Patent ID: 7643392
Filing Date: 2010-01-05
Classification: G11B

Abstract:
1. A tilt control method in an optical disk device for irradiating a laser beam onto a layer of an optical disk having a plurality of recording/reproducing layers for recording information or reproducing information, said optical disk device comprising an objective lens to focus said laser beam onto an information recording surface of said optical disk, a tilt actuator for tilting said objective lens, and a tilt controller which controls said tilt actuator, said method comprising: correcting a tilt value as an inclination of said optical disk relative to an optical axis of said laser beam, wherein different tilt values are set within a predetermined range at a predetermined radius position of a certain recording/reproducing layer so that a corrected tilt correction value is obtained according to a calculation value of a predetermined signal obtained from a reflected light from said certain recording/reproducing layer in each of the tilt values, wherein the corrected tilt correction value obtained from said certain recording/reproducing layer is applied to the other recording/reproducing layers other than said certain recording/reproducing, as well as being applied to said certain recording/reproducing layer.