JPH01155313A - Secondary image formation type finder optical system - Google Patents
Secondary image formation type finder optical systemInfo
- Publication number
- JPH01155313A JPH01155313A JP62315549A JP31554987A JPH01155313A JP H01155313 A JPH01155313 A JP H01155313A JP 62315549 A JP62315549 A JP 62315549A JP 31554987 A JP31554987 A JP 31554987A JP H01155313 A JPH01155313 A JP H01155313A
- Authority
- JP
- Japan
- Prior art keywords
- lens
- finder
- relay
- optical system
- image
- 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
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 50
- 230000015572 biosynthetic process Effects 0.000 title abstract 2
- 239000000463 material Substances 0.000 claims abstract description 7
- 238000003384 imaging method Methods 0.000 claims description 14
- 230000014509 gene expression Effects 0.000 description 16
- 230000004075 alteration Effects 0.000 description 11
- 210000001747 pupil Anatomy 0.000 description 6
- 238000010586 diagram Methods 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000004904 shortening Methods 0.000 description 2
- 229910052709 silver Inorganic materials 0.000 description 2
- 239000004332 silver Substances 0.000 description 2
- -1 silver halide Chemical class 0.000 description 2
- 241000600169 Maro Species 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 108091008695 photoreceptors Proteins 0.000 description 1
Landscapes
- Viewfinders (AREA)
- Telescopes (AREA)
- Lenses (AREA)
Abstract
Description
【発明の詳細な説明】
(産業上の利用分野)
本発明は2次結像式ファインダー光学系に関し、特に撮
影レンズとは別個の専用の対物レンズを設けた所定の光
学全長を有する、例えば電子スチルカメラやビデオカメ
ラ等に好適な2次結像式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 secondary imaging type finder optical system, and in particular to a secondary imaging type finder optical system having a predetermined optical total length provided with a dedicated objective lens separate from a photographing lens. The present invention relates to a secondary imaging type finder optical system suitable for still cameras, video cameras, etc.
(従来の技術)
最近、映像情報を小型のフロッピーディスクに磁気記録
する電子スチルカメラに関する撮影系が種々提案されて
いる。このうち特にファインダー光学系は種々のタイプ
のものが多く提案されている。(Prior Art) Recently, various imaging systems have been proposed for electronic still cameras that magnetically record video information on small floppy disks. Among these, many different types of finder optical systems have been proposed.
電子スチルカメラはフロッピーディスクをカメラ本体内
にどのように配置するかによって、カメラ全体の形態が
従来の銀塩感光体用のカメラ等と比べて大きく異ってく
る。The overall shape of the electronic still camera differs greatly from that of conventional cameras using silver halide photoreceptors, depending on how the floppy disk is placed within the camera body.
例えば、フロッピーディスクを撮影レンズの光軸と平行
な面内に収納する場合は記録再生一体型の動画ビデオカ
メラ等のように光軸方向に長い形態となってくる。For example, when a floppy disk is housed in a plane parallel to the optical axis of a photographic lens, it is elongated in the optical axis direction, such as in a recording/playback integrated moving video camera.
従来より銀塩カメラ用の外部ファインダー光学系として
好適であった、所謂逆ガリレオ式ファインダー光学系や
正立正像用プリズムを用いた1次結像式の実像ファイン
ダー光学系は電子スチルカメラ等においては光学全長が
短かすぎて、例えば次のような問題点があった。The so-called inverted Galilean finder optical system and the primary image-forming real image finder optical system using an erecting image prism, which have traditionally been suitable as external finder optical systems for silver halide cameras, are not suitable for electronic still cameras, etc. The total optical length was too short, which caused the following problems.
即ち、充分な長さのアイポイントを確保する為にファイ
ンダー光学系の接眼レンズをカメラ後面近傍に配置した
場合、ファインダー光学系の光学全長が短い為にファイ
ンダー光学系の対物レンズの前面はカメラ前面より、か
なり奥まった位置に配されるようになる。この為、ケラ
レのないファインダー光束を確保するにはカメラ前面の
開口部を大きくしなければならず、撮影レンズの光軸と
ファインダー光学系の光軸が互いに離れてしまいファイ
ンダーバララックスが大きくなってくる等の問題点があ
った。In other words, if the eyepiece of the finder optical system is placed near the rear of the camera in order to ensure an eyepoint of sufficient length, the front of the objective lens of the finder optical system will be placed in front of the camera because the overall optical length of the finder optical system is short. It will now be placed in a much more recessed position. Therefore, in order to ensure a viewfinder light flux without vignetting, the aperture on the front of the camera must be made large, and the optical axis of the photographic lens and the optical axis of the viewfinder optical system are separated from each other, increasing finder balax. There were problems such as coming.
一方、従来のビデオカメラ等に用いられている2次結像
式ファインダー光学系は一般に光軸方向に長くなりすぎ
、例えば電子スチルカメラにはあまり適していない。On the other hand, secondary imaging type finder optical systems used in conventional video cameras and the like are generally too long in the optical axis direction and are not well suited for, for example, electronic still cameras.
(発明が解決しようとする問題点)
本発明は対物レンズによって形成されたファインダー像
を、更にリレーレンズ系等により再結像させた正立正像
のファインダー像を接眼レンズで観察する、所謂2結像
式ファインダー光学系において、各レンズ群のレンズ構
成及び屈折力を適切に配置することにより、所定の光学
全長を有し、しかも高い光学性能を有したファインダー
像の観察が可能な電子スチルカメラやビデオカメラ等に
好適な2次結像式ファインダー光学系の提供を目的とす
る。(Problems to be Solved by the Invention) The present invention is a so-called two-focus method in which a finder image formed by an objective lens is further re-imaged by a relay lens system, and an erect normal finder image is observed with an eyepiece. In an image-type finder optical system, by appropriately arranging the lens configuration and refractive power of each lens group, electronic still cameras and electronic still cameras are capable of observing a finder image with a predetermined total optical length and high optical performance. The object of the present invention is to provide a secondary imaging type finder optical system suitable for video cameras and the like.
(問題点を解決するための手段)
曲率の強いレンズ面を向き合わせて配置した2枚の正レ
ンズより成る対物レンズにより第1次ピント面上に形成
したファインダー像を、負レンズと正レンズを貼り合わ
せた接合レンズより成るリレーレンズと、曲率の強いレ
ンズ面を物体側に向けた正レンズより成るフィールドレ
ンズとを介して第2次ピント面上に正立正像のファイン
ダー像を形成し、該正立正像のファインダー像を曲率の
強いレンズ面を向き合わせて配置した2枚の正レンズよ
り成る接眼レンズにより観察する際、前記対物レンズ、
リレーレンズ、フィールドレンズ、そして接眼レンズの
焦点距離を順にfT、fRlfF、fEとし、前記リレ
ーレンズの負レンズと正レンズの材質の屈折率を各々N
N、NP、前記リレーレンズの負レンズと正レンズの材
質のアツベ数を各々υN、νP、前記リレーレンズの接
合レンズの貼り合わせレンズ面の曲率半径をRAとした
とき
1.0< fR/fT <1.8 −−−−−(+
)1、0< fF/fE <1.7 −−−−−−
(2)0、3< l RA l /f R<0.6 −
−−−−(3)0.07< NN−NP −
−−−−−−−−−−(4)25 〈 シP−シN
−−−−−−−−−(5)なる条件を満足するこ
とである。(Means for solving the problem) The finder image formed on the primary focus plane by an objective lens consisting of two positive lenses arranged with their lens surfaces with strong curvature facing each other, is An erect normal finder image is formed on the secondary focus plane through a relay lens made of bonded cemented lenses and a field lens made of a positive lens with the lens surface with strong curvature facing the object side. When observing a finder image of an erect positive image with an eyepiece consisting of two positive lenses arranged with lens surfaces with strong curvature facing each other, the objective lens,
The focal lengths of the relay lens, field lens, and eyepiece lens are fT, fRlfF, and fE in order, and the refractive index of the material of the negative lens and positive lens of the relay lens is N, respectively.
N, NP, the Atsube numbers of the materials of the negative and positive lenses of the relay lens are respectively υN and νP, and the radius of curvature of the bonded lens surface of the cemented lens of the relay lens is RA, 1.0< fR/fT <1.8 −−−−−(+
)1, 0< fF/fE <1.7 --------
(2) 0, 3< l RA l /f R<0.6 −
---- (3) 0.07< NN-NP -
−−−−−−−−−−(4)25 < shiP−shiN
--------------(5) is to be satisfied.
(実施例)
第1図〜第3図は各々本発明の数値実施例1〜3のファ
インダー光学系を展開した概略図である。同図において
Tは対物レンズであり、曲率の強いレンズ面を向き合わ
せて配置した2枚の正レンズより成っている。Rはリレ
ーレンズであり、負レンズと正レンズを貼り合わせた接
合レンズより成っている。Fはフィールドレンズであり
、物体側に凸面を向けた1枚の正レンズより成っている
。Eは接眼レンズであり、曲率の強いレンズ面を向き合
わせて配置した2枚の正レンズより成っている。(Example) FIGS. 1 to 3 are schematic diagrams in which finder optical systems of numerical examples 1 to 3 of the present invention are developed, respectively. In the figure, T is an objective lens, which consists of two positive lenses arranged with their lens surfaces with strong curvature facing each other. R is a relay lens, which is made of a cemented lens made by bonding a negative lens and a positive lens. F is a field lens, which consists of one positive lens with a convex surface facing the object side. Reference numeral E denotes an eyepiece, which consists of two positive lenses arranged with their lens surfaces with strong curvature facing each other.
本実施例における2次結像式ファインダー光学系は、ま
ず対物レンズTにより第1ピント面Pに形成した第1の
ファインダー像をリレーレンズRとフィールドレンズF
により第2ピント面Q上に、正立正像の第2のファイン
ダー像を形成している。そして、第2次ピント面Q上に
形成した正立正像の第2のファインダー像を接眼レンズ
Eにより観察するようにしている。The secondary imaging type finder optical system in this embodiment first focuses a first finder image formed on a first focus plane P by an objective lens T through a relay lens R and a field lens F.
As a result, a second finder image of an erect normal image is formed on the second focus plane Q. A second finder image of an erect image formed on the secondary focus plane Q is then observed through the eyepiece E.
このような構成において、各レンズ群のレンズ構成及び
光学的語数値を前述の条件式(1)〜(5)の如く設定
することにより高い光学性能のファインダー像の観察を
可能としている。In such a configuration, by setting the lens configuration and optical word value of each lens group as in the above-mentioned conditional expressions (1) to (5), it is possible to observe a finder image with high optical performance.
特にリレーレンズのレンズ構成を条件式(3)〜(5)
を満足させるように構成すると共に対物レンズTと接眼
し、ンズEを各々曲率の強いレンズ面を互いに向い合わ
せた2枚の正レンズより構成することにより、各レンズ
群自体で諸収差を良好に打ち消し合いバランスの良い収
差補正を達成している。In particular, the lens configuration of the relay lens is determined by conditional expressions (3) to (5).
By constructing the lens E to satisfy the following, and by constructing the lens E with two positive lenses facing each other with lens surfaces with strong curvature, each lens group itself can suppress various aberrations well. A well-balanced aberration correction is achieved by canceling each other out.
次に前述の各条件式の技術的意味について説明する。Next, the technical meaning of each of the above conditional expressions will be explained.
条件式(1)は本発明で最も重要なるリレーレンズと対
物レンズの屈折力配置に関するものである。今、撮影レ
ンズの焦点距離とファインダー視野率が一定の場合、対
物レンズの合成焦点距離fTが大きくなる程、ファイン
ダー倍率は大きくできるが、−成語像面での大きさが大
きくなるので、リレーレンズとフィールドレンズより成
る2次結像系での収差補正が困難となる。一方、2次結
像系は結像倍率が等倍の時に光学全長が、略4fRと最
も短くなり、リレーレンズの焦点距離が短い程、光学全
長の短縮には有利であるが、収差補正が困難となる。Conditional expression (1) relates to the refractive power arrangement of the relay lens and objective lens, which is most important in the present invention. Now, if the focal length of the photographing lens and the viewfinder field of view are constant, the viewfinder magnification can be increased as the combined focal length fT of the objective lens becomes larger. It becomes difficult to correct aberrations in a secondary imaging system consisting of a field lens and a field lens. On the other hand, the total optical length of the secondary imaging system is the shortest at approximately 4fR when the imaging magnification is equal to 1x, and the shorter the focal length of the relay lens, the more advantageous it is in shortening the total optical length, but it is difficult to correct aberrations. It becomes difficult.
以上のような理由を考慮して本発明においては対物レン
ズとリレーレンズの焦点路@fR/fTの比が条件式(
1)を満足する様に設定している。Considering the above reasons, in the present invention, the ratio of the focal path @fR/fT of the objective lens and the relay lens is determined by the conditional expression (
1) is set to satisfy.
条件式(1)の下限値を越えると、ファインダー倍率と
光学全長の短縮化には有利であるが、ペッツバール像面
の補正が困難となり、一方、上限値を越えると収差補正
には有利であるが、光学全長が長くなり好ましくない。If the lower limit of conditional expression (1) is exceeded, it is advantageous in shortening the finder magnification and the total optical length, but it becomes difficult to correct the Petzval image plane, while on the other hand, if the upper limit is exceeded, it is advantageous in correcting aberrations. However, the total optical length becomes longer, which is not preferable.
条件式(2)は主にリレーレンズの径を小型化する為の
もので、本発明では観察瞳の中心を通る軸外瞳光束が、
リレーレンズのほぼ中心を通る様に、フィールドレンズ
と接眼レンズの焦点距離を設定している。これによりリ
レーレンズの屈折力を強めても、レンズ周辺で急激に屈
折される光束を回避できる為に、観察瞳全域にわたフて
良好な性能が保証される。Conditional expression (2) is mainly used to reduce the diameter of the relay lens, and in the present invention, the off-axis pupil light flux passing through the center of the observation pupil is
The focal lengths of the field lens and eyepiece are set so that the beam passes approximately through the center of the relay lens. As a result, even if the refractive power of the relay lens is strengthened, it is possible to avoid a light beam that is sharply refracted around the lens, thereby ensuring good performance across the entire viewing pupil.
条件式(2)の上限値を越えるとリレーレンズの径が大
きくなると共に接眼レンズの径も大きくなり、逆に条件
式(2)の下限値を越えるとリレーレンズの径が大きく
なると共にフィールドレンズで発生する像面湾曲が補正
しえなくなる。When the upper limit of conditional expression (2) is exceeded, the diameter of the relay lens becomes larger and the diameter of the eyepiece lens also becomes larger. Conversely, when the lower limit of conditional expression (2) is exceeded, the diameter of the relay lens becomes larger and the diameter of the field lens increases. It becomes impossible to correct the field curvature that occurs.
条件式(3)はリレーレンズの接合レンズ面の曲率半径
に関し、上限値を越えると像面湾曲の補正が困難となり
、逆に下限値を越えると2次結像面上での球面収差が補
正過剰となる。Conditional expression (3) relates to the radius of curvature of the cemented lens surface of the relay lens; if the upper limit is exceeded, it becomes difficult to correct field curvature, and conversely, if the lower limit is exceeded, spherical aberration on the secondary imaging surface is corrected. becomes excessive.
条件式(4) 、 (5)はリレーレンズを構成する負
レンズと正レンズの硝材の屈折率とアツベ数に関し、主
に条件式(4)は像面湾曲を良好に補正しうる為の屈折
率差に関し、条件式(5)は主に軸上色収差を補正する
為のアツベ数差に関するものである。Conditional expressions (4) and (5) are related to the refractive index and Atsube number of the glass materials of the negative and positive lenses that make up the relay lens, and conditional expression (4) is mainly concerned with the refraction that can satisfactorily correct field curvature. Regarding the index difference, conditional expression (5) mainly relates to the Abbe number difference for correcting longitudinal chromatic aberration.
条件式(4)を外れると画面周辺にかけての像面湾曲が
大きくなり、又、条件式(5)を外れると色収差が増大
し、いずれも良好なるファインダー像を得るのが難しく
なってくる。If conditional expression (4) is not satisfied, the curvature of field toward the periphery of the screen becomes large, and if conditional expression (5) is not satisfied, chromatic aberration increases, and in both cases it becomes difficult to obtain a good finder image.
尚、本実施例のおいて対物レンズ、フィートレンズ、そ
して接眼レンズを構成している単一レンズのうち任意の
単一レンズを正レンズと負レンズを貼り合わせた接合レ
ンズで構成しても良い。これによれば、より良好なる色
収差等の諸収差を補正した高い光学性能を有したファイ
ンダー光学系を達成することができる。Incidentally, in this embodiment, any single lens among the single lenses constituting the objective lens, foot lens, and eyepiece lens may be composed of a cemented lens made by bonding a positive lens and a negative lens. . According to this, it is possible to achieve a finder optical system having high optical performance in which various aberrations such as chromatic aberration are better corrected.
第1図〜第3図に示す実施例は各光学要素を展開した場
合を示しているが、各光学要素間にミラー等を配置して
光路を折り曲げて構成しても良い。Although the embodiments shown in FIGS. 1 to 3 show the case where each optical element is expanded, a mirror or the like may be arranged between each optical element to bend the optical path.
次に本発明の数値実施例を示す。数値実施例においてR
iは物体側より順に第1番目のレンズ面の曲率半径、D
iは物体側より第i番目のレンズ厚及び空気間隔、Ni
とviは各々物体側より順に第i番目のレンズのガラス
の屈折率とアツベ数である。Next, numerical examples of the present invention will be shown. In numerical examples R
i is the radius of curvature of the first lens surface from the object side, D
i is the i-th lens thickness and air distance from the object side, Ni
and vi are the refractive index and Abbe number of the glass of the i-th lens, respectively, in order from the object side.
又、前述の各条件式と数値実施例における語数値との関
係を表−1に示す。Furthermore, Table 1 shows the relationship between each of the above-mentioned conditional expressions and the word values in the numerical examples.
数値実施例1
射出瞳径 φ3 最大射出角 tanθ= 0.17
R1−33,14D 1m2.00 N 1=1.4
9171 v ]−57,4R2−−9,63D 2
−9.43
R3−7,79D 3−4.28 N 2−1.49
17112−57.4R4−ω D 4嘗31.
40
R5−25,8505−0,72N 3−1.8466
6シ3寥23.9R6= 7.24 06−2.43
N 4=1.77250 v 4−49.6R7−
−22,4407−29,00
R8= 10.62 D8−3.20 85−1.
49171 v 5−57.4R9−oo D
9−24.86RIO−oo DIO−1−50
86−1,49171v 6−57.4R11−−20
,00Dll−0,15R12冒 20.00
Di2− 1.50 N 7−1.4917
1 ν 7−57.4R13−c。Numerical Example 1 Exit pupil diameter φ3 Maximum exit angle tanθ= 0.17
R1-33,14D 1m2.00 N 1=1.4
9171 v ]-57,4R2--9,63D 2
-9.43 R3-7,79D 3-4.28 N 2-1.49
17112-57.4R4-ω D 4嘗31.
40 R5-25,8505-0,72N 3-1.8466
6shi 3ba 23.9R6= 7.24 06-2.43
N 4=1.77250 v 4-49.6R7-
-22,4407-29,00 R8= 10.62 D8-3.20 85-1.
49171 v 5-57.4R9-oo D
9-24.86RIO-oo DIO-1-50
86-1,49171v 6-57.4R11--20
,00Dll-0,15R12 20.00
Di2- 1.50 N 7-1.4917
1 ν 7-57.4R13-c.
尚、アイポイントはR13頂点より16ミリ後方に設定
されている。Note that the eye point is set 16 mm behind the R13 apex.
fT −11,35、fR−18,0、fF −21,
61、fE −20,37数値実施例2
射出瞳径 φ3 最大射出角 tanθ= 0.17
R1−oo D l= 1.80 N
1−1.77250 ν 1−49.6R2−−1
2,4402−9,60
R3−7,85D 3−2.80 N 2−1.49
171υ2−57.4R4−148,4104−28,
89
R5−17,8505−0,80N 3−1.8466
6シ3−23.9R6−7,27D 6−2.60
N 4−1.71300シ4−53.887−−18.
74 D 7−25.07R8−11,0−9D 8
−2.40 N 5−1.49171シ5−57.4
R9−(X) 09書22.01RIO富 1
44.93 010− 1.80 N 6
麿1.49171 ν 6−57.4R11雪 −2
0,70Dll−0,15R12= 20.70
Di2−1.80 87−1.49171 v 7−5
7.4R13−−144,93
fT −11,34、fR〜15.39 、 fF −
22,56、fE −18,61数値実施例3
射出瞳径 φ3 最大射出角 tanθ= 0.17
R1=5458.52 D I= 2.60 N
1=1.49171 Z/ l−57,4R2−−8
,01D 2− 9.09R3−8,0103−2,
60N 2−1.49171シ2−57.48 4−5
458.52 D 4−32.92R5−17,
7205−0,80N 3−1.84666シ3−23
.986− 7.24 06−2.60 N 4−1
.69680ν4−55.5R7−−20,84D 7
−27.93R8−12,13D 8−2.40 N
5−1.49171 シ5−57.48 9=
oo D 9=22.07RIO−389,
49010−1,80N 6■1.49171シロ霧5
7.4R11−−19,15Dll−0,15R12−
19,15Di2− 1.80 N 7冒1.
49171 ν 7−57.4R13−389,49
fT −11,30、fR−17,0、fF −24,
68、fE −18,66表−1
(発明の効果)
以上のように本発明によればファインダー光学系として
2次結像式を採用する際、前述の如く各光学要素を設定
し、特にリレーレンズや対物レンズ等の屈折力を適切に
設定することにより、所定の光学全長を有した高い光学
性能を有したファインダー像の観察が可能な簡易な構成
の2次結像式ファインダー光学系を達成することができ
る。fT -11,35, fR-18,0, fF -21,
61, fE -20,37 Numerical Example 2 Exit pupil diameter φ3 Maximum exit angle tanθ= 0.17
R1-oo D l= 1.80 N
1-1.77250 ν 1-49.6R2--1
2,4402-9,60 R3-7,85D 3-2.80 N 2-1.49
171υ2-57.4R4-148, 4104-28,
89 R5-17,8505-0,80N 3-1.8466
6shi 3-23.9R6-7, 27D 6-2.60
N 4-1.71300shi 4-53.887--18.
74 D 7-25.07R8-11,0-9D 8
-2.40 N 5-1.49171 5-57.4
R9-(X) 09 book 22.01 RIO wealth 1
44.93 010- 1.80 N 6
Maro 1.49171 ν 6-57.4R11 Snow -2
0,70Dll-0,15R12=20.70
Di2-1.80 87-1.49171 v 7-5
7.4R13--144,93 fT -11,34, fR ~ 15.39, fF -
22,56, fE -18,61 Numerical Example 3 Exit pupil diameter φ3 Maximum exit angle tanθ= 0.17
R1=5458.52 DI=2.60N
1=1.49171 Z/ l-57,4R2--8
,01D 2- 9.09R3-8,0103-2,
60N 2-1.49171 2-57.48 4-5
458.52 D 4-32.92R5-17,
7205-0,80N 3-1.84666shi3-23
.. 986- 7.24 06-2.60 N 4-1
.. 69680ν4-55.5R7--20,84D 7
-27.93R8-12,13D 8-2.40 N
5-1.49171 5-57.48 9=
oo D9=22.07RIO-389,
49010-1,80N 6■1.49171 White fog 5
7.4R11--19,15Dll-0,15R12-
19,15Di2- 1.80 N 7 1.
49171 ν 7-57.4R13-389,49 fT -11,30, fR-17,0, fF -24,
68, fE-18, 66 Table-1 (Effects of the Invention) As described above, according to the present invention, when employing the secondary imaging type as the finder optical system, each optical element is set as described above, and especially the relay By appropriately setting the refractive power of lenses, objective lenses, etc., we have achieved a secondary imaging type finder optical system with a simple configuration that allows observation of a finder image with a predetermined optical total length and high optical performance. can do.
第1図〜第3図は各々本発明の数値実施例1〜3のレン
ズ断面図、第4図〜第6図は各々本発明の数値実施例1
〜3の物体距離3mにおける諸収差図である。
図中、Tは対物レンズ、Rはリレーレンズ、Fはフィー
ルドレンズ、Eは接眼レンズ、ΔMはメリディオナル像
面、ΔSはサジタル像面である。
特許出願人 キャノン株式会社
・−1−・−」
図
第 2
1)IL12L)3 04 D5D6
F E
第 4riU
日1ト佳φ3 プ巳an&=0.17
tan9:0.17第 5
図
璃
8!伸ψ3i。
2op 2op −2pp
揮115JIK廠 プ1
6図
Aθ司、17tMnθ=0.17
鳴1 to 3 are cross-sectional views of lenses of numerical embodiments 1 to 3 of the present invention, and FIGS. 4 to 6 are lens sectional views of numerical embodiment 1 of the present invention, respectively.
3 is a diagram showing various aberrations at an object distance of 3 m. In the figure, T is an objective lens, R is a relay lens, F is a field lens, E is an eyepiece lens, ΔM is a meridional image surface, and ΔS is a sagittal image surface. Patent applicant: Canon Co., Ltd. -1--" Figure 2 1) IL12L) 3 04 D5D6
F E 4th riU Day 1 Toka φ3 Pumi an&=0.17
tan9: 0.17th 5th
Zuli 8! Elongation ψ3i. 2op 2op -2pp Ki115JIK廠 Pu1 6Aθ Tsukasa, 17tMnθ=0.17 Sound
Claims (1)
ンズより成る対物レンズにより第1次ピント面上に形成
したファインダー像を、負レンズと正レンズを貼り合わ
せた接合レンズより成るリレーレンズと、曲率の強いレ
ンズ面を物体側に向けた正レンズより成るフィールドレ
ンズとを介して第2次ピント面上に正立正像のファイン
ダー像を形成し、該正立正像のファインダー像を曲率の
強いレンズ面を向き合わせて配置した2枚の正レンズよ
り成る接眼レンズにより観察する際、前記対物レンズ、
リレーレンズ、フィールドレンズ、そして接眼レンズの
焦点距離を順にfT、fR、fF、fEとし、前記リレ
ーレンズの負レンズと正レンズの材質の屈折率を各々N
N、NP、前記リレーレンズの負レンズと正レンズの材
質のアッベ数を各々νN、νP、前記リレーレンズの接
合レンズの貼り合わせレンズ面の曲率半径をRAとした
とき 1.0<fR/fT<1.8 1.0<fF/fE<1.7 0.3<|RA|/fR<0.6 0.07<NN−NP 25<νP−νN なる条件を満足することを特徴とする2次結像式ファイ
ンダー光学系。[Claims] A finder image formed on the primary focus plane by an objective lens consisting of two positive lenses arranged with lens surfaces with strong curvature facing each other, is created by bonding a negative lens and a positive lens together. A finder image of an erect normal image is formed on the secondary focus plane through a relay lens consisting of a lens and a field lens consisting of a positive lens with a lens surface with a strong curvature facing the object side. When observing a finder image with an eyepiece consisting of two positive lenses arranged with lens surfaces with strong curvature facing each other, the objective lens,
The focal lengths of the relay lens, field lens, and eyepiece lens are fT, fR, fF, and fE in order, and the refractive index of the material of the negative lens and positive lens of the relay lens is N, respectively.
N, NP, the Abbe numbers of the materials of the negative and positive lenses of the relay lens are νN and νP, respectively, and the radius of curvature of the bonded lens surface of the cemented lens of the relay lens is RA, 1.0<fR/fT <1.8 1.0<fF/fE<1.7 0.3<|RA|/fR<0.6 0.07<NN-NP 25<νP-νN It is characterized by satisfying the following conditions. Secondary imaging finder optical system.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP62315549A JP2510138B2 (en) | 1987-12-14 | 1987-12-14 | Secondary imaging finder optical system |
US07/280,584 US4964686A (en) | 1987-12-14 | 1988-12-06 | Finder optical device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP62315549A JP2510138B2 (en) | 1987-12-14 | 1987-12-14 | Secondary imaging finder optical system |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH01155313A true JPH01155313A (en) | 1989-06-19 |
JP2510138B2 JP2510138B2 (en) | 1996-06-26 |
Family
ID=18066680
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP62315549A Expired - Lifetime JP2510138B2 (en) | 1987-12-14 | 1987-12-14 | Secondary imaging finder optical system |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP2510138B2 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH03140910A (en) * | 1989-10-27 | 1991-06-14 | Olympus Optical Co Ltd | Optical system |
JPH03150517A (en) * | 1989-11-08 | 1991-06-26 | Canon Inc | Real image type variable magnification finder optical system |
JPH08114742A (en) * | 1994-08-23 | 1996-05-07 | Asahi Optical Co Ltd | Optical system for composite camera |
JP2006217827A (en) * | 2005-02-08 | 2006-08-24 | Agritecno Yazaki Co Ltd | Chemical applicator |
-
1987
- 1987-12-14 JP JP62315549A patent/JP2510138B2/en not_active Expired - Lifetime
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH03140910A (en) * | 1989-10-27 | 1991-06-14 | Olympus Optical Co Ltd | Optical system |
JPH03150517A (en) * | 1989-11-08 | 1991-06-26 | Canon Inc | Real image type variable magnification finder optical system |
JPH08114742A (en) * | 1994-08-23 | 1996-05-07 | Asahi Optical Co Ltd | Optical system for composite camera |
JP2006217827A (en) * | 2005-02-08 | 2006-08-24 | Agritecno Yazaki Co Ltd | Chemical applicator |
Also Published As
Publication number | Publication date |
---|---|
JP2510138B2 (en) | 1996-06-26 |
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