Design and Performance Analysis of Focusing and Image Motion Compensation Mechanism for Low Light Level Multispectral Imager

According to the structural characteristics and working conditions of a low light level multispectral imager, an integrated device of focusing and image motion compensation is designed to be smaller, better imaging quality and low illumination imaging. The focusing function is realized by the screw nut and the wedge slider. The realization of the motion compensation function depends on the voice coil motor, and with the dynamic and static two-stage locking device. The reliability and impact resistance of the mechanism are significantly improved. The overall dimension of the structure is 349 mm×192 mm×174 mm, the focusing range is ±2 mm, the image motion compensation is 3 mm, the focusing resolution is 0.05 μm, and the actual positioning accuracy is ±5.7 μm. The first order mode is 225 Hz, which is consistent with the result of finite element simulation. The results of the sine vibration test and random vibration test meet the requirements of the technical indicators. It shows that it has good dynamic stiffness and can effectively avoid the resonance phenomenon. The focusing and image motion compensation mechanism has small size and high structural strength, which meet the working conditions of low light level cameras.