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:
Mar. 23, 2004
Filed:
Aug. 31, 2000
Shuichi Fukuda, Tokyo, JP;
Sony Precision Technology Inc., Tokyo, JP;
Abstract
A method and an apparatus for measuring eccentricity of the tracks of a disk. The apparatus includes a spindle for driving a turntable carrying a disk, an angle detecting device for detecting the angle of rotation of the spindle, a reproducing head for reproducing information from the disk, a pair of servos for controlling the tracking operation of the head, an eccentricity measuring device for measuring the extent of eccentricity from a signal reproduced by the head, an error detecting device for obtaining a tracking error signal by turning on the tracking servos, and an operation device for determining the direction of eccentricity from the angle of rotation and the tracking error signal, determining a vector quantity of the eccentricity of the tracks from the extent of eccentricity and the direction of eccentricity, and for performing a vector operation to determine the quantity of eccentricity of the tracks.