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:
Feb. 28, 2012
Filed:
Oct. 26, 2009
Motoo Aiba, Tokyo, JP;
Kiyoshi Toyota, Tokyo, JP;
Hiroyuki Sakakibara, Tokyo, JP;
Toyokazu Takahashi, Tokyo, JP;
Kouhei Anju, Tokyo, JP;
Kenichi Ogawa, Kanagawa, JP;
Motoo Aiba, Tokyo, JP;
Kiyoshi Toyota, Tokyo, JP;
Hiroyuki Sakakibara, Tokyo, JP;
Toyokazu Takahashi, Tokyo, JP;
Kouhei Anju, Tokyo, JP;
Kenichi Ogawa, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
Provided is an objective lens for which expressions 0.83<(p/p)<1.17 and 0.83<(p/p)<1.17 or expressions 0.80<(p/p)<1.20 and 0.86<(p/p)<1.14 are satisfied, where pis the ratio of fifth-order spherical aberration to third-order spherical aberration, the spherical aberrations being caused by a difference in the thickness of a cover layer of an optical recording medium, pis the ratio of fifth-order spherical aberration to third-order spherical aberration, the spherical aberrations being caused by a change in the temperature of an environment of the objective lens, and pis the ratio of fifth-order spherical aberration to third-order spherical aberration, the spherical aberrations being caused by a change in incident magnification.