| 摘要 |
<p>An arrangement for the elimination of spurious chrominance component in the main luminance output signal from a chrominanceluminance separator of the comb filter type in an NTSC television receiver. The full band luminance signal from the comb filter is applied as one input to a switching circuit and the luminance component is also filtered by a low pass filter at least substantially eliminating the frequency band corresponding to the chrominance frequency channel in the whole signal and applied as a second input to the switching circuit. The switching circuit is arranged to normally transmit the full band luminance component and to be switched to couple the filtered luminance signal only upon occurrence of spurious chrominance components in the luminance signal. The switching circuit is actuated by a control signal derived by comparing the top and bottom line signals in the comb filter and producing a gating signal for the switching circuit when there is a difference in said frequency band in the top and bottom lines.</p> |
