为了补偿双波段航空相机在复杂环境下产生的离焦，设计了一套调焦机构。该调焦机构通过采用蜗轮蜗杆和 偏心凸轮的传动方式，将凸轮的旋转运动转化为调焦镜的直线运动，解决了离焦问题。该机构具有传动比大、运行平 稳，结构紧凑，抗振、抗冲击，可实现自锁以及模块化等优点。通过计算可知，该机构的调焦镜的位移 精度为0.0026mm，满足使用要求。仿真分析结果表明，该方法具有可行性。

To compensate the defocusing of a dual-band aerial camera in a complicated environment, a focusing mechanism is designed. The mechanism compensates the defocusing by using a worm-gear and an eccentric cam to convert the rotation of the focusing cam into the straight line motion of a mirror. It has the advantages of high transmission ratio, stable operation, compact structure, antivibration, self-locking and modularization. The calculation result shows that its focusing mirror has a displacement precision of 0.0026mm and the simulation result shows that the method is feasible.