| 摘要 |
PURPOSE:To correct a color transient by restricting upper and lower electric potential of a pulse-shaped signal obtained by differenciating and full-wave rectifying color difference components and by using correcting pulse made out of a signal restricted amplitude. CONSTITUTION:The color difference components are inputted to one input terminal of a differencial amplifier consisting of resistances 6 and 7, transistors 8 and 9 and an electric power source through a resistance 4 as it is. Differenciation of the color difference components is obtained as an output by inputting the color difference components integrated with a resistance 5 and a capacitor 11 to the other input terminal. Furthermore, the color difference components are full-wave rectified with transistors 12 and 13, and a pulse-shaped wave is obtained. When an electric potential of the A point drops lower than that of the B point to the extent sufficient for transistor 15 to turn on, the electric potential of the A point is fixed to the electric potential lower by the value equivalent to the electric potential difference of inter-base emitter of transistor 15 than the electric potential of the B point. On the other hand, the electric potential of the A point rises higher than that of the C point to the extent sufficient for transister 16 to turn on, the rise of the electric potential of the A point is restricted by the turning on of the transistor 16. Namely, the signal of the A point is restricted vertically by the transisters 15 and 16.
|
