| 摘要 |
PURPOSE: To suppress amplitude fluctuation in a vertical direction, to reduce the density modulation of a scanning line by a high voltage and to eliminate horizontal stripes by detecting the white signal period of video signals and performing input to a vertical amplitude compensation circuit. CONSTITUTION: The amplitude detection part 9 of a video signal amplitude detection circuit 5 outputs detection output only in the white signal period of input video signals, an output delay part 10 delays the detection output of the circuit 9 for the fixed period of time and the delayed detection output is added to the changeover switch 7 of the vertical amplitude compensation circuit 6. A feedback resistance value at normal time becomes the parallel synthetic resistance value A of a feedback resistor 3 and the feedback resistor 8 for vertical amplitude compensation. Then, the switch 7 is opened only in the period when the detection output is added and the feedback resistance value becomes the value B of only the feedback resistor 3. Thus, by setting the ratio of the A and the B so as to cancel the vertical amplitude fluctuation by high voltage fluctuation of the white signal period, the horizontal stripes are eliminated. |
