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:
Jun. 12, 2012
Filed:
Apr. 11, 2008
Tohru Kimura, Hachioji, JP;
Tohru Kimura, Hachioji, JP;
Konica Minolta Opto, Inc., Tokyo, JP;
Abstract
There are provided an objective lens for an optical pickup device which can record and/or reproduce information on/from an optical disk with high density with the use of a light flux with a short wavelength while keeping a temperature characteristic to be satisfactory in spite of having a plastic objective lens, and the optical pickup device. The objective lens suppresses generation of a spherical aberration even if a temperature change arises, by sacrificing wavelength characteristics and by enhancing temperature characteristics. Such satisfactory temperature characteristics can be acquired by the ring-shaped structure formed as a turning structure on an optical surface of the objective lens, in which the ring-shaped structure includes ring-shaped zones whose number is 3 or more and 30 or less and the ring-shaped structure is formed such that adjoining ring-shaped zones cause a predetermined optical path difference for an incident light flux.