JPH02181713A - Finder optical system - Google Patents

Finder optical system

Info

Publication number
JPH02181713A
JPH02181713A JP233189A JP233189A JPH02181713A JP H02181713 A JPH02181713 A JP H02181713A JP 233189 A JP233189 A JP 233189A JP 233189 A JP233189 A JP 233189A JP H02181713 A JPH02181713 A JP H02181713A
Authority
JP
Japan
Prior art keywords
lens
optical system
distance
finder optical
magnification
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.)
Granted
Application number
JP233189A
Other languages
Japanese (ja)
Other versions
JPH0758368B2 (en
Inventor
Saburo Sugawara
三郎 菅原
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.)
Pentax Corp
Original Assignee
Asahi Kogaku Kogyo Co Ltd
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 Asahi Kogaku Kogyo Co Ltd filed Critical Asahi Kogaku Kogyo Co Ltd
Priority to JP1002331A priority Critical patent/JPH0758368B2/en
Priority to GB9000066A priority patent/GB2227104B/en
Priority to FR9000180A priority patent/FR2641621B1/en
Priority to DE19904000448 priority patent/DE4000448C2/en
Priority to US07/549,987 priority patent/US5136427A/en
Publication of JPH02181713A publication Critical patent/JPH02181713A/en
Publication of JPH0758368B2 publication Critical patent/JPH0758368B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B23/00—Telescopes, e.g. binoculars; Periscopes; Instruments for viewing the inside of hollow bodies; Viewfinders; Optical aiming or sighting devices
    • G02B23/14—Viewfinders
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B19/00—Cameras
    • G03B19/02—Still-picture cameras
    • G03B19/12—Reflex cameras with single objective and a movable reflector or a partly-transmitting mirror

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Astronomy & Astrophysics (AREA)
  • Optics & Photonics (AREA)
  • Lenses (AREA)
  • Viewfinders (AREA)

Abstract

PURPOSE:To obtain an optical system whose magnification is high without using a prism and which is excellent in various aberrations with a small number of lenses by using a pentagonal mirror, constituting a lens system of two groups of two lenses and satisfying a specified condition. CONSTITUTION:The pentagonal mirror is used instead of a pentagonal prism and the lens system is constituted of a 1st lens being a positive single lens and a 2nd lens being a negative single lens from a finder screen side. Supposing about a shape factor SF that the radius of curvature of the surface of each lens on the finder screen side is Rs and the radius of curvature of the surface on an eye point side is Re, it is defined as SF=(Rs+Re)/(Rs-Re). By taking the shape factors of the 1st and the 2nd lenses as SF1 and SF2 respectively, conditional expressions I and II are allowed to be satisfied.

Description

【発明の詳細な説明】 「産業上の利用分野」 本発明はペンタプリズムの代りにペンタミラーを用いた
一眼レフカメラ等に用いられるファインダー光学系に関
するものである。DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a finder optical system used in single-lens reflex cameras and the like that uses a pentamirror instead of a pentaprism.

「従来の技術」 従来、ペンタプリズムの代りにペンタミラーを用いた一
眼レフカメラ用ファインダー光学系として、実公昭４８
−３２３２５号や実公昭４８−１０４２４号が提供され
ている。``Prior art'' Conventionally, a finder optical system for single-lens reflex cameras using a pentamirror instead of a pentaprism was developed in 1973.
-32325 and Utility Model Publication No. 48-10424 are provided.

「発明が解決しようとする課題」 しかしながら、これらのファインダー光学系は、ペンタ
プリズムを用いた従来の一眼レフカメラ用ファインダー
光学系と比較して、倍率の低下は少ないが、レンズ枚数
が多いためアイピー大部分のレンズ全長が増大し、カメ
ラの小型化の妨げになるという課題があった。また高価
なガラスを使用しているので、コストが高いという課題
もあった。"Problem to be Solved by the Invention" However, although these finder optical systems have less reduction in magnification than conventional finder optical systems for single-lens reflex cameras that use a pentaprism, they have a large number of lenses, making them difficult to use for eye protection. The problem was that the overall length of most of the lenses increased, which hindered the miniaturization of cameras. Furthermore, since expensive glass is used, there is also the problem of high cost.

本発明は、上述したようなａ題を解決すべくなされたも
ので、２群２枚という簡単な構成でありながら、見え味
がよく（性能良好な）、かつ小型であるのに加え１倍率
が高く、また安価なペンタミラー用一眼レフファインダ
ー光学系を提供することを目的とするものである。The present invention was made to solve problem a as described above, and has a simple configuration of two elements in two groups, good visibility (good performance), small size, and 1 magnification. The object of the present invention is to provide a single-lens reflex finder optical system for a pentamirror that is high in performance and inexpensive.

［課題を解決するための手段」 上記目的を達成するために、本発明のファインダー光学
系は、一眼レフカメラにおけるファインダースクリーン
側から、正の単レンズから成る第ルンズと、負の単レン
ズから成る第２レンズとから構成され、前記第１及び第
２レンズのシェイプファクターをそれぞれＳＦ１、ＳＦ
２とし、シェイプファクターＳＦは各レンズのファイン
ダースクリーン側の面の曲率半径をＲＳ、アイポイント
側の面の曲率半径をＲＥとするとき Ｒ８−Ｒ１： で定義するものとし、 （１）　−２＜　ＳＦＩ　＜　０ （２）　　Ｏ＜　ＳＦ２　＜　３ の各条件を満足することを特徴としている。[Means for Solving the Problems] In order to achieve the above object, the finder optical system of the present invention includes, from the finder screen side of a single-lens reflex camera, a first lens consisting of a positive single lens and a negative single lens. and a second lens, and the shape factors of the first and second lenses are SF1 and SF, respectively.
2, and the shape factor SF is defined as R8-R1: where RS is the radius of curvature of the surface on the finder screen side of each lens and RE is the radius of curvature on the surface on the eyepoint side, and (1) -2< It is characterized by satisfying the following conditions: SFI < 0 (2) O < SF2 < 3.

また上述のように構成されたファイダー光学系において
、前記第ルンズおよび前記第２レンズを構成する４面の
うち、少なくとも１面は非球面で構成されることを特徴
としている。Furthermore, the viewfinder optical system configured as described above is characterized in that at least one of the four surfaces forming the first lens and the second lens is an aspherical surface.

尚、非球面形状は次式で表わされる。Note that the aspherical shape is expressed by the following equation.

二二で Ｘ；頂点から光軸方向に光線の進む向きにとった距離 ｙ；光軸からの高さ Ｒ；基準球面の曲率半径 に；回転２次曲面形状係数 Ａ、ｋ　；高次非球面係数 更に、前記第ルンズの光軸方向の厚さをｄｘｐ前記第ル
ンズと前記第２レンズの光軸上の間隔をｄ２１前記第２
レンズの光軸方向の厚さをｄ　３１フアインダー光学系
の合成焦点距離をｆとしたとき、 （３）　０．０５　＜　（ｄ□＋ｃｔ、−１−ａｓ）　
／　ｆ＜　ｏ、３の条件を満足することを特徴としてい
る。22 X; Distance y from the vertex in the direction of the optical axis; Height R from the optical axis; Radius of curvature of the reference sphere; Rotational quadratic shape coefficients A, k; Higher-order aspheric surface Furthermore, the coefficient dxp is the thickness of the first lens in the optical axis direction, and d21 is the distance between the second lens and the second lens on the optical axis.
When the thickness of the lens in the optical axis direction is d and the combined focal length of the 31 finder optical system is f, (3) 0.05 < (d□+ct, -1-as)
It is characterized by satisfying the following condition: / f < o, 3.

加えて、前記第ルンズはアクリル樹脂、前記第２レンズ
はポリカーボネート樹脂を用いることを特徴としている
。尚、前記第ルンズはアクリル樹脂とアツベ数が同程度
のクラウン系ガラス。In addition, the first lens is made of acrylic resin, and the second lens is made of polycarbonate resin. Incidentally, the above-mentioned lunes are crown-based glass having the same level of heat resistance as acrylic resin.

第２レンズはポリカーボネート樹脂とアツベ数が同程度
のフリント系ガラスで構成しても同様の性能が得られる
。Similar performance can be obtained even if the second lens is made of flint-based glass having the same Abbe number as polycarbonate resin.

「作用」 条件（１）は第ルンズの形状の関係を表わしたもので、
ＳＦＩがこの条件（１）の下限を超えると、コマ収差の
補正は容易に行なえるが、球面収差の補正が困難となり
好ましくない。逆に上限を超えると、球面収差の補正は
容易に行なえるが。"Action" Condition (1) expresses the relationship between the shapes of the lunches,
If the SFI exceeds the lower limit of condition (1), comatic aberration can be easily corrected, but spherical aberration will be difficult to correct, which is not preferable. On the other hand, if the upper limit is exceeded, spherical aberration can be easily corrected.

コマ収差の補正が困難となり好ましくないのに加え、第
ルンズと第２レンズの周辺部の間隔が拡がるため第ルン
ズの有効径が大きくなり好ましくない。This is not only undesirable because it makes it difficult to correct comatic aberration, but also because the distance between the peripheral portions of the first lens and the second lens is widened, which is undesirable because the effective diameter of the first lens becomes large.

条件（２）は第２レンズの形状の関係を表わしたもので
、ＳＦ２がこの条件（２）の下限を超えると、コマ収差
の補正が困難となり好ましくない。Condition (2) expresses the relationship between the shapes of the second lens, and if SF2 exceeds the lower limit of condition (2), it will be difficult to correct coma aberration, which is not preferable.

逆に上限を超えると、アイポイント側の面の曲率半径が
小さくなるので、事実上アイポイントが短くなってしま
い好ましくない。On the other hand, if the upper limit is exceeded, the radius of curvature of the surface on the eyepoint side becomes smaller, which effectively shortens the eyepoint, which is not preferable.

また、更に性能を良好に保つためには、前記第ルンズお
よび前記第２レンズを構成する４面のうち、少なくとも
１面に非球面を用いることが好ましい。即ち、非球面を
用いない場合、視野周辺部においてコマ収差や中心に対
する視度変化が著しく発生するので好ましくない、特に
倍率を大きくするために第ルンズと第２レンズの間隔を
拡げた場合には、上記収差の発生が著しい。Moreover, in order to further maintain good performance, it is preferable to use an aspherical surface for at least one of the four surfaces constituting the first lens and the second lens. In other words, if an aspherical surface is not used, coma aberration and diopter changes with respect to the center will occur significantly at the periphery of the field of view, which is undesirable, especially when the distance between the first lens and the second lens is widened to increase magnification. , the occurrence of the above-mentioned aberrations is significant.

条件（３）はファインダー光学系の合成焦点距離に対す
るファインダー光学系全長の比に関するもので、この条
件（３）の下限を超えると、高い倍率が得られず好まし
くなく、逆に上限を超えると、高い倍率は得られるが、
第ルンズの有効径が大きくなり好ましくない。Condition (3) relates to the ratio of the overall length of the finder optical system to the combined focal length of the finder optical system.If the lower limit of this condition (3) is exceeded, high magnification cannot be obtained, which is undesirable.On the other hand, if the upper limit is exceeded, Although high magnification can be obtained,
This is not preferable because the effective diameter of the first lunion becomes large.

更に、色収差補正の点から考えて、前記第ルンズはアク
リル樹脂あるいはクラウン系ガラスを用い、前記第２レ
ンズはポリカーボネート樹脂あるいはフリント系ガラス
を用いるのが好ましい。Furthermore, in view of correcting chromatic aberration, it is preferable that the first lens is made of acrylic resin or crown-based glass, and that the second lens is made of polycarbonate resin or flint-based glass.

また、樹脂レンズを用いることにより軽量化、低コスト
化も計れる。Furthermore, by using a resin lens, it is possible to reduce the weight and cost.

ｒ実施例」 次に本発明の実施例１〜１２を示す。r Example” Next, Examples 1 to 12 of the present invention will be shown.

ここで、ｒｉは第１面の曲率半径、ｄｉは第１面と第（
ｉ＋１）面の間隔、ｎｊｔ　ＶＪはそれぞれ第ｊ番目の
レンズ（硝材）のｄ−１ｉｎｅの屈祈率及びアツベ数、
Ｋ　ＩＨＡ４１　、　Ａ＠　１はそれぞれ第１面の回転
２次曲面形状係数、４次非球面係数、６次非球面係数で
ある。Here, ri is the radius of curvature of the first surface, and di is the radius of curvature of the first surface and the (
i+1) plane spacing, njt VJ are the d-1ine refractive index and Atsbe number of the j-th lens (glass material), respectively;
K IHA41 and A@1 are the rotational quadric surface shape coefficient, the fourth-order aspherical surface coefficient, and the sixth-order aspherical surface coefficient of the first surface, respectively.

〔実施例１〕 面Ｎｏ　　ｒＪ １　１５．５３４ ２−２８．３５７ ３−５３．２３８ ｄｌ　　　　ｎｊ　　　　ｑｊｋ４　　　　Ａｓｋ６．
４７６　１．４９１８６　５７．４　−０．２３６８４
　−７．７４０６１ＸｌＯ−２，１５４−７，３７０１
８ １１、父５４７　２９．９ 鎗旅例２〕 面）ＪＯｒｉ　　　ｄｉ　　　　ｎＪ　　　’　　９ｊ
ｋｉ　　　　　Ａｓｋｌ　　　１４．４８９　６．２２
４　１．４９１８６　５７．４　−０．３４４４７　−
７．２８８８２ＸＬＯ′２　−３４．５０１　２．００
５　　　　　　　　　−１１．６６９４３−１４６．３
０５　　１　　１．５８５４７　２９．９スクリーン面
から第１面までの距離 第４面からアイポイントまでの距離 視野率　９５％ ｆ　＝７０．２２９ 倍率　０．７４０倍（５２／７０．２２９）Ｓ　Ｆ　１
　＝−０，２９２ Ｓ　Ｆ　２　＝　０．４９５ （ｄ１＋　ｄ、＋　ｄ、）　／　ｆ　＝０．１３７８１
．００４ スクリーン面から第１面までの距離　８１，００４第４
面からアイポイントまでの距離　　１５視野率　９５％ ｆ　＝６９．０６１ 倍率　０．７４３倍（５２／６９．９６１）Ｓ　Ｆ　１
　＝−０，４０８ ８Ｆ　２　＝＝　０．８１４ （ｄ、＋ｄ２＋ｄ、）／ｆ＝０．１３２峡痛例３〕 面ＰＪｏｒｉ １　　１３．２３１ ２　−２４．３８７ ３−１１０．５３５ ｄｌｎｊ　　　　　９Ｊ ８．２０３　１．４９１１ｓ６　５７．４１．２３１ １　　　１．７１７３６　２９．３ ｋｉ　　　　　Ａｒ１ −０．２７５　−１．３０３１６ｘｌＯ−’−９．８０
５７３　２．４７０２５Ｘ１０′鎗痛例４〕 面Ｎｏ　　ｒ翫 １　　１４．６７８ ２　−２８．２６７ ３−３３３．８１５ ｄｌ　　　ｎＪ９３　　　ｋｌ　　　　Ａ＠１？、６　
　１．４９１８６　５７．４−０．３８８４９−９．０
８４８７Ｘ１０”２．１５３　　　　　　　　　−９．
０４１０８１　　１．８０５１８　２５．４ スクリ一ン面から第１面までの距離　８１，００４第４
面からアイポイントまでの距離　　１５視野率　９５％ ｆ　＝６７．０３ 倍率　０．７７６倍（５２／６７．０３）Ｓ　Ｆ　１　
＝−０，２９７ Ｓ　Ｆ　２　＝　０．７６１ （ｄ、＋　ｄ２＋　ｄ３）　／　ｆ　＝０．１５６スク
リ一ン面から第１面までの距離　８１．００４第４面か
らアイポイントまでの距離　　１５視野率　９５％ ｆ　＝６７．３１４ 倍率　０．７７２倍（５２／６７．３１４）Ｓ　Ｆ　１
　＝−０，３１６ Ｓ　Ｆ　２　＝　０．８９８ （ｄ、＋　ｄ２＋　ｄ、）　／　ｆ　＝０．１６０洟施
例５〕 面Ｎｏ　　ｒｌ １　１３．９４４ ２　−３１．３０６ ３　１３６．９３４ ｄｌｎＪ　　　　′１１Ｊ　　　ＩＪ　　　　　Ａ＠＞
７．５４ｇ　　１．４９１８６　５７．４　−０．４３
６２８　−９．２８３９１Ｘ１０−１．９４　　　　　
　　　　　−１２．３１７４１　　　１．８０５１８　
２５．４ 峡施例６〕 面Ｎｏ　　ｒ’１ １　　１２．４７２ ２　−６９．８８６ ３　　３０．５２８ ４　　１１．２８８ ｄｌ　　　　ｎｊ　　　　ｙＪ　　　ｋｉ　　　　　Ａ
＠（７，２３７１，４９１８６５７，４−０，４９０２
７−８，４００７８Ｘ１０−１．９４４　　　　　　　
　　−５３．６１６９１１、閉５１ｇ　　２５．４ スクリーン面から第１面までの距Ｍ　　８１．００４第
４面からアイポイントまでの距離　　１５視野率　９５
％ ｆ　＝６６．９２７ 倍率　０．７７７倍（５２／６６．９２７）Ｓ　Ｆ　１
　＝−０，３８４ Ｓ　Ｆ　２　＝　１．２４６ （ｄ１＋　ｄ、＋　ｄ、）　／　ｆ　＝０．１５７スク
リ一ン面から第１面までの距離　８１．００４第４面か
らアイポイントまでの距離　　１５視野率　９５％ ｆ　＝６５．５８ 倍率　０．７９３倍（５２／６５．５８）Ｓ　Ｆ　１　
＝−０，６９７ Ｓ　Ｆ　２　＝　２．１７３ （ｄ、＋　ｄ、＋　ｄ３）　／　ｆ　＝０．１５５け腕
側７〕 ’Ｆ６ｏ　　ｒｈ １　　１６．５８９ ２　−３８．０５１ ３−１４２．６６９ ｄｌ　　　　ｎＪ　　　　　ｖｊｋ４ ５．９８９　１．４９１８６　５７．４　−０．８８３
２１３．１４４ １　　１．５＆５４７　２９．９ ａｌ −１，０Ｏ０７７Ｘ１０−’ 洟施例８〕 面Ｎｏｒ１ １　１５．０９１ ２　−２４．６６５ ３　−３１．２６２ ４　２０．５１０ ｄｌ　　　ｎｊ　　　　νｊｋｋ ６．８１４　１．４９１８６　５７．４１．８２０　　
　　　　　−６．００１９８１　　１．５８５４７　２
９．９ Ａ＠ｉ ８゜９＆４７６　Ｘ　１０４ スクリーン面から第１面までの距離　８１．００４第４
面からアイポイントまでの距離　　１５視野率　９５％ ｆ　＝７０．０６６ 倍率　０．７４２倍（５２／７０．０６６）Ｓ　Ｆ　１
　＝−０，３９３ Ｓ　Ｆ　２　＝　０．７７６ （ｄ工＋ｄ＊”　ｄａ）　／　ｆ　＝Ｏ０１４５スクリ
ーン面から第１面までの距離　８１．００４第４面から
アイポイントまでの距離１５視野率　９５％ ｆ　＝７０．２７３ 倍率　０．７４０倍（５２／７０．２７３）Ｓ　Ｆ　１
　＝−０，２４１ Ｓ　Ｆ　２　＝　０．２０８ （ｄ、＋　ｄ２＋　ｄ３）　／　ｆ　＝０．１３７洟施
例９〕 面リ　ｒｉ １　１３．９９１ ２　−５１．４２２ ３　−８６．０６５ ｄｌ　　　　ｎＪ　　　　ｖｊｋ・ ６．１６８　１．４９１＆６　５７．４２．２５０ １　　１．５＆５４７　２９．９　５８．９１７５５ｉ −５，２７５２１ｘ　１０−” ｊ差例１０〕 面Ｎｏ　　ｒ’１ １　　１２．４６３ ２　−７３．２６５ ３　−６０．３３４ ４　　１８．１６５ ｄｌ　　　　ｎＪ　　　　　νｊ　　　　ｋｉ６．５０
２　１．４９１８６　５７．４１．８１３６ １　　　１．５８５４７　２９．９ ４．４００４４ Ａ。[Example 1] Surface No rJ 1 15.534 2-28.357 3-53.238 dl nj qjk4 Ask6.
476 1.49186 57.4 -0.23684
-7.74061XlO-2,154-7,3701
8 11, Father 547 29.9 Yari Travel Example 2] Face) JOri di nJ ' 9j
ki Askl 14.489 6.22
4 1.49186 57.4 -0.34447 -
7.28882XLO'2 -34.501 2.00
5 -11.66943-146.3
05 1 1.58547 29.9 Distance from screen surface to 1st surface Distance from 4th surface to eye point Field of view ratio 95% f = 70.229 Magnification 0.740x (52/70.229) S F 1
=-0,292 S F 2 = 0.495 (d1+ d, + d,) / f = 0.13781
．． 004 Distance from screen surface to first surface 81,004 4th
Distance from surface to eyepoint 15 Field of view 95% f = 69.061 Magnification 0.743x (52/69.961) S F 1
=-0,408 8F 2 == 0.814 (d, +d2+d,)/f=0.132 Throat pain case 3] Plane PJori 1 13.231 2 -24.387 3-110.535 dlnj 9J 8.203 1.4911s6 57.41.231 1 1.71736 29.3 ki Ar1 -0.275 -1.30316xlO-'-9.80
573 2.47025X10' Scattering Example 4] Surface No r 1 14.678 2 -28.267 3-333.815 dl nJ93 kl A@1? ,6
1.49186 57.4-0.38849-9.0
8487X10"2.153 -9.
041081 1.80518 25.4 Distance from screen surface to first surface 81,004 4th
Distance from surface to eyepoint 15 Field of view 95% f = 67.03 Magnification 0.776x (52/67.03) SF 1
= -0,297 SF 2 = 0.761 (d, + d2 + d3) / f = 0.156 Distance from the screen surface to the first surface 81.004 Distance from the fourth surface to the eye point 15 fields of view Ratio 95% f = 67.314 Magnification 0.772x (52/67.314) S F 1
=-0,316 SF 2 = 0.898 (d, + d2+ d,) / f = 0.160 Example 5] Surface No rl 1 13.944 2 -31.306 3 136.934 dlnJ '11J IJ A@>
7.54g 1.49186 57.4 -0.43
628 -9.28391X10-1.94
-12.31741 1.80518
25.4 Gorge Example 6] Surface No r'1 1 12.472 2 -69.886 3 30.528 4 11.288 dl nj yJ ki A
@(7,2371,4918657,4-0,4902
7-8,40078X10-1.944
-53.616911, closed 51g 25.4 Distance M from screen surface to first surface 81.004 Distance from fourth surface to eye point 15 Field of view 95
% f = 66.927 Magnification 0.777 times (52/66.927) S F 1
=-0,384 SF 2 = 1.246 (d1+ d, + d,) / f = 0.157 Distance from the screen surface to the first surface 81.004 Distance from the fourth surface to the eye point 15 Field of view 95% f = 65.58 Magnification 0.793x (52/65.58) S F 1
=-0,697 S F 2 = 2.173 (d, + d, + d3) / f = 0.155 Arm side 7] 'F6o rh 1 16.589 2 -38.051 3-142.669 dl nJ vjk4 5.989 1.49186 57.4 -0.883
213.144 1 1.5&547 29.9 al -1,0O077X10-' Example 8] Surface Nor1 1 15.091 2 -24.665 3 -31.262 4 20.510 dl nj νjkk 6.814 1. 49186 57.41.820
-6.001981 1.58547 2
9.9 A@i 8°9 & 476 x 104 Distance from screen surface to 1st surface 81.004 4th
Distance from surface to eyepoint 15 Field of view 95% f = 70.066 Magnification 0.742x (52/70.066) S F 1
=-0,393 S F 2 = 0.776 (d + d *” da) / f = O0145 Distance from the screen surface to the first surface 81.004 Distance from the fourth surface to the eye point 15 Field of view rate 95% f = 70.273 Magnification 0.740x (52/70.273) SF 1
= -0,241 SF 2 = 0.208 (d, + d2 + d3) / f = 0.137 Example 9] Surface ri 1 13.991 2 -51.422 3 -86.065 dl nJ vjk・ 6.168 1.491 & 6 57.42.250 1 1.5 & 547 29.9 58.91755i -5,27521x 10-" j Difference example 10] Surface No r'1 1 12.463 2 -73.265 3 - 60.334 4 18.165 dl nJ νj ki6.50
2 1.49186 57.41.8136 1 1.58547 29.9 4.40044 A.

−４，８０９３４Ｘ１０−’ スクリーン面から第１面までの距離　８１．００４第４
面からアイポイントまでの距離　　１５視野率　９５％ ｆ　＝６９．７５７ 倍率　０．７４５倍（５２／６９．７５７）Ｓ　Ｆ　１
　＝−０，５７２ Ｓ　Ｆ　２　＝　０．６５４ （ｄ、＋　ｄ、＋　ｃｉａ）　／　ｆ　＝０．１３５ス
クリ一ン面から第１面までの距離　８１．００４第４面
からアイポイントまでの距離　　１５視野率　９５％ ｆ　＝６８．３４２ 倍率　０．７６１倍（５２／　６８．３４２）Ｓ　Ｆ　
１　＝−０，７０９ Ｓ　Ｆ　２　＝　０．５３７ （ｄ工＋ｄ２＋　ｄ３）　／　ｆ　＝０．１３７洟施例
１１〕 ？６０　　　ｒｉ　　　ｄ、　　　　　ｎｊ　　　　　
９ｊ　　　　ｋｔ　　　　　　　Ａ４ｈ　　　　　　　
　　　　Ａｓｈｌ　１２．８１８８．５１．４９１８６
５７．４０．２２４５５−５．７２６９４Ｘ１０’　−
８，０ＯＬ３８Ｘ１０−２６３．０２２　０ ３６３．０２２　１．５　１．５８５４７　２９．９４
１８　　　　　　　　　　４．０８５４１　　　　　　
　−２．０４６６４ｘｌＯ−’−例１２〕 ＆ｏ　　　ｒｌ　　　　ｄ、　　　　　ｎＪ　　　　　
　　’ＩＩＪ　　　　　　ｋ、　　　　　　　　　　　
　Ａ４１　　　　　　　　　　　　　Ａ＠１１　１５．
１７５　ｇ、５１．４９１８６５７．４０．５１１７４
−６．７１０７Ｘ１（１’　　−４，６１２３４Ｘ１０
−２７３７．５９２　０ ３７３７．５９２　１．５　１．５８５４７　２９．９
４　２５．５６２　　　　　　　　　７．５１１８８　
　　　　　　−２．６０３３２Ｘ１０＝スクリ一ン面か
ら第１面までの距離　７４．６第４面からアイポイント
までの距離　　１５視野率　９５％ ｆ　＝６５．２１１ 倍率　０．７９７倍（５２／６５．２１１）Ｓ　Ｆ　１
　＝−１，５１１ Ｓ　Ｆ　２　＝　１．８００ （ｄ□＋ｄ、＋　ｄ、）　／　ｆ　＝０．１５３スクリ
一ン面から第１面までの距離　７４．６第４面からアイ
ポイントまでの距離　　１５視野率　９５％ ｆ　＝６８．７４６ 倍率　０．７５６倍（５２／６８．７４６）Ｓ　Ｆ　１
　＝−１，０４２ Ｓ　Ｆ　２　＝　１．０７２ （ｄ１＋　ｄ２＋　ｄ、）　／　ｆ　＝０．１４５「発
明の効果」 以上説明したように本発明によれば、２群２枚という簡
単な構成にも拘らず、ペンタプリズムを使用しなくても
倍率が高く、小型で、しかも緒収差図からも明らかなよ
うに性能良好なファインダー光学系が得られる。特に第
ルンズおよび第２レンズに樹脂を用いた場合には非常に
コストが安いという長所がある。-4,80934X10-' Distance from screen surface to 1st surface 81.004 4th
Distance from surface to eyepoint 15 Field of view 95% f = 69.757 Magnification 0.745x (52/69.757) S F 1
=-0,572 S F 2 = 0.654 (d, + d, + cia) / f = 0.135 Distance from the screen surface to the first surface 81.004 Distance from the fourth surface to the eye point 15 Field of view 95% f = 68.342 Magnification 0.761x (52/68.342) S F
1 = -0,709 SF 2 = 0.537 (d + d2 + d3) / f = 0.137 Example 11]? 60rid, nj
9j kt A4h
Ashl 12.8188.51.49186
57.40.22455-5.72694X10'-
8,0OL38X10-263.022 0 363.022 1.5 1.58547 29.94
18 4.08541
-2.04664xlO-'-Example 12] &o rl d, nJ
'IIJ k,
A41 A@11 15.
175 g, 51.4918657.40.51174
-6.7107X1(1' -4,61234X10
-2737.592 0 3737.592 1.5 1.58547 29.9
4 25.562 7.51188
-2.60332X10 = Distance from the screen surface to the first surface 74.6 Distance from the fourth surface to the eye point 15 Field of view 95% f = 65.211 Magnification 0.797x (52/65.211) S F 1
=-1,511 S F 2 = 1.800 (d + d, + d,) / f = 0.153 Distance from the screen surface to the first surface 74.6 Distance from the fourth surface to the eye point 15 Field of view ratio 95% f = 68.746 Magnification 0.756x (52/68.746) SF 1
=-1,042 S F 2 = 1.072 (d1+ d2+ d,) / f = 0.145 "Effect of the invention" As explained above, according to the present invention, even a simple configuration of two elements in two groups can be achieved. However, even without using a pentaprism, it is possible to obtain a finder optical system that has high magnification, is compact, and has good performance as is clear from the aberration diagram. Particularly, when resin is used for the first lens and the second lens, the cost is extremely low.

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

第１図乃至第１２図は、それぞれ本発明の実施例１乃至
実施例１２の光学系の断面図である。 第１３図乃至第２４図は、それぞれ本発明の実施例１乃
至実施例１２のアイリング径φ４のときの諸収差図であ
る。 特許出願人　　　旭光学工業株式会社 代表者　松本　徹 鷺 凹 第 図 回 第１３図 球面収差 止を条件 色収差 倍率色収差 ネ点収差 歪曲収差 ８６一 第１４図 球１１ａ差 正弦条件 色収差 倍率色収差 零点Ｑ差 歪曲ｃＬ差 コマー又亀 第１５図 ！１Ｍ収差 正弦条件 色収差 倍率色ｃＬ差 露点収差 ！１ＩＩＩｔＬ羞 ８７一 第１６図 球箇収差 正弦条件 色収差 倍率色収差 零点収差 歪曲収差 コマＬｌ線 第１７図 ！ｌ箇収差 正弦条件 色ａｍ 倍率色ｃＬ１１ 零点収差 歪曲収差 コマｑ又ｔ 第１８図 ！ｉｌｌ収差 正弦条件 色収差 倍率色ｃＬ！！ 零点収差 歪曲収差 コマ収態 第１９図 １１ｃＬ！１ 正弦条件 色収差 倍率色収差 声点１１Ｎ！！ 歪曲１：Ｌ差 コマ収態 第２０図 球５Ｎα差 正弦条件 色収差 倍率色収差 零点収差 歪曲ＣＬ差 コマ収光 第２１図 ｗａｇｋ 正弦条件 色ａ差 倍率色ｆｆｌ差 非点ｌＸ差 ！ｌ龜ｃＬ差 第２２図 ｍＷａ差 正弦条件 色収差 倍率色ｃＬ整 郭成収差 歪曲収差 コマ明光 第２３図 ！ｔｍ収差 正弦条件 色収差 倍率色収差 ネ点ｌｌｌ差 歪曲ｃＬ差 第２４図 球面（！１！ 正弦条件 色収差 倍率色収差 零点収差 歪曲（１差 コマ収態 手 続 補 正 書 乙、補正の対象 図面 （第１゜ ２回） 補正の内容 別紙のとおり、 第１図。 第２図を補正する。 ／、事件の表示 平成１年特許願第２３３１号 事件との関係1 to 12 are cross-sectional views of optical systems of Examples 1 to 12 of the present invention, respectively. FIGS. 13 to 24 are diagrams of various aberrations when the eye ring diameter is φ4 in Examples 1 to 12 of the present invention, respectively. Patent Applicant Asahi Kogaku Kogyo Co., Ltd. Representative Tetsusa Matsumoto cL difference commer Matakame figure 15! 1M aberration sine condition chromatic aberration magnification color cL difference dew point aberration! 1IIItL Photo87- Fig. 16 Spherical aberration Sine condition Chromatic aberration Magnification Chromatic aberration Zero point aberration Distortion aberration Coma Ll line Fig. 17! l aberration sine condition color am magnification color cL11 zero point aberration distortion aberration coma q or t Figure 18! ill aberration sine condition chromatic aberration magnification color cL! ! Zero point aberration distortion aberration coma convergence Fig. 19 11cL! 1 Sine condition chromatic aberration magnification chromatic aberration voice point 11N! ! Distortion 1: L difference coma convergence Figure 20 Sphere 5N α difference sine condition chromatic aberration magnification chromatic aberration zero point aberration distortion CL difference coma convergence Figure 21 wagk sine condition color a difference magnification color ffl difference astigmatism lX difference! l 龜cL difference Fig. 22 mWa difference sine condition chromatic aberration magnification color cL contouring aberration distortion aberration coma Meiko Fig. 23! tm aberration sine condition chromatic aberration magnification chromatic aberration net point lll difference distortion cL difference Fig. 24 Spherical surface (! 1! Sine condition chromatic aberration magnification chromatic aberration zero point aberration distortion (1 difference coma convergence procedure correction document B, drawings to be corrected (1st ゜ 2 Contents of the amendment As shown in the attached sheet, Figure 1. Figure 2 is amended.

Claims (1)

【特許請求の範囲】 １　一眼レフカメラにおけるファインダースクリーン側
から、正の単レンズから成る第１レンズと、負の単レン
ズから成る第２レンズとから構成され、前記第１及び第
２レンズのシェイプファクターをそれぞれＳＦ１、ＳＦ
２とレ、シェイプファクターＳＦは各レンズのファイン
ダースクリーン側の面の曲率半径をＲ＿Ｓ、アイポイン
ト側の面の曲率半径をＲ＿Ｅとするとき ＳＦ＝（Ｒ＿Ｓ＋Ｒ＿Ｅ）／（Ｒ＿Ｓ−Ｒ＿Ｅ）で定義
するものとし、 （１）−２＜ＳＦ１＜０ （２）０＜ＳＦ２＜３ の各条件を満足することを特徴とするファインダー光学
系。 ２　前記第１レンズおよび前記第２レンズを構成する４
面のうち、少なくとも１面は非球面で構成されることを
特徴とする請求項１記載のファインダー光学系。 ３　前記第１レンズの光軸方向の厚さをｄ＿１、前記第
１レンズと前記第２レンズの光軸上の間隔をｄ＿２、前
記第２レンズの光軸方向の厚さをｄ＿３、ファインダー
光学系の合成焦点距離をｆとしたとき、（３）０．０５
＜（ｄ＿１＋ｄ＿２＋ｄ＿３）／ｆ＜０．３の条件を満
足することを特徴とする請求項１乃至２記載のファイン
ダー光学系。 ４　前記第１レンズはアクリル樹脂、前記第２レンズは
ポリカーボネート樹脂により構成されることを特徴とす
る請求項１乃至３記載のファインダー光学系。[Scope of Claims] 1. From the viewfinder screen side of a single-lens reflex camera, it is composed of a first lens consisting of a positive single lens and a second lens consisting of a negative single lens, and the shape of the first and second lenses is The factors are SF1 and SF, respectively.
2. Shape factor SF is defined as SF=(R_S+R_E)/(R_S-R_E), where the radius of curvature of the surface on the finder screen side of each lens is R_S, and the radius of curvature on the surface on the eye point side is R_E. A finder optical system characterized by satisfying the following conditions: (1) -2<SF1<0 (2) 0<SF2<3. 2 4 constituting the first lens and the second lens
2. The finder optical system according to claim 1, wherein at least one of the surfaces is an aspherical surface. 3. The thickness of the first lens in the optical axis direction is d_1, the distance between the first lens and the second lens on the optical axis is d_2, the thickness of the second lens in the optical axis direction is d_3, and the finder optical system. When the composite focal length of is f, (3) 0.05
3. The finder optical system according to claim 1, wherein the finder optical system satisfies the following condition: <(d_1+d_2+d_3)/f<0.3. 4. The finder optical system according to claim 1, wherein the first lens is made of acrylic resin and the second lens is made of polycarbonate resin.
JP1002331A 1989-01-09 1989-01-09 Viewfinder optical system of a single-lens reflex camera using a pentamirror Expired - Fee Related JPH0758368B2 (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
JP1002331A JPH0758368B2 (en) 1989-01-09 1989-01-09 Viewfinder optical system of a single-lens reflex camera using a pentamirror
GB9000066A GB2227104B (en) 1989-01-09 1990-01-03 Viewfinder
FR9000180A FR2641621B1 (en) 1989-01-09 1990-01-09 OPTICAL SYSTEM FOR USE WITH A SINGLE-LENS REFLEX CAMERA SIGHT
DE19904000448 DE4000448C2 (en) 1989-01-09 1990-01-09 SLR viewfinder with a penta mirror and an optical system
US07/549,987 US5136427A (en) 1989-01-09 1990-07-09 Optical system for use with a viewfinder

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1002331A JPH0758368B2 (en) 1989-01-09 1989-01-09 Viewfinder optical system of a single-lens reflex camera using a pentamirror

Publications (2)

Publication Number Publication Date
JPH02181713A true JPH02181713A (en) 1990-07-16
JPH0758368B2 JPH0758368B2 (en) 1995-06-21

Family

ID=11526331

Family Applications (1)

Application Number Title Priority Date Filing Date
JP1002331A Expired - Fee Related JPH0758368B2 (en) 1989-01-09 1989-01-09 Viewfinder optical system of a single-lens reflex camera using a pentamirror

Country Status (4)

Country Link
JP (1) JPH0758368B2 (en)
DE (1) DE4000448C2 (en)
FR (1) FR2641621B1 (en)
GB (1) GB2227104B (en)

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JP2016126120A (en) * 2014-12-26 2016-07-11 株式会社ニコン Ocular lens, optical device, and method for manufacturing ocular lens

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JP3072157B2 (en) * 1991-09-10 2000-07-31 旭光学工業株式会社 Zoom finder
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GB2282461A (en) * 1991-11-25 1995-04-05 Asahi Optical Co Ltd Variable power view finder

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JPH0241613Y2 (en) * 1979-02-01 1990-11-06

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5754931A (en) * 1980-09-19 1982-04-01 Nippon Kogaku Kk <Nikon> View finder for single-lens reflex camera

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6144502A (en) * 1997-12-24 2000-11-07 Canon Kabushiki Kaisha Viewfinder optical system and optical apparatus having the same
JP2016126120A (en) * 2014-12-26 2016-07-11 株式会社ニコン Ocular lens, optical device, and method for manufacturing ocular lens

Also Published As

Publication number Publication date
DE4000448A1 (en) 1990-07-12
FR2641621A1 (en) 1990-07-13
FR2641621B1 (en) 1993-04-23
DE4000448C2 (en) 1993-12-02
JPH0758368B2 (en) 1995-06-21
GB2227104A (en) 1990-07-18
GB9000066D0 (en) 1990-03-07
GB2227104B (en) 1993-03-31

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