An infrared optical industrial endoscope system and apparatus

Abstract

The application discloses an infrared optical industrial endoscope system and equipment, which comprises a diaphragm hole, a front end imaging lens group, a first turning mirror, a relay lens group, a second turning mirror, a rear end imaging lens group and an infrared camera, wherein the diaphragm hole is used for receiving thermal radiation light of a magnetic confinement nuclear fusion EAST Tokamak device and making the light pass through the diaphragm hole and then enter the front end imaging lens group, the light is reflected to the relay lens group through the first turning mirror after forming a first image plane through the front end imaging lens group, and then the light is relayed and imaged to a second image plane through the second turning mirror, and then the light is imaged to a target plane of the infrared camera through the rear end imaging lens group; in the use process, the application can make the structure of the whole system more flexible, and can better adapt to the complex structure layout inside the EAST Tokamak device.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of industrial endoscopes, and in particular to an infrared optical industrial endoscope system and equipment. Background Art

[0002] An industrial endoscope is a tool that can non-destructively detect the internal structure and status of sealed cavities. It is commonly used in high-temperature, toxic, nuclear radiation, and strong magnetic field environments, enabling remote observation and operation. It is widely used in various industrial applications. Commonly used industrial endoscopes utilize different principles depending on their purpose and the specific properties of the material. For example, ultrasonic testing (UT) utilizes sound, magnetic particle testing (MT) utilizes magnetic properties, and radiographic testing (RT) utilizes radiation properties.

[0003] In the field of magnetic confinement fusion (EAST), controlled nuclear fusion energy holds the greatest promise as the next generation of clean energy, so isostadic long-pulse plasma discharge is one of EAST's primary goals. However, in a magnetic confinement fusion tokamak, the energy in the plasma, whether generated through ohmic heating, auxiliary wave heating, or fusion reactions, undergoes a series of transport processes such as radiation, heat conduction, and convection, ultimately depositing on the first wall surface. Long-term plasma-wall interaction causes the surface temperature of the first wall material to rise sharply, leading to corrosion, melting, and evaporation of the material. This not only contaminates the plasma and destroys its confinement properties, but also shortens the device's operating life and even endangers its safety. Therefore, to achieve steady-state operation of the tokamak, it is necessary to diagnose instabilities generated during plasma discharge. Measuring the first wall temperature is a key indicator of plasma pulse stability, and endoscopes therefore employ a number of improved diagnostic techniques, such as electron cyclotron radiation imaging and infrared optical imaging.

[0004] Infrared optical imaging technology utilizes the plasma's ability to generate medium-wave infrared and visible light, employing infrared thermal imaging technology to monitor the first wall temperature and diagnose the first wall's thermal field distribution. Infrared imaging technology is mostly applicable to high-temperature environments. It utilizes an infrared detector and an optical imaging objective lens to receive the infrared radiation energy distribution pattern of the target being measured and reflect it onto the infrared detector's photosensitive element, thereby obtaining an infrared thermal image. This thermal image corresponds to the thermal distribution field on the object's surface. Currently, infrared optical systems utilize a coaxial catadioptric optical structure to achieve medium-wave or long-wave infrared imaging. However, due to its coaxial lens structure, it cannot be bent, and thus cannot adopt a variety of structural forms, making it difficult to adapt to the complex internal structural layout of the EAST tokamak device.

[0005] In view of this, how to provide an infrared optical industrial endoscope system and equipment that solves the above technical problems has become a problem that needs to be solved by those skilled in the art. Summary of the Invention

[0006] The purpose of the embodiments of the present invention is to provide an infrared optical industrial endoscope system and equipment, which makes the structural setting of the entire system more flexible during use and can better adapt to the complex structural layout inside the EAST tokamak device.

[0007] To solve the above technical problems, an embodiment of the present invention provides an infrared optical industrial endoscope system, comprising:

[0008] Aperture, front imaging lens group, first folding reflector, relay lens group, second folding reflector, rear imaging lens group and infrared camera, wherein:

[0009] The aperture hole is used to receive the thermal radiation light of the magnetic confinement nuclear fusion EAST tokamak device, and make the light pass through the aperture hole and then enter the front imaging lens group. After the first image plane is formed by the front imaging lens group, the light is then reflected by the first folding reflector to the relay lens group and reflected by the second folding reflector to be relayed and imaged to the second image plane. The light is then imaged by the rear imaging lens group to the target surface of the infrared camera.

[0010] Optionally, the relative aperture of the aperture is 1 / 4.

[0011] Optionally, the infrared camera is arranged on the outside of the EAST tokamak device.

[0012] Optionally, it also includes a sealed shell made of stainless steel material and arranged on the periphery of the aperture, the front imaging lens group, the first folding reflector, the relay lens group, the second folding reflector and the rear imaging lens group for sealing each optical device.

[0013] Optionally, the front-end imaging mirror group, the first folding reflector, the relay mirror group, the second folding reflector and the rear-end imaging mirror group are all optical devices made of materials that are resistant to silicide lithiated contamination.

[0014] Optionally, the front-end imaging mirror group, the first folding reflector, the relay mirror group, the second folding reflector and the rear-end imaging mirror group are all provided with an anti-radiation protective film.

[0015] Optionally, the front-end imaging lens group is a plano-convex lens.

[0016] Optionally, the relay lens assembly includes a convex lens and a concave lens.

[0017] Optionally, the first folding reflector and the second folding reflector are both plane reflectors.

[0018] The application further provides an infrared optical industrial endoscope device, comprising the infrared optical industrial endoscope system as described above.

[0019] The application provides an infrared optical industrial endoscope system and device, comprising: an aperture, a front-end imaging lens group, a first turning mirror, a relay lens group, a second turning mirror, a rear-end imaging lens group and an infrared camera, wherein: the aperture is used for receiving thermal radiation light of a magnetic confinement nuclear fusion EAST Tokamak device, and the light is shot into the front-end imaging lens group after passing through the aperture, and after forming a first image plane by the front-end imaging lens group, the light is reflected to the relay lens group by the first turning mirror and relayed to a second image plane after being reflected by the second turning mirror, and then the light is imaged to a target plane of the infrared camera by the rear-end imaging lens group.

[0020] It can be seen that in the application, the thermal radiation light of the EAST Tokamak device can be shot into the front-end imaging lens group through the aperture, and a first image plane is formed by the front-end imaging lens group, and after forming the first image plane, the light continues to propagate to the first turning mirror, and is incident to the relay lens group after being reflected by the first turning mirror, and is incident to the second turning mirror by the relay lens group, and then the light is relayed to the second image plane, and after being imaged to the second image plane, the light continues to propagate to the rear-end imaging lens group and is imaged to the target plane of the infrared camera to form an infrared image. Since the first turning mirror and the second turning mirror in the application can change the propagation direction of the light, the structure of the whole system can be more flexible, and the complex structure layout inside the EAST Tokamak device can be better adapted. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the prior art and the embodiments. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort based on these drawings.

[0022] Figure 1 A structural schematic diagram of an infrared optical industrial endoscope system provided by the application;

[0023] Figure 2 An MTF modulation transfer function diagram provided by the application;

[0024] Figure 3 A point column diagram provided by the application;

[0025] Figure 4 An energy concentration degree curve diagram provided by the application;

[0026] Figure 5 A schematic diagram of distortion provided by an embodiment of the present invention;

[0027] Figure 6 A schematic diagram of a relative illumination curve provided by an embodiment of the present invention;

[0028] Figure 7 This is a schematic diagram of MTF at an object distance of 1000+100mm provided by an embodiment of the present invention;

[0029] Figure 8 This is a spot diagram provided by an embodiment of the present invention at an object distance of 1000-100 mm. DETAILED DESCRIPTION

[0030] The embodiment of the present invention provides an infrared optical industrial endoscope system and equipment, which makes the structural setting of the entire system more flexible during use and can better adapt to the complex structural layout inside the EAST tokamak device.

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0032] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of an infrared optical industrial endoscope system provided by an embodiment of the present invention. The infrared optical industrial endoscope system includes:

[0033] Aperture 1, front imaging lens group 2, first folding reflector 3, relay lens group 4, second folding reflector 5, rear imaging lens group 6 and infrared camera 7, wherein:

[0034] The aperture hole 1 is used to receive the thermal radiation light of the magnetic confinement nuclear fusion EAST tokamak device, and make the light pass through the aperture hole 1 and enter the front imaging lens group 2. After the front imaging lens group 2 forms the first image plane A, the light is reflected by the first folding reflector 3 to the relay lens group 4 and reflected by the second folding reflector 5 to be relayed to the second image plane B. The light is then imaged by the rear imaging lens group 6 to the target surface of the infrared camera 7.

[0035] Specifically, in this embodiment, a pinhole imaging optical path can be used. Specifically, an aperture hole 1 can be set to receive the thermal radiation light of the EAST tokamak device, that is, a small aperture is used as the light-transmitting aperture of the system, wherein the aperture hole 1 can adopt a larger relative aperture (for example, 1 / 4), so as to ensure the light flux while blocking external particles and rays from entering the endoscope system as much as possible. In addition, the thermal radiation light will be incident on the front imaging lens group 2 after passing through the aperture hole 1, and form a first image plane A after passing through the front imaging lens group 2. After forming the first image plane A, the light continues to propagate to the first folding reflector 3. Since the first folding reflector 3 can be set with a corresponding inclination angle, the direction of the light path is changed, so that the reflected light is incident on the relay lens group 4. That is, the relay lens group 4 can be on a different optical axis from the front imaging lens group. The relay lens group 4 can image the first image plane to the second image plane, thereby extending the light path. Specifically, in this embodiment, In the application, a second folding reflector 5 is provided after the relay mirror group 4. Therefore, after the light is incident on the relay mirror group 4, the transmitted light is incident on the second folding reflector 5, so that the second image plane B is formed by the reflected light. That is, the second image plane B is not on the same straight line as the relay mirror group 4. The light forming the second image plane B continues to propagate to the rear imaging mirror group 6, and then is imaged onto the target surface of the infrared camera 7 through the rear imaging mirror group 6. A flange 8 is provided after the relay mirror group 4, and the endoscope system can be connected to the tokamak device through the flange 8. That is, in the present application, the structure of the entire endoscope system can be further adjusted by setting the angles of the first folding reflector 3 and the second folding reflector 5, so that the structure of the entire endoscope system can adapt to the complex internal space of the EAST tokamak device. The specific angles of the first folding reflector 3 and the second folding reflector 5 can be set according to the actual situation inside the EAST tokamak device, and are not specifically limited in the present application.

[0036] Among them, in order to effectively prevent external radiation from entering the interior of the endoscope system, the endoscope system is sealed. That is, the various optical components in the endoscope system can be sealed using a sealed housing, so that the optical components after the aperture 1 are in a vacuum environment, and only thermal radiation light is allowed to enter the system through the aperture 1, preventing thermal radiation light and other particles from entering the system from the side and causing contamination. In addition, because the application adopts a method of multiple imaging to collect infrared images, the optical path can be extended, and the number of optical components operating in a high-temperature, high-radiation environment can be minimized. Because the cost of the infrared camera 7 is relatively high, the infrared camera 7 can be placed outside the EAST tokamak device by extending the optical path, thereby extending the service life of the infrared camera 7.

[0037] Specifically, this embodiment may further include a sealed housing made of stainless steel, disposed around the periphery of the aperture 1, front imaging lens assembly 2, first folding reflector 3, relay lens assembly 4, second folding reflector 5, and rear imaging lens assembly 6, for sealing the various optical components. That is, the sealed housing in this embodiment only needs to seal the optical path formed by the aperture 1, front imaging lens assembly 2, first folding reflector 3, relay lens assembly 4, second folding reflector 5, and rear imaging lens assembly 6. To ensure a sufficient sealing effect, the sealed housing may be made of 316L stainless steel.

[0038] Furthermore, the relative aperture of the aperture 1 in this embodiment is 1 / 4, and the field of view of the endoscope system can be 24°, thereby better protecting the optical system from contamination and damage while ensuring light flux. Furthermore, in order to improve the system's ability to resist high-temperature plasma contamination and extend the life of each optical component, the front-end imaging lens group 2, first folding reflector 3, relay lens group 4, second folding reflector 5, and rear-end imaging lens group 6 in this embodiment are all optical components made of materials that are resistant to lithium silicide contamination, specifically optical components made of infrared band materials that are resistant to lithium silicide contamination.

[0039] Furthermore, the front-end imaging lens group 2, the first folding reflector 3, the relay lens group 4, the second folding reflector 5 and the rear-end imaging lens group 6 in this embodiment are all provided with an anti-radiation protective film to further improve the system's ability to resist high-temperature plasma contamination and extend the life of each optical component.

[0040] Specifically, the front-end imaging lens group 2 in this embodiment can be a plano-convex lens, and a single lens made of silicon material can be used to achieve ±12° object field imaging, so that the light incident on the front-end imaging lens group 2 forms a first image plane.

[0041] In addition, the rear-end imaging lens group 6 in this embodiment can be composed of four single lenses, and the four single lenses can be single lenses made of silicon, germanium, silicon, and silicon respectively. Spherical aberration and off-axis aberration can be corrected by setting the curvature and spacing of each lens, chromatic aberration can be corrected by the dispersion characteristics of different materials, and field curvature can be corrected by a meniscus lens in front of the image plane, where the meniscus lens refers to the last of the four single lenses, that is, the single lens close to the image plane.

[0042] It should be noted that the relay lens group 4 in this embodiment includes a convex lens and a concave lens, and the convex lens can be a convex lens made of silicon, and the concave lens can be a concave lens made of germanium. In practical applications, the correction of spherical aberration and chromatic aberration can be achieved by setting the combination of the optical power of the convex lens and the concave lens, the curvature of the lens and the dispersion characteristics of the material.

[0043] Specifically, the first folding reflector 3 and the second folding reflector 5 in this embodiment are both plane reflectors, which realize the folding of the light path, making the system structure more flexible, thereby meeting the complex internal structure of the EAST tokamak device and further suppressing radiation.

[0044] In addition, the infrared camera 7 in the present application uses a focal plane array detector at the cold end to receive the image, and the image quality remains basically unchanged within the object distance of 4000mm, and the full field of view distortion is small.

[0045] It should also be noted that the image plane of the sub-optical system formed by the various optical components in the endoscope system in this embodiment coincides with the target plane of the infrared camera 7 , thereby achieving image acquisition.

[0046] Furthermore, to achieve matching of the cold stop in the imaging system, the optical system's F-number must be designed to match that of the infrared camera, and the pupil position must be aligned with the camera's cold stop. The F-number of an optical system is the ratio of focal length to aperture. Specifically, the relative aperture of the imaging system in this application is determined by the F-number of the infrared camera 7, which is the inverse of the aperture. For a cooled infrared camera, the F-number is the ratio of the distance between the cold stops and the target surface to the cold stop aperture. For example, the camera cold stop aperture can be 5 mm, with the cold stop distance 20 mm from the camera target surface. The imaging wavelength range of the system in this application can be 3 to 4.9 μm, which can be determined by the waveguide of the infrared camera 7. In practical applications, a Telops MSM100k with 640×512 pixels, a pixel size of 16 μm, a target size of 10.24×8.192 mm, a diagonal of 13.11 mm, and an F / 4 infrared camera can be selected. For example, if the field of view FOV is 17° and the camera diagonal size is 13.11 mm, then the system focal length f satisfies:

[0047] f×tan(24° / 2)=13.11 / 2, then f=30.85mm, and taking the focal length f=30mm, the aperture is 30 / 4=7.5mm, the total optical length is greater than 845mm, and the designed object distance can be 4000mm.

[0048] In addition, through the imaging quality analysis of the infrared optical industrial endoscope system provided in this application, it can be seen that the infrared optical industrial endoscope system provided in this application can improve the imaging quality. Figures 2 to 6 , among which, Figure 2 It can be seen that the system has an MTF>0.65 at the camera's Nyquist frequency (17lp / mm). Figure 2 The horizontal axis sprtirlfrequency in cycles per mm represents the frequency (unit: cycle / mm), and the vertical axis represents the MTF modulation transfer function;Figure 3 It can be seen that the RMS diameter of the spot diagram is less than 12 μm, reaching the diffraction limit; Figure 4 It can be seen that 80% of the energy concentration is less than 2×2 pixels (32μm); Figure 5 It can be seen that the full field of view distortion is less than 1%; Figure 6 It can be seen that the relative illumination of the system: the edge field of view reaches 70% of the central field of view. By analyzing the indicators of the infrared optical industrial endoscope system provided in this application, it can be seen that in the resolution analysis, according to the system object distance 4m, focal length 30mm, pixel size 16μm, the object-side pixel resolution b is calculated as: b / 4000=0.016 / 30, and b=2.13mm is obtained, that is, the system object-side pixel resolution is about 2.13mm; in the depth of field analysis, since the system requires the depth of field to reach ±20mm, the depth of field is analyzed according to ±100mm. For details, please refer to Figure 7 and Figure 8 , it can be seen that the system's depth of field is greater than ±100mm, which meets the index requirements.

[0049] It can be seen that in the present application, the thermal radiation light of the EAST tokamak device can pass through the aperture hole to enter the front imaging mirror group, and form a first image plane through the front imaging mirror group. After forming the first image plane, the light continues to propagate to the first folding reflector, and after being reflected by the first folding reflector, it is incident on the relay mirror group and incident on the second folding reflector through the relay mirror group. Then the light is relayed and imaged to the second image plane. After being imaged to the second image plane, the light continues to propagate to the rear imaging mirror group and is imaged on the target surface of the infrared camera to form an infrared image. Since the setting of the first folding reflector and the second folding reflector in the present application can change the propagation direction of the light, the structural setting of the entire system can be made more flexible, and can better adapt to the complex structural layout inside the EAST tokamak device.

[0050] On the basis of the above embodiment, an embodiment of the present invention further provides an infrared optical industrial endoscope device, which includes the infrared optical industrial endoscope system as described above.

[0051] It should be noted that the infrared optical industrial endoscope equipment provided in this embodiment has the same beneficial effects as the infrared optical industrial endoscope system provided in the above embodiments, and for the specific introduction of the infrared optical industrial endoscope system involved in this embodiment, please refer to the above embodiments, and this application will not go into details here.

[0052] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0053] It should also be noted that, in this specification, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0054] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An infrared optical industrial endoscope system, characterized in that: include: Aperture, front imaging lens group, first folding reflector, relay lens group, second folding reflector, rear imaging lens group and infrared camera, wherein: The aperture is used to receive thermal radiation light from the magnetic confinement nuclear fusion EAST tokamak device, and allows the light to pass through the aperture and then enter the front imaging mirror group. After the front imaging mirror group forms a first image plane, the light is then reflected by the first folding reflector to the relay mirror group and reflected by the second folding reflector to be relayed and imaged to the second image plane. The light is then imaged by the rear imaging mirror group to the target surface of the infrared camera; wherein, the relay mirror group and the front imaging mirror group do not share a common optical axis, and the second image plane and the relay mirror group are not on the same straight line; The relative aperture of the aperture is 1 / 4; the field of view of the endoscope system is 24°; The infrared camera is arranged on the outside of the EAST tokamak device; It also includes a sealed housing made of stainless steel material and disposed on the periphery of the aperture, the front imaging lens group, the first folding reflector, the relay lens group, the second folding reflector, and the rear imaging lens group for sealing each optical component; The front-end imaging mirror group, the first folding reflector, the relay mirror group, the second folding reflector and the rear-end imaging mirror group are all optical devices made of materials that are resistant to silicide lithiated contamination; The front imaging mirror group, the first folding reflector, the relay mirror group, the second folding reflector and the rear imaging mirror group are all provided with a radiation protection film; The front-end imaging lens group is a plano-convex lens; The relay lens assembly includes a convex lens and a concave lens.

2. The infrared optical industrial endoscope system according to claim 1, characterized in that: The first folding reflective mirror and the second folding reflective mirror are both plane reflective mirrors.

3. An infrared optical industrial endoscope device, characterized in that: The invention comprises the infrared optical industrial endoscope system as claimed in claim 1 or 2.

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