ABSTRACT Light-emitting diode (LED) modules can be flexibly disassembled and assembled and have inherent advantages in large-area lighting applications. In this paper, an efficient method is proposed to design an LED freeform lens array for direct lighting based on an adjustable Cartesian candela distribution. The Cartesian gradient candela distribution (CGCD) is adjusted and determined through the initialized design of a single freeform lens and a diffuser plate. The layout of the LED lens array can then be optimized by controlling the semi-angle of the light intensity distribution (SALI). A design example shows that the uniformity of the lens array increases by 11.63% through only a two-round iterative optimization. Both the simulation and experimental results are discussed to verify the proposed design. The freeform lens array is expected to expand the applications of mini- or micro-LED devices.

中文翻译：

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基于可调笛卡尔坎德拉分布的自由曲面透镜阵列设计

摘要 发光二极管（Light Emitting Diode，LED）模块可灵活拆装，在大面积照明应用中具有先天优势。在本文中，提出了一种基于可调节笛卡尔坎德拉分布设计用于直接照明的 LED 自由曲面透镜阵列的有效方法。笛卡尔梯度坎德拉分布 (CGCD) 通过单个自由曲面透镜和漫射板的初始化设计进行调整和确定。然后可以通过控制光强度分布的半角 (SALI) 来优化 LED 透镜阵列的布局。一个设计实例表明，仅通过两轮迭代优化，透镜阵列的均匀性就提高了11.63%。讨论了仿真和实验结果以验证所提出的设计。