Microscope objective and microscope

Abstract

This invention provides a microscope objective and a microscope. The microscope objective includes: a first lens, a second lens, a third lens, a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group, a fourteenth lens, and a sixth lens group, arranged coaxially from the object side to the image side. This invention, through the arrangement of the lenses, achieves a microscope objective with a magnification of -50x, an object-side field of view diameter of 0.57mm, and, using a 200mm focal length tube, an image-side field of view diameter of 28.5mm, a working distance of 10mm, and a corresponding numerical aperture of 0.55. It achieves apochromatic aberration in the 400nm-700nm visible light band, effectively correcting spherical aberration, coma, astigmatism, field curvature, distortion, axial chromatic aberration, and transverse chromatic aberration, meeting the requirements of a plan-field apochromatic objective. While improving image quality, it possesses an image-side field of view greater than conventional objectives, solving the problem that existing 50x objectives cannot be well matched with semiconductor measurement equipment.

Description

Technical Field

[0001] This utility model relates to the field of microscopes, and in particular to a microscope objective and a microscope. Background Technology

[0002] With the rapid development of micro-nano fabrication technology, the feature size of integrated circuits is becoming increasingly smaller. To meet the ever-increasing integration requirements of semiconductor metrology equipment, it is essential to use microscope objectives designed specifically for these needs. Currently, some foreign manufacturers can provide standard 50x microscope objectives for observation using a matching optical system. However, these foreign manufacturers do not provide the high-order optical parameters of the 50x microscope objectives. This makes it impossible to design microscope objectives specifically for use in semiconductor metrology equipment, affecting the system's integration and potentially even reducing the imaging quality of the optical system. Utility Model Content

[0003] One objective of this invention is to effectively improve the imaging quality and image-side field of view of microscope objectives, and to achieve independent design of microscope objectives, so that microscope objectives can be better matched with semiconductor measurement equipment.

[0004] A further objective of this invention is to achieve apochromatic correction in the visible light band, correcting spherical aberration, coma, astigmatism, field curvature, distortion, axial chromatic aberration, and transverse chromatic aberration, thus meeting the requirements of a plan apochromatic objective lens.

[0005] In particular, this utility model provides a microscope objective lens, comprising: a first lens, a second lens, a third lens, a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group, a fourteenth lens, and a sixth lens group arranged coaxially from the object side to the image side; The first lens has a concave surface facing the object and a convex surface facing the image; the second lens has a concave surface facing the object and a convex surface facing the image; the third lens has a concave surface facing the object and a convex surface facing the image; the fourteenth lens has a convex surface facing the object and a concave surface facing the image. The first lens group, the second lens group, the third lens group, the fourth lens group, the fifth lens group, and the sixth lens group each include at least two lenses, and the at least two lenses in each lens group have different refractive indices; The first lens group has a convex surface facing both the object and image sides; the second lens group has a concave surface facing both the object and image sides; the third lens group has a convex surface facing both the object and image sides; the fourth lens group has a convex surface facing both the object and image sides; the fifth lens group has a convex surface facing both the object and image sides; and the sixth lens group has a concave surface facing both the object and image sides.

[0006] Optionally, 339.5 < fL1 / f < 42.5, 172.5 < fL2 / f < 175.5, 34.5 < fL3 / f < 37.5, 43.5 < fG1 / f < 46.5, -46.5 < fG2 / f < -43.5, 63.5 < fG3 / f < 66.5, 92.5 < fG4 / f < 95.5, -85.5 < fG5 / f < -81.5, -201.5 < fL14 / f < -198.5, -49.5 < fG6 / f < -45.5. Where fL1 is the focal length of the first lens, fL2 is the focal length of the second lens, fL3 is the focal length of the third 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, fL14 is the focal length of the fourteenth lens, fG6 is the focal length of the sixth lens group, and f is the focal length of the microscope objective.

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

[0008] Optionally, the third lens, fourth lens, eighth lens, eleventh lens, twelfth lens, and sixteenth lens all satisfy the following conditions: 1.40≤nd≤1.60, 66≤Vd≤96, 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 first, second, fifth, sixth, seventh, ninth, tenth, thirteenth, fourteenth, and fifteenth lenses all satisfy the following conditions: 1.60≤nd≤1.85, 24≤Vd≤57, 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 first lens has a refractive index of 1.70 and an Abbe number of 30.00; The second lens has a refractive index of 1.62 and an Abbe number of 35.92. The refractive index of the third lens is 1.44, and the Abbe number is 94.55. The fourth lens has a refractive index of 1.44 and an Abbe number of 94.50. The fifth lens has a refractive index of 1.60 and an Abbe number of 38.00. The sixth lens has a refractive index of 1.79 and an Abbe number of 47.48. The seventh lens has a refractive index of 1.81 and an Abbe number of 25.38. The eighth lens has a refractive index of 1.58 and an Abbe number of 68.30. The ninth lens has a refractive index of 1.64 and an Abbe number of 35.39. The tenth lens has a refractive index of 1.67 and an Abbe number of 32.19. The eleventh lens has a refractive index of 1.55 and an Abbe number of 75.23. The twelfth lens has a refractive index of 1.57 and an Abbe number of 71.30. The refractive index of the thirteenth lens is 1.61, and the Abbe number is 44.10. The fourteenth lens has a refractive index of 1.68 and an Abbe number of 55.52. The refractive index of the fifteenth lens is 1.80, and the Abbe number is 34.97. The sixteenth lens has a refractive index of 1.50 and an Abbe number of 81.61.

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

[0011] Optionally, the radius of curvature of the first mirror is -10.00 mm, and the mirror distance between the first and second mirrors is 2.20 mm; the radius of curvature of the second mirror is -8.20 mm, and the mirror distance between the second and third mirrors is 0.20 mm; the radius of curvature of the third mirror is -22.00 mm, and the mirror distance between the third and fourth mirrors is 1.30 mm; the radius of curvature of the fourth mirror is -18.80 mm, and the mirror distance between the fourth and fifth mirrors is 0.20 mm; the radius of curvature of the fifth mirror is -145.50 mm, and the mirror distance between the fifth and sixth mirrors is 3.00 mm; the radius of curvature of the sixth mirror is -15.00 mm, and the mirror distance between the sixth and seventh mirrors is... The distance between the mirror surfaces is 0.20 mm; the radius of curvature of the seventh mirror is 64.00 mm, and the distance between the seventh and eighth mirror surfaces is 3.80 mm; the radius of curvature of the eighth mirror is -16.00 mm, and the distance between the eighth and ninth mirror surfaces is 1.00 mm; the radius of curvature of the ninth mirror is -23.00 mm, and the distance between the ninth and tenth mirror surfaces is 0.20 mm; the radius of curvature of the tenth mirror is -10000.00 mm, and the distance between the tenth and eleventh mirror surfaces is 1.00 mm; the radius of curvature of the eleventh mirror is 16.00 mm, and the distance between the eleventh and twelfth mirror surfaces is 2.00 mm; the radius of curvature of the twelfth mirror is... The radius of curvature of the 13th mirror is 34.00mm, and the mirror distance between the 12th and 13th mirrors is 0.80mm; the radius of curvature of the 13th mirror is 58.00mm, and the mirror distance between the 13th and 14th mirrors is 4.00mm; the radius of curvature of the 14th mirror is -14.00mm, and the mirror distance between the 14th and 15th mirrors is 1.00mm; the radius of curvature of the 15th mirror is -71.50mm, and the mirror distance between the 15th and 16th mirrors is 0.20mm; the radius of curvature of the 16th mirror is 110.00mm, and the mirror distance between the 16th and 17th mirrors is 1.00mm; the radius of curvature of the 17th mirror is 15.00mm, and the mirror distance between the 17th and 18th mirrors is... The distance between the mirrors is 4.00 mm; the radius of curvature of the eighteenth mirror is -41.00 mm, and the distance between the eighteenth and nineteenth mirrors is 0.20 mm; the radius of curvature of the nineteenth mirror is 25.00 mm, and the distance between the nineteenth and twentieth mirrors is 3.80 mm; the radius of curvature of the twentieth mirror is -18.00 mm, and the distance between the twentieth and twenty-first mirrors is 1.00 mm; the radius of curvature of the twenty-first mirror is 18.00 mm, and the distance between the twenty-first and twenty-second mirrors is 1.90 mm; the radius of curvature of the twenty-second mirror is 15.50 mm, and the distance between the twenty-second and twenty-third mirrors is 21 mm.The radius of curvature of the 23rd mirror is 6.20mm, and the mirror distance between the 23rd and 24th mirrors is 1.30mm; the radius of curvature of the 24th mirror is -38.50mm, and the mirror distance between the 24th and 25th mirrors is 1.30mm; the radius of curvature of the 25th mirror is -6.80mm, and the mirror distance between the 25th and 26th mirrors is 1.00mm; the radius of curvature of the 26th mirror is 10.50mm.

[0012] Optionally, the microscope objectives can be used with tube lenses with focal lengths including 200 mm.

[0013] Optionally, the microscope objective also includes an aperture stop, positioned on the image-facing side of the fifth lens group; The mirror distance between the aperture stop and the twenty-second mirror is 26.00 mm.

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

[0015] This invention relates to a microscope objective. By setting specific parameters and structures for each lens, the microscope objective achieves a magnification of -50x, a field of view exceeding that of conventional commercial 50x microscope objectives, an object-side field of view diameter of 0.57mm, and an image-side field of view diameter of 28.5mm when using a 200mm focal length tube lens. The working distance is 10mm, and the corresponding numerical aperture (NA) is relatively large at 0.55. While improving image quality, this microscope objective provides an image-side field of view greater than conventional objectives and is entirely independently designed, solving the problem that existing 50x objectives cannot be well matched with semiconductor measurement equipment.

[0016] Furthermore, the microscope objective of this invention can achieve apochromatic aberration in the 400nm-700nm visible light band, and effectively corrects spherical aberration, coma, astigmatism, field curvature, distortion, axial chromatic aberration, and transverse chromatic aberration, thus meeting the requirements of a plan apochromatic objective.

[0017] The above and other objects, advantages and features of this utility model will become more apparent to those skilled in the art from the following detailed description of specific embodiments of this utility model in conjunction with the accompanying drawings. Attached Figure Description

[0018] The following sections will describe some specific embodiments of the present invention in a detailed manner by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or components. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings: Figure 1This is a schematic diagram of the structure of a microscope objective lens according to an embodiment of the present invention; Figure 2 This is a full-field, full-wavelength dot plot of a microscope objective lens according to an embodiment of the present invention; Figure 3 This is a lateral aberration diagram of a microscope objective lens according to an embodiment of the present invention; Figure 4 This is a full-field transfer function curve of a microscope objective lens according to an embodiment of the present invention; Figure 5 This is an axial aberration diagram of a microscope objective lens according to an embodiment of the present invention; Figure 6 This is a transverse chromatic aberration diagram of a microscope objective lens according to an embodiment of the present invention at a maximum field of view of 0.2850 mm; and Figure 7 This is a field curvature distortion diagram of a microscope objective lens according to an embodiment of the present invention. Detailed Implementation

[0019] This embodiment provides a microscope objective that can effectively improve the imaging quality and image-side field of view of the microscope objective, thereby enhancing the overall performance of the microscope. Figure 1 This is a 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 lens in this embodiment includes: The first lens L1, the second lens L2, the third lens L3, 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 fourteenth lens L14, and the sixth lens group G6 are arranged coaxially from the object side to the image side.

[0020] The first lens L1 has a concave surface facing the object and a convex surface facing the image; the second lens L2 has a concave surface facing the object and a convex surface facing the image; the third lens L3 has a concave surface facing the object and a convex surface facing the image; and the fourteenth lens L14 has a convex surface facing the object and a concave surface facing the image.

[0021] 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, and the sixth lens group G6 each include at least two lenses, and the at least two lenses in each lens group have different refractive indices.

[0022] The first lens group G1 has a convex surface facing both the object and image sides; the second lens group G2 has a concave surface facing both the object and image sides; the third lens group G3 has a convex surface facing both the object and image sides; the fourth lens group G4 has a convex surface facing both the object and image sides; the fifth lens group G5 has a convex surface facing both the object and image sides; and the sixth lens group G6 has a concave surface facing both the object and image sides.

[0023] In some alternative embodiments, 39.5 < fL1 / f < 42.5, 172.5 < fL2 / f < 175.5, 34.5 < fL3 / f < 37.5, 43.5 < fG1 / f < 46.5, -46.5 < fG2 / f < -43.5, 63.5 < fG3 / f < 66.5, 92.5 < fG4 / f < 95.5, -85.5 < fG5 / f < -81.5, -201.5 < fL14 / f < -198.5, -4 ... G6 / f < -45.5, where fL1 is the focal length of the first lens L1, fL2 is the focal length of the second lens L2, fL3 is the focal length of the third lens L3, 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, fL14 is the focal length of the fourteenth lens L14, fG6 is the focal length of the sixth lens group G6, and f is the focal length of the microscope objective.

[0024] In some preferred embodiments, the first lens L1, the second lens L2, and the third lens L3 are all positive meniscus lenses with positive optical power; a positive meniscus lens is a lens composed of two surfaces with similar radii of curvature, possessing a positive focal length. Positive meniscus lenses are typically used to reduce the focal length of another lens and increase the numerical aperture. When expanding, contracting, 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 collimation, the light beam can be incident on the concave surface of the positive meniscus lens. Furthermore, positive optical power refers to the optical power of an optical system that converges light rays, and its value is greater than zero. An optical system with positive optical power will converge light rays, meaning that the light beam becomes more concentrated after passing through the system. In other words, in this embodiment, the first lens L1, the second lens L2, and the third lens L3 can all converge light rays.

[0025] The first lens group G1 is a cemented doublet lens with positive optical power, comprising a fourth lens L4 and a fifth lens L5 starting from the object side. Lens L4 is convex both facing the object and the image side; lens L5 is concave both facing the object and the image side. A cemented doublet lens is a composite lens formed by cementing two lenses together, achieving better imaging results through the combination of the two lenses. Compared to a single lens, a cemented doublet lens can achieve a shorter focal length, greater magnification, better image quality, and higher axial resolution.

[0026] The second lens group G2 is a cemented doublet with negative optical power, including a sixth lens L6 and a seventh lens L7 starting from the object side; the sixth lens L6 has a concave surface facing both the object and image sides; the seventh lens L7 has a convex surface facing both the object and image sides. The negative optical power system makes light rays more divergent, meaning the light beam becomes more dispersed after passing through this system. In other words, the second lens group G2 in this embodiment can make light rays more divergent.

[0027] The third lens group G3 is a cemented doublet with positive optical power, including the eighth lens L8 and the ninth lens L9 starting from the object side; the eighth lens L8 is convex when facing the object side and convex when facing the image side; the ninth lens L9 is concave when facing the object side and convex when facing the image side.

[0028] The fourth lens group G4 is a cemented doublet with positive optical power, including the tenth lens L10 and the eleventh lens L11 starting from the object side; the tenth lens L10 is convex when facing the object side and concave when facing the image side; the eleventh lens L11 is convex when facing the object side and convex when facing the image side.

[0029] The fifth lens group G5 is a cemented doublet with negative optical power, including the twelfth lens L12 and the thirteenth lens L13 starting from the object side; the twelfth lens L12 is convex when facing the object side and convex when facing the image side; the thirteenth lens L13 is concave when facing the object side and concave when facing the image side.

[0030] The fourteenth lens, L14, is a negative meniscus lens with negative optical power.

[0031] The sixth lens group G6 is a cemented doublet with negative optical power, including the fifteenth lens L15 and the sixteenth lens L16 starting from the object side; the fifteenth lens L15 is concave when facing the object side and convex when facing the image side; the sixteenth lens L16 is concave when facing the object side and concave when facing the image side.

[0032] In some optional embodiments, the third lens L3, the fourth lens L4, the eighth lens L8, the eleventh lens L11, the twelfth lens L12, and the sixteenth lens L16 all satisfy the following conditions: 1.40≤nd≤1.60, 66≤Vd≤96, where nd is the refractive index at a wavelength of 587.6nm and Vd is the Abbe number at a wavelength of 587.6nm. Lenses L1, L2, L5, L6, L7, L9, L10, L13, L14, and L15 all satisfy the following conditions: 1.60 ≤ nd ≤ 1.85, 24 ≤ Vd ≤ 57, 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.

[0033] 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 be referred to Table 1. As shown in Table 1, the refractive index of the first lens L1 is 1.70 and the Abbe number is 30.00; the refractive index of the second lens L2 is 1.62 and the Abbe number is 35.92; the refractive index of the third lens L3 is 1.44 and the Abbe number is 94.55; the refractive index of the fourth lens L4 is 1.44 and the Abbe number is 94.50; the refractive index of the fifth lens L5 is 1.60 and the Abbe number is 38.00; the refractive index of the sixth lens L6 is 1.79 and the Abbe number is 47.48; the refractive index of the seventh lens L7 is 1.81 and the Abbe number is 25.38; the refractive index of the eighth lens L8 is 1.58 and the Abbe number is 68.30; the ninth lens L1... Lens L9 has a refractive index of 1.64 and an Abbe number of 35.39; the tenth lens L10 has a refractive index of 1.67 and an Abbe number of 32.19; the eleventh lens L11 has a refractive index of 1.55 and an Abbe number of 75.23; the twelfth lens L12 has a refractive index of 1.57 and an Abbe number of 71.30; the thirteenth lens L13 has a refractive index of 1.61 and an Abbe number of 44.10; the fourteenth lens L14 has a refractive index of 1.68 and an Abbe number of 55.52; the fifteenth lens L15 has a refractive index of 1.80 and an Abbe number of 34.97; and the sixteenth lens L16 has a refractive index of 1.50 and an Abbe number of 81.61.

[0034] Table 1 In some optional embodiments, the object-facing surface of the first lens L1 is the first mirror surface S1, and the image-facing surface of the first lens L1 is the second mirror surface S2; the object-facing surface of the second lens L2 is the third mirror surface S3, and the image-facing surface of the second lens L2 is the fourth mirror surface S4; the object-facing surface of the third lens L3 is the fifth mirror surface S5, and the image-facing surface of the third lens L3 is the sixth mirror surface S6; the object-facing surface of the fourth lens L4 is the seventh mirror surface S7, the cemented surface of the fourth lens L4 and the fifth lens L5 is the eighth mirror surface S8, and the image-facing surface of the fifth lens L5 is the ninth mirror surface S9; the object-facing surface of the sixth lens L6 is the tenth mirror surface S10, the cemented surface of the sixth lens L6 and the seventh lens L7 is the eleventh mirror surface S11, and the image-facing surface of the seventh lens L7 is the twelfth mirror surface S12.

[0035] The object-facing surface of the eighth lens L8 is the thirteenth mirror surface S13; the cemented surface of the eighth lens L8 and the ninth lens L9 is the fourteenth mirror surface S14; the image-facing surface of the ninth lens L9 is the fifteenth mirror surface S15; the object-facing surface of the tenth lens L10 is the sixteenth mirror surface S16; the cemented surface of the tenth lens L10 and the eleventh lens L11 is the seventeenth mirror surface S17; the image-facing surface of the eleventh lens L11 is the eighteenth mirror surface S18; the object-facing surface of the twelfth lens L12 is the nineteenth mirror surface S19; the object-facing surface of the twelfth lens L12... The cemented surface of the thirteenth lens L13 is the twentieth mirror surface S20, and the image-facing surface of the thirteenth lens L13 is the twenty-first mirror surface S21; the object-facing surface of the fourteenth lens L14 is the twenty-second mirror surface S22, and the image-facing surface of the fourteenth lens L14 is the twenty-third mirror surface S23; the object-facing surface of the fifteenth lens L15 is the twenty-fourth mirror surface S24, the cemented surface of the fifteenth lens L15 and the sixteenth lens L16 is the twenty-fifth mirror surface S25, and the image-facing surface of the sixteenth lens L16 is the twenty-sixth mirror surface S26.

[0036] Among them, the radii of curvature of the first mirror S1, the second mirror S2, the third mirror S3, the fourth mirror S4, the fifth mirror S5, the sixth mirror S6, the eighth mirror S8, the ninth mirror S9, the tenth mirror S10, the fourteenth mirror S14, the fifteenth mirror S15, the eighteenth mirror S18, the twentieth mirror S20, the twenty-fourth mirror S24, and the twenty-fifth mirror S25 are negative; while the radii of curvature of the seventh mirror S7, the eleventh mirror S11, the twelfth mirror S12, the thirteenth mirror S13, the sixteenth mirror S16, the seventeenth mirror S17, the nineteenth mirror S19, the twenty-first mirror S21, the twenty-second mirror S22, the twenty-third mirror S23, and the twenty-sixth mirror S26 are positive.

[0037] In a preferred embodiment, the specific values ​​of the radii of curvature of the first mirror S1 to the twenty-sixth mirror S26 and the mirror distance between two adjacent mirrors can be found in Table 2. As shown in Table 2, the radius of curvature of the first mirror S1 is -10.00 mm, and the mirror distance between the first mirror S1 and the second mirror S2 is 2.20 mm; the radius of curvature of the second mirror S2 is -8.20 mm, and the mirror distance between the second mirror S2 and the third mirror S3 is 0.20 mm; the radius of curvature of the third mirror S3 is -22.00 mm, and the mirror distance between the third mirror S3 and the fourth mirror S4 is 1.30 mm. The radius of curvature of the fourth mirror surface S4 is -18.80 mm, and the mirror distance between the fourth mirror surface S4 and the fifth mirror surface S5 is 0.20 mm; the radius of curvature of the fifth mirror surface S5 is -145.50 mm, and the mirror distance between the fifth mirror surface S5 and the sixth mirror surface S6 is 3.00 mm; the radius of curvature of the sixth mirror surface S6 is -15.00 mm, and the mirror distance between the sixth mirror surface S6 and the seventh mirror surface S7 is 0.20 mm; the seventh mirror surface S... The radius of curvature of mirror S7 is 64.00 mm, and the mirror distance between the seventh mirror S7 and the eighth mirror S8 is 3.80 mm; the radius of curvature of the eighth mirror S8 is -16.00 mm, and the mirror distance between the eighth mirror S8 and the ninth mirror S9 is 1.00 mm; the radius of curvature of the ninth mirror S9 is -23.00 mm, and the mirror distance between the ninth mirror S9 and the tenth mirror S10 is 0.20 mm; the radius of curvature of the tenth mirror S10 is... The diameter is -10000.00mm, the mirror distance between the tenth mirror S10 and the eleventh mirror S11 is 1.00mm; the radius of curvature of the eleventh mirror S11 is 16.00mm, the mirror distance between the eleventh mirror S11 and the twelfth mirror S12 is 2.00mm; the radius of curvature of the twelfth mirror S12 is 34.00mm, and the mirror distance between the twelfth mirror S12 and the thirteenth mirror S13 is 0.80mm.

[0038] The radius of curvature of the thirteenth mirror surface S13 is 58.00 mm, and the mirror distance between the thirteenth mirror surface S13 and the fourteenth mirror surface S14 is 4.00 mm; the radius of curvature of the fourteenth mirror surface S14 is -14.00 mm, and the mirror distance between the fourteenth mirror surface S14 and the fifteenth mirror surface S15 is 1.00 mm; the radius of curvature of the fifteenth mirror surface S15 is -71.50 mm, and the mirror distance between the fifteenth mirror surface S15 and the sixteenth mirror surface S16 is 0.20 mm; the radius of curvature of the sixteenth mirror surface S16 is 110.00 mm. The mirror distance between the sixteenth mirror S16 and the seventeenth mirror S17 is 1.00 mm; the radius of curvature of the seventeenth mirror S17 is 15.00 mm; the mirror distance between the seventeenth mirror S17 and the eighteenth mirror S18 is 4.00 mm; the radius of curvature of the eighteenth mirror S18 is -41.00 mm; the mirror distance between the eighteenth mirror S18 and the nineteenth mirror S19 is 0.20 mm; the radius of curvature of the nineteenth mirror S19 is 25.00 mm; the mirror distance between the nineteenth mirror S19 and the twentieth mirror S20 is... The distance between the twentieth mirror S20 and the twenty-first mirror S21 is 3.80mm; the radius of curvature of the twentieth mirror S20 is -18.00mm, and the mirror distance between the twentieth mirror S20 and the twenty-first mirror S21 is 1.00mm; the radius of curvature of the twenty-first mirror S21 is 18.00mm, and the mirror distance between the twenty-first mirror S21 and the twenty-second mirror S22 is 1.90mm; the radius of curvature of the twenty-second mirror S22 is 15.50mm, and the mirror distance between the twenty-second mirror S22 and the twenty-third mirror S23 is 21.00mm; the distance between the twenty-third mirror S20 and the twenty-third mirror S21 is 3.80mm; the radius of curvature of the twenty-first mirror S20 is -18.00mm, and the mirror distance between the twenty-first mirror S21 and the twenty-second mirror S22 is 1.90mm; the radius of curvature of the twenty-second mirror S22 is 15.50mm, and the mirror distance between the twenty-second mirror S22 and the twenty-third mirror S23 is 21.00mm; the distance between the twenty-third mirror S20 and the twenty-third mirror S21 is 3.80mm, and the mirror distance between the twenty-second mirror S20 and the twenty-third mirror S22 is 18.00mm, and the mirror distance between the twenty-second mirror S21 ... The radius of curvature of mirror S23 is 6.20 mm, and the mirror distance between mirror S23 and mirror S24 is 1.30 mm; the radius of curvature of mirror S24 is -38.50 mm, and the mirror distance between mirror S24 and mirror S25 is 1.30 mm; the radius of curvature of mirror S25 is -6.80 mm, and the mirror distance between mirror S25 and mirror S26 is 1.00 mm; the radius of curvature of mirror S26 is 10.50 mm.

[0039] Table 2 By referring to the specific parameters and structures of each lens in Tables 1 and 2 above, the microscope objective can be configured to have a magnification of -50x, an image-square field of view of 28.5mm, a numerical aperture of 0.55, and a compatible tube lens focal length of 200mm. This embodiment of the microscope objective improves image quality while providing a higher image-square field of view than conventional objectives, and is entirely custom-designed, solving the problem that existing 50x objectives cannot be well matched with semiconductor measurement equipment.

[0040] In a preferred embodiment, the microscope objective may further include an aperture stop AS, disposed on the image-facing side of the fifth lens group G5. The aperture stop AS limits the aperture through which the light beam passes. Since the aperture stop AS is planar, its radius of curvature is infinite. Furthermore, the mirror distance from the aperture stop AS to the twenty-second mirror surface S22 can be 26.00 mm. It should also be noted that, since the object surface is planar, its radius of curvature is infinite. Furthermore, the mirror distance from the object surface to the first mirror surface S1 can be 10 mm. The mirror distance between the twenty-sixth mirror surface S26 and the image plane is infinite.

[0041] Figure 2 This is a full-field, full-wavelength dot plot of a microscope objective lens according to an embodiment of the present invention. Figure 2 The focusing of light with wavelengths from 0.4 μm to 0.7 μm (e.g., wavelengths of 0.486133 μm, 0.587562 μm, 0.656273 μm, 0.4 μm, 0.7 μm, 0.46 μm, 0.43 μm, and 0.445 μm) at the focal point is shown under different image plane fields of view. The object plane half-field of view of field of view (1) is 0 mm, the object plane half-field of view of field of view (2) is 0.18 mm, and the object plane half-field of view of field of view (3) is 0.285 mm. The test data are as follows: the Airy disk radius (diffraction limit) is 102.707 μm, the RMS radius (root mean square) at field of view (1) is 40.327 μm, the RMS radius at field of view (2) is 42.894 μm, and the RMS radius at field of view (3) is 54.036 μm.

[0042] The RMS radius, also known as the root mean square spot radius, is a key indicator used to describe the size of a focused spot. It is calculated by taking the square root of the second average of the intensity distribution of the spot on the image plane, and objectively reflects the degree of spot dispersion. Figure 2 It can be seen that the RMS radii of light of different wavelengths in different fields of view are all within the Airy disk range, indicating that the microscope objective of this embodiment has excellent focusing effect. The RMS radii in the dot plot are all better than the diffraction limit, and the aberrations are well controlled.

[0043] Figure 3 This is a lateral aberration diagram of a microscope objective lens according to an embodiment of the present invention. Figure 3 In the diagram, the horizontal coordinates Px and Py represent the entrance pupil position, and 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 3The diagram shows the lateral aberrations of light of different wavelengths at different entrance pupil positions when the image plane field of view is 0 mm, 0.18 mm, and 0.285 mm. The image plane fields of view corresponding to fields of view (1), (2), and (3) are 0 mm, 0.18 mm, and 0.285 mm, respectively. Figure 3 As shown, with image plane field of view of 0mm, 0.18mm and 0.285mm, the lateral aberrations of light with wavelengths of 0.486, 0.588, 0.656, 0.400, 0.700, 0.460, 0.430 and 0.445 at different entrance pupil positions are all within ±1mrad, indicating that the aberration balance is very good and the imaging is excellent.

[0044] Figure 4 This is a full-field transfer function curve of a microscope objective lens according to an embodiment of the present invention. Figure 4 The vertical axis represents the magnitude of the optical transfer function (OTF), and the horizontal axis represents the angular frequency. The outermost line is the transfer function curve of the system under diffraction-limited conditions. For example... Figure 4 As shown, the transfer function curves of the microscope objective lens in this embodiment, with image plane fields of view of 0mm, 0.18mm and 0.285mm, for each wavelength meridional plane and sagittal plane, indicate 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 optical system has high imaging contrast across the entire field of view and distinct imaging layers.

[0045] Figure 5 This is an axial aberration diagram of a microscope objective lens according to an embodiment of the present invention. Figure 5 The ordinate represents the normalized pupil coordinates, and the abscissa represents the axial aberration, in mm. Figure 5 The diagram shows the axial aberrations of light of different wavelengths at the same pupil radius. (Example:) Figure 5 As shown, the axial aberrations at each wavelength are all less than 0.003 mm, satisfying the requirement that the axial chromatic aberration at each entrance pupil position for any two wavelengths reaches the apochromatic level. It should be noted that axial aberration can also be referred to as longitudinal aberration, axial chromatic aberration, or longitudinal chromatic aberration.

[0046] Figure 6 This is a transverse chromatic aberration diagram of a microscope objective lens according to an embodiment of the present invention at a maximum field of view of 0.2850 mm. Figure 6 The vertical axis represents the field of view in mm, and the horizontal axis represents the lateral aberration in μm. Figure 6 The diagram shows the transverse chromatic aberration of light of different wavelengths at a maximum field of view of 0.2850 mm, where the maximum field of view of 0.2850 mm refers to the object plane half field of view. Figure 6 The vertical dashed lines on both sides represent the size of the diffraction-limited Airy disk of the system, such as... Figure 6 As shown, the transverse chromatic aberration of light of different wavelengths at a maximum field of view of 0.2850 mm remains within the size of the system's diffraction-limited Airy disk, indicating good control of the transverse chromatic aberration.

[0047] Figure 7 This is a field curvature distortion diagram of a microscope objective lens according to an embodiment of the present invention. Figure 7 The left side of the graph is the field curvature diagram, with the vertical axis representing the field of view in the direction of the incident light from the objective lens, and the horizontal axis representing the field curvature value in μm. Figure 7 The right-hand side of the graph shows the distortion plot. The vertical axis represents the image-side field of view during imaging, and the horizontal axis represents the distortion percentage. The data obtained when testing the field curvature plot are as follows: maximum field of view 0.285 mm, sagittal field curvature 0.0364 mm, meridional field curvature 0.0079 mm. The data obtained when testing the distortion plot are as follows: maximum field of view 0.285 mm, maximum distortion 1.0538%. (The text repeats itself here.) Figure 7 As shown, the field curvature values ​​in both the meridional and sagittal planes at each wavelength are below 0.04 mm, resulting in clear imaging across the entire field of view without introducing additional field curvature. The distortion across the entire field of view at each wavelength is within 1.1%, indicating good distortion correction.

[0048] This embodiment also provides a microscope, which includes the microscope objectives of any of the above embodiments. In a specific embodiment, by setting the specific parameters and structure of each lens, the microscope objective has a magnification of -50x, a field of view higher than that of a conventional commercial 50x microscope objective, an object-side field of view diameter of 0.57mm, and an image-side field of view diameter of 28.5mm when using a 200mm focal length tube. The working distance is 10mm, and the corresponding numerical aperture (NA) is relatively large at 0.55, achieving apochromatic aberration in the 400nm-700nm visible light band. It effectively corrects spherical aberration, coma, astigmatism, field curvature, distortion, axial chromatic aberration, and transverse chromatic aberration, meeting the requirements of a plan-field apochromatic objective.

[0049] Those skilled in the art should understand that, unless otherwise specified, the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," "circumferential," "clockwise," and "counterclockwise" used to indicate orientation or positional relationships in the embodiments of this utility model are merely for the convenience of describing and understanding the technical solution of this utility model, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0050] The terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," etc., may explicitly or implicitly include at least one of that feature, that is, include one or more of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. When a feature "includes or contains" one or more of the features it encompasses, unless otherwise specifically described, this indicates that other features are not excluded and may be further included.

[0051] Unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art should be able to understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0052] Furthermore, in the description of this embodiment, "above" or "below" the second feature can include direct contact between the first and second features, or it can include contact between the first and second features through another feature between them. That is, in the description of this embodiment, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "below" of the second feature can mean the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0053] In the description of this embodiment, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0054] Therefore, those skilled in the art should recognize that although many exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of 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 such other variations or modifications.

Claims

1. A microscope objective lens, characterized in that, include: The first lens, second lens, third lens, first lens group, second lens group, third lens group, fourth lens group, fifth lens group, fourteenth lens, and sixth lens group are arranged coaxially from the object side to the image side. The first lens has a concave surface facing the object and a convex surface facing the image; the second lens has a concave surface facing the object and a convex surface facing the image; the third lens has a concave surface facing the object and a convex surface facing the image; the fourteenth lens has a convex surface facing the object and a concave surface facing the image. The first lens group, the second lens group, the third lens group, the fourth lens group, the fifth lens group, and the sixth lens group each include at least two lenses, and the at least two lenses in each lens group have different refractive indices; The first lens group has a convex surface facing the object and a convex surface facing the image. The second lens group has a concave surface facing the object and a concave surface facing the image. The third lens group has a convex surface facing both the object and image sides; the fourth lens group has a convex surface facing both the object and image sides; the fifth lens group has a convex surface facing both the object and image sides; and the sixth lens group has a concave surface facing both the object and image sides.

2. The microscope objective according to claim 1, characterized in that, 39.5<fL1 / f<42.5, 172.5<fL2 / f<175.5, 34.5<fL3 / f<37.5, 43.5<fG1 / f<46.5, -46.5<fG2 / f<-43.5, 63 .5<fG3 / f<66.5, 92.5<fG4 / f<95.5, -85.5<fG5 / f<-81.5, -201.5<fL14 / f<-198.5, -49.5<fG6 / f<-45.5, Where fL1 is the focal length of the first lens, fL2 is the focal length of the second lens, fL3 is the focal length of the third 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, fL14 is the focal length of the fourteenth lens, fG6 is the focal length of the sixth 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, the second lens, and the third lens are all positive meniscus lenses with positive optical power; The first lens group is a cemented doublet with positive optical power, including a fourth lens and a fifth lens starting from the object side; the fourth lens is convex when facing the object side and convex when facing the image side; the fifth lens is concave when facing the object side and convex when facing the image side. The second lens group is a cemented doublet with negative optical power, including a sixth lens and a seventh lens starting from the object side; the sixth lens has a concave surface facing the object side and a concave surface facing the image side; the seventh lens has a convex surface facing the object side and a concave surface facing the image side. The third lens group is a cemented doublet with positive optical power, including an eighth lens and a ninth lens starting from the object side; the eighth lens is convex when facing the object side and convex when facing the image side; the ninth lens is concave when facing the object side and convex when facing the image side. The fourth lens group is a cemented doublet with positive optical power, including a tenth lens and an eleventh lens starting from the object side; the tenth lens has a convex surface facing the object side and a concave surface facing the image side; the eleventh lens has a convex surface facing both the object side and the image side. The fifth lens group is a cemented doublet with negative optical power, including a twelfth lens and a thirteenth lens starting from the object side; the twelfth lens has a convex surface facing the object side and a convex surface facing the image side; the thirteenth lens has a concave surface facing the object side and a concave surface facing the image side. The fourteenth lens is a negative meniscus lens with negative optical power; The sixth lens group is a cemented doublet 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 convex surface facing the image side; the sixteenth lens has a concave surface facing the object side and a concave surface facing the image side.

4. The microscope objective according to claim 3, characterized in that, The third lens, the fourth lens, the eighth lens, the eleventh lens, the twelfth lens, and the sixteenth lens all satisfy the following conditions: 1.40≤nd≤1.60, 66≤Vd≤96, 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 first lens, the second lens, the fifth lens, the sixth lens, the seventh lens, the ninth lens, the tenth lens, the thirteenth lens, the fourteenth lens, and the fifteenth lens all satisfy the following conditions: 1.60≤nd≤1.85, 24≤Vd≤57, where 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 according to claim 4, characterized in that, The first lens has a refractive index of 1.70 and an Abbe number of 30.00; The second lens has a refractive index of 1.62 and an Abbe number of 35.

92. The third lens has a refractive index of 1.44 and an Abbe number of 94.

55. The fourth lens has a refractive index of 1.44 and an Abbe number of 94.

50. The fifth lens has a refractive index of 1.60 and an Abbe number of 38.

00. The sixth lens has a refractive index of 1.79 and an Abbe number of 47.

48. The seventh lens has a refractive index of 1.81 and an Abbe number of 25.

38. The eighth lens has a refractive index of 1.58 and an Abbe number of 68.

30. The refractive index of the ninth lens is 1.64, and the Abbe number is 35.

39. The tenth lens has a refractive index of 1.67 and an Abbe number of 32.

19. The eleventh lens has a refractive index of 1.55 and an Abbe number of 75.

23. The twelfth lens has a refractive index of 1.57 and an Abbe number of 71.

30. The thirteenth lens has a refractive index of 1.61 and an Abbe number of 44.

10. The fourteenth lens has a refractive index of 1.68 and an Abbe number of 55.

52. The refractive index of the fifteenth lens is 1.80, and the Abbe number is 34.

97. The sixteenth lens has a refractive index of 1.50 and an Abbe number of 81.

61.

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

7. The microscope objective according to claim 6, characterized in that, The radius of curvature of the first mirror is -10.00 mm, and the mirror distance between the first mirror and the second mirror is 2.20 mm. The radius of curvature of the second mirror is -8.20 mm, and the mirror distance between the second mirror and the third mirror is 0.20 mm. The radius of curvature of the third mirror is -22.00 mm, and the mirror distance between the third mirror and the fourth mirror is 1.30 mm. The radius of curvature of the fourth mirror is -18.80 mm, and the mirror distance between the fourth mirror and the fifth mirror is 0.20 mm. The radius of curvature of the fifth mirror is -145.50 mm, and the mirror distance between the fifth mirror and the sixth mirror is 3.00 mm. The radius of curvature of the sixth mirror is -15.00 mm, and the mirror distance between the sixth mirror and the seventh mirror is 0.20 mm. The radius of curvature of the seventh mirror is 64.00 mm, and the mirror distance between the seventh mirror and the eighth mirror is 3.80 mm. The radius of curvature of the eighth mirror is -16.00 mm, and the mirror distance between the eighth mirror and the ninth mirror is 1.00 mm. The radius of curvature of the ninth mirror is -23.00 mm, and the mirror distance between the ninth mirror and the tenth mirror is 0.20 mm. The radius of curvature of the tenth mirror is -10000.00mm, and the mirror distance between the tenth mirror and the eleventh mirror is 1.00mm; The radius of curvature of the eleventh mirror is 16.00 mm, and the mirror distance between the eleventh mirror and the twelfth mirror is 2.00 mm. The radius of curvature of the twelfth mirror is 34.00 mm, and the mirror distance between the twelfth mirror and the thirteenth mirror is 0.80 mm. The radius of curvature of the thirteenth mirror is 58.00 mm, and the mirror distance between the thirteenth mirror and the fourteenth mirror is 4.00 mm. The radius of curvature of the fourteenth mirror is -14.00 mm, and the mirror distance between the fourteenth mirror and the fifteenth mirror is 1.00 mm. The radius of curvature of the fifteenth mirror is -71.50 mm, and the mirror distance between the fifteenth mirror and the sixteenth mirror is 0.20 mm. The radius of curvature of the sixteenth mirror is 110.00 mm, and the mirror distance between the sixteenth mirror and the seventeenth mirror is 1.00 mm. The radius of curvature of the seventeenth mirror is 15.00 mm, and the mirror distance between the seventeenth mirror and the eighteenth mirror is 4.00 mm. The radius of curvature of the eighteenth mirror is -41.00 mm, and the mirror distance between the eighteenth mirror and the nineteenth mirror is 0.20 mm. The radius of curvature of the nineteenth mirror is 25.00 mm, and the mirror distance between the nineteenth mirror and the twentieth mirror is 3.80 mm. The radius of curvature of the twentieth mirror is -18.00 mm, and the mirror distance between the twentieth and twentieth mirrors is 1.00 mm. The radius of curvature of the 21st mirror is 18.00 mm, and the mirror distance between the 21st mirror and the 22nd mirror is 1.90 mm. The radius of curvature of the 22nd mirror is 15.50 mm, and the mirror distance between the 22nd and 23rd mirrors is 21.00 mm. The radius of curvature of the 23rd mirror is 6.20 mm, and the mirror distance between the 23rd and 24th mirrors is 1.30 mm. The radius of curvature of the 24th mirror is -38.50mm, and the mirror distance between the 24th and 25th mirrors is 1.30mm. The radius of curvature of the 25th mirror is -6.80mm, and the mirror distance between the 25th and 26th mirrors is 1.00mm. The radius of curvature of the 26th mirror is 10.50 mm.

8. The microscope objective according to claim 7, characterized in that, The microscope objectives are used with tube lenses with a focal length of 200 mm.

9. The microscope objective according to claim 7, characterized in that, Also includes: An aperture stop is disposed on the image-facing side of the fifth lens group; The distance between the aperture stop and the twentieth mirror is 26.00 mm.

10. A microscope, characterized in that, Includes the microscope objective as described in any one of claims 1 to 9.

Images