| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical disk drive unit, in which the actuator control of an optical pickup corresponding to a sum signal and a servo signal at the high speed recording operation to the optical disk in need of a high power is stably attained. SOLUTION: Amplitude levels of a sum signal SUM and servo signals TE, FE before gains are adjusted by an AGC circuit 25, are attenuated by attenuating means 20, attenuation factors of which are changed in accordance with the change of the amount of a light reflected from the optical disk at the recording time. Thus, since the amplitude levels of the sum signal SUM and the servo signals TE, FE for controlling an actuator of the optical pickup can be set in the input voltage range of the AGC circuit 25 by the attenuating means 20 even when the amount of the light reflected from the optical disk is increased in accordance with the increase of the recording speed, the gain adjustment in the AGC circuit 25 is surely executed, then the actuator control of the optical pickup corresponded to fetch signals at the high speed recording operation to the optical disk in need of the high power is stably attained.
|
