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. 07, 2014
Filed:
Mar. 16, 2012
Ryutaro Futakuchi, Osaka, JP;
Shigeru Furumiya, Kyoto, JP;
Ryutaro Futakuchi, Osaka, JP;
Shigeru Furumiya, Kyoto, JP;
Panasonic Corporation, Osaka, JP;
Abstract
An optical disk apparatus has: a laser () that outputs light; an optical system that includes an SIL () for forming a predetermined sized beam spot on an optical disk () using the light from the laser; a detector () that detects output power of the laser and generates a laser power detection signal; a laser power control circuit () that controls the output power of the laser using the laser power detection signal; a detector () that detects a gap length between the optical disk and the SIL and generates a gap detection signal; and a gap control circuit () that controls the gap length between the optical disk and the SIL using the gap detection signal. The power control circuit has a gain crossover frequency greater than a gain crossover frequency of the gap control circuit.