Patent ID: 7864458
Filing Date: 2011-01-04
Classification: G02B

Abstract:
1. A lens barrel comprising: a support ring movable in an optical axis direction; a displaceable optical element supported by said support ring to be movable between a photographing position in which said displaceable optical element is positioned on said optical axis and a radially-displaced position in which said displaceable optical element is eccentrically displaced from said optical axis; and an advancing/retracting optical element supported by said support ring to be movable in said optical axis direction relative to said support ring, wherein, when said lens barrel is in a ready-to-photograph state, said displaceable optical element is held at said photographing position, and said displaceable optical element and said advancing/retracting optical element are aligned in said optical axis direction, and wherein, when said lens barrel moves from said ready-to-photograph state to an accommodated state in which no pictures can be taken, said displaceable optical element is held at said radially-displaced position, and said displaceable optical element and said advancing/retracting optical element are relatively moved closely to each other so as to at least partially coincide with each other in a direction orthogonal to the optical axis; a holding member which holds said advancing/retracting optical element and is supported by said support ring to be movable in said optical axis direction relative to said support ring; a movement limit device which determines a rear movement limit of said holding member in said optical axis direction; a biasing member which biases said holding member toward said rear movement limit thereof; and a rear limit member positioned behind said holding member in said optical axis direction, wherein, when said lens barrel is in said ready-to-photograph state, said holding member is held at said rear movement limit thereof and said advancing/retracting optical element is positioned behind said displaceable optical element, and wherein, when said lens barrel moves from said ready-to-photograph state to said accommodated state, said support ring is moved rearward in said optical axis direction and said holding member abuts against said rear limit member so that said holding member is prevented from moving rearward in said optical axis direction thereby, whereby a relative movement in said optical axis direction between said holding member and said support ring occurs against a biasing force of said biasing member.