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:
Mar. 06, 2012
Filed:
Oct. 15, 2007
Applicants:
Kenji Narumi, Osaka, JP;
Masahiro Birukawa, Osaka, JP;
Inventors:
Kenji Narumi, Osaka, JP;
Masahiro Birukawa, Osaka, JP;
Assignee:
Panasonic Corporation, Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B 7/135 (2012.01); G11B 7/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
A distance control circuit keeps constant the distance between a condensing member and the surface of an optical disk using return light from a region where near field light is generated. Additionally, a focus control circuit controls the focus position of the near field light to sustain it at the position of an information layer using reflection light from the information layer.