Stop device for zoom lens
AssigneeAsahi Kogaku Kogyo Kabushiki Kaisha
InventorShinsuke Kohmoto
Life of this patent
Estimating the term…
Abstract
A stop device for a zoom lens includes an aperture-stop provided between a front lens group and a rear lens group. The front lens group, the rear lens group, and the aperture-stop are moved relative to each other by a motor, to carry out a zooming operation. The motor is provided behind the front lens group and the aperture-stop, and the aperture-stop is positioned closed to a front end of the motor when the aperture-stop is at its rearmost position.
Claims14
A stop device for a zoom lens having front and rear ends and including at least two lens groups and a motor having at least one end, said lens groups being movable relative to each other along the optical axis by said motor, one of said lens groups being located in front of the other of said lens groups along the optical axis, said stop device comprising:
- an aperture-stop disposed between one of said lens groups and said other lens group, and movable along the optical axis between frontmost and rearmost positions, relative to said other lens group, said aperture-stop being positioned adjacent to said one end of said motor when said aperture-stop is at said rearmost position.
A stop device for a zoom lens having front and rear ends and housing a motor, having at least one end, for moving one lens group which is disposed in front of an other lens group, said stop device comprising:
- an aperture-stop disposed in front of said other lens group and movable relative to said other lens group between frontmost and rearmost positions, said aperture-stop being positioned adjacent said one end of said motor when said aperture-stop is at said rearmost position.
A zoom lens having front and rear ends, and comprising:
- a front lens group;
- a rear lens group;
- a motor having at least one end, for moving at least one of said front lens group and said rear lens group along the optical axis to thereby carry out a zooming operation, said motor being provided behind said front lens group;
- and
- an aperture-stop provided between said front lens group and said rear lens group, said-aperture stop being moved by said motor along the optical axis, and positioned adjacent said motor when said aperture-stop is positioned at a point farthest from said front lens group.
A zoom lens including at least two lens groups within a lens barrel, one of said lens groups being a rear lens group, said zoom lens comprising:
- a motor for causing said lens groups to be movable relative to each other along the optical axis within a predetermined range, said motor being located within said lens barrel;
- and
- an aperture-stop disposed in front of said rear lens group, said aperture-stop being positioned adjacent to an end of said motor when said aperture-stop is at the rearmost position of said range.
Dependencies are inferred from the claim text.