US 4,365,151 AGranted

Sensor for a document processor

AssigneeBurroughs Corporation

InventorsHarold A. Fasig, Anthony Horak

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Abstract

Apparatus for detecting the presence of documents in a document pathway employing a light source and a light sensor positioned to function in cooperation with a drum. The drum employs a peripheral surface for support of documents as they are transported across a cylindrical surface which is recessed below the peripheral surface for reflecting light. The positions of the light source and the sensor are selected so that, when no document is present, light from the light source will be reflected from the recessed cylindrical surface onto the sensor enabling the sensor to provide an output indicating no document is present. When a document is present, light from the light source will be reflected from the surface of the document along a path which will substantially miss the sensor and not energize it, thereby enabling associated circuitry to determine that a document is present.

Claims9

Dependent claims

A system, in a document processing machine having a document track, for use in detecting the passage of documents along the track, comprising:

an alignment drum having a substantially cylindrical outer surface aligned along the track to aid in the transport of documents;
said drum including a reflective substantially cylindrical surface recessed below said outer surface;
a light source and a light sensor;
and
means, including a housing, supporting said light source and said light sensor in positions to enable light from said light source to be reflected from said reflective surface of the drum over a path to energize the light sensor and cause the light sensor to provide an output indicative of the absence of a document from the path adjacent to the drum;
the alignment of said outer surface of said drum relative to the housing enabling light to be reflected from the surface of a document present in the track, adjacent to the drum, over a path which substantially misses the sensor, causing the sensor to provide an output indicative of the presence of a document.

3 more elements

Dependencies are inferred from the claim text.