Microscope objective optical system

Abstract

This application discloses a microscope objective optical system, relating to the field of optical instrument technology. The system includes a first lens group, a second lens group, and a third lens group. The three lens groups are configured such that the first lens group has positive refractive power, the second lens group has positive refractive power, and the third lens group has negative refractive power. Furthermore, the composition of each of the first, second, and third lens groups is defined, and their focal distances are defined and satisfy preset conditions. Based on this design, the microscope objective optical system has a long working distance, large aperture, high resolution, good imaging performance over a wide wavelength range, and well-corrected chromatic aberration.

Description

Technical Field

[0001] This application relates to the field of optical instrument technology, and in particular to microscope objective optical systems. Background Technology

[0002] In the field of microscopy, the microscope, as a crucial scientific instrument, is widely used in various fields such as biology, materials science, and medical research. It magnifies images of tiny objects through an optical system, allowing researchers to observe details invisible to the naked eye. The performance of a microscope primarily depends on the quality and magnification of its objectives. A single optical microscope typically has multiple objectives with different magnifications (e.g., 10×, 40×, 60×, 100×, etc.) to allow for switching between objectives with different magnifications according to different observation needs.

[0003] Optical microscope objectives can employ plan apochromatic objectives. These objectives can precisely correct chromatic aberration in red, green, and blue light, and also correct field curvature, ensuring clear image representation across the entire field of view. For example, Chinese patent document CN113485001A discloses a plan apochromatic microscope objective and optical system. However, the optical system disclosed in this patent document is limited by its design shortcomings. At 60x magnification, the numerical aperture is 1.3, and the working distance is 0.17mm, exhibiting technical deficiencies such as insufficient numerical aperture, insufficient resolution, and insufficient working distance.

[0004] Therefore, there is an urgent need to provide an improved solution to overcome the above-mentioned technical deficiencies, improve numerical aperture and resolution, and increase working distance to meet the needs of a wider range of scientific research and industrial applications. Summary of the Invention

[0005] In view of this, the purpose of this application is to provide a microscope objective optical system that improves numerical aperture and resolution while increasing working distance to meet the needs of a wider range of scientific and industrial applications.

[0006] To achieve the above-mentioned technical objectives, this application provides a microscope objective optical system, including a first lens group with positive refractive power, a second lens group with positive refractive power, and a third lens group with negative refractive power arranged sequentially and coaxially along the object side to the image side.

[0007] The first lens group includes at least two a-lens units, each a-lens unit having positive refractive power and being an i-lens or an i-cemented lens, wherein the i-cemented lens is composed of at least two i-lenses;

[0008] The second lens group includes at least one b lens unit and at least one c lens unit, wherein the b lens unit has positive refractive power and is a j-crystal lens, and the c lens unit has negative refractive power and is a j-crystal lens, wherein the j-crystal lens is composed of at least two j lenses;

[0009] The third lens group includes at least one d lens unit and at least one f lens unit. The d lens unit has negative refractive power and is a k lens. The f lens unit has positive refractive power and is a k lens or a k-cemented lens, wherein the k-cemented lens is composed of at least two of the k lenses.

[0010] The microscope objective optical system meets the following conditions:

[0011] 1.1 < fG1 / f < 1.6

[0012] 5.5 < fG2 / f < 14

[0013] 0.9 < f / fG12 < 1.5

[0014] -14 < fG3 / f < -6

[0015] Wherein, f is the focal distance of the microscope objective optical system, fG1 is the focal distance of the first lens group, fG2 is the focal distance of the second lens group, fG12 is the focal distance from the first lens group to the second lens group, and fG3 is the focal distance of the third lens group.

[0016] Furthermore, the microscope objective optical system also satisfies the following conditions:

[0017] 0.01 < d1 / L < 0.04

[0018] 0.02 < d² / L < 0.05

[0019] Wherein, d1 is the distance from the first lens group to the second lens group, d2 is the distance from the second lens group to the third lens group, and L is the total optical length of the microscope objective optical system.

[0020] Furthermore, at least one of the i-lenses in the first lens group has positive refractive power and a refractive index N > 1.75.

[0021] Furthermore, the first i-lens and the second i-lens in the first lens group, in the object-to-image direction, satisfy the following condition:

[0022] -0.4 <RL1 / f1<-0.2

[0023] -0.7 <RL2 / f1<-0.5

[0024] Wherein, RL1 is the radius of curvature of the image side surface of the first i-lens, RL2 is the radius of curvature of the image side surface of the second i-lens, and f1 is the focal distance of the i-cemented lens formed by the combination of the first i-lens and the second i-lens.

[0025] Furthermore, at least two of the j lenses in the second lens group have positive refractive power and an Abbe number vd > 65.

[0026] Furthermore, the third lens group satisfies the following condition:

[0027] -10 < f31 < 0

[0028] Wherein, f31 is the focal distance of the k lens, which is closest to the object side in the third lens group.

[0029] Furthermore, the third lens group also satisfies the following conditions:

[0030] NLe > 1.72

[0031] Wherein, NLe is the refractive index of the k-lens closest to the image side.

[0032] Furthermore, the focal distance of the first lens group is 3.9 mm, and it includes a first i-lens with positive refractive power, a second i-lens with positive refractive power, a third i-lens with positive refractive power, and a fourth i-lens with positive refractive power arranged sequentially from the object side to the image side; the first i-lens and the second i-lens are combined to form the i-cemented lens, and the focal distance is 6.2 mm;

[0033] Alternatively, the focal distance of the first lens group is 4.2 mm, which includes a first i-lens with positive refractive power, a second i-lens with positive refractive power, a third i-lens with positive refractive power, and a fourth i-lens with positive refractive power arranged sequentially from the object side to the image side; the first i-lens and the second i-lens are combined to form the i-cemented lens, and the focal distance is 7.3 mm;

[0034] Alternatively, the focal distance of the first lens group is 3.9 mm, which includes a first i-lens with positive refractive power, a second i-lens with positive refractive power, a third i-lens with positive refractive power, and a fourth i-lens with positive refractive power arranged sequentially in the direction from the object side to the image side; the first i-lens and the second i-lens are combined to form the i-cemented lens, and the focal distance is 6.1 mm.

[0035] Furthermore, the second lens group has a focal distance of 23.7 mm, and includes a first j lens with positive refractive power, a second j lens with negative refractive power, a third j lens with positive refractive power, a fourth j lens with negative refractive power, a fifth j lens with positive refractive power, a sixth j lens with positive refractive power, a seventh j lens with positive refractive power, and an eighth j lens with negative refractive power, arranged sequentially from the object side to the image side. The first j lens, the second j lens, and the third j lens are combined to form the j-cemented lens, and the focal distance is 83.4 mm. The fourth j lens and the fifth j lens are combined to form the j-cemented lens, and the focal distance is -1050 mm. The seventh j lens and the eighth j lens are combined to form the j-cemented lens, and the focal distance is -33.4 mm.

[0036] Alternatively, the second lens group has a focal distance of 36.1 mm and includes a first j lens with positive refractive power, a second j lens with negative refractive power, a third j lens with positive refractive power, a fourth j lens with negative refractive power, a fifth j lens with positive refractive power, a sixth j lens with negative refractive power, a seventh j lens with positive refractive power, an eighth j lens with positive refractive power, and a ninth j lens with negative refractive power, arranged sequentially from the object side to the image side. The first j lens, the second j lens, and the third j lens are combined to form the j-cemented lens, and the focal distance is 87.5 mm. The fourth j lens, the fifth j lens, and the sixth j lens are combined to form the j-cemented lens, and the focal distance is -45.1 mm. The eighth j lens and the ninth j lens are combined to form the j-cemented lens, and the focal distance is -49.4 mm.

[0037] Alternatively, the second lens group has a focal distance of 19.8 mm and includes a first j lens with positive refractive power, a second j lens with negative refractive power, a third j lens with positive refractive power, a fourth j lens with negative refractive power, a fifth j lens with positive refractive power, a sixth j lens with negative refractive power, a seventh j lens with positive refractive power, an eighth j lens with positive refractive power, and a ninth j lens with negative refractive power, arranged sequentially from the object side to the image side. The first j lens, the second j lens, and the third j lens are combined to form the j-cemented lens, and the focal distance is 40.5 mm. The fourth j lens, the fifth j lens, and the sixth j lens are combined to form the j-cemented lens, and the focal distance is -117 mm. The eighth j lens and the ninth j lens are combined to form the j-cemented lens, and the focal distance is -24.3 mm.

[0038] Furthermore, the focal distance of the third lens group is -31.8 mm, which includes a first k lens with negative refractive power, a second k lens with negative refractive power, a third k lens with positive refractive power, and a fourth k lens with positive refractive power arranged sequentially from the object side to the image side; the second k lens and the third k lens are combined to form the k-cemented lens, and the focal distance is 34.11 mm;

[0039] Alternatively, the focal distance of the third lens group is -23.3 mm, which includes a first k lens with negative refractive power, a second k lens with negative refractive power, and a third k lens with positive refractive power arranged sequentially from the object side to the image side.

[0040] Alternatively, the focal distance of the third lens group is -38mm, which includes a first k-lens with negative refractive power, a second k-lens with positive refractive power, a third k-lens with negative refractive power, and a fourth k-lens with positive refractive power arranged sequentially from the object side to the image side; the second k-lens, the third k-lens, and the fourth k-lens are combined to form the k-cemented lens, and the focal distance is 16.4mm.

[0041] As can be seen from the above technical solutions, the microscope objective optical system designed in this application has the following beneficial effects:

[0042] The microscope objective optical system is designed with a first lens group, a second lens group, and a third lens group, each possessing positive and negative refractive power. The composition of each lens group is defined, as are their focal distances, and these limitations are satisfied with predetermined conditions. Based on this design, the microscope objective optical system exhibits a long working distance, large aperture, high resolution, excellent imaging performance across a wide wavelength range, and well-corrected chromatic aberration. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a schematic diagram of the structure of an application example of the microscope objective optical system provided in this application;

[0045] Figure 2 A spherical aberration diagram for an application example of the microscope objective optical system provided in this application;

[0046] Figure 3 Field curve diagram for an application example of the microscope objective optical system provided in this application;

[0047] Figure 4 Distortion diagram of an application example of the microscope objective optical system provided in this application;

[0048] Figure 5 This is a schematic diagram of the structure of the microscope objective optical system provided in this application, as shown in Example 2.

[0049] Figure 6 A spherical aberration diagram for Example 2 of the application of the microscope objective optical system provided in this application;

[0050] Figure 7 Field curve diagram for Example 2 of the application of the microscope objective optical system provided in this application;

[0051] Figure 8 Distortion diagram of Example 2 of the application of the microscope objective optical system provided in this application;

[0052] Figure 9 This is a schematic diagram of the structure of the microscope objective optical system provided in this application, Example 3.

[0053] Figure 10 A spherical aberration diagram for Example 3 of the application of the microscope objective optical system provided in this application;

[0054] Figure 11 Field curve diagram for Example 3 of the application of the microscope objective optical system provided in this application;

[0055] Figure 12 Distortion diagram of Example 3 of the application of the microscope objective optical system provided in this application;

[0056] In the diagram: 11, first i-lens; 12, second i-lens; 13, third i-lens; 14, fourth i-lens; 21, first j-lens; 22, second j-lens; 23, third j-lens; 24, fourth j-lens; 25, fifth j-lens; 26, sixth j-lens; 27, seventh j-lens; 28, eighth j-lens; 29, ninth j-lens; 31, first k-lens; 32, second k-lens; 33, third k-lens; 34, fourth k-lens; G1, first lens group; G2, second lens group; G3, third lens group. Detailed Implementation

[0057] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the embodiments of this application.

[0058] In the description of the embodiments of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0059] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a replaceable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0060] This application discloses an optical system for microscope objectives.

[0061] Please see Figure 1 One embodiment of the microscope objective optical system provided in this application includes:

[0062] A first lens group G1 with positive refractive power, a second lens group G2 with positive refractive power, and a third lens group G3 with negative refractive power are arranged sequentially along the optical axis from the object side to the image side.

[0063] The first lens group G1 includes at least two a lens units, each a lens unit having positive refractive power and being an i lens or an i-ceramic lens, wherein the i-ceramic lens is composed of at least two i lenses; it is understood that the first lens group G1 has two or more lens units, wherein the lens unit can be a single lens or a cemented lens formed by combining at least two single lenses; in terms of the number of lenses, the first lens group G1 contains at least two single lenses.

[0064] The second lens group G2 includes at least one b lens unit and at least one c lens unit, wherein the b lens unit has positive refractive power and is a j-crystal lens, and the c lens unit has negative refractive power and is a j-crystal lens, wherein the j-crystal lens is composed of at least two j lenses; it can be understood that the second lens group G2 has two or more lens units, wherein at least one lens unit is a cemented lens, and at least another lens unit is a single lens or a cemented lens; in terms of the number of lenses, the second lens group G2 contains at least three single lenses.

[0065] The third lens group G3 includes at least one d lens unit and at least one f lens unit. The d lens unit has negative refractive power and is a k lens, and the f lens unit has positive refractive power and is a k lens or a k-ceramic lens, wherein the k-ceramic lens is composed of at least two k lenses. It can be understood that the third lens group G3 has two or more lens units, wherein at least one lens unit is a single lens, and at least another lens unit is a single lens or a cemented lens. In terms of the number of lenses, the third lens group G3 contains at least two single lenses.

[0066] It should be noted that the lens units in different lens groups in this application are given different letter prefixes, and the corresponding lenses / cemented lenses are also given different letter prefixes. This is not to represent a specific type of lens, but to more clearly illustrate the structural composition of different lens groups.

[0067] The microscope objective optical system must meet the following conditions:

[0068] 1.1 < fG1 / f < 1.6

[0069] 5.5 < fG2 / f < 14

[0070] 0.9 < f / fG12 < 1.5

[0071] -14 < fG3 / f < -6

[0072] Where f is the focal distance of the microscope objective optical system, fG1 is the focal distance of the first lens group G1, fG2 is the focal distance of the second lens group G2, fG12 is the focal distance from the first lens group G1 to the second lens group G2, and fG3 is the focal distance of the third lens group G3.

[0073] The microscope objective optical system designed in this application has the following beneficial effects:

[0074] The microscope objective optical system is designed with a first lens group G1, a second lens group G2, and a third lens group G3, each possessing positive and negative refractive power. The composition of each lens group is defined, as are their focal distances, and these limitations are satisfied with predetermined conditions. Based on this design, the microscope objective optical system exhibits a long working distance, large aperture, high resolution, excellent imaging performance across a wide wavelength range, and well-corrected chromatic aberration.

[0075] The above is Embodiment 1 of the microscope objective optical system provided in this application. The following is Embodiment 2 of the microscope objective optical system provided in this application. Please refer to the following for details. Figures 1 to 12 .

[0076] Based on the solution of Embodiment 1 above:

[0077] Furthermore, the microscope objective optical system also meets the following conditions:

[0078] 0.01 < d1 / L < 0.04

[0079] 0.02 < d² / L < 0.05

[0080] Where d1 is the distance from the first lens group G1 to the second lens group G2, d2 is the distance from the second lens group G2 to the third lens group G3, and L is the total optical length of the microscope objective optical system (that is, the distance from the object side of the first lens to the image side of the last lens).

[0081] Furthermore, at least one i-lens in the first lens group G1 has positive refractive power and a refractive index N > 1.75.

[0082] In the first lens group G1, the first i-lens 11 and the second i-lens 12 in the object-to-image direction satisfy the following condition:

[0083] -0.4 <RL1 / f1<-0.2

[0084] -0.7 <RL2 / f1<-0.5

[0085] Wherein, RL1 is the radius of curvature of the image side surface of the first i-lens 11, RL2 is the radius of curvature of the image side surface of the second i-lens 12, and f1 is the focal distance of the i-cemented lens formed by the combination of the first i-lens 11 and the second i-lens 12.

[0086] At least two j lenses in the second lens group G2 have positive refractive power and an Abbe number vd > 65.

[0087] The third lens group G3 satisfies the following conditions:

[0088] -10 < f31 < 0

[0089] Where f31 is the focal distance of the k lens, which is closest to the object side in the third lens group G3.

[0090] The third lens group G3 also satisfies the following conditions:

[0091] NLe > 1.72

[0092] Where NLe is the refractive index of the k-lens closest to the image side.

[0093] By setting the distances between the first lens group G1, the second lens group G2, and the third lens group G3, especially the refractive index and surface radius of the lens in the first lens group G1; the Abbe number of the lens in the second lens group G2; and the focal distance and refractive index of the third lens group G3, it is helpful to better achieve a large numerical aperture, ensure a longer working distance, and improve the chromatic aberration correction capability across the entire visible light spectrum (especially the chromatic aberration correction capability in the 400nm~1000nm band), while also possessing good flatness, low distortion, and high resolution.

[0094] Furthermore, the focal distance of the first lens group G1 is 3.9 mm, which includes a first i-lens 11 with positive refractive power, a second i-lens 12 with positive refractive power, a third i-lens 13 with positive refractive power, and a fourth i-lens 14 with positive refractive power arranged sequentially from the object side to the image side; the first i-lens 11 and the second i-lens 12 are combined to form an i-cemented lens, and the focal distance is 6.2 mm;

[0095] Alternatively, the focal distance of the first lens group G1 is 4.2 mm, which includes a first i-lens 11 with positive refractive power, a second i-lens 12 with positive refractive power, a third i-lens 13 with positive refractive power, and a fourth i-lens 14 with positive refractive power arranged sequentially from the object side to the image side; the first i-lens 11 and the second i-lens 12 are combined to form an i-cemented lens, and the focal distance is 7.3 mm;

[0096] Alternatively, the focal distance of the first lens group G1 is 3.9 mm, which includes a first i-lens 11 with positive refractive power, a second i-lens 12 with positive refractive power, a third i-lens 13 with positive refractive power and a fourth i-lens 14 with positive refractive power arranged sequentially in the direction from the object side to the image side; the first i-lens 11 and the second i-lens 12 are combined to form an i-cemented lens, and the focal distance is 6.1 mm.

[0097] Furthermore, the second lens group G2 has a focal distance of 23.7 mm, and includes a first j lens 21 with positive refractive power, a second j lens 22 with negative refractive power, a third j lens 23 with positive refractive power, a fourth j lens 24 with negative refractive power, a fifth j lens 25 with positive refractive power, a sixth j lens 26 with positive refractive power, a seventh j lens 27 with positive refractive power, and an eighth j lens 28 with negative refractive power, arranged sequentially from the object side to the image side. The first j lens 21, the second j lens 22, and the third j lens 23 are combined to form a cemented j lens with a focal distance of 83.4 mm; the fourth j lens 24 and the fifth j lens 25 are combined to form a cemented j lens with a focal distance of -1050 mm; and the seventh j lens 27 and the eighth j lens 28 are combined to form a cemented j lens with a focal distance of -33.4 mm.

[0098] Alternatively, the second lens group G2 has a focal distance of 36.1 mm, and includes a first j lens 21 with positive refractive power, a second j lens 22 with negative refractive power, a third j lens 23 with positive refractive power, a fourth j lens 24 with negative refractive power, a fifth j lens 25 with positive refractive power, a sixth j lens 26 with negative refractive power, a seventh j lens 27 with positive refractive power, an eighth j lens 28 with positive refractive power, and a ninth j lens 29 with negative refractive power, arranged sequentially from the object side to the image side; the first j lens 21, the second j lens 22, and the third j lens 23 combine to form a cemented j lens with a focal distance of 87.5 mm; the fourth j lens 24, the fifth j lens 25, and the sixth j lens 26 combine to form a cemented j lens with a focal distance of -45.1 mm; the eighth j lens 28 and the ninth j lens 29 combine to form a cemented j lens with a focal distance of -49.4 mm;

[0099] Alternatively, the second lens group G2 has a focal distance of 19.8 mm, and includes a first j lens 21 with positive refractive power, a second j lens 22 with negative refractive power, a third j lens 23 with positive refractive power, a fourth j lens 24 with negative refractive power, a fifth j lens 25 with positive refractive power, a sixth j lens 26 with negative refractive power, a seventh j lens 27 with positive refractive power, an eighth j lens 28 with positive refractive power, and a ninth j lens 29 with negative refractive power, arranged sequentially from the object side to the image side; the first j lens 21, the second j lens 22, and the third j lens 23 combine to form a cemented j lens with a focal distance of 40.5 mm; the fourth j lens 24, the fifth j lens 25, and the sixth j lens 26 combine to form a cemented j lens with a focal distance of -117 mm; the eighth j lens 28 and the ninth j lens 29 combine to form a cemented j lens with a focal distance of -24.3 mm.

[0100] Furthermore, the focal distance of the third lens group G3 is -31.8mm, which includes a first k lens 31 with negative refractive power, a second k lens 32 with negative refractive power, a third k lens 33 with positive refractive power, and a fourth k lens 34 with positive refractive power arranged sequentially from the object side to the image side; the second k lens 32 and the third k lens 33 are combined to form a k-cement lens, and the focal distance is 34.11mm;

[0101] Alternatively, the focal distance of the third lens group G3 is -23.3mm, which includes a first k lens 31 with negative refractive power, a second k lens 32 with negative refractive power, and a third k lens 33 with positive refractive power arranged sequentially from the object side to the image side.

[0102] Alternatively, the focal distance of the third lens group G3 is -38mm, which includes a first k lens 31 with negative refractive power, a second k lens 32 with positive refractive power, a third k lens 33 with negative refractive power, and a fourth k lens 34 with positive refractive power arranged sequentially from the object side to the image side; the second k lens 32, the third k lens 33, and the fourth k lens 34 are combined to form a k-cement lens, and the focal distance is 16.4mm.

[0103] A specific application example of the microscope objective optical system designed in this application is as follows:

[0104] The microscope objective optical system has an object-side numerical aperture (NA) of 1.42, an object-side field of view of 0.417 mm, a focal distance (f) of 3 mm, a working distance of 0.18 mm, and a magnification of 60X.

[0105] like Figure 1As shown, the microscope objective optical system includes a first lens group G1, a second lens group G2, and a third lens group G3.

[0106] The parameters of the object-side surface (the surface closer to the object) and image-side surface (the surface closer to the image) of each i-lens, j-lens, and k-lens are shown in Table 1 below:

[0107] In the table below, S111 is the object-side surface of the first i-lens 11, S121 is the object-side surface of the second i-lens 12, S122 is the image-side surface of the second i-lens 12, S131 is the object-side surface of the third i-lens 13, S132 is the image-side surface of the third i-lens 13, S141 is the object-side surface of the fourth i-lens 14, S142 is the image-side surface of the fourth i-lens 14, S211 is the object-side surface of the first j-lens 21, S221 is the object-side surface of the second j-lens 22, S231 is the object-side surface of the third j-lens 23, S232 is the image-side surface of the third j-lens 23, S241 is the object-side surface of the fourth j-lens 24, and S251 is the object-side surface of the fifth j-lens 25. S252 is the image-side surface of the fifth j lens 25, S261 is the object-side surface of the sixth j lens 26, S262 is the image-side surface of the sixth j lens 26, S271 is the object-side surface of the seventh j lens 27, S281 is the object-side surface of the eighth j lens 28, S282 is the image-side surface of the eighth j lens 28, S311 is the object-side surface of the first k lens 31, S312 is the image-side surface of the first k lens 31, S321 is the object-side surface of the second k lens 32, S331 is the object-side surface of the third k lens 33, S332 is the image-side surface of the third k lens 33, S341 is the object-side surface of the fourth k lens 34, and S342 is the image-side surface of the fourth k lens 34.

[0108] Table 1

[0109]

[0110] The conditional values ​​in Example 1 satisfy the following:

[0111] fG1 / f=1.3

[0112] fG2 / f=7.9

[0113] f / G12=1.35

[0114] fG3 / f=-10.6

[0115] d1 / L=0.03

[0116] d² / L = 0.04

[0117] RL1 / f1 = -0.3

[0118] RL2 / f1 = -0.58

[0119] f31=-5.1

[0120] NLe=1.74

[0121] N13=1.83, f13=24.3mm

[0122] V21=70.4, f21=13.5mm

[0123] V25=70.4, f25=13.2mm

[0124] V26=70.4, f26=40.6mm

[0125] Designed according to the above parameters, the focal distance of the first lens group G1 is 3.9mm, which includes a first i-lens 11 with positive refractive power, a second i-lens 12 with positive refractive power, a third i-lens 13 with positive refractive power, and a fourth i-lens 14 with positive refractive power arranged sequentially from the object side to the image side; the first i-lens 11 and the second i-lens 12 are combined to form an i-cemented lens, and the focal distance is 6.2mm.

[0126] The second lens group G2 has a focal distance of 23.7 mm. It includes a first j lens 21 with positive refractive power, a second j lens 22 with negative refractive power, a third j lens 23 with positive refractive power, a fourth j lens 24 with negative refractive power, a fifth j lens 25 with positive refractive power, a sixth j lens 26 with positive refractive power, a seventh j lens 27 with positive refractive power, and an eighth j lens 28 with negative refractive power, arranged sequentially from the object side to the image side. The first j lens 21, the second j lens 22, and the third j lens 23 are combined to form a cemented j lens with a focal distance of 83.4 mm. The fourth j lens 24 and the fifth j lens 25 are combined to form a cemented j lens with a focal distance of -1050 mm. The seventh j lens 27 and the eighth j lens 28 are combined to form a cemented j lens with a focal distance of -33.4 mm.

[0127] The focal distance of the third lens group G3 is -31.8mm. It includes a first k lens 31 with negative refractive power, a second k lens 32 with negative refractive power, a third k lens 33 with positive refractive power, and a fourth k lens 34 with positive refractive power, which are arranged sequentially from the object side to the image side. The second k lens 32 and the third k lens 33 are combined to form a k-cement lens, and the focal distance is 34.11mm.

[0128] Figure 2The diagram shows the spherical aberration of the microscope objective optical system in Application Example 1. The horizontal axis represents the spherical aberration in mm, and the vertical axis represents the normalized field of view, with a maximum value of 1. Solid lines represent 644 nm, dotted lines represent 546 nm, dashed lines represent 480 nm, and dotted lines represent 436 nm. The distribution of spherical aberration shows that the spherical aberration of the microscope objective optical system designed in Application Example 1 is controlled within ±3 mm, indicating that the microscope objective optical system designed in this application has good axial chromatic aberration and high resolution at the center of the image.

[0129] Figure 3 The image shows the field curvature of the microscope objective optical system in Application Example 1. The horizontal axis represents the object plane offset in mm, and the vertical axis represents the normalized field of view, with a maximum value of 1. Solid lines represent the meridional plane of light rays, and dashed lines represent the sagittal plane. The distribution of the field curvature shows that the field curvature of this large numerical aperture, large field-of-view objective optical system is controlled within ±0.5 mm, indicating that the microscope objective optical system designed in this application possesses excellent field flatness.

[0130] Figure 4 The image shows the distortion of the microscope objective optical system in Application Example 1. The horizontal axis represents the distortion amount in %, and the vertical axis represents the normalized field of view, with a maximum value of 1. The distortion distribution shows that the distortion of this microscope objective optical system is controlled within ±1%, indicating that the microscope objective optical system designed in this application has relatively small distortion.

[0131] A specific application example two of the microscope objective optical system designed in this application is as follows:

[0132] The microscope objective optical system has an object-side numerical aperture (NA) of 1.41 mm, an object-side field of view of 0.417 mm, a focal distance (f) of 3 mm, a working distance of 0.18 mm, and a magnification of 60X.

[0133] like Figure 5 As shown, the microscope objective optical system includes a first lens, a second lens group G2, and a third lens group G3.

[0134] The parameters of the object-side and image-side surfaces of each i-lens, j-lens, and k-lens are shown in Table 2 below:

[0135] In the table below, S111 is the object-side surface of the first i-lens 11, S121 is the object-side surface of the second i-lens 12, S122 is the image-side surface of the second i-lens 12, S131 is the object-side surface of the third i-lens 13, S132 is the image-side surface of the third i-lens 13, S141 is the object-side surface of the fourth i-lens 14, S142 is the image-side surface of the fourth i-lens 14, S211 is the object-side surface of the first j-lens 21, S221 is the object-side surface of the second j-lens 22, S231 is the object-side surface of the third j-lens 23, S232 is the image-side surface of the third j-lens 23, S241 is the object-side surface of the fourth j-lens 24, and S251 is the object-side surface of the fifth j-lens 25. S261 is the object-side surface of the sixth j lens 26, S262 is the image-side surface of the sixth j lens 26, S271 is the object-side surface of the seventh j lens 27, S272 is the image-side surface of the seventh j lens 27, S281 is the object-side surface of the eighth j lens 28, S291 is the object-side surface of the ninth j lens 29, S292 is the image-side surface of the ninth j lens 29, S311 is the object-side surface of the first k lens 31, S312 is the image-side surface of the first k lens 31, S321 is the object-side surface of the second k lens 32, S322 is the image-side surface of the second k lens 32, S331 is the object-side surface of the third k lens 33, and S332 is the image-side surface of the third k lens 33.

[0136] Table 2

[0137]

[0138] The numerical conditions in Example 2 satisfy the following:

[0139] fG1 / f=1.42

[0140] fG2 / f=12.2

[0141] f / G12=1.05

[0142] fG3 / f=-7.87

[0143] d1 / L=0.003

[0144] d² / L = 0.04

[0145] RL1 / f1=-0.23

[0146] RL2 / f1 = -0.56

[0147] f31 = -8.3

[0148] NLe=1.74

[0149] N13=1.83, f13=25.0mm

[0150] V21=70.4, f21=14.1mm

[0151] V25=70.4, f25=19.2mm

[0152] V27=71.3, f27=26.9mm

[0153] V28=68.3, f28=7.4mm

[0154] Designed according to the above parameters, the focal distance of the first lens group G1 is 4.2mm, which includes a first i-lens 11 with positive refractive power, a second i-lens 12 with positive refractive power, a third i-lens 13 with positive refractive power and a fourth i-lens 14 with positive refractive power arranged sequentially in the direction from the object side to the image side; the first i-lens 11 and the second i-lens 12 are combined to form an i-cemented lens, and the focal distance is 7.3mm.

[0155] The second lens group G2 has a focal distance of 36.1 mm. It includes a first j lens 21 with positive refractive power, a second j lens 22 with negative refractive power, a third j lens 23 with positive refractive power, a fourth j lens 24 with negative refractive power, a fifth j lens 25 with positive refractive power, a sixth j lens 26 with negative refractive power, a seventh j lens 27 with positive refractive power, an eighth j lens 28 with positive refractive power, and a ninth j lens 29 with negative refractive power, arranged sequentially from the object side to the image side. The first j lens 21, the second j lens 22, and the third j lens 23 are combined to form a cemented j lens with a focal distance of 87.5 mm. The fourth j lens 24, the fifth j lens 25, and the sixth j lens 26 are combined to form a cemented j lens with a focal distance of -45.1 mm. The eighth j lens 28 and the ninth j lens 29 are combined to form a cemented j lens with a focal distance of -49.4 mm.

[0156] The focal distance of the third lens group G3 is -23.3mm, which includes a first k lens 31 with negative refractive power, a second k lens 32 with negative refractive power, and a third k lens 33 with positive refractive power arranged sequentially from the object side to the image side.

[0157] Figure 6The image shows the spherical aberration of the microscope objective optical system in Application Example 2. The horizontal axis represents the spherical aberration in mm, and the vertical axis represents the normalized field of view, with a maximum value of 1. Solid lines represent 644 nm, dotted lines represent 546 nm, dashed lines represent 480 nm, and dotted lines represent 436 nm. The distribution of spherical aberration shows that the spherical aberration of this microscope objective optical system is controlled within ±3 mm, indicating that the microscope objective optical system designed in this application has good axial chromatic aberration and high resolution at the center of the image.

[0158] Figure 7 The image shows the field curvature of the microscope objective optical system in Application Example 2. The horizontal axis represents the object plane offset in mm, and the vertical axis represents the normalized field of view, with a maximum value of 1. Solid lines represent the meridional plane of light rays, and dashed lines represent the sagittal plane. The distribution of the field curvature shows that the field curvature of this large numerical aperture, large field-of-view objective optical system is controlled within ±1 mm, indicating that the microscope objective optical system designed in this application possesses excellent field flatness.

[0159] Figure 8 The image shows the distortion of the microscope objective optical system in Application Example 2. The horizontal axis represents the distortion amount in %, and the vertical axis represents the normalized field of view, with a maximum value of 1. The distortion distribution shows that the distortion of this microscope objective optical system is controlled within ±1%, indicating that the microscope objective optical system designed in this application has relatively small distortion.

[0160] A specific application example three of the microscope objective optical system designed in this application is as follows:

[0161] The microscope objective optical system has an object-side numerical aperture (NA) of 1.43, an object-side field of view of 0.417 mm, a focal distance (f) of 3 mm, a working distance of 0.18 mm, and a magnification of 60X.

[0162] like Figure 9 As shown, the microscope objective optical system includes a first lens, a second lens group G2, and a third lens group G3.

[0163] The parameters of the object-side and image-side surfaces of each i-lens, j-lens, and k-lens are shown in Table 3 below:

[0164] In the table below, S111 is the object-side surface of the first i-lens 11, S121 is the object-side surface of the second i-lens 12, S122 is the image-side surface of the second i-lens 12, S131 is the object-side surface of the third i-lens 13, S132 is the image-side surface of the third i-lens 13, S141 is the object-side surface of the fourth i-lens 14, S142 is the image-side surface of the fourth i-lens 14, S211 is the object-side surface of the first j-lens 21, S221 is the object-side surface of the second j-lens 22, S231 is the object-side surface of the third j-lens 23, S232 is the image-side surface of the third j-lens 23, S241 is the object-side surface of the fourth j-lens 24, and S251 is the object-side surface of the fifth j-lens 24. The object-side surface of lens 25 is S261, the object-side surface of lens 26 is S262, the image-side surface of lens 26 is S271, the object-side surface of lens 27 is S272, the image-side surface of lens 27 is S281, the object-side surface of lens 28 is S291, the object-side surface of lens 29 is S292, the image-side surface of lens 29 is S311, the object-side surface of lens 31 is S312, the image-side surface of lens 31 is S331, the object-side surface of lens 33 is S341, the object-side surface of lens 34 is S342, and the image-side surface of lens 34 is S342.

[0165] Table 3

[0166]

[0167] The numerical conditions in Example 3 satisfy the following:

[0168] fG1 / f=1.29

[0169] fG2 / f=6.53

[0170] f / G12=1.33

[0171] fG3 / f=-12.54

[0172] d1 / L=0.003

[0173] d² / L = 0.03

[0174] RL1 / f1=-0.35

[0175] RL2 / f1 = -0.61

[0176] f31=-6.0

[0177] NLe=1.83

[0178] N13=1.80, f13=19.6mm

[0179] V21=70.4, f21=15.3mm

[0180] V25=70.4, f25=8.1mm

[0181] V27=71.3, f27=31.9mm

[0182] Designed according to the above parameters, the focal distance of the first lens group G1 is 3.9mm, which includes a first i-lens 11 with positive refractive power, a second i-lens 12 with positive refractive power, a third i-lens 13 with positive refractive power and a fourth i-lens 14 with positive refractive power arranged sequentially from the object side to the image side; the first i-lens 11 and the second i-lens 12 are combined to form an i-cemented lens, and the focal distance is 6.1mm.

[0183] The second lens group G2 has a focal distance of 19.8 mm. It includes a first j lens 21 with positive refractive power, a second j lens 22 with negative refractive power, a third j lens 23 with positive refractive power, a fourth j lens 24 with negative refractive power, a fifth j lens 25 with positive refractive power, a sixth j lens 26 with negative refractive power, a seventh j lens 27 with positive refractive power, an eighth j lens 28 with positive refractive power, and a ninth j lens 29 with negative refractive power, arranged sequentially from the object side to the image side. The first j lens 21, the second j lens 22, and the third j lens 23 are combined to form a cemented j lens with a focal distance of 40.5 mm. The fourth j lens 24, the fifth j lens 25, and the sixth j lens 26 are combined to form a cemented j lens with a focal distance of -117 mm. The eighth j lens 28 and the ninth j lens 29 are combined to form a cemented j lens with a focal distance of -24.3 mm.

[0184] The focal distance of the third lens group G3 is -38mm. It includes a first k lens 31 with negative refractive power, a second k lens 32 with positive refractive power, a third k lens 33 with negative refractive power, and a fourth k lens 34 with positive refractive power, which are arranged sequentially from the object side to the image side. The second k lens 32, the third k lens 33, and the fourth k lens 34 are combined to form a k-cement lens, and the focal distance is 16.4mm.

[0185] Figure 10The image shows the spherical aberration of the microscope objective optical system in Application Example 3. The horizontal axis represents the spherical aberration in mm, and the vertical axis represents the normalized field of view, with a maximum value of 1. Solid lines represent 644 nm, dotted lines represent 546 nm, dashed lines represent 480 nm, and dotted lines represent 436 nm. The distribution of spherical aberration shows that the spherical aberration of this microscope objective optical system is controlled within ±2 mm, indicating that the microscope objective optical system designed in this application has good axial chromatic aberration and high resolution at the center of the image.

[0186] Figure 11 The image shows the field curvature of the microscope objective optical system in Application Example 3. The horizontal axis represents the object plane offset in mm, and the vertical axis represents the normalized field of view, with a maximum value of 1. Solid lines represent the meridional plane of light rays, and dashed lines represent the sagittal plane. The distribution of the field curvature shows that the field curvature of this large numerical aperture, large field-of-view objective optical system is controlled within ±1 mm, indicating that the microscope objective optical system designed in this application possesses excellent field flatness.

[0187] Figure 12 The image shows the distortion of the microscope objective optical system in Application Example 3. The horizontal axis represents the distortion amount in %, and the vertical axis represents the normalized field of view, with a maximum value of 1. The distortion distribution shows that the distortion of this microscope objective optical system is controlled within ±1%, indicating that the microscope objective optical system designed in this application has relatively small distortion.

[0188] The above three specific application examples demonstrate that the microscope objective optical system designed in this application can achieve a large numerical aperture, ensure a long working distance, and provide chromatic aberration correction across the entire visible light spectrum. It also possesses the advantages of good flatness, low distortion, and high resolution.

[0189] The microscope objective optical system provided in this application has been described in detail above. For those skilled in the art, there may be changes in the specific implementation and application scope based on the ideas of the embodiments of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A microscope objective optical system, characterized in that, It consists of a first lens group (G1) with positive refractive power, a second lens group (G2) with positive refractive power, and a third lens group (G3) with negative refractive power, arranged sequentially along the optical axis from the object side to the image side. The first lens group (G1) consists of a first i-lens (11) with positive refractive power, a second i-lens (12) with positive refractive power, a third i-lens (13) with positive refractive power, and a fourth i-lens (14) with positive refractive power arranged sequentially in the direction from the object side to the image side; the first i-lens (11) and the second i-lens (12) are combined to form an i-cement lens; The second lens group (G2) consists of a first j lens (21) with positive refractive power, a second j lens (22) with negative refractive power, a third j lens (23) with positive refractive power, a fourth j lens (24) with negative refractive power, a fifth j lens (25) with positive refractive power, a sixth j lens (26) with positive refractive power, a seventh j lens (27) with positive refractive power, and an eighth j lens (28) with negative refractive power, arranged sequentially from the object side to the image side. The first j lens (21), the second j lens (22), and the third j lens (23) are combined to form a cemented j lens; the fourth j lens (24) and the fifth j lens (25) are combined to form a cemented j lens; the seventh j lens (27) and the eighth j lens (28) are combined to form a cemented j lens; or arranged sequentially from the object side to the image side. The lens is composed of a first j lens (21) with positive refractive power, a second j lens (22) with negative refractive power, a third j lens (23) with positive refractive power, a fourth j lens (24) with negative refractive power, a fifth j lens (25) with positive refractive power, a sixth j lens (26) with negative refractive power, a seventh j lens (27) with positive refractive power, an eighth j lens (28) with positive refractive power, and a ninth j lens (29) with negative refractive power, arranged sequentially. The first j lens (21), the second j lens (22), and the third j lens (23) are combined to form a cemented j lens; the fourth j lens (24), the fifth j lens (25), and the sixth j lens (26) are combined to form a cemented j lens; and the eighth j lens (28) and the ninth j lens (29) are combined to form a cemented j lens. The third lens group (G3) consists of a first k-lens (31) with negative refractive power, a second k-lens (32) with negative refractive power, a third k-lens (33) with positive refractive power, and a fourth k-lens (34) with positive refractive power, arranged sequentially from the object side to the image side; the second k-lens (32) and the third k-lens (33) are combined to form a cemented k-lens; or it consists of a first k-lens (31) with negative refractive power, a second k-lens (32) with negative refractive power, and a third k-lens (33) with positive refractive power, arranged sequentially from the object side to the image side; or it consists of a first k-lens (31) with negative refractive power, a second k-lens (32) with positive refractive power, a third k-lens (33) with negative refractive power, and a fourth k-lens (34) with positive refractive power, arranged sequentially from the object side to the image side; the second k-lens (32), the third k-lens (33), and the fourth k-lens (34) are combined to form a cemented k-lens; The microscope objective optical system meets the following conditions: 1.1 < fG1 / f < 1.6 5.5 < fG2 / f < 14 0.9 < f / fG12 < 1.5 -14 < fG3 / f < -6 Wherein, f is the focal distance of the microscope objective optical system, fG1 is the focal distance of the first lens group (G1), fG2 is the focal distance of the second lens group (G2), fG12 is the focal distance from the first lens group (G1) to the second lens group (G2), and fG3 is the focal distance of the third lens group (G3).

2. The microscope objective optical system according to claim 1, characterized in that, The microscope objective optical system also meets the following conditions: 0.01 < d1 / L < 0.04 0.02 < d² / L < 0.05 Wherein, d1 is the distance from the first lens group (G1) to the second lens group (G2), d2 is the distance from the second lens group (G2) to the third lens group (G3), and L is the total optical length of the microscope objective optical system.

3. The microscope objective optical system according to claim 1, characterized in that, At least one of the i-lenses in the first lens group (G1) has positive refractive power and a refractive index N > 1.

75.

4. The microscope objective optical system according to claim 3, characterized in that, The first i-lens (11) and the second i-lens (12) in the first lens group (G1) in the object-to-image direction satisfy the following conditions: -0.4 <RL1 / f1<-0.2 -0.7 <RL2 / f1<-0.5 Wherein, RL1 is the radius of curvature of the image side of the first i-lens (11), RL2 is the radius of curvature of the image side of the second i-lens (12), and f1 is the focal distance of the i-cemented lens formed by the combination of the first i-lens (11) and the second i-lens (12).

5. The microscope objective optical system according to claim 1, characterized in that, At least two of the j lenses in the second lens group (G2) have positive refractive power and an Abbe number vd > 65.

6. The microscope objective optical system according to claim 1, characterized in that, The third lens group (G3) satisfies the following conditions: -10 < f31 < 0 Wherein, f31 is the focal distance of the k lens that is closest to the object side in the third lens group (G3).

7. The microscope objective optical system according to claim 6, characterized in that, The third lens group (G3) also satisfies the following conditions: NLe > 1.72 Wherein, NLe is the refractive index of the k-lens closest to the image side.

8. The microscope objective optical system according to claim 1, characterized in that, The focal distance of the first lens group (G1) is 3.9 mm and the focal distance of the i-cement lens is 6.2 mm; Alternatively, the focal distance of the first lens group (G1) is 4.2 mm and the focal distance of the i-cemented lens is 7.3 mm; Alternatively, the focal distance of the first lens group (G1) is 3.9 mm and the focal distance of the i-cement lens is 6.1 mm.

9. The microscope objective optical system according to claim 1, characterized in that, The focal distance of the second lens group (G2) is 23.7 mm, the focal distance of the cemented j lens formed by the combination of the second j lens (22) and the third j lens (23) is 83.4 mm, the focal distance of the cemented j lens formed by the combination of the fourth j lens (24) and the fifth j lens (25) is -1050 mm, and the focal distance of the cemented j lens formed by the combination of the seventh j lens (27) and the eighth j lens (28) is -33.4 mm; Alternatively, the focal distance of the second lens group (G2) is 36.1 mm, the focal distance of the cemented lens formed by the combination of the first j lens (21), the second j lens (22), and the third j lens (23) is 87.5 mm, the focal distance of the cemented lens formed by the combination of the fourth j lens (24), the fifth j lens (25), and the sixth j lens (26) is -45.1 mm, and the focal distance of the cemented lens formed by the combination of the eighth j lens (28) and the ninth j lens (29) is -49.4 mm; Alternatively, the focal distance of the second lens group (G2) is 19.8 mm, the focal distance of the cemented lens formed by the combination of the first j lens (21), the second j lens (22) and the third j lens (23) is 40.5 mm, the focal distance of the cemented lens formed by the combination of the fourth j lens (24), the fifth j lens (25) and the sixth j lens (26) is -117 mm, and the focal distance of the cemented lens formed by the combination of the eighth j lens (28) and the ninth j lens (29) is -24.3 mm.

10. The microscope objective optical system according to claim 1, characterized in that, The focal distance of the third lens group (G3) is -31.8 mm, and the focal distance of the cemented lens formed by the combination of the second k lens (32) and the third k lens (33) is 34.11 mm; Alternatively, the focal distance of the third lens group (G3) is -23.3 mm; Alternatively, the focal distance of the third lens group (G3) is -38mm, and the focal distance of the k-cemented lens formed by the combination of the second k-lens (32), the third k-lens (33), and the fourth k-lens (34) is 16.4mm.

Images