Patent ID: 7549810

Claim:
A light amount adjusting apparatus used in an image pickup apparatus, the light amount adjusting apparatus comprising: a base plate having a first opening; a blade member movable within a range including a position where the blade member overlaps the first opening in an optical axis direction, for restricting an amount of a light passing through the first opening by overlapping the first opening; a plate member having a second opening at a position overlapping the first opening in the optical axis direction wherein the plate member is disposed adjacent to the blade member and has a first cut portion at a position where the plate member overlaps the blade member in the optical axis direction in a state in which the blade member is at a predetermined position; and a cover member which is provided to sandwich the blade member in the optical axis direction with the plate member and in which a second cut portion is formed so that at least both whole portion of the second opening and a part of the first cut portion locate within the second cut portion; wherein the second opening is positioned at a position where the second opening overlaps the first opening regardless of a position of the blade member.