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:
Mar. 22, 2011
Filed:
Sep. 13, 2006
Akihiro Arai, Kyoto, JP;
Takeharu Yamamoto, Osaka, JP;
Akihiro Arai, Kyoto, JP;
Takeharu Yamamoto, Osaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
An optical disc drive includes: an optical branching element for splitting light from a light source into main and sub-beams; a condenser element for condensing the main and sub-beams; a photodetector section including photodetectors to receive reflected portions of the main and sub-beams, each photodetector having photosensitive areas, each of which outputs a signal representing the intensity of light received there; and a computing section for generating a first focus signal, representing where the focal point of the main beam is located with respect to the storage layer, based on the reflected light of the main beam, and a second focus signal based on the reflected light of the main and sub-beams.