紫外光LED固化面光源光学系统设计

为解决紫外光LED固化面光源光斑均匀性差及辐照强度低的问题,提出一种阵列式紫外光LED固化面光源光学系统的设计方法。基于几何光学及菲涅耳定律等相关理论,完成近朗伯光型LED透镜自由曲面轮廓线的推导,结合理论公式计算出透镜阵列排布时透镜之间的最佳间距。结果表明:透镜有效控制了光线的发散,提高了阵列面光源所产生光斑的辐照强度及照度均匀度,使阵列结构更加紧凑。当光源半值角分别为27.5°和15.5°时,照度均匀度分别为95.3%和98.6%,辐照强度分别是理想朗伯型光源阵列的2.5倍和6.4倍。进一步分析了工作距离和芯片形状及其尺寸对面光源光学系统的影响,并通过实验对模拟结果进行验证,为紫外发光二极管的应用及光学系统设计提供了一定的理论依据。

Optical System Design of LED Area Source for Ultraviolet Curing

In order to enhance the uniformity and irradiation intensity of UV-LED area curing, an optical system for array UV-LED curing area-focusing was constructed. Based on the geometrical op-tics and Fresnel’s law, the derivation of lens contour was completed, and the optimum resolution of lens array was calculated. The results show that the light is controlled effectively by lens, the irradi-ance intensity and irradiance uniformity of area-focusing are improved, while the structure of array is more compact. When the half value of the light source is 27. 5° and 15. 5°, the uniformity is 95 . 3% and 98 . 6%, and the irradiance intensity is 2 . 5 and 6 . 4 times larger than Lambertian opti-cal source array. The influence of working distance and the parameters of chip on area-focusing opti-cal source system is also analyzed, and the simulation results are verified by experiments. These re-sults provide theoretical basis for the application of UV-LED and optical design.