Power management of direct-view LED backlight for liquid crystal display

In this paper, we present a study of management of power in function of luminous efficacy of white LED as well as the efficiency enhancement of the direct-view backlight with photon recycling. A cavity efficiency as high as 90.7% is demonstrated for a direct-view backlight with photon recycling. In the future, with a 90% backlight cavity, luminous efficacy of 200lm/W for white LEDs, and a transmission efficiency of 10% for the liquid crystal panel, the required power of LEDs could be only 16W. Up to 85% energy saving could be achieved in comparison to the power of the current liquid crystal display. ► A design for a high-efficiency backlight with direct-view structure based on photon recycling. ► Optical efficiency of the backlight as high as 90.7% is demonstrated. ► When the luminous efficacy of white LED reaches 200lm/W, the power of LEDs is 16W for the backlight. ► 85% in energy saving can be achieved for LED backlight.