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:
Apr. 28, 2009
Filed:
Dec. 01, 2005
Kenji Nagatomi, Gifu, JP;
Seiji Kajiyama, Gifu, JP;
Kenji Nagatomi, Gifu, JP;
Seiji Kajiyama, Gifu, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
Provided is an optical pickup device in which the deterioration of optical characteristics of a laser light beam due to a deviation of an optical axis can be smoothly suppressed with a simple structure. An objective lens becomes a finite system for only a laser light beam for CD (780 nm in wavelength). A three-wavelength laser is disposed such that an optical axis of the laser light beam for CD is aligned with an optical axis of an optical system including a polarization BS to an optical axis correcting element. In this case, the large deterioration of the optical properties of the laser light beam for CD, which cannot be sufficiently compensated even if the objective lens is tilted, does not occur. A stable recording and reproducing operation using the laser light beam for CD can be performed. At this time, although an optical axis of a laser light beam for DVD and an optical axis of a laser light beam for next-generation DVD are deviated from an optical axis of the optical system, the laser light beams are incident on the objective lens as infinite system light beams, so the deterioration of the optical properties due to the deviation can be suppressed by tilting the objective lens.