DATA ACQUISITION ELECTRONICS FOR PET MAMMOGRAPHY IMAGING

In an apparatus for reproducing information recorded on a disk having a tracking servo device for an actuator which directs a read beam to a track of the disk, a first power product is applied to the actuator upon turn-off of the tracking servo system, a velocity of the actuator is detected based on an error signal from the tracking servo device, the velocity of the actuator detected immediately after the start of movement of the actuator is stored, on the basis of the detected result, the subsequent velocity of the actuator is sequentially compared with the initial velocity and the velocity is controlled at a constant value until the actuator reaches a predetermined track.