Writing manner null of servo track/truck lighter/writer and servo

摘要

PROBLEM TO BE SOLVED: To improve the uniformity of interval between servo tracks by measuring a position deviation value in the radial direction of a disc to write a servo signal positioning a head so that the position deviation value non-synchronous with rotation is corrected. ;SOLUTION: A reference signal which is written onto a circumference of a magnetic disc at a fixed pitch is reproduced and a time difference 16 between reproduction pulse outputs of a main reference head 2 and a sub reference head 3 arranged symmetrically with respect to the center of the magnetic disc is outputted by a time difference ditecting part 11 to make the magnetic disc rotate a plurality of times. Thus, an average time difference is obtained by averaging the time differences 16 to determine a position deviation value non- synchronous with the rotation of the magnetic disc from a relationship between the average time difference 17 and the time difference 16.;COPYRIGHT: (C)1997,JPO