| 摘要 |
PURPOSE:To perform the switching of a reproducing channel correctly by providing a lacking signal correction circuit constantly generating a pulse signal of a repeating period 2nH synchronizing with a horizontal synchronizing signal of a demodulated video signal and a duty ratio of 50%. CONSTITUTION:When the video signal separated into two channels at every 1H is switched and recorded, a demodulated waveform is shown in A. A horizontal synchronizing signal separating circuit 1 separates a horizontal synchronizing signal and obtains the horizontal synchronizing signal B. According to the output B of the circuit 1, a switching circuit 2 generates the pulse signal C inverted at every 1H. Since the lacking signal correction circuit 3 is constituted so as to synchronize the pulse signal of the period 2H and the duty ratio of 50% with the output of the output of the circuit 2, the output of the circuit 3, produces the inversion of the pulse signal even at the time 52 as shown in D.
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