Optical Disc Apparatus and Method for Discriminating Optical Disc

摘要

This invention improves the accuracy of wobble signal detection for disc discrimination and reduces discrimination errors due to noise. In an optical disc apparatus, a wobble signal generator creates a wobble signal from an electrical signal which has been obtained from conversion by a pickup. A bandpass filter (BPF) is set to change its central frequency to a wobble frequency f0 and to fn different from the wobble frequency, and the filter extracts the respective frequency components from the wobble signal. An amplitude-measuring section measures amplitude levels A0 and An of the extracted multiple signals. A disc discriminator compares the multiple amplitude levels and if the amplitude A0 is greater than the amplitude An by at least a threshold level Ath, judges that a wobble is present.