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:
Aug. 17, 2004
Filed:
Aug. 17, 2000
Nobuyoshi Tomita, Tokyo, JP;
Shinji Katsuki, Tokyo, JP;
Hiroshi Saitoh, Saitama, JP;
Takahiro Kusuyama, Saitama, JP;
Sony Corporation, Tokyo, JP;
Abstract
A recording and/or reproducing apparatus for an optical disc having a pit area where data has been recorded and also having a grooved area where data is to be recorded includes an optical pickup, an error signal generating unit, a shift signal generating unit and a servo controller. The optical pickup includes an objective lens for converging a light beam on a signal surface of the optical disc, a photodetector for receiving the light beam reflected from the signal surface and an actuator for moving the objective lens in a direction perpendicular to its optical axis. The shift signal generating unit is responsive to the output signal of the photodetector to generate a lens shift signal corresponding to the amount of shift of the objective lens from its neutral position. The servo controller drives the actuator based on the lens shift signal or the error signal to move the objective lens along the radial direction of the optical disc.