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.

Date of Patent:
Aug. 16, 2011

Filed:

Dec. 16, 2009
Applicant:

Minoru Sato, Ota, JP;

Inventor:

Minoru Sato, Ota, JP;

Assignee:
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G11B 7/00 (2006.01);
U.S. Cl.
CPC ...
Abstract

An optical pickup apparatus comprising at least: a diffraction grating configured to split first wavelength light into at least a first main beam and first sub-beam, and to split second wavelength light into at least a second main beam and second sub-beam, the diffraction grating including a diffraction surface portion corresponding to the second wavelength light; and a photodetector including a first main light-receiving unit configured to be applied with the first main beam, a first sub-light-receiving unit configured to be applied with the first sub-beam, a second main light-receiving unit configured to be applied with the second main beam, and a second sub-light-receiving unit configured to be applied with the second sub-beam, a distance between the first main light-receiving unit and first sub-light-receiving unit being changed relative to a standardized distance between the first main light-receiving unit and first sub-light-receiving unit.


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