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:
Jul. 01, 2003
Filed:
Jun. 03, 1999
Ken'ichi Nagata, Nishinomiya, JP;
Noboru Yamada, Hirakata, JP;
Nobuo Akahira, Yawata, JP;
Kenichi Nishiuchi, Hirakata, JP;
Matsushita Electric Industrial Co., Ltd., Kadoma, JP;
Abstract
Tracking control is carried out by a push-pull method or by mechanical feed at the time of recording signals, and tracking control is carried out by a phase difference tracking method at the time of reproduction. Thus, a phase change type optical disk which enables phase difference reproduction and is erasable may be realized. In a phase change type optical disk having a phase difference reproduction structure, servo mechanism at the time of reproducing signals may be stably controlled by causing the reflectance of a blank portion to be higher than the reflectance of a recording mark portion.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile