Microscope objective optical system

Abstract

The invention discloses a microscope objective optical system, and relates to the technical field of optical instruments, the microscope objective optical system comprises a first lens group, a second lens group and a third lens group, the three lens groups are arranged, 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. Meanwhile, the respective composition of the first lens group, the second lens group and the third lens group is limited, and the respective focal distances are limited and meet preset conditions. Based on the above design, the microscope objective lens optical system has the advantages of long working distance, large aperture, high resolution, good imaging performance under broadband, and good correction of chromatic aberration.

Description

Technical Field

[0001] This application relates to the technical field of optical instruments, and particularly to a microscope objective optical system. Background Art

[0002] In the field of microscope technology, the microscope, as a key scientific instrument, is widely used in multiple fields such as biology, materials science, and medical research. It magnifies the image of a tiny object through an optical system, enabling researchers to observe details that are invisible to the naked eye. The performance of a microscope mainly depends on the quality of its objective lens and the magnification of the objective lens. A single optical microscope usually has multiple objective lenses with different magnifications (such as 10×, 40×, 60×, 100×, etc.) to switch objective lenses with different magnifications according to different observation requirements.

[0003] The objective lens of an optical microscope can adopt a planapochromat objective lens, which can not only accurately correct chromatic aberration for red, green, and blue light, but also correct field curvature, enabling the image within the entire field of view to be clearly presented. For example, Chinese Patent Document CN113485001A discloses a planapochromat microscope objective lens and an optical system. However, the optical system disclosed in this patent document is limited by insufficient system design. At a magnification of 60, the numerical aperture is 1.3, and the working distance is 0.17 mm, suffering from the technical deficiencies of insufficiently large numerical aperture, insufficiently high resolution, and insufficiently long working distance.

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

[0006] To achieve the above technical purpose, this application provides a microscope objective optical system, which includes 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 that are coaxially arranged in sequence from the object side to the image side;

[0007] The first lens group includes at least two a lens units, the a lens unit has positive refractive power and is an i lens or an i cemented lens, where 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. The b lens unit has a positive refractive power and is a j cemented lens, and the c lens unit has a negative refractive power and is a j cemented lens, where the j cemented 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 a negative refractive power and is a k lens, and the f lens unit has a positive refractive power and is a k lens or a k cemented lens, where the k cemented lens is composed of at least two k lenses;

[0010] The microscope objective optical system satisfies 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 length of the microscope objective optical system, fG1 is the focal length of the first lens group, fG2 is the focal length of the second lens group, fG12 is the focal length from the first lens group to the second lens group, and fG3 is the focal length of the third lens group.

[0016] Further, 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 overall optical length of the microscope objective optical system.

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

[0021] Further, the first i lens and the second i lens in the first lens group in the object side to image side direction satisfy the following conditions:

[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 of the first i-lens, RL2 is the radius of curvature of the image side of the second i-lens, and f1 is the focal length of the i-cemented lens formed by combining 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 Abbe number vd > 65.

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

[0027] -10 < f31 < 0

[0028] Wherein, f31 is the focal length of the k-lens 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 length 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 in sequence 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 length is 6.2 mm;

[0033] Or, the focal length 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 in sequence 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 length is 7.3 mm;

[0034] Or, the focal length 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 in sequence 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 length is 6.1 mm.

[0035] Further, the focal length of the second lens group is 23.7 mm. It 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, which are arranged in sequence 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 length is 83.4 mm; the fourth j-lens and the fifth j-lens are combined to form the j cemented lens, and the focal length is -1050 mm; the seventh j-lens and the eighth j-lens are combined to form the j cemented lens, and the focal length is -33.4 mm;

[0036] Alternatively, the focal length of the second lens group is 36.1 mm. It 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, which are arranged in sequence 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 length 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 length is -45.1 mm; the eighth j-lens and the ninth j-lens are combined to form the j cemented lens, and the focal length is -49.4 mm;

[0037] Alternatively, the focal length of the second lens group is 19.8 mm. It 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, which are arranged in sequence 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 length 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 length is -117 mm; the eighth j-lens and the ninth j-lens are combined to form the j cemented lens, and the focal length is -24.3 mm.

[0038] Further, the focal length 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 in sequence from the object side to the image side; the second k-lens and the third k-lens are combined to form the k-glued lens, and the focal length is 34.11 mm;

[0039] Alternatively, the focal length 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 in sequence from the object side to the image side;

[0040] Alternatively, the focal length of the third lens group is -38 mm, 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 in sequence 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-glued lens, and the focal length is 16.4 mm.

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

[0042] The first lens group, the second lens group, and the third lens group are designed and arranged, and 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. At the same time, the compositions of the first lens group, the second lens group, and the third lens group are defined respectively, and their respective focal lengths are defined and meet the preset conditions. Based on the above design, the microscope objective optical system has a long working distance, a large aperture, high resolution, good imaging performance in a wide wavelength band, and good chromatic aberration correction. Description of the Drawings

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0044] Figure 1 It is a schematic structural diagram of Application Example 1 of the microscope objective optical system provided in the present application;

[0045] Figure 2 It is a spherical aberration diagram of Application Example 1 of the microscope objective optical system provided in the present application;

[0046] Figure 3 This is the field curvature diagram of Application Example 1 of the microscope objective optical system provided in this application;

[0047] Figure 4 This is the distortion diagram of Application Example 1 of the microscope objective optical system provided in this application;

[0048] Figure 5 This is the structural schematic diagram of Application Example 2 of the microscope objective optical system provided in this application;

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

[0050] Figure 7 This is the field curvature diagram of Application Example 2 of the microscope objective optical system provided in this application;

[0051] Figure 8 This is the distortion diagram of Application Example 2 of the microscope objective optical system provided in this application;

[0052] Figure 9 This is the structural schematic diagram of Application Example 3 of the microscope objective optical system provided in this application;

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

[0054] Figure 11 This is the field curvature diagram of Application Example 3 of the microscope objective optical system provided in this application;

[0055] Figure 12 This is the distortion diagram of Application Example 3 of the microscope objective optical system provided in this application;

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

[0057] The technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the scope of protection of the embodiments of the present application.

[0058] In the description of the embodiments of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the embodiments of the present application. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and should not be construed as indicating or implying relative importance.

[0059] In the description of the embodiments of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a replaceable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be directly connected or indirectly connected through an intermediate medium. It can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific situations.

[0060] The embodiments of the present application disclose a microscope objective optical system.

[0061] Please refer to Figure 1 , an embodiment of the microscope objective optical system provided in the embodiments of the present 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, which are sequentially arranged coaxially along the object side to the image side.

[0063] The first lens group G1 includes at least two a lens units. The a lens unit has positive refractive power and is an i lens or an i cemented lens, where the i cemented lens is composed of at least two i lenses; it can be understood that the first lens group G1 has two or more than three lens units, and 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. The b lens unit has a positive refractive power and is a j cemented lens, and the c lens unit has a negative refractive power and is a j cemented lens, where the j cemented lens is composed of at least two j lenses; it can be understood that the second lens group G2 has two or more than three lens units, where 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 includes 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 a negative refractive power and is a k lens, and the f lens unit has a positive refractive power and is a k lens or a k cemented lens, where the k cemented lens is composed of at least two k lenses; it can be understood that the third lens group G3 has two or more than three lens units, where 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 includes at least two single lenses.

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

[0067] The microscope objective optical system satisfies 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] Wherein, f is the focal length of the microscope objective optical system, fG1 is the focal length of the first lens group G1, fG2 is the focal length of the second lens group G2, fG12 is the focal length from the first lens group G1 to the second lens group G2, and fG3 is the focal length of the third lens group G3.

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

[0074] The first lens group G1, the second lens group G2, and the third lens group G3 are designed and arranged such that the first lens group G1 has a positive refractive power, the second lens group G2 has a positive refractive power, and the third lens group G3 has a negative refractive power. At the same time, the compositions of the first lens group G1, the second lens group G2, and the third lens group G3 are defined respectively, and their respective focal lengths are defined and meet preset conditions. Based on the above design, the microscope objective optical system has a long working distance, a large aperture, high resolution, good imaging performance in a wide wavelength band, and good correction of chromatic aberration.

[0075] The above is the first embodiment of the microscope objective optical system provided by this application. The following is the second embodiment of the microscope objective optical system provided by this application. For details, please refer to Figures 1 to 12 。

[0076] Based on the solution of the above first embodiment:

[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] 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 overall optical length of the microscope objective optical system (i.e., 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 a positive refractive power and a refractive index N > 1.75.

[0082] The first i-lens 11 and the second i-lens 12 in the first lens group G1 in the object side to image side direction meet the following conditions:

[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 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 length of the i-glued lens formed by combining the first i-lens 11 and the second i-lens 12.

[0086] At least two j-lenses in the second lens group G2 have a 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 length of the k-th lens 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-th 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 lenses in the first lens group G1; the Abbe number of the lenses in the second lens group G2; and the focal length and refractive index of the third lens group G3, it helps to better achieve a large numerical aperture, ensure a long working distance, and improve the chromatic aberration correction ability in the entire visible light band (especially the chromatic aberration correction ability in the 400nm - 1000nm band), while having good flat field performance, small distortion, and high resolution.

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

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

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

[0097] Furthermore, the focal length of the second lens group G2 is 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, which are sequentially arranged 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 j-cemented lens with a focal length of 83.4 mm; the fourth j-lens 24 and the fifth j-lens 25 are combined to form a j-cemented lens with a focal length of -1050 mm; the seventh j-lens 27 and the eighth j-lens 28 are combined to form a j-cemented lens with a focal length of -33.4 mm;

[0098] Alternatively, the focal length of the second lens group G2 is 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, which are sequentially arranged 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 j-cemented lens with a focal length 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 j-cemented lens with a focal length of -45.1 mm; the eighth j-lens 28 and the ninth j-lens 29 are combined to form a j-cemented lens with a focal length of -49.4 mm;

[0099] Alternatively, the focal length of the second lens group G2 is 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, which are arranged in sequence 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 j cemented lens with a focal length 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 j cemented lens with a focal length of -117 mm; the eighth j lens 28 and the ninth j lens 29 are combined to form a j cemented lens with a focal length of -24.3 mm.

[0100] Furthermore, the focal length of the third lens group G3 is -31.8 mm. 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 in sequence 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 cemented lens with a focal length of 34.11 mm;

[0101] Alternatively, the focal length of the third lens group G3 is -23.3 mm. It 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, which are arranged in sequence from the object side to the image side;

[0102] Alternatively, the focal length of the third lens group G3 is -38 mm. 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 in sequence 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 cemented lens with a focal length of 16.4 mm.

[0103] The design of a specific application example one of the microscope objective optical system designed in this application is as follows:

[0104] The numerical aperture NA of the object side of the microscope objective optical system is 1.42, the object side field of view is 0.417 mm, the focal length f is 3 mm, the working distance is 0.18 mm, and the magnification is 60X.

[0105] As 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 (the side close to the object) and the image side (the side close to the image) of each i-lens, j-lens, and k-lens are as shown in Table 1 below:

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

[0108] Table 1

[0109]

[0110] The conditional values of Application 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 = 24.3 mm

[0122] V21 = 70.4, f21 = 13.5 mm

[0123] V25 = 70.4, f25 = 13.2 mm

[0124] V26 = 70.4, f26 = 40.6 mm

[0125] According to the above parameter design, the focal length of the first lens group G1 is 3.9 mm, which includes the first i-lens 11 with positive refractive power, the second i-lens 12 with positive refractive power, the third i-lens 13 with positive refractive power, and the fourth i-lens 14 with positive refractive power, which are sequentially arranged in the object side to image side direction; the first i-lens 11 and the second i-lens 12 are combined to form an i-cemented lens, and the focal length is 6.2 mm.

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

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

[0128] Figure 2It is the spherical aberration diagram of the microscope objective optical system in Application Example 1. The abscissa is the spherical aberration amount, with the unit of mm, and the ordinate is the normalized field of view, with the maximum value of 1. The solid line represents 644 nm, the dot line represents 546 nm, the dashed line represents 480 nm, and the dotted line represents 436 nm. It can be seen from the distribution of spherical aberration that the spherical aberration of the microscope objective optical system designed in this 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 relatively high resolution at the center of the image.

[0129] Figure 3 It is the field curvature diagram of the microscope objective optical system in Application Example 1. The abscissa is the object plane offset amount, with the unit of mm, and the ordinate is the normalized field of view, with the maximum value of 1. The solid line represents the meridional plane of the light ray, and the dashed line represents the sagittal plane of the light ray. It can be seen from the distribution of field curvature that the field curvature of this large numerical aperture and large field of view objective optical system is controlled within ±0.5 mm, indicating that the microscope objective optical system designed in this application has very good flatness of the field.

[0130] Figure 4 It is the distortion diagram of the microscope objective optical system in Application Example 1. The abscissa is the distortion amount, with the unit of %, and the ordinate is the normalized field of view, with the maximum value of 1. It can be seen from the distribution of distortion 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] The design of a specific Application Example 2 of the microscope objective optical system designed in this application is as follows:

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

[0133] As Figure 5 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 of each i-lens, j-lens, and k-lens are as shown in Table 2 below:

[0135] In the following table, the surface 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, 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, S332 is the image side surface of the third k-lens 33.

[0136] Table 2

[0137]

[0138] The conditional values of Application 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 = 25.0 mm

[0150] V21 = 70.4, f21 = 14.1 mm

[0151] V25 = 70.4, f25 = 19.2 mm

[0152] V27 = 71.3, f27 = 26.9 mm

[0153] V28 = 68.3, f28 = 7.4 mm

[0154] According to the above parameter design, the focal length 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, which are sequentially arranged in the object side to image side direction; the first i-lens 11 and the second i-lens 12 are combined to form an i-cemented lens, and the focal length is 7.3 mm.

[0155] The focal length of the second lens group G2 is 36.1 mm, which 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, which are sequentially arranged in the object side to image side direction; the first j-lens 21, the second j-lens 22, and the third j-lens 23 are combined to form a j-cemented lens, and the focal length is 87.5 mm; the fourth j-lens 24, the fifth j-lens 25, and the sixth j-lens 26 are combined to form a j-cemented lens, and the focal length is -45.1 mm; the eighth j-lens 28 and the ninth j-lens 29 are combined to form a j-cemented lens, and the focal length is -49.4 mm.

[0156] The focal length of the third lens group G3 is -23.3 mm, 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, which are sequentially arranged in the object side to image side direction.

[0157] Figure 6It is the spherical aberration diagram of the microscope objective optical system in Application Example 2. The abscissa is the spherical aberration amount, with the unit of mm, and the ordinate is the normalized field of view, with the maximum value of 1. The solid line represents 644 nm, the dot line represents 546 nm, the dashed line represents 480 nm, and the dotted line represents 436 nm. It can be seen from the distribution of spherical aberration that the spherical aberration of this microscope objective optical system is controlled within ±3 mm, indicating that the designed microscope objective optical system of this application has good axial chromatic aberration and a relatively high resolution at the center of the image.

[0158] Figure 7 It is the field curvature diagram of the microscope objective optical system in Application Example 2. The abscissa is the object plane offset amount, with the unit of mm, and the ordinate is the normalized field of view, with the maximum value of 1. The solid line represents the meridional plane of the light ray, and the dashed line represents the sagittal plane of the light ray. It can be seen from the distribution of field curvature that the field curvature of this large numerical aperture and large field of view objective optical system is controlled within ±1 mm, indicating that the designed microscope objective optical system of this application has very good flatness of the field.

[0159] Figure 8 It is the distortion diagram of the microscope objective optical system in Application Example 2. The abscissa is the distortion amount, with the unit of %, and the ordinate is the normalized field of view, with the maximum value of 1. It can be seen from the distribution of distortion that the distortion of this microscope objective optical system is controlled within ±1%, indicating that the designed microscope objective optical system of this application has relatively small distortion.

[0160] The design of a specific Application Example 3 of the designed microscope objective optical system of this application is as follows:

[0161] The object space numerical aperture NA of the microscope objective optical system is 1.43, the object space field of view is 0.417 mm, the focal length f is 3 mm, the working distance is 0.18 mm, and the magnification is 60X.

[0162] As Figure 9 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 of each i-lens, j-lens, and k-lens are as shown in Table 3 below:

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

[0165] Table 3

[0166]

[0167] The conditional values of Application Example 3 are as follows:

[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 = 19.6 mm

[0179] V21 = 70.4, f21 = 15.3 mm

[0180] V25 = 70.4, f25 = 8.1 mm

[0181] V27 = 71.3, f27 = 31.9 mm

[0182] According to the above parameter design, the focal length 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, which are sequentially arranged 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 length is 6.1 mm.

[0183] The focal length of the second lens group G2 is 19.8 mm, which 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, which are sequentially arranged 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 j-cemented lens, and the focal length is 40.5 mm; the fourth j-lens 24, the fifth j-lens 25, and the sixth j-lens 26 are combined to form a j-cemented lens, and the focal length is -117 mm; the eighth j-lens 28 and the ninth j-lens 29 are combined to form a j-cemented lens, and the focal length is -24.3 mm.

[0184] The focal length of the third lens group G3 is -38 mm, 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, which are sequentially arranged 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-cemented lens, and the focal length is 16.4 mm.

[0185] Figure 10It is the spherical aberration diagram of the microscope objective optical system in Application Example 3. The abscissa is the spherical aberration amount in mm, and the ordinate is the normalized field of view with a maximum of 1. The solid line represents 644 nm, the dotted line represents 546 nm, the dashed line represents 480 nm, and the dash-dotted line represents 436 nm. From the distribution of spherical aberration, it can be seen 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 a relatively high resolution at the center of the image.

[0186] Figure 11 It is the field curvature diagram of the microscope objective optical system in Application Example 3. The abscissa is the object plane offset in mm, and the ordinate is the normalized field of view with a maximum of 1. The solid line represents the meridional plane of the light ray, and the dashed line represents the sagittal plane of the light ray. From the distribution of field curvature, it can be seen that the field curvature of this large numerical aperture and large field of view objective optical system is controlled within ±1 mm, indicating that the microscope objective optical system designed in this application has very good flatness.

[0187] Figure 12 It is the distortion diagram of the microscope objective optical system in Application Example 3. The abscissa is the distortion amount in %, and the ordinate is the normalized field of view with a maximum of 1. From the distribution of distortion, it can be seen 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] Through the above three specific application examples, it can be proved that the microscope objective optical system designed in this application can achieve a large numerical aperture, ensure a long working distance, and correct chromatic aberration in the entire visible light band. At the same time, it has the advantages of good flatness, small distortion, and high resolution.

[0189] The above has introduced the microscope objective optical system provided in this application in detail. For those of ordinary skill in the art, according to the idea of the embodiments of this application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to this application.

Claims

1. Microscope objective optical system, characterized in that, It includes 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, which are arranged coaxially in sequence from the object side to the image side; The first lens group (G1) includes at least two a lens units, the a lens units have positive refractive power and are i lenses or i cemented lenses, and the i cemented lenses are composed of at least two i lenses; The second lens group (G2) includes at least one b lens unit and at least one c lens unit, the b lens unit has positive refractive power and is a j cemented lens, the c lens unit has negative refractive power and is a j cemented lens, and the j cemented lens is composed of at least two j lenses; 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, the f lens unit has positive refractive power and is a k lens or a k cemented lens, and the k cemented lens is composed of at least two k lenses; The microscope objective optical system satisfies 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 length of the microscope objective optical system, fG1 is the focal length of the first lens group (G1), fG2 is the focal length of the second lens group (G2), fG12 is the focal length from the first lens group (G1) to the second lens group (G2), and fG3 is the focal length of the third lens group (G3).

2. The microscope objective optical system according to claim 1, wherein The microscope objective optical system also satisfies 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 overall 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, wherein The first i lens (11) and the second i lens (12) in the first lens group (G1) in the direction from the object side to the image side 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 length of the i cemented lens formed by combining 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, wherein The third lens group (G3) satisfies the following conditions: -10 < f31 < 0 Wherein, f31 is the focal length of the k-th lens 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-th lens closest to the image side.

8. The microscope objective optical system according to claim 1, characterized in that, The focal length 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, which are sequentially arranged in the object side to image side direction; the first i-lens (11) and the second i-lens (12) are combined to form the i-cemented lens, and the focal length is 6.2 mm; Or, the focal length 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, which are sequentially arranged in the object side to image side direction; the first i-lens (11) and the second i-lens (12) are combined to form the i-cemented lens, and the focal length is 7.3 mm; Or, the focal length 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, which are sequentially arranged in the object side to image side direction; the first i-lens (11) and the second i-lens (12) are combined to form the i-cemented lens, and the focal length is 6.1 mm.

9. The microscope objective optical system according to claim 1, characterized in that, The focal length of the second lens group (G2) is 23.7 mm, which 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, which are sequentially arranged in the object side to image side direction; the first j-lens (21), the second j-lens (22), and the third j-lens (23) are combined to form the j-cemented lens, and the focal length is 83.4 mm; the fourth j-lens (24) and the fifth j-lens (25) are combined to form the j-cemented lens, and the focal length is -1050 mm; the seventh j-lens (27) and the eighth j-lens (28) are combined to form the j-cemented lens, and the focal length is -33.4 mm; Alternatively, the focal length of the second lens group (G2) is 36.1 mm, which 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, which are arranged in sequence 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 the j cemented lens, and the focal length is 87.5 mm; the fourth j-lens (24), the fifth j-lens (25), and the sixth j-lens (26) are combined to form the j cemented lens, and the focal length is -45.1 mm; the eighth j-lens (28) and the ninth j-lens (29) are combined to form the j cemented lens, and the focal length is -49.4 mm; Alternatively, the focal length of the second lens group (G2) is 19.8 mm, which 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, which are arranged in sequence 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 the j cemented lens, and the focal length is 40.5 mm; the fourth j-lens (24), the fifth j-lens (25), and the sixth j-lens (26) are combined to form the j cemented lens, and the focal length is -117 mm; the eighth j-lens (28) and the ninth j-lens (29) are combined to form the j cemented lens, and the focal length is -24.3 mm.

10. The microscope objective optical system according to claim 1, characterized in that, The focal length of the third lens group (G3) is -31.8 mm, 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, which are arranged in sequence from the object side to the image side; the second k-lens (32) and the third k-lens (33) are combined to form the k cemented lens, and the focal length is 34.11 mm; Alternatively, the focal length of the third lens group (G3) is -23.3 mm, 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, which are sequentially arranged from the object side to the image side; Alternatively, the focal length of the third lens group (G3) is -38 mm, 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, which are sequentially arranged 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 the k-glued lens, and the focal length is 16.4 mm.

Images