Design And Simulation Of DLP Projection Lighting System Based On LED Light Source

Recently, the micro-projection becomes a kind of new customer goods with develop of mobile-display technology. At the same time, the micro-projection based on LED becomes more and more popular in projection marketing. Micro-projection is a kind of image display technology including DLP, LCo S and LCD based on different kinds of special light modulator. DLP is one of the most popular technology and its core component is DMD which produced by Texas Instrument.The DLP projection based on LED source includes two parts: illumination and imaging,and the illumination part is the light engine of projection system. The angular distribution of LED follows Lambertian distribution, so its light spot on detector is nonuniform and irregular and can’t be used in projection system directly.Because the DMD chip is rectangular and the spot on chip must be uniform, there is a need using optical component to shape the beam of LED. The illumination part of projection includes four parts: beam collimation, beam homogenization, beam combination and beam condensation.This paper is about design and simulation of illumination of DLP projection based on LED source. In collimation part, the related parameters are calculated and the CPC models are established by Tracepro. A kind of new total internal reflection lens with micro-lens is design by Light Tools to make the rectangular light spot. There is also a kind of free-form total internal reflection lens designed. The profile coordinates of free-form TIR lens are calculated by Matlab to make TIR lens model by rotation in Pro/Engineer, finally, the simulation is made by Tracepro. During the calculation of TIR lens, the source is regarded as ideal point source, so both of the ideal point source and extended source should be considered and simulated to ensure if the real size of LED can be used in DLP system. The simulation shows that the free-form can be used in DLP system. At last, RGB channels are used in DLP projection system, and the real size is set to LED source, the uniformity and transmitting can meet the need of projection illumination...