Comb filter for separating luminance signal and chrominance signal of a composite PAL colour signal

摘要

In a comb filter for separating Y and F in PAL, the signal separation achieved is to be improved and the averaging is to be kept minimum over a number of lines. The composite colour signal sampled at four times the colour subcarrier frequency (4fsc) and digitised is supplied to the series circuit of two line delay lines (4, 5), from the three taps (a, b, c) of which the chrominance signal (c) is obtained via two subtracting stages and one switch (8) and is subtracted for forming Y from the composite colour signal. Especially intended for improved PAL transmission systems such as, for example, S-VHS and HDTV. <IMAGE>