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:
Sep. 08, 2009
Filed:
May. 27, 2005
Kenji Fujiune, Osaka, JP;
Yuuichi Kuze, Osaka, JP;
Katsuya Watanabe, Nara, JP;
Panasonic Corporation, Osaka, JP;
Abstract
The purpose is to provide an optical disc apparatus which can accurately calculate a gain for focus control. An optical apparatus () includes: an FE generator () for generating an FE signal; an AS generator for generating an AS signal (); a normalization operator (); an Fc filter (); a selector (); a spherical aberration setting device (); an FE amplitude measuring device (); an Fc pull-in instructor (); an after-pull-in AS measuring device (); and a gain operator (). The optical apparatus obtains an amplitude of the FE signal before the focus is pulled in, and obtains a level of the AS signal after the focus is pulled in to adjust a focus gain.