PURPOSE: To eliminate a false pulse due to a failute of erasing which frequently occurs on a rewrite type optical disk by providing a gate means for the false data pulse due to the failure of erasing.
CONSTITUTION: A reproduced waveform (b) is inputted to a second gate generating circuit 8 and passes an integrator to obtain a variance slice level (c) and this level (c) is used to slice the voltage of the reproduced waveform, thereby obtaining a second gate signal (j). AND between a data pulse (i) including an error pulse F and the second gate signal (j) is operated to obtain a corrected data pulse (k) where the error pulse is eliminated. Thus, the false pulse is eliminated to accurately reproduce data even in the case of residual of erasing exists.
UCHIDA KOICHIRO
KATO HIROYUKI
