Zoom lens and image pickup apparatus
AssigneeCanon Kabushiki Kaisha
InventorKazufumi Goto
Life of this patent
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Abstract
A zoom lens includes, in order from an object side to an image side, a first lens unit having a positive refractive power, a plurality of zooming lens units configured to move along an optical axis in zooming and including a lens unit having a negative refractive power, and a final lens unit having a positive refractive power. A distance between each pair of adjacent lens units changes in zooming. The first lens unit includes, in order from the object side to the image side, a first subunit having a negative refractive power, a second subunit having a negative refractive power, and at least one subsequent subunit, a distance between each pair of adjacent subunits changing for focusing. The second subunit is configured to move along the optical axis for focusing. A predetermined condition is satisfied.
Claims15
A zoom lens comprising, in order from an object side to an image side:
- a first lens unit having a positive refractive power;
- a plurality of zooming lens units configured to move along an optical axis in zooming and including a lens unit having a negative refractive power;
- and
- a final lens unit having a positive refractive power,
- wherein a distance between each pair of adjacent lens units changes in zooming,
- wherein the zoom lens comprises a diaphragm configured to move along the optical axis in zooming,
- wherein the first lens unit includes, in order from the object side to the image side, a first subunit having a negative refractive power, a second subunit having a negative refractive power, and at least one subsequent subunit, a distance between each pair of adjacent subunits changing for focusing,
- wherein the second subunit is configured to move along the optical axis for focusing, and
- wherein the following inequality is satisfied:
- 0.20<f1R/f1<1.10;
- and
- −0.60<β12/β1R<0.00
- where f1R is a focal length of the at least one subsequent subunit in an in-focus state at infinity, f1 is a focal length of the first lens unit in the in-focus state at infinity, β12 is a lateral magnification of the second subunit in the in-focus state at infinity, and β1R is a lateral magnification of the at least one subsequent subunit in the in-focus state at infinity.
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 having a positive refractive power;
- a plurality of zooming lens units configured to move along an optical axis in zooming and including a lens unit having a negative refractive power;
- and
- a final lens unit having a positive refractive power,
- wherein a distance between each pair of adjacent lens units changes in zooming,
- wherein the zoom lens comprises a diaphragm configured to move along the optical axis in zooming,
- wherein the first lens unit includes, in order from the object side to the image side, a first subunit having a negative refractive power, a second subunit having a negative refractive power, and at least one subsequent subunit, a distance between each pair of adjacent subunits changing for focusing,
- wherein the second subunit is configured to move along the optical axis for focusing, and
- wherein the following inequality is satisfied:
- 0.20<f1R/f1<1.10;
- and
- −0.60<β12/β1R<0.00
- where f1R is a focal length of the at least one subsequent subunit in an in-focus state at infinity, f1 is a focal length of the first lens unit in the in-focus state at infinity, β12 is a lateral magnification of the second subunit in the in-focus state at infinity, and β1R is a lateral magnification of the at least one subsequent subunit in the in-focus state at infinity.
Dependencies are inferred from the claim text.