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US 12,461,351 B2Granted
Zoom lens and image pickup apparatus
AssigneeCanon Kabushiki Kaisha
InventorAkihiko Yuki
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 that has a positive refractive power and does not move for zooming, a second lens unit that has a negative refractive power and moves in zooming, at least two lens units that move in zooming, and a final lens unit that has a positive refractive power, is disposed closest to the image side, and does not move for zooming. The first lens unit includes, in order from the object side to the image side, a first sub-lens unit that has a negative refractive power and does not move for focusing, a second sub-lens unit that has a negative refractive power and moves for focusing, and a third sub-lens unit having a positive refractive power. A distance between the second sub-lens unit and the third sub-lens unit changes for focusing.
Claims10
A zoom lens comprising in order from an object side to an image side:
- a first lens unit that has a positive refractive power and does not move for zooming;
- a second lens unit that has a negative refractive power and moves in zooming;
- a middle group that has at least two lens units that move in zooming;
- and
- a final lens unit that has a positive refractive power, is disposed closest to the image side, and does not move for zooming,
- wherein the zoom lens further comprises an aperture stop that is disposed between a surface closest to the image side of the second lens unit and a surface closest to the object side of the final lens unit, and moves in zooming,
- wherein each distance between adjacent lens groups changes in zooming,
- wherein the first lens unit includes, in order from the object side to the image side,
- a first sub-lens unit that has a negative refractive power and does not move for focusing;
- a second sub-lens unit that has a negative refractive power and moves for focusing;
- and
- a third sub-lens unit having a positive refractive power,
- wherein a distance between the second sub-lens unit and the third sub-lens unit changes for focusing,
- wherein the second sub-lens unit includes a negative lens, and
- wherein following inequalities are satisfied:
- 0.2
- ≤
- flb
- /
- fla
- ≤
- 3
- .
- 2
- 35
- ≤
- vlbn
- ≤
- 100
- 0.3
- ≤
- ❘
- "\[LeftBracketingBar]"
- f
-
- 2
- /
- fl
- ❘
- "\[RightBracketingBar]"
- ≤
- 0.8
- 0.08
- ≤
- (
- Lspt
- -
- Lspw
- )
- /
- Skw
- ≤
- 0
- .80
- where f1a is a focal length of the first sub-lens unit, f1b is a focal length of the second sub-lens unit, νbn is an Abbe number with respect to d-line of the negative lens in the second sub-lens unit, f1 is a focal length of the first lens unit, and f2 is a focal length of the second lens unit, Lspw is a distance on an optical axis from a surface closest to the object side of the first lens unit to the aperture stop at a wide-angle end, Lspt is a distance on the optical axis from the surface closest to the object side of the first lens unit to the aperture stop at a telephoto end, and Skw is a distance on the optical axis from a surface closest to the image side of the final lens unit to an image plane.
52 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 that has a positive refractive power and does not move for zooming;
- a second lens unit that has a negative refractive power and moves in zooming;
- a middle group that has at least two lens units that move in zooming;
- and
- a final lens unit that has a positive refractive power, is disposed closest to the image side, and does not move for zooming,
- wherein the zoom lens further comprises an aperture stop that is disposed between a surface closest to the image side of the second lens unit and a surface closest to the object side of the final lens unit, and moves in zooming,
- wherein each distance between adjacent lens groups changes in zooming,
- wherein the first lens unit includes, in order from the object side to the image side,
- a first sub-lens unit that has a negative refractive power and does not move for focusing;
- a second sub-lens unit that has a negative refractive power and moves for focusing;
- and
- a third sub-lens unit having a positive refractive power,
- wherein a distance between the second sub-lens unit and the third sub-lens unit changes for focusing,
- wherein the second sub-lens unit includes a negative lens, and
- wherein following inequalities are satisfied:
- 0.2
- ≤
- flb
- /
- fla
- ≤
- 3
- .
- 2
- 35
- ≤
- vlbn
- ≤
- 100
- 0.3
- ≤
- ❘
- "\[LeftBracketingBar]"
- f
-
- 2
- /
- fl
- ❘
- "\[RightBracketingBar]"
- ≤
- 0.8
- 0.08
- ≤
- (
- Lspt
- -
- Lspw
- )
- /
- Skw
- ≤
- 0
- .80
- where f1a is a focal length of the first sub-lens unit, f1b is a focal length of the second sub-lens unit, νbn is an Abbe number with respect to d-line of the negative lens in the second sub-lens unit, f1 is a focal length of the first lens unit, and f2 is a focal length of the second lens unit, Lspw is a distance on an optical axis from a surface closest to the object side of the first lens unit to the aperture stop at a wide-angle end, Lspt is a distance on the optical axis from the surface closest to the object side of the first lens unit to the aperture stop at a telephoto end, and Skw is a distance on the optical axis from a surface closest to the image side of the final lens unit to an image plane.
56 more elements
Dependencies are inferred from the claim text.