| 摘要 |
PURPOSE:To achieve signal reproduction with high fidelity, by setting a discrimination level according to the state of waveform. CONSTITUTION:A signal producing waveform distortion through the reception of effect of emphasis processing is in DC reproduction at an amplifier 11 and a clamp circuit 12. The output of the amplifier 11 is picked up as a signal pickup period set signal via a resonance circuit 13 in which the resonance point is set equal to the transmission frequency of a digital data in artificial television signal, full wave rectifying circuit 14, filter 15, and wave shape circuit 16, and given to a gate circuit 17 as a gate open signal. Thus, the data component in which ''0'' and ''1'' levels are alternately and consecutively repeated among the digital data in DC reproduction is selectively picked up at a clamp circuit 12 and applied to a maxumum value detecting circuit 18a and a minimum value detection circuit 18b. Both outputs are applied to a voltage divider 19 and a value determined through a specified voltage dividing ratio is given as a comparison reference level of a comparator 20. |
