Patent ID: 6851871

Claim:
A lens apparatus comprising: a lens unit which forms an optical image; a barrier member which can be moved open and close; a driving member that drives the barrier member into an open position by rotating in one direction around an optical axis, and drives the barrier member into a close position by rotating in another direction around the optical axis; an energizing member which energizes the driving member in the one direction; and a barrel which is constructed around the optical axis, wherein the driving member and the barrel move in the direction of the optical axis relatively; and wherein the barrel has a first guide portion that rotates the driving member in the one direction, and a second guide portion that rotates the driving member in the other direction while resisting an energizing force of the energizing member, according to a relative position change with the driving member; and wherein a length of the first guide portion in the direction of the optical axis is shorter than that of the second guide portion; and wherein the driving member drives the barrier member into the open position by rotating in the one direction by the first guide portion when the driving member can not rotate into a position corresponding to the open position of the barrier member by the energizing force of the energizing member.