Theoretical Analysis and Experimental Test of a Mechanical Shutter for Frame Camera

Abstract

Frame camera is widely applied in aviation photography. The disadvantage of frame camera is smearing. In order to reduce the smearing, a mechanical shutter is implemented to control the exposure time precisely. In this paper, the principle of a mechanical shutter based on rotary solenoid was analyzed. The control sequence was analyzed to achieve exposure time precisely. A experimental mechanism is set up to measure the closing time, close delay time of a home-built mechanical shutter. The torque of solenoid, the moment of inertia of shutter blade and the voltage that affected the closing time were analyzed. Both theoretical analysis and experimental data indicated that the shortest closing time of this mechanical shutter is 2.8ms. This mechanical shutter has small volume, light weight, simple structure and low power consumption, which is very suitable for airborne frame camera.