Optical Design in Packaging and Illuminating System for High Power Light-Emitting Diodes for Projection system

摘要

High power Light-Emitting Diodes are used as the illuminating system of the portable projection system more recently. Through analysis the optical structure of high-power LEDs, the LED's optical model and package were simulated and the luminous intensity distribution diagram was obtained. According to the rectangle illuminating requirement of the projection system (the ratio of illuminating length and width is 4:3), a pair of reflective fly eye lens illuminating system with the characteristic of high-bright and uniformity illuminating was designed. Experimental results showed that greater than 85% of the uniform degree of illumination, the output light energy utilization ratio of 80% and the angle of divergence of 38 degree on the object plane were obtained while using the white LED as the light source with illuminating model of Lambertian distribution, luminous flux of 1201m and angle of divergence of 150 degree. This system will be fit for the portable and mini-projection system and other small light-emitting area, uniformity illuminating projection system.