Information storage device with head position detection outside a user utilizable region and an optical disk drive device having target velocity-controlled head actuation

摘要

In a disk drive device comprising an optical head having a movable part including a lens for focusing a light spot on a track of an optical disk and a photodetector which receives the light reflected from the track and provides a photoelectric conversion signal, a head actuator moves the movable part in a radial direction of the optical disk when the optical head accesses the tracks of the optical disk, and a motion detection means receives the photoelectric conversion signal and outputs a track-traverse motion signal representing the track-traverse motion of the light spot. An acceleration detecting means detects the acceleration of the head actuator. A target velocity generating means generates a track-traversing target velocity determined by the output of acceleration detecting means and the photoelectric conversion signal. A state-observer means receives the output signals from the acceleration detecting means and the motion detecting means, and outputs an estimated track-traverse velocity of the light spot. A head actuator drive circuit controls the head actuator such that the estimated velocity coincides with the target velocity.