Zoom lens, optical apparatus, and method for manufacturing zoom lens
AssigneeNikon Corporation
InventorTakeshi Umeda
Life of this patent
Estimating the term…
Abstract
A zoom lens includes, in order from an object along an optical axis: a first lens group having a negative refractive power; a second lens group having a positive refractive power; a third lens group having a negative refractive power; a fourth lens group; and a fifth lens group. When the zoom lens performs varying magnification, the distance between the first and second lens groups changes, the distance between the second and third lens groups changes, the distance between the third and fourth lens groups changes, the distance between the fourth and fifth lens groups changes, the second and fourth lens groups move along the same trajectory along the optical axis, and at least the third lens group moves along the optical axis.
Claims17
A zoom lens comprising, in order from an object along an optical axis:
- a first lens group having a negative refractive power;
- a second lens group having a positive refractive power;
- a third lens group having a negative refractive power;
- a fourth lens group;
- and
- a fifth lens group, wherein
- when the zoom lens performs varying magnification, the distance between the first and second lens groups changes, the distance between the second and third lens groups changes, the distance between the third and fourth lens groups changes, the distance between the fourth and fifth lens groups changes, the second and fourth lens groups move along the same trajectory along the optical axis, and at least the third lens group moves along the optical axis, and
- the following conditional expressions are satisfied:
- 2.100<(−f3)/fw<10.000
- 0.050<|m34|/fw<1.250
- where
- f3:
- a focal length of the third lens group,
- fw:
- a focal length of the zoom lens in the wide-angle end state, and
- m34:
- a change in distance between the third lens group and the fourth lens group along the optical axis upon zooming from the wide-angle end state to a telephoto end state.
A method for manufacturing a zoom lens, wherein
- the zoom lens includes, in order from an object along an optical axis:
- a first lens group having a negative refractive power;
- a second lens group having a positive refractive power;
- a third lens group having a negative refractive power;
- a fourth lens group;
- and a fifth lens group, wherein
- the method includes:
- arranging the zoom lens such that, when the zoom lens performs varying magnification, the distance between the first and second lens groups changes, the distance between the second and third lens groups changes, the distance between the third and fourth lens groups changes, the distance between the fourth and fifth lens groups changes, the second and fourth lens groups move along the same trajectory along the optical axis, and at least the third lens group moves along the optical axis, and
- satisfying the following conditional expressions:
- 2.100<(−f3)/fw<10.000
- 0.050<|m34|/fw<1.250
- where
- f3:
- a focal length of the third lens group,
- fw:
- a focal length of the zoom lens in the wide-angle end state, and
- m34:
- a change in distance between the third lens group and the fourth lens group along the optical axis upon zooming from the wide-angle end state to a telephoto end state.
Dependencies are inferred from the claim text.