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:
Aug. 25, 1981
Filed:
Aug. 09, 1979
Samuel Ben-Nathan, Waterloo, CA;
Marwin G Neumeister, Kitchener, CA;
Mikhail Shats, Waterloo, CA;
Robert S McCallum, Erin, CA;
NCR Canada Ltd - NCR Canada Ltee, Mississauga, CA;
Abstract
Method and means are disclosed for detection of overlapped sheets transported along a path. A plurality of detection means are aligned substantially perpendicular to the direction of movement of said sheets, each detection means including one or more radiation sources and one or more radiation detectors. The overlapping of one sheet by another produces a shadow on the surface of the overlapped sheet along the edge of the overlapping sheet when radiation is directed obliquely on to the sheets from one of said radiation sources, the direction of such radiation necessary to produce a shadow being dependent on the direction of the overlap of one sheet by another. Reflected radiation from the sheets is received by one or more of the radiation detectors, and shadows or marks on the sheets are detected by reason of their lower reflectivity. Shadows indicating overlapped edges are distinguished from marks on the sheets by logic circuitry which signifies the presence of an overlap when one but not both of two samplings of the radiation detectors of all the radiation means shows a decrease in reflectivity.