| 摘要 |
PURPOSE:To increase a S/N ratio visually, by reducing both the frequency property and the amplitude at an area where the S/N ratio is lowered as well as the noise area in a reproduced video signal. CONSTITUTION:The color signal in the output of the reproduction amplifier 2 is applied to the mixer 6 via the color signal process 5. The luminance signal is supplied to the mixer 6 via the limiter 3, demodulator circuit 4 and noise reduction circuit 7 each. Both the luminance signal passed through the circuit 4 and the signal that obtained from the signal supplied from the amplifier 2 and through the envelope wave detection circuit 8, pulse generator circuit 9 and H blanking insertion circuit 10 are supplied to the circuit 7. The circuit 7 applies the output that is reduced with its frequency property and amplitude at the noise area by the pulse supplied from the H blanking circuit 9 to suppress the noise area to the mixer 6. As a result, the noise is eliminated visually to obtain an easy-to-see reproduced screen. |
