光子学报, 2016, 45 (2): 0222002, 网络出版: 2016-04-01
用于LED广告灯箱的自由曲面大角度透镜设计与仿真
Design and Simulation of Freeformsurface Large Angle Lens for LED Advertising Light Boxes
自由曲面透镜 大角度 均匀照明 出光效率 LED LED Double freeformsurface lens Large view angle Uniform illumination Light efficiency
摘要
基于能量守恒定律和网格划分法,设计了一种实现LED阵列近场均匀照明的自由曲面大角度透镜,其内曲面为椭圆形曲面、外曲面为自由曲面.根据能量守恒定律建立映射关系,对光源和目标面进行网格划分,并结合折射定律,迭代求解出外自由曲面数据点.分析了椭圆形内曲面的长短轴比值对透镜菲涅耳损耗和照度均匀性的影响.结果表明:短轴与长轴的比值在0.35~0.55时,出光效率和照度均匀性最佳.通过反馈优化法对LED阵列进行优化,重新划分网格,使叠加部分光照度减弱,提高了整体光照均匀性.仿真结果表明:仅对透镜外自由曲面的面型数据点进行优化,在目标面高度为80 mm,透镜出光角度为157 °时,优化后的整体光照均匀度由优化前的0.40提高到0.84,出光效率大于0.9.
Abstract
Based on the law of conservation of energy and the mesh generation method,the freeformsurface large angle lens was designed to achieve a nearfield uniform illumination of LED array, whose inner surface is elliptical, the outer is freeformsurface. According to the mapping relations established by the law of conservation of energy, the mesh generation of the light source and the target surface was realized. Then, the refraction law was combined with the iteration to solve the freeformsurface data points. We analyzed the influence of the short axis and long axis ratio of the elliptical inner surface on the lens Fresnel loss and uniform illumination. The researches show that it can be obtained a high light efficiency and an optimum uniformity of illumination when the ratio is in the range of 0.35~0.55. Through the feedback optimization method to optimize the LED array and redivide the grid , the light intensity superimposed part is weakened and the overall illumination uniformity is improved. The simulation results show that when the height of target plane is 80mm and light angle is 157°, the illumination uniformity can be increased from 0.40 to 0.84 after the optimization of the freeformsurface data points,and the efficiency is greater than 0.9.
潘诗发, 郭震宁, 颜稳萍, 廖炫, 甘汝婷, 林木川. 用于LED广告灯箱的自由曲面大角度透镜设计与仿真[J]. 光子学报, 2016, 45(2): 0222002. PAN Shifa, GUO Zhenning, YAN Wenping, LIAO Xuan, GAN Ruting, LIN Muchuan. Design and Simulation of Freeformsurface Large Angle Lens for LED Advertising Light Boxes[J]. ACTA PHOTONICA SINICA, 2016, 45(2): 0222002.