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:
Jun. 12, 2007
Filed:
Oct. 30, 2001
Eiji Muramatsu, Tokorozawa, JP;
Toshihiko Takishita, Yamanashi-ken, JP;
Masahiro Kato, Tokorozawa, JP;
Yoshio Sasaki, Tokorozawa, JP;
Haruyasu Sakata, Tokorozawa, JP;
Eiji Muramatsu, Tokorozawa, JP;
Toshihiko Takishita, Yamanashi-ken, JP;
Masahiro Kato, Tokorozawa, JP;
Yoshio Sasaki, Tokorozawa, JP;
Haruyasu Sakata, Tokorozawa, JP;
Pioneer Corporation, Tokyo-To, JP;
Abstract
A rewritable type optical disc includes recording tracks formed with break portions; and recording marks corresponding to predetermined data and formed on the recording tracks. The recording marks are formed over the break portions on the recording tracks. If the predetermined data, such as control data, recorded as the recording mark is illegally altered, the position of the recording marks are changed and some break portions are not covered by the recording marks. Since the return light level of the break portion, which is not covered by the recording mark, is different from the return light level of the break portion covered by the recording mark, such illegal alteration of the predetermined data such as the control data may be detected.