| 摘要 |
PURPOSE:To perform optional exposure control to extend the range of photographing, by arranging a movable coil member for driving an aperture shutter blade and a controlling movable coil member for controlling the extent of movement of said movable coil member between a fixed permanent magnet and a yoke. CONSTITUTION:In the first movable coil member 6, a pin 10a of an aperture control lever 10 is held in the middle position of a cam groove 8 normally. When electic power is supplied to the second movable coil member 7, which is provided a slight space apart from the first movable coil member 6, to turn the second movable coil member 7, the member 7 turns the aperture control lever 10 engaged with a recessed groove 9 through a pin 10b. When the second movable coil member 7 is turned counterclockwise, a shutter blade 14 is operated to the open side, and the manipulated variable of the aperture shutter blade 14 is determined by the extent of movement of the second movable coil member 7, and the extent of movement of the second movable coil member 7 is determined by the extent of movement of the aperture control lever 10 engaged with the cam groove 8 of the first movable coil member 6. |
