| 摘要 |
PURPOSE:To enable variable setting of the DC restoration ratio in the same manner if the original color signal is one reproduced from the reception TV signal or one otherwise by variably setting the DC restoration ratio against the original color signal. CONSTITUTION:Signals R, G, and B are lead to a luminance signal synthesizing matrix circuit 3 through amplitude adjusting circuit 11-13, and converted to a luminance signal Y. The signal Y is supplied to an average DC voltage detecting circuit 4, and its average DC voltage is detected. The detected voltage is weighted by a weighting circuit 5 by means of multiplication by a proper constant number, and then is made one input to a control-voltage adding circuit 6. The circuit 6 is supplied another input which is the luminance-adjustment control-voltage VB. The addition output obtained in the circuit 6 by adding the two inputs, is lead as an input to DC restoration/luminance adjusting circuits 21-23. In these circuits 21-23, the DC restoration and the luminance adjusting are performed. After being amplified by output circuit 71-73, the signal is supplied to the cathode of a picture tube 8.
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