| 摘要 |
PURPOSE:To prevent a noise component from being wrongly detected as the movement of a picture by a movement detecting circuit, by controlling the gain of a gain controlling amplifier by means of the movement detecting signal of video signals and input field intensity detecting signals. CONSTITUTION:Means 4-6 which detect the 1-field or 1-frame difference signals of video signals and a means 3 which subtracts signals obtained by passing the 1-field or 1-frame signals through a gain controlling amplifier (multiplier) 8 from the video signals are provided and the gain of the amplifier 8 is controlled by using signals SM detecting the movement of the video signals and signals SC detecting the intensity of an inputted electric field. Since the coefficient K of the multiplier 8 is controlled in accordance with both of the movement detecting signals and the intensity of the inputted electric field in such way, the coefficient K can be prevented from being wrongly detected as small one when noise components are abundant at the time of middle-weak input electric field.
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