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. 24, 2012
Filed:
Sep. 13, 2010
Kouhei Anju, Tokyo, JP;
Motoo Aiba, Tokyo, JP;
Kouhei Anju, Tokyo, JP;
Motoo Aiba, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
An objective lens has a numerical aperture of 0.8 or more and focusing a light beam of a wavelength λ of at least 450 nm or less on an optical information recording medium. In this objective lens, a wavefront-aberration deterioration level TOR, accumulative value of aberration deterioration, satisfies the equation (1):=√{square root over (2.5(35)+(35))}{square root over (2.5(35)+(35))}≦0.07[λrms]  (1)In the equation (1), TSA3 [λrms/μm] and TSA5 [λrms/μm] refer to a third-order thickness sensitivity level and a fifth-order thickness sensitivity level, which are generated when a thickness error from a predetermined thickness is +1 μm, respectively. DCm3 and DCm5 refer to a third-order decentering sensitivity level and a fifth-order decentering sensitivity level, which are generated when a decentering error of each of lens surfaces is 1 μm, respectively.