JPH0449090B2 - - Google Patents

Info

Publication number
JPH0449090B2
JPH0449090B2 JP57103538A JP10353882A JPH0449090B2 JP H0449090 B2 JPH0449090 B2 JP H0449090B2 JP 57103538 A JP57103538 A JP 57103538A JP 10353882 A JP10353882 A JP 10353882A JP H0449090 B2 JPH0449090 B2 JP H0449090B2
Authority
JP
Japan
Prior art keywords
lens group
lens
zooming
refractive power
moves
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
Application number
JP57103538A
Other languages
Japanese (ja)
Other versions
JPS58219513A (en
Inventor
Shigeru Aoki
Kikuo Momyama
Akira Tajima
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Canon Inc
Original Assignee
Canon Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Canon Inc filed Critical Canon Inc
Priority to JP10353882A priority Critical patent/JPS58219513A/en
Publication of JPS58219513A publication Critical patent/JPS58219513A/en
Publication of JPH0449090B2 publication Critical patent/JPH0449090B2/ja
Granted legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B17/00—Systems with reflecting surfaces, with or without refracting elements
    • G02B17/08—Catadioptric systems
    • G02B17/0852—Catadioptric systems having a field corrector only
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B17/00—Systems with reflecting surfaces, with or without refracting elements
    • G02B17/08—Catadioptric systems
    • G02B17/0804—Catadioptric systems using two curved mirrors
    • G02B17/0808—Catadioptric systems using two curved mirrors on-axis systems with at least one of the mirrors having a central aperture
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B17/00—Systems with reflecting surfaces, with or without refracting elements
    • G02B17/08—Catadioptric systems
    • G02B17/0856—Catadioptric systems comprising a refractive element with a reflective surface, the reflection taking place inside the element, e.g. Mangin mirrors
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B17/00—Systems with reflecting surfaces, with or without refracting elements
    • G02B17/08—Catadioptric systems
    • G02B17/0884—Catadioptric systems having a pupil corrector
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B17/00—Systems with reflecting surfaces, with or without refracting elements
    • G02B17/08—Catadioptric systems
    • G02B17/0896—Catadioptric systems with variable magnification or multiple imaging planes, including multispectral systems

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Lenses (AREA)

Description

【発明の詳細な説明】[Detailed description of the invention]

本発明は屈折系と反射系を有した反射屈折式ズ
ームレンズに関し、特に焦点距離の長い望遠用レ
ンズとして好ましい反射屈折式ズームレンズに関
するものである。 一般に屈折系と反射系を有した反射屈折式ズー
ムレンズは光学系の中で結像光束が往復するので
光束のケラレが多くなり、この為所定の明るさの
光学系を得ようとすると、光束のケラレを補う為
どうしても光学系全体が大型化してしまう。 例えば特公昭48−42509号公報で提案されてい
る反射屈折式ズームレンズは２つの屈折系のレン
ズ群すなわち移動レンズ群を屈折系と反射系の間
に配置して、光軸上移動させてズーミングを行つ
ている。 このとき一方のレンズ群すなわち前方レンズ群
を直接的に、他方のレンズ群すなわち後方レンズ
群往復的に移動させてズーミングを行つている。
このようなズームタイプにおいては、一般に移動
レンズ群によつて光束が多くけられる傾向にあ
る。これは前方レンズ群の移動量が多い為であ
る。この為にケラレた光束を補う為にレンズ系全
体の外径を大きくしている。 本発明は、光束のケラレを極力少なくしたズー
ムタイプを採用し小型軽量な反射屈折式ズームレ
ンズを提供することを目的とする。 本発明の目的を達成する為のレンズ構成の特徴
は、光の進行方向に従つて順に、屈折系と光束を
物体側へ反射させる主鏡そして像面側へ光束を反
射させる副鏡、更に屈折レンズとを有し全体とし
てズーミング中固定であつて正の屈折力を有する
第１レンズ群、負の屈折力を有しズーミングの為
に移動する第２レンズ群、正の屈折力を有しズー
ミングの為に移動する第３レンズ群、そしてズー
ミング中固定で負の屈折力を有する第４レンズ群
から成り、前記第３レンズ群は一方向に移動しか
つ前記第２レンズ群よりも多く移動しズーミング
を行つていることである。 このように第２レンズ群の移動量をなるべく少
なくしてその代わりに第３レンズ群の移動量を多
くして所望のズーム比を得ている。これによつて
第２レンズ群によるケラレを少なくしまた第２レ
ンズ群のレンズ外径も小さくすることができ光束
のケラレを更に少なくすることが可能となる。 また第３レンズ群を一方向にのみ移動させるズ
ームタイプを採用し、常に移動によつて変倍が行
われるようにズーミングを効果的に行つている。
そして後述する実施例に示すように第１の反射面
を有する主鏡M1と第２の反斜面を有する副鏡M2
との間隔を適当に保ち、主鏡中央部の穴による光
束のケラレを極力少なくなるように第３レンズ群
を一方向に多く移動させている。 以上のようなレンズ構成で本発明の目的は達成
されるが、更に好ましくは第２レンズ群と第３レ
ンズ群のズーミングによる移動量を各々V2、V3
とするとき 0.08＜V2／V3＜0.3 (1) なる条件式を満足することである。 このように第２レンズ群と第２レンズ群の移動
量の比を定めることにより光束のケラレを少なく
し又ズーミングによる収差変動を少なくすること
ができる。 条件式(1)の上限値を越えると第２レンズ群の移
動量が多くなつて光束のケラレが多くなり好まし
くなく、又条件式(1)の下限値を越えるとズーミン
グによつて第３レンズ群から生ずる収差変動が多
くなつて好ましくない。 尚、本実施例においては第４レンズ群を負の屈
折力とし望遠タイプに近い型とすることによりレ
ンズ全長を更に短くすることができ又軸外の諸収
差の補正を良好に行うことが容易になる。そして
第２レンズ群と第３レンズ群をズーミングにより
近付くように移動させることによつて全ズーム範
囲での収差変動をより少なくしている。 以上述べた構成で本発明の目的とする反射屈折
式ズームレンズは達成されるが更なる良好なる収
差補正を達成するために次の条件を満足するのが
好ましい。第２レンズ群と第３レンズ群を各々少
なくとも１枚の正と負の屈折力を有する２つのレ
ンズを貼り合わせた貼り合わせレンズで構成す
る。これによつてズーミングによる色収差の変動
を少なくすることができる。特に第２レンズ群の
正のレンズのアツベ数が負のレンズのアツベ数よ
り小さくなるようなガラスを選択し、第３レンズ
群の正のレンズのアツベ数の平均が負のレンズの
アツベ数の平均より大きくなるようなガラスを選
択するのが望ましい。尚、本発明に係る反射屈折
式ズームレンズにおけるフオーカシングは第１レ
ンズ群の一部若しくは全部を移動させてもよく、
又第４レンズ群の一部若しくは全部を移動させて
もよい。 次に本発明の数値実施例を示す。レンズ構成の
数値例中、Riは光の進行順序に従つて第ｉ番目の
レンズの曲率半径、Diは第ｉ番目のレンズの軸上
厚またはレンズ間隔、Niとνiは第ｉ番目レンズの
屈折率とアツベ数である。但しDiとNiは光線が左
から右へ進むときを正とするものとする。fiは第
ｉレンズ群の焦点距離である。又表１に本発明に
関する反射屈折式ズームレンズの第２レンズ群と
第３レンズ群の移動量を示す。 The present invention relates to a catadioptric zoom lens having a refractive system and a reflective system, and particularly to a catadioptric zoom lens that is preferable as a telephoto lens with a long focal length. In general, in a catadioptric zoom lens that has a refractive system and a reflective system, the imaging light beam goes back and forth within the optical system, resulting in a lot of vignetting. In order to compensate for the vignetting, the entire optical system inevitably becomes larger. For example, in the catadioptric zoom lens proposed in Japanese Patent Publication No. 48-42509, two refractive lens groups, that is, movable lens groups, are placed between the refractive system and the reflective system, and are moved along the optical axis for zooming. is going on. At this time, zooming is performed by directly moving one lens group, that is, the front lens group, and reciprocating the other lens group, that is, the rear lens group.
In such a zoom type, there is generally a tendency for a large amount of light flux to be eclipsed by the moving lens group. This is because the amount of movement of the front lens group is large. For this reason, the outer diameter of the entire lens system is increased to compensate for the vignetting. SUMMARY OF THE INVENTION An object of the present invention is to provide a small and lightweight catadioptric zoom lens that employs a zoom type that minimizes vignetting of a light beam. The features of the lens configuration for achieving the object of the present invention are as follows: a refractive system, a primary mirror that reflects the light beam toward the object side, a secondary mirror that reflects the light beam toward the image surface side, and a refractor system that sequentially follows the traveling direction of the light. a first lens group that is fixed as a whole during zooming and has a positive refractive power, a second lens group that has a negative refractive power and moves for zooming, and a second lens group that has a positive refractive power and is used for zooming. and a fourth lens group that is fixed during zooming and has a negative refractive power, and the third lens group moves in one direction and moves more than the second lens group. This means that you are zooming. In this way, the desired zoom ratio is obtained by reducing the amount of movement of the second lens group as much as possible and increasing the amount of movement of the third lens group. As a result, vignetting caused by the second lens group can be reduced, and the outer diameter of the lens of the second lens group can also be reduced, making it possible to further reduce vignetting of the light beam. In addition, a zoom type lens is adopted in which the third lens group is moved only in one direction, and zooming is performed effectively so that magnification is constantly changed by movement.
As shown in the embodiments described later, a primary mirror M 1 having a first reflecting surface and a secondary mirror M 2 having a second reverse slope.
The third lens group is moved a lot in one direction so as to maintain an appropriate distance from the main mirror and to minimize vignetting of the light beam due to the hole in the center of the primary mirror. Although the object of the present invention can be achieved with the lens configuration as described above, it is more preferable that the movement amount by zooming of the second lens group and the third lens group is set to V2 and V3, respectively.
The conditional expression 0.08<V2/V3<0.3 (1) must be satisfied. By determining the ratio of the amount of movement between the second lens group and the second lens group in this manner, it is possible to reduce vignetting of the light beam and to reduce fluctuations in aberrations due to zooming. If the upper limit of conditional expression (1) is exceeded, the amount of movement of the second lens group increases, resulting in increased vignetting of the luminous flux, which is undesirable. This is undesirable because the aberration fluctuations caused by the group increase. In this example, by giving the fourth lens group negative refractive power and making it close to a telephoto type, the overall length of the lens can be further shortened, and various off-axis aberrations can be easily corrected. become. By moving the second lens group and the third lens group closer together during zooming, aberration fluctuations over the entire zoom range are further reduced. Although the catadioptric zoom lens which is the object of the present invention can be achieved with the configuration described above, it is preferable to satisfy the following conditions in order to achieve even better aberration correction. The second lens group and the third lens group are each composed of a bonded lens in which two lenses each having at least one positive and negative refractive power are bonded together. This makes it possible to reduce fluctuations in chromatic aberration due to zooming. In particular, select a glass in which the Atbe number of the positive lens in the second lens group is smaller than the Atbe number of the negative lens, and the average Atbe number of the positive lens in the third lens group is smaller than the Atbe number of the negative lens. It is desirable to choose glasses that are larger than average. Note that focusing in the catadioptric zoom lens according to the present invention may be performed by moving part or all of the first lens group,
Further, part or all of the fourth lens group may be moved. Next, numerical examples of the present invention will be shown. In the numerical example of the lens configuration, R i is the radius of curvature of the i-th lens according to the traveling order of light, D i is the axial thickness or lens spacing of the i-th lens, and N i and ν i are the i-th lens distance. These are the refractive index and Atsube number of the th lens. However, D i and N i are assumed to be positive when the ray travels from left to right. f i is the focal length of the i-th lens group. Further, Table 1 shows the amount of movement of the second lens group and the third lens group of the catadioptric zoom lens according to the present invention.

【表】 実施例 １ f1＝52.903 f2＝−5.938 f3＝7.822 f4＝−67.051[Table] Example 1 f 1 = 52.903 f 2 = -5.938 f 3 = 7.822 f 4 = -67.051

【表】 第２レンズ群の移動量 V2＝0.351 第３レンズ群の移動量 V3＝2.262 V2／V3＝0.155[Table] Amount of movement of the second lens group V 2 = 0.351 Amount of movement of the third lens group V 3 = 2.262 V 2 /V 3 = 0.155

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明に関する実施例のレンズ断面図
である。第１−ａ図は本発明に関するズームレン
ズの広角端のズーム位置での収差図である。第１
−ｂ図は本発明に関するズームレンズの中間のズ
ーム位置での収差図である。第１−ｃ図は本発明
に関するズームレンズの望遠端のズーム位置での
収差図である。 図中矢印はズーミングによるレンズ群の移動方
向を、，，，は各々第１、第２、第３、
第４レンズ群を、Ｍはメリヂオナル像面、Ｓはサ
ジタル像面、M1は主鏡、M2は副鏡を示す。 FIG. 1 is a sectional view of a lens according to an embodiment of the present invention. FIG. 1-a is an aberration diagram at the wide-angle end zoom position of the zoom lens according to the present invention. 1st
Figure -b is an aberration diagram at an intermediate zoom position of the zoom lens according to the present invention. FIG. 1-c is an aberration diagram at the telephoto end zoom position of the zoom lens according to the present invention. The arrows in the figure indicate the moving directions of the lens groups during zooming, and the arrows indicate the first, second, third, and third lens groups, respectively.
In the fourth lens group, M is a meridional image surface, S is a sagittal image surface, M 1 is a primary mirror, and M 2 is a secondary mirror.

Claims (1)

【特許請求の範囲】 １ 光の進行方向に従つて順に、屈折系と光束を
物体側へ反射させる主鏡そして像面側へ光束を反
射させる副鏡、更に屈折レンズとを有し全体とし
てズーミング中固定であつて正の屈折力を有する
第１レンズ群、負の屈折力を有しズーミングの為
に移動する第２レンズ群、正の屈折力を有しズー
ミングの為に移動する第３レンズ群、そしてズー
ミング中固定で負の屈折力を有する第４レンズ群
から成り、前記第３レンズ群は一方向に移動しか
つ前記第２レンズ群よりも多く移動しズーミング
を行うことを特徴とする反射屈折式ズームレン
ズ。 ２ 前記第２レンズ群と前記第３レンズ群のズー
ミングによる移動量を各々V2、V3とするとき 0.08＜V2／V3＜0.3 なる条件式を満足することを特徴とする特許請求
の範囲第１項記載の反射屈折式ズームレンズ。[Claims] 1. In order according to the traveling direction of the light, a refractive system, a primary mirror that reflects the light beam toward the object side, a secondary mirror that reflects the light beam toward the image plane side, and a refractive lens are provided, and the zooming system is used as a whole. A first lens group that is medium fixed and has a positive refractive power, a second lens group that has a negative refractive power and moves for zooming, and a third lens group that has a positive refractive power and moves for zooming. and a fourth lens group that is fixed during zooming and has a negative refractive power, and the third lens group moves in one direction and moves more than the second lens group to perform zooming. Catadioptric zoom lens. 2. Claim 1, characterized in that the following conditional expression is satisfied: 0.08<V2/V3<0.3, where the amounts of movement due to zooming of the second lens group and the third lens group are V2 and V3, respectively. The catadioptric zoom lens described.
JP10353882A 1982-06-15 1982-06-15 Reflective and refractive type zoom lens Granted JPS58219513A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10353882A JPS58219513A (en) 1982-06-15 1982-06-15 Reflective and refractive type zoom lens

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10353882A JPS58219513A (en) 1982-06-15 1982-06-15 Reflective and refractive type zoom lens

Publications (2)

Publication Number Publication Date
JPS58219513A JPS58219513A (en) 1983-12-21
JPH0449090B2 true JPH0449090B2 (en) 1992-08-10

Family

ID=14356618

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10353882A Granted JPS58219513A (en) 1982-06-15 1982-06-15 Reflective and refractive type zoom lens

Country Status (1)

Country Link
JP (1) JPS58219513A (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11221470B2 (en) * 2018-02-27 2022-01-11 Fujifilm Corporation Variable magnification optical system and imaging apparatus

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55157710A (en) * 1979-05-14 1980-12-08 Applied Systems Corp Zoom optical system
JPS5744115A (en) * 1980-08-30 1982-03-12 Asahi Optical Co Ltd Reflex telephoto zoom lens system
JPS57103537A (en) * 1980-12-19 1982-06-28 Oki Electric Ind Co Ltd Data input device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55157710A (en) * 1979-05-14 1980-12-08 Applied Systems Corp Zoom optical system
JPS5744115A (en) * 1980-08-30 1982-03-12 Asahi Optical Co Ltd Reflex telephoto zoom lens system
JPS57103537A (en) * 1980-12-19 1982-06-28 Oki Electric Ind Co Ltd Data input device

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Publication number Publication date
JPS58219513A (en) 1983-12-21

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