Patent ID: 6837628

Claim:
A barrier opening and closing mechanism, comprising: a refractive optical system having a plurality of lens elements which are disposed so as to turn light substantially at a right angle; a lens barrel for holding the refractive optical system; a rotary cam ring disposed concentrically with the lens barrel, having a first cam groove, and for rotating on an optical axis of subject light having been turned; a lens driving mechanism for driving, in a direction of the optical axis of subject light having been turned, at least one lens element included in the refractive optical system engaged with the first cam groove; and a barrier member for protecting a most subject side lens element of the refractive optical system; and wherein the rotary cam ring has, in a predetermined angle range on an outer surface thereof, a second cam groove including a region extending obliquely to the optical axis, a driving member is provided that has a cam follower engaged with the second cam groove and is driven in a direction substantially parallel to the optical axis, and the barrier is opened and closed by moving in response to a movement of the driving member in the predetermined angle range.