DETECTING DEVICE OF EXISTENCE, AND RIGHT AND WRONG SIDE OF OPTICAL DISK

PURPOSE:To detect the existence, and the right and the wrong side of an optical disk by simple constitution consisting of few parts, by executing the detection based on an output signal of a rotation detector and an output signal of a signal processing device. CONSTITUTION:When a one face recording optical disk 11 does not exist, a driving motor 13 executes hunting, an output signal of a rotation detector 14 corresponding to the hunting is applied to a logical arithmetic unit 19 to which an output signal of a signal processing device 18 for processing a signal from an optical pickup 16 is supplied, and it is detected that the disk 11 does not exist. On the other hand, in case when the disk 11 is the rear side, the output signal supplied to the device 19 from the device 18 becomes irregular and the rear side is detected. In this way, an exclusive detecting device is not required, and by a simple constitution whose number of parts is small, the existence and the rear side of the optical disk can be detected.