JPS6363881B2 - - Google Patents
Info
- Publication number
- JPS6363881B2 JPS6363881B2 JP455079A JP455079A JPS6363881B2 JP S6363881 B2 JPS6363881 B2 JP S6363881B2 JP 455079 A JP455079 A JP 455079A JP 455079 A JP455079 A JP 455079A JP S6363881 B2 JPS6363881 B2 JP S6363881B2
- Authority
- JP
- Japan
- Prior art keywords
- lens
- condition
- becomes
- under
- aberration
- 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
Links
- 230000005499 meniscus Effects 0.000 claims description 5
- 230000004075 alteration Effects 0.000 description 25
- 201000009310 astigmatism Diseases 0.000 description 9
- 206010010071 Coma Diseases 0.000 description 5
- 230000007423 decrease Effects 0.000 description 4
- 230000004907 flux Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 239000002131 composite material Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
Landscapes
- Lenses (AREA)
Description
本発明は4群4枚構成で全長が0.6f程度と短か
くコンパクトな写真レンズに関するものであり、
例えば110フイルムを使用するカメラのような小
型カメラレンズに関するものである。
衆知のごとく110フイルム使用カメラは本体そ
のものが小型、軽量、且つ安価であるため、それ
に使用されるレンズも小型、軽量、且つ安価であ
ることが要求されている。
従来、最も一般的な110フイルム使用カメラで
はそのレンズがF5.6からF11程度のものであり、
ASA400程度の高感度フイルムを使用し、ストロ
ボ無しで撮影できるためにはF2程度の明るいレ
ンズが必要とされる。
F2程度の明るいレンズに関するレンズは例え
ば、特開昭50−26534のごとく4群5枚構成と複
雑であり、又、4群4枚構成で明るいレンズで
も、特開昭49−53036のように使用画角が半画角
16.5゜と狭く、あるいは特公昭50−30454のごとく
全長が0.76fと長いものであつた。
本発明は上述のごとき現状に鑑み、改良と工夫
を重ねた結果、4群4枚の簡単な構成で、且つ、
全長が0.6f程度のコンパクトであり、更にF2前後
と明るいレンズでありながら、35mmサイズのいわ
ゆる標準レンズに相当する半画角23゜の画角を有
し、収差の良好に補正されたレンズの提供をする
ことにある。
以下に本発明を図示の実施例により詳細に説明
することにする。本発明のレンズ構成は
第1図において物界側より順に、第1レンズは
凸面を物界側に向けた正メニスカスレンズ、第2
レンズは両凹レンズ、第3レンズは正レンズ、第
4レンズは凸面を物界側に向けた正メニスカスレ
ンズの4群4枚構成にして
0.65f<f1<0.80f …(1)
n1、n3、n4>1.75 …(2)
0.46<r1<0.54f …(3)
0.83f<|r3|<1.1f、r3<0 …(4)
0.56f<r7<0.66f …(5)
1.0<r8/r7<1.5 …(6)
ただし、
f;レンズ系全系の合成焦点距離
f1;第1レンズの焦点距離
ri;第i番目の面の曲率半径
ni;第i番目レンズのd線に対する屈折率
なる条件を同時に満足することを特徴とする大口
径比レンズである。
本発明のごとく4群4枚という簡単な構成で、
全長0.6f前後のコンパクトさを阻うためには全系
中の止レンズのパワーを強くすることが必要であ
るが、その結果として著るしくアンダーな球面収
差、コマ収差、非点収差が発生し、F2という大
口径比化が困難になる。
本発明の意義は4群4枚という単純な構成でこ
れらの諸問題を解決し、全長が0.6f程度のコンパ
クトな大口径比レンズを可能ならしめたところに
ある。
以下、本発明の意図を達成せしめ得た上記各条
件の技術的意義を詳述することとする。
先ず条件(1)はコンパクトにして、且つ、大口径
比レンズを達成するための条件で、条件(1)の下限
を越えてf1が短かくなると第1レンズにより光束
が急激に集光させられるためコンパクト化には有
利であるが、第1レンズの面が強くなるために高
次的にアンダーな球面収差が発生し、全系として
の球面収差のバランスが崩れてしまう。
逆に上限を越えてf1が大きくなると高次的にア
ンダーな球面収差の発生は小さくなるが、第1レ
ンズの集光力が弱まるため本発明が意図とする全
長0.6f程度のコンパクトさが達成できなくなる。
条件(2)は条件(1)の下でペツツバール和の減少を
図ると共に、凸レンズの面をゆるくし、実用焦点
距離の際に極端に小さな曲率半径となることを避
けるための条件である。
条件(2)を下まわつて屈折率が小さくなると、各
凸レンズ面が強くなり高次的にアンダーな収差が
発生し、且つ、ペツツバール和が大となるため像
面が急激にアンダーになり最終像面を良好に保ち
得なくなる。
大口径比化による球面収差を良好に保つために
は条件(2)の下で第1レンズの曲率半径を条件(3)の
範囲内にゆるく押え、高次的にアンダーな球面収
差の発生を押える必要がある。
条件(3)の上限を越えてr1がゆるくなると球面収
差が補正過剰となり、逆に下限を越えてr1が強く
なると急激に高次的にアンダーな球面収差が発生
し条件(4)の下では補正しきれない。
条件(4)は、条件(1)、(3)の下で第1レンズで発生
するアンダーな球面収差とコマ収差とのフレヤー
を補正するため条件のである。
条件(4)の上限を越えてr3がゆるくなるとr3で生
じる上方光束に対するオーバー成分の発生が少な
くなり補正不足となる。
逆に下限を越えてr3が強くなると高次的にオー
バーな球面収差とコマフレヤーが発生し補正過剰
となる。
更に下記の0.48f<r4<0.56fなる条件を附加す
ると下方光束のコマフレヤーの補正に有効であ
る。
上限をこえてr4がゆるくなるとr4で発生する下
方光束に対するアンダーな成分の発生が少なくな
り補正不足の状態になり、逆に下限を越えてr4が
強くなると補正過剰になる。
条件(5)は非点収差の補正に関する条件である。
第4レンズのr7面に対して軸外光束は入射角に応
じて、光軸より高い位置に入射するため、非点収
差に与える影響が大きく、条件(2)の下で非点収差
を良好に補正するためにはr7が条件(5)を満たす必
要がある。条件(5)の上限を越えてr7がゆるくなる
とメリジオナル像面が著るしく高次的にオーバー
になり非点収差を良好に補正し得なくなり、r7が
条件(5)の下限を越えて強くなると、逆にメリジオ
ナル像面が著るしく高次的にアンダーとなり、同
様に非点収差を良好に補正し得ない。
更に、条件(5)の下で0.1f<d3+d4<0.2fに保て
ば非点収差の補正が一層容易になる。この条件の
上限を越えて(d3+d4)が大きくなるとオーバー
な非点収差が発生し補正過剰となり、逆に下限を
越えて小さくなるとアンダーな非点収差が発生し
補正不足となる。
条件(6)は歪曲収差の補正に関する条件で、r8/
r7が条件(6)の上限を越えて大きくなると歪曲収差
が補正不足となり、条件(6)の下限を越えて小さく
なると逆に補正過剰となる。
又、良好な画質を保証するためには色収差の補
正条件として、各正レンズのアツベ数ν1、ν3、ν4
負レンズのアツベ数ν2を各々ν1、ν3、ν4>40 ν2<
30にしておくことが望ましい。
この条件を満たさない場合にはアンダーな色収
差が発生し、全画面にわたつて良好な色収差のバ
ランスを保つことが不可能となり、良好な画質を
保証し得ない。
以下、本発明に基づいた具体的実施例を示す。
但し、何れもf=1.0に置換した値にして、
ri;物界側より順にみた第i番目の面の曲率半径
di;物界側より順にみた第i番目の軸上厚み、又
は空気間隔
ni;物界側より順にみた第i番目のレンズのd線
に対する屈折率
νi;物界側より順にみた第i番目のレンズのアツ
ベ数
f;レンズ系全系の合成焦点距離
f1;第1番目のレンズの単体焦点距離
Σd;第1面から最終面までのレンズ全長
The present invention relates to a short and compact photographic lens with a configuration of 4 elements in 4 groups and a total length of about 0.6 f.
For example, it relates to small camera lenses such as cameras that use 110 film. As is well known, cameras using 110 film are compact, lightweight, and inexpensive, so the lenses used therein are also required to be small, lightweight, and inexpensive. Traditionally, the most common 110 film cameras have lenses of F5.6 to F11.
In order to use high-sensitivity film of about ASA400 and to be able to shoot without flash, a lens as fast as F2 is required. Lenses related to lenses as fast as F2 are complex, with a composition of 5 elements in 4 groups, such as JP-A No. 50-26534, and even lenses that are fast and have a composition of 4 elements in 4 groups are used, such as in JP-A No. 49-53036. Angle of view is half angle of view
It was as narrow as 16.5°, or as long as 0.76f, as in the case of Special Publication No. 50-30454. In view of the above-mentioned current situation, the present invention is the result of repeated improvements and ingenuity, and has a simple configuration of 4 elements in 4 groups, and
Although it is a compact lens with a total length of about 0.6 f and is bright at around F2, it has a half-angle of view of 23 degrees, equivalent to a 35 mm size so-called standard lens, and has well-corrected aberrations. It is about providing. The invention will be explained in more detail below by means of illustrated embodiments. The lens configuration of the present invention is, in order from the object world side in Fig. 1, the first lens is a positive meniscus lens with its convex surface facing the object world side, the second lens
The lens is composed of 4 elements in 4 groups: a biconcave lens, the third lens is a positive lens, and the fourth lens is a positive meniscus lens with its convex surface facing the object world.0.65f<f 1 <0.80f...(1) n 1 , n 3 , n 4 >1.75 …(2) 0.46<r 1 <0.54f …(3) 0.83f<|r 3 |<1.1f, r 3 <0 …(4) 0.56f<r 7 <0.66f … (5) 1.0< r8 / r7 <1.5...(6) However, f; composite focal length of the entire lens system f1 ; focal length of the first lens r i ; radius of curvature of the i-th surface n i ; It is a large aperture ratio lens characterized in that it simultaneously satisfies the conditions of the refractive index for the d-line of the i-th lens. With a simple configuration of 4 elements in 4 groups as in the present invention,
In order to keep the lens compact with a total length of around 0.6f, it is necessary to increase the power of the stop lens in the entire system, but this results in significantly under-spherical aberration, coma aberration, and astigmatism. However, increasing the aperture ratio to F2 becomes difficult. The significance of the present invention is that it solves these problems with a simple configuration of 4 elements in 4 groups, making it possible to create a compact large aperture ratio lens with an overall length of about 0.6 f. Hereinafter, the technical significance of each of the above conditions that enabled the purpose of the present invention to be achieved will be explained in detail. First of all, condition (1) is a condition for making the lens compact and achieving a large aperture ratio.If f1 becomes short beyond the lower limit of condition (1), the light flux will be rapidly focused by the first lens. However, since the surface of the first lens becomes strong, under-spherical aberration occurs in a higher order, and the balance of spherical aberration as a whole system is lost. Conversely, if f 1 increases beyond the upper limit, the occurrence of high-order under-spherical aberration will be reduced, but the light-gathering power of the first lens will be weakened, making it impossible to achieve the compactness of the overall length of about 0.6 f as intended by the present invention. become unattainable. Condition (2) is a condition for reducing the Petzval sum under condition (1), making the surface of the convex lens loose, and avoiding an extremely small radius of curvature at a practical focal length. When the refractive index becomes smaller by falling below condition (2), each convex lens surface becomes stronger and higher-order under-aberration occurs, and the Petzval sum becomes large, so the image plane suddenly becomes under-represented and the final image becomes It becomes impossible to maintain a good surface. In order to maintain good spherical aberration due to the large aperture ratio, under condition (2), the radius of curvature of the first lens should be kept loosely within the range of condition (3) to prevent the occurrence of higher-order under-spherical aberration. I need to hold it down. If r 1 becomes loose beyond the upper limit of condition (3), spherical aberration will be overcorrected, and conversely, if r 1 becomes strong beyond the lower limit, under-spherical aberration will suddenly occur in higher order, resulting in condition (4). It cannot be corrected below. Condition (4) is a condition for correcting flare caused by under-spherical aberration and coma aberration that occurs in the first lens under conditions (1) and (3). If r 3 becomes loose beyond the upper limit of condition (4), the occurrence of an overcomponent for the upward luminous flux generated at r 3 will decrease, resulting in insufficient correction. On the other hand, if r 3 becomes strong beyond the lower limit, excessive high-order spherical aberration and coma flare will occur, resulting in overcorrection. Furthermore, adding the following condition 0.48f<r 4 <0.56f is effective for correcting coma flare in the downward luminous flux. When the upper limit is exceeded and r 4 becomes loose, the occurrence of under-components for the downward luminous flux generated by r 4 decreases, resulting in under-correction, and conversely, when the lower limit is exceeded and r 4 becomes strong, over-correction occurs. Condition (5) is a condition regarding correction of astigmatism.
Since the off-axis beam enters the r7 surface of the fourth lens at a position higher than the optical axis depending on the incident angle, it has a large effect on astigmatism, and under condition (2), astigmatism can be reduced. In order to make a good correction, r 7 needs to satisfy condition (5). If r 7 becomes looser than the upper limit of condition (5), the meridional image plane becomes significantly higher order and it becomes impossible to correct astigmatism well, and r 7 exceeds the lower limit of condition (5). On the other hand, if the aberration becomes strong, the meridional image surface will be significantly underdeveloped in higher order, and similarly, astigmatism cannot be corrected satisfactorily. Furthermore, if 0.1f<d 3 +d 4 <0.2f is maintained under condition (5), astigmatism can be corrected even more easily. If (d 3 +d 4 ) increases beyond the upper limit of this condition, excessive astigmatism will occur, resulting in overcorrection, and conversely, if it decreases beyond the lower limit, under astigmatism will occur, resulting in insufficient correction. Condition (6) is a condition regarding correction of distortion aberration, and r 8 /
When r 7 increases beyond the upper limit of condition (6), distortion becomes under-corrected, whereas when r 7 decreases beyond the lower limit of condition (6), it becomes over-corrected. In addition, in order to guarantee good image quality, the Atsube numbers ν 1 , ν 3 , ν 4 of each positive lens must be adjusted as chromatic aberration correction conditions.
Let the Atsube number ν 2 of the negative lens be ν 1 , ν 3 , ν 4 >40 ν 2 <
It is recommended to set it to 30. If this condition is not met, under-chromatic aberration occurs, making it impossible to maintain a good balance of chromatic aberration over the entire screen, and good image quality cannot be guaranteed. Hereinafter, specific examples based on the present invention will be shown.
However, all values are replaced with f = 1.0, r i ; radius of curvature of the i-th surface viewed from the material world side d i ; i-th axial thickness seen from the material world side, or air Spacing n i ; Refractive index for the d-line of the i-th lens viewed from the object world side ν i ; Atsube number f of the i-th lens viewed from the object world side; Composite focal length of the entire lens system f 1 ; Single focal length of the first lens Σd; Total length of the lens from the first surface to the final surface
【表】【table】
【表】【table】
【表】【table】
【表】
以上の各実施例、及び各実施例に対応する第2
図から第4図の収差図曲線によつても明らかなよ
うに、本発明によれば、4群4枚という簡単な構
成にして、且つ、全長が0.6f前後とコンパクトで
更に、F2程度という明るいレンズでありながら
35mm版のいわゆる標準画角に相当する画角を有
し、収差の良好に補正されたレンズ系を得ること
ができ、本発明のレンズ構成及び収差補正手段が
有効であることを示している。[Table] Each of the above examples and the second example corresponding to each example
As is clear from the aberration diagram curve in FIG. 4, the present invention has a simple configuration of 4 elements in 4 groups, is compact with an overall length of around 0.6f, and has an aperture of about F2. Although it is a bright lens
A lens system having an angle of view corresponding to the so-called standard angle of view of a 35 mm version and with well corrected aberrations can be obtained, indicating that the lens configuration and aberration correction means of the present invention are effective.
第1図は本発明によるレンズの構成図で、レン
ズを前置絞りで使用する場合とビトウイン絞りで
使用する場合の両方を示してある。第2,3,
4,5図は、各々実施例1、2、3、4に対応す
る収差図を示す。第2,3,4,5図にそれぞれ
示す球面収差及びメリジオナルコマ収差の収差曲
線はd線に関しては実線、g線に関しては点線を
もつて示す。
ri;物界側より順にみた第i番目の面の曲率半
径、di;物界側より順にみた第i番目の軸上厚
み、又は空気間隔。
FIG. 1 is a structural diagram of a lens according to the invention, showing both the case where the lens is used with a front diaphragm and the case where it is used with a between diaphragm. 2nd, 3rd,
4 and 5 show aberration diagrams corresponding to Examples 1, 2, 3, and 4, respectively. The aberration curves of spherical aberration and meridional coma aberration shown in FIGS. 2, 3, 4, and 5, respectively, are shown with a solid line for the d-line and a dotted line for the g-line. r i ; radius of curvature of the i-th surface viewed from the physical world side, d i ; i-th axial thickness or air gap viewed from the physical world side.
Claims (1)
界側に向けた正メニスカスレンズ、第2レンズは
両凹レンズ、第3レンズは正レンズ、第4レンズ
は凸面を物界側に向けた正メニスカスレンズの4
群4枚構成にして 0.65f<f1<0.80f …(1) n1、n3、n4>1.75 …(2) 0.46f<r1<0.54f …(3) 0.83f<|r3|<1.1f、r3<0 …(4) 0.56f<r7<0.66f …(5) 1.0<r8/r7<1.5 …(6) ただし、 f;レンズ系全系の合成焦点距離 f1;第1レンズの焦点距離 ri;第i番目の面の曲率半径 ni;第i番目のレンズのd線に対する屈折率 なる条件を同時に満足することを特徴とする大口
径比レンズ。[Claims] 1. Viewed in order from the object world side, the first lens is a positive meniscus lens with its convex surface facing the object world side, the second lens is a biconcave lens, the third lens is a positive lens, and the fourth lens is a positive meniscus lens with its convex surface facing the object world side. 4 of a positive meniscus lens facing the physical world
With a group of 4 elements, 0.65f<f 1 <0.80f …(1) n 1 , n 3 , n 4 >1.75 …(2) 0.46f<r 1 <0.54f …(3) 0.83f<|r 3 |<1.1f, r 3 <0...(4) 0.56f< r7 <0.66f...(5) 1.0< r8 / r7 <1.5...(6) Where, f: Combined focal length of the entire lens system A large aperture ratio lens that simultaneously satisfies the following conditions: f 1 ; focal length ri of the first lens; radius of curvature ni of the i-th surface; and refractive index for the d-line of the i-th lens.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP455079A JPS5596915A (en) | 1979-01-18 | 1979-01-18 | Compact large aperture ratio lens |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP455079A JPS5596915A (en) | 1979-01-18 | 1979-01-18 | Compact large aperture ratio lens |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS5596915A JPS5596915A (en) | 1980-07-23 |
JPS6363881B2 true JPS6363881B2 (en) | 1988-12-08 |
Family
ID=11587151
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP455079A Granted JPS5596915A (en) | 1979-01-18 | 1979-01-18 | Compact large aperture ratio lens |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5596915A (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6140616A (en) * | 1984-07-31 | 1986-02-26 | Fanuc Ltd | Position control system |
JP2706946B2 (en) * | 1988-06-07 | 1998-01-28 | 旭光学工業株式会社 | Front aperture projection lens |
JP2582144B2 (en) * | 1988-11-18 | 1997-02-19 | オリンパス光学工業株式会社 | Shooting lens |
US7206143B2 (en) | 2003-05-13 | 2007-04-17 | Olympus Corporation | Image-formation optical system, and imaging system incorporating the same |
-
1979
- 1979-01-18 JP JP455079A patent/JPS5596915A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS5596915A (en) | 1980-07-23 |
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