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.:

US 7639574 B1

PDF
Full Text
Expired
Date of Patent:
Dec. 29, 2009

Filed:

Jun. 24, 2005
Applicant:

Hiroki Nakamura, Osaka, JP;

Inventor:

Hiroki Nakamura, Osaka, JP;

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

An optical pickup including: a monolithic laser light-emitting unit for emitting a first laser beam and a second laser beam having mutually different wavelengths; an one-sided spectrally separating unit for spectrally separating the first laser beam and the second laser beam; a polarizing unit for allowing the laser beam passed through the one-sided spectrally separating unit to be introduced to an optical disk side and for reflecting reflected light from the optical disk; an astigmatism unit for imparting astigmatism to the reflected light; and a photodetecting unit in which a first laser reflected light-receiving portion is arranged in such a manner as to be offset from a second laser reflected light-receiving portion, wherein an optical system is constructed such that a long-axis direction of an ellipse indicating a light spot on the optical disk becomes oblique with respect to a tracking direction.


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Nakamura, Hiroki. (2009). Optical pickup (U.S. Patent No. 7639574). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/7639574

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