Optical structure of a surgical microscope and surgical microscope

Abstract

The present application relates to a kind of optical structure of surgical microscope and surgical microscope, optical structure includes the turning unit, binocular unit sequentially arranged along the direction of light path, turning unit includes right roof prism;Binocular unit includes prism / lens group, first right-angle prism, second right-angle prism and eyepiece, prism / lens group includes small objective lens, or first right-angle prism, second right-angle prism is replaced by rhombic prism.The optical structure of the present application is designed as "inverted image-inverted image", and the right roof prism shortens the optical path of the internal light path of the turning unit by about half, which is more conducive to reducing the light vignetting of the observation light path;Two internal reflections avoid mirror image phenomenon, and the image is rotated by 180 degrees, so that the inverted image prism in binocular unit can be removed;Effectively simplify the structure of optical lens group in system.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, specifically relating to the optical structure of a surgical microscope and the surgical microscope itself. Background Technology

[0002] A surgical microscope is a precision medical optical device used for clinical microscopic observation and surgical treatment. As its core component, the optical microscopy system includes a primary microscope body and a binocular tube. Various accessories can be added along the parallel optical path between them to achieve different additional functions as needed.

[0003] To provide a comfortable ergonomic posture, existing surgical microscopes typically add a light path deflection structure above the primary mirror, deflecting the light path by 90 degrees. This allows the binoculars to be set completely horizontally, lowering the line-of-sight height, increasing the operating space, and extending the horizontal observation distance, enabling the surgeon to maintain a comfortable sitting posture. To avoid mirroring and maintain an upright image, the light path deflection structure in existing technologies is implemented using a pentaprism. For example, patent CN211123465U discloses a surgical microscope that uses a combination of a pentaprism and a Schmidt prism or other prisms to achieve light deflection and dispersion; CN216148235U discloses a surgical microscope that also uses a pentaprism as the light path deflection element, with the specific structure as shown below. Figure 1 , 2 As shown. However, due to the inherent limitations of its principle, the pentaprism has a long internal optical path and a large air gap in its fixed structure, increasing vignetting in the observation system and even completely blocking light from the edge field of view, causing daturation. Furthermore, the combined optical path of the binocular tube and eyepiece in existing surgical microscopes is the same as that of a Keplerian telescope. To observe an upright image, an inverting prism needs to be added to the optical path of the binocular tube. The most common type, the Proprism, is generally composed of three right-angle prisms cemented together, such as... Figure 17a , 17b As shown in 17c and 17d, this prism has a complex structure and high processing and assembly costs. It also has the problem of long internal optical path, which will complicate the small objective lens group and further increase the design and manufacturing costs. Summary of the Invention

[0004] One object of the present invention is to provide an optical structure for a surgical microscope.

[0005] To achieve the above objectives, the first technical solution adopted by the present invention is:

[0006] An optical structure for a surgical microscope includes a steering unit and a binoculars unit arranged sequentially along the optical path, wherein:

[0007] The steering unit includes a right-angle roof prism;

[0008] The binocular unit includes a prism / lens group, a first right-angle prism, a second right-angle prism, and an eyepiece arranged sequentially along the optical path. The prism / lens group includes a small objective lens.

[0009] The object beam is flipped 180 degrees by the right-angle roof prism, and then flipped 180 degrees again by the prism / lens group, the first right-angle prism, and the second right-angle prism to form an upright real image, which is then observed by the eyepiece.

[0010] Preferably, in the above technical solution, the prism / lens group is an adjustable angle prism / lens group.

[0011] More preferably, the adjustable angle prism / lens group includes a third right-angle prism, a fourth right-angle prism, and a fifth right-angle prism. The third right-angle prism, the fourth right-angle prism, and the fifth right-angle prism are arranged sequentially along the optical path. The third right-angle prism and the fifth right-angle prism can rotate relative to the fourth right-angle prism around the optical axis, and the rotation angle is always equal.

[0012] More preferably, the prism / lens group includes a semi-pentagonal prism, and the small objective lens and the semi-pentagonal prism are arranged sequentially along the optical path.

[0013] Preferably, the prism / lens group described above does not include a meniscus lens.

[0014] Preferably, the above technical solution includes a first cemented doublet lens group with positive optical power, and satisfies the following:

[0015] 50mm<|f G1 | <200mm,

[0016]

[0017] Where: f G1 The focal length of the first cemented doublet lens group.

[0018] R1 is the radius of curvature of the cemented surface of the cemented doublet lens group.

[0019] This refers to the effective pore size of the adhesive surface.

[0020] More preferably, the eyepiece comprises a single lens and a second cemented doublet lens group arranged sequentially along the optical path direction, and satisfies the following:

[0021] 0.5 < f G3 / f G1 <2,

[0022] Where: f L3 This is the focal length of the second cemented doublet lens group.

[0023] Preferably, in the above technical solution, the binocular unit further includes a field lens, which is a single lens.

[0024] In a preferred embodiment of the above technical solution, the binocular unit further includes an aperture stop.

[0025] To achieve the above objectives, the second technical solution adopted by the present invention is:

[0026] An optical mechanism for a surgical microscope includes a steering unit and a binoculars unit arranged sequentially along the optical path, wherein:

[0027] The steering unit includes a right-angle roof prism;

[0028] The binocular unit includes a prism / lens group, an oblique prism, and an eyepiece arranged sequentially along the optical path. The prism / lens group includes a small objective lens.

[0029] The object beam is flipped 180 degrees by the right-angle roof prism, and then flipped 180 degrees again by the prism / lens group and the rhomboid prism to form an upright real image, which is then observed through the eyepiece.

[0030] To achieve the above objectives, the third technical solution adopted by the present invention is:

[0031] Another object of the present invention is to provide a surgical microscope.

[0032] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0033] A surgical microscope includes a microscope body, a steering extender, and a binocular tube. The steering extender is connected to the microscope body, and the binocular tube is connected to the steering extender. The surgical microscope also includes the aforementioned optical structure. The steering unit is disposed within the steering extender, and the binocular unit is disposed within the binocular tube.

[0034] Preferably, in the above technical solution, the binocular tube has a rotating connection assembly that is connected to the steering extender and can be rotated and adjusted in the vertical direction relative to the steering extender, and the prism / lens group is an adjustable prism / lens group, wherein the adjustable angle prism / lens group is disposed within the rotating connection assembly.

[0035] Preferably, in the above technical solution, a fixed seat is provided inside the steering extender, and the right-angle ridge prism is mounted on the fixed seat.

[0036] Preferably, in the above technical solution, the binocular lens tube and the steering extender are detachably connected.

[0037] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0038] 1. The optical path of the internal optical path of the steering extender is shortened by about half, which is more conducive to reducing the vignetting of the light in the observation optical path;

[0039] 2. By using the two internal reflections of the right-angle roof prism, the mirror phenomenon is avoided and the image is rotated 180 degrees, thus eliminating the need for the complex and costly inverted prism in the binocular unit.

[0040] 3. It avoids the excessively long optical path caused by the requirement to set an inverted prism inside the binocular tube in the existing technology, reduces the design difficulty of small objective lenses, and simplifies the structure of optical lens groups;

[0041] 4. It improves the observation effect of the optical system, simplifies the optical structure of the lens group and prism group, reduces the difficulty of assembly and calibration, and saves production and manufacturing costs. Attached Figure Description

[0042] Appendix Figure 1 This is a schematic diagram of a surgical microscope.

[0043] Appendix Figure 2 This is a schematic diagram showing the connection between the steering extender and the binocular tube in the prior art.

[0044] Appendix Figure 3a This is a schematic diagram of the optical structure of a surgical microscope in the prior art;

[0045] Appendix Figure 3b This is a schematic diagram of another optical structure of a surgical microscope in the prior art;

[0046] Appendix Figure 4a This is a front view schematic diagram of the surgical microscope in Example 1;

[0047] Appendix Figure 4b This is a top view of the surgical microscope in Example 1;

[0048] Appendix Figure 4c This is a bottom-view schematic diagram of the surgical microscope in Example 1;

[0049] Appendix Figure 5 This is a schematic diagram of the optical structure in Example 1;

[0050] Appendix Figure 6 This is the optical path diagram of the binocular lens unit in the optical structure of Embodiment 1;

[0051] Appendix Figure 7 This is a schematic diagram of the optical structure in Example 2;

[0052] Appendix Figure 8 This is the optical path diagram of the binocular lens unit in the optical structure of Example 2;

[0053] Appendix Figure 9 This is a schematic diagram of the straight-tube binocular lens in Example 3;

[0054] Appendix Figure 10 This is a schematic diagram of the binocular lens unit in the optical structure of Embodiment 3;

[0055] Appendix Figure 11 This is a schematic diagram of the 45° angled binocular tube in Example 4;

[0056] Appendix Figure 12 This is a schematic diagram of the binocular lens unit in the optical structure of Embodiment 4;

[0057] Appendix Figure 13 This is a schematic diagram of the binocular unit in the optical structure in the comparative example;

[0058] Appendix Figure 14 This is a schematic diagram of a pentaprism;

[0059] Appendix Figure 15a , 15b A schematic diagram of a right-angle roof prism;

[0060] Appendix Figure 16 This is a schematic diagram showing the overlap of a pentaprism and a right-angle roof prism;

[0061] Appendix Figure 17a , 17b 17c and 17d are schematic diagrams of the Proprism;

[0062] Appendix Figure 18a , 18b This is a schematic diagram of an orthorhombic prism.

[0063] In the attached diagrams above:

[0064] 1. Microscope body; 2. Rotation extension device; 20. Locking hole; 21. Mounting base; 3. Binocular tube; 30. Positioning hole; 31. Rotary connecting assembly;

[0065] 40. Right-angle roof prism; 41. Third right-angle prism; 42. Small objective lens; 43. Fourth right-angle prism; 44. Fifth right-angle prism; 45. First right-angle prism; 46. Second right-angle prism; 47. Field lens; 48. Aperture stop; 49. Eyepiece;

[0066] 50. Orthographic prism; 51. Semi-pentagonal prism; 52. Pentagonal prism; 53. Meniscus lens; 540, 541. Proprism; 55. Schmidt roof prism. Detailed Implementation

[0067] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0068] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0069] Example 1:

[0070] like Figure 4a As shown in Figures 4b and 4c, a surgical microscope includes a microscope body 1, a steering extender 2, and a binocular tube 3. The steering extender 2 is connected to the microscope body 1, and the binocular tube 3 is connected to the steering extender 2. Specifically, the binocular tube 3 and the steering extender 2 are detachably connected via features such as a positioning hole 30 and a locking hole 20. The binocular tube 3 has a rotating connection assembly 31, which allows the binoculars to rotate and adjust vertically relative to the steering extender 2. The rotating connection assembly 31 is a common structure for binocular tubes and will not be described in detail here.

[0071] like Figure 5 As shown: The surgical microscope is equipped with corresponding optical structures, including a steering unit and a binocular unit arranged sequentially along the optical path. The steering unit is housed within the steering extender 2, and the binocular unit is housed within the binocular tube 3. Specifically:

[0072] The steering unit includes a right-angle ridge prism 40, and a fixing seat 21 is provided inside the steering extender 2, with the right-angle ridge prism 40 mounted on the fixing seat 21.

[0073] like Figure 3a The optical structure shown uses a pentaprism 52. A comparison of the two reveals that the pentaprism 52 ( Figure 14 The optical path length is 3.41D0, and the right-angle roof prism is 40 ( Figure 15a , 15bThe optical path length of the right-angle roof prism 40 is 1.73D0 (D0 is the aperture of the prism). The optical path length of the right-angle roof prism 40 is shortened by 1.68D0 compared to the optical path length of the pentaprism 52. Based on a minimum aperture of 18mm, the optical path length of the right-angle roof prism 40 is shortened by 30.24mm compared to the pentaprism 52 (equivalent air gap of about 20mm).

[0074] Furthermore, the optical axis intersection point of the right-angle roof prism 40 is higher than the midpoint, and when the optical axis is raised by the same distance, its edge is closer to the fixed surface than that of the pentaprism 52. Figure 16 Furthermore, the air gap is shortened. Based on a minimum light aperture of 18mm, the 13.2mm air gap is replaced by glass, reducing the air gap by approximately 4.5mm.

[0075] Therefore, the use of a right-angle roof prism in this parallel optical path significantly shortens the optical path, greatly reduces the projection height of the principal ray in the edge field of view, effectively reduces edge vignetting, and avoids the occurrence of dark or even occluded image edges.

[0076] The binocular unit includes a prism / lens group, a first right-angle prism 45, a second right-angle prism 46, a field lens 47, an aperture 48, and an eyepiece 49 arranged sequentially along the optical path. The prism / lens group is an adjustable-angle prism / lens group, which is housed within the rotating connection assembly 31. In this embodiment, the adjustable-angle prism / lens group includes a third right-angle prism 41, a small objective lens 42, a fourth right-angle prism 43, and a fifth right-angle prism 44.

[0077] The entire optical structure consists of a right-angled roof prism 40, a third right-angled prism 41, a small objective lens 42, a fourth right-angled prism 43, a fifth right-angled prism 44, a first right-angled prism 45, a second right-angled prism 46, a field lens 47, an aperture 48, and an eyepiece 49 arranged sequentially along the optical path. The object beam is flipped 180 degrees by the right-angled roof prism 40, and then flipped 180 degrees again by the third right-angled prism 41, the small objective lens 42, the fourth right-angled prism 43, the fifth right-angled prism 44, the first right-angled prism 45, the second right-angled prism 46, and the field lens 47, forming an upright real image at the aperture 48, which is observed by the eyepiece 49.

[0078] like Figure 3aThe optical structure shown uses a Proprism 540. A comparison reveals that the Proprism 540 is composed of three prisms bonded together, requiring differentiation between left and right assembly methods. This makes its processing, assembly, and calibration relatively complex and costly. Furthermore, the focal length of the small objective lens 42 in existing binocular tubes is generally 170mm. Due to the requirements of the subsequent optical path structure, especially the excessively long optical path length of the Proprism 540, a thick meniscus lens 53 is needed to move the optical principal plane of the small objective lens 42 backward. However, the thick meniscus lens 53 is difficult to center, has high sensitivity to curvature radius, and strict tolerance requirements, resulting in high processing and manufacturing costs.

[0079] The application uses two right-angle prisms, which are easier to assemble and adjust, and the spacing is adjustable, which facilitates the adjustment of the interpupillary distance range. In addition, the diameter of the first right-angle prism 45 can be reduced according to the optical path, which facilitates the mechanical structure design and assembly (the center distance of the dual optical paths is generally only 22mm). At the same time, since the subsequent optical path length of the small objective lens 42 is greatly reduced, there is no need to add an additional thick meniscus lens 53 to adjust the image plane position, which simplifies the system and reduces costs.

[0080] In this embodiment:

[0081] The small objective lens 42 is a first cemented doublet (two lenses) with positive optical power, and satisfies:

[0082] 50mm|f G1 | <200mm,

[0083] Where: f G1 R is the focal length of the first cemented doublet lens group, and R1 is the radius of curvature of the cementing surface of the cemented doublet lens group. This refers to the effective pore size of the adhesive surface.

[0084] Field lens 47 is a single lens with negative optical power.

[0085] Eyepiece 49 consists of a single lens and a second cemented doublet lens group (two lenses) arranged sequentially along the optical path, and satisfies the following:

[0086] 0.5 < F L3 / f G1 <2,

[0087] Where: f L3 This is the focal length of the second cemented doublet lens group.

[0088] like Figure 6 Table 1 shows the optical parameters of the binocular unit in this embodiment:

[0089] Face number radius thickness Nd Vd Half-aperture 1 Infinity 20 1.52 64.2 10 2 Infinity 4.5 10 3 61.85 1.5 1.59 29.9 8.5 4 37.26 2.5 1.49 57.4 8.5 5 Infinity 8 8.5 6 Infinity 51 1.52 64.2 10 7 Infinity 16 10 8 Infinity 20 1.52 64.2 10 9 Infinity 16.6 10 10 Infinity 18 1.52 64.2 9 11 Infinity 10 9 12 Infinity 24 1.52 64.2 12 13 Infinity 3 12 14 -30.72 1.5 1.49 57.4 9 15 -98.9 16 9 16 Infinity 9.5 17 -238.9 2 1.85 23.8 12 18 22.839 10 1.62 60.3 12 19 -17 0.5 12 20 28.18 6 1.62 60.3 12 21 Infinity 23.5 12

[0090] Where: radius is the radius of curvature of the lens surface, thickness is the thickness of the lens center, Nd is the refractive index of d light (wavelength 589.3nm) in optical glass; Vd is the Abbe number.

[0091] The optical structure used in this embodiment is designed as an "inverted image-inverted image", which is more... Figure 3a The existing optical structure has its internal optical path shortened by about half, which is more conducive to reducing light vignetting in the observation optical path; the two internal reflections avoid the mirror phenomenon, and the image is rotated 180 degrees, which can eliminate the inverted prism in the subsequent binocular unit. The structure is simple and the cost is low.

[0092] Example 2:

[0093] This embodiment is basically the same as Embodiment 1, except that in this embodiment, a rhomboid prism 50 replaces the first right-angle prism 45 and the second right-angle prism 46 in the previous embodiment. Figure 7 As shown.

[0094] The entire optical structure consists of a right-angled roof prism 40, a third right-angled prism 41, a small objective lens 42, a fourth right-angled prism 43, a fifth right-angled prism 44, an orthographic prism 50, a field lens 47, an aperture 48, and an eyepiece 49 arranged sequentially along the optical path. The object beam is flipped 180 degrees by the right-angled roof prism 40, and then flipped 180 degrees again by the third right-angled prism 41, the small objective lens 42, the fourth right-angled prism 43, the fifth right-angled prism 44, and the orthographic prism 50 to form an upright real image. The image is then observed by the eyepiece 49 through the field lens 47 and the aperture 48.

[0095] like Figure 3a The optical structure shown uses a Proprism 540. After comparing the two, it was found that the optical path length of the Proprism 540 is 4D0, while the optical path length of the rhombic prism 50 is 2D0. The optical path length of the rhombic prism 50 is 2D0 shorter than that of the Proprism 540. Based on a minimum aperture of 22mm, the optical path length of the rhombic prism 50 is 44mm shorter than that of the Proprism 540.

[0096] This application uses a rhombic prism 50, such as Figure 18a , 18b As shown, the left and right prisms are consistent, and the processing, assembly and calibration are relatively simple and low cost.

[0097] like Figure 8 Table 2 shows the optical parameters of the binocular unit in this embodiment:

[0098] Face number radius thickness Nd Vd Half-aperture 1 Infinity 20 1.52 64.2 10 2 Infinity 4.5 10 3 61.85 1.5 1.59 29.9 8.5 4 37.26 2.5 1.49 57.4 8.5 5 Infinity 8 8.5 6 Infinity 51 1.52 64.2 10 7 Infinity 16 10 8 Infinity 20 1.52 64.2 10 9 Infinity 16.6 10 10 Infinity 52 1.52 64.2 9 11 Infinity 3 12 12 -30.72 1.5 1.49 57.4 9 13 -98.9 18 9 14 Infinity 9.5 15 -238.9 2 1.85 23.8 12 16 22.839 10 1.62 60.3 12 17 -17 0.5 12 18 28.18 6 1.62 60.3 12 19 Infinity 23.5 12

[0099] Example 3:

[0100] This embodiment is basically the same as Embodiment 1, except that in this embodiment, the binocular tube is a straight binocular tube, such as... Figure 9 As shown, without the rotating connecting assembly 31, the optical axis of the eyepiece 49 remains parallel to the optical axis of the small objective lens 42. In this case, the prism / lens group only includes the small objective lens 42, as shown. Figure 10 As shown.

[0101] That is, the binocular unit consists of a small objective lens 42, a first right-angle prism 45, a second right-angle prism 46, a field lens 47, an aperture 48, and an eyepiece 49 arranged sequentially along the optical path.

[0102] like Figure 3b The optical structure shown uses a Proprism 541. A comparison reveals that the Proprism 541 is composed of two large right-angle prisms bonded together, requiring differentiation between left and right assembly methods. This results in a large structural space occupation, heavy weight, and relatively complex processing, assembly, and calibration, leading to high costs. In contrast, this application uses two right-angle prisms, which are easier to assemble and adjust, with adjustable spacing, facilitating interpupillary distance adjustment, simplifying mechanical structure design and assembly, and offering advantages such as smaller footprint, lighter weight, easier processing, assembly, and calibration, and lower cost.

[0103] Example 4:

[0104] This embodiment is basically the same as Embodiment 1, except that in this embodiment, the binocular tube is a 45° angled binocular tube, such as... Figure 11 As shown, without the rotating connecting assembly 31, the optical axis of the eyepiece 49 and the optical axis of the small objective lens 42 maintain a 45° angle. In this case, the prism / lens group includes the small objective lens 42 and a semi-pentaprism 51, which are arranged sequentially along the optical path direction, as shown below. Figure 12 As shown.

[0105] That is, the binocular unit consists of a small objective lens 42, a semi-pentagonal prism 51, a first right-angle prism 45, a field lens 47, a second right-angle prism 46, an aperture 48, and an eyepiece 49 arranged sequentially along the optical path.

[0106] For example Figure 13 The optical structure shown uses a Schmidt roof prism 55. The semi-pentaprism 51 used in this embodiment is relatively simple to process, assemble and correct, and has low cost.

[0107] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An optical structure for a surgical microscope, comprising a steering unit and a binoculars unit arranged sequentially along the optical path, characterized in that: The steering unit includes a right-angle roof prism; The binocular unit includes a prism / lens group, a first right-angle prism, a second right-angle prism, and an eyepiece arranged sequentially along the optical path. The prism / lens group includes a small objective lens, and the small objective lens includes a first cemented doublet lens group with positive optical power, and satisfies the following: ， <15, of which: The focal length of the first cemented doublet lens group. Let be the radius of curvature of the cemented surface of the cemented doublet lens group. The effective pore size of the glued surface. The eyepiece comprises a second cemented doublet lens group and a single lens arranged sequentially along the optical path, and satisfies the following: ， in: The focal length of the second cemented doublet lens group. The object beam is flipped 180 degrees by the right-angle roof prism, and then flipped 180 degrees again by the prism / lens group, the first right-angle prism, and the second right-angle prism to form an upright real image, which is then observed by the eyepiece.

2. The optical structure of the surgical microscope according to claim 1, characterized in that: The aforementioned prism / lens group is an adjustable angle prism / lens group.

3. The optical structure of the surgical microscope according to claim 2, characterized in that: The adjustable angle prism / lens group includes a third right-angle prism, a fourth right-angle prism, and a fifth right-angle prism, which are arranged sequentially along the optical path. The third and fifth right-angle prisms can rotate relative to the fourth right-angle prism around the optical axis, and the rotation angles are always equal.

4. The optical structure of the surgical microscope according to claim 1, characterized in that: The prism / lens group includes a semi-pentagonal prism, and the small objective lens and the semi-pentagonal prism are arranged sequentially along the optical path.

5. The optical structure of the surgical microscope according to claim 1, characterized in that: The prism / lens group does not include a meniscus lens.

6. The optical structure of the surgical microscope according to claim 1, characterized in that: The binocular unit also includes a field lens, which is a single lens.

7. An optical mechanism for a surgical microscope, comprising a steering unit and a binoculars unit arranged sequentially along the optical path, characterized in that: The steering unit includes a right-angle roof prism; The binocular unit includes a prism / lens group, an oblique prism, and an eyepiece arranged sequentially along the optical path. The prism / lens group includes a small objective lens, and the small objective lens includes a first cemented doublet lens group with positive optical power, and satisfies the following: ， <15, of which: The focal length of the first cemented doublet lens group. Let be the radius of curvature of the cemented surface of the cemented doublet lens group. The effective pore size of the glued surface. The eyepiece comprises a second cemented doublet lens group and a single lens arranged sequentially along the optical path, and satisfies the following: ， in: The focal length of the second cemented doublet lens group. The object beam is flipped 180 degrees by the right-angle roof prism, and then flipped 180 degrees again by the prism / lens group and the rhomboid prism to form an upright real image, which is then observed by the eyepiece.

8. A surgical microscope, comprising a microscope body, a steering extender, and a binocular tube, wherein the steering extender is connected to the microscope body, and the binocular tube is connected to the steering extender, characterized in that: The surgical microscope further includes the optical structure described in any one of claims 1 to 6, wherein the steering unit is disposed within the steering extender, and the binocular unit is disposed within the binocular tube.

9. The surgical microscope according to claim 8, characterized in that: The binocular lens tube has a rotating connection assembly that is connected to the steering extender and can be rotated and adjusted in the vertical direction relative to the steering extender. The prism / lens group is an adjustable angle prism / lens group, which is disposed within the rotating connection assembly.

10. The surgical microscope according to claim 8, characterized in that: The binoculars and the steering extender are detachably connected.

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