| 摘要 |
In a noise suppression circuit for a video signal, the input video signal is separated into its high and low frequency components by a separating circuit (3). The signal at an output (15) of a delay circuit (17) is combined with the separated low frequency signal in a combining circuit (11) whose output is applied to the input (19) of the delay circuit (17). The time delay of the delay circuit (17) is switched from field to field by means of a change-over switch (53) so that this time delay changes from field to field to a field period minus and a field period plus half a line period. The noise-suppressed low frequency output from the combining circuit (11) is added to the separated high frequency component in an adder circuit (25). In use such a noise suppression circuit produces substantially no travelling noise patterns on a television display.
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