Patent ID: 6565270
Filing Date: 2003-05-20
Classification: G03B,H04N

Abstract:
A light quantity control unit comprising:a base plate having an aperture forming an optical axis; a blade member disposed on the base plate to face the aperture for regulating a condition of the aperture; a coil formed into a cylindrical shape with two ends and arranged on said base plate parallel to the optical axis; a magnet rotor disposed near the coil parallel to the optical axis and polarized with two magnetic poles; a pair of magnetic force inducing members, each having a base end part disposed at each of the two ends of said coil, and a leading end part extending from the base end part perpendicular to the optical axis and having an equal thickness throughout an entire length thereof, said leading end parts surrounding said magnet rotor at a middle area thereof and providing two mutually opposed equal magnetic poles for rotating said magnet rotor; and regulating means formed at the base plate for regulating a rotation of said magnet rotor to swing at a predetermined angle between the two magnetic poles formed in the magnetic force inducing members.