Disk-reproduced signal equalizer

Abstract

A disk-reproduced signal equalizer includes pairs of delay circuits, selection circuits, and a differential amplifier circuit. The delay circuits are arranged in correspondence with a plurality of divided track areas on a disk and respectively having delay characteristics set to provide optimal equalization characteristics, for each track area, with respect to a reproduced signal input from a disk recording/reproducing apparatus of a constant wave length-constant angular velocity scheme of performing a recording/reproducing operation at a substantially constant recording wave length by changing a clock frequency in accordance with a track position while keeping a rotational speed of the disk constant. Each delay circuit has a plurality of output taps. The selection circuits select one of the pairs of delay circuit on the basis of information supplied from the disk recording/reproducing apparatus and indicating a track position. The differential amplifier circuit receives outputs from the output taps of one pair of delay circuit selected from the plurality of pairs of delay circuit, and performs predetermined equalization processing.