US 12,613,398 B2Granted

Zoom lens, image pickup apparatus, and image pickup system

AssigneeCanon Kabushiki Kaisha

InventorNaotoshi Ogawa

Life of this patent

Estimating the term…

Loading patent…

Abstract

A zoom lens includes a plurality of lens units, which consist of, in order from an object side to an image side, a first lens unit having positive refractive power, an intermediate group including a plurality of lens units, and a rear lens unit. A distance between adjacent lens units changes during zooming from a wide-angle end to a telephoto end. The first lens unit is fixed relative to an image plane for zooming from the wide-angle end to the telephoto end. The first lens unit consists of a plurality of subunits in which a distance between adjacent subunits changes during focusing, and the plurality of subunits include, in order from the object side to the image side, a first subunit that does not move for focusing, a second subunit having positive refractive power that moves for focusing, and a third subunit having negative refractive power. A predetermined inequality is satisfied.

Claims18

Dependent claims

A zoom lens comprising a plurality of lens units, the plurality of lens units consisting of, in order from an object side to an image side, a first lens unit having positive refractive power, an intermediate group including a plurality of lens units, and a rear lens unit,

wherein a distance between adjacent lens units changes during zooming from a wide-angle end to a telephoto end,
wherein the first lens unit is fixed relative to an image plane for zooming from the wide-angle end to the telephoto end,
wherein the first lens unit consists of a plurality of subunits in which a distance between adjacent subunits changes during focusing, and the plurality of subunits include, in order from the object side to the image side, a first subunit that does not move for focusing, a second subunit having positive refractive power that moves for focusing, and a third subunit having negative refractive power, and
wherein the following inequalities are satisfied:
0
.
1
⁢
0
<
(
f
⁢
1
+
Ok
⁢
1
)
/
f
⁢
1
<
0.8
1.
<
f
⁢
1
/
f
⁢
1
⁢
b
<
2
.
0
⁢
0
where f1 is a focal length of the first lens unit in an in-focus state at infinity, Ok1 is a distance on an optical axis from a lens surface closest to an object of the first lens unit to an image-side principal point of the first lens unit in the in-focus state at infinity, and f1b is a focal length of the second subunit.

40 more elements

An image pickup system comprising:

a zoom lens;
and
a control unit configured to control the zoom lens during zooming,
wherein the zoom lens includes a plurality of lens unit, the plurality of lens units consisting of, in order from an object side to an image side, a first lens unit having positive refractive power, an intermediate group including a plurality of lens units, and a rear lens unit,
wherein a distance between adjacent lens units changes during zooming from a wide-angle end to a telephoto end,
wherein the first lens unit is fixed relative to an image plane for zooming from the wide-angle end to the telephoto end,
wherein the first lens unit consists of a plurality of subunits in which a distance between adjacent subunits changes during focusing, and the plurality of subunits include, in order from the object side to the image side, a first subunit that does not move for focusing, a second subunit having positive refractive power that moves for focusing, and a third subunit having negative refractive power, and
wherein the following inequalities are satisfied:
0
.
1
⁢
0
<
(
f
⁢
1
+
Ok
⁢
1
)
/
f
⁢
1
<
0.8
1.
<
f
⁢
1
/
f
⁢
1
⁢
b
<
2
.
0
⁢
0
where f1 is a focal length of the first lens unit in an in-focus state at infinity, Ok1 is a distance on an optical axis from a lens surface closest to an object of the first lens unit to an image-side principal point of the first lens unit in the in-focus state at infinity, and f1b is a focal length of the second subunit.

44 more elements

Dependencies are inferred from the claim text.