| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical system capable of providing good images over the entire screen even when an aperture diameter of an aperture diaphragm is changed.SOLUTION: An optical system has an aperture diaphragm in a curved surface shape having an aperture part moving in an optical axis direction in association with a change in an aperture diameter. The aperture diaphragm is arranged to be a convex shape to an object side of the aperture diaphragm when the optical system arranged on the object side is arranged at a position having a negative refractive power, and the aperture diaphragm is arranged to be a convex shape to an image side when the optical system arranged on the object side of the aperture diaphragm is arranged at a position having a positive refractive power. |
