Electromagnetic shutter for lens

Abstract

An electromagnetic shutter for a photographic lens is disclosed. The shutter comprises an optical stop mounted between focusing elements with a flap mounted for rotating substantially along one side of said stop. The flap has a first position in which it blocks the passage of light through the stop and a second position in which it is removed therefrom. An electromagnetic means for rotating the flap from its first position to its second position comprises a permanent magnet mounted on said rotatable shaft and an electromagnet having a horseshoe-shaped core with two poles which surround the permanent magnet. When the electromagnet is energized, the magnetic field produced causes said permanent magnet and attached shaft to rotate, thereby rotating the flap from its first position to its second position and thereby opening the shutter. A spring returns the flap to its first position when the electromagnet is not energized, thereby closing the shutter.

Dependencies are inferred from the claim text.