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 8189434 B1

PDF
Full Text
Expired
Date of Patent:
May. 29, 2012

Filed:

Apr. 27, 2005
Applicants:

Osamu Miyazaki, Kyoto, JP;

Keiji Sakai, Nara, JP;

Yukio Watanabe, Kyoto, JP;

Inventors:

Osamu Miyazaki, Kyoto, JP;

Keiji Sakai, Nara, JP;

Yukio Watanabe, Kyoto, JP;

Assignee:
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G11B 7/00 (2006.01); G11B 7/135 (2012.01);
U.S. Cl.
CPC ...
Abstract

An optical pickup device includes: a splitting section for splitting a beam; a light-receiving section for receiving the split beams. The light-receiving section includes: a tracking-use main light-receiving region and tracking-use sub light-receiving regions, and auxiliary light-receiving regions. Each of the auxiliary light-receiving regions receives only a light beam reflected off a recording layer other than a recording layer subjected to an information writing/reading process. A light-receiving area of each of the auxiliary light-receiving area is smaller than a light-receiving area of each tracking-use light-receiving region. Further, an optical pickup device includes: a splitting section for splitting a beam; and a light-receiving section for receiving the split beams. The light-receiving section includes a sub light-receiving regions for receiving tracking-use sub beams. The tracking-use sub beams are arranged so as not to allow entering of a focusing-use main beam reflected off a non-targeted recording layer.


Find Patent Forward Citations

Miyazaki, Osamu. (2012). Optical pickup unit and optical pickup device having same and information writing/reading device having same (U.S. Patent No. 8189434). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/8189434

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