本文提出一种基于虚拟目标面的 LED均匀光强透镜设计方法。该方法通过设置半球状虚拟目标面, 建立芯片与目标面的能量对应关系, 求得均匀光强透镜的外形, 利用光学仿真软件对设置的虚拟目标面半径对光强分布的影响进行讨论, 并结合本文提出的描述均匀光强透镜的整体均匀性的指标.光强平台均匀度和光强平台宽度比, 分析并最终确定合理的虚拟目标面, 得到符合设计指标的均匀光强透镜。仿真分析表明, 当透镜厚度和透镜设计目标角度一定时, 虚拟目标面半径值越大, 计算误差小, 透镜整体光强均匀度高; 当透镜厚度和虚拟目标面半径取恰当值, 透镜设计目标角度越大, 透镜整体光强均匀度越高。运用该方法设计了一款半角为 60°的均匀光强透镜, 其光强平台均匀度为 0.983, 光强平台宽度比为 0.859, 整体光强均匀度高, 符合设计要求。

A design method of LED uniform luminous intensity lens based on virtual target surface was proposed. Hemispherical virtual target surface was set to establish the energy relationship between chip and target surface, and get the shape of uniform luminous intensity lens. By optical simulation to discuss the influence of radius of virtual target surface to luminous intensity distribution, combining with uniformity of luminous intensity platform and ratio of luminous intensity platform width were proposed to describe lens overall uniformity index. A reasonable radius of virtual target surface was ultimately determined to get a uniform luminous intensity lens that meets the design indexes. Simulation and analysis show that the larger radius of virtual target surface, the smaller calculation error and higher luminous intensity uniformity of lens when the thickness of the lens and angle of lens design goal are constant, the larger angle of lens design goal, the higher luminous intensity uniformity of lens when the thickness of the lens and the radius of virtual target surface are reasonable. Using this method, a half-angle 60 degrees lens of uniform luminous intensity was designed. Its overall uniform luminous intensity is better, and uniformity of luminous intensity platform is 0.983 and ratio of luminous intensity platform width is 0.859, which meets the design requirement.