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:
Apr. 23, 2013
Filed:
Feb. 22, 2011
Motohiro Inoue, Tokyo, JP;
Takashi Kikukawa, Tokyo, JP;
Atsuko Kosuda, Tokyo, JP;
Hideki Hirata, Tokyo, JP;
Motohiro Inoue, Tokyo, JP;
Takashi Kikukawa, Tokyo, JP;
Atsuko Kosuda, Tokyo, JP;
Hideki Hirata, Tokyo, JP;
TDK Corporation, Tokyo, JP;
Abstract
Efficient recording and reading are achieved in an optical recording medium including servo layers and recording and reading layers. The optical recording medium includes: a first servo layer having a projection and a depression for tracking control that are formed in a first spiral direction; a second servo layer having a projection and a depression for tracking control that are formed in a second spiral direction opposite to the first spiral direction; and a plurality of recording and reading layers having a flat structure with no projection and depression for tracking control. Information is recorded on each of the plurality of recording and reading layers while tracking control is performed using the first servo layer or the second servo layer.