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:
Feb. 26, 2013
Filed:
Mar. 16, 2009
Tohru Hotta, Nagano, JP;
Ryoichi Kawasaki, Gunma, JP;
Tohru Hotta, Nagano, JP;
Ryoichi Kawasaki, Gunma, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Sanyo Optec Design Co., Ltd., Tokyo, JP;
Abstract
An optical pickup apparatus comprising: a laser diode; an objective lens made of a synthetic resin configured to focus laser light emitted from the laser diode to a signal recording layer of an optical disc; and a collimating lens having a diffraction grating and arranged in an optical path between the laser diode and the objective lens, the collimating lens being so moved in an optical axis direction of the laser light as to correct spherical aberration occurring in response to a change in temperature when performing a recording operation for the optical disc, and the collimating lens correcting by the diffraction grating chromatic aberration occurring when switching from the recording operation to a reproducing operation for the optical disc.