轻型双波段航空相机工作时所处的环境条件比较复杂，由于环境的变化，航空相机的焦平面会发生不同程度的偏移，为了保证其成像质量，需要对变化的焦平面加以校正，因此设计了一套调焦机构。该调焦机构选用的是蜗轮蜗杆副以及调焦偏心凸轮的传动方式，调焦偏心凸轮转动带动调焦镜组沿光轴方向平动，从而解决了航空相机的离焦问题。该调焦机构优化后的外形尺寸为96 mm×65 mm×62 mm。对该调焦机构在其有效的工作区间内进行了精度分析，并且对其进行了传动精度实验和晃动精度实验。实验结果表明该调焦机构的传动精度为3.5 μm，最大晃动误差在±3″以内，满足结构空间尺寸和调焦精度的设计要求。

The working environment of the lightweight dual-band aerial camera is very complicated. Due to the changes in the environment, the focal plane of the camera will produce different degrees of deviation. In order to ensure the imaging quality of the camera in the complex environment, it is necessary to correct the focal plane of the camera, so a focusing mechanism is designed. The transmission mode of the focusing mechanism is a worm-ear and a eccentric cam. The rotation of the eccentric cam drives the focusing lens moving along optical axis direction to solve the problem of aerial camera defocus. The optimized focusing mechanism has a shape size of 96 mm×65 mm×62 mm. The precision analysis of the focusing mechanism is carried out in the effective working range. The transmission precision experiment and the sway precision experiment are also carried out. The experimental results show that the transmission precision of the focusing mechanism is 3.5 μm, and the maximum sway error is below ±3″. The focusing mechanism meets the requirements of the structure space size and focusing precision.