JP2014048370A

JP2014048370A - Variable power optical system, optical device including the variable power optical system, and method for manufacturing the variable power optical system

Info

Publication number: JP2014048370A
Application number: JP2012189688A
Authority: JP
Inventors: Takeshi Uehara; 健上原; Goji Suzuki; 剛司鈴木
Original assignee: Nikon Corp
Current assignee: Nikon Corp
Priority date: 2012-08-30
Filing date: 2012-08-30
Publication date: 2014-03-17
Anticipated expiration: 2032-08-30
Also published as: JP6251947B2

Abstract

PROBLEM TO BE SOLVED: To provide a variable power optical system which has small aberration fluctuations when varying power and has optical performance capable of coping with aberration fluctuations occurring when correcting camera shake, an optical device including the variable power optical system, and a method for manufacturing the variable power optical system.SOLUTION: A variable power optical system ZL to be mounted on a camera 1 or the like, includes, in order from the object side: a first lens group G1 having a negative refractive power; a second lens group G2 having a positive refractive power; a third lens group G3 having a negative refractive power; and a fourth lens group G4 having a positive refractive power. When varying power from a wide angle end state to a telephoto end state, the distance between the first lens group G1 and the second lens group G2 is changed, the distance between the second lens group G2 and the third lens group G3 is changed, and the distance between the third lens group G3 and the fourth lens group G4 is changed. At least one single lens in the second lens group G2 serves as an anti-vibration lens group VL which is moved so as to include a component of a direction perpendicular to the optical axis. The first lens group G1 has a negative lens at the position closest to the object side.

Description

本発明は、変倍光学系、この変倍光学系を有する光学装置、及び、変倍光学系の製造方法に関する。 The present invention relates to a variable magnification optical system, an optical apparatus having the variable magnification optical system, and a method for manufacturing the variable magnification optical system.

従来、写真用カメラ、電子スチルカメラ、ビデオカメラ等に適した変倍光学系が提案されている（例えば、特許文献１参照）。 Conventionally, a variable magnification optical system suitable for a photographic camera, an electronic still camera, a video camera, and the like has been proposed (see, for example, Patent Document 1).

特開平１１−１７４３２９号公報JP-A-11-174329

しかしながら、従来の変倍光学系は、変倍時における収差変動が大きく、また、手ぶれ補正時の収差変動にも対応できていないという課題があった。 However, the conventional variable-power optical system has a problem that the aberration fluctuation at the time of zooming is large and that it cannot cope with the aberration fluctuation at the time of camera shake correction.

本発明はこのような課題に鑑みてなされたものであり、変倍時における収差変動が小さく、手ぶれ補正時の収差変動に対応可能な光学性能を備えた変倍光学系、この変倍光学系を有する光学装置、及び、変倍光学系の製造方法を提供することを目的とする。 The present invention has been made in view of such a problem, and a variable power optical system having an optical performance that is small in aberration fluctuation at the time of zooming and can cope with aberration fluctuation at the time of camera shake correction, and the variable power optical system It is an object of the present invention to provide an optical device having the above and a method for manufacturing a variable magnification optical system.

前記課題を解決するため、本発明に係る変倍光学系は、物体側から順に、負の屈折力を有する第１レンズ群と、正の屈折力を有する第２レンズ群と、負の屈折力を有する第３レンズ群と、正の屈折力を有する第４レンズ群と、を有し、広角端状態から望遠端状態に変倍する際に、第１レンズ群と第２レンズ群との間隔が変化し、第２レンズ群と第３レンズ群との間隔が変化し、第３レンズ群と第４レンズ群との間隔が変化し、第２レンズ群のうちの少なくとも一枚の単レンズは、光軸と直交する方向の成分を含むように移動する防振レンズ群であり、第１レンズ群は、最も物体側に負レンズを有し、次式の条件を満足することを特徴とする。
−２．００＜（Ｒ２＋Ｒ１）／（Ｒ２−Ｒ１）＜ −１．００
但し、
Ｒ１：第１レンズ群の最も物体側の負レンズの物体側面の曲率半径
Ｒ２：第１レンズ群の最も物体側の負レンズの像側面の曲率半径 In order to solve the above problems, a variable magnification optical system according to the present invention includes, in order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a negative refractive power. And a fourth lens group having a positive refractive power, and the distance between the first lens group and the second lens group when zooming from the wide-angle end state to the telephoto end state Changes, the distance between the second lens group and the third lens group changes, the distance between the third lens group and the fourth lens group changes, and at least one single lens in the second lens group is The anti-vibration lens group moves so as to include a component in a direction orthogonal to the optical axis, and the first lens group has a negative lens closest to the object side and satisfies the following condition: .
−2.00 <(R2 + R1) / (R2−R1) <− 1.00
However,
R1: radius of curvature of the object side surface of the negative lens closest to the object side in the first lens group R2: radius of curvature of the image side surface of the negative lens closest to the object side of the first lens group

また、このような変倍光学系において、第３レンズ群は、少なくとも一枚の、両側に空気間隔を有する単レンズを有し、次式の条件を満足することが好ましい。
３．００＜ｆ４／ｄ３ｗ＜９．００
但し、
ｆ４：第４レンズ群の焦点距離
ｄ３ｗ：広角端状態における第３レンズ群と第４レンズ群との空気間隔 In such a variable magnification optical system, it is preferable that the third lens group has at least one single lens having an air interval on both sides, and satisfies the following condition.
3.00 <f4 / d3w <9.00
However,
f4: Focal length of the fourth lens group d3w: Air distance between the third lens group and the fourth lens group in the wide-angle end state

また、このような変倍光学系は、次式の条件を満足することが好ましい。
０．４０＜ｆ１／ｆ３＜１．００
但し、
ｆ１：第１レンズ群の焦点距離
ｆ３：第３レンズ群の焦点距離 Moreover, it is preferable that such a variable magnification optical system satisfies the condition of the following formula.
0.40 <f1 / f3 <1.00
However,
f1: Focal length of the first lens group f3: Focal length of the third lens group

また、このような変倍光学系は、第２レンズ群の中又は近傍に開口絞りを有し、第４レンズ群は、最も像側に正レンズと負レンズとを貼り合わせた接合レンズを有し、次式の条件を満足することが好ましい。
０．１０＜ｄＳｔ／ｆ４＜０．６０
但し、
ｄＳｔ：望遠端状態における開口絞りと第３レンズ群との空気間隔
ｆ４：第４レンズ群の焦点距離 Further, such a variable magnification optical system has an aperture stop in or near the second lens group, and the fourth lens group has a cemented lens in which a positive lens and a negative lens are bonded to the most image side. However, it is preferable to satisfy the condition of the following formula.
0.10 <dSt / f4 <0.60
However,
dSt: Air distance between the aperture stop and the third lens group in the telephoto end state f4: Focal length of the fourth lens group

また、このような変倍光学系において、第１レンズ群のうち、最も物体側のレンズは非球面を有することが好ましい。 In such a variable magnification optical system, it is preferable that the most object side lens in the first lens group has an aspherical surface.

また、このような変倍光学系は、次式の条件を満足することが好ましい。
０．１０＜ｆ２／ｆ２ａ＜０．５５
但し、
ｆ２：第２レンズ群の焦点距離
ｆ２ａ：防振レンズ群の焦点距離 Moreover, it is preferable that such a variable magnification optical system satisfies the condition of the following formula.
0.10 <f2 / f2a <0.55
However,
f2: focal length of the second lens group f2a: focal length of the anti-vibration lens group

また、このような変倍光学系において、第３レンズ群は、単レンズのみからなることが好ましい。 In such a variable magnification optical system, it is preferable that the third lens group is composed of only a single lens.

また、このような変倍光学系において、単レンズは、両凹形状であることが好ましい。 In such a variable magnification optical system, it is preferable that the single lens has a biconcave shape.

また、このような変倍光学系において、第４レンズ群は、少なくとも１面の非球面を有することが好ましい。 In such a variable magnification optical system, it is preferable that the fourth lens group has at least one aspheric surface.

また、このような変倍光学系において、第４レンズ群に含まれる非球面を有するレンズは、第４レンズ群の最も物体側に位置することが好ましい。 In such a variable magnification optical system, it is preferable that the lens having an aspheric surface included in the fourth lens group is positioned closest to the object side of the fourth lens group.

また、このような変倍光学系において、第４レンズ群に含まれる接合レンズのうち、少なくとも一枚はその接合面が像側に凸向きであることが好ましい。 In such a variable magnification optical system, it is preferable that at least one of the cemented lenses included in the fourth lens group has a cemented surface convex toward the image side.

また、このような変倍光学系は、広角端状態から望遠端状態に変倍する際に、第２レンズ群と第３レンズ群との間隔が増大し、第３レンズ群と第４レンズ群との間隔が減少することが好ましい。 Further, in such a variable magnification optical system, when changing the magnification from the wide-angle end state to the telephoto end state, the distance between the second lens group and the third lens group increases, and the third lens group and the fourth lens group. It is preferable that the interval between and decreases.

また、本発明に係る光学装置は、物体の像を所定の像面上に結像させる上述の変倍光学系のいずれかを有して構成される。 The optical apparatus according to the present invention includes any one of the above-described variable magnification optical systems that forms an image of an object on a predetermined image plane.

また、本発明に係る変倍光学系の製造方法は、物体側から順に、負の屈折力を有する第１レンズ群と、正の屈折力を有する第２レンズ群と、負の屈折力を有する第３レンズ群と、正の屈折力を有する第４レンズ群と、を有する変倍光学系の製造方法であって、第１レンズ群、第２レンズ群、第３レンズ群及び第４レンズ群を、広角端状態から望遠端状態に変倍する際に、第１レンズ群と第２レンズ群との間隔が変化し、第２レンズ群と第３レンズ群との間隔が変化し、第３レンズ群と第４レンズ群との間隔が変化するように配置し、第２レンズ群のうちの少なくとも一枚の単レンズを、光軸と直交する方向の成分を含むように移動する防振レンズ群として配置し、第１レンズ群の最も物体側に次式の条件を満足する負レンズを配置することを特徴とする。
−２．００＜（Ｒ２＋Ｒ１）／（Ｒ２−Ｒ１）＜ −１．００
但し、
Ｒ１：第１レンズ群の最も物体側の負レンズの物体側面の曲率半径
Ｒ２：第１レンズ群の最も物体側の負レンズの像側面の曲率半径 The variable magnification optical system manufacturing method according to the present invention has, in order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a negative refractive power. A variable magnification optical system manufacturing method having a third lens group and a fourth lens group having a positive refractive power, the first lens group, the second lens group, the third lens group, and the fourth lens group Is changed from the wide-angle end state to the telephoto end state, the distance between the first lens group and the second lens group is changed, and the distance between the second lens group and the third lens group is changed. An anti-vibration lens that is arranged so that the distance between the lens group and the fourth lens group changes and moves at least one single lens of the second lens group so as to include a component in a direction orthogonal to the optical axis. A negative lens that satisfies the following condition on the most object side of the first lens group. And butterflies.
−2.00 <(R2 + R1) / (R2−R1) <− 1.00
However,
R1: radius of curvature of the object side surface of the negative lens closest to the object side in the first lens group R2: radius of curvature of the image side surface of the negative lens closest to the object side of the first lens group

本発明を以上のように構成すると、変倍時における収差変動が小さく、手ぶれ補正時の収差変動に対応可能な光学性能を備えた変倍光学系、この変倍光学系を有する光学装置、及び、変倍光学系の製造方法を提供することができる。 When the present invention is configured as described above, a variable magnification optical system having an optical performance that is small in aberration variation at the time of zooming and can cope with aberration variation at the time of camera shake correction, an optical device having the variable magnification optical system, and A variable magnification optical system manufacturing method can be provided.

第１実施例に係る変倍光学系のレンズ構成を示す断面図である。It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 1st Example. 第１実施例に係る変倍光学系の広角端状態における諸収差図であって、（ａ）は無限遠合焦状態の収差図であり、（ｂ）は無限遠合焦状態において像ぶれ補正を行ったときのコマ収差図である。FIG. 7A is a diagram illustrating various aberrations in the wide-angle end state of the variable magnification optical system according to the first example, where FIG. 9A is an aberration diagram in the infinite focus state, and FIG. It is a coma aberration figure when performing. 第１実施例に係る変倍光学系の中間焦点距離状態における無限遠合焦状態の諸収差図である。FIG. 7 is a diagram illustrating various aberrations in the infinitely focused state in the intermediate focal length state of the variable magnification optical system according to the first example. 第１実施例に係る変倍光学系の望遠端状態における諸収差図であって、（ａ）は無限遠合焦状態の収差図であり、（ｂ）は無限遠合焦状態において像ぶれ補正を行ったときのコマ収差図である。FIG. 3A is a diagram illustrating various aberrations in the telephoto end state of the variable magnification optical system according to the first example, where FIG. 3A is an aberration diagram in an infinite focus state, and FIG. 3B is an image blur correction in an infinite focus state. It is a coma aberration figure when performing. 第２実施例に係る変倍光学系のレンズ構成を示す断面図である。It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 2nd Example. 第２実施例に係る変倍光学系の広角端状態における諸収差図であって、（ａ）は無限遠合焦状態の収差図であり、（ｂ）は無限遠合焦状態において像ぶれ補正を行ったときのコマ収差図である。FIG. 6A is a diagram illustrating various aberrations in the wide-angle end state of the variable magnification optical system according to Example 2, wherein FIG. 5A is an aberration diagram in the infinite focus state, and FIG. 5B is an image blur correction in the infinite focus state. It is a coma aberration figure when performing. 第２実施例に係る変倍光学系の中間焦点距離状態における無限遠合焦状態の諸収差図である。FIG. 10 is a diagram illustrating various aberrations in the infinitely focused state in the intermediate focal length state of the variable magnification optical system according to the second example. 第２実施例に係る変倍光学系の望遠端状態における諸収差図であって、（ａ）は無限遠合焦状態の収差図であり、（ｂ）は無限遠合焦状態において像ぶれ補正を行ったときのコマ収差図である。FIG. 7A is a diagram illustrating various aberrations in the telephoto end state of the variable magnification optical system according to Example 2, wherein FIG. 9A is an aberration diagram in the infinite focus state, and FIG. 9B is an image blur correction in the infinite focus state. It is a coma aberration figure when performing. 第３実施例に係る変倍光学系のレンズ構成を示す断面図である。It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 3rd Example. 第３実施例に係る変倍光学系の広角端状態における諸収差図であって、（ａ）は無限遠合焦状態の収差図であり、（ｂ）は無限遠合焦状態において像ぶれ補正を行ったときのコマ収差図である。FIG. 6A is an aberration diagram in the wide-angle end state of the variable magnification optical system according to Example 3; FIG. 5A is an aberration diagram in the infinite focus state, and FIG. It is a coma aberration figure when performing. 第３実施例に係る変倍光学系の中間焦点距離状態における無限遠合焦状態の諸収差図である。FIG. 12 is a diagram illustrating various aberrations in the infinitely focused state in the intermediate focal length state of the variable magnification optical system according to the third example. 第３実施例に係る変倍光学系の望遠端状態における諸収差図であって、（ａ）は無限遠合焦状態の収差図であり、（ｂ）は無限遠合焦状態において像ぶれ補正を行ったときのコマ収差図である。FIG. 7A is a diagram illustrating various aberrations in the telephoto end state of the variable magnification optical system according to the third example, where FIG. 9A is an aberration diagram in the infinite focus state, and FIG. 9B is an image blur correction in the infinite focus state. It is a coma aberration figure when performing. 第４実施例に係る変倍光学系のレンズ構成を示す断面図である。It is sectional drawing which shows the lens structure of the variable magnification optical system which concerns on 4th Example. 第４実施例に係る変倍光学系の広角端状態における諸収差図であって、（ａ）は無限遠合焦状態の収差図であり、（ｂ）は無限遠合焦状態において像ぶれ補正を行ったときのコマ収差図である。FIG. 6A is a diagram illustrating various aberrations in the wide-angle end state of the zoom optical system according to the fourth example, where FIG. 5A is an aberration diagram in the infinite focus state, and FIG. 5B is an image blur correction in the infinite focus state. It is a coma aberration figure when performing. 第４実施例に係る変倍光学系の中間焦点距離状態における無限遠合焦状態の諸収差図である。FIG. 11 is a diagram illustrating various aberrations in the infinitely focused state in the intermediate focal length state of the variable magnification optical system according to the fourth example. 第４実施例に係る変倍光学系の望遠端状態における諸収差図であって、（ａ）は無限遠合焦状態の収差図であり、（ｂ）は無限遠合焦状態において像ぶれ補正を行ったときのコマ収差図である。FIG. 9A is a diagram illustrating various aberrations of the zoom optical system according to Example 4 in the telephoto end state, where FIG. 9A is an aberration diagram in the infinite focus state, and FIG. It is a coma aberration figure when performing. 上記変倍光学系を搭載するカメラの断面図を示す。A sectional view of a camera carrying the above-mentioned variable magnification optical system is shown. 上記変倍光学系の製造方法を説明するためのフローチャートである。It is a flowchart for demonstrating the manufacturing method of the said variable magnification optical system.

以下、本発明の好ましい実施形態について図面を参照して説明する。図１に示すように、
本実施形態に係る変倍光学系ＺＬは、物体側から順に、負の屈折力を有する第１レンズ群Ｇ１と、正の屈折力を有する第２レンズ群Ｇ２と、負の屈折力を有する第３レンズ群Ｇ３と、正の屈折力を有する第４レンズ群Ｇ４と、を有して構成される。また、この変倍光学系ＺＬは、広角端状態から望遠端状態に変倍する際に、第１レンズ群Ｇ１と第２レンズ群Ｇ２との間隔が変化し、第２レンズ群Ｇ２と第３レンズ群Ｇ３との間隔が変化し、第３レンズ群Ｇ３と第４レンズ群Ｇ４との間隔が変化する。また、この変倍光学系ＺＬにおいて、第２レンズ群Ｇ２のうちの少なくとも一枚の単レンズ（例えば、図１における両凸レンズＬ２１)は、光軸と直交する方向の成分を含むように移動する防振レンズ群ＶＬである。本実施形態に係る変倍光学系ＺＬをこのように構成すると、変倍時の望遠端におけるコマ収差と広角端における像面湾曲収差とを効果的に補正しつつ、光軸と略直交する方向の所定の像面移動量を確保することができる。さらにまた、この変倍光学系ＺＬにおいて、第１レンズ群Ｇ１は、最も物体側に負レンズ（例えば、図１における負メニスカスレンズＬ１１）を有する。 Preferred embodiments of the present invention will be described below with reference to the drawings. As shown in FIG.
The zoom optical system ZL according to this embodiment includes, in order from the object side, a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, and a first lens group having a negative refractive power. The third lens group G3 includes a third lens group G3 and a fourth lens group G4 having a positive refractive power. In addition, when the zooming optical system ZL zooms from the wide-angle end state to the telephoto end state, the distance between the first lens group G1 and the second lens group G2 changes, and the second lens group G2 and the third lens group G3 change. The distance between the lens group G3 changes and the distance between the third lens group G3 and the fourth lens group G4 changes. In the variable magnification optical system ZL, at least one single lens (for example, the biconvex lens L21 in FIG. 1) of the second lens group G2 moves so as to include a component in a direction orthogonal to the optical axis. This is the image stabilizing lens group VL. When the zoom optical system ZL according to the present embodiment is configured in this manner, the coma aberration at the telephoto end and the field curvature aberration at the wide angle end at the time of zooming are effectively corrected, and the direction substantially orthogonal to the optical axis. A predetermined image plane movement amount can be ensured. Furthermore, in the variable magnification optical system ZL, the first lens group G1 has a negative lens (for example, the negative meniscus lens L11 in FIG. 1) on the most object side.

それでは、このような変倍光学系ＺＬを構成するための条件について説明する。まず、この変倍光学系ＺＬは、以下に示す条件式（１）を満足することが望ましい。 Now, conditions for constructing such a variable magnification optical system ZL will be described. First, it is desirable that the variable magnification optical system ZL satisfies the following conditional expression (1).

−２．００＜（Ｒ２＋Ｒ１）／（Ｒ２−Ｒ１）＜ −１．００（１）
但し、
Ｒ１：第１レンズ群Ｇ１の最も物体側の負レンズの物体側面の曲率半径
Ｒ２：第１レンズ群Ｇ１の最も物体側の負レンズの像側面の曲率半径 −2.00 <(R2 + R1) / (R2−R1) <− 1.00 (1)
However,
R1: radius of curvature of the object side surface of the negative lens closest to the object side in the first lens group G1 R2: radius of curvature of the image side surface of the negative lens closest to the object side of the first lens group G1

条件式（１）は、第１レンズ群Ｇ１の最も物体側に配置された負レンズの形状を規定するための条件式である。この条件式（１）の上限値を上回ると、負レンズの物体側レンズ面の曲率半径が大きくなり、または、像側レンズ面の曲率半径が小さくなり、望遠端における球面収差の補正が困難となるため好ましくない。なお、本願の効果を確実にするために、条件式（１）の上限値を−１．３０にすることが好ましい。反対に、条件式（１）の下限値を下回ると、負レンズの像側レンズ面の曲率半径が小さくなり、または、物体側レンズ面の曲率半径が大きくなり、広角端における像面湾曲収差の補正が困難となるため好ましくない。なお、本願の効果を確実にするために、条件式（１）の下限値を−１．８０にすることが好ましい。 Conditional expression (1) is a conditional expression for defining the shape of the negative lens disposed closest to the object side of the first lens group G1. If the upper limit of conditional expression (1) is exceeded, the radius of curvature of the object side lens surface of the negative lens becomes large, or the radius of curvature of the image side lens surface becomes small, which makes it difficult to correct spherical aberration at the telephoto end. Therefore, it is not preferable. In order to secure the effect of the present application, it is preferable to set the upper limit value of conditional expression (1) to -1.30. On the other hand, if the lower limit of conditional expression (1) is not reached, the radius of curvature of the image side lens surface of the negative lens becomes smaller, or the radius of curvature of the object side lens surface becomes larger, and the field curvature aberration at the wide-angle end becomes larger. Since correction becomes difficult, it is not preferable. In order to secure the effect of the present application, it is preferable to set the lower limit of conditional expression (1) to −1.80.

また、この変倍光学系ＺＬにおいて、第３レンズ群Ｇ３は、少なくとも一枚の、両側に空気間隔を有する単レンズ（例えば、図１における両凹レンズＬ３１）を有し、以下に示す条件式（２）を満足することが望ましい。 In this variable magnification optical system ZL, the third lens group G3 has at least one single lens (for example, a biconcave lens L31 in FIG. 1) having an air gap on both sides, and the following conditional expression ( It is desirable to satisfy 2).

３．００＜ｆ４／ｄ３ｗ＜９．００（２）
但し、
ｆ４：第４レンズ群Ｇ４の焦点距離
ｄ３ｗ：広角端状態における第３レンズ群Ｇ３と第４レンズ群Ｇ４との空気間隔 3.00 <f4 / d3w <9.00 (2)
However,
f4: Focal length of the fourth lens group G4 d3w: Air distance between the third lens group G3 and the fourth lens group G4 in the wide-angle end state

条件式（２）は、第４レンズ群Ｇ４の焦点距離に対する第３レンズ群Ｇ３と第４レンズ群Ｇ４との間隔を規定するための条件式である。この条件式（２）の上限値を上回ると、第３レンズ群Ｇ３と第４レンズ群Ｇ４との空気間隔ｄ３ｗが狭くなり、変倍効率が低下し、広角端における球面収差の補正が困難になるため好ましくない。なお、本願の効果を確実にするために、条件式（２）の上限値を７．００にすることが好ましい。反対に、条件式（２）の下限値を下回ると、第４レンズ群Ｇ４の屈折力が強くなり、広角端における像面湾曲収差の補正が困難になるため好ましくない。なお、本願の効果を確実にするために、条件式（２）の下限値を４．００にすることが好ましい。 Conditional expression (2) is a conditional expression for defining the distance between the third lens group G3 and the fourth lens group G4 with respect to the focal length of the fourth lens group G4. If the upper limit value of the conditional expression (2) is exceeded, the air gap d3w between the third lens group G3 and the fourth lens group G4 becomes narrow, the zooming efficiency decreases, and it becomes difficult to correct spherical aberration at the wide angle end. Therefore, it is not preferable. In order to secure the effect of the present application, it is preferable to set the upper limit of conditional expression (2) to 7.00. On the other hand, if the lower limit of conditional expression (2) is not reached, the refractive power of the fourth lens group G4 becomes strong, and it becomes difficult to correct field curvature aberration at the wide-angle end, which is not preferable. In order to secure the effect of the present application, it is preferable to set the lower limit of conditional expression (2) to 4.00.

また、この変倍光学系ＺＬは、以下に示す条件式（３）を満足することが望ましい。 In addition, it is desirable that the variable magnification optical system ZL satisfies the following conditional expression (3).

０．４０＜ｆ１／ｆ３＜１．００（３）
但し、
ｆ１：第１レンズ群Ｇ１の焦点距離
ｆ３：第３レンズ群Ｇ３の焦点距離 0.40 <f1 / f3 <1.00 (3)
However,
f1: Focal length of the first lens group G1 f3: Focal length of the third lens group G3

条件式（３）は、第３レンズ群Ｇ３の焦点距離に対する第１レンズ群Ｇ１の焦点距離を規定するための条件式である。この条件式（３）の上限値を上回ると、第３レンズ群Ｇ３の屈折力が強くなり、広角端における球面収差の補正が困難となるため好ましくない。なお、本願の効果を確実にするために、条件式（３）の上限値を０．８０にすることが好ましい。反対に、条件式（３）の下限値を下回ると、第１レンズ群Ｇ１の屈折力が強くなり、望遠端における像面湾曲収差の補正が困難となるため好ましくない。なお、本願の効果を確実にするために、条件式（３）の下限値を０．５０にすることが好ましい。 Conditional expression (3) is a conditional expression for defining the focal length of the first lens group G1 with respect to the focal length of the third lens group G3. Exceeding the upper limit of conditional expression (3) is not preferable because the refractive power of the third lens group G3 becomes strong and it becomes difficult to correct spherical aberration at the wide-angle end. In order to secure the effect of the present application, it is preferable to set the upper limit of conditional expression (3) to 0.80. On the other hand, if the lower limit of conditional expression (3) is not reached, the refractive power of the first lens group G1 becomes strong, and it becomes difficult to correct field curvature aberration at the telephoto end, which is not preferable. In order to secure the effect of the present application, it is preferable to set the lower limit of conditional expression (3) to 0.50.

また、本変倍光学系ＺＬは、第２レンズ群Ｇ２の中又は近傍に開口絞りＳを有し、第４レンズ群Ｇ４は、最も像側に正レンズと負レンズとを貼り合わせた接合レンズ（例えば、図１の正メニスカスレンズＬ４２と負メニスカスレンズＬ４２とからなる接合レンズ）を有することが望ましい。第４レンズ群Ｇ４のうち最も像側のレンズに凸凹の貼り合わせレンズを配置することにより広角端における色コマ収差を良好に補正することができる。 The variable magnification optical system ZL has an aperture stop S in or near the second lens group G2, and the fourth lens group G4 is a cemented lens in which a positive lens and a negative lens are bonded to the most image side. (For example, it is desirable to have a cemented lens including the positive meniscus lens L42 and the negative meniscus lens L42 in FIG. 1). By disposing a convex and concave cemented lens on the most image side lens in the fourth lens group G4, it is possible to satisfactorily correct chromatic coma at the wide angle end.

ここで、この変倍光学系ＺＬは、以下に示す条件式（４）を満足することが望ましい。 Here, it is desirable that the variable magnification optical system ZL satisfies the following conditional expression (4).

０．１０＜ｄＳｔ／ｆ４＜０．６０（４）
但し、
ｄＳｔ：望遠端状態における開口絞りＳと第３レンズ群Ｇ３との空気間隔
ｆ４：第４レンズ群Ｇ４の焦点距離 0.10 <dSt / f4 <0.60 (4)
However,
dSt: Air gap between the aperture stop S and the third lens group G3 in the telephoto end state f4: Focal length of the fourth lens group G4

条件式（４）は、第４レンズ群Ｇ４の焦点距離に対する望遠端状態における開口絞りＳの位置を規定するための条件式である。この条件式（４）の上限値を上回ると、開口絞りＳと第３レンズ群Ｇ３との間隔が広くなり過ぎ、望遠端における像面湾曲収差の補正が困難となるため好ましくない。なお、本願の効果を確実にするために、条件式（４）の下限値を０．５０にすることが好ましい。反対に、条件式（４）の下限値を下回ると、開口絞りＳと第３レンズ群Ｇ３との間隔が狭くなり過ぎ、望遠端における球面収差の補正が困難となるため好ましくない。なお、本願の効果を確実にするために、条件式（４）の下限値を０．１５にすることが好ましい。 Conditional expression (4) is a conditional expression for defining the position of the aperture stop S in the telephoto end state with respect to the focal length of the fourth lens group G4. Exceeding the upper limit value of conditional expression (4) is not preferable because the distance between the aperture stop S and the third lens group G3 becomes too wide and it becomes difficult to correct field curvature aberration at the telephoto end. In order to secure the effect of the present application, it is preferable to set the lower limit of conditional expression (4) to 0.50. On the other hand, if the lower limit value of conditional expression (4) is not reached, the distance between the aperture stop S and the third lens group G3 becomes too narrow, which makes it difficult to correct spherical aberration at the telephoto end, which is not preferable. In order to secure the effect of the present application, it is preferable to set the lower limit of conditional expression (4) to 0.15.

また、この変倍光学系ＺＬにおいて、第１レンズ群Ｇ１のうち、最も物体側のレンズは非球面を有することが好ましい（例えば、図１における非球面負レンズＬ１１の像側の面（第３面））。この構成により、広角端における像面湾曲収差と望遠端における球面収差とを効果的に補正することができる。 In the variable magnification optical system ZL, it is preferable that the most object side lens in the first lens group G1 has an aspherical surface (for example, the image side surface of the aspherical negative lens L11 in FIG. surface)). With this configuration, it is possible to effectively correct the field curvature aberration at the wide angle end and the spherical aberration at the telephoto end.

また、この変倍光学系ＺＬは、以下に示す条件式（５）を満足することが望ましい。 In addition, it is desirable that the variable magnification optical system ZL satisfies the following conditional expression (5).

０．１０＜ｆ２／ｆ２ａ＜０．５５（５）
但し、
ｆ２：第２レンズ群Ｇ２の焦点距離
ｆ２ａ：防振レンズ群ＶＬの焦点距離 0.10 <f2 / f2a <0.55 (5)
However,
f2: focal length of the second lens group G2 f2a: focal length of the image stabilizing lens group VL

条件式（５）は、第２レンズ群Ｇ２の焦点距離に対する防振レンズ群ＶＬの焦点距離を規定するための条件式である。この条件式（５）の上限値を上回ると、防振レンズ群ＶＬの屈折力が強くなり、広角端における像面湾曲収差の補正が困難となるため好ましくない。なお、本願の効果を確実にするために、条件式（５）の上限値を０．５０にすることが好ましい。反対に、条件式（５）の下限値を下回ると、防振レンズ群ＶＬの屈折力が弱くなり、望遠端におけるコマ収差の補正が困難となるため好ましくない。なお、本願の効果を確実にするために、条件式（５）の下限値を０．２０にすることが好ましい。 Conditional expression (5) is a conditional expression for defining the focal length of the image stabilizing lens group VL with respect to the focal length of the second lens group G2. Exceeding the upper limit of conditional expression (5) is not preferable because the refractive power of the image stabilizing lens group VL becomes strong and it becomes difficult to correct field curvature aberration at the wide angle end. In order to secure the effect of the present application, it is preferable to set the upper limit of conditional expression (5) to 0.50. On the other hand, if the lower limit of conditional expression (5) is not reached, the refractive power of the image stabilizing lens group VL becomes weak, and it becomes difficult to correct coma at the telephoto end. In order to secure the effect of the present application, it is preferable to set the lower limit of conditional expression (5) to 0.20.

また、このような変倍光学系ＺＬにおいて、第３レンズ群Ｇ３は、単レンズのみからなることが望ましい。この構成により、望遠端における像面湾曲収差とコマ収差とを効果的に補正することができる。 In such a variable magnification optical system ZL, it is desirable that the third lens group G3 includes only a single lens. With this configuration, it is possible to effectively correct curvature of field aberration and coma at the telephoto end.

また、このような変倍光学系ＺＬにおいて、第３レンズ群Ｇ３を構成する単レンズは、両凹形状であることが望ましい。この構成によっても、望遠端における像面湾曲収差とコマ収差とを効果的に補正することができる。 In such a variable magnification optical system ZL, it is desirable that the single lenses constituting the third lens group G3 have a biconcave shape. Also with this configuration, it is possible to effectively correct field curvature aberration and coma at the telephoto end.

また、このような変倍光学系ＺＬにおいて、第４レンズ群Ｇ４は、少なくとも１面の非球面（例えば、図１における第１７面）を有することが望ましい。この構成により、広角端における像面湾曲収差とコマ収差とを効果的に補正することができる。 In such a variable magnification optical system ZL, it is desirable that the fourth lens group G4 has at least one aspheric surface (for example, the seventeenth surface in FIG. 1). With this configuration, it is possible to effectively correct field curvature aberration and coma aberration at the wide angle end.

また、この変倍光学系ＺＬにおいて、第４レンズ群Ｇ４に含まれる非球面を有するレンズ（例えば、図１における非球面正レンズＬ４１）は、第４レンズ群Ｇ４の最も物体側に位置することが好ましい。この構成により、望遠端における像面湾曲収差とコマ収差とを効果的に補正することができる。 In the variable magnification optical system ZL, a lens having an aspheric surface (for example, the aspheric positive lens L41 in FIG. 1) included in the fourth lens group G4 is located closest to the object side of the fourth lens group G4. Is preferred. With this configuration, it is possible to effectively correct curvature of field aberration and coma at the telephoto end.

また、この変倍光学系ＺＬにおいて、第４レンズ群Ｇ４に含まれる接合レンズのうち、少なくとも一枚はその接合面が像側に凸向きであることが好ましい（例えば、図１における第１９面）。この構成により、広角端における色コマ収差を効果的に補正することができる。 In the zoom optical system ZL, it is preferable that at least one of the cemented lenses included in the fourth lens group G4 has a cemented surface convex toward the image side (for example, the 19th surface in FIG. 1). ). With this configuration, chromatic coma at the wide-angle end can be effectively corrected.

また、この変倍光学系ＺＬは、広角端状態から望遠端状態に変倍する際に、第２レンズ群Ｇ２と第３レンズ群Ｇ３との間隔が増大し、第３レンズ群Ｇ３と第４レンズ群Ｇ４との間隔が減少することが好ましい。この構成により、球面収差と像面湾曲の変動を効果的に補正しつつ、所定の変倍比を確保することができる。 Further, in the zoom optical system ZL, when zooming from the wide-angle end state to the telephoto end state, the distance between the second lens group G2 and the third lens group G3 increases, and the third lens group G3 and the fourth lens group G4 It is preferable that the distance from the lens group G4 is reduced. With this configuration, it is possible to ensure a predetermined zoom ratio while effectively correcting variations in spherical aberration and curvature of field.

次に、本実施形態に係る変倍光学系ＺＬを備えた光学装置であるカメラを図１７に基づいて説明する。このカメラ１は、撮影レンズ２として本実施形態に係る変倍光学系ＺＬを備えたレンズ交換式の所謂ミラーレスカメラである。本カメラ１において、不図示の物体（被写体）からの光は、撮影レンズ２で集光されて、不図示のＯＬＰＦ（Optical low pass filter：光学ローパスフィルタ）を介して撮像部３の撮像面上に被写体像を形成する。そして、撮像部３に設けられた光電変換素子により被写体像が光電変換されて被写体の画像が生成される。この画像は、カメラ１に設けられたＥＶＦ（Electronic view finder：電子ビューファインダ）４に表示される。これにより撮影者は、ＥＶＦ４を介して被写体を観察することができる。 Next, a camera that is an optical device including the variable magnification optical system ZL according to the present embodiment will be described with reference to FIG. This camera 1 is a so-called mirrorless camera of interchangeable lens provided with a variable magnification optical system ZL according to the present embodiment as a photographing lens 2. In the camera 1, light from an object (subject) (not shown) is collected by the photographing lens 2 and is on the imaging surface of the imaging unit 3 via an OLPF (Optical low pass filter) (not shown). A subject image is formed on the screen. Then, the subject image is photoelectrically converted by the photoelectric conversion element provided in the imaging unit 3 to generate an image of the subject. This image is displayed on an EVF (Electronic view finder) 4 provided in the camera 1. Thus, the photographer can observe the subject via the EVF 4.

また、撮影者によって不図示のレリーズボタンが押されると、撮像部３により光電変換された画像が不図示のメモリに記憶される。このようにして、撮影者は本カメラ１による被写体の撮影を行うことができる。なお、本実施形態では、ミラーレスカメラの例を説明したが、カメラ本体にクイックリターンミラーを有しファインダー光学系により被写体を観察する一眼レフタイプのカメラに本実施形態に係る変倍光学系ＺＬを搭載した場合でも、上記カメラ１と同様の効果を奏することができる。 Further, when a release button (not shown) is pressed by the photographer, an image photoelectrically converted by the imaging unit 3 is stored in a memory (not shown). In this way, the photographer can shoot the subject with the camera 1. In the present embodiment, an example of a mirrorless camera has been described. However, a variable power optical system ZL according to the present embodiment is applied to a single-lens reflex camera that has a quick return mirror in the camera body and observes a subject with a finder optical system. Even when the camera is mounted, the same effect as the camera 1 can be obtained.

なお、以下に記載の内容は、光学性能を損なわない範囲で適宜採用可能である。 The contents described below can be appropriately adopted as long as the optical performance is not impaired.

本実施形態では、４群構成の変倍光学系ＺＬを示したが、以上の構成条件等は、５群、６群等の他の群構成にも適用可能である。また、最も物体側にレンズまたはレンズ群を追加した構成や、最も像側にレンズまたはレンズ群を追加した構成でも構わない。また、レンズ群とは、変倍時に変化する空気間隔で分離された、少なくとも１枚のレンズを有する部分を示す。 In the present embodiment, the variable magnification optical system ZL having the four-group configuration is shown, but the above-described configuration conditions and the like can be applied to other group configurations such as the fifth group and the sixth group. Further, a configuration in which a lens or a lens group is added to the most object side, or a configuration in which a lens or a lens group is added to the most image side may be used. The lens group refers to a portion having at least one lens separated by an air interval that changes during zooming.

また、単独または複数のレンズ群、または部分レンズ群を光軸方向に移動させて、無限遠物体から近距離物体への合焦を行う合焦レンズ群としても良い。この場合、合焦レンズ群はオートフォーカスにも適用でき、オートフォーカス用の（超音波モーター等の）モーター駆動にも適している。特に、前述のように、第１レンズ群Ｇ１の少なくとも一部を合焦レンズ群とするのが好ましい。 Alternatively, a single lens group, a plurality of lens groups, or a partial lens group may be moved in the optical axis direction to be a focusing lens group that performs focusing from an object at infinity to a near object. In this case, the focusing lens group can be applied to autofocus, and is also suitable for driving a motor for autofocus (such as an ultrasonic motor). In particular, as described above, it is preferable that at least a part of the first lens group G1 is a focusing lens group.

また、レンズ群または部分レンズ群を光軸に垂直な方向の成分を持つように移動させ、または、光軸を含む面内方向に回転移動（揺動）させて、手ぶれによって生じる像ぶれを補正する防振レンズ群としてもよい。特に、前述のように、第２レンズ群Ｇ２の少なくとも一部を防振レンズ群とするのが好ましい。 Also, by moving the lens group or partial lens group so that it has a component in the direction perpendicular to the optical axis, or rotating (swinging) in the in-plane direction including the optical axis, image blur caused by camera shake is corrected. An anti-vibration lens group may be used. In particular, as described above, it is preferable that at least a part of the second lens group G2 is a vibration-proof lens group.

また、レンズ面は、球面または平面で形成されても、非球面で形成されても構わない。レンズ面が球面または平面の場合、レンズ加工及び組立調整が容易になり、加工及び組立調整の誤差による光学性能の劣化を妨げるので好ましい。また、像面がずれた場合でも描写性能の劣化が少ないので好ましい。レンズ面が非球面の場合、非球面は、研削加工による非球面、ガラスを型で非球面形状に形成したガラスモールド非球面、ガラスの表面に樹脂を非球面形状に形成した複合型非球面のいずれの非球面でも構わない。また、レンズ面は回折面としても良く、レンズを屈折率分布型レンズ（ＧＲＩＮレンズ）或いはプラスチックレンズとしても良い。 Further, the lens surface may be formed as a spherical surface, a flat surface, or an aspheric surface. It is preferable that the lens surface is a spherical surface or a flat surface because lens processing and assembly adjustment are facilitated, and deterioration of optical performance due to errors in processing and assembly adjustment is prevented. Further, even when the image plane is deviated, it is preferable because there is little deterioration in drawing performance. When the lens surface is an aspheric surface, the aspheric surface is an aspheric surface by grinding, a glass mold aspheric surface made of glass with an aspheric shape, or a composite aspheric surface made of resin with an aspheric shape on the glass surface. Any aspherical surface may be used. The lens surface may be a diffractive surface, and the lens may be a gradient index lens (GRIN lens) or a plastic lens.

開口絞りＳは、第２レンズ群Ｇ２中または近傍に配置されるのが好ましいが、開口絞りとしての部材を設けずに、レンズの枠でその役割を代用しても良い。 The aperture stop S is preferably disposed in or near the second lens group G2, but the role of the aperture stop S may be substituted by a lens frame without providing a member as an aperture stop.

さらに、各レンズ面には、フレアやゴーストを軽減し高コントラストの高い光学性能を達成するために、広い波長域で高い透過率を有する反射防止膜を施しても良い。 Further, each lens surface may be provided with an antireflection film having a high transmittance in a wide wavelength region in order to reduce flare and ghost and achieve high optical performance with high contrast.

また、本実施形態の変倍光学系ＺＬは、変倍比が２．０〜５．０程度である。 The variable magnification optical system ZL of the present embodiment has a variable magnification ratio of about 2.0 to 5.0.

以下、本実施形態に係る変倍光学系ＺＬの製造方法の概略を、図１８を参照して説明する。まず、各レンズを配置してレンズ群Ｇ１〜Ｇ４をそれぞれ準備する（ステップＳ１００）。また、広角端状態から望遠端状態まで変倍する際に、第１レンズ群Ｇ１と第２レンズ群Ｇ２との間隔が変化し、第２レンズ群Ｇ２と第３レンズ群Ｇ３との間隔が変化し、第３レンズ群Ｇ３と第４レンズ群Ｇ４との間隔が変化するよう配置する（ステップＳ２００）。また、第２レンズ群Ｇ２のうちの少なくとも一枚の単レンズを、光軸と直交する方向の成分を含むように移動する防振レンズ群ＶＬとして配置する（ステップＳ３００）。さらにまた、第１レンズ群Ｇ１の最も物体側に前述の条件式（１）を満足する負レンズを配置する(ステップＳ４００)。 Hereinafter, an outline of a method for manufacturing the variable magnification optical system ZL according to the present embodiment will be described with reference to FIG. First, the lenses are arranged to prepare lens groups G1 to G4, respectively (step S100). Further, when zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group G1 and the second lens group G2 changes, and the distance between the second lens group G2 and the third lens group G3 changes. Then, it arrange | positions so that the space | interval of the 3rd lens group G3 and 4th lens group G4 may change (step S200). In addition, at least one single lens in the second lens group G2 is arranged as a vibration-proof lens group VL that moves so as to include a component in a direction orthogonal to the optical axis (step S300). Furthermore, a negative lens that satisfies the above-described conditional expression (1) is disposed closest to the object side of the first lens group G1 (step S400).

具体的には、本実施形態では、例えば図１に示すように、物体側から順に、物体側に凸面を向けた負メニスカスレンズ形状の非球面負レンズＬ１１、物体側に凸面を向けた負メニスカスレンズＬ１２、及び、物体側に凸面を向けた正メニスカスレンズＬ１３を配置して第１レンズ群Ｇ１とし、物体側から順に、両凸レンズＬ２１、及び、物体側に凸面を向けた負メニスカスレンズＬ２２と両凸レンズＬ２３との接合レンズを配置して第２レンズ群Ｇ２とし、両凹レンズＬ３１を配置して第３レンズ群Ｇ３とし、物体側から順に、物体側に凸面を向けた正メニスカスレンズ形状の非球面正レンズＬ４１、及び、物体側に凹面を向けた正メニスカスレンズＬ４２と物体側に凹面を向けた負メニスカスレンズＬ４３との接合レンズを配置して第４レンズ群Ｇ４とする。このようにして準備した各レンズ群を上述の手順で配置して変倍光学系ＺＬを製造する。 Specifically, in the present embodiment, for example, as shown in FIG. 1, in order from the object side, a negative meniscus negative lens L11 having a negative meniscus lens shape with a convex surface facing the object side, and a negative meniscus with a convex surface facing the object side. A lens L12 and a positive meniscus lens L13 having a convex surface facing the object side are arranged as a first lens group G1, and in order from the object side, a biconvex lens L21 and a negative meniscus lens L22 having a convex surface facing the object side; A cemented lens with a biconvex lens L23 is arranged to form a second lens group G2, and a biconcave lens L31 is arranged to form a third lens group G3. A non-positive meniscus lens having a convex surface facing the object side in order from the object side. A spherical positive lens L41, and a cemented lens of a positive meniscus lens L42 having a concave surface facing the object side and a negative meniscus lens L43 having a concave surface facing the object side are arranged to form a fourth lens. And's group G4. The lens groups thus prepared are arranged according to the above-described procedure to manufacture the variable magnification optical system ZL.

以下、本願の各実施例を、図面に基づいて説明する。なお、図１、図５、図９及び図１３は、各実施例に係る変倍光学系ＺＬ（ＺＬ１〜ＺＬ４）の構成及び屈折力配分並びに無限遠合焦状態から近距離合焦状態への合焦状態の変化における各レンズ群の移動の様子を示す断面図である。また、これらの変倍光学系ＺＬ１〜ＺＬ４の断面図の下部には、広角端状態（Ｗ）から望遠端状態（Ｔ）に変倍する際の各レンズ群Ｇ１〜Ｇ４の光軸に沿った移動方向が矢印で示されている。また、図１、図５、図９及び図１３に示すように、第１〜第４実施例に係る変倍光学系ＺＬ１〜ＺＬ４は、物体側から順に、負の屈折力を有する第１レンズ群Ｇ１と、正の屈折力を有する第２レンズ群Ｇ２と、負の屈折力を有する第３レンズ群Ｇ３と、正の屈折力を有する第４レンズ群Ｇ４とから構成されている。そして、広角端状態から望遠端状態への変倍に際し、第１レンズ群Ｇ１と第２レンズ群Ｇ２との空気間隔が変化し、第２レンズ群Ｇ２と第３レンズ群Ｇ３との空気間隔が増大し、第３レンズ群Ｇ３と第４レンズ群Ｇ４との空気間隔が減少するように、各レンズ群の間隔が変化する。 Hereinafter, each example of the present application will be described with reference to the drawings. 1, FIG. 5, FIG. 9 and FIG. 13 show the configuration and refractive power distribution of the variable magnification optical system ZL (ZL1 to ZL4) according to each example, and from the infinitely focused state to the short-distance focused state. It is sectional drawing which shows the mode of the movement of each lens group in the change of a focusing state. Further, in the lower part of the sectional views of these zoom optical systems ZL1 to ZL4, along the optical axes of the lens groups G1 to G4 when zooming from the wide-angle end state (W) to the telephoto end state (T) The direction of movement is indicated by an arrow. As shown in FIGS. 1, 5, 9, and 13, the variable magnification optical systems ZL1 to ZL4 according to the first to fourth examples are first lenses having negative refractive power in order from the object side. The lens unit includes a group G1, a second lens group G2 having a positive refractive power, a third lens group G3 having a negative refractive power, and a fourth lens group G4 having a positive refractive power. Then, during zooming from the wide-angle end state to the telephoto end state, the air gap between the first lens group G1 and the second lens group G2 changes, and the air gap between the second lens group G2 and the third lens group G3 changes. The distance between the lens groups changes so that the air distance between the third lens group G3 and the fourth lens group G4 decreases and increases.

各実施例において、非球面は、光軸に垂直な方向の高さをｙとし、高さｙにおける各非球面の頂点の接平面から各非球面までの光軸に沿った距離（サグ量）をＳ（ｙ）とし、基準球面の曲率半径（近軸曲率半径）をｒとし、円錐定数をκとし、ｎ次の非球面係数をＡnとしたとき、以下の式（ａ）で表される。 In each embodiment, the height of the aspheric surface in the direction perpendicular to the optical axis is y, and the distance (sag amount) along the optical axis from the tangential plane of the apex of each aspheric surface to each aspheric surface at height y. Is S (y), r is the radius of curvature of the reference sphere (paraxial radius of curvature), κ is the conic constant, and An is the nth-order aspheric coefficient, and is expressed by the following equation (a). .

Ｓ（ｙ）＝（ｙ²／ｒ）／｛１＋（１−κ×ｙ²／ｒ²）^1/2｝
＋Ａ4×ｙ⁴＋Ａ6×ｙ⁶＋Ａ8×ｙ⁸＋Ａ10×ｙ¹⁰ （ａ） S (y) = (y ² / r) / {1+ (1−κ × y ² / r ² ) ^1/2 }
+ A4 × y ⁴ + A6 × y ⁶ + A8 × y ⁸ + A10 × y ¹⁰ (a)

なお、各実施例において、２次の非球面係数Ａ2は０である。また、各実施例の表中において、非球面には面番号の右側に＊印を付している。また、以降の実施例において、「Ｅ−ｎ」は「×１０^-n」を示す。 In each embodiment, the secondary aspheric coefficient A2 is zero. In the table of each example, an aspherical surface is marked with * on the right side of the surface number. In the following examples, “E−n” indicates “× 10 ⁻ⁿ ”.

〔第１実施例〕
図１は、第１実施例に係る変倍光学系ＺＬ１の構成を示す図である。この図１に示す変倍光学系ＺＬ１において、第１レンズ群Ｇ１は、物体側から順に、物体側に凸面を向けた負メニスカスレンズ形状の非球面負レンズＬ１１、物体側に凸面を向けた負メニスカスレンズＬ１２、及び、物体側に凸面を向けた正メニスカスレンズＬ１３から構成されている。ここで、非球面負レンズＬ１１は、像側のガラスレンズ面（第２面）に樹脂層を設け、その樹脂層の像側の面（第３面）が非球面形状に形成されている。第２レンズ群Ｇ２は、物体側から順に、両凸レンズＬ２１、及び、物体側に凸面を向けた負メニスカスレンズＬ２２と両凸レンズＬ２３との接合レンズから構成されている。第３レンズ群Ｇ３は、両凹レンズＬ３１から構成されている。第４レンズ群Ｇ４は、物体側から順に、物体側に凸面を向けた正メニスカスレンズ形状の非球面正レンズＬ４１、及び、物体側に凹面を向けた正メニスカスレンズＬ４２と物体側に凹面を向けた負メニスカスレンズＬ４３との接合レンズから構成されている。ここで、非球面正レンズＬ４１はその像側の面（第１７面）が非球面形状に形成されている。 [First embodiment]
FIG. 1 is a diagram showing a configuration of a variable magnification optical system ZL1 according to the first example. In the variable magnification optical system ZL1 shown in FIG. 1, the first lens group G1 includes, in order from the object side, an aspheric negative lens L11 having a negative meniscus lens shape with a convex surface facing the object side, and a negative surface with a convex surface facing the object side. It comprises a meniscus lens L12 and a positive meniscus lens L13 having a convex surface facing the object side. Here, in the aspheric negative lens L11, a resin layer is provided on the glass lens surface (second surface) on the image side, and the image side surface (third surface) of the resin layer is formed in an aspheric shape. The second lens group G2 includes, in order from the object side, a biconvex lens L21 and a cemented lens of a negative meniscus lens L22 having a convex surface facing the object side and a biconvex lens L23. The third lens group G3 is composed of a biconcave lens L31. The fourth lens group G4 includes, in order from the object side, an aspheric positive lens L41 having a positive meniscus lens shape with a convex surface facing the object side, a positive meniscus lens L42 with a concave surface facing the object side, and a concave surface facing the object side. Further, it is composed of a cemented lens with a negative meniscus lens L43. Here, the image-side surface (the 17th surface) of the aspherical positive lens L41 is formed in an aspherical shape.

また、開口絞りＳは、第２レンズ群Ｇ２と第３レンズ群Ｇ３との間に位置し、広角端状態から望遠端状態への変倍に際して第２レンズ群Ｇ２とともに移動する。また、無限遠から近距離物体への合焦は、第１レンズ群Ｇ１を物体方向に繰り出す（移動させる）ことにより行う。 The aperture stop S is located between the second lens group G2 and the third lens group G3, and moves together with the second lens group G2 upon zooming from the wide-angle end state to the telephoto end state. Further, focusing from infinity to a close object is performed by extending (moving) the first lens group G1 in the object direction.

また、像ぶれ補正（防振）は、第２レンズ群Ｇ２の両凸レンズＬ２１を防振レンズ群ＶＬとし、この防振レンズ群ＶＬを光軸と直交する方向の成分を含むように移動させることにより行う。 In image blur correction (anti-shake), the biconvex lens L21 of the second lens group G2 is used as the anti-shake lens group VL, and the anti-shake lens group VL is moved so as to include a component in a direction perpendicular to the optical axis. To do.

なお、全系の焦点距離がｆで、防振係数（像ぶれ補正での防振レンズ群ＶＬの移動量に対する結像面での像移動量の比）がＫのレンズで角度θの回転ぶれを補正するには、ぶれ補正用の防振レンズ群ＶＬを（ｆ・ｔａｎθ）／Ｋだけ光軸と直交方向に移動させればよい（以降の実施例においても同様である）。この第１実施例の広角端状態においては、防振係数は０．５０であり、焦点距離は１８．５０（ｍｍ）であるので、０．４３°の回転ぶれを補正するための防振レンズ群ＶＬの移動量は０．２８（ｍｍ）である。また、この第１実施例の望遠端状態においては、防振係数は０．８３であり、焦点距離は５３．４０（ｍｍ）であるので、０．２６°の回転ぶれを補正するための防振レンズ群ＶＬの移動量は０．２９（ｍｍ）である。 It is to be noted that the focal length of the entire system is f, and the image stabilization coefficient (ratio of the amount of image movement on the imaging surface to the amount of movement of the image stabilization lens group VL in image blur correction) is K. Can be corrected by moving the image stabilizing lens group VL for blur correction by (f · tan θ) / K in the direction orthogonal to the optical axis (the same applies to the following embodiments). In the first embodiment, in the wide-angle end state, the image stabilization coefficient is 0.50 and the focal length is 18.50 (mm). Therefore, the image stabilization lens for correcting the rotation blur of 0.43 ° is used. The movement amount of the group VL is 0.28 (mm). Further, in the telephoto end state of the first embodiment, since the image stabilization coefficient is 0.83 and the focal length is 53.40 (mm), the anti-vibration for correcting the rotation blur of 0.26 °. The moving amount of the vibration lens group VL is 0.29 (mm).

以下の表１に、第１実施例の諸元の値を掲げる。この表１において、ｆは焦点距離、ＦＮＯはＦナンバー、２ωは画角、ＴＬは全長をそれぞれ表している。ここで、全長ＴＬは、無限遠合焦時のレンズ面の第１面から像面Ｉまでの光軸上の距離を表している。さらに、レンズデータの第１欄ｍは、光線の進行する方向に沿った物体側からのレンズ面の順序（面番号）を、第２欄ｒは、各レンズ面の曲率半径を、第３欄ｄは、各光学面から次の光学面までの光軸上の距離（面間隔）を、第４欄νｄ及び第５欄ｎｄは、ｄ線（λ＝５８７．６ｎｍ）に対するアッベ数及び屈折率を示している。また、曲率半径0.0000は平面を示し、空気の屈折率1.00000は省略してある。なお、表１に示す面番号１〜２０は、図１に示す番号１〜２０に対応している。また、レンズ群焦点距離は第１〜第４レンズ群Ｇ１〜Ｇ４の各々の始面と焦点距離を示している。ここで、以下の全ての諸元値において掲載されている焦点距離ｆ、曲率半径ｒ、面間隔ｄ、その他長さの単位は一般に「ｍｍ」が使われるが、光学系は、比例拡大または比例縮小しても同等の光学性能が得られるので、これに限られるものではない。また、これらの符号の説明及び諸元表の説明は以降の実施例においても同様である。 Table 1 below lists values of specifications of the first embodiment. In Table 1, f represents the focal length, FNO represents the F number, 2ω represents the angle of view, and TL represents the total length. Here, the total length TL represents the distance on the optical axis from the first surface of the lens surface to the image plane I when focusing on infinity. Further, the first column m of the lens data indicates the order (surface number) of the lens surfaces from the object side along the traveling direction of the light beam, the second column r indicates the curvature radius of each lens surface, and the third column. d is the distance on the optical axis from each optical surface to the next optical surface (surface interval). The fourth column νd and the fifth column nd are Abbe numbers and refractive indices for the d-line (λ = 587.6 nm). Is shown. The radius of curvature of 0.0000 indicates a plane, and the refractive index of air of 1.0000 is omitted. The surface numbers 1 to 20 shown in Table 1 correspond to the numbers 1 to 20 shown in FIG. The lens group focal length indicates the start surface and focal length of each of the first to fourth lens groups G1 to G4. Here, the focal length f, the radius of curvature r, the surface interval d, and other length units listed in all the following specification values are generally “mm”, but the optical system is proportionally enlarged or proportional. Since the same optical performance can be obtained even if the image is reduced, the present invention is not limited to this. The description of these symbols and the description of the specification table are the same in the following embodiments.

（表１）
［全体諸元］
広角端状態中間焦点距離状態望遠端状態
ｆ＝ 18.50 〜 45.00 〜 53.40
ＦＮＯ＝ 3.64 〜 5.35 〜 5.88
２ω ＝ 78.1 〜 35.0 〜 29.7
ＴＬ＝ 122.38 〜 119.93 〜 124.96

［レンズデータ］
ｍｒｄ νｄｎｄ
1 66.21 1.60 63.9 1.51680
2 15.70 0.17 38.1 1.55389
3* 13.42 10.50
4 262.72 1.20 58.1 1.62299
5 21.53 1.10
6 21.37 4.40 28.4 1.72825
7 57.46 d7
8 1434.71 1.60 70.3 1.48749
9 -51.87 1.50
10 16.18 0.83 29.4 1.95000
11 11.88 4.50 63.9 1.51680
12 -162.43 1.50
13 0.00 d13 開口絞りS
14 -60.18 1.50 52.77 1.74100
15 54.80 d15
16 135.21 1.50 56.2 1.52444
17* 168.80 0.50
18 -337.52 3.50 59.4 1.58313
19 -14.39 0.80 35.3 1.74950
20 -21.48 Bf

［レンズ群焦点距離］
レンズ群始面焦点距離
第１レンズ群 1 -27.23
第２レンズ群 8 28.21
第３レンズ群 14 -38.49
第４レンズ群 16 44.36 (Table 1)
[Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 18.50 to 45.00 to 53.40
FNO = 3.64 to 5.35 to 5.88
2ω = 78.1 to 35.0 to 29.7
TL = 122.38 to 119.93 to 124.96

[Lens data]
m r d νd nd
1 66.21 1.60 63.9 1.51680
2 15.70 0.17 38.1 1.55389
3 * 13.42 10.50
4 262.72 1.20 58.1 1.62299
5 21.53 1.10
6 21.37 4.40 28.4 1.72825
7 57.46 d7
8 1434.71 1.60 70.3 1.48749
9 -51.87 1.50
10 16.18 0.83 29.4 1.95000
11 11.88 4.50 63.9 1.51680
12 -162.43 1.50
13 0.00 d13 Aperture stop S
14 -60.18 1.50 52.77 1.74100
15 54.80 d15
16 135.21 1.50 56.2 1.52444
17 * 168.80 0.50
18 -337.52 3.50 59.4 1.58313
19 -14.39 0.80 35.3 1.74950
20 -21.48 Bf

[Lens focal length]
Lens group Start surface Focal length 1st lens group 1 -27.23
Second lens group 8 28.21
Third lens group 14 -38.49
Fourth lens group 16 44.36

この第１実施例において、第３面、及び、第１７面の各レンズ面は非球面形状に形成されている。次の表２に、非球面のデータ、すなわち頂点曲率半径Ｒ、円錐定数κ及び各非球面定数Ａ4〜Ａ10の値を示す。 In the first embodiment, the third and seventeenth lens surfaces are aspherical. The following Table 2 shows the data of aspheric surfaces, that is, the values of the vertex curvature radius R, the conic constant κ, and the aspheric constants A4 to A10.

（表２）
κ Ａ4 Ａ6 Ａ8 Ａ10
第 3面 -1.0 2.89951E-05 1.00217E-07 -2.55575E-10 1.58270E-12
第17面 -1.0 2.22627E-05 1.13930E-08 2.20954E-10 -3.78091E-12 (Table 2)
κ A4 A6 A8 A10
3rd surface -1.0 2.89951E-05 1.00217E-07 -2.55575E-10 1.58270E-12
17th surface -1.0 2.22627E-05 1.13930E-08 2.20954E-10 -3.78091E-12

この第１実施例において、第１レンズ群Ｇ１と第２レンズ群Ｇ２との軸上空気間隔ｄ７、第２レンズ群Ｇ２とともに移動する開口絞りＳと第３レンズ群Ｇ３との軸上空気間隔ｄ１３、第３レンズ群Ｇ３と第４レンズ群Ｇ４との軸上空気間隔ｄ１５、及び、バックフォーカスＢｆは、変倍に際して変化する。次の表３に、無限遠合焦時の広角端状態、中間焦点距離状態、及び、望遠端状態の各焦点距離における可変間隔及びバックフォーカスＢｆの値を示す。なお、バックフォーカスＢｆは、最も像側のレンズ面（図１における第２０面）から像面Ｉまでの光軸上の距離を表している。この説明は以降の実施例においても同様である。 In this first example, the axial air distance d7 between the first lens group G1 and the second lens group G2, and the axial air distance d13 between the aperture stop S moving with the second lens group G2 and the third lens group G3. The on-axis air distance d15 between the third lens group G3 and the fourth lens group G4 and the back focus Bf change during zooming. Table 3 below shows the values of the variable interval and the back focus Bf at each focal length in the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of focusing on infinity. Note that the back focus Bf represents the distance on the optical axis from the most image side lens surface (the 20th surface in FIG. 1) to the image surface I. This description is the same in the following embodiments.

（表３）
［可変間隔データ］
広角端中間焦点距離望遠端
ｆ 18.50 45.00 53.40
d7 35.325 5.896 3.068
d13 4.498 8.862 10.192
d15 7.548 2.891 1.561
Bf 38.600 65.580 73.437 (Table 3)
[Variable interval data]
Wide angle end Intermediate focal length Telephoto end f 18.50 45.00 53.40
d7 35.325 5.896 3.068
d13 4.498 8.862 10.192
d15 7.548 2.891 1.561
Bf 38.600 65.580 73.437

次の表４に、この第１実施例における各条件式対応値を示す。なおこの表４において、Ｒ１は第１レンズ群Ｇ１の最も物体側にある負レンズ（非球面正レンズＬ１１）の物体側面の曲率半径を、Ｒ２は第１レンズ群Ｇ１の最も物体側にある負レンズの像側面の曲率半径を、ｆ１は第１レンズ群Ｇ１の焦点距離を、ｆ２は第２レンズ群Ｇ２の焦点距離を、ｆ３は第３レンズ群Ｇ３の焦点距離を、ｆ４は第４レンズ群Ｇ４の焦点距離を、ｆ２ａは第２レンズ群Ｇ２における防振レンズ群ＶＬの焦点距離を、ｄ３ｗは広角端状態における第３レンズ群Ｇ３と第４レンズ群Ｇ４との空気間隔を、ｄＳｔは望遠端状態における開口絞りＳと第３レンズ群Ｇ３との空気間隔を、それぞれ表している。以上の符号の説明は以降の実施例においても同様である。 Table 4 below shows values corresponding to the conditional expressions in the first embodiment. In Table 4, R1 is the radius of curvature of the object side surface of the negative lens (aspheric positive lens L11) closest to the object side of the first lens group G1, and R2 is the negative radius closest to the object side of the first lens group G1. The radius of curvature of the image side surface of the lens, f1 is the focal length of the first lens group G1, f2 is the focal length of the second lens group G2, f3 is the focal length of the third lens group G3, and f4 is the fourth lens. The focal length of the group G4, f2a is the focal length of the anti-vibration lens group VL in the second lens group G2, d3w is the air gap between the third lens group G3 and the fourth lens group G4 in the wide-angle end state, and dSt is The air gap between the aperture stop S and the third lens group G3 in the telephoto end state is shown. The description of the above symbols is the same in the following embodiments.

（表４）
（１）(Ｒ２＋Ｒ１)／（Ｒ２−Ｒ１）＝-1.62
（２）ｆ４／ｄ３ｗ＝6.11
（３）ｆ１／ｆ３＝0.71
（４）ｄＳｔ／ｆ４＝0.23
（５）ｆ２／ｆ２ａ＝0.27 (Table 4)
(1) (R2 + R1) / (R2-R1) = -1.62
(2) f4 / d3w = 6.11
(3) f1 / f3 = 0.71
(4) dSt / f4 = 0.23
(5) f2 / f2a = 0.27

このように、この第１実施例に係る変倍光学系ＺＬ１は、上記条件式（１）〜（５）を全て満足している。 Thus, the variable magnification optical system ZL1 according to the first example satisfies all the conditional expressions (1) to (5).

この第１実施例の広角端状態での無限遠合焦状態の収差図を図２（ａ）に示し、中間焦点距離状態での無限遠合焦状態の収差図を図３に示し、望遠端状態での無限遠合焦状態の収差図を図４（ａ）に示す。また、第１実施例の広角端状態での無限遠合焦状態において像ぶれ補正（防振レンズ群ＶＬのシフト量＝0.28）を行ったときのコマ収差図を図２（ｂ）に示し、望遠端状態での無限遠合焦状態において像ぶれ補正（防振レンズ群ＶＬのシフト量＝0.29）を行った時のコマ収差図を図４（ｂ）に示す。各収差図において、ＦＮＯはＦナンバーを、Ｙは半画角に対する像高を、ｄはｄ線（λ＝５８７．６ｎｍ）を、ｇはｇ線（λ＝４３５．６ｎｍ）を、それぞれ示している。また、非点収差を示す収差図において実線はサジタル像面を示し、破線はメリディオナル像面を示している。この収差図の説明は以降の実施例においても同様である。各収差図から明らかなように、第１実施例では、広角端状態から望遠端状態までの各焦点距離状態において諸収差が良好に補正され、また手ぶれ補正時の収差変動も良好であり、優れた結像性能を有することがわかる。 FIG. 2A shows an aberration diagram in the infinite focus state in the wide-angle end state of the first embodiment, and FIG. 3 shows an aberration diagram in the infinite focus state in the intermediate focal length state. FIG. 4A shows an aberration diagram in the infinitely focused state in the state. FIG. 2B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group VL = 0.28) is performed in the infinite focus state at the wide-angle end state in the first embodiment. FIG. 4B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group VL = 0.29) is performed in the infinitely focused state at the telephoto end state. In each aberration diagram, FNO is an F number, Y is an image height with respect to a half angle of view, d is a d-line (λ = 587.6 nm), and g is a g-line (λ = 435.6 nm). Yes. In the aberration diagrams showing astigmatism, the solid line shows the sagittal image plane, and the broken line shows the meridional image plane. The explanation of this aberration diagram is the same in the following examples. As is apparent from the respective aberration diagrams, in the first embodiment, various aberrations are favorably corrected in each focal length state from the wide-angle end state to the telephoto end state, and aberration fluctuations at the time of camera shake correction are also excellent. It can be seen that the imaging performance is excellent.

〔第２実施例〕
図５は、第２実施例に係る変倍光学系ＺＬ２の構成を示す図である。この図５に示す変倍光学系ＺＬ２において、第１レンズ群Ｇ１は、物体側から順に、物体側に凸面を向けた負メニスカスレンズ形状の非球面負レンズＬ１１、両凹レンズＬ１２、及び、物体側に凸面を向けた正メニスカスレンズＬ１３から構成されている。ここで、非球面負レンズＬ１１は、像側のガラスレンズ面（第２面）に樹脂層を設け、その樹脂層の像側の面（第３面）が非球面形状に形成されている。第２レンズ群Ｇ２は、物体側から順に、両凸レンズＬ２１、及び、物体側に凸面を向けた負メニスカスレンズＬ２２と物体側に凸面を向けた正メニスカスレンズＬ２３との接合レンズから構成されている。第３レンズ群Ｇ３は、両凹レンズＬ３１から構成されている。第４レンズ群Ｇ４は、物体側から順に、両凸レンズ形状の非球面正レンズＬ４１、及び、両凸レンズＬ４２と物体側に凹面を向けた負メニスカスレンズＬ４３との接合レンズから構成されている。ここで、非球面正レンズＬ４１はその像側の面（第１７面）が非球面形状に形成されている。 [Second Embodiment]
FIG. 5 is a diagram showing a configuration of the variable magnification optical system ZL2 according to the second example. In the variable magnification optical system ZL2 shown in FIG. 5, the first lens group G1 includes, in order from the object side, a negative meniscus aspheric negative lens L11 having a convex surface facing the object side, a biconcave lens L12, and an object side. And a positive meniscus lens L13 having a convex surface. Here, in the aspheric negative lens L11, a resin layer is provided on the glass lens surface (second surface) on the image side, and the image side surface (third surface) of the resin layer is formed in an aspheric shape. The second lens group G2 includes, in order from the object side, a biconvex lens L21, and a cemented lens of a negative meniscus lens L22 having a convex surface facing the object side and a positive meniscus lens L23 having a convex surface facing the object side. . The third lens group G3 is composed of a biconcave lens L31. The fourth lens group G4 includes, in order from the object side, a biconvex aspherical positive lens L41, and a cemented lens of a biconvex lens L42 and a negative meniscus lens L43 having a concave surface facing the object. Here, the image-side surface (the 17th surface) of the aspherical positive lens L41 is formed in an aspherical shape.

また、像ぶれ補正（防振）は、第２レンズ群Ｇ２の両凸レンズＬ２１を防振レンズ群ＶＬとし、この防振レンズ群ＶＬを光軸と直交する方向の成分を含むように移動させることにより行う。この第２実施例の広角端状態においては、防振係数は０．８０であり、焦点距離は１８．５０（ｍｍ）であるので、０．４５°の回転ぶれを補正するための防振レンズ群ＶＬの移動量は０．１８（ｍｍ）である。また、この第２実施例の望遠端状態においては、防振係数は１．２７であり、焦点距離は５３．４０（ｍｍ）であるので、０．２６°の回転ぶれを補正するための防振レンズ群ＶＬの移動量は０．１９（ｍｍ）である。 In image blur correction (anti-shake), the biconvex lens L21 of the second lens group G2 is used as the anti-shake lens group VL, and the anti-shake lens group VL is moved so as to include a component in a direction perpendicular to the optical axis. To do. In the second embodiment, in the wide-angle end state, the image stabilization coefficient is 0.80 and the focal length is 18.50 (mm). Therefore, the image stabilization lens for correcting the rotation blur of 0.45 ° is used. The movement amount of the group VL is 0.18 (mm). In the telephoto end state of the second embodiment, the image stabilization coefficient is 1.27 and the focal length is 53.40 (mm). The moving amount of the vibration lens group VL is 0.19 (mm).

以下の表５に、この第２実施例の諸元の値を掲げる。なお、表５に示す面番号１〜２０は、図５に示す番号１〜２０に対応している。 Table 5 below shows values of specifications of the second embodiment. The surface numbers 1 to 20 shown in Table 5 correspond to the numbers 1 to 20 shown in FIG.

（表５）
［全体諸元］
広角端状態中間焦点距離状態望遠端状態
ｆ＝ 18.50 〜 45.00 〜 53.40
ＦＮＯ＝ 3.64 〜 5.35 〜 5.88
２ω ＝ 78.1 〜 35.5 〜 29.7
ＴＬ＝ 120.79 〜 114.99 〜 121.16

［レンズデータ］
ｍｒｄ νｄｎｄ
1 84.49 1.60 63.9 1.51680
2 15.40 0.17 38.2 1.55389
3* 13.42 11.50
4 -137.54 1.20 58.1 1.62299
5 51.74 1.20
6 30.42 3.50 27.6 1.75520
7 77.73 d7
8 52.97 1.60 82.6 1.49782
9 -84.25 1.50
10 18.26 0.83 29.4 1.95000
11 13.53 4.50 70.3 1.48749
12 1657.95 1.50
13 0.00 d13 開口絞りS
14 -92.69 1.50 52.2 1.51742
15 31.73 d15
16 374.19 1.50 56.4 1.52444
17* -215.67 0.50
18 28.47 6.00 58.8 1.51823
19 -32.76 0.80 34.9 1.80100
20 -103.60 Bf

［レンズ群焦点距離］
レンズ群始面焦点距離
第１レンズ群 1 -29.64
第２レンズ群 8 30.11
第３レンズ群 14 -45.50
第４レンズ群 16 47.38 (Table 5)
[Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 18.50 to 45.00 to 53.40
FNO = 3.64 to 5.35 to 5.88
2ω = 78.1 to 35.5 to 29.7
TL = 120.79-114.99-121.16

[Lens data]
m r d νd nd
1 84.49 1.60 63.9 1.51680
2 15.40 0.17 38.2 1.55389
3 * 13.42 11.50
4 -137.54 1.20 58.1 1.62299
5 51.74 1.20
6 30.42 3.50 27.6 1.75520
7 77.73 d7
8 52.97 1.60 82.6 1.49782
9 -84.25 1.50
10 18.26 0.83 29.4 1.95000
11 13.53 4.50 70.3 1.48749
12 1657.95 1.50
13 0.00 d13 Aperture stop S
14 -92.69 1.50 52.2 1.51742
15 31.73 d15
16 374.19 1.50 56.4 1.52444
17 * -215.67 0.50
18 28.47 6.00 58.8 1.51823
19 -32.76 0.80 34.9 1.80 100
20 -103.60 Bf

[Lens focal length]
Lens group Start surface Focal length 1st lens group 1 -29.64
Second lens group 8 30.11
Third lens group 14 -45.50
Fourth lens group 16 47.38

この第２実施例において、第３面、及び、第１７面の各レンズ面は非球面形状に形成されている。次の表６に、非球面のデータ、すなわち頂点曲率半径Ｒ、円錐定数κ及び各非球面定数Ａ4〜Ａ10の値を示す。 In the second embodiment, the third and seventeenth lens surfaces are aspherical. Table 6 below shows the aspheric data, that is, the values of the vertex curvature radius R, the conic constant κ, and the aspheric constants A4 to A10.

（表６）
κ Ａ4 Ａ6 Ａ8 Ａ10
第 3面 -1.0 3.22810E-05 9.22930E-08 -2.01905E-10 1.43420E-12
第17面 -1.0 1.93725E-05 3.05794E-08 1.79558E-10 -2.62590E-13 (Table 6)
κ A4 A6 A8 A10
3rd surface -1.0 3.22810E-05 9.22930E-08 -2.01905E-10 1.43420E-12
17th surface -1.0 1.93725E-05 3.05794E-08 1.79558E-10 -2.62590E-13

この第２実施例において、第１レンズ群Ｇ１と第２レンズ群Ｇ２との軸上空気間隔ｄ７、第２レンズ群Ｇ２とともに移動する開口絞りＳと第３レンズ群Ｇ３との軸上空気間隔ｄ１３、第３レンズ群Ｇ３と第４レンズ群Ｇ４との軸上空気間隔ｄ１５、及び、バックフォーカスＢｆは、変倍に際して変化する。次の表７に、無限遠合焦時の広角端状態、中間焦点距離状態、及び、望遠端状態の各焦点距離における可変間隔及びバックフォーカスＢｆの値を示す。 In the second embodiment, the axial air distance d7 between the first lens group G1 and the second lens group G2, and the axial air distance d13 between the aperture stop S moving with the second lens group G2 and the third lens group G3. The on-axis air distance d15 between the third lens group G3 and the fourth lens group G4 and the back focus Bf change during zooming. Table 7 below shows the values of the variable interval and the back focus Bf at the respective focal lengths in the wide-angle end state, the intermediate focal length state, and the telephoto end state when focusing on infinity.

（表７）
［可変間隔データ]
広角端中間焦点距離望遠端
ｆ 18.50 45.0 53.4
d7 39.110 4.869 1.288
d13 13.462 15.786 15.803
d15 8.812 5.411 5.368
Bf 20.000 49.520 59.299 (Table 7)
[Variable interval data]
Wide angle end Intermediate focal length Telephoto end f 18.50 45.0 53.4
d7 39.110 4.869 1.288
d13 13.462 15.786 15.803
d15 8.812 5.411 5.368
Bf 20.000 49.520 59.299

次の表８に、この第２実施例における各条件式対応値を示す。 Table 8 below shows values corresponding to the conditional expressions in the second embodiment.

（表８）
（１）(Ｒ２＋Ｒ１)/（Ｒ２−Ｒ１）＝-1.45
（２）ｆ４／ｄ３ｗ＝5.38
（３）ｆ１／ｆ３＝0.65
（４）ｄＳｔ／ｆ４＝0.33
（５）ｆ２／ｆ２ａ＝0.46 (Table 8)
(1) (R2 + R1) / (R2-R1) = -1.45
(2) f4 / d3w = 5.38
(3) f1 / f3 = 0.65
(4) dSt / f4 = 0.33
(5) f2 / f2a = 0.46

このように、この第２実施例に係る変倍光学系ＺＬ２は、上記条件式（１）〜（５）を全て満足している。 Thus, the zoom optical system ZL2 according to the second example satisfies all the conditional expressions (1) to (5).

この第２実施例の広角端状態での無限遠合焦状態の収差図を図６（ａ）に示し、中間焦点距離状態での無限遠合焦状態の収差図を図７に示し、望遠端状態での無限遠合焦状態の収差図を図８（ａ）に示す。また、第２実施例の広角端状態での無限遠合焦状態において像ぶれ補正（防振レンズ群ＶＬのシフト量＝0.18）を行ったときのコマ収差図を図６（ｂ）に示し、望遠端状態での無限遠合焦状態において像ぶれ補正（防振レンズ群ＶＬのシフト量＝0.19）を行ったときのコマ収差図を図８（ｂ）に示す。各収差図から明らかなように、第２実施例では、広角端状態から望遠端状態までの各焦点距離状態において諸収差が良好に補正され、また手ぶれ補正時の収差変動も良好であり、優れた結像性能を有することがわかる。 FIG. 6A shows an aberration diagram in the infinite focus state in the wide-angle end state of this second embodiment, and FIG. 7 shows an aberration diagram in the infinite focus state in the intermediate focal length state. FIG. 8A shows an aberration diagram in the infinitely focused state in the state. FIG. 6B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group VL = 0.18) is performed in the infinite focus state at the wide-angle end state in the second embodiment. FIG. 8B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group VL = 0.19) is performed in the infinitely focused state at the telephoto end state. As is apparent from the respective aberration diagrams, in the second embodiment, various aberrations are favorably corrected in each focal length state from the wide-angle end state to the telephoto end state, and aberration fluctuations at the time of camera shake correction are also excellent. It can be seen that the imaging performance is excellent.

〔第３実施例〕
図９は、第３実施例に係る変倍光学系ＺＬ３の構成を示す図である。この図９に示す変倍光学系ＺＬ３において、第１レンズ群Ｇ１は、物体側から順に、物体側に凸面を向けた負メニスカスレンズ形状の非球面負レンズＬ１１、両凹レンズＬ１２、及び、物体側に凸面を向けた正メニスカスレンズＬ１３から構成されている。ここで、非球面負レンズＬ１１は、像側のガラスレンズ面（第２面）に樹脂層を設け、その樹脂層の像側の面（第３面）が非球面形状に形成されている。第２レンズ群Ｇ２は、物体側から順に、両凸レンズＬ２１、及び、物体側に凸面を向けた負メニスカスレンズＬ２２と物体側に凸面を向けた正メニスカスレンズＬ２３との接合レンズから構成されている。第３レンズ群Ｇ３は、両凹レンズＬ３１から構成されている。第４レンズ群Ｇ４は、物体側から順に、物体側に凸面を向けた正メニスカスレンズ形状の非球面正レンズＬ４１、及び、両凸レンズＬ４２と物体側に凹面を向けた負メニスカスレンズＬ４３との接合レンズから構成されている。ここで、非球面正レンズＬ４１はその像側の面（第１７面）が非球面形状に形成されている。 [Third embodiment]
FIG. 9 is a diagram illustrating a configuration of the variable magnification optical system ZL3 according to the third example. In the zoom optical system ZL3 shown in FIG. 9, the first lens group G1 includes, in order from the object side, a negative meniscus aspheric negative lens L11 having a convex surface facing the object side, a biconcave lens L12, and an object side. And a positive meniscus lens L13 having a convex surface. Here, in the aspheric negative lens L11, a resin layer is provided on the glass lens surface (second surface) on the image side, and the image side surface (third surface) of the resin layer is formed in an aspheric shape. The second lens group G2 includes, in order from the object side, a biconvex lens L21, and a cemented lens of a negative meniscus lens L22 having a convex surface facing the object side and a positive meniscus lens L23 having a convex surface facing the object side. . The third lens group G3 is composed of a biconcave lens L31. The fourth lens group G4 includes, in order from the object side, a positive meniscus aspheric lens L41 having a convex surface facing the object side, and a biconvex lens L42 and a negative meniscus lens L43 having a concave surface facing the object side. It consists of a lens. Here, the image-side surface (the 17th surface) of the aspherical positive lens L41 is formed in an aspherical shape.

また、開口絞りＳは、第２レンズ群Ｇ２の両凸レンズＬ２１と負メニスカスレンズＬ２２との間に位置し、広角端状態から望遠端状態への変倍に際して第２レンズ群Ｇ２とともに移動する。また、無限遠から近距離物体への合焦は、第１レンズ群Ｇ１を物体方向に繰り出す（移動させる）ことにより行う。 The aperture stop S is located between the biconvex lens L21 and the negative meniscus lens L22 of the second lens group G2, and moves together with the second lens group G2 upon zooming from the wide-angle end state to the telephoto end state. Further, focusing from infinity to a close object is performed by extending (moving) the first lens group G1 in the object direction.

また、像ぶれ補正（防振）は、第２レンズ群Ｇ２の両凸レンズＬ２１を防振レンズ群ＶＬとし、この防振レンズ群ＶＬを光軸と直交する方向の成分を含むように移動させることにより行う。この第３実施例の広角端状態においては、防振係数は０．５６であり、焦点距離は１８．０３（ｍｍ）であるので、０．４５°の回転ぶれを補正するための防振レンズ群ＶＬの移動量は０．２５（ｍｍ）である。また、この第３実施例の望遠端状態においては、防振係数は０．９２であり、焦点距離は５３．６３（ｍｍ）であるので、０．２６°の回転ぶれを補正するための防振レンズ群ＶＬの移動量は０．２６（ｍｍ）である。 In image blur correction (anti-shake), the biconvex lens L21 of the second lens group G2 is used as the anti-shake lens group VL, and the anti-shake lens group VL is moved so as to include a component in a direction perpendicular to the optical axis. To do. In the third embodiment, in the wide-angle end state, the image stabilization coefficient is 0.56 and the focal length is 18.03 (mm). Therefore, the image stabilization lens for correcting the rotation blur of 0.45 ° is used. The movement amount of the group VL is 0.25 (mm). In the telephoto end state of the third embodiment, the image stabilization coefficient is 0.92, and the focal length is 53.63 (mm). The moving amount of the vibration lens group VL is 0.26 (mm).

以下の表９に、この第３実施例の諸元の値を掲げる。なお、表９に示す面番号１〜２０は、図９に示す面番号１〜２０に対応している。 Table 9 below shows values of specifications of the third embodiment. The surface numbers 1 to 20 shown in Table 9 correspond to the surface numbers 1 to 20 shown in FIG.

（表９）
[全体諸元]
広角端状態中間焦点距離状態望遠端状態
ｆ＝ 18.03 〜 43.66 〜 53.63
ＦＮＯ＝ 3.63 〜 4.10 〜 5.78
２ω ＝ 79.4 〜 63.3 〜 29.7
ＴＬ＝ 127.57 〜 125.30 〜 132.98

［レンズデータ］
ｍｒｄ νｄｎｄ
1 66.53 1.60 63.9 1.51680
2 15.30 0.17 38.2 1.55389
3* 12.92 10.54
4 -4417.66 1.40 58.1 1.62299
5 27.61 2.07
6 26.72 3.05 28.4 1.72825
7 74.43 d7
8 86.65 2.30 63.9 1.51680
9 -105.78 1.01
10 0.00 0.18 開口絞りS
11 19.59 2.61 25.4 1.80518
12 12.86 3.91 52.3 1.51742
13 -266.13 d13
14 -131.20 2.05 52.8 1.74100
15 47.96 d15
16 86.82 1.73 56.4 1.52444
17* 298.28 1.07
18 1340.85 4.44 52.3 1.51742
19 -14.96 1.46 25.4 1.80518
20 -21.92 Bf

［レンズ群焦点距離］
レンズ群始面焦点距離
第１レンズ群 1 -26.64
第２レンズ群 8 30.89
第３レンズ群 14 -47.17
第４レンズ群 16 45.15 (Table 9)
[Overall specifications]
Wide-angle end state Intermediate focal length state Telephoto end state f = 18.03 to 43.66 to 53.63
FNO = 3.63 to 4.10 to 5.78
2ω = 79.4 to 63.3 to 29.7
TL = 127.57 to 125.30 to 132.98

[Lens data]
m r d νd nd
1 66.53 1.60 63.9 1.51680
2 15.30 0.17 38.2 1.55389
3 * 12.92 10.54
4 -4417.66 1.40 58.1 1.62299
5 27.61 2.07
6 26.72 3.05 28.4 1.72825
7 74.43 d7
8 86.65 2.30 63.9 1.51680
9 -105.78 1.01
10 0.00 0.18 Aperture stop S
11 19.59 2.61 25.4 1.80518
12 12.86 3.91 52.3 1.51742
13 -266.13 d13
14 -131.20 2.05 52.8 1.74100
15 47.96 d15
16 86.82 1.73 56.4 1.52444
17 * 298.28 1.07
18 1340.85 4.44 52.3 1.51742
19 -14.96 1.46 25.4 1.80518
20 -21.92 Bf

[Lens focal length]
Lens group Start surface Focal length 1st lens group 1 -26.64
Second lens group 8 30.89
Third lens group 14 -47.17
Fourth lens group 16 45.15

この第３実施例において、第３面、及び、第１７面の各レンズ面は非球面形状に形成されている。次の表１０に、非球面のデータ、すなわち頂点曲率半径Ｒ、円錐定数κ及び各非球面定数Ａ4〜Ａ10の値を示す。 In the third embodiment, the third and seventeenth lens surfaces are aspherical. Table 10 below shows the data of the aspheric surface, that is, the values of the vertex curvature radius R, the conic constant κ, and the aspheric constants A4 to A10.

（表１０）
κ Ａ4 Ａ6 Ａ8 Ａ10
第 3面 -1.0 3.11022E-05 7.96306E-08 -1.01842E-10 1.04228E-12
第17面 -1.0 1.59804E-05 -4.88413E-08 1.46203E-09 -1.17341E-11 (Table 10)
κ A4 A6 A8 A10
3rd surface -1.0 3.11022E-05 7.96306E-08 -1.01842E-10 1.04228E-12
17th surface -1.0 1.59804E-05 -4.88413E-08 1.46203E-09 -1.17341E-11

この第３実施例において、第１レンズ群Ｇ１と第２レンズ群Ｇ２との軸上空気間隔ｄ７、第２レンズ群Ｇ２と第３レンズ群Ｇ３との軸上空気間隔ｄ１３、第３レンズ群Ｇ３と第４レンズ群Ｇ４との軸上空気間隔ｄ１５、及び、バックフォーカスＢｆは、変倍に際して変化する。次の表１１に、無限遠合焦時の広角端状態、中間焦点距離状態、及び、望遠端状態の各焦点距離における可変間隔及びバックフォーカスの値を示す。 In the third embodiment, the axial air distance d7 between the first lens group G1 and the second lens group G2, the axial air distance d13 between the second lens group G2 and the third lens group G3, and the third lens group G3. The on-axis air distance d15 between the first lens group G4 and the fourth lens group G4 and the back focus Bf change during zooming. Table 11 below shows the values of the variable interval and the back focus at each focal length in the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of focusing on infinity.

（表１１）
［可変間隔データ］
広角端中間焦点距離望遠端
ｆ 18.03 43.66 53.63
d7 34.649 4.502 0.909
d13 4.001 10.088 2.744
d15 10.297 4.119 2.744
Bf 37.161 65.048 73.106 (Table 11)
[Variable interval data]
Wide angle end Intermediate focal length Telephoto end f 18.03 43.66 53.63
d7 34.649 4.502 0.909
d13 4.001 10.088 2.744
d15 10.297 4.119 2.744
Bf 37.161 65.048 73.106

次の表１２に、この第３実施例における各条件式対応値を示す。 Table 12 below shows values corresponding to the conditional expressions in the third embodiment.

（表１２）
（１）(Ｒ２＋Ｒ１)/（Ｒ２−Ｒ１）＝-1.60
（２）ｆ４／ｄ３ｗ＝4.38
（３）ｆ１／ｆ３＝0.56
（４）ｄＳｔ／ｆ４＝0.38
（５）ｆ２／ｆ２ａ＝0.33 (Table 12)
(1) (R2 + R1) / (R2-R1) = -1.60
(2) f4 / d3w = 4.38
(3) f1 / f3 = 0.56
(4) dSt / f4 = 0.38
(5) f2 / f2a = 0.33

このように、この第３実施例に係る変倍光学系ＺＬ３は、上記条件式（１）〜（５）を全て満足している。 Thus, the variable magnification optical system ZL3 according to the third example satisfies all the conditional expressions (1) to (5).

この第３実施例の広角端状態での無限遠合焦状態の収差図を図１０（ａ）に示し、中間焦点距離状態での無限遠合焦状態の収差図を図１１に示し、望遠端状態での無限遠合焦状態の収差図を図１２（ａ）に示す。また、第３実施例の広角端状態での無限遠合焦状態において像ぶれ補正（防振レンズ群ＶＬのシフト量＝0.25）を行ったときのコマ収差図を図１０（ｂ）に示し、望遠端状態での無限遠合焦状態において像ぶれ補正（防振レンズ群ＶＬのシフト量＝0.26）を行ったときのコマ収差図を図１２（ｂ）に示す。各収差図から明らかなように、第３実施例では、広角端状態から望遠端状態までの各焦点距離状態において諸収差が良好に補正され、また手ぶれ補正時の収差変動も良好であり、優れた結像性能を有することがわかる。 FIG. 10A shows an aberration diagram in the infinite focus state in the wide-angle end state of the third embodiment, and FIG. 11 shows an aberration diagram in the infinite focus state in the intermediate focal length state. FIG. 12A shows an aberration diagram in the infinitely focused state in the state. FIG. 10B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group VL = 0.25) is performed in the infinite focus state at the wide-angle end state in the third example. FIG. 12B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group VL = 0.26) is performed in the infinitely focused state at the telephoto end state. As is apparent from the respective aberration diagrams, in the third example, various aberrations are favorably corrected in each focal length state from the wide-angle end state to the telephoto end state, and aberration fluctuations at the time of camera shake correction are also excellent. It can be seen that the imaging performance is excellent.

〔第４実施例〕
図１３は、本願の第４実施例に係る変倍光学系ＺＬ４の構成を示す図である。この図１３の変倍光学系ＺＬ４において、第１レンズ群Ｇ１は、物体側から順に、物体側に凸面を向けた負メニスカスレンズ形状の非球面負レンズＬ１１、両凹レンズＬ１２、及び、物体側に凸面を向けた正メニスカスレンズＬ１３から構成されている。ここで、非球面負レンズＬ１１は、像側のガラスレンズ面（第２面）に樹脂層を設け、その樹脂層の像側の面（第３面）が非球面形状に形成されている。第２レンズ群Ｇ２は、物体側から順に、両凸レンズＬ２１、物体側に凸面を向けた負メニスカスレンズＬ２２と物体側に凸面を向けた正メニスカスレンズＬ２３との接合レンズ、及び、物体側に凸面を向けた正メニスカスレンズＬ２４から構成されている。第３レンズ群Ｇ３は、両凹レンズＬ３１から構成されている。第４レンズ群Ｇ４は、物体側から順に、両凹レンズ形状の非球面負レンズＬ４１、及び、両凸レンズＬ４２と物体側に凹面を向けた負メニスカスレンズＬ４３との接合レンズから構成されている。ここで、非球面負レンズＬ４１はその像側の面（第１９面）が非球面形状に形成されている。 [Fourth embodiment]
FIG. 13 is a diagram showing a configuration of a variable magnification optical system ZL4 according to the fourth example of the present application. In the variable magnification optical system ZL4 in FIG. 13, the first lens group G1 includes, in order from the object side, a negative meniscus aspheric negative lens L11 having a convex surface facing the object side, a biconcave lens L12, and an object side. It is composed of a positive meniscus lens L13 having a convex surface. Here, in the aspheric negative lens L11, a resin layer is provided on the glass lens surface (second surface) on the image side, and the image side surface (third surface) of the resin layer is formed in an aspheric shape. The second lens group G2 includes, in order from the object side, a biconvex lens L21, a cemented lens of a negative meniscus lens L22 having a convex surface facing the object side and a positive meniscus lens L23 having a convex surface facing the object side, and a convex surface facing the object side. Is formed from a positive meniscus lens L24. The third lens group G3 is composed of a biconcave lens L31. The fourth lens group G4 includes, in order from the object side, a biconcave lens-shaped aspheric negative lens L41 and a cemented lens of a biconvex lens L42 and a negative meniscus lens L43 having a concave surface facing the object. Here, the image-side surface (19th surface) of the aspheric negative lens L41 is formed in an aspheric shape.

また、像ぶれ補正（防振）は、第２レンズ群Ｇ２の両凸レンズＬ２１を防振レンズ群ＶＬとし、この防振レンズ群ＶＬを光軸と直交する方向の成分を含むように移動させることにより行う。この第４実施例の広角端状態においては、防振係数は０．５４であり、焦点距離は１８．５３（ｍｍ）であるので、０．４４°の回転ぶれを補正するための防振レンズ群ＶＬの移動量は０．２７（ｍｍ）である。また、この第４実施例の望遠端状態においては、防振係数は０．８６であり、焦点距離は５３．７１（ｍｍ）であるので、０．２６°の回転ぶれを補正するための防振レンズ群ＶＬの移動量は０．２８（ｍｍ）である。 In image blur correction (anti-shake), the biconvex lens L21 of the second lens group G2 is used as the anti-shake lens group VL, and the anti-shake lens group VL is moved so as to include a component in a direction perpendicular to the optical axis. To do. In the fourth embodiment, in the wide-angle end state, the image stabilization coefficient is 0.54 and the focal length is 18.53 (mm). Therefore, the image stabilization lens for correcting the rotation blur of 0.44 ° is used. The movement amount of the group VL is 0.27 (mm). In the telephoto end state of the fourth embodiment, the image stabilization coefficient is 0.86 and the focal length is 53.71 (mm). The moving amount of the vibration lens group VL is 0.28 (mm).

以下の表１３に、この第４実施例の諸元の値を掲げる。なお、表１３に示す面番号１〜２２は、図１３に示す番号１〜２２に対応している。 Table 13 below lists values of specifications of the fourth embodiment. The surface numbers 1 to 22 shown in Table 13 correspond to the numbers 1 to 22 shown in FIG.

（表１３）
広角端状態中間焦点距離状態望遠端状態
ｆ＝ 18.53 〜 43.38 〜 53.71
ＦＮＯ＝ 3.47 〜 5.24 〜 6.12
２ω ＝ 78.0 〜 36.4 〜 29.7
ＴＬ＝ 127.58 〜 127.55 〜 135.41

［レンズデータ］
ｍｒｄ νｄｎｄ
1 58.81 1.60 63.9 1.51680
2 15.85 0.17 38.2 1.55389
3* 13.48 9.44
4 -180.66 1.39 58.1 1.62299
5 26.02 1.49
6 26.67 3.49 28.4 1.72825
7 94.09 d7
8 312.58 2.29 63.9 1.51680
9 -58.78 1.49
10 21.84 3.08 23.8 1.84666
11 14.16 2.73 52.2 1.51742
12 33.66 4.05
13 19.49 2.80 52.2 1.51742
14 316.42 1.03
15 0.00 d15 開口絞りS
16 -6000.00 1.60 52.8 1.74100
17 29.14 d17
18 -81.46 1.39 56.4 1.52444
19* 182.48 0.21
20 43.32 5.37 63.9 1.51680
21 -14.00 1.21 35.3 1.74950
22 -20.86 Bf

［レンズ群焦点距離］
レンズ群始面焦点距離
第１レンズ群 1 -26.23
第２レンズ群 8 29.14
第３レンズ群 16 -39.13
第４レンズ群 18 44.82 (Table 13)
Wide-angle end state Intermediate focal length state Telephoto end state f = 18.53 to 43.38 to 53.71
FNO = 3.47 to 5.24 to 6.12
2ω = 78.0 to 36.4 to 29.7
TL = 127.58 to 127.55 to 135.41

[Lens data]
m r d νd nd
1 58.81 1.60 63.9 1.51680
2 15.85 0.17 38.2 1.55389
3 * 13.48 9.44
4 -180.66 1.39 58.1 1.62299
5 26.02 1.49
6 26.67 3.49 28.4 1.72825
7 94.09 d7
8 312.58 2.29 63.9 1.51680
9 -58.78 1.49
10 21.84 3.08 23.8 1.84666
11 14.16 2.73 52.2 1.51742
12 33.66 4.05
13 19.49 2.80 52.2 1.51742
14 316.42 1.03
15 0.00 d15 Aperture stop S
16 -6000.00 1.60 52.8 1.74100
17 29.14 d17
18 -81.46 1.39 56.4 1.52444
19 * 182.48 0.21
20 43.32 5.37 63.9 1.51680
21 -14.00 1.21 35.3 1.74950
22 -20.86 Bf

[Lens focal length]
Lens group Start surface Focal length 1st lens group 1 -26.23
Second lens group 8 29.14
Third lens group 16 -39.13
Fourth lens group 18 44.82

この第４実施例において、第３面、及び、第１９面の各レンズ面は非球面形状に形成されている。次の表１４に、非球面のデータ、すなわち頂点曲率半径Ｒ、円錐定数κ及び各非球面定数Ａ4〜Ａ10の値を示す。 In the fourth embodiment, the third and nineteenth lens surfaces are aspherical. Table 14 below shows the data of aspheric surfaces, that is, the values of the vertex curvature radius R, the conic constant κ, and the aspheric constants A4 to A10.

（表１４）
κ Ａ4 Ａ6 Ａ8 Ａ10
第 3面 -1.0 2.74278E-05 7.96306E-08 -1.01842E-10 1.04228E-12
第19面 -1.0 2.60580E-05 3.23416E-09 1.06234E-09 -9.17414E-12 (Table 14)
κ A4 A6 A8 A10
3rd surface -1.0 2.74278E-05 7.96306E-08 -1.01842E-10 1.04228E-12
19th surface -1.0 2.60580E-05 3.23416E-09 1.06234E-09 -9.17414E-12

この第４実施例において、第１レンズ群Ｇ１と第２レンズ群Ｇ２との軸上空気間隔ｄ７、第２レンズ群Ｇ２とともに移動する開口絞りＳと第３レンズ群Ｇ３との軸上空気間隔ｄ１５、第３レンズ群Ｇ３と第４レンズ群Ｇ４との軸上空気間隔ｄ１７、及び、バックフォーカスＢｆは、変倍に際して変化する。次の表１５に、無限遠合焦時の広角端状態、中間焦点距離状態、及び、望遠端状態の各焦点距離における可変間隔及びバックフォーカスの値を示す。 In the fourth embodiment, the axial air distance d7 between the first lens group G1 and the second lens group G2, and the axial air distance d15 between the aperture stop S moving with the second lens group G2 and the third lens group G3. The on-axis air distance d17 between the third lens group G3 and the fourth lens group G4 and the back focus Bf change during zooming. Table 15 below shows the values of the variable interval and the back focus at each focal length in the wide-angle end state, the intermediate focal length state, and the telephoto end state at the time of focusing on infinity.

（表１５）
広角端中間焦点距離望遠端
ｆ 18.53 43.38 53.71
d7 33.970 4.901 1.207
d15 2.413 5.616 6.346
d17 7.546 3.804 2.432
Bf 38.814 68.397 80.595 (Table 15)
Wide angle end Intermediate focal length Telephoto end f 18.53 43.38 53.71
d7 33.970 4.901 1.207
d15 2.413 5.616 6.346
d17 7.546 3.804 2.432
Bf 38.814 68.397 80.595

次の表１６に、この第４実施例における各条件式対応値を示す。 Table 16 below shows values corresponding to the conditional expressions in the fourth embodiment.

（表１６）
（１）(Ｒ２＋Ｒ１)/（Ｒ２−Ｒ１）＝-1.74
（２）ｆ４／ｄ３ｗ＝5.94
（３）ｆ１／ｆ３＝0.67
（４）ｄＳｔ／ｆ４＝0.17
（５）ｆ２／ｆ２ａ＝0.30 (Table 16)
(1) (R2 + R1) / (R2-R1) = -1.74
(2) f4 / d3w = 5.94
(3) f1 / f3 = 0.67
(4) dSt / f4 = 0.17
(5) f2 / f2a = 0.30

このように、この第４実施例に係る変倍光学系ＺＬ４は、上記条件式（１）〜（５）を全て満足している。 Thus, the zoom optical system ZL4 according to the fourth example satisfies all the conditional expressions (1) to (5).

この第４実施例の広角端状態での無限遠合焦状態の収差図を図１４（ａ）に示し、中間焦点距離状態での無限遠合焦状態の収差図を図１５に示し、望遠端状態での無限遠合焦状態の収差図を図１６（ａ）に示す。また、第４実施例の広角端状態での無限遠合焦状態において像ぶれ補正（防振レンズ群ＶＬのシフト量＝0.27）を行ったときのコマ収差図を図１４（ｂ）に示し、望遠端状態での無限遠合焦状態において像ぶれ補正（防振レンズ群ＶＬのシフト量＝0.28）を行った時のコマ収差図を図１６（ｂ）に示す。各収差図から明らかなように、第４実施例では、広角端状態から望遠端状態までの各焦点距離状態において諸収差が良好に補正され、また手ぶれ補正時の収差変動も良好であり、優れた結像性能を有することがわかる。 FIG. 14A shows an aberration diagram in the infinite focus state in the wide-angle end state of the fourth embodiment, and FIG. 15 shows an aberration diagram in the infinite focus state in the intermediate focal length state. FIG. 16A shows an aberration diagram in the infinitely focused state in the state. FIG. 14B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens unit VL = 0.27) is performed in the infinitely focused state at the wide-angle end state in the fourth example. FIG. 16B shows a coma aberration diagram when image blur correction (shift amount of the image stabilizing lens group VL = 0.28) is performed in the infinitely focused state at the telephoto end state. As is apparent from the respective aberration diagrams, in the fourth example, various aberrations are satisfactorily corrected in each focal length state from the wide-angle end state to the telephoto end state, and aberration fluctuation at the time of camera shake correction is also excellent. It can be seen that the imaging performance is excellent.

ＺＬ（ＺＬ１〜ＺＬ４）変倍光学系
Ｇ１第１レンズ群Ｇ２第２レンズ群Ｇ３第３レンズ群
Ｇ４第４レンズ群Ｓ開口絞り
１カメラ（光学装置） ZL (ZL1 to ZL4) Variable magnification optical system G1 First lens group G2 Second lens group G3 Third lens group G4 Fourth lens group S Aperture stop 1 Camera (optical device)

Claims

From the object side,
A first lens group having negative refractive power;
A second lens group having a positive refractive power;
A third lens group having negative refractive power;
A fourth lens group having a positive refractive power,
When zooming from the wide-angle end state to the telephoto end state, the distance between the first lens group and the second lens group changes, and the distance between the second lens group and the third lens group changes, The distance between the third lens group and the fourth lens group changes,
At least one single lens of the second lens group is an anti-vibration lens group that moves so as to include a component in a direction orthogonal to the optical axis,
The first lens group has a negative lens closest to the object side,
A variable magnification optical system characterized by satisfying the following condition:
−2.00 <(R2 + R1) / (R2−R1) <− 1.00
However,
R1: radius of curvature of the object side surface of the negative lens closest to the object side of the first lens group R2: radius of curvature of the image side surface of the negative lens closest to the object side of the first lens group

The third lens group has at least one single lens having an air gap on both sides,
2. The variable magnification optical system according to claim 1, wherein a condition of the following formula is satisfied.
3.00 <f4 / d3w <9.00
However,
f4: Focal length of the fourth lens group d3w: Air distance between the third lens group and the fourth lens group in the wide-angle end state

3. The variable magnification optical system according to claim 1, wherein a condition of the following formula is satisfied.
0.40 <f1 / f3 <1.00
However,
f1: Focal length of the first lens group f3: Focal length of the third lens group

An aperture stop in or near the second lens group;
The fourth lens group includes a cemented lens in which a positive lens and a negative lens are bonded to the most image side,
The zoom lens system according to any one of claims 1 to 3, wherein a condition of the following formula is satisfied.
0.10 <dSt / f4 <0.60
However,
dSt: Air distance between the aperture stop and the third lens group in the telephoto end state f4: Focal length of the fourth lens group

5. The variable magnification optical system according to claim 1, wherein a lens closest to the object side in the first lens group has an aspherical surface.

The zoom lens system according to any one of claims 1 to 5, wherein a condition of the following formula is satisfied.
0.10 <f2 / f2a <0.55
However,
f2: focal length of the second lens group f2a: focal length of the anti-vibration lens group

The variable magnification optical system according to claim 1, wherein the third lens group includes only a single lens.

The variable power optical system according to claim 7, wherein the single lens has a biconcave shape.

The variable power optical system according to any one of claims 1 to 8, wherein the fourth lens group has at least one aspherical surface.

10. The variable magnification optical system according to claim 9, wherein the lens having the aspheric surface included in the fourth lens group is positioned closest to the object side of the fourth lens group.

The variable power optical system according to claim 1, wherein at least one of the cemented lenses included in the fourth lens group has a cemented surface convex toward the image side. .

When zooming from the wide-angle end state to the telephoto end state, the distance between the second lens group and the third lens group increases, and the distance between the third lens group and the fourth lens group decreases. The variable power optical system according to any one of claims 1 to 11, wherein:

An optical apparatus comprising the variable magnification optical system according to claim 1, wherein an image of an object is formed on a predetermined image plane.

In order from the object side, 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, and a fourth lens having a positive refractive power A variable magnification optical system having a group,
When the first lens group, the second lens group, the third lens group, and the fourth lens group are zoomed from the wide-angle end state to the telephoto end state, the first lens group and the second lens group And the distance between the second lens group and the third lens group is changed, and the distance between the third lens group and the fourth lens group is changed,
Arranging at least one single lens of the second lens group as an anti-vibration lens group that moves so as to include a component in a direction orthogonal to the optical axis,
A method of manufacturing a variable magnification optical system, comprising disposing a negative lens that satisfies the following condition on the most object side of the first lens group.
−2.00 <(R2 + R1) / (R2−R1) <− 1.00
However,
R1: radius of curvature of the object side surface of the negative lens closest to the object side of the first lens group R2: radius of curvature of the image side surface of the negative lens closest to the object side of the first lens group