提出了一种基于曲面能量映射的反馈优化设计方法,通过预先计算目标面能量分布趋势重新分配目标面网格单元,构建新的自由曲面透镜面型。采用该方法设计并分析比较了一系列透镜,仿真发现:当目标面半径与目标面高的比值(DHR)为2、透镜高和LED宽度的比值从1∶1变化到1.5∶1时,照度非均匀性下降了8.97%~11.95%;当透镜高和LED宽度的比值为1.5∶1、DHR从1.8变化到2.2时,照度非均匀性下降了7.60%~16.49%。所提方法能有效改善扩展光源下目标面的照度均匀性,设计过程不依赖于仿真软件,迭代次数少,简便易行。

A feedback optimization design method based on surface energy mapping is proposed herein. By pre-calculating the energy distribution on the target surface, the target surface mesh unit is redistributed to build a new free-form surface lens profile. A series of lenses is designed using this method, and the simulation results show that when the ratio of the target surface radius to height (DHR) is equal to 2 and ratio of the lens height to the LED width changes from 1∶1 to 1.5∶1, the nonuniformity is reduced by 8.97%-11.95%. Moreover, when the ratio of lens height to LED width is 1.5∶1 and DHR changes from 1.8 to 2.2, the nonuniformity is reduced by 7.60%-16.49%. Thus, the proposed method can effectively improve the illumination under an extended light source. The design process does not depend on the simulation software utilized, and it is simple and easy. The number of iterations is small.