Recording disk data playback apparatus

Claim 1

In a recording disk playback apparatus capable of playback fo a recording disk having recorded thereon a video signal which may be accompanied by an audio signal which has been converted into a frequency modulated signal, and a digital signal superimposed on said frequency modulated signal, the improvement comprising: pick-up means for producing a playback digital signal from said recording disk; demodulator means for demodulating said playback digital signal; memory means; write-in means for writing said demodulated output from said demodulator means into said memory means in synchronization with a playback clock signal which is contained in said playback digital signal; servo loop means for implementing position control of a read-out point across a surface of said recording disk along a direction which is tangential to a recording track on a recording disk to be played back; and a read-out clock signal generating circuit for generating a read-out clock signal in synchronism with said playback clock signal, said read-out clock signal being utilized to read out data stored in said memory, said read-out clock signal generating circuit comprising a phase lock loop circuit for controlling the frequency of said read-out clock signal, said phase-lock loop circuit including a loop filter for bandwidth limitation connected therein, with the cut-off frequency of said loop filter being selected to be lower than the maximum frequency of the bandwidth of said servo loop.