为设计一款可用于不同规格的投影机的通用型短焦投影镜头，整合了应用较为广泛的几款主流机型的光学特征参数，以不同机型内部光学引擎的的不同尺寸的分色合色棱镜作为镜头的一部分，建立多重结构，并根据不同机型参数合理确定了镜头的像高、分辨率、后工作距等设计指标，设计了一款短焦投影镜头，可用于0.63英寸(1.6 cm)~0.8英寸(2.03 cm)芯片且基于单DMD或3LCD技术的投影机，投射比为0.8: 1~0.95: 1。分析了短焦投影镜头中较难处理的照度和畸变问题，最后给出了可行的解决办法,并对光学系统进行了公差分析。

To design a universal short-focus projection lens for different sizes of projectors, the characteristic optical parameters of which were integrated, and the different sizes of the prism inside the optical engines of different types of projectors were put into the multi-configuration of the system as one part of the lens. The image height, resolution and back operating distance were set reasonably according to different parameters of the chips. Finally, a lens whose throw-ratio was 0.8: 1 ~0.95: 1 for every suited projector based on 1 digital micromirror device (DMD) or 3-liquid crystal display (LCD) technology was designed, in which the chip was from 0.63 inch to 0.8 inch. The illumination and distortion problems difficult handled in short-focus projection system were analyzed, and an effective solution was provided. Furthermore, the tolerance analysis was conducted.