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:
May. 17, 2005
Filed:
Jun. 15, 2000
Hiroshi Shimada, Kamakura, JP;
Hiroshi Shimada, Kamakura, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
Information is extracted from a track by a pickup during rotation of an optical disk, the output of the pickup is supplied to a head amplifier to generate an information signal including disk record information and a tracking error signal, and a reading-out speed is detected from the information signal from the head amplifier. The frequency component which is near the rotation frequency of the disk within the range of the change in the reading-out speed of the information is extracted from the detected reading-out speed signal, an eccentricity signal showing a position deviation between the center point of the track of the disk and the rotation center point of the disk is output from a band-pass filter, the output of the filter is substantially added to the output of the tracking control circuit, and a tracking actuator is driven and controlled to correct a tracking error.