JPH10170832A - Conversion lens for stereoscopic microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a conversion lens used for making the synthesized magnification of a stereoscopic microscope high by attachably/detachably arranging the conversion lens between the objective lens of the stereoscopic microscope having a pair of right and left observation optical systems and a sample. SOLUTION: The conversion lens 1 effectively compensates aberration occurring at a first lens group G1 and a third lens group G3 by arranging a meniscus- shaped second group G2 between a first lens group G1 having positive refracting power and a third lens group G3 having the positive refracting power. The lens 1 is inserted between the lens 2 of the stereoscopic microscope and the sample, so that the synthesized magnification of the stereoscopic microscope is made extremely higher than that of a conventional one, therefore, the extremely small sample can be enlarged, and also can be stereoscopically observed. By removing the lens 1 between the lens 2 and the sample, an object to be observed can be observed with large visual field, so that the object can be grasped as a whole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a conversion lens for a stereo microscope.

[0002]

2. Description of the Related Art Stereo microscopes are for observing an object independently of the left and right eyes, and are roughly classified into the following two types. One of them has a configuration as shown in FIG. 11, and is a Greeneau stereo microscope equipped with two observation optical systems in which both left and right optical axes are arranged symmetrically at a predetermined angle. As shown in FIG. 12, another stereomicroscope has a single objective lens common to the left and right arranged so that an emitted light beam forms an afocal image, and a left and right rear objective lens for observing the image with the left and right eyes. It is a Galileo stereo microscope equipped with two symmetrically arranged observation optical systems.

[0003] Unlike these general optical microscopes, these stereomicroscopes have dedicated optical paths for the right and left eyes, respectively, so that the specimen can be viewed stereoscopically as if viewed with the naked eye.

[0004] Therefore, such a stereomicroscope is effective for observing an object having a partially different thickness, such as an IC chip having irregularities, and particularly, a central portion and a peripheral portion thereof such as a cell nucleus. It is suitable for manipulating the operation of injecting some substance into its nucleus while observing a specimen with extremely different thickness.

[0005]

The stereomicroscope described above has a lower magnification than that of a general optical microscope, so that it is not possible to enlarge and observe a specimen as large as an optical microscope. Among the stereo microscopes currently on the market, the magnification obtained by multiplying the magnification of both the objective lens and the zoom lens in the stereo microscope, which is equivalent to the magnification of the objective lens of the optical system microscope, is the highest, and the Galileo stereo microscope is the highest. Is about 16 times, and about 22 times with a Greenwich stereomicroscope, which is smaller than the magnification of an optical microscope.

As described above, since a stereomicroscope generally has a low magnification, it is difficult to perform manipulations such as injecting a certain substance into a cell nucleus of an organism using the stereomicroscope. We observe while observing.

However, when observed with an optical microscope, if the focus is on the center of the nucleus, the focus may not be on the peripheral portion, and the image may be blurred. In such a case, when the numerical aperture of the microscope objective lens is reduced, the depth of focus is increased and the central portion and the peripheral portion can be easily observed at the same time, but only the central portion and the peripheral portion can be observed in the same plane. Cannot be observed in three dimensions.

However, when the needle is inserted into the cell nucleus while observing in the same plane, it is difficult to determine the distance between the needle and the cell, and it is difficult to reliably perform manipulation while observing with an optical microscope. Can not.

For this purpose, it is conceivable to observe a relatively large specimen with a stereoscopic microscope and observe only a small specimen that cannot be observed with a stereoscopic microscope with a high-magnification optical microscope. However, small specimens cannot be observed three-dimensionally because they are observed with a general optical microscope.
As described above, the method of selectively using the stereoscopic microscope and the general microscope requires two microscopes, and therefore requires a larger storage space. Changing the microscope in the middle of the observation also makes it difficult for the user to get used to moving the position of the specimen or moving the stage up and down to focus on the specimen because the operation method differs for each microscope. It takes time and the workability deteriorates.

In addition to the manipulation of the manipulation described above, for example, in the inspection of dust on an IC chip, the operation can be performed more efficiently if a high-magnification and three-dimensional observation can be performed. Therefore, the effectiveness of a high-power stereo microscope is extremely high.

As a method for increasing the magnification of a stereo microscope, it is conceivable to increase the magnification of an objective lens or a zoom lens.

However, when the magnification of the zoom lens is increased, the total length of the zoom lens becomes longer, and the outer diameter of the lens becomes larger because the light beam becomes thicker. Therefore, the zoom lens becomes large and a large space for incorporating the zoom lens becomes large. Will be needed. Therefore, the size of the stereo microscope itself becomes large, which is disadvantageous in terms of system and storage. Also, as the total length of the zoom lens increases, the eye point increases and the operability deteriorates. Also, if the magnification of the zoom lens is increased, the magnification of the objective lens cannot be increased due to the optical performance.

On the other hand, when the magnification of the objective lens is increased, the number of lenses must be increased or the outer diameter of the lens must be increased in order to maintain good optical performance in all states from high magnification to low magnification. The manufacturing cost is high and the stereomicroscope is expensive.

In particular, to design an objective lens for a stereomicroscope having a magnification of about 2 times or more, which is currently known as an objective lens having excellent optical performance from on-axis to off-axis in all zoom states. Is very difficult. In order to realize such a high-magnification objective lens for a stereomicroscope, it is necessary to reduce the magnification of a zoom lens to be combined. The maximum magnification of the objective lens currently commercialized is about 2 times when the magnification of the zoom lens is 7.5 times.

As described above, when the magnification of the zoom lens is increased, the magnification of the objective lens cannot be sufficiently increased, and when the magnification of the objective lens is increased, the magnification of the zoom lens cannot be sufficiently increased. That is, in a stereomicroscope, it has been difficult to increase the magnification obtained by multiplying the magnification of the zoom lens by the magnification of the objective lens.

The present invention has been made in view of the above points, and provides a conversion lens used to increase the overall magnification of a stereomicroscope.

[0017]

A conversion lens for a stereomicroscope according to the present invention is characterized in that it is detachably disposed between an objective lens and a specimen of a stereomicroscope having a pair of right and left observation optical systems.

According to the conversion lens for a stereomicroscope of the present invention, by inserting the lens between the objective lens of the stereomicroscope and the sample, the overall magnification of the stereomicroscope can be made extremely high and the extremely small sample can be obtained. Is magnified and can be observed three-dimensionally, thereby enabling manipulation operation and the like on a minute object.

Further, by removing the conversion lens from between the objective lens and the sample, the object to be observed can be observed in a wide field of view and the object can be grasped as a whole.

The conversion lens for a stereomicroscope according to the present invention is detachably disposed between an objective lens and a specimen of a stereomicroscope having an observation optical system having a zooming mechanism such as a zoom optical system. The entire aberration including the observation optical system is favorably corrected in an area having a magnification at least higher than the magnification at the center of the magnification range of the magnification mechanism.

In the case of the above-mentioned conversion lens, it is desirable that aberrations be satisfactorily corrected particularly in a certain region having the highest magnification in the zoom range of the zoom mechanism.

As described above, when the conversion lens of the present invention is used in a stereomicroscope provided with an observation optical system having a magnification changing mechanism, the conversion lens of the present invention is inserted into a low magnification region of the magnification changing mechanism. However, the overall magnification does not increase much, and there is little merit by using a conversion lens. Therefore, it is extremely effective to use the conversion lens of the present invention in a high magnification region of the zoom mechanism.

On the other hand, the whole aberration is better corrected in a part of the area, rather than designed so that the whole aberration is well corrected over the entire zoom range of the stereo microscope using the conversion lens. This is advantageous in that it is easy to correct aberrations, and it is possible to realize a conversion lens in which the entire aberration is successfully corrected by combining a stereo microscope and a conversion lens with a simple configuration using a small number of lenses. In this case, it is desirable that the entire aberration be good at least in a region having a magnification higher than the center of the zoom range, and the whole aberration is particularly well corrected near the highest magnification. Is preferred.

The conversion lens according to the present invention comprises, in order from the object side, a first lens group having a positive refractive power, a second lens group having a meniscus shape, and a third lens group having a positive refractive power.
It is desirable to form a group. By arranging the meniscus-shaped lens in the conversion lens in this manner, aberrations such as field curvature can be satisfactorily corrected.

If all three lens groups are constituted by single lenses, the lens system can be constituted by a small number of lenses.
One lens group can be composed of a plurality of lenses. For example, it is preferable to use a cemented lens as the second lens group and a cemented lens having a meniscus shape for correcting chromatic aberration as well as aberration such as field curvature.

In the conversion lens of the present invention, if the three lens units are configured and the meniscus lens of the second lens unit is configured such that the convex surface faces the object side, aberrations such as field curvature and the like can be corrected. The entire lens system can have a simple configuration while ensuring a long working distance.

In the meniscus lens of the present invention, it is preferable that the surface closest to the object be a flat surface or a concave surface because a sufficient NA can be secured and the working distance can be increased.

Also, in the conversion lens of the present invention, by making the outer diameter of the lens closest to the object side smaller than the outer diameter of the other lenses, the shape of the tip of the conversion lens can be made thinner, and it is possible to observe the enlarged image with a microscope. Work becomes easier.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a conversion lens for a stereomicroscope according to the present invention will be described.

The first embodiment of the present invention is as shown in FIGS. FIG. 1 shows the configuration of an optical system in which the conversion lens 1 and the objective lens 2 of the first embodiment are combined, and FIG. 2 shows the entire stereomicroscope using the conversion lens 1 of the present invention. FIG. 3 is a view showing a lens holding frame of a conversion lens 1 and an objective lens 2, and shows a configuration in which the conversion lens 1 and the objective lens 2 are detachably connected.

The stereo microscope shown in FIG.
From the conversion lens 1 and the objective lens 2
, And is emitted as parallel light through an afocal zoom lens, and is imaged by the imaging lens 4. The image formed by the imaging lens 4 can be observed through the left and right eyepieces 5 and 6.

In the optical system shown in FIG. 2, if the conversion lens is removed from the optical path, the sample 10 can be observed at the original magnification of the stereomicroscope. If the conversion lens 1 is mounted as shown in FIG. Can be observed at

FIG. 1 is a cross-sectional view of Example 1 of an optical system in which a conversion lens 1 and an objective lens 2 are combined according to the first embodiment. Data of this example is as follows. r ₁ = −249.244 d ₁ = 2.9 n ₁ = 1.83400 v ₁ = 37.17 r ₂ = 61.037 d ₂ = 8.6 n ₂ = 1.49700 v ₂ = 81.61 r ₃ = -14.328 d ₃ = 0.4 r ₄ = 39.243 d ₄ = 22.3 _{n 3 = 1.49700 ν 3 = 81.61} r 5 = -43.481 d 5 = 3.4 n 4 = 1.71850 ν 4 = 33.52 r 6 = 64.339 d 6 = 2.7 r 7 = -6321.393 d 7 = 4.0 n 5 = 1.75500 ν 5 = 52.33 _{r 8 = 32.302 d 8 = 9.9} n 6 = 1.72342 ν 6 = 37.95 r 9 = -85.233 d 9 = 2.0 r 10 = 137.710 d 10 = 9.8 n 7 = 1.62280 ν 7 = 57.05 r 11 = -65.473 d 11 = 1.1 _{r 12 = -55.905 d 12 = 5.5} n 8 = 1.64450 ν 8 = 40.82 r 13 = 55.905 d 13 = 11.3 n 9 = 1.49700 ν 9 = 81.61 r 14 = -110.616 d 14 = 2.1 r 15 = 59.222 d 15 = 21.3 _{n 10 = 1.65016 ν 10 = 39.39} r 16 = -33.156 d 16 = 5.5 n 11 = 1.64450 ν 11 = 40.82 r 17 = 51.848 d 17 = 4.3 r 18 = 248.625 d 18 = 6.8 n 12 = 1.48749 ν 12 = 70.21 r ₁₉ = -87.040 However, r _1, r _2, ··· Les The radius of curvature of each side's, d
_.. , D ₂ ,...
₁ , n ₂ ,... Are the refractive indices of the respective lenses, ν ₁ , ν ₂ ,.
Is the Abbe number of each lens. As shown in the first embodiment, in the present invention, a conversion lens 1 for enlarging a magnification is arranged between a specimen 10 and an objective lens 2. The lens configuration of the conversion lens 1 includes, in order from the specimen side, a first lens group G1 having a positive refractive power in which a concave lens and a convex lens are bonded, and a second lens group of a meniscus-shaped cemented lens in which a convex lens and a concave lens are bonded. G2
And a third lens group G3 having a positive refractive power of a cemented lens obtained by cementing a concave lens and a convex lens.

Also, as shown in FIG.
The frame 11 for holding the objective lens 2 is connected to the distal end side of the holding frame 12 for the objective lens 2 and is fixed by a screw portion 13, so that the conversion lens 1 can be detachably attached to the objective lens 2. I have. The outer diameter of the conversion lens 1 is large enough to secure an effective diameter such that an image height of approximately half the image height when the zoom magnification is the lowest can be formed.

In the optical system of the first embodiment, by attaching the conversion lens 1, the total magnification of the stereomicroscope can be increased to about 2.5 times the total magnification before the conversion lens is mounted.

The conversion lens according to the first embodiment has a meniscus second group disposed between the first lens group G1 having a positive refractive power and the third lens group G3 having a positive refractive power. An aberration generated in the group G1 and the third lens group G3 is effectively corrected. Also, the provision of the second lens group G2 increases the working distance (WD).

As described above, since the outside diameter of the conversion lens is set to approximately half the image height at the minimum zoom magnification, the angle θ from the sample 10 as shown in FIG.
Is 40 °, so that when the manipulator is operated, the interference between the needle and the conversion lens can be prevented as much as possible. Moreover, since the outside diameter of the conversion lens 1 is small, when the sample is removed from the stereoscopic microscope and the sample is directly viewed, it is only necessary to move the eye slightly to the sample side, which is extremely convenient in operation.

FIG. 4 shows a modification of the conversion lens 1 shown in FIG. 3, in which the angle θ is increased by reducing the outer diameter of each lens constituting the conversion lens, and θ = 50 °. .

FIG. 5 shows the aberration situation of the optical system of the first embodiment. FIG. 5A is an aberration curve diagram when the conversion lens 1 and the objective lens 2 are combined, and FIG. And both are astigmatism and coma. These aberration curves are based on reverse tracking, that is, when parallel rays are incident from the image side (right side in FIG. 1) to form an image on the object plane. As is clear from FIGS. 5A and 5B, the aberration curves have the same shape when the conversion lens and the objective lens are combined and when the objective lens alone is used. That is, by attaching the conversion lens of the present invention, it is possible to increase the magnification while maintaining the aberration level (optical performance) of the objective lens. If the aberrations of the conversion lens and the objective lens are corrected well as in this embodiment, different combinations of the conversion lens and the objective lens become possible, and the lens system combining the conversion lens and the objective lens is also excellent. Optical performance can be maintained. That is, the conversion lens of the present invention performs aberration correction to a level that is more severe than the level of aberration allowed on the appearance of an image. It is very good, and there is no specially designed objective lens as described above, and the total aberration situation is very well maintained even when combined with another different objective lens.

FIG. 6 is a sectional view of a conversion lens for a stereomicroscope according to a second embodiment of the present invention, in which a conversion lens 1 'and an objective lens 2 identical to the objective lens of the first embodiment are combined as in FIG. FIG.
The lens data of the optical system according to the second embodiment is as follows. r ₁ = -50.242 d ₁ = 6.5 n ₁ = 1.51633 v ₁ = 64.15 r ₂ = -102.722 d ₂ = 6.8 n ₂ = 1.62280 v ₂ = 57.04 r ₃ = -13.505 d ₃ = 0.4 r ₄ = 30.245 d ₄ = _{19.4 n 3 = 1.49700 ν 3 =} 81.61 r 5 = -19.424 d 5 = 5.1 n 4 = 1.71850 ν 4 = 33.52 r 6 = 56.501 d 6 = 2.7 r 7 = 584.034 d 7 = 5.3 n 5 = 1.77250 ν 5 = 49.60 _{r 8 = 32.537 d 8 = 8.6} n 6 = 1.72342 ν 6 = 37.95 r 9 = -58.803 d 9 = 2.8 r 10 = 139.139 d 10 = 8.7 n 7 = 1.64100 ν 7 = 56.93 r 11 = -79.696 d 11 = 1.2 _{r 12 = -63.420 d 12 = 5.5} n 8 = 1.64450 ν 8 = 40.82 r 13 = 51.128 d 13 = 12.2 n 9 = 1.49700 ν 9 = 81.61 r 14 = -121.073 d 14 = 1.3 r 15 = 55.650 d 15 = 21.5 _{n 10 = 1.65016 ν 10 = 39.39} r 16 = -35.247 d 16 = 5.5 n 11 = 1.64450 ν 11 = 40.82 r 17 = 48.693 d 17 = 3.9 r 18 = 161.881 d 18 = 7.4 n 12 = 1.48749 ν 12 = 70.21 r ₁₉ = -94.076 conversion les of example 2 In order from the specimen side, a first lens group G1 having a positive refractive power of a cemented lens of a concave lens and a convex lens, a second lens group G2 of a meniscus lens of a cemented lens of a convex lens and a concave lens, and a concave lens and a convex lens are cemented. And a third lens group G3 having a positive refractive power of the cemented lens. The optical system according to the second embodiment can enlarge the total magnification of the stereomicroscope before mounting the conversion lens by three times by mounting the conversion lens.

FIGS. 7 to 9 show a second embodiment of the present invention, in which a mounting means for mounting a conversion lens on an objective lens is shown. Different from form.

In the second embodiment, a key receiving portion 26 is provided on the objective lens side of the holding frame 25 for the conversion lens, while a key portion 28 is provided on the conversion lens side of the holding frame 27 for the objective lens. It is provided. And
The key portion 28 and the key receiving portion 26 are set to be lightly fitted. FIG. 8 shows the side of the objective lens which is connected to the conversion lens. As shown in FIG. 8, a stopper portion 30 is formed on the holding frame 27. FIG. 9 is a diagram showing a side of the conversion lens which is coupled to the objective lens. The projection 31 of the holding frame 25 is brought into contact with the conversion lens so that the optical axis of the conversion lens coincides with the optical axis of the objective lens. After the conversion lens having the above structure is fitted to the key receiving portion 26 of the conversion lens of the objective lens, the positional relationship between the two is fixed by the fixing screw 29. With such a structure, the conversion lens can be easily attached to and detached from the objective lens.

FIG. 10 shows a third embodiment of the present invention. The means for fixing the conversion lens to the objective lens is different from the other first and second embodiments.

As shown in FIG. 10, a disk 38 having a rotation axis 39 is arranged on the side of the objective lens 2 so as to be rotatable about the rotation axis 39. This disk 38
In addition to the conversion lens 1, another conversion lens 36 is detachably attached.

In the stereo microscope having the above configuration,
When the disk 38 is rotated around the rotation axis 39, the optical axis of the conversion lens 36 can be made coincident with the optical axis of the objective lens 2, whereby the conversion lens 1 can be switched to the conversion lens 36.

In the third embodiment, a plurality of conversion lenses having different magnifications are mounted on a disc 38,
By rotating the disk 38, observation using a necessary conversion lens can be performed. As a result, the total magnification of the stereomicroscope can be enlarged to a plurality of different magnifications, so that observation at a magnification most suitable for observation becomes possible. Further, by providing a hole in the disk 38 that enables observation only with the objective lens 2, observation with only the objective lens 2 becomes possible. In other words, according to the stereoscopic microscope of this embodiment, observation with a relatively wide field of view at low magnification using only the objective lens 2 and observation at high magnification with the addition of a conversion lens are performed. The observation can be switched by selecting the conversion lens.

The conversion lens for a stereoscopic microscope according to the present invention described above is described in each claim of the present invention, and a conversion lens having the structure described in each of the following claims can also achieve the object of the present invention. It is clear.

(1) A conversion lens for a stereo microscope, wherein the meniscus lens of the second group is arranged with the convex surface facing the object side in the lens system according to claim 1.

(2) A conversion lens for a stereomicroscope, wherein the most object side surface is a flat surface or a concave surface in the lens system according to claim 3.

(3) In the lens system according to claim 1, wherein the outer diameter of the lens closest to the object is smaller than the outer diameters of the other lenses. lens.

[0051]

According to the present invention, an optical system (conversion lens) is arranged between a specimen and an objective lens.
By increasing the total magnification, an extremely small object can be sufficiently enlarged and three-dimensionally observed. The optical system disposed between the specimen and the objective lens is detachable or switchable, so that it is possible to switch between low magnification and high magnification or to switch between high magnifications and different appropriate magnifications as necessary. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view in a state where an objective lens according to a first embodiment of the present invention is combined.

FIG. 2 is a diagram showing an outline of an optical system of a stereo microscope using the conversion lens of the present invention.

FIG. 3 is a diagram showing a lens barrel having a configuration in which the first embodiment of the present invention and an objective lens are combined.

FIG. 4 is a diagram showing another lens barrel configured to combine the first embodiment of the present invention and an objective lens.

FIG. 5 is an aberration curve diagram according to the first embodiment of the present invention.

FIG. 6 is a sectional view showing a state where the objective lens according to the second embodiment of the present invention is combined with the objective lens.

FIG. 7 is a diagram showing a mechanism for attaching and detaching the conversion lens of the present invention to an objective lens.

FIG. 8 is a diagram showing a configuration of an attachment / detachment mechanism shown in FIG. 7 on an objective lens side.

9 is a diagram showing a configuration of the attachment / detachment mechanism shown in FIG. 7 on a conversion lens side.

FIG. 10 is a diagram showing another example of a mechanism for attaching / detaching the conversion lens of the present invention to / from the objective lens.

FIG. 11 is a diagram showing an optical system of a conventional stereomicroscope.

FIG. 12 is a diagram showing an optical system of another conventional stereomicroscope.

Claims (3)

[Claims] A conversion lens for a stereomicroscope removably disposed on the object side of an objective lens of a stereomicroscope having a pair of right and left observation optical systems. 2. The observation optical system of the stereomicroscope has a magnification changing mechanism capable of changing an observation magnification, and the conversion lens is at least on a higher magnification side than a center of a variable range in the magnification change mechanism. 2. The conversion lens for a stereomicroscope according to claim 1, wherein the entire aberration including the observation optical system is satisfactorily corrected in an arbitrary region. 3. The conversion for a stereomicroscope according to claim 2, comprising a first lens unit having a positive refractive power, a second lens unit including a meniscus lens, and a third lens unit having a positive refractive power in order from the object side. lens.