JPH06289295A - Zoom lens - Google Patents
Zoom lensInfo
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- JPH06289295A JPH06289295A JP8053593A JP8053593A JPH06289295A JP H06289295 A JPH06289295 A JP H06289295A JP 8053593 A JP8053593 A JP 8053593A JP 8053593 A JP8053593 A JP 8053593A JP H06289295 A JPH06289295 A JP H06289295A
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、ズームレンズに関し、
特に、ビデオカメラやスチルビデオカメラ等に適した高
変倍比のインナーフォーカス方式のズームレンズに関す
るものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zoom lens,
In particular, the present invention relates to a high zoom ratio inner focus type zoom lens suitable for video cameras, still video cameras, and the like.
【０００２】[0002]
【従来の技術】従来より、ビデオカメラ等に用いられる
撮影レンズに対しては、変倍比が大きく小型で高性能な
レンズ系であることが要求されている。2. Description of the Related Art Conventionally, it has been required for a taking lens used in a video camera or the like to be a lens system having a large zoom ratio and a small size and high performance.
【０００３】このようなレンズ系を達成する手段とし
て、物体側より順に、正の屈折力を持つ第１レンズ群、
負の屈折力を持ち変倍作用を持つ第２レンズ群、負の屈
折力を持ち変倍に際して像面を一定に保つ作用を持つ第
３レンズ群、正の屈折力を持ち結像作用を持つ第４レン
ズ群からなる４群ズームレンズがよく知られている。As a means for achieving such a lens system, a first lens group having a positive refractive power in order from the object side,
The second lens group having negative refracting power and zooming action, the third lens group having negative refracting power and keeping the image surface constant during zooming, and the positive lensing power having imaging action A 4-group zoom lens including a fourth lens group is well known.
【０００４】このタイプにおいて、代表的な第４レンズ
群の構成には、例えば図１９に示す特公昭４６−２５７
７９号において知られるように、第３レンズ群ＩＩＩか
らの発散光束をほぼアフォーカルにする作用を持つ前群
ＩＶF とその光束を収束するための作用を持つ後群ＩＶ
R とからなり、前群ＩＶF と後群ＩＶR が比較的長い空
気間隔をおいて配置されたものがある。第４レンズ群を
球面レンズで構成する場合、上記構成のレンズ系で十分
な光学性能を得るには、第４レンズ群ＩＶが少なくとも
６〜７枚のレンズを有することが必要である。In this type, a typical construction of the fourth lens group is, for example, Japanese Patent Publication No. 46-257 shown in FIG.
As is known in No. 79, the front group IV F having a function of making the divergent light flux from the third lens group III almost afocal and the rear group IV F having a function of converging the light flux.
Consists of a R, there is the front group IV F and the rear group IV R is disposed at a relatively long air interval. When the fourth lens group is composed of a spherical lens, it is necessary for the fourth lens group IV to have at least 6 to 7 lenses in order to obtain sufficient optical performance in the lens system having the above configuration.
【０００５】上記タイプで、レンズ全長を短縮するため
には、第４レンズ群をコンパクトに構成することが望ま
れる。しかし、収差補正上、球面レンズのみでこれを達
成することは困難であり、そのため、非球面を用いるこ
とが、特開平２−２０８６２０号や特開平４−１８６２
１０号等で知られている。これらの例では、非球面を用
いることで、レンズ全長を短縮しレンズ系のコンパクト
化を図ったものであるが、フォーカシングを第１レンズ
群で行うため、第１レンズ群のレンズ径を大きくする必
要があり、このため第１レンズ群の重量が増し駆動機構
への負担が大きくなることから、小型軽量化の点で好ま
しくない。In order to shorten the total lens length of the above type, it is desirable to make the fourth lens group compact. However, in terms of aberration correction, it is difficult to achieve this with only a spherical lens, and therefore it is recommended to use an aspherical surface as disclosed in JP-A-2-208620 and JP-A-4-1862.
It is known as No. 10. In these examples, by using an aspherical surface, the overall lens length is shortened and the lens system is made compact, but since the focusing is performed by the first lens group, the lens diameter of the first lens group is increased. Since it is necessary to increase the weight of the first lens group and increase the load on the drive mechanism, it is not preferable in terms of size reduction and weight reduction.
【０００６】上記タイプに用いられるフォーカシング方
式としては、大別して、第１レンズ群でフォーカシング
を行うものと、内部のレンズ群を移動させるインナーフ
ォーカス方式とが従来より知られている。インナーフォ
ーカス方式は、第１レンズ群の径や重量を前者のタイプ
のレンズ系よりも小さくすることができ、レンズ系の小
型軽量化には有利である。Focusing methods used in the above-mentioned types are roughly classified into a focusing method which uses a first lens group and an inner focusing method which moves an internal lens group. The inner focus method can make the diameter and weight of the first lens group smaller than that of the former type lens system, and is advantageous for reducing the size and weight of the lens system.
【０００７】上記タイプのズームレンズに用いられるイ
ンナーフォーカス方式として、第１レンズ群を固定し、
第２レンズ群のズーミング作用による像面移動を第３レ
ンズ群で補正すると共に、このレンズ群でフォーカシン
グを行うものや、第４レンズ群内の一部のレンズを移動
させてフォーカシングを行うものが知られている。しか
し、第４レンズ群内の一部のレンズを移動させてフォー
カシングを行う場合、ズーミングのための駆動機構とは
別の駆動機構を新たに設ける必要があるため、第３レン
ズ群を移動してフォーカシングを行う場合よりも、小型
軽量化の点で不利である。As an inner focus system used in the above type of zoom lens, the first lens group is fixed,
An image plane movement caused by the zooming action of the second lens group is corrected by the third lens group, focusing is performed by this lens group, and some of the lenses in the fourth lens group are moved to perform focusing. Are known. However, when focusing is performed by moving a part of the lenses in the fourth lens group, it is necessary to newly provide a driving mechanism different from the driving mechanism for zooming. It is disadvantageous in that it is smaller and lighter than the case of performing focusing.
【０００８】上記構成のレンズ系に非球面を採用し、ま
た、第３レンズ群を駆動するインナーフォーカス方式を
用いた例として、特開昭５９−３１９２０号のものがあ
る。しかし、この例では、非球面を用いているにもかか
わらず、第４レンズ群においてレンズ枚数を８枚も用い
ており、コンパクト化の点で好ましくない。また、第２
レンズ群と第３レンズ群の望遠端での群間隔を十分にと
っていないため、第３レンズ群を物体側に移動して至近
距離物点へフォーカシングすることは不可能である。As an example in which an aspherical surface is adopted in the lens system having the above construction and an inner focus system for driving the third lens group is used, there is JP-A-59-31920. However, in this example, even though the aspherical surface is used, as many as eight lenses are used in the fourth lens group, which is not preferable in terms of compactness. Also, the second
Since the distance between the lens group and the third lens group at the telephoto end is not sufficient, it is impossible to move the third lens group to the object side and focus on a close-range object point.
【０００９】[0009]
【発明が解決しようとする課題】本発明は以上のような
従来技術の問題点に鑑みてなされたものであり、その目
的は、ビデオカメラやスチルビデオカメラ等に適した４
群ズームレンズにおいて、非球面レンズを適用すること
によって、小型で高い光学性能を有する変倍比８倍程度
のインナーフォーカス方式のズームレンズを提供するこ
とである。SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the prior art as described above, and an object thereof is to be suitable for a video camera, a still video camera and the like.
By applying an aspherical lens to the group zoom lens, it is possible to provide a small-sized inner focus type zoom lens having high optical performance and a variable power ratio of about 8 times.
【００１０】[0010]
【課題を解決するための手段】上記目的を達成する本発
明のズームレンズは、物体側より順に、正の屈折力を持
ちズーミングに際して固定の第１レンズ群、負の屈折力
を持ちズーミングに際して光軸上を前後に移動して変倍
作用を持つ第２レンズ群、負の屈折力を持ちズーミング
に際して光軸上を前後に移動して像面を一定に保つ作用
を持つ第３レンズ群、正の屈折力を持ちズーミングに際
して固定の第４レンズ群からなり、第４レンズ群が少な
くともその１面が非球面であるレンズを少なくとも１枚
含み、第２レンズ群を少なくとも２枚のレンズで構成
し、第３レンズ群を物体側に繰り出すことによって近距
離物点へフォーカシングを行い、かつ、以下の条件
（１）を満足することを特徴とするものである。 （１） Ｄ2T／ｆT ＞０．０８ ただし、Ｄ2Tは物点が無限遠のときの望遠端における第
２レンズ群と第３レンズ群の間隔、ｆT は望遠端での全
系の焦点距離である。A zoom lens system according to the present invention which achieves the above object comprises, in order from the object side, a first lens group having a positive refracting power and fixed during zooming, and a negative lens having a negative refracting power and an optical system during zooming. A second lens group that moves back and forth on the axis to have a zooming effect, and a third lens group that has a negative refractive power and moves back and forth on the optical axis during zooming to keep the image surface constant, and a positive lens group. A fourth lens group having a refractive power of 4 and fixed during zooming, the fourth lens group includes at least one lens having at least one aspherical surface, and the second lens group includes at least two lenses. , The third lens group is extended to the object side to perform focusing on a short-distance object point, and the following condition (1) is satisfied. (1) D 2T / f T > 0.08 where D 2T is the distance between the second lens group and the third lens group at the telephoto end when the object point is infinity, and f T is the total system at the telephoto end. The focal length.
【００１１】[0011]
【作用】以下、上記構成をとる理由と作用について説明
する。レンズ全長の短縮化に非球面を用いると効果的で
あることは従来より知られているが、本発明のタイプの
ズームレンズに非球面を適用してレンズ全長を短縮化す
るには、正の屈折力を有する第４レンズ群に少なくとも
１面が非球面であるレンズを用いることが好ましい。The function and operation of the above configuration will be described below. It has been conventionally known that it is effective to use an aspherical surface for shortening the total lens length, but in order to reduce the total lens length by applying an aspherical surface to a zoom lens of the type of the present invention, a positive lens is used. It is preferable to use a lens having at least one aspherical surface in the fourth lens group having a refractive power.
【００１２】図１９に示す構成のレンズ系において、レ
ンズ全長を短縮化するには、第４レンズ群をより短い構
成とすることが考えられる。しかし、レンズ枚数を増や
さずにこれを達成するには、第４レンズ群内の各レンズ
の屈折力を強くする必要があり、このため、第４レンズ
群での収差が悪化する。In the lens system having the structure shown in FIG. 19, in order to shorten the total lens length, it is conceivable to make the fourth lens group shorter. However, in order to achieve this without increasing the number of lenses, it is necessary to increase the refracting power of each lens in the fourth lens group, which causes the aberration in the fourth lens group to deteriorate.
【００１３】通常、ズームレンズにおいては、ズーミン
グにおけるレンズ全系の収差変動を最小限に抑えるた
め、各群で諸収差を補正することが望ましく、本発明の
レンズ系においても、第４レンズ群で発生する収差はこ
の群で補正することが望ましい。そのため、本発明のレ
ンズ系においては、第４レンズ群に非球面を適用するこ
とが望ましい。第４レンズ群に非球面を採用することに
よって、第４レンズ群の屈折力を強めたために発生する
収差を第４レンズ群内で補正することができるようにな
る。Usually, in a zoom lens, it is desirable to correct various aberrations in each group in order to minimize the aberration variation of the entire lens system during zooming. In the lens system of the present invention, the fourth lens group is also used. It is desirable that this group corrects the generated aberration. Therefore, in the lens system of the present invention, it is desirable to apply an aspherical surface to the fourth lens group. By adopting an aspherical surface in the fourth lens group, it becomes possible to correct the aberration generated in the fourth lens group due to the increased refractive power of the fourth lens group.
【００１４】また、本発明のレンズ系においては、変倍
に伴う第２レンズ群の移動距離を短くするために、第２
レンズ群の負の屈折力が強く、この群で発生する収差が
大きくなる傾向にある。特に、第２レンズ群で発生する
色収差の発生量が大きくなり、これを補正するために、
第２レンズ群は少なくとも１枚の正レンズと少なくとも
１枚の負レンズで構成することが必要である。Further, in the lens system of the present invention, in order to shorten the moving distance of the second lens unit due to the magnification change,
The negative refracting power of the lens group is strong, and the aberration generated in this group tends to be large. In particular, the amount of chromatic aberration generated in the second lens group becomes large, and in order to correct this,
The second lens group must be composed of at least one positive lens and at least one negative lens.
【００１５】また、本発明のレンズ系においては、第２
レンズ群のズーミング作用による像面移動を第３レンズ
群で補正すると共に、このレンズ群でフォーカシングを
行うインナーフォーカス方式を採用することが、レンズ
系の小型軽量化の点で望ましい。In the lens system of the present invention, the second
It is desirable from the viewpoint of downsizing and weight saving of the lens system that the third lens group corrects the image plane movement due to the zooming action of the lens group and the focusing is performed by this lens group.
【００１６】また、第３レンズ群でフォーカシングを行
う場合には、特に望遠端における１ｍ程度の至近距離物
点へのフォーカシングの際に、第２レンズ群と第３レン
ズ群が接触しない程度に群間隔を調整する必要がある。
そこで、本発明のレンズ系では以下の条件（１）を満足
するようにしている。When focusing is performed by the third lens group, the second lens group and the third lens group do not come into contact with each other when focusing on an object at a close range of about 1 m at the telephoto end. The spacing needs to be adjusted.
Therefore, the lens system of the present invention is designed to satisfy the following condition (1).
【００１７】（１） Ｄ2T／ｆT ＞０．０８ 本発明のレンズ系において、望遠端における第２レンズ
群と第３レンズ群の群間隔が条件（１）を満足していれ
ば、至近距離物点にフォーカスすることが可能である。
もし、条件（１）を満足しないでＤ2T／ｆT が０．０８
以下の場合、至近距離物点にフォーカスするためは、第
３レンズ群の屈折力を強くすることが必要となり、この
群で発生する諸収差が増大し、フォーカシングの際の収
差変動が大きくなるため、好ましくない。(1) D 2T / f T > 0.08 In the lens system of the present invention, if the distance between the second lens unit and the third lens unit at the telephoto end satisfies the condition (1), it is very close. It is possible to focus on a distance object point.
If the condition (1) is not satisfied, D 2T / f T is 0.08
In the following cases, in order to focus on the object point at the closest distance, it is necessary to increase the refractive power of the third lens group, the various aberrations generated in this group increase, and the aberration fluctuation during focusing increases. , Not preferable.
【００１８】本発明に用いられる非球面は次の式（ａ）
にて表される。 上記式（ａ）は、ｘ軸を光軸方向にとり、ｙ軸を光軸と
直角方向にとったもので、ｒは光軸上の曲率半径、Ａ2i
は非球面係数である。The aspherical surface used in the present invention has the following formula (a).
It is represented by. The above equation (a) is obtained by taking the x-axis in the optical axis direction and the y-axis in the direction perpendicular to the optical axis, and r is the radius of curvature on the optical axis, A 2i
Is an aspherical coefficient.
【００１９】レンズ全長を短くするために、第４レンズ
群の各レンズの屈折力を強めると、第３レンズ群からの
発散光束が第４レンズ群の物体側の正レンズにより急激
に収束させられるため、第４レンズ群では大きな負の球
面収差が発生する。レンズ枚数を増やさずにこれを補正
するには、少なくとも１面が以下の条件（２）を満足す
る非球面であるレンズを第４レンズ群内に少なくとも１
枚用いることが望ましい。When the refractive power of each lens of the fourth lens group is increased in order to shorten the total lens length, the divergent light beam from the third lens group is rapidly converged by the positive lens on the object side of the fourth lens group. Therefore, large negative spherical aberration occurs in the fourth lens group. In order to correct this without increasing the number of lenses, at least one lens whose at least one surface is an aspherical surface satisfying the following condition (2) is included in the fourth lens group at least 1
It is desirable to use one.
【００２０】（２） Ａ4 ＜０ （ｎa −ｎa ' ＜
０）， Ａ4 ＞０ （ｎa −ｎa ' ＞０） ただし、ｎa は非球面を用いた面を通過する光線の入射
側媒質の屈折率、ｎa 'は非球面を用いた面を通過する
光線の出射側媒質の屈折率である。(2) A 4 <0 (n a −n a '<
0), A 4 > 0 (n a −n a ′> 0), where n a is the refractive index of the incident side medium of the ray passing through the surface using the aspherical surface, and n a ′ is the surface using the aspherical surface Is the refractive index of the exit side medium of the light beam passing through.
【００２１】条件（２）は、非球面形状を表す式（ａ）
の４次の領域で、例えば非球面を正レンズに用いる場
合、その形状は光軸から周辺に行くに従って正の屈折力
が小さくなるような形状となることを表し、また、非球
面を用いる面が例えば負レンズである場合、その形状が
光軸から周辺に行くに従って負の屈折力が大きくなるよ
うな形状となることを表している。The condition (2) is the expression (a) representing the aspherical shape.
In the fourth-order region of, for example, when an aspherical surface is used as a positive lens, the shape is such that the positive refracting power becomes smaller from the optical axis toward the periphery. Indicates that, for example, a negative lens has a shape in which the negative refracting power increases as it goes from the optical axis to the periphery.
【００２２】本発明のレンズ系において、少なくともそ
の１面が条件（２）を満足する非球面であるレンズを第
４レンズ群が少なくとも１枚有していれば、この群で発
生する負の球面収差を良好に補正することができる。条
件（２）を満足しないと、第４レンズ群で発生する負の
球面収差をさらに助長させるため、好ましくない。In the lens system of the present invention, if the fourth lens group has at least one lens whose at least one surface is an aspherical surface satisfying the condition (2), a negative spherical surface generated in this group. Aberration can be corrected well. If the condition (2) is not satisfied, the negative spherical aberration generated in the fourth lens group is further promoted, which is not preferable.
【００２３】本発明のレンズ系で、広角端から望遠端に
わたってバランスよく収差補正を行うには、各群の屈折
力を適当な値に保つ必要がある。そのためには、以下の
条件（３）を満足することが望ましい。 ただし、φW は広角端のレンズ全系の屈折力、φ1 、φ
2 、φ3 、φ4 はそれぞれ、第１、第２、第３、第４レ
ンズ群の屈折力である。In the lens system of the present invention, in order to perform well-balanced aberration correction from the wide-angle end to the telephoto end, it is necessary to maintain the refractive power of each group at an appropriate value. For that purpose, it is desirable to satisfy the following condition (3). Where φ W is the refractive power of the entire lens system at the wide-angle end, φ 1 , φ
2 , φ 3 , and φ 4 are the refracting powers of the first, second, third, and fourth lens groups, respectively.
【００２４】本発明のレンズ系の第１レンズ群では、こ
の群への入射光線高が高くなる望遠端での色収差の補正
が特に困難であるが、第１レンズ群の屈折力φ1 が条件
（３）の第１式を満足していれば、第１レンズ群内での
補正が可能である。もし、第１レンズ群の屈折力φ1 が
条件（３）の第１式の上限の０．５φW を越えてしまう
と、第１レンズ群内で発生する色収差を良好に補正する
ことが困難となる。また、下限の０．０５φW を越えて
しまうと、第１レンズ群の屈折力が弱くなり、レンズ全
系をコンパクトにすることが困難となる。In the first lens group of the lens system of the present invention, it is particularly difficult to correct chromatic aberration at the telephoto end where the height of the incident ray on this group becomes high, but the refractive power φ 1 of the first lens group is a condition. If the first expression of (3) is satisfied, correction within the first lens group is possible. If the refracting power φ 1 of the first lens group exceeds the upper limit of 0.5 φ W of the first expression of the condition (3), it is difficult to satisfactorily correct the chromatic aberration generated in the first lens group. Becomes If the lower limit of 0.05φ W is exceeded, the refractive power of the first lens group will be weakened, and it will be difficult to make the entire lens system compact.
【００２５】また、ズーミングの際に可動であり、変倍
に寄与する第２レンズ群のズーミングにおける移動量を
少なくし、レンズ全長をコンパクトに保つには、第２レ
ンズ群の屈折力を収差補正の可能な範囲で強くすること
が好ましい。このためには、第２レンズ群の屈折力φ2
が条件（３）の第２式を満足していることが望ましい。
もし、第２レンズ群の屈折力φ2 が条件（３）の第２式
の下限値の−φW を越えると、この群で発生する諸収差
を良好に補正することが困難となり、また、上限値の−
０．１φW を越えてしまうと、ズーミング時の移動量が
多くなり、レンズ全系をコンパクトにすることが困難と
なる。Further, in order to keep the total lens length compact by reducing the amount of movement of the second lens group, which is movable during zooming and contributes to zooming, during zooming, the refractive power of the second lens group is corrected by aberration. It is preferable to make it strong within the range of possible. For this purpose, the refractive power of the second lens group φ 2
Preferably satisfies the second expression of the condition (3).
If the refractive power φ 2 of the second lens group exceeds the lower limit value −φ W of the second expression of the condition (3), it becomes difficult to satisfactorily correct various aberrations generated in this group, and Of upper limit value
If it exceeds 0.1φ W , the amount of movement during zooming increases, and it becomes difficult to make the entire lens system compact.
【００２６】また、第３レンズ群はフォーカシング作用
を持つが、近距離物点へのフォーカシングに伴う収差変
動を最小に抑え、かつ、至近距離物点へのフォーカシン
グの移動量が極端に大きくならないようにするには、第
３レンズ群の屈折力φ3 が条件（３）の第３式を満足す
ることが好ましい。もし、第３レンズ群の屈折力φ3が
条件（３）の第３式の上限の−０．０７φW を越えてし
まうと、第３レンズ群で発生する諸収差を良好に補正す
ることが困難となり、フォーカシングの際の性能劣化が
大きくなる。また、下限値の−０．７φW を越えてしま
うと、至近距離物点へのフォーカシングの移動量が大き
くなるため、レンズ全系をコンパクトにすることが困難
となる。Further, although the third lens group has a focusing action, it suppresses aberration fluctuations due to focusing on a short-distance object point to a minimum and prevents the amount of focusing movement to a close-distance object point from becoming extremely large. In order to satisfy the above condition, it is preferable that the refractive power φ 3 of the third lens group satisfies the third expression of the condition (3). If the refractive power φ 3 of the third lens group exceeds the upper limit of −0.07 φ W of the third expression of the condition (3), it is possible to satisfactorily correct various aberrations generated in the third lens group. It becomes difficult, and the performance deterioration during focusing becomes large. On the other hand, if the lower limit of -0.7φ W is exceeded, the amount of focusing movement to the closest object point becomes large, and it becomes difficult to make the entire lens system compact.
【００２７】また、第４レンズ群で発生する諸収差を良
好に補正しつつ、第４レンズ群をコンパクトにするに
は、第４レンズ群の屈折力φ4 が条件（３）の第４式を
満足することが好ましい。もし、第４レンズ群の屈折力
φ4 が条件（３）の第４式の上限値のφW を越えてしま
うと、第４レンズ群で発生する諸収差を良好に補正する
ことが困難となり、また、下限値の０．１φW を越えて
しまうと、第４レンズ群をコンパクトな構成にすること
が困難となる。Further, in order to make the fourth lens group compact while satisfactorily correcting various aberrations occurring in the fourth lens group, the refractive power φ 4 of the fourth lens group should be the fourth expression of the condition (3). It is preferable to satisfy If the refractive power φ 4 of the fourth lens unit exceeds the upper limit φ W of the fourth expression of the condition (3), it becomes difficult to satisfactorily correct various aberrations generated in the fourth lens unit. If the lower limit of 0.1φ W is exceeded, it will be difficult to make the fourth lens group compact.
【００２８】以上のことから、本発明のレンズ系におい
て、全系をコンパクトに保ち、諸収差を良好に補正する
には、各群の屈折力が条件（３）を満足そることが望ま
しい。From the above, in the lens system of the present invention, it is desirable that the refractive power of each group should satisfy the condition (3) in order to keep the whole system compact and correct various aberrations well.
【００２９】また、本発明のレンズ系では、前述したよ
うに、第２レンズ群の負の屈折力が強く、この群で発生
する色収差が大きくなる傾向にある。本発明のレンズ系
でこれを良好に補正するには、第２レンズ群に少なくと
も１枚の正レンズを用いる必要があるが、この正レンズ
がさらに以下の条件（４）、（５）を満足することが好
ましい。 （４） ν2P＜４５ （５） ｜φ2P／φ2 ｜＞０．２ ただし、ν2Pは第２レンズ群に用いる正レンズのアッベ
数、φ2Pは第２レンズ群に用いる正レンズの屈折力、φ
2 は第２レンズ群の屈折力である。Further, in the lens system of the present invention, as described above, the negative refractive power of the second lens group is strong, and the chromatic aberration generated in this group tends to be large. In order to satisfactorily correct this with the lens system of the present invention, it is necessary to use at least one positive lens in the second lens group, and this positive lens further satisfies the following conditions (4) and (5). Preferably. (4) ν 2P <45 (5) | φ 2P / φ 2 |> 0.2 where ν 2P is the Abbe number of the positive lens used in the second lens group, and φ 2P is the positive lens used in the second lens group. Refractive power, φ
2 is the refractive power of the second lens group.
【００３０】第２レンズ群に用いる少なくとも１枚の正
レンズのアッベ数が条件（４）を満足すれば、第２レン
ズ群中の負レンズで発生する色収差を打ち消すことが可
能となる。また、第２レンズ群で発生する色収差を良好
に補正するには、条件（４）を満足する正レンズがさら
に条件（５）を満足することが望ましい。条件（４）を
満足する正レンズで第２レンズ群の色収差を良好に補正
するには、この正レンズの屈折力をある程度大きくする
ことが好ましい。条件（４）を満足する正レンズの屈折
力φ2Pが条件（５）を満足していれば、第２レンズ群の
正レンズの色収差は十分な発生量となり、第２レンズ群
中の負レンズで発生する色収差を打ち消すことができ
る。If the Abbe number of at least one positive lens used in the second lens group satisfies the condition (4), it is possible to cancel the chromatic aberration generated in the negative lens in the second lens group. Further, in order to satisfactorily correct the chromatic aberration generated in the second lens group, it is desirable that the positive lens satisfying the condition (4) further satisfy the condition (5). In order to satisfactorily correct the chromatic aberration of the second lens group with a positive lens that satisfies the condition (4), it is preferable to increase the refractive power of this positive lens to some extent. If the refractive power φ 2P of the positive lens satisfying the condition (4) satisfies the condition (5), the chromatic aberration of the positive lens in the second lens group becomes a sufficient amount, and the negative lens in the second lens group It is possible to cancel the chromatic aberration caused by.
【００３１】また、第３レンズ群からの発散光を良好な
光学性能を維持したまま第４レンズ群によって結像する
ためには、第４レンズ群を少なくとも３枚の正レンズと
少なくとも１枚の負レンズで構成することが好ましい。
諸収差、特に球面収差の補正に対しては、正レンズを少
なくとも３枚用いることが必要であり、また、色収差と
ペッツバール和を良好に補正するために、負レンズを少
なくとも１枚用いた構成とすることが望ましい。第４レ
ンズ群で発生する球面収差を良好に補正するには、第３
レンズ群からの光線を緩やかに収束させるために、第４
レンズ群中に少なくとも３枚の正レンズを用いることが
必要であり、これより少ない枚数で高い光学性能を得る
ことはできない。In order to form the divergent light from the third lens group by the fourth lens group while maintaining good optical performance, the fourth lens group should have at least three positive lenses and at least one positive lens. It is preferably composed of a negative lens.
It is necessary to use at least three positive lenses to correct various aberrations, especially spherical aberration, and to correct at least one chromatic aberration and Petzval sum, it is necessary to use at least one negative lens. It is desirable to do. In order to satisfactorily correct the spherical aberration generated in the fourth lens group,
In order to gently converge the light rays from the lens group, the fourth
It is necessary to use at least three positive lenses in the lens group, and it is not possible to obtain high optical performance with fewer lenses.
【００３２】さらに、収差補正上、第４レンズ群の最も
物体側のレンズは正レンズとすることが好ましい。負の
屈折力の第３レンズ群からの発散光束を第４レンズ群で
極力少ないレンズ枚数で効率的に収束させるには、第４
レンズ群の最も物体側に正レンズを配置させる必要があ
る。第４レンズ群の最も物体側のレンズを負レンズとす
ることは、第３レンズ群からの発散光束をさらに発散さ
せる作用となり、第４レンズ群での光線高が高くなるた
め、球面収差を悪化させることとなり、好ましくない。Further, in terms of aberration correction, it is preferable that the lens closest to the object in the fourth lens unit be a positive lens. In order to efficiently converge the divergent light flux from the third lens unit having negative refractive power with the fourth lens unit with the least number of lenses,
It is necessary to arrange the positive lens on the most object side of the lens group. Making the most object-side lens of the fourth lens group a negative lens has the effect of further diverging the divergent light flux from the third lens group, and increases the ray height in the fourth lens group, thus worsening spherical aberration. This is not preferable.
【００３３】[0033]
【実施例】以下、本発明のズームレンズを実施例１〜６
を用いてさらに詳細に説明する。なお、各実施例のレン
ズデータは後記する。図１は、本発明によるズームレン
ズの実施例１の広角端（ａ）、中間焦点距離（ｂ）、望
遠端（ｃ）におけるレンズ断面図である。図１中、Ｉ
は、ズーミングに際して固定で正の屈折力を持つ第１レ
ンズ群、ＩＩは、ズーミングに際して前後に移動して変
倍機能を有する負の屈折力を持つ第２レンズ群、ＩＩＩ
は、ズーミングに際して往復移動をして像面の位置補正
を行う負の屈折力を持つ第３レンズ群、ＩＶは、ズーミ
ングに際して固定で正の屈折力を持つ第４レンズ群であ
る。EXAMPLES Examples 1 to 6 of the zoom lens of the present invention will be described below.
Will be used to explain in more detail. The lens data of each example will be described later. FIG. 1 is a lens cross-sectional view at a wide-angle end (a), an intermediate focal length (b), and a telephoto end (c) of Example 1 of a zoom lens according to the present invention. In FIG. 1, I
Is a first lens group that has a fixed positive refractive power during zooming, and II is a second lens group that has a negative refractive power that moves back and forth during zooming and has a zoom function.
Is a third lens group having a negative refractive power that reciprocates during zooming to correct the position of the image plane, and IV is a fourth lens group that has a fixed positive refractive power during zooming.
【００３４】第１レンズ群Ｉは、物体側より順に、負レ
ンズ、正レンズ、正レンズ、正レンズからなり、軸上物
点に対する光束を狭める作用と軸上物点から出た光束を
第２レンズ群ＩＩに導く作用をする。第２レンズ群ＩＩ
は、物体側より順に、負レンズ、負レンズ、正レンズか
らなり、ズーミングに際して物体側から像側に移動する
ことにより変倍作用を有するレンズ群である。第３レン
ズ群ＩＩＩは、負レンズ１枚からなり、ズーミングに際
して往復移動することにより像面を一定の位置に保つ作
用を持つと共に、フォーカシングを行うレンズ群であ
る。第４レンズ群ＩＶは、物体側より順に、正レンズ、
正レンズ、正レンズ、負レンズ、正レンズからなり、ズ
ーミングに際して固定で第３レンズ群ＩＩＩからの発散
光束を結像する作用を持つ。また、絞りは、第３レンズ
群ＩＩＩと第４レンズ群ＩＶの間に配置されている。The first lens group I is composed of, in order from the object side, a negative lens, a positive lens, a positive lens, and a positive lens, and has a function of narrowing the light beam with respect to the axial object point and a second light beam emitted from the axial object point. It acts to lead to the lens group II. Second lens group II
Is a lens group including a negative lens, a negative lens, and a positive lens in order from the object side, and having a zooming effect by moving from the object side to the image side during zooming. The third lens group III is composed of one negative lens, has a function of keeping the image surface at a constant position by reciprocating during zooming, and is a lens group for focusing. The fourth lens group IV includes, in order from the object side, a positive lens,
It consists of a positive lens, a positive lens, a negative lens, and a positive lens, and has a function of fixing the divergent light flux from the third lens group III during zooming. Further, the diaphragm is arranged between the third lens group III and the fourth lens group IV.
【００３５】実施例１では、第４レンズ群ＩＶ中の負レ
ンズの像側の面を前記条件（２）を満足する非球面とし
たことにより、このレンズよりも物体側に配置した正レ
ンズで発生する負の球面収差を補正している。また、望
遠端における第２レンズ群ＩＩと第３レンズ群ＩＩＩの
間隔が前記条件（１）を満足することにより、高い光学
性能を維持したまま物点距離１ｍ程度までフォーカシン
グすることを可能としている。また、前記条件（３）を
満足することで、広角端から望遠端に至るまで高い光学
性能を維持することを可能としている。また、条件
（４）、条件（５）を満足することにより、第２レンズ
群ＩＩで発生する色収差を良好に補正している。In the first embodiment, the image-side surface of the negative lens in the fourth lens group IV is an aspherical surface that satisfies the above condition (2), so that it is a positive lens arranged closer to the object than the lens. The negative spherical aberration that occurs is corrected. Further, when the distance between the second lens group II and the third lens group III at the telephoto end satisfies the condition (1), it is possible to perform focusing up to an object distance of about 1 m while maintaining high optical performance. . By satisfying the condition (3), it is possible to maintain high optical performance from the wide-angle end to the telephoto end. By satisfying the conditions (4) and (5), the chromatic aberration generated in the second lens group II is corrected well.
【００３６】本実施例の無限遠物点に対する広角端
（ａ）、中間焦点距離（ｂ）、望遠端（ｃ）での収差状
況を表す球面収差、非点収差、歪曲収差、倍率色収差、
軸外横収差を示す収差図を図７に示し、物点距離１ｍに
対する同様の収差図を図８に示す。これらの収差図か
ら、本実施例のズームレンズが高い光学性能を達成して
いることが分かる。In the present embodiment, spherical aberration, astigmatism, distortion, chromatic aberration of magnification, which represent aberration conditions at the wide-angle end (a), the intermediate focal length (b), and the telephoto end (c) for an object point at infinity,
FIG. 7 shows an aberration diagram showing off-axis lateral aberration, and FIG. 8 shows a similar aberration diagram for an object point distance of 1 m. From these aberration diagrams, it can be seen that the zoom lens of this embodiment achieves high optical performance.
【００３７】図２は、本発明によるズームレンズの実施
例２の広角端におけるレンズ断面図である。実施例２
は、第４レンズ群ＩＶ以外は実施例１と同様の構成であ
り、実施例１と比較して、第４レンズ群ＩＶにさらに非
球面を１面加えたことでレンズ枚数の削減を可能とした
例である。実施例１では、球面収差の補正上、非球面を
用いた負レンズよりも物体側に３枚の正レンズを必要と
したが、その中の１枚に非球面を採用することにより２
枚の正レンズで構成することを可能とした。実施例２で
は、第４レンズ群ＩＶ中最も物体側の正レンズの物体側
の面に非球面を適用しているが、この正レンズの像側の
面を非球面としても、同様の効果を得られることは言う
までもない。また、第４レンズ群ＩＶの最も物体側より
２枚目の正レンズに前記条件（２）を満足する非球面を
採用しても、実施例２と同様の補正効果を得ることがで
きる。FIG. 2 is a lens sectional view at a wide-angle end of a second embodiment of the zoom lens according to the present invention. Example 2
The configuration is the same as that of the example 1 except for the fourth lens group IV. Compared with the example 1, it is possible to reduce the number of lenses by adding one aspherical surface to the fourth lens group IV. It is an example. In Example 1, three positive lenses were required on the object side of the negative lens using an aspherical surface in order to correct spherical aberration, but by using an aspherical surface for one of them,
It is possible to configure with a positive lens. In the second embodiment, the aspherical surface is applied to the object-side surface of the positive lens closest to the object in the fourth lens group IV. However, even if the image-side surface of this positive lens is an aspherical surface, the same effect can be obtained. It goes without saying that you can get it. Further, even if an aspherical surface satisfying the condition (2) is adopted as the second positive lens element of the fourth lens group IV farthest from the object side, the same correction effect as that of the second embodiment can be obtained.
【００３８】また、実施例２では、実施例１と比較し
て、第４レンズ群ＩＶで正レンズを１枚減らしたため、
正レンズで発生する色収差が大きくなっているが、接合
レンズを第４レンズ群ＩＶ中に用いることで、これを良
好に補正している。Further, in Example 2, as compared with Example 1, one positive lens is reduced in the fourth lens group IV,
Although the chromatic aberration generated by the positive lens is large, this is favorably corrected by using the cemented lens in the fourth lens group IV.
【００３９】本実施例の図７、８と同様の収差図をそれ
ぞれ図９、１０に示す。これらの収差図から、本実施例
が高い光学性能を達成していることが分かる。Aberration diagrams similar to those of FIGS. 7 and 8 of this embodiment are shown in FIGS. From these aberration diagrams, it can be seen that this example achieves high optical performance.
【００４０】図３は、本発明によるズームレンズの実施
例３の広角端におけるレンズ断面図である。実施例３
は、第３レンズ群ＩＩＩ以外は実施例２と同様の構成で
あるが、第３レンズ群ＩＩＩを、物体側より順に、負レ
ンズ、正レンズの２枚構成としたことで、フォーカシン
グにおける収差変動を少なくし、物点距離無限遠から至
近物点距離までの光学性能の向上を達成している。本実
施例の図７、８と同様の収差図をそれぞれ図１１、１２
に示す。これらの収差図から、本実施例が高い光学性能
を達成していることが分かる。FIG. 3 is a lens sectional view at a wide-angle end of a third embodiment of the zoom lens according to the present invention. Example 3
Has the same configuration as that of the second embodiment except for the third lens group III, but the third lens group III has a two-lens configuration including a negative lens and a positive lens in order from the object side. The optical performance has been improved from infinity to the closest object point distance. Aberration diagrams similar to those of FIGS. 7 and 8 of the present embodiment are shown in FIGS.
Shown in. From these aberration diagrams, it can be seen that this example achieves high optical performance.
【００４１】図４は、本発明によるズームレンズの実施
例４の広角端におけるレンズ断面図である。実施例４
は、第４レンズ群ＩＶ以外は実施例３と同様の構成であ
るが、第４レンズ群ＩＶを、物体側より順に、両凸正レ
ンズと曲率の強い面を物体側に向けた負レンズの接合レ
ンズと、正レンズ、両凸正レンズと両凹負レンズの接合
レンズ、正レンズの構成で、両凹負レンズの像側の面を
非球面としている。本実施例では、第４レンズ群ＩＶの
最も物体側のレンズを接合レンズとしたことで、軸上色
収差の補正が有利となっている。本実施例の図７、８と
同様の収差図をそれぞれ図１３、１４に示す。FIG. 4 is a lens sectional view at the wide-angle end of a fourth embodiment of the zoom lens according to the present invention. Example 4
Has the same configuration as that of the third embodiment except for the fourth lens group IV, except that the fourth lens group IV includes, in order from the object side, a biconvex positive lens and a negative lens having a strongly curved surface facing the object side. The cemented lens and the positive lens, the cemented lens of the biconvex positive lens and the biconcave negative lens, and the positive lens are configured so that the image-side surface of the biconcave negative lens is an aspherical surface. In this embodiment, the most object side lens of the fourth lens group IV is a cemented lens, which is advantageous in correcting axial chromatic aberration. Aberration diagrams similar to FIGS. 7 and 8 of this example are shown in FIGS. 13 and 14, respectively.
【００４２】図５は、本発明によるズームレンズの実施
例５の広角端におけるレンズ断面図である。実施例５
は、第４レンズ群ＩＶ以外は実施例３と同様の構成であ
るが、第４レンズ群ＩＶを、物体側より順に、両凸正レ
ンズと曲率の強い面を物体側に向けた負レンズの接合レ
ンズと、両凸正レンズと両凹負レンズの接合レンズ、正
レンズの構成で、最も物体側の正レンズの物体側の面と
両凹負レンズの像側の面を非球面としている。本実施例
では、第４レンズ群ＩＶの最も物体側のレンズを接合レ
ンズとしたことで、軸上色収差の補正が有利となってい
る。本実施例の図７、８と同様の収差図をそれぞれ図１
５、１６に示す。FIG. 5 is a lens sectional view at the wide-angle end of a fifth embodiment of the zoom lens according to the present invention. Example 5
Has the same configuration as that of the third embodiment except for the fourth lens group IV, except that the fourth lens group IV includes, in order from the object side, a biconvex positive lens and a negative lens having a strongly curved surface facing the object side. With a cemented lens, a cemented lens of a biconvex positive lens and a biconcave negative lens, and a positive lens, the object side surface of the positive lens closest to the object side and the image side surface of the biconcave negative lens are aspherical. In this embodiment, the most object side lens of the fourth lens group IV is a cemented lens, which is advantageous in correcting axial chromatic aberration. Aberration diagrams similar to FIGS. 7 and 8 of this embodiment are shown in FIG.
5 and 16 are shown.
【００４３】図６は、本発明によるズームレンズの実施
例６の広角端におけるレンズ断面図である。実施例６
は、第４レンズ群ＩＶ以外は実施例３と同様の構成であ
るが、第４レンズ群ＩＶを、物体側より順に、正レン
ズ、両凸正レンズと両凹負レンズの接合レンズ、正レン
ズ、正レンズの構成で、両凹レンズの像側の面を非球面
としている。本実施例では、実施例３と比較して、第４
レンズ群ＩＶの最も像面側に正レンズをさらに１枚配置
したことにより、倍率色収差の補正が有利となってい
る。本実施例の図７、８と同様の収差図をそれぞれ図１
７、１８に示す。FIG. 6 is a lens sectional view at the wide-angle end of a sixth embodiment of the zoom lens according to the present invention. Example 6
Has the same configuration as in Example 3 except for the fourth lens group IV, but the fourth lens group IV includes, in order from the object side, a positive lens, a cemented lens of a biconvex positive lens and a biconcave negative lens, and a positive lens. In the positive lens configuration, the image-side surface of the biconcave lens is an aspherical surface. In the present embodiment, compared with the third embodiment, the fourth
By disposing one more positive lens on the most image side of the lens group IV, correction of lateral chromatic aberration is advantageous. Aberration diagrams similar to FIGS. 7 and 8 of this embodiment are shown in FIG.
7 and 18.
【００４４】次に、上記実施例１〜６のレンズデータを
示すが、以下において、記号は、上記の外、ｆは全系の
焦点距離、ＦNOはＦナンバー、２ωは画角、ｒ1 、ｒ2
…は各レンズ面の曲率半径、ｄ1 、ｄ2 …は各レンズ面
間の間隔、ｎd1、ｎd2…は各レンズのｄ線の屈折率、ν
d1、νd2…は各レンズのアッベ数である。また、非球面
形状は、前記式（ａ）にて表される。Next, the lens data of Examples 1 to 6 will be shown. In the following, the symbols are the above, f is the focal length of the entire system, F NO is the F number, 2ω is the angle of view, r 1 , R 2
... is the radius of curvature of each lens surface, d 1 , d 2 ... is the distance between the lens surfaces, n d1 , n d2 ... is the refractive index of the d-line of each lens, ν
d1 , ν d2 ... Are the Abbe numbers of each lens. Further, the aspherical shape is represented by the formula (a).
【００４５】実施例１ ｆ ＝ 9.30 〜 24.96 〜 70.17 ＦNO＝ 2.0 〜 2.0 〜 2.0 ２ω＝ 47.64 〜 18.00 〜 6.44 ° ｒ1 = 121.9795 ｄ1 = 2.2000 ｎd1 =1.78472 νd1 =25.68 ｒ2 = 56.7333 ｄ2 = 6.3000 ｎd2 =1.69680 νd2 =56.49 ｒ3 = 716.1330 ｄ3 = 0.1000 ｒ4 = 55.5421 ｄ4 = 4.8000 ｎd3 =1.49700 νd3 =81.61 ｒ5 = 196.0489 ｄ5 = 0.1000 ｒ6 = 56.1280 ｄ6 = 4.2000 ｎd4 =1.49700 νd4 =81.61 ｒ7 = 117.2739 ｄ7 =(可変) ｒ8 = 190.5609 ｄ8 = 1.2000 ｎd5 =1.72916 νd5 =54.68 ｒ9 = 11.8915 ｄ9 = 4.9000 ｒ10= -39.2638 ｄ10= 1.2000 ｎd6 =1.61700 νd6 =62.79 ｒ11= 38.5980 ｄ11= 0.1000 ｒ12= 20.5048 ｄ12= 2.0000 ｎd7 =1.75550 νd7 =25.07 ｒ13= 82.2265 ｄ13=(可変) ｒ14= -28.1739 ｄ14= 1.8006 ｎd8 =1.49700 νd8 =81.61 ｒ15= -468.0374 ｄ15=(可変) ｒ16= ∞（絞り） ｄ16= 0.8000 ｒ17= 27.1232 ｄ17= 3.0019 ｎd9 =1.61800 νd9 =63.38 ｒ18= 261.4421 ｄ18= 0.1000 ｒ19= 19.6301 ｄ19= 2.5642 ｎd10=1.61800 νd10=63.38 ｒ20= 62.5394 ｄ20= 2.7004 ｒ21= 15.2579 ｄ21= 6.0765 ｎd11=1.61800 νd11=63.38 ｒ22= -43.4380 ｄ22= 0.4934 ｒ23= -32.7706 ｄ23= 2.5750 ｎd12=1.76180 νd12=27.11 ｒ24= 13.5869（非球面） ｄ24= 8.5688 ｒ25= 20.8680 ｄ25= 1.8000 ｎd13=1.74100 νd13=52.68 ｒ26= -203.0510 非球面係数 第２４面 Ａ2= 0 Ａ4= 0.13649×10-3 Ａ6= 0.48774×10-6 Ａ8= 0.11236×10-8 Ｄ2T／ｆT ＝0.141 （第２４面） Ａ4 ＝ 0.13649×10-3 （ｎa −ｎa ' ＝0.76180 ）
。Example 1 f = 9.30 to 24.96 to 70.17 F NO = 2.0 to 2.0 to 2.0 2ω = 47.64 to 18.00 to 6.44 ° r 1 = 121.9795 d 1 = 2.2000 n d1 = 1.78472 ν d1 = 25.68 r 2 = 56.7333 d 2 = 6.3000 n d2 = 1.69680 ν d2 = 56.49 r 3 = 716.1330 d 3 = 0.1000 r 4 = 55.5421 d 4 = 4.8000 n d3 = 1.49700 ν d3 = 81.61 r 5 = 196.0489 d 5 = 0.1000 r 6 = 56.1280 d 6 = 4.2000 n d4 = 1.49700 ν d4 = 81.61 r 7 = 117.2739 d 7 = (variable) r 8 = 190.5609 d 8 = 1.2000 n d5 = 1.72916 ν d5 = 54.68 r 9 = 11.8915 d 9 = 4.9000 r 10 = -39.2638 d 10 = 1.2000 n d6 = 1.61700 ν d6 = 62.79 r 11 = 38.5980 d 11 = 0.1000 r 12 = 20.5048 d 12 = 2.0000 n d7 = 1.75550 ν d7 = 25.07 r 13 = 82.2265 d 13 = (variable) r 14 = -28.1739 d 14 = 1.8006 n d8 = 1.49700 ν d8 = 81.61 r 15 = -468.0374 d 15 = (variable) r 16 = ∞ (aperture) d 16 = 0.8000 r 17 = 27.1232 d 17 = 3.0019 n d9 = 1.61800 ν d9 = 63.38 r 18 = 261.4421 d 18 = 0.1000 r 19 = 1 9.6301 d 19 = 2.5642 n d10 = 1.61800 ν d10 = 63.38 r 20 = 62.5394 d 20 = 2.7004 r 21 = 15.2579 d 21 = 6.0765 n d11 = 1.61800 ν d11 = 63.38 r 22 = -43.4380 d 22 = 0.4934 r 23 =- 32.7706 d 23 = 2.5750 n d12 = 1.76180 ν d12 = 27.11 r 24 = 13.5869 (aspherical surface) d 24 = 8.5688 r 25 = 20.8680 d 25 = 1.8000 n d13 = 1.74100 ν d13 = 52.68 r 26 = -203.0510 Aspheric coefficient 24th surface A 2 = 0 A 4 = 0.13649 × 10 -3 A 6 = 0.48774 × 10 -6 A 8 = 0.11236 × 10 -8 D 2T / f T = 0.141 (24th surface) A 4 = 0.13649 × 10 -3 (n a -n a '= 0.76180)
.
【００４６】実施例２ ｆ ＝ 9.16 〜 23.93 〜 71.07 ＦNO＝ 2.0 〜 2.0 〜 2.0 ２ω＝ 47.64 〜 18.66 〜 6.32 ° ｒ1 = 175.0509 ｄ1 = 2.1000 ｎd1 =1.80518 νd1 =25.43 ｒ2 = 70.0850 ｄ2 = 5.8000 ｎd2 =1.65160 νd2 =58.52 ｒ3 = 4286.6204 ｄ3 = 0.1000 ｒ4 = 104.2578 ｄ4 = 4.1200 ｎd3 =1.49700 νd3 =81.61 ｒ5 = -2211.8323 ｄ5 = 0.1000 ｒ6 = 39.9259 ｄ6 = 5.0000 ｎd4 =1.49700 νd4 =81.61 ｒ7 = 99.5536 ｄ7 =(可変) ｒ8 = 90.9578 ｄ8 = 1.2000 ｎd5 =1.72916 νd5 =54.68 ｒ9 = 11.7160 ｄ9 = 4.9000 ｒ10= -33.4188 ｄ10= 1.2000 ｎd6 =1.61700 νd6 =62.79 ｒ11= 43.4493 ｄ11= 0.1000 ｒ12= 21.8253 ｄ12= 2.5000 ｎd7 =1.76180 νd7 =27.11 ｒ13= -1369.0346 ｄ13=(可変) ｒ14= -36.4548 ｄ14= 1.8018 ｎd8 =1.61700 νd8 =62.79 ｒ15= -1131.7725 ｄ15=(可変) ｒ16= ∞（絞り） ｄ16= 0.8000 ｒ17= 17.8611（非球面） ｄ17= 3.4921 ｎd9 =1.61800 νd9 =63.38 ｒ18= -56.3922 ｄ18= 1.8308 ｒ19= 17.7910 ｄ19= 4.8667 ｎd10=1.61800 νd10=63.38 ｒ20= -583.7263 ｄ20= 1.7622 ｎd11=1.78472 νd11=25.71 ｒ21= 12.1926（非球面） ｄ21= 5.2612 ｒ22= 325.5386 ｄ22= 1.8000 ｎd12=1.78590 νd12=44.18 ｒ23= -23.9952 非球面係数 第１７面 Ａ2= 0 Ａ4=-0.31818×10-4 Ａ6=-0.10282×10-6 Ａ8= 0.31468×10-11 第２１面 Ａ2= 0 Ａ4= 0.45203×10-4 Ａ6=-0.22022×10-6 Ａ8=-0.29334×10-8 Ｄ2T／ｆT ＝0.184 （第１７面） Ａ4 ＝-0.31818×10-4 （ｎa −ｎa ' ＝-0.618 ） （第２１面） Ａ4 ＝ 0.45203×10-4 （ｎa −ｎa ' ＝0.78472 ）
。Example 2 f = 9.16 ~ 23.93 ~ 71.07 F NO = 2.0 ~ 2.0 ~ 2.0 2ω = 47.64 ~ 18.66 ~ 6.32 ° r 1 = 175.0509 d 1 = 2.1000 n d1 = 1.80518 ν d1 = 25.43 r 2 = 70.0850 d 2 = 5.8000 n d2 = 1.65160 ν d2 = 58.52 r 3 = 4286.6204 d 3 = 0.1000 r 4 = 104.2578 d 4 = 4.1200 n d3 = 1.49700 ν d3 = 81.61 r 5 = -2211.8323 d 5 = 0.1000 r 6 = 39.9259 d 6 = 5.0000 n d4 = 1.49700 ν d4 = 81.61 r 7 = 99.5536 d 7 = (variable) r 8 = 90.9578 d 8 = 1.2000 n d5 = 1.72916 ν d5 = 54.68 r 9 = 11.7160 d 9 = 4.9000 r 10 = -33.4188 d 10 = 1.2000 n d6 = 1.61700 ν d6 = 62.79 r 11 = 43.4493 d 11 = 0.1000 r 12 = 21.8253 d 12 = 2.5000 n d7 = 1.76180 ν d7 = 27.11 r 13 = -1369.0346 d 13 = (variable) r 14 =- 36.4548 d 14 = 1.8018 n d8 = 1.61700 ν d8 = 62.79 r 15 = -1131.7725 d 15 = (variable) r 16 = ∞ (aperture) d 16 = 0.8000 r 17 = 17.8611 (aspherical surface) d 17 = 3.4921 n d9 = 1.61800 ν d9 = 63.38 r 18 = -56.3922 d 1 8 = 1.8308 r 19 = 17.7910 d 19 = 4.8667 n d10 = 1.61800 ν d10 = 63.38 r 20 = -583.7263 d 20 = 1.7622 n d11 = 1.78472 ν d11 = 25.71 r 21 = 12.1926 (aspherical surface) d 21 = 5.2612 r 22 = 325.5386 d 22 = 1.8000 n d12 = 1.78590 ν d12 = 44.18 r 23 = -23.9952 Aspherical coefficients seventeenth surface A 2 = 0 A 4 = -0.31818 × 10 -4 A 6 = -0.10282 × 10 -6 A 8 = 0.31468 × 10 -11 21st surface A 2 = 0 A 4 = 0.45203 × 10 - 4 A 6 = -0.22022 × 10 -6 A 8 = -0.29334 × 10 -8 D 2T / f T = 0.184 ( surface No. 17) A 4 = -0.31818 × 10 -4 (n a -n a '= -0.618 ) (21 surface) A 4 = 0.45203 × 10 -4 (n a -n a '= 0.78472)
.
【００４７】実施例３ ｆ ＝ 9.03 〜 23.75 〜 71.38 ＦNO＝ 2.0 〜 2.0 〜 2.0 ２ω＝ 48.96 〜 18.82 〜 6.32 ° ｒ1 = 160.8472 ｄ1 = 2.1438 ｎd1 =1.80518 νd1 =25.43 ｒ2 = 66.8362 ｄ2 = 5.8124 ｎd2 =1.65830 νd2 =57.33 ｒ3 = 1600.1190 ｄ3 = 0.1000 ｒ4 = 103.3389 ｄ4 = 4.1587 ｎd3 =1.49700 νd3 =81.61 ｒ5 = 6148.9227 ｄ5 = 0.1000 ｒ6 = 41.7187 ｄ6 = 4.7878 ｎd4 =1.49700 νd4 =81.61 ｒ7 = 120.3528 ｄ7 =(可変) ｒ8 = 178.4985 ｄ8 = 1.2000 ｎd5 =1.72916 νd5 =54.68 ｒ9 = 11.6514 ｄ9 = 4.7283 ｒ10= -35.1952 ｄ10= 1.2000 ｎd6 =1.61700 νd6 =62.79 ｒ11= 41.8775 ｄ11= 0.1000 ｒ12= 21.2293 ｄ12= 1.8500 ｎd7 =1.76182 νd7 =26.52 ｒ13= 120.9734 ｄ13=(可変) ｒ14= -33.2033 ｄ14= 1.2000 ｎd8 =1.49700 νd8 =81.61 ｒ15= 25.3812 ｄ15= 0.2000 ｒ16= 26.3892 ｄ16= 1.4000 ｎd9 =1.61700 νd9 =62.79 ｒ17= 118.1373 ｄ17=(可変) ｒ18= ∞（絞り） ｄ18= 0.8000 ｒ19= 18.0348（非球面） ｄ19= 4.5877 ｎd10=1.61800 νd10=63.38 ｒ20= -48.9595 ｄ20= 3.7938 ｒ21= 16.3958 ｄ21= 4.4612 ｎd11=1.61700 νd11=62.79 ｒ22= -134.7371 ｄ22= 1.1016 ｎd12=1.76182 νd12=26.55 ｒ23= 13.5412（非球面） ｄ23= 7.0063 ｒ24= 128.2404 ｄ24= 2.0000 ｎd13=1.65830 νd13=57.33 ｒ25= -26.4317 非球面係数 第１９面 Ａ2= 0 Ａ4=-0.26151×10-4 Ａ6=-0.79007×10-7 Ａ8= 0 第２３面 Ａ2= 0 Ａ4= 0.71228×10-4 Ａ6= 0.12224×10-6 Ａ8= 0 Ｄ2T／ｆT ＝0.134 （第１９面） Ａ4 ＝-0.26151×10-4 （ｎa −ｎa ' ＝-0.618 ） （第２３面） Ａ4 ＝ 0.71228×10-4 （ｎa −ｎa ' ＝0.76182 ）
。Example 3 f = 9.03 ~ 23.75 ~ 71.38 F NO = 2.0 ~ 2.0 ~ 2.0 2ω = 48.96 ~ 18.82 ~ 6.32 ° r 1 = 160.8472 d 1 = 2.1438 n d1 = 1.80518 ν d1 = 25.43 r 2 = 66.8362 d 2 = 5.8124 n d2 = 1.65830 ν d2 = 57.33 r 3 = 1600.1190 d 3 = 0.1000 r 4 = 103.3389 d 4 = 4.1587 n d3 = 1.49700 ν d3 = 81.61 r 5 = 6148.9227 d 5 = 0.1000 r 6 = 41.7187 d 6 = 4.7878 n d4 = 1.49700 ν d4 = 81.61 r 7 = 120.3528 d 7 = ( variable) r 8 = 178.4985 d 8 = 1.2000 n d5 = 1.72916 ν d5 = 54.68 r 9 = 11.6514 d 9 = 4.7283 r 10 = -35.1952 d 10 = 1.2000 n d6 = 1.61700 ν d6 = 62.79 r 11 = 41.8775 d 11 = 0.1000 r 12 = 21.2293 d 12 = 1.8500 n d7 = 1.76182 ν d7 = 26.52 r 13 = 120.9734 d 13 = (variable) r 14 = -33.2033 d 14 = 1.2000 n d8 = 1.49700 ν d8 = 81.61 r 15 = 25.3812 d 15 = 0.2000 r 16 = 26.3892 d 16 = 1.4000 n d9 = 1.61700 ν d9 = 62.79 r 17 = 118.1373 d 17 = (variable) r 18 = ∞ ( Aperture) d 18 = 0.8000 r 19 = 18.0348 (aspherical surface) d 19 = 4.5877 n d10 = 1.61800 ν d10 = 63.38 r 20 = -48.9595 d 20 = 3.7938 r 21 = 16.3958 d 21 = 4.4612 n d11 = 1.61700 ν d11 = 62.79 r 22 = -134.7371 d 22 = 1.1016 n d12 = 1.76182 ν d12 = 26.55 r 23 = 13.5412 (aspherical surface) d 23 = 7.0063 r 24 = 128.2404 d 24 = 2.0000 n d13 = 1.65830 ν d13 = 57.33 r 25 = -26.4317 Aspherical surface 19th surface A 2 = 0 A 4 = -0.26151 × 10 -4 A 6 = -0.79007 × 10 -7 A 8 = 0 23rd surface A 2 = 0 A 4 = 0.71228 × 10 -4 A 6 = 0.12224 × 10 -6 A 8 = 0 D 2T / f T = 0.134 ( nineteenth surface) A 4 = -0.26151 × 10 -4 (n a -n a '= -0.618) ( surface No. 23) A 4 = 0.71228 × 10 -4 (n a -n a '= 0.76182)
.
【００４８】実施例４ ｆ ＝ 9.01 〜 24.72 〜 69.70 ＦNO＝ 2.0 〜 2.0 〜 2.0 ２ω＝ 48.90 〜 18.12 〜 6.46 ° ｒ1 = 119.0982 ｄ1 = 2.2000 ｎd1 =1.78472 νd1 =25.68 ｒ2 = 54.8411 ｄ2 = 6.2000 ｎd2 =1.69680 νd2 =56.49 ｒ3 = 829.8782 ｄ3 = 0.1000 ｒ4 = 52.7340 ｄ4 = 4.5000 ｎd3 =1.49700 νd3 =81.61 ｒ5 = 187.6922 ｄ5 = 0.1000 ｒ6 = 59.0678 ｄ6 = 4.5302 ｎd4 =1.49700 νd4 =81.61 ｒ7 = 100.8047 ｄ7 =(可変) ｒ8 = 171.7139 ｄ8 = 1.2000 ｎd5 =1.72916 νd5 =54.68 ｒ9 = 11.7870 ｄ9 = 4.9000 ｒ10= -34.8177 ｄ10= 1.2000 ｎd6 =1.61700 νd6 =62.79 ｒ11= 38.5941 ｄ11= 0.1000 ｒ12= 21.4261 ｄ12= 2.0000 ｎd7 =1.75550 νd7 =25.07 ｒ13= 145.2350 ｄ13=(可変) ｒ14= -32.8457 ｄ14= 1.2000 ｎd8 =1.49700 νd8 =81.61 ｒ15= 21.7740 ｄ15= 0.2000 ｒ16= 22.9664 ｄ16= 1.5000 ｎd9 =1.61700 νd9 =62.79 ｒ17= 127.2305 ｄ17=(可変) ｒ18= ∞（絞り） ｄ18= 0.8000 ｒ19= 33.2749 ｄ19= 2.7000 ｎd10=1.61800 νd10=63.38 ｒ20= -47.9619 ｄ20= 0.9000 ｎd11=1.63636 νd11=35.37 ｒ21= -96.0329 ｄ21= 0.1000 ｒ22= 20.7216 ｄ22= 3.5546 ｎd12=1.61800 νd12=63.38 ｒ23= 48.1162 ｄ23= 3.7855 ｒ24= 15.5898 ｄ24= 6.4199 ｎd13=1.61700 νd13=62.79 ｒ25= -35.8909 ｄ25= 2.5308 ｎd14=1.76182 νd14=26.55 ｒ26= 14.6133（非球面） ｄ26= 8.6502 ｒ27= 29.2427 ｄ27= 1.7000 ｎd15=1.77250 νd15=49.66 ｒ28= -110.2733 非球面係数 第２６面 Ａ2= 0 Ａ4= 0.11337×10-3 Ａ6= 0.44943×10-6 Ａ8= 0.27126×10-8 Ｄ2T／ｆT ＝0.142 （第２６面） Ａ4 ＝ 0.11337×10-3 （ｎa −ｎa ' ＝0.76182 ）
。Example 4 f = 9.01 to 24.72 to 69.70 F NO = 2.0 to 2.0 to 2.0 2ω = 48.90 to 18.12 to 6.46 ° r 1 = 119.0982 d 1 = 2.2000 n d1 = 1.78472 ν d1 = 25.68 r 2 = 54.8411 d 2 = 6.2000 n d2 = 1.69680 ν d2 = 56.49 r 3 = 829.8782 d 3 = 0.1000 r 4 = 52.7340 d 4 = 4.5000 n d3 = 1.49700 ν d3 = 81.61 r 5 = 187.6922 d 5 = 0.1000 r 6 = 59.0678 d 6 = 4.5302 n d4 = 1.49700 ν d4 = 81.61 r 7 = 100.8047 d 7 = (variable) r 8 = 171.7139 d 8 = 1.2000 n d5 = 1.72916 ν d5 = 54.68 r 9 = 11.7870 d 9 = 4.9000 r 10 = -34.8177 d 10 = 1.2000 n d6 = 1.61700 ν d6 = 62.79 r 11 = 38.5941 d 11 = 0.1000 r 12 = 21.4261 d 12 = 2.0000 n d7 = 1.75550 ν d7 = 25.07 r 13 = 145.2350 d 13 = (variable) r 14 = -32.8457 d 14 = 1.2000 n d8 = 1.49700 ν d8 = 81.61 r 15 = 21.7740 d 15 = 0.2000 r 16 = 22.9664 d 16 = 1.5000 n d9 = 1.61700 ν d9 = 62.79 r 17 = 127.2305 d 17 = (variable) r 18 = ∞ ( Aperture) d 18 = 0.8000 r 19 = 33 .2749 d 19 = 2.7000 n d10 = 1.61800 ν d10 = 63.38 r 20 = -47.9619 d 20 = 0.9000 n d11 = 1.63636 ν d11 = 35.37 r 21 = -96.0329 d 21 = 0.1000 r 22 = 20.7216 d 22 = 3.5546 n d12 = 1.61800 ν d12 = 63.38 r 23 = 48.1162 d 23 = 3.7855 r 24 = 15.5898 d 24 = 6.4199 n d13 = 1.61700 ν d13 = 62.79 r 25 = -35.8909 d 25 = 2.5308 n d14 = 1.76182 ν d14 = 26.55 r 26 = 14.6133 (aspherical surface) d 26 = 8.6502 r 27 = 29.2427 d 27 = 1.7000 n d15 = 1.77250 ν d15 = 49.66 r 28 = -110.2733 Aspheric coefficient 26th surface A 2 = 0 A 4 = 0.11337 × 10 -3 A 6 = 0.44943 × 10 -6 A 8 = 0.27126 × 10 -8 D 2T / f T = 0.142 (26th surface) A 4 = 0.11337 × 10 -3 (n a -n a '= 0.76182)
.
【００４９】実施例５ ｆ ＝ 9.18 〜 26.72 〜 69.72 ＦNO＝ 2.0 〜 2.0 〜 2.0 ２ω＝ 47.36 〜 16.70 〜 6.46 ° ｒ1 = 110.5560 ｄ1 = 2.1000 ｎd1 =1.80518 νd1 =25.43 ｒ2 = 58.9609 ｄ2 = 5.8200 ｎd2 =1.61800 νd2 =63.38 ｒ3 = 688.7626 ｄ3 = 0.1000 ｒ4 = 122.4373 ｄ4 = 4.1000 ｎd3 =1.49700 νd3 =81.61 ｒ5 = 1012.3345 ｄ5 = 0.1000 ｒ6 = 42.6374 ｄ6 = 4.7200 ｎd4 =1.49700 νd4 =81.61 ｒ7 = 122.5691 ｄ7 =(可変) ｒ8 = 72.7839 ｄ8 = 1.2000 ｎd5 =1.72600 νd5 =53.56 ｒ9 = 10.8327 ｄ9 = 4.7000 ｒ10= -29.3556 ｄ10= 1.2000 ｎd6 =1.65160 νd6 =58.52 ｒ11= 40.5988 ｄ11= 0.1000 ｒ12= 21.2596 ｄ12= 1.8500 ｎd7 =1.76182 νd7 =26.52 ｒ13= -4147.6798 ｄ13=(可変) ｒ14= -35.0607 ｄ14= 1.2000 ｎd8 =1.61700 νd8 =62.79 ｒ15= 29.7309 ｄ15= 0.2000 ｒ16= 29.8509 ｄ16= 1.4000 ｎd9 =1.61700 νd9 =62.79 ｒ17= -823.7581 ｄ17=(可変) ｒ18= ∞（絞り） ｄ18= 1.0000 ｒ19= 17.6906（非球面） ｄ19= 3.6379 ｎd10=1.65830 νd10=57.33 ｒ20= -30.3800 ｄ20= 1.0000 ｎd11=1.68893 νd11=31.08 ｒ21= -59.1520 ｄ21= 3.3310 ｒ22= 19.4134 ｄ22= 4.6048 ｎd12=1.61700 νd12=62.79 ｒ23= -126.7583 ｄ23= 1.3515 ｎd13=1.75520 νd13=27.51 ｒ24= 15.0005（非球面） ｄ24= 5.2635 ｒ25= -356.8506 ｄ25= 1.9000 ｎd14=1.65830 νd14=53.44 ｒ26= -21.2759 非球面係数 第１９面 Ａ2= 0 Ａ4=-0.25377×10-4 Ａ6=-0.80335×10-7 Ａ8=-0.83058×10-10 第２４面Ａ2= 0 Ａ4= 0.85075×10-4 Ａ6= 0.15914×10-6 Ａ8=-0.81696×10-9 Ｄ2T／ｆT ＝0.126 （第１９面） Ａ4 ＝-0.25377×10-4 （ｎa −ｎa ' ＝-0.6583 ） （第２４面） Ａ4 ＝ 0.85075×10-4 （ｎa −ｎa ' ＝0.7552 ）
。Example 5 f = 9.18 ~ 26.72 ~ 69.72 F NO = 2.0 ~ 2.0 ~ 2.0 2ω = 47.36 ~ 16.70 ~ 6.46 ° r 1 = 110.5560 d 1 = 2.1000 n d1 = 1.80518 ν d1 = 25.43 r 2 = 58.9609 d 2 = 5.8200 n d2 = 1.61800 ν d2 = 63.38 r 3 = 688.7626 d 3 = 0.1000 r 4 = 122.4373 d 4 = 4.1000 n d3 = 1.49700 ν d3 = 81.61 r 5 = 1012.3345 d 5 = 0.1000 r 6 = 42.6374 d 6 = 4.7200 n d4 = 1.49700 ν d4 = 81.61 r 7 = 122.5691 d 7 = (variable) r 8 = 72.7839 d 8 = 1.2000 n d5 = 1.72600 ν d5 = 53.56 r 9 = 10.8327 d 9 = 4.7000 r 10 = -29.3556 d 10 = 1.2000 n d6 = 1.65160 ν d6 = 58.52 r 11 = 40.5988 d 11 = 0.1000 r 12 = 21.2596 d 12 = 1.8500 n d7 = 1.76182 ν d7 = 26.52 r 13 = -4147.6798 d 13 = (variable) r 14 = -35.0607 d 14 = 1.2000 n d8 = 1.61700 ν d8 = 62.79 r 15 = 29.7309 d 15 = 0.2000 r 16 = 29.8509 d 16 = 1.4000 n d9 = 1.61700 ν d9 = 62.79 r 17 = -823.7581 d 17 = (variable) r 18 = ∞ (Aperture) d 18 = 1.0000 r 19 = 17.6906 (aspherical surface) d 19 = 3.6379 n d10 = 1.65830 ν d10 = 57.33 r 20 = -30.3800 d 20 = 1.0000 n d11 = 1.68893 ν d11 = 31.08 r 21 = -59.1520 d 21 = 3.3310 r 22 = 19.4134 d 22 = 4.6048 n d12 = 1.61700 ν d12 = 62.79 r 23 = -126.7583 d 23 = 1.3515 n d13 = 1.75520 ν d13 = 27.51 r 24 = 15.0005 (aspherical surface) d 24 = 5.2635 r 25 = -356.8506 d 25 = 1.9000 n d14 = 1.65830 ν d14 = 53.44 r 26 = -21.2759 Aspheric coefficient 19th surface A 2 = 0 A 4 = -0.25377 × 10 -4 A 6 = -0.80335 × 10 -7 A 8 = -0.83058 × 10 -10 24th surface A 2 = 0 A 4 = 0.85075 × 10 -4 A 6 = 0.15914 × 10 -6 A 8 = -0.81696 × 10 -9 D 2T / f T = 0.126 ( nineteenth surface) A 4 = -0.25377 × 10 -4 (n a -n a '= -0.6583 ) (24 surface) A 4 = 0.85075 × 10 -4 (n a -n a '= 0.7552)
.
【００５０】実施例６ ｆ ＝ 9.18 〜 24.00 〜 70.80 ＦNO＝ 2.0 〜 2.0 〜 2.0 ２ω＝ 48.24 〜 18.64 〜 6.36 ° ｒ1 = 169.2518 ｄ1 = 2.2000 ｎd1 =1.78472 νd1 =25.68 ｒ2 = 64.9998 ｄ2 = 6.0000 ｎd2 =1.69680 νd2 =56.49 ｒ3 = -6150.3260 ｄ3 = 0.1000 ｒ4 = 106.3196 ｄ4 = 4.2459 ｎd3 =1.49700 νd3 =81.61 ｒ5 = 511.7991 ｄ5 = 0.1000 ｒ6 = 41.1752 ｄ6 = 4.8000 ｎd4 =1.49700 νd4 =81.61 ｒ7 = 122.5050 ｄ7 =(可変) ｒ8 = 187.3533 ｄ8 = 1.2000 ｎd5 =1.72916 νd5 =54.68 ｒ9 = 11.5386 ｄ9 = 4.8003 ｒ10= -37.0016 ｄ10= 1.2000 ｎd6 =1.61800 νd6 =63.38 ｒ11= 43.3537 ｄ11= 0.1000 ｒ12= 20.5956 ｄ12= 1.8368 ｎd7 =1.75550 νd7 =25.07 ｒ13= 92.0722 ｄ13=(可変) ｒ14= -32.2893 ｄ14= 1.2000 ｎd8 =1.45600 νd8 =90.31 ｒ15= 23.3850 ｄ15= 0.2000 ｒ16= 24.8366 ｄ16= 1.5000 ｎd9 =1.61700 νd9 =62.79 ｒ17= 90.9993 ｄ17=(可変) ｒ18= ∞（絞り） ｄ18= 0.8000 ｒ19= 17.5350（非球面） ｄ19= 4.3232 ｎd10=1.61700 νd10=62.79 ｒ20= -45.5822 ｄ20= 3.0162 ｒ21= 16.0415 ｄ21= 4.4362 ｎd11=1.61800 νd11=63.38 ｒ22= -54.3297 ｄ22= 1.1663 ｎd12=1.74077 νd12=27.79 ｒ23= 12.8583（非球面） ｄ23= 5.5553 ｒ24= -219.3134 ｄ24= 1.8801 ｎd13=1.69680 νd13=55.52 ｒ25= -34.3691 ｄ25= 6.6000 ｒ26= 92.3885 ｄ26= 1.8012 ｎd14=1.71300 νd14=53.84 ｒ27= -123.2559 非球面係数 第１９面 Ａ2= 0 Ａ4=-0.27326×10-4 Ａ6=-0.85551×10-7 Ａ8= 0 第２３面 Ａ2= 0 Ａ4= 0.67969×10-4 Ａ6= 0.12941×10-6 Ａ8= 0 Ｄ2T／ｆT ＝0.142 （第１９面） Ａ4 ＝-0.27326×10-4 （ｎa −ｎa ' ＝-0.617 ） （第２３面） Ａ4 ＝ 0.67969×10-4 （ｎa −ｎa ' ＝0.74077 ）
。Example 6 f = 9.18 ~ 24.00 ~ 70.80 F NO = 2.0 ~ 2.0 ~ 2.0 2ω = 48.24 ~ 18.64 ~ 6.36 ° r 1 = 169.2518 d 1 = 2.2000 n d1 = 1.78472 ν d1 = 25.68 r 2 = 64.9998 d 2 = 6.0000 n d2 = 1.69680 ν d2 = 56.49 r 3 = -6150.3260 d 3 = 0.1000 r 4 = 106.3196 d 4 = 4.2459 n d3 = 1.49700 ν d3 = 81.61 r 5 = 511.7991 d 5 = 0.1000 r 6 = 41.1752 d 6 = 4.8000 n d4 = 1.49700 ν d4 = 81.61 r 7 = 122.5050 d 7 = ( variable) r 8 = 187.3533 d 8 = 1.2000 n d5 = 1.72916 ν d5 = 54.68 r 9 = 11.5386 d 9 = 4.8003 r 10 = -37.0016 d 10 = 1.2000 n d6 = 1.61800 ν d6 = 63.38 r 11 = 43.3537 d 11 = 0.1000 r 12 = 20.5956 d 12 = 1.8368 n d7 = 1.75550 ν d7 = 25.07 r 13 = 92.0722 d 13 = (variable) r 14 = -32.2893 d 14 = 1.2000 n d8 = 1.45600 ν d8 = 90.31 r 15 = 23.3850 d 15 = 0.2000 r 16 = 24.8366 d 16 = 1.5000 n d9 = 1.61700 ν d9 = 62.79 r 17 = 90.9993 d 17 = (variable) r 18 = ∞ (Aperture) d 18 = 0.8000 r 19 = 1 7.5350 (aspherical surface) d 19 = 4.3232 n d10 = 1.61700 ν d10 = 62.79 r 20 = -45.5822 d 20 = 3.0162 r 21 = 16.0415 d 21 = 4.4362 n d11 = 1.61800 ν d11 = 63.38 r 22 = -54.3297 d 22 = 1.1663 n d12 = 1.74077 ν d12 = 27.79 r 23 = 12.8583 (aspherical surface) d 23 = 5.5553 r 24 = -219.3134 d 24 = 1.8801 n d13 = 1.69680 ν d13 = 55.52 r 25 = -34.3691 d 25 = 6.6000 r 26 = 92.3885 d 26 = 1.8012 n d14 = 1.71300 ν d14 = 53.84 r 27 = -123.2559 Aspherical coefficient 19th surface A 2 = 0 A 4 = -0.2732 26 × 10 -4 A 6 = -0.85551 × 10 -7 A 8 = 0 23rd surface A 2 = 0 A 4 = 0.67969 × 10 -4 A 6 = 0.12941 × 10 -6 A 8 = 0 D 2T / f T = 0.142 ( nineteenth surface) A 4 = -0.27326 × 10 -4 (n a -n a '= -0.617) ( surface No. 23) A 4 = 0.67969 × 10 -4 (n a -n a '= 0.74077)
.
【００５１】上記各実施例における前記条件（３）〜条
件（５）に関する値を次の表に示す。 。Values relating to the conditions (3) to (5) in each of the above embodiments are shown in the following table. .
【００５２】[0052]
【発明の効果】以上の説明から明らかなように、本発明
によれば、ビデオカメラやスチルビデオカメラ等に適し
た小型で高い光学性能を有する変倍比８倍程度のインナ
ーフォーカス方式のズームレンズを実現することができ
る。As is apparent from the above description, according to the present invention, a zoom lens of an inner focus type having a small zoom ratio and a high optical performance, which is suitable for a video camera, a still video camera and the like, has a zoom ratio of about 8 times. Can be realized.
【図１】本発明によるズームレンズの実施例１の広角端
（ａ）、中間焦点距離（ｂ）、望遠端（ｃ）におけるレ
ンズ断面図である。FIG. 1 is a lens cross-sectional view of Example 1 of a zoom lens according to the present invention at a wide-angle end (a), an intermediate focal length (b), and a telephoto end (c).
【図２】実施例２の広角端におけるレンズ断面図であ
る。FIG. 2 is a lens cross-sectional view at a wide-angle end according to a second exemplary embodiment.
【図３】実施例３の広角端におけるレンズ断面図であ
る。FIG. 3 is a lens cross-sectional view of Example 3 at the wide-angle end.
【図４】実施例４の広角端におけるレンズ断面図であ
る。FIG. 4 is a lens cross-sectional view at a wide-angle end according to a fourth exemplary embodiment.
【図５】実施例５の広角端におけるレンズ断面図であ
る。FIG. 5 is a lens cross-sectional view at a wide-angle end according to a fifth exemplary embodiment.
【図６】実施例６の広角端におけるレンズ断面図であ
る。FIG. 6 is a lens cross-sectional view at a wide-angle end of Example 6.
【図７】実施例１の無限遠物点に対する広角端（ａ）、
中間焦点距離（ｂ）、望遠端（ｃ）での球面収差、非点
収差、歪曲収差、倍率色収差、軸外横収差を示す収差図
である。FIG. 7 is a wide-angle end (a) with respect to an object point at infinity in Example 1.
FIG. 6 is an aberration diagram showing spherical aberration, astigmatism, distortion, lateral chromatic aberration, and off-axis lateral aberration at the intermediate focal length (b) and the telephoto end (c).
【図８】実施例１の物点距離１ｍに対する図７と同様の
収差図である。FIG. 8 is an aberration diagram similar to FIG. 7 for an object point distance of 1 m in Example 1.
【図９】実施例２の無限遠物点に対する図７と同様の収
差図である。9 is an aberration diagram similar to FIG. 7 for an object point at infinity in Example 2. FIG.
【図１０】実施例２の物点距離１ｍに対する図７と同様
の収差図である。FIG. 10 is an aberration diagram similar to FIG. 7 for an object point distance of 1 m in Example 2.
【図１１】実施例３の無限遠物点に対する図７と同様の
収差図である。FIG. 11 is an aberration diagram similar to FIG. 7 for an object point at infinity in Example 3.
【図１２】実施例３の物点距離１ｍに対する図７と同様
の収差図である。12 is an aberration diagram similar to FIG. 7 for an object point distance of 1 m in Example 3. FIG.
【図１３】実施例４の無限遠物点に対する図７と同様の
収差図である。FIG. 13 is an aberration diagram similar to FIG. 7 for an object point at infinity in Example 4.
【図１４】実施例４の物点距離１ｍに対する図７と同様
の収差図である。FIG. 14 is an aberration diagram similar to FIG. 7 for an object point distance of 1 m in Example 4.
【図１５】実施例５の無限遠物点に対する図７と同様の
収差図である。FIG. 15 is an aberration diagram similar to FIG. 7 for an object point at infinity in Example 5.
【図１６】実施例５の物点距離１ｍに対する図７と同様
の収差図である。16 is an aberration diagram similar to FIG. 7 for an object point distance of 1 m in Example 5. FIG.
【図１７】実施例６の無限遠物点に対する図７と同様の
収差図である。FIG. 17 is an aberration diagram similar to FIG. 7 for an object point at infinity in Example 6.
【図１８】実施例６の物点距離１ｍに対する図７と同様
の収差図である。FIG. 18 is an aberration diagram similar to FIG. 7 for an object point distance of 1 m in Example 6.
【図１９】従来例のレンズ構成を示すレンズ断面図であ
る。FIG. 19 is a lens cross-sectional view showing a lens configuration of a conventional example.
Ｉ…第１レンズ群 ＩＩ…第２レンズ群 ＩＩＩ…第３レンズ群 ＩＶ…第４レンズ群 I ... 1st lens group II ... 2nd lens group III ... 3rd lens group IV ... 4th lens group
【手続補正書】[Procedure amendment]
【提出日】平成５年６月２３日[Submission date] June 23, 1993
【手続補正１】[Procedure Amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００２６[Correction target item name] 0026
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００２６】また、第３レンズ群はフォーカシング作用
を持つが、近距離物点へのフォーカシングに伴う収差変
動を最小に抑え、かつ、至近距離物点へのフォーカシン
グの移動量が極端に大きくならないようにするには、第
３レンズ群の屈折力φ3 が条件（３）の第３式を満足す
ることが好ましい。もし、第３レンズ群の屈折力φ3が
条件（３）の第３式の下限の−０．７φW を越えてしま
うと、第３レンズ群で発生する諸収差を良好に補正する
ことが困難となり、フォーカシングの際の性能劣化が大
きくなる。また、上限の−０．０７φW を越えてしまう
と、至近距離物点へのフォーカシングの移動量が大きく
なるため、レンズ全系をコンパクトにすることが困難と
なる。Further, although the third lens group has a focusing action, it suppresses aberration fluctuations due to focusing on a short-distance object point to a minimum and prevents the amount of focusing movement to a close-distance object point from becoming extremely large. In order to satisfy the above condition, it is preferable that the refractive power φ 3 of the third lens group satisfies the third expression of the condition (3). If the refractive power φ 3 of the third lens group exceeds the lower limit of −0.7 φ W of the third expression of the condition (3), various aberrations generated in the third lens group can be corrected well. It becomes difficult, and the performance deterioration during focusing becomes large. On the other hand, if the upper limit of -0.07φ W is exceeded, the amount of focusing movement to the object point at the closest distance increases, making it difficult to make the entire lens system compact.
【手続補正２】[Procedure Amendment 2]
【補正対象書類名】図面[Document name to be corrected] Drawing
【補正対象項目名】図１[Name of item to be corrected] Figure 1
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【図１】 [Figure 1]
Claims (1)
ミングに際して固定の第１レンズ群、負の屈折力を持ち
ズーミングに際して光軸上を前後に移動して変倍作用を
持つ第２レンズ群、負の屈折力を持ちズーミングに際し
て光軸上を前後に移動して像面を一定に保つ作用を持つ
第３レンズ群、正の屈折力を持ちズーミングに際して固
定の第４レンズ群からなり、第４レンズ群が少なくとも
その１面が非球面であるレンズを少なくとも１枚含み、
第２レンズ群を少なくとも２枚のレンズで構成し、第３
レンズ群を物体側に繰り出すことによって近距離物点へ
フォーカシングを行い、かつ、以下の条件（１）を満足
することを特徴とするズームレンズ： （１） Ｄ2T／ｆT ＞０．０８ ただし、Ｄ2Tは物点が無限遠のときの望遠端における第
２レンズ群と第３レンズ群の間隔、ｆT は望遠端での全
系の焦点距離である。1. A first lens unit having a positive refracting power and fixed during zooming in order from the object side, and a second lens having a negative refracting power and moving back and forth along the optical axis during zooming to have a zooming action. Group, a third lens group having a negative refracting power and moving back and forth on the optical axis during zooming to keep the image surface constant, and a fourth lens group having a positive refracting power and fixed during zooming, The fourth lens group includes at least one lens whose at least one surface is an aspherical surface,
The second lens group includes at least two lenses, and the third lens group
A zoom lens characterized by performing focusing on a short-distance object point by moving the lens unit toward the object side and satisfying the following condition (1): (1) D 2T / f T > 0.08 , D 2T is the distance between the second lens group and the third lens group at the telephoto end when the object point is infinity, and f T is the focal length of the entire system at the telephoto end.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08053593A JP3339906B2 (en) | 1993-04-07 | 1993-04-07 | Zoom lens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08053593A JP3339906B2 (en) | 1993-04-07 | 1993-04-07 | Zoom lens |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06289295A true JPH06289295A (en) | 1994-10-18 |
| JP3339906B2 JP3339906B2 (en) | 2002-10-28 |
Family
ID=13721049
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP08053593A Expired - Fee Related JP3339906B2 (en) | 1993-04-07 | 1993-04-07 | Zoom lens |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3339906B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015045716A (en) * | 2013-08-28 | 2015-03-12 | 株式会社リコー | Zoom lens, imaging device and video camera for monitoring |
| JP2015049285A (en) * | 2013-08-30 | 2015-03-16 | 株式会社リコー | Zoom lens, imaging device, and video camera for monitoring |
| US9329367B2 (en) | 2014-02-25 | 2016-05-03 | Ricoh Company, Ltd. | Zoom lens, camera, and portable information terminal device |
| WO2016194110A1 (en) * | 2015-06-01 | 2016-12-08 | オリンパス株式会社 | Single-focus optical system and optical device provided with same |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106526819B (en) * | 2016-11-28 | 2019-02-19 | 河北汉光重工有限责任公司 | A kind of big multiplying power high definition continuous zooming optical camera lens of type round the clock |
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1993
- 1993-04-07 JP JP08053593A patent/JP3339906B2/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015045716A (en) * | 2013-08-28 | 2015-03-12 | 株式会社リコー | Zoom lens, imaging device and video camera for monitoring |
| JP2015049285A (en) * | 2013-08-30 | 2015-03-16 | 株式会社リコー | Zoom lens, imaging device, and video camera for monitoring |
| US9329367B2 (en) | 2014-02-25 | 2016-05-03 | Ricoh Company, Ltd. | Zoom lens, camera, and portable information terminal device |
| WO2016194110A1 (en) * | 2015-06-01 | 2016-12-08 | オリンパス株式会社 | Single-focus optical system and optical device provided with same |
| US10191258B2 (en) | 2015-06-01 | 2019-01-29 | Olympus Corporation | Single-focus optical system and optical apparatus using the same |
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| Publication number | Publication date |
|---|---|
| JP3339906B2 (en) | 2002-10-28 |
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