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. 20, 2002
Filed:
Jan. 20, 2000
Applicant:
Inventors:
Seiji Kajiyama, Gifu, JP;
Youichi Tsuchiya, Hashima, JP;
Kenji Torazawa, Ogaki, JP;
Kouichi Tada, Gifu, JP;
Assignee:
Sanyo Electric Co., Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B 7/24 ; G11B 2/736 ;
U.S. Cl.
CPC ...
G11B 7/24 ; G11B 2/736 ;
Abstract
Micro-pits or micro-pit strings, which are disabled precise copying by means of illegal copying described above and enable signals different from signals of a normal disc to be detected in case of failure in precise copying, are recorded in a copy protected area of an optical disc beforehand. A read unit checks the copy protected area and determines a loaded disc is legal disc or illegally copied disc. If illegal, reading is prohibitted.