| 摘要 |
PROBLEM TO BE SOLVED: To provide a diaphragm device that reduces a reciprocating difference and allows the amount of light to be highly accurately adjusted without increasing the number of components.SOLUTION: A diaphragm device comprises: a plurality of stop blades that a rotation center member and a drive pin are fixed; a support member that supports the rotation center member so as to allow the stop blade to freely rotate; and a cam member that has a cam groove with which the drive pin of the stop blade engages. A prescribed direction to the diaphragm device is defined, and in the respective stop blades, a trajectory of a centre of gravity of the stop blade when the stop blade is driven is parallel to the prescribed direction, and does not cross a straight line passing through a rotation centre.SELECTED DRAWING: Figure 1 |
