Design Of Visible And Near-infrared Dual Zoom Detection System

This thesis briefly describes the development status of multi-band optical systems,and analyzes basic principle of the mechanical compensation zoom system;the influence of cam curve pressure angle on cam rotation is obtained by force analysis of guide screw;in the design of the visible zoom optical system,if the magnifying lens group moves in a straight line and the compensating lens group moves in a curve,the pressure angle of the compensating curve fitted by dynamic optics principle is more than 50 degrees,which can not meet the requirement of the pressure angle;on the basis of unchanged original optical structure,a method to reduce the pressure angle of cam curve of zoom system is proposed.The pressure angle of cam curve made by this method is less than 37°,which effectively reduces the pressure angle of cam curve.According to the requirement of the same zoom ratio of the two systems,the cam curve of near infrared zoom system is fitted;finally,the installation and adjustment method of the zoom system is described,and the optical axis of the dual zoom system is adjusted to be parallel.Through MTF detection and field experiments,the imaging quality of the zoom system in the whole zoom process is proved to be excellent.In foggy weather,the target image of 2500 meters is obtained.By comparing the imaging effect of single system with that of double zoom system,it is found that the imaging effect of visible and near infrared dual zoom detection system is better,and the original design goal is achieved.It is verified that the dual-band zoom system designed in this paper has certain engineering practical significance.