为了使发光二极管(LED)光源在近距离内满足特定角度范围内出射的高效照明, 提出了一种基于光学扩展量的复合椭球面聚光器(CEC)的设计方法。首先, 根据LED 光源的发光特性和非成像光学中的光学扩展量守恒理论, 建立了CEC 的母线方程, 进而依据边缘光线理论和几何光学中的光线追迹原理, 设计了CEC 结构的前后表面面型。最后利用光学设计软件ZEMAX 对所设计的系统进行光线追迹仿真, 结果表明在CEC 出口处可获得的角度大小为51.6°, 在距离出口后4 mm 处8 mm×8 mm 大小的探测器上可利用的光能达到69%。模拟仿真与理论计算结果基本吻合, 证明了该设计方法的合理性。整个系统尺寸较小, 为实现聚光系统的小型化和简单化提供了一种有效的设计方案。

A design method for Light-emitting Diode (LED) Compound Elliptical Concentrator (CEC) is proposed based on optical extent, in order to satisfy specific emergent angle and high efficient illumination in short distance. Firstly, the CEC generatrix equations are derived according to the optical properties of LED light source and the optical extent conservation theory in non-imaging optics. Then the front and rear surface types are analyzed in the light of the edge-ray principle and the ray tracing theory in geometrical optics. Finally, the designed system is ray tracing simulated in optical software ZEMAX. The results show that, the emergent angle is 51.6° and the light energy utilization efficiency reaches 69%, in the scope of 8 mm×8 mm detector that is 4mm away from the CEC exit aperture. The reasonableness of the method is proved by comparing the simulation results with the theoretical calculation. Using the small size-concentrator is an effective way to realize system’s miniaturization and simplification.