JP2011248266A

JP2011248266A - Zoom lens

Info

Publication number: JP2011248266A
Application number: JP2010123903A
Authority: JP
Inventors: Masae Sato; 正江佐藤
Original assignee: Konica Minolta Opto Inc
Current assignee: Konica Minolta Opto Inc
Priority date: 2010-05-31
Filing date: 2010-05-31
Publication date: 2011-12-08

Abstract

PROBLEM TO BE SOLVED: To provide a zoom lens which is easy to assemble and compact, and has a wide viewing angle and a high variable power ratio, and whose aberration is satisfactorily corrected.SOLUTION: The zoom lens includes: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; a fourth lens group having positive refractive power, and the movement of the four lens group varies power. The first lens group includes a negative lens and a positive lens. The second lens group includes a negative lens, a negative lens and positive lens. The third lens group includes a third a lens group having one positive lens and a third b lens group having a three-piece cemented lens having a positive lens, a negative lens and a positive lens. And, the following conditional expressions are satisfied; 0.1<n3b2-n3b1<0.7,0.1<n3b2-n3b3<0.7 where: n3b1 denotes the refractive power of the lens nearest to the object side in the third b lens group, corresponding to d-rays; n3b2 denotes the refractive power of the lens in the middle of the third b lens group, corresponding to d-rays; and n3b3 denotes the refractive power of the lens nearest to the image side in the third b lens group, corresponding to d-rays.

Description

本発明は、ＣＣＤ（電荷結合素子）やＣＭＯＳ（相補型金属酸化物半導体）を用いたデジタルスチルカメラやビデオカメラ等に好適で、１０倍程度の変倍比を有し、広角端の画角が７５°以上であるコンパクトなズームレンズに関する。 The present invention is suitable for a digital still camera or a video camera using a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), has a zoom ratio of about 10 times, and has a wide angle end angle of view. The present invention relates to a compact zoom lens having 75 ° or more.

ＣＣＤやＣＭＯＳを用いたデジタルスチルカメラやビデオカメラにおいては、コンパクト、高変倍及び広画角であって、更に生産性の良いズームレンズの需要が高まっている。これらを満たすズームレンズとして、高変倍に適した正群先行タイプのズームレンズにおいて、各群に接合レンズを使用して構成要素を少なくし、誤差の低減を図ったズームレンズが種々の特許公報に開示されている（特許文献１〜４参照）。 In digital still cameras and video cameras using CCDs and CMOSs, there is an increasing demand for zoom lenses that are compact, have a high zoom ratio and a wide angle of view, and are more productive. As a zoom lens that satisfies these requirements, various zoom lenses that reduce the error by using a cemented lens in each group and reducing the number of components in a positive zoom lens that is suitable for high zooming are disclosed in various patent publications. (See Patent Documents 1 to 4).

これらのズームレンズは物体側から正負正正の４つのレンズ群を有しており、２枚を接合したレンズや、３枚を接合したレンズで構成されている。 These zoom lenses have four lens groups that are positive, negative, positive, and positive from the object side, and are composed of a lens in which two lenses are cemented or a lens in which three lenses are cemented.

特開２００７−１７８８４６号公報JP 2007-178846 A 特開２００８−１２２４９２号公報JP 2008-122492 A 特開２００７−２５６６０４号公報JP 2007-256604 A 特開２００５−２５７８６８号公報JP 2005-257868 A

しかし、特許文献１及び特許文献２は、広角端の画角が８０〜９０°程度と広画角であるが、変倍比は２〜３．３倍程度と小さい。 However, Patent Document 1 and Patent Document 2 have a wide angle of view at a wide angle end of about 80 to 90 °, but the zoom ratio is as small as about 2 to 3.3.

また、特許文献３においては、２枚接合レンズや３枚接合レンズを使用して各群の要素が少ない構成になっているが、広角端の画角が６５°程度と狭く、変倍比が５倍程度と小さい。 Further, in Patent Document 3, a double-junction lens or a triple-junction lens is used to reduce the number of elements in each group. However, the angle of view at the wide-angle end is as narrow as about 65 °, and the zoom ratio is small. As small as 5 times.

また、特許文献４においては、変倍比は１４倍程度と大きく、２枚接合レンズや３枚接合レンズを使用して各群の要素が少ない構成になっているが、広角端の画角が６０°程度と狭い。 Further, in Patent Document 4, the zoom ratio is as large as about 14 times, and there are few elements in each group using a two-piece cemented lens or a three-piece cemented lens, but the angle of view at the wide-angle end is small. It is as narrow as about 60 °.

本発明は、高変倍、広画角に適した正負正正型ズームレンズであって、第３レンズ群に３枚接合レンズを使用することにより群の要素を少なくし、組み立て易く、コンパクトで、広画角及び高変倍比を有し、更に諸収差が良好に補正されたズームレンズを提案することを発明の目的とする。 The present invention is a positive / negative positive / positive zoom lens suitable for high zoom ratio and wide angle of view. By using a three-piece cemented lens in the third lens group, the elements of the group are reduced, and it is easy to assemble and is compact. Another object of the present invention is to propose a zoom lens having a wide angle of view and a high zoom ratio and in which various aberrations are favorably corrected.

上記目的は下記に記載した発明により達成される。 The above object is achieved by the invention described below.

１．物体側より順に、正の屈折力を有する第１レンズ群、負の屈折力を有する第２レンズ群、正の屈折力を有する第３レンズ群、及び正の屈折力を有する第４レンズ群から構成され、前記第１レンズ群、前記第２レンズ群、前記第３レンズ群及び前記第４レンズ群が、各レンズ群の空気間隔を変化させて光軸方向に移動し変倍を行うズームレンズにおいて、
前記第１レンズ群は、物体側より順に、負レンズ及び正レンズを有し、
前記第２レンズ群は、物体側より順に、負レンズ、負レンズ及び正レンズから構成され、
前記第３レンズ群は、物体側より順に、正レンズ１枚から成る第３ａレンズ群、並びに正レンズ、負レンズ及び正レンズの３枚接合レンズから成る第３ｂレンズ群から構成され、
以下の条件式を満足することを特徴とするズームレンズ。 1. In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a positive refractive power. A zoom lens configured to perform zooming by moving the first lens group, the second lens group, the third lens group, and the fourth lens group in the optical axis direction by changing an air interval of each lens group. In
The first lens group includes a negative lens and a positive lens in order from the object side,
The second lens group includes, in order from the object side, a negative lens, a negative lens, and a positive lens.
The third lens group includes, in order from the object side, a 3a lens group including one positive lens, and a 3b lens group including three cemented lenses of a positive lens, a negative lens, and a positive lens.
A zoom lens satisfying the following conditional expression:

０．１＜ｎ３ｂ２−ｎ３ｂ１＜０．７（１）
０．１＜ｎ３ｂ２−ｎ３ｂ３＜０．７（２）
但し、
ｎ３ｂ１：前記第３ｂレンズ群の最も物体側に位置する正レンズのｄ線に対する屈折率
ｎ３ｂ２：前記第３ｂレンズ群の中間に位置する負レンズのｄ線に対する屈折率
ｎ３ｂ３：前記第３ｂレンズ群の最も像側に位置する正レンズのｄ線に対する屈折率
２．以下の条件を満足することを特徴とする前記１に記載のズームレンズ。 0.1 <n3b2-n3b1 <0.7 (1)
0.1 <n3b2-n3b3 <0.7 (2)
However,
n3b1: Refractive index with respect to the d-line of the positive lens located closest to the object side of the 3b lens group n3b2: Refractive index with respect to the d-line of the negative lens located in the middle of the 3b lens group n3b3: of the 3b lens group 1. Refractive index with respect to d-line of the positive lens located closest to the image side 2. The zoom lens according to 1 above, wherein the following condition is satisfied.

０．４＜ｆ３／（ｆＷ×ｆＴ）^１／２＜１．０（３）
０．６＜ｆ３ａ／ｆ３＜２．０（４）
但し、
ｆ３：前記第３レンズ群の焦点距離
ｆＷ：広角端における全系の焦点距離
ｆＴ：望遠端における全系の焦点距離
ｆ３ａ：前記第３ａレンズ群の焦点距離
３．前記第２レンズ群は以下の条件を満足することを特徴とする前記１又は２に記載のズームレンズ。 0.4 <f3 / (fW × fT) ^1/2 <1.0 (3)
0.6 <f3a / f3 <2.0 (4)
However,
f3: focal length of the third lens group fW: focal length of the entire system at the wide-angle end fT: focal length of the entire system at the telephoto end f3a: focal length of the third lens group The zoom lens according to 1 or 2, wherein the second lens group satisfies the following condition.

−０．６＜ｆ２／（ｆＷ×ｆＴ）^１／２＜−０．２（５）
但し、
ｆ２：前記第２レンズ群の焦点距離
ｆＷ：広角端における全系の焦点距離
ｆＴ：望遠端における全系の焦点距離
４．前記第２レンズ群は、物体側より順に、負レンズ、並びに負レンズ及び正レンズとの接合レンズから成る２群３枚で構成されることを特徴とする前記１〜３の何れか１項に記載のズームレンズ。 −0.6 <f2 / (fW × fT) ^1/2 <−0.2 (5)
However,
f2: focal length of the second lens group fW: focal length of the entire system at the wide-angle end fT: focal length of the entire system at the telephoto end Any one of the items 1 to 3, wherein the second lens group is configured by two groups of three elements including a negative lens and a cemented lens of a negative lens and a positive lens in order from the object side. The described zoom lens.

５．前記第３レンズ群は少なくとも１面の非球面を有することを特徴とする前記１〜４の何れか１項に記載のズームレンズ。 5. 5. The zoom lens according to claim 1, wherein the third lens group has at least one aspheric surface.

６．前記第４レンズ群は、正レンズ１枚から成り、少なくとも１面の非球面を有することを特徴とする前記１〜５の何れか１項に記載のズームレンズ。 6). The zoom lens according to any one of 1 to 5, wherein the fourth lens group includes one positive lens and has at least one aspheric surface.

７．前記第１レンズ群は、物体側より順に、負レンズ及び正レンズから成る２枚のレンズで構成され、少なくとも１面の非球面を有することを特徴とする前記１〜６の何れか１項に記載のズームレンズ。 7). The first lens group includes two lenses including a negative lens and a positive lens in order from the object side, and has at least one aspheric surface. The described zoom lens.

８．前記第１レンズ群は、物体側より順に、負レンズ、正レンズ及び正レンズから成る３枚のレンズで構成されることを特徴とする前記１〜６の何れか１項に記載のズームレンズ。 8). The zoom lens according to any one of 1 to 6, wherein the first lens group includes three lenses including a negative lens, a positive lens, and a positive lens in order from the object side.

請求項１の効果
本発明においては、レンズ全系を正負正正４群ズーム構成とすることで、従来１０倍以上の高変倍ズームレンズに用いられてきた正負正負正５群ズーム構成より、ズーム群数が少なく、低コストでコンパクトなズームレンズを達成している。更に、各レンズ群の空気間隔を変化させるように４つのレンズ群が光軸方向に移動して変倍及び焦点位置変化補正を行うことにより収差補正の自由度が増え、良好な性能を維持しながら全長及び前玉径のコンパクト化を可能にしている。 According to the first aspect of the present invention, the entire lens system has a positive / negative / positive / positive four-group zoom configuration, so that the positive / negative / positive / negative / positive five-group zoom configuration conventionally used for a high-magnification zoom lens of 10 times or more has A compact zoom lens with a small number of zoom groups and low cost has been achieved. Furthermore, the four lens groups move in the direction of the optical axis so as to change the air spacing of each lens group to perform zooming and focal position change correction, thereby increasing the degree of freedom of aberration correction and maintaining good performance. However, it is possible to make the overall length and the front lens diameter compact.

更に、第１レンズ群は負レンズ及び正レンズを有する構成であるので、第１レンズ群で色収差を十分に補正することができる。特に、望遠側での軸上色収差や倍率色収差等を小さく抑えることが可能である。 Furthermore, since the first lens group includes a negative lens and a positive lens, the first lens group can sufficiently correct chromatic aberration. In particular, it is possible to suppress axial chromatic aberration, lateral chromatic aberration, and the like on the telephoto side.

更に、第２レンズ群は負レンズ、負レンズ及び正レンズから構成されている。第２レンズ群の負の屈折力を２枚の負レンズに分担することにより、各面の収差発生を抑えている。更に、正レンズを配置することにより色収差も補正できるため、第２レンズ群の負の屈折力を強くしても良好な収差補正ができ、第２群レンズの移動量を少なくしてコンパクト化を可能にしている。 Further, the second lens group includes a negative lens, a negative lens, and a positive lens. By assigning the negative refractive power of the second lens group to the two negative lenses, the occurrence of aberrations on each surface is suppressed. Furthermore, since chromatic aberration can be corrected by arranging a positive lens, good aberration correction can be achieved even if the negative refractive power of the second lens group is increased, and the amount of movement of the second lens group can be reduced to achieve compactness. It is possible.

更に、第３レンズ群は球面収差やコマ収差への寄与が大きいので、これらを良好に補正するために従来の高変倍ズームレンズにおいて第３レンズ群はレンズ４枚以上で構成されることが多い。レンズ枚数が多いと収差補正には有利であるが、コスト高やレンズの大型化を招くため好ましくない。本発明においては、４枚のレンズ構成にして、球面収差やコマ収差を良好に補正している。 Further, since the third lens group greatly contributes to spherical aberration and coma aberration, in order to correct these well, in the conventional high-magnification zoom lens, the third lens group may be composed of four or more lenses. Many. A large number of lenses is advantageous for correcting aberrations, but is not preferable because it increases costs and enlarges the lens. In the present invention, the spherical aberration and coma aberration are satisfactorily corrected with a four-lens configuration.

物体側から順に、正正負正の構成にすることにより、物体側に２枚の正レンズが配置されるので、物体側により強い正の屈折力を持たせることができるため、主点位置が物体側に配置され、第２レンズ群と第３レンズ群の間隔を短くすることができ、コンパクト化を可能にしている。 By constructing positive, negative, and positive structures in order from the object side, two positive lenses are arranged on the object side, so that a stronger positive refractive power can be given to the object side. The distance between the second lens group and the third lens group can be shortened, enabling compactness.

更に、従来の４枚構成の第３レンズ群は、正正負正の単レンズ４枚から成る構成や、正と正負の接合と正の３群４枚や、正と正と負正の接合の３群４枚で構成されることが多かった。このような構成だと、第３レンズ群の群要素数が３つ以上と多くなるため、鏡胴へのレンズ組み込み工数及びそのとき生じるレンズ間隔誤差・偏芯誤差の要因が比較的多くなり、生産時の管理が複雑化してしまい、良好な生産性が期待できなくなってしまう。本発明のように、第３レンズ群を、正の単レンズ１枚と正負正の３枚接合レンズから構成し、群要素を２つにすることで、上記の問題を緩和させることが可能である。 Further, the conventional third lens unit having four lenses has four positive, positive, negative and positive single lenses, four positive / positive / negative junctions and four positive groups, and positive / positive / negative / positive junctions. It was often composed of 4 elements in 3 groups. In such a configuration, the number of group elements in the third lens group increases to three or more, and therefore, the number of man-hours for assembling the lens into the lens barrel and the factors of the lens interval error and eccentricity error that occur at that time are relatively large. Management during production becomes complicated, and good productivity cannot be expected. As in the present invention, the third lens group is composed of one positive single lens and three positive and negative cemented lenses, and the number of group elements is two, so that the above problem can be alleviated. is there.

また、第３レンズ群の群要素を少なくするために、物体側の正正負の３枚を接合レンズにしても群要素は２つにできるが、正レンズを正レンズと負レンズとで挟む構成になるため、色収差やコマ収差の補正を十分行うことができない。本発明のように正の単レンズ１枚と、負レンズを前後から正レンズで挟む３枚接合レンズとから構成すると、第３レンズ群に入射した軸上光線を正レンズ成分で低くした後、３枚接合レンズに入射させることができるので、３枚接合レンズ内の負レンズに十分な負の屈折力を持たせることが可能になり、色収差や球面収差の補正がし易くなる。更に、負レンズに屈折率の高い材料を用いて接合面の屈折率差を比較的大きく設定できるため、球面収差やコマ収差の補正がし易くなる。 Further, in order to reduce the number of group elements in the third lens group, the number of positive and negative lenses on the object side can be made to be two, but the number of group elements can be reduced to two. However, the positive lens is sandwiched between the positive lens and the negative lens. Therefore, chromatic aberration and coma cannot be corrected sufficiently. When composed of one positive single lens and a three-piece cemented lens sandwiching the negative lens between the front and rear as in the present invention, the axial ray incident on the third lens group is lowered by the positive lens component, Since the light can enter the three-piece cemented lens, the negative lens in the three-piece cemented lens can have sufficient negative refractive power, and correction of chromatic aberration and spherical aberration can be easily performed. Furthermore, since the refractive index difference of the cemented surface can be set relatively large by using a material having a high refractive index for the negative lens, it becomes easy to correct spherical aberration and coma aberration.

第３レンズ群の３枚接合レンズの屈折率を条件式（１），（２）の範囲に設定することにより、良好な性能を得ることができる。 By setting the refractive index of the three cemented lenses in the third lens group within the ranges of the conditional expressions (1) and (2), good performance can be obtained.

条件式（１），（２）の下限を上回ると、３枚接合レンズ中の各レンズ間の屈折率差が小さくなって接合面の曲率半径が小さくなり過ぎるのを抑え、第３ｂレンズ群の正レンズの縁厚が不足して加工性が悪くなることを防止できる。なお、縁厚確保のために正レンズを厚くすると、全長が大きくなってしまう。 When the lower limit of conditional expressions (1) and (2) is exceeded, the difference in refractive index between the lenses in the three-piece cemented lens is reduced to prevent the curvature radius of the cemented surface from becoming too small. It can be prevented that the edge thickness of the positive lens is insufficient and the workability is deteriorated. Note that if the positive lens is thickened to ensure the edge thickness, the overall length becomes large.

条件式（１），（２）の上限を下回ると、３枚接合レンズ中の各レンズ間の屈折率差が大きくなって接合面の曲率半径が大きくなり過ぎるのを抑え、ここで発生する球面収差、コマ収差等の補正が良好にできる。 If the upper limit of conditional expressions (1) and (2) is not reached, the difference in refractive index between the lenses in the three-piece cemented lens is prevented from excessively increasing the radius of curvature of the cemented surface. Aberrations, coma, etc. can be corrected well.

また、下記の条件式がより望ましい。 Further, the following conditional expression is more desirable.

０．２＜ｎ３ｂ２−ｎ３ｂ１＜０．６
０．１＜ｎ３ｂ２−ｎ３ｂ３＜０．５
また、下記の条件式が更に望ましい。 0.2 <n3b2-n3b1 <0.6
0.1 <n3b2-n3b3 <0.5
Further, the following conditional expression is more desirable.

０．３＜ｎ３ｂ２−ｎ３ｂ１＜０．５
０．２＜ｎ３ｂ２−ｎ３ｂ３＜０．４
請求項２の効果
第３レンズ群の屈折力が条件式（３）の下限を上回ると、第３レンズ群の屈折力が強くなり過ぎず、諸収差の発生や偏芯誤差・形状誤差による収差変動を小さく抑えることができる。 0.3 <n3b2-n3b1 <0.5
0.2 <n3b2-n3b3 <0.4
The effect of claim 2 If the refractive power of the third lens group exceeds the lower limit of the conditional expression (3), the refractive power of the third lens group does not become too strong, and various aberrations and aberrations due to decentering errors and shape errors. Variations can be kept small.

また、条件式（３）の上限を下回ると、第３レンズ群の屈折力が弱くなり過ぎて第３レンズ群と像面との間隔が長くなり、レンズ全長が大きくなることを抑えられるので、ズームレンズのコンパクト性が損なわれることがない。 If the upper limit of conditional expression (3) is not reached, the refractive power of the third lens group becomes too weak, and the distance between the third lens group and the image plane becomes long, and it is possible to prevent the total lens length from increasing. The compactness of the zoom lens is not impaired.

条件式（４）は、第３レンズ群の屈折力が条件式（３）の範囲に規定されたズームレンズにおいて、第３ａレンズ群の屈折力を適切に設定する条件である。第３ａレンズ群の屈折力が条件式（４）の下限を上回ると、第３ａレンズ群の屈折力が強くなり過ぎず、球面収差やコマ収差が補正過剰になることを抑えることができる。更に、偏芯誤差・形状誤差による収差変動を小さく抑えることができる。 Conditional expression (4) is a condition for appropriately setting the refractive power of the third-a lens group in the zoom lens in which the refractive power of the third lens group is defined in the range of the conditional expression (3). When the refractive power of the 3a lens group exceeds the lower limit of the conditional expression (4), the refractive power of the 3a lens group does not become too strong, and it is possible to suppress overcorrection of spherical aberration and coma aberration. Furthermore, aberration fluctuations due to eccentricity errors and shape errors can be suppressed to a small level.

また、条件式（４）の上限を下回ると、第３ａレンズ群の屈折力が弱くなり過ぎず、球面収差やコマ収差が補正不足になることを抑えることができる。更に、第３レンズ群の主点位置が物体側に配置され、第２レンズ群と第３レンズ群の間隔を短くすることができ、ズームレンズ全系のコンパクト化が可能になる。 If the upper limit of conditional expression (4) is not reached, the refractive power of the 3a lens group does not become too weak, and it is possible to prevent the spherical aberration and the coma from being insufficiently corrected. Further, the principal point position of the third lens group is arranged on the object side, the distance between the second lens group and the third lens group can be shortened, and the entire zoom lens system can be made compact.

０．５＜ｆ３／（ｆＷ×ｆＴ）^１／２＜０．８５
０．７＜ｆ３ａ／ｆ３＜１．６
また、下記の条件式が更に望ましい。 0.5 <f3 / (fW × fT) ^1/2 <0.85
0.7 <f3a / f3 <1.6
Further, the following conditional expression is more desirable.

０．５８＜ｆ３／（ｆＷ×ｆＴ）^１／２＜０．７５
０．８＜ｆ３ａ／ｆ３＜１．２
請求項３の効果
第２レンズ群の屈折力が条件式（５）の下限を上回ると、屈折力が強くなり過ぎず、諸収差発生や偏芯・形状誤差による収差変動を小さく抑えることができる。 0.58 <f3 / (fW × fT) ^1/2 <0.75
0.8 <f3a / f3 <1.2
Effect of Claim 3 If the refractive power of the second lens unit exceeds the lower limit of the conditional expression (5), the refractive power does not become too strong, and aberration fluctuations due to the occurrence of various aberrations and eccentricity / shape errors can be kept small. .

また、条件式（５）の上限を下回ると、第２レンズ群の移動量を小さくできるため、コンパクト性が損なわれることがない。 If the upper limit of conditional expression (5) is not reached, the amount of movement of the second lens group can be reduced, so that compactness is not impaired.

−０．５＜ｆ２／（ｆＷ×ｆＴ）^１／２＜−０．２５
また、下記の条件式が更に望ましい。 −0.5 <f2 / (fW × fT) ^1/2 <−0.25
Further, the following conditional expression is more desirable.

−０．４２＜ｆ２／（ｆＷ×ｆＴ）^１／２＜−０．３
請求項４の効果
第２レンズ群を負の単レンズ及び負レンズと正レンズとの接合レンズから構成すると、群要素は２つになり、鏡胴へのレンズ組み込み工数、及びそのとき生じるレンズ間隔誤差や偏芯誤差の要因が比較的少なくなり、管理の複雑化を抑えることが可能になる。第２レンズ群の全てのレンズが単レンズで構成されるより、生産管理がし易くなり、生産性の良いレンズを実現できる。 −0.42 <f2 / (fW × fT) ^1/2 <−0.3
The effect of claim 4 If the second lens group is composed of a negative single lens and a cemented lens of a negative lens and a positive lens, the number of group elements is two, the number of steps for assembling the lens into the lens barrel, and the resulting lens spacing The causes of errors and eccentricity errors are relatively small, and it is possible to suppress management complexity. Since all the lenses of the second lens group are composed of a single lens, production management is facilitated, and a lens with good productivity can be realized.

請求項５の効果
第３レンズ群は球面収差やコマ収差への寄与が大きいため、非球面を少なくとも１面有すると、これらの収差を良好に補正することができる。 Advantages of Claim 5 Since the third lens group greatly contributes to spherical aberration and coma aberration, if there is at least one aspheric surface, these aberrations can be corrected satisfactorily.

また、開口絞りを第３レンズ群の物体側に設けることが望ましい。開口絞りを第３レンズ群の物体側に配置すると、本発明のズームレンズのほぼ中央付近に配置されるので、諸収差の補正に有利になる。更に、開口絞りが像面から遠くなるため、ＣＣＤ・ＣＭＯＳ光学系で要求されるテレセントリック性の確保がし易くなる。一方、開口絞りを第３レンズ群内に配置すると、第３レンズ群が開口絞りにより２つの群に分割されるため、偏芯誤差の発生を招くため好ましくない。また、開口絞りを第３レンズ群の像側に配置すると、開口絞りが像面に近くなるため、ＣＣＤ・ＣＭＯＳ光学系で要求されるテレセントリック性の確保が難しくなる。 It is desirable to provide an aperture stop on the object side of the third lens group. If the aperture stop is arranged on the object side of the third lens group, it is arranged near the center of the zoom lens of the present invention, which is advantageous for correcting various aberrations. Furthermore, since the aperture stop is far from the image plane, it is easy to ensure the telecentricity required in the CCD / CMOS optical system. On the other hand, disposing the aperture stop in the third lens group is not preferable because the third lens group is divided into two groups by the aperture stop, which causes an eccentricity error. Further, when the aperture stop is disposed on the image side of the third lens group, the aperture stop becomes close to the image plane, so that it is difficult to ensure the telecentricity required in the CCD / CMOS optical system.

請求項６の効果
４群タイプのズームレンズでは、第４レンズ群より像側にパワーを持った光学素子（光学部品）が存在しないので、第４レンズ群で発生する収差は、その後の光線経路においては拡大されず目立ち難い。従って、正レンズ１枚構成でもレンズ全系の光学性能へ与える影響が小さい。更に、少なくとも１面を非球面にすると、１０倍程度の高変倍ズームレンズにおいて、コマ収差等を効果的に補正することができる。 In the fourth group type zoom lens, since there is no optical element (optical component) having power on the image side from the fourth lens group, the aberration generated in the fourth lens group is the subsequent ray path. Is not magnified and is inconspicuous. Therefore, even a single positive lens configuration has little effect on the optical performance of the entire lens system. Further, when at least one surface is aspherical, coma aberration and the like can be effectively corrected in a high-magnification zoom lens of about 10 times.

更に、無限遠物体から近距離物体へ合焦する際、第４レンズ群を移動させる、いわゆるリアフォーカスを採用することが望ましい。第１レンズ群でフォーカシングすると、近距離の合焦のために第１レンズ群を繰り出したとき、周辺光量比を確保するために前玉径が大きくなってしまうが、第４レンズ群によるフォーカシングではそのようなことがないので、コンパクト性に優れたレンズを実現することができる。また、可動レンズ群の重量も軽くてすむため、駆動機構への負荷が小さく、電力消費が少ない簡略な構造のズームレンズが実現できる。 Furthermore, it is desirable to adopt a so-called rear focus that moves the fourth lens group when focusing from an object at infinity to an object at a short distance. When focusing with the first lens group, when the first lens group is extended for focusing at a short distance, the front lens diameter becomes large in order to ensure the peripheral light quantity ratio, but with focusing by the fourth lens group, Since this is not the case, a lens having excellent compactness can be realized. Further, since the movable lens group can be light in weight, it is possible to realize a zoom lens having a simple structure with a small load on the driving mechanism and low power consumption.

更に、第４レンズ群は、広角端から望遠端への変倍において広角端から中間焦点距離付近へは物体側に移動し、中間焦点距離付近から望遠端へは像側に移動することが望ましい。広角端から中間焦点距離付近においては、画角が広いため画面周辺部のコマ収差の発生が大きくなる。一般にレンズの光軸近辺よりレンズ周辺部の方が収差の発生が大きくなるため、第４レンズ群を通過する軸外光束は、レンズの光軸に近い部分を通過する方が、収差補正上有利である。広角端から中間焦点距離付近において第４レンズ群を物体側に移動すると、第３レンズ群に近い位置に配置できるため、軸外光束は第４レンズ群の光軸に近い位置を通過させることができる。 Further, it is desirable that the fourth lens unit moves to the object side from the wide-angle end to the vicinity of the intermediate focal length and to move to the image side from the vicinity of the intermediate focal length to the telephoto end in zooming from the wide-angle end to the telephoto end. . In the vicinity of the intermediate focal length from the wide-angle end, the occurrence of coma aberration at the periphery of the screen increases due to the wide angle of view. In general, aberration occurs more in the lens peripheral portion than in the vicinity of the optical axis of the lens. Therefore, it is advantageous in terms of aberration correction that the off-axis light beam passing through the fourth lens group passes through a portion near the optical axis of the lens. It is. When the fourth lens group is moved to the object side in the vicinity of the intermediate focal length from the wide-angle end, the fourth lens group can be disposed at a position close to the third lens group, so that the off-axis light beam can pass through a position close to the optical axis of the fourth lens group. it can.

一方、本発明のような正の第４レンズ群によるフォーカシングにおいて、無限遠物体から近距離物体へ合焦する際、第４レンズ群は物体側に移動し、また、レンズ全系の焦点距離が長くなるほど移動量が大きくなるので、第３レンズ群と第４レンズ群との間隔を十分確保する必要がある。そこで、中間焦点距離付近から望遠端においては、第４レンズ群を像側に移動すると、第３レンズ群との間隔が広くなるので、第４群によるフォーカシングの移動量を確保することができる。 On the other hand, in focusing by the positive fourth lens unit as in the present invention, when focusing from an object at infinity to a near object, the fourth lens unit moves to the object side, and the focal length of the entire lens system is Since the amount of movement increases as the length increases, it is necessary to ensure a sufficient distance between the third lens group and the fourth lens group. Therefore, when the fourth lens unit is moved to the image side from the vicinity of the intermediate focal length to the telephoto end, the distance from the third lens unit becomes wide, so that the amount of focusing movement by the fourth unit can be ensured.

請求項７の効果
第１レンズ群を負レンズと正レンズから構成すると、第１レンズ群で色消しを十分に補正できるとともに、２枚構成なので第１レンズ群の厚みが薄くなり、前玉径の小径化にも有利である。 When the first lens group is composed of a negative lens and a positive lens, the first lens group can sufficiently correct the achromatic color, and since it has two lenses, the thickness of the first lens group is reduced and the front lens diameter is reduced. This is also advantageous for reducing the diameter.

更に、第１レンズ群は、少なくとも１面を非球面にすると好ましい。第１レンズ群を通過する軸外光束は、広角端から望遠端において通過位置が異なるため、高変倍になるほどコマ収差をバランスよく補正することが難しくなるが、少なくとも１面を非球面にすることにより、変倍時の収差変動を小さくでき、良好な性能が確保できる。 Further, it is preferable that at least one surface of the first lens group is an aspherical surface. Since the off-axis light beam passing through the first lens group has a different passing position from the wide-angle end to the telephoto end, it becomes more difficult to correct coma in a balanced manner as the zoom ratio increases, but at least one surface is aspherical. As a result, aberration variation during zooming can be reduced, and good performance can be ensured.

更に、負レンズと正レンズを接合レンズとすることが望ましい。このような構成にすると第１レンズ群の要素が１つになり、鏡胴へのレンズ組み込み工数、及びそのとき生じるレンズ間隔誤差や偏芯誤差の要因が少なくなり、管理の複雑化を抑えることが可能になり、生産管理がし易くなり、生産性の良いレンズを実現できる。 Furthermore, it is desirable to use a negative lens and a positive lens as a cemented lens. With this configuration, the number of elements of the first lens group becomes one, the number of steps for assembling the lens into the lens barrel, and the factors of the lens interval error and eccentricity error that occur at that time are reduced, and the management complexity is suppressed. Therefore, it becomes easy to manage production, and a lens with good productivity can be realized.

請求項８の効果
第１レンズ群を負レンズと正レンズと正レンズとの３枚の構成にすると、２枚構成より収差補正の自由度が増え、変倍による収差変動をより小さく抑えることができる。第１レンズ群を通過する軸外光束は、広角端から望遠端において通過位置が異なるため、高変倍になるほどコマ収差をバランスよく補正することが難しくなるが、第１レンズ群の正の屈折力を２枚の正レンズに分担することにより、非球面レンズを用いることなく、変倍による収差変動を小さく抑えることができる。 The effect of Claim 8 If the 1st lens group is made into the structure of 3 sheets of a negative lens, a positive lens, and a positive lens, the freedom degree of an aberration correction will increase from 2 lens structures, and the aberration fluctuation | variation by zooming can be suppressed smaller. it can. Since the off-axis light beam passing through the first lens group has different passing positions from the wide-angle end to the telephoto end, it becomes more difficult to correct coma in a balanced manner as the zoom ratio becomes higher. However, the positive refraction of the first lens group is difficult. By sharing the force between the two positive lenses, it is possible to suppress aberration fluctuations due to zooming without using an aspheric lens.

更に、負レンズと正レンズの接合レンズと正レンズの２群３枚構成にすることが望ましい。このような構成にすると第１レンズ群の群要素が２つになり、鏡胴へのレンズ組み込み工数、及びそのとき生じるレンズ間隔誤差や偏芯誤差の要因が比較的少なくなり、管理の複雑化を抑えることが可能になり、生産管理がし易くなり、生産性の良いレンズを実現できる。 Furthermore, it is desirable to have a two-group three-lens configuration of a cemented lens of a negative lens and a positive lens and a positive lens. With this configuration, the number of group elements of the first lens group is two, and the number of steps for assembling the lens into the lens barrel and the factors of the lens distance error and eccentricity error that occur at that time are relatively small, and management is complicated. This makes it possible to suppress production, facilitate production management, and realize a lens with high productivity.

更に、広角端から望遠端への変倍において、第１レンズ群は第１レンズ群と第２レンズ郡との間隔が増大するように物体側に移動することが望ましい。望遠端への変倍において第１レンズ群が物体側に移動すると、広角端では第１レンズ群は像側に配置されるので、広角端の全長が小さくでき、画角が７５°以上を有するズームレンズにおいて、前玉径が大きくなるのを抑えることができる。 Further, in zooming from the wide-angle end to the telephoto end, it is desirable that the first lens unit moves to the object side so that the distance between the first lens unit and the second lens unit increases. When the first lens unit moves toward the object side during zooming to the telephoto end, the first lens unit is disposed on the image side at the wide angle end, so that the total length of the wide angle end can be reduced, and the field angle is 75 ° or more. In the zoom lens, it is possible to suppress an increase in the front lens diameter.

実施例１のズームレンズの構成図である。1 is a configuration diagram of a zoom lens of Example 1. FIG. 実施例１のズームレンズの広角端における収差図である。FIG. 3 is an aberration diagram at a wide angle end of the zoom lens according to Example 1; 実施例１のズームレンズの中間焦点距離における収差図である。FIG. 4 is an aberration diagram for the zoom lens of Example 1 at an intermediate focal length. 実施例１のズームレンズの望遠端における収差図である。FIG. 4 is an aberration diagram at a telephoto end of the zoom lens in Example 1; 実施例２のズームレンズの構成図である。FIG. 6 is a configuration diagram of a zoom lens of Example 2. 実施例２のズームレンズの広角端における収差図である。FIG. 6 is an aberration diagram at a wide-angle end of the zoom lens according to Example 2; 実施例２のズームレンズの中間焦点距離における収差図である。6 is an aberration diagram at an intermediate focal length of the zoom lens of Example 2. FIG. 実施例２のズームレンズの望遠端における収差図である。6 is an aberration diagram at a telephoto end of a zoom lens in Example 2. FIG. 実施例３のズームレンズの構成図である。FIG. 6 is a configuration diagram of a zoom lens of Example 3. 実施例３のズームレンズの広角端における収差図である。FIG. 10 is an aberration diagram at a wide-angle end of the zoom lens according to Example 3; 実施例３のズームレンズの中間焦点距離における収差図である。FIG. 10 is an aberration diagram at an intermediate focal length of the zoom lens according to Example 3; 実施例３のズームレンズの望遠端における収差図である。6 is an aberration diagram at a telephoto end of a zoom lens in Example 3; FIG. 実施例４のズームレンズの構成図である。6 is a configuration diagram of a zoom lens of Example 4. FIG. 実施例４のズームレンズの広角端における収差図である。FIG. 10 is an aberration diagram at a wide-angle end of the zoom lens according to Example 4; 実施例４のズームレンズの中間焦点距離における収差図である。FIG. 10 is an aberration diagram at an intermediate focal length of the zoom lens according to Example 4; 実施例４のズームレンズの望遠端における収差図である。FIG. 10 is an aberration diagram at a telephoto end of a zoom lens in Example 4; 実施例５のズームレンズの構成図である。FIG. 6 is a configuration diagram of a zoom lens of Example 5. 実施例５のズームレンズの広角端における収差図である。FIG. 10 is an aberration diagram at a wide-angle end of the zoom lens according to Example 5; 実施例５のズームレンズの中間焦点距離における収差図である。FIG. 10 is an aberration diagram at an intermediate focal length of the zoom lens according to Example 5; 実施例５のズームレンズの望遠端における収差図である。10 is an aberration diagram at a telephoto end of a zoom lens in Example 5. FIG.

以下に本発明のズームレンズに関する実施例を示す。 Examples relating to the zoom lens of the present invention are shown below.

なお、以下に示す符号は下記の通りである。 In addition, the code | symbol shown below is as follows.

ｆ：全系の焦点距離
Ｆ：Ｆナンバー
ｆＢ：バックフォーカス
ω：半画角
Ｒ：曲率半径
Ｄ：面間隔
Ｎｄ：レンズ材料のｄ線に対する屈折率
νｄ：レンズ材料のアッベ数
＊：非球面
非球面の形状は、面の頂点を原点とし光軸方向をＸ軸とした直交座標系において、頂点曲率をＣ、円錐定数をＫ、非球面係数をＡ４、Ａ６、Ａ８、Ａ１０、Ａ１２をとして数１で表す。 f: Focal length of entire system F: F number fB: Back focus ω: Half angle of view R: Radius of curvature D: Surface interval Nd: Refractive index of lens material with respect to d-line νd: Abbe number of lens material *: Aspherical surface The shape of the spherical surface is a number in the Cartesian coordinate system with the vertex of the surface as the origin and the optical axis direction as the X axis, with the vertex curvature being C, the conic constant being K, and the aspherical coefficients being A4, A6, A8, A10, and A12. It is represented by 1.

また、非球面係数は、１０のべき乗数（例えば、２．５×１０^−３）をＥ（例えば、２．５×Ｅ−３）を用いて表す。
［実施例１］
・全体諸元を以下に示す。 In addition, the aspheric coefficient represents a power of 10 (for example, 2.5 × 10 ⁻³ ) using E (for example, 2.5 × E−3).
[Example 1]
・ The overall specifications are shown below.

ｆ 4.7〜14.9〜47.0
Ｆ 3.51〜5.58〜5.8
ｆＢ 1.0
２ω 80°〜30°〜10°
・レンズ面データを以下に示す。
面番号Ｒ(mm) Ｄ(mm) Ｎｄ νｄ有効半径(mm)
１ 17.056 0.90 1.9229 20.9 8.17
２ 11.910 3.72 1.7725 49.6 7.28
３(＊) 174.739 ｄ１ 6.80
４ 13733.280 0.70 1.9037 31.3 4.73
５ 5.036 3.09 3.52
６ -10.055 0.55 1.5831 59.4 3.21
７ 7.343 1.60 1.9229 20.9 3.15
８ 147.406 ｄ２ 3.05
９(絞り) ∞ 0.80 1.98
10 5.547 1.72 1.6516 58.4 2.42
11 94.730 0.10 2.40
12 6.007 2.67 1.4970 81.6 2.39
13 -8.219 0.50 1.9037 31.3 2.11
14 4.000 1.33 1.5927 35.5 2.03
15(＊) 52.498 ｄ３ 2.07
16(＊) -377.026 1.91 1.5305 56.0 3.77
17(＊) -13.130 ｄ４ 3.90
18 ∞ 1.50 1.5168 64.2 4.00
19 ∞ 4.00
・非球面係数を以下に示す。
第３面
K=0.0000E+00,A4=0.9837E-05,A6=0.7103E-07,A8=-0.2794E-08,A10=0.4500E-10
第15面
K=0.0000E+00,A4=0.3433E-02,A6=0.1606E-03,A8=0.1336E-04
第16面
K=0.0000E+00,A4=-0.5210E-03,A6=0.7354E-04,A8=-0.2087E-05
第17面
K=0.0000E+00,A4=-0.7139E-03,A6=0.2443E-04,A8=0.1702E-05,A10=-0.9131E-07
・変倍時の各種データを以下に示す。 f 4.7-14.9-47.0
F 3.51 ~ 5.58 ~ 5.8
fB 1.0
2ω 80 ° -30 ° -10 °
・ Lens surface data is shown below.
Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 17.056 0.90 1.9229 20.9 8.17
2 11.910 3.72 1.7725 49.6 7.28
3 (*) 174.739 d1 6.80
4 13733.280 0.70 1.9037 31.3 4.73
5 5.036 3.09 3.52
6 -10.055 0.55 1.5831 59.4 3.21
7 7.343 1.60 1.9229 20.9 3.15
8 147.406 d2 3.05
9 (Aperture) ∞ 0.80 1.98
10 5.547 1.72 1.6516 58.4 2.42
11 94.730 0.10 2.40
12 6.007 2.67 1.4970 81.6 2.39
13 -8.219 0.50 1.9037 31.3 2.11
14 4.000 1.33 1.5927 35.5 2.03
15 (*) 52.498 d3 2.07
16 (*) -377.026 1.91 1.5305 56.0 3.77
17 (*) -13.130 d4 3.90
18 ∞ 1.50 1.5168 64.2 4.00
19 ∞ 4.00
・ Aspheric coefficient is shown below.
Third side
K = 0.0000E + 00, A4 = 0.9837E-05, A6 = 0.7103E-07, A8 = -0.2794E-08, A10 = 0.4500E-10
15th page
K = 0.0000E + 00, A4 = 0.3433E-02, A6 = 0.1606E-03, A8 = 0.1336E-04
16th page
K = 0.0000E + 00, A4 = -0.5210E-03, A6 = 0.7354E-04, A8 = -0.2087E-05
17th page
K = 0.0000E + 00, A4 = -0.7139E-03, A6 = 0.2443E-04, A8 = 0.1702E-05, A10 = -0.9131E-07
-Various data at the time of zooming are shown below.

ｆＦｄ１ｄ２ｄ３ｄ４
4.70 3.51 0.73 11.90 2.45 3.46
14.86 5.58 5.63 4.72 9.78 5.18
47.00 5.80 14.00 1.01 11.71 3.21
・レンズ群データを以下に示す。
レンズ群始面焦点距離(mm)
１１ 26.40
２４ -4.89
３９ 8.85
４ 16 25.60
・前述の各条件式に対応する値を以下に示す。 f F d1 d2 d3 d4
4.70 3.51 0.73 11.90 2.45 3.46
14.86 5.58 5.63 4.72 9.78 5.18
47.00 5.80 14.00 1.01 11.71 3.21
・ Lens group data is shown below.
Lens group Start surface Focal length (mm)
1 1 26.40
2 4 -4.89
3 9 8.85
4 16 25.60
-Values corresponding to the above conditional expressions are shown below.

条件式(１)＝0.407
条件式(２)＝0.311
条件式(３)＝0.595
条件式(４)＝1.014
条件式(５)＝-0.329
なお、図１はズームレンズの構成図であり、主要な構成は下記の如くである。 Conditional expression (1) = 0.407
Conditional expression (2) = 0.311
Conditional expression (3) = 0.595
Conditional expression (4) = 1.014
Conditional expression (5) = -0.329
FIG. 1 is a configuration diagram of a zoom lens, and the main configuration is as follows.

本ズームレンズは、物体側より順に、第１レンズ群Ｇｒ１、第２レンズ群Ｇｒ２、第３レンズ群Ｇｒ３及び第４レンズ群Ｇｒ４から構成される。第１レンズ群Ｇｒ１は、物体側より順に、負レンズ及び正レンズから構成され、正の屈折力を有する。第２レンズ群Ｇｒ２は、物体側より順に、負レンズ、負レンズ及び正レンズから構成され、負の屈折力を有する。第３レンズ群Ｇｒ３は、物体側より順に、正レンズ１枚から成る第３ａレンズ群Ｇｒ３ａ、並びに正レンズ、負レンズ及び正レンズの３枚接合レンズから成る第３ｂレンズ群Ｇｒ３ｂから構成され、正の屈折力を有する。第４レンズ群Ｇｒ４は、レンズ１枚から成り、正の屈折力を有する。そして、第１レンズ群Ｇｒ１、第２レンズ群Ｇｒ２、第３レンズ群Ｇｒ３及び第４レンズ群Ｇｒ４が、各レンズ群の空気間隔を変化させて光軸方向に移動し変倍を行う。 The zoom lens includes, in order from the object side, a first lens group Gr1, a second lens group Gr2, a third lens group Gr3, and a fourth lens group Gr4. The first lens group Gr1 is composed of a negative lens and a positive lens in order from the object side, and has a positive refractive power. The second lens group Gr2 includes, in order from the object side, a negative lens, a negative lens, and a positive lens, and has a negative refractive power. The third lens group Gr3 includes, in order from the object side, a third a lens group Gr3a including one positive lens, and a third b lens group Gr3b including three cemented lenses of a positive lens, a negative lens, and a positive lens. Have a refractive power of. The fourth lens group Gr4 includes one lens and has a positive refractive power. Then, the first lens group Gr1, the second lens group Gr2, the third lens group Gr3, and the fourth lens group Gr4 move in the optical axis direction by changing the air interval of each lens group, and perform zooming.

図２はズームレンズの広角端における収差図、図３はズームレンズの中間焦点距離における収差図、図４はズームレンズの望遠端における収差図である。
［実施例２］
・全体諸元を以下に示す。 2 is an aberration diagram at the wide-angle end of the zoom lens, FIG. 3 is an aberration diagram at an intermediate focal length of the zoom lens, and FIG. 4 is an aberration diagram at the telephoto end of the zoom lens.
[Example 2]
・ The overall specifications are shown below.

ｆ 4.7〜14.9〜47.0
Ｆ 3.69〜5.25〜5.8
ｆＢ 1.0
２ω 80°〜30°〜10°
・レンズ面データを以下に示す。
面番号Ｒ(mm) Ｄ(mm) Ｎｄ νｄ有効半径(mm)
１ 18.258 0.90 1.9229 20.9 8.18
２ 13.323 3.68 1.7292 54.7 7.43
３(＊) -502.607 ｄ１ 6.70
４ -87.916 0.70 2.0033 28.3 4.65
５ 5.503 2.75 3.61
６ -12.495 0.55 1.5168 64.2 3.46
７ 7.550 1.69 1.9229 20.9 3.45
８ 93.185 ｄ２ 3.35
９(絞り) ∞ 0.80 2.00
10 5.043 1.76 1.5691 71.3 2.37
11 38.815 1.25 2.32
12 4.986 2.30 1.4875 70.4 2.27
13 -5.020 0.50 1.8830 40.8 2.03
14 4.000 1.49 1.6691 55.4 1.97
15(＊) 36.947 ｄ３ 2.00
16(＊) 16.535 1.54 1.5305 56.0 3.79
17(＊) -410.427 ｄ４ 3.99
18 ∞ 1.50 1.5168 64.2 4.00
19 ∞ 4.00
・非球面係数を以下に示す。
第３面
K=0.0000E+00,A4=0.1307E-04,A6=-0.4494E-07,A8=0.6750E-09,A10=-0.7000E-11
第15面
K=0.0000E+00,A4=0.2580E-02,A6=0.9821E-04,A8=-0.9213E-06
第16面
K=0.0000E+00,A4=-0.9825E-03,A6=0.1501E-04,A8=-0.4643E-05
第17面
K=0.0000E+00,A4=-0.1407E-02,A6=0.4745E-05,A8=-0.3763E-05,A10=0.3144E-07
・変倍時の各種データを以下に示す。 f 4.7-14.9-47.0
F 3.69-5.25-5.8
fB 1.0
2ω 80 ° -30 ° -10 °
・ Lens surface data is shown below.
Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 18.258 0.90 1.9229 20.9 8.18
2 13.323 3.68 1.7292 54.7 7.43
3 (*) -502.607 d1 6.70
4 -87.916 0.70 2.0033 28.3 4.65
5 5.503 2.75 3.61
6 -12.495 0.55 1.5168 64.2 3.46
7 7.550 1.69 1.9229 20.9 3.45
8 93.185 d2 3.35
9 (Aperture) ∞ 0.80 2.00
10 5.043 1.76 1.5691 71.3 2.37
11 38.815 1.25 2.32
12 4.986 2.30 1.4875 70.4 2.27
13 -5.020 0.50 1.8830 40.8 2.03
14 4.000 1.49 1.6691 55.4 1.97
15 (*) 36.947 d3 2.00
16 (*) 16.535 1.54 1.5305 56.0 3.79
17 (*) -410.427 d4 3.99
18 ∞ 1.50 1.5168 64.2 4.00
19 ∞ 4.00
・ Aspheric coefficient is shown below.
Third side
K = 0.0000E + 00, A4 = 0.1307E-04, A6 = -0.4494E-07, A8 = 0.6750E-09, A10 = -0.7000E-11
15th page
K = 0.0000E + 00, A4 = 0.2580E-02, A6 = 0.9821E-04, A8 = -0.9213E-06
16th page
K = 0.0000E + 00, A4 = -0.9825E-03, A6 = 0.1501E-04, A8 = -0.4643E-05
17th page
K = 0.0000E + 00, A4 = -0.1407E-02, A6 = 0.4745E-05, A8 = -0.3763E-05, A10 = 0.3144E-07
-Various data at the time of zooming are shown below.

ｆＦｄ１ｄ２ｄ３ｄ４
4.70 3.69 0.70 13.96 2.46 3.24
14.86 5.25 6.50 4.88 2.89 9.07
47.01 5.80 14.43 1.02 10.05 4.13
・レンズ群データを以下に示す。
レンズ群始面焦点距離(mm)
１１ 26.56
２４ -5.32
３９ 9.50
４ 16 30.00
・前述の各条件式に対応する値を以下に示す。 f F d1 d2 d3 d4
4.70 3.69 0.70 13.96 2.46 3.24
14.86 5.25 6.50 4.88 2.89 9.07
47.01 5.80 14.43 1.02 10.05 4.13
・ Lens group data is shown below.
Lens group Start surface Focal length (mm)
1 1 26.56
2 4 -5.32
3 9 9.50
4 16 30.00
-Values corresponding to the above conditional expressions are shown below.

条件式(１)＝0.396
条件式(２)＝0.214
条件式(３)＝0.639
条件式(４)＝1.052
条件式(５)＝-0.358
なお、図５はズームレンズの構成図であり、主要な構成は実施例１と同様である。 Conditional expression (1) = 0.396
Conditional expression (2) = 0.214
Conditional expression (3) = 0.639
Conditional expression (4) = 1.052
Conditional expression (5) = -0.358
FIG. 5 is a configuration diagram of the zoom lens, and the main configuration is the same as that of the first embodiment.

図６はズームレンズの広角端における収差図、図７はズームレンズの中間焦点距離における収差図、図８はズームレンズの望遠端における収差図である。
［実施例３］
・全体諸元を以下に示す。 6 is an aberration diagram at the wide-angle end of the zoom lens, FIG. 7 is an aberration diagram at the intermediate focal length of the zoom lens, and FIG. 8 is an aberration diagram at the telephoto end of the zoom lens.
[Example 3]
・ The overall specifications are shown below.

ｆ 4.0〜12.7〜40.0
Ｆ 3.51〜4.88〜5.8
ｆＢ 1.0
２ω 80°〜30°〜10°
・レンズ面データを以下に示す。
面番号Ｒ(mm) Ｄ(mm) Ｎｄ νｄ有効半径(mm)
１ 18.829 0.90 1.9229 20.9 7.93
２ 13.684 3.09 1.7292 54.7 7.41
３(＊) 4634.800 ｄ１ 7.10
４ -103.060 0.70 1.9014 31.6 4.44
５ 4.897 2.56 3.33
６ -13.301 0.70 1.6385 55.5 3.12
７ 6.886 1.62 1.9229 20.9 3.05
８ 186.217 ｄ２ 2.95
９(絞り) ∞ 0.80 1.87
10(＊) 5.406 2.50 1.5831 59.4 2.24
11(＊) -23.224 0.37 2.23
12 10.799 1.50 1.4970 81.6 2.22
13 -11.436 0.80 1.9014 31.6 2.13
14 4.000 1.80 1.5955 39.2 2.09
15 -30.119 ｄ３ 2.20
16(＊) 16.774 1.59 1.5305 56.0 3.38
17(＊) 161.606 ｄ４ 3.64
18 ∞ 1.50 1.5168 64.2 3.70
19 ∞ 3.70
・非球面係数を以下に示す。
第３面
K=0.0000E+00,A4=0.5937E-05,A6=0.1093E-06,A8=-0.4400E-08,A10=0.7900E-10,A12=-0.1000E-11
第10面
K=-0.1131E+00,A4=0.5722E-06,A6=0.1520E-04,A8=0.2863E-05,A10=0.1283E-06
第11面
K=0.0000E+00,A4=0.8801E-03,A6=0.2370E-04,A8=0.6091E-05,A10=0.2129E-06
第16面
K=0.0000E+00,A4=-0.2091E-02,A6=-0.7162E-04,A8=-0.3459E-05
第17面
K=0.0000E+00,A4=-0.2128E-02,A6=-0.5597E-04,A8=-0.1980E-05,A10=0.6275E-07
・変倍時の各種データを以下に示す。 f 4.0 ~ 12.7 ~ 40.0
F 3.51 ~ 4.88 ~ 5.8
fB 1.0
2ω 80 ° -30 ° -10 °
・ Lens surface data is shown below.
Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 18.829 0.90 1.9229 20.9 7.93
2 13.684 3.09 1.7292 54.7 7.41
3 (*) 4634.800 d1 7.10
4 -103.060 0.70 1.9014 31.6 4.44
5 4.897 2.56 3.33
6 -13.301 0.70 1.6385 55.5 3.12
7 6.886 1.62 1.9229 20.9 3.05
8 186.217 d2 2.95
9 (Aperture) ∞ 0.80 1.87
10 (*) 5.406 2.50 1.5831 59.4 2.24
11 (*) -23.224 0.37 2.23
12 10.799 1.50 1.4970 81.6 2.22
13 -11.436 0.80 1.9014 31.6 2.13
14 4.000 1.80 1.5955 39.2 2.09
15 -30.119 d3 2.20
16 (*) 16.774 1.59 1.5305 56.0 3.38
17 (*) 161.606 d4 3.64
18 ∞ 1.50 1.5168 64.2 3.70
19 ∞ 3.70
・ Aspheric coefficient is shown below.
Third side
K = 0.0000E + 00, A4 = 0.5937E-05, A6 = 0.1093E-06, A8 = -0.4400E-08, A10 = 0.7900E-10, A12 = -0.1000E-11
10th page
K = -0.1131E + 00, A4 = 0.5722E-06, A6 = 0.1520E-04, A8 = 0.2863E-05, A10 = 0.1283E-06
11th page
K = 0.0000E + 00, A4 = 0.8801E-03, A6 = 0.2370E-04, A8 = 0.6091E-05, A10 = 0.2129E-06
16th page
K = 0.0000E + 00, A4 = -0.2091E-02, A6 = -0.7162E-04, A8 = -0.3459E-05
17th page
K = 0.0000E + 00, A4 = -0.2128E-02, A6 = -0.5597E-04, A8 = -0.1980E-05, A10 = 0.6275E-07
-Various data at the time of zooming are shown below.

ｆＦｄ１ｄ２ｄ３ｄ４
4.00 3.51 0.81 12.64 2.84 3.29
12.66 4.88 7.53 4.41 4.94 7.57
40.00 5.80 15.52 0.99 11.13 5.90
・レンズ群データを以下に示す。
レンズ群始面焦点距離(mm)
１１ 28.54
２４ -4.82
３９ 9.17
４ 16 35.15
・前述の各条件式に対応する値を以下に示す。 f F d1 d2 d3 d4
4.00 3.51 0.81 12.64 2.84 3.29
12.66 4.88 7.53 4.41 4.94 7.57
40.00 5.80 15.52 0.99 11.13 5.90
・ Lens group data is shown below.
Lens group Start surface Focal length (mm)
1 1 28.54
2 4 -4.82
3 9 9.17
4 16 35.15
-Values corresponding to the above conditional expressions are shown below.

条件式(１)＝0.404
条件式(２)＝0.306
条件式(３)＝0.725
条件式(４)＝0.848
条件式(５)＝-0.381
なお、図９はズームレンズの構成図であり、主要な構成は実施例１と同様である。 Conditional expression (1) = 0.404
Conditional expression (2) = 0.306
Conditional expression (3) = 0.725
Conditional expression (4) = 0.848
Conditional expression (5) =-0.381
FIG. 9 is a configuration diagram of the zoom lens, and the main configuration is the same as that of the first embodiment.

図１０はズームレンズの広角端における収差図、図１１はズームレンズの中間焦点距離における収差図、図１２はズームレンズの望遠端における収差図である。
［実施例４］
・全体諸元を以下に示す。 10 is an aberration diagram at the wide-angle end of the zoom lens, FIG. 11 is an aberration diagram at the intermediate focal length of the zoom lens, and FIG. 12 is an aberration diagram at the telephoto end of the zoom lens.
[Example 4]
・ The overall specifications are shown below.

ｆ 3.8〜12.0〜38.0
Ｆ 3.02〜4.47〜5.8
ｆＢ 1.0
２ω 80°〜30°〜10°
・レンズ面データを以下に示す。
面番号Ｒ(mm) Ｄ(mm) Ｎｄ νｄ有効半径(mm)
１ 55.335 0.80 1.9229 20.9 7.14
２ 25.237 1.95 1.7292 54.7 6.61
３ -354.920 0.10 6.15
４ 22.708 1.70 1.7292 54.7 6.03
５ 168.422 ｄ１ 5.85
６ -32.140 0.60 1.8830 40.8 3.65
７ 4.800 2.27 2.88
８ -9.789 0.50 1.5407 47.2 2.71
９ 7.241 1.45 1.9229 20.9 2.69
10 822.945 ｄ２ 2.60
11(絞り) ∞ 0.72 1.95
12 5.694 1.68 1.6180 63.4 2.24
13 -105.123 0.10 2.22
14 4.424 1.95 1.4970 81.6 2.18
15 -18.359 0.50 1.9037 31.3 1.91
16 3.086 1.43 1.5927 35.5 1.74
17(＊) 19.887 ｄ３ 1.70
18(＊) -92.477 1.60 1.5305 56.0 3.04
19(＊) -13.829 ｄ４ 3.36
20 ∞ 1.50 1.5168 64.2 3.50
21 ∞ 3.50
・非球面係数を以下に示す。
第17面
K=0.0000E+00,A4=0.3669E-02,A6=0.1560E-03,A8=0.1868E-04
第18面
K=0.0000E+00,A4=-0.2758E-02,A6=-0.7298E-04,A8=-0.8360E-05
第19面
K=0.0000E+00,A4=-0.2482E-02,A6=-0.6879E-04,A8=-0.2763E-05
・変倍時の各種データを以下に示す。 f 3.8-12.0-38.0
F 3.02 ~ 4.47 ~ 5.8
fB 1.0
2ω 80 ° -30 ° -10 °
・ Lens surface data is shown below.
Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 55.335 0.80 1.9229 20.9 7.14
2 25.237 1.95 1.7292 54.7 6.61
3 -354.920 0.10 6.15
4 22.708 1.70 1.7292 54.7 6.03
5 168.422 d1 5.85
6 -32.140 0.60 1.8830 40.8 3.65
7 4.800 2.27 2.88
8 -9.789 0.50 1.5407 47.2 2.71
9 7.241 1.45 1.9229 20.9 2.69
10 822.945 d2 2.60
11 (Aperture) ∞ 0.72 1.95
12 5.694 1.68 1.6180 63.4 2.24
13 -105.123 0.10 2.22
14 4.424 1.95 1.4970 81.6 2.18
15 -18.359 0.50 1.9037 31.3 1.91
16 3.086 1.43 1.5927 35.5 1.74
17 (*) 19.887 d3 1.70
18 (*) -92.477 1.60 1.5305 56.0 3.04
19 (*) -13.829 d4 3.36
20 ∞ 1.50 1.5168 64.2 3.50
21 ∞ 3.50
・ Aspheric coefficient is shown below.
17th page
K = 0.0000E + 00, A4 = 0.3669E-02, A6 = 0.1560E-03, A8 = 0.1868E-04
18th page
K = 0.0000E + 00, A4 = -0.2758E-02, A6 = -0.7298E-04, A8 = -0.8360E-05
19th page
K = 0.0000E + 00, A4 = -0.2482E-02, A6 = -0.6879E-04, A8 = -0.2763E-05
-Various data at the time of zooming are shown below.

ｆＦｄ１ｄ２ｄ３ｄ４
3.80 3.02 0.75 10.70 1.89 2.72
12.02 4.47 5.92 3.06 2.76 7.87
38.00 5.80 13.81 0.60 12.54 2.69
・レンズ群データを以下に示す。
レンズ群始面焦点距離(mm)
１１ 25.95
２６ -4.68
３ 11 7.62
４ 18 30.44
・前述の各条件式に対応する値を以下に示す。 f F d1 d2 d3 d4
3.80 3.02 0.75 10.70 1.89 2.72
12.02 4.47 5.92 3.06 2.76 7.87
38.00 5.80 13.81 0.60 12.54 2.69
・ Lens group data is shown below.
Lens group Start surface Focal length (mm)
1 1 25.95
2 6 -4.68
3 11 7.62
4 18 30.44
-Values corresponding to the above conditional expressions are shown below.

条件式(１)＝0.407
条件式(２)＝0.311
条件式(３)＝0.634
条件式(４)＝1.154
条件式(５)＝-0.39
なお、図１３はズームレンズの構成図であり、主要な構成は実施例１と同様であるが、第１レンズ群Ｇｒ１が物体側より順に負レンズ、正レンズ及び正レンズから構成される点のみが実施例１と相違する。 Conditional expression (1) = 0.407
Conditional expression (2) = 0.311
Conditional expression (3) = 0.634
Conditional expression (4) = 1.154
Conditional expression (5) = -0.39
FIG. 13 is a configuration diagram of the zoom lens, and the main configuration is the same as that of the first embodiment, but only the first lens group Gr1 is composed of a negative lens, a positive lens, and a positive lens in order from the object side. Is different from the first embodiment.

図１４はズームレンズの広角端における収差図、図１５はズームレンズの中間焦点距離における収差図、図１６はズームレンズの望遠端における収差図である。
［実施例５］
・全体諸元を以下に示す。 FIG. 14 is an aberration diagram at the wide-angle end of the zoom lens, FIG. 15 is an aberration diagram at the intermediate focal length of the zoom lens, and FIG. 16 is an aberration diagram at the telephoto end of the zoom lens.
[Example 5]
・ The overall specifications are shown below.

ｆ 4.7〜14.9〜47.0
Ｆ 3.6〜5.24〜5.8
ｆＢ 1.0
２ω 80°〜30°〜10°
・レンズ面データを以下に示す。
面番号Ｒ(mm) Ｄ(mm) Ｎｄ νｄ有効半径(mm)
１ 18.701 0.90 1.9229 20.9 8.16
２ 13.884 3.59 1.6940 56.3 7.43
３(＊) -207.738 ｄ１ 7.00
４ -58.034 0.70 1.9037 31.3 4.80
５ 6.012 2.78 3.74
６ -11.511 0.60 1.5168 64.2 3.51
７ 7.874 0.20 3.43
８ 8.407 1.57 1.9229 20.9 3.46
９ 63.894 ｄ２ 3.35
10(絞り) ∞ 0.80 2.01
11 5.280 1.78 1.5691 71.3 2.46
12 87.409 0.22 2.44
13 5.385 2.67 1.4970 81.6 2.44
14 -7.378 0.50 1.8830 40.8 2.14
15 4.275 1.28 1.5225 62.3 2.05
16(＊) 37.480 ｄ３ 2.10
17(＊) 24.836 1.57 1.5305 56.0 3.74
18(＊) -43.330 ｄ４ 3.95
19 ∞ 1.50 1.5168 64.2 4.00
20 ∞ 4.00
・非球面係数を以下に示す。
第３面
K=0.0000E+00,A4=0.1242E-04,A6=0.1048E-07,A8=-0.1427E-08,A10=0.3100E-10
第16面
K=0.0000E+00,A4=0.4105E-02,A6=0.2036E-03,A8=0.1343E-04
第17面
K=0.0000E+00,A4=-0.1002E-02,A6=0.4461E-04,A8=-0.5777E-05
第18面
K=0.0000E+00,A4=-0.1490E-02,A6=0.2940E-04,A8=-0.4445E-05,A10=0.2299E-07
・変倍時の各種データを以下に示す。 f 4.7-14.9-47.0
F 3.6〜5.24〜5.8
fB 1.0
2ω 80 ° -30 ° -10 °
・ Lens surface data is shown below.
Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 18.701 0.90 1.9229 20.9 8.16
2 13.884 3.59 1.6940 56.3 7.43
3 (*) -207.738 d1 7.00
4 -58.034 0.70 1.9037 31.3 4.80
5 6.012 2.78 3.74
6 -11.511 0.60 1.5168 64.2 3.51
7 7.874 0.20 3.43
8 8.407 1.57 1.9229 20.9 3.46
9 63.894 d2 3.35
10 (Aperture) ∞ 0.80 2.01
11 5.280 1.78 1.5691 71.3 2.46
12 87.409 0.22 2.44
13 5.385 2.67 1.4970 81.6 2.44
14 -7.378 0.50 1.8830 40.8 2.14
15 4.275 1.28 1.5225 62.3 2.05
16 (*) 37.480 d3 2.10
17 (*) 24.836 1.57 1.5305 56.0 3.74
18 (*) -43.330 d4 3.95
19 ∞ 1.50 1.5168 64.2 4.00
20 ∞ 4.00
・ Aspheric coefficient is shown below.
Third side
K = 0.0000E + 00, A4 = 0.1242E-04, A6 = 0.1048E-07, A8 = -0.1427E-08, A10 = 0.3100E-10
16th page
K = 0.0000E + 00, A4 = 0.4105E-02, A6 = 0.2036E-03, A8 = 0.1343E-04
17th page
K = 0.0000E + 00, A4 = -0.1002E-02, A6 = 0.4461E-04, A8 = -0.5777E-05
18th page
K = 0.0000E + 00, A4 = -0.1490E-02, A6 = 0.2940E-04, A8 = -0.4445E-05, A10 = 0.2299E-07
-Various data at the time of zooming are shown below.

ｆＦｄ１ｄ２ｄ３ｄ４
4.70 3.60 0.72 14.11 2.77 3.21
14.86 5.24 6.47 4.88 4.56 8.25
47.00 5.80 14.92 1.03 11.20 3.21
・レンズ群データを以下に示す。
レンズ群始面焦点距離(mm)
１１ 27.57
２４ -5.50
３ 10 9.43
４ 17 30.00
・前述の各条件式に対応する値を以下に示す。 f F d1 d2 d3 d4
4.70 3.60 0.72 14.11 2.77 3.21
14.86 5.24 6.47 4.88 4.56 8.25
47.00 5.80 14.92 1.03 11.20 3.21
・ Lens group data is shown below.
Lens group Start surface Focal length (mm)
1 1 27.57
2 4 -5.50
3 10 9.43
4 17 30.00
-Values corresponding to the above conditional expressions are shown below.

条件式(１)＝0.386
条件式(２)＝0.361
条件式(３)＝0.634
条件式(４)＝1.039
条件式(５)＝-0.37
なお、図１７はズームレンズの構成図であり、主要な構成は実施例１と同様である。 Conditional expression (1) = 0.386
Conditional expression (2) = 0.361
Conditional expression (3) = 0.634
Conditional expression (4) = 1.039
Conditional expression (5) = -0.37
FIG. 17 is a configuration diagram of the zoom lens, and the main configuration is the same as that of the first embodiment.

図１８はズームレンズの広角端における収差図、図１９はズームレンズの中間焦点距離における収差図、図２０はズームレンズの望遠端における収差図である。 18 is an aberration diagram at the wide-angle end of the zoom lens, FIG. 19 is an aberration diagram at the intermediate focal length of the zoom lens, and FIG. 20 is an aberration diagram at the telephoto end of the zoom lens.

Ｇｒ１第１レンズ群
Ｇｒ２第２レンズ群
Ｇｒ３第３レンズ群
Ｇｒ４第４レンズ群
Ｇｒ３ａ第３ａレンズ群
Ｇｒ３ｂ第３ｂレンズ群
Ｓ開口絞り Gr1 1st lens group Gr2 2nd lens group Gr3 3rd lens group Gr4 4th lens group Gr3a 3a lens group Gr3b 3b lens group S Aperture stop

Claims

In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a positive refractive power. A zoom lens configured to perform zooming by moving the first lens group, the second lens group, the third lens group, and the fourth lens group in the optical axis direction by changing an air interval of each lens group. In
The first lens group includes a negative lens and a positive lens in order from the object side,
The second lens group includes, in order from the object side, a negative lens, a negative lens, and a positive lens.
The third lens group includes, in order from the object side, a 3a lens group including one positive lens, and a 3b lens group including three cemented lenses of a positive lens, a negative lens, and a positive lens.
A zoom lens satisfying the following conditional expression:
0.1 <n3b2-n3b1 <0.7
0.1 <n3b2-n3b3 <0.7
However,
n3b1: Refractive index with respect to the d-line of the positive lens located closest to the object side of the 3b lens group n3b2: Refractive index with respect to the d-line of the negative lens located in the middle of the 3b lens group n3b3: of the 3b lens group Refractive index for d-line of the positive lens located closest to the image

The zoom lens according to claim 1, wherein the following condition is satisfied.
0.4 <f3 / (fW × fT) ^1/2 <1.0
0.6 <f3a / f3 <2.0
However,
f3: focal length of the third lens group fW: focal length of the entire system at the wide angle end fT: focal length of the entire system at the telephoto end f3a: focal length of the third lens group

The zoom lens according to claim 1, wherein the second lens group satisfies the following condition.
−0.6 <f2 / (fW × fT) ^1/2 <−0.2
However,
f2: focal length of the second lens group fW: focal length of the entire system at the wide angle end fT: focal length of the entire system at the telephoto end

The said 2nd lens group is comprised from 2 groups 3 pieces which consist of a negative lens and the cemented lens of a negative lens and a positive lens in order from an object side. Zoom lens described in 1.

The zoom lens according to claim 1, wherein the third lens group has at least one aspheric surface.

The zoom lens according to claim 1, wherein the fourth lens group includes one positive lens and has at least one aspheric surface.

The first lens group includes two lenses including a negative lens and a positive lens in order from the object side, and has at least one aspheric surface. Zoom lens described in 1.

The zoom lens according to claim 1, wherein the first lens group includes three lenses including a negative lens, a positive lens, and a positive lens in order from the object side. .