PURPOSE: To perform quick lock-in stably with a simple constitution, by operating the 1st and 2nd control means with a low and a high frequency component of a phase comparison output between a reference and a reproduced synchronizing signal.

CONSTITUTION: A phase comparator 26 makes phase comparison between a reference synchronizing signal and a synchronizing signal in a reproduced signal. A signal of the phase comparator 26 is transmitted to a delay circuit 21 via a control circuit 31 and the amount of delay of a delay circuit 21 is controlled only as to a signal of a low frequency component out of the signals of the phase comparator 26. The high frequency component of signals of the phase comparator 26 can be compensated by moving an optical beam 2 to a record disc 7.