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:
Jan. 17, 2012
Filed:
Dec. 20, 2010
Kentarou Nakamura, Tokyo, JP;
Eiji Nomura, Tokyo, JP;
Kentarou Nakamura, Tokyo, JP;
Eiji Nomura, Tokyo, JP;
Konica Minolta Opto, Inc., Tokyo, JP;
Abstract
The present invention relates to an objective lens, an objective lens unit and an optical pickup apparatus. The objective lens is provided for an optical pickup apparatus recording or reproducing information by converging a light flux with a wavelength λemitted from a light source onto an information recording surface of an optical information recording medium. The objective lens is formed of: a single lens having at least one aspheric surface. In the objective lens, an effective aperture, a thickness on an optical axis, a focal length, a numerical aperture, and a refractive index satisfy the predetermined conditional expressions. The objective lens unit is provided for an optical pickup apparatus and includes an aberration correcting element and the objective lens.