Luminance/chrominance signal separation circuit having filter circuit using pulse patterns suppressing circuit

摘要

A color picture signal processing circuit, a filter circuit and a luminance/carrier chrominance signal separation circuit implemented by employing the filter circuit. The circuit processing signal includes an adaptive-type (C) comb line filter through which the luminance signal is caused to pass. The output of the filter undergoes amplitude limitation in a limiter circuit, the output of which is subtracted from the original luminance signal. The carrier chrominance signal is added to the luminance signal to obtain a composite picture signal. The filter circuit is comprised of a pulse pattern suppressing circuit including a decision circuit for deciding which of positive and negative patterns the three adjacent data form constitute, a positive pulse pattern suppressing circuit, a negative pulse pattern suppressing circuit and a circuit selecting for either one of the output signal of the positive and negative pulse pattern suppressing circuits in accordance with the result of decision made by the decision circuit.