Optical Engine Design for a Compact, High-Luminance DLP Projector Using Four-Channel LEDs and a Total Internal Reflection Prism

How to obtain higher brightness with a small volume projection engine for 4K resolution digital light processing (DLP) is of great significance. In this paper, we first use the fourth channel serving as blue pump leading 52% gain green brightness. Secondly, new inline total internal reflection prism glued spherical mirror constructed notably reduce length relay illumination system by more than 10 mm, resulting in compact optical 210 × 140 36 mm3. Thirdly, lens optimized modulation transfer function 0.6 at 93 lines distance 2125 mm distortion lower 1%. As result, efficiencies RGB lights are 60%, and luminance uniformity on screen reach 1412 lm 94.5% measured prototype. Our proposed significantly helpful designing high-luminance DLP projection.