| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem of unstable tracking control caused by a reduced AGC output because of the shifting of irradiation power from a proper value on an optical disk depending on recording conditions. SOLUTION: In parallel with the supplying of a signal from a bisected photodetector 19 through a differential amplifier 11 and an address signal processing circuit 30, the signal of a signal detection photodetector 8 is passed through a signal processing circuit 15 to be received by a drive control circuit 15, and output to a driving control circuit 14. The signal of the differential amplifier 11 is output through an ACG circuit 12 and a gain variable amplifier 13 to the driving control circuit 14. By inputting the output of the driving control circuit 14 to a driving circuit 20 for driving an optical beam 4, a light quantity proper for an optical disk 1 is controlled, and tracking control is stabilized. COPYRIGHT: (C)2004,JPO
|
