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. 05, 2001
Filed:
Apr. 22, 1998
Hitoshi Terasaki, Gifu, JP;
Shuichi Ichiura, Hashima, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
An optical disk includes a track having a track pitch that is k times (0<k<1) the track pitch of a compact disk format. The track is formed by a pit having a pit length shorter than k times the pit length of the compact disk format. The track pitch P&mgr;m and shortest pit length L&mgr;m are set to satisfy the relationship of L<(A/1.6)×P where A=(V/4.3218)×3 when a standard compact disk having linear velocity of V m/second is compressed. When the recording density is to be increased to two times that of the compact disk, the track pitch is set to approximately 0.9-1.4 &mgr;m, more preferably approximately 1.1-1.3 &mgr;m, and further preferably to approximately 1.2 &mgr;m. Since the track pitch is not compressed as much as the pit length in this optical disk, generation of crosstalk can be suppressed. Also, jitter in a reproduced signal can be suppressed since the track pitch is set to 1.2 &mgr;m or in the vicinity thereof.