| 摘要 |
PURPOSE:To attain the highly efficient drive and low power consumption of a focus actuator part by providing a power supply switching means setting the 1st voltage level into the 2nd voltage level higher than the 1st level while a detection signal is generatd from a detection means. CONSTITUTION:A flaw detection circuit 23, based on a tracking error signal and a signal obtained from an optical pickup 13, generates an L level detection signal when the abnormal quantity of a signal read by the optical pickup 13 due to a flaw on the disc 11 is within a prescribed value and generates an H level detection signal when the quantity is a prescribed value or over. Thus, in reproducing the disc 11 with less flaw, a power supply voltage V1 is fed to a BTL drive circuit 18 and the focus actuator is driven with the efficient state. Further, in the reproducing state of the disc 11 having many flaws on it, the power voltage V2 is fed to the circuit 18, the peak of a pulse width modulation signal is decreased and the focus servo gain is lowered. Thus, the focus servo is applied with the efficient state to reduce the power consumption. |
