Endoscope and its rod system

Abstract

An endoscope (20) and a rod lens system (10) thereof. The rod lens system (10) comprises: a first lens group (11), an aperture (12) and a second lens group (13). The first lens group (11) and the second lens group (13) are identical and symmetrically arranged relative to the aperture (12). The first lens group (11) and the second lens group (13) both comprise a first lens (111), a second lens (112) and a third lens (113) which are fixedly connected. The first lens (111) is a long rod lens with positive focal power, the second lens (112) is a lens with positive focal power, and the third lens (113) has negative focal power.

Description

Technical Field

[0001] The present application relates to the technical field of optical systems, and in particular to an endoscope and a rod mirror system thereof. Background Art

[0002] At present, endoscopes are increasingly used as medical equipment, especially in minimally invasive surgery. In addition, near-infrared imaging commonly used in hard endoscope surgery often uses intravenous vascular contrast agents (Indocyanine Green, ICG) to identify tissue structures during surgery. To support fluorescence imaging, it is necessary to provide an endoscope that can clearly image both conventional white light images and near-infrared fluorescence images.

[0003] However, the rod mirror system in the endoscope currently on the market cannot correct the axial chromatic aberration of near-infrared and white light at the same time, because general endoscopes have multiple groups of rod mirror systems, and the axial chromatic aberration will be multiplied, which ultimately leads to the infrared and white light images not being clear at the same time during the operation, and can only be observed in time, that is, refocusing is required when switching between infrared and white light images. In order to correct the axial chromatic aberration of infrared and white light, the existing rod mirror system design is too complicated, and many glued lenses are used. For glued lenses, the more glued elements there are, the more difficult it is to control the eccentricity, and the eccentricity is closely related to the image quality of the entire lens. Therefore, it is necessary to provide a wide-spectrum rod mirror system with low processing difficulty, high image quality, and the ability to simultaneously and clearly image in the visible light and near-infrared light ranges. Summary of the invention

[0004] Based on this, the present application provides an endoscope and a rod mirror system thereof, so that the user can simultaneously obtain clear images in the visible light and near-infrared light ranges without making any adjustments.

[0005] In one aspect, the present application provides a rod lens system, the rod lens system comprising: a first lens group, an aperture, and a second lens group arranged in sequence from the object side to the image side, the first lens group and the second lens group being identical and symmetrically arranged relative to the aperture;

[0006] The first lens group and the second lens group each include a first lens, a second lens and a third lens, the first lens is a long rod lens with positive optical power, the second lens is a lens with positive optical power, and the third lens is a lens with negative optical power;

[0007] The first lens, the second lens and the third lens are fixedly connected, the first lens is farther from the aperture than the second lens and the third lens, and the third lens is closer to the aperture than the first lens and the second lens.

[0008] On the other hand, the present application also provides an endoscope, the endoscope comprising:

[0009] The endoscope body includes a camera interface, a light source interface, an outer sleeve and an inner sleeve, wherein the camera interface is used to connect to the camera device, the light source interface is used to connect to the light source device, and the inner sleeve is sleeved on the inner side of the outer sleeve;

[0010] A light guide assembly, disposed between the outer sleeve and the inner sleeve, and used for transmitting the light generated by the light source device received through the light source interface to the observation body;

[0011] An eyepiece assembly, disposed in the inner sleeve and close to the camera interface;

[0012] An objective lens assembly is disposed in the inner sleeve and close to the insertion end of the endoscope body;

[0013] at least one rod lens system disposed in the inner sleeve and between the eyepiece lens assembly and the objective lens assembly;

[0014] The rod lens system includes: a first lens group, an aperture and a second lens group arranged in sequence from the object side to the image side; the first lens group and the second lens group are identical and symmetrically arranged relative to the aperture; the first lens group and the second lens group both include a first lens, a second lens and a third lens, the first lens is a long rod lens with positive focal power, the second lens is a lens with positive focal power, and the third lens is a lens with negative focal power; the first lens, the second lens and the third lens are fixedly connected, the first lens is farther from the aperture than the second lens and the third lens, and the third lens is closer to the aperture than the first lens and the second lens.

[0015] The embodiment of the present application provides an endoscope and a rod mirror system thereof, the rod mirror system comprising two identical first lens groups and second lens groups symmetrically arranged relative to the aperture, the two lens groups each comprising a first lens, a second lens and a third lens fixedly connected, the first lens being a long rod lens with positive optical power, the second lens being a lens with positive optical power, and the third lens being a lens with negative optical power. It can be seen that the rod mirror system has a simple structure and is easy to process, and at the same time, by utilizing two symmetrically arranged lens groups and a lens combination with specific parameters in the lens group, chromatic aberration can be effectively reduced, and clear imaging can be achieved simultaneously in the visible light and near-infrared light ranges.

[0016] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 is a structural schematic diagram of a rod mirror system provided in one embodiment of the present application;

[0019] Figure 2 is a structural schematic diagram of a rod mirror system provided in one embodiment of the present application;

[0020] Figure 3 yes Figure 1 Schematic diagram of axial chromatic aberration of the rod mirror system in ;

[0021] Figure 4 is a structural schematic diagram of a rod mirror system provided in one embodiment of the present application;

[0022] Figure 5 yes Figure 4 Schematic diagram of axial chromatic aberration of the rod mirror system in ;

[0023] Figure 6 is a structural schematic diagram of a rod mirror system provided in one embodiment of the present application;

[0024] Figure 7 yes Figure 6 Schematic diagram of axial chromatic aberration of the rod mirror system in ;

[0025] Figure 8 is a structural schematic diagram of a rod mirror system provided in one embodiment of the present application;

[0026] Fig. 9 yes Figure 8 Schematic diagram of axial chromatic aberration of the rod mirror system in ;

[0027] Fig.10 is a structural schematic diagram of a rod mirror system provided in one embodiment of the present application;

[0028] Fig.11 yes Fig.10 Schematic diagram of axial chromatic aberration of the rod mirror system in ;

[0029] Fig.12 is a structural schematic diagram of a rod mirror system provided in one embodiment of the present application;

[0030] Fig.13 yes Fig.12 Schematic diagram of axial chromatic aberration of the rod mirror system in ;

[0031] Fig.14It is a structural schematic diagram of an endoscope provided in another embodiment of the present application.

[0032] Description of main components and symbols:

[0033] 10. Rod mirror system; 11. First lens group; 12. Stop; 13. Second lens group; 111. First lens; 112. Second lens; 113. Third lens;

[0034] 20. Endoscope; 21. Endoscope body; 211. Outer sleeve; 212. Inner sleeve; 213. Camera interface; 214. Light source interface; 22. Light guide assembly; 221. Light cone; 222. Optical fiber; 23. Eyepiece assembly; 24. Objective lens assembly. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0036] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0037] With the development of science and medical technology, laparoscopic minimally invasive surgery has become increasingly popular. In hard laparoscopic surgery, tracing of key tissues can improve the success rate of surgery. Near-infrared imaging can trace the gallbladder and lymph node structures in deeper tissues, which is beneficial for morphological identification in conventional resection surgery or tumor surgery, and plays a role in precise positioning.

[0038] Near-infrared imaging commonly used in endoscopic surgery mostly uses intravenous vascular contrast agents (ICG). The contrast agent binds to plasma proteins and globulins, is quickly cleared from the bloodstream in normal tissues, metabolized by the liver, excreted in bile, and excreted from the body in its original form. Therefore, there will be a short-term accumulation of dye in areas such as the gallbladder, common hepatic duct, or lymph nodes in the body, which is conducive to the identification of tissue structures during surgery. Secondly, because the contrast agent is an infrared excitation dye, and the penetration depth of infrared light is deep, it is convenient to determine the deep tissue structure and avoid damage to key tissues during surgery. In addition, in tumor surgery, the contrast agent can be circulated from the tumor tissue through the lymphatic circulation and deposited in the sentinel lymph nodes connected to the tumor tissue, so as to achieve accurate sentinel lymph node positioning and avoid the harm of large-area lymph node dissection to patients.

[0039] To support fluorescence imaging, it is necessary to provide an endoscope that can clearly image both conventional white light (visible light) images and near-infrared fluorescence images. This type of endoscope includes an ICG hard tube endoscope. The following embodiments are described in detail using the ICG hard tube endoscope as an example.

[0040] Taking laparoscope as an example, the laparoscopes currently available on the market for ICG imaging have two main disadvantages:

[0041] (1) The rod mirror system cannot correct the axial chromatic aberration of near-infrared and white light at the same time. Because a general laparoscope has more than three rod mirror image transfer systems, the axial chromatic aberration will be magnified exponentially, which ultimately results in the infrared and white light images not being clear at the same time during the operation. They can only be observed in time, and refocusing is required when switching between infrared and white light images.

[0042] (2) The rod mirror system is too complicated to correct the axial chromatic aberration of infrared and white light. Chromatic aberration is one of the main aberrations that affect optical imaging. The ability of an optical lens to correct chromatic aberration under a certain optical focal length mainly depends on the dispersion characteristics of the glass. Since the dispersion characteristics of glass are in a discrete and discontinuous distribution, the usual practice is to glue together multiple glasses with different dispersion characteristics at a certain optical focal length to achieve the required dispersion performance. The more types of glass, the easier it is to correct the dispersion characteristics, but the higher the processing difficulty and cost. For glued lenses, too many glued elements will increase the difficulty of eccentricity control. There are generally more than 6 rod mirrors in a laparoscope, and their eccentricity is closely related to the image quality of the entire lens. Therefore, it is crucial to effectively reduce the number of glued elements in the rod mirror system when the axial chromatic aberration meets the chromatic aberration tolerance.

[0043] In order to clearly image both conventional white light images and near-infrared fluorescence images at the same time, the rigid tube microscope needs to use a rod mirror system that can reduce axial chromatic aberration. Since the rod mirror system of the present application can clearly image both conventional white light images and near-infrared fluorescence images at the same time, it is called a wide-spectrum rod mirror system.

[0044] See also Figure 1 , Figure 1 1 is a schematic diagram of the structure of a rod mirror system provided in one embodiment of the present application. The rod mirror system can effectively reduce the axial chromatic aberration of visible light and near-infrared light without any adjustment.

[0045] like Figure 1 As shown, the rod mirror system 10 includes: a first lens group 11, an aperture 12 and a second lens group 13. The first lens group 11, the aperture 12 and the second lens group 13 are arranged in sequence from the object side to the image side, and the first lens group 11 and the second lens group 13 are identical and symmetrically arranged relative to the aperture 12.

[0046] The first lens group 11 and the second lens group 13 are completely identical and symmetrical with respect to the aperture 12 .

[0047] The first lens group 11 includes a first lens 111 , a second lens 112 and a third lens 113 ; the second lens group 13 also includes a first lens 111 , a second lens 112 and a third lens 113 .

[0048] The first lens 111 is a rod lens with positive optical power, the second lens 112 is a lens with positive optical power, and the third lens 113 is a lens with negative optical power.

[0049] The first lens 111, the second lens 112 and the third lens 113 are fixedly connected. In the rod mirror system 10, the first lens 111 is farther from the aperture 12 than the second lens 112 and the third lens 113, and the third lens 113 is closer to the aperture 12 than the first lens 111 and the second lens 112.

[0050] It should be noted that the fixed connection between the lenses in the embodiments of the present application may specifically be a gluing connection, and the gluing connection is taken as an example for description below.

[0051] Specifically, the second lens 112 is located between the first lens 111 and the third lens 113. The aperture 12 is located at the center of the first lens group 11 and the second lens group 13. Optionally, the aperture 12 is an aperture aperture.

[0052] It can be understood that the first lens group 11, the aperture 12 and the second lens group 13 are arranged in sequence along the optical axis from the object side to the image side.

[0053] It should be noted that the diameters of the first lens 111, the second lens 112 and the third lens 113 are the same, and in some embodiments, they may be different. In practical applications, the first lens 111, the second lens 112 and the third lens 113 are all made of glass, and of course other materials that can be used as lenses can also be used.

[0054] The rod mirror system provided in the embodiment of the present application uses two symmetrically arranged lens groups and a combination of three lenses with specific parameters in the lens group to simultaneously perform high correction on the axial chromatic aberration of visible spectrum and near-infrared spectrum images, and can ensure parfocal imaging within the visible light and near-infrared light bands, avoiding the problem of refocusing when observing infrared and white light images. At the same time, the types of glued mirrors include 3 categories, which reduces the processing difficulty and cost requirements, but the axial chromatic aberration is not affected, and can still meet normal clinical requirements.

[0055] In some embodiments, the rod mirror system can be used in the visible light and near infrared light range, and the specific application spectrum range is 420nm to 900nm. That is, the wavelength range covers 420nm to 900nm, and there is no need to refocus during imaging, which is more convenient to use.

[0056] In some embodiments, in order to improve the image transmission capability of the rod mirror system, the rod mirror system 10 meets the following conditions:

[0057] 18≤T / D≤22 (1)

[0058] In formula (1), T is the conjugate distance of the object-image conjugate plane of the rod lens system 10, and D is the diameter of the long rod lens.

[0059] Because the main function of the rod mirror system is to efficiently transmit images within a limited physical aperture, if the object-image conjugate distance of the rod mirror system is too long, the numerical aperture of the light beam will inevitably be reduced under the rated lens diameter. If the object-image conjugate distance is too short, the number of rod mirror groups required within a specific physical length will increase, affecting the light transmission efficiency and cost. Therefore, the rod mirror system is limited by formula (1) to improve the image transmission capability of the rod mirror system and reduce the cost.

[0060] In some embodiments, to ensure the imaging quality of the rod mirror system, the first lens 111 satisfies the following conditions:

[0061] n1≤1.63 (2)

[0062] In formula (2), n1 is the refractive index of the first lens 111.

[0063] In addition, the first lens 111 is a long rod lens, and its spectral transmittance will affect the color perception of the entire lens when used for observation. Glass with too high a refractive index has a strong absorption rate for blue light, making the imaging effect of the entire lens yellow. Therefore, when selecting materials for the long rod lens, low refractive index materials with high blue light transmittance are often used.

[0064] Therefore, the first lens 111 is a long rod lens, and the material of the long rod lens is a low refractive index material with high blue light transmittance, and the refractive index satisfies formula (2), thereby further improving the imaging quality.

[0065] In some embodiments, in order to reduce the chromatic aberration of the rod mirror system and broaden the use range of the spectrum, the material of the second lens 112 is anomalous dispersion glass, and the second lens 112 meets the following conditions:

[0066] V2≥70 (3)

[0067] ΔP2 ≥ 0.025 (4)

[0068] Wherein, v2 is the Abbe number of the second lens 112 , and ΔP2 is the local dispersion of the second lens 112 .

[0069] Specifically, the material of the second lens 112 is an anomalous dispersion glass that deviates from the pv standard line, which is very useful for correcting the secondary spectrum and can even make the axial chromatic aberration present an S-shaped curve, thereby greatly reducing the axial chromatic aberration and widening the use range of the spectrum.

[0070] In some embodiments, in order to improve the imaging quality, the third lens 113 satisfies the following conditions:

[0071] n3≥1.55 (5)

[0072] V3≥40 (6)

[0073] Wherein, n3 is the refractive index of the third lens 113 , and V3 is the Abbe number of the third lens 113 .

[0074] The third lens 113 is a meniscus negative lens close to the aperture stop, and a high refractive index glass is selected, because the Pisval field curvature is related to ∑1 / nf, where n is the refractive index of the lens and f is the focal length of the lens. The negative lens is selected from a material with a high refractive index, which can effectively reduce the field curvature while satisfying the overall optical power. Therefore, the refractive index n3 and the Abbe number V3 of the third lens 113 are required to satisfy the requirements of formula (5) and formula (6). In addition, the field curvature of the rod mirror system can be effectively reduced, and the imaging quality of the rod mirror system can be improved.

[0075] In some embodiments, in order to reduce the difficulty of processing the rod mirror system and improve the imaging quality of the rod mirror system, the curvature radius of the mirror surface of the first lens 111 facing the aperture 12 and the mirror surface of the second lens 112 facing away from the aperture 12 are set to be the same; the curvature radius of the mirror surface of the second lens 112 facing the aperture 12 and the mirror surface of the third lens 113 facing away from the aperture 12 are set to be the same.

[0076] Optionally, the mirror surface of the first lens 111 facing away from the aperture 12 is a convex surface, and the mirror surface of the first lens 111 facing the aperture 12 is a concave surface or a plane.

[0077] Optionally, the second lens 112 is a biconvex lens or a plano-convex lens, that is, the mirror surface of the second lens 112 facing away from the aperture 12 is a convex surface or a plane surface, and the mirror surface of the second lens 112 facing the aperture 12 is a convex surface.

[0078] Optionally, the third lens 113 is a meniscus lens.

[0079] In other embodiments, at least one piece of plane glass may be glued between the first lens 111 and the second lens 112, or at least one piece of plane glass may be glued between the second lens 112 and the third lens 113. Since the plane glass does not change the path of the light, the rod mirror structure in these embodiments can still achieve the same technical effect as the above embodiment, and can further reduce the difficulty of processing.

[0080] It can be seen that the rod mirror system of the above embodiment is easy to process and has low cost. At the same time, the axial chromatic aberration of visible spectrum and near-infrared spectrum images can be highly corrected at the same time. When used in an endoscope, it can ensure parfocal imaging within the visible light and near-infrared light bands, avoiding the problem of refocusing when observing infrared and white light images, and facilitating clinical use.

[0081] The following table and accompanying drawings provide several different embodiments of specific numerical configurations of rod mirror systems and corresponding axial chromatic aberration effects.

[0082] In each table, code n corresponds to the surface number in the rod mirror system, surface code S represents the aperture stop; R (unit: mm) represents the radius of curvature of each surface of the optical component; L (unit: mm) represents the thickness of the optical component or the interval between the optical components; N(d) represents the refractive index at the d-line (the d-line is a wavelength of 588 nm); v(d) represents the Abbe number at the d-line, It represents the local dispersion of g light and f light. Among them, the aperture D is the diameter of the long rod lens, and the object-image conjugate distance T is the conjugate distance of the object-image conjugate plane of the rod lens system, and the unit is millimeter (mm).

[0083] Among them, the surface labels in the rod mirror system are as follows: Figure 2 As shown, O represents the object plane, S represents the aperture, and I represents the image plane.

[0084] Example 1, Table 1 and Table 2 show the specific numerical configuration of the rod mirror system. The rod mirror system having the numerical configuration of Table 1 and Table 2 is as follows: Figure 1 shown. Figure 3 The axial chromatic aberration of the rod mirror system for the ICG rigid tube mirror of Example 1 is shown.

[0085] Table 1

[0086]

[0087]

[0088] Conjugate distance T 111 Clearance D 6

[0089] Example 2, Table 3 and Table 4 show the specific numerical configuration of the rod mirror system. The rod mirror system having the numerical configuration of Table 3 and Table 4 is as follows Figure 4 shown. Figure 5 The axial chromatic aberration of the rod mirror system for the ICG rigid tube mirror of Example 2 is shown.

[0090] Table 3

[0091]

[0092] Conjugate distance T 116 Clearance D 6

[0093] Example 3, Table 5 and Table 6 show the specific numerical configuration of the rod mirror system. The rod mirror system having the numerical configuration of Table 5 and Table 6 is as follows Figure 6 shown. Figure 7 The axial chromatic aberration of the rod mirror system for the ICG rigid tube mirror of Example 3 is shown.

[0094] Table 5

[0095]

[0096] Conjugate distance T 116 Clearance D 6

[0097] Example 4, Table 7 and Table 8 show the specific numerical configuration of the rod mirror system. The rod mirror system having the numerical configuration of Table 7 and Table 8 is as follows: Figure 8 shown. Fig. 9 The axial chromatic aberration of the rod mirror system for the ICG rigid tube mirror of Example 4 is shown.

[0098] Table 7

[0099]

[0100]

[0101] Conjugate distance T 116 Clearance D 6

[0102] Example 5, Tables 9 and 10 show the specific numerical configuration of the rod mirror system. The rod mirror system having the numerical configuration of Tables 9 and 10 is as follows: Fig.10 shown. Fig.11 The axial chromatic aberration of the rod mirror system for the ICG rigid tube mirror of Example 5 is shown.

[0103] Table 9

[0104]

[0105]

[0106] Conjugate distance T 116 Clearance D 6

[0107] Example 6, Table 11 and Table 12 show the specific numerical configuration of the rod mirror system. The rod mirror system having the numerical configuration of Table 11 and Table 12 is specifically as follows Fig.12 shown. Fig.13 The axial chromatic aberration of the rod mirror system for the ICG rigid tube mirror of Example 6 is shown.

[0108] Table 11

[0109]

[0110]

[0111] Conjugate distance T 116 Clearance D 6

[0112] See also Fig.14 , Fig.14 This is a schematic diagram of the structure of an endoscope provided by another embodiment of the present application. The endoscope can clearly image in the visible light and near-infrared light ranges, and can clearly image when switching from visible light to near-infrared light, or from near-infrared light to visible light, without any adjustment, thereby facilitating user use and meeting clinical medical requirements.

[0113] like Fig.14 As shown, the endoscope 20 includes an endoscope body 21 , a light guide assembly 22 , an eyepiece assembly 23 , an objective lens assembly 24 and a rod lens system 10 .

[0114] The endoscope body 21 includes an outer sleeve 211, an inner sleeve 212, a camera interface 213 and a light source interface 214. The inner sleeve 212 is sleeved on the inner side of the outer sleeve 211. The camera interface 213 is used to connect with a camera device, which is used to collect images of the observed object. The light source interface 214 is used to connect with a light source device, and is used to receive light generated by the light source device.

[0115] The light guide component 22 is disposed between the outer sleeve 211 and the inner sleeve 212 , and is used to transmit the light generated by the light source device received through the light source interface 214 to the observation object, so as to irradiate the light on the observation object for imaging.

[0116] The eyepiece assembly 23 is disposed in the inner sleeve 212 and is close to the camera interface 213. The objective lens assembly 24 is disposed in the inner sleeve 212 and is close to the insertion end of the endoscope body 21. The insertion end of the endoscope body 21 refers to the head of the insertion part inserted into the object to be detected (such as a human body). The rod mirror system 10 is also disposed in the inner sleeve and is located between the eyepiece assembly 23 and the objective lens assembly 24. The number of the rod mirror system 10 is at least one.

[0117] It should be noted that the rod mirror system 10 can be any one of the rod mirror systems in the above-mentioned embodiments; when the number of the rod mirror systems 10 is multiple, the multiple rod mirror systems 10 can of course also be a combination of the rod mirror systems provided by the above-mentioned different embodiments, or the multiple rod mirror systems 10 can all be the same rod mirror system.

[0118] For example, Fig.14 As shown, the endoscope 20 includes three rod mirror systems 10. A plurality of rod mirror systems 10 can effectively reduce axial chromatic aberration. Of course, other numbers of rod mirror systems are also possible.

[0119] In some embodiments, the light guide component 22 includes a light cone 221 and an optical fiber 222. The light cone 221 is fixedly connected to the optical fiber 222. One end of the light cone 221 corresponds to the light source interface 214, which is used to collect light generated by the light source device and couple the light into the optical fiber 222; the optical fiber 222 is used to transmit light to the observation object.

[0120] In some embodiments, in order to improve the imaging quality of the endoscope 20 so as to clearly observe the target object, the eyepiece assembly 23 includes a plurality of lens assemblies, and the objective lens assembly 24 may also include a plurality of lens assemblies.

[0121] It can be seen that the endoscope 20 using the rod mirror system in the embodiment of the present application can form images within the visible light and near-infrared light ranges. At the same time, when switching from visible light to near-infrared light or from near-infrared light to visible light, clear images can be formed without any adjustment, thereby facilitating user use and meeting clinical medical requirements.

[0122] The outer sleeve 211 and the inner sleeve 212 are both circular sleeves, and when the inner sleeve 212 is sleeved in the outer sleeve 211, the outer wall of the inner sleeve 212 can abut against the outer sleeve 211. It should be noted that the outer sleeve 211 and the inner sleeve 212 need to have an optical fiber channel.

[0123] It should be noted that, in the endoscope 20, the aperture in the rod mirror system 10 is a spacer aperture.

[0124] In other embodiments, at least one piece of flat glass may be glued between the first lens and the second lens, or at least one piece of flat glass may be glued between the second lens and the third lens in the rod mirror system 10. Since the flat glass does not change the path of the light, the rod mirror structure in these embodiments can still achieve the same technical effect as the above embodiment, and can reduce the difficulty of processing.

[0125] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. An endoscope, characterized in that: include: The endoscope body includes a camera interface, a light source interface, an outer sleeve and an inner sleeve, wherein the camera interface is used to connect to the camera device, the light source interface is used to connect to the light source device, and the inner sleeve is sleeved on the inner side of the outer sleeve; A light guide assembly, disposed between the outer sleeve and the inner sleeve, and used for transmitting the light generated by the light source device received through the light source interface to the observation body; An eyepiece assembly, disposed in the inner sleeve and close to the camera interface; An objective lens assembly is disposed in the inner sleeve and close to the insertion end of the endoscope body; at least one rod lens system disposed in the inner sleeve and between the eyepiece lens assembly and the objective lens assembly; The rod lens system comprises: a first lens group, an aperture, and a second lens group arranged in sequence from the object side to the image side; the first lens group and the second lens group are the same and are symmetrically arranged relative to the aperture; the first lens group and the second lens group both comprise a first lens, a second lens, and a third lens, the first lens is a long rod lens with positive focal power, the second lens is a lens with positive focal power, and the third lens is a lens with negative focal power; the first lens, the second lens, and the third lens are fixedly connected, the first lens is farther from the aperture than the second lens and the third lens, and the third lens is closer to the aperture than the first lens and the second lens; The spectral range of the rod mirror system is 420nm to 900nm, and the material of the second lens is anomalous dispersion glass, and the second lens meets the following conditions: V2≥70, ΔP2≥0.025 V2 is the Abbe number of the second lens, and ΔP2 is the local dispersion of the second lens.

2. The endoscope according to claim 1, characterized in that The light guide assembly includes a light cone and an optical fiber connected to the light cone; Wherein, the light cone is used to receive the light generated by the light source device and couple the light into the optical fiber; and the optical fiber is used to transmit the light to the observation object.

3. The endoscope according to any one of claims 1 to 2, characterized in that: Two adjacent lenses among the first lens, the second lens and the third lens are fixedly connected by gluing.

4. The endoscope according to any one of claims 1 to 2, characterized in that: The rod mirror system meets the following conditions: 18≤T / D≤22 Wherein, T is the conjugate distance of the object-image conjugate plane of the rod lens system, and D is the diameter of the long rod lens.

5. The endoscope according to any one of claims 1 to 2, characterized in that: The first lens meets the following conditions: n1≤1.63 Wherein, n1 is the refractive index of the first lens.

6. The endoscope according to any one of claims 1 to 2, characterized in that: The third lens meets the following conditions: n3≥1.55, V3≥40 Wherein, n3 is the refractive index of the third lens, and V3 is the Abbe number of the third lens.

7. The endoscope according to any one of claims 1 to 2, characterized in that: The mirror surface of the first lens facing away from the aperture is a convex surface, and the mirror surface of the first lens facing the aperture is a concave surface or a plane.

8. The endoscope according to any one of claims 1 to 2, characterized in that: The second lens is a biconvex lens or a plano-convex lens.

9. The endoscope according to any one of claims 1 to 2, characterized in that: The third lens is a meniscus lens.

10. The endoscope according to any one of claims 1 to 2, characterized in that: It also includes at least one piece of flat glass disposed between the first lens and the second lens, and / or at least one piece of flat glass disposed between the second lens and the third lens.

11. A rod mirror system, characterized in that: include: A first lens group, an aperture stop, and a second lens group are sequentially arranged from the object side to the image side, wherein the first lens group and the second lens group are identical and symmetrically arranged relative to the aperture stop; The first lens group and the second lens group each include a first lens, a second lens and a third lens, the first lens is a long rod lens with positive optical power, the second lens is a lens with positive optical power, and the third lens is a lens with negative optical power; The first lens, the second lens and the third lens are fixedly connected, the first lens is farther from the aperture than the second lens and the third lens, and the third lens is closer to the aperture than the first lens and the second lens; The spectral range of the rod mirror system is 420nm to 900nm, and the material of the second lens is anomalous dispersion glass, and the second lens meets the following conditions: V2≥70, ΔP2≥0.025 V2 is the Abbe number of the second lens, and ΔP2 is the local dispersion of the second lens.

12. The rod mirror system according to claim 11, characterized in that: Two adjacent lenses among the first lens, the second lens and the third lens are fixedly connected by gluing.

13. The rod mirror system according to any one of claims 11 to 12, characterized in that: The rod mirror system meets the following conditions: 18≤T / D≤22 Wherein, T is the conjugate distance of the object-image conjugate plane of the rod lens system, and D is the diameter of the long rod lens.

14. The rod mirror system according to any one of claims 11 to 12, characterized in that: The first lens meets the following conditions: n1≤1.63 Wherein, n1 is the refractive index of the first lens.

15. The rod mirror system according to any one of claims 11 to 12, characterized in that: The third lens meets the following conditions: n3≥1.55, V3≥40 Wherein, n3 is the refractive index of the third lens, and V3 is the Abbe number of the third lens.

16. The rod mirror system according to any one of claims 11 to 12, characterized in that: The mirror surface of the first lens facing away from the aperture is a convex surface, and the mirror surface of the first lens facing the aperture is a concave surface or a flat surface.

17. The rod mirror system according to any one of claims 11 to 12, characterized in that: The second lens is a biconvex lens or a plano-convex lens.

18. The rod mirror system according to any one of claims 11 to 12, characterized in that: The third lens is a meniscus lens.

19. The rod mirror system according to any one of claims 11 to 12, characterized in that: It also includes at least one piece of flat glass disposed between the first lens and the second lens, and / or at least one piece of flat glass disposed between the second lens and the third lens.

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