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:
Jun. 23, 2009
Filed:
Aug. 15, 2006
Hiroshi Mitsuda, Daito, JP;
Hiroshi Mitsuda, Daito, JP;
Funai Electric Co., Ltd., Osaka, JP;
Abstract
In an optical disc apparatus, the amplitude level of a focus error signal for performing focus search is measured, and in order to bring the measured amplitude level of the focus error signal to a target value, gains of focus servo drive amplifiers which amplify respective detection signals from four respective divided detection regions of an optical detector are set as initial values. As a result, the amplitude level of the focus error signal is adjusted at the target value. Next, the amplitude levels of the detection signals from the respective detection regions are measured, and the gains of the respective focus servo drive amplifiers are adjusted individually so that crosstalk can be cancelled based on the measured amplitude levels of the detection signals.