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. 21, 2012
Filed:
Jan. 13, 2011
Tohru Kimura, Hachioji, JP;
Kiyoshi Yamashita, Hachioji, JP;
Nobuyoshi Mori, Hachioji, JP;
Yuichi Atarashi, Hachioji, JP;
Tohru Kimura, Hachioji, JP;
Kiyoshi Yamashita, Hachioji, JP;
Nobuyoshi Mori, Hachioji, JP;
Yuichi Atarashi, Hachioji, JP;
Konica Minolta Opto, Inc., Tokyo, JP;
Abstract
An optical system for use in an optical pickup apparatus comprises a first optical surface having a superposition type diffractive structure including a plurality of ring-shaped zones which are formed concentrically around an optical axis, wherein each ring-shaped zone is composed of a plurality of stepped sections stepwise, and a second optical surface having a diffractive structure including a plurality of ring-shaped zones which are formed concentrically around an optical axis, wherein each of the plurality of ring-shaped zones are divided by a stepped section to generate a diffractive light ray of diffractive order whose absolute value is not small than 1 for the light flux.