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. 25, 2007
Filed:
Mar. 20, 2003
Sumitaka Maruyama, Yokohama, JP;
Masahiko Tanaka, Kawasaki, JP;
Hideaki Ohsawa, Yokohama, JP;
Maho Kuwahara, Tokyo, JP;
Akihito Ogawa, Yokohama, JP;
Kazuto Kuroda, Kawasaki, JP;
Sumitaka Maruyama, Yokohama, JP;
Masahiko Tanaka, Kawasaki, JP;
Hideaki Ohsawa, Yokohama, JP;
Maho Kuwahara, Tokyo, JP;
Akihito Ogawa, Yokohama, JP;
Kazuto Kuroda, Kawasaki, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
This invention relates to a focus control apparatus having a controller which generates a control signal and performs focus operation when the peak timing of a focus sum signal based on reflected light and the zero-crossing timing of a focus error signal are detected to substantially coincide with each other in supplying a control signal to a lens actuator driver for supplying a driving signal to a lens actuator for driving a lens. The invention also relates to an optical disk apparatus using the focus control apparatus. By detecting coincidence of the two timings, two reflected waves are discriminated, and stable focus operation is achieved.