| 摘要 |
PURPOSE:To reduce the scoop noise varying in accordance with the optical path length of the returned light ranging over the total optical path length. CONSTITUTION:The returned light from an optical disk 8 is detected by a photodetector 9 and the level of a high frequency component incorporated in the detection signal being detected by the photodetector 9 is detected by a high frequency level detecting circuit 13. The high frequency drive circuit 14 controls the high frequency output circuit 15 in accordance with the level of the high frequency component detected by the high frequency level detection circuit 13 and the laser diode 1 is driven by the high frequency signal outputted from the high frequency output circuit 15. |
