基于折射率预补偿方法的扩展光源匀光照明二次光学设计

Secondary Optical Design for Uniform Illumination of Extended Sources Based on Refractive Index Pre-Compensation Method

扩展光源的二次光学设计对于开拓大功率发光二极管(LED)在照明领域的应用具有重要意义。分析扩展光源条件下匀光配光系统照明效果的退化原因,提出一种折射率预补偿方法,并基于该方法针对8mm口径的扩展光源设计匀光配光透镜。仿真结果表明:经该透镜配光后,目标面上的光斑塌边长度大幅减小,陡边性变好;有效照明区域增大,有效照明区域平均照度提升,归一化均方根进一步减小,照度均匀性明显改善;光线能量更集中于有效照明区域,照明效率显著提高。该方法原理简单,效果显著,为扩展光源实现匀光照明提供了一种新思路。

The study of secondary optical design of extended sources is significant in the applications of high-power light-emitting diodes in the lighting field.Herein,first,the causes of degradation in the illumination effect in light distribution systems for uniform illumination under extended source conditions are analyzed.Then,a refractive index pre-compensation method is proposed.Based on this method,a light distribution lens for uniform illumination is designed for extended sources with aperture of 8 mm.Simulation results show that the length of the collapse edge of the spot significantly decreases such that the slope improves with respect to the light distribution lens,and thus,the effective illumination area on the target surface increases.Consequently,the average illuminance of the target area increases.The normalized root-mean-square of the effective illumination area further decreases,and the uniformity of illuminance improves.The illumination efficiency improves because the light energy is able to further concentrate on the effective illumination area.This method provides a new approach to realize uniform illumination for extended source.