实现LED矩形均匀照明的透镜设计

Lens design for uniform illumination of rectangle area with LED

随着大功率LED发射光强的不断提高,采用单粒LED为光源的照明系统已得到普遍应用。设计一种以LED为光源实现矩形均匀照明的透镜,根据微分几何的理论建立透镜面型所满足的微分方程,然后根据能量映射关系和能量守恒定律建立面型与目标面坐标点之间的关系,并通过四阶龙格-库塔法求解微分方程得到面型数据,利用所得的面型数据在三维建模软件Rhinoceros中构建出所求透镜面型,并将透镜导入ASAP进行模拟。模拟结果表明:该光学系统效率达到94.01%,目标面照度均匀性优于92.73%。最后分析了自由曲面的连续性,指出能量映射关系决定着自由曲面的连续性。

Lens for uniform illumination of rectangle area with LED light source was designed.Based on differential geometry,a series of partial non-linear equations were constructed.According to the conservation law of energy,energy mapping relations between the source and the target plane were constructed.The points of the surface were obtained by solving the equations with fourth order Runge-Kutta formulas,and the desired free-form surface was got by curve fitting with Rhinoceros software.With ray tracing in ASAP software,the result indicates that the optical efficiency is more than 94.01%,and the illumination uniformity of the predetermined illumination area on the target plane is better than 92.73%.The continuity of the free-form surface was also analyzed,and the result shows that the continuity of the freeform surface is determined by energy mapping relations.