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:
Sep. 07, 2010
Filed:
Mar. 14, 2007
Osamu Koyama, Hachioji, JP;
Koichiro Nishikawa, Takasaki, JP;
Shinnosuke Torii, Kawasaki, JP;
Chihiro Nagura, Kawasaki, JP;
Haruhiko Horiguchi, Tokyo, JP;
Osamu Koyama, Hachioji, JP;
Koichiro Nishikawa, Takasaki, JP;
Shinnosuke Torii, Kawasaki, JP;
Chihiro Nagura, Kawasaki, JP;
Haruhiko Horiguchi, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
There is provided an optical information recording/reproducing apparatus including a unit for detecting the focus error signal from the reflected light flux from a recording layer of an optical recording medium, and a unit for focusing the light flux on the recording layer of the optical disk on the basis of the focus error signal. In the case of detecting the focus error signal, the light flux of the effective numeric aperture NAeff<1 due to an objective lens and the SIL within a pupil is obtained by a splitting device as the focus error signal, whereby it is possible to suppress the reflected light from the bottom surface of the SIL from being mixed into the focus error signal as a noise.