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:
Jan. 13, 2009
Filed:
Dec. 08, 2005
Minoru Yonezawa, Tokyo, JP;
Yuichiro Yamamoto, Tokyo, JP;
Minoru Yonezawa, Tokyo, JP;
Yuichiro Yamamoto, Tokyo, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
An optical disk apparatus includes an objective lens that condenses light on an information recording layer of an optical disk that has a first area with a first track pitch and a second area with a second track pitch, to form an optical spot. The apparatus also includes a tilt driver that inclines the objective lens; a positioning unit that positions the optical spot on a target track; a position error detector that detects a position error of the optical spot from the target track; a tilt detection correcting unit that calculates a tilt error signal based on a first position error detected when the optical spot is positioned on a target track in the first area and a second position error detected when the optical spot is positioned on a target track in the second area; and a tilt controller that controls an inclination based on the tilt error signal.