基于数字光处理的短焦微型投影光学系统设计

Design of a short-focus micro-projection optical system based on digital light processing

摘要:

由于投影仪逐渐走向大众化，产品从原来的专业应用向个人或家庭应用迅速转变；为满足短焦微型投影小型化、高照度、低功耗等需求，设计了一款适用于0.3″单片数字光处理器的短焦微型投影光学系统；本文基于复眼透镜的匀光特性，利用复眼透镜匀化整形光源，结合棱镜转向的照明技术方案，完成了照明系统设计，分析了照明系统的光照度分布；其次，基于反远距结构的成像原理，结合非球面和像方远心技术，在缩短光路的基础上增大了成像系统的景深；最后，建立成像系统的仿真模型，分析成像系统的像质和公差；结果表明:照明系统在数字微镜器件上的照度均匀性为90.91%，整个系统的光效率达到了88.45%；成像系统长度为53.9mm，全视场达到67°，在93lp/mm处调制传递函数大于0.52，畸变小于1.0%；该系统具有结构简单紧凑、体积小、照度高等优点，满足要求。

Abstract:

As projectors are gradually becoming popular, the products are rapidly changing from original professional applications to personal or home applications; in order to meet the needs of miniaturization, high illumination, and low power consumption of short-focus mini-projection, a short-focus mini-projection optical system applicable to 0.3″ monolithic digital light processor is designed; in this paper, based on the homogenization characteristics of the compound eye lens, the lighting system design is completed by using the compound eye lens homogenization shaping light source, combined with the lighting technology scheme of prism steering, and the illumination distribution of the lighting system is analyzed; secondly, based on the imaging principle of the anti-telephoto structure, combined with aspheric and telecentric in image space technology, the imaging system increases the depth of field on the basis of shortening the optical path; finally, the simulation model of the imaging system is established, and the image quality and tolerance of the imaging system are analyzed; the results show that the illumination system has an illumination uniformity of 90.91% on the digital micromirror device and the optical efficiency of the whole system reaches 88.45%; the length of the imaging system is 53.9 mm, the full field of view reaches 67°, the modulation transfer function at 93 lp/mm is greater than 0.52 and the distortion is less than 1.0%; the system has the advantages of compact structure, small size, high illumination, and meets the requirements.