High-sensitivity solar blind and visible light dual-band wide-angle imaging system

Abstract

The invention discloses a high-sensitivity solar blind and visible light dual-band wide-angle imaging system, the system comprises an ultraviolet optical imaging system, a visible light imaging system, a control unit and an image processing unit, the ultraviolet optical imaging system comprises an ultraviolet optical lens unit and an ICMOS coupling structure unit, and the visible light imaging system comprises a visible light camera. The ultraviolet optical lens unit comprises a lens barrel, a lens assembly and an optical filter, the working wave band of the ultraviolet optical lens unit is 250nm-270nm, the central wavelength is 260nm, and the field angle is greater than 100 degrees; the ICMOS coupling structure unit is connected with the ultraviolet optical lens unit and comprises an intensifier, a light cone and a detector which are coupled, the cathode response wave band of the ICMOS coupling structure unit is 200 nm to 310 nm, the cathode diameter is 18 mm, and the cathode detection sensitivity is smaller than 3.0 * 10 <-15 > watt / cm < 2 >. By means of the system, the problem that in the prior art, the detection performance is poor is solved, and fusion imaging detection of a weak solar blind radiation target can be achieved.

Description

Technical Field

[0001] The present invention relates to the field of optical technologies, and particularly to a highly sensitive solar-blind and visible light dual-band wide-angle imaging system. Background Art

[0002] Currently, in order to ensure the normal operation of a visible light camera inside a sealed box, LED lighting is usually arranged inside the sealed box. The illuminance reaching the target surface of a solar-blind ultraviolet detector is relatively low, belonging to extremely weak radiation detection.

[0003] Traditionally, for weak solar-blind ultraviolet signals, a photomultiplier tube is usually used for signal detection. The photomultiplier tube has high sensitivity, but it cannot image, nor can it detect the radiation spatial distribution. Moreover, due to its high sensitivity, it is extremely sensitive to noise. The stray light inside the sealed box will reduce its signal-to-noise ratio and may also cause it to saturate or even damage the device. Additionally, for existing off-the-shelf solar-blind ultraviolet camera products, although they can perform dual-band detection of solar-blind ultraviolet and visible light and can also locate solar-blind ultraviolet signals, their field of view is relatively small, unable to meet the detection requirement of a 110° field of view. The detected target intensity is relatively strong, and generally, ordinary lenses and ordinary ultraviolet area array detectors are used, and their out-of-band suppression ability, anti-stray light ability, and detection sensitivity cannot meet the radiation distribution detection requirement inside the sealed box.

[0004] Therefore, the existing solar-blind and visible light dual-band wide-angle imaging technologies have problems of poor detection performance. Summary of the Invention

[0005] The purpose of the present invention is to provide a highly sensitive solar-blind and visible light dual-band wide-angle imaging system to solve the problem of poor detection performance existing in the existing solar-blind and visible light dual-band wide-angle imaging technologies.

[0006] The technical solution provided by the present invention is as follows:

[0007] The present invention provides a highly sensitive solar-blind and visible light dual-band wide-angle imaging system, including:

[0008] An ultraviolet optical imaging system, a visible light imaging system, a control unit, and an image processing unit designed with parallel optical axes. The ultraviolet optical imaging system includes an ultraviolet optical lens unit and an ICMOS coupling structure unit, and the visible light imaging system includes a visible light camera;

[0009] The ultraviolet optical lens unit includes a lens barrel, a lens assembly, and a filter. The lens assembly is arranged on the lens barrel, and at least one filter is located on the optical path formed by the lens assembly, such that the working band of the ultraviolet optical lens unit is 250 nm - 270 nm, the central wavelength is 260 nm, and the field of view is greater than 100°;

[0010] The ICMOS coupling structure unit is connected to the ultraviolet optical lens unit. The ICMOS coupling structure unit includes a coupled intensifier, a light cone, and a detector. The cathode response band of the ICMOS coupling structure unit is 200nm - 310nm, the cathode diameter is 18mm, and the cathode detection sensitivity is less than 3.0×10 -15 watt / cm 2 ;

[0011] Both the visible light camera and the ultraviolet optical lens unit adopt ICMOS coupling design. Both the visible light camera and the ultraviolet optical lens unit have a field of view range exceeding 2m×3m at an observation distance of 1.2m;

[0012] The control unit is used to control the ultraviolet optical imaging system and the visible light imaging system;

[0013] The image processing unit is used to collect and process images of the ultraviolet optical imaging system and the visible light imaging system.

[0014] Furthermore, the filter adopts a multilayer film structure, which is formed by a quartz substrate and hafnium dioxide and silicon dioxide deposited on the quartz substrate. The number of filters is two, and the out-of-band cut-off of the two filters is OD14.

[0015] Furthermore, the ultraviolet optical lens unit further includes an adjusting washer assembly, a retaining ring assembly, an exhaust hole, and a glue injection hole. The adjusting washer assembly includes a plurality of adjusting washers, and the retaining ring assembly includes a plurality of retaining rings;

[0016] The lens barrel is in the shape of a trumpet with a large mouth and a small bottom. The lens assembly is arranged in the lens barrel along the optical path. The lens assembly includes multiple groups of lenses. An adjusting washer and a retaining ring are arranged between each group of lenses. An exhaust hole is arranged on the lens barrel between each group of lenses, and a glue injection hole is also arranged on the circumferential side of the lens barrel.

[0017] Furthermore, the intensifier is a solar-blind double MCP image intensifier with a diameter of 18mm. The solar-blind double MCP image intensifier adopts 2 V-type cascades, and the gain multiple is 10 4 -10 6 , the cathode response band of the solar-blind double MCP image intensifier: 200nm - 310nm, the cathode diameter 18mm, the cathode detection sensitivity: <3.0×10-15watt / cm 2 ;

[0018] The reduction ratio of the light cone is 2:1, and the transmittance is greater than 40%.

[0019] The detector is a CMOS detector.

[0020] Further, it also includes a box body, an interface unit, and a power supply component;

[0021] The box body is provided with a first window and a second window in parallel, and the ultraviolet optical imaging system and the visible light imaging system are respectively embedded in the first window and the second window;

[0022] The interface unit includes a first interface and a second interface. The first interface and the second interface are arranged on the box body on the opposite side of the first window and the second window, and the first interface, the second interface are connected to the ultraviolet optical imaging system and the visible light imaging system;

[0023] The power supply component and the control unit are both arranged in the box body, and the power supply component is electrically connected to the control unit, the ultraviolet optical imaging system, and the visible light imaging system respectively.

[0024] Further, the height of the box body is 1.2 m, the length and width of the bottom are 2 m×3 m, and the box body is provided with a handle;

[0025] The light cone is a customized light cone. The design parameters of the customized light cone include the large end diameter, the small end diameter length, the light cone length, the projection length of the horizontal center line of the target after distortion on the CMOS target surface, and the projection length of the vertical center line of the target after distortion on the CMOS target surface. The large end diameter is 18 mm, the small end diameter length is 9 mm, the light cone length is 15 mm, the projection length of the horizontal center line of the target after distortion on the CMOS target surface is 8 mm, and the projection length of the vertical center line of the target after distortion on the CMOS target surface is 6.4 mm.

[0026] Further, the detector is an ICMOS detector, and the ICMOS detector includes a CMOS detector, an ICMOS coupling structure, an ICMOS high-voltage control and telemetry module, a power supply module, and a camera communication control module.

[0027] Further, the image processing unit includes a fluorescent screen for displaying images;

[0028] The control unit is also used for the screen voltage adjustment and telemetry of the fluorescent screen.

[0029] Further, the control unit includes a control module and an electronic control module, the power supply component includes a high-voltage power supply, the high-voltage power supply provides high voltage for the fluorescent screen and the intensifier, the control module is used for command control telemetry, and the electronic control module is used for high-voltage adjustment.

[0030] Further, the voltage range of the high-voltage power supply is 0 - 8000V.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] The high-sensitivity solar-blind and visible light dual-band wide-angle imaging system provided by the present invention adopts wide-angle dual-band imaging with a field of view angle exceeding 100 degrees, meets the imaging requirements inside a sealed box, facilitates subsequent image fusion, and conducts radiation spatial distribution detection and positioning; the system adopts a narrow-band solar-blind ultraviolet optical system design with high transmittance and high out-of-band rejection ratio to improve the signal-to-noise ratio of the system; the system adopts a high-sensitivity lightweight ICMOS design with a double MCP with a diameter of 18 mm and a small-scale reduction optical cone to meet the requirements of weight and extremely weak signal detection; the system adopts an imaging method of short integration + multiple exposure accumulation to improve the image signal-to-noise ratio; the system has a high-precision coupling structure design, and while ensuring the safety of the detection target surface, the coupling distance between the MCP, the optical cone, and the CMOS detector is minimized in the structural design to improve the resolution and energy transmission efficiency. Description of the Drawings

[0033] Figure 1 is the structural framework diagram of the high-sensitivity solar-blind and visible light dual-band wide-angle imaging system in the embodiment of the present invention;

[0034] Figure 2 is the structural schematic diagram of the high-sensitivity solar-blind and visible light dual-band wide-angle imaging system in the embodiment of the present invention Figure 1 ;

[0035] Figure 3 is the structural schematic diagram of the high-sensitivity solar-blind and visible light dual-band wide-angle imaging system in the embodiment of the present invention Figure 2 ;

[0036] Figure 4 is the schematic diagram of the internal device structure of the box of the high-sensitivity solar-blind and visible light dual-band wide-angle imaging system in the embodiment of the present invention;

[0037] Figure 5 is the structural schematic diagram of the ultraviolet optical lens unit in the embodiment of the present invention;

[0038] Figure 6 is the structural schematic diagram of the ICMOS coupling structure unit in the embodiment of the present invention;

[0039] Figure 7 is the schematic diagram of the multilayer film structure of the filter in the embodiment of the present invention;

[0040] Figure 8 is the transmittance curve diagram of the filter in the embodiment of the present invention;

[0041] Figure 9 is the parameter diagram of the optical cone in the embodiment of the present invention;

[0042] Figure 10 This is the angular resolution test image and enlarged image of the high-sensitivity solar-blind and visible light dual-band wide-angle imaging system in the embodiment of the present invention, where a is the angular resolution test image and b is the enlarged image.

[0043] The reference numerals are as follows:

[0044] 100 - box body, 101 - first window, 102 - second window, 200 - ultraviolet optical imaging system, 201 - ultraviolet optical lens unit, 2011 - lens barrel, 2012 - lens assembly, 2013 - adjusting washer assembly, 2014 - retaining ring assembly, 2015 - exhaust hole, 2016 - glue injection hole, 202 - ICMOS coupling structure unit, 2021 - intensifier, 2022 - light cone, 2023 - detector, 300 - visible light imaging system, 301 - visible light camera, 400 - handle, 500 - control unit, 600 - interface unit, 601 - first interface, 602 - second interface, 700 - image processing unit, 800 - power supply assembly, 900 - target radiation. Detailed implementation manners

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the embodiments described below are some, rather than all, of the embodiments of the present application. Usually, the components of the embodiments of the present application described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0046] Therefore, the detailed description of the embodiments of the present application provided below with reference to the accompanying drawings is only intended to represent the selected embodiments of the present application, and does not limit the scope of the present application claimed. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts belong to the scope of protection of the present application.

[0047] It should be understood that in the description of the embodiments of the present invention, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of the described features.

[0048] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "arrangement", "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a connection that allows mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0049] Referring to Figure 1 , the present invention provides a highly sensitive solar-blind and visible light dual-band wide-angle imaging system. The system includes an ultraviolet optical imaging system 200, a visible light imaging system 300, a control unit 500, and an image processing unit 700 designed with parallel optical axes. The ultraviolet optical imaging system 200 includes an ultraviolet optical lens unit 201 and an ICMOS coupling structure unit 202, and the visible light imaging system 300 includes a visible light camera 301.

[0050] The ultraviolet optical lens unit 201 includes a lens barrel 2011, a lens assembly 2012, and a filter (not shown in the figure). The lens assembly 2012 is arranged on the lens barrel, and at least one filter is located in the optical path formed by the lens assembly 2012 or on the target surface of the detector. Through the above design, the working band of the ultraviolet optical lens unit 201 is 250 nm - 270 nm, the central wavelength is 260 nm, and the field of view angle is greater than 100°.

[0051] The above system provided by the present invention is applicable to a target radiation intensity of 1×10 8 photons / s@3 cm×3 cm@260 nm ± 10 nm. Field of view range: at an observation distance of 1.2 m, >2 m×3 m. Since there is a small amount of solar-blind band radiation in the target radiation of the atmospheric background 900, a deep cut-off rate filter is also required to filter the background. According to research, when the cut-off depth of the filter is better than OD6, it can respond well to this target radiation intensity. In addition, if the field of view of the lens is better than 103°, it can meet the requirement of a detection field of view better than 2 m×3 m at an observation distance of 1.2 m. In this embodiment, the size of the filter used is a diameter of 22 mm and a thickness of 7 mm. As Figure 7 shown, the design of the filter uses the method of substrate absorption and coating interference to achieve the high rejection ratio characteristic, that is, a multilayer film of HfO2 and SiO2 is deposited on a fused silica substrate, and the deep cut-off rate requirement is achieved through process control. Figure 8The measured indicators are shown as follows. A single piece is better than OD7. Stacking two pieces can achieve a cut-off rate of OD14, and the transmittance is better than 35% @ 250nm - 270nm, meeting the index requirements of the system.

[0052] The ICMOS coupling structure unit 202 is connected to the ultraviolet optical lens unit 201. The ICMOS coupling structure unit 202 includes a coupled intensifier 2021, a light cone 2022, and a detector 2023. The cathode response band of the ICMOS coupling structure unit 202 is 200nm - 310nm, the cathode diameter is 18mm, and the cathode detection sensitivity is less than 3.0×10 -15 watt / cm 2 。

[0053] Both the visible light camera 301 and the ultraviolet optical lens unit 201 adopt ICMOS coupling design. Both the visible light camera 301 and the ultraviolet optical lens unit 201 have a field of view range exceeding 2m×3m at an observation distance of 1.2m.

[0054] The control unit 500 is used to control the ultraviolet optical imaging system 200 and the visible light imaging system 300.

[0055] The image processing unit 700 is used to collect and process images of the ultraviolet optical imaging system 200 and the visible light imaging system 300.

[0056] In the optical band, the ultraviolet optical band is relatively special, specifically manifested in its relatively high single-photon energy. When it interacts with matter, most of the photon energy will be absorbed by the matter. Therefore, for the ultraviolet band, especially for the solar-blind ultraviolet band of 250 - 270nm, the general common design method is to adopt a reflective system, that is, using fused silica or glass-ceramics as the substrate, processing a special surface shape with optical power, and plating a high-reflection film layer on this basis to achieve the regulation of light. However, the reflective system has disadvantages such as a small field of view and difficult alignment, so it is impossible to meet the detection requirements of a 110° field of view angle.

[0057] Currently, in the 250 - 270nm ultraviolet band, only fused silica and calcium fluoride can be used as lens materials, and the refractive indices of these two materials are relatively low. Therefore, for a wide-angle system, it is very difficult to correct monochromatic aberration and chromatic aberration. Considering that the substrate of the high rejection ratio filter is generally thick and exceeds the requirements of a super-wide angle of more than 100°, the system selects such as Figure 5The reverse telephoto structure shown. The optical system adopts a quasi-telecentric design in the image space to reduce the unevenness of the image plane illuminance, and its focal length, field of view, F-number, angular resolution, and size all meet the index requirements. The stray light and thermal analysis of the optical structure are also carried out, and it can meet the index requirements. Through simulation analysis, the angular resolution is better than 1° (the positioning accuracy is better than 3 cm), and its index meets the following requirements:

[0058] Operating wavelength range: 250 nm - 270 nm;

[0059] Field of view: 110° field of view, that is, at an observation distance of 1.2 m, the field of view range is better than 2 m × 3 m;

[0060] Positioning accuracy: better than 3 cm;

[0061] Detection imaging response time: better than 3 min.

[0062] As Figure 5 shown, the ultraviolet optical lens unit 201 further includes an adjusting washer assembly 2013, a retaining ring assembly 2014, an exhaust hole 2015, and a glue injection hole 2016. The adjusting washer assembly 2013 includes a plurality of adjusting washers, and the retaining ring assembly 2014 includes a plurality of retaining rings.

[0063] The lens barrel 2011 is in the shape of a horn with a large opening and a small bottom. The lens assembly 2012 is arranged in the lens barrel 2011 along the optical path. The lens assembly 2012 includes multiple groups of different lenses. An adjusting washer and a retaining ring are arranged between each group of lenses. An exhaust hole 2015 is arranged on the lens barrel 2011 between each group of lenses, and a glue injection hole 2016 is also arranged on the circumferential side of the lens barrel 2011.

[0064] Specifically, to ensure the reliability of the overall assembly of the ultraviolet optical lens unit 201, each group of lenses is separately designed with an adjusting washer and a retaining ring. The adjusting washer is used to conveniently correct the optical interval between the lenses, and the retaining ring can ensure that each lens does not loosen and is not affected by other lenses. The exhaust hole 2015 for the entire lens is separately designed, and an air guiding groove can also be arranged between each lens to ensure that there is no trapped air inside the lens.

[0065] The glue injection hole 2016 is designed on the periphery of the lens barrel 2011. After the assembly is completed, glue is injected through the glue injection hole 2016 for fixation to ensure optical reliability.

[0066] As Figure 6As shown in the figure, the ICMOS coupling structure unit 202 includes three parts: an intensifier 2021, an optical cone 2022, and a detector 2023, and the optical imaging surfaces of three structures are required for close coupling. In this embodiment, the ICMOS coupling structure unit 202 adopts a solar-blind double MCP image intensifier, an optical cone, and a CMOS detector. Its working process is as follows: After the incident photons undergo the cathode photoelectric effect, photoelectrons are emitted with a certain quantum efficiency. The photoelectrons are multiplied by the cascaded microchannel plates to form a charge cloud. The charge cloud is accelerated by the electric field, impacts on the fluorescent screen, and then is imaged and recorded by the image sensor. For ultraviolet band detection, a Hi-QE blue photocathode is used, and the MCP image intensifier adopts two V-type cascades with a gain multiple of 10 4 -10 6 . By adjusting the high voltage applied to the MCP image intensifier, different multiplication capabilities can be achieved to meet the detection of different radiation intensities. Among them, the MCP image intensifier selects a two-stage cascaded solar-blind double MCP, which has a good response to the solar-blind band. The MCP image intensifier and the image sensor are coupled through a high-throughput and low-distortion optical cone, minimizing the loss of light energy to the greatest extent.

[0067] According to the technical index requirements, the irradiance reaching the cathode of the MCP image intensifier after passing through the optical system is about 3.0×10 -15 watt / cm 2 , and the cathode sensitivity should be better than this value. The intensifier 2021 adopts a φ18mm high-sensitivity solar-blind double MCP image intensifier.

[0068] The optical cone 2022 is used for the size matching of the image of the intensifier 2021 and the CMOS detector, and its reduction ratio and size need to be determined according to the image plane size of the optical system at the cathode and the CMOS target plane size.

[0069] In this embodiment, according to the image plane size generated by the optical system and the CMOS target plane size, a customized optical cone with a reduction ratio of 2:1 and a transmittance > 40% is designed. In order to meet the coupling requirements of the ICMOS detector, the output end face of the optical cone is trimmed by 1mm according to the target plane size. The specific parameters of the optical cone 2022 are as Figure 9 shown. In this embodiment, the optical cone adopts a 2:1 small reduction ratio design, which can match the output size of the image intensifier with the CMOS target plane size, make full use of the CMOS target plane, and in addition to meeting the field of view requirements, can also improve the energy transmittance of the optical cone, while meeting the requirements of high-sensitivity detection.

[0070] In this embodiment, the technical indicators of the ICMOS coupling structure unit 202 are as follows:

[0071] 1) Cathode response band: 200nm - 310nm;

[0072] 2) Detection sensitivity: < 3.0×10 -15 watt / cm 2 , for the target radiation intensity, the response is greater than 100 / s;

[0073] 3) Integration time for a single image: ≤10 s;

[0074] 4) Output interface: GigE.

[0075] Optionally, the ICMOS coupling structure unit 202 further includes an ICMOS coupling structure, an ICMOS high-voltage control and telemetry module, a power supply module, and a camera communication control module.

[0076] The entire ICMOS coupling structure unit 202 uses a light cone coupling, so that the coupling efficiency of the system is relatively high, with a small volume and light weight, and has obvious advantages in low-light conditions. In order to reduce the risk of system engineering implementation, a gap coupling method is adopted, and the entire coupling process uses a collimator for real-time coupling monitoring to ensure that the coupling efficiency and spatial resolution of the system meet the requirements.

[0077] Considering that this system needs to undergo a mechanical shock test, in order to prevent collision between the output fiber optic panel of the intensifier and the CMOS fiber optic panel, the ICMOS coupling structure unit 202 is designed as a gap type, so that there is an air gap of about 20 um between the intensifier and the CMOS, ensuring the safety of the device during vibration or impact.

[0078] In this embodiment, the visible light camera 301 also needs to meet the requirements of the index field of view. Commercial lenses and cameras are selected. The lens uses KOWA-LM4HC, with a focal length of 4.7 mm, a C mount, and a corresponding field of view of 112.2°×95° when configuring the above detector. The camera selects the Huagu Power WP-GS1260 color camera, the detector is TBD, the target surface size is 13.1 mm×9.83 mm, and the corresponding field of view sizes are 3.3 m×2.5 m@1.2 m observation distance and 3.9 m×2.9 m@1.4 m observation distance, meeting the index requirements.

[0079] Optionally, the above high-sensitivity solar-blind and visible light dual-band wide-angle imaging system provided by the present invention further includes a box body 100, an interface unit 600, and a power supply component 800. The box body 100 is a sealed box with a height of 1.2 m and a bottom length and width of 2 m×3 m. In order to ensure the normal operation of the visible light camera 301, the box body 100 is equipped with LED lighting. The size and radiation intensity of the solar-blind ultraviolet target are as low as 1e 8 photons / s@3 cm×3 cm@260 nm±10 nm, and the illuminance reaching the target surface of the solar-blind ultraviolet detector is as low as 3e-15 w / cm 2, belonging to extremely weak radiation detection, the spatial distribution imaging detection and positioning problem of a solar-blind ultraviolet weak radiation source in a sealed box can be solved by this system, which cannot be achieved by using the existing technology.

[0080] As Figures 2 - 4 shown, a first window 101 and a second window 102 are arranged side by side on the box body 100. The ultraviolet optical imaging system 200 and the visible light imaging system 300 are respectively embedded in the first window 101 and the second window 102, and a handle 400 is arranged on the box body 100.

[0081] The interface unit 600 includes a first interface 601 and a second interface 602. The first interface 601 and the second interface 602 are arranged on the other side of the box body 100 opposite to the first window 101 and the second window 102. The first interface 601 and the second interface 602 are connected to the ultraviolet optical imaging system 200 and the visible light imaging system 300. The first interface 601 and the second interface 602 constitute the external electrical interface of the system, which includes: 1 switch, 1 220v mains interface, 1 network port, and 1 grounding post.

[0082] The power supply component 800 and the control unit 500 are both arranged in the box body 100. The power supply component 800 is electrically connected to the control unit 500, the ultraviolet optical imaging system 200, and the visible light imaging system 300 respectively. The power supply component 800 provides power support for the system.

[0083] Specifically, as Figures 2 - 4 shown, two sets of systems, namely the ultraviolet optical imaging system 200 and the visible light imaging system 300, are equipped on the box body 100. The two sets of systems are equipped with two types of lenses, namely an ultraviolet lens (i.e., the above-mentioned ultraviolet optical lens unit 201) and a visible light lens (i.e., the lens of the visible light camera 301). The center distance between the two types of lenses is 96 ± 0.1 mm.

[0084] A lens protection cover can be equipped at the front end of each lens. When not in use, the protection cover can be installed to protect the lens and avoid accidental damage. Each protection cover is equipped with 4 locking screws. The locking screws selected are knurled screws, which can be directly operated by hand to lock, and installation without tools is possible. A sliding rail can be installed under the adapter plate of the ultraviolet optical imaging system 200 and the visible light imaging system 300, so that the lenses of the two systems can move left and right, and manually switch to the same observation position to ensure that the centers of the images captured by the two systems are basically the same.

[0085] The solar-blind ultraviolet lens belongs to a large aberration optical system. Therefore, when evaluating its imaging ability, point resolution is generally used as an index. The main test method is to fix the lens on a turntable, so that the infinite far target emitted by the collimator passes through the solar-blind lens and converges on the cathode surface of the image intensifier. When the turntable angle is rotated, it is equivalent to the change of the incident light field of view. Therefore, when the turntable rotates 1 degree, if two points on the image plane can still be clearly resolved, the angular resolution is considered to reach 1 degree.

[0086] Using collimated light as the input, the system is placed at the center position of the optical axis perpendicular to the collimated light beam. Images are collected at 0° and 1° respectively, and then the two images are fused together to obtain an image as Figure 10 shown. Figure 10 It can be seen that the system can clearly resolve the collimated light at 0° and 1°, meeting the index requirement of angular resolution of 1°.

[0087] The control unit 500 can turn on, turn off, control the integration time and gain, and monitor the status of the system through the GigE interface.

[0088] The image processing unit 700 has the functions of image storage and display. It can continuously store images and has functions such as zooming in, zooming out, and contrast transformation during display; it also has the function of collecting and displaying multiple-frame image superposition; parameters such as the integration time of a single-frame image and the number of superpositions can be set through the image processing unit 700. The imaging method of short integration + multiple exposure accumulation is adopted in this system to improve the image signal-to-noise ratio.

[0089] Optionally, the image processing unit 700 includes a fluorescent screen for displaying images.

[0090] The control unit 500 is also used to adjust the screen voltage and telemetry of the fluorescent screen.

[0091] Optionally, the control unit 500 includes a control module and an electronic control module, and the power supply component 800 includes a high-voltage power supply. The high-voltage power supply provides high voltage for the fluorescent screen and the intensifier. The control module is used for command control telemetry, and the electronic control module is used for high-voltage regulation. The voltage range of the high-voltage power supply is 0 - 8000V.

[0092] Specifically, the high-voltage power supply can provide power for the coupling structure unit 202, serving as the MCP high-voltage power supply of the solar-blind double MCP image intensifier and the high-voltage power supply of the fluorescent screen. Currently, most ICMOS cameras can adjust the MCP high voltage, but generally do not have the function of remotely measuring the MCP high voltage. The system provided in this embodiment has the functions of screen voltage adjustment and telemetry, with more complete functions and more convenient operation.

[0093] In summary, the high-sensitivity solar-blind and visible light dual-band wide-angle imaging system provided by the present invention uses wide-angle dual-band imaging with a field of view angle exceeding 100 degrees, meeting the imaging requirements inside the sealed box, facilitating subsequent image fusion, and performing radiation spatial distribution detection and positioning; the system uses a narrow-band solar-blind ultraviolet optical system design with high transmittance and high out-of-band rejection ratio to improve the signal-to-noise ratio of the system; the system uses a high-sensitivity and lightweight ICMOS design with a double MCP with a diameter of 18 mm and a small-scale reduction optical cone to meet the requirements of weight and extremely weak signal detection; the system uses an imaging method of short integration + multiple exposure accumulation to improve the image signal-to-noise ratio; the system has a high-precision coupling structure design. While ensuring the safety of the detection target surface, the coupling distance between the MCP, the optical cone, and the CMOS detector is minimized as much as possible in the structural design to improve the resolution and energy transmission efficiency.

[0094] As described above, the above is only the optimal specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. Highly sensitive solar blind and visible light dual-band wide-angle imaging system, characterized in that: include: An ultraviolet optical imaging system, a visible light imaging system, a control unit and an image processing unit with parallel optical axis design, wherein the ultraviolet optical imaging system comprises an ultraviolet optical lens unit and an ICMOS coupling structure unit, and the visible light imaging system comprises a visible light camera; The ultraviolet optical lens unit comprises a lens barrel, a lens assembly and a filter, wherein the lens assembly is arranged on the lens barrel, and at least one filter is located on the optical path formed by the lens assembly, so that the working band of the ultraviolet optical lens unit is 250nm-270nm, the central wavelength is 260nm, and the field of view angle is greater than 100°; The ICMOS coupling structure unit is connected to the ultraviolet optical lens unit, and the ICMOS coupling structure unit includes a coupled enhancer, a light cone, and a detector. The cathode response band of the ICMOS coupling structure unit is 200nm-310nm, the cathode diameter is 18mm, and the cathode detection sensitivity is less than 3.0×10 -15 watt / cm 2 ; The visible light camera and the ultraviolet optical lens unit both adopt an ICMOS coupling design, and both the visible light camera and the ultraviolet optical lens unit have a field of view of more than 2m×3m at an observation distance of 1.2m; The control unit is used to control the ultraviolet optical imaging system and the visible light imaging system; The image processing unit is used to collect and process images of the ultraviolet optical imaging system and the visible light imaging system.

2. The high-sensitivity solar-blind and visible-light dual-band wide-angle imaging system according to claim 1, characterized in that: The optical filter adopts a multi-layer film structure, which is formed by a quartz substrate and hafnium dioxide and silicon dioxide plated on the quartz substrate. There are two optical filters, and the out-of-band cutoff of the two optical filters is OD14.

3. The high-sensitivity solar-blind and visible-light dual-band wide-angle imaging system according to claim 1, characterized in that: The ultraviolet optical lens unit further comprises an adjusting washer assembly, a pressing ring assembly, an exhaust hole and a glue injection hole, wherein the adjusting washer assembly comprises a plurality of adjusting washers, and the pressing ring assembly comprises a plurality of pressing rings; The lens barrel is trumpet-shaped with a large mouth and a small bottom. The lens assembly is arranged in the lens barrel along the optical path. The lens assembly includes multiple groups of lenses. Adjustment washers and pressure rings are arranged between each group of lenses. Exhaust holes are arranged on the lens barrel between each group of lenses. Glue injection holes are also arranged on the peripheral side of the lens barrel.

4. The high-sensitivity solar blind and visible light dual-band wide-angle imaging system according to claim 1, characterized in that: The intensifier is a day-blind dual MCP image intensifier with a diameter of 18 mm. The day-blind dual MCP image intensifier adopts two V-type cascades with a gain multiple of 10 4 -10 6 The cathode response band of the solar-blind dual MCP image intensifier is 200nm-310nm, the cathode diameter is 18mm, and the cathode detection sensitivity is <3.0×10-15watt / cm 2 ; The reduction ratio of the light cone is 2:1, and the transmittance is greater than 40%. The detector is a CMOS detector.

5. The high-sensitivity solar-blind and visible-light dual-band wide-angle imaging system according to any one of claims 1 to 4, characterized in that: Also includes a cabinet, an interface unit, and a power supply assembly; The box body is provided with a first window and a second window in parallel, and the ultraviolet optical imaging system and the visible light imaging system are respectively embedded in the first window and the second window; The interface unit includes a first interface and a second interface, wherein the first interface and the second interface are arranged on the box body on the opposite sides of the first window and the second window, and the first interface and the second interface are connected to the ultraviolet optical imaging system and the visible light imaging system respectively; The power supply assembly and the control unit are both arranged in the box, and the power supply assembly is electrically connected to the control unit, the ultraviolet optical imaging system and the visible light imaging system respectively.

6. The high-sensitivity solar-blind and visible-light dual-band wide-angle imaging system according to claim 5, characterized in that: The height of the box is 1.2m, the length and width of the bottom are 2mx3m, and a handle is provided on the box; The light cone is a customized light cone, and the design parameters of the customized light cone include the large end diameter, the small end diameter length, the light cone length, the horizontal center line projection length of the target after distortion on the CMOS target surface, and the vertical center line projection length of the target after distortion on the CMOS target surface. The large end diameter is 18 mm, the small end diameter length is 9 mm, the light cone length is 15 mm, the horizontal center line projection length of the target after distortion on the CMOS target surface is 8 mm, and the vertical center line projection length of the target after distortion on the CMOS target surface is 6.4 mm.

7. The high-sensitivity solar-blind and visible-light dual-band wide-angle imaging system according to claim 1, characterized in that: The detector is an ICMOS detector, which includes a CMOS detector, an ICMOS coupling structure, an ICMOS high-voltage control and telemetry module, a power supply module, and a camera communication control module.

8. The high-sensitivity solar-blind and visible-light dual-band wide-angle imaging system according to claim 6, characterized in that: The image processing unit comprises a fluorescent screen, and the fluorescent screen is used to display images; The control unit is also used for screen pressure adjustment and remote measurement of the fluorescent screen.

9. The high-sensitivity solar-blind and visible-light dual-band wide-angle imaging system according to claim 8, characterized in that: The control unit includes a control module and an electric control module. The power supply assembly includes a high-voltage power supply. The high-voltage power supply provides high voltage for the fluorescent screen and the intensifier. The control module is used for command control telemetry, and the electric control module is used for high-voltage regulation.

10. The high-sensitivity solar-blind and visible-light dual-band wide-angle imaging system according to claim 9, characterized in that: The voltage range of the high voltage power supply is 0-8000V.

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