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:
Apr. 21, 2009
Filed:
Aug. 20, 2004
Kiyoshi Tateishi, Tsurugashima, JP;
Kazuo Takahashi, Tsurugashima, JP;
Mitsuru Sato, Tokorozawa, JP;
Ichiro Sugai, Tokorozawa, JP;
Kiyoshi Tateishi, Tsurugashima, JP;
Kazuo Takahashi, Tsurugashima, JP;
Mitsuru Sato, Tokorozawa, JP;
Ichiro Sugai, Tokorozawa, JP;
Pioneer Corporation, Tokyo, JP;
Abstract
An optical pickup is provided for preventing an objective lens from colliding with an optical recording medium at the stage of initial adjustments. The optical pickup device comprises a servo circuit, and a lens driver for driving an objective lens. In the servo circuit, a drive signal generator supplies the lens driver with one of a first focus drive signal for moving the objective lens in a direction closer to an information recording layer, and a second focus drive signal for moving the objective lens in a direction away from the information recording layer. A controller in a timing generator switches a signal supplied to the lens driver from the first focus drive signal to the second focus drive signal when the level changes by a predetermined range or more in a servo signal which is generated during a period in which the first focus drive signal is being supplied to the lens driver.