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. 23, 2005
Filed:
Mar. 07, 2003
Tetsuya Akiyama, Hirakata, JP;
Kenichi Nishiuchi, Hirakata, JP;
Tetsuya Akiyama, Hirakata, JP;
Kenichi Nishiuchi, Hirakata, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An optical information recording medium includes: a substantially disk-shaped substrate; and a recording layer formed on a surface of the substrate for recording, reproducing and erasing information by irradiation with a laser beam. A test recording region for test recording and an information recording region for recording the information at least are arranged on the surface of the substrate. In the test recording region and the information recording region arranged on the surface of the substrate, a test recording track and an information recording track respectively are formed in a spiral-shaped arrangement or in a concentric arrangement. A track pitch of the test recording track is wider than a track pitch of the information recording track.