Microscopic optical system and microscope objective

Abstract

The invention discloses a microscopic optical system and a microscopic objective lens, and relates to the technical field of microscopic optical systems.The microscopic optical objective lens is provided with an entrance pupil side and an exit pupil side which are correspondingly arranged in the optical axis direction; the microscopic optical system comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens which are sequentially arranged from an entrance pupil side to an exit pupil side. By means of the arrangement, the microscopic optical system with the design wave band of 560-640 nm can be obtained, the axial color difference is smaller than 1.5 micrometers, the vertical axis color difference is smaller than 0.5 micrometer, the theoretical limit resolution can reach 1.2 micrometers, better balance can be achieved between the long working distance and the large numerical aperture, meanwhile, the imaging resolution and the view field range are considered, and the requirement for high-precision microscopic imaging is met.

Description

Technical Field

[0001] The present invention relates to the technical field of microscopic optical systems, and in particular to a microscopic optical system and a microscopic objective lens. Background Art

[0002] In recent years, with the growing demand for high-precision microscopic imaging in fields such as scientific research, industrial inspection, and biomedicine, microscope objective technology has developed rapidly. In a microscope optical system, the objective is a core component, and its performance directly determines the image quality, resolution, and practicality.

[0003] High numerical aperture objectives are widely used in fields such as biological research and semiconductor testing. A higher NA provides higher resolution and enhanced light collection capabilities, making it suitable for observing tiny structures.

[0004] Long working distance objectives are also widely used in industrial inspection, especially when obstructions or protective covers need to be avoided on the sample surface. These objectives usually sacrifice numerical aperture in exchange for a longer working distance, resulting in relatively low resolution and image quality.

[0005] However, it is currently difficult to simultaneously take into account both large numerical aperture and long working distance. Summary of the Invention

[0006] The main purpose of the present invention is to propose a microscope optical system and a microscope objective lens, aiming to improve the existing microscope objective lens structure, which is difficult to balance long working distance and large numerical aperture, and is difficult to meet the needs of high-precision microscopic imaging.

[0007] To achieve the above-mentioned object, the present invention provides a microscope optical system having an entrance pupil side and an exit pupil side correspondingly arranged along the optical axis direction, wherein the microscope optical system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged in sequence from the entrance pupil side to the exit pupil side;

[0008] The focal length of the microscopic optical system is fw, the focal length of the first lens is f1, the focal length of the second lens is f2, the focal length of the third lens is f3, the focal length of the fourth lens is f4, the focal length of the fifth lens is f5, the focal length of the sixth lens is f6, and the focal length of the seventh lens is f7. The microscopic optical system satisfies the following conditions:

[0009] fw=10mm;and -6mm≤f1≤-4mm;and 5mm≤f2≤7mm;and -11mm≤f3≤-9mm;and 19mm≤f4≤23mm;and -19mm≤f5≤-17mm;and 16mm≤f6≤19mm;and 22mm≤f7≤26mm.

[0010] In one embodiment, the optical power of the first lens is negative, and the entrance pupil side of the first lens is concave, and the exit pupil side is concave.

[0011] The optical power of the second lens is positive, and the entrance pupil side surface of the second lens is concave, and the exit pupil side surface is convex;

[0012] The optical power of the third lens is negative, and the entrance pupil side surface of the third lens is concave, and the exit pupil side surface is convex;

[0013] The fourth lens has a positive optical power, and the entrance pupil side surface of the fourth lens is concave, and the exit pupil side surface is convex;

[0014] The optical power of the fifth lens is negative, and the entrance pupil side surface of the fifth lens is convex, and the exit pupil side surface is concave;

[0015] The sixth lens has a positive optical power, and an entrance pupil side surface and an exit pupil side surface of the sixth lens are convex;

[0016] The seventh lens has positive refractive power, and the entrance pupil side surface of the seventh lens is convex, and the exit pupil side surface is concave.

[0017] In one embodiment, the second lens is cemented to the third lens;

[0018] The fifth lens is cemented to the sixth lens.

[0019] In one embodiment, the entrance pupil diameter of the microscope optical system is φ1, and φ1≤6.0 mm.

[0020] In one embodiment, the image-side effective field of view of the microscope optical system is φ2, where φ2≤1 mm.

[0021] In one embodiment, the working distance of the microscope optical system is L1, and L1≤20 mm.

[0022] In one embodiment, the total optical length of the microscope optical system is TTL, where TTL=21 mm.

[0023] In one embodiment, the numerical aperture of the microscope optical system is NA, and NA≤0.3.

[0024] In one embodiment, the image-side dominant wavelength telecentricity of the microscope optical system is A, where -0.1°≤A≤0.1°.

[0025] The present invention further provides a microscope objective lens, comprising:

[0026] lens barrel; and,

[0027] The microscopic optical system is arranged in the lens barrel, and the microscopic optical system is the microscopic optical system mentioned above.

[0028] In the technical solution of the present invention, by rationally designing the first, second, third, fourth, fifth, sixth, and seventh lenses, fw = 10 mm is achieved by rationally designing the first, second, third, fourth, fifth, sixth, and seventh lenses to achieve -6 mm ≤ f1 ≤ -4 mm, 5 mm ≤ f2 ≤ 7 mm, -11 mm ≤ f3 ≤ -9 mm, 19 mm ≤ f4 ≤ 23 mm, -19 mm ≤ f5 ≤ -17 mm, 16 mm ≤ f6 ≤ 19 mm, and 22 mm ≤ f7 ≤ 26 mm. This configuration allows for a microscope optical system with a design wavelength band of 560 nm to 640 nm, axial chromatic aberration less than 1.5 μm, vertical chromatic aberration less than 0.5 μm, and a theoretical maximum resolution of 1.2 μm. This achieves a better balance between a long working distance and a large numerical aperture, while also taking into account both imaging resolution and field of view, meeting the requirements of high-precision microscopic imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0030] Figure 1 A schematic structural diagram of an embodiment of a microscope optical system provided by the present invention;

[0031] Figure 2 for Figure 1 MTF curve of the microscope optical system;

[0032] Figure 3 for Figure 1 Axial chromatic aberration curve of the mesoscopic optical system;

[0033] Figure 4 for Figure 1 Vertical axis chromatic aberration curve of the microscope optical system;

[0034] Figure 5 for Figure 1 A plot of the field curvature curve for a mesoscopic microscope optical system.

[0035] Description of Figure Numbers:

[0036] 100. Microscope optical system; 1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens; 5. Fifth lens; 6. Sixth lens; 7. Seventh lens.

[0037] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0039] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0040] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0041] The present invention proposes a microscopic optical system, which aims to improve the existing microscopic objective lens structure, which is difficult to balance long working distance and large numerical aperture, and is difficult to meet the requirements of high-precision microscopic imaging.

[0042] See also Figure 1 In one embodiment of the present invention, the microscopic optical system 100 has an entrance pupil side and an exit pupil side correspondingly arranged along the optical axis direction, and the microscopic optical system 100 includes a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, and a seventh lens 7 arranged in sequence from the entrance pupil side to the exit pupil side;

[0043] The focal length of the microscopic optical system 100 is fw, the focal length of the first lens 1 is f1, the focal length of the second lens 2 is f2, the focal length of the third lens 3 is f3, the focal length of the fourth lens 4 is f4, the focal length of the fifth lens 5 is f5, the focal length of the sixth lens 6 is f6, and the focal length of the seventh lens 7 is f7. The microscopic optical system 100 satisfies the following conditions:

[0044] fw=10mm;and -6mm≤f1≤-4mm;and 5mm≤f2≤7mm;and -11mm≤f3≤-9mm;and 19mm≤f4≤23mm;and -19mm≤f5≤-17mm;and 16mm≤f6≤19mm;and 22mm≤f7≤26mm.

[0045] In the technical solution of the present invention, by rationally designing the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, and the seventh lens 7, the following conditions are met: -6mm≤f1≤-4mm; 5mm≤f2≤7mm; -11mm≤f3≤-9mm; 19mm≤f4≤23mm; -19mm≤f5≤-17mm; 16mm≤f6≤19mm; and 22mm≤f7≤26mm, so that fw=10mm. This configuration allows for the microscopic optical system 100 to be designed for a wavelength range of 560nm-640nm, with axial chromatic aberration less than 1.5μm and vertical chromatic aberration less than 0.5μm, and a theoretical maximum resolution of 1.2μm. This achieves a better balance between a long working distance and a large numerical aperture, while also taking into account both imaging resolution and field of view, meeting the requirements of high-precision microscopic imaging.

[0046] It should be noted that the present invention does not limit the specific values of the focal lengths of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, and the seventh lens 7. For example, in one embodiment of the present invention, the focal length f1 of the first lens 1 can be set to -6 mm, -5.9 mm, -5.8 mm, -5.7 mm, -5.6 mm, -5.5 mm, -5.4 mm, -5.3 mm, -5.2 mm, -5.1 mm, -5 mm, -4.9 mm, -4.8 mm, -4.7 mm, -4.6 mm, -4.5 mm, -4.4 mm, -4.3 mm, -4.2 mm, -4.1 mm, -4 mm, etc.

[0047] The focal length f2 of the second lens 2 can be set to 5mm, 5.1mm, 5.2mm, 5.3mm, 5.4mm, 5.5mm, 5.6mm, 5.7mm, 5.8mm, 5.9mm, 6mm, 6.1mm, 6.2mm, 6.3mm, 6.4mm, 6.5mm, 6.6mm, 6.7mm, 6.8mm, 6.9mm, 7mm...

[0048] The focal length f3 of the third lens 3 can be set to -11mm, -10.9mm, -10.8mm, -10.7mm, -10.6mm, -10.5mm, -10.4mm, -10.3mm, -10.2mm, -10.1mm, -10mm, -9.9mm, -9.8mm, -9.7mm, -9.6mm, -9.5mm, -9.4mm, -9.3mm, -9.2mm, -9.1mm, -9mm...

[0049] The focal length f4 of the fourth lens 4 can be set to 19mm, 19.1mm, 19.2mm, 19.3mm, 19.4mm, 19.5mm, 19.6mm, 19.7mm, 19.8mm, 19.9mm, 20mm, 20.1mm, 20.2mm, 20.3mm, 20.4mm, 20.5mm, 20.6mm, 20.7mm, 20.8mm, 20.9mm, 20.10mm, 20.20mm, 20.30mm, 20.40mm, 20.50mm, 20.60mm, 20.70mm, 20.80mm, 20.9mm, 20.11mm, 20.12mm, 20.13mm, 20.14mm, 20.15mm, 20.16mm, 20.17mm, 20.18mm, 20.19mm, 20.20mm, 20.21mm, 20.22mm, 20.23mm, 20.24mm, 20.25mm, 20.26mm, 20.27mm, 20.28mm, 20.29mm, 20.30mm, 20.31mm, 20.32mm 0.9mm, 21mm, 21.1mm, 21.2mm, 21.3mm, 21.4mm, 21.5mm, 21.6mm, 21.7mm, 21.8mm, 21.9mm, 22mm, 22.1mm, 22.2mm, 22.3mm, 22.4mm, 22.5mm, 22.6mm, 22.7mm, 22.8mm, 22.9mm, 23mm...

[0050] The focal length f5 of the fifth lens 5 can be set to -19mm, -18.9mm, -18.8mm, -18.7mm, -18.6mm, -18.5mm, -18.4mm, -18.3mm, -18.2mm, -18.1mm, -18mm, -17.9mm, -17.8mm, -17.7mm, -17.6mm, -17.5mm, -17.4mm, -17.3mm, -17.2mm, -17.1mm, -17mm...

[0051] The focal length f6 of the sixth lens 6 can be set to 16mm, 16.1mm, 16.2mm, 16.3mm, 16.4mm, 16.5mm, 16.6mm, 16.7mm, 16.8mm, 16.9mm, 17mm, 17.1mm, 17.2mm, 17.3mm, 17.4mm, 17.5mm, 17.6mm, 17.7mm, 17.8mm, 17.9mm, 18mm, 18.1mm, 18.2mm, 18.3mm, 18.4mm, 18.5mm, 18.6mm, 18.7mm, 18.8mm, 18.9mm, 19mm...

[0052] The focal length of the seventh lens 7 can be set to 22mm, 22.1mm, 22.2mm, 22.3mm, 22.4mm, 22.5mm, 22.6mm, 22.7mm, 22.8mm, 22.9mm, 23mm, 23.1mm, 23.2mm, 23.3mm, 23.4mm, 23.5mm, 23.6mm, 23.7mm, 23.8mm, 23.9mm, 24mm, 24.1mm, 24.2mm, 24.3mm, 24.4mm, 24.5mm, 24.6mm, 24.7mm, 24.8mm, 24.9mm, 25mm, 25.1mm, 25.2mm, 25.3mm, 25.4mm, 25.5mm, 25.6mm, 25.7mm, 25.8mm, 25.9mm, 26mm...

[0053] It is conceivable that in other embodiments of the present invention, the focal lengths of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, and the seventh lens 7 can also be set to other values, as long as they are within the corresponding numerical range. The present invention does not impose any limitation on this.

[0054] It should be further explained that, in one embodiment of the present invention, the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, and the seventh lens 7 are all configured as glass lenses. Glass lenses are not easily affected by thermal expansion and contraction and thus do not shift focus. Glass lenses can effectively resist thermal deformation, reduce the impact of temperature on the optical performance of the lens, maintain high precision for a long time, and meet the performance requirements of high and low temperature operation.

[0055] Furthermore, to reduce the processing cost of the microscope optical system 100, in a further embodiment of the present invention, the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, and the seventh lens 7 are all configured as spherical lenses. With this configuration, spherical lenses are easy to process, ensuring low processing costs, low assembly sensitivity, and improved finished product yield.

[0056] It is understood that in the present invention, the optical power of the first lens 1 is negative, the optical power of the second lens 2 is positive, the optical power of the third lens 3 is negative, the optical power of the fourth lens 4 is positive, the optical power of the fifth lens 5 is negative, the optical power of the sixth lens 6 is positive, and the optical power of the seventh lens 7 is positive. In this arrangement, the optical power of multiple lenses is reasonably coordinated to ensure the imaging quality of the microscope optical system 100.

[0057] Of course, the present invention does not limit the specific shapes of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, and the seventh lens 7. In one embodiment of the present invention, the entrance pupil side surface of the first lens 1 is concave, and the exit pupil side surface is concave; the entrance pupil side surface of the second lens 2 is concave, and the exit pupil side surface is convex; the entrance pupil side surface of the third lens 3 is concave, and the exit pupil side surface is convex; the entrance pupil side surface of the fourth lens 4 is concave, and the exit pupil side surface is convex; the entrance pupil side surface of the fifth lens 5 is convex, and the exit pupil side surface is concave; the entrance pupil side surface of the sixth lens 6 is convex, and the exit pupil side surface is convex; and the entrance pupil side surface of the seventh lens 7 is convex, and the exit pupil side surface is concave.

[0058] Furthermore, in one embodiment of the present invention, the second lens 2 and the third lens 3 are glued together. Such an arrangement can better correct the chromatic aberration of the zoom lens. At the same time, the glued connection can also reduce light energy loss and increase image clarity. Therefore, the rational use of glued parts allows optical components to improve the image quality of the optical system.

[0059] In another embodiment of the present invention, the fifth lens 5 and the sixth lens 6 are cemented together. Such an arrangement can also better correct the chromatic aberration of the zoom lens, thereby reducing light energy loss and increasing image clarity. Therefore, the rational use of cemented parts allows optical components to improve the image quality of the optical system.

[0060] Specifically, in this embodiment, the second lens 2 and the third lens 3 are cemented together, and the fifth lens 5 and the sixth lens 6 are cemented together.

[0061] The entrance pupil diameter of the microscope optical system 100 is φ1, φ1≤6.0 mm. This configuration allows more light to be irradiated onto the first lens 1, making the observation result clearer.

[0062] It should also be noted that the present invention does not limit the specific value of the entrance pupil diameter. For example, in the present invention, the value of the entrance pupil diameter can be set to 6mm, 5.9mm, 5.8mm, 5.7mm, 5.6mm, 5.5mm, 5.4mm, 5.3mm, 5.2mm, 5.1mm... In actual setting, it is only necessary to ensure that the observation results can be clearly observed.

[0063] Of course, in other embodiments of the present invention, the entrance pupil diameter may also be set to other values, as long as it is within the value range, and the present invention does not impose any limitation on this.

[0064] It should also be noted that, in another embodiment of the present invention, the image-side effective field of view of the microscopic optical system 100 is φ2, where φ2 ≤ 1 mm. This configuration ensures that the microscopic optical system 100 can accurately and fully display the object being measured on the image plane of the microscopic optical system 100.

[0065] In one embodiment of the present invention, the working distance of the microscopic optical system 100 is L1, L1≤20 mm. This configuration can achieve a long working distance for the microscopic optical system 100, thereby improving the measurement accuracy of the microscopic optical system 100 while reducing the risk of interference with the object being measured.

[0066] It will be understood that the present invention does not limit the specific value of the working distance of the microscope optical system 100. For example, in one embodiment of the present invention, the specific value of the working distance of the microscope optical system 100 can be set to 20 mm, 19 mm, 18 mm, 17 mm, 16 mm, 15 mm, 14 mm, 13 mm, 12 mm, 11 mm... In actual setting, it can be selected according to needs.

[0067] Of course, in other embodiments of the present invention, the working distance of the microscope optical system 100 may also be set to other values, as long as it is within the value range, and the present invention does not impose any limitation on this.

[0068] In another embodiment of the present invention, the total optical length of the microscopic optical system 100 is TTL, where TTL=21 mm. This configuration can reduce the length of the microscopic optical system 100, making the structure compact and achieving a small volume effect of the microscopic optical system 100.

[0069] In another embodiment of the present invention, the numerical aperture of the microscopic optical system 100 is NA, NA≤0.3. It is understood that such a setting can ensure the high resolution of the microscopic optical system 100, so that the microscopic optical system 100 maintains high resolution while ensuring its rear working distance.

[0070] At the same time, the microscope optical system 100 in the present invention can achieve a longer working distance while maintaining a large numerical aperture (NA), thereby balancing the two major characteristics of numerical aperture and working distance, and taking into account both high-precision imaging and complex operation requirements.

[0071] In addition, in other embodiments of the present invention, the image-side dominant wavelength telecentricity of the microscope optical system 100 is A, where -0.1°≤A≤0.1°.

[0072] In a specific embodiment of the present invention, the entrance pupil side surface S2 of the first lens element 1 is concave, and the exit pupil side surface S3 is concave; the entrance pupil side surface S4 of the second lens element 2 is concave, and the exit pupil side surface S5 is convex; the entrance pupil side surface S5 of the third lens element 3 is concave, and the exit pupil side surface S6 is convex; the entrance pupil side surface S7 of the fourth lens element 4 is concave, and the exit pupil side surface S8 is convex; the entrance pupil side surface S9 of the fifth lens element 5 is convex, and the exit pupil side surface S10 is concave; the entrance pupil side surface S10 of the sixth lens element 6 is convex, and the exit pupil side surface S11 is convex; the entrance pupil side surface S12 of the seventh lens element 7 is convex, and the exit pupil side surface S13 is concave.

[0073] It should be noted that, in this embodiment, the radius, center distance and refractive index of various lenses in the microscopic optical system 100 are shown in Table 1 below:

[0074] Table 1

[0075] radius Center distance Refractive index Physical Surface infinity 1(stop) infinity 1.23 2 -6.58 1 2.00 3 25.83 0.8 4 -130.55 3.2 1.95 5 -5.52 3.0 2.00 6 -16.6 0.2 7 -81.03 3.3 1.56 8 -10.6 0.2 9 55.87 1 1.94 10 12.92 3.6 1.56 11 -38.62 0.2 12 13.42 2.8 1.59 13 234.10 20

[0076] The unit of the radius is millimeter (mm), and the unit of the center distance is millimeter (mm).

[0077] It should be noted that, in this embodiment, the MTF curve of the microscope optical system 100 is as follows: Figure 2 As shown, in this embodiment, the microscope optical system 100 can always ensure a contrast ratio of 550 lp / mm greater than 0.3.

[0078] It should also be noted that, in this embodiment, the axial chromatic aberration curve of the microscope optical system 100 is as follows: Figure 3 As shown, the vertical axis chromatic aberration curve of the microscope optical system 100 is as shown in FIG. Figure 4 As shown, the field curvature curve of the microscope optical system 100 is as shown in FIG. Figure 5 shown.

[0079] The present invention further provides a microscope objective lens, which includes a lens barrel and a microscope optical system 100. The microscope optical system 100 is arranged in the lens barrel, and the specific structure of the microscope optical system 100 refers to the above embodiments. Since the present microscope objective lens adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described one by one here.

[0080] It is understandable that, in the present invention, the microscope objective lens is matched with a 200mm standard focal length tube lens to achieve a 20X magnification effect, so as to meet the precision imaging requirements in different application scenarios.

[0081] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformation made by utilizing the contents of the present invention's description and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A microscope optical system, characterized in that: The microscopic optical system has an entrance pupil side and an exit pupil side correspondingly arranged along the optical axis direction, and the microscopic optical system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged in sequence from the entrance pupil side to the exit pupil side; The focal length of the microscopic optical system is fw, the focal length of the first lens is f1, the focal length of the second lens is f2, the focal length of the third lens is f3, the focal length of the fourth lens is f4, the focal length of the fifth lens is f5, the focal length of the sixth lens is f6, and the focal length of the seventh lens is f7. The microscopic optical system satisfies the following conditions: fw=10mm;and -6mm≤f1≤-4mm;and 5mm≤f2≤7mm;and -11mm≤f3≤-9mm;and 19mm≤f4≤23mm;and -19mm≤f5≤-17mm;and 16mm≤f6≤19mm;and 22mm≤f7≤26mm.

2. The microscope optical system according to claim 1, wherein: The optical power of the first lens is negative, and the entrance pupil side of the first lens is concave, and the exit pupil side is concave. The optical power of the second lens is positive, and the entrance pupil side surface of the second lens is concave, and the exit pupil side surface is convex; The optical power of the third lens is negative, and the entrance pupil side surface of the third lens is concave, and the exit pupil side surface is convex; The fourth lens has a positive optical power, and the entrance pupil side surface of the fourth lens is concave, and the exit pupil side surface is convex; The optical power of the fifth lens is negative, and the entrance pupil side surface of the fifth lens is convex, and the exit pupil side surface is concave; The sixth lens has a positive optical power, and an entrance pupil side surface and an exit pupil side surface of the sixth lens are convex; The seventh lens has positive refractive power, and the entrance pupil side surface of the seventh lens is convex, and the exit pupil side surface is concave.

3. The microscope optical system according to claim 2, wherein: The second lens is cemented to the third lens; The fifth lens is cemented to the sixth lens.

4. The microscope optical system according to claim 1, wherein: The entrance pupil diameter of the microscopic optical system is φ1, φ1≤6.0 mm.

5. The microscope optical system according to claim 1, wherein: The image side effective field of view of the microscope optical system is φ2, where φ2≤1mm.

6. The microscope optical system according to claim 1, wherein: The working distance of the microscopic optical system is L1, and L1 is ≤ 20 mm.

7. The microscope optical system according to claim 1, wherein: The total optical length of the microscope optical system is TTL, where TTL=21 mm.

8. The microscope optical system according to claim 1, wherein: The numerical aperture of the microscope optical system is NA, and NA≤0.

3.

9. The microscope optical system according to claim 1, wherein: The image-side dominant wavelength telecentricity of the microscope optical system is A, where -0.1°≤A≤0.1°.

10. A microscope objective lens, characterized in that: The microscope objective lens comprises: lens barrel; and, A microscopic optical system is provided in the lens barrel, wherein the microscopic optical system is the microscopic optical system according to any one of claims 1 to 9.

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