Noise eliminating method

Abstract

Abstract PURPOSE:To eliminate the noise component superposed on the input signal and covering over a wide-range frequency, by extracting only the amplitude-type noise componet out of the input signal which receives an envelope curve detection and then using the difference between the noise component and the detection output of the envelope curve for the control signal of the amplitude limiting circuit. CONSTITUTION:An envelope curve detection is given to the amplitude modulated wave signal (a) such as the reproduced chromaticity signal of the VTR in the chromaticity signal low-range conversion recording system and by the wave detecting circuit DT. And only the amplitude-type noise component is extracted out of the output (b) of the envelope curve detection through the noise detecting circuit ND and then added to the adder AD of the resistance division or other types with the output (b) in the opposite phase to each other. the difference (d) between the noise component and the output (b) is used for the control signal of the amplitude limiting circuit LM. Here the addition at the adder AD is carried out with the amplitude of the noise component increased slightly, and the noise component of the opposite phase remains a little to the control signal (d). Then an amplitude limiting is given to the signal (a) by the signal (d) to eliminate completely the noise component of the signal (a).

Inventors

• 👤 Motoaki Kawasaki

Bibliographic Details