Data recording/reproducing apparatus using a recording disk.

摘要

An equalizer apparatus is to be applied to a disk recording medium of DBF, for which there is used a sampling clock reproduced from the clock pit recorded on a disk recording medium. A fixed equalizer block comprising an analog to digital converter, a memory and a two-dimension equalizer suppresses the wave interference from the adjacent tracks and can reduce the error rate of the reproduced data by cross-talk even in case of narrowing of the track pitch. Further, by adding to the equalizer a sign detector, an FIR low-pass filter and a coefficient control circuit to make it a blind equalizer block, the interference fluctuation attributed to linear recording density, recording power irregularity, light spot, tracking error, etc. can be automatically compensated to suppress such fluctuation. Further, By the construction of the blind equalizer block, the errors of clock timing and its fluctuation can be automatically compensated with good efficiency.