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:
May. 31, 1988
Filed:
Jul. 25, 1986
David G Gold, Santa Monica, CA (US);
Vahakn K Gharibian, Los Angeles, CA (US);
Light Signatures, Inc., Los Angeles, CA (US);
Abstract
A system for sensing a characteristic of a document, e.g. translucency, by using radiation from the document at a specific window area. The identified window area is illuminated to provide radiation from the area which is sensed by pixel dissection so that pixels of central location in the window area are weighted for greater significance. The pixel weighting attributes greater significance to the central portion of the defined area thereby increasing the tolerance of the system to misalignment of the window area. The observed characteristic is reduced to signal representations which are compared with registered values as to authenticate the document. Pixel-weighting techniques include overlapped pixels, filtered pixels and algebraically weighted pixels.