Patent ID: 7102978

Claim:
An optical disk apparatus for recording data to and/or playing back data recorded on an optical disk in a format of a plurality of formats by directing a laser beam to the optical disk, comprising: playback signal generator means for receiving returning light of the laser beam, and for generating a playback signal which varies in signal level in accordance with the reflectance at a location of the optical disk where the laser beam is directed and based on the format of the optical disk; a system controller for determining the format of the optical disk from the plurality of formats and operating an optical pickup associated with the playback signal generator means in a first mode to seek management information recorded on a burst cutting area of the optical disk and in a second mode to seek management information recorded on a narrow burst cutting area of the optical disk, depending on the determined format of the optical disk; envelope detector means for detecting an envelope signal of the playback signal; offset means for generating a binarization threshold signal by offsetting the envelope signal by an offset voltage, the binarization threshold signal varies based on the format of the optical disk; bandwidth limiter means for limiting a high-frequency signal level variation of the playback signal; binarizing means for binarizing an output signal of the bandwidth limiter means according to the binarization threshold signal as a reference to generate a binary signal; and decoder means for decoding the binary signal to demodulate management information recorded in a bar-code form on the optical disk.