Multifunction electromagnetic actuator and camera control apparatus emloying same

摘要

A multifunction electromagnetic actuator particularly suited for use in controlling exposure and focus in a photographic camera, includes a permanent magnet mounted between and spaced slightly from two substantially parallel plates of ferromagnetic material, to form a pair of magnetic gaps. First and second planar armatures comprising flat coils carried by sheets of insulating material are respectively mounted in the first and second magnetic gaps for movement in response to current applied to their respective coils. The resulting electromagnetic actuator is a compact powerful actuator capable of independently controlling two functions. In a photographic camera, the first armature of the multifunction actuator is coupled to a shutter to control exposure, and the second armature is coupled to a moveable lens element to control focus.