Ultra-Slim Zoom Lens Design for a 3x Mobile Camera

摘要

This study presents an ultra-slim zoom lens with a zoom ratio of 3× for a mobile camera by usinga prism. The lens modules and the ray aberrations are applied to the initial design for a four-groupinner-focus zoom system. An initial design with a focal length range of 4.4 to 12.76 mm is derived byassigning appropriate first-order quantities and lower-order aberrations to each module along withthe constraints required for optimum solutions. By using an optimization design method ratherthan analytic approaches, we separately designed a real lens for each group at given conjugatesand then combined them to establish an actual zoom system. The combination of the separatelydesigned groups results in a system that satisfies the basic properties of the zoom system consistingof the original lens modules. In order to fold the ray path, we directly inserted the right-angle prismwithout any lens in front of the first group. This configuration resulted in a more compact zoomsystem with a depth of 7 mm. The finally designed zoom lens has an f-number of 3.5 to 4.5 and isexpected to fulfill the requirements for an ultra-slim mobile zoom camera.