JPH0792386A - Real image system variable power finder - Google Patents
Real image system variable power finderInfo
- Publication number
- JPH0792386A JPH0792386A JP23986093A JP23986093A JPH0792386A JP H0792386 A JPH0792386 A JP H0792386A JP 23986093 A JP23986093 A JP 23986093A JP 23986093 A JP23986093 A JP 23986093A JP H0792386 A JPH0792386 A JP H0792386A
- Authority
- JP
- Japan
- Prior art keywords
- lens
- lens group
- finder
- real image
- variable power
- 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.)
- Pending
Links
Landscapes
- Viewfinders (AREA)
- Lenses (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、写真用カメラまたはビ
デオカメラ等に用いられるファインダに係り、特に実像
式変倍ファインダに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a finder used in a photographic camera, a video camera or the like, and more particularly to a real image type variable magnification finder.
【０００２】[0002]
【従来の技術】従来、撮影レンズとは別体のファインダ
光学系を要する場合には、コストの点で有利なため、虚
像式ファインダを用いるのが一般的であり、ズームレン
ズを搭載したカメラの場合も、当初は虚像式の変倍ファ
インダが用いられていた。2. Description of the Related Art Conventionally, when a finder optical system separate from a taking lens is required, it is common to use a virtual image finder because it is advantageous in terms of cost. In such a case, a virtual image type variable magnification finder was initially used.
【０００３】しかし、虚像式ファインダは、前玉径が大
きくなるという欠点があり、特に、変倍ファインダとし
て、その変倍比を大きくしていくと、前玉径が非常に大
きくなってしまう。However, the virtual image finder has a drawback that the diameter of the front lens becomes large. Especially, as the magnification finder is increased, the diameter of the front lens becomes very large.
【０００４】これに対し、実像式ファインダの場合に
は、虚像式の場合に比べて、入射瞳位置を前方にするこ
とができるため前玉径が小さくなり、また、視野枠の鮮
明さでも有利であるので、近年特に変倍ファインダとし
ては、実像式がよく用いられるようになった。On the other hand, in the case of the real image type finder, the entrance pupil position can be moved forward, so that the diameter of the front lens becomes smaller than that in the case of the virtual image type finder and the sharpness of the field frame is also advantageous. Therefore, in recent years, the real image type has come to be often used especially as a variable magnification finder.
【０００５】[0005]
【発明が解決しようとする課題】しかし、実像式ファイ
ンダは、対物レンズを用いて一旦結像させてから、その
像を接眼レンズを用いて観察するために、虚像式ファイ
ンダに比べて構成枚数が多くなりがちである。特に、変
倍比が２倍を越えるような高変倍実像ファインダの場合
には、構成が複雑になりコスト高につながりやすい。However, the real image type finder has a smaller number of constituent elements than the virtual image type finder, since the image is once formed using the objective lens and then the image is observed using the eyepiece lens. It tends to be many. In particular, in the case of a high-magnification real image finder having a variable power ratio of more than 2, the structure becomes complicated and the cost tends to increase.
【０００６】このような問題を解決した、枚数の少ない
実像式ファインダとしては、特開平2-109009号公報、特
開平3-233420号公報に記載のものがある。しかしなが
ら、特開平2-109009号公報に記載のものは、変倍時に第
１レンズを移動させるもので、構造的に、ファインダ内
にホコリ等が入りやすく好ましくない。また、特開平3-
233420号公報に記載のものは、その実施例をみると、変
倍比が２倍に達しておらず、やや物足りないものであ
る。As a real image type finder which solves such a problem and has a small number of sheets, there are those disclosed in JP-A-2-09009 and JP-A-3-233420. However, the one described in Japanese Patent Laid-Open No. 2-109009 moves the first lens during zooming, and is structurally unfavorable because dust and the like may enter the finder. In addition, JP-A-3-
In the example described in Japanese Patent No. 233420, the zoom ratio does not reach twice, and the example is somewhat unsatisfactory.
【０００７】本発明は、上記課題を解決するためになさ
れたものである。すなわち、2.5倍以上の変倍比を有し
ながら、見え味が良く、かつコンパクトな実像式ファイ
ンダを低コストで提供することを目的としたものであ
る。The present invention has been made to solve the above problems. That is, the object is to provide a real image type finder which has a zoom ratio of 2.5 times or more, is good in appearance, and is compact, at low cost.
【０００８】[0008]
【課題を解決するための手段】上記目的は、物体側より
順に、物体側に凸面を向けた、非球面を有する１枚の負
メニスカスレンズからなる第１レンズ群、１枚の両凸レ
ンズからなる第２レンズ群、１枚の負レンズからなる第
３レンズ群、１枚の正レンズからなる第４レンズ群を有
し、前記第２レンズ群と第３レンズ群が移動することに
より変倍を行う対物レンズ部と、接眼レンズとから構成
されることを特徴とする実像式変倍ファインダによって
達成される。The above object consists of a first lens group consisting of one negative meniscus lens having an aspherical surface with a convex surface facing the object side, and one biconvex lens in order from the object side. It has a second lens group, a third lens group consisting of one negative lens, and a fourth lens group consisting of one positive lens, and zooms by changing the second lens group and the third lens group. It is achieved by a real image type variable power viewfinder characterized by comprising an objective lens section and an eyepiece lens.
【０００９】また、上記目的は、物体側より順に、物体
側に凸面を向けた、非球面を有する１枚の負メニスカス
レンズからなる第１レンズ群、１枚の両凸レンズからな
る第２レンズ群、１枚の負レンズからなる第３レンズ
群、１枚の正レンズからなる第４レンズ群を有し、前記
第４レンズ群を、像を正立させるためのプリズムと一体
とし、前記第２レンズ群と第３レンズ群が移動すること
により変倍を行う対物レンズ部と、接眼レンズとから構
成されることを特徴とする実像式変倍ファインダによっ
て達成されるものである。Further, the above-mentioned object is, in order from the object side, a first lens group consisting of one negative meniscus lens having an aspherical surface with a convex surface facing the object side, and a second lens group consisting of one biconvex lens. A third lens group consisting of one negative lens, and a fourth lens group consisting of one positive lens, wherein the fourth lens group is integrated with a prism for erecting an image; This is achieved by a real-image type variable power viewfinder characterized by comprising an eyepiece and an objective lens unit that performs zooming by moving the lens group and the third lens group.
【００１０】また、この発明のファインダはｆ2を第２
レンズの焦点距離、ｆWを広角端における対物レンズ部
の焦点距離とするとき、以下の条件式を満足することが
望ましい。Further, the finder of the present invention sets f 2 to the second
When the focal length of the lens, f W, is the focal length of the objective lens section at the wide-angle end, it is desirable to satisfy the following conditional expression.
【００１１】 1.4＜ｆ2/ｆW＜2.1 ・・・・・ 1.4 <f 2 / f W <2.1
【００１２】[0012]
【作用】本発明のファインダにおいては、カメラに組み
込んだ時のレンズ全長をできるだけ短くするために、可
動部分と視野枠との間に像を正立させるための反射面を
配置している。そのためのバックフォーカスを確保する
ために、第１レンズ群を負群としており、強い負の歪曲
が発生しやすくなっている。これを補正するために、第
１レンズ群に、軸外に行くにしたがって屈折力が弱くな
るような非球面を用いており、比較的屈折力の強い第１
レンズ群を１枚で構成している。In the viewfinder of the present invention, the reflecting surface for erecting the image is arranged between the movable portion and the field frame in order to shorten the total lens length when incorporated in the camera. In order to secure a back focus for that purpose, the first lens group is a negative group, and strong negative distortion is likely to occur. In order to correct this, the first lens group uses an aspherical surface whose refracting power becomes weaker toward the off-axis.
A single lens unit is used.
【００１３】また、本発明のファンダは、第２レンズ群
の移動により変倍を行い、第３群の移動により、変倍に
伴う像面移動を補正している。第３レンズ群の移動は、
ほとんど変倍作用に寄与しないため、像面移動を補正す
るだけの弱い屈折力を有していればよいのだが、第２レ
ンズ群は変倍作用に大きく寄与しているので屈折力が強
くなる。本発明では、広角端と望遠端の中間付近で、第
２レンズ群の結像倍率を−１倍となるようにし、さら
に、第２レンズを両凸レンズとして、各面の屈折力を物
体側と像側で適当に配分することにより、第２レンズ群
の各面による諸収差の発生をできるだけ抑え、第２レン
ズ群を１枚で構成している。Further, the founder of the present invention performs zooming by moving the second lens group, and corrects image plane movement due to zooming by moving the third lens group. The movement of the third lens group is
Since it hardly contributes to the zooming action, it suffices that it has a weak refractive power for correcting the image plane movement, but since the second lens group largely contributes to the zooming action, the refractive power becomes strong. . According to the present invention, the image forming magnification of the second lens group is set to −1 near the middle of the wide-angle end and the telephoto end, and the second lens is a biconvex lens, and the refracting power of each surface is set to the object side. By appropriately distributing on the image side, the occurrence of various aberrations on each surface of the second lens group is suppressed as much as possible, and the second lens group is composed of one lens.
【００１４】条件式は、第２レンズ群の屈折力の適切
な範囲を示すもので、この式の下限を越えてｆ2が小さ
くなると、球面収差がプラスディオプター方向に大きく
なるとともに、誤差感度が大きくなり生産性が悪くなっ
てしまう。上限を越えてｆ2が大きくなると、第２レン
ズ群の移動量が大きくなり、コンパクト化が妨げられ
る。The conditional expression shows an appropriate range of the refracting power of the second lens group. When f 2 becomes smaller than the lower limit of this expression, spherical aberration becomes large in the plus diopter direction and error sensitivity is increased. Becomes larger and productivity becomes worse. If f 2 becomes larger than the upper limit, the amount of movement of the second lens group becomes large, which hinders downsizing.
【００１５】[0015]
【実施例】以下本発明の実像式変倍ファインダの実施例
を図１ないし図６に示す図により説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a real image type variable magnification finder of the present invention will be described below with reference to the drawings shown in FIGS.
【００１６】図１，図３，図５は順に本実施例の実像式
変倍ファインダの、実施例１から実施例３の変倍域が広
角端でのレンズ断面図を示す。FIGS. 1, 3 and 5 show lens sectional views of the real image type variable power finder of this embodiment at the wide-angle end in the variable power range of Examples 1 to 3, respectively.
【００１７】図２，図４，図６の各（ａ），（ｂ），
（ｃ）は、順に本実施例の実像式変倍ファインダの実施
例１から実施例３の変倍域が広角端，中間域，望遠端，
での収差図を示し、収差図は左から順に球面収差図，非
点収差図，歪曲収差図を示す。また、球面収差図におけ
る実線，点線はそれぞれｄ線 ｇ線を示し、非点収差図
における実線，点線はそれぞれサジタル像面，メリジオ
ナル像面を示している。2, (a), (b), and FIG.
(C) shows, in order, the variable-magnification regions of the real-image variable-magnification finder of the present embodiment, that is, the wide-angle end, the intermediate region, and the telephoto end.
The aberration diagram in Fig. 3 is shown, and the aberration diagram shows a spherical aberration diagram, an astigmatism diagram, and a distortion diagram in order from the left. Further, the solid line and the dotted line in the spherical aberration diagram show the d line and the g line, respectively, and the solid line and the dotted line in the astigmatism diagram show the sagittal image plane and the meridional image plane, respectively.
【００１８】また、各実施例中の記号は下記のものを表
わす。Further, the symbols in each embodiment represent the following.
【００１９】ｒ ：レンズ各面の曲率半径 ｄ ：レンズ厚、またはレンズ間隔 ｎd ：屈折率 νd ：アッベ数 ２ω：全画角 また非球面の形状は、光軸方向にｘ軸、光軸と垂直方向
にｙ軸をとり、ｒをレンズ各面の曲率半径、Ｋ，Ａ1，
Ａ2，Ａ3を非球面係数としたとき、次式で表わす。R: radius of curvature of each surface of the lens d: lens thickness or lens spacing n d : refractive index ν d : Abbe number 2 ω: total angle of view Further, the aspherical shape has an x axis in the optical axis direction and an optical axis. The y-axis is taken in the direction perpendicular to and r is the radius of curvature of each surface of the lens, K, A 1 ,
When A 2 and A 3 are aspherical coefficients, they are expressed by the following equation.
【００２０】[0020]
【数１】 [Equation 1]
【００２１】実施例１ ２ω＝48.2°〜17.8° ， ファインダ倍率0.39〜1.05 ｒ ｄ ｎd νd １ 21.449 1.50 1.58300 30.0 ２ 6.464 ｄ2 ３ 14.410 2.80 1.49200 57.0 ４ −14.049 ｄ4 ５ −11.581 1.50 1.58300 30.0 ６ −16.287 ｄ6 ７ 21.858 2.20 1.49200 57.0 ８ −150.000 14.92 ９ 21.500 30.30 1.49200 57.0 10 −61.750 0.30 11 23.845 2.40 1.49200 57.0 12 −32.675 17.00 可変間隔 ｄ2 22.35〜14.15〜 7.04 ｄ4 4.85〜 5.85〜20.16 ｄ6 1.30〜 8.50〜 1.30 非球面係数 第２面 Ｋ ＝−2.0690 Ａ1 ＝ 8.2577×10-4 Ａ2 ＝ 3.8381×10-6 Ａ3 ＝−1.9021×10-7 第３面 Ｋ ＝−0.36745 Ａ1 ＝−1.4774×10-5 Ａ2 ＝ 5.8667×10-7 Ａ3 ＝−3.0181×10-8 第５面 Ｋ ＝ 1.1877 Ａ1 ＝−7.7739×10-5 Ａ2 ＝ 3.0696×10-6 Ａ3 ＝−1.3332×10-7 第11面 Ｋ ＝−1.456 Ａ1 ＝−3.0285×10-5 Ａ2 ＝ 4.7909×10-7 Ａ3 ＝−4.5076×10-9 ｆ2/ｆW＝1.74 実施例２ ２ω＝48.2°〜17.9° ， ファインダ倍率0.39〜1.04 ｒ ｄ ｎd νd １ 19.607 1.50 1.58300 30.0 ２ 6.490 ｄ2 ３ 14.870 2.80 1.49200 57.0 ４ −14.265 ｄ4 ５ −11.688 1.50 1.58300 30.0 ６ −15.975 ｄ6 ７ 19.065 2.20 1.49200 57.0 ８ −229.251 14.52 ９ 21.500 30.30 1.49200 57.0 10 −61.750 0.30 11 23.845 2.40 1.49200 57.0 12 −32.675 可変間隔 ｄ2 22.31〜13.99〜 6.79 ｄ4 4.89〜 5.65〜20.41 ｄ6 1.30〜 8.86〜 1.30 非球面係数 第２面 Ｋ ＝−2.1738 Ａ1 ＝ 8.2599×10-4 Ａ2 ＝ 1.2262×10-5 Ａ3 ＝−5.8734×10-7 第５面 Ｋ ＝ 1.3682 Ａ1 ＝−7.9714×10-5 Ａ2 ＝ 3.8168×10-6 Ａ3 ＝−1.4782×10-7 第11面 Ｋ ＝−1.2801 Ａ1 ＝−3.2878×10-5 Ａ2 ＝ 4.9699×10-7 Ａ3 ＝−4.6502×10-9 ｆ2/ｆW＝1.78 実施例３ ２ω＝48.2°〜18.3° ， ファインダ倍率0.39〜1.02 ｒ ｄ ｎd νd １ 21.357 1.50 1.58300 30.0 ２ 6.475 ｄ2 ３ 14.501 2.80 1.49200 57.0 ４ −14.027 ｄ4 ５ −11.685 1.50 1.58300 30.0 ６ −16.113 ｄ6 ７ 18.950 19.00 1.49200 57.0 ８ 3.20 ９ 21.500 27.35 1.49200 57.0 10 −56.200 2.70 11 24.141 2.35 1.49200 57.0 12 −32.148 可変間隔 ｄ2 22.06〜14.04〜 7.14 ｄ4 5.14〜 5.96〜20.06 ｄ6 1.30〜 8.50〜 1.30 非球面係数 第２面 Ｋ ＝−2.0656 Ａ1 ＝ 8.1408×10-4 Ａ2 ＝ 4.5559×10-6 Ａ3 ＝−2.0982×10-7 第３面 Ｋ ＝−0.33018 Ａ1 ＝−1.2592×10-5 Ａ2 ＝ 1.8811×10-7 Ａ3 ＝−8.5439×10-11 第５面 Ｋ ＝ 1.3195 A1 ＝−6.0615×10-5 Ａ2 ＝ 1.6093×10-6 Ａ3 ＝−6.1171×10-8 第11面 Ｋ ＝−1.2801 Ａ1 ＝−3.2878×10-5 Ａ2 ＝ 4.9699×10-7 Ａ3 ＝−4.6502×10-9 ｆ2/ｆW＝1.74 実施例１および実施例２では、対物レンズ部の結像面
は、第８面と第９面の間にある。この結像面と第８面と
の間に１つの反射面を配置し、結像面より観察側のプリ
ズムに３つの反射面を設けて正立部を構成する。Example 1 2ω = 48.2 ° to 17.8 °, finder magnification 0.39 to 1.05 rd n d ν d 1 21.449 1.50 1.58300 30.0 2 6.464 d 2 3 14.410 2.80 1.49200 57.0 4 -14.049 d 4 5 -11.581 1.50 1.58300 30.0 6 -16.287 d 6 7 21.858 2.20 1.49200 57.0 8 -150.000 14.92 9 21.500 30.30 1.49200 57.0 10 -61.750 0.30 11 23.845 2.40 1.49200 57.0 12 -32.675 17.00 variable spacing d 2 22.35~14.15~ 7.04 d 4 4.85~ 5.85~20.16 d 6 1.30 to 8.50 to 1.30 Aspheric coefficient 2nd surface K = -2.0690 A 1 = 8.2577 x 10 -4 A 2 = 3.8381 x 10 -6 A 3 = -1.902 1 x 10 -7 3rd surface K = -0.36745 A 1 = −1.4774 × 10 −5 A 2 = 5.8667 × 10 −7 A 3 = −3.0181 × 10 −8 Fifth surface K = 1.1877 A 1 = −7.7739 × 10 −5 A 2 = 3.0696 × 10 −6 A 3 = − 1.3332 × 10 −7 11th surface K = −1.456 A 1 = −3.0285 × 10 −5 A 2 = 4.7909 × 10 −7 A 3 = −4.5076 × 10 −9 f 2 / f W = 1.74 Example 2 2ω = 48.2 ° ~ 17.9 °, viewfinder magnification 0.39 to 1.04 r d n d ν d 1 19.607 1.50 1.58300 30.0 2 6.490 d 2 3 14.870 2.80 1.49200 57.0 4 −14.265 d 4 5 −11.688 1.50 1.58300 30.0 6 −15.975 d 6 7 19.065 2.20 1.49200 57.0 8 −229.251 14.52 9.52 30.30 1.49200 57.0 10 −61.750 0.30 11 23.845 2.40 1.49200 57.0 12 −32.675 Variable spacing d 2 22.31 ~ 13.99 ~ 6.79 d 4 4.89 ~ 5.65 ~ 20.41 d 6 1.30 ~ 8.86 ~ 1.30 Aspheric surface 2nd surface K = -2.1738 A 1 = 8.2599 × 10 -4 A 2 = 1.2262 × 10 -5 A 3 = -5.8734 × 10 -7 5th surface K = 1.3682 A 1 = -7.9714 × 10 -5 A 2 = 3.8168 × 10 -6 A 3 =- 1.4782 × 10 −7 11th surface K = −1.2801 A 1 = −3.2878 × 10 −5 A 2 = 4.99699 × 10 −7 A 3 = −4.6502 × 10 −9 f 2 / f W = 1.78 Example 3 2ω = 48.2 ° to 18.3 °, viewfinder magnification 0.39 to 1.02 rd n d ν d 1 21.357 1.50 1.58300 30.0 2 6.475 d 2 3 14.501 2.80 1.49200 57.0 4 -14.027 d 4 5 -11.685 1.50 1.58300 30.0 6 -16.113 d 6 7 18.950 19.00 1.49200 57.0 8 3.20 9 21.500 27.35 1.49200 57.0 10 −56.200 2.70 11 24.141 2.35 1.49200 57.0 12 −32.148 Variable spacing d 2 22.06 ~ 14.04 ~ 7.14 d 4 5.14 ~ 5.96 ~ 20.06 d 6 1.30 ~ 8.50 ~ 1.30 Aspheric coefficient second Surface K = -2.0656 A 1 = 8.1408 × 10 -4 A 2 = 4.5559 × 10 -6 A 3 = -2.0982 × 10 -7 3rd surface K = -0.33018 A 1 = -1.2592 × 10 -5 A 2 = 1.8811 × 10 -7 A 3 = -8.5439 × 10 -11 5th surface K = 1.3195 A 1 = -6.0615 × 10 -5 A 2 = 1.6093 × 10 -6 A 3 = -6.1171 × 10 -8 11th surface K = −1.2801 A 1 = −3.2878 × 10 −5 A 2 = 4.996 99 × 10 −7 A 3 = −4.6502 × 10 −9 f 2 / f W = 1.74 In the first and second embodiments, the image formation of the objective lens unit is performed. The surface is between the eighth surface and the ninth surface. One reflecting surface is arranged between the image forming surface and the eighth surface, and three reflecting surfaces are provided on the prism on the observation side of the image forming surface to form an erecting portion.
【００２２】実施例３では、対物レンズ部の結像面は、
第８面と第９面の間にある。第４メンズ群が正立のため
のプリズムと一体となっており、このプリズムに２つの
反射面を設け、結像面より観察側のプリズムに２つの反
射面を設けて正立部を構成する。In the third embodiment, the image plane of the objective lens unit is
It is between the eighth surface and the ninth surface. The fourth men's group is integrated with an erecting prism. Two emissive surfaces are provided on this prism, and two emissive surfaces are provided on the prism on the observation side of the image plane to form an erecting portion. .
【００２３】[0023]
【発明の効果】本発明により、2.5倍以上の変倍比を有
しながら、見え味が良く、かつコンパクトで低コストの
実像式変倍ファインダが提供されることとなった。As described above, according to the present invention, it is possible to provide a real image type zoom finder which has a zoom ratio of 2.5 times or more, has a good appearance, is compact, and is low in cost.
【図面の簡単な説明】[Brief description of drawings]
【図１】本発明に基づく実像式変倍ファインダの、実施
例１の変倍域が広角端でのレンズ断面図。FIG. 1 is a lens cross-sectional view of a real image type variable power finder according to the present invention at a wide angle end in a variable power range of Embodiment 1.
【図２】本発明に基づく実像式変倍ファインダの、実施
例１の変倍域が広角端，中間域，望遠端での収差図。FIG. 2 is an aberration diagram of a real image type variable power finder according to the present invention at a wide angle end, an intermediate range, and a telephoto end in a variable power region of Example 1;
【図３】本発明に基づく実像式変倍ファインダの、実施
例２の変倍域が広角端でのレンズ断面図。FIG. 3 is a lens cross-sectional view of a real image type variable power finder according to the present invention when the variable power range of Embodiment 2 is at the wide-angle end.
【図４】本発明に基づく実像式変倍ファインダの、実施
例２の変倍域が広角端，中間域，望遠端での収差図。FIG. 4 is an aberration diagram of a real image type variable power finder according to the present invention at a wide angle end, an intermediate range, and a telephoto end in a variable power region of Example 2;
【図５】本発明に基づく実像式変倍ファインダの、実施
例３の変倍域が広角端でのレンズ断面図。FIG. 5 is a lens cross-sectional view of a variable-magnification region of Embodiment 3 of the real-image type variable-magnification finder according to the present invention at the wide-angle end.
【図６】本発明に基づく実像式変倍ファインダの、実施
例３の変倍域が広角端，中間域，望遠端での収差図。6A, 6B, 6C, 6D, 6E, 6F, 6G, 6H, 6I, 6I, 6I, 6I, 6I, 6I, 6I, 6I, 6I, 6I, 6I, 6I, 6F, 6I, 6I, 6I, 6I and 6I are aberration diagrams of the real image type variable power finder based on the present invention at the wide angle end, the intermediate range, and the telephoto end in the variable power range of Example 3.
Claims (2)
た、非球面を有する１枚の負メニスカスレンズからなる
第１レンズ群、１枚の両凸レンズからなる第２レンズ
群、１枚の負レンズからなる第３レンズ群、１枚の正レ
ンズからなる第４レンズ群を有し、前記第２レンズ群と
第３レンズ群が移動することにより変倍を行う対物レン
ズ部と、接眼レンズとから構成されることを特徴とする
実像式変倍ファインダ。1. A first lens group consisting of one negative meniscus lens having an aspherical surface with a convex surface facing the object side in order from the object side, a second lens group consisting of one biconvex lens, and one An objective lens unit having a third lens group composed of a negative lens and a fourth lens group composed of one positive lens, and performing zooming by moving the second lens group and the third lens group, and an eyepiece lens. A real-image variable-magnification viewfinder characterized by being composed of and.
立させるためのプリズムと一体としたことを特徴とする
請求項１記載の実像式変倍ファインダ。2. The real image type variable magnification finder according to claim 1, wherein the fourth lens group which is a positive lens is integrated with a prism for erecting an image.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23986093A JPH0792386A (en) | 1993-09-27 | 1993-09-27 | Real image system variable power finder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23986093A JPH0792386A (en) | 1993-09-27 | 1993-09-27 | Real image system variable power finder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0792386A true JPH0792386A (en) | 1995-04-07 |
Family
ID=17050961
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23986093A Pending JPH0792386A (en) | 1993-09-27 | 1993-09-27 | Real image system variable power finder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0792386A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4672827B2 (en) * | 2000-01-28 | 2011-04-20 | 株式会社栃木ニコン | Zoom lens and projection display device including the zoom lens |
-
1993
- 1993-09-27 JP JP23986093A patent/JPH0792386A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4672827B2 (en) * | 2000-01-28 | 2011-04-20 | 株式会社栃木ニコン | Zoom lens and projection display device including the zoom lens |
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