提出一种由平面LED阵列与高漫反射率自由曲面构成的间接照明方式。基于LED光源与理想漫反射表面的朗伯特性, 构建照明系统的数学模型。根据目标平面预期的光强分布, 建立一组微分方程, 利用数值方法求解得到漫反射自由曲面的面形轮廓, 通过光学软件对该漫反射光源系统实体模型进行非序列光线追迹仿真, 模拟结果显示检测区域辐照均匀度达到90%以上, 验证了该方案设计均匀照明光源的正确性与有效性。

An indirect illumination pattern with flat LED array and diffuse reflection freeform surface was proposed. Based on the Lambertian characteristic of LEDs and ideal diffuse surface, a mathematical model was constructed. A set of differential equations were established according to the expected energy distribution on the target plane. Through solving these equations numerically, the outline of the diffuse surface was obtained. By importing the entity model of the diffuse reflection illumination system into optical software to perform non-sequential ray tracing, the simulation result shows that the irradiance uniformity of the detection area is above 90% and demonstrates that the proposed method is correct and effective.