At 6mm thick, the stacked flat type light guide panel from DynaScan Technology (Taipei, Taiwan) is an assembly of simple flat light guides, without any curvature or wedge angle, allowing over 90% light output efficiency. Due to the flat lightguide structure and front space providing an adjustable long light-mixing area, the uniformity of output light can approach to ideal within one light-guide. Compared to conventional direct-lit RGB LED backlight, power consumption of stacked flat type RGB backlight is reduced by a factor of 40% by utilizing both local dimming and ultra high efficiency flat light guide panels.