Optical information recording or reproducing apparatus.

摘要

In an optical information recording or reproducing apparatus, an asymmetry detection circuit (16) detects asymmetry values from digital RF signals reproduced from the reference area of an optical disk (3) according to a timing signal generated by a timing signal generator (13). The digital RF signals are demodulated by the viterbi algorithm by a viterbi detection circuit (17) on the basis of asymmetry values detected by an asymmetry detection circuit (16). <IMAGE>