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US 12,724,253 B2Granted
Zoom lens, image pickup apparatus, and image pickup system
AssigneeCanon Kabushiki Kaisha
InventorNobuyuki Miyazawa
Life of this patent
Estimating the term…
Abstract
A zoom lens includes a plurality of lens units including, in order from an object side to an image side, a first lens unit having negative refractive power, a second lens unit having positive refractive power, a third lens unit having negative refractive power, and a fourth lens unit having positive refractive power. A distance between adjacent lens units changes during zooming. The second lens unit includes at least one negative lens. Predetermined inequalities are satisfied.
Claims15
A zoom lens comprising:
- a plurality of lens units including, in order from an object side to an image side, a first lens unit having negative refractive power, a second lens unit having positive refractive power, a third lens unit having negative refractive power, and a fourth lens unit having positive refractive power,
- wherein a distance between adjacent lens units changes during zooming,
- wherein the second lens unit includes at least one negative lens, and
- wherein the following inequalities are satisfied:
- 20
- <
- v
-
- 2
-
- n
- <
- 2
-
- 8
- 0.
- <
- f
-
- 2
- /
- f
-
- 4
- <
- 0
- .
- 4
-
- 0
- 12
- <
- Lw
- /
- fw
- <
- 55
- where v2n is a minimum value of an Abbe number of the negative lens, f2 is a focal length of the second lens unit, f4 is a focal length of the fourth lens unit, Lw is an overall optical length of the zoom lens at a wide-angle end, and fw is a focal length of the zoom lens at the wide-angle end.
35 more elements
An image pickup apparatus comprising:
- a zoom lens having a plurality of lens units;
- and
- an image sensor configured to receive an image formed by the zoom lens,
- wherein the plurality of lens units includes, in order from an object side to an image side, a first lens unit having negative refractive power, a second lens unit having positive refractive power, a third lens unit having negative refractive power, and a fourth lens unit having positive refractive power,
- wherein a distance between adjacent lens units changes during zooming,
- wherein the second lens unit includes at least one negative lens, and
- wherein the following inequalities are satisfied:
- 20
- <
- v
-
- 2
-
- n
- <
- 2
-
- 8
- 0.
- <
- f
-
- 2
- /
- f
-
- 4
- <
- 0
- .
- 4
-
- 0
- 12
- <
- Lw
- /
- fw
- <
- 5
-
- 5
- where v2n is a minimum value of an Abbe number of the negative lens, f2 is a focal length of the second lens unit, f4 is a focal length of the fourth lens unit, Lw is an overall optical length of the zoom lens at a wide-angle end, and fw is a focal length of the zoom lens at the wide-angle end.
40 more elements
An image pickup system comprising:
- a zoom lens having a plurality of lens units;
- and
- a control unit configured to control the zoom lens during zooming,
- wherein the plurality of lens units includes, in order from an object side to an image side, a first lens unit having negative refractive power, a second lens unit having positive refractive power, a third lens unit having negative refractive power, and a fourth lens unit having positive refractive power,
- wherein a distance between adjacent lens units changes during zooming,
- wherein the second lens unit includes at least one negative lens, and
- wherein the following inequalities are satisfied:
- 20
- <
- v
-
- 2
-
- n
- <
- 2
-
- 8
- 0.
- <
- f
-
- 2
- /
- f
-
- 4
- <
- 0
- .
- 4
-
- 0
- 12
- <
- Lw
- /
- fw
- <
- 5
-
- 5
- where v2n is a minimum value of an Abbe number of the negative lens, f2 is a focal length of the second lens unit, f4 is a focal length of the fourth lens unit, Lw is an overall optical length of the zoom lens at a wide-angle end, and fw is a focal length of the zoom lens at the wide-angle end.
40 more elements
Dependencies are inferred from the claim text.