The influence of incident angle and aberration of the microlens array on the optical efficiency in pico-projector is analyzed. By modifying the relevant parameters, a method to optimize the optical efficiency and uniformity of the illumination system is proposed. By changing the profile of the freeform double lens used for the concentrator of LED source, the incident angle can be reduced, thus the efficiency loss caused by large angle incident can be reduced. In addition, two spherical relay lenses instead of the Fourier lenses are used as integral component after the microlens array, which is not only low cost, but also more flexible in controlling aberrations. After system optimization, the illumination efficiency and uniformity of the pico-projector system can reach 60.51% and 86.2%, which verifies the feasibility and validity of the theoretical analysis.

中文翻译：

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基于广义函数法和微透镜阵列的DMD微型投影仪照明光学设计

分析了微透镜阵列的入射角和微透镜像差对光学效率的影响。通过修改相关参数，提出了一种优化照明系统的光学效率和均匀性的方法。通过改变用于LED光源的聚光器的自由形式的双透镜的轮廓，可以减小入射角，从而可以减小由于大角度入射而引起的效率损失。另外，在微透镜阵列之后，使用两个球面中继透镜代替傅立叶透镜作为整体组件，这不仅成本低廉，而且在控制像差方面更加灵活。经过系统优化后，微型投影仪系统的照明效率和均匀度可以分别达到60.51％和86.2％，