Compact single-panel LCD projector with high uniformity

In this study, we introduce a single-panel LCD projector that employs a direct-lit LED array as its illumination system. Each LED in the array is coupled to a Fresnel lens to ensure light collimation. To create a uniform light distribution on the LCD panel, the LED array is arranged in a hexagonal pattern. To eliminate the hotspot effects caused by individual LED units, the optical distance between each unit and the LCD panel is extended to allow sufficient light mixing. Köhler illumination is adopted to generate adequate and homogeneous illumination on the screen. With these design enhancements, we managed to shrink the system by 29% of the traditional designs and increase uniformity to 90.1%.