PURPOSE: To stably perform the pull-in of a track at the time of performing multitrack jump by counting the number of traverse on the track based on the output of a comparator provided with hysteresis levels.

CONSTITUTION: A tracking error signal outputted repeatedly at every traverse of a light beam on the track at the time of performing the multitrack jump is inputted to the inversion terminal of an operational amplifier C1 in which the positive feedback of output is issued to the non-inversion terminal, and is compared with upper and lower voltages set at deep hysteresis levels by the positive feedback. When the tracking error signal exceeds the upper hysteresis level, the output of the amplifier C1 goes to L, and that of an inverter C2 goes to H until the tracking error signal goes less than the lower hysteresis level, thereby, the tracking error signal is arranged to a binary pulse not being affected by a noise. The binary pulse is counted by a counter, and the number of traverse on the track goes to an accurate value not being affected by the noise, therefore, it is possible to perform the pull-in of the track stably at the time of performing the multitrack jump.