Zoom lens and image pickup apparatus having the same
AssigneeCanon Kabushiki Kaisha
InventorTakahiro Hatada
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 a negative refractive power, and a rear unit having a positive refractive power as a whole. A distance between the first lens unit and the rear unit is changed during zooming. The rear unit includes a subunit that is moved in a direction having a component of a direction orthogonal to an optical axis during image stabilization. The first lens unit includes, in order from the object side to the image side, three or more negative lenses. A predetermined condition is satisfied.
Claims20
A zoom lens comprising, in order from an object side to an image side, a first lens unit having a negative refractive power, and a rear group having a positive refractive power as a whole, including at least one lens unit,
- wherein a distance between the first lens unit and the rear group is changed during zooming,
- wherein the rear group includes a subunit that is moved in a direction having a component of a direction orthogonal to an optical axis during image stabilization,
- wherein the first lens unit includes, in order from the object side to the image side, three or more negative lenses,
- wherein a lens A which is disposed closest to the image side in the rear group includes a positive refractive power,
- wherein a lens surface of the lens A on the object side is concave toward the object side,
- wherein a lens surface of the lens A on the image side is concave toward the object side, and
- wherein the following inequalities are satisfied:
- −20<Dist_w←8;
- −0.4<fl/fLN<0.7;
- −2.2<fl/skw≤−1.16;
- and
- −1.5<Ymax_w/fl←0.5;
- where Dist_w is a distortion amount at a maximum image height in an in-focus state at infinity at a wide-angle end, fl is a focal length of the first lens unit, fLN is a focal length of a final lens unit closest to an image plane, skw is a backfocus of the zoom lens at the wide-angle end, and Ymax_w is a maximum image height at the wide-angle end.
An 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 a negative refractive power, and a rear group having a positive refractive power as a whole, including at least one lens unit,
- wherein a distance between the first lens unit and the rear group is changed during zooming,
- wherein the rear group includes a subunit that is moved in a direction having a component of a direction orthogonal to an optical axis during image stabilization,
- wherein the first lens unit includes, in order from the object side to the image side, three or more negative lenses,
- wherein a lens A which is disposed closest to the image side in the rear group includes a positive refractive power,
- wherein a lens surface of the lens A on the object side is concave toward the object side,
- wherein a lens surface of the lens A on the image side is concave toward the object side, and
- wherein the following inequalities are satisfied:
- −20<Dist_w←8;
- −0.4<fl/fLN<0.7;
- −2.2<fl/skw≤−1.16;
- and
- −1.5<Ymax_w/fl←0.5;
- where Dist_w is a distortion amount at a maximum image height in an in-focus state at infinity at a wide-angle end, fl is a focal length of the first lens unit, fLN is a focal length of a final lens unit closest to an image plane, skw is a backfocus of the zoom lens at the wide-angle end, and Ymax_w is a maximum image height at the wide-angle end.
Dependencies are inferred from the claim text.