OPTICAL DISK DEVICE

PURPOSE:To eliminate the fine positional adjustment of the position sensor of a control track by positioning a carriage base on the differential output between the output of a reference voltage generator that is variable stepwise and the output of the position sensor. CONSTITUTION:Three signals, which are position error signals from the carriage 3, the output of differential amplifier 6 between the position sensor 4 and DAC 5, and the output of the signal generator 8 of the reference speed by which the carriage 3 is moved to the direction of the control track, are switched at MPU 11, inputted in a switch circuit 7, and the position control of the carriage 3 is performed by the carriage position control part 9. Whether or not the control track is present is detected by the reproducing signal from the head in a track detector 10. In this case, in the position sensor 4 of the control track for positioning, there is no need of fine positional adjustment of the position sensor itself.