Microscope objective lens and microscope

Abstract

The invention provides a microscope objective lens and a microscope. The microscope objective lens comprises a first lens, a second lens, a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group, a sixth lens group and a seventh lens group which are sequentially arranged on the same optical axis from an object side to an image side. According to the scheme, specific parameters and structures of all the lenses are set, so that the amplification factor of the objective lens of the microscope is-50x, the field of view diameter of the object space is 0.57 mm, and under the condition that a 200 mm focal length tube lens is used, the field of view diameter of the image space is 28.5 mm, the working distance is 10 mm, and the corresponding numerical aperture is 0.55; the imaging quality and the image space view field are improved, and the problem that an existing 50-time objective lens cannot be well matched with semiconductor measurement equipment can be solved through autonomous design; apochromatic aberration of a visible light wave band can be achieved, spherical aberration, coma aberration, astigmatism, field curvature, distortion, axial chromatic aberration and vertical axis chromatic aberration are corrected, and the requirements of a flat-field apochromatic objective lens are met.

Description

Technical Field

[0001] The present invention relates to the field of microscopes, and in particular to a microscope objective lens and a microscope. Background Art

[0002] Under the condition of rapid development of micro-nano processing technology, the characteristic size of integrated circuits is getting smaller and smaller. In order to adapt to the gradually increasing integration requirements of semiconductor measurement equipment, it is very necessary to use microscope objectives designed for specific needs. At present, some foreign manufacturers can provide conventional 50x microscope objectives, which can be observed under the matching optical system. However, these foreign manufacturers will not provide high-order optical parameters of 50x microscope objectives, which makes it impossible to design microscope objectives in semiconductor measurement equipment, affecting the integration of the system and even reducing the imaging quality of the optical system. Summary of the invention

[0003] One purpose of the present invention is to effectively improve the imaging quality and image field of a microscope objective lens, and to realize the independent design of the microscope objective lens, so that the microscope objective lens can better match the semiconductor measurement equipment.

[0004] A further object of the present invention is to achieve apochromatism in the visible light band, correct spherical aberration, coma, astigmatism, field curvature, distortion, axial chromatic aberration and vertical chromatic aberration, and meet the requirements of plan-field apochromatism objective.

[0005] In particular, the present invention provides a microscope objective lens, comprising: a first lens, a second lens, a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group, a sixth lens group and a seventh lens group, which are sequentially arranged on the same optical axis from the object side to the image side; the first lens has a concave 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 convex surface facing the image side; the first lens group, the second lens group, the third lens group, the fourth lens group, the fifth lens group, the sixth lens group and the seventh lens group respectively include At least two lenses, at least two lenses in each lens group have different refractive indices; the first lens group has a concave surface facing the object side and a convex surface facing the image side; the second lens group has a convex 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; the fourth lens group has a convex surface facing the object side and a convex surface facing the image side; the fifth lens group has a concave surface facing the object side and a convex surface facing the image side; the sixth lens group has a convex surface facing the object side and a concave surface facing the image side; the seventh lens group has a concave surface facing the object side and a concave surface facing the image side.

[0006] Optionally, 12.5<fL1 / f<14.5, 8<fL2 / f<10, 15.5<fG1 / f<17.5, 20<fG2 / f<22, 240<fG3 / f<242, 75<fG4 / f<77, 1600.5<fG5 / f<1602.5, 1172.5<fG6 / f<1174.5, -4.5<fG7 / f<-2.5, wherein fL1 is the focal length of the first lens, fL2 is the focal length of the second lens, 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, fG4 is the focal length of the fourth lens group, fG5 is the focal length of the fifth lens group, fG6 is the focal length of the sixth lens group, fG7 is the focal length of the seventh lens group, and f is the focal length of the microscope objective.

[0007] Optionally, the first lens and the second lens are both positive meniscus lenses with positive optical power; the first lens group is a double-cemented lens with positive optical power, including a third lens and a fourth lens starting from the object side; the third lens is concave facing the object side and is concave facing the image side; the fourth lens is convex facing the object side and is convex facing the image side; the second lens group is a double-cemented lens with positive optical power, including a fifth lens and a sixth lens starting from the object side; the fifth lens is convex facing the object side and is convex facing the image side; the sixth lens is concave facing the object side and is convex facing the image side; the third lens group is a double-cemented lens with positive optical power, including a seventh lens and an eighth lens starting from the object side; the seventh lens is concave facing the object side and is concave facing the image side; the eighth lens is convex facing the object side and is convex facing the image side; the fourth lens group is a double-cemented lens with positive optical power, including a ninth lens starting from the object side. The fifth lens group is a double-cemented lens with positive focal power, including the eleventh lens and the twelfth lens starting from the object side; the eleventh lens is concave facing the object side and is convex facing the image side; the twelfth lens is concave facing the object side and is convex facing the image side; the sixth lens group is a double-cemented lens with positive focal power, including the thirteenth lens and the fourteenth lens starting from the object side; the thirteenth lens is convex facing the object side and is concave facing the image side; the fourteenth lens is convex facing the object side and is concave facing the image side; the seventh lens group is a double-cemented lens with negative focal power, including the fifteenth lens and the sixteenth lens starting from the object side; the fifteenth lens is concave facing the object side and is concave facing the image side; the sixteenth lens is convex facing the object side and is concave facing the image side.

[0008] Optionally, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the eighth lens, the tenth lens, the thirteenth lens, the fourteenth lens, the fifteenth lens, and the sixteenth lens all satisfy the following conditions: 1.56<nd<1.65, 35<Vd<82, where nd is the refractive index at a wavelength of 587.6nm, and Vd is the Abbe number at a wavelength of 587.6nm; the seventh lens, the ninth lens, the eleventh lens, and the twelfth lens all satisfy the following conditions: 1.73<nd<1.96, 17<Vd<32, where nd is the refractive index at a wavelength of 587.6nm, and Vd is the Abbe number at a wavelength of 587.6nm.

[0009] Optionally, the refractive index of the first lens is 1.6, and the Abbe number is 61; the refractive index of the second lens is 1.62, and the Abbe number is 67; the refractive index of the third lens is 1.63, and the Abbe number is 36; the refractive index of the fourth lens is 1.56, and the Abbe number is 71; the refractive index of the fifth lens is 1.55, and the Abbe number is 70; the refractive index of the sixth lens is 1.66, and the Abbe number is 35; the refractive index of the seventh lens is 1.83, and the Abbe number is 26; the refractive index of the eighth lens is 1.55, and the Abbe number is 70; The refractive index of the ninth lens is 1.76 and the Abbe number is 29; the refractive index of the tenth lens is 1.51 and the Abbe number is 80; the refractive index of the eleventh lens is 1.94 and the Abbe number is 19; the refractive index of the twelfth lens is 1.92 and the Abbe number is 32; the refractive index of the thirteenth lens is 1.55 and the Abbe number is 51; the refractive index of the fourteenth lens is 1.60 and the Abbe number is 38; the refractive index of the fifteenth lens is 1.55 and the Abbe number is 38; the refractive index of the sixteenth lens is 1.56 and the Abbe number is 52.

[0010] Optionally, the surface of the first lens facing the object side is a first mirror surface, the surface of the first lens facing the image side is a second mirror surface, the surface of the second lens facing the object side is a third mirror surface, the surface of the second lens facing the image side is a fourth mirror surface, the surface of the third lens facing the object side is a fifth mirror surface, the cemented surface of the third lens and the fourth lens is a sixth mirror surface, the surface of the fourth lens facing the image side is a seventh mirror surface, the surface of the fifth lens facing the object side is an eighth mirror surface, the cemented surface of the fifth lens and the sixth lens is a ninth mirror surface, the surface of the sixth lens facing the image side is a tenth mirror surface, the surface of the seventh lens facing the object side is an eleventh mirror surface, the cemented surface of the seventh lens and the eighth lens is a twelfth mirror surface, the surface of the eighth lens facing the image side is a thirteenth mirror surface, the surface of the ninth lens facing the object side is a fourteenth mirror surface, the cemented surface of the ninth lens and the tenth lens is a fifteenth mirror surface, the surface of the tenth lens facing the image side is a sixteenth mirror surface, the surface of the eleventh lens facing the object side is a seventeenth mirror surface, and the cemented surface of the eleventh lens and the twelfth lens is a The combined surface is the eighteenth mirror surface, the surface of the twelfth lens facing the image side is the nineteenth mirror surface, the surface of the thirteenth lens facing the object side is the twentieth mirror surface, the cemented surface of the thirteenth lens and the fourteenth lens is the twenty-first mirror surface, the surface of the fourteenth lens facing the image side is the twenty-second mirror surface, the surface of the fifteenth lens facing the object side is the twenty-third mirror surface, the cemented surface of the fifteenth lens and the sixteenth lens is the twenty-fourth mirror surface, and the surface of the sixteenth lens facing the image side is the twenty-fifth mirror surface, the curvature radii of the first mirror surface, the second mirror surface, the third mirror surface, the fourth mirror surface, the fifth mirror surface, the seventh mirror surface, the ninth mirror surface, the tenth mirror surface, the eleventh mirror surface, the thirteenth mirror surface, the sixteenth mirror surface, the seventeenth mirror surface, the eighteenth mirror surface, the nineteenth mirror surface and the twenty-third mirror surface are negative numbers; the curvature radii of the sixth mirror surface, the eighth mirror surface, the twelfth mirror surface, the fourteenth mirror surface, the fifteenth mirror surface, the twentieth mirror surface, the twenty-first mirror surface, the twenty-second mirror surface, the twenty-fourth mirror surface and the twenty-fifth mirror surface are positive numbers.

[0011] Optionally, the radius of curvature of the first mirror surface is -14mm, and the mirror distance between the first mirror surface and the second mirror surface is 2.6mm; the radius of curvature of the second mirror surface is -11mm, and the mirror distance between the second mirror surface and the third mirror surface is 0.2mm; the radius of curvature of the third mirror surface is -53mm, and the mirror distance between the third mirror surface and the fourth mirror surface is 3.6mm; the radius of curvature of the fourth mirror surface is -16mm, and the mirror distance between the fourth mirror surface and the fifth mirror surface is 0.8mm; the radius of curvature of the fifth mirror surface is -75mm, and the mirror distance between the fifth mirror surface and the sixth mirror surface is 1.2mm; the radius of curvature of the sixth mirror surface is 32mm, and the mirror distance between the sixth mirror surface and the seventh mirror surface is 5.3mm; the radius of curvature of the seventh mirror surface is -16mm, and the mirror distance between the fourth mirror surface and the fifth mirror surface is 0.8mm; The curvature radius of the 11th mirror is -3200mm, and the mirror distance between the 11th and 12th mirrors is 1.2mm; the curvature radius of the 12th mirror is 24mm, and the mirror distance between the 12th and 13th mirrors is 5.3mm; the curvature radius of the 13th mirror is -51 The mirror distance between the 13th and 14th mirrors is 5.3mm; the curvature radius of the 14th mirror is 58mm, and the mirror distance between the 14th and 15th mirrors is 2.6mm; the curvature radius of the 15th mirror is 17mm, and the mirror distance between the 15th and 16th mirrors is 0.2mm; the curvature radius of the 16th mirror is -96mm, and the mirror distance between the 16th and 17th mirrors is 3.6mm; the curvature radius of the 17th mirror is -107mm, and the mirror distance between the 17th and 18th mirrors is 0.8mm; the curvature radius of the 18th mirror is -14mm, and the mirror distance between the 18th and 19th mirrors is 1.2mm; the curvature radius of the 19th mirror is -14mm, and the mirror distance between the 18th and 19th mirrors is 1.2mm; the curvature radius of the 19th mirror is -14mm, and the mirror distance between the 18th and 19th mirrors is 1.2mm; the curvature radius of the 19th mirror is -14mm, and the mirror distance between the 18th and 19th mirrors is 1.2mm. The diameter of the mirror is -157mm, the mirror distance between the 19th mirror surface and the 20th mirror surface is 5.3mm; the radius of curvature of the 20th mirror surface is 27mm, and the mirror distance between the 20th mirror surface and the 21st mirror surface is 0.2mm; the radius of curvature of the 21st mirror surface is 7mm, and the mirror distance between the 21st mirror surface and the 22nd mirror surface is 3.6mm; the radius of curvature of the 22nd mirror surface is 14mm, and the mirror distance between the 22nd mirror surface and the 23rd mirror surface is 0.8mm; the radius of curvature of the 23rd mirror surface is -34mm, and the mirror distance between the 23rd mirror surface and the 24th mirror surface is 1.2mm; the radius of curvature of the 24th mirror surface is 5mm, and the mirror distance between the 24th mirror surface and the 25th mirror surface is 5.3mm; the radius of curvature of the twenty-fifth mirror surface is 10mm. .

[0012] Optionally, the microscope objective can be used with a tube lens having a focal length of 200 mm.

[0013] Optionally, the microscope objective further includes: an aperture stop, which is arranged on a side of the fifth lens group facing the image side.

[0014] According to another aspect of the present invention, there is also provided a microscope comprising any one of the above-mentioned microscope objective lenses.

[0015] The microscope objective lens of the present invention sets specific parameters and structures of each lens so that the magnification of the microscope objective lens is -50x, and has a field of view higher than that of a conventional commercial 50x microscope objective lens. The diameter of the object side field of view is 0.57mm. When a 200mm focal length tube lens is used, the diameter of the image side field of view is 28.5mm, the working distance is 10mm, and the corresponding numerical aperture NA is relatively large, which is 0.55. While improving the imaging quality, the microscope objective lens has an image side field of view higher than that of a conventional objective lens, and completely realizes independent design, thereby solving the problem that the existing 50x objective lens cannot be well matched with semiconductor measurement equipment.

[0016] Furthermore, the microscope objective lens of the present invention can achieve apochromatism in the visible light band of 486nm-656nm, and well corrects spherical aberration, coma, astigmatism, field curvature, distortion, axial chromatic aberration and vertical chromatic aberration, meeting the requirements of a plan-field apochromatism objective lens.

[0017] Based on the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more aware of the above and other objects, advantages and features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

[0019] Figure 1 is a schematic structural diagram of a microscope objective lens according to an embodiment of the present invention;

[0020] Figure 2 is a full-field full-wavelength spot diagram of a microscope objective according to an embodiment of the present invention;

[0021] Figure 3 is a lateral aberration diagram of a microscope objective according to an embodiment of the present invention;

[0022] Figure 4is a graph of a full-field transfer function of a microscope objective according to an embodiment of the present invention;

[0023] Figure 5 is an axial aberration diagram of a microscope objective lens according to an embodiment of the present invention when the pupil radius is 2.2000 mm;

[0024] Figure 6 is a vertical axis chromatic aberration diagram of a microscope objective lens when the maximum field of view is 0.2850 mm according to an embodiment of the present invention; and

[0025] Figure 7 is a field curvature distortion diagram of a microscope objective according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] This embodiment provides a microscope objective lens, which can effectively improve the imaging quality and image field of the microscope objective lens, thereby improving the overall performance of the microscope. Figure 1 Schematic diagram of the structure of a microscope objective lens according to an embodiment of the present invention. Figure 1 As shown, the microscope objective of this embodiment includes: a first lens L1, a second lens L2, a first lens group G1, a second lens group G2, a third lens group G3, a fourth lens group G4, a fifth lens group G5, a sixth lens group G6 and a seventh lens group G7, which are arranged in sequence from the object side to the image side on the same optical axis.

[0027] The first lens L1 is concave facing the object side and convex facing the image side; the second lens L2 is concave facing the object side and convex facing the image side. The first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, the sixth lens group G6 and the seventh lens group G7 each include at least two lenses, and the refractive index of at least two lenses in each lens group is different.

[0028] The first lens group G1 has a concave surface facing the object side and a convex surface facing the image side; the second lens group G2 has a convex surface facing the object side and a convex surface facing the image side; the third lens group G3 has a concave surface facing the object side and a convex surface facing the image side; the fourth lens group G4 has a convex surface facing the object side and a convex surface facing the image side; the fifth lens group G5 has a concave surface facing the object side and a convex surface facing the image side; the sixth lens group G6 has a convex surface facing the object side and a concave surface facing the image side; the seventh lens group G7 has a concave surface facing the object side and a concave surface facing the image side.

[0029] In a specific embodiment, 12.5<fL1 / f<14.5, 8<fL2 / f<10, 15.5<fG1 / f<17.5, 20<fG2 / f<22, 240<fG3 / f<242, 75<fG4 / f<77, 1600.5<fG5 / f<1602.5, 1172.5<fG6 / f<1174.5, -4.5<fG7 / f<-2.5 , where fL1 is the focal length of the first lens L1, fL2 is the focal length of the second lens L2, 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, fG4 is the focal length of the fourth lens group G4, fG5 is the focal length of the fifth lens group G5, fG6 is the focal length of the sixth lens group G6, fG7 is the focal length of the seventh lens group G7, and f is the focal length of the microscope objective.

[0030] In a preferred embodiment, the first lens L1 and the second lens L2 are both positive meniscus lenses with positive optical power. Among them, the positive meniscus lens refers to a lens composed of two curved surfaces with similar curvature radii, which has a positive focal length. The positive meniscus lens can usually be used to reduce the focal length of another lens and increase the numerical aperture. When expanding, shrinking or diverging collimated light, the light beam can be incident on the convex surface of the positive meniscus lens, thereby reducing spherical aberration. When used for converging light collimation, the light beam can be incident on the concave surface of the positive meniscus lens. In addition, positive optical power refers to the optical power of the optical system that converges light, and its value is greater than zero. An optical system with positive optical power will converge light, that is, the light beam will become more concentrated after passing through the system. In other words, the first lens L1 and the second lens L2 in this embodiment can both converge light.

[0031] The first lens group G1 is a doublet lens with positive focal power, including the third lens L3 and the fourth lens L4 starting from the object side; the third lens L3 is concave facing the object side and the image side; the fourth lens L4 is convex facing the object side and the image side. Among them, the doublet lens refers to a combined lens formed by two lenses glued together, and a better imaging effect is achieved by combining the two lenses. Compared with a single lens, the doublet lens can achieve a shorter focal length, a larger magnification, better imaging quality, and a higher axial resolution.

[0032] The second lens group G2 is a doublet lens with positive power, including the fifth lens L5 and the sixth lens L6 starting from the object side; the fifth lens L5 has a convex surface facing the object side and a convex surface facing the image side; the sixth lens L6 has a concave surface facing the object side and a convex surface facing the image side. The third lens group G3 is a doublet lens with positive power, including the seventh lens L7 and the eighth lens L8 starting from the object side; the seventh lens L7 has a concave surface facing the object side and a concave surface facing the image side; the eighth lens L8 has a convex surface facing the object side and a convex surface facing the image side. The fourth lens group G4 is a doublet lens with positive power, including the ninth lens L9 and the tenth lens L10 starting from the object side; the ninth lens L9 has a convex surface facing the object side and a concave surface facing the image side; the tenth lens L10 has a convex surface facing the object side and a convex surface facing the image side.

[0033] The fifth lens group G5 is a doublet lens with positive refractive power, including the eleventh lens L11 and the twelfth lens L12 from the object side; the eleventh lens L11 is concave facing the object side and is convex facing the image side; the twelfth lens L12 is concave facing the object side and is convex facing the image side. The sixth lens group G6 is a doublet lens with positive refractive power, including the thirteenth lens L13 and the fourteenth lens L14 from the object side; the thirteenth lens L13 is convex facing the object side and is concave facing the image side; the fourteenth lens L14 is convex facing the object side and is concave facing the image side.

[0034] The seventh lens group G7 is a double cemented lens with negative power, including the fifteenth lens L15 and the sixteenth lens L16 starting from the object side; the fifteenth lens L15 is concave facing the object side and the image side; the sixteenth lens L16 is convex facing the object side and the image side. Among them, the optical system with negative power will make the light more divergent, that is, the light beam will become more dispersed after passing through the system. In other words, the seventh lens group G7 in this embodiment can make the light more divergent.

[0035] In a specific embodiment, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the eighth lens L8, the tenth lens L10, the thirteenth lens L13, the fourteenth lens L14, the fifteenth lens L15, and the sixteenth lens L16 all satisfy the following conditions: 1.56<nd<1.65, 35<Vd<82, 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.

[0036] The seventh lens L7, the ninth lens L9, the eleventh lens L11 and the twelfth lens L12 all satisfy the following conditions: 1.73<nd<1.96, 17<Vd<32, where nd is the refractive index at a wavelength of 587.6nm, and Vd is the Abbe number at a wavelength of 587.6nm.

[0037] In a preferred embodiment, the specific values ​​of the refractive index and Abbe number of the first lens L1 to the sixteenth lens L16 can refer to Table 1. As shown in Table 1, the refractive index of the first lens L1 is 1.6, and the Abbe number is 61; the refractive index of the second lens L2 is 1.62, and the Abbe number is 67; the refractive index of the third lens L3 is 1.63, and the Abbe number is 36; the refractive index of the fourth lens L4 is 1.56, and the Abbe number is 71; the refractive index of the fifth lens L5 is 1.55, and the Abbe number is 70; the refractive index of the sixth lens L6 is 1.66, and the Abbe number is 35; the refractive index of the seventh lens L7 is 1.83, and the Abbe number is 26; the refractive index of the eighth lens L8 is 1.55, and the Abbe number is 70; the ninth lens The refractive index of L9 is 1.76, and the Abbe number is 29; the refractive index of the tenth lens L10 is 1.51, and the Abbe number is 80; the refractive index of the eleventh lens L11 is 1.94, and the Abbe number is 19; the refractive index of the twelfth lens L12 is 1.92, and the Abbe number is 32; the refractive index of the thirteenth lens L13 is 1.55, and the Abbe number is 51; the refractive index of the fourteenth lens L14 is 1.60, and the Abbe number is 38; the refractive index of the fifteenth lens L15 is 1.55, and the Abbe number is 38; the refractive index of the sixteenth lens L16 is 1.56, and the Abbe number is 52.

[0038] Table 1

[0039]

[0040]

[0041] In a specific embodiment, the surface of the first lens L1 facing the object side is a first mirror surface S1, the surface of the first lens L1 facing the image side is a second mirror surface S2, the surface of the second lens L2 facing the object side is a third mirror surface S3, the surface of the second lens L2 facing the image side is a fourth mirror surface S4, the surface of the third lens L3 facing the object side is a fifth mirror surface S5, the cemented surface of the third lens L3 and the fourth lens L4 is a sixth mirror surface S6, the surface of the fourth lens L4 facing the image side is a seventh mirror surface S7, the surface of the fifth lens L5 facing the object side is an eighth mirror surface S8, the cemented surface of the fifth lens L5 and the sixth lens L6 is a ninth mirror surface S9, the surface of the sixth lens L6 facing the image side is a tenth mirror surface S10, the surface of the seventh lens L7 facing the object side is an eleventh mirror surface S11, the cemented surface of the seventh lens L7 and the eighth lens L8 is a twelfth mirror surface S12, and the surface of the eighth lens L8 facing the image side is a thirteenth mirror surface S13.

[0042] The surface of the ninth lens L9 facing the object side is the fourteenth mirror surface S14, the cemented surface of the ninth lens L9 and the tenth lens L10 is the fifteenth mirror surface S15, the surface of the tenth lens L10 facing the image side is the sixteenth mirror surface S16, the surface of the eleventh lens L11 facing the object side is the seventeenth mirror surface S17, the cemented surface of the eleventh lens L11 and the twelfth lens L12 is the eighteenth mirror surface S18, the surface of the twelfth lens L12 facing the image side is the nineteenth mirror surface S19, the thirteenth lens L10 facing the image side is the sixteenth mirror surface S16, The surface of L13 facing the object side is the twentieth mirror surface S20, the cemented surface of the thirteenth lens L13 and the fourteenth lens L14 is the twenty-first mirror surface S21, the surface of the fourteenth lens L14 facing the image side is the twenty-second mirror surface S22, the surface of the fifteenth lens L15 facing the object side is the twenty-third mirror surface S23, the cemented surface of the fifteenth lens L15 and the sixteenth lens L16 is the twenty-fourth mirror surface S24, and the surface of the sixteenth lens L16 facing the image side is the twenty-fifth mirror surface S25.

[0043] In a preferred embodiment, the specific values ​​of the curvature radii of the first mirror surface S1 to the twenty-fifth mirror surface S25 and the mirror surface distance between two adjacent mirror surfaces can be referred to Table 2. As shown in Table 2, the radius of curvature of the first mirror surface S1 is -14 mm, and the mirror distance between the first mirror surface S1 and the second mirror surface S2 is 2.6 mm; the radius of curvature of the second mirror surface S2 is -11 mm, and the mirror distance between the second mirror surface S2 and the third mirror surface S3 is 0.2 mm; the radius of curvature of the third mirror surface S3 is -53 mm, and the mirror distance between the third mirror surface S3 and the fourth mirror surface S4 is 3.6 mm; the radius of curvature of the fourth mirror surface S4 is -16 mm, and the mirror distance between the fourth mirror surface S4 and the fifth mirror surface S5 is 0.8 mm; the radius of curvature of the fifth mirror surface S5 is -75 mm, and the mirror distance between the fifth mirror surface S5 and the sixth mirror surface S6 is 1.2 mm; the radius of curvature of the sixth mirror surface S6 is 32 mm, and the mirror distance between the sixth mirror surface S6 and the seventh mirror surface S7 is 5.3 mm; the seventh mirror surface S7 The radius of curvature of the mirror surface S7 is -23mm, and the mirror distance between the seventh mirror surface S7 and the eighth mirror surface S8 is 2.6mm; the radius of curvature of the eighth mirror surface S8 is 95mm, and the mirror distance between the eighth mirror surface S8 and the ninth mirror surface S9 is 0.2mm; the radius of curvature of the ninth mirror surface S9 is -20mm, and the mirror distance between the ninth mirror surface S9 and the tenth mirror surface S10 is 3.6mm; the radius of curvature of the tenth mirror surface S10 is -35mm, and the mirror distance between the tenth mirror surface S10 and the eleventh mirror surface S11 is 0.8mm; the radius of curvature of the eleventh mirror surface S11 is -3200mm, and the mirror distance between the eleventh mirror surface S11 and the twelfth mirror surface S12 is 1.2mm; the radius of curvature of the twelfth mirror surface S12 is 24mm, and the mirror distance between the twelfth mirror surface S12 and the thirteenth mirror surface S13 is 5.3mm.

[0044] The curvature radius of the thirteenth mirror surface S13 is -51 mm, and the mirror distance between the thirteenth mirror surface S13 and the fourteenth mirror surface S14 is 5.3 mm; the curvature radius of the fourteenth mirror surface S14 is 58 mm, and the mirror distance between the fourteenth mirror surface S14 and the fifteenth mirror surface S15 is 2.6 mm; the curvature radius of the fifteenth mirror surface S15 is 17 mm, and the mirror distance between the fifteenth mirror surface S15 and the sixteenth mirror surface S16 is 0.2 mm; the sixteenth mirror surface S16 The curvature radius of the sixteenth mirror surface S16 is -96mm, and the mirror distance between the sixteenth mirror surface S16 and the seventeenth mirror surface S17 is 3.6mm; the curvature radius of the seventeenth mirror surface S17 is -107mm, and the mirror distance between the seventeenth mirror surface S17 and the eighteenth mirror surface S18 is 0.8mm; the curvature radius of the eighteenth mirror surface S18 is -14mm, and the mirror distance between the eighteenth mirror surface S18 and the nineteenth mirror surface S19 is 1.2mm; the curvature radius of the nineteenth mirror surface S19 is -157mm, the mirror distance between the nineteenth mirror surface S19 and the twentieth mirror surface S20 is 5.3mm; the curvature radius of the twentieth mirror surface S20 is 27mm, the mirror distance between the twentieth mirror surface S20 and the twenty-first mirror surface S21 is 0.2mm; the curvature radius of the twenty-first mirror surface S21 is 7mm, the mirror distance between the twenty-first mirror surface S21 and the twenty-second mirror surface S22 is 3.6mm; the curvature radius of the twenty-second mirror surface S22 is 14mm The mirror distance between the twenty-second mirror plane S22 and the twenty-third mirror plane S23 is 0.8mm; the curvature radius of the twenty-third mirror plane S23 is -34mm, and the mirror distance between the twenty-third mirror plane S23 and the twenty-fourth mirror plane S24 is 1.2mm; the curvature radius of the twenty-fourth mirror plane S24 is 5mm, and the mirror distance between the twenty-fourth mirror plane S24 and the twenty-fifth mirror plane S25 is 5.3mm; the curvature radius of the twenty-fifth mirror plane S25 is 10mm.

[0045] Table 2

[0046] Mirror Name Curvature radius (mm) Mirror distance(mm) First mirror S1 -14.00 2.60 Second mirror S2 -11.00 0.20 The third mirror S3 -53.00 3.60 Fourth mirror S4 -16.00 0.80 Fifth Mirror S5 -75.00 1.20 Sixth Mirror S6 32.00 5.30 Seventh Mirror S7 -23.00 0.20 The eighth mirror S8 95.00 8.80 Ninth Mirror S9 -20.00 1.20 Tenth Mirror S10 -35.00 5.50 Mirror 11 S11 -3200.00 0.50 Mirror S12 24.00 4.20 Mirror 13 S13 -51.00 1.50 Mirror 14 S14 58.00 3.50 Mirror S15 17.00 3.90 Mirror S16 -96.00 3.40 Mirror S17 -107.00 4.50 Mirror 18 S18 -14.00 1.20 Mirror S19 -157.00 0.30 Mirror S20 27.00 14.50 Mirror S21 7.00 13.10 Mirror S22 14.00 1.20 Mirror S23 -34.00 1.20 Mirror S24 5.00 1.50 Mirror S25 10 unlimited

[0047] By setting the specific parameters and structures of each lens in Table 1 and Table 2, the magnification of the microscope objective lens can be -50x, the image field of view is 28.5mm, the numerical aperture is 0.55, and the focal length of the tube lens that can be used is 200mm. The microscope objective lens of this embodiment improves the imaging quality while enabling the microscope objective lens to have an image field of view higher than that of a conventional objective lens, and completely realizes independent design, solving the problem that the existing 50x objective lens cannot be well matched with semiconductor measurement equipment.

[0048] In a preferred embodiment, the microscope objective lens may further include: an aperture stop AS, which is arranged on the side of the fifth lens group G5 facing the image side. The function of the aperture stop AS is to limit the aperture of the light beam. Since the aperture stop AS is a plane, its radius of curvature is infinite. Moreover, the mirror distance from the aperture stop AS to the twentieth mirror surface S20 may be 4.5 mm. In addition, it should be noted that since the object plane is a plane, its radius of curvature is infinite. Moreover, the mirror distance from the object plane to the first mirror surface S1 may be 10 mm. The mirror distance between the twenty-fifth mirror surface S25 and the image plane is infinite.

[0049] Figure 2 1 is a full-field full-wavelength spot diagram of a microscope objective according to an embodiment of the present invention. Figure 2 The focusing conditions of light with wavelengths ranging from 0.486133μm to 0.656273μm at the focal point under different image plane fields of view are shown. The object plane half field of view of field of view (1) is 0.285mm, the object plane half field of view of field of view (2) is 0.200mm, and the object plane half field of view of field of view (3) is 0.000mm. Since the magnification of the objective lens is -50x, the image plane field of view is the object plane half field of view*2*50. The image plane fields of view corresponding to fields of view (1), (2), and (3) are 28.5mm, 20.0mm, and 0.0mm, respectively. The test data are as follows: the Airy disk radius (diffraction limit) is 0.652μm, the RMS radius (root mean square) when the field of view is (1) is 0.236μm, the GEO radius (maximum) is 0.648μm, the RMS radius when the field of view is (2) is 0.150μm, the GEO radius is 0.353μm, and the RMS radius when the field of view is (3) is 0.057μm, and the GEO radius is 0.161μm.

[0050] The RMS radius is also called the root mean square spot radius. It is an indicator used to describe the size of the light beam. It is obtained by taking the square root of the light intensity distribution after quadratic averaging. The GEO radius (Geometric Optical Radius) represents the radius of the smallest center circle that contains all the light rays. Specifically, the GEO radius is the smallest center circle radius that can satisfy all the light rays falling within its range. Figure 2 It can be seen that the focused spots of light of different wavelengths in different fields of view are all within the range of the Airy disk, indicating that the microscope objective lens of this embodiment has an excellent focusing effect. The point array diagrams are all better than the diffraction limit, which shows that the microscope objective lens of this embodiment has good aberration control and basically reaches the system limit.

[0051] Figure 3 is a lateral aberration diagram of a microscope objective according to an embodiment of the present invention. Figure 3The horizontal coordinates Px and Py in the figure represent the entrance pupil position, the vertical coordinates ex and ey represent the beam distribution (lateral aberration) at the image plane, y represents the meridional direction, and x represents the sagittal direction. Figure 3 The figure shows the lateral aberration of light of different wavelengths at different entrance pupil positions when the image plane field of view is 28.5mm, 20.0mm and 0.0mm. The image plane fields of view corresponding to fields of view (1), (2) and (3) are 28.5mm, 20.0mm and 0.0mm respectively. Figure 3 As shown, when the image field of view is 28.5mm, 20.0mm and 0.0mm, the lateral aberration of light with wavelengths of 0.486, 0.588 and 0.656 at different entrance pupil positions is within ±1μm, indicating that the aberration balance is very good and the imaging is excellent.

[0052] Figure 4 4 is a graph of the full field transfer function of a microscope objective according to an embodiment of the present invention. Figure 4 The vertical axis is the modulus of the normalized transfer function, and the horizontal axis is the spatial frequency, in units of lp / mm. The outermost line is the transfer function curve of the system under the diffraction limit. Figure 4 As shown, for the microscope objective of this embodiment, when the image field of view is 28.5mm, 20.0mm and 0.0mm, the transfer function curves of the meridian plane and the sagittal plane of each wavelength show that the on-axis field of view transfer function curve and the off-axis field of view transfer function curve are close to the diffraction limit, indicating that the imaging contrast of the entire field of view of the optical system is very high and the image layering is clear.

[0053] Figure 5 1 is an axial aberration diagram of a microscope objective lens according to an embodiment of the present invention when the pupil radius is 2.2000 mm. Figure 5 The ordinate is the normalized pupil coordinate, and the abscissa is the axial aberration, in units of mm. Figure 5 The axial aberration diagram of light of different wavelengths when the pupil radius is 2.2000mm is shown. Figure 5 As shown, the axial aberration of each wavelength is less than 0.0003mm, which satisfies the axial aberration of each entrance pupil position of any two wavelengths to reach the apochromatic level. It should be noted that the axial aberration can also be called longitudinal aberration, axial chromatic aberration or longitudinal chromatic aberration.

[0054] Figure 6 It is a vertical axis chromatic aberration diagram of a microscope objective lens according to an embodiment of the present invention when the maximum field of view is 0.2850 mm. Figure 6 The ordinate is the field of view, in mm, and the abscissa is the lateral aberration, in μm. Figure 6 The vertical axis chromatic aberration diagram of light of different wavelengths when the maximum field of view is 0.2850 mm is shown. Here, the maximum field of view 0.2850 mm refers to the half field of view of the object plane. Figure 6 The curve in represents the size of the diffraction-limited Airy disk of the system, such as Figure 6 As shown, the vertical chromatic aberration of light of different wavelengths is kept within the size of the diffraction-limited Airy disk of the system when the maximum field of view is 0.2850 mm, and the vertical chromatic aberration is well controlled.

[0055] Figure 7 is a field curvature distortion diagram of a microscope objective according to an embodiment of the present invention. Figure 7 The left side of the figure is the field curvature diagram, the ordinate is the field of view in the direction of incident light from the objective lens, and the abscissa is the field curvature value in μm. Figure 7 The figure on the right is the distortion diagram, the ordinate is the image field during imaging, and the abscissa is the distortion amount (%). When testing the field curvature diagram, the data obtained are as follows: the maximum field of view is 4.099 degrees, the sagittal field curvature is 0.0002mm, and the meridian field curvature is 0.0000mm. When testing the distortion diagram, the data obtained are as follows: the maximum field of view is 4.099 degrees, and the maximum distortion amount is 0.5711%. Figure 7 As shown, the field curvature values ​​of the meridian and sagittal planes of each wavelength are all below 0.06mm, the full-field imaging is clear, and no additional field curvature is introduced. The full-field distortion of each wavelength is within 0.8%, the distortion correction is good, and it has excellent large-field imaging performance.

[0056] This embodiment also provides a microscope, which includes the microscope objective lens of any of the above embodiments. In a specific embodiment, by setting the specific parameters and structures of each lens, the magnification of the microscope objective lens is -50x, and it has a field of view higher than that of a conventional commercial 50x microscope objective lens. The object side field of view diameter is 0.57mm. When a 200mm focal length tube lens is used, the image side field of view diameter is 28.5mm, the working distance is 10mm, and the corresponding numerical aperture NA is relatively large, which is 0.55. Apochromatism in the visible light band of 486nm-656nm can be achieved, and spherical aberration, coma, astigmatism, field curvature, distortion, axial chromatic aberration and vertical axis chromatic aberration are well corrected, meeting the requirements of plan-field apochromatism objective lens.

[0057] 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 referred device or component must have a specific orientation, and therefore should not be understood as limiting the present invention.

[0058] The terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first", "second", etc. may explicitly or implicitly include at least one of the features, that is, include one or more of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. When a feature "includes or contains" one or some of the features it covers, unless otherwise specifically described, this indicates that other features are not excluded and may further include other features.

[0059] Unless otherwise clearly defined and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. A person skilled in the art should be able to understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0060] In addition, in the description of this embodiment, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. That is, in the description of this embodiment, the first feature being "above", "above", and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature being "below", "below", or "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0061] In the description of the present embodiment, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0062] At this point, those skilled in the art should recognize that, although multiple exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications that conform to the principles of the present invention can still be directly determined or derived based on the content disclosed in the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all these other variations or modifications.

Claims

1. A microscope objective lens, characterized in that: include: A first lens, a second lens, a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group, a sixth lens group and a seventh lens group are sequentially arranged on the same optical axis from the object side to the image side; The first lens has a concave 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 convex surface facing the image side; The first lens group, the second lens group, the third lens group, the fourth lens group, the fifth lens group, the sixth lens group and the seventh lens group respectively include at least two lenses, and the refractive index of at least two lenses in each lens group is different; The first lens group has a concave surface facing the object side and a convex surface facing the image side; The second lens group has a convex 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; the fourth lens group has a convex surface facing the object side and a convex surface facing the image side; The fifth lens group has a concave surface facing the object side and a convex surface facing the image side; the sixth lens group has a convex surface facing the object side and a concave surface facing the image side; the seventh lens group has a concave surface facing the object side and a concave surface facing the image side.

2. The microscope objective lens according to claim 1, characterized in that: 12.5<fL1 / f<14.5, 8<fL2 / f<10, 15.5<fG1 / f<17.5, 20<fG2 / f<22, 240<fG3 / f<242 , 75<fG4 / f<77, 1600.5<fG5 / f<1602.5, 1172.5<fG6 / f<1174.5, -4.5<fG7 / f<-2.5, Wherein fL1 is the focal length of the first lens, fL2 is the focal length of the second lens, 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, fG4 is the focal length of the fourth lens group, fG5 is the focal length of the fifth lens group, fG6 is the focal length of the sixth lens group, fG7 is the focal length of the seventh lens group, and f is the focal length of the microscope objective.

3. The microscope objective lens according to claim 2, characterized in that: The first lens and the second lens are both positive meniscus lenses with positive optical power; The first lens group is a doublet lens with positive 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 concave surface facing the image side; the fourth lens has a convex surface facing the object side and a convex surface facing the image side; The second lens group is a doublet lens with positive power, including a fifth lens and a sixth lens starting from the object side; the fifth lens has a convex 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; The third lens group is a doublet lens with positive power, including a seventh lens and an eighth lens starting from the object side; the seventh lens has a concave surface facing the object side and a concave surface facing the image side; the eighth lens has a convex surface facing the object side and a convex surface facing the image side; The fourth lens group is a doublet lens with positive power, including a ninth lens and a tenth lens starting from the object side; the ninth lens has a convex surface facing the object side and a concave surface facing the image side; the tenth lens has a convex surface facing the object side and a convex surface facing the image side; The fifth lens group is a doublet lens with positive power, including an eleventh lens and a twelfth lens starting from the object side; the eleventh lens has a concave surface facing the object side and a convex surface facing the image side; the twelfth lens has a concave surface facing the object side and a convex surface facing the image side; The sixth lens group is a doublet lens with positive power, including a thirteenth lens and a fourteenth lens starting from the object side; the thirteenth lens has a convex surface facing the object side and a concave surface facing the image side; the fourteenth lens has a convex surface facing the object side and a concave surface facing the image side; The seventh lens group is a doublet lens with negative optical power, including a fifteenth lens and a sixteenth lens starting from the object side; the fifteenth lens has a concave surface facing the object side and a concave surface facing the image side; the sixteenth lens has a convex surface facing the object side and a concave surface facing the image side.

4. The microscope objective lens according to claim 3, characterized in that: The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the eighth lens, the tenth lens, the thirteenth lens, the fourteenth lens, the fifteenth lens, and the sixteenth lens all satisfy the following conditions: 1.56<nd<1.65, 35<Vd<82, wherein nd is a refractive index at a wavelength of 587.6nm, and Vd is an Abbe number at a wavelength of 587.6nm; The seventh lens, the ninth lens, the eleventh lens and the twelfth lens all satisfy the following conditions: 1.73<nd<1.96, 17<Vd<32, wherein nd is the refractive index at a wavelength of 587.6nm, and Vd is the Abbe number at a wavelength of 587.6nm.

5. The microscope objective lens according to claim 4, characterized in that: The refractive index of the first lens is 1.6 and the Abbe number is 61; The refractive index of the second lens is 1.62 and the Abbe number is 67; The refractive index of the third lens is 1.63, and the Abbe number is 36; The fourth lens has an emissivity of 1.56 and an Abbe number of 71; The refractive index of the fifth lens is 1.55 and the Abbe number is 70; The refractive index of the sixth lens is 1.66, and the Abbe number is 35; The refractive index of the seventh lens is 1.83, and the Abbe number is 26; The eighth lens has a reflectivity of 1.55 and an Abbe number of 70; The refractive index of the ninth lens is 1.76 and the Abbe number is 29; The refractive index of the tenth lens is 1.51, and the Abbe number is 80; The refractive index of the eleventh lens is 1.94, and the Abbe number is 19; The reflectivity of the twelfth lens is 1.92 and the Abbe number is 32; The refractive index of the thirteenth lens is 1.55, and the Abbe number is 51; The refractive index of the fourteenth lens is 1.60, and the Abbe number is 38; The refractive index of the fifteenth lens is 1.55, and the Abbe number is 38; The reflectance of the sixteenth lens is 1.56 and the Abbe number is 52.

6. The microscope objective lens according to claim 5, characterized in that: The surface of the first lens facing the object side is a first mirror surface, and the surface of the first lens facing the image side is a second mirror surface. The surface of the second lens facing the object side is the third mirror surface, and the surface of the second lens facing the image side is the fourth mirror surface. The surface of the third lens facing the object side is the fifth mirror surface, the cemented surface of the third lens and the fourth lens is the sixth mirror surface, and the surface of the fourth lens facing the image side is the seventh mirror surface. The surface of the fifth lens facing the object side is the eighth mirror surface, the cemented surface of the fifth lens and the sixth lens is the ninth mirror surface, and the surface of the sixth lens facing the image side is the tenth mirror surface. The surface of the seventh lens facing the object side is the eleventh mirror surface, the cemented surface of the seventh lens and the eighth lens is the twelfth mirror surface, and the surface of the eighth lens facing the image side is the thirteenth mirror surface. The surface of the ninth lens facing the object side is the fourteenth mirror surface, the cemented surface of the ninth lens and the tenth lens is the fifteenth mirror surface, and the surface of the tenth lens facing the image side is the sixteenth mirror surface. The surface of the eleventh lens facing the object side is the seventeenth mirror surface, the cemented surface of the eleventh lens and the twelfth lens is the eighteenth mirror surface, and the surface of the twelfth lens facing the image side is the nineteenth mirror surface. The surface of the thirteenth lens facing the object side is the twentieth mirror surface, the cemented surface of the thirteenth lens and the fourteenth lens is the twenty-first mirror surface, and the surface of the fourteenth lens facing the image side is the twenty-second mirror surface. The surface of the fifteenth lens facing the object side is the twenty-third mirror surface, the cemented surface of the fifteenth lens and the sixteenth lens is the twenty-fourth mirror surface, and the surface of the sixteenth lens facing the image side is the twenty-fifth mirror surface. The curvature radii of the first mirror surface, the second mirror surface, the third mirror surface, the fourth mirror surface, the fifth mirror surface, the seventh mirror surface, the ninth mirror surface, the tenth mirror surface, the eleventh mirror surface, the thirteenth mirror surface, the sixteenth mirror surface, the seventeenth mirror surface, the eighteenth mirror surface, the nineteenth mirror surface, and the twenty-third mirror surface are negative numbers; the curvature radii of the sixth mirror surface, the eighth mirror surface, the twelfth mirror surface, the fourteenth mirror surface, the fifteenth mirror surface, the twentieth mirror surface, the twenty-first mirror surface, the twenty-second mirror surface, the twenty-fourth mirror surface, and the twenty-fifth mirror surface are positive numbers.

7. The microscope objective lens according to claim 6, characterized in that: The curvature radius of the first mirror surface is -14 mm, and the mirror distance between the first mirror surface and the second mirror surface is 2.6 mm; The curvature radius of the second mirror surface is -11 mm, and the mirror distance between the second mirror surface and the third mirror surface is 0.2 mm; The curvature radius of the third mirror surface is -53 mm, and the mirror distance between the third mirror surface and the fourth mirror surface is 3.6 mm; The curvature radius of the fourth mirror surface is -16 mm, and the mirror distance between the fourth mirror surface and the fifth mirror surface is 0.8 mm; The curvature radius of the fifth mirror surface is -75 mm, and the mirror distance between the fifth mirror surface and the sixth mirror surface is 1.2 mm; The curvature radius of the sixth mirror surface is 32 mm, and the mirror distance between the sixth mirror surface and the seventh mirror surface is 5.3 mm; The curvature radius of the seventh mirror surface is -23 mm, and the mirror distance between the seventh mirror surface and the eighth mirror surface is 2.6 mm; The curvature radius of the eighth mirror surface is 95 mm, and the mirror distance between the eighth mirror surface and the ninth mirror surface is 0.2 mm; The curvature radius of the ninth mirror surface is -20 mm, and the mirror distance between the ninth mirror surface and the tenth mirror surface is 3.6 mm; The curvature radius of the tenth mirror surface is -35 mm, and the mirror distance between the tenth mirror surface and the eleventh mirror surface is 0.8 mm; The curvature radius of the eleventh mirror surface is -3200 mm, and the mirror distance between the eleventh mirror surface and the twelfth mirror surface is 1.2 mm; The curvature radius of the twelfth mirror surface is 24 mm, and the mirror distance between the twelfth mirror surface and the thirteenth mirror surface is 5.3 mm; The curvature radius of the thirteenth mirror surface is -51 mm, and the mirror distance between the thirteenth mirror surface and the fourteenth mirror surface is 5.3 mm; The curvature radius of the fourteenth mirror surface is 58 mm, and the mirror distance between the fourteenth mirror surface and the fifteenth mirror surface is 2.6 mm; The curvature radius of the fifteenth mirror surface is 17 mm, and the mirror distance between the fifteenth mirror surface and the sixteenth mirror surface is 0.2 mm; The curvature radius of the sixteenth mirror surface is -96 mm, and the mirror distance between the sixteenth mirror surface and the seventeenth mirror surface is 3.6 mm; The curvature radius of the seventeenth mirror surface is -107 mm, and the mirror distance between the seventeenth mirror surface and the eighteenth mirror surface is 0.8 mm; The curvature radius of the eighteenth mirror surface is -14 mm, and the mirror distance between the eighteenth mirror surface and the nineteenth mirror surface is 1.2 mm; The curvature radius of the nineteenth mirror surface is -157 mm, and the mirror distance between the nineteenth mirror surface and the twentieth mirror surface is 5.3 mm; The curvature radius of the 20th mirror surface is 27 mm, and the mirror distance between the 20th mirror surface and the 21st mirror surface is 0.2 mm; The curvature radius of the twenty-first mirror surface is 7 mm, and the mirror distance between the twenty-first mirror surface and the twenty-second mirror surface is 3.6 mm; The curvature radius of the 22nd mirror surface is 14 mm, and the mirror distance between the 22nd mirror surface and the 23rd mirror surface is 0.8 mm; The curvature radius of the twenty-third mirror surface is -34 mm, and the mirror distance between the twenty-third mirror surface and the twenty-fourth mirror surface is 1.2 mm; The curvature radius of the 24th mirror surface is 5 mm, and the mirror distance between the 24th mirror surface and the 25th mirror surface is 5.3 mm; The curvature radius of the twenty-fifth mirror surface is 10 mm.

8. The microscope objective lens according to claim 7, characterized in that: The focal length of the tube lens that can be used in conjunction with the microscope objective lens is 200 mm.

9. The microscope objective lens according to claim 1, characterized in that: Also includes: An aperture stop is arranged on the side of the fifth lens group facing the image side.

10. A microscope comprising the microscope objective according to any one of claims 1 to 9.

Images