| 摘要 |
PURPOSE:To prevent the generation of color bleeding by constituting the titled comb line filter of three synthesizers, a delaying circuit and a limiter circuit, and setting appropriately a coefficient to be multiplied to a feedback quantity given from the delaying circuit to the first synthesizer, and an output provided from the limiter circuit to the third synthesizer. CONSTITUTION:An input signal is sent to the synthesizers 2, 7. The output of a 1H delaying circuit 3 is sent to the synthesizer 4, and simultaneously, sent to the synthesizer 2 through a coefficient circuit 8 having a feedback quantity K. The output signal of a limiter circuit 5 passes through a coefficient circuit 6, and it is synthesized with the input signal by the synthesizer 7 and outputted. In case when the vertical correlation of chrominance components is large, the output of the synthesizer 4 is not influenced at all by the limiter circuit 5. A frequency characteristic in this time is varied by the feedback quantity K, and for instance, in case of K=-0.8, an S/N is improved remarkably. Also, in this case, the color bleeding is inconspicuous entirely. In case when the vertical correlation of the chrominance components is very small, the output of the synthesizer 4 is limited by the limiter circuit 5, the input signal is outputted as it is to a terminal 9, and the color bleeding in the vertical direction is not generated. Said coefficient K is set to -0.5--0.8. Also, the limiter level of the circuit 5 is set to 10-30% of the maximum amplitude of the output of the synthesizer 4.
|
