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:
Dec. 03, 2013
Filed:
Aug. 31, 2012
Motoo Aiba, Tokyo, JP;
Hiroyuki Sakakibara, Tokyo, JP;
Taiji Minakawa, Tokyo, JP;
Fumihiko Hanzawa, Tokyo, JP;
Masashi Abe, Tokyo, JP;
Jun Adachi, Tokyo, JP;
Katsutoshi Sato, Tokyo, JP;
Motoo Aiba, Tokyo, JP;
Hiroyuki Sakakibara, Tokyo, JP;
Taiji Minakawa, Tokyo, JP;
Fumihiko Hanzawa, Tokyo, JP;
Masashi Abe, Tokyo, JP;
Jun Adachi, Tokyo, JP;
Katsutoshi Sato, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
Provided is an objective lens including a diffraction portion provided on a laser beam incident plane or output plane. The diffraction portion includes first second, and third diffraction regions, wherein first laser beams corresponding to a first optical disc having a first transmissive layer are condensed on a data recording portion of the first optical disc, second laser beams corresponding to a second optical disc having a second transmissive layer thicker than the first transmissive layer are condensed on a data recording portion of the second optical disc, and third laser beams corresponding to a third optical disc having a third transmissive layer thicker than the second transmissive layer are condensed on a data recording portion of the third optical disc. An evaluation parameter calculated on the basis of an in-plane efficiency distribution function has a value corresponding to a symbol error rate that is less than a predetermined value.