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:
Mar. 01, 2005
Filed:
Sep. 26, 2001
Hiroyuki Sakakibara, Tokyo, JP;
Hiroyuki Ueda, Kanagawa, JP;
Hiroyuki Sakakibara, Tokyo, JP;
Hiroyuki Ueda, Kanagawa, JP;
Sony Corporation, , JP;
Abstract
Providing an objective lens capable of achieving reliable centering during formation, allowing high-precision formation, and improving durability of a manufacturing apparatus, and providing an optical pickup apparatus and an optical disk apparatus using that objective lens. According to the present invention, an objective lens is formed so as to satisfy condition 0.3≦Z/D≦0.5, where Z is a sag amount equivalent to a length of a convexly curved optical surface along an optical axis, and D is an optically effective diameter equivalent to a length which is optically effective for the optical surface and is orthogonal to the optical axis. It is possible to reliably perform centering during fabrication of the objective lens and allow high-precision formation for decreasing the lens aberration.