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:
Feb. 21, 2012
Filed:
Jul. 28, 2006
Akira Yoshikawa, Nara, JP;
Kenji Kondo, Osaka, JP;
Akira Yoshikawa, Nara, JP;
Kenji Kondo, Osaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
An optical disk drive includes: an objective lens for converging a light beam onto an optical disk with an information storage layer; an actuator for moving the lens perpendicularly to the storage layer; an actuator driver for moving the lens at a predetermined velocity by controlling the actuator's operation; and a disk position detector for detecting the position of the lens, when the focal point of the beam is located on the storage layer, as a disk position. While the lens is being moved toward the disk to perform a focus finding operation, the moving velocity of the lens is set high until the lens reaches a velocity switching point, determined by reference to the disk position, and is set low once the lens has passed the point. The switching point is set farther away from the disk than the position of the lens is when the focal point of the beam is located on the storage layer of the disk.