JPH09318882A - Stereomicroscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a stereomicroscope where the change of a stereoscopic effect caused by variable power is little, whose constitution is simple and which is excellent in workability by arranging a light shielding member shielding light on the outside of the pupil of the center image of visual field on an object side from an image- formation point at the time of setting the highest magnification. SOLUTION: This microscope is equipped with an objective lens 1 common to right and left, the light shielding member 2, a variable power relay optical system 3 coaxial with the lens 1 and having the image-formation point I inside, and aperture diaphragms 4L and 4R for observing left and right. Left and right image-formation optical systems 5L and 5R coaxial with the aperture diaphragms 4L and 4R form an image so that the image can be stereoscopically observed with both eyes, and left and right oculars 6L and 6R enlarge the formed image. An observation optical axis decided by a pair of aperture diaphragms 4L and 4R passes place different from the optical axis of the optical system 3. Then, the light shielding member 2 shielding the light on the outside of the pupil of the center image of the visual field decided by a pair of aperture diaphragms 4L and 4R is arranged on the object side from the point I at the time of setting the highest magnification.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an objective lens, one variable-power optical system that includes at least one image-forming plane and is coaxial with the objective lens, and is disposed behind the variable-power optical system. Each has an aperture stop, a pair of left and right observation optical systems including an imaging lens and an eyepiece lens, and the observation optical axis determined by the aperture stop passes through a position different from the optical axis of the variable power optical system. About the stereo microscope becoming.

[0002]

2. Description of the Related Art Stereomicroscopes are used for assembling small objects and for various kinds of operations because they can obtain stereoscopic information by enlarging an object image. Then, in order to enable more difficult work, there is a demand for a stereomicroscope that allows a plurality of people to observe images at the same time and observe from any direction. In order to meet this demand, conventionally, a stereomicroscope has been proposed in which light beams that form the respective images seen by the left and right eyes pass through a single variable power system. By rotating the aperture stop for the left and right optical paths around the optical axis of the variable power system, the viewing direction can be freely changed.

[0003]

However, this optical system has a problem that the stereoscopic effect changes when the magnification is changed. A method for solving this problem is disclosed in Japanese Unexamined Patent Publication
-76514. In this method, an optical member for correcting the stereoscopic effect according to the magnification change is provided, and the stereoscopic effect is corrected by moving the optical member according to the magnification change operation. There is a problem in that the interlocking mechanism is difficult to design and difficult to manufacture. Also, since the mechanism for adjusting the stereoscopic effect is large and it is difficult to downsize it, the position of the object and the observer are separated,
There was a problem that it became difficult to work.

The present invention has been made in view of the above problems of the prior art. The object of the present invention is to reduce the change in stereoscopic effect due to zooming, to make the structure simple and to improve workability. It is intended to provide a good stereo microscope.

[0005]

In order to achieve the above object, a stereoscopic microscope according to the present invention comprises an objective lens and one variable magnification which is coaxial with the objective lens and is common to the left and right. Observation light determined by the pair of aperture stops, which includes an optical system and a pair of left and right observation optical systems which are arranged behind the variable power optical system and each include an aperture stop, an imaging lens, and an eyepiece lens. In a stereomicroscope whose axis passes through a position different from the optical axis of the variable power optical system, a light blocking member that blocks the outside of the pupil of the field-of-view center image determined by the pair of aperture diaphragms has at least the maximum magnification. At the time of setting, it is characterized in that it is arranged on the object side of the image formation point.

Further, according to the present invention, the objective lens, one variable magnification optical system which includes at least one image forming point and is coaxial with the objective lens, and is common to the left and right, and is disposed behind the variable magnification optical system. Each of them has an aperture stop, a pair of left and right observation optical systems including an imaging lens and an eyepiece lens, and the observation optical axis determined by the pair of aperture stops is different from the optical axis of the variable power optical system. In a stereomicroscope that is designed to pass through a place, a light blocking member that blocks the inside of the pupil of the center image of the field of view determined by the pair of aperture stops is located at the object side of the image formation point at least when the minimum magnification is set. The feature is that they are arranged.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The stereoscopic effect of a stereoscopic microscope is determined by the angle formed by the left and right optical axes (hereinafter referred to as the inward angle) at the object plane determined by the left and right entrance pupil positions. The inward angle can be represented by the angle formed by the line connecting the centers of the left and right entrance pupils and the center of the object. That is, if the entrance pupil is circular, it can be represented by the distance between its centers. When the pupil is vignetted, the midpoint of the intersection of the line segment connecting the left and right pupils and the pupil becomes the center of the pupil. In the following description, a direction connecting both optical axes in a plane perpendicular to the left and right optical axes will be referred to as a horizontal direction, and a direction perpendicular to the horizontal direction will be referred to as a vertical direction. When the left and right entrance pupils are blocked from the outside in the left-right direction, the stereoscopic effect is reduced, and when blocked from the inside in the left-right direction, the stereoscopic effect is increased. That is, the light-shielding range is expanded around the center of the left and right optical axes, and the pupil is suppressed from the outside by Kell and the increase in stereoscopic effect is suppressed, and the inside of the pupil that is contracted around the center of the left and right optical axes is Kell. The reduction of the three-dimensional effect can be suppressed.

According to the present invention, the stereoscopic effect is adjusted by utilizing this concept, and referring to FIGS.
The configuration will be described. In FIG. 1, 1 is an objective lens common to the left and right, 2 is a light-shielding member, 3 is a variable power relay optical system which is coaxial with the objective lens and has at least one image forming point I inside, 4L and 4R are variable power relay optical systems. The left and right observation aperture stops 5L and 5R arranged on the exit side of the
Left and right image forming optical systems 6L and 6R are image forming optical systems 5L and 5R which are coaxial with L and 4R and which are used to form an image so as to be stereoscopically observed by both eyes and to adjust the direction of the image. The left and right eyepieces respectively magnify the formed images. The aperture stops 4L and 4R may be installed inside the image forming optical systems 5L and 5R, respectively, or may be replaced by lens frames of lenses forming the image forming optical systems. Further, in order to prevent the stereoscopic effect from being reversed, the image forming optical system includes a reflective optical system including prisms and mirrors for replacement in the left and right light beams.

When the optical system is constructed as described above, the stereoscopic effect increases in proportion to the magnification of the variable power system. Images of the aperture diaphragms 4L and 4R of the variable power system 3 that maximize the stereoscopic effect are formed on the object side of the variable power system 3, and the light blocking member 2 is installed coaxially with the variable power system 3 near the image position. The light-shielding member 2 has a Kell diaphragm (hereinafter referred to as a stereoscopic reduction diaphragm) 2a outside the entrance pupil at the maximum magnification position of the variable power system 3 or a center of the inside of the entrance pupil at the minimum magnification position of the variable power system 3. It is a light blocking member (hereinafter referred to as a three-dimensional effect improving diaphragm) 2b. After the entrance pupil starts vignetting due to the stereoscopic reduction diaphragm, the increase in stereoscopic effect is suppressed, and after the entrance pupil begins to vignetting due to the stereoscopic effect improving diaphragm, the decrease in stereoscopic effect is suppressed. In particular, when the area of the entrance pupil is blocked by 30% or more, the effect is large. Further, when the focus adjusting function is provided inside the variable power optical system, the objective lens 1 is not necessary, and the light shielding member 2 is just in front of the variable power system 3. Further, the objective lens capable of changing the working distance (WD) can be regarded as a variable power optical system.

By the way, since this optical system has a long overall length, workability is improved by shortening the distance from the object surface to the position of the observer's eyes by using four or more reflecting surfaces as shown in FIG. It becomes a good microscope. In addition, it is convenient to use a reflecting surface for taking optical systems such as photographs and televisions, auto focus detection systems, and optical path division for a plurality of observers. In this case, it is better to provide the afocal light flux to the portion where the splitting optical system is located. Therefore, the variable power optical system is divided into a variable power optical system 3a and an imaging relay optical system 3b, and the objective lens 1, the variable power optical system 3a, the imaging relay optical system 3b, and the imaging optical systems 5L and 5R are included. The part that includes it is configured to be an afocal system.

Further, the image forming optical system includes a split prism 17 on the image side of the variable power optical system 3a in order to make the observation range and the imaging range substantially the same. Further, since it is preferable that the deviation of the pupil positions of a plurality of observers is small, the division of the optical path is preferably performed between the image forming relay optical system 3b and the image forming optical systems 5L and 5R. Further, when performing active autofocusing by irradiating infrared light, it is better not to pass through the lens system because infrared light and visible light have different wavelengths and the focal length of the lens changes. Therefore, the division of the optical path is preferably performed before the objective lens 1 or between the objective lens 1 and the variable power optical system 3a. When the optical path is split between the objective lens 1 and the variable power optical system 3a, it is difficult to form a splitting element having a good characteristic of visible light reflection by transmitting infrared light, and thus it is possible to transmit infrared light by transmitting visible light. It is preferable to install the dividing element 16.

Further, in this optical system, since a plurality of people can freely change the observation direction with the same stereoscopic effect, more complicated work can be performed in a comfortable posture. FIG. 3 shows an example of an apparatus that allows observation by a plurality of people. In this example, the prism system is configured such that the main observer is located on the transmission side of the split prism 7 and the sub-observer is located on the reflection side of the split prism 7. That is, on the main observer side, the main side aperture stops 9L and 9R and the main side imaging optical system 10 are passed through the main side prism 8.
L and 10R are provided. This main-side imaging optical system 10
L and 10R can rotate about the midpoint of the left and right optical axes as an axis in order to make the posture of the main observer easier. In this case, a rotation angle of about 60 ° is sufficient because the main observer operates the mirror body.

On the sub-observer side, the sub-side prisms 10 and 11, the sub-side rotation prism 12, the sub-side aperture diaphragms 13L and 13R, and the sub-side image formation, which are provided on the reflection side of the split prism 7, are provided. The optical system 14L, 14R and a sub eyepiece lens (not shown). Then, the entire optical system from the split prism 7 to the sub-observer can be rotated around the optical axis on the main side that transmits the split prism 7. In this case, the sub side is constructed so as not to move even if the main side rotates. Further, the entire optical system behind the sub-side prism 11 can be rotated with the output optical axis of the sub-side prism 11 as a rotation axis. Further, with the output optical axis of the sub-side prism 12 as the rotation axis, the sub-side aperture stops 13L, 13R
The subsequent optical system can be rotated. In this way, if the sub-side can rotate around the three axes, no matter how the main observer tilts the mirror body, the sub-observer will not be forced to take an observing posture.

When a plurality of observers are allowed to observe in this way, the optical path lengths from the variable power optical system to the aperture stop cannot all be the same. When the pupil position is displaced in this optical system, it appears as a difference in brightness in the left-right direction of the image plane. It can be used as long as the image is not vignetted by the stereoscopic adjustment diaphragm, but in order to obtain good stereoscopic effect with less fatigue, the ratio between the darkest part and the brightest part in the left-right direction is within 1: 3. It is necessary to be. Therefore, the aperture stop of each observer is installed so that the difference in brightness of the image plane, which is vibrated by the stereoscopic effect adjustment stop, is within 1/3.

There is also a demand for the main observer and the sub-observer to see the same object while changing the observable range depending on the role. This demand is a lens for changing the magnification in the imaging optical system. This can be achieved by inserting the system and switching the magnification. Further, since the positions of the aperture diaphragms on the side of the main observer and on the side of the sub-observer are different, it is necessary to form an afocal light beam so as not to change the observation image position by using a common imaging optical system. Is achieved by allowing the afocal variable magnification lenses 15L and 15R to be inserted in front of the imaging optical system. According to this structure, the magnification can be changed without changing the focal position regardless of whether the afocal variable magnification lens is inserted or removed. Also, since a large number of prisms are inserted in this optical system, the image center is decentered due to manufacturing errors. This decentering causes a part of the lenses of the afocal variable magnification lenses 15L and 15R to be perpendicular to the optical axis. It can be corrected by shaking in different directions.

First Embodiment FIG. 4 is a sectional view of the optical system of the present embodiment. (A) is 0.42 times, (b) is 0.48 times, and (c) is 1. The states at 0.68 times are shown respectively. FIG. 5 (a),
(B) and (c) are 0.42 times in the present embodiment,
6A, 6B, and 6C show spherical aberration characteristics at 0.48 times and 1.68 times, respectively, and FIGS. 6A, 6B, and 6C show 0.42 times, 0.48 times, and FIGS. 7 (a), 7 (b) and 7 (c) showing the astigmatism characteristics at 1.68 times, respectively.
6A and 6B are diagrams showing distortion aberration characteristics at 0.42 times, 0.48 times, and 1.68 times in the present example, respectively.

[0017]

[0019]

Magnification D1 D2 D3 Inward angle 0.42 6 28.66 45.83 3 ° 0.84 47.08 21.12 12.29 6 ° 1.68 67.64 6.01 6.84 9.9 ° A = 21, a = 5, 100 <L <200, f = 168, D = 10.5, FN = 19 Generally, the stereoscopic effect is good when the inward angle is 1 ° or more and 10 ° or less. When there was no stereoscopic adjustment diaphragm, the inward angle was 12 ° at the maximum magnification, and a microscope that was easy to observe could be constructed.

Second Embodiment FIG. 8 is a sectional view of the optical system of the present embodiment, where (a) is 0.42 times, (b) is 0.84 times, and (c) is 1. The states at 0.68 times are shown respectively. FIG. 9 (a),
(B) and (c) are 0.42 times in the present embodiment,
FIGS. 10 (a), 10 (b), and 10 (c) show the spherical aberration characteristics at 0.48 times and 1.68 times, respectively, at 0.42 times, 0.48 times, and FIGS. 11A, 11B, and 11C respectively show astigmatism characteristics at 1.68 times, at 0.42 times, 0.48 times, and 1.68 times in this embodiment. FIG. 4 is a diagram showing the distortion aberration characteristics of FIG.

[0023]

[0024]

Magnification D1 D2 D3 Inward angle 0.42 6 31.8 46.5 3 ° 0.84 48.3 23.2 12.8 6 ° 0.68 69.5 6 8.8 9.9 ° A = 21, a = 5, 100 <L <200, f = 168, D = 10.5, FN = 19 In this example, a space is provided so that a light splitting prism can be inserted between the objective lens and the variable power system of the first example, and the field curvature is improved.

Third Embodiment FIG. 12 is a cross-sectional view of the optical system of the present embodiment. (A) is a working distance (WD) = 200 and 0.45 times, (b) is WD = 200. 0.9 times, (c) WD = 200 and 1.8 times, (d) WD = 300 and 0.3 times, (e) WD = 300 and 0.6 times of,
(F) is WD = 300 and 1.2 times, (g) is WD =
400, 0.23 times, (h) is WD = 400 and 0.
(I) at 45 times shows the state at WD = 400 and 0.9 times. 13 (a), 13 (b), and 13 (c) show the values of 0 ..
(D), (e) and (f) at 9 times and 1.8 times, (g) at 0.3 times, 0.6 times and 1.2 times at WD = 300 , (H) and (i) are diagrams showing spherical aberration characteristics at WD = 400 at 0.23 times, 0.45 times and 0.9 times, respectively.

FIGS. 14 (a), (b) and (c) show (d) and (d) at 0.45 times, 0.9 times and 1.8 times when WD = 200 in this embodiment. e) and (f) are WD =
At 300 times 0.3 times, 0.6 times and 1.2 times,
(G), (h) and (i) are 0.23 at WD = 400
It is a figure which respectively shows the astigmatism characteristic at the time of magnification, 0.45 times, and 0.9 times. FIGS. 15A, 15B, and 15C show 0.9 when 0.45 times when WD = 200 in this embodiment.
(D), (e) and (f) at the time of doubling and 1.8 times are W
(G), (h) and (i) at 0.3 times, 0.6 times and 1.2 times at D = 300 are 0.
It is a figure which respectively shows the distortion aberration characteristic at the time of 23 times, 0.45 times, and 0.9 times.

[0030]

R ₁₁ = ∞ d ₁₁ = 0.5 r ₁₂ = ∞ d ₁₂ = 22.5 n ₁₂ = 1.6883 ν ₁₂ = 56.3 r ₁₃ = ∞ d ₁₃ = 2 r ₁₄ = ∞ d ₁₄ = 45 n ₁₄ = 1.7335 ν ₁₄ = 51.8 r ₁₅ = ∞ d ₁₅ = 6 r ₁₆ = 99.257 d ₁₆ = 7.5 n ₁₆ = 1.72916 ν ₁₆ = 54.7 r ₁₇ = -80.62 d ₁₇ = 5 n ₁₇ = 1.85026 ν ₁₇ = 32.3 r ₁₈ = -352.475 d ₁₈ = D4 r ₁₉ = -61.039 d ₁₉ = 2.5 n ₁₉ = 1.85026 ν ₁₉ = 32.3 r ₂₀ = 41.766 d ₂₀ = 5.7

R ₂₁ = -38.442 d ₂₁ = 4 n ₂₁ = 1.70154 ν ₂₁ = 41.2 r ₂₂ = 37.896 d ₂₂ = 5.3 n ₂₂ = 1.84666 ν ₂₂ = 23.8 r ₂₃ = -103.392 d ₂₃ = D5 r ₂₄ = 281.61 d ₂₄ = 5 n ₂₄ = 1.85026 ν ₂₄ = 32.3 r ₂₅ = 47.837 d ₂₅ = 8.9 n ₂₅ = 1.741 ν ₂₅ = 52.7 r ₂₆ = -63.449 d ₂₆ = D6 r ₂₇ = ∞ d ₂₇ = 45 n ₂₇ = 1.51633 ν ₂₇ = 64.1 r ₂₈ = ∞ d ₂₈ = 1 r ₂₉ = ∞ d ₂₉ = 61.5 n ₂₉ = 1.56883 ν ₂₉ = 56.3 r ₃₀ = ∞ d ₃₀ = 5

[0033]

WD magnification D1 D2 D3 D4 D5 D6 Inward angle 200 0.45 285.3 28.1 9 6 28.8 48.8 2.6 ° 200 0.9 285.3 28.1 9 48.3 21.2 13.6 5.2 ° 200 1.8 285.3 28.1 9 69.4 6 7.6 8.4 ° 300 0.3 386.1 13.7 23.4 6 28.8 48.3 1.7 ° 300 0.6 386.1 13.7 23.4 48.3 21.2 13.6 3.4 ° 300 1.2 386.1 13.7 23.4 69.4 6 7.6 5.6 ° 400 0.23 486.8 6.5 30.6 6 28.8 48.3 1.3 ° 400 0.45 486.8 6.5 30.6 48.3 21.2 13.6 2.6 ° 400 0.9 486.8 6.5 30.6 69.4 6 7.6 4.2 ° A = 21, a = 5, 100 <L <200, f = 210, D = 10.5, FN = 22

The following lens system was used as the imaging lens. r ₁ = 82.161 d ₁ = 2.3 n ₁ = 1.6727 ν ₁ = 32.1 r ₂ = -33.487 d ₂ = 1.7 n ₂ = 1.51633 ν ₂ = 64.1 r ₃ = -265.07 d ₃ = 2.5 r ₄ = 152.785 d ₄ = 2.3 n ₄ = 1.51633 ν ₄ = 64.1 r ₅ = -35.508 d ₅ = 1.8 n ₅ = 1.7552 ν ₅ = 27.5 r ₆ = 97.153

In this example, the three-dimensional effect was maintained well and a good image was obtained even when the WD was changed from 200 to 400.

Numerical data for the afocal variable magnification systems 15L and 15R at 1 and 1.5 times are as follows. 1 × case r ₁ = ∞ d ₁ = 2.5 n ₁ = 1.51823 ν ₁ = 59 r ₂ = -97.568 d ₂ = 5.7 r ₃ = -84.029 d ₃ = 2.5 n ₃ = 1.58913 ν ₃ = 61.2 r ₄ = 84.029 d ₄ = 2.9 r ₅ = 81.935 d ₅ = 2.3 n ₅ = 1.51633 ν ₅ = 64.1 r ₆ = -248.625

In the case of 1.5 × r ₁ = 33.07 d ₁ = 2.3 n ₁ = 1.58913 ν ₁ = 61.2 r ₂ = -33.07 d ₂ = 1 n ₂ = 1.71736 ν ₂ = 29.5 r ₃ = -97.903 d ₃ = 13.2 r ₄ = -67.205 d ₄ = 1.5 n ₄ = 1.69895 ν ₄ = 30.1 r ₅ = -20.316 d ₅ = 1 n ₅ = 1.6968 ν ₅ = 55.5

In each of the above embodiments, r₁, R_Two,
r_Three, ... is the radius of curvature of each surface of the lens, d ₁, D_Two,
d_Three, ... is the wall thickness of each lens and the air gap, n₁,
n_Two, N_Three,... Is the refractive index of each lens, ν₁, Ν_Two, Ν
_Three, ... are the numbers of each lens, and A is the three-dimensional effect adjustment diaphragm.
Diameter, a is the diameter of the aperture stop, and L is the surface closest to the image side in the variable power system.
To the center of the aperture stop (eccentricity), FN is the field of view
Is a number.

As described above, the stereoscopic microscope according to the present invention has the following features in addition to the features described in the claims.

(1) The area of the pupil is 30 due to the light shielding member.
The stereomicroscope according to claim 1 or 2, wherein the magnification is reduced by at least%.

(2) The light beam emitted from the variable power optical system is divided so that it can be observed by a plurality of observers, and each observation image is prevented from being vignetted by each aperture stop. The stereomicroscope according to claim 1 or 2, or the above (1).

(3) The stereomicroscope according to (2) above, wherein the ratio of the minimum and maximum brightness of the observed images in the left-right direction is within 1: 4.

(4) The reflecting surface is provided at least four times in order to bring the incident optical axis and the outgoing optical axis of the variable power optical system close to each other, or (1) to (3) above. ) The stereoscopic microscope according to any one of 1) to 5).

(5) The stereomicroscope according to (4) above, wherein the variable power optical system is an afocal optical system.

(6) The stereomicroscope according to the above (4), wherein the variable power optical system comprises an afocal variable power optical system and an afocal optical system for single-time imaging.

(7) The stereomicroscope according to the above (6), which includes a light splitting element arranged so as to split the light beam at the afocal portion.

(8) An afocal variable-magnification optical system is arranged on the incident side of each of the imaging lenses, respectively, and any one of the above (1) to (7). Stereo microscope.

[0050]

As described above, according to the present invention, there is no moving part other than the variable power optical system, and it is possible to suppress the change of the stereoscopic effect to an appropriate range during the variable power, which is common to the left and right. It is possible to provide a stereoscopic microscope having

[Brief description of drawings]

FIG. 1 is a diagram showing a basic configuration of an optical system of a stereoscopic microscope according to the present invention.

FIG. 2 is a perspective view showing a specific configuration of an objective lens and a variable power relay optical system portion for shortening the overall length in the optical system shown in FIG.

FIG. 3 is a diagram showing an example of the configuration of an optical system of a stereomicroscope according to the present invention configured to allow observation by a plurality of people.

FIG. 4 is a cross-sectional view of an optical system that is a first embodiment of the present invention,
(A) is at 0.42 times, (b) is at 0.48 times,
(C) shows the states at 1.68 times.

5 (a), (b) and (c) are diagrams respectively showing spherical aberration characteristics at 0.42 times, 0.48 times and 1.68 times in the first example.

6 (a), (b) and (c) are diagrams respectively showing astigmatism characteristics at 0.42 times, 0.48 times and 1.68 times in the first example. .

7 (a), (b) and (c) are diagrams respectively showing distortion aberration characteristics at 0.42 times, 0.48 times and 1.68 times in the first example.

FIG. 8 is a cross-sectional view of an optical system that is a second embodiment of the present invention,
(A) is 0.42 times, (b) is 0.84 times,
(C) shows the states at 1.68 times.

9A, 9B, and 9C are diagrams showing spherical aberration characteristics at 0.42 times, 0.48 times, and 1.68 times in the second example, respectively.

10 (a), (b) and (c) are diagrams respectively showing astigmatism characteristics at 0.42 times, 0.48 times and 1.68 times in the second example. .

11 (a), (b) and (c) are diagrams respectively showing distortion aberration characteristics at 0.42 times, 0.48 times and 1.68 times in the second example.

12A and 12B are cross-sectional views of an optical system according to a third embodiment of the present invention, in which (a) is WD = 200 and 0.45 times, and (b) is WD = 200 and 0.9 times. (C) is WD = 200 at 1.8 times, (d) is WD = 300 at 0.3 times,
(E) is WD = 300 and 0.6 times, (f) is WD =
300 times 1.2 times, (g) is WD = 400 0.2
3 times, (h) is WD = 400 and 0.45 times,
(I) is a diagram showing a state when WD = 400 and 0.9 times.

13 (a), (b) and (c) are (d) at 0.45 times, 0.9 times and 1.8 times at WD = 200 in the third embodiment. , (E) and (f) have WD = 3
At 0.3 times, 0.6 times and 1.2 times,
(G), (h) and (i) are 0.23 at WD = 400
It is a figure which respectively shows a spherical-aberration characteristic at the time of double, 0.45 time, and 0.9 time.

14 (a), (b) and (c) show (d), 0.45 times, 0.9 times and 1.8 times at WD = 200 in the third embodiment. WD = 30 in (e) and (f)
At 0, 0.3 times, 0.6 times and 1.2 times,
(G), (h) and (i) are 0.23 at WD = 400
It is a figure which respectively shows an astigmatism characteristic at the time of double, 0.45 time, and 0.9 time.

15 (a), (b) and (c) are (d), 0.45 times, 0.9 times and 1.8 times at WD = 200 in the third embodiment. WD = 30 in (e) and (f)
At 0, 0.3 times, 0.6 times and 1.2 times,
(G), (h) and (i) are 0.23 at WD = 400
It is a figure which shows the distortion aberration characteristic at the time of 2 times, 0.45 times, and 0.9 times, respectively.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Objective lens 2 Light-shielding member 3 Variable magnification relay optical system 3a Variable magnification optical system 3b Image formation relay optical system 4L, 4R Left and right observation aperture diaphragms 5L, 5R Left and right image formation optical system 6L, 6R Left and right eyepieces 7, 16,17 Split prism 8 Main side prism 9L, 9R Main side aperture stop 10,11 Sub side prism 10L, 10R Main side imaging optical system 12 Sub side rotating prism 13L, 13R Sub side aperture stop 14L, 14R Sub side imaging Optical system 15L, 15R Afocal variable magnification lens I Imaging point

Claims (2)

[Claims] 1. An objective lens, one variable-magnification optical system that includes at least one image-forming point and is coaxial with the objective lens, and is common to the left and right. The variable-magnification optical system is disposed behind the variable-magnification optical system. A pair of left and right observation optical systems including an aperture stop, an imaging lens, and an eyepiece lens are provided, and the observation optical axis determined by the pair of aperture stops passes through a place different from the optical axis of the variable power optical system. In a stereoscopic microscope, the light blocking member that blocks the outside of the pupil of the center image of the visual field determined by the pair of aperture stops, at least when the maximum magnification is set,
A stereomicroscope characterized in that it is arranged on the object side of the image formation point. 2. An objective lens, one variable-magnification optical system that includes at least one image-forming point and is coaxial with the objective lens, and is common to the left and right, and is arranged behind the variable-magnification optical system. A pair of left and right observation optical systems including an aperture stop, an imaging lens, and an eyepiece lens are provided, and the observation optical axis determined by the pair of aperture stops passes through a place different from the optical axis of the variable power optical system. In a stereoscopic microscope, the light blocking member that blocks the inside of the pupil of the center image of the field of view determined by the pair of aperture stops, at least when the minimum magnification is set,
A stereomicroscope characterized in that it is arranged on the object side of the image formation point.