Microscope objective lens and microscope

Abstract

The utility model 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 technical scheme of the utility model, the specific parameters and structures of the lenses are set, so that the amplification factor of the objective lens of the microscope is-50x, the diameter of the field of view of the object space is 0.57 mm, and the diameter of the field of view of the image space is 28.5 mm, the working distance is 10 mm, and the corresponding numerical aperture is 0.55 under the condition that a 200mm focal length tube lens is used; 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 utility model relates to the field of microscope, in particular to a microscope objective and microscope. BACKGROUND

[0002] Under the condition of the rapid development of micro-nano processing technology, the feature size of integrated circuit is smaller and smaller, in order to adapt to the integrated requirement of gradually improved semiconductor measuring equipment, it is very necessary to adopt microscope objective designed for specific needs. At present, some foreign manufacturers can provide conventional 50 times microscope objective, which can be observed under the supporting optical system. However, these foreign manufacturers will not provide high-order optical parameters of 50 times microscope objective, which leads to the fact that the microscope objective cannot be designed in the semiconductor measuring equipment, the integration of the system is affected, and even the imaging quality of the optical system is reduced. SUMMARY

[0003] An object of the utility model is to effectively improve the imaging quality and image field of microscope objective, and realize the independent design of microscope objective, so that the microscope objective can better match the semiconductor measuring equipment.

[0004] A further object of the utility model is to realize the complex achromatism of the visible light wave band, correct the spherical aberration, coma, astigmatism, field curvature, distortion, axial chromatic aberration and vertical axial chromatic aberration, and meet the requirements of flat field complex achromatic objective.

[0005] In particular, the utility model provides a microscope objective, which comprises: first lens, second lens, first lens group, second lens group, third lens group, fourth lens group, fifth lens group, sixth lens group and seventh lens group arranged in sequence from the object side to the image side along the same optical axis; the first lens is concave on the object side and convex on the image side; the second lens is concave on the object side and convex on 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 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 is concave on the object side and convex on the image side; the second lens group is convex on the object side and convex on the image side; the third lens group is concave on the object side and convex on the image side; the fourth lens group is convex on the object side and convex on the image side; the fifth lens group is concave on the object side and convex on the image side; the sixth lens group is convex on the object side and concave on the image side; and the seventh lens group is concave on the object side and concave on 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 refractive power; the first lens group is a doublet with positive refractive power, comprising a third lens and a fourth lens from the object side; the third lens is concave on the object side and concave on the image side; the fourth lens is convex on the object side and convex on the image side; the second lens group is a doublet with positive refractive power, comprising a fifth lens and a sixth lens from the object side; the fifth lens is convex on the object side and convex on the image side; the sixth lens is concave on the object side and convex on the image side; the third lens group is a doublet with positive refractive power, comprising a seventh lens and an eighth lens from the object side; the seventh lens is concave on the object side and concave on the image side; the eighth lens is convex on the object side and convex on the image side; the fourth lens group is a doublet with positive refractive power, comprising a ninth lens and a tenth lens from the object side; the ninth lens is convex on the object side and concave on the image side; the tenth lens is convex on the object side and convex on the image side; the fifth lens group is a doublet with positive refractive power, comprising an eleventh lens and a twelfth lens from the object side; the eleventh lens is concave on the object side and convex on the image side; the twelfth lens is concave on the object side and convex on the image side; the sixth lens group is a doublet with positive refractive power, comprising a thirteenth lens and a fourteenth lens from the object side; the thirteenth lens is convex on the object side and concave on the image side; the fourteenth lens is convex on the object side and concave on the image side; the seventh lens group is a doublet with negative refractive power, comprising a fifteenth lens and a sixteenth lens from the object side; the fifteenth lens is concave on the object side and concave on the image side; the sixteenth lens is convex on the object side and concave on 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, the sixteenth lens all satisfy the following conditions: 1.56 < nd < 1.65, 35 < Vd < 82, 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; the seventh lens, the ninth lens, the eleventh lens, 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 587.6 nm, and Vd is the Abbe number at a wavelength of 587.6 nm.

[0009] Optionally, the first lens has a refractive index of 1.6 and an Abbe number of 61; the second lens has a refractive index of 1.62 and an Abbe number of 67; the third lens has a refractive index of 1.63 and an Abbe number of 36; the fourth lens has a refractive index of 1.56 and an Abbe number of 71; the fifth lens has a refractive index of 1.55 and an Abbe number of 70; the sixth lens has a refractive index of 1.66 and an Abbe number of 35; the seventh lens has a refractive index of 1.83 and an Abbe number of 26; the eighth lens has a refractive index of 1.55 and an Abbe number of 70; the ninth lens has a refractive index of 1.76 and an Abbe number of 29; the tenth lens has a refractive index of 1.51 and an Abbe number of 80; the eleventh lens has a refractive index of 1.94 and an Abbe number of 19; the twelfth lens has a refractive index of 1.92 and an Abbe number of 32; the thirteenth lens has a refractive index of 1.55 and an Abbe number of 51; the fourteenth lens has a refractive index of 1.60 and an Abbe number of 38; the fifteenth lens has a refractive index of 1.55 and an Abbe number of 38; the sixteenth lens has a refractive index of 1.56 and an Abbe number of 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, the cemented surface of the eleventh lens and the twelfth lens is an eighteenth mirror surface, the surface of the twelfth lens facing the image side is a nineteenth mirror surface, the surface of the thirteenth lens facing the object side is a twentieth mirror surface, the cemented surface of the thirteenth lens and the fourteenth lens is a twenty-first mirror surface, the surface of the fourteenth lens facing the image side is a twenty-second mirror surface, the surface of the fifteenth lens facing the object side is a twenty-third mirror surface, the cemented surface of the fifteenth lens and the sixteenth lens is a twenty-fourth mirror surface, the surface of the sixteenth lens facing the image side is a twenty-fifth mirror surface, the curvatures 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; the curvatures 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.

[0011] Optionally, the radius of curvature of the first mirror is -14 mm, the mirror distance between the first mirror and the second mirror is 2.6 mm; the radius of curvature of the second mirror is -11 mm, the mirror distance between the second mirror and the third mirror is 0.2 mm; the radius of curvature of the third mirror is -53 mm, the mirror distance between the third mirror and the fourth mirror is 3.6 mm; the radius of curvature of the fourth mirror is -16 mm, the mirror distance between the fourth mirror and the fifth mirror is 0.8 mm; the radius of curvature of the fifth mirror is -75 mm, the mirror distance between the fifth mirror and the sixth mirror is 1.2 mm; the radius of curvature of the sixth mirror is 32 mm, the mirror distance between the sixth mirror and the seventh mirror is 5.3 mm; the radius of curvature of the seventh mirror is -23 mm, the mirror distance between the seventh mirror and the eighth mirror is 2.6 mm; the radius of curvature of the eighth mirror is 95 mm, the mirror distance between the eighth mirror and the ninth mirror is 0.2 mm; the radius of curvature of the ninth mirror is -20 mm, the mirror distance between the ninth mirror and the tenth mirror is 3.6 mm; the radius of curvature of the tenth mirror is -35 mm, the mirror distance between the tenth mirror and the eleventh mirror is 0.8 mm; the radius of curvature of the eleventh mirror is -3200 mm, the mirror distance between the eleventh mirror and the twelfth mirror is 1.2 mm; the radius of curvature of the twelfth mirror is 24 mm, the mirror distance between the twelfth mirror and the thirteenth mirror is 5.3 mm; the radius of curvature of the thirteenth mirror is -51 mm, the mirror distance between the thirteenth mirror and the fourteenth mirror is 5.3 mm; the radius of curvature of the fourteenth mirror is 58 mm, the mirror distance between the fourteenth mirror and the fifteenth mirror is 2.6 mm; the radius of curvature of the fifteenth mirror is 17 mm, the mirror distance between the fifteenth mirror and the sixteenth mirror is 0.2 mm; the radius of curvature of the sixteenth mirror is -96 mm, the mirror distance between the sixteenth mirror and the seventeenth mirror is 3.6 mm; the radius of curvature of the seventeenth mirror is -107 mm, the mirror distance between the seventeenth mirror and the eighteenth mirror is 0.8 mm; the radius of curvature of the eighteenth mirror is -14 mm, the mirror distance between the eighteenth mirror and the nineteenth mirror is 1.2 mm; the radius of curvature of the nineteenth mirror is -157 mm, the mirror distance between the nineteenth mirror and the twentieth mirror is 5.3 mm; the radius of curvature of the twentieth mirror is 27 mm, the mirror distance between the twentieth mirror and the twenty-first mirror is 0.2 mm; the radius of curvature of the twenty-first mirror is 7 mm, the mirror distance between the twenty-first mirror and the twenty-second mirror is 3.6 mm; the radius of curvature of the twenty-second mirror is 14 mm, the mirror distance between the twenty-second mirror and the twenty-third mirror is 0.8 mm; the radius of curvature of the twenty-third mirror is -34 mm, the mirror distance between the twenty-third mirror and the twenty-fourth mirror is 1.2 mm; the radius of curvature of the twenty-fourth mirror is 5 mm, the mirror distance between the twenty-fourth mirror and the twenty-fifth mirror is 5.3mm; and a curvature radius of the twenty-fifth mirror is 10mm.

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

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

[0014] According to another aspect of the present application, there is also provided a microscope comprising any one of the microscope objectives described above.

[0015] The microscope objective of the present application has a magnification of -50x, a field of view larger than that of a conventional commercial 50x microscope objective, an object-side field of view diameter of 0.57mm, an image-side field of view diameter of 28.5mm, a working distance of 10mm, and a numerical aperture NA of 0.55 when used in conjunction with a tube lens having a focal length of 200mm. The microscope objective of the present application has a larger image-side field of view than a conventional microscope objective, and is completely designed independently, thereby solving the problem that a conventional 50x microscope objective cannot be well matched with a semiconductor measuring device.

[0016] Further, the microscope objective of the present application can realize achromatism in the visible light wavelength band of 486nm-656nm, and corrects spherical aberration, coma, astigmatism, field curvature, distortion, axial chromatic aberration, and sagittal chromatic aberration, thereby meeting the requirements of a flat-field achromatic objective.

[0017] The above and other objects, advantages and features of the present application will become more apparent from the following detailed description of some embodiments thereof, when considered in conjunction with the annexed drawings in which: BRIEF DESCRIPTION OF DRAWINGS

[0018] Some specific embodiments of the present application will be described in detail below with reference to the accompanying drawings, which are given by way of illustration and thus are not limitative of the present application. Like reference numerals refer to like elements throughout the drawings. It should be understood that the drawings are not necessarily to scale, the emphasis instead being placed upon illustrating the principles of the application. In the drawings:

[0019] Figure 1 is a structural schematic view of a microscope objective according to an embodiment of the present application;

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

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

[0022] Figure 4 is a full field transfer function curve diagram of the microscope objective according to one embodiment of the present utility model;

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

[0024] Figure 6 is a meridional chromatic aberration diagram of the microscope objective according to one embodiment of the present utility model when the maximum field of view is 0.2850mm; and

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

[0026] The embodiment provides a microscope objective, which can effectively improve the imaging quality and image-side field of view of the microscope objective, and further improve the overall performance of the microscope. Figure 1 is a structural schematic diagram of the microscope objective according to one embodiment of the present utility model. As shown in Figure 1 the microscope objective of the embodiment comprises, arranged in sequence from the object side to the image side along the optical axis, 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.

[0027] The first lens L1 is concave on the object side and convex on the image side, and the second lens L2 is concave on the object side and convex on 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 comprise at least two lenses, and the refractive indexes of the at least two lenses in each lens group are different.

[0028] The first lens group G1 is concave on the object side and convex on the image side, the second lens group G2 is convex on the object side and convex on the image side, the third lens group G3 is concave on the object side and convex on the image side, the fourth lens group G4 is convex on the object side and convex on the image side, the fifth lens group G5 is concave on the object side and convex on the image side, the sixth lens group G6 is convex on the object side and concave on the image side, and the seventh lens group G7 is concave on the object side and concave on 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 refractive power. The positive meniscus lens refers to a lens composed of two curved surfaces with similar radii of curvature, which has a positive focal length. The positive meniscus lens can generally 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 collimated light, the light beam can be incident on the concave surface of the positive meniscus lens. In addition, positive refractive power refers to the refractive power of an optical system that converges light rays, with a value greater than zero. An optical system with positive refractive power will cause light rays to converge, i.e. the light beam will become more concentrated after passing through the system. That is, the first lens L1 and the second lens L2 in the embodiment can both converge light rays.

[0031] The first lens group G1 is a doublet lens with positive refractive power, which includes the third lens L3 and the fourth lens L4 from the object side. The third lens L3 is concave on the object side and concave on the image side. The fourth lens L4 is convex on the object side and convex on the image side. The doublet lens refers to a combined lens formed by two lenses glued together, which achieves 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.

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

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

[0034] The seventh lens group G7 is a doublet lens with negative refractive power, comprising a fifteenth lens L15 and a sixteenth lens L16 from the object side; the fifteenth lens L15 is concave on the object side and concave on the image side; the sixteenth lens L16 is convex on the object side and concave on the image side. Wherein, the optical system with negative refractive power will make the light become more divergent, that is, the light beam will become more dispersed after passing through the system. That is, the seventh lens group G7 in the 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, 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.

[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, 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.

[0037] In a preferred embodiment, the specific values of the refractive index and the 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 refractive index of the ninth lens 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] Lens name Refractive index Abbe number First lens L1 1.60 61.00 Second lens L2 1.62 67.00 Third lens L3 1.63 36.00 Fourth lens L4 1.56 71.00 Fifth lens L5 1.55 70.00 Sixth lens L6 1.66 35.00 Seventh lens L7 1.83 26.00 Eighth lens L8 1.55 70.00 Ninth lens L9 1.76 29.00 Tenth lens L10 1.51 80.00 Eleventh lens L11 1.94 19.00 Twelfth lens L12 1.92 32.00 Thirteenth lens L13 1.55 51.00 Fourteenth lens L14 1.60 38.00 Fifteenth lens L15 1.55 38.00 Sixteenth lens L16 1.56 52.00

[0040] In a specific embodiment, the surface of the first lens L1 towards the object side is the first mirror surface S1, the surface of the first lens L1 towards the image side is the second mirror surface S2, the surface of the second lens L2 towards the object side is the third mirror surface S3, the surface of the second lens L2 towards the image side is the fourth mirror surface S4, the surface of the third lens L3 towards the object side is the fifth mirror surface S5, the cemented surface of the third lens L3 and the fourth lens L4 is the sixth mirror surface S6, the surface of the fourth lens L4 towards the image side is the seventh mirror surface S7, the surface of the fifth lens L5 towards the object side is the eighth mirror surface S8, the cemented surface of the fifth lens L5 and the sixth lens L6 is the ninth mirror surface S9, the surface of the sixth lens L6 towards the image side is the tenth mirror surface S10, the surface of the seventh lens L7 towards the object side is the eleventh mirror surface S11, the cemented surface of the seventh lens L7 and the eighth lens L8 is the twelfth mirror surface S12, the surface of the eighth lens L8 towards the image side is the thirteenth mirror surface S13.

[0041] 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 surface of the thirteenth lens 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.

[0042] In a preferred embodiment, the specific values of the radii of curvature of the first mirror surface S1 to the twenty-fifth mirror surface S25 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 -14 mm, and the mirror surface 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 surface 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 surface 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 surface 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 surface 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 surface distance between the sixth mirror surface S6 and the seventh mirror surface S7 is 5.3 mm; the radius of curvature of the seventh mirror surface S7 is -23 mm, and the mirror surface distance between the seventh mirror surface S7 and the eighth mirror surface S8 is 2.6 mm; the radius of curvature of the eighth mirror surface S8 is 95 mm, and the mirror surface distance between the eighth mirror surface S8 and the ninth mirror surface S9 is 0.2 mm; the radius of curvature of the ninth mirror surface S9 is -20 mm, and the mirror surface distance between the ninth mirror surface S9 and the tenth mirror surface S10 is 3.6 mm; the radius of curvature of the tenth mirror surface S10 is -35 mm, and the mirror surface distance between the tenth mirror surface S10 and the eleventh mirror surface S11 is 0.8 mm; the radius of curvature of the eleventh mirror surface S11 is -3200 mm, and the mirror surface distance between the eleventh mirror surface S11 and the twelfth mirror surface S12 is 1.2 mm; the radius of curvature of the twelfth mirror surface S12 is 24 mm, and the mirror surface distance between the twelfth mirror surface S12 and the thirteenth mirror surface S13 is 5.3 mm.

[0043] The radius of curvature of the thirteenth mirror S13 is -51 mm, the mirror distance between the thirteenth mirror S13 and the fourteenth mirror S14 is 5.3 mm; the radius of curvature of the fourteenth mirror S14 is 58 mm, the mirror distance between the fourteenth mirror S14 and the fifteenth mirror S15 is 2.6 mm; the radius of curvature of the fifteenth mirror S15 is 17 mm, the mirror distance between the fifteenth mirror S15 and the sixteenth mirror S16 is 0.2 mm; the radius of curvature of the sixteenth mirror S16 is -96 mm, the mirror distance between the sixteenth mirror S16 and the seventeenth mirror S17 is 3.6 mm; the radius of curvature of the seventeenth mirror S17 is -107 mm, the mirror distance between the seventeenth mirror S17 and the eighteenth mirror S18 is 0.8 mm; the radius of curvature of the eighteenth mirror S18 is -14 mm, the mirror distance between the eighteenth mirror S18 and the nineteenth mirror S19 is 1.2 mm; the radius of curvature of the nineteenth mirror S19 is -157 mm, the mirror distance between the nineteenth mirror S19 and the twentieth mirror S20 is 5.3 mm; the radius of curvature of the twentieth mirror S20 is 27 mm, the mirror distance between the twentieth mirror S20 and the twenty-first mirror S21 is 0.2 mm; the radius of curvature of the twenty-first mirror S21 is 7 mm, the mirror distance between the twenty-first mirror S21 and the twenty-second mirror S22 is 3.6 mm; the radius of curvature of the twenty-second mirror S22 is 14 mm, the mirror distance between the twenty-second mirror S22 and the twenty-third mirror S23 is 0.8 mm; the radius of curvature of the twenty-third mirror S23 is -34 mm, the mirror distance between the twenty-third mirror S23 and the twenty-fourth mirror S24 is 1.2 mm; the radius of curvature of the twenty-fourth mirror S24 is 5 mm, the mirror distance between the twenty-fourth mirror S24 and the twenty-fifth mirror S25 is 5.3 mm; the radius of curvature of the twenty-fifth mirror S25 is 10 mm.

[0044] Table 2

[0045] Mirror name Curvature radius (mm) Mirror distance (mm) First mirror S1 -14.00 2.60 Second mirror S2 -11.00 0.20 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 Eighth mirror S8 95.00 8.80 Ninth mirror S9 -20.00 1.20 Tenth mirror S10 -35.00 5.50 Eleventh mirror S11 -3200.00 0.50 Twelfth mirror S12 24.00 4.20 Thirteenth mirror S13 -51.00 1.50 Fourteenth mirror S14 58.00 3.50 Fifteenth mirror S15 17.00 3.90 Sixteenth mirror S16 -96.00 3.40 Seventeenth mirror S17 -107.00 4.50 Eighteenth mirror S18 -14.00 1.20 Nineteenth mirror S19 -157.00 0.30 Twentieth mirror S20 27.00 14.50 Twenty-first mirror S21 7.00 13.10 Twenty-second mirror S22 14.00 1.20 Twenty-third mirror S23 -34.00 1.20 Twenty-fourth mirror S24 5.00 1.50 Twenty-fifth mirror S25 10 Infinite

[0046] According to the specific parameters and structures of each lens in the above table 1 and table 2, the magnification of the microscope objective is -50x, the image field is 28.5 mm, the numerical aperture is 0.55, and the focal length of the tube lens that can be used is 200 mm. The microscope objective of the present embodiment has higher image field than the conventional objective, and is completely designed independently, which solves the problem that the existing 50x objective cannot be well matched with the semiconductor measurement equipment.

[0047] In a preferred embodiment, the microscope objective can further comprise: an aperture stop AS arranged on the side of the fifth lens group G5 facing the image side. The aperture stop AS functions to limit the passing aperture of the light beam. Since the aperture stop AS is a plane, its radius of curvature is infinite. Moreover, the mirror surface distance of the aperture stop AS to the twentieth mirror surface S20 can be 4.5 mm. In addition, it needs to be noted that since the object surface is a plane, its radius of curvature is infinite. Moreover, the mirror surface distance of the object surface to the first mirror surface S1 can be 10 mm. The mirror surface distance between the twenty-fifth mirror surface S25 and the image surface is infinite.

[0048] Figure 2 is a full field full wavelength spot diagram of a microscope objective according to an embodiment of the present application. Figure 2 It is shown that the focusing of light with a wavelength of 0.486133 μm to 0.656273 μm at the focal point under different image field of view. The object surface half field of view of field of view (1) is 0.285 mm, the object surface half field of view of field of view (2) is 0.200 mm, and the object surface half field of view of field of view (3) is 0.000 mm. Since the magnification of the objective is -50x, the image surface field of view is the object surface half field of view * 2 * 50. The image surface field of view corresponding to field of view (1), (2), (3) is 28.5 mm, 20.0 mm and 0.0 mm respectively. The data during testing are as follows: the Airy disk radius (diffraction limit) is 0.652 μm, the RMS radius (root mean square) when the field of view is (1) is 0.236 μm, the GEO radius (maximum) is 0.648 μm, the RMS radius when the field of view is (2) is 0.150 μm, the GEO radius is 0.353 μm, the RMS radius when the field of view is (3) is 0.057 μm, and the GEO radius is 0.161 μm.

[0049] wherein the RMS radius is also referred to as the 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 quadratic 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 capable of meeting all light rays falling within its range. Figure 2 It can be known that the focused spots of light of different wavelengths under different fields of view are all within the Airy disk range, which indicates that the microscope objective of the embodiment has excellent focusing effect. The spot diagram is better than the diffraction limit, and it can be known that the microscope objective of the embodiment has good aberration control and basically reaches the system limit.

[0050] Figure 3 is a lateral aberration diagram of a microscope objective according to an embodiment of the present application. Figure 3The horizontal coordinates Px, Py in the figure represent the entrance pupil position, and the vertical coordinates ex, ey represent the beam distribution at the image plane (lateral aberration), y represents the meridional direction, and x represents the sagittal direction. Figure 3 The lateral aberration of light of different wavelengths at different entrance pupil positions is shown when the image plane field of view is 28.5 mm, 20.0 mm and 0.0 mm. Among them, the image plane field of view corresponding to the fields (1), (2) and (3) is 28.5 mm, 20.0 mm and 0.0 mm respectively. As shown in the figure, Figure 3 The lateral aberration of light of different wavelengths at different entrance pupil positions is shown when the image plane field of view is 28.5 mm, 20.0 mm and 0.0 mm. Among them, the image plane field of view corresponding to the fields (1), (2) and (3) is 28.5 mm, 20.0 mm and 0.0 mm respectively. As shown in the figure,

[0051] Figure 4 The figure is a full field of view transfer function curve of the microscope objective according to an embodiment of the utility model. Figure 4 The vertical coordinate is the modulus value of the normalized transfer function, and the horizontal coordinate 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 the figure, Figure 4 The transfer function curves of the meridional plane and the sagittal plane of the microscope objective of the embodiment 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 when the image plane field of view is 28.5 mm, 20.0 mm and 0.0 mm, which indicates that the imaging contrast of the full field of view of the optical system is very high, and the imaging level is clear.

[0052] Figure 5 The figure is an axial aberration graph of the microscope objective according to an embodiment of the utility model when the pupil radius is 2.2000 mm. Figure 5 The vertical coordinate is the normalized pupil coordinate, and the horizontal coordinate is the axial aberration, with the unit of mm, Figure 5 The figure shows the axial aberration graph of light of different wavelengths when the pupil radius is 2.2000 mm. As shown in the figure, Figure 5 The axial aberration of each wavelength is less than 0.0003 mm, which meets the complex achromatism level of the axial aberration of each entrance pupil position of any two wavelengths. It should be noted that the axial aberration can also be called longitudinal aberration, axial chromatic aberration or longitudinal chromatic aberration.

[0053] Figure 6 The figure is a perpendicular axis chromatic aberration graph of the microscope objective according to an embodiment of the utility model when the maximum field of view is 0.2850 mm. Figure 6 The vertical coordinate is the field of view, with the unit of mm, and the horizontal coordinate is the lateral aberration, with the unit of μm. Figure 6 The figure shows the perpendicular axis chromatic aberration graph of light of different wavelengths when the maximum field of view is 0.2850 mm, where the maximum field of view 0.2850 mm refers to the object plane half field of view.Figure 6 The curve in represents the size of the diffraction-limited Airy disk of the system, as Figure 6 As shown, the vertical chromatic aberration of light of different wavelengths is kept within the size of the system's diffraction-limited Airy disk when the maximum field of view is 0.2850mm, and the vertical chromatic aberration is well controlled.

[0054] Figure 7 4 is a field curvature distortion diagram of a microscope objective lens according to an embodiment of the present utility model. Figure 7 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 objective lens, and the horizontal axis is the field curvature value, in μm. Figure 7 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 4.099 degrees, the sagittal field curvature is 0.0002mm, and the meridional 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 ​​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.

[0055] This embodiment also provides a microscope, comprising 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 microscope objective lens has a magnification of -50x, a field of view greater than that of a conventional commercial 50x microscope objective lens, an object-side field of view diameter of 0.57mm, and, when using a 200mm focal length tube lens, an image-side field of view diameter of 28.5mm, a working distance of 10mm, and a correspondingly large numerical aperture (NA) of 0.55. Apochromatism can be achieved in the visible light band of 486nm-656nm, with excellent correction of spherical aberration, coma, astigmatism, field curvature, distortion, axial chromatic aberration, and vertical chromatic aberration, meeting the requirements of a plan-apochromat objective lens.

[0056] 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.

[0057] 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.

[0058] Unless otherwise defined, the terms "mounting", "connected", "connecting", "fixed", and "fixedly connected" 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, or 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.

[0059] 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 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.

[0060] In the description of the present embodiment, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" 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 exemplary 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.

[0061] 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 objective, characterized in that Comprise: 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 arranged in sequence from the object side to the image side along the optical axis; the first lens is concave towards the object side and convex towards the image side; the second lens is concave towards the object side and convex towards 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 each comprise at least two lenses, and the refractive indices of the at least two lenses in each lens group are different; the first lens group is concave towards the object side and convex towards the image side; the second lens group is convex towards the object side and convex towards the image side; the third lens group is concave towards the object side and convex towards the image side; the fourth lens group is convex towards the object side and convex towards the image side; the fifth lens group is concave towards the object side and convex towards the image side; the sixth lens group is convex towards the object side and concave towards the image side; and the seventh lens group is concave towards the object side and concave towards the image side.

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

4. The microscope objective 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, the sixteenth lens all satisfy the following conditions: 1.56 < nd < 1.65, 35 < Vd < 82, 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; The seventh lens, the ninth lens, the eleventh lens, 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 587.6 nm, and Vd is the Abbe number at a wavelength of 587.6 nm.

5. The microscope objective 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 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.

6. The microscope objective 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 a third mirror surface, and 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, and 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, and 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, and 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, and 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, the cemented surface of the eleventh lens and the twelfth lens is an eighteenth mirror surface, and the surface of the twelfth lens facing the image side is a nineteenth mirror surface, the surface of the thirteenth lens facing the object side is a twentieth mirror surface, the cemented surface of the thirteenth lens and the fourteenth lens is a twenty-first mirror surface, and the surface of the fourteenth lens facing the image side is a twenty-second mirror surface, the surface of the fifteenth lens facing the object side is a twenty-third mirror surface, the cemented surface of the fifteenth lens and the sixteenth lens is a twenty-fourth mirror surface, and the surface of the sixteenth lens facing the image side is a twenty-fifth mirror surface, the radii of curvature 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 radii of curvature 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 according to claim 6, characterized in that the radius of curvature of the first mirror surface is -14 mm, and the mirror surface distance between the first mirror surface and the second mirror surface is 2.6 mm; the radius of curvature of the second mirror surface is -11 mm, and the mirror surface distance between the second mirror surface and the third mirror surface is 0.2 mm; the radius of curvature of the third mirror surface is -53 mm, and the mirror surface distance between the third mirror surface and the fourth mirror surface is 3.6 mm; the radius of curvature of the fourth mirror surface is -16 mm, and the mirror surface 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 surface 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 surface 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 surface 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 surface 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 surface 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 surface 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 surface 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 surface 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 surface 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 surface 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 surface 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 surface 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 surface 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 surface 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 surface distance between the nineteenth mirror surface and the twentieth mirror surface is 5.3 mm; The curvature radius of the twentieth mirror surface is 27 mm, and the mirror surface distance between the twentieth mirror surface and the twenty-first mirror surface is 0.2 mm; The curvature radius of the twenty-first mirror surface is 7 mm, and the mirror surface distance between the twenty-first mirror surface and the twenty-second mirror surface is 3.6 mm; The curvature radius of the twenty-second mirror surface is 14 mm, and the mirror surface distance between the twenty-second mirror surface and the twenty-third mirror surface is 0.8 mm; The curvature radius of the twenty-third mirror surface is -34 mm, and the mirror surface distance between the twenty-third mirror surface and the twenty-fourth mirror surface is 1.2 mm; The curvature radius of the twenty-fourth mirror surface is 5 mm, and the mirror surface distance between the twenty-fourth mirror surface and the twenty-fifth mirror surface is 5.3 mm; The curvature radius of the twenty-fifth mirror surface is 10 mm.

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

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

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

Images