Abstract: A light quantity adjusting device includes a substrate having an optical path aperture, a blade located on the substrate to adjust the quantity of light passing through the optical path aperture, and an electromagnetic driver that drivingly opens and closes the blade. The electromagnetic driver includes a rotor shaft, an exciting coil, and a frame that rotatably bears the rotor shaft. The rotor shaft includes a pointed first shaft end and a cylindrical second shaft end. The frame has a conical bearing recess that supports the first shaft end and a cylindrical bearing hole that supports the second shaft end. The electromagnetic driver is located so that the first shaft end of the rotor shaft is closer to the substrate than the second shaft end. An arm is coupled to the first shaft end of the rotor shaft to transmit an opening and closing driving force to the blade.

Abstract: A light quantity adjusting device includes a substrate having an optical path aperture, a blade located on the substrate to adjust the quantity of light passing through the optical path aperture, and an electromagnetic driver that drivingly opens and closes the blade. The electromagnetic driver includes a rotor shaft, an exciting coil, and a frame that rotatably bears the rotor shaft. The rotor shaft includes a pointed first shaft end and a cylindrical second shaft end. The frame has a conical bearing recess that supports the first shaft end and a cylindrical bearing hole that supports the second shaft end. The electromagnetic driver is located so that the first shaft end of the rotor shaft is closer to the substrate than the second shaft end. An arm is coupled to the first shaft end of the rotor shaft to transmit an opening and closing driving force to the blade.

Abstract: Actuation device of the invention is used for opening and closing blades for defining light path, i.e. a diaphragm of a camera. The actuation device includes an axle with a permanent magnet, a frame for rotationally receiving the permanent magnet, a hollow magnetic circuit member to retain the frame, and a sensor. Actuation and brake coils are wound around the frame. The actuation coil operates to rotate the permanent magnet, while the brake coil operates to stop rotation of the permanent magnet operated by the actuation coil. The sensor senses the angular location of the permanent magnet. A plurality of terminal pins is arranged on the frame between the actuation and brake coils, so that the ends of both coils can be attached to the desired pins. Also, a printed board attached to the terminal pins is provided with test terminals thereon, so that the device can be tested without causing damage to a terminal section of the printed board.