依据LED点光源模型发光特性, 以特定尺寸圆目标屏获得均匀准直照明为目标, 采用Skew-Ray 追迹法描述光线和设计TIR透镜, 其中将透镜全反射区域进行简化处理, 主要通过折射区域的双自由曲面相互配合控制光线实现照明目标。经过对透镜设计结果与１ｍｍ×１ｍｍ 的LED扩展光源模型的组合进行非序列光线追迹模拟, 模拟结果表明在距离光源2m范围内特定尺寸目标屏所获得光能利用率至少可达到79.6%, 同时目标屏在近场和远场处照明均匀度可分别达到95.9%和83.9%, 若以±1°作为光线准直半角标准, 目标屏准直光线百分比可分别达到88.6%和73.8％。

Based on the luminous characteristics of the LED point source mode, the Skew-Ray tracing method is adopted to describe the ray and design TIR(Total Internal Reflection) lens for the goal to realize the uniform and collimated illumination on the circular target screen with specific size. The total internal reflection part of lens is simplified and the double freeform surfaces of the refraction part are mainly utilized to achieve illumination goal by cooperating with each other to control the direction of the light. In addition, the non-sequential ray tracing process was used to simulate the illumination process of the combination of the design result of lens and 1mm ×1mm light source model of LED. The simulation result shows that the energy efficiencies of the target screen within the range of two meters from the light source is at least 79.6%. And the illumination uniformity of target screen in the near and far fields get 95.9% and 83.9% respectively. If ±1° is regarded as the half angle standard of the effective collimated ray, the efficiencies of collimated ray for target screen in the near and far fields reach 88.6% and 73.8％respectively.