Patent ID: 7046475
Filing Date: 2006-05-16
Classification: G11B

Abstract:
1. A disk drive having a head which reads data written on a recording surface of a disk, the disk drive comprising: an actuator which supports the head such that the head is movable in a radial direction of the disk; a ramp located away from the recording surface of the disk and having a retract area to which the head is retracted; a speed detector configured to detect a movement speed of the head at predetermined sampling intervals; a seek control device configured to move the head to a particular radial position on the recording surface of the disk before a head unload operation of retracting the head to the retract area of the ramp; a speed feedback control device configured to perform speed feedback control for the head unload operation based on the movement speed of the head detected by the speed detector, the speed feedback control being performed to make the movement speed of the head equal to a target value and executed a pre-specified number of times required to retract the head to the retract area of the ramp; an estimation device configured to estimate a movement distance of the head, the estimation device calculating the estimated movement distance of the head by integrating the movement speed of the head detected by the speed detector; and a head unload operation determining device configured to determine whether the head unload operation has been correctly completed based on a predetermined reference movement distance and the movement distance of the head that is estimated by the estimation device when the speed feedback control has been executed the pre-specified number of times.