JP2016118737A5

JP2016118737A5 -

Info

Publication number: JP2016118737A5
Application number: JP2014259747A
Authority: JP
Filing date: 2014-12-24
Publication date: 2018-02-15
Anticipated expiration: 2034-12-24

Description

本発明のズームレンズは、物体側より像側へ順に配置された、正の屈折力の第１レンズ群、負の屈折力の第２レンズ群、正の屈折力の第３レンズ群、負の屈折力の第４レンズ群、正の屈折力の第５レンズ群より構成され、
広角端に比べて望遠端において、前記第１レンズ群と前記第２レンズ群の間隔が広がり、前記第２レンズ群と前記第３レンズ群との間隔が狭まり、前記第３レンズ群と前記第４レンズ群との間隔が変化し、前記第４レンズ群と前記第５レンズ群との間隔が変化するズームレンズであって、
前記第１レンズ群は、最も物体側に配置された、物体側の面が凸形状の第１正レンズを有し、
前記第１レンズ群の中で最も像側に配置されたレンズの像側の面は凹形状であり、
前記第１レンズ群の焦点距離をｆ１、前記第２レンズ群の焦点距離をｆ２、望遠端における前記第２レンズ群の横倍率をβ２ｔとするとき、
−１０．０＜ｆ１／ｆ２＜−４．５
−１０．０＜β２ｔ＜−２．０
なる条件式を満足することを特徴としている。 The zoom lens according to the present invention includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, arranged in order from the object side to the image side. It is composed of a fourth lens group having a refractive power and a fifth lens group having a 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 narrowed, and the third lens group and the third lens group are narrowed. spacing between the fourth lens group is changed, a zoom lens distance is changed between the fifth lens group and the fourth lens group,
Wherein the first lens group, arranged closest to the object side, the object-side surface has a first positive lens element convex shape,
The image side surface of the lens arranged closest to the image side in the first lens group is concave,
When the focal length of the first lens group is f1, the focal length of the second lens group is f2, and the lateral magnification of the second lens group at the telephoto end is β2t,
-10.0 <f1 / f2 <-4.5
−10.0 <β2t <−2.0
It satisfies the following conditional expression.

各実施例において、Ｌ１は正の屈折力の第１レンズ群、Ｌ２は負の屈折力の第２レンズ群、Ｌ３は正の屈折力の第３レンズ群である。Ｌ４は負の屈折力の第４レンズ群、Ｌ５は正の屈折力の第５レンズ群である。開口絞りＳＰは第３レンズ群Ｌ３の物体側に位置している。広角端から望遠端へのズーミングに際して、第２レンズ群Ｌ２は像側に移動する。第４レンズ群Ｌ４は像側に凸状の軌跡で移動する。即ち像側へ移動した後に物体側へ移動する。このとき広角端に比べて望遠端において第１レンズ群Ｌ１と第２レンズ群Ｌ２の間隔が広がり、第２レンズ群Ｌ２と第３レンズ群Ｌ３の間隔が狭まる。 In each embodiment, L1 is a first lens group having a positive refractive power, L2 is a second lens group having a negative refractive power, and L3 is a third lens group having a positive refractive power. L4 is a fourth lens group having a negative refractive power, and L5 is a fifth lens group having a positive refractive power. The aperture stop SP is located on the object side of the third lens unit L3. During zooming from the wide-angle end to the telephoto end, the second lens unit L2 moves to the image side. The fourth lens unit L4 moves along a locus convex toward the image side. That is, it moves to the object side after moving to the image side. At this time, the distance between the first lens group L1 and the second lens group L2 is widened at the telephoto end, and the distance between the second lens group L2 and the third lens group L3 is narrowed at the telephoto end.

開口絞りＳＰは、第２レンズ群Ｌ２より像側で、第３レンズ群Ｌ３の最も像側のレンズ面よりも物体側に配置するのが良い。即ち第２レンズ群Ｌ２と第３レンズ群Ｌ３の間、又は第３レンズ群Ｌ３内に配置するのが良い。このような配置とすることで、レンズ前玉から開口絞りＳＰまでの距離を適切に設定し、前玉有効径が過剰に大きくなることを軽減するのが容易になる。ズーミングに際し、開口絞りＳＰは不動とするのが良い。このような構成にすることで、全体の装置構造を簡素化することが出来、装置全体の小型化が容易になる。 The aperture stop SP is preferably disposed on the image side of the second lens unit L2 and on the object side of the lens surface closest to the image side of the third lens unit L3. That is, it is good to arrange between the second lens group L2 and the third lens group L3 or within the third lens group L3. With such an arrangement, it is easy to appropriately set the distance from the lens front lens to the aperture stop SP and reduce the excessive increase in the front lens effective diameter. It is preferable that the aperture stop SP is not moved during zooming. By adopting such a configuration, the entire apparatus structure can be simplified, and the entire apparatus can be easily downsized.

Claims

A first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a negative refractive power, which are arranged in order from the object side to the image side. A fifth lens unit having a 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 narrowed, and the third lens group and the third lens group are narrowed. spacing between the fourth lens group is changed, a zoom lens distance is changed between the fifth lens group and the fourth lens group,
Wherein the first lens group, arranged closest to the object side, the object-side surface has a first positive lens element convex shape,
The image side surface of the lens arranged closest to the image side in the first lens group is concave,
When the focal length of the first lens group is f1, the focal length of the second lens group is f2, and the lateral magnification of the second lens group at the telephoto end is β2t,
-10.0 <f1 / f2 <-4.5
−10.0 <β2t <−2.0
A zoom lens satisfying the following conditional expression:

During zooming, wherein the first lens group third lens and the fifth lens group and group zoom lens according to claim 1, characterized in that the non-dynamic.

Between the second lens group and the third lens group, or the and third aperture diaphragm is disposed within the lens unit, according to claim 1 or 2, characterized in that the aperture stop during zooming is not dynamic Zoom lens described in 1.

4. The zoom lens according to claim 1, wherein the first lens group includes two or more positive lenses and one or more negative lenses. 5.

5. The zoom lens according to claim 1, wherein the second lens group includes one or more positive lenses and two or more negative lenses. 6.

The third lens group has one positive lens and one or more negative lenses, at least one of the positive lens included in the third lens group, and further comprising a non-spherical surface The zoom lens according to any one of claims 1 to 5.

When the focal length of the third lens group is f3,
3.0 <f1 / f3 <10.0
The zoom lens according to claim 1, wherein the following conditional expression is satisfied.

When the focal length of the third lens group is f3,
−2.0 <f3 / f2 <−0.3
The zoom lens according to claim 1, wherein the following conditional expression is satisfied.

When the focal length of the entire system at the wide angle end is fw,
2.0 <f1 / fw <6.0
The zoom lens according to claim 1, wherein the following conditional expression is satisfied.

When the focal length of the entire system at the wide angle end is fw,
−0.80 <f2 / fw <−0.30
The zoom lens according to claim 1, wherein the following conditional expression is satisfied.

When the focal length of the third lens group is f3 and the focal length of the entire system at the wide angle end is fw,
0.2 <f3 / fw <2.0
The zoom lens according to claim 1, wherein the following conditional expression is satisfied.

When the lateral magnification of the third lens group at the wide-angle end is β3w,
−1.00 <β3w <−0.30
The zoom lens according to claim 1, wherein the following conditional expression is satisfied.

When the lateral magnification of the third lens group at the telephoto end is β3t,
−1.00 <β3t <−0.10
The zoom lens according to claim 1, wherein the following conditional expression is satisfied .

14. At least part of the third lens group moves in a direction having a component in a direction perpendicular to the optical axis during image blur correction, according to any one of claims 1 to 13. Zoom lens.

The zoom lens from the wide-angle end to the telephoto end, the second lens group moves toward the image side, and the fourth lens group moves toward the image side and then moves toward the object side. The zoom lens according to any one of the above.

The zoom lens according to any one of claims 1 to 15, wherein the fourth lens group moves toward the image side during focusing from infinity to a short distance.

A zoom lens according to any one of claims 1 to 16, an imaging apparatus characterized by having an imaging element for receiving an image formed by the zoom lens.