| 摘要 |
PROBLEM TO BE SOLVED: To enable a test without requiring a special jig and increasing facility expense and a required tine by obtaining a reproduced signal in which an optical track eccentric to the rotation center of a disk and consisting of stitch of a concentric circle type is formed and which is obtained by rotating a disk while keeping a magnetic head carriage fixed as the same signal as a signal in the case of actual seek. SOLUTION: Continuous stitches 8 are formed on a test disk 10 in a concentric circle type centered on an eccentric point 7 apart from a rotation center point O by a fixed distance (quantity of eccentricity X). The continuos stitches 8 are formed by scratching a surface of the disk. When an optical head is tested using a test disk 10, a magnetic head carriage is fixed at the prescribed position in the direction of a radius of a disk by rotating the disk 10. Positions of the stitches 8 are varied successively in accordance with a rotation angle of the test disk 10 by effect of quantity of eccentricity X. The optical head is moved in the direction of seeking the magnetic head carriage by eccentric rotation of the stitches 8. |
