Digital signal apparatus for correctly demodulating data despite a

Abstract

A digital signal regeneration apparatus measures regeneration output pulses produced by binary-coding an analog signal acquired by reading information from a recording medium to regenerate a digital signal recorded on the recording medium, comprising a pulse spacing extracting circuit for extracting a pulse spacing of a binary-coded regeneration output pulse, a pulse multiple detecting circuit for detecting a multiple indicating how many times a pulse spacing the pulse spacing extracting circuit extracts is larger than a reference cycle, a reference cycle calculating circuit for calculating a new reference cycle using the pulse spacings and multiples of a plurality of predetermined contiguous regeneration output pulses sent from the pulse spacing extracting circuit and pulse multiple detecting circuit, a clock generating circuit for generating a demodulating clock using the reference cycle the reference cycle calculating circuit calculates, a clock synchronizing circuit for synchronizing a demodulating clock the clock generating circuit generates in phase with regeneration output pulses in given durations, and synchronizing the demodulating clock in phase with a regeneration output pulse coming in a given initial range of data regeneration not by locking the demodulating clock in a given interval but by matching the demodulating clock and the regeneration output pulse coming in the given initial range, a demodulating circuit for demodulating a binary-coded regeneration output pulse train using the demodulating clock the clock generating circuit generates.