurements made by the first and second navigation receivers in the form of: Δφj=(φjR−φjB)−Λ−1·(DjR−DjB), where Λ−1 is a diagonal matrix comprising the inverse wavelengths of the satellites; a third set of instructions embodied on the computer-readable medium which directs the data processor to generate an LU-factorization of a matrix M or a matrix inverse of matrix M, the matrix M being a function of at least Λ−1 and Hkγ, for index k of Hkγ covering at least two of the time moments j; and a fourth set of instructions embodied on the computer-readable medium which directs the data processor to generate a vector N of estimated floating ambiguities as a function of at least the set of range residuals Δγk, the set of phase residuals Δφk, and the LU-factorization of matrix M or the matrix inverse of matrix M. 34. The computer program product of claim 33 wherein the third set of instructions directs the data processor to generate matrix M in a form equivalent to the summation [ ∑ k = 1 j ( G T P k G ) ] , where: the matrix G has 2n rows, n columns, an upper sub-matrix, and a lower sub-matrix, one of the sub-matrices comprises an n×n zero matrix and the other sub-matrix comprising an n×n identity matrix, the matrix GT comprises the transpose matrix of matrix G, and the matrix Pk has 2n rows, 2n columns, and a form which comprises a matrix equivalent to Pk=Rk−1−Rk−1Qk(QkTRk−1Qk+qSk)−1QkTRk−1, where the matrix Rk is a weighting matrix, where the matrix Rk−1 comprises an inverse of matrix Rk, where the matrix Qk has an upper sub-matrix and a lower sub-matrix, one of the sub-matrices of Qk comprising matrix Hkγ and the other of the sub-matrices of Qk comprising the matrix product Λ−1Hkγ, and wherein the matrix QkT comprises the transpose of matrix Qk, and where the quantity qSk is a zero matrix when the distance between the first and second navigation receivers is unconstrained and where q may be a non-zero weighting parameter and Sk may be a non-zero matrix when the distance between the first and second navigation receivers is constrained. 35. The computer program product of claim 34 wherein the fourth set of instructions directs the data processor to generate matrix N in a form equivalent to: N = M - 1 × [ ∑ k = 1 j ( G T P k μ k + qg k ) ] , where the matrix M−1 comprises an inverse of matrix of matrix M, where the vector μk comprises the vector [Δγk, Δφk]T, and where the quantity qgk is a zero vector when the distance between the first and second navigation receivers is unconstrained and where q may be non-zero and gk may be a non-zero vector when the distance between the first and second navigation receivers is constrained. 36. The computer program product of claim 35 wherein the distance between the first and second navigation receivers is constrained to a distance LRB, wherein the third set of instructions directs the data processor to generate matrix Sk for the k-th time moment in a form equivalent to: S k = ( 1 - L RB r k ) ( I 3 O 3 × 1 O 1 × 3 0 ) + L RB r k r k r k T where rk is a vector comprising estimates of the three coordinates of the baseline vector at the k-th time moment, and a zero as fourth component, where rkT is the vector transpose of rk, where I3 is the 3-by-3 identity matrix, where O1×3 is a row vector of three zeros, and where P3×1 is a column vector of three zeros; and wherein step (d) generates vector gk for the k-th time moment in a form equivalent to: gk=GTRk−1Qk(QkTRk−1Qk+qSk)−1hk, where: h k = ( 1 - L RB r k ) r k . 37. An apparatus for estimating a set of floating ambiguities associated with a set of phase measurements of a plurality n of satellite carrier signals made by a first navigation receiver (B) and a second navigation receiver (R) separated by a distance, wherein a baseline vector (xo,yo,zo) relates the position of the second receiver to the first receiver, each satellite carrier signal being transmitted by a satellite and having a wavelength, wherein each receiver has a time clock for referencing its measurements and wherein any difference between the time clocks may be represented by an offset, said apparatus receiving, for a plurality of two or more time moments j, the following inputs: a vector γjB representative of a plurality of pseudo-ranges measured by the first navigation receiver (B) and corresponding to the plurality of satellite carrier signals, a vector γjR representative of a plurality of pseudo-ranges measured by the second navigation receiver (R) and corresponding to the plurality of satellite carrier signals, a vector DjB representative of a plurality of estimated distances between the satellites and the first navigation receiver (B), a vector DjR representative of a plurality of estimated distances between the satellites and the second navigation receiver (R), a vector φjB representative of a plurality of full phase measurements of the satellite carrier signals measured by the first navigation receiver (B), a vector φjR representative of a plurality of full phase measurements of the satellite carrier signals measured by the second navigation receiver (R), a geometric Jacobian matrix Hjγ whose matrix elements are representative of the changes in the distances between the satellites and one of the receivers that would be caused by changes in that receiver's position and time clock offset, said apparatus comprising: (a) means for generating, for each time moment j, a vector Δγj of a plurality of range residuals of pseudo-range measurements made by the first and second navigation receivers in the form of: Δγj=(γjR−γjB)−(DjR−DjB); (b) means for generating, for each time moment j, a vector Δφj of a plurality of phase residuals of full phase measurements made by the first and second navigation receivers in the form of: Δφj=(φjR−φjB)−Λ−1·(DjR−DjB), where Λ−1 is a diagonal matrix comprising the inverse wavelengths of the satellites; (c) means for generating, for time moment j=1, an LU-factorization of a matrix M1 or a matrix inverse of matrix M1, the matrix M1 being a function of at least Λ−1 and H1γ; (d) means for generating, for time moment j=1, a vector N1 as a function of at least Δγ1, Δφ1, and the LU-factorization of matrix M1 or the matrix inverse of matrix M1; (e) means for generating, for an additional time moment j≠1, an LU-factorization of a matrix Mj or a matrix inverse of matrix Mj, the matrix Mj being a function of at least Λ−1 and Hjγ; and (f) means for generating, for an additional time moment j≠1, a vector Nj as a function of at least Δγj, Δφj, and the LU-factorization or matrix Mj or the matrix inverse of matrix Mj, the vector Nj having estimates of the floating ambiguities. 38. The apparatus of claim 37 wherein means (c) comprises means for generating an LU-factorization for a matrix comprising a form equivalent to (GTP1G), where: the matrix G has 2n rows, n columns, an upper sub-matrix, and a lower sub-matrix, one of the sub-matrices comprises an n×n zero matrix and the other sub-matrix comprising an n×n identity matrix, the matrix GT comprises the transpose matrix of matrix G, and the matrix P1 has 2n rows, 2n columns, and a form which comprises a matrix equivalent to (R1−1−R1−1Qi(Q1TR1−1Q1+qS1)−1Q1TR1−1) where the matrix R1 is a weighting matrix, where the matrix R1−1 comprises an inverse of matrix R1, where the matrix Q1 has an upper sub-matrix and a lower sub-matrix, one of the sub-matrices of Q1 comprising matrix H1γ and the other of the sub-matrices of Q1 comprising the matrix product Λ−1H1γ, and wherein the matrix Q1T comprises the transpose of matrix Q1, and where the quantity qSk is a zero matrix when the distance between the first and second navigation receivers is unconstrained and where q may be a non-zero weighting parameter and Sk may be a non-zero matrix when the distance between the first and second navigation receivers is constrained. 39. The apparatus of claim 38 wherein means (d) comprises means for generating vector N, to comprise a vector having a form equivalent to M1−1(GTP1μ1+qg1), where the matrix M1−1 comprises an inverse of matrix of matrix M1, and where the vector μ1 comprises the vector [Δγ1, Δφ1]T, and where the quantity qgk is a zero vector when the distance between the first and second navigation receivers is unconstrained and where q may be non-zero and gk may be a non-zero vector when the distance between the first and second navigation receivers is constrained. 40. The apparatus of claim 37 wherein means (e) comprises means for generating an LU-factorization for a matrix comprising a form equivalent to Mj=Mj−1+GTPjG, where: Mj−1 comprises the matrix M1 of generated by means (c) when j=2 and comprises the matrix Mj generated by means (e) for the j−1 time moment when j>2, the matrix G has 2n rows, n columns, an upper sub-matrix, and a lower sub-matrix, one of the sub-matrices comprising an n×n zero matrix and the other sub-matrix comprising an n×n identity matrix, the matrix GT comprises the transpose matrix of matrix G, and the matrix Pj has 2n rows, 2n columns, and a form which comprise a matrix equivalent to (Rj−1−Rj−1Qj(QjTRj−1Qj+qSj)−1QjTRj−1) where the matrix Rj is a weighting matrix, where the matrix Rj−1 comprises an inverse of matrix Rj, where the matrix Qj has an upper sub-matrix and a lower sub-matrix, one of the sub-matrices of Qj comprising matrix Hjγ and the other of the sub-matrices of Qj comprising the matrix product Λ−1Hjγ, and wherein the matrix QjT comprises the transpose of matrix Qj, and where the quantity qSj is a zero matrix when the distance between the first and second navigation receivers is unconstrained and where q may be a non-zero weighting parameter and Sj may be a non-zero matrix when the distance between the first and second navigation receivers is constrained. 41. The apparatus of claim 40 wherein means (f) comprises means for generating vector Nj to comprise a vector having a form equivalent to Nj−1+Mj−1└GTPj(μj−GNj−1)+qgj┘, where the matrix Mj−1 comprises an inverse of matrix of matrix Mj, where the vector μj comprises the vector [Δγj, Δφj]T, and where the vector Nj−1 comprises the vector N1 generated by means (d) when j=2 and comprises the vector Nj−1 generated by means (f) for the j−1 time moment when j>2, and where the quantity qgj is a zero vector when the distance between the first and second navigation receivers is unconstrained and where q may be non-zero and gj may be a non-zero vector when the distance between the first and second navigation receivers is constrained. 42. The apparatus of claim 39 wherein the distance between the first and second navigation receivers is constrained to a distance LRB, wherein means (c) comprises means for generating matrix S1 in a form equivalent to: S 1 = ( 1 - L RB r 1 ) ( I 3 O 3 × 1 O 1 × 3 0 ) + L RB r 1 r 1 r 1 T where r1 is a vector comprising estimates of the three coordinates of the baseline vector for the time moment j=1 and a zero as fourth component, where r1T is the vector transpose of r1, where I3 is the 3-by-3 identity matrix, where O1×3 is a row vector of three zeros, and where O3×1 is a column vector of three zeros; and wherein means (d) comprises means for generating vector g1 for the time moment j=1 in a form equivalent to: g1=GTR1−1Q1(Q1TR1−1Q1+qS1)−1h1, where: h 1 = ( 1 - L RB r 1 ) r 1 . 43. The apparatus of claim 41 wherein the distance between the first and second navigation receivers is constrained to a distance LRB, wherein means (e) comprises means for generating matrix Sj in a form equivalent to: S j = ( 1 - L RB r j ) ( I 3 O 3 × 1 O 1 × 3 0 ) + L RB r j r j r j T where rj is a vector comprising estimates of the three coordinates of the baseline vector for the j-th time moment and a zero as fourth vector component, where rjT is the vector transpose of rj, where I3 is the 3-by-3 identity matrix, where O1×3 is a row vector of three zeros, and where O3×1 is a column vector of three zeros; and wherein means (f) comprises means for generating vector gj for the j-th time moment in a form equivalent to: gj=GTRj−1Qj(QjTRj−1Qj+qSj)−1hj, where: h j = ( 1 - L RB r j ) r j . 44. The apparatus of claim 40 wherein means (e) for generating the LU-factorization of Mj comprises: (g) means for generating an LU-factorization of matrix Mj−1 in a form equivalent to Lj−1 Lj−1T wherein Lj−1 is a low-triangular matrix and Lj−1T is the transpose of Lj−1; (h) means for generating a factorization of GT Pj G in a form equivalent to TjTjT=GTPjG, where TjT is the transpose of Tj; and (i) means for generating an LU-factorization of matrix Mj in a form equivalent to Lj LjT from a plurality n of rank-one modifications of matrix Lj−1, each rank-one modification being based on a respective column of matrix Tj, where n is the number of rows in matrix Mj. 45. The apparatus of claim 44 wherein means (h) generates matrix Tj from a Cholesky factorization of GT Pj G. 46. The apparatus of claim 44 wherein weighting matrix Rj has a form equivalent to: R j = [ R j γ 0 0 R j φ ] , where Rγ and Rφ are weighting matrices; wherein Rγ and Rφ are related to a common weighting matrix W and scaling parameters σγ and σφ as follows ( R γ ) - 1 = 1 σ γ 2 W , and ( R φ ) - 1 = 1 σ φ 2 W , wherein means (h) of generating matrix Tj comprises: means for generating a scalar b in a form equivalent to: b = σ γ 2 λ GPS 2 σ γ 2 + λ GPS 2 σ φ 2 , where λGPS2 is the wavelength of the satellite signals, means for generating a matrix {tilde over (H)} in a form equivalent to {tilde over (H)}=W1/2Hjγ. means for generating a Householder matrix SHH for matrix {tilde over (H)}, and means for generating matrix Tj in a form equivalent to: T j = 1 σ φ W 1 / 2 S HH [ ( 1 - b λ GPS 2 ) I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 I ( n - 4 ) × ( n - 4 ) ] . 47. The method of claim 44 wherein weighting matrix Rj is applied to a case where there is a first group of satellite signals having carrier signals in a first wavelength band and a second group of satellite signals having a carrier signals in a second wavelength band, the weighting frequency having a form equivalent to: R j = [ R j γ 0 0 R j φ ] , where Rγ and Rφ are weighting matrices; wherein Rγ and Rφ are related to a common weighting matrix W, the carrier wavelengths of the first group of signals as represented by matrix Λ(1), the carrier wavelengths of the second group of signals as represented by matrix Λ(2), the center wavelength of the first band as represented by λ1, the center wavelength of the first band as represented by λ2, and scaling parameters σγ and σφ as follows: ( R j γ ) - 1 = [ 1 σ γ 2 W O n × n O n × n 1 σ γ 2 W ] , ( R j φ ) - 1 = [ 1 σ φ 2 W ( 1 ) O n × n O n × n 1 σ φ 2 W ( 2 ) ] , where W ( 1 ) = 1 λ 1 2 Λ ( 1 ) W Λ ( 1 ) , W ( 2 ) = 1 λ 2 2 Λ ( 2 ) W Λ ( 2 ) , wherein step (h) of generating matrix Tj comprises the steps of: generating a scalar b in a form equivalent to: b = σ γ 2 λ 1 2 λ 2 2 2 σ φ 2 λ 1 2 λ 2 2 + σ γ 2 λ 1 2 + σ γ 2 λ 2 2 , where λ1 is the wavelength of a first group of satellite signals and λ2 is the wavelength of a second group of satellite signals, generating a matrix {tilde over (H)} in a form equivalent to {tilde over (H)}=W1/2Hjγ, generating a Householder matrix SHH for matrix {tilde over (H)}, and generating matrix Tj in a form equivalent to: T j = 1 σ φ [ A11 O n × n A21 A22 ] , where sub-matrixces A11, A21, and A22 are as follows: A11 = ( W ( 1 ) ) 1 2 S HH [ 1 - b / λ 1 2 I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 I ( n - 4 ) ] , A21 = ( W ( 2 ) ) 1 2 S HH [ - b λ 1 λ 2 1 - b / λ 1 2 I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 O ( n - 4 ) × ( n - 4 ) ] , and A22 = ( W ( 2 ) ) 1 2 S HH [ 1 - b / λ 1 2 - b / λ 2 2 1 - b / λ 1 2 I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 I ( n - 4 ) ] . 48. An apparatus for estimating a set of floating ambiguities associated with a set of phase measurements of a plurality n of satellite carrier signals made by a first navigation receiver (B) and a second navigation receiver (R) separated by a distance, wherein a baseline vector (xo,yo,zo) relates the position of the second receiver to the first receiver, each satellite carrier signal being transmitted by a satellite and having a wavelength, wherein each receiver has a time clock for referencing its measurements and wherein any difference between the time clocks may be represented by an offset, said apparatus receiving, for a plurality of two or more time moments j, the following inputs: a vector γjB representative of a plurality of pseudo-ranges measured by the first navigation receiver (B) and corresponding to the plurality of satellite carrier signals, a vector γjR representative of a plurality of pseudo-ranges measured by the second navigation receiver (R) and corresponding to the plurality of satellite carrier signals, a vector DjB representative of a plurality of estimated distances between the satellites and the first navigation receiver (B), a vector DjR representative of a plurality of estimated distances between the satellites and the second navigation receiver (R), a vector φjB representative of a plurality of full phase measurements of the satellite carrier signals measured by the first navigation receiver (B), a vector φjR representative of a plurality of full phase measurements of the satellite carrier signals measured by the second navigation receiver (R), a geometric Jacobian matrix Hjγ whose matrix elements are representative of the changes in the distances between the satellites and one of the receivers that would be caused by changes in that receiver's position and time clock offset, said apparatus comprising: (a) means for generating, for each time moment j, a vector Δγj of a plurality of range residuals of pseudo-range measurements made by the first and second navigation receivers in the form of: Δγj=(γjR−γjB)−(DjR−DjB), said means generating a set of range residuals Δγk, k=1, . . . , j; (b) means for generating, for each time moment j, a vector Δφj of a plurality of phase residuals of full phase measurements made by the first and second navigation receivers in the form of: Δφj=(φjR−φjB)−Λ−1·(DjR−DjB), where Λ−1 is a diagonal matrix comprising the inverse wavelengths of the satellites, said means generating a set of phase residuals Δφk, k=1, . . . , j; (c) means for generating an LU-factorization of a matrix M or a matrix inverse of matrix M, the matrix M being a function of at least Λ−1 and Hkγ, for index k of Hkγ covering at least two of the time moments j; (d) means for generating a vector N of estimated floating ambiguities as a function of at least the set of range residuals Δγk, the set of phase residuals Δφk, and the LU-factorization of matrix M or the matrix inverse of matrix M. 49. The apparatus of claim 48 wherein means (c) comprises means for generating matrix M in a form equivalent to the summation [ ∑ k = 1 j ( G T P k G ) ] , where: the matrix G has 2n rows, n columns, an upper sub-matrix, and a lower sub-matrix, one of the sub-matrices comprises an n×n zero matrix and the other sub-matrix comprising an n×n identity matrix, the matrix GT comprises the transpose matrix of matrix G, and the matrix Pk has 2n rows, 2n columns, and a form which comprises a matrix equivalent to Pk=Rk−1−Rk−1Qk(QkTRk−1Qk+qSk)−1QkTRk−1, where the matrix Rk is a weighting matrix, where the matrix Rk−1 comprises an inverse of matrix Rk, where the matrix Qk has an upper sub-matrix and a lower sub-matrix, one of the sub-matrices of Qk comprising matrix Hkγ and the other of the sub-matrices of Qk comprising the matrix product Λ−1Hkγ, and wherein the matrix QkT comprises the transpose of matrix Qk, and where the quantity qSk is a zero matrix when the distance between the first and second navigation receivers is unconstrained and where q may be a non-zero weighting parameter and Sk may be a non-zero matrix when the distance between the first and second navigation receivers is constrained. 50. The apparatus of claim 49 wherein means (d) comprises means for generating matrix N in a form equivalent to: N = M - 1 × [ ∑ k = 1 j ( G T P k μ k + qg k ) ] , where the matrix M−1 comprises an inverse of matrix of matrix M, where the vector μk comprises the vector [Δγk, Δφk]T, and where the quantity qgk is a zero vector when the distance between the first and second navigation receivers is unconstrained and where q may be non-zero and gk may be a non-zero vector when the distance between the first and second navigation receivers is constrained. 51. The apparatus of claim 50 wherein the distance between the first and second navigation receivers is constrained to a distance LRB, wherein means (c) comprises means for generating matrix Sk for the k-th time moment in a form equivalent to: S k = ( 1 - L RB r k ) ( I 3 O 3 × 1 O 1 × 3 0 ) + L RB r k r k r k T where rk is a vector comprising estimates of the three coordinates of the baseline vector at the k-th time moment, and a zero as fourth component, where rkT is the vector transpose of rk, where I3 is the 3-by-3 identity matrix, where O1×3 is a row vector of three zeros, and where O3×1 is a column vector of three zeros; and wherein means (d) generates vector gk for the k-th time moment in a form equivalent to: gk=GTRk−1Qk(QkTRk−1Qk+qSk)−1hk, where: h k = ( 1 - L RB r k ) r k . 52. A computer program to be installed in a computer for controlling the computer to perform the process of estimating a set of floating ambiguities associated with a set of phase measurements of a plurality n of satellite carrier signals made by a first navigation receiver (B) and a second navigation receiver (R) separated by a distance, wherein a baseline vector (xo,yo,zo) relates the position of the second receiver to the first receiver, each satellite carrier signal being transmitted by a satellite and having a wavelength, wherein each receiver has a time clock for referencing its measurements and wherein any difference between the time clocks may be represented by an offset, said method receiving, for a plurality of two or more time moments j, the following inputs: a vector γjB representative of a plurality of pseudo-ranges measured by the first navigation receiver (B) and corresponding to the plurality of satellite carrier signals, a vector γjR representative of a plurality of pseudo-ranges measured by the second navigation receiver (R) and corresponding to the plurality of satellite carrier signals, a vector DjB representative of a plurality of estimated distances between the satellites and the first navigation receiver (B), a vector DjR representative of a plurality of estimated distances between the satellites and the second navigation receiver (R), a vector φjB representative of a plurality of full phase measurements of the satellite carrier signals measured by the first navigation receiver (B), a vector φjR representative of a plurality of full phase measurements of the satellite carrier signals measured by the second navigation receiver (R), a geometric Jacobian matrix Hjγ whose matrix elements are representative of the changes in the distances between the satellites and one of the receivers that would be caused by changes in that receiver's position and time clock offset, said process comprising: (a) generating, for each time moment j, a vector Δγj of a plurality of range residuals of pseudo-range measurements made by the first and second navigation receivers in the form of: Δγj=(γjR−γjB)−(DjR−DjB); (b) generating, for each time moment j, a vector Δφj of a plurality of phase residuals of full phase measurements made by the first and second navigation receivers in the form of: Δφj=(φjR−φjB)−Λ−1·(DjR−DjB), where Λ−1 is a diagonal matrix comprising the inverse wavelengths of the satellites; (c) generating, for time moment j=1, an LU-factorization of a matrix M1 or a matrix inverse of matrix M1, the matrix M1 being a function of at least Λ−1 and H1γ; (d) generating, for time moment j=1, a vector N1 as a function of at least Δγ1, Δφ1, and the LU-factorization of matrix M1 or the matrix inverse of matrix M1; (e) generating, for an additional time moment j≠1, an LU-factorization of a matrix Mj or a matrix inverse of matrix Mj, the matrix Mj being a function of at least Λ−1, Hjγ and an instance of matrix M generated for a different time moment; and (f) generating, for an additional time moment j≠1, a vector Nj as a function of at least Δγj, Δφj, and the LU-factorization or matrix Mj or the matrix inverse of matrix Mj, the vector Nj having estimates of the floating ambiguities. 53. The computer program of claim 52 wherein step (c) of the process comprises generating an LU-factorization for a matrix comprising a form equivalent to (GTP1G), where: the matrix G has 2n rows, n columns, an upper sub-matrix, and a lower sub-matrix, one of the sub-matrices comprises an n×n zero matrix and the other sub-matrix comprising an n×n identity matrix, the matrix GT comprises the transpose matrix of matrix G, and the matrix P1 has 2n rows, 2n columns, and a form which comprises a matrix equivalent to (R1−1−R1−1Q1(Q1TR1−1Q1+qS1)−1Q1TR1−1) where the matrix R1 is a weighting matrix, where the matrix R1−1 comprises an inverse of matrix R1, where the matrix Q1 has an upper sub-matrix and a lower sub-matrix, one of the sub-matrices of Q1 comprising matrix Hjγ and the other of the sub-matrices of Q1 comprising the matrix product Λ−1H1γ, and wherein the matrix Q1T comprises the transpose of matrix Q1, and where the quantity qSk is a zero matrix when the distance between the first and second navigation receivers is unconstrained and where q may be a non-zero weighting parameter and Sk may be a non-zero matrix when the distance between the first and second navigation receivers is constrained. 54. The computer program of claim 53 wherein step (d) of the process comprises the step of generating vector N1 to comprise a vector having a form equivalent to M1−1(GTP1μ1+qg1), where the matrix M1−1 comprises an inverse of matrix of matrix M1, and where the vector μ1 comprises the vector [Δγ1, Δφ1]T, and where the quantity qgk is a zero vector when the distance between the first and second navigation receivers is unconstrained and where q may be non-zero and gk may be a non-zero vector when the distance between the first and second navigation receivers is constrained. 55. The computer program of claim 52 wherein step (e) of the process comprises generating an LU-factorization for a matrix comprising a form equivalent to Mj=Mj−1+GTPjG, where: Mj−1 comprises the matrix M1 of step (c) when j=2 and comprises the matrix Mj of step (e) for the j−1 time moment when j>2, the matrix G has 2n rows, n columns, an upper sub-matrix, and a lower sub-matrix, one of the sub-matrices comprising an n×n zero matrix and the other sub-matrix comprising an n×n identity matrix, the matrix GT comprises the transpose matrix of matrix G, and the matrix Pj has 2n rows, 2n columns, and a form which comprise a matrix equivalent to (Rj−1−Rj−1Qj(QjTRj−1Qj+qSj)−QjTQjTRj−1) where the matrix Rj is a weighting matrix, where the matrix Rj−1 comprises an inverse of matrix Rj, where the matrix Qj has an upper sub-matrix and a lower sub-matrix, one of the sub-matrices of Qj comprising matrix Hjγ and the other of the sub-matrices of Qj comprising the matrix product Λ−1Hjγ, and wherein the matrix QjT comprises the transpose of matrix Qj, and where the quantity qSj is a zero matrix when the distance between the first and second navigation receivers is unconstrained and where q may be a non-zero weighting parameter and Sj may be a non-zero matrix when the distance between the first and second navigation receivers is constrained. 56. The computer program of claim 55 wherein step (f) of the process comprises the step of generating vector Nj to comprise a vector having a form equivalent to Nj−1+Mj−1└GTPj(μj−GNj−1)+qgj┘, where the matrix Mj−1 comprises an inverse of matrix of matrix Mj, where the vector μj comprises the vector [Δγj, Δφj]T, and where the vector Nj−1 comprises the vector N1 generated by step (d) when j=2 and comprises the vector Nj−1 generated by step (f) for the j−1 time moment when j>2, and where the quantity qgj is a zero vector when the distance between the first and second navigation receivers is unconstrained and where q may be non-zero and gj may be a non-zero vector when the distance between the first and second navigation receivers is constrained. 57. The computer program of claim 56 wherein the distance between the first and second navigation receivers is constrained to a distance LRB, wherein step (c) of the process generates matrix S1 in a form equivalent to: S 1 = ( 1 - L RB r 1 ) ( I 3 O 3 × 1 O 1 × 3 0 ) + L RB r 1 r 1 r 1 T where r1 is a vector comprising estimates of the three coordinates of the baseline vector for the time moment j=1 and a zero as fourth component, where r1T is the vector transpose of r1, where I3 is the 3-by-3 identity matrix, where O1×3 is a row vector of three zeros, and where O3×1 is a column vector of three zeros; and wherein step (d) generates vector g1 for the time moment j=1 in a form equivalent to: g1=GTR1−1Q1(Q1TR1−1Q1+qS1)−1h1, where: h 1 = ( 1 - L RB r 1 ) r 1 . 58. The computer program of claim 56 wherein the distance between the first and second navigation receivers is constrained to a distance LRB, wherein step (e) of the process generates matrix Sj in a form equivalent to: Sj = ( 1 - L RB r j ) ( I 3 O 3 × 1 O 1 × 3 0 ) + L RB r j rjrj T where rj is a vector comprising estimates of the three coordinates of the baseline vector for the j-th time moment and a zero as fourth vector component, where rjT is the vector transpose of rj, where I3 is the 3-by-3 identity matrix, where O1×3 is a row vector of three zeros, and where O3×1 is a column vector of three zeros; and wherein step (f) generates vector gj for the j-th time moment in a form equivalent to: gj=GTRj−1Qj(QjTR1−1Qj+qSj)−1hj, where: h j = ( 1 - L RB r j ) r j . 59. The computer program of claim 55 wherein the generation of the LU-factorization in step (e) of the process comprises the steps of: (g) generating an LU-factorization of matrix Mj−1 in a form equivalent to Lj−1 Lj−1T wherein Lj−1 is a low-triangular matrix and Lj−1T is the transpose of Lj−1; (h) generating a factorization of GT Pj G in a form equivalent to TjTjT=GTPjG, where TjT is the transpose of Tj; (i) generating an LU-factorization of matrix Mj in a form equivalent to LjLjT from a plurality n of rank-one modifications of matrix Lj−1, each rank-one modification being based on a respective column of matrix Tj, where n is the number of rows in matrix Mj. 60. The computer program of claim 59 wherein step (h) of the process generates matrix Tj from a Cholesky factorization of GTPjG. 61. The computer program of claim 55 wherein step (d) of the process comprises generating a vector B1 to comprise a vector having a form equivalent to GTP1μ1+qg1, where the vector μ1 comprises the vector [Δγ1, Δφ1]T, and where the quantity qgj is a zero vector when the distance between the first and second navigation receivers is unconstrained and where q may be non-zero and gj may be a non-zero vector when the distance between the first and second navigation receivers is constrained; and wherein step (f) of the process further comprises generating, for each time moment j≠1, a vector Bj to comprise a matrix having a form equivalent to Bj−1+GTPjμj+qgi, where the vector μj comprises the vector [Δγj, Δφj]T, and where the vector Bj−1 is the vector B1 generated by step (d) when j=2 and comprises the vector generated by step (f) for the for the j−1 time moment when j>2, and where the quantity qgj is a zero vector when the distance between the first and second navigation receivers is unconstrained and where q may be non-zero and gj may be a non-zero vector when the distance between the first and second navigation receivers is constrained; and wherein step (f) of the process further comprises generating vector Nj to comprise a vector having a form equivalent to Nj=[Mj]−1Bj, where the matrix Mj−1 comprises an inverse of matrix of matrix Mj. 62. The computer program of claim 61 wherein the distance between the first and second navigation receivers is constrained to a distance LRB, wherein step (c) of the process generates matrix S1 in a form equivalent to: S 1 = ( 1 - L RB r 1 ) ( I 3 O 3 × 1 O 1 × 3 0 ) + L RB r 1 r 1 r 1 T where r1 is a vector comprising estimates of the three coordinates of the baseline vector for the time moment j=1 and a zero as fourth component, where r1T is the vector transpose of r1, where I3 is the 3-by-3 identity matrix, where O1×3 is a row vector of three zeros, and where O3×1 is a column vector of three zeros; and wherein step (d) generates vector g1 for the time moment j=1 in a form equivalent to: g1=GTR1−1Q1(QlTR1−1Q1+qS1)−1hl, where: h 1 = ( 1 - L RB r 1 ) r 1 . 63. The computer program of claim 61 wherein the distance between the first and second navigation receivers is constrained to a distance LRB, wherein step (e) of the process generates matrix Sj in a form equivalent to: Sj = ( 1 - L RB r j ) ( I 3 O 3 × 1 O 1 × 3 0 ) + L RB r j rjrj T where rj is a vector comprising estimates of the three coordinates of the baseline vector for the j-th time moment and a zero as fourth vector component, where rjT is the vector transpose of rj, where I3 is the 3-by-3 identity matrix, where O0×3 is a row vector of three zeros, and where O3×1 is a column vector of three zeros; and wherein step (f) of the process generates vector gj for the j-th time moment in a form equivalent to: gj=GTRj−1Qj(QjTRj−1Qj+qSj)−1hj, where: h j = ( 1 - L RB r j ) r j . 64. A computer program to be installed in a computer for controlling the computer to perform the process of estimating a set of floating ambiguities associated with a set of phase measurements of a plurality n of satellite carrier signals made by a first navigation receiver (B) and a second navigation receiver (R), wherein a baseline vector (xo,yo,zo) relates the position of the second receiver to the first receiver, each satellite carrier signal being transmitted by a satellite and having a wavelength, wherein each receiver has a time clock for referencing its measurements and wherein any difference between the time clocks may be represented by an offset, said method receiving, for a plurality of two or more time moments j, the following inputs for each time moment j: a vector γjB representative of a plurality of pseudo-ranges measured by the first navigation receiver (B) and corresponding to the plurality of satellite carrier signals, a vector γjR representative of a plurality of pseudo-ranges measured by the second navigation receiver (R) and corresponding to the plurality of satellite carrier signals, a vector DjB representative of a plurality of estimated distances between the satellites and the first navigation receiver (B), a vector DjR representative of a plurality of estimated distances between the satellites and the second navigation receiver (R), a vector φjB representative of a plurality of full phase measurements of the satellite carrier signals measured by the first navigation receiver (B), a vector φjR representative of a plurality of full phase measurements of the satellite carrier signals measured by the second navigation receiver (R), a geometric Jacobian matrix Hjγ whose matrix elements are representative of the changes in the distances between the satellites and one of the receivers that would be caused by changes in that receiver's position and time clock offset, the process comprising: (a) generating, for each time moment j, a vector Δγj of a plurality of range residuals of pseudo-range measurements made by the first and second navigation receivers in the form of: Δγj=(γjR−γjB)−(DjR−DjB), said step generating a set of range residuals Δγk, k=1, . . . , j; (b) generating, for each time moment j, a vector Δφj of a plurality of phase residuals of full phase measurements made by the first and second navigation receivers in the form of: Δφj=(φjR−φjB)−Λ−1·(DjR−DjB), where Λ−1 is a diagonal matrix comprising the inverse wavelengths of the satellites, said step generating a set of phase residuals Δφk, k=1, . . . , j; (c) generating an LU-factorization of a matrix M or a matrix inverse of matrix M, the matrix M being a function of at least Λ−1 and Hkγ, for index k of Hkγ covering at least two of the time moments j; (d) generating a vector N of estimated floating ambiguities as a function of at least the set of range residuals Δγk, the set of phase residuals Δφk, and the LU-factorization of matrix M or the matrix inverse of matrix M. 65. The computer program of claim 64 wherein step (c) of the process comprises generating matrix M in a form equivalent to the summation [ ∑ k = 1 j ( G T P k G ) ] , where: the matrix G has 2n rows, n columns, an upper sub-matrix, and a lower sub-matrix, one of the sub-matrices comprises an n×n zero matrix and the other sub-matrix comprising an n×n identity matrix, the matrix GT comprises the transpose matrix of matrix G, and the matrix Pk has 2n rows, 2n columns, and a form which comprises a matrix equivalent to Pk=Rk−1−Rk−1Qk(QkTRk−1Qk+qSk)−1QkTRk−1, where the matrix Rk is a weighting matrix, where the matrix Rk−1 comprises an inverse of matrix Rk, where the matrix Qk has an upper sub-matrix and a lower sub-matrix, one of the sub-matrices of Qk comprising matrix Hkγ and the other of the sub-matrices of Qk comprising the matrix product Λ−1Hkγ, and wherein the matrix QkT comprises the transpose of matrix Qk, and where the quantity qSk is a zero matrix when the distance between the first and second navigation receivers is unconstrained and where q may be a non-zero weighting parameter and Sk may be a non-zero matrix when the distance between the first and second navigation receivers is constrained. 66. The computer program of claim 65 wherein step (d) of the process comprises generating matrix N in a form equivalent to: N = M - 1 × [ ∑ k = 1 j ( G T P k μ k + qg k ) ] , where the matrix M−1 comprises an inverse of matrix of matrix M, where the vector μk comprises the vector [Δγk, Δφk]T, and where the quantity qgk is a zero vector when the distance between the first and second navigation receivers is unconstrained and where q may be non-zero and gk may be a non-zero vector when the distance between the first and second navigation receivers is constrained. 67. The computer program of claim 66 wherein the distance between the first and second navigation receivers is constrained to a distance LRB, wherein step (c) of the process generates matrix Sk for the k-th time moment in a form equivalent to: S k = ( 1 - L RB r k ) ( I 3 O 3 × 1 O 1 × 3 0 ) + L RB r k r k r k T where rk is a vector comprising estimates of the three coordinates of the baseline vector at the k-th time moment, and a zero as fourth component, where rkT is the vector transpose of rk, where I3 is the 3-by-3 identity matrix, where O1×3 is a row vector of three zeros, and where O3×1 is a column vector of three zeros; and wherein step (d) of the process generates vector gk for the k-th time moment in a form equivalent to: gk=GTRk−1Qk(QkTRk−1Qk+qSk)−1hk, where: h k = ( 1 - L RB r k ) r k . 68. The computer program of claim 65 wherein at least one of the weighting matrices Rk comprises an identity matrix multiplied by a scalar quantity. | FIELD OF THE INVENTION The present invention relates to methods of information processing in satellite navigation systems with differential positioning of a mobile user. BACKGROUND OF THE INVENTION Satellite navigation systems, such as GPS (USA) and GLONASS (Russia), are intended for high accuracy self-positioning of different users possessing special navigation receivers. A navigation receiver receives and processes radio signals broadcasted by satellites located within line-of-sight distance. The satellite signals comprise carrier signals that are modulated by pseudo-random binary codes, which are then used to measure the delay relative to local reference clock or oscillator. These measurements enable one to determine the so-called pseudo-ranges (γ) between the receiver and the satellites. The pseudo-ranges are different from true ranges (D, distances) between the receiver and the satellites due to variations in the time scales of the satellites and receiver and various noise sources. To produce these time scales, each satellite has its own on-board atomic clock, and the receiver has its own on-board clock, which usually comprises a quartz crystal. If the number of satellites is large enough (more than four), then the measured pseudo-ranges can be processed to determine the user location (e.g., X, Y, and Z coordinates) and to reconcile the variations in the time scales. Finding the user location by this process is often referred to as solving a navigational problem or task. The necessity to guarantee the solution of navigational tasks with accuracy better than 10 meters, and the desire to raise the stability and reliability of measurements, have led to the development of the mode of “differential navigation ranging,” also called “differential navigation” (DN). In the DN mode, the task of finding the user position is performed relative to a Base station (Base), the coordinates of which are known with the high accuracy and precision. The Base station has a navigation receiver that receives the signals of the satellites and processes them to generate measurements. The results of these measurements enable one to calculate corrections, which are then transmitted to the user that also uses a navigation receiver. By using these corrections, the user obtains the ability to compensate for the major part of the strongly correlated errors in the measured pseudo-ranges, and to substantially improve the accuracy of his or her positioning. Usually, the Base station is immobile during measurements. The user may be either immobile or mobile. We will call such a user “the Rover.” The location coordinates of a moving Rover are continuously changing, and should be referenced to a time scale. Depending on the navigational tasks to be solved, different modes of operation may be used in the DN mode. They differ in the way in which the measurement results are transmitted from the Base to the Rover. In the Post-processing (PP) mode, these results are transmitted as digital recordings and go to the user after all the measurements have been finished. In the PP mode, the user reconstructs his or her location for definite time moments in the past. Another mode is the Real-Time Processing (RTP) mode, and it provides for the positioning of the Rover receiver just during the measurements. The RTP mode uses a communication link (usually it is a radio communication link), through which all the necessary information is transmitted from the Base to the Rover receiver in digital form. Further improvement of accuracy of differential navigation may be reached by supplementing the measurements of the pseudoranges with the measurements of the phases of the satellite carrier signals. If one measures the carrier phase of the signal received from a satellite in the Base receiver and compares it with the carrier phase of the same satellite measured in the Rover receiver, one can obtain measurement accuracy to within several percent of the carrier's wavelength, i.e., to within several centimeters. The practical implementation of those advantages, which might be guaranteed by the measurement of the carrier phases, runs into the problem of there being ambiguities in the phase measurements. The ambiguities are caused by two factors. First, the difference of distances ΔD from any satellite to the Base and Rover is much greater than the carrier's wavelength λ. Therefore, the difference in the phase delays of a carrier signal Δφ=ΔD/λ received by the Base and Rover receivers exceeds several cycles. Second, it is not possible to measure the integer number of cycles in Δφ from the incoming satellite signals; one can only measure the fractional part of Δφ. Therefore, it is necessary to determine the integer part of Δφ, which is called the “ambiguity”. More precisely, we need to determine the set of all such integer parts for all the satellites being tracked, one integer part for each satellite. One has to determine this set along with other unknown values, which include the Rover's coordinates and the variations in the time scales. In a general way, the task of generating highly-accurate navigation measurements is formulated as follows: one determines the state vector of a system, with the vector containing nΣ unknown components. Those include three Rover coordinates (usually along Cartesian axes X, Y, Z) in a given coordinate system (sometimes time derivatives of coordinates are added too); the variations of the time scales which is caused by the phase drift of the local main reference oscillator; and n integer unknown values associated with the ambiguities of the phase measurements of the carrier frequencies. The value of n is determined by the number of different carrier signals being processed, and accordingly coincides with the number of satellite channels actively functioning in the receiver. At least one satellite channel is used for each satellite whose broadcast signals are being received and processed by the receiver. Some satellites broadcast more than one code-modulated carrier signal, such as a GPS satellite that broadcasts a carrier in the L1 frequency band and a carrier in the L2 frequency band. If the receiver processes the carrier signals in both of the L1 and L2 bands, the number of satellite channels (n) increases correspondingly. Two sets of navigation parameters are measured by the Base and Rover receivers, respectively, and are used to determine the unknown state vector. Each set of parameters includes the pseudo-range of each satellite to the receiver, and the full (complete) phase of each satellite carrier signal, the latter of which may contain ambiguities. Each pseudo-range is obtained by measuring the time delay of a code modulation signal of the corresponding satellite. The code modulation signal is tracked by a delay-lock loop (DLL) circuit in each satellite-tracking channel. The full phase of a satellite's carrier signal is tracked by phase counter (as described below) with input from a phase-lock-loop (PLL) in the corresponding satellite tracking channel (an example of which is described below in greater detail). An observation vector is generated as the collection of the measured navigation parameters for specific (definite) moments of time. The relationship between the state vector and the observation vector is defined by a well-known system of navigation equations. Given an observation vector, the system of equations may be solved to find the state vector if the number of equations equals or exceeds the number of unknowns in the state vector. In the latter case, conventional statistical methods are used to solve the system: the least-squares method, the method of dynamic Kalman filtering, and various modifications of these methods. Practical implementations of these methods in digital form may vary widely. In implementing or developing such a method on a processor, one usually must find a compromise between the accuracy of the results and speed of obtaining results for a given amount of processor capability, while not exceeding a certain amount of loading on the processor. The present invention is directed to novel methods and apparatuses for accelerating the obtaining of reliable estimates for the integer ambiguities at an acceptable processor load. More particularly, the present invention is directed to novel methods and apparatuses for more quickly obtaining such estimates in floating-point form (non-integer form) which are close to the integer values. With these floating-point forms, which we call floating ambiguities, conventional methods may be used to derive the corresponding integer ambiguities. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is schmatic diagram of an exemplary receiver which may be used in practicing the present invention. FIG. 2 is a perspective view of a rover station and a base station in a first exemplary coinfiguration according to the present invention. FIG. 3 is a perspective view of a rover station and a base station in a second exemplary coinfiguration according to the present invention. FIG. 4 is a flow diagram illustrating a general set of exemplary embodiments according to the present invention. FIG. 5 is a schematic diagram of an exemplary apparatus according to the present invention. FIG. 6 is a diagram of an exemplary computer program product according to the present invention. FIG. 7 is a flow diagram illustrating another general set of exemplary embodiments according to the present invention. FIG. 8 is a diagram of another exemplary computer program product according to the present invention. SUMMARY OF THE INVENTION Broadly stated, the present invention encompasses methods and apparatuses for estimating the floating ambiguities associated with the measurement of the carrier signals of a plurality of global positioning satellites, such that the floating ambiguities are preferably consist for a plurality of different time moments. The floating ambiguities are associated with a set of phase measurements of a plurality n of satellite carrier signals made by a first navigation receiver (B) and a second navigation receiver (R) separated by a distance, wherein a baseline vector (xo,yo,zo) relates the position of the second receiver to the first receiver. Each satellite carrier signal is transmitted by a satellite and has a wavelength, and each receiver has a time clock for referencing its measurements. Any difference between the time clocks may be represented by an offset. Methods and apparatuses according to the present invention receive, for a plurality of two or more time moments j, the following inputs: a vector γjB representative of a plurality of pseudo-ranges measured by the first navigation receiver (B) and corresponding to the plurality of satellite carrier signals, a vector γjR representative of a plurality of pseudo-ranges measured by the second navigation receiver (R) and corresponding to the plurality of satellite carrier signals, a vector DjB representative of a plurality of estimated distances between the satellites and the first navigation receiver (B), a vector DJR representative of a plurality of estimated distances between the satellites and the second navigation receiver (R), a vector φjB representative of a plurality of full phase measurements of the satellite carrier signals measured by the first navigation receiver (B), a vector φjR representative of a plurality of full phase measurements of the satellite carrier signals measured by the second navigation receiver (R), and a geometric Jacobian matrix Hjγ whose matrix elements are representative of the changes in the distances between the satellites and one of the receivers that would be caused by changes in that receiver's position and time clock offset. (As used herein, the term “representative of,” as used for example used when indicating that a first entity is representative of a second entity, includes cases where the first entity is equal to the second entity, where the first entity is proportional to the second entity, and where the first entity is otherwise related to the second entity.) The present invention may be practiced in real time, where estimates of the floating ambiguities are generated as the above satellite information is being received. The present invention may also be practiced in post-processing mode, where the floating ambiguities are estimated after all the above satellite information has been received. In the latter case, block processing according to the present invention may be done. Preferred methods and apparatuses according to the present invention generate, for each time moment j, a vector Δγj of a plurality of range residuals of pseudo-range measurements made by the first and second navigation receivers in the form of: Δγj=(γjR−γjB)−(DjR−DjB; and also generate, for each time moment j, a vector Δφj of a plurality of phase residuals of full phase measurements made by the first and second navigation receivers in the form of: Δφj=(φjR−φjB)−Λ−1·(DjR−DjB), where Λ−1 is a diagonal matrix comprising the inverse wavelengths of the satellites. In the case of real-time processing, an LU-factorization of a matrix M1, or a matrix inverse of matrix M1, is generated for a first time moment (denoted as j=1), with the matrix M1 being a function of at least Λ−1 and H1γ. Also for this initial time moment, an initial vector N1 of floating ambiguities is generated as a function of at least Δγ1, Δφ1, and the LU-factorization of matrix M1 or the matrix inverse of matrix M1. For an additional time moment j, an LU-factorization of a matrix Mj, or a matrix inverse of matrix Mj, is generated, with the matrix Mj being a function of at least Λ−1 and Hjγ. Also for an additional time moment j, a vector Nj of estimated floating ambiguities is generated as a function of at least Δγj, Δφj, and the LU-factorization or matrix Mj or the matrix inverse of matrix Mj. Exemplary forms of matrices Mj and vectors Nj are provided below. In this manner, a set of successively more accurate estimates of the floating ambiguities are generated in real-time with the vectors Nj. This method, of course, may also be practiced in a post-processing environment, where the data has been previously recorded and then processed according to the above steps. In the post-processing environment, the following block processing approach according to the present invention may be practiced. As with above-described embodiments for real-time processing, the vectors of pseudo-range residuals Δγk and vectors of phase residuals Δφk, k=1, . . . j, are generated. Thereafter, a general matrix M is generated from the data, with M being a function of at least Λ−1 and Hkγ, for index k of Hkγ covering at least two of the time moments j, and an LU-factorization of matrix M or a matrix inverse of matrix M is generated. Thereafter, a vector N of estimated floating ambiguities is generated as a function of at least the set of range residuals Δγk, the set of phase residuals Δφk, and the LU-factorization of matrix M or the matrix inverse of matrix M. As an advantage of the present invention, the nature of matrix M, as described in greater detail below, enables a compact way of accumulating the measured data in order to resolve the floating ambiguities. As a further advantage, forms of matrix M provide a stable manner of factorizing the matrix using previous information. In preferred embodiments, matrix M is substantially positive definite, and also preferably symmetric. Accordingly, it is an objective of the present invention to improve the stability of generating estimates of the floating ambiguities, and a further objective to reduce the amount of computations required to generate estimates of the floating ambiguities. This and other advantages and objectives of the present invention will become apparent to those of ordinary skill in the art in view of the following description. DETAILED DESCRIPTION OF THE PRESENT INVENTION Nomenclature All vectors presented herein are in column form. The transpose of a vector or matrix is indicated by the conventional superscript “T” affixed to the end of the name of the vector or matrix. The inverse of a matrix is indicated by the conventional superscript “−” affixed to the end of the name of the matrix. For the convenience of the reader, we provide a summary notation symbols below: γ—denotes a pseudorange measurement, also called a code measurement; a pseudorange is the approximate distance between a satellite and a receiver is equal to the speed of light c multiplied by the time it takes the satellite signal to reach the receiver. φ—denotes a phase measurement. n—denotes the number of satellites from which measurements are collected S—is a superscript index that is attached to a measurement quantity (e.g., γ, φ) or other data to identify the satellite to which the quantity corresponds. j and k—are subscript indices that are attached to a measurement quantity (e.g., γ, φ) or other data to identify the moment in time (e.g., epoch) to which the measure the quantity corresponds. c—speed of light in air. λS—denotes a wavelength of a carrier signal emitted by the S-th satellite. The wavelength may denote either the L1-band carrier or the L2-band carrier, as indicated by the context of the discussion. Λ—denotes a diagonal matrix of wavelengths: Λ=diag(λ1, . . . , λn). Ol,m or Ol×m—denotes an l×m zero matrix (all matrix elements are zero). The indices l and m take on the appropriate values in the context that the matrix is used. In other words, specific numerical values or other indices may appear in the places of l and m. Il or Il×l—denotes a square identity matrix of size l×l. The index l takes on the appropriate value in the context that the square identity matrix is used. In other words, specific numerical values or other indices may appear in place of l. μ—is a vector of observable equations, preferably linearized observable equations. μ=(Δγ1, . . . , Δγn, Δφ1, . . . , Δφn)T where each element of μ is associated with a corresponding satellite, where the superscript indices affixed to the elements identify the satellites. Hkγ—denotes the observation matrix H associates with the pseudo-ranges γ. In the art, is also called the Jacobian matrix, the Jacobi matrix, the geometric function matrix, the Jacobian geometric matrix, the matrix of directional cosines, and the directional cosine matrix. Hkγ has dimensions of n×4. Qk—denotes a compound matrix formed by Hkγ and Λ as follows: Q k = [ H k γ Λ - 1 H k γ ] , having dimensions of 2n×4. G—denotes a compound matrix G = [ O n , n I n ] formed by the zero matrix On,n and the identity matrix In, having dimensions of 2n×n. The matrix G has many purposes. One purpose is to select the lower-right n×n sub-matrix of a larger 2n×2n matrix as follows: G T CG = C 22 , where C = [ C 11 C 12 C 21 C 22 ] . Hjμ—denotes a compound matrix Hjμ=[Qj|G], which is a 2n×(4+n) matrix, ∥•∥F−1 denotes F−1−weighted norm, ∥X∥F−12=XTF−1X. Brief Background on the Structure of the Satellite Signals Before describing the present invention, we briefly describe the structure of the satellite signals and of a typical receiver suitable for differential navigation applications. Each of the satellites radiates signals in two frequency bands: the L1 band and the L2 band. Two carrier signals are simultaneously transmitted in the L1-band; both carrier signals have the same frequency, but are shifted in phase by π/2 (90°). The first L1 carrier signal is modulated by the clear acquisition C/A-code signal and the second L1 carrier signal is modulated by the precision P-code signal. One carrier signal is transmitted in the L2 band, and uses a different frequency than the L1 carrier signals. The L2 carrier signal is modulated by the same P-code signal used to modulate the second L1 carrier signal. These carrier frequencies are between 1 GHz and 2 GHz in value. Each C/A-code signal and P-code signal comprises a repeating sequence of segments, or “chips”, where each chip is of a predetermined time period (Δ) and has a pre-selected value, which is either +1 or −1. The segment values follow a pseudo-random pattern, and thus the C/A-codes and the P-codes are called pseudo-random code signals, or PR-code signals. Additionally, before each C/A-code signal and P-code signal is modulated onto its respective carrier signal, each code signal is modulated by a low frequency (50 Hz) information signal (so-called information symbols). The approximate distance between a satellite and a receiver is equal to the speed of light c multiplied by the transmission time it takes the satellite signal to reach the receiver. This approximate distance is called the pseudorange γ, and it can be corrected for certain errors to find a corrected distance D between the satellite and the receiver. There is a pseudorage between each visible satellite and the receiver. The transmission time from satellite to receiver is measured with the aid of clocks in the receiver and the satellite, and with the aid of several time scales (i.e., timing marks) present within the received satellite signal. The clocks in the satellites and the receiver are set to substantially the same time, but it is assumed that the receiver clock has a time offset τ because the receiver clock is based upon a quartz-crystal whereas each satellite clock is based upon a more accurate atomic reference clock. The receiver has the orbital patterns of the satellites stored in a memory, and it can determine the orbital position of the satellites based on the time of its clock. The receiver reads the timing marks on the satellite's signal, and compares them against it own clock to determine the transmission time from satellite to receiver. The satellite's low-frequency (50 Hz) information signal provides the least precise timing information, the C/A-code signal provides the next most precise timing information, and the P-code signal provides the most precise timing information. The pseudorange is determined from the low-frequency information signal and the C/A-code signal for civilian users and some military users, and is determined from the low-frequency information signal and the P-code signal for most military users. Accurate use of the P-code signal requires knowledge of a certain code signal that is only known to military users. Precision better than that provided by the P-code signal can be obtained by measuring the phase of the satellite carrier signal in a differential navigation mode using two receivers. Referring to FIG. 1, a typical receiver for differential navigation applications has an antenna, an amplifier/filter unit that receives the antenna's output, a frequency down-conversion unit that receives the output of the amplifier/filter unit, and several individual tracking channels of the coherent type, each of which receives the down-converted satellite signals. The receiver also comprises a receiver clock, which provides base timing signals to the local oscillator of the down-conversion unit, and to components within each individual tracking channel. The down-conversion unit provides down-converted and quantized versions of the satellite signals to the channels, with the down-converted signals having frequencies generally in the range of 10 MHz to 20 MHz. Each channel tracks a selected one of the satellite signals. Each tracking channel measures the delay of one PR-code signal within the satellite signal (e.g., C/A-code or P-code signal), and also the phase of the down-converter version of the satellite's carrier signal. A typical tracking channel comprises a Delay-Lock Loop (DLL) circuit for tracking the delay of the PR-code, a Phase-Lock Loop (PLL) circuit for tracking the phase of the satellite's carrier signal, and three correlators which generate the input signals for the DLL and PLL circuits. Referring to FIG. 1, the DLL circuit has a reference code generator that generates a set of reference code signals, each of which tracks the PR-code of the satellite signal, and each of which is provided as an input to a respective correlator. Each correlator output is representative of the degree to which the reference code signals are tracking the satellite code signal (i.e., the amount by which the reference signals are advanced or retarded in time with respect to the satellite signal). The DLL circuit also has a DLL discriminator and a DLL filter. The DLL discriminator receives inputs from two correlators, a DLL correlator that generates a base signal for controlling the DLL circuit and a main correlator that generates a signal useful for normalizing the base signal from the DLL correlator. The DLL discriminator generates an error control signal from these inputs; this error signal is filtered by the DLL filter before being provided to the DLL reference code generator as a control signal. The value of the DLL error signal varies by the amount that the reference code signals of the DLL generator are delayed or advanced with respect to the satellite code signal being tracked, and causes the code generator to adjust the timing of the reference code signals to better match the satellite's code signal. In this manner, tracking is achieved. The pseudorange γ may be generated by methods known to the art from the receiver's clock, the 50 Hz information signal, and any one of the reference code signals generated by the DLL. This is indicated in the “γj(Tj)” box. In a similar manner, the PLL has a reference carrier generator that generates a reference carrier signal that tracks the down-converter version of the satellite's carrier signal. We denote the frequency of the reference carrier signal as fNCO since the reference carrier frequency is often generated by a numerically-controlled oscillator (NCO) within the reference carrier generator. Referring to FIG. 1, the PLL circuit also has a PLL discriminator and a PLL filter. The PLL discriminator receives inputs from two correlators, a PLL correlator that generates a base signal for controlling the PLL circuit, and the main correlator that generates a signal useful for normalizing the base signal from the PLL correlator. Each correlator output is representative of the degree to which the reference carrier signal is tracking the satellite's carrier signal (i.e., the amount by which the reference carirer signal is advanced or retarded in time with respect to the satellite's carrier signal). The PLL discriminator generates an error control signal from these inputs; this error control signal is filtered by the PLL filter before being provided to the PLL reference carrier generator as a control signal. The value of the PLL error signal varies by the amount that the reference carrier signal of the PLL reference carrier generator is delayed or advanced with respect to the satellite carrier signal being tracked, and causes the reference carrier generator to adjust the timing of the reference carrier signal to better match the satellite's carrier signal. The reference carrier generator provides a phase signal φjNCO(Tj) representative of the phase (integrated frequency) of the PLL's reference oscillator. This signal may be combined with other information, as described below, to provide a signal representative of the full phase of the satellite signal (but possibly with ambiguities in it). This is indicated in the “φj(Tj)” box. Finally, each individual tracking channel usually comprises a search system which initially varies the reference signals to bring the PLL and DLL circuits into lock mode. The construction of this and the other above components is well known to the art, and a further detailed description thereof is not needed in order for one of ordinary skill in the art to make and use the present invention. Brief Background on the Navigation Parameters. Because of the time offset τ and other error effects, the pseudorange γ between a satellite and a receiver is usually not the actual distance between the satellite and the receiver. By looking at the pseudoranges of four or more satellites, there are well-known methods of estimating the time offset τ of the receiver and of accounting for some of the error effects to generate the computed distance D between the satellites and the receiver. The receiver's position may then be computed. However, because of various sources of noise and the relatively low resolution of the pseudo-random code signal, the true distances (i.e., true ranges), and receiver's position coordinates will not be exactly known, and will have errors. In theory, more precise values for the receiver's position and clock offset could be obtained by measuring the number of carrier cycles that occur between each satellite and the receiver. The phase of the carrier of the satellite signal as transmitted by a satellite can be expressed as: ϕ S ( t ) = Φ 0 S + ∫ 0 t f S · ⅆ t = Φ 0 S + f S · t ( 2 ) where Φ0S is an initial phase value, fS is the satellite carrier frequency, and t is the satellite's time. Because the satellite carrier frequency is generated from a very precise time base, we may assume that fS is a constant and not time dependent, and we may replace the above integral with fS·t, as we have shown in the second line in the above equation. The phase of this signal when it reaches the receiver's antenna over the range distance D(t) is denoted as φSA(t), and its value would be: ϕ A S ( t ) = ϕ S ( t - D ( t ) / c - τ ATM ( t ) ) = Φ 0 S + f S · ( t - D ( t ) / c - τ ATM ( t ) ) = Φ 0 S + f S · t - f S · D ( t ) / c - f S · τ ATM ( t ) , ( 3 ) where c is the speed of light, and where τATM(t) is a delay due to anomalous atmospheric effects which occur mostly in the upper atmosphere. The number of cycles fS·τATM(t) due to the atmospheric effects cannot be predicted or determined to within an accuracy of one carrier cycle by a stand-alone receiver (i.e., cannot be determined by absolute positioning). However, the atmospheric effect can be substantially eliminated in a differential GPS mode where the phase of the satellite is measured at a rover station and a base station, ΦSA,R(t) and ΦSA,B(t) respectively, and then subtracted from one another. Over the short baseline between the rover and base stations, the atmospheric delay τATM(t) in both of these phases is equal for practical purposes, and the difference in phases is: φSA,R(t)−φSA,B(t)=fS·DR(t)/c−fS·DB(t)/c. (4) The terms Φ0S and fS·t have also been cancelled from the difference. In FIG. 2, we show a base station, a rover station, and four satellites, in schematic form. The wave fronts of the satellite carrier signal are nearly planar by the time they reach the base and rover stations since the satellites are at least 22,000 km away. These wave fronts are illustrated in FIG. 2 for the first and fourth satellites (S1 and S4). Assuming that a wave front of the satellite carrier reaches one of the antennas first (either rover or base), the above difference is the number of additional wave fronts that the satellite carrier must travel before it reaches the second antenna (either base or rover). We have illustrated this for the first satellite S1 as fS1·DR(t)/c−fS1·DB(t)/c. Using the angle between the base-rover baseline vector and the line-of-sight vector to the satellite from either of the stations, the number of carrier cycles that lie along the baseline can be determined by trigonometry, and thus the baseline can, in theory, be accurately determined from the differential phase. However, the task of measuring carrier phase is not as easy as it appears. In practice, we must use non-ideal receivers to measure the phases φSA,R(t) and φSA,B(t), with each receiver having a different clock offset with respect to the GPS time, and with each receiver having phase errors occurring during the measurement process. In addition, at the present time, it is not practical to individually count the carrier cycles as they are received by the receiver's antenna since the frequency of the carrier signal is over 1 GHz. However, the PLL loop can easily track the Doppler-shift frequency fD of the carrier signal, which is in the kHz range. With a few assumptions, the phases φSA,R(t) and φSA,B(t) can be related to their respective Doppler-shift frequencies. As is known in the art, the satellite transmits at a fixed frequency of fS, but the relative motion between the satellite and receiver causes the frequency seen by the receiver to be slightly shifted from the value of fS by the Doppler frequency fD. We may write the frequency seen by the receiver's antenna as fS+fD, where fD has a positive value when the distance between the satellite and receiver's antenna is shrinking, and a negative value when the distance is increasing. Each receiver can then assume that the received phase is proportional to the predictable amount of fS·t, minus the amount fD·t due to the Doppler-shift. The Doppler amount fD·t is subtracted from fS·t because the Doppler frequency increases as the distance between the satellite and receiver's antenna decreases. The predictable amount fS·t will be the same for each receiver, but the Doppler frequencies will usually be different. As previously mentioned with reference to FIG. 1, the reference oscillator (e.g., NCO) of the PLL circuit tracks the frequency of a selected one of the down-converted satellite signals. As a result, it inherently tracks the Doppler-shift frequency of the satellite's carrier signal. Before being provided to the PLL circuit, the carrier signal is down-converted from the GHz range by a local oscillator having a frequency fL. The frequency seen by the PLL circuit is (fS+fD)−fL, which can be rearranged as: (fS−fL)+fD. The quantity (fS−fL) is known as the pedestal frequency fp, which is typically around 10 MHz to 20 MHz. The PLL's reference oscillator tracks the down-converted frequency of fp+fD. We would like to integrate the frequency of the reference oscillator to obtain a phase observable which is proportional to −fD·t. Starting at a time moment Tp when the PLL circuit initially locks onto the down-converted satellite signal, with the time moment Tp being measured by the receiver's clock, we will generate a phase observable φj(Tj) at discrete time moments Tj of the receiver's clock T as follows: φj(Ti)=fp,nom·(Tj−Tp)−φjNCO(Tj) (5) where fp,nom is the nominal value of the pedestal frequency, and where φjNCO(Tj) is the phase (integrated frequency) of the PLL's reference oscillator (e.g., NCO). The time moments Tj are spaced apart from each other by a time interval ΔTj, as measured by the receiver's clock, and may be express as Tj=j·ΔTj, where j is an integer. φj(Tj) is in units of cycles, and is proportional to the negative of the integrated Doppler-shift frequency. This is because φjNCO(Tj) changes value in proportional to the quantity (fp+fD)·(Tj−Tp). While it may be possible to set φjNCO(Tp) to any value at the initial lock moment Tp, it is preferably to set φjNCO(Tp) to a value substantially equal to (fp,nom·Tp−fS·{tilde over (D)}p/c), where Tp is measured from the start of GPS time, and where {tilde over (D)}P is the approximate distance between the satellite and the receiver, as found by the pseudorange measured by the DLL, or as found by a single point positioning solution. This setting of φjNCO(Tp) is conventional and provides values of φj(Tj) for the base and rover stations which are referenced from the same starting time point. In U.S. Pat. No. 6,268,824, which is commonly assigned with the present application, it is shown how the observable φj(Tj) is related to the distance D between the receiver and the satellite. We summarize the relationship here, neglecting the atmospheric delay τATM(tj) since this delay will be canceled out when we take the difference between receivers, and refer the reader to the patent for the derivation: φj(Tj)=fS·Dj/c+fS·(τj−Tp)+(φ′0−Φ0S)−Nnco−ζφj (6) where fS is the satellite carrier frequency, Dj is the distance between satellite and receiver at time moment Tj, c is speed of light in the atmosphere, τj is the offset between the satellite time clock t and the receiver time clock T (Tj=tj+τj), τj varies with time, Tp is the time moment when the PLL circuit initially locks onto the down-converted satellite signal, φ′0=ΦLO+fL,nom·Tp, where ΦLO is the phase offset of the receiver's local oscillator and fL,nom is the nominal frequency of the receiver's local oscillator, Φ0S is an initial phase value of the satellite, Nneo is an unknown integer number of carrier cycles due to the PLL not knowing which carrier cycle it first locks onto, Nnco may be positive or negative, and ζφj is a small tracking error due to the operation of the PLL circuit. As it turns out, if we chose the time increments ΔTj for Tj (Tj=j·ΔTj) to be equal to ΔTj=2 ms or an integer multiple of 2 ms, then the term −fS·Tp is an integer number which can be consolidated with the integer ambiguity −Nnco into a single ambiguity +N. φj(Tj)=fS·Dj/c+fS·τj+(φ′0−Φ0S)+N−ζφj (7) Thus, our Doppler phase observable φj(Tj) has been related to the distance Dj between the satellite and receiver, the time offset τj of the receiver, an integer ambiguity N, and some initial phase offsets (φ′0−Φ0S) which can be readily determined. We will now write equation (7) for the base and rover stations, adding superscripts “B” and “R” for the base and rover stations, and subscript “m” to indicate the m-th satellite signal and the m-th individual tracking channel. φj,mB(Tj)=fS·Dj,mB/c+fS·τjB+(φ′0R−Φ0S)+NmB−ζφj,mB (8A) φj,mR(Tj)=fS·Dj,mR/c+fS·τjR+(φ′0R−Φ0S)+NmR−ζφj,mR (8B) For the differential navigation mode, the difference of these phases is formed: ϕ j , m B ( T j ) - ϕ j , m R ( T j ) = f S · D j , m B / c - f S · D j , m R / c + f S · ( τ j B - τ j R ) + ( N m B - N m R ) + ( ϕ 0 ′ B - ϕ 0 ′ R ) - ( ζ ϕ j , m B - ζ ϕ j , m R ) ( 9 ) Using Nm=(NmB−NmR) to represent the difference between the ambiguities, and using the well-known relationship fS/c=1/λm, where λm is the wavelength of the satellite carrier signal, we have: ϕ j , m B ( T j ) - ϕ j , m R ( T j ) = ( 1 / λ m ) · ( D j , m B - D j , m R ) + f S · ( τ j B - τ j R ) + N m + ( ϕ 0 ′ B - ϕ 0 ′ R ) - ( ζ ϕ j , m B - ζ ϕ j , m R ) ( 10 ) The values for φ′0B and φ′0R can be readily determined. The values of ζφj,mB and ζφj,mR cannot be determined, but they have zero mean values (and should average to zero over time). Now, we relate this back to the initial objective and problem that we expressed with respect to FIG. 2. As indicated, we wanted to find the phase difference quantity (fS·DR(t)/c−fS·DB(t)/c) associated with each satellite in order to determine the number of carrier cycles that lie along the baseline, and thus provide a better estimate of the coordinates of the baseline. By examination of the phase difference quantity and equations (9) and (10), we seek that (fS·DR(t)/c−fS·DB(t)/c) is equal to φj,mB(Tj)−φj,mR(Tj), which we can measure, minus the cycle ambiguity Nm, minus the error in the clocks fS·(τjB−τjR), minus the phase offsets (φ′0B−φ′0R), and minus the errors (ζφj,mB−ζφj,mR), the last of which can be removed by averaging. Thus, estimating the cycle ambiguities N will be important in using the phase information to improve the estimated coordinates of the baseline. Our Inventions Related to Ambiguity Resolution—Estimating Floating Ambiguities Our inventions can be applied to a number of application areas. In general application areas, the rover and base stations can move with respect to one another. In one set of specific application areas, the base and rover stations are fixed to a body or vehicle (e.g., planes and ships) and separated by a fixed distance L, as shown in FIG. 3. We refer to these applications as the constant distance constraint applications. The movement of the vehicle may be arbitrary while the distance between two antennas is held constant due to the rigidity of the vehicle body. This distance LRB is known with a certain degree of confidence is considered as an additional constraint or measurement available at every time instant, because it depends on both Base and Rover positions. The constraint can be mathematically expressed as: ((xR−xB)2+(yR−yB)2+(zR−zB)2)1/2=LRB (11) where xR, yR, and zR, represent the rover station coordinates and where xB, yB, and zB represent the base station coordinates. The information from the constraint can be used to better estimate the Rover position relative to the Base. For this, it is preferably to form a cost penalty function mathematically equivalent to the form: F ( x R - x B , y R - y B , z R - z B ) = 1 2 ( ( ( x R - x B ) 2 + ( y R - y B ) 2 + ( z R - z B ) 2 ) 1 2 - L RB ) 2 ( 12 ) where, in preferred embodiments, the cost function F(*) will be minimized such that and its the first derivatives with respect to the rover coordinates (or alternatively the base coordinates) are reduced to values near zero: F (* ) ≈ 0 , ∂ F ∂ x R ≈ 0 , ∂ F ∂ y R ≈ 0 , ∂ F ∂ z R ≈ 0 In the preferred methods described below, the amount of weighting given to minimizing the cost function F(*) will set by a weighting parameter q (e.g., q·F(*)), with no weighting being given when q=0, and increasing degrees of weighting being given by selecting q>0. The case of setting q=0 is also equivalent to removing the constraint that the rover and base stations are separated by a fixed distance L. The ambiguity resolution task generally comprises the following three main parts: 1. Generation of the floating ambiguity estimations (estimating the floating ambiguities), 2. Generation of the integer ambiguities, and 3. Formation of a signal of integer ambiguities resolution. The present invention pertains to the first part, that of generating the floating ambiguity estimates. The second and third parts may be accomplished by apparatuses and methods known in the art. The apparatuses and methods of our present invention use as an input data: (a) the pseudo-ranges and full phase measurements obtained in the Base and Rover receivers; (b) the satellites coordinates (which are highly predictable can be readily determined from the GPS time and information provided in the 50 Hz low-frequency information signal by methods well known to the art); (c) the estimated coordinates of the Base and Rover stations (as measured at their antennas); which may be generated from then pseudo-range data by single point solutions, and oftentimes the coordinates of the base station are precisely known; (d) optionally, a set of weight coefficients characterizing the accuracy of the measurements; and (e) optionally, an estimate rj′ of the baseline coordinates rj and the value of LRB if the cost function F(*) is used. According to the input data, a vector of observations and a covariance matrix of measurements are formed. After that a state vector is generated, components of which are floating ambiguities, the number of which is equal to the number of satellites. On the basis of the floating ambiguity values, a search of the integer ambiguities is performed with use of a least-squares method that is modified for integer estimations. Improvement of the floating ambiguity estimations can take place step-by-step, and the probability of correct ambiguity resolution increases step-by-step as information is accumulated. Preferred finishing of this process is registered by appearance of the signal of integer ambiguities resolution, which indicates that ambiguity resolution was performed sufficiently safely. After that, the integer ambiguities together with other input data are used for accurate determination of the base line vector. The tasks of determining the integer ambiguities and of generating the signal of integer ambiguities resolution are known to the art and do not form part of our invention. These tasks, therefore, are not described in greater detail. Our invention is suitable for both the RTP mode and for the PP mode under movable Rover, where the Rover coordinates may be random and independent in adjacent clock moments. Our invention is also suitable for both the RTP mode and for the PP mode when both the base and rover stations are moving, where the coordinates of the stations may be random, but constrained by fixed distance LRB, in adjacent clock moments. We start by rewriting equation (10), which has the integer ambiguities Nm in vector form: ϕ j B ( T i ) - ϕ j R ( T i ) = Λ - 1 · ( D j B - D j R ) + f S · ( τ j B - τ j R ) + N + ( ϕ 0 ′ B - ϕ 0 ′ R ) - ( ζ ϕ j B - ζ ϕ j R ) , ( 13 ) where Λ1 is a diagonal matrix of inverse wavelengths. We note that the components of (φ′0B−φ′0R) can be selected to be integer constants, and can therefore be incorporated into the integer ambiguities N, which may be called the modified integer ambiguities N. Thus, we may simplify the above equation: φjB(Tj)−φjR(Tj)=Λ−1·(DjB−DjR)+fS·(τjB−τjR)+N−(ζφjB−ζφjR) (14) After this modified N are found, the “true” N may be found by subtracting (φ′0B−φ′0R) from the modified N. As an alternative equivalent to the above, the vector (φ′0B−φ′0R) can be computed and carried over to the left-hand side of equation (14) and subtracted from (φjB(Ti)−φjR(Ti)). As such, the N that is determined will be the “true” N. Once the “true” N is found, then the underlying unknown integer number of carrier cycles Nnco may be found by negating the “true” N (i.e., multipling by −1) and then subtracting fS·Tp (Nnco=−“true” N−fS·Tp). However, for the ultimate goal of computing more accurate coordinates of the baseline, the modified ambiguities N in equation (14) can be used, and they greatly simplify the computations. Nonetheless, it will be appreciated that the present invention may be practiced by using the “true” N or Nnco in equation (14) by suitable modification of the left-hand side of equation (14), and that the appended claims cover such practices. Our approach comprises solving the above equations (14) at a plurality of time moments jointly to find an estimation for vector N. We cannot readily find measured values for vectors τjB, τjR, ζφjB, and ζφjR, and we have some errors in the range vectors DjB nd DjR. Our approach is to represent (model) the errors in the range vectors DjB and DjR and the terms fS·(τjB−τjR)−(ζφjB−ζφjR) by the following error vector: Λ−1·Hjγ·[Δx, Δy, Δz, c·Δτ]T, where Hjγ is the Jacobian matrix (e.g., directional cosine matrix), and where [Δx, Δy, Δz, c·Δτ]T are corrections to the baseline coordinates and clock offsets of the receivers. Thus, we will model the above equation as: (φjR−φjB)−Λ−1·(DjR−DjB)=N+Λ−1·Hjγ·[Δx, Δy, Δz, c·Δτ]T (15) The pseudoranges will be used to estimate the vector Hjγ·[Δx, Δy, Δz, c·Δτ]T as follows: (γjR−γjB)−(DjR−DjB)=Hjγ·[Δx, Δy, Δz, c·Δτ]T (16) This will be done through the formation of observation vectors, state vectors, and observation matrices, and an estimation process over a plurality of time moments, as described below in greater detail. Vector N will be jointly estimated in this process. Generation of the Vector of Observations. A vector of observations μj is generated at each clock time moment μj=j·ΔTJ and comprises 2·n components, where n is the number of the satellite channels. The first n components are the residuals of the single differences of the Base and Rover pseudo-ranges, which we denote in vector form as Δγj: Δγj=γj−Dj (17) with γj=γjR−γjB, and Dj=DjR−DjB; and where γjR and γjB are vectors containing the pseudo-ranges of the satellites, measured in the Base and Rover receivers, respectively; and DjR and DjB are vectors of the estimated ranges of the satellites from Base and Rover stations at the moment of j-th signal radiation DjR and DjB are computed from the known positions of the satellites, the estimated position of the rover, and the known or estimated position of the base station by standard geometry. The next n components of the observation vector μj are the residuals of the single differences of the Base and Rover full phases (Δφj), which we indicate here in vector form: Δφj=φj−Λ−1·Dj (18) where φj=φjR−φjB; φjR and φjB are vectors of the full phases of the given satellite signal, measured at the Base and Rover receivers, respectively (the phases are measured in cycles); and Λ−1 is a diagonal matrix of inverse wavelengths, where each diagonal component corresponds to a channel and is equal to 1/λ, where λ is the wavelength of the carrier signal in the given channel. The full phase vectors φBj and φRj may be constructed in the form provided by equation (5): φBj(Tj)=fp,nom·(Tj−TpB)−φBj,NCO(Tj), φRj(Tj)=fp,nom·(Tj−TpR)−φRj,NCO(Tj), or may be constructed in the form which includes the phase offsets of the base receiver: φBj(Tj)=[fp,nom·(Tj−TpB)−φBj,NCO(Tj)]−φ′0B, φRj(Tj)=[fp,nom·(Tj−TpR)−φRj,NCO(Tj)]−φ′0R, In either case, we will use the convention practice and have the base receiver correct its clock so that the base time Tj will be equivalent to the GPS time tj for the purposes of implementing our inventions (the time offset has already been accounted for in the above equations). For all practical purposes, times Tj and tj will refer to the same processing time increment, and can be interchanged in the above equations. State Vector Representation. The forms represented by Equations (15)-(18) maybe represented in matrix form equivalent to: μj=Hjμ·Aj, (19) where vector Aj is a state vector related to observation matrix μj, and where matrix Hjμ is an observation matrix that specifies the relationship between the components of the observations vector μj and the state vector Aj. State vector vector Aj comprises (4+n) components. The first three components are increments (Δx, Δy, Δz) to the coordinates (xo, yo, zo) of the baseline vector unknown at the j-th clock moment, the fourth component is the unknown increment of the reference oscillator phases (c·Δτ). The remaining n components are the unknown floating ambiguities, different in different channels (N1, N2 . . . Nn). Matrix Hjμ comprises 2n rows and (4+n) columns, and may be divided into the following 4 parts (sub-matrices): H j μ = [ H j γ 0 n × n Λ - 1 · H j γ I n ] . ( 20 ) The first part, the left upper corner of this matrix (the first four columns by the first n rows), is occupied by the observation matrix Hjγ relating to the pseudo-range measurements, each row corresponding to one channel (from the 1-st to the n-th). For the n-th channel, the corresponding row appears like this: [αjn, βjn, hjn, 1], where αjn, βjn, hjn—the directional cosines of the range vector to the n-th satellite from Rover for the j-th time moment. Methods of computing directional cosines are well known to the art and a description thereof herein is not needed for one of ordinary skill in the art to make and use the present invention. The second part of matrix Hjμ, the left lower corner (the first four columns by the last n rows), is occupied by the matrix product Λ−1·Hjγ relating to the full phase measurements, each row corresponding to one channel (from the 1-st to the n-th). For the n-th channel, the corresponding row appears like this: [αjn/λn, βjn/λn, hjn/λn, 1/λn], where λn is the wavelength of the carrier signal in the n-th channel. The third part of matrix Hjμ, the right upper corner (the last n columns by the first n rows) is occupied by zeroes. And the fourth part, the right lower corner (the last n rows by the last n columns) is occupied by the elements relating to the floating ambiguities. This part represents the identity matrix In with dimensions of n×n. For the discussion that follows below, it will be convenient to identified sub-blocks of matrix Hjμ as follows Hjμ=[Qj|G], where Qj is a compound matrix formed by Hjγ and Λ as follows: Q j = [ H j γ Λ - 1 H j γ ] ( having dimensions of 2 n × 4 ) , and where G is a compound matrix the zero matrix On×n and the identity matrix In as follows: G = [ 0 n × n I n ] ( having dimensions of 2 n × n ) . Equation (18) has 2n equations (according to the number of components of the observation vector), and may be used to determine the state vector Aj at the j-th clock moment (i.e., to determine 4+n unknown values). Solution of such a system of equations at n≧4 may be performed by the method of least squares. However, our invention relates to solving for the ambiguity vector N, which is a component of Aj, over a plurality of time moments. Before we describe that process, however, we want to first describe the groundwork of how we can integrate the minimization of the cost function F(*) for constrained distance between receivers, if used, with the solution of Equation (19), and to then describe some covariance matrices that characterize the accuracy of the measured data used to generate μj. These covariance matrices are helpful to our invention, but not strictly necessary. The cost function F(*) may be expressed in the following form: F ( r j + a j ) = 1 2 ( ( ( x j ∘ + Δ x j ) 2 + ( y j ∘ + Δ y j ) 2 + ( z j ∘ + Δ z j ) 2 ) 1 / 2 - L RB ) 2 where: a j = ( Δ x j Δ y j Δ z j c · Δ τ j ) is a vector of the first four components of A j . and r j = ( x j ∘ y j ∘ z j ∘ 0 ) is a vector of the coordinates of the baseline vector , with a zero as the four vector component. Using a second-order truncation of the Taylor series expansion, the cost function F(*) may be approximated as: F ( r j + a j ) - F ( r j ) ≈ a j T ∂ F ∂ r + 1 2 a j T ∂ 2 F ∂ r 2 a j = a j T h j + 1 2 a j T S j a j ( 21 ) where h j = ( 1 - L RB r j ) r j , and ( 22 ) S j = ( 1 - L RB r j ) ( I 3 O 3 × 1 O 1 × 3 0 ) + L RB r j r j r j T . ( 23 ) Because forms (21)-(23) share common variables with equation (18), the minimization of q·F(*) can be integrated with the solution of equation (18), as described below in greater detail. Generation of the Measurements Covariance Matrix. Measurements covariance matrix RJ is preferably formed in the following way on the basis of weight coefficients obtained in Base and Rover receivers: R j = [ R j γ 0 n × n 0 n × n R j φ ] , ( 24 ) where R j γ = [ ( K j , 1 γ ) - 1 0 ⋯ 0 0 ( K j , 2 γ ) - 1 ⋯ 0 ⋮ ⋮ ⋰ ⋮ 0 0 ⋯ ( K j , n γ ) - 1 ] , and R j φ = [ ( K j , 1 φ ) - 1 0 ⋯ 0 0 ( K j , 2 φ ) - 1 ⋯ 0 ⋮ ⋮ ⋰ ⋮ 0 0 ⋯ ( K j , n φ ) - 1 ] . ( 25 ) The weight coefficients (Kj1γ, Kj2γ, . . . , Kjnγ) characterize the accuracy of the measurements of the residuals Δγj of the pseudo-range single differences for the corresponding satellite channels (1-st, 2-nd, . . . , n-th). The generation of the weight coefficients is not a critical part of the present invention, and one may use his particular method of weighting. We present here one of our ways, where each of these coefficients may be determined according to the weight coefficients measured in each channel by Base and Rover receivers for the pseudo-ranges, i.e., by values KjγB and KjγR. Thus, for example, for the n-th channel: (Kjnγ)−1=(KjnγB)−1+(KjnγR)−1, where KjγB and KjγR are determined taking into account the measured signal-to-noise ratio in the receivers and the satellite elevation angles in the n-th channel (of Base and Rover, respectively). Specifically, for each of the receivers (no superscript used), Kj,mγ=Zk,m2·sin(ξk,m−ξmin)·σγ2 when ξk,m>ξmin, and Kj,mγ=0 when ξk,m≦ξmin, where Zk,m2 is the signal strength of the m-th satellite carrier signal as received by the receiver (it has been normalized to a maximum value and made dimensionless), where ξk,m is the elevation angle of the m-th satellite as seen by the receiver, where a minimum elevation angle ξBmin at which the signal becomes visible at the receiver, where σγ2 is the variance of the code measurements (σγ≈1 m). The factor Zk,m2·sin(ξk,m−ξmin) is dimensionless. Weight coefficients Kj1φ, Kj2φ, . . . , Kjnφ characterize the accuracy of the measurements of the residuals Δφj of the phase single differences, and are determined similarly. Here the same input data is used: the signal-to-noise ratio and the angle of elevation, but another scale for the phase measurements is considered (e.g., σφ2 instead of σγ2). Specifically, for each of the receivers (no superscript used), Kj,mφ=Zk,m2·sin(ξk,m−ξmin)·σφ2 when ξk,m>ξmin, and Kj,mφ=0 when ξk,m≦ξmin, where Zk,m2, ξk,m and ξBmin are as they are above, and where σφ2 is the variance of the code measurements (σφ≈1 mm). When the magnitudes of either of weight coefficients Kj,mγB or Kj,mγR is less than a first selected small threshold value, the value of Kj,mγ is generated as a first small number which is less than the first threshold value. This is equivalent to setting (Kj,mγ)−1 to a large number equal to the inverse of the first small number. Similarly, when the magnitudes of either of weight coefficients Kj,mφB or Kj,mφR is less than a second selected small threshold value, the value of Kj,mφ is generated as a second small number which is less than the second threshold value. This is equivalent to setting (Kj,mφ)−1 to a large number equal to the inverse of the second small number. In some instances, satellite signals are blocked from view and should be excluded from the ambiguity resolution process. The elements of the covariance matrix Rj corresponding to these satellite signals are replaced by a very large number. The very large number is selected in advance, and has a value which exceeds by several orders of magnitude the nominal values of the covariance matrix components (Kjγ)−1 or (Kjφ)−1 encountered during operation. Consequently, in further computations, the weights of all measurements relating to these channels become so small that they do not influence the result. As a more simple approach, but currently less preferred, one can use the following form of covariance matrix Rj, or a scaled version thereof: R j = [ 1 σ γ 2 · I n × n 0 n × n 0 n × n 1 σ φ 2 · I n × n ] . This form gives an equal weighting of 1/σγ2 of to the rows of pseudorange data provided by Δγj, and an equal weighting of 1/σφ2 to the rows of phase data provided by Δφj. When a satellite is blocked from view or not visible, the elements of the covariance matrix Rj corresponding to the satellite are preferably replaced by a very large number, as described above. Central Aspects of the Present Invention Summarizing equation (19), the linearized measurement model at the j-th epoch takes the form: H j µ A j = µ j , A j = ( Δ x j Δ y j Δ z j c · Δ τ j N j ) = ( a j N j ) ( 26 ) We expect that the vector of floating ambiguities Nj will be constant in time, and therefore we will drop the subscript index j. Instead, we will denote Nj the evaluation of N obtained through the epoch from 1 to j. Generation of the Floating Ambiguity Estimations We create the following scalar quantity J in equation (27) which integrates the minimization of equation (26) with the minimization of the truncated cost functions Fk for the constrained distance condition (if used) according to equations (21)-(23): J = 1 2 ∑ k = 1 j H k μ A k - µ k R k - 1 2 + q ∑ k = 1 j F k = 1 2 ∑ k = 1 j Q k a k + G · N - µ k R k - 1 2 + q ∑ k = 1 j ( a k T h k + 1 2 a k T S k a k ) -> min ( 27 ) As mentioned above, q is a scalar weighting factor (penalty parameter) which is equal to or greater than 0 (q≧0). We seek to minimize J in value in order to obtain ak, k=1, . . . , j and N. The minimization of scalar J essentially seeks to minimize the errors in the individual forms of ∥Hkμ·Ak−μk∥2 and conditions (11), if applicable, for data of all of the j epochs being considered, but with the constraint that floating ambiguity vector N in each individual state vector Ak be the same. The individual vectors ak are allowed to have different values. If the fixed distance constraint between rover and base stations is not considered to be present, then cost function Fk is omitted from equation (27), and all following equations based on equation (27). This may be simply done by setting weighting parameter q=0. If the fixed distance constraint is used, values for the weighting parameter q can range from approximately 0.5 to approximately 4, with a typical range being between approximately 1 and approximately 3. The best value of q often depends upon the amount of noise in the signals and the receivers, and can be found by trying several values within the above ranges (i.e., fine tuning). The inventors have found a value of q=2 to be useful for their test applications. In the case where the distance between the receivers is constrained to a fixed value, we emphasize that the use of the cost function qF is optional, and that one is not required to use it. Using the methods of the present invention without the cost function qF will still provide estimates of the floating ambiguities. The inclusion of the cost function qF generally enables more accurate estimates. The inventors have discovered that a set of N which minimizes scalar J can be found by solving the following block linear system for the set N, which is a vector. [ Q 1 T R 1 - 1 Q 1 + qS 1 O ⋯ O Q 1 T R 1 - 1 G O Q 2 T R 2 - 1 Q 2 + qS 2 ⋯ O Q 2 T R 2 - 1 G ⋮ ⋮ ⋰ ⋮ ⋮ O O ⋯ Q j T R j - 1 Q j + qS j Q j T R j - 1 G G T R 1 - 1 Q 1 G T R 2 - 1 Q 2 ⋯ G T R j - 1 Q j ∑ k = 1 j G T R k - 1 G ] [ a 1 a 2 ⋮ a j N ] = [ Q 1 T R 1 - 1 µ 1 - qh 1 Q 2 T R 2 - 1 µ 2 - qh 2 ⋮ Q j T R j - 1 µ j - qh j ∑ k = 1 j G T R k - 1 µ k ] ( 28 ) To the inventors' knowledge, the form of scalar J provide by equation (27) and form of the linear system provided by equation (28) are not found in the prior art. While it is preferred to use the weighting matrices R and their inverse matrices, it may be appreciated that the present invention can be practiced without them. In the latter case, each weighting matrix R may be replaced by an identity matrix of similar dimension in Equation (28) and the following equations; each inverse matrix R−1 is similarly replaced by an identity matrix. The inventors have further constructed an inverse matrix for the block matrix on the left-hand side of the equation (28), and from this inverse matrix have found a form of N which satisfies equation (28) as follows: N = [ ∑ k = 1 j ( G T R k - 1 G - G T R k - 1 Q k ( Q k T R k - 1 Q k + qS k ) - 1 Q k T R k - 1 G ) ] - 1 × [ ∑ k = 1 j ( G T R k - 1 µ k - G T R k - 1 Q k ( Q k T R k - 1 Q k + qS k ) - 1 ( Q k T R k - 1 µ k - qh k ) ) ] , ( 29 ) where this form comprises an n×n inverse matrix multiplying an n×1 vector. In the discussion that follows, we will identify the n×n inverse matrix as M−1 and the n×1 vector as B, with N=M−1 B. The above form may be more simply expressed if we form a matrix matrix Pk for the data of the k-th time moment in the following form: Pk=Rk−1−Ek−1Qk(QkTRk−1Qk+qSk)−1QkTRk−1 and a vector: gk=GTRk−1Qk(QkTRk−1Qk+qSk)−1hk With matrix Pk, equation (29) may now be written as: N = [ ∑ k = 1 j ( G T P k G ) ] - 1 × [ ∑ k = 1 j ( G T P k µ k + qg k ) ] ( 30 ) We refer to Pk as a projection-like matrix for q=0 and a quasi-projection matrix for q>0. Each component matrix G T P k G of M = [ ∑ k = 1 j ( G T P k G ) ] is symmetric positive definite and may be inverted. Moreover, a matrix comprised of a summation of symmetric positive definite matrices is also symmetric positive definite. Thus, matrix M is symmetric positive definite and can be inverted. In preferred implementations of the present invention, the inverse of M is not directly computed. Instead, a factorization of M into a lower triangular matrix L and an upper triangular matrix U is produced as follows: M=LU. Several different factorizations are possible, and L and U are not unique for a given matrix M. The LU factorization of matrix M enables us to compute the floating ambiguities N through a sequence of forward and reverse substitutions. These substitutions are well known to the art (cf any basic text on numerical analysis or matrix computations). With symmetric positive definite matrices, one may choose L and U such that U=LT, which gives a factorization of M=LLT. This is known as the Cholesky factorization, and it generally has low error due to numerical rounding than other factorizations. With N being generated from this form, the inventors have further found that each individual vector ak can be generated according to the following form: ak=(QkTRk−1Qk+qSk)−1(QkTRk−1(μk−GN)−qgk). (31) The generation of the individual vectors ak is optional to the process of generating a set of floating ambiguities N. However, when using cost function F(*) and equations (22) and (23), one can generate ak in order to update rk. The forms of N and ak which the inventors have discovered enable one to generate a vector N without having to first generate the individual vectors ak. When using the cost function F(*), Sk and hk (and gk which is derived from hk and Sk), an estimate of the baseline vector rk at time moment “k” has to be generated. As indicated by equations (22) and (23), both Sk and hk depend upon LRB, which does not normally change, and upon rk, which can change and often does change. For generating Sk and hk, it is usually sufficient to use an estimate of rk, which we denote at rk′ and which may be provided by the user or general process that is using the present invention. As part of generating the calculated distances DkR and DkB, the user or general process uses the estimated position of the rover and the known or estimated position of the base station. An estimate rk′ can be generated by subtracting the position of the base station from the estimated position of the rover. If desired, one can refine the estimate by generating ak from equation (31), and then using the combination (rk′+ak) as a more refined estimate of rk in generating Sk and hk. To do this, one may first generate an estimate N′ to N by using equation (30) with Sk=0 and gk=0. Then equation (31) can be evaluated using N=N′, Sk=0, and gk=0 to generate refined baseline vectors rk=(rk′+ak), and initial values of Sk′, hk′, and gk′. Equation (30) is then again evaluated using the initial values Sk′, hk′, and gk′ for Sk, hk, and gk, respectively. The process may be repeated again. To speed convergence, one can consider using prior values of Sk′ and gk′ in generating ak for k>1 as follows: ak=(QkTRk−1Qk+qSk-1)−1(QkTRk−1(μk−GN′)−qgk-1). First Exemplary Set of Method Implementations of the Present Invention The inventors have discovered a number of ways to employ the form of N provided by Equation (30). For post-processing application, the satellite data may be collected for a plurality j of time moments, the matrices Rk and Qk (and optionally Sk) and the vectors μk (and optionally hk and gk) for each k-th time moment may then be computed, and the n×n inverse matrix M−1 and the n×1 vector B may then be generated and thereafter multiplied together to generate the vector N. The plurality of time moments may be spaced apart from one another by equal amounts of time or by unequal amounts of time. As indicated above, instead of generating the inverse matrix M−1, one may generate the LU factorization of M and perform the forward and reverse substitutions. The factorization-substitution process is faster than generating the inverse matrix, and more numerically stable than most matrix inversion processes. If necessary, Equations (30) and (31) may be iterated as described above until convergence for significantly nonlinear dependency of quantities in equations (22) and (23) on the Rover position. For real-time applications, M−1 and B may be initially computed at a first time moment from a first set of data (e.g., R1, Q1, μ1, R2, Q2, μ2) and then recomputed at subsequent time moments when additional data becomes available. For instance, we can initially compute M and B based on l time moments k=1 to k=l as follows: M l = [ ∑ k = 1 l ( G T P k G ) ] ( 31 A ) B l = [ ∑ k = 1 l ( G T P k µ k + qg k ) ] , ( 31 B ) where the subscript “l” has been used with Ml and Bl to indicate that they are based on the l time moments k=1 to k=l. The floating ambiguity may then be computed from Nl=[Ml−1]·Bl, using matrix inversion or LU-factorization and substitution. Data from the next time moment l+1 can then be used to generate the updated quantities Ml+1 and Bl+1 as follows using the previously computed quantities Ml and Bl: Ml+1=Ml+GTPl+1G (31C) Bl+1=Bl+GTPl+1μl+1+qgl+1, (31D) With an updated set of floating ambiguities being computed from Nl+1=[Ml+1]−1 Bl+1, using matrix inversion or LU-factorization and substitution. It may be appreciated that the above forms of Ml+1 and Bl+1 may be employed recursively (e.g., iteratively) in time to compute updated floating ambiguities Nl+1 from previously-computed values of the quantities Ml and Bl as satellite data is collected. The recursion may be done with each recursive step adding data from one epoch, or with each recursive step adding data from multiple epochs, such as provided by the following forms: M m = M l + [ ∑ k = l + 1 k = m ( G T P k G ) ] ( 31 E ) B m = B l + [ ∑ k = l + 1 k = m ( G T P k µ k + qg k ) ] , ( 31 F ) where Ml and Bl are based upon j time moments, and Mm and Bm are based on these time moments plus the time moments l+1 through to m, where m>l+1. While these recursion methods are preferably applied to real-time applications, it may be appreciated that they may be equally used in post processing applications. Furthermore, while one typically arranges the time moments such that each time moment k+1 occurs after time moment k, it may be appreciated that other ordering of the data may be used, particularly for post processing applications. The steps of the above method are generally illustrated in a flow diagram 40 shown in FIG. 4. Initially, the data is received (e.g., γjB, γjR, DjB, DjR, φjB, φjR, Hjγ and optionally rj′ and LRB) as indicated at reference number 41. At step 42, the method generates, for each time moment j, a vector Δγj of a plurality of range residuals of pseudo-range measurements made by the first and second navigation receivers in the form of: Δγj=(γjR−γjB)−(DjR−DjB). At step 43, the method generates, for each time moment j, a vector Δφj of a plurality of phase residuals of full phase measurements made by the first and second navigation receivers in the form of: Δφj=(φjR−φjB)−Λ−1·(DjR−DjB), where Λ−1 is a diagonal matrix comprising the inverse wavelengths of the satellites, the set of phase residuals being denoted as Δφk, k=1, . . . , j. At step 44, the method generates an LU-factorization of a matrix M or a matrix inverse of matrix M, the matrix M being a function of at least Λ−1 and Hkγ, for index k of Hkγ covering at least two of the time moments j. Exemplary forms of matrix M have been provided above. At step 45, the method generates a vector N of estimated floating ambiguities as a function of at least the set of range residuals Δγk, the set of phase residuals Δφk, and the LU-factorization of matrix M or the matrix inverse of matrix M. Exemplary forms of vector N have been provided above. If the cost function F(*) is included, then steps 44 and 45 may be reiterated, along with a step of generating ak for refined estimates of rk, as indicated above. It may be appreciated that the above steps may be performed other sequences than that specifically illustrated in FIG. 4, as long as the data needed to perform a specific step is available. For example, parts of steps 41, 42, and 43 may be performed as matrix M is being assembled in step 44. The above method may be carried out on the exemplary apparatus 100 shown in FIG. 5. Apparatus 100 comprises a data processor 110, an instruction memory 112 and data memory 114 for data processor 110, an optional keyboard/display 115 for interfacing between data processor 110 and a human user, and a generalized data portal 120 for receiving the measured data r, γjB, γjR, DjB, DjR, φjB, φjR, Hjγ, and optionally rj′ and LRB, each data having been described in detail above. Memories 112 and 114 may be separate, or difference sections of the same memory bank. Generalized data portal 120 may take any number of conventional forms, such as one or more input/output ports, or one or more files stored on disk, tape, non-volatile memory, volatile memory, or other forms of computer readable medium. The data can be placed in data portal 120 by any number of means, such as by a user of the apparatus, or by a more general apparatus that utilizes the apparatus of the present invention in carrying out its functions (such as, for example, computing precise estimates of the position of the rover or the coordinates of the baseline vector). In the former case, the keyboard/display 115 may be used to receive information from the user as to when new data has been provided to data portal 120 (this may be useful in post-processing applications). In the latter case, a more general apparatus may comprise the rover station (including receiver channels such as that shown in FIG. 1) and radio transceiver for receiving data from the base station. In the case that both the base and rover stations are located on the same vessel, the more general apparatus may comprise the base and rover stations. Data processor 110 may be configured to implement the above-described method embodiments, such as exemplified by the steps in FIG. 4, by running under the direction of a computer product program present within instruction memory 112. An exemplary computer program product 60 is illustrated in FIG. 6. Computer program product 60 may be stored on any computer-readable medium and then loaded into instruction memory 112 as needed. Instruction memory 112 may comprises a non-volatile memory, a programmable ROM, and hard-wired ROM, or a volatile memory. Computer program produce 60 comprises five instruction sets. Instruction Set #1 directs data processor 110 to receive the measured data from data portal 120. The measured data from portal 120 may be loaded into data memory 114 by Instruction Set #1. As another implementation, the data may be loaded into memory 114 by subsequent instruction sets as the data is needed. In the latter case, Instruction Set #1 can take the form of a low-level I/O routine that is called by the other instruction sets as needed. As such, data portal 120 and data processor 110 under the direction of instruction set #1 provide means for receiving the measured data for apparatus 100. Instruction Set #2 directs data processor to generate, for each time moment j, a vector Δγj of a plurality of range residuals of pseudo-range measurements made by the first and second navigation receivers in the form of: Δγj=(γjR−γjB)−(DjR−DjB). As such, data processor 110 under the direction of instruction set #2 provides means for generating the range residuals Δγj for apparatus 100. Instruction Set #3 directs data processor 110 to generate, for each time moment j, a vector Δφj of a plurality of phase residuals of full phase measurements made by the first and second navigation receivers in the form of: Δφj=(φjR−φjB)−Λ−1·(DjR−DjB), where Λ−1 is a diagonal matrix comprising the inverse wavelengths of the satellites. As such, data processor 110 under the direction of instruction set #3 provides apparatus 100 with means for generating the phase residuals Δφj. The residuals may be stored in data memory 114. Instruction Set #4 directs data processor 110 to generate an LU-factorization of matrix M or a matrix inverse of matrix M, the matrix M being a function of at least Λ−1 and Hkγ, for index k of Hγ covering at least two of the time moments j. Exemplary forms of matrix M have been provided above. Matrix M and its LU-factorization or inverse may be stored in data memory 114. As such, data processor 110 under the direction of instruction set #4 provide apparatus 100 with means for generating matrix M and its LU-factorization or inverse. Finally, instruction Set #5 directs data processor 110 to generate a vector N of estimated floating ambiguities as a function of at least the set of range residuals Δγk, the set of phase residuals Δφk, and the LU-factorization of matrix M or the matrix inverse of matrix M. Exemplary forms of vector N have been provided above. Vector N may be stored in data memory 114. As such, data processor 110 under the direction of instruction set #5 provide apparatus 100 with means for generating an vector N, which is an estimate of the floating ambiguities. The resulting estimates provided by vector N may be outputted on keyboard/display 115, or may be provided to the more general process through data portal 120 or by other transfer means (such as by memory 114 if data processor 110 is also used to implement the more general process). Second Exemplary Set of Method Implementations of the Present Invention The inventors have developed additional recursive methods that are generally better suited to real-time applications. The second exemplary set of methods generally facilitate implementations which require less memory storage space and fewer computations. We previously defined a projection-like matrix Pk for the data of the k-th time moment as follows: Pk=Rk−1−Rk−1Qk(QkTRk−1Qk+qSk)−1QkTRk−1. (32) Equation (32) was then applied to the form of equation (30) to provide the form: N j = [ ∑ k = 1 j ( G T P k G ) ] - 1 [ ∑ k = 1 j ( G T P k µ k + qg k ) ] , ( 33 A ) where M and B are identified in the forms of: M j = [ ∑ k = 1 j ( G T P k G ) ] and B j = [ ∑ k = 1 j ( G T P k µ k + qg k ) ] . ( 33 B ) The forms of equations (33B) can be expressed in the following recursion form: Mj=Mj−1+GTPjG and Bj=Bj−1+GTPjμj+qgj (34) Then Nj=(Mj−1+GTPjG)−1(Bj−1+GTPjμj+qgj) (35A) noting that Nj=[Mj]−1 Bj for the data from time moments 1 through j, we can write Nj−1=[Mj−1]−1 Bj−1 for the data from time moments 1 through j−1. The latter can be rearranged as Mj−1 Nj−1=Bj−1 and used to substitute for the term Bj−1 in equation (35A) to provide: Nj=(Mj−1+GTPjG)−1(Mj−1Nj−1+GTPjμj+qgj) (35B) To equation (35B), we now add and subtract the term GT Pj G Nj−1 from the second bracketed quantity to obtain: Nj=(Mj−1+GTPjG)−1(Mj−1Nj−1+GTPjGNj−1−GTPjGNj−1+GTPjμj+qgj) (35C) Noting that the first two terms of the second bracketed quantity can be factored as (Mj−1+GTPjG) Nj−1 and that the factor (Mj−1+GTPjG) is the inverse of the first bracketed quantity in equation (35C), it can be seen that the first bracketed quantity multiplied onto (Mj−1+GTPjG) Nj−1 is simply Nj−1. Therefore, equation (35C) can be simplified as: Nj=Nj−1+(Mj−1+GTPjG)−1(−GTPjGNj−1+GTPjμj+qgj) (35D) The second bracketed quantity of equation (35D) can be further simplified as: Nj=Nj−1+(Mj−1+GTPjG)−1(GTPj(μj−GNj−1)+qgj) (35E) Using equation (34) this becomes: Nj=Nj−1+Mj−1(GTPj(μj−GNj−1)+qgj) (36) With this, the following recursive method may be used in a real time application: (1) Generate initial values of M0 and N0, set epoch counter k to zero (k=0). (2) Increment the epoch counter by one; obtain the data needed to generate the matrices Rk and Qk, and the vector μk. (3) Generate Rk and Qk, and μk. If the constant distance constraint is to be used, then also compute Sk, hk, and gk, and select a value for q greater than zero; otherwise, set qSk=0 and qgk=0 in steps (4)-(7) below. (4) Generate Pk in a form equivalent to: Pk=Rk−1−Rk−1Qk(QkTRk−1Qk+qSk)−1QTRk−1. (5A) Generate an LU-factorization of Mk, where Mk is in a form equivalent to Mk=Mk−1+GTPkG. Exemplary ways of generating LU factorizations are described in greater detail below. —OR— (5B) Generate an inverse matrix Mk−1 of Mk, where Mk is in a form equivalent to Mk=Mk−1+GTPkG. In general, this approach requires more computation than the approach of step (5A), and is currently the less preferred approach. (6) Generate Nk=Nk−1+Mk−1(GTPk(μk−GNk−1)+qgk). If the inverse matrix Mk−1 has been generated according to step (5B), this form may be generated by conventional multiplication of Mk−1 onto a vector Fk, where Fk=(GTPk(μk−GNk−1)+qgk). If the LU factorization for Mk has been generated according to step (5A), then the quantity χk=Mk−1(GTPk(μk−GNk−1)+qgk) may be generated from a forward and reverse substitution on the form: LkUkχk=Fk, where Lk is the lower triangular matrix and Uk is the upper triangular matrix of the factorization. The quantity χk is then added to Nk−1 to form Nk. (7) Optionally generate ak=(QkTRk−1Qk)−1(QkTRk−1(μk−GNk)−qgk) (8) Reiterate steps (2)-(7). For initial values it is convenient to use M0=0 and N0=0. One can also use satellite data from a single epoch to generate values for M0 and N0 using forms (4), (5A), (7A). This is in fact what is done with the above steps (2)-(6) are performed on the data for the first epoch with M0=0 and N0=0. In step (3), if the distance constraint is to be used, one may use rk′ to generate Sk, hk, and gk, or one may generate more refined estimate as (rk′+ak), with ak being generated as: ak=(QkTRk−1Qk)−1(QkTRk−1(μk−GNk−1)), or as ak=(QkTRk−1Qk+qSk−1)−1(QkTRk−1(μk−GNk−1)−qgk−1). During the first few recursion steps, matrix Mk may be ill-conditioned, and thus the generation of the LU factorization or inverse of Mk may incur some rounding errors. This problem can be mitigated by using Rk=I during the few recursions, or using an Rk with more equal weightings between the psuedorange and phase data, and then switching a desired form for Rk. The steps of the above method are generally illustrated in a flow diagram 70 shown in FIG. 7. Initially, the data is received (e.g., γjB, γjR, DjB, DjR, φjB, φjR, Hjγ and optionally rj′ and LRB) as indicated at reference number 71. At step 72, the method generates, for each time moment j, a vector Δγj of a plurality of range residuals of pseudo-range measurements made by the first and second navigation receivers in the form of: Δγj=(γjR−γjB)−(DjR−DjB). At step 73, the method generates, for each time moment j, a vector Δφj of a plurality of phase residuals of full phase measurements made by the first and second navigation receivers in the form of: Δφj=(φjR−φjB)−Λ−1·(DjR−DjB), where Λ−1 is a diagonal matrix comprising the inverse wavelengths of the satellites, the set of phase residuals being denoted as Δφk, k=1, . . . , j. At step 74, the method generates, for time moment j=1, an LU-factorization of a matrix M1 or a matrix inverse of matrix M1, the matrix M1 being a function of at least Λ−1 and Hlγ. Any of the forms for M described above may be used. At step 75, the method generates, for time moment j=1, a vector N1 as a function of at least Δγ1, Δφ1, and the LU-factorization of matrix M1 or the matrix inverse of matrix M1. At step 76, the method generates, for an additional time moment j≠1, an LU-factorization of a matrix Mj or a matrix inverse of matrix Mj, the matrix Mj being a function of at least Λ−1 and Hjγ. At step 77, the method generates, for an additional time moment j≠1, a vector Nj as a function of at least Δγj, Δφj, and the LU-factorization or matrix Mj or the matrix inverse of matrix Mj. At step 78, the estimated ambiguity vector Nj is reported. If the estimated ambiguity vector has not achieved sufficient accuracy, as set by the user, steps 76 and 77 are repeated, with steps 76-78 forming a loop. If the estimated ambiguity vector has achieved a sufficient degree of accuracy, or it steps 76-78 have been repeated for a maximum number of times set by the user, the process is ended. If the cost function F(*) is included, then step 76 may include the generation of ak for refined estimates of rk, as indicated above. It may be appreciated that the above steps may be performed other sequences than that specifically illustrated in FIG. 7, as long as the data needed to perform a specific step is available. For example, parts of steps 71-73 may be performed as matrix M1 is being assembled in step 74, and as matrix Mj is being assembled in step 76. It may also be appreciated that the data set provided to the process may span several tens of time moments to several thousands of time moments, and that the time moment j=1 illustrated above may correspond to any of the time moments in the data set, not just the earliest time moment or the first received time moment. It may also be appreciated that steps 74-75 may generated their respective M matrices and N vectors from data measured over two or more time moments as discussed above with regard to equations (31A)-(31F), as well as just one time moment, and that steps 76-77 may generated their respective M matrices and N vectors from data measured over two or more time moments as discussed above with regard to equations (31A)-(31F), as well as just one time moment. It may be further appreciated that approproate ones of the appended claims are intended to cover these possibilities. The above method embodiments may be carried out on the exemplary apparatus 100 shown in FIG. 5, using a different set of instructions in memory 112. Specifically, data processor 110 may be configured to implement the above-described method embodiments exemplified by the steps in FIG. 7, by running under the direction of a computer product program present within instruction memory 112. An exemplary computer program product 80 is illustrated in FIG. 8. Computer program product 80 may be stored on any computer-readable medium and then loaded into instruction memory 112 as needed. Instruction memory 112 may comprises a non-volatile memory, a programmable ROM, and hard-wired ROM, or a volatile memory. Computer program produce 80 comprises eight instruction sets. Instruction Set #1 directs data processor 110 to receive the measured data from data portal 120. The measured data from portal 120 may be loaded into data memory 114 by Instruction Set #1. As another implementation, the data may be loaded into memory 114 by subsequent instruction sets as the data is needed. In the latter case, Instruction Set #1 can take the form of a low-level I/O routine that is called by the other instruction sets as needed. As such, data portal 120 and data processor 110 under the direction of instruction set #1 provide means for receiving the measured data for apparatus 100. Instruction Set #2 directs data processor to generate, for each time moment j, a vector Δγj of a plurality of range residuals of pseudo-range measurements made by the first and second navigation receivers in the form of: Δγj=(γjR−γjB)−(DjR−DjB). As such, data processor 110 under the direction of instruction set #2 provides means for generating the range residuals Δγj for apparatus 100. Instruction Set #3 directs data processor 110 to generate, for each time moment j, a vector Δφj of a plurality of phase residuals of full phase measurements made by the first and second navigation receivers in the form of: Δφj=(φjR−φjB)−Λ−1·(DjR−DjB), where Λ−1 is a diagonal matrix comprising the inverse wavelengths of the satellites. As such, data processor 110 under the direction of instruction set #3 provides apparatus 100 with means for generating the phase residuals Δφj. The residuals may be stored in data memory 114. Instruction Set #4 directs data processor 110 to generate, for time moment j=1, an LU-factorization of a matrix M1 or a matrix inverse of matrix M1, the matrix M1 being a function of at least Λ−1 and H1 and H1γ. Exemplary forms of matrix M1 have been provided above. Matrix M1 and its LU-factorization or inverse may be stored in data memory 114. As such, data processor 110 under the direction of instruction set #4 provide apparatus 100 with means for generating matrix M1 and its LU-factorization or inverse. Instruction Set #5 directs the data processor 110 to generate, for time moment j=1, an estimated ambiguity vector N1 as a function of at least Δγ1, Δφ1, and the LU-factorization of matrix M1 or the matrix inverse of matrix M1. Exemplary forms of vector N1 have been provided above. Vector N1 may be stored in data memory 114. As such, data processor 110 under the direction of instruction set #5 provide apparatus 100 with means for generating an vector N1, which is an estimate of the floating ambiguities. Instruction Set #6 directs data processor 110 to generate, for one or more additional time moments j≠1, an LU-factorization of a matrix Mj or a matrix inverse of matrix Mj, the matrix Mj being a function of at least Λ−1 and Hjγ. Exemplary forms of matrix Mj have been provided above. Matrix Mj and its LU-factorization or inverse may be stored in data memory 114. As such, data processor 110 under the direction of instruction set #6 provide apparatus 100 with means for generating matrix Mj and its LU-factorization or inverse. Because of their similar operations, Instruction Set #6 may share or duplicate portions of Instruction Set #4. Instruction Set #7 directs the data processor 110 to generate, for one or more additional time moments j≠1, a vector Nj as a function of at least Δγj, Δφj, and the LU-factorization or matrix Mj or the matrix inverse of matrix Mj. Exemplary forms of vector Nj have been provided above. Vector Nj may be stored in data memory 114. As such, data processor 110 under the direction of instruction set #7 provide apparatus 100 with means for generating an vector Nj, which is an estimate of the floating ambiguities. Because of their similar operations, Instruction Set #7 may share or duplicate portions of Instruction Set #5. Instruction Set #8 directs the data processor 110 to report vector Nj as having estimates of the floating ambiguities, and to repeat Instruction Sets #6 and #7 if vector does not have sufficient (or desired) accuracy, or if it is desired to keep the process going even through sufficient accuracy has been reached. The resulting estimates provided by vector N may be outputted on keyboard/display 115, or may be provided to the more general process through data portal 120 or by other transfer means (such as by memory 114 if data processor 110 is also used to implement the more general process). Give the detailed description of the present Specification, it is well within the ability of one skilled in the GPS art to construct all of the above Instruction Sets without undue experimentation, and a detailed code listing thereof is not needed for one of ordinary skill in the art to make and use the present invention. Methods of LU-Factorization of Matrix M First Method. We now discuss methods of LU-factorization for matrix M. The factorization methods may be used in any of the above steps or computer instruction sets where an LU-factorization is generated or where an inverse matrix is generated, such as in step (5A) described above, and also used in step (5B) to construct an inverse matrix for M, although such is computationally costly. In one approach of LU-factorization, the matrix Mk−1 from the previous iteration is retained for the current iteration, and GT Pk G from the current iteration is added to it to form the matrix Mk for the current iteration of step (5B). Then, any LU-factorization method may be used to find a lower triangular matrix Lk and an upper triangular matrix Uk which satisfies Mk=Lk Uk. Since Mk is symmetric positive definite, the Cholesky method may be used. This method has good numerical stability, and generates upper triangular matrix Uk such that it equals the transpose of lower triangular matrix Lk: Uk=LkT. With this factorization, Mk=Lk LkT. The standard Cholesky method requires a square-root operation for each row of the matrix (n rows requires n square-root operations). Such operations may be difficult or time consuming to perform on mid-range processor chips. A modification of the Cholesky method developed by Wilkinson and Reinsch may be used to avoid these square-root operations. In this method, the factorization of Mk={tilde over (L)}D{tilde over (L)}T is used, where D is a diagonal matrix. We refer readers who are not familiar with this area of the art to the following references for further information: 1. Kendall E. Atkinson, An Introduction to Numerical Analysis, publisher: John Wiley & Sons, 1978, pages 450-454; 2. J. Wilkinson and C. Reinsch, Linear Algebra, Handbook for Automatic Computation, Vol. 2, publisher: Springer-Verlag, New York, 1971, pages 10-30; 3. Gene Golub and Charles Van Loan, Matrix Computations, publisher: The Johns Hopkins University Press, Baltimore, Md., pages 81-86. The above described main instruction sets that generate LU factorizations of matrix M can be constructed to include instructions that direct data processor 110 to carry out the above forms of Cholesky factorization of matrix M under this first method. The combination of these instructions and data processor 110 provides apparatus 100 with means for performing the Cholesky factorizations. Second Method. Instead of using the modified Cholesky method, the following method developed by the inventors may be used. The inventors currently prefer this method. Given that we have generated the previous factorization Mk−1=Lk−1Lk−1T, we generate a factorization TkTkT for the quantitiy GTPkG as follows: TkTkT=GTPkG. Later, we will describe how this factorization TkTkT may be generated. Using TkTkT=GTPkG, the factorization LkLkT of Mk may be written as: LkLkT=Lk−1Lk−1T+TkTkT. (37) It is known in the matrix computation art that the product of two n×n matrices X and Y is equal to the sum of the outer products of the columns of these matrices, as specified below: XY T = ∑ s = 1 n x s y s T , ( 38 ) where {x1, x2, . . . , xn} are the columns of matrix X, and where {y1, y2, . . . , yn} are the columns of matrix Y. The inventors have applied this general knowledge to their development of the invention to recognize that T k T k T = ∑ s = 1 n t k , s t k , s T , ( 39 ) where {tk,1, tk,2, . . . , tk,n} are the columns of matrix Tk. Each outer product tk,stk,sT is an n×n matrix of rank one. It is known from the article entitled “Methods for Modifying Matrix Factorizations” by P. E. Gill, G. H. Golub, W. Murray, and M. A. Saunders (Mathematics of Computation, Vol. 28, No. 126, April 1974, pp. 505-535) that when a rank-one matrix of the form z zT is added to a symmetric positive definite matrix A, a previously computed Cholesky factorization of matrix A may be modified with a relatively few number of computations (much less than the number of computations need to generate a factorization of A+zzT). The inventors have further recognized that performing n such rank-one modifications on the previous factorization Lk−1Lk−1T for Mk−1 using z zT=tk,stk,sT for s=1 to s=n would also require less computations and would have better accuracy that a new factorization for Mk. Let us illustrate this approach by first defining a set of intermediate factorization matrices {tilde over (L)}1, {tilde over (L)}2, . . . , {tilde over (L)}n, each of which has the same dimensions as Lk−1 and Lk. We now go through a sequence of n rank-one modifications which will sequentially generate the matrices {tilde over (L)}1 through {tilde over (L)}n, with the last matrix {tilde over (L)}n being in a form which is substantially equal to the desired factorization Lk. The first rank-one modification starts with any of the matrices tk,stk,sT. Without loss of generality, we will start with s=1 in order to simplify the presentation. We then write: {tilde over (L)}1{tilde over (L)}1T=Lk−1Lk−1T+tk,1tk,1T (40) which can be factored as: {tilde over (L)}1{tilde over (L)}1T=Lk−1(I+c1c1T)Lk−T, (41) where vectors c1 and tk,1 are related to one another as follows: Lk−1Tc1=tk,1. Vector c1 is readily obtained from vector tk,1 with a forward substitution process with the previously computed matrix Lk−1, since Lk−1, is lower triangular. Then, the above reference by Gill, et al. teaches how to readily obtain a Cholesky factorization of (I+c1c1T), which we denote here as {overscore (L)}1{overscore (L)}1T. The reader is referred to that reference, as well any other references teaching such factorizations, for the implementation details. From this it can be seen that the form of equation (35) becomes: {tilde over (L)}1{tilde over (L)}1T=Lk−1({overscore (L)}1{overscore (L)}1T)Lk−1T, (42) and thus {tilde over (L)}1=Lk−1{overscore (L)}1. The multiplication of two lower triangular matrices is relatively easy to perform and computationally inexpensive. We now perform the second rank-one modification using rank-one modification the matrix tk,2tk,2T (s=2) in a similar manner by writing: {tilde over (L)}2{tilde over (L)}2T={tilde over (L)}1{tilde over (L)}1T+tk,2tk,2T (43) which can be factored as: {tilde over (L)}2 {tilde over (L)}2T={tilde over (L)}1(I+c2c2T){tilde over (L)}1T, (44) where vector C2 is generated from tk,2 by forward substitution according to: {tilde over (L)}1c2=tk,2. A Cholesky factorization of (I+c2c2T) is then obtained, which we denote here as {overscore (L)}2{overscore (L)}2T. Thus, {tilde over (L)}2={tilde over (L)}1{overscore (L)}2. The recursion process continues in this manner until {tilde over (L)}n is computed. The following recursion sequence can be used: (1) Allocate matrices {tilde over (L)}0, {tilde over (L)}1, {tilde over (L)}2, . . . , {tilde over (L)}n, and {overscore (L)}1, {overscore (L)}2, . . . , {overscore (L)}n, and vectors c1, c2, . . . , cn. (2) Set an index j=1, and set {tilde over (L)}0=Lk−1. (3) Repeat the following steps (4)-(7) n times: (4) Generate vector cj from vector tk,j by forward substitution according to: {tilde over (L)}j−1cj=tk,j. (5) Generate matrix {overscore (L)}j as a Cholesky factorization of the quantity (I+cjcjT). (6) Generate matrix {tilde over (L)}j as the matrix multiplication of {tilde over (L)}j−1 and {overscore (L)}j: {tilde over (L)}j={tilde over (L)}j−1{overscore (L)}j. (7) Increment index j. (8) Provide {tilde over (L)} as Lk. Third Method. Close examination of the second method shows that the following more compact recursion sequence may be used: (1) Allocate matrices {tilde over (L)} and {overscore (L)} and a vectors c. (2) Set an index j=1, and set {tilde over (L)}=Lk−1. (3) Repeat the following steps (4)-(7) n times: (4) Generate vector c from tk,j by forward substitution according to: {tilde over (L)}cj=tk,j. (5) Generate matrix {overscore (L)} as a Cholesky factorization of the quantity (I+ccT). (6) Generate the matrix multiplication product {tilde over (L)}{overscore (L)}, and store the result as {tilde over (L)} (e.g., overwrite the storage location of {tilde over (L)} with the product {tilde over (L)}{overscore (L)}). (7) Increment index j. (8) Provide {tilde over (L)} as Lk. The above-described n sequential rank-one modifications require approximately half as many operations as direct re-factorization. In addition, low rank modifications to a matrix factorization are generally more numerically stable than direct re-factorization. The previously-described main instruction sets that generate LU factorizations of matrix M can be constructed to include instructions that direct data processor 110 to carry out the above forms steps of factorizing matrix M under the above second and third methods. Specifically, there would be a first subset of instructions that direct the data processor to generate an LU-factorization of matrix Mj−1 in a form equivalent to Lj−1 Lj−1T wherein Lj−1 is a low-triangular matrix and Lj−1T is the transpose of Lj−1. In addition, there would be a second subset of instructions that direct the data processor to generate a factorization of GT Pj G in a form equivalent to TjTjT=GTPjG, where TjT is the transpose of Tj (examplary methods for this are described below). There would also be a third subset of instructions that direct the data processor to generate an LU-factorization of matrix Mj in a form equivalent to Lj LjT from a plurality n of rank-one modifications of matrix Lj−1, as described above, each rank-one modification being based on a respective column of matrix Tj, where n is the number of rows in matrix Mj. The combination of these subsets of instructions and data processor 110 provides apparatus 100 with means for performing the above tasks. Generation of Matrix Tk The last two factorization methods requires finding TkTkT=GTPkG so that the column vectors tk,s may be used. One can use the Cholesky factorization method to generate Tk since GTPkG is symmetric positive definite (we call this the first method of generating matrix Tk). The above second subset of instructions be constructed to include further instructions that direct data processor 110 to carry out the any form of Cholesky factorization of GTPkG. to generate Tk. The combination of these further instructions and data processor 110 provides apparatus 100 with means for generate matrix Tj from a Cholesky factorization of GTPjG. However, the inventors have developed the following more efficient second method of generation of matrix Tk. It must be noted that this second method of generation of matrix Tk is applicable if the penalty parameter q related to the constant distance constraints defined by equation (11), and appearing starting with the Equation (27), is set to zero. In other words, the second method of generating matrix Tk described below is applicable if the constant distant constraints are not used. The Second Method of Generating Matrix Tk The second method is based on a novel block Householder transformation of the matrix GTPkG which the inventors have developed. This method is based on constraining the weighting matrices Rγ and Rφ to the following forms that are based on a common weighing matrix W: ( R γ ) - 1 = 1 σ γ 2 W , ( R φ ) - 1 = 1 σ φ 2 λ GPS 2 Λ W Λ , where σγ and σφ are scalar parameters selected by the user, and where λGPS2 is either the L1-band wavelength or the L2-band wavelength of the GPS system. If all the wavelengths in Λ are the same, the above forms reduce to: ( R γ ) - 1 = 1 σ γ 2 W , and ( R φ ) - 1 = 1 σ φ 2 W , With W, σγ, σφ, λGPS2, Rγ and Rφ selected, the following steps are employed to generate matrix Tk 1. Generate a scalar b in a form equivalent to: b = σ γ 2 λ GPS 2 σ γ 2 + λ GPS 2 σ φ 2 (in the case of dual band measurements b = σ γ 2 λ 1 2 λ 2 2 2 σ φ 2 λ 1 2 λ 2 2 + σ γ 2 λ 1 2 + σ γ 2 λ 2 2 2. Generate a matrix {tilde over (H)} in a form equivalent to {tilde over (H)}=W1/2Hk. 3. Generate a Householder matrix SHH for matrix {tilde over (H)}. 4. Generate matrix Tk in a form equivalent to: T k = 1 σ φ W 1 / 2 S HH [ ( 1 - b λ GPS 2 ) I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 I ( n - 4 ) × ( n - 4 ) ] or in the case of dual band measurements: T = 1 σ φ [ A11 O n × n A21 A22 ] , where sub-matrixces A11, A21, and A22 are as follows: A11 = ( W ( 1 ) ) 1 2 S HH [ 1 - b / λ 1 2 I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 I ( n - 4 ) ] , A21 = ( W ( 2 ) ) 1 2 S HH [ - b λ 1 λ 2 1 - b / λ 1 2 I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 O ( n - 4 ) × ( n - 4 ) ] , and A22 = ( W ( 2 ) ) 1 2 S HH [ 1 - b / λ 1 2 1 - b / λ 1 2 I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 I ( n - 4 ) ] . The derivation of this method is explained in Appendix A. The above second subset of instructions be constructed to include further instructions that direct data processor 110 to carry out the above four general step under this second method of generating matrix Tk. The combination of these further instructions and data processor 110 provides apparatus 100 with means for generate matrix Tj. While the present invention has been particularly described with respect to the illustrated embodiments, it will be appreciated that various alterations, modifications and adaptations may be made based on the present disclosure, and are intended to be within the scope of the present invention. While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the present invention is not limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims. APPENDIX A—Derivation of the Second Method of Generating Matrix T. To simplify the presentation of this derivation, we take the case of where the measurements are provided in only one GPS frequency band (e.g., L1-band). Generalization to two-band data and multiband data (GLONASS) is straight-forward matter. First, let us relate the range weighting matrix (Rγ)−1 and the phase weighting matrix (Rφ)−1 to a common weight matrix W and two scalar parameters σγ and σφ as follows: ( R γ ) - 1 = 1 σ γ 2 W , and ( R φ ) - 1 = 1 σ φ 2 W , where W is a diagonal positive definite n×n matrix. We now want to look at the block factorization of the component (QkTRk−1Qk)−1, which is part of Pk=Rk−1−Rk−1Qk(QkTRk−1Qk)−1QkTRk−1. To simplify the presentation, we are going to omit the time-moment subscript “k” and the pseudorange superscript “γ” from our notation for Q k = [ H k γ Λ - 1 H k γ ] , and simply use the notation Q = [ H Λ - 1 H ] in the following discussion . With the above , we can write the matrix component (QkTRk−1Qk)−1 as follows: ( Q T R - 1 Q ) - 1 = ( [ H T ❘ H T Λ - 1 ] [ 1 σ γ 2 W O n × n O n × n 1 σ φ 2 W ] [ H Λ - 1 H ] ) - 1 With the condition that the measurement data is within one signal band, all of the wavelengths are the same (for the purposes of determining the floating ambiguity), and the diagonal wavelength matrix Λ may be replaced by the identity matrix I multiplied by the scalar wavelength value λ: Λ=λI. This leads to the simplification: ( Q T R - 1 Q ) - 1 = ( 1 σ γ 2 + 1 λ 2 σ φ 2 ) - 1 ( H T WH ) - 1 = σ φ 2 σ γ 2 λ 2 σ γ 2 + λ 2 σ φ 2 ( H T WH ) - 1 . The quantity σ γ 2 λ 2 σ γ 2 + λ 2 σ φ 2 may be represented a single scalar value b ( b = σ γ 2 λ 2 σ γ 2 + λ 2 σ φ 2 ) , and the above may be further simplified as: (QTR−1Q)−1=σφ2b(HTWH)−1. The matrix W is diagonal positive definite so we can write W=W1/2W1/2. Then we have G T PG = 1 σ φ 2 W - 1 σ φ 2 W 1 λ H σ φ 2 b ( H T WH ) - 1 1 λ H T W 1 σ φ 2 = 1 σ φ 2 W 1 / 2 [ I n × n - b λ 2 W 1 / 2 H ( H T W 1 / 2 W 1 / 2 H ) - 1 H T W 1 / 2 ] W 1 / 2 . Denoting the matrix product W1/2H more simply as {tilde over (H)} (i.e., W1/2H={tilde over (H)}), the above form can be rewritten as: G T PG = 1 σ φ 2 W 1 / 2 [ I n × n - b λ 2 H ~ ( H ~ T H ~ ) - 1 H ~ T ] W 1 / 2 . We now generate reduced forms for {tilde over (H)} and {tilde over (H)}T. We apply the Householder transformation to matrix {tilde over (H)}T, which is indicated by Householder matrix SHH: {tilde over (H)}TSHH={tilde over (V)}=[V|O4×(n−4)], where matrix V is a lower diagonal 4×4 matrix. Matrix S is an n×n matrix, and is an orthogonal (so that SHHSHHT=In) since it is a Householder matrix. Multiplying both sides of the above equation by SHHT, and using the fact that SHHSHHT=In, we can find that: {tilde over (H)}T[V|O4×(n−4)]SHHT={tilde over (V)}SHHT. Then, by the transpose rule, we can find {tilde over (H)}=SHH{tilde over (V)}T. We now substitute these reduced forms for {tilde over (H)} and {tilde over (H)}T in the prior equation for GTPG, and perform the following sequence of substitutions, expansions, and regroupings: G T PG = 1 σ φ 2 W 1 / 2 [ S HH S HH T - b λ 2 S HH V ~ T ( VV T ) - 1 V ~ S HH T ] W 1 / 2 = 1 σ φ 2 W 1 / 2 S HH [ I n - b λ 2 V ~ T ( V T ) - 1 V - 1 V ~ ] S HH T W 1 / 2 = 1 σ φ 2 W 1 / 2 S HH [ I n - b λ 2 [ I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 O ( n - 4 ) × ( n - 4 ) ] ] S HH T W 1 / 2 = 1 σ φ 2 W 1 / 2 S HH [ [ I 4 - b λ 2 I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 I ( n - 4 ) × ( n - 4 ) ] ] S HH T W 1 / 2 . Finally, we obtain T = 1 σ φ W 1 / 2 S HH [ 1 - b λ 2 I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 I ( n - 4 ) × ( n - 4 ) ] . In the case when we use both GPS and GLONASS measurements, take matrices (Rγ)−1 and (Rφ)−1 in the form ( R γ ) - 1 = 1 σ γ 2 W , ( R φ ) - 1 = 1 σ φ 2 λ L1 2 Λ W Λ , where λ is the GPS wave length, then all the above reasoning hold including the formula for T. However the value b λ 2 close to 1 (but always less than 1), so 1 - b λ 2 is a small value, the operation of taking a square root does not reduce accuracy. This method of generating the matrix T may be extended to L1 and L2 band measurements. Let W ( 1 ) = 1 λ 1 2 Λ ( 1 ) W Λ ( 1 ) , W ( 2 ) = 1 λ 2 2 Λ ( 2 ) W Λ ( 2 ) , where λ1 and λ2 are the wavelengths of GPS L1 and L2 bands, respectively, and W is the weighing matrix, as above. Then ( R j γ ) - 1 = [ 1 σ γ 2 W O n × n O n × n 1 σ γ 2 W ] , ( R j φ ) - 1 = [ 1 σ φ 2 W ( 1 ) O n × n O n × n 1 σ φ 2 W ( 2 ) ] , and R - 1 = [ ( R γ ) - 1 O 2 n × 2 n O 2 n × 2 n ( R φ ) - 1 ] . Matrix Q thus takes the form Q = [ H H ( Λ ( 1 ) ) - 1 H ( Λ ( 2 ) ) - 1 H ] , so that ( Q T R - 1 Q ) = [ H T H T H T ( Λ ( 1 ) ) - 1 H T ( Λ ( 2 ) ) - 1 ] × [ 1 σ γ 2 W O n × n O n × n O n × n O n × n 1 σ γ 2 W O n × n O n × n O n × n O n × n 1 σ γ 2 W ( 1 ) O n × n O n × n O n × n O n × n 1 σ φ 2 W ( 2 ) ] · [ H H ( Λ ( 1 ) ) - 1 H ( Λ ( 2 ) ) - 1 H ] = ( 2 σ γ 2 + 1 σ φ 2 ( 1 λ 1 2 + 1 λ 2 2 ) ) H T WH , and ( Q T R - 1 Q ) - 1 = σ φ 2 σ γ 2 λ 1 2 λ 2 2 2 σ φ 2 λ 1 2 λ 2 2 + σ γ 2 λ 1 2 + σ γ 2 λ 2 2 ( H T WH ) - 1 , = σ φ 2 b ( H T WH ) - 1 where b is defined as b = σ γ 2 λ 1 2 λ 2 2 2 σ φ 2 λ 1 2 λ 2 2 + σ γ 2 λ 1 2 + σ γ 2 λ 2 2 . Note that in this case the matrix G takes the form G = [ O 2 n × 2 n I 2 n ] . G T PG = [ 1 σ φ 2 W ( 1 ) O n × n O n × n 1 σ φ 2 W ( 2 ) ] - [ 1 σ φ 2 W ( 1 ) O n × n O n × n 1 σ φ 2 W ( 2 ) ] [ ( Λ ( 1 ) ) - 1 H ( Λ ( 2 ) ) - 1 H ] σ φ 2 b ( H T WH ) - 1 × [ ( Λ ( 1 ) ) - 1 H T ( Λ ( 2 ) ) - 1 H T ] × [ 1 σ φ 2 W ( 1 ) O n × n O n × n 1 σ φ 2 W ( 2 ) ] = 1 σ φ 2 [ ( W ( 1 ) ) 1 2 O n × n O n × n ( W ( 2 ) ) 1 2 ] × ( I 2 n - b [ 1 λ 1 W 1 2 H 1 λ 2 W 1 2 H ] ( H T WH ) - 1 [ 1 λ 1 H T W 1 2 1 λ 2 H T W 1 2 ] ) [ ( W ( 1 ) ) 1 2 O n × n O n × n ( W ( 2 ) ) 1 2 ] As in the case of L1 measurements, denote W1/2H={tilde over (H)}, and, implementing Householder transformation: {tilde over (H)}TSHH={tilde over (V)}=[V|O4×(n−4)], that is H=SHH{tilde over (V)}T, {tilde over (H)}T={tilde over (V)}SHHT, we obtain: GPG T = 1 σ φ 2 [ ( W ( 1 ) ) 1 2 O n × n O n × n ( W ( 2 ) ) 1 2 ] × ( I 2 n - b [ 1 λ 1 S HH V ~ T 1 λ 2 S HH V ~ T ] ( VV T ) - 1 [ 1 λ 1 V ~ S HH T 1 λ 2 V ~ S HH T ] ) [ ( W ( 1 ) ) 1 2 O n × n O n × n ( W ( 2 ) ) 1 2 ] = 1 σ φ 2 [ ( W ( 1 ) ) 1 2 S HH O n × n O n × n ( W ( 2 ) ) 1 2 S HH ] × ( I 2 n - b [ 1 λ 1 I 4 O ( n - 4 ) × 4 1 λ 2 I 4 O ( n - 4 ) × 4 ] [ 1 λ 1 I 4 O 4 × ( n - 4 ) 1 λ 2 I 4 O 4 × ( n - 4 ) ] ) × [ S HH T ( W ( 1 ) ) 1 2 O n × n O n × n S HH T ( W ( 2 ) ) 1 2 ] = 1 σ φ 2 [ ( W ( 1 ) ) 1 2 S HH O n × n O n × n ( W ( 2 ) ) 1 2 S HH ] × K × [ S HH T ( W ( 1 ) ) 1 2 O n × n O n × n S HH T ( W ( 2 ) ) 1 2 ] . Matrix K has the following structure: K = [ ( 1 - b λ 1 2 ) I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 I ( n - 4 ) - b λ 1 λ 2 I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 O ( n - 4 ) × ( n - 4 ) - b λ 1 λ 2 I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 O ( n - 4 ) × ( n - 4 ) ( 1 - b λ 2 2 ) I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 I ( n - 4 ) ] . The Cholesky factorization of matrix K: K={tilde over (K)}{tilde over (K)}T may be obtained using finite formula: K ~ = [ 1 - b λ 1 2 I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 I ( n - 4 ) O n × n - b λ 1 λ 2 1 - b λ 1 2 I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 O ( n - 4 ) × ( n - 4 ) 1 - b λ 1 2 - b λ 2 2 1 - b λ 1 2 I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 I ( n - 4 ) ] . Thus, for matrix T, where GPGT=TTT, we may write T = 1 σ φ [ A11 O n × n A21 A22 ] , where sub-matrixces A11, A21, and A22 are as follows: A11 = ( W ( 1 ) ) 1 2 S HH [ 1 - b / λ 1 2 I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 I ( n - 4 ) ] , A21 = ( W ( 2 ) ) 1 2 S HH [ b λ 1 λ 2 1 - b / λ 1 2 I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 O ( n - 4 ) × ( n - 4 ) ] , and A22 = ( W ( 2 ) ) 1 2 S HH [ 1 - b / λ 1 2 - b / λ 2 2 1 - b / λ 1 2 I 4 O 4 × ( n - 4 ) O ( n - 4 ) × 4 I ( n - 4 ) ] . | <SOH> BACKGROUND OF THE INVENTION <EOH>Satellite navigation systems, such as GPS (USA) and GLONASS (Russia), are intended for high accuracy self-positioning of different users possessing special navigation receivers. A navigation receiver receives and processes radio signals broadcasted by satellites located within line-of-sight distance. The satellite signals comprise carrier signals that are modulated by pseudo-random binary codes, which are then used to measure the delay relative to local reference clock or oscillator. These measurements enable one to determine the so-called pseudo-ranges (γ) between the receiver and the satellites. The pseudo-ranges are different from true ranges (D, distances) between the receiver and the satellites due to variations in the time scales of the satellites and receiver and various noise sources. To produce these time scales, each satellite has its own on-board atomic clock, and the receiver has its own on-board clock, which usually comprises a quartz crystal. If the number of satellites is large enough (more than four), then the measured pseudo-ranges can be processed to determine the user location (e.g., X, Y, and Z coordinates) and to reconcile the variations in the time scales. Finding the user location by this process is often referred to as solving a navigational problem or task. The necessity to guarantee the solution of navigational tasks with accuracy better than 10 meters, and the desire to raise the stability and reliability of measurements, have led to the development of the mode of “differential navigation ranging,” also called “differential navigation” (DN). In the DN mode, the task of finding the user position is performed relative to a Base station (Base), the coordinates of which are known with the high accuracy and precision. The Base station has a navigation receiver that receives the signals of the satellites and processes them to generate measurements. The results of these measurements enable one to calculate corrections, which are then transmitted to the user that also uses a navigation receiver. By using these corrections, the user obtains the ability to compensate for the major part of the strongly correlated errors in the measured pseudo-ranges, and to substantially improve the accuracy of his or her positioning. Usually, the Base station is immobile during measurements. The user may be either immobile or mobile. We will call such a user “the Rover.” The location coordinates of a moving Rover are continuously changing, and should be referenced to a time scale. Depending on the navigational tasks to be solved, different modes of operation may be used in the DN mode. They differ in the way in which the measurement results are transmitted from the Base to the Rover. In the Post-processing (PP) mode, these results are transmitted as digital recordings and go to the user after all the measurements have been finished. In the PP mode, the user reconstructs his or her location for definite time moments in the past. Another mode is the Real-Time Processing (RTP) mode, and it provides for the positioning of the Rover receiver just during the measurements. The RTP mode uses a communication link (usually it is a radio communication link), through which all the necessary information is transmitted from the Base to the Rover receiver in digital form. Further improvement of accuracy of differential navigation may be reached by supplementing the measurements of the pseudoranges with the measurements of the phases of the satellite carrier signals. If one measures the carrier phase of the signal received from a satellite in the Base receiver and compares it with the carrier phase of the same satellite measured in the Rover receiver, one can obtain measurement accuracy to within several percent of the carrier's wavelength, i.e., to within several centimeters. The practical implementation of those advantages, which might be guaranteed by the measurement of the carrier phases, runs into the problem of there being ambiguities in the phase measurements. The ambiguities are caused by two factors. First, the difference of distances ΔD from any satellite to the Base and Rover is much greater than the carrier's wavelength λ. Therefore, the difference in the phase delays of a carrier signal Δφ=ΔD/λ received by the Base and Rover receivers exceeds several cycles. Second, it is not possible to measure the integer number of cycles in Δφ from the incoming satellite signals; one can only measure the fractional part of Δφ. Therefore, it is necessary to determine the integer part of Δφ, which is called the “ambiguity”. More precisely, we need to determine the set of all such integer parts for all the satellites being tracked, one integer part for each satellite. One has to determine this set along with other unknown values, which include the Rover's coordinates and the variations in the time scales. In a general way, the task of generating highly-accurate navigation measurements is formulated as follows: one determines the state vector of a system, with the vector containing n Σ unknown components. Those include three Rover coordinates (usually along Cartesian axes X, Y, Z) in a given coordinate system (sometimes time derivatives of coordinates are added too); the variations of the time scales which is caused by the phase drift of the local main reference oscillator; and n integer unknown values associated with the ambiguities of the phase measurements of the carrier frequencies. The value of n is determined by the number of different carrier signals being processed, and accordingly coincides with the number of satellite channels actively functioning in the receiver. At least one satellite channel is used for each satellite whose broadcast signals are being received and processed by the receiver. Some satellites broadcast more than one code-modulated carrier signal, such as a GPS satellite that broadcasts a carrier in the L 1 frequency band and a carrier in the L 2 frequency band. If the receiver processes the carrier signals in both of the L 1 and L 2 bands, the number of satellite channels (n) increases correspondingly. Two sets of navigation parameters are measured by the Base and Rover receivers, respectively, and are used to determine the unknown state vector. Each set of parameters includes the pseudo-range of each satellite to the receiver, and the full (complete) phase of each satellite carrier signal, the latter of which may contain ambiguities. Each pseudo-range is obtained by measuring the time delay of a code modulation signal of the corresponding satellite. The code modulation signal is tracked by a delay-lock loop (DLL) circuit in each satellite-tracking channel. The full phase of a satellite's carrier signal is tracked by phase counter (as described below) with input from a phase-lock-loop (PLL) in the corresponding satellite tracking channel (an example of which is described below in greater detail). An observation vector is generated as the collection of the measured navigation parameters for specific (definite) moments of time. The relationship between the state vector and the observation vector is defined by a well-known system of navigation equations. Given an observation vector, the system of equations may be solved to find the state vector if the number of equations equals or exceeds the number of unknowns in the state vector. In the latter case, conventional statistical methods are used to solve the system: the least-squares method, the method of dynamic Kalman filtering, and various modifications of these methods. Practical implementations of these methods in digital form may vary widely. In implementing or developing such a method on a processor, one usually must find a compromise between the accuracy of the results and speed of obtaining results for a given amount of processor capability, while not exceeding a certain amount of loading on the processor. The present invention is directed to novel methods and apparatuses for accelerating the obtaining of reliable estimates for the integer ambiguities at an acceptable processor load. More particularly, the present invention is directed to novel methods and apparatuses for more quickly obtaining such estimates in floating-point form (non-integer form) which are close to the integer values. With these floating-point forms, which we call floating ambiguities, conventional methods may be used to derive the corresponding integer ambiguities. | <SOH> SUMMARY OF THE INVENTION <EOH>Broadly stated, the present invention encompasses methods and apparatuses for estimating the floating ambiguities associated with the measurement of the carrier signals of a plurality of global positioning satellites, such that the floating ambiguities are preferably consist for a plurality of different time moments. The floating ambiguities are associated with a set of phase measurements of a plurality n of satellite carrier signals made by a first navigation receiver (B) and a second navigation receiver (R) separated by a distance, wherein a baseline vector (x o ,y o ,z o ) relates the position of the second receiver to the first receiver. Each satellite carrier signal is transmitted by a satellite and has a wavelength, and each receiver has a time clock for referencing its measurements. Any difference between the time clocks may be represented by an offset. Methods and apparatuses according to the present invention receive, for a plurality of two or more time moments j, the following inputs: a vector γ j B representative of a plurality of pseudo-ranges measured by the first navigation receiver (B) and corresponding to the plurality of satellite carrier signals, a vector γ j R representative of a plurality of pseudo-ranges measured by the second navigation receiver (R) and corresponding to the plurality of satellite carrier signals, a vector D j B representative of a plurality of estimated distances between the satellites and the first navigation receiver (B), a vector D J R representative of a plurality of estimated distances between the satellites and the second navigation receiver (R), a vector φ j B representative of a plurality of full phase measurements of the satellite carrier signals measured by the first navigation receiver (B), a vector φ j R representative of a plurality of full phase measurements of the satellite carrier signals measured by the second navigation receiver (R), and a geometric Jacobian matrix H j γ whose matrix elements are representative of the changes in the distances between the satellites and one of the receivers that would be caused by changes in that receiver's position and time clock offset. (As used herein, the term “representative of,” as used for example used when indicating that a first entity is representative of a second entity, includes cases where the first entity is equal to the second entity, where the first entity is proportional to the second entity, and where the first entity is otherwise related to the second entity.) The present invention may be practiced in real time, where estimates of the floating ambiguities are generated as the above satellite information is being received. The present invention may also be practiced in post-processing mode, where the floating ambiguities are estimated after all the above satellite information has been received. In the latter case, block processing according to the present invention may be done. Preferred methods and apparatuses according to the present invention generate, for each time moment j, a vector Δγ j of a plurality of range residuals of pseudo-range measurements made by the first and second navigation receivers in the form of: in-line-formulae description="In-line Formulae" end="lead"? Δγ j =(γ j R −γ j B )−( D j R −D j B ; in-line-formulae description="In-line Formulae" end="tail"? and also generate, for each time moment j, a vector Δφ j of a plurality of phase residuals of full phase measurements made by the first and second navigation receivers in the form of: Δφ j =(φ j R −φ j B )−Λ −1 ·(D j R −D j B ), where Λ −1 is a diagonal matrix comprising the inverse wavelengths of the satellites. In the case of real-time processing, an LU-factorization of a matrix M 1 , or a matrix inverse of matrix M 1 , is generated for a first time moment (denoted as j=1), with the matrix M 1 being a function of at least Λ −1 and H 1 γ . Also for this initial time moment, an initial vector N 1 of floating ambiguities is generated as a function of at least Δγ 1 , Δφ 1 , and the LU-factorization of matrix M 1 or the matrix inverse of matrix M 1 . For an additional time moment j, an LU-factorization of a matrix M j , or a matrix inverse of matrix M j , is generated, with the matrix M j being a function of at least Λ −1 and H j γ . Also for an additional time moment j, a vector N j of estimated floating ambiguities is generated as a function of at least Δγ j , Δφ j , and the LU-factorization or matrix M j or the matrix inverse of matrix M j . Exemplary forms of matrices M j and vectors N j are provided below. In this manner, a set of successively more accurate estimates of the floating ambiguities are generated in real-time with the vectors N j . This method, of course, may also be practiced in a post-processing environment, where the data has been previously recorded and then processed according to the above steps. In the post-processing environment, the following block processing approach according to the present invention may be practiced. As with above-described embodiments for real-time processing, the vectors of pseudo-range residuals Δγ k and vectors of phase residuals Δφ k , k=1, . . . j, are generated. Thereafter, a general matrix M is generated from the data, with M being a function of at least Λ −1 and H k γ , for index k of H k γ covering at least two of the time moments j, and an LU-factorization of matrix M or a matrix inverse of matrix M is generated. Thereafter, a vector N of estimated floating ambiguities is generated as a function of at least the set of range residuals Δγ k , the set of phase residuals Δφ k , and the LU-factorization of matrix M or the matrix inverse of matrix M. As an advantage of the present invention, the nature of matrix M, as described in greater detail below, enables a compact way of accumulating the measured data in order to resolve the floating ambiguities. As a further advantage, forms of matrix M provide a stable manner of factorizing the matrix using previous information. In preferred embodiments, matrix M is substantially positive definite, and also preferably symmetric. Accordingly, it is an objective of the present invention to improve the stability of generating estimates of the floating ambiguities, and a further objective to reduce the amount of computations required to generate estimates of the floating ambiguities. This and other advantages and objectives of the present invention will become apparent to those of ordinary skill in the art in view of the following description. | 20040226 | 20060905 | 20050901 | 93003.0 | 0 | ISSING, GREGORY C | METHODS AND APPARATUSES OF ESTIMATING THE POSITION OF A MOBILE USER IN A SYSTEM OF SATELLITE DIFFERENTIAL NAVIGATION | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,788,594 | ACCEPTED | Memory card host connector with retractable shieldless tab | The invention is directed to a memory card that includes a device connector conforming to the memory card standard, and a host connector conforming to a host connection standard and comprising a retractable shieldless tab compatible with the host connection standard. The presence of the two connectors adds versatility to the memory card. The host connector facilitates direct coupling of the memory card to a computing device without an adapter or reader. The memory card maintains a form factor of the memory card standard when the shieldless tab is retracted, which allows the memory card to be used similar to a conventional memory card of the memory card standard. In order to fit within the memory card standard form factor, the shieldless tab may be an altered version of a conventional connector interface conforming to the host connection standard. | 1. A memory card comprising: a memory card housing; a host connector housing formed in the memory card housing; a memory in the memory card housing; a device connector accessible through the memory card housing, the device connector conforming to a memory card standard and allowing access to the memory by a device compatible with the memory card standard; and a host connector comprising a shieldless tab extendable from the host connector housing, the host connector conforming to a host connection standard and allowing access to the memory upon insertion of the shieldless tab extended from the host connector housing into a host computer interface compatible with the host connection standard. 2. The memory card of claim 1, wherein the host connector conforms to one of a Universal Serial Bus (USB) standard and a Universal Serial Bus 2 (USB2) standard, and wherein the shieldless tab comprises a USB compatible tab without an electrical shield. 3. The memory card of claim 1, wherein the device connector conforms to a memory card standard selected from a group consisting of: a CompactFlash standard, a Smart Media standard, a MultiMedia Card standard, a Secure Digital standard, a Memory Stick standard, and an xD standard. 4. The memory card of claim 1, wherein the host connector comprises first electrical contacts disposed on the shieldless tab and coupled to second electrical contacts disposed within the host connector housing regardless of whether the shieldless tab is extended from the host connector housing or retracted into the host connector housing. 5. The memory card of claim 1, wherein the host connector slides within the host connector housing to extend the shieldless tab from the host connector housing for insertion of the shieldless tab into a host computer interface and to retract the shieldless tab into the host connector housing such that the memory card can be inserted into a device compatible with the memory card standard. 6. The memory card of claim 5, wherein the host connector housing provides access to a textured region disposed on the shieldless tab, the textured region providing traction such that pushing on the textured region causes the host connector to slide within the host connector housing. 7. The memory card of claim 1, wherein the device connector is disposed on a first side of the memory card housing and the host connector is disposed on a second side of the memory card housing adjacent to the first side. 8. The memory card of claim 1, wherein the host connector comprises a locking element that engages with a locking slot formed in the host connector housing to lock the shieldless tab in an extend position. 9. The memory card of claim 8, wherein the locking slot is a first locking slot and wherein the locking element engages with a second locking slot formed in the host connector housing to lock the shieldless tab in a retracted position. 10. The memory card of claim 8, wherein the locking element prevents the host connector from completely disengaging from the host connector housing. 11. The memory card of claim 8, further comprising spring loaded electrical contacts disposed within the host connector housing that provide a mechanical bias to the host connecter such that the host connector is depressed against the electrical contacts and slid within the host connector housing to extend the shieldless tab from the host connector housing and retract the shieldless tab into the host connector housing and the locking element is biased against the host connector housing to ensure engagement with the locking slot when the shieldless tab is extended. 12. The memory card of claim 1, further comprising spring loaded electrical contacts disposed within the host connector housing that provide a mechanical bias to the host connector such that the host connector is depressed against the mechanical bias and slid within the host connector housing to extend the shieldless tab from the host connector housing and retract the shieldless tab into the host connector housing. 13. A memory card comprising: a memory card housing having dimensions which substantially conform to a form factor of a memory card standard including a height of approximately 36 mm and a width of approximately 42 mm; a host connector housing formed in the memory card housing; a memory in the memory card housing; a device connector accessible through the memory card housing, the device connector conforming to the memory card standard and allowing access to the memory by a device compatible with the memory card standard; and a host connector comprising a shieldless tab extendable from the host connector housing, the host connector conforming to a host connection standard and allowing access to the memory upon insertion of the shieldless tab extended from the host connector housing into a host computer interface compatible with the host connection standard. 14. The memory card of claim 13, wherein the device connector conforms to a CompactFlash type I memory card standard and wherein the memory card housing conforms to the CompactFlash type I memory card form factor including a thickness of approximately 3.3 mm. 15. The memory card of claim 13, wherein the device connector conforms to a CompactFlash type II memory card standard and wherein the memory card housing conforms to the CompactFlash type II memory card form factor including a thickness of approximately 5 mm. 16. The memory card of claim 13, wherein the memory card standard form factor includes a thickness, which is less than a thickness of the shieldless tab including an electrical shield. 17. A memory card comprising: a memory card housing; a host connector housing formed in the memory card housing; a memory in the memory card housing; a device connector accessible through a first side of the memory card housing, the device connector conforming to a memory card standard and allowing access to the memory by a device compatible with the memory card standard; a host connector disposed on a second side of the memory card housing adjacent the first side and comprising a shieldless tab extendable from the host connector housing, first electrical contacts disposed on the shieldless tab, and a locking element, the host connector conforming to a host connection standard and allowing access to the memory upon insertion of the shieldless tab extended from the host connector housing into a host computer interface compatible with the host connection standard; second electrical contacts disposed within the host connector housing and coupled to the first electrical contacts disposed on the shieldless tab regardless of whether the shieldless tab is extended from the host connector housing or retracted into the host connector housing, the second electrical contacts are spring loaded to provide a mechanical bias to the host connector such that the host connector is depressed against the second electrical contacts in order to slide the host connector within the host connector housing to extend the shieldless tab from the host connector housing and retract the shieldless tab into the host connector housing; and a locking slot formed in the host connector housing, wherein the second electrical contacts bias the locking element of the host connector against the host connector housing such that the locking element engages with the locking slot when the shieldless tab is extended from the host connector housing to lock the shieldless tab in an extended position. 18. The memory card of claim 17, wherein the locking slot is a first locking slot, the memory card further comprising a second locking slot formed in the host connector housing, wherein the locking element engages with the second locking slot when the shieldless tab is retracted into the host connector housing to lock the shieldless tab in a retracted position. 19. The memory card of claim 17, wherein the host connector conforms to one of a Universal Serial Bus (USB) standard and a Universal Serial Bus 2 (USB2) standard, and wherein the shieldless tab comprises a USB compatible tab without an electrical shield. 20. The memory card of claim 17, wherein the device connector conforms to a memory card standard selected from a group consisting of: a CompactFlash standard, a Smart Media standard, a MultiMedia Card standard, a Secure Digital standard, a Memory Stick standard, and an xD standard. | TECHNICAL FIELD The invention relates to removable storage media devices and, in particular, removable memory cards with host connectors. BACKGROUND A wide variety of removable storage media exists for use with voice recorders, digital video camcorders, digital cameras, personal digital assistants (PDAs), cellular phones, video games, digital televisions, photo printers, and the like. The removable storage media allows users to capture and store data on such devices, and easily transport the data between these various devices and a computer. One of the most popular types of removable storage media is the flash memory card, which is compact, easy to use, and has no moving parts. A flash memory card includes an internal, high-speed solid-state memory capable of persistently storing data without application of power. Numerous other memory standards can also be used in memory cards, including electrically-erasable-programmable-read-only-memory (EEPROM), non-volatile random-access-memory (NVRAM), and other non-volatile or volatile memory types, such as synchronous dynamic random-access-memory (SDRAM), with battery backup. A wide variety of memory cards have been recently introduced, each having different capacities, access speeds, formats, interfaces, and connectors. Examples of memory cards include CompactFlash™ (CF) first introduced by SanDisk™ Corporation, the Memory Stick™ (MS) and subsequent versions including Memory Stick Pro and Memory Stick Duo developed by Sony Corporation, Smart Media™ memory cards, Secure Digital (SD) memory cards, and MultiMedia Cards (MMCs) jointly developed by SanDisk Corporation and Siemens AG/Infineon Technologies AG, and xD™ digital memory cards developed by Fuji. Each of the different memory cards typically conforms to a specific form factor of the standard and includes a unique connector which conforms the electrical and mechanical interfaces of the card to the respective standard. Moreover, each different memory card generally requires a specialized adapter or reader for use with a computing device. The adapter or reader includes a specialized interface that conforms to that of the memory card, and a host interface that can be accepted by a computer. For example, an adaptor or reader may include an interface to receive a memory card and an interface to connect to a host computer, such as a personal computer memory card international association (PCMCIA) interface including a 16 bit standard PC Card interface and a 32 bit standard CardBus interface, a Universal Serial Bus (USB) interface, a Universal Serial Bus 2 (USB2) interface, a future generation USB standard, an IEEE 1394 FireWire interface, a Small Computer System Interface (SCSI) interface, an Advance Technology Attachment (ATA) interface, a serial ATA interface, an Integrated Device Electronic (IDE) standard, an Enhanced Integrated Device Electronic (EIDE) standard, a Peripheral Component Interconnect (PCI) interface, a PCI Express interface, a conventional serial or parallel interface, or the like. Conventional memory cards have only one connector to interface with a device. The same connector also interfaces with the adaptor or reader to allow the memory card to be read by a host computer. Most conventional adapters and readers support only a single type of memory card, causing a user to carry and interchange adapters or readers when using different types of memory cards. SUMMARY In general, the invention is directed to a memory card that includes a device connector conforming to a memory card standard, and a host connector conforming to a host connection standard. The host connector comprises a retractable shieldless tab compatible with the host connection standard. The presence of the two connectors adds versatility to the memory card. The device connector facilitates direct coupling of the memory card to a portable device such as a voice recorder, a digital video camcorder, a digital camera, a personal digital assistant (PDA), a cellular phone, a video game, a digital television, a photo printer, or the like. The host connector facilitates direct coupling of the memory card to a computing device without need for an adapter or reader. Additionally, the memory card maintains a form factor of the memory card standard when the shieldless tab is retracted, which allows the memory card to be inserted into portable devices the same way a conventional memory card would be used. In order to conform the memory card form factor to that of a given standard, the shieldless tab may be an altered version of a conventional host connector interface. For example, the host connector may conform to a Universal Serial Bus (USB) standard or a Universal Serial Bus 2 (USB2) standard, and the shieldless tab may comprise a USB compatible tab without an electrical shield. The elimination of the shield substantially reduces the thickness of the host connector on the memory card and ensures that the host connector does not define a thickness larger than the memory card. In one embodiment, the invention is directed to a memory card comprising a memory card housing, a host connector housing formed in the memory card housing, a memory in the memory card housing, a device connector, and a host connector. The device connector is accessible through the memory card housing, conforms to the memory card standard, and allows access to the memory by a device compatible with the memory card standard. The host connector comprises a shieldless tab extendable from the host connector housing. The host connector conforms to a host connection standard and allows access to the memory upon insertion of the shieldless tab extended from the host connector housing into a host computer interface compatible with the host connection standard. In another embodiment, the invention is directed to a memory card comprising a memory card housing, a host connector housing formed in the memory card housing, a memory in the memory card housing, a device connector, and a host connector. The memory card housing has dimensions which substantially conform to a form factor of a memory card standard including a height of approximately 36 mm and a width of approximately 42 mm. The device connector is accessible through the memory card housing, conforms to the memory card standard, and allows access to the memory by a device compatible with the memory card standard. The host connector comprises a shieldless tab extendable from the host connector housing. The host connector conforms to a host connection standard and allows access to the memory upon insertion of the shieldless tab extended from the host connector housing into a host computer interface compatible with the host connection standard. The thickness of the shieldless tab is less than the thickness of the memory card, which may also conform to the thickness defined by the memory card standard. For example, the thickness of the shieldless tab may be approximately 2.0 mm while the thickness of the card is between approximately 3.3 mm and 5 mm. A thickness of the shieldless tab including an electrical shield may be approximately 4.5 mm, which may be larger than a thickness of the memory card standard form factor. For this reason, elimination of the shield is needed in order to create a memory card that includes the host connector which does not add thickness to the card which would otherwise undermine insertion of the card into a device. In another embodiment, the invention is directed to a memory card comprising a memory card housing, a host connector housing formed in the memory card housing, a memory in the memory card housing, a device connector, a host connector, electrical contacts disposed within the host connector housing, and a locking slot formed in the host connector housing. The device connector is accessible through a first side of the memory card housing, conforms to the memory card standard, and allows access to the memory by a device compatible with the memory card standard. The host connector is disposed on a second side of the memory card housing adjacent the first side and comprises a shieldless tab extendable from the host connector housing, electrical contacts disposed on the shieldless tab, and a locking element. The host connector conforms to a host connection standard and allows access to the memory upon insertion of the shieldless tab extended from the host connector housing into a host computer interface compatible with the host connection standard. The electrical contacts disposed within the host connector housing are coupled to the electrical contacts disposed on the shieldless tab regardless of whether the shieldless tab is extended from the host connector housing or retracted into the host connector housing. Moreover, the electrical contacts disposed within the host connector housing may be spring loaded to provide a constant mechanical bias between the electrical contacts disposed within the host connector housing and the electrical contacts on the shieldless tab. In that case, the electrical contacts in the host connector housing bias the locking element of the host connector against the memory card housing such that the locking element engages with the locking slot when the shieldless tab is extended from the host connector housing. Another locking slot may lock the shieldless tab in a retracted position. A user may depress the host connector against the mechanical bias of the electrical contacts within the host connector housing in order to release the locking element from either locking slot. The invention is capable of providing many advantages. For example, the host connector provides direct access to the memory card from a computing device without the need for an adapter or reader conforming to the memory card standard. Additionally, the shieldless tab is sized such that it may be retracted into the memory card without altering the form factor of the memory card. Therefore, the memory card is compatible with devices that are compatible with conventional memory cards of the memory card standard. The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF DRAWINGS FIGS. 1 and 2 are schematic diagrams illustrating a memory card according to an embodiment of the invention. FIGS. 3 and 4 are conceptual top views illustrating an exemplary embodiment of a memory card, which is substantially similar to the memory card from FIGS. 1 and 2. FIGS. 5 and 6 are conceptual side views illustrating an exemplary embodiment of a host connector held in a host connector housing. FIG. 7 is a conceptual exploded view illustrating a host connector and a host connector housing. FIG. 8 is a block diagram illustrating an exemplary architecture of a removable memory card according to an embodiment of the invention. FIG. 9 is a block diagram illustrating an exemplary architecture of a removable memory card. FIG. 10 is a block diagram illustrating an exemplary architecture of a removable memory card. FIG. 11 is a block diagram illustrating an exemplary architecture of a removable memory card. DETAILED DESCRIPTION FIGS. 1 and 2 are schematic diagrams illustrating a memory card 10 according to an embodiment of the invention. Memory card 10 includes a memory card housing 12, a host connector housing 18 formed in memory card housing 12, a device connector 14, and a host connector 16. Device connector 14 conforms to a memory card standard of memory card 10 and facilitates access to an internal memory of memory card 10 by a device compatible with the memory card standard. Host connector 16 conforms to a host connection standard and comprises a shieldless tab 20 compatible with the host connection standard and extendable from host connector housing 18. Host connector 16 facilitates direct coupling of memory card 10 to a host computer via insertion of shieldless tab 20 extended from host connector housing 18 into a host computer interface. Shieldless tab 20 can also retract into host connector housing 18 such that memory card housing 12 substantially conforms to a form factor of the memory card standard. This allows memory card 10 to remain compatible with memory card slots in conventional portable devices that interface with device connector 14. FIG. 1 shows shieldless tab 20 retracted into host connector housing 18, while FIG. 2 shows shieldless tab 20 extended from host connector housing 18. In the embodiment shown in FIGS. 1 and 2, device connector 14 conforms to a CompactFlash standard and host connector 16 conforms to either a USB standard, a USB2 standard, or a future generation USB standard. In that case, shieldless tab 20 comprises a USB compatible tab without an electrical shield. A form factor of the CompactFlash standard includes a height of approximately 36 mm, a width of approximately 42 mm, and a thickness between approximately 3.3 mm and 5 mm. A conventional USB plug includes a tab surrounded by an electrical shield and is coupled to a cable. The USB compatible tab may have a thickness of approximately 2.0 mm while the conventional USB plug including the electrical shield may have a thickness of approximately 4.5 mm, which may be larger than the memory card standard form factor. In the case of the conventional USB plug, the electrical shield is necessary to reduce or eliminate electrostatic effects that may corrupt the signal carried by the attached cable. The invention described herein does not require the use of a cable to transmit data signals, because shieldless tab 20 may be directly coupled to both an internal memory of memory card 10 and a host computer interface. Therefore an electrical shield around shieldless tab 20 can be eliminated. Furthermore the elimination of the electrical shield enables shieldless tab 20 to fit within memory card housing 12 conforming to a form factor of a memory card standard of memory card 10. In other embodiments, device connector 14 may conform to a Smart Media standard, a MultiMedia Card standard, a Secure Digital standard, a Memory Stick standard and subsequent versions including Memory Stick Pro and Memory Stick Duo, an xD standard, a yet released standard, or the like. Host connector 16 may conform to a variety of standards as long as a compatible shieldless tab can be formed to fit within memory card housing 12. Examples of host connection standards include a personal computer memory card international association (PCMCIA) standard including a 16 bit standard PC Card interface and a 32 bit standard CardBus interface, a USB standard, a USB2 standard, a future generation USB standard, an IEEE 1394 FireWire standard, a Small Computer System Interface (SCSI) standard, an Advance Technology Attachment (ATA) standard, a serial ATA standard, an Integrated Device Electronic (IDE) standard, an Enhanced Integrated Device Electronic (EIDE) standard, a Peripheral Component Interconnect (PCI) standard, a PCI Express standard, a conventional serial or parallel interface standard, or the like. The standards described herein refer to such standards as defined on the filing date of this patent application. In an exemplary embodiment, device connector 14 and host connector 16 may be disposed on adjacent sides of memory card housing 12, as shown in FIGS. 1 and 2. This arrangement reduces the possibility of device connector contacts being touched or handled by a user when shieldless tab 20 is inserted into a host connector interface of a host computing device. For example, excessive handing of the device connector contacts may damage the memory card by subjecting the components within memory card housing 12 to electrostatic effects, dust, and debris. Of course, device connector 14 and host connector 16 could be disposed on opposing sides in other embodiments. Device connector 14 and host connector 16 are electrically coupled to a memory disposed within memory card housing 12 via electrical contacts (not shown). For example, first electrical contacts may be disposed on shieldless tab 20 and second electrical contacts may be disposed within host connector housing 18, as described in more detail below. In one embodiment, the electric contacts of shieldless tab 20 and host connector housing 18 are continually coupled to each other regardless of the position of shieldless tab 20. In another embodiment, the electrical contacts are coupled to each other only when shieldless tab 20 is extended from host connector housing 18. A mechanical bias may be applied to host connector 16 such that a user must depress host connector 16 against the mechanical bias in order to slide host connector 16 within the host connector housing to extend shieldless tab 20 from host connector housing 18 or retract shieldless tab 20 into host connector housing 18. Host connector 16 may also include a locking system to lock shieldless tab 20 in an extended position and/or a retracted position. The mechanical bias and the locking system may be used together such that a user must depress host connector 16 to disengage the locking system. By locking shieldless tab 20 into the extended position, shieldless tab 20 can be ensured to meet the force required for insertion into a host computer interface. The locking system may also restrain host connector 16 from completely disengaging from host connector housing 18. Embodiments of the invention which include the mechanical bias and the locking system will be described in more detail below. FIGS. 3 and 4 are conceptual top views illustrating an exemplary embodiment of a memory card 40, which is substantially similar to memory card 10 from FIGS. 1 and 2. Memory card 40 includes a memory card housing 42 that defines a host connector housing 48 and conforms to a form factor of the memory card standard with a height (H) and a width (W). The memory card standard may be a CompactFlash standard, which includes a form factor with a height of approximately 36 mm and a width of approximately 42 mm. Additionally, memory card 40 includes a device connector 44 and a host connector 46 held within host connector housing 48. Host connector 46 comprises a shieldless tab 50 extendable from host connector housing 48, a textured region 54 disposed on shieldless tab 50, and a host connector housing cover 56 adjacent shieldless tab 50. With shieldless tab 50 retracted into host connector housing 48, as shown in FIG. 3, memory card 40 may operate substantially similar to a conventional memory card of the same standard. In other words, memory card 40 is able to couple, via device connector 44 conforming to the memory card standard, to any device compatible with the memory card standard without affecting the size and operation of the device. For example, memory card 40 may fit into a compatible memory card receptacle in conventional voice recorders, digital video camcorders, digital cameras, personal digital assistants (PDAs), cellular phones, video games, digital televisions, photo printers, and the like. Host connector 46 conforms to a host connection standard and, with shieldless tab 50 extended from host connector housing 48 as shown in FIG. 4, allows direct coupling of memory card 40 to a host computer interface compatible with the host connection standard. Accordingly, memory card 40 substantially eliminates the need for a memory card adapter or reader to retrieve data stored in a memory within memory card housing 42. Shieldless tab 50 may comprise an altered version of a conventional connector interface conforming to the host connection standard in order to fit within memory card housing 42 without affecting the form factor of the memory card standard. Regardless, shieldless tab 50 maintains compatibility with the host connection standard. The elimination of the shield greatly reduces a thickness of the host connector, which allows shieldless tab 50 to fit within memory card housing 42. Furthermore, the invention reduces the benefits that would otherwise be provided by an electrical shield because shieldless tab 50 directly couples to the memory within memory card housing 42 and to a host computer interface without a cable. Conventionally, the electrical shield is used to reduce electrostatic effects that may corrupt the data signal carried by the cable. For this reason, eliminating the cable makes the electrical shield less important. Shieldless tab 50 is electrically coupled to the memory within memory card housing 42 via electrical contacts disposed on shieldless tab 50 and within host connector housing 48. When inserted into a compatible host computer interface, shieldless tab 50 electrically couples the computing device to the memory. As shown in FIGS. 3 and 4, host connector housing 48 provides access to host connector 46 including textured region 54 disposed on shieldless tab 50 to allow host connector 46 to be slid within host connector housing 48 to retract and extend shieldless tab 50 by pushing on textured region 54. For example, a user may push on textured region 54 to slide host connector 46 forward to extend shieldless tab 50 from host connector housing 48. Once shieldless tab 50 is extended from host connector housing 48, host connector housing cover 56 protects any components disposed within host connector housing 48 from exposure to electrostatic effects, dust, and debris. In the embodiment including a mechanical bias and a locking system, the user may need to press down on textured region 54 to disengage the locking system and slide host connector 46 within host connector housing 48. In other embodiments, host connector 46 does not necessarily include a textured region or a host connector housing cover. FIGS. 5 and 6 are conceptual side views illustrating an exemplary embodiment of host connector 46 held in host connector housing 48. Again, host connector 46 comprises shieldless tab 50 and host connector housing cover 56 adjacent to shieldless tab 50. Additionally host connector 46 includes a locking element 60. Host connector housing 48 includes a locking slot 62 and electrical contacts 64. Host connector housing 48 comprises a thickness (T), which is substantially equal to a thickness of memory card housing 42 of memory card 40 conforming to the memory card standard form factor. The memory card standard may be a CompactFlash type I standard, which includes a form factor with a thickness of approximately 3.3 mm. The memory card standard may also be a CompactFlash type II standard, which includes a form factor with a thickness of approximately 5 mm. A thickness of shieldless tab 50 is less than the thickness (T) of host connector housing 48 and memory card housing 42. For example, a USB compatible tab comprises a thickness of approximately 2.0 mm. Furthermore, a conventional USB plug including an electrical shield comprises a thickness of approximately 4.5 mm, which is larger than the CompactFlash type I standard form factor. For this reason, the invention contemplates the elimination of the conventional USB shield so that the host connector comprising a shieldless tab defines a thickness less than that of the memory card. Host connector 46 may also include electrical contacts disposed on shieldless tab 50 that couple to electrical contacts 64 within host connector housing 48. In that way, shieldless tab 50 may be electrically coupled to a memory within memory card housing 42. In the embodiment shown in FIGS. 5 and 6, electric contacts 64 run along the entire length of host connector housing 48 such that the electrical contacts may be continually coupled to each other regardless of the position of shieldless tab 50. In another embodiment, electrical contacts 64 may be placed within host connector housing 48 such that the electrical contacts couple to each other only when shieldless tab 50 is extended from host connector housing 48. As shown in FIGS. 5 and 6, electrical contacts 64 are spring loaded by a curvature in the contacts to provide a mechanical bias to host connector 46. When shieldless tab 50 is retracted into host connector housing 48, as shown in FIG. 5, electrical contacts 64 bias shieldless tab 50 against host connector housing 48 such that shieldless tab 50 is held in a retracted position and a user must depress shieldless tab 50 against electrical contacts 64 to extend shieldless tab 50. For example, a user may press down on textured region 54, from FIGS. 3 and 4, to remove shieldless tab 50 from the pressure of the mechanical bias. The user may then push forward on textured region 54 to slide host connector 46 within host connector housing 48 to extend shieldless tab 50 from host connector housing 48. When shieldless tab 50 is extended from host connector housing 48, as shown in FIG. 6, locking element 60 of host connector 46 engages with locking slot 62 formed in host connector housing 48 to lock shieldless tab 50 in an extended position. In other embodiments, host connector housing 48 may include another locking slot to lock shieldless tab 50 in a retracted position. The mechanical bias applied to host connector 46 forces locking element 60 against host connector housing 48 such that once shieldless tab 50 is fully extended from host connector housing 48, locking element 60 will automatically engage with locking slot 62. In particular, by locking shieldless tab 50 into the extended position, shieldless tab 50 can be ensured to withstand the force required for insertion into a host computer interface without being accidentally retracted. Locking element 60 may also restrain host connector 46 from completely disengaging from host connector housing 48. In order to retract shieldless tab 50 into host connector housing 48, a user again must depress shieldless tab 50 against electrical contacts 64 to disengage locking element 60 from locking slot 62 and slide host connector 46 within host connector housing 48. FIG. 7 is a conceptual exploded view illustrating host connector 46 and host connector housing 48. Host connector 46 includes shieldless tab 50, textured region 54 disposed on shieldless tab 50, host connector housing cover 56 adjacent shieldless tab 50, and locking element 60. In addition, host connector 46 comprises electrical contacts 66 disposed on shieldless tab 50. Host connector housing 48 includes locking slot 62 and electrical contacts 64. When host connector 46 is inserted into host connector housing 48, electrical contacts 66 will continually couple to electrical contacts 64, disposed within host connector housing 48, regardless of the position of shieldless tab 50 by sliding along electrical contacts 64 as host connector 46 slides within host connector housing 48. Electrical contacts 64 and 66 electrically couple shieldless tab 50 to a memory within memory card housing 42. Locking element 60 includes a contour that ensures host connector 46 cannot fully disengage from host connector housing 48 once inserted. The contoured locking element 60 cannot be pushed out of locking slot 62 without disassembling host connector housing 48. Eliminating the possibility of removing host connector 46 from host connector housing 48, ensures electrical contacts 64 and 66 remain accurately coupled to each other to maintain a quality connection between shieldless tab 50 and the memory within memory card 40. Electrical contacts 64 include a curvature that spring loads the electrical contacts 64 to create the mechanical bias that controls the movement of host connector 46 when inserted into host connector housing 48. The curvature is placed along electrical contacts 64 such that the bias against host connector 46 forces locking element 60 into locking slot 62. In an embodiment including a second locking slot formed in host connector housing 48 to lock shieldless tab 50 in a retracted position, a different curvature may be defined to ensure engagement of both locking elements into the respective locking slots. FIG. 8 is a block diagram illustrating an exemplary architecture of a removable memory card 70, which may correspond to any of memory cards 10 or 40. Memory card 70 includes a memory 72, a device connector 74, a device connector controller 75, a memory controller 76, a host connector controller 77, and a host connector 78. Device connector 74 conforms to the memory card standard and allows access to memory 72 by a device compatible with the memory card standard. Host connector 78 conforms to a host connection standard and allows access to memory 72 upon insertion into a host computer interface compatible with the host connection standard. Device connector 74 may be electrically coupled to memory 72 via device connector controller 75 and memory controller 76. Host connector 78 may be electrically coupled to memory 72 via host connector controller 77 and memory controller 76. By way of example, memory 72 may comprise one or more elements of flash memory, electrically-erasable-programmable-read-only-memory (EEPROM), non-volatile random-access-memory (NVRAM), and other nonvolatile or volatile memory types, such as synchronous dynamic random-access-memory (SDRAM), or the like. Memory 72 may include a plurality of such memory elements in order to support large memory capacity. Power is applied to memory card 70 when it is connected via the memory card standard to a portable device or via the host connection standard to a computing device. The application of power allows the portable device or computing device to determine which electrical contact elements are active. Accordingly, the portable device or computing device can determine which connector 74, 78 is being used based on which electrical contact elements are active. Device connector controller 75 or host connector controller 77 is enabled to facilitate access to memory 72, depending on which connector 74, 78 is being used. Communication between the portable device or computing device and memory controller 76 may then be sent through the powered connector and the enabled controller. The portable device or computing device may read or modify data that is stored in memory 72 as well as store new data or erase existing data. Memory controller 76 manipulates the data stored in memory 72 according to operations specified by the portable device or computing device. Device connector 74 may couple to a portable device interface conforming to the same memory card standard and operate in a similar manner to a conventional memory card of the memory card standard. Host connector 78 may couple directly to a host computer interface conforming to the same host connection standard and enable communication between the computing device and memory controller 76. The invention eliminates the need for an adapter or reader to couple memory card 70 to the computing device by including an adapter's function in the memory card. FIG. 9 is a block diagram illustrating another exemplary architecture of a removable memory card 80, which may correspond to any of memory cards 10 or 40. Memory card 80 includes a memory 82, a device connector 84, a memory and device connector controller 86, a host connector controller 87, and a host connector 88. Memory 82, device connector 84, and host connector 88 may operate substantially similar to memory 72, device connector 74 and host connector 78, respectively, from FIG. 8. Whereas the architecture shown in FIG. 8 utilizes three separate controllers, i.e., one for each connector 74, 78 and one for the memory 72, the embodiment of FIG. 9 integrates the memory controller with the controller for device connector 84 as a common memory and device connector controller 86. Such an integrated controller 86 may consume less space and power than separate controllers. Moreover, controllers that integrate the memory and device connector controls are commercially available for use in conventional memory cards that include a memory and a single connector. Controller 86 controls memory 82 and output via device connector 84. The host connector controller 87 controls memory 82 and output via host connector 88. Device connector 84 may be electrically coupled directly to controller 86 and then to memory 82, while host connector 88 may be electrically coupled to memory 82 via host connector controller 87. In one embodiment of the invention, memory card 80 includes device connector 84 conforming to a Compact Flash standard and host connector 88 conforming to an USB standard. Memory card 80 also includes controller 86 conforming to a flash memory controller, memory 82 conforming to a flash memory, and host connector controller 87 conforming to a USB controller. These components are readily available due to their wide usage in traditional removable memory cards and adapters or readers. Flash memory controllers are manufactured by SanDisk™ Corporation and Lexar Media Inc., among others. Flash memory is produced by many companies including Intel, Samsung, and Toshiba. USB controllers are typically found in flash memory card adaptors or readers and other devices utilizing USB connectivity. Such controllers are available from Cypress Semiconductor Corporation, Philips Semiconductors, and many other semiconductor companies. In this embodiment, substantially all the elements included in memory card 80 are already being produced for other purposes and may be purchased directly from the manufacturer. FIG. 10 is a block diagram illustrating another exemplary architecture of a removable memory card 90, which may correspond to any of memory cards 10 or 40. Memory card 90 includes a memory 92, a device connector 94, a memory and device connector controller 96, a memory and host connector controller 97, and a host connector 98. Memory 92, device connector 94, and host connector 98 may operate substantially similar to memory 72, device connector 74 and host connector 78, respectively, from FIG. 8. Whereas the architecture shown in FIG. 8 utilizes three separate controllers, i.e., one for each connector 74, 78 and one for the memory 72, the embodiment of FIG. 10, integrates memory control into the controller for device connector 94 as a common memory and device connector controller 96, substantially similar to memory and device connector controller 86 from FIG. 9. Memory control is also integrated into the controller for host connector 98 as a common memory and host connector controller 97. Such integrated controllers 96, 97 may consume less space and power than three separate controllers. Moreover, controllers that integrate the memory and device connector controls are commercially available for use in conventional memory cards that include a memory and a single device connector. Additionally, controllers that integrate the memory and host connector controls are also commercially available for use in conventional portable memory drives that include a memory and a single host connector. Memory and device controller 96 controls memory 92 and output via device connector 94. Memory and host controller 97 also controls memory 92 and output via host connector 98. Device connector 94 may be electrically coupled to memory 92 via memory and device controller 96. Host connector 98 may be electrically coupled to memory 92 via memory and host controller 97. In one embodiment of the invention, memory card 90 includes device connector 94 conforming to a CompactFlash standard and host connector 98 conforming to an USB standard. Memory card 90 also includes memory and device controller 96 conforming to a flash memory card controller, memory 92 conforming to a flash memory, and memory and host controller 97 conforming to a flash memory drive controller. These components are readily available due to their wide usage in traditional removable memory cards and traditional removable memory drives. In this embodiment, all the elements included in memory card 90 are already being produced for other purposes and may be purchased directly from the manufacturer. FIG. 11 is a block diagram illustrating another exemplary architecture of a removable memory card 100, which may correspond to any of memory cards 10 or 40. In this embodiment, memory card 100 includes a memory 102, a device connector 104, a controller 106, and a host connector 108. Memory 102, device connector 104, and host connector 108 may operate substantially similar to memory 72, device connector 74 and host connector 78, respectively, from FIG. 8. Controller 106 comprises a memory controller integrated with a device connector controller and a host connector controller. Whereas the architecture shown in FIG. 8 utilizes a separate controller for each connector 74, 78 and the memory 72, controller 106 integrates such functionality of three different controllers into a common unit. By integrating the functionality of each separate controller into controller 106, less space and power may be consumed on memory card 100. Controller 106 controls the memory 102 and output via device connector 104 and host connector 108. Device connector 104 may be electrically coupled directly to controller 106 and then to memory 102. Host connector 108 may also be electrically coupled to memory 102 via controller 106. In one embodiment, memory card 100 includes device connector 104 conforming to a CompactFlash standard and host connector 108 conforming to an USB standard. Memory card 100 also includes controller 106 conforming to a flash memory controller with USB control and memory 102 conforming to a flash memory. Device connector 104 may couple to a portable device contact conforming to the CompactFlash standard. Host connector 108 may couple directly to a computing device's USB port allowing communication between the computing device and controller 106 without an adaptor or reader. The flash memory controller with USB control may be developed as an application specific integrated circuit (ASIC) integrating the functionality of a conventional flash memory controller and a USB controller. Various embodiments of the invention have been described. For example, a memory card has been described that includes both a device connector and a host connector. The memory card operates as a conventional memory card when a shieldless tab of the host connector is retracted into the memory card and eliminates the need for an adapter or reader when the shieldless tab is extended from the memory card. Further the shieldless tab is altered from a conventional connection interface to fit within a form factor of the memory card standard. A mechanical bias and a locking system have also been described that control movement of the host connector and positioning of the shieldless tab. Nevertheless, various modifications may be made without departing from the scope of the invention. For example, a variety of locking systems may be applied to the invention as long as the shieldless tab is able to withstand the force required for insertion to a host computer interface. The locking systems may include movable parts or a plurality of locking positions. Moreover, the mechanical bias may be provided to the host connector by a means other than spring loaded electrical contacts or no mechanical bias may be provided. Finally, the memory card may conform to a variety of memory card standards and host connection standards such that a form factor different from the embodiments described herein may be used. In particular, the shieldless tab may comprise a variety of forms as long as compatibility with the host connection standard conformed to by the host connector is maintained. These and other embodiments are within the scope of the following claims. | <SOH> BACKGROUND <EOH>A wide variety of removable storage media exists for use with voice recorders, digital video camcorders, digital cameras, personal digital assistants (PDAs), cellular phones, video games, digital televisions, photo printers, and the like. The removable storage media allows users to capture and store data on such devices, and easily transport the data between these various devices and a computer. One of the most popular types of removable storage media is the flash memory card, which is compact, easy to use, and has no moving parts. A flash memory card includes an internal, high-speed solid-state memory capable of persistently storing data without application of power. Numerous other memory standards can also be used in memory cards, including electrically-erasable-programmable-read-only-memory (EEPROM), non-volatile random-access-memory (NVRAM), and other non-volatile or volatile memory types, such as synchronous dynamic random-access-memory (SDRAM), with battery backup. A wide variety of memory cards have been recently introduced, each having different capacities, access speeds, formats, interfaces, and connectors. Examples of memory cards include CompactFlash™ (CF) first introduced by SanDisk™ Corporation, the Memory Stick™ (MS) and subsequent versions including Memory Stick Pro and Memory Stick Duo developed by Sony Corporation, Smart Media™ memory cards, Secure Digital (SD) memory cards, and MultiMedia Cards (MMCs) jointly developed by SanDisk Corporation and Siemens AG/Infineon Technologies AG, and xD™ digital memory cards developed by Fuji. Each of the different memory cards typically conforms to a specific form factor of the standard and includes a unique connector which conforms the electrical and mechanical interfaces of the card to the respective standard. Moreover, each different memory card generally requires a specialized adapter or reader for use with a computing device. The adapter or reader includes a specialized interface that conforms to that of the memory card, and a host interface that can be accepted by a computer. For example, an adaptor or reader may include an interface to receive a memory card and an interface to connect to a host computer, such as a personal computer memory card international association (PCMCIA) interface including a 16 bit standard PC Card interface and a 32 bit standard CardBus interface, a Universal Serial Bus (USB) interface, a Universal Serial Bus 2 (USB2) interface, a future generation USB standard, an IEEE 1394 FireWire interface, a Small Computer System Interface (SCSI) interface, an Advance Technology Attachment (ATA) interface, a serial ATA interface, an Integrated Device Electronic (IDE) standard, an Enhanced Integrated Device Electronic (EIDE) standard, a Peripheral Component Interconnect (PCI) interface, a PCI Express interface, a conventional serial or parallel interface, or the like. Conventional memory cards have only one connector to interface with a device. The same connector also interfaces with the adaptor or reader to allow the memory card to be read by a host computer. Most conventional adapters and readers support only a single type of memory card, causing a user to carry and interchange adapters or readers when using different types of memory cards. | <SOH> SUMMARY <EOH>In general, the invention is directed to a memory card that includes a device connector conforming to a memory card standard, and a host connector conforming to a host connection standard. The host connector comprises a retractable shieldless tab compatible with the host connection standard. The presence of the two connectors adds versatility to the memory card. The device connector facilitates direct coupling of the memory card to a portable device such as a voice recorder, a digital video camcorder, a digital camera, a personal digital assistant (PDA), a cellular phone, a video game, a digital television, a photo printer, or the like. The host connector facilitates direct coupling of the memory card to a computing device without need for an adapter or reader. Additionally, the memory card maintains a form factor of the memory card standard when the shieldless tab is retracted, which allows the memory card to be inserted into portable devices the same way a conventional memory card would be used. In order to conform the memory card form factor to that of a given standard, the shieldless tab may be an altered version of a conventional host connector interface. For example, the host connector may conform to a Universal Serial Bus (USB) standard or a Universal Serial Bus 2 (USB2) standard, and the shieldless tab may comprise a USB compatible tab without an electrical shield. The elimination of the shield substantially reduces the thickness of the host connector on the memory card and ensures that the host connector does not define a thickness larger than the memory card. In one embodiment, the invention is directed to a memory card comprising a memory card housing, a host connector housing formed in the memory card housing, a memory in the memory card housing, a device connector, and a host connector. The device connector is accessible through the memory card housing, conforms to the memory card standard, and allows access to the memory by a device compatible with the memory card standard. The host connector comprises a shieldless tab extendable from the host connector housing. The host connector conforms to a host connection standard and allows access to the memory upon insertion of the shieldless tab extended from the host connector housing into a host computer interface compatible with the host connection standard. In another embodiment, the invention is directed to a memory card comprising a memory card housing, a host connector housing formed in the memory card housing, a memory in the memory card housing, a device connector, and a host connector. The memory card housing has dimensions which substantially conform to a form factor of a memory card standard including a height of approximately 36 mm and a width of approximately 42 mm. The device connector is accessible through the memory card housing, conforms to the memory card standard, and allows access to the memory by a device compatible with the memory card standard. The host connector comprises a shieldless tab extendable from the host connector housing. The host connector conforms to a host connection standard and allows access to the memory upon insertion of the shieldless tab extended from the host connector housing into a host computer interface compatible with the host connection standard. The thickness of the shieldless tab is less than the thickness of the memory card, which may also conform to the thickness defined by the memory card standard. For example, the thickness of the shieldless tab may be approximately 2.0 mm while the thickness of the card is between approximately 3.3 mm and 5 mm. A thickness of the shieldless tab including an electrical shield may be approximately 4.5 mm, which may be larger than a thickness of the memory card standard form factor. For this reason, elimination of the shield is needed in order to create a memory card that includes the host connector which does not add thickness to the card which would otherwise undermine insertion of the card into a device. In another embodiment, the invention is directed to a memory card comprising a memory card housing, a host connector housing formed in the memory card housing, a memory in the memory card housing, a device connector, a host connector, electrical contacts disposed within the host connector housing, and a locking slot formed in the host connector housing. The device connector is accessible through a first side of the memory card housing, conforms to the memory card standard, and allows access to the memory by a device compatible with the memory card standard. The host connector is disposed on a second side of the memory card housing adjacent the first side and comprises a shieldless tab extendable from the host connector housing, electrical contacts disposed on the shieldless tab, and a locking element. The host connector conforms to a host connection standard and allows access to the memory upon insertion of the shieldless tab extended from the host connector housing into a host computer interface compatible with the host connection standard. The electrical contacts disposed within the host connector housing are coupled to the electrical contacts disposed on the shieldless tab regardless of whether the shieldless tab is extended from the host connector housing or retracted into the host connector housing. Moreover, the electrical contacts disposed within the host connector housing may be spring loaded to provide a constant mechanical bias between the electrical contacts disposed within the host connector housing and the electrical contacts on the shieldless tab. In that case, the electrical contacts in the host connector housing bias the locking element of the host connector against the memory card housing such that the locking element engages with the locking slot when the shieldless tab is extended from the host connector housing. Another locking slot may lock the shieldless tab in a retracted position. A user may depress the host connector against the mechanical bias of the electrical contacts within the host connector housing in order to release the locking element from either locking slot. The invention is capable of providing many advantages. For example, the host connector provides direct access to the memory card from a computing device without the need for an adapter or reader conforming to the memory card standard. Additionally, the shieldless tab is sized such that it may be retracted into the memory card without altering the form factor of the memory card. Therefore, the memory card is compatible with devices that are compatible with conventional memory cards of the memory card standard. The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. | 20040227 | 20061219 | 20050915 | 99346.0 | 1 | BUI, HUNG S | MEMORY CARD HOST CONNECTOR WITH RETRACTABLE SHIELDLESS TAB | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,788,848 | ACCEPTED | Method and apparatus for solid fuel pulverizing operation and maintenance optimization | A system for use with a roll bowl type mill for the pulverizing of solid fuels such as coal. The system includes hardware in the form of sensors and other components and software to among other things monitor the operating condition of the mill's moving parts and predict their failure. The system can determine the diameter of the mill's rollers, or the reduction and/or depth of cup wear of each of the rollers, the thickness of the solid fuel in the mill, can by analysis determine the wear of each of the one or more roller bearings in the mill and predict their failure and can estimate the mill availability | 1. In combination: a roll-bowl type mill for pulverizing solid fuels for use in firing a steam generator, said pulverizing mill comprising: a) a bowl having a predetermined diameter; b) one or more rollers each connected to an assembly through an associated roller bearing, said assembly for holding each of said one or more rollers and for applying a preload on each of said one or more rollers, each of said one or more rollers located a predetermined distance above said bowl; and c) one or more linear transducers mounted on said assembly to measure the displacement of the movement of said assembly when said mill is operating; a data acquisition system having as an input said assembly movement displacement measured by said one or more linear transducers comprising: a computing device for data collection and frequency power spectrum analysis of said assembly shaft displacement to determine: a) the diameter, D, of each of said one or more rollers by using the formula: D=Fb/FrDb b) where, Fb is the bowl frequency and Fr is the roller frequency determined by power spectrum analysis respectively, and Db is said bowl predetermined diameter. 2. The combination of claim 1 wherein said computing device further determines the reduction and/or depth of wear cup, H, of each of said one or more rollers by using the formula: D 1 = 2 R 1 = F b F r 1 D b D 2 = 2 R 2 = F b F r 2 D b H = R 1 - R 2 = | F r 2 - F r 1 | F b D b 2 F r 1 F r 2 where, Fr1 is the dominant roller frequency peak from power spectrum analysis Fr2 is the secondary roller frequency peak from power spectrum analysis. 3. The combination of claim 2 wherein said computing device further determines the relative thickness if said solid fuel in said mill by using the formula: L 1 = β | L | - | L 0 | | L 0 | , where L is the value of the displacement of said journal spring shaft measured by said one or more linear transducers, L0 is the calibrated value from said one or more transducers, and β is a coefficient. 4. The combination of claim 1 wherein said mill further comprises a wall and a means having one or more vibration sensors mounted thereon for connecting said assembly onto said mill wall and said computing device determines wear of each of said one or more roller bearings by analyzing using vibration pattern signature and/or order analysis methods the signal from each of said one or more vibration sensors. 5. The combination of claim 4 wherein said connecting means is a trunion shaft. 6. The combination of claim 4 wherein said connecting means is said assembly. 7. In combination: a roll-bowl type mill for pulverizing solid fuels for use in firing a steam generator, said pulverizing mill comprising: a) a bowl having a predetermined diameter; b) one or more rollers each connected to an assembly through an associated roller bearing, said assembly for holding each of said one or more rollers and for applying a preload on each of said one or more rollers, said one or more rollers located a predetermined distance above said bowl; and c) one or more linear transducers mounted on said assembly to measure the displacement of the movement of said assembly when said mill is operating; a data acquisition system having as an input said assembly movement displacement measured by said one or more linear transducers comprising: a computing device for data collection and frequency power spectrum analysis of said assembly shaft displacement to determine the reduction and/or depth of wear cup, H, of each of said one or more rollers by using the formula: D 1 = 2 R 1 = F b F r 1 D b D 2 = 2 R 2 = F b F r 2 D b H = R 1 - R 2 = | F r 2 - F r 1 | F b D b 2 F r 1 F r 2 where, Fr1 is the dominant roller frequency peak from power spectrum analysis Fr2 is the secondary roller frequency peak from power spectrum analysis. 8. In combination: a roll-bowl type mill for pulverizing solid fuels for use in firing a steam generator, said pulverizing mill comprising: a) a bowl having a predetermined diameter; b) one or more rollers each connected to an assembly through an associated roller bearing, said assembly for holding each of said one or more rollers and for applying a preload on each of said one or more rollers, said one or more rollers located a predetermined distance above said bowl; and c) one or more linear transducers mounted on said assembly to measure the displacement of the movement of said assembly when said mill is operating; a data acquisition system having as an input said assembly movement displacement measured by said one or more linear transducers comprising: a computing device for data collection and frequency power spectrum analysis of said assembly shaft displacement to determine the relative thickness of said solid fuel in said mill by using the formula: L 1 = β | L | - | L 0 | | L 0 | , where L is the value of the displacement of said journal spring shaft measured by said one or more linear transducers, L0 is the calibrated value from said one or more transducers, and β is a coefficient. 9. A system comprising: a mill for pulverizing solid fuels for use in firing a steam generator, said mill comprising a predetermined number of components used in pulverizing said solid fuel; and a processing device for determining an indicator P, where 0≦P≦1, for presenting the availability of said mill to perform said solid fuel pulverizing by using the formula: P = ∑ 1 n w i p i where wi is the weight factor, Σwi=1; and c) is the availability of each individual component of said predetermined number of components and 0≦pi≦1. 10. An apparatus for use with a mill for pulverizing solid fuels for use in firing a steam generator, said mill comprising a predetermined number of components used in pulverizing said solid fuel, said apparatus comprising: a computing device for determining an indicator P, where 0≦P≦1, for presenting the availability of said mill to perform said solid fuel pulverizing by using the formula: P = ∑ 1 n w i p i where wi is the weight factor, Σwi=1; and pi is the availability of each individual component of predetermined number of components and 0≦pi≦1. 11. A computer readable medium having instructions for causing a computer to execute a method comprising: determining an indicator P, where 0≦P≦1, for presenting the availability of a mill for pulverizing solid fuels for use in firing a steam generator, said mill comprising a predetermined number of components used in pulverizing said solid fuel, to perform said solid fuel pulverizing by using the formula: P = ∑ 1 n w i p i where wi is the weight factor, Σwi=1; and pi is the availability of each individual component of predetermined number of components and 0≦pi≦1. 12. A method for determining the availability of a mill for pulverizing solid fuels for use in a firing a steam generator, said mill having a predetermined number of components used in pulverizing said solid fuel comprising: calculating a mill availability indicator, P, where 0≦P≦1, in accordance with the following equation: P = ∑ 1 n w i p i where wi is the weight factor, Σwi=1; and pi is the availability of each individual component of said mill and 0≦pi<1. 13. The method of claim 12 wherein one of said predetermined number of components in said mill pulverizer is an assembly for holding one or more roller bearings and applying a preload on each of said one or more roller bearings and an assembly availability indicator, which is indicative of the thickness of said solid fuel in said mill pulverizer, is determined from: P 1 = 1 - α 1 | L | - | L 0 | | L 0 | where L is the value of the displacement of said assembly measured by a sensor attached to said assembly, L0 is the nominal value from said sensor, α1 is a predetermined coefficient and said weight factor is 0.1. 14. In combination: a roll-bowl type mill for pulverizing solid fuels for use in firing a steam generator, said pulverizing mill comprising: a) a bowl having a predetermined diameter; b) a journal assembly; c) one or more rollers each connected to said journal assembly through an associated roller bearing, each of said one or more rollers located a predetermined distance above said bowl; d) a journal spring shaft accessible from outside of said mill and connected onto said journal assembly, the movement of said journal assembly measurable through said journal spring shaft; e) a wall; and f) a trunion shaft, one or more vibration sensors mounted on the end of said trunion shaft to measure the vibration of said trunion shaft when said mill is operating, said trunion shaft connecting said journal assembly onto said mill wall; and a data acquisition system having as an input said trunion shaft vibration measured by said one or more vibration sensors, said having comprising: a computing device for predicting failure of each of said one or more said roller bearing from said trunion shaft vibration measured by said one or more vibration sensors by first transferring said measured shaft vibration to said location of each of said one or more roller bearings by a predetermined transfer function and then determining wear for each of said one or more roller bearings by analyzing using vibration pattern signature and/or order analysis methods the transferred signal from each of said one or more vibration sensors. | FIELD OF THE INVENTION This invention relates to the pulverizing of solid fuels such as coal in power generation plants and more particularly to the monitoring of and scheduling of maintenance for the pulverizer. DESCRIPTION OF THE PRIOR ART One of the most significant engineering achievements of the twentieth century is the commercial perfection of the coal pulverizer and methods for firing coal in pulverized form in a power generation plant. The function of a pulverizer in a coal combustion system is to reduce the size of the coal particles to fine powder. The reason for this is to increase the combustibility of the coal and the efficiency of the system. The development of the coal pulverizer is one of the cornerstones making possible the extremely large, modern, steam-generating unit with its high thermal efficiency, reliability and safety. Worldwide, almost all kinds of coal is being burned with complete success in pulverized form. Similarly, many other type of low-grade, waste, and byproduct solid fuels may also be fired economically and efficiently in this manner. The four main types of pulverizers are: Ball Tube Roll-Bowl or Ball Race Impact or Hammer Pulverizer Mill Attrition Type Each of the above types of pulverizers employs a different method of reducing the size of the coal particles. The variation in the design of these machines accounts for different characteristics in operation and maintenance. Across the design spectrum there can be found different aspects of operation that are more suited to different applications. Each one of the above four main pulverizer types are briefly described below. Ball Tube Mill The Ball Tube type pulverizers are made up of a large cylinder loaded to slightly less then half way with forged steel or cast alloy balls ranging from one to four inches in diameter. The coal is brought into the mill through piping, which directs the coal into screw loaders located at the sides of the cylinder. The coal is gravity fed into the system through the feeder, which governs the amount of coal delivered to the machine upon loading. The cylinder is lined with a wear resistant cast material that will not need to be replaced for years of use. The Ball Tube type mill rotates the cylinder with the balls and coal at a speed of about 18 to 35 rpm. This rotation causes the coal to be reduced in size through crushing under the alloy balls as well as wear from friction against the balls, liners and other coal particles, resulting from the rotational motion of the cylinder. A classifier is often used with this system in order to control the size of the coal particles that reach the burner. This type of pulverizer is considered to be a low speed machine. Roll-Bowl or Ball Race Mill Roll-Bowl or Ball Race is the name given to the pulverizer, which uses a Ring-Roll or Ball-Race combination in order to achieve the particle reduction of coal fuel. When the Ball-Race combination is used, the Balls are confined between two races. The races consist of two channels that are shaped such that the balls roll freely inside them. The races are held together by means of springs or some type of pneumatic or hydraulic rams. It is this applied pressure that gives the grinding force needed for the coal particles to be reduced. The lower race is generally driven in this machine but some designs use both races as the driving mechanism. When the Roll-Bowl combination is used, it is possible to drive the Bowl or the Roll. In either case the grinding force is obtained through the centrifugal force of the rollers. The pulverizer which uses the stationary rolls and the rotating ring are the most widely used type of pulverizer today. This type of machine also has a classifier that governs the particle sizes of the coal before they enter the burners. The coal is loaded through the center of the system by means of a pipe that travels through the machine. The coal is gravity fed and the amount of coal entering the system at one time is controlled by a feeder system. This system is a medium speed system. Impact or Hammer Pulverizer Mill An Impact or Hammer pulverizer mill uses the impact of the hammers on the coal particles as well as attrition with the smaller particles to obtain the particle size reduction. The machine is made of up a series of hammers that can be both hinged and fixed in positions. The coal is loaded into the system through one side and uses gravity to pull the coal into the area of the mill that causes the size reduction. These hammers revolve in an enclosed chamber lined with wear resistant materials. This design is considered to be a high speed Pulverizer. The speed causes wear problems, which also cause particle uniformity problems during the life of the system. The system may also have a classifier allowing the coal particle size to be monitored into the burner. Attrition Type Mill The Attrition mill, which is a high speed system, is not used for direct pulverization of coal due to the high wear of the machine parts. The main use of this type of pulverizer is the direct firing of pulverized coal. A rotating disc inside of an enclosed cylinder achieves the particle reduction. The disc has rows of pegs and lugs. The cylinder is lined with wear resistant materials and the pegs and lugs on the disc are also made from wear resistant materials to increase the life of the system. The high-speed of this mill is the main cause for the high wear of the machine and thus the short operating life of this system. The Pulverizer's Importance As is described above the purpose of the pulverizer is to reduce the size of the coal particles. The question is why is that important to the power generation process? The answer lays in the efficiency and emission problems faced by coal fired power plants today. These are extremely important factors in any process involving combustion due to the current state of the environment and cost reduction trends. The U.S. and other countries are putting a lot of effort into the improvement of the combustion of coal for power generation. This makes the pulverizer a very important asset to the plants as well as an asset, which cannot be replaced. The pulverizer is also very important to the performance of the plant for which it serves. This is the first process in the chain of power generation and the most time consuming. The pulverizer is responsible for drying and crushing the correct amount of coal according to how much power the plant has to generate. If the pulverized coal is not there to burn, the plant is unable to produce the power and will lose time, money and credibility in the grid it is supplying. Further poor operation or even failure of the coal pulverizer leads at best to plant de-rating or at worst unit shutdown. These things make the pulverizer a very essential part of the coal fired power production system, and justify improvements to both the pulverizer and its operation. As is described above, the coal pulverizer is essential to the use of coal in power generation. The pulverizer, which is located at the beginning of the process in the coal-fired power plant, crushes the coal into a fine power in order to be burned efficiently in the furnace. As is described below there are problems associated with the use of pulverizers in power plants and the occurrence of one or more of these problems can cause the pulverizer to be a “bottle neck” for the whole power generation process The major problems with pulverizers are: Dynamic unbalance—vibration Wear and failure of moving parts Lack of fineness, flow rate measurement and control Lack of failure detection and maintenance scheduling tools Slow response to the variation of the feed rate Outlet distribution imbalance Overloading related problems Pulverizer fire. Vibration and wear which is the cause of major part failure in the pulverizer and the lack of failure detection and maintenance scheduling tools have been identified as critical problems. Currently, there is no system or apparatus that can take care of these problems. Operation conditions and failures are now mainly determined by operator experience. The severe conditions around the coal mill prevents continuous monitoring of the mill's operating condition and prompt notification of the occurrence of a problem. Power generation capacity de-rating, damaging of the mill main driving shaft and even shutting down the plant sometime occur due to lack of checking up and on-time maintenance. Further, since there is today not any instrumentation to tell the operating condition for moving parts such as roller and roll bearings located inside of the mill, the power generation plant may perform unnecessary maintenance which increases the cost of power generation. The present invention which is a hardware/software system that monitors coal mill operating condition, detects and predicts mill failure, schedules maintenance activities and estimates coal fineness of the pulverized coal in order to optimize the coal pulverizing process for the power generation plant solves the critical problems described above. SUMMARY OF THE INVENTION In combination: a roll-bowl type mill for pulverizing solid fuels for use in firing a steam generator, the pulverizing mill comprising: a) a bowl having a predetermined diameter; b) one or more rollers each connected to an assembly through an associated roller bearing, the assembly for holding each of the one or more rollers and for applying a preload on each of the one or more rollers, each of the one or more rollers located a predetermined distance above the bowl; and c) one or more linear transducers mounted on the assembly to measure the displacement of the movement of the assembly when the mill is operating; a data acquisition system having as an input the assembly movement displacement measured by the one or more linear transducers comprising: a computing device for data collection and frequency power spectrum analysis of the assembly shaft displacement to determine: a) the diameter, D, of each of the one or more rollers by using the formula: D=Fb/Fr Db where, Fb is the bowl frequency and Fr is the roller frequency determined by power spectrum analysis respectively, and Db is the bowl predetermined diameter. In combination: a roll-bowl type mill for pulverizing solid fuels for use in firing a steam generator, the pulverizing mill comprising: a) a bowl having a predetermined diameter; b) one or more rollers each connected to an assembly through an associated roller bearing, the assembly for holding each of the one or more rollers and for applying a preload on each of the one or more rollers, the one or more rollers located a predetermined distance above the bowl; and c) one or more linear transducers mounted on the assembly to measure the displacement of the movement of the assembly when the mill is operating; a data acquisition system having as an input the assembly movement displacement measured by the one or more linear transducers comprising: a computing device for data collection and frequency power spectrum analysis of the assembly shaft displacement to determine the reduction and/or depth of wear cup, H, of each of the one or more rollers by using the formula: D 1 = 2 R 1 = F b F r 1 D b D 2 = 2 R 2 = F b F r 2 D b H = R 1 - R 2 = | F r 2 - F r 1 | F b D b 2 F r 1 F r 2 where, Fr1 is the dominant roller frequency peak from power spectrum analysis Fr2 is the secondary roller frequency peak from power spectrum analysis. In combination: a roll-bowl type mill for pulverizing solid fuels for use in firing a steam generator, the pulverizing mill comprising: a) a bowl having a predetermined diameter; b) one or more rollers each connected to an assembly through an associated roller bearing, the assembly for holding each of the one or more rollers and for applying a preload on each of the one or more rollers, the one or more rollers located a predetermined distance above the bowl; and c) one or more linear transducers mounted on the assembly to measure the displacement of the movement of the assembly when the mill is operating; a data acquisition system having as an input the assembly movement displacement measured by the one or more linear transducers comprising: a computing device for data collection and frequency power spectrum analysis of the assembly shaft displacement to determine the relative thickness of the solid fuel in the mill by using the formula: L 1 = β | L | - | L 0 | | L 0 | , where L is the value of the displacement of the journal spring shaft measured by the one or more linear transducers, L0 is the calibrated value from the one or more transducers, and β is a coefficient. A system comprising: a mill for pulverizing solid fuels for use in firing a steam generator, the mill comprising a predetermined number of components used in pulverizing the solid fuel; and a processing device for determining an indicator P, where 0≦P≦1, for presenting the availability of the mill to perform the solid fuel pulverizing by using the formula: P = ∑ 1 n w i p i where wi is the weight factor, Σwi=1; and pi is the availability of each individual component of the predetermined number of components and 0≦pi≦1. An apparatus for use with a mill for pulverizing solid fuels for use in firing a steam generator, the mill comprising a predetermined number of components used in pulverizing the solid fuel, the apparatus comprising: a computing device for determining an indicator P, where 0≦P≦1, for presenting the availability of the mill to perform the solid fuel pulverizing by using the formula: P = ∑ 1 n w i p i where wi is the weight factor, Σwi=1; and pi is the availability of each individual component of predetermined number of components and 0≦pi≦1. A computer readable medium having instructions for causing a computer to execute a method comprising: determining an indicator P, where 0≦P≦1, for presenting the availability of a mill for pulverizing solid fuels for use in firing a steam generator, the mill comprising a predetermined number of components used in pulverizing the solid fuel, to perform the solid fuel pulverizing by using the formula: P = ∑ 1 n w i p i where wi is the weight factor, Σwi=1; and pi is the availability of each individual component of predetermined number of components and 0≦pi≦1. A method for determining the availability of a mill for pulverizing solid fuels for use in a firing a steam generator, the mill having a predetermined number of components used in pulverizing the solid fuel comprising: calculating a mill availability indicator, P, where 0≦P≦1, in accordance with the following equation: P = ∑ 1 n w i p i where wi is the weight factor, Σwi=1; and pi is the availability of each individual component of the mill and 0≦pi≦1. In combination: a roll-bowl type mill for pulverizing solid fuels for use in firing a steam generator, the pulverizing mill comprising: a) a bowl having a predetermined diameter; b) a journal assembly; c) one or more rollers each connected to the journal assembly through an associated roller bearing, each of the one or more rollers located a predetermined distance above the bowl; d) a journal spring shaft accessible from outside of the mill and connected onto the journal assembly, the movement of the journal assembly measurable through the journal spring shaft; e) a wall; and f) a trunion shaft, one or more vibration sensors mounted on the end of the trunion shaft to measure the vibration of the trunion shaft when the mill is operating, the trunion shaft connecting the journal assembly onto the mill wall; and a data acquisition system having as an input the trunion shaft vibration measured by the one or more vibration sensors, the having comprising: a computing device for predicting failure of each of the one or more the roller bearing from the trunion shaft vibration measured by the one or more vibration sensors by first transferring the measured shaft vibration to the location of each of the one or more roller bearings by a predetermined transfer function and then determining wear for each of the one or more roller bearings by analyzing using vibration pattern signature and/or order analysis methods the transferred signal from each of the one or more vibration sensors. DESCRIPTION OF THE DRAWING FIG. 1 illustrates the Roll-Bowl coal pulverizer mill including the mill advisor system of the present invention. FIG. 2 shows one embodiment for the data acquisition system that is part of the mill advisor system of the present invention. FIGS. 3a to 3c are photographs showing the mounting methods for the sensors used in the mill operation sensing system which is part of the present invention and their location on the Roll-Bowl mill. FIG. 4 shows the user interface for the stand alone PC that was in one embodiment part of the data acquisition system. FIG. 5a shows a model for the roller trunion system of the Roll-Bowl mill and FIG. 5b shows the mill of FIG. 1 with the trunion, journal spring and roller shafts easily identifiable. FIG. 6 shows using data from an typical mill a plot for the transfer function that is used to determine the amplitude of the tangential force of the roller bearing of the mill. FIG. 7 shows another embodiment for a roll-bowl type pulverizing mill. DESCRIPTION OF THE PREFERRED EMBODIMENT(S) The present invention also known as the “mill advisor” is a hardware/software system that includes a sensing system, a data acquisition system, a data processing module, an expert system rules and an error recording and reporting system. The mill operation sensing system includes a displacement sensor, a vibration sensor, and pressure and temperature sensors as well as other sensors. The data acquisition system may be PC-based as in the embodiment described herein or a module embedded in a power plant control system such as a distributed control system (DCS). The data processing software module uses a vibration signal processing algorithm to monitor the operating condition of the moving parts and predict the failure. An expert system extracts mill operation and maintenance engineer's knowledge, sets up the rules and generates operation advice and maintenance schedules. Any commercially available expert system software can be used as the expert system in the system of the present invention. The error recording and reporting system is a software module that records the processed history data and sends out a report regularly or a warning when urgent problems occur. This invention is described herein in connection with the Roll-Bowl type pulverizer which is the most widely used type of pulverizer in the power generation industry. The invention can be used for other types of coal mills as well although some specific functions may need to be modified to fit that particular mill type. FIG. 1 shows symbolically the mill advisor system of the present invention in connection with a Roll-Bowl coal pulverizer mill 10 of the RS type mill sold by the former Combustion Engineering (CE). FIG. 1 also shows the parameters sensed in the mill 10 and the location of the sensors 12-26 on the mill. The sensors 12-26 and their functions are: Body vibration sensor 12—this sensor is an accelerometer, to monitor overall mill vibration. Analyzing and comparing the signal from this sensor with a benchmark for a particular mill will give the overall health condition and failure prediction for that mill. Trunion shaft vibration sensors 14—these sensors are accelerometers, to monitor the vibration of the trunion shaft. Analyzing the signal from these sensors will tell the degree of wear of the roller bearing and predict the failure of the bearings. There is one sensor for each of three trunion shafts in pulverizer 10. Journal spring shaft displacement sensors 16—these sensors are LVDTs, to measure the displacement of the roller journal movement. Analyzing the signal from these sensors can give information on the pulverizing process including the coal depth in the mill 10. Worm shaft vibration sensor 18—this sensor is an accelerometer, to monitor the worm shaft that is connected to the driving motor shaft. Main gear box unbalance and failure of the main shaft can be obtained from this sensor signal. Fuel feed rate sensor 20—this sensor measures the coal feed rate. Motor AMP meter 22—this sensor measures the driving motor power input. Pressure meter 24—this sensor measures the pressure at different locations inside of the mill 10. Temperature meters 26—these sensors measure the temperature at different locations in the mill 10. The mill advisor system of the present invention indicated symbolically by 28 in FIG. 1 collects the information from all of the sensors 12-26 and other operating parameters of the mill 10, analyzes them, and gives advice to the operator, maintenance personnel and management in an on-line manner. In addition to the sensing system described above, one embodiment for system 28 that was built and tested included the data acquisition system, data processing module, expert system rules for the expert system software used in the present invention and error recording and reporting system described below. The data acquisition system 30 for this one embodiment is as is shown in FIG. 2 PC-based. System 30 includes a stand alone PC 32 that has a plug-in data acquisition (DAQ) card 34. The DAQ card 34, which as of the filing date of the U.S. patent application was available from National Instruments, 11500 N Mopac Expwy, Austin, Tex. 78759-3504, acquires the analog signals from the displacement sensor such as LVDT 16, vibration sensors such as accelerometers 12, 14 and 18 as well as process related sensor data such as feed rate from sensor 20 and bowl pressure difference from sensor 22 and the output of sensors 22 and 24. FIGS. 3a-c are photographs showing the mounting methods for the sensors and their locations on the mill 10. The displacement sensor which is a LVDT 16 on the journal spring shaft 38 is placed as is shown in FIG. 3a between the moving journal shaft assembly and the non-moving mill body. A special fixture 40 is used. The fixture is attached on the moving journal shaft assembly and holds the LVDT cylinder. The LVDT probe is screwed on a magnetic pad 42, which is attached on the mill body through magnetic force. The vibration sensor 14 on the Trunion shaft 44 is placed on the end of the shaft by magnetic pad or adhesive pad 46 as shown in FIG. 3b. The vibration sensor 18 for the worm shaft 48 is as is shown in FIG. 3c placed on the outer ring of the worm shaft bearing assembly. Again a magnetic or adhesive pad 50 can be used. A software system was implemented in stand alone PC 32 to record and analyze the data. FIG. 4 shows the user interface for the stand alone PC. The software system performs the following functions: collects signals from all channels and stores them on a tape recorder; converts the data into corresponding engineering units and performs a FFT analysis; uses power spectrum analysis of the journal spring shaft displacement to identify the main shaft and roller rotation frequencies and further estimate the roller wear; uses the well known vibration pattern signature and/or order analysis method to detect gearbox, roller bearing wear and other major rotation parts' failure; calculates the mill health indicator based on vibration and operation parameters; and reports/displays the result. To calculate the roller diameters through frequency analysis, the following equations are used: D=Fb/FrDb Here, D—roller diameter Fr—roller frequency from power spectrum analysis Fb—bowl frequency (main frequency of the system) from power spectrum analysis Db—Bowl diameter, it is constant for a particular mill Cup type wear mode is commonly found in the roller wear process. When a wear cup occurs on the roller, double (sometimes multiple) roller frequencies appear in the power spectrum frequency analysis. In this case, the depth of the wear cup is estimated by using the following equations under the assumption that two or more equivalent roller diameters will take effect in the roller frequency generation around the major one: D 1 = 2 R 1 = F b F r 1 D b D 2 = 2 R 2 = F b F r 2 D b H = R 1 - R 2 = | F r 2 - F r 1 | F b D b 2 F r 1 F r 2 where, Fr1—dominant roller frequency peak from power spectrum analysis Fr2—secondary roller frequency peak from power spectrum analysis H—the depth of wear cup. A roller-trunion system for mill 10 was modeled in vibration aspect. The vibration signal transfer function is built to be used in moving part failure prediction through vibration monitoring. The model for the roller-trunion system is illustrated in FIG. 5a. The model shows the T, that is, trunion, shaft, the roller shaft including the end of the roller shaft adjacent the roller bearing and the end of the roller shaft adjacent the position of the T shaft and the equivalent support spring for the shafts. The roller shaft is rigidly connected to the trunion shaft and as is shown in FIG. 5b, which is another drawing of the mill 10 shown in FIG. 1, the roller shaft 52, trunion shaft 54 and journal spring shaft 56 are components of the assembly that holds each of the rollers and applies a preload for each of the rollers. The movement equations of torsional vibration of roller shaft ends due to excitation force from roller bearing can be expressed as J{umlaut over (φ)}+c{dot over (φ)}+KShaft(φ−φ′)=fr (1) J′{umlaut over (φ)}′+c′{dot over (φ)}′+KShaft(φ′−φ)+Ksupportφ′=0 (2) And the displacement of T (trunion) shaft end can be determined by z′=φ′L (3) Let f=Feiωt,φ=Aeiωt,φ′=A′eiωt,z′=Z′eiax (4) Substituting into Equation (1), (2) and (3) leads to [ K Shaft - ω 2 J + i ω c - K Shaft - K Shaft K Shaft + K Support - ω 2 J ′ + i ω c ′ ] ( A A ′ ) = ( Fr 0 ) ( 5 ) Z ′ = LA ′ ( 6 ) The transfer function can be obtained as A F = r ( K Shaft + K Support - ω 2 J ′ + i ω c ′ ) ( K Shaft - ω 2 J + i ω c ) ( K Shaft + K Support - ω 2 J ′ + i ω c ′ ) - K Shaft 2 ( 7 ) A ′ F = rK Shaft ( K Shaft - ω 2 J + i ω c ) ( K Shaft + K Support - ω 2 J ′ + i ω c ′ ) - K Shaft 2 ( 8 ) Z ′ F = L A ′ F = rLK Shaft ( K Shaft - ω 2 J + i ω c ) ( K Shaft + K Support - ω 2 J ′ + i ω c ′ ) - K Shaft 2 ( 9 ) The amplitude of the tangential force of the bearing can be calculated as: | F | = | Z ′ | | Z ′ F | = | A | ω 2 | Z ′ F | ( 10 ) where |A| is the amplitude of acceleration measured at T shaft end in the Z direction. Using a data set from a typical mill, the transfer function to be simulated and plotted is shown in FIG. 6. A health indicator is calculated to represent the health condition of the coal mill. The health indicator formula is based on the following assumptions: The failure of each component of mill 10 has its own contribution to the overall failure of the mill. As can be appreciated the failure contribution of each component is or may be different than the failure contribution of the other components to the overall mill failure. Mill availability, in terms of variation from normal operating condition and process parameters, are identifiable for major components of the mill 10. Based on a general probability rule, the calculation formula is as follows: P = ∑ 1 n w i p i where, P is the health indicator (availability of the mill), 0≦P≦1; wi is the weight factor, Σwi=1; pi is the availability of each individual component of the mill, 0≦pi≦1. The components can be but are not limited to the following parameters: 1) Journal displacement from LVDT 2) Pressure difference across the bowl 3) Roller wear condition 4) Roller bearing condition 5) Mill body vibration 6) Mill worm shaft vibration 7) Outlet temperature 8) Driving motor input AMPs and coal feed rate. The following is a typical set of formulas with a brief description for each of the above parameters: 1) Journal displacement measurement shows the thickness of coal in the pulverizer 10. Too little or too much coal in the mill 10 indicates a mill health problem. P 1 = 1 - α 1 | L | - | L 0 | | L 0 | , w 1 = 0.1 Here, L is the measured LVDT value; L0 is nominal LVDT value; w1 is the weight factor and α1 is a coefficient. 2) Pressure difference across the bowl should keep a certain value for normal operation condition. P 2 = 1 - α 2 | P | - | P 0 | | P 0 | , w 2 = 0.08 Here, P is measured pressure difference value; P0 is nominal value. 3) Roller wear condition is determined by analyzing the main shaft and roller frequencies. The closer the roller frequency is to the main shaft frequency, the worse is the wear condition. P 3 = 1 - α 3 F r - F m F m , w 3 = 0.12 Here, Fr is roller frequency; Fm is main shaft frequency. 4) Roller bearing condition is detected by the vibration monitoring system through the vibration sensor on the end of trunion shaft for each roller. Using the bearing tune frequency and bench mark methods, the condition of the roller bearing condition is estimated. P4=1−SOBF, w4=0.15 Here, SOBF is a numerical value for Severity Of Bearing Failure. 0<SOBF<1. 5) Mill body vibration tells the overall vibration condition of the mill. The health indicator is reduced when the amplitude of the vibration exceeds the nominal bench mark value. P 5 = { 1 - α 5 A - A 0 A 0 , A < A 0 1 , A ≦ A 0 , w 5 = 0.15 Here, A is amplitude of measured body vibration; A0 is the nominal or benchmark value of the vibration. 6) Worm shaft vibration is considered in the similar way as body vibration. P 6 = { 1 - α 6 A - A 0 A 0 , A < A 0 1 , A ≦ A 0 , w 6 = 0.15 Here, A is amplitude of measured worm shaft vibration and A0 is the nominal value of A. 7) Outlet temperature should not be away from its set value. Deviation from the set value will affect the mill health condition. P 7 = 1 - α 7 T - T 0 T 0 , w 7 = 0.1 Here, T is the measured outlet temperature and T0 is its set value. 8) The ratio of driving motor input AMPs and coal feed rate represents the pulverizing efficiency of a mill. Decreasing of this ratio indicates the decline of the mill health condition. P 8 = 1 - α 8 R - R 0 R 0 , w 8 = 0.15 While the present invention is described herein with respect to an embodiment for a CE RS type roll bowl mill it should be appreciated that the invention may also be used with other types of roll bowl mills such as the Roll Wheel™ (previously known as the MSP) type roll bowl mill sold as of the filing date of the U.S. patent application by The Babcock and Wilcox Company shown in FIG. 7 as 60. Mill 60 includes three roll wheel assemblies 62. It is to be understood that the description of the preferred embodiment(s) is (are) intended to be only illustrative, rather than exhaustive, of the present invention. Those of ordinary skill will be able to make certain additions, deletions, and/or modifications to the embodiment(s) of the disclosed subject matter without departing from the spirit of the invention or its scope, as defined by the appended claims. | <SOH> FIELD OF THE INVENTION <EOH>This invention relates to the pulverizing of solid fuels such as coal in power generation plants and more particularly to the monitoring of and scheduling of maintenance for the pulverizer. | <SOH> SUMMARY OF THE INVENTION <EOH>In combination: a roll-bowl type mill for pulverizing solid fuels for use in firing a steam generator, the pulverizing mill comprising: a) a bowl having a predetermined diameter; b) one or more rollers each connected to an assembly through an associated roller bearing, the assembly for holding each of the one or more rollers and for applying a preload on each of the one or more rollers, each of the one or more rollers located a predetermined distance above the bowl; and c) one or more linear transducers mounted on the assembly to measure the displacement of the movement of the assembly when the mill is operating; a data acquisition system having as an input the assembly movement displacement measured by the one or more linear transducers comprising: a computing device for data collection and frequency power spectrum analysis of the assembly shaft displacement to determine: a) the diameter, D, of each of the one or more rollers by using the formula: in-line-formulae description="In-line Formulae" end="lead"? D=F b /F r D b in-line-formulae description="In-line Formulae" end="tail"? where, F b is the bowl frequency and F r is the roller frequency determined by power spectrum analysis respectively, and D b is the bowl predetermined diameter. In combination: a roll-bowl type mill for pulverizing solid fuels for use in firing a steam generator, the pulverizing mill comprising: a) a bowl having a predetermined diameter; b) one or more rollers each connected to an assembly through an associated roller bearing, the assembly for holding each of the one or more rollers and for applying a preload on each of the one or more rollers, the one or more rollers located a predetermined distance above the bowl; and c) one or more linear transducers mounted on the assembly to measure the displacement of the movement of the assembly when the mill is operating; a data acquisition system having as an input the assembly movement displacement measured by the one or more linear transducers comprising: a computing device for data collection and frequency power spectrum analysis of the assembly shaft displacement to determine the reduction and/or depth of wear cup, H, of each of the one or more rollers by using the formula: D 1 = 2 R 1 = F b F r 1 D b D 2 = 2 R 2 = F b F r 2 D b H = R 1 - R 2 = | F r 2 - F r 1 | F b D b 2 F r 1 F r 2 where, F r1 is the dominant roller frequency peak from power spectrum analysis F r2 is the secondary roller frequency peak from power spectrum analysis. In combination: a roll-bowl type mill for pulverizing solid fuels for use in firing a steam generator, the pulverizing mill comprising: a) a bowl having a predetermined diameter; b) one or more rollers each connected to an assembly through an associated roller bearing, the assembly for holding each of the one or more rollers and for applying a preload on each of the one or more rollers, the one or more rollers located a predetermined distance above the bowl; and c) one or more linear transducers mounted on the assembly to measure the displacement of the movement of the assembly when the mill is operating; a data acquisition system having as an input the assembly movement displacement measured by the one or more linear transducers comprising: a computing device for data collection and frequency power spectrum analysis of the assembly shaft displacement to determine the relative thickness of the solid fuel in the mill by using the formula: L 1 = β | L | - | L 0 | | L 0 | , where L is the value of the displacement of the journal spring shaft measured by the one or more linear transducers, L 0 is the calibrated value from the one or more transducers, and β is a coefficient. A system comprising: a mill for pulverizing solid fuels for use in firing a steam generator, the mill comprising a predetermined number of components used in pulverizing the solid fuel; and a processing device for determining an indicator P, where 0≦P≦1, for presenting the availability of the mill to perform the solid fuel pulverizing by using the formula: P = ∑ 1 n w i p i where w i is the weight factor, Σw i =1; and p i is the availability of each individual component of the predetermined number of components and 0≦p i ≦1. An apparatus for use with a mill for pulverizing solid fuels for use in firing a steam generator, the mill comprising a predetermined number of components used in pulverizing the solid fuel, the apparatus comprising: a computing device for determining an indicator P, where 0≦P≦1, for presenting the availability of the mill to perform the solid fuel pulverizing by using the formula: P = ∑ 1 n w i p i where w i is the weight factor, Σw i =1; and p i is the availability of each individual component of predetermined number of components and 0≦p i ≦1. A computer readable medium having instructions for causing a computer to execute a method comprising: determining an indicator P, where 0≦P≦1, for presenting the availability of a mill for pulverizing solid fuels for use in firing a steam generator, the mill comprising a predetermined number of components used in pulverizing the solid fuel, to perform the solid fuel pulverizing by using the formula: P = ∑ 1 n w i p i where w i is the weight factor, Σw i =1; and p i is the availability of each individual component of predetermined number of components and 0≦p i ≦1. A method for determining the availability of a mill for pulverizing solid fuels for use in a firing a steam generator, the mill having a predetermined number of components used in pulverizing the solid fuel comprising: calculating a mill availability indicator, P, where 0≦P≦1, in accordance with the following equation: P = ∑ 1 n w i p i where w i is the weight factor, Σw i =1; and p i is the availability of each individual component of the mill and 0≦p i ≦1. In combination: a roll-bowl type mill for pulverizing solid fuels for use in firing a steam generator, the pulverizing mill comprising: a) a bowl having a predetermined diameter; b) a journal assembly; c) one or more rollers each connected to the journal assembly through an associated roller bearing, each of the one or more rollers located a predetermined distance above the bowl; d) a journal spring shaft accessible from outside of the mill and connected onto the journal assembly, the movement of the journal assembly measurable through the journal spring shaft; e) a wall; and f) a trunion shaft, one or more vibration sensors mounted on the end of the trunion shaft to measure the vibration of the trunion shaft when the mill is operating, the trunion shaft connecting the journal assembly onto the mill wall; and a data acquisition system having as an input the trunion shaft vibration measured by the one or more vibration sensors, the having comprising: a computing device for predicting failure of each of the one or more the roller bearing from the trunion shaft vibration measured by the one or more vibration sensors by first transferring the measured shaft vibration to the location of each of the one or more roller bearings by a predetermined transfer function and then determining wear for each of the one or more roller bearings by analyzing using vibration pattern signature and/or order analysis methods the transferred signal from each of the one or more vibration sensors. | 20040227 | 20070605 | 20051201 | 69120.0 | 0 | PAHNG, JASON Y | METHOD AND APPARATUS FOR SOLID FUEL PULVERIZING OPERATION AND MAINTENANCE OPTIMIZATION | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,788,854 | ACCEPTED | Method and apparatus for reducing the energy consumption of elevators equipped with SCR drives | The invention is directed to an apparatus and methods for enhancing the energy efficiency of a variable speed drive (VSD) used to control an elevator by disconnecting the VSD from the AC power supply grid when the elevator is idle and reconnecting the VSD when the elevator becomes active. One embodiment of the invention comprises an alternating current power supply grid, one or more variable speed drives, contactors connected between the alternating current power supply grid and the variable speed drive(s) that are used to connect or disconnect the variable speed drive(s) from the alternating current power supply grid, and, a control system that controls the contactors. The contactors may comprise a coil which is powered by the control system to either connect or disconnect the VSDs and the AC power supply grid. | 1. An energy efficient elevator system comprising: an alternating current power supply grid; one or more variable speed drives for driving elevators motors; one or more contactors connected between the alternating current power supply grid and the variable speed drive(s), and capable of connecting or disconnecting the variable speed drive(s) from the alternating current power supply grid; and a control system connected to the alternating current power supply grid, the control system having an output device connected to the contactor(s) and controlling the contactors to connect or disconnect the variable speed drive(s) from the alternating current power supply grid. 2. The energy efficient elevator system of claim 1 comprising a three phase AC power source. 3. The energy efficient elevator system of claim 1 wherein: the variable speed drive(s) comprise an isolation transformer having a line side, one or more silicon controlled rectifiers, a control circuit and a ripple filter; and, the contactor(s) are connected to the line side of the isolation transformer of each variable speed drive. 4. The energy efficient elevator system of claim 1 or 3 wherein: the contactors comprise a coil; and the control system output device supplies power to the coil of the contactor to connect each variable speed drive to the alternating current power supply grid and cuts power to the coil of the contactor to disconnect each variable speed drive from the alternating current power supply grid. 5. An energy efficient elevator system comprising: an alternating current power supply grid; one or more variable speed drives for driving elevator motors; one or more solid-state devices connected between the alternating current power supply grid and the variable speed drive(s), and capable of connecting or disconnecting the variable speed drive(s) from the alternating current power supply grid; and a control system connected to the alternating current power supply grid, the control system having an output device connected to the solid-state device(s) and controlling the solid-state device(s) to connect or disconnect the variable speed drive(s) from the alternating current power supply grid. 6. The energy efficient elevator system of claim 5 wherein: the solid-state device(s) comprise a gate; and the control system output device closes the gate to connect each variable speed drive to the alternating current power supply grid and opens the gate to disconnect each variable speed drive from the alternating current power supply grid. 7. The energy efficient elevator system of claim 1 or 5 wherein the control system controls the contactor(s) to disconnect variable speed drive(s) that are idle for at least 60 seconds and connect variable speed drive(s) that are or become active. 8. A method of enhancing the energy efficiency of an elevator system by using the energy efficient elevator system of claim 1 or 5. | BACKGROUND Virtually all of the high speed elevators installed prior to 1975 used direct current (DC) motors. The source of the direct current was typically a motor-generator (MG) set. The alternating current (AC) motor of the MG set was connected to an AC supply grid powered by the three phase AC supply of the building. Between 1975 and the early 1990's the majority of new high speed elevators were manufactured with DC motors supplied by a variable speed drive (VSD) that consisted of an isolation transformer, silicon controlled rectifiers, control electronics, and a ripple filter. This same VSD system was also used to modernize thousands of existing elevators. The existing DC motor was retained and the MG was replaced by the VSD. The silicon controlled rectifier variable speed drive (SCR VSD) is considered to be much more energy efficient than the MG set because the MG set was turning even if the elevator was stopped. However, the SCR VSD wastes significant energy because the isolation transformer was always connected to the power supply grid. Additionally, the SCR VSD supplied standby power (approximately 50% of running current) to the motor field. This power was typically supplied 24 hours a day, 365 days a year. The only time the VSD was not connected and consuming power was during maintenance. SUMMARY OF THE INVENTION The invention is directed to an apparatus and methods for enhancing the energy efficiency of a variable speed drive 15 (VSD) used to control an elevator by disconnecting the VSD from the AC power supply grid when the elevator is idle and reconnecting the VSD when the elevator becomes active. One embodiment of the invention comprises an alternating current power supply grid, one or more variable speed drives, contactors connected between the alternating current power supply grid and the variable speed drive(s) that are used to connect or disconnect the variable speed drive(s) from the alternating current power supply grid, and, a control system that controls the contactors. The invention may be powered by a three phase AC power source. The variable speed drives may comprise an isolation transformer having a line side, one or more silicon controlled rectifiers, a control circuit and a ripple filter and the contactor(s) could be connected to the line side of the isolation transformer of each variable speed drive. The contactors may comprise a coil which is powered by the control system to connect or disconnect the VSDs and the AC power supply grid. Solid-state devices may be used instead of contactors, and the control system may control the gates of the solid-state devices to connect or disconnect the VSDs and the AC power supply grid. In one embodiment, the control system disconnects VSDs that are idle for a fixed time period, such as 60 seconds. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram depicting an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION The invention enhances the energy efficiency of variable speed drives (VSD) used to control elevators by disconnecting the VSDs from the AC power supply grid when the elevators are idle and connecting the VSDs to the AC power supply grid when the elevators are or become active. In preferred embodiment, an elevator is powered by a DC motor 10 controlled by a variable speed drive 15 (VSD) is having an isolation transformer, a plurality of silicon controlled rectifiers, control electronics, and a ripple filter. A three phase contactor 21 is connected to the line side of the isolation transformer of the VSD 15 and the AC supply grid 25. A control system, such as logic controller 28 is connected to AC supply grid 25 and has an output device 30 connected to the three phase contactor 21 that controls the three phase contactor to disconnect the VSD 15 from an AC supply grid 25 when elevator service is not required. When the control system 28 supplies power to the coil of the contactor 21, the contactor 21 connects the VSD 15 to the AC supply grid 25. When the control system 28 does not supply power to the coil of the contactor 21, the contactor 21 disconnects the VSD 15 from the AC supply grid 25. The control system 28 remains connected to and continues to be powered by the AC supply grid 25 even when the VSD 15 is disconnected from the AC supply grid. In an alternate embodiment, the contactor is replaced with a solid state device, such as a switch. In this case, the control system has an output device that controls the gate of the solid state device. The control system may include software, firmware or hardware to connect or disconnect the VSD from the AC supply grid based upon demand for an elevator. In one embodiment, the VSD is disabled if there is no demand for an elevator for a fixed period of time, such as 60 seconds. Since the VSD executes a startup sequence and self diagnostic routine that takes several seconds each time the VSD is connected or reconnected to the AC supply grid, the VSD should not be disabled each time the elevator stops at a floor. It is envisioned that a typical elevator would have the VSD disabled over 12 hours a day during the work week and for a much longer time in periods of light use, such as weekends and holidays. A typical elevator consumes 1 to 2 kilowatts when on standby which can be saved with this invention. | <SOH> BACKGROUND <EOH>Virtually all of the high speed elevators installed prior to 1975 used direct current (DC) motors. The source of the direct current was typically a motor-generator (MG) set. The alternating current (AC) motor of the MG set was connected to an AC supply grid powered by the three phase AC supply of the building. Between 1975 and the early 1990's the majority of new high speed elevators were manufactured with DC motors supplied by a variable speed drive (VSD) that consisted of an isolation transformer, silicon controlled rectifiers, control electronics, and a ripple filter. This same VSD system was also used to modernize thousands of existing elevators. The existing DC motor was retained and the MG was replaced by the VSD. The silicon controlled rectifier variable speed drive (SCR VSD) is considered to be much more energy efficient than the MG set because the MG set was turning even if the elevator was stopped. However, the SCR VSD wastes significant energy because the isolation transformer was always connected to the power supply grid. Additionally, the SCR VSD supplied standby power (approximately 50% of running current) to the motor field. This power was typically supplied 24 hours a day, 365 days a year. The only time the VSD was not connected and consuming power was during maintenance. | <SOH> SUMMARY OF THE INVENTION <EOH>The invention is directed to an apparatus and methods for enhancing the energy efficiency of a variable speed drive 15 (VSD) used to control an elevator by disconnecting the VSD from the AC power supply grid when the elevator is idle and reconnecting the VSD when the elevator becomes active. One embodiment of the invention comprises an alternating current power supply grid, one or more variable speed drives, contactors connected between the alternating current power supply grid and the variable speed drive(s) that are used to connect or disconnect the variable speed drive(s) from the alternating current power supply grid, and, a control system that controls the contactors. The invention may be powered by a three phase AC power source. The variable speed drives may comprise an isolation transformer having a line side, one or more silicon controlled rectifiers, a control circuit and a ripple filter and the contactor(s) could be connected to the line side of the isolation transformer of each variable speed drive. The contactors may comprise a coil which is powered by the control system to connect or disconnect the VSDs and the AC power supply grid. Solid-state devices may be used instead of contactors, and the control system may control the gates of the solid-state devices to connect or disconnect the VSDs and the AC power supply grid. In one embodiment, the control system disconnects VSDs that are idle for a fixed time period, such as 60 seconds. | 20040227 | 20080520 | 20050901 | 66186.0 | 0 | SALATA, ANTHONY J | ENERGY EFFICIENT ELEVATOR SYSTEM | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,789,065 | ACCEPTED | Limb encircling therapeutic compression device | A therapeutic compression garment made of flexible, foldable, light weight Velcro-type loop fabric having a central region for wrapping partially around a body part and a plurality of bands integrally connected to the central region and extending outwardly in opposite directions from both sides of the central region to cross each other and encompass the body part. | 1. A garment for applying compression to a limb, said garment comprising: a. a central region having inner and outer surfaces, said central region comprising substantially inelastic material, and lateral regions disposed on opposite sides of the central region; b. a plurality of bands extending from said opposite lateral regions, each of said bands comprising i. a distal region, ii. proximal and distal edges, iii. inner and outer surfaces, iv. a fastener for detachably securing said distal region to a band extending from the opposite lateral region or to the opposite lateral or central region so as to encircle the limb and to draw the first lateral region toward the second longitudinal edge to stretch the central region and thereby provide a tension in the garment that will compress the limb. 2. The garment according to claim 1 wherein the central and lateral regions are biased into a three-dimensional curvature in order to fit the body part. 3. The garment of claim 2 wherein said opposing bands extend substantially perpendicular to a longitudinal axis of said central region, and said proximal and distal edges are substantially parallel to each other. 4. The garment of claim 2 in which wrapping engagement involves juxtaposition of at least a portion of the edges of each band with the edges of one or more opposing bands. 5. The garment of claim 2 in which wrapping engagement involves overlapping engagement of at least a portion of the upper and lower surfaces of opposing bands. 6. The garment of claim 1 wherein each of said bands extend from a lateral region at an angle with respect to a longitudinal axis of the central region, and said angle is independently selected for each band. 7. The garment of claim 6 wherein at least one set of opposing bands extends substantially perpendicular to a longitudinal axis of said central region, and said proximal and distal edges are substantially parallel to each other, and in which wrapping engagement involves overlapping engagement of at least a portion of the upper and lower surfaces of opposing bands; and at least one set of opposing bands extends at a non-normal angle to the longitudinal axis of the central region, in which the proximal and distal edges are substantially parallel to each other, and in which wrapping engagement involves overlapping engagement of at least a portion of the upper and lower surfaces of opposing bands. 8. The garment of claim 2 wherein a set of opposing bands comprise bands in which recesses are formed in a proximal or distal edge of said band, said recesses positioned for wrapping engagement by juxtaposition of the upper and lower recessional edges of opposing bands. 9. The garment of claim 1 for applying compression to a part of the body and having a system for measuring compression wherein said outer surface bears indicia printed thereon wherein measurement of a position of at least one of the indicia relative to a reference position on the outer surface provides a measurement of the stretch of the elastic material. 10. The garment of claim 9 further comprising a card having a scale for measuring the separation of the position of the at least one indicia from the reference position and providing the compression level for the pre-measured circumference of the body part in order to determine the actual compression provided by the garment and adjusting the compression provided by the garment accordingly. 11. The garment according to claim 1 further comprising a pocket attached to the garment adjacent at least the distal end of a band, the pocket having a compartment sized to admit at least one finger inserted through an opening in the pocket that faces in a direction substantially away from the distal end of the band, whereby a person can urge the end of the band around the body part by inserting at least one finger through the opening into the compartment of the pocket and pushing or pulling with the at least one finger toward the opposite side of the garment. 12. A method for applying therapeutic compression to a body part for treating a medical disorder which requires compression therapy, comprising the step of applying to said body part a garment, said garment comprising: a. a central region having inner and outer surfaces, said central region comprising substantially inelastic material, and lateral regions disposed on opposite sides of the central region; b. a plurality of bands extending from said opposite lateral regions, each of said bands comprising i. a distal region, ii. proximal and distal edges, iii. inner and outer surfaces, iv. a fastener for detachably securing said distal region to a band extending from the opposite lateral region or to the opposite lateral or central region so as to encircle the limb and to draw the first lateral region toward the second longitudinal edge to stretch the central region and thereby provide a tension in the garment that will compress the limb. 13. The method of claim 12 wherein said medical disorder is selected from the group consisting of lymphedema, phlebitis, varicose veins, post fracture edema, injury edema, stasis ulcers, obesity, circulatory disorders, and post-burn therapy. 14. A method for applying therapeutic compression to a body part comprising the step of applying to said body part a garment, said garment comprising: a. measuring a circumference of the body part; b. placing a therapeutic garment around said body part, said garment comprising i. a central region having inner and outer surfaces, said central region comprising substantially inelastic material, and lateral regions disposed on opposite sides of the central region; ii. a plurality of bands extending from said opposite lateral regions, each of said bands comprising i. a distal region, ii. proximal and distal edges, iii. inner and outer surfaces, iv. a fastener for detachably securing said distal region to a band extending from the opposite lateral region or to the opposite lateral or central region so as to encircle the limb and to draw the first lateral region toward the second longitudinal edge to stretch the central region and thereby provide a tension in the garment that will compress the limb, wherein said inner and/or outer surfaces bear indicia printed thereon wherein measurement of a position of at least one of the indicia relative to a reference position on the outer surface provides a measurement of the stretch of the elastic material; c. tensioning the garment to provide compression to the body part; measuring the stretch of the elastic material; d. selecting a compression scale appropriate to the measured circumference of the body part; and e. reading the compression scale to determine the compression provided to the body part. | BACKGROUND OF THE INVENTION This invention relates to devices for applying compression to parts of the body for therapeutic reasons. Compression applied to a body part, such as a limb, is essential for resolving many circulatory disorders. The application of compression at the appropriate level has therapeutic benefits. For example, it restores circulation, relieves swelling, treats pain, heals ulcers, and treats varicose veins. Elastic and inelastic garments have been employed in compression therapy of the limbs. Most of these garments suffer various degrees of shortcomings, particularly discomfort, loss of compression, difficulties in application and removal, lack of adjustability, and ineffectiveness. A desirable trait of compression devices is that they provide to the limb compression levels that are dynamic, fluctuating in response to short-term changes inside the body part. Compression requirements change as internal pressures change, depending on whether the patient is upright or prone. Furthermore, the movement of fluid out of a body part is facilitated by the pumping effect caused by fluctuations in pressures. Such pressure fluctuations can be enhanced by compression devices that resist changes in limb size, such as those that occur during muscle flexion. Patients have observed that stockings, wraps, and bandaging systems made entirely of elastic materials are uncomfortable. Fully elastic devices deliver an unchanging level of pressure, which alternately feels either “too tight” or “too loose” to the patient depending on the patient's position. These elastic systems also do not resist small changes in limb circumference, and hence do not provide the fluctuating pressures that are needed to assist with pumping fluid out of the body part. To be effective, compression devices need to maintain appropriate compression over time. Large changes can occur in limb volume, reflecting either diurnal fluctuations or progressive changes in the degree of swelling. Devices that provide compression through the wrapping of materials with limited elasticity, such as with the Unna's boot, cannot accommodate such changes in limb volume. For example, they may initially provide appropriate compression, which is dynamic in response to internal changes, but after hours of use the movement of fluid out of the limb will result in an overall loss of pressure. And because these systems are wrapped around the limb in layers, it is not practical to periodically remove and re-apply the wrapping at the appropriate compression level. In the case of more elastic systems, such as long-stretch bandages and elastic stockings, the greater elasticity helps them to sustain consistent compression levels over time. However, if changes in limb volume are great enough, pressures under the devices can go outside the appropriate therapeutic range. An additional problem with elastic stockings is that if they are sized incorrectly, or if the body part is of an irregular shape, the pressure could be incorrect under all or part of the garment from the onset. In the case of elastic bandages, it is easy to apply the layers at too high or low of a pressure, requiring a time-consuming removal and re-application. A useful trait of compression garments is that they be easy to apply and adjust. This helps to ensure appropriate, sustained compression levels by allowing the user to adjust to accommodate changes in limb volume, and enabling the garment to be adjusted to an exact fit regardless of limb shape. Being easy to apply also increases the likelihood that the patient will continue to use the device and obtain its therapeutic benefits. Stockings can not be adjusted and are difficult to slide onto the limb. Bandaging systems can not be adjusted without being removed completely, and require skill for proper application. Devices such as described in U.S. Pat. No. 5,653,244 are primarily inelastic, and can be adjusted through series of interlocking bands. As such they provide dynamic compression that can be sustained over time. However, because they are primarily inelastic, compression levels quickly go down with changes in volume, so sustaining compression requires frequent re-adjustment of the bands. Another consequence of being primarily inelastic is that it is more difficult to hold force in the bands while applying, and as a consequence, more effort is required by the user during application—either in the form of greater force, or the use of a greater number of bands on the garment. Furthermore, because the pairs of bands interlock—one member of a pair of bands passes through a hole in the other member—they require a certain amount of manual dexterity to apply. This is particularly disadvantageous, as many users are older or have other limitations of mobility. Compression devices are therefore needed that are easy to apply, and that provide compression that is both sustained (in that significant long-term changes in limb volume can be accommodated), and dynamic (such that short-term changes to internal pressure can be countered). To this end, compression devices are needed that provide the ability to apply and adjust compression as quickly and easily as possible. Compression devices are also needed that are inelastic enough to provide compression levels that respond dynamically to changes in patients' compression requirements, while still being elastic enough so that the device does not readily loose appropriate compression. A need also exists for compression devices that can be applied to parts of the body that have varying circumference and that are comfortable to wear throughout the day and in different postures. Sustained yet dynamic compression is key to proper treatment. It is often a problem with compression devices that the applied compression goes down over time or with changes in limb volume. It is often a problem with other devices that in order to sustain compression, the device must be so elastic that compression levels do not fluctuate with changes in patient need. Providing compression that has a low but significant level of elasticity, and having a means of easily adjusting compression levels, enables sustained and dynamic compression levels to be maintained. U.S. Pat. No. 3,845,769 relates to a boot having a split sleeve of essentially unyielding material shaped to fit a leg. The sleeve is held in position and compression is applied by a plurality of bands of interlocking fabric material, such as Velcro or Scotchmate. U.S. Pat. No. 4,215,687 relates to a combination or kit, which permits the in situ construction and assembly of a therapeutic compression device directly on the patient by a doctor or other skilled person. The combination or kit includes a Velcro-type anchoring tape having an interlocking fabric material on one side and a plurality of body or limb encircling Velcro-type bands which are assembled, one by one, in edge-to-edge relationship either by direct contact with the anchoring tape or by indirect contact through Velcro-type splicing means. These custom-made therapeutic compression devices have achieved wide recognition in healing leg ulcers and in the treatment of lymph edema. On the other hand, the custom construction which requires splicing of the body or limb encircling bands when they are too long and when the portion of the body or limb is contoured is a tedious and time consuming task. U.S. Pat. No. 5,120,300 relates to a compression band for use in the therapeutic device disclosed in U.S. Pat. No. 4,215,687 and, more particularly, to a compression band for quick and easy application to and removal from a body part. U.S. Pat. No. 5,254,122 relates to a therapeutic compression device of the type disclosed in U.S. Pat. No. 4,215,687 which includes a longitudinally extending splicing band or slide fastener which facilitates quick and easy removal of the device from the body or limb and quick and easy reapplication to the body or limb without the necessity of unthreading the adjusted compression bands. U.S. Pat. No. 5,653,244 relates to a therapeutic compression garment made of flexible, foldable, light weight Velcro-type loop fabric having a central region for wrapping partially around a body part and a plurality of pairs of bands integrally connected to the central region and extending outwardly in opposite directions from both sides of the central region to encompass the body part. One of the bands of each pair has a slot to accommodate the opposite band in threaded, folded relationship. U.S. Pat. Nos. 5,918,602 and 5,906,206 relate to the therapeutic garment disclosed in U.S. Pat. No. 5,653,244 and adapted for the leg in combination with an ankle-foot wrap for applying therapeutic compression to the leg, ankle and foot. U.S. Pat. No. 6,338,723 relates to a device for compression of objects such as parts of the body. The device has the form of a band sized to encircle the compressible object and having a component or components made of an elastic material. Indicia are printed on the device such that the stretch of the elastic material as the device is tensioned around the body part causes increased separation of the indicia or movement of a free end of the band with respect to the indicia. A system measures the separation of the indicia and converts it to compression as a function of the circumference of the body part. SUMMARY OF THE INVENTION The present invention is a garment for applying compression to a limb. The garment, which has inner and outer surfaces, comprises a central region of substantially inelastic material. Lateral regions are disposed on opposite sides of the central region. A plurality of bands extends from the opposite lateral regions. Each band comprises a distal region, proximal and distal edges, inner and outer surfaces, and a fastener for detachably securing the distal region to a band extending from the opposite lateral region or to the opposite lateral or central region. In use, the user encircles the limb, the inner surface of the garment placed against the limb, and draws the first lateral region toward the second longitudinal edge to stretch the central region and thereby provide a tension in the garment that will compress the limb. Preferred embodiments of the garment involve the central and lateral regions which are biased into a three-dimensional curvature in order to fit the body part. Various embodiments are provided in which the opposing bands extend either substantially perpendicular to a longitudinal axis of the central region, and the proximal and distal edges are substantially parallel to each other; or the bands extend from a lateral region at an angle with respect to a longitudinal axis of the central region; or combinations thereof. For example, an embodiment provides at least one set of opposing bands extends substantially perpendicular to a longitudinal axis of said central region, and at least one set of opposing bands extends at a non-normal angle to the longitudinal axis of the central region. Still other embodiments provide bands in which recesses are formed in either the proximal or distal edges of the bands to facilitate wrapping engagement by juxtaposition of the proximal and distal recessional edges of opposing bands. Other embodiments provide garments which bear an indicia system for measuring the compression which the garment applies to the limb. A preferred embodiment provides a card having a scale for measuring the separation of the position of the at least one indicia from the reference position. Reading the card in relation to the indicia system indicates the compression level for the pre-measured circumference of the body part, thereby permitting the user to determine the actual compression provided by the garment and to adjust the compression provided by the garment accordingly. The garment has an embodiment which comprises a pocket attached adjacent the distal end of a band. The pocket is sized to admit at least one finger inserted through an opening in the pocket that faces in a direction substantially away from the distal end of the band. The user can urge the end of the band around the body part by inserting at least one finger through the opening into the compartment of the pocket and pushing or pulling with the at least one finger toward the opposite side of the garment. In another aspect, the invention provides a method for applying therapeutic compression to a body part for treating a medical disorder which requires compression therapy. The method involves the step of applying with sufficient pressure to said body part a garment of the invention for a sufficient period of time to mitigate swelling in the limb. The method is suitable for treating medical disorders such as lymphedema, phlebitis, varicose veins, stasis ulcers, obesity, circulatory disorders; and for treating swelling due to traumas such as post-fracture edema, injury edema, and post-burn therapy. OBJECTS OF THE INVENTION An object of the present invention therefore is to provide a substantially non-elastic therapeutic compression garment allowing the user to more easily apply the garment without threading or interlocking all of the bands. Another object of the present invention therefore is to provide a therapeutic compression garment of simpler design so labor and material costs are significantly reduced. Yet another object of the present invention is to provide a therapeutic compression garment with a smoother more conforming fit by incorporating slightly elastic materials. Another object of the present invention is to provide a therapeutic compression garment that is comfortable to wear. Yet another object of the present invention is to provide a therapeutic compression garment, which by providing a slightly greater resting pressure through use of elastic materials or through the use of curved limb-shape accommodating seams, does not slide on the limb. Still another object of the invention is to provide a therapeutic compression garment that provides effective treatment. Another object of the invention is to provide a therapeutic compression garment that will provide a distal-proximal compression gradient along the body part. Yet another object of the invention is to provide a therapeutic compression garment that allows the user to quickly adjust compression levels without having to remove the garment from the limb. Still another object of the invention is to provide a therapeutic compression garment that is easy to tighten when setting the compression. Another object of the invention is to provide a therapeutic compression garment that is constructed to match the contour of the limb. Yet another object of the invention is to provide a therapeutic compression garment that, depending on the materials, can be fabricated for short or long-term use. Still another object of the invention is to provide a therapeutic compression garment with a minimal number of bands for ease of application. Other objects, features, and advantages of the present invention will become more fully apparent from the following detailed description of preferred embodiments, the appended claims, and the accompanying drawings in which: DESCRIPTION OF THE DRAWINGS FIG. 1 is a view of the inner surface of a therapeutic compression garment of the present invention. FIG. 2 is a sectional view taken along line 2-2 of FIG. 1 looking in the direction of the arrows; FIG. 3 is a view of the inner surface of another embodiment of the therapeutic compression garment of the present invention; FIG. 4 is a sectional view taken along line 3-3 of FIG. 3 looking in the direction of the arrows; FIG. 5 is a view of the outer surface of another embodiment of the therapeutic compression garment of the present invention. FIG. 6 is a sectional view taken along line 4-4 and 5-5 of FIG. 5 when the bands are wrappingly engaged around the limb looking in the direction of the arrows; FIG. 7 is a sectional view taken along line 6-6 and 7-7 of FIG. 5 when the bands are wrappingly engaged around the limb looking in the direction of the arrows; FIG. 8 is a view of the inner surface of another embodiment of the therapeutic compression garment of the present invention. FIG. 9 is a view of the inner surface of another embodiment of the therapeutic compression garment of the present invention; FIG. 10 is a view of the inner surface of another embodiment of the therapeutic compression garment of the present invention; FIG. 11 is a perspective view of a garment similar to FIG. 5. FIG. 12 is a view of the inner surface of an embodiment of the device in which a slide fastener is positioned in the central region. FIG. 13 is an embodiment of the device which has a examples of compression measuring systems on the outer surface. FIG. 14 is a calibrated measuring card. FIG. 15 is an assemblage of the central region, lateral regions and bands shown in FIG. 8. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the invention is shown in FIG. 1. The garment 1 has a central region 10 which has an inner surface 2 and an outer surface 3 (FIG. 2). The central region 10 is formed from material which is flexible and substantially inelastic. Lateral margins 7, 8 are disposed respectively in lateral regions 5, 6 which extend laterally from the central region. In practice, the central region is wrapped partially around a user's limb. Extending from opposite lateral margins 7, 8 of the lateral regions 5, 6 are a plurality of bands (20-21, 22-23, 24-25, 26-27). Each band 15, which has an inner 9 and an outer surface, has a proximal edge 35 and a distal edge 40 and terminates in a distal region 45. The bands 15 are positioned for wrappingly or circumferentially engaging either with the opposite lateral region or with the edges and/or the surfaces of one or more bands extending from the opposite lateral margin. It should be understood that bands which extend from a lateral region, when wrapped circumferentially around the limb, engage surfaces and/or edges of one or more bands extending from the opposite lateral region. The term “opposing bands” refers to a set of bands which engage each other when wrapped. In some embodiments, a set of opposing bands comprise a pair of bands (FIG. 8). In other embodiments, a set of opposing bands comprises three bands, as shown in FIG. 9 in which, a set of opposing bands, when wrapped, involves bands 20 and 22 juxtaposingly engaged with band 23. In certain devices, bands extend from the lateral regions at independent angles with respect to the longitudinal axis of the central region. Accordingly, a device may comprise sets of opposing bands which all extend perpendicularly from the longitudinal axis, or all extend at non-normal angles; or any combination of normal and non-normal angles. Furthermore, the bands of a set of opposing bands may extend at angles independently of each other. Positioned on the distal region 45, integrally or detachably, of each band 15 is a fastener 75 which when circumferentially stretched about the limb detachably secures either to the outer or inner surface of a band extending from the opposite lateral margin, or to the outer or inner surface of the central region or lateral region 5 or 6 on the opposite side of the garment. In any case, a band 15, in wrapping engagement about the limb, detachably secures to an opposite lateral region and/or to an opposite band of the set of bands to which it belongs as it encircles the limb, drawing the first and second lateral regions toward each other, which tensions the central region, and thereby tensions the central region, thereby providing a tension in the garment that compresses the limb. In one mode of fabrication, the therapeutic compression garments shown in FIG. 1, FIG. 3, and FIG. 5 are made in one piece from a flexible, foldable hook and loop type fabric (e.g. Velcro(tm)) having an outer loop surface which is preferably a light weight loop fabric of the type designated Velcro 3610 or Velcro 3800, the former being substantially inelastic and the latter having a limited stretch at least in the vertical or longitudinal direction. Other suitable materials range from inelastic to those with some elasticity such as neoprene that has a small amount of elasticity especially in the longitudinal but also circumferential axis. The central region 10 is wrapped partially around the body part. Bands extending from a lateral region are connected to bands extending from the opposite lateral regions and, prior to wrapping around the limb, extend outwardly in opposite directions. The bands 15 are separated or defined by spaces 12 or by slits 13. As illustrated in FIG. 1, FIGS. 3 and 5, variation in the space between bands generates different amounts of overlap between sets of bands, which extend from opposite lateral regions, when applied to the body part. In FIGS. 1, 9 and 10, band 20 opposes band 21. Bands 21 and 23 oppose band 20. Band 23 is opposed by bands 20 and 22; band 22 is opposed by bands 23 and 25, and soon. In FIGS. 3 and 5, there are three sets of opposing bands: 20-21; 22-23; and 24-25. In FIG. 8, opposing bands are: 20-21; 22-23; 24-25; 26-27; 28-29; 30-31; 32-33. In FIG. 1, the bands 15 wrappingly engage by encircling the limb so as to fit into an opposite space 12. For example, band 20 is wrapped into space 12 between bands 21 and 23 so that the proximal edge of band 20 is in juxtaposition with the distal edge of band 21; and the distal edge of band 20 juxtaposes the proximal edge of band 23. Fasteners 75 made of hook material (such as that sold under the trademark Velcro) are attached to the unanchored ends, i.e. distal regions of the individual bands, and serve as means for detachably securing the band to loop-type material of the outer surface of the lateral region on the opposite side of the garment. The act of securing the distal regions of the bands to the opposite lateral regions serves to draw the first lateral region toward the second lateral region, which stretches the central region, thereby providing a tension in the garment that compresses the limb. The bands are spaced and their extension from the lateral region angled in a manner to accommodate opposing bands in crossing and overlapping relationship, and wherein hook and loop type hook surface are positioned at the ends of the inner surfaces of at least half of the bands, whereby opposing bands can be extended toward each other with each band overlapping another and tightened to apply the desired compression and the inner hook surfaces can be pressed against the outer loop surface to anchor the bands in a tightened condition. The width 36 of a band can be sized to account for the reduced surface area caused by necking that can occur when using an elastic material for the bands. When a band is stretched along it's longitudinal axis, the width of the band can narrow. For example, if the distal and/or proximal edges of overlapping bands are curved outward to compensate for necking, minimum overlap of bands occurs with this design but the body part or limb remains completely encompassed. Referring to FIG. 3, the bands may include areas of reduced width 31 created by a recess formed into a proximal 35 or distal edge 40 of the band. When wrapped around the body part, the recessed areas of opposing bands accommodate each other in register, allowing the bands to overlap without bunching. These reduced widths 31 are positioned and sized to create various standard circumference sizes (i.e. small, medium, large) of the therapeutic garment. The “sizes” of circumference preferably correspond to ranges of circumferences. Devices for different body parts would require different ranges. In alternative embodiments (all of the opposing bands in FIGS. 3, 5, and 8) some or all of the opposing bands are positioned to partially or completely overlap each other when wrappingly engaged. The inner surfaces at or near the distal ends 45 of the bands have hook-type surfaces 50 for detachable attachment to loop-type material positioned on the outer or inner surface of the opposing band or opposing lateral region. An embodiment with both opposing bands having Velcro-type hook surfaces and the bands completely overlapping would require one set being on the inner surface and the other on the outer, where one set would attach to an inner loop surface of the garment and the other would attach to an outer loop surface. (FIG. 7 and bottom 2 pairs of bands in FIG. 5). Pockets Compression devices according to the present invention require the tightening of bands to establish tension in the material of the device along a circumference of the body part or limb. This requires pulling or pushing on tabs attached to the free ends of bands, i.e. distal ends of bands. The user has to grasp the free ends or tabs with his or her fingers and pull or push, which requires adequate finger dexterity and strength. Persons suffering from a circulatory disorder and possibly some other disability may have some difficulty pulling or pushing with the force necessary to achieve a good compression and retain their grip on the free end or tab. Accordingly, the present invention provides a pocket 90 formed in the distal region of a band assisting the user to push or pull the free end of the band with his or her fingers. This pocket may be used with any of the compression devices shown and described in this specification. FIG. 5 shows the outer surface of a compression device according to the invention, such as that shown in FIG. 11. The band has a pocket sewn at a distal end of the band to serve as an aid when tightening the band. This is especially useful for persons who lack finger mobility, such as those persons suffering from arthritis, and cannot easily grasp bands between thumb and forefinger in order to pull on the band. The pocket helps the user to tighten a band in any compression device disclosed in this specification or, for that matter, any device or garment applied to the body. Embodiments include pockets positioned on one or a plurality of bands. In the embodiment shown in FIGS. 5 and 11, the pocket is made of a hook material on the pocket's outward face. The pocket is attached by sewing to a band along the pocket's three edges with the fourth edge open, creating a space into which a portion of the hand or one or more fingers can be inserted. FIG. 11 shows the pocket in use: the band 15 is wrapped around a body part L with one or more of the fingers of one hand being inserted in the pocket. The user can either push his or her fingers into the pocket 90 as shown in FIG. 11 or can hook his or her fingers into the pocket and pull (not shown) on the pocket to urge the distal region or end of the band in the desired direction. The end of the band with the pocket is tightened by pushing (or pulling) the fingers into the pocket and tucking the end 72 under the opposite end 77 of the band. At the same time, the opposite end 77 is pulled tight and wrapped over the pocket. The hook material of the pocket will help anchor the pocket to the inside face of the outer and opposite end of the band. A fastener, made of a hook material, is used to secure the end to the loop material of the outside surface of the band. In another embodiment of the invention (not shown), the pocket can be made of a non-hook material, and the inward pressure of the band can be sufficient to anchor the end in place. As the hand is pulled out and away from the pocket, the opposing band end is brought down and attached to the outer surface of the band with a pocket using the fastener. Opposing bands ends may be equipped with a pocket 90 that assists the user in tightening the garment and attaching the opposing band's hook surface to the outer surface of the garment. The garment is removed by separating the hook surfaces from the outer loop surfaces. To facilitate handling the fabric during application to the body part and to prevent wrinkling of the fabric or slippage of the proximal (upper) end of the garment relative to the distal (lower) end, the fabric can be stiffened or reinforced longitudinally, such as by a strip, rod or other suitable means. In the therapeutic garment shown in FIG. 1 such reinforcement is provided by a longitudinal band 55 of Velcro-type fabric having an inner hook surface 60, which adheres to the outer loop surface 65 of the garment. The strip can be made of a high shear hook tape, such as Velcro P87 affixed along the vertical center line 70, i.e. longitudinal axis of the central region 10 of the garment to stiffen it and prevent wrinkling of the garment. See FIG. 2. The therapeutic garment of this invention does not have to be custom-made to the body part because the fabric readily conforms to the body contour due to its inherent characteristics, such as light weight, flexibility and foldability, in contrast to heavier, thicker and more rigid materials used in the therapeutic device described in U.S. Pat. No. 4,215,687. In the therapeutic garment of the present invention, overlap of the bands is tolerated and is the basis of eliminating gaps and spaces in the compression applied to the body part. Neoprene fabric is particularly advantageous in that stretch characteristics permit it to shape, mold, and conform to the body, while applying a near inelastic compression to the body part due to the fact that in tightening the bands the stretch limits are reached before the desired compression levels are achieved. The fabric can be oriented in the garment such that the greater stretch is in the longitudinal or vertical direction of the garment and the lesser stretch is in the transverse or horizontal direction of the garment. A preferred material for the garment is neoprene sheeting, such as that available from Perfectex Plus, Inc. of Huntington Beach, Calif. The advantages of neoprene are that it is thin, is available in wide sheets that have a moderate amount of stretch in one or both dimensions, retains its resiliency throughout repeated use, and is available laminated to other materials. For example a VELCRO-type loop material may be laminated on the surface of the neoprene to protect the neoprene, improve the comfort of wear, and provide a surface that will engage with hook materials. Other materials can also be used for this application, including laminates that use breathable open-cell foam instead of neoprene, provided they have the important properties described above. The therapeutic compression garment shown in FIG. 1 can be made from an elastic fabric or an inelastic Velcro-loop type fabric or combination of both. Preferred embodiments have elastic bands and an inelastic central region. Any combination of elastic and inelastic materials that provides user comfort, conformance to the most curved portions of the limb, and ease of construction finds use in the invention. In certain embodiments, the central region 10 is wider proximally than distally to accommodate the larger circumference of proximal limb segments. The opposing limb compression bands are longer proximally than the limb compression bands distally located. In FIGS. 1, 9, and 10, the opposing limb compression bands are separated from adjacent bands by spaces 12, wherein an oppositely situated band mates or fits with one or more opposite bands when it is wrappingly extended from the opposite lateral region. The bands may be angled relative to a proximal-distal longitudinal axis to completely encompass the limb with minimum overlap of the bands. The garment can be shortened longitudinally by cutting off upper or lower bands, one band at a time, horizontally to the opposing edge of the garment. The bands can also have varying widths 36, as can the length of the bands to accommodate any necking that occurs when elastic is being stretched. This can also be accounted for in sizing of spaces 12 in accompanying opposing bands. These spaces increase in width while the straps decrease in width while applying garment due to the characteristics of the semi-elastic material. In FIG. 3, the therapeutic compression garment is made from an elastic fabric or an inelastic Velcro-loop type fabric or combination of both. The garment has a central region 10 for wrapping partially around the body part and a plurality of bands 15 connected to lateral regions 5, 6 of the central region and extending outwardly in opposite directions from lateral regions to encompass the body part. The bands 15 are defined by slits 13. Reduced band widths 31 are provided so that they register when wrappingly extended to accommodate the opposite band in a crossed overlapped relationship. Velcro-hook type surfaces 75 are carried at the ends or near the ends on the inner surfaces of each of the distal regions 80 of the bands. The therapeutic compression garment of FIG. 5 can be made from an elastic Neoprene fabric or an inelastic Velcro-loop type fabric or combination of both. The garment has a central region 10 for wrapping partially around the body part and a plurality of bands 15 connected to the lateral regions of the central region and extending outwardly in opposite directions from to encompass the body part. The bands 15 are defined by slits 13 which are arranged generally perpendicular to the longitudinal axis 70 of the garment. The bands are arranged in a opposing paired relationship so that when wrappingly applied, one band of a pair completely overlaps the other. Velcro-hook type surfaces 75 are carried at the ends or near the ends on the inner surfaces of a distal region of one of the bands in each pair. In one embodiment, an opposite band in each pair may include a pocket 90 at or near the end of a distal region on the outer surface of the band. The user inserts fingers into the pocket to keep tension on the band while overlapping the other band of the pair and securing it to the outer loop surface 95 of the garment as shown in FIG. 6 and FIG. 11. FIG. 11 shows the pocket 90 in use. With fingers inserted into the pocket, the user wraps the band around body part L. The user can either push their fingers into the pocket 90 as shown in FIG. 11 or can hook their fingers into the pocket 90 and pull (not shown) on the pocket to urge the distal end 80 of the band in the desired direction. The distal end 80 of the band with the pocket is tightened by pushing (or pulling) the fingers into the pocket and tucking the end under the opposite distal end 100 of the band. At the same time the opposite distal end 100 is pulled tight and wrapped over the pocket. The pocket 90 can be made of hook and loop type hook material to help anchor the pocket to the inside of the outer opposite end of the band. A fastener 75 made of hook and loop type hook material is used to secure the end to the loop material of the outside surface 95 of the band. In addition to the pocket embodiment, there can be a Velcro-hook type fabric 75 to add additional support in securing the overlapped bands. The Velcro-hook type loop surfaces 75 would be positioned at or near the distal end of the band on the outer surface of a band opposing a band with a Velcro-hook type surface on the inner surface. When engaged, the Velcro-hook type surface of one band will attach to either the inner or outer loop surface of the opposing band as shown in FIG. 7. The therapeutic compression garment of FIG. 8 (an exploded view) has a central region 10 made of a semi-elastic material such as neoprene and essentially inelastic bands 15 that can be made of a unitary piece of fabric with slits 13 defining the bands. The bands can also each be made separately. In either case the bands are attached to the lateral regions 7, 8 of the central region along the curved edges 110 which aid the garment in conforming to the limb shape, or can be attached using a hook and loop type material to the curved edges of the lateral regions of the central region 10. The edges of the lateral regions are cut to a curve that depends on the shape and size of the body part the garment is to fit. The bands are arranged in opposite paired relationship. Each of the bands has a region of reduced width 205 formed by recesses 37 in a proximal or distal edge of the band. The reduced width region is formed by material removal from one or both of the proximal and distal edges of the bands, for example from the proximal or upper edge of one member of the pair, and the distal or lower edge of the other. Accordingly, the bands can overlap and lay on top of each other without causing any increase in width at the point of crossing. Velcro-hook type surfaces are attached at or near the ends of the bands and are used to removably fasten the bands to loop type loop material positioned on a surface of the opposite band. Compression Measuring System. The garment may also be equipped with a compression measuring system that utilizes the elasticity of the material to measure the amount of applied compression to ensure the garment is applied with gradient compression on the limb. Guidance for structuring and using a system for measuring compression applied to a body part by a compression garment is disclosed in U.S. Pat. No. 6,338,723, herein incorporated by reference. One preferred embodiment of the compression device according to the invention provides a garment such as in FIG. 13 and a calibrated measuring scale or card (FIG. 14) that is used in combination with the bands to measure the stretch of elastic in the bands. A portion of each band 100 is elastic or substantially elastic along the band's length or longitudinal axis, which is the axis along which tension is to be applied. Each band 100 could be made, of course, so that it is elastic along only a part of its length. Each band 100 has indicia 101 printed along its elastic length spaced by intervals 102. The interval 102 has a fixed or specified length when the band is not under tension, as in FIG. 13. In the compression device shown in FIG. 13, the indicia can be two or more tick marks 101 spaced along the length of the band at intervals 102. Other embodiments of the indicia 101 could include dots, geometric shapes, symbols, patterns, text, or any other pattern spaced at intervals 102 along the elastic axis of the band 100 for measurement with a calibrated scale or card (as discussed below) upon application of the band or bands 100 to the body part and stretching of the band or bands 100. The intervals 101 are preferably at a uniform or specified distance from each other when the bands 100 are relaxed and not under tension, as shown in FIG. 13. In an alternative embodiment, also shown in FIG. 13, the indicia 125 are two or more parallel lines spanning the length of the garment and spaced at intervals 126. These lines are on a portion 127 of the garment that is elastic along the entire length of the garment. The measurement of elastic stretch or deformation along the elastic axis (depending upon the specific form of the embodiment), upon application of the garment in FIG. 13 to the body part, serves to accurately measure compression of the underlying body part. The interval 102 or 126 between successive indicia 101 or 125 will increase when the band 100 is tensioned and the elastic material of the band lengthens under tension. The user measures the distance between successive ones of the indicia 101 or 125 after application of the device to the body part. This distance is indicative of the tension in the elastic material of that part of the garment and, when the circumference of the body part is known, the compression applied by the device. In the embodiment shown in FIG. 13, fasteners 103 made of hook material are attached to the ends of the bands 100. The bands 100 are wrapped around a body part, and the ends are held in place using the fasteners 103. After the user measures the circumference of the body part, a scale or card (FIG. 14) is used to determine the compression of the body part. As described below, the card is used to establish or verify equal or varying tension at different location on the garment as necessary. As an example, the natural distal-to-proximal increase of circumference of a body part such as a limb automatically yields a gradient of compression running up the limb for equal measured tension, without the user having to set a different target compression for different positions on the limb. The compression device in FIG. 13 requires the use of means for measuring the distance 102, 126 between the indicia and means for correlating that distance to the amount of tension and/or, if the circumference of the body part is known, to the amount of compression of the body part surrounded by that portion of the garment. U.S. Pat. No. 6,338,723 (incorporated by reference), describes the structure and use of a card (see FIG. 14) having a plurality of edges with measurement scales for measuring the distance between the indicia 102 or 125 and means for correlating that distance to the amount of tension and/or, if the circumference of the body part is known, to the amount of compression of the body part surrounded by that portion of the garment. Indicia shown in FIGS. 13 and 14 correspond to units of actual compression values. Indicia could also correspond to units of force or arbitrary units enabling relative compression levels to be set. In use, the band or bands 100 are applied directly around a body part or around other material that surrounds a body part. Tension on the bands 100 causes the elastic component of the device to stretch, increasing the intervals 102 or 126 between successive indicia 101 or 125. If the circumference of the body part under that portion of the garment is known, measuring the interval 102 or 126 of the indicia 101 or 125 provides a measure of compression under the garment at that point. Compression devices according to the present invention include embodiments that do not require the use of a card or other such separate device in order to measure the compression. The means for measuring the stretch of the elastic component of a compression device and the means for correlating the stretch of the device to the compression that it provides are markings applied directly to the band, sleeve or garment of the compression device. The device itself therefore is used to measure the amount of compression that is provided to the limb or other body part. FIG. 13 also depicts a compression device in which a portion of each band 200 is elastic or substantially elastic along at least a portion of its length. A fastener 203 is sewn to the end of the band and is preferably made of a hook material that will removeably attach to the loop material of the garment. Compression measurement indicia 201 are printed on a central region or lateral region of the exterior of the garment. In this embodiment the indicia 201 each consist of one or more scales. Each scale is to be used for a specific circumference of the limb or body part that is to be compressed by the band 200. (Alternatively, each scale could be used for a particular compression that is to be achieved and the individual markings correspond to different circumferences, although this variation is not shown. Each scale 201 has a circumference marker 205 stating the circumference for which the scale 201 is calibrated. The circumference marker 205 is located at a distance from the edge or other specified portion of the band end, in a circumferential direction with respect to the body part that is equal to that circumference when the band 200 is not under tension. A series of marks 206 corresponds to various non-zero compression levels. The circumference marker 205 is also the zero compression mark for that circumference. The band 200 is wrapped around the body part and the fastener 203 attaches the end 207 to the outer surface of the central region in the vicinity of the indicia 201. The user observes where the end 207 or other specified portion of the band 200 falls on the central region and thus which indicia 201 are contacted by the band end 207. If the circumference of the body part is known, the compression under the band 200 is easily determined by identifying the compression marking 206 associated with the scale for the circumference 205 that is closest to the measured circumference. The circumference can be either measured beforehand with a tape measure or similar device, or can be measured by the garment itself, by first wrapping the band 200 loosely around the limb without tension, and observing on which circumference marker 205 the band end 207 falls. The position of the edge or other specified portion of the band 200 (and thus the marking it reaches) is a measure of the stretch of the band 200 and thus the tension it experiences. The tension is converted to compression by consideration of the circumference, the amount of overlap, and so forth as described in connection with the card shown in FIG. 14 (U.S. Pat. No. 6,338,723, herein incorporated by reference). The indicia 201 could consist of pressure and/or circumference measurements themselves, or simplified indicators that could be referenced to a table that would give the compression based on the measured circumference of a body part and the indicator read from the band 200. The therapeutic compression garment of FIG. 9 consists of a central region 10 made of an inelastic material and bands 15 made from a unitary piece of semi-elastic material with the spaces 12 defining the bands. Assembling the curved edges in the 110 aids the garment in conforming to the limb shape while, combined with the slight elasticity of the garment, prevents wrinkling and slippage of the proximal end of the garment relative to the distal end when applied to the body part. The elastic bands 15 may also be equipped with a measuring system that utilizes the elasticity of the material to measure the amount of applied compression to ensure the garment is applied with gradient compression on the limb. Velcro-hook type surfaces are attached at or near the ends of the bands and are used to removably fasten the bands to the outside hook and loop type loop material of the garment to apply the desired compression. The therapeutic compression garment of FIG. 10 consists of a central region 10 made from multiple pieces of non-elastic material attached at curved edges 110 to create a central region that accommodates the limb shape. The pieces are stitched together (or otherwise assembled) in such a way as to form a central region with bands stitched or otherwise attached to the lateral regions of the central region. Those of skill in the art will understand that ways of joining multiple pieces of non-elastic material might be employed in place of stitching. Darts may be cut into a single piece of fabric to create a central region that accommodates the limb shape. Darts or seams are sewn into the central region enable the garment to conform to the bent shape of an arm at the elbow, the leg at the knee, or another jointed body part. Also, by varying the width of the central region, the garment would be formed to taper, or otherwise vary in circumference, in order to conform to the shape of the body part. FIG. 8 shows a flat sheet of inelastic loop material with curved edges cut into it. FIG. 15 shows the assembly of the sheet into a central region 10. The darts 34 are closed by sewing the curved edges together, creating a bend or limb-accommodating contour in the finished garment so that when the lateral regions are wrapped around and towards each other, the central and lateral regions are biased into a three-dimensional curvature in order to fit the body part. The present invention provides a further advantage of allowing the user to easily and rapidly adjust desired compression by adjusting the bands of garment as described above. In some forms of the present invention adjustment of the compression levels occurs at different portions of the limb longitudinally at the same time lending to an even faster adjustment time. Longitudinal Slide Fastener Section Embodiments of the garment are equipped in the central region with a longitudinally extending slide fastener (FIG. 12) with which to separate portions of the central region. U.S. Pat. No. 6,109,267 (incorporated herein by reference) relates to a therapeutic compression device which includes a longitudinally extending splicing band or slide fastener which facilitates quick and easy removal of the device from the body or limb and quick and easy reapplication to the body or limb without the necessity of unthreading the adjusted compression bands. The longitudinal slide fastener provides the wearer quick removal and quick reapplication of the garment without detaching the bands which apply the desired compression. A longitudinally extending slide fastener or zipper 120 extends at least the length of the central region 10 of the garment to facilitate removal and reapplication of the garment without unfastening the bands. In the therapeutic compression device shown in FIG. 12 for use on a leg, the runner 121 closes the slide fastener during its longitudinal movement from the upper end of the garment to the lower end of the garment and opens the slide fastener during its upward return movement. When the garment is applied to an arm, the direction of the closure of the runner 121 is reversed because starting the zipper closure requires both hands, and it would be virtually impossible to attach and start the zipper at the top of the arm. In the preferred embodiment of the therapeutic compression garment shown in FIG. 12, the slide fastener extends at the upper end of the garment beyond the upper end of the garment to permit separation of the central region along its entire length while the separated portions of the central region remain connected by the extreme end of the extended portion of the slide fastener. The extended portion 122 shown in FIG. 12 permits the runner 121 to slide upwardly to open the slide fastener beyond the upper edge of the central region of the garment to facilitate removal of the garment from the body part and reapplication thereof. In this way, the garment can be removed and replaced by loosening and without unthreading the compression bands. The upward movement of the slide 121 is limited so that the separated portions of the central region of the garment remain connected by the end of the extended portion of the slide fastener. The extension 122 has a strip of hook tape 123 along each of its outer cloth edges to hold it against the outer loop surface of the garment in its folded down position. A flap (not shown) may be provided to cover the slide fastener and the folded down zipper extension 122. If provided, the strips 123 of hook tape can be omitted. In the alternative, the outer surface of the flap can be provided with a Velcro-type loop surface and the extension and the hook surface strips can be folded over the flap and adhered thereto. The flap would also provide stiffening and wrinkling resistance which can be increased through the addition of a longitudinally extending rod 124 of stiff, flexible material (e.g. rubber). The therapeutic compression garment shown in FIG. 12 equipped with a longitudinally extending stiffening rod and longitudinally extending slide fastener would preferably be worn such that the stiffening rod and slide fastener are located on the inside or outside of a limb to facilitate opening and closing the slide fastener and to prevent the stiffening rod from interfering with the bending of the knee or elbow. In this way, the stiffening rod flexes with the bending of the knee or elbow without undue wrinkling or distortion of the garment. The garment also may include portions or a complete fabrication of a neoprene-type semi-elastic fabric for a smoother fit with better distribution of the applied compression. The garment may also consist of uniquely shaped pieces and seams, well known to those in the art of tailoring, such as but not restricted to darts, to better conform to the limb and better distribute the applied compression. Certain embodiments of the garment are formed from a flexible laminate material which has an inner padded layer of foam for comfort and an outer layer of hook and loop type material. Because of the ease of use and comfort of the garment, the invention provides the advantage of greater patient compliance. Therapeutic Use In therapeutic use, a method of the invention involves treating medical disorders, which require compression therapy. The method involves the step of applying to an indicated body part a garment of the invention whereby a compressive force or support is applied to the body part, such as the arm, foot, ankle, and leg on subjects (human or animal) suffering from disorders that require compression therapy. Such disorders include, but are not limited to, lymphedema, phlebitis, varicose veins, post-burn treatment, post-fracture and injury (including sports injury such as a pulled muscle) edema, stasis ulcers, obesity and circulatory disorders requiring application of compression devices. Because human skin is elastic in nature, when such systems as the lymphatic or venous return systems fail to function properly, the limb or body part accumulates fluid and stretches to accommodate edema. Under normal operation, those systems would allow that fluid to circulate and not collect in those limbs or body parts and the skin would normally accommodate only the subtle changes by expanding or contracting. Use of non-elastic or substantially non-elastic compression garments of the present invention aid's the skin's strength, not allowing it to stretch and accumulate fluid. The fluid must then flow through the system from the compressive force of the non-elastic or substantially non-elastic compression device. In addition, when a limb or body part is affected by poor circulation, the stagnated or poorly circulated fluid can manifest itself as ulcers. Use of compressive devices aids in that circulation. However, areas on such body parts or limbs at or near joints or concavities presents an obstacle to applying compressive devices because of the difficulties in applying and sustaining a uniform or gradient compression. The present invention overcomes this obstacles, in particular, by various embodiments which incorporate darts. The invention has been shown in preferred forms and by way of example, and many variations and modifications can be made therein within the spirit of the invention. The invention, therefore, is not intended to be limited to any specified form or embodiment, except in so far as such limitations are expressly set forth in the claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>This invention relates to devices for applying compression to parts of the body for therapeutic reasons. Compression applied to a body part, such as a limb, is essential for resolving many circulatory disorders. The application of compression at the appropriate level has therapeutic benefits. For example, it restores circulation, relieves swelling, treats pain, heals ulcers, and treats varicose veins. Elastic and inelastic garments have been employed in compression therapy of the limbs. Most of these garments suffer various degrees of shortcomings, particularly discomfort, loss of compression, difficulties in application and removal, lack of adjustability, and ineffectiveness. A desirable trait of compression devices is that they provide to the limb compression levels that are dynamic, fluctuating in response to short-term changes inside the body part. Compression requirements change as internal pressures change, depending on whether the patient is upright or prone. Furthermore, the movement of fluid out of a body part is facilitated by the pumping effect caused by fluctuations in pressures. Such pressure fluctuations can be enhanced by compression devices that resist changes in limb size, such as those that occur during muscle flexion. Patients have observed that stockings, wraps, and bandaging systems made entirely of elastic materials are uncomfortable. Fully elastic devices deliver an unchanging level of pressure, which alternately feels either “too tight” or “too loose” to the patient depending on the patient's position. These elastic systems also do not resist small changes in limb circumference, and hence do not provide the fluctuating pressures that are needed to assist with pumping fluid out of the body part. To be effective, compression devices need to maintain appropriate compression over time. Large changes can occur in limb volume, reflecting either diurnal fluctuations or progressive changes in the degree of swelling. Devices that provide compression through the wrapping of materials with limited elasticity, such as with the Unna's boot, cannot accommodate such changes in limb volume. For example, they may initially provide appropriate compression, which is dynamic in response to internal changes, but after hours of use the movement of fluid out of the limb will result in an overall loss of pressure. And because these systems are wrapped around the limb in layers, it is not practical to periodically remove and re-apply the wrapping at the appropriate compression level. In the case of more elastic systems, such as long-stretch bandages and elastic stockings, the greater elasticity helps them to sustain consistent compression levels over time. However, if changes in limb volume are great enough, pressures under the devices can go outside the appropriate therapeutic range. An additional problem with elastic stockings is that if they are sized incorrectly, or if the body part is of an irregular shape, the pressure could be incorrect under all or part of the garment from the onset. In the case of elastic bandages, it is easy to apply the layers at too high or low of a pressure, requiring a time-consuming removal and re-application. A useful trait of compression garments is that they be easy to apply and adjust. This helps to ensure appropriate, sustained compression levels by allowing the user to adjust to accommodate changes in limb volume, and enabling the garment to be adjusted to an exact fit regardless of limb shape. Being easy to apply also increases the likelihood that the patient will continue to use the device and obtain its therapeutic benefits. Stockings can not be adjusted and are difficult to slide onto the limb. Bandaging systems can not be adjusted without being removed completely, and require skill for proper application. Devices such as described in U.S. Pat. No. 5,653,244 are primarily inelastic, and can be adjusted through series of interlocking bands. As such they provide dynamic compression that can be sustained over time. However, because they are primarily inelastic, compression levels quickly go down with changes in volume, so sustaining compression requires frequent re-adjustment of the bands. Another consequence of being primarily inelastic is that it is more difficult to hold force in the bands while applying, and as a consequence, more effort is required by the user during application—either in the form of greater force, or the use of a greater number of bands on the garment. Furthermore, because the pairs of bands interlock—one member of a pair of bands passes through a hole in the other member—they require a certain amount of manual dexterity to apply. This is particularly disadvantageous, as many users are older or have other limitations of mobility. Compression devices are therefore needed that are easy to apply, and that provide compression that is both sustained (in that significant long-term changes in limb volume can be accommodated), and dynamic (such that short-term changes to internal pressure can be countered). To this end, compression devices are needed that provide the ability to apply and adjust compression as quickly and easily as possible. Compression devices are also needed that are inelastic enough to provide compression levels that respond dynamically to changes in patients' compression requirements, while still being elastic enough so that the device does not readily loose appropriate compression. A need also exists for compression devices that can be applied to parts of the body that have varying circumference and that are comfortable to wear throughout the day and in different postures. Sustained yet dynamic compression is key to proper treatment. It is often a problem with compression devices that the applied compression goes down over time or with changes in limb volume. It is often a problem with other devices that in order to sustain compression, the device must be so elastic that compression levels do not fluctuate with changes in patient need. Providing compression that has a low but significant level of elasticity, and having a means of easily adjusting compression levels, enables sustained and dynamic compression levels to be maintained. U.S. Pat. No. 3,845,769 relates to a boot having a split sleeve of essentially unyielding material shaped to fit a leg. The sleeve is held in position and compression is applied by a plurality of bands of interlocking fabric material, such as Velcro or Scotchmate. U.S. Pat. No. 4,215,687 relates to a combination or kit, which permits the in situ construction and assembly of a therapeutic compression device directly on the patient by a doctor or other skilled person. The combination or kit includes a Velcro-type anchoring tape having an interlocking fabric material on one side and a plurality of body or limb encircling Velcro-type bands which are assembled, one by one, in edge-to-edge relationship either by direct contact with the anchoring tape or by indirect contact through Velcro-type splicing means. These custom-made therapeutic compression devices have achieved wide recognition in healing leg ulcers and in the treatment of lymph edema. On the other hand, the custom construction which requires splicing of the body or limb encircling bands when they are too long and when the portion of the body or limb is contoured is a tedious and time consuming task. U.S. Pat. No. 5,120,300 relates to a compression band for use in the therapeutic device disclosed in U.S. Pat. No. 4,215,687 and, more particularly, to a compression band for quick and easy application to and removal from a body part. U.S. Pat. No. 5,254,122 relates to a therapeutic compression device of the type disclosed in U.S. Pat. No. 4,215,687 which includes a longitudinally extending splicing band or slide fastener which facilitates quick and easy removal of the device from the body or limb and quick and easy reapplication to the body or limb without the necessity of unthreading the adjusted compression bands. U.S. Pat. No. 5,653,244 relates to a therapeutic compression garment made of flexible, foldable, light weight Velcro-type loop fabric having a central region for wrapping partially around a body part and a plurality of pairs of bands integrally connected to the central region and extending outwardly in opposite directions from both sides of the central region to encompass the body part. One of the bands of each pair has a slot to accommodate the opposite band in threaded, folded relationship. U.S. Pat. Nos. 5,918,602 and 5,906,206 relate to the therapeutic garment disclosed in U.S. Pat. No. 5,653,244 and adapted for the leg in combination with an ankle-foot wrap for applying therapeutic compression to the leg, ankle and foot. U.S. Pat. No. 6,338,723 relates to a device for compression of objects such as parts of the body. The device has the form of a band sized to encircle the compressible object and having a component or components made of an elastic material. Indicia are printed on the device such that the stretch of the elastic material as the device is tensioned around the body part causes increased separation of the indicia or movement of a free end of the band with respect to the indicia. A system measures the separation of the indicia and converts it to compression as a function of the circumference of the body part. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention is a garment for applying compression to a limb. The garment, which has inner and outer surfaces, comprises a central region of substantially inelastic material. Lateral regions are disposed on opposite sides of the central region. A plurality of bands extends from the opposite lateral regions. Each band comprises a distal region, proximal and distal edges, inner and outer surfaces, and a fastener for detachably securing the distal region to a band extending from the opposite lateral region or to the opposite lateral or central region. In use, the user encircles the limb, the inner surface of the garment placed against the limb, and draws the first lateral region toward the second longitudinal edge to stretch the central region and thereby provide a tension in the garment that will compress the limb. Preferred embodiments of the garment involve the central and lateral regions which are biased into a three-dimensional curvature in order to fit the body part. Various embodiments are provided in which the opposing bands extend either substantially perpendicular to a longitudinal axis of the central region, and the proximal and distal edges are substantially parallel to each other; or the bands extend from a lateral region at an angle with respect to a longitudinal axis of the central region; or combinations thereof. For example, an embodiment provides at least one set of opposing bands extends substantially perpendicular to a longitudinal axis of said central region, and at least one set of opposing bands extends at a non-normal angle to the longitudinal axis of the central region. Still other embodiments provide bands in which recesses are formed in either the proximal or distal edges of the bands to facilitate wrapping engagement by juxtaposition of the proximal and distal recessional edges of opposing bands. Other embodiments provide garments which bear an indicia system for measuring the compression which the garment applies to the limb. A preferred embodiment provides a card having a scale for measuring the separation of the position of the at least one indicia from the reference position. Reading the card in relation to the indicia system indicates the compression level for the pre-measured circumference of the body part, thereby permitting the user to determine the actual compression provided by the garment and to adjust the compression provided by the garment accordingly. The garment has an embodiment which comprises a pocket attached adjacent the distal end of a band. The pocket is sized to admit at least one finger inserted through an opening in the pocket that faces in a direction substantially away from the distal end of the band. The user can urge the end of the band around the body part by inserting at least one finger through the opening into the compartment of the pocket and pushing or pulling with the at least one finger toward the opposite side of the garment. In another aspect, the invention provides a method for applying therapeutic compression to a body part for treating a medical disorder which requires compression therapy. The method involves the step of applying with sufficient pressure to said body part a garment of the invention for a sufficient period of time to mitigate swelling in the limb. The method is suitable for treating medical disorders such as lymphedema, phlebitis, varicose veins, stasis ulcers, obesity, circulatory disorders; and for treating swelling due to traumas such as post-fracture edema, injury edema, and post-burn therapy. | 20040227 | 20080212 | 20050901 | 62580.0 | 1 | PATEL, TARLA R | LIMB ENCIRCLING THERAPEUTIC COMPRESSION DEVICE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,789,448 | ACCEPTED | Method and apparatus for keyhole video frame transmission during a communication session | A method and apparatus allows keyhole frame images to be transmitted to a receiving terminal during a communication session. The keyhole frame is movable and resizable throughout the display of the hosting terminal, whereby the image captured by the keyhole frame is transmitted to the receiving terminal during the communication session. The transmitted image may be combined at the receiving terminal with voice or other transmissions from other independent sources to form an integrated communication session. Modifications to the image may be directed by the receiving terminal either through voice commands sent to the hosting terminal from the receiving terminal, or alternatively through cursor/pointing device commands actuated from the receiving terminal itself. All modifications effected on the keyhole frame image at the hosting terminal are viewed in real time at the receiving terminal. | 1. A method of exchanging data between participants of a communication session, comprising: establishing a voice connection between participants of the communication session; activating a keyhole frame within a display of a hosting terminal that is in proximity to a first participant; establishing a stream connection between the first participant and a second participant; streaming image data contained within the keyhole frame from the hosting terminal to a mobile terminal proximately located to the second participant via the stream connection; and establishing data connections between ones of the participants of the communication session and the mobile terminal. 2. The method according to claim 1, wherein activating the keyhole frame comprises defining an area within the display of the hosting terminal to represent the keyhole frame. 3. The method according to claim 2, wherein activating the keyhole frame further comprises positioning the keyhole frame within length and width constraints of the display of the hosting terminal. 4. The method according to claim 3, wherein positioning the keyhole frame comprises centering the keyhole frame around an active cursor of the hosting terminal. 5. The method according to claim 3, further comprising modifying the keyhole frame after activation of the keyhole frame. 6. The method according to claim 5, wherein modifying the keyhole frame comprises issuing modification commands from the mobile terminal to change the contents of the keyhole frame. 7. The method according to claim 6, wherein issuing modification commands comprises sending verbal commands from the second participant to the first participant via the voice connection, wherein the first participant modifies the keyhole frame in response to the verbal commands. 8. The method according to claim 6, wherein issuing modification commands comprises sending cursor control commands from the mobile terminal to the hosting terminal, wherein the first participant has previously granted modification rights to the second participant. 9. The method according to claim 5, wherein modifications made to the contents of the keyhole frame are reflected in the image data streamed from the hosting terminal to the mobile terminal. 10. A keyhole frame processing system, comprising: first and second mobile terminals wirelessly adapted to establish a voice connection between them; and a hardware platform wirelessly coupled to the second mobile terminal and adapted to establish a data connection between the second mobile terminal and the hardware platform, the hardware platform comprising: a display; and a keyhole frame application adapted to place a keyhole frame anywhere within a viewable area of the display and further adapted to transmit image data contained within the keyhole frame to the second mobile terminal via the data connection. 11. The keyhole frame processing system according to claim 10, wherein the second mobile terminal transmits edit commands to the hardware platform affecting the image data contained within the keyhole frame. 12. The keyhole frame processing system according to claim 11, wherein the edit commands comprise voice commands transmitted from the second mobile terminal to the first mobile terminal via the voice connection. 13. The keyhole frame processing system according to claim 11, wherein the edit commands comprise cursor commands transmitted from the second mobile terminal to the hardware platform via the data connection. 14. The keyhole frame processing system according to claim 10, wherein the image data is reflected to a display of the second mobile terminal. 15. The keyhole frame processing system according to claim 11, wherein the image data affected by the edit commands is reflected to a display of the second mobile terminal. 16. A mobile terminal capable of being wirelessly coupled to a network which includes a hardware platform capable of transmitting video content to the mobile terminal, the mobile terminal comprising: a memory capable of storing at least a keyhole frame module; a processor coupled to the memory and configured by the keyhole frame module to enable projection of the video content to a display of the mobile terminal; and a transceiver configured to facilitate the image exchange with the hardware platform, wherein the keyhole frame module is further adapted to generate edit commands to change the video content displayed by the mobile terminal. 17. The mobile terminal according to claim 16, wherein the transceiver is further configured to transmit the edit commands over a voice channel. 18. The mobile terminal according to claim 16, wherein the transceiver is further configured to transmit the edit commands over a data channel. 19. A computer-readable medium having instructions stored thereon which are executable by a mobile terminal for exchanging video content with a hardware platform by performing steps comprising: establishing a first connection with a second mobile terminal to provide voice communications between the mobile terminal and the second mobile terminal; establishing a second connection with the hardware platform; receiving video data from the hardware platform via the second connection; and providing commands to the hardware platform that affect the video data received from the hardware platform, wherein the commands are provided via one of the first connection or second connection. 20. A hardware platform, comprising: means for establishing first and second connections with a mobile terminal; means for exchanging voice communications with the mobile terminal via the first connection; means for generating video data contained within a keyhole frame, the keyhole frame being defined by keyhole frame parameters to lie within a display region of the hardware platform; and means for providing the video data to the mobile terminal via the second connection. 21. The hardware platform according to claim 20, further comprising means for receiving commands to change the keyhole frame parameters. 22. The hardware platform according to claim 21, wherein the keyhole frame parameters includes a position of an active cursor within the display region of the hardware platform, wherein the keyhole frame is centered around the position of the active cursor. 23. A computer-readable medium having instructions stored thereon which are executable by a hardware platform by performing steps comprising: establishing first and second connections with a mobile terminal; exchanging voice communications with the mobile terminal via the first connection; generating video data contained within a keyhole frame, the keyhole frame being defined by keyhole frame parameters to lie within a display region of the hardware platform; and providing the video data to the mobile terminal via the second connection, wherein external commands are received that change the keyhole frame parameters. | FIELD OF THE INVENTION This invention relates in general to communication sessions, and more particularly, to rich call communication sessions offering keyhole frame image exchange between the communication session participants. BACKGROUND OF THE INVENTION Over the last decade, there has been a merger of two of the most successful communications tools ever developed—mobile communications and the Internet. The Internet has provided access to many kinds of services, information, and content through one common interface. Mobile communications has provided the concept of being reachable at any time and with the ability to reach other people or services quickly. Combining the freedom of the Internet with the reachability and immediacy of mobile networks, the Mobile Internet has been born. Service creation for the Mobile Internet is based on an open content format, e.g., eXtensible Markup Language (XML), and Internet Engineering Task Force (IETF) defined protocols, such as the Session Initiation Protocol (SIP). Service mobility through open content format provides accessibility of a consumer's personalized services through any access network or device, whereby service reachability through the open content format provides services that follow the consumer wherever he or she may go. While services such as messaging and browsing continue to be important to today's Mobile Internet user, person to person communications will remain as one of the most important services offered by the Mobile Internet. As the Mobile Internet technology advances, communications will combine multiple media types and communication methods with presence and community information, not only to enhance person to person communication, but also to enhance multi-point to multi-point communication, i.e., conferencing. With the use of Internet Protocol (IP), for example, addition of rich media is facilitated through the use of standardized networking and signaling protocols. A media enhanced call, i.e., rich call, may be defined as a voice or video conversation that is supported with concurrent access to an image, data, or other information during a single session. SIP will provide enabling technology for rich calls, where the Web and Mobile domains may be joined for true service mobility and access independence. SIP's support for rich calls will add “see what I see”, or “keyhole” capability for consumers through a combination of voice, mail, Web browsing, instant messaging, voice over IP (VoIP), and other services. Although it is not necessary to employ VoIP or IP telephony service machinery for rich call servicing, it is expected that IP telephony and/or IP multimedia will emerge as the technology of choice for the rich call environment. Today, keyhole processing has been introduced into browsing services, whereby the server that is hosting the visited Web site may offer content other than that provided by the extensible markup. Such content, for example, may include live video feeds from traffic cameras dispatched throughout the city where the consumer resides. In such an instance, however, a server to person topology exists, whereby a server within the network provides the video feed directly to the person that is currently visiting the Web site. Future keyhole processing within the Mobile Internet will not only involve such a server to person topology, but alternate multi-domain environments will also be involved in keyhole processing. The multi-domain environments will include, for example, a Personal Computer (PC) or other hardware platform involved with a mobile terminal during a person to person communication session, or conversely a Personal Digital Assistant (PDA) to mobile terminal communication session. As person to person communications improve, versatility and consumer satisfaction continue to grow. Accordingly, conventional person to person communication sessions involving multi-domain environments continue to require refinement. One such area of improvement relates to communication sessions involving video data that may be required to be exchanged between the communication session participants. Accordingly, there is a need for continued improvement in the communications industry for enablement of rich call sessions in a multi-domain environment. SUMMARY OF THE INVENTION To overcome limitations in the prior art, and to overcome other limitations that will become apparent upon reading and understanding the present specification, the present invention discloses a system and method that allows keyhole frame images to be transmitted from a hosting terminal to a receiving terminal during a communication session, where the keyhole frame images may be modified by the receiving terminal. In accordance with one embodiment of the invention, a method of exchanging data between participants of a communication session comprises establishing a voice connection between participants of the communication session, activating a keyhole frame within a display of a hosting terminal that is in proximity to a first participant, establishing a stream connection between the first participant and a second participant, streaming image data contained within the keyhole frame from the hosting terminal to a mobile terminal proximately located to the second participant via the stream connection, and establishing data connections between ones of the participants of the communication session and the mobile terminal. In accordance with another embodiment of the invention, a keyhole frame processing system comprises first and second mobile terminals wirelessly adapted to establish a voice connection between them and a hardware platform wirelessly coupled to the second mobile terminal and adapted to establish a data connection between the second mobile terminal and the hardware platform. The hardware platform comprises a display and a keyhole frame application adapted to place a keyhole frame anywhere within a viewable area of the display. The keyhole frame application is further adapted to transmit image data contained within the keyhole frame to the second mobile terminal via the data connection. In accordance with another embodiment of the invention, a mobile terminal is wirelessly coupled to a network which includes a hardware platform capable of transmitting video content to the mobile terminal. The mobile terminal comprises a memory capable of storing at least a keyhole frame module and a processor coupled to the memory. The processor is configured by the keyhole frame module to enable projecting the video content to a display of the mobile terminal. The mobile terminal further comprises a transceiver that is configured to facilitate the image exchange with the hardware platform. The keyhole frame module is further adapted to generate edit commands to change the video content displayed by the mobile terminal. In accordance with another embodiment of the invention, a computer-readable medium having instructions stored thereon which are executable by a mobile terminal for exchanging video content with a hardware platform performs steps comprising establishing a first connection with a second mobile terminal to provide voice communications between the mobile terminal and the second mobile terminal, establishing a second connection with the hardware platform, where the hardware platform is proximately located with the second mobile terminal. The steps further comprise receiving video data from the hardware platform via the second connection and providing commands to the hardware platform that affect the video data received from the hardware platform. The commands are provided via one of the first connection or second connection. In accordance with another embodiment of the invention, a hardware platform comprises means for establishing first and second connections with a mobile terminal, means for exchanging voice communications with the mobile terminal via the first connection, means for generating video data contained within a keyhole frame, the keyhole frame being defined by keyhole frame parameters to lie within a display region of the hardware platform, and means for providing the video data to the mobile terminal via the second connection. In accordance with another embodiment of the invention, a computer-readable medium having instructions stored thereon which are executable by a hardware platform performs steps comprising establishing first and second connections with a mobile terminal, exchanging voice communications with the mobile terminal via the first connection, generating video data contained within a keyhole frame, where the keyhole frame is defined by keyhole frame parameters to lie within a display region of the hardware platform. The steps further comprise providing the video data to the mobile terminal via the second connection, where external commands are received that change the keyhole frame parameters. These and various other advantages and features of novelty which characterize the invention are pointed out with greater particularity in the claims annexed hereto and form a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to accompanying descriptive matter, in which there are illustrated and described specific examples of a system and method in accordance with the invention. BRIEF DESCRIPTION OF THE DRAWINGS The invention is described in connection with the embodiments illustrated in the following diagrams. FIG. 1 illustrates a block diagram according to the principles of the present invention; FIG. 2 illustrates an exemplary content exchange mechanism in accordance with the present invention; FIG. 3 illustrates an exemplary block diagram of the content capture/receipt mechanism of FIG. 2; FIG. 4 illustrates an exemplary video conferencing scenario in accordance with the present invention; FIG. 5 illustrates an exemplary flow chart of a method in accordance with the present invention; FIG. 6 illustrates a representative mobile computing arrangement suitable for displaying/modifying image data transmitted by a hardware platform in accordance with the present invention; and FIG. 7 is a representative computing system capable of carrying out image processing functions according to the present invention. DETAILED DESCRIPTION OF THE INVENTION In the following description of the exemplary embodiment, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration various embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized, as structural and operational changes may be made without departing from the scope of the present invention. Generally, the present invention is directed to a method and apparatus allowing keyhole frame images to be transmitted to a receiving terminal during a communication session. The keyhole frame is movable and resizable throughout the display of the hosting terminal, whereby the image captured by the keyhole frame is transmitted to the receiving terminal during the communication session. Modifications to the image may be directed by the receiving terminal either through voice commands sent to the hosting terminal from the receiving terminal, or alternatively through cursor/pointing device commands actuated from the receiving terminal itself. All modifications effected on the keyhole frame image at the hosting terminal are viewed in real time at the receiving terminal. A rich call is perceived to relate to a consumer's immediate, personal, person to person communication needs. Some of these needs can already be satisfied today with telephony services, such as the basic voice call, voice mail, and call forwarding services offered by carriers employing, for example, Global System for Mobile Communication (GSM) technologies. The key in a rich call, however, is the consumer experience: the value and potential of combining telephony with other elements to provide enriched services. Voice calls, for example, may evolve into rich calls, during which audio, video, image, or other data can be shared. The present invention improves upon the current state of the art of person to person communication, through the activation of keyhole frame processing. In general, a keyhole frame may be activated by a user, whereby a portion of the display that lies within the keyhole frame may be captured for subsequent transfer/storage within the communication device being used, e.g., Personal Computer (PC), Personal Digital Assistant (PDA), mobile terminal, etc. The keyhole frame may be of any size and shape desired by the user and it may be negotiable depending on the terminal capabilities, e.g., screen size, at any time before, during, or after the communication session. Other person(s) in communication with the user may view whatever the user has selected to be captured by the keyhole frame. The keyhole frame may represent a portion of the user's display, or conversely, may represent any other file/application that the user wishes to share with the other persons involved in the communication session. The shared keyhole frame may be shared through any number of wired network topologies such as Digital Subscriber Line (DSL), Plain Old Telephone Service (POTS), Integrated Services Digital Network (ISDN). Wireless cellular networks utilizing multiple access technologies such as, Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA), and GSM may also be employed to share the keyhole frame. Still further, proximity technologies like Bluetooth, Wireless Local Area Network (WLAN), InfraRed (IR) may also be used to facilitate keyhole frame exchange according to the present invention. FIG. 1 illustrates rich call network 100 allowing versatile reachability and connectivity schemes to be employed by consumers to freely use services with whatever device best suits their communication needs—based on the consumer's relative time and position, independent of the particular access technology or network environment 112 being used at that moment. The use of visual content enables the present invention to offer many new services and applications such as: mobile interactive games; team collaboration; and business to customer service solutions. Initiation of call 108 from mobile terminal 102 to mobile terminal 106 is performed by any one of a number of methods currently available. For example, the user of mobile terminal 102 may select the user of mobile terminal 106 from a buddy list or dynamic phone book, which includes presence and any other information that the user of mobile terminal 106 wants to publish about himself. The user of mobile terminal 102 may instead access mobile terminal 106 through Web page access of the user's name and number so that the user's context and location may be taken into account prior to call setup of call 108. During call 108, the call participants may toggle between different media types, such that while the audio portion of call 108 is transpiring, live video or snapshots may be exchanged. The present invention further allows sharing of a user's display view, allowing, for example, the display or a portion of the display of PC 104 to be projected onto the display of mobile terminal 106, while call 108 is in process. In particular, keyhole frame 114 may be selected by the user of PC 104 to allow the user of mobile terminal 106 to see what the user of PC 104 wants him to see. In order to illustrate an exemplary usage of rich call network 100, a scenario will now be explored whereby the user of mobile terminal 106 is a Chief Executive Officer (CEO) and the user of mobile terminal 102 is the secretary of the CEO. The secretary has prepared some material for a presentation that the CEO will be giving on a particular business trip, while the CEO is en route to the presentation venue. Call 108 is established between the secretary and the CEO to initiate a person to person communication session. The person to person communication session is then augmented by second call 116, initiated by the secretary between PC 104 and mobile terminal 106, to provide a conduit for delivery of streamed view 110 to the CEO. In particular, streamed view 110 is the projection of the contents of keyhole frame 114 onto the display of mobile terminal 106. Thus, while the secretary and the CEO are conducting voice communication via call 108, the secretary may allow the CEO to see a portion, e.g., keyhole frame 114, of the display of PC 104 via call 116 to supplement their conversation. Thus, the CEO's rich call experience is improved in accordance with the present invention. Resident within PC 104 is a frame application in accordance with the present invention, that allows a portion of the display of PC 104, e.g., 114, to be captured and subsequently streamed to mobile terminal 106, or any other terminal connected to rich call infrastructure 112. The size of keyhole frame 114 may have been previously optimized through the use of presence or capability information exchanged during the call setup of call 108 or 116, depending upon the ability of rich call infrastructure 112 to host negotiated capability information for call 116. Conversely, the use of profile information subscribed to by PC 104 in relation to the capabilities of mobile terminal 106 may be used to initially set the size of keyhole frame 114 in accordance with the display size of mobile terminal 106. If the initial resolution of projection 110 of keyhole frame 114 is not adequate for the CEO's purposes, the CEO may make a verbal request via call 108 for the secretary to adjust the resolution of keyhole frame 114. In such an instance, the secretary may then either “zoom in” or “zoom out” in accordance with the CEO's needs. Alternatively, or additionally, if the CEO wishes to view a differently sized portion of the display of PC 104, then the secretary may simply adjust the size of keyhole frame 114 to match the request. In any event, a rendering application within PC 104, or alternately within rich call infrastructure 112, may then receive the adjusted size/resolution of keyhole frame 114 and conform the resulting video stream to the pre-negotiated display size of mobile terminal 106. Applications within PC 104 may also adapt to the size of keyhole frame 114 once it has been determined, such that visibility of the application may be optimized at the remote end, e.g., mobile terminal 106. Once keyhole frame 114 has been adequately projected onto mobile terminal 106, the CEO may view the presentation materials produced by the secretary. Any updates to the presentation materials may then be communicated verbally via call 108 by the CEO for subsequent update by the secretary on PC 104. As each modification is being performed by the secretary, streamed view 110 is being projected onto the display of mobile terminal 106. In other words, as visual data within keyhole frame 114 changes, the display of mobile terminal 106 also changes to reflect the modifications made by the secretary, so that the CEO has real time review of the modifications being made. Keyhole frame 114 may also be arranged to follow the active cursor on the PC 104 screen. In such an instance, keyhole frame 114 is automatically centered around the active cursor, so that the CEO may experience a centered view of the modifications taking place on PC 104, thus obviating the need for the secretary to manually center keyhole frame 114 around the content being modified. Once all of the modifications have been implemented, the presentation is instantly in its final version, since no further review is required by the CEO. In an alternate embodiment in accordance with the present invention, keyhole frame 114 may represent a file or application, such as a word processing or a presentation generation utility. In such an instance, the frame displayed by such a file or application becomes keyhole frame 114, whereby each keystroke and pointing device input performed by the secretary on keyhole frame 114 becomes visible to the CEO on the display of mobile terminal 106. Initially, the secretary is given control over any editing processes being performed on the file. However, the secretary may pass control over to the CEO, such that the CEO is given control over the editing process. In this case, although the file being edited is local to PC 104, the editing input is nevertheless being generated at mobile terminal 106. Thus, if the secretary does not understand the verbal modification instructions given via the voice call, the CEO may demonstrate his instructions visually by causing the visual content of keyhole frame 114 to be modified by cursor/pointing device actions performed on mobile terminal 106. In this way, the rich call communication session allows simultaneous modifications to the visual content of keyhole frame 114 by each member of the communication session (there may be more than just two), where only a single copy of the file being edited is required. FIG. 2 illustrates block diagram 200 of exemplary content exchange mechanisms utilized by mobile terminal 206 and hardware platform 202 during a rich call exchange in accordance with the present invention. In general, mobile terminal 206 and hardware platform 202 are arranged to exchange data using paths 218 and 220 via rich call connection 204. The nature of the data transfer may be of any type and rate that is supported by rich call connection 204, mobile terminal 206 and hardware platform 202. One of ordinary skill in the art will recognize that any data type may be supported by such an arrangement. For purposes of exemplifying the present invention, block diagram 200 is discussed in terms of a content transport mechanism between mobile terminal 206 and hardware platform 202, whereby rich call connection 204 is utilized as the communication conduit between the two devices. Rich call connection 204 may represent a wired and/or a wireless connection. Wired implementations of rich call connection 204 may include, for example, POTS, DSL or ISDN, whereas other, non-telecommunications based wired implementations may simply use the Universal Serial Bus (USB), or FireWire, specifications, for example. Wireless, non-cellular implementations of rich call connection 204 may include WLAN, Bluetooth, Infrared, etc., whereas cellular implementations utilizing TDMA, CDMA, W-CDMA, GPRS, etc. may be used as required by the particular application. In operation, hardware platform 202 may be a device having content capture/receipt capability 208 that is used for generation of keyhole frame 114 and its contents as illustrated in FIG. 1. Content capture/receipt 208 provides video data, whereby the images may be presented in still and/or video mode. In still mode, only a single image is transferred via path 210 to First-In First-Out (FIFO) buffer 214. In video mode, multiple images arranged in back to back frame sequence are transferred to FIFO buffer 214 at a rate that conforms with the bandwidth requirements of rich call connection 204. FIFO buffer 214 buffers the content blocks, while content delivery/receipt 218 prepares for their subsequent transfer to mobile terminal 206 via path 218 through rich call connection 204. Path 220 is used by content receipt/delivery 222 to acknowledge receipt of the images transmitted from content delivery 216 via rich call connection 204 as well as to provide edit commands associated with the received video content as discussed below. Buffer and synchronization block 224 is used to provide the proper frame alignment and playback speed as required by presentation 226. Presentation 226 represents any Application Programming Interface (API) that is executing on mobile terminal 206 including image processing software required by mobile terminal 206 for subsequent display. The images transferred via rich call path 204 may be formatted and rendered in accordance with the capabilities of the display (not shown) of mobile terminal 206. Additionally, the images may be transferred in any one of a number of video formats to include Moving Pictures Expert Group (MPEG), MPEG version 4 (MPEG-4), Joint Photographic Experts Group (JPEG), to name only a few. In addition, vector graphics files may be transmitted, where creation of digital images is facilitated through a sequence of commands or mathematical statements that place lines and shapes in a given two-dimensional or three-dimensional space. In vector graphics, the file that results is created and saved as a sequence of vector statements. For example, instead of containing a bit in the file for each bit of a line drawing, a vector graphic file describes a series of points to be connected. Alternatively, the vector graphics file may be converted to a raster graphics image by content delivery/receipt 216 prior to transmission, so as to increase portability between systems. Additionally, animation images are also usually created as vector graphic files, using content creation products that allow creation of 2-D and 3-D animations that may be sent to content receipt/delivery 222 as a vector file and then rasterized “on the fly” as they arrive by presentation 226. Control data may also be transferred via rich call connection 204 between mobile terminal 206 and hardware platform 202. In particular, as a result of the data displayed by presentation 226 on the display (not shown) of mobile terminal 206, the user of mobile terminal 206 may wish to make changes to the data displayed. Since only the graphical representations of the data contained within content capture/receipt 208 are presented by presentation 226, commands may be sent from content receipt/delivery 222 to command processor 228 to effect changes on the data that is stored within content capture/receipt 208. Such is the case, for example, when the data presented by presentation 226 is the contents of a word processing file contained within content capture/receipt 208. If modifications are to made by mobile terminal 206, then authorization to make such modifications is granted by hardware platform 202 via rich call connection 204. Accordingly, data modification commands are transmitted by mobile terminal 206 to hardware platform 202 via path 220 to effect such changes to the data. In response, the updated graphical representations of the edited data are provided to mobile terminal 206 from hardware platform 202 via path 218. In an alternate embodiment, changes to the data stored within content capture/receipt 208 may be effected by hardware platform 202 itself, where the graphical representations of the changes to the data are immediately provided to mobile terminal 206 via path 218 for subsequent display by presentation 226. In this way, as modifications to the data are being made at hardware platform 202, the user of mobile terminal 206 is immediately made aware of them. FIG. 3 illustrates exemplary block diagram 300 exhibiting some of the key elements provided by content capture/receipt 208 of FIG. 2 as they relate to the principles of the present invention. Video feed 302 provides a series of images to video configuration block 304 representing, for example, the video data presented to the display of PC 104. Video configuration parameters 308 are received by video configuration 304 to define the configuration parameters used for the generation of keyhole frame 114 such as: aspect ratio, position, portion of video feed 302 to be represented within keyhole frame 114, etc. Video configuration parameters 308 may also represent cursor and pointing device control placement parameters provided by mobile terminal 106 after PC 104 has granted modification rights to mobile terminal 106. In such an instance, for example, keyhole frame 114 contains content to be edited by mobile terminal 106. Any control input generated by mobile terminal 106 that is construed by video configuration parameters 308 as being file edit commands, are provided to file Input/Output (I/O) 318, so that the appropriate file content may be updated and thus incorporated by video feed 302. Video configuration parameters 308 may also represent cursor and pointing device control placement parameters that are provided by PC 104. In such an instance, for example, keyhole frame 114 contains content to be edited by PC 104, based on verbal commands received from mobile terminal 106 via call 108. Any control input generated by PC 104 that is construed by video configuration parameters 308 as being file edit commands, are provided to file Input/Output (I/O) 318, so that the appropriate file content may be updated. Accordingly, any changes to the file currently being displayed by keyhole frame 114, whether they be locally generated by PC 104 or remotely generated by mobile terminal 106, are immediately reflected in keyhole frame 114. Video encoder 306 receives the video content represented by keyhole frame 114 at a configurable frame rate. Video encoder 306 then implements video compression methods that exploit redundant and perceptually irrelevant parts of the video frames received from video configuration 304. The redundancy can be categorized into spatial, temporal, and spectral components; where spatial redundancy relates to correlation between neighboring pixels; temporal redundancy relates to objects likely to appear in present frames that were there in past frames; and spectral redundancy addresses the correlation between the different color components of the same image. Video encoder 306 achieves video compression by generating motion compensation data, which describes the motion between the current and previous image of two consecutive video frames. Video encoder 306 may seek to establish a constant bit rate for video bit stream 316, in which case video encoder 306 controls the frame rate as well as the quality of images contained within video frame 312. Video encoder 306 groups video bit stream 316 and header 314 into video frame 312 and then streams video frame 312, and subsequently formed video frames, to mobile terminal 106 via call 116, where header 314 provides specific information about the file format such as video coding type, length of frame, frame identifier, etc. Video encoder 306 may implement a video COder/DECoder (CODEC) algorithm defined by ITU-T H.263, which is an established CODEC scheme used in various multimedia services. H.263 provides a wide toolbox of various encoding tools and coding complexities for different purposes. A definition of the tools to be used and the allowed complexity of the mode are defined in CODEC profiles and levels, such as Profile 0, Level 10, also known as the H.263 baseline, has been defined as a mandatory video CODEC. Video encoder 306 may also support decoding of video bit-stream content conforming to MPEG-4 Visual Simple Profile, Level 0. Other proprietary video coding formats, such as RealVideo 7 and RealVideo 8, may be used that are recognized by the RealOne Player utility. FIG. 4 represents an enhanced video conferencing scenario 400 in accordance with the principles of the present invention, whereby the parties of meeting group 402 are participating in a meeting that the user of mobile terminal 410 is unable to attend due to prior travel commitments. Meeting group 402 and the user of mobile terminal 410 are spatially removed from one another, such as may be the case when a corporation has a number of production and engineering facilities that are geographically located across the globe from one another. In a particular case, for example, meeting group 402 may represent a group of management personnel located within the United States, who have assembled to exchange ideas with a senior production manager, i.e., the user of mobile terminal 410, who has traveled to a production facility in Finland. In such an example, meeting group 402 and the senior production manager are not equipped with standard video conferencing equipment, but are equipped with imaging capable mobile terminals 404 and 410. In addition, image processing capable PC 406 is provided in proximity to meeting group 402. PC 406 and mobile terminal 404 are also equipped with proximity connection capability to facilitate communication via link 416. Proximity link 416 may be represented by a Bluetooth, WLAN, IR, or other proximity communication link as required by the particular application. PC 406 and mobile terminal 410 are interconnected through rich call infrastructure 408 via path 418. PC 406 is equipped with a keyhole framing application as discussed above in relation to FIGS. 1-3. Such a keyhole framing application allows video data to be exchanged between PC 406 and mobile terminal 410, such that the images captured by mobile terminal 404 and subsequently transferred to PC 406 via Bluetooth connection 316 may be streamed to mobile terminal 410 via rich call path 418. In order to ultimately create the virtual meeting, voice path 420 is created as a call from mobile terminal 404 to mobile terminal 410. A user of mobile terminal 404, for example, may invoke his buddy list in order to locate the identification number associated with mobile terminal 410. Once located, a voice call is initiated by mobile terminal 404 to mobile terminal 410 to establish voice connection 420. Once a connection is established, a second call is placed by PC 406 to mobile terminal 410 to establish streaming path 418. PC 406 is executing the keyhole framing application which has been configured to: capture imaging data received from mobile terminal 404 via proximity connection 416; format/render the data in accordance with capabilities associated with mobile terminal 410; and stream the rendered data to mobile terminal 410 for subsequent display. Once communication paths 420 and 418 have been constructed, the virtual video conference may commence as planned. A third communication path 422 may then be established via rich call infrastructure 408, such that a second video stream may be established between PC 406 and mobile terminal 410. Communication path 422 is configured to allow files to be shared between meeting group 402 and the senior production manager, as discussed in relation to FIGS. 1-3 above, in order to facilitate the video conference. As such, any file that may be communicated between PC 406 and mobile terminal 410 may be simultaneously viewed by meeting group 402 via PC 406 and by the senior production manager via the display of mobile terminal 410. Thus, the senior production manager is actively involved with the virtual meeting through the combination of voice call 420 and video streams 418 and 422, whereby video streams 418 and 422 are selectively toggled onto the display of mobile terminal 410 by using keypad, pointing device, or voice commands from mobile terminal 410. The senior production manager may then communicate edit commands associated with the shared file to meeting group 402 via call 420 for subsequent input by meeting group 402. Alternatively, the senior production manager may insert his own edit commands into the shared file directly from mobile terminal 410. In either case, the result of the edit commands are simultaneously viewed by meeting group 402 via the display of PC 406 and viewed by the senior production manager via the display of mobile terminal 410 in accordance with the present invention. It should be noted that other sources of rich call data 424 may be exchanged with mobile terminal 410, while mobile terminal 410 interacts with calls 418-422. Other meeting groups, for example, located in different locations than meeting group 402 may also provide voice/data to mobile terminal 410 to supplement the virtual meeting. In such an instance, mobile terminal 410 is able to simultaneously receive all voice communications in full duplex mode, while maintaining the ability to toggle between multiple video feeds 418, 422, and 426. Flow diagram 500 of FIG. 5 illustrates an exemplary method in accordance with the principles of the present invention. In step 502, a voice connection is established, as discussed above in relation to FIGS. 1-4, between a hardware platform and a mobile terminal. In step 504, the desirability to activate a keyhole frame is determined by the hardware platform. If a keyhole frame is desired, then a user of the hardware platform, e.g., PC, PDA, or other computing device, formats the frame size, resolution, etc. to conform with the capabilities/desires of the mobile terminal as in step 506. A video stream connection is then established in step 510. Edit commands, from either the mobile terminal or the hardware platform, are then accepted in step 512 and the file is then updated as in step 514 in accordance with the edit commands. In either case, the file is streamed to the mobile terminal as in step 516 and displayed. As long as the keyhole frame is active, it will continue to be streamed to the mobile terminal as in step 518, so that the user of the mobile terminal is kept informed as to the content represented by the keyhole frame. During the active keyhole frame session, reconfiguration events may take place that affect the size/resolution of the keyhole frame. The reconfiguration events may be: automatically generated by the keyhole frame application executing within the hardware platform; manually generated by an operator at the hardware platform; or provided by the user at the mobile terminal via voice or electronic reconfiguration commands. Once a termination of the session has been generated by either of the hardware platform or mobile terminal, the session is then ended as in step 508. It should be noted that while the recipient terminal of the streamed video has been exemplified as a mobile terminal, those of ordinary skill in the art will recognize that any terminal capable of displayed graphical data may be used as the recipient terminal. That is to say that PC, PDAs, laptop computers, servers, etc. may be used to receive streamed video representative of keyhole frames in accordance with the present invention. The invention is a modular invention, whereby processing functions within either a mobile terminal or a hardware platform may be utilized to implement the present invention. The mobile terminals may be any type of wireless device, such as wireless/cellular telephones, personal digital assistants (PDAs), or other wireless handsets, as well as portable computing devices capable of wireless communication. These landline and mobile devices utilize computing circuitry and software to control and manage the conventional device activity as well as the functionality provided by the present invention. Hardware, firmware, software or a combination thereof may be used to perform the various imaging transfer functions described herein. An example of a representative mobile terminal computing system capable of carrying out operations in accordance with the invention is illustrated in FIG. 6. Those skilled in the art will appreciate that the exemplary mobile computing environment 600 is merely representative of general functions that may be associated with such mobile devices, and also that landline computing systems similarly include computing circuitry to perform such operations. The exemplary mobile computing arrangement 600 suitable for image data transfer/receipt functions in accordance with the present invention may be associated with a number of different types of wireless devices. The representative mobile computing arrangement 600 includes a processing/control unit 602, such as a microprocessor, reduced instruction set computer (RISC), or other central processing module. The processing unit 602 need not be a single device, and may include one or more processors. For example, the processing unit may include a master processor and associated slave processors coupled to communicate with the master processor. The processing unit 602 controls the basic functions of the mobile terminal, and also those functions associated with the present invention as dictated by camera hardware 630 and imaging software module 626/ keyhole frame application 628 available in the program storage/memory 604. Thus, the processing unit 602 is capable of facilitating image capture and keyhole framing functions associated with the present invention, whereby images received by keyhole frame application 626 from a remote hardware platform, may be processed in accordance with the present invention. The program storage/memory 604 may also include an operating system and program modules for carrying out functions and applications on the mobile terminal. For example, the program storage may include one or more of read-only memory (ROM), flash ROM, programmable and/or erasable ROM, random access memory (RAM), subscriber interface module (SIM), wireless interface module (WIM), smart card, or other removable memory device, etc. In one embodiment of the invention, the program modules associated with the storage/memory 604 are stored in non-volatile electrically-erasable, programmable ROM (EEPROM), flash ROM, etc. so that the information is not lost upon power down of the mobile terminal. The relevant software for carrying out conventional mobile terminal operations and operations in accordance with the present invention may also be transmitted to the mobile computing arrangement 600 via data signals, such as being downloaded electronically via one or more networks, such as the Internet and an intermediate wireless network(s). The processor 602 is also coupled to user-interface elements 606 associated with the mobile terminal. The user-interface 606 of the mobile terminal may include, for example, a display 608 such as a liquid crystal display, a keypad 610, speaker 612, camera hardware 630, and microphone 614. These and other user-interface components are coupled to the processor 602 as is known in the art. Other user-interface mechanisms may be employed, such as voice commands, switches, touch pad/screen, graphical user interface using a pointing device, trackball, joystick, or any other user interface mechanism. The mobile computing arrangement 600 also includes conventional circuitry for performing wireless transmissions. A digital signal processor (DSP) 616 may be employed to perform a variety of functions, including analog-to-digital (A/D) conversion, digital-to-analog (D/A) conversion, speech coding/decoding, encryption/decryption, error detection and correction, bit stream translation, filtering, etc. The transceiver 618, generally coupled to an antenna 620, transmits the outgoing radio signals 622 and receives the incoming radio signals 624 associated with the wireless device. The mobile computing arrangement 600 of FIG. 6 is provided as a representative example of a computing environment in which the principles of the present invention may be applied. From the description provided herein, those skilled in the art will appreciate that the present invention is equally applicable in a variety of other currently known and future mobile and landline computing environments. For example, desktop computing devices similarly include a processor, memory, a user interface, and data communication circuitry. Thus, the present invention is applicable in any known computing structure where data may be communicated via a network. Using the description provided herein, the invention may be implemented as a machine, process, or article of manufacture by using standard programming and/or engineering techniques to produce programming software, firmware, hardware or any combination thereof. Any resulting program(s), having computer-readable program code, may be embodied on one or more computer-usable media, such as disks, optical disks, removable memory devices, semiconductor memories such as RAM, ROM, PROMS, etc. Articles of manufacture encompassing code to carry out functions associated with the present invention are intended to encompass a computer program that exists permanently or temporarily on any computer-usable medium or in any transmitting medium which transmits such a program. Transmitting mediums include, but are not limited to, transmissions via wireless/radio wave communication networks, the Internet, intranets, telephone/modem-based network communication, hard-wired/cabled communication network, satellite communication, and other stationary or mobile network systems/communication links. From the description provided herein, those skilled in the art will be readily able to combine software created as described with appropriate general purpose or special purpose computer hardware to create a keyhole image processing system and method in accordance with the present invention. The hardware platforms or other systems for providing keyhole image processing functions in connection with the present invention may be any type of computing device capable of processing and communicating digital information. The hardware platforms utilize computing systems to control and manage the image processing activity. An example of a representative computing system capable of carrying out operations in accordance with the invention is illustrated in FIG. 7. Hardware, firmware, software or a combination thereof may be used to perform the various keyhole image processing functions and operations described herein. The computing structure 700 of FIG. 7 is an example computing structure that can be used in connection with such a hardware platform. The example computing arrangement 700 suitable for performing the image processing activity in accordance with the present invention includes hardware platform 701, which includes a central processor (CPU) 702 coupled to random access memory (RAM) 704 and read-only memory (ROM) 706. The ROM 706 may also be other types of storage media to store programs, such as programmable ROM (PROM), erasable PROM (EPROM), etc. The processor 702 may communicate with other internal and external components through input/output (I/O) circuitry 708 and bussing 710, to provide control signals and the like. For example, image data transmitted by I/O connections 708 or Internet connection 728 may be processed in accordance with the present invention. External data storage devices, such as presence or profile servers, may be coupled to I/O circuitry 708 to facilitate imaging functions according to the present invention. Alternatively, such databases may be locally stored in the storage/memory of hardware platform 701, or otherwise accessible via a local network or networks having a more extensive reach such as the Internet 728. The processor 702 carries out a variety of functions as is known in the art, as dictated by software and/or firmware instructions. Hardware platform 701 may also include one or more data storage devices, including hard and floppy disk drives 712, CD-ROM drives 714, and other hardware capable of reading and/or storing information such as DVD, etc. In one embodiment, software for carrying out the image processing and image transfer operations in accordance with the present invention may be stored and distributed on a CD-ROM 716, diskette 718 or other form of media capable of portably storing information. These storage media may be inserted into, and read by, devices such as the CD-ROM drive 714, the disk drive 712, etc. The software may also be transmitted to hardware platform 701 via data signals, such as being downloaded electronically via a network, such as the Internet. Hardware platform 701 is coupled to a display 720, which may be any type of known display or presentation screen, such as LCD displays, plasma display, cathode ray tubes (CRT), etc. A user input interface 722 is provided, including one or more user interface mechanisms such as a mouse, keyboard, microphone, touch pad, touch screen, voice-recognition system, etc. The hardware platform 701 may be coupled to other computing devices, such as the landline and/or wireless terminals via a network. The server may be part of a larger network configuration as in a global area network (GAN) such as the Internet 728, which allows ultimate connection to the various landline and/or mobile client/watcher devices. The foregoing description of the various embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. Thus, it is intended that the scope of the invention be limited not with this detailed description, but rather determined from the claims appended hereto. | <SOH> BACKGROUND OF THE INVENTION <EOH>Over the last decade, there has been a merger of two of the most successful communications tools ever developed—mobile communications and the Internet. The Internet has provided access to many kinds of services, information, and content through one common interface. Mobile communications has provided the concept of being reachable at any time and with the ability to reach other people or services quickly. Combining the freedom of the Internet with the reachability and immediacy of mobile networks, the Mobile Internet has been born. Service creation for the Mobile Internet is based on an open content format, e.g., eXtensible Markup Language (XML), and Internet Engineering Task Force (IETF) defined protocols, such as the Session Initiation Protocol (SIP). Service mobility through open content format provides accessibility of a consumer's personalized services through any access network or device, whereby service reachability through the open content format provides services that follow the consumer wherever he or she may go. While services such as messaging and browsing continue to be important to today's Mobile Internet user, person to person communications will remain as one of the most important services offered by the Mobile Internet. As the Mobile Internet technology advances, communications will combine multiple media types and communication methods with presence and community information, not only to enhance person to person communication, but also to enhance multi-point to multi-point communication, i.e., conferencing. With the use of Internet Protocol (IP), for example, addition of rich media is facilitated through the use of standardized networking and signaling protocols. A media enhanced call, i.e., rich call, may be defined as a voice or video conversation that is supported with concurrent access to an image, data, or other information during a single session. SIP will provide enabling technology for rich calls, where the Web and Mobile domains may be joined for true service mobility and access independence. SIP's support for rich calls will add “see what I see”, or “keyhole” capability for consumers through a combination of voice, mail, Web browsing, instant messaging, voice over IP (VoIP), and other services. Although it is not necessary to employ VoIP or IP telephony service machinery for rich call servicing, it is expected that IP telephony and/or IP multimedia will emerge as the technology of choice for the rich call environment. Today, keyhole processing has been introduced into browsing services, whereby the server that is hosting the visited Web site may offer content other than that provided by the extensible markup. Such content, for example, may include live video feeds from traffic cameras dispatched throughout the city where the consumer resides. In such an instance, however, a server to person topology exists, whereby a server within the network provides the video feed directly to the person that is currently visiting the Web site. Future keyhole processing within the Mobile Internet will not only involve such a server to person topology, but alternate multi-domain environments will also be involved in keyhole processing. The multi-domain environments will include, for example, a Personal Computer (PC) or other hardware platform involved with a mobile terminal during a person to person communication session, or conversely a Personal Digital Assistant (PDA) to mobile terminal communication session. As person to person communications improve, versatility and consumer satisfaction continue to grow. Accordingly, conventional person to person communication sessions involving multi-domain environments continue to require refinement. One such area of improvement relates to communication sessions involving video data that may be required to be exchanged between the communication session participants. Accordingly, there is a need for continued improvement in the communications industry for enablement of rich call sessions in a multi-domain environment. | <SOH> SUMMARY OF THE INVENTION <EOH>To overcome limitations in the prior art, and to overcome other limitations that will become apparent upon reading and understanding the present specification, the present invention discloses a system and method that allows keyhole frame images to be transmitted from a hosting terminal to a receiving terminal during a communication session, where the keyhole frame images may be modified by the receiving terminal. In accordance with one embodiment of the invention, a method of exchanging data between participants of a communication session comprises establishing a voice connection between participants of the communication session, activating a keyhole frame within a display of a hosting terminal that is in proximity to a first participant, establishing a stream connection between the first participant and a second participant, streaming image data contained within the keyhole frame from the hosting terminal to a mobile terminal proximately located to the second participant via the stream connection, and establishing data connections between ones of the participants of the communication session and the mobile terminal. In accordance with another embodiment of the invention, a keyhole frame processing system comprises first and second mobile terminals wirelessly adapted to establish a voice connection between them and a hardware platform wirelessly coupled to the second mobile terminal and adapted to establish a data connection between the second mobile terminal and the hardware platform. The hardware platform comprises a display and a keyhole frame application adapted to place a keyhole frame anywhere within a viewable area of the display. The keyhole frame application is further adapted to transmit image data contained within the keyhole frame to the second mobile terminal via the data connection. In accordance with another embodiment of the invention, a mobile terminal is wirelessly coupled to a network which includes a hardware platform capable of transmitting video content to the mobile terminal. The mobile terminal comprises a memory capable of storing at least a keyhole frame module and a processor coupled to the memory. The processor is configured by the keyhole frame module to enable projecting the video content to a display of the mobile terminal. The mobile terminal further comprises a transceiver that is configured to facilitate the image exchange with the hardware platform. The keyhole frame module is further adapted to generate edit commands to change the video content displayed by the mobile terminal. In accordance with another embodiment of the invention, a computer-readable medium having instructions stored thereon which are executable by a mobile terminal for exchanging video content with a hardware platform performs steps comprising establishing a first connection with a second mobile terminal to provide voice communications between the mobile terminal and the second mobile terminal, establishing a second connection with the hardware platform, where the hardware platform is proximately located with the second mobile terminal. The steps further comprise receiving video data from the hardware platform via the second connection and providing commands to the hardware platform that affect the video data received from the hardware platform. The commands are provided via one of the first connection or second connection. In accordance with another embodiment of the invention, a hardware platform comprises means for establishing first and second connections with a mobile terminal, means for exchanging voice communications with the mobile terminal via the first connection, means for generating video data contained within a keyhole frame, the keyhole frame being defined by keyhole frame parameters to lie within a display region of the hardware platform, and means for providing the video data to the mobile terminal via the second connection. In accordance with another embodiment of the invention, a computer-readable medium having instructions stored thereon which are executable by a hardware platform performs steps comprising establishing first and second connections with a mobile terminal, exchanging voice communications with the mobile terminal via the first connection, generating video data contained within a keyhole frame, where the keyhole frame is defined by keyhole frame parameters to lie within a display region of the hardware platform. The steps further comprise providing the video data to the mobile terminal via the second connection, where external commands are received that change the keyhole frame parameters. These and various other advantages and features of novelty which characterize the invention are pointed out with greater particularity in the claims annexed hereto and form a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to accompanying descriptive matter, in which there are illustrated and described specific examples of a system and method in accordance with the invention. | 20040227 | 20080708 | 20050901 | 94653.0 | 0 | VU, VIET D | METHOD AND APPARATUS FOR KEYHOLE VIDEO FRAME TRANSMISSION DURING A COMMUNICATION SESSION | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,789,488 | ACCEPTED | Solar powered light assembly to produce light of varying colours | A garden light 10 having a body (11) with a post (12), the lower end of which is provided with a spike (13). The upper end of the post (11) receives a lens assembly (12). Secured to the lens assembly (12) is a cap assembly (24) that has three LEDs that are activated to produce a varying colour light. | 1. A lighting device to produce light of varying colour, said device including: a body; a lens mounted on the body and generally enclosing a chamber having an upper rim surrounding a top opening, and a bottom region; a reflector mounted in the bottom region; a cap assembly including securing means to releasably engage the rim so that the cap assembly can be selectively removed from the lens; said assembly including: a base; a circuit having at least two lamps of different colours to produce a desired colour including a varying colour, the lamps being mounted to direct light into said chamber, connections for at least one rechargeable battery to power the circuit and a solar cell mounted on an exposed surface of the assembly and operatively associated with the connections to charge the battery, and a switch operated to control delivery of electric power from the battery to operate said circuit, the switch being exposed to provide for access thereto by a user. 2. The light device of claim 1 wherein, said circuit includes a light sensitive switch that renders the circuit operation at low light levels. 3. The device of claim 2 wherein, said switch is on an exposed downwardly facing surface. 4. The device of claim 1 wherein, said circuit includes three lamps, each of a different colour. 5. The device of claim 1 wherein, said lens is a first lens, and said device includes a second lens, said second lens being attached to said base and providing a cavity into which the LEDs direct light, with the light leaving said second lens then passing through said first lens. 6. The device of claim 5 wherein, the first and second lenses diffuse light. 7. The device of claim 6 wherein, said body includes a post having opposite first and second ends, with a spike attached to said first end, and said first lens attached to said second end. 8. The device of claim 7 wherein, said second lens is detachably secured to said post. 9. The lighting device of claim 1 wherein, said circuit includes a light sub-circuit connected to the lamps to deliver electric power thereto so that the lamps produce said desired colour, with said switch being an on/off switch to deliver electric power from the batteries to said sub-circuit. 10. The lighting device of any one of claims 1 wherein, said circuit includes a light sub-circuit having an integrated circuit operable to select a desired fixed colour, with said switch being connected to said integrated circuit and operated to select said desired fixed colour. 11. The device of claim 9 wherein, said switch is a first switch, and said sub-circuit includes an integrated circuit and a second switch connected to said integrated circuit, the second switch being operable to select a desired fixed colour and exposed to provide for access thereto by a user. 12. The device of claim 11 wherein, said second switch is on said exposed external surface. 13. The device of claim 1 wherein, said switch is on an exposed downwardly facing surface. 14. The device of claim 13 wherein, said circuit includes three lamps, each of a different colour. 15. The device of claim 14 wherein, said lens is a first lens, and said device includes a second lens, said second lens being attached to said base and providing a cavity into which the LEDs direct light, with the light leaving said second lens then passing through said first lens. 16. The lighting device of claim 14 wherein, said circuit includes a light sub-circuit connected to the lamps to deliver electric power thereto so that the lamps produce said desired colour, with said switch being an on/off switch to deliver electric power from the batteries to said sub-circuit. 17. The lighting device of claim 14 wherein, said circuit includes a light sub-circuit having an integrated circuit operable to select a desired fixed colour, with said switch being connected to said integrated circuit and operated to select said desired fixed colour. 18. The device of claim 16 wherein, said switch is a first switch, and said sub-circuit includes an integrated circuit and a second switch connected to said integrated circuit, the second switch being operable to select a desired fixed colour and exposed to provide for access thereto by a user. 19. The device of claim 18 wherein, said second switch is on said exposed external surface. 20. A lighting device to produce light of varying colour, said device including: a body; a lens mounted on the body and generally enclosing a chamber; a circuit having at least two lamps of different colours to produce a desired colour including a varying colour, the lamps being mounted to direct light into said chamber, connections for at least one rechargeable battery to power the circuit and a solar cell mounted on an exposed surface of the assembly and operatively associated with the connections to charge the battery, and a switch operable to control delivery of electric power from the battery to operate said circuit, the switch being exposed to provide for access thereto by a user. 21. The lighting device of claim 20 wherein, said circuit includes a light sensitive switch that renders the circuit operative at low light levels. 22. The lighting device of claim 20 wherein, said circuit includes alight sub-circuit connected to the lamps to deliver electric power thereto so that the lamps produce said desired colour, with said switch being an on/off switch to deliver electric power from the batteries to said sub-circuit. 23. The lighting device of claim 20 wherein, said circuit includes alight sub-circuit having an integrated circuit operable to select a desired fixed colour, with said switch being connected to said integrated circuit and operable to select said desired fixed colour. 24. The device of claim 20 wherein, said circuit includes a sub-circuit, said switch is a first switch said first switch being an on/off switch to deliver electric power from the battery to said sub-circuit, and said sub-circuit includes an integrated circuit and a second switch connected to said integrated circuit, the second switch being operable to select a desired fixed colour and exposed to provide for access thereto by a user. 25. The device of claim 24 wherein, said second switch is on said exposed external surface. 26. The lighting device of claim 21 wherein, said circuit includes a light sub-circuit connected to the lamps to deliver electric power thereto so that the lamps produce said desired colour, with said switch being an on/off switch to deliver electric power from the batteries to said sub-circuit. 27. The lighting device of claim 26 wherein, said circuit includes alight sub-circuit having an integrated circuit operable to select a desired fixed colour, with said switch being connected to said integrated circuit and operable to select said desired fixed colour. 28. The device of claim 21 wherein, said circuit includes a sub-circuit, said switch is a first switch said first switch being an on/off switch to deliver electric power from the battery to said sub-circuit, and said sub-circuit includes an integrated circuit and a second switch connected to said integrated circuit, the second switch being operable to select a desired fixed colour and exposed to provide for access thereto by a user. 29. The device of claim 28 wherein, said second switch is on said exposed external surface. | TECHNICAL FILED The present invention relates to solar powered lights and more particularly but not exclusively to solar powered lights that produce a light of varying colour. BACKGROUND OF THE INVENTION Light devices that employ light emitting diode (LED) systems to produce a variable colour are known. Examples are described in U.S. Pat. Nos.6,459,919, 6,608,458, 6,150,774 and 6,016,038. It is also known to have “garden lights” that are solar powered. For example such garden lights include a body providing a spike that is driven into a ground surface. At the upper end of the spike there is mounted a diffuser surrounding a lamp, with the lamp being driven by rechargeable batteries and a solar cell. The abovementioned lighting apparatus have a number of disadvantages including difficulty in adjusting the various lighting functions and not producing a uniform desired colour when required to do so. OBJECT OF THE INVENTION It is the object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages. SUMMARY OF THE INVENTION There is disclosed herein a lighting device to produce light of varying colour, said device including: a body; a lens mounted on the body and generally enclosing a chamber having an upper rim surrounding a top opening, and a bottom region; a reflector mounted in the bottom region; a cap assembly including securing means to releasably engage the rim so that the cap assembly can be selectively removed from the lens; said assembly including: a base; a circuit having at least two lamps of different colours which are activated to produce a desired colour including a varying colour, the lamps being mounted to direct light into said chamber, a solar cell mounted on an exposed surface of the assembly and rechargeable batteries to power the circuit, a light sub-circuit connected to the lamps to deliver electric power thereto so that the lamps produce said desired colour, and a switch operable to deliver electric power from the batteries and cell to said sub-circuit, the switch being exposed to provide for access thereto by a user. Preferably, said circuit includes a light sensitive switch that renders the circuit operation at low light levels. Preferably, said switch is on an exposed downwardly facing surface. Preferably, said circuit includes three lamps, each of a different colour. Preferably, said lens is a first lens, and said device includes a second lens, said second lens being attached to said base and providing a cavity into which the LEDs direct light, with the light leaving said second lens then passing through said first lens. Preferably, the first and second lenses diffuse light. Preferably, said body includes a post having opposite first and second ends, with a spike attached to said first end, and said first lens attached to said second end. Preferably, said second lens is detachably secured to said post. Preferably, said switch is a first switch, and second sub-circuit includes an integrated circuit and a second switch connected to said integrated circuit, the second switch being exposed to provide for access thereto by a user. Preferably, said second switch activates said integrated circuit to select a desired colour. Preferably, said second switch is on said exposed surface. There is further disclosed herein a lighting device to produce light of varying colour, said device including: a body; a lens mounted on the body and generally enclosing a chamber; a circuit having at least two lamps of different colours to produce a desired colour including a varying colour, the lamps being mounted to direct light into said chamber, connections for at least one rechargeable battery to power the circuit and a solar cell mounted on an exposed surface of the assembly and operatively associated with the connections to charge the battery, and a switch operated to control delivery of electric power from the battery to operate said circuit, the switch being exposed to provide for access thereto by a user. Preferably, said circuit includes a light sensitive switch that renders the circuit operative at low light levels. Preferably, said circuit includes a light sub-circuit connected to the lamps to deliver electric power thereto so that the lamps produce said desired colour, with said switch being an on/off switch to deliver electric power from the batteries to said sub-circuit. Preferably, said circuit includes a light sub-circuit having an integrated circuit operable to select a desired fixed colour, with said switch being connected to said integrated circuit and operable to select said desired fixed colour. Preferably, said circuit includes a sub-circuit, said switch is a first switch said first switch being an on/off switch to deliver electric power from the battery to said sub-circuit, and said sub-circuit includes an integrated circuit and a second switch connected to said integrated circuit, the second switch being operable to select a desired fixed colour and exposed to provide for access thereto by a user. Preferably, said second switch is on said exposed external surface. BRIED DESCRIPTION OF THE DRAWINGS A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings wherein: FIG. 1 is a schematic side elevation of a lighting device; FIG. 2 is a schematic sectioned front elevation of the device of FIG. 1; FIG. 3 is a schematic sectioned side elevation of the device of FIG. 1; FIG. 4 is a schematic plan view of a moulding employed in the device of FIG. 1; FIG. 5 is a schematic plan view of a base member of the device of FIG.1; FIG. 6 is a schematic to plan view of a cap assembly employed in the device of FIG. 1; FIG. 7 is a schematic isometric view of a lens employed in the device of FIG. 1; FIG. 8 is a schematic isometric view of a second lens employed in the device of FIG. 1; FIG. 9 is a circuit diagram of the circuit of the board of FIG. 4; and FIG. 10 is a schematic perspective view of an ornamental garden light. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGS. 1 to 9 of the accompanying drawings there is schematically depicted a lighting device 10. The device 10 of this embodiment is configured as a “garden light”. The device 10 includes a body 11 including a post 12 from the lower end from which there extends a spike 13. The spike 13 is driven into a ground surface so that the post 12 is exposed above the ground surface. Attached to the upper end of the post 12 is a lens assembly 14. The lens assembly 14 includes a lens 15 that encompasses a chamber 16. The lower end of the lens 15 has fixed to it a “bayonet” fitting 17 that engages a shaft 18 fixed to the upper end of the post 12. The fitting 17 includes an “L” shaped slot 19 through which the shaft 18 passes to secure the lens assembly 14 to the upper end of the post 12. The chamber 16 includes a lower portion 20 within which there is mounted an arcuate reflector 21 that is concave. The lens 15 has a rim 22 surrounding the upper opening 23 of the lens 15. Removably attached to the rim 22 is a cap assembly 24. The assembly 24 includes a cover 25 fixed to a base 26. The base 26 is located beneath the cover 25 and is shielded thereby. The base 26 and cover 25 encompass a chamber 27 within which there is a mounted moulding 28. The moulding 28 is provided with battery compartments 32. The components of the circuit 29 are located within the chamber 27, while the upper surface of the assembly 27 is provided with the solar cell 30. The cell 30 is exposed through a central rectangular aperture 31 of the cap 25. Mounted within the chamber 27 via battery compartments 32 are rechargeable batteries 33 which are used to energise three LEDs 34. The LEDs 34 when illuminated produce red, green and blue light. The cap assembly 24 is generally circular in configuration so as to provide the device 10 with a generally vertical longitudinal axis 35. The base 26 has radially inward projecting flange segments 36 that engage with radially outward extending flange segments 37 of the rim 22 to be secured thereto. By angular movement of the cap assembly 24 about the axis 35, the segments 36 and 37 engage or disengage to secure or to release the assembly 24 with respect to the lens 15. As can be noted from FIG. 5, the flange segments 27 have end abutment portions 38 against which these segments 36 engage when the assembly 24 is secured to the lens 15. Mounted on the under surface of the base 26 is a second lens 38. Accordingly, the LEDs 34 when activated have their light preferably diffused by the lens 38 and then further diffused by the lens 15. This in particular aids in producing a more evenly coloured light when the LEDs 34 are activated. The circuit 29 powers and controls the lighting device 10 in accordance with an embodiment of this invention. The circuit 29 consists of a number of interconnected sub-circuits, including a power supply circuit, a light operated circuit, a boost-up circuit, a rectifier circuit, and a light circuit. The power supply circuit comprises a solar cell 30 connected in series to a forward biased diode 39, which is in turn connected to a positive terminal of a battery 33. A negative terminal of the battery 33 is then connected to the solar cell 30 to complete the power supply circuit. In this example, the diode 39 is a model number IN5817 Schottky diode and the battery comprises two rechargeable 1.2 volt battery cells. It will be apparent to a person skilled in the art that other diode and battery configurations may be utilised without departing from the spirit and scope of the invention. When the solar cell 30 is exposed to sufficient light, the solar cell converts some of the solar energy to electrical energy and creates a current that passes through the diode 39 to charge the battery 33. Thus, during the day the solar cell 30 converts energy from the sun to charge the battery 33. The diode 39 prevents the battery 33 from expending any power on the solar cell 30. The power supply circuit is connected in parallel to the light operated circuit, which is connected across the terminals of the battery 33. The positive terminal of the battery 33 is connected to a switch 40, which is in turn connected to a 100 kΩ first resistor 41. The first resistor 41 is connected in series with a second, light-dependent resistor 42. The second resistor 42 connects to the negative terminal of the batteries 33 to complete the light operated circuit. The value of resistance of the second resistor 42 depends on the amount of light to which the second resistor 42 is exposed. When there is not much light, such as occurs during the night, the value of the second resistor 42 increases. During the daytime, when there is sufficient light, the value of the second resistor 42 decreases. Accordingly the resistor 42 allows the lighting device to operate only when there is insufficient light, ie night. The boost-up circuit is connected to the light operated circuit, in parallel with the first resistor 41 and the second, light-dependent resistor 42. A first circuit node 43 is defined between the switch 40 and the first resistor 41. Connected to the node 43, is an emitter terminal of a first triode 44. A collector terminal of the first triode 44 is connected in series with a 100 kΩ third resistor 45. The third resistor 45 is then connected to a point between the first resistor 41 and the second resistor 42. A 220 kΩ fourth resistor 46 is connected to node 43 across the emitter and base terminals of the first triode 44. In parallel with the fourth resistor 46, and also connected across the emitter and base terminals of the first triode 44, is a 4.7 nF first capacitor 48. Further connected to node 43, across the emitter and base terminals of the first triode 44 and in parallel with each of the fourth resistor 46 and the first capacitor 48, is a 100 μH inductor 49 in series with a 1 nF second capacitor 50. The second capacitor is then connected to the base terminal of the first triode 44. A 20 kΩ fifth resistor 51 is connected across the base and collector terminals of the first triode 44. Connected across the terminals of the third resistor 45 are the collector and base terminals, respectively, of a second triode 52. The emitter terminal of the second triode 52 is connected to the negative terminal of the batteries 33. Connected between the inductor 49 and the second capacitor 50 is the collector terminal of a third triode 53. The base terminal of the third triode 53 is connected via an intermediary circuit to the collector terminal of the second triode 52. The intermediary circuit consists of a 2.4 kΩ fourth resistor 54 in parallel with a 1 nF third capacitor 55. The emitter terminal of the third triode 53 is connected to the negative terminal of the battery 33. Also connected between the inductor 49 and the second capacitor 50 is the rectifier circuit. A forward biased second diode 56 is connected to a point between the inductor 49 and the second capacitor 50, and then to a positive terminal of a 33 μF fourth capacitor 57. The negative terminal of the fourth capacitor 57 is connected to the negative terminal of the battery 33. A second circuit node 58 is defined between the second diode 56 and the fourth capacitor 57. Connected in parallel with the fourth capacitor 57, between the second node 58 and the negative terminal of the battery 33 is a reverse biased 4.5V third diode 59. The second diode 56, the fourth capacitor 57 and the third diode 59 comprise the rectifier circuit. Further connected to the second circuit node 58, in parallel with each of the capacitor 57 and the reverse diode 59, is a light circuit 60. The light circuit 60 contains an integrated circuit (IC) 61 for controlling lighting effects provided by the lighting device 10. In the embodiment shown, the IC 61 is a 16-pin, three colour LED IC for controlling first, second and third light emitting diodes (LEDs) 34A, 34B and 34C. Each of pins 1, 15 and 16 is connected in series to respective switches 69, 70, 60. Each of the switches 69, 70 and 71 is then connected to the negative terminal of the battery 33. In one embodiment, the switches 69, 70, 71 correspond to the LEDs 34A, 34B, and 34C to enable or disable a particular colour range. In another embodiment, the switches 69,70, 71 determine the frequency of a colour changing effect. In a further embodiment, the switches 69,70, 71 determine the intensity of light emitted by each of the LEDs 34A, 34B, and 34C. Various combinations of the frequency and intensity of light are also possible. The switches 69, 70, 71 can be made accessible to a user to create custom lighting effects. Alternatively, the switches 69, 70, 71 are set according to a predetermined configuration and are not readily accessible by a user. Pin 4 of the IC 61 enables an optional pause function. In this embodiment, pin 4 connects to a push button 65 that is, in turn, connected to the negative terminal of the batteries 33. Pin 3 of the IC 61 connects to the second circuit node 58. Connected to the second circuit node 58, and in parallel with one another, are the first second and third forward biased light emitting diodes (LEDs) 34A, 34B and 34C. The first LED 34A is connected in series with a sixth resistor 66 that is connected to pin 13 of the IC 61. The second LED 34B is connected in series with a seventh resistor 67 that is connected to pin 12 of the IC 61. The third LED 34C is connected in series with an eighth resistor 68 that is connected to pin 11 of the IC 61. In this example, the first LED 34A is blue, the second LED 34B is green and the third LED 34C is red. Pins 6 and 8 of the IC 61 are tied to one another via a ninth resistor 72, which in the embodiment shown is a 20 KΩ resistor. The valve of the ninth resistor 71 determines the frequency of a colour change created by the IC 61. Accordingly, using different resistor valves for the ninth resistor 71 produces colour changes of different frequencies. Pin 9 of the IC 61 is tied to the negative terminal of the battery 33. During the day, the solar cell 30 charges the battery 33. The value of the second resistor 42 is low and, consequently, small amounts of current flow through the boost-up circuit, rectifier circuit and light circuit. As night falls, the amount of energy converted by the solar cell 30 decreases. The resistance of the second resistor 42 increases and more current flows into the boost-up circuit, rectifier circuit and light circuit. This activates the LEDs 34A, 34B, and 34C in the light circuit and the light device 10 produces a changing light effect. The integrated circuit 61 controls each of the first, second and third LEDs 34A, 34B, and 34C to produce a changing light effect for the light device 10. The integrated circuit varies the frequency and intensity of light emitted by the LEDs 34A, 34B, and 34C to produce a constantly changing kaleidoscopic effect. The light device 10 displays a constantly changing lighting effect that cycles through the light spectrum by ramping up and ramping down the intensity of light displayed by the LEDs 34A, 34B, and 34C. Connecting the optional pause function of pin 4 of the IC 61 to the push button 65 enables a user to stop the changing light effect and maintain a constant colour. In this manner, a user can select a preferred colour for a lighting effect. The user observes the changing colour effect and when a desired colour is displayed, the user depresses the pause button 65. The colour displayed at the time that the button is pressed then remains on. Preferably, the circuit retains sufficient charge such that a user selected colour is retained during the day and is displayed again when the light is reactivated the following evening. In this manner, the user does not have to reselect a desired colour each night. To reinstate the changing light effect, the user presses the push button 65 again and the changing light effect resumes. In the embodiment shown in FIG. 9, the battery 33 powers the light circuit 60 during the night to produce light of varying colours and the user can optionally select a desired colour by pushing the push button 65. A selected colour is retained by memory in the IC 61. The memory may be a switch. Whilst the battery is powering the light circuit 60, the fourth capacitor 57 stores charge. As stated above, it is desirable for a selected colour to be retained and displayed on successive nights. As the battery 33 discharges, the output voltage of the battery 33 decreases. When the output voltage of the battery 33 is less than the stored voltage of the capacitor 57, the capacitor 57 discharges. Due to the presence and arrangement of the diodes 56 and 59, the capacitor 57 discharges through the light circuit 60. The IC 61 preferably includes a cut-off circuit that is voltage dependent. As the capacitor 57 discharges, the voltage across the cut-off circuit decreases. Once the voltage across the cut-off circuit reaches a predetermined threshold value, the cut-off circuit prevents further power being consumed by the LEDs. As no power is being consumed by the light circuit 60, the capacitor 57 retains a residual charge. The residual charge maintains a voltage across the IC 60, which enables the selected colour to be retained by the memory in the IC 61. During the next day, the solar cell 30 recharges the battery 33. As night falls, the resistance of resistor 42 again increases and the battery 33 provides sufficient power to the light circuit 60 to increase the voltage across the cut-off circuit above the predetermined threshold value. The LEDs are activated and the selected colour, as retained in the memory of the IC 61, is displayed. The voltage provided by the battery 33 is more than the stored charge of the fourth capacitor 57, so the capacitor 57 again begins to store charge. It will be readily apparent to a person skilled in the art that there are many circuit variations possible for enabling and controlling the lighting display, without departing from the spirit and scope of the invention. The switch 40 and/or switch 65 is/are mounted on the base 26 so as to be on a downwardly facing external surface 72 of the base 26. This enables a user to control the device via readily accessible switches, without needing to remove the cap assembly 24. The switches 40 and 65 are each operable to control delivery of electric power from the batteries to the LEDs 34A, 34B and 34C. The circuit 29 is only rendered operative when there is insufficient light, that is by operation of a light sensitive switch, ie the diode 42. The embodiment of FIG. 10 includes an ornamental garden light 73 having a body or base 74. The base 74 would be at least partly hollow so as to contain the circuitry of FIG. 9, except for the solar cell 30. The solar cell 30 would be mounted so as to be exposed to sunlight. The switches 40 and 65 would be mounted at an external surface of the base 74. The switch 40 and/or switch 65 would be mounted on an external surface of the base 74, while the diode 42 would be exposed to sunlight. The base 74 includes a spherical lens 75 secured to a horizontal portion 76 of the base 74. The horizontal portion 76 would have mounted in it the LEDs 34A, 34B and 34C so as to deliver light to the interior of the lens 75. | <SOH> BACKGROUND OF THE INVENTION <EOH>Light devices that employ light emitting diode (LED) systems to produce a variable colour are known. Examples are described in U.S. Pat. Nos.6,459,919, 6,608,458, 6,150,774 and 6,016,038. It is also known to have “garden lights” that are solar powered. For example such garden lights include a body providing a spike that is driven into a ground surface. At the upper end of the spike there is mounted a diffuser surrounding a lamp, with the lamp being driven by rechargeable batteries and a solar cell. The abovementioned lighting apparatus have a number of disadvantages including difficulty in adjusting the various lighting functions and not producing a uniform desired colour when required to do so. | <SOH> SUMMARY OF THE INVENTION <EOH>There is disclosed herein a lighting device to produce light of varying colour, said device including: a body; a lens mounted on the body and generally enclosing a chamber having an upper rim surrounding a top opening, and a bottom region; a reflector mounted in the bottom region; a cap assembly including securing means to releasably engage the rim so that the cap assembly can be selectively removed from the lens; said assembly including: a base; a circuit having at least two lamps of different colours which are activated to produce a desired colour including a varying colour, the lamps being mounted to direct light into said chamber, a solar cell mounted on an exposed surface of the assembly and rechargeable batteries to power the circuit, a light sub-circuit connected to the lamps to deliver electric power thereto so that the lamps produce said desired colour, and a switch operable to deliver electric power from the batteries and cell to said sub-circuit, the switch being exposed to provide for access thereto by a user. Preferably, said circuit includes a light sensitive switch that renders the circuit operation at low light levels. Preferably, said switch is on an exposed downwardly facing surface. Preferably, said circuit includes three lamps, each of a different colour. Preferably, said lens is a first lens, and said device includes a second lens, said second lens being attached to said base and providing a cavity into which the LEDs direct light, with the light leaving said second lens then passing through said first lens. Preferably, the first and second lenses diffuse light. Preferably, said body includes a post having opposite first and second ends, with a spike attached to said first end, and said first lens attached to said second end. Preferably, said second lens is detachably secured to said post. Preferably, said switch is a first switch, and second sub-circuit includes an integrated circuit and a second switch connected to said integrated circuit, the second switch being exposed to provide for access thereto by a user. Preferably, said second switch activates said integrated circuit to select a desired colour. Preferably, said second switch is on said exposed surface. There is further disclosed herein a lighting device to produce light of varying colour, said device including: a body; a lens mounted on the body and generally enclosing a chamber; a circuit having at least two lamps of different colours to produce a desired colour including a varying colour, the lamps being mounted to direct light into said chamber, connections for at least one rechargeable battery to power the circuit and a solar cell mounted on an exposed surface of the assembly and operatively associated with the connections to charge the battery, and a switch operated to control delivery of electric power from the battery to operate said circuit, the switch being exposed to provide for access thereto by a user. Preferably, said circuit includes a light sensitive switch that renders the circuit operative at low light levels. Preferably, said circuit includes a light sub-circuit connected to the lamps to deliver electric power thereto so that the lamps produce said desired colour, with said switch being an on/off switch to deliver electric power from the batteries to said sub-circuit. Preferably, said circuit includes a light sub-circuit having an integrated circuit operable to select a desired fixed colour, with said switch being connected to said integrated circuit and operable to select said desired fixed colour. Preferably, said circuit includes a sub-circuit, said switch is a first switch said first switch being an on/off switch to deliver electric power from the battery to said sub-circuit, and said sub-circuit includes an integrated circuit and a second switch connected to said integrated circuit, the second switch being operable to select a desired fixed colour and exposed to provide for access thereto by a user. Preferably, said second switch is on said exposed external surface. | 20040226 | 20070327 | 20050623 | 94315.0 | 61 | A, MINH D | SOLAR POWERED LIGHT ASSEMBLY TO PRODUCE LIGHT OF VARYING COLOURS | SMALL | 0 | ACCEPTED | 2,004 |
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10,789,532 | ACCEPTED | Interpolative varactor voltage controlled oscillator with constant modulation sensitivity | A tunable oscillator having a tuning voltage input includes an inductor, and first and second varactor pairs arranged with the inductor to generate a signal having a frequency responsive to a tuning voltage applied to the tuning voltage input, each of the varactor pairs having a bias voltage input that may be controlled independently of the other varactor pair. The first varactor pair may be biased such that its capacitance varies substantially linearly with the tuning voltage over a first portion of the tuning range, and the second varactor pair may be biased such that its capacitance varies substantially linearly with the tuning voltage over a second portion of the tuning range. | 1. A tunable oscillator having a tuning voltage input, comprising: an inductor; and first and second varactor pairs arranged with the inductor to generate a signal having a frequency responsive to a tuning voltage applied to the tuning voltage input, each of the varactor pairs having a bias voltage input that may be controlled independently of the other varactor pair. 2. The tunable oscillator of claim 1 wherein the each of the varactor pairs comprises two serially coupled varactors each having a first node coupled to the tuning voltage input and a second node coupled to its respective bias voltage input. 3. The tunable oscillator of claim 2 wherein each of the varactors comprises a MOSFET having a gate, a drain, and a source connected to the drain, and wherein the first node of the varactor comprises the gate and the second node of the varactor comprises the drain and source connection. 4. The tunable oscillator of claim 2 further comprising a first resistor coupled between the tuning voltage input and the first node of a first one of the varactors in each of the varactor pairs, and a second resistor coupled between the tuning voltage input and the first node of a second one of the varactors in each of the varactor pairs. 5. The tunable oscillator of claim 2 further comprising a first capacitor coupled between a first node of the inductor and the first node of a first one of the varactors in each of the varactor pairs, and a second capacitor coupled between a second node of the inductor and the first node of a second one of the varactors in each of the varactor pairs. 6. The tunable oscillator of claim 1 further comprising an input current source to the inductor and the first and second varactor pairs. 7. The tunable oscillator of claim 6 wherein the input current source comprises a constant current source coupled to a pair of cross-coupled transistors. 8. The tunable oscillator of claim 1 further comprising a differential-to-single ended amplifier having a differential input coupled across the inductor. 9. A tunable oscillator having a tuning range, comprising: an inductor; and first and second varactor pairs arranged with the inductor to generate a signal having a frequency responsive to a tuning voltage, wherein the first varactor pair is biased such that its capacitance varies substantially linearly with the tuning voltage over a first portion of the tuning range, and the second varactor pair is biased such that its capacitance varies substantially linearly with the tuning voltage over a second portion of the tuning range. 10. The tunable oscillator of claim 9 wherein the each of the varactor pairs comprises two serially coupled varactors each having a first node configured to receive the tuning voltage and a second node, each of the varactor pairs being biased at the second node of its respective varactors. 11. The tunable oscillator of claim 10 wherein each of the varactors comprises a MOSFET having a gate, a drain, and a source connected to the drain, and wherein the first node of the varactor comprises the gate and the second node of the varactor comprises the drain and source connection. 12. The tunable oscillator of claim 10 further comprising first and second resistors, the first node of a first one of the varactors in each of the varactor pairs being configured to receive the tuning voltage through the first resistor, and the first node of a second one of the varactors in each of the varactor pairs being configured to receive the tuning voltage through the second resistor. 13. The tunable oscillator of claim 10 further comprising a first capacitor coupled between a first node of the inductor and the first node of a first one of the varactors in each of the varactor pairs, and a second capacitor coupled between a second node of the inductor and the first node of a second one of the varactors in each of the varactor pairs. 14. The tunable oscillator of claim 9 wherein the first varactor pair is biased at approximately 1 volt when power is applied, and the second varactor pair is biased at approximately 2 volts when power is applied. 15. The tunable oscillator of claim 9 wherein the first portion of the tuning range is about 0.4 volts to about 1.4 volts when power is applied, and the second portion of the tuning range is about 1.1 volts to about 2.4 volts when power is applied. 16. A phase locked loop, comprising: a tunable oscillator having an inductor, and first and second varactor pairs arranged with the inductor to generate a signal having a frequency responsive to a tuning voltage, each of the varactor pairs having a bias voltage input that may be controlled independently of the other varactor pair; a divider configured to scale the signal frequency from the tunable oscillator; a phase detector configured to generate an error signal representative of a phase difference between the scaled signal frequency and a reference frequency; and a loop filter configured to filter the error signal, the filtered error signal comprising the tuning voltage. | BACKGROUND 1. Field The present disclosure relates generally to tunable oscillator circuits. More particularly, the disclosure relates to a tunable voltage controlled oscillator (VCO) circuit with a relatively constant modulation sensitivity over a wide tuning range. 2. Background Oscillators are used as stable frequency sources in diverse electronic applications. By way of example, in communication systems, oscillators are often used to provide a stable frequency reference signal for translating information signals to a desired frequency band. In conventional multi-channel communication systems, circuit arrangements employing multiple oscillators may be used to provide a selectable frequency source. This approach is generally used for high speed switching applications. For less critical applications, a more economical approach entails the use of a tunable oscillator circuit comprising a voltage controlled oscillator which can be phased locked to a frequency reference signal. In conventional VCO designs, varactors (variable capacitors) may be used for frequency tunability. In typical VCO designs, a controlled voltage determines the varactor capacitance which in turn determines the VCO output frequency. The varactors are typically biased around the center of the VCO's frequency tuning range. The frequency tuning characteristics of a typical varactor has two regions: a) a steep capacitance versus voltage slope for certain voltages and b) a saturated capacitance for other voltages. The steep capacitance versus voltage region of the curve may yield increased output phase noise. For example, a small noise voltage at the controlled voltage input causes a relatively large capacitance variation and therefore a noticeable undesired VCO phase noise due to the high sensitivity of the steep curve region. The saturation region of the capacitance versus voltage curve may yield a limited frequency tuning range such that voltages beyond a particular voltage threshold will have very little effect in changing the total capacitance and therefore the VCO output frequency. For example, in one typical design, the frequency tuning range of the VCO is approximately 2 volts (0.4 volts to 2.3 volts), but any voltage higher than 1.6 volts will only minimally change the capacitance and therefore the VCO output frequency. Accordingly, it would be desirable to have VCO designs which have a wide frequency tuning range but with reduced output phase noise. SUMMARY In one aspect of the present invention, a tunable oscillator has a tuning voltage input. The tunable oscillator includes an inductor, and first and second varactor pairs arranged with the inductor to generate a signal having a frequency responsive to a tuning voltage applied to the tuning voltage input, each of the varactor pairs having a bias voltage input that may be controlled independently of the other varactor pair. In another aspect of the present invention, a tunable oscillator has a tuning range. The tunable oscillator includes an inductor, and first and second varactor pairs arranged with the inductor to generate a signal having a frequency responsive to a tuning voltage, wherein the first varactor pair is biased such that its capacitance varies substantially linearly with the tuning voltage over a first portion of the tuning range, and the second varactor pair is biased such that its capacitance varies substantially linearly with the tuning voltage over a second portion of the tuning range. In yet another aspect of the present invention, a phase locked loop includes a tunable oscillator having an inductor, and first and second varactor pairs arranged with the inductor to generate a signal having a frequency responsive to a tuning voltage, each of the varactor pairs having a bias voltage input that may be controlled independently of the other varactor pair, a divider configured to scale the signal frequency from the tunable oscillator, a phase detector configured to generate an error signal representative of a phase difference between the scaled signal frequency and a reference frequency, and a loop filter configured to filter the error signal, the filtered error signal comprising the tuning voltage. It is understood that other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein it is shown and described various embodiments of the invention by way of illustration. As will be realized, the invention is capable of other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive. BRIEF DESCRIPTION OF THE DRAWINGS Aspects of the present invention are illustrated by way of example, and not by way of limitation, in the accompanying drawings, wherein: FIG. 1 is a schematic diagram of the tuning circuit of a VCO. FIG. 2 illustrates two graphs: first, a graph of a conventional VCO varactor capacitance versus tuning voltage curve; and second, a graph of a VCO varactor capacitance versus tuning voltage curve in accordance with the tuning circuit of FIG. 1. FIG. 3 illustrates two graphs, each graph representing the individual capacitance versus tuning voltage curves of the two constituent VCO varactor pairs in accordance with the tuning circuit of FIG. 1. FIG. 4 illustrates four graphs: first, a graph of the modulation sensitivity Kv of a conventional VCO; second, two similar graphs of the modulation sensitivity Kv of the two constituent VCO varactor pairs in accordance with the tuning circuit of FIG. 1; and third, a graph of the modulation sensitivity K, of the superposition of the two constituent VCO varactor pairs in accordance with the tuning circuit of FIG. 1. FIG. 5 is a schematic diagram of the VCO of the present invention showing the VCO tuning circuit and other circuits associated with the input current circuit and output amplifier of the VCO. FIG. 6 is a block diagram of a VCO operating in a phase locked loop. DETAILED DESCRIPTION The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced. Each embodiment described in this disclosure is provided merely as an example or illustration of the present invention, and should not necessarily be construed as preferred or advantageous over other embodiments. The detailed description includes specific details for the purpose of providing a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the present invention. Acronyms and other descriptive terminology may be used merely for convenience and clarity and are not intended to limit the scope of the invention. In addition, for the purposes of this disclosure, the term “coupled” means “connected to” and such connection can either be direct or, where appropriate in the context, can be indirect, e.g., through intervening or intermediary devices or other means. FIG. 1 is a schematic diagram of the VCO tuning circuit 100 of VCO 10. The VCO tuning circuit 100 allows the VCO 10 to have a wide frequency tuning range without significantly increasing output phase noise. In one embodiment, the VCO tuning circuit 100 includes two varactor pairs 110, 120, two resistors 130, 135, two capacitors 140, 145 and an inductor 150. A tuning voltage may be applied to the two varactor pairs 110 (VC1, VC2) and 120 (VC3, VC4) through the two resistors 130, 135. The resistors 130, 135 may be used to create a high impedance input so that the tuning voltage is not loaded down by the VCO 10. One skilled in the art would understand that any high impedance path may be used in place of resistors 130, 135. The two capacitors 140, 145 (which are DC blocking capacitors) may be used to prevent current from being injected into the VCO 10 from the tuning voltage source. One skilled in the art would understand that any DC blocking path may be used in place of capacitors 140, 145. Additionally, in one embodiment, each of the varactor pairs 110, 120 may include a bias voltage (Vcm1, Vcm2). The bias voltage can be chosen to adjust capacitance over voltage characteristic of the varactor pairs 110, 120. In one embodiment, each of the varactors (VC1, VC2, VC3, VC4) may be implemented with a metal oxide semiconductor field effect transistor (MOSFET) having its drain tied its source. Each of the varactor pairs 110, 120, may comprise two MOSFETs connected in series at the drain-source connection. Each of the varactors pairs 110, 120 may be biased by applying a voltage to the common drain-source connection. The tuning voltage may be applied to the gate of each MOSFET through respective input resistors 130, 135. Since the VCO frequency depends inversely on the square root of the product of inductance and varactor capacitance, and since the inductance of inductor 150 is fixed, then as the capacitance of the varactors (VC1, VC2, VC3, VC4) is varied by the applied tuning voltage, the VCO frequency will vary accordingly. FIG. 2 illustrates two graphs: graph 2a is a graph of a conventional VCO varactor capacitance versus tuning voltage curve, and graph 2b is a graph of the VCO varactor capacitance versus tuning voltage curve in accordance with the embodiment shown in FIG. 1. In graph 2a of FIG. 2, at the lower tuning voltages, the capacitance is approximately linearly proportional to the tuning voltage. However, at tuning voltages greater than approximately 1.6 volts, the capacitance saturates as voltage increases, decreasing the tunability of the VCO 10. In contrast, implementing the two varactor pairs 110, 120 into the VCO tuning circuit 100 yields a VCO varactor capacitance versus tuning voltage curve that remains approximately linear for a wider tuning voltage range, as shown in graph 2b of FIG. 2. Thus, as shown by the characteristic of graph 2b of FIG. 2, the varactor capacitance will change proportionally to the changing VCO tuning voltage for a wider tuning voltage range. FIG. 3 illustrates two graphs, each graph representing the individual capacitance versus tuning voltage curves of the two constituent VCO varactor pairs 110, 120. Graph 3a of FIG. 3 corresponds to the VCO varactor pair 110 while graph 3b of FIG. 3 corresponds to the VCO varactor pair 120. In graph 3a of FIG. 3, the varactor capacitance of varactor pair 110 is linearly proportional to the lower tuning voltage range of approximately 0.4 to 1.4 volts. Complimenting the linear characteristic shown in graph 3a, graph 3b of FIG. 3 shows that the varactor capacitance is linearly proportional to the higher tuning voltage range of approximately 1.1 to 2.4 volts. By implementing the two varactor pairs 110, 120 in the VCO tuning circuit 100 (shown in FIG. 1), their constituent linear characteristics at the lower tuning voltages and at the higher tuning voltages are combined, resulting in a capacitance characteristic that is linearly proportional to a wider tuning voltage range of 0.4 to 2.4 volts as illustrated in graph 2b of FIG. 2. One skilled in the art would understand that the stated tuning voltage values are presented for illustration only, and that other tuning voltage values may be used without departing from the spirit of the invention. FIG. 4 illustrates four graphs: graph 4a is a graph of the modulation sensitivity Kv of the conventional VCO; graph 4b and 4c are two similar graphs of the modulation sensitivity Kv of the two constituent VCO varactor pairs in accordance with the embodiment of FIG. 1; graph 4d is a graph of the modulation sensitivity Kv of the superposition of the two constituent VCO varactor pairs in accordance with the embodiment of FIG. 1. Modulation sensitivity Kv is defined as the incremental change of the varactor capacitance per incremental change of tuning voltage (i.e., the instantaneous slope of the curves presented in graphs 2a and 2b of FIG. 2). In graph 4a of FIG. 4, the peak value of the modulation sensitivity Kv for a conventional VCO tuning circuit is relatively high which results in increased susceptibility to undesired input noise, causing increased output phase noise. Additionally, its usable tuning range is limited to a portion of the desired tuning voltage range as shown by its rapid drop-off at approximately 1.6 volts. In contrast, graph 4d of FIG. 4 illustrates a near constant modulation sensitivity Kv of the two varactor pairs 110, 120 over the entire tuning voltage range (0.4 to 2.4 volts). The near constant modulation sensitivity Kv characteristic yields a wider tuning voltage range. In addition, since the constant modulation sensitivity Kv value is relatively smaller than in graph 4a, the susceptibility to input noise is reduced, causing a reduction in output phase noise. One skilled in the art would understand that the particular characteristics (such as, but not limited, to the drop-off value and tuning voltage range) of the modulation sensitivity Kv is given as an example for illustrative purposes only. Although FIG. 1 shows only two varactor pairs, multiple cascading varactor pairs, each pair with different and complimenting bias values, may be implemented into the VCO tuning circuit 100 without violating the spirit of the present invention. Multiple cascading varactor pairs may be used to increase the tuning voltage range beyond that of the tuning voltage range of using only two varactor pairs. By implementing the multiple cascading varactor pairs in the VCO tuning circuit 100, the constituent linear characteristics of each varactor pair at the different tuning voltage ranges may result in a capacitance characteristic that is linearly proportional to an even wider tuning voltage range than that of implementing two varactor pairs. Additionally, multiple cascading varactor pairs may be implemented to keep the VCO susceptibility to input noise at a minimum and thus minimizing the output phase noise. FIG. 5 is a schematic diagram of the VCO 10 showing the VCO tuning circuit 100 and other circuits associated with the input current circuit 510 and output amplifying circuit 580 of the VCO 10. The input current circuit 510 supplies current to the VCO tuning circuit 100 of the VCO 10. In one embodiment, the input current circuit 510 includes a constant current source 520 and a pair of cross-coupled transistors 530, 535 to inject current into the VCO tuning circuit 100. One skilled in the art would understand that alternatives to the input current circuit, such as, but not limited to, a voltage source could be used without violating the spirit of the present invention. The output amplifying circuit 580 shown in FIG. 5 amplifies a low-level VCO waveform to generate a VCO output waveform to be outputted by the VCO. In one embodiment, the output amplifying circuit 580 includes a differential-to-single ended amplifier. One skilled in the art would understand that other types of amplifiers could be used within the spirit of the present invention. The VCO 10 described thus far may be used in any application that requires a tunable oscillator. For the puroses of clarity and completeness, one such application will be discussed below in connection with a phase lock loop. FIG. 6 is a block diagram of a phase locked loop circuit 600 using the VCO 10. In one embodiment, the phase locked loop circuit 600 includes the VCO 10, a phase detector 610, a loop filter 620 and a divider 630. The phase locked loop circuit 600 uses feedback to lock the VCO 10 to a reference frequency Fin (usually generated by a highly stable crystal oscillator). The output of the VCO 10 is typically connected to a coupler that directs a portion of the VCO output waveform to the feedback loop that connects to an input of the phase detector 610. The remainder of the VCO output waveform is applied to and consumed by an external load. The frequency of the VCO output waveform is usually an integer multiple of the reference frequency Fin. The portion of the output waveform from the VCO 10, which is directed to the feedback loop, may be provided to the divider 630 before being applied to the phase detector 610. The divider 630 scales the frequency of the VCO output waveform to generate a frequency-scaled VCO output waveform in accordance with the reference frequency and the desired operating frequency of the VCO 10. In one embodiment, the divider 630 may be implemented with a programmable frequency scale factor N which is the ratio of the desired VCO output frequency to the reference frequency Fin. For example, if the reference frequency Fin is 100 MHz and the VCO 10 operates at 200 MHz, a divide-by-two divider 630 would be used. The phase detector 610 compares the reference waveform with reference frequency Fin to the frequency-scaled VCO output waveform to record their phase difference. The phase detector 610 generates a phase detector output signal with a DC component which is proportional to the phase difference between the reference waveform and the frequency-scaled VCO output waveform. In one embodiment, the loop filter 620 filters out the other undesired noise components of the phase detector output signal. The DC component, which may be referred to as an “error signal,” may then be applied to the tuning input of the VCO 10 to adjust the frequency of the VCO output waveform to the desired integer multiple of the reference frequency Fin. The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. | <SOH> BACKGROUND <EOH>1. Field The present disclosure relates generally to tunable oscillator circuits. More particularly, the disclosure relates to a tunable voltage controlled oscillator (VCO) circuit with a relatively constant modulation sensitivity over a wide tuning range. 2. Background Oscillators are used as stable frequency sources in diverse electronic applications. By way of example, in communication systems, oscillators are often used to provide a stable frequency reference signal for translating information signals to a desired frequency band. In conventional multi-channel communication systems, circuit arrangements employing multiple oscillators may be used to provide a selectable frequency source. This approach is generally used for high speed switching applications. For less critical applications, a more economical approach entails the use of a tunable oscillator circuit comprising a voltage controlled oscillator which can be phased locked to a frequency reference signal. In conventional VCO designs, varactors (variable capacitors) may be used for frequency tunability. In typical VCO designs, a controlled voltage determines the varactor capacitance which in turn determines the VCO output frequency. The varactors are typically biased around the center of the VCO's frequency tuning range. The frequency tuning characteristics of a typical varactor has two regions: a) a steep capacitance versus voltage slope for certain voltages and b) a saturated capacitance for other voltages. The steep capacitance versus voltage region of the curve may yield increased output phase noise. For example, a small noise voltage at the controlled voltage input causes a relatively large capacitance variation and therefore a noticeable undesired VCO phase noise due to the high sensitivity of the steep curve region. The saturation region of the capacitance versus voltage curve may yield a limited frequency tuning range such that voltages beyond a particular voltage threshold will have very little effect in changing the total capacitance and therefore the VCO output frequency. For example, in one typical design, the frequency tuning range of the VCO is approximately 2 volts (0.4 volts to 2.3 volts), but any voltage higher than 1.6 volts will only minimally change the capacitance and therefore the VCO output frequency. Accordingly, it would be desirable to have VCO designs which have a wide frequency tuning range but with reduced output phase noise. | <SOH> SUMMARY <EOH>In one aspect of the present invention, a tunable oscillator has a tuning voltage input. The tunable oscillator includes an inductor, and first and second varactor pairs arranged with the inductor to generate a signal having a frequency responsive to a tuning voltage applied to the tuning voltage input, each of the varactor pairs having a bias voltage input that may be controlled independently of the other varactor pair. In another aspect of the present invention, a tunable oscillator has a tuning range. The tunable oscillator includes an inductor, and first and second varactor pairs arranged with the inductor to generate a signal having a frequency responsive to a tuning voltage, wherein the first varactor pair is biased such that its capacitance varies substantially linearly with the tuning voltage over a first portion of the tuning range, and the second varactor pair is biased such that its capacitance varies substantially linearly with the tuning voltage over a second portion of the tuning range. In yet another aspect of the present invention, a phase locked loop includes a tunable oscillator having an inductor, and first and second varactor pairs arranged with the inductor to generate a signal having a frequency responsive to a tuning voltage, each of the varactor pairs having a bias voltage input that may be controlled independently of the other varactor pair, a divider configured to scale the signal frequency from the tunable oscillator, a phase detector configured to generate an error signal representative of a phase difference between the scaled signal frequency and a reference frequency, and a loop filter configured to filter the error signal, the filtered error signal comprising the tuning voltage. It is understood that other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein it is shown and described various embodiments of the invention by way of illustration. As will be realized, the invention is capable of other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive. | 20040227 | 20061031 | 20050901 | 58719.0 | 0 | KINKEAD, ARNOLD M | INTERPOLATIVE VARACTOR VOLTAGE CONTROLLED OSCILLATOR WITH CONSTANT MODULATION SENSITIVITY | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,789,677 | ACCEPTED | Torsion spring activated round bale kicker | A bale kicker for a round baler that employs an adjustable torsion bar, or bars, to impart a rearward force to an exiting bale to ensure that the completed bale is clear of the baler. | 1. In a round baler for movement across the ground and formation of cylindrical bales of crop material, the baler having a frame with a front end and an opposing rear end, a wheel assembly including a transverse axle part of and supporting the frame, a bale-forming chamber supported on the frame and including a forward portion and a tailgate vertically pivotable between a closed position for forming round bales and an open position for bale ejection, a bale kicker generally vertically pivotably connected to the frame for contacting a bale during its ejection from the bale-forming chamber and for propelling it rearwardly of the baler, the improvement comprising: the bale kicker including: a generally flat table-like ramp affixed to the axle for generally free vertical pivotal movement between a closed position where it is approximately horizontal or slightly above horizontal, and an open position where it is below horizontal, generally in contact with the ground; and a first generally transverse torsion bar with a longitudinal axis generally parallel to the transverse axle and having a first end affixed to the axle, and an opposing second end affixed to the ramp, such that movement of the table between the closed position and the open position imparts a twist to the torsion bar that provides a kick to the ejected bale as it moves off the ramp onto the ground. 2. The improvement of claim 1, wherein: the torsion bar has a multifaceted portion on each of the first and second ends; an axle bracket is rigidly affixed to the axle and extends generally rearwardly away therefrom; the axle bracket has a hole therethrough matching the multifaceted shape of the first end of the torsion bar, and the first end of the torsion bar extends through the hole in the axle bracket, whereby pivotal movement of the ramp from the closed position toward the open position imparts a twist to the torsion bar. 3. The improvement of claim 2, wherein: the second end of the torsion bar is affixed to the ramp by an elongate coupler that has a first end and an opposing second end; the coupler has a hole therethrough adjacent the first end of the coupler matching the multifaceted shape on the second end of the torsion bar and the second end of the torsion bar extends through the hold in the coupler; the second end of the coupler connected to the ramp to allow the table to pivot between the closed position and the open position and impart a twist to the torsion bar. 4. The improvement of claim 3, wherein: the ramp is generally U-shaped with the parallel arms thereof pivotally affixed to the axle. 5. The improvement of claim 4, wherein: the torsion bar is generally located between the parallel arms of the U-shaped ramp. 6. The improvement of claim 3, wherein: the kicker includes a second torsion bar, and the first and second torsion bars are axially aligned. 7. In a round baler for movement across the ground and formation of cylindrical bales of crop material, the baler having a frame with a front end and an opposing rear end, a wheel assembly including a transverse axle part of and supporting the frame, a bale-forming chamber supported on the frame and including a forward portion and a tailgate vertically pivotable between a closed position for forming round bales and an open position for bale ejection, a bale kicker generally vertically pivotably connected to the frame for contacting a bale during its ejection from the bale-forming chamber and for propelling it rearwardly of the baler, the improvement comprising: the bale kicker including: a generally flat table-like ramp affixed to the axle for generally free vertical pivotal movement between a closed position where it is approximately horizontal or slightly above horizontal, and an open position where it is below horizontal, generally in contact with the ground; and first and second generally transverse torsion bars with aligned longitudinal axes generally parallel to the transverse axle, each having a first end affixed to the axle, and an opposing second end affixed to the ramp, such that movement of the table between the closed position and the open position imparts a twist to the torsion bars that provides a kick to the ejected bale as it moves off the ramp onto the ground. 8. The improvement of claim 7, wherein: each of the second ends of the torsion bars is affixed to the ramp by respective elongate couplers that have first ends and opposing second ends; the coupler has a hole therethrough adjacent the first end of the coupler matching the multifaceted shape on the second ends of the torsion bars and the second ends of the torsion bars extends through the hold in the coupler; the second ends of the couplers are connected to the ramp to allow the table to pivot between the closed position and the open position and impart a twist to the torsion bar. 9. The improvement of claim 8, wherein: the ramp is generally U-shaped with the parallel arms thereof pivotally affixed to the axle. 10. The improvement of claim 9, wherein: the first and second torsion bars are generally located between the parallel arms of the U-shaped ramp. 11. A round baler for movement across the ground and formation of cylindrical bales of crop material, the baler comprising: a frame with a front end and an opposing rear end; a wheel assembly including a transverse axle part of and supporting the frame; a bale-forming chamber supported on the frame and including a forward portion and a tailgate vertically pivotable between a closed position for forming round bales and an open position for bale ejection; a bale kicker generally vertically pivotably connected to the frame for contacting a bale during its ejection from the bale-forming chamber and for propelling it rearwardly of the baler, the bale kicker comprising: a generally flat table-like ramp affixed to the axle for generally free vertical pivotal movement between a closed position where it is approximately horizontal or slightly above horizontal, and an open position where it is below horizontal, generally in contact with the ground; and a first generally transverse torsion bar with a longitudinal axis generally parallel to the transverse axle and having a first end affixed to the axle, and an opposing second end affixed to the ramp, such that movement of the table between the closed position and the open position imparts a twist to the torsion bar that provides a kick to the ejected bale as it moves off the ramp onto the ground. 12. The round baler of claim 11, wherein: the torsion bar has a multifaceted portion on each of the first and second ends; an axle bracket is rigidly affixed to the axle and extends generally rearwardly away therefrom; the axle bracket has a hole therethrough matching the multifaceted shape of the first end of the torsion bar, and the first end of the torsion bar extends through the hole in the axle bracket, whereby pivotal movement of the ramp from the closed position toward the open position imparts a twist to the torsion bar. 13. The round baler of claim 12, wherein: the second end of the torsion bar is affixed to the ramp by an elongate coupler that has a first end and an opposing second end; the coupler has a hole therethrough adjacent the first end of the coupler matching the multifaceted shape on the second end of the torsion bar and the second end of the torsion bar extends through the hold in the coupler; the second end of the coupler connected to the ramp to allow the table to pivot between the closed position and the open position and impart a twist to the torsion bar. 14. The round baler of claim 13, wherein: the kicker includes a second torsion bar, and the first and second torsion bars are axially aligned. 15. A round baler for movement across the ground and formation of cylindrical bales of crop material comprising: a frame with a front end and an opposing rear end; a wheel assembly including a transverse axle part of and supporting the frame; a bale-forming chamber supported on the frame and including a forward portion and a tailgate vertically pivotable between a closed position for forming round bales and an open position for bale ejection; a bale kicker generally vertically pivotably connected to the frame for contacting a bale during its ejection from the bale-forming chamber and for propelling it rearwardly of the baler, the kicker comprising: a generally flat table-like ramp affixed to the axle for generally free vertical pivotal movement between a closed position where it is approximately horizontal or slightly above horizontal, and an open position where it is below horizontal, generally in contact with the ground; and first and second generally transverse torsion bars with aligned longitudinal axes generally parallel to the transverse axle, each having a first end affixed to the axle, and an opposing second end affixed to the ramp, such that movement of the table between the closed position and the open position imparts a twist to the torsion bars that provides a kick to the ejected bale as it moves off the ramp onto the ground. 16. The round baler of claim 15, wherein: each of the second ends of the torsion bars is affixed to the ramp by respective elongate couplers that have first ends and opposing second ends; the coupler has a hole therethrough adjacent the first end of the coupler matching the multifaceted shape on the second ends of the torsion bars and the second ends of the torsion bars extends through the hold in the coupler; the second ends of the couplers are connected to the ramp to allow the table to pivot between the closed position and the open position and impart a twist to the torsion bar. 17. The round baler of claim 16, wherein: the ramp is generally U-shaped with the parallel arms thereof pivotally affixed to the axle. 18. The round baler of claim 17, wherein: the first and second torsion bars are generally located between the parallel arms of the U-shaped ramp. | BACKGROUND OF THE INVENTION The present invention relates generally to round balers, and more particularly to a device on such machines for “kicking” bales as they exit the baler to assure that the bale is spaced from the baler. At the completion of the bale-forming cycle, most round balers open the rear portion of the bale-forming chamber, referred sometimes to the tailgate, and eject the bale onto the ground. If the tailgate is too close to the ejected bale, the tailgate cannot be closed, and entire baler must be moved ahead before starting the bale-formation process. The problem is that by moving the baler ahead without closing the tailgate, some crop is missed and thus left out of the process. Some balers use a pivotable ramp that directs the bale rearward upon ejection. Such designs are usually spring biased into the rest position. The problem with this design are that it does not work well when operating the baler on a downward incline, i.e., the bale does not roll away from the baler, but rather stops immediately or rolls back toward the baler. Bale kickers have been used on round balers for several years to push the finished bales rearwardly from the baler to provide the space necessary to close the tailgate and initiate the next baling process without having to move the baler and bypass crop material on the ground. U.S. Pat. No. 4,206,587 to Freimuth et al. shows several bale kickers that are pivotable between raised and lowered positions and biased by springs toward the raised position. Prior kickers, such as shown in Freimuth et al. and, for another example, U.S. Pat. No. 4,458,587 to Jennings, are fairly complex and thus costly additions to the basic baler. It would be quite beneficial to have a bale kicker that significantly reduces the complexity and cost of prior known bale kickers, and consistently provides the force necessary to push the bale an adequate distance away from the baler to allow effective and efficient operation of the baler in all kinds of operating conditions. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a bale kicker for round balers that uses a torsion bar, or bars, to provide impetus to the bale being ejected. Another object of the present invention is to provide a bale kicker that requires no operator intervention to ensure proper operation. It is another object of the instant invention to provide a bale kicker for a round baler that is more simplified in structure and reliable in us than previously known bale kickers. It is still another object of the instant invention to provide a bale kicker wherein the kicking force may be adjusted by simple steps. It is an even still further object of the instant invention to provide an improved bale kicker for a round baler that is durable in construction, inexpensive of manufacture, carefree of maintenance, facile in assemblage, and simple and effective to set up, adjust and use. These and other objects are attained by providing a bale kicker for a round baler that employs an adjustable torsion bar, or bars, to impart a rearward force to an exiting bale to ensure that the completed bale is clear of the baler. DESCRIPTION OF THE DRAWINGS The advantages of this invention will be apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein: FIG. 1 is a partial side elevational view of a round baler showing a side view of the bale kicker of the instant invention; FIG. 2 is a rear perspective view of one embodiment of the bale kicker of the instant invention; FIG. 3 is a top plan view of the bale kicker of FIG. 1; and FIG. 4 is a top plan view of a second embodiment of a kicker of the instant invention DESCRIPTION OF THE PREFERRED EMBODIMENT Many of the fastening, connection, processes and other means and components utilized in this invention are widely known and used in the field of the invention described, and their exact nature or type is not necessary for an understanding and use of the invention by a person skilled in the art, and they will not therefore be discussed in significant detail. Also, any reference herein to the terms “left” or “right” are used as a matter of mere convenience, and are determined by standing at the rear of the machine facing in its normal direction of travel. Furthermore, the various components shown or described herein for any specific application of this invention can be varied or altered as anticipated by this invention and the practice of a specific application of any element may already by widely known or used in the art by persons skilled in the art and each will likewise not therefore be discussed in significant detail. FIG. 1 shows a round baler 10 including a first embodiment of the present invention. Round baler 10 is of conventional design, many of which are well-known in the prior art. For example, U.S. Pat. No. 4,458,587 includes a fairly detailed description of a round baler to which the present invention could easily be adapted. The round baler 10 shown in FIG. 1 is a generalized presentation, most specific details being known in the art and unnecessary for a full understanding of the invention. Baler 10 has a main frame (not shown in detail) and a transverse axle 11 carrying a pair of wheels 12. In turn, the main frame supports a clam shell-like bale-forming chamber comprised of a fixed forward portion 14 and pivotable rearward tailgate 16. Inside the bale-forming chamber are the various belts, cams, etc. that form a bale, as at 18. The tailgate 16 is in the down, or closed, position during bale formation, and is hydraulically raised to the upper position, the position shown, for ejection of the completed bale. A crop pickup 20 moves the material to be baled from the field into the bale-forming chamber where it is incorporated into the bale. A tongue 22 is affixed to forward portion of the main frame for attachment to a tractor or other motive vehicle. The purpose of bale kicker 30 is to engage the completed bale as it is ejected from the baler and impart a rearward force thereto to ensure that the bale is clear of the rear of the baler when the tailgate 16 of the bale-forming chamber closes. Referring now to FIGS. 2 and 3, a first embodiment can be seen to comprise a generally flat ramp 32 with a pair of forwardly extending arms 34, 36. A pair of axle brackets 38, 40 affixed, as by welding for example, to axle 11 pivotably hold arms 34, 36, respectively, by bolts 42, 44. Bearings are included on bolts 42, 44 and spacers as required to maintain a stable pivotable connection. A torsion bar 50 is fixed to a support arm 52 which is, in turn, affixed to axle 11. Torsion bar 50 is formed with hex-shaped ends and support arm 52 has a hole therethrough 54 with a matching hex configuration so that one end of the torsion bar and support arm 52 remain in a fixed position. A coupler 56 interconnects the other end of torsion bar 50 and arm 36 such that movement of ramp 32 causes the torsion bar 50 to twist, thus winding the torsion bar and loading it with kinetic energy. The hex-shape of the end of the torsion bar 50 fits in a hex-shaped hole 58 in coupler 56 (like the other end). The coupler 56 is attached to arm 36 by bolt 60, with appropriate spacers. While the shape of the end of the torsion bar is identified as hex or hexagonal, it may be any multifaceted configuration, such as, as an additional example, octagonal, so long as the connections that it is part of are strong and non-slipping. In operation, round baler 10 is pulled across the field of mown crop material which is fed into the bale-forming chamber where the bale is formed. Upon completion of the formation process, the tailgate 16 of the bale chamber opens and the bale is ejected. As the bale exits, it drops onto ramp 32 of the bale kicker, causing it to rotate about bolts 42, 44, and inputting torsion on the torsion bar 50. The ramp, in the configuration shown in FIG. 1, moves approximately 35°, though it could be more or less in other configurations. As the bale continues its rearward movement, some of the weight is transferred to the ground (as the weight of the bale moves from the ramp to the ground) and when adequate weight is transferred to the ground, the tension in the torsion bar is released and it “kicks” the bale rearwardly. A second embodiment 69, using two axially-aligned shorter torsion bars 70, 71, of the invention is depicted in FIG. 4. In this configuration, ramp 32 is supported by the same axle brackets 38, 40 and arms 34, 36 as the embodiment of FIGS. 2 and 3, and each outside end of the respective torsion bars is held in position by supports 74, 76 in a manner similar to torsion bar 50 by support 52. The inside ends of the respective torsion bars are held in horizontal and vertical position by bracket 78 that is fixes to axle 11. The inside ends of torsion bars 70, 71 are free to rotate within bracket 78. A pair of support plates 80, 82, affixed to ramp 32, has a hex-shaped hole therethrough into which the respective hex-shaped torsion bar end is fixed, such that pivoting of ramp 32 puts tension into the torsion bars for providing the “kicking” force necessary to roll the bale away from the baler. The amount of the tension that the torsion bar(s) is allowed to temporarily absorb depends upon a number of variables. For instance, by careful selection of the diameter, cross-sectional shape, length and materials of the torsion bar, the dynamics of the bar itself can be changed. By adjusting the position of the table relative to horizontal in the rest, or unloaded condition, the amount of tension imparted to the torsion bar, and thus the force of the “kick”, can be adjusted. This could be accomplished in several ways; however, the simplest procedure would be to remove the torsion bar, raising or lowering the table to the desired position, then replacing the torsion bar to hold the table in the new position. Finally, the weight of the bale has a significant impact on the amount of force needed or desired to impart, and may require adjustment of the hardware. It will be understood that changes in the details, materials, steps and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the inventions. Accordingly, the following claims are intended to protect the invention broadly as well as in the specific form shown. | <SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates generally to round balers, and more particularly to a device on such machines for “kicking” bales as they exit the baler to assure that the bale is spaced from the baler. At the completion of the bale-forming cycle, most round balers open the rear portion of the bale-forming chamber, referred sometimes to the tailgate, and eject the bale onto the ground. If the tailgate is too close to the ejected bale, the tailgate cannot be closed, and entire baler must be moved ahead before starting the bale-formation process. The problem is that by moving the baler ahead without closing the tailgate, some crop is missed and thus left out of the process. Some balers use a pivotable ramp that directs the bale rearward upon ejection. Such designs are usually spring biased into the rest position. The problem with this design are that it does not work well when operating the baler on a downward incline, i.e., the bale does not roll away from the baler, but rather stops immediately or rolls back toward the baler. Bale kickers have been used on round balers for several years to push the finished bales rearwardly from the baler to provide the space necessary to close the tailgate and initiate the next baling process without having to move the baler and bypass crop material on the ground. U.S. Pat. No. 4,206,587 to Freimuth et al. shows several bale kickers that are pivotable between raised and lowered positions and biased by springs toward the raised position. Prior kickers, such as shown in Freimuth et al. and, for another example, U.S. Pat. No. 4,458,587 to Jennings, are fairly complex and thus costly additions to the basic baler. It would be quite beneficial to have a bale kicker that significantly reduces the complexity and cost of prior known bale kickers, and consistently provides the force necessary to push the bale an adequate distance away from the baler to allow effective and efficient operation of the baler in all kinds of operating conditions. | <SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, it is an object of the present invention to provide a bale kicker for round balers that uses a torsion bar, or bars, to provide impetus to the bale being ejected. Another object of the present invention is to provide a bale kicker that requires no operator intervention to ensure proper operation. It is another object of the instant invention to provide a bale kicker for a round baler that is more simplified in structure and reliable in us than previously known bale kickers. It is still another object of the instant invention to provide a bale kicker wherein the kicking force may be adjusted by simple steps. It is an even still further object of the instant invention to provide an improved bale kicker for a round baler that is durable in construction, inexpensive of manufacture, carefree of maintenance, facile in assemblage, and simple and effective to set up, adjust and use. These and other objects are attained by providing a bale kicker for a round baler that employs an adjustable torsion bar, or bars, to impart a rearward force to an exiting bale to ensure that the completed bale is clear of the baler. | 20040228 | 20060523 | 20050901 | 61131.0 | 0 | NGUYEN, JIMMY T | TORSION BAR ACTIVATED ROUND BALER KICKER | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,789,748 | ACCEPTED | Interchangeable fan assembly for cold-air inflatable displays | An inflatable display that has an interchangeable fan assembly in a position on the inflatable figure that allows optimum airflow into the display. One interchangeable fan assembly can be used for a plurality of inflatable figures by detaching the interchangeable fan assembly from the receiving opening on one figure and attaching it to the same on another figure with a compatible receiving opening. | 1. A cold-air inflatable display comprising: a permeable fabric forming a figure with a hollow body; an interchangeable fan assembly for continuously-blowing air into said hollow body, said fan assembly comprising at least one fan, a housing for said fan secured to a standard-sized fabric having a male securing device disposed along a border of said standard-sized fabric for receipt by a female securing device disposed along a border of a receiving opening joining said fan assembly to said permeable fabric through said receiving opening positioned on said hollow body to allow optimum airflow through said fan into said hollow body; a lighting arrangement extending through an interior portion of said hollow body, comprising a power cord, at least one light fixture, including a light bulb with a protective cover, secured to said power cord and an electrical connector disposed at an end of said power cord mating with a second electrical connector extending from said fan assembly; and a second power cord extending from said fan for connection to a power source. 2. The cold-air inflatable display of claim 1, further comprising three fans. 3. The cold-air inflatable display of claim 1, wherein said receiving opening has the same dimensions as the corresponding dimensions of said fan assembly. 4. The cold-air inflatable display of claim 1, further comprising a zipper system having a male securing zipper and a female securing zipper for joining said fan assembly to said permeable fabric. 5. The cold-air inflatable display of claim 1, wherein said fan assembly is positioned in a lower backside above a surface-touching bottom of said hollow body. 6. The cold-air inflatable display of claim 1, further comprising a fastening frame for securing said housing of said fan to said standard-sized fabric. 7. A cold-air inflatable display, comprising: a permeable fabric forming a figure with a hollow body; an interchangeable fan assembly for continuously-blowing air into said hollow body, said fan assembly comprising at least one fan, a housing for said fan, a securing device disposed along a border of said housing for joining said fan assembly to said permeable fabric through a receiving opening positioned on said hollow body above a surface-touching bottom of said hollow body; and a lighting arrangement extending through an interior portion of said hollow body, comprising a power cord connected to said fan and at least one lighting element secured to said power cord. 8. The cold-air inflatable display of claim 7, further comprising an electrical connector disposed at an end of said power cord mating with a second electrical connector extending from said fan assembly. 9. The cold-air inflatable display of claim 7, further comprising three fans. 10. The cold-air inflatable display of claim 7, wherein said receiving opening has the same dimensions as the corresponding dimensions of said fan assembly. 11. The cold-air inflatable display of claim 7, further comprising a zipper system having a male securing zipper and female securing zipper for joining said fan assembly to said permeable fabric. 12. The cold-air inflatable display of claim 7, further comprising a fastening frame for securing said housing of said fan to said standard-sized fabric. 13. A method for interchanging a fan assembly for cold-air inflatable displays, comprising: unfastening a border of an interchangeable fan assembly from a permeable fabric along a receiving opening of a first cold-air inflatable display; and removing an electrical connector extending from a fan of said interchangeable fan assembly from a second electrical connector of a power cord of a lighting arrangement of said first cold-air inflatable display; connecting said electrical connector to a second power cord of a second lighting arrangement of a second cold-air inflatable display; and fastening said border of said interchangeable fan assembly to a second permeable fabric along a second receiving opening of said second cold-air inflatable display. 14. The method of claim 13, wherein said unfastening step comprises unzipping a male securing zipper from a female securing zipper along said receiving opening and said fastening step comprises zipping said male securing zipper together with a second female securing zipper along a second receiving opening. | FIELD OF THE INVENTION The apparatus and method of the present invention relate to cold-air displays that maintain their inflated state through the use of continuously blowing electric fans. BACKGROUND OF THE INVENTION Inflatable displays have become increasingly popular in recent years. These types of displays have a wide range of application, shape and size, including, but not limited to, figures for holiday and seasonal decoration, marketing, advertising, entertainment, and event attraction. The inflatable displays are made from a permeable fabric that allows air to pass through the fabric at approximately the same rate as the air being blown into the inflatable display. The process of continuously blowing air being supplied from the fan occurring at substantially the same rate as air escaping the fabric allows the display to maintain its three-dimensional shape without the use of an internal or external frame or structure. These are known in the industry as “cold-air” inflatable displays. Because most of these displays require a significant amount of airflow from the fan to maintain their inflated state, the fan assembly has been rather large and heavy and has been positioned at the bottom of the inflatable display adjacent the ground for support. A typical fan utilized in prior cold-air inflatable displays has a motor winding with sleeves and bearings configuration. Prior cold-air inflatable displays house the fan within a base positioned at the bottom of the figure into which the fan circulates blown air. Since the base housing the fan rests adjacent the ground, certain measures must be taken by the operator in order to ensure sufficient airflow into the fan. Specifically, the base housing the fan must be positioned at a height far enough above the ground to allow sufficient air to enter the fan. Permanently affixed legs or removable legs secured to the base have been utilized to raise the base housing the fan at a sufficient level above the ground enabling a proper airflow into the fan. If the fan is disposed too close to the ground, the flow of air into the fan may be limited and the figure may not be inflated in the manner desired. Thus, unacceptable inflation of the figure may result because the fan is positioned too low to the ground, or because the legs of the base sink further into the ground after it has already been positioned, or because unwanted debris accumulate between the fan and the ground. The fan assemblies in prior inflatable displays also have been configured such that the fan assembly and/or the base which houses the fan are permanently affixed to the fabric of the inflatable figure in a variety of ways. For example, the fabric may be directly attached to the fan housing or base or secured to the fan housing or base via a fastening member. Further, because not all inflatable displays have the same shape on their bottom surfaces, the fan and base housing assemblies are unique for each type of display. Thus, in prior inflatable devices the fan assembly is a permanent component of each display. For example, if a consumer were to purchase a jack-o-lantern inflatable display for the Halloween season, a snowman inflatable display for the holiday season, and an Uncle Sam inflatable display for Independence Day, the consumer would be purchasing three complete packages of each inflatable figure, fan assembly, and other components. As the fan assembly is a significant cost component of inflatable devices, the lack of interchangeability between fan assemblies for different displays significantly increases the cost to purchasers of multiple inflatable devices. There is no present apparatus or method utilizing a fan assembly that is interchangeable with several different inflatable figure displays. SUMMARY OF THE INVENTION In the present invention, a cold-air inflatable display maintains its inflated state from one or more lightweight continuously blowing electric fan(s) positioned on the display in such a manner as to permit optimum airflow through the fan and into the display. The fan assembly is advantageously positioned on a lower portion of the display above the surface-touching bottom of the display so that the fan is elevated above the ground avoiding the problem of insufficient airflow into the display. This ensures that the airflow to the fan will not be limited preventing the fan from inflating the display with sufficient air pressure to properly maintain its shape. The positioning of the fan on a lower portion elevated above the ground further eliminates the need for a base housing for supporting the fan and legs for elevating the fan and base housing above the ground. The invention also includes an interchangeable fan assembly that can be utilized with multiple displays, thus reducing cost to purchasers and increasing their ability to enjoy the benefits of numerous inflatable displays. By affixing the fan assembly to a standard-sized piece of fabric that is detachable from one display and reattachable to another display by joining the male fastening device of the standard-sized piece of fabric with the female fastening device of the other display, a fan assembly can be incorporated and used with any given number of comparable displays. Since the fan assembly is not positioned on the surface-touching bottom of the display, there is no difficulty finding a specified location on the lower portion of each display that allows for a convenient location for the fan assembly ensuring optimum airflow into the display. It will be appreciated by those skilled in the art that the foregoing brief description and the following detailed description are exemplary and explanatory of this invention, but are not intended to be restrictive thereof or limiting of the advantages which can be achieved by this invention. Thus, the accompanying drawings, referred to herein and constituting a part hereof, illustrate preferred embodiments of this invention, and, together with the detailed description, serve to explain the principles of this invention. BRIEF DESCRIPTION OF THE DRAWINGS The features and advantages of the present invention, both as to its structure and operation, will be apparent from the following detailed description, especially when taken in conjunction with the accompanying drawings, wherein: FIG. 1 is a front perspective view of an inflatable display with an embodiment of the interchangeable fan assembly of the present invention; FIG. 2 is a back perspective view of an inflatable display with an embodiment of the interchangeable fan assembly of the present invention; FIG. 3 is an enlarged view of an embodiment of the interchangeable fan assembly of the present invention; FIG. 4 is an enlarged view of an embodiment of a fan unit of the interchangeable fan assembly; and FIG. 5 is a block diagram illustrating an embodiment of a fan assembly from one inflatable display being interchanged with alternative inflatable displays configured to receive the fan assembly. DETAILED DESCRIPTION OF THE INVENTION The apparatus and method of the present invention will now be discussed with reference to FIGS. 1, 2, 3, 4, and 5. Referring to FIGS. 1 and 2, inflatable display 10 includes interchangeable fan assembly 12, in this embodiment comprising three electric fans 13, female fastening device 24 for receiving said interchangeable fan assembly, interior lighting arrangement 21, and power source 17. The material of inflatable display 10 is preferably made from a permeable fabric that allows air to escape at approximately the same rate as air being blown into the inflatable display by said interchangeable fan assembly 12. Inflatable display 10, shown in this embodiment as a snowman, may be configured in any shape or size, depending on the specific need and purpose of the display. Inflatable display 10 is held in position by a securing mechanism, such as tether 27, that fastens to either the ground or another structure and is secured to said inflatable display by securing devices, such as securing ring 26 attached to inflatable display 10. Interior lighting arrangement 21 includes one or more light bulbs 22 secured to a power cord 28. Protective covers are secured around each light bulb to protect the permeable fabric of inflatable display 10 from heat produced from each bulb. Interior lighting arrangement 21 is attached to interchangeable fan assembly 12 through electrical connector 23 on the bottom end of power cord 28 that mates with electrical connector 18 of interchangeable fan assembly 12. When interchangeable fan assembly 12 is switched from one display to another, an operator detaches electrical connector 18 on interchangeable fan assembly 12 from electrical connector 23 on interior lighting arrangement 21. Referring now to FIGS. 3 and 4, interchangeable fan assembly 12 is comprised of one or more electric fans 13 connected to power source 17 and electrical connector 18. The housing of electric fan 13 is secured to standard-sized fabric 29 by fastening frame 15 sewn into standard-sized fabric 29. Fastening frame 15 borders the housing of electric fan 13 thereby securing the fan to standard-sized fabric 29 and holding the fan in place. Electric fan 13 is preferably a lightweight plastic sleeveless bearing fan. The lightweight of the electric fan assembly and the plastic housing enables the fan assembly to be secured to the fabric of the inflatable display at a position elevated above the surface-touching bottom of the display without distorting the shape of the inflatable display and without the need for a base to support and elevate the fan above the ground to achieve sufficient air intake. Electric fan 13 can be easily removed from its housing 15 for cleaning or replacement whenever necessary. Electric fan 13 is covered with safety grill 16 to guard against unwanted debris from entering the display as well as contacting fan blades 30. Around the edge of standard-sized fabric 29 is male fastening device 20 for attaching interchangeable fan assembly 12 through a receiving opening to female fastening device 24 of inflatable display 10. Male fastening device 20 for attaching interchangeable fan assembly 12 to female fastening device 24 is illustrated in the preferred embodiment to comprise a zipper system, but other means of attachment such as fasteners, buttons, hook and loop fastening tape, or the like can be used. Referring now to FIG. 5, secured to inflatable display 10a is interchangeable fan assembly 12. User detaches interchangeable fan assembly 12 from female fastening device 24a, and then detaches electrical connector 18 from electrical connector 23a. Interchangeable fan assembly 12 can now be removed for insertion and use with another inflatable display 10b (or 10c) by attaching electrical connector 18 to electrical connector 23b (or 23c) and then securing interchangeable fan assembly 12 through a receiving opening to inflatable display 10b (or 10c) by joining male fastening device 20 to female fastening device 24b (or 24c). Interchangeable fan assembly 12 is secured to a standard-sized piece of permeable fabric fitted for attachment to either female fastening device 24b or 24c on inflatable display 10b or 10c, respectively. Although illustrative preferred embodiments have been described herein in detail, it should be noted and will be appreciated by those skilled in the art that numerous variations may be made within the scope of this invention without departing from the principle of this invention and without sacrificing its chief advantages. The terms and expressions have been used as terms of description and not terms of limitation. There is no intention to use the terms or expressions to exclude any equivalents of features shown and described or portions thereof and this invention should be defined in accordance with the claims which follow. | <SOH> BACKGROUND OF THE INVENTION <EOH>Inflatable displays have become increasingly popular in recent years. These types of displays have a wide range of application, shape and size, including, but not limited to, figures for holiday and seasonal decoration, marketing, advertising, entertainment, and event attraction. The inflatable displays are made from a permeable fabric that allows air to pass through the fabric at approximately the same rate as the air being blown into the inflatable display. The process of continuously blowing air being supplied from the fan occurring at substantially the same rate as air escaping the fabric allows the display to maintain its three-dimensional shape without the use of an internal or external frame or structure. These are known in the industry as “cold-air” inflatable displays. Because most of these displays require a significant amount of airflow from the fan to maintain their inflated state, the fan assembly has been rather large and heavy and has been positioned at the bottom of the inflatable display adjacent the ground for support. A typical fan utilized in prior cold-air inflatable displays has a motor winding with sleeves and bearings configuration. Prior cold-air inflatable displays house the fan within a base positioned at the bottom of the figure into which the fan circulates blown air. Since the base housing the fan rests adjacent the ground, certain measures must be taken by the operator in order to ensure sufficient airflow into the fan. Specifically, the base housing the fan must be positioned at a height far enough above the ground to allow sufficient air to enter the fan. Permanently affixed legs or removable legs secured to the base have been utilized to raise the base housing the fan at a sufficient level above the ground enabling a proper airflow into the fan. If the fan is disposed too close to the ground, the flow of air into the fan may be limited and the figure may not be inflated in the manner desired. Thus, unacceptable inflation of the figure may result because the fan is positioned too low to the ground, or because the legs of the base sink further into the ground after it has already been positioned, or because unwanted debris accumulate between the fan and the ground. The fan assemblies in prior inflatable displays also have been configured such that the fan assembly and/or the base which houses the fan are permanently affixed to the fabric of the inflatable figure in a variety of ways. For example, the fabric may be directly attached to the fan housing or base or secured to the fan housing or base via a fastening member. Further, because not all inflatable displays have the same shape on their bottom surfaces, the fan and base housing assemblies are unique for each type of display. Thus, in prior inflatable devices the fan assembly is a permanent component of each display. For example, if a consumer were to purchase a jack-o-lantern inflatable display for the Halloween season, a snowman inflatable display for the holiday season, and an Uncle Sam inflatable display for Independence Day, the consumer would be purchasing three complete packages of each inflatable figure, fan assembly, and other components. As the fan assembly is a significant cost component of inflatable devices, the lack of interchangeability between fan assemblies for different displays significantly increases the cost to purchasers of multiple inflatable devices. There is no present apparatus or method utilizing a fan assembly that is interchangeable with several different inflatable figure displays. | <SOH> SUMMARY OF THE INVENTION <EOH>In the present invention, a cold-air inflatable display maintains its inflated state from one or more lightweight continuously blowing electric fan(s) positioned on the display in such a manner as to permit optimum airflow through the fan and into the display. The fan assembly is advantageously positioned on a lower portion of the display above the surface-touching bottom of the display so that the fan is elevated above the ground avoiding the problem of insufficient airflow into the display. This ensures that the airflow to the fan will not be limited preventing the fan from inflating the display with sufficient air pressure to properly maintain its shape. The positioning of the fan on a lower portion elevated above the ground further eliminates the need for a base housing for supporting the fan and legs for elevating the fan and base housing above the ground. The invention also includes an interchangeable fan assembly that can be utilized with multiple displays, thus reducing cost to purchasers and increasing their ability to enjoy the benefits of numerous inflatable displays. By affixing the fan assembly to a standard-sized piece of fabric that is detachable from one display and reattachable to another display by joining the male fastening device of the standard-sized piece of fabric with the female fastening device of the other display, a fan assembly can be incorporated and used with any given number of comparable displays. Since the fan assembly is not positioned on the surface-touching bottom of the display, there is no difficulty finding a specified location on the lower portion of each display that allows for a convenient location for the fan assembly ensuring optimum airflow into the display. It will be appreciated by those skilled in the art that the foregoing brief description and the following detailed description are exemplary and explanatory of this invention, but are not intended to be restrictive thereof or limiting of the advantages which can be achieved by this invention. Thus, the accompanying drawings, referred to herein and constituting a part hereof, illustrate preferred embodiments of this invention, and, together with the detailed description, serve to explain the principles of this invention. | 20040227 | 20071204 | 20050901 | 59588.0 | 1 | SILBERMANN, JOANNE | INTERCHANGEABLE FAN ASSEMBLY FOR COLD-AIR INFLATABLE DISPLAYS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,789,797 | ACCEPTED | Surgical access system and related methods | A surgical access system including a tissue distraction assembly and a tissue retraction assembly, both of which may be equipped with one or more electrodes for use in detecting the existence of (and optionally the distance and/or direction to) neural structures before, during, and after the establishment of an operative corridor to a surgical target site. | 1. A system for accessing a surgical target site, comprising: a handle assembly including a first arm member, a second arm member hingedly attached to said first arm member, and a translating member adapted to move longitudinally relative said first and second arm members; a first retractor blade rigidly coupled to said first arm member prior to introduction into said surgical target site, a second retractor blade rigidly coupled to said second arm member prior to introduction into said surgical target site, and a third retractor blade rigidly coupled to said translating member prior to introduction into said surgical target site; said handle being configured to simultaneously introduce said first, second and third retractor blades to said surgical target site in a closed position and thereafter opened by manually squeezing said first and second arm members relative to one another to create an operative corridor to said surgical target site. 2. The system of claim 1, further comprising a a K-wire configured to be initially advanced to said surgical target site, at least one generally cylindrical dilator configured to be slideably passed over said K-wire and secondarily advanced to said surgical target site, said at least one generally cylindrical dilator having an outer diameter slightly smaller than an inner diameter of said first, second and third retractor blades while in said closed position. 3. The system of claim 1 and further, comprising at least one shim element capable of being detachably engaged with at least one of said first, second and third retractor blades, said shim element having an extension of sufficient length to extend past a distal end of said at least one of said first, second and third retractor blades into a spinal disc space and of sufficient height to distract vertebral bodies adjacent to said spinal disc space. 4. The system of claim 1 and further, comprising at least one retractor extender capable of being detachably engaged with at least one of said first, second and third retractor blades, said retractor extender having a width wider than said at least one of said first, second and third retractor blade to prevent the ingress of adjacent tissue into said operative corridor after said first, second and third retractor blades have been opened. 5. The system of claim 2, wherein at least one of said K-wire, said at least one dilator, and at least one of said first, second and third retractor blades are equipped with at least one stimulation electrode. 6. The system of claim 5, further comprising a control unit capable of electrically stimulating said at least one stimulation electrode, sensing a response of a nerve depolarized by said stimulation, determining at least one of proximity and direction between said at least one stimulation electrode and said depolarized nerve based upon the sensed response, and communicating said at least one of proximity and direction to a user. 7. The system of claim 6, further comprising an electrode configured to sense a neuromuscular response of a muscle coupled to said depolarized nerve, the electrode being operable to send the response to the control unit. 8. The system of claim 2, wherein said K-wire has a first stimulation electrode at a distal tip of the K-wire. 9. The system of claim 1, wherein said system for establishing an operative corridor to a surgical target site is configured to access a spinal target site. 10. The system of claim 1, wherein said system is configured to establish said operative corridor via a lateral, trans-psoas approach. 11. The system of claim 6, further comprising at least one button for initiating the electrical stimulation from said control unit to said at least one stimulation electrode. 12. The system of claim 6, wherein the control unit comprises a display operable to display at least one of an electromyographic (EMG) response of said muscle coupled to said depolarized nerve and a stimulation threshold of said depolarized nerve. 13. The system of claim 6, wherein the control unit comprises a touch-screen display operable to receive commands from a user. 14. The system of claim 6, wherein said stimulation electrodes are positioned near a distal end of at least one of said K-wire, said at least one generally cylindrical dilator, and said at least one of said first, second and third retractor blades. 15. A method of accessing a surgical target site, comprising the steps of: advancing at least one generally cylindrical dilator to said surgical target site; thereafter advancing over said at least one dilator a retractor assembly including a first retractor blade, a second retractor blade and a third retractor blade releasably coupled to a hinged handle assembly while said first, second and third retractor blades are positioned generally adjacent to one another in a closed position; and thereafter manually squeezing said hinged handle assembly to move said first, second and third retractor blades into an open position to create an operative corridor to said surgical target site. 16. The method of claim 15, wherein said step of advancing at least one dilator is preceded by advancing a K-wire to said surgical target site and thereafter slidably passing said at least dilator over said K-wire. 17. The method of claim 15, including the step of detachably engaging at least one shim element having an extension to at least one of said first second and third retractor blades after said first, second and third retractor blades have been advanced to said surgical target site and thereafter advancing said shim element such that said extension extends past a distal end of said at least one of said first, second and third retractor blades into a spinal disc space and distracts vertebral bodies adjacent to said spinal disc space. 18. The method of claim 17, wherein said at least one shim element is detachably coupled to said third retractor blade, which is disposed near the posterior region of the spine. 19. The method of claim 15, further comprising the step of performing neuromonitoring during at least one of the steps of advancing said at least one dilator, advancing said retractor assembly over said at least one dilator, and after said retractor assembly has been manually opened by squeezing said hinged handle assembly. | CROSS-REFERENCES TO RELATED APPLICATIONS The present application is an International Patent Application of and claims the benefit of priority from commonly owned and co-pending U.S. Provisional Patent Application Ser. Nos. 60/450,806 (filed Feb. 27, 2003), the entire contents of which is hereby expressly incorporated by reference into this disclosure as if set forth fully herein. BACKGROUND OF THE INVENTION I. Field of the Invention The present invention relates generally to systems and methods for performing surgical procedures and, more particularly, for accessing a surgical target site in order to perform surgical procedures. II. Discussion of the Prior Art A noteworthy trend in the medical community is the move away from performing surgery via traditional “open” techniques in favor of minimally invasive or minimal access techniques. Open surgical techniques are generally undesirable in that they typically require large incisions and high amounts of tissue displacement to gain access to the surgical target site, which produces concomitantly high amounts of pain, lengthened hospitalization (increasing health care costs), and high morbidity in the patient population. Less-invasive surgical techniques (including so-called “minimal access” and “minimally invasive” techniques) are gaining favor due to the fact that they involve accessing the surgical target site via incisions of substantially smaller size with greatly reduced tissue displacement requirements. This, in turn, reduces the pain, morbidity and cost associated with such procedures. The access systems developed to date, however, fail in various respects to meet all the needs of the surgeon population. One drawback associated with prior art surgical access systems relates to the ease with which the operative corridor can be created, as well as maintained over time, depending upon the particular surgical target site. For example, when accessing surgical target sites located beneath or behind musculature or other relatively strong tissue (such as, by way of example only, the psoas muscle adjacent to the spine), it has been found that advancing an operative corridor-establishing instrument directly through such tissues can be challenging and/or lead to unwanted or undesirable effects (such as stressing or tearing the tissues). While certain efforts have been undertaken to reduce the trauma to tissue while creating an operative corridor, such as (by way of example only) the sequential dilation system of U.S. Pat. No. 5,792,044 to Foley et al., these attempts are nonetheless limited in their applicability based on the relatively narrow operative corridor. More specifically, based on the generally cylindrical nature of the so-called “working cannula,” the degree to which instruments can be manipulated and/or angled within the cannula can be generally limited or restrictive, particularly if the surgical target site is a relatively deep within the patient. Efforts have been undertaken to overcome this drawback, such as shown in U.S. Pat. No. 6,524,320 to DiPoto, wherein an expandable portion is provided at the distal end of a cannula for creating a region of increased cross-sectional area adjacent to the surgical target site. While this system may provide for improved instrument manipulation relative to sequential dilation access systems (at least at deep sites within the patient), it is nonetheless flawed in that the deployment of the expandable portion may inadvertently compress or impinge upon sensitive tissues adjacent to the surgical target site. For example, in anatomical regions having neural and/or vasculature structures, such a blind expansion may cause the expandable portion to impinge upon these sensitive tissues and cause neural and/or vasculature compromise, damage and/or pain for the patient. This highlights yet another drawback with the prior art surgical access systems, namely, the challenges in establishing an operative corridor through or near tissue having major neural structures which, if contacted or impinged, may result in neural impairment for the patient. Due to the threat of contacting such neural structures, efforts thus far have largely restricted to establishing operative corridors through tissue having little or substantially reduced neural structures, which effectively limits the number of ways a given surgical target site can be accessed. This can be seen, by way of example only, in the spinal arts, where the exiting nerve roots and neural plexus structures in the psoas muscle have rendered a lateral or far lateral access path (so-called trans-psoas approach) to the lumbar spine virtually impossible. Instead, spine surgeons are largely restricted to accessing the spine from the posterior (to perform, among other procedures, posterior lumbar interbody fusion (PLIF)) or from the anterior (to perform, among other procedures, anterior lumbar interbody fusion (ALIF)). Posterior-access procedures involve traversing a shorter distance within the patient to establish the operative corridor, albeit at the price of oftentimes having to reduce or cut away part of the posterior bony structures (i.e. lamina, facets, spinous process) in order to reach the target site (which typically comprises the disc space). Anterior-access procedures are relatively simple for surgeons in that they do not involve reducing or cutting away bony structures to reach the surgical target site. However, they are nonetheless disadvantageous in that they require traversing through a much greater distance within the patient to establish the operative corridor, oftentimes requiring an additional surgeon to assist with moving the various internal organs out of the way to create the operative corridor. The present invention is directed at eliminating, or at least minimizing the effects of, the above-identified drawbacks in the prior art. SUMMARY OF THE INVENTION The present invention accomplishes this goal by providing a novel access system and related methods which involve detecting the existence of (and optionally the distance and/or direction to) neural structures before, during, and after the establishment of an operative corridor through (or near) any of a variety of tissues having such neural structures which, if contacted or impinged, may otherwise result in neural impairment for the patient. It is expressly noted that, although described herein largely in terms of use in spinal surgery, the access system of the present invention is suitable for use in any number of additional surgical procedures wherein tissue having significant neural structures must be passed through (or near) in order to establish an operative corridor. According to one broad aspect of the present invention, the access system comprises a tissue distraction assembly and a tissue retraction assembly, both of which may be equipped with one or more electrodes for use in detecting the existence of (and optionally the distance and/or direction to) neural structures. The tissue distraction assembly (in conjunction with one or more elements of the tissue retraction assembly) is capable of, as an initial step, distracting a region of tissue between the skin of the patient and the surgical target site. The tissue retraction assembly is capable of, as a secondary step, being introduced into this distracted region to thereby define and establish the operative corridor. Once established, any of a variety of surgical instruments, devices, or implants may be passed through and/or manipulated within the operative corridor depending upon the given surgical procedure. The electrode(s) are capable of, during both tissue distraction and retraction, detecting the existence of (and optionally the distance and/or direction to) neural structures such that the operative corridor may be established through (or near) any of a variety of tissues having such neural structures which, if contacted or impinged, may otherwise result in neural impairment for the patient. In this fashion, the access system of the present invention may be used to traverse tissue that would ordinarily be deemed unsafe or undesirable, thereby broadening the number of manners in which a given surgical target site may be accessed. The tissue distraction assembly may include any number of components capable of performing the necessary distraction. By way of example only, the tissue distraction assembly may include a K-wire, an initial dilator of split construction, and one or more dilators of traditional (that is, non-split) construction for performing the necessary tissue distraction to receive the remainder of the tissue retractor assembly thereafter. One or more electrodes may be provided on one or more of the K-wire and dilator(s) to detect the presence of (and optionally the distance and/or direction to) neural structures during tissue distraction. The tissue retraction assembly may include any number of components capable of performing the necessary retraction. By way of example only, the tissue retraction assembly may include one or more retractor blades extending from a handle assembly. The handle assembly may be manipulated to open the retractor assembly; that is, allowing the retractor blades to separate from one another simultaneously to create an operative corridor to the surgical target site. In a preferred embodiment, this is accomplished by maintaining a posterior retractor blade in a fixed position relative to the surgical target site (so as to avoid having it impinge upon any exiting nerve roots near the posterior elements of the spine) while the additional retractor blades (i.e. cephalad-most and caudal-most blades) are moved or otherwise translated away from the posterior retractor blade (and each other) so as to create the operative corridor in a fashion that doesn't infringe upon the region of the exiting nerve roots. The retractor blades may be optionally dimensioned to receive and direct a rigid shim element to augment the structural stability of the retractor blades and thereby ensure the operative corridor, once established, will not decrease or become more restricted, such as may result if distal ends of the retractor blades were permitted to “slide” or otherwise move in response to the force exerted by the displaced tissue. In a preferred embodiment, only the posterior retractor blade is equipped with such a rigid shim element. In an optional aspect, this shim element may be advanced into the disc space after the posterior retractor blade is positioned, but before the retractor is opened into the fully retracted position. The rigid shim element is preferably oriented within the disc space such that is distracts the adjacent vertebral bodies, which serves to restore disc height. It also preferably advances a sufficient distance within the disc space (preferably past the midline), which serves the dual purpose of preventing post-operative scoliosis and forming a protective barrier (preventing the migration of tissue (such as nerve roots) into the operative field and the inadvertent advancement of instruments outside the operative field). The retractor blades may optionally be equipped with a mechanism for transporting or emitting light at or near the surgical target site to aid the surgeon's ability to visualize the surgical target site, instruments and/or implants during the given surgical procedure. According to one embodiment, this mechanism may comprise, but need not be limited to, providing one or more strands of fiber optic cable within the walls of the retractor blades such that the terminal (distal) ends are capable of emitting light at or near the surgical target site. According to another embodiment, this mechanism may comprise, but need not be limited to, constructing the retractor blades of suitable material (such as clear polycarbonate) and configuration such that light may be transmitted generally distally through the walls of the retractor blade light to shine light at or near the surgical target site. This may be performed by providing the retractor blades having light-transmission characteristics (such as with clear polycarbonate construction) and transmitting the light almost entirely within the walls of the retractor blade (such as by frosting or otherwise rendering opaque portions of the exterior and/or interior) until it exits a portion along the interior (or medially-facing) surface of the retractor blade to shine at or near the surgical target site. The exit portion may be optimally configured such that the light is directed towards the approximate center of the surgical target site and may be provided along the entire inner periphery of the retractor blade or one or more portions therealong. BRIEF DESCRIPTION OF THE DRAWINGS Many advantages of the present invention will be apparent to those skilled in the art with a reading of this specification in conjunction with the attached drawings, wherein like reference numerals are applied to like elements and wherein: FIG. 1 is a perspective view of a tissue retraction assembly (in use) forming part of a surgical access system according to the present invention; FIG. 2 is a perspective view illustrating the components and use of an initial distraction assembly (i.e. K-wire, an initial dilating cannula with handle, and a split-dilator housed within the initial dilating cannula) forming part of the surgical access system according to the present invention, for use in distracting to a surgical target site (i.e. annulus); FIG. 3 is a perspective view illustrating the K-wire and split-dilator of the initial distraction assembly with the initial dilating cannula and handle removed; FIG. 4 is a posterior view of the vertebral target site illustrating the split-dilator of the present invention in use distracting in a generally cephalad-caudal fashion according to one aspect of the present invention; FIG. 5 is a side view illustrating the use of a secondary distraction assembly (comprising a plurality of dilating cannulae over the K-wire) to further distract tissue between the skin of the patient and the surgical target site according to the present invention; FIGS. 6-7 are perspective and side views, respectively, of a retractor assembly according to the present invention, comprising a handle assembly having three (3) retractor blades extending there from (posterior, cephalad-most, and caudal-most) disposed over the secondary distraction assembly of FIG. 5 (shown in a first, closed position); FIGS. 8-10 are perspective, side and top views, respectively, of the retractor assembly of FIGS. 6-7 in a second, opened (i.e. retracted) position (over the secondary distraction assembly) to thereby create an operative corridor to a surgical target site according to the present invention; FIGS. 11-13 are perspective, side and top views, respectively, of the retractor assembly of FIGS. 6-7 in the second, opened (i.e. retracted) position (with the secondary distraction assembly removed) illustrating the operative corridor to the surgical target site according to the present invention; FIG. 14 is an enlarged perspective view of the interior surface of a retractor blade, illustrating a pair of dove-tail grooves dimensioned to engage a shim element (as shown in FIG. 15) and/or a retractor extender (as shown in FIG. 16) according to the present invention; FIG. 15 is a perspective view of a shim element dimensioned to be adjustably and removably coupled to a retractor blade (as shown in FIG. 14) according to the present invention; FIG. 16 is a perspective view of a retractor extender dimensioned to be adjustably and removably coupled to a retractor blade (as shown in FIG. 14) according to the present invention; FIGS. 17-18 are perspective and side views, respectively, of the retractor assembly illustrating the use of an introducer device for coupling the shim element of FIG. 15 to the posterior retractor blade and introducing the distal end of the shim (shim extension) into the intradiscal space according to the present invention; FIGS. 19-21 are perspective, side and top views, respectively, of the retractor assembly illustrating the shim element after introduction according to the present invention; FIG. 22 is a side view of the retractor assembly illustrating the shim element and one of two retractor extenders after introduction according to the present invention; FIG. 23 is a perspective view of an exemplary nerve monitoring system capable of performing nerve monitoring before, during and after the creating of an operative corridor to a surgical target site using the surgical access system in accordance with the present invention; FIG. 24 is a block diagram of the nerve monitoring system shown in FIG. 23; and FIGS. 25-26 are screen displays illustrating exemplary features and information communicated to a user during the use of the nerve monitoring system of FIG. 23. DESCRIPTION OF THE PREFERRED EMBODIMENT Illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. It is furthermore to be readily understood that, although discussed below primarily within the context of spinal surgery, the surgical access system of the present invention may be employed in any number of anatomical settings to provide access to any number of different surgical target sites throughout the body. The surgical access system disclosed herein boasts a variety of inventive features and components that warrant patent protection, both individually and in combination. The present invention involves accessing a surgical target site in a fashion less invasive than traditional “open” surgeries and doing so in a manner that provides access in spite of the neural structures required to be passed through (or near) in order to establish an operative corridor to the surgical target site. Generally speaking, the surgical access system of the present invention accomplishes this by providing a tissue distraction assembly and a tissue retraction assembly, both of which may be equipped with one or more electrodes for use in detecting the existence of (and optionally the distance and/or direction to) neural structures. These electrodes are preferably provided for use with a nerve surveillance system such as, by way of example, the type shown and described in co-pending and commonly assigned Int'l Patent Application Ser. No. filed Sep. 25, 2002 (claiming priority to U.S. Provisional App. Ser. No. 60/325,424 filed on Sep. 25, 2001), the entire contents of which are expressly incorporated by reference as if set forth herein in their entirety (“the '424 PCT”). Generally speaking, this nerve surveillance system is capable of detecting the existence of (and optionally the distance and/or direction to) neural structures during the distraction and retraction of tissue by detecting the presence of nerves by applying a stimulation signal to such instruments and monitoring the evoked EMG signals from the myotomes associated with the nerves being passed by the distraction and retraction systems of the present invention. In so doing, the system as a whole (including the surgical access system of the present invention) may be used to form an operative corridor through (or near) any of a variety of tissues having such neural structures, particularly those which, if contacted or impinged, may otherwise result in neural impairment for the patient. In this fashion, the access system of the present invention may be used to traverse tissue that would ordinarily be deemed unsafe or undesirable, thereby broadening the number of manners in which a given surgical target site may be accessed. The tissue distraction assembly of the present invention (comprising a K-wire, an initial dilator, and a split-dilator disposed within the initial dilator) is employed to distract the tissues extending between the skin of the patient and a given surgical target site (preferably along the posterior region of the target intervertebral disc). A secondary distraction assembly (i.e. a plurality of sequentially dilating cannulae) may optionally be employed after the initial distraction assembly to further distract the tissue. Once distracted, the resulting void or distracted region within the patient is of sufficient size to accommodate a tissue retraction assembly of the present invention. More specifically, the tissue retraction assembly (comprising a plurality of retractor blades extending from a handle assembly) may be advanced relative to the secondary distraction assembly such that the retractor blades, in a first, closed position, are advanced over the exterior of the secondary distraction assembly. At that point, the handle assembly may be operated to move the retractor blades into a second, open or “retracted” position to create an operative corridor to the surgical target site. According to one aspect of the invention, following (or before) this retraction, a posterior shim element (which is preferably slideably engaged with the posterior retractor blade) may be advanced such that a distal shim extension in positioned within the posterior region of the disc space. If done before retraction, this helps ensure that the posterior retractor blade will not move posteriorly during the retraction process, even though the other retractor blades (i.e. cephalad-most and caudal-most) are able to move and thereby create an operative corridor. Fixing the posterior retractor blade in this fashion serves several important functions. First, the distal end of the shim element serves to distract the adjacent vertebral bodies, thereby restoring disc height. It also rigidly couples the posterior retractor blade in fixed relation relative to the vertebral bodies. The posterior shim element also helps ensure that surgical instruments employed within the operative corridor are incapable of being advanced outside the operative corridor, preventing inadvertent contact with the exiting nerve roots during the surgery. Once in the appropriate retracted state, the cephalad-most and caudal-most retractor blades may be locked in position and, thereafter, retractor extenders advanced therealong to prevent the ingress or egress of instruments or biological structures (i.e. nerves, vasculature, etc. . . . ) into or out of the operative corridor. Once the operative corridor is established, any of a variety of surgical instruments, devices, or implants may be passed through and/or manipulated within the operative corridor depending upon the given surgical procedure. FIG. 1 illustrates a tissue retraction assembly 10 forming part of a surgical access system according to the present invention. The retraction assembly 10 includes a plurality of retractor blades extending from a handle assembly 20. By way of example only, the handle assembly 20 is provided with a posterior retractor blade 12, a cephalad-most retractor blade 16, and a caudal-most retractor blade 18. Although shown and described below with regard to the three-bladed configuration, it is to be readily appreciated that the number of retractor blades may be increased or decreased without departing from the scope of the present invention. The retractor assembly 10 is shown in a fully retracted or “open” configuration, with the retractor blades 12, 16, 18 positioned a distance from one another so as to form an operative corridor 15 there between and extending to a surgical target site (i.e. an annulus of an intervertebral disc). The retractor blades 12, 16, 18 may be equipped with various additional features or components. By way of example only, posterior retractor blade 12 may be equipped with a shim element 22 (shown more clearly in FIG. 15). Shim element 22 serves to distract the adjacent vertebral bodies (thereby restoring disc height), helps secure the retractor assembly 10 relative to the surgical target site, and forms a protective barrier to prevent the ingress or egress of instruments or biological structures (i.e. nerves, vasculature, etc. . . . ) into or out of the operative corridor. Each of the remaining retractor blades (cephalad-most blade 16 and caudal-most blade 18) may be equipped with a retractor extender 24 (shown more clearly in FIG. 16). The retractor extenders 24 extend from the cephalad-most and caudal-most retractor blades 16, 18 to form a protective barrier to prevent the ingress or egress of instruments or biological structures (i.e. nerves, vasculature, etc. . . . ) into or out of the operative corridor. According to the present invention, any or all of the retractor blades 12, 16, 18, the shim element 22 and/or the retractor extender 24 may be provided with one or more electrodes 39 (preferably at their distal regions) equipped for use with a nerve surveillance system, such as, by way of example, the type shown and described in the NeuroVision PCT Applications set forth below. The handle assembly 20 may be coupled to any number of mechanisms for rigidly registering the handle assembly 20 in fixed relation to the operative site, such as through the use of an articulating arm mounted to the operating table. The handle assembly 20 includes first and second arm members 26, 28 hingedly coupled via coupling mechanism 30 (i.e. bolt/nut combination disposed through receiving apertures formed along arm members 26, 28). The cephalad-most retractor blade 16 is rigidly coupled (generally perpendicularly) to the end of the first arm member 26. The caudal-most retractor blade 18 is rigidly coupled (generally perpendicularly) to the end of the second arm member 28. With combined reference to FIG. 10, the posterior retractor blade 12 is rigidly coupled (generally perpendicularly to) a translating member 17, which is coupled to the handle assembly 20 via a linkage assembly 14. The linkage assembly 14 includes a first link 34 hingedly disposed between the translating member 17 and a point along the first arm member 26 of the handle assembly 20, and a second link 36 hingedly disposed between the translating member 17 and the second arm member 28 of the handle assembly 20. The translating member 17 includes a translation slot 19 through the bolt/nut combination of the coupling mechanism 30 may engage. In use, a user can squeeze the proximal ends of the arms 26, 28 and thereby cause the coupling mechanism 30 to translate distally within the slot 19, which increases the relative distance between the posterior retractor blade 12 and the cephalad-most and caudal-most retractor blades 16, 18. This squeezing motion of the arms 26, 28 simultaneously causes the cephalad-most and caudal-most retractor blades 16, 18 to move away from one another. Taken collectively, the diameter of the operative corridor 15 increases at approximately the same time. An optional locking mechanism 35 (i.e. bolt and nut combination extending between arm members 26, 28) may be provided to selectively lock the arm members 26, 28 relative to one another to thus maintain the retractor assembly 10 in the fully retracted position, once achieved. FIG. 2 illustrates an initial distraction assembly 40 forming part of the surgical access system according to the present invention. The initial distraction assembly 40 includes a K-wire 42, an initial dilating cannula 44 with handle 46, and a split-dilator 48 housed within the initial dilating cannula 44. In use, the K-wire 42 and split-dilator 48 are disposed within the initial dilating cannula 44 and the entire assembly 40 advanced through the tissue towards the surgical target site (i.e. annulus). Again, this is preferably accomplished while employing the nerve detection and/or direction features described above. After the initial dilating assembly 40 is advanced such that the distal ends of the split-dilator 48 and initial dilator 44 are positioned within the disc space (FIG. 2), the initial dilator 44 and handle 46 are removed (FIG. 3) to thereby leave the split-dilator 48 and K-wire 42 in place. As shown in FIG. 4, the split-dilator 48 is thereafter split such that the respective halves 48a, 48b are separated from one another to distract tissue in a generally cephalad-caudal fashion relative to the target site. The split dilator 48 may thereafter be relaxed (allowing the dilator halves 48a, 48b to come together) and rotated such that the dilator halves 48a, 48b are disposed in the anterior-posterior plane. Once rotated in this manner, the dilator halves 48a, 48b are again separated to distract tissue in a generally anterior-posterior fashion. Each dilator halve 48a, 48b may be, according to the present invention, provided with one or more electrodes (preferably at their distal regions) equipped for use with a nerve surveillance system, such as, by way of example, the type shown and described in the NeuroVision PCT Applications set forth below. Following this initial distraction, a secondary distraction may be optionally undertaken, such as via a sequential dilation system 50 as shown in FIG. 5. According to the present invention, the sequential dilation system 50 may include the K-wire 42, the initial dilator 44, and one or more supplemental dilators 52, 54 for the purpose of further dilating the tissue down to the surgical target site. Once again, each component of the secondary distraction assembly 50 (namely, the K-wire 42, the initial dilator 44, and the supplemental dilators 52, 54 may be, according to the present invention, provided with one or more electrodes (preferably at their distal regions) equipped for use with a nerve surveillance system, such as, by way of example, the type shown and described in the NeuroVision PCT Applications set forth below. As shown in FIGS. 6-7, the retraction assembly 10 of the present invention is thereafter advanced along the exterior of the sequential dilation system 50. This is accomplished by maintaining the retractor blades 12, 16, 18 in a first, closed position (with the retractor blades 12-16 in generally abutting relation to one another). Once advanced to the surgical target site, the handle assembly 20 may be operated as shown in FIGS. 8-10 to move the retractor blades 12, 16, 18 into a second, open or “retracted” position. As one can see, the posterior retractor blade 12 is allowed to stay in the same general position during this process, such that the cephalad-most and caudal-most retractor blades 14, 16 move away from the posterior retractor blade 12. Again, this is accomplished through the cooperation between the translation member 17 (attached to the posterior retractor blade 12) and the arms 26, 28 of the handle assembly 20 via the linkage assembly 14 and slot 19 in conjunction with the coupling mechanism 30. FIGS. 11-13 illustrate the retractor assembly 10 in the second, opened (i.e. retracted) position (with the secondary distraction assembly 50 removed for clarity) illustrating the operative corridor 15 to the surgical target site according to the present invention. FIGS. 14-16 illustrate an important aspect of the present invention, wherein (FIG. 15) each retractor blade 12, 16, 18 is provided with a pair of engagement grooves 37 having, by way of example only, a generally dove-tailed cross-sectional shape. The engagement grooves 37 are dimensioned to engage with dove-tail elements 41 provided on the shim element 22 (FIG. 15) and each retractor extender 24 (FIG. 16). In a preferred embodiment, the shim element 22 and retractor extender 24 are each provided with an elongate slot 43 and tool-engaging elements 45. A tool may be used to bias the arms 47 of each device inwardly towards one another (decreasing the width of part or most of the slot 43), which forces the dove-tail elements 41 towards one another. This is shown, by way of example only, in FIGS. 17-18, wherein a tool 59 is used to introduce the shim element 22 into engaged relation with the posterior retractor blade 12. When the shim element 22 has been introduced to a desired position (such as having the distal end extend into the intradiscal space as best shown in FIGS. 18 and 20), the tool 59 may then be disengaged or released from the tool-engaging elements 45 such that the dove-tail elements 41 return to their normal position (being biased outwardly by the resiliency of the arms 47) to thereby secure the shim element 22 relative to the posterior retractor blade 12. FIGS. 19-21 illustrate the shim element 22 after introduction according to the present invention. The same process can be used with the retractor extender 24 shown in FIG. 16 with respect to the cephalad-most and caudal-most retractor blades 16, 18. The end result is shown in FIG. 22 with the retraction assembly 10 of the present invention disposed in position over a surgical target site. Nerve Surveillance According to yet another aspect of the present invention, any number of distraction components and/or retraction components (including but not limited to those described herein) may be equipped to detect the presence of (and optionally the distance and/or direction to) neural structures during the steps tissue distraction and/or retraction. This is accomplished by employing the following steps: (1) one or more stimulation electrodes are provided on the various distraction and/or retraction components; (2) a stimulation source (e.g. voltage or current) is coupled to the stimulation electrodes; (3) a stimulation signal is emitted from the stimulation electrodes as the various components are advanced towards or maintained at or near the surgical target site; and (4) the patient is monitored to determine if the stimulation signal causes muscles associated with nerves or neural structures within the tissue to innervate. If the nerves innervate, this may indicate that neural structures may be in close proximity to the distraction and/or retraction components. Neural monitoring may be accomplished via any number of suitable fashions, including but not limited to observing visual twitches in muscle groups associated with the neural structures likely to found in the tissue, as well as any number of monitoring systems, including but not limited to any commercially available “traditional” electromyography (EMG) system (that is, typically operated by a neurophysiologist. Such monitoring may also be carried out via the surgeon-driven EMG monitoring system shown and described in the following commonly owned and co-pending PCT Applications (collectively “NeuroVision PCT Applications”): PCT App. Ser. No. PCT/US02/22247, entitled “System and Methods for Determining Nerve Proximity, Direction, and Pathology During Surgery,” filed on Jul. 11, 2002; PCT App. Ser. No. PCT/US02/30617, entitled “System and Methods for Performing Surgical Procedures and Assessments,” filed on Sep. 25, 2002; PCT App. Ser. No. PCT/US02/35047, entitled “System and Methods for Performing Percutaneous Pedicle Integrity Assessments,” filed on Oct. 30, 2002; and PCT App. Ser. No. PCT/US03/02056, entitled “System and Methods for Determining Nerve Direction to a Surgical Instrument,” filed Jan. 15, 2003. The entire contents of each of the above-enumerated NeuroVision PCT Applications is hereby expressly incorporated by reference into this disclosure as if set forth fully herein. In any case (visual monitoring, traditional EMG and/or surgeon-driven EMG monitoring), the access system of the present invention may advantageously be used to traverse tissue that would ordinarily be deemed unsafe or undesirable, thereby broadening the number of manners in which a given surgical target site may be accessed. FIGS. 23-24 illustrate, by way of example only, a monitoring system 120 of the type disclosed in the NeuroVision PCT Applications suitable for use with the surgical access system 10 of the present invention. The monitoring system 120 includes a control unit 122, a patient module 124, and an EMG harness 126 and return electrode 128 coupled to the patient module 124, and a cable 132 for establishing electrical communication between the patient module 124 and the surgical access system 10 (FIG. 1). More specifically, this electrical communication can be achieved by providing, by way of example only, a hand-held stimulation controller 152 capable of selectively providing a stimulation signal (due to the operation of manually operated buttons on the hand-held stimulation controller 152) to one or more connectors 156a, 156b, 156c. The connectors 156a, 156b, 156c are suitable to establish electrical communication between the hand-held stimulation controller 152 and (by way of example only) the stimulation electrodes on the K-wire 42, the dilators 44, 52, 54, the retractor blades 12, 16, 18 and/or the shim elements 22, 24 (collectively “surgical access instruments”). In order to use the monitoring system 120, then, these surgical access instruments must be connected to the connectors 156a, 156b and/or 156c, at which point the user may selectively initiate a stimulation signal (preferably, a current signal) from the control unit 122 to a particular surgical access instruments. Stimulating the electrode(s) on these surgical access instruments before, during and/or after establishing operative corridor will cause nerves that come into close or relative proximity to the surgical access instruments to depolarize, producing a response in a myotome associated with the innervated nerve. The control unit 122 includes a touch screen display 140 and a base 142, which collectively contain the essential processing capabilities (software and/or hardware) for controlling the monitoring system 120. The control unit 122 may include an audio unit 118 that emits sounds according to a location of a surgical element with respect to a nerve. The patient module 124 is connected to the control unit 122 via a data cable 144, which establishes the electrical connections and communications (digital and/or analog) between the control unit 122 and patient module 124. The main functions of the control unit 122 include receiving user commands via the touch screen display 140, activating stimulation electrodes on the surgical access instruments, processing signal data according to defined algorithms, displaying received parameters and processed data, and monitoring system status and report fault conditions. The touch screen display 140 is preferably equipped with a graphical user interface (GUI) capable of communicating information to the user and receiving instructions from the user. The display 140 and/or base 142 may contain patient module interface circuitry (hardware and/or software) that commands the stimulation sources, receives digitized signals and other information from the patient module 124, processes the EMG responses to extract characteristic information for each muscle group, and displays the processed data to the operator via the display 140. In one embodiment, the monitoring system 120 is capable of determining nerve direction relative to one or more of the surgical access instruments before, during and/or following the creation of an operative corridor to a surgical target site. Monitoring system 120 accomplishes this by having the control unit 122 and patient module 124 cooperate to send electrical stimulation signals to one or more of the stimulation electrodes provided on these instruments. Depending upon the location of the surgical access system 10 within a patient (and more particularly, to any neural structures), the stimulation signals may cause nerves adjacent to or in the general proximity of the surgical access system 10 to depolarize. This causes muscle groups to innervate and generate EMG responses, which can be sensed via the EMG harness 126. The nerve direction feature of the system 120 is based on assessing the evoked response of the various muscle myotomes monitored by the system 120 via the EMG harness 126. By monitoring the myotomes associated with the nerves (via the EMG harness 126 and recording electrode 127) and assessing the resulting EMG responses (via the control unit 122), the surgical access system 10 is capable of detecting the presence of (and optionally the distant and/or direction to) such nerves. This provides the ability to actively negotiate around or past such nerves to safely and reproducibly form the operative corridor to a particular surgical target site, as well as monitor to ensure that no neural structures migrate into contact with the surgical access system 10 after the operative corridor has been established. In spinal surgery, for example, this is particularly advantageous in that the surgical access system 10 may be particularly suited for establishing an operative corridor to an intervertebral target site in a postero-lateral, trans-psoas fashion so as to avoid the bony posterior elements of the spinal column. FIGS. 25-26 are exemplary screen displays (to be shown on the display 140) illustrating one embodiment of the nerve direction feature of the monitoring system shown and described with reference to FIGS. 23-24. These screen displays are intended to communicate a variety of information to the surgeon in an easy-to-interpret fashion. This information may include, but is not necessarily limited to, a display of the function 180 (in this case “DIRECTION”), a graphical representation of a patient 181, the myotome levels being monitored 182, the nerve or group associated with a displayed myotome 183, the name of the instrument being used 184 (in this case, a dilator 46, 48), the size of the instrument being used 185, the stimulation threshold current 186, a graphical representation of the instrument being used 187 (in this case, a cross-sectional view of a dilator 46, 48) to provide a reference point from which to illustrate relative direction of the instrument to the nerve, the stimulation current being applied to the stimulation electrodes 188, instructions for the user 189 (in this case, “ADVANCE” and/or “HOLD”), and (in FIG. 15) an arrow 190 indicating the direction from the instrument to a nerve. This information may be communicated in any number of suitable fashions, including but not limited to the use of visual indicia (such as alpha-numeric characters, light-emitting elements, and/or graphics) and audio communications (such as a speaker element). Although shown with specific reference to a dilating cannula (such as at 184), it is to be readily appreciated that the present invention is deemed to include providing similar information on the display 140 during the use of any or all of the various instruments forming the surgical access system 10 of the present invention, including the distraction assemblies 40, 50, the retractor blades 12, 16, 18 and/or the shim members 22, 24. The surgical access system 10 of the present invention may be sold or distributed to end users in any number of suitable kits or packages (sterile and/or non-sterile) containing some or all of the various components described herein. As evident from the above discussion and drawings, the present invention accomplishes the goal of gaining access a surgical target site in a fashion less invasive than traditional “open” surgeries and, moreover, does so in a manner that provides the ability to access such a surgical target site regardless of the neural structures required to be passed through (or near) in order to establish an operative corridor to the surgical target site. The present invention furthermore provides the ability to perform neural monitoring in the tissue or regions adjacent the surgical target site during any procedures performed after the operative corridor has been established. The surgical access system of the present invention can be used in any of a wide variety of surgical or medical applications, above and beyond the spinal applications discussed herein. Such spinal applications may include any procedure wherein instruments, devices, implants and/or compounds are to be introduced into or adjacent the surgical target site, including but not limited to discectomy, fusion (including PLIF, ALIF, TLIF and any fusion effectuated via a lateral or far-lateral approach and involving, by way of example, the introduction of bone products (such as allograft or autograft) and/or devices having ceramic, metal and/or plastic construction (such as mesh) and/or compounds such as bone morphogenic protein), total disc replacement, etc. . . . ). Moreover, the surgical access system of the present invention opens the possibility of accessing an increased number of surgical target sites in a “less invasive” fashion by eliminating or greatly reducing the threat of contacting nerves or neural structures while establishing an operative corridor through or near tissues containing such nerves or neural structures. In so doing, the surgical access system of the present invention represents a significant advancement capable of improving patient care (via reduced pain due to “less-invasive” access and reduced or eliminated risk of neural contact before, during, and after the establishment of the operative corridor) and lowering health care costs (via reduced hospitalization based on “less-invasive” access and increased number of suitable surgical target sites based on neural monitoring). Collectively, these translate into major improvements to the overall standard of care available to the patient population, both domestically and overseas. While certain embodiments have been described, it will be appreciated by those skilled in the art that variations may be accomplished in view of these teachings without deviating from the spirit or scope of the present application. For example, with regard to the monitoring system 120, it may be implemented using any combination of computer programming software, firmware or hardware. As a preparatory act to practicing the system 120 or constructing an apparatus according to the application, the computer programming code (whether software or firmware) according to the application will typically be stored in one or more machine readable storage mediums such as fixed (hard) drives, diskettes, optical disks, magnetic tape, semiconductor memories such as ROMs, PROMs, etc., thereby making an article of manufacture in accordance with the application. The article of manufacture containing the computer programming code may be used by either executing the code directly from the storage device, by copying the code from the storage device into another storage device such as a hard disk, RAM, etc. or by transmitting the code on a network for remote execution. As can be envisioned by one of skill in the art, many different combinations of the above may be used and accordingly the present application is not limited by the scope of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>I. Field of the Invention The present invention relates generally to systems and methods for performing surgical procedures and, more particularly, for accessing a surgical target site in order to perform surgical procedures. II. Discussion of the Prior Art A noteworthy trend in the medical community is the move away from performing surgery via traditional “open” techniques in favor of minimally invasive or minimal access techniques. Open surgical techniques are generally undesirable in that they typically require large incisions and high amounts of tissue displacement to gain access to the surgical target site, which produces concomitantly high amounts of pain, lengthened hospitalization (increasing health care costs), and high morbidity in the patient population. Less-invasive surgical techniques (including so-called “minimal access” and “minimally invasive” techniques) are gaining favor due to the fact that they involve accessing the surgical target site via incisions of substantially smaller size with greatly reduced tissue displacement requirements. This, in turn, reduces the pain, morbidity and cost associated with such procedures. The access systems developed to date, however, fail in various respects to meet all the needs of the surgeon population. One drawback associated with prior art surgical access systems relates to the ease with which the operative corridor can be created, as well as maintained over time, depending upon the particular surgical target site. For example, when accessing surgical target sites located beneath or behind musculature or other relatively strong tissue (such as, by way of example only, the psoas muscle adjacent to the spine), it has been found that advancing an operative corridor-establishing instrument directly through such tissues can be challenging and/or lead to unwanted or undesirable effects (such as stressing or tearing the tissues). While certain efforts have been undertaken to reduce the trauma to tissue while creating an operative corridor, such as (by way of example only) the sequential dilation system of U.S. Pat. No. 5,792,044 to Foley et al., these attempts are nonetheless limited in their applicability based on the relatively narrow operative corridor. More specifically, based on the generally cylindrical nature of the so-called “working cannula,” the degree to which instruments can be manipulated and/or angled within the cannula can be generally limited or restrictive, particularly if the surgical target site is a relatively deep within the patient. Efforts have been undertaken to overcome this drawback, such as shown in U.S. Pat. No. 6,524,320 to DiPoto, wherein an expandable portion is provided at the distal end of a cannula for creating a region of increased cross-sectional area adjacent to the surgical target site. While this system may provide for improved instrument manipulation relative to sequential dilation access systems (at least at deep sites within the patient), it is nonetheless flawed in that the deployment of the expandable portion may inadvertently compress or impinge upon sensitive tissues adjacent to the surgical target site. For example, in anatomical regions having neural and/or vasculature structures, such a blind expansion may cause the expandable portion to impinge upon these sensitive tissues and cause neural and/or vasculature compromise, damage and/or pain for the patient. This highlights yet another drawback with the prior art surgical access systems, namely, the challenges in establishing an operative corridor through or near tissue having major neural structures which, if contacted or impinged, may result in neural impairment for the patient. Due to the threat of contacting such neural structures, efforts thus far have largely restricted to establishing operative corridors through tissue having little or substantially reduced neural structures, which effectively limits the number of ways a given surgical target site can be accessed. This can be seen, by way of example only, in the spinal arts, where the exiting nerve roots and neural plexus structures in the psoas muscle have rendered a lateral or far lateral access path (so-called trans-psoas approach) to the lumbar spine virtually impossible. Instead, spine surgeons are largely restricted to accessing the spine from the posterior (to perform, among other procedures, posterior lumbar interbody fusion (PLIF)) or from the anterior (to perform, among other procedures, anterior lumbar interbody fusion (ALIF)). Posterior-access procedures involve traversing a shorter distance within the patient to establish the operative corridor, albeit at the price of oftentimes having to reduce or cut away part of the posterior bony structures (i.e. lamina, facets, spinous process) in order to reach the target site (which typically comprises the disc space). Anterior-access procedures are relatively simple for surgeons in that they do not involve reducing or cutting away bony structures to reach the surgical target site. However, they are nonetheless disadvantageous in that they require traversing through a much greater distance within the patient to establish the operative corridor, oftentimes requiring an additional surgeon to assist with moving the various internal organs out of the way to create the operative corridor. The present invention is directed at eliminating, or at least minimizing the effects of, the above-identified drawbacks in the prior art. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention accomplishes this goal by providing a novel access system and related methods which involve detecting the existence of (and optionally the distance and/or direction to) neural structures before, during, and after the establishment of an operative corridor through (or near) any of a variety of tissues having such neural structures which, if contacted or impinged, may otherwise result in neural impairment for the patient. It is expressly noted that, although described herein largely in terms of use in spinal surgery, the access system of the present invention is suitable for use in any number of additional surgical procedures wherein tissue having significant neural structures must be passed through (or near) in order to establish an operative corridor. According to one broad aspect of the present invention, the access system comprises a tissue distraction assembly and a tissue retraction assembly, both of which may be equipped with one or more electrodes for use in detecting the existence of (and optionally the distance and/or direction to) neural structures. The tissue distraction assembly (in conjunction with one or more elements of the tissue retraction assembly) is capable of, as an initial step, distracting a region of tissue between the skin of the patient and the surgical target site. The tissue retraction assembly is capable of, as a secondary step, being introduced into this distracted region to thereby define and establish the operative corridor. Once established, any of a variety of surgical instruments, devices, or implants may be passed through and/or manipulated within the operative corridor depending upon the given surgical procedure. The electrode(s) are capable of, during both tissue distraction and retraction, detecting the existence of (and optionally the distance and/or direction to) neural structures such that the operative corridor may be established through (or near) any of a variety of tissues having such neural structures which, if contacted or impinged, may otherwise result in neural impairment for the patient. In this fashion, the access system of the present invention may be used to traverse tissue that would ordinarily be deemed unsafe or undesirable, thereby broadening the number of manners in which a given surgical target site may be accessed. The tissue distraction assembly may include any number of components capable of performing the necessary distraction. By way of example only, the tissue distraction assembly may include a K-wire, an initial dilator of split construction, and one or more dilators of traditional (that is, non-split) construction for performing the necessary tissue distraction to receive the remainder of the tissue retractor assembly thereafter. One or more electrodes may be provided on one or more of the K-wire and dilator(s) to detect the presence of (and optionally the distance and/or direction to) neural structures during tissue distraction. The tissue retraction assembly may include any number of components capable of performing the necessary retraction. By way of example only, the tissue retraction assembly may include one or more retractor blades extending from a handle assembly. The handle assembly may be manipulated to open the retractor assembly; that is, allowing the retractor blades to separate from one another simultaneously to create an operative corridor to the surgical target site. In a preferred embodiment, this is accomplished by maintaining a posterior retractor blade in a fixed position relative to the surgical target site (so as to avoid having it impinge upon any exiting nerve roots near the posterior elements of the spine) while the additional retractor blades (i.e. cephalad-most and caudal-most blades) are moved or otherwise translated away from the posterior retractor blade (and each other) so as to create the operative corridor in a fashion that doesn't infringe upon the region of the exiting nerve roots. The retractor blades may be optionally dimensioned to receive and direct a rigid shim element to augment the structural stability of the retractor blades and thereby ensure the operative corridor, once established, will not decrease or become more restricted, such as may result if distal ends of the retractor blades were permitted to “slide” or otherwise move in response to the force exerted by the displaced tissue. In a preferred embodiment, only the posterior retractor blade is equipped with such a rigid shim element. In an optional aspect, this shim element may be advanced into the disc space after the posterior retractor blade is positioned, but before the retractor is opened into the fully retracted position. The rigid shim element is preferably oriented within the disc space such that is distracts the adjacent vertebral bodies, which serves to restore disc height. It also preferably advances a sufficient distance within the disc space (preferably past the midline), which serves the dual purpose of preventing post-operative scoliosis and forming a protective barrier (preventing the migration of tissue (such as nerve roots) into the operative field and the inadvertent advancement of instruments outside the operative field). The retractor blades may optionally be equipped with a mechanism for transporting or emitting light at or near the surgical target site to aid the surgeon's ability to visualize the surgical target site, instruments and/or implants during the given surgical procedure. According to one embodiment, this mechanism may comprise, but need not be limited to, providing one or more strands of fiber optic cable within the walls of the retractor blades such that the terminal (distal) ends are capable of emitting light at or near the surgical target site. According to another embodiment, this mechanism may comprise, but need not be limited to, constructing the retractor blades of suitable material (such as clear polycarbonate) and configuration such that light may be transmitted generally distally through the walls of the retractor blade light to shine light at or near the surgical target site. This may be performed by providing the retractor blades having light-transmission characteristics (such as with clear polycarbonate construction) and transmitting the light almost entirely within the walls of the retractor blade (such as by frosting or otherwise rendering opaque portions of the exterior and/or interior) until it exits a portion along the interior (or medially-facing) surface of the retractor blade to shine at or near the surgical target site. The exit portion may be optimally configured such that the light is directed towards the approximate center of the surgical target site and may be provided along the entire inner periphery of the retractor blade or one or more portions therealong. | 20040227 | 20101026 | 20090514 | 95896.0 | A61B132 | 2 | HAMMOND, ELLEN CHRISTINA | SURGICAL ACCESS SYSTEM AND RELATED METHODS | UNDISCOUNTED | 0 | ACCEPTED | A61B | 2,004 |
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10,789,816 | ACCEPTED | Wireless telephone data backup system | A system for backing up data on a wireless telephone having a data store containing a user's personal information. A method and application are provided. | 1. A method for backing up personal information stored in a telephone, comprising: presenting a back-up system user account set-up interface on the phone; presenting a backup scheduling interface on the phone; and presenting a restore information interface on the phone. 2. The method of claim 1 wherein the user account setup interface calls a method allowing the user to set up a backup account with a backup store. 3. The method of claim 1 wherein the backup scheduling interface sets an interval to regularly send personal information to the backup store. 4. The method of claim 1 wherein the backup scheduling interface causes the transmission of personal information to the backup store upon modification of the information on the phone. 5. The method of claim 1 wherein the restore interface calls a method to upload all stored information on the server to the phone. 6. The method of claim 5 wherein the method further includes providing a rollback interface. 7. The method of claim 6 wherein the rollback interface is accessed via a web browser. 8. The method of claim 6 where the rollback interface is accessed via a wireless protocol. 9. The method of claim 6 wherein the rollback interface calls a method uploading changes based on a particular date 10. The method of claim 1 wherein the method further includes providing an undelete interface. 11. The method of claim 10 wherein the undelete interface is accessed via a web browser. 12. The method of claim 10 wherein the undelete interface is accessed via a wireless protocol such as WAP. 13. The method of claim 10 wherein the undelete interface calls a method which transmits a change associated with a particular record in a user's personal information space. 14. The method of claim 1 wherein said personal information comprises an address book data store. 15. The method of claim 1 wherein said personal information comprises an task entry data store 16. The method of claim 1 wherein said personal information comprises an calendar entry data store 17. The method of claim 1 wherein said personal information comprises a note entry data store 18. The method of claim 1 wherein said personal information comprises an alarm data store 19. The method of claim 1 wherein said personal information comprises a custom dictionary data store. 20. A method for storing personal information in a wireless telephone in a backup storage database, comprising: providing a phone agent including an automated phone data transmission method capable of regularly transmitting changes to a backup store via a communications link and a restore method; and responsive to said agent, providing changes from the backup store to the wireless telephone. 21. The method of claim 20 wherein the method further includes accepting personal information from the telephone at intervals defined by the user. 22. The method of claim 20 wherein the method further includes accepting user account set-up data from the agent. 23. The method of claim 20 wherein the method further includes assigning a schedule of download intervals to the agent. 24. The method of claim 21 wherein the method further includes modifying the interval schedule to load balance amongst a plurality of users. 25. The method of claim 20 further including providing a notification to the agent that changes have been made to the backup store via a secondary interface. 26. The method of claim 25 wherein the phone agent updates phone upon receipt of a notification. 27. The method of claim 25 wherein the notification is a SMS message. 28. The method of claim 20 wherein the notification is a result of polling the server for changes. 29. The method of claim 25 wherein the method further includes providing the secondary interface and the secondary interface is a web interface. 30. A method for maintaining personal information in a wireless telephone, comprising: establishing a user account, the user account identifying the user by an unique designation; and transmitting phone data to a backup store via a wireless network at regular intervals. 31. The method of claim 30 wherein the step of transmitting includes transmitting phone data at user-defined intervals 32. The method of claim 30 wherein the step of transmitting occurs upon receipt of an indication from backup store that changes to data on the data store have occurred. 33. The method of claim 32 wherein the indicator is an SMS message. 34. The method of claim 32 wherein the indicator is a result of polling the backup store to determine if changes have occurred. 35. The method of claim 30 wherein the step of transmitting includes transmitting only changes to phone data. 36. The method of claim 35 wherein the step of transmitting includes transmitting only changes to phone data in the form of change logs. 37. The method of claim 36 wherein the method further includes the step of restoring data to the phone by applying all change logs. 38. The method of claim 30 further including the step of providing an interface to the store via the web to alter data in the data store. 39. The method of claim 38 further including the step transmitting data changed by the interface to the phone at a user scheduled interval. 40. The method of claim 38 further including the step transmitting data changed by the interface to the phone at upon a user initiated action. 41. The method of claim 38 further including the step transmitting data changed by the interface to the phone at a server-directed interval. 42. An application for a wireless telephone, comprising: an automated backup process transmitting changes to the backup system at user defined intervals; and a restore process activated by a user to restore information stored on the backup system to the phone. 43. The application of claim 42 wherein the application further includes a rollback phone information process. 44. The application of claim 43 wherein rollback information process returns data on the wireless to a state existing on a specified date. 45. The application of claim 42 wherein the application further includes an undelete record process. 46. The application of claim 42 wherein the application includes a BREW agent. 47. The application of claim 42 wherein the application includes a JAVA agent. 48. The application of claim 42 including a SyncML communications module. 49. The application of claim 48 wherein the application operates to transmit changes from the backup system to the phone. 50. The application of claim 49 wherein the SyncML communications module includes a SyncML client. 51. The application of claim 48 wherein the SyncML communications module communicates with a SyncML client in the telephone. 52. An application for storing personal information in a wireless telephone having a data store to a backup system, comprising: an automated user account creation method accessing the backup system using a unique identifier for the user to create a user account on the backup system; an automated backup method transmitting changes to the backup system at user defined intervals; and a restore method providing user data to a phone. 53. The application of claim 52 wherein the application includes a rollback method providing a state of user data existing as of a specified date. 54. The application of claim 52 wherein the application includes an undelete method providing at lease one restored data item previously deleted by a user action. 55. The application of claim 52 wherein at least the backup method and the account creation method are initiated by the agent. 56. The application of claim 52 wherein the intervals are defined by user but altered by administrator. 57. The application of claim 52 wherein the intervals are regular. 58. The application of claim 52 wherein the intervals are arbitrary. 59. The application of claim 52 wherein the restore method operates responsive to a phone recognized as having no data and an existing user account. 60. The application of claim 52 wherein the account creation method is performed by the backup system via a secondary interface provided to the user. 61. One or more processor readable storage devices having processor readable code embodied on said processor readable storage devices, said processor readable code for programming one or more processors to perform a method comprising the steps of: presenting a backup scheduling interface; transmitting an initial set of phone data and changes to the phone data over time to a backup system; and presenting a restore information interface. 62. One or more processor readable storage devices as defined in claim 61 wherein the method further includes the steps of presenting a user account setup interface. 63. One or more processor readable storage devices as defined in claim 62 wherein the setup interface is on the phone. 64. One or more processor readable storage devices as defined in claim 62 wherein the setup interface is presented via a world wide web interface. 65. One or more processor readable storage devices as defined in claim 61 wherein the backup scheduling interface is provided on the phone. 66. One or more processor readable storage devices as defined in claim 62 wherein the backup scheduling interface is provided via a world wide web interface. 67. One or more processor readable storage devices as defined in claim 61 wherein the restore information interface is provided on the phone. 68. One or more processor readable storage devices as defined in claim 62 wherein the restore information interface is provided via a world wide web interface. 69. One or more processor readable storage devices as defined in claim 62 wherein the method includes the step of sending data to the phone from the data store responsive to restore information interface. 70. A backup system for personal information in a mobile phone, comprising: a set of personal information stored on a backup system identified with a user identifier and a phone identifier. 71. The backup system of claim 70 wherein the system includes an auto account creation process utilizing the phone identifier to configure data associated with the phone. 72. The backup system of claim 70 wherein the user identifier is a universally unique identifier. 73. The backup system of claim 70 wherein the phone identifier is a universally unique identifier. 74. The method of claim 4 wherein the backup scheduling interface causes the transmission of personal information to the backup store immediately modification of the information on the phone. 75. The method of claim 4 wherein the backup scheduling interface causes the transmission of personal information to the backup store upon modification of the information on the phone at a point in time separated from the modification. 76. The method of claim 6 where the rollback interface is accessed via the phone agent. 77. The method of claim 6 where the undelete interface is accessed via the phone agent. 78. The method of claim 1 wherein said personal information comprises an email data store. 80. The method of claim 1 wherein said personal information comprises an multimedia data store for pictures, sounds, and movies. 81. The method of claim 1 wherein said personal information comprises an ringtone data store. | BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to the backup and restoration of data stored in a wireless telephone, and in particular a mobile telephone having data storage capabilities. 2. Description of the Related Art Wireless communication devices, such as mobile telephones, have expanded beyond merely mechanisms for communication. Many telephones include features enabling personal productivity, games and even digital cameras. Devices which include personal productivity applications may include data storage for storing the owner's personal information within the storage devices. In addition, phones now have the ability to run application programs specifically designed for phone-based runtime environments. All of an individual's personal information operated on and stored by a user can be considered within that user's “personal information space.” In this context, a “personal information space” is a data store of information customized by, and on behalf of the user which contains both public data the user puts into their personal space, private events in the space, and other data objects such as text files or data files which belong to the user and are manipulated by the user. The personal information space is defined by the content which is specific to and controlled by an individual user, generally entered by or under the control of the individual user, and which includes “public” events and data, those generally known to others, and “private” events and data which are not intended to be shared with others. It should be recognized that each of the aforementioned criteria is not exclusive or required, but defines characteristics of the term “personal information space” as that term is used herein. In this context, such information includes electronic files such as databases, text files, word processing files, and other application specific files, as well as contact information in personal information managers, PDAs and cellular phones. One difficulty users face is that it can be time consuming to enter information into a telephone, and once entered, the information is subject to loss. If the phone is damaged or simply lost by the user, and the time and effort spent to enter the information into the phone is lost. Some phones come with software and data connection cables allowing users to enter and backup information stored on a telephone by physically connecting the telephone to a personal computer. Many of these applications are provided by the manufacturer of the phone and are customized to interact directly with the phone. That is, the application program generally specifically designed for the telephone to retrieve data from the telephone and store it in the application on a personal computer. In addition, some third party vendors have attempted to make more universal synchronization systems that interact with phones through the physical cable. The trouble with these physical connection mechanisms is that the user must consciously remember to physically connect the phone to the computer on a regular basis in order to ensure that the information backed up on the computer is accurate. In addition, the computer itself is subject to volatility. The data on the computer may be lost or damaged due to hardware and software failures. While phone users generally desire increased functionality in phone based applications, they also desire the applications be relatively easy to use. Even general computer based utility applications, such as data back-up applications, are advantageous if they are set to run without significant user intervention. An application which would allow wireless phone users to quickly and easily backup their personal information stored on the telephone would be of great commercial and technical value. SUMMARY OF THE INVENTION The invention comprises a system for backing up data on a wireless telephone having a data store containing a user's personal information. A method and application are provided, and various aspects and variations of the system are described herein. The invention provides a convenient means for a user to ensure that information saved on a wireless phone, and the effort spent to ensure that information is entered and correct, are not lost if the phone itself is lost or damaged. The invention, in one aspect, comprises a method for backing up personal information stored in a telephone. In this aspect, the method may include the steps of presenting a back-up system user account set-up interface on the phone; presenting a backup scheduling interface on the phone; and presenting a restore information interface on the phone. In a further aspect, the method may include transmitting phone data to the backup system at user-defined intervals, or upon receipt of an indication from backup store that changes to data on the data store have occurred. The indicator may a result of polling the backup store to determine if changes have occurred. The method may further include the step of providing an interface to the store via the web to alter data in the data store. The method may include further providing a roll-back interface and an undelete interface. In yet another aspect, the invention is a method for storing personal information in a wireless telephone in a backup storage database. In this aspect, the method may comprise the steps of: providing a phone agent including an automated phone data transmission method capable of regularly transmitting changes to a backup store via a communications link and a restore method; and responsive to said agent, providing changes from the backup store to the wireless telephone. In a still further aspect, the invention is a method for maintaining personal information in a wireless telephone. In this aspect, the method includes the steps of establishing a user account, the user account identifying the user by an unique designation; and transmitting phone data to a backup store via a wireless network at regular intervals. In another embodiment, the invention is an application for a wireless telephone. The invention includes an automated backup process transmitting changes to the backup system at user defined intervals. In addition, the application may include a restore process activated by a user to restore information stored on the backup system to the phone. The application may include a rollback phone information process which returns data on the wireless to a state existing on a specified date. The application may further include an undelete record process. The application may include one or more processes running on a server, a BREW agent and/or a JAVA agent or an application designed to operate on a proprietary device or operating system (e.g., a Symbian operating system.) In yet another embodiment, the invention is an application for storing personal information in a wireless telephone having a data store to a backup system. The application includes an automated user account creation method accessing the backup system using a unique identifier for the user to create a user account on the backup system; an automated backup method transmitting changes to the backup system at user defined intervals; and a restore method providing user data to a phone. In another embodiment, the invention comprises one or more processor readable storage devices having processor readable code embodied on said processor readable storage devices, said processor readable code for programming one or more processors to perform a method comprising the steps of: presenting a backup scheduling interface; transmitting an initial set of phone data and changes to the phone data over time to a backup system; and presenting a restore information interface. In a still further aspect, the invention is a backup system using a unique phone identifier in conjunction with personal information stored for a user. In a further aspect, the backup system associates a unique phone identifier with a unique user identifier. In a still further aspect, the phone identifier, the user identifier or both are universally unique. In a further aspect; the invention includes using an existing SyncML client on the phone as the backup client and auto creating the user account info on the server. The present invention can be accomplished using hardware, software, or a combination of both hardware and software. The software used for the present invention is stored on one or more processor readable storage media including hard disk drives, CD-ROMs, DVDs, optical disks, floppy disks, tape drives, RAM, ROM or other suitable storage devices. In alternative embodiments, some or all of the software can be replaced by dedicated hardware including custom integrated circuits, gate arrays, FPGAs, PLDs, and special purpose computers. These and other objects and advantages of the present invention will appear more clearly from the following description in which the preferred embodiment of the invention has been set forth in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described with respect to various exemplary embodiments thereof. Other features and advantages of the invention will become apparent with reference to the specification and drawings in which: FIG. 1 is a block diagram illustrating the wireless telephone coupling to a backup server utilized in accordance with the present invention. FIG. 2 is a flow chart illustrating how a user might sign up for and initially backup data using the system and the present invention. FIGS. 3a through 3q are screen shots illustrating how a user interface would allow a user to sign and initially backup data in the system of the present invention. FIG. 4 is a flow chart illustration a restore process utilized in accordance with the present invention. FIGS. 5a through 5e illustrate user interface for conducting your restore process in accordance with the present invention. FIG. 6 is a flow chart illustrating a rollback feature utilized in accordance with the present invention. FIG. 7 is a flow chart illustrating user interaction with a web-based personal information manager to alter the data in the backup store and subsequently the information stored on the wireless telephone. FIG. 8 is an alternative embodiment of the process shown in FIG. 7 illustrating user interaction with a web-based personal information manager which modifies user information stored on a wireless telephone. FIG. 9 is a flow chart illustrating how two different states of data may occur and options for resolving those states. FIG. 10 illustrates a method for implementing a backup system using a unique phone identifier associated with user data. FIG. 11 illustrates a method for using a pre-provisioned manufacturer provided SyncML client on a phone to communicate with the backup server. FIG. 12 illustrates a method for provisioning a manufacturer provided SyncML client on a phone to communicate with the backup server. DETAILED DESCRIPTION The present invention allows a user to wirelessly backup personal information stored on a cellular telephone using the wireless communication link, such as a wireless network, to which the phone can connect. The application results in a process which runs generally in the background of the user's phone application and therefore does not inhibit the user's use of the phone. FIG. 1 illustrates a general overview of a system for implementing the present invention. As shown in FIG. 1, a wireless communication device, such as a phone 100, is connected to a wireless communications link, such as a cellular network 150, to transmit voice and data communications to other devices coupling to the wireless network. Data may be transmitted over the network in any number of known formats. A server 160 is also provided which communicates via a wireless link 185 with the telephone via wireless network 150. Alternatively, server 160 may communicate with phone 100 via a SyncML server 195. The backup system includes the agent 110, the backup store 150 on server 160, and methods implemented by the agent and server to perform the backup, restore and data integrity functions of the invention. Other components discussed herein may also be incorporated into the system in various embodiments. Phone 100 is provided with a backup application or agent 110. Backup agent 110 can be a SyncML communication client designed to interact with a SyncML server 195 in accordance with approved and proposed versions of the SyncML OMA DS specification, including proposed extensions, (available at http://www.openmobilealliance.org). Alternatively, agent 110 can be an application designed to communicate with server 160 using an existing SyncML client on the phone provided by the phone's manufacturer (as well as any custom extensions supported by such client), or an application specifically designed to communicate with server 160 via another protocol, including a proprietary protocol. In one embodiment, the agent 110 is a fully implemented SyncML client and server 160 includes a SyncML server. In another embodiment, the application 110 is a client application device sync agent such as that disclosed in U.S. Pat. No. 6,671,757. In yet another embodiment, the application 110 is a client application responsive to control via a browser in the phone, with the application checking for changes to data on the phone and implements the processes described herein. In general, a hardware structure suitable for implementing server 160, webserver 180 or SyncML server 195 includes a processor 114, memory 104, nonvolatile storage device 106, portable storage device 110, network interface 112 and I/O device(s) 116. The choice of processor is not critical as long as a suitable processor with sufficient speed is chosen. Memory 104 could be any conventional computer memory known in the art. Nonvolatile storage device 106 could include a hard drive, CDROM, CDRW, flash memory card, or any other nonvolatile storage device. Portable storage 108 could include a floppy disk drive or another portable storage device. The computing system may include one or more network interfaces 112. An example of a network interface includes a network card connected to an Ethernet or other type of LAN. I/O device(s) 114 can include one or more of the following: keyboard, mouse, monitor, display, printer, modem, etc. Software used to perform the methods of the present invention are likely to be stored in nonvolatile storage 106, portable storage media 110 and/or in memory 104. The computing system also includes a database 108, which can be stored in nonvolatile storage 106. In alternative embodiments, database 108 is stored in memory 104, portable storage 110 or another storage device that is part of the system of FIG. 1 or is in communication with the system of FIG. 1. Other alternative architectures can also be used that are different from that depicted in FIG. 1. Various embodiments, versions and modifications of systems of FIG. 1 can be used to implement a computing device that performs all or part of the present invention. Examples of suitable computing devices include a personal computer, computer workstation, mainframe computer, handheld computer, personal digital assistant, pager, cellular telephone, smart appliance or multiple computers, a storage area network, a server farm, or any other suitable computing device. There may be any number of servers 160n, n+1 managed by a system administrator providing a back up service in accordance with the present invention. Also provided on server 160 is a backup data store 510. The backup data store is provided in the non-volatile memory space of server 160. While only one backup data store computer is shown, it should be recognized that the store may be replicated to or stored over a plurality of computers (160n, 160n+1) to ensure that the data thereon is protected from accidental loss. It should be understood that the representation of the SyncML server 195 and web sever 180 need not require that such servers be provided on different physical hardware than the backup server 160. In accordance with the invention, application agent 110 communicates personal information and changes made to the personal information stored in the data store of the telephone 100 to server 160 via the wireless network. Communication of user data from the device may take several forms. Where the client is a SyncML client in communication with the server 160, communication may take place using the standards set forth in the SyncML specification. Changes are transmitted on a record-by-record basis or field-by-field basis. Alternatively, communication may occur via another protocol. In an alternative embodiment, agent 110 is a self-supporting application designed to run as a JAVA or BREW agent, or any other device or operating system specific agent (such as an agent operable on the Symbian Operating system). This agent can either include its own SyncML client, or interact with an existing SyncML client on the telephone. Changes can occur at field level or byte level. Alternative embodiments can communicate via alternative protocols via the wireless communications link to store information on the backup data base 510. The server 160 stores user data in the backup store in a manner which associates the data with the user of the phone. In one embodiment the data is stored in bulk—that is all records and information for the user are stored in simple text form, or a copy of the entire database from the phone is stored on the server. In this embodiment, the server may store any number of copies of the data on a date-identified basis. Alternatively, the server 160 translates this information into change logs, in one embodiment, in accordance with the teachings of U.S. Pat. No. 6,671,757. This information is stored in backup data store 510 on server 160. This information is stored in the data store using a unique identifier (UID) associating the data with the individual user. The identifier may be any randomly selected identifier, so long as the user is uniquely identified, and the data is associated with the user. In a further aspect, this user UID may be a universally unique identifier (UUID), created in a manner described in the aforementioned U.S. Pat. No. 6,671,757 or other manners to create a single ID for a given user. Data store 150 can be any form of data storage for the user data. In one embodiment, the data store is a simple copy of the information stored on the device 100. In another embodiment, the data store is a database, such as an object database or a relational database. In yet another embodiment, the data store is simply a storage container for change logs created in accordance with U.S. Pat. No. 6,671,757. A web server 180 allowing a user on a computer or other device 190 having a web browser may optionally be provided to allow a user to configure aspects of the system of the invention. Server 180 may have a hardware configuration similar to computer 160 and may comprise one or more physical computers. Additionally, web server 180 may be integrated with server 160. In general, a first embodiment of the system described below presents a system whereby certain aspects of the backup system of the present invention are configured via a phone interface. In each case where a phone interface is used, the system can alternatively be configured by a user via a web interface provided by the web server 180 via the user device 190. FIG. 2 illustrates how a user interacting with the system on the present invention for the first time would install the application and sign up for the backup service provided by a system administrator using the backup server 160 and the user's phone 100. In the embodiment of FIG. 2, a user signs up for a backup service provided by a system administrator using the user's telephone and the application 110. An alternative sign-up process may be implemented by having the user initiate service by going to a World Wide Web site administered by the system administrator and interacting with or being provided by the system server 160. Still another method for sign up would be to allow the user to sign up via a specially formatted Wireless Application Protocol site which can be accessed by a WAP browser on the phone 100. (Another approach, discussed below with respect to FIGS. 10-12 involves the automatic creation of a user account using a phone unique identifier.) The system administrator controls and maintains the server 160, and provides the agent 110 for the phone. Alternatively, the agent may be provided by a phone manufacturer and designed to communicate with server 160 (directly or thought SyncML server 195). The agent may be pre-loaded on the phone prior to distribution by the manufacturer or wireless service carrier, or provided for download by the administrator via the wireless network. In the latter embodiment, a user initially downloads the application from a system administrator via the communication link 185. In general, wireless carriers now provide many forms of downloadable applications for intelligent telephones having the ability to run the applications in a BREW or JAVA. BREW (Binary Runtime Environment for Wireless) is an open source application development platform for wireless devices equipped for code division multiple access (CDMA) technology. Likewise, JAVA or J2ME (Java 2 Micro Edition) are similar platforms from Sun Microsystems. Once the application is installed, at step 202 in FIG. 2, the user contacts the backup site 160 using the phone 100 and application 110. The manner in which this might be presented to the user is illustrated in FIGS. 3a and 3b. A welcome screen is shown in FIG. 3a prompting the user select button 302 on wireless phone 300 to move to the “next” screen shown in FIG. 3b. As will be understood by those of average skill in the art, a cellular telephone 300 shown in FIGS. 3a through 3q includes “soft” buttons 302 and 304. The menu items appearing at the lower portion of the screen indicated by reference numerals 306 and 308 are the commands which change relative to the display and are controlled by the application 110 (and other types) running on the cellular telephone 300. In FIG. 3a, a “next” button and a “cancel” button are shown. Buttons 302 and 304 control the “next” and “cancel” functions, respectively. Once the user agrees to connect to the site, as shown in FIG. 3b, the user is presented with a screen illustrating the phone is connecting to the wireless network. The user's mobile number as shown at reference numeral 312 is displayed. Returning to FIG. 2, at step 204, the user may be prompted to agree to a software license and license for using the service. This is illustrated in FIG. 3c. If the user does not agree at step 206, the process ends. If the user agrees, then at step 208, the phone downloads the user number as an ID. At step 210, the user selects and confirms a PIN. This is illustrated in FIGS. 3d through 3f. In FIG. 3d, the user enters a registration PIN into the phone and selects the next command by depressing soft button 302. In FIG. 3e, the phone displays the enter PIN and prompts the user to save the pin code. The user moves on to the next screen by depressing soft button 302. This screen in shown in FIG. 3f prompting the user to select an option for the service to return the PIN to the phone should the user forget the PIN. Returning to FIG. 2, following completion of step 210 in FIG. 2, the user is prompted to set a backup schedule at step 212. This setup process is shown in FIGS. 3g through 3j. In FIG. 3g, the user is prompted to set the schedule by depressing the soft button 302. In FIG. 3h, four options are displayed for the user to select a regularly recurring schedule. These options are “every day”, “week days”, “weekly”, or “unscheduled”. When the user selects the next button in FIG. 3h, the daily backup screen is shown in FIG. 3i. The daily backup allows the user to set a specific time for the regularly scheduled backups. If the user selects a weekday schedule, this time can also occur at the same interval every day. The weekly schedules (selection 3 in FIG. 3) function in a similar manner. The “unscheduled” backup option allows the user to manually backup information on the phone by manually initiating the application and sending changes to the backup store as illustrated at step 222 in FIG. 2. In yet another embodiment, the scheduling can be to provide backup data to the server every time the user changes information on the phone. In yet another embodiment, scheduling is at least partially controlled by the server 160. In this embodiment, when the user attempts to set a scheduling time, the server 160 checks a separately kept record of the backup transmission schedules of other users to ensure that load balancing of the transmissions of various users occurs on the server. If, for example, a user desires to send backup data every day at 8 AM, and a number of users desire the same time, the system can instruct the application 110 to alter its schedule in a manner which does not significantly impact the schedule for the user. This change can ensure that the server 160 has sufficient communications bandwidth and processing power to handle concurrent requests which may be occurring at or near the same scheduling time as the user's selected time. In another embodiment, backup scheduling is controlled entirely by the server. In this aspect, the user is not provided with an interval selection, and the server can schedule interval backups (at regular, irregular or arbitrary times). In yet another embodiment, backup data is transmitted at some point after each change to the phone's data store. Again returning to FIG. 2, once the backup scheduled has been set at step 212 in FIG. 2, the initial backup information must be stored on the server 160. This occurs at step 214 and is illustrated in FIGS. 3j through 3m. In FIG. 3j, once the setup is complete, the user is prompted to press the “next” soft button 302 to begin the initial backup process. Upon depressing the “next” soft button 302 as shown in FIG. 3k, the phone connects to the backup server 160, and at FIG. 3l the information is transmitted to the backup server. The items field 320 shown in the screen in FIG. 3l keeps a running count of the items being sent to backup server 160. When the backup is complete, FIG. 3m shows the status screen displayed by the phone upon completion of the backup process. At this point, at the lower portion of the screen, soft buttons 302 and 304 present the user with a “backup now” option, allowing the user to manually send information to the phone as indicated at step 222 in FIG. 2, and a “options” button. The “options” button allows the user to select various administrative functions in accordance with the backup process. For example, the options might allow the user to change the schedule of the backup process, due to the user's mobile number account which is identified to the backup system 160, change the user PIN, access the help feature, or access information about the agent 110. Returning to FIG. 2, once the status screen is shown in FIG. 216, the user may continue to use this telephone in the manner that the user is normally accustomed to. At a later point and time as indicated by the dashed interval between steps 216 and 218, the backup interval set by the user's schedule will be reached. At this point, changes and additions and deletions will be sent to the backup store. This is illustrated in FIGS. 3n through 3q. In FIG. 3n, the application may display a status screen to the user, in FIG. 3o display that it is connecting to the backup server 160, in FIG. 3p display the items being backed up, and in FIG. 3q display the status of the backup as completed. It should be recognized that the interval 218 may in fact comprise a manually initiated event as shown at step 222. It should be further recognized that steps 218 and 220 may occur in the background, and no indication may be provided to the user. That is, once the backup interval is reached, the phone may simply download additions, deletions or changes to the user and keep a record of when it performed its last backup so the user can check to ensure that the backup process is running on a regular basis. The matter of interaction between the application and the user (e.g. how much information the application provides to the user about its activities) can be selected by the user. In an alternative embodiment, an indicator such as a “pop-up” information message may be provided to the user at competition of the backup. Users can select whether and how often to receive information messages. FIG. 4 shows a flow chart overview of the restore process utilized in accordance with this present invention. FIGS. 5a through 5e illustrate the steps which a user might view at a user interface during the restore process. At step 402, the user activates the application. This may occur, for example, when a user obtains a new telephone or the memory of the user's current telephone is wiped out for some unknown reason. Once the user activates the application, a status screen as shown in FIG. 5a is displayed. Returning to FIG. 4, at step 404, the device agent transmits the user's unique identifier to the server. In step 406, the identifier is indicated as being the user's phone number and this identifies the user to the backup system. Alternatively, the method may prompt the user to indicate whether the user has previously set up an account with the system administrator and request the user's original identifier and PIN. As this is an initial use of the application on a phone containing no user data, in one embodiment, the server can recognize that no data is present in the phone and prompt the user to do a restore, the application will promptly recognize the user as an account holder at step 406. The application will then prompt the user to enter a PIN at step 420. This is illustrated in FIG. 5c. Once the user enters the PIN at step 408, data will be restored to the device in step 410. This is illustrated in FIG. 5d which indicates to the user that the application is “restoring” the information to the phone. FIG. 5e shows a status screen displaying to the user that the information has in fact been returned to the user's phone. Alternative embodiments of the restore process may be utilized as well. In one alternative, the restore process may include providing information to a phone which has had information entered on it more recently than the backup store's state of the user's data. Suppose, for example, a user may has an account created with information in the backup store which creates a backup state, for example “state 1”, at a given time. If the user needs to perform a restore—such as if the user looses a phone and purchases a new one—the restore process could simply provide the state 1 information to the device. If, however, the user manually enters information on to the device thereby creating a discordance between the state 1 information in the backup store and the more recently entered phone data. In this discordance case, in one alternative, the state 1 information can be provided to the phone while ignoring any new information entered by the user on the phone (thereby making the backup store the primary information container and ignoring changes on the phone). In a second alternative, the agent can recognize that the phone is not equivalent to the phone used by the user to create the state 1 information (using for example a unique identifier for the phone, such as that discussed below, or some other means of identifying the new phone state—such as a user selection). Once the phone's state is established, the user's personal information stored in the phone is sent to the backup store, a process running on the server can resolve discrepancies or duplicates, and then write the new state of the user's data to the phone. In another alternative, the information on both the device and the backup store can be merged. In this latter alternative, a possibility of duplicate entries exists, and a mechanism for dealing with such duplicate entries (such as identifying them to the user and requesting which of the duplicates to keep) may be provided. Selection between such options may be given to the user during the setup process or under the options menu in the application or during restore, or on the web. Additionally, the system can provide additional options allowing the user to roll back the user's personal data to a particular date and time. This functionality can be implemented in a number of ways, but is particularly suited to use in the system of the present invention as implemented using the backup technology disclosed in U.S. patent application Ser. No. 09/641,028, U.S. patent application Ser. No. 09/642,615 and U.S. Pat. No. 6,671,757. The numerous advantages of the data backup technology in the U.S. Pat. No. 6,671,757 are discussed therein. However, it will be recognized that using such technology, one can re-create user data back to a particular date. Using such technology, the system starts with a first change-log or data package identified with a user and sequentially performs the actions defined therein on the data stored therein, searching for the change or date in question. When such change is reached, the item is “rolled back.” In this embodiment, a bookkeeping log may be kept in order to remove future changes for this object from later change logs associated with the user, or one could note the state of the record in its rolled-back state and add a new “modify” change-log to the datastore using the pre-rollback “current version” as the base. Alternatively, this feature may also be implemented using any number of other technologies, such a technology which stores all changes associated with the user, and during restore function only returns the most recent changes or recent setup data to the user. Alternatively, the data store may store a complete set of data for each backup the user makes, though this often provides a relatively data intensive scheme. This rollback option as illustrated in FIG. 6, once the use activates the application in step 602, the phone sends the unique identifier of the user (in one embodiment, the phone number) as the user identifier to the backup store 510 at step 660. At step 608, the application presents the user with an option to rollback a single or a group of contacts for a particular date. As step 608, once the user enters the PIN and the date of the rollback, and selects a single or group of contacts to be rolled back, the application restores the data from the storage server at step 610. Alternatively, the state of the data just prior to the performance of the rollback can itself be stored prior to the rollback function being performed. In a further embodiment, the agent can provide a “remember PIN” option, and store the PIN locally so the user does not need to re-enter the pin for each rollback or other identification function. In alternative embodiments of the invention, a web-interface may allow access to the backup store and the user may implement the rollback function via the web interface. For example, the interface can display a list of dates of each sync and the number of records or fields synced, and allow the user to roll back an individual or collective dated group of contacts to their state on a particular date. This interface can also be implemented via a WAP specific interface for the phone 100. FIG. 7 and FIG. 8 show yet another embodiment of the present invention when a user can optionally modify the data in the backup store using a separate interface. In one embodiment, the interface is a World Wide Web-based personal information manager which uses as its data source the backup store information or a mirror of such information which synchronizes to the backup store to modify the data in the backup store. In FIG. 7, the user, at step 702 accesses a web-based interface to the backup information data in the backup database. At step 704, the user modifies records which are initially generated from the user's wireless phone 100 using the web interface and the changes are stored in the backup database. At some point in the future, as indicated by the dashed line between steps 704 and 706, the user (or scheduler, in automated or controlled scheduling embodiments) activates the application on the phone 100 and at step 708, the phone transmits the user identifier such as the phone number to the system. Once the system server 160 recognizes that the particular user is a member of the system, the option to upload new and changed contacts which have been changed by the web access at step 702 is presented to the user. After the user enters a personal information number at step 702, and confirms the upload process, data is installed on the device at step 712. Alternatively, the upload need not be confirmed, may be prompt-less, or optionally prompt the user. In another embodiment, changes to the data store 150 can be made by using any of a number of commercially available products which allow data access to a users software personal information manager application, such as that described in U.S. Pat. No. 6,671,757. Such products extract information from personal information managers such as Microsoft Outlook and transfer it to alternative formats which can be read by other applications. FIG. 8 shows an alternative embodiment of the process in FIG. 7. Steps 702 and 704 occur as in the process illustrated in FIG. 7. In this embodiment, the application is active in the background on the phone and does not present the user with an option until the phone receives an SMS message at step 808 indicating to the application that changes to the data on the server have occurred. SMS (Short Message Service) is a service for sending messages of up to 160 characters (224 characters if using a 5-bit mode) to mobile phones. Following step 808, two optional processes may occur. At step 810, the user may be presented with an option to retrieve new and changed contacts from the server 160, and the information may be sent upon entry of the user's PIN at step 812 and confirmation of the upload process. When this occurs, data is installed in the device at step 814. Alternatively, as shown by line at 816, once the phone receives the SMS message indicating that changes to the data have occurred on the server, the agent will intercept the SMS message and retrieve changes made to the data store via the web interface automatically; the data may be installed on the device without any user intervention. Whether the application takes the manual route indicated by process line 818 or the automatic route indicated by process line 816 may be an option which user selects in a setup process which was not heretofore described in the setup of the application, or which is configured by the user administrator. In a still further embodiment, the phone agent 100 may not wait for an SMS message but may simply periodically poll the server to determine whether changes have occurred to the backup store. In yet another embodiment, the polling may determine whether changes have occurred on the phone relative to the backup data store, and transmit those changes to the data store. This embodiment is shown in FIG. 9. As shown therein, if a user modifies a record on the phone at step 902 and subsequently modifies a record on the backup store using the web interface at step 904, both before any changes on either the store or the phone are exchanged with the respective other device, the two states (state 1 and state 2) will be out of sync. At some time after the modifications at steps 902 and 904 as indicated by the dashed line between step 902, 904 and 908, with the application active in the background of the phone, some indication of the changes will occur. This is represented at step 908 and may occur when the phone receives an SMS message indicating changes have occurred, the polling of the server discussed above occurs, or the timed backup interval is reached. At this step 808, changes between the phone and the backup store are exchanged. As in FIG. 8, the data may be exchanged with user intervention (steps 910 and 912) or without (914). In addition, the conflict state discussed above with respect to the discordance case may occur, and the resolutions discussed above may likewise be implemented in this embodiment. In a still further embodiment, the SMS message may instruct the phone to download any changes made to the phone since it's last backup transmission to the backup store. A still further embodiment of the invention provides automation of the sign-up, account access and backup processes based on a unique phone identifier or phone UID which allows the system to determine more detailed functional information about the phone. In this embodiment, a phone UID may be associated with a user UID. In a further embodiment, the phone UID may be a universally unique phone ID (or phone UUID). In one embodiment, the phone UUID may comprise an IMEI or ESN. Each GSM phone contains an IMEI—International Mobile Equipment Identity number. This is a unique identifier assigned to all GSM devices. The IMEI is like a serial number and is used by the network to identify the handset (in conjunction with the SIM ID). The SIM ID is provided on a Subscriber Identity Module which is a small, stamp-size “smart card” used in a GSM phone. The SIM card contains a microchip that stores data that identifies the caller to the network service provider. The data is also used to encrypt voice and data transmissions, making it nearly impossible to listen in on calls. The SIM can also store phone book information—phone numbers and associated names. CDMA phones also have an individual identification number, the ESN. This number can be found on the back of a handset under the battery and is usually eight digits long, combining letters and numbers. The GSM Association (GSMA) has the role of the Global Decimal Administrator allocating International Mobile Equipment Identity Numbers (IMEI) to manufacturers for use in GSM. IMEI numbers are assigned to individual phones by the manufacturer and can identify the type, nature and characteristics of the phone to which they are assigned. A method for using a phone UID associated with the user's data is shown at FIG. 10. In some point prior to the phones being distributed to a user at step 1002, a phone UID is assigned to a user's phone. The phone UID may comprise an IMEI or other ID such as an ESN number as discussed above. Subsequently, at step 1004, the user acquires the phone and depresses a “backup” option on the phone. The backup option may be provided in an application agent as discussed above, or in an application specifically tailored for use on the phone, also discussed above. Initiating the backup function on the phone in step 1004 will begin a backup process in accordance with any of the aforementioned embodiments, but will allow a backup account to be automatically created using a phone UID and a user UID. At step 806, using the phone UID, the system can determine the characterization (the type, features, and functionality) of the phone based on the phone UID. This is particularly true in cases of GSM phones using an IMEI number. It will be further recognized that in step 1004, the user UID can be the SIM ID which is provided by the SIM in a GSM phone. Alternatively, the user UID may be the phone number or any other unique identifier for the user. At step 808, once both the phone UID and the user UID are known, a backup account can be automatically set up by the system without the need to know additional information from the user. Alternatively, additional authentication information may be required by the system, such as entry of a PIN. At step 808, each time the user stores backup information to the backup data store, the phone UID specifying the phone from which the information is obtained can be recorded. Hence, the backup data store will know when the user uses an alternative phone having a different phone UID to store information. At step 810, which may be separated in time from step 808 as indicated by the dash line between steps 808 and 810, the user initiates a backup data transmission using a new phone UID. This may occur, for example, when the user moves a SIM to a new phone in the GSM technology, or otherwise authenticates using his user UID any authentication required by the system. The authentication step 812 may be optional in cases where authentication is provided by the SIM ID or may be optionally disabled by the user. Once the system's detects, at step 810, that the user has provided a new phone UID, at step 814, the system records the new phone UID at step 816 and the system can automatically perform the system data restore transmitting changes to the new phone. In the situation shown in steps 810 through 816, because the user has switched the phone UID, it will be known to the system that the most recent backup state came from a different phone and the new phone UID will have a data state which is not current. Again, as in the discordance data state case discussed above, the user may enter data onto the new phone prior to performing initiation of the backup at step 810. In this case, the performance or data handling discussed above with respect to the discordance case can again be applied. FIGS. 11 and 12 show two alternatives to the manner in which step 1004 is performed. In accordance with the present invention, any communication between the phone and the serve 160 holding the backup store may occur though any number of protocols. In one embodiment, SyncML is used and in such embodiment, the agent 110 may have an integrated SyncML client or the manufacturer's SyncML client normally provided in the phone may be used. FIGS. 11 and 12 show methods for using the manufacturer's SyncML client. In FIG. 11, at step 1004, the phone is assumed to have shipped with a preconfigured SyncML client. By preconfigure, the SyncML client on the phone is shipped such that by depressing the backup (or sync) option in the agent, the phones' manufacturers sync agent has the identification information to access the SyncML server 495 shown in FIG. 1. At step 1102, where the phone ships with a preconfigured SyncML client, the phone UID and user UID are sent to the SyncML server when the user depresses the backup button on the phone. At step 1106, the user information and phone UID are associated in the backup data store, and an account is established at step 1108. At FIG. 12, the phone ships without a preconfigured SyncML client at step 1202. This is at 1204, optionally, the agent may need to be downloaded and installed on the phone at step 1204. At step 1206, upon initiation of the backup option in the phone application, configuration information can be sent via an SMS message to the phone manufacturer's SyncML client providing configuration provisioning information to the SyncML client. This allows the SyncML client on the phone to address the SyncML server 195 in FIG. 1. Next, the account establishment process at step 1208 begins using the phone UID and user UID. In the embodiment discussed with respects to FIGS. 10 through 12, user experience can be relatively unobtrusive. For example, the user need only press a “backup” soft button on the phone to have the account establish information transmitted to the backup data store. Any loss or change in the SIM to a different phone will result in the restore process being performed without any additional user intervention. Additionally, the administrator of the backup data store can make determinations about how much data to provide to the phone. For example, if the phone is identified based upon the phone UID is known to be a feature rich device, the administrator can backup all settings which are available on the phones such as the calendar, task, and phone book. If, upon switching phone UID's, the user moves to a less feature rich phone, the provider can determine that, for example, the new phone has only an address book, and provide only the address book data in the restore function. The user need not provide any configuration information to the administrator during this process. The foregoing detailed description of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. For example, tasks performed by the agent on the phone may be performed by the server as the result of a call to a code on the server instructing the server to perform the method and return data to the server. In addition, where authentication is required by the system, the user may be provided with the option to store the authenticating information in the phone or agent and not manually enter the authentication each time required. Still further, authentication can be transmitted by means of exchanged SMS messages. The functions described herein may be assigned to the server or a phone agent or application based on the processing power available on the phone. The described embodiments were chosen in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The invention relates to the backup and restoration of data stored in a wireless telephone, and in particular a mobile telephone having data storage capabilities. 2. Description of the Related Art Wireless communication devices, such as mobile telephones, have expanded beyond merely mechanisms for communication. Many telephones include features enabling personal productivity, games and even digital cameras. Devices which include personal productivity applications may include data storage for storing the owner's personal information within the storage devices. In addition, phones now have the ability to run application programs specifically designed for phone-based runtime environments. All of an individual's personal information operated on and stored by a user can be considered within that user's “personal information space.” In this context, a “personal information space” is a data store of information customized by, and on behalf of the user which contains both public data the user puts into their personal space, private events in the space, and other data objects such as text files or data files which belong to the user and are manipulated by the user. The personal information space is defined by the content which is specific to and controlled by an individual user, generally entered by or under the control of the individual user, and which includes “public” events and data, those generally known to others, and “private” events and data which are not intended to be shared with others. It should be recognized that each of the aforementioned criteria is not exclusive or required, but defines characteristics of the term “personal information space” as that term is used herein. In this context, such information includes electronic files such as databases, text files, word processing files, and other application specific files, as well as contact information in personal information managers, PDAs and cellular phones. One difficulty users face is that it can be time consuming to enter information into a telephone, and once entered, the information is subject to loss. If the phone is damaged or simply lost by the user, and the time and effort spent to enter the information into the phone is lost. Some phones come with software and data connection cables allowing users to enter and backup information stored on a telephone by physically connecting the telephone to a personal computer. Many of these applications are provided by the manufacturer of the phone and are customized to interact directly with the phone. That is, the application program generally specifically designed for the telephone to retrieve data from the telephone and store it in the application on a personal computer. In addition, some third party vendors have attempted to make more universal synchronization systems that interact with phones through the physical cable. The trouble with these physical connection mechanisms is that the user must consciously remember to physically connect the phone to the computer on a regular basis in order to ensure that the information backed up on the computer is accurate. In addition, the computer itself is subject to volatility. The data on the computer may be lost or damaged due to hardware and software failures. While phone users generally desire increased functionality in phone based applications, they also desire the applications be relatively easy to use. Even general computer based utility applications, such as data back-up applications, are advantageous if they are set to run without significant user intervention. An application which would allow wireless phone users to quickly and easily backup their personal information stored on the telephone would be of great commercial and technical value. | <SOH> SUMMARY OF THE INVENTION <EOH>The invention comprises a system for backing up data on a wireless telephone having a data store containing a user's personal information. A method and application are provided, and various aspects and variations of the system are described herein. The invention provides a convenient means for a user to ensure that information saved on a wireless phone, and the effort spent to ensure that information is entered and correct, are not lost if the phone itself is lost or damaged. The invention, in one aspect, comprises a method for backing up personal information stored in a telephone. In this aspect, the method may include the steps of presenting a back-up system user account set-up interface on the phone; presenting a backup scheduling interface on the phone; and presenting a restore information interface on the phone. In a further aspect, the method may include transmitting phone data to the backup system at user-defined intervals, or upon receipt of an indication from backup store that changes to data on the data store have occurred. The indicator may a result of polling the backup store to determine if changes have occurred. The method may further include the step of providing an interface to the store via the web to alter data in the data store. The method may include further providing a roll-back interface and an undelete interface. In yet another aspect, the invention is a method for storing personal information in a wireless telephone in a backup storage database. In this aspect, the method may comprise the steps of: providing a phone agent including an automated phone data transmission method capable of regularly transmitting changes to a backup store via a communications link and a restore method; and responsive to said agent, providing changes from the backup store to the wireless telephone. In a still further aspect, the invention is a method for maintaining personal information in a wireless telephone. In this aspect, the method includes the steps of establishing a user account, the user account identifying the user by an unique designation; and transmitting phone data to a backup store via a wireless network at regular intervals. In another embodiment, the invention is an application for a wireless telephone. The invention includes an automated backup process transmitting changes to the backup system at user defined intervals. In addition, the application may include a restore process activated by a user to restore information stored on the backup system to the phone. The application may include a rollback phone information process which returns data on the wireless to a state existing on a specified date. The application may further include an undelete record process. The application may include one or more processes running on a server, a BREW agent and/or a JAVA agent or an application designed to operate on a proprietary device or operating system (e.g., a Symbian operating system.) In yet another embodiment, the invention is an application for storing personal information in a wireless telephone having a data store to a backup system. The application includes an automated user account creation method accessing the backup system using a unique identifier for the user to create a user account on the backup system; an automated backup method transmitting changes to the backup system at user defined intervals; and a restore method providing user data to a phone. In another embodiment, the invention comprises one or more processor readable storage devices having processor readable code embodied on said processor readable storage devices, said processor readable code for programming one or more processors to perform a method comprising the steps of: presenting a backup scheduling interface; transmitting an initial set of phone data and changes to the phone data over time to a backup system; and presenting a restore information interface. In a still further aspect, the invention is a backup system using a unique phone identifier in conjunction with personal information stored for a user. In a further aspect, the backup system associates a unique phone identifier with a unique user identifier. In a still further aspect, the phone identifier, the user identifier or both are universally unique. In a further aspect; the invention includes using an existing SyncML client on the phone as the backup client and auto creating the user account info on the server. The present invention can be accomplished using hardware, software, or a combination of both hardware and software. The software used for the present invention is stored on one or more processor readable storage media including hard disk drives, CD-ROMs, DVDs, optical disks, floppy disks, tape drives, RAM, ROM or other suitable storage devices. In alternative embodiments, some or all of the software can be replaced by dedicated hardware including custom integrated circuits, gate arrays, FPGAs, PLDs, and special purpose computers. These and other objects and advantages of the present invention will appear more clearly from the following description in which the preferred embodiment of the invention has been set forth in conjunction with the drawings. | 20040227 | 20090317 | 20050901 | 67912.0 | 4 | RAMPURIA, SHARAD K | WIRELESS TELEPHONE DATA BACKUP SYSTEM | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,789,876 | ACCEPTED | Electric arc welder system with waveform profile control | An electric arc welder for creating a succession of AC waveforms between an electrode and workpiece by a power source comprising an high frequency switching device for creating individual waveforms in the succession of waveforms. Each of the individual waveforms has a profile determined by the magnitude of each of a large number of short current pulses generated at a frequency of at least 18 kHz by a pulse width modulator with the magnitude of the current pulses controlled by a wave shaper. The welder is provided with a profile control network for setting more than one profile parameter selected from the class consisting of frequency, duty cycle, up ramp rate and down ramp rate and a magnitude circuit for adjusting the waveform profile to set total current, voltage and/or power. | 1. An electric arc welder for creating a succession of AC waveforms between an electrode and workpiece by a power source comprising an high frequency switching device for creating individual waveforms in said succession of waveforms, each of said individual waveforms having a profile determined by the magnitude of each of a large number of short current pulses generated at a frequency of at least 18 kHz by a pulse width modulator with the magnitude of said current pulses controlled by a wave shaper and the polarity of any portion of said individual waveforms determined by the data of a polarity signal, a profile control network for establishing the general profile of an individual waveform by setting more than one profile parameter of an individual waveform, said parameters selected from the class consisting of frequency, duty cycle, up ramp rate and down ramp rate and a magnitude circuit for adjusting the individual waveform to set total current, voltage and/or power without substantially affecting the general fixed profile. 2. An electric arc welder as defined in claim 1 wherein said magnitude circuit has a first section for adjusting said individual waveform during the positive polarity of said one waveform and a second section for adjusting said individual waveform during the negative polarity of said AC waveform. 3. An electric arc welder as defined in claim 2 including a device for selecting current, voltage or power in said first section of said magnitude circuit. 4. An electric arc welder as defined in claim 3 including a device for selecting current, voltage or power in said second section of said magnitude circuit. 5. An electric arc welder as defined in claim 2 including a device for selecting current, voltage or power in said second section of said magnitude circuit. 6. An electric arc welder as defined in claim 5 wherein said profile control network sets at least three of said profile parameters. 7. An electric arc welder as defined in claim 4 wherein said profile control network sets at least three of said profile parameters. 8. An electric arc welder as defined in claim 3 wherein said profile control network sets at least three of said profile parameters. 9. An electric arc welder as defined in claim 2 wherein said profile control network sets at least three of said profile parameters. 10. An electric arc welder as defined in claim 1 wherein said profile control network sets at least three of said profile parameters. 11. An electric arc welder as defined in claim 5 wherein said profile control network set all four of said named profile parameters. 12. An electric arc welder as defined in claim 4 wherein said profile control network set all four of said named profile parameters. 13. An electric arc welder as defined in claim 3 wherein said profile control network set all four of said named profile parameters. 14. An electric arc welder as defined in claim 2 wherein said profile control network set all four of said named profile parameters. 15. An electric arc welder as defined in claim 1 wherein said profile control network set all four of said named profile parameters. 16. A method of electric arc welding by creating a succession of AC waveforms between an electrode and workpiece by a power source comprising an high frequency switching device for creating individual waveforms in said succession of waveforms, each of said individual waveforms having a profile determined by the magnitude of each of a large number of short current pulses generated at a frequency of at least 18 kHz by a pulse width modulator with the magnitude of said current pulses controlled by a wave shaper, said method comprising: (a) determining the polarity of any portion of said individual waveforms by the data of a polarity signal; (b) establishing the general profile of an individual waveform by setting more than one profile parameter of an individual waveform, said parameters selected from the class consisting of frequency, duty cycle, up ramp rate and down ramp rate; and, (c) adjusting the waveform profile to set total magnitude of current, voltage and/or power without substantially changing the general profile. 17. A method as defined in claim 16 including the acts of: (d) adjusting the magnitude of said individual waveform during the positive polarity of said AC waveform; and, (e) adjusting the magnitude of said individual waveform during the negative polarity of said AC waveform. 18. A method as defined in claim 17 including the act of: (f) selecting current, voltage or power for magnitude control during said positive polarity. 19. A method as defined in claim 17 including the act of: (g) selecting current, voltage or power for magnitude control during said negative polarity. 20. A method as defined in claim 16 including the act of: (d) adjusting the magnitude of said individual waveform during the positive polarity of said AC waveform. 21. A method as defined in claim 16 including the act of: (d) adjusting the magnitude of said individual waveform during the negative polarity of said AC waveform. 22. An electric arc welder for creating a succession of AC waveforms between an electrode and a workpiece by a power source comprising an high frequency switching device for creating individual waveforms in said succession of waveforms, each of said individual waveforms having a profile determined by the magnitude of each of a large number of short current pulses generated at a frequency of at least 18 kHz by a pulse width modulator with the magnitude of said current pulses controlled by a wave shaper and the polarity of any portion of said individual waveform determined by the data of a polarity signal, and a magnitude circuit for adjusting the individual waveform to a set condition of current, voltage or power. 23. An electric arc welder as defined in claim 22 wherein said magnitude circuit includes an input selector to set said magnitude circuit to a desired polarity. 24. An electric arc welder as defined in claim 23 including a profile control network to control the general profile of said individual waveform. 25. An electric arc welder as defined in claim 24 wherein said profile control network controls more than one profile parameter of an individual waveform profile, said parameters selected from the class consisting of frequency, duty cycle up ramp rate and down ramp rate. 26. An electric arc welder as defined in claim 22 including a profile control network to control the general profile of said individual waveform. 27. An electric arc welder as defined in claim 26 wherein said profile control network controls more than one profile parameter of an individual waveform profile, said parameters selected from the class consisting of frequency, duty cycle up ramp rate and down ramp rate. 28. An electric arc welder for creating a succession of AC waveforms between an electrode and a workpiece by a power source comprising an high frequency switching device for creating individual waveforms in said succession of waveforms, each of said individual waveforms having a profile determined by the magnitude of each of a large number of short current pulses generated at a frequency of at least 18 kHz by a pulse width modulator with the magnitude of said current pulses controlled by a wave shaper and the polarity of any portion of said individual waveform determined by the data of a polarity signal, and a profile control network to control the general profile of said individual waveform. | The present invention relates to the art of electric arc welding and more particularly to an electric arc welder with waveform profile control. INCORPORATION BY REFERENCE The present invention is directed to an electric arc welder system utilizing high capacity alternating circuit power sources for driving two or more tandem electrodes of the type used in seam welding of large metal blanks. It is preferred that the power sources use the switching concept disclosed in Stava U.S. Pat. No. 6,111,216 wherein the power supply is an inverter having two large output polarity switches with the arc current being reduced before the switches reverse the polarity. Consequently, the term “switching point” is a complex procedure whereby the power source is first turned off awaiting a current less than a preselected value, such as 100 amperes. Upon reaching the 100 ampere threshold, the output switches of the power supply are reversed to reverse the polarity from the D.C. output link of the inverter. Thus, the “switching point” is an off output command, known as a “kill” command, to the power supply inverter followed by a switching command to reverse the output polarity. The kill output can be a drop to a decreased current level. This procedure is duplicated at each successive polarity reversal so the AC power source reverses polarity only at a low current. In this manner, snubbing circuits for the output polarity controlling switches are reduced in size or eliminated. Since this switching concept is preferred to define the switching points as used in the present invention, Stava U.S. Pat. No. 6,111,216 is incorporated by reference. The concept of an AC current for tandem electrodes is well known in the art. U.S. Pat. No. 6,207,929 discloses a system whereby tandem electrodes are each powered by a separate inverter type power supply. The frequency is varied to reduce the interference between alternating current in the adjacent tandem electrodes. Indeed, this prior patent of assignee relates to single power sources for driving either a DC powered electrode followed by an AC electrode or two or more AC driven electrodes. In each instance, a separate inverter type power supply is used for each electrode and, in the alternating current high capacity power supplies, the switching point concept of Stava U.S. Pat. No. 6,111,216 is employed. This system for separately driving each of the tandem electrodes by a separate high capacity power supply is background information to the present invention and is incorporated herein as such background. In a like manner, U.S. Pat. No. 6,291,798 discloses a further arc welding system wherein each electrode in a tandem welding operation is driven by two or more independent power supplies connected in parallel with a single electrode arc. The system involves a single set of switches having two or more accurately balanced power supplies forming the input to the polarity reversing switch network operated in accordance with Stava U.S. Pat. No. 6,111,216. Each of the power supplies is driven by a single command signal and, therefore, shares the identical current value combined and directed through the polarity reversing switches. This type system requires large polarity reversing switches since all of the current to the electrode is passed through a single set of switches. U.S. Pat. No. 6,291,798 does show a master and slave combination of power supplies for a single electrode and discloses general background information to which the invention is directed. For that reason, this patent is also incorporated by reference. An improvement for operating tandem electrodes with controlled switching points is disclosed in Houston U.S. Pat. No. 6,472,634. This patent is incorporated by reference. BACKGROUND OF INVENTION Welding applications, such as pipe welding, often require high currents and use several arcs created by tandem electrodes. Such welding systems are quite prone to certain inconsistencies caused by arc disturbances due to magnetic interaction between two adjacent tandem electrodes. A system for correcting the disadvantages caused by adjacent AC driven tandem electrodes is disclosed in Stava U.S. Pat. No. 6,207,929. In that prior patent, each of the AC driven electrodes has its own inverter based power supply. The output frequency of each power supply is varied so as to prevent interference between adjacent electrodes. This system requires a separate power supply for each electrode. As the current demand for a given electrode exceeds the current rating of the inverter based power supply, a new power supply must be designed, engineered and manufactured. Thus, such system for operating tandem welding electrodes require high capacity or high rated power supplies to obtain high current as required for pipe welding. To decrease the need for special high current rated power supplies for tandem operated electrodes, assignee developed the system disclosed in Stava U.S. Pat. No. 6,291,798 wherein each AC electrode is driven by two or more inverter power supplies connected in parallel. These parallel power supplies have their output current combined at the input side of a polarity switching network. Thus, as higher currents are required for a given electrode, two or more parallel power supplies are used. In this system, each of the power supplies are operated in unison and share equally the output current. Thus, the current required by changes in the welding conditions can be provided only by the over current rating of a single unit. A current balanced system did allow for the combination of several smaller power supplies; however, the power supplies had to be connected in parallel on the input side of the polarity reversing switching network. As such, large switches were required for each electrode. Consequently, such system overcame the disadvantage of requiring special power supplies for each electrode in a tandem welding operation of the type used in pipe welding; but, there is still the disadvantage that the switches must be quite large and the input, paralleled power supplies must be accurately matched by being driven from a single current command signal. Stava U.S. Pat. No. 6,291,798 does utilize the concept of a synchronizing signal for each welding cell directing current to each tandem electrode. However, the system still required large switches. This type of system was available for operation in an ethernet network interconnecting the welding cells. In ethernet interconnections, the timing cannot be accurately controlled. In the system described, the switch timing for a given electrode need only be shifted on a time basis, but need not be accurately identified for a specific time. Thus, the described system requiring balancing the current and a single switch network has been the manner of obtaining high capacity current for use in tandem arc welding operations when using an ethernet network or an internet and ethernet control system. There is a desire to control welders by an ethernet network, with or without an internet link. Due to timing limitation, these networks dictated use of tandem electrode systems of the type using only general synchronizing techniques. Such systems could be controlled by a network; however, the parameter to each paralleled power supply could not be varied. Each of the cells could only be offset from each other by a synchronizing signal. Such systems were not suitable for central control by the internet and/or local area network control because an elaborate network to merely provide offset between cells was not advantageous. Houston U.S. Pat. No. 6,472,634 discloses the concept of a single AC arc welding cell for each electrode wherein the cell itself includes one or more paralleled power supplies each of which has its own switching network. The output of the switching network is then combined to drive the electrode. This allows the use of relatively small switches for polarity reversing of the individual power supplies paralleled in the system. In addition, relatively small power supplies can be paralleled to build a high current input to each of several electrodes used in a tandem welding operation. The use of several independently controlled power supplies paralleled after the polarity switch network for driving a single electrode allows advantageous use of a network, such as the internet or ethernet. In Houston U.S. Pat. No. 6,472,634, smaller power supplies in each system are connected in parallel to power a single electrode. By coordinating switching points of each paralleled power supply with a high accuracy interface, the AC output current is the sum of currents from the paralleled power supplies without combination before the polarity switches. By using this concept, the ethernet network, with or without an internet link, can control the weld parameters of each paralleled power supply of the welding system. The timing of the switch points is accurately controlled by the novel interface, whereas the weld parameters directed to the controller for each power supply can be provided by an ethernet network which has no accurate time basis. Thus, an internet link can be used to direct parameters to the individual power supply controllers of the welding system for driving a single electrode. There is no need for a time based accuracy of these weld parameters coded for each power supply. In the preferred implementation, the switch point is a “kill” command awaiting detection of a current drop below a minimum threshold, such as 100 amperes. When each power supply has a switch command, then they switch. The switch points between parallel power supplies, whether instantaneous or a sequence involving a “kill” command with a wait delay, are coordinated accurately by an interface card having an accuracy of less than 10 μs and preferably in the range of 1-5 μs. This timing accuracy coordinates and matches the switching operation in the paralleled power supplies to coordinate the AC output current. By using the internet or ethernet local area network, the set of weld parameters for each power supply is available on a less accurate information network, to which the controllers for the paralleled power supplies are interconnected with a high accuracy digital interface card. Thus, the switching of the individual, paralleled power supplies of the system is coordinated. This is an advantage allowing use of the internet and local area network control of a welding system. The information network includes synchronizing signals for initiating several arc welding systems connected to several electrodes in a tandem welding operation in a selected phase relationship. Each of the welding systems of an electrode has individual switch points accurately controlled while the systems are shifted or delayed to prevent magnetic interference between different electrodes. This allows driving of several AC electrodes using a common information network. The Houston U.S. Pat. No. 6,472,634 system is especially useful for paralleled power supplies to power a given electrode with AC current. The switch points are coordinated by an accurate interface and the weld parameter for each paralleled power supply is provided by the general information network. This background is technology developed and patented by assignee and does not necessarily constitute prior art just because it is herein used as “background.” As a feature of the system in Stava U.S. Pat. No. 6,207,929, two or more power supplies can drive a single electrode. Thus, the system comprises a first controller for a first power supply to cause the first power supply to create an AC current between the electrode and workpiece by generating a switch signal with polarity reversing switching points in general timed relationship with respect to a given system synchronizing signal received by the first controller. This first controller is operated at first welding parameters in response to a set of first power supply specific parameter signals directed to the first controller. There is provided at least one slave controller for operating the slave power supply to create an AC current between the same electrode and workpiece by reversing polarity of the AC current at switching points. The slave controller operates at second weld parameters in response to the second set of power supply specific parameter signals to the slave controller. An information network connected to the first controller and the second or slave controller contains digital first and second power supply specific parameter signals for the two controllers and the system specific synchronizing signal. Thus, the controllers receive the parameter signals and the synchronizing signal from the information network, which may be an ethernet network with or without an internet link, or merely a local area network. The invention involves a digital interface connecting the first controller and the slave controller to control the switching points of the second or slave power supply by the switch signal from the first or master controller. In practice, the first controller starts a current reversal at a switch point. This event is transmitted at high accuracy to the slave controller to start its current reversal process. When each controller senses an arc current less than a given number, a “ready signal” is created. After a “ready” signal from all paralleled power supplies, all power supplies reverse polarity. This occurs upon receipt of a strobe or look command each 25 μs. Thus, the switching is in unison and has a delay of less than 25 μs. Consequently, both of the controllers have interconnected data controlling the switching points of the AC current to the single electrode. The same controllers receive parameter information and a synchronizing signal from an information network which in practice comprises a combination of internet and ethernet or a local area ethernet network. The timing accuracy of the digital interface is less than about 10 μs and, preferably, in the general range of 1-5 μs. Thus, the switching points for the two controllers driving a single electrode are commanded within less than 5 μs. Then, switching actually occurs within 25 μs. At the same time, relatively less time sensitive information is received from the information network also connected to the two controllers driving the AC current to a single electrode in a tandem welding operation. The 25 μs maximum delay can be changed, but is less than the switch command accuracy. The unique control system disclosed in Houston U.S. Pat. No. 6,472,634 is used to control the power supply for tandem electrodes used primarily in pipe seam welding and disclosed in Stava U.S. Pat. No. 6,291,798. This Stava patent relates to a series of tandem electrodes movable along a welding path to lay successive welding beads in the space between the edges of a rolled pipe or the ends of two adjacent pipe sections. The individual AC waveforms used in this unique technology are created by a number of current pulses occurring at a frequency of at least 18 kHz with a magnitude of each current pulse controlled by a wave shaper. This technology dates back to Blankenship U.S. Pat. No. 5,278,390. Shaping of the waveforms in the AC currents of two adjacent tandem electrodes is known and is shown in not only the patents mentioned above, but in Stava U.S. Pat. No. 6,207,929. In this latter Stava patent, the frequency of the AC current at adjacent tandem electrodes is adjusted to prevent magnetic interference. All of these patented technologies by The Lincoln Electric Company of Cleveland, Ohio have been advances in the operation of tandem electrodes each of which is operated by a separate AC waveform created by the waveform technology set forth in these patents. These patents are incorporated by reference herein. However, these patents do not disclose the present invention which is directed to the use of such waveform technology for use in tandem welding by adjacent electrodes each using an AC current. This technology, as the normal transformer technology, has experienced difficulty in controlling the dynamics of the weld puddle. Thus, there is a need for an electric arc welding system for adjacent tandem electrodes which is specifically designed to control the dynamics and physics of the molten weld puddle during the welding operation. These advantages can not be obtained by merely changing the frequency to reduce the magnetic interference. THE INVENTION The present invention relates to an improvement in the waveform technology disclosed in Blankenship U.S. Pat. No. 5,278,390 and used for tandem electrode welding systems by several patents, including Stava U.S. Pat. No. 6,207,929; Stava U.S. Pat. No. 6,291,798; and, Houston U.S. Pat. No. 6,472,634. The improvement over this well developed technology is to control on a real time basis the individual AC waveforms generated between the electrode and workpiece which waveforms in succession constitute the welding process. By using the present invention each individual waveform in the AC welding process is controlled in a unique manner that adjusts several profile parameters and also the energy profile of the individual sections of the waveform. In this manner, various welding currents and/or voltage waveforms can be used to effect the overall welding process in a unique manner that accurately controls the process using waveform technology of the type pioneered by The Lincoln Electric Company of Cleveland, Ohio. By using the present invention, the welding process can be controlled to effect several characteristics such as penetration into the base metal, the melt off rate of the electrode, the heat input into the base metal, and the welding travel speed as well as the wire feed speed. In addition, various arc welding current and/or arc welding voltage waveforms can be generated to essentially “paint” a desired waveform to effect the mechanical and metallurgical properties of the “as welded” weld metal resulting from the welding process. The invention controls the general profile of a waveform which means the parameters defining the profile are controlled. Then the energy or power of the profile controlled waveform can be adjusted without changing the general profile which is fixed. When combining various welding waveforms, sometimes called wave shapes, with specific electrodes, an improvement in the welding process both in welding speed and improved mechanical metallurgical properties is obtained. The types of electrode that are combined with the unique profile controlled waveforms are solid wires normally used for low carbon steel, solid wires of various alloys such as, but not limited to, nickel and chrome for welding stainless steel and other similar alloys, aluminum electrodes and cored electrodes including internal flux and metal alloys. By selecting the desired welding wire and then using the present invention to “paint” the exactly controlled general profile of an individual waveform in a succession of waveforms constituting the welding process, the welder using the present invention can produce heretofore unobtainable weld results. In the past, the ability to use SCR welders to produce AC waveforms of accurately and varied shapes is technically difficult, if not impossible. The present invention utilizes the high frequency waveform technology using an inverter or an equivalent chopper and/or design, which designs have the capacity of generating virtually any waveform profile. The waveform profile of successive waveforms in an AC welding process usually involves producing current pulses at a rate exceeding 18 kHz to enable the generation of a waveform by adding or subtracting small amounts of energy. The present invention uses this technology by controlling the general profile of individual waveforms. The invention produces an AC waveform with a controlled profile, whereas normally such technology was used to produce DC or pulse DC waveforms. When the technology was used before to create AC waveforms, the waveforms were fixed and normally square wave. Such square waves were normally not imbalanced AC waveforms because the control concept was not directed to profile parameters, but to pulse wave magnitude. The present invention provides an improvement to a welder using high switching speed waveform technology which improvement allows the individual waveforms to be created in virtually any desired profile by controlling a set of profile parameters. In this manner, the exact general profile of a waveform can be combined with the precise welding electrode or wire to produce the desired welding characteristics of a welding process, particularly an automatic weld process such as implemented by a robotic cell. The profile is combined with a magnitude circuit to change magnitude to adjust heat while holding the exact set general profile. In accordance with the present invention there is provided an electric arc welder for creating a succession of AC waveforms between an electrode and a workpiece by a power source comprising an high frequency switching device such as an inverter or its equivalent chopper for creating individual waveforms in the succession of waveforms constituting the welding process. Each of the individual waveforms has a precise general profile determined by the magnitude of each of a large number of short current pulses generated at a frequency of at least 18 kHz by a pulse width modulator with the magnitude of the current pulses controlled by a wave shaper. The polarity of any portion of the individual AC waveform is determined by the data of a polarity signal. A profile control network is used for establishing the general profile of an individual waveform by setting more than one profile parameter of the individual waveform. The parameters are selected from the class consisting of frequency, duty cycle, up ramp rate and down ramp rate. Also included in the welder control is a magnitude circuit for adjusting the individual waveform profile to set total current, voltage and/or power for the waveform without substantially changing the set general profile. This concept of the invention is normally accomplished in two sections where the energy is controlled in the positive polarity and in the negative polarity of the generated waveform profile. In accordance with another aspect of the present invention there is provided a method of electric arc welding by creating a succession of AC waveforms between an electrode and a workpiece by a power source comprising an high frequency switching device for creating individual waveforms in the succession of waveforms constituting the weld process. Each of the individual waveforms has profile determined by the magnitude of each of a large number of short current pulses generated at a frequency of at least 18 kHz by a pulse width modulator with the magnitude of the current pulses controlled by a wave shaper. The method comprises determining the plurality of any portion of the individual waveform by the data of a plurality signal, establishing the general profile of an individual waveform by setting more than one profile parameter of an individual waveform, said parameters selected from the class consisting of frequency, duty cycle, up ramp rate and down ramp rate and adjusting the waveform to set the total magnitude of current, voltage and/or power without substantially changing the set profile. The primary object of the present invention is the provision of an electric arc welder using waveform technology wherein the general profile of the individual waveforms constituting the AC welding process is accurately controlled to a given profile that will precisely perform a welding process with desired physical and metallurgical characteristics. Another object of the present invention is the provision of an electric arc welder, as defined above, which electric arc welder generates a precise controllable and changeable general profile for the waveform of an AC welding process to thereby adjust the weld speed, deposition rate, heat input, mechanical and metallurgical properties and related characteristics to improve the quality and performance of the welding process. Yet another object of the present invention is the provision of an electric arc welder, as defined above, which electric arc welder simultaneously adjusts more than one profile parameter of an individual waveform where the parameters are selected from the class consisting of frequency, duty cycle, up ramp rate and down ramp rate. Still a further object of the present invention is the provision of an electric arc welder, as defined above, which electric arc welder includes a magnitude circuit control for adjusting the individual waveform profile to set total current voltage and/or power for each of the polarity portions of the waveform constituting the AC welding process without substantially changing the set waveform profile. Yet another object of the present invention is the provision of a method for arc welding that creates a succession of AC waveforms between an electrode and workpiece, which method accurately and interactively sets the general profile of the individual waveform constituting the AC welding process. These and other objects and advantages will become apparent from the following description taken together with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a block diagram of a welding system that can be used to perform the present invention; FIG. 2 is a wiring diagram of two paralleled power sources, each of which include a switching output and can be used in practicing the invention; FIG. 3 is a cross sectional side view of three tandem electrodes of the type controllable by the power source disclosed in FIGS. 1 and 2; FIG. 4 is a schematic layout in block form of a welding system for three electrodes using the disclosure in Houston U.S. Pat. No. 6,472,634 and Stava U.S. Pat. No. 6,291,798 and where one of the three power sources is used in practicing the invntion as shown in FIGS. 17 and 18; FIG. 5 is a block diagram showing a single electrode driven by the system as shown in FIG. 4 with a variable pulse generator disclosed in Houston U.S. Pat. No. 6,472,634 and used for practicing the present invention; FIG. 6 is a current graph for one of two illustrated synchronizing pulses and showing a balanced AC waveform for one tandem electrode; FIG. 7 is a current graph superimposed upon a polarity signal having logic to determine the polarity of the waveform as used in a welder that can practice the present invention; FIG. 8 is a current graph showing a broad aspect of a waveform with a profile controllable by the present invention; FIGS. 9 and 10 are schematic drawings illustrating the dynamics of the weld puddle during concurrent polarity relationships of tandem electrodes; FIG. 11 is a pair of current graphs showing the waveforms on two adjacent tandem electrodes that can be generated by a background system; FIG. 12 is a pair of current graphs of the AC waveforms on adjacent tandem electrodes with areas of concurring polarity relationships; FIG. 13 are current graphs of the waveforms on adjacent tandem electrodes wherein the AC waveform of one electrode is substantially different waveform of the other electrode to limit the time of concurrent polarity relationships; FIG. 14 are current graphs of two sinusoidal waveforms for adjacent electrodes operated by a background system to use different shaped wave forms for the adjacent electrodes; FIG. 15 are current graphs showing waveforms at four adjacent AC arcs of tandem electrodes shaped and synchronized in accordance with a background aspect of the invention; FIG. 16 is a schematic layout of a known software program to cause switching of the paralleled power supplies as soon as the coordinated switch commands have been processed and the next coincident signal has been created; FIG. 17 is a block diagram of the program used in the computer controller to improve the background system shown in FIGS. 1-16 so a welder performs in accordance with the preferred embodiment of the present invention; and, FIG. 18 is a schematically illustrated waveform used in explaining the implementation of the present invention. PREFERRED EMBODIMENT Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only and not for the purpose of limiting same, a background system for implementing the invention is shown in detail in FIGS. 1, 2, 4, 5 and 16. FIGS. 2 and 6-15 describe prior attributes of the disclosed background welding systems. The improvement of this invention is shown in FIGS. 17 and 18. Turning now to the background system to which the present invention is an improvement and/or an enhancement, FIG. 1 discloses a single electric arc welding system S in the form of a single cell to create an alternating current as an arc at weld station WS. This system or cell includes a first master welder A with output leads 10, 12 in series with electrode E and workpiece W in the form of a pipe seam joint or other welding operation. Hall effect current transducer 14 provides a voltage in line 16 proportional to the current of welder A. Less time critical data, such as welding parameters, are generated at a remote central control 18. In a like manner, a slave following welder B includes leads 20, 22 connected in parallel with leads 10, 12 to direct an additional AC current to the weld station WS. Hall effect current transducer 24 creates a voltage in line 26 representing current levels in welder B during the welding operation. Even though a single slave or follower welder B is shown, any number of additional welders can be connected in parallel with master welder A to produce an alternating current across electrode E and workpiece W. The AC current is combined at the weld station instead of prior to a polarity switching network. Each welder includes a controller and inverter based power supply illustrated as a combined master controller and power supply 30 and a slave controller and power supply 32. Controllers 30, 32 receive parameter data and synchronization data from a relatively low level logic network. The parameter information or data is power supply specific whereby each of the power supplies is provided with the desired parameters such as current, voltage and/or wire feed speed. A low level digital network can provide the parameter information; however, the AC current for polarity reversal occurs at the same time. The “same” time indicates a time difference of less than 10 μs and preferably in the general range of 1-5 μs. To accomplish precise coordination of the AC output from power supply 30 and power supply 32, the switching points and polarity information can not be provided from a general logic network wherein the timing is less precise. The individual AC power supplies are coordinated by high speed, highly accurate DC logic interface referred to as “gateways.” As shown in FIG. 1, power supplies 30, 32 are provided with the necessary operating parameters indicated by the bi-directional leads 42m, 42s, respectively. This non-time sensitive information is provided by a digital network shown in FIG. 1. Master power supply 30 receives a synchronizing signal as indicated by unidirectional line 40 to time the controllers operation of its AC output current. The polarity of the AC current for power supply 30 is outputted as indicated by line 46. The actual switching command for the AC current of master power supply 30 is outputted on line 44. The switch command tells power supply S, in the form of an inverter, to “kill,” which is a drastic reduction of current. In an alternative, this is actually a switch signal to reverse polarity. The “switching points” or command on line 44 preferably is a “kill” and current reversal commands utilizing the “switching points” as set forth in Stava U.S. Pat. No. 6,111,216. Thus, timed switching points or commands are outputted from power supply 30 by line 44. These switching points or commands may involve a power supply “kill” followed by a switch ready signal at a low current or merely a current reversal point. The switch “ready” is used when the “kill” concept is implemented because neither inverters are to actually reverse until they are below the set current. This is described in FIG. 16. The polarity of the switches of controller 30 controls the logic on line 46. Slave power supply 32 receives the switching point or command logic on line 44b and the polarity logic on line 46b. These two logic signals are interconnected between the master power supply and the slave power supply through the highly accurate logic interface shown as gateway 50, the transmitting gateway, and gateway 52, the receiving gateway. These gateways are network interface cards for each of the power supplies so that the logic on lines 44b, 46b are timed closely to the logic on lines 44, 46, respectively. In practice, network interface cards or gateways 50, 52 control this logic to within 10 μs and preferably within 1-5 μs. A low accuracy network controls the individual power supplies for data from central control 18 through lines 42m, 42s, illustrated as provided by the gateways or interface cards. These lines contain data from remote areas (such as central control 18) which are not time sensitive and do not use the accuracy characteristics of the gateways. The highly accurate data for timing the switch reversal uses interconnecting logic signals through network interface cards 50, 52. The system in FIG. 1 is a single cell for a single AC arc; however, the invention is not limited to tandem electrodes wherein two or more AC arcs are created to fill the large gap found in pipe welding. However, the background system is shown for this application. Thus, the master power supply 30 for the first electrode receives a synchronization signal which determines the timing or phase operation of the system S for a first electrode, i.e. ARC 1. System S is used with other identical systems to generate ARCs 2, 3, and 4 timed by synchronizing outputs 84, 86 and 88. This concept is schematically illustrated in FIG. 5. The synchronizing or phase setting signals 82-88 are shown in FIG. 1 with only one of the tandem electrodes. An information network N comprising a central control computer and/or web server 60 provides digital information or data relating to specific power supplies in several systems or cells controlling different electrodes in a tandem operation. Internet information is directed to a local area network in the form of an ethernet network 70 having local interconnecting lines 70a, 70b, 70c. Similar interconnecting lines are directed to each power supply used in the four cells creating ARCs 1, 2, 3 and 4 of a tandem welding operation. The description of system or cell S applies to each of the arcs at the other electrodes. If AC current is employed, a master power supply is used. In some instances, merely a master power supply is used with a cell specific synchronizing signal. If higher currents are required, the systems or cells include a master and slave power supply combination as described with respect to system S of FIG. 1. In some instances, a DC arc is used with two or more AC arcs synchronized by generator 80. Often the DC arc is the leading electrode in a tandem electrode welding operation, followed by two or more synchronized AC arcs. A DC power supply need not be synchronized, nor is there a need for accurate interconnection of the polarity logic and switching points or commands. Some DC powered electrodes maybe switched between positive and negative, but not at the frequency of an AC driven electrode. Irrespective of the make-up of the arcs, ethernet or local area network 70 includes the parameter information identified in a coded fashion designated for specific power supplies of the various systems used in the tandem welding operation. This network also employs synchronizing signals for the several cells or systems whereby the systems can be offset in a time relationship. These synchronizing signals are decoded and received by a master power supply as indicated by line 40 in FIG. 1. In this manner, the AC arcs are offset on a time basis. These synchronizing signals are not required to be as accurate as the switching points through network interface cards or gateways 50, 52. Synchronizing signals on the data network are received by a network interface in the form of a variable pulse generator 80. The generator creates offset synchronizing signals in lines 84, 86 and 88. These synchronizing signals dictate the phase of the individual alternating current cells for separate electrodes in the tandem operation. Synchronizing signals can be generated by interface 80 or actually received by the generator through the network 70. Network 70 merely activates generator 80 to create the delay pattern for the many synchronizing signals. Also, generator 80 can vary the frequency of the individual cells by frequency of the synchronizing pulses if that feature is desired in the tandem welding operation. A variety of controllers and power supplies could be used for practicing the system as described in FIG. 1; however, preferred implementation of the system is set forth in FIG. 2 wherein power supply PSA is combined with controller and power supply 30 and power supply PSB is combined with controller and power supply 32. These two units are essentially the same in structure and are labeled with the same numbers when appropriate. Description of power supply PSA applies equally to power supply PSB. Inverter 100 has an input rectifier 102 for receiving three phase line current L1, L2, and L3. Output transformer 110 is connected through an output rectifier 112 to tapped inductor 120 for driving opposite polarity switches Q1, Q2. Controller 140a of power supply PSA and controller 140b of PSB are essentially the same, except controller 140a outputs timing information to controller 140b. Switching points or lines 142, 144 control the conductive condition of polarity switches Q1, Q2 for reversing polarity at the time indicated by the logic on lines 142, 144, as explained in more detail in Stava U.S. Pat. No. 6,111,216 incorporated by reference herein. The control is digital with a logic processor; thus, A/D converter 150 converts the current information on feedback line 16 or line 26 to controlling digital values for the level of output from error amplifier 152 which is illustrated as an analog error amplifier. In practice, this is a digital system and there is no further analog signal in the control architecture. As illustrated, however, amplifier has a first input 152a from converter 150 and a second input 152b from controller 140a or 140b. The current command signal on line 152b includes the wave shape or waveform required for the AC current across the arc at weld station WS. This is standard practice as taught by several patents of Lincoln Electric, such as Blankenship U.S. Pat. No. 5,278,390, incorporated by reference. See also Stava U.S. Pat. No. 6,207,929, incorporated by reference. The output from amplifier 152 is converted to an analog voltage signal by converter 160 to drive pulse width modulator 162 at a frequency controlled by oscillator 164, which is a timer program in the processor software. The shape of the waveform at the arcs is the voltage or digital number at lines 152b. The frequency of oscillator 164 is greater than 18 kHz. The total architecture of this system is digitized in the preferred embodiment of the present invention and does not include reconversion back into analog signal. This representation is schematic for illustrative purposes and is not intended to be limiting of the type of power supply used in practicing the present invention. Other power supplies could be employed. A background system utilizing the concepts of FIGS. 1 and 2 are illustrated in FIGS. 3 and 4. Workpiece 200 is a seam in a pipe which is welded together by tandem electrodes 202, 204 and 206 powered by individual power supplies PS1, PS2, PS3, respectively. The power supplies can include more than one power source coordinated in accordance with the technology in Houston U.S. Pat. No. 6,472,634. The illustrated embodiment involves a DC arc for lead electrode 202 and an AC arc for each of the tandem electrodes 204, 206. The created waveforms of the tandem electrodes are AC currents and include shapes created by a wave shaper or wave generator in accordance with the previously described waveform technology. As electrodes 202, 204 and 206 are moved along weld path WP a molten metal puddle P is deposited in pipe seam 200 with an open root portion 210 followed by deposits 212, 214 and 216 from electrodes 202, 204 and 206, respectively. As previously described more than two AC driven electrodes as will be described and illustrated by the waveforms of FIG. 15, can be operated by the invention relating to AC currents of adjacent electrodes. The power supplies, as shown in FIG. 4, each include an inverter 220 receiving a DC link from rectifier 222. In accordance with Lincoln waveform technology, a chip or internal programmed pulse width modulator stage 224 is driven by an oscillator 226 at a frequency greater than 18 kHz and preferably greater than 20 kHz. As oscillator 226 drives pulse width modulator 224, the output current has a shape dictated by the wave shape outputted from wave shaper 240 as a voltage or digital numbers at line 242. The shape in real time is compared with the actual arc current in line 232 by a stage illustrated as comparator 230 so that the outputs on line 234 controls the shape of the AC waveforms. The digital number or voltage on line 234 determines the output signal on line 224a to control inverter 220 so that the waveform of the current at the arc follows the selected profile outputted from wave shaper 240. This is standard Lincoln waveform technology, as previously discussed. Power supply PS1 creates a DC arc at lead electrode 202; therefore, the output from wave shaper 240 of this power supply is a steady state indicating the magnitude of the DC current. The present invention does not relate to the formation of a DC arc. To the contrary, the present invention is the control of the current at two adjacent AC arcs for tandem electrodes, such as electrodes 204, 206. In accordance with the invention, wave shaper 240 involves an input 250 employed to select the desired shape or profile of the AC waveform. This shape can be shifted in real time by an internal programming schematically represented as shift program 252. Wave shaper 240 has an output which is a priority signal on line 254. In practice, the priority signal is a bit of logic, as shown in FIG. 7. Logic 1 indicates a negative polarity for the waveform generated by wave shaper 240 and logic 0 indicates a positive polarity. This logic signal or bit controller 220 directed to the power supply is read in accordance with the technology discussed in FIG. 16. The inverter switches from a positive polarity to a negative polarity, or the reverse, at a specific “READY” time initiated by a change of the logic bit on line 254. In practice, this bit is received from variable pulse generator 80 shown in FIG. 1 and in FIG. 5. The background welding system shown in FIGS. 3 and 4 uses the shapes of AC arc currents at electrodes 204 and 206 to obtain a beneficial result, i.e. a generally quiescent molten metal puddle P and/or synthesized sinusoidal waveforms compatible with transformer waveforms used in arc welding. The electric arc welding system shown in FIGS. 3 and 4 have a program to select the waveform at “SELECT” program 250 for wave shaper 240. The unique waveforms are used by the tandem electrodes. One of the power supplies to create an AC arc is schematically illustrated in FIG. 5. The power supply or source is controlled by variable pulse generator 80, shown in FIG. 1. Signal 260 from the generator controls the power supply for the first arc. This signal includes the synchronization of the waveform together with the polarity bit outputted by the wave shaper 240 on line 254. Lines 260a-260n control the desired subsequent tandem AC arcs operated by the welding system of the present invention. The timing of these signals shifts the start of the other waveforms. FIG. 5 merely shows the relationship of variable pulse generator 80 to control the successive arcs as explained in connection with FIG. 4. In the welding system of Houston U.S. Pat. No. 6,472,634, the AC waveforms are created as shown in FIG. 6 wherein the wave shaper for arc AC1 at electrode 204 creates a signal 270 having positive portions 272 and negative portions 274. The second arc AC2 at electrode 206 is controlled by signal 280 from the wave shaper having positive portions 282 and negative portions 284. These two signals are the same, but are shifted by the signal from generator 80 a distance x, as shown in FIG. 6. The waveform technology created current pulses or waveforms at one of the arcs are waveforms having positive portions 290 and negative portions 292 shown at the bottom portion of FIG. 6. A logic bit from the wave shaper determines when the waveform is switched from the positive polarity to the negative polarity and the reverse. In accordance with the disclosure in Stava U.S. Pat. No. 6,111,216 (incorporated by reference herein) pulse width modulator 224 is generally shifted to a lower level at point 291a and 291b. Then the current reduces until reaching a fixed level, such as 100 amps. Consequently, the switches change polarity at points 294a and 294b. This produces a vertical line or shape 296a, 296b when current transitioning between positive portion 290 and negative portion 292. This is the system disclosed in the Houston patent where the like waveforms are shifted to avoid magnetic interference. The waveform portions 290, 292 are the same at arc AC1 and at arc AC2. This is different from the present invention which relates to customizing the waveforms at arc AC1 and arc AC2 for purposes of controlling the molten metal puddle and/or synthesizing a sinusoidal wave shape in a manner not heretofore employed. The disclosure of FIG. 6 is set forth to show the concept of shifting the waveforms. The same switching procedure to create a vertical transition between polarities is used in the preferred embodiment of the present invention. Converting from the welding system shown in FIG. 6 to an imbalance waveformis generally shown in FIG. 7. The logic on line 254 is illustrated as being a logic 1 in portions 300 and a logic 0 in portions 302. The change of the logic or bit numbers signals the time when the system illustrated in FIG. 16 shifts polarity. This is schematically illustrated in the lower graph of FIG. 6 at points 294a, 294b. Wave shaper 240 for each of the adjacent AC arcs has a first wave shape 310 for one of the polarities and a second wave shape 312 for the other polarity. Each of the waveforms 310, 312 are created by the logic on line 234 taken together with the logic on line 254. Thus, pulses 310, 312 as shown in FIG. 7, are different pulses for the positive and negative polarity portions. Each of the pulses 310, 312 are created by separate and distinct current pulses 310a, 312a as shown. Switching between polarities is accomplished as illustrated in FIG. 6 where the waveforms generated by the wave shaper are shown as having the general shape of waveforms 310, 312. Positive polarity controls penetration and negative polarity controls deposition. The positive and negative pulses of a waveform are different and the switching points are controlled so that the AC waveform at one arc is controlled both in the negative polarity and the positive polarity to have a specific shape created by the output of wave shaper 240. The waveforms for the arc adjacent to the arc having the current shown in FIG. 7 is controlled differently to obtain the advantages illustrated best in FIG. 8. The waveform at arc AC 1 is in the top part of FIG. 8. It has positive portions 320 shown by current pulses 320a and negative portions 322 formed by pulses 322a. Positive portion 320 has a maximum magnitude a and width or time period b. Negative portion 322 has a maximum magnitude d and a time or period c. These four parameters are adjusted by wave shaper 240. In the illustrated embodiment, arc AC2 has the waveform shown at the bottom of FIG. 8 where positive portion 330 is formed by current pulses 330a and has a height or magnitude a′ and a time length or period b′. Negative portion 332 is formed by pulses 332a and has a maximum amplitude b′ and a time length c′. These parameters are adjusted by wave shaper 240. In accordance with the invention, the waveform from the wave shaper on arc AC1 is out of phase with the wave shape for arc AC2. The two waveforms have parameters or dimensions which are adjusted so that (a) penetration and deposition is controlled and (b) there is no long time during which the puddle P is subjected to a specific polarity relationship, be it a like polarity or opposite polarity. This concept in formulating the wave shapes prevents long term polarity relationships as explained by the showings in FIGS. 9 and 10. In FIG. 9 electrodes 204, 206 have like polarity, determined by the waveforms of the adjacent currents at any given time. At that instance, magnetic flux 350 of electrode 204 and magnetic flux 352 of electrode 206 are in the same direction and cancel each other at center area 354 between the electrodes. This causes the molten metal portions 360, 362 from electrodes 204, 206 in the molten puddle P to move together, as represented by arrows c. This inward movement together or collapse of the molten metal in puddle P between electrodes 204 will ultimately cause an upward gushing action, if not terminated in a very short time, i.e. less than about 20 ms. As shown in FIG. 10, the opposite movement of the puddle occurs when the electrodes 204, 206 have opposite polarities. Then, magnetic flux 370 and magnetic flux 372 are accumulated and increased in center portion 374 between the electrodes. High forces between the electrodes causes the molten metal portions 364, 366 of puddle P to retract or be forced away from each other. This is indicated by arrows r. Such outward forcing of the molten metal in puddle P causes disruption of the weld bead if it continues for a substantial time which is generally less than 10 ms. As can be seen from FIGS. 9 and 10, it is desirable to limit the time during which the polarity of the waveform at adjacent electrodes is either the same polarity or opposite polarity. The waveform, such as shown in FIG. 6, accomplishes the objective of preventing long term concurrence of specific polarity relationships, be it like polarities or opposite polarities. As shown in FIG. 8, like polarity and opposite polarity is retained for a very short time less than the cycle length of the waveforms at arc AC1 and arc AC2. This positive development of preventing long term occurrence of polarity relationships together with the novel concept of pulses having different shapes and different proportions in the positive and negative areas combine to control the puddle, control penetration and control deposition in a manner not heretofore obtainable in welding with a normal transformer power supplies or normal use of Lincoln waveform technology. In FIG. 11 the positive and negative portions of the AC waveform from the wave shaper 240 are synthesized sinusoidal shapes with a different energy in the positive portion as compared to the negative portion of the waveforms. The synthesized sine wave or sinusoidal portions of the waveforms allows the waveforms to be compatible with transformer welding circuits and compatible with evaluation of sine wave welding. In FIG. 11, waveform 370 is at arc AC1 and waveform 372 is at arc AC2. These tandem arcs utilize the AC welding current shown in FIG. 11 wherein a small positive sinusoidal portion 370a controls penetration at arc AC1 while the larger negative portion 370b controls the deposition of metal at arc AC1. There is a switching between the polarities with a change in the logic bit, as discussed in FIG. 7. Sinusoidal waveform 370 plunges vertically from approximately 100 amperes through zero current as shown in by vertical line 370c. Transition between the negative portion 370b and positive portion 370a also starts a vertical transition at the switching point causing a vertical transition 370d. In a like manner, phase shifted waveform 372 of arc AC2 has a small penetration portion 372a and a large negative deposition portion 372b. Transition between polarities is indicated by vertical lines 372c and 372d. Waveform 372 is shifted with respect to waveform 370 so that the dynamics of the puddle are controlled without excessive collapsing or repulsion of the molten metal in the puddle caused by polarities of adjacent arcs AC1, AC2. In FIG. 11, the sine wave shapes are the same and the frequencies are the same. They are merely shifted to prevent a long term occurrence of a specific polarity relationship. In FIG. 12 waveform 380 is used for arc AC1 and waveform 372 is used for arc AC2. Portions 380a, 380b, 382a, and 382b are sinusoidal synthesized and are illustrated as being of the same general magnitude. By shifting these two waveforms 90°, areas of concurrent polarity are identified as areas 390, 392, 394 and 396. By using the shifted waveforms with sinusoidal profiles, like polarities or opposite polarities do not remain for any length of time. Thus, the molten metal puddle is not agitated and remains quiescent. This advantage is obtained by using the present invention which also combines the concept of a difference in energy between the positive and negative polarity portions of a given waveform. FIG. 12 is illustrative in nature to show the definition of concurrent polarity relationships and the fact that they should remain for only a short period of time. To accomplish this objective, another embodiment of the present invention is illustrated in FIG. 13 wherein previously defined waveform 380 is combined with waveform 400, shown as the sawtooth waveform of arc AC2(a) or the pulsating waveform 402 shown as the waveform for arc AC2(b). Combining waveform 380 with the different waveform 400 of a different waveform 402 produces very small areas or times of concurrent polarity relationships 410, 412, 414, etc. In FIG. 14 the AC waveform generated at one arc is drastically different than the AC waveform generated at the other arc. This same concept of drastically different waveforms for use in the present invention is illustrated in FIG. 14 wherein waveform 420 is an AC pulse profile waveform and waveform 430 is a sinusoidal profile waveform having about one-half the period of waveform 420. Waveform 420 includes a small penetration positive portion 420a and a large deposition portion 420b with straight line polarity transitions 420c. Waveform 430 includes positive portion 430a and negative portion 430b with vertical polarity transitions 430c. By having these two different waveforms, both the synthesized sinusoidal concept is employed for one electrode and there is no long term concurrent polarity relationship. Thus, the molten metal in puddle P remains somewhat quiescent during the welding operation by both arcs AC1, AC2. In FIG. 15 waveforms 450, 452, 454 and 456 are generated by the wave shaper 240 of the power supply for each of four tandem arcs, arc AC1, arc AC2, arc AC3 and arc AC4. The adjacent arcs are aligned as indicated by synchronization signal 460 defining when the waveforms correspond and transition from the negative portion to the positive portion. This synchronization signal is created by generator 80 shown in FIG. 1, except the start pulses are aligned. In this embodiment of the invention first waveform 450 has a positive portion 450a, which is synchronized with both the positive and negative portion of the adjacent waveform 452, 454 and 456. For instance, positive portion 450a is synchronized with and correlated to positive portion 452a and negative portion 452b of waveform 452. In a like manner, the positive portion 452a of waveform 452 is synchronized with and correlated to positive portion 454a and negative portion 454b of waveform 454. The same relationship exist between positive portion 454a and the portions 456a, 456b of waveform 456. The negative portion 450b is synchronized with and correlated to the two opposite polarity portions of aligned waveform 452. The same timing relationship exist between negative portion 452b and waveform 454. In other words, in each adjacent arc one polarity portion of the waveform is correlated to a total waveform of the adjacent arc. In this manner, the collapse and repelling forces of puddle P, as discussed in connection with FIGS. 9 and 10, are dynametically controlled. One or more of the positive or negative portions can be synthesized sinusoidal waves as discussed in connection with the waveforms disclosed in FIGS. 11 and 12. As indicated in FIGS. 1 and 2, when the master controller of switches is to switch, a switch command is issued to master controller 140a of power supply 30. This causes a “kill” signal to be received by the master so a kill signal and polarity logic is rapidly transmitted to the controller of one or more slave power supplies connected in parallel with a single electrode. If standard AC power supplies are used with large snubbers in parallel with the polarity switches, the slave controller or controllers are immediately switched within 1-10 μs after the master power supply receives the switch command. This is the advantage of the high accuracy interface cards or gateways. In practice, the actual switching for current reversal of the paralleled power supplies is not to occur until the output current is below a given value, i.e. about 100 amperes. This allows use of smaller switches. The implementation of the switching for all power supplies for a single AC arc uses the delayed switching technique where actual switching can occur only after all power supplies are below the given low current level. The delay process is accomplished in the software of the digital processor and is illustrated by the schematic layout of FIG. 16. When the controller of master power supply 500 receives a command signal as represented by line 502, the power supply starts the switching sequence. The master outputs a logic on line 504 to provide the desired polarity for switching of the slaves to correspond with polarity switching of the master. In the commanded switch sequence, the inverter of master power supply 500 is turned off or down so current to electrode E is decreased as read by hall effect transducer 510. The switch command in line 502 causes an immediate “kill” signal as represented by line 512 to the controllers of paralleled slave power supplies 520, 522 providing current to junction 530 as measured by hall effect transducers 532, 534. All power supplies are in the switch sequence with inverters turned off or down. Software comparator circuits 550, 552, 554 compare the decreased current to a given low current referenced by the voltage on line 556. As each power supply decreases below the given value, a signal appears in lines 560, 562, and 564 to the input of a sample and hold circuits 570, 572, and 574, respectively. The circuits are outputted by a strobe signal in line 580 from each of the power supplies. When a set logic is stored in a circuit 570, 572, and 574, a YES logic appears on lines READY1, READY2, and READY3 at the time of the strobe signal. This signal is generated in the power supplies and has a period of 25 μs; however, other high speed strobes could be used. The signals are directed to controller C of the master power supply, shown in dashed lines in FIG. 8. A software ANDing function represented by AND gate 580 has a YES logic output on line 582 when all power supplies are ready to switch polarity. This output condition is directed to clock enable terminal ECLK of software flip flop 600 having its D terminal provided with the desired logic of the polarity to be switched as appearing on line 504. An oscillator or timer operated at about 1 MHz clocks flip flop by a signal on line 602 to terminal CK. This transfers the polarity command logic on line 504 to a Q terminal 604 to provide this logic in line 610 to switch slaves 520, 522 at the same time the identical logic on line 612 switches master power supply 500. After switching, the polarity logic on line 504 shifts to the opposite polarity while master power supply awaits the next switch command based upon the switching frequency. Other circuits can be used to effect the delay in the switching sequence; however, the illustration in FIG. 16 is the present scheme. As so far described in FIGS. 1-16, the welder, and control system for the welder to accomplish other advantageous features is submitted as background information. This description explains the background, not prior art, to the present invention. This background technology has been developed by The Lincoln Electric Company, assignee of the present application. This background description is not necessarily prior art, but is submitted for explanation of the specific improvement in such waveform technology welders, as accomplished by the present invention shown in FIGS. 17 AND 18. The welder and/or welding system as shown in FIGS. 4 and 5, is operated by control program 700 constructed in accordance with the present invention. Program 700 is illustrated in FIG. 17, where welder W has a wave shaper 240 set to a general type of weld waveformby a select network 250. The selected waveform is the desired AC waveform to perform, by a succession of waveforms, a given welding process. In accordance with the invention, waveform control program 700 has a profile control network 710 to set the desired general profile of the waveform and a magnitude control circuit 712 to adjust the energy or power of the waveform without substantially changing the set profile. In accordance with the invention, the program or control network 700 is connected to the wave shaper 240 to control the exact general profile of each individual waveform in the succession of waveforms constituting an AC welding process. To accomplish this objective of accurate and precise synergistic setting of the waveform general profile, four separate profile parameters are adjusted individually. The first parameter is frequency set into the waveform profile by circuit 720 manually or automatically adjusted by interface network 722 to produce a set value on an output represented as line 724. This value controls the set frequency of the waveform profile. Of course, this is actually the period of the waveform. In a like manner, the duty cycle of the waveform is controlled by circuit 730 having an adjustable interface network 732 and an output line 734 for developing a value to control the relationship between the positive half cycle and the negative half cycle. This profile parameter is set by the logic or data on line 754 from circuit 730. By the signal or data on line 724 and the data on line 734, the AC profile of the waveform is set. This does not relate to the energy level of the individual portions of the waveform, but merely the general fixed profile of the waveform. To control the up ramp rate of the waveform there is provided a circuit 742 having a manual or automatic adjusting network 742 and an output signal on line 744 for setting the rate at which the set profile of the waveform changes from negative to a positive polarity. In a like manner, a down ramp circuit 750 is provided with an adjusting interface 752 and an output line 754. The magnitudes of the values on lines 724, 734, 744 and 754 set the general profile of the individual waveform. In accordance with the invention, at least two of these parameter profiles are set together; however, preferably all of the profile parameters are set to define a general waveform profile. To control the general profile of the waveform for the purposes of the energy or power transmitted by each individual waveform in the welding process, the present invention includes magnitude circuit or network 712 divided into two individual sections 760, 762. These sections of the magnitude circuit control the energy or other power related level of the waveform during each of the polarities without substantially affecting the general profile set by profile control network 710. In accordance with the illustrated embodiment of the invention, section 760 includes a level control circuit 770 which is manually adjusted by an interface network 772 to control the relationship between an input value on line 774 and an output value on line 776. Level control circuit 770 is essentially a digital error amplifier circuit for controlling the current, voltage and/or power during the positive portion of the generated set waveform profile. Selector 250a shifts circuit 770 into either the current, voltage or power mode. Section 760 controls the energy, or power or other heat level during the positive portion of the waveform with changing the general profile set by network 710. In a like manner, second section 762 has a digital error amplifier circuit 760 that is set or adjusted by network 782 so that the value on input line 784 controls the level or signal on output line 786. Consequently, the digital level data on lines 776 and 786 controls the current, voltage and/or power during each of the half cycles set by profile control network 710. In accordance with another aspect of the invention, wave shaper 240 is controlled by only magnitude control circuit 712 and the profile is set by network or program 250 used in the background system shown in FIGS. 4 and 5. Network 250 does not set the general profile, but selects known types of waveforms. The enhanced advantage of the present invention is realized by setting all profile parameters using circuits 720, 730, 740 and 750 together with the magnitude circuits 770, 780. Of course, a waveform controlled by any one of these circuits is an improvement over the background technology. The invention is a synergistic control of all of the profile parameters and magnitude values during each polarity of the AC waveform. To explain the operation of the invention two waveforms are schematically illustrated in FIG. 18. Waveform 800 has a positive portion 802 and a negative portion 804, both produced by a series of rapidly created current pulses 800a. Waveform 800 is illustrated as merely a square wave to illustrate control of the frequency or period of the waveform and the ratio of the positive portion 802 to the negative portion 804. These parameters are accurately set by using the invention to modify the type of waveform heretofore merely selected by network 450. In this schematic representation of the waveform, the up ramp rate and the down ramp rate are essentially zero. Of course, the switching concept taught in Stava U.S. Pat. No. 6,111,216 would be employed for shifting between positive and negative waveform portions to obtain the advantages described in the Stava patent. Second illustrated waveform 810 has a frequency f, a positive portion 812 and a negative portion 814. In this illustration, the up ramp rate 816 is controlled independently of the down ramp rate 818. These ramp rates are illustrated as arrows to indicate they exist at the leading and trailing edges of the waveform during shifts between polarities. The present invention relates to setting the exact profile of the individual waveforms by circuits 720, 730, 740 and 750. The invention involves setting several parameters to essentially “paint” the waveform into a desired general profile. A very precise welding process using a set general profile for the AC waveform is performed by a waveform technology controlled welder using the present invention. | <SOH> BACKGROUND OF INVENTION <EOH>Welding applications, such as pipe welding, often require high currents and use several arcs created by tandem electrodes. Such welding systems are quite prone to certain inconsistencies caused by arc disturbances due to magnetic interaction between two adjacent tandem electrodes. A system for correcting the disadvantages caused by adjacent AC driven tandem electrodes is disclosed in Stava U.S. Pat. No. 6,207,929. In that prior patent, each of the AC driven electrodes has its own inverter based power supply. The output frequency of each power supply is varied so as to prevent interference between adjacent electrodes. This system requires a separate power supply for each electrode. As the current demand for a given electrode exceeds the current rating of the inverter based power supply, a new power supply must be designed, engineered and manufactured. Thus, such system for operating tandem welding electrodes require high capacity or high rated power supplies to obtain high current as required for pipe welding. To decrease the need for special high current rated power supplies for tandem operated electrodes, assignee developed the system disclosed in Stava U.S. Pat. No. 6,291,798 wherein each AC electrode is driven by two or more inverter power supplies connected in parallel. These parallel power supplies have their output current combined at the input side of a polarity switching network. Thus, as higher currents are required for a given electrode, two or more parallel power supplies are used. In this system, each of the power supplies are operated in unison and share equally the output current. Thus, the current required by changes in the welding conditions can be provided only by the over current rating of a single unit. A current balanced system did allow for the combination of several smaller power supplies; however, the power supplies had to be connected in parallel on the input side of the polarity reversing switching network. As such, large switches were required for each electrode. Consequently, such system overcame the disadvantage of requiring special power supplies for each electrode in a tandem welding operation of the type used in pipe welding; but, there is still the disadvantage that the switches must be quite large and the input, paralleled power supplies must be accurately matched by being driven from a single current command signal. Stava U.S. Pat. No. 6,291,798 does utilize the concept of a synchronizing signal for each welding cell directing current to each tandem electrode. However, the system still required large switches. This type of system was available for operation in an ethernet network interconnecting the welding cells. In ethernet interconnections, the timing cannot be accurately controlled. In the system described, the switch timing for a given electrode need only be shifted on a time basis, but need not be accurately identified for a specific time. Thus, the described system requiring balancing the current and a single switch network has been the manner of obtaining high capacity current for use in tandem arc welding operations when using an ethernet network or an internet and ethernet control system. There is a desire to control welders by an ethernet network, with or without an internet link. Due to timing limitation, these networks dictated use of tandem electrode systems of the type using only general synchronizing techniques. Such systems could be controlled by a network; however, the parameter to each paralleled power supply could not be varied. Each of the cells could only be offset from each other by a synchronizing signal. Such systems were not suitable for central control by the internet and/or local area network control because an elaborate network to merely provide offset between cells was not advantageous. Houston U.S. Pat. No. 6,472,634 discloses the concept of a single AC arc welding cell for each electrode wherein the cell itself includes one or more paralleled power supplies each of which has its own switching network. The output of the switching network is then combined to drive the electrode. This allows the use of relatively small switches for polarity reversing of the individual power supplies paralleled in the system. In addition, relatively small power supplies can be paralleled to build a high current input to each of several electrodes used in a tandem welding operation. The use of several independently controlled power supplies paralleled after the polarity switch network for driving a single electrode allows advantageous use of a network, such as the internet or ethernet. In Houston U.S. Pat. No. 6,472,634, smaller power supplies in each system are connected in parallel to power a single electrode. By coordinating switching points of each paralleled power supply with a high accuracy interface, the AC output current is the sum of currents from the paralleled power supplies without combination before the polarity switches. By using this concept, the ethernet network, with or without an internet link, can control the weld parameters of each paralleled power supply of the welding system. The timing of the switch points is accurately controlled by the novel interface, whereas the weld parameters directed to the controller for each power supply can be provided by an ethernet network which has no accurate time basis. Thus, an internet link can be used to direct parameters to the individual power supply controllers of the welding system for driving a single electrode. There is no need for a time based accuracy of these weld parameters coded for each power supply. In the preferred implementation, the switch point is a “kill” command awaiting detection of a current drop below a minimum threshold, such as 100 amperes. When each power supply has a switch command, then they switch. The switch points between parallel power supplies, whether instantaneous or a sequence involving a “kill” command with a wait delay, are coordinated accurately by an interface card having an accuracy of less than 10 μs and preferably in the range of 1-5 μs. This timing accuracy coordinates and matches the switching operation in the paralleled power supplies to coordinate the AC output current. By using the internet or ethernet local area network, the set of weld parameters for each power supply is available on a less accurate information network, to which the controllers for the paralleled power supplies are interconnected with a high accuracy digital interface card. Thus, the switching of the individual, paralleled power supplies of the system is coordinated. This is an advantage allowing use of the internet and local area network control of a welding system. The information network includes synchronizing signals for initiating several arc welding systems connected to several electrodes in a tandem welding operation in a selected phase relationship. Each of the welding systems of an electrode has individual switch points accurately controlled while the systems are shifted or delayed to prevent magnetic interference between different electrodes. This allows driving of several AC electrodes using a common information network. The Houston U.S. Pat. No. 6,472,634 system is especially useful for paralleled power supplies to power a given electrode with AC current. The switch points are coordinated by an accurate interface and the weld parameter for each paralleled power supply is provided by the general information network. This background is technology developed and patented by assignee and does not necessarily constitute prior art just because it is herein used as “background.” As a feature of the system in Stava U.S. Pat. No. 6,207,929, two or more power supplies can drive a single electrode. Thus, the system comprises a first controller for a first power supply to cause the first power supply to create an AC current between the electrode and workpiece by generating a switch signal with polarity reversing switching points in general timed relationship with respect to a given system synchronizing signal received by the first controller. This first controller is operated at first welding parameters in response to a set of first power supply specific parameter signals directed to the first controller. There is provided at least one slave controller for operating the slave power supply to create an AC current between the same electrode and workpiece by reversing polarity of the AC current at switching points. The slave controller operates at second weld parameters in response to the second set of power supply specific parameter signals to the slave controller. An information network connected to the first controller and the second or slave controller contains digital first and second power supply specific parameter signals for the two controllers and the system specific synchronizing signal. Thus, the controllers receive the parameter signals and the synchronizing signal from the information network, which may be an ethernet network with or without an internet link, or merely a local area network. The invention involves a digital interface connecting the first controller and the slave controller to control the switching points of the second or slave power supply by the switch signal from the first or master controller. In practice, the first controller starts a current reversal at a switch point. This event is transmitted at high accuracy to the slave controller to start its current reversal process. When each controller senses an arc current less than a given number, a “ready signal” is created. After a “ready” signal from all paralleled power supplies, all power supplies reverse polarity. This occurs upon receipt of a strobe or look command each 25 μs. Thus, the switching is in unison and has a delay of less than 25 μs. Consequently, both of the controllers have interconnected data controlling the switching points of the AC current to the single electrode. The same controllers receive parameter information and a synchronizing signal from an information network which in practice comprises a combination of internet and ethernet or a local area ethernet network. The timing accuracy of the digital interface is less than about 10 μs and, preferably, in the general range of 1-5 μs. Thus, the switching points for the two controllers driving a single electrode are commanded within less than 5 μs. Then, switching actually occurs within 25 μs. At the same time, relatively less time sensitive information is received from the information network also connected to the two controllers driving the AC current to a single electrode in a tandem welding operation. The 25 μs maximum delay can be changed, but is less than the switch command accuracy. The unique control system disclosed in Houston U.S. Pat. No. 6,472,634 is used to control the power supply for tandem electrodes used primarily in pipe seam welding and disclosed in Stava U.S. Pat. No. 6,291,798. This Stava patent relates to a series of tandem electrodes movable along a welding path to lay successive welding beads in the space between the edges of a rolled pipe or the ends of two adjacent pipe sections. The individual AC waveforms used in this unique technology are created by a number of current pulses occurring at a frequency of at least 18 kHz with a magnitude of each current pulse controlled by a wave shaper. This technology dates back to Blankenship U.S. Pat. No. 5,278,390. Shaping of the waveforms in the AC currents of two adjacent tandem electrodes is known and is shown in not only the patents mentioned above, but in Stava U.S. Pat. No. 6,207,929. In this latter Stava patent, the frequency of the AC current at adjacent tandem electrodes is adjusted to prevent magnetic interference. All of these patented technologies by The Lincoln Electric Company of Cleveland, Ohio have been advances in the operation of tandem electrodes each of which is operated by a separate AC waveform created by the waveform technology set forth in these patents. These patents are incorporated by reference herein. However, these patents do not disclose the present invention which is directed to the use of such waveform technology for use in tandem welding by adjacent electrodes each using an AC current. This technology, as the normal transformer technology, has experienced difficulty in controlling the dynamics of the weld puddle. Thus, there is a need for an electric arc welding system for adjacent tandem electrodes which is specifically designed to control the dynamics and physics of the molten weld puddle during the welding operation. These advantages can not be obtained by merely changing the frequency to reduce the magnetic interference. | <SOH> BRIEF DESCRIPTION OF DRAWINGS <EOH>FIG. 1 is a block diagram of a welding system that can be used to perform the present invention; FIG. 2 is a wiring diagram of two paralleled power sources, each of which include a switching output and can be used in practicing the invention; FIG. 3 is a cross sectional side view of three tandem electrodes of the type controllable by the power source disclosed in FIGS. 1 and 2 ; FIG. 4 is a schematic layout in block form of a welding system for three electrodes using the disclosure in Houston U.S. Pat. No. 6,472,634 and Stava U.S. Pat. No. 6,291,798 and where one of the three power sources is used in practicing the invntion as shown in FIGS. 17 and 18 ; FIG. 5 is a block diagram showing a single electrode driven by the system as shown in FIG. 4 with a variable pulse generator disclosed in Houston U.S. Pat. No. 6,472,634 and used for practicing the present invention; FIG. 6 is a current graph for one of two illustrated synchronizing pulses and showing a balanced AC waveform for one tandem electrode; FIG. 7 is a current graph superimposed upon a polarity signal having logic to determine the polarity of the waveform as used in a welder that can practice the present invention; FIG. 8 is a current graph showing a broad aspect of a waveform with a profile controllable by the present invention; FIGS. 9 and 10 are schematic drawings illustrating the dynamics of the weld puddle during concurrent polarity relationships of tandem electrodes; FIG. 11 is a pair of current graphs showing the waveforms on two adjacent tandem electrodes that can be generated by a background system; FIG. 12 is a pair of current graphs of the AC waveforms on adjacent tandem electrodes with areas of concurring polarity relationships; FIG. 13 are current graphs of the waveforms on adjacent tandem electrodes wherein the AC waveform of one electrode is substantially different waveform of the other electrode to limit the time of concurrent polarity relationships; FIG. 14 are current graphs of two sinusoidal waveforms for adjacent electrodes operated by a background system to use different shaped wave forms for the adjacent electrodes; FIG. 15 are current graphs showing waveforms at four adjacent AC arcs of tandem electrodes shaped and synchronized in accordance with a background aspect of the invention; FIG. 16 is a schematic layout of a known software program to cause switching of the paralleled power supplies as soon as the coordinated switch commands have been processed and the next coincident signal has been created; FIG. 17 is a block diagram of the program used in the computer controller to improve the background system shown in FIGS. 1-16 so a welder performs in accordance with the preferred embodiment of the present invention; and, FIG. 18 is a schematically illustrated waveform used in explaining the implementation of the present invention. detailed-description description="Detailed Description" end="lead"? | 20040301 | 20060530 | 20050901 | 68571.0 | 1 | SHAW, CLIFFORD C | ELECTRIC ARC WELDER SYSTEM WITH WAVEFORM PROFILE CONTROL | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,789,974 | ACCEPTED | Methods of evaluating undersaturated coalbed methane reservoirs | The evaluation and assessment of geologic formations comprising undersaturated coalbed methane reservoirs. In some embodiments, the present invention provides for inductively quantifying critical desorption pressure of the solid in an undersaturated coalbed methane reservoir from an unrelated substance, the formation water. By using these techniques, the characterization of undersaturated coalbed methane reservoirs may be more quickly and economically made based upon a methane content characteristic such as critical desorption pressure, gas content, and in some embodiments gas content as calculated from isotherm evaluation, estimates of dewatering for production, and ratios of critical desorption pressure to initial reservoir pressure, among other possible characteristics. The features of the invention may further have applicability in combination with conventional reservoir analysis, such as coring, logging, reservoir isotherm evaluation, or other techniques. | 1. A method of evaluating an undersaturated coalbed methane reservoir comprising the steps of: a. accessing a well admitted to an undersaturated coalbed methane reservoir; b. sampling formation water from said undersaturated coalbed methane reservoir; c. conducting a test based on said formation water sample; d. inductively quantifying a methane content characteristic of sorbed methane that is sorbed in a solid formation substance from said water sample; and e. characterizing said coalbed methane reservoir based upon said inductively quantified methane content characteristic. 2. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 wherein said step of sampling formation water from said undersaturated coalbed methane reservoir comprises the step of capturing substantially pure formation fluid. 3. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 wherein said step of sampling formation water from said undersaturated coalbed methane reservoir comprises the step of assuring that said formation water sample is representative of fluid from said undersaturated coalbed methane reservoir. 4. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 3 wherein said step of assuring that said formation water sample is representative of fluid from said undersaturated coalbed methane reservoir comprises the step of producing at least a well pathway volume of fluid. 5. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 3 wherein said step of assuring that said formation water sample is representative of fluid from said undersaturated coalbed methane reservoir comprises the step of producing at least a well tubing volume of fluid. 6-7. (canceled) 8. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 and further comprising the step of having a constant fluid production from said well at the time of said sampling. 9. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 wherein said well has a well bottom and wherein said step of sampling formation water from said undersaturated coalbed methane reservoir comprises the step of collecting a single phase fluid from about said well bottom. 10. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 wherein said step of sampling formation water from said undersaturated coalbed methane reservoir comprises the step of effecting only a small drawdown. 11. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 10 wherein said step of effecting only a small drawdown comprises the step of effecting only a small drawdown for a long period of time. 12. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 11 wherein said step of effecting only a small drawdown for a long period of time comprises the step of effecting only a small drawdown for a period of time selected from a group consisting of about one week, several days, about one day, longer than a traditional formation water sampling time. 13. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 10 wherein said step of sampling formation water from said undersaturated coalbed methane reservoir comprises the step of sampling formation water after a period of nonproduction from said well. 14. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 wherein said step of sampling formation water from said undersaturated coalbed methane reservoir comprises the step of sampling formation water until a gas-water ratio of said water is constant. 15. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 wherein said step of sampling formation water from said undersaturated coalbed methane reservoir comprises the step of contained sampling said formation water. 16-26. (canceled) 27. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 wherein said step of conducting a test based on said formation water sample comprises the step of on-site testing of said formation water. 28. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 wherein said step of conducting a test based on said formation water sample comprises the step of determining a gas-water ratio of said formation water. 29. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 28 wherein said step of determining a gas-water ratio of said formation water comprises the step of directly testing said gas-water ratio of said formation water. 30. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 29 wherein said step of directly testing said gas-water ratio of said formation water comprises the step of on-site testing of said formation water. 31. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 30 wherein said step of on-site testing of said formation water comprises the step of conducting a surface test of said formation water. 32. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 31 wherein said step of conducting a surface test of said formation water comprises the step of capturing gas from said undersaturated coalbed methane reservoir. 33. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 28 wherein said step of determining a gas-water ratio of said formation water comprises the step of testing the total gas content of said formation water. 34. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 28 wherein said step of determining a gas-water ratio of said formation water comprises the step of deducing said gas-water ratio of said formation water. 35. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 34 wherein said step of deducing said gas-water ratio of said formation water comprises the steps of: a. measuring gas factors at a plurality of pressures; and b. creating a curve based at least in part on said step of measuring gas factors at a plurality of pressures. 36. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 wherein said step of conducting a test based on said formation water sample comprises the step of determining a bubble point of said formation water. 37. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 36 wherein said step of determining a bubble point of said formation water comprises the step of directly testing said bubble point of said formation water. 38. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 37 wherein said step of directly testing said bubble point of said formation water comprises the step of on-site testing of said formation water. 39. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 38 wherein said step of directly testing said bubble point of said formation water comprises the step of conducting a surface test of said formation water. 40. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 39 wherein said step of directly testing said bubble point of said formation water comprises the step of testing said formation water during drilling. 41. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 39 wherein said step of directly testing said bubble point of said formation water comprises the steps of: a. releasing pressure from a contained volume; and b. observing a change resulting from said release of pressure. 42. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 41 wherein said step of sampling formation water from said undersaturated coalbed methane reservoir comprises the step of contained sampling said formation water. 43. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 38 wherein said step of directly testing said bubble point of said formation water comprises the step of acoustically testing. 44. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 38 wherein said step of directly testing said bubble point of said formation water comprises the step of sensing a differential pressure drop. 45. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 36 wherein said step of inductively quantifying a methane content characteristic of sorbed methane that is sorbed in a solid formation substance from said water sample comprises the step of using a bubble point of said formation water to imply a critical desorption pressure of said undersaturated coalbed methane reservoir. 46. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 36 wherein said step of determining a bubble point of said formation water comprises the step of assuming all gas sorbed in said formation water is methane. 47. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 36 wherein said step of determining a bubble point of said formation water comprises the step of directly testing said bubble point of said formation water. 48. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 36 wherein said step of determining a bubble point of said formation water comprises the step of deducing said bubble point of said formation water. 49. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 48 wherein said step of deducing said bubble point of said formation water comprises the steps of: a. measuring gas factors at a plurality of pressures; and b. creating a curve based at least in part on said step of measuring gas factors at a plurality of pressures. 50. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 48 wherein said step of deducing said bubble point of said formation water comprises the step of utilizing publicly available, predetermined data similar to data of the solubility of methane in water at various pressures for a given temperature. 51. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 48 wherein said step of deducing said bubble point of said formation water comprises the step of utilizing the mathematical functional relationship of solution gas-water ratio as a function of pressure with constants from publicly available predetermined data. 52. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 48 wherein said step of deducing said bubble point of said formation water comprises the step of combining functional foundations of a plurality of relationships to achieve a predicted relationship of bubble point to pressure of the desired pressure range applicable to the particular situation. 53. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 48 wherein said step of deducing said bubble point of said formation water comprises the steps of: a. extrapolating beyond measured data; and b. utilizing an expected zero crossing point. 54. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 48 wherein said step of deducing said bubble point of said formation water comprises the step of ignoring corrections to data for temperatures of less than one hundred degrees Fahrenheit. 55. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 48 wherein said step of deducing said bubble point of said formation water comprises the step of ignoring corrections to data for other than fresh water. 56. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 48 wherein said step of deducing said bubble point of said formation water comprises the step of ignoring corrections to data for sorbed gas other than methane. 57. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 48 wherein said step of deducing said bubble point of said formation water comprises the step of utilizing publicly available, predetermined values for various temperature effects. 58. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 49 wherein said step of deducing said bubble point of said formation water further comprises the step of accomplishing a curve fitting function to a given set of data points. 59. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 58 wherein said step of accomplishing a curve fitting function to a given set of data points comprises the step of utilizing a cubic equation. 60. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 48 wherein said step of deducing said bubble point of said formation water comprises the steps of: a. utilizing predetermined data having a lowest pressure at a pressure greater than that of interest; and b. extrapolating from said lowest pressure for said predetermined data to a substantially zero value at a zero pressure to obtain data applicable to a pressure of interest. 61. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 60 wherein said step of utilizing predetermined data having a lowest pressure at a pressure greater than that of interest comprises the step of utilizing salinity-based predetermined data. 62-70. (canceled) 71. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 wherein said step of conducting a test based on said formation water sample comprises the step of capturing gas from said undersaturated coalbed methane reservoir. 72. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 71 wherein said step of conducting a test based on said formation water sample comprises the step of separating gas and formation water from said well. 73. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 72 wherein said step of separating gas and formation water from said well comprises the step of utilizing a bubble pail apparatus on site. 74. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 72 wherein said step of separating gas and formation water from said well comprises the step of utilizing a separation barrel apparatus and an orifice well tester on site. 75-83. (canceled) 84. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 wherein said step of inductively quantifying a methane content characteristic of sorbed methane that is sorbed in a solid formation substance from said water sample comprises the step of inferring a critical desorption pressure for a methane-containing solid from said step of conducting a test based on said formation water sample. 85. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 wherein said step of inductively quantifying a methane content characteristic of sorbed methane that is sorbed in a solid formation substance from said water sample comprises the step of utilizing an inverse gas-water ratio functional relationship. 86. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 wherein said step of characterizing said coalbed methane reservoir based upon said inductively quantified methane content characteristic comprises the step of determining a likely amount of methane production available from said well upon production. 87. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 86 wherein said step of determining a likely amount of methane production available from said well upon production comprises the step of utilizing an inferred critical desorption pressure for a solid within said undersaturated coalbed methane reservoir. 88. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 87 wherein said step of characterizing said coalbed methane reservoir based upon said inductively quantified methane content characteristic comprises the step of utilizing a saturated coalbed methane isotherm for said undersaturated coalbed methane reservoir. 89. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 88 wherein said step of utilizing a saturated coalbed methane isotherm for said undersaturated coalbed methane reservoir comprises the step of utilizing data representative of a Langmuir isotherm. 90-98. (canceled) 99. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 wherein said step of characterizing said coalbed methane reservoir based upon said inductively quantified methane content characteristic comprises the step of estimating a dewatering value for said reservoir. 100. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 and further comprising the step of commercially producing methane from said well. 101. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 wherein said step of characterizing said coalbed methane reservoir based upon said inductively quantified methane content characteristic comprises the step of determining an approximate drop in reservoir pressure needed for gas to be produced from said well. 102. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 wherein said step of characterizing said coalbed methane reservoir based upon said inductively quantified methane content characteristic comprises the step of estimating an economic factor for commercial production from said well. 103. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 102 wherein said step of estimating an economic factor for commercial production from said well comprises the step of prioritizing a plurality of wells based on economic considerations. 104. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 wherein said step of characterizing said coalbed methane reservoir based upon said inductively quantified methane content characteristic comprises the step of comparing said well to screening criterion. 105. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 104 wherein said step of comparing said well to a screening criterion comprises the step of comparing said well to a screening criterion selected from a group consisting of: a screening criterion based upon a reservoir pressure, a screening criterion based upon a permeability of said undersaturated coalbed methane reservoir, a screening criterion based upon the apparent critical desorption pressure of coal in said undersaturated coalbed methane reservoir, a screening criterion based upon the estimated dewatering needs of said undersaturated coalbed methane reservoir, a screening criterion based upon the degree of undersaturation of said undersaturated coalbed methane reservoir, a screening criterion based upon current prices of gas, a screening criterion based upon projected prices of gas, and a set value of gas content. 106. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 and further comprising the step of commercially producing methane from a well that had previously been deemed to be uneconomic. 107-112. (canceled) 113. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 1 wherein said step of sampling formation water from said undersaturated coalbed methane reservoir comprises the step of obtaining multiple samples of formation water from said well. 114-115. (canceled) 116. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 113 and further comprising the step of achieving a constancy in said multiple samples of formation water from said well. 117-119. (canceled) 120. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 116 wherein said step of achieving a constancy in said comparing the results of said multiple similar tests through alteration of actions affecting said step of sampling formation water from said undersaturated coalbed methane reservoir comprises the step of achieving a substantially constant gas-water ratio result for said formation water. 121. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 116 wherein said step of achieving a constancy in said comparing the results of said multiple similar tests through alteration of actions affecting said step of sampling formation water from said undersaturated coalbed methane reservoir comprises the step of achieving a substantially constant bubble point result for said formation water. 122. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 116 wherein said step of achieving a constancy in said comparing the results of said multiple similar tests through alteration of actions affecting said step of sampling formation water from said undersaturated coalbed methane reservoir comprises the step of achieving a substantially constant critical desorption pressure result. 123. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 116 wherein said step of sampling formation water from said undersaturated coalbed methane reservoir comprises the step of capturing both gas and water from said well. 124-144. (canceled) 145. A method of evaluating an undersaturated coalbed methane reservoir comprising the steps of: a. accessing an existing unproductive well admitted to a coalbed methane reservoir; b. sampling formation water from said coalbed methane reservoir; c. conducting a test based on said formation water sample; and d. estimating an economic factor for commercial production from said well based upon said step of conducting a test based on said formation water sample. 146. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 145 wherein said step of accessing an existing unproductive well admitted to a coalbed methane reservoir comprises the step of accessing an existing water producing well admitted to a coalbed methane reservoir. 147. A method of evaluating an undersaturated coalbed methane reservoir as described in claim 145 wherein said step of estimating an economic factor for commercial production from said well based upon said step of conducting a test based on said formation water sample comprises the step of estimating when said well is likely to commercially produced methane. 148-151. (canceled) 152. A dynamic method of surface sampling subsurface formation water comprising the steps of: a. accessing a well admitted to an undersaturated coalbed methane reservoir; b. assuring that a formation water sample is representative of fluid from said undersaturated coalbed methane reservoir; c. initially sampling formation water from said undersaturated coalbed methane reservoir; d. conducting an initial test based on said initial formation water sample; e. additionally sampling formation water from said undersaturated coalbed methane reservoir; f. conducting a similar test based on said additional formation water sample; g. comparing results of said initial sampling and said additional sampling; and h. achieving a constancy in said comparing the results through alteration of actions affecting said step of sampling formation water from said undersaturated coalbed methane reservoir. 153. A dynamic method of surface sampling subsurface formation water as described in claim 152 wherein said step of achieving a constancy in said comparing the results of said multiple similar tests through alteration of actions affecting said step of sampling formation water from said undersaturated coalbed methane reservoir comprises the step of altering a production rate from said well. 154-172. (canceled) | This patent claims the benefit of both U.S. Application No. 60/451,218 filed Feb. 28, 2003 and U.S. Application No. 60/527,130 filed Dec. 5, 2003, each incorporated herein by reference. FIELD OF THE INVENTION The present invention relates generally to the evaluation and assessment of geologic formations comprising undersaturated coalbed methane reservoirs. Such reservoirs usually have cleats and fractures initially saturated with water (i.e. no free gas phase exists at reservoir conditions) and may represent gas-water systems. Specifically, the present invention can provide methods of indirectly deducing important attributes relative to methane that is sorbed in a solid formation substance such as coal from tests of other than the coal itself. It permits a determination of critical desorption pressure of methane contained in the solid formations of undersaturated coalbed methane reservoirs and undersaturated conditions of the reservoir in general. In some embodiments, economically significant characteristics can be determined such as estimates of dewatering for production, methane content, among other aspects. The features of the invention may further have applicability in combination with conventional reservoir analysis, such as coring, logging, reservoir isotherm evaluation, or other techniques. BACKGROUND OF THE INVENTION Coalbed methane (CBM) is the composite of components that may be adsorbed on coal at the naturally occurring conditions of reservoir pressure and temperature. As pressure is reduced, the CBM begins desorbing from the coal once the critical desorption pressure (CDP) is reached. CBM may consist largely of methane with smaller amounts of impurities, typically nitrogen and carbon dioxide and some minor amounts of intermediate hydrocarbons. The capture and sale of CBM is a burgeoning industry both in the United States and internationally. In the CBM industry, a typical procedure for CBM recovery is often to penetrate the geologic formation with a substantially vertically drilled well and to either 1) case the hole, typically with steel casing through the coal interval followed by cementing the casing in place and perforating the interval all by methods commonly known in the petroleum industry, or 2) to case in a like manner the hole to the top of the coal and then drill through the coal, perhaps widening the hole drilled through the coal by a process known in the industry as underreaming. The former case is known as a cased completion and the latter is known as an open-hole completion. In either case, when producible water is present, typically water is pumped from the well through a tubing string to the surface in an attempt to lower the reservoir pressure, a generally necessary condition for releasing commercial quantities of CBM in most production scenarios. As reservoir pressure is lowered, a free gas phase will eventually form at the bottom of the hole and most of the free gas then will rise in the annulus between the casing and the tubing by gravitational forces, allowing the relatively buoyant gas to be produced at the surface from the annulus of the casing. The gas produced is then gathered and then typically sent to markets through pipelines. Many CBM wells that will ultimately produce commercial quantities of coalbed methane do not do so when first put into production. The only gas produced initially in such wells is the relatively minute, generally noncommercial, quantity of gas that is in solution in the water at bottom-hole conditions of pressure and temperature. Most of this minute quantity will come out of solution as the produced formation water moves from conditions at the bottom of the hole to the lower pressure and typically different temperature at the surface. Such coal formations that do not produce gas initially beyond the amount contained in solution in the formation water are said to be undersaturated at reservoir conditions of pressure and temperature. Other definitions for undersaturated coals include: 1) when the storage capacity of the coal, typically expressed in standard (usually 14.7 psia and 60 deg F.) cubic feet of gas per ton of coal, exceeds the actual gas content of the coal expressed in the same units at reservoir pressure, or 2) when no free gas phase exists in the cleats and fracture system at reservoir conditions. Storage capacity of the coal is typically determined in the laboratory from a captured sample of coal. A plot of the data is often made having the ordinate typically expressed in SCF/Ton and the abscissa being absolute pressure. This data is also often statistically fit with an equation to yield a curve, one such commonly used curve being known as the Langmuir isotherm as described in the reference of Yee et al., 1993. These “isotherms”, as the term implies, are measured at constant temperature generally corresponding to that of the reservoir from which the sample was obtained. Unfortunately, some of the undersaturated CBM reservoirs may never produce commercial quantities of coalbed methane. One concern, therefore, is the determination of whether or not the coals in these undersaturated CBM reservoirs contain sufficient gas to be commercial. Such information, if it could be determined expediently on a given well in an exploratory area, could prevent the drilling of a large number of wells in the specific area that may never produce economic quantities of CBM. As mentioned above, one common method of making that determination is through the process of obtaining a sample of the coal itself, perhaps by coring the coal, and subsequent detailed measurement of gas content of that sample in a laboratory or otherwise. This technique is typically expensive, and can require specialized drilling equipment and personnel. Additional expense may be incurred when the core samples are sent to commercial or private laboratories for analysis. The results of such core analyses are not immediately available, sometimes taking months of desorption time. Also, because core analysis may be too expensive for a large amount of sampling to be taken from a particular well, samples, hoped to be representative, are often selected. Consequently, there is the potential problem of the core samples not being representative of the formation even nearby the well from which the core was cut; and there is an additional problem of how representative the samples will be of the formation at some distance from the well. The CBM industry is replete with examples of how gas content can drastically change over relatively short distances. It is typically neither economically practical nor timely to have every well cored and analyzed. The results from a sample of the coal itself, perhaps from the coring process, can also be very inconsistent from what is ultimately observed during production. During a coring or other sampling operation, not only are samples of coal pulled for determining gas content in the laboratory, but also a specific sample or a composite sample, possibly made up from drill cuttings, may be gathered and this sample used to determine storage capacity of the coal. This can involve tedious and expensive laboratory processes. The commercial or private laboratory may then compare the gas content measured in some samples with the storage capacity determined from another sample and estimate the degree of saturation of the coal. As explained above, if the measured gas content is less than the storage capacity, the coal is said to be undersaturated with gas, and the laboratory will typically determine the pressure at which the gas content intersects a plot of the storage capacity data. The resulting pressure is typically referred to as the critical desorption pressure (CDP). The CDP is the reservoir pressure at which CBM will start to desorb from the coal with reduction of reservoir pressure, become a gaseous phase, and begin to become capable of production in commercial quantities. Unfortunately, the value of CDP determined by the laboratories, too frequently, has been grossly in error from what was ultimately observed when the wells were produced. The present inventor has identified such error in the coring and subsequent laboratory analyses of several of approximately ten wells, analyzed under traditional core analysis using different laboratories. Some analyses have indicated that the reservoirs are saturated at reservoir pressure, yet these reservoirs have not produced any commercial quantities of gas until the reservoir pressure has been drawn down to at least 50 to 60% of the initial reservoir pressure before reaching the CDP. Some of the analyses indicate that the gas contents exceed the storage capacities of the coals at reservoir pressure, something that appears to defy an adequate physical explanation. In summary, coal sampling, coring, and subsequent core analyses as described above may lead to results that are not only time consuming and expensive to obtain, but also they can be highly questionable and frequently inconsistent when used for individualized analysis. For individualized analysis, due to uncertainty, the better use for coal sampling, coring, and core analyses may not come from individual assessments but instead from multiple assessments from which composite isotherms are constructed for a given geological region by averaging of the data and statistically demonstrating the uncertainty. This has been done in the Powder River Basin (PRB) by the United States Bureau of Land Management (BLM) as described in the reference to Crockett and Meyer, 2001. For example, from some 40 samples, the BLM has constructed an averaged synthesized isotherm for samples measured in the PRB representing these 40 samples. Even from such a relatively large number of samples, and ignoring the cost challenges to achieve such data, this effort highlights the challenges in a coal sampling approach because uncertainty in the data still exists. In fact this data shows significantly differing isotherms that represent one standard deviation on either side of the mean curve. Another problem under traditional analysis can, and does, occur in some undersaturated CBM reservoirs when one tries to demonstrate, perhaps through individual testing or small-scale pilots of several adjacent wells, that the well(s) will ultimately produce commercial quantities of CBM. A long and uncertain dewatering period, even under the best of circumstances, may be required before any commercial quantities of CBM are produced. This can lead to long periods of evaluation time. In some areas where there is high permeability and strong aquifer support, such as can be the case in the PRB, one well cannot draw down the pressure sufficiently to ever reach the CDP in any sort of practical or economic time frame. In response to this problem and in an effort to evaluate their leases, most operators have drilled costly (multi-million dollar) multiple-well pilots in an effort to cause interference between wells so that these wells, in combination, can draw the pressure down sufficiently to reach the CDP by exceeding the water influx into the pilot area. Some of these pilots have been successful in the PRB, but some of the pilots have been dewatering for over three years without yet producing commercial quantities of CBM. This dewatering is done at considerable cost of equipment and power to pump wells, at a financial cost of deferred revenues and with the uncertainty that the ultimate resource to be found may not be sufficient to be profitable. The practical challenges of laboratory involvement and sampling difficulty known to exist in a coal sampling-based technique are perhaps highlighted by reference to U.S. Pat. No. 5,785,131 to Gray. Although this reference involves techniques for sensing formation fluids as in gas-oil systems when the fluid itself is of interest, as it relates to the very different aspect of sampling solids containing a substance of interest, it proposes a system for pressurized capture of the samples from entrained particles during drilling. In the reference, these particles of coal or the like are captured and tested on site to avoid some of the mentioned challenges of laboratory testing. As it relates to the solids such as are of interest in the present invention, however, this reference still relies on a capture of the entrained particles and as such it is subject to the uncertainties and other practical limitations discussed above. Another alternative to those techniques based on sampling of the coal itself involves the use of mudlogging during drilling to obtain, at least a qualitative indication of the presence of CBM. Some have even tried to quantify results (Donovan, 2001), but these techniques can leave much to be desired and problems can exist because the system is not usually closed, thus allowing unmeasured gas to escape. Gas-free drilling water is also typically mixed with formation water of different gas content. Further, particle size can need to be estimated, drilling speed recorded, etc. Then, too, results observed by the inventor for the PRB seem to indicate gas contents that are typically far in excess of those observed. Finally, such techniques provide, at best, an estimate for gas content of the coal and do not provide the practical accuracies desired, neither do these techniques provide an estimate for CDP. Other than the coal sampling-based techniques mentioned above, efforts (e.g., see Koenig, 1988) have included attempts to determine CDP by producing the well and dropping the pressure, perhaps by bailing or by a pump lowered into the well until gas starts being produced. These techniques can be fraught with problems, some of which are: 1) if a pump is used in the well, its capacity may not be sufficient to draw the well down in a practical testing time frame to determine when gas starts being produced; 2) as the liquid level drops in the well, air may be pulled into the casing from the surface, if the casing is open at the surface, because the pressure in the casing will likely be lower than the atmospheric pressure at the surface, or if the casing is isolated from atmospheric pressure (e.g., shut in) a vacuum may be drawn on the well and a negative gauge pressure (in this document gauge pressure will refer to measurement of pressure above atmospheric pressure where zero gauge pressure would correspond to atmospheric pressure) may result until there is sufficient release of gas from the coal to overcome the vacuum being drawn by the falling liquid level; and 3) by the time the pressure is drawn down sufficiently to see gas production at the surface, the reservoir may already be affected by two-phase flow that may lead to complications in interpretation. This can also produce results inconsistent with later production history. SUMMARY OF THE INVENTION Accordingly, broad objects of the invention may include providing techniques and systems to evaluate undersaturated coalbed methane reservoirs and determine particular characteristics of the coal in such reservoirs from other than a sample of the coal itself. Further broad objects may include providing techniques and systems to determine critical desorption pressure of coalbed methane reservoirs and other reservoir characteristics such as characteristics that may be relevant to economic viability or the like. Each of the broad objects of the present invention may be directed to one or more of the various and previously described concerns. Further objects of the present invention may include the characterization and evaluation of undersaturated coalbed methane reservoirs based upon characteristics such as critical desorption pressure, gas content, gas content as calculated from isotherm evaluation, estimates of dewatering for production, and ratios of critical desorption pressure to initial reservoir pressure, among other possible characteristics as presently disclosed. Other objects of the present invention include characterization and evaluation of coalbed methane reservoirs consistent with the techniques presently disclosed and potentially in combination with conventional reservoir analysis, such as coring, logging, reservoir isotherm evaluation, or other techniques. Naturally, further objects, goals, and advantages of the invention are disclosed and clarified throughout this disclosure and in the following written description. To achieve the above-recited objects and the other objects, goals, and advantages of the invention as provided throughout this present disclosure, the present invention may comprise techniques and systems of testing a substance other than the coal or other solid actually of interest in order to inductively quantify a methane content characteristic for sorbed methane in the solid; to understand any factor that bears directly or indirectly on methane content, including but not limited to bubble point, critical desorption pressure, gas-water ratio, or the like. This invention even shows that a test of a characteristic of the formation water, a substance whose characteristics may have been generally thought to be unrelated to the amount of methane sorbed on the solid coal, can be used qualitatively and quantitatively to determine gas content or the like of coal. In addition, the invention shows that the test of the water can even permit inductive quantification of the critical desorption pressure of the coal in an undersaturated coalbed methane reservoir. By inductive quantification, it can be understood that the result is surprising, based on previous knowledge of a person of ordinary skill in the art, in that it is a previously-thought-of-as-being-unrelated-value that yields the desired result. From this method, determinations can be deduced and inferred and the result can be obtained earlier and less expensively than previously done. In some preferred embodiments, the invention includes a method of determining critical desorption pressure of an undersaturated coalbed methane reservoir comprising the steps of: determining a solution gas-water ratio of formation water of the reservoir; determining the bubble point pressure of the formation water corresponding to the solution gas-water ratio; and determining critical desorption pressure of the reservoir from the bubble point pressure of the formation water. In other preferred embodiments, the invention includes a method of determining critical desorption pressure of an undersaturated coalbed methane reservoir comprising the steps of determining the bubble point pressure of the formation water of the reservoir and determining critical desorption pressure of the reservoir from the bubble point pressure of the formation water. To further achieve the above-recited objects and the other objects, goals, and advantages of the invention as provided throughout this present disclosure, the present invention may comprise methods of undersaturated coalbed methane reservoir characterization and characterizing the coalbed methane reservoir from characteristics such as: critical desorption pressure, gas content, gas content as calculated from isotherm evaluation, estimates of dewatering for production, and ratios of critical desorption pressure to initial reservoir pressure, among other possible characteristics as presently disclosed. The invention may also include determinations of critical desorption pressure and characterization of undersaturated coalbed methane reservoirs in combination with conventional reservoir analysis, such as coring, logging, reservoir isotherm evaluation, or other techniques. The present invention teaches that the bubble point of the formation water can be used to inductively quantify the CDP of the coal in the coalbed methane reservoir and that there is no requirement that the formation water remain in contact or carry with it coal as may have been thought necessary. Thus, through embodiments, the CDP of coal in an undersaturated coalbed methane reservoir may be quickly, easily, accurately, and relatively inexpensively determined by the use of one or more CBM wells in an area, and an excellent estimate of gas content can now be made. Further, as mentioned, an estimate of the amount of dewatering necessary to reduce the reservoir pressure from its initial value to the CDP can now be estimated in a practical manner. Importantly, by knowing the CDP in a practical manner, ultimately an economic analysis can now be made of the prospect a priori the drilling of a large number of pilot wells, potentially at tremendous savings in time and investment costs to the operators. Further, by the CDP being known in a practical and more economic manner such as disclosed as part of the present invention, it is now possible to use an isotherm to determine gas content of the coal. Additionally, one can now more practically use an isotherm specifically measured for an area, can use an isotherm determined in accordance with techniques such as core analysis, may use correlations similar to the aforementioned BLM correlations for a given geologic area, or even may (admittedly with less precision) even use very general correlations based on rank of the coal such as are publicly known (Eddy et al, 1982). Finally, through the present invention, one may not even have to use an isotherm at all, but may be able to use the CDP to rank prospects for development in a given geologic area where the variations in gas content may be due to varying degrees of undersaturation. The previously described embodiments of the present invention and other disclosed embodiments are also disclosed in the following written description. The entirety of the present disclosure teaches, among other aspects, a novel and nonobvious method of characterizing, among other things, undersaturated coalbed methane reservoirs of gas-water systems, and other techniques that circumvent many of the problems of timeliness, inaccuracy and expense identified above for other state-of-the art methods. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a relationship between solution gas-water ratio and bubble point pressure such as might be determined in the laboratory at a given temperature and salinity. FIG. 2 shows a statistical fit by cubic equation of measured data-representing the solubility of pure methane in water (mole fraction of methane in the water-rich phase) at a temperature of 100 degrees Fahrenheit with extrapolation to zero mole fraction at zero pressure. FIG. 3 shows the extrapolation at pressures below 600 psia after conversion to units of SCF/STB of the data of FIG. 2. FIG. 4 shows a comparison of three prediction models for the solution gas-water ratio at lower pressures: one based on a theoretical model, one using extrapolation of public data, and one applying a linear extrapolation to publicly available salinity factored data referred to as Hybrid. FIG. 5 shows approximate fits of the Langmuir equation with the statistical uncertainty values for the isotherms determined by the BLM for the PRB. FIG. 6 is a set of publicly available curves that show the relationship between maximum producible methane and depth of coal with rank of the coal as a parameter. FIG. 7 is an isotherm constructed in accordance with the present invention based upon the above curve for subbituminous C coals. FIG. 8 (also referred to as Table 1) is a table of comparisons between gas content determined from desorption of cores and various determinations of gas content from the determination of CDP in accordance with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As summarized above, this invention involves new methods to evaluate a gas-sorbed solid in a practical manner. Although initial applicability is envisioned for methane such as may be contained in solids in commercial quantities such as an undersaturated coalbed methane reservoir, it should be understood that it may be expandable to other solids and other gases in appropriate circumstances. In initial application it involves a situation where a well exists for a reservoir and sampling is accomplished of a substance other than the solid itself from the reservoir. In a preferred embodiment, the substance is the formation water present in the reservoir containing a solid such as coal. This formation water is essentially uncoupled from any contact with the coal and removed from the reservoir containing the solid and is tested in a relatively easy manner to quickly yield information that permits an inductive quantification of some characteristic of the solid in the reservoir. This characteristic may be a methane content characteristic, that is information or data from which aspects relative to or influenced by actual content data for the reservoir can be determined. From the inductively quantified methane content characteristic, some characterization of the reservoir can be accomplished. The invention can be embodied in several different ways and at least some of those envisioned as the best ways to accomplish it are described below. Each feature of the present invention is disclosed in more detail throughout this application, such as in the following written description. In one embodiment, the invention can involve a determination of a solution gas-water ratio for the formation water of the reservoir. When a quantity of gaseous phase is placed in contact with water and well mixed, all or a portion of that gas will go into solution in the water. If all of the gas goes into solution leaving still a single phase of water, the water is said to be undersaturated with respect to the gas. This means that the water can still allow more gas to go into solution if the water were to be placed in contact with an additional quantity of gas and well mixed. At some point, however, the water will become saturated. In theory, the water is said to be saturated when addition of an infinitesimal amount of gas well mixed with undersaturated water will cause the existence of two phases in equilibrium, a gaseous phase and a liquid water phase. The amount of gas that can be held in solution in water is a function of pressure and temperature of the water, components of the gaseous phase, and the amount of impurities in the water (e.g. salt concentration). The pressure at which the water becomes saturated with gas is called the bubble point, so called because this is the unique pressure for a given temperature and fluid composition where the first “bubble” of gas could exist as an independent phase separate from the liquid water. As pressure increases, the amount of gas that can be held in solution in the water increases. Over the range of temperatures typically encountered in CBM reservoirs, the amount of gas that can be held in solution increases very slowly with decreasing temperature. In the course of production of a CBM reservoir, in a specific locality, the only one of these variables that is apt to exhibit major change in the reservoir proper is pressure. However, once the fluids leave the conditions existing in the reservoir, become uncoupled from the reservoir, and start making their way to the surface by any means of conveyance that might be present and through the production facilities, pressure and temperature also change. These changes in pressure and temperature impact not only the amount of gas that can be contained in the water, but also the volume of free gas (i.e. the gas that is not in solution) that may form on the way to the surface. For this reason, it is convenient to represent the amount of solution gas present in a given volume of water at reservoir conditions in terms of relative volumes at standard conditions. This standard is typically atmospheric pressure at sea level (˜14.7 psia) and 60 degrees Fahrenheit. Thus, a common unit for solution gas-water ratio is SCF/STB (standard cubic feet of gas per stock tank barrel of water). There are a variety of ways to determine solution gas-water ratio in accordance with the invention. One method of determining solution gas-water ratio for the formation water is to obtain a bottom-hole sample of undersaturated formation water and determine the solution gas-water ratio and perhaps bubble-point in a laboratory. For the purposes of this invention, a general objective of collecting a bottom-hole sample would be to obtain a representative sample of formation water as a single liquid phase, but containing gas in solution at or near the existing reservoir pressure and temperature. Standards have been written for obtaining bottom-hole samples of undersaturated oil. The goal here is to capture substantially pure formation fluid (that is fluid not tainted or contaminated by drilling fluids or the like) and to assure that the formation water sample obtained is truly representative of that existing naturally in the formation. The methodology employed and described in detail in these standards is directly applicable to the procedure of obtaining a bottom-hole sample of formation water, and thorough treatment and nuances of the methodology can be found in the reference listed as that of American Petroleum Institute, 1966 that would encompass the following abbreviated description. Basically in obtaining an appropriate sample, existing reservoir temperature and pressure may be measured and recorded. In order for the sample to be representative of the formation water, the well should be produced for a period long enough to remove all remnants of foreign fluids introduced during the process of drilling and completion. The pressure should be lowered at the bottom of the hole adjacent to the formation so that reservoir fluids will move from the formation to the wellbore. During this production period, a small drawdown (drawdown is the difference between the reservoir pressure and the bottom-hole producing pressure) is recommended so that the pressure does not drop so low as to go below the bubble point pressure of the formation water during sampling. If the bottom-hole pressure drops below the bubble point pressure of the formation water, two phases may exist when the sample is taken at the bottom of the hole so that capturing the appropriate amount of gas and formation water in the appropriate proportions can become a significant problem. To obtain the sample, the well could continue to be produced at a slow rate or it could be shut-in just prior to sampling depending upon the configuration of the well and sampling equipment. A sampler described in the standards may be lowered in the well to a level typically adjacent to the formation and a sample drawn. The sample may then be remotely sealed to effect contained sampling at the bottom of the hole at or above reservoir pressure, brought to the surface, and transported to the laboratory for analysis commonly referred to in the petroleum industry as PVT (pressure-volume-temperature) analysis. If the well is being pumped or otherwise produced during the sampling of the well, at least one representative sample could even be collected at the surface. This sample could even be tested on site for the particular characteristic of interest. One embodiment of the invention may comprise a fluid control such as a valve at the surface. The valve may be closed during pumping until the pressure upstream of the valve exceeds an estimate of the bubble point of the water, and consequently the CDP of the coal. A reasonable guideline would be to adjust the valve until the pressure upstream of the valve, is at or above the static bottomhole pressure, perhaps after a few days of shut-in prior to obtaining the sample. Placing the pressure ahead of the valve above the static bottomhole pressure could help to assure representative samples, such as to assure that the typically small effect of temperature change from bottomhole conditions to surface conditions would not change the phase relationship from single-to two-phase ahead of the sampler. In this manner, the sample collected upstream of the valve and at the pressure ahead of the valve, may be more representative as single-phase when captured. Samples could then be sent to a laboratory for analysis, potentially after having been adjusted to reservoir temperature. Also, whether or not taking the temperature effect into account and/or other such effects, one could make an approximation of bubble point pressure and/or solution gas-water ratio on site by reducing the pressure on the sample and observing the relative volumes of gas and water at atmospheric pressure such as through a sight glass or by other indicator if the sampler is so equipped. Further on-site expedients to obtain an estimate of the bubble point of the water could include: 1) acoustic detection of two-phase flow by lowering the pressure upstream of the valve until an audible difference is noted between single-phase and two-phase flow with the corresponding value of upstream pressure being an approximation for the bubble point, and 2) by noting the contrast in frictional head loss in going from single- to two-phase flow such as could be accomplished, for example, by measuring the differential pressure drop in a section of the pipe upstream of the valve. If accomplished at a laboratory, a suite of measurements can be made on the sample of undersaturated formation water. Regardless as to where made, testing can include determination of solution gas-water ratio perhaps either by making a single determination by dropping the pressure to some prescribed low pressure, perhaps at approximately zero absolute pressure, and measuring the amount of gas released in the process and dividing this by the volume of water in the sample. In addition, one can test for the solution gas-water ratio at only a prescribed number of pressures so that a solution gas-oil ratio versus absolute pressure curve can be constructed. This option may be preferable because of its broad application as described below with regard to bubble point determination features. In determining the solution gas-water ratio, it is possible to utilize or determine a variety of gas and other factors, including but not limited to the composition of the released or obtained gas (methane, carbon dioxide, etc.), the surface temperature, the surface pressure, the gas remaining dissolved after the test, and to factor these aspects into the test results. It is also possible to utilize or determine the composition of the formation water and to factor these aspects as well into the test. Of importance in this regard can be the effect of salt concentration. It is recommended in some embodiments that the full suite of tests, if made at all, be made only on one or a few wells in a new area of development. The solution gas-water ratio as a function of absolute pressure obtained in the process could then be used to determine the bubble point pressure of the formation water and the CDP of the reservoir as taught here. Some or all of the data conducted on the samples given the full suite of tests can then be applied to other samples and other wells in the new area and this may yield results that are more accurate than the use of general, theoretical or published correlations. Another method that can be used to determine the solution gas-water ratio of the formation water by measurement of produced quantities of gas and water: Although this method may produce results slightly less accurate than results from bottom-hole sampling, when the time and expense of obtaining and analyzing bottom-hole samples is taken into consideration, direct measurement may be the preferred way to determine solution gas-water ratio. As in bottom-hole sampling, it may be desirable that the formation water be a single phase at bottom-hole conditions with the only gas present at bottom-hole conditions adjacent to the formation being that which is in solution in the formation water. Indeed, if it is not single-phase at conditions existing in the coal, then the reservoir is likely saturated and the invention described here may be neither necessary nor applicable. It may not be necessary because if it is known that the coal is saturated, one only need record the existing reservoir pressure (e.g. perhaps by equating the bottom-hole pressure, after sufficient shut-in, to the reservoir pressure). The reservoir pressure (i.e. when two phases exist) would correspond to the current desorption pressure and this fact would be recognized by most skilled in the art. When the formation water is undersaturated—as of interest in the present invention—the reservoir pressure is higher than the bubble point pressure of the formation water. In such a situation, the solution-gas/formation water ratio can be directly measured or tested in accordance with the present invention by testing produced quantities of gas and water. In this embodiment, it is usually desirable to keep the bottom-hole pressure higher than the bubble point. This can be done by producing the well at very small drawdown (the difference between reservoir pressure and bottom-hole producing pressure) so that the bottom-hole producing pressure is kept above the bubble point pressure. Since one does not know a priori the bubble point pressure (indeed that is what is being sought), it can be practical to assume that the bubble point pressure is below the producing bottom-hole pressure and then verify that assumption during the measurement and subsequent estimation of bubble point pressure. After a well is completed, is in communication with the coal formation, and is shut in for a sufficient period to allow the bottom-hole pressure to become the same as the reservoir pressure, one can then measure the pressure of the fluids immediately in contact with the wellhead at the surface. If there is negative gauge pressure (psig) present at the surface, the well is actually drawing a vacuum. This can be caused by: 1) some reduction in reservoir pressure (perhaps by production of nearby wells), or 2) by the bottom-hole pressure being higher than the reservoir pressure (perhaps achieved while drilling) when the well was shut-in before the bottom-hole pressure had a chance to fall off to the reservoir pressure. Regardless of the cause and to use this production method, such a well will have to be produced by artificial means such as by a downhole pump. Such a condition can be taken as strong evidence that the fluid at the bottom of the hole is a single water phase and if fluids there are representative of the formation, therefore, strong evidence that the coal is undersaturated. If the gauge pressure of the fluids in contact with the surface of the shut-in well is zero and if there is communication between the well and the formation, this again may be taken as an indication not only that that the well will most likely have to be produced by artificial means to conduct the test, but that the coal is undersaturated, and that the bottom-hole pressure was equal to formation pressure at shut-in. If the gauge pressure at the surface of the shut-in well is positive, then it may be important to know what fluid is at the surface of the well. This can be accomplished by opening a valve at the surface. When the valve is opened, if the well continues to flow gas, even at a small rate for a long period (perhaps several hours to several days), this may be taken as a good indication that the well is two-phase at bottom-hole conditions and, as explained above, the coal is probably saturated and the shut-in bottom-hole pressure will be at or near the current desorption pressure of the coal. If the well quickly (perhaps less than 15 minutes) quits producing any gas and is not followed by any water production when the valve is opened, then the pressure on the casing could have been caused by some other phenomenon (e.g. the well may have been producing water and the well shut in at the surface before the bottom-hole pressure had a chance to build up to the reservoir pressure). Such a well may have to be produced by artificial means in order to conduct the test. If the well begins to flow or immediately flows only water or mostly water when the valve is opened, then the well will likely flow on its own without artificial means and is called a “flowing” well. More than likely when the casing pressure is accompanied by water at the surface with little or no gas preceding it, the reservoir is undersaturated and the well can be tested and the solution-gas ratio determined directly just by opening the valve and by producing it through separation facilities that will allow the calculation of producing gas-water ratio. On the way to the surface, the pressure in such a situation drops in the fluid from its high at bottom-hole conditions, to its low at the surface at atmospheric pressure. When the transported fluid reaches its bubble point on the way to the surface, gas breaks out of solution and forms an independent phase. More and more gas comes out of solution as the transported fluid reaches lower and lower pressures on its way to the surface. One embodiment of the present invention makes use of the fact that eventually, but usually within minutes, a stable rate can be achieved perhaps with the aid of a choke valve installed at the surface and altering the setting on that valve to alter the production rate. At the surface, the mixture of water and gas may be routed through separation facilities, so that the producing gas-water ratio (i.e., the ratio of produced gas at standard conditions to the volume of water produced) can be directly determined. In such a situation it may be desirable that there be a constant fluid production, that is that the water production rate be held relatively constant during several determinations of the producing gas-water ratio over the course of several hours or perhaps as long as a day. Initial sampling can occur, followed by additional production, and then additional sampling, with comparison of test results or comparing samples. In applying the invention taught here on newly drilled wells, the inventor has found that a good system is to start production on one morning, make a measurement at the end of the workday and come back the next morning or at least longer than a traditional formation water re-sampling time and make another measurement using similar tests to determine accuracy. In this manner, comparing the results of the multiple similar tests can yield an accuracy determination. If the preceding day's producing gas-water ratio is essentially (within the uncertainty of the measurement employed) the same as the one obtained the next morning then the conditions in the formation adjacent to the bottom of the well are single-phase and the value of producing gas-water ratio is approximately equal to solution gas-water ratio of the formation water. In many cases, the determination can be made over the course of several hours, but the inventor has seen at least one case where the measurement did not become constant until the following day. In existing producers that have been under production for some time but are not yet producing commercial quantities of CBM, the results can be obtained very rapidly because presumably all remnants of foreign fluids introduced during drilling would be gone. Of course, the latest measurement should be most representative of the formation water as long as the bottom hole pressure remained above the bubble-point pressure during the course of the test. Any sort of trend in the data with time may be considered troublesome. If there is any sort of trend in the data with time or production rate, either increasing or decreasing with increasing rate, then the bottom-hole producing pressure may have dropped below the bubble-point pressure of the formation water during the test period and the value of producing gas-water ratio may not be fully representative of the solution gas-water ratio. Also, in severe cases of invasion of drilling fluid or stimulation fluid into the formation, the measurement may not be representative of the formation water. If such concerns exist, the production test could be extended over several days until it is possible to achieve a constancy or at least substantially constant producing gas-water ratio or other parameter (e.g., bubble point, CDP, etc) so that the sampling yields a constant result whatever it may be. This inventor has gone back after a week or two of production on several occasions and determined that the same producing gas-water ratio existed as before. One could also utilize on site a chromatograph to analyze the gas coming out of the water during the test to assure that the components measured are consistent with known compositions of CBM in the area. Such consistency would suggest that the test had been run long enough. High values of nitrogen might, for example, suggest that the gas in the water is contaminated by air introduced during drilling or underreaming and a longer period of production might be required to get water entering the pump that is representative of the formation water. As implied from the earlier discussion, when the gauge pressure of the fluids at the surface is either negative or zero, the well will not flow on its own volition and some type of production equipment may be required to perform the test. Production equipment can vary tremendously regarding the types of pumps and well configurations for those pumps, but in this document, only one example will be given as the various pumps and pump configurations are generally known in the industry. This should not be viewed as limiting, however. In many geological basins including the Powder River Basin, a submersible pump is lowered on the end of production tubing to the approximate depth of the coal formation. In some applications, no packer is used to isolate the producing zone from the annular volume in the well above the packer. When there is no packer, frequently the wellbore, either as created by the original drilling process or enlarged by other means, is used as a bottom-hole separator where it is intended that, once gas begins to flow as an independent phase, most of the gas will be forced by buoyancy up the annulus between the tubing and casing, allowing water and a typically insignificant amount of gas to flow up the tubing. The gas that flows up the annulus is often gathered at the surface and sold. The small amount of gas that comes from the tubing is, however, typically vented and not captured. This configuration can be used to determine the producing gas-water ratio and ultimately the solution gas-water ratio. For the purposes of this determination, it may be beneficial to locate the pump close to the formation on the end of a tubing string for two reasons: 1) A lesser amount of water needs to be removed to start retrieving fluids representative of the formation water than if the pump was located farther up the hole, and 2) more importantly, the pressure can be maintained high enough to exceed the bubble-point pressure of the formation water before entering the pump. In accordance with one embodiment, the pump may be turned on at a practical, but relatively slow rate with limited drawdown in an effort to keep the bottom-hole pressure above the bubble point pressure at the bottom of the hole during the course of the test. The water production rate may then be stabilized. When the water production rate no longer requires frequent adjustment, then the measurements may begin. Alternatively and preferably, a pressure transducer can be installed above the pump so that the fluid level can be observed during the test. In this embodiment, when the fluid level does not change significantly, then the measurements may begin. With the fluid level relatively constant in the well, fluids entering the pump will be largely those coming from the formation and not fluids that might not be representative of the formation that could be pulled into the pump from the annular volume between the tubing and the casing above the formation. Alternatively, a packer could be set to isolate the fluids in the annulus above the pump from the fluids below the pump. The water then enters the tubing at the bottom of the hole as a single water phase. At this point the test proceeds in essentially the same manner as that described at above for a flowing well, with the same attempts to make the direct measurement indeed be one of a sample that is representative of the virgin formation water. As in the case of a flowing well, the produced fluids or a portion of the produced fluids are taken to separation facilities where an accurate determination of producing gas-water ratio can be made. Several measurements of producing gas-water ratio can be made; and in some embodiments should be made over the course of hours, a day, or even a week as discussed above for the flowing well case. As before, if any sort of trend is evident in the data with time or rate, or if the producing gas-water ratio does not approach some constant value, there is a chance that the measured producing gas-water ratio will not be representative of the solution gas-water ratio of the formation water and consequently, the value of CDP ultimately obtained may not be accurate. Sometimes the well will be so severely damaged or the permeability of the formation so low that the pump cannot operate at such a low rate to keep the fluid level constant. An option in accordance with an embodiment of the present invention may be to pump off the well, in essence permitting an inappropriately low pressure and producing substantially all of an initial well volume, and then allow the well to rebuild pressure, to refill over the required time (perhaps several days) to at or near its original fluid level. The well can then be produced, and once one well or well pathway volume above the pump has been produced in some embodiments, sampling may commence. It may be preferable to sample before the fluid level drops too low to be representative. These first sampled fluids, collected after the displacement of one tubing volume, are more likely to be representative of the formation fluid under adverse situations such as a tight reservoir and/or severe well damage. Conducting the test in this manner cannot be expected to yield results as what could be achieved with a longer test, but it may allow salvaging a test that might otherwise be aborted. Other methods of determining solution gas-water ratio may also be used in various other embodiments of the present invention. Any method of determining the solution gas-water ratio would be consistent with the features taught of the present invention and is a relevant step in combination with other features and in application of the invention. These may range from low-tech systems and techniques to more advanced methods perhaps even including the separation and pressure measurement methods of the Gray patent reference where one releases a limited amount of pressure and observes a pressure buildup. For example, it is also possible that a representative sample of formation water could be obtained through the drill stem in a procedure that would fall under the general category of drill stem testing as discussed by the Earlougher reference, 1977. Drill stem testing is a way of temporarily completing a well during the process of drilling so that evaluations of the formation and formation fluids can be made without the expense of completing and casing a well. In drill stem testing, a tool is often lowered into the hole at the end of the drill pipe, the zone of interest is isolated by formation packers and the drill pipe is used to transport fluids from the formation to the drill stem and these fluids can be sampled and analyzed for fluid properties. With the caveat that precautions should be taken to assure that any sample of formation water is truly representative samples obtained through the drill stem sampling technique can be used in embodiments of the present invention. If adequate pressure exists, then the well could be flowed at the surface, and determining the solution gas-water ratio could be determined as described above for the case where a positive fluid pressure exists at the surface. Optionally, a pump could be run in on the drill string or on tubing by the drlling rig and a test could be conducted in a manner similar to the techniques described here. This would have the advantage of obtaining immediate results, but the disadvantage of having to pay rig time while the test was being conducted. As another technique, at least one company, Welldog, Inc., is aspiring to come up with means of determining the gas content of the coal formation by a tool for which a patent application has been filed. While this tool is designed to specifically determine the CBM content of coals, presumably it, or a similar device based on the same concept, might also be used to obtain and test formation water and to then achieve the present invention. As yet another example, it might also be possible to locate the pump higher up in the hole, at a location remote from the reservoir, instead of adjacent to the formation in the situation where a pump is installed to test the well as described above. This situation might result in an accurate assessment depending upon how low the bubble point of the formation water actually was. If gas begins to come out of solution below the pump, however, the results could be very hard to interpret as part of the gas could go up the annulus and part would go through the pump. The gases from both the production tubing and the tubing-casing annulus could also be combined at the surface to effect a contained sampling of both the formation water and the gas, essentially the total gas content of the water. Solubilized and desolubilized methane can be captured to effect an accurate determination. These two can then be measured through separation equipment. As long as the bottom-hole pressure at the well bottom remains above or at least at the bubble point of the formation water, and no phase separation is permitted at this location, this recombination of gases and measuring of the production rate of the recombined amount divided by the production rate of the water could lead to a reasonable value for solution gas-water ratio by equating it to the producing gas-water ratio. Interpretation could be complicated by not knowing for certain that the bottom-hole pressure was above the bubble point of the formation water. As previously mentioned, if the reservoir pressure drops below the bubble point pressure of the formation water, the results could be impacted by potential two-phase flow in the formation that could lead to producing gas-water ratios that might not be representative of the solution gas-water ratio for the formation water. It is also possible that one might note when gas first starts being produced from the casing-tubing annulus when production tubing and pump are installed in the well. One could then place a backpressure on the well at the surface and consequently raise the bottomhole producing pressure. If the bottom-hole pressure rises to a level that would be above the bubble point of the formation water at bottom-hole conditions, the gas would go back into solution and flow from the casing-tubing annulus would cease with the desirable result that the fluids at the bottom of the hole would be a single phase. This could lead to a fairly accurate estimate of solution gas-water ratio as determined from the producing gas-water ratio with the risk that the re-solution of the gas in the water may be in proportions not representative of the formation water. As mentioned above, direct measurement of solution gas-water ratios can involve separation and volumetric testing of the gas and water. The separation facilities through which the produced fluids may be passed can be any convenient facilities. Several separation facilities are considered in a document prepared by the Michigan Department of Public Health (Keech and Gaber, 1982) hereby incorporated by reference. The facilities can include those that are commercially available that are normally used for the surface separation of reservoir fluids in the oil industry or perhaps modified to measure quantities of fluids more precisely. If such facilities are not in place, they may not be convenient because of the logistics of moving them from one place to another perhaps because of their large size, etc. Facilities that may be convenient include: a bubble-pail device and a separation barrel device. The bubble-pail device is discussed by Keech and Gaber, 1982. Simply stated, the bubble pail may be any suitable container (e.g., a five-gallon bucket) through which a riser pipe may be mounted with a stand located some distance down on the riser pipe and attached to it. At the top of the bucket may be located an outlet. The produced fluids from the well or a portion of them may be routed through the riser pipe and allowed to fill the bucket so that water is flowing from the outlet on the top of the bucket. Valves can be adjusted upstream to achieve a manageable rate of flow through the bucket and that rate can be determined by collecting a known volume of water flowing from the bucket over a given period of time. Once the rate has stabilized through the bucket, a calibrated, open-ended transparent vessel may be filled with water and inverted so that the vessel remains completely filled with water with no air or gas pockets at the top (actually after inversion the bottom of the vessel becomes the top). To make a measurement, simultaneously, the inverted gas-collection vessel is moved over the top of the riser pipe and held in place resting on the stand and a container is placed under the outlet of the bucket. Gas floats to the top of the vessel and water goes out the opening of the vessel and into the bucket. At some convenient point, both the vessel and the container may be withdrawn perhaps simultaneously. By measuring the amount of water in the container and the amount of gas in the vessel, an estimate of producing gas-water ratio can be made by dividing the amount of gas in the vessel by the amount of water in the container and converting everything to standard conditions. Although it is preferable, where possible, to route the entire produced volume through the pail, it is not always possible, so a partial stream can be diverted through it. Generally, the results from a partial stream and a full stream are consistent, but the inventor has observed that on occasion, the results are somewhat different. So, a full stream through the bucket may be recommended. The other facility that may be convenient is a separation barrel with orifice flow tester and water meter. This is a more robust, but somewhat less transportable, separator that can be constructed from a 55-gallon drum. Again a riser pipe through which the produced fluids will flow may be mounted and sealed so that the top of the riser pipe is located about halfway to the top of the drum. A sight glass may be installed so that the level of fluid coming into the drum can be maintained constant by controlling a drain valve located near the bottom of the drum. At the top, an orifice well tester may be located in the opening of the drum. Conditions may be allowed to stabilize and then the water rate may be determined by any means (e.g. flow meters, measured volumes per unit of time), and the gas rate may be determined through the orifice well tester. The ratio of the gas rate to the water rate may then be converted to standard conditions giving the producing gas-water ratio. Regardless of the separation facility employed, it may or may not be desirable to account for the amount of gas remaining in solution in the water at atmospheric conditions. It may be desirable if extreme accuracy is desired or warranted or at very low bubble points approaching atmospheric pressure. Usually, the amount of solution gas contained in water is represented as a function of absolute pressure. The solution gas-water ratio of this remaining gas can be added to the value determined above, if deemed significant in any application before the next step is performed. If this is done, temperature of the water in the separator and atmospheric pressure may also be recorded at the site of the measurement. The value of this small amount of remaining gas can then be estimated using measured data from a laboratory, Henry's law, or correlations as are discussed throughout this document and particularly in the written description below. In most applications adding in this small amount of gas remaining in solution at atmospheric conditions, while theoretically important, may not be practically important and may beg the accuracy. In another embodiment, the invention can involve a determination of the bubble point pressure for the formation water of the reservoir. In the event that a bottom-hole sample of formation water is collected and analyzed and if part of the analysis was to determine the bubble point pressure of the formation water at formation temperature and pressure, then for the specific well from which the bottom-hole sample was taken, an embodiment of the present invention may skip determining the solution gas-water ratio and may go directly to determining CDP from the bubble point value. In fact the present invention has discovered that the value of the bubble point pressure of the formation water can be equated to the CDP of the coal. The bubble point pressure of the formation water can also be estimated by a variety of techniques in accordance with the present invention. If a bottom-hole sample was collected and analyzed, and if the solution gas-water ratio as a function of absolute pressure was obtained as part of the analysis, then the bubble-point pressure of the formation water can be determined by finding the inverse of the functional relationship, with the estimate of solution gas-water ratio as previously described. Mathematically, this can be expressed as, bp=f1(Rsw), where bp is bubble point pressure of the formation water and Rsw is the solution gas-water ratio. More practically, one can find the bubble point pressure of the formation water from the point on the horizontal axis (bubble point pressure) corresponding to the point where the value of the determined solution gas-water ratio intersects a curve drawn through the experimentally measured data. Anticipated curve shapes can also be used. FIG. 1 shows a fictitious relationship between solution gas-water ratio and bubble point pressure such as might be determined in the laboratory at a given temperature and salinity. One enters the vertical axis at a point (arbitrarily shown as [1]) with the solution gas-water ratio, goes horizontally until one reaches point [2], the intersection point with the curve, and then moves vertically downward to determine the corresponding bubble point pressure of the formation water at point [3]. In doing so, one is implicitly assuming that the water to which a solution gas-water ratio is determined is not appreciably dissimilar from the water analyzed in the laboratory (e.g., same temperature with similar salt concentration, gas composition, etc.). In most cases, this will be a reasonable assumption over fairly large geographical areas within a certain formation in a given geological province. If it is believed that this assumption is not being met, then one risks some accuracy. In such cases, one could have additional samples taken and analyzed. As a somewhat less accurate alternative, water samples from nearby producing wells can be quite easily obtained and sent to a laboratory where a relatively inexpensive and routine analysis can yield salt concentration in the water. In many instances, such measurements are required by state agencies anyway, so the data may be as close as the well file. Also, temperatures of the formations can be readily obtained for a given area from correlations with depth using an appropriate geothermal gradient or by direct measurement. Knowing this range of salt concentrations and temperatures, one could request that the laboratory prepare a family of curves similar to FIG. 1 using this range as bounding values. Then, one could determine the bubble-point pressure by using the appropriate curve or interpolated value between bounding curves corresponding to the temperature of the formation and salt concentration of the formation water from the well for which the bubble point pressure is desired. While the laboratory-derived curve(s) as discussed in the preceding technique has (have) the advantage of using gases that may be close to the composition of the gas contained in solution of any reservoir of interest and while the formation water can have the correct salinity factors, obtaining such samples and analyses can require time and additional expense. Taking this into consideration and realizing that CBM is mostly methane, probably the preferred technique of determining bubble-point pressure of the formation water is to assume that the gas is all methane and to use existing correlations if reservoir temperatures and pressures are within the specified ranges of the correlation. If reservoir temperatures and pressures are outside of the ranges of the correlation, then according to the present invention extrapolated values of fits to these existing correlations can be used. These correlations are quite prevalent in the literature. For a fairly complete review of these correlations, see Whitson and Brule, 2000, Chapter 9. Two such correlations are particularly appropriate to some embodiments of the present invention: the McCain correlation (McCain, 1991, Equations 52-56) and the Amirijafari and Campbell correlation (Amirijafari and Campbell, 1972). The McCain correlation fits an original graphical and frequently referenced correlation (see Culberson and McKetta, 1951) with a quadratic equation as a function of absolute pressure and with coefficients that are functions of temperature in degrees Fahrenheit. The correlation is believed accurate to within 5% for the graphical values over pressures from 1,000 psia to 10,000 psia and temperatures from 100 to 340 degrees Fahrenheit. Lending to the nonobvious character if the present invention, McCain himself states that the correlation should not be used for pressures below 1000 psia. Noteworthy is the fact that McCain also provides an equation (Equation 57) that takes into consideration salinity of the formation water. In general, solution-gas decreases with increasing salinity. Whether use with or without the salinity factor, the present invention shows that the McCain correlation can in fact be used in conjunction with or as part of the present invention to achieve the evaluation even though at pressures outside of the recommended range. The second correlation that can be beneficially used is that of Amirijafari and Campbell (Amirijafari and Campbell, 1972). This includes data at a somewhat lower pressure, but still not at the pressures low enough to address the needs of the present invention. FIG. 2 shows a plot derived from individual data points presented by Amirijafari and Campbell. This data represents the solubility of pure methane in water (mole fraction of methane in the water-rich phase) at a temperature of 100 degrees Fahrenheit and for pressures between 600 and 5000 psia. In accordance with the present invention, a curve has been generated through the data that is a statistical fit by a cubic equation as a function of pressure with the intercept forced to be zero (the equation and goodness of fit are shown in FIG. 2). Since this data begins at 600 psia, use of this correlation also involves extrapolation beyond the values of the data presented. One such extrapolation is shown in FIG. 3 with conversion of mole fraction to units of SCF/STB as supported by the reference to Whitson and Brule, 2000. The significance of the extrapolation can be understood by the fact that in the Powder River Basin, where the invention taught here has been reduced to practice, all bubble points estimated by the invention were below 600 psia. The extrapolation, therefore, has been used and is valuable to estimate the bubble point of the formation water. While normally one extrapolates data outside of its measured range at some risk to accuracy, the invention involves techniques that can reduce the potential inaccuracies of an extrapolation. In embodiments, it may involve the technique of utilizing an expected zero crossing point where, at an absolute pressure of zero, no methane is assumed to remain in solution. It can be noted that by forcing the curve to go through zero-zero, the fit of the curve through the measured points is excellent (See FIG. 2). In addition, there are theoretical methods that can to some degree corroborate the results shown here. Actual data also shows that this embodiment is fairly accurate. In the Powder River Basin this embodiment has been tested in several wells by the inventor exclusively using the extrapolation in spite of the fact that it is outside the range of the measured data, in spite of the fact that the temperatures of the reservoir are typically less than 100 degrees Fahrenheit, in spite of the fact that the formation waters of the PRB are not completely fresh, and in spite of the fact that the gas composition is not entirely methane. In the wells where the reservoir pressure has now dropped to a level where commercial quantities of CBM are now being produced, using the bubble point determined in this manner has resulted in a reliable prediction of CDP. Also, in wells using this technique of bubble point testing in determining CDP, and, in turn, using the determined CDP to estimate gas content has provided a reliable estimate of the gas content of the coal in wells where gas content was measured on cores according to the more expensive and time consuming prior techniques. A third method of correlation that can be beneficially used is that of theoretical techniques. Estimates of solubility of gas in water for dilute solutions can be determined by theoretical methods. These are also discussed in the reference to Whitson and Brule, 2000 hereby incorporated by reference. FIG. 4 shows the comparison of the solution gas-water ratio predicted by one of these methods, a theoretical methods based on Henry's Law, with the extrapolation of the fit to publicly available data (an Amirijafari and Campbell correlation) and a hybrid method discussed below. The closeness of the curve generated by Henry's Law and the curve from the extrapolation of Amirijafari's and Campbell's data is quite remarkable at pressures below 500 psia—pressures previously thought to be outside the usable range of the data. Note that as pressure increases, the solution becomes less dilute and the theoretical prediction resulting from Henry's law eventually begins to deviate significantly from the measured data. This is consistent with the theory of Henry's law. But in areas of lower pressures, regions where the predicted CDP's fall below 500 psia, this method may have the most utility of all. In fact its value may be understood by the facts that Henry's Law is simple to apply and the fact that Henry's Law constants are readily available in the literature for a wide range of temperatures (e.g., Perry and Green, 1997). When theoretical methods such as these are employed, one can even reduce gas content calculations to a single equation as a function of the solution gas-water ratio as determined above. For example, through the present invention and for a given temperature, one could obtain, by interpolation if need be, the appropriate Henry's law constant, adjust this constant to the appropriate units, solve for pressure as a function of solution gas-water ratio and then substitute this expression into the Langmuir equation resulting in an expression relating gas content directly calculable as a function of one variable, the solution gas-water ratio. Yet another embodiment may involve the use of an approximate correlation. In particular, it should be understood that any combination of the above theoretical and empirical correlations could be used. For example, Henry's Law may be viewed as resulting in a straight line relationship between solution gas-water ratio and absolute pressure and McCain's correlation may be understood as valid only as low as 1000 psia, it can also be understood that these may not take into account salinity. Even in a salinity based correlation, the inventive technique of utilizing an expected zero crossing point where, at an absolute pressure of zero, no methane is assumed to remain in solution can be applied with success. Specifically, if salinity is deemed an important consideration, one could combine these ideas by evaluating the McCain correlation adjusted for salinity at the edge of the range of applicability of the correlation and then use an equation of a straight line connecting this point running through the origin. Applying this procedure with a salinity of zero results in the curve such as shown in FIG. 4 and identified in the legend as the “Hybrid (McCain endpoint)” method. This, too, can be used in embodiments of the present invention. A significant aspect of the present invention is its realization that the bubble point pressure of an entirely different substance, namely the formation water, can be used to inductively quantify the critical desorption pressure of the coal. As discussed above, there appears to be no clear recognition that the bubble point pressure of the formation water can be equated to and is the same as the critical desorption pressure of the coal. Perhaps surprisingly, the present inventor has demonstrated that the bubble point pressure of the formation water is the critical desorption pressure of the coal. This fundamental realization permits the easy determination of the CDP and its use several applications of much value. Perhaps of most economic importance, by the highly simplified determination of CDP, gas content can be more easily determined. One of the most valuable applications is to determine CDP by the invention as taught here and then use the value obtained to estimate gas content of the coal. In one embodiment, this gas content can be estimated by using publicly available, predetermined isotherm data. In most coals where CBM deposits are of commercial interest, some evaluation of the deposits has been performed by government agencies holding interest in the deposits. As part of that evaluation, gas contents and isotherms are usually measured and available to the public. As mentioned above, such is the case in the PRB where the BLM has constructed an average synthesized isotherm from isotherms measured on some 40 samples. FIG. 5, prepared by the inventor, shows approximate fits of the Langmuir equation to the isotherms determined by the BLM. The Langmuir equations were found by extracting two points from the curves and determining the Langmuir volume and pressure by algebra. To obtain an estimate of expected gas content using this embodiment, one may simply enter the curve with the CDP on the horizontal curve and determine the value of the gas content from the vertical axis corresponding to the value of CDP from the middle curve, i.e. GC=f(CDP), where GC is gas content. Also, as alluded to above, the BLM has reflected in their figures the uncertainty associated with the data by showing the curves representative of one standard deviation above and below the mean. These have also been approximately fit by using two points by the inventor with the Langmuir equation. From the curves, it is obvious that as the CDP becomes smaller the absolute error becomes smaller so that at very low CDP's, one can even expect, with very little risk, that little gas will be ultimately recoverable. So, if a low CDP, close to zero, is determined by the invention taught here, the prospect for gas recovery from the coal may be viewed as almost nil. For example, using the BLM average isotherm with the CDP determined by the invention taught here and using the Amirijafari and Campbell curve in FIG. 4 resulted in estimates of gas contents for two wells in the PRB of 5.2 and 8.1 SCF/Ton. For the conditions in these wells (including high initial reservoir pressure and low CDP implying long dewatering periods), such values show rather easily that these two wells are not likely prospects for commercial CBM production. In another embodiment, this gas content can also be estimated by using correlations based on rank of coal using coal-type ranked data. A published set of curves such as shown in FIG. 6 that show the relationship between maximum producible methane and depth of coal with rank of the coal as a parameter can be used in this embodiment (see Eddy et al, 1982). As a first approximation, one could convert these curves to functions of absolute pressure by assuming a fresh-water, hydrostatic gradient (0.433 psi/ft), multiplying this number by the depth, and by adding atmospheric pressure to the result. As such, these would then represent an inexpensive isotherm that could be used to estimate gas content if the rank of the coal is known. For example, in the PRB, the gas-containing coal is predominantly, if not exclusively, subbituminous in rank. Constructing an isotherm according to the present invention with use of Eddy's curve for subbituminous C coals results in FIG. 7. In practice, the plot in FIG. 7 was constructed by pulling two points off the graph of FIG. 6, converting the abscissa to psia and determining the Langmuir volume and pressure from simultaneous solution of the equation of these two unknowns. Making this embodiment less intuitive is the fact that the plot of FIG. 6, as will be noted, for such low gas-content coals could result in highly subjective interpretations. With no particular attempt to fit the data, however, the gas contents resulting from the use of this isotherm embodiment and the invention embodiment turned out to be 13.7 and 18.7 SCF/ton—which compare respectively to the ones determined in the preceding paragraph. While the two sources of isotherms may appear to give results that are significantly different, in the PRB where the range of gas contents can be 0 to 100+SCF/ton, both of these results would likely result in the same conclusion, i.e. that the coals in these wells have gas contents on the low end of the range for the PRB. Also, it can be noted that the approach using coal rank to generate the isotherm will also allow one to make the conclusion that the second coal is relatively better than the first and this could be valuable to know as explained next. In yet a further embodiment, merely relative gas content can be estimated even if the only thing that is known in a given area is an approximate gas content at a given pressure, in such an embodiment, a fictitious isotherm could be constructed just by sketching in an arbitrary shape, with use of the technique of going through the given pressure and the origin of zero gas content at zero absolute pressure. For example, a source for such data might be a well where gas contents had been measured in a laboratory, but the operator may not have requested that an isotherm be measured as part of the laboratory measurements. Associating the measured gas content with the CDP determined by the invention taught here could help in defining the fictitious isotherm with increased accuracy by requiring it to go through this one measured point. Carrying this approach one step further, if there happened to be yet another well in close proximity where another gas content measurement had been determined and also a CDP determination made by the invention taught here, then, if the gas content and CDP were uniquely different from the first, one could construct an isotherm that could conceivably be better than the one determined with only a single point. In some embodiments, two non-zero points may be all that are required to adequately define an isotherm. In these manners, determining CDP for a number of exploratory wells in a given geologic area by the invention taught here and estimating the gas content using the fictitious isotherm could then provide a relative ranking of prospects for development with those having the highest gas contents having the highest rank. Similarly, even without any gas contents measured at all, if the CDP's were measured on a number of exploratory wells using the invention taught here in a given geologic area, just arranging the measured CDP's in order of highest to lowest CDP could give a working list of developmental prospects with those having the highest CDP's being developed first. Table 1 shows a number of comparisons between the uses of the various techniques of determining gas contents using the methodology discussed above and the invention taught here to determine CDP. Merely as a point of reference, Table 1 also shows results from gas contents determined from cores for the two wells in the PRB. As discussed above, the core-measured data should not necessarily be regarded as the truth because of the inherent problems associated with its estimation. Nevertheless, the results show that the invention as taught here can provide remarkable consistency with measured data from cores but at a drastically reduced expense—particularly when data, like the BLM data is available for a given region. As mentioned, at higher CDP's the error in the approximation for gas content may increase. In spite of this, the inventor has noted, however, that the predicted CDP at higher resulting values of CDP using the invention taught here and the BLM average curve was an accurate predictor of the reservoir pressure when the wells subsequently started producing gas. Gas contents determined by using the average BLM isotherm and the invention taught here to determine CDP's have resulted in estimates of gas contents from zero to 60 SCF/ton in about 20 wells where the method has been applied. As should be understood from the above, the embodiments relative to the characterization of the reservoir or even the determination of gas content in accordance with the present invention can be highly varied. One may simply involve a prediction of how much drop in reservoir pressure is likely to be required by dewatering before gas is produced. Once the CDP is estimated by the invention taught here and with a measurement of initial pressure of the reservoir, an estimate can be determined of how much water must be produced before commercial quantities of gas can be produced, an estimated dewatering value. This may be done by approximate reservoir engineering calculations, or in more sophisticated calculations, by a reservoir simulator. Obviously having to dewater for long periods of time without producing any gas can be a major detriment to positive economics of any project under consideration. Another embodiment may involve a determination of current saturation character or saturation state of a coal used for gas storage or sequestration of harmful greenhouse gases like carbon dioxide. By using the invention taught here and an isotherm or multi-component isotherm representative of the gas(es) being stored or sequestered in an undersaturated coal, one could estimate the current saturation state of the coal. This could be valuable so that an estimate could be made as to when the storage reservoir would effectively be filled up (i.e. when it would become saturated). Similarly the invention as taught here could be used in determining the saturation state of the formation after a period of injection of displacing gases such as are used in Enhanced Coalbed Methane (ECBM) recovery processes (Puri and Stein, 1989). Challenging situations can also be addressed in some embodiments. For example, in reservoirs with low permeability or low permeability wells, an issue may arise respective of produced wells. In the immediate vicinity of the wellbore, the reservoir pressure could be very low from producing at low bottom hole pressure. The reservoir pressure usually increases very rapidly away from the wellbore due to the typical pressure profile associated with radial flow. It is possible that a portion of the reservoir near the well could have been drawn below a CDP of the coal, for a period long enough to de-gas to a certain degree. Detecting when de-gassing is occurring may be desirable and, if not adequately accounted for, can be missed. In time, de-gassing could deplete the coal in the immediate vicinity of the well. If the well is shut-in long enough for the water and the coal to equilibrate, a determined CDP may be artificially low. The determined CDP may not be representative of the CDP of the bulk of the coal some distance away from the wellbore. With time, natural or induced groundwater flow may resaturate the coal to at or near a CDP, such as a CDP prior to production; but if, for example, the formation is ‘tight’ so as to prevent much groundwater flow, such as may be due to typically small gradients, and also if the period of shut-in is long, then a measured CDP may not be representative of the CDP of the coal of the reservoir, as may be the case when the well is returned to production potentially for testing. Embodiments of the present invention may be use to address unrepresentative CDP determinations. Accordingly, as features of some embodiments, producing a well at small drawdown for a period of time (perhaps a week, or a producing period that may be otherwise longer than a traditionally expected production) after a period of quiescence or non-production may be used. Water coming from the bulk of the formation will likely be moving rapidly through the volume immediately next to the wellbore and what little CBM that may be lost to the highly undersaturated coal immediately near the wellbore may not significantly impact the determinations of the present invention and may even be ignored. Eventually, the coal near the wellbore will resaturate to at or near an original CDP allowing equilibrium methane conditions to be established at the well bottom; but in accordance with the present invention, it may not be necessary to wait until full resaturation occurs before testing. Furthermore, and if desired, several tests could be conducted with time until the CDP stops increasing and in a manner that affirmatively allows pressure to rebuild, not mere have it happen incidentally. Yet another embodiment relative to the characterization of the reservoir in accordance with the present invention may be the determination of the economic viability of continuing to produce water from existing producers, more generally the inclusion of an economic factor in the characterization. Many existing production wells have been producing water for years with the operators not knowing whether these wells will ever produce economic quantities of CBM. Threshold values or, more generally, screening criteria can be used that incorporate a variety of concerns into an economic viability or other analysis, including individually or in concert, but not limited to: a screening criterion based upon a reservoir pressure, a screening criterion based upon a permeability of the reservoir, a screening criterion based upon the apparent critical desorption pressure of coal in the reservoir, a screening criterion based upon the estimated dewatering needs of the reservoir, a screening criterion based upon the degree of undersaturation of the coal in the reservoir, a screening criterion based upon current or projected prices of gas, and even a set value of gas content. These may also be particularly suited to computer analysis or automated modalities and may be used not just for producers, but for leaseholders, bankers or other persons interested in the productive capabilities or in the valuation of a particular property. The invention taught here can also be used with existing producers that have yet to produce commercial quantities of CBM. In one embodiment of the present invention, a single production test of the well can be accomplished in usually less than one day and immediately if the well has been produced for some period ahead of testing (e.g. a producing well where the pressure of the reservoir has not dropped below the CDP). Typically, in a new well, one day is sufficient for the well to displace foreign fluids introduced during drilling and completion and to produce a stream of water representative of the formation water, but if not, the well can be run until the solution gas-water ratio becomes relatively constant with repeated measurements. Thus, the invention may lead to a quicker determination of CDP than could be obtained from coring methods and analysis. In turn, the CDP obtained by applying the invention taught here can be used in conjunction with representative isotherms of the area being investigated to make an accurate and quick determination of gas content of the coal relative to the months that coring and core analysis might take to arrive at the same result. In applying the present invention, it may be noted that results may even be more objectively reliable than a localized testing methodology such as coal sampling since the mixing of the formation water surrounding adjacent coals tends to average out differences normally observed in results obtained by sample selection during coring and removes the subjectivity associated with sample selection in core analysis. The results may also be more reliable because the formation water is coming primarily from the same coal that will ultimately be the gas-productive coal. In addition, the present invention can address the problem identified above where multiple wells must be drilled in a pilot. This can even be eliminated because when the invention taught here is employed, the same information can be obtained from a short test from a single well or short tests of a few wells thus eliminating millions of dollars in development costs and months, in some cases years, of attempts at dewatering to bring the reservoir pressure below its CDP so that gas can be produced in commercial quantities and a determination made of the value of the resource. When the invention taught here is employed, a good estimate can be made of the existing gas content of the reservoir thus allowing an economic evaluation of the coal immediately after the well is drilled or, in one application, even while the well is being drilled and an informed decision can be made regarding whether additional development wells should be drilled. When the invention taught here is used, one may not have to worry about the state of equilibrium of the fluids in the borehole because the invention taught here can provide a way of checking to see if the fluid being tested is representative of formation water. Additionally it should be understood that any of the above methods can be embodied and encoded in a computer program to further simplify and to some degree even automate the evaluation methods employed. It also may comprise a sampling apparatus performing any or all of the above aspects as well as the products produced by any or all of these aspects. As can be easily understood from the foregoing, the basic concepts of the present invention may be embodied in a variety of ways. It involves both determination, evaluation, and characterization techniques as well as systems, plurality of apparatus, assemblies, and devices to accomplish the appropriate determination, evaluation, and characterization. In this application, the techniques are disclosed as part of the results shown to be achieved by the various methods. Devices may be encompassed that perform any of these as well. While some methods are disclosed, it should be understood that these may be accomplished by certain devices and can also be varied in a number of ways. Importantly, as to all of the foregoing, all of these facets should be understood to be encompassed by this disclosure. The discussion included in patent is intended to serve as a basic description. The reader should be aware that the specific discussion may not explicitly describe all embodiments possible; many alternatives are implicit. It also may not fully explain the broad nature of the invention and may not explicitly show how each feature or element can actually be representative of a broader function or of a great variety of alternative or equivalent elements. Again, these are implicitly included in this disclosure. Where the invention is described in method-oriented terminology, each step may be performed by a device, component, or element. Apparatus claims may also be included for the methods described. Neither the description nor the terminology is intended to limit the scope of the claims that will be included in a full patent application. It should also be understood that a variety of changes may be made without departing from the essence of the invention. Such changes are also implicitly included in the description. They still fall within the scope of this invention. It should be understood that this disclosure is intended to yield a patent covering numerous aspects of the invention both independently and as an overall system and in both method and apparatus modes. Further, each of the various elements of the invention and claims may also be achieved in a variety of manners. This disclosure should be understood to encompass each such variation, be it a variation of an embodiment of any apparatus embodiment, a method or process embodiment, or even merely a variation of any element of these. Particularly, it should be understood that as the disclosure relates to elements of the invention, the words for each element may be expressed by equivalent apparatus terms or method terms—even if only the function or result is the same. Such equivalent, broader, or even more generic terms should be considered to be encompassed in the description of each element or action. Such terms can be substituted where desired to make explicit the implicitly broad coverage to which this invention is entitled. It should be understood that all actions may be expressed as a means for taking that action or as an element which causes that action. Similarly, each physical element disclosed should be understood to encompass a disclosure of the action which that physical element facilitates. Regarding this last aspect, as but one example, the disclosure of “separation facilities” should be understood to encompass disclosure of the act of “separating”—whether explicitly discussed or not—and, conversely, where there is disclosure of the act of “separating”, such a disclosure should be understood to encompass disclosure of a “separation facility” and even a “means for separating.” Such changes and alternative terms are to be understood to be explicitly included in the description. Any patents, publications, or other references mentioned in this application for patent are hereby incorporated by reference. In addition, as to each term used it should be understood that unless its utilization in this application is inconsistent with such interpretation, common dictionary definitions should be understood as incorporated for each term and all definitions, alternative terms, and synonyms such as contained in the Random House Webster's Unabridged Dictionary, second edition are hereby incorporated by reference. Finally, all references listed in the Information Disclosure Statement or other information statement filed with the application are hereby appended and hereby incorporated by reference; however, as to each of the above, to the extent that such information or statements incorporated by reference might be considered inconsistent with the patenting of this/these invention(s), such statements are expressly not to be considered as made by the applicant(s). Thus, the applicant should be understood to have support to claim at least: i) each of the determination, characterization, and evaluation systems, plurality of apparatus, assemblies, and devices as herein disclosed and described, ii) the related processes and methods disclosed and described, iii) similar, equivalent, and even implicit variations of each of these systems, plurality of apparatus, assemblies, and devices, processes and methods, iv) those alternative designs which accomplish each of the functions shown as are disclosed and described, v) those alternative designs and methods which accomplish each of the functions shown as are implicit to accomplish that which is disclosed and described, vi) each feature, component, and step shown as separate and independent inventions, vii) the applications enhanced by the various systems or components disclosed, viii) the resulting products produced by such systems or components, ix) methods and systems, plurality of apparatus, assemblies, and devices substantially as described hereinbefore and with reference to any of the accompanying examples, x) the various combinations and permutations of each of the elements disclosed, xi) each potentially dependent claim or concept as a dependency on each and every one of the independent claims or concepts presented, xii) processes performed with the aid of or on a computer as described throughout the above discussion, xiii) a programmable apparatus as described throughout the above discussion, xiv) a computer readable memory encoded with data to direct a computer comprising means or elements which function as described throughout the above discussion, xv) a computer configured as herein disclosed and described, xvi) individual or combined subroutines and programs as herein disclosed and described, xvii) the related methods disclosed and described, xviii) similar, equivalent, and even implicit variations of each of these systems and methods, xix) those alternative designs which accomplish each of the functions shown as are disclosed and described, xx) those alternative designs and methods which accomplish each of the functions shown as are implicit to accomplish that which is disclosed and described, xxi) each feature, component, and step shown as separate and independent inventions, and xxii) the various combinations and permutations of each of the above. In this regard it should be understood that for practical reasons and so as to avoid adding potentially hundreds of claims, the applicant has presented claims with initial dependencies only. Support should be understood to exist to the degree required under new matter laws—including but not limited to United States Patent Law 35 USC 132 or other such laws—to permit the addition of any of the various dependencies or other elements presented under one independent claim or concept as dependencies or elements under any other independent claim or concept. To the extent that insubstantial substitutes are made, to the extent that the applicant did not in fact draft any claim so as to literally encompass any particular embodiment, and to the extent otherwise applicable, the applicant should not be understood to have in any way intended to or actually relinquished such coverage as the applicant simply may not have been able to anticipate all eventualities; one skilled in the art, should not be reasonably expected to have drafted a claim that would have literally encompassed such alternative embodiments. Further, the use of the transitional phrase “comprising” is used to maintain the “open-end” claims herein, according to traditional claim interpretation. Thus, unless the context requires otherwise, it should be understood that the term “comprise” or variations such as “comprises” or “comprising”, are intended to imply the inclusion of a stated element or step or group of elements or steps but not the exclusion of any other element or step or group of elements or steps. Such terms should be interpreted in their most expansive form so as to afford the applicant the broadest coverage legally permissible. | <SOH> BACKGROUND OF THE INVENTION <EOH>Coalbed methane (CBM) is the composite of components that may be adsorbed on coal at the naturally occurring conditions of reservoir pressure and temperature. As pressure is reduced, the CBM begins desorbing from the coal once the critical desorption pressure (CDP) is reached. CBM may consist largely of methane with smaller amounts of impurities, typically nitrogen and carbon dioxide and some minor amounts of intermediate hydrocarbons. The capture and sale of CBM is a burgeoning industry both in the United States and internationally. In the CBM industry, a typical procedure for CBM recovery is often to penetrate the geologic formation with a substantially vertically drilled well and to either 1) case the hole, typically with steel casing through the coal interval followed by cementing the casing in place and perforating the interval all by methods commonly known in the petroleum industry, or 2) to case in a like manner the hole to the top of the coal and then drill through the coal, perhaps widening the hole drilled through the coal by a process known in the industry as underreaming. The former case is known as a cased completion and the latter is known as an open-hole completion. In either case, when producible water is present, typically water is pumped from the well through a tubing string to the surface in an attempt to lower the reservoir pressure, a generally necessary condition for releasing commercial quantities of CBM in most production scenarios. As reservoir pressure is lowered, a free gas phase will eventually form at the bottom of the hole and most of the free gas then will rise in the annulus between the casing and the tubing by gravitational forces, allowing the relatively buoyant gas to be produced at the surface from the annulus of the casing. The gas produced is then gathered and then typically sent to markets through pipelines. Many CBM wells that will ultimately produce commercial quantities of coalbed methane do not do so when first put into production. The only gas produced initially in such wells is the relatively minute, generally noncommercial, quantity of gas that is in solution in the water at bottom-hole conditions of pressure and temperature. Most of this minute quantity will come out of solution as the produced formation water moves from conditions at the bottom of the hole to the lower pressure and typically different temperature at the surface. Such coal formations that do not produce gas initially beyond the amount contained in solution in the formation water are said to be undersaturated at reservoir conditions of pressure and temperature. Other definitions for undersaturated coals include: 1) when the storage capacity of the coal, typically expressed in standard (usually 14.7 psia and 60 deg F.) cubic feet of gas per ton of coal, exceeds the actual gas content of the coal expressed in the same units at reservoir pressure, or 2) when no free gas phase exists in the cleats and fracture system at reservoir conditions. Storage capacity of the coal is typically determined in the laboratory from a captured sample of coal. A plot of the data is often made having the ordinate typically expressed in SCF/Ton and the abscissa being absolute pressure. This data is also often statistically fit with an equation to yield a curve, one such commonly used curve being known as the Langmuir isotherm as described in the reference of Yee et al., 1993. These “isotherms”, as the term implies, are measured at constant temperature generally corresponding to that of the reservoir from which the sample was obtained. Unfortunately, some of the undersaturated CBM reservoirs may never produce commercial quantities of coalbed methane. One concern, therefore, is the determination of whether or not the coals in these undersaturated CBM reservoirs contain sufficient gas to be commercial. Such information, if it could be determined expediently on a given well in an exploratory area, could prevent the drilling of a large number of wells in the specific area that may never produce economic quantities of CBM. As mentioned above, one common method of making that determination is through the process of obtaining a sample of the coal itself, perhaps by coring the coal, and subsequent detailed measurement of gas content of that sample in a laboratory or otherwise. This technique is typically expensive, and can require specialized drilling equipment and personnel. Additional expense may be incurred when the core samples are sent to commercial or private laboratories for analysis. The results of such core analyses are not immediately available, sometimes taking months of desorption time. Also, because core analysis may be too expensive for a large amount of sampling to be taken from a particular well, samples, hoped to be representative, are often selected. Consequently, there is the potential problem of the core samples not being representative of the formation even nearby the well from which the core was cut; and there is an additional problem of how representative the samples will be of the formation at some distance from the well. The CBM industry is replete with examples of how gas content can drastically change over relatively short distances. It is typically neither economically practical nor timely to have every well cored and analyzed. The results from a sample of the coal itself, perhaps from the coring process, can also be very inconsistent from what is ultimately observed during production. During a coring or other sampling operation, not only are samples of coal pulled for determining gas content in the laboratory, but also a specific sample or a composite sample, possibly made up from drill cuttings, may be gathered and this sample used to determine storage capacity of the coal. This can involve tedious and expensive laboratory processes. The commercial or private laboratory may then compare the gas content measured in some samples with the storage capacity determined from another sample and estimate the degree of saturation of the coal. As explained above, if the measured gas content is less than the storage capacity, the coal is said to be undersaturated with gas, and the laboratory will typically determine the pressure at which the gas content intersects a plot of the storage capacity data. The resulting pressure is typically referred to as the critical desorption pressure (CDP). The CDP is the reservoir pressure at which CBM will start to desorb from the coal with reduction of reservoir pressure, become a gaseous phase, and begin to become capable of production in commercial quantities. Unfortunately, the value of CDP determined by the laboratories, too frequently, has been grossly in error from what was ultimately observed when the wells were produced. The present inventor has identified such error in the coring and subsequent laboratory analyses of several of approximately ten wells, analyzed under traditional core analysis using different laboratories. Some analyses have indicated that the reservoirs are saturated at reservoir pressure, yet these reservoirs have not produced any commercial quantities of gas until the reservoir pressure has been drawn down to at least 50 to 60% of the initial reservoir pressure before reaching the CDP. Some of the analyses indicate that the gas contents exceed the storage capacities of the coals at reservoir pressure, something that appears to defy an adequate physical explanation. In summary, coal sampling, coring, and subsequent core analyses as described above may lead to results that are not only time consuming and expensive to obtain, but also they can be highly questionable and frequently inconsistent when used for individualized analysis. For individualized analysis, due to uncertainty, the better use for coal sampling, coring, and core analyses may not come from individual assessments but instead from multiple assessments from which composite isotherms are constructed for a given geological region by averaging of the data and statistically demonstrating the uncertainty. This has been done in the Powder River Basin (PRB) by the United States Bureau of Land Management (BLM) as described in the reference to Crockett and Meyer, 2001. For example, from some 40 samples, the BLM has constructed an averaged synthesized isotherm for samples measured in the PRB representing these 40 samples. Even from such a relatively large number of samples, and ignoring the cost challenges to achieve such data, this effort highlights the challenges in a coal sampling approach because uncertainty in the data still exists. In fact this data shows significantly differing isotherms that represent one standard deviation on either side of the mean curve. Another problem under traditional analysis can, and does, occur in some undersaturated CBM reservoirs when one tries to demonstrate, perhaps through individual testing or small-scale pilots of several adjacent wells, that the well(s) will ultimately produce commercial quantities of CBM. A long and uncertain dewatering period, even under the best of circumstances, may be required before any commercial quantities of CBM are produced. This can lead to long periods of evaluation time. In some areas where there is high permeability and strong aquifer support, such as can be the case in the PRB, one well cannot draw down the pressure sufficiently to ever reach the CDP in any sort of practical or economic time frame. In response to this problem and in an effort to evaluate their leases, most operators have drilled costly (multi-million dollar) multiple-well pilots in an effort to cause interference between wells so that these wells, in combination, can draw the pressure down sufficiently to reach the CDP by exceeding the water influx into the pilot area. Some of these pilots have been successful in the PRB, but some of the pilots have been dewatering for over three years without yet producing commercial quantities of CBM. This dewatering is done at considerable cost of equipment and power to pump wells, at a financial cost of deferred revenues and with the uncertainty that the ultimate resource to be found may not be sufficient to be profitable. The practical challenges of laboratory involvement and sampling difficulty known to exist in a coal sampling-based technique are perhaps highlighted by reference to U.S. Pat. No. 5,785,131 to Gray. Although this reference involves techniques for sensing formation fluids as in gas-oil systems when the fluid itself is of interest, as it relates to the very different aspect of sampling solids containing a substance of interest, it proposes a system for pressurized capture of the samples from entrained particles during drilling. In the reference, these particles of coal or the like are captured and tested on site to avoid some of the mentioned challenges of laboratory testing. As it relates to the solids such as are of interest in the present invention, however, this reference still relies on a capture of the entrained particles and as such it is subject to the uncertainties and other practical limitations discussed above. Another alternative to those techniques based on sampling of the coal itself involves the use of mudlogging during drilling to obtain, at least a qualitative indication of the presence of CBM. Some have even tried to quantify results (Donovan, 2001), but these techniques can leave much to be desired and problems can exist because the system is not usually closed, thus allowing unmeasured gas to escape. Gas-free drilling water is also typically mixed with formation water of different gas content. Further, particle size can need to be estimated, drilling speed recorded, etc. Then, too, results observed by the inventor for the PRB seem to indicate gas contents that are typically far in excess of those observed. Finally, such techniques provide, at best, an estimate for gas content of the coal and do not provide the practical accuracies desired, neither do these techniques provide an estimate for CDP. Other than the coal sampling-based techniques mentioned above, efforts (e.g., see Koenig, 1988) have included attempts to determine CDP by producing the well and dropping the pressure, perhaps by bailing or by a pump lowered into the well until gas starts being produced. These techniques can be fraught with problems, some of which are: 1) if a pump is used in the well, its capacity may not be sufficient to draw the well down in a practical testing time frame to determine when gas starts being produced; 2) as the liquid level drops in the well, air may be pulled into the casing from the surface, if the casing is open at the surface, because the pressure in the casing will likely be lower than the atmospheric pressure at the surface, or if the casing is isolated from atmospheric pressure (e.g., shut in) a vacuum may be drawn on the well and a negative gauge pressure (in this document gauge pressure will refer to measurement of pressure above atmospheric pressure where zero gauge pressure would correspond to atmospheric pressure) may result until there is sufficient release of gas from the coal to overcome the vacuum being drawn by the falling liquid level; and 3) by the time the pressure is drawn down sufficiently to see gas production at the surface, the reservoir may already be affected by two-phase flow that may lead to complications in interpretation. This can also produce results inconsistent with later production history. | <SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, broad objects of the invention may include providing techniques and systems to evaluate undersaturated coalbed methane reservoirs and determine particular characteristics of the coal in such reservoirs from other than a sample of the coal itself. Further broad objects may include providing techniques and systems to determine critical desorption pressure of coalbed methane reservoirs and other reservoir characteristics such as characteristics that may be relevant to economic viability or the like. Each of the broad objects of the present invention may be directed to one or more of the various and previously described concerns. Further objects of the present invention may include the characterization and evaluation of undersaturated coalbed methane reservoirs based upon characteristics such as critical desorption pressure, gas content, gas content as calculated from isotherm evaluation, estimates of dewatering for production, and ratios of critical desorption pressure to initial reservoir pressure, among other possible characteristics as presently disclosed. Other objects of the present invention include characterization and evaluation of coalbed methane reservoirs consistent with the techniques presently disclosed and potentially in combination with conventional reservoir analysis, such as coring, logging, reservoir isotherm evaluation, or other techniques. Naturally, further objects, goals, and advantages of the invention are disclosed and clarified throughout this disclosure and in the following written description. To achieve the above-recited objects and the other objects, goals, and advantages of the invention as provided throughout this present disclosure, the present invention may comprise techniques and systems of testing a substance other than the coal or other solid actually of interest in order to inductively quantify a methane content characteristic for sorbed methane in the solid; to understand any factor that bears directly or indirectly on methane content, including but not limited to bubble point, critical desorption pressure, gas-water ratio, or the like. This invention even shows that a test of a characteristic of the formation water, a substance whose characteristics may have been generally thought to be unrelated to the amount of methane sorbed on the solid coal, can be used qualitatively and quantitatively to determine gas content or the like of coal. In addition, the invention shows that the test of the water can even permit inductive quantification of the critical desorption pressure of the coal in an undersaturated coalbed methane reservoir. By inductive quantification, it can be understood that the result is surprising, based on previous knowledge of a person of ordinary skill in the art, in that it is a previously-thought-of-as-being-unrelated-value that yields the desired result. From this method, determinations can be deduced and inferred and the result can be obtained earlier and less expensively than previously done. In some preferred embodiments, the invention includes a method of determining critical desorption pressure of an undersaturated coalbed methane reservoir comprising the steps of: determining a solution gas-water ratio of formation water of the reservoir; determining the bubble point pressure of the formation water corresponding to the solution gas-water ratio; and determining critical desorption pressure of the reservoir from the bubble point pressure of the formation water. In other preferred embodiments, the invention includes a method of determining critical desorption pressure of an undersaturated coalbed methane reservoir comprising the steps of determining the bubble point pressure of the formation water of the reservoir and determining critical desorption pressure of the reservoir from the bubble point pressure of the formation water. To further achieve the above-recited objects and the other objects, goals, and advantages of the invention as provided throughout this present disclosure, the present invention may comprise methods of undersaturated coalbed methane reservoir characterization and characterizing the coalbed methane reservoir from characteristics such as: critical desorption pressure, gas content, gas content as calculated from isotherm evaluation, estimates of dewatering for production, and ratios of critical desorption pressure to initial reservoir pressure, among other possible characteristics as presently disclosed. The invention may also include determinations of critical desorption pressure and characterization of undersaturated coalbed methane reservoirs in combination with conventional reservoir analysis, such as coring, logging, reservoir isotherm evaluation, or other techniques. The present invention teaches that the bubble point of the formation water can be used to inductively quantify the CDP of the coal in the coalbed methane reservoir and that there is no requirement that the formation water remain in contact or carry with it coal as may have been thought necessary. Thus, through embodiments, the CDP of coal in an undersaturated coalbed methane reservoir may be quickly, easily, accurately, and relatively inexpensively determined by the use of one or more CBM wells in an area, and an excellent estimate of gas content can now be made. Further, as mentioned, an estimate of the amount of dewatering necessary to reduce the reservoir pressure from its initial value to the CDP can now be estimated in a practical manner. Importantly, by knowing the CDP in a practical manner, ultimately an economic analysis can now be made of the prospect a priori the drilling of a large number of pilot wells, potentially at tremendous savings in time and investment costs to the operators. Further, by the CDP being known in a practical and more economic manner such as disclosed as part of the present invention, it is now possible to use an isotherm to determine gas content of the coal. Additionally, one can now more practically use an isotherm specifically measured for an area, can use an isotherm determined in accordance with techniques such as core analysis, may use correlations similar to the aforementioned BLM correlations for a given geologic area, or even may (admittedly with less precision) even use very general correlations based on rank of the coal such as are publicly known (Eddy et al, 1982). Finally, through the present invention, one may not even have to use an isotherm at all, but may be able to use the CDP to rank prospects for development in a given geologic area where the variations in gas content may be due to varying degrees of undersaturation. The previously described embodiments of the present invention and other disclosed embodiments are also disclosed in the following written description. The entirety of the present disclosure teaches, among other aspects, a novel and nonobvious method of characterizing, among other things, undersaturated coalbed methane reservoirs of gas-water systems, and other techniques that circumvent many of the problems of timeliness, inaccuracy and expense identified above for other state-of-the art methods. | 20040228 | 20070515 | 20050908 | 65502.0 | 2 | STEPHENSON, DANIEL P | METHODS OF EVALUATING UNDERSATURATED COALBED METHANE RESERVOIRS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,790,482 | ACCEPTED | MODULAR CONVEYING ASSEMBLY WITH STUB MOUNTED IN-LINE ROLLERS | A modular conveying assembly includes a conveyor belt module for use with in-line rollers. The module includes first and second hinge member. The first hinge member extends forwardly in the direction of conveyor travel, and includes a first opening defining a first space extending along an axis transverse to the direction of conveyor travel for receiving a first hinge pin. The second hinge member extends in a direction opposite to the first hinge member, and includes a second opening defining a second space extending along an axis transverse to the direction of conveyor travel for receiving a second hinge pin. A stub extends from the first hinge member transverse to the direction of conveyor travel, and surrounds at least a portion of the first space for rotatably mounting a roller thereon for rotation around the first space. | 1. A conveyor belt module for use in a modular conveying assembly, said module comprising: a body having a top surface defined by a leading edge and a trailing edge joined by side edges: a first hinge member extending forwardly from said body in a direction of conveyor travel and including a first opening defining a first space extending along an axis transverse to the direction of conveyor travel for receiving a first hinge pin; a second hinge member extending from said body in a direction opposite to the first hinge member and including a second opening defining a second space extending along an axis transverse to the direction of conveyor travel for receiving a second hinge pin; a stub extending from said first hinge member transverse to the direction of conveyor travel, and surrounding at least a portion of said first space for rotatably mounting a roller thereon for rotation around said first space; and a roller encircling said stub for rotation around said first space. 2. (canceled) 3. The conveyor belt module as in claim 1, in which said roller extends above the module. 4. The conveyor belt module as in claim 1, in which said roller extends below the module. 5. The conveyor belt module as in claim 1, in which said first hinge members extends forwardly from said leading edge, and said second hinge member extends rearwardly from said trailing edge. 6. The conveyor belt module as in claim 1 in which said top surface includes a notch for a portion of the roller extending therethrough above said top surface. 7. The conveyor belt module as in claim 1, in which said stub extends in a first transverse direction from said first hinge member, and second stub extends in a second transverse direction from said second hinge member, and said first transverse direction is opposite of said second transverse direction. 8. The conveyor belt module as in claim 1, in which said conveyor module includes at least one other first hinge member and at least one other second hinge member, said first other hinge member extending forwardly in the direction of conveyor travel and including an opening coaxial with said first opening and defining said first space extending along an axis transverse to the direction of conveyor travel for receiving the first hinge pin, and said second other hinge member extending forwardly in the direction of conveyor travel and including an opening coaxial with said second opening and defining said second space extending along an axis transverse to the direction of conveyor travel for receiving the second hinge pin. 9. A conveyor belt module for use in a modular conveying assembly, said module comprising: a first hinge member extending forwardly in a direction of conveyor travel and including a first opening defining a first space extending along an axis transverse to the direction of conveyor travel for receiving a first hinge pin; a second hinge member extending in a direction opposite to the first hinge member and including a second opening defining a second space extending along an axis transverse to the direction of conveyor travel for receiving a second hinge pin; a stub extending from said first hinge member transverse to the direction of conveyor travel, and surrounding at least a portion of said first space for rotatably mounting a roller thereon for rotation around said first space, said stub including a proximal end fixed to said first hinge member and a distal end; and a lip extending radially from said stub around at least a portion of said stub proximal said distal end to prevents the roller from slipping axially off of said stub. 10. A conveyor belt module for use in a modular conveying assembly, said module comprising: a first hinge member extending forwardly in a direction of conveyor travel and including a first opening defining a first space extending along an axis transverse to the direction of conveyor travel for receiving a first hinge pin; a second hinge member extending in a direction opposite to the first hinge member and including a second opening defining a second space extending along an axis transverse to the direction of conveyor travel for receiving a second hinge pin; a stub extending from said first hinge member transverse to the direction of conveyor travel, and surrounding at least a portion of said first space for rotatable mounting a roller thereon for rotation around said first space, wherein said first space defines a transverse axis which is coaxial with a hinge pin received in the space, and said roller rotates about an axis of rotation offset from said transverse axis. 11. The conveyor belt module as in claim 10, in which said conveyor module includes a top surface defined by a leading edge and a trailing edge joined by side edges, and said first hinge members extends forwardly from said leading edge, and said second hinge member extends rearwardly from said trailing edge, and said axis of rotation is offset towards said top surface. 12. The conveyor belt module as in claim 10, in which said conveyor module includes a top surface defined by a leading edge and a trailing edge joined by side edges, and said first hinge members extends forwardly from said leading edge, and said second hinge member extends rearwardly from said trailing edge, and said axis of rotation is offset away from said top surface. 13. A modular conveying assembly comprising: a first conveyor module having a body including first hinge member extending from said body in a direction of conveyor travel, said first hinge member including a first opening, a second hinge member extending from said body in a direction opposite to the first hinge member and including a second opening, and a stub extending from said first hinge member transverse to the direction of conveyor travel; a second conveyor module having a first hinge member extending in a direction of conveyor travel, said first hinge member including a first opening, a second hinge member extending in a direction opposite to the first hinge member and including a second opening, wherein said first opening of said first conveyor module is substantially aligned with said second opening of said second conveyor module, and said stub extending from said first hinge member of said first conveyor module extends toward said second hinge member of said second conveyor module; a hinge pin extending through said first opening of said first conveyor module and said second opening of said second conveyor module, and said stub wrapping around at least a portion of said hinge pin; and a roller encircling said stub for rotation around said hinge pin. 14. (canceled) 15. The modular conveying assembly as in claim 13, in which said roller extends above the module. 16. The modular conveying assembly as in claim 13, in which said roller extends below the module. 17. The modular conveying assembly as in claim 13, in which said first conveyor module body includes a top surface defined by a leading edge and a trailing edge joined by side edges, and said first hinge members extends forwardly from said leading edge, and said second hinge member extends rearwardly from said trailing edge. 18. The modular conveying assembly as in claim 17, in which said top surface includes a notch for a portion of the roller extending therethrough above said top surface. 19. The modular conveying assembly as in claim 13, in which said stub extends in a first transverse direction from said first hinge member, and a second stub extends in a second transverse direction from said second hinge member, and said first transverse direction is opposite of said second transverse direction. 20. The modular conveying assembly as in claim 13, in which said first conveyor module includes at least one other first hinge member and at least one other second hinge member, said first other hinge member extending forwardly in the direction of conveyor travel and including an opening coaxial with said first opening, and said second other hinge member extending forwardly in the direction of conveyor travel and including an opening coaxial with said second opening. 21. The modular conveying assembly as in claim 13, in which said stub includes a proximal end fixed to said first hinge member and a distal end, and a lip extending radially from said stub around at least a portion of said stub proximal said distal end prevents the roller from slipping axially off of said stub. 22. The modular conveying assembly as in claim 13, in which said hinge pin defines a transverse axis, and said roller rotates about an axis of rotation offset from said transverse axis. 23. The modular conveying assembly as in claim 13, in which said conveyor module includes a top surface defined by a leading edge and a trailing edge joined by side edges, and said first hinge members extends forwardly from said leading edge, and said second hinge member extends rearwardly from said trailing edge, and said axis of rotation is offset towards said top surface. | CROSS REFERENCES TO RELATED APPLICATIONS This application claims the priority benefit of U.S. provisional Patent Application No. 60/529,557 filed on Dec. 15, 2003. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH Not Applicable. BACKGROUND OF THE INVENTION The present invention relates to modular conveyor belts and chains, and more particularly to a conveyor module having in-line rollers and a modular conveying assembly including at least one of the conveyor modules. Modular belting and chains are formed from interconnected modules that are supported by a frame and driven to transport a product. Each module has a support surface which supports the product as the belting or chain is being driven along the frame. Adjacent modules are connected to each other by hinge pins inserted through hinge members extending from adjacent modules in the direction of the belt travel. Modular belts can transport products in the direction of conveyor travel, but have difficulty accumulating a product to reduce back-line pressure. In addition, high friction products can easily damage the belt if the product is accumulated. One known solution to this problem is to rotatably mount rollers directly on the hinge pin connecting modules together, such that the hinge pin supports the rollers between hinge members. The roller rotates about an axis of rotation that is substantially coaxial with the hinge pin axis. Because it is often desired to have a portion of the roller extend beyond (i.e. above and/or below) the module, the required roller diameter is determined by the hinge pin location and the height of the module. Unfortunately, this often results in requiring a large diameter roller that extends both above and below the module when that configuration is not always desired. Moreover, supporting the roller on the pin alone can result in undesirable pin wear. Another known solution for reducing back-line pressure is disclosed in U.S. Pat. No. 4,231,469 issued to Arscott. In Arscott rollers are supported by roller cradles between modules. The rollers extend above the cradle for rolling contact with an object being conveyed independent of the location of the hinge pins. The rollers reduce friction between the belt and the object. Unfortunately, assembling the roller in the cradle is difficult, requiring insertion of the roller into the cradle, and then slipping an axle or two stub axles through holes formed through the cradle walls and into the roller. The axle must then be secured to prevent it from slipping out of one of the holes formed in the cradle wall. SUMMARY OF THE INVENTION The present invention provides a modular conveying assembly for minimizing damage to the belt and reducing back-line pressure when accumulating products. The modular conveying assembly includes a conveyor belt module for use with in-line rollers. The module includes first and second hinge member. The first hinge member extends forwardly in the direction of conveyor travel, and includes a first opening defining a first space extending along an axis transverse to the direction of conveyor travel for receiving a first hinge pin. The second hinge member extends in a direction opposite to the first hinge member, and includes a second opening defining a second space extending along an axis transverse to the direction of conveyor travel for receiving a second hinge pin. A stub extends from the first hinge member transverse to the direction of conveyor travel, and surrounds at least a portion of the first space for rotatably mounting a roller thereon for rotation around the first space. A general objective of the present invention is to provide a belt module and a modular conveying assembly formed therefrom that can accumulate objects without severely damaging the objects or the assembly. This objective is accomplished by providing a stub that can support a roller that reduces friction between the object and the conveying assembly. Another objective of the present invention is to provide a belt module that can support a roller independent of the hinge pin. This objective is accomplished by providing a stub that defines the roller axis of rotation independent of the hinge pin axis. This and still other objectives and advantages of the present invention will be apparent from the description which follows. In the detailed description below, preferred embodiments of the invention will be described in reference to the accompanying drawing. These embodiments do not represent the full scope of the invention. Rather the invention may be employed in other embodiments. Reference should therefore be made to the claims herein for interpreting the breadth of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a modular conveyor belt incorporating the present invention; FIG. 2 is a perspective view of a module of FIG. 1; FIG. 3 is an elevational edge view of the module of FIG. 2; FIG. 4 is an elevational edge view of a module having a roller extending below the module which is suitable for use in the belt of FIG. 1; and FIG. 5 is an elevational edge view of a module having a roller extending above and below the module which is suitable for use in the belt of FIG. 1. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS A modular conveying assembly, or belt 10, shown in FIG. 1, includes a plurality of belt modules 12 assembled in an edge to edge relation to form the continuous belt 10. Hinge pins 40 join adjacent modules 12, and pivotally connect the adjacent modules 12 in the direction of belt travel. Stubs 26, 54 wrapping around at least a portion of the hinge pins 40 support in-line rollers 28 that rotatably engage an object being conveyed by the belt 10 to reduce friction between the belt 10 and the object. Advantageously, if the module 12 or roller 28 is damaged, only the damaged component need be replaced. Although, the terms “leading” and “trailing” are used to identify features of the module 12, the module 12 described herein can be used in any direction, or orientation without departing from the scope of the invention. The modules 12 are preferably formed using methods known in the art, such as injection molding, from materials known in the art, such as acetal, polyethylene, polypropylene, nylon, and the like. Each module 12 includes a body 14 having a top surface 24 surrounded by a leading edge 16 and trailing edge 18 joined by a first side edge 20 and a second side edge 22. Advantageously, the top surface 24 can prevent products from falling through the belt 10. Of course, the top surface 24 can also have perforations to allow air or fluid flow for cooling, drafting, and/or draining. The module body 14 has a width which is defined by the distance between the side edges 20, 22, and a length which is defined by the distance between the leading and trailing edges 16, 18. Notches 34, 36 formed in the edges 16, 18, 20, 22 define spaces between adjacent modules 12 for receiving the rollers 28 supported by the stubs 26, 54. Preferably, a corner notch 34 is formed in each corner of the module body 14 and a center notch 36 is formed in the leading and trailing edges 16, 18 between the side edges 20, 22 to allow assembling the modules in a “bricklaying” fashion. In the “bricklaying” fashion, a pair of corner notches 34 combine with a center notch 36 to define a single space between three adjacent modules 12 for receiving a roller 28 supported by one of the stubs 26, 54. Of course, the number, size, and location of notches is dependent upon the desired number, size, and location of rollers. Moreover, notches can be omitted from the module without departing from the scope of the invention. Each leading edge hinge member 30 extends forwardly from the leading edge 16 of the module body 14, and includes a coaxial opening 38 for receiving the hinge pin 40. Each leading edge hinge member opening 38 defines a space 57 (shown in FIG. 3) extending along a hinge pin centerline axis 42 transverse to the direction of travel for receiving the hinge pin 40 pivotally connecting the leading edge hinge members 30 of one module 12 to trailing edge hinge members 32 of an upstream module 12. A leading edge stub 26 extending from the leading edge hinge member 30 nearest the second side edge 22 of the module body 14 wraps at least partially around the hinge pin 40, and thus the space defined by the leading edge hinge member opening 38. The leading edge stub 26 extends in a transverse direction away from an outwardly transverse facing surface 44 of the leading edge hinge member 30 toward the nearest adjacent module 12 in the row, and supports a roller 28 which rotates about a roller axis of rotation that is offset above (i.e. toward the module top surface 24) the leading edge hinge pin axis 42. Advantageously, the leading edge stub 26 engages the roller 28 above the space defined by the leading edge hinge member opening 38 to raise the roller axis 58 of rotation above the hinge pin axis 42 so a portion of the roller 28 extends above the module top surface 24 for contact with the objects being conveyed. In addition, the stub 26 reduces wear on the hinge pin 40 caused by the rotating roller 28. Preferably, the leading edge stub 26 extends from a proximal end 46 fixed to the leading edge hinge member 30 to a distal end 48. A radially extending lip 50 formed proximal the stub distal end 48 engages the roller 28 supported by the leading edge stub 26 to prevent the roller 28 from slipping axially off of the leading edge stub 26 as the belt 10 is being assembled. Trailing edge hinge members 32 extending rearwardly from the trailing edge 18 also include coaxial openings 52. As in the leading edge hinge member openings 38, each trailing edge hinge member opening 52 defines an axially extending space coaxial with the hinge pin axis 42 transverse to the direction of travel. The trailing edge hinge pin openings 52 receive the hinge pin 40 pivotally connecting the trailing edge hinge members 32 of the module 12 to leading edge hinge members 30 of a downstream module 12. A trailing edge stub 54 extending from the trailing edge hinge member 32 nearest the first side edge 20 of the module body 14 wraps at least partially around the hinge pin 40, and thus the space defined by the trailing edge hinge member opening 52. The trailing edge stub 54 extends in a transverse direction away from an outwardly transverse facing surface 56 of the trailing edge hinge member 32 in an opposite direction from the leading edge stub 26 toward the nearest adjacent module 12 in the row, and supports a roller 28 which rotates around the hinge pin 40, and thus the hinge pin axis 42 and the axially extending space 57 defined by the leading and trailing edge hinge member openings 38, 52. Advantageously, as in the leading edge stub 26, the trailing edge stub 54 engages the roller 28 above the space defined by the trailing edge hinge member opening 52 to raise the roller axis 58 of rotation above the hinge pin axis 42 so a portion of the roller 28 extends above the module top surface 24 for contact with the objects being conveyed. Preferably, the trailing edge stub 54 extends from a proximal end 60 fixed to the trailing edge hinge member 32 to a distal end 62. A radially extending lip 64 formed proximal the stub distal end 62 engages the roller 28 supported by the trailing edge stub 54 to prevent the roller 28 from slipping axially off of the trailing edge stub 54 as the belt 10 is being assembled. The rollers 28 support an object being conveyed by the belt 10, and allows movement of the object in the direction of conveyor travel to reduce back-line pressure. At least a portion of the roller 28 extends above the module top surface to engage the object being conveyed by the belt 10. Preferably, the roller 28 is molded from a plastic, and includes a throughhole 66 formed therethrough for receiving the hinge pin 40 and one of the stubs 26, 54. Advantageously, the roller 28 rotates around the hinge pin 40 to minimize friction between the belt 10 and object being conveyed and reduce the back-line pressure of objects accumulating on the belt 10. Although a plastic roller is disclosed, the roller can be formed from any material, such as elastomers, metals, and the like, suitable for the particular application without departing from the scope of the invention. The belt 10 is assembled by slipping a roller onto each stub 26, 54 of adjacent modules 12, and intermeshing the trailing edge hinge members 32 of one of the modules 12 with the leading edge hinge members 30 of the adjacent module 12, such that the trailing hinge member openings 52 of the one module 12 are aligned with and the leading edge hinge member openings 38 of the other module 12. A hinge pin 40 is then slipped through the aligned hinge member openings 38, 52 to pivotally link the adjacent modules 12 together. A module 12 having stubs 26,54 that support the roller 28 which rotates about a roller axis 58 of rotation that is offset above (i.e. toward the module top surface 24) the leading edge hinge pin axis 42 is preferred. However, in certain applications it is desirable to provide a module having stubs that support a roller which rotates about a roller axis of rotation that is offset above (shown in FIG. 3), offset below (shown in FIG. 4), and/or coaxial with (shown in FIG. 5), the leading edge hinge pin axis 42. As shown in FIG. 4, a module 112 incorporating the present invention includes a leading edge stub 126 that extends below the leading edge hinge pin axis 142. The stub 126 rotatably supports a roller 128 which rotates about a roller axis of rotation that is offset below (i.e. away from the module top surface 124) the leading edge hinge pin axis 142. Advantageously, the roller 128 extends below the module 112 and is engageable with a supporting surface (not shown) to reduce friction between a belt including the module 112 and the supporting surface. Of course, the module 112 can include a trailing edge stub, such as described above, or which supports a roller having an axis of rotation below, or coaxial with, a trailing edge hinge pin axis. As shown in FIG. 5, a module 212 incorporating the present invention includes a leading edge stub 226 that is coaxial with the leading edge hinge pin axis 242. The stub 226 rotatably supports a roller 228 which rotates about a roller axis of rotation that is coaxial with the leading edge hinge pin axis 242. The roller 228 is sized such that it extends above and below the module 212 and is engageable with a supporting surface (not shown) and an object (not shown) being conveyed. Advantageously, the supporting surface rotates the roller 228 to accelerate the object being conveyed. Of course, the module 212 can include a trailing edge stub, such as described above, or which supports a roller having an axis of rotation below, or coaxial with, a trailing edge hinge pin axis. While there has been shown and described what are at present considered the preferred embodiments of the invention, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention defined by the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates to modular conveyor belts and chains, and more particularly to a conveyor module having in-line rollers and a modular conveying assembly including at least one of the conveyor modules. Modular belting and chains are formed from interconnected modules that are supported by a frame and driven to transport a product. Each module has a support surface which supports the product as the belting or chain is being driven along the frame. Adjacent modules are connected to each other by hinge pins inserted through hinge members extending from adjacent modules in the direction of the belt travel. Modular belts can transport products in the direction of conveyor travel, but have difficulty accumulating a product to reduce back-line pressure. In addition, high friction products can easily damage the belt if the product is accumulated. One known solution to this problem is to rotatably mount rollers directly on the hinge pin connecting modules together, such that the hinge pin supports the rollers between hinge members. The roller rotates about an axis of rotation that is substantially coaxial with the hinge pin axis. Because it is often desired to have a portion of the roller extend beyond (i.e. above and/or below) the module, the required roller diameter is determined by the hinge pin location and the height of the module. Unfortunately, this often results in requiring a large diameter roller that extends both above and below the module when that configuration is not always desired. Moreover, supporting the roller on the pin alone can result in undesirable pin wear. Another known solution for reducing back-line pressure is disclosed in U.S. Pat. No. 4,231,469 issued to Arscott. In Arscott rollers are supported by roller cradles between modules. The rollers extend above the cradle for rolling contact with an object being conveyed independent of the location of the hinge pins. The rollers reduce friction between the belt and the object. Unfortunately, assembling the roller in the cradle is difficult, requiring insertion of the roller into the cradle, and then slipping an axle or two stub axles through holes formed through the cradle walls and into the roller. The axle must then be secured to prevent it from slipping out of one of the holes formed in the cradle wall. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides a modular conveying assembly for minimizing damage to the belt and reducing back-line pressure when accumulating products. The modular conveying assembly includes a conveyor belt module for use with in-line rollers. The module includes first and second hinge member. The first hinge member extends forwardly in the direction of conveyor travel, and includes a first opening defining a first space extending along an axis transverse to the direction of conveyor travel for receiving a first hinge pin. The second hinge member extends in a direction opposite to the first hinge member, and includes a second opening defining a second space extending along an axis transverse to the direction of conveyor travel for receiving a second hinge pin. A stub extends from the first hinge member transverse to the direction of conveyor travel, and surrounds at least a portion of the first space for rotatably mounting a roller thereon for rotation around the first space. A general objective of the present invention is to provide a belt module and a modular conveying assembly formed therefrom that can accumulate objects without severely damaging the objects or the assembly. This objective is accomplished by providing a stub that can support a roller that reduces friction between the object and the conveying assembly. Another objective of the present invention is to provide a belt module that can support a roller independent of the hinge pin. This objective is accomplished by providing a stub that defines the roller axis of rotation independent of the hinge pin axis. This and still other objectives and advantages of the present invention will be apparent from the description which follows. In the detailed description below, preferred embodiments of the invention will be described in reference to the accompanying drawing. These embodiments do not represent the full scope of the invention. Rather the invention may be employed in other embodiments. Reference should therefore be made to the claims herein for interpreting the breadth of the invention. | 20040301 | 20050823 | 20050616 | 60100.0 | 0 | DEUBLE, MARK A | MODULAR CONVEYING ASSEMBLY WITH STUB MOUNTED IN-LINE ROLLERS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,790,539 | ACCEPTED | Sound dampening adhesive patterns for vehicle wheel assemblies | Wheel assemblies that include decorative wheel covers which are bonded to wheels by sound dampening adhesive patterns that include primary adhesive patterns that are sufficient to secure the wheel covers to the wheels and an auxiliary adhesive patterns that include discrete portions that are provided in hollow portions defined by the primary adhesive patterns between the wheel covers and wheels. The discrete portions of the auxiliary adhesive patterns prevent the hollow portions from sounding hollow. | 1. A method of securing a wheel cover to a wheel to form a wheel assembly which method comprises: providing a wheel having an outboard surface with a plurality of centrally located lug bolt apertures formed in the outboard surface and a plurality of openings formed in the outboard surface and spaced radially outwardly from the lug bolt apertures; providing a wheel cover having an inner surface and a plurality of centrally located lug bolt apertures formed in the wheel cover which correspond to the lug bolt apertures of the wheel, and a plurality of decorative openings formed in the wheel cover and spaced radially outwardly from the lug bolt apertures, which plurality of openings correspond to the plurality of openings formed in the wheel cover; applying a primary adhesive pattern to at least one of the outboard surface of the wheel or the inner surface of the wheel cover; applying an auxiliary adhesive pattern to at least one of the outboard surface of the wheel or the inner surface of the wheel cover; and assembling the wheel cover to the wheel to cause the primary and auxiliary adhesive patterns to contact both the outboard surface of the wheel and the inner surface of the wheel cover and thereby enable the adhesive pattern to secure the wheel cover to the wheel and define a space between the wheel cover and wheel which is not filled with adhesive, said primary adhesive pattern being sufficient to secure the wheel cover to the wheel and comprising a configuration of beads of adhesive that do not fill the entire space between the wheel cover and the wheel, said auxiliary adhesive pattern being insufficient to secure the wheel cover to the wheel and comprising a configuration of discrete beads of adhesive that are provided in portions of the space between the wheel cover and the wheel which are hollow. 2. A method of securing a wheel cover to a wheel to form a wheel assembly according to claim 1, wherein said primary adhesive pattern includes a configuration of beads of adhesive that after contacting both the outboard surface of the wheel and the inner surface of the wheel cover allows ambient fluids to enter throughout the space between the wheel cover and the wheel which is not filled with adhesive and exit the space. 3. A method of securing a wheel cover to a wheel to form a wheel assembly according to claim 1, wherein the discrete beads of adhesive of the auxiliary adhesive pattern have opposite terminal ends that are non-connected to the primary adhesive pattern. 4. A method of securing a wheel cover to a wheel to form a wheel assembly according to claim 1, wherein the discrete beads of adhesive of the auxiliary adhesive pattern have at least one opposite terminal end that is connected to the primary adhesive pattern. 5. A method of securing a wheel cover to a wheel to form a wheel assembly according to claim 1, wherein the discrete beads of adhesive of the auxiliary adhesive pattern are linear. 6. A method of securing a wheel cover to a wheel to form a wheel assembly according to claim 1, wherein the discrete beads of adhesive of the auxiliary adhesive pattern have curved portions. 7. A method of securing a wheel cover to a wheel to form a wheel assembly according to claim 1, wherein the primary adhesive pattern and the auxiliary adhesive pattern comprise a similar adhesive material. 8. A method of securing a wheel cover to a wheel to form a wheel assembly according to claim 1, wherein the wheel cover is made from one of a metal and a plastic material. 9. A wheel assembly which comprises: a wheel having an outboard surface with a plurality of centrally located lug nut apertures formed in the outboard surface and a plurality of openings formed in the outboard surface and spaced radially outwardly from the lug nut apertures; a wheel cover having an inner surface and a plurality of centrally located lug nut apertures formed in the wheel cover which are aligned with the lug nut apertures of the wheel, and a plurality of decorative openings formed in the wheel cover and spaced radially outwardly from the lug nut apertures, which plurality of openings are aligned with the plurality of openings formed in the wheel cover; a cured primary adhesive pattern between the wheel and wheel cover which bonds the wheel and wheel cover together with a space between the wheel and wheel cover which space is not filled with the cured primary adhesive; and a cured auxiliary adhesive pattern that is insufficient to secure the wheel cover to the wheel and comprises a configuration of discrete beads of adhesive that are provided in portions of the space between the wheel cover and the wheel which are hollow. 10. A wheel assembly according to claim 9, wherein said cured primary adhesive pattern includes a configuration of beads of adhesive that allows ambient fluids to enter throughout the space between the wheel cover and the wheel which is not filled with cured primary adhesive and the cured auxiliary adhesive. 11. A wheel assembly according to claim 9, wherein the discrete beads of adhesive of the cured auxiliary adhesive pattern have opposite terminal ends that are non-connected to the primary adhesive pattern. 12. A wheel assembly according to claim 9, wherein the discrete beads of adhesive of the cured auxiliary adhesive pattern have at least one opposite terminal end that is connected to the cured primary adhesive pattern. 13. A wheel assembly according to claim 9, wherein the discrete beads of adhesive of the auxiliary adhesive pattern are linear. 14. A wheel assembly according to claim 9, wherein the discrete beads of adhesive of the auxiliary adhesive pattern have curved portions. 15. A wheel assembly according to claim 9, wherein the cured primary adhesive pattern and the cured auxiliary adhesive pattern comprise a similar adhesive material. 16. A method of reducing hollow sounds in wheel assemblies which method comprises: providing a wheel having an outboard surface with a plurality of centrally located lug bolt apertures formed in the outboard surface and a plurality of openings formed in the outboard surface and spaced radially outwardly from the lug bolt apertures; providing a wheel cover having an inner surface and a plurality of centrally located lug bolt apertures formed in the wheel cover which correspond to the lug bolt apertures of the wheel, and a plurality of decorative openings formed in the wheel cover and spaced radially outwardly from the lug bolt apertures, which plurality of openings correspond to the plurality of openings formed in the wheel cover; applying a primary adhesive pattern to at least one of the outboard surface of the wheel or the inner surface of the wheel cover, said primary adhesive pattern defining areas that will be hollow when the wheel cover and the wheel are bonded together by the primary adhesive pattern; applying an auxiliary adhesive pattern to at least one of the outboard surface of the wheel or the inner surface of the wheel cover, said auxiliary adhesive pattern consisting of discrete beads of adhesive that will be positioned in the hollow areas defined by the primary adhesive pattern; and assembling the wheel cover to the wheel to cause the adhesive to contact both the outboard surface of the wheel and the inner surface of the wheel cover and thereby enable the primary adhesive pattern to secure the wheel cover to the wheel. 17. A method of reducing hollow sounds in wheel assemblies according to claim 16, wherein the discrete beads of adhesive of the auxiliary pattern have opposite terminal ends that are non-connected to the primary adhesive pattern. 18. A method of reducing hollow sounds in wheel assemblies according to claim 16, wherein the discrete beads of adhesive of the auxiliary pattern have at least one opposite terminal end that is connected to the primary adhesive pattern. 19. A method of reducing hollow sounds in wheel assemblies according to claim 16, wherein the hollow areas defined by the primary adhesive pattern include openings in the primary adhesive pattern through which ambient fluids can freely enter and exit. 20. A method of reducing hollow sounds in wheel assemblies according to claim 16, wherein the discrete beads of adhesive of the auxiliary adhesive pattern are linear. 21. A method of reducing hollow sounds in wheel assemblies according to claim 16, wherein the discrete beads of adhesive of the auxiliary adhesive pattern have curved portions. | TECHNICAL FIELD The present invention relates to vehicle wheels that have decorative wheel covers secured over the wheel for aesthetic purposes. More specifically, the present invention relates to methods for adhesively securing decorative wheel covers to wheels which methods involve the use of primary adhesive patterns together with auxiliary adhesive patterns that provide noise dampening functions. BACKGROUND ART Wheel assemblies that utilize wheel appliqués to decorate the external or outboard surfaces of plain steel wheels are well known and are far less expensive to produce than decorative wheels that have to be formed and finished. Wheel appliqués can be secured to wheels by various mechanical engaging structures and/or by adhesives. U.S. Pat. No. 5,664,845 to Maloney et al. discloses a vehicle wheel cover retention system in which the annular lip of the wheel cover is configured to spring outwardly into a groove provided in the inner surface of the wheel. U.S. Pat. No. 5,595,423 to Heck et al. discloses a vehicle wheel cover retention system in which the outer edge of the wheel cover is deformed to cover the outer peripheral edge of the outboard bead seat retaining flange of the wheel. Both U.S. Pat. No. 5,664,845 to Maloney et al. and U.S. Pat. No. 5,595,423 to Heck et al. utilize an adhesive in cooperation with their respective mechanical engaging structures. Many wheel assemblies include decorative wheel covers that are adhesively attached to underlying wheels. U.S. Pat. No. 3,669,501 to Derleth discloses the use of a foamable adhesive that is used to secure a decorative cover to a wheel. The decorative cover in Derleth is configured to have variations in contour in a direction transverse to the axis of the wheel which exceed the variations in the rim and/or disc contour of the wheel, which variations would be extremely difficult and expensive, if not impossible, to stamp or draw in the disc of the wheel. During assembly, a foamable adhesive is coated on the wheel, and the decorative cover is then quickly clamped to the wheel before the adhesive begins to foam. As the adhesive foams, void spaces between the wheel and cover are filled with the foamable adhesive. Turbine openings are a necessary element in today's wheel systems in providing proper cooling to brake systems. In addition, the aesthetics of endless configurations of turbine openings add individuality and style to vehicle wheels. The inclusion of turbine openings in wheels and wheel covers creates problems with the use of adhesives. In order to use foamable adhesives, it is necessary to use some additional structure to seal large openings such as turbine openings to prevent the foamable adhesive from escaping through the openings rather than spread evenly or completely between a wheel and wheel cover. U.S. Pat. Nos. 5,368,370 and 5,461,779 to Beam disclose an ornamental appliqué formed on a uniform thickness of stainless steel sheet stock that requires attachment to a wheel by the use of a full surface curable adhesive uniformly deposited between the stainless steel cover and a mechanical locking arrangement. The mechanical locking arrangement consists of an undercut in the rim of the wheel into which the cover nests and a hole in the wheel aligned with a hole in the appliqué wherein a lug stud is permanently attached to create a mechanical lock that, according to Beam's teachings, spreads the curable adhesive into a uniform layer and compresses the ornamental appliqué to the wheel until the adhesive cures. Beam's teachings exemplify an early concern that adhesives used to secure wheel covers onto wheel assemblies had to be applied as continuous coatings between the wheel covers and wheels in order to secure the attachment and prevent moisture and dirt from entering any gaps between the wheel covers and wheels and causing corrosion to develop. There are some restrictions on the types of adhesives that can be used to secure wheel covers to wheels and considerations on how to apply some adhesives. Suitable adhesives have to withstand the high temperatures generated by tires, wheels and breaking systems. In the case of air-cured and moisture-cured adhesives, it has been discovered that the use of continuous coatings of the adhesives between wheel covers and a wheels adversely effects cure time. U.S. Pat. No. 5,597,213 to Chase exemplifies the use beads of adhesive that are provide in parallel as separated lines of adhesive rather than a continuous layer to create voids so as to reduce the amount of curing time of the adhesive and thereby reduce manufacturing time and costs. In Chase, air between the lines of adhesives is “captured” between the overlay and the wheel to assist in curing the adhesive. In the case of adhesives that are moisture-cured, Chase proposes introducing high humidity air into the assembly process and the technique of selective application of the adhesive can be utilized to establish voids between lines of adhesive that serve to entrap moisture laden air which further enhances cure times and reduces overall costs of the manufacturing process. U.S. Pat. No. 6.00,158 to Maloney et al. teaches a vehicle cover retention system and method for producing the same. Maloney et al. applies an adhesive in a pattern, which when pressed between the wheel cover and wheel can fill less that the entire gap between the wheel cover and wheel, but nevertheless is effective to prevent water, mud and debris from entering into any voids or gaps between the wheel cover and wheel. Adhesive patterns exemplified in FIG. 6 of Maloney et al. are designed to establish seals that prevent water, mud and debris from entering any voids, gaps or other spaces between the wheel covers and the wheels. The concern remains that if such water, mud and debris enter any voids, gaps or other spaces between the wheel covers and the wheels, it will eventually cause corrosion to occur between the wheel covers and wheel and result in detachment of the wheel cover or at least an unsightly appearance. The present invention provides a method for adhesively securing decorative wheel covers to wheels which methods involve the use of primary adhesive patterns and auxiliary adhesive patterns that are not found in the prior art. DISCLOSURE OF THE INVENTION According to various features, characteristics and embodiments of the present invention which will become apparent as the description thereof proceeds, the present invention provides a method of securing a wheel cover to a wheel to form a wheel assembly which method comprises: providing a wheel having an outboard surface with a plurality of centrally located lug bolt apertures formed in the outboard surface and a plurality of openings formed in the outboard surface and spaced radially outwardly from the lug bolt apertures; providing a wheel cover having an inner surface and a plurality of centrally located lug bolt apertures formed in the wheel cover which correspond to the lug bolt apertures of the wheel, and a plurality of decorative openings formed in the wheel cover and spaced radially outwardly from the lug bolt apertures, which plurality of openings correspond to the plurality of openings formed in the wheel cover; applying a primary adhesive pattern to at least one of the outboard surface of the wheel or the inner surface of the wheel cover; applying an auxiliary adhesive pattern to at least one of the outboard surface of the wheel or the inner surface of the wheel cover; and assembling the wheel cover to the wheel to cause the primary and auxiliary adhesive patterns to contact both the outboard surface of the wheel and the inner surface of the wheel cover and thereby enable the adhesive pattern to secure the wheel cover to the wheel and define a space between the wheel cover and wheel which is not filled with adhesive, the primary adhesive pattern being sufficient to secure the wheel covet to the wheel and comprising a configuration of beads of adhesive that do not fill the entire space between the wheel cover and the wheel, the auxiliary adhesive pattern being insufficient to secure the wheel cover to the wheel and comprising a configuration of discrete beads of adhesive that are provided in portions of the space between the wheel cover and the wheel which are hollow. The present invention further provides a wheel assembly which comprises: a wheel having an outboard surface with a plurality of centrally located lug nut apertures formed in the outboard surface and a plurality of openings formed in the outboard surface and spaced radially outwardly from the lug nut apertures; a wheel cover having an inner surface and a plurality of centrally located lug nut apertures formed in the wheel cover which are aligned with the lug nut apertures of the wheel, and a plurality of decorative openings formed in the wheel cover and spaced radially outwardly from the lug nut apertures, which plurality of openings are aligned with the plurality of openings formed in the wheel cover; a cured primary adhesive pattern between the wheel and wheel cover which bonds the wheel and wheel cover together with a space between the wheel and wheel cover which space is not filled with the cured primary adhesive; and a cured auxiliary adhesive pattern that is insufficient to secure the wheel cover to the wheel and comprises a configuration of discrete beads of adhesive that are provided in portions of the space between the wheel cover and the wheel which are hollow. The present invention further provides a method of reducing hollow sounds in wheel assemblies which method comprises: providing a wheel having an outboard surface with a plurality of centrally located lug bolt apertures formed in the outboard surface and a plurality of openings formed in the outboard surface and spaced radially outwardly from the lug bolt apertures; providing a wheel cover having an inner surface and a plurality of centrally located lug bolt apertures formed in the wheel cover which correspond to the lug bolt apertures of the wheel, and a plurality of decorative openings formed in the wheel cover and spaced radially outwardly from the lug bolt apertures, which plurality of openings correspond to the plurality of openings formed in the wheel cover; applying a primary adhesive pattern to at least one of the outboard surface of the wheel or the inner surface of the wheel cover, the primary adhesive pattern defining areas that will be hollow when the wheel cover and the wheel are bonded together by the primary adhesive pattern; applying an auxiliary adhesive pattern to at least one of the outboard surface of the wheel or the inner surface of the wheel cover, the auxiliary adhesive pattern consisting of discrete beads of adhesive that will be positioned in the hollow areas defined by the primary adhesive pattern; and assembling the wheel cover to the wheel to cause the adhesive to contact both the outboard surface of the wheel and the inner surface of the wheel cover and thereby enable the primary adhesive pattern to secure the wheel cover to the wheel. BRIEF DESCRIPTION OF DRAWINGS The present invention will be described with reference to the attached drawings which are given as non-limiting examples only, in which: FIG. 1 is a perspective view of a wheel assembly according to one embodiment of the present invention. FIG. 2 is an exploded perspective view of the wheel assembly of FIG. 1. FIGS. 3a-3h are examples of prior art adhesive patterns used in wheel assemblies. FIGS. 4a and 4b are exemplary adhesive patterns according to embodiments of the present invention that do not seal off areas between a wheel cover and a wheel. FIGS. 5a-5c are exemplary adhesive patterns according to the present invention that include primary and auxiliary adhesive patterns. FIG. 6 is a cross-sectional view of a wheel assembly according to one embodiment that includes an adhesive pattern similar to that shown in FIG. 5a taken along section line VI-VI. BEST MODE FOR CARRYING OUT THE INVENTION FIG. 1 is a perspective view of a wheel assembly according to one embodiment of the present invention. The wheel assembly which is generally identified by reference numeral 1 includes a wheel 2 that can be made of aluminum, magnesium, steel, or other material conventionally used for manufacturing vehicle wheels. A decorative wheel cover 3 is bonded to the otherwise outer exposed surface 4 (See FIG. 2) of wheel 2. The wheel cover 3 is a solid panel of a high-impact plastic that has a high temperature resistance or can be a thin metallic panel such as stainless steel that, in either case has a finished outer surface that can be painted, textured or plated, e.g. chrome plated as desired. An advantage of using a high-impact plastic material such as a combination of polycarbonate and ABS is that wheel covers 3 made from such materials can be injection molded. Wheel 2 is of the type which includes a small central opening 5 in the wheel hub 6 and a plurality of exposed lug bolt apertures 7 arranged in a circular pattern and spaced for the particular vehicle on which wheel assembly 1 is to be employed. Opening 5 will typically be enclosed by a relatively small cap while the lug nuts themselves (not shown) are exposed once the wheel assembly 1 is mounted to a vehicle. Wheel cover 3 has a geometry and contour which substantially conforms to that of wheel 2, namely, an outer peripheral edge 8 which matingly fits within rim 9 of wheel 2. Spokes 11 extend radially outwardly from the center hub opening 5′ which correspond in size, shape and location to the spokes 10 on wheel 2. Between the spokes 11 of wheel cover 3 are decorative openings or windows 12 that are shaped to conform to corresponding decorative openings or windows 13 in wheel 2. The central hub area surrounding central opening 5′ of wheel cover 3 also includes a plurality of lug bolt receiving openings 15 which align with and are received within openings 7 in wheel 2 when the wheel cover 3 is position on the wheel 2. The central opening 5′ of the wheel cover 3 is aligned with opening 5 in wheel hub 6, as best seen in FIG. 1. When the wheel cover 3 is bonded to wheel 2, the wheel cover 3 appears as an integral outer surface of the wheel 1, as depicted in FIG. 1. The wheel cover 3 is bonded to wheel 2 by a primary adhesive pattern that is configured to securely bond the wheel cover 3 to the outboard face of the wheel 2. The primary adhesive pattern can include any known adhesive pattern that bonds the wheel cover 3 to the outboard face of the wheel 2 or an adhesive pattern, as discussed below, which is configured to avoid sealing off areas between a wheel cover and a wheel. In addition to the primary adhesive pattern, the present invention includes an auxiliary adhesive pattern that comprises discrete lines or beads of adhesive which are not provided to secure a wheel cover to a wheel, but rather are provided to prevent portions of the wheel cover which are not immediately secured to the wheel by the primary adhesive patterns from sounding hollow. One of the advantages associated with using adhesive patterns rather than using a continuous layer of adhesive between a wheel cover and a wheel is that less adhesive can be used. Adhesive patterns used by the prior art as exemplified in FIGS. 3a-3h and those exemplified in FIGS. 4a-4c, include areas between beads or lines of adhesive where the wheel covers are not immediately secured to the wheels. Depending on the size of these non-immediately secured areas they can sound hollow when the wheel cover is hit or tapped or they can vibrate. The auxiliary adhesive patterns of the present invention include discrete lines or beads of adhesive that extend into at least partially into the areas that are not immediately secured by the primary adhesive patterns so as to prevent these areas from sounding hollow or from vibrating. As discussed in detail below, the discrete lines or beads of adhesive of the auxiliary adhesive patterns can have one or more terminal end(s) that is/are not connected to any portion of the primary adhesive pattern. FIGS. 3a-3h are examples of prior art adhesive patterns used in wheel assemblies. Throughout FIGS. 3a-3b common reference numerals have been used to identify similar elements where convenient. FIG. 3a depicts an adhesive pattern that is formed from an unfoamed adhesive which is applied between wheel cover 16 and wheel 17. The adhesive pattern includes a bead 20 of adhesive that extends around the outer perimeter of the assembly, beads 21 of adhesive that surround the edge of each of the turbine openings 18, and a bead 22 of adhesive that collectively surrounds the grouping of lug bolt openings 19. FIG. 3b is an adhesive pattern that is similar to that shown in FIG. 3a. However, in FIG. 3b, a foaming adhesive is utilized. As can be seem from a comparison between FIGS. 3c and 3d, the foaming adhesive will spread to cover a most of the space between the wheel cover 17 and the wheel 16 when the wheel cover 17 and wheel 16 are pressed together. FIG. 3c depicts an adhesive pattern that is formed from a foaming adhesive which is applied between wheel cover 17 and wheel 16. The adhesive pattern shown in FIG. 3c includes a single bead 23 of adhesive that is applied along the central portion of the spokes 24, a single bead 25 of adhesive that extends around the outer perimeter of the assembly, and a bead 26 of adhesive that collectively surrounds the grouping of lug bolt openings 19. FIG. 3d depicts the manner in which the adhesive pattern of the foaming adhesive 27 of FIG. 3c spreads to cover up to 95% of the surface area between the wheel cover 17 and the wheel 16, when the wheel cover 17 and wheel 16 are pressed together. FIG. 3e depicts an adhesive pattern that includes individual beads 30 of adhesive that surround each lug bolt opening 19, a bead 31 of adhesive that extends around the outer perimeter of the assembly and individual beads 32 of adhesive that surround each of the turbine openings 18. FIG. 3f depicts an adhesive pattern that includes an inner circle of adhesive 34, and outer circle of adhesive 35, and a number of radial lines of adhesive 36. The inner circle of adhesive 34 seals off a central hub opening 36 and lug bolt openings 19. The inner circle of adhesive 34, outer circle of adhesive 35, and radial lines of adhesive 36 effectively seal off the decorative openings or windows 18. When the wheel cover 17 is pressed onto the wheel (not shown), the adhesive spreads between the wheel cover 17 and wheel. FIG. 3g depicts an adhesive pattern that includes a bead 40 of adhesive that surrounds the outer periphery of the assembly, a bead 41 of adhesive in the from of a circle that collectively surrounds the lug bolt receiving holes 19 and separate beads 42 of adhesive that surround each of the turbine openings or decorative windows 18. FIG. 3h depicts an adhesive pattern that includes an a bead 45 of adhesive that is intermittently provided around an outer perimeter of the assembly, individual beads 46 of adhesive that surround each opening 18, and beads 47 of adhesive that are provided between openings 18. The prior art adhesive patterns depicted in FIGS. 3a-3h are each configured and applied to seal the gap between the wheel covers and wheels to keep dirt, water and other debris from getting between the wheel covers and wheels. FIGS. 4a and 4b are exemplary adhesive patterns according to one embodiment that do not seal off areas between a wheel cover and a wheel. FIGS. 4a and 4b (and FIGS. 5a-5c) illustrate adhesive patterns that can be provided on either the outboard surface of a wheel or on an inner surface of a wheel cover. For purposes of describing the present invention, it will be assumed that FIGS. 4a and 4b (and FIGS. 5a-5c) illustrate adhesive patterns that are provided on the outboard surface of a wheel and that the corresponding wheel cover includes decorative openings or windows, lug bolt apertures and a central hub opening that are sized, shaped and positioned complementarily to the decorative openings or windows, lug bolt apertures and central hub openings of the wheel. The adhesive pattern depicted in FIG. 4a includes a circular bead or line of adhesive 50 that extends along the outer peripheral edge of the wheel 51 and a series of adhesive beads or lines 52 that loop inward from the circular bead or line of adhesive 50. The loop beads or lines of adhesive 52 are shown as having common or overlapping leg portions 53 and apexes 54 that are positioned between the decorative openings or windows 55 and the lug bolt openings 56. It is noted that in FIG. 4a there are no areas surrounded by adhesive beads or lines that are completely sealed, i.e., that do not contain either a decorative opening or window 55 or the lug bolt and central hub openings 56 and 57. Accordingly, when the adhesive pattern shown in FIG. 4a is provided between a wheel cover and a wheel and the two are pressed toward one another, there are no sealed pockets defined by the adhesive pattern in which air can become entrapped and compressed. The adhesive pattern depicted in FIG. 4a allows all the air between the wheel cover and wheel to escape through the decorative openings or windows 55, the lug bolt openings 56 and/or the central hub opening 57. The adhesive pattern depicted in FIG. 4b includes an outer circular bead or line of adhesive 60 that extends along the outer peripheral edge of the wheel 61 and an inner circular bead or line of adhesive 62 that surrounds the lug bolt openings 63. In addition, the adhesive pattern depicted in FIG. 4b includes a single bead or line of adhesive 64 between each adjacent pair or the decorative openings of windows 65 that extends radially between the outer circular bead or line of adhesive 60 and the inner circular bead or line of adhesive 62. It is noted that in FIG. 4b there are no areas surrounded by adhesive beads or lines that are completely sealed, i.e., that do not contain either a decorative opening or window 65 or the lug bolt and central hub openings 63 and 67. Accordingly, when the adhesive pattern shown in FIG. 4b is provided between a wheel cover and a wheel and the two are pressed toward one another, there are no sealed pockets defined by the adhesive pattern in which air can become entrapped and compressed. The adhesive pattern depicted in FIG. 4b allows all the air between the wheel cover and wheel to escape through the decorative openings or windows 65, the lug bolt openings 63 and/or the central hub opening 67. It is to be understood that the adhesive patterns depicted in FIGS. 3a-3h are non-limiting examples of adhesive patterns that are configured to seal dirt, water and other debris from entering between wheel covers and wheels. Likewise, the adhesive patterns depicted in FIGS. 4a and 4b are non-limiting examples of adhesive patterns that do not define sealed pockets in which air can be trapped when the wheel covers and wheels are pressed together. The adhesive patterns useful as the primary adhesive patterns of the present invention include those exemplified by FIGS. 3a-3h that are configured to seal dirt, water and other debris from entering between wheel covers and wheels, and those exemplified by FIGS. 4a and 4b that do not define sealed pockets in which air can be trapped when the wheel covers and wheels are pressed together. The primary adhesive patterns used in the present invention do not include adhesive patterns that form a continuous adhesive layer between the wheel covers and the wheels. Certain embodiments of the present invention use primary adhesive patterns are configured to avoid establishing the type of seals that are conventionally provided to prevent water, mud and debris from entering any voids, gaps or other spaces between the wheel covers and the wheels. Such adhesive patterns which are useful for purposes of the present invention are a departure from more conventional adhesive patterns that are configured to establish seals that prevent water, mud and debris from entering any voids, gaps or other spaces between the wheel covers and the wheels. More conventional adhesive patterns address concerns that if such water, mud and debris enter any voids, gaps or other spaces between the wheel covers and the wheels, it will eventually cause corrosion to occur between the wheel covers and wheels and result in detachment of the wheel covers or at least an unsightly appearance. However, such prior art adhesive patterns often fail and expedite the deterioration of wheel assemblies, because the beads or lines of adhesive are often breached during assembly as air trapped within the sealed areas becomes compressed when the wheel covers and wheels are pressed together and breaches portions of the beads or lines of adhesive which forms the sealed pocket. As a result, the goal to provide a seal and prevent water, mud and other debris from entering between the cover and the outboard facing surface of the wheel is not met, but rather spoiled. Such a problem is common in wheel assemblies that use adhesive patterns that provide beads or lines of adhesive around the outer peripheral edge of the wheel cover and around each opening, including vent/decorative openings, lug bolt openings (separately or collectively) and wheel hub openings. Such adhesive patterns which are intentionally designed to seal off the gap between the wheel covers and wheel around the outer peripheral edge and openings ironically create pockets of air that becomes pressurized upon assembly and defeats the goal of providing a seal. The breached areas of the adhesive beads or lines are typically sufficiently small so that water, mud and other debris that passes through the breached areas becomes effectively trapped within pockets that, except for the breached areas, are otherwise sealed. For example, water that enters the pockets through the breached areas can only pass out of the pockets if the water “finds” the breached areas again. This may be difficult when the wheel assembly rotates and the orientation of the pockets and breached areas keep changing. FIGS. 5a-5c are exemplary adhesive patterns which include both primary adhesive patterns and the auxiliary adhesive patterns according to the present invention. FIG. 5a depicts an embodiment of the present invention which utilizes a primary adhesive pattern that is similar to that shown in FIG. 4a in which the primary adhesive pattern does not seal off areas between a wheel cover and a wheel. The primary adhesive pattern depicted in FIG. 5a includes a circular bead or line of adhesive 70 that extends along the outer peripheral edge of the wheel 71 and a series of adhesive beads or lines 72 that loop inward from the circular bead or line of adhesive 70. The loop beads or lines of adhesive 72 are shown as having common or overlapping leg portions 73 and apexes that are positioned between the decorative openings or windows 74 and the lug bolt openings 75. The auxiliary adhesive pattern in FIG. 5a comprises discrete beads or lines of adhesive 76 that extend radially inward from the apex of each of the loop beads or lines 72 of adhesive of the primary adhesive pattern. The discrete beads or lines of adhesive 76 of the auxiliary adhesive pattern shown in FIG. 5a include free terminal ends that are near the lug bolt openings 75 and opposed bases which connect to the apexes of the loop beads or lines 72. As depicted in FIG. 5a, the bases of the discrete beads or lines of adhesive 76 of the auxiliary adhesive pattern connect to the apexes of the loop beads or lines 72 by curved segments which allow the auxiliary adhesive pattern to be formed in a continuous manner while forming the primary adhesive pattern, i.e. without interrupting the continuous feed of adhesive from an automated. FIG. 5b depicts an embodiment of the present invention which utilizes a primary adhesive pattern that is similar to that shown in FIG. 4b in which the primary adhesive pattern does not seal off areas between a wheel cover and a wheel. The primary adhesive pattern depicted in FIG. 5b includes an outer circular bead or line of adhesive 80 that extends along the outer peripheral edge of the wheel 81 and an inner circular bead or line of adhesive 82 that surrounds the lug bolt openings 83. In addition, the primary adhesive pattern depicted in FIG. 5b includes a single bead or line of adhesive 84 between each adjacent pair or the decorative openings of windows 85 that extends radially between the outer circular bead or line of adhesive 80 and the inner circular bead or line of adhesive 82. The auxiliary adhesive pattern in FIG. 5b comprises discrete beads or lines of adhesive 86 that extend radially and are positioned between the beads or lines of adhesive 84 of the primary adhesive and the adjacent decorative openings of windows 85. FIG. 5c depicts an embodiment of the present invention which utilizes a primary adhesive pattern that includes a circular bead or line of adhesive 90 that extends along the outer peripheral edge of the wheel 91 and a series of adhesive beads or lines 92 that have trapezoid shapes which extend inward from the circular bead or line of adhesive 90. The trapezoidal shaped beads or lines of adhesive 92 are shown as having common or overlapping leg portions 93. The auxiliary adhesive pattern in FIG. 5c comprises discrete beads or lines of adhesive 94 that extend radially inward in alignment with the legs 93 of the trapezoidal shaped beads or lines of adhesive 92. The discrete beads or lines of adhesive 94 of the auxiliary adhesive pattern shown in FIG. 5a include opposite free terminal ends with the inner most free terminal end extending between pairs of lug bolt openings 95. It is to be understood that the auxiliary adhesive patterns depicted in FIGS. 5a-5c are non-limiting examples of auxiliary adhesive patterns that can be used in combination with primary adhesive patterns according to the present invention. From the examples presented in FIGS. 5a-5c it is to be understood that the auxiliary adhesive patterns comprise discrete lines or beads of adhesive that extend at least partially into the areas that are not immediately secured by the primary adhesive patterns so as to prevent these areas from sounding hollow or from vibrating. As depicted in FIGS. 5a-5c, the discrete lines or beads of adhesive of the auxiliary adhesive patterns can have one or more terminal end(s) that is/are not connected to any portion of the primary adhesive pattern. In further embodiments, both ends of the discrete beads or lines of the adhesive of the auxiliary pattern can be connected to portions of the primary adhesive pattern; however, more desirable embodiments of the present invention do not include sealed pockets defined by any combination of the primary and auxiliary adhesive patterns in which air can become entrapped and compressed. It is also noted that whereas the auxiliary adhesive beads or lines are depicted as being substantially linear, they could also be T-shaped, I-shaped, L-shaped, V-shaped, X-shaped, +-shaped, curved, etc. or have any shape, with shapes that form sealed pockets between the wheel cover and wheel, being acceptable, but less desirable for the reasons discussed above. According to the present invention neither the primary adhesive patterns nor the auxiliary adhesive patterns alone or in combination are applied and/or configured to provide a continuous layer of adhesive between the wheel covers and the wheels. FIG. 6 is a cross-sectional view of a wheel assembly according to the present invention taken along section line VI-VI in FIG. 5a. In FIG. 6 the wheel has a recessed central portion 100 which is not shown in FIG. 5a. The wheel cover 101 in shown as being secured to wheel 102 by primary adhesive areas 103, 104 which correspond to the circular bead or line of adhesive 70 that extends along the outer peripheral edge of the wheel 101 and the loop beads or lines of adhesive 72 respectively. The decorative openings or windows 74 and lug bolt openings 75 in the wheel cover 101 are positioned over the decorative openings or windows 74′ and lug bolt openings 75′ in the wheel 102. The primary adhesive portion 103 is near the outboard bead seat retaining flange 106 of the wheel assembly 107. In FIG. 5a an auxiliary adhesive portion is identified by reference numeral 105 which corresponds to the discrete bead or line of adhesive 76 in FIG. 5a. It is to be understood that the adhesive patterns of the present invention can be used in conjunction with wheel assemblies that use full or partial wheel covers, including wheel covers that extend over and cover the outboard bead seat retaining flange of wheels. In addition, although not shown, the adhesive patterns of the present invention can be used in conjunction with various known temporary or permanent mechanical engaging structures. The present invention can use any conventional adhesive material. Moreover, the primary and auxiliary adhesive patterns can be composed of the same or different adhesive materials. Since the auxiliary adhesive patterns are not required or relied upon to secure the wheel covers to the wheels, they can be made from sound dampening materials that can cure to rigid or non-rigid states, but which do not have extremely strong adhesive properties and/or tensile strengths. However, foamable adhesives should generally be avoided, particularly when the outboard surface of the wheel and the wheel cover have similar contoured shapes. The adhesive patterns of the present invention that do not create sealed pockets between the wheel covers and wheels are particularly suitable for use in conjunction with air and/or moisture cured adhesives since the adhesive patterns allow air and moisture to reach the adhesive throughout the adhesive patterns. Although the present invention has been described with reference to particular means, materials and embodiments, from the foregoing description, one skilled in the art can easily ascertain the essential characteristics of the present invention and various changes and modifications can be made to adapt the various uses and characteristics without departing from the spirit and scope of the present invention as described above. | <SOH> BACKGROUND ART <EOH>Wheel assemblies that utilize wheel appliqués to decorate the external or outboard surfaces of plain steel wheels are well known and are far less expensive to produce than decorative wheels that have to be formed and finished. Wheel appliqués can be secured to wheels by various mechanical engaging structures and/or by adhesives. U.S. Pat. No. 5,664,845 to Maloney et al. discloses a vehicle wheel cover retention system in which the annular lip of the wheel cover is configured to spring outwardly into a groove provided in the inner surface of the wheel. U.S. Pat. No. 5,595,423 to Heck et al. discloses a vehicle wheel cover retention system in which the outer edge of the wheel cover is deformed to cover the outer peripheral edge of the outboard bead seat retaining flange of the wheel. Both U.S. Pat. No. 5,664,845 to Maloney et al. and U.S. Pat. No. 5,595,423 to Heck et al. utilize an adhesive in cooperation with their respective mechanical engaging structures. Many wheel assemblies include decorative wheel covers that are adhesively attached to underlying wheels. U.S. Pat. No. 3,669,501 to Derleth discloses the use of a foamable adhesive that is used to secure a decorative cover to a wheel. The decorative cover in Derleth is configured to have variations in contour in a direction transverse to the axis of the wheel which exceed the variations in the rim and/or disc contour of the wheel, which variations would be extremely difficult and expensive, if not impossible, to stamp or draw in the disc of the wheel. During assembly, a foamable adhesive is coated on the wheel, and the decorative cover is then quickly clamped to the wheel before the adhesive begins to foam. As the adhesive foams, void spaces between the wheel and cover are filled with the foamable adhesive. Turbine openings are a necessary element in today's wheel systems in providing proper cooling to brake systems. In addition, the aesthetics of endless configurations of turbine openings add individuality and style to vehicle wheels. The inclusion of turbine openings in wheels and wheel covers creates problems with the use of adhesives. In order to use foamable adhesives, it is necessary to use some additional structure to seal large openings such as turbine openings to prevent the foamable adhesive from escaping through the openings rather than spread evenly or completely between a wheel and wheel cover. U.S. Pat. Nos. 5,368,370 and 5,461,779 to Beam disclose an ornamental appliqué formed on a uniform thickness of stainless steel sheet stock that requires attachment to a wheel by the use of a full surface curable adhesive uniformly deposited between the stainless steel cover and a mechanical locking arrangement. The mechanical locking arrangement consists of an undercut in the rim of the wheel into which the cover nests and a hole in the wheel aligned with a hole in the appliqué wherein a lug stud is permanently attached to create a mechanical lock that, according to Beam's teachings, spreads the curable adhesive into a uniform layer and compresses the ornamental appliqué to the wheel until the adhesive cures. Beam's teachings exemplify an early concern that adhesives used to secure wheel covers onto wheel assemblies had to be applied as continuous coatings between the wheel covers and wheels in order to secure the attachment and prevent moisture and dirt from entering any gaps between the wheel covers and wheels and causing corrosion to develop. There are some restrictions on the types of adhesives that can be used to secure wheel covers to wheels and considerations on how to apply some adhesives. Suitable adhesives have to withstand the high temperatures generated by tires, wheels and breaking systems. In the case of air-cured and moisture-cured adhesives, it has been discovered that the use of continuous coatings of the adhesives between wheel covers and a wheels adversely effects cure time. U.S. Pat. No. 5,597,213 to Chase exemplifies the use beads of adhesive that are provide in parallel as separated lines of adhesive rather than a continuous layer to create voids so as to reduce the amount of curing time of the adhesive and thereby reduce manufacturing time and costs. In Chase, air between the lines of adhesives is “captured” between the overlay and the wheel to assist in curing the adhesive. In the case of adhesives that are moisture-cured, Chase proposes introducing high humidity air into the assembly process and the technique of selective application of the adhesive can be utilized to establish voids between lines of adhesive that serve to entrap moisture laden air which further enhances cure times and reduces overall costs of the manufacturing process. U.S. Pat. No. 6.00,158 to Maloney et al. teaches a vehicle cover retention system and method for producing the same. Maloney et al. applies an adhesive in a pattern, which when pressed between the wheel cover and wheel can fill less that the entire gap between the wheel cover and wheel, but nevertheless is effective to prevent water, mud and debris from entering into any voids or gaps between the wheel cover and wheel. Adhesive patterns exemplified in FIG. 6 of Maloney et al. are designed to establish seals that prevent water, mud and debris from entering any voids, gaps or other spaces between the wheel covers and the wheels. The concern remains that if such water, mud and debris enter any voids, gaps or other spaces between the wheel covers and the wheels, it will eventually cause corrosion to occur between the wheel covers and wheel and result in detachment of the wheel cover or at least an unsightly appearance. The present invention provides a method for adhesively securing decorative wheel covers to wheels which methods involve the use of primary adhesive patterns and auxiliary adhesive patterns that are not found in the prior art. | <SOH> BRIEF DESCRIPTION OF DRAWINGS <EOH>The present invention will be described with reference to the attached drawings which are given as non-limiting examples only, in which: FIG. 1 is a perspective view of a wheel assembly according to one embodiment of the present invention. FIG. 2 is an exploded perspective view of the wheel assembly of FIG. 1 . FIGS. 3 a - 3 h are examples of prior art adhesive patterns used in wheel assemblies. FIGS. 4 a and 4 b are exemplary adhesive patterns according to embodiments of the present invention that do not seal off areas between a wheel cover and a wheel. FIGS. 5 a - 5 c are exemplary adhesive patterns according to the present invention that include primary and auxiliary adhesive patterns. FIG. 6 is a cross-sectional view of a wheel assembly according to one embodiment that includes an adhesive pattern similar to that shown in FIG. 5 a taken along section line VI-VI. detailed-description description="Detailed Description" end="lead"? | 20040301 | 20060411 | 20050901 | 96078.0 | 1 | BELLINGER, JASON R | SOUND DAMPENING ADHESIVE PATTERNS FOR VEHICLE WHEEL ASSEMBLIES | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,790,664 | ACCEPTED | Dissolving gel for cured polysulfide resins | A cured resin dissolving composition comprising a cellulosic gelling agent prepared in n,n-dimethylacetamide, known for its high penetration and solvency to polar resins, with a glycol-ether co-solvent, 1,8-diazabicyclo(5.4.0)undec-7-ene as a soluble amine, and a surfactant. The mixture of components form a gel-form composition while maintaining high dissolution character for cured polysulfide resins. The optimum thickness of the gel form is dependent upon the amount of the cellulose gelling agent present in the mixture. The product may be used to remove coatings and sealants present on vertical and horizontal surfaces and hard to reach areas commonly encountered when performing maintenance on aviation fuel tanks and similar equipment. Once the system has been in contact with the resin and dissolution has been allowed for a period of time, the reacted material may be wiped away or can be easily rinsed with water, an alcohol, or another hydrophilic rinse. The invention has application in a wide range of industries where removal of cured resin is desired either in performing maintenance or for selective cleaning. Examples of industry applications include removing polysulfide coatings and sealants in aerospace, automotive, and construction. | 1. A composition effective for dissolving a cured polysulfide resin from vertical and overhead surfaces comprising: (a) a solvent exhibiting a high penetration and solvency capacity for polar resins such as polysulfide; (b) a co-solvent that is compatible with the primary solvent, exhibits dispersion capacity, and contains a minimum amount of alcoholic (e.g., —OH) character needed for enhancing the action of the gelling agent; (c) a soluble amine component exhibiting a high pKa value ≧12; and (d) a gelling agent. 2. The composition of claim 1 which includes a compatible surfactant. 3. The composition of claim 2 wherein “a” is n,n-dimethylacetamide (DMAC). 4. The composition of claim 3 wherein “b” is tripropyleneglycol monomethylether (TPM). 5. The composition of claim 4 wherein “c” is 1,8-diazabicyclo(5.4.0)undec-7-ene (DBU). 6. The composition of claim 5 wherein “d” is hydroxypropylcellulose. 7. The composition of claim 6 wherein the viscosity of the final product is controlled to 25,000±10,000 cps and 50,000±20,000 cps, tested at <3 hrs. of preparation and at approximately 72 hrs., respectively. 8. A process for removing cured polymer resin from the surface of vertical or horizontal substrates containing a layer of cured resin with the composition of claims 1 and 6, allowing sufficient lapse of time to permit the dissolution of the resin and removing the dissolved resin from the substrate by wiping or with a rinse. 9. The process of claim 8 wherein the cured resin to be removed from the substrate is a cured polysulfide. | This invention relates to a gel-form composition suitable for application on vertical and overhead surfaces that will effectively revert and dissolve cured polymeric compositions and in particular polysulfide substances contained on said surfaces. BACKGROUND OF THE INVENTION Polysulfide-based resins are used widely in the protection and sealing of components and hardware in many industries that include aviation. In fact, polysulfide-based resins are the primary products of choice for sealing fuel tank compartments. Within aviation, fuel tank sealants are highly regulated by the federal government to provide specific performance qualities. These formulations have been held constant over many decades and are used in many aircraft from small recreational to commercial airlines. The application and maintenance of these materials are also deemed to be regulated and expected to be held constant over many years. When it becomes necessary to perform repair and maintenance on the polysulfide resin, it is most common to start with complete removal of the material from the area in question. Removal of the resin typically includes scraping and mechanical abrasion, resulting in significant damage to the underlying substrate. When substrate damage occurs, as is commonly the case, the surfaces must be reconditioned, requiring the use of several steps and significantly increasing the resources and cost of the original task. Attempts to use solvents render it impossible to control the cleaner to select areas or to vertical and overhead structures. When this fails, the operator typically defaults to the option of using mechanical action. Therefore, current practice in the maintenance and repair of polysulfide resin is labor-intensive and costly. As a consequence of the needs for an effective and practical dissolution mechanism for polysulfide resin, the gel of the present invention was developed and found to be effective. The gel adheres well and allows the chemical formulation to be in direct contact with the cured polysulfide resin present on vertical and overhead surfaces. Reacted polysulfide may be easily wiped away to complete the task or when thick layers of material must be removed, additional gel-form of the chemistry may be added to repeat the process. Where necessary, a rinse may be used instead of wiping with a rag or napkin. Rinses include alcohol or water which causes the reacted polysulfide and gel to emulsify and disperse, allowing small orifices and cracks to be rinsed and left clean. SUMMARY OF INVENTION It has now been discovered, according to the invention, that a composition comprising a blend of chemistries and a viscosity modifier (gelling agent), which will revert, i.e. breakdown, and dissolve fully crosslinked (cured) polysulfide resins present on non-horizontal or open areas can be prepared. Such polymers include various sulfide containing polymers consisting primarily of crosslinked poly-dithioethylenes, -tetrathioethylenes, -thiobiphenylenes, -thiodifluoromethylenes, and -thiophenylenes and other related compounds containing the [—C—S—C—]n linkage. When the crosslinked polysulfide is exposed to the composition of the invention, the polymer will begin to breakdown, allowing the residue to be easily wiped or rinsed away. Applications and use of compositions of the invention include the removal of polysulfide encapsulation in electronics, sealants in aircraft, coatings and sealants in fuel tanks, and other uses involving situations where the elimination of insoluble crosslinked (cured) polysulfide polymer is desired. Due to the unique gel-form nature of the invention, opportunities exist to use it where controlled removal of a polysulfide resin from an open area where common solvents having low viscosity would travel to unwanted locations. Examples of controlled polysulfide resin removal from difficult and open areas include vertical and overhead surfaces. The gel-form of the invention may be applied by many means including pallet knife, paint-type roller, pump, sealant-type gun, or simply wipes and rubber gloves. Once applied, the removal rates to effect a thorough elimination, i.e. dissolution of any given cured polysulfide, will vary depending upon the formulation of the polysulfide, i.e., fillers contained, and amount, i.e., thickness present. Heat and agitation may be used to improve the removal process. DETAILED DESCRIPTION OF THE INVENTION In accordance with the invention we have discovered a solvent system to remove cured polysulfide coatings that is effective and facilitates the usage and adherence on vertical and overhead surfaces without significant dripping and thereby provides the retention time for solvating of the coatings. The invention is achievable with a composition of (a) dimethylacetamide (DMAC) between 70-90%, (b) tripropyleneglycol monomethylether (TPM) between 2-10%, (c) 1,8-diazabicyclo(5.4.0)undec-7-ene (DBU) between 2-10%, (d) hydroxypropylcellulose between 1-5%, and (e) a nonionic alkoxylated linear alcohol (surfactant) of between 0.5-1.0%. We have found that the composition of this kind comprise a gel-like consistency that adheres well, without significant runoff, to vertical and overhead surfaces, and is effective in dissolving cured polysulfide resins thereby facilitating the easy removal of the coating with little or no additional treatment such as abrading or mechanical action. This invention describes a novel chemistry in the form of a gel, which allows the removal of polysulfide-based resins from a variety of surfaces. The chemistry contains a polar solvent system and a strong amine having a pKa value of near 12. When a cellulosic-based polymerization additive is used in the preparation of the mixture, the result is a gel form of the final product that is stable over long periods of time. This gel-form solvent system allows its application to vertical and overhead surfaces with a high selectivity. Once the solvent system is brought into contact with the polysulfide resin, the amine component extracts the sulfide and breaks down the resin where it may be easily wiped away from the surface, leaving the underlying substrate unharmed. In situations where wiping with a rag or napkin is not possible or impractical, rinsing with alcohol or water may be performed. The rinse mixes with the gel and reacted polysulfide to emulsify and disperse it from the substrate, leaving small cracks and hard to reach crevices free of residue. The invention has ability in dissolving cured polysulfide resinous coating and is particularly advantageous in the removal of vertical and overhead surfaces, which when using liquid compositions (i.e., non-gel form) have the tendency to drip. The invention has proved to be effective due to its ability to adhere to such surfaces without significant dripping and to fully dissolve the crosslinked cured polysulfide resin layer. An abrading or grinding action, which often results in damage to the surface, is not needed. The primary object of the present invention is to provide a gel or gelling capable chemistry that is particularly adapted for dissolving and removing cured polysulfide formulations from a variety of substrates. The gel-form of the invention is found to wet the surface while firmly adhering, particularly to vertical and overhead areas such that minimal or no dripping occurs. By minimizing the messy nature of using solvents in hard to reach areas where sensitive devices (e.g., wires, linkages, circuitry, etc.) may exist, the material may be more easily controlled. The gel-form of the cleaner will minimize exposure to the operator as well as minimize usage. The base formulation is designed for maximum performance on dissolving and removing cured polysulfide resins. The system must be free of water (e.g., anhydrous) in order for it to penetrate and swell the cured resin. The preferred solvent, dimethylacetamide (DMAC) is designed for effective action and solubility on the resin, while the amine, 1,8-diazabicyclo(5.4.0)undec-7-ene (DBU), is present to leach-out the sulfide chemistry and react to effect complete dissolution. A high molecular weight co-solvent, tripropyleneglycol monomethylether (TPM) is present to enhance gelling capacity and to effect dispersion of the sulfide reactants during removal. Suitable surfactants include non-ionic alkoxylated linear alcohols such as the tradename Plurafac SL92, available from BASF Corporation. The surfactant functions to reduce surface tension and aid in the rinsing process. The surfactant preferably has a high cloud point (i.e., >60° C.) to allow for heated processing and rinsing without miscibility issues. A non-ionic environment is required for inert conditions towards dissolved metals and maximum solubility in a wide range of media, both solvent and water. Low foaming capacity allows for product use in various automated equipment. Alternative surfactants include nonyl-phenols and nonyl-ethoxylates with a HLB (hydrophilic/lipophilic balance) ranging from 7-15. Less than about 2 weight percent of the non-ionic surfactant and preferable an amount of about 0.5 to about 1 weight percent is sufficient. General Procedure In preparing the stripping composition of the invention, a preferred order of addition is employed. As stated earlier, the invention includes a viscosity modifier (gelling agent) which has been shown to be concentration dependent in performance, prone to agglomerate without proper mixing, and also to be sensitive with certain organic materials, namely, amines or similar organic alkalis. Therefore, it is important to add the majority of constituents and begin mixing, saving the gelling agent and DBU amine for last. For proper dispersion and reaction of the gel, it is generally preferable to add the gelling agent to the mixture during the mixing process, allow a given period of time for the gelling agent to disperse or wet-out in the given chemistry, and then add the DBU amine ingredient last. Therefore, all of the solvents and the surfactant are measured in the desired proportion and introduced into a suitable mixing vessel and thoroughly mixed by stirring. The stirring mechanism is most preferred to be a rotary device with spinning paddle or impeller. The design of the impeller should be consistent with the general equipment that is commonly used for high speed dispersion, however, this mixing process does not require mixing speeds to >1500 rpm. Examples of impeller designs include diameters that are approximately ⅓ of that diameter of the mixing vessel, normally a round-type or cylindrical tank. Further, when mixing, the impeller should be approximately ⅓ of the distance from the tank vessel bottom as compared with that same distance to the liquid level. Information on these mixing practices may be sought in a variety of texts which discuss fundamentals of high speed dispersion. Once the mixing vessel equipment is set-up and the solvents and surfactant are mixing, the gelling agent may be added. The gelling agent (hydroxypropylcellulose) is normally available in plastic lined paper bags as a fine powder. It is added slowly by sprinkling the desired amount into the chemistry while the mixing operation is underway. The gelling agent is allowed to mix into the chemistry for at least 15 min. and up to about to 30 min. During this period, the mixture will become noticeably thicker, revealing a higher product viscosity. Although a higher viscosity is noted, the product still flows and pours. To allow for continued proper dispersion and mixing, the mixing speed may need to be adjusted upwards. After the initial period of 15-30 min. is completed for wetting of the gelling agent, the DBU amine may be added. The amine is added to the contents in the same fashion as that for the gelling agent, namely, while mixing is underway. When the amine DBU is added, a significant increase in viscosity is anticipated. The operator should be prepared for this change and shall increase the impeller speed as necessary to effect proper mixing of the contents. As the gelling reaction continues, the product will increase in viscosity to the point where it becomes a gel. Mixing may be continued for another 15-30 min., or until the operator is comfortable with the homogeneity of the final product. At this point, the mixing process may be shut down and the viscosity measurement begins. Viscosity measurement is conducted with a rotational, spindle-type equipment that measures the torque required to rotate an immersed tool of defined shape inside the given medium. An example for such equipment is the Digital Viscometer, Model DV-I+ with a variety of spindle shapes and sizes, as manufactured by Brookfield Engineering Laboratories, Inc. The instrument is able to measure fluid viscosities at >50,000 centipoise (cps). Using this type of equipment and spindles #4 and #6, measurements between 11,000-130,000 cps were recorded. Measurements should be taken during the early stages of mixing the invention and also be checked after a period of 3 days have elapsed. By comparing these values, a minimal allowable increase in viscosity may be experienced. However, a decrease, suggesting a material deterioration, is undesirable. Based upon testing formulations of the invention, the target viscosity values should be 25,000±10,000 cps at preparation time (i.e., within 3 hrs. of mixing), and 50,000±20,000 cps as measured after 3 days. A further description of this target range is given in Table 1. TABLE 1 Viscosity target for the invention using 1-5% w/w of gelling agent. Medium Viscosity, Min Viscosity, Target Viscosity, Max 1-5% gelling 15,000 25,000 35,000 Agent, <3 hrs. 1-5% gelling 30,000 50,000 70,000 Agent, 72 hrs. In working with formulations of the invention, if viscosities of the final product falls within the values noted at 72 hrs. (i.e., 30,000-70,000 cps), the product is useful for maintaining its consistency for non-horizontal surfaces and is able to wet the surface to a minimum level necessary to carry-out the dissolution process. Although the invention has been described in terms of particular embodiments, blends of one or more of the various additives described herein can be used, and substitutes therefor, as will be know to those skilled in the art. Thus, the invention is not meant to be limited to the details described herein, but only by the scope of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Polysulfide-based resins are used widely in the protection and sealing of components and hardware in many industries that include aviation. In fact, polysulfide-based resins are the primary products of choice for sealing fuel tank compartments. Within aviation, fuel tank sealants are highly regulated by the federal government to provide specific performance qualities. These formulations have been held constant over many decades and are used in many aircraft from small recreational to commercial airlines. The application and maintenance of these materials are also deemed to be regulated and expected to be held constant over many years. When it becomes necessary to perform repair and maintenance on the polysulfide resin, it is most common to start with complete removal of the material from the area in question. Removal of the resin typically includes scraping and mechanical abrasion, resulting in significant damage to the underlying substrate. When substrate damage occurs, as is commonly the case, the surfaces must be reconditioned, requiring the use of several steps and significantly increasing the resources and cost of the original task. Attempts to use solvents render it impossible to control the cleaner to select areas or to vertical and overhead structures. When this fails, the operator typically defaults to the option of using mechanical action. Therefore, current practice in the maintenance and repair of polysulfide resin is labor-intensive and costly. As a consequence of the needs for an effective and practical dissolution mechanism for polysulfide resin, the gel of the present invention was developed and found to be effective. The gel adheres well and allows the chemical formulation to be in direct contact with the cured polysulfide resin present on vertical and overhead surfaces. Reacted polysulfide may be easily wiped away to complete the task or when thick layers of material must be removed, additional gel-form of the chemistry may be added to repeat the process. Where necessary, a rinse may be used instead of wiping with a rag or napkin. Rinses include alcohol or water which causes the reacted polysulfide and gel to emulsify and disperse, allowing small orifices and cracks to be rinsed and left clean. | <SOH> SUMMARY OF INVENTION <EOH>It has now been discovered, according to the invention, that a composition comprising a blend of chemistries and a viscosity modifier (gelling agent), which will revert, i.e. breakdown, and dissolve fully crosslinked (cured) polysulfide resins present on non-horizontal or open areas can be prepared. Such polymers include various sulfide containing polymers consisting primarily of crosslinked poly-dithioethylenes, -tetrathioethylenes, -thiobiphenylenes, -thiodifluoromethylenes, and -thiophenylenes and other related compounds containing the [—C—S—C—] n linkage. When the crosslinked polysulfide is exposed to the composition of the invention, the polymer will begin to breakdown, allowing the residue to be easily wiped or rinsed away. Applications and use of compositions of the invention include the removal of polysulfide encapsulation in electronics, sealants in aircraft, coatings and sealants in fuel tanks, and other uses involving situations where the elimination of insoluble crosslinked (cured) polysulfide polymer is desired. Due to the unique gel-form nature of the invention, opportunities exist to use it where controlled removal of a polysulfide resin from an open area where common solvents having low viscosity would travel to unwanted locations. Examples of controlled polysulfide resin removal from difficult and open areas include vertical and overhead surfaces. The gel-form of the invention may be applied by many means including pallet knife, paint-type roller, pump, sealant-type gun, or simply wipes and rubber gloves. Once applied, the removal rates to effect a thorough elimination, i.e. dissolution of any given cured polysulfide, will vary depending upon the formulation of the polysulfide, i.e., fillers contained, and amount, i.e., thickness present. Heat and agitation may be used to improve the removal process. detailed-description description="Detailed Description" end="lead"? | 20040301 | 20060228 | 20050901 | 75927.0 | 0 | DELCOTTO, GREGORY R | DISSOLVING GEL FOR CURED POLYSULFIDE RESINS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,790,748 | ACCEPTED | Integrated exercise detection device employing satellite positioning signal and exercise signal | An integrated exercise detection device includes a satellite positioning module that receives satellite signals associated with a user. The satellite positioning module includes a microprocessor that processes the received satellite signals to generate first data including current position, displacement, velocity and altitude of the user. The integrated exercise detection device further includes an exercise detection module that detects exercise signals of the user and generates second data in response thereto. The second data are transmitted to the microprocessor via for example electrical cables and/or wireless transmission comprised of wireless transmitter coupled to the exercise detection module and wireless receiver coupled to the microprocessor. A display is electrically coupled to the second microprocessor to selectively display the first and second data. | 1. An integrated exercise detection device comprising: a satellite positioning module adapted to receive satellite signals, comprising a first microprocessor processing the satellite signals to generate first data comprising at least a current position, a first displacement, a first velocity and an altitude of a user and a communication interface; a second microprocessor receiving the first data transmitted through the communication interface from the first microprocessor; an exercise detection module adapted to detect at least one exercise signal of the user and generating second data in response thereto, the second data being transmitted to the second microprocessor, the second microprocessor processing the second data to generate at least a second velocity and a second displacement therefrom, the second microprocessor comparing the first and second displacements and the first and second velocities and correcting the second displacement and the second velocity if different from the respective first displacement and first velocity; and a display electrically coupled to the second microprocessor to selectively display the first and second data. 2. The integrated exercise detection device as claimed in claim 1, wherein the exercise detection module comprises a step counter. 3. The integrated exercise detection device as claimed in claim 1, wherein the exercise detection module comprises a velocity/acceleration sensor. 4. The integrated exercise detection device as claimed in claim 1, wherein the second data generated by the exercise detection module is transmitted to the second microprocessor through an electrical wire. 5. The integrated exercise detection device as claimed in claim 1, wherein the second data generated by the exercise detection module is transmitted by a wireless transmitter circuit connected to the exercise detection module and received by a wireless receiving circuit connected to the second microprocessor. 6. An integrated exercise detection device comprising: a satellite positioning module adapted to receive satellite signals, comprising a microprocessor processing the satellite signals to generate first data comprising at least a current position, a first displacement, a first velocity and an altitude of a user and a communication interface; an exercise detection module adapted to detect at least one exercise signal of the user and generating second data in response thereto, the second data being transmitted to the microprocessor, the microprocessor processing the second data to generate at least a second velocity and a second displacement therefrom, the microprocessor comparing the first and second displacements and the first and second velocities and correcting the second displacement and the second velocity if different from the respective first displacement and first velocity; and a display electrically coupled to the microprocessor to selectively display the first and second data. 7. The integrated exercise detection device as claimed in claim 6, wherein the exercise detection module comprises a step counter. 8. The integrated exercise detection device as claimed in claim 6, wherein the exercise detection module comprises a velocity/acceleration sensor. 9. The integrated exercise detection device as claimed in claim 6, wherein the second data generated by the exercise detection module is transmitted to the microprocessor through an electrical wire. 10. The integrated exercise detection device as claimed in claim 6, wherein the second data generated by the exercise detection module is transmitted by a wireless transmitter circuit connected to the exercise detection module and received by a wireless receiving circuit connected to the microprocessor. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a device for detection conditions of outdoor exercises, and in particular to a device for detecting exercise conditions of bicycle riding by employing both satellite positioning signals received from satellites of a Global Positioning System (GPS) and exercise signals provided by sensors mounted on the bicycle/rider. 2. The Related Art Exercises have been an important daily activity for modern urbanites. Exercise devices for both indoor and outdoor exercises are commonly available in the market. To ensure the result of exercise, some exercise devices are equipped with an exercise detection device that detects the exercise conditions and shows the detection result to the users. For example, a senor can be mounted on the pedal crank of a bicycle to detect and record the revolution and rotation speed of bicycle wheels. Independent detection devices are also available for detection of exercise conditions, such as a step counter that is attached to the body of a user to count the number of steps/strides that the user takes. Most of the exercise detection devices are of single function designs. In other words, they detect only one particular kind of signal, such as signal of physical condition of a user or signal of motion of an exercising device, for example speed of a moving bicycle. Devices that receive two kinds of signal for detection of exercise conditions, to the best the inventor knows, are not available in the market. Global positioning system (GPS) is well known for detecting the position of an object with the aids of radio frequency transmission from satellites. Satellite positioning signals obtained from GPS allows a user to know the position of an object at any particular time points and, based on the data of positions, the speed and moving distance can also be obtained. The GPS also provides data of altitude of the object in a global sense. Due to the fact that transmission of GPS signals between the satellite and a user may be interfered with by large objects that shield between the satellite and the user, GPS signals cannot actually reflect the exercise condition timely. In addition, taking bicycle riding as an example, the GPS provides only the information of displacement, speed and altitude of the bicycle and the rider. However, there is no way that a user of the GPS system can know information regarding pedaling of the rider, such as the pedaling speed (the rotational speed of the crank). Thus, the present invention is aimed to provide an exercise detection device that employs signals from different sources for providing more precise condition of exercise to a user. SUMMARY OF THE INVENTION An object of the present invention is to provide an integrated exercise detection device that receives both satellite positioning signals from GPS satellites and exercise signals obtained from a person taking exercise with/without an exercise device whereby actual exercise conditions can be obtained by calibrating the signals with each other. Another object of the present invention is to provide an exercise detection device comprising a satellite signal receiving/processing device that provides dynamic positional data and a device, such as velocity sensor, for detecting exercise conditions of a user, such as velocity, whereby both position and velocity, as well as other exercise conditions, can be provided timely. A further object of the present invention is to provide an exercise detection device that is combined with a satellite signal receiving/processing device whereby geometrical data, such as position, altitude as well as displacement and velocity that can be inferred from the geometrical data, and exercising data, such as number of steps taken and speed, of an exerciser can be provided to a user simultaneously. To achieve the above objects, in accordance with the present invention, there is provided an integrated exercise detection device comprising a satellite positioning module and an exercise detection module. The satellite positioning module receives satellite signals associated with a user, such as a person riding a bicycle. The satellite positioning module comprises a microprocessor that processes the received satellite signals to generate first data including current position, displacement, velocity and altitude of the user and a communication interface. The integrated exercise detection device further comprises an exercise detection module that detects exercise signals of the user and generates second data in response thereto. The second data are transmitted to the microprocessor via for example electrical cables and/or wireless transmission comprised of wireless transmitter coupled to the exercise detection module and wireless receiver coupled to the microprocessor. A display is electrically coupled to the second microprocessor to selectively display the first and second data. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be apparent to those skilled in the art by reading the following description of preferred embodiments thereof, with reference to the attached drawings, in which: FIG. 1 is a perspective view of an integrated exercise detection device constructed in accordance with the present invention; FIG. 2 is a block diagram of a circuit of the integrated exercise detection device of a first embodiment of the present invention adapted to be used in FIG. 1; FIG. 3 is a block diagram of a circuit of the integrated exercise detection device of a second embodiment of the present invention adapted to be used in FIG. 1; FIG. 4 is a plot of stride length vs. stride rate; FIG. 5 is a schematic view showing a person wearing the integrated exercise detection device of the present invention; FIG. 6 is a block diagram of a circuit of the integrated exercise detection device of a third embodiment of the present invention adapted to be used in FIG. 5; FIG. 7 is a block diagram of a circuit of the integrated exercise detection device of a fourth embodiment of the present invention adapted to be used in FIG. 5; and FIG. 8 shows an application of the integrated exercise detection device on outdoor bicycle riding. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS With reference to the drawings and in particular to FIG. 1, an integrated exercise detection device constructed in accordance with the present invention, generally designated with reference numeral 100, is made in the form that can be worn on the body of a user, comprising a display device 102 connected to and retained by strips 101 on opposite sides thereof. The display device 102 may display information or data regarding time, step counts, velocity or speed, current position, displacement and altitude. Also referring to FIG. 2, a circuit of the integrated exercise detection device of a first embodiment of the present invention adapted to be used in FIG. 1 comprises a satellite positioning module 2 and an exercise detection module 3, both of which are electrically connected to a display unit 5 that constitutes in part of the display device 102. The satellite positioning module 2 comprises an antenna 20, an RF (radio frequency) receiving circuit 21 that is connected to the antenna 20 for receiving satellite positioning signal through the antenna 20, a multiple channels logic circuit 22 connected to the RF receiving circuit 21, a first microprocessor 23 connected to the RF receiving circuit 21 via the multiple channels logic circuit 22, an oscillator 24 providing oscillation signal to the first microprocessor 23 through a frequency divider 25, a real time control (RTC) 26 connected to the first microprocessor 23 and memory means, including read only memory (ROM) 27 and random access memory (RAM) 28, connected to the first microprocessor 23. The first microprocessor 23 is electrically connected, via a communication interface 29 and communication lines Tx and Rx, to a second microprocessor 4. Satellite positioning signals are received by the RF receiving circuit 21 through the antenna 20 and then applied to the first microprocessor 23 through the multiple channels logic circuit 22. The satellite positioning signals are processed by the first microprocessor 23, which performs calculation based on pre-loaded algorithm to determine the current position, displacement, velocity and altitude of an exerciser. The data of current position, displacement, velocity and altitude are then transmitted by the communication interface 29 through the communication lines Tx and Rx to the second microprocessor 4 that controls the display unit 5 to display the data on the display device 102. A user or the exerciser can inspect the exercise conditions by observing the display device 102. The exercise detection module 3 comprising a vibration/acceleration sensor 31 for detecting exercise signals, which may include for example a step counter or a velocity detector, issuing an exercise signal obtained from the exerciser. The exercise signal is amplified by an amplifier 32 and filtered by a filter 33. The amplified and filtered signal is then waveform-shaped by a shaping circuit 34 before the signal is transmitted, via an electrical wire 34a, to the second microprocessor 4 for display by the display unit 5. Referring to FIG. 3, a circuit of the integrated exercise detection device of a second embodiment of the present invention adapted to be used in FIG. 1 comprises a microprocessor 6 to replace with the first microprocessor 23 and the second microprocessor 4 in FIG. 2. Similarly, satellite positioning signals are received by the RF receiving circuit 21 through the antenna 20 and then applied to the microprocessor 6 through the multiple channels logic circuit 22. The satellite positioning signals are processed by the microprocessor 6, which performs calculation based on pre-loaded algorithm to determine the current position, displacement, velocity and altitude of an exerciser. The microprocessor 6 is capable of controlling the display unit 5 to display the data on the display device 102. A user or the exerciser can inspect the exercise conditions by observing the display device 102. The exercise detection module 3 comprising a vibration/acceleration sensor 31 for detecting exercise signals, which may include for example a step counter or a velocity detector, issuing an exercise signal obtained from the exerciser. The exercise signal is amplified by an amplifier 32 and filtered by a filter 33. The amplified and filtered signal is then waveform-shaped by a shaping circuit 34 before the signal is transmitted, via an electrical wire 34a, to the microprocessor 6 for display by the display unit 5. The exercise detection module 3 detects the exercise signals that are generated by the movement and action of the exerciser during taking an exercise, such as bicycle riding and calculating data regarding speed and distance on the basis of the detected exercise signals. FIG. 4 is a plot of stride length vs. stride rate, which shows the relationship between the stride length and stride rate. The X-axis represents the stride rate of the user, and the Y-axis represents the stride length of the user. It is noted that a slower stride rate R1 responses to a shorter stride length L1, while a faster stride rate R2 responses to a longer stride length L2, as indicated in the plot. So, a regular curve L is obtained. According to the plot, the moving speed and distance of the user during exercising may be calculated. In other words, the stride length changes with the change of stride rate and such change may cause error in detection and/or determination of speed and distance by the exercise detection module 3. In an aspect of the present invention, such an error can be corrected by comparison with data obtained from the satellite positioning signals that are provided by the satellite positioning receiver module 2. The exercise detection module 3 can be of any known device, such as a speed sensor that is conventionally known, including one-dimensional (X axis), two-dimensional (X and Y axes) or three-dimensional (X, Y and Z axes) acceleration sensor. With reference to FIG. 5, the integrated exercise detection device of the present invention can be worn on any suitable location on the body of the user. For example, the integrated exercise detection device includes a satellite positioning module 100a which is made in the form of a wrist watch adapted to be worn on the wrist of the use, and an exercise detection module 100b adapted to be simply worn on the waist of the user. Referring to FIG. 6, which shows a third embodiment of the integrated exercise detection device in accordance with the present invention, which is adapted to be used in FIG. 5. This embodiment of the integrated exercise detection device is substantially identical to the first embodiment with reference to FIG. 2. Thus, the same components will carry the same reference numeral references and no further detail will be given herein. Instead of connection of the exercise detection module 3 to the second microprocessor 4 by an electrical cable as shown in FIG. 2, the exercise detection module 3 of the third embodiment is coupled to the second microprocessor 4 in a wireless manner. For example, the waveform-shaped exercise signals are processed by a transmitter circuit 35 for transmission in electromagnetic wave through an antenna 36. The second microprocessor 4 comprises a receiving circuit 41 that receives the exercise signals in the form electromagnetic wave through an antenna 42. The received signals are the applied to the second microprocessor 4 for display by the display unit 5. Referring to FIG. 7, a circuit of the integrated exercise detection device of a fourth embodiment of the present invention adapted used in FIG. 5 comprises a microprocessor 6 to replace with the first microprocessor 23 and the second microprocessor 4 in FIG. 6. Similarly, satellite positioning signals are received by the RF receiving circuit 21 through the antenna 20 and then applied to the microprocessor 6 through the multiple channels logic circuit 22. The satellite positioning signals are processed by the microprocessor 6, which performs calculation based on pre-loaded algorithm to determine the current position, displacement, velocity and altitude of an exerciser. The microprocessor 6 is capable of controlling the display unit 5 to display the data on the display device 102. A user or the exerciser can inspect the exercise conditions by observing the display device 102. The exercise detection module 3 comprising a vibration/acceleration sensor 31 for detecting exercise signals, which may include for example a step counter or a velocity detector, issuing an exercise signal obtained from the exerciser. The exercise signal is amplified by an amplifier 32 and filtered by a filter 33. The amplified and filtered signal is then waveform-shaped by a shaping circuit 34. The waveform-shaped exercise signals are processed by a transmitter circuit 35 for transmission in electromagnetic wave through an antenna 36. The microprocessor 6 comprises a receiving circuit 41 that receives the exercise signals in the form electromagnetic wave through an antenna 42. The received signals are the applied to the microprocessor 6 for display by the display unit 5. The wireless connection between the exercise detection module 3 and the satellite positioning receiver module 2 allows the exercise detection module 3 to be mounted at a position remote from the satellite positioning receiver module 2. An example is shown in FIG. 8, wherein the satellite positioning receiver module 100c comprises a satellite positioning receiver module mounted to for example the handbar of a bicycle 7, while the exercise detection module comprises a velocity sensor 100d mounted to the pedal 71 of the bicycle 7 for detection of the revolution of the pedal 71. Pedaling signal detected by the exercise detection module is applied to the second microprocessor in for example the wireless manner as shown in FIG. 6. The second microprocessor 4 perform calculation to obtain the revolution of the bicycle, which can then be converted into the speed of the bicycle. The speed of the bicycle may also be obtained from the satellite positioning signals and both speeds can be used to provide exact speed of the bicycle. For example, when the satellite signals are blocked by for example a tunnel, the speed obtained from the velocity sensor may be used alone to indicate the moving speed of the bicycle. Although the present invention has been described with reference to the preferred embodiments thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates generally to a device for detection conditions of outdoor exercises, and in particular to a device for detecting exercise conditions of bicycle riding by employing both satellite positioning signals received from satellites of a Global Positioning System (GPS) and exercise signals provided by sensors mounted on the bicycle/rider. 2. The Related Art Exercises have been an important daily activity for modern urbanites. Exercise devices for both indoor and outdoor exercises are commonly available in the market. To ensure the result of exercise, some exercise devices are equipped with an exercise detection device that detects the exercise conditions and shows the detection result to the users. For example, a senor can be mounted on the pedal crank of a bicycle to detect and record the revolution and rotation speed of bicycle wheels. Independent detection devices are also available for detection of exercise conditions, such as a step counter that is attached to the body of a user to count the number of steps/strides that the user takes. Most of the exercise detection devices are of single function designs. In other words, they detect only one particular kind of signal, such as signal of physical condition of a user or signal of motion of an exercising device, for example speed of a moving bicycle. Devices that receive two kinds of signal for detection of exercise conditions, to the best the inventor knows, are not available in the market. Global positioning system (GPS) is well known for detecting the position of an object with the aids of radio frequency transmission from satellites. Satellite positioning signals obtained from GPS allows a user to know the position of an object at any particular time points and, based on the data of positions, the speed and moving distance can also be obtained. The GPS also provides data of altitude of the object in a global sense. Due to the fact that transmission of GPS signals between the satellite and a user may be interfered with by large objects that shield between the satellite and the user, GPS signals cannot actually reflect the exercise condition timely. In addition, taking bicycle riding as an example, the GPS provides only the information of displacement, speed and altitude of the bicycle and the rider. However, there is no way that a user of the GPS system can know information regarding pedaling of the rider, such as the pedaling speed (the rotational speed of the crank). Thus, the present invention is aimed to provide an exercise detection device that employs signals from different sources for providing more precise condition of exercise to a user. | <SOH> SUMMARY OF THE INVENTION <EOH>An object of the present invention is to provide an integrated exercise detection device that receives both satellite positioning signals from GPS satellites and exercise signals obtained from a person taking exercise with/without an exercise device whereby actual exercise conditions can be obtained by calibrating the signals with each other. Another object of the present invention is to provide an exercise detection device comprising a satellite signal receiving/processing device that provides dynamic positional data and a device, such as velocity sensor, for detecting exercise conditions of a user, such as velocity, whereby both position and velocity, as well as other exercise conditions, can be provided timely. A further object of the present invention is to provide an exercise detection device that is combined with a satellite signal receiving/processing device whereby geometrical data, such as position, altitude as well as displacement and velocity that can be inferred from the geometrical data, and exercising data, such as number of steps taken and speed, of an exerciser can be provided to a user simultaneously. To achieve the above objects, in accordance with the present invention, there is provided an integrated exercise detection device comprising a satellite positioning module and an exercise detection module. The satellite positioning module receives satellite signals associated with a user, such as a person riding a bicycle. The satellite positioning module comprises a microprocessor that processes the received satellite signals to generate first data including current position, displacement, velocity and altitude of the user and a communication interface. The integrated exercise detection device further comprises an exercise detection module that detects exercise signals of the user and generates second data in response thereto. The second data are transmitted to the microprocessor via for example electrical cables and/or wireless transmission comprised of wireless transmitter coupled to the exercise detection module and wireless receiver coupled to the microprocessor. A display is electrically coupled to the second microprocessor to selectively display the first and second data. | 20040303 | 20051220 | 20050908 | 77578.0 | 13 | RICHMAN, GLENN E | INTEGRATED EXERCISE DETECTION DEVICE EMPLOYING SATELLITE POSITIONING SIGNAL AND EXERCISE SIGNAL | SMALL | 0 | ACCEPTED | 2,004 |
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10,790,812 | ACCEPTED | Grounding apparatus of print circuit board in a liquid crystal display | A liquid crystal display (LCD) has a plastic frame for supporting a liquid crystal display panel and a metal cover for boxing the plastic frame. A print circuit board (PCB) is fixed on a lower surface of the plastic frame and connects to the liquid crystal display panel by using a flexible flat cable that extends along a sidewall of the plastic frame. A conductive film is taped both on a grounding pin of the PCB and on a sidewall of the metal cover for discharging segregated charges on the PCB to the environment. | 1. A liquid crystal display comprising: a liquid crystal display panel; a plastic frame, supporting said liquid crystal display panel; a metal cover, boxing said plastic frame therein and forming an interior space to accommodate said liquid crystal display panel; a print circuit board, fixed on a lower surface of said plastic frame and connecting to said liquid crystal display panel by a flexible flat cable extending along a sidewall of said plastic frame; and a conductive film, formed on a grounding pin of said print circuit board and another sidewall of said metal cover for transmitting segregated charges on said print circuit board through said metal cover to environment. 2. The liquid crystal display of claim 1, further comprising a passivation film taped on a lower surface of said print circuit board as an electric shielding. 3. The liquid crystal display of claim 2, wherein said passivation layer extends further to cover the flexible flat cable. 4. The liquid crystal display of claim 1, wherein said conductive film is taped on the grounding pin and said metal cover by gluing. 5. The liquid crystal display of claim 1, wherein said conductive film is a conductive tape with both surfaces gluey, in which one surface of said conductive tape is taped on the grounding pin of said print circuit board and the sidewall of said metal cover and the other surface is used to glue a passivation film on a lower surface of said print circuit board to form an electric shielding upon devices on said print circuit board. 6. The liquid crystal display of claim 1, wherein said print circuit board connects to said liquid crystal display panel through the flexible flat cable and attends with connecting devices such as tape automated bounding (TAB), chip on glass (COG), or chip on film (COF). 7. The liquid crystal display of claim 1, wherein said two grounding pins are formed at opposite edges of said print circuit board without connecting flexible flat cables. 8. The liquid crystal display of claim 1, wherein the grounding pin is form on a lower surface of said print circuit board. 9. The liquid crystal display of claim 1, wherein the grounding pin extends from an edge of said print circuit board to the outside. 10. The liquid crystal display of claim 1, wherein said conductive film is taped around said print circuit board. 11. A print circuit board assembled in a liquid crystal display and utilized to control displaying signals, comprising: a plurality of flexible flat cables, extending from an edge of the print circuit board to a liquid crystal display panel; a grounding pin, formed on the print circuit board; a passivation film, covering an exposed surface of the print circuit board as an electric shielding; and a conductive film, taped on both said grounding pin and a metal cover of the liquid crystal display to transport segregated charges on the print circuit board to environment, and taped along the edges of the print circuit board to fix said passivation film. 12. The print circuit board of claim 11, wherein said grounding pin is formed on an edge of the print circuit board without connecting flexible flat cables. 13. The print circuit board of claim 11, wherein said grounding pin is formed on the exposed surface of the print circuit board and close to an edge of the print circuit board. 14. The print circuit board of claim 11, wherein said grounding pin is extended from an edge of the print circuit board to outside the print circuit board. 15. The print circuit board of claim 11, wherein said conductive film is a conductive tape with both surfaces gluey, in which one surface of said conductive tape is taped on said grounding pin and sidewalls of the metal cover and the other surface is used to glue said passivation film on a lower surface of the print circuit board to form an electric shielding upon devices on the print circuit board. 16. The print circuit board of claim 11, wherein the print circuit board connects to the liquid crystal display panel through said flexible flat cable. | BACKGROUND OF THE INVENTION (1) Field of the Invention This invention relates to an apparatus utilized for grounding a print circuit board of a liquid crystal display, and more particularly to an apparatus for forming an electric connection between the print circuit board and the metal box of the liquid crystal display. (2) Description of Related Art Along with enormous promotions of thin film transistor (TFT) fabrication technique, liquid crystal displays (LCD) are broadly adopted to personal digital assistants (PDA), notebooks (NB), digital cameras (DC), digital videos (DV), mobile phones, etc. Typically, a cold cathode fluorescent lamp (CCFL) is inserted into the LCD as a backlight source. A liquid crystal (LC) driving circuit is used to decode input signals for forming displaying data and scanning sequence data to further control the image of the LCD. Ordinarily, in order to increase a display size of the LCD and to simplify the LCD fabrication sequence, the LC driving circuit is usually formed on a print circuit board (PCB) instead of formed traditionally on a glass substrate, accompanied by devices such as tape automated bounding (TAB), chip on glass (COG), chip on film (COF), etc. The PCB having the LC driving circuit is thus able to issue controlling signals to the LCD panel through a flexible flat cable (FFC). Because environmental noises may disturb the LC driving circuit by messing the formation of the controlling signals, a proper electric shielding is usually introduced to the PCB so as to remove the charges left on the PCB during LC driving circuit operation. Definitely, upon such an arrangement, a specific grounding apparatus should be added on the PCB. In FIG. 1, a typical LCD 10 comprises a metal cover 100, a plastic frame 200, an LCD panel 300, and a PCB 400. The LCD panel 300 and the PCB 400 are fixed on the opposite surfaces of the plastic frame 200 with an inter-connected FFC 410. The metal cover 100 boxes the plastic frame 200 therein to form an interior space for accommodating the LCD panel 300. In order to prevent a particular electric current in the LC driving circuit from being disturbed by segregated charges on the PCB 400, as shown in FIG. 2, the PCB 400 has two grounding pins 430 formed on both edges 400b adjacent to sidewalls of the metal cover 100b for removing the segregated charges. Also referring to FIG. 1, each grounding pin 430 is fastened to the plastic frame 200 by using a PCB screw 435 and also electrically connected to the metal cover 100 by using an elastic conductive plate 440, which is fastened to the sidewall of the metal cover 100b by sending a grounding screw (not shown in this figure) into a hole 460 on the metal cover 100. As mentioned, the grounding pin 430, the elastic conductive plate 440, the PCB screw 435, and the grounding screw are all used to achieve the purpose for grounding the PCB 400 in the art. Yet, with all these parts for grounding the PCB 400, a significant increase of time and labor on assembling an LCD is inevitable. In addition, while in screwing the PCB 400, the power to drive each screw should be carefully controlled so that screws as the fasten device won't damage the PCB 400 or the metal cover 100. Ordinarily, in order to control the screw driving power within a safety range, a power testing apparatus is also used in the assembling process to assure the process reliability. Therefore, an improvement of a grounding apparatus targeting to minimize the number of elements and the assembling time without sacrificing the grounding effect is definitely welcome to the skilled persons in the art. SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to simplify a grounding apparatus used for grounding a PCB of an LCD, which can also save the time needed to assemble the grounding apparatus. An LCD of the present invention comprises an LCD panel, a plastic frame, a metal cover, a PCB, and a conductive film. The plastic frame is used to settle the LCD panel. The metal cover boxes the plastic frame and the LCD panel therein. The PCB is fixed on a lower surface of the plastic frame and connects to the LCD panel by using an FFC extending along a sidewall of the plastic frame. The conductive film taped on a grounding pin of the PCB and a sidewall of the metal cover is used to discharge the segregated charges on the PCB, through the metal cover, to the environment. Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be specified with reference to its preferred embodiment illustrated in the drawings, in which FIG. 1 depicts a schematic view of a PCB in a traditional LCD, in which the PCB is grounded by using a metal cover as a grounding inter-media; FIG. 2 depicts a bottom view of the LCD of FIG. 1; FIG. 3A depicts a schematic view of a first embodiment of the LCD in accordance with the present invention; FIG. 3B depicts a bottom view of the LCD of FIG. 3A; FIG. 4A depicts a bottom view of a second embodiment of the LCD in accordance with the present invention; FIG. 4B shows the LCD of FIG. 4A further having a passivation film taped thereon; FIG. 4C depicts a schematic enlarged view of a lower surface of the PCB of FIG. 4A having a passivation film taped thereon by using a conductive tape with both surfaces gluey; FIG. 4D depicts a schematic view of another embodiment of the LCD in accordance with the present invention, in which the a conductive tape with both surfaces gluey is taped to a lower surface of the PCB; and FIG. 5 depicts a schematic view of a third embodiment of the LCD in accordance with the present invention. DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention disclosed herein is directed to a grounding apparatus of a PCB in an LCD. In the following description, numerous details are set forth in order to provide a thorough understanding of the present invention. It will be appreciated by one skilled in the art that variations of these specific details are possible while still achieving the results of the present invention. In other instance, well-known components are not described in detail in order not to unnecessarily obscure the present invention. In a first embodiment according to the present invention as shown in FIG. 3A, an LCD 10 comprises an LCD panel 300, a plastic frame 200, a metal cover 100, and a PCB 500. The LCD panel 300 is placed on the plastic frame 200. The metal cover 100 for boxing the plastic frame 200 forms an interior space 100b to accommodate both the LCD panel 300 and the plastic frame 200. The PCB 500 is fixed on a lower surface of the plastic frame 200 and connects to the LCD panel 300 by using a flexible flat cable 510 of a proper connecting device (not shown in this figure) to input displaying controlling signals, in which the connecting device can be a tape automated bounding (TAB), a chip on glass (COG), a chip on film (COF), or the like. Also referring to FIG. 3B, a bottom view of the LCD 10 of FIG. 3A is shown, in which a grounding pin 530 is extended from a blank edge of the PCB 500b (i.e., the side without connecting flexible flat cables 510). A conductive film 520 is taped to the grounding pin 530 and a portion of the nearby metal frame 100b, such that an electrical transmission path can be established to transport segregated charges on the PCB 500 to the environment. Furthermore, the conductive film 520 can also be attached on the plastic frame 200 to fix the PCB 500. Particularly, a conductive glue, such as a silver glue, can be coated onto the conductive film 520 so as to have the conductive film 520 firmly hold the grounding pin 530, the adjacent plastic frame 200, and the sidewall of the metal cover 100b. However, in a further simplification of assembly steps that can waive the above-described glue-coating step, a conductive tape (not shown) can be directly used to paste itself on the grounding pin 530, the plastic frame 200, and the sidewall of the metal cover 100b. In the foregoing embodiment of FIG. 3B, only one grounding pin 530 is used. However, to achieve a better charge-removing efficiency, a second embodiment having two grounding pins 530 formed on the PCB 500 is shown in FIG. 4A. The two grounding pins 530 are extended from opposite blank edges of the PCB 500b without connecting flexible flat cables 510, and each of the conductive films 520 are taped respectively on the grounding pin 530, the adjacent plastic frame 200, and the nearby sidewall of the metal cover 100b. In addition, to shield the circuit devices on the PCB 500 from being disturbed by environmental electrical noises, a passivation film 540 as shown in FIG. 4B is formed on an exposed lower surface of the PCB 500. It should be noted that the passivation film 540 also covers both the conductive film 520 and the flexible flat cable 510 so as to achieve a perfect electric shielding effect. In order to attach the passivation film 540 on the PCB 500, as shown in FIG. 4B, a simple way is to coat glue onto a lower surface of the conductive film 520 and the edges of the PCB 500b before the passivation film 540 is pasted thereon. It is also noted that the glue used is not restricted to the conductive glue. As a further simplification, as shown in FIG. 4C, a conductive tape 560 with both surfaces gluey is used instead of the conductive film 520 of FIG. 4A. One surface of the conductive tape 560 is taped on the grounding pin 530, the plastic frame 200, and the sidewalls of the metal cover 100b, while the other surface is used to glue a passivation film 540 on a lower surface of the PCB 500 as an electric shielding. Furthermore, to ensure the passivation film 540 to be perfectly attached on the PCB 500 so as to achieve perfectly electric shielding event, as shown in FIG. 4D, the conductive tape 560 is taped around all four edges of the PCB 500 to form a larger attaching area and a better adhering effect upon the passivation film 540. In the third embodiment of FIG. 5, a grounding pin 580 is fabricated right on the surface of the PCB 500 instead of extended from an edge of the PCB 500b of FIG. 4A. By attaching the grounding pin 580 with the conductive film 590, an electrical transmission path can be formed on the conductive film 590 between the grounding pin 580 and the metal cover 100. Obviously, the design of grounding pin 580 of FIG. 5 is simpler than that of FIG. 4A without degrading the grounding efficiency. By contrast to the grounding apparatus of FIG. 2, which shows that the PCB 400 is grounded by having the elastic conductive plate 440 fastened on the metal cover 100 with a screw. The grounding apparatus in the present invention has the following advantages: 1. The devices for grounding PCB 400 in the prior art, such as PCB screw 435, the elastic conductive plate 440, etc., are not required anymore in the grounding apparatus in accordance with the present invention. Therefore, the cost to assemble the LCD and the assembling time can be reduced. 2. As shown in FIG. 4A, a conductive film 520 is used instead of the grounding apparatus of FIG. 2, and the conductive film 520 is fixed by taping to form the electric transmission path for grounding the PCB 500. Therefore, the problem resulted from controlling the screw driving power of the grounding apparatus of FIG. 2 needs not to be concerned. 3. As shown in FIG. 4C, by using a conductive tape 560 with both surfaces gluey to form an electric transmission path for grounding the PCB 500, the passivation film 540 can be fixed on the PCB 500 in the same process. Therefore, the process to assemble the grounding apparatus is simplified. 4. In the third embodiment, the grounding pin 580 of FIG. 5 is fabricated right on the surface of the PCB 500 instead of the grounding pin 430 of FIG. 2 extended from an edge of the PCB 400b to reach the conductive elastic plate 440. It is clear that the fabrication process of the grounding pin 580 is simpler than that of the grounding pin 530. With the example and explanations above, the features and spirits of the invention will be hopefully well described. Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made when retaining the teaching of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>(1) Field of the Invention This invention relates to an apparatus utilized for grounding a print circuit board of a liquid crystal display, and more particularly to an apparatus for forming an electric connection between the print circuit board and the metal box of the liquid crystal display. (2) Description of Related Art Along with enormous promotions of thin film transistor (TFT) fabrication technique, liquid crystal displays (LCD) are broadly adopted to personal digital assistants (PDA), notebooks (NB), digital cameras (DC), digital videos (DV), mobile phones, etc. Typically, a cold cathode fluorescent lamp (CCFL) is inserted into the LCD as a backlight source. A liquid crystal (LC) driving circuit is used to decode input signals for forming displaying data and scanning sequence data to further control the image of the LCD. Ordinarily, in order to increase a display size of the LCD and to simplify the LCD fabrication sequence, the LC driving circuit is usually formed on a print circuit board (PCB) instead of formed traditionally on a glass substrate, accompanied by devices such as tape automated bounding (TAB), chip on glass (COG), chip on film (COF), etc. The PCB having the LC driving circuit is thus able to issue controlling signals to the LCD panel through a flexible flat cable (FFC). Because environmental noises may disturb the LC driving circuit by messing the formation of the controlling signals, a proper electric shielding is usually introduced to the PCB so as to remove the charges left on the PCB during LC driving circuit operation. Definitely, upon such an arrangement, a specific grounding apparatus should be added on the PCB. In FIG. 1 , a typical LCD 10 comprises a metal cover 100 , a plastic frame 200 , an LCD panel 300 , and a PCB 400 . The LCD panel 300 and the PCB 400 are fixed on the opposite surfaces of the plastic frame 200 with an inter-connected FFC 410 . The metal cover 100 boxes the plastic frame 200 therein to form an interior space for accommodating the LCD panel 300 . In order to prevent a particular electric current in the LC driving circuit from being disturbed by segregated charges on the PCB 400 , as shown in FIG. 2 , the PCB 400 has two grounding pins 430 formed on both edges 400 b adjacent to sidewalls of the metal cover 100 b for removing the segregated charges. Also referring to FIG. 1 , each grounding pin 430 is fastened to the plastic frame 200 by using a PCB screw 435 and also electrically connected to the metal cover 100 by using an elastic conductive plate 440 , which is fastened to the sidewall of the metal cover 100 b by sending a grounding screw (not shown in this figure) into a hole 460 on the metal cover 100 . As mentioned, the grounding pin 430 , the elastic conductive plate 440 , the PCB screw 435 , and the grounding screw are all used to achieve the purpose for grounding the PCB 400 in the art. Yet, with all these parts for grounding the PCB 400 , a significant increase of time and labor on assembling an LCD is inevitable. In addition, while in screwing the PCB 400 , the power to drive each screw should be carefully controlled so that screws as the fasten device won't damage the PCB 400 or the metal cover 100 . Ordinarily, in order to control the screw driving power within a safety range, a power testing apparatus is also used in the assembling process to assure the process reliability. Therefore, an improvement of a grounding apparatus targeting to minimize the number of elements and the assembling time without sacrificing the grounding effect is definitely welcome to the skilled persons in the art. | <SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, it is a primary object of the present invention to simplify a grounding apparatus used for grounding a PCB of an LCD, which can also save the time needed to assemble the grounding apparatus. An LCD of the present invention comprises an LCD panel, a plastic frame, a metal cover, a PCB, and a conductive film. The plastic frame is used to settle the LCD panel. The metal cover boxes the plastic frame and the LCD panel therein. The PCB is fixed on a lower surface of the plastic frame and connects to the LCD panel by using an FFC extending along a sidewall of the plastic frame. The conductive film taped on a grounding pin of the PCB and a sidewall of the metal cover is used to discharge the segregated charges on the PCB, through the metal cover, to the environment. Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. | 20040303 | 20070403 | 20050421 | 73552.0 | 1 | NGUYEN, THANH NHAN P | GROUNDING APPARATUS OF PRINT CIRCUIT BOARD IN A LIQUID CRYSTAL DISPLAY | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,790,877 | ACCEPTED | Keyed universal power tip and power source connectors | A keyed power source connector (32) and keyed device connector (14) that are backwards compatible, ensuring that the power rated device connectors can only mate with power source connectors power rated at or above the device connector power rating. One connector is formed as a plug, and the other connector is formed as a socket. The connectors have peripheral contoured body portions (16, 34) having a profile being a function of the respective connector power rating. A keyed portion (41, 62, 72, 82) of the power source connector plug will physically interfere with and not be receivable within a device connector socket when the device connector power rating exceeds the power source connector power rating. This connector system (10) ensures target portable electronic devices coupled to the device connector can not draw power exceeding the rating of the power source connector. | 1. An electrical device connector adapted to couple to a portable electronic device, comprising: a body having a plurality of conductors terminating at a first interface, a plurality of conductors terminating at a second interface adapted to couple to the portable electronic device; wherein the device connector is rated at a predetermined power rating, and has a peripheral contoured body portion having a profile being a function of the device connector power rating, the first interface being configured to be connectable to only a power source connector power rated at least as high as the device connector power rating. 2. The electrical device connector as specified in claim 1 wherein the peripheral contoured body portion is disposed about the first interface. 3. The electrical device connector as specified in claim 1 wherein the device connector power rating is commensurate with a power rating of a portable electronic device adapted to be coupled thereto. 4. The electrical device connector as specified in claim 1 wherein the device connector comprises an electrical component establishing the device connector power rating. 5. The electrical device connector as specified in claim 1 wherein the electrical component comprises a resistor. 6. The electrical device connector as specified in claim 1 wherein the device connector contoured body portion has a keyed portion adapted to interfere with a power source connector power rated below the device connector power rating. 7. The electrical device connector as specified in claim 1 wherein the keyed portion comprises a lobe. 8. In combination: a first connector having a first power rating and having a plurality of conductors terminating at a first interface; at least one second connector having a respective second power rating and having a plurality of conductors terminating at a respective second interface, wherein each of the second connectors has a third interface adapted to couple to a portable electronic device; wherein the first interface is shaped so as to mechanically and electrically couple to each of the second connector second interfaces, such that only those second connectors having a power rating at or below the power rating of the first connector can be coupled thereto. 9. The combination as specified in claim 8 wherein the second connectors second interfaces are shaped such that they are backward compatible with the first connector. 10. The combination as specified in claim 8 wherein the first connector first interface is shaped such that it is backward compatible with the plurality of second connectors. 11. The combination as specified in claim 8 wherein the first interface is a socket and the second interfaces are plugs. 12. The combination as specified in claim 8 wherein the first interface is a plug and the second interfaces are sockets. | FIELD OF THE INVENTION The present invention is generally related to electrical connectors, and more particularly to electrical connectors suitable for use with portable electronic devices having varying power requirements, including laptop computers, PDA's, mobile phones, MP3 players, digital cameras, and portable DVD players. BACKGROUND OF THE INVENTION In the consumer electronics market there are categories of portable electronic devices ranging from Cellular Telephones, to Personal Digital Assistants (PDA's), to Smart Phones, to Digital Cameras, to Portable DVD Players. Each device has specific power requirements from its' internal battery, or to be powered and/or charge this battery from an external power source, such as an AC wall receptacle or a DC power source. Universal power converters are now available in the market, including those offered by Mobility Electronics Inc. of Scottsdale Ariz., the Applicant of the present invention. Interchangeable device tips are provided, these tips being compatible with different portable electronic devices, and are adapted to receive power from a common power converter. Since the power requirement can vary greatly for each device, it is desirable in the universal power supply market to have a methodology of categorizing the power requirements into a series of power supplies. Each power supply can service the specific power range of the electronic device which is targeted. SUMMARY OF THE INVENTION The present invention achieves technical advantages as an electrical connector, a set of connectors, and a connector system whereby device connectors are backward compatible with power source connectors such that the device connectors can only be coupled to a power source connector rated at or above the power rating of the power source connector. For instance, a 35 Watt rated device connector can only be coupled with a power source connector rated at 35 Watts and above. Similarly, a 15 Watt device connector can only be coupled to power source connectors rated at 15 Watts and above. The portable electronic device to be powered from drawing power in excess of the power source connector and associated cabling. In one preferred embodiment, a set of device connectors are provided having conductors terminating at a device connector interface, this interface having a peripheral contoured body portion having a profile being a function of the device connector power rating. A mating power source connector, which may include a cable providing power thereto, has an interface also having a peripheral contoured body portion having a profile being a function of the power source connector power rating. Advantageously, the peripheral contoured body portions of these connectors are configured to mate with each other only when the power rating of the device connector meets or exceeds the power rating of the power source connector. The peripheral contoured body portions are preferable configured as a plug and socket arrangement, each socket having a predetermined power rating can only receive a plug having a compatible power rating. Advantageously, the power supplies can be developed for a specific power range, wherein device connectors mate to target portable electronic devices and to power source connectors and cables meeting or exceeding the power rating of these target portable electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts a set of device connectors and power source connectors each keyed to provide backward compatibility of the power source connectors with the device connectors; FIG. 2 is a perspective view of a 0-5 Watt rated power source connector keyed such that only device connectors rated at 5 Watts and below are adapted to electrically and physically connect thereto; FIG. 3 is a perspective view of a 0-5 Watt rated device connector adapted to receive only a power source connector rated at 5 Watts and above; FIG. 4 is a perspective view of a 0-15 Watt rated power source connector keyed to be received in device connectors rated at 15 Watts and below; FIG. 5 is a perspective view of a 0-15 Watt rated device connector keyed to receive power source connectors rated at 15 Watts and above; FIG. 6 is a perspective view of a 0-25 Watt rated power source connector keyed to be received in device connectors rated at 25 Watts and below; FIG. 7 is a perspective view of a 0-25 Watt rated device connector keyed to receive only power source connectors rated at 25 Watts and above; FIG. 8 is a perspective view of a 0-35 Watt rated power source connector keyed to be received in device connectors rated at 35 Watts and below; FIG. 9 is a perspective view of a 0-35 Watt rated device connector keyed to receive power source connectors rated at 35 Watts and above; FIG. 10 is a perspective cutaway view of the 0-5 Watt rated device connector securingly receiving the 35 Watt rated power source connector, illustrating a lower power rated device connector engaging a higher power rated source connector; FIG. 11 is a perspective cutaway view of the 0-25 Watt rated device connector securingly receiving the 35 Watt rated power source connector, illustrating a lower power rated device connector engaging a higher power rated source connector; FIG. 12 is a perspective cutaway view of the 0-15 Watt rated device connector theoretically being received within the 5 Watt rated power source connector, which is not possible due to the interference of the power source connector key portion 41 with the device connector key portion 23; and FIG. 13 is a perspective cutaway view of the 0-25 Watt rated device connector theoretically receiving a 5 Watt rated power connector, which is not possible due to the interference of the power source connector key portion 41 with the device connector key portion 25. FIG. 14 is a perspective view of one embodiment of a device connector fully assembled in a housing; FIG. 15 is an end perspective view of the connector of FIG. 14; FIG. 16 is an end view of the device connector and of connector 100; FIG. 17 is a side elevational view of the connector of FIG. 14; FIG. 18 is an end view of the connector of FIG. 14 illustrating the portable electronic device connector; FIG. 19 is a top view of the connector of FIG. 14; FIG. 20 is a bottom view of the connector of FIG. 14; FIG. 21 is an electrical schematic of one embodiment of the connector shown in FIG. 14 illustrating the p-out of the device connector 14 and the portable electronic device connector 110, along with design parameters for one embodiment of the present invention; FIG. 22 is an end view of the pin-out of the connector shown in FIG. 21; and FIG. 23 is an end view of the connector of 21 showing the p-out of the portable electronic device connector. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, there is generally shown at Keyed connector system 10 comprising a set of device connectors generally shown at 12 and a set of power source connectors generally shown at 30. By way of example, but without limitation to this preferred embodiment, the device connectors are shown to have a connector interface configured as a receptacle, and the power source connectors are configured as plugs. Of course, one skilled in the art will appreciate that the device connector interfaces could comprise of plugs, and the power source connectors could comprise of receptacles if desired. As shown in FIG. 1, the set of device connectors 12 is seen to comprise of separate and distinct device connectors 14 each having a peripheral contoured body portion 16 encompassing the terminating ends of a plurality of electrical conductors, shown as male pins 18. Four (4) different device connectors are shown at 20, 22, 24 and 26, having respective power ratings of 0-5 Watts, 0-15 Watts, 0-25 Watts, and 0-35 Watts. Each device connector also has a target device connector adapted to mate with target portable electronic devices. Similarly, the set of power source connectors 30 comprise individual power source connectors 32 each having a peripheral contoured body portion 34 encompassing a respective terminating end of plurality of electrical conductors, shown as female pins 36. In a preferred embodiment, the individual power source connectors 32 are shown as connectors 40, 42, 44, and 46, and having respective power ratings of 0-5 Watts, 0-15 Watts, 0-25 Watts, and 0-35 Watts. As visually depicted in FIG. 1, the 0-5 Watt rated power source connector 40 comprises a plug adapted to be received in only 0-5 Watt rated device connector 20, wherein the peripheral contoured body profile 16 of receptacle 20 is adapted to receive the peripheral contoured body profile 34 of plug 40. The 0-15 Watt rated power source connector 42, however, has a body profile 34 adapted to be received in both of receptacle connectors 20 and 22 since the power connector 42 is at least as great as the device connector power rating, and thus, can safely be mated with device connectors 20 and 22. Likewise, power source connector 44 is rated at 25 Watts, and thus, has a body profile 34 adapted to be coupled to and received within receptacle 20, 22 and 24. Since power source connector 44 is rated at 25 Watts, the device connectors 14 rated at 25 Watts and below, namely, connectors 20, 22 and 24, are adapted to receive and be safely electrically coupled to power source connector 44. The highest power rated power source connector depicted in this embodiment is power source connector 46, which has a body profile contour 34 adapted to be received within each of the device connectors 20, 22, 24 and 26 as each of these device connectors are rated at 35 Watts or below, which is at or below the power rating of the power source connector 46. Still referring to FIG. 1, there is shown that the device connector peripheral contoured body portions 16 are all keyed along the right side thereof, with 5 Watt rated device connector 20 having the largest keyed opening defined by key portion 41 configured as a lobe along the right side thereof such that it can receive all the power source connecters 40, 42, 44 and 46, as will be shown in more detail shortly. Looking at 0-15 Watt rated device connector 22, for instance, it can be appreciated that the key portion 23 of the body profile 16 is lower than key portion 21 of device connector 20. This key portion 23 is mechanically configured to receive corresponding key portion 42 of connector 43, key portion 45 of connector 44, and key portion 47 of connector 46, but is not adapted to receive the key portion 41 of connector 40 since power source connector 43 is rated lower than the device connector 22. It can be further appreciated that an additional peripheral contoured body key portion of device connector 26 is shown at 29 for the 35 Watt rated device connector 26. Likewise, a second peripheral contoured body key portion 49 of profile 34 is provided for the 35 Watt rated power source connector 46. The 35 Watt device connector 26 and power source connector 46 have these additional keyed portions 29 and 49 to ensure that the 35 Watt device connector 26 can only mate to the 35 Watt rated power source connector 46. Referring now to FIG. 2, there is shown a perspective view of the 5 Watt rated device connector 40 configured as a plug. The peripheral contoured body portion 34 includes the body key portion 41 and an alignment tab 50 providing the keying so as to only be connectable to device connector 20, as previously described. Power source connector 40 is further seen to include a cable portion 56 including a plurality of connectors, each connector coupled to and terminating at one of the female interface pins 36 adapted to receive power from a power source, such as a power converter (not shown). An elongated projection 57, shown as a tab, extending laterally across an upper portion of the connector body 58 is adapted to be releasingly secured within one of the device connectors, such as device connector 20, whereby a corresponding body slot 31 flexibly receives the upwardly corresponding projection 57. A similar projection tab 57 extends from the opposing surface of body 58 (not shown) which is releasingly securable within the opposing slot 31 shown in FIG. 3. The peripheral contoured body portion 16 of device connector 20 has a slot 51 adapted to securingly receive the corresponding tab 50 of the power source connector received therein, and also a keyed portion 53 adapted to receive all of the power source connectors having a power rating greater than the 5 Watt power rating of device connector 20. Referring to FIG. 4, there is shown a perspective view of the power source connector 42 having a power rating of 0-15 Watts, having a keyed portion 62 and 64 configured to be received in only 5 Watt rated device connector 20 and 15 Watt rated connector 22. FIG. 5 shows a perspective view of the device connector 22 having a contoured peripheral body portion 16 including a keyed portion 66 and 68. Referring now to FIG. 6, there is shown a perspective view of the 0-25 Watt power source connector 44 whereby the peripheral contoured body portion 34 has a keyed portion 72 and 74. This power source connector can only be received in device connectors 20, 22 and 24. Referring to FIG. 7, there is shown a peripheral view of the 0-25 Watt rated device connector 24, whereby the peripheral contoured body portion 16 has a keyed portion 76 and 78. The 0-25 Watt rated device connector 24 is adapted to couple to only the power source connectors having a rating of at least 25 Watts, namely, the 0-25 Watt rated power source connector 44 and the 0-35 Watt power source connector 46. Referring now to FIG. 8, there is shown a perspective view of the 0-35 Watt rated device connector 46, whereby the peripheral contoured body portion 34 has a keyed portion 82 and 84. Referring to FIG. 9, there is shown a perspective view of the 0-35 Watt device connector 26, whereby the peripheral contoured body portion 16 has a keyed portion 86 and 88. This 35 Watt rated device connector 26 is adapted only receive within the 0-35 Watt power source connector 46, as connector 46 is rated to provide at least 35 Watts of power. Advantageously, each of the power source connectors 40, 42, 44 and 46 are backward compatible such that the power source connectors 32 can only be received within device connectors 14 having a power rating no greater than a connecting power source connector. Advantageously, a target portable electronic device having a power rating, for example, of 25 Watts can only be connectable to a power source connector rated at least as high as 25 Watts so as to not draw more power than the rating of the power source connector 32. Referring now to FIG. 10, there is shown one example of the 0-5 Watt rated device connector 20 receiving a 35 Watt power rated source connector 46. The respective keying of device connector 20 and power source connector 46 are shown to not provide an interference fit, and thus allow the secure reception of plug 46 into receptacle 20. Referring to FIG. 11, there is shown an example of the 0-25 Watt rated device connector 24 receiving the 35 Watt rated power source connector 44. Again, the respective key portions of plug 44 and receptacle 24 do not provide an interference fit, and thus allow the secure connection to each other. Referring now to FIG. 12, there is shown an illustration of the 0-15 Watt rated device connector 22 physically interfering with a 5 Watt rated power source connector 40, the interference being shown at 90. This, illustration shows the interference of key portion 41 of power source connector 40 with the key portion 23 of device connector 22. Because of this interference, these two connectors can not mate, which advantageously ensures that a higher power rated device connector 14 can never be connected to a lower power rated power source connector 32. Referring to FIG. 13, there is shown yet another illustrating whereby the 0-25 Watt rated device connector 24 would have an interference with the 5 Watt rated power connector 40. Specifically, key portion 41 of power source connector 40 can not be received within the 25 Watt rated device connector 24 because device connector key portion 25 interferes with the key portion 41 of power source connector 40, as shown. Referring now to FIG. 14, there is shown at 100 a tip connector including the 0-15 watt device connector 22 (see FIG. 5) packaged in a housing 102, and a portable electronic device connector 110. The plurality of pins 18 are shown protruding from a socket 104 encompassed by the contoured peripheral body portion 16 including keyed portions 66 and 68. Referring now to FIG. 15, there is shown a perspective rearview of tip connector 100 depicting connector 110 adapted to connect to a portable electronic device to be powered. The shape and/or pin-out of each tip connector 100 will vary from device to device, depending on the interface requirement of such portable electronic device to be powered, and the power rating of the tip connector 100. FIG. 16 shows an end view of tip connector 100 further depicting the profile of the socket 104, which as previously described, is adapted to receive the power source connector having, in this embodiment, a power rating of 15 watts and above. FIG. 17 shows a side elevational view of tip connector 100. FIG. 18 shows an end view of connector 100 viewing the connector 110. FIG. 19 is a top view of connector 100, and FIG. 20 is a bottom view of connector 100. Referring now to FIG. 21, there is shown an electrical schematic diagram of one embodiment of tip connector 100, showing one possible pin-out assignment for each of the pins 18 and the pins of portable electronic device connector 110. As shown in FIG. 21, a resistive device network is established between pins 1, 2 and 5 of connector 14 comprising resistors R1 and R2. The values of the resistors R1 and R2 are selected to provide a desired output voltage and desired output current. Shown in this embodiment is an associated parts list, configured such that the output voltage is shown to be 5.21 volts+/−2.5%, output current 0.49 amps+/−5%, whereby resistors R1 and R2 are 1% 1/16 watt resistors, such that tip connector 100 is configured as a 8 watt power rated connector. Of course, for connectors adapted to power different portable electronic devices, the particular pin-out of connector 110 may vary, and the component values and design parameters are configured to meet the particular requirements of such intended portable electronic device to be powered. Referring to FIG. 22, there is shown an end view of device connector 14 of the tip connector 100 shown in FIG. 21, and FIG. 23 depicts the end view of portable electronic device connector 110 in the embodiment shown in FIG. 21, showing the pin-outs of pins 1-4. Though the invention has been described with respect to a specific preferred embodiment, many variations and modifications will become apparent to those skilled in the art upon reading the present application. It is therefore the intention that the appended claims be interpreted as broadly as possible in view of the prior art to include all such variations and modifications. | <SOH> BACKGROUND OF THE INVENTION <EOH>In the consumer electronics market there are categories of portable electronic devices ranging from Cellular Telephones, to Personal Digital Assistants (PDA's), to Smart Phones, to Digital Cameras, to Portable DVD Players. Each device has specific power requirements from its' internal battery, or to be powered and/or charge this battery from an external power source, such as an AC wall receptacle or a DC power source. Universal power converters are now available in the market, including those offered by Mobility Electronics Inc. of Scottsdale Ariz., the Applicant of the present invention. Interchangeable device tips are provided, these tips being compatible with different portable electronic devices, and are adapted to receive power from a common power converter. Since the power requirement can vary greatly for each device, it is desirable in the universal power supply market to have a methodology of categorizing the power requirements into a series of power supplies. Each power supply can service the specific power range of the electronic device which is targeted. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention achieves technical advantages as an electrical connector, a set of connectors, and a connector system whereby device connectors are backward compatible with power source connectors such that the device connectors can only be coupled to a power source connector rated at or above the power rating of the power source connector. For instance, a 35 Watt rated device connector can only be coupled with a power source connector rated at 35 Watts and above. Similarly, a 15 Watt device connector can only be coupled to power source connectors rated at 15 Watts and above. The portable electronic device to be powered from drawing power in excess of the power source connector and associated cabling. In one preferred embodiment, a set of device connectors are provided having conductors terminating at a device connector interface, this interface having a peripheral contoured body portion having a profile being a function of the device connector power rating. A mating power source connector, which may include a cable providing power thereto, has an interface also having a peripheral contoured body portion having a profile being a function of the power source connector power rating. Advantageously, the peripheral contoured body portions of these connectors are configured to mate with each other only when the power rating of the device connector meets or exceeds the power rating of the power source connector. The peripheral contoured body portions are preferable configured as a plug and socket arrangement, each socket having a predetermined power rating can only receive a plug having a compatible power rating. Advantageously, the power supplies can be developed for a specific power range, wherein device connectors mate to target portable electronic devices and to power source connectors and cables meeting or exceeding the power rating of these target portable electronic devices. | 20040302 | 20051220 | 20050908 | 66608.0 | 2 | PRASAD, CHANDRIKA | KEYED UNIVERSAL POWER TIP AND POWER SOURCE CONNECTORS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,791,025 | ACCEPTED | Green emitting phosphor material and plasma display panel using the same | A green emitting lanthanum aluminate phosphors activated with manganese and alkali halide for plasma display panels (PDP) having an empirical formula: La2-x-yB22O36:Mnx.Ay wherein: A=Li, Na or K; B═Al or Al+Ga; and 0.01≦x≦0.1 and 0.01≦y≦0.1 is provided. The phosphor has a band emission in green region, peaking at 515 nm when excited by 147 and 173 nm radiation from Xenon gas mixture, a uniform particle size distribution (0.01 to 10 microns), which is a size distribution appropriate for thin phosphor screens required for a variety of flat panel display and lamp applications. They exhibit high brightness, good color saturation, good stability and shorter persistence under VUV excitation. | 1. A green emitting Mn and alkali metal activated lanthanum aluminate phosphor having the empirical formula: La2-x-yB22O36:Mnx.Ay wherein: A=Li, Na or K; B═Al or Al+Ga; and 0.01≦x≦0.1 and 0.01≦y≦0.1. 2. The green emitting Mn and alkali metal activated lanthanum aluminate phosphor of claim 1, prepared by a method comprising the steps of: mixing an alkali metal salt as a source of alkali metal, manganese salt as a source of manganese, lanthanum salt as a source of lanthanum and a alumina as source of aluminum; reacting a dilute solution comprising a source of alkali halides, a source of lanthanum, a source of manganese and an organic precursor providing a source of aluminum, in an acid medium to form a gel; converting said gel into a gel powder by removing excess water; and thermally decomposing the powder at specified temperatures to produce said phosphor. 3. The phosphor of claim 2, wherein said source of lanthanum is selected form the group consisting of: lanthanum oxalate, lanthanum nitrate, lanthanum oxide, and mixtures thereof; said alkali halide metal is selected from the group consisting of: alkali halide, alkali nitrate, alkali carbonate, alkali hydroxide, and mixtures thereof; said source of aluminum is selected form the group consisting of: aluminum oxide, aluminum isopropoxide, aluminum s-butoxide, and mixtures thereof. 4. The phosphor of claim 2, wherein said gel is thermally decomposed in an open atmosphere at a temperature from abut 1000° C. to about 1400° C. and then at a temperature from about 1000° C. to about 1300° C. in forming gas. 5. The phosphor of claim 2, wherein said gel is dried to form said gel powder prior to thermal decomposition. 6. The phosphor of claim 2, wherein said gel is vacuum dried to form said gel powder as an aerogel prior to thermal decomposition. 7. The phosphor of claim 2, wherein said gel is spray dried to form said gel powder prior to thermal decomposition. 8. The phosphor of claim 1, wherein said phosphor has a particle size from about 0.01 microns to about 10.0 microns. 9. The phosphor of claim 1, wherein said phosphor exhibits a relative intensity (AU) at 147 nm excitation from about 90 to about 100 and relative intensity (AU) at 173 nm excitation from about 90 to about 105 with half width from about 23 to about 25 nm. 10. The phosphor of claim 1, wherein said phosphor exhibits a persistence from about 7 ms to about 10 ms. 11. The phosphor of claim 1, wherein said phosphor exhibits color coordinates of x from about 0.116 to about 0.136 and y from about 0.752 to about 0.782. 12. A method of producing a green emitting Mn and alkali metal activated lanthanum aluminate phosphor having the empirical formula: La2-x-yB22O36:Mnx.Ay wherein: A=Li, Na or K; B═Al or Al+Ga; and 0.01≦x≦0.1 and 0.01≦y≦0.1; and wherein said method comprises the steps of: mixing alkali metal salt as a source of alkali, manganese salt as a source of manganese, lanthanum salt as a source of lanthanum and alumina as source of aluminum; reacting a dilute solution comprising a source of alkali halides, a source of lanthanum, a source of manganese and an organic precursor providing a source of aluminum, in an acid medium to form a gel; converting said gel into a gel powder by removing water; and thermally decomposing the powder at specified temperatures to produce said phosphor. 13. The method of claim 12, wherein said source of lanthanum is selected form the group consisting of: lanthanum oxalate, lanthanum nitrate, lanthanum oxide, and mixtures thereof; said alkali halide metal is selected from the group consisting of: alkali halide, alkali nitrate, alkali carbonate, alkali hydroxide, and mixtures thereof; said source of aluminum is selected form the group consisting of: aluminum oxide, aluminum isopropoxide, aluminum s-butoxide, and mixtures thereof. 14. The method of claim 12, wherein said gel is thermally decomposed in an open atmosphere at a temperature from abut 1000° C. to about 1400° C. and then at a temperature from about 1000° C. to about 1300° C. in forming gas. 15. The method of claim 12, wherein said gel is dried to form said gel powder prior to thermal decomposition. 16. The method of claim 12, wherein said gel is vacuum dried to form said gel powder as an aerogel prior to thermal decomposition. 17. The method of claim 12, wherein said gel is spray dried to form said gel powder prior to thermal decomposition. 18. The method of claim 12, wherein said phosphor has a particle size from about 0.01 microns to about 10.0 microns. 19. The method of claim 12, wherein said phosphor exhibits a relative intensity (AU) at 147 nm excitation from about 90 to about 100 IS and relative intensity (AU) at 173 nm excitation from about 90 to about 105 with half width from about 23 to about 25 nm. 20. The method of claim 12, wherein said phosphor exhibits a persistence from about 7 ms to about 10 ms. 21. The method of claim 12, wherein said phosphor exhibits color coordinates of x from about 0.116 to about 0.136 and y from about 0.752 to about 0.782. 22. The method of claim 12, wherein said source of lanthanum is lanthanum oxalate, source of alkali halide is selected from the group consisting of: alkali halide, alkali nitrate; said source of manganese is selected from the group consisting of: manganese nitrate and source of aluminum is aluminum oxide. 23. The method of claim 12, wherein said source of lanthanum is lanthanum oxalate; said source of manganese halide is manganese fluoride; said alkali halide is alkali fluoride; and said source of aluminum is aluminum oxide. 24. The method of claim 12, wherein said powder is thermally decomposed in an open atmosphere at 1300° C. and then at a temperature equal 1200° C. in a forming gas contains 4.0 to 5.0% of H2 and remaining N2. 25. The method of claim 12, wherein said gel is dried to form a xerogel and said xero-gel is crushed to form a powder prior to thermal decomposition. 26. The method of claim 12, wherein said gel is vacuum dried to form aero-gel and said aero-gel is crushed to form a powder prior to thermal decomposition. 27. The method of claim 12, wherein said gel is spray dried to form gel powder and said gel powder is crushed to form a powder prior to thermal decomposition. 28. The method of claim 12, wherein said gel is sprayed ultrasonically and dried to form gel powder and said gel powder is crushed to form a powder prior to thermal decomposition 29. The method of claim 12, wherein said phosphor has a particle size in the range of 0.01 to 10.0 microns. 30. The method of claim 25, wherein said powder has a particle size in the range of 0.05 to 5.0 microns. 31. The method of claim 26, wherein said powder has a particle size in the range of 0.05 to 5.0 microns. 32. The method of claim 27, wherein said powder has a particle size in the range of 0.01 to 3.0 microns. 33. The method of claim 28, wherein said powder has a particle size in the range of 0.01 to 0.02 microns. 34. The method of claim 12, where said phosphor comprises from about 1.8 mole to about 1.98 mole of lanthanum, from about 0.01 mole to about 0.1 mole of manganese, and about 0.01 mole to about 0.1 mole of alkali halide and 22.0 mole of aluminum. 35. A phosphor material for a plasma display panel comprising a composition represented by the formula: La2-x-yB22O36:Mnx.Ay wherein: A=Li, Na or K; B═Al or Al+Ga; and 0.01≦x≦0.1 and 0.01≦y≦0.1, which phosphor emits green light when excited by vacuum ultra violet light of wavelength in the range of 100 nm to 200 nm. 36. An improved plasma display panel (PDP), having a front plate with electrodes, dielectric layer, a thin protecting layer (MgO), a back plate with electrodes, reflective layer, ribs, phosphors, and a plurality of discharge spaces formed between the front and back plates having phosphor layers, wherein the improvement comprises: a plasma display panel which includes a green emitting phosphor material comprising a composition represented by the formula: La2-x-yB22O36:Mnx.Ay wherein: A=Li, Na or K; B═Al or Al+Ga; and 0.01≦x≦0.1 and 0.01≦y≦0.1, which phosphor emits green light when excited by vacuum ultra violet light of wavelength in the range of 100 nm to 200 nm. 37. The phosphor of claim 1, having the empirical formula: La2-x-yAl22O36:Mnx.Ay wherein: A=Li, Na, K and 0.01≦x≦0.1 and 0.01≦y≦0.1. 38. The phosphor of claim 1, having the empirical formula: La2-x-yB22O36:Mnx.Ay wherein: A=Li, Na or K; B═Al+Ga; and 0.01≦x≦0.1 and 0.01≦y≦0.1. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the preparation and growth of small size particles Mn2+ and alkali halide doped lanthanum aluminate phosphor by solid sate and sol-gel methods. More specifically, the present invention provides green emitting Mn2+ and alkali halide doped lanthanum aluminate phosphor and process by thermally decomposing salts of lanthanum, manganese, alkali halide and alumina or sol-gel powders. 2. Description of the Related Art The plasma display panel (PDP) as a medium of large format (60+″) television (TV), particularly high definition TVs (HDTV's) is gaining attention over cathode ray tube (CRT) based TVs due to its' high performance and scalability. Although, CRT works with less power and having better picture quality, it has size limitation. Larger screens (CRT) of diagonal size more than 40 inches have larger depth and very heavy. Conversely, diagonal size of PDP is growing day by day, as there is no problem with depth and weight. The structure of a PDP, which is known in the art, is described in FIGS. 1a and 1b. FIGS. 1a and 1b represents the cross section of an AC PDP. The plasma display has of two large area glass substrates 11, 16. Front plate 11 is made with sustain electrode 12 and scanning electrode 13, covered with thick dielectric layer 14 and a thin protection layer (MgO) 15. Back plate 16 is made with address electrodes 17, reflective layer 18, barrier ribs 19 and red phosphor 20R (Y,Gd)BO3:Eu2+, green phosphor 20G ZnSiO4:Mn2+ (P1) or the blend of ZnSiO4:Mn2+ and Y,GdBO3:Tb3+, blue phosphor 20B BaMgAl10O17:Eu2+ coated by screen printing or ink jet process. Both the glass plates are frit sealed together and filed the space 21 with Xe, Ne gas mixture. When voltage isapplied, a discharge is developed in the space 21 producing Vacuum UV (147 and 173 nm). When phosphors 2ORGB are excited by VUV photons, they emit respective visible radiations viewed through the transparent front plate as an image 22. The luminous efficiency of a PDP depends upon various factors including materials such as phosphors, gas mixture, dielectric layer, reflective layer, black matrix, electrodes, cell dimension and shape, nature, size and shape of electrodes, address waveforms, operating voltages, etc. The performance and lifetime of a PDP is strongly related to the nature of phosphors and their resistance to energetic discharge ions, electrons, and solarization from VUV arising from Xe/Ne gas discharge. Compared to standard emissive display such as CRTs (5-6 Im/W), the efficiency of a PDP is low (1-2 Im/W). To improve the overall efficiency of PDPs, considerable developments related to materials, design, process and electronics are under way. Efforts are also being made to develop new phosphors as well as to improve existing phosphors. Due to vacuum UV specific wavelengths available from Xe discharge (147 nm and 173 nm), only a limited number of lamp phosphors are suitable for PDP applications. In addition to high luminous efficiency, PDP phosphors should have longer life or stability, required persistence, suitable color coordinates, color temperature, and color saturation. The main application of large area plasma displays will be HDTV and high information content presentation. HDTV and similar type of display devices should have phosphors with low dielectric constant, required decay time, high resolution and high brightness for high performance. Screens coated in a close rib structure or closed cell structure with small particles exhibit higher packing density and also need lesser binder content. Persistence value, which is defined as being 10% of the initial brightness, is another concern in selecting a phosphor, and should be between 4 and 9 ms, also. The three phosphors (red, green and blue) currently used in PDP's have different dielectric constants and particle morphology. Due to their physical nature, all of the three phosphors need different rheology of phosphor paste as well as different screening processes. In PDP applications these phosphors exhibit different electrical characteristics in a finished panel. This results in compromises in the performance of the display. HDTV and similar type of devices should have high resolution and higher brightness for better performance. This can be achieved only with thin phosphor screens formed with very small phosphor particles (1-5 microns) in a close rib structure particularly in the case of PDP's. Screens with small particles have a higher packing density and also require lower binder content. Manganese activated zinc silicate phosphor with or without terbium activated yttrium gadolinium borate is currently used in plasma display panels (PDP) as a green emitting component due to its availability and high quantum efficiency. The higher dielectric constant of zinc silicate phosphor is of particular concern as it charges more than its' blue and red counterparts and this results in a higher sustainer voltage. When compared with red and blue emitting phosphors, zinc silicate phosphor also exhibits longer persistence, lower dielectric constant, negative discharge and faster saturation with the VUV flux. Another suitable green candidate, Tb activated yttrium gadolinium borate, which shows lower color purity is described in U.S. Pat. No. 6,004,481. As a trade off, PDP industry is adopting the blend of P1 and Tb activated borate. Efforts are being made to develop new phosphors to satisfying all requirements and replace existing Mn activated zinc silicate phosphor or the blend of silicate and borate. Some other phosphor candidates based on alkali halide aluminates are being suggested in Phosphor Handbook. U.S. Pat. Nos. 4,085,351; 5,868,963; and 6,423,248 B1 disclose the application of manganese activated aluminate phosphor with either of calcium, strontium, barium, magnesium or zinc in a gaseous discharge light-emitting element. European Patent No. EP 0 908 502 A1 teaches the preparation of barium or strontium magnesium aluminate by firing respective oxides or carbonate in presence of flux (AlF3) at 1450° C. for 48 hours (total time). International Patent Application No. WO 98/37165 describes a method of making oxygen containing phosphor powder, which includes alkaline earth aluminates by spray techniques. European Patent No. EP 1 359 205 A1 describes the method of preparation of various green emitting phosphors has La, Mg, Zn aluminates with Tb, Mn as activators. Other related aspects to such phosphors are described in U.S. Pat. Nos. 4,150,321; 5,989,455; and 6,222,312 B1; European Patent No. 0 697 453 A1; International Patent No. WO 98/37165 by Hampden-Smith Mark, et al.; and publications entitled (1) “Fluorescence in α-Al2O3-like materials of K, Ba, La activated with Eu2+ and Mn2+” by M. Tamatani, Jap. J. Applied Physics, Vol. 13, No.6, June 1974 pp950-956; (2) “The behavior of phosphors with aluminate host lattices” by J. L. Sommerdijk and A. L. N. Stevels, Philips Tech. Review Vol. 37, No. 9/10, 1977 pp 221-233; and (3) “Principal phosphor materials and their optical properties” by M. Tamatani in “Phosphor Handbook” edited by S. Shionoya and W. M. Yen, CRC Press (1999) pp. 153-176. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a phosphor and method of preparation of manganese activated and alkali halide lanthanum aluminate phosphor having the empirical formula: La2-x-yB22O36:Mnx.Ay wherein: A=Li, Na or K; B═Al or Al+Ga; and 0.01≦x≦0.1 and 0.01≦y≦0.1. The phosphor is prepared by thermally decomposing the powder obtained by method including the steps of: mixing a source of alkali, such as, an alkali metal salt, a source of manganese, a source of lanthanum and a source of aluminum; reacting a dilute solution comprising a source of alkali halides, a source of lanthanum, a source of manganese and an organic precursor providing a source of aluminum, in an acid medium to form a dilute gel (sol-gel process); and converting the dilute gel into a xerogel powder (room temperature drying); converting the dilute gel into an aerogel powder (vacuum drying); or converting the dilute gel into a gel powder (spray drying), at specified temperatures, having a band emission in green region, peaking at 515-516 nm when excited by 147 and 173 nm radiation from Xenon gas mixture. The present invention also provides comparative performance data on the lanthanum aluminate phosphors that are activated with manganese (Mn2+) and alkali halide such as lithium (Li+) synthesized by two different processes: conventional solid-state reaction process (0.1 to 10 microns) and sol-gel process (0.01 to 5 microns). Phosphor materials are extremely sensitive to impurities, even at ppb levels. The low-temperature process minimizes the potential for cross contamination. Some of the unwanted impurities left in the materials from high temperature calcination may pose a threat to the performance of a phosphor. As the size of the phosphor particle decreases, the probability of electron and hole capture to the impurity increases and the e-h localization enhances the recombination rate via the impurity. The optimum impurity concentration (activator) level can be further increased with small particle size. This can be achieved by starting with sub micron size starting chemicals or sol gel process. The green phosphor of the present invention is capable of absorbing the photons of vacuum ultra violet light and converting them into photons of visible light. Accordingly, the green phosphor described herein is suitable to use in lamps and displays. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1a represents cross sectional view of AC plasma display panel. FIG. 1b represents cross sectional view of single cell with three different phosphors. FIG. 2 shows X-ray diffraction pattern of Mn and Li activated lanthanum aluminate phosphor. FIG. 3 illustrates scanning electron micrographs of Mn and Li activated lanthanum aluminate phosphors. FIG. 4 presents the particle size distribution of Mn and Li activated lanthanum aluminate phosphor of present invention. FIG. 5 shows excitation spectra of Mn and Li activated lanthanum aluminate phosphor of present invention and Mn activated zinc silicate phosphor recorded at room temperature in VUV region after excitation with continuous D2 lamp. FIG. 6 shows the spectral energy distribution of custom-made VUV lamps (147 and 173 nm) with out filters. FIG. 7 shows emission spectra of Mn and Li activated lanthanum aluminate phosphor of present invention and Mn activated zinc silicate phosphor excited at 147 nm. The emission was recorded at room temperature. FIG. 8 shows persistence of Mn and Li activated lanthanum aluminate phosphors recorded at room temperature (excitation source custom made Xenon lamp with 147 nm filter). FIG. 9 represents the variation in intensity with the concentration of Mn and Li in lanthanum aluminate phosphors. FIG. 10 shows the degradation in intensity of Mn and Li activated lanthanum aluminate phosphors exposed to high energy VUV lamp. DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method of preparation and growth of small size particles Mn2+ and alkali halide doped lanthanum aluminate phosphor, particularly green emitting Mn2+ and alkali halide doped lanthanum aluminate phosphors, by solid sate and sol-gel methods. The method includes the steps of thermally decomposing salts of lanthanum, manganese, alkali halide and alumina or sol-gel powders obtained from dilute solution comprising a source of an lanthanum, a source of manganese and an organic precursor providing a source of aluminum, in an acid medium (sol-gel process) or xerogel powder (drying gel from sol-gel process at room temperature) or aerogel powder (drying the gel from sol-gel in vacuum); or gel powder obtained by spray drying, at temperature (1000 to 1400 C) for 2 to 6 hours in air and refired at 1000-1300° C. in presence of forming gas (95.5% N2 and 4.5% H2) for 2 to 6 hours. In a preferred embodiment, the green emitting Mn and alkali metal (i.e., Li, Na or K) activated lanthanum aluminate phosphor according to the present invention has the empirical formula: La2-x-yAl22O36:Mnx.Ay wherein: A=Li, Na, K and 0.01≦x≦0.1 and 0.01≦y≦0.1. In another preferred embodiment, the green emitting Mn and alkali metal (i.e., Li, Na or K) activated lanthanum aluminate phosphor according to the present invention has the empirical formula: La2-x-yB22O36:Mnx.Ay wherein: A=Li, Na or K; B═Al+Ga; and 0.01≦x≦0.1 and 0.01≦y≦0.1. The green emitting manganese-activated lanthanum aluminate phosphor particles have a uniform particle size distribution (0.01 to 10 μm) that are suitable for use in plasma display panels (PDP). Such particles can be prepared from respective oxides, nitrates, oxalates and organic precursors which form small particles that improve the performance parameters of higher brightness, shorter persistence, better stability, longer life and good color saturation in PPD applications. There are a number of display applications where a phosphor with high brightness, shorter persistence, colors purity (saturation), better stability and long life span (time of operation) would significantly improve the display's performance. In a display, the green component is very important, as the human eye photonic response has its peak sensitivity at approximately 535 nm (green component of the visible spectrum). Since commercially available phosphor based on Mn activated zinc silicate or barium magnesium aluminate and terbium activated yttrium, gadolinium borate fail to satisfy all the above requirements, a new phosphor and its synthesis process that overcomes the above limitations was developed. The green phosphor according to the present invention is capable of absorbing the photons of vacuum ultra violet light and converts into photons of visible light and is suitable to use in lamps and displays. Further, the small size phosphor particles are particularly suitable for use in applications in which a high packing density is required. The result of this development effort is the basis of the present invention. This invention provides Mn2+ and alkali halide1+ activated lanthanum aluminate phosphor, method of synthesizing and uses the same in PDP's. The phosphor is prepared by a method having the steps of: mixing an alkali metal salt as a source of alkali metal, manganese salt as a source of manganese, lanthanum salt as a source of lanthanum and a alumina as source of aluminum; reacting a dilute solution comprising a source of alkali halides, a source of lanthanum, a source of manganese and an organic precursor providing a source of aluminum, in an acid medium to form a gel; converting said gel into a gel powder by removing excess water; and thermally decomposing the powder at specified temperatures to produce said phosphor. The source of lanthanum can be lanthanum oxalate, lanthanum nitrate, lanthanum oxide, or mixtures thereof; the alkali metal salt can be alkali halide, alkali nitrate, alkali carbonate, alkali hydroxide, or mixtures thereof; the source of aluminum can be aluminum oxide, aluminum isopropoxide, aluminum s-butoxide, or mixtures thereof. The gel can be sprayed ultrasonically and dried, i.e., spray dried, to form a gel powder or vacuum dried to form the gel powder as an aerogel prior to thermal decomposition. The gel can also be dried to form a xerogel and the xero-gel can be crushed to form a powder prior to thermal decomposition. The gel can be thermally decomposed in an open atmosphere at a temperature from abut 1000° C. to about 1400° C. and then at a temperature from about 1000° C. to about 1300° C. in forming gas. Preferably, the phosphor has a particle size from about 0.01 microns to about 10.0 microns and exhibits a relative intensity (AU) at 147 nm excitation from about 90 to about 100 and relative intensity (AU) at 173 nm excitation from about 90 to about 105 with half width from about 23 to about 25 nm, a persistence from about 7 ms to about 10 ms, color coordinates of x from about 0.116 to about 0.136 and y from about 0.752 to about 0.782. Accordingly, the phosphor can be prepared by thermally decomposing a powder obtained by mixing a source of alkali, such as, an alkali metal salt, a source of manganese, a source of lanthanum and a source of aluminum; reacting a dilute solution comprising a source of alkali halides, a source of lanthanum, a source of manganese and an organic precursor providing a source of aluminum, in an acid medium to form a dilute gel (sol-gel process); and converting the dilute gel into a xero-gel powder (room temperature drying); converting the dilute gel into an aero-gel powder (vacuum drying); or converting the dilute gel into a gel powder (spray drying), at specified temperatures. The formation of the lanthanum aluminate solid solution is critical and is highly dependent on the reaction temperature and conditions. In this invention, an aqueous based process is adopted along with solid state by considering the cost and availability of the starting chemicals. Since the purity of starting chemicals is very important to the synthesis of phosphors, the starting chemicals are typically 99.9-99.999% in purity. It is important to minimize the concentration of specific contaminants such as Fe, Co, Ni, which can seriously degrade the phosphor performance. Required metal (La,Mn,Li,Na and K) solutions are also prepared by mixing appropriate amounts of respective metal nitrates in a lukewarm Di water to obtain 0.05-0.1M solutions. The metal hydroxide precursor was prepared by precipitating an aqueous solution of metal chloride or metal nitrate (0.01-0.05M) in water by the addition of a base such as ammonium hydroxide to the solution. Stoichioemetric quantities of metal solutions and aluminium isopropoxide or aluminum s-butoxide are mixed. The metal/isopropoxide or aluminum s-butoxide solution is transferred to a round bottom flask and peptized at 80-100° C. for 9-18 hours in a stirrer mantle. In the present invention inorganic acid such as HNO3 or HCl have been employed to maintain a low pH which is required to effect gelation. After the pepitization, sol/gels are left in a container until they become a thick gel (3-5 days) and then a xerogel. Aerogels are also prepared from the same dilute gels by extracting the water and other solvents in a vacuum through a cold trap. These xerogels or aerogels are transferred into a lab oven at 60-70° C. and left for a day or until becoming powder. This step is inserted to accelerate the removal of any resisdual solvent. Gel powders are also prepared by spray drying. Dilute gels are sprayed through a fine nebulizer into a 4″ diameter glass tubing which has been heated to 120-150° C. An alternate process for forming particles can be accomplished using an ultrasonic aerosol generator. After drying, gel powder is collected and fired for 2 hours at 400° C. to burn-out residual organic components. Required amounts of metal salts such as oxalates, carbonates, fluorides of La, Li, Mn are mixed with aluminum oxide preferably gamma-alpha alumina of 0.01-0.02 micron powder with surface area 100 m2/g and flux materials such as ammonium fluoride in a mortor and psetle. The charge contains mixed powders of solid state or powders obtained from sol-gel process is transferred into high grade alumina crucibles and calcined in air at 1000 to 1400° C. for 2 to 6 hours. The fired powders are transferred in to high grade alumina boats and refired in a tube furnace in presence of foriming gas (4.5% of H2 and 95.5% of N2) at 1000 to 1300° C. for 2 to 6 hours. Reducing atmosphere such as forming gas or carbon mooxide or equvalent helps to change the Mn3+ and higher states to divalent manganese state (Mn2+). The powder can be thermally decomposed in an open atmosphere at 1300° C. and then at a temperature equal 1200° C. in a forming gas contains 4.0 to 5.0% of H2 and remaining N2. Preferably, the phosphor has a particle size in the range of 0.01 to 10.0 microns. The powder has a particle size in the range of 0.05 to 5.0 microns, preferably 0.01 to 3.0 microns, more preferably, 0.01 to 0.02 microns. Preferably, the phosphor has from about 1.8 mole to about 1.98 mole of lanthanum, from about 0.01 mole to about 0.1 mole of manganese, and about 0.01 mole to about 0.1 mole of alkali halide and 22.0 mole of aluminum. FIG. 1a represents cross sectional view of AC plasma display panel. FIG. 1b represents cross sectional view of single cell with three different phosphors. FIG. 2 shows X-ray diffraction pattern of Mn and Li activated lanthanum aluminate phosphor. Referring to FIG. 2, X-ray powder diffraction data on sample fired at 1300° C. and refired at 1200° C. (N2+H2) along with standard data from lanthanum manganese aluminum oxide (JCPDF 77-0334) is provided. The lines corresponding to lanthanum aluminate phase are more prominent above 1000° C. of firing temperature. Since the luminescence of a phosphor depends on the shape, size, crystallinity, defects and grain boundaries, the morphology and particle size distribution (PSD) of all the samples prepared at various conditions were studied. FIG. 3 illustrates scanning electron micrographs of Mn and Li activated lanthanum aluminate phosphors. The scanning electron micrographs of phosphor samples prepared from inorganic salts are studied with the help of Hitachi S-4500 scanning electron microscope. Referring to the photomicrographs in FIG. 3, one can observe that the phosphor particles are very uniform in size and well crystallized. FIG. 4 presents the particle size distribution of Mn and Li activated lanthanum aluminate phosphor of present invention. FIG. 4 shows PSD of these phosphors measured on particle size analyzer, Horiba LA-190. It is observed that all the particles are below 10 microns with mean diameter 2.0 microns and median 1.5 microns. The samples are washed with water after calcination to eliminate very small particles (<0.05 microns) as well as un-reacted residues and allowed to dry. The emission characteristics of these phosphors are carried out on compacted powders as well as screen-printed coupons, at room temperature. FIG. 5 shows excitation spectra of Mn and Li activated lanthanum aluminate phosphor of present invention. The emission at 515 nm was recorded at room temperature in VUV region after excitation with continuous Deuterium (D2) Lamp. Referring to FIG. 5, the excitation spectrum of Mn and Li activated lanthanum aluminate phosphors prepared from metal salts and alumina is recorded at room temperature with the help of D2 continuum lamp in the wavelength range 100 to 200 nm. The emission spectra of Mn and Li activated lanthanum aluminate phosphors prepared from metal salts are recorded at room temperature while exciting with custom-made VUV lamps (147 nm and 173 nm). FIG. 6 shows the spectral energy distribution of custom-made VUV lamps. These lamps are used to excite phosphors in conjunction with 147 and 173 nm band pass filters. FIG. 7 shows emission spectra of Mn and Li activated lanthanum aluminate phosphor of present invention and Mn activated zinc silicate phosphor excited at 147 nm. The emission was recorded at room temperature. Referring to FIG. 8, decay characteristics (after glow decay or persistence) of lanthanum aluminate phosphor activated with Li and different amounts of Mn recorded at room temperature while exciting with Xe lamp (147 nm) is shown. FIG. 9 represents the variation in intensity with the concentration of Mn and Li. It is observed that the emission intensity of these samples increases with increase of Mn and Li concentrations and then decreases after certain amount of activators due to concentration quenching. Referring to FIG. 10, degradation of the present phosphor along with other green emitting phosphor material (ZnSiO4:Mn), can be seen. When compared with the standard ZnSiO4:Mn phosphor, the degradation of Mn and Li activated lanthanum aluminate phosphor is low. FIG. 10 shows the degradation in intensity of Mn and Li activated lanthanum aluminate phosphors exposed to high energy VUV lamp. Preferably, the phosphor pastes are prepared by mixing the phosphor powders with a suitable vehicle contains a solvent (terpineol or butyl carbolite acetate (BCA)/butoxyethoxy ethyl acetate) and a binder (ethyl cellulose or polyvinyl butyral). The vehicle is premixed in a high speed vertical stirrer by adding require amounts of solvent and binder. The phosphor paste is rolled in a three-roller grinder until the paste become very soft. Pastes of different phosphor are screen printed on small circular glass coupons (1″ dia). After drying the glass plates with phosphor pastes at 120 to 140° C. is subjected to binder burn out process at 500° C. for 1 to 4 hours until all the organics are evaporated. The study of luminescent and life characteristics of these phosphor materials are carried out on the glass coupons. Degradation of these with exposure of UVU radiation is calculated by measuring the intensity before and after exposing the phosphor screens to high energy Xe flash lamp in N2 atmosphere or Xe lamp in vacuum for different durations of time. It is found that the degradation of the present phosphor is minimal when compared to other PDP green emitting phosphors. After preliminary studies in the laboratory, suitable phosphor pastes are screen printed on back plate (42″). After binder-burn out (500° C.), the back plate with phosphor is frit sealed with front plate and filled with Xe—Ne gas mixture as described above. After backing cycle with gas fill, the assembly (front and back plate) is connected to all required electronics. Luminescent properties such as brightness, intensity, spectral energy distribution, after glow decay, color coordinates, color temperature, etc., stability or life span and electrical characteristics, such as, capacitance, discharge leakage, discharge delay, variation in sustain voltage, and ramp voltage, are studied on these panels. The phosphor material of the present invention emits green light when excited by vacuum ultra violet light of wavelength in the range of 100 nm to 200 nm and, as such, is suitable for use in plasma display panels. Accordingly, the present invention provides an improved plasma display panel (PDP), having a front plate with electrodes, dielectric layer, a thin protecting layer (MgO), a back plate with electrodes, reflective layer, ribs, phosphors, and a plurality of discharge spaces formed between the front and back plates having phosphor layers, wherein the improvement comprises: a plasma display panel which includes a green emitting phosphor material comprising a composition represented by the formula: La2-x-yB22O36:Mnx.Ay wherein: A=Li, Na or K; B═Al or Al+Ga; and 0.01≦x≦0.1 and 0.01≦y≦0.1, which phosphor emits green light when excited by vacuum ultra violet light of wavelength in the range of 100 nm to 200 nm. Further details of this invention will be described with reference in some of the following examples. EXAMPLE I The preparation of Mn and Li activated lanthanum aluminate phosphor by a solid-state reaction is described in this example. First, 28 grams of gamma (80-95%)—alpha (5-20%) aluminum oxide (0.01 to 0.02 micron powder), 18 grams of lanthanum oxalate, 0.34 grams of manganese fluoride (11), 1 gram of lithium fluoride are mixed in a mortar and pestle and transferred to high grade alumina crucible. The crucible is covered with lid and calcined at 1200 to 1400° C. for 2 to 4 hours in a box furnace. Samples are re-fired in a forming gas (4.5% H2+95.5% N2) at 1100 to 1300° C. for 2 to 4 hours in a tube furnace. The sample is left in the furnace in presence of forming gas until it cools down to room temperature. After cooling, these fine phosphor powders are subjected to ultrasonic agitation in water. Ultrasonic treatment helps to break the clusters into individual particles. After washing with water, these powders are dried at 120° C. for 6 hours. Depending on the required amounts, this can be scaled up. The emission, color coordinates and persistence characteristics of the above phosphor recorded at room temperature while exciting with excitation sources (Xe lamp) are given in Table I. EXAMPLE II The preparation procedure is the same as in example I except 0.34 grams of manganese fluoride (II) is replaced by 0.42 grams of manganese carbonate. EXAMPLE III The preparation procedure is the same as in example I except 0.34 grams of manganese fluoride is replaced by 0.65 grams of manganese nitrate. EXAMPLE IV The preparation procedure is the same as in example I except 1 gram of lithium fluoride is replaced by 1.54 grams of sodium fluoride. EXAMPLE V The preparation procedure is the same as in example I except 1 gram of lithium fluoride is replaced by 2 grams of potassium fluoride. EXAMPLE VI The preparation of Mn and Li activated lanthanum aluminate phosphor in an acid catalyzer by a sol-gel process is described in this example. 28 grams of aluminum isopropoxide (AIP) is dissolved in 4 liters of hot water (95° C.) while stirring. 9 grams of lanthanum nitrate, 0.4 grams of lithium fluoride and 0.18 grams of manganese fluoride are added to AlP solution. When the solution reaches 110° C., 5 cc HNO3 (0.5 mol) is added drop wise and refluxed for 24 hours. A water condenser column is maintained at 20° C. throughout the reflux by use of a circulating chiller. After cooling the flask to room temperature, the solution (dilute gel) is transferred into a crystallizing dish (3 L capacity) and left in an open atmosphere. After 5 to 6 days, the solution becomes a gel. These transparent hard gels are left at 45 to 50° C. for 12 hours in a lab oven. The dried product appears like soft glass, called xerogel. After crushing the gel in a glass mortar and pestle, a fine powder is collected into a high-grade alumina crucible and fired at 300° C. for 2 hours (rate of heating is 2°/min.) and then subjected to high temperature heat cycles, cooling and washing as described in Example I. EXAMPLE VII The procedure is the same as in example VI except 28 grams of aluminum isopropoxide is replaced by 34 grams of aluminum s-butoxide. EXAMPLE VIII Synthesis of diluted gels from lanthanum nitrate, manganese salt and aluminum isopropoxide in an acid medium is the same as described in Example VI and VII. Gel solutions obtained are subjected to freeze drying under vacuum. A cold trap is introduced between the vacuum pump and vacuum jar with gel. Dried powder is collected after a few hours of freeze drying at the bottom of the flask. These powders are subjected to calcination, cooling, washing and measurements as described in Example I. EXAMPLE IX Synthesis of diluted gels from lanthanum nitrate, manganese salt and aluminum isopropoxide in an acid medium is the same as described in Example VI. These diluted gels are sprayed through a spray nozzle in a 4″ diameter glass tube, with a 12″ heating zone at 120 to 150° C. Fine particles can also be produced using an ultrasonic aerosol generator (nebulizer). After spraying about a liter of dilute gel, very fine powder is scraped from the walls of the tube. The powders are subjected to calcination, cooling washing and measurements as in Example I. EXAMPLE X The preparation procedure is the same as in example I except 28 grams of aluminum oxide is replaced by 26 grams of aluminum oxide and 3.7 grams of gallium oxide. Table I demonstrates that the phosphors formed by solid state reaction and sol-gel processes of the present invention, provide various particle size ranges, while also generally providing a higher level of brightness, low dielectric constant, longer life and shorter persistence. TABLE I Luminescence Characteristics and Morphology of Manganese and Alkali Metal Activated Lanthanum Aluminate Phosphors Method Relative Intensity Half Persistence Color Particle of (AU) at Excitation Width (10%) Coordinates Size Preparation 147 nm 173 nm nm (ms) x y (μm) Example-I 105 100 23.56 9.0 0.125 0.772 0.1-10 Example-II 104 98 23.26 9.0 0.125 0.772 0.1-10 Example-III 100 94 23.64 9.0 0.125 0.772 0.1-10 Example-IV 97 92 25.08 8.5 0.125 0.775 0.1-12 Example-V 89 87 24.88 8.5 0.128 0.775 0.2-12 Example-VI 75 73 25.22 9.0 0.125 0.778 0.05-5 Example-VII 74 71 24.86 9.0 0.125 0.773 0.05-5 Example-VIII 76 73 25.05 9.0 0.125 0.773 0.05-5 Example-IX 63 61 23.81 9.0 0.125 0.774 0.01-3 Standard P1 a 76 80 45.24 9.0 0.228 0.714 0.5-10 (ZnSiO4:Mn) a Standard P1 is available from Kasei Optonix Ltd., Japan. It should be understood that the foregoing description is only illustrative of the invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances that fall within the scope of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to the preparation and growth of small size particles Mn 2+ and alkali halide doped lanthanum aluminate phosphor by solid sate and sol-gel methods. More specifically, the present invention provides green emitting Mn 2+ and alkali halide doped lanthanum aluminate phosphor and process by thermally decomposing salts of lanthanum, manganese, alkali halide and alumina or sol-gel powders. 2. Description of the Related Art The plasma display panel (PDP) as a medium of large format (60+″) television (TV), particularly high definition TVs (HDTV's) is gaining attention over cathode ray tube (CRT) based TVs due to its' high performance and scalability. Although, CRT works with less power and having better picture quality, it has size limitation. Larger screens (CRT) of diagonal size more than 40 inches have larger depth and very heavy. Conversely, diagonal size of PDP is growing day by day, as there is no problem with depth and weight. The structure of a PDP, which is known in the art, is described in FIGS. 1 a and 1 b . FIGS. 1 a and 1 b represents the cross section of an AC PDP. The plasma display has of two large area glass substrates 11 , 16 . Front plate 11 is made with sustain electrode 12 and scanning electrode 13 , covered with thick dielectric layer 14 and a thin protection layer (MgO) 15 . Back plate 16 is made with address electrodes 17 , reflective layer 18 , barrier ribs 19 and red phosphor 20 R (Y,Gd)BO 3 :Eu 2+ , green phosphor 20 G ZnSiO 4 :Mn 2+ (P1) or the blend of ZnSiO 4 :Mn 2+ and Y,GdBO 3 :Tb 3+ , blue phosphor 20 B BaMgAl 10 O 17 :Eu 2+ coated by screen printing or ink jet process. Both the glass plates are frit sealed together and filed the space 21 with Xe, Ne gas mixture. When voltage isapplied, a discharge is developed in the space 21 producing Vacuum UV (147 and 173 nm). When phosphors 2 ORGB are excited by VUV photons, they emit respective visible radiations viewed through the transparent front plate as an image 22 . The luminous efficiency of a PDP depends upon various factors including materials such as phosphors, gas mixture, dielectric layer, reflective layer, black matrix, electrodes, cell dimension and shape, nature, size and shape of electrodes, address waveforms, operating voltages, etc. The performance and lifetime of a PDP is strongly related to the nature of phosphors and their resistance to energetic discharge ions, electrons, and solarization from VUV arising from Xe/Ne gas discharge. Compared to standard emissive display such as CRTs (5-6 Im/W), the efficiency of a PDP is low (1-2 Im/W). To improve the overall efficiency of PDPs, considerable developments related to materials, design, process and electronics are under way. Efforts are also being made to develop new phosphors as well as to improve existing phosphors. Due to vacuum UV specific wavelengths available from Xe discharge (147 nm and 173 nm), only a limited number of lamp phosphors are suitable for PDP applications. In addition to high luminous efficiency, PDP phosphors should have longer life or stability, required persistence, suitable color coordinates, color temperature, and color saturation. The main application of large area plasma displays will be HDTV and high information content presentation. HDTV and similar type of display devices should have phosphors with low dielectric constant, required decay time, high resolution and high brightness for high performance. Screens coated in a close rib structure or closed cell structure with small particles exhibit higher packing density and also need lesser binder content. Persistence value, which is defined as being 10% of the initial brightness, is another concern in selecting a phosphor, and should be between 4 and 9 ms, also. The three phosphors (red, green and blue) currently used in PDP's have different dielectric constants and particle morphology. Due to their physical nature, all of the three phosphors need different rheology of phosphor paste as well as different screening processes. In PDP applications these phosphors exhibit different electrical characteristics in a finished panel. This results in compromises in the performance of the display. HDTV and similar type of devices should have high resolution and higher brightness for better performance. This can be achieved only with thin phosphor screens formed with very small phosphor particles (1-5 microns) in a close rib structure particularly in the case of PDP's. Screens with small particles have a higher packing density and also require lower binder content. Manganese activated zinc silicate phosphor with or without terbium activated yttrium gadolinium borate is currently used in plasma display panels (PDP) as a green emitting component due to its availability and high quantum efficiency. The higher dielectric constant of zinc silicate phosphor is of particular concern as it charges more than its' blue and red counterparts and this results in a higher sustainer voltage. When compared with red and blue emitting phosphors, zinc silicate phosphor also exhibits longer persistence, lower dielectric constant, negative discharge and faster saturation with the VUV flux. Another suitable green candidate, Tb activated yttrium gadolinium borate, which shows lower color purity is described in U.S. Pat. No. 6,004,481. As a trade off, PDP industry is adopting the blend of P1 and Tb activated borate. Efforts are being made to develop new phosphors to satisfying all requirements and replace existing Mn activated zinc silicate phosphor or the blend of silicate and borate. Some other phosphor candidates based on alkali halide aluminates are being suggested in Phosphor Handbook. U.S. Pat. Nos. 4,085,351; 5,868,963; and 6,423,248 B1 disclose the application of manganese activated aluminate phosphor with either of calcium, strontium, barium, magnesium or zinc in a gaseous discharge light-emitting element. European Patent No. EP 0 908 502 A1 teaches the preparation of barium or strontium magnesium aluminate by firing respective oxides or carbonate in presence of flux (AlF 3 ) at 1450° C. for 48 hours (total time). International Patent Application No. WO 98/37165 describes a method of making oxygen containing phosphor powder, which includes alkaline earth aluminates by spray techniques. European Patent No. EP 1 359 205 A1 describes the method of preparation of various green emitting phosphors has La, Mg, Zn aluminates with Tb, Mn as activators. Other related aspects to such phosphors are described in U.S. Pat. Nos. 4,150,321; 5,989,455; and 6,222,312 B1; European Patent No. 0 697 453 A1; International Patent No. WO 98/37165 by Hampden-Smith Mark, et al.; and publications entitled (1) “Fluorescence in α-Al 2 O 3 -like materials of K, Ba, La activated with Eu 2+ and Mn 2+ ” by M. Tamatani, Jap. J. Applied Physics, Vol. 13, No.6, June 1974 pp950-956; (2) “The behavior of phosphors with aluminate host lattices” by J. L. Sommerdijk and A. L. N. Stevels, Philips Tech. Review Vol. 37, No. 9/10, 1977 pp 221-233; and (3) “Principal phosphor materials and their optical properties” by M. Tamatani in “Phosphor Handbook” edited by S. Shionoya and W. M. Yen, CRC Press (1999) pp. 153-176. | <SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, it is an object of the present invention to provide a phosphor and method of preparation of manganese activated and alkali halide lanthanum aluminate phosphor having the empirical formula: in-line-formulae description="In-line Formulae" end="lead"? La 2-x-y B 22 O 36 :Mn x .A y in-line-formulae description="In-line Formulae" end="tail"? wherein: A=Li, Na or K; B═Al or Al+Ga; and 0.01≦x≦0.1 and 0.01≦y≦0.1. The phosphor is prepared by thermally decomposing the powder obtained by method including the steps of: mixing a source of alkali, such as, an alkali metal salt, a source of manganese, a source of lanthanum and a source of aluminum; reacting a dilute solution comprising a source of alkali halides, a source of lanthanum, a source of manganese and an organic precursor providing a source of aluminum, in an acid medium to form a dilute gel (sol-gel process); and converting the dilute gel into a xerogel powder (room temperature drying); converting the dilute gel into an aerogel powder (vacuum drying); or converting the dilute gel into a gel powder (spray drying), at specified temperatures, having a band emission in green region, peaking at 515-516 nm when excited by 147 and 173 nm radiation from Xenon gas mixture. The present invention also provides comparative performance data on the lanthanum aluminate phosphors that are activated with manganese (Mn 2+ ) and alkali halide such as lithium (Li + ) synthesized by two different processes: conventional solid-state reaction process (0.1 to 10 microns) and sol-gel process (0.01 to 5 microns). Phosphor materials are extremely sensitive to impurities, even at ppb levels. The low-temperature process minimizes the potential for cross contamination. Some of the unwanted impurities left in the materials from high temperature calcination may pose a threat to the performance of a phosphor. As the size of the phosphor particle decreases, the probability of electron and hole capture to the impurity increases and the e-h localization enhances the recombination rate via the impurity. The optimum impurity concentration (activator) level can be further increased with small particle size. This can be achieved by starting with sub micron size starting chemicals or sol gel process. The green phosphor of the present invention is capable of absorbing the photons of vacuum ultra violet light and converting them into photons of visible light. Accordingly, the green phosphor described herein is suitable to use in lamps and displays. | 20040302 | 20060411 | 20050908 | 95539.0 | 0 | KOSLOW, CAROL M | GREEN EMITTING PHOSPHOR MATERIAL AND PLASMA DISPLAY PANEL USING THE SAME | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,791,048 | ACCEPTED | Local control of underfill flow on high density packages, packages and systems made therewith, and methods of making same | An article includes a mounting substrate, a passive component site on the mounting substrate, and an active component site on the mounting substrate. The article also includes a fluid flow barrier disposed local to the passive component site and spaced apart from the active component site. The fluid flow barrier can be a recess that resists fluid flow thereinto because of surface tension of the fluid when it meets the recess edge. The fluid flow barrier can include a boundary that diverts fluid flow due to the angle of the recess edge as the fluid approaches it. An embodiment also includes a packaging system that includes the article and at least one passive component. An embodiment also includes a method of assembling the article or the packaging system. | 1. An article comprising: a mounting substrate; a passive component site on the mounting substrate; an active component site on the mounting substrate; and a fluid flow barrier disposed local to the passive component site and spaced apart from the active component site. 2. The article of claim 1, the mounting substrate including a first side and a second side, wherein the passive component site and the active component site are disposed in a solder mask on the first side, and wherein the fluid flow barrier is integral with the solder mask. 3. The article of claim 1, wherein the fluid flow barrier includes a sidewall and a floor, wherein the floor includes an electrically conductive material. 4. The article of claim 1, the mounting substrate including a first side and a second side, wherein the passive component site and the active component site are disposed in a solder mask on the first side, wherein the fluid flow barrier is a trench in the solder mask, and wherein the trench describes a perimeter around the passive component site. 5. The article of claim 1, the mounting substrate including a first side and a second side, wherein the passive component site and the active component site are disposed in a solder mask on the first side, wherein the fluid flow barrier is a trench in the solder mask, wherein the trench describes a perimeter around the passive component site, wherein the perimeter includes a trench side that is adjacent and spaced apart from the active component site, and wherein the trench side that is adjacent and spaced apart from the active component site includes a non-linear boundary. 6. The article of claim 1, the mounting substrate including a first side and a second side, wherein the passive component site and the active component site are disposed in a solder mask on the first side, wherein the fluid flow barrier is a trench in the solder mask, wherein the trench describes a perimeter around the passive component site, wherein the perimeter includes a trench side that is adjacent and spaced apart from the active component site, wherein the trench side that is adjacent and spaced apart from the active component site includes a non-linear boundary, and wherein the non-linear boundary is selected from curvilinear, rectilinear, and combinations thereof. 7. The article of claim 1, wherein the passive component site is spaced apart a distance from the active component site in a range from about 5 mm to about 1 mm. 8. The article of claim 1, wherein the passive component site is spaced apart a distance from the active component site by about 1.7 mm. 9. The article of claim 1, further including at least one fluid flow barrier that is disposed general to the active component site. 10. The article of claim 1, wherein the at least one fluid flow barrier includes a trench with a dielectric floor. 11. A packaging system comprising: a mounting substrate; a first passive component site on the mounting substrate; a first active component site on the mounting substrate; a fluid flow barrier disposed local to the passive component site and spaced apart from the active component site; a first active component disposed at the first active component site; a first passive component disposed at the passive component site; and an encapsulation material disposed contiguous the active component and extending away therefrom. 12. The packaging system of claim 11, wherein the first active component is selected from a processor, a data storage device, a digital signal processor, a micro controller, an application specific integrated circuit, and a microprocessor. 13. The packaging system of claim 11, wherein the first passive component is one of a plurality of passive components, and wherein each of the plurality of passive components is disposed spaced apart from the first active component in a distance range from about 1 mm to about 5 mm. 14. The packaging system of claim 11, further including at least one of an input device and an output device. 15. The packaging system of claim 11, further including at least one of an input device and an output device, and wherein the computing system is disposed in one of a computer, a wireless communicator, a hand-held device, an automobile, a locomotive, an aircraft, a watercraft, and a spacecraft. 16. The packaging system of claim 11, wherein the encapsulation material terminates in a convex meniscus profile at the fluid flow barrier. 17. The packaging system of claim 11, wherein the fluid flow barrier includes a sidewall and a floor, wherein the floor includes an electrically conductive material. 18. The packaging system of claim 11, the mounting substrate including first side and a second side, wherein the passive component site and the active component site are disposed in a solder mask on the first side, wherein the fluid flow barrier is a trench in the solder mask, and wherein the trench describes a perimeter around the passive component site. 19. The packaging system of claim 11, the mounting substrate including first side and a second side, wherein the passive component site and the active component site are disposed in a solder mask on the first side, wherein the fluid flow barrier is a trench in the solder mask, wherein the trench describes a perimeter around the passive component site, wherein the perimeter includes a trench side that is adjacent and spaced apart from the active component site, and wherein the trench side that is adjacent and spaced apart from the active component site includes a non-linear boundary. 20. The packaging system of claim 11, the mounting substrate including first side and a second side, wherein the passive component site and the active component site are disposed in a solder mask on the first side, wherein the fluid flow barrier is a trench in the solder mask, wherein the trench describes a perimeter around the passive component site, wherein the perimeter includes a trench side that is adjacent and spaced apart from the active component site, wherein the trench side that is adjacent and spaced apart from the active component site includes a non-linear boundary, and wherein the non-linear boundary is selected from curvilinear, rectilinear, and combinations thereof. 21. A method comprising: forming an active component site and a passive component site in a substrate, wherein the active component site and the passive component site are spaced apart; and forming a fluid flow barrier local to the passive component site and spaced apart from the active component site. 22. The method of claim 21, further including: installing an active component at the active component site; installing a passive component at the passive component site; and forming an encapsulation structure contiguous the active component and extending away therefrom. 23. The method of claim 21, wherein forming an encapsulation structure includes flowing encapsulation material under conditions that cause the encapsulation material to terminate at the fluid flow barrier. 24. The method of claim 21, wherein forming an encapsulation structure includes flowing encapsulation material under conditions that cause the encapsulation material to terminate in a convex meniscus profile at the fluid flow barrier. 25. The method of claim 21, wherein forming a fluid flow barrier local to the passive component site includes forming the fluid flow barrier perimeter to divert flow of the encapsulation material. 26. The method of claim 21, wherein forming an encapsulation structure includes flowing encapsulation material under conditions that cause the encapsulation material to terminate in a convex meniscus profile at the fluid flow barrier, and wherein forming a fluid flow barrier local to the passive component site includes forming the fluid flow barrier perimeter to divert flow of the encapsulation material. 27. The method of claim 21, wherein the passive component site and the active component site are disposed in a solder mask on the first side, wherein the fluid flow barrier is a trench in the solder mask, wherein the trench describes a perimeter around the passive component site, wherein the perimeter includes a trench side that is adjacent and spaced apart from the active component site, wherein the trench side that is adjacent and spaced apart from the active component site includes a boundary and wherein forming an encapsulation structure includes flowing encapsulation material under conditions that cause the encapsulation material to terminate at the fluid flow barrier. 28. The method of claim 21, wherein the passive component site and the active component site are disposed in a solder mask on the first side, wherein the fluid flow barrier is a trench in the solder mask, wherein the trench describes a perimeter around the passive component site, wherein the perimeter includes a trench side that is adjacent and spaced apart from the active component site, wherein the trench side that is adjacent and spaced apart from the active component site includes a non-linear boundary, and wherein the non-linear boundary is selected from curvilinear, rectilinear, and combinations thereof, and wherein forming an encapsulation structure includes flowing encapsulation material under conditions that cause the encapsulation material to terminate at the fluid flow barrier, and wherein forming a fluid flow barrier local to the passive component site includes forming the fluid flow barrier perimeter to divert flow of the encapsulation material. | TECHNICAL FIELD Embodiments relate to a packaged semiconductive die with integrated circuitry. More particularly, an embodiment relates to an underfill material flow barrier that is local to a passive component. BACKGROUND INFORMATION The thermal stability of packaging compositions such as underfill materials or other organic encapsulation molding compounds, is important in reducing the warpage of chip packages. Desirable materials have properties such as high thermal stability, low shrinkage, a favorable coefficient of thermal expansion (CTE), and other qualities such as a low moisture uptake. In chip packaging technology, the die is often bond-strengthened to the mounting substrate with an organic material that is flowed into contact with the die and the mounting substrate. In flip-chip processing, the organic material flows between the die active surface and the mounting substrate, thus strengthening the bond therebetween, while protecting the electrical contacts. Some of the organic material invariably flows beyond the footprint of the die and onto the mounting substrate at the margins of the die. The extent of this organic material flow, restricts the proximity of electrical contacts for passive components that are to be placed near the die, because the organic material can foul their contacts. BRIEF DESCRIPTION OF THE DRAWINGS In order to understand the manner in which embodiments are obtained, a more particular description of various embodiments briefly described above will be rendered by reference to the appended drawings. Understanding that these drawings depict only typical embodiments that are not necessarily drawn to scale and are not therefore to be considered to be limiting in scope, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: FIG. 1 is a cross-section of a package that includes a fluid flow barrier on a microstrip mounting substrate according to an embodiment; FIG. 2 is a selective plan view of the microstrip mounting substrate depicted in FIG. 1 according to an embodiment; FIG. 3 is a cross-section of a package that includes a fluid flow barrier on a stripline mounting substrate according to an embodiment; FIG. 4 is a plan of a passive component site detail taken from FIG. 3 according to an embodiment; FIG. 5 is a plan of a passive component site according to an embodiment; FIG. 6 is a plan of a passive component site according to an embodiment; FIG. 7 is a plan of a mounting substrate that includes an active component site and a plurality of passive component sites according to an embodiment; FIG. 8 is a plan of a mounting substrate that includes an active component site and a plurality of passive component sites according to an embodiment; FIG. 9 is a perspective cut-away of a computing system that includes the packaging composition according to an embodiment; and FIG. 10 is a process flow diagram that depicts a packaging process embodiment. DETAILED DESCRIPTION The following description includes terms, such as “upper”, “lower”, “first”, “second”, etc. that are used for descriptive purposes only and are not to be construed as limiting. The embodiments of a device or article described herein can be manufactured, used, or shipped in a number of positions and orientations. The terms “die” and “processor” generally refer to the physical object that is the basic workpiece that is transformed by various process operations into the desired integrated circuit device. A die is usually singulated from a wafer, and wafers may be made of semiconducting, non-semiconducting, or combinations of semiconducting and non-semiconducting materials. The term “chip” as used herein refers to a die that has been encapsulated in an organic, an inorganic, or a combination organic and inorganic housing. A “board” is typically a resin-impregnated fiberglass structure that acts as a mounting substrate for the chip. FIG. 1 is a cross-section of a package 100 that includes a fluid flow barrier on a microstrip mounting substrate according to an embodiment. A mounting substrate 110 for a microstrip board includes a solder mask 112 that covers an electrical layer 114. In an embodiment, the electrical layer 114 includes a copper layer that has been patterned to include an active component bond pad 116. The electrical layer 114 can also include a passive component bond pad 118. The electrical layer 114 can also include exposed conductive material that acts as a floor 120 in a fluid flow barrier according to an embodiment. Additionally, the electrical layer 114 can include traces 122, one of which is indicated in FIG. 1. In an embodiment for a chip package, an active component 124, such as a processor or a memory chip, is bonded to the active component bond pad 116 through a bump 126 according to an embodiment. The bump 126 is depicted as a solder ball, but other electrical connections can be used according to the specific application. Other electrical connections include bond wires bonded to the active component bond pad 116, lead fingers, pins, and others. According to an embodiment, a fluid flow barrier 132 is coupled to the active component 124 by virtue of its physical disposition in relation thereto. In an embodiment for a chip package, a passive component 128, such as a capacitor, an inductor, a resistor, or another passive component, is bonded to the passive component bond pad 118 through a bump 130 according to an embodiment. The bump 130 is depicted as a lead finger, but other electrical connections can be used according to the specific application. Other electrical connections include bond wires bonded to the passive component bond pad 118, solder balls, pins, and others. Similarly, according to an embodiment, the fluid flow barrier 132 is coupled to the passive component 128 by virtue of its physical disposition in relation thereto. FIG. I also depicts a fluid flow barrier 132, depicted in FIG. 1 as a recess 132 in the solder mask 112. The fluid flow barrier 132 can also be a dam according to an embodiment. The fluid flow barrier 132 can also be a recess in dam according to an embodiment. In any event, the fluid flow barrier 132 is disposed local to the passive component 128, and consequently local to the passive component site as set forth in this disclosure. The floor 120 can be the dielectric of the mounting substrate 110, however, if no electrical layer 114 is present in the recess 132. FIG. 1 also depicts an underfill material 134 that is illustrated as having filled the space between the active component 124 and the mounting substrate 110 to insulate and protect the bump 126. FIG. 1 also depicts incidental flow of the underfill material 134 beyond the margins of the active component 124, across the solder mask 112, and stopping at or near the edge of the fluid flow barrier 132. By “underfill material”, it is understood that an encapsulation material such as a polymer is used. The application of a flowable encapsulation material is not intended to be restricted to the underfill process. It is applicable to any process of applying an encapsulation material to a microelectronic device as it is being packaged with a local fluid flow barrier according to the various embodiments set forth in this disclosure. In FIG. 1, the underfill material 134 is depicted as having formed a convex meniscus 136 at the lip that is formed in the solder mask 112 by the recess 132 that is the fluid flow barrier 132 embodiment depicted in FIG. 1. In an embodiment, surface tension in the underfill material 134 is such that as it encounters the fluid flow barrier 132, significant resistance to further flow occurs at the edge of the recess 132, sufficient for enough time for the underfill material 134 to cease flowing. Consequent to this embodiment, the fluid flow barrier 132 is integral with the solder mask 112. FIG. 1 also depicts a raised portion 138 of the solder mask 112 that is between the fluid flow barrier 132 and the location of the passive component bond pad 118. Although the floor 120 of the recess 132 is depicted as including an exposed portion of the electrical layer 114, it is understood that patterning of the electrical layer 114 can include a dielectric floor of the recess with only the substrate 110 exposed as the floor thereof. FIG. 2 is a selective plan view of the microstrip mounting substrate depicted in FIG. 1 according to an embodiment. The section line 1-1 illustrates the view taken from FIG. 1. The mounting substrate 112 includes a passive component site 140 and an active component site 142. The active component site 142 is depicted as an organic land grid array (OLGA) that includes a plurality of active component bond pads 116, one of which is labeled. The passive component site 140 is depicted as an OLGA that includes a plurality of passive component bond pads 118, one of which is labeled. The passive component site 140 is also depicted as a perimeter 140 around a given plurality of passive component bond pads 118 for a single passive component. The raised portion 138 of the solder mask 112 also delineates a perimeter around the plurality of passive component bond pads 118 for a single passive component. Accordingly in an embodiment, the fluid flow barrier for a given passive component site 140 is disposed local only to that passive component site 140. FIG. 2 also depicts the spaced-apart distance between the perimeters of the passive component site 140 and the active component site 142. In an embodiment, the distance 144 between the perimeters of the passive component site 140 and the active component site 142 is in a range from about 5 millimeter (mm) to about 1 mm. In an embodiment, the distance 144 is in a range from about 1.5 mm to about 4 mm. In an embodiment, the distance 144 is in a range from about 2 mm to about 3 mm. In an embodiment, the distance 144 is about 1.7 mm. FIG. 3 is a cross-section of a package 300 that includes a fluid flow barrier on a stripline mounting substrate according to an embodiment. A mounting substrate 310 for a stripline board includes a substrate cover 311 that covers an electrical layer 314. In the stripline board, an electrical ground layer 315 is disposed above the electrical layer 314 and is exposed in selected sites with a solder mask 312. In an embodiment, the electrical layer 314 includes a copper layer that has been patterned to include an active component bond pad 316. The electrical layer 314 can also include a passive component bond pad 318. The electrical ground layer 315 can include exposed conductive material that acts as a floor 320 in a fluid flow barrier according to an embodiment. Additionally, the electrical layer 314 can include traces 322, one of which is indicated in FIG. 3. In an embodiment for a chip package, an active component 324, such as a processor or a memory chip, is bonded to the active component bond pad 316 through a bump 326 according to an embodiment. The bump 326 is depicted as a solder ball, but other electrical connections can be used according to the specific application. Other electrical connections include bond wires bonded to the active component bond pad 316, lead fingers, pins, and others. According to an embodiment, the fluid flow barrier 332 is coupled to the active component 324 by virtue of its physical disposition in relation thereto. The an embodiment for a chip package, a passive component 328, such as a capacitor, an inductor, a resistor, or another passive component, is bonded to the passive component bond pad 318 through a bump 330 according to an embodiment. The bump 330 is depicted as a lead finger, but other electrical connections can be used according to the specific application. Other electrical connections include bond wires bonded to the passive component bond pad 318, solder balls, pins, and others. Similarly, according to an embodiment, the fluid flow barrier 332 is coupled to the passive component 328 by virtue of its physical disposition in relation thereto. FIG. 3 also depicts the fluid flow barrier 332, depicted in FIG. 3 as a recess 332 in the solder mask 312. The fluid flow barrier 332 can also be a dam according to an embodiment. The fluid flow barrier 332 can also be a recess in dam according to an embodiment. In any event, the fluid flow barrier 332 is disposed local to the passive component 328, and consequently local to the passive component site as set forth in this disclosure. An example of the local disposition of the fluid flow barrier 332 is set forth in FIG. 2 as item 132 and elsewhere in this disclosure. FIG. 3 also depicts an underfill material 334 that is depicted as having filled the space between the active component 324 and the mounting substrate 310 to insulate and protect the bump 326. FIG. 3 also depicts incidental flow of the underfill material 334 beyond the margins of the active component 324, across the solder mask 312, and stopping at or near the edge of the fluid flow barrier 332. In FIG. 3, the underfill material 334 is depicted as having formed a convex meniscus 336 at the lip that is formed in the solder mask 312 by the recess 332 that is the fluid flow barrier 332 embodiment depicted in FIG. 3. In an embodiment, surface tension in the underfill material 334 is such that as it encounters the fluid flow barrier 332, significant resistance to further flow occurs at the edge of the recess 332, sufficient for enough time for the underfill material 334 to cease flowing. Consequent to this embodiment, the fluid flow barrier 332 is integral with the solder mask 312. FIG. 3 also depicts a raised portion 338 of the solder mask 312 that is between the fluid flow barrier 332 and the location of the passive component bond pad 318. Although the floor 320 of the recess 332 is depicted as including an exposed portion of the electrical ground layer 315, it is understood that patterning of the electrical ground layer 315 can include a floor of the recess 320 with only the substrate cover 311 exposed as the floor thereof. FIG. 4 is a plan of a passive component site 140 detail taken from FIG. 3, along the dashed line 4-4 according to an embodiment. The fluid flow barrier 132 is depicted at the perimeter with the floor 120 that in an embodiment is an exposed portion of the electrical layer 114. Consequently, the fluid flow barrier 132 is local to the passive component site 140. Additionally, the raised portion 138 of the solder mask 112 is depicted between the passive component bond pad 118 and the fluid flow barrier 132. FIG. 5 is a plan of a passive component site 540 according to an embodiment. The passive component site 540 is similar in locatability to the passive component site 140 depicted in FIGS. 2 and 4. A fluid flow barrier 532 is depicted at the perimeter with a floor 520 that in an embodiment is an exposed portion of an electrical layer such as the electrical layer 114 depicted in FIG. 1. Consequently, the fluid flow barrier 532 is local to the passive component site 540. In an embodiment, the floor 520 exposes a substrate (not pictured). In an embodiment, the floor 520 exposes an electrical ground layer. Additionally, a raised portion 538 of the solder mask 512 is depicted between a passive component bond pad 518 and the fluid flow barrier 532. FIG. 5 depicts a non-linear boundary 546 of the passive component site 540. The non-linear boundary 546 includes a boundary that is situated to divert flow of underfill material 534. Diversion of flow of underfill material 534 includes situating the non-linear boundary 546 such that a flow front 548 of underflow material 534 encounters the non-linear boundary 546 of the fluid flow barrier 532 at a non-orthogonal angle, as indicated by the directional arrows 550. In an embodiment, the non-linear boundary 546 is a composite of rectilinear segments 546. In an embodiment, the non-linear boundary 546 includes two surfaces that are set at an obtuse but interior angle with respect to each other. In an embodiment, the angle is about 179°. In an embodiment, the angle is in a range from about 179° to about 150°. In an embodiment, the angle is in a range from about 150° to about 120°. In an embodiment, the angle is in a range from about 120° to about 91°. In an embodiment, the angle is an acute angle. FIG. 6 is a plan of a passive component site 640 according to an embodiment. The passive component site 640 is similar in locatability to the passive component site 540 depicted in FIG. 5. A fluid flow barrier 632 is depicted at the perimeter with a floor 620 that in an embodiment is an exposed portion of an electrical layer such as the electrical layer 114 depicted in FIG. 1. Consequently, the fluid flow barrier 632 is local to the passive component site 640. In an embodiment, the floor 620 exposes a substrate (not pictured). In an embodiment, the floor 620 exposes an electrical ground layer. Additionally, a raised portion 638 of the solder mask 612 is depicted between a passive component bond pad 618 and the fluid flow barrier 632. FIG. 6 depicts a non-linear boundary of the passive component site 640. The non-linear boundary includes a boundary that is situated to divert flow of underfill material 634. Diversion of flow of underfill material 634 includes situating the non-linear boundary such that a flow front 648 of underflow material 634 encounters the non-linear boundary of the fluid flow barrier 632 at a non-orthogonal angle, as indicated by the directional arrows 650. In an embodiment, the non-linear boundary is a composite of rectilinear segments 646 and curvilinear segments 647. In an embodiment, the non-linear boundary includes two surfaces 646 that are set at an obtuse but interior angle with respect to each other. In an embodiment, the angle is about 179°. In an embodiment, the angle is in a range from about 179° to about 150°. In an embodiment, the angle is in a range from about 150° to about 120°. In an embodiment, the angle is in a range from about 120° to about 91°. FIG. 7 is a plan of a mounting substrate 700 that includes an active component site 742 and a plurality of passive component sites according to an embodiment. Of the passive components sites, one is depicted with reference number 740. The passive component site 740 includes a fluid flow barrier 732 that is local thereto. In an embodiment, the passive component site 740 is depicted with a non-linear boundary 746 that faces the active component site 742. Accordingly, the non-linear boundary 746 is situated to divert flow of underfill material by a non-orthogonal encounter of the underfill material with a non-linear boundary 746 as set forth in this disclosure. In an embodiment, the mounting substrate 700 includes a corner passive component site 752 that is substantially rectangular with no actual non-linear boundaries. The corner passive component site 752, however, has effective non-linear boundaries as flow of underfill material will encounter the two closest boundaries 746′ at a non-orthogonal flow angle relative thereto. FIG. 8 is a plan of a mounting substrate 800 that includes an active component site 842 and a plurality of passive component sites according to an embodiment. Of the passive components sites, one is depicted with reference number 840. The passive component site 840 includes a fluid flow barrier 832 that is local thereto. In an embodiment, the passive component site 840 is depicted with a non-linear boundary 846 that faces the active component site 842. Accordingly, the non-linear boundary 846 is situated to divert flow of underfill material by a non-orthogonal encounter of the underfill material with a non-linear boundary 846 as set forth in this disclosure. In an embodiment, the mounting substrate 800 includes a corner passive component site 852 that is substantially rectangular with no actual non-linear boundaries. The corner passive component site 852, however, has effective non-linear boundaries as flow of underfill material will encounter the two closest boundaries 846′ at a non-orthogonal flow angle relative thereto. The mounting substrate 800 also includes a fluid flow barrier 854 that controls flow of underfill material generally. In an embodiment, the fluid flow barrier 854 is a recess such as the fluid flow barrier 132 depicted in FIG. 1. The fluid flow barrier 854 can also be a dam according to an embodiment. The fluid flow barrier 854 can also be a recess in dam according to an embodiment. In any event, the fluid flow barrier 854 is disposed generally with respect to the passive component sites 840. FIG. 9 is a perspective cut-away of a computing system 900 that includes the local fluid flow barrier according to an embodiment. One or more of the foregoing embodiments of a structure that exhibits local control of underfill material during flow application may be utilized in a computing system, such as a computing system 900 of FIG. 9. The computing system 900 includes at least one processor (not pictured), which is enclosed in a package 910, a data storage system 912, at least one input device such as keyboard 914, and at least one output device such as monitor 916, for example. The computing system 900 includes a processor that processes data signals, and may include, for example, a microprocessor, available from Intel Corporation. In addition to the keyboard 914, the computing system 900 can include another user input device such as a mouse 918, for example. For purposes of this disclosure, a computing system 900 embodying components in accordance with the claimed subject matter may include any system that utilizes a microelectronic device system, which may include, for example, a local fluid flow barrier that is coupled to data storage such as dynamic random access memory (DRAM), polymer memory, flash memory, and phase-change memory. In this embodiment, the local fluid flow barrier is coupled to any combination of these functionalities by being coupled to a processor. In an embodiment, however, a local fluid flow barrier set forth in this disclosure is coupled to any of these functionalities. For an example embodiment, data storage includes an embedded DRAM cache on a die. Additionally in an embodiment, the local fluid flow barrier that is coupled to the processor (not pictured) is part of the system with a local fluid flow barrier that is coupled to the data storage of the DRAM cache. Additionally in an embodiment, a local fluid flow barrier is coupled to the data storage 912. In an embodiment, the computing system can also include a die that contains a digital signal processor (DSP), a micro controller, an application specific integrated circuit (ASIC), or a microprocessor. In this embodiment, the local fluid flow barrier is coupled to any combination of these functionalities by being coupled to a processor. For an example embodiment, a DSP (not pictured) is part of a chipset that may include a stand-alone processor (in package 910) and the DSP as separate parts of the chipset. In this embodiment, a local fluid flow barrier is coupled to the DSP, and a separate local fluid flow barrier may be present that is coupled to the processor in package 910. Additionally in an embodiment, a local fluid flow barrier is coupled to a DSP that is mounted on the same board as the package 910. It can now be appreciated that embodiments set forth in this disclosure can be applied to devices and apparatuses other than a traditional computer. For example, a die can be packaged with an embodiment of the local fluid flow barrier, and placed in a portable device such as a wireless communicator or a hand-held device such as a personal data assistant and the like. Another example is a die that can be packaged with an embodiment of the local fluid flow barrier and placed in a vehicle such as an automobile, a locomotive, a watercraft, an aircraft, or a spacecraft. FIG. 10 is a method flow diagram that depicts a packaging method 1000 according to an embodiment. The method flow includes forming a mounting substrate. The method flow can also include assembling a chip package. At 1010, the method includes forming an active component site and a passive component site in a substrate. In a non-limiting example, the method includes patterning an electrical layer 114 in a microstrip board 100 as depicted in FIG. 1. At 1020, the method includes forming a fluid flow barrier that is local to the passive component site. In a non-limiting example, the method includes patterning the solder mask 112 that covers the electrical layer 114 as depicted in FIG. 1. At 1030, the method includes assembling an active component at the active component site and a passive component at the passive component site. In a non-limiting example, the method includes assembling the passive component 128 and the active component 124 to the mounting substrate 110 with the recess 132 therebetween. At 1040, the method includes underfilling the active component with underfill material, under conditions that cause the underfill material to stop at or before the fluid flow barrier that is local to the passive component site. In a non-limiting example, the method includes flowing encapsulation material under conditions that cause the underfill material to terminate at or before it encounters the local fluid flow barrier. It is emphasized that the Abstract is provided to comply with 37 C.F.R. § 1.72(b) requiring an Abstract that will allow the reader to quickly ascertain the nature and gist of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In the foregoing Detailed Description, various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments of the invention require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description of Embodiments of the Invention, with each claim standing on its own as a separate preferred embodiment. It will be readily understood to those skilled in the art that various other changes in the details, material, and arrangements of the parts and method stages which have been described and illustrated in order to explain the nature of various embodiments of this invention may be made without departing from the principles and scope thereof as expressed in the subjoined claims. | <SOH> BACKGROUND INFORMATION <EOH>The thermal stability of packaging compositions such as underfill materials or other organic encapsulation molding compounds, is important in reducing the warpage of chip packages. Desirable materials have properties such as high thermal stability, low shrinkage, a favorable coefficient of thermal expansion (CTE), and other qualities such as a low moisture uptake. In chip packaging technology, the die is often bond-strengthened to the mounting substrate with an organic material that is flowed into contact with the die and the mounting substrate. In flip-chip processing, the organic material flows between the die active surface and the mounting substrate, thus strengthening the bond therebetween, while protecting the electrical contacts. Some of the organic material invariably flows beyond the footprint of the die and onto the mounting substrate at the margins of the die. The extent of this organic material flow, restricts the proximity of electrical contacts for passive components that are to be placed near the die, because the organic material can foul their contacts. | <SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>In order to understand the manner in which embodiments are obtained, a more particular description of various embodiments briefly described above will be rendered by reference to the appended drawings. Understanding that these drawings depict only typical embodiments that are not necessarily drawn to scale and are not therefore to be considered to be limiting in scope, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: FIG. 1 is a cross-section of a package that includes a fluid flow barrier on a microstrip mounting substrate according to an embodiment; FIG. 2 is a selective plan view of the microstrip mounting substrate depicted in FIG. 1 according to an embodiment; FIG. 3 is a cross-section of a package that includes a fluid flow barrier on a stripline mounting substrate according to an embodiment; FIG. 4 is a plan of a passive component site detail taken from FIG. 3 according to an embodiment; FIG. 5 is a plan of a passive component site according to an embodiment; FIG. 6 is a plan of a passive component site according to an embodiment; FIG. 7 is a plan of a mounting substrate that includes an active component site and a plurality of passive component sites according to an embodiment; FIG. 8 is a plan of a mounting substrate that includes an active component site and a plurality of passive component sites according to an embodiment; FIG. 9 is a perspective cut-away of a computing system that includes the packaging composition according to an embodiment; and FIG. 10 is a process flow diagram that depicts a packaging process embodiment. detailed-description description="Detailed Description" end="lead"? | 20040302 | 20080415 | 20050908 | 63701.0 | 0 | SEMENENKO, YURIY | LOCAL CONTROL OF UNDERFILL FLOW ON HIGH DENSITY PACKAGES, PACKAGES AND SYSTEMS MADE THEREWITH, AND METHODS OF MAKING SAME | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,791,182 | ACCEPTED | PRESSURE TANK VALVE SOCKET | Embodiments of a pressure tank valve socket are disclosed which may be used to safely remove the valve from a propane or other pressure tank without damaging the valve. The pressure tank valve socket applies force only to the sturdiest part of the valve and, thus, prevents injury to the more delicate parts of the valve. | 1. A pressure tank valve socket to remove or attach the valve on a pressure tank where the pressure tank has a valve receptor and the valve has a threaded connector for affixing the valve to the valve receptor and the valve includes a pair of opposed shoulders which are planar surfaces parallel to each other and to the longitudinal axis of said valve receptor comprising: (1) a hollow socket configured such that it is capable of fitting over the body of the valve and having a closed end and an open end; (2) the open end of the hollow socket having a pair of opposed bearing surfaces which are parallel to each other and capable of fitting over and engaging the shoulder of said valve; and (3) turning engagement means affixed to the outer surface of said hollow socket opposite the opposed bearing surfaces such that turning means may be engaged with the turning engagement means to turn said hollow socket in either direction; whereby the pressure tank valve socket has said hollow socket which may be placed over the body of said valve on a pressure tank, said opposed bearing surfaces on said hollow socket may engage the opposed shoulders of said valve, and turning means such as a wrench may be engaged with said turning engagement means to remove or attach said valve from or to said pressure tank. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to tanks holding pressurized gasses such as propane and more specifically to tool for removing valves from such tanks. 2. Background Information All around the United States and throughout the world, hundreds of thousands of people use compressed gas stored in metal, usually steel, tanks. Perhaps the most common of these uses is the use of “bottled” propane in familiar steel tanks. Propane is used for a variety of purposes including barbecue grills, powering forklifts, and as a heating and cooking fuel for recreational vehicles. Although propane tanks are referenced in the following descriptions, the pressure tank valve socket of the instant invention could be easily adapted for use with a variety of pressure tank types. In the United States and in many other countries, the construction of propane tanks and valves and the filling of such tanks is highly regulated. One consequence of such regulations is that the valve on a propane tank is usually protected by a metal guard which surrounds much of the valve. In most cases, such valves are threaded and screw into a receptor on the tank. In addition, most valves are manufactured of a relatively soft metal such as brass to insure that all threaded fastenings fit tightly. Periodically propane tank valves must be removed for repair or replacement. Because of the guard which surrounds the valve and because the valve is made of soft material; it is very difficult, if not impossible, to get a conventional wrench into a position in which it may be used to remove the valve without causing damage to the valve. The invention presented in the present application is believed to solve, in a simple and effective fashion, problems which have long plagued persons attempting to remove a valve from any of a variety of compressed gas tanks such as propane tanks: a inexpensive and effective tool for easily removing the valve from such a tank without damaging the valve. The ideal pressure tank valve socket should provide a tool for easily and efficiently removing (or attaching) a valve from a pressurized gas tank. The ideal pressure tank valve socket should also be configured to avoid damage to the valve of such a tank. The ideal pressure tank valve socket should also be simple, inexpensive, rugged, and easy to use. SUMMARY OF THE INVENTION The pressure tank valve socket of the instant invention is a tool for easily and safely removing the valve from a receptor on a propane tank without damaging the valve. The valve typically has a rotating control handle to control the flow of gas through the valve and a threaded male end or connector which screws into the receptor on the tank. Typically, a safety valve (in many cases referred to as an overfill protection device or OPD) protrudes at a right angle from the axis between the handle and the connector and a regulator connector protrudes from the valve opposite and a bit above the safety valve. Although there is some small variation in valves, the valves have parallel, opposed shoulders on either side of the valve between the safety valve and the regulator connector. In some cases, the handle may be removed and in some cases the handle is fixed. Some propane tanks, such as those used for recreational vehicles, have removable handles and an external regulator connector. The pressure tank valve socket of the instant invention is essentially a large socket which works on the same principle as the well known socket and handle arrangement. The unique and original features of the pressure tank valve socket involve a configuration which allows the socket to fit over the handle (if the particular valve has a fixed handle), the safety valve, and the regulator connector without bearing upon any of those elements. The pressure tank valve socket is configured such that the socket bears upon only the two shoulders found in the valve. These shoulder elements are the most sound elements of the valve, and the most capable of handling the turning pressure necessary to remove or attach the valve. The pressure tank valve socket of the instant invention fits over the valve inside the guard and engages the shoulder elements. The free end of the pressure tank valve socket includes a hex head stud which may be engaged by a conventional socket set handle, a conventional wrench, or similar device and used to remove or attach the valve from or to the propane tank. Because only the shoulders are engaged, the relatively fragile safety valve and regulator connector are never damaged when removing or attaching a valve. The pressure tank valve socket has three basic embodiments. One is used for a barbecue type tank with a fixed handle; one is used for the type of tank which is used, for instance, to power a forklift and which has a removable handle; the third type is used, for instance, in a recreational vehicle and has an external regulator connector. One of the major objects of the pressure tank valve socket of the present invention is to provide a tool for easily and efficiently removing (or attaching) a valve from a pressure tank. Another objective of the present invention is to be configured to avoid damage to the pressure tank valve. Another objective of the present invention is to provide a pressure tank valve socket which is simple, inexpensive, and easy to use. These and other features of the invention will become apparent when taken in consideration with the following detailed description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a typical propane tank valve, FIG. 2 is a top view of a typical propane tank valve attached to a typical propane tank, FIG. 3 is a side view of an embodiment of the pressure tank valve socket of the instant invention for use with valves having fixed handles, FIG. 4 is a front view of an embodiment of the pressure tank valve socket of the instant invention for use with valves having fixed handles, FIG. 5 is a side view of an embodiment of the pressure tank valve socket of the instant invention for use with valves having removable handles and external regulator connectors, FIG. 6 is a front view of an embodiment of the pressure tank valve socket of the instant invention for use with valves having removable handles and external regulator connectors, FIG. 7 is a side view of an embodiment of the pressure tank valve socket of the instant invention for use with valves having removable handles, FIG. 8 is a front view of an embodiment of the pressure tank valve socket of the instant invention for use with valves having removable handles, FIG. 9 is a sectional view of an embodiment of the pressure tank valve socket of the instant invention for use with valves having removable handles and external regulator connectors taken along line 9-9 of FIG. 5, and FIG. 10 is a sectional view of an embodiment of the pressure tank valve socket of the instant invention for use with valves having removable handles taken along line 10-10 of FIG. 7. DESCRIPTION OF A PREFERRED EMBODIMENT Referring to the drawings, FIGS. 1 through 10, there are shown three preferred forms of the pressure tank valve socket embodying the present invention. FIGS. 1 and 2 show a typical valve and propane tank. FIGS. 3 and 4 show an embodiment of the instant invention for use with valves having fixed handles; FIGS. 5 and 6 show an embodiment of the instant invention for use with valves having removable handles and external regulator connectors which are typically used with recreational vehicles; FIGS. 7 and 8 show an embodiment of the instant invention for use with valves having removable handles which are typically found in implements such as fork lifts; FIG. 9 is a sectional view of the socket shown in FIG. 5, and FIG. 10 is a sectional view of the socket shown in FIG. 7. Now referring to FIG. 1, a typical propane valve is shown. For purposes of this application, the configuration of a common, barbecue grill, type propane tank and valve will be used for illustration. Again, although propane tanks are referenced in this description, the pressure tank valve socket of the instant invention could be used with a variety of pressure tank valves. In this configuration, the valve sits upright and is attached to the top of the propane tank. The valve has a handle 2, which is used to turn on or shut off the flow of propane through the valve. On the bottom of the valve, opposite the handle, is a connector 4, which is threaded and may be attached to the propane tank by turning the threads within complementary threads in a receptor on the top of the tank. Propane valves typically have a safety valve 6 which protrudes outward from the valve body at a right angle to the axis between the handle 2 and the connector 4 and which is much closer to said connector 4 than to said handle 2. The safety valve 6 has a diameter which is smaller than the diameter of said connector 4. A regulator connector 8 protrudes from the valve body at 180 degrees from said safety valve 6 and is between said safety valve 6 and said handle 2. The diameter of the regulator connector 8 is larger than the diameter of said connector 4. A shoulder 10 protrudes from the valve body perpendicular to said safety valve 6 and said regulator connector 8 and is approximately aligned with said safety valve 6. There is a second shoulder 10 (not shown) opposite said shoulder 10 which is shown. Said shoulders 10 are parallel, planar surfaces which are also parallel to the longitudinal axis of said connector 4 and are, typically, aligned with the longitudinal axis. Now referring to FIG. 2, a top view of a typical valve and propane tank is shown. In this figure said handle 2 has been removed for clarity; but, in a very common configuration, the handle is not removable. The tank 14 is typically cylindrical with a rounded top and bottom. The valve is connected to the tank by threading said connector 4 into complimentary threads on the top of the tank 14. Said tank 14 includes a cylindrical guard 16 which protrudes upward from the top of the tank and encloses said valve except for and opening 18 which allows access to said regulator connector 8. For purposes of this description, said regulator connector 8 is considered rearward and said safety valve 6 is considered forward. Now referring to FIG. 3, a side view of an embodiment of the pressure tank valve socket of the instant invention is shown. This embodiment is used to remove a propane tank valve of the type which has a fixed handle. The typical valve is shown, in this figure, with phantom lines. The pressure tank valve socket includes a socket 20 having a rectangular cross section. A hex head 22 having a hexagonal shape protrudes from the top of the socket 20 and may be engaged with a conventional wrench or socket set handle. Said socket 20 is enclosed in forward and open in the rear. The upper portion of said socket 20 is hollow with a rectangular cross section and large enough to accommodate said handle 2. The bottom of said socket 20 is also hollowed out, but in a rectangular cross section having a width slightly larger than the distance between the outer surfaces of said shoulders 10 such that it fits over, but engages said shoulders 10. This rectangular hollowed out section is of sufficient length to accommodate said safety valve 6. Now referring to FIG. 4, a front view of the embodiment of the pressure tank valve socket shown in FIG. 3 is shown. The inner surfaces of the rectangular hollowed out section of said socket 20 form opposing bearing surfaces 30 which engage the outer surfaces of said shoulders 10. The top of said handle 2 (not shown) engages the top inner surface of said socket 20 and hold it in place. A conventional wrench, socket set handle, or other means may be used to engage the hex head 22 and twist the valve onto or away from said tank 14. Because neither said safety valve 6 nor said regulator connector 8 are engaged by said socket 20, those relatively fragile parts are protected and can not be damaged during valve removal or attachment. Said hex head 22 is aligned with and opposite to the bearing surfaces 30. Now referring to FIG. 5, a side view of an embodiment of the pressure tank valve socket of the instant invention is shown for use with valves which have a handle which may be removed and an external regulator connector. This embodiment also has said socket 20 and said hex head 22. In this embodiment said socket 20 is also hollow; but, because said handle 2 has been removed, this hollow does not need to be large enough to accommodate said handle 2. This embodiment includes three hollow sections, two having rectangular cross sections and one having a circular cross section. The topmost hollow 23 is the circular one and is configured to accommodate the handle fixture from which said handle 2 has been removed. Beneath the topmost hollow 23 is a first rectangular hollow 25 which is open to the rear and is just wide enough to engage said shoulders 10 (see FIG. 6) on the valve. A second rectangular hollow 27 is forward of the first rectangular hollow 25 and is wide enough to accommodate the safety valve 6 (not shown) of the valve. The configuration of these hollows may be better seen in FIG. 6. This pressure tank valve socket also has a hex head 22 protruding upward from its top surface and aligned with said connector 4 (not shown). Now referring to FIG. 6, a front view of an embodiment of the pressure tank valve socket of the instant invention the same as shown in FIG. 5 is shown. The bottom of said socket 20 is essentially open. The second rectangular hollow 27 encloses but does not engage said safety valve 8. Said first rectangular hollow 25 is wide enough to fit over and engage said shoulders 10 which is also wide enough to allow said regulator connector 8 (not shown) to fit through the opening in the rear of said first rectangular hollow 25. In operation, the pressure tank valve socket is placed over the valve with said first rectangular hollow 25 engaging said shoulders 10 and the top mounting fixture for said handle 2 contacting the top inner surface of said socket 20 for stability. Said socket 20 my then be turned using said hex head 22 to attach or remove the valve. Now referring to FIG. 7, a side view of an embodiment of the pressure tank valve socket of the instant invention is shown for use with valves which have a handle which may be removed is shown. Said hex head 22 and said socket 20 are very similar in this embodiment to the previously discussed two embodiments; however, the various hollows are configured to accommodate the different valve configuration. A fixture hollow 35 is circular in cross section and large enough to accommodate a handle fixture near the top of the inside of said socket 20. A bearing hollow 37 is below the fixture hollow 35 and is just wide enough to fit over and engage said shoulders 10 (see FIG. 8) on the valve. Now referring to FIG. 8, a front view of an embodiment of the pressure tank valve socket of the instant invention the same as in FIG. 7 is shown. Again, all of the parts of the valve are enclosed, but not engaged except for said shoulders 10. The bearing hollow 37 again encloses and engages said shoulders 10 and a wrench, socket set handle, or other means may be used to remove or attach the valve with said socket 20. Now referring to FIG. 9, a sectional view of the pressure tank valve socket of the embodiment shown in FIG. 5 is shown. This view shows the sizes and relative positions of said first rectangular hollow 25, said second rectangular hollow 27, and said topmost hollow 23. Now referring to FIG. 10, sectional view of the pressure tank valve socket of the embodiment shown in FIG. 7 is shown. This view shows the sizes and relative positions of said fixture hollow 35 and said bearing hollow 37. In all embodiments, the pressure tank valve socket of the instant invention is made from forged steel, but other materials having sufficient strength and rigidity could be used. While preferred embodiments of this invention have been shown and described above, it will be apparent to those skilled in the art that various modifications may be made in these embodiments without departing from the spirit of the present invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates generally to tanks holding pressurized gasses such as propane and more specifically to tool for removing valves from such tanks. 2. Background Information All around the United States and throughout the world, hundreds of thousands of people use compressed gas stored in metal, usually steel, tanks. Perhaps the most common of these uses is the use of “bottled” propane in familiar steel tanks. Propane is used for a variety of purposes including barbecue grills, powering forklifts, and as a heating and cooking fuel for recreational vehicles. Although propane tanks are referenced in the following descriptions, the pressure tank valve socket of the instant invention could be easily adapted for use with a variety of pressure tank types. In the United States and in many other countries, the construction of propane tanks and valves and the filling of such tanks is highly regulated. One consequence of such regulations is that the valve on a propane tank is usually protected by a metal guard which surrounds much of the valve. In most cases, such valves are threaded and screw into a receptor on the tank. In addition, most valves are manufactured of a relatively soft metal such as brass to insure that all threaded fastenings fit tightly. Periodically propane tank valves must be removed for repair or replacement. Because of the guard which surrounds the valve and because the valve is made of soft material; it is very difficult, if not impossible, to get a conventional wrench into a position in which it may be used to remove the valve without causing damage to the valve. The invention presented in the present application is believed to solve, in a simple and effective fashion, problems which have long plagued persons attempting to remove a valve from any of a variety of compressed gas tanks such as propane tanks: a inexpensive and effective tool for easily removing the valve from such a tank without damaging the valve. The ideal pressure tank valve socket should provide a tool for easily and efficiently removing (or attaching) a valve from a pressurized gas tank. The ideal pressure tank valve socket should also be configured to avoid damage to the valve of such a tank. The ideal pressure tank valve socket should also be simple, inexpensive, rugged, and easy to use. | <SOH> SUMMARY OF THE INVENTION <EOH>The pressure tank valve socket of the instant invention is a tool for easily and safely removing the valve from a receptor on a propane tank without damaging the valve. The valve typically has a rotating control handle to control the flow of gas through the valve and a threaded male end or connector which screws into the receptor on the tank. Typically, a safety valve (in many cases referred to as an overfill protection device or OPD) protrudes at a right angle from the axis between the handle and the connector and a regulator connector protrudes from the valve opposite and a bit above the safety valve. Although there is some small variation in valves, the valves have parallel, opposed shoulders on either side of the valve between the safety valve and the regulator connector. In some cases, the handle may be removed and in some cases the handle is fixed. Some propane tanks, such as those used for recreational vehicles, have removable handles and an external regulator connector. The pressure tank valve socket of the instant invention is essentially a large socket which works on the same principle as the well known socket and handle arrangement. The unique and original features of the pressure tank valve socket involve a configuration which allows the socket to fit over the handle (if the particular valve has a fixed handle), the safety valve, and the regulator connector without bearing upon any of those elements. The pressure tank valve socket is configured such that the socket bears upon only the two shoulders found in the valve. These shoulder elements are the most sound elements of the valve, and the most capable of handling the turning pressure necessary to remove or attach the valve. The pressure tank valve socket of the instant invention fits over the valve inside the guard and engages the shoulder elements. The free end of the pressure tank valve socket includes a hex head stud which may be engaged by a conventional socket set handle, a conventional wrench, or similar device and used to remove or attach the valve from or to the propane tank. Because only the shoulders are engaged, the relatively fragile safety valve and regulator connector are never damaged when removing or attaching a valve. The pressure tank valve socket has three basic embodiments. One is used for a barbecue type tank with a fixed handle; one is used for the type of tank which is used, for instance, to power a forklift and which has a removable handle; the third type is used, for instance, in a recreational vehicle and has an external regulator connector. One of the major objects of the pressure tank valve socket of the present invention is to provide a tool for easily and efficiently removing (or attaching) a valve from a pressure tank. Another objective of the present invention is to be configured to avoid damage to the pressure tank valve. Another objective of the present invention is to provide a pressure tank valve socket which is simple, inexpensive, and easy to use. These and other features of the invention will become apparent when taken in consideration with the following detailed description and the drawings. | 20040302 | 20051018 | 20050908 | 76659.0 | 0 | WALTON, GEORGE L | PRESSURE TANK VALVE SOCKET | SMALL | 0 | ACCEPTED | 2,004 |
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10,791,289 | ACCEPTED | Article of footwear having a textile upper | An article of footwear and a method of manufacturing the article of footwear are disclosed. The footwear may include an upper and a sole structure. The upper incorporates a textile element with edges that are joined together to define at least a portion of a void for receiving a foot. The textile element may also have a first area and a second area with a unitary construction. The first area is formed of a first stitch configuration, and the second area is formed of a second stitch configuration that is different from the first stitch configuration to impart varying textures to a surface of the textile element. Various warp knitting or weft knitting processes may be utilized to form the textile element. | 1. An article of footwear comprising: an upper incorporating a textile element formed through a weft knitting process, the textile element having edges that are joined together to define at least a portion of a void for receiving a foot; and a sole structure secured to the upper. 2. The article of footwear recited in claim 1, wherein the textile element forms at least a portion of a lateral side, a medial side, and an instep region of the upper. 3. The article of footwear recited in claim 1, wherein the edges include a pair of first edges that are joined to form a first seam extending longitudinally along a lower region of the upper. 4. The article of footwear recited in claim 3, wherein the edges include a pair of second edges that are joined to form a second seam extending along a heel region of the upper. 5. The article of footwear recited in claim 4, wherein the second seam extends vertically. 6. The article of footwear recited in claim 4, wherein the edges include at least a pair of third edges that are joined to form a third seam extending through a forefoot area of the upper. 7. The article of footwear recited in claim 1, wherein the textile element has a first area and a second area with a unitary construction, the first area being formed of a first stitch type, and the second area being formed of a second stitch type that is different from the first stitch type to impart varying textures to a surface of the textile element. 8. The article of footwear recited in claim 7, wherein the first stitch type provides a substantially smooth texture to the first area. 9. The article of footwear recited in claim 8, wherein the second stitch type provides a generally rough texture to the second area. 10. The article of footwear recited in claim 7, wherein at least one of the first stitch type and the second stitch type form an aperture in the textile element. 11. The article of footwear recited in claim 1, wherein the textile element is one of an exterior layer, an intermediate layer, and an interior layer of the upper. 12. The article of footwear recited in claim 1, wherein the upper includes an exterior layer, an intermediate layer, and an interior layer, and the textile element forms at least a portion of the interior layer. 13. The article of footwear recited in claim 1, wherein the textile layer forms at least a portion of both an interior surface and an exterior surface of the upper. 14. The article of footwear recited in claim 13, wherein at least one additional element is secured to the exterior surface and forms a portion of the exterior surface. 15. The article of footwear recited in claim 14, wherein the additional element is secured to a forefoot area of the upper. 16. The article of footwear recited in claim 14, wherein the additional element is secured to a heel area of the upper. 17. The article of footwear recited in claim 1, wherein the textile element forms an interior surface of the upper. 18. The article of footwear recited in claim 1, wherein the weft knitting process is circular knitting. 19. The article of footwear recited in claim 1, wherein the weft knitting process is flat knitting. 20. An article of footwear comprising: an upper incorporating a textile element formed through a weft knitting process, the textile element having a first area and a second area with a unitary construction, the first area being formed of a first stitch configuration, and the second area being formed of a second stitch configuration that is different from the first stitch configuration to impart varying properties to the textile element; and a sole structure secured to the upper. 21. The article of footwear recited in claim 20, wherein the first stitch configuration provides a substantially smooth texture to the first area, and the second stitch configuration provides a texture to the second area that is rougher than the smooth texture. 22. The article of footwear recited in claim 21, wherein the second stitch configuration forms a rib structure in the second area. 23. The article of footwear recited in claim 20, wherein at least one of the first stitch configuration and the second stitch configuration forms an aperture in the textile element. 24. The article of footwear recited in claim 20, wherein the textile element is one of an exterior layer, an intermediate layer, and an interior layer of the upper. 25. The article of footwear recited in claim 20, wherein the upper includes an exterior layer, an intermediate layer, and an interior layer, and the textile element forms at least a portion of the interior layer. 26. The article of footwear recited in claim 20, wherein the textile layer forms at least a portion of both an interior surface and an exterior surface of the upper. 27. The article of footwear recited in claim 20, wherein the textile element forms an interior surface of the upper. 28. An article of footwear comprising: an upper incorporating a textile element having edges that are joined together to form seams and define at least a portion of a void for receiving a foot, the seams including a first seam and a second seam, the first seam extending from a heel area to a forefoot area of the footwear along a lower surface of the upper, and the second seam extending vertically in the heel area; and a sole structure secured to the upper. 29. The article of footwear recited in claim 28, wherein the footwear includes a third seam extending through the forefoot area of the upper. 30. The article of footwear recited in claim 28, wherein the textile element has a first area and a second area with a unitary construction, the first area being formed of a first stitch type, and the second area being formed of a second stitch type that is different from the first stitch type to impart varying properties to the textile element. 31. The article of footwear recited in claim 30, wherein at least one of the first stitch type and the second stitch type form an aperture in the textile element. 32. The article of footwear recited in claim 30, wherein the varying properties include varying elasticity of the textile element. 33. The article of footwear recited in claim 30, wherein the varying properties include varying air permeability of the textile element. 34. The article of footwear recited in claim 28, wherein the textile element is one of an exterior layer, an intermediate layer, and an interior layer of the upper. 35. The article of footwear recited in claim 28, wherein the textile layer forms at least a portion of both an interior surface and an exterior surface of the upper. 36. The article of footwear recited in claim 28, wherein the textile layer forms an interior surface of the footwear, and at least one additional layer forms an exterior surface of the footwear. 37. The article of footwear recited in claim 28, wherein the textile element is formed through a weft knitting process. 38. The article of footwear recited in claim 37, wherein the weft knitting process is one of circular knitting and flat knitting. 39. The article of footwear recited in claim 28, wherein the textile element is formed through a warp knitting process. 40. The article of footwear recited in claim 39, wherein the warp knitting process is jacquard double needle-bar raschel. 41. An article of footwear comprising: an upper incorporating a textile element formed with a knitting machine, the textile element being removed from a textile structure that includes an outline of the textile element, and the textile element having edges that are joined together to define at least a portion of a void for receiving a foot; and a sole structure secured to the upper. 42. The article of footwear recited in claim 41, wherein the knitting machine is a wide-tube circular knitting machine. 43. The article of footwear recited in claim 41, wherein the knitting machine is a jacquard double needle-bar raschel knitting machine. 44. The article of footwear recited in claim 41, wherein the edges include a pair of first edges that are joined to form a first seam extending longitudinally along a lower region of the upper. 45. The article of footwear recited in claim 44, wherein the edges include a pair of second edges that are joined to form a second seam extending along a heel region of the upper. 46. The article of footwear recited in claim 45, wherein the edges include at least a pair of third edges that are joined to form a second seam extending through a forefoot area of the upper. 47. The article of footwear recited in claim 41, wherein the textile element has a first area and a second area with a unitary construction, the first area being formed of a first stitch type, and the second area being formed of a second stitch type that is different from the first stitch type to impart varying textures to a surface of the textile element. 48. The article of footwear recited in claim 41, wherein the textile element is one of an exterior layer, an intermediate layer, and an interior layer of the upper. 49. The article of footwear recited in claim 41, wherein the textile element forms an interior surface of the upper. 50. A method of manufacturing an article of footwear, the method comprising steps of: mechanically-manipulating a yarn with a circular knitting machine to form a cylindrical textile structure; removing at least one textile element from the textile structure; incorporating the textile element into an upper of the article of footwear. 51. The method recited in claim 50, wherein the step of mechanically-manipulating includes utilizing a wide-tube circular knitting machine. 52. The method recited in claim 50, wherein the step of mechanically-manipulating includes forming a texture in the cylindrical textile structure with a shape of the textile element. 53. The method recited in claim 50, wherein the step of mechanically manipulating includes forming the textile element to include a first area and a second area with a unitary construction, the first area being formed of a first stitch configuration, and the second area being formed of a second stitch configuration that is different from the first stitch configuration to impart varying textures to a surface of the textile element. 54. The method recited in claim 50, wherein the step of mechanically manipulating includes forming at least two textile elements in the cylindrical textile structure. 55. The method recited in claim 50, wherein the step of mechanically manipulating includes forming apertures in the textile element. 56. The method recited in claim 50, wherein the step of incorporating includes securing a first pair of edges of the textile element to each other to form a first seam that extends along a lower region of the upper. 57. The method recited in claim 56, wherein the step of incorporating further includes securing a second pair of edges of the textile element to each other to form a second seam that extends along a heel region of the upper. 58. A method of manufacturing an article of footwear, the method comprising steps of: mechanically-manipulating a yarn with a knitting machine to form a textile structure having an outline of at least one textile element; removing the textile element from the textile structure; incorporating the textile element into an upper of the article of footwear. 59. The method recited in claim 58, wherein the step of mechanically-manipulating includes utilizing a wide-tube circular knitting machine. 60. The method recited in claim 59, wherein the step of mechanically-manipulating includes forming a texture in the cylindrical textile structure with a shape of the textile element. 61. The method recited in claim 58, wherein the step of mechanically-manipulating includes utilizing a jacquard double needle-bar raschel knitting machine. 62. The method recited in claim 58, wherein the step of mechanically manipulating includes forming the textile element to include a first area and a second area with a unitary construction, the first area being formed of a first stitch configuration, and the second area being formed of a second stitch configuration that is different from the first stitch configuration to impart varying textures to a surface of the textile element. 63. The method recited in claim 58, wherein the step of incorporating includes securing a first pair of edges of the textile element to each other to form a first seam that extends along a lower region of the upper. 64. The method recited in claim 58, wherein the step of incorporating further includes securing a second pair of edges of the textile element to each other to form a second seam that extends along a heel region of the upper. 65. An article of footwear comprising: an upper incorporating a textile element formed through a flat knitting process, the textile element having a first area and a second area with a unitary construction, the first area having a first set of properties, and the second area having a second set of properties that are different from the first set of properties to impart varying characteristics to the textile element; and a sole structure secured to the upper. 66. The article of footwear recited in claim 65, wherein the first set of properties and the second set of properties are at least one of a stitch configuration and a yarn type. 67. The article of footwear recited in claim 65, wherein the textile element is one of an exterior layer, an intermediate layer, and an interior layer of the upper. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to footwear. The invention concerns, more particularly, an article of footwear incorporating an upper that is at least partially formed from a textile material. 2. Description of Background Art Conventional articles of athletic footwear include two primary elements, an upper and a sole structure. The upper provides a covering for the foot that securely receives and positions the foot with respect to the sole structure. In addition, the upper may have a configuration that protects the foot and provides ventilation, thereby cooling the foot and removing perspiration. The sole structure is secured to a lower surface of the upper and is generally positioned between the foot and the ground. In addition to attenuating ground reaction forces and absorbing energy (i.e., imparting cushioning), the sole structure may provide traction and control potentially harmful foot motion, such as over pronation. Accordingly, the upper and the sole structure operate cooperatively to provide a comfortable structure that is suited for a wide variety of ambulatory activities, such as walking and running. The general features and configuration of the conventional upper are discussed in greater detail below. The upper forms a void on the interior of the footwear for receiving the foot. The void has the general shape of the foot, and access to the void is provided by an ankle opening. Accordingly, the upper extends over the instep and toe areas of the foot, along the medial and lateral sides of the foot, and around the heel area of the foot. A lacing system is often incorporated into the upper to selectively increase the size of the ankle opening and permit the wearer to modify certain dimensions of the upper, particularly girth, to accommodate feet with varying proportions. In addition, the upper may include a tongue that extends under the lacing system to enhance the comfort of the footwear, and the upper may include a heel counter to limit movement of the heel. Various materials may be utilized in manufacturing the upper. The upper of an article of athletic footwear, for example, may be formed from multiple material layers that include an exterior layer, an intermediate layer, and an interior layer. The materials forming the exterior layer of the upper may be selected based upon the properties of wear-resistance, flexibility, and air-permeability, for example. With regard to the exterior layer, the toe area and the heel area may be formed of leather, synthetic leather, or a rubber material to impart a relatively high degree of wear-resistance. Leather, synthetic leather, and rubber materials may not exhibit the desired degree of flexibility and air-permeability. Accordingly, various other areas of the exterior layer of the upper may be formed from a synthetic or natural textile. The exterior layer of the upper may be formed, therefore, from numerous material elements that each impart different properties to specific portions of the upper. An intermediate layer of the upper may be formed from a lightweight polymer foam material that provides cushioning and protects the foot from objects that may contact the upper. Similarly, an interior layer of the upper may be formed of a moisture-wicking textile that removes perspiration from the area immediately surrounding the foot. In some articles of athletic footwear, the various layers may be joined with an adhesive, and stitching may be utilized to join elements within a single layer or to reinforce specific areas of the upper. Although the materials selected for the upper vary significantly, textile materials often form at least a portion of the exterior layer and interior layer. A textile may be defined as any manufacture from fibers, filaments, or yarns characterized by flexibility, fineness, and a high ratio of length to thickness. Textiles generally fall into two categories. The first category includes textiles produced directly from webs of filaments or fibers by randomly interlocking to construct non-woven fabrics and felts. The second category includes textiles formed through a mechanical manipulation of yarn, thereby producing a woven fabric, for example. Yarn is the raw material utilized to form textiles in the second category. In general, yarn is defined as an assembly having a substantial length and relatively small cross-section that is formed of at least one filament or a plurality of fibers. Fibers have a relatively short length and require spinning or twisting processes to produce a yarn of suitable length for use in textiles. Common examples of fibers are cotton and wool. Filaments, however, have an indefinite length and may merely be combined with other filaments to produce a yarn suitable for use in textiles. Modern filaments include a plurality of synthetic materials such as rayon, nylon, polyester, and polyacrylic, with silk being the primary, naturally-occurring exception. Yarn may be formed of a single filament, which is conventionally referred to as a monofilament yarn, or a plurality of individual filaments grouped together. Yarn may also include separate filaments formed of different materials, or the yarn may include filaments that are each formed of two or more different materials. Similar concepts also apply to yarns formed from fibers. Accordingly, yarns may have a variety of configurations that generally conform to the definition provided above. The various techniques for mechanically manipulating yarn into a textile include interweaving, intertwining and twisting, and interlooping. Interweaving is the intersection of two yarns that cross and interweave at right angles to each other. The yarns utilized in interweaving are conventionally referred to as warp and weft. Intertwining and twisting encompasses procedures such as braiding and knotting where yarns intertwine with each other to form a textile. Interlooping involves the formation of a plurality of columns of intermeshed loops, with knitting being the most common method of interlooping. The textiles utilized in footwear uppers generally provide a lightweight, air-permeable structure that is flexible and comfortably receives the foot. In order to impart other properties to the footwear, including durability and stretch-resistance, additional materials are commonly combined with the textile, including leather, synthetic leather, or rubber, for example. With regard to durability, U.S. Pat. No. 4,447,967 to Zaino discloses an upper formed of a textile material that has a polymer material injected into specific zones to reinforce the zones against abrasion or other forms of wear. Regarding stretch resistance, U.S. Pat. No. 4,813,158 to Brown and U.S. Pat. No. 4,756,098 to Boggia both disclose a substantially inextensible material that is secured to the upper, thereby limiting the degree of stretch in specific portions of the upper. From the perspective of manufacturing, utilizing multiple materials to impart different properties to an article of footwear may be an inefficient practice. For example, the various materials utilized in a conventional upper are not generally obtained from a single supplier. Accordingly, a manufacturing facility must coordinate the receipt of specific quantities of materials with multiple suppliers that may have distinct business practices or may be located in different regions or countries. The various materials may also require additional machinery or different assembly line techniques to cut or otherwise prepare the material for incorporation into the footwear. In addition, incorporating separate materials into an upper may involve a plurality of distinct manufacturing steps requiring multiple individuals. Employing multiple materials, in addition to textiles, may also detract from the breathability of footwear. Leather, synthetic leather, or rubber, for example, are not generally permeable to air. Accordingly, positioning leather, synthetic leather, or rubber on the exterior of the upper may inhibit air flow through the upper, thereby increasing the amount of perspiration, water vapor, and heat trapped within the upper and around the foot. SUMMARY OF THE INVENTION The present invention is an upper for an article of footwear, the upper incorporating a textile element formed with a knitting machine, for example. In one aspect of the invention, the textile element has edges that are joined together to define at least a portion of a void for receiving a foot. In another aspect of the invention, the textile element has a first area and a second area of unitary construction. The first area is formed of a first stitch configuration, and the second area is formed of a second stitch configuration that is different from the first stitch configuration to impart varying textures to a surface of the textile element. The knitting machine may have a configuration that forms the textile element through either warp knitting or weft knitting. Another aspect of the invention involves a method of manufacturing an article of footwear. The method includes a step of mechanically-manipulating a yarn with a circular knitting machine, for example, to form a cylindrical textile structure. In addition, the method involves removing at least one textile element from the textile structure, and incorporating the textile element into an upper of the article of footwear. In another aspect of the invention, an article of footwear has an upper and a sole structure secured to the upper. The upper incorporates a textile element formed with a knitting machine. The textile element is removed from a textile structure that includes an outline of the textile element, and the textile element has edges that are joined together to define at least a portion of a void for receiving a foot. The advantages and features of novelty characterizing the present invention are pointed out with particularity in the appended claims. To gain an improved understanding of the advantages and features of novelty, however, reference may be made to the following descriptive matter and accompanying drawings that describe and illustrate various embodiments and concepts related to the invention. DESCRIPTION OF THE DRAWINGS The foregoing Summary of the Invention, as well as the following Detailed Description of the Invention, will be better understood when read in conjunction with the accompanying drawings. FIG. 1 is a lateral elevational view of an article of footwear having an upper in accordance with the present invention. FIG. 2 is a lateral elevational view of the upper. FIG. 3 is a top plan view of the upper. FIG. 4 is a rear elevational view of the upper. FIG. 5 is a bottom plan view of the upper. FIG. 6 is a first cross-sectional view of the upper, as defined by section line 6-6 in FIG. 2. FIG. 7 is a second cross-sectional view of the upper, as defined by section line 7-7 in FIG. 2. FIG. 8 is a plan view of a textile element that forms at least a portion of the upper. FIG. 9 is a perspective view of a textile structure that incorporates two of the textile element. FIG. 10 is a plan view of another textile element. FIG. 11 is a plan view of yet another textile element. FIG. 12 is a lateral elevational view of another article of footwear having an upper in accordance with the present invention. FIG. 13 is a lateral elevational view of yet another article of footwear having an upper in accordance with the present invention. FIG. 14 is a cross-sectional view of the footwear depicted in FIG. 13, as defined by section line 14-14. DETAILED DESCRIPTION OF THE INVENTION The following discussion and accompanying figures disclose an article of footwear 10 and a method of manufacturing footwear 10, or components thereof, in accordance with the present invention. Footwear 10 is depicted in the figures and discussed below as having a configuration that is suitable for athletic activities, particularly running. The concepts disclosed with respect to footwear 10 may, however, be applied to footwear styles that are specifically designed for a variety of other athletic activities, including basketball, baseball, football, soccer, walking, and hiking, for example, and may also be applied to various non-athletic footwear styles. Accordingly, one skilled in the relevant art will recognize that the concepts disclosed herein may be applied to a wide range of footwear styles and are not limited to the specific embodiments discussed below and depicted in the figures. The primary elements of footwear 10 are depicted in FIG. 1 as being a sole structure 20 and an upper 30. Sole structure 20 is secured to a lower portion of upper 30 and provides a durable, wear-resistant component that imparts cushioning as footwear 10 impacts the ground. Upper 30 is at least partially formed from a textile element 40 that defines an interior void for comfortably receiving a foot and securing a position of the foot relative to sole structure 20. Various edges of textile element 40 are then secured together to form the shape of upper 30. In some embodiments, textile element 40 may form substantially all of upper 30, or textile element 40 may only be a portion of an upper. Sole structure 20 has a generally conventional configuration that includes a midsole 21 and an outsole 22. Midsole 21 is secured to a lower portion of upper 30 and is formed of a polymer foam material, such as ethylvinylacetate or polyurethane. Accordingly, midsole 21 attenuates ground reaction forces and absorbs energy (i.e., provides cushioning) as sole structure 20 impacts the ground. To enhance the force attenuation and energy absorption characteristics of sole structure 20, midsole 21 may incorporate a fluid-filled bladder, as disclosed in U.S. Pat. Nos. 4,183,156 and 4,219,945 to Rudy. Alternately or in combination, midsole 21 may incorporate a plurality of discrete, columnar support elements, as disclosed in U.S. Pat. Nos. 5,343,639 and 5,353,523 to Kilgore et al. Outsole 22 is secured to a lower surface of midsole 21 and may be formed from carbon black rubber compound to provide a durable, wear-resistant surface for engaging the ground. Outsole 22 may also incorporate a textured lower surface to enhance the traction characteristics of footwear 10. In addition, footwear 10 may include an insole (not depicted), which is a relatively thin, cushioning member located within upper 30 and adjacent to a plantar surface of the foot for enhancing the comfort of footwear 10. Sole structure 20 is described above as having the elements of a conventional sole structure for athletic footwear. Other footwear styles, including, dress shoes and boots, for example, may have other types of conventional sole structures specifically tailored for use with the respective types of footwear. In addition to a conventional configuration, however, sole structure 20 may also exhibit a unique, non-conventional structure. Accordingly, the particular configuration of sole structure 20 may vary significantly within the scope of the present invention to include a wide range of configurations, whether conventional or non-conventional. Upper 30 is depicted in FIGS. 2-7 as having a lateral region 31, an opposite medial region 32, an instep region 33, a lower region 34, and a heel region 35. Lateral region 31 extends through a longitudinal length of footwear 10 and is generally configured to contact and cover a lateral side of the foot. Medial region 32 has a similar configuration that generally corresponds with a medial side of the foot. Instep region 33 is positioned between lateral region 31 and medial region 32, and instep region 33 extends over an instep area of the foot. Lower region 34 forms a bottom surface of upper 30 and also extends through the longitudinal length of footwear 10. Heel region 35 forms a rear portion of upper 30 and is generally configured to contact and cover a heel area of the foot. In addition, lateral region 31, medial region 32, instep region 33, and heel region 35 cooperatively define an ankle opening 36 for providing the foot with access to the void within upper 30. Upper 30 is at least partially formed from textile element 40, which forms regions 31-35, and may also include laces or other elements associated with a conventional upper for footwear. Textile element 40 is a single material element that is formed to exhibit a unitary (i.e., one-piece) construction, and textile element 40 is formed or otherwise shaped to extend around the foot. As depicted in FIGS. 2-7, textile element 40 forms both an exterior surface and an interior surface of upper 30. Textile element 40 may be formed as a part of a larger textile element. Textile element 40 is then removed from the larger textile element and various edges of textile element 40 are secured together to form the shape of upper 30. A plurality of seams 51-54 are formed, therefore, when joining the edges of the textile element. Seam 51 extends along the longitudinal length of lower region 34 and is centrally-located with respect to lateral region 31 and medial region 32. Seam 52 is also centrally-located and extends upward along heel region 35. A seam 53 is positioned in a forefoot area of upper 30 and joins a portion of lower region 34 with both of lateral region 31 and medial region 32. In addition, a seam 54 is positioned in a rear area of upper 30 and joins a portion of lower region 34 with heel region 35. Textile element 40 exhibits the general shape depicted in FIG. 8 prior to the formation of seams 51-54. Following formation of seams 51-54, however, textile element 40 exhibits the shape of upper 30 depicted in FIGS. 2-7. Seams 51-54 are formed by securing various edges of textile element 40 together. More specifically, (1) seam 51 is formed by securing an edge 41a with an edge 41b; (2) seam 52 is formed by securing an edge 42a with an edge 42b; (3) a first portion of seam 53 is formed by securing an edge 43a with an edge 43b (4) a second portion of seam 53 is formed by securing an edge 43c with an edge 43d; (5) a first portion of seam 54 is formed by securing an edge 44a with an edge 44b; and (6) a second portion of seam 54 is formed by securing an edge 44c with an edge 44d. Referring to FIG. 8, the positions of regions 31-35 and ankle opening 36 are identified to provide a frame of reference relating to the various portions of textile element 40. In order to join edges 41a and 41b to form seam 51, textile element 40 is folded or otherwise overlapped such that edge 41a is placed adjacent to edge 41b. Stitching, an adhesive, or heat bonding, for example, is then utilized to secure edge 41a and edge 41b. Textile element 40, as depicted in FIG. 8, has a generally planar configuration. Upon the formation of seam 51, however, one portion of textile element 40 overlaps the other portion of textile element 40. The volume between the overlapping portions effectively forms a portion of the void within upper 30 for receiving the foot. The folding or overlapping of textile element 40 to form seam 51 places edge 42a adjacent to edge 42b, which facilitates the formation of seam 52. With reference to FIG. 8, an edge 45 forms a generally u-shaped area in textile element 40. Upon the joining of edges 42a and 42b to form seam 52, the u-shaped area becomes an aperture in textile element 40 and effectively forms ankle opening 36. Each of edges 43a-43d and edges 44a-44d are formed from a generally v-shaped area of textile element 40. Accordingly, seams 53 and 54 may be formed by closing the v-shaped areas and securing the various edges together. Following the formation of each of seams 51-54, the manufacturing of upper 30 is essentially complete. Various finishing steps may be performed, such as reinforcing ankle opening 36, for example. Upper 30 (i.e., textile element 40) is then secured to sole structure 20, with an adhesive, for example. The insole is then placed into the void within upper 30 and adjacent to lower region 34. In some embodiments, various reinforcing members may be added to the exterior or interior surface of upper 20 in order to limit the degree of stretch in upper 20 or provide enhanced wear-resistance. In addition, a lacing system may be added to provide adjustability. Textile element 40 is a single material element with a unitary construction, as discussed above. As defined for purposes of the present invention, unitary construction is intended to express a configuration wherein portions of a textile element are not joined together by seams or other connections, as depicted with textile element 40 in FIG. 8. Although the various edges 41a-44d are joined together to form seams 51-54, the various portions of textile element 40 are formed as an unitary element without seams, as discussed below. Textile element 40 is primarily formed from one or more yarns that are mechanically-manipulated through either an interweaving, intertwining and twisting, or interlooping process, for example. As discussed in the Background of the Invention section above, interweaving is the intersection of two yarns that cross and interweave at right angles to each other. The yarns utilized in interweaving are conventionally referred to as warp and weft. Intertwining and twisting encompasses procedures such as braiding and knotting where yarns intertwine with each other to form a textile. Interlooping involves the formation of a plurality of columns of intermeshed loops, with knitting being the most common method of interlooping. Textile element 40 may, therefore, be formed from one of these processes for manufacturing a textile. A variety of mechanical processes have been developed to manufacture a textile. In general, the mechanical processes may be classified as either warp knitting or weft knitting. With regard to warp knitting, various specific sub-types that may be utilized to manufacture a textile include tricot, raschel, and double needle-bar raschel (which further includes jacquard double needle-bar raschel). With regard to weft knitting, various specific sub-types that may be utilized to manufacture a textile include circular knitting and flat knitting. Various types of circular knitting include sock knitting (narrow tube), body garment (seamless or wide tube), and jacquard. Textile element 40 may be formed through any of the mechanical processes discussed above. Accordingly, textile element 40 may be formed on either a warp knitting machine or a weft knitting machine. One suitable knitting machine for forming textile element 40 is a wide-tube circular knit jacquard machine. Another suitable knitting machine for forming textile element 40 is a wide-tube circular knitting machine that is produced in the Lonati Group by Santoni S.p.A. of Italy under the SM8 TOP1 model number. This Santoni S.p.A. wide-tube circular knitting machine may form a textile structure having a diameter that ranges from 10 inches to 20 inches, with 8 feeds for each diameter. The machine exhibits a maximum 140 revolutions per minute for 10 inch diameters, and a maximum 120 revolutions per minute for 13 inch diameters. Furthermore, the machine gauge is variable between 16, 22, 24, 26, 28, and 32 needles per inch, and is suitable for various needle gauges ranging from 48 to 75. A wide-tube circular knitting machine, as produced by Santoni S.p.A., forms a generally cylindrical textile structure and is capable of forming various types of stitches within a single textile structure. In general, the wide-tube circular knitting machine may be programmed to alter the design on the textile structure through needle selection. That is, the type of stitch that is formed at each location on the textile structure may be selected by programming the wide-tube circular knitting machine such that specific needles either accept or do not accept yarn at each stitch location. In this manner, various patterns, textures, or designs may be selectively and purposefully imparted to the textile structure. An example of a textile structure 60 that may be formed with a wide-tube circular knitting machine is depicted in FIG. 9. Textile structure 60 has a generally cylindrical configuration, and the types of stitches vary throughout textile structure 60 so that a pattern is formed with the outline of textile element 40. That is, differences in the stitches within textile structure 60 form an outline with the shape and proportions of textile element 40. The Santoni S.p.A. wide-tube circular knitting machine may form a textile structure having a diameter that ranges from 10 inches to 16 inches, as discussed above. Assuming that textile structure 60 exhibits a diameter of 10 inches, then the circumference of textile structure 60 is approximately 31 inches. In many circumstances, the total width of textile element 40 will be approximately 12 inches, depending upon the size of footwear 10. The outlines for at least two textile elements 40 may, therefore, be formed on textile structure 60. Referring to FIG. 9, the outline of textile element 40 is depicted on a front portion of textile structure 60, and the outline of another textile element 40 is depicted on a rear portion of textile structure 60. Accordingly, a first textile element 40 and a second textile element 40 may be simultaneously formed in a single textile structure 60. As the diameter of textile element 60 is increased or the width of textile element 40 decreases, however, an even greater number of textile elements 40 may be outlined on textile structure 60. Textile structure 60 may be formed with a wide-tube circular knitting machine, as discussed above. The types of stitches that form textile structure 60 may be varied to form an outline of one or more textile elements 40 on textile structure 60. That is, the wide-tube circular knitting machine may be programmed to form different types of stitches in textile structure 60 so as to outline one or more textile elements 40. Each textile element 40 is then removed from textile structure 60 with a die-cutting, laser-cutting, or other conventional cutting operation. Once textile element 40 is removed from textile structure 60, seams 51-54 may be formed and textile element 40 may be incorporated into footwear 10. The yarn forming textile element 40 may be generally defined as an assembly having a substantial length and relatively small cross-section that is formed of at least one filament or a plurality of fibers. Fibers have a relatively short length and require spinning or twisting processes to produce a yarn of suitable length for use in an interlooping process. Common examples of fibers are cotton and wool. Filaments, however, have an indefinite length and may merely be combined with other filaments to produce a yarn suitable for use in an interlooping process. Modern filaments include a plurality of synthetic materials such as rayon, nylon, polyester, and acrylic, with silk being the primary, naturally-occurring exception. Yarn may be formed of a single filament (conventionally referred to as a monofilament yarn) or a plurality of individual filaments. Yarn may also be formed of separate filaments formed of different materials, or the yarn may be formed of filaments that are each formed of two or more different materials. Similar concepts also apply to yarns formed from fibers. Accordingly, yarns may have a variety of configurations within the scope of the present invention that generally conform to the definition provided above. In order to provide the stretch and recovery properties to upper 30, and particularly textile element 40, a yarn that incorporates an elastane fiber may be utilized. Elastane fibers are available from E.I. duPont de Nemours Company under the LYCRA trademark. Such fibers may have the configuration of covered LYCRA, wherein the fiber includes a LYCRA core that is surrounded by a nylon sheath. One suitable yarn, for example, includes a 70 denier elastane core that is covered with nylon having a 2 ply, 80 denier, 92 filament structure. Other fibers or filaments exhibiting elastic properties may also be utilized. As discussed above, a yarn that incorporates elastane fibers is suitable for textile element 40. A plurality of other yarns, whether elastic or inelastic, are also suitable for textile element 40. The characteristics of the yarn selected for textile element 40 depend primarily upon the materials that form the various filaments and fibers. Cotton, for example, provides a soft hand, natural aesthetics, and biodegradability. Elastane fibers, as discussed above, provide substantial stretch and recoverability. Rayon provides high luster and moisture absorption. Wool also provides high moisture absorption, in addition to insulating properties. Polytetrafluoroethylene coatings may provide a low friction contact between the textile and the skin. Nylon is a durable and abrasion-resistant material with high strength. Finally, polyester is a hydrophobic material that also provides relatively high durability. Accordingly, the materials comprising the yarn may be selected to impart a variety of physical properties to textile element 40, and the physical properties may include, for example, strength, stretch, support, stiffness, recovery, fit, and form. Textile element 40 is depicted as having a generally smooth, non-varied stitch configuration. That is, similar stitches are utilized throughout textile element 40 to impart a common texture to the various portions of textile element 40. As discussed above, however, a wide-tube circular knitting machine is generally capable of forming various types of stitches within a single textile structure. The wide-tube circular knitting machine may, therefore, vary the stitches within textile element 40 to produce various patterns, designs, or textures, for example. Various types of stitches may also be formed with other types of knitting machines. With reference to FIG. 10, a textile element 40′ with the general shape of textile element 40 is depicted as having various areas with different textures. For example, a central area that corresponds with instep region 33 has a first texture 46′ that is generally smooth. In addition, textile element 40′ includes a second texture 47′ that is a plurality of longitudinal ribs. When incorporated into footwear 10, the ribs will extend longitudinally along lateral region 31 and medial region 32, and the ribs may extend into heel region 35. The ribs may be present for aesthetic purposes, or may affect the stretch properties of upper 20, for example. Accordingly, textile element 40′ exhibits areas with different textures in a single element of textile material. Many conventional articles of footwear incorporate uppers with various material elements that each exhibit different properties. For example, a first material element may be smooth, and a second material element may be textured. The first and second material elements are then stitched together to form a portion of the conventional upper. Textile element 40′ also exhibits smooth and textured areas. In contrast with the conventional upper, however, first texture 46′ and second texture 47′ are incorporated into a single, unitary element of textile, rather than two separate elements that are stitched or otherwise joined together. A textile structure 40″ is depicted in FIG. 11 and has the general shape of both textile element 40 and textile element 40′. Textile element 40″ includes areas with three different textures. A first texture 46″ is generally smooth and has the configuration of various strips that extends laterally across areas corresponding with lateral region 31, medial region 32, and instep region 33. Various portions of textile element 40″ also include a second texture 47″, which is generally rough in comparison with first texture 46″. In addition, the area of textile element 40″ corresponding with instep region 33 includes a third texture 48″. The different textures 46″-48″ are formed by merely varying the type of stitch formed by the wide-tube circular knitting machine at each location of textile element 40″. Textures 46″-48″ may exhibit aesthetic differences, or the differences may be structural. For example, the degree of stretch in areas with textures 46″-48″ may be different, or the wear resistance of the areas may vary depending upon the stitch utilized. The air-permeability of textile element 40″ may also vary in the different areas. Third texture 48″ is formed to include a plurality of apertures that extend through textile element 40″. The apertures may be formed by omitting stitches at specific locations during the wide-tube circular knitting process, and the apertures facilitate the transfer of air between the void within upper 20 and the area outside of upper 20. Accordingly, the various stitches formed in textile element 40″, or one of textile elements 40 or 40′, may be utilized to vary the texture, physical properties, or aesthetics of footwear 10 within a single, unitary element of material. In addition to varying the stitch types to form textures 46′-47′ and 46″-48″, the type of yarn utilized in various areas of textile elements 40′ and 40″ may be changed to impart different properties. As discussed above, yarn may be formed from cotton, wool, elastane, rayon, nylon, and polyester, for example. Each of these yarn types may impart differing properties to the areas corresponding with textures 46′-47′ and 46″-48″. For example, elastane may be utilized to impart stretch, wool may be utilized for insulation, and nylon may be utilized for durability. Accordingly, different yarn types may be utilized to impart different properties. The types of knitting that may be utilized to form different zones with different properties (e.g., yarn characteristics, textures, etc.) may vary significantly to include the various warp knitting and weft knitting processes discussed earlier, such as tricot, raschel, double needle-bar raschel, circular knitting, and flat knitting, for example. An article of footwear 110 is depicted in FIG. 12 and includes a sole structure 120 and an upper 130. Upper 130 includes a textile element 140 having the general configuration of textile element 40. As with textile element 40, textile element 140 forms both an exterior surface and an interior surface of upper 130. In addition, upper 130 includes a lace 131 and a plurality of elements 132-135 that also form a portion of the exterior surface. Lace 131 extends through a plurality of apertures formed in textile element 140. The apertures may be formed by omitting stitches at specific locations. Element 132 is positioned in a forefoot area of footwear 110 and may be formed of leather or rubber, for example, to provide additional wear-resistance. Element 133 extends around the ankle opening to reinforce and limit stretch in the area of the ankle opening. Element 134 extends around the heel region to counter movement of the heel and seat the heel above sole structure 120. Furthermore, elements 135 are substantially inextensible strips of material, such as leather or synthetic leather, that limit stretch on the lateral side of footwear 110. Whereas upper 30 was almost exclusively formed by textile element 40, upper 130 also includes lace 131 and elements 132-135. Accordingly, an upper in accordance with the present invention may incorporate a plurality of additional components. Another article of footwear 210 is depicted in FIGS. 13-14 and includes a sole structure 220 and an upper 230. Upper 230 includes a textile element 240 that forms an interior layer. In addition, upper 230 includes an intermediate layer 250 and an exterior layer 260. As discussed in the Background of the Invention section above, the upper of a conventional article of footwear may be formed from multiple material layers that include an exterior layer, a intermediate layer, and an interior layer. The materials forming the exterior layer of the upper may be selected based upon the properties of wear-resistance, flexibility, and air-permeability, for example. The intermediate layer of the upper may be formed from a lightweight polymer foam material that provides cushioning and protects the foot from objects that may contact the upper. Similarly, an interior layer of the upper may be formed of a moisture-wicking textile that removes perspiration from the area immediately surrounding the foot. Upper 230 has a configuration that is similar to the configuration of the conventional upper in that various material layers are utilized. In contrast with the conventional upper, however, the interior layer is formed of textile element 240, which is manufactured through the process discussed above. That is, textile element 240 is a single element of textile that forms the interior layer of upper 230. A benefit to utilizing textile element 240 for the interior layer is that textile element 240 includes few seams that may contact the foot. In addition, the stitches utilized at various locations of textile element 240 may modify the texture of the interior surface of upper 230, thereby limiting the degree of slip that occurs between the foot and upper 230 or enhancing the air-permeability of upper 230 in specific locations. Various warp knitting or weft knitting processes may be utilized to form textile element 40, or the various other textile elements discussed above. An advantage of this process is that various stitches may be incorporated into specific locations of textile element 40 to modify the physical properties or aesthetics of textile element 40. Whereas a conventional upper includes various elements that stitched or adhesively joined, textile element 40 is a single, unitary element of material. From the perspective of manufacturing, utilizing multiple materials to impart different properties to an article of footwear may be an inefficient practice. By forming textile element 40 to be a single, unitary element of material, however, efficiency is increased in that upper 20 may include a single textile element, rather than numerous joined elements. A variety of knitting processes may be utilized to form textile element 40, as discussed above. As a specific example, a jacquard double needle-bar raschel knitting machine may be utilized to form a flat textile structure, and may also be utilized to form the textile structure to have the configuration of a spacer mesh textile. Unlike textile structure 60, which exhibits a generally cylindrical configuration, the textile structure formed with the jacquard double needle-bar raschel knitting machine will have a flat configuration. Like textile structure 60, however, an outline of a textile element may be imparted to the textile structure formed with the jacquard double needle-bar raschel knitting machine. That is, differences in the stitches within the textile structure may form an outline with the shape and proportions of the intended textile element. Accordingly, the textile element may be removed from the textile structure and incorporated into footwear 10. In addition, the jacquard double needle-bar raschel knitting machine may be utilized to impart various textures, different properties, or different yarn types to the textile element. Similarly, other types of knitting, such as a flat knitting, may be utilized within the scope of the present invention to impart various textures, different properties, or different yarn types to the textile element. The present invention is disclosed above and in the accompanying drawings with reference to a variety of embodiments. The purpose served by the disclosure, however, is to provide an example of the various features and concepts related to the invention, not to limit the scope of the invention. One skilled in the relevant art will recognize that numerous variations and modifications may be made to the embodiments described above without departing from the scope of the present invention, as defined by the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to footwear. The invention concerns, more particularly, an article of footwear incorporating an upper that is at least partially formed from a textile material. 2. Description of Background Art Conventional articles of athletic footwear include two primary elements, an upper and a sole structure. The upper provides a covering for the foot that securely receives and positions the foot with respect to the sole structure. In addition, the upper may have a configuration that protects the foot and provides ventilation, thereby cooling the foot and removing perspiration. The sole structure is secured to a lower surface of the upper and is generally positioned between the foot and the ground. In addition to attenuating ground reaction forces and absorbing energy (i.e., imparting cushioning), the sole structure may provide traction and control potentially harmful foot motion, such as over pronation. Accordingly, the upper and the sole structure operate cooperatively to provide a comfortable structure that is suited for a wide variety of ambulatory activities, such as walking and running. The general features and configuration of the conventional upper are discussed in greater detail below. The upper forms a void on the interior of the footwear for receiving the foot. The void has the general shape of the foot, and access to the void is provided by an ankle opening. Accordingly, the upper extends over the instep and toe areas of the foot, along the medial and lateral sides of the foot, and around the heel area of the foot. A lacing system is often incorporated into the upper to selectively increase the size of the ankle opening and permit the wearer to modify certain dimensions of the upper, particularly girth, to accommodate feet with varying proportions. In addition, the upper may include a tongue that extends under the lacing system to enhance the comfort of the footwear, and the upper may include a heel counter to limit movement of the heel. Various materials may be utilized in manufacturing the upper. The upper of an article of athletic footwear, for example, may be formed from multiple material layers that include an exterior layer, an intermediate layer, and an interior layer. The materials forming the exterior layer of the upper may be selected based upon the properties of wear-resistance, flexibility, and air-permeability, for example. With regard to the exterior layer, the toe area and the heel area may be formed of leather, synthetic leather, or a rubber material to impart a relatively high degree of wear-resistance. Leather, synthetic leather, and rubber materials may not exhibit the desired degree of flexibility and air-permeability. Accordingly, various other areas of the exterior layer of the upper may be formed from a synthetic or natural textile. The exterior layer of the upper may be formed, therefore, from numerous material elements that each impart different properties to specific portions of the upper. An intermediate layer of the upper may be formed from a lightweight polymer foam material that provides cushioning and protects the foot from objects that may contact the upper. Similarly, an interior layer of the upper may be formed of a moisture-wicking textile that removes perspiration from the area immediately surrounding the foot. In some articles of athletic footwear, the various layers may be joined with an adhesive, and stitching may be utilized to join elements within a single layer or to reinforce specific areas of the upper. Although the materials selected for the upper vary significantly, textile materials often form at least a portion of the exterior layer and interior layer. A textile may be defined as any manufacture from fibers, filaments, or yarns characterized by flexibility, fineness, and a high ratio of length to thickness. Textiles generally fall into two categories. The first category includes textiles produced directly from webs of filaments or fibers by randomly interlocking to construct non-woven fabrics and felts. The second category includes textiles formed through a mechanical manipulation of yarn, thereby producing a woven fabric, for example. Yarn is the raw material utilized to form textiles in the second category. In general, yarn is defined as an assembly having a substantial length and relatively small cross-section that is formed of at least one filament or a plurality of fibers. Fibers have a relatively short length and require spinning or twisting processes to produce a yarn of suitable length for use in textiles. Common examples of fibers are cotton and wool. Filaments, however, have an indefinite length and may merely be combined with other filaments to produce a yarn suitable for use in textiles. Modern filaments include a plurality of synthetic materials such as rayon, nylon, polyester, and polyacrylic, with silk being the primary, naturally-occurring exception. Yarn may be formed of a single filament, which is conventionally referred to as a monofilament yarn, or a plurality of individual filaments grouped together. Yarn may also include separate filaments formed of different materials, or the yarn may include filaments that are each formed of two or more different materials. Similar concepts also apply to yarns formed from fibers. Accordingly, yarns may have a variety of configurations that generally conform to the definition provided above. The various techniques for mechanically manipulating yarn into a textile include interweaving, intertwining and twisting, and interlooping. Interweaving is the intersection of two yarns that cross and interweave at right angles to each other. The yarns utilized in interweaving are conventionally referred to as warp and weft. Intertwining and twisting encompasses procedures such as braiding and knotting where yarns intertwine with each other to form a textile. Interlooping involves the formation of a plurality of columns of intermeshed loops, with knitting being the most common method of interlooping. The textiles utilized in footwear uppers generally provide a lightweight, air-permeable structure that is flexible and comfortably receives the foot. In order to impart other properties to the footwear, including durability and stretch-resistance, additional materials are commonly combined with the textile, including leather, synthetic leather, or rubber, for example. With regard to durability, U.S. Pat. No. 4,447,967 to Zaino discloses an upper formed of a textile material that has a polymer material injected into specific zones to reinforce the zones against abrasion or other forms of wear. Regarding stretch resistance, U.S. Pat. No. 4,813,158 to Brown and U.S. Pat. No. 4,756,098 to Boggia both disclose a substantially inextensible material that is secured to the upper, thereby limiting the degree of stretch in specific portions of the upper. From the perspective of manufacturing, utilizing multiple materials to impart different properties to an article of footwear may be an inefficient practice. For example, the various materials utilized in a conventional upper are not generally obtained from a single supplier. Accordingly, a manufacturing facility must coordinate the receipt of specific quantities of materials with multiple suppliers that may have distinct business practices or may be located in different regions or countries. The various materials may also require additional machinery or different assembly line techniques to cut or otherwise prepare the material for incorporation into the footwear. In addition, incorporating separate materials into an upper may involve a plurality of distinct manufacturing steps requiring multiple individuals. Employing multiple materials, in addition to textiles, may also detract from the breathability of footwear. Leather, synthetic leather, or rubber, for example, are not generally permeable to air. Accordingly, positioning leather, synthetic leather, or rubber on the exterior of the upper may inhibit air flow through the upper, thereby increasing the amount of perspiration, water vapor, and heat trapped within the upper and around the foot. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention is an upper for an article of footwear, the upper incorporating a textile element formed with a knitting machine, for example. In one aspect of the invention, the textile element has edges that are joined together to define at least a portion of a void for receiving a foot. In another aspect of the invention, the textile element has a first area and a second area of unitary construction. The first area is formed of a first stitch configuration, and the second area is formed of a second stitch configuration that is different from the first stitch configuration to impart varying textures to a surface of the textile element. The knitting machine may have a configuration that forms the textile element through either warp knitting or weft knitting. Another aspect of the invention involves a method of manufacturing an article of footwear. The method includes a step of mechanically-manipulating a yarn with a circular knitting machine, for example, to form a cylindrical textile structure. In addition, the method involves removing at least one textile element from the textile structure, and incorporating the textile element into an upper of the article of footwear. In another aspect of the invention, an article of footwear has an upper and a sole structure secured to the upper. The upper incorporates a textile element formed with a knitting machine. The textile element is removed from a textile structure that includes an outline of the textile element, and the textile element has edges that are joined together to define at least a portion of a void for receiving a foot. The advantages and features of novelty characterizing the present invention are pointed out with particularity in the appended claims. To gain an improved understanding of the advantages and features of novelty, however, reference may be made to the following descriptive matter and accompanying drawings that describe and illustrate various embodiments and concepts related to the invention. | 20040303 | 20080325 | 20050908 | 94490.0 | 2 | BAYS, MARIE D | ARTICLE OF FOOTWEAR HAVING A TEXTILE UPPER | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,791,312 | ACCEPTED | Intelligent PCI bridging | A bridging device has at least two ports. The first port allows the device to communicate with devices on an expansion bus and at least one other port to allow the bridge to communicate with a system memory on a system bus or other devices on another expansion bus. The device is capable of identifying at least two regions in memory, a descriptor region and a data region. A descriptor provides information about segments of data in the data region. The bridge may detect descriptors read from the memory, extract information related to data associated with those descriptors and use this information to perform prefetching of data from the system memory. | 1. A device, comprising: a first port to allow the device to communicate with other devices on an expansion bus; a second port to allow the device to communicate with devices on a second bus; a memory to store data; and a processing element to: receive a read request from an expansion device to a predetermined area of system memory; transmit read request to the system memory; receive descriptor data from the system memory; parse the descriptor data from the system memory to determine a data size; prefetch data of the data size from the system memory. 2. The device of claim 1, the memory further comprising a hash table in which to store packet addresses and lengths parsed from the descriptor data. 3. The device of claim 1, the second bus further comprising a system bus. 4. The device of claim 1, the second bus further comprising an expansion bus. 5. The device of claim 1, the device further comprising a network device. 6. The device of claim 1, the device further comprising an application specific integrated circuit. 7. The device of claim 1, the expansion device further comprising a network interface card. 8. A method of processing bus transactions, comprising: receiving a read request from an expansion device for a predetermined area of a system memory; transmitting the read request to the system memory; receiving descriptor data from the system memory; parsing the descriptor data to identify a data size; prefetching data having the data size from the system memory. 9. The method of claim 8, the method further comprising storing a data size and data address derived from the descriptor data in a hash table. 10. The method of claim 8, prefetching data further comprising: receiving a read request from the expansion device; identifying the address for the read as not belonging to a preconfigured area of system memory; accessing the transmit size from the descriptor data found in a hash table; issuing a read request to the system memory, wherein the read request has a request size based upon the transmit size; and transmitting data received in response to the read request to the system memory to the expansion device. 11. The method of claim 8, the method further comprising disconnecting from the system memory once the data is received from the system memory. 12. The method of claim 8, the method further comprising storing any prefetched data remaining for a read request if the expansion device disconnects. 13. The method of claim 10, accessing the transmit size further comprising accessing a hash table stored within which are the descriptor data, including packet address and length. 14. The method of claim 8, the method further comprising discarding any prefetched data not transmitted to expansion devices after a programmable amount of time. 15. The method of claim 9, the method further comprising: determining that the memory to store descriptors is full; and discarding an oldest descriptor entry. 16. A device, comprising: a means for allowing the device to communicate with other devices on an expansion bus; a means for allowing the device to communicate with devices on a second bus; a means for storing data; and a means for: receiving a read request from an expansion device to a predetermined area of system memory; transmitting read request to the system memory; receiving descriptor data from the system memory; parsing the descriptor data from the system memory to determine a data size; prefetching data of the data size from the system memory. 17. The device of claim 16, the means for storing further comprising a hash table in which to store packet addresses and lengths parsed from the descriptor data. 18. The device of claim 16, the device further comprising a network device. 19. The device of claim 16, the device further comprising an application specific integrated circuit. 20. The device of claim 16, the expansion device further comprising a network interface card. 21. An article of machine-readable code containing instructions that, when executed, cause the machine to: receive a read request from an expansion device for a predetermined area of a system memory; transmit the read request to the system memory; receive descriptor data from the system memory; parse the descriptor data to identify a data size; and prefetch data having the data size from the system memory. 22. The article of claim 21, the instructions further causing the machine to store the descriptor data in a local memory. 23. The article of claim 21, the instructions causing the machine to prefetch data further causing the machine to: receive a read request from the expansion device; access the transmit size from the descriptor data; issue a read request to the system memory, wherein the read request has a request size based upon the transmit size; and data received in response to the read request to the system memory to the expansion device. 24. The article of claim 21, the instructions further causing the machine to disconnect from the system memory once the data is received from the system memory. 25. The article of claim 21, the instructions further causing the machine to store any prefetched data remaining for a read request if the expansion device disconnects. 26. The article of claim 23, the instructions causing the machine to access the transmit size further causing the machine to access a hash table stored within which are the descriptor data, including descriptors, packet length and addresses, for each set of data. 27. The article of claim. 21, the instructions further causing the machine to discard any prefetched data not transmitted to expansion devices after a programmable amount of time. 28. The article of claim 21, the instructions further causing the machine to: determine that the memory to store descriptors is full; and discard an oldest descriptor entry. | BACKGROUND Many computer systems rely upon expansion busses to add functionality to the overall system. Generally, the added functionality takes the form of small printed circuit boards or other types of ‘cards’ that have on them the necessary components to allow the main processor to communicate with other devices. For example, video cards, audio cards, and network interface cards all provide added functionality to the system. The cards may communicate over an expansion bus, rather than being included on the main system bus. Expansion busses are generally one of two types, an ISA (Industry Standard Architecture) bus or a PCI (Peripheral Component Interconnect) bus. The ISA standard was used initially, but became a bottleneck as processor speeds increased. Typically, most computer systems now employ PCI busses, or busses similar to PCI-X (PCI eXtended). The device that connects the PCI bus to the main system bus is usually referred to as a PCI bridge. Expansion cards communicate with the CPU across the expansion bus. When the CPU needs an expansion device, such as a network interface card, to transmit data, it sets up a transmit ring in the memory to direct the device to the data to be transmitted by writing data descriptors to the transmit ring. The CPU then writes to a device control register set up in the system memory for the expansion device that will transmit the data. When the CPU wants to notify the device of its pending task, it will do so through the PCI bridge. The device then fetches one or more of the descriptors in a single PCI transaction (PCI burst) and then generally one packet at a time until the entire data to be transmitted is fetched. The device then transmits the data as requested by the CPU. PCI bridges may ‘read ahead’ of a transaction, or ‘prefetch’ data from the system memory with the idea being that having the data available to the device at the PCI bridge, rather than in the system memory, would speed the process. Unfortunately, the bridge does not have a good estimate of how much data to prefetch. Bridges may end up prefetching too much data and having to discard the data. Prefetching of the data occupies the bus and the bridge, and wasting any data prefetched reduces the overall system efficiency. This can lead to a high load on the PCI bus and the device, as well as slowing down the speed of transmission through the interface. It may also place a high load on the system memory, which in turn can slow down the effective speed of the CPU. This problem is compounded when another expansion bus is added to the system. When multiple busses exist in a system, there may be PCI bridges that bridge between the busses. These types of bridges are often referred to a PCI-to-PCI bridges, or P2P bridges. For ease of discussion, the term PCI bridge will be used to refer to both PCI and P2P bridges. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention may be best understood by reading the disclosure with reference to the drawings, wherein: FIG. 1 shows an example of a system architecture employing a bridge. FIG. 2 shows a simplified block diagram of a system employing a bridge during an expansion bus transaction cycle. FIG. 3 shows a flow chart of an embodiment of a method for processing an expansion bus transaction. FIG. 4 shows a more detailed flow chart of an embodiment of a method to prefetch data. DETAILED DESCRIPTION OF THE EMBODIMENTS FIG. 1 shows an embodiment of a system using an expansion bus. Devices, such as 18, reside on the expansion bus to add further functions and features to the system. The bridge device 14 provides communications between the system central processing unit 10, and device on the expansion bus 17. A bridge may reside on both the expansion bus and the local system bus 15, or it may reside between two expansion busses. The bridge may be a digital signal processor, general-purpose processor, or an application specific integrated circuit (ASIC), as examples. All of these, as well as other examples, will be referred to here as ‘processing elements.’ In either case, the bridge will have a port 144 to allow it to communicate on the expansion bus 17, and another port 142 to allow it to communicate on the system bus 15 or on another expansion bus, not shown. In one embodiment the system is a network device that employs the expansion device 18 as a network interface card. The central processing unit may have data it wishes to transmit across a network. This transmission operation may be the subject of a transaction between the CPU 10 and the device 18. In general, in order to assist with the transaction, the bridge may institute a prefetching process to bring the data closer to the expansion device more quickly. Currently, however, the prefetching process relies on a prediction of how much data is needed, as there is no current means to communicate how much data is required for a transaction to the bridge devices. This results in adaptations of the prefetching process to overcome this lack of knowledge. One such process, set out in U.S. patent application Ser. No. 10/742,185, (attorney docket no. 2705-306), uses a smart discard approach. The smart discard approach is necessary because the bridge may prefetch data into the bridge and then have it become stale. Stale data is that data that does not reflect changes to the data made in the system memory. Stale data arises in part because the bridge does not know how much data to prefetch. A prefetch is generally the result of a read transaction from an expansion device. An example of a transaction is shown in FIG. 2. It must be noted that this diagram has been simplified for ease of discussion, and any ordering is merely for the same reason. The embodiments of the invention apply to other sequences as well. The CPU 10 is part of the system block that would include the system memory 12. The CPU 10 writes a series of descriptor blocks into a predetermined region of memory, such as region 120 of FIG. 1. These descriptor blocks describe the data to be transmitted, such as the addresses and size of each portion of data to be transmitted. The CPU then writes to the expansion device, requesting that the expansion device transmit the data across the network. The bridge 14 then passes the write on to the expansion device 18, in this embodiment a network interface card, such as an Ethernet or other protocol interface card. The expansion device then issues a read request to fetch the descriptor blocks. The bridge passes this request onto the system, but also notes that the bridge should analyze the response from that portion of the memory. The bridge has knowledge of which portions of memory are used for descriptor blocks, so when the read request for addresses within that portion of memory passes through the bridge, the bridge identifies the request as one for which there may be a prefetch process needed. The knowledge about the descriptor blocks used by a particular expansion device would typically be configured into the bridge when the device initializes. The software that allows the device to communicate with the outside world, the device driver, would configure the bridge with the information that would allow the bridge to recognize a read request for the descriptor blocks. The information may be the descriptor address space, offset of the packet length and the buffer address and descriptor size, and the ending address. Essentially, the necessary information is where the descriptors reside, and where in a descriptor block the bridge can find the length of the data to be transmitted, the length of the descriptor and the address of the particular packet to be transmitted. When the descriptor blocks are read from system memory and pass through the bridge, the bridge would transmit them to the expansion device. In addition, the bridge parses the descriptor to locate the size of the packet to be transmitted, referred to here as the packet length or the transmit size, the location of the packet data, or the address of the data to be transmitted. This data that informs the bridge of the location and size of the data to be operated upon by the device will be referred to here as the descriptor data. The bridge then stores the descriptor data in a table or other local memory on the bridge. Storage in the table will probably involve storage in a hash table. A hash table uses shorter addresses, typically that last byte or two bytes of a full address. This allows for faster indexing of the data by the bridge to locate the desired data. If multiple descriptors are fetched, all the descriptor addresses are optimized and stored for faster access. The expansion device, having received its descriptor blocks, then issues a read request for the data. The bridge now responds to that request by searching the hash table for the corresponding descriptor data using the address of the data in the read request as the key and determining the transmit size, then fetching the data requested as well as prefetching all of the necessary data for the expansion device. The bridge may prefetch the data based upon a read request or even before the read request. For example, assume the packet length is 128 bytes and assume the device can only read 32 bytes at a time, which corresponds to “burst length” in PCI specification. When the device makes the request to read the first 32 bytes, the bridge can prefetch the entire 128 bytes. The bridge knows from the hash table the complete size of the packet. Requests for the remaining 3 sets of 32 bytes of the packet from the device can be delivered by the bridge without going to the system memory as it as already prefetched the complete packet of 128 bytes. The bridge could start prefetching before the first request, but this scheme will be a little more difficult to manage and the bridge will have to be more intelligent. Both schemes are possible and are included in the scope of this invention Allowing the bridge to have the knowledge needed to prefetch the data needed, not more data which results in data discards, and not less data, which requires more reads to retrieve the needed data, increases the efficiency of the system. An embodiment of the process at the bridge is shown in flowchart form in FIG. 3. At 20, the bridge receives the read request from the expansion device. This is the read request triggered by the CPU write to the expansion device. At 22 the read request is issued to the portion of system memory predetermined to have the descriptor addresses. At 24, the descriptor blocks including the descriptor data are received at the bridge. The bridge parses the descriptor data to identify the size of the data transmission at 26. The descriptor data is then stored in the hash table memory at 28. If the memory is full at 36, which is unlikely but could happen on a high volume, multi-channel device, the oldest descriptor is discarded and the space reused for the new descriptor at 38. Another advantage of this process is that the table in which the descriptor data is stored only has to be accessed once. It will then be freed up for other devices or processes to access it. In an alternative to the discarding of the oldest entry, the bridge may track the status of the data. The bridge may be able to determine if the device has consumed all of the data associated with a particular descriptor. If the data has been consumed, it can either be marked as ‘used’ data, or flushed. After fetching the descriptor, the expansion device tries to read the packet from the system memory through the bridge in order to transmit it out at 30. The bridge scans the address to see if it falls in the descriptor address space at 31. If it does, the process returns to 22. Otherwise, the bridge scans the hash table for that address. If no match is found in the hash table, then the bridge behaves like a standard bridge and prefetches data based on cacheline size and the PCI command. If a match is found, the bridge knows that the device is trying to access a packet for transmission. From the hash table the bridge knows the packet size and prefetches the whole packet. At 32, the bridge begins prefetching the data from the system memory. The bridge knowing the transmit size has several benefits. Once the bridge has all of the data it needs for a particular prefetch process, the bridge can disconnect from the system bus at 34, or the expansion bus on the system bus side of the bridge, and remain connected to the expansion bus upon which the expansion device resides. This decreases the load on the system, or system-side bus. Currently, if a bridge close to the CPU breaks a transaction before the complete packet is transferred, the device has to reinitiate a request for the remaining data. In the embodiments of the invention, the bridge knows exactly how much data in which the device is interested, and can prefetch the remaining data without a request from the device shown at 39. When the device reconnects and reinitiates the request, the bridge can handle the request locally, avoiding the overhead and delay involved in going back to the CPU. As mentioned above, the prefetching of the data may have several parts to the process. When the read request comes into the bridge, the bridge accesses the descriptor data from the table and determines the transmit data size at 40 in FIG. 4. Also as mentioned above, this information may be in the form of an offset length into the descriptor data at which the packet length is located. At 42 a read request for a particular size is issued to the system memory. In PCI systems, the read request may be a memory read (MR), a memory read line (MRL) or a memory read multiple line (MRM). An MR is typically 4 bytes of data, also the typical length of the descriptor blocks, and an MRL is for a cache line size, where the cache line size is configured when the bridge is initialized. An MRM is for some multiple of the cache line size. When the data of whichever size arrives back at the bridge, the data is then transmitted to the expansion device at 44. In this manner, the expansion device receives the data it requires, such as that to be transmitted across the network, with minimal overhead on the system bus. In addition, the data is acquired with little waste in the prefetching process. The prefetching process reduces the load on the system bus. The embodiments of a prefetching process as set out here avoid the waste and inefficiency that can come with some prefetching processes as discussed above. Thus, although there has been described to this point a particular embodiment for a method and apparatus for improving efficiency in systems using expansion busses and bridges, it is not intended that such specific references be considered as limitations upon the scope of this invention except in-so-far as set forth in the following claims. | <SOH> BACKGROUND <EOH>Many computer systems rely upon expansion busses to add functionality to the overall system. Generally, the added functionality takes the form of small printed circuit boards or other types of ‘cards’ that have on them the necessary components to allow the main processor to communicate with other devices. For example, video cards, audio cards, and network interface cards all provide added functionality to the system. The cards may communicate over an expansion bus, rather than being included on the main system bus. Expansion busses are generally one of two types, an ISA (Industry Standard Architecture) bus or a PCI (Peripheral Component Interconnect) bus. The ISA standard was used initially, but became a bottleneck as processor speeds increased. Typically, most computer systems now employ PCI busses, or busses similar to PCI-X (PCI eXtended). The device that connects the PCI bus to the main system bus is usually referred to as a PCI bridge. Expansion cards communicate with the CPU across the expansion bus. When the CPU needs an expansion device, such as a network interface card, to transmit data, it sets up a transmit ring in the memory to direct the device to the data to be transmitted by writing data descriptors to the transmit ring. The CPU then writes to a device control register set up in the system memory for the expansion device that will transmit the data. When the CPU wants to notify the device of its pending task, it will do so through the PCI bridge. The device then fetches one or more of the descriptors in a single PCI transaction (PCI burst) and then generally one packet at a time until the entire data to be transmitted is fetched. The device then transmits the data as requested by the CPU. PCI bridges may ‘read ahead’ of a transaction, or ‘prefetch’ data from the system memory with the idea being that having the data available to the device at the PCI bridge, rather than in the system memory, would speed the process. Unfortunately, the bridge does not have a good estimate of how much data to prefetch. Bridges may end up prefetching too much data and having to discard the data. Prefetching of the data occupies the bus and the bridge, and wasting any data prefetched reduces the overall system efficiency. This can lead to a high load on the PCI bus and the device, as well as slowing down the speed of transmission through the interface. It may also place a high load on the system memory, which in turn can slow down the effective speed of the CPU. This problem is compounded when another expansion bus is added to the system. When multiple busses exist in a system, there may be PCI bridges that bridge between the busses. These types of bridges are often referred to a PCI-to-PCI bridges, or P2P bridges. For ease of discussion, the term PCI bridge will be used to refer to both PCI and P2P bridges. | <SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>Embodiments of the invention may be best understood by reading the disclosure with reference to the drawings, wherein: FIG. 1 shows an example of a system architecture employing a bridge. FIG. 2 shows a simplified block diagram of a system employing a bridge during an expansion bus transaction cycle. FIG. 3 shows a flow chart of an embodiment of a method for processing an expansion bus transaction. FIG. 4 shows a more detailed flow chart of an embodiment of a method to prefetch data. detailed-description description="Detailed Description" end="lead"? | 20040301 | 20080909 | 20050901 | 98213.0 | 0 | ZAMAN, FAISAL M | INTELLIGENT PCI BRIDGING CONSISTING OF PREFETCHING DATA BASED UPON DESCRIPTOR DATA | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,791,437 | ACCEPTED | Dynamic memory word line driver scheme | A circuit which accurately controls the word line (pass transistor gate) driving voltage to a voltage which is both controlled and is not significantly greater than is needed to drive the word line. The elements of the present invention eliminate the need for a double-boot-strapping circuit, and ensure that no voltages exceed that necessary to fully turn on a memory cell access transistor. Accordingly, voltages in excess of that which would reduce reliability are avoided, and accurate driving voltages are obtained. A DRAM is comprised of word lines, memory cells having enable inputs connected to the word lines, apparatus for receiving word line selecting signals at first logic levels Vss and Vdd, and for providing a select signal at levels Vss and Vdd, a high voltage supply source Vpp which is higher in voltage than Vdd, circuit for translating the select signals at levels Vss and Vdd to levels Vss and Vpp and for applying it directly to the word lines for application to the enable inputs whereby an above Vdd voltage level word line is achieved without the use of double boot-strap circuits. | 1. A random access memory comprising: a controlled high voltage supply; word lines; memory cells, each comprising a charge storage capacitor and a pass transistor for storing a logic level on the storage capacitor, the pass transistor having an enable input connected to a word line; word line selection circuits, each selection circuit comprising: a pair of cross-coupled transistors coupled drain-to-gate at respective control nodes and having respective sources coupled to the controlled high voltage supply; a first pull-down transistor coupled to one of the control nodes and gated by a word line select signal; and a second pull-down transistor connected in parallel with the first pull-down transistor to said one of the control nodes, the gate of the second pull-down transistor being coupled to the other control node. | RELATED APPLICATIONS This application is a Continuation of application Ser. No. 10/463,194, filed on Jun. 17, 2003, which is a Continuation of application Ser. No. 09/919,752, filed on Jul. 31, 2001, now U.S. Pat. No. 6,603,703, which issued on Aug. 5, 2003, which is a Continuation of application Ser. No. 09/548,879, filed on Apr. 13, 2000, now U.S. Pat. No. 6,278,640, which issued on Aug. 21, 2001, which is a Continuation of application Ser. No. 09/123,112, filed on Jul. 27, 1998, now U.S. Pat. No. 6,061,277, which issued on May 9, 2000, which is a Continuation of application Ser. No. 08/705,534, filed on Aug. 29, 1996, now abandoned, which is a Continuation of application Ser. No. 08/611,558, filed on Mar. 6, 1996, now U.S. Pat. No. 5,751,643, which issued on May 12, 1998, which is a Continuation-in-Part of application Ser. No. 08/515,904, filed on Aug. 16, 1995, now U.S. Pat. No. 5,822,253, which issued on Oct. 13, 1998, which is a Continuation of application Ser. No. 08/205,776, filed on Mar. 3, 1994, now abandoned, which is a File Wrapper Continuation of application Ser. No. 08/031,898, filed on Mar. 16, 1993, now abandoned, which is a Continuation of application Ser. No. 07/680,746, filed on Apr. 5, 1991, now U.S. Pat. No. 5,214,602, which issued on May 25, 1993, which relates to Japanese Application No. 9107165, filed on Apr. 5, 1991 and United Kingdom Application No. 9007790.0, filed on Apr. 6, 1990. The entire teachings of the above applications are incorporated herein by reference. FIELD OF THE INVENTION This invention relates to CMOS dynamic random access memories (DRAMs), and particularly to word line drivers. BACKGROUND TO THE INVENTION Dynamic random access memories are generally formed of a matrix of bit lines and word lines with memory cells located adjacent the intersections of the bit lines and word lines. The memory cells are enabled to provide the stored bits to the bit lines or to permit a write operation by signals carried on the word lines. Each memory cell is typically formed of a bit store capacitor connected to a reference voltage and through the source-drain circuit of an “access” field effect transistor to an associated bit line. The gate of the field effect transistor is connected to the word line. A logic signal carried by the word line enables the transistor, thus allowing charge to flow through the source-drain circuit of the transistor to the capacitor, or allowing charge stored on the capacitor to pass through the source-drain circuit of the access transistor to the bit line. In order for the logic level Vdd potential from the bit line to be stored on the capacitor, the word line must be driven to a voltage above Vdd+Vtn, where Vtn is the threshold voltage or the access transistor including the effects of back bias. During the early days of DRAM design, NMOS type FETs, that is, N-channel devices were used exclusively. In order to pass a Vdd+Vtn level signal to the selected word line, the gate of the pass transistor had to be driven to at least Vdd+2Vtn. Furthermore, to allow sufficient drive to achieve a voltage greater than Vdd+Vtn on the word line within a reasonable length of time in order to facilitate a relatively fast memory, the gate of the pass transistor is driven to a significantly higher voltage. In such devices, the word line driving signal utilized capacitors in a well-known double-boot strap circuit. In the above circuit, the boot strapping voltage circuit is designed to exceed the voltage Vdd+2Vtn, in order to ensure that temperature, power supply, and process variations would never allow the pass transistor driving voltage to fall below Vdd+2Vtn. However, it has been found that in small geometry VLSI memories, the high voltages provided by the boot-strap circuits can exceed the tolerable voltages in the memory, thus adversely affecting reliability. SUMMARY OF THE INVENTION The present invention is a circuit which accurately controls the word line (pass transistor gate) driving voltage to a voltage which is both controlled and is not significantly greater than is needed to drive the word line. The elements of the present invention eliminate the need for a double-boot-strapping circuit, and ensure that no voltages exceed that necessary to fully turn on a memory cell access transistor. Accordingly, voltages in excess of that which would reduce reliability are avoided, and accurate driving voltages are obtained. According to an embodiment of the invention a dynamic random access memory (DRAM) is comprised of word lines, memory cells having enable inputs connected to the word lines, apparatus for receiving word line selecting signals at first logic levels Vss and Vdd, and for providing a select signal at levels Vss and Vdd, a high voltage supply source Vpp which is higher in voltage than Vdd, a circuit for translating the select signals at levels Vss and Vdd to levels Vss and Vpp and for applying it directly to the word lines for application to the enable inputs whereby an above Vdd voltage level word line is achieved without the use of double boot-strap circuits. According to another embodiment, a dynamic random access memory (DRAM) is comprised of bit-lines and word lines, memory cells connected to the bit lines and word lines, each memory cell being comprised of an access field effect transistor (FET) having its source-drain circuit connected between a bit line and a bit charge storage capacitor, the access field effect transistor having a gate connected to a corresponding word line; a high supply voltage source Vpp; a circuit or selecting the word line and a circuit having an input driven by the selecting apparatus for applying the Vpp supply voltage to the word line. BRIEF INTRODUCTION TO THE DRAWINGS A better understanding of the invention will be obtained by reference to the detailed description below, in conjunction with the following drawings, in which; FIG. 1 is a schematic diagram of the invention. DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION Turning now to FIG. 1, a CMOS DRAM is comprised of word lines, represented by word line 1 and bit lines, represented by bit lines 2A, 2B, etc. Access transistors 3A, 3B have their gates connected to the word line; their sources are connected to bit charge storing capacitors 4A, 4B, etc. which are also connected to ground. The drains of access transistors 3A, 3B, etc. are connected to the bit lines 2A, 2B, etc. With the application of a logic signal of Vdd+Vtn to the gate of transistor 3A, 3B, etc., Vdd level on the bit line 2A, 2B, etc. is fully transferred to the associated capacitor 4A, 4B, etc. during the writing cycle. In the prior art it was necessary to apply a voltage greater than Vdd+2Vtn to the gate of an N-channel pass transistor in order to ensure that a voltage in excess of Vdd+Vtn would be available at the gates of transistors 3A, 3B, etc. The combination of a bit storing charge capacitor, e.g. 4A, with an associated access transistor, e.g. 3A, forms a memory cell in prior art DRAMs. The word line is selected by means of addresses Aij applied to the inputs of a NAND gate 5. In the prior art a double boot-strap circuit was connected between the output NAND gate 5 and the word line. In accordance with the present invention a voltage Vpp which is higher than the logic level Vdd+Vtn is utilized. A level shifter 6 is formed of a pair of cross coupled P-channel transistors 7A and 7B. The sources of transistors 7A and 7B are connected to the voltage source Vpp. The level shifter defines a first and a second control node, respectively 8A and 8B. The output of NAND gate 5 is connected through an inverter 9 to the gate of an N-channel FET 10. FET 10 has its source connected to ground and its drain connected to control node 8A. The output of NAND gate 5 is connected to the gate of an N-channel FET 11, which has its source connected to ground and its drain connected to control node 8B. A third N-channel FET 12 has its source connected to ground, its drain connected to the drain of transistor 11, and its gate to control node 8A. Control node 8A (or a buffered version of control node 8A) is applied to the gate of pass transistor 14A and pull down transistor 3A. The source of pass transistor 14A is connected to Vpp or to a secondary decoder output which provides a Vss or Vpp level output; its drain to word line 1. The source of pull down transistor 13A is connected to ground; the drain is connected to word line 1. In operation, assume that the word line 1 has not been selected. At least one address input of NAND gate 5 is low, causing the output of NAND gate 5 to be high, and the output of inverter 9 to be low. Transistor 11 is enabled, pulling node 8B to ground. Transistor 10 is disabled, allowing transistor 7A to charge node 8A to Vpp. Transistor 12 is thus enabled ensuing that node 8A is pulled high. The Vpp level node 8A disables the pass device 14A and enables pull down transistor 13A so that word line 1 is held at ground. Thus transistors 3A and 3B are not enabled and are not conducting. The charge stored on capacitors 4A and 4B are thus maintained, and are not read to the bit lines. Assume now that word line 1 is selected. Logic high level address signals at the voltage level Vdd are applied to the inputs of NAND gate 5. The output of the NAND gate thus goes to low level. The output of inverter 9 changes to high level, transistor 10 is enabled, and pulls node 8A toward ground. This causes transistor 7B to be enabled, and pull node 8B toward Vpp. This causes transistor 7A to be disabled so that node 8A is pulled to ground, disabling transistor 12 and allowing transistor 7B to charge node 8B to Vpp. The ground level voltage on node 8A disables pull down transistor 13A, and enables the pass transistor 14A so that the word line 1 is driven to a Vpp level. The voltage on the word line is thus controlled, and depending on whether the word line is selected or not, it switches between ground and Vpp. With the voltage Vpp being controlled to Vdd+Vtn, the voltage at the gates of the cell access transistors 3A and 3B is certain to be Vdd+Vtn. However the voltage Vpp is selected to be less than a voltage that would be in excess of that which would deteriorate reliability of the DRAM. A person understanding this invention may now conceive of alternative structures and embodiments or variations of the above. All of those which all within the scope of the claims appended hereto are considered to be part of the present invention. | <SOH> BACKGROUND TO THE INVENTION <EOH>Dynamic random access memories are generally formed of a matrix of bit lines and word lines with memory cells located adjacent the intersections of the bit lines and word lines. The memory cells are enabled to provide the stored bits to the bit lines or to permit a write operation by signals carried on the word lines. Each memory cell is typically formed of a bit store capacitor connected to a reference voltage and through the source-drain circuit of an “access” field effect transistor to an associated bit line. The gate of the field effect transistor is connected to the word line. A logic signal carried by the word line enables the transistor, thus allowing charge to flow through the source-drain circuit of the transistor to the capacitor, or allowing charge stored on the capacitor to pass through the source-drain circuit of the access transistor to the bit line. In order for the logic level V dd potential from the bit line to be stored on the capacitor, the word line must be driven to a voltage above V dd +V tn , where V tn is the threshold voltage or the access transistor including the effects of back bias. During the early days of DRAM design, NMOS type FETs, that is, N-channel devices were used exclusively. In order to pass a V dd +V tn level signal to the selected word line, the gate of the pass transistor had to be driven to at least V dd +2V tn . Furthermore, to allow sufficient drive to achieve a voltage greater than V dd +V tn on the word line within a reasonable length of time in order to facilitate a relatively fast memory, the gate of the pass transistor is driven to a significantly higher voltage. In such devices, the word line driving signal utilized capacitors in a well-known double-boot strap circuit. In the above circuit, the boot strapping voltage circuit is designed to exceed the voltage V dd +2V tn , in order to ensure that temperature, power supply, and process variations would never allow the pass transistor driving voltage to fall below V dd +2V tn . However, it has been found that in small geometry VLSI memories, the high voltages provided by the boot-strap circuits can exceed the tolerable voltages in the memory, thus adversely affecting reliability. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention is a circuit which accurately controls the word line (pass transistor gate) driving voltage to a voltage which is both controlled and is not significantly greater than is needed to drive the word line. The elements of the present invention eliminate the need for a double-boot-strapping circuit, and ensure that no voltages exceed that necessary to fully turn on a memory cell access transistor. Accordingly, voltages in excess of that which would reduce reliability are avoided, and accurate driving voltages are obtained. According to an embodiment of the invention a dynamic random access memory (DRAM) is comprised of word lines, memory cells having enable inputs connected to the word lines, apparatus for receiving word line selecting signals at first logic levels V ss and V dd , and for providing a select signal at levels V ss and V dd , a high voltage supply source V pp which is higher in voltage than V dd , a circuit for translating the select signals at levels V ss and V dd to levels V ss and V pp and for applying it directly to the word lines for application to the enable inputs whereby an above V dd voltage level word line is achieved without the use of double boot-strap circuits. According to another embodiment, a dynamic random access memory (DRAM) is comprised of bit-lines and word lines, memory cells connected to the bit lines and word lines, each memory cell being comprised of an access field effect transistor (FET) having its source-drain circuit connected between a bit line and a bit charge storage capacitor, the access field effect transistor having a gate connected to a corresponding word line; a high supply voltage source V pp ; a circuit or selecting the word line and a circuit having an input driven by the selecting apparatus for applying the V pp supply voltage to the word line. | 20040302 | 20060502 | 20050127 | 99911.0 | 5 | LUU, PHO M | DYNAMIC MEMORY WORD LINE DRIVER SCHEME | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,791,548 | ACCEPTED | Fruit juicer with increased juice yield | A fruit juicer has a rotating, upwardly-tapering, centrally-disposed, projecting element, for the pressing of a fruit. The element is surrounded by a collector dish, into which a stationary wall of a fixed annular body extends downwards. A device for compressing the fruit pulp, and thus squeezing additional juice out of the pulp, is formed on the wall. On rotating the collector dish with a motor drive the compression device forces the pulp of the fruit downwards in a generally wedge direction. The additional compression device is one or more blades that are fixed to or formed on the inner side of the projecting wall. | 1. A fruit juicer, comprising: a rotatably disposed, upwardly tapering, projecting element for pressing fruit; a collection bin annularly surrounding said element and rigidly connected to said element for rotating with said element in a direction of rotation, said collection bin having an annular surface and openings formed therein for fruit juice to pass through; and at least one blade disposed to squeeze fruit juice out of fruit pulp in said collection bin, said at least one blade being inclined downwardly in the direction of rotation, for compressing the fruit pulp between said blade and said annular surface. 2. The fruit juicer according to claim 1, wherein said element is centrally disposed in said collection bin and said blade is one of at least two blades symmetrically mounted relative to said element. 3. The fruit juicer according to claim 1, wherein the downwards inclined blade extends helically along a part of the periphery of the collection bin. 4. The fruit juicer according to claim 1, which further comprises an annular body surrounding said collection bin, and wherein said blade is disposed on said annular body. 5. The fruit juicer according to claim 4, wherein said collection bin has an outer wall, and said annular body is formed with a wall projecting downwardly into said collection bin and inwardly overlapping said outer wall of said collection bin. 6. The fruit juicer according to claim 5, wherein said at least one blade is attached to said downwardly projecting wall. 7. The fruit juicer according to claim 4, wherein said annular body has an outwardly projecting collar configured to support said annular body on a collector dish. 8. The fruit juicer according to claim 4, wherein said wall of said annular body is a first wall, and said annular body has a second wall projecting downwardly between said outer wall of said collection bin and an outer wall of a collector dish. 9. A juicer, comprising: a rotatably mounted collection bin having a generally cylindrical shape with an outer wall and a bottom, and having a pressing element centrally disposed therein, said pressing element projecting upwardly from said bottom and said bottom having openings formed therein for fruit juice to pass through in a trough formed between said pressing element and said outer wall; at least one stationary blade disposed in said trough between said pressing element and said outer wall and inclined downwardly in a direction of rotation of said collection bin, for squeezing fruit juice out of fruit pulp by compressing the fruit pulp between said blade and said annular surface as said collection bin rotates; and a collection container disposed below said collection bin for collecting the fruit juice emanating from said openings in said bottom. | CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation, under 35 U.S.C. § 120, of copending international application No. PCT/EP02/09401, filed Aug. 22, 2002, which designated the United States; this application also claims the priority, under 35 U.S.C. § 119, of German patent application No. 101 42 246, filed Aug. 29, 2001; the prior applications are herewith incorporated by reference in their entirety. BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a juicer or fruit press that comprises a rotating, upwardly tapering, centrally disposed, projecting element for the pressing of a fruit, and with a collection bin annularly surrounding the element and connected solidly to the latter, with openings for the fruit juice to pass through. German Gebrauchsmuster DE 1 982 544 U1 describes a citrus press, which has a mechanical pressing device arranged downstream of a pressing cone for the fruit pulp loosened from the fruit peel by the pressing cone. The pressing device has a feed screw, disposed underneath the pressing cone on its drive shaft and surrounded by the sieve sleeve of a sieve enclosing the pressing cone. European patent EP 0 362 058 B1 also discloses a fruit press, or fruit juicer. That juicer has an electric drive motor. The motor is mounted inside the housing. It drives a drive-side shaft, on which the fruit press is mounted, via a drive belt and belt pulley. It is a common problem associated with the prior art that a certain amount of usable juice is not pressed from the fruit and that the juice yield is not maximized. SUMMARY OF THE INVENTION It is accordingly an object of the invention to provide a fruit juicer, which overcomes the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and which is further improved such that the juice yield is increased. With the foregoing and other objects in view there is provided, in accordance with the invention, a fruit juicer, comprising: a centrally and rotatably disposed, upwardly tapering, projecting element for pressing fruit; a collection bin annularly surrounding said element and rigidly connected to said element for rotating with said element in a direction of rotation, said collection bin having an annular surface and openings formed therein for fruit juice to pass through; and at least one blade disposed to squeeze fruit juice out of fruit pulp in said collection bin, said at least one blade being inclined downwardly in the direction of rotation, for compressing the fruit pulp between said blade and said annular surface. In other words, the objects of the invention are achieved with a juicer of the type initially mentioned by providing a fixed device for pressing out the fruit juice projecting down into the collection bin. The fruit juice yield is increased by the added squeezing device that presses out the fruit juice. The device remains fixed in place, while the collection bin rotates. By compressing the fruit pulp squeezed by the pressing cone out of the fruit it is possible to prolong the use time of the fruit press, for example to double it, without having to clean it. In a preferred embodiment the fruit press is wherein the means has at least one downwards inclined blade, by means of which the fruit juice can be squeezed out of the fruit flesh present in the collection bin by rotating it. In a preferred variant the means comprises an annular body surrounding the collection bin. The annular body is preferably constructed such that it has a first wall, overlapping an outer wall of the collection bin inwards and projecting down into the collection bin, on which at least one blade is attached. In this way, a simply constructed vessel is created, which surrounds the fruit press. The wall likewise contributes to the fact that no fruit flesh accumulates and sets in the slot projecting into a mantle wall of the collection bin at the outlet for the fruit juice. In a further development of the invention the annular body has an outwards directed collar, with which it bears on a collector dish. An easy-to-handle assembly for a fruit press and a dish arranged under it are created by this particular construction. In another preferred embodiment of the invention the annular body has a second wall, projecting down between the outer wall of the collection bin and a mantle wall of the collector dish. Other features which are considered as characteristic for the invention are set forth in the appended claims. Although the invention is illustrated and described herein as embodied in a fruit juicer, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective sectional view of a fruit juicer; and FIG. 2 is a perspective sectional view of an annular body surrounding the fruit press. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown a fruit juicer or fruit press 1 with a central pressing element 2. The element 2, substantially has an enveloping shape of a rotation parabola, a hemisphere, a semi-ellipsoid or a cone, and it is enclosed at its base by an annular surface 3. Fruit juice collects in the annular surface 3. Fruit juice is produced by pressing fruit over the element 2. The ring surface 3 is part of a collection bin 4. The fruit juice drips out of this through rib-like slots 5 into a collector dish 6, in which the fruit juice is trapped. The element 2 is designed substantially as a hollow body, in which a hollow shaft 7 to receive a non-illustrated trunnion is arranged centrally for rotatingly driving the fruit press 1, that is, the element 2 and the collection bin 4 surrounding it, which is connected to a drive shaft of a drive motor. The collection bin 4 has a circular outer wall 8, over which a wall 9 of a fixed annular body 10 projects down. Two blades or wings 11 are disposed on the inside of the wall 9. The two blades 11, which are disposed diagonally across one another on the wall 9, are inclined downwards in the direction of rotation of the collection bin, such that fruit pulp, which has been loosened from the fruit to be pressed during the pressing procedure, is compressed more and more in the region between the blades 11 and the annular surface 3. The result is that even more fruit juice is pressed or squeezed out of the fruit pulp or fruit flesh. An added effect of the blades 11 is that the fruit pulp is compressed, such that it does not suck up the fruit juice flowing past in the pressing procedure, and that the fruit press 1 does not have to be removed from the collector dish 6 so often for cleaning. Referring now to FIG. 2, the annular body 10 also has an outwardly projecting collar 12, with which it bears on the collector dish 6, and a ridge wall 13, which projects down between the outer wall 8 of the collection bin 4 and a outer wall 14 of the collector dish 6. The invention thus provides for a fruit press 1 with a rotating, upwardly tapering, centrally disposed, projecting element 2 for pressing a fruit. The element 2 is enclosed by a collector dish 6, into which a wall 9 of a fixed annular body 10 protrudes. On the wall 9 is a means for squeezing the fruit pulp, which presses the fruit pulp downwards by rotating the fruit press 1 by a motor drive in the direction of an arrow P. The means according to the above-described preferred embodiment, is in the form of a blade 11 or a multiplicity of blades 11, attached to the inner side of the wall 9. | <SOH> BACKGROUND OF THE INVENTION <EOH>Field of the Invention The present invention relates to a juicer or fruit press that comprises a rotating, upwardly tapering, centrally disposed, projecting element for the pressing of a fruit, and with a collection bin annularly surrounding the element and connected solidly to the latter, with openings for the fruit juice to pass through. German Gebrauchsmuster DE 1 982 544 U1 describes a citrus press, which has a mechanical pressing device arranged downstream of a pressing cone for the fruit pulp loosened from the fruit peel by the pressing cone. The pressing device has a feed screw, disposed underneath the pressing cone on its drive shaft and surrounded by the sieve sleeve of a sieve enclosing the pressing cone. European patent EP 0 362 058 B1 also discloses a fruit press, or fruit juicer. That juicer has an electric drive motor. The motor is mounted inside the housing. It drives a drive-side shaft, on which the fruit press is mounted, via a drive belt and belt pulley. It is a common problem associated with the prior art that a certain amount of usable juice is not pressed from the fruit and that the juice yield is not maximized. | <SOH> SUMMARY OF THE INVENTION <EOH>It is accordingly an object of the invention to provide a fruit juicer, which overcomes the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and which is further improved such that the juice yield is increased. With the foregoing and other objects in view there is provided, in accordance with the invention, a fruit juicer, comprising: a centrally and rotatably disposed, upwardly tapering, projecting element for pressing fruit; a collection bin annularly surrounding said element and rigidly connected to said element for rotating with said element in a direction of rotation, said collection bin having an annular surface and openings formed therein for fruit juice to pass through; and at least one blade disposed to squeeze fruit juice out of fruit pulp in said collection bin, said at least one blade being inclined downwardly in the direction of rotation, for compressing the fruit pulp between said blade and said annular surface. In other words, the objects of the invention are achieved with a juicer of the type initially mentioned by providing a fixed device for pressing out the fruit juice projecting down into the collection bin. The fruit juice yield is increased by the added squeezing device that presses out the fruit juice. The device remains fixed in place, while the collection bin rotates. By compressing the fruit pulp squeezed by the pressing cone out of the fruit it is possible to prolong the use time of the fruit press, for example to double it, without having to clean it. In a preferred embodiment the fruit press is wherein the means has at least one downwards inclined blade, by means of which the fruit juice can be squeezed out of the fruit flesh present in the collection bin by rotating it. In a preferred variant the means comprises an annular body surrounding the collection bin. The annular body is preferably constructed such that it has a first wall, overlapping an outer wall of the collection bin inwards and projecting down into the collection bin, on which at least one blade is attached. In this way, a simply constructed vessel is created, which surrounds the fruit press. The wall likewise contributes to the fact that no fruit flesh accumulates and sets in the slot projecting into a mantle wall of the collection bin at the outlet for the fruit juice. In a further development of the invention the annular body has an outwards directed collar, with which it bears on a collector dish. An easy-to-handle assembly for a fruit press and a dish arranged under it are created by this particular construction. In another preferred embodiment of the invention the annular body has a second wall, projecting down between the outer wall of the collection bin and a mantle wall of the collector dish. Other features which are considered as characteristic for the invention are set forth in the appended claims. Although the invention is illustrated and described herein as embodied in a fruit juicer, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. | 20040301 | 20050920 | 20050210 | 61615.0 | 0 | SIMONE, TIMOTHY F | FRUIT JUICER WITH INCREASED JUICE YIELD | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,791,759 | ACCEPTED | Method of reducing STI divot formation during semiconductor device fabrication | STI divot formation is eliminated or substantially reduced by employing a very thin nitride polish stop layer, e.g., no thicker than 400 Å. The very thin nitride polish stop layer is retained in place during subsequent masking, implanting and cleaning steps to form dopant regions, and is removed prior to gate oxide and gate electrode formation. | 1. A method of fabricating a semiconductor device, the method comprising: forming a nitride polish stop layer, at a thickness no greater than 400 Å, over a semiconductor substrate; forming an opening in the nitride polish stop layer and a trench in the substrate; filling the trench with insulating material forming an overburden on the nitride polish stop layer; and polishing to form an upper planar surface stopping of the nitride polish stop layer, thereby forming a shallow trench isolation region. 2. The method according to claim 1, comprising forming the nitride polish stop layer at a thickness of 50 Å to 150 Å. 3. The method according to claim 1, comprising polishing to form the upper planar surface while removing no more than 20 Å of the nitride polish stop layer. 4. The method according to claim 1, comprising forming a pad oxide layer on an upper surface of the semiconductor substrate, and forming the nitride polish stop layer on the pad oxide layer. 5. The method according to claim 1, further comprising ion implanting impurities through the nitride polish stop layer to forming impurity regions in the semiconductor substrate adjacent the shallow trench isolation region. 6. The method according to claim 5, further comprising: removing the nitride polish stop layer; forming a gate oxide layer on the semiconductor substrate after removing the nitride polish stop layer; and forming a gate electrode on the gate oxide layer. 7. The method according to claim 6, further comprising etching to remove part of an upper surface of the insulating material filling the trench so that the upper surface of the insulating material is substantially coplanar with the upper surface of the semiconductor substrate before removing the nitride polish stop layer. | FIELD OF THE INVENTION The present invention relates to the fabrication of integrated circuit semiconductor devices. The present invention is particularly applicable to fabricating highly integrated circuit semiconductor devices having high quality shallow trench isolation (STI) without or with substantially reduced divot formation. BACKGROUND ART As miniaturization of elements of an integrated circuit semiconductor device drives the industry, the width and the pitch of an active region have become smaller, thereby rendering the use of traditional LOCOS (local oxidation of silicon) isolation techniques problematic. STI is considered a more viable isolation technique than LOCOS because, by its nature, creates hardly any bird's beak characteristic of LOCOS, thereby achieving reduced conversion differences. Conventional STI fabrication techniques include forming a pad oxide on an upper surface of a semiconductor substrate, forming a nitride, e.g., silicon nitride, polish stop layer thereon, typically having a thickness of greater than 1000 Å, forming an opening in the nitride polish stop layer, anisotropically etching to form a trench in the semiconductor substrate, forming a thermal oxide liner in the trench and then filling the trench with insulating material, such as silicon oxide, forming an overburden on the nitride polish stop layer. Planarization is then implemented, as by conducting chemical mechanical polishing (CMP). During subsequent processing, the nitride layer is removed along with the pad oxide followed by formation of active areas, which typically involve masking, ion implantation, and cleaning steps. During such cleaning steps, the top corners of the field oxide are isotropically removed leaving a void or “divot” in the oxide fill. For example, a conventional STI fabrication technique is illustrated in FIGS. 1 through 4, wherein similar features are denoted by similar reference characters. Adverting to FIG. 1, a pad oxide 11 is formed over an upper surface of a semiconductor substrate 10, and a silicon nitride polish stop layer 12 is formed thereon, typically at a thickness in excess of 1000 Å. A photomask (not shown) is then used to form an opening through the nitride polish stop layer 12, pad oxide 11, and a trench 12 is formed in the semiconductor substrate 10. Subsequently, a thermal oxide liner (not shown) is formed in the trench, an insulating material is deposited and planarization implemented, as by CMP, resulting in the intermediate structure illustrated in FIG. 2, the reference character 20 denoting the oxide fill. Subsequently, the nitride polish stop layer 12 and pad oxide layer 11 are removed and cleaning steps are performed prior to forming active regions. Such cleaning steps result in the formation of divots 30 as illustrated in FIG. 3. The STI divots are problematic in various respects. For example, STI divots are responsible for high field edge leakage, particularly with shallow source/drain junctions. As shown in FIG. 4, silicide regions 41 formed on shallow source/drain regions 40 grow steeply downwards, as illustrated by reference character 42, below the junction depth formed at a latter stage resulting in high leakage and shorting. Segregation of dopants, notably boron, at STI field edges reduces the junction depth. Accordingly, after the junctions are silicided, the silicide 42 penetrating to the substrate causes shorting routes and, hence, large leakage occurrence from the source/drain junctions to a well or substrate. In addition, if the STI edge becomes exposed as a result of divot formation, a parasitic transistor with a low threshold voltage is formed over the area with low impurity concentration causing a kink in the characteristics curve of a transistor. The presence of a kink results in electrical characteristics different from the design electrical characteristics, thereby preventing the fabrication of transistors with uniform characteristics. Accordingly, there exists a need for methodology enabling the fabrication of highly integrated semiconductor devices with highly reliable STI regions without or with substantially reduced divots. DISCLOSURE OF THE INVENTION An advantage of the present invention is a method of manufacturing a semiconductor device comprising highly reliable STI regions with no or substantially reduced divots. Additional advantages and other features of the present invention will be set forth in the description which follows and in part will be apparent to those having ordinary skill in the art upon examination of the following or may be learned from the practice of the present invention. The advantages of the present invention may be realized and obtained as particularly pointed out in the appended claims. According to the present invention, the foregoing and other advantages are achieved in part by a method of manufacturing a semiconductor device, the method comprising: forming a nitride polish stop layer, at a thickness no greater than 400 Å, over a semiconductor substrate; forming an opening in the nitride polish stop layer and a trench in the substrate; filling the opening with insulating material forming an overburden on the nitride polish stop layer; and polishing to form an upper planar surface stopping on the nitride polish stop layer, thereby forming a shallow trench isolation region. Embodiments of the present invention comprise forming a pad oxide on an upper surface of the semiconductor device substrate, forming the nitride polish stop layer, e.g., a silicon nitride polish stop layer, at a thickness of 50 Å to 150 Å, e.g., 100 Å, on the pad oxide layer, filling the opening with dielectric insulating material, such as silicon oxide deposited by chemical vapor deposition, and then implementing chemical mechanical polishing (CMP) to effect planarization stopping on the nitride polish stop layer by removing no more than 20 Å of the upper surface of the nitride polish stop layer. Embodiments of the present invention further include ion planting impurities through the nitride polish stop layer to form impurity regions in the semiconductor substrate adjacent the shallow trench isolation region, etching to remove part of the upper surface of the insulating material filling the trench so that the upper surface of the insulating material in the trench is substantially coplanar with the upper surface of the semiconductor substrate, and then removing the nitride polish stop layer. Subsequently, a gate oxide layer is formed on the substrate and a gate electrode layer is formed thereon, employing conventional techniques. Additional advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein embodiments of the present invention are described, simply by way of illustration of the best mode contemplated for carrying out the present invention. As will be realized, the present invention is capable of other and different embodiments and its several details are capable of modifications in various obvious respects, all without departing from the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 through 4 schematically illustrate sequential phases of a conventional method for forming STI regions. In FIGS. 1 through 4, similar features are denoted by similar reference characters. FIGS. 5 through 11 schematically illustrate sequential phases of a method in accordance with an embodiment of the present invention. In FIGS. 5 through 11, similar features are denoted by similar reference characters. DESCRIPTION OF THE INVENTION The present invention addresses and solves problems attendant upon implementing conventional STI methodology resulting in the formation of divots at the corners of an STI region. Such conventional methodology typically comprises forming a relatively thick nitride polish stop layer, as at a thickness greater than 1000 Å. Such a thick nitride polish stop layer is typically removed immediately following the STI oxide polish, because subsequent steps require ion implanting to form the active areas, and thick nitride films block such ion implantation. Many masking, implanting and cleaning steps are used to form the active regions resulting in the formation of divots at the corners of the STI region. Conventional approaches to this problem seek to minimize these divots as, for example, by optimizing post oxide polish cleans and nitride pull-back prior to STI oxide fill. However, such approaches have not adequately resolved the STI divot problem. In accordance with the present invention, an extremely thin nitride polish stop layer, e.g., silicon nitride, is deposited at a thickness no greater than 400 Å, such as at a thickness of 10 Å to 400 Å. Suitable silicon nitride polish etch stop layer thicknesses are 50 Å to 150 Å, e.g., 100 Å. Advantageously, the thin nitride polish stop layer is not removed immediately after the STI oxide polish. Rather, the thin nitride etch stop layer is retained during subsequent processing comprising masking, ion implanting and cleaning steps to form the active areas. The use of a thin nitride etch stop layer is sufficient to protect the filled trench corners, thereby preventing isotropic attack of the oxide at the STI corners, which would otherwise result in the formation of divots. In addition, since the nitride polish stop layer is thin, ion implantation is not blocked. In fact, the use of a thin nitride polish stop layer presents a more consistent surface for implantation, because a relatively bare silicon surface rapidly forms an inconsistent native oxide; whereas, the nitride surface is considerably more stable. Thus, in accordance with the embodiments of the present invention, the nitride polish stop layer is retained in place up to the formation of the gate oxide, thereby protecting the active silicon area, providing a much more planar surface and preventing or substantially reducing divots. A method in accordance with an embodiment of the present invention is schematically illustrated in FIGS. 5 through 11, wherein similar features are denoted by similar reference characters. Adverting to FIG. 5, a pad oxide, as at a thickness of 50 Å to 200 Å, e.g., 150 Å, is formed over an upper surface of semiconductor substrate 50. In accordance with embodiments of the present invention, a very thin silicon nitride etch stop layer 52 is formed on pad oxide 51. Silicon nitride etch stop layer 52 is typically formed at a thickness of 50 Å to 150 Å, e.g., 100 Å. A trench 53 is then formed in the substrate 50, as by employing conventional photolithographic and etching techniques. At this point, although not illustrated, a thin thermal oxide may be formed lining the trench. Subsequently, as shown in FIG. 6, an insulating material 60, such as silicon oxide, is deposited to fill the trench and form an overburden on the silicon nitride polish stop layer 52, as by CVD. Planarization is then implemented, as by CMP, resulting in the intermediate structure illustrated in FIG. 7, wherein reference character 70 denotes the STI oxide fill. CMP is typically conducted such that when stopping on the silicon nitride polish stop layer 52, no more than 20 Å is removed from the upper surface of silicon nitride polish stop layer 52. In conventional practices, the silicon nitride polish stop layer is removed after CMP followed by conventional masking, ion implanting and cleaning steps to form the active regions, resulting in the formation of divots. However, in accordance with embodiments of the present invention, the relatively thin silicon nitride polish stop layer 52 is retained during subsequent masking, ion implanting and cleaning steps, which are implemented in a conventional manner, resulting in the formation of impurity regions 80, as shown in FIG. 8, which may ultimately be used for source/drain regions of transistors. As silicon nitride polish stop layer 52 is relatively thin, there is virtually little blocking of the ions during implantation. In addition, the silicon nitride layer forms a stable surface enabling greater uniformity in the formation of the impurity regions. Subsequently, the upper surface of the STI oxide fill 70 is removed, as by employing hydrofluoric acid, such that the upper surface 70A is substantially coplanar with the upper surface of semiconductor substrate 50, resulting in the intermediate structure illustrated in FIG. 9. Subsequently, the silicon nitride polish stop layer 52 is removed, as by employing hydrofluoric acid, and the pad oxide layer 51 is then removed, resulting in the structure illustrated in FIG. 10. Subsequent processing is implemented to form a transistor structure as illustrated in FIG. 11, comprising gate electrode 100 overlying semiconductor substrate 50 with gate oxide 101 therebetween, and dielectric sidewall spaces 102 thereon. In FIG. 11 reference 103 represents an interlayer dielectric and element 50 represents an electric contact through the dielectric layer to an active region 80 on substrate 50. The present invention provides methodology enabling the fabrication of semiconductor devices with highly reliable STI regions without or with substantially reduced divot formation. Embodiments of the present invention comprise strategically reducing the thickness of a silicon nitride polish stop layer to below 400 Å and retaining the silicon nitride polish stop layer immediately after CMP to protect the trench corners from isotropic etching during conventional cleaning steps implemented when forming active regions and by retaining the thin silicon nitride polish stop layer during ion implantation, thereby achieving highly uniform implanted regions. The present invention enjoys industrial applicability in fabricating highly integrated semiconductor devices containing STI regions with no or substantially reduced divot formation. The present invention enjoys particular applicability in manufacturing semiconductor devices with sub-micron dimensions. In the preceding description, the present invention is described with reference to specifically exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the present invention, as set forth in the claims. The specification and drawings are, accordingly, to be regarded as illustrative and not as restrictive. It is understood that the present invention is capable of using various other combinations and embodiments and is capable of any changes or modifications within the scope of the inventive concept as expressed herein. | <SOH> BACKGROUND ART <EOH>As miniaturization of elements of an integrated circuit semiconductor device drives the industry, the width and the pitch of an active region have become smaller, thereby rendering the use of traditional LOCOS (local oxidation of silicon) isolation techniques problematic. STI is considered a more viable isolation technique than LOCOS because, by its nature, creates hardly any bird's beak characteristic of LOCOS, thereby achieving reduced conversion differences. Conventional STI fabrication techniques include forming a pad oxide on an upper surface of a semiconductor substrate, forming a nitride, e.g., silicon nitride, polish stop layer thereon, typically having a thickness of greater than 1000 Å, forming an opening in the nitride polish stop layer, anisotropically etching to form a trench in the semiconductor substrate, forming a thermal oxide liner in the trench and then filling the trench with insulating material, such as silicon oxide, forming an overburden on the nitride polish stop layer. Planarization is then implemented, as by conducting chemical mechanical polishing (CMP). During subsequent processing, the nitride layer is removed along with the pad oxide followed by formation of active areas, which typically involve masking, ion implantation, and cleaning steps. During such cleaning steps, the top corners of the field oxide are isotropically removed leaving a void or “divot” in the oxide fill. For example, a conventional STI fabrication technique is illustrated in FIGS. 1 through 4 , wherein similar features are denoted by similar reference characters. Adverting to FIG. 1 , a pad oxide 11 is formed over an upper surface of a semiconductor substrate 10 , and a silicon nitride polish stop layer 12 is formed thereon, typically at a thickness in excess of 1000 Å. A photomask (not shown) is then used to form an opening through the nitride polish stop layer 12 , pad oxide 11 , and a trench 12 is formed in the semiconductor substrate 10 . Subsequently, a thermal oxide liner (not shown) is formed in the trench, an insulating material is deposited and planarization implemented, as by CMP, resulting in the intermediate structure illustrated in FIG. 2 , the reference character 20 denoting the oxide fill. Subsequently, the nitride polish stop layer 12 and pad oxide layer 11 are removed and cleaning steps are performed prior to forming active regions. Such cleaning steps result in the formation of divots 30 as illustrated in FIG. 3 . The STI divots are problematic in various respects. For example, STI divots are responsible for high field edge leakage, particularly with shallow source/drain junctions. As shown in FIG. 4 , silicide regions 41 formed on shallow source/drain regions 40 grow steeply downwards, as illustrated by reference character 42 , below the junction depth formed at a latter stage resulting in high leakage and shorting. Segregation of dopants, notably boron, at STI field edges reduces the junction depth. Accordingly, after the junctions are silicided, the silicide 42 penetrating to the substrate causes shorting routes and, hence, large leakage occurrence from the source/drain junctions to a well or substrate. In addition, if the STI edge becomes exposed as a result of divot formation, a parasitic transistor with a low threshold voltage is formed over the area with low impurity concentration causing a kink in the characteristics curve of a transistor. The presence of a kink results in electrical characteristics different from the design electrical characteristics, thereby preventing the fabrication of transistors with uniform characteristics. Accordingly, there exists a need for methodology enabling the fabrication of highly integrated semiconductor devices with highly reliable STI regions without or with substantially reduced divots. | <SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>FIGS. 1 through 4 schematically illustrate sequential phases of a conventional method for forming STI regions. In FIGS. 1 through 4 , similar features are denoted by similar reference characters. FIGS. 5 through 11 schematically illustrate sequential phases of a method in accordance with an embodiment of the present invention. In FIGS. 5 through 11 , similar features are denoted by similar reference characters. detailed-description description="Detailed Description" end="lead"? | 20040304 | 20060815 | 20050908 | 96195.0 | 0 | TRAN, LONG K | METHOD OF REDUCING STI DIVOT FORMATION DURING SEMICONDUCTOR DEVICE FABRICATION | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,791,949 | ACCEPTED | Manual/automatic pressure control mechanism for centrifugal clutch | A centrifugal clutch for motorcycles having a cam-actuating mechanism to force a series of clutch plates into clutching engagement at a predetermined speed, a pressure limiting spring assembly limits the axial force transmitted to the clutch members at higher speeds so that the torque transmission characteristics of the clutch are similar to a manual clutch, and a manual override is capable of maintaining the clutch plates in the disengaged position at lower speeds as well as shifting the clutch members out of clutching engagement at higher speeds with relatively low exertion of manual or hand pressure. | 1. In a centrifugal clutch of the type having a plurality of cam members interposed between a cover and pressure plate, the cam members being movable radially outwardly under centrifugal force to cause the pressure plate to move in a direction forcing a plurality of clutch members into clutching engagement, the improvement comprising: cam retainer means between said pressure plate and cover for guiding inward and outward radial movement of said cam members; first means for maintaining a predetermined spacing between said cover and said retainer means; second means for maintaining a predetermined spacing between said pressure plate and said retainer means including means biasing said pressure plate and said retainer means towards one another; and a series of circumferentially spaced resilient biasing means interposed between said cover and said retainer means and wherein said resilient biasing means is operative to undergo compression in response to continued radially outward movement of said cam members when the force exerted on said clutch members equals the force exerted by said resilient biasing means on said pressure plate and retainer means. 2. In a centrifugal clutch according to claim 1 wherein said cam retainer means includes a plurality of first indented cam faces arranged in concentric rows, each of said cam faces including a ramp inclining radially outwardly in a direction towards said pressure plate. 3. In a centrifugal clutch according to claim 2 wherein said pressure plate includes a plurality of second indented cam faces aligned with said first indented cam faces to define complementary pairs of said cam faces, each said complementary pair receiving one of said cam members therebetween. 4. In a centrifugal clutch according to claim 1 wherein said first means comprises threaded members extending between said cover and said retainer means. 5. In a centrifugal clutch according to claim 1 wherein said second means includes biasing members between said pressure plate and said retainer means. 6. In a centrifugal clutch according to claim 5 wherein said second means comprises a plurality of circumferentially spaced threaded members connected to said pressure plate and said biasing members are associated with each of said threaded members. 7. In a centrifugal clutch according to claim 6 wherein said biasing members comprises spring members so mounted as to yieldingly compress said pressure plate and said retainer means toward one another. 8. In a centrifugal clutch according to claim 1 wherein disengagement means is provided for locking said pressure plate against advancement into engagement with said clutch members independently of the speed of rotation of said clutch. 9. In a centrifugal clutch according to claim 8 wherein said disengagement means includes a control rod and means for connecting said control rod to said pressure plate. 10. In a centrifugal clutch according to claim 9 wherein said control rod extends centrally of said housing, and said connecting means includes a threadedly adjustable stem in the path of movement of said control rod. 11. In a centrifugal clutch having a plurality of cam members interposed between a cover and pressure plate, said cam members being movable radially outwardly under centrifugal force to cause said pressure plate to move in a direction forcing a plurality of clutch members into clutching engagement, the improvement comprising: cam retainer means between said pressure plate and said cover for retaining said cam members in a plurality of concentric rows whereby to guide inward and outward radial movement of said cam members; first fastener means for maintaining a predetermined spacing between said cover and said retainer means; second fastener means for maintaining a predetermined spacing between said pressure plate and said retainer means including means biasing said pressure plate and said retainer means toward one another; a series of circumferentially spaced resilient biasing means interposed between said cover and said retainer means and wherein said resilient biasing means is defined by circumferentially spaced compression springs adapted to undergo compression in response to continued radially outward movement of said cam members once the force exerted on said clutch members equals the force exerted by said resilient biasing means on said pressure plate and retainer means; and manual disengagement means engageable with said pressure plate to prevent engagement between said pressure plate and said clutch members independently of the speed of rotation of said clutch. 12. In a centrifugal clutch according to claim 11 wherein said disengagement means is provided for locking said pressure plate against advancement into engagement with said clutch members. 13. In a centrifugal clutch according to claim 12 wherein said disengagement means includes a control rod and means for connecting said control rod to said pressure plate. 14. In a centrifugal clutch according to claim 13 wherein said control rod extends centrally of said housing, and said connecting means includes a threadedly adjustable stem in the path of movement of said control rod. 15. In a centrifugal clutch according to claim 11 wherein said pressure plate and said retainer means include a plurality of indented cam faces arranged in inner and outer concentric rows and aligned with and facing one another to define complementary pairs of said cam faces, each said complementary pair receiving one of said cam members therebetween. 16. In a centrifugal clutch according to claim 11 wherein said outer row of said cam faces in said retainer means each includes a ramp inclining radially outwardly in a direction towards said pressure plate. 17. In a centrifugal clutch according to claim 16 wherein said first fastener means comprises threaded members extending between said cover and said retainer means. 18. In a centrifugal clutch according to claim 17 wherein said second fastener means comprises a plurality of circumferentially spaced threaded members interconnecting said pressure plate and said retainer means, and compression spring members associated with said threaded members to bias said pressure plate and said retainer means toward one another. 19. In a centrifugal clutch according to claim 11 wherein said resilient biasing means comprises a plurality of circumferentially spaced compression springs extending between outer peripheral portions of said cover and said retainer means. 20. In a centrifugal clutch according to claim 19 wherein each of said springs is a flat wire compression spring. 21. In a centrifugal clutch according to claim 20 wherein each of said spring elements is a SPIRAWAVE® spring. 22. A centrifugal clutch having a rotary member to be driven, a hub coupled to said rotary member, a rotatable housing in outer spaced concentric relation to said rotary member, clutch members mounted for relative axial displacement into and out of engagement with one another between said hub and said housing, and a pressure plate axially displaceable between a cover and said clutch members; a plurality of cam members interposed between said cover and said pressure plate being movable radially outwardly at a predetermined speed of rotation to force said pressure plate axially away from said cover and in a direction causing said clutch members to move into clutching engagement with one another including cam guide means between said pressure plate and said cover for guiding the radial movement of said cam members; and pressure means between said cover and said pressure plate to prevent shock loads from being imparted to said clutch members when said clutch members are in clutching engagement with one another. 23. A clutch for motorcycles disposed between a crankshaft of an engine and a transmission shaft wherein said clutch is provided with an inner hub coupled to said transmission shaft, an outer housing coupled to said crankshaft, frictional clutch members alternately extending from and fixed for rotation with said hub and said housing, respectively, and being axially displaceable into and away from frictional engagement with one another, a pressure plate at one end of said clutch members including spring means biasing said pressure plate in an axial direction away from said clutch members, and centrifugal force-responsive means movable radially and outwardly along said pressure plate to overcome said spring means and force said pressure plate axially against an endmost of said clutch members whereby to impart rotation between said housing and said hub, an elongated control rod extending centrally of said housing and being axially slidable with respect to said housing, actuating means between one end of said rod and said pressure plate being movable in response to axial movement of said rod to displace said pressure plate in an axial direction independently of said spring means, manual control means for selectively advancing and retracting said rod in an axial direction whereby to manually control engagement and release of said clutch members independently of the speed of rotation of said clutch and pressure control means between said cover and said pressure plate to absorb shock loads between said clutch member and said transmission shaft. 24. An automatic clutch according to claim 23, said centrifugal force-responsive means having circumferentially spaced first and second cam faces disposed in facing relation to one another between said pressure plate and said housing, said first and second cam faces arranged in a plurality of concentric rows. 25. An automatic clutch according to claim 23, a plurality of cam members disposed between said first and second cam faces in each of said concentric rows wherein said cam members are movable radially outwardly between said cam faces to force said housing axially away from said drive unit and in a direction causing said clutch members to move into clutching engagement with one another. 26. An automatic clutch according to claim 23 wherein said centrifugal force-responsive means includes circumferentially spaced rows of first and second cam faces disposed in facing relation to one another between said pressure plate and said cover and a plurality of cam members disposed between said first and second cam faces being movable radially outwardly between said cam faces to force said pressure plate in an axial direction causing said clutch members to move into clutching engagement with one another. 27. An automatic clutch according to claim 23 wherein said pressure control means includes a plurality of circumferentially spaced compression springs interposed between said cover and said centrifugal force-responsive means. 28. An automatic clutch according to claim 27 wherein said compression springs are flat wire wave springs. 29. An automatic clutch according to claim 28 wherein each of said compression springs includes inner and outer concentric flat wire wave springs mounted in spring seats between said cover and said centrifugal force-responsive means. 30. An automatic clutch according to claim 29 wherein said cover includes an axially movable portion interposed between said cover and said pressure plate. | CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of patent application Ser. No. 09/877,518, filed 7 Jun. 2001 for AUTOMATIC CLUTCH WITH MANUAL OVERRIDE CONTROL MECHANISM and application Ser. No. 10/327,160, filed 20 Dec. 2002 for MULTI-ROW CAM-ACTUATED CENTRIFUGAL CLUTCH, both applications by Douglas W. Drussel and George Michael Wilfley, both being applications assigned to the assignee of this invention and incorporated by reference herein. BACKGROUND AND FIELD OF INVENTION This invention relates to centrifugal clutches and more particularly relates to a novel and improved centrifugal clutch which is capable of manual and automatic control of the maximum pressure exerted on the clutch plates when moved into the engaged position as well as the amount of pressure required to disengage the clutch plates. We have previously devised centrifugal clutches of the type having a plurality of cam members or balls which will move outwardly in response to rotation of a drive shaft to force a plurality of clutch plates into engagement with one another. In certain applications, such as, motorcycle clutches it is important to generate sufficient centrifugal force to clamp the clutch plates together without substantial slippage and without utilizing a larger sized case which exceeds the space allowances within a stock or standard engine case. Space is at a particular premium in motorcycle clutches incorporating a manual override mechanism, such as, set forth in hereinbefore referred to U.S. application Ser. No. 10/327,160 for MULTI-ROW CAM-ACTUATED CENTRIFUGAL CLUTCH. Further, it is desirable to incorporate into the end of the clutch case between the cover and pressure plate a pressure control mechanism which will combine the features of an automatic clutch with the performance of a traditional manual clutch so that the clutch can engage smoothly without the use of a clutch lever at low speeds but at the same time limit the axial force transmitted to the clutch plates by the cam members at higher speeds. In addition, it is highly desirable that the pressure control mechanism cooperate with the manual override lever in such a way as to minimize the hand pressure required to override the cam members and effectively operate as a conventional manual clutch with relatively light feel or manual pressure and yet be capable of operating within the same space limitations as the standard or stock motorcycle clutches. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide for a novel and improved clutch of a type which is capable of controlling the maximum pressure exerted on the clutch elements while assuring non-slipping clutch engagement up to a predetermined force or pressure level as well as being manually controllable to disengage independently of the pressure control mechanism. It is another object of the present invention to provide, in a centrifugal clutch of the type having an internal manual disengagement mechanism, for an automatic pressure control mechanism which will limit the maximum pressure to which the clutch elements can be subjected and without expanding the size of clutch housing required. A further object of the present invention is to provide, in a motorcycle clutch, for non-slipping engagement under normal operating conditions while limiting the maximum pressure to which the clutch elements can be subjected in order to permit controlled slippage of the clutch elements when subjected to shock loads imparted through the drive train of the vehicle on which the clutch is mounted. It is a still further object of the present invention to provide in a motorcycle clutch for a maximum pressure spring control mechanism of the type employing multiple, circumferentially spaced springs between a cover and retainer plate for the centrifugal clutch-actuating mechanism to limit the maximum amount of pressure applied to the clutch members and to mount same within a standard or stock motorcycle case. The present invention resides in a centrifugal clutch of the type having a plurality of cam members or balls interposed between a cover and pressure plate, the cam members being movable radially outwardly under centrifugal force to cause the pressure plate to move in a direction forcing the clutch members into clutching engagement, the improvement comprising cam retainer means between the pressure plate and cover for retaining the cam members in one or more concentric rows whereby to guide inward and outward radial movement of the cam members, first fastener means for maintaining a predetermined spacing between the cover and the retainer means, second fastener means for maintaining a predetermined spacing between the pressure plate and retainer means including means resiliently biasing the pressure plate and retainer means toward one another, and a series of circumferentially spaced resilient biasing members interposed between the cover and retainer means and wherein the resilient biasing members are operative to undergo compression in response to continued radially outward movement of the cam members once the force exerted on the friction plates equals the force exerted by the resilient biasing members on the pressure plate and retainer means. There has been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view partially in section of a centrifugal clutch for a motorcycle and illustrating the clutch in a disengaged position; FIG. 1A is a view in more detail of the maximum pressure wave springs employed in accordance with the present invention; FIG. 2 is a view similar to FIG. 1 but illustrating the clutch in an engaged position; FIG. 3 is a view similar to FIGS. 1 and 2 illustrating the clutch engaged at maximum force; FIG. 4 is a view similar to FIGS. 1 to 3 but illustrating the clutch disengaged by a manual override mechanism; FIG. 5 is an exploded view of the major elements of the clutch shown in FIGS. 1 to 4; FIG. 6 is an end view of a stationary cover portion of the clutch shown in FIGS. 1 to 5; FIG. 7 is a cross-sectional view taken about lines 7-7 of FIG. 6 and of FIG. 8; FIG. 8 is an opposite end view to that of FIG. 6; FIG. 9 is an end view of a movable cover portion for the clutch of FIGS. 1 to 5; FIG. 10 is a cross-sectional view taken about lines 10-10 of FIG. 9; FIG. 11 is an opposite end view to that of FIG. 9; FIG. 12 is a cross-sectional view taken about lines 12-12 of FIGS. 9 and 11; FIG. 13 is an end view of a pressure plate employed in the clutch of FIGS. 1 to 5; FIG. 14 is a cross-sectional view taken about lines 14-14 of FIGS. 13 and 15; FIG. 14A is a cross-sectional view taken about line 14A of FIG. 15; FIG. 15 is an opposite end view of the cover shown in FIG. 13; and FIG. 16 is a view partially in section of a modified form of clutch in accordance with the present invention. DETAILED DESCRIPTION OF ONE FORM OF INVENTION Referring to the drawings, there is shown by way of illustrative example in FIGS. 1 to 14A a representative form of clutch 10 which is specifically adaptable for use in a motorcycle, not shown. In the standard motorcycle, a crankshaft from an engine imparts rotation to a power input side of the clutch through a shaft or pinion or a chain or other means. In the case shown, a chain is used to impart rotation to drive sprocket 13 on clutch housing 14. A transmission shaft 16 is mounted for rotation by a hub 26 when clutch plates 22 and 24 are engaged; and through a transmission, not shown, is operative to rotate a belt or chain drive, not shown, to the rear wheel of the motorcycle. A starter gear 12 can receive input power from a starter, not shown, to rotate the housing 14 and drive sprocket 13 which in turn rotates the crankshaft to start the engine. As illustrated in FIG. 1, a control rod 18 extends through the transmission shaft 16 and is manually controlled by a hand lever L typically mounted on the handlebar of the motorcycle and operates through a control cable C to force a threadedly adjustable stem 20 forwardly to disengage the clutch plates 22 and 24 between the outer housing 14 and hub 26, respectively. As best seen from FIGS. 1 to 15, a cam-actuating mechanism 28 is mounted between a pressure plate 30 and a cover 32. The cover 32 comprises an annular stationary wall portion 34 having an outer peripheral edge 35 affixed to the housing 14 by suitable fasteners 36. In addition, the cover 32 includes an inner movable cover portion 38 made up of a relatively thick inner wall portion 39 and an outer relatively thin annular retainer portion 40 which extends directly behind the annular cover portion 34. The cam-actuating mechanism 28 is comprised of radially inner and outer rows of circumferentially spaced cam members or balls 42 and 44 interposed between the pressure plate 30 and the retainer portion 40. The balls 42 and 44 are responsive to centrifugal force to roll outwardly along radial pockets or cam faces 46 and 48 in the pressure plate 30, shown in FIGS. 13 to 15, and aligned pockets or cam faces 50 and 52 in the retainer portion 40 of the cover 38, as shown in FIGS. 9 to 12, so as to cause the pressure plate 30 to axially displace the outer frictional clutch plates 22 into locking engagement with the inner clutch plates 24. The cam-actuating mechanism 28 is modified somewhat from that of hereinbefore referred to copending application for patent for MULTI-ROW CAM-ACTUATED CENTRIFUGAL CLUTCH by utilizing only one row of cam faces 46 and 50 in inner, staggered concentric relation to the outer row of cam faces 48 and 52, respectively, in the pressure plate 30 and cover portion 40. Nevertheless, it will be apparent that a third row of confronting cam faces in the pressure plate 30 and cover portion 40 may be utilized for a set of smaller balls, as shown and described in my hereinbefore referred to copending application for patent for MULTI-ROW CAM-ACTUATING CENTRIFUGAL CLUTCH to generate increased clamping force between the clutch plates 22 and 24. In accordance with the present invention, the cam faces 50 and 52 are in the form of pockets of generally oval-shaped configuration indented in a flat surface of the movable cover portion 40 and are elongated in the radial direction. Similarly, the cam faces 46 and 48 in the pressure plate 30, as best seen from FIGS. 14 and 15, are in the form of radial pockets of generally concave configuration elongated in a radial direction and correspond in size and configuration to the aligned cam faces 50 and 52 in the retainer portion. However, the cam faces 48 in the outer row of the pressure plate 30 each terminate in flattened surface portions 49 so as to form a stop point at the outer peripheral edge of the pressure plate 30 to limit the travel of the cam members 44. Just inwardly of the inner row of cam faces 46, a plurality of circumferentially spaced counterbores 54 are aligned with bores 56 in the cover portion 38, the bores 56 being adapted for insertion of threaded fasteners in the form of shoulder bolts 58 between the cover portions 38 and 32 while leaving a predetermined spacing or clearance 60 between the cover portions for a purpose to be hereinafter described. It will be noted that the cover portion 38 is axially displaceable with respect to the threaded fasteners in the form of shoulder bolts 58 so as to move through the clearance space 60 in response to increased spreading forces applied by the balls 42 and 44 after the clutch plates 22 and 24 have moved into clutching engagement as will be later described with reference to FIG. 3. A second series of circumferentially spaced bores 62 are formed in the cover 38 in the raised or center portion 39 of the cover 38 and are adapted to receive tubular posts 63 extending from the pressure plate 30 for insertion of threaded fasteners in the form of bolts 64. A spring retainer in the form of a washer 65 having an annular shoulder 66 is positioned at one end of each tubular post 63 to receive each bolt 64. The wall of each bore 62 is provided with an annular shoulder 68 in opposed facing relation to the external shoulder 66 so that the shoulders 66 and 68 define end stops for a spring 70 which is mounted under compression therebetween. The springs 70 pre-load the balls 42 and 44 under a predetermined amount of force to resist outward radial movement of the balls 42 and 44 until the engine reaches a predetermined speed imparting a sufficient degree of centrifugal force to the balls 42 and 44 to advance outwardly along their respective cam faces. The pre-compression or pre-loading of the springs 70 can be adjusted by shims 71 as well as the inward threading of each bolt 64 to vary the distance between the shoulders 66 and 68. Preferably, the springs 70 are SPIRAWAVE® wave springs which are flat wire compression springs, Model No. C075 manufactured and sold by Smalley Steel Ring Co. of Lake Zurich, Ill. A series of maximum pressure spring pairs 72, 72A are mounted between counterbored seats 74 in circumferentially spaced relation to one another around the outer periphery of the cover portion 40 and aligned bores or spring seats 75 in the confronting surface of the cover 32. Preferably, the spring pairs 72, 72A are made up of inner and outer concentric SPIRAWAVE® wave springs as illustrated in the detail view of FIG. 1A which in unison will be compressed as the pressure plate 30 and cover portion 40 are expanded to move the clutch plates 22 and 24 into engagement, as shown in FIG. 2, until the clamping force exerted on the clutch plates 22 and 24 equals the resisting force exerted by the springs 72, 72A. Further, the clearance space 60 between the cover portions 32 and 40 will move into engagement before the springs 72, 72A are compressed beyond their usable travel which is the amount of deflection without permanent deformation of the springs 72, 72A. An important characteristic of the SPIRAWAVE® wave springs 72 and 72A is their greatly reduced height or travel for a given amount of resistance as compared to standard coil springs and therefore occupy much less space in an axial direction. In this way, the cam-actuating mechanism 28 together with the spring force-limiting mechanism as described will fit into existing clutch housings, such as, the twin cam 88 of Harley-Davidson Motor Company of Milwaukee, Wis. and other makes of motorcycles. The spring force of the springs 72, 72A is such as to resist opening or spreading of the pressure plate 30 and cover portion 40 beyond a predetermined limit. That limit is the maximum clamping force that can be safely exerted on the clutch plates 22 and 24 to assure non-slipping engagement under normal operating conditions but which will permit the clutch plates 22 and 24 to slip in the event that extreme shock loads are transmitted through the drive train. For example, the clutch plates will permit slight or instantaneous slippage so as to absorb any shock loading when the rear wheel of the motorcycle is off the ground and spinning then suddenly hits the ground and is stopped while the engine continues to run. When extreme clamping forces of that nature are applied, the cam-actuating mechanism 28 will overcome the force or bias of the springs 72, 72A to shift away from the clutch plates 22 and 24, as best seen from FIG. 4, through the clearance space 60. This enables limited movement of the entire cam-actuating mechanism 28 away from the clutch plates 22 and 24 until the cover portion 40 abuts the cover portion 34. Sufficient clearance is provided, also, between the clutch plates 22 and 24 and pressure plate 30 as generally designated at 61 to adjust for any wear in the clutch plates 22 and 24. For example, as the clutch plates 22 and 24 undergo wear, they will create a greater clearance space 61, but the cam-actuating mechanism is capable of undergoing greater spreading before the maximum pressure springs 72, 72A will exert a counteracting force on the cam-actuating mechanism 28. FIG. 1 illustrates the clutch 10 at rest or operating at low speeds with the clutch plates 22 and 24 therefore disengaged. As engine speed increases, the balls 42 and 44 will advance radially outwardly to force the pressure plate 30 toward the clutch plates 22 and 24 and simultaneously urge the cover portion 40 in the opposite direction against the resistance of the springs 72, 72A until the resistance of the clutch plates equals that of the springs 72, 72A, for example, as illustrated in FIG. 2. As illustrated in FIG. 3, as the balls 42 and 44 continue to move outwardly under increasing speeds, the cover portion 40 will continue to advance axially against the springs 72, 72A so that no increased force is applied to the clutch plates, and the balls 42 and 44 will have reached the limit of the ball pockets, as illustrated in FIG. 3. A notable advantage of utilizing concentric wave springs 72, 72A of the type described is that the stationary cover 32 retains sufficient strength to avoid expansion or buckling of the cover 32 when maximum forces are applied to the springs 72, 72A. In addition, the spring force can be adjusted by selecting the number of springs 72 to be inserted between the pressure plate 30 and cover portion 40. For example, a spring 72 may be positioned in every other spring seat 75. Correspondingly, the number of inner springs 72A may be varied but preferably are used only in combination with an outer spring 72. Further, the amount or degree of pre-loading force of resistance of the springs 70 can be fine-tuned or adjusted by the utilization or one or more shims 71. There are certain conditions under which it is desirable to be able to control the clutch manually and to override the automatic clutch. As illustrated in FIGS. 1 to 4, the push rod 18 extends through the transmission shaft 16 from the manual control lever L which operates the push rod 18 through the control cable C as shown in FIG. 1. A leading end 76 of the push rod is aligned with a trailing end 78 of the threadedly adjustable stem 20, and the stem 20 threadedly engages a disk 79 having an outer peripheral edge which is fixed to an inner wall 80 of the pressure plate 30 by a snap ring 82. A lock nut 84 is threaded onto the stem 20 to fix the axial disposition or relationship of the stem 20 to the push rod 18 and control the distance of travel of the pressure plate 30 in response to actuation of the push rod 18. Accordingly, when the push rod 18 is actuated by the control lever, it will cause the entire cam-actuating mechanism 28 to be displaced away from the clutch plates 22 and 24, as illustrated in FIG. 4. At low speeds, engaging the push rod 18 will cause the pressure plate 30 to be held away from the clutch plates 22 and 24. This requires no or minor compression of the springs 70 so that the physical effort required to hold the pressure plate is minimal. At high speeds, the push rod 18 can still be engaged to release the clutch but have to move the entire cam-actuating mechanism 28 as an assembly away from the clutch plates 22 and 24 by compressing the springs 72, 72A. This requires a greater physical force than at low speeds but never more than the force exerted by the springs 72, 72A. The following are representative of different situations in which it is desirable to manually disengage the clutch: 1. Manually disengage at start of a race and rev up the engine to create a sufficiently high torque that a fast start can be initiated. 2. In traversing a curve or corner, to disengage the clutch to cut speed but rev up the engine and engage it to accelerate quickly. 3. When starting the engine with transmission in gear, manually disengage the clutch to keep the motorcycle at rest. 4. In climbing a hill, slipping the clutch manually makes it easier to generate higher engine speed in order to get more power to get up the hill. 5. To lift the front wheel over an obstacle, manually disengage the clutch, increase engine speed and re-engage the clutch for rapid acceleration. As shown in FIG. 3, when the speed is reduced below that required to move the clutch plates 22 and 24 into engagement, the springs 70 will rapidly force the balls 42, 44 to move inwardly and permit the pressure plate 30 to retract away from the clutch plates 22, 24 and return to the position shown in FIG. 1. It will be evident that other spring types may be utilized in place of the SPIRAWAVE® wave springs 70 depending upon the spring force required to counteract the centrifugal force of the cam-actuating mechanism 28 as well as the space available for a given amount of counteracting spring force required. Other factors to be considered are the amount of torque that the clutch is required to transmit, the size of the clutch plates 22 and 24, and the hand pressure required to disengage the clutch manually. Accordingly, other types of springs may be utilized, such as, coil springs and Belleville washer springs, the latter extending through a circumferential groove in the inner surface of the cover; however, for a given size or thickness of cover will be substantially weakened by a continuous circumferential groove, and a continuous spring element ordinarily will not achieve the same spring force for a given distance of travel. Modified Form of Invention A modified form of invention is illustrated in FIG. 16 in which like parts are correspondingly enumerated to the preferred form of FIGS. 1 to 15. When employed in a motorcycle, a chain imparts rotation to drive sprocket 96 on clutch housing 97. A transmission shaft 101 is mounted for rotation by hub 102 when the clutch plates 22 and 24 are engaged; and through a transmission, not shown, is operative to rotate a belt or chain drive, not shown, to the rear wheel of the motorcycle. A starter gear 95 is operative to rotate the housing 97 and the drive sprocket 96 which in turn rotates a crankshaft to start the engine. A pull rod or stem 98 is used in place of the push rod 18 and threaded stem 20 of the preferred form to manually disengage the clutch. Thus, the stem 98 is journaled to the cover portion 94 by a ball bearing assembly 99 which is mounted in the center of the pressure plate 100. The stem or control rod 98 may be directly controlled by a hand lever, not shown, in the same manner as the lever L of FIG. 1. Both with respect to the preferred and modified forms of invention, it will be appreciated that they are readily conformable for use in other applications than motorcycles and are adaptable for use in any application which employs an internal combustion engine, such as, for instance drag racing, cars, trucks, tractors, go-carts, cement mixers, all terrain vehicles, power tools including but not limited to chain saws and weed eaters and virtually any application in which an automatic clutch can be utilized. It is therefore to be understood that while preferred and modified forms of invention are herein set forth and described, the above and other modifications may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and reasonable equivalents thereof. | <SOH> BACKGROUND AND FIELD OF INVENTION <EOH>This invention relates to centrifugal clutches and more particularly relates to a novel and improved centrifugal clutch which is capable of manual and automatic control of the maximum pressure exerted on the clutch plates when moved into the engaged position as well as the amount of pressure required to disengage the clutch plates. We have previously devised centrifugal clutches of the type having a plurality of cam members or balls which will move outwardly in response to rotation of a drive shaft to force a plurality of clutch plates into engagement with one another. In certain applications, such as, motorcycle clutches it is important to generate sufficient centrifugal force to clamp the clutch plates together without substantial slippage and without utilizing a larger sized case which exceeds the space allowances within a stock or standard engine case. Space is at a particular premium in motorcycle clutches incorporating a manual override mechanism, such as, set forth in hereinbefore referred to U.S. application Ser. No. 10/327,160 for MULTI-ROW CAM-ACTUATED CENTRIFUGAL CLUTCH. Further, it is desirable to incorporate into the end of the clutch case between the cover and pressure plate a pressure control mechanism which will combine the features of an automatic clutch with the performance of a traditional manual clutch so that the clutch can engage smoothly without the use of a clutch lever at low speeds but at the same time limit the axial force transmitted to the clutch plates by the cam members at higher speeds. In addition, it is highly desirable that the pressure control mechanism cooperate with the manual override lever in such a way as to minimize the hand pressure required to override the cam members and effectively operate as a conventional manual clutch with relatively light feel or manual pressure and yet be capable of operating within the same space limitations as the standard or stock motorcycle clutches. | <SOH> SUMMARY OF THE INVENTION <EOH>It is therefore an object of the present invention to provide for a novel and improved clutch of a type which is capable of controlling the maximum pressure exerted on the clutch elements while assuring non-slipping clutch engagement up to a predetermined force or pressure level as well as being manually controllable to disengage independently of the pressure control mechanism. It is another object of the present invention to provide, in a centrifugal clutch of the type having an internal manual disengagement mechanism, for an automatic pressure control mechanism which will limit the maximum pressure to which the clutch elements can be subjected and without expanding the size of clutch housing required. A further object of the present invention is to provide, in a motorcycle clutch, for non-slipping engagement under normal operating conditions while limiting the maximum pressure to which the clutch elements can be subjected in order to permit controlled slippage of the clutch elements when subjected to shock loads imparted through the drive train of the vehicle on which the clutch is mounted. It is a still further object of the present invention to provide in a motorcycle clutch for a maximum pressure spring control mechanism of the type employing multiple, circumferentially spaced springs between a cover and retainer plate for the centrifugal clutch-actuating mechanism to limit the maximum amount of pressure applied to the clutch members and to mount same within a standard or stock motorcycle case. The present invention resides in a centrifugal clutch of the type having a plurality of cam members or balls interposed between a cover and pressure plate, the cam members being movable radially outwardly under centrifugal force to cause the pressure plate to move in a direction forcing the clutch members into clutching engagement, the improvement comprising cam retainer means between the pressure plate and cover for retaining the cam members in one or more concentric rows whereby to guide inward and outward radial movement of the cam members, first fastener means for maintaining a predetermined spacing between the cover and the retainer means, second fastener means for maintaining a predetermined spacing between the pressure plate and retainer means including means resiliently biasing the pressure plate and retainer means toward one another, and a series of circumferentially spaced resilient biasing members interposed between the cover and retainer means and wherein the resilient biasing members are operative to undergo compression in response to continued radially outward movement of the cam members once the force exerted on the friction plates equals the force exerted by the resilient biasing members on the pressure plate and retainer means. There has been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. | 20040302 | 20060321 | 20050106 | 63138.0 | 1 | RODRIGUEZ, SAUL | MANUAL/AUTOMATIC PRESSURE CONTROL MECHANISM FOR CENTRIFUGAL CLUTCH | SMALL | 1 | CONT-ACCEPTED | 2,004 |
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