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:
May. 15, 2012
Filed:
Sep. 19, 2008
Yasuhiro Tanaka, Hyogo, JP;
Michihiro Yamagata, Osaka, JP;
Katsuhiko Hayashi, Nara, JP;
Masahiro Birukawa, Osaka, JP;
Yasuhiro Tanaka, Hyogo, JP;
Michihiro Yamagata, Osaka, JP;
Katsuhiko Hayashi, Nara, JP;
Masahiro Birukawa, Osaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
An optical system for optical pickup, which optical system is used for performing recording, reproducing, and/or erasing of information on an optical recording medium and has a simple configuration, is provided. An optical pickup deviceincludes a collimator lens system, a beam expander, and an objective lens systemthat includes an S-SIL element. The beam expanderincludes three lens elementsto. By moving in an optical axis direction, the two lens elementsandincluded in the beam expanderadjust a focal point of a spot formed within an optical recording medium, and compensate a spherical aberration caused by the difference in depth between recording layers.