Patent ID: 6252628
Filing Date: 2001-06-26
Classification: G02B

Abstract:
A zoom finder comprising:first and second movable lenses composing a variable magnification optical system of said zoom finder, each of said first and second movable lenses being provided with a guide hole, an engaging part and a cam follower;a guide shaft for supporting said first and second movable lenses movably along an optical axis of said variable magnification optical system, said guide shaft being arranged parallel to the optical axis and being inserted into said guide holes of said first and second movable lenses;a rotation preventive member for preventing said first and second movable lenses from rotating around said guide shaft by engaging with said engaging parts of said first and second movable lenses, said rotation preventive member being arranged parallel to the optical axis;a finder cam for moving said first and second movable lenses along the optical axis by moving first and second cam faces which are provided at said finder cam and are respectively in contact with said cam followers of said first and second movable lenses;a pressing member for pressing said cam followers of said first and second movable lenses against said first and second cam faces of said finder cam; andwherein at least one of said first and second cam faces of said finder cam inclines, over the whole area for use, to one side with respect to a direction in which a pressing force of said pressing member is applied to the cam follower of at least one of said first and second movable lenses which is in contact with said at least one of said first and second cam faces, so that the engaging part of said at least one of said first and second movable lenses can always be in contact with said rotation preventive member by operation of a component of the pressing force of said pressing member in a direction of a tangent line of said at least one of said first and second cam faces at a point where said at least one of said first and second cam faces is in contact with said cam follower of said at least one of said first and second movable lenses.