| 摘要 |
PURPOSE:To facilitate the measuring of the degree of jitter, by providing a means to obtain the umber of trailing edges of pulses generated for a time length centering around time after a specified time elapses from leading edges of pulses in a waveform to be measured and the number of trailing edges of pulses generated in a short space of time from said time. CONSTITUTION:A reproduction signal pulse train from a CD player 1 is applied to a falling detector 6 and a rising detector 7 via a shaping circuit 2, a switch 4 and a differentiation circuit 5. An output of the detector 6 is applied to one input terminals of AND circuits 11 and 12 while an output of the detector 7 is applied on the other terminals of the circuits 11 and 12 via first and second time generators 8 and 9. Outputs of the circuits 11 and 12 are applied to a CPU15 via counters 13 and 14 and the results of measuring jitter are obtained at an output terminal 16 of the CPU15. A control output 17 from the CPU15 is applied to the counters 13 and 14 while a control output 18 to the switch 4. Thus, the degree of jitter can be measured easily concerning a desired reference pulse.
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