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FIBER OPTICS CCD DOCUMENT SIZE SENSING

IP.com Disclosure Number: IPCOM000026068D
Original Publication Date: 1990-Feb-28
Included in the Prior Art Database: 2004-Apr-05

Publishing Venue

Xerox Disclosure Journal

Abstract

Measurement of the size of a document placed on a platen is accomplished by the device shown in Figures 1 and 2. Figure 1 shows a top view of a platen cover 10 having rows A and B of optical fibers, each fiber coupled to a photosensor. Row A is used to determine document width and Row B document length. Figure 2 shows a side view of the platen 12, document 14, platen cover 10 and an illumination source 16. The components are shown separated for clarity, but they would ordinarily be in intimate contact. As can be seen from Figure 2, those fibers in Row B behind the document (8-19) will receive less light than fibers 1-7. Therefore, only the diodes associated with fibers 1-7 will provide output signals. Similarly, some fibers in Row A will be blocked from the light by the document depending on its width. The document size is thus determined in two orthogonal directions depending on the illumination reaching the individual diodes.