ECCENTRICITY EVALUATION METHOD, SERVO PATTERN WRITER AND MANUFACTURING SYSTEM FOR MAGNETIC DISK DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a servo writer having an eccentricity measuring function capable of easily verifying the centering accuracy of a disk at the time of servo pattern write at a low cost. SOLUTION: A demodulation circuit for reading a servo pattern (track) partially written beforehand (b) in a disk group biased to a spindle hub 4 (a) after centering (c) and converting it to the information of a track position (d) is added to the servo writer. The position information is analyzed, the deviation (eccentricity) in the radial direction of a disk center is obtained by an arithmetic operation, compared with a stipulated value and verified (e) and then a normal servo pattern is written in a centering state where the eccentricity is equal to or less than a prescribed predetermined value. The centering accuracy of matching the center of a magnetic disk medium (disk) and the center of the servo track in the process of writing the servo pattern to the disk group altogether before incorporation to a magnetic disk device is improved. COPYRIGHT: (C)2003,JPO