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US 11,860,347 B2Granted
Zoom lens and image pickup apparatus
AssigneeCanon Kabushiki Kaisha
InventorKazufumi Goto
Life of this patent
Estimating the term…
Abstract
A zoom lens includes, in order from an object side to an image side, a first lens unit configured not to move for zooming, a plurality of zooming lens units configured to move in zooming, a front relay lens unit configured not to move for zooming, an extender lens unit insertable into and removable from an optical path for changing a focal length range of the zoom lens, and a rear relay lens unit configured not to move for zooming, and satisfies specific conditional expressions.
Claims14
A zoom lens comprising in order from an object side to an image side:
- a first lens unit configured not to move for zooming;
- a plurality of zooming lens units configured to move in zooming;
- a front relay lens unit configured not to move for zooming;
- an extender lens unit insertable into and removable from an optical path for changing a focal length range of the zoom lens;
- and
- a rear relay lens unit configured not to move for zooming,
- wherein a part of the first lens unit moves at focusing,
- a combined focal length of the front relay lens unit, the extender lens unit and the rear relay lens unit is a positive value,
- wherein following conditional expressions are satisfied:
- 1.00<(Def/Der)/βe+(1−few/feF)<1.75,
- 0.50<(le/Der)/βe<1.22, and
- 0.10<few/feF<1.00,
- where few is a focal length at a wide-angle end and in a state where the extender lens unit is inserted, feF is a combined focal length from the first lens unit to the front relay lens unit, Def is an effective diameter of a lens surface in a lens included in the extender lens unit and closest to the object side, Der is an effective diameter of a lens surface in a lens included in the extender lens unit and closest to the image side, βe is a lateral magnification of the extender lens unit, and le is a distance on an optical axis from a surface included in the extender lens unit and closest to the object side to a surface included in the extender lens unit and closest to the image side.
10 more elements
An image pickup apparatus comprising:
- a zoom lens;
- and
- an image pickup element configured to pick up an image formed by the zoom lens,
- wherein the zoom lens includes in order from an object side to an image side:
- a first lens unit configured not to move for zooming,
- a plurality of zooming lens units configured to move in zooming,
- a front relay lens unit configured not to move for zooming,
- an extender lens unit insertable into and removable from an optical path for changing a focal length range of the zoom lens, and
- a rear relay lens unit configured not to move for zooming,
- wherein a part of the first lens unit moves at focusing,
- a combined focal length of the front relay lens unit, the extender lens unit and the rear relay lens unit is a positive value,
- wherein following conditional expressions are satisfied:
- 1.00 <(Def/Der)/βe+(1−few/feF)<1.75,
- 0.50<(le/Der)/βe<1.22, and
- 0.10<few/feF<1.00,
- where few is a focal length at a wide-angle end and in a state where the extender lens unit is inserted, feF is a combined focal length from the first lens unit to the front relay lens unit, Def is an effective diameter of a lens surface in a lens included in the extender lens unit and closest to the object side, Der is an effective diameter of a lens surface in a lens included in the extender lens unit and closest to the image side, βe is a lateral magnification of the extender lens unit, and le is a distance on an optical axis from a surface included in the extender lens unit and closest to the object side to a surface included in the extender lens unit and closest to the image side.
13 more elements
Dependencies are inferred from the claim text.