Patent ID: 6396787
Filing Date: 2002-05-28
Classification: G11B

Abstract:
An apparatus for generating an eight-to-fourteen modulation (EFM) signal in an optical disk reproducing system, the EFM signal generated from a radio frequency (RF) signal reproduced from an optical disk, comprising:a data slicing unit for selecting, in response to a selection signal, one of a first slice reference level and a second slice reference level to be a third slice reference level, said first slice reference level being generated by correcting asymmetry of the RF signal and said second slice reference signal being generated using peak and bottom envelopes of the RF signal and the first slice reference level, said data slicing unit slicing the RF signal based on the third slice reference level to generate the EFM signal; a selection signal generating unit for generating the selection signal in response to a number of occurrences of at least one of error correction flags and EFM flags; and an EFM flag generating unit for generating the EFM flags in accordance with bit pattern which is not used in demodulating the EFM signal, wherein error correction flags are generated in accordance with an amount of error which is present in the demodulated EFM signal.