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. 02, 2010
Filed:
Nov. 15, 2005
Eishin Mori, Kyoto, JP;
Akihiro Arai, Kizu-cho, JP;
Fumitomo Yamasaki, Nara, JP;
Joji Anzai, Minoh, JP;
Eishin Mori, Kyoto, JP;
Akihiro Arai, Kizu-cho, JP;
Fumitomo Yamasaki, Nara, JP;
Joji Anzai, Minoh, JP;
Panasonic Corporation, Osaka, JP;
Abstract
An optical head that is restrained from becoming larger, even if it is used for an optical-information recording medium that includes a plurality of information recording layers. In this optical head, a collimating lens is formed by a concave lens disposed on the side of a light source and a convex lens disposed on the side of an objective lens. A collimating-lens actuator moves the convex lens in a direction where a spherical aberration is cancelled which is generated according to the thickness of a light transmission layer up to an information recording layer of the optical-information recording medium. An aperture stop is provided on the side of the collimating lens with respect to the objective lens, and the aperture stop is located near the focal position of the convex lens on the side of the objective lens.