Patent ID: 7215606

Claim:
An optical disk device, comprising: an optical head which emits a laser beam to an optical disk and receives a reflection light by using an objective lens, thereby carrying out one of a recording process and a reproduction process; a position control portion which carries out position control of at least one of the optical head and the objective lens by a compensation gain based on a detection signal from the optical head; and a disturbance learning portion which adjusts the compensation gain of the position control portion, detects disturbance information of the optical disk by using the optical head, and stores the disturbance information as learning disturbance information; and a phase adjuster which adjusts a phase of the compensation gain according to a degree of reduction when the disturbance learning portion reduces the compensation gain of the position control portion; wherein the disturbance learning portion reduces the compensation gain in a stepwise manner in a range in which position control of at least one of the optical head of the control portion and the objective lens operates, and detects and stores disturbance information of the optical disk by using the optical head, wherein the disturbance learning portion has a detector for detecting rotation information based on a signal output from the optical head, and carries out learning of the disturbance information at a timing given by this rotation information, and wherein the disturbance learning portion also stores the disturbance information of the optical disk in an area corresponding to a predetermined rotation number of the disturbance information.