JPH05346541A - Rear conversion lens - Google Patents
Rear conversion lensInfo
- Publication number
- JPH05346541A JPH05346541A JP4154787A JP15478792A JPH05346541A JP H05346541 A JPH05346541 A JP H05346541A JP 4154787 A JP4154787 A JP 4154787A JP 15478792 A JP15478792 A JP 15478792A JP H05346541 A JPH05346541 A JP H05346541A
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- JP
- Japan
- Prior art keywords
- lens
- rear conversion
- conversion lens
- focal length
- main
- 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.)
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、主レンズ系の像面側に
挿脱することにより全系の焦点距離を変化させるリアコ
ンバージョンレンズに関し、特に、レンズシャッターカ
メラに好適なリアコンバージョンレンズに関するもので
ある。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear conversion lens for changing the focal length of the whole system by inserting and removing it in the image plane side of a main lens system, and more particularly to a rear conversion lens suitable for a lens shutter camera. Is.
【０００２】[0002]
【従来の技術】近年、レンズシャッターカメラにおい
て、主レンズ系の像面側にコンバージョンレンズを挿入
して焦点距離を切り換える、いわゆる２焦点カメラ用の
レンズ系が種々提案されている。このようなレンズ系の
例として、特開昭６１−１４４６１７号、特開昭６２−
２４７３１５号のものがあげられる。近年、レンズシャ
ッターカメラのレンズ系の画角をより広くすることが望
まれているが、画角を広くすることにより、軸上収差と
軸外収差のバランスがとり難くなり、また、バランスを
とるためにレンズ枚数を増すと、レンズ系が大きくなっ
てしまい、小型化が望まれているレンズシャッターカメ
ラには不向きなものとなってしまう。上記の先行例に
は、広画角化に対する処置がとられていない。2. Description of the Related Art In recent years, in lens shutter cameras, various lens systems for so-called bifocal cameras have been proposed in which a conversion lens is inserted on the image plane side of a main lens system to switch the focal length. Examples of such a lens system include JP-A-61-144617 and JP-A-62-162.
No. 247315 can be given. In recent years, it has been desired to widen the angle of view of the lens system of the lens shutter camera. However, by widening the angle of view, it becomes difficult to balance the axial aberration and the off-axis aberration, and also the balance is achieved. Therefore, if the number of lenses is increased, the lens system becomes large, which is unsuitable for a lens shutter camera that is desired to be downsized. No measures have been taken for widening the angle of view in the preceding examples.
【０００３】[0003]
【発明が解決しようとする課題】本発明はこのような問
題に鑑みてなされたものであり、その目的は、コンバー
ジョンレンズ方式による画角域の広画角化を達成しつ
つ、変倍比約１．６程度で、小型化を損なわないリアコ
ンバージョンレンズを提供することである。SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to achieve a wide field angle in a field angle range by a conversion lens system while achieving a variable power ratio. It is to provide a rear conversion lens having a size of about 1.6, which does not impair miniaturization.
【０００４】[0004]
【課題を解決するための手段】上記目的を達成する本発
明のリアコンバージョンレンズは、主レンズ系の像面側
に挿脱可能に配置され、その挿脱に伴って全系の焦点距
離を変化させる負の屈折力のリアコンバージョンレンズ
において、主レンズ側から順に、像側に凸面を向けた正
メニスカスレンズの第１レンズと、正レンズの第２レン
ズと、負レンズの第３レンズとからなると共に、以下の
条件（１）、（２）を満足することを特徴とするもので
ある。A rear conversion lens of the present invention that achieves the above object is arranged so that it can be inserted and removed on the image plane side of the main lens system, and the focal length of the entire system changes with the insertion and removal. In the rear conversion lens having a negative refractive power, the first lens is a positive meniscus lens having a convex surface facing the image side, the second lens is a positive lens, and the third lens is a negative lens, in order from the main lens side. In addition, it is characterized in that the following conditions (1) and (2) are satisfied.
【０００５】 （１）−６．０＜（Ｒ2 ＋Ｒ1 ）／（Ｒ2 −Ｒ1 ）＜−２．０ （２）０．０２＜Ｄ2 ／｜ｆR ｜ ＜０．０５ ただし、ここで、Ｒ1 、Ｒ2 はそれぞれ前記第１レンズ
の前面、後面の曲率半径、Ｄ2 は前記第１レンズと第２
レンズの軸上間隔、ｆR は前記リアコンバージョンレン
ズ全系の焦点距離である。(1) −6.0 <(R 2 + R 1 ) / (R 2 −R 1 ) <− 2.0 (2) 0.02 <D 2 / | f R | <0.05, where R 1 and R 2 are the radii of curvature of the front surface and the rear surface of the first lens, respectively, and D 2 is the first lens and the second lens.
The axial distance of the lens, f R, is the focal length of the entire rear conversion lens system.
【０００６】[0006]
【作用】以下、上記構成を採用する理由と作用について
説明する。リアコンバージョンレンズ方式により得られ
る画角域を広画角化することにより、軸上収差と軸外収
差のバランス補正が困難となるのだが、そのバランスを
とる条件式が（１）、（２）式である。（１）式は、軸
上収差に対して軸外収差をバランス補正するための条件
で、特に非点収差の補正に有効である。前記第１レンズ
の形状を像側に凸面を向けたメニスカス形状にすること
により、前記第１レンズに対する軸外光線の入射角を小
さくすることができ、軸外収差に対して無理のない補正
をすることができる。The function and operation of adopting the above configuration will be described below. By widening the angle of view obtained by the rear conversion lens system, it becomes difficult to correct the balance between the axial aberration and the off-axis aberration, but the conditional expressions for achieving this balance are (1) and (2). It is an expression. The expression (1) is a condition for balance correction of off-axis aberration with respect to on-axis aberration, and is particularly effective for correction of astigmatism. By making the shape of the first lens a meniscus shape with the convex surface facing the image side, the incident angle of the off-axis light ray on the first lens can be made small, and the off-axis aberration can be corrected without difficulty. can do.
【０００７】（１）式の下限を超えると、前記第１レン
ズの物体側の面の屈折力が増し、軸上収差と軸外収差の
バランスが崩れ、特に非点収差に影響を及ぼす。また、
その上限を超えると、逆に、前記第１レンズの物体側の
面の屈折力が弱まり過ぎ、軸外収差、特にコマ収差が悪
化する。When the value goes below the lower limit of the expression (1), the refracting power of the object side surface of the first lens increases, and the balance between the axial aberration and the off-axis aberration is disturbed, which particularly affects astigmatism. Also,
If the upper limit is exceeded, conversely, the refracting power of the object-side surface of the first lens becomes too weak, and off-axis aberrations, especially coma aberration, deteriorate.
【０００８】（２）式は、軸上収差と軸外収差のバラン
スを保つための条件で、前記第１レンズと第２レンズ間
の空気レンズを有効に生かすための条件である。（２）
式の下限は軸上収差に関するもので、その下限を超える
と、球面収差が補正過剰となる。（２）式の上限は軸外
収差に関するもので、その上限を超えると、コマ収差が
悪化する。The expression (2) is a condition for maintaining the balance between the axial aberration and the off-axis aberration, and is a condition for effectively utilizing the air lens between the first lens and the second lens. (2)
The lower limit of the equation relates to axial aberration, and if the lower limit is exceeded, spherical aberration will be overcorrected. The upper limit of the equation (2) relates to off-axis aberration, and if it exceeds the upper limit, coma becomes worse.
【０００９】さらに、前記第１レンズと第２レンズの間
の空気レンズの屈折力をφ23とすると、 （３）ｆR ・φ23＜０ とすることにより、前記第１レンズ、第２レンズの負担
を軽減し、軸上及び軸外光線に対し、無理なパワーを与
えずに補正することができる。Further, assuming that the refracting power of the air lens between the first lens and the second lens is φ 23 , (3) f R · φ 23 <0, so that the first lens and the second lens It is possible to reduce the load of and to correct on-axis and off-axis rays without giving undue power.
【００１０】第１レンズ、第２レンズの屈折力を小さく
すると、ペッツバール和が減少し、像面湾曲、非点収差
の補正が困難となるが、（１）式によって良好に補正が
行われる。また、像面湾曲の補正を容易にするため、前
記第１レンズ、第２レンズ、第３レンズの屈折率を
Ｎ1 、Ｎ2 、Ｎ3 とすると、 （４）（Ｎ1 ＋Ｎ2 ）／２＜１．７ （５）Ｎ3 ＞１．８ を満たすようにすることが望ましい。条件式（４）、
（５）から外れると、ペッツバール和が減少し、像面湾
曲の補正が困難になる。If the refracting powers of the first lens and the second lens are reduced, the Petzval sum is reduced and it becomes difficult to correct the field curvature and astigmatism, but the correction is satisfactorily performed by the equation (1). Further, in order to facilitate the correction of the field curvature, if the refractive indices of the first lens, the second lens, and the third lens are N 1 , N 2 , and N 3 , then (4) (N 1 + N 2 ) / It is desirable to satisfy 2 <1.7 (5) N 3 > 1.8. Conditional expression (4),
If it deviates from (5), the Petzval sum will decrease, making it difficult to correct the field curvature.
【００１１】本発明におけるフォーカシングとしては、
主レンズ系を物体側へ繰り出す方式が考えられる。この
方式は、リアコンバージョンレンズの有無に関わらず、
繰り出し量が一定であるという利点がある。また、リア
コンバージョンレンズを含めた全系を繰り出すようにし
てもよい。この方式だと、繰り出しに対して周辺光量の
減りが少なく、そのため、繰り出し量を多くとることが
でき、至近撮影には好適な方式である。Focusing in the present invention includes:
A method of extending the main lens system to the object side is possible. This method, whether or not there is a rear conversion lens,
There is an advantage that the amount of feeding is constant. Alternatively, the entire system including the rear conversion lens may be extended. With this method, the amount of peripheral light is less reduced with respect to the extension, and therefore, the extension amount can be increased, which is suitable for close-up photography.
【００１２】[0012]
【実施例】以下、図面を参照にして本発明のリアコンバ
ージョンレンズの実施例１〜４について説明する。ま
ず、このリアコンバージョンレンズを装着する主レンズ
系ＭＬの例として、図１に断面を示すようなトリプレッ
トレンズを用いるものとする。このレンズＭＬのレンズ
データは後記する。EXAMPLES Examples 1 to 4 of the rear conversion lens of the present invention will be described below with reference to the drawings. First, as an example of the main lens system ML to which this rear conversion lens is attached, a triplet lens whose cross section is shown in FIG. 1 is used. The lens data of this lens ML will be described later.
【００１３】このような主レンズ系ＭＬの像側に、図２
に示すように、本発明によるリアコンバージョンレンズ
ＲＣＬを装着する。図２のリアコンバージョンレンズＲ
ＣＬは実施例１のものであるが、何れの実施例において
も、像側に凸面を向けた正メニスカスレンズ、像側に凸
面を向けた正メニスカスレンズ、像側に凸面を向けた負
メニスカスレンズからなるので、実施例２〜４のレンズ
の図示は省略する。On the image side of such a main lens system ML, FIG.
As shown in, the rear conversion lens RCL according to the present invention is mounted. Rear conversion lens R in Figure 2
CL is that of the first embodiment, but in any of the embodiments, a positive meniscus lens having a convex surface facing the image side, a positive meniscus lens having a convex surface facing the image side, and a negative meniscus lens having a convex surface facing the image side are used. Therefore, the illustration of the lenses of Examples 2 to 4 is omitted.
【００１４】以下に、主レンズ系と各実施例のリアコン
バージョンレンズのレンズデータを示すが、記号は、上
記の外、Ｆは主レンズ系の焦点距離又はリアコンバージ
ョンレンズを主レンズ系に装着したときの全系の焦点距
離、ＦNOは主レンズ系のＦナンバー又は主レンズ系にリ
アコンバージョンレンズを装着したときの全系のＦナン
バー、ωは主レンズ系の半画角又はリアコンバージョン
レンズを主レンズ系に装着したときの全系の画角、
ｒ1 、ｒ2 …は各レンズ面の曲率半径、ｄ1 、ｄ2…は
各レンズ面間の間隔、ｎd1、ｎd2…は各レンズのｄ線の
屈折率、νd1、νd2…は各レンズのアッベ数である。ま
た、ｄ0 は主レンズ系の絞り位置からリアコンバージョ
ンレンズ第１面の間の間隔である。なお、主レンズ系の
各レンズ面の曲率半径、各レンズ面間の間隔、各レンズ
のｄ線の屈折率、アッベ数については、それぞれ
ｒi ' 、ｄi ' 、ｎdi ' 、νdi ' と表記してある。The lens data of the main lens system and the rear conversion lens of each embodiment are shown below. The symbols are the above, and F is the focal length of the main lens system or the rear conversion lens is attached to the main lens system. Is the focal length of the whole system, F NO is the F number of the main lens system or the F number of the whole system when a rear conversion lens is attached to the main lens system, and ω is the half angle of view of the main lens system or the rear conversion lens. Angle of view of the entire system when attached to the main lens system,
r 1 , r 2 ... Radius of curvature of each lens surface, d 1 , d 2 ... Spacing between lens surfaces, n d1 , n d2 ..., Refractive index of d-line of each lens, v d1 , v d2 . Is the Abbe number of each lens. Further, d 0 is the distance between the diaphragm position of the main lens system and the first surface of the rear conversion lens. The radius of curvature of each lens surface of the main lens system, the distance between the lens surfaces, the d-line refractive index of each lens, and the Abbe number are r i ′ , d i ′ , n di ′ , and ν di ′, respectively. Is written.
【００１５】また、何れの実施例においても、２番目の
正メニスカスレンズの前面（ｒ3 ）に非球面を用いてお
り、その非球面形状は、光軸方向をｘ、光軸に直交する
方向をｙとしたとき、次の式で表される。 ｘ=(ｙ2/ｒ）／［1+｛1-Ｐ( ｙ2/ｒ2)｝1/2 ］＋A4ｙ4 ＋A6ｙ6 ＋A8ｙ8 ただし、ｒは近軸曲率半径、Ｐは円錐係数、A4、A6、A8
は非球面係数である。Further, in any of the embodiments, an aspherical surface is used for the front surface (r 3 ) of the second positive meniscus lens, and the aspherical shape is a direction orthogonal to the optical axis x and the optical axis. Is represented by the following equation. x = (y 2 / r) / [1+ {1-P (y 2 / r 2)} 1/2] + A 4 y 4 + A 6 y 6 + A 8 y 8 where, r is a paraxial radius of curvature, P Is the conic coefficient, A 4 , A 6 , A 8
Is an aspherical coefficient.
【００１６】 主レンズ系 Ｆ ＝33.9 ＦNO＝3.6 ω ＝32.1° ｒ1 ' = 10.6000 ｄ1 ' = 4.610 ｎd1 ' =1.73400 νd1 ' =51.49 ｒ2 ' = 27.7050 ｄ2 ' = 0.590 ｒ3 ' = -35.2920 ｄ3 ' = 0.800 ｎd2 ' =1.68893 νd2 ' =31.08 ｒ4 ' = 11.2770 ｄ4 ' = 1.540 ｒ5 ' = 41.7410 ｄ5 ' = 1.300 ｎd3 ' =1.79952 νd3 ' =42.24 ｒ6 ' = -21.7810 ｄ6 ' = 1.090 ｒ7 ' = ∞ (絞り) 。Main lens system F = 33.9 F NO = 3.6 ω = 32.1 ° r 1 ' = 10.6000 d 1 ' = 4.610 n d1 ' = 1.73400 ν d1 ' = 51.49 r 2 ' = 27.7050 d 2 ' = 0.590 r 3 ' = -35.2920 d 3 '= 0.800 n d2' = 1.68893 ν d2 '= 31.08 r 4' = 11.2770 d 4 '= 1.540 r 5' = 41.7410 d 5 '= 1.300 n d3' = 1.79952 ν d3 '= 42.24 r 6 ' = -21.7810 d 6 ' = 1.090 r 7 ' = ∞ (aperture).
【００１７】実施例１ Ｆ ＝53.1 ＦNO＝5.7 ω ＝21.7° ｄ0 = 2.000 ｒ1 = -28.2188 ｄ1 = 0.970 ｎd1 =1.69500 νd1 =42.16 ｒ2 = -16.1582 ｄ2 = 2.216 ｒ3 = -15.0580（非球面）ｄ3 = 1.805 ｎd2 =1.58362 νd2 =30.37 ｒ4 = -8.5524 ｄ4 = 0.050 ｒ5 = -8.5454 ｄ5 = 1.810 ｎd3 =1.83481 νd3 =42.72 ｒ6 = -28.4019 非球面係数 第３面 Ｐ＝ 1 A4＝ 0.10533×10-4 A6＝ 0.19734×10-5 A8＝-0.37808×10-7 （Ｒ2 ＋Ｒ1 ）／（Ｒ2 −Ｒ1 ）＝-3.68 Ｄ2 ／｜ｆR ｜ ＝ 0.038 ｆR ・φ23＜０ ＝-0.247 （Ｎ1 ＋Ｎ2 ）／２ ＝ 1.63931
。Example 1 F = 53.1 F NO = 5.7 ω = 21.7 ° d 0 = 2.000 r 1 = -28.2188 d 1 = 0.970 n d1 = 1.69500 ν d1 = 42.16 r 2 = -16.1582 d 2 = 2.216 r 3 = -15.0580 (aspherical surface) d 3 = 1.805 n d2 = 1.58362 ν d2 = 30.37 r 4 = -8.5524 d 4 = 0.050 r 5 = -8.5454 d 5 = 1.810 n d3 = 1.83481 ν d3 = 42.72 r 6 = -28.4019 non Spherical coefficient 3rd surface P = 1 A 4 = 0.10533 × 10 -4 A 6 = 0.19734 × 10 -5 A 8 = -0.37808 × 10 -7 (R 2 + R 1 ) / (R 2 -R 1 ) =-3.68 D 2 / | f R | = 0.038 f R · φ 23 <0 = -0.247 (N 1 + N 2 ) / 2 = 1.63931
..
【００１８】実施例２ Ｆ ＝53.1 ＦNO＝5.7 ω ＝21.8° ｄ0 = 2.000 ｒ1 = -24.2680 ｄ1 = 0.900 ｎd1 =1.69500 νd1 =42.16 ｒ2 = -15.4433 ｄ2 = 2.237 ｒ3 = -16.7986（非球面）ｄ3 = 1.796 ｎd2 =1.58362 νd2 =30.37 ｒ4 = -8.6922 ｄ4 = 0.100 ｒ5 = -8.3137 ｄ5 = 1.799 ｎd3 =1.83481 νd3 =42.72 ｒ6 = -26.7498 非球面係数 第３面 Ｐ＝ 1 A4＝ 0.31916×10-4 A6＝ 0.19846×10-5 A8＝-0.15786×10-7 （Ｒ2 ＋Ｒ1 ）／（Ｒ2 −Ｒ1 ）＝-4.5 Ｄ2 ／｜ｆR ｜ ＝ 0.038 ｆR ・φ23＜０ ＝-0.600 （Ｎ1 ＋Ｎ2 ）／２ ＝ 1.63931
。Example 2 F = 53.1 F NO = 5.7 ω = 21.8 ° d 0 = 2.000 r 1 = -24.2680 d 1 = 0.900 n d1 = 1.69500 ν d1 = 42.16 r 2 = -15.4433 d 2 = 2.237 r 3 = -16.7986 (aspherical surface) d 3 = 1.796 n d2 = 1.58362 ν d2 = 30.37 r 4 = -8.6922 d 4 = 0.100 r 5 = -8.3137 d 5 = 1.799 n d3 = 1.83481 ν d3 = 42.72 r 6 = -26.7498 non Spherical coefficient 3rd surface P = 1 A 4 = 0.31916 × 10 -4 A 6 = 0.19846 × 10 -5 A 8 = -0.15786 × 10 -7 (R 2 + R 1 ) / (R 2 -R 1 ) =-4.5 D 2 / | f R | = 0.038 f R · φ 23 <0 = -0.600 (N 1 + N 2 ) / 2 = 1.63931
..
【００１９】実施例３ Ｆ ＝53.1 ＦNO＝5.7 ω ＝21.8° ｄ0 = 2.000 ｒ1 = -20.6935 ｄ1 = 0.900 ｎd1 =1.69700 νd1 =48.51 ｒ2 = -14.3263 ｄ2 = 2.295 ｒ3 = -20.4951（非球面）ｄ3 = 1.795 ｎd2 =1.58362 νd2 =30.37 ｒ4 = -8.8557 ｄ4 = 0.100 ｒ5 = -8.0503 ｄ5 = 1.786 ｎd3 =1.83481 νd3 =42.72 ｒ6 = -27.0670 非球面係数 第３面 Ｐ＝ 1 A4＝ 0.62294×10-4 A6＝ 0.22996×10-5 A8＝-0.81203×10-8 （Ｒ2 ＋Ｒ1 ）／（Ｒ2 −Ｒ1 ）＝-5.5 Ｄ2 ／｜ｆR ｜ ＝ 0.04 ｆR ・φ23＜０ ＝-1.169 （Ｎ1 ＋Ｎ2 ）／２ ＝ 1.64031
。Example 3 F = 53.1 F NO = 5.7 ω = 21.8 ° d 0 = 2.000 r 1 = -20.6935 d 1 = 0.900 n d1 = 1.69700 ν d1 = 48.51 r 2 = -14.3263 d 2 = 2.295 r 3 = -20.4951 (aspherical surface) d 3 = 1.795 n d2 = 1.58362 ν d2 = 30.37 r 4 = -8.8557 d 4 = 0.100 r 5 = -8.0503 d 5 = 1.786 n d3 = 1.83481 ν d3 = 42.72 r 6 = -27.0670 non surface coefficients third surface P = 1 A 4 = 0.62294 × 10 -4 A 6 = 0.22996 × 10 -5 A 8 = -0.81203 × 10 -8 (R 2 + R 1) / (R 2 -R 1) = - 5.5 D 2 / | f R | = 0.04 f R · φ 23 <0 = -1.169 (N 1 + N 2 ) / 2 = 1.64031
..
【００２０】実施例４ Ｆ ＝53.1 ＦNO＝5.7 ω ＝21.6° ｄ0 = 2.000 ｒ1 = -47.1785 ｄ1 = 0.970 ｎd1 =1.69500 νd1 =42.16 ｒ2 = -15.7262 ｄ2 = 1.244 ｒ3 = -14.2491（非球面）ｄ3 = 1.815 ｎd2 =1.58362 νd2 =30.37 ｒ4 = -8.3467 ｄ4 = 0.050 ｒ5 = -8.3853 ｄ5 = 1.824 ｎd3 =1.83481 νd3 =42.72 ｒ6 = -39.6366 非球面係数 第３面 Ｐ＝ 1 A4＝-0.20828×10-4 A6＝ 0.75071×10-5 A8＝-0.26923×10-6 （Ｒ2 ＋Ｒ1 ）／（Ｒ2 −Ｒ1 ）＝-2.0 Ｄ2 ／｜ｆR ｜ ＝ 0.022 ｆR ・φ23＜０ ＝-0.187 （Ｎ1 ＋Ｎ2 ）／２ ＝ 1.63931
。Example 4 F = 53.1 F NO = 5.7 ω = 21.6 ° d 0 = 2.000 r 1 = -47.1785 d 1 = 0.970 n d1 = 1.69500 ν d1 = 42.16 r 2 = -15.7262 d 2 = 1.244 r 3 = -14.2491 (aspherical surface) d 3 = 1.815 n d2 = 1.58362 ν d2 = 30.37 r 4 = -8.3467 d 4 = 0.050 r 5 = -8.3853 d 5 = 1.824 n d3 = 1.83481 ν d3 = 42.72 r 6 = -39.6366 non third surface P = 1 A 4 = -0.20828 × surface coefficient 10 -4 A 6 = 0.75071 × 10 -5 A 8 = -0.26923 × 10 -6 (R 2 + R 1) / (R 2 -R 1) = - 2.0 D 2 / | f R | = 0.022 f R · φ 23 <0 = -0.187 (N 1 + N 2 ) / 2 = 1.63931
..
【００２１】上記主レンズ系及びこれに実施例１〜４の
リアコンバージョンレンズを装着した状態での無限遠物
体に合焦した時の球面収差、非点収差、歪曲収差を表す
収差図をそれぞれ図３〜図７に示す。Aberration diagrams showing spherical aberration, astigmatism, and distortion when focusing on an object at infinity with the main lens system and the rear conversion lenses of Examples 1 to 4 attached thereto are respectively shown. 3 to 7.
【００２２】[0022]
【発明の効果】以上の説明から明らかなように、本発明
のリアコンバージョンレンズは、画角域の広画角化に対
応したものであり、変倍比約１．６程度で、良好な光学
性能を有しながら、構成枚数を３枚としたことにより、
小型化を損なわないものとなっている。As is apparent from the above description, the rear conversion lens of the present invention is compatible with widening of the angle of view in the field of view, and has a variable power ratio of about 1.6 and excellent optical characteristics. By having three components while maintaining performance,
It does not impair miniaturization.
【図１】本発明のリアコンバージョンレンズを装着する
主レンズ系の１例の断面図である。FIG. 1 is a sectional view of an example of a main lens system to which a rear conversion lens of the present invention is attached.
【図２】本発明の実施例１のリアコンバージョンレンズ
を図１の主レンズ系に装着した状態での断面図である。FIG. 2 is a cross-sectional view of the rear conversion lens of Example 1 of the present invention mounted on the main lens system of FIG.
【図３】図１の主レンズ系の球面収差、非点収差、歪曲
収差を表す収差図である。FIG. 3 is an aberration diagram showing spherical aberration, astigmatism, and distortion of the main lens system of FIG.
【図４】実施例１のリアコンバージョンレンズを図１の
主レンズ系に装着した状態での図３と同様な収差図であ
る。FIG. 4 is an aberration diagram similar to that of FIG. 3 when the rear conversion lens of Example 1 is mounted on the main lens system of FIG.
【図５】実施例２についての図４と同様な収差図であ
る。FIG. 5 is an aberration diagram similar to FIG. 4 for Example 2.
【図６】実施例３についての図４と同様な収差図であ
る。FIG. 6 is an aberration diagram similar to FIG. 4 for Example 3.
【図７】実施例４についての図４と同様な収差図であ
る。FIG. 7 is an aberration diagram similar to FIG. 4 for Example 4.
ＭＬ …主レンズ系 ＲＣＬ…リアコンバーターレンズ ML ... Main lens system RCL ... Rear converter lens
Claims (1)
れ、その挿脱に伴って全系の焦点距離を変化させる負の
屈折力のリアコンバージョンレンズにおいて、主レンズ
側から順に、像側に凸面を向けた正メニスカスレンズの
第１レンズと、正レンズの第２レンズと、負レンズの第
３レンズとからなると共に、以下の条件（１）、（２）
を満足することを特徴とするリアコンバージョンレン
ズ： （１）−６．０＜（Ｒ2 ＋Ｒ1 ）／（Ｒ2 −Ｒ1 ）＜−２．０ （２）０．０２＜Ｄ2 ／｜ｆR ｜ ＜０．０５ ただし、ここで、Ｒ1 、Ｒ2 はそれぞれ前記第１レンズ
の前面、後面の曲率半径、Ｄ2 は前記第１レンズと第２
レンズの軸上間隔、ｆR は前記リアコンバージョンレン
ズ全系の焦点距離である。1. A rear conversion lens having a negative refractive power, which is removably disposed on the image plane side of a main lens system and changes the focal length of the entire system with the insertion / removal, in order from the main lens side. The first lens is a positive meniscus lens having a convex surface facing the image side, the second lens is a positive lens, and the third lens is a negative lens, and the following conditions (1) and (2) are satisfied.
And satisfying the rear conversion lens: (1) -6.0 <(R 2 + R 1) / (R 2 -R 1) <- 2.0 (2) 0.02 <D 2 / | f R ｜ <0.05, where R 1 and R 2 are the radii of curvature of the front surface and the rear surface of the first lens, respectively, and D 2 is the first lens and the second lens.
The axial distance of the lens, f R, is the focal length of the entire rear conversion lens system.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4154787A JPH05346541A (en) | 1992-06-15 | 1992-06-15 | Rear conversion lens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4154787A JPH05346541A (en) | 1992-06-15 | 1992-06-15 | Rear conversion lens |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05346541A true JPH05346541A (en) | 1993-12-27 |
Family
ID=15591894
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4154787A Withdrawn JPH05346541A (en) | 1992-06-15 | 1992-06-15 | Rear conversion lens |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05346541A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013235217A (en) * | 2012-05-11 | 2013-11-21 | Olympus Imaging Corp | Teleconverter and image capturing system equipped with the same |
-
1992
- 1992-06-15 JP JP4154787A patent/JPH05346541A/en not_active Withdrawn
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013235217A (en) * | 2012-05-11 | 2013-11-21 | Olympus Imaging Corp | Teleconverter and image capturing system equipped with the same |
| US9075291B2 (en) | 2012-05-11 | 2015-07-07 | Olympus Imaging Corp. | Teleconverter, and imaging system comprising the same |
| US9563106B2 (en) | 2012-05-11 | 2017-02-07 | Olympus Corporation | Teleconverter mounted on a master lens apparatus to obtain a lens system having a focal length longer than that of the master lens apparatus, and imaging system comprising the same |
| US9904030B2 (en) | 2012-05-11 | 2018-02-27 | Olympus Corporation | Teleconverter, and imaging system comprising the same |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 19990831 |