Patent ID: 8223606
Filing Date: 2012-07-17
Classification: G11B

Abstract:
1. A defect-detecting circuit for detecting a defect area on a disc track, the defect-detecting circuit comprising: a first peak hold unit, for receiving a source signal and holding the peak level of the source signal, thereby outputting a first signal at a first drop rate; a first subtractor, for subtracting a first threshold value from the first signal, thereby generating a first slice signal; a second peak hold unit, for receiving the source signal and holding the peak level of the source signal, thereby outputting a second signal at a second drop rate; a second subtractor, for subtracting a second threshold value from the second signal, thereby generating a second slice signal; a multiplexer electrically connected to the first subtractor and the second subtractor, and having a first input end to receive the first slice signal, a second input end to receive the second slice signal, an output end and a select end; and a comparator, having a first end receiving the source signal and a second end coupled to the output end of the multiplexer, for comparing the source signal with either the first slice signal or the second slice signal, thereby generating a defect signal, wherein the first slice signal and the second slice signal are selectively outputted from the multiplexer according to the defect signal inputted into the select end of the multiplexer.