高效抑制斜入射光线Fresnel反射的均匀扩散板设计

针对无导光板LED平板灯具设计中常规扩 散板对斜入射光线透过率低的问题,基于几何光 学和Fresnel公式,设计了一种具有高效抑制斜入射光线Fresnel反射的表面微结构扩散板, 并推导了获得 高光传输效率的三棱柱微结构参数计算公式。采用Solidworks软件进行建模,并结合TraceP ro软件对所设计 的扩散板进行光线追迹仿真,分析了扩散板微结构参数对光传输效率和照明面照度均匀度的 影响。结果表 明,入射表面微结构不等腰三棱柱的尺寸和形状、出射表面半凹球面微透镜直径对斜入射光 线传输效率都 有较大影响；参数优化后的扩散板,在距离出光面 1mm处的照明面上的光传输效率为0.92,照度均匀度为 96.8%,并且不同距离照明面上的照度均匀度均能达到80%以上 。根据理论分析得出的优化参数制作扩散板,得到传输效率为0.91。

Design of uniform diffuser plate for oblique incident light with high-performance Fresnel anti-reflection microstructure

In order to improve the low transmittance of the oblique incident lig ht in the conventional diffuser plate,while in the design of LED lamps and lanterns witho ut light guide plate,based on geometrical optics and Fresnel formulas,the surface microstruct ures of diffuser plate with high-performance anti-reflection properties for oblique incident li ght are designed. Parameter formulas of three prismatic microstructures for high efficiency light transmission are derived theoretically.Diffuser modeling using Solidworks software,the inf luence of micro-structural parameters of diffusers on light transmission efficiency and i lluminance uniformity on the lighting surface are analyzed by ray tracing simulation using TracePro software. The results show that not only the size and shape of non-isosceles prism on the surface of light incident side can but also the concave spherical microlens diameter on the surfa ce of light exit side can influence the obliquely incident light transmissi on efficiency greatly.At 1mm distance from the diffuser surface of light exit side,optimization of parameters makes the li ght transmission efficiency be 0.92and the illumination uniformity be 96.8%,and the illuminatio n uniformities at different distances from the diffuser surface of light exit side can all reach m ore than 80%. The diffuser plate according to the optimal parameters obtained by theoretic al analysis is fabricated and the transmission efficiency of 0.91is achieved.