US3882308A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Detection system for superposed sheets
Assignee: Xerox Corp
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Filing: 1970-04-06
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Granted: 1975-05-06
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Expires: 1990-04-06
Abstract
Abstract A multiple sheet detecting system for use in a sheet feed path to provide a signal to a machine control when superposed sheets are fed past a detection station. The detection system has a source of illumination and photosensitive elements at the detection station. Illumination is interrupted by the presence of a sheet or sheets in the sheet path and also by a sample sheet such that a comparison is made between the sample and fed sheets. An electronic circuit coupled to the photosensitive elements which experience a change in resistance depending upon the transmittance of a sheet or sheets in the sheet path generates an output signal when there is a multiple sheet condition. The circuit may be calibrated for varying circuit parameters to accommodate different sheet weights and types.
Inventors
- 👤 John W Daughton
- 👤 Gary L Schluntz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:13
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/70; G03G15/703; B; B65; B65H; B65H7/00; B65H7/02; B65H7/14
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
202 words
In a recording machine in which copy sheets are advanced through copy processing stations along a predetermined path, an improved detection apparatus for detecting multiple superposed sheets at a sheet detection station comprising means for feeding sheet material along a sheet path past copy processing stations, illumination means positioned along the sheet path at a sheet detection station, first photosensitive means for receiving illumination from said illumination means, second photosensitive means for receiving illumination from said illumination means, sample sheet material interposed between said illumination means and said second photosensitive means, first circuit means for generating discrete electrical signals representative of the transmittance of sheet material to be detected, second circuit means responsive to the transmittance of the sample sheet material for generating a signal representative of the transmittance of said sample sheet material, third circuit means for comparing the signals generated from said first and second circuit means and determining the presence of multiple superposed sheets and generating an output signal to machine control to de-energize the machine when a multiple superposed sheet condition occurs at the sheet detection station, and means for maintaining a multiple superposed sheet output condition in the event that a failure of said illumination means occurs.
Claim 2
Dependent Claim
202 words
In a recording machine in which copy sheets are advanced through copy processing stations along a predetermined path, an improved detection apparatus for detecting multiple superposed sheets at a sheet detection station comprising means for feeding sheet material along a sheet path past copy processing stations, illumination means positioned along the sheet path at a sheet detection station, first photosensitive means for receiving illumination from said illumination means, second photosensitive means for receiving illumination from said illumination means, sample sheet material interposed between said illumination means and said second photosensitive means, first circuit means for generating discrete electrical signals representative of the transmittance of sheet material to be detected, second circuit means responsive to the transmittance of the sample sheet material for generating a signal representative of the transmittance of said sample sheet material, third circuit means for comparing the signals generated from said first and second circuit means and determining the presence of multiple superposed sheets and generating an output signal to machine control to de-energize the machine when a multiple superposed sheet condition occurs at the sheet detection station, and means for maintaining a multiple superposed sheet output condition in the event that a failure of said illumination means occurs.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |