| 主权项 |
1. A light quantity adjusting device that adjusts size of a diaphragm opening centering on an optical axis of an optical system, the light quantity adjusting device comprising:
a first pair of rectilinear diaphragm blades configured to include a first rectilinear diaphragm blade and a second rectilinear diaphragm blade that are slidably arranged at positions opposing across the diaphragm opening in a direction moving closer to and separating from the optical axis on a plane orthogonal to the optical axis; a second pair of rectilinear diaphragm blades configured to include a third rectilinear diaphragm blade and a fourth rectilinear diaphragm blade that are slidably, centering on an axis parallel to the optical axis, arranged at positions opposing across the diaphragm opening in a direction orthogonal to a direction in which the first pair of rectilinear diaphragm blades move and in a direction moving closer to and separating from the optical axis; and a driving unit configured to adjust a size of the diaphragm opening by sliding the first, the second, the third, and the fourth rectilinear diaphragm blades as the two pairs of rectilinear diaphragm blades, wherein the driving unit drives the first, the second, the third, and the fourth rectilinear diaphragm blades so as to adjustably form and maintain a shape of an opening perimeter of the diaphragm opening in nearly similar shapes. |
