Patent attributes
Before initiation of tracking control, an optical disk device performs an offset amount obtaining operation, in which a difference between a middle value of the amplitude of a tracking error signal and a predetermined reference value is obtained as an offset amount. After the initiation of the tracking control, the optical disk device initiates an attenuation operation, in which an offset amount attenuation section attenuates the offset amount obtained by the offset amount obtaining operation to obtain an attenuated offset amount, while initiating, with an initial value being 0, an estimation operation, in which an observer estimates the offset amount according to a tracking driving signal to obtain an estimated offset amount. The optical disk device corrects the tracking error signal by using the attenuated offset amount obtained by the attenuation operation and the estimated offset amount obtained by the estimation operation.
