Patent ID: 7315499

Claim:
An optical disk apparatus, comprising: a tilt detection unit detecting a tilt value of an optical disk medium with respect to an optical system, the optical system comprising a sub-chassis and a main chassis; a tilt compensation unit compensating for the tilt of the optical disk medium by pressing an end portion of the sub-chassis against a cam that changes height, thereby adjusting a relative angle between the optical system and the optical disk medium according to the tilt value detected by the tilt detection unit; and a tilt detection error estimation unit estimating tilt detection error of the tilt detection unit with respect to a radial position of the optical disk medium at which information is recorded/reproduced by the optical system by referring to tilt values that are previously detected at a plurality of radial positions of the optical disk medium by the tilt detection unit, the tilt detection error being the difference between a tilt sensor radius and an objective lens radius, wherein the tilt compensation unit has a correction unit that corrects the tilt value according to the tilt detection error estimated by the tilt detection error estimation unit, and the tilt compensation unit compensates for the tilt of the optical disk medium according to the tilt value corrected by the correction unit.