Patent ID: 6392834
Filing Date: 2002-05-21
Classification: G11B

Abstract:
A method of compensating for written-in repeatable run-out in a disc drive having a servo loop for positioning a head relative to a track on a disc surface based on a servo position signal comprising a sequence of servo position values indicative of a position of the head relative to the track comprising steps of:(a) storing a written-in repeatable run-out compensation value in a servo field residing on the track; (b) subtracting the compensation value from a corresponding servo value to obtain a compensated servo value; and (c) positioning the head relative to the track based upon the compensated servo value; and (d) prior to step (a), using a servo device external to the disc drive to position the head over an intended center of the track using laser positioning to determine the written-in repeatable run-out compensation value.