Variable focus lens system for camera or other optical device, uses step zoom technique, in which lens assembly has number of lens elements mounted on a transverse slide

摘要

Between the image (1) and the image sensor (3) is a transverse assembly (2) which holds a number of lenses, each of which has different characteristics. When the user wishes to zoom in or out, the transverse assembly is moved (4) to select a different lens. At the same time the distance between the lens and the sensor is changes (5) to allow for the change in focal length.