| 摘要 |
PURPOSE:To enhance the picture quality, by setting the dynamic range of a green cathode driving circuit larger than those of the cathode driving circuits of other two colors for a color picture tube having an ordinary face plate. CONSTITUTION:The color difference signals of R-Y, G-Y and B-Y which are demodulated at a chroma circuit are connected to the bases of transistors QR, QG and QB respectively. The luminance signal demodulated by a video circuit is applied to an emitter via variable resistances R5R and R5B for controlling white balance with QR and QB respectively, and applied to the emitter via a resistance R4G for the QG. An end of an emitter resistance R3G of the QG is connected to the negative voltage. Thus the dynamic range of a green cathode driving circuit QG can be set larger than those of the cathode driving circuits QR and QB of other two colors to enhance the picture quality. |
