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. 30, 2011
Filed:
Nov. 18, 2008
Applicants:
Toshiaki Katsuma, Saitama, JP;
Masao Mori, Saitama, JP;
Tetsuya Ori, Saitama, JP;
Yu Kitahara, Saitama, JP;
Inventors:
Toshiaki Katsuma, Saitama, JP;
Masao Mori, Saitama, JP;
Tetsuya Ori, Saitama, JP;
Yu Kitahara, Saitama, JP;
Assignee:
Fujinon Corporation, Saitama-Shi, Saitama, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B 7/135 (2006.01);
U.S. Cl.
CPC ...
Abstract
An objective lens consists of a single lens element. A light source side surface is formed into a convex surface having a large curvature, and an optical recording medium side surface has a small curvature. The both surfaces are formed into aspheric surfaces. Also, the objective lens satisfies the following expressions (1) to (3):0.70<NA<0.98  (1)0.70<d/f<3.00  (2)0.50<<0.80  (3)