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. 23, 1991
Filed:
Apr. 14, 1989
Yoichi Fukushima, Tokyo, JP;
Minoru Fujita, Tokyo, JP;
Yuji Kakinuma, Tokyo, JP;
Toshio Haga, Tokyo, JP;
Kyodo Printing Co., Ltd., Tokyo, JP;
Abstract
A certification card such as ID card or the like includes a hologram and an optical recording portion. Hologram is such that an amplitude and a phase of a light wave emitted from an object are recorded and an image of the object is rebuilt by emitting light to reproduce of an amplitude and a phase of the thus emmited light. An optical recording technique for use with the card employs data pits which are formed on an optical reflective surface of an optical recording layer. The thus formed data pits are detected by difference in optical reflectivity from the data pits when the object is illuminated by laser beam so that data are read. The card is constituted by adhering a card front substrate to a card rear substrate, and hologram and optical recording portion are formed between the card front substrate and the card rear substrate. The certification card is difficult to falsify and alter and, therefore, has high safety.