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Recirculating Automatic Document Feeder Testing

IP.com Disclosure Number: IPCOM000061914D
Original Publication Date: 1986-Jul-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Brooks, WR: AUTHOR [+2]

Abstract

A personal computer is used to determine the position of paper in a recirculating automatic document feeder (RADF) during test of the RADF. The computer detects an analog signal which is generated by light emitting diode (LED) photo sensors. The position of the paper determines the amount of light which is detected.

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Recirculating Automatic Document Feeder Testing

A personal computer is used to determine the position of paper in a recirculating automatic document feeder (RADF) during test of the RADF. The computer detects an analog signal which is generated by light emitting diode (LED) photo sensors. The position of the paper determines the amount of light which is detected.

During test of a copier RADF device, registration (i.e., the position) of paper on a simulated copier's document glass must be determined. This is accomplished by using LED's, and their electrical control modules, to generate an analog signal. This signal is sent to a personal computer which is interfaced with an analog to digital conversion board.

When the LED unit is pointed upward to a white backing surface on the RADF directly above the document glass, a specified analog signal value is generated. However, when a sheet of contrasting colored paper (for example, black paper) comes in front of the RADF's white background, at the point of the sensor, a different analog value results. The LED can therefore return various analog signal values, as a function of the amount of LED light reflection caused by the difference between the edge of the dark paper and the RADF's white background at the point at which the LED is focused. This variable analog signal value is used to determine the position of the paper.

The computer is first taught the correct position of a properly positioned sheet of paper. This is d...