机载大变倍比大视场中波红外连续变焦光学系统设计

Design of Airborne Mid-Wave Infrared Continuous Zoom System With Large Zoom Range and Large Field

针对机载光电侦察探测和跟踪吊舱大视场连续观察的应用需求,设计了一款大变倍比大视场连续变焦中波红外光学系统。该系统根据物像交换原则,采用正组补偿结构形式,变焦方式简单,变焦曲线平滑易加工实现,仅使用7片固定透镜和2片变焦透镜,即完成了变倍比为35倍,焦距13~460mm,短焦视场40.5°×33°的中波红外连续变焦光学系统设计。结果表明,该系统在各焦段MTF曲线均接近衍射极限,32lp/mm时均高于0.1,最短焦距全视场畸变小于4%,公差分配设计合理,且结构尺寸紧凑,变焦曲线行程短,对机载大视场连续变焦光学系统设计具有有益的参考价值。

Aiming at the requirement of large field and continuous observation for airborne optoelectronic detection and tracking apparatus, an optical system of mid-wave infrared continuous zoom system with large zoom range and large field is designed. Based on the exchange principle of object and image, the style of zoom is very simple, and zoom curve is realized easily by positive group compensator. The system is composed of eight pieces of fixed lens and two pieces of moving lens, which achieves 35 zoom ratio, 13--460 mm of focal length, and 40.5°×33° field of short focal length. The results showed that the MTF of every focal length is closing to the diffraction, which is upon 0. 1（32lp/mm）, distor- tion of all field on short focal length is below 4%, tolerance is reasonable, with compact structure, short zoom curve. This paper is beneficial to the design of airborne continuous zoom system with large field.