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:
Mar. 27, 2007
Filed:
Jun. 02, 2003
Masaru Yamaoka, Osaka, JP;
Takashi Yumiba, Kyotanabe, JP;
Takahiro Nagai, Osaka, JP;
Hideshi Ishihara, Katano, JP;
Masaru Yamaoka, Osaka, JP;
Takashi Yumiba, Kyotanabe, JP;
Takahiro Nagai, Osaka, JP;
Hideshi Ishihara, Katano, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An optical disk is provided that disables reproduction of sub-information even if the sub-information as a contents encryption key is recorded entirely onto another optical disk. Sub-information is recorded on the optical disk by deforming a recording mark slightly in accordance with a pseudo random number sequence that is obtained using as an initial value medium ID that is read out medium inherent information. This allows sub-information inherent in a medium to be recorded, and even if the sub-information is duplicated entirely to another optical disk, the illegally duplicated sub-information cannot be reproduced because of a difference in initial value of a pseudo random number sequence between media.