Design of target imaging zoom system for flight simulator

The principle of a flight simulator and its implementation are described. Design of a zoom lens for target imaging in the flight simulator is discussed. It is shown that the conjugate distance of a moving lens group (including the zooming group and the compensating group) reaches to its extreme value when the magnification of the lens group equals to -1. At this point, by means of a smooth transition between two possible cam curves of the compensating group, the group's power can be made to contribute to the magnification variation of the zoom system, resulting in a reduction of the moving scope of the cam curve and the size of whole system. Optimization of the zoom system is achieved using a developed optical CAD program. A scheme is proposed to adjust the cam curve according to the best focus of the system, which is successfully implemented in the target imaging zoom system.