JPH0233208Y2 - - Google Patents
Info
- Publication number
- JPH0233208Y2 JPH0233208Y2 JP3834981U JP3834981U JPH0233208Y2 JP H0233208 Y2 JPH0233208 Y2 JP H0233208Y2 JP 3834981 U JP3834981 U JP 3834981U JP 3834981 U JP3834981 U JP 3834981U JP H0233208 Y2 JPH0233208 Y2 JP H0233208Y2
- Authority
- JP
- Japan
- Prior art keywords
- lens
- primary mirror
- optical system
- negative meniscus
- maksutov
- 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
- 230000003287 optical effect Effects 0.000 claims description 11
- 230000005499 meniscus Effects 0.000 claims description 6
- 239000011521 glass Substances 0.000 claims description 2
- 230000004075 alteration Effects 0.000 description 10
- 201000009310 astigmatism Diseases 0.000 description 2
- 230000002542 deteriorative effect Effects 0.000 description 1
Landscapes
- Telescopes (AREA)
- Lenses (AREA)
Description
従来のマクストーフ方式の天体望遠鏡の光学系
は第１図に示す如く、表面反射面M′を有した主
鏡L1′と、主鏡L1′で発生する球面収差を補正する
ために、主鏡L1′の前方に距離をおいて設けられ
た入射光線に対して凹面を向けた負のメニスカス
レンズL2′とから構成される。（例えば、特公昭52
−115243号参照）
本考案のマクストーフ方式のカセグレイン天体
望遠鏡の光学系は、主鏡L2によつて反射された
光線を、再び補正レンズL1によつて反射させて
主鏡L2の後方に結像させるものである。
第２図に示すように本考案は、入射光線に対し
凹面を向けた負のメニスカスレンズの前面の中央
部分に二次反射面M1を有した補正レンズL1と大
きな空気間隔をあけて設けられた裏面反射面M2
を有する中央部分に穴のあいた主鏡L2と、主鏡
L2の後方、すなわち、本光学系の焦点面Ｐ近辺
には正の焦点距離を有した両凸レンズL3と負の
メニスカスレンズL4が空気間隔を有して配置さ
れ、二次反射面M1の直径の小さな、しかも各収
差が良好に補正された望遠比が0.29と非常にコン
パクトなマクストーフ方式のカセグレイン天体望
遠鏡である。
本考案の光学系の特色を列記すると、
(1) 天体望遠鏡の対物レンズとして用いられる光
学系は、特に球面収差が良好に補正されていな
ければならない。
本考案では、主鏡L2を裏面反射にし、光線
を２回主鏡L2に通過させることゝ、主鏡L2の
各面の曲率半径の選択によつて球面収差の発生
を極力抑制している。
(2) 入射光線の面積に比して、二次反射面M1の
面積が占める割合が大きくなると、二次反射面
M1によつて生じる回折によつて星像観測の場
合回折リングの光量が増し、星像が不自然にな
り、且つ、像の鮮鋭度が劣化する。
本考案では、補正レンズL1の前面に二次反射
面M1を設けることによつて二次反射面M1の大き
さを小さく抑えて前述の欠点を補なつている。更
に、補正レンズL1に光線を２回通過させること
によつて主に球面収差の発生を抑えている。通
常、入射平行光線の入射高h1と二次反射面M1に
あたる光線高h7とすると、本考案ではh7／h1＝1/
３．８と小さくなつた。
(3) 天体望遠鏡の光学系では、各レンズの光軸に
対する偏心を小さくするために、より簡単な光
学系が望まれ、且つ、金枠設計の面からも各レ
ンズの配置を工夫して極力偏心を避けなければ
ならない。
本考案では二次反射面M1を補正レンズL1の第
１面と共用にし、且つ、像面歪曲収差の補正に有
効な補正レンズL3，L4を主鏡L2の後方、すなわ
ち、本光学系の焦点面Ｐの近辺に配置することに
より補正レンズL3，L4の精度を良く配置するこ
とができる。
補正レンズL3及びL4は、空気間隔を有した両
凸レンズと負のメニスカスレンズからなり、正の
焦点距離を有する。しかも、R10＞｜R11｜の条
件を満たすことによつて像面歪曲収差の補正を良
好に行つている。
本考案はこのような構成の下で二次反射面M1
の直径が小さく、しかも望遠比が0.29と極めてコ
ンパクトなマクストーフ方式のカセグレイン天体
望遠鏡であつて、次の如き実施光学データーを有
するものである。
As shown in Figure 1, the optical system of a conventional Maksutov astronomical telescope consists of a primary mirror L 1 ′ with a surface reflecting surface M′ and a main mirror L 1 ′ to correct the spherical aberration that occurs in the primary mirror L 1 ′. It consists of a negative meniscus lens L 2 ′ with a concave surface facing the incident light beam, which is placed at a distance in front of the mirror L 1 ′. (For example, Tokuko Sho 52
(Refer to No. 115243) The optical system of the Maksutov type Cassegrain astronomical telescope of the present invention reflects the light beam reflected by the primary mirror L 2 again by the correction lens L 1 and returns it to the rear of the primary mirror L 2 . It forms an image. As shown in Figure 2, the present invention consists of a negative meniscus lens with a concave surface facing the incident light beam, and a correction lens L 1 having a secondary reflection surface M 1 at the center of the front surface with a large air gap. Back reflective surface M 2
A primary mirror L 2 with a hole in the center and a primary mirror
Behind L2 , that is, near the focal plane P of this optical system, a biconvex lens L3 with a positive focal length and a negative meniscus lens L4 are arranged with an air gap, and a secondary reflection surface M It is an extremely compact Maksutov-type Cassegrain astronomical telescope with a small diameter of 1.1 and a telephoto ratio of 0.29, with each aberration well corrected. The features of the optical system of the present invention are listed below: (1) The optical system used as the objective lens of an astronomical telescope must be particularly well corrected for spherical aberration. In this invention, the primary mirror L 2 is back-reflective, the light beam passes through the primary mirror L 2 twice, and the occurrence of spherical aberration is suppressed as much as possible by selecting the radius of curvature of each surface of the primary mirror L 2 . ing. (2) When the area of the secondary reflection surface M 1 becomes larger than the area of the incident light beam, the secondary reflection surface
Diffraction caused by M 1 increases the light intensity of the diffraction ring during star image observation, making the star image unnatural and deteriorating the sharpness of the image. In the present invention, the size of the secondary reflection surface M 1 is kept small by providing the secondary reflection surface M 1 on the front surface of the correction lens L 1 to compensate for the above-mentioned drawbacks. Furthermore, by causing the light beam to pass through the correction lens L1 twice, the occurrence of spherical aberration is mainly suppressed. Normally, if the incident height of the incident parallel ray is h 1 and the ray height h 7 that hits the secondary reflection surface M 1 , then in this invention, h 7 /h 1 = 1/
It became smaller at 3.8. (3) In the optical system of an astronomical telescope, a simpler optical system is desired in order to reduce the eccentricity of each lens with respect to the optical axis. Eccentricity must be avoided. In the present invention, the secondary reflection surface M 1 is shared with the first surface of the correction lens L 1 , and the correction lenses L 3 and L 4 , which are effective in correcting field distortion aberration, are placed behind the primary mirror L 2 , that is, By arranging them near the focal plane P of this optical system, the correction lenses L 3 and L 4 can be arranged with good accuracy. The correction lenses L 3 and L 4 consist of a biconvex lens with an air gap and a negative meniscus lens, and have a positive focal length. Moreover, by satisfying the condition R 10 >|R 11 |, field distortion can be corrected well. The present invention uses the secondary reflecting surface M 1 under such a configuration.
It is an extremely compact Maksutov-type Cassegrain astronomical telescope with a small diameter and a telephoto ratio of 0.29, and has the following optical data.
【表】【table】
【表】
〓ν〓使用ガラスのアツベ数
本考案の精能は第３図（球面収差）、（非
点収差）、（歪曲収差）に示す如く、焦点距離
ｆ＝1.950mmの場合の各収差図の通りである。[Table] 〓ν〓Number of heat of glass used
The precision of the present invention is as shown in Figure 3 (spherical aberration), (astigmatism), and (distortion aberration) when the focal length f = 1.950 mm.
第１図は従来のマクストーフ方式の天体望遠鏡
の断面図、第２図は本考案のマクストーフ方式の
カセグレイン天体望遠鏡の断面図、第３図は各収
差グラフ図で、は球面収差、は非点収差、
は歪曲収差を示す。
尚、図中符号L1，L2，L3，L4……レンズ、Ｐ
……焦点面である。
Figure 1 is a cross-sectional view of a conventional Maksutov type astronomical telescope, Figure 2 is a cross-sectional view of the Maksutov type Cassegrain astronomical telescope of the present invention, and Figure 3 is a graph of each aberration, where spherical aberration and astigmatism are shown. ,
indicates distortion. In addition, the symbols L 1 , L 2 , L 3 , L 4 in the figure...lens, P
...This is the focal plane.
Claims (1)
た負のメニスカスレンズであり、又、補正レンズ
L1の前面の中央部に反射メツキが施されており
裏面に反射メツキを施し、中央部に穴を設けた主
鏡L2とは大きな空気間隔を有して配置し、主鏡
L2の後方、すなわち、本光学系の焦点面Ｐ近辺
には正の焦点距離を有した両凸レンズL3、負の
メニスカスレンズL4を空気間隔を有して配置し、 【表】 【表】 〓ν〓使用ガラスのアツベ数
よりなるマクストーフ方式のカセグレイン天体望
鏡。[Claims for Utility Model Registration] The correction lens L 1 is a negative meniscus lens with a concave surface facing the incident light beam, and is also a correction lens.
The central part of the front of L 1 is reflectively plated, the back side is reflectively plated, and the primary mirror L 2 has a hole in the center.
Behind L 2 , that is, near the focal plane P of this optical system, a biconvex lens L 3 with a positive focal length and a negative meniscus lens L 4 are arranged with an air gap. ] 〓ν〓Number of heat of glass used
A Maksutov style Cassegrain astronomical telescope.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3834981U JPH0233208Y2 (en) | 1981-03-20 | 1981-03-20 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3834981U JPH0233208Y2 (en) | 1981-03-20 | 1981-03-20 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57153317U JPS57153317U (en) | 1982-09-27 |
| JPH0233208Y2 true JPH0233208Y2 (en) | 1990-09-07 |
Family
ID=29835510
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3834981U Expired JPH0233208Y2 (en) | 1981-03-20 | 1981-03-20 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0233208Y2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8488237B2 (en) * | 2011-01-12 | 2013-07-16 | Raytheon Company | Wide spectral coverage Ross corrected Cassegrain-like telescope |
| JP5915489B2 (en) * | 2012-10-04 | 2016-05-11 | ソニー株式会社 | Catadioptric lens system and imaging apparatus |
| US9846299B2 (en) * | 2013-04-05 | 2017-12-19 | University Of Florida Research Foundation, Incorporated | Telescope and telescope array for use in spacecraft |
-
1981
- 1981-03-20 JP JP3834981U patent/JPH0233208Y2/ja not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57153317U (en) | 1982-09-27 |
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