Design Of LED Illumination System And Research Of Illuminance Distribution Of LED Arrays

The main two aspects of LED illumination system, intensity and illuminance, are researched in this thesis by the support of Fujian institute of optical technology and Shanghai Xinlu Corporation.Firstly, the optical model of White LED is created with the optical modeling software according to theoretical model of LED chip . The result of raytrace shows that the intensity distribution of the LED optical model is consistent with that of experiments of true LED. Furthermore, rays coming out of LED is sorted and analyzed in detail.Secondly, the intensity of normal direction is enhanced by the combination of the LED and parabolic reflector after comparison of different kinds of nonimaging components. Due to the relative position of LED and parabolic reflector, the intensity of normal direction has two peek values. The reason of the two peek values is different and the second peek value is greater than the first peek value. The relationship between the insertion depth and the peek value of intensity of normal direction is obtained.Thirdly, illuminance distribution of LED arrays is researched with the combination of theoretical analysis and simulation of computer. Simulation results and theoretical analysis show that the illumination uniformity is significantly affected by the distance between LEDs each other in the LED array. In addition, the formula of illuminance distribution of road-surface illuminated by LED arrays and the pertinent curves are obtained. The method of analysis in this thesis can be useful in the application of LED in the illumination engineering.