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:
Apr. 28, 1987
Filed:
Sep. 21, 1983
Applicant:
Inventor:
Karl H Knop, Zurich, CH;
Assignee:
RCA Corporation, Princeton, NJ (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06K / ;
U.S. Cl.
CPC ...
382-1 ; 235380 ; 235487 ; 235494 ; 283 74 ; 34082534 ; 35016220 ; 356 71 ;
Abstract
A random-pattern of microscopic lines that inherently forms in a dielectric coating layer of a 3-layer diffractive subtractive filter authenticating device incorporated in a secure document permits identification of a genuine individual document by comparing read-out line-position information derived by microscopic inspection with read-out digital codes of line-information obtained earlier at the time of fabrication of the document. The technique can also be used with an artificially generated random pattern of lines in the case of other types of authenticating devices that do not inherently form such a pattern.