为了实现微型数字光处理(DLP)投影仪的超短投影距离的目的，先根据成像关系计算构建了非球面光学曲面的面型，再对投影镜头整体优化，设计了一个含有两片奇次多项式非球面的广角投影物镜。镜头的物方F=2，焦距4 mm，像方视场角128°，像方0.4 lp/mm（截止频率）处调制传递函数(MTF)大于0.6，最大畸变的绝对值0.9%，镜头总长100 mm，最大口径Φ=80 mm。设计结果表明，该设计方法可以使大角度、超短投影距离的投影镜头摆脱常用折反射式结构，全透射式的光学结构可以真正实现发光二极管光源照明DLP投影仪的微型化、投影距离超短化。

A wide field of view(FOV) lens，containing two odd polynomial aspheres, is designed to get a digital light procession(DLP) projector with a ultra-short throw ratio. The aspheres are calculated and fitted, then the lens is optimized totally. The lens has a F-number of 2, a focal length of 4 mm, a FOV of 1280, a maximum dis? tortion of 0.9%, a total length of 100mm, and a maximum cross-section diameter of Φ = 80 mm. And the modula? tion transfer function (MTF) is above 0.6 at 0.4 lp/mm (cutoff frequency) of all fields. The designing results indi? cate that the method can be applied to design a wide FOV and ultra- short totally refractive (TR) projection lens, which can substitute for the commonly used hybrid refractive-reflective (HRX) structure. This kind of TR lens can also be applied to mini light emitting diode DLP projectors with an ultra-short TR.