Optical design of high-magnification digital zoom lens

To improve the performance of zoom systems and achieve a good imaging quality in WFOV, and to simplify the mechanical structure for the convenience of design, process and adjustment, a design concept that combines the conventional spheric optics with the aspheric optics was introduced in the design of zoom lens. A zoom lens system with f′= 6.9mm～91.6mm and FOV= 5°～60°was designed by choosing four positions of focal length for the design calculation and ZEMAX as the optical design software. The whole system is composed of 8 lenses in 4 sets，including 3 aspheric surfaces. The results show that the zoom lens has the characteristics of high magnification and large field of view, and the use of aspheric surface makes the structure compact and the imaging quality high.