Ultrahigh-definition hard tube endoscope optical system
By designing a reverse telescopic objective lens system and a dual telecentric relay lens group, combined with a cemented structure of various lenses and prisms, the problem of insufficient imaging quality of existing endoscopes in a wide field of view and a wide spectral range has been solved, achieving ultra-high-definition and low-distortion endoscopic imaging effects.
Patent Information
- Application Number
- CN202520193916.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-07
- Publication Date
- 2025-12-16
- Estimated Expiration
- 2035-02-07
AI Technical Summary
Existing endoscopic imaging systems struggle to achieve ultra-high-definition, low-distortion imaging over wide field of view and broad spectral range, resulting in limited detection accuracy, high costs, and increased complexity of the optical system.
By employing a reverse telephoto objective system and a double telecentric relay lens group, combined with a cemented structure of various lenses and prisms, ultra-high-definition imaging with a large field of view is achieved by correcting axial chromatic aberration, transverse chromatic aberration, and field curvature, and compressing the diameter of the optical system.
It achieves a center angle resolution greater than 18°/°, distortion less than 5%, and a field of view ≥80°, while supporting ultra-high-definition imaging in both white light and fluorescence bands, reducing the complexity and cost of the optical system.
Smart Images
Figure CN223679437U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to an optical system, specifically an ultra-high-definition rigid endoscope optical system, belonging to the field of optical imaging technology. Background Technology
[0002] Current fluorescence endoscopes, when used in conjunction with specific cold light sources, camera systems, and ICG, can simultaneously image in both white light and fluorescence wavelengths. This allows for the clinical examination and treatment of intra-abdominal diseases, determining the location, size, appearance, and extent of lesions, significantly improving the accuracy of intra-abdominal disease diagnosis and compensating for the shortcomings of traditional methods. Ultra-high definition and low distortion have consistently been development directions for high-end endoscopic equipment.
[0003] Current status and problems of endoscopes: The central angular resolution of mainstream FHD (full HD) endoscopes is about 8C / °, and the central angular resolution of 4K laparoscopy has not exceeded 15C / °; there are very few fluorescent rigid endoscope optical imaging systems with a central angular resolution higher than 15C / ° and distortion lower than 5%.
[0004] Existing technical challenges: The formula for angular resolution, a parameter for determining endoscopic imaging quality, is as follows: Where r(d) is the limit of resolvable line pairs per millimeter, and its formula is: At a standard working distance of 50mm, under the same field of view and wavelength, the larger the entrance pupil diameter D, the larger the resolution r(d), and the larger the angular resolution r. a (d) The higher the value, the better. Currently, mainstream manufacturers' endoscope products with a working wavelength of 0.45-0.86um have a maximum entrance pupil diameter of 0.5mm, which limits further improvements in angular resolution and overall resolution.
[0005] However, a wide operating wavelength, a small F-number, a large entrance pupil diameter, and a large field of view introduce greater axial chromatic aberration, transverse chromatic aberration, and distortion. The difficulty in correcting the field curvature and transverse chromatic aberration accumulated by the relay system further increases, as does the difficulty in compressing the diameter of the optical system. These parameters limit the clarity of the optical system or increase its complexity, resulting in few rigid laparoscopic products on the market that can simultaneously achieve ultra-high-definition imaging and low distortion in both white light and fluorescence bands. Furthermore, most of these products suffer from complex optical system structures, high costs, and insufficient imaging clarity, limiting their use, affecting detection accuracy, and increasing costs for hospitals and patients. Summary of the Invention
[0006] The purpose of this invention is to provide an ultra-high-definition rigid endoscope optical system with a central angular resolution greater than 18C / °, distortion less than 5%, and a field of view ≥80°, which can simultaneously achieve ultra-high-definition, low-distortion imaging in both white light and near-infrared light bands.
[0007] In order to achieve the above object, the technical scheme of the utility model is: a kind of super high-definition rigid tube endoscope optical system, including objective lens system, relay lens system and eyepiece system being sequentially arranged along the direction of light propagation, the relay lens system is located between objective lens system and eyepiece system,
[0008] The objective lens system is reverse telephoto structure,
[0009] The relay lens system includes n groups of relay lens groups, and each group of relay lens group is double telecentric structure, the relay lens group is by two four cemented rod lenses symmetrically arranged, wherein, n is odd,
[0010] The eyepiece system is object side telecentric structure,
[0011] Its innovation lies in:
[0012] The objective lens system includes sapphire protective lens, negative power lens, flat concave negative power lens, prism or turning prism, first positive power three cemented lens, negative power three cemented lens, negative power double cemented lens and first positive power lens being arranged along the direction of light propagation, the convex surface of negative power lens is arranged at the inner side of sapphire protective lens, and the concave surface of negative power lens is cemented with the plane of flat concave negative power lens, the prism or turning prism is arranged between the concave surface of flat concave negative power lens and the plane of first positive power three cemented lens, the convex surface of first positive power three cemented lens is arranged adjacent to the convex surface of one side of negative power three cemented lens, the convex surface of the other side of negative power three cemented lens is arranged adjacent to the convex surface of one side of negative power double cemented lens, and the concave surface of the other side of negative power double cemented lens is close to the convex surface of one side of first positive power lens,
[0013] The convex surface of the other side of first positive power lens is located at one side of n groups of relay lens groups, and the eyepiece system is located at the other side of n groups of relay lens groups.
[0014] In the above technical scheme, the eyepiece system includes second positive power three cemented lens, second positive power lens, positive power double cemented lens and sapphire lens being arranged along the direction of light propagation, the second positive power three cemented lens is located between the other side of n groups of relay lens groups and the convex surface of one side of second positive power lens, the convex surface of the other side of second positive power lens is adjacent to the convex surface of one side of positive power double cemented lens, and the concave surface of the other side of positive power double cemented lens is adjacent to sapphire lens.
[0015] In the technical scheme, the first positive focal length three-cemented lens is integrated by a first lens, a second lens and a third lens, a flat surface of the first lens is arranged on one side of a prism or a turning prism, a convex surface of the first lens is cemented with a concave surface on one side of the second lens, a concave surface on the other side of the second lens is cemented with a convex surface on one side of the third lens, and a convex surface on the other side of the third lens is arranged adjacent to a convex surface on one side of the negative focal length three-cemented lens.
[0016] In the technical scheme, the negative focal length three-cemented lens is integrated by a fourth lens, a fifth lens and a sixth lens, concave surfaces on two sides of the fifth lens are respectively integrated with a convex surface on one side of the fourth lens and a convex surface on one side of the sixth lens, a convex surface on the other side of the fourth lens is close to a convex surface on the other side of the first positive focal length three-cemented lens, and a convex surface on the other side of the sixth lens is close to a convex surface on one side of the negative focal length double-cemented lens.
[0017] In the technical scheme, the negative focal length double-cemented lens is integrated by a seventh lens and an eighth lens, a convex surface on one side of the seventh lens is cemented with a convex surface on the other side of the negative focal length three-cemented lens, a convex surface on the other side of the seventh lens is cemented with a concave surface on one side of the eighth lens, and a concave surface on the other side of the eighth lens is close to a convex surface on one side of the first positive focal length lens.
[0018] In the technical scheme, the four-cemented rod lens is integrated by a convex lens, a meniscus rod lens, a double-concave lens and a double-convex lens, two sides of the meniscus rod lens are respectively cemented with a convex surface on one side of the convex lens and a concave surface on one side of the double-concave lens, and a concave surface on the other side of the double-concave lens is cemented with a convex surface on one side of the double-convex lens.
[0019] In the technical scheme, the second positive focal length three-cemented lens is integrated by a ninth lens, a tenth lens and an eleventh lens, two sides of the tenth lens are respectively cemented with a convex surface of the ninth lens and a convex surface on one side of the eleventh lens, a convex surface on the other side of the eleventh lens is adjacent to a convex surface on one side of the second positive focal length lens, the positive focal length double-cemented lens is integrated by a twelfth lens and a thirteenth lens, a concave surface of the twelfth lens is cemented with a convex surface of the thirteenth lens, and a convex surface on the other side of the second positive focal length lens is adjacent to a convex surface of the twelfth lens.
[0020] In the technical scheme, a first aperture stop is arranged between the prism or the turning prism and the first positive focal length three-cemented lens, and a refractive index of the prism or the turning prism is 1.9≤n≤2.1; the prism or the turning prism is integrated with the plano-concave negative focal length lens by low-refractive epoxy resin cement, and a refractive index of the epoxy resin cement is n 胶水 ≤1.6.
[0021] In the above technical solution, the combined optical power of the negative power lens and the plano-concave negative power lens is between -0.55 and -0.4, and their combined focal length f1 / f 物镜 The ratio satisfies -1.9 ≤ f1 / f 物镜 ≤-0.4, f 物镜 is the focal length of the objective lens system.
[0022] In the above technical solution, the objective lens system:
[0023] The focal length f2 of the first positive power cemented lens satisfies 2.5 ≤ f2 / f 物镜 ≤8.5,
[0024] The negative optical power cemented lens has a focal length f3 that satisfies -42 ≤ f3 / f 物镜 ≤-10,
[0025] The negative optical power cemented doublet has a focal length f4 that satisfies -200≤f4 / f 物镜 ≤-60,
[0026] The focal length f5 of the first positive power lens satisfies 3.5 ≤ f5 / f 物镜 ≤12,
[0027] Among them, f 物镜 is the focal length of the objective lens system.
[0028] The positive effects of this invention are as follows: When using the ultra-high-definition rigid endoscope optical system of this invention, the objective lens system includes a sapphire protective lens, a negative power lens, a plano-concave negative power lens, a prism or steering prism, a first positive power cemented triplet lens, a negative power cemented triplet lens, a negative power cemented doublet lens, and a first positive power lens, all arranged along the direction of light propagation. The convex surface of the negative power lens is located inside the sapphire protective lens. The concave surface of the negative power lens is cemented to the planar surface of the plano-concave negative power lens. The prism or steering prism is disposed between the concave surface of the plano-concave negative power lens and the planar surface of the first positive power cemented triplet lens. The convex surface of the first positive power cemented triplet lens is adjacent to the convex surface of one side of the negative power cemented triplet lens, and the convex surface of the other side of the negative power cemented triplet lens is adjacent to the convex surface of one side of the negative power cemented doublet lens. The concave surface of the other side of the negative power cemented doublet lens is close to the convex surface of one side of the first positive power lens.
[0029] The convex surface of the first positive power lens is located on one side of the n-group relay lens assembly, and the eyepiece system is located on the other side of the n-group relay lens assembly.
[0030] The objective lens system is used to correct large field-of-view distortion and balance the accumulation of transverse aberration and field curvature caused by the relay system; glass cemented lenses with multiple dispersion coefficients are used to correct axial and transverse chromatic aberration, field curvature, and distortion caused by the large relative aperture across the entire white light to fluorescence bands.
[0031] The relay mirror system not only effectively reduces transverse chromatic aberration and field curvature caused by the large relative aperture and simplifies objective lens design, but also effectively compresses the diameter of the entire relay system.
[0032] The eyepiece system ensures that matching the F-number of the entire optical system does not affect image quality, and enables pupil matching with the adapter. When received by the human eye, it allows for maximum eye relaxation, ensuring no visual fatigue during prolonged use. The adapter can also be used for pupil matching, and the image is projected onto the image sensor and then onto the display screen, making it more convenient for medical personnel to observe.
[0033] In summary, the endoscope optical system of this utility model is a large field-of-view system. The objective lens system uses two negative power lenses, which effectively compress the beam angle of the large field of view and allow for good control of the objective lens diameter and distortion. In addition, the four-element composite lens controls the large aperture chromatic aberration, field curvature, and diameter, so that the entire optical system can effectively control the diameter size under the condition of large relative aperture, so that the overall diameter size meets the requirements.
[0034] Meanwhile, the endoscopic optical system achieves an entrance pupil diameter of 0.74 mm, an exit pupil diameter of 5 mm, a central angular resolution of 18 C / °, distortion of less than 5%, a field of view of ≥80°, and a diameter of no more than 6.6 mm within a wavelength range of 0.45-0.86 μm; it can simultaneously achieve ultra-high-definition, low-distortion imaging in both white light and fluorescence bands. Attached Figure Description
[0035] Figure 1 This is a structural schematic diagram of one specific embodiment of the present invention;
[0036] Figure 2 This is a schematic diagram of the objective lens system structure of this utility model;
[0037] Figure 3 This is a schematic diagram of the relay lens assembly of this utility model;
[0038] Figure 4 This is a schematic diagram of the eyepiece system of this utility model;
[0039] Figure 5 This is the MTF curve of the optical system of this utility model;
[0040] Figure 6 This is a distortion diagram of the optical system of this utility model;
[0041] Figure 7 is the illumination diagram of the optical system of the utility model. DETAILED DESCRIPTION
[0042] The utility model is further explained below in combination with the drawings and the embodiments given, but is not limited thereto.
[0043] As Figure 1 , 2 , 3, 4, 5, 6, 7, an ultra-high-definition hard tube endoscope optical system, comprising objective lens system 1, relay lens system 2 and eyepiece system 3 arranged in sequence along the light propagation direction, the relay lens system 2 is located between objective lens system 1 and eyepiece system 3,
[0044] The objective lens system 1 is a reverse telephoto structure,
[0045] The relay lens system 2 includes n groups of relay lens groups, and each group of relay lens groups is a double-telecentric structure, the relay lens group is composed of two four-cemented rod mirrors arranged symmetrically, wherein n is an odd number,
[0046] The eyepiece system 3 is a telecentric structure on the object side,
[0047] The objective lens system 1 includes sapphire protective lens 11, negative power lens 12, flat concave negative power lens 13, prism or turning prism 14, first positive power three-cemented lens 15, negative power three-cemented lens 16, negative power double-cemented lens 17 and first positive power lens 18 arranged in sequence along the light propagation direction, the convex surface of negative power lens 12 is arranged on the inner side of sapphire protective lens 11, and the concave surface of negative power lens 12 is cemented with the plane of flat concave negative power lens 13, the prism or turning prism 14 is arranged between the concave surface of flat concave negative power lens 13 and the plane of first positive power three-cemented lens 15, the convex surface of first positive power three-cemented lens 15 is arranged adjacent to the convex surface of one side of negative power three-cemented lens 16, the convex surface of the other side of negative power three-cemented lens 16 is arranged adjacent to the convex surface of one side of negative power double-cemented lens 17, and the concave surface of the other side of negative power double-cemented lens 17 is close to the convex surface of one side of first positive power lens 18,
[0048] The convex surface of the other side of first positive power lens 18 is located on one side of n groups of relay lens groups, and eyepiece system 3 is located on the other side of n groups of relay lens groups.
[0049] Further, as Figure 4As shown, in order to ensure that matching the entire optical system F number does not affect the image quality, the eyepiece system 3 includes a second positive power three cemented lens 31, a second positive power lens 32, a positive power double cemented lens 33 and a sapphire lens 34 arranged along the light propagation direction, the second positive power three cemented lens 31 is located between the convex surface on the other side of the n group relay lens group and the second positive power lens 32, the convex surface on the other side of the second positive power lens 32 is adjacent to the convex surface on one side of the positive power double cemented lens 33, and the concave surface on the other side of the positive power double cemented lens 33 is adjacent to the sapphire lens 34.
[0050] Further, as shown in the figure, Figure 4 In order to correct the large field distortion and balance the accumulation of the vertical aberration and the field curvature accumulated by the relay system, the first positive power three cemented lens 15 is integrated by a first lens 151, a second lens 152 and a third lens 153, the plane of the first lens 151 is arranged on one side of the prism or turning prism 14, the convex surface of the first lens 151 is cemented with the concave surface on one side of the second lens 152, the concave surface on the other side of the second lens 152 is cemented with the convex surface on one side of the third lens 153, and the convex surface on the other side of the third lens 153 is adjacent to the convex surface on one side of the negative power three cemented lens 16.
[0051] Further, as shown in the figure, Figure 4 The negative power three cemented lens 16 is integrated by a fourth lens 161, a fifth lens 162 and a sixth lens 163, the concave surfaces on both sides of the fifth lens 162 are respectively cemented with the convex surface on one side of the fourth lens 161 and the convex surface on one side of the sixth lens 163, the convex surface on the other side of the fourth lens 161 is close to the convex surface on the other side of the first positive power three cemented lens 15, and the convex surface on the other side of the sixth lens 163 is close to the convex surface on one side of the negative power double cemented lens 17.
[0052] Further, as shown in the figure, Figure 4 The negative power double cemented lens 17 is integrated by a seventh lens 171 and an eighth lens 172, the convex surface on one side of the seventh lens 171 is cemented with the convex surface on the other side of the negative power three cemented lens 16, and the convex surface on the other side of the seventh lens 171 is cemented with the concave surface on one side of the eighth lens 172, and the concave surface on the other side of the eighth lens 172 is close to the convex surface on one side of the first positive power lens 18.
[0053] Further, as shown in the figure, Figure 5As shown, due to the symmetrical structure of the relay lens system 2, vertical aberration and telecentricity are balanced by adjusting the refractive index, dispersion coefficient, and focal length combination of the bar lenses. The four-cemented method of a single symmetrical unit not only effectively reduces the transverse chromatic aberration and field curvature caused by the large relative aperture and reduces the design difficulty of the objective lens, but also effectively compresses the diameter of the entire relay system. The four-cemented bar lens is cemented together with a convex lens 21, a meniscus bar lens 22, a biconcave lens 23, and a biconvex lens 24. The concave surfaces on both sides of the meniscus bar lens 22 are cemented to one side of the convex surface of the convex lens 21 and one side of the concave surface of the biconcave lens 23, respectively. The concave surface on the other side of the biconcave lens 23 is cemented to one side of the convex surface of the biconvex lens 24.
[0054] Furthermore, such as Figure 6 As shown, to ensure that the F-number of the entire optical system does not affect the image quality, the adapter's pupil matching can be achieved. The second positive power cemented lens 31 is cemented together by the ninth lens 311, the tenth lens 312, and the eleventh lens 313. The two sides of the tenth lens 312 are cemented to the convex surfaces of the ninth lens 311 and the convex surfaces of the eleventh lens 313 on one side, respectively. The convex surface of the eleventh lens 313 on the other side is adjacent to the convex surface of the second positive power lens 32 on one side. The positive power cemented lens 33 is cemented together by the twelfth lens 331 and the thirteenth lens 332. The concave surface of the twelfth lens 331 is cemented to the convex surface of the thirteenth lens 332. The convex surface of the second positive power lens 32 on the other side is adjacent to the convex surface of the twelfth lens 331.
[0055] Furthermore, a first aperture stop is provided between the prism or steering prism 14 and the first positive focal length cemented mirror 15, and the refractive index of the prism or steering prism 14 is 1.9≤n≤2.1; the advantage of this design is that for beams with large NA values, the steering prism is more likely to undergo total internal reflection when folding the viewing angle, thus reducing the coating accuracy requirements of the steering prism.
[0056] Furthermore, the prism or steering prism 14 and the plano-concave negative power lens 13 are bonded together with a low refractive index epoxy resin, and the refractive index n of the epoxy resin is... 胶水 ≤1.6. The advantage of this design is that, for beams with large NA values, the steering prism is more likely to undergo total internal reflection when folding the viewing angle, thus reducing the coating accuracy requirements of the steering prism.
[0057] Furthermore, the combined optical power of the negative power lens 12 and the plano-concave negative power lens 13 is between -0.55 and -0.4, and their combined focal length f1 / f 物镜 The ratio satisfies -1.9 ≤ f1 / f 物镜 ≤-0.4, f 物镜is the focal length of the objective system 1. For a large field angle beam, the large field angle beam angle is more compressed, so that the objective diameter size and distortion are well controlled.
[0058] Further, in the objective system 1:
[0059] The focal length f2 of the first positive focal length triplex cemented lens 15 satisfies 2.5≤f2 / f 物镜 ≤8.5,
[0060] The focal length f3 of the negative focal length triplex cemented lens 16 satisfies -42≤f3 / f 物镜 ≤-10,
[0061] The focal length f4 of the negative focal length doublet cemented lens 17 satisfies -200≤f4 / f 物镜 ≤-60,
[0062] The focal length f5 of the first positive focal length lens 18 satisfies 3.5≤f5 / f 物镜 ≤12,
[0063] Wherein, f 物镜 is the focal length of the objective system 1.
[0064] The cemented lenses used in each system of the utility model are all made of high-temperature-resistant ultraviolet glue and epoxy resin glue, and the high-temperature-resistant temperature of the ultraviolet glue is 125-135 DEG C. The advantages of such design are that the cemented lenses do not crack when the endoscope is high-temperature sterilized, and the service life of the endoscope during high-temperature sterilization is ensured.
[0065] As shown in Figure 5 , the MTF curve diagram of the optical system when the adapter focal length is 15.5mm. As shown in Figure 6 , the distortion of the optical system under the full field of view is less than 5%. As shown in Figure 7 , the illumination of the optical system under the full field of view is greater than 0.9.
[0066] The objective system of the utility model corrects the large field distortion and balances the accumulation of the vertical aberration and the field curvature accumulated by the relay system; the glass cemented lens with multiple dispersion coefficients is used to correct the axial chromatic aberration and the vertical chromatic aberration, the field curvature and the distortion caused by the large relative aperture from the entire white light waveband to the fluorescent waveband,
[0067] The relay lens system not only effectively reduces the vertical chromatic aberration and the field curvature caused by the large relative aperture, reduces the design difficulty of the objective, but also effectively compresses the diameter of the entire relay system,
[0068] The eyepiece system ensures that the pupil of the adapter is matched without affecting the image quality under the condition that the F number of the whole optical system is matched, when received by the human eye, the eye can be most relaxed, long-time use is ensured, and visual fatigue is not caused, the adapter can be used for pupil matching in the future, and imaging is performed on the image sensor, and then converted to the display screen, which is more convenient for medical staff to observe,
[0069] In conclusion, the endoscope optical system is a large field system, two negative focal length lenses are used in the objective lens system, the large field angle beam angle is well compressed, the objective lens diameter size and distortion are well controlled, the four cemented lenses are used for controlling the large aperture chromatic aberration, field curvature and diameter, the whole optical system is well controlled in the large relative aperture condition, the overall diameter size meets the requirements.
[0070] Meanwhile, the endoscope optical system realizes the entrance pupil diameter 0.74mm, the exit pupil diameter 5mm, the central angle resolution 18C / °, the distortion less than 5%, the field angle ≥80° and the diameter not greater than 6.6mm in the wavelength range 0.45-0.86um, and can realize white light wavelength band and fluorescence wavelength band super high definition low distortion imaging.
[0071] Based on the above ideal embodiments of the utility model, through the above description, relevant staff can make various changes and modifications without deviating from the technical idea of the utility model. The technical scope of the utility model is not limited to the content in the specification, and must be determined according to the scope of claims.
Claims
1. An optical system of an ultra-high-definition rigid endoscope, comprising, in sequence along the direction of light propagation, an objective lens system (1), a relay lens system (2) and an ocular lens system (3), the relay lens system (2) being located between the objective lens system (1) and the ocular lens system (3), the objective lens system (1) being of a reverse telephoto structure, The relay mirror system (2) comprises n groups of relay mirror groups, each group of relay mirror groups being a double-telecentric structure, and the relay mirror group is composed of two four-cemented-rod mirror pairs arranged symmetrically, wherein, n being an odd number, the ocular lens system (3) being of an object-side telecentric structure, characterized in that: the objective lens system (1) comprises, in sequence along the direction of light propagation, a sapphire protective lens (11), a negative-power lens (12), a plano-concave negative-power lens (13), a prism or a turning prism (14), a first positive-power triplet (15), a negative-power triplet (16), a negative-power doublet (17) and a first positive-power lens (18), the convex surface of the negative-power lens (12) being located on the inner side of the sapphire protective lens (11), and the concave surface of the negative-power lens (12) being cemented with the plane of the plano-concave negative-power lens (13), the prism or the turning prism (14) being located between the concave surface of the plano-concave negative-power lens (13) and the plane of the first positive-power triplet (15), the convex surface of the first positive-power triplet (15) being arranged adjacent to the convex surface of one side of the negative-power triplet (16), the convex surface of the other side of the negative-power triplet (16) being arranged adjacent to the convex surface of one side of the negative-power doublet (17), and the concave surface of the other side of the negative-power doublet (17) being close to the convex surface of one side of the first positive-power lens (18), the convex surface of the other side of the first positive-power lens (18) being located on one side of an n-group relay lens group, and the ocular lens system (3) being located on the other side of the n-group relay lens group.
2. The ultra-high definition rigid endoscope optical system of claim 1, wherein: the ocular lens system (3) comprises, in sequence along the direction of light propagation, a second positive-power triplet (31), a second positive-power lens (32), a positive-power doublet (33) and a sapphire lens (34), the second positive-power triplet (31) being located between the other side of the n-group relay lens group and the convex surface of one side of the second positive-power lens (32), the convex surface of the other side of the second positive-power lens (32) being adjacent to the convex surface of one side of the positive-power doublet (33), and the concave surface of the other side of the positive-power doublet (33) being adjacent to the sapphire lens (34).
3. The ultra-high definition rigid endoscope optical system of claim 1, wherein: the first positive-power triplet (15) is cemented as a whole by a first lens (151), a second lens (152) and a third lens (153), the plane of the first lens (151) being located on one side of the prism or the turning prism (14), the convex surface of the first lens (151) being cemented with the concave surface of one side of the second lens (152), the concave surface of the other side of the second lens (152) being cemented with the convex surface of one side of the third lens (153), and the convex surface of the other side of the third lens (153) being arranged adjacent to the convex surface of one side of the negative-power triplet (16).
4. The ultra-high definition rigid endoscope optical system of claim 1, wherein: The negative power triple cemented lens (16) is cemented by a fourth lens (161), a fifth lens (162) and a sixth lens (163), the concave surface on the two sides of the fifth lens (162) is respectively cemented with the convex surface on one side of the fourth lens (161) and the convex surface on one side of the sixth lens (163), the convex surface on the other side of the fourth lens (161) is close to the convex surface on the other side of the first positive power triple cemented lens (15), and the convex surface on the other side of the sixth lens (163) is close to the convex surface on one side of the negative power double cemented lens (17).
5. The ultra-high definition rigid endoscope optical system of claim 1, wherein: The negative power double cemented lens (17) is cemented by a seventh lens (171) and an eighth lens (172), the convex surface on one side of the seventh lens (171) is cemented with the convex surface on the other side of the negative power triple cemented lens (16), the convex surface on the other side of the seventh lens (171) is cemented with the concave surface on one side of the eighth lens (172), and the concave surface on the other side of the eighth lens (172) is close to the convex surface on one side of the first positive power lens (18).
6. The ultra-high definition rigid endoscope optical system of claim 1, wherein: The four-cemented rod lens is cemented by a convex lens (21), a meniscus rod lens (22), a double-concave lens (23) and a double-convex lens (24), the two sides of the meniscus rod lens (22) are respectively cemented with the convex surface on one side of the convex lens (21) and the concave surface on one side of the double-concave lens (23), and the concave surface on the other side of the double-concave lens (23) is cemented with the convex surface on one side of the double-convex lens (24).
7. The ultra-high definition rigid endoscope optical system of claim 2, wherein: The second positive power triple cemented lens (31) is cemented by a ninth lens (311), a tenth lens (312) and an eleventh lens (313), the two sides of the tenth lens (312) are respectively cemented with the convex surface of the ninth lens (311) and the convex surface on one side of the eleventh lens (313), the convex surface on the other side of the eleventh lens (313) is adjacent to the convex surface on one side of the second positive power lens (32), the positive power double cemented lens (33) is cemented by a twelfth lens (331) and a thirteenth lens (332), the concave surface of the twelfth lens (331) is cemented with the convex surface of the thirteenth lens (332), and the convex surface on the other side of the second positive power lens (32) is adjacent to the convex surface of the twelfth lens (331).
8. The ultra-high definition rigid endoscope optical system of claim 1, wherein: The prism or turning prism (14) and the first positive focal power triad lens (15) are provided with a first aperture stop, and the refractive index of the prism or turning prism (14) is 1.9≤n≤2.1; the prism or turning prism (14) and the flat-concave negative focal power lens (13) are glued into one body by low refractive index epoxy resin glue, and the refractive index of the epoxy resin glue is n 胶水 ≤1.
6.
9. The ultra-high definition rigid endoscope optical system of claim 1, wherein: The combined focal power of the negative power lens (12) and the plano-concave negative power lens (13) is between -0.55 and -0.4, while the ratio of their combined focal lengths f1 / f 物镜 satisfies -1.9 < f1 / f 物镜 物镜 is the focal length of the objective system (1). 10. The ultra-high definition rigid endoscope optical system of claim 1, wherein: In the objective system (1): The first positive power triplet (15) has a focal length f2 which satisfies 2.5 < f2 / f 物镜 < 8.5, The negative power tri-concave mirror (16) has a focal length f3 that satisfies -42≤f3 / f 物镜 ≤-10, The negative power doublet (17) has a focal length f4 that satisfies -200 ≤ f4 / f 物镜 ≤ -60, said first positive power lens (18) having a focal length f5 satisfying 3.5 ≤ f5 / f 物镜 ≤ 12, wherein f 物镜 is the focal length of the objective system (1).