A 0.9' high resolution reflective microdisplay using ferroelectric liquid crystal on Si backplane has been developed. This device has 2.3 million pixels (UXGA/HDTV) with 16:10 aspect ratio. The highest resolution of 10 micrometers pixel pitch with 86% fill factor was achieved by the newly- designed pixel driver circuit. This circuit consisted of 5 transistors and 3 capacitors fabricated with only NMOS using conventional 0.35 micrometers CMOS process and the architecture with two memories per each pixel realized to write the next data into the pixel memory while the image was displayed. This enabled all the pixel data to be rewritten simultaneously with high refresh rate of 6.5 kHz, giving higher efficiency of light utilization than conventional scanning technique which rewrite the data at a line. The high refresh rate made color break-up invisible even in moving picture. In this system a new modulation technique using LED light source to generate grayscale was devised. The combined technique of pulse width modulation and light source modulation gave full color image using sequential color with high grayscale. This microdisplay is promising for projection displays and virtual image displays.