一种基于LED扩展光源的均匀照明设计新方法

A New Optical Design Method of Uniform Illumination Based on Extended LED Source

为满足LED均匀照明要求,提出了一种实现面光源下自动优化的设计方法。根据点光源近似理论建立可实现均匀照明的反射器初始结构,用COB(Chips on board)型LED面型光源替代点光源,基于TracePro中Scheme语言编写了自定义均匀照明优化函数,实现了目标面上均匀照明的自动优化设计。模拟结果表明:在光源为直径20mm的朗伯体发光LED时,能够在300 mm处实现均匀照明,照明均匀度(平均照度与最大照度的比值)达到85%以上,光学效率在96%以上。本设计方法简单易用,具有广泛的应用价值。

To meet the requirement of uniform illumination, a new automatic optimization design method for LED extended source is proposed. According to point source approximation theory, a reflector for uniform illumination is established. With chips-on-board （COB） type LED source replacing point source, our approach is used to achieve uniform illumination on the target plane with optimized illumination function defined by the ＂scheme＂ language in TracePro. A Lambert emission of LED with diameter of 20 mm is used as simulation source. The result shows that our optimization method works well with uniformity （the ratio of average illumination to the maximum illumination） of 85% or more and optical coupling efficiency of 96% or more at the target plane 300 mm away from the source. This design method is easy and useful, with a wide range of applications.