Optical design of a micro DLP projection system based on LEDs and an innovative light pipe

Abstract

Micro projection systems not only can be applied in portable display technology, but can also be applied to adaptive automobile headlamps. Present DLP technology cannot collect and utilize the light which is reflected by the micromirrors of the DMD in the "OFF" state. Aiming at this defect, a design scheme of a micro DLP projection system based on LEDs and an innovative light pipe is presented. First, the related parameters of each part are calculated according to the nonimaging optics theory. Second, the projection lens is optimized using ZEMAX software. Finally, we build a model and simulate it in TracePro software. The simulation results show that: when all the micromirrors of the DMD are in the "ON" state, the light efficiency is 36.13%; when half of the micromirrors are in the "OFF" state, the light efficiency is 27.23%.Compared with having no light pipe, the light efficiency is increased by 5.33%.