To increase the number of light shielding blades in a light amount control device without enlargement of the device in a radial direction.
A light amount control device 19 includes: a base member 32 having a fixed aperture 31a; a driving member 32 rotated around the fixed aperture relative to the base member; and light shielding blades 33 and 34 which are arranged in plural in a circumferential direction of the fixed aperture and are turned relative to the base member by the rotating driving member to change the size of a light amount control aperture. The plurality of light shielding blades include a plurality of first light shielding blades 33 turning in a first direction due to rotation in one direction of the driving member and a plurality of second light shielding blades 34 turning in a second direction opposite to the first direction due to rotation in the one direction of the driving member.
Atsushi Mizumoto
Hirayama Tomoya