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. 15, 2011
Filed:
Dec. 17, 2008
Takashi Inoue, Yokohama, JP;
Hiroshi Shimada, Kamakura, JP;
Akira Nakao, Yokohama, JP;
Yasuhiro Hayashi, Yokohama, JP;
Takashi Inoue, Yokohama, JP;
Hiroshi Shimada, Kamakura, JP;
Akira Nakao, Yokohama, JP;
Yasuhiro Hayashi, Yokohama, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
An optical disc drive device has an FE signal generator which generates a focus error signal, a TE signal generator which generates a tracking error signal, a return beam detector which detects a return beam reflected by an optical disc after irradiated by an optical pickup to generate a return beam level signal, a return beam gain setting part which sets amplitude adjustment amount of the return beam level signal so that a signal level of the return beam level signal generated by the return beam detector coincides with a predetermined reference level, an FE gain setting part which sets amplitude adjustment amount of the focus error signal in accordance with the signal level of the return beam level signal adjusted by the return beam gain setting part so that a signal amplitude of the focus error signal is constant, and a TE gain setting part which sets amplitude adjustment amount of the tracking error signal in accordance with the signal level of the return beam level signal adjusted by the return beam gain adjustment part so that a signal amplitude of the tracking error signal is constant.