Method and device for protecting a slicer in reading signals on a defect disc

A device for protecting a slicer in reading signals on a defect optical disc from disturbance and instability, said device comprising:

• a defect detection unit, receiving a plurality of defect detection signals for setting a plurality of defect flag signals, wherein said plurality of defect detection signals at least include an envelope signal of a RF signal and bit modulation signals;
• said slicer, receiving and digitalizing said RF signal comprising:
• a high pass filter, filtering said RF signal to generate a high-pass-filtered RF signal;
• a comparator electrically connected to said high pass filter, comparing said high-pass-filtered RF signal from said high pass filter with a referred DC level to generate a digitalized RF signal;
• a charge-pump unit electrically connected to said comparator, comprising a plurality of current sources to compensate said digitalized RF signal from said comparator;
• and
• a low pass filter electrically connected to said charge-pump unit and said comparator, filtering said digitalized RF signal from said charge-pump unit and generates a slice level to feedback to said comparator as said referred DC level;
• and
• a logic combination unit, performing logic operation on said defect flag signals in order to detect a specified defect and to trigger defect protection for said slicer.