提出了一种基于朗伯型反射面的LED间接照明系统, 即LED光源出射的光全部通过朗伯型反射面反射后再照射目标区域, 该系统具有光源亮度均匀、灯具效率高等优点, 很好地解决了高亮度LED点光源给室内照明带来的眩光问题。首先提出了一种能够很好逼近朗伯反射面的复合型微结构表面, 并通过Lighttools光学仿真对其分布参数进行了优化, 使最终结果在不同光线入射角的情况下, 都具有较理想的余弦反射特性。在此基础上, 设计了整体光学系统, 使其实现了近180°范围的角度亮度的均匀性和高达84.7%的灯具效率, 验证了间接照明方法的可行性。

An indirect LED illumination system based on Lambert reflection was introduced. The lights from LEDs will be reflected by the Lambert surface before they go into target area. The system has advantages of uniform luminance and high light-efficiency, and can perfectly solve the glare effect brought by point-source property of LEDs. In this paper, a compound micro-structure surface which can approach Lambert surface, and then, the parameters of morphology were optimized based on Lighttools simulation. The result presents good cosine reflection law under different incident angle. Based on micro-structure surface an illumination system was designed to realize the uniformity of angular luminance in almost 180° range and high light-efficiency up to 84.7%, which confirms the feasibility of indirect LED illumination system.