Patent ID: 7263040

Claim:
A read/write position controller of a pickup that reads from and/or writes to a recording medium while relatively moving a read/write position of the pickup and a read/write target position of the recording medium, comprising: an error signal generator for generating a position error signal indicating an error between the read/write position of the pickup and the read/write target position of the recording medium; an actuator for driving the pickup to change the read/write position of the pickup; a servo controller for performing nonlinear control and linear control of the read/write position of the pickup according to the position error signal to drive the actuator; a switching section for switching the servo controller from open mode to closed mode according to the position error signal; and an adjusting section for adjusting the gains of the nonlinear control and the linear control so that the nonlinear control component is larger than the linear control component at the time of switching of the servo controller from open mode to closed mode and the linear control component is larger than the nonlinear control component after the elapse of a predetermined time from the time of switching.