Liquid Crystal Displays

Three types of liquid crystal displays (LCDs) have been developed: transmissive, reflective, and transflective. This chapter focuses on the thin film transistor-addressed wide-viewing angle transmissive LCDs which form the mainstream of LCD production and development. It introduces the twisted nematic, in-plane switching, and fringe field switching displays, as well as the multi-domain vertical alignment device mode. Although the LC material only occupies a thin layer in a display device, it makes crucial contributions to the device performance. The chapter addresses phase compensation methods for achieving wide viewing angle in LCDs. Contrast ratio is a key display metric affecting the image quality. Organic light-emitting diodes (OLEDs) exhibit a much higher contrast ratio than LCD. In the presence of surrounding light, the ambient contrast ratio (ACR) rather than the dark room contrast ratio is more representative. ACR has been widely used to evaluate the sunlight readability of LCDs and OLED displays.