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. 27, 2008
Filed:
Dec. 07, 2004
Takeshi Shimamoto, Osaka, JP;
Shin-ichi Yamada, Osaka, JP;
Shin-ichi Kadowaki, Hyogo, JP;
Yuuichi Kuze, Osaka, JP;
Kenji Kondo, Osaka, JP;
Katsuya Watanabe, Nara, JP;
Takeshi Shimamoto, Osaka, JP;
Shin-ichi Yamada, Osaka, JP;
Shin-ichi Kadowaki, Hyogo, JP;
Yuuichi Kuze, Osaka, JP;
Kenji Kondo, Osaka, JP;
Katsuya Watanabe, Nara, JP;
Matsushita Electric Industrial Co., Ltd., Kadoma, JP;
Abstract
An optical disc apparatus includes a control section. The control section performs a first search while the tracking control is in the off state. The first search is for searching for a plurality of sets of the focus positions of the light beam and the spherical aberration amounts such that an amplitude of the tracking error signal is greater than a predetermined value. The control section performs a second search while the tracking control is in the on state. The second search is for determining a set of the focus position of the light beam and the spherical aberration amount such that the reproduced signal quality index is substantially optimal, among the plurality of sets of the focus positions of the light beam and the spherical aberration amounts obtained in the first search.