JP5526961B2 - Objective lens system for parallel stereo microscope, parallel stereo microscope - Google Patents
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Description
本発明は、平行系実体顕微鏡用の対物レンズ系に関する。 The present invention relates to an objective lens system for a parallel stereomicroscope.
実体顕微鏡は、凹凸のある物体を観察した場合、両目で見た場合と同じように立体感を持って観察できる。このため、顕微鏡下で作業する場合にピンセット等の工具と物体との距離関係を容易に把握することができる。したがって、精密機械工業、生物の解剖、手術等細かい処置が必要な分野で特に有効である。実体顕微鏡では、物体の立体感のための視差を得るため、左右二つの眼に入射する光束の光学系を少なくとも部分的には独立させ、その光軸が物体面上で交わるようにする。そして、異なった方向より見た物体の拡大像を作り、接眼レンズを通して観察することで微小物体の立体視を行っている。実体顕微鏡の立体視を得る代表的方法として、平行系実体顕微鏡が挙げられる。平行系実体顕微鏡は、一つの対物レンズ系と、該対物レンズ系の光軸に平行に配置された右眼用と左眼用との二つの観察光学系を有している。このような平行系実体顕微鏡用対物レンズ系として、例えば、下記の特許文献1,2に記載されたものが開示されている。
With a stereomicroscope, when an uneven object is observed, it can be observed with a three-dimensional effect in the same way as when viewed with both eyes. For this reason, when working under a microscope, it is possible to easily grasp the distance relationship between a tool such as tweezers and an object. Therefore, it is particularly effective in fields requiring fine treatment such as precision machine industry, biological dissection, and surgery. In a stereomicroscope, in order to obtain a parallax for a three-dimensional effect of an object, the optical systems of light beams incident on the left and right eyes are at least partially independent so that their optical axes intersect on the object plane. Then, a magnified image of the object viewed from different directions is created and observed through an eyepiece to stereoscopically view the minute object. As a typical method for obtaining a stereoscopic view of a stereomicroscope, a parallel stereomicroscope can be cited. The parallel system stereomicroscope has one objective lens system and two observation optical systems for the right eye and for the left eye arranged in parallel to the optical axis of the objective lens system. As such an objective lens system for a parallel stereomicroscope, for example, those described in
平行系実体顕微鏡では、対物レンズ系を通過する光束が右眼用観察光学系と左眼用観察光学系とで偏心していることが、左右の見え方に差を生じさせる要因となっている。このため、右眼用観察光学系と左眼用観察光学系とがそれぞれ有する歪曲収差の量が異なる場合、又は各光学系が有する歪曲収差の絶対量そのものが大きい場合等は、非対称に歪んだ特有な観察像が左右の観察光学系で生じる。そして、これらの像が観察者において融合、即ち融像されると、物体の奥行き知覚を狂わせるため凸面感等の歪みとなって現れる。例えば、最もその影響が顕著な例として、平坦な標本を観察した場合に、観察像が平坦ではなく凸面状に盛り上がって見えてしまい、観察者に違和感を与えるという現象が挙げられる。また、像の中心付近と、周辺との歪曲収差量の変化率が大きいと、像の歪みが強調され像の平坦性を悪化せる原因の一つとなる。 In the parallel system stereomicroscope, the fact that the light beam passing through the objective lens system is decentered between the observation optical system for the right eye and the observation optical system for the left eye is a factor causing a difference in the left and right appearance. For this reason, when the right-eye observation optical system and the left-eye observation optical system have different amounts of distortion, or when the absolute amount of distortion aberration of each optical system itself is large, the distortion is asymmetrically distorted. A unique observation image is generated in the left and right observation optical systems. When these images are fused, that is, fused by the observer, the depth perception of the object is distorted and appears as distortion such as convexity. For example, as an example in which the influence is most prominent, there is a phenomenon in which when a flat specimen is observed, the observation image appears to be convex rather than flat, giving the viewer a sense of incongruity. In addition, if the rate of change in the amount of distortion between the vicinity of the center of the image and the periphery is large, the distortion of the image is emphasized, which is one of the causes of deterioration of the flatness of the image.
このため、実体顕微鏡では歪曲収差の絶対量が少ない方が望ましいことに加えて、さらに左右の観察光学系での歪曲収差量の差や、像高による歪曲収差の差など絶対量のみならずその質的な収差量にまで配慮することが好ましい。また、歪曲収差だけでなく、上述の問題を踏まえた上で、その他の諸収差(球面収差、非点収差、像面湾曲など)をバランス良く補正する必要があることは言うまでもない。さらに、実体顕微鏡の場合、変倍光学系を併用するのが一般的であるので、変倍に伴う視野領域の変化、又は開口数の変化に対応した収差補正が必要となる。 For this reason, it is desirable that the stereo microscope has a smaller absolute amount of distortion. In addition to the absolute amount such as the difference in distortion between the left and right observation optical systems and the difference in distortion due to image height, It is preferable to consider qualitative aberrations. Needless to say, other aberrations (spherical aberration, astigmatism, curvature of field, etc.) need to be corrected in a well-balanced manner in consideration of the above-described problems as well as distortion. Furthermore, in the case of a stereomicroscope, since it is common to use a variable magnification optical system, aberration correction corresponding to a change in the visual field region or a change in the numerical aperture due to the variable magnification is required.
本発明は、このような問題に鑑みてなされたものであり、変倍域を拡大しても歪曲収差を実用上問題の無い程度に抑え、像面の平坦性を確保するとともに、対物レンズの大型化を避け、その他の諸収差も良好に補正し、優れた結像性能を実現することが可能な平行系実体顕微鏡用の対物レンズ系及びこれを備えた平行系実体顕微鏡を提供することを目的とする。 The present invention has been made in view of such a problem, and even if the zooming range is expanded, distortion is suppressed to a level that does not cause a problem in practice, and the flatness of the image surface is ensured. To provide an objective lens system for a parallel stereo microscope capable of avoiding upsizing and correcting other various aberrations well and realizing excellent imaging performance, and a parallel stereo microscope equipped with the objective lens system Objective.
このような目的を達成するため、本発明に係る平行系実体顕微鏡用対物レンズ系は、物体から遠い側より順に並んだ、負の屈折力を持つ接合レンズを含み、全体として正の屈折力を持つ第1レンズ群と、物体側に凸面を向けたメニスカス形状の負の屈折力を持つレンズと、正の屈折力を持つ接合レンズとを含む第2レンズ群と、少なくとも1枚の正の屈折力を持つ単レンズを含み、全体として正の屈折力を持つ第3レンズ群とから構成される平行系実体顕微鏡用対物レンズ系であって、前記第1レンズ群を構成する前記負の屈折力を持つ接合レンズの焦点距離をfB1とし、前記対物レンズ系全系の焦点距離をfとしたとき、次式
5.00 < (−fB1)/f < 20.00
の条件を満足し、前記第2レンズ群の焦点距離をf2としたとき、次式
6.00 < |f2/f|
の条件も満足する。
In order to achieve such an object, an objective lens system for a parallel stereomicroscope according to the present invention includes a cemented lens having negative refractive power arranged in order from a side far from an object, and has a positive refractive power as a whole. A first lens group, a second lens group including a meniscus lens having a negative refractive power with a convex surface facing the object side, and a cemented lens having a positive refractive power, and at least one positive refraction An objective lens system for a parallel stereomicroscope including a third lens group having a positive refracting power as a whole, including a single lens having power, and the negative refracting power constituting the first lens group When the focal length of the cemented lens having f is fB1 and the focal length of the entire objective lens system is f,
5.00 <(− fB1) / f <20.00
And when the focal length of the second lens group is f2,
6.00 <| f2 / f |
This condition is also satisfied .
なお、本発明において、前記第1レンズ群は正の屈折力を持つ単レンズを有し、この第1レンズ群を構成する前記正の屈折力を持つ単レンズのアッベ数をνdL1としたとき、次式 νdL1 <40.0 の条件を満足することが好ましい。 In the present invention, the first lens group has a single lens having a positive refractive power, and when the Abbe number of the single lens having the positive refractive power constituting the first lens group is νdL1, It is preferable that the condition of the following formula νdL1 <40.0 is satisfied.
また、本発明において、前記第2レンズ群を構成する、前記物体側に凸面を向けたメニスカス形状の負の屈折力を持つレンズは、負レンズと正レンズとを貼り合わせた接合メニスカスレンズであり、前記正の屈折力を持つ接合レンズは、両凸レンズと両凹レンズと両凸レンズの3枚を貼り合わせた接合レンズであることが好ましい。 In the present invention, the meniscus lens having a negative refractive power that forms the second lens group and has a convex surface facing the object side is a cemented meniscus lens in which a negative lens and a positive lens are bonded together. The cemented lens having a positive refractive power is preferably a cemented lens in which three lenses of a biconvex lens, a biconcave lens, and a biconvex lens are bonded together.
本発明に係る平行系実体顕微鏡において、前記第2レンズ群は、異なる光学材料からなる二つの回折素子要素を接合し、当該接合面に回折格子溝が形成された回折光学面を有する密着複層型回折光学素子を有することが好ましい。この場合、前記異なる光学材料からなる二つの回折素子要素のうち、低屈折率高分散の方の前記回折光学素子の光学材料のd線,F線,C線に対する屈折率をそれぞれnd1,nF1,nC1とし、高屈折率低分散の方の前記回折光学素子の光学材料のd線,F線,C線に対する屈折率をそれぞれnd2,nF2,nC2とし、前記回折光学素子の回折光学面の有効径をφLDとし、前記対物レンズ系の左右片側の最大射出瞳径をφAP(この最大射出瞳径は後述する観察光学系の最大入射瞳径と同一であり、両者をφAPで表す)としたとき、次式nd1≦1.54、0.0145≦nF1−nC1、1.55≦nd2、nF2−nC2≦0.0130及び2.2≦φLD/φAPの条件を満足することが好ましい。 In the parallel-system stereomicroscope according to the present invention, the second lens group includes a diffractive optical surface having a diffractive optical surface in which two diffractive element elements made of different optical materials are bonded and a diffraction grating groove is formed on the bonded surface. It is preferable to have a type diffractive optical element . In this case, of the two diffractive element elements made of the different optical materials, the refractive indices of the optical material of the diffractive optical element having the lower refractive index and higher dispersion for the d-line, F-line, and C-line are nd1, nF1, respectively. nC1, and the refractive index of the optical material of the diffractive optical element with the higher refractive index and lower dispersion with respect to the d-line, F-line, and C-line are nd2, nF2, and nC2, respectively, and the effective diameter of the diffractive optical surface of the diffractive optical element Is φLD, and the maximum exit pupil diameter on the left and right sides of the objective lens system is φAP (this maximum exit pupil diameter is the same as the maximum entrance pupil diameter of the observation optical system described later, and both are represented by φAP) . It is preferable to satisfy the following conditions: nd1 ≦ 1.54, 0.0145 ≦ nF1-nC1, 1.55 ≦ nd2, nF2-nC2 ≦ 0.0130, and 2.2 ≦ φLD / φAP.
本発明に係る平行系実体顕微鏡は、上記のいずれかに記載の前記平行系実体顕微鏡用対物レンズ系と、前記平行系実体顕微鏡用対物レンズ系の物体側と反対側の面に対向し、前記平行系実体顕微鏡用対物レンズ系の光軸を挟んで並列配置され、前記対物レンズ系により物体からの光を平行光束に変換された光を受光する左眼用と右眼用の二つの観察光学系とを備えて構成される。 A parallel system stereomicroscope according to the present invention is opposed to the object lens system for the parallel system stereomicroscope according to any one of the above, and a surface opposite to the object side of the objective lens system for the parallel system stereomicroscope, Two observation optics for the left eye and the right eye, which are arranged in parallel across the optical axis of an objective lens system for a parallel stereo microscope, and receive light obtained by converting light from an object into a parallel light beam by the objective lens system System .
このように構成される平行系実体顕微鏡において、前記観察光学系が、変倍光学系を含み、前記変倍光学系のズーム最高倍での対物側軸間距離をSBH(単位:mm)とし、前記変倍光学系のズーム最低倍での対物側軸間距離をSBL(単位:mm)としたとき、次式
1mm ≦ SBH−SBL ≦ 10mm
の条件を満足し、
前記観察光学系の最大入射瞳径をφAP(単位:mm)とし、前記対物レンズ系の観察可能な最大物体高をYmaxとしたとき、次式
23mm ≦ φAP ≦ 30mm
0.160 ≦ Ymax/f
の条件を満足することが好ましい。
In the parallel stereo microscope configured as described above, the observation optical system includes a variable magnification optical system, and the distance between the objective side axes at the zoom maximum magnification of the variable magnification optical system is SBH (unit: mm) , When the distance between the objective-side axes at the zoom minimum magnification of the variable magnification optical system is SBL (unit: mm) , the
Satisfy the conditions of
When the maximum entrance pupil diameter of the observation optical system is φAP (unit: mm) and the maximum object height that can be observed by the objective lens system is Ymax, the following expression is given: 23 mm ≦ φAP ≦ 30 mm
0.160 ≤ Ymax / f
It is preferable to satisfy the following conditions.
本発明によれば、歪曲収差を実用上問題の無い程度に抑え、像面の平坦性を確保するとともに、その他の諸収差も良好に補正することにより、優れた結像性能を実現することが可能な平行系実体顕微鏡用対物レンズ系及びこれを備えた平行系実体顕微鏡を提供することができる。 According to the present invention, it is possible to realize excellent imaging performance by suppressing distortion aberration to a practically no problem level, ensuring flatness of the image surface, and correcting other various aberrations well. An object lens system for a parallel system stereomicroscope and a parallel system stereomicroscope including the same can be provided.
以下、本実施形態について、図面を用いて説明する。まず、本実施形態に係る対物レンズ系を備える、平行系実体顕微鏡(平行系単対物型双眼顕微鏡)について説明する。本実施形態に係る平行系実体顕微鏡は、図1に示すように、物体Obから焦点距離fの位置に配置されている一つの対物レンズ系Lobと、対物レンズ系Lobの光軸AXobに平行に配置された右眼用観察光学系LRと左眼用観察光学系LLとを有する。右眼用観察光学系LRは、物体Ob側から順に並んだ、アフォーカルな変倍光学系(ズーム光学系)LZRと、物体の中間像を形成する結像光学系LIRと、中間像を拡大する接眼光学系LERとから構成されている。左眼用観察光学系LLも同様の構成である。そして、物体Obからの光は、対物レンズ系Lobにより平行光束に変換され、変倍光学系LZR,LZLを介して、結像光学系LIR,LILにより中間像が形成され、接眼光学系LER,LELにより中間像は拡大され、最終像を所定のアイポイント位置において図示しない肉眼で観察する構成となっている。このような構成の平行系実体顕微鏡では、右眼用観察光学系LRの光軸AXR及び左眼用観察光学系LLのAXLが、それぞれ対物レンズ系Lobの光軸AXobに対して物体面において所定角度θだけ傾いている。この視差により、物体Obを立体的に観察することができるようになっている。 Hereinafter, the present embodiment will be described with reference to the drawings. First, a parallel stereo microscope (parallel single objective binocular microscope) including the objective lens system according to the present embodiment will be described. Parallel system stereomicroscope according to the present embodiment, as shown in FIG. 1, and one objective lens system L ob disposed from the object Ob to the position of the focal length f, of the objective lens system L ob optical axis AX ob and an observation optical system L L for parallel arranged right-eye observation optical system L R and the left eye in. The right-eye observation optical system LR includes an afocal zoom optical system L ZR arranged in order from the object Ob side, an imaging optical system L IR that forms an intermediate image of the object, and an intermediate and an eyepiece optical system L ER to expand the image. The left-eye observation optical system LL has the same configuration. The light from the object Ob is converted into a parallel light beam by the objective lens system L ob , and an intermediate image is formed by the imaging optical systems L IR and L IL via the variable magnification optical systems L ZR and L ZL . The intermediate image is enlarged by the eyepiece optical systems L ER and L EL , and the final image is observed with the naked eye (not shown) at a predetermined eye point position. The parallel system stereomicroscope having such a configuration, AX L of the optical axis AX R and the left-eye observation optical system L L of the right-eye observation optical system L R is the optical axis AX ob of the objective lens system L ob respectively In contrast, the object surface is inclined by a predetermined angle θ. With this parallax, the object Ob can be observed stereoscopically.
本実施形態において、上記対物レンズ系Lobは、図2に示すように、物体Obから遠い側(すなわち図1の観察光学系LR,LL側)より順に並んだ、負の屈折力を持つ接合レンズB1を含み、全体として正の屈折力を持つ第1レンズ群G1と、物体側に凸面を向けたメニスカス形状の負の屈折力を持つレンズ(図2ではレンズL21,L22からなる接合レンズが該当)と、正の屈折力を持つ接合レンズ(図2ではレンズL23,L24,L25からなる3枚接合レンズが該当)とを含み、弱い屈折力を持つ第2レンズ群G2と、少なくとも1枚の正の屈折力を持つ単レンズ(図2ではレンズL31,L32がそれぞれ該当)を含み、全体として正の屈折力を持つ第3レンズ群G3とから構成されている。この構成により、ズーム低倍時の倍率色収差、歪曲収差及び像面収差を効率良く補正することができる。 In the present embodiment, the objective lens system L ob has negative refractive powers arranged in order from the side far from the object Ob (that is, the observation optical system L R , L L side in FIG. 1), as shown in FIG. A first lens group G1 having a positive refractive power as a whole and a meniscus-shaped lens having a negative refractive power with the convex surface facing the object side (in FIG. 2, a cemented lens comprising lenses L21 and L22). A second lens group G2 having a weak refractive power, and a cemented lens having a positive refractive power (corresponding to a three-lens cemented lens including lenses L23, L24, and L25 in FIG. 2), and at least It includes a single lens having a positive refractive power (lens L31 and L32 in FIG. 2 respectively) and a third lens group G3 having a positive refractive power as a whole. With this configuration, it is possible to efficiently correct lateral chromatic aberration, distortion aberration, and image plane aberration at the time of zoom low magnification.
そして、上記構成の基、第1レンズ群G1を構成する負の屈折力を持つ接合レンズB1の焦点距離をfB1とし、対物レンズ系Lobの全系の焦点距離をfとし、以下の条件式(1)を満足する。 Then, based on the above configuration, the focal length of the cemented lens B1 having negative refractive power constituting the first lens group G1 is fB1, the focal length of the entire objective lens system L ob is f, and the following conditional expression Satisfy (1).
1.00 < (−fB1)/f < 20.00 …(1) 1.00 <(− fB1) / f <20.00 (1)
上記条件式(1)は、第1レンズ群G1を構成する、負の屈折力を持つ接合レンズB1の焦点距離の適切な範囲を規定している。この条件式(1)の上限値を上回ると、接合レンズB1の負の屈折力が弱くなり、ズーム低倍時の像面湾曲や歪曲収差の補正が困難となる。逆に、条件式(1)の下限値を下回ると、光線の高さが大きくなりすぎ、特に球面収差の補正が困難となる。 The conditional expression (1) defines an appropriate range of the focal length of the cemented lens B1 having a negative refractive power and constituting the first lens group G1. When the upper limit of conditional expression (1) is exceeded, the negative refractive power of the cemented lens B1 becomes weak, and it becomes difficult to correct curvature of field and distortion at zoom low magnification. On the other hand, if the lower limit value of conditional expression (1) is not reached, the height of the light beam becomes too large, and it becomes particularly difficult to correct spherical aberration.
なお、本実施形態の効果を確実なものとするために、条件式(1)の下限値を5.00とすることが好ましい。また、本実施形態の効果を確実なものとするために、条件式(1)の上限値を9.00とすることが好ましい。 In order to secure the effect of the present embodiment, it is preferable to set the lower limit of conditional expression (1) to 5.00. In order to secure the effect of the present embodiment, it is preferable to set the upper limit of conditional expression (1) to 9.00.
なお、本実施形態の対物レンズ系Lobは、第1レンズ群G1の焦点距離をf1とし、第3レンズ群G3の焦点距離をf3としたとき、以下の条件式(2)及び(3)を満足することがより好ましい。
1.50 < f1/f <5.00 …(2)
1.00 < f3/f <1.50 …(3)
In the objective lens system L ob of the present embodiment, when the focal length of the first lens group G1 is f1, and the focal length of the third lens group G3 is f3, the following conditional expressions (2) and (3) Is more preferable.
1.50 <f1 / f <5.00 (2)
1.00 <f3 / f <1.50 (3)
上記条件式(2)は、第1レンズ群G1の焦点距離の適切な範囲を規定している。この条件式(2)の上限値を上回ると、第1レンズ群G1の正の屈折力が弱くなり、光線の高さが大きくなりすぎて、球面収差の補正が困難となる。逆に、条件式(2)の下限値を下回ると、主点位置が物体面から遠くなり、十分な作動距離が得られなくなる。 Conditional expression (2) defines an appropriate range of the focal length of the first lens group G1. If the upper limit value of conditional expression (2) is exceeded, the positive refractive power of the first lens group G1 becomes weak, the height of the light beam becomes too large, and it becomes difficult to correct spherical aberration. On the contrary, if the lower limit value of conditional expression (2) is not reached, the principal point position becomes far from the object surface, and a sufficient working distance cannot be obtained.
なお、本実施形態の効果を確実なものとするために、条件式(2)の下限値を2.00とすることが好ましい。また、本実施形態の効果を確実なものとするために、条件式(2)の上限値を3.50とすることが好ましい。 In order to secure the effect of the present embodiment, it is preferable to set the lower limit value of conditional expression (2) to 2.00. In order to secure the effect of the present embodiment, it is preferable to set the upper limit of conditional expression (2) to 3.50.
上記条件式(3)は、第3レンズ群G3の焦点距離の適切な範囲を規定している。この条件式(3)の上限値を上回ると、第3レンズ群G3の正の屈折力が弱くなるため、結果として第2レンズ群G2の屈折力を強めることになり、色収差の補正が困難となる。逆に、条件式(3)の下限値を下回ると、作動距離が短くなるだけでなく、ズーム低倍時での非点収差や歪曲収差の補正が困難となる。 Conditional expression (3) defines an appropriate range of the focal length of the third lens group G3. If the upper limit value of the conditional expression (3) is exceeded, the positive refractive power of the third lens group G3 becomes weak. As a result, the refractive power of the second lens group G2 is increased, and it is difficult to correct chromatic aberration. Become. On the other hand, if the lower limit of conditional expression (3) is not reached, the working distance is shortened, and correction of astigmatism and distortion at zoom low magnification becomes difficult.
なお、本実施形態の効果を確実なものとするために、条件式(3)の下限値を1.10とすることが好ましい。また、本実施形態の効果を確実なものとするために、条件式(3)の上限値を1.30とすることが好ましい。 In order to secure the effect of the present embodiment, it is preferable to set the lower limit of conditional expression (3) to 1.10. In order to secure the effect of the present embodiment, it is preferable to set the upper limit of conditional expression (3) to 1.30.
また、本実施形態に係る対物レンズ系Lobは、第1レンズ群G1は正の屈折力を持つ単レンズ(図2ではレンズL11が該当)を有し、この第1レンズ群G1を構成する正の屈折力を持つ単レンズのアッベ数をνdL1としたとき、以下の条件式(4)を満足することが好ましい。 In the objective lens system L ob according to the present embodiment, the first lens group G1 has a single lens having a positive refractive power (the lens L11 corresponds to FIG. 2), and constitutes the first lens group G1. When the Abbe number of a single lens having positive refractive power is νdL1, it is preferable that the following conditional expression (4) is satisfied.
νdL1 <40.0 …(4) νdL1 <40.0 (4)
上記条件式(4)は、第1レンズ群G1を構成する正の屈折力を持つ単レンズの硝材のアッベ数の適切な範囲を規定している。この条件式(4)の上限値を上回ると、第1レンズ群G1での色出し効果が薄れ、ズーム低倍時の倍率色収差、及び、ズーム高倍時の色の球面収差やコマ収差の補正が困難となる。 Conditional expression (4) defines an appropriate range of the Abbe number of a single lens glass material having a positive refractive power constituting the first lens group G1. If the upper limit value of the conditional expression (4) is exceeded, the color development effect in the first lens group G1 will be reduced, and the lateral chromatic aberration at zoom low magnification, and the spherical aberration and coma aberration of color at zoom high magnification will be corrected. It becomes difficult.
なお、本実施形態の効果を確実なものとするために、条件式(2)の上限値を30.0とすることが好ましい。 In order to secure the effect of the present embodiment, it is preferable to set the upper limit of conditional expression (2) to 30.0.
また、本実施形態に係る対物レンズ系Lobは、第2レンズ群G2を構成する、前記物体側に凸面を向けたメニスカス形状の負の屈折力を持つレンズは、負レンズと正レンズとを貼り合わせた接合メニスカスレンズ(図2ではレンズL21,L22からなる接合レンズが該当)であり、前記正の屈折力を持つ接合レンズは、両凸レンズと両凹レンズと両凸レンズの3枚を貼り合わせた接合レンズ(図2ではレンズL23,L24,L25からなる3枚接合レンズが該当)であることが好ましい。この構成によれば、本光学系において径が最大のところに色消し接合レンズを配置することができるため、ズーム高倍時の球面収差と軸上色収差を効率良く補正することができる。 In addition, the objective lens system L ob according to the present embodiment includes a negative lens and a positive lens, which form the second lens group G2, and a meniscus lens having a negative refractive power facing the object side. A cemented meniscus lens (a cemented lens composed of lenses L21 and L22 in FIG. 2 is applicable), and the cemented lens having positive refractive power is composed of a biconvex lens, a biconcave lens, and a biconvex lens. It is preferably a cemented lens (in FIG. 2, a three-lens cemented lens composed of lenses L23, L24, and L25 is applicable). According to this configuration, since the achromatic cemented lens can be disposed at the maximum diameter in the present optical system, it is possible to efficiently correct spherical aberration and axial chromatic aberration at the time of zoom high magnification.
また、本実施形態に係る対物レンズ系Lobは、物体Obからの光を平行光束に変換し、その後に続く左眼用と右眼用の二つの観察光学系LR,LLに前記光束を導くことにより、立体視を可能にするものであり、図8に示すように、前記観察光学系LR,LLは、変倍光学系LZR,LZL、結像光学系LIR,LIL、接眼光学系LER,LELを含み、変倍光学系LZR,LZLのズーム最高倍での対物側軸間距離をSBHとし、変倍光学系LZR,LZLのズーム最低倍での対物側軸間距離をSBLとする偏心変倍光学系であり、以下の条件式(5)を満足する場合、前記対物レンズ系Lobの左右片側の最大射出瞳径をφAPとし、前記対物レンズ系Lobの観察可能な最大物体高をYmaxとしたとき、以下の条件式(6)及び(7)を満足することが好ましい。なお、図8中では、観察光学系LR,LLの対物側光軸間距離をSBとしたとき、SB=SBH,SBL<SBの状態を示している。ここで、偏心変倍光学系とは、複数のレンズ群から構成され、高倍端から低倍端へ変倍する区間の少なくとも一部において、複数のレンズ群のうちの少なくとも2つのレンズ群がそれぞれ対物レンズ系の光軸と直交する方向の成分を持つように移動するものをいう。 Further, the objective lens system L ob according to the present embodiment converts the light from the object Ob into a parallel light beam, and then transmits the light beam to the subsequent two observation optical systems L R and L L for the left eye and the right eye. As shown in FIG. 8, the observation optical systems L R and L L are variable magnification optical systems L ZR and L ZL , and imaging optical systems L IR , L IL, ocular optical system L ER, include L EL, the variable magnification optical system L ZR, the objective-side center distance between the zoom up times L ZL and SBH, variable power optical system L ZR, the zoom lowest L ZL the objective-side axial distance at times a decentered variable magnification optical system according to SBL, when satisfying the following conditional expression (5), the maximum exit pupil diameter of the left and right side of the objective lens system L ob and FaiAP, when the Ymax observable maximum object height of the objective lens system L ob, preferably to satisfy the following conditional expression (6) and (7) Yes. In FIG. 8, when the distance between the objective-side optical axes of the observation optical systems L R and L L is SB, the state of SB = SBH and SBL <SB is shown. Here, the decentered variable magnification optical system is composed of a plurality of lens groups, and at least two lens groups of the plurality of lens groups are respectively provided in at least a part of a section where magnification is changed from the high magnification end to the low magnification end. A lens that moves so as to have a component in a direction orthogonal to the optical axis of the objective lens system.
1 ≦ SBH−SBL ≦ 10 …(5)
23 ≦ φAP ≦ 30 …(6)
0.160 ≦ Ymax/f …(7)
1 ≦ SBH−SBL ≦ 10 (5)
23 ≦ φAP ≦ 30 (6)
0.160 ≦ Ymax / f (7)
上記条件式(5)は、ズーム高倍時とズーム低倍時とにおける左右の観察光学系LR,LLの対物側光軸間距離の差の適切な量を規定している。この条件式(5)の上限値を上回ると、ズーム低倍時に左右の観察光学系LR,LLの対物側光軸間距離が狭くなりすぎ、十分なステレオ効果が得られなくなったり、ズーム高倍時に左右の観察光学系LR,LLの対物側光軸間距離が広くなりすぎ、観察する際の接眼光学系LER,LELの眼幅に合わなくなったりする。逆に、条件式(5)の下限値を下回ると、ズーム低倍時に対物レンズ系Lobが巨大化する。 Conditional expression (5) defines an appropriate amount of the difference in the distance between the objective-side optical axes of the left and right observation optical systems L R and L L when the zoom is at high magnification and at zoom low magnification. If the upper limit of this conditional expression (5) is exceeded, the distance between the objective-side optical axes of the left and right observation optical systems L R and L L becomes too narrow when zooming is low, and a sufficient stereo effect cannot be obtained or zooming is performed. At the time of high magnification, the distance between the objective-side optical axes of the left and right observation optical systems L R and L L becomes too large, and may not fit the eye width of the eyepiece optical systems L ER and L EL at the time of observation. On the other hand, if the lower limit value of conditional expression (5) is not reached, the objective lens system L ob becomes large when the zoom is low.
なお、本実施形態の効果を確実なものとするために、条件式(5)の下限値を4以上とすることが好ましい。また、本実施形態の効果を確実なものとするために、条件式(5)の上限値を8以下とすることが好ましい。 In order to secure the effect of the present embodiment, it is preferable to set the lower limit of conditional expression (5) to 4 or more. In order to secure the effect of the present embodiment, it is preferable to set the upper limit of conditional expression (5) to 8 or less.
上記条件式(6)は、対物レンズ系Lobの左右片側の最大射出瞳径、言い換えれば左右の観察光学系LR,LLの最大入射瞳径の適切な大きさを規定している。この条件式(6)の上限値を上回ると、左右の観察光学系LR,LLの対物側光軸間距離が大きくなりすぎ、観察する際の接眼光学系LER,LELの眼幅に合わなくなる。逆に、条件式(6)の下限値を下回ると、ズーム高倍時に十分な大きさのNAが得られなくなり、従来製品からの解像力の向上が困難となる。 Conditional expression (6) defines an appropriate size of the maximum exit pupil diameter on one of the left and right sides of the objective lens system L ob , in other words, the maximum entrance pupil diameter of the left and right observation optical systems L R and L L. If the upper limit of conditional expression (6) is exceeded, the distance between the objective optical axes of the left and right observation optical systems L R and L L becomes too large, and the eye width of the eyepiece optical systems L ER and L EL when observing Will not fit. On the other hand, if the lower limit value of conditional expression (6) is not reached, a sufficiently large NA cannot be obtained at zoom high magnification, and it becomes difficult to improve the resolution from the conventional product.
なお、本実施形態の効果を確実なものとするために、条件式(6)の下限値を24以上とすることが好ましい。また、本実施形態の効果を確実なものとするために、条件式(6)の上限値を28以下とすることが好ましい。 In order to secure the effect of the present embodiment, it is preferable to set the lower limit of conditional expression (6) to 24 or more. In order to secure the effect of the present embodiment, it is preferable to set the upper limit of conditional expression (6) to 28 or less.
上記条件式(7)は、対物レンズ系Lobで観察が可能となる適切な画角を規定している。この条件式(7)の下限値を下回ると、ズーム低倍時に観察可能となる十分な大きさの実視野の確保が困難となる。 Conditional expression (7) defines an appropriate angle of view that enables observation with the objective lens system Lob . If the lower limit of conditional expression (7) is not reached, it will be difficult to secure a sufficiently large real field of view that can be observed when the zoom is low.
なお、本実施形態の効果を確実なものとするために、条件式(7)の下限値を0.200以上とすることが好ましい。 In order to secure the effect of the present embodiment, it is preferable to set the lower limit of conditional expression (7) to 0.200 or more.
また、本実施形態に係る対物レンズ系Lobは、図6に示すように、第2レンズ群G2が、異なる光学材料からなる二つの回折素子要素を接合し、当該接合面に回折格子溝が形成された回折光学面Dを有する密着複層型回折光学素子LDを有し、異なる光学材料からなる二つの回折素子要素のうち、低屈折率高分散の方の前記回折光学素子(図6ではレンズL24が該当)の光学材料のd線,F線,C線に対する屈折率をそれぞれnd1,nF1,nC1とし、高屈折率低分散の方の前記回折光学素子(図6ではレンズL25が該当)の光学材料のd線,F線,C線に対する屈折率をそれぞれnd2,nF2,nC2とし、回折光学素子LDの回折光学面の有効径をφLDとし、対物レンズ系Lobの左右片側の最大射出瞳径をφAPとしたとき、以下の条件式(8)〜(12)を満足することが好ましい。 In the objective lens system L ob according to the present embodiment, as shown in FIG. 6, the second lens group G2 joins two diffractive element elements made of different optical materials, and a diffraction grating groove is formed on the joint surface. Among the two diffractive element elements made of different optical materials, the diffractive optical element having a low refractive index and high dispersion (shown in FIG. 6) has a multi-layered diffractive optical element LD having the formed diffractive optical surface D. Refractive indices of the optical material of the lens L24 with respect to the d-line, F-line, and C-line are nd1, nF1, and nC1, respectively, and the diffractive optical element having the higher refractive index and lower dispersion (corresponding to the lens L25 in FIG. 6). The refractive indices of the optical material for d-line, F-line, and C-line are nd2, nF2, and nC2, respectively, the effective diameter of the diffractive optical surface of the diffractive optical element LD is φLD, and the maximum emission on the left and right sides of the objective lens system L ob When the pupil diameter is φAP, It is preferable that the following conditional expressions (8) to (12) are satisfied.
nd1 ≦ 1.54 …(8)
0.0145 ≦ nF1−nC1 …(9)
1.55 ≦ nd2 …(10)
nF2−nC2 ≦ 0.013 …(11)
2.2 ≦ φLD/φAP …(12)
nd1 ≦ 1.54 (8)
0.0145 ≦ nF1-nC1 (9)
1.55 ≦ nd2 (10)
nF2-nC2 ≦ 0.013 (11)
2.2 ≦ φLD / φAP (12)
本実施形態に係る対物レンズ系Lobにおいて、第2レンズ群G2は、特に色収差を補正するために、回折光学素子LDを設けることが好ましい。回折光学素子LDは、1mmあたり数本から数百本の細かい溝状又はスリット状の格子構造が同心円状に形成された回折光学面Dを備え、この回折光学面Dに入射した光を格子ピッチ(回折格子溝の間隔)と入射光の波長によって定まる方向へ回折する性質を有している。また、回折光学素子LD(回折光学面D)は、負の分散値(本願の実施例ではアッベ数=-3.45)を有し、分散が大きく、また異常分散性(本願の実施例では部分分散比(ng-nF)/(nF-nC)=0.296)が強いため、強力な色収差補正能力を有している。光学ガラスのアッベ数は、通常30〜80程度であるが、回折光学素子のアッベ数は負の値を持っている。言い換えると、回折光学素子GDの回折光学面Dは、分散特性が通常のガラス(屈折光学素子)とは逆で、光の波長が短くなるに伴い屈折率が小さくなり、長い波長の光ほど大きく曲がる性質を有している。そのため、通常の屈折光学素子と組み合わせることにより、大きな色消し効果が得られる。したがって、回折光学素子LDを利用することで、色収差を良好に補正することが可能になる。 In the objective lens system L ob according to the present embodiment, it is preferable that the second lens group G2 is provided with a diffractive optical element LD, particularly for correcting chromatic aberration. The diffractive optical element LD includes a diffractive optical surface D in which several to hundreds of fine groove-shaped or slit-shaped grating structures are formed concentrically per 1 mm, and light incident on the diffractive optical surface D is grating pitch. It has the property of diffracting in a direction determined by the (grating groove interval) and the wavelength of incident light. The diffractive optical element LD (diffractive optical surface D) has a negative dispersion value (Abbe number = −3.45 in the embodiment of the present application), large dispersion, and anomalous dispersion (partial dispersion in the embodiment of the present application). Since the ratio (ng-nF) / (nF-nC) = 0.296) is strong, it has a strong ability to correct chromatic aberration. The Abbe number of the optical glass is usually about 30 to 80, but the Abbe number of the diffractive optical element has a negative value. In other words, the diffractive optical surface D of the diffractive optical element GD has a dispersion characteristic that is opposite to that of normal glass (refractive optical element), and the refractive index decreases as the wavelength of light decreases. It has the property of bending. Therefore, a large achromatic effect can be obtained by combining with an ordinary refractive optical element. Therefore, chromatic aberration can be favorably corrected by using the diffractive optical element LD.
本実施形態における回折光学素子LDは、異なる光学材料からなる二つの回折素子要素(例えば、図6の場合、光学部材L24,L25)を接合し、その接合面に回折格子溝を設けて回折光学面Dを構成している、いわゆる「密着複層型回折光学素子」である。そのため、この回折光学素子は、g線からC線を含む広波長域において回折効率を高くすることができる。したがって、本実施形態に係る対物レンズ系Lobは広波長域において利用することが可能となる。なお、回折効率は、透過型の回折光学素子において1次回折光を利用する場合、入射強度I0と一次回折光の強度I1との割合η(=I1/I0×100[%])を示す。 The diffractive optical element LD in the present embodiment joins two diffractive element elements (for example, optical members L24 and L25 in the case of FIG. 6) made of different optical materials, and provides a diffraction grating groove on the joint surface to provide diffractive optics. This is a so-called “contact multilayer diffractive optical element” constituting the surface D. Therefore, this diffractive optical element can increase the diffraction efficiency in a wide wavelength region including g-line to C-line. Therefore, the objective lens system L ob according to the present embodiment can be used in a wide wavelength region. The diffraction efficiency indicates the ratio η (= I1 / I0 × 100 [%]) between the incident intensity I0 and the intensity I1 of the first-order diffracted light when the first-order diffracted light is used in the transmission type diffractive optical element.
また、密着複層型回折光学素子LDは、回折格子溝が形成された二つの回折素子要素をこの回折格子溝同士が対向するように近接配置してなるいわゆる分離複層型回折光学素子に比べて製造工程を簡素化することができるため、量産効率がよく、また光線の入射角に対する回折効率が良いという長所を備えている。したがって、このような密着複層型回折光学素子LDを利用した本実施形態に係る顕微鏡対物レンズLobでは、製造が容易となり、また回折効率も良くなる。 In addition, the contact multilayer diffractive optical element LD is compared to a so-called separated multilayer diffractive optical element in which two diffraction element elements formed with diffraction grating grooves are arranged close to each other so that the diffraction grating grooves face each other. Thus, the manufacturing process can be simplified, so that the mass production efficiency is good and the diffraction efficiency with respect to the incident angle of the light beam is good. Therefore, the microscope objective lens L ob according to the present embodiment using such a contact multilayer diffractive optical element LD is easy to manufacture and also improves the diffraction efficiency.
ここで、条件式(8)〜(11)は、上記の回折光学素子LDを構成する異なる二つの回折素子要素の材料の屈折率と、F線及びC線に対する屈折率差(nF−nC)をそれぞれ規定している。これら条件式(8)〜(11)を満足することで、より良い性能で異なる二つの回折素子要素を密着接合させて回折光学面Dを形成することができる。その結果、g線〜C線までの広波長域に亘って90%以上の回折効率を実現することができる。しかしながら、条件式(8)〜(11)の上限値を上回るか又は下限値を下回ると、広波長域において90%以上の回折効率を得ることが困難になり、密着複層型回折光学素子LDの利点を維持することが困難になってしまう。 Here, the conditional expressions (8) to (11) indicate that the refractive index of the material of the two different diffractive element elements constituting the diffractive optical element LD and the difference in refractive index with respect to the F-line and C-line (nF−nC). Respectively. By satisfying these conditional expressions (8) to (11), it is possible to form the diffractive optical surface D by closely bonding two different diffractive element elements with better performance. As a result, a diffraction efficiency of 90% or more can be realized over a wide wavelength range from g-line to C-line. However, if the upper limit value of conditional expressions (8) to (11) is exceeded or falls below the lower limit value, it becomes difficult to obtain a diffraction efficiency of 90% or more in a wide wavelength region, and the contact multilayer diffractive optical element LD. It will be difficult to maintain the benefits.
また、上記条件式(12)は、密着複層型回折光学素子LDを形成する回折光学面Dの直径の適切な大きさを規定している。この条件式(12)の下限値を下回ると、回折光学面Dによる十分な色消し効果が得られなくなり、アポクロマート級の性能を達成することが困難となる。 The conditional expression (12) defines an appropriate size of the diameter of the diffractive optical surface D that forms the contact multilayer diffractive optical element LD. If the lower limit value of the conditional expression (12) is not reached, a sufficient achromatic effect by the diffractive optical surface D cannot be obtained, and it becomes difficult to achieve apochromat class performance.
なお、本実施形態の効果を確実なものとするために、条件式(12)の下限値を2.4以上とすることが好ましい。 In order to secure the effect of the present embodiment, it is preferable to set the lower limit of conditional expression (12) to 2.4 or more.
本実施形態においては、回折光学素子LDを、図6に示すような第2レンズ群G2を構成する平面に設けるのではなく、曲面に設けることも可能である。 In the present embodiment, the diffractive optical element LD can be provided on a curved surface instead of being provided on the plane constituting the second lens group G2 as shown in FIG.
さらに、本実施形態においては、第2レンズ群G2の焦点距離をf2とし、対物レンズ系Lobの全系の焦点距離をfとしたとき、以下の条件式(13)を満足することが好ましい。 Furthermore, in the present embodiment, it is preferable that the following conditional expression (13) is satisfied, where f2 is the focal length of the second lens group G2 and f is the focal length of the entire objective lens system Lob. .
6.00 < |f2/f| …(13) 6.00 <| f2 / f | (13)
上記条件式(13)は、第2レンズ群G2の焦点距離の適切な範囲を規定している。条件式(13)の下限値を下回ると、第2レンズ群G2の屈折力が強くなりすぎて、球面収差や軸上色収差の良好な補正が困難となる。 Conditional expression (13) defines an appropriate range of the focal length of the second lens group G2. If the lower limit of conditional expression (13) is not reached, the refractive power of the second lens group G2 becomes too strong, making it difficult to satisfactorily correct spherical aberration and longitudinal chromatic aberration.
なお、本実施形態の効果を確実なものとするために、条件式(13)の下限値を8.00とすることが好ましい。 In order to secure the effect of the present embodiment, it is preferable to set the lower limit value of conditional expression (13) to 8.00.
以下、本実施形態に係る各実施例について、図面に基づいて説明する。以下に、表1〜表3を示すが、これらは第1実施例〜第3実施例における各諸元の表である。 Hereinafter, each example according to the present embodiment will be described with reference to the drawings. Tables 1 to 3 are shown below, but these are tables of specifications in the first to third examples.
なお、表中において、面番号は物体Obから遠い側から数えたレンズ面の順序を、rは各レンズ面の曲率半径を、dは各光学面から次の光学面(又は物体Ob)までの光軸上の距離である面間隔を、ndはd線(波長587.6nm)に対する屈折率を、νdはd線に対するアッベ数を示す。なお、曲率半径の「∞」は平面を示す。また、空気の屈折率1.00000は省略する。 In the table, the surface number is the order of the lens surfaces counted from the side far from the object Ob, r is the radius of curvature of each lens surface, and d is the distance from each optical surface to the next optical surface (or object Ob). The interplanar spacing, which is the distance on the optical axis, nd is the refractive index for the d-line (wavelength 587.6 nm), and νd is the Abbe number for the d-line. The curvature radius “∞” indicates a plane. Also, the refractive index of air of 1.0000 is omitted.
また、以下の実施例において、密着複層型回折光学素子LDに形成された回折光学面Dの位相差は、通常の屈折率と後述する非球面式(a)とを用いて行う超高屈折率法により計算した。超高屈折率法とは、非球面形状と回折光学面の格子ピッチとの間の一定の等価関係を利用するものであり、本実施例においては、回折光学面Dを超高屈折率法のデータとして、すなわち後述する非球面式(a)及びその係数により示している。なお、本実施例では収差特性の算出対象として、d線、C線、F線及びg線を選んでいる。本実施例において用いられたこれらd線、C線、F線及びg線の波長と、各スペクトル線に対して設定した超高屈折率法の計算に用いるための屈折率の値を次の表4に示す。 In the following examples, the phase difference of the diffractive optical surface D formed on the contact multilayer diffractive optical element LD is an ultrahigh refraction performed using a normal refractive index and an aspherical formula (a) described later. Calculated by the rate method. The ultrahigh refractive index method uses a certain equivalent relationship between the aspherical shape and the grating pitch of the diffractive optical surface. In this embodiment, the diffractive optical surface D is replaced by the ultrahigh refractive index method. As data, that is, an aspherical expression (a) described later and its coefficient. In this embodiment, d-line, C-line, F-line and g-line are selected as the calculation target of the aberration characteristics. The wavelengths of these d-line, C-line, F-line and g-line used in this example and the refractive index values used for calculation of the ultrahigh refractive index method set for each spectral line are shown in the following table. 4 shows.
(表4)
波長 屈折率(超高屈折率法による)
d線 587.562nm 10001.0000
C線 656.273nm 11170.4255
F線 486.133nm 8274.7311
g線 435.835nm 7418.6853
(Table 4)
Wavelength Refractive index (by ultra-high refractive index method)
d-line 587.562nm 10001.0000
C line 656.273nm 11170.4255
F line 486.133nm 8274.7311
g-line 435.835nm 7418.6853
各実施例において、非球面は、光軸に垂直な方向の高さをyとし、高さyにおける各非球面の頂点の接平面から各非球面までの光軸に沿った距離(サグ量)をS(y)とし、基準球面の曲率半径(頂点曲率半径)をrとし、円錐定数をκとし、n次の非球面係数をAnとしたとき、以下の式(a)で表される。なお、以降の実施例において、「E-n」は「×10-n」を示す。 In each embodiment, the height of the aspheric surface in the direction perpendicular to the optical axis is y, and the distance (sag amount) along the optical axis from the tangential plane of the apex of each aspheric surface to each aspheric surface at height y. Is S (y), r is the radius of curvature of the reference sphere (vertex radius of curvature), κ is the conic constant, and An is the nth-order aspherical coefficient. In the following examples, “E-n” represents “× 10 −n ”.
S(y)=(y2/r)/{1+(1−κ×y2/r2)1/2}
+A2×y2+A4×y4+A6×y6+A8×y8 …(a)
S (y) = (y 2 / r) / {1+ (1−κ × y 2 / r 2 ) 1/2 }
+ A2 × y 2 + A4 × y 4 + A6 × y 6 + A8 × y 8 (a)
なお、各実施例において、回折光学面が形成されたレンズ面には、表中の面番号の右側に*印を付しており、非球面式(a)は、この回折光学面の性能の諸元を示している。 In each example, the lens surface on which the diffractive optical surface is formed is marked with an asterisk (*) on the right side of the surface number in the table. The aspherical expression (a) indicates the performance of the diffractive optical surface. The specifications are shown.
また、表中において、fは対物レンズ系Lobの全系の焦点距離を、WDは作動距離を、fB1は第1レンズ群G1を構成する負の屈折力を持つ接合レンズの焦点距離を、f1は第1レンズ群G1の焦点距離を、f2は第2レンズ群G2の焦点距離を、f3は第3レンズ群G3の焦点距離をf3を、νdL1は第1レンズ群G1を構成する正の屈折力を持つ単レンズのアッベ数を、SBHは対物レンズ系と組み合わせて使用する左右の観察光学系LR,LLの(より詳しくは変倍光学系LZR,LZLによる)ズーム最高倍での対物側軸間距離を、SBLは対物レンズ系と組み合わせて使用する左右の観察光学系LR,LLの(変倍光学系LZR,LZLによる)ズーム最低倍での対物側軸間距離を、φAPは対物レンズ系Lobの左右片側の最大射出瞳径を、Ymaxは対物レンズ系Lobの観察可能な最大物体高をそれぞれ示す。さらに、表中には、上記条件式(1)〜(13)に対応する値も示す。 In the tables, f is the focal length of the entire system of the objective lens system L ob, WD to the working distance, fB1 the focal length of the cemented lens having a negative refractive power constituting the first lens group G1, f1 is a focal length of the first lens group G1, f2 is a focal length of the second lens group G2, f3 is a focal length of the third lens group G3, and νdL1 is a positive constituting the first lens group G1. SBH is the maximum magnification of the left and right observation optical systems L R and L L used in combination with the objective lens system (more specifically, by the variable magnification optical systems L ZR and L ZL ). The SBL is the distance between the objective side axes at the minimum zoom of the left and right observation optical systems L R and L L (using the variable magnification optical systems L ZR and L ZL ) used in combination with the objective lens system. ΦAP is the maximum exit pupil diameter on the left and right sides of the objective lens system L ob The, Ymax denotes the maximum object height observable objective lens system L ob respectively. Further, the table also shows values corresponding to the conditional expressions (1) to (13).
以下、全ての諸元値において掲載される焦点距離f、曲率半径r、面間隔d、その他の長さ等は、特記の無い場合一般に「mm」が使われるが、光学系は比例拡大又は比例縮小しても同等の光学性能が得られるので、これに限られるものではない。また、単位は「mm」に限定されることなく、他の適当な単位を用いることが可能である。 Hereinafter, “mm” is generally used for the focal length f, the radius of curvature r, the surface interval d, and other lengths, etc. unless otherwise specified, but the optical system is proportionally enlarged or proportional. Since the same optical performance can be obtained even if the image is reduced, the present invention is not limited to this. Further, the unit is not limited to “mm”, and other appropriate units can be used.
ここまでの表の説明は全ての実施例において共通であり、以下での説明を省略する。 The description of the table so far is common to all the embodiments, and the description below is omitted.
(第1実施例)
第1実施例に係る平行系実体顕微鏡用対物レンズ系Lob(Lob1)について、図2、図3及び表1を用いて説明する。第1実施例に係る平行系実体顕微鏡用対物レンズ系Lob1は、図2に示すように、物体Obから遠い側より順に並んだ、全体として正の屈折力を持つ第1レンズ群G1と、相対的に屈折力の弱い第2レンズ群G2と、全体として正の屈折力を持つ第3レンズ群G3とを有する。
(First embodiment)
The objective lens system L ob (L ob1 ) for the parallel stereomicroscope according to the first example will be described with reference to FIGS. 2 and 3 and Table 1. FIG. As shown in FIG. 2, the objective lens system L ob1 for the parallel stereomicroscope according to the first example is arranged in order from the side far from the object Ob, and has a first lens group G1 having a positive refractive power as a whole, It has a second lens group G2 having a relatively weak refractive power and a third lens group G3 having a positive refractive power as a whole.
第1レンズ群G1は、物体Obから遠い側より順に並んだ、両凸レンズL11と、物体側に凹面を向けた負メニスカスレンズL12と両凸レンズL13とからなり、全体として負の屈折力を持つ接合レンズとを有する。 The first lens group G1 includes a biconvex lens L11, a negative meniscus lens L12 having a concave surface facing the object side, and a biconvex lens L13, which are arranged in order from the side far from the object Ob, and has a negative refractive power as a whole. And a lens.
第2レンズ群G2は、物体Obから遠い側より順に並んだ、物体側に凸面を向けた負メニスカスレンズL21と物体側に凸面を向けた正メニスカスレンズL22とを貼り合わせ、全体として物体側に凸面を向けたメニスカス形状の負の屈折力を持つ接合レンズと、両凸レンズL23と両凹レンズL24と両凸レンズL25の3枚を貼り合わせ、全体として正の屈折力を持つ接合レンズとを有する。 The second lens group G2 is composed of a negative meniscus lens L21 having a convex surface facing the object side and a positive meniscus lens L22 having a convex surface facing the object side, which are arranged in order from the side farther from the object Ob. A cemented lens having a negative meniscus refractive power with a convex surface and a biconvex lens L23, a biconcave lens L24, and a biconvex lens L25 are bonded together to form a cemented lens having a positive refractive power as a whole.
第3レンズ群G3は、物体Obから遠い側より順に並んだ、両凸レンズL31と、両凸レンズL32とを有する。 The third lens group G3 includes a biconvex lens L31 and a biconvex lens L32 arranged in this order from the side farther from the object Ob.
表1に第1実施例における各諸元の値を掲げる。なお、表1の面番号1〜16は、図2に示す面1〜16に対応している。 Table 1 lists the values of each item in the first embodiment. In addition, the surface numbers 1-16 of Table 1 respond | correspond to the surfaces 1-16 shown in FIG.
なお、観察光学系LR,LLの対物側光軸間距離はSB=26mm(固定)、対物レンズ系Lob1の最大有効径はDmax=80mmである。また、観察光学系LR,LLの入射瞳位置は、対物レンズ系Lob1の第1面からズーム最低倍時43mm、ズーム最高倍時242mm、物体面Obから遠ざかる位置にある。 The distance between the objective optical axes of the observation optical systems L R and L L is SB = 26 mm (fixed), and the maximum effective diameter of the objective lens system L ob1 is Dmax = 80 mm. In addition, the entrance pupil positions of the observation optical systems L R and L L are at a position 43 mm from the first surface of the objective lens system L ob1 at a zoom minimum of 43 mm, a zoom maximum magnification of 242 mm, and a position away from the object plane Ob.
(表1)
f = 50.2
WD = 31.0
fB1 = -288.0
f1 = 147.9
f2 = 652.7
f3 = 61.5
面番号 r d nd
νd
1 116.46700 7.500 1.84666 23.9
2 -284.85506 0.500
3 142.07687 3.000 1.83481 42.7
4 35.04100 14.481 1.43425 95.0
5 -230.00729 9.576
6 -34.05100 3.745 1.74950 35.3
7 -139.48185 15.336 1.43425 95.0
8 -40.09000 0.500
9 154.98239 14.731 1.59240 68.3
10 -125.00000 4.000 1.90265 35.7
11 126.14143 20.000 1.59240 68.3
12 -90.02700 0.500
13 179.34654 13.031 1.59240 68.3
14 -178.07559 0.500
15 56.52200 16.000 1.59240 68.3
16 1102.18933
[条件式]
条件式(1) (−fB1)/f = 5.74
条件式(2) f1/f = 2.95
条件式(3) f3/f = 1.22
条件式(4) νdL1 = 23.9
条件式(13) |f2/f| = 13.00
(Table 1)
f = 50.2
WD = 31.0
fB1 = -288.0
f1 = 147.9
f2 = 652.7
f3 = 61.5
Surface number r d nd
νd
1 116.46700 7.500 1.84666 23.9
2 -284.85506 0.500
3 142.07687 3.000 1.83481 42.7
4 35.04100 14.481 1.43425 95.0
5 -230.00729 9.576
6 -34.05100 3.745 1.74950 35.3
7 -139.48185 15.336 1.43425 95.0
8 -40.09000 0.500
9 154.98239 14.731 1.59240 68.3
10 -125.00000 4.000 1.90265 35.7
11 126.14143 20.000 1.59240 68.3
12 -90.02700 0.500
13 179.34654 13.031 1.59240 68.3
14 -178.07559 0.500
15 56.52200 16.000 1.59240 68.3
16 1102.18933
[Conditional expression]
Conditional expression (1) (-fB1) / f = 5.74
Conditional expression (2) f1 / f = 2.95
Conditional expression (3) f3 / f = 1.22
Conditional expression (4) νdL1 = 23.9
Conditional expression (13) | f2 / f | = 13.00
なお、表1に示した条件式の値のうち、条件式(4)は第1面の値に相当する。このように表1に示す諸元の表から、本実施例に係る平行系実体顕微鏡用対物レンズ系Lob1では、上記条件式(1)〜(4)及び(13)を満たすことが分かる。 Of the values of the conditional expressions shown in Table 1, conditional expression (4) corresponds to the value of the first surface. Thus, it can be seen from the table of specifications shown in Table 1 that the conditional expressions (1) to (4) and (13) are satisfied in the objective lens system Lob1 for the parallel stereomicroscope according to the present embodiment.
図3は、第1実施例に係る平行系実体顕微鏡用対物レンズ系における、横収差図、非点収差図及び歪曲収差図である。各収差図はいずれも、物体Obより遠い側(観察光学系LR,LL側)より光線を入射させて追跡したもので、観察光学系LR,LLの光軸を通る光線を基準にして表示してある。このような各収差図において、yは像高を、非点収差図においてSはサジタル面を、Mはメリジオナル面をそれぞれ示す。また、横収差図はズーム高倍時のものを、非点収差図及び歪曲収差図はズーム低倍時のものを示す。なお、以下全ての実施例の諸収差図は、本実施例の収差図と同様の符号を用いる。 FIG. 3 is a lateral aberration diagram, an astigmatism diagram, and a distortion diagram in the objective lens system for the parallel stereomicroscope according to the first example. Each of the aberration diagrams is tracked by entering light rays from the side farther from the object Ob (observation optical systems L R and L L side), and the light rays passing through the optical axes of the observation optical systems L R and L L are used as a reference. Is displayed. In each of these aberration diagrams, y represents an image height, S in the astigmatism diagram represents a sagittal surface, and M represents a meridional surface. Further, the lateral aberration diagram shows the zoom at high magnification, and the astigmatism diagram and the distortion diagram show the zoom at low magnification. In addition, the same symbols as those in this embodiment are used in the various aberration diagrams in all the following examples.
図3に示す収差図から明らかであるように、第1実施例に係る平行系実体顕微鏡用対物レンズ系Lob1では、良好に収差補正されていることが分かる。 As is apparent from the aberration diagram shown in FIG. 3, it can be seen that the objective lens system L ob1 for the parallel system stereomicroscope according to the first example is well corrected for aberrations.
(第2実施例)
第2実施例に係る平行系実体顕微鏡用対物レンズ系Lob(Lob2)について、図4、図5及び表2を用いて説明する。第2実施例に係る平行系実体顕微鏡用対物レンズ系Lob2は、図4に示すように、物体Obから遠い側より順に並んだ、全体として正の屈折力を持つ第1レンズ群G1と、相対的に屈折力の弱い第2レンズ群G2と、全体として正の屈折力を持つ第3レンズ群G3とを有する。
(Second embodiment)
The objective lens system L ob (L ob2 ) for the parallel stereomicroscope according to the second example will be described with reference to FIGS. 4 and 5 and Table 2. FIG. As shown in FIG. 4, the objective lens system L ob2 for the parallel stereomicroscope according to the second example is arranged in order from the side far from the object Ob, and has a first lens group G1 having a positive refractive power as a whole, It has a second lens group G2 having a relatively weak refractive power and a third lens group G3 having a positive refractive power as a whole.
第1レンズ群G1は、物体Obから遠い側より順に並んだ、両凸レンズL11と、物体側に凹面を向けた負メニスカスレンズL12と両凸レンズL13とからなり、全体として負の屈折力を持つ接合レンズとを有する。 The first lens group G1 includes a biconvex lens L11, a negative meniscus lens L12 having a concave surface facing the object side, and a biconvex lens L13, which are arranged in order from the side far from the object Ob, and has a negative refractive power as a whole. And a lens.
第2レンズ群G2は、物体Obから遠い側より順に並んだ、物体側に平面を向けた平凹レンズL21と物体側に凸面を向けた平凸レンズL22とを貼り合わせ、全体として物体側に凸面を向けたメニスカス形状の負の屈折力を持つ接合レンズと、両凸レンズL23と両凹レンズL24と両凸レンズL25の3枚を貼り合わせ、全体として正の屈折力を持つ接合レンズとを有する。 The second lens group G2 is composed of a plano-concave lens L21 having a plane facing the object side and a plano-convex lens L22 having a convex surface facing the object side, which are arranged in order from the side far from the object Ob, and has a convex surface on the object side as a whole. A meniscus-shaped cemented lens having negative refractive power and a biconvex lens L23, a biconcave lens L24, and a biconvex lens L25 are bonded together to form a cemented lens having a positive refractive power as a whole.
第3レンズ群G3は、物体Obから遠い側より順に並んだ、両凸レンズL31と、物体側に平面を向けた平凸レンズL32とを有する。 The third lens group G3 includes a biconvex lens L31 and a planoconvex lens L32 which are arranged in order from the side farther from the object Ob and the plane is directed to the object side.
表2に第2実施例における各諸元の値を掲げる。なお、表2の面番号1〜16は、図4に示す面1〜16に対応している。
Table 2 lists the values of each item in the second embodiment. The
なお、観察光学系LR,LLの対物側光軸間距離はズーム最低倍時SBL=20mm、ズーム最高倍時SBH=26mm、対物レンズ系Lob2の最大有効径はDmax=71mmである。また、観察光学系LR,LLの入射瞳位置は、対物レンズ系Lob2の第1面からズーム最低倍時43mm、ズーム最高倍時242mm、物体面Obから遠ざかる位置にある。 Note that the distance between the objective-side optical axes of the observation optical systems L R and L L is SBL = 20 mm at the zoom minimum magnification, SBH = 26 mm at the zoom maximum magnification, and the maximum effective diameter of the objective lens system L ob2 is Dmax = 71 mm. Further, the entrance pupil positions of the observation optical systems L R and L L are at a position 43 mm from the first surface of the objective lens system L ob2 at a zoom minimum of 43 mm, a zoom maximum magnification of 242 mm, and a position away from the object plane Ob.
(表2)
f = 50.2
WD = 31.5
fB1 = -394.0
f1 = 129.6
f2 = 435.2
f3 = 63.4
SBL = 20
SBH = 26
Ymax = 11
面番号 r d nd
νd
1 102.33094 7.500 1.84666 23.9
2 -421.35943 0.500
3 114.20080 3.000 1.83481 42.7
4 32.98856 15.000 1.43425 95.0
5 -209.56031 8.600
6 -35.99216 8.000 1.74950 35.3
7 ∞ 17.000 1.49782 82.5
8 -44.47866 0.500
9 134.37622 14.000 1.59319 67.9
10 -125.00000 3.500 1.83400 37.2
11 125.00000 16.000 1.59240 68.3
12 -110.11690 0.900
13 185.36898 10.500 1.59319 67.9
14 -194.94628 0.500
15 60.31541 13.000 1.59319 67.9
16 ∞
[条件式]
条件式(1) (−fB1)/f = 7.85
条件式(2) f1/f = 2.58
条件式(3) f3/f = 1.26
条件式(4) νdL1 = 23.9
条件式(5) SBH−SBL = 6
条件式(6) φAP = 25
条件式(7) Ymax/f = 0.219
条件式(13) |f2/f| = 8.70
(Table 2)
f = 50.2
WD = 31.5
fB1 = -394.0
f1 = 129.6
f2 = 435.2
f3 = 63.4
SBL = 20
SBH = 26
Ymax = 11
Surface number r d nd
νd
1 102.33094 7.500 1.84666 23.9
2 -421.35943 0.500
3 114.20080 3.000 1.83481 42.7
4 32.98856 15.000 1.43425 95.0
5 -209.56031 8.600
6 -35.99216 8.000 1.74950 35.3
7 ∞ 17.000 1.49782 82.5
8 -44.47866 0.500
9 134.37622 14.000 1.59319 67.9
10 -125.00000 3.500 1.83400 37.2
11 125.00000 16.000 1.59240 68.3
12 -110.11690 0.900
13 185.36898 10.500 1.59319 67.9
14 -194.94628 0.500
15 60.31541 13.000 1.59319 67.9
16 ∞
[Conditional expression]
Conditional expression (1) (−fB1) /f=7.85
Conditional expression (2) f1 / f = 2.58
Conditional expression (3) f3 / f = 1.26
Conditional expression (4) νdL1 = 23.9
Conditional expression (5) SBH-SBL = 6
Conditional expression (6) φAP = 25
Conditional expression (7) Ymax / f = 0.219
Conditional expression (13) | f2 / f | = 8.70
なお、表2に示した条件式の値のうち、条件式(4)は第1面の値に相当する。このような表2に示す諸元の表から、本実施例に係る平行系実体顕微鏡用対物レンズ系Lob2では、上記条件式(1)〜(7)及び(13)を満たすことが分かる。 Of the values of the conditional expressions shown in Table 2, conditional expression (4) corresponds to the value of the first surface. From the table of specifications shown in Table 2, it can be seen that the objective lens system L ob2 for the parallel stereomicroscope according to the present example satisfies the conditional expressions (1) to (7) and (13).
図5は、第2実施例に係る平行系実体顕微鏡用対物レンズ系Lob2の横収差図、非点収差図及び歪曲収差図である。図5に示す収差図から明らかであるように、第2実施例に係る平行系実体顕微鏡用対物レンズ系Lob2では、良好に収差補正されていることが分かる。 FIG. 5 is a transverse aberration diagram, astigmatism diagram, and distortion diagram of the objective lens system Lob2 for the parallel stereomicroscope according to the second example. As is apparent from the aberration diagram shown in FIG. 5, it can be seen that the objective lens system Lob2 for the parallel system stereomicroscope according to the second example is well corrected for aberrations.
(第3実施例)
第3実施例に係る平行系実体顕微鏡用対物レンズ系Lob(Lob3)について、図6、図7及び表3を用いて説明する。第3実施例に係る平行系実体顕微鏡用対物レンズ系Lob3は、図6に示すように、物体Obから遠い側より順に並んだ、全体として正の屈折力を持つ第1レンズ群G1と、相対的に屈折力の弱い第2レンズ群G2と、全体として正の屈折力を持つ第3レンズ群G3とを有する。
(Third embodiment)
The objective lens system L ob (L ob3 ) for the parallel stereomicroscope according to the third example will be described with reference to FIGS. 6 and 7 and Table 3. FIG. As shown in FIG. 6, the objective lens system L ob3 for the parallel stereomicroscope according to the third example is arranged in order from the side far from the object Ob, and has a first lens group G1 having a positive refractive power as a whole, It has a second lens group G2 having a relatively weak refractive power and a third lens group G3 having a positive refractive power as a whole.
第1レンズ群G1は、物体Obから遠い側より順に並んだ、物体側に凸面を向けた正メニスカスレンズL11と、両凸レンズL12と両凹レンズL13とからなり、全体として負の屈折力を持つ接合レンズとを有する。 The first lens group G1 is composed of a positive meniscus lens L11 having a convex surface facing the object side, a biconvex lens L12, and a biconcave lens L13 arranged in order from the side far from the object Ob, and has a negative refractive power as a whole. And a lens.
第2レンズ群G2は、物体Obから遠い側より順に並んだ、物体側に凸面を向けた負メニスカスレンズL21と、物体側に凸面を向けた正メニスカスレンズL22と回折光学面Dを含む回折光学素子LDと物体側に凹面を向けた平凹レンズL26と両凸レンズL27を貼り合わせ、全体として正屈折力を持つ接合レンズとを有する。 The second lens group G2 includes a negative meniscus lens L21 having a convex surface facing the object side, a positive meniscus lens L22 having a convex surface facing the object side, and a diffractive optical surface D, which are arranged in order from the side far from the object Ob. An element LD, a plano-concave lens L26 having a concave surface directed toward the object side, and a biconvex lens L27 are bonded together to have a cemented lens having positive refractive power as a whole.
なお、回折光学素子LDは、平板状の光学ガラスL23と、それぞれ異なる樹脂材料から形成された平板状の二つの光学部材L24,L25とがこの順で接合され、光学部材L24,L25の接合面に回折格子溝(回折光学面D)が形成されている。すなわち、この回折光学素子LDは、密着複層型の回折光学素子である。なお、本実施例では、二つの光学部材L24,L25の接合面が平面となっているが、回折光学面Dが曲率を持った接合面として形成されていても同等の効果が得られることは言うまでもない。 In the diffractive optical element LD, a flat optical glass L23 and two flat optical members L24 and L25 formed from different resin materials are bonded in this order, and the bonding surfaces of the optical members L24 and L25 are joined. A diffraction grating groove (diffractive optical surface D) is formed on the surface. That is, the diffractive optical element LD is a contact multilayer diffractive optical element. In the present embodiment, the joint surfaces of the two optical members L24 and L25 are flat, but the same effect can be obtained even if the diffractive optical surface D is formed as a joint surface having a curvature. Needless to say.
第3レンズ群G3は、物体Obから遠い側より順に並んだ、両凸レンズL31と、物体側に凹面を向けた正メニスカスレンズL32とを有する。 The third lens group G3 includes a biconvex lens L31 and a positive meniscus lens L32 having a concave surface directed toward the object side, arranged in order from the side far from the object Ob.
表3に第3実施例における各諸元の値を掲げる。なお、表3の面番号1〜20は、図6に示す面1〜20に対応している。
Table 3 lists the values of each item in the third embodiment. The
なお、観察光学系LR,LLの対物側光軸間距離はズーム最低倍時SBL=20mm、ズーム最高倍時SBH=26mm、対物レンズ系Lob3の最大有効径はDmax=68.45mmである。また、観察光学系LR,LLの入射瞳位置は、対物レンズ系Lob3の第1面からズーム最低倍時43mm、ズーム最高倍時242mm、物体面Obから遠ざかる位置にある。 The distance between the objective optical axes of the observation optical systems L R and L L is SBL = 20 mm at the zoom minimum magnification, SBH = 26 mm at the zoom maximum magnification, and the maximum effective diameter of the objective lens system L ob3 is Dmax = 68.45 mm. is there. Furthermore, the entrance pupil position of the observation optical system L R, L L is from the first surface of the objective lens system L ob3 zoom minimum times when 43 mm, the zoom up times when 242 mm, a position away from the object plane Ob.
(表3)
f = 50.2
WD = 31.0
fB1 = -420.9
f1 = 166.8
f2 = 756.1
f3 = 59.9
SBL = 20
SBH = 26
Ymax = 11
φLD = 64.23
[回折光学面データ]
第12面
κ=1.0000,A2=1.10205E-08,A4=-6.68539E-12,A6=3.87380E-15,A8=-1.40808E-18
[条件式]
条件式(1) (−fB1)/f = 8.38
条件式(2) f1/f = 3.32
条件式(3) f3/f = 1.19
条件式(4) νdL1 = 23.9
条件式(5) SBH−SBL = 6
条件式(6) φAP = 25
条件式(7) Ymax/f = 0.219
条件式(8) nd1 = 1.53
条件式(9) nF1−nC1 = 0.0152
条件式(10) nd2 = 1.56
条件式(11) nF2−nC2 = 0.0111
条件式(12) φLD/φAP = 2.57
条件式(13) |f2/f| = 15.06
(Table 3)
f = 50.2
WD = 31.0
fB1 = -420.9
f1 = 166.8
f2 = 756.1
f3 = 59.9
SBL = 20
SBH = 26
Ymax = 11
φLD = 64.23
[Diffraction optical surface data]
12th surface κ = 1.0000, A2 = 1.10205E-08, A4 = -6.68539E-12, A6 = 3.87380E-15, A8 = -1.40808E-18
[Conditional expression]
Conditional expression (1) (-fB1) / f = 8.38
Conditional expression (2) f1 / f = 3.32
Conditional expression (3) f3 / f = 1.19
Conditional expression (4) νdL1 = 23.9
Conditional expression (5) SBH-SBL = 6
Conditional expression (6) φAP = 25
Conditional expression (7) Ymax / f = 0.219
Conditional expression (8) nd1 = 1.53
Conditional expression (9) nF1-nC1 = 0.0152
Conditional expression (10) nd2 = 1.56
Conditional expression (11) nF2-nC2 = 0.0111
Conditional expression (12) φLD / φAP = 2.57
Conditional expression (13) | f2 / f | = 15.06
なお、表3に示した条件式の値のうち、条件式(4)は第1面の値に相当し、条件式(8),(9)は第11面の値に相当し、条件式(10),(11)は第13面の値に相当する。このように表3に示す諸元の表から、本実施例に係る平行系実体顕微鏡用対物レンズ系Lob3では、上記条件式(1)〜(13)を満たすことが分かる。 Of the values of the conditional expressions shown in Table 3, conditional expression (4) corresponds to the value of the first surface, and conditional expressions (8) and (9) correspond to the values of the eleventh surface. (10) and (11) correspond to the values of the thirteenth surface. Thus, it can be understood from the table of specifications shown in Table 3 that the conditional expressions (1) to (13) are satisfied in the objective lens system Lob3 for the parallel stereomicroscope according to the present embodiment.
図7は、第3実施例に係る平行系実体顕微鏡用対物レンズ系Lob3の横収差図、非点収差図及び歪曲収差図である。図7に示す収差図から明らかであるように、第3実施例に係る平行系実体顕微鏡用対物レンズ系Lob3では、良好に収差補正されていることが分かる。 FIG. 7 is a lateral aberration diagram, an astigmatism diagram, and a distortion diagram of the objective lens system Lob3 for the parallel stereomicroscope according to the third example. As is apparent from the aberration diagram shown in FIG. 7, it can be seen that the objective lens system Lob3 for the parallel system stereomicroscope according to the third example is well corrected for aberrations.
以上のような構成により、本発明に係る平行系実体顕微鏡用対物レンズ系によれば、歪曲収差を実用上問題の無い程度に抑え、像面の平坦性を確保するとともに、その他の諸収差も良好に補正することにより、優れた結像性能を実現することが可能である。その結果、この対物レンズ系に変倍光学系を組み合わせて使用した場合であっても、変倍に伴う視野領域や開口数が拡大してもコンパクトな対物レンズを構成することができ、良好な観察を実施することが可能となる。 With the configuration as described above, according to the objective lens system for a parallel stereomicroscope according to the present invention, distortion is suppressed to a practically unproblematic level, and the flatness of the image surface is ensured. By correcting well, it is possible to realize excellent imaging performance. As a result, even when a variable magnification optical system is used in combination with this objective lens system, a compact objective lens can be configured even if the field of view and numerical aperture accompanying magnification change are increased. Observation can be carried out.
なお、本発明を分かりやすくするために、実施形態の構成要件を付して説明したが、本発明がこれに限定されるものではないことは言うまでもない。 In addition, in order to make this invention intelligible, although demonstrated with the component requirement of embodiment, it cannot be overemphasized that this invention is not limited to this.
Lob(Lob1〜Lob3) 平行系実体顕微鏡用対物レンズ系
G1 第1レンズ群
G2 第2レンズ群
G3 第3レンズ群
L11〜L32 平行系実体顕微鏡用対物レンズ系の構成レンズ
B1 第1レンズ群を構成する負の屈折力を持つ接合レンズ
LD 密着複層型回折光学素子
D 回折光学面
L ob (L ob1 to L ob3 ) Objective lens system for parallel system microscope G1 First lens group G2 Second lens group G3 Third lens group L11 to L32 Constituent lens B1 first lens for parallel system microscope Bonded lens with negative refractive power that constitutes a group LD Adhesive multilayer diffractive optical element D Diffraction optical surface
Claims (6)
負の屈折力を持つ接合レンズを含み、全体として正の屈折力を持つ第1レンズ群と、
物体側に凸面を向けたメニスカス形状の負の屈折力を持つレンズと、正の屈折力を持つ接合レンズとを含む第2レンズ群と、
少なくとも1枚の正の屈折力を持つ単レンズを含み、全体として正の屈折力を持つ第3レンズ群とから構成される平行系実体顕微鏡用対物レンズ系であって、
前記第1レンズ群を構成する前記負の屈折力を持つ接合レンズの焦点距離をfB1とし、前記対物レンズ系全系の焦点距離をfとしたとき、次式
5.00 < (−fB1)/f < 20.00
の条件を満足し、
前記第2レンズ群の焦点距離をf2としたとき、次式
6.00 < |f2/f|
の条件も満足することを特徴とする平行系実体顕微鏡用対物レンズ系。 Arranged in order from the far side from the object,
A first lens group including a cemented lens having a negative refractive power and having a positive refractive power as a whole;
A second lens group including a meniscus lens having negative refractive power with a convex surface facing the object side, and a cemented lens having positive refractive power;
An objective lens system for a parallel system stereomicroscope including at least one single lens having a positive refractive power and composed of a third lens group having a positive refractive power as a whole,
When the focal length of the cemented lens having the negative refractive power constituting the first lens group is fB1, and the focal length of the entire objective lens system is f, the following formula 5.00 <(− fB1) / f <20.00
Satisfy the conditions of
When the focal length of the second lens group is f2, the following expression 6.00 <| f2 / f |
An objective lens system for a parallel stereomicroscope characterized by satisfying the above conditions.
この第1レンズ群を構成する前記正の屈折力を持つ単レンズのアッベ数をνdL1としたとき、次式
νdL1 <40.0
の条件を満足することを特徴とする請求項1に記載の平行系実体顕微鏡用対物レンズ系。 The first lens group includes a single lens having a positive refractive power,
When the Abbe number of the single lens having the positive refractive power constituting the first lens group is νdL1, the following equation νdL1 <40.0
The objective lens system for a parallel stereomicroscope according to claim 1, wherein the following condition is satisfied.
前記正の屈折力を持つ接合レンズは、両凸レンズと両凹レンズと両凸レンズの3枚を貼り合わせた接合レンズであることを特徴とする請求項1又は2に記載の平行系実体顕微鏡用対物レンズ系。 The meniscus lens having negative refractive power that forms the second lens group and has a convex surface facing the object side is a cemented meniscus lens in which a negative lens and a positive lens are bonded together,
3. The objective lens for a parallel system stereomicroscope according to claim 1, wherein the cemented lens having a positive refractive power is a cemented lens in which three lenses of a biconvex lens, a biconcave lens, and a biconvex lens are bonded together. system.
特徴とする請求項1〜3のいずれか一項に記載の平行系実体顕微鏡用対物レンズ系。 The second lens group includes a contact multilayer diffractive optical element having a diffractive optical surface in which two diffractive element elements made of different optical materials are bonded and a diffraction grating groove is formed on the bonded surface. The objective-lens system for parallel system stereomicroscopes as described in any one of Claims 1-3.
前記平行系実体顕微鏡用対物レンズ系の物体側と反対側の面に対向し、前記平行系実体顕微鏡用対物レンズ系の光軸を挟んで並列配置され、前記対物レンズ系により物体からの光を平行光束に変換された光を受光する左眼用と右眼用の二つの観察光学系とを備えて構成される平行系実体顕微鏡。 The parallel-system stereomicroscope objective lens system according to any one of claims 1 to 4,
Opposing the object side of the parallel-system stereomicroscope objective lens system on the opposite side of the object side, arranged in parallel across the optical axis of the parallel-system stereomicroscope objective lens system, the light from the object by the objective lens system A parallel stereomicroscope configured to include two observation optical systems for left eye and right eye that receive light converted into a parallel light beam.
1mm ≦ SBH−SBL ≦ 10mm
の条件を満足し、
前記観察光学系の最大入射瞳径をφAP(単位:mm)とし、前記対物レンズ系の観察可能な最大物体高をYmaxとしたとき、次式
23mm ≦ φAP ≦ 30mm
0.160 ≦ Ymax/f
の条件を満足することを特徴とする請求項5に記載の平行系実体顕微鏡。 The observation optical system includes a variable magnification optical system, the distance between the objective side axes at the maximum zoom magnification of the variable magnification optical system is SBH (unit: mm), and the objective at the minimum zoom magnification of the variable magnification optical system When the distance between the side axes is SBL (unit: mm) , the following formula: 1 mm ≦ SBH−SBL ≦ 10 mm
Satisfy the conditions of
When the maximum entrance pupil diameter of the observation optical system is φAP (unit: mm) and the maximum object height that can be observed by the objective lens system is Ymax, the following expression is given: 23 mm ≦ φAP ≦ 30 mm
0.160 ≤ Ymax / f
The parallel stereomicroscope according to claim 5, wherein the following condition is satisfied.
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Free format text: JAPANESE INTERMEDIATE CODE: R250 |
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R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
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R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |