| 摘要 |
PURPOSE: A fault detecting apparatus of an optical disk replaying system accurately detects faults existed in a RF signal by using an EFM(eight to fourteen modulation) signal generated in a data slice circuit. CONSTITUTION: A data slicer circuit(61) receives a RF signal generated from a pick-up unit, and generates an EFM signal by slicing it into a predetermined slice level. A fault detecting unit(63) detects a fault section according to a run length of the EFM signal outputted from the data slicer circuit, and generate a fault detecting signal(SDEP) muting a tracking loop and a focus loop so that a tracking error signal and a focus error signal are inputted by the tacking loop and the focus loop during the detected fault section. The data slicer circuit comprises a slice comparator(41), a plurality of invertor(43a,43b,43c), a first switch(45), a lowpass filter(47), a buffer(49), an amplifier(51), a second switch(53), a capacitor(C1), and a plurality of resistor(R1,R2).
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