| 摘要 |
In order to reproduce an image signal from a frequency modulated wave which is obtained by frequency modulating a carrier with the image signal and picked-up from a magnetic tape by means of a magnetic head, the picked-up frequency modulated wave is supplied to a high pass filter for deriving a frequency modulated fundamental wave which is then supplied to a first limiter circuit to derive a first rectangular wave in response to zero crossings of the fundamental wave. Positive and negative pulse trains are generated by positive and negative pulse generators, respectively in response to front and rear edges, respectively of the first rectangular wave and are combined with each other in a first mixer to produce a combined pulse train. Then, the combined pulse train is superimposed in a second mixer upon the reproduced frequency modulated wave to produce a frequency modulated wave having the combined pulse train superimposed thereon, which is then supplied to a second limiter circuit to produce a second rectangular wave in response to zero crossings of the superimposed frequency modulated wave. The second rectangular wave thus produced is supplied to a detecting circuit and is demodulated to reproduce the image signal.
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