Spectral imaging system

Abstract

The invention discloses a spectral imaging system, and the system comprises a light filtering assembly which comprises a plurality of light filtering units, and each light filtering unit allows a preset wave band in incident light in a target scene to pass through; the lens assembly is prepared through integral imaging, the lens assembly comprises a plurality of lenses, the contour of the joint of every two adjacent lenses is linear, and the lens assembly is used for focusing the light projected by the light filtering unit into a plurality of light beams; and the detector is used for receiving the optical signal of each light beam, converting the optical signal into an electric signal, generating a spectrogram according to the actual intensity of the electric signal, and determining the type of the to-be-detected gas in the target scene based on the spectrogram. Due to the fact that the lenses of the lens assembly are connected, no interval area exists between every two adjacent lenses, a mounting tool does not need to be considered, the interval between sub-aperture imaging areas of the detector is small, the pixel utilization rate of the detector is increased, the gas type detection precision is improved, and the size is reduced.

Description

Technical Field

[0001] This application relates to the field of spectral imaging technology, and in particular to a spectral imaging system. Background Technology

[0002] Many industries have production environments containing large quantities of flammable, toxic, and hazardous gases. Accurate and timely detection of these gases is crucial for preventing accidents and ensuring the safety of personnel and the environment. In recent years, with the development of technology, infrared imaging spectroscopy has gradually emerged and is playing an increasingly important role in the detection of hazardous gases.

[0003] Currently, spectral imaging for hazardous chemical gas detection often employs either field-view splitting with dispersive elements or aperture splitting with filters. When using field-view splitting with dispersive elements, light entering the system is split across the field of view, and then the dispersive elements disperse different wavelengths of light for propagation before being received by the detector. The detector generates a spectral image based on the intensity and distribution of the received light at different wavelengths. When using aperture splitting with filters, multiple different apertures perform initial light splitting. Different apertures receive light from different directions or regions. The light from each aperture is blocked by filters, allowing specific wavelengths of light to be received by the detector. The detector senses the intensity and wavelength of these wavelengths to generate a spectral image.

[0004] In the field-of-view splitting + dispersive element method, a larger dispersive element results in higher gas type resolution; therefore, spectrometers using this method are typically larger. The aperture-segmentation + filter method requires fixtures between different apertures. These fixtures divide the apertures and mount the lenses within the housing, resulting in gaps between adjacent apertures. This leads to lower detector pixel utilization and consequently reduces the detector's accuracy in identifying gas types. Due to the fixtures, spectrometers using this method are also relatively large. Both of these methods can only detect a single type of gas simultaneously. Therefore, a spectroscopic imaging system that can detect multiple gas types, has high accuracy, and is compact is needed. Summary of the Invention

[0005] In view of this, this application provides a spectral imaging system, the main purpose of which is to solve the problems of limited gas types, low accuracy and large size of current spectral imaging systems.

[0006] According to one aspect of this application, a spectral imaging system is provided, comprising: A light filtering assembly, comprising multiple light filtering units, each of which allows a preset wavelength band of incident light in a target scene to pass through, and the preset wavelength bands allowed to pass through by the multiple light filtering units are different from each other; A lens assembly is integrally formed by imaging. The lens assembly includes multiple lenses, and the contour of the connection between two adjacent lenses is straight. The lens assembly is used to focus the light projected by the filter unit into multiple beams. The detector is used to receive the optical signal of each beam and convert the optical signal into an electrical signal, generate a spectrum based on the actual intensity of the electrical signal, and determine the type of gas to be tested in the target scene based on the spectrum.

[0007] Optionally, the lens assembly is disposed opposite to the filter assembly, and each filter unit corresponds to one lens.

[0008] Optionally, the outer edge contour of the lens assembly is a closed shape formed by connecting multiple arcs.

[0009] Optionally, the longitudinal distance between the centers of two longitudinally adjacent lenses is the sum of the width of the sub-aperture imaging region and the distance between adjacent sub-aperture imaging regions, wherein the sub-aperture imaging region is the photosensitive area used by the detector to receive a light beam; The lateral distance between the centers of two horizontally adjacent lenses is the sum of the length of the sub-aperture imaging region and the distance between adjacent sub-aperture imaging regions.

[0010] Optionally, the distance between the center of each lens and the outer arc of the lens is the sub-aperture radius, which is the quotient of a preset total focal length, a preset magnification, and a preset aperture value.

[0011] Optionally, each of the lenses includes at least one focal point.

[0012] Optionally, the multiple lenses are divided into multiple groups, the focal points of the lenses in the same group are collinear along a first direction, and the adjacent two lenses in different groups are collinear along a second direction.

[0013] Optionally, the spectral imaging system further includes: a housing and an adapter, the lens assembly being mounted on the adapter, the adapter being movably connected within the housing, and the adapter being able to rotate within the housing along the circumferential direction of the lens assembly.

[0014] Optionally, the spectral imaging system further includes: an extinction component, which is disposed between the lens assembly and the detector. The extinction component includes multiple extinction units, each of which corresponds to one of the lenses. A first baffle is provided between adjacent extinction units. The extinction component is used to reduce stray light in the housing.

[0015] Optionally, the filter assembly further includes a frame, on which a plurality of sub-frames are provided, each sub-frame being provided with one filter unit, and a second baffle is provided between adjacent sub-frames.

[0016] By employing the above technical solutions, the technical solutions provided in the embodiments of this application have at least the following advantages: This application provides a spectral imaging system in which multiple lenses of a lens assembly focus the light transmitted through a filter unit into multiple beams. These beams illuminate a detector, which receives the optical signal from each beam and converts it into an electrical signal. Based on the actual intensity of these electrical signals, a spectral map is generated. The type of gas to be detected in the target scene is determined from the spectral map. Since the multiple lenses of the lens assembly are connected, there is no gap between adjacent lenses, eliminating the need for mounting fixtures. This results in a small gap between the sub-aperture imaging areas of the detector, increasing the detector's imaging area and improving the pixel utilization rate. Consequently, the accuracy of detecting the type of gas to be detected in the target scene is improved, while also reducing the size of the spectral imaging system. Because the multiple filter units allow different preset wavelengths to pass through, simultaneous detection of multiple gas types can be achieved.

[0017] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference symbols are used throughout the drawings to represent the same components. In the drawings: Figure 1 A structural diagram of a spectral imaging system provided in an embodiment of this application is shown; Figure 2 A schematic diagram of the center of a lens in a spectral imaging system provided in an embodiment of this application is shown.

[0019] in, In the diagram: 11-Filter assembly; 12-Lens assembly; 13-Detector. Detailed Implementation

[0020] The present application will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present application can be combined with each other.

[0021] To further illustrate the technical means and effects adopted by this application to achieve the intended inventive purpose, the specific implementation methods, structures, features, and effects according to this application are described in detail below with reference to the accompanying drawings and preferred embodiments. In the following description, different "an embodiment" or "an embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0022] A multi-aperture + filtering spectral imaging system mainly consists of a multi-aperture lens assembly, a filter assembly, and a detector. Each aperture of the lens assembly is fitted with a sub-lens, and multiple sub-lenses are arranged according to a specific pattern, such as a two-dimensional matrix or other specific array forms. Each sub-lens corresponds to a specific aperture and filter channel, and transmits light of a preset wavelength through the sub-lens to achieve imaging of a preset spectral band.

[0023] Gas molecules are composed of atoms linked by chemical bonds, and these molecules are in constant motion, including translation, rotation, and vibration. When infrared light or other light containing infrared light irradiates a gas, if the photon energy of the infrared light is exactly equal to the energy level difference of a certain vibrational mode of the gas molecule, the gas molecule can absorb the photon energy of the infrared light. The wavelength range of the infrared light or other light containing infrared light will then lack the wavelength range that the gas can absorb. Different gas molecules have different vibrational frequencies due to differences in atomic composition, chemical bond type, and molecular structure, and therefore absorb infrared light in different wavelength ranges. For example, carbon monoxide molecules mainly have one stretching vibration mode, and the infrared wavelength corresponding to its vibrational frequency is approximately 4.67 µm; while carbon dioxide molecules have multiple modes, including symmetric stretching vibration, asymmetric stretching vibration, and bending vibration, and their infrared absorption wavelength is mainly around 2.7 µm. 、 4.3µm and 15µm.

[0024] In a spectral imaging system, light in the detection scene passes through the gas to be measured and then illuminates a lens assembly. The lens assembly focuses the light onto a filter assembly, which allows light of a preset wavelength to pass through. The light passing through the filter assembly then illuminates the detector. The detector receives the optical signal and converts it into an electrical signal. Based on the intensity of the electrical signal, it generates a spectrum, and the type of gas to be measured is determined from the spectrum.

[0025] When using a multi-aperture + filter method for spectral imaging, the multiple sub-lenses in the lens assembly are independent of each other. Each sub-lens needs to be installed in the housing of the spectral imager using a fixture. Therefore, there is space for the fixture to be installed between two adjacent sub-lenses. The light transmission area of ​​the lens assembly is reduced, and the light received by the detector is also reduced, resulting in a relatively low pixel utilization rate of the detector. This will reduce the accuracy of the detector in identifying the type of gas. Due to the presence of the fixture, the size of the multi-aperture + filter method for spectral imaging is also relatively large.

[0026] To address the problems of limited gas detection capabilities, low accuracy, and large size in current spectral imaging systems, embodiments of this application provide a spectral imaging system, such as... Figure 1 As shown, it includes: The filter assembly 11 includes multiple filter units, each filter unit allows a preset wavelength band in the incident light in the target scene to pass through, and the preset wavelength bands allowed to pass through by the multiple filter units are different from each other; Lens assembly 12 is integrally formed by imaging. Lens assembly 12 includes multiple lenses. The contour of the connection between two adjacent lenses is straight. Lens assembly 12 is used to focus the light projected through the filter unit into multiple beams. Detector 13 is used to receive the optical signal of each beam and convert the optical signal into an electrical signal. It generates a spectrum based on the actual intensity of the electrical signal and determines the type of gas to be tested in the target scene based on the spectrum.

[0027] When performing gas detection using a spectral imaging system, the actual environment in which the gas is detected is the target scene. The target scene can be a specific environment, a pre-defined detection environment, or the actual environment to be detected. It can be an indoor space, an industrial plant, an outdoor atmospheric environment, a mine, or any other actual location where the gas to be measured might be present. These actual locations contain natural light, such as sunlight or artificial light, which includes infrared light. Some objects in these locations also emit infrared light; therefore, the light in the target scene exists in the infrared band.

[0028] The wavelength range of infrared light is roughly between 0.76µm and 1000µm. This range can be further subdivided into three regions: near-infrared (NIR), mid-infrared (MIR), and far-infrared (FIR). Filter components allow light to pass through in these regions. Near-infrared light has a wavelength range of 0.76µm to 3µm, mid-infrared light typically ranges from 3µm to 30µm, and far-infrared light ranges from 30µm to 1000µm. Different gases have different molecular structures and vibrational frequencies. Gases can only absorb infrared light whose vibrational frequency matches their own. Therefore, different gases absorb different wavelengths of infrared light. Based on the vibrational frequency of the gas being detected, the wavelength of light that the filter component can pass through is determined. The filter component selectively allows light within a specific wavelength range to pass through, thereby separating the band of interest. For example, a filter component may allow light with a preset wavelength of 7-14µm to pass through.

[0029] The filter assembly includes multiple filter units with different preset wavelengths. Depending on the type of gas to be measured, the wavelength range of light that can pass through is narrowed. For example, the first filter unit is set to allow light of 7µm-9µm to pass through, the second filter unit is set to allow light of 9µm-10.5µm to pass through, and the third filter unit is set to allow light of 10.5µm-12µm to pass through.

[0030] The lens is a convex lens, which is a lens that is thicker in the center than at the edges. A lens assembly consists of multiple lenses, each focusing incident light into a smaller area to generate a single beam. These lenses are essentially sub-lenses, and each lens is a convex lens. For example, one surface of the lens might be an outwardly convex spherical surface, while another surface might be an inwardly concave surface; therefore, the outer edge of the lens is rounded. Figure 1 The lens assembly shown has lenses with arc-shaped outer edges and one concave surface, with the central circle representing the bottom of the concave surface. The lens assembly is fabricated as a single unit, with adjacent lenses connected. Each lens is composed of an arc shape and multiple straight lines, and the outer edge of the connecting surface between adjacent lenses is straight. Therefore, no tooling is needed between adjacent lenses, increasing the incident area of ​​the lens assembly, which is equivalent to increasing the light-receiving area of ​​the detector and further improving the utilization rate of the pixels on the detector.

[0031] Each lens receives light transmitted through the filter assembly and focuses it onto a region of the detector, serving as a sub-aperture imaging region. The detector receives the optical signal and converts it into an electrical signal.

[0032] Detectors utilize the photoelectric effect to operate. When light shines on the surface of the photosensitive material of the detector, the photon energy is absorbed by electrons in the material. If the photon energy is large enough, the electrons can overcome the material's binding force and escape, generating a photocurrent. For example, a photomultiplier tube (PMT) consists of a photocathode, a dynode, and an anode. When light shines on the photocathode, it emits photoelectrons. These photoelectrons are accelerated and collide with the dynodes under the influence of the electric field between them. Each collision excites more electrons, and after multiple multiplications, a large number of electrons eventually reach the anode to form a detectable current signal. Similarly, photodiodes (PDs) and avalanche photodiodes (APDs) absorb photon energy when light shines on the PN junction region, generating electron-hole pairs. These charge carriers move directionally under the influence of the electric field, forming a photocurrent.

[0033] After the detector converts the optical signal into an electrical signal, it obtains the intensity of the electrical signal, which is linearly related to the intensity of the incident light. The detector performs intensity correction or normalization on these electrical signal intensities, mapping the intensity values ​​to a specific range. Each pixel on the detector corresponds to a wavelength. A two-dimensional coordinate system is established with wavelength as the abscissa and electrical signal intensity as the ordinate to plot the spectrum.

[0034] A grating or prism can split the light transmitted through a lens, allowing it to propagate to the corresponding positions on the detector in order of wavelength. Filter components can also achieve this splitting. When a filter component splits the light, it utilizes the propagation characteristics of light in a medium. Different wavelengths of light travel at different speeds within the same medium, resulting in different distances traveled (optical path) in the same propagation time. Because the filter has a certain thickness, the "retention" time and distance traveled by different wavelengths within the filter vary. Therefore, when the light exiting the filter is focused by the optical system, it arrives at different positions on the detector's image plane, achieving the splitting of the light. The split light then illuminates the designated pixels on the detector according to their wavelength.

[0035] Because the detector receives light lacking the infrared band absorbed by the gas, the resulting spectrum is missing this infrared band. Therefore, the detector's spectrum is compared to a standard spectrum of a specific gas. If the standard spectrum of a gas perfectly matches the missing portion of the detector's spectrum, the gas to be detected is identified as that specific gas. The standard spectra of the target gas are obtained from spectral databases, which contain a large amount of standard spectral data for common gases.

[0036] This application provides a spectral imaging system. Compared with the prior art, the multiple lenses of the lens assembly focus the light transmitted by the filter unit into multiple beams. These multiple beams illuminate the detector, which receives the optical signal of each beam and converts it into an electrical signal. A spectral map is generated based on the actual intensity of these electrical signals. The type of gas to be detected in the target scene is determined based on the spectral map. Since the multiple lenses of the lens assembly are connected, there is no gap between adjacent lenses, eliminating the need to consider mounting fixtures. This results in a small gap between the sub-aperture imaging areas of the detector, increasing the detector's imaging area and improving the pixel utilization rate. Consequently, the accuracy of detecting the type of gas to be detected in the target scene is improved, while also reducing the size of the spectral imaging system. Because the multiple filter units allow different preset wavelengths to pass through, the simultaneous detection of multiple gas categories can be achieved.

[0037] In one embodiment of this application, the lens assembly 12 is disposed opposite to the filter assembly 11, and each filter unit corresponds to one lens.

[0038] In this embodiment, the preset wavelengths allowed by the multiple filter units are different from each other. The number of filter units is the same as the number of lenses, and the position of each filter unit corresponds to the position of a lens. This is so that when the preset wavelengths allowed by the filter units are different, the light transmitted by the filter units is incident on the corresponding lens, reducing the amount of light of other wavelengths incident on the lens and improving the purity of the light.

[0039] In one embodiment, the outer edge contour of the lens assembly 12 is a closed shape formed by connecting multiple arcs.

[0040] Specifically, each lens is shaped by an arc and multiple straight lines, with the arcs of each lens connected together to form a closed shape.

[0041] Each lens corresponds to a center, which is the center of the circle containing the arc of the lens. Each lens is defined by the circle corresponding to its arc; therefore, it's necessary to determine the center and radius of the circle corresponding to each lens. The center is the lens's eccentricity, and the radius is the lens's corresponding sub-aperture. The circles corresponding to two adjacent lenses intersect, and the straight line connecting two adjacent lenses is the intersection line of their corresponding circles and its extension.

[0042] In one embodiment, the longitudinal distance between the centers of two longitudinally adjacent lenses is the sum of the width of the sub-aperture imaging region and the distance between adjacent sub-aperture imaging regions, where the sub-aperture imaging region is the photosensitive area used by the detector when receiving a beam of light. The lateral distance between the centers of two horizontally adjacent lenses is the sum of the length of the sub-aperture imaging region and the distance between adjacent sub-aperture imaging regions.

[0043] Specifically, the size of the sub-aperture imaging area of ​​the detector and the distance between two adjacent sub-aperture imaging areas are determined. For example, if the number of sub-aperture pixels is 600×500 and the size of each pixel is 15µm×15µm, then the size of the sub-aperture imaging area is (600×15µm)×(500×15µm)=9mm×7.5mm. The distance between two adjacent sub-aperture imaging areas is 750µm. Then the longitudinal distance between the centers of two adjacent lenses is 7.5+0.75=8.25mm, and the lateral distance between the centers of two adjacent lenses is 9+0.75=9.75mm.

[0044] Taking six lenses as an example, a two-dimensional coordinate system is constructed with the center of the lens assembly as the origin. The vertical distance between the centers of two adjacent lenses, 8.25mm, is divided by 2 to obtain 4.125. 4.125 is used as the ordinate of each lens in the positive y-axis direction, and -4.125 is used as the ordinate of each lens in the negative y-axis direction. 0 is used as the x-coordinate of two lenses, resulting in coordinates of (0, 4.125) and (0, -4.125). Since the x-coordinate difference between the centers of these two lenses is 9.75, the coordinates of the remaining four lenses are (9.75, 4.125), (-9.75, 4.125), (9.75, -4.125), and (-9.75, -4.125). This determines the center of each lens. Figure 2 As shown.

[0045] In one embodiment, the distance between the center of each lens and the outer arc of the lens is the sub-aperture radius, which is the quotient of a preset total focal length, a preset magnification, and a preset aperture value.

[0046] Specifically, since the shape of each lens is composed of an arc and multiple straight lines, the radius corresponding to the circle containing the arc is the sub-aperture radius of the lens.

[0047] In one embodiment, the sub-aperture radius is calculated using the following method. Based on the design specifications, the spatial resolution of the spectral imager is determined to be 0.5 mrad, the aperture value is 1, the sub-aperture pixel is 600×500, the front-end telescope system uses 3x magnification, and the pixel pitch is 15 µm.

[0048] The total focal length of the system is f′ = pixel pitch / spatial resolution = 15 µm / 0.56 mrad = 26.79 mm Sub-aperture focal length is f′ 子孔径 =f′ / -magnification=26.79mm / -3 mm = 8.93 mm The sub-aperture diameter is D 子孔径 =f′ 子孔径 Aperture value = 8.93mm / 1 = 8.93mm Field of view: Horizontal field of view angle = arctan 600 × 15 µm / 2 / 8.93 mm = 26 degrees Vertical field of view = arctan 500 × 15 µm / 2 / 8.93 mm = 22 degrees Since there are no tooling fixtures between the lenses of the lens assembly, the light-transmitting area of ​​the lenses increases, the area on the detector that receives light also increases, and the sub-aperture imaging area also increases. Since the field of view is calculated based on the length and width of the sub-aperture imaging area, the spectral imager of this application also increases the field of view.

[0049] In one embodiment, each lens includes at least one focal point, and multiple lenses are divided into multiple groups. The focal points of lenses within the same group are collinear along a first direction, and adjacent lenses between different groups are collinear along a second direction.

[0050] Specifically, for a convex lens, when light rays parallel to the principal axis pass through the lens, they converge at a point on the principal axis; this point is the focal point of the convex lens. For example, when a beam of parallel light (such as sunlight) shines on a convex lens, the light rays, after refraction by the lens, converge into a bright point on the principal axis on the other side of the lens; this point is the focal point. The focal point of a convex lens determines its ability to converge light rays. The focal point also determines key parameters such as the lens's magnification and imaging distance. By adjusting the distance between the lens and the object, the position of the focal point can be changed, thereby achieving different imaging effects. In this application, each lens includes at least one focal point. Light rays passing through the lens converge at the focal point, concentrating the energy of the light in a smaller area, thereby increasing the light intensity.

[0051] Multiple focal points lying on the same straight line are collinear. For example, consider six lenses arranged in a 2×3 grid. Assume three lenses in a horizontal row, A, B, and C, with focal point Fa1, Fb1, and Fc1 respectively. The focal points Fa1, Fb1, and Fc1 lie on the same straight line and are collinear along a first direction. Then, consider two lenses in a vertical row, A and D, with focal point Fd1. The focal points Fa1 and Fd1 lie on the same straight line and are collinear along a second direction.

[0052] By using collinear focal points, lenses can focus light more precisely to the desired location, reducing the dispersion and loss of light in non-focusing areas and improving the efficiency of light energy utilization.

[0053] In one embodiment, the spectral imaging system further includes a housing and an adapter, wherein the lens assembly is mounted on the adapter, the adapter is movably connected within the housing, and the adapter is rotatable within the housing along the circumferential direction of the lens assembly.

[0054] Specifically, in traditional spectral imaging systems, lenses are installed inside a housing using fixtures. The fixtures between adjacent sub-lenses reduce the light transmission area of ​​the sub-lenses. In this application, no fixtures are required between the lenses. The lens assembly is installed on an adapter, which is installed inside the housing to install the lens assembly. At the same time, the adapter can rotate inside the housing, and the rotation of the adapter drives the rotation of the lens to achieve lens adjustment.

[0055] In one embodiment, the spectral imaging system further includes: an extinction component disposed between the lens assembly and the detector, the extinction component including a plurality of extinction units, each extinction unit corresponding to a lens, a first baffle being provided between adjacent extinction units, the extinction component being used to reduce stray light in the housing.

[0056] Specifically, optical components such as lenses may develop defects like scratches, wear, and bubbles during manufacturing, transportation, or use. These defects cause irregular scattering and reflection of light on their surfaces, resulting in stray light. In addition, dust and other contaminants on the surface of optical components can also cause scattering and reflection of incident light, increasing stray light. Even tiny dust particles can significantly interfere with the optical path, especially in high-precision spectral measurements. Furthermore, ambient light entering the spectral imaging system can interfere with measurements, creating stray light. Even weak ambient light can generate significant background signals on the detector, affecting the signal-to-noise ratio of the spectrum, especially when measuring weak spectral signals.

[0057] Therefore, eliminating stray light is crucial in the operation of a spectral imaging system. Stray light increases the background signal of the spectrum, causing the target spectral signal to be submerged in noise. Extinction components effectively block and absorb unwanted stray light that the detector cannot receive, preventing crosstalk between adjacent channels and attenuating this stray light to a level acceptable to the detector. This results in more stable and reliable spectral data, improving the accuracy and repeatability of measurement results. Simultaneously, it avoids problems such as decreased detector gain, increased noise, or even damage caused by stray light, ensuring stable and accurate detector operation, extending detector lifespan, and reducing the maintenance costs of the spectral imaging system.

[0058] In one embodiment, the filter assembly further includes a frame with multiple sub-frames, each sub-frame having a filter unit, and a second baffle between adjacent sub-frames.

[0059] Specifically, a filter assembly can allow only light within a specific wavelength range to pass through, thus performing a filtering function. The filter assembly includes multiple filter units, each with a preset wavelength band different from the others. Adjacent filter units are separated by sub-frames to prevent crosstalk. For example, the filter unit on the first sub-frame can allow light of 7 µm-9 µm to pass through; the filter unit on the second sub-frame can allow light of 9 µm-11 µm to pass through.

[0060] Placing a second baffle between adjacent sub-frames effectively blocks stray light from propagating between different filter units. When light passes through a filter unit, it may generate reflected or scattered light. If this light enters the next filter unit, it becomes stray light. The second baffle can prevent the propagation of this stray light, reducing its interference with subsequent filtering processes and the final optical signal. For example, after light passes through the first filter unit, a small amount of light of non-target wavelengths may be reflected back. The second baffle can prevent this reflected light from entering adjacent filter units, thereby improving the overall system's ability to suppress stray light and resulting in clearer imaging quality. After filtering by multiple sub-frames and protecting with the second baffle, the optical signal reaching the detector has higher purity and is not affected by stray or harmful light, thus improving the quality of the optical signal.

[0061] In addition, the design of multiple sub-frames allows for easy replacement or adjustment of the filter units. If a change in the light filtering strategy is required, only the filter unit on the corresponding sub-frame needs to be replaced, without requiring a large-scale modification of the entire optical system. This structure also facilitates system expansion, allowing the addition of new sub-frames and filter units as needed to achieve more complex light filtering functions.

[0062] The above embodiments are merely exemplary embodiments of this application and are not intended to limit this application. The scope of protection of this application is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this application within its substance and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of this application.

Claims

1. A spectral imaging system, characterized in that: include: A filter assembly, the filter assembly comprising a plurality of filter units, each of the filter units allowing a preset wavelength band of incident light in a target scene to pass through, and the preset wavelength bands allowed to pass through by the plurality of filter units are different from each other; A lens assembly, wherein the lens assembly is formed by integrated imaging, the lens assembly comprises a plurality of lenses, and the contour of the connection between two adjacent lenses is a straight line, and the lens assembly is used to focus the light projected through the filter unit into a plurality of light beams; The detector is used to receive the optical signal of each light beam and convert the optical signal into an electrical signal, generate a spectrum according to the actual intensity of the electrical signal, and determine the type of the gas to be detected in the target scene based on the spectrum.

2. The spectral imaging system according to claim 1, characterized in that: The lens assembly is arranged opposite to the filter assembly, and each filter unit corresponds to one lens.

3. The spectral imaging system according to claim 1, characterized in that: The outer edge contour of the lens assembly is a closed figure formed by connecting a plurality of circular arcs.

4. The spectral imaging system according to claim 1, characterized in that: The longitudinal distance between the centers of two longitudinally adjacent lenses is the sum of the width of the sub-aperture imaging area and the distance between adjacent sub-aperture imaging areas, wherein the sub-aperture imaging area is a photosensitive area used when the detector receives a light beam; The lateral distance between the centers of two laterally adjacent lenses is the sum of the length of the sub-aperture imaging region and the distance between adjacent sub-aperture imaging regions.

5. The spectral imaging system according to claim 3, characterized in that: The distance between the center of each lens and the arc-shaped outer edge of the lens is the sub-aperture radius, and the sub-aperture radius is the quotient of a preset total focal length, a preset magnification, and a preset aperture value.

6. The spectral imaging system according to claim 1, characterized in that: Each of the lenses includes at least one focal point.

7. The spectral imaging system according to claim 1, characterized in that: The plurality of lenses are divided into a plurality of groups, the focal points of the lenses in the same group are collinear along a first direction, and the focal points of two adjacent lenses in different groups are collinear along a second direction.

8. The spectral imaging system according to any one of claims 1 to 7, characterized in that: The spectral imaging system further comprises: a housing and an adapter, the lens assembly is clamped on the adapter, the adapter is movably connected in the housing, and the adapter can rotate in the housing along the circumferential direction of the lens assembly.

9. The spectral imaging system according to claim 8, characterized in that: The spectral imaging system also includes: an extinction component, which is arranged between the lens assembly and the detector. The extinction component includes a plurality of extinction units, each of which corresponds to one of the lenses, and a first baffle is provided between adjacent extinction units. The extinction component is used to reduce stray light in the housing.

10. The spectral imaging system according to any one of claims 1 to 7, characterized in that: The filter assembly further comprises a frame, a plurality of sub-frames are arranged on the frame, one of the filter units is arranged on each sub-frame, and a second baffle is arranged between adjacent sub-frames.

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