The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 10, 1979
Filed:
Dec. 23, 1977
Andrew H McMillan, Wayne, MI (US);
Daniel A Wisner, Milan, MI (US);
Burroughs Corporation, Detroit, MI (US);
Abstract
An apparatus and process for detecting overlapped documents in a document processing apparatus by detecting the translucency of the documents. The disclosed apparatus includes a transport path for guiding documents and drive wheels for moving the documents along the transport path. Four LED (light source) phototransistor (light detector) pairs are located across the transport path. One LED-phototransistor pair is used together with electronics to detect when a document is present. Two LED-phototransistor pairs are used together with edge detection electronics to detect sudden significant changes in document translucency from the immediately previous translucency of the same document as the documents pass thereby. The other LED phototransistor pair is used together with level detect electronics to sample and hold the translucency level at the beginning of each document, and then to detect when the present translucency level of the document exceeds predetermined guardbands on either side of the translucency level at the beginning of the document as the documents pass thereby. Overlap indicating electronics indicates overlapped documents when the outputs of the two edge detects and the level detect are continuously coincident for 1 millisecond, and then the output of the level detect remains continuously present for an additional 5.6 milliseconds.