Patent ID: 7366065

Claim:
A disk recording and reproducing method for an optical disk apparatus, in which a reproducing operation is performed under servo control of an actuator in a servo loop of continuous servo type, the actuator controlling an objective lens, a low-speed recording operation is performed under servo control of the actuator controlling the objective lens in a servo loop of sample-and-hold type and a high-speed recording operation is performed under servo control of the actuator controlling the objective lens in a servo loop of average servo type, the method comprising: a first step of applying a first disturbance signal to the servo loop of continuous servo type at the time of reproducing operation and observing a first learning servo signal of average type produced based on the first disturbance signal; a second step of applying a second disturbance signal equivalent to the first disturbance signal to the servo loop of sample-and-hold type at the time of low-speed recording operation and observing a second learning servo signal of average type produced based on the second disturbance signal; a third step of setting the gain of the servo loop of average servo type based on the result of comparison between the first learning servo signal and the second learning servo signal; and a fourth step of performing the high-speed recording operation under servo control of the servo loop of average servo type with the gain set by the third step.