Patent ID: 6995945

Claim:
A head positioning system for positioning a head, which at least reads information from a rotating disk-shaped information recording medium containing at least servo information, to a target head position on the information recording medium, the head positioning system comprising: an actuator including a voice coil motor for moving the head; a position controller for receiving a head position signal which is generated by reading the servo information with the head and indicates the position of the head and a target head position signal which indicates the target head position, generating a position error signal that is a difference between the head position signal and the target head position signal, and outputting a position control signal based on the position error signal; a velocity detector for receiving the head position signal, and detecting or estimating a relative velocity of the head with respect to the information recording medium to output a relative velocity signal that indicates a relative velocity of the head; a counter electromotive voltage detector for detecting a counter electromotive voltage signal of the voice coil motor of the actuator, and estimating an absolute velocity of the head based on the counter electromotive voltage signal to output an estimated head velocity signal; an estimated velocity corrector for correcting an estimation error of the estimated head velocity signal based on the relative velocity signal to output a corrected estimated velocity signal; and an estimation controller for outputting a velocity control signal based on the corrected estimated velocity signal, wherein the actuator is controlled by a control amount signal that is obtained by adding together at least the position control signal and the velocity control signal.