PURPOSE: To prevent the releasing of a servo lock by dividing kick pulse for moving an optical pickup during a search into plural parts.

CONSTITUTION: An optical pickup 2 is controlled with a radial error signal detector 4 so as to prevent a shift from the equilibrium point, a reproduced address detected with a digital demodulator 8 is compared 10 with a set value 9, and in accordance with the positive or negative difference, kick pulse with positive or negative polarity is formed in a circuit 11. The kick pulse is composed of plural pulses to prevent the releasing of a servo lock.