| 摘要 |
PROBLEM TO BE SOLVED: To provide a light quantity adjustment device capable of controlling the aperture diameter of a diaphragm with high accuracy in a simple configuration without increasing an unnecessary drive load, and also capable of reducing drive noise.SOLUTION: The light quantity adjustment device includes a base member 101 equipped with rotary drive means 105, and a rotation member 102, provided so as to be able to rotate relatively to the base member 101 centering around the optical axis, for driving a diaphragm blade by rotating it using the rotary drive means 105. One of the base member and the rotary member is provided with a circular-arc engaged parts (101a, 101b) at two places centering around the optical axis, and the other is provided two engaging parts (102a, 102b) guided along each of the circular-arc engaged parts and fitted thereto. |
