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:
May. 01, 2012
Filed:
Jul. 08, 2010
Applicant:
Yukinobu Tanaka, Tokyo, JP;
Inventor:
Yukinobu Tanaka, Tokyo, JP;
Assignee:
Hitachi Consumer Electronics Co., Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
G11B 7/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
An optical disc apparatus for use of an optical disc including a plurality of recording layers sets an amount of correction of spherical aberration for each of the recording layers of the disc during a focus sweep. A photodetector portion produces a signal in response to returned light for each of the recording layers.