Microscope tube and microscope

Abstract

The utility model provides a microscope tube lens and a microscope. The microscope tube lens comprises a first lens group, a second lens group and a third lens group which are sequentially arranged on the same optical axis from an object side to an image side; the first lens group, the second lens group and the third lens group respectively comprise at least two lenses, and the refractive indexes of the at least two lenses in each lens group are different; the surface of the first lens group facing the object side is convex, and the surface of the first lens group facing the image side is concave. The surface of the second lens group facing the object side is concave, and the surface of the second lens group facing the image side is convex. The surface of the third lens group facing the object side is concave, and the surface of the third lens group facing the image side is convex. According to the technical scheme of the utility model, the specific parameters and structures of the lenses are set, so that the image space field of view of the microscope tube lens is 40.272 mm, the focal length of the microscope tube lens is 200 mm, the imaging quality and the image space field of view are improved, and the overall performance of the microscope is further improved. Aberration correction is good, and vignetting is avoided; the self-design is realized, and the problem that the existing tube lens cannot be well matched with semiconductor measurement equipment is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of microscope, in particular to a microscope tube lens and microscope. BACKGROUND

[0002] Under the condition of the rapid development of micro-nano processing technology, the feature size of integrated circuit is getting smaller and smaller, in order to adapt to the integrated requirement of gradually improved semiconductor measuring equipment, it is necessary to use microscope tube lens designed for specific needs, at present, some foreign manufacturers can provide conventional microscope tube lens, its image side field of view is generally 22mm, 24mm, 30mm.

[0003] But these foreign manufacturers will not provide high-order optical parameters of microscope tube lens, which leads to the fact that the microscope tube lens cannot be designed in the semiconductor measuring equipment, affecting the integration of the system, and even reducing the imaging quality of the optical system. In addition, the image side field of view of the conventional microscope tube lens is less than 30mm, which cannot meet the large field of view measurement demand of semiconductor measuring equipment. UTILITY MODEL CONTENTS

[0004] An object of the utility model is to effectively improve the imaging quality and image side field of view of the microscope tube lens, and further improve the overall performance of the microscope.

[0005] A further object of the utility model is to realize the independent design of the microscope tube lens, so that the microscope tube lens can better match the semiconductor measuring equipment.

[0006] In particular, the utility model provides a microscope tube lens, which comprises: first lens group, second lens group and third lens group arranged in order from object side to image side along the same optical axis; the first lens group, the second lens group and the third lens group respectively comprise at least two lenses, and the refractive index of the at least two lenses in each lens group is different; the first lens group is convex towards the object side and concave towards the image side; the second lens group is concave towards the object side and convex towards the image side; and the third lens group is concave towards the object side and convex towards the image side.

[0007] Optionally, 0.55 < fG1 / f < 0.75, 0.85 < fG2 / f < 1.05, and -0.45 < fG3 / f < -0.25, wherein fG1 is the focal length of the first lens group, fG2 is the focal length of the second lens group, fG3 is the focal length of the third lens group, and f is the focal length of the microscope tube lens.

[0008] Optionally, the first lens group is a doublet lens with positive refractive power, comprising a first lens and a second lens from the object side; the surface of the first lens facing the object side is convex, and the surface facing the image side is convex; the surface of the second lens facing the object side is concave, and the surface facing the image side is concave; the second lens group is a doublet lens with positive refractive power, comprising a third lens and a fourth lens from the object side; the surface of the third lens facing the object side is concave, and the surface facing the image side is convex; the surface of the fourth lens facing the object side is concave, and the surface facing the image side is convex; the third lens group is a doublet lens with negative refractive power, comprising a fifth lens and a sixth lens from the object side; the surface of the fifth lens facing the object side is concave, and the surface facing the image side is convex; the surface of the sixth lens facing the object side is concave, and the surface facing the image side is convex.

[0009] Optionally, the first lens and the fifth lens satisfy the following conditions: 1.50 < nd < 1.60, 58 < Vd < 72, the second lens, the third lens, and the fourth lens satisfy the following conditions: 1.60 < nd < 1.78, 25 < Vd < 62, and the sixth lens satisfies the following conditions: 1.92 < nd < 1.96, 27 < Vd < 35, wherein nd is the refractive index at a wavelength of 587.6 nm, and Vd is the Abbe number at a wavelength of 587.6 nm.

[0010] Optionally, the refractive index of the first lens is 1.55, and the Abbe number is 70; the refractive index of the second lens is 1.68, and the Abbe number is 33; the refractive index of the third lens is 1.74, and the Abbe number is 28; the refractive index of the fourth lens is 1.6, and the Abbe number is 61; the refractive index of the fifth lens is 1.56, and the Abbe number is 58; and the refractive index of the sixth lens is 1.92, and the Abbe number is 31.

[0011] Optionally, the surface of the first lens facing the object side is a first mirror surface, the cemented surface of the first lens and the second lens is a second mirror surface, the surface of the second lens facing the image side is a third mirror surface, the surface of the third lens facing the object side is a fourth mirror surface, the cemented surface of the third lens and the fourth lens is a fifth mirror surface, the surface of the fourth lens facing the image side is a sixth mirror surface, the surface of the fifth lens facing the object side is a seventh mirror surface, the cemented surface of the fifth lens and the sixth lens is an eighth mirror surface, and the surface of the sixth lens facing the image side is a ninth mirror surface; the radius of curvature of the first mirror surface and the third mirror surface is positive; and the radius of curvature of the second mirror surface, the fourth mirror surface, the fifth mirror surface, the sixth mirror surface, the seventh mirror surface, the eighth mirror surface, and the ninth mirror surface is negative.

[0012] Optionally, the radius of curvature of the first mirror is 55mm, the mirror distance between the first mirror and the second mirror is 12mm; the radius of curvature of the second mirror is-68mm, the mirror distance between the second mirror and the third mirror is 11mm; the radius of curvature of the third mirror is 885mm, the mirror distance between the third mirror and the fourth mirror is 30mm; the radius of curvature of the fourth mirror is-1840mm, the mirror distance between the fourth mirror and the fifth mirror is 9mm; the radius of curvature of the fifth mirror is-50mm, the mirror distance between the fifth mirror and the sixth mirror is 9mm; the radius of curvature of the sixth mirror is-240mm, the mirror distance between the sixth mirror and the seventh mirror is 20mm; the radius of curvature of the seventh mirror is-45mm, the mirror distance between the seventh mirror and the eighth mirror is 7.5mm; the radius of curvature of the eighth mirror is-28mm, the mirror distance between the eighth mirror and the ninth mirror is 5.5mm; the radius of curvature of the ninth mirror is-90mm, and the mirror distance between the ninth mirror and the image plane is 65mm.

[0013] According to another aspect of the utility model, a microscope is also provided, comprising any one of the above microscopes.

[0014] The utility model discloses a microscope tube lens, through the specific parameter and the structure of each lens are set up, make the image side field of view of microscope tube lens 40.272mm, focal length is 200mm, improve the imaging quality while, make it possess higher than the image side field of view of conventional tube lens, can satisfy the large field of view measurement demand of semiconductor measuring equipment, improve the overall performance of microscope.

[0015] Further, the utility model discloses a microscope tube lens, aberration correction is good, and there is no vignetting, and completely realizes independent design, solves the problem that the existing tube lens can not match semiconductor measuring equipment well.

[0016] According to the detailed description of the specific embodiments of the utility model in the following combined with the drawings, the above and other purposes, advantages and characteristics of the utility model will be more clear to those skilled in the art. BRIEF DESCRIPTION OF DRAWINGS

[0017] Some specific embodiments of the utility model will be described in detail hereinafter with reference to the drawings in an exemplary but not restrictive manner.The same reference signs in the drawings indicate the same or similar components or parts.Those skilled in the art should understand that these drawings are not necessarily drawn to scale.In the drawings:

[0018] Figure 1 It is the structure schematic diagram of microscope tube lens according to one embodiment of the utility model;

[0019] Figure 2 It is the full field of view full wavelength point array diagram of microscope tube lens according to one embodiment of the utility model;

[0020] Figure 3 is a full field transfer function curve diagram of the microscope tube lens according to one embodiment of the present utility model;

[0021] Figure 4 is a full field non-vignetting ray fraction diagram of the microscope tube lens according to one embodiment of the present utility model; and

[0022] Figure 5 is a field curvature distortion diagram of the microscope tube lens according to one embodiment of the present utility model. DETAILED DESCRIPTION

[0023] The embodiment provides a microscope tube lens, which can effectively improve imaging quality and image field of the microscope tube lens, and further improve overall performance of the microscope. Figure 1 is a structural schematic diagram of the microscope tube lens according to one embodiment of the present utility model. As shown in Figure 1 The microscope tube lens of the embodiment comprises: a first lens group G1, a second lens group G2 and a third lens group G3 which are sequentially arranged along an optical axis from an object side to an image side.

[0024] The first lens group G1, the second lens group G2 and the third lens group G3 each comprise at least two lenses, and the refractive indexes of the at least two lenses in each lens group are different. The first lens group G1 is convex on the object side and concave on the image side; the second lens group G2 is concave on the object side and convex on the image side; and the third lens group G3 is concave on the object side and convex on the image side. Figure 1 OBJ in the formula is an objective lens.

[0025] In one specific embodiment, 0.55 < fG1 / f < 0.75, 0.85 < fG2 / f < 1.05, and -0.45 < fG3 / f < -0.25, wherein fG1 is the focal length of the first lens group G1, fG2 is the focal length of the second lens group G2, fG3 is the focal length of the third lens group G3, and f is the focal length of the microscope tube lens.

[0026] In a preferred embodiment, the first lens group G1 is a doublet lens with positive refractive power, including a first lens L1 and a second lens L2 from the object side; the first lens L1 is convex on the object side and convex on the image side; the second lens L2 is concave on the object side and concave on the image side. Positive refractive power refers to the refractive power of the optical system that converges light rays, and its value is greater than zero. The optical system with positive refractive power will make the light rays converge, that is, the light beam will become more concentrated after passing through the system. Doublet lens refers to a combination lens formed by two lenses glued together, which can achieve better imaging effect through the combination of the two lenses. Compared with a single lens, a doublet lens can achieve a shorter focal length, a larger magnification, better imaging quality, and higher axial resolution.

[0027] The second lens group G2 is a doublet lens with positive refractive power, including a third lens L3 and a fourth lens L4 from the object side; the third lens L3 is concave on the object side and convex on the image side; the fourth lens L4 is concave on the object side and convex on the image side.

[0028] The third lens group G3 is a doublet lens with negative refractive power, including a fifth lens L5 and a sixth lens L6 from the object side; the fifth lens L5 is concave on the object side and convex on the image side; the sixth lens L6 is concave on the object side and convex on the image side. The optical system with negative refractive power will make the light rays become more divergent, that is, the light beam will become more dispersed after passing through the system.

[0029] In a specific embodiment, the first lens L1 and the fifth lens L5 both satisfy the following conditions: 1.50 < nd < 1.60, 58 < Vd < 72, the second lens L2, the third lens L3, and the fourth lens L4 all satisfy the following conditions: 1.60 < nd < 1.78, 25 < Vd < 62, and the sixth lens L6 satisfies the following conditions: 1.92 < nd < 1.96, 27 < Vd < 35, where nd is the refractive index at a wavelength of 587.6 nm, and Vd is the Abbe number at a wavelength of 587.6 nm.

[0030] In a preferred embodiment, the specific values of the refractive index and Abbe number of the first lens L1 to the sixth lens L6 can refer to Table 1. As shown in Table 1, the refractive index of the first lens L1 is 1.55, and the Abbe number is 70; the refractive index of the second lens L2 is 1.68, and the Abbe number is 33; the refractive index of the third lens L3 is 1.74, and the Abbe number is 28; the refractive index of the fourth lens L4 is 1.6, and the Abbe number is 61; the refractive index of the fifth lens L5 is 1.56, and the Abbe number is 58; the refractive index of the sixth lens L6 is 1.92, and the Abbe number is 31.

[0031] Table 1

[0032]

[0033]

[0034] In a specific embodiment, the surface of the first lens L1 facing the object side is the first mirror surface S1, the cemented surface of the first lens L1 and the second lens L2 is the second mirror surface S2, and the surface of the second lens L2 facing the image side is the third mirror surface S3. The surface of the third lens L3 facing the object side is the fourth mirror surface S4, the cemented surface of the third lens L3 and the fourth lens L4 is the fifth mirror surface S5, and the surface of the fourth lens L4 facing the image side is the sixth mirror surface S6. The surface of the fifth lens L5 facing the object side is the seventh mirror surface S7, the cemented surface of the fifth lens L5 and the sixth lens L6 is the eighth mirror surface S8, and the surface of the sixth lens L6 facing the image side is the ninth mirror surface S9.

[0035] In a preferred embodiment, the specific values of the radii of curvature of the first mirror surface S1 to the ninth mirror surface S9 and the mirror surface distances between adjacent two mirror surfaces can refer to Table 2. As shown in Table 2, the radius of curvature of the first mirror surface S1 is 55 mm, the mirror surface distance between the first mirror surface S1 and the second mirror surface S2 is 12 mm; the radius of curvature of the second mirror surface S2 is -68 mm, the mirror surface distance between the second mirror surface S2 and the third mirror surface S3 is 11 mm; the radius of curvature of the third mirror surface S3 is 885 mm, the mirror surface distance between the third mirror surface S3 and the fourth mirror surface S4 is 30 mm; the radius of curvature of the fourth mirror surface S4 is -1840 mm, the mirror surface distance between the fourth mirror surface S4 and the fifth mirror surface S5 is 9 mm; the radius of curvature of the fifth mirror surface S5 is -50 mm, the mirror surface distance between the fifth mirror surface S5 and the sixth mirror surface S6 is 9 mm; the radius of curvature of the sixth mirror surface S6 is -240 mm, the mirror surface distance between the sixth mirror surface S6 and the seventh mirror surface S7 is 20 mm; the radius of curvature of the seventh mirror surface S7 is -45 mm, the mirror surface distance between the seventh mirror surface S7 and the eighth mirror surface S8 is 7.5 mm; the radius of curvature of the eighth mirror surface S8 is -28 mm, the mirror surface distance between the eighth mirror surface S8 and the ninth mirror surface S9 is 5.5 mm; and the radius of curvature of the ninth mirror surface S9 is -90 mm, the mirror surface distance between the ninth mirror surface S9 and the image surface is 65 mm.

[0036] Table 2

[0037] Mirror name Radius of curvature (mm) Mirror distance (mm) First mirror S1 55.00 12.00 Second mirror S2 -68.00 11.00 Third mirror S3 885.00 30.00 Fourth mirror S4 -1840.00 9.00 Fifth mirror S5 -50.00 9.00 Sixth mirror S6 -240.00 20.00 Seventh mirror S7 -45.00 7.50 Eighth mirror S8 -28.00 5.50 Ninth mirror S9 -90.00 65.00

[0038] According to the specific parameters and structures of each lens in the above Tables 1 and 2, the field of view of the microscope tube lens on the image side can be 40 mm, and the focal length can be 200 mm. The microscope tube lens of the present embodiment has a larger field of view on the image side than conventional tube lenses, and is completely self-designed, solving the problem that existing tube lenses cannot be well matched with semiconductor measurement equipment.

[0039] Figure 2 is a full field full wavelength point array diagram of the microscope tube lens according to an embodiment of the present application. Figure 2 The focusing of light with a wavelength of 0.486133 to 0.656273 um at the focal point under different image field of view is shown.The image field of view half of view field (1) is 0.000 mm, the image field of view half of view field (2) is 10.015 mm, and the image field of view half of view field (3) is 20.136 mm, so the image field of view of view field (1), (2) and (3) is 0 mm, 20.03 mm and 40.272 mm respectively.The data during testing is as follows: the Airy disk radius (diffraction limit) is 12.670 um, the RMS radius (root mean square) when the view field is (1) is 0.492 um, the GEO radius (maximum) is 1.209 um, the RMS radius when the view field is (2) is 0.755 um, the GEO radius is 2.263 um, the RMS radius when the view field is (3) is 0.570 um, and the GEO radius is 1.339 um.

[0040] The RMS radius is also called root mean square spot radius, which is an index for describing the size of a light beam, and is obtained by taking the square root of the second average of the light intensity distribution.The GEO radius (Geometric Optical Radius) represents the radius of the smallest central circle containing all light rays.Specifically, the GEO radius is the smallest central circle radius that can meet the requirement that all light rays fall within its range. Figure 2 It can be seen that the focused spots of light with different wavelengths under different view fields are within the Airy disk range, and the point array diagram is better than the diffraction limit, which indicates that the aberration of the microscope tube lens of the embodiment is well controlled, and basically reaches the system limit.

[0041] Figure 3 is a full field transfer function curve diagram of the microscope tube lens according to an embodiment of the present application. Figure 3 The ordinate of is the modulus value of the normalized transfer function, and the abscissa is the spatial frequency, with the unit of lp / mm.The outermost line is the transfer function curve of the system under the diffraction limit.As shown in Figure 3 , the transfer function curves of the meridian and sagittal planes of the microscope tube lens of the embodiment under the conditions that the image field of view is 0 mm, 20.03 mm and 40.272 mm indicate that the on-axis field transfer function curve and the off-axis field transfer function curve are close to the diffraction limit, which indicates that the imaging contrast of the full field of the optical system is very high, and the imaging level is clear.

[0042] Figure 4 is a full field un-vignetted ray fraction diagram of the microscope tube lens according to an embodiment of the present application. Figure 4 The abscissa in indicates the field of view, and the ordinate indicates the un-vignetted ray fraction. Figure 4It shows that the fraction of non-vignetted light in the entire field of view of the microscope tube lens of this embodiment is 1, indicating that there is no vignetting in the entire field of view of the microscope tube lens and the imaging brightness is uniform.

[0043] Figure 5 This is a field curvature distortion diagram of a microscope tube lens according to an embodiment of the present utility model. Figure 5 The left side of the figure is the field curvature diagram, the vertical axis is the field of view in the direction of incident light of the tube lens, and the horizontal axis is the field curvature value, the unit is mm. Figure 5 The figure on the right is the distortion diagram, the vertical axis is the image field during imaging, and the horizontal axis is the distortion amount (%). When testing the field curvature diagram, the data obtained are as follows: the maximum field of view is 4mm, the sagittal field curvature is 0.0274mm, and the meridional field curvature is 0.0461mm. When testing the distortion diagram, the data obtained are as follows: the maximum field of view is 4.000mm, and the maximum distortion amount is 0.6885%. Figure 5 As shown, the field curvature values ​​for both the meridian and sagittal planes at each wavelength are below 0.06mm, ensuring clear imaging across the entire field of view without introducing additional field curvature. Distortion across the entire field of view at each wavelength is within 0.8%, demonstrating good distortion correction and excellent wide-field imaging performance.

[0044] This embodiment also provides a microscope comprising the microscope tube lens of any of the aforementioned embodiments. In one specific embodiment, by adjusting the specific parameters and structures of each lens, the microscope tube lens has an image field of view of 40.272 mm and a focal length of 200 mm. This improves imaging quality while also providing a higher image field than conventional tube lenses, meeting the large-field measurement requirements of semiconductor measurement equipment and enhancing the overall performance of the microscope. The microscope tube lens has excellent aberration correction and is free of vignetting. It is also a fully independently designed device, resolving the issue of existing tube lenses being poorly compatible with semiconductor measurement equipment.

[0045] Those skilled in the art should understand that, unless otherwise specified, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", "clockwise", "counterclockwise", etc. in the embodiments of the present invention used to indicate orientation or positional relationships are merely for the convenience of describing and understanding the technical solutions of the present invention, and do not indicate or imply that the device or component referred to must have a specific orientation, and therefore should not be understood as a limitation to the present invention.

[0046] The terms "first", "second", etc. are used only for descriptive purposes and do not connote or imply relative importance or an ordered or prioritized order to the indicated technical features. Thus, the use of "first", "second", etc. to describe a particular feature can mean one or more of the features being so described and can be used either explicitly or implicitly in this specification. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined. When a certain feature is "included", "comprises" or "comprised of" a certain component, unless otherwise specifically described, it means that the feature can include the component and can further include other components, unless otherwise specifically described.

[0047] Unless otherwise defined, the terms "mounting", "connected", "connecting", "fixed", and the like, are to be construed as broad terms, for example, can be fixed connection, can be detachable connection, or integral; can be mechanical connection, can be electrical connection; can be direct connection, can be indirect connection through an intermediate medium, can be internal connection of two elements or interaction relationship between two elements, unless otherwise specifically defined. Those skilled in the art should be able to understand the specific meaning of the above terms in the present application according to the specific circumstances.

[0048] In addition, in the description of the present embodiment, the first feature "above" or "below" the second feature can include that the first and second features are in direct contact, or can include that the first and second features are not in direct contact but are in contact through another feature between them. That is, in the description of the present embodiment, the first feature "above", "over", and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher in horizontal height than the second feature. The first feature "below", "under", or "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the first feature is lower in horizontal height than the second feature.

[0049] In the description of the present embodiment, the description of the terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0050] Up to now, the person skilled in the art should recognize that, although the multiple exemplary embodiments of the utility model have been shown and described in detail herein, many other variants or modifications conforming to the principles of the utility model can still be directly determined or deduced according to the content disclosed by the utility model without departing from the spirit and scope of the utility model. Therefore, the scope of the utility model should be understood and recognized as covering all these other variants or modifications.

Claims

1. A microscope tube lens, characterized in that: include: a first lens group, a second lens group, and a third lens group arranged in sequence from the object side to the image side on the same optical axis; The first lens group, the second lens group, and the third lens group each include at least two lenses, and at least two lenses in each lens group have different refractive indices; The first lens group has a convex surface facing the object side and a concave surface facing the image side; the second lens group has a concave surface facing the object side and a convex surface facing the image side; the third lens group has a concave surface facing the object side and a convex surface facing the image side.

2. The microscope tube lens according to claim 1, characterized in that: 0.55<fG1 / f<0.75, 0.85<fG2 / f<1.05, -0.45<fG3 / f<-0.25, where fG1 is the focal length of the first lens group, fG2 is the focal length of the second lens group, fG3 is the focal length of the third lens group, and f is the focal length of the microscope tube lens.

3. The microscope tube lens according to claim 2, characterized in that: The first lens group is a doublet lens with positive optical power, including a first lens and a second lens starting from the object side; the first lens has a convex surface facing the object side and a convex surface facing the image side; the second lens has a concave surface facing the object side and a concave surface facing the image side; The second lens group is a doublet lens with positive refractive power, including a third lens and a fourth lens starting from the object side; the third lens has a concave surface facing the object side and a convex surface facing the image side; the fourth lens has a concave surface facing the object side and a convex surface facing the image side; The third lens group is a doublet lens with negative optical power, including a fifth lens and a sixth lens starting from the object side; the fifth lens has a concave surface facing the object side and a convex surface facing the image side; the sixth lens has a concave surface facing the object side and a convex surface facing the image side.

4. The microscope tube lens according to claim 3, characterized in that: The first lens and the fifth lens both satisfy the following conditions: 1.50<nd<1.60, 58<Vd<72; the second lens, the third lens, and the fourth lens all satisfy the following conditions: 1.60<nd<1.78, 25<Vd<62; and the sixth lens satisfies the following conditions: 1.92<nd<1.96, 27<Vd<35, where nd is the refractive index at a wavelength of 587.6 nm, and Vd is the Abbe number at a wavelength of 587.6 nm.

5. The microscope tube lens according to claim 4, characterized in that: The refractive index of the first lens is 1.55 and the Abbe number is 70; The refractive index of the second lens is 1.68 and the Abbe number is 33; The refractive index of the third lens is 1.74 and the Abbe number is 28; The fourth lens has an emissivity of 1.6 and an Abbe number of 61; The refractive index of the fifth lens is 1.56 and the Abbe number is 58; The refractive index of the sixth lens is 1.92, and the Abbe number is 31.

6. The microscope tube lens according to claim 5, characterized in that: The surface of the first lens facing the object side is the first mirror surface, the cemented surface of the first lens and the second lens is the second mirror surface, and the surface of the second lens facing the image side is the third mirror surface. The surface of the third lens facing the object side is the fourth mirror surface, the cemented surface of the third lens and the fourth lens is the fifth mirror surface, and the surface of the fourth lens facing the image side is the sixth mirror surface. The surface of the fifth lens facing the object side is the seventh mirror surface, the cemented surface of the fifth lens and the sixth lens is the eighth mirror surface, and the surface of the sixth lens facing the image side is the ninth mirror surface. The curvature radii of the first mirror surface and the third mirror surface are positive numbers; the curvature radii of the second mirror surface, the fourth mirror surface, the fifth mirror surface, the sixth mirror surface, the seventh mirror surface, the eighth mirror surface, and the ninth mirror surface are negative numbers.

7. The microscope tube lens according to claim 6, characterized in that: The curvature radius of the first mirror surface is 55 mm, and the mirror distance between the first mirror surface and the second mirror surface is 12 mm; The curvature radius of the second mirror surface is -68 mm, and the mirror distance between the second mirror surface and the third mirror surface is 11 mm; The curvature radius of the third mirror surface is 885 mm, and the mirror distance between the third mirror surface and the fourth mirror surface is 30 mm; The curvature radius of the fourth mirror surface is -1840 mm, and the mirror distance between the fourth mirror surface and the fifth mirror surface is 9 mm; The curvature radius of the fifth mirror surface is -50 mm, and the mirror distance between the fifth mirror surface and the sixth mirror surface is 9 mm; The curvature radius of the sixth mirror surface is -240 mm, and the mirror distance between the sixth mirror surface and the seventh mirror surface is 20 mm; The curvature radius of the seventh mirror surface is -45 mm, and the mirror distance between the seventh mirror surface and the eighth mirror surface is 7.5 mm; The curvature radius of the eighth mirror surface is -28 mm, and the mirror distance between the eighth mirror surface and the ninth mirror surface is 5.5 mm; The curvature radius of the ninth mirror surface is -90 mm, and the mirror distance between the ninth mirror surface and the image plane is 65 mm.

8. A microscope comprising the microscope tube lens according to any one of claims 1 to 7.

Images