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. 21, 2010
Filed:
Feb. 23, 2007
Takashi Kobayashi, Kanagawa, JP;
Katsuhiro Seo, Kanagawa, JP;
Yoshiki Okamoto, Kanagawa, JP;
Noriyuki Kato, Kanagawa, JP;
Takashi Kobayashi, Kanagawa, JP;
Katsuhiro Seo, Kanagawa, JP;
Yoshiki Okamoto, Kanagawa, JP;
Noriyuki Kato, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
An optical pickup for recording or reproducing an information signal in an optical disc includes a light source for emitting a light beam toward the optical disc, an objective lens for focusing the light beam emitted from the light source onto a recording surface of the optical disc, and a photodetector for receiving the light beam reflected by the recording surface of the optical disc and outputting a signal corresponding to an intensity of the received light beam. A spot of the light beam received by the photodetector is asymmetric in both a radial direction and a tangential direction of the optical disc. A lens shift signal for the objective lens is detected by a controller on the basis of the signal output from the photodetector, the controller controlling the objective lens to follow the optical disc.