Abstract: This article proposes a creative brightness average method to improve the traditional dithering algorithm for super twisted nematic-liquid crystal display (STN-LCD). This method restrains the flicker and crosstalk phenomena by avoiding the simultaneous turning on or turning off between adjacent pixels in the same frame. It costs little hardware to realize the brightness average circuit in the liquid crystal display (LCD) controller, without increasing the complexity of STN-LCD driver circuit. The experimental results show that when the frame frequency is 60 Hz, the monochrome image adds up to 64 gray levels, while the multicolor image adds up to 643 = 262 144 colors. Meanwhile, the power consumption of the prototype is only 3 317 mW. In short, the brightness average circuit can restrain the phenomena of flicker in high efficiency, and can remarkedly improve the gray and multicolor effect for STN-LCD without increasing the frame frequency, which leads to an apparent decrease in the power consumption.

Key words: dithering algorithm;STN;LCD;flicker