US Patent 7420753 Rotatable lens set

A lens set assembly comprises an object side facing an object, an image side facing an image generated by the lens set, and a plurality of lens sets disposed from the object side to the image side sequentially. When the lens set assembly is used, the lens sets are all disposed along an optical axis. When the lens set assembly is not in use, the lens set adjacent to the image side rotates about an axis perpendicular to the optical axis to depart from the optical axis, and the other lens sets move toward the image side.