自由配光设计中的复合抛物面三维同步多表面方法

Compound Parabolic Concentrator-Simultaneously Multiple Surface Method for Rectangualar Optical Design in 3D Space

为实现LED朗伯光源的矩形配光,提出了一种基于"脊肋"法的三维同步多表面非成像光学设计方法。该方法根据给定的辐照度分布,先由复合抛物面(CPC)完成初级配光,将朗伯光源±90°的发散角缩小到45°,再在二维平面生成一对"脊"线,然后向两侧生长出"肋"线,生成两个曲面框架,最后利用由NURBS曲面算法构建出两个自由曲面实现目标配光。两个自由曲面的引入提升了设计的自由度,但也大大增加了设计难度。将该方法应用到矩形均匀配光设计中,仿真结果表明:在远场接收面上得到一个较规则的方形轮廓且光束半发散角约为3.66°,考虑反射损失后其光效仍高达63%以上,平顶均匀度高于0.96。

In order to achieve the rectangular irradiance distribution of LED lambertian source , a simultaneously multiple surface nonimaging optical design method is put forward which is called the “spine-rib” method.First it shrinks the divergence of the lambertian source from ±90°to 45°by a CPC, and then a couple of “spine” line is generated according to the prescribed irradiance distribution .Based on these lines there will be “rib” lines grown on to both side to get two surface frameworks .Finally, two freeform surfaces of the optical device are built by NURBS surface algorithm .The introduction of two freeform surfaces enhances the degrees of freedom which also improves the difficulty of design .Applied the method to the rectangular uniform light distribution design , simulation results show that ： a square contour will be formed on the far -field receiver and give a 3.66°ray half divergence angle .When the reflection loss is fully considered , the light energy utilization is still more than 63%, the flat-topped uniformity is higher than 0.96.