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:
Jul. 17, 2012
Filed:
Jan. 29, 2008
Applicants:
Naoki Yamagata, Tokyo, JP;
Shuichi Takeuchi, Saitama, JP;
Inventors:
Naoki Yamagata, Tokyo, JP;
Shuichi Takeuchi, Saitama, JP;
Assignee:
Hoya Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B 13/18 (2006.01); G02B 3/02 (2006.01);
U.S. Cl.
CPC ...
Abstract
There is provided an objective lens for an optical pick-up. The objective lens is formed to be a single-element plastic lens having a first surface and a second surface. The first surface is configured to have, within an effective diameter, an inflection point at which a second derivative of a sag of the first surface takes a value of 0. Further, the objective lens having a numerical aperture larger than or equal to 0.75.