Patent ID: 7551529

Claim:
An optical disc apparatus for performing information recording or reproduction on or from an optical disc, the optical disc apparatus comprising: an optical pickup having an optical detector which receives a reflecting beam, by four divided detection regions, from the optical disc which is irradiated with a laser beam; a focus error signal generation circuit which generates a focus error signal based on detection signals from the four divided detection regions; and a servo control part which performs tracking servo and focus servo of the optical pickup on the optical disc, wherein the focus error signal generation circuit comprises focus servo drive amplifiers that amplify the detection signals individually, and wherein the servo control part measures an amplitude level of the focus error signal for performing focus search, sets gains of the focus servo drive amplifiers as initial values based on a result of the measurement so as to bring the amplitude level of the focus error signal to a target value, and measures amplitude levels of the respective detection signals and controls the gains of the focus servo drive amplifies individually so that crosstalk can be cancelled based on the measured amplitude levels of the respective detection signals.