Endoscope and diaphragm of endoscope

Abstract

The present invention relates to an endoscope. Provided are an endoscope and a diaphragm of the endoscope. The endoscope comprises: a tube unit, which is configured to be inserted into a part to be observed; and an optical imaging system, which is arranged in the tube unit and comprises a diaphragm, wherein a through hole is formed in the radial middle portion of the diaphragm, and the through hole forms a first light-passing area; the diaphragm is further provided with a second light-passing area located on a radial outer side of the first light-passing area, and the second light-passing area is configured to absorb light within a first wavelength interval and allow light within a second wavelength interval to pass therethrough; and the light within the first wavelength interval is the light reflected after a light source of the endoscope irradiates the part to be observed, and the light within the second wavelength interval is fluorescence generated by the light source of the endoscope irradiating fluorescent dye at the part to be observed. The present invention mainly solves the technical problem of contradiction between the depth of field of visible light and the signal strength of fluorescence in the endoscope.

Description

Endoscope and aperture of endoscope Technical Field

[0001] The present invention relates to an endoscope, in particular to an endoscope capable of simultaneously imaging visible light and fluorescence. Background Art

[0002] In common fluorescence navigation surgeries, the endoscope needs to be able to simultaneously image visible light (also known as white light in the industry, typically covering a wavelength range of approximately 400 to 700 nanometers) and fluorescence (typically in the near-infrared band, typically covering a wavelength range of approximately 700 to 1300 nanometers). Visible light can provide doctors with clear images within a certain depth of field, while fluorescence can help doctors identify deeper tissue structures. Due to the deep penetration depth of infrared light, fluorescent dyes such as ICG (indocyanine green) and methylene blue (also known as infrared excitation dyes) are currently used as contrast agents to achieve fluorescence imaging. These dyes can produce infrared fluorescence when excited. However, the detectable signal intensity of infrared light is relatively weak.

[0003] Endoscopes are equipped with diaphragms to limit the light beam, especially the aperture diaphragm. The aperture diaphragm limits the amount of light entering the optical system, and its size also determines the intensity of the light signal and the depth of field effect. The larger the aperture diaphragm, the stronger the fluorescence signal intensity, but the depth of field of the visible light will be reduced, that is, the signal intensity and depth of field are mutually exclusive.

[0004] Therefore, how to maximize the intensity and sensitivity of the fluorescence signal without affecting the depth of field of the visible light image is a major pain point in the field of endoscopy. Technical issues

[0005] The present invention mainly solves the technical problem of the contradiction between the depth of field of visible light and the signal intensity of fluorescence in an endoscope. Technical Solutions

[0006] In a first aspect, the present invention provides an endoscope.

[0007] An endoscope comprising:

[0008] a tubular unit, the tubular unit being used to be inserted into a part to be observed;

[0009] and an optical imaging system, the optical imaging system being disposed in the tube unit, the optical imaging system comprising an aperture;

[0010] A through hole is provided in the radial middle portion of the aperture, and the through hole forms a first light-transmitting area; the aperture also has a second light-transmitting area located radially outside the first light-transmitting area, and the second light-transmitting area is used to absorb light in the first wavelength range and allow light in the second wavelength range to pass through; the light in the first wavelength range is the light reflected after the light source of the endoscope is irradiated on the part to be observed, and the light in the second wavelength range is the fluorescence generated by the fluorescent dye irradiated on the part to be observed by the light source of the endoscope.

[0011] In a technical solution, the diaphragm is arranged at an aperture diaphragm position and / or an aperture diaphragm object-image conjugate position of the optical imaging system.

[0012] In one technical solution, the endoscope is a rigid tube endoscope, and the endoscope includes a rod mirror assembly for image rotation, the rod mirror assembly includes two rod mirrors in a pair, and the aperture is arranged between the two rod mirrors in the pair.

[0013] In one technical solution, at least a portion of the end faces of the two paired rod mirrors close to each other at one end is a convex spherical surface, and at least a portion of the convex spherical surface is embedded in the through hole in the middle of the aperture.

[0014] In one technical solution, the endoscope is a flexible endoscope or an electronic endoscope, and the aperture is located on the objective lens of the flexible endoscope or the electronic endoscope.

[0015] In a second aspect, the present invention provides another endoscope.

[0016] An endoscope comprising:

[0017] a tubular unit, the tubular unit being used to be inserted into a part to be observed;

[0018] and an optical imaging system, the optical imaging system being disposed in the tube unit, the optical imaging system comprising an aperture;

[0019] The aperture has a first light-transmitting area located in the radial middle thereof and a second light-transmitting area located radially outside the first light-transmitting area; the first light-transmitting area allows light located in the first wavelength range and the second wavelength range to pass through, and the second light-transmitting area is used to absorb light located in the first wavelength range and allow light located in the second wavelength range to pass through; the light in the first wavelength range is light reflected after the light source of the endoscope is irradiated on the part to be observed, and the light in the second wavelength range is fluorescence generated by the fluorescent dye irradiated on the part to be observed by the light source of the endoscope.

[0020] In a third aspect, the present invention provides yet another endoscope.

[0021] An endoscope comprising:

[0022] a tubular unit, the tubular unit being used to be inserted into a part to be observed;

[0023] and an optical imaging system, the optical imaging system being disposed in the tube unit, the optical imaging system comprising an aperture;

[0024] A through hole is provided in the radial middle portion of the aperture, and the through hole forms a first light-transmitting area; the aperture also has a second light-transmitting area located radially outside the first light-transmitting area, and the second light-transmitting area is used to absorb light in the first wavelength range and allow light in the second wavelength range to pass through; the wavelength value of the first wavelength range is smaller than the wavelength value of the second wavelength range.

[0025] In a technical solution, the physical thickness d of the aperture is configured to be d>0.3 mm.

[0026] In one technical solution, the light in the first wavelength range is visible light, and the visible light transmittance of the second light-transmitting area is no more than 1%.

[0027] In one technical solution, the light in the second wavelength range is near-infrared light, and the near-infrared light transmittance of the second light-transmitting area is not less than 50%.

[0028] In one technical solution, the outer diameter of the second light-transmitting area is more than 1.2 times the outer diameter of the first light-transmitting area.

[0029] In a technical solution, the first light-transmitting area is made of a homogeneous material, and / or the second light-transmitting area is made of a homogeneous material.

[0030] In one technical solution, the material of the first light-transmitting area is one of acrylonitrile-butadiene-styrene copolymer, polymethyl methacrylate, polyethylene terephthalate plastic, polyetherimide and polycarbonate;

[0031] And / or, the material of the second light-transmitting area is one of acrylonitrile-butadiene-styrene copolymer, polymethyl methacrylate, polyethylene terephthalate plastic, polyetherimide and polycarbonate.

[0032] In one technical solution, the high temperature resistance of the aperture is not less than 110 degrees Celsius.

[0033] In one technical solution, the aperture has a third light-transmitting area, and the third light-transmitting area is located between the first light-transmitting area and the second light-transmitting area and / or radially outside the second light-transmitting area.

[0034] In a fourth aspect, the present invention provides an aperture for an endoscopic optical imaging system.

[0035] An aperture for an endoscope optical imaging system, comprising:

[0036] a first light-transmitting area, the first light-transmitting area being located in the radial middle of the aperture;

[0037] and a second light-transmitting area, the second light-transmitting area being located radially outward of the first light-transmitting area;

[0038] The first light-transmitting area allows light in the first wavelength range and the second wavelength range to pass through, and the second light-transmitting area is used to absorb light in the first wavelength range and allow light in the second wavelength range to pass through; the light in the first wavelength range is the light reflected after the light source of the endoscope illuminates the part to be observed, and the light in the second wavelength range is the fluorescence generated by the fluorescent dye of the part to be observed illuminated by the light source of the endoscope, and the wavelength value of the first wavelength range is smaller than the wavelength value of the second wavelength range.

[0039] In one technical solution, a through hole is provided in the radial middle portion of the aperture, and the first light-transmitting area is formed by the through hole. Beneficial effects

[0040] Beneficial effects of the present invention:

[0041] According to the above-mentioned endoscope, by arranging a first light-transmitting area (which can be a through hole) located in the radial middle part of the aperture and a second light-transmitting area located radially outside the first light-transmitting area, and configuring the second light-transmitting area to absorb light in the first wavelength range and allow light in the second wavelength range with a wavelength value higher than the first wavelength range to pass through, it is equivalent to setting a smaller aperture for light with a relatively small wavelength value (such as light reflected after the light source of the endoscope illuminates the part to be observed), thereby achieving a large depth of field, and at the same time setting a larger aperture for light with a relatively large wavelength value (such as fluorescence generated by the fluorescent dye of the part to be observed illuminated by the light source of the endoscope), thereby achieving a stronger signal intensity, thereby solving the technical problem of the contradiction between the depth of field of visible light and the signal intensity of fluorescence in the endoscope; at the same time, the second light-transmitting area uses light absorption to limit the passage of light in the first wavelength range, and a coating solution may not be adopted, so a simpler process can be adopted, which is easy to process and has lower cost, and there will be no problem of oxidation of the coating, and the stability is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] FIG1 is a schematic diagram of an optical system in one embodiment of an endoscope;

[0043] FIG2 is a partial enlarged view of point A in FIG1 ;

[0044] FIG3 is a schematic diagram showing the working principle of the aperture of the endoscope of the present invention;

[0045] FIG4 is a graph showing the light transmittance of the aperture stop in FIG1 ;

[0046] Figure 5 shows the experimental comparison of ICG fluorescence with the aperture stop in Figure 1. The left and right experimental figures use the aperture stop as the single variable.

[0047] FIG6 is a longitudinal sectional view of another embodiment of the aperture of the endoscope according to the present invention when cut along the axis.

[0048] List of feature names corresponding to the reference numerals in the figure:

[0049] 100, aperture stop; 110, first light-transmitting area; 120, second light-transmitting area;

[0050] 210, objective lens unit; 220, image transfer unit; 221, rod lens assembly; 222, rod lens; 223, convex spherical surface; 230, eyepiece unit. Modes for Carrying Out the Invention

[0051] The present invention will be further described in detail below by means of specific embodiments in conjunction with the accompanying drawings. Similar elements in different embodiments are numbered with associated similar elements. In the following embodiments, many detailed descriptions are provided to enable the present application to be better understood. However, those skilled in the art will readily appreciate that some of the features may be omitted in different circumstances, or may be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification. This is to avoid the core portion of the present application being overwhelmed by excessive descriptions, and for those skilled in the art, it is not necessary to describe these related operations in detail. They will fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0052] In addition, the features, operations, or characteristics described in the specification may be combined in any appropriate manner to form various embodiments. Furthermore, the steps or actions in the method description may be reordered or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various sequences in the specification and drawings are provided solely for the purpose of clearly describing a particular embodiment and are not intended to be mandatory, unless otherwise specified.

[0053] Component numbers used herein, such as "first" and "second," are used solely to distinguish the components being described and do not convey any sequential or technical meaning. References to "connection" and "coupling" herein, unless otherwise specified, include both direct and indirect connections (couplings).

[0054] An aperture is an entity that limits the light beam in an optical system. It can be the edge of a lens, a frame, or a specially designed screen with holes. In an optical system, an aperture can limit the light beam or restrict the field of view (the range of the image). An aperture is present in all optical systems. When viewing the aperture or its image from an object point, the one with the smallest angle determines the aperture of the optical system. An aperture limits the amount of light entering an optical system. Simply put, an aperture is like a window; by adjusting its size, you can control the amount of light entering the system. The size of the aperture affects the brightness and depth of field of the image. A larger aperture allows more light to enter the optical system, resulting in a brighter image and a shallower depth of field (i.e., a smaller range of foreground and background in focus). A smaller aperture allows less light to enter the system, resulting in a darker image and a deeper depth of field (i.e., a larger range of foreground and background in focus).

[0055] During endoscopic imaging, the light at the site to be observed includes both reflected light from the endoscope's light source and the fluorescent light produced by laser irradiation of the fluorescent dye in the site to be observed. Because both the reflected light and the fluorescent light produced by excitation must pass through the endoscope's optical system, the design of the optical system must consider how to achieve ideal imaging of both types of light. Specifically, the endoscope's optical system must consider how to ensure a strong signal intensity for the weaker fluorescent light and a large depth of field for the white light, thereby achieving ideal image quality.

[0056] An embodiment of an endoscope according to the present invention provides a rigid endoscope (also known as a rigid tube endoscope or rigid endoscope) with a high-fluorescence transmittance aperture stop. The aperture stop 100 is made of a material with high white light absorption and high infrared transmittance. Because the stop is located at the aperture stop position within the entire system, its strong absorption of white light limits the diameter of the white light beam, ensuring the depth of field of the white light image. Its high infrared transmittance allows the diameter of the infrared beam to be larger than that of white light, ensuring infrared signal strength. This significantly improves fluorescence sensitivity during surgery without compromising the depth of field of the white light image of the rigid endoscope. Furthermore, this solution utilizes the inherent absorption properties of the material. Compared to other methods that use reflective coatings to reduce the size of the white light aperture, this solution not only avoids the problem of stray light generated within the system after reflection of white light, which affects contrast, but also offers numerous advantages over solutions that incorporate reflective-coated apertures on the bonded surfaces of a bonded endoscope, including simpler processing, greater stability, and lower cost.

[0057] In one embodiment, a rigid tube endoscope includes a tube unit and an optical imaging system. The tube unit is inserted into the area to be observed and provides corresponding space for the optical imaging system. Referring to Figure 1 , the optical imaging system may include an objective lens unit 210, an image transfer unit 220, and an eyepiece unit 230. The objective lens unit 210, the image transfer unit 220, and the eyepiece unit 230 may utilize existing architectures and will not be described in detail here. However, the aperture stop 100 in the optical imaging system of the present invention employs a unique structure.

[0058] Referring to Figure 2 , the aperture 100 of the optical imaging system has a through hole in its radially central portion, forming a first light-transmitting region 110. Aperture 100 also has a second light-transmitting region 120 radially outward of first light-transmitting region 110. Second light-transmitting region 120 is configured to absorb light within a first wavelength range and allow light within a second wavelength range to pass through. The light within the first wavelength range is light reflected from the endoscope's light source upon irradiating the site to be observed, while the light within the second wavelength range is fluorescence generated by the endoscope's light source upon irradiating a fluorescent dye within the site to be observed. Those skilled in the art will understand that the aforementioned radial direction refers to a direction perpendicular to the optical axis of the aperture, and the radially central portion is a region of a certain radial dimension centered on the optical axis of the aperture. This region is relative to the outer second light-transmitting region 120 and can be larger or smaller.

[0059] Additionally, it should be noted that, for optical imaging systems, an optical element that absorbs light primarily means absorbing specific light rays, with the goal of preventing them from passing through, for example, with an absorption rate greater than 50%. Similarly, an optical element that allows light to pass generally means primarily transmitting specific light rays, with the goal of allowing them to pass through, for example, with a transmittance greater than 50%. Specifically, for the second light-transmitting region 120 of the aperture stop 100, "absorption" in the present invention may mean an absorption rate of no less than 90% for the specific light rays, while "transmitting" may mean a transmittance of no less than 90% for the specific light rays, thereby better meeting optical performance requirements. Preferably, the light in the first wavelength range is visible light reflected by the endoscope's light source after irradiating the area to be observed, and the visible light transmittance of the second light-transmitting region 120 is no greater than 1%. The light in the second wavelength range is near-infrared light generated by the endoscope's light source irradiating a fluorescent dye on the area to be observed, and the near-infrared light transmittance of the second light-transmitting region 120 is no less than 50%. Of course, in other embodiments, the aforementioned absorbance and transmittance can be higher or lower. However, "absorption" refers primarily to the absorption of specific light, while "transmission" refers primarily to the transmission of specific light. This can still improve optical performance to a certain extent, namely, increasing fluorescence signal intensity and reducing the impact on white light depth of field. Of course, since different fluorescent dyes may produce fluorescence of different wavelengths, the corresponding light transmission area of ​​the aperture should meet the "transmission" characteristics of the corresponding wavelength of fluorescence. For example, infrared light includes near-infrared and far-infrared, and for endoscopes, near-infrared is generally selected as the fluorescence source. In one specific embodiment, the light transmittance curve of the aperture can be referenced in Figure 4.

[0060] In some embodiments, the aperture using the above-described structure can theoretically be set at a non-aperture stop position. However, setting it at the aperture stop position and / or the aperture stop object-image conjugate position in the optical imaging system ensures the best results. Of course, considering cost considerations, it is generally possible to set it only at the aperture stop position, setting it as aperture stop 100, or only at the aperture stop object-image conjugate position. Those skilled in the art will understand that the aperture stop object-image conjugate position refers to other imaging positions in the optical system where the aperture stop passes through internal optical elements.

[0061] In one embodiment, for a rigid tube endoscope, referring to FIG1 , the endoscope includes multiple rod lens assemblies 221 for image rotation. The rod lens assemblies 221 include two pairs of rod lenses 222, with the aperture stop 100 positioned between the two rod lenses 222. Since rigid tube endoscopes often place the aperture stop 100 between the two rod lenses 222, this approach employed in the present invention facilitates optical path design and eliminates the need for significant adjustments to existing optical structures. Specifically, in one embodiment, referring to FIG2 , the end surfaces of the two paired rod lenses 222, which are closer to each other, are convex spherical surfaces 223, at least a portion of which is embedded within the central through-hole of the aperture stop 100. This structure facilitates alignment of the aperture stop 100 and the rod lenses 222. Of course, in other embodiments, the end surfaces of the rod lenses 222, which are closer to each other, may not be convex spherical surfaces 223. In this case, the aperture stop 100 can be radially positioned using other structures, such as a tubular unit. In addition, in another embodiment, there may be a gap between the aperture stop 100 and the rod mirror 222, which does not affect the function of the aperture stop 100 in the present invention.

[0062] It should be noted that in other embodiments, the aperture stop 100 of a rigid endoscope can also be located outside the rod lens assembly 221. Furthermore, endoscopes can generally be categorized as rigid endoscopes, flexible endoscopes (also called hose endoscopes), and electronic endoscopes (also called electronic endoscopes). In some other embodiments, the high-fluorescence transmittance stop of the present invention can also be located on the objective lens of a flexible endoscope or electronic endoscope. Unlike rigid endoscopes, the internal structure of an electronic endoscope can be a circuit system, with a micro-camera chip in the eyepiece and signal wiring inside the tube. Image signals are collected by the eyepiece camera chip, and the signals are transmitted via the wiring inside the tube. The entire electronic endoscope transmits electrical signals, not light. Flexible fiber optic endoscopes also use an objective lens for imaging, but they generally transmit light through optical fibers, which are generally less expensive and have limited resolution.

[0063] In a specific embodiment, the first light-transmitting region 110 is formed by a through hole, and the transmittance of white light and fluorescent light can be considered to be 100%, while the second light-transmitting region 120 is made of a homogeneous material. For example, the material of the second light-transmitting region 120 can be one of acrylonitrile-butadiene-styrene copolymer, polymethyl methacrylate, polyethylene terephthalate plastic, polyetherimide, and polycarbonate. In addition to the above-mentioned plastic materials, the second light-transmitting region 120 can also be made of glass. It should be noted that a homogeneous material is not limited to a single component. For example, a homogeneous material with uniform dopants can also be formed by uniformly incorporating other substances other than the base material.

[0064] In one embodiment, the physical thickness d of the aperture stop 100 is configured to be d>0.3 mm, which is beneficial to ensuring the absorption effect of white light, preventing light leakage, and ensuring its own structural strength.

[0065] To achieve superior optical performance, in one embodiment, the outer diameter of the second light-transmitting region 120 is at least 1.2 times the outer diameter of the first light-transmitting region 110. For example, for the aforementioned high-fluorescence transmittance aperture, the equivalent aperture size for white light can be 4.9 mm, and the equivalent aperture size for fluorescence can be 6.1 mm. Of course, the outer diameter of each light-transmitting region can be set based on the imaging requirements of the optical system. Having the outer diameter of the second light-transmitting region 120 be at least 1.2 times the outer diameter of the first light-transmitting region 110 facilitates excellent image quality near the diffraction limit for both white light and fluorescence.

[0066] Reusable rigid endoscopes require sterilization after use, for example, at temperatures exceeding 100°C. To meet this sterilization requirement, in one embodiment, the aperture has a high-temperature resistance of at least 110°C. Of course, if high-temperature sterilization is not required, this high-temperature resistance may not be a consideration.

[0067] In the above embodiment, a through hole is provided in the radially central portion of the aperture with high fluorescence transmittance, forming the first light-transmitting region 110. However, in some cases, referring to FIG6 , the aperture with high fluorescence transmittance may also be a solid structure. For example, the first light-transmitting region 110 may be made of a material that allows both white light and fluorescence to pass through. Optionally, the material of the first light-transmitting region 110 may also be a homogeneous material, such as one of acrylonitrile-butadiene-styrene copolymer, polymethyl methacrylate, polyethylene terephthalate plastic, polyetherimide, and polycarbonate. The material may also be doped with corresponding substances to achieve corresponding properties. In addition to the aforementioned plastic materials, the first light-transmitting region 110 may also be made of glass. Similar to the second light-transmitting region 120, the first light-transmitting region 110 allows light within the first wavelength range and the second wavelength range to pass through. "Transmitting" means primarily transmitting the specific light. Preferably, "transmitting" means having a transmittance of no less than 90% for the specific light, which can better meet optical performance requirements.

[0068] Of course, in some other embodiments, the first light-transmitting region 110 and / or the second light-transmitting region 120 of the aperture with high fluorescence transmittance may also be made of a non-homogeneous material, such as a multi-layered structure along the axial direction of the aperture, or a material with a radial gradient. Furthermore, the present invention does not exclude the possibility of providing light-transmitting regions other than the first light-transmitting region 110 and the second light-transmitting region 120 on the aperture. For example, in one specific embodiment, the aperture with high fluorescence transmittance may include a third light-transmitting region located between the first light-transmitting region 110 and the second light-transmitting region 120. In some other embodiments, the third light-transmitting region may be located radially outward of the second light-transmitting region 120, and the aperture may further include more light-transmitting regions to achieve corresponding purposes.

[0069] In the above embodiment, the light in the first wavelength range is the light reflected from the endoscope's light source upon irradiation of the area to be observed, and the light in the second wavelength range is the fluorescence generated by the endoscope's light source upon irradiation of a fluorescent dye in the area to be observed. In other embodiments, the aforementioned aperture with high fluorescence transmittance can also be used in other scenarios. As long as the wavelength value of the first wavelength range is smaller than that of the second wavelength range, the light in the first wavelength range can be assigned a smaller aperture size, and the light in the second wavelength range can be assigned a smaller aperture size.

[0070] An embodiment of an aperture diaphragm for an endoscope optical imaging system in the present invention has a structure that is the same as the aperture diaphragm 100 in any of the above-mentioned embodiments of the endoscope, and will not be described in detail here.

[0071] In the present invention, by providing an aperture with high fluorescence transmittance in an endoscope, the aperture's strong absorption of white light can be exploited to limit the diameter of the white light beam, ensuring the depth of field of the white light image. Furthermore, the aperture's high transmittance for infrared light allows the diameter of the infrared beam to be larger than that of white light, thereby ensuring infrared signal strength. Referring to Figure 5 , the left figure shows the fluorescence signal experimental results when the aperture with high fluorescence transmittance in the present invention is used. Compared to the right figure using a traditional aperture, the signal intensity in the left figure is significantly higher, with the aperture 100 as the only variable.

[0072] The above examples are used to illustrate the present invention, which are only used to help understand the present invention and are not intended to limit the present invention. Those skilled in the art can make several simple deductions, modifications or substitutions based on the concept of the present invention.

Claims

1. An endoscope, characterized in that: include: A tubular body unit, wherein the tubular body unit is used to be inserted into a part to be observed; and an optical imaging system, the optical imaging system being arranged in the tube unit, the optical imaging system comprising an aperture; A through hole is provided in the radial middle portion of the aperture, and the through hole forms a first light-transmitting area; the aperture also has a second light-transmitting area located radially outside the first light-transmitting area, and the second light-transmitting area is used to absorb light in the first wavelength range and allow light in the second wavelength range to pass through; the light in the first wavelength range is light reflected after the light source of the endoscope irradiates the part to be observed, and the light in the second wavelength range is the fluorescence generated by the fluorescent dye irradiating the part to be observed by the light source of the endoscope.

2. The endoscope according to claim 1, wherein: The diaphragm is arranged at an aperture diaphragm position and / or an aperture diaphragm object-image conjugate position of the optical imaging system.

3. The endoscope according to claim 2, characterized in that The endoscope is a rigid tube endoscope, and comprises a rod mirror assembly for image rotation, wherein the rod mirror assembly comprises two rod mirrors in a pair, and the aperture is arranged between the two rod mirrors in a pair.

4. The endoscope according to claim 3, wherein: At least a portion of the end surfaces of the two paired rod mirrors close to each other at one end is a convex spherical surface, and at least a portion of the convex spherical surface is embedded in the through hole in the middle of the aperture.

5. The endoscope according to claim 1, wherein: The endoscope is a hose endoscope or an electronic endoscope, and the aperture is located on the objective lens of the hose endoscope or the electronic endoscope.

6. An endoscope, characterized in that: include: A tubular body unit, wherein the tubular body unit is used to be inserted into a part to be observed; and an optical imaging system, the optical imaging system being arranged in the tube unit, the optical imaging system comprising an aperture; The aperture has a first light-transmitting area located in the radial middle part thereof and a second light-transmitting area located radially outside the first light-transmitting area; the first light-transmitting area allows light located in the first wavelength range and the second wavelength range to pass through, and the second light-transmitting area is used to absorb light located in the first wavelength range and allow light located in the second wavelength range to pass through; the light in the first wavelength range is light reflected after the light source of the endoscope irradiates the part to be observed, and the light in the second wavelength range is fluorescence generated by the fluorescent dye irradiated by the light source of the endoscope onto the part to be observed.

7. An endoscope, characterized in that: include: A tubular body unit, wherein the tubular body unit is used to be inserted into a part to be observed; and an optical imaging system, the optical imaging system being arranged in the tube unit, the optical imaging system comprising an aperture; A through hole is provided in the radial middle portion of the aperture, and the through hole forms a first light-transmitting area; the aperture also has a second light-transmitting area located radially outside the first light-transmitting area, and the second light-transmitting area is used to absorb light in the first wavelength range and allow light in the second wavelength range to pass through; the wavelength value of the first wavelength range is smaller than the wavelength value of the second wavelength range.

8. The endoscope according to any one of claims 1 to 7, characterized in that The physical thickness d of the aperture is configured such that d>0.3 mm.

9. The endoscope according to any one of claims 1 to 7, characterized in that The light in the first wavelength range is visible light, and the visible light transmittance of the second light-transmitting area is no more than 1%.

10. The endoscope according to any one of claims 1 to 7, characterized in that: The light in the second wavelength range is near-infrared light, and the near-infrared light transmittance of the second light-transmitting area is not less than 50%.

11. The endoscope according to any one of claims 1 to 7, characterized in that: The outer diameter of the second light-transmitting area is greater than 1.2 times the outer diameter of the first light-transmitting area.

12. The endoscope according to any one of claims 1 to 7, characterized in that: The first light-transmitting area is made of a homogeneous material, and / or the second light-transmitting area is made of a homogeneous material.

13. The endoscope according to claim 12, wherein: The material of the first light-transmitting area is one of acrylonitrile-butadiene-styrene copolymer, polymethyl methacrylate, polyethylene terephthalate plastic, polyetherimide and polycarbonate; And / or, the material of the second light-transmitting area is one of acrylonitrile-butadiene-styrene copolymer, polymethyl methacrylate, polyethylene terephthalate plastic, polyetherimide and polycarbonate.

14. The endoscope according to any one of claims 1 to 7, characterized in that: The high temperature resistance of the aperture is not less than 110 degrees Celsius.

15. The endoscope according to any one of claims 1 to 7, characterized in that: The aperture has a third light-transmitting area, and the third light-transmitting area is located between the first light-transmitting area and the second light-transmitting area and / or radially outside the second light-transmitting area.

16. A diaphragm for an endoscope optical imaging system, characterized in that: include: A first light-transmitting area, wherein the first light-transmitting area is located in the radial middle of the aperture; and a second light-transmitting area, the second light-transmitting area being located radially outward of the first light-transmitting area; The first light-transmitting area allows light in the first wavelength range and the second wavelength range to pass through, and the second light-transmitting area is used to absorb light in the first wavelength range and allow light in the second wavelength range to pass through; the light in the first wavelength range is light reflected after the light source of the endoscope illuminates the part to be observed, and the light in the second wavelength range is fluorescence generated by the fluorescent dye of the part to be observed illuminated by the light source of the endoscope, and the wavelength value of the first wavelength range is smaller than the wavelength value of the second wavelength range.

17. The diaphragm according to claim 16, characterized in that A through hole is provided in the radial middle portion of the aperture, and the first light-transmitting area is formed by the through hole.

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