Microscope Objective Simulation Design Method and 20x Long Working Distance Microscope Objective

Abstract

The present invention discloses a method for simulating the design of a microscope objective lens and a 20x long working distance microscope objective lens. The design method includes: taking a microscope objective lens with a long working distance between 16 and 25 times as the target, designing one or more lens optical parameters such as the focal length, refractive index, radius of curvature, and dispersion coefficient of the lenses of the first optical sub-module, the second optical sub-module, and the third optical sub-module arranged in sequence along the optical axis, and simulating the corresponding MTF curves of different design schemes. By comparing the MTF curves corresponding to each design scheme, a better design scheme for the microscope objective lens is determined. The present invention can determine the parameters of the microscope objective lens that meet the requirements when the imaging quality index is close to the limit value under ideal conditions through simulation, and accordingly designs a 20x long working distance microscope objective lens, which has good resolution in the full field of view while satisfying the long working distance.

Description

Technical Field

[0001] The present invention relates to the field of physical optics, and in particular, to a method for simulating the design of a microscope objective lens and a 20x long working distance microscope objective lens. Background Art

[0002] As an important optical instrument for observing tiny objects, the microscope has a wide range of applications. With the continuous expansion of the application fields, the requirements for the microscope are getting higher and higher. In particular, it is required that the microscope objective lens has a long working distance and good high resolution at the same time. Generally speaking, when the working distance of the microscope objective lens is long, it is often difficult to obtain good optical resolution over the entire field of view; while the objective lens with better optical resolution often has a relatively small working distance, poor operability and process adaptability, and is inconvenient to use. Users can only select a more suitable objective lens according to the application requirements, rather than an objective lens that meets the usage requirements.

[0003] Therefore, it is an urgent problem to solve to have a microscope objective lens with a long working distance and good optical resolution over the entire field of view.

[0004] The disclosure of the above background art content is only used to assist in understanding the inventive concept and technical solution of the present invention. It does not necessarily belong to the prior art of this patent application, nor will it necessarily give technical guidance; in the case where there is no clear evidence indicating that the above content has been made public before the filing date of this patent application, the above background art should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0005] The object of the present invention is to provide a method for simulating the design of a microscope objective lens, and a microscope objective lens with a long working distance and good optical resolution over the entire field of view can be designed according to this method; and accordingly, a 20x long working distance microscope objective lens with good optical resolution is designed.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A method for simulating the design of a microscope objective lens includes the following steps:

[0008] Design a first optical sub-module, which includes a crescent positive lens, a first negative lens, and a first double convex lens arranged in sequence, wherein the concave surface of the first negative lens is attached to one of the convex surfaces of the first double convex lens;

[0009] Design a second optical sub-module, which includes at least one second negative lens and at least two second double convex lenses, and the convex surface of at least one of the second double convex lenses is attached to the concave surface of the second negative lens;

[0010] Design the third optical sub-module, which includes a positive lens and a first biconcave lens arranged in sequence, wherein the convex surface of the positive lens is attached to one of the concave surfaces of the first biconcave lens;

[0011] Arrange the first optical sub-module, the second optical sub-module, and the third optical sub-module along the optical axis in sequence, so that the concave surface of the crescent positive lens faces the object surface, the first biconvex lens is arranged adjacent to the second optical sub-module, and the second optical sub-module is arranged at a relatively spaced position relative to the positive lens of the third optical sub-module;

[0012] Taking a microscope objective lens with a magnification between 16 and 25 times the working distance as the target, design one or more lens optical parameters such as the focal length, refractive index, radius of curvature, and dispersion coefficient of the lenses of the first optical sub-module, the second optical sub-module, and the third optical sub-module, and simulate the MTF curves corresponding to different design schemes. Determine the optimal design scheme of the microscope objective lens by comparing the MTF curves corresponding to each design scheme.

[0013] Furthermore, design the second optical sub-module as follows:

[0014] The second optical sub-module includes two second biconvex lenses and a second biconcave lens, and the two second biconvex lenses are respectively attached to the concave surfaces on both sides of the second biconcave lens; or,

[0015] The second optical sub-module includes multiple groups of corresponding second biconvex lenses and second negative lenses, and the second biconvex lens and the second negative lens in the same group are glued to form an integral lens; or,

[0016] The second optical sub-module includes three second biconvex lenses and two second negative lenses, wherein two second biconvex lenses and two second negative lenses form glued lenses in a one-to-one correspondence, and at least one convex surface of the other second biconvex lens is arranged adjacent to the convex surface of the second biconvex lens in the glued lens; or,

[0017] The second optical sub-module includes two second biconvex lenses and a second negative lens, wherein one second biconvex lens and the second negative lens are glued to form an integral lens, the other second biconvex lens is arranged on the side closer to the object surface, and the two second biconvex lenses are arranged adjacent to each other;

[0018] The second optical sub-module includes three second biconvex lenses, a second biconcave lens, and a concave lens, wherein two second biconvex lenses are respectively attached to the second biconcave lens to form a glued lens, and the other second biconvex lens is attached to the concave lens to form another glued lens.

[0019] Continuing from any of the foregoing technical solutions or a combination of multiple technical solutions, further, the first negative lens and the first bi-convex lens of the first optical sub-module are cemented lenses, and the lens optical parameters of the first optical sub-module are designed as follows:

[0020] The dispersion coefficient V of the first bi-convex lens dp1 ≥ 78; and / or,

[0021] The combined focal length of the first optical sub-module satisfies the following relationship: 1.0 ≤ f1 / f ≤ 4.2, where f1 is the combined focal length of the first optical sub-module and f is the combined focal length of the microscope objective as a whole; and / or,

[0022] 1.3 ≤ R1 / f ≤ 5.2, where R1 is the radius of curvature of the cemented surface between the first negative lens and the first bi-convex lens, and f is the combined focal length of the microscope objective as a whole; and / or,

[0023] V dp1 -V dm1 ≥ 25, where V dp1 is the dispersion coefficient of the first bi-convex lens, and V dm1 is the dispersion coefficient of the first negative lens.

[0024] Continuing from any of the foregoing technical solutions or a combination of multiple technical solutions, further, the optical parameters of the crescent positive lens are designed as follows:

[0025] 1.6 ≤ f L1 / f ≤ 6.4, where f L1 is the focal length of the crescent positive lens and f is the combined focal length of the microscope objective as a whole;

[0026] 1.1 ≤ -R0 / d0 ≤ 4.6, where R0 is the radius of curvature of the concave surface of the crescent positive lens facing the object surface, and d0 is the distance from the object surface to the object-side mirror surface of the crescent positive lens;

[0027] 1.65 ≤ N0 ≤ 2.1, where N0 is the refractive index of the crescent positive lens.

[0028] Continuing from any of the foregoing technical solutions or a combination of multiple technical solutions, further, the lens optical parameters of the second optical sub-module are designed as follows:

[0029] The combined focal length of the second optical sub-module satisfies the following relationship: 2.0 ≤ f2 / f ≤ 8, where f2 is the combined focal length of the second optical sub-module and f is the combined focal length of the microscope objective as a whole; and / or,

[0030] The concave surface of the second negative lens facing the object surface is the cemented surface of the cemented lens. The outer surfaces of the lenses of the second optical sub-module close to the object surface are all convex surfaces. The radius of curvature R2 of the convex outer surface of the lens closest to the image side in the second optical sub-module satisfies the relation: 1.4 ≤ R2 / f ≤ 3.7, where f is the combined focal length of the microscope objective as a whole; and / or,

[0031] V dp2 -V dm2 ≥ 20, where V dp2 is the dispersion coefficient of the second biconvex lens, and V dm2 is the dispersion coefficient of the second negative lens; and / or,

[0032] N m2 –N p2 ≥ 0.06, where N m2 is the refractive index of the second negative lens, and N p2 is the refractive index of the second biconvex lens.

[0033] Continuing from any one of the above technical solutions or a combination of multiple technical solutions, further, the lens optical parameters of the second optical sub-module are designed as follows:

[0034] 1.1 ≤ f L2 / f ≤ 5.5, where f L2 is the focal length of the second biconvex lens of the second optical sub-module, and f is the combined focal length of the microscope objective as a whole;

[0035] The dispersion coefficient V of at least two second biconvex lenses dp2 ≥ 78.

[0036] Continuing from any one of the above technical solutions or a combination of multiple technical solutions, further, the positive lens of the third optical sub-module and the first biconcave lens are cemented lenses. The lens optical parameters of the third optical sub-module are designed as follows:

[0037] 0.98 ≤ -f3 / f ≤ 4, where f3 is the combined focal length of the third optical sub-module, and f is the combined focal length of the microscope objective as a whole; and / or,

[0038] 0.51 ≤ R3 / f ≤ 2.2, where R3 is the radius of curvature of the concave surface closest to the image side in the third optical sub-module, and f is the combined focal length of the microscope objective as a whole; and / or,

[0039] N p3 –N m3 ≥ 0.18, where N p3 is the refractive index of the positive lens of the third optical sub-module, and N m3 is the refractive index of the first biconcave lens; and / or,

[0040] V dm3 -V dp3 ≥12, where V dp3 is the dispersion coefficient of the positive lens of the third optical sub-module, and V dm3 is the dispersion coefficient of the first biconcave lens.

[0041] According to another aspect of the present invention, the present invention provides a 20X long working distance microscope objective lens, which is designed according to the microscope objective lens simulation design method described in any one of the above technical solutions or a combination of multiple technical solutions.

[0042] Furthermore, the focal lengths of the first optical sub-module, the second optical sub-module, and the third optical sub-module of the microscope objective lens satisfy the following relational expressions: 1.75 ≤ f1 / f ≤ 2.75, 3.65 ≤ f2 / f ≤ 4.75, 1.3 ≤ -f3 / f ≤ 2.5, where f1 is the combined focal length of the first optical sub-module, f2 is the combined focal length of the second optical sub-module, f3 is the combined focal length of the third optical sub-module, and f is the combined focal length of the entire microscope objective lens; and / or,

[0043] The dispersion coefficients of the lenses in the first optical sub-module, the second optical sub-module, and the third optical sub-module satisfy the following relational expressions: V dp1 -V dm1 ≥31, V dp2 -V dm2 ≥28, V dm3 -V dp3 ≥18, where V dp1 is the dispersion coefficient of the first biconvex lens of the first optical sub-module, and V dm1 is the dispersion coefficient of the first negative lens of the first optical sub-module; V dp2 is the dispersion coefficient of the second biconvex lens of the second optical sub-module, and V dm2 is the dispersion coefficient of the second negative lens of the second optical sub-module; V dp3 is the dispersion coefficient of the positive lens of the third optical sub-module, and V dm3 is the dispersion coefficient of the first biconcave lens of the third optical sub-module.

[0044] Furthermore, the distance d0 from the object side mirror surface of the first optical sub-module of the objective lens to the object surface satisfies the following relational expressions: 1.1 ≤ -R0 / d0 ≤ 3.3, and 0.8 ≤ d0 / f ≤ 3.2, where R0 is the concave curvature radius of the object side mirror surface of the first optical sub-module, and f is the combined focal length of the entire microscope objective lens;

[0045] The numerical aperture range of the object space of the objective lens is between 0.3 and 0.55.

[0046] The beneficial effects brought by the technical solution provided by the present invention are as follows:

[0047] a. A method for simulating the design of a microscope objective lens is provided, which can determine the parameters of the microscope objective lens corresponding to the limit value when the imaging quality index is close to the ideal situation.

[0048] b. A microscope objective lens with a 20-fold long working distance is designed. This microscope objective lens has a relatively large working distance, good operability and process adaptability, and good optical resolution.

[0049] c. This microscope objective lens has good processing performance and excellent imaging performance, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] 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 recorded in the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0051] Figure 1 A schematic diagram of the composition of a microscope objective lens system provided for an exemplary embodiment of the present invention;

[0052] Figure 2 A modulation transfer function (MTF) graph of a microscope objective lens provided for an exemplary embodiment of the present invention;

[0053] Figure 3 A schematic diagram of the composition of a second optical sub-module including two second double convex lenses and one second double concave lens provided for an exemplary embodiment of the present invention;

[0054] Figure 4 A schematic diagram of the composition of a second optical sub-module including multiple groups of corresponding second double convex lenses and second negative lenses provided for an exemplary embodiment of the present invention;

[0055] Figure 5 For Figure 4 A schematic diagram of the composition of a second optical sub-module in which one of the second negative lenses is a double negative lens in the illustrated embodiment;

[0056] Figure 6 A schematic diagram of the composition of a second optical sub-module including three second double convex lenses and two second negative lenses provided for an exemplary embodiment of the present invention;

[0057] Figure 7 A schematic diagram of the composition of a second optical sub-module including two second double convex lenses and one second negative lens provided for an exemplary embodiment of the present invention;

[0058] Figure 8 To adjust the cemented lens 2 in the illustrated embodiment to the schematic composition diagram of the second optical sub-module corresponding to the left side of the cemented lens 1. Figure 1 The schematic composition diagram of the second optical sub-module corresponding to the left side of the cemented lens 1. Specific implementation manners

[0059] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0060] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, device, product or equipment comprising a series of steps or units does not necessarily need to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or equipment.

[0061] In an embodiment of the present invention, as Figure 1 , which is the schematic composition diagram of a microscopic objective lens system provided for an exemplary embodiment of the present invention, provides a microscopic objective lens simulation design method, including the following steps:

[0062] 1. Design a microscopic objective lens structure including three sub-optical modules, specifically as follows:

[0063] Arrange the first optical sub-module G1, the second optical sub-module G2, and the third optical sub-module G3 in sequence from the object plane to the image plane along the optical axis, where the second optical sub-module G2 and the third optical sub-module G3 are relatively spaced apart;

[0064] The first optical sub-module G1 includes a crescent positive lens L1, a first negative lens L2, and a first biconvex lens L3 arranged in sequence from the object plane to the image plane. Among them, the concave surface of the crescent positive lens L1 faces the object plane, the concave surface of the first negative lens L2 is bonded to one convex surface of the first biconvex lens L3 to form a cemented lens, and the first biconvex lens L3 is adjacent to the second optical sub-module G2;

[0065] The second optical sub-module G2 described above includes three second double convex lenses L4, L6, and L7, a second double concave lens L5, and a concave lens L8. Among them, two second double convex lenses L4 and L6 are respectively bonded to the second double concave lens L5 to form a cemented lens 1, and another second double convex lens L7 is bonded to the concave lens L8 to form another cemented lens 2. The cemented lens 1 is closer to the object side than the cemented lens 2.

[0066] The third optical sub-module G3 includes a positive lens L9 and a first double concave lens L10 arranged in sequence. Among them, the convex surface of the positive lens L9 is bonded to one of the concave surfaces of the first double concave lens L10.

[0067] The air separation distance between the second optical sub-module G2 and the third optical sub-module G3 is set to 11.7861 mm, and the overall combined focal length of the microscope objective is 10 mm.

[0068] Second, aiming at a microscope objective with a working distance between 16 and 25 times the length, design the lens optical parameters of the lenses of the first optical sub-module G1, the second optical sub-module G2, and the third optical sub-module G3, such as: focal length, refractive index, radius of curvature, and dispersion coefficient.

[0069] In this embodiment, the lens optical parameters of the first optical sub-module G1 are designed as follows:

[0070] The dispersion coefficient V of the first double convex lens L3 dp1 ≥78;

[0071] The combined focal length of the first optical sub-module G1 satisfies the following relationship: 1.0 ≤ f1 / f ≤ 4.2, where f1 is the combined focal length of the first optical sub-module G1, and f is the overall combined focal length of the microscope objective.

[0072] 1.3 ≤ R1 / f ≤ 5.2, where R1 is the radius of curvature of the cemented surface of the first negative lens L2 and the first double convex lens L3, and f is the overall combined focal length of the microscope objective.

[0073] V dp1 -V dm1 ≥25, where V dp1 is the dispersion coefficient of the first double convex lens L3, and V dm1 is the dispersion coefficient of the first negative lens L2.

[0074] Among them, the optical parameters of the crescent positive lens L1 are further designed as follows:

[0075] 1.6 ≤ f L1 / f ≤ 6.4, where f L1is the focal length of the crescent positive lens L1, and f is the combined focal length of the entire microscope objective;

[0076] 1.1 ≤ -R0 / d0 ≤ 4.6, where R0 is the radius of curvature of the concave surface of the crescent positive lens L1 facing the object surface, and d0 is the distance from the object surface to the object-side mirror surface of the crescent positive lens L1;

[0077] 1.65 ≤ N0 ≤ 2.1, where N0 is the refractive index of the crescent positive lens L1.

[0078] The lens optical parameters of the second optical sub-module G2 are designed as follows:

[0079] The dispersion coefficient V of the at least two second biconvex lenses dp2 ≥ 78;

[0080] The combined focal length of the second optical sub-module G2 satisfies the following relationship: 2.0 ≤ f2 / f ≤ 8, where f2 is the combined focal length of the second optical sub-module, and f is the combined focal length of the entire microscope objective;

[0081] The outer surfaces of the lenses of the second optical sub-module G2 close to the object surface are all convex surfaces. For Figure 1 example, there are two lenses in the second optical sub-module G2. The left lens is the cemented lens 1 formed by cementing the second biconvex lens L4, the second biconcave lens L5, and the second biconvex lens L6. The right lens is another cemented lens 2 formed by cementing the second biconvex lens L7 and the concave lens L8; and the radius of curvature R2 of the convex outer surface of the lens closest to the image side in the second optical sub-module G2 satisfies the relationship: 1.4 ≤ R2 / f ≤ 3.7, where f is the combined focal length of the entire microscope objective; in this embodiment, the lens closest to the image side in the second optical sub-module G2 is the cemented lens formed by cementing the second biconvex lens L7 and the concave lens L8, and the radius of curvature R2 refers to its convex outer surface, that is, the left convex surface of this cemented lens in Figure 1 the figure.

[0082] V dp2 -V dm2 ≥ 20, where V dp2 is the dispersion coefficient of the second biconvex lenses (L4, L6, and L7), and V dm2 is the dispersion coefficient of the second biconcave lens L5;

[0083] N m2 –N p2 ≥ 0.06, where N m2 is the refractive index of the second biconcave lens L5, and N p2 is the refractive index of the second biconvex lenses (L4, L6, and L7);

[0084] 1.1 ≤ fL2 / f ≤ 5.5, where f L2 is the focal length of the second double convex lenses (L4, L6, and L7), and f is the combined focal length of the entire microscope objective lens.

[0085] In this embodiment, the lens optical parameters of the third optical sub-module G3 are designed as follows:

[0086] 0.98 ≤ -f3 / f ≤ 4, where f3 is the combined focal length of the third optical sub-module G3, and f is the combined focal length of the entire microscope objective lens;

[0087] 0.51 ≤ R3 / f ≤ 2.2, where R3 is the radius of curvature of the concave surface closest to the image side in the third optical sub-module G3, and f is the combined focal length of the entire microscope objective lens;

[0088] N p3 –N m3 ≥ 0.18, where N p3 is the refractive index of the positive lens L9 of the third optical sub-module G3, and N m3 is the refractive index of the first double concave lens L10;

[0089] V dm3 -V dp3 ≥ 12, where V dp3 is the dispersion coefficient of the positive lens L9 of the third optical sub-module G3, and V dm3 is the dispersion coefficient of the first double concave lens L10.

[0090] III. The corresponding MTF (Modulation Transfer Function) curves of different design schemes are obtained through simulation, and the better design scheme of the microscope objective lens is determined by comparing the MTF curves corresponding to each design scheme.

[0091] Through multiple simulation calculations by adjusting parameters, a 20x long working distance microscope objective lens is designed, and its structure is as Figure 1 shown. By adjusting the optical parameter design of the optical sub-module therein, the MTF diagram of the objective lens is as Figure 2 shown, and the corresponding design scheme is determined as the better design scheme, specifically as follows:

[0092] The numerical aperture of the object side of the objective lens is 0.45, the combined focal length f of the entire microscope objective lens is 10 mm, the working distance d0, that is, the distance from the object surface to the object side mirror surface of the crescent positive lens L1, is 15.9 mm, the maximum semi-image height Hy = 12.5 mm using a tube lens with a focal length of 200 mm, and the characteristic parameters of each single lens of the first optical sub-module G1, the second optical sub-module G2, and the third optical sub-module G3 in the microscope objective lens are shown in Table 1:

[0093] Table 1

[0094]

[0095]

[0096] For the surfaces numbered (1) to (15) from the object surface to the image surface in the above table, see Figure 1 each surface and cemented surface of the lenses from left to right in . The "thickness / spacing" in the above table represents the distance from the current surface to the adjacent next surface. For example, surface (1) is the left surface of the meniscus positive lens L1, and its adjacent next surface is the right surface of the meniscus positive lens L1. The spacing of surface (1) is 3.192169 mm, indicating that the thickness of the meniscus positive lens L1 is 3.192169 mm. Another example is that the spacing of surface (5) is 0.2489306 mm, indicating that the spacing between the right surface of the first biconvex lens L3 and the left surface of the second biconvex lens L4 is 0.2489306 mm, that is, the air distance between the first optical sub-module G1 and the second optical sub-module G2 is 0.2489306 mm.

[0097] And the proportional relationship between the single-surface characteristic parameters and the overall focal length of the objective lens is shown in Table 2:

[0098] Table 2

[0099] <![CDATA[f1 / f]]> 2.07 <![CDATA[f2 / f]]> 3.96 <![CDATA[-f3 / f]]> 1.94 <![CDATA[d0 / f]]> 1.59 <![CDATA[-R0 / d0]]> 2.30 <![CDATA[R1 / f]]> 2.65 <![CDATA[R2 / f]]> 1.87 <![CDATA[R3 / f]]> 1.06 <![CDATA[f L1 / f]]> 3.15

[0100] Perform optical simulation on the microscope objective lens in the above embodiment, as Figure 2 shown, which is the modulation transfer function MTF diagram of the microscope objective lens provided by an exemplary embodiment of the present invention. In the modulation transfer function MTF diagram of the optical system, the horizontal axis is the spatial frequency, with the unit of line pairs per millimeter (lp / mm). The number of line pairs that can be resolved per millimeter is the value of the resolution. The vertical axis is the modulation transfer function MTF, which is a quantitative description of the resolution of the lens. The modulation (abbreviated as M) is used to represent the magnitude of the contrast. Let the maximum brightness be I max , and the minimum brightness be I min . The modulation M is defined as: M = (I max - I min ) / (I max + I min ). The modulation ranges from 0 to 1. The larger the modulation, the greater the contrast. When the maximum brightness and the minimum brightness are exactly equal, the contrast completely disappears, and the modulation at this time is equal to 0. For a sine wave with an original modulation of M, if the modulation of the image reaching the image plane after passing through the lens is Mˊ, then the MTF function value is: MTF value = Mˊ / M.

[0101] It can be seen that the MTF value must be between 0 and 1. The closer it is to 1, the better the performance of the lens. If the MTF value of the lens is equal to 1, the modulation transferred by the lens output fully reflects the contrast of the input sine wave. If the modulation of the input sine wave is 1, the modulation of the output image is exactly equal to the MTF value. Therefore, the MTF function represents the contrast of the lens at a certain spatial frequency.

[0102] The diffraction limit means that when an ideal object point is imaged by an optical system, due to the limitation of the diffraction of light in physical optics, an ideal image point cannot be obtained, but a Fraunhofer diffraction image is obtained. This diffraction image is the diffraction limit of physical optics, that is, the maximum value.

[0103] The MTF values of the representative 0 field of view, 0.5 field of view, and maximum field of view are already very close to the diffraction limit value, as can be seen from Figure 2 the MTF curve shown. As Figure 2 shown, the diffraction limit value is as shown by TSDIFF LIMIT. It can be seen that in the present invention, within a very wide visible light spectrum range, the MTF values of most fields of view are close to the diffraction limit of physical optics, that is, the imaging quality index is close to the limit value under ideal conditions, indicating that the imaging quality is very good.

[0104] In an embodiment of the present invention, different from the composition structure of the second optical sub-module G2 in the above embodiment, the second optical sub-module in this embodiment includes two second biconvex lenses and one second biconcave lens. As Figure 3 shown, the one second biconcave lens is disposed between the two second biconvex lenses, and both of its two side surfaces are attached to one convex surface of the two second biconvex lenses, and specifically, they can be glued to form an integral lens;

[0105] In an embodiment of the present invention, different from the composition structure of the second optical sub-module G2 in the above embodiment, the second optical sub-module in this embodiment includes multiple groups of corresponding second biconvex lenses and second negative lenses. As Figure 4 or Figure 5 shown, the second biconvex lens and the second negative lens in the same group are glued to form an integral lens;

[0106] In an embodiment of the present invention, different from the composition structure of the second optical sub-module G2 in the above embodiment, the second optical sub-module in this embodiment includes three second biconvex lenses and two second negative lenses. As Figure 6As shown, two second double convex lenses and two second negative lenses form cemented lenses in one-to-one correspondence, and in each of the cemented lenses, the second double convex lens is closer to the object side than the corresponding second negative lens. At least one convex surface of another second double convex lens is arranged adjacent to the convex surface of the second double convex lens in the cemented lens, that is, another second double convex lens can be arranged between the two cemented lenses, or can be designed on the side closest to the object side in the second optical sub-module as in Figure 6 the one designed in

[0107] In an embodiment of the present invention, different from the composition structure of the second optical sub-module G2 in the above embodiment, the second optical sub-module in this embodiment includes two second double convex lenses and one second negative lens, as shown in Figure 7 As shown, one second double convex lens and the second negative lens are cemented to form an integral lens, and the other second double convex lens is arranged on the side closer to the object surface, and the two second double convex lenses are arranged adjacent to each other.

[0108] In an embodiment of the present invention, different from the composition structure of the second optical sub-module G2 in the above embodiment, the second optical sub-module in this embodiment adjusts the left-right position relationship of the cemented lens 1 formed by cementing the second double convex lens L4, the second double concave lens L5, and the second double convex lens L6 and the cemented lens 2 formed by cementing the second double convex lens L7 and the concave lens L8 in the above embodiment, such that the cemented lens 2 is arranged adjacent to the left side of the cemented lens 1, as shown in Figure 8 As shown.

[0109] In the present invention, the design scheme of the second optical sub-module G2 includes but is not limited to the above-mentioned schemes. Specifically, the design of the second optical sub-module G2 only needs to meet the following conditions: it includes at least one negative lens and at least two second double convex lenses, at least one convex surface of at least one second double convex lens is attached to the concave surface of the negative lens, and the outer surfaces of the lenses in the second optical sub-module G2 facing the object surface are convex surfaces.

[0110] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0111] The above are only specific embodiments of the present application. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present application, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present application.

Claims

1. A method for simulating the design of a microscope objective lens, characterized in that, A microscope objective lens with a total of 10 lenses having optical power is obtained through the following steps: Design the first optical sub-module, which is composed of a meniscus positive lens L1, a first negative lens L2, and a first positive biconvex lens L3 arranged in sequence from the object plane to the image plane. Among them, the concave surface of the first negative lens L2 is attached to one convex surface of the first positive biconvex lens L3. The thickness of the meniscus positive lens L1 is less than the thickness of the first positive biconvex lens L3 and less than the distance from the object plane to the object side surface of the meniscus positive lens L1. Design the second optical sub-module, which is composed of a positive biconvex lens L4, a negative biconcave lens L5, a positive biconvex lens L6, a positive biconvex lens L7, and a negative lens L8 arranged in sequence from the object plane to the image plane. Among them, the positive biconvex lens L4, the negative biconcave lens L5, and the positive biconvex lens L6 form a first cemented lens. The distance between the first cemented lens and the positive biconvex lens L7 is less than the central thickness of any single lens in the first optical sub-module and the second optical sub-module. Design the third optical sub-module, which is composed of a positive lens L9 and a first negative biconcave lens L10 arranged in sequence from the object plane to the image plane. Among them, the convex surface of the positive lens L9 is attached to one concave surface of the first negative biconcave lens L10. Arrange the first optical sub-module, the second optical sub-module, and the third optical sub-module along the optical axis in sequence, so that the concave surface of the crescent positive lens L1 faces the object surface, the first positive biconvex lens L3 is arranged adjacent to the second optical sub-module, and the second optical sub-module is arranged at a relatively spaced distance from the positive lens L9 of the third optical sub-module; the distance from the object surface side mirror surface of the first optical sub-module of the objective lens to the object surface d 0 satisfies the following relational expression: 1.1 ≤ - R 0 / d 0 ≤ 3.3, and 0.8 ≤ d 0 / f ≤ 3.2, where R 0 is the concave surface curvature radius of the object surface side mirror surface of the first optical sub-module, f is the combined focal length of the overall microscope objective lens; Taking a microscope objective lens with a working distance between 16 and 25 times as the target, design one or more lens optical parameters such as the focal length, refractive index, curvature radius, and dispersion coefficient of the lenses in the first optical sub-module, the second optical sub-module, and the third optical sub-module, and simulate the corresponding MTF curves for different design schemes. Determine the better design scheme of the microscope objective lens by comparing the MTF curves corresponding to each design scheme.

2. The microscopic objective lens simulation design method according to claim 1, characterized in that The first negative lens L2 and the first positive biconvex lens L3 in the first optical sub-module are cemented lenses. The lens optical parameters of the first optical sub-module are designed as follows: The dispersion coefficient of the first positive biconvex lens L3 V dp1 ≥ 78; and / or, The combined focal length of the first optical sub-module satisfies the following relationship: 1.0 ≤ f 1 / f ≤ 4.2, where f 1 is the combined focal length of the first optical sub-module, f is the combined focal length of the overall microscope objective; and / or 1.3 ≤ R 1 / f ≤ 5.2, wherein, R 1 is the radius of curvature of the cemented surface of the first negative lens L2 and the first positive biconvex lens L3, f is the combined focal length of the overall microscope objective; and / or, V dp1 - V dm1 ≥ 25, where, V dp1 is the dispersion coefficient of the first positive biconvex lens L3, V dm1 is the dispersion coefficient of the first negative lens L2.

3. The microscopic objective lens simulation design method according to claim 1, characterized in that, The optical parameters of the meniscus positive lens L1 are designed as follows: 1.6 ≤ f L1 / f ≤ 6.4, where, f L1 is the focal length of the meniscus positive lens L1, f is the combined focal length of the microscope objective as a whole; 1.1 ≤ - R 0 / d 0 ≤ 4.6, where R 0 is the radius of curvature of the concave surface of the crescent positive lens L1 facing the object surface, d 0 is the distance from the object surface to the object-side mirror surface of the crescent positive lens L1; 1.65 ≤ N 0 ≤ 2.1, where N 0 is the refractive index of the crescent positive lens L1.

4. The microscopic objective lens simulation design method according to claim 1, wherein The lens optical parameters of the second optical sub-module are designed as follows: The combined focal length of the second optical sub-module satisfies the following relationship: 2.0 ≤ f 2 / f ≤ 8, where f 2 is the combined focal length of the second optical sub-module, f is the combined focal length of the overall microscope objective; and / or The concave surfaces of the negative biconcave lens L5 and the negative lens L8 facing the object surface are the cemented surfaces of the cemented lens, the outer surfaces of the lenses of the second optical sub-module close to the object surface are all convex surfaces, and the radius of curvature of the convex outer surface of the lens closest to the image side in the second optical sub-module R 2 satisfies the relation: 1.4 ≤ R 2 / f ≤ 3.7, where f is the combined focal length of the microscope objective as a whole; and / or V dp2 - V dm2 ≥ 20, where, V dp2 is the dispersion coefficient of the positive biconvex lens L4, the positive biconvex lens L6, and the positive biconvex lens L7, V dm2 is the dispersion coefficient of the negative biconcave lens L5 and the negative lens L8; and / or, N m2 – N p2 ≥ 0.06, where N m2 are the refractive indices of the negative meniscus lens L5 and the negative lens L8, N p2 are the refractive indices of the positive biconvex lens L4, the positive biconvex lens L6, and the positive biconvex lens L7.

5. The microscopic objective lens simulation design method according to claim 1, characterized in that The lens optical parameters of the second optical sub-module are designed as follows: 1.1 ≤ f L2 / f ≤5.5, where f L2 are the focal lengths of the positive double convex lenses L4, L6, and L7 of the second optical sub-module, f is the combined focal length of the overall microscope objective; Dispersion coefficients of positive biconvex lenses L4, L6, and L7 V dp2 ≥78.

6. The microscopic objective lens simulation design method according to claim 1, characterized in that, The positive lens L9 and the first negative biconcave lens L10 in the third optical sub-module are cemented lenses. The lens optical parameters of the third optical sub-module are designed as follows: 0.98 ≤ - f 3 / f ≤ 4, where f 3 is the combined focal length of the third optical sub-module, f is the combined focal length of the overall microscope objective; and / or, 0.51 ≤ R 3 / f ≤ 2.2, where R 3 is the radius of curvature of the concave surface closest to the image side in the third optical sub-module, f is the combined focal length of the microscope objective as a whole; and / or, N p3 – N m3 ≥ 0.18, where N p3 is the refractive index of the positive lens L9 of the third optical sub-module, N m3 is the refractive index of the first negative biconcave lens L10; and / or, V dm3 - V dp3 ≥ 12, where V dp3 is the dispersion coefficient of the positive lens L9 of the third optical sub-module, V dm3 is the dispersion coefficient of the first negative biconcave lens L10.

7. A microscope objective lens, characterized in that, Designed by using the microscope objective lens simulation design method described in any one of claims 1 to 6.

8. The microscope objective according to claim 7, characterized in that, The focal lengths of the first optical sub-module, the second optical sub-module, and the third optical sub-module of the objective lens satisfy the following relational expressions: 1.75 ≤ f 1 / f ≤ 2.75, 3.65 ≤ f 2 / f ≤ 4.75, 1.3 ≤ - f 3 / f ≤ 2.5, where f 1 is the combined focal length of the first optical sub-module, f 2 is the combined focal length of the second optical sub-module, f 3 is the combined focal length of the third optical sub-module, f is the combined focal length of the microscope objective lens as a whole.

9. The microscope objective according to claim 7, characterized in that, The dispersion coefficients of the lenses in the first optical sub-module, the second optical sub-module, and the third optical sub-module satisfy the following relational expressions: V dp1 - V dm1 ≥ 31, V dp2 - V dm2 ≥28, V dm3 - V dp3 ≥ 18, where, V dp1 is the dispersion coefficient of the first positive biconvex lens L3 of the first optical sub-module, V dm1 is the dispersion coefficient of the first negative lens L2 of the first optical sub-module; V dp2 is the dispersion coefficient of the positive biconvex lenses L4, L6, and L7 of the second optical sub-module, V dm2 is the dispersion coefficient of the negative biconcave lens L5 and the negative lens L8 of the second optical sub-module; V dp3 is the dispersion coefficient of the positive lens L9 of the third optical sub-module, V dm3 is the dispersion coefficient of the first negative biconcave lens L10 of the third optical sub-module.

10. The microscope objective according to any one of claims 7 to 9, characterized in that, The object-side numerical aperture range of the objective lens is between 0.3 and 0.55.

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