Patent ID: RE39952

Claim:
An optical disk apparatus for recording or reproduction on an optical disk including a track in which a recording region is wobble-processed, comprising: optical means for reading information from the optical disk or recording information in the optical disk; signal generation means for generating a tracking error signal indicating a scanning state of the optical means on the track included in the optical disk by the optical means; extraction means for extracting a wobble signal from the tracking error signal; amplitude detection means for detecting a wobble envelope voltage representing an amplitude of the wobble signal based on the wobble signal extracted by the extraction means; a bias generation circuit for outputting an average value of the wobble envelope voltage as a bias voltage; an arithmetic unit for calculating a positive square root of the wobble envelope voltage with respect to the bias voltage assumed as being “1”, and outputting a reciprocal of the calculated positive square root as a calculation result; and recording power control means for controlling recording power when the optical means records the information in the optical disk, based on the calculation result.