An actuator supports a head at one end of a rotatably supported shaft unit
and supports a coil of a voice coil motor at the other end, and moves the
head to an arbitrary track position of a recording medium. A sensor,
attached to a coil support unit of the actuator, detects the coil
vibration and outputs a vibration detected signal. A control unit
controls the actuator to reduce a head position error signal based on the
vibration detected signal of the sensor in time of seek and in time of
settling of moving the head to a target track position on the medium
through drive of the actuator and drawing the same. The vibration
detected signal of the sensor includes bending vibration component of the
coil and the twisting vibration component of the coil when the actuator
is driven.