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. 29, 2008
Filed:
Jun. 29, 2006
Akira Tsukihashi, Gunma, JP;
Shigeru Nakamura, Tokyo, JP;
Misao Kuramochi, Gunma, JP;
Mitsuhiro Hiruma, Gunma, JP;
Michiyoshi Sawada, Gunma, JP;
Hiromitsu Kondo, Tochigi, JP;
Akira Tsukihashi, Gunma, JP;
Shigeru Nakamura, Tokyo, JP;
Misao Kuramochi, Gunma, JP;
Mitsuhiro Hiruma, Gunma, JP;
Michiyoshi Sawada, Gunma, JP;
Hiromitsu Kondo, Tochigi, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
In the optical pickup unit configured to guide a laser beam emitted from a laser source to an objective lens, to converge the laser beam with the objective lens to be irradiated to a disk, and to guide the laser beam reflected and returned by the disk to the photo detector including a light reception region constituted by a plurality of segments, the photo detector is disposed with each amplifier corresponding to each segment of the light reception region, is disposed with each output terminal that outputs each light reception output corresponding to each segment from the photo detector via each amplifier, and is disposed with an output setting circuit that sets each light reception output from each of the output terminals by changing the gain of each of the amplifiers and/or by attenuating the input or output of each of the amplifiers with an attenuator.