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:
Aug. 20, 2002
Filed:
May. 17, 2000
Applicant:
Inventors:
Assignee:
Sharp Kabushiki Kaisha, Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B 7/00 ;
U.S. Cl.
CPC ...
G11B 7/00 ;
Abstract
In an optical pickup device, the numerical aperture (NA) of an objective lens is set at 0.7 or more, and the ellipticity of polarized light of a light beam which is incident upon the objective lens is set to be larger than (1.4×NA)−0.7. According to the structure, an optical pickup device which can prevent deterioration of the jitter and crosstalk characteristics, for example, due to oval deformation of a beam spot can be provided.