Patent ID: 7038877

Claim:
A head positioning apparatus, comprising: a magnetic head for recording/reproducing information on a rotary recording medium; a head support mechanism provided swingably on the recording medium while supporting the magnetic head; a coarse actuator for swinging the head support mechanism for coarsely positioning the magnetic head on the recording medium; a fine actuator provided in the head support mechanism for precisely positioning the magnetic head on the recording medium; a head position detector for detecting the head position representing the position of the magnetic head; and a fine movement control system for controlling the fine actuator based on the head position detected by the head position detector, the head positioning apparatus further comprising: a head moving distance estimator for estimating a head moving distance representing a distance the magnetic head moves based on VCM Back EMF voltage generated in the coarse actuator; and a coarse movement control system for controlling the coarse actuator based on the head moving distance estimated by the head moving distance estimator; wherein the head moving distance estimator comprises a head absolute speed estimator for estimating a head absolute speed representing the absolute speed of the magnetic head based on the VCM Back EMF voltage; and a coarse movement distance estimator for estimating the head moving distance based on the head absolute speed estimated by the head absolute speed estimator; wherein the fine movement control system comprises a fine movement controller for generating the control signal for controlling the fine actuator based on the head position detected by the head position detector; and further comprises a fine movement head moving distance estimator for estimating the fine movement head moving distance representing the amount that the magnetic head is moved by the fine actuator based on the control signal generated by the fine movement controller; and wherein the coarse movement moving distance estimator estimates the head moving distance by defining the coarse movement head moving distance representing the amount that the magnetic head is moved by the coarse actuator, which is obtained by subtracting the fine movement head moving distance estimated by the fine movement head moving distance estimator from the head position detected by the head position detector, as an initial value.