| 摘要 |
PURPOSE:To attain ease of circuit integration by detecting noise component of a color TV signal and controlling each AGC circuit of video and sound system so as to realize the common use of a noise cancellor circuit. CONSTITUTION:A color TV composite video signal VS from a detector 12 is amplified 13 in a video signal processing system A, and its output signal VS' is applied to a buffer amplifier 14 and the noise cancellor circuit 15. The circuit 15 detects the noise component in the signal VS', its detected output expands the operating time of an AGC detecting circuit 16, the AGC output controls the gain of video image IFA11a-11c and the AGC output controls the gain of the RFA2 via an RF AGC circuit 17. Further, an output Sd of the detector 22 is applied to an amplifier 23 and an AGC detecting circuit 24 in the sound signal processing system B. Then, the output of the circuit 15 is given also to the circuit 24, and the AGC output controls the gain of the sound IFA21a-21c. |
