为了使微型投影系统既保持结构紧凑又能获得良好光学性能, 本文根据柯拉照明原理提出一种基于LCoS和LED 光源的照明方案。该方案修改了基本的柯拉照明结构, 通过合理设置孔阑, 能在LCoS 面上得到均匀光斑, 而且照明部分光学元件非常简单, 整体尺寸大大减小。本文分别使用球面和非球面两种照明系统进行仿真对比, 球面系统空间均匀性86%, 非球面系统空间均匀性95%。基于非球面方案的整机系统能量效率达到9.94%, 屏幕均匀性大于90%, 光学模组的厚度在9 mm 以内, 非常适合于内嵌式投影系统。

To keep micro projection system compact and highly efficient, an illuminating system is proposed based on LCoS and LED. This system follows the principle of Kohler illumination. By modifying Kohler illumination system and setting the rational stop, uniformity lighting zone can be got on the LCoS plane. Besides, this system becomes simple and compact. Spherical lens and aspherical lens are used in this illuminating system respectively. And simulation results show that illumination efficiency is 86% for spherical lens and 95% for aspherical lens. When using aspherical lens, transmission efficiency of the whole projection system is 9.94% and spatial uniformity is above 90%. The thickness of optical module is less than 9 mm.