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. 26, 1997
Filed:
Mar. 21, 1996
Applicant:
Inventors:
Mineo Moribe, Kawasaki, JP;
Haruhiko Izumi, Kawasaki, JP;
Masakazu Taguchi, Kawasaki, JP;
Iwao Tsugawa, Kawasaki, JP;
Assignee:
Fujitsu Limited, Kawasaki, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ; G11B / ;
U.S. Cl.
CPC ...
369 14 ; 369 58 ;
Abstract
An optical recording medium in which a medium identification code is recorded by using a nonvolatile mark which is formed through irreversible change of a recording film, such as magnetization characteristic change, deformation and formation of a hole, so as to prevent illegal copy of the optical recording medium, and a recording/reproducing method for the same.