Patent ID: 7936524

Claim:
A lens barrel comprising: a barrier unit provided on the front side of a photographic lens and configured to gate an aperture of the photographic lens; and a lens holding member capable of being attached to said barrier unit and configured to hold the photographic lens; wherein said barrier unit includes: a cover member having an aperture with the optical axis as a center; a barrier blade attached to the cover member such that the aperture can be opened or closed; a barrier blade driving member which is rotatably held with the cover member and has a rotation transmission protrusion extending to the side of an object in the direction of the optical axis; and a rotation regulating member formed on the lens holding member and configured to regulate the rotation of said barrier unit when said barrier unit is assembled with the lens holding member while being rotated; and wherein the direction in which said barrier unit is rotated when said barrier unit is assembled with the lens holding member coincides with the direction in which the barrier blade driving member is rotated when the barrier blade is closed from the open state.