Structural design of zoom system based on linear motor

摘要

The shooting mode of camera system has evolved from fixed focus to zoom photography. And compared with the fixed-focus photography, the zoom system not only has fast field of view switching function, but also has a strong ability in the pursuit of extreme detail resolution. The newly proposed linear motor-driven zoom technology completely eliminates some inherent drawbacks of the traditional method. Based on this method, this paper focuses on an achievable mechanical structure of linear zoom camera. The relative positions of the four lens components are reasonably arranged, and two stepping motors are selected as the power sources. Modal analysis is used to ensure that the fundamental frequency of optimized system is reasonable. The experimental results show that the fundamental frequency is increased from 310.63 Hz to 544.4 Hz, so the optimized structure can avoid the oscillation frequency of external devices. Considering the harsh engineering environment of zoom camera, the thermal deformation and displacement parameters under the impact of high and low temperature loads need to be tested urgently. According to the total length of this system and deformation of the front and rear fixed groups, we can roughly get the offset value of the optical axis. The final analysis results show that the off-angle of the optical axis in the specified direction does not exceed 50 μrad, and initially meets the design specifications.