| 摘要 |
PURPOSE:To suppress color noise on a dark picture plane and to improve color staining on a bright picture plane, by providing an integration means which integrates a luminance signal, providing an amplifier which adjusts brightness corresponding to the output level of the integration means, and applying the output of the amplifier on a control volume. CONSTITUTION:A video signal (b) is impressed on the base of a transistor 3. As for a relation between the video signal (b) and the voltage of a color saturation volume, an integrated voltage is large in a dark signal (b1), and a voltage at a point C applied on the color saturation volume is inversely amplified at a transistor 8, and is lowered to a level as (c1), then, color saturation is suppressed. Also, in a bright signal (b2), the voltage at the point (c) is raised to the level as (c2), then, the color saturation is also increased. Thus, it is possible to change the color saturation corresponding to the change of the level of the video signal, to suppress the color noise on the dark picture plane, on the other hand, to improve the color staining on the bright picture plane.
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