Track accessing method and apparatus using coarse and fine driving

Abstract

The invention is directed at ensuring stable track accessing despite the presence of backlash in a pickup drive mechanism, and at providing a precise track accessing operation not affected by the relative position or relative speed between pickup and carriage at the time a track access start instruction is issued. To achieve this, when the track access start instruction is issued in a tracking condition in which the pickup is following a track on a recording medium, the carriage is caused to begin to move in a track access direction by the action of a coarse actuator, while the pickup is still kept on track of the recording medium by means of a fine actuator. When the position of the pickup relative to the carriage has reached a boundary of a switch-off range preset within a movable range of the pickup or moved outside the switch-off range, the track following action of the pickup by the fine actuator is stopped, and the pickup is moved to the target track by using coarse driving control and, as necessary, fine driving control in collaborating fashion.