Zoom lens, image pickup apparatus, and imaging system
AssigneeCanon Kabushiki Kaisha
InventorMasato KATAYOSE
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 having positive refractive power, a second lens unit having negative refractive power, and a subsequent unit including a plurality of lens units. A distance between adjacent lens units changes during zooming. The first lens unit does not move and the second lens unit moves during zooming. The first lens unit consists of, in order from the object side to the image side, a first subunit and a second subunit. The first subunit consists of two positive lenses. The second subunit consists of a single positive lens and a single negative lens. A predetermined condition is satisfied.
Claims18
-17. (canceled)
A zoom lens comprising, in order from an object side to an image side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, and a subsequent unit including a plurality of lens units,
- wherein a distance between adjacent lens units changes during zooming,
- wherein the first lens unit does not move and the second lens unit moves during zooming,
- wherein the first lens unit consists of, in order from the object side to the image side, a first subunit and a second subunit,
- wherein the first subunit consists of two positive lenses,
- wherein the second subunit consists of a single positive lens and a single negative lens,
- wherein the subsequent unit includes a lens A disposed closest to the image side,
- wherein a lens surface of the lens A on the image side is convex toward the image side, and
- wherein the following inequalities are satisfied:
- -
- 0
- .
- 4
-
- 5
- <
- f
-
- 1
-
- a
- /
- f
-
- 1
-
- b
- <
- -
- 0
- .10
- -
- 5.5
-
- 0
- <
- f
-
- 1
- /
- f
-
- 2
- <
- -
- 3
- .
- 0
-
- 0
- where f1a is a focal length of the first subunit, f1b is a focal length of the second subunit, f1 is a focal length of the first lens unit, and f2 is a focal length of the second lens unit.
The image pickup apparatus comprising:
- a zoom lens;
- and
- an image sensor configured to receive 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 having positive refractive power, a second lens unit having negative refractive power, and a subsequent unit including a plurality of lens units,
- wherein a distance between adjacent lens units changes during zooming,
- wherein the first lens unit does not move and the second lens unit moves during zooming,
- wherein the first lens unit consists of, in order from the object side to the image side, a first subunit and a second subunit,
- wherein the first subunit consists of two positive lenses,
- wherein the second subunit consists of a single positive lens and a single negative lens,
- wherein the subsequent unit includes a lens A disposed closest to the image side,
- wherein a lens surface of the lens A on the image side is convex toward the image side, and
- wherein the following inequalities are satisfied:
- -
- 0
- .
- 4
-
- 5
- <
- f
-
- 1
-
- a
- /
- f
-
- 1
-
- b
- <
- -
- 0
- .10
- -
- 5.5
- <
- f
-
- 1
- /
- f
-
- 2
- <
- -
- 3
- .
- 0
-
- 0
- where f1a is a focal length of the first subunit, f1b is a focal length of the second subunit, f1 is a focal length of the first lens unit, and f2 is a focal length of the second lens unit.
An imaging system comprising:
- a zoom lens;
- and
- a control unit configured to control the zoom lens during zooming, wherein the zoom lens includes, in order from an object side to an image side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, and a subsequent unit including a plurality of lens units,
- wherein a distance between adjacent lens units changes during zooming,
- wherein the first lens unit does not move and the second lens unit moves during zooming,
- wherein the first lens unit consists of, in order from the object side to the image side, a first subunit and a second subunit,
- wherein the first subunit consists of two positive lenses,
- wherein the second subunit consists of a single positive lens and a single negative lens,
- wherein the subsequent unit includes a lens A disposed closest to the image side,
- wherein a lens surface of the lens A on the image side is convex toward the image side, and
- wherein the following inequalities are satisfied:
- -
- 0.4
-
- 5
- <
- f
-
- 1
-
- a
- /
- f
-
- 1
-
- b
- <
- -
- 0
- .
- 1
-
- 0
- -
- 5.5
- <
- f
-
- 1
- /
- f
-
- 2
- <
- -
- 3
- .
- 0
-
- 0
- where f1a is a focal length of the first subunit, f1b is a focal length of the second subunit, f1 is a focal length of the first lens unit, and f2 is a focal length of the second lens unit.
Dependencies are inferred from the claim text.