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US 4,733,278 AGranted
Apparatus for forming image on copying machine at variable zoom ratio
AssigneeAsahi Kogaku Kogyo Kabushiki Kaisha
InventorIkuo Negoro
Life of this patent
Estimating the term…
Abstract
A three-group lens barrel for zooming in a photo-copier in which the barrel is movable and fixes a middle lens group. The front and rear lens group are slidable in the barrel. The front and rear lens groups are connected to ends of two link levers. The link levers are swung together or apart by a common pin connection to a swing lever which has at one end a cam follower following a cam groove in the photo-copier. The common pin may be eccentric to finely adjust the lens separation.
Claims6
An apparatus for forming an image at a variable zoom ratio, comprising:
- a lens barrel displaceable along an optical axis;
- a first lens group;
- a second lens group mounted behind said first lens group along said optical axis and fixed to said barrel;
- a third lens group mounted behind said second lens group along said optical axis;
- a first frame slidable along said optical axis in said barrel and supporting said first lens group
- a second frame slidable along said optical axis in said barrel and supporting said third lens group;
- a swing lever;
- means for swinging said swing lever in response to a displacement of said lens barrel along said optical axis;
- a pair of link levers coupled to said swing lever and said first and second frames;
- and
- a rotatable eccentric pin carried by said swing lever and coaxially supporting both of said link levers at first ends thereof, whereby an amount of said separation of said first and second frames is adjustable by a rotation of said eccentric pin, whereby a separation of said first and second frames is changed in response to said displacement of said lens barrel along said optical axis.
8 more elements
Dependencies are inferred from the claim text.