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:
Apr. 10, 2012

Filed:

Feb. 29, 2008
Applicants:

Tohru Hotta, Nagano, JP;

Ryoichi Kawasaki, Gunma, JP;

Kenji Kan, Saitama, JP;

Hiroyuki Shindo, Tokyo, JP;

Inventors:

Tohru Hotta, Nagano, JP;

Ryoichi Kawasaki, Gunma, JP;

Kenji Kan, Saitama, JP;

Hiroyuki Shindo, Tokyo, JP;

Assignees:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B 7/00 (2006.01); G02B 1/10 (2006.01);
U.S. Cl.
CPC ...
Abstract

An optical pickup apparatus comprising: an objective lens configured to focus laser light having the Gaussian distribution properties emitted from a laser diode to a signal recording layer of an optical disc; and an adjustment coating formed on a surface of an incident face of the objective lens on which the laser light is to be made incident, the adjustment coating being configured to adjust transmittance of the laser light passing through the objective lens, the adjustment coating being formed on the surface of the incident face such that the transmittance is lowered as a numerical aperture of the objective lens is reduced.


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