PICTURE MIXING CIRCUIT

PURPOSE:To eliminate fog of contour and to prevent flicker by mixing a contour signal and a character signal at the contour of a colored character signal through soft keying and superimposing the contour correction signal onto the signal. CONSTITUTION:In mixing a profile signal YB to a background signal SA, a mix signal SM is obtained from an output terminal of a mixing circuit 10. A slice pulse (contour correction signal) YS is obtained from a slice circuit 22. The signals SM and YS are fed to an adder circuit 30, where they are mixed. Since the voltage VS of the slice circuit 22 forming the signal YS is coincident with the slice voltage VS in the amplifier 21, the contour correction signal YB is obtained at a time corresponding nearly to the midpoint of the soft keying period X. A synthesized video signal S0 is obtained from the adder circuit 30.