Abstract: The present invention relates to an electromagnetically driven shutter device for camera, so designed that a detecting means for detecting the displacement speed of the shutter member and the power supply means for supplying the driving energy to the shutter member are provided in such a manner that the output of the power supply means is varied in accordance with the output of the detecting means so as to maintain the displacement speed of the shutter member constant.

Abstract: An electromagnetic actuating device for controlling the opening and closing operation of a shutter includes a plurality of plate-like permanent magnets and yokes alternating in layers to form a plurality of magnetic paths, and a moving coil arranged to be movable in a space provided in said magnetic paths. The device is thus minimized in bulk and size, can be built into the shutter casing, and rendered operable with electrical energy consumption kept to a minimum.

Abstract: In the disclosed circuit, an electromagnetically driven shutter is opened and closed by an electromagnetic drive device. A detector senses the current through or the voltage across an exciting member of the electromagnetic drive. A drive circuit is controlled by a comparator which compares the output of a constant voltage source with the output of the detector. The drive circuit is regulated so that when the shutter is opened and closed, the current is maintained at predetermined values so as to always keep the shutter characteristics constant.

Abstract: An electromagnetic shutter control device for controlling opening and closing operation of the shutter of a compact folding camera includes a bobbin having a magnetic winding therearound, a stationary permanent magnet over which the bobbin fits for magnetically actuated movement in a longitudinal direction, and guide elements for constraining movement of the bobbin in the longitudinal direction only. The permanent magnet acts to maintain the bobbin in a normal position at the terminal end of its movement coinciding with the closed position of the shutter. Energization of the magnetic winding actuates the bobbin in order to thereby actuate the shutter to the open position. The bobbin and the permanent magnet are particularly formed with a rectangular configuration so that the electromagnetic control device may be shaped to enhance and facilitate the compactness of a camera with which it is utilized.

Abstract: In the drive system disclosed, a first power source supplies a driving current to drive a moving member of an electromagnetic shutter driving device in one direction or in the reverse direction a second power source device consisting of a DC booster circuit, a capacitor, etc.; a photo-to-electric converter circuit discerns the brightness level of an object to be photographed and controls the outputs of the first and second power source devices to shift between these two outputs. An automatic change-over supplies the output of the second power source to the electromagnetic shutter driving device when the level of the output of the photo-to-electric converter circuit is equal to or above a predetermined level and supplies the output of the first power source to the electromagnetic shutter driving device when the output level of the photo-to-electric converter circuit is lower than the predetermined level.