| 摘要 |
PROBLEM TO BE SOLVED: To provide an aperture diaphragm device capable of certainly keeping a set aperture diameter.SOLUTION: An aperture diaphragm device 10 has: a ring member 12 rotatably supported by a cylinder body 11 through which an optical path passes; a blade diaphragm mechanism 13 supported on the inside of the ring member 12; and an operation knob 14 connected to an outer periphery of the ring member 12, and exposed to the outside of the cylinder body through an operation aperture 15 formed on the cylinder body 11. The operation knob 14 has a knob shaft 20 connected to the ring member 12, a knob member 30 supported by the knob shaft 20 and capable of abutting on an outer surface of the cylinder body 11, and a pressurizing mechanism 16 for press-contacting the knob member 30 on the outer surface of the cylinder body 11. A stopper member 40 is connected to the knob shaft 20 so as to prevent the knob member 30 from coming off from the knob shaft 20. |
