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:
Oct. 16, 2007
Filed:
Aug. 11, 2004
Yoshiaki Ukawa, Osaka, JP;
Yoshiaki Ukawa, Osaka, JP;
Funai Electric Co., Ltd., Osaka, JP;
Abstract
A defocus amount specifying circuit specifies, as a focus error minimum defocus amount FMDF, a defocus amount by which the amplitude of a focus error signal becomes minimum in a state in which tracking servo is off in a period after insertion of an optical disc and before a seek operation, and specifies, as a jitter minimum defocus amount JMDF, a defocus amount by which a jitter amount becomes minimum in a state in which tracking servo is on. A defocus amount supplying circuit transmits the focus error minimum defocus amount FMDF to a focus servo circuit to perform focus control during a seek operation, and transmits the jitter minimum defocus amount JMDF to the focus servo circuit to perform focus control after the seek operation.