Application of field emission as backlight unit for LCDs

摘要

Liquid crystal displays (LCDs) have become main stream in the flat panel display industry [1]. Currently, most LCDs have a continuous white backlight and use red, green, and blue color filters forming three sub-pixels to make a pixel. With such a widely used approach, two-thirds of the light is absorbed in the color filters. See Fig. 1(a). Several approaches are proposed and some of them efficiently save the power consumption, like the local dimming technology [2] and the field sequential color displays [3]. Both of these technologies required the change of the backlight. The application of local dimming LCD requires a locally controllable backlight unit; Field sequential color LCD requires a temporally controllable backlight unit. The combination of these two technologies improves the light efficiency 3 times higher than normal and reduces the power consumption to less than one-third. So a kind of spatially and temporally controllable backlight unit is on demand for the future LCDs. Fig. 1(b) shows an example of such backlight unit based on LED matrix [3].