Abstract: To improve the track pull-in performance in the servo control of an optical disk device, track pull-in is performed by driving the objective lens by an actuator, outputting an electrical signal according to the amount of reflected light from the optical disk, generating a focus error signal and a tracking error signal from the output electrical signal, outputting a focus control signal based on the focus error signal to drive the actuator in the rotation axis direction, outputting a tacking control signal based on the tracking error signal to drive the actuator in the radial direction of the optical disk, controlling the speed of the actuator so that the cycle of the tracking error signal is kept substantially constant, moving the objective lens in the radial direction before the start of the speed control, and supplying the tracking control signal to the actuator after the start of the speed control.

Abstract: A method is provided to start calibrating TE signals in an optical disk drive by checking the change of focus balance, outputting a first TE signal by adjust to a predetermined gain, measuring the peak and trough of the first TE signal, changing the laser power to output a second TE signal on condition of the same focus balance and predetermined, measuring the peak and trough of the second TE signal, calculating and adjusting to a calibrated gain to quickly calibrate the TE signal.

Abstract: In an optical disc device, a way of canceling a lens shift due to an electric offset of an output of a tracking actuator driving circuit is desired. A tracking servo control circuit contains a first operation mode for setting an output current of the tracking actuator driving circuit to generally zero and a second operation mode for supplying a predetermined potential to the input. An average potential of a push-pull signal detected in the first operation mode is acquired. An object lens is moved by a predetermined amount in both radial directions by changing a potential supplied in the second mode to acquire correlative relationship between average potential of a push-pull signal relative to a lens movement amount and the supplied potential. An offset amount is acquired from the potential and the correlative relationship to cancel the offset.

Abstract: An optical disc apparatus of the present application has a lens position signal generator for generating a lens position signal representative of a position of an objective lens in a disc radial direction, an amplitude corrector for correcting an amplitude of a tracking error signal, and a tracking controller for generating an actuator drive signal for controlling an actuator, from an output of the amplitude corrector, wherein the amplitude corrector corrects an amplitude of the tracking error signal in accordance with the lens position signal to make approximately constant a tracking error detection sensitivity relative to a displacement between an optical spot and a track.