if the measured time does not exceed the predetermined time s17 is performed if s18 determines that the disc motor 33 is driven at the high rotational speed and also s19 determined that the measured time exceeds the predetermined time it is determined that the servo polarity set in the pickup servo circuit 47 does not correspond to the current reading region of the optical disc 32 accordingly s20 causes the servo polarity of the tracking control operation set in the pickup servo circuit 47 to be inverted then s11 performs the fg servo control operation thus the cpu 41 operates the servo change over switch circuit 45 to select the b terminal and thus the cpu 41 is connected to the driving circuit 48 when the fg servo control operation is finished in s12 the cpu 41 operates the servo change over switch circuit 45 to select the a terminal and thus the disc servo circuit 39 is connected to the driving circuit 48 thus the clv servo control operation is performed from s13 until the clv servo locked state is realized even in a case other than the initial state when the clv servo control operation is attempted to be performed after a state in which the disc motor 33 is not rotated yes is a result of s10 and thus the fg servo control operation is first performed in s11 and after the current rotational speed of the disc motor 33 coincides with the.