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:
Mar. 31, 2009
Filed:
Jul. 14, 2005
Hitoshi Ogura, Isesaki, JP;
Tsuyoshi Yamamoto, Ota, JP;
Koji Tsukagoshi, Fukaya, JP;
Hideki Osawa, Fukaya, JP;
Yasushi Hanamoto, Hanyu, JP;
Yasuki Mori, Ora-gun, JP;
Hitoshi Ogura, Isesaki, JP;
Tsuyoshi Yamamoto, Ota, JP;
Koji Tsukagoshi, Fukaya, JP;
Hideki Osawa, Fukaya, JP;
Yasushi Hanamoto, Hanyu, JP;
Yasuki Mori, Ora-gun, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
In an optical disk recording and reproducing device which uses an optical disk having at least a first recording layer and a second recording layer, a thickness of a spacer section between the first recording layer and the second recording layer is measured, an amount of defocus with respect to the second recording layer is set based on the measured spacer thickness, and a focus servo operation is performed for focusing the laser light irradiated from an optical pickup device on the second recording layer.