JPH05119274A - Evf lens - Google Patents
Evf lensInfo
- Publication number
- JPH05119274A JPH05119274A JP3284368A JP28436891A JPH05119274A JP H05119274 A JPH05119274 A JP H05119274A JP 3284368 A JP3284368 A JP 3284368A JP 28436891 A JP28436891 A JP 28436891A JP H05119274 A JPH05119274 A JP H05119274A
- Authority
- JP
- Japan
- Prior art keywords
- lens
- evf
- lenses
- aspherical surface
- epsilon2
- 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
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- Lenses (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明はビデオカメラなどに好適
な電子ビューファインダ用レンズ（以下ＥＶＦレンズと
略称する）に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic viewfinder lens (hereinafter referred to as an EVF lens) suitable for a video camera or the like.
【０００２】[0002]
【従来の技術】近年、ビデオカメラの普及に伴い、ＥＶ
Ｆレンズの小型，軽量化が強く要望されている。2. Description of the Related Art In recent years, with the spread of video cameras, EV
There is a strong demand for smaller and lighter F lenses.
【０００３】以下、図面を参照しながら、従来のＥＶＦ
レンズの一例について説明する。図４は従来のＥＶＦレ
ンズの構成を示すもので、物体面６とアイポイント７の
間に非球面を含む１枚の両凸のプラスチックレンズ５に
よって構成されている。A conventional EVF will now be described with reference to the drawings.
An example of the lens will be described. FIG. 4 shows a structure of a conventional EVF lens, which is composed of one biconvex plastic lens 5 including an aspherical surface between an object plane 6 and an eye point 7.
【０００４】以上のような構成の従来のＥＶＦレンズに
ついて、以下その動作を説明すると、物体面６すなわち
ＣＲＴ，液晶等の表示面からほぼレンズ５の焦点距離の
位置にレンズ５を設置し、このレンズ５で拡大した像を
アイポイント７より観測するようにしたものである。こ
の場合、単純にはビューファインダの全長を短くするに
は拡大率を大にすればよいが、そうすると諸収差が悪化
することや、液晶画素の境目が目立ち観測妨害になるた
め、拡大率は最適な値に抑えなければならない。The operation of the conventional EVF lens having the above structure will be described below. The lens 5 is installed at a position approximately the focal length of the lens 5 from the object plane 6, that is, the display surface such as the CRT or the liquid crystal. The image magnified by the lens 5 is observed from the eye point 7. In this case, simply increasing the magnifying power can shorten the total length of the viewfinder, but if this is done, various aberrations will be aggravated and the boundaries of the liquid crystal pixels will be noticeable and obstruct the observation. Must be kept to a certain value.
【０００５】[0005]
【発明が解決しようとする課題】しかしながら、上記従
来のレンズ１枚だけの構成では最適な拡大率を維持し、
かつ全長を短く小型にするという点では不十分であると
いう問題点を有していた。However, the above-mentioned conventional configuration with only one lens maintains an optimum magnification ratio,
Moreover, there is a problem in that it is insufficient in terms of shortening the overall length and reducing the size.
【０００６】本発明は上記従来の問題点を解決し、最適
な拡大率を維持しながら、物体面とアイポイント間の距
離を縮小し機器を小型にするＥＶＦレンズを提供するの
を目的とする。SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems and to provide an EVF lens that reduces the distance between the object plane and the eyepoint and downsizes the device while maintaining the optimum magnification. ..
【０００７】[0007]
【課題を解決するための手段】本発明のＥＶＦレンズは
上記目的を達成するために、物体に近い側の第１レンズ
は断面図において左右対称の負の非球面形状をもち、物
体から遠い側の第２レンズは断面図において左右対称の
正の非球面形状をもち、 −２．０≦ε1≦１．０ （１） ε2＝０．５×ε1−０．５ （２） （ただし、ε1，ε2は、それぞれ第１，第２レンズの非
球面形状を表す円錐係数）の条件を満足するような構成
を備えたものである。In order to achieve the above object, the EVF lens of the present invention has a first lens on the side closer to the object, which has a symmetrical negative aspherical shape in a sectional view, and a side far from the object. Has a bilaterally symmetrical positive aspherical shape in a sectional view, and is −2.0 ≦ ε 1 ≦ 1.0 (1) ε 2 = 0.5 × ε 1 −0.5 (2) ( However, ε 1 and ε 2 are configured so as to satisfy the condition of (conical coefficient representing the aspherical shape of the first and second lenses).
【０００８】[0008]
【作用】本発明は上記の構成によりレンズ系の最適な拡
大率を変化させることなく、物体とアイポイント間の距
離を縮小することができる。According to the present invention, the distance between the object and the eye point can be reduced without changing the optimum magnification of the lens system by the above structure.
【０００９】[0009]
【実施例】以下、本発明の一実施例のＥＶＦレンズにつ
いて図面を参照しながら説明する。図１は本発明の一実
施例のＥＶＦレンズの構成図である。図１において物体
面に近い側の第１レンズ１は断面図において左右対称の
負の非球面形状をもち、物体から遠い側の第２レンズ２
は断面図において左右対称の正の非球面形状をもってい
る。また、ｒ1，ｒ2は第１レンズ１の物体面側の面とそ
の反対側の面の曲率半径、ｒ3，ｒ4は第２レンズ２の物
体面側の面とその反対側の面の曲率半径、ｄ 1，ｄ2およ
びｄ3は、それぞれ第１レンズ１のレンズ面間の肉厚、
第１レンズ１と第２レンズ２間の空気間隔および第２レ
ンズ２のレンズ面間の肉厚である。EXAMPLE An EVF lens according to an example of the present invention will be described below.
And will be described with reference to the drawings. FIG. 1 shows one example of the present invention.
It is a block diagram of the EVF lens of an Example. Object in Figure 1
The first lens 1 on the side closer to the surface is symmetrical in cross section.
The second lens 2 having a negative aspherical shape and located far from the object
Has a symmetrical positive aspherical shape in cross section
It Also, r1, R2Is the object-side surface of the first lens 1 and its
Radius of curvature of the surface on the opposite side of, r3, RFourIs the second lens 2
The radius of curvature of the surface on the body surface side and the surface on the opposite side, d 1, D2And
And d3Is the wall thickness between the lens surfaces of the first lens 1,
The air gap between the first lens 1 and the second lens 2 and the second lens
It is the thickness between the lens surfaces of lens 2.
【００１０】以下、このように構成されたＥＶＦレンズ
の実施数値例を（表１）に、また、第１，第２レンズの
非球面形状をそれぞれ表す円錐係数であるε1とε2の組
合せを変えた場合の最大横収差ΔＹと最大歪曲収差ＤＩ
ＳＴの値を（表２）に示す。また図３のε1，ε2の組合
せの座標に対応している番号は（表２）のε1，ε2の組
合せの番号を示している。The numerical values of the EVF lens thus constructed are shown in Table 1 below, and the combination of ε 1 and ε 2 which are the conical coefficients representing the aspherical shapes of the first and second lenses, respectively. Maximum lateral aberration ΔY and maximum distortion aberration DI when changing
The value of ST is shown in (Table 2). The numbers corresponding to the coordinates of the combination of ε 1 and ε 2 in FIG. 3 are the numbers of the combinations of ε 1 and ε 2 in (Table 2).
【００１１】表中、ｎ1，ｎ2は第１，第２レンズのｄ線
に対する屈折率、ｖ1，ｖ2は第１，第２レンズのｄ線に
対するアッベ数である。In the table, n 1 and n 2 are the refractive indices of the first and second lenses with respect to the d-line, and v 1 and v 2 are Abbe numbers of the first and second lenses with respect to the d-line.
【００１２】[0012]
【表１】 [Table 1]
【００１３】物体面は第１レンズの左面より３２mmの位
置、物体の大きさは１４．５６mm×１１．２２mmとす
る。The object surface is located 32 mm from the left surface of the first lens, and the size of the object is 14.56 mm × 11.22 mm.
【００１４】[0014]
【表２】 [Table 2]
【００１５】以上のように構成され、また（表１）のよ
うな数値をもったＥＶＦレンズについて、以下図１およ
び図２を参照しながら説明する。図２ａ，ｂ，ｃおよび
ｄはそれぞれこの実施例の収差性能を示す。An EVF lens configured as described above and having numerical values as shown in (Table 1) will be described below with reference to FIGS. 1 and 2. 2a, b, c and d respectively show the aberration performance of this example.
【００１６】図２ａでは、実線はｄ線、破線はＦ線、そ
して一点鎖線はｃ線に対する球面収差を示し、図２ｂで
は実線はサジタル像面湾曲を、破線はメリデオナル像面
湾曲を示し、図２ｃでは歪曲収差を示し、図２ｄでは実
線はｄ線に対するＦ線の、破線はｄ線に対するｃ線の倍
率色収差を示す。第１，第２レンズ１，２は、アイポイ
ント４より最適な大きさの像を観測できるように動作す
る。図２では小型化のため、屈折力の強い第１，第２レ
ンズを用いたにもかかわらず、良好な光学性能を有する
ことを示している。また第１，第２レンズ１，２の非球
面形状をそれぞれ表す円錐係数であるε1，ε2の値を変
えた組合せを示す図３の座標番号に対応する表２の結果
を検討し、 −２．０≦ε1≦１．０ （１） ε2＝０．５×ε1−０．５ （２） の条件の範囲であれば、最大横収差ΔＹの値は２ディオ
プターを越えず、また最大歪曲収差ＤＩＳＴも１％を越
えず、良好な画像性能を得られることがわかった。この
ようにε1とε2の値を設定することによりＥＶＦレンズ
として最適な小型軽量化を達成できる。なお、レンズ材
質はＥＶＦレンズの性格と、非球面を用いるので、加工
上から通常プラスチックレンズを用いるが、ガラス等他
の材質の使用を妨げない。In FIG. 2a, the solid line shows the d-line, the broken line shows the f-line, and the dash-dotted line shows the spherical aberration with respect to the c-line. In FIG. 2b, the solid line shows the sagittal field curvature, and the broken line shows the meridional field curvature. 2c shows distortion, and in FIG. 2d, the solid line shows the chromatic aberration of magnification of the F line with respect to the d line, and the broken line shows the chromatic aberration of magnification of the c line with respect to the d line. The first and second lenses 1 and 2 operate so that an image of an optimum size can be observed from the eye point 4. FIG. 2 shows that the optical performance is good even though the first and second lenses having strong refractive power are used for downsizing. In addition, the results of Table 2 corresponding to the coordinate numbers of FIG. 3 showing combinations in which the values of the conical coefficients ε 1 and ε 2 representing the aspherical shapes of the first and second lenses 1 and 2 are changed are examined. −2.0 ≦ ε 1 ≦ 1.0 (1) Within the condition of ε 2 = 0.5 × ε 1 −0.5 (2), the maximum lateral aberration ΔY does not exceed 2 diopters. It was also found that the maximum distortion aberration DIST does not exceed 1%, and that good image performance can be obtained. By setting the values of ε 1 and ε 2 in this way, it is possible to achieve the optimal size and weight reduction as an EVF lens. Since the lens material is an EVF lens and an aspherical surface is used, a plastic lens is usually used from the viewpoint of processing, but the use of other materials such as glass is not hindered.
【００１７】[0017]
【発明の効果】以上説明したように本発明のＥＶＦレン
ズは、物体に近い側の第１レンズは左右対称の負の非球
面形状をもち、物体から遠い側の第２レンズは左右対称
の正の非球面形状をもち、それぞれ第１，第２レンズの
非球面形状を表す円錐係数の間に上記に示すような条件
を満足するように構成したことによって、最適な拡大率
を維持し、良好な性能を保ちながら、レンズ部分の全長
が短く、小型にできる優れた効果を得ることができる。As described above, in the EVF lens of the present invention, the first lens on the side closer to the object has a symmetrical negative aspherical shape, and the second lens on the side far from the object is symmetrical on the positive side. By having the aspherical shape of and satisfying the above condition between the conic coefficients representing the aspherical shapes of the first and second lenses, respectively, the optimum magnification can be maintained and good While maintaining good performance, the overall length of the lens portion is short, and it is possible to obtain the excellent effect of miniaturization.
【図１】本発明の一実施例のＥＶＦレンズの構成図FIG. 1 is a configuration diagram of an EVF lens according to an embodiment of the present invention.
【図２】同実施例のＥＶＦレンズの収差図FIG. 2 is an aberration diagram of the EVF lens of the same example.
【図３】同実施例における円錐係数ε1，ε2の組合せ座
標図FIG. 3 is a combination coordinate diagram of conic coefficients ε 1 and ε 2 in the example.
【図４】従来のＥＶＦレンズの構成図FIG. 4 is a configuration diagram of a conventional EVF lens.
１ 第１レンズ ２ 第２レンズ ３ 物体面 ４ アイポイント 1 1st lens 2 2nd lens 3 Object plane 4 Eyepoint
Claims (1)
いて左右対称の負の非球面形状をもち、物体から遠い側
の第２レンズは断面図において左右対称の正の非球面形
状をもち、 −２．０≦ε1≦１．０ （１） ε2＝０．５×ε1−０．５ （２） （ただし、ε1，ε2は、それぞれ第１，第２レンズの非
球面形状を表す円錐係数）の条件を満足するように構成
したことを特徴とするＥＶＦレンズ。1. A first lens closer to the object has a symmetrical negative aspherical shape in a sectional view, and a second lens farther from the object has a symmetrical positive aspherical shape in a sectional view. , -2.0 ≤ ε 1 ≤ 1.0 (1) ε 2 = 0.5 × ε 1 -0.5 (2) (where ε 1 and ε 2 are the non-alignment factors of the first and second lenses, respectively). An EVF lens configured so as to satisfy a condition of a conical coefficient representing a spherical shape).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3284368A JP2806104B2 (en) | 1991-10-30 | 1991-10-30 | EVF lens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3284368A JP2806104B2 (en) | 1991-10-30 | 1991-10-30 | EVF lens |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05119274A true JPH05119274A (en) | 1993-05-18 |
| JP2806104B2 JP2806104B2 (en) | 1998-09-30 |
Family
ID=17677678
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3284368A Expired - Fee Related JP2806104B2 (en) | 1991-10-30 | 1991-10-30 | EVF lens |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2806104B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20000059525A (en) * | 1999-03-04 | 2000-10-05 | 윤종용 | Optical system having a high magnification viewfinder lens |
| US6958863B2 (en) | 2001-01-30 | 2005-10-25 | Olympus Corporation | Image pickup system |
| CN106371212A (en) * | 2016-10-25 | 2017-02-01 | 创扬通信技术（深圳）有限公司 | VR/MR optical system of dual-element convex-concave lens and VR/MR device |
| US11092798B2 (en) | 2018-03-02 | 2021-08-17 | Canon Kabushiki Kaisha | Observation apparatus and image pickup apparatus |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4081318B2 (en) | 2002-07-11 | 2008-04-23 | オリンパス株式会社 | Imaging device |
-
1991
- 1991-10-30 JP JP3284368A patent/JP2806104B2/en not_active Expired - Fee Related
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20000059525A (en) * | 1999-03-04 | 2000-10-05 | 윤종용 | Optical system having a high magnification viewfinder lens |
| US6958863B2 (en) | 2001-01-30 | 2005-10-25 | Olympus Corporation | Image pickup system |
| USRE40563E1 (en) | 2001-01-30 | 2008-11-04 | Olympus Corporation | Image pickup system |
| US7529031B2 (en) | 2001-01-30 | 2009-05-05 | Olympus Corporation | Image pickup system |
| US7593162B2 (en) | 2001-01-30 | 2009-09-22 | Olympus Corporation | Image pickup system |
| US7599121B2 (en) | 2001-01-30 | 2009-10-06 | Olympus Corporation | Image pickup system |
| US7605982B2 (en) | 2001-01-30 | 2009-10-20 | Olympus Corporation | Image pickup system |
| CN106371212A (en) * | 2016-10-25 | 2017-02-01 | 创扬通信技术（深圳）有限公司 | VR/MR optical system of dual-element convex-concave lens and VR/MR device |
| CN106371212B (en) * | 2016-10-25 | 2019-06-14 | 深圳市原点创新有限公司 | The VR/MR optical system and VR/MR equipment of dual element convex-concave eyeglass |
| US11092798B2 (en) | 2018-03-02 | 2021-08-17 | Canon Kabushiki Kaisha | Observation apparatus and image pickup apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2806104B2 (en) | 1998-09-30 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |