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. 05, 2005
Filed:
Sep. 30, 2003
Applicants:
Ikuo Nakano, Kashihara, JP;
Eiji Yamada, Tenri, JP;
Inventors:
Ikuo Nakano, Kashihara, JP;
Eiji Yamada, Tenri, JP;
Assignee:
Sharp Kabushiki Kaisha, Osaka, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B003/02 ; G02B013/18 ; G11B007/00 ;
U.S. Cl.
CPC ...
Abstract
An optical recording/reproducing apparatus is arranged so that, upon recording or reproducing a recording medium having a plurality of recording layers, the gap of the lens groups at the time of forming a converged light spot on this first recording layer is DIS(), the gap of the lens groups at the time of forming the converged light spot on the N-th layer (the farthest layer from the surface of the recording medium) is DIS(N) and the neutral point of the spherical-aberration correcting mechanism is set at a position satisfying the following expression: lens group gap dst()=((DIS ()+DIS(N))/2.