Optical Zoom System Design for Compact Digital Camera Using Lens Modules

By use of lens modules and third-order aberration theory, a new design approach can be applied to the three-group inner-focus zoom system. The optimum initial design satisfying the specific requirements and its real lens design from the lens modules are presented. An initial design with a focal length range of 4.3 to 12.9 mm is derived by assigning appropriate first-order quantities and third-order aberrations to each module along with the constraints required for the optimum solutions. By using an automatic design method rather than analytic approaches, we separately designed a real lens for each group at given conjugates and then combined them to establish an actual zoom system. The combination of the separately designed groups results in a system that satisfies the basic properties of the zoom system consisting of the original lens modules. When the aberrations are balanced, the finally designed three-group zoom lens is expected to fulfill all the requirements of a compact digital zoom camera. PACS numbers: 42.15.Eq, 42.15.F