Zoom lens and image pickup apparatus
AssigneeCanon Kabushiki Kaisha
InventorTakahiro Hatada
Life of this patent
Estimating the term…
Abstract
The zoom lens according to the present invention consists of, in order from an object side to an image side, a positive first lens unit, a negative second lens unit, and a positive rear unit including at least four lens units. The second lens unit moves toward the object side during zooming from a wide angle end to a telephoto end, and an interval between each pair of adjacent lens units is changed during zooming. The rear unit includes a positive lens unit LP, which is arranged closest to the image side. Focal lengths of the zoom lens at the wide angle end and at the telephoto end, focal lengths of the first lens unit and the second lens unit, and a distance from the lens surface of the lens unit LP on the image side to an image plane at the telephoto end are each set appropriately.
Claims12
A zoom lens having a configuration that an interval between each pair of adjacent lens units is changed during zooming, the zoom lens comprising, in order from an object side to an image side:
- a first lens unit having a positive refractive power;
- a second lens unit having a negative refractive power;
- and
- a rear unit including at least four lens units and having a positive refractive power as a whole,
- wherein the second lens unit is configured to move toward the object side monotonically during zooming from a wide angle end to a telephoto end,
- wherein the rear unit includes a lens unit LP having a positive refractive power, which is arranged closest to the image side of the zoom lens, and
- wherein the following conditional expressions are satisfied:
- 0.7<f1/ft<1.2;
- 0.7<|f2/fw|<1.0;
- 0.1<dLP/ft<0.4;
- and
- 0.3<fLP/ft<1.0,
- where fw represents a focal length of the zoom lens at the wide angle end, ft represents a focal length of the zoom lens at the telephoto end, f1 represents a focal length of the first lens unit, f2 represents a focal length of the second lens unit, dLP represents a distance from a lens surface of the lens unit LP on the image side to an image plane at the telephoto end, and fLP represents a focal length of a whole of the lens unit LP.
An image pickup apparatus comprising:
- a zoom lens;
- and
- an image pickup element configured to receive light of an image formed by the zoom lens,
- wherein the zoom lens is a zoom lens having a configuration that an interval between each pair of adjacent lens units is changed during zooming, the zoom lens including, in order from an object side to an image side:
- a first lens unit having a positive refractive power;
- a second lens unit having a negative refractive power;
- and
- a rear unit including at least four lens units and having a positive refractive power as a whole,
- wherein the second lens unit is configured to move toward the object side monotonically during zooming from a wide angle end to a telephoto end,
- wherein the rear unit includes a lens unit LP having a positive refractive power, which is arranged closest to the image side of the zoom lens, and
- wherein the following conditional expressions are satisfied:
- 0.7<f1/ft<1.2;
- 0.7<|f2/fw|<1.0;
- 0.1<dLP/ft<0.4;
- and
- 0.3<fLP/ft<1.0,
- where fw represents a focal length of the zoom lens at the wide angle end, ft represents a focal length of the zoom lens at the telephoto end, f1 represents a focal length of the first lens unit, f2 represents a focal length of the second lens unit, dLP represents a distance from a lens surface of the lens unit LP on the image side to an image plane at the telephoto end, and fLP represents a focal length of a whole of the lens unit LP.
Dependencies are inferred from the claim text.