JPH0248088B2 - - Google Patents
Info
- Publication number
- JPH0248088B2 JPH0248088B2 JP58097178A JP9717883A JPH0248088B2 JP H0248088 B2 JPH0248088 B2 JP H0248088B2 JP 58097178 A JP58097178 A JP 58097178A JP 9717883 A JP9717883 A JP 9717883A JP H0248088 B2 JPH0248088 B2 JP H0248088B2
- Authority
- JP
- Japan
- Prior art keywords
- lens group
- lens
- refractive power
- zoom
- 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.)
- Expired - Lifetime
Links
- 230000004075 alteration Effects 0.000 description 24
- 230000000694 effects Effects 0.000 description 6
- 206010010071 Coma Diseases 0.000 description 3
- 230000011514 reflex Effects 0.000 description 2
- 239000008186 active pharmaceutical agent Substances 0.000 description 1
- 201000009310 astigmatism Diseases 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
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
- G02B15/144—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 four groups only
- G02B15/1445—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 four groups only the first group being negative
- G02B15/144511—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 four groups only the first group being negative arranged -+-+
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Nonlinear Science (AREA)
- Lenses (AREA)
Description
本発明はズームレンズに関し、特に物体側の第
１レンズ群が負の屈折力であるTTL35ミリ一眼
レフカメラ用ズームレンズの主に標準レンズもし
くはそれより短い焦点距離から始まりズーム倍率
が２〜３クラスのズームレンズに関する。
従来、物体側より順に、負の屈折力の第１レン
ズ群、正の屈折力の第２レンズ群および負の屈折
力の第３レンズ群で構成され、それらのレンズ群
が、独立に移動してズーミングを行うズームレン
ズがBP398307、特開昭54−26754特開昭57−5023
などで提案されている。これらのタイプのズーム
レンズは負の屈折力と正の屈折力の２つのレンズ
群で構成されるズームレンズに比べ高倍率に出
来、しかもある程度コンパクトにすることが容易
となる利点がある。
しかしながら、さらにコンパクト化を進め、も
しくは広角端のズーム位置で大画角化を図つた場
合、各レンズ群の屈折力が強くなるためズーミン
グもしくはフオーカシング（第１レンズ群でフオ
ーカシングを行う場合）による諸収差の変動が大
きくなり高性能化もしくは大口径化を実現するこ
とは極めて困難とされていた。特に第１レンズ群
の屈折力が強くなると、フオーカシングとズーミ
ングによる収差変動、第２レンズ群の屈折力が強
くなるとズーミングによる収差変動が大きくなる
傾向がある。
本発明は、上記従来例の欠点である、コンパク
ト化と広角端のズーム位置での大画角化による性
能劣化を防いだ高性能のズームレンズの提供を目
的とする。
本発明のズームレンズの主たる特徴は、物体側
より順に負の屈折力の第１レンズ群、正の屈折力
の第２レンズ群、負の屈折力の第３レンズ群そし
て正の屈折力の第４レンズ群の４つのレンズ群を
有し、ズーミングに際し、第１レンズ群、第２レ
ンズ群、第３レンズ群をそれぞれ独立に移動させ
ることである。そして更に好ましくは第１レンズ
群と第２レンズ群は望遠端で最も接近し、第３レ
ンズ群は広角端で第４レンズ群に最も接近する配
置にすることである。そしてより良好なる収差補
正を達成する為には第１レンズ群から第４レンズ
群までの焦点距離と望遠端での全系の焦点距離を
それぞれf1、f2、f3、f4、fTとした時、
１＜f4／fT＜８
0.5＜｜f1｜／fT＜1.2
f2＜｜f1｜＜｜f3｜＜f4
の各条件を満たすことである。
本発明の主たる特徴はまず、ズーミング中固定
の正の屈折力の第４レンズ群が配されていること
である。この為第１レンズ群から第３レンズ群ま
では正の屈折力を持つため、その屈折力は第１レ
ンズ群から第４レンズ群（全系）の正の屈折力に
比べて弱くなつている。このことは第１レンズ群
から第３レンズ群までの屈折力を従来に対し、弱
くすることが出来、この結果高性能化がより容易
となる。また、第１レンズ群と第２レンズ群の屈
折力を従来と同じにした場合、第３レンズ群の負
の屈折力は従来より強くすることが出来、ズーミ
ングによる各レンズ群の少ない移動量でズーム倍
率をかせぐことが可能となり、よりコンパクト化
が実現出来る。この効果を最大限出すためには広
角端と望遠端での各レンズ群の配置を上記構成す
るのが好ましい。つまり、広角端から望遠端へズ
ーミングする時、第２レンズ群が物体側方向へ移
動し、この時、第３レンズ群は第２レンズ群と同
じ物体側方向へ移動させることである。この第２
レンズ群に対する第３レンズ群の移動量の比を制
御することによりコンパクト化と高性能化を両立
させることが容易となる。この移動量の比を大き
くして行くと、ズーミングによる収差変動は減る
傾向になるが、望遠端での全長（第１面からフイ
ルム面までの距離）が長くなり、さらに進めると
広角端での全長より長くなつてしまう。また、移
動量の比小さくして行くと、上記と逆の傾向とな
る。従つて望遠端の全長が広角端の全長より長く
ならない範囲（コンパクト化の限界）で高性能化
を図るのが最も好ましい。
この時、ズーム倍率を最も効率良く行つている
のは第２レンズ群であり、コンパクト化を保つに
は、第２レンズ群を効率良く移動させる必要があ
り、少なくとも望遠端において、第１レンズ群と
第２レンズ群を最も接近させておくのが好まし
い。
また、第３レンズ群および第４レンズ群はそれ
程屈折力が強くないので、広角端においてレンズ
全長の短縮およびバツクフオーカスを必要量確保
するため、第３レンズ群と第４レンズ群は広角端
で最も接近させることが好ましい。この場合第３
レンズ群と第４レンズ群はどのような動きをして
もよく、広角端で最も接近する移動軌跡を描くよ
うなものであればよい。尚、第２レンズ群を物体
側へ移動させるかわりに、像面側に移動させ、そ
れと共に第３レンズ群も像面側へ移動させても良
い。
次に、、について述べる。
条件、、は各レンズ群の屈折力を制限す
るものあり、特にTTL35ミリ一眼レフカメラ用
ズームレンズを実現する時にコンパクト化と高性
能化の双方を良好に達成する為のものである。条
件の下限値以下では第４レンズ群単純なレンズ
構成にすることが困難となり、大型化してしまい
又上限値以上では第４レンズ群の屈折力が弱く成
り過ぎ、コンパクト・高性能の効果がうすれて来
る。条件の下限値以下では、広角端より望遠端
の方が全長が長くなる傾向となり、さらに望遠端
で大口径化もしくは球面収差を良好に補正するこ
とが困難となる。上限値以上では広角端の全長の
短縮化がもの足りなくなる。また、第２レンズ群
は倍率をかせぐ働きをするため最も屈折力を強く
する必要があり、第１レンズ群は前玉径もしくは
フオーカシングによる操出量を制御するため第２
レンズ群の次に屈折力が強く、第３レンズ群は倍
率とズーミングによる収差変動、第４レンズ群は
主にズーミングによる収差変動を条去する働きの
ため屈折力は第１、第２レンズ群よりも弱くする
のが好ましい。これが条件である。
次に正の屈折力の第４レンズ群の収差論理的作
用効果について述べる。表−１は後述する本発明
の実施例１の３次収差係数である。
表１に見る如く、第４レンズ群はズーミング中
球面収差（SA）は一定であるが、一定でない収
差も多くあり、コマ収差（CM）は広角端で最も
多く外向性のコマを発生している。一般に負の屈
折力が先行するズームタイプにおいて広角端を大
画角とし、しかもコンパクトしようとすると広角
端付近の軸外光束の主光線近傍では内向性のコマ
が出やすい傾向を持つている。この為に本実施例
のズーミングでは従来多く発生しがちな内向性の
コマを打ち消すのにこの外向性のコマは非常に有
効となる。また望遠側では小さい値となつてお
り、悪影響は少ない。このように本発明の実施例
１のズームレンズにおいては第４レンズ群は、第
１〜第３レンズ群から発生する交流成分の収差
（ズーミングにより異なる量）を打ち消す作用効
果を持つている。従つて従来の３群構成のズーム
レンズ（全系で収差が除去されている）と像面の
間にいわゆるリア・アタツチメントレンズ（これ
のみで収差が除去されている）を装着したレンズ
系に対し、本発明は根本的に作用効果を異にして
いる。
また、通常は第１レンズ群を繰り出すことによ
り異なる物体距離に対しフオーカシングを行う
が、自動焦点合せ機構を備えたレンズもしくはカ
メラに対しては第３レンズ群もしくは第４レンズ
群でフオーカシングを行うことも可能である。
次に本発明の数値実施例を示す。数値実施例に
おいてRiは物体側より順に第ｉ番目のレンズ面
の曲率半径、Diは物体側より順に第ｉ番目のレ
ンズ厚及び空気間隔、Niとνiは夫々物体側より
順に第ｉ番目のレンズのガラスの屈折率とアツベ
数である。
実施例１はズーム倍率2.82で画角72.3゜〜29゜、
FNO4の仕様であり開口絞りはG6とG7の間に備
えている。
実施例２はズーム倍率1.92で画角47.6゜〜26゜、
FNO4〜4.5の仕様であり開口絞りはG7とG8の間
のR15である。
The present invention relates to zoom lenses, and in particular, zoom lenses for TTL 35 mm single-lens reflex cameras in which the first lens group on the object side has negative refractive power, and which start with a standard lens or a shorter focal length and have a zoom magnification of 2 to 3 classes. Regarding zoom lenses. Conventionally, in order from the object side, it is composed of a first lens group with negative refractive power, a second lens group with positive refractive power, and a third lens group with negative refractive power, and these lens groups move independently. The zoom lens that performs zooming is BP398307, JP-A-54-26754, JP-A-57-5023.
etc. have been proposed. These types of zoom lenses have the advantage that they can have higher magnification than zoom lenses that are composed of two lens groups, one with negative refractive power and the other with positive refractive power, and can be made more compact to some extent. However, when further downsizing or when attempting to increase the angle of view at the wide-angle end zoom position, the refractive power of each lens group becomes stronger, causing problems with zooming or focusing (when focusing is performed with the first lens group). It has been considered extremely difficult to achieve high performance or a large aperture due to large fluctuations in aberrations. In particular, when the refractive power of the first lens group becomes strong, aberration fluctuations due to focusing and zooming tend to increase, and when the refractive power of the second lens group becomes strong, aberration fluctuations due to zooming tend to increase. An object of the present invention is to provide a high-performance zoom lens that prevents performance deterioration due to compactness and a large angle of view at the wide-angle end zoom position, which are the drawbacks of the conventional example. The main features of the zoom lens of the present invention are, in order from the object side, a first lens group with negative refractive power, a second lens group with positive refractive power, a third lens group with negative refractive power, and a third lens group with positive refractive power. It has four lens groups, and during zooming, the first lens group, second lens group, and third lens group are moved independently. More preferably, the first lens group and the second lens group are closest to each other at the telephoto end, and the third lens group is closest to the fourth lens group at the wide-angle end. In order to achieve better aberration correction, the focal length from the first lens group to the fourth lens group and the focal length of the entire system at the telephoto end are f 1 , f 2 , f 3 , f 4 , f , respectively. When T , the following conditions are satisfied: 1<f 4 /f T <8 0.5<|f 1 |/f T <1.2 f 2 <|f 1 |<|f 3 |<f 4 . The main feature of the present invention is that a fourth lens group having a positive refractive power that is fixed during zooming is provided. For this reason, the first to third lens groups have positive refractive power, which is weaker than the positive refractive power of the first to fourth lens groups (the entire system). . This allows the refractive power from the first lens group to the third lens group to be made weaker than in the past, and as a result, it becomes easier to improve performance. In addition, when the refractive powers of the first and second lens groups are the same as before, the negative refractive power of the third lens group can be made stronger than before, and the amount of movement of each lens group during zooming is small. It becomes possible to increase the zoom magnification and make it more compact. In order to maximize this effect, it is preferable to configure the arrangement of each lens group at the wide-angle end and the telephoto end as described above. That is, when zooming from the wide-angle end to the telephoto end, the second lens group moves in the object side direction, and at this time, the third lens group moves in the same direction as the second lens group. This second
By controlling the ratio of the amount of movement of the third lens group to the lens group, it becomes easy to achieve both compactness and high performance. As the ratio of this amount of movement increases, aberration fluctuations due to zooming tend to decrease, but the total length at the telephoto end (distance from the first surface to the film surface) increases, and if the ratio is increased further, the aberration fluctuations due to zooming tend to decrease. It becomes longer than the total length. Furthermore, when the ratio of the amount of movement is decreased, the tendency is opposite to the above. Therefore, it is most preferable to achieve high performance within a range where the total length at the telephoto end is not longer than the total length at the wide-angle end (the limit of compactness). At this time, it is the second lens group that most efficiently controls the zoom magnification, and in order to maintain compactness, it is necessary to move the second lens group efficiently.At least at the telephoto end, the first lens group It is preferable to place the second lens group and the second lens group closest to each other. In addition, the third and fourth lens groups do not have very strong refractive power, so in order to shorten the overall lens length and secure the necessary amount of back focus at the wide-angle end, the third and fourth lens groups have the highest refractive power at the wide-angle end. It is preferable to bring them closer together. In this case the third
The lens group and the fourth lens group may move in any manner as long as they draw a movement trajectory that brings them closest at the wide-angle end. Note that instead of moving the second lens group toward the object side, it may be moved toward the image plane side, and at the same time, the third lens group may also be moved toward the image plane side. Next, we will discuss. These conditions limit the refractive power of each lens group, and are intended to achieve both compactness and high performance, especially when creating a zoom lens for a TTL 35mm single-lens reflex camera. Below the lower limit of the conditions, it will be difficult to make the fourth lens group a simple lens configuration, resulting in an increase in size, and above the upper limit, the refractive power of the fourth lens group will become too weak, reducing the compactness and high performance effect. I'm coming. Below the lower limit of the conditions, the overall length tends to be longer at the telephoto end than at the wide-angle end, and furthermore, it becomes difficult to increase the aperture or to satisfactorily correct spherical aberration at the telephoto end. If the value exceeds the upper limit, the overall length at the wide-angle end will not be shortened enough. In addition, the second lens group needs to have the strongest refractive power because it works to increase the magnification, and the first lens group has the second lens group to control the front lens diameter or the amount of focusing due to focusing.
The refractive power is the second strongest after the lens group, and the third lens group works to eliminate aberration fluctuations due to magnification and zooming, and the fourth lens group mainly works to eliminate aberration fluctuations due to zooming, so the refractive power is the same as that of the first and second lens groups. It is preferable to make it weaker than This is the condition. Next, the logical effects of aberrations of the fourth lens group having positive refractive power will be described. Table 1 shows the third-order aberration coefficients of Example 1 of the present invention, which will be described later. As shown in Table 1, the spherical aberration (SA) of the fourth lens group is constant during zooming, but there are many aberrations that are not constant, and coma aberration (CM) produces extroverted coma most often at the wide-angle end. There is. In general, in a zoom type that has negative refractive power, if you try to make the wide-angle end a large angle of view and compact, there is a tendency for inward coma to appear near the principal ray of the off-axis beam near the wide-angle end. For this reason, in the zooming of this embodiment, this extrovert frame is very effective in canceling out the introvert frame, which tends to occur conventionally. Furthermore, the value is small on the telephoto side, so there is little negative effect. As described above, in the zoom lens according to the first embodiment of the present invention, the fourth lens group has the effect of canceling out the aberration (amount that varies depending on zooming) of the AC component generated from the first to third lens groups. Therefore, a lens system with a so-called rear attachment lens (which alone eliminates aberrations) is installed between a conventional three-group zoom lens (aberrations are eliminated in the entire system) and the image plane. In contrast, the present invention has fundamentally different effects. Also, normally focusing is performed for different object distances by extending the first lens group, but for lenses or cameras equipped with an automatic focusing mechanism, focusing is performed with the third or fourth lens group. is also possible. Next, numerical examples of the present invention will be shown. In the numerical examples, Ri is the radius of curvature of the i-th lens surface from the object side, Di is the thickness and air gap of the i-th lens from the object side, and Ni and νi are the i-th lens surface from the object side, respectively. are the refractive index and Atsube number of the glass. Example 1 has a zoom magnification of 2.82 and an angle of view of 72.3° to 29°.
It has FNO4 specifications and has an aperture between G6 and G7. Example 2 has a zoom magnification of 1.92 and an angle of view of 47.6° to 26°.
The specification is FNO4~4.5, and the aperture is R15, which is between G7 and G8.
【表】【table】
【表】【table】
【表】【table】
【表】【table】
【表】
（実施例１の３次収差係数）
開口絞りは第２レンズ群内（G6とG7の中間）
に置いてある。
Ｌ：軸上色収差 SA：球面収差
Ｔ：倍率色収差 CM：コマ収差
AS：非点収差
PT：ペツツバール和
DS：歪曲収差[Table] (Third-order aberration coefficient of Example 1) Aperture stop is in the second lens group (between G6 and G7)
It is located at. L: Axial chromatic aberration SA: Spherical aberration T: Lateral chromatic aberration CM: Comatic aberration AS: Astigmatism PT: Petzval sum DS: Distortion aberration
第１図、第２図は本発明のズームレンズの数値
実施例１、２のレンズ断面図、第３図、第４図は
本発明のズームレンズの数値実施例１、２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。
Figures 1 and 2 are cross-sectional views of numerical examples 1 and 2 of the zoom lens of the present invention, and Figures 3 and 4 are diagrams of various aberrations of numerical examples 1 and 2 of the zoom lens of the present invention. be. In the figure, ΔM is a meridional image plane, and ΔS is a sagittal image plane.
Claims (1)
正の屈折力の第２レンズ群、負の屈折力の第３レ
ンズ群そして正の屈折力の第４レンズ群の４つの
レンズ群を有し、ズーミングに際し、前記第１レ
ンズ群と第２レンズ群は望遠端で最も接近し、第
３レンズ群は広角端で第４レンズ群に最も接近す
るように前記第１レンズ群、第２レンズ群、及び
第３レンズ群がそれぞれ同時に独立に移動し、
又、開口絞りを前記第２レンズ群内に配置し、前
記第１、第２、第３、第４レンズ群の焦点距離を
それぞれf1、f2、f3、f4とし望遠端における全系
の焦点距離をfTとしたとき、 １＜f4／fT＜８ 0.5＜｜f1｜／fT＜1.2 f2＜｜f1｜＜｜f3｜＜f4 なる条件を満足することを特徴とするズームレン
ズ。[Claims] 1. A first lens group having negative refractive power in order from the object side,
It has four lens groups: a second lens group with positive refractive power, a third lens group with negative refractive power, and a fourth lens group with positive refractive power, and when zooming, the first lens group and the second lens group The first lens group, the second lens group, and the third lens group each move simultaneously and independently so that the groups are closest to each other at the telephoto end, and the third lens group is closest to the fourth lens group at the wide-angle end. ,
Further, an aperture stop is arranged in the second lens group, and the focal lengths of the first, second, third, and fourth lens groups are f1, f2, f3, and f4, respectively, and the focal length of the entire system at the telephoto end. A zoom lens that satisfies the following conditions, where fT is 1<f4/fT<8 0.5<|f1|/fT<1.2 f2<|f1|<|f3|<f4.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58097178A JPS59222806A (en) | 1983-06-01 | 1983-06-01 | Zoom lens |
| US06/903,901 US4687302A (en) | 1983-06-01 | 1986-09-04 | Zoom lens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58097178A JPS59222806A (en) | 1983-06-01 | 1983-06-01 | Zoom lens |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59222806A JPS59222806A (en) | 1984-12-14 |
| JPH0248088B2 true JPH0248088B2 (en) | 1990-10-24 |
Family
ID=14185326
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58097178A Granted JPS59222806A (en) | 1983-06-01 | 1983-06-01 | Zoom lens |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59222806A (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4828372A (en) * | 1987-10-09 | 1989-05-09 | Eastman Kodak Company | Wide-angle zoom lens |
| US4818082A (en) * | 1988-05-27 | 1989-04-04 | Eastman Kodak Company | Compact wide-angle close-focus SLR zoom lens |
| JP2722709B2 (en) * | 1989-09-05 | 1998-03-09 | キヤノン株式会社 | Zoom lens |
| JP5653165B2 (en) * | 2009-12-22 | 2015-01-14 | キヤノン株式会社 | Zoom lens |
| EP2657745B1 (en) * | 2010-12-22 | 2020-02-19 | Panasonic Corporation | Zoom lens system, interchangeable lens device, and camera system |
| JP5975773B2 (en) * | 2012-07-30 | 2016-08-23 | キヤノン株式会社 | Zoom lens and imaging apparatus having the same |
| JP6354222B2 (en) * | 2014-03-12 | 2018-07-11 | 株式会社ニコン | Zoom lens, optical device |
| JP7187400B2 (en) * | 2019-07-29 | 2022-12-12 | キヤノン株式会社 | Optical system and imaging device |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS492312A (en) * | 1972-04-24 | 1974-01-10 | ||
| JPS5334539A (en) * | 1976-09-13 | 1978-03-31 | Tokina Optical | Wide angle high zoom ratio zoom system |
-
1983
- 1983-06-01 JP JP58097178A patent/JPS59222806A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS492312A (en) * | 1972-04-24 | 1974-01-10 | ||
| JPS5334539A (en) * | 1976-09-13 | 1978-03-31 | Tokina Optical | Wide angle high zoom ratio zoom system |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59222806A (en) | 1984-12-14 |
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