Aperture/shutter system and a stepper motor for use therein

摘要

An aperture/shutter system defining an optical path comprises a shutter mechanism operable at a first state to selectively block light along the optical path and a second state to allow light along the optical path; and a motor including a stator and an annular rotor. The rotor is rotably supported within the stator by a support that is (i) stationary with respect to the stator and (ii) engages an inner surface of the rotor. The rotor is coupled to the shutter mechanism to move the shutter mechanism between the first state and the second state.