| 摘要 |
PURPOSE:To keep the amplitude level of a reproduced luminance signal constant, by controlling a demodulation sensitivity of an FM demodulator with an AGC signal detecting a reproduced video signal from the FM demodulator of a video signal recorder and reproducer. CONSTITUTION:When a recording and reproducing switching device 12 is selected to the recording side R, a recording luminance signal S'1 outputted from an AGC amplifier 3 is inputted to an AGC detector 4', an AGC signal is obtained at the detector 4' to control the amplifier 3. In selecting the switch 12 to the reproducing position P, a reproducing luminance signal S'3 outputted from a nonlinear deemphasis circuit 8 is inputted to the detector 4'. The amplitude of the signal S'3 is detected at the detector 4' to obtain the AGC signal, which controls the demodulation sensitivity of an FM demodulator 7'. Thus, the amplitude level of a reproduced luminance signal S'''3 outputted from the demodulator 7' is kept constant and reproducing video signal S4 is outputted via a noize canceller circuit 9, a mixer 10 for a color signal C and a luminance signal Y, and a video signal output device 11. |
