JPS58200208A - Small-sized wide-angle zoom lens - Google Patents
Small-sized wide-angle zoom lensInfo
- Publication number
- JPS58200208A JPS58200208A JP57084171A JP8417182A JPS58200208A JP S58200208 A JPS58200208 A JP S58200208A JP 57084171 A JP57084171 A JP 57084171A JP 8417182 A JP8417182 A JP 8417182A JP S58200208 A JPS58200208 A JP S58200208A
- Authority
- JP
- Japan
- Prior art keywords
- lens
- lens group
- zoom
- group
- wide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B15/00—Optical objectives with means for varying the magnification
- G02B15/14—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective
- G02B15/16—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective with interdependent non-linearly related movements between one lens or lens group, and another lens or lens group
- G02B15/177—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective with interdependent non-linearly related movements between one lens or lens group, and another lens or lens group having a negative front lens or group of lenses
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B15/00—Optical objectives with means for varying the magnification
- G02B15/14—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective
- G02B15/143—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having three groups only
- G02B15/1435—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having three groups only the first group being negative
- G02B15/143503—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having three groups only the first group being negative arranged -+-
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Nonlinear Science (AREA)
- Lenses (AREA)
Abstract
Description
【発明の詳細な説明】
本発明はズームレンズに関し・：寺に物体側よシ順に発
散性の第ルンズ群、収斂性の第２レンズ群そして発散性
の第３レンズ群の３つのレンズ群で構成し、第ルンズ群
と第２レンズ群を光軸上移動させてズーミングを行った
小型化を図った広角ズームレンズに関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a zoom lens, which consists of three lens groups: a diverging lens group, a convergent second lens group, and a diverging third lens group in order from the object side. The present invention relates to a compact wide-angle zoom lens in which zooming is performed by moving a first lens group and a second lens group on the optical axis.
従来から小型化を図ったズームレンズとして、発散性の
第ルンズ群と収斂性の第２レンズ群２つのレンズ群で構
成し、両レンズ群の間隔を変えてズーミングを行ういわ
ゆる２群方式のズームレンズがあシ、数多く提案されて
いる。本出願人も特開昭５３−１３２３６０号や特開昭
５６−１９０２２号等で提案している。前者は発散性の
物体側の第ルンズ群を３枚のレンズ構成とし、ある程度
パワーを強め、望遠端のズーム位置における両レンズ群
間の主点間隔をある程度小さくすることによりズームレ
ンズの前玉径およびレンズ全長（第ルンズ面から像面壕
での長さ）特に広角端のズーム位置でのレンズ全長をコ
ンパクトにしている。一方後者はズーミングにおいて物
体側の第ルンズ群を光軸上直線的に移動させ望遠端のズ
ーム位置でのレンズ全長のコンパクト化を図っており、
発散性の物体側の第ルンズ群のパワ」：１は前者のズー
ムレンズに比べ弱くなっている。ズームレンズ系のコン
パクト化を図る場合、前者では発散性の物体側の第ルン
ズ群のパワーをさらに強くすれば広角端のズーム位置で
のレンズ全長はさらに短かくなるが、逆に望遠端のズー
ム位置でのレンズ全長は長くなり、ついには広角端のズ
ーム位置でのレンズ全長よシも長くなってしまう。一方
後者では望遠端のズーム位置でのレンズ全長の短縮化に
は好ましいが広角端のズーム位置でのレンズ全長が長く
なる傾向があシ更にズームレンズの前玉径が大きくなり
好ましくない。一般には２群方式のズームレンズにおい
てズームレンズのレンズ全長を最も効率良く短くするに
は広角端と望遠端の両方のズーム位置でのレンズ全長が
等しくなるようにするのがよい。As a conventional zoom lens that has been designed to be more compact, it is a so-called two-group zoom that consists of two lens groups: a diverging lens group and a convergent second lens group, and performs zooming by changing the distance between both lens groups. Many lenses have been proposed. The present applicant has also proposed this in Japanese Patent Application Laid-open Nos. 53-132360 and 1987-19022. The former uses a three-lens configuration for the diverging object-side lens group, increases the power to some extent, and reduces the principal point distance between both lens groups to some extent at the telephoto end zoom position, thereby reducing the diameter of the front lens of the zoom lens. The total lens length (length from the first lens surface to the image plane groove), especially at the wide-angle end zoom position, has been made compact. On the other hand, the latter moves the object-side lens group linearly on the optical axis during zooming, thereby reducing the overall length of the lens at the telephoto end zoom position.
The power of the divergent object-side lens group ":1" is weaker than that of the former zoom lens. When trying to make a zoom lens system more compact, in the case of the former, if the power of the diverging object-side lens group is made even stronger, the total lens length at the wide-angle end zoom position becomes even shorter, but conversely, the overall length of the lens at the telephoto end zoom position becomes shorter. The total length of the lens becomes longer at the zoom position, and eventually the total length of the lens at the wide-angle end zoom position also becomes longer. On the other hand, the latter is preferable for shortening the total lens length at the telephoto end zoom position, but it tends to increase the lens total length at the wide-angle end zoom position, and is also undesirable because it increases the diameter of the front lens of the zoom lens. Generally, in a two-group zoom lens, in order to most efficiently shorten the total lens length of the zoom lens, it is preferable to make the total lens lengths equal at both the wide-angle end and the telephoto end.
本発明は２群方式のズームレンズの特徴を採用し、レン
ズ全長の短縮化を図る為、新たなレンズ構成を採用しつ
つ光学性能の極めて良い広角ズ」ムレンズの提供を目的
とするものである。The present invention aims to provide a wide-angle zoom lens that employs the characteristics of a two-group zoom lens, employs a new lens configuration to shorten the overall length of the lens, and has extremely good optical performance. .
本発明の目的を達成する為のズームレンズのレンズ構成
の特徴は物体側より順に、発散性の １第ルンズ
群、収斂性の第２レンズ群そして発散性の第３ノンズ群
の３つのレンズ群で構成し、前記第ルンズ群と第２レン
ズ群を光軸上移動させてズーミングを行なうものである
。The features of the lens configuration of a zoom lens to achieve the object of the present invention are three lens groups, in order from the object side: a diverging first lens group, a convergent second lens group, and a diverging third lens group. The zoom lens is configured by moving the first lens group and the second lens group on the optical axis to perform zooming.
本発明のズームレンズの構成を前記従来例の２群方式の
ズームレンズと比較してみると収斂性の像側の第２レン
ズ群を収斂性のレンズ群と発散性のレンズ群の２つのレ
ンズ群に分ケ、分割した収斂性のレンズ群のみを発散性
の第ルンズ群と共に光軸上移動させズーミングを行なう
のと同じ構成になる。本発明のズームレンズの構成をこ
のように考えることもできるが、本発明のズームレンズ
の構成はズームレンズの小型化を図りつつ光学性能の向
上を図る為に案出された新しいタイプのズームレンズな
のである。Comparing the configuration of the zoom lens of the present invention with the conventional two-group zoom lens, it is found that the convergent second lens group on the image side is composed of two lenses: a convergent lens group and a diverging lens group. The configuration is the same as that in which only the divided convergent lens group is moved along the optical axis along with the diverging lens group to perform zooming. Although the configuration of the zoom lens of the present invention can be considered in this way, the configuration of the zoom lens of the present invention is a new type of zoom lens devised to improve optical performance while reducing the size of the zoom lens. That's why.
すなわち、従来より第１図に示すように発散性の第ルン
ズ群、収斂性の第２レンズ群そして発散性の第３レンズ
群の３つのレンズ群よりなり、第２レンズ群と第３レン
ズ群を物体側方向へ移動させ、第ルンズ群を非直線的に
移動させてズーミングを行うズームレンズが知られてい
る。このようなズーム方式においてズーム比をある程度
保つには第２レンズ群の移動量をふやすと同時に第ルン
ズ群と第３レンズ群を同図の点線の矢印の如く移動させ
る必要がある。That is, as shown in FIG. 1, conventionally it consists of three lens groups: a diverging lens group, a convergent second lens group, and a diverging third lens group. A zoom lens is known that performs zooming by moving the lens toward the object side and moving the lens group non-linearly. In order to maintain a certain zoom ratio in such a zoom system, it is necessary to increase the amount of movement of the second lens group and at the same time move the lens group and the third lens group as indicated by dotted line arrows in the figure.
この場合筒ルンズ群の位置は広角端より望遠端の方が物
体側前方へ出る傾向になり、望遠端でのレンズ全長が長
くなり大型化してしまう。In this case, the position of the cylindrical lens group tends to be farther forward on the object side at the telephoto end than at the wide-angle end, and the overall length of the lens at the telephoto end becomes longer and larger.
次に第３レンズ群のズーム移動量を減らしていくと第ル
ンズ群は像側方向への移動量がふえてくるため、第２レ
ンズ群の少ないズーム移動量で、ある程度のズーム比を
保つことが出来る０
本発明のズームレンズはこのようなズームレンズの性質
を利用し、ズームレンズの小型化を図りつつ高性能な光
学性能を得る目的で、創作されたものであり、第３レン
ズ群をズーミング中固定とし、このときのズームレンズ
の性質トいわゆる２群方式のズームレンズの特徴を採り
つつ極めて小型でしかも良好に収差補正を達成した広角
ズームレンズなのである。Next, as the amount of zoom movement of the third lens group is reduced, the amount of movement of the third lens group toward the image side increases, so it is necessary to maintain a certain zoom ratio with a small amount of zoom movement of the second lens group. 0 The zoom lens of the present invention was created for the purpose of achieving high optical performance while downsizing the zoom lens by taking advantage of the characteristics of the zoom lens. It is a wide-angle zoom lens that is fixed during zooming and has the characteristics of a so-called two-group zoom lens, and is extremely compact and achieves excellent aberration correction.
次に本発明に係るズームレンズ構成を従来よシズームレ
ンズの小型化を図るには有利とされているいわゆる２群
方式のズームレンズを例にとシこの２群方式のズームレ
ンズと比較しつつ本発明に係るズームレンズが更に小型
化に適している事を各図を用いて説明する。Next, we will compare the zoom lens configuration according to the present invention with a two-group zoom lens, taking as an example a so-called two-group zoom lens, which is considered to be advantageous in reducing the size of conventional zoom lenses. The fact that the zoom lens according to the present invention is suitable for further miniaturization will be explained with reference to the figures.
第２図（ａ）、 （ｂ）は従来の２群方式のズームレン
ズと本発明に係るズームレンズの説明図でありＩは正の
第ルンズ群、■は負の第２レンズ群、Ｆはフィルム面で
ある。同図（ｂ）に示すように収斂性の像側の第２レン
ズ群■を正と負のレンズ群■１と■□に分割し本発明に
係るズームレンズと同様のレンズ構成として考えると、
この分割したレンズ群自体はテレフォトタイプのレンズ
構成になるためにフィルム面Ｆまでの距離は短くなシＦ
′の位置にくるのでバックフォーカスは短くなる。これ
によって広角端と望遠端の両方のズーム位置でともにレ
ンズ・全長を短縮することが可能となる。第３図（ａ）
ｔ （ｂ）、第４図（ａ）ｔ （ｂ）はズーミングに
よるレンズ群の移動量の説明である。第３図（ｂ）に示
すように分割した収斂性レンズ群のパワーは分割した他
方のレンズ群が負である為に分割する前のレンズ群のパ
ワーより当然強くなっているため、第３図（ａ）に比べ
て少ない移動量で同じズーム比を達成することが出来る
。これによって広角端のズーム位置での発散性レンズ群
と分割した収斂性のレンズ群の主点間隔を△Ｄ、だけ小
さくすることが出来、この結果レンズ全長の短縮化を図
ることができる。FIGS. 2(a) and 2(b) are explanatory diagrams of a conventional two-group zoom lens and a zoom lens according to the present invention, where I is the positive lens group, ■ is the negative second lens group, and F is the negative second lens group. This is the film side. As shown in FIG. 6(b), if the convergent image-side second lens group ■ is divided into positive and negative lens groups ■1 and ■□, and the lens configuration is similar to the zoom lens according to the present invention,
This divided lens group itself has a telephoto type lens configuration, so the distance to the film plane F is short.
′ position, so the back focus becomes short. This makes it possible to shorten the overall lens length at both the wide-angle end and the telephoto end. Figure 3(a)
t(b) and FIGS. 4(a) and 4(b) illustrate the amount of movement of the lens group due to zooming. As shown in Figure 3(b), the power of the divided convergent lens group is naturally stronger than the power of the lens group before division because the other divided lens group is negative. The same zoom ratio can be achieved with a smaller amount of movement than in (a). As a result, the distance between the principal points of the diverging lens group and the divided convergent lens group at the zoom position at the wide-angle end can be reduced by ΔD, and as a result, the overall length of the lens can be shortened.
又本発明に係るズームレンズでは、仮υに発散性筒ルン
ズ群のパワーが従来の２群方式のズームレンズにおける
発散性の第ルンス群のパワーと同一であっても第２レン
ズ群のパワーが強くなるのでレンズ全長の短縮化が有利
となる。そして従来の２群方式のズームレンズにおいて
第ルンズ群のパワーを強くして広角端のズーム位置での
レンズ全長を望遠端のズーム位置でのレンズ全長と同じ
にしてズームレンズの小型化を効率良く打づた場合よシ
もさらに本発明のズームレンズはレンズ全長の短縮化を
図ることが可能となる。Furthermore, in the zoom lens according to the present invention, even if the power of the diverging cylindrical lens group is the same as the power of the diverging lens group in a conventional two-group zoom lens, the power of the second lens group is As the strength increases, it is advantageous to shorten the overall length of the lens. In conventional two-group zoom lenses, the power of the second lens group is increased to make the total lens length at the wide-angle end the same as the lens length at the telephoto end, making it possible to efficiently downsize the zoom lens. In addition, the zoom lens of the present invention allows the overall length of the lens to be shortened.
前述の如く、本発明に係るズームレンズでは従来（０２
２群方のズームレンズに比べて収斂性デ〕く
第２レンズ群の移動量を少なくてもズーム比を達成する
ことが出来るため、広角端のズーム位置を基準とした時
、望遠端のズーム位置での発散性筒ルンズ群Ｉの位置は
第４図（ａ）に示す従来例に対し第４図（ｂ）に示すよ
うにΔＤ、だけよシ像側にくる。従って望遠端でのレン
ズ全長が広角端のレンズ全長より短かくなるため広角端
のレンズ全長の短縮の余裕が生まれ発散性第ルンス群の
パワーをさらに強くしてレンズ全長の短縮がはかれる。As mentioned above, the zoom lens according to the present invention
Compared to a two-group zoom lens, it has less convergence and can achieve the zoom ratio with less movement of the second lens group. The position of the diverging tube lens group I is further ΔD toward the image side, as shown in FIG. 4(b), compared to the conventional example shown in FIG. 4(a). Therefore, since the total lens length at the telephoto end is shorter than the total lens length at the wide-angle end, there is a margin for shortening the total lens length at the wide-angle end, and the power of the diverging Luns group is further strengthened to shorten the total lens length.
以上本発明に係るズームレンズの基本的特徴について簡
単のため従来の２群方式のズームレンズと比較して説明
した。The basic features of the zoom lens according to the present invention have been described above in comparison with a conventional two-group zoom lens for simplicity.
一方、本発明に係るズームレンズを３つのレンズ群から
構成し、第ルンズ群と第２レンズ群を移動させてズーミ
ングを行い第３レンズを固定したものとして考えてもよ
いことは前述の第１図の説明で述べたようにさしつかえ
ないことはいうまでもない。On the other hand, it is also possible to consider the zoom lens according to the present invention to be composed of three lens groups, with the first lens group and the second lens group moving to perform zooming, and the third lens being fixed. It goes without saying that this is not a problem as mentioned in the explanation of the figure.
本発明に係るズームレンズは以上のレンズ構成で小型化
と良好力る収差補正を達成することができるものである
が、更に良好なる光学性能を得る為には次の条件を満足
するのが好ましい。The zoom lens according to the present invention can achieve miniaturization and good aberration correction with the lens configuration described above, but in order to obtain even better optical performance, it is preferable to satisfy the following conditions. .
まず、第３レンズ群の焦点距離をｆ□としだ時ｌ ｆＴ
ｌｌｌを望遠端のズーム位置での焦点距離ｆＴよシ大き
くすなわちｌ ｆｍＩ≧ｆＴとすることである。First, let f□ be the focal length of the third lens group, then l fT
lll is larger than the focal length fT at the telephoto end zoom position, that is, l fmI≧fT.
これは第２レンズ群のパワーを制約し、この第２レンズ
群から発生する収差量が極端に大きくならない様にする
ための条件であシ更に広角端でのバックフォーカスを必
要量保つための条件でもある。この範囲以外になると第
２レンズ群から発生する収差量が極端に増加しズームレ
ンズ全体としての収差を良好に補正することができなく
なり、また、バックフォーカスが短かくなり過ぎ、広角
端においては３５ミＩＪＴＴＬ −眼レフカメラに装着
した時ミラーアップが困難になってしまう。次に第ルン
ズ群の焦点距離をｆＩとしだ時１ｆ１１はｆＴより小さ
くすなわち１ｆＩｌ＜ｆＴとすることである。これはレ
ンズ全長の短縮化およびズームレンズの前玉径の縮小を
はかるための条件である。この条件より外れると広角端
のズーム位置でのレンズ全長、およびズームレンズの前
玉径が大きくなり過ぎコンパクト化が困難となる。さら
に後述する本発明の実施例の如くズーム比が２倍以下で
開放ＦナンバーがＦ／４程度のときは発散性第３レンズ
群を少なくとも正レンズと負レンズで構成するのが好ま
しい。これはズームレンズ全系の収差の悪化しない範囲
内でなるべくレンズ枚数を少なくしてズームレンズ全系
をコンパクトにする為である。This is a condition to limit the power of the second lens group and prevent the amount of aberration generated from this second lens group from becoming extremely large.It is also a condition to maintain the necessary amount of back focus at the wide-angle end. There is also. Outside this range, the amount of aberrations generated by the second lens group increases dramatically, making it impossible to properly correct the aberrations of the zoom lens as a whole, and the back focus becomes too short, with 35mm at the wide-angle end. Mi IJTTL - When attached to an eye-reflex camera, mirror-up becomes difficult. Next, when the focal length of the lens group is fI, 1f11 is smaller than fT, that is, 1fIl<fT. This is a condition for shortening the overall lens length and reducing the diameter of the front lens of the zoom lens. If this condition is not met, the overall length of the lens at the wide-angle end zoom position and the diameter of the front lens of the zoom lens become too large, making it difficult to make it compact. Further, when the zoom ratio is 2 times or less and the open F-number is about F/4 as in the embodiment of the present invention described later, it is preferable that the diverging third lens group is composed of at least a positive lens and a negative lens. This is to make the entire zoom lens system compact by reducing the number of lenses as much as possible within a range that does not worsen the aberrations of the entire zoom lens system.
また第２レンズ群内に開口絞シを持つ場合には第ルンズ
群のパワーがある程度強いため広角端において樽型の歪
曲収差が多く発生し易くなるため、この歪曲収差を開口
絞りよｐ像側にある第３レンズ群で曳好楔補正すること
が可能となる。このときの補正を効果的に行うにも第３
レンズ群を少なくとも１枚の正レンズと負レンズのレン
ズ構成にして行うのが好ましい。In addition, when the second lens group has an aperture stop, the power of the second lens group is strong to some extent, so barrel-shaped distortion tends to occur at the wide-angle end. It becomes possible to perform drag wedge correction with the third lens group located at In order to effectively perform the correction at this time, the third
It is preferable to configure the lens group with at least one positive lens and one negative lens.
そして第３レンズ群の物体側の第ルンズ面から最終レン
ズ面までの厚さをｔとしたとき０．０４≦ｔ／ｆＴ≦０
．２５・・・（１）の範囲内に第３レンズ群を構成する
のが好ましい。これは良好なる収差補正を行いつつ、レ
ンズ系全体のコンパクト化を図る為である。And when the thickness from the object-side lens surface to the final lens surface of the third lens group is t, 0.04≦t/fT≦0
．． 25...(1) It is preferable to configure the third lens group within the range of (1). This is to make the entire lens system more compact while performing good aberration correction.
条件式（１）の上限値を越えると第３レンズ群の厚さが
増加してレンズ系全体のコンパクト化を図るのに好まし
くなく、又、下限値を越えるとレンズ厚が薄くなシすぎ
所定の曲率半径を有したレンズを構成し、良好なる収差
補正を達成するのが困難となる。If the upper limit of conditional expression (1) is exceeded, the thickness of the third lens group will increase, which is unfavorable for making the entire lens system compact, and if the lower limit is exceeded, the lens thickness will be too thin. It becomes difficult to construct a lens having a radius of curvature of
更に本発明におけるズームレンズの光学性能を良好に保
ちながらズームレンズ系全体をコンパクトにするために
は、屈折力の強い発散性第１し／ズ群を極めて単純なレ
ンズ構成でしかもこのレンズ群から発生する収差量を出
来るだけ少なくおさえるため、第ルンズ群を物体側よ
１シ順に物体側に凸面を向けたメニスカス状の第
１負レンズ、両レンズ面が凹面の第２負レンズそして物
体側に凸面を向けたメニスカス状の第３正レンズで構成
することである。Furthermore, in order to make the entire zoom lens system compact while maintaining good optical performance of the zoom lens according to the present invention, it is necessary to use a highly divergent first lens group having a strong refractive power with an extremely simple lens structure and from this lens group. In order to minimize the amount of aberration that occurs, the lens group is moved closer to the object side.
The lens is constructed of, in order, a meniscus-shaped first negative lens with a convex surface facing the object side, a second negative lens with both lens surfaces concave, and a meniscus-shaped third positive lens with a convex surface facing the object side.
そして第２負レンズと第３正レンズとで作る空気間隔で
収斂作用の空気レンズとしておくことが望遠端での諸収
差を良好に補正するのに好ましい。又、第２レンズ群を
物体側よシ順に２枚以上の正レンズ、負レンズそして正
レンズで構成するのが全ズーム範囲で良好に収差補正す
るのに好ましい。It is preferable to use the air gap formed by the second negative lens and the third positive lens to form an air lens with a convergence effect in order to satisfactorily correct various aberrations at the telephoto end. Further, it is preferable that the second lens group is composed of two or more positive lenses, a negative lens, and a positive lens in order from the object side, in order to properly correct aberrations over the entire zoom range.
次に、第ルンズ群と第３レンズ群の屈折力配分を
の範囲内にしておくことがレンズ系全体を小型化にし、
かつ全ズーム範囲で良好な収差補正をしつつ、変倍によ
る収差変動を少なくするのに好ましい。Next, keeping the refractive power distribution of the lens group and the third lens group within the range allows the entire lens system to be made smaller.
Moreover, it is preferable to perform good aberration correction over the entire zoom range and to reduce aberration fluctuations due to zooming.
条件式（２）の下限値以下では広角端よシ望遠端の方が
レンズ全長が長くなる傾向となり、さらに望遠端での球
面収差を良好に補正することがむずかしくなる。上限値
以上では負角端のレンズ全長の短縮化が不足し好ましく
ない。Below the lower limit of conditional expression (2), the total length of the lens tends to be longer at the wide-angle end than at the telephoto end, and furthermore, it becomes difficult to satisfactorily correct spherical aberration at the telephoto end. If it exceeds the upper limit, the overall length of the lens at the negative angle end will not be shortened enough, which is not preferable.
条件式（３）の下限値以下では広角端でのバックフォー
カスを必要量取ることがむずかしくなシ、さらに第３レ
ンズ群を性能上、簡単なレンズで構成することが困難に
なる。上限値以上ではこの第３レンズ群のパワーが弱く
なり過ぎ、コンパクト化の効果がうすれて来る。また、
第ルンズ群と第３レンズ群を上記のようなレンズ構成と
することは各レンズ群内で球面収差の発生をある程度除
去しズーミングによる球面収差の変動を良好に補正する
ためである。Below the lower limit of conditional expression (3), it is difficult to obtain the necessary amount of back focus at the wide-angle end, and furthermore, it becomes difficult to configure the third lens group with a simple lens in terms of performance. If the upper limit is exceeded, the power of this third lens group becomes too weak, and the effect of compactness is diminished. Also,
The reason why the lens group and the third lens group are configured as described above is to eliminate the occurrence of spherical aberration to some extent within each lens group and to satisfactorily correct fluctuations in spherical aberration due to zooming.
次に第３レンズ群の収差論的作用効果について説明する
。後述する本発明の実施例２について開口絞）を第２レ
ンズ群の物体側よシ数えて第１番目と第２番目のレンズ
間に設けた時の第１、第２および第３レンズ群の５ｅｉ
ｄｅ７！の３次収差係数を表１に示す。Next, the aberrational effects of the third lens group will be explained. Regarding Example 2 of the present invention, which will be described later, the first, second, and third lens groups when the aperture stop (aperture stop) is provided between the first and second lenses counting from the object side of the second lens group. 5ei
de7! Table 1 shows the third-order aberration coefficients.
忌■ きＭｌ へ藁動 Φ龜
滅−城ｃ４ 城の
表１に示す如く、第３レンズ群はズーミング中であって
も球面収差（ＳＡ）は一定であるが非点収差（ＡＳ）と
歪曲収差（ＤＳ）はともに補正過剰方向へ作用し非点収
差（Ａｓ）はその作用が広角側で強く望遠側では少なく
なっている。本発明に係るズームレンズにおいては第ル
ンズ群と第２レンズ群のパワーをある程度強くしている
ので第ルンズ群と第２レンズ群の合わさったレンズ系か
ら特に広角端において補正不足の非点収差が発生し易く
なるため、このときの収差補正のため上記第３レンズ群
の作用が極めて効果的となる。また広角端において樽型
の歪曲も発生し易くなるのでこの補正にも有効である。As shown in Table 1, the third lens group has constant spherical aberration (SA) even during zooming, but astigmatism (AS) and distortion Both aberrations (DS) act in the direction of overcorrection, and astigmatism (As) has a stronger effect on the wide-angle side and less on the telephoto side. In the zoom lens according to the present invention, the powers of the first lens group and the second lens group are strengthened to a certain extent, so that the lens system in which the first lens group and the second lens group are combined prevents astigmatism that is undercorrected, especially at the wide-angle end. Since this is likely to occur, the action of the third lens group becomes extremely effective for correcting aberrations at this time. It is also effective in correcting barrel-shaped distortion, which tends to occur at the wide-angle end.
このように本発明に係るズームレンズにおいては、第３
レンズ群は第ルンズ群および第２レンズ群から発生する
収差を打ち消す作用効果、□・ １１
を持っている。この為従来のレンズ全系で収差補正を行
った２群方式の構成のズームレンズにおいて、ズームレ
ンズと像面の間にいわゆるリア・アタッチメントレンズ
（これのみで収差が除去されている）を装着し全レンズ
系の焦点距離を変化させる単なる３つのレンズ群よシな
るズームレンズと比べてみても本発明のズームレンズは
根本的に目的及び作用効果を異にしており、単に負と正
のレンズ群からなるズームレンズの後方に新たなレンズ
群を付加し、焦点距離を変化させたものとは格別の作用
効果の違いがある。In this way, in the zoom lens according to the present invention, the third
The lens group has an effect of canceling out aberrations generated from the first lens group and the second lens group, □.11. For this reason, in conventional zoom lenses with a two-group structure in which aberrations are corrected in the entire lens system, a so-called rear attachment lens (which alone eliminates aberrations) is attached between the zoom lens and the image plane. Even when compared to a zoom lens that is simply a three-lens group that changes the focal length of the entire lens system, the zoom lens of the present invention has fundamentally different purposes and effects; it simply has a negative and a positive lens group. This has a particularly different effect from adding a new lens group to the rear of a zoom lens and changing the focal length.
本発明では以上のようなレンズ構成とすることによシ、
後述する実施例に示す如く、画角６２゜〜３５．３°、
Ｆナンバー１：４〜４．５で広角端のレンズ全長が望遠
端の焦点距離の１．４倍程度という極めてコンパクトで
しかも性能良好なる広角ズームレンズが実現可能となる
。In the present invention, by having the lens configuration as described above,
As shown in the examples described later, the angle of view is 62° to 35.3°,
With an F number of 1:4 to 4.5, it is possible to realize an extremely compact wide-angle zoom lens whose total lens length at the wide-angle end is about 1.4 times the focal length at the telephoto end, and which has good performance.
尚、フォーカシングは、レンズ全体を繰り出して行って
も良く、又第３レンズを固定し、第ルンズと第２レンズ
を繰り出して行うことも又第ルンズ群あるいは第２レン
ズ群のみを繰り出して行ってもよい。Note that focusing may be performed by extending the entire lens, or by fixing the third lens and extending the lens and second lens, or by extending only the lens group or the second lens group. Good too.
次に本発明の数値実施例を示す。数値実施例においてＲ
ｉは物体側より順に第１番目のレンズ面の曲率半径、Ｄ
量は物体側よシ順に第１番目のレンズ厚及び空気間隔、
Ｎｉとν・は夫々物体側より順に第１番目のレンズのガ
ラスの屈折率と実施例Ｉ
Ｆ−１００−１８９ＦＮＯ−１：４−４．５ ２Ｌ
Ｌｌ−６２−３５，３Ｒ１−８４，８２５Ｄ １−
４．１７ Ｎ １−１．６９６８０ ν
１− ５５．５Ｒ２−４２，３５６Ｄ ２− １４．
７７Ｒ３−−２６９，８７４Ｄ３− ３．３３
Ｎ２−１．６９６８０ ν ２− ５５．
５Ｒ４−２５３，７５１Ｄ ４請 １．２０Ｒ５
−６４，６８１Ｄ ５− ５．１８ Ｎ
３賞１．６４７６９ ν ３− ３３．８Ｒ
６−１４６，３７４Ｄ ６−可変
Ｒ７−８２，７９３Ｄ ７− ８．５５ Ｎ ４論１
．６５８４４ ν４−５０．９１８− −２５４．７
５８ Ｄ ８− ０＋４２Ｒ９−５１，６７１Ｄ
９− ８．７０ Ｎ Ｓ−１，６６８９２ν５−４
５．０ＲＩＯ−２２８，８１９ＤＩＯ−５，８０Ｒ１１
−−２９２，３２５Ｄｌｌ−１０，０１Ｎ ６−１．８
４６６６ ジロー ２３．９Ｒ１２−４３，４６２Ｄ
１２− １２．２７Ｒ１３−３６４，５５３Ｄ１３−
７．５６ −Ｎ ７−１．６３６３６ シアー ３５
．４Ｒ１４−−７４，８７７Ｄ１４−可変
Ｒ１５−−６５８，０８４Ｄ１５− ２．７８ Ｎ８
−１．６０３１１ νｇ−６０，７３１６−９８，７
５４Ｄ１６− １．０４Ｒ１７−１１３，４２２Ｄ１
７− ８．３３ Ｎ ９−１．５７０９９ ν９−
５０．８Ｒ１８−−４２７８，６０９
実施例２
Ｆ−１００−１８９ＦＮＯ−１＝４−４．５
２ｕＪ＝ ６２−３５．３Ｒ１−８５，４９６Ｄ
１− ４．１７ Ｎ １噛１．６９６
８０ ν １− ５５．５Ｂ ２− ４４
．５４３ Ｄ ２− １９．１４Ｒ３−−２４４
，１５３Ｄ ３− ３．３３ Ｎ ２−１．６９
６８０ ν２−５５．５Ｒ４−３９５，０６４Ｄ
４− ０．１６Ｒ５−６６，００７Ｄ ５−
５．８２ Ｎ ３−１．７５５２０ ν３
−２７．５Ｒ６−１０５，２１９Ｄ ６−可変
Ｒ７−７５，９９１Ｄ ７− ８．３１ Ｎ
４謹１．６２２９９ ν ４− ５８．２
Ｒ８−−３４１，５７７Ｄ８− ５．５６Ｒ９−５
４’、２３５ Ｄ ９− ５．０８ Ｎ
５−１．６７００３ ν ５−４７．３ＲＩＯ−
９８，１５６ＤＩＯ−０，４２ａｌｌ−５８，１６３Ｄ
ｌｌ−４，２８Ｎ ６−１．５１７４２ ν
６− ５２．４８１２− １１４．４８０
Ｄ１２− ３．５２Ｒ１３霞 −７７２，２８９Ｄ１
３− ７．０２ Ｎ ？−１，８４６６６ν
７−２３．９Ｒ１４−４２，４８９Ｄ１４− １３．
６２Ｒ１５−２２１，２７６Ｄ１５− ６．１２
Ｎ ８−１．６８８９３ ν ８−３１．１
Ｒ１６−−９４，５５８Ｄ１６−可変
ＩＬ１７− ８３３．３３４ Ｄ１７− ２
．７８ Ｎ ９−１．５８９１３ ν ９−
６１．０Ｒ１８−９１，６６７Ｄ１８− ２．２２Ｒ
１９−１１２，０８３ＤＩＯ−８，３３Ｎｌ０−１．５
６８８３ ν１０−５６．３Ｒ２０−−２７７，
７７８Ｄ２０− ２．７８ Ｎ１１−１．５
８２６７ ν１１榔 ４６＋４Ｒ２１−４６４
二３０９Next, numerical examples of the present invention will be shown. In numerical examples R
i is the radius of curvature of the first lens surface from the object side, D
The amount is the first lens thickness and air distance in order from the object side,
Ni and ν are the refractive index of the glass of the first lens and Example I F-100-189FNO-1: 4-4.5 2L, respectively, in order from the object side.
Ll-62-35,3R1-84,825D 1-
4.17 N 1-1.69680 ν
1-55.5R2-42,356D 2-14.
77R3--269,874D3- 3.33
N2-1.69680 ν 2- 55.
5R4-253,751D 4 contract 1.20R5
-64,681D 5- 5.18N
3rd prize 1.64769 ν 3- 33.8R
6-146,374D 6-Variable R7-82,793D 7-8.55 N 4 Theory 1
．． 65844 ν4-50.918- -254.7
58 D 8- 0+42R9-51,671D
9- 8.70 N S-1,66892ν5-4
5.0RIO-228,819DIO-5,80R11
--292,325Dll-10,01N 6-1.8
4666 Jiro 23.9R12-43,462D
12- 12.27R13-364,553D13-
7.56 -N 7-1.63636 Shear 35
．． 4R14--74,877D14-Variable R15--658,084D15- 2.78 N8
-1.60311 νg-60,7316-98,7
54D16- 1.04R17-113,422D1
7- 8.33 N 9-1.57099 ν9-
50.8R18--4278,609 Example 2 F-100-189FNO-1=4-4.5
2uJ=62-35.3R1-85,496D
1- 4.17 N 1 bite 1.696
80 ν 1- 55.5B 2- 44
．． 543 D 2- 19.14R3--244
, 153D 3- 3.33 N 2-1.69
680 ν2-55.5R4-395,064D
4- 0.16R5-66,007D 5-
5.82 N 3-1.75520 ν3
-27.5R6-105,219D 6-Variable R7-75,991D 7-8.31 N
4 yen 1.62299 ν 4- 58.2
R8--341,577D8- 5.56R9-5
4', 235 D 9- 5.08 N
5-1.67003 ν 5-47.3RIO-
98,156DIO-0,42all-58,163D
ll-4,28N 6-1.51742 ν
6- 52.4812- 114.480
D12- 3.52R13 Haze -772,289D1
3-7.02 N? -1,84666ν
7-23.9R14-42,489D14- 13.
62R15-221, 276D15- 6.12
N 8-1.68893 ν 8-31.1
R16--94,558D16-Variable IL17- 833.334 D17-2
．． 78 N 9-1.58913 ν 9-
61.0R18-91,667D18-2.22R
19-112,083DIO-8,33Nl0-1.5
6883 ν10-56.3R20--277,
778D20- 2.78 N11-1.5
8267 ν11 46+4R21-464
2309
第１図ハ従来のズームレンズのズーム方式の説明図、第
２図（ａ）、 （ｂ）、第３図（ａ）ｖ （ｂ）、第４
図（ａ）、 （ｂ）は各々従来のズームレンズのレンズ
構成と本発明に係るズームレンズのレンズ構成の比較の
為の説明図、第５図と第６図は各々本発明の実施例１と
実施例２のレンズ断面図、第７図（ａ）ｔ （ｂ）ｙ
（ｃ）と第８図（１ｋ） ｔ （ｂ） ｓ （ｃ）は各
々本発明の実施例１と実施例２の広角端、中間、望遠端
のズーム位置での諸収差図である。
図中、Ｍはメリデイオナル像面、Ｓはサジタル像面であ
る。
特許出願人 キャノン株式会社Fig. 1 C is an explanatory diagram of the zoom system of a conventional zoom lens, Fig. 2 (a), (b), Fig. 3 (a) v (b), Fig. 4
Figures (a) and (b) are explanatory diagrams for comparison between the lens configuration of a conventional zoom lens and the zoom lens according to the present invention, and Figures 5 and 6 are respectively illustrations of Example 1 of the present invention. and lens cross-sectional view of Example 2, FIG. 7 (a) t (b) y
(c) and FIG. 8(1k) t (b) s (c) are various aberration diagrams at the wide-angle end, intermediate, and telephoto end zoom positions of Example 1 and Example 2 of the present invention, respectively. In the figure, M is a meridional image plane, and S is a sagittal image plane. Patent applicant Canon Co., Ltd.
Claims (5)
第２レンズ群そして発散性の第３レンズ群の３つのレン
ズ群で構成し、前記第ルンズ群と第２レンズ群を光軸上
移動させてズーミングを行なうことを特徴とする小型の
広角ズームレンズ。(1) In order from the object side, it is composed of three lens groups: a diverging lens group, a convergent second lens group, and a diverging third lens group, and the first lens group and the second lens group are used to A compact wide-angle zoom lens that performs zooming by moving on the axis.
のズーム位置における焦点距離をｆＴとしだ時ｌ ｆＩ
ＩＩｌ≧ｆ、ｒなる条件を満足することを特徴とする特
許請求の範囲第１項記載の小型の広角ズームレンズ。(2) When the focal length of the third lens group is fII11 and the focal length at the telephoto end zoom position is fT, then l fI
A small wide-angle zoom lens according to claim 1, characterized in that it satisfies the following conditions: IIl≧f, r.
１≦ｆＴなる条件を満足することを特徴とする特許請求
の範囲第２項記載の小型の広角ズームレンズ。(3) When the focal length of the lens group is fl, 1f1
A small wide-angle zoom lens according to claim 2, characterized in that it satisfies the condition: 1≦fT.
折力のレンズで構成し、前記第３レンズ群の物体側の第
ルンズ面から最終レンズ面までの厚さをｔとしたとき０
．０４≦ｔ／ｆＴ≦０．２５なる条件を満足することを
特徴とする特許請求の範囲第３項記載の小型の広角ズー
ムレンズ。(4) When the third lens group is composed of at least one lens with positive and negative refractive power, and the thickness from the object-side lens surface to the final lens surface of the third lens group is t. 0
．． 4. The compact wide-angle zoom lens according to claim 3, wherein the compact wide-angle zoom lens satisfies the condition: 04≦t/fT≦0.25.
を向けたメニスカス状の負レンズ、両レンズ面が凹面の
負レンズ、そして、物体側に凸面を向けたメニスカス状
の正レンズで構成することを特徴とする特許請求の範囲
第３項記載の小型の広角ズームレンズ。(5) The lens group consists of, in order from the object side, a meniscus-shaped negative lens with a convex surface facing the object side, a negative lens with concave surfaces on both lens surfaces, and a meniscus-shaped positive lens with a convex surface facing the object side. 4. A compact wide-angle zoom lens according to claim 3, characterized in that the lens comprises:
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57084171A JPS58200208A (en) | 1982-05-19 | 1982-05-19 | Small-sized wide-angle zoom lens |
| US06/733,856 US4647160A (en) | 1981-12-24 | 1985-05-13 | Small-sized wide angle zoom objective |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57084171A JPS58200208A (en) | 1982-05-19 | 1982-05-19 | Small-sized wide-angle zoom lens |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58200208A true JPS58200208A (en) | 1983-11-21 |
| JPS6224767B2 JPS6224767B2 (en) | 1987-05-29 |
Family
ID=13823043
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57084171A Granted JPS58200208A (en) | 1981-12-24 | 1982-05-19 | Small-sized wide-angle zoom lens |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58200208A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61167919A (en) * | 1985-01-21 | 1986-07-29 | Canon Inc | Variable power finder |
| JPS61240217A (en) * | 1985-04-17 | 1986-10-25 | Asahi Optical Co Ltd | Compact wide angle zoom lens |
| JPS61267721A (en) * | 1984-12-22 | 1986-11-27 | Canon Inc | Zoom lens |
| JPS63210907A (en) * | 1987-02-27 | 1988-09-01 | Asahi Optical Co Ltd | Compact and bright wide-angle zoom lens |
| JPH01284819A (en) * | 1988-05-12 | 1989-11-16 | Minolta Camera Co Ltd | Zoom lens |
| JPH03196013A (en) * | 1989-12-26 | 1991-08-27 | Canon Inc | Zoom lens |
| JP2009205055A (en) * | 2008-02-29 | 2009-09-10 | Fujinon Corp | Variable power optical system and imaging apparatus |
| JP2013210604A (en) * | 2012-02-28 | 2013-10-10 | Ricoh Imaging Co Ltd | Close range correction lens system |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5188243A (en) * | 1974-12-20 | 1976-08-02 | ||
| JPS5382432A (en) * | 1976-12-28 | 1978-07-20 | Canon Inc | Small zoom lens |
| JPS5459157A (en) * | 1977-10-19 | 1979-05-12 | Asahi Optical Co Ltd | Zoom lens having small distortion aberration |
| JPS5478149A (en) * | 1977-12-02 | 1979-06-22 | Asahi Optical Co Ltd | Zoom lens of small distortion aberration for wide angle |
| JPS5478148A (en) * | 1977-12-02 | 1979-06-22 | Asahi Optical Co Ltd | Zoom lens of small distortion aberration |
| JPS5532037A (en) * | 1978-08-29 | 1980-03-06 | Nippon Kogaku Kk <Nikon> | Zoom lens system for near distance |
| JPS5897016A (en) * | 1981-12-07 | 1983-06-09 | Mamiya Koki Kk | Wide angle zoom lens |
| JPS58132207A (en) * | 1982-02-01 | 1983-08-06 | Mamiya Koki Kk | Wide angle zoom lens |
-
1982
- 1982-05-19 JP JP57084171A patent/JPS58200208A/en active Granted
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5188243A (en) * | 1974-12-20 | 1976-08-02 | ||
| JPS5382432A (en) * | 1976-12-28 | 1978-07-20 | Canon Inc | Small zoom lens |
| JPS5459157A (en) * | 1977-10-19 | 1979-05-12 | Asahi Optical Co Ltd | Zoom lens having small distortion aberration |
| JPS5478149A (en) * | 1977-12-02 | 1979-06-22 | Asahi Optical Co Ltd | Zoom lens of small distortion aberration for wide angle |
| JPS5478148A (en) * | 1977-12-02 | 1979-06-22 | Asahi Optical Co Ltd | Zoom lens of small distortion aberration |
| JPS5532037A (en) * | 1978-08-29 | 1980-03-06 | Nippon Kogaku Kk <Nikon> | Zoom lens system for near distance |
| JPS5897016A (en) * | 1981-12-07 | 1983-06-09 | Mamiya Koki Kk | Wide angle zoom lens |
| JPS58132207A (en) * | 1982-02-01 | 1983-08-06 | Mamiya Koki Kk | Wide angle zoom lens |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61267721A (en) * | 1984-12-22 | 1986-11-27 | Canon Inc | Zoom lens |
| JPS61167919A (en) * | 1985-01-21 | 1986-07-29 | Canon Inc | Variable power finder |
| JPS61240217A (en) * | 1985-04-17 | 1986-10-25 | Asahi Optical Co Ltd | Compact wide angle zoom lens |
| JPH0319526B2 (en) * | 1985-04-17 | 1991-03-15 | Asahi Optical Co Ltd | |
| JPS63210907A (en) * | 1987-02-27 | 1988-09-01 | Asahi Optical Co Ltd | Compact and bright wide-angle zoom lens |
| JPH01284819A (en) * | 1988-05-12 | 1989-11-16 | Minolta Camera Co Ltd | Zoom lens |
| JPH03196013A (en) * | 1989-12-26 | 1991-08-27 | Canon Inc | Zoom lens |
| JP2009205055A (en) * | 2008-02-29 | 2009-09-10 | Fujinon Corp | Variable power optical system and imaging apparatus |
| JP2013210604A (en) * | 2012-02-28 | 2013-10-10 | Ricoh Imaging Co Ltd | Close range correction lens system |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6224767B2 (en) | 1987-05-29 |
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