| 摘要 |
PURPOSE:To correct a color difference signal in correspondence to the correction of a luminance signal with simple constitution and to make a color balance excellent by forming a gradation signal of the color difference signal with the aid of a gradation correction signal regarding the luminance signal. CONSTITUTION:A luminance signal Y1 is inputted to one side of a mixer amplifier 9 through a buffer amplifier 7 and a delay circuit 8 from an input terminal 1 of the luminance signal. An output of the amplifier 7 is added to a knee circuit 10, and a gradation change close to a black signal level is emphasized and added to the other side of the amplifier 9 through a subtractor circuit 11 and a gain control amplifier 10, the luminance signal having corrected gradation is outputted from an output terminal 4 of the luminance signal. Said luminance signal is supplied to gain control circuits 24 and 20 for gain-controlling each color difference signal from input terminals 2 and 3 of the color difference signal. The gradation correction signal of each color difference signal is formed with the aid of a gradation correction signal regarding the luminance signal Y1, and with simple constitution the color difference signal can be corrected in correspondence to the correction of the luminance signal.
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