| 摘要 |
PURPOSE:To eliminate the variation of amplitude with every field of the output signal, by obtaining the sample-and-hold state of the time-division type and then giving a control to secure a constant amplitude of the burst signal of each field. CONSTITUTION:The output terminal of the automatic color signal control amplifier 22 which is capable of control of the gain and receives the input of the color signals of different amplitudes with every field of the color TV signal is connected to the 1st input terminal. In addition, the analog multiplier 24 which receives the supply of the color signal subcarrier 241 and the burst gate pulse 25 at the 2nd and 3rd input terminals, the 1st and 2nd gate circuits 27 and 28, the 1st and 2nd low pass filters 29 and 30 plus the change-over switch circuit 31 are provided respectively. Then the signal of either one side input terminal is led selectively to the output terminal by the field pulse 34, and this output is applied to the gain control terminal of the amplifier 22. |
