DEFECT COMPENSATION CIRCUIT OF OPTICAL DISK DISPLAYER

摘要

PURPOSE: A defect correction circuit is provided to eliminate a defect by sampling the same defect signals as defect signals of tracking error signals and inversely adding the defect signals. CONSTITUTION: A photodetector(110) consists of a main beam(111) and sub beams(112,113) for detecting tracking signals. An E amplifier(130) amplifies E signals of the sub beam(112) inversely while an F amplifier(120) processes F signals of the other sub beam. A differential amplifier(140) detects defect signals of the tracking error through comparison between the E and F amplifier signals. A filter(170) detects RF(Radio Frequency) signals of the main beam and eliminates noise. An envelope detector(180) samples an envelope from the RF signals. A first condenser(C1) eliminates DC elements from the defect signals of the envelope detector. A second amplifier(190) inverts the defect signals. A third or fourth resistance(R3,R4) eliminates the defect signals by adding the inverted signals of the second amplifier and the defect signals of the differential amplifier. A first amplifier(160) outputs the defect-eliminated signals. Thereby, the defect signals are eliminated from the tracking error signals.