Patent ID: 6456452
Filing Date: 2002-09-24
Classification: G11B

Abstract:
A disc drive having a disc and an actuator adjacent the disc, the disc having a plurality of nominally concentric tracks, the disc drive providing a servo position error signal indicative of the position of the actuator relative to a selected track, the disc drive further providing a correction signal to adjust the position of the actuator with respect to the selected track in response to the servo position error signal, the disc drive comprising:measurement means for sampling and accumulating data from the servo position error signal over a first complete disc revolution to provide a measurement estimate, the measurement estimate characterizing a repeatable runout signal in the servo position error signal; means for providing a correction estimate; updating means, responsive to the measurement means, for updating the correction estimate with the measurement estimate at the end of the first complete disc revolution to generate an updated correction estimate; summing means, responsive to the updating means, for adding the updated correction estimate to the servo position error signal to provide an adjusted servo position error signal over a second complete disc revolution; and correction means, responsive to the summing means, for determining the correction signal in relation to the adjusted servo position error signal.