JPH0638132B2 - Projection lens - Google Patents
Projection lensInfo
- Publication number
- JPH0638132B2 JPH0638132B2 JP59130635A JP13063584A JPH0638132B2 JP H0638132 B2 JPH0638132 B2 JP H0638132B2 JP 59130635 A JP59130635 A JP 59130635A JP 13063584 A JP13063584 A JP 13063584A JP H0638132 B2 JPH0638132 B2 JP H0638132B2
- Authority
- JP
- Japan
- Prior art keywords
- lens
- aberration
- curvature
- image
- screen
- 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
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Description
【発明の詳細な説明】 本発明は投影用レンズに関し、特に電子映像管に映出さ
れた画像をスクリーン上に拡大投影するために好適で、
大画面の実現し得る様な拡大投影用レンズに関する。The present invention relates to a projection lens, and is particularly suitable for magnifying and projecting an image displayed on an electronic picture tube on a screen,
The present invention relates to a magnifying projection lens that can realize a large screen.
一般に映像表示用投影レンズではカラー映像表示用とし
て赤、青、緑の３色の単色陰極線管を用い各々の画像を
投影レンズによりスクリーン上に投影するのであるが３
色の発色特性ともスペクトル巾が比較的狭い為色消しレ
ンズである必要はない。Generally, a projection lens for image display uses a single-color cathode ray tube of three colors of red, blue, and green for displaying a color image, and each image is projected on the screen by the projection lens.
It is not necessary to use an achromatic lens because the spectrum width is relatively narrow in both the color development characteristics.
投影レンズとして望まれる条件として大口径及び広画角
化が挙げられる。大口径化により明るい画像を得る事が
可能となり、又広画角化により短い投影距離で所望の投
影像を得る事が出来、装置全体の小型化が図れるもので
ある。Conditions desired as a projection lens include a large aperture and a wide angle of view. A bright image can be obtained by increasing the aperture, and a desired projection image can be obtained by a short projection distance by increasing the angle of view, and the overall size of the device can be reduced.
従来投影レンズとしては球面のみによる球面レンズや非
球面を含んだ非球面レンズが知られているが、球面レン
ズでは構成枚数を減らし高性能化を図る事は極めて困難
で近年は非球面を導入した非球面レンズが主流を占めて
いる。Conventionally, as a projection lens, a spherical lens with only a spherical surface or an aspherical lens including an aspherical surface is known, but it is extremely difficult to reduce the number of constituent elements to achieve high performance with a spherical lens, and in recent years an aspherical surface has been introduced. Aspherical lenses are the mainstream.
しかしながら非球面を使用して収差補正をした投影レン
ズ自体の歴史は古く、英国特許第５９３５１４が知られ
ている。この特許に開示された投影レンズは像面側より
順に両凸レンズと両凹レンズの貼り合わせレンズで第１
面に非球面をもち主として開口に依存する収差と軸上の
色収差を補正する第１群、スクリーン側に凸面を向けた
２枚の平凸レンズより構成された正の第２群、像面平坦
化手段の為の負の屈折力を有する第３群より構成されて
いる。この構成によると球面収差、像面彎曲、コマ収差
の各収差の内、第１群レンズにより球面収差、コマ収
差、又第３群により像面彎曲、歪曲収差を補正している
が第１群により補正している球面収差、コマ収差の補正
は不充分で特にコマ収差の補正が悪いものとなつてい
る。この為フレアーとして結像性能に障害を及ぼす結果
となり半画角25°以上の広画角な投影レンズを提供する
事を難しくしている。However, the projection lens itself, which has been corrected for aberrations using an aspherical surface, has a long history, and British Patent No. 593514 is known. The projection lens disclosed in this patent is a cemented lens of a biconvex lens and a biconcave lens in order from the image side.
A first group that has an aspherical surface and mainly corrects aberrations that depend on the aperture and axial chromatic aberration, a positive second group composed of two plano-convex lenses with convex surfaces facing the screen side, and image plane flattening It is composed of a third group having a negative refractive power for the means. According to this configuration, of the spherical aberration, the field curvature, and the coma aberration, the first group lens corrects the spherical aberration and the coma aberration, and the third group corrects the field curvature and the distortion aberration. Therefore, the correction of spherical aberration and coma aberration is insufficient, and the correction of coma in particular is poor. As a result, it causes flare to impair the imaging performance, making it difficult to provide a wide-angle projection lens with a half angle of view of 25 ° or more.
本発明の目的は広画角の投影レンズを実現することにあ
り、その際画質を左右するコマ収差を良好に補正するこ
とにある。そして後述の記載から明らかになる様に第３
レンズとして配したメニスカスレンズの作用によりコマ
収差の補正を達成する。An object of the present invention is to realize a projection lens with a wide angle of view, and to correct the coma aberration which influences the image quality at that time. And as will become clear from the description below, the third
Correction of coma is achieved by the action of the meniscus lens arranged as a lens.
第１図に示す本発明に係る投影レンズは、スリーン側か
ら順に、正の屈折力を有する第１レンズL1、スクリーン
側の面に比し曲率が大で且つ凸なる面を画像側へ向けた
正屈折力を有する第２レンズL2、画像側へ凹面を向けた
コンセントリツク又はコンセントリツクに近い形状のメ
ニスカス第３レンズL3、画像側の面に比し曲率が大で且
つ凹なる面をスクリーン側へ向けた第４レンズL4から構
成し、更に第２レンズと第３レンズの合成屈折力は第１
レンズの屈折力より大であり、第１レンズに少なくとも
１面の非球面を設け、第２、第３、第４レンズ中に１面
以上の非球面を設けてなる。The projection lens according to the present invention shown in FIG. 1 has, in order from the screen side, a first lens L 1 having a positive refractive power, and a surface having a large curvature and a convex surface as compared with the surface on the screen side is directed to the image side. A second lens L 2 having a positive refractive power, a concentric third lens L 3 having a concave surface facing the image side or a shape close to the concentric surface, a surface having a large curvature and a concave surface as compared with the image side surface Is composed of a fourth lens L 4 directed toward the screen side, and the combined refractive power of the second lens and the third lens is the first
The refractive power of the lens is greater than that of the first lens. At least one aspherical surface is provided on the first lens, and one or more aspherical surfaces are provided on the second, third, and fourth lenses.
続いて上述した構成に因る作用を述べる。Next, the operation resulting from the above configuration will be described.
第１レンズは、主として口径に依存する収差を補正する
為に１面以上の非球面に有し、第２レンズは主として結
像の為の正の屈折力を有し、第３レンズは映像管側に凹
面に向けたメニスカスレンズで弱い正の屈折力を有し軸
上光束への収差の発生を極力抑える為コンセントリツク
又はコンセントリツクに近い形状とし画角に依存する収
差、軸外光束収差の補正、特にコマ収差の良好な補正を
行つており、第４レンズはスクリーン側に向けた曲率大
なる凹面により画角依存収差、特に像面彎曲、歪曲収差
の補正を果している。更にこれら軸外収差の補正を良好
なものとし半画角25°以上の広画角化を実現する為第
２，第３，第４レンズの中に少なくとも一面以上の非球
面を有し高性能化を図るものである。The first lens has one or more aspherical surfaces mainly for correcting the aberration depending on the aperture, the second lens has a positive refracting power mainly for image formation, and the third lens has a picture tube. A meniscus lens with a concave surface on the side has a weak positive refractive power and has a concentric or near concentric shape to minimize the occurrence of aberrations on the axial light flux. Correction, especially coma aberration, is performed favorably, and the fourth lens corrects angle-of-view-dependent aberration, particularly field curvature and distortion, by the concave surface having a large curvature toward the screen side. Furthermore, in order to correct these off-axis aberrations and realize a wide angle of view of a half angle of view of 25 ° or more, at least one or more aspherical surfaces are included in the second, third, and fourth lenses to achieve high performance. It is intended to
すなわち球面収差、コマ収差、像面彎曲、歪曲収差の
内、第１レンズにより球面収差、コマ収差、第３レンズ
によりコマ収差、第４レンズにより像面彎曲、歪曲収差
を補正しており、特に第３レンズとして配したメニスカ
ス形状のレンズによりコマ収差を良好に補正しかつコン
セントリツク又はコンセントリツクに近い形状とする事
により軸上収差の発生を極力抑え、非常に高性能化を実
現している。That is, among spherical aberration, coma aberration, field curvature, and distortion aberration, the first lens corrects spherical aberration, coma aberration, the third lens corrects coma aberration, and the fourth lens corrects image field curvature and distortion aberration. The meniscus-shaped lens arranged as the third lens satisfactorily corrects coma aberration and makes it a concentric shape or a shape close to the concentric shape, thereby suppressing the occurrence of axial aberration as much as possible and achieving extremely high performance. .
これにより従来、性能の劣化の大きな要因であるコマ収
差のみならず球面収差、像面彎曲、歪曲収差をも良好に
補正しＦ1.2以上で半画角25°以上の大口径、広画角化
を図つた高性能な投影レンズを提供するものである。As a result, not only coma aberration, which is a major cause of performance deterioration, but also spherical aberration, field curvature, and distortion aberration have been corrected well, and a large aperture with a half angle of view of 25 ° or more and a wide angle of view of F1.2 or more. It is intended to provide a high-performance projection lens which is designed to be improved.
更に又、本願発明においては次の事項を考慮することで
高度に収差を補正するとともに設計時間の短縮を図れる
ものである。Furthermore, in the present invention, it is possible to highly correct aberrations and shorten the design time by considering the following matters.
まず、全系の屈折力をφ、第２レンズと第３レンズの合
成屈折力をφ2,3、第１レンズと第２レンズの面間隔をD
2、第３レンズのスクリーン側の面の曲率半径をR5、第
３レンズの映像管側の面の曲率半径をR6とするとき、本
発明に係る投影レンズは更に以下の条件を満足する。First, the refractive power of the entire system is φ, the combined refractive power of the second lens and the third lens is φ 2,3 , and the surface distance between the first lens and the second lens is D.
2. When the radius of curvature of the screen side surface of the third lens is R 5 and the radius of curvature of the image tube side surface of the third lens is R 6 , the projection lens according to the present invention further satisfies the following conditions. .
(1)0.75＜φ2,3／φ＜0.95 (2)0.4f＜D2＜0.6f (3)0.45＜R5／R6＜0.85 次に各条件の極値の意味を説明する。(1) 0.75 <φ 2,3 / φ <0.95 (2) 0.4f <D 2 <0.6f (3) 0.45 <R 5 / R 6 <0.85 Next, the meaning of the extreme value under each condition will be described.
条件(1)は第２レンズと第３レンズの合成のパワーに関
するもので、下限を越える時第１レンズによるパワーの
分担が大となり球面収差の補正が困難となる。上限を越
える時第２レンズと第３レンズ、主に第２レンズによる
軸外収差の発生が大となり補正を困難なものとしてく
る。これは例えば第２，第３レンズの正のパワーが増す
と、像面彎曲補正の為に第４レンズの負のパワーを増大
させなければならずこれにより歪曲収差等の収差の発生
を大きなものとし高性能化を困難なものとしてくる。The condition (1) relates to the composite power of the second lens and the third lens, and when the value goes below the lower limit, the power is largely shared by the first lens and it becomes difficult to correct spherical aberration. When the upper limit is exceeded, off-axis aberrations are largely generated by the second lens and the third lens, mainly the second lens, which makes correction difficult. This is because, for example, when the positive power of the second and third lenses increases, the negative power of the fourth lens must be increased in order to correct the field curvature, which causes a large amount of aberration such as distortion. It becomes difficult to improve the performance.
条件(2)は第１レンズと第２レンズとの間隔に関するも
ので、下限を越える時、軸外光束の結像力が不足し、第
２，第３，第４レンズの軸外光束の結像の負担量が増大
する為広画角化の大きな障害となる。上限を越える時、
軸外光束の第２レンズの後面すなわち映像管側への入射
角が大となり、軸外光束の収差の発生量が大となる。The condition (2) relates to the distance between the first lens and the second lens. When the lower limit is exceeded, the image forming power of the off-axis light beam is insufficient, and the off-axis light beams of the second, third, and fourth lenses are combined. This increases the burden on the image, which is a major obstacle to widening the angle of view. When the upper limit is exceeded,
The angle of incidence of the off-axis light beam on the rear surface of the second lens, that is, on the image tube side is large, and the amount of aberration of the off-axis light beam is large.
条件(3)は第３レンズの前面と後面の曲率半径のパワー
の分担比及びメニスカス度に関するもので下限を越える
と第３レンズのパワーが大きくなり軸上及び軸外光束の
収差の発生量が増し主なる目的であるコマ収差の補正が
困難となつてしまう。上限を越えると第３レンズのパワ
ーは非常に弱いものとなり第２レンズのパワーの負担が
増大し第２レンズによる収差の発生量が増し収差補正が
困難なものとなる。The condition (3) relates to the power distribution ratio of the curvature radius of the front surface and the rear surface of the third lens and the meniscus degree. When the lower limit is exceeded, the power of the third lens increases and the amount of aberration of the on-axis and off-axis light beams increases. However, it becomes difficult to correct coma aberration, which is the main purpose. If the upper limit is exceeded, the power of the third lens becomes very weak, the load of the power of the second lens increases, the amount of aberration generated by the second lens increases, and it becomes difficult to correct the aberration.
以下、実施例のレンズ・データを記載するが、各記述に
おいてR1,R2・・・はレンズ各面の曲率半径、Ｄ１、Ｄ
２・・・はレンズ面間の肉厚又は空気間隔、N1,N2・・
・は各レンズのｅ線（波長546.1nmの光）に対する屈折
率、ν1，ν2・・・はｅ線に対するアツベ数である。又
非球面の形状は光軸方向をＸ軸とした直角座標において
光軸方向の変位をとするとき であらわされる対称非球面である。Hereinafter, the lens data of the examples will be described. In each description, R 1 , R 2, ... Are the radii of curvature of each surface of the lens, D 1, D.
2 ... is the wall thickness between the lens surfaces or the air gap, N 1 , N 2 ...
Is the refractive index of each lens for the e-line (light having a wavelength of 546.1 nm), and ν 1 , ν 2 ... Are the Abbe numbers for the e-line. Also, the shape of the aspherical surface is when the displacement in the optical axis direction is expressed in rectangular coordinates with the optical axis direction as the X axis. It is a symmetric aspherical surface.
但し、Ｈ：光軸からの高さ Ｒ：頂点の曲率半径 A,B,C,D,E,A′，Ｂ′，Ｃ′，Ｄ′：非球面係数。However, H: height from the optical axis R: radius of curvature of the apex A, B, C, D, E, A ', B', C ', D': aspherical coefficient.
実施例１ 実施例２ 実施例３ 第１図、第２図、第３図に上記各実施例の光学配置図を
示す。各図に於いてL1,L2・・・は各レンズを、Ｓは投
影レンズと映像管との間に配された液体、Ｐは映像管の
管面ガラスをそれぞれあらわす。 Example 1 Example 2 Example 3 FIG. 1, FIG. 2 and FIG. 3 show the optical layout of each of the above embodiments. In each figure, L1, L2 ... Represent each lens, S is a liquid arranged between the projection lens and the picture tube, and P is a tube surface glass of the picture tube.
第４図、第５図、第６図は、各実施例１〜３における各
々の収差曲線（球面収差、非点収差、横収差）である。
尚、Ｍはメリデイオナル像面、Ｓはサジタル像面を示
す。FIG. 4, FIG. 5 and FIG. 6 are aberration curves (spherical aberration, astigmatism, lateral aberration) in each of Examples 1 to 3.
Incidentally, M is a meridional image plane, and S is a sagittal image plane.
以上の如く本発明によれば半画角30°以上、口径比１：
1.2以上の大口径、広画角化で優れた結像性能を有する
高性能の投影レンズを提供することができる。As described above, according to the present invention, the half angle of view is 30 ° or more and the aperture ratio is 1:
It is possible to provide a high-performance projection lens having a large aperture of 1.2 or more, a wide angle of view, and excellent imaging performance.
第１図、第２図、第３図は夫々本発明の実施例を示すレ
ンズ断面図。 第４図、第５図、第６図は夫々実施例の収差曲線図。 図中、L1〜L4はレンズ、Ｒはレンズの曲率半径、Ｄは面
間隔。FIGS. 1, 2, and 3 are lens cross-sectional views showing an embodiment of the present invention. FIG. 4, FIG. 5, and FIG. 6 are aberration curve diagrams of Examples, respectively. In the figure, L 1 to L 4 are lenses, R is the radius of curvature of the lens, and D is the surface spacing.
Claims (1)
投影レンズに於いて、スクリーン側から順に、正の屈折
力を有する第１レンズ、スクリーン側の面に比して曲率
が大で且つ凸なる面を画像側へ向けた正屈折力を有する
第２レンズ、画像側へ凹面を向けたメニスカス第３レン
ズ、画像側の面に比し曲率が大で凹なる面をスクリーン
側へ向けた第４レンズから構成し、更に第１レンズに少
なくとも１面の非球面を設け、第２、第３、第４レンズ
中に１面以上の非球面を設けるとともに以下の条件を満
たすことを特徴とする投影レンズ。 (1)0.75＜φ2,3／φ＜0.95 (2)0.4f＜Ｄ2＜0.6f (3)0.45＜Ｒ5／Ｒ6＜0.85 但し、φは全系の屈折力、φ2,3は第２レンズと第３レ
ンズの合成屈折力、Ｄ2は第１レンズと第２レンズとの
面間隔、Ｒ5は第３レンズのスクリーン側面の曲率半
径、Ｒ6は第３レンズの画像側面の曲率半径。1. A projection lens for enlarging and projecting an image on a screen, wherein a first lens having a positive refracting power and a curvature larger than a surface on the screen side are convex in order from the screen side. The second lens having a positive refractive power with the surface facing toward the image side, the meniscus third lens having the concave surface facing toward the image side, the second lens having a concave surface with a larger curvature than the surface facing the image side facing toward the screen The present invention is characterized by comprising four lenses, further providing at least one aspherical surface on the first lens, providing at least one aspherical surface on the second, third, and fourth lenses, and satisfying the following conditions. Projection lens. (1) 0.75 <φ 2,3 / φ <0.95 (2) 0.4f <D 2 <0.6f (3) 0.45 <R 5 / R 6 <0.85 where φ is the refracting power of the entire system and φ 2,3 Is the combined refractive power of the second lens and the third lens, D 2 is the surface distance between the first lens and the second lens, R 5 is the radius of curvature of the screen side surface of the third lens, R 6 is the image side surface of the third lens Radius of curvature of.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59130635A JPH0638132B2 (en) | 1984-06-25 | 1984-06-25 | Projection lens |
| US06/747,029 US4682861A (en) | 1984-06-25 | 1985-06-20 | Projection lens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59130635A JPH0638132B2 (en) | 1984-06-25 | 1984-06-25 | Projection lens |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS619613A JPS619613A (en) | 1986-01-17 |
| JPH0638132B2 true JPH0638132B2 (en) | 1994-05-18 |
Family
ID=15038960
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59130635A Expired - Lifetime JPH0638132B2 (en) | 1984-06-25 | 1984-06-25 | Projection lens |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0638132B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2523106B2 (en) * | 1986-01-29 | 1996-08-07 | 株式会社日立製作所 | Optical system for projection TV |
| JP2764778B2 (en) * | 1992-10-30 | 1998-06-11 | 株式会社日立製作所 | Optical system for projection television |
| US5329363A (en) * | 1993-06-15 | 1994-07-12 | U. S. Precision Lens Incorporated | Projection lens systems having reduced spherochromatism |
| AT405187B (en) * | 1994-12-01 | 1999-06-25 | Voest Alpine Ind Anlagen | METHOD FOR THE PRODUCTION OF IRON SPONGE AND SYSTEM FOR IMPLEMENTING THE METHOD |
| JP4940459B2 (en) * | 2008-06-24 | 2012-05-30 | 株式会社東電通 | Fixing method and fixing device for cable receiver |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58198017A (en) * | 1982-05-15 | 1983-11-17 | Hitachi Ltd | Projection lens |
-
1984
- 1984-06-25 JP JP59130635A patent/JPH0638132B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS619613A (en) | 1986-01-17 |
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