Patent ID: 6995927
Filing Date: 2006-02-07
Classification: G02B

Abstract:
1. An adjustment mechanism for an optical lens system comprising a plurality of lens groups installed in a lens barrel for adjusting an axial position of one of the lens groups relative to another lens group, said adjustment mechanism: an annular lens holding frame for fixedly holding the one lens group therein; a cylinder forming part of the lens barrel for holding said annular lens holding frame so as to allow said annular lens holding frame to shift in a direction of an optical axis of the optical lens system and to rotate about said optical axis; and position adjustment means provided between said annular lens holding frame and said cylinder for gradually varying an axial position between said annular lens holding frame and said cylinder; wherein said position adjustment means comprises an axial position selective collar with a flight of stairs formed thereon that extends circumferentially within said cylinder and gradually varies stepwise in said direction of said optical axis and locating means formed on an outer periphery of said annular lens holding frame for defining a reference face against which said stairs are selectively abutted to locate said annular lens holding frame in a selected axial position relative to said cylinder when said annular lens holding frame is rotated.