| 摘要 |
PURPOSE:To remove noises caused by a delay circuit by means of the subsequent FM demodulation and de-emphasis and to prevent drop in S/N by converting a field signal subjected to FM modulation into a frame signal. CONSTITUTION:An FM luminance signal YFM is branched into a signal inputted to a field/frame converting switch 18 as it is and a signal inputted to the other contact of the switch 18 through a 0.5H delay line 24. An FM luminance signal 26 converted into the frame signal through selection at every 1V of the switch 18 is demodulated by an FM demodulator 14, and becomes the luminance signal Y of a base band through a de-emphasis circuit 15. Thus the drop in S/N and flicker, both of which are caused by the delay line, can be prevented. The drop in the S/N and flicker of an FM line sequential color scan signal CFM, which are caused by the delay line, can be also prevented through the selection of a switch 30.
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