Patent ID: 6873472
Filing Date: 2005-03-29
Classification: G02B

Abstract:
1. A zoom lens barrel comprising: a linear guide ring which is positioned about an optical axis, said linear guide ring including at least one linear guide slot extending parallel to said optical axis; a cam ring which is coaxially positioned around said linear guide ring, said cam ring including at least one cam groove; and a movable lens frame which supports a lens group and includes at least one cam follower, said cam follower passes through said linear guide slot to be engaged in said cam groove so that a rotation of one of said cam ring and said linear guide ring relative to the other causes said movable lens frame to move along said optical axis via engagement of said cam follower with said linear guide slot and said cam groove; wherein said cam ring is provided with a large ring portion, a small ring portion having a smaller diameter than said large ring portion, and a radial flange portion which is positioned between said large ring portion and said small ring portion to connect said large ring portion with said small ring portion; and wherein said cam groove is formed on both said small ring portion and said radial flange portion so that one end of the cam groove constitutes an open end at said radial flange portion, whereby said cam follower can be inserted into said cam groove through said open end.