Patent ID: 9245571
Filing Date: 2016-01-26
CPC Classification: G11B

Claim Text:
1. An optical disc device that reads information recorded in an optical disc medium, the optical disc device comprising: an objective lens configured to focus light on the optical disc medium; a spherical aberration correction mechanism configured to change an amount of spherical aberration of the objective lens according to a setting value of a predetermined parameter; an evaluation value measurement section configured to measure an evaluation value indicating accuracy of reading of information from the optical disc medium; and a control section configured to execute adjustment processing in which the control section carries out a plurality of times of measurement of the evaluation value by the evaluation value measurement section concurrently with changing the amount of spherical aberration of the objective lens by the spherical aberration correction mechanism and calculates an optimum setting value of the parameter based on a plurality of evaluation values obtained by the plurality of times of measurement; wherein the plurality of times of measurement of the evaluation value by the evaluation value measurement section is performed while an on-state of a collimator lens drive signal continues and while the collimator lens moves toward a constant direction; and wherein a tracking servo control signal of the optical disc device is turned off from the first of the plurality of times of measurement of the evaluation value through to the calculation of the optimum setting value of the parameter.