Zoom lens and image pickup apparatus
AssigneeCanon Kabushiki Kaisha
InventorMakoto NAKAHARA
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 with negative refractive power, an intermediate group with negative refractive power including at least one lens unit, and a rear group with positive refractive power including a plurality of lens units. Each distance between adjacent lens units changes. The first unit does not move during zooming. An air gap between the intermediate group and the rear group is maximized at a wide-angle end. The intermediate group includes a plurality of negative lenses. The rear group includes a focus unit that moves during focusing. A predetermined inequality is satisfied.
Claims23
A zoom lens comprising, in order from an object side to an image side:
- a first lens unit with negative refractive power;
- an intermediate group with negative refractive power including at least one lens unit;
- and
- a rear group with positive refractive power including a plurality of lens units,
- wherein each distance between adjacent lens units changes,
- wherein the first lens unit does not move during zooming,
- wherein an air gap between the intermediate group and the rear group is maximized at a wide-angle end,
- wherein the intermediate group includes a plurality of negative lenses,
- wherein the rear group includes a focus unit that moves during focusing, and
- wherein the following inequality is satisfied:
- -
- 5.
- ≤
- DLNw
- /
- fL
-
- 1
- ≤
- -
- 0
- .
- 7
- where fL1 is a focal length of the first lens unit, and DLNw is a distance on an optical axis from a lens surface of the intermediate group closest to an object at the wide-angle end to a lens surface of the intermediate group closest to an image plane at the wide-angle end.
An image pickup apparatus comprising:
- a zoom lens;
- and
- an image sensor for capturing an image of an object through the zoom lens,
- wherein the zoom lens includes, in order from an object side to an image side:
- a first lens unit with negative refractive power;
- an intermediate group with negative refractive power including at least one lens unit;
- and
- a rear group with positive refractive power including a plurality of lens units,
- wherein each distance between adjacent lens units changes,
- wherein the first lens unit does not move during zooming,
- wherein an air gap between the intermediate group and the rear group is maximized at a wide-angle end,
- wherein the intermediate group includes a plurality of negative lenses,
- wherein the rear group includes a focus unit that moves during focusing, and
- wherein the following inequality is satisfied:
- -
- 5.
- ≤
- DLNw
- /
- fL
-
- 1
- ≤
- -
- 0
- .
- 7
- where fL1 is a focal length of the first lens unit, and DLNw is a distance on an optical axis from a lens surface of the intermediate group closest to an object at the wide-angle end to a lens surface of the intermediate group closest to an image plane at the wide-angle end.
Dependencies are inferred from the claim text.