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:
Jan. 01, 2013
Filed:
Aug. 31, 2010
Kenji Nagatomi, Kaizu, JP;
Kenji Nagatomi, Kaizu, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
An optical pickup device includes an objective lens portion which converges laser light at a first focal point and a second focal point; an actuator which positions the first focal point or the second focal point on a recording layer in a disc; an astigmatism element which sets a first focal line position and a second focal line position of the laser light reflected on the disc away from each other in a propagating direction of the laser light; a spectral element which disperses four light fluxes obtained by dividing the laser light reflected on the disc in four from each other; and a photodetector having a sensor group which receives the four light fluxes dispersed by the spectral element.