PURPOSE: To minimize a circuit scale, to execute a processing at high speed and to improve performance.
CONSTITUTION: A reading signal (a) with analog amplitude from a magnetic recording medium not shown in a figure is made into an absolute value by an absolute value conversion circuit 1, is made into a digital signal by an A/D converter 2 and, then, is supplied to a waveform equalizer 3. The waveform equalizer 3 executes a processing for permitting the value of sample data except sample data corresponding to amplitude (1) in the output absolute value signal (b) of the absolute value conversion circuit 1 to be small and '1' and '0' bits are judged by a data judging equipment 4 from an equalization output signal (d) processed in this way. Therefore, a process signal is previously adopted as a right value signal so that positive and negative code bits become useless for the digital signal obtained by the A/D converter 2. Then, the bit number of the digital signal is reduced and the equalizing processing in the waveform equalizer 3 and the judging processing in the data judging equipment 4 are easily executed.
TAKASHI TERUMI
YAMAKAWA HIDEYUKI
ISHIDA YOSHITERU
