JPS6425611A - Feedback type comb line filter - Google Patents

Abstract

PURPOSE:To reduce the deterioration in the frequency characteristic caused when the delay time of a delay circuit is deviated by subtracting an output signal of a delay circuit retarding the signal inputted via a 1st subtraction circuit and an output signal of the attenuation circuit so as to form an output signal. CONSTITUTION:A reproduced chrominance signal at an input terminal 1 is retarded by a 1st delay circuit 3 via a subtraction circuit 2 and added to an output signal of the subtraction circuit 2 at an adder circuit 4. The other signal is given to a 2nd delay circuit 5 for delay time correction. The output signal of the adder circuit 4 is fed to a limiter circuit 6. The output signal of the limiter circuit 6 is subtracted from the reproduced chroma signal at the input terminal at the subtraction circuit 2 through a coefficient circuit 7 and fed back to the 1st delay circuit 3. The output signal of the limiter circuit 6 is subtracted by a subtraction circuit 8 on the other hand and subtracted from the output signal of the 2nd delay circuit 5 by a subtraction circuit 9 and the result is outputted to an output terminal 10.