Patent ID: 6049440
Filing Date: 2000-04-11
Classification: G11B

Abstract:
In a disk drive for storing magnetic information on a disk drive surface, a servo controller for compensating for repetitive runout error in positioning an actuator arm, the actuator arm being attached to a servo positioning motor, the servo controller comprising:a controller for receiving a plurality of servo burst information fields from a read circuit, each of the plurality of servo burst information fields comprising a plurality of offset segments and other information read from a plurality of predetermined locations on the disk drive surface by the read circuit, the controller for controlling writing of at least two servo parameter information fields per servo sector per track to the disk drive surface at a predetermined location, each of the at least two servo parameter information fields per servo sector per track containing predetermined servo information,wherein the at least two servo parameter information fields per servo sector per track are written to the disk drive surface at a predetermined location using independently corrected actuator arm positions derived from the plurality of offset segments,wherein the plurality of offset segments further comprise offset A, B, C, and D burst segments, wherein A and B burst segments are offset in opposite directions from track center by half an intra track distance, C burst segment is offset a full intra track distance so as to be centered on an adjacent track, and D burst segment is centered on the current track with zero offset, andwherein the predetermined servo information comprises gray encoded repetitive runout error correction information for positioning the actuator arm for a subsequent sector.