LIST OF FIXED FIXED AND CONSTANT BUILDING FOR AUTO FOCUS APPLICATIONS

摘要

A lens with a fixed focal length comprising including a first front lens-element group, a second lens-element group, a third lens-element group, a fourth lens-element group, and a fifth back lens-element group. Relative to an imaging plane in a lens barrel and both the focusing front group and the focusing back group are movable jointly relative to one another and to the lens-element groups arranged in a stationary manner in order to focus the lens on objects at different object distances. The front lens-element group has a positive refractive power and the central group and the back lens-element group have a negative refractive power.