JP2017078772A5

JP2017078772A5 -

Info

Publication number: JP2017078772A5
Application number: JP2015206174A
Authority: JP
Filing date: 2015-10-20
Publication date: 2018-02-08
Anticipated expiration: 2035-10-20

Description

上記目的を達成するために、物体側より像側へ順に、最も物体側に配置されたズーミングのためには移動しない第１のレンズ群を含む１つ以上のレンズ群からなる前レンズ群、３枚以上のレンズを含み負の屈折力を有する中レンズ群、開口絞り、ズーミングに際して移動する第１の後レンズ群、ズーミングに際して移動する第２の後レンズ群、ズーミングのためには移動しない第３の後レンズ群、を含むズームレンズであって、前記前レンズ群は、最も物体側に負レンズが配置され、４枚以上のレンズから構成され、且つ正の屈折力を有する１つ以上のレンズ群を含み、前記第１の後レンズ群の広角端と望遠端の光軸方向の位置差をＭｒ１、前記第２の後レンズ群の広角端と望遠端の光軸方向の位置差をＭｒ２、前記第２の後レンズ群の焦点距離をｆｒ２、広角端の焦点距離をｆｗ、Ｍｒ１、Ｍｒ２は広角端に対して望遠端で像側に位置する場合に正の符号とするとき、
−０．８０＜Ｍｒ２／ｆｒ２＜０．４５
−２．０＜Ｍｒ２／ｆｗ＜０．３
−１５．０＜Ｍｒ１／Ｍｒ２＜２．０
を満足することを特徴とする。 In order to achieve the above object, in order from the object side to the image side, a front lens group including one or more lens groups including a first lens group that does not move for zooming disposed closest to the object side; A middle lens group including at least one lens and having a negative refractive power, an aperture stop, a first rear lens group that moves during zooming, a second rear lens group that moves during zooming, and a third lens that does not move for zooming A zoom lens including a rear lens group, wherein the front lens group includes one or more lenses having a positive refractive power, wherein the negative lens is disposed closest to the object side , and includes four or more lenses. A difference in the optical axis direction between the wide-angle end and the telephoto end of the first rear lens group, and a positional difference in the optical axis direction between the wide-angle end and the telephoto end of the second rear lens group. Focus of the second rear lens group When the distance is fr2 and the focal length at the wide-angle end is fw, Mr1, and Mr2 are located on the image side at the telephoto end with respect to the wide-angle end,
-0.80 <Mr2 / fr2 <0.45
-2.0 <Mr2 / fw <0.3
-15.0 <Mr1 / Mr2 <2.0
It is characterized by satisfying.

また、本発明は、以下の条件式を満足するのが望ましい。
０．４４＜｜ｆｒ１／ｆｒ２｜＜４．９１ …（６）
条件式（６）は第１の後レンズ群の焦点距離と第２の後レンズ群の焦点距離の比を規定した式である。条件式（６）の上限値を超えた場合、ズーミングの際の像面湾曲や倍率色収差の変動の抑制が困難となる。逆に下限値を超えた場合、球面収差の補正が困難となる In the present invention, it is preferable that the following conditional expression is satisfied.
0.44 <| fr1 / fr2 | <4.91 (6)
Conditional expression (6) defines the ratio between the focal length of the first rear lens group and the focal length of the second rear lens group. When the upper limit value of conditional expression (6) is exceeded, it becomes difficult to suppress variations in field curvature and lateral chromatic aberration during zooming. Conversely, if the lower limit is exceeded, it will be difficult to correct spherical aberration.

Claims

In order from the object side to the image side, a front lens group including one or more lens groups including a first lens group that does not move for zooming arranged closest to the object side, and includes a negative lens including three or more lenses. Zoom including a middle lens group having refractive power, an aperture stop, a first rear lens group that moves during zooming, a second rear lens group that moves during zooming, and a third rear lens group that does not move for zooming A lens,
The front lens group includes one or more lens groups in which a negative lens is disposed closest to the object side, includes four or more lenses, and has a positive refractive power.
The positional difference in the optical axis direction between the wide-angle end and the telephoto end of the first rear lens group is Mr1, the positional difference in the optical axis direction between the wide-angle end and the telephoto end of the second rear lens group is Mr2, and the second When the focal length of the rear lens group is fr2, the focal length of the zoom lens at the wide-angle end is fw, Mr1, and Mr2 are set to a positive sign when positioned on the image side at the telephoto end with respect to the wide-angle end,
-0.80 <Mr2 / fr2 <0.45
-2.0 <Mr2 / fw <0.3
-15.0 <Mr1 / Mr2 <2.0
A zoom lens characterized by satisfying