Patent ID: 7839579
Filing Date: 2010-11-23
Classification: G02B,G03B

Abstract:
1. A lens barrel, comprising: a plurality of lenses; a plurality of lens frames each of which holds respectively at least one lens of the plurality of lenses; a driving section which moves the lens frames in a direction of an optical axis; a fixed member which holds the driving section; a rotating member included in the driving section and which rotates to move the lens frames to predetermined positions, the rotating member being fitted in an inner circumferential surface of the fixed member and being rotated relative to the fixed member to be movable in the direction of the optical axis, wherein the rotating member moves relative to the fixed member in the direction of the optical axis while rotating relative to the fixed member from a non-photographing state to a photographing state including an initial photographing state, and does not move relative to the fixed member in the direction of the optical axis while rotating relative to the fixed member in the photographing state; cam followers each provided on the lens frames; cams each provided on an inner circumferential surface of the rotating member and each having a cam surface, the cams each being engaged with the corresponding cam followers and each forming a cam locus; and an elastic member provided in the driving section, and which always biases one of the lens frames located closest to an object side as a first lens frame toward the corresponding cam surface on the object side, wherein, in the initial photographing state, the cam locus on the object side of one of the cams engaged with one of the cam followers corresponding to the first lens frame as a first cam forms a part following along a direction perpendicular to the optical axis, and the cam locus on an image plane side of the first cam facing the cam locus on the object side has an angle to the direction perpendicular to the optical axis.