| 摘要 |
A light amount adjustment device capable of operating shutter blades and a light amount adjustment member by a common drive source, while preventing light incident through an aperture from being momentarily interrupted by the shutter blades when the light amount adjustment member advances to and retreats from the aperture. After a drive member's cam shaft is moved by an energized actuator to a position where an ND filter advances to the aperture, the actuator is deenergized and the cam shaft is moved by a spring force to a position where the ND filter advances to the aperture. After the cam shaft is moved to a final position by the energized actuator, the actuator is deenergized and the cam shaft is moved by the spring force to a position where the ND filter retreats from the aperture. During this time, the shutter blades open and close on outside of the aperture. |
