JP2014153402A5

JP2014153402A5 -

Info

Publication number: JP2014153402A5
Application number: JP2013020378A
Authority: JP
Filing date: 2013-02-05
Publication date: 2016-03-10
Anticipated expiration: 2033-02-05

Description

上述の課題を解決するための第１の側面における本発明のズームレンズは、物体側から像側に順に、実質的に、正屈折力の第１レンズ群、負屈折力の第２レンズ群、正屈折力の第３レンズ群、負屈折力の第４レンズ群、レンズを含む第５レンズ群、正屈折力の第６レンズ群、からなり、第１レンズ群と第２レンズ群との間の距離は、広角端よりも望遠端にて広がり、第２レンズ群と第３レンズ群との間の距離は広角端よりも望遠端にて狭まり、第３レンズ群と第４レンズ群との間の距離は広角端から望遠端への変倍の際に変化し、第４レンズ群と第５レンズ群との間の距離は広角端から望遠端への変倍の際に変化し、第５レンズ群と第６レンズ群との間の距離は広角端から望遠端への変倍の際に変化し、第４レンズ群と第５レンズ群は、フォーカシング動作の際に移動し、以下の条件式（Ａ）を満足することを特徴としている。 The zoom lens according to the first aspect of the present invention for solving the above-mentioned problem is, in order from the object side to the image side, in order, substantially a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having positive refractive power, a fourth lens unit having a negative refractive power, a fifth lens group including a lens, a sixth lens group having positive refractive power and a, between the first lens group and the second lens group Is wider at the telephoto end than at the wide-angle end, the distance between the second lens group and the third lens group is narrower at the telephoto end than at the wide-angle end, and the third lens group and the fourth lens group The distance between the fourth lens group and the fifth lens group changes during zooming from the wide-angle end to the telephoto end, and the distance between the fourth lens group and the fifth lens group changes during zooming from the wide-angle end to the telephoto end. The distance between the fifth lens group and the sixth lens group changes during zooming from the wide-angle end to the telephoto end. The fourth lens group and the fifth lens group Go during Kashingu operation, it is characterized by satisfying the following condition (A).

条件式（２）について
下限値を２、さらには２．５とすることがより好ましい。
上限値を４．５、さらには４とすることがより好ましい。

For conditional expression (2), it is more preferable to set the lower limit value to 2, further 2.5.
Set the upper limit to 4 . More preferably, it is set to 5.

Claims

In order from the object side to the image side ,
A first lens unit having positive refractive power,
A second lens unit having negative refractive power,
A third lens unit having positive refractive power,
A fourth lens unit having a negative refractive power,
A fifth lens group including a lens;
A sixth lens group having positive refractive power ,
The distance between the first lens group and the second lens group is wider at the telephoto end than at the wide angle end,
The distance between the second lens group and the third lens group is narrower at the telephoto end than at the wide-angle end,
The distance between the third lens group and the fourth lens group changes during zooming from the wide-angle end to the telephoto end,
The distance between the fourth lens group and the fifth lens group changes during zooming from the wide-angle end to the telephoto end,
The distance between the fifth lens group and the sixth lens group changes during zooming from the wide-angle end to the telephoto end,
The fourth lens group and the fifth lens group move during a focusing operation, and satisfy the following conditional expression (A).
−0.8 <f4 / f5 <1.2 (A)
However,
f4 is a focal length of the fourth lens group,
f5 is the focal length of the fifth lens group

The zoom lens according to claim 1 , wherein the fourth lens group and the fifth lens group satisfy the following conditional expressions (B) and (C).
−0.7 <f4 / fw <−0.3 (B)
1.0 <| f5 | / fw <5.0 (C)
However,
fw is the focal length at the wide-angle end of the zoom lens,
It is.

Wherein the first lens group distance between the third lens group, a zoom lens according to claim 1 or 2, characterized in that narrowed at the telephoto end than at the wide angle end.

4. The zoom lens according to claim 1, wherein the first lens group is stationary at the time of zooming from the wide-angle end to the telephoto end.

5. The zoom lens according to claim 1, wherein the third lens group is located on the object side at the telephoto end with respect to the wide-angle end.

The zoom lens according to claim 5, wherein the third lens group satisfies the following conditional expression (1).
0.2 <ΔG3 / f3 <1 (1)
However,
ΔG3 is a displacement amount of the position of the third lens group at the telephoto end with respect to the wide angle end, and the displacement toward the object side is positive,
f3 is a focal length of the third lens group,
It is.

7. An aperture stop disposed between the second lens group and the fourth lens group and moving toward the object side at the telephoto end with respect to the wide angle end. The described zoom lens.

The zoom lens according to claim 7, wherein the brightness stop is disposed between the second lens group and the third lens group.

The aperture stop, the zoom lens according to claim 7 or 8, wherein the aperture size at the time of minimum F-number at the telephoto end than at the wide angle end is large.

10. The zoom lens according to claim 1, wherein the fourth lens group and the fifth lens group move during zooming from the wide-angle end to the telephoto end.

The fifth lens group has a negative refractive power, and the moving direction during focusing to a short distance at the wide-angle end and the moving direction during focusing to a short distance at the telephoto end are the same as those of the fourth lens group and the fourth lens group. The zoom lens according to claim 1, wherein the zoom lens is different for five lens groups.

The zoom lens according to claim 1, wherein the fifth lens group has a negative refractive power.

The zoom lens according to claim 1, wherein the fifth lens group has a positive refractive power.

The zoom lens according to any one of claims 1 to 13, wherein the sixth lens group is stationary at the time of zooming from the wide-angle end to the telephoto end.

15. The zoom lens according to claim 1, wherein the second lens group includes a three-piece cemented lens component of a positive lens, a negative lens, and a positive lens in order from the object side to the image side.
Here, the lens component is a lens block in which there are only two refracting surfaces in contact with air in the optical path, the object side surface and the image side surface.

The zoom lens according to claim 1, wherein the three-piece cemented lens component satisfies the following conditional expression (2).
1 <(r21−r22) / (r21 + r22) <5 (2)
However,
r21 is a paraxial radius of curvature of the object side surface of the negative lens in the three-piece cemented lens component;
r22 is a paraxial radius of curvature of the image side surface of the negative lens in the three-piece cemented lens component;
It is.

The zoom lens according to any one of claims 1 to 16, wherein the third lens group includes a negative lens and a plurality of positive lenses, and satisfies the following conditional expressions (3) and (4). .
75 <νd3p <100 (3)
1.4 <f31p / f3 <3.7 (4)
However,
νd3p is the maximum value among the Abbe numbers on the d-line basis of all the positive lenses in the third lens group,
f31p is a focal length of a positive lens closest to the object side in the third lens group,
f3 is a focal length of the third lens group,
It is.

The fourth lens group consists of one negative lens,
The zoom lens according to claim 1, wherein the following conditional expression (5) is satisfied.
0.6 <(r41−r42) / (r41 + r42) <2 (5)
However,
r41 is a paraxial radius of curvature of the object side surface of the negative lens in the fourth lens group;
r42 is a paraxial radius of curvature of the image side surface of the negative lens in the fourth lens group;
It is.

The zoom lens according to claim 1, wherein the fifth lens group includes one lens and satisfies the following conditional expression (6).
-1 <(r51-r52) / (r51 + r52) <4 (6)
However,
r51 is a paraxial radius of curvature of the object side surface of the lens in the fifth lens group;
r52 is a paraxial radius of curvature of the image side surface of the lens in the fifth lens group;
It is.

The zoom lens according to claim 12, wherein the fifth lens group includes one negative lens and satisfies the following conditional expression (6-1).
0 <(r51−r52) / (r51 + r52) <4 (6-1)
However,
r51 is a paraxial radius of curvature of the object side surface of the lens in the fifth lens group;
r52 is a paraxial radius of curvature of the image side surface of the lens in the fifth lens group;
It is.

The zoom lens according to claim 13, wherein the fifth lens group includes one positive lens and satisfies the following conditional expression (6-2).
-1 <(r51-r52) / (r51 + r52) <0 (6-2)
However,
r51 is a paraxial radius of curvature of the object side surface of the lens in the fifth lens group;
r52 is a paraxial radius of curvature of the image side surface of the lens in the fifth lens group;
It is.

At the telephoto end, the fourth lens group and the fifth lens group move while satisfying the following conditional expression (7) at the time of focusing from the infinite focus state to the closest focus state. The zoom lens according to any one of claims 1 to 21.
0.2 <| ΔG5 (T) / ΔG4 (T) | <2 (7)
However,
ΔG4 (T) is the amount of movement of the fourth lens group at the telephoto end during focusing from the infinitely focused state to the closest focused state,
ΔG5 (T) is the amount of movement of the fifth lens group at the telephoto end during focusing from the infinitely focused state to the closest focused state,
It is.

The zoom lens according to claim 1, wherein the following conditional expressions (8) and (9) are satisfied.
3.2 <ft / fw <6 (8)
1.4 <FNO (T) <3.2 (9)
However,
ft is the focal length at the telephoto end of the zoom lens,
fw is the focal length at the wide-angle end of the zoom lens,
FNO (T) is an F number at the telephoto end of the zoom lens.