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. 02, 2013
Filed:
Apr. 08, 2008
Kentarou Nakamura, Hachioji, JP;
Tohru Kimura, Hachioji, JP;
Kentarou Nakamura, Hachioji, JP;
Tohru Kimura, Hachioji, JP;
Konica Minolta Opto, Inc., Tokyo, JP;
Abstract
There are provided an optical pickup device which can satisfactorily record and/or reproduce information on different kinds of optical information recording medium in spite of compactness, and an objective optical element used for the optical pickup device. The optical functional surface of the objective optical element includes at least two areas of a central area including an optical axis and a peripheral area surrounding the central area. An optical path difference providing structure in the central area is a structure obtained by overlapping a first central basic structure and a second central basic structure which are in a shape of ring-shaped zones divided by step differences, with each other. An optical path difference providing structure in the peripheral area is a structure obtained by overlapping a first peripheral basic structure and a second peripheral basic structure which are in a shape of ring-shaped zones divided by step differences, with each other.