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:
Oct. 04, 2011
Filed:
Sep. 19, 2006
Optical information recording medium, bca information recorder, and bca information recording method
Shuichi Ohkubo, Tokyo, JP;
Shuichi Ohkubo, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
Multilayered optical information recording media involve a problem that a BCA is erroneously formed in a different information recording layer even if the BCA is intended to be formed in a specific information recording layer. An optical information medium () for recording/reproducing information by applying a laser beam includes two or more recording layers () for recording/reproducing information by receiving a laser beam at the same laser beam incident surface (). A geometrical irregularity (K) is formed in an area (inner peripheral side) () for a BCA on one recording layer (), and a mirror surface is formed in the area of the other information recording layer () corresponding to the BCA area (). The geometrical irregularity (K) is detected when focus servo is actuated so as to detect the desired information recording layer. Thus, a BCA is prevented from being erroneously formed in another information recording layer.