Patent ID: 6903896

Claim:
A head positioning method for positioning a head with respect to a disk by using an actuator including a voice coil motor, an arm fixed to the voice coil motor, and the head attached to the arm, the method comprising the steps of: producing a disturbance compensation signal by estimating a magnitude of disturbance acting upon the actuator based on a driving signal for driving the actuator and a voltage signal indicating a voltage that is generated across the voice coil motor according to driving of the actuator; producing a control signal by multiplying the disturbance compensation signal by a gain adjustment coefficient, which is a constant other than 1 or a variable that takes a value other than 1 at any point in time; calculating a head position error based on a target position and a head position that is obtained by detecting, with the head, servo information recorded in advance on the disk, so as to produce a position control signal corresponding to the head position error; and producing the driving signal by adding together the control signal and the position control signal.