US4243216A
Expired / Lapsed
US
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Double document detection system
Assignee: NCR Canada Ltd
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Filing: 1979-06-11
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Granted: 1981-01-06
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Expires: 1999-06-11
Abstract
Abstract A system for detecting the presence of more than one document along a path during the processing of the documents. A capacitance is introduced by the plural documents in contact with each other and wherein a delay signal is combined with an original signal to generate a multiple document detect signal for indicating the presence of the multiple documents.
Inventors
- 👤 Ali T. Mazumder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:14
CPC Classifications
G; G06; G06K; G06K13/00; G06K13/02; G06K13/06; G06K13/067
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
141 words
A double document detector comprising a conductive capacitor type sensing device operable for utilizing a document as the dielectric thereof and for generating a signal upon physically detecting a document, first R-C circuit means for introducing a capacitive delay in the generated signal due to the presence of one or more documents, AND gate means for comparing the generated signal with the delayed signal and generating an output signal, second R-C circuit means for introducing a capacitive delay in the output signal of said AND gate means to compensate for capacitance other than capacitance due to the presence of two or more documents, and inverter means receiving said delayed output signal from said AND gate means for generating a multiple document signal upon the presence of capacitive delay indicating that more than one document has been detected by said sensing device.
Claim 2
Dependent Claim
141 words
A double document detector comprising a conductive capacitor type sensing device operable for utilizing a document as the dielectric thereof and for generating a signal upon physically detecting a document, first R-C circuit means for introducing a capacitive delay in the generated signal due to the presence of one or more documents, AND gate means for comparing the generated signal with the delayed signal and generating an output signal, second R-C circuit means for introducing a capacitive delay in the output signal of said AND gate means to compensate for capacitance other than capacitance due to the presence of two or more documents, and inverter means receiving said delayed output signal from said AND gate means for generating a multiple document signal upon the presence of capacitive delay indicating that more than one document has been detected by said sensing device.
Claim 3
Dependent Claim
147 words
In a document handling apparatus, means for detecting the passage of double documents along a path comprising a conductive capacitor type sensing device operable for utilizing a document as the dielectric thereof and for generating a signal upon physically detecting a document, first R-C circuit means for introducing a delay in the generated signal due to the presence of a document, AND gate means for comparing the generated signal with the delayed signal and generating an output signal, second R-C circuit means for introducing a capacitive delay in the output signal of said AND gate means to compensate for capacitance other than capacitance due to the presence of two or more documents, and means receiving said delayed output signal from said AND gate means for generating a double document signal when said delayed output signal indicates that more than one document is detected by said sensing device.
Claim 4
Dependent Claim
147 words
In a document handling apparatus, means for detecting the passage of double documents along a path comprising a conductive capacitor type sensing device operable for utilizing a document as the dielectric thereof and for generating a signal upon physically detecting a document, first R-C circuit means for introducing a delay in the generated signal due to the presence of a document, AND gate means for comparing the generated signal with the delayed signal and generating an output signal, second R-C circuit means for introducing a capacitive delay in the output signal of said AND gate means to compensate for capacitance other than capacitance due to the presence of two or more documents, and means receiving said delayed output signal from said AND gate means for generating a double document signal when said delayed output signal indicates that more than one document is detected by said sensing device.
Claim 5
Independent Claim
103 words
A method of detecting double documents comprising the steps of: generating a signal upon physically detecting a document, introducing a capacitive delay in the generated signal due to presence of one or more documents, inverting the generated signal delayed due to presence of more than one document, comparing the generated signal with the delayed signal to generate and output signal, introducing a capacitive delay in the output signal to compensate for capacitance other than capacitance due to the presence of two or more documents, and generating a double document signal when the delayed output signal indicates that more than one document is detected.
Claim 6
Independent Claim
103 words
A method of detecting double documents comprising the steps of: generating a signal upon physically detecting a document, introducing a capacitive delay in the generated signal due to presence of one or more documents, inverting the generated signal delayed due to presence of more than one document, comparing the generated signal with the delayed signal to generate and output signal, introducing a capacitive delay in the output signal to compensate for capacitance other than capacitance due to the presence of two or more documents, and generating a double document signal when the delayed output signal indicates that more than one document is detected.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-06 | 1984-07-07 | 1985-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-06 | 1988-07-07 | 1989-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-06 | 1992-07-07 | 1993-01-06 | $7700.00 | Window Closed / Lapsed |