US Patent 8651754 Electromagnetic shutter

A shutter includes a driver ring, a plurality of shutter blades coupled to the drive ring such that movement of the drive ring transitions the plurality of shutter blades between an open position exposing a central aperture of the shutter, and a closed position blocking the central aperture, and a first stop and a second stop movable relative to the first stop. At least one of the first and second stops limits travel of the shutter blades.