A four-channel polarimetric imaging system

Abstract

This invention discloses a four-channel polarization imaging system, comprising a housing containing four acquisition channels. These channels are respectively equipped with a near-infrared multispectral imaging camera, a near-infrared light field imaging camera, a visible light imaging camera, and an infrared imaging camera for multi-dimensional imaging and detection of objects. The near-infrared multispectral imaging camera has an adjustable filter that transmits light of different wavelengths. The near-infrared light field imaging camera has a polarization device that polarizes the light before imaging. The visible light imaging camera acquires and images light within the visible wavelength range. The infrared imaging camera acquires and images light within the infrared wavelength range. This invention can acquire light of different wavelengths, intensities, and polarization states, and image light with different properties, thereby enabling multi-dimensional imaging and detection of objects.

Description

Technical Field

[0001] This invention belongs to the technical field of spectral imaging cameras and relates to a four-channel polarization imaging system. Background Technology

[0002] Light waves contain a wealth of information. By collecting and imaging different light rays based on their wavelength, polarization state, and intensity, different images can be obtained. Existing imaging systems typically can only collect a single, specific type of light ray, such as imaging visible light. Current imaging systems cannot obtain different images based on the different properties of light rays, making it difficult to perform multi-dimensional imaging and detection of objects.

[0003] Therefore, in order to address the shortcomings of existing imaging systems that only provide single-channel imaging, this invention discloses a four-channel polarization imaging system. Summary of the Invention

[0004] The purpose of this invention is to provide a four-channel polarization imaging system that can collect light of different wavelengths, intensities, and polarization states, and image light of different properties, thereby enabling multi-dimensional imaging detection of objects.

[0005] This invention is achieved through the following technical solution:

[0006] A four-channel polarization imaging system includes a housing containing four acquisition channels. These channels house a near-infrared multispectral imaging camera, a near-infrared light field imaging camera, a visible light imaging camera, and an infrared imaging camera, respectively, for multi-dimensional imaging and detection of objects. The near-infrared multispectral imaging camera contains an adjustable filter that transmits light of different wavelengths. The near-infrared light field imaging camera contains a polarization device that polarizes the light for imaging. The visible light imaging camera acquires and images light within the visible wavelength range. The infrared imaging camera acquires and images light within the infrared wavelength range.

[0007] To better realize the present invention, the near-infrared multispectral imaging camera further includes a front lens assembly, a filter assembly, a rear lens assembly, and an imaging assembly coaxially and sequentially arranged inside the lens barrel. The front lens assembly is used to adjust the light transmission to an angle of less than or equal to 1° with the axis. The filter assembly is used to automatically selectively transmit light within a specific wavelength range. The rear lens assembly is used to adjust the light to be within the effective imaging light range of the near-infrared multispectral imaging device. The imaging assembly is axially movable relative to the exit end of the rear lens assembly to achieve axial movement focusing imaging of the imaging assembly itself. At least one grating structure for blocking stray light is arranged inside the lens barrel along the optical path.

[0008] The camera is constructed by segmenting and stitching together a front lens assembly, a filter assembly, a rear lens assembly, and a near-infrared multispectral imaging device. The front and rear lens assemblies are used to adjust the angle between the light rays and the lens's central axis, thereby ensuring that as much light as possible enters the imaging surface of the near-infrared multispectral imaging device. The front lens assembly adjusts the light transmission to an angle of less than or equal to 1° with the axis. The light, after being adjusted by the front lens assembly, continues to pass through the filter assembly, which selectively transmits light within a specific wavelength range, achieving selective filtering. Simultaneously, the filtering parameters of the filter assembly are automatically controlled by an external controller, achieving automatic filtering. Different target objects have different spectral characteristics, and adjustable filters can be used to transmit light of different wavelengths based on the object's characteristics. The light, after being filtered by the filter assembly, continues to pass through the rear lens assembly, where it is adjusted to fall within the effective imaging light range of the near-infrared multispectral imaging device. Finally, the light is transmitted onto the imaging surface of the near-infrared multispectral imaging device to achieve imaging. The near-infrared multispectral imaging device can move axially closer to or further away from the rear lens assembly, thereby adjusting the focal length between the emitting end of the rear lens assembly and the imaging surface of the near-infrared multispectral imaging device, thus achieving the focusing function.

[0009] To better realize the present invention, further, the incident end of the filter component is provided with a light hole and a threaded hole coaxially along the optical axis direction. The light hole is connected to the exit end shaft hole of the front lens component, and the threaded hole is connected to the exit end of the front lens component in a threaded connection. The exit end of the filter component is provided with a light hole, and the light hole is connected to the incident end shaft hole of the rear lens component.

[0010] The optical aperture at the entrance of the filter assembly is fitted with the axial hole at the exit of the front lens assembly, thus ensuring the coaxiality between the filter assembly and the front lens assembly. Simultaneously, the threaded hole at the entrance of the filter assembly is threadedly fitted with the exit of the front lens assembly, making the connection between the filter assembly and the front lens assembly more secure and preventing loosening.

[0011] To better realize the present invention, the front lens assembly further includes a front lens barrel, a convex lens group, and a concave lens group; the front lens barrel has an incident end with a convex lens group, which includes a first near-infrared multispectral biconvex lens and a second near-infrared multispectral biconvex lens coaxially disposed at the incident end of the front lens barrel; the incident end of the front lens barrel has a first positioning step inside, and the exit end of the front lens barrel has a second positioning step inside; the first near-infrared multispectral biconvex lens is axially and circumferentially engaged with the first positioning step, and the second near-infrared multispectral biconvex lens is axially and circumferentially engaged with the second positioning step; the concave lens group includes a first near-infrared multispectral biconcave lens and a second near-infrared multispectral biconcave lens coaxially disposed at the exit end of the front lens barrel; the exit end of the front lens barrel has a third positioning step and a fourth positioning step inside; the first near-infrared multispectral biconcave lens is axially and circumferentially engaged with the third positioning step, and the second near-infrared multispectral biconcave lens is axially and circumferentially engaged with the fourth positioning step.

[0012] The convex lens group is used to quickly converge light, allowing as much light as possible to enter the front lens barrel and avoiding light loss. The concave lens group diverges the light converged by the convex lens group, ensuring that the angle between the incident light and the optical axis meets the effective working angle range of the filter assembly.

[0013] The axial end face of the first positioning step engages with the end of the first near-infrared multispectral biconvex lens for axial positioning, thereby achieving axial positioning of the first near-infrared multispectral biconvex lens. The inner circumferential surface of the first positioning step engages with the circumferential side surface of the first near-infrared multispectral biconvex lens for circumferential positioning, thereby achieving circumferential positioning of the first near-infrared multispectral biconvex lens. Similarly, the axial end face of the second positioning step engages with the end of the second near-infrared multispectral biconvex lens for axial positioning, thereby achieving axial positioning of the second near-infrared multispectral biconvex lens. The inner circumferential surface of the second positioning step engages with the circumferential side surface of the second near-infrared multispectral biconvex lens for circumferential positioning, thereby achieving circumferential positioning of the second near-infrared multispectral biconvex lens.

[0014] The axial end face of the third positioning step engages with the end of the first near-infrared multispectral biconcave lens for axial positioning, thereby achieving axial positioning of the first near-infrared multispectral biconcave lens. The inner circumferential surface of the third positioning step engages with the circumferential side surface of the first near-infrared multispectral biconcave lens for circumferential positioning, thereby achieving circumferential positioning of the first near-infrared multispectral biconcave lens. Similarly, the axial end face of the fourth positioning step engages with the end of the second near-infrared multispectral biconcave lens for axial positioning, thereby achieving axial positioning of the second near-infrared multispectral biconcave lens. The inner circumferential surface of the fourth positioning step engages with the circumferential side surface of the second near-infrared multispectral biconcave lens for circumferential positioning, thereby achieving circumferential positioning of the second near-infrared multispectral biconcave lens.

[0015] To better realize the present invention, further, a first threaded retaining ring is provided on the side of the first near-infrared multispectral biconvex lens away from the first positioning step to press the first near-infrared multispectral biconvex lens toward the first positioning step, and a second threaded retaining ring is provided on the side of the second near-infrared multispectral biconvex lens away from the second positioning step to press the second near-infrared multispectral biconvex lens toward the second positioning step; both the inner walls of the first and second threaded retaining rings are provided with near-infrared multispectral retaining ring grating structures, the near-infrared multispectral retaining ring grating structures include a light-blocking flange provided on the inner wall of the first or second threaded retaining ring and a slope that transitions to the light-blocking flange, by providing the slope and the light-blocking flange, stray light can be blocked.

[0016] The first near-infrared multispectral biconvex lens is axially pressed against the first positioning step by a first threaded retaining ring. This, combined with the axial positioning of the first near-infrared multispectral biconvex lens by the first positioning step, achieves axial fixation of the first near-infrared multispectral biconvex lens. Simultaneously, the axial pressing force of the first threaded retaining ring restricts the circumferential movement of the first near-infrared multispectral biconvex lens, ensuring a tight and stable installation of the first near-infrared multispectral biconvex lens inside the front lens barrel. Similarly, the second near-infrared multispectral biconvex lens is axially pressed against the second positioning step by a second threaded retaining ring. This, combined with the axial positioning of the second near-infrared multispectral biconvex lens by the second positioning step, achieves axial fixation of the second near-infrared multispectral biconvex lens. Simultaneously, the axial pressing force of the second threaded retaining ring restricts the circumferential movement of the second near-infrared multispectral biconvex lens, ensuring a tight and stable installation of the second near-infrared multispectral biconvex lens inside the front lens barrel.

[0017] To better realize the present invention, the rear lens assembly further includes a rear lens barrel, a rear convex lens group is disposed inside the incident end of the rear lens barrel, and a rear concave-convex lens group is disposed inside the exit end of the rear lens barrel; the rear convex lens group includes a third near-infrared multispectral biconvex lens disposed at the incident end of the rear lens barrel, and the rear concave-convex lens group includes a near-infrared multispectral cemented concave-convex lens disposed at the exit end of the rear lens barrel; the exit end of the rear lens barrel is connected to the incident end of the near-infrared multispectral imaging device through a focusing part, and the focusing part is used to drive the near-infrared multispectral imaging device to move axially closer to or away from the exit end of the rear lens barrel.

[0018] The rear convex lens group is used to quickly converge light, allowing as much light as possible to pass through the rear concave-convex lens group. This group adjusts the angle between the light rays and the axis to less than or equal to 1°, ensuring the light rays are incident on the imaging surface of the near-infrared multispectral imaging device in a direction nearly parallel to the axis, thus guaranteeing the final imaging effect. The exit end of the rear lens barrel is connected to the entrance end of the near-infrared multispectral imaging device via a focusing unit. This focusing unit allows the near-infrared multispectral imaging device to move closer to or further away from the rear lens assembly along the axis, thereby adjusting the imaging focal length.

[0019] To better realize the present invention, a fifth positioning step is further provided inside the incident end of the rear lens barrel, and a sixth positioning step is provided inside the exit end of the rear lens barrel. The third near-infrared multispectral biconvex lens is axially and circumferentially engaged with the fifth positioning step, and the near-infrared multispectral cemented concave-convex lens is circumferentially engaged with the sixth positioning step. The fifth positioning step provides axial and circumferential positioning for the third near-infrared multispectral biconvex lens, ensuring stable installation of the third near-infrared multispectral biconvex lens inside the rear lens barrel; the sixth positioning step provides axial and circumferential positioning for the near-infrared multispectral cemented concave-convex lens, ensuring stable installation of the near-infrared multispectral cemented concave-convex lens inside the rear lens barrel.

[0020] To better realize the present invention, further, a third threaded retaining ring is provided on the side of the third near-infrared multispectral biconvex lens away from the fifth positioning step, which axially presses the third near-infrared multispectral biconvex lens toward the fifth positioning step; a fourth threaded retaining ring is provided on the side of the near-infrared multispectral cemented concave-convex lens away from the sixth positioning step, which axially presses the near-infrared multispectral cemented concave-convex lens toward the sixth positioning step; both the inner walls of the third and fourth threaded retaining rings are provided with near-infrared multispectral retaining ring grating structures; the near-infrared multispectral retaining ring grating structure includes a light-blocking flange provided on the inner wall of the third or fourth threaded retaining ring and an inclined surface that transitions to and connects with the light-blocking flange.

[0021] The third near-infrared multispectral biconvex lens is axially pressed towards the fifth positioning step by the third threaded retaining ring. This, combined with the axial positioning of the third near-infrared multispectral biconvex lens by the fifth positioning step, achieves axial fixation of the lens. Simultaneously, the axial pressing force of the third threaded retaining ring restricts the circumferential movement of the third near-infrared multispectral biconvex lens, ensuring a tight and stable installation within the rear lens barrel. Similarly, the near-infrared multispectral cemented concave-convex lens is axially pressed towards the sixth positioning step by the fourth threaded retaining ring. This, combined with the axial positioning of the near-infrared multispectral cemented concave-convex lens by the sixth positioning step, achieves axial fixation of the near-infrared multispectral cemented concave-convex lens. Simultaneously, the axial pressing force of the fourth threaded retaining ring restricts the circumferential movement of the near-infrared multispectral cemented concave-convex lens, ensuring a tight and stable installation within the rear lens barrel. The near-infrared multispectral pressure ring grating structure on the inner wall of the third or fourth threaded pressure ring can block stray light, thereby reducing the adverse effects of stray light on the final imaging quality.

[0022] To better realize the present invention, the filter assembly further includes a filter base, and an adjustable filter or a switchable filter assembly is detachably disposed inside the filter base. The adjustable filter is used for automatic filtering, and the switchable filter assembly is used for manual filtering.

[0023] To better realize the present invention, the switching filter assembly further includes a switching cylinder detachably mounted on the filter base. The incident end of the switching cylinder is coaxially and detachably connected to the exit end of the front lens assembly, and the exit end of the switching cylinder is coaxially and detachably connected to the incident end of the rear lens assembly. A filter unit is detachably mounted inside the switching cylinder. The filter unit includes at least one bandpass filter and at least one flat lens coaxially mounted with the bandpass filter.

[0024] To better realize the present invention, the near-infrared light field imaging camera further includes a near-infrared light field incident lens group and a near-infrared light field exit lens group disposed inside the lens barrel along the optical path direction. A near-infrared light field intermediate lens group is disposed inside the lens barrel between the incident end and the exit end. A polarization device is detachably disposed between the incident end of the near-infrared light field intermediate lens group and the exit end of the near-infrared light field incident lens group. At least one grating structure for blocking stray light is disposed inside the lens barrel along the optical path direction. The exit end of the lens barrel is connected to the near-infrared light field imaging device through a focusing part. The focusing part is used to drive the exit end of the lens barrel to move axially relative to the incident end of the near-infrared light field imaging device to adjust the imaging focal length.

[0025] The exit end of the lens barrel is modularly connected to the imaging device via a focusing unit. The lens barrel, focusing unit, and imaging device can be replaced according to actual imaging needs. Simultaneously, the focusing unit allows for axial adjustment of the distance between the lens barrel and the imaging device, thus enabling flexible adjustment of the imaging focal length. Inside the lens barrel, along the optical path, are sequentially arranged a near-infrared light field incident lens group, a polarizing device, a near-infrared light field intermediate lens group, and a near-infrared light field exit lens group. The near-infrared light field incident lens group focuses the effective light reflected from the object into the lens barrel, making the reflected light more concentrated. The light then passes through the polarizing device, which polarizes the light. The polarized light then passes through the near-infrared light field intermediate lens group and the near-infrared light field exit lens group. These lenses adjust the optical path of the light entering the lens barrel, allowing the light exiting the lens barrel to be more concentrated and projected onto the target surface of the imaging device, thereby improving the final imaging effect. Meanwhile, in order to avoid the influence of stray light on the final imaging effect, at least one grating structure is set inside the lens barrel. The diameter of the optical path channel of the grating structure is set at the outermost edge of the effective light, which can not only ensure that the effective light passes through smoothly, but also block stray light, thereby avoiding the influence of stray light on the imaging effect.

[0026] To better realize the present invention, the polarization device further includes a polarization frame and a polarizer. The polarization frame is detachably installed between the incident end of the near-infrared light field intermediate lens group and the exit end of the near-infrared light field incident lens group. A polarization mounting step hole is provided on the polarization frame corresponding to the optical path, and a polarizer is installed inside the polarization mounting step hole. A glue injection groove is provided on the hole wall of the polarization mounting step hole corresponding to the edge of the polarizer.

[0027] To better realize the present invention, the near-infrared light field incident lens group further includes a first near-infrared light field incident concave-convex lens and a second near-infrared light field incident concave-convex lens arranged sequentially along the optical path. A plurality of fixing devices for pressing the first near-infrared light field incident concave-convex lens are arranged circumferentially on the wall of the incident end of the lens tube. A near-infrared light field incident positioning step is provided on one side of the second near-infrared light field incident concave-convex lens, and a near-infrared light field incident pressure ring is provided on the other side of the second near-infrared light field incident concave-convex lens to axially press the second near-infrared light field incident concave-convex lens toward the near-infrared light field incident positioning step. A near-infrared light field incident grating structure is provided on the inner wall of the near-infrared light field incident pressure ring.

[0028] To better realize the present invention, the near-infrared light field incident grating structure further includes an exit flange, which is disposed at the exit end of the inner hole wall of the near-infrared light field incident pressure ring. The incident end of the inner hole wall of the near-infrared light field incident pressure ring is transitionally connected to the exit flange through an inclined surface that is inclined toward the central axis of the lens barrel.

[0029] To better realize the present invention, the near-infrared light field intermediate lens group further includes a near-infrared light field intermediate concave-convex lens. A near-infrared light field intermediate positioning step is provided inside the lens barrel between the incident end and the exit end. The near-infrared light field intermediate concave-convex lens is axially and circumferentially limited and connected to the near-infrared light field intermediate positioning step. A near-infrared light field intermediate pressure ring is coaxially provided on one side of the near-infrared light field intermediate concave-convex lens, which axially presses the near-infrared light field intermediate concave-convex lens toward the near-infrared light field intermediate positioning step. A near-infrared light field intermediate grating structure is provided on the inner wall of the near-infrared light field intermediate pressure ring.

[0030] To better realize the present invention, the near-infrared light field intermediate grating structure further includes an incident flange, which is disposed at the incident end of the inner hole wall of the near-infrared light field intermediate pressure ring, and the exit end of the inner hole wall of the near-infrared light field intermediate pressure ring is transitionally connected to the incident flange through an inclined surface that is inclined toward the central axis of the lens barrel.

[0031] To better realize the present invention, the near-infrared light field emission lens group further includes a near-infrared light field cemented convex lens. The interior of the emission end of the lens tube is provided with a near-infrared light field emission positioning step. The near-infrared light field cemented convex lens is axially and circumferentially limited and connected to the near-infrared light field emission positioning step. A near-infrared light field emission pressure ring is provided on one side of the near-infrared light field cemented convex lens to axially press the near-infrared light field cemented convex lens toward the near-infrared light field emission positioning step. A near-infrared light field emission grating structure is provided on the inner wall of the near-infrared light field emission pressure ring.

[0032] To better realize the present invention, the near-infrared light field emission grating structure further includes an incident flange, which is disposed at the incident end of the inner hole wall of the near-infrared light field emission pressure ring, and the emission end of the inner hole wall of the near-infrared light field emission pressure ring is transitionally connected to the incident flange through an inclined surface that is inclined toward the central axis of the lens barrel.

[0033] To better realize the present invention, the visible light imaging camera further includes a visible light incident lens group and a visible light exiting lens group arranged sequentially at the incident end of the lens barrel along the optical path. A visible light intermediate lens group is arranged inside the lens barrel between the visible light incident lens group and the visible light exiting lens group. At least one grating structure for blocking stray light is arranged between the visible light incident lens group and the visible light intermediate lens group, and between the visible light intermediate lens group and the visible light exiting lens group. A visible light imaging device is connected to the exit end of the lens barrel through a focusing part, and the focusing part is used to drive the visible light imaging device to move axially relative to the exit end of the lens barrel.

[0034] The exit end of the lens barrel is modularly connected to the visible light imaging device via a focusing unit. The lens barrel, focusing unit, and visible light imaging device can be replaced according to actual imaging needs. Simultaneously, the focusing unit allows for axial adjustment of the distance between the lens barrel and the visible light imaging device, thus enabling flexible adjustment of the imaging focal length. Inside the lens barrel, along the optical path, are arranged a visible light incident lens group, a visible light intermediate lens group, and a visible light exit lens group. The visible light incident lens group focuses the effective light reflected from the object into the lens barrel, making the reflected light more concentrated. The visible light intermediate lens group and the visible light exit lens group adjust the optical path of the light entering the lens barrel, ensuring that the light exiting the lens barrel is more concentrated and projected onto the target surface of the visible light imaging device, thereby improving the final imaging effect. Furthermore, to avoid the influence of stray light on the final imaging effect, at least one grating structure is installed inside the lens barrel. The diameter of the optical path channel of the grating structure is positioned at the outermost edge of the effective light path, ensuring the smooth passage of effective light while blocking stray light, thus preventing stray light from affecting the imaging effect.

[0035] To better realize the present invention, a visible light blocking ring is further provided between the exit end of the visible light incident lens group and the incident end of the visible light intermediate lens group, and a visible light blocking ring grating structure is provided on the inner wall of the visible light blocking ring; a visible light intermediate pressure ring is provided between the exit end of the visible light intermediate lens group and the incident end of the visible light exiting lens group, and a visible light intermediate pressure ring grating structure is provided on the inner wall of the visible light intermediate pressure ring; a visible light incident pressure ring is provided inside the incident end of the lens barrel to axially press the visible light incident lens group toward the visible light intermediate lens group, and a visible light incident pressure ring grating structure is provided on the inner wall of the visible light incident pressure ring.

[0036] To better realize the present invention, the visible light blocking ring grating structure further includes an incident flange and an exit flange. The incident flange is disposed at the incident end of the inner hole wall of the visible light blocking ring, and the exit flange is disposed at the exit end of the inner hole wall of the visible light blocking ring. The inner hole wall of the visible light blocking ring is provided with a recessed portion in the direction of being recessed away from the central axis of the lens barrel at a position between the incident flange and the exit flange.

[0037] To better realize the present invention, the visible light intermediate pressure ring grating structure further includes an exit flange, which is disposed at the exit end of the inner hole wall of the visible light intermediate pressure ring, and the incident end of the inner hole wall of the visible light intermediate pressure ring is transitionally connected to the exit flange through an inclined surface that is inclined toward the central axis of the lens barrel.

[0038] To better realize the present invention, the visible light incident pressure ring grating structure further includes an exit flange, which is disposed at the exit end of the inner hole wall of the visible light incident pressure ring, and the incident end of the inner hole wall of the visible light incident pressure ring is connected to the exit flange by a slope inclined towards the central axis of the lens barrel.

[0039] To better realize the present invention, the visible light incident lens group further includes a visible light incident biconvex lens and a visible light incident plane mirror arranged along the optical path; a visible light incident positioning step is provided inside the incident end of the lens tube, the visible light incident plane mirror is axially and circumferentially positioned and engaged with the visible light incident positioning step, and a visible light incident spacer is provided between the incident end of the visible light incident plane mirror and the exit end of the visible light incident biconvex lens.

[0040] To better realize the present invention, the visible light intermediate lens group further includes a visible light intermediate concave-convex lens and a visible light intermediate concave lens arranged sequentially along the optical path. A visible light intermediate positioning step is provided inside the lens barrel between the incident end and the exit end. The visible light intermediate concave lens is axially and circumferentially positioned and engaged with the visible light intermediate positioning step. A visible light intermediate gasket is provided between the visible light intermediate concave lens and the visible light intermediate concave-convex lens.

[0041] To better realize the present invention, the visible light emitting lens group further includes a first visible light emitting concave-convex lens and a second visible light emitting concave-convex lens arranged sequentially along the optical path. A visible light emitting positioning step is provided inside the lens barrel at the emitting end. The second visible light emitting concave-convex lens is axially and circumferentially positioned and engaged with the visible light emitting positioning step. A visible light separator is coaxially arranged between the first and second visible light emitting concave-convex lenses. At least one visible light separator grating structure is provided on the inner wall of the visible light separator.

[0042] To better realize the present invention, the visible light grating structure further includes a grating step or a grating inclined surface inclined toward the central axis of the lens tube, which are disposed on the inner wall of the visible light grating.

[0043] To better realize the present invention, the infrared imaging camera further includes an infrared imaging device, an incident end of the infrared imaging device is equipped with a focusing unit, an exit end of the focusing unit is coaxially connected to the incident end of the infrared imaging device, and a lens assembly is mounted on the incident end of the focusing unit relative to the axial direction; at least one set of infrared incident lenses is mounted on the incident end of the lens assembly, at least one set of infrared exit lenses is mounted on the exit end of the lens assembly, and at least one set of grating structures is provided between the infrared incident lens group and the infrared exit lens group.

[0044] The light reflected from the object passes through an infrared incident lens group to adjust its optical path, then through an infrared exit lens group. After further adjustment by the infrared exit lens group, the light converges onto the detection surface of the infrared imaging device. The focusing connector allows for axial adjustment of the distance between the lens assembly and the infrared imaging device, thereby adjusting the imaging focal length and achieving a clear image. Simultaneously, as the light passes through the interior of the lens assembly, at least one stage of filter grating structure between the infrared incident and exit lens groups blocks stray light, thus reducing its impact on the final image quality.

[0045] To better realize the present invention, the lens assembly further includes a lens barrel, wherein an infrared incident end positioning step and an infrared incident end threaded retaining ring are coaxially arranged inside the incident end of the lens barrel, and an infrared incident lens group is coaxially arranged between the infrared incident end positioning step and the infrared incident end threaded retaining ring, with the infrared incident end threaded retaining ring pressing against the infrared incident lens group in a direction close to the infrared incident end positioning step; the exit end of the lens barrel is coaxially arranged with an infrared exit end positioning step and an infrared exit end threaded retaining ring, and an infrared exit lens group is coaxially arranged between the infrared exit end positioning step and the infrared exit end threaded retaining ring, with the infrared exit end threaded retaining ring pressing against the infrared exit lens group in a direction close to the infrared exit end positioning step.

[0046] To better realize the present invention, the infrared multi-level grating structure further includes several stepped holes coaxially disposed on the inner wall of the threaded pressure ring at the infrared incident end or the threaded pressure ring at the infrared emitting end, and the diameter of the stepped holes decreases sequentially along the optical path direction.

[0047] To better realize the present invention, the infrared incident lens group further includes an infrared incident concave-convex lens, wherein the curvature of the incident convex surface and the exit concave surface of the infrared incident concave-convex lens are different; the infrared exit lens group includes an infrared exit concave-convex lens and an infrared exit biconvex lens, wherein the infrared exit concave-convex lens is coaxially disposed between the infrared exit biconvex lens and the infrared incident lens group, wherein the curvature of the incident convex surface and the exit concave surface of the infrared exit concave-convex lens are different, and the curvature of the incident convex surface and the exit convex surface of the infrared exit biconvex lens are different.

[0048] To better realize the present invention, an infrared spacer is further provided coaxially between the infrared emitting concave-convex lens and the infrared emitting biconvex lens. One end of the infrared spacer is pressed against the infrared emitting concave-convex lens in the direction close to the threaded pressure ring of the infrared emitting end, and the other end of the infrared spacer is pressed against the infrared emitting biconvex lens in the direction close to the positioning step of the infrared emitting end. At least one infrared grating inclined surface inclined towards the central axis of the lens barrel is provided on the inner wall of the infrared spacer.

[0049] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0050] This invention constructs a four-channel polarization imaging system by coupling a near-infrared multispectral imaging camera, a near-infrared light field imaging camera, a visible light imaging camera, and an infrared imaging camera. This system can collect and image light of different wavelengths, intensities, and polarization states, and obtain corresponding images for light of different properties, enabling more comprehensive and multi-dimensional imaging and detection of objects. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the structure of a four-channel polarization imaging system;

[0052] Figure 2 This is a schematic diagram of the internal structure of a near-infrared multispectral imaging camera.

[0053] Figure 3 This is a schematic diagram of the three-dimensional structure of a near-infrared multispectral imaging camera;

[0054] Figure 4 This is a schematic diagram of the internal structure of the front camera assembly.

[0055] Figure 5 for Figure 4 A magnified view of a portion at point E;

[0056] Figure 6 for Figure 4 A magnified view of a portion at point F;

[0057] Figure 7 This is a schematic diagram of the internal structure of the rear camera assembly.

[0058] Figure 8 for Figure 7 A magnified view of a portion of point G;

[0059] Figure 9 for Figure 7 Enlarged view of a portion at point H;

[0060] Figure 10 This is a schematic diagram of the installation of the switching filter assembly;

[0061] Figure 11 This is a schematic diagram of the structure of the switching filter assembly;

[0062] Figure 12 This is a schematic diagram of the installation of a bandpass filter;

[0063] Figure 13 This is a schematic diagram of the switching cylinder.

[0064] Figure 14 This is a schematic diagram of the internal structure of a near-infrared light field imaging camera.

[0065] Figure 15 This is a schematic diagram of the polarizer installation.

[0066] Figure 16 This is a schematic diagram of the polarization frame structure;

[0067] Figure 17 This is a schematic diagram of the near-infrared light field incident lens group;

[0068] Figure 18 for Figure 17 A magnified view of a portion of point I;

[0069] Figure 19 This is a schematic diagram of the structure of the intermediate lens group in the near-infrared light field;

[0070] Figure 20 for Figure 19 A magnified view of a portion of point J;

[0071] Figure 21 This is a schematic diagram of the near-infrared light field output lens group;

[0072] Figure 22 for Figure 21 A magnified view of a portion at point K;

[0073] Figure 23 This is a schematic diagram of the internal structure of the lens barrel of a near-infrared light field imaging camera.

[0074] Figure 24 This is a schematic diagram of the internal structure of a visible light imaging camera;

[0075] Figure 25 This is a schematic diagram of the visible light blocking ring.

[0076] Figure 26 for Figure 25 A magnified view of a portion at point L;

[0077] Figure 27 This is a schematic diagram of the visible light intermediate pressure ring structure;

[0078] Figure 28 for Figure 27 A magnified view of a portion at point M;

[0079] Figure 29 This is a schematic diagram of the visible light incident pressure ring.

[0080] Figure 30 for Figure 29 A magnified view of N local points;

[0081] Figure 31 This is a schematic diagram of the visible light incident lens group;

[0082] Figure 32 This is a schematic diagram of the visible light intermediate lens group;

[0083] Figure 33 This is a schematic diagram of the visible light output lens group;

[0084] Figure 34 This is a schematic diagram of the internal structure of the lens barrel of a visible light imaging camera;

[0085] Figure 35 This is a schematic diagram of the internal structure of an infrared imaging camera.

[0086] Figure 36 This is a schematic diagram of the infrared incident lens group;

[0087] Figure 37 for Figure 36 A magnified view of a portion of point O;

[0088] Figure 38 This is a schematic diagram of the infrared output lens group;

[0089] Figure 39 for Figure 38 A magnified view of a portion of point P;

[0090] Figure 40 for Figure 38 A magnified view of part Q.

[0091] Wherein: A - Near-infrared multispectral imaging camera; B - Near-infrared light field imaging camera; C - Visible light imaging camera; D - Infrared imaging camera; A1 - Front lens assembly; A2 - Filter assembly; A3 - Rear lens assembly; A4 - Near-infrared multispectral imaging device; A11 - Convex lens group; A12 - Concave lens group; A13 - First threaded retaining ring; A14 - Second threaded retaining ring; A15 - Third threaded retaining ring; A16 - Fourth threaded retaining ring; A21 - Adjustable filter; A22 - Switchable filter assembly; A3 1-Rear convex lens group; A32-Rear concave-convex lens group; A100-Near-infrared multispectral pressure ring grating structure; A111-First near-infrared multispectral biconvex lens; A112-Second near-infrared multispectral biconvex lens; A121-First near-infrared multispectral biconcave lens; A122-Second near-infrared multispectral biconcave lens; A221-Switching cylinder; A222-Bandpass filter; A223-Plate lens; A311-Third near-infrared multispectral biconvex lens; A321-Near-infrared multispectral cemented concave-convex lens;

[0092] B1 - Near-infrared light field incident lens; B2 - Near-infrared light field intermediate lens group; B3 - Near-infrared light field exit lens group; B4 - Polarization device; B5 - Near-infrared light field imaging device; B11 - First near-infrared light field incident concave-convex lens; B12 - Second near-infrared light field incident concave-convex lens; B13 - Fixing device; B14 - Near-infrared light field incident positioning step; B21 - Near-infrared light field intermediate concave-convex lens; B22 - Near-infrared light field intermediate positioning stage Step; B23 - Near-infrared light field intermediate pressure ring; B31 - Near-infrared light field cemented convex lens; B32 - Near-infrared light field emission positioning step; B33 - Near-infrared light field emission pressure ring; B41 - Polarizing frame; B42 - Polarizing sheet; B43 - Polarizing mounting step hole; B44 - Glue injection groove; B45 - Near-infrared light field incident pressure ring; B231 - Near-infrared light field intermediate grating structure; B331 - Near-infrared light field emission grating structure; B451 - Near-infrared light... Field incidence grating structure: C1 - Visible light incident lens group; C2 - Visible light intermediate lens; C3 - Visible light exit lens group; C4 - Visible light imaging device; C5 - Visible light blocking ring; C6 - Visible light intermediate pressure ring; C7 - Visible light incident pressure ring; C11 - Visible light incident biconvex lens; C12 - Visible light incident plane mirror; C13 - Visible light incident positioning step; C14 - Visible light incident spacer; C21 - Visible light intermediate concave-convex lens; C2 2-Visible light intermediate concave lens; C23-Visible light intermediate positioning step; C24-Visible light intermediate spacer; C31-First visible light exiting concave-convex lens; C32-Second visible light exiting concave-convex lens; C33-Visible light exiting positioning step; C34-Visible light septum; C51-Visible light blocking ring grating structure; C61-Visible light intermediate pressure ring grating structure; C71-Visible light incident pressure ring grating structure; C341-Visible light septum grating structure;

[0093] D1 - Infrared incident lens group; D2 - Infrared exit lens group; D3 - Infrared imaging device; D4 - Infrared incident end positioning step; D5 - Infrared incident end threaded pressure ring; D6 - Infrared exit end positioning step; D7 - Infrared exit end threaded pressure ring; D11 - Infrared incident concave-convex lens; D21 - Infrared exit concave-convex lens; D22 - Infrared exit biconvex lens; D23 - Infrared septum; D100 - Infrared multi-level grating structure; D200 - Infrared grating inclined surface. Detailed Implementation

[0094] Example 1:

[0095] This embodiment provides a four-channel polarization imaging system, such as... Figure 1 As shown, the encapsulated housing contains four acquisition channels, each housing a near-infrared multispectral imaging camera A, a near-infrared light field imaging camera B, a visible light imaging camera C, and an infrared imaging camera D for multi-dimensional imaging detection of objects. Near-infrared multispectral imaging camera A has an adjustable filter that transmits light of a selected wavelength for imaging. Near-infrared light field imaging camera B has a polarization device that polarizes light for imaging. Visible light imaging camera C is used to acquire and image light within the visible wavelength range. Infrared imaging camera D is used to acquire and image light within the infrared wavelength range.

[0096] The four-channel polarization imaging system mainly consists of four parts: near-infrared multispectral imaging camera A, near-infrared light field imaging camera B, visible light imaging camera C, and infrared imaging camera D. These four cameras are independent of each other but are combined together through encapsulated structural components, enabling multi-dimensional detection of targets.

[0097] Example 2:

[0098] This embodiment is a further optimization based on Embodiment 1 described above, such as... Figures 2-13 As shown, the near-infrared multispectral imaging camera A includes a front lens assembly A1, a filter assembly A2, a rear lens assembly A3, and a near-infrared multispectral imaging device A4, which are coaxially arranged inside the lens barrel. The front lens assembly A1 is used to adjust the light transmission to an angle of less than or equal to 1° with the axis. The filter assembly A2 is used to automatically selectively transmit light within a specific wavelength range. The rear lens assembly A3 is used to adjust the light transmission to be within the effective imaging light range of the near-infrared multispectral imaging device A4. The near-infrared multispectral imaging device A4 is axially movable and mounted to the exit end of the rear lens assembly A3 through a focusing part to achieve axial movement focusing imaging of the near-infrared multispectral imaging device A4 itself. At least one grating structure for blocking stray light is arranged inside the lens barrel along the optical path.

[0099] The front lens assembly A1, filter assembly A2, rear lens assembly A3, and near-infrared multispectral imaging device A4 are all equipped with light channels for light to pass through, and these light channels are coaxially arranged. Both the front lens assembly A1 and the rear lens assembly A3 are used to adjust the light path. The front lens assembly A1 adjusts the angle between the light and the axis to less than or equal to 16°, and the rear lens assembly A3 adjusts the angle to less than or equal to 1°, thus ensuring that the converged light rays are incident on the imaging surface of the near-infrared multispectral imaging device A4 in a direction nearly parallel to the axis, thereby achieving high-brightness and clear imaging. A filter assembly A2 is located between the front lens assembly A1 and the rear lens assembly A3. The filter assembly A2 allows light within a specific wavelength range to pass through, while light outside this range is filtered out. The filter assembly A2 can automatically or manually adjust its filtering parameters according to filtering requirements, enabling faster and more stable filtering operations. Meanwhile, the near-infrared multispectral imaging device A4 is rear-mounted at the emission end of the rear lens assembly A3, and the near-infrared multispectral imaging device A4 itself can move axially closer to or further away from the rear lens assembly A3, thereby adjusting the focal length and ultimately forming a clear image on the imaging surface of the near-infrared multispectral imaging device A4. The front lens assembly A1, filter assembly A2, rear lens assembly A3, and near-infrared multispectral imaging device A4 are combined in segments to form the camera structure. The length and volume of the front lens assembly A1, filter assembly A2, rear lens assembly A3, and near-infrared multispectral imaging device A4 can be flexibly adjusted according to different actual imaging needs, effectively reducing the overall size of the camera.

[0100] The other parts of this embodiment are the same as those in Embodiment 1, so they will not be described again.

[0101] Example 3:

[0102] This embodiment is a further optimization based on the above embodiment 1 or 2. The incident end of the filter assembly A2 is provided with a light hole and a threaded hole coaxially along the optical axis. The light hole is connected to the output end shaft hole of the front lens assembly A1, and the threaded hole is connected to the output end of the front lens assembly A1 by a thread. The output end of the filter assembly A2 is provided with a light hole, which is connected to the incident end shaft hole of the rear lens assembly A3.

[0103] The optical aperture at the incident end of the filter assembly A2 is fitted with the optical axis at the exit end of the front lens assembly A1 to ensure coaxiality between the adjustable filter assembly A2 and the front lens assembly A1. The threaded hole at the incident end of the filter assembly A2 is threadedly fitted with the threaded portion at the exit end of the front lens assembly A1 to achieve a tight and stable connection between the adjustable filter assembly A2 and the front lens assembly A1.

[0104] The light aperture at the exit end of the filter assembly A2 is connected to the shaft hole at the entrance end of the rear lens assembly A3 to ensure the coaxiality between the filter assembly A2 and the rear lens assembly A3. At the same time, the end face of the exit end of the filter assembly A2 and the end face of the entrance end of the rear lens assembly A3 are securely connected by connecting bolts.

[0105] The other parts of this embodiment are the same as those in Embodiment 1 or 2, so they will not be described again.

[0106] Example 4:

[0107] This embodiment is a further optimization based on any one of embodiments 1-3 above. The front lens assembly A1 includes a front lens barrel, a convex lens group A11, and a concave lens group A12. The incident end of the front lens barrel is provided with the convex lens group A11, which includes a first near-infrared multispectral biconvex lens A111 and a second near-infrared multispectral biconvex lens A112 coaxially disposed at the incident end of the front lens barrel. A first positioning step is provided inside the incident end of the front lens barrel, and a second positioning step is provided inside the exit end of the front lens barrel. The first near-infrared multispectral biconvex lens A111 and the first positioning step are... The second near-infrared multispectral biconvex lens A112 is axially and circumferentially engaged with the second positioning step; the front concave lens group A12 includes a first near-infrared multispectral biconvex lens A121 and a second near-infrared multispectral biconvex lens A122 coaxially disposed at the exit end of the front lens barrel, and a third positioning step and a fourth positioning step are disposed inside the exit end of the front lens barrel, the first near-infrared multispectral biconvex lens A121 is axially and circumferentially engaged with the third positioning step, and the second near-infrared multispectral biconvex lens A122 is axially and circumferentially engaged with the fourth positioning step.

[0108] The front lens barrel has a threaded part 111 and an optical axis part 112 coaxially arranged at the exit end. The threaded part 111 is threadedly connected to the threaded hole at the entrance end of the filter assembly A2. The optical axis part 112 is axially connected to the optical hole at the entrance end of the filter assembly A2. This ensures a tight and stable connection between the front lens barrel and the filter assembly A2, while also ensuring the coaxiality of the light path on the front lens barrel and the filter assembly A2.

[0109] The axial end face of the first positioning step engages with the axial end face of the first near-infrared multispectral biconvex lens A111, achieving axial positioning of the first near-infrared multispectral biconvex lens A111. Simultaneously, the circumferential step surface of the first positioning step engages with the circumferential surface of the first near-infrared multispectral biconvex lens A111, achieving circumferential positioning of the first near-infrared multispectral biconvex lens A111, ensuring stable installation of the first near-infrared multispectral biconvex lens A111 inside the front lens barrel. Similarly, the axial end face of the second positioning step engages with the axial end face of the second near-infrared multispectral biconvex lens A112, achieving axial positioning of the second near-infrared multispectral biconvex lens A112. Simultaneously, the circumferential step surface of the second positioning step engages with the circumferential surface of the second near-infrared multispectral biconvex lens A112, achieving circumferential positioning of the second near-infrared multispectral biconvex lens A112, ensuring stable installation of the second near-infrared multispectral biconvex lens A112 inside the front lens barrel.

[0110] The axial end face of the third positioning step engages with the axial end face of the first near-infrared multispectral biconcave lens A121, achieving axial positioning of the first near-infrared multispectral biconcave lens A121. Simultaneously, the circumferential step surface of the third positioning step engages with the circumferential surface of the first near-infrared multispectral biconcave lens A121, achieving circumferential positioning of the first near-infrared multispectral biconcave lens A121, ensuring its stable installation inside the front lens barrel. Similarly, the axial end face of the fourth positioning step engages with the axial end face of the second near-infrared multispectral biconcave lens A122, achieving axial positioning of the second near-infrared multispectral biconcave lens A122. Simultaneously, the circumferential step surface of the fourth positioning step engages with the circumferential surface of the second near-infrared multispectral biconcave lens A122, achieving circumferential positioning of the second near-infrared multispectral biconcave lens A122, ensuring its stable installation inside the front lens barrel.

[0111] The other parts of this embodiment are the same as any one of embodiments 1-3, so they will not be described again.

[0112] Example 5:

[0113] The embodiment is a further optimization based on any one of the embodiments 1-4 above. A first threaded retaining ring A13 is provided on the side of the first near-infrared multispectral biconvex lens A111 away from the first positioning step to press the first near-infrared multispectral biconvex lens A111 toward the first positioning step. A second threaded retaining ring A14 is provided on the side of the second near-infrared multispectral biconvex lens A112 away from the second positioning step to press the second near-infrared multispectral biconvex lens A112 toward the second positioning step. Near-infrared multispectral retaining ring grating structures A100 are provided on the inner walls of the first threaded retaining ring A13 and the second threaded retaining ring A14. The near-infrared multispectral retaining ring grating structure A100 includes a light-blocking flange provided on the inner wall of the first threaded retaining ring A13 or the second threaded retaining ring A14 and an inclined surface that transitions to and connects with the light-blocking flange.

[0114] The front lens barrel has a first internal thread on one side of the first positioning step. A first threaded retaining ring A13 is threadedly engaged with the first internal thread. A first near-infrared multispectral biconvex lens A111 is coaxially positioned between the first threaded retaining ring A13 and the first positioning step. Rotating the first threaded retaining ring A13 moves it towards the first near-infrared multispectral biconvex lens A111, thereby pressing the first near-infrared multispectral biconvex lens A111 onto the first positioning step, thus achieving a secure clamping and fixing of the first near-infrared multispectral biconvex lens A111. Simultaneously, an axial relief groove is provided in the engagement section between the first threaded retaining ring A13 and the first internal thread to prevent the first threaded retaining ring A13 from failing to engage properly and effectively clamp the first near-infrared multispectral biconvex lens A111. After the first threaded retaining ring A13 is screwed into position to fully press the first near-infrared multispectral biconvex lens A111, glue is applied to the first threaded retaining ring A13 to effectively loosen it.

[0115] Similarly, a second internal thread is provided inside the front lens barrel on one side of the second positioning step. The second threaded retaining ring A14 is threadedly engaged with the second internal thread. The second near-infrared multispectral biconvex lens A112 is coaxially positioned between the second threaded retaining ring A14 and the second positioning step. By rotating the second threaded retaining ring A14, it can be moved towards the second near-infrared multispectral biconvex lens A112, thereby pressing the second near-infrared multispectral biconvex lens A112 onto the second positioning step, achieving the clamping and fixing of the second near-infrared multispectral biconvex lens A112. At the same time, an axial relief groove is provided in the screw-in section of the second threaded retaining ring A14 and the second internal thread to prevent the second threaded retaining ring A14 from failing to screw into place and effectively clamp the second near-infrared multispectral biconvex lens A112. After the second threaded retaining ring A14 is screwed into position to fully press the second near-infrared multispectral biconvex lens A112, glue is applied to the second threaded retaining ring A14 to effectively loosen it.

[0116] The other parts of this embodiment are the same as any one of embodiments 1-4, so they will not be described again.

[0117] Example 6:

[0118] This embodiment further optimizes any one of embodiments 1-5 described above. The rear lens assembly A3 includes a rear lens barrel, with a rear convex lens group A31 disposed inside the incident end of the rear lens barrel and a rear concave-convex lens group A32 disposed inside the exit end of the rear lens barrel. The rear convex lens group A31 includes a third near-infrared multispectral biconvex lens A311 disposed at the incident end of the rear lens barrel, and the rear concave-convex lens group A32 includes a near-infrared multispectral cemented concave-convex lens A321 disposed at the exit end of the rear lens barrel. The exit end of the rear lens barrel is connected to the incident end of the near-infrared multispectral imaging device A4 through a focusing part, which is used to drive the near-infrared multispectral imaging device A4 to move axially closer to or further away from the exit end of the rear lens barrel. The other parts of this embodiment are the same as any one of embodiments 1-5, and therefore will not be described again.

[0119] Example 7:

[0120] This embodiment is a further optimization based on any one of the above embodiments 1-6. A fifth positioning step is provided inside the incident end of the rear lens barrel, and a sixth positioning step is provided inside the exit end of the rear lens barrel. The third near-infrared multispectral biconvex lens A311 is axially and circumferentially engaged with the fifth positioning step, and the near-infrared multispectral cemented concave-convex lens A321 is circumferentially and circumferentially engaged with the sixth positioning step.

[0121] The axial end face of the fifth positioning step engages with the axial end face of the third near-infrared multispectral biconvex lens A311, achieving axial positioning of the third near-infrared multispectral biconvex lens A311. Simultaneously, the circumferential step surface of the fifth positioning step engages with the outer circular surface of the third near-infrared multispectral biconvex lens A311, achieving circumferential positioning of the third near-infrared multispectral biconvex lens A311, ensuring its stable installation inside the rear lens barrel. Similarly, the axial end face of the sixth positioning step engages with the axial end face of the near-infrared multispectral cemented concave-convex lens A321, achieving axial positioning of the near-infrared multispectral cemented concave-convex lens A321. At the same time, the circumferential step surface of the sixth positioning step engages with the outer circular surface of the near-infrared multispectral cemented concave-convex lens A321, thereby achieving circumferential positioning of the near-infrared multispectral cemented concave-convex lens A321 and ensuring that the near-infrared multispectral cemented concave-convex lens A321 is stably installed inside the rear lens barrel.

[0122] The other parts of this embodiment are the same as any one of embodiments 1-6, so they will not be described again.

[0123] Example 8:

[0124] This embodiment further optimizes any one of embodiments 1-7 above. A third threaded retaining ring A15 is provided on the side of the third near-infrared multispectral biconvex lens A311 away from the fifth positioning step, which axially presses the third near-infrared multispectral biconvex lens A311 toward the fifth positioning step; a fourth threaded retaining ring A16 is provided on the side of the near-infrared multispectral cemented concave-convex lens A321 away from the sixth positioning step, which axially presses the near-infrared multispectral cemented concave-convex lens A321 toward the sixth positioning step; a near-infrared multispectral retaining ring grating structure A100 is provided on the inner wall of both the third threaded retaining ring A15 and the fourth threaded retaining ring A16; the near-infrared multispectral retaining ring grating structure A100 includes a light-blocking flange provided on the inner wall of the third threaded retaining ring A15 or the fourth threaded retaining ring A16 and an inclined surface that transitions to and connects with the light-blocking flange.

[0125] The rear lens barrel has a third internal thread on one side of the fifth positioning step. The third threaded retaining ring A15 is threadedly engaged with the third internal thread. The three near-infrared multispectral biconvex lenses A311 are coaxially positioned between the third threaded retaining ring A15 and the fifth positioning step. Rotating the third threaded retaining ring A15 moves it towards the three near-infrared multispectral biconvex lenses A311, thus pressing the lenses onto the fifth positioning step and securing them in place. Simultaneously, an axial relief groove is provided in the engagement section between the third threaded retaining ring A15 and the third internal thread to prevent the retaining ring A15 from failing to engage properly and effectively press the lenses together. After the third threaded retaining ring A15 is screwed into position to fully press the three near-infrared multispectral biconvex lenses A311, glue is applied to the third threaded retaining ring A15 to effectively loosen it.

[0126] Similarly, a fourth internal thread is provided on one side of the sixth positioning step inside the rear lens barrel. The fourth threaded retaining ring A16 is threadedly engaged with the fourth internal thread. The near-infrared multispectral cemented concave-convex lens A321 is coaxially positioned between the fourth threaded retaining ring A16 and the sixth positioning step. By rotating the fourth threaded retaining ring A16, it can be moved towards the near-infrared multispectral cemented concave-convex lens A321, thereby pressing the near-infrared multispectral cemented concave-convex lens A321 onto the sixth positioning step, thus achieving the clamping and fixing of the near-infrared multispectral cemented concave-convex lens A321. At the same time, an axial relief groove is provided in the screw-in section of the fourth threaded retaining ring A16 and the fourth internal thread to prevent the fourth threaded retaining ring A16 from failing to screw in properly and effectively clamp the near-infrared multispectral cemented concave-convex lens A321. After the fourth threaded retaining ring A16 is screwed into position to fully press the near-infrared multispectral adhesive concave-convex lens A321, glue is applied to the fourth threaded retaining ring A16 to effectively loosen it.

[0127] The other parts of this embodiment are the same as any one of the embodiments 1-7 above, so they will not be described again.

[0128] Example 9:

[0129] This embodiment is a further optimization based on any one of the above embodiments 1-8. The filter assembly A2 includes a filter base, and an adjustable filter A21 or a switchable filter assembly A22 is detachably disposed inside the filter base. The adjustable filter A21 is used for automatic filtering, and the switchable filter assembly A22 is used for manual filtering.

[0130] The switching filter assembly A22 includes a switching cylinder A221 detachably mounted on the filter base. The incident end of the switching cylinder A221 is coaxially and detachably connected to the exit end of the front lens assembly A1, and the exit end of the switching cylinder A221 is coaxially and detachably connected to the incident end of the rear lens assembly A3. A filter unit is detachably mounted inside the switching cylinder A221. The filter unit includes at least one bandpass filter A222 and at least one flat lens A223 coaxially mounted with the bandpass filter A222.

[0131] The other parts of this embodiment are the same as any one of the embodiments 1-8 above, so they will not be described again.

[0132] Example 10:

[0133] This embodiment is a further optimization based on any one of the above embodiments 1-9. The near-infrared multispectral imaging device A4 includes a chip box A41 and an imaging chip A43. The incident end of the chip box A41 is coaxially movable relative to the exit end of the rear lens assembly A3. The imaging chip A43 is disposed inside the chip box A41.

[0134] Furthermore, the input end of the chip box A41 is connected to the output end shaft hole of the rear lens assembly A3.

[0135] Furthermore, a cover A42 is detachably provided at the end of the chip box A41 away from the rear lens assembly A3.

[0136] The other parts of this embodiment are the same as any one of the embodiments 1-9 above, so they will not be described again.

[0137] Example 11:

[0138] This embodiment is a further optimization based on any one of embodiments 1-10 above, such as... Figures 14-23 As shown, the near-infrared light field imaging camera B includes a near-infrared light field incident lens group B1 and a near-infrared light field exit lens group B3 disposed inside the lens barrel along the optical path direction. A near-infrared light field intermediate lens group B2 is disposed inside the lens barrel between the incident end and the exit end. A polarization device B4 is detachably disposed between the incident end of the near-infrared light field intermediate lens group B2 and the exit end of the near-infrared light field incident lens group B1. At least one grating structure for blocking stray light is disposed inside the lens barrel along the optical path direction. The exit end of the lens barrel is connected to the near-infrared light field imaging device B5 through a focusing part. The focusing part is used to drive the exit end of the lens barrel to move axially relative to the incident end of the near-infrared light field imaging device B5 to adjust the imaging focal length.

[0139] The lens barrel has an entrance mounting port at the incident end and an exit mounting port at the exit end. The near-infrared light field incident lens group B1 is installed into the entrance mounting port in the direction from the incident end to the exit end. The near-infrared light field intermediate lens group B2 is installed inside the lens barrel through the exit mounting port in the direction from the exit end to the incident end. The near-infrared light field exit lens group B3 is installed into the exit mounting port in the direction from the exit end to the incident end. A polarization device B4 is detachably inserted between the near-infrared light field incident lens group B1 and the near-infrared light field intermediate lens group B2 for polarizing the light.

[0140] The near-infrared light field incident lens group B1 is used to concentrate the effective light reflected from the object into the interior of the lens tube. The effective light is polarized by the polarization device B4 to obtain polarized light. The polarized light is then transmitted to the imaging target surface of the near-infrared light field imaging device B5 after the optical path is adjusted by the near-infrared light field intermediate lens group B2 and the near-infrared light field exit lens group B3. At the same time, the focusing unit can adjust the axial distance between the exit end of the lens tube and the near-infrared light field imaging device B5, thereby allowing for real-time flexible adjustment of the imaging focal length according to actual imaging requirements, to ensure a clear image on the imaging target surface of the near-infrared light field imaging device B5.

[0141] The other parts of this embodiment are the same as any one of the embodiments 1-10 above, so they will not be described again.

[0142] Example 12:

[0143] This embodiment is a further optimization based on any one of the above embodiments 1-11. The polarization device B4 includes a polarization frame B41 and a polarizer B42. The polarization frame B41 is detachably installed between the incident end of the near-infrared light field intermediate lens group B2 and the exit end of the near-infrared light field incident lens group B1. A polarization mounting step hole B43 is provided on the polarization frame B41 corresponding to the optical path. The polarizer B42 is installed inside the polarization mounting step hole B43. A glue injection groove B44 is provided on the hole wall of the polarization mounting step hole B43 corresponding to the edge of the polarizer B42.

[0144] Polarizer B42 includes at least four types: 0° polarizer, 45° polarizer, 90° polarizer, and circular polarizer. By polarizing and filtering light through polarizer B42, light with different polarization states can be obtained, thereby improving the contrast of object imaging, helping to distinguish blurred areas in object imaging, and thus facilitating the subsequent identification and precise tracking of pixel features in object imaging.

[0145] Further, the target surface of polarizer B42 needs to be arranged parallel to the imaging target surface of the near-infrared light field imaging device B5, the polarization frame 41 is provided with an insertion slot parallel to the imaging target surface of the near-infrared light field imaging device B5, and the polarizer B42 is directly inserted into the insertion slot to ensure the parallelism between the imaging target surface of the near-infrared light field imaging device B5 and the target surface of the polarizer B42.

[0146] The focusing part drives the near-infrared light field imaging device B5 to translate axially without driving the near-infrared light field imaging device B5 to rotate circumferentially, thereby ensuring that the polarizer B42 corresponds in parallel to the microlens units on the imaging target surface of the near-infrared light field imaging device B5, and avoiding wire缠绕 at the same time.

[0147] A slot for inserting the polarization frame B41 into the lens barrel is provided on the outer wall of the lens barrel in the area between the incident end and the exit end, connecting threaded holes are provided on both sides of the slot, connecting lugs are provided on both sides of the polarization frame B41, and connecting through holes corresponding to the connecting threaded holes are provided on the connecting lugs. A polarization mounting step hole B43 for clamping the polarizer B42 is provided on the polarization frame B41. The end surface of the polarizer B42 abuts in cooperation with the axial end surface of the polarization mounting step hole B43, and the side surface of the polarizer B42 is connected in cooperation with the hole wall of the polarization mounting step hole B43. After the polarization frame B41 is inserted into the lens barrel through the slot, connecting bolts can be screwed into the aligned connecting threaded holes and connecting through holes, so as to realize the fixed installation of the polarization frame B41 inside the lens barrel.

[0148] Further, the polarization mounting step hole B43 is divided into a plurality of polarization regions, a polarizer B42 is arranged inside each polarization region, and each polarizer B42 shall be arranged as close as possible to the center position of the polarization mounting step hole B43.

[0149] The polarization mounting step hole B43 is divided into four polarization regions arranged in a "field" shape, a polarizer B42 is arranged in each polarization region, and the polarizers B42 arranged in the four polarization regions are a 0° polarizer, a 45° polarizer, a 90° polarizer, and an RCP / LCP polarizer respectively. By arranging four polarizers B42 with different polarization angles, light of different polarization states can be tuned after light passes through the four polarizers B42, and finally light of different polarization states is fused by the light detector in the imaging device, thereby enhancing the contrast of object imaging, making object imaging clearer, and at the same time ensuring that the indistinguishable blurred regions on object imaging have stronger contrast, thereby effectively distinguishing and extracting different pixel features on the image when the object image is subsequently processed.

[0150] The vertical centerline of the end face of the polarizing mounting stepped hole B43 is taken as the Y-axis, and the horizontal centerline of the polarizing mounting stepped hole B43 is taken as the X-axis. The distance between the side of each polarizer B42 parallel to the Y-axis and close to the Y-axis and the Y-axis is 0.25mm, and the distance between the side of each polarizer B42 parallel to the X-axis and close to the X-axis and the X-axis is 0.25mm.

[0151] Furthermore, an adhesive injection groove B44 is provided on the wall of the polarization mounting step hole B43 corresponding to the edge of the polarizer B42. After the polarizer B42 is inserted into the polarization mounting step hole B43, adhesive is injected into the adhesive injection groove B44 to bond the edge of the polarizer B42 to the wall of the polarization mounting step hole B43, thereby achieving effective fixation of the polarizer B42.

[0152] Furthermore, the axial thickness and diameter of the polarization mounting step hole B43 need to be limited to reduce the space occupied by the polarization frame B41, thereby preventing the polarization frame B41 from affecting the final imaging quality.

[0153] The overall axial thickness of the polarization mounting stepped hole B43 is less than or equal to 2.8 mm, and the axial thickness of the step at the exit end of the polarization mounting stepped hole B43 is less than or equal to 0.4 mm. The polarization mounting stepped hole B43 is a square hole, and the side length of the polarization mounting stepped hole B43 is less than or equal to 14.6 mm.

[0154] The other parts of this embodiment are the same as any one of the embodiments 1-11 above, so they will not be described again.

[0155] Example 13:

[0156] This embodiment is a further optimization based on any one of the above embodiments 1-12. The near-infrared light field incident lens group B1 includes a first near-infrared light field incident concave-convex lens B11 and a second near-infrared light field incident concave-convex lens B12 arranged sequentially along the optical path. A plurality of fixing devices B13 are arranged circumferentially on the wall of the incident end of the lens barrel to press the first near-infrared light field incident concave-convex lens B11 tightly. A near-infrared light field incident positioning step B14 is provided on one side of the second near-infrared light field incident concave-convex lens B12, and a near-infrared light field incident pressure ring B45 is provided on the other side of the second near-infrared light field incident concave-convex lens B12 axially pressing the second near-infrared light field incident concave-convex lens B12 toward the near-infrared light field incident positioning step B14. A near-infrared light field incident grating structure B451 is provided on the inner wall of the near-infrared light field incident pressure ring B45.

[0157] The incident surface of the first near-infrared light field incident concave-convex lens B11 is convex, and the exit surface of the first near-infrared light field incident concave-convex lens B11 is concave, and the curvature of the incident surface of the first near-infrared light field incident concave-convex lens B11 is greater than or equal to the curvature of the exit surface of the first near-infrared light field incident concave-convex lens B11; the incident surface of the second near-infrared light field incident concave-convex lens B12 is convex, and the exit surface of the second near-infrared light field incident concave-convex lens B12 is concave, and the curvature of the incident surface of the second near-infrared light field incident concave-convex lens B12 is greater than or equal to the curvature of the exit surface of the second near-infrared light field incident concave-convex lens B12.

[0158] The incident end of the lens barrel has an internal incident thread, and the outer surface of the near-infrared light field incident pressure ring B4 has an external incident pressure ring thread that is threadedly connected to the internal incident thread. By screwing the internal incident thread and the external incident pressure ring thread together, the near-infrared light field incident pressure ring B4 can be installed into the lens barrel. At the same time, by rotating the near-infrared light field incident pressure ring B4, the near-infrared light field incident pressure ring B4 is axially pressed against the second near-infrared light field incident concave-convex lens B12, thereby achieving axial fixation of the second near-infrared light field incident concave-convex lens B12.

[0159] A near-infrared light field incident grating structure B451 is provided on the inner wall of the light-transmitting hole at the center of the near-infrared light field incident pressure ring B4. The aperture of the near-infrared light field incident grating structure B451 is set to correspond to the edge of the effective light passing through the light-transmitting hole. Thus, the near-infrared light field incident grating structure B451 can block stray light that exceeds the edge range of the effective light, thereby reducing the adverse effect of stray light on the final image quality.

[0160] The other parts of this embodiment are the same as any one of the embodiments 1-12 above, so they will not be described again.

[0161] Example 14:

[0162] This embodiment is a further optimization based on any one of the above embodiments 1-13. The near-infrared light field incident grating structure B451 includes an exit flange. The exit flange is disposed at the exit end of the inner hole wall of the near-infrared light field incident pressure ring B45. The incident end of the inner hole wall of the near-infrared light field incident pressure ring B45 is connected to the exit flange through a slope inclined towards the central axis of the lens barrel.

[0163] The near-infrared light field incident pressure ring B45 is located at the incident end of the second near-infrared light field incident concave-convex lens B12. Therefore, the exit flange is located at the exit end of the inner wall of the near-infrared light field incident pressure ring B45. Furthermore, since the first near-infrared light field incident concave-convex lens B11 converges the light rays, the inclined surface is inclined with the diameter of the inclined incident end being larger than the diameter of the inclined exit end, and the inclined exit end and the exit flange are smoothly connected.

[0164] The other parts of this embodiment are the same as any one of the embodiments 1-13 above, so they will not be described again.

[0165] Example 15:

[0166] This embodiment is a further optimization based on any one of the above embodiments 1-14. The near-infrared light field intermediate lens group B2 includes a near-infrared light field intermediate concave-convex lens B21. A near-infrared light field intermediate positioning step B22 is provided inside the lens barrel between the incident end and the exit end. The near-infrared light field intermediate concave-convex lens B21 and the near-infrared light field intermediate positioning step B22 are axially and circumferentially limited and connected. A near-infrared light field intermediate pressure ring B23 is coaxially provided on one side of the near-infrared light field intermediate concave-convex lens B21, which axially presses the near-infrared light field intermediate concave-convex lens B21 toward the near-infrared light field intermediate positioning step B22. A near-infrared light field intermediate grating structure B231 is provided on the inner wall of the near-infrared light field intermediate pressure ring B23.

[0167] The incident end face of the near-infrared light field central concave-convex lens B21 abuts against the axial end face of the near-infrared light field central positioning step B22. The near-infrared light field central pressure ring B23 axially presses the near-infrared light field central concave-convex lens B21 towards the near-infrared light field central positioning step B22, thereby achieving axial positioning of the near-infrared light field central concave-convex lens B21. The outer surface of the near-infrared light field central concave-convex lens B21 is circumferentially fitted with the step ring surface of the near-infrared light field central positioning step B22, thereby achieving circumferential positioning of the near-infrared light field central concave-convex lens B21.

[0168] An internal thread is provided on one side of the positioning step B22 in the middle of the near-infrared light field on the inner wall of the lens barrel. An external thread of the intermediate pressure ring B23 in the near-infrared light field is provided on the outer surface of the intermediate pressure ring, which is threadedly connected to the internal thread. By screwing the internal thread and the external thread, the intermediate pressure ring B23 in the near-infrared light field is fixedly installed inside the lens barrel. At the same time, by rotating the intermediate pressure ring B23, the intermediate pressure ring B23 in the near-infrared light field is axially pressed against the concave-convex lens B21 in the middle of the near-infrared light field.

[0169] A near-infrared light field intermediate grating structure B231 is provided on the inner wall of the light-transmitting hole at the center of the near-infrared light field intermediate pressure ring B23. The aperture of the near-infrared light field intermediate grating structure B231 is set to correspond to the edge of the effective light passing through the light-transmitting hole. Thus, the near-infrared light field intermediate grating structure B231 can block stray light that exceeds the edge range of the effective light, thereby reducing the adverse effect of stray light on the final image quality.

[0170] The other parts of this embodiment are the same as any one of the embodiments 1-14 above, so they will not be described again.

[0171] Example 16:

[0172] This embodiment is a further optimization based on any one of the above embodiments 1-15. The near-infrared light field intermediate grating structure B231 includes an incident flange. The incident flange is disposed at the incident end of the inner hole wall of the near-infrared light field intermediate pressure ring B23. The exit end of the inner hole wall of the near-infrared light field intermediate pressure ring B23 is connected to the incident flange through a slope inclined towards the central axis of the lens barrel.

[0173] Since the near-infrared light field intermediate pressure ring B23 is located at the exit end of the near-infrared light field intermediate concave-convex lens B21, and the near-infrared light field intermediate concave-convex lens B21 is used to diverge light, an incident flange is provided at the incident end of the inner wall of the light-transmitting hole at the center of the near-infrared light field intermediate pressure ring B23. The inclined surface is set with the diameter of the inclined surface incident end being smaller than the diameter of the inclined surface exit end, and the inclined surface incident end and the incident flange are smoothly connected. The inner diameter of the incident flange is set to correspond to the edge of the effective light, thereby blocking stray light that exceeds the edge range of the effective light and reducing the impact of stray light on the final image quality.

[0174] The other parts of this embodiment are the same as any one of the embodiments 1-15 above, so they will not be described again.

[0175] Example 17:

[0176] This embodiment is a further optimization based on any one of the above embodiments 1-16. The near-infrared light field emitting lens group B3 includes a near-infrared light field cemented convex lens B31. A near-infrared light field emitting positioning step B32 is provided inside the emitting end of the lens tube. The near-infrared light field cemented convex lens B31 and the near-infrared light field emitting positioning step B32 are axially and circumferentially limited and connected. A near-infrared light field emitting pressure ring B33 is provided on one side of the near-infrared light field cemented convex lens B31 to axially press the near-infrared light field cemented convex lens B31 toward the near-infrared light field emitting positioning step B32. A near-infrared light field emitting grating structure B331 is provided on the inner wall of the near-infrared light field emitting pressure ring B33.

[0177] The incident end face of the near-infrared light field cemented convex lens B31 abuts against the axial end face of the near-infrared light field exit positioning step B32. The near-infrared light field exit pressure ring B33 axially presses the near-infrared light field cemented convex lens B31 towards the near-infrared light field exit positioning step B32, thereby achieving axial positioning of the near-infrared light field cemented convex lens B31. The outer surface of the near-infrared light field cemented convex lens B31 is circumferentially fitted with the step ring surface of the near-infrared light field exit positioning step B32, thereby achieving circumferential positioning of the near-infrared light field cemented convex lens B31.

[0178] An internal thread for emission is provided on one side of the near-infrared light field emission positioning step B32 on the inner wall of the lens barrel. An external thread for emission pressure ring B33 is provided on the outer surface of the near-infrared light field emission pressure ring, which is threadedly connected to the internal thread for emission. By screwing the internal thread for emission and the external thread for emission pressure ring, the near-infrared light field emission pressure ring B33 is fixedly installed inside the lens barrel. At the same time, by rotating the near-infrared light field emission pressure ring B33, the near-infrared light field emission pressure ring B33 is axially pressed against the near-infrared light field cemented convex lens B31.

[0179] A near-infrared light field emission grating structure B331 is provided on the inner wall of the light-transmitting hole at the center of the near-infrared light field emission pressure ring B33. The aperture of the near-infrared light field emission grating structure B331 is set to correspond to the edge of the effective light passing through the light-transmitting hole. Thus, the near-infrared light field emission grating structure B331 can block stray light that exceeds the edge range of the effective light, thereby reducing the adverse effect of stray light on the final image quality.

[0180] The other parts of this embodiment are the same as any one of the embodiments 1-16 above, so they will not be described again.

[0181] Example 18:

[0182] This embodiment is a further optimization based on any one of the above embodiments 1-17. The near-infrared light field emission grating structure B331 includes an incident flange. The incident flange is disposed at the incident end of the inner hole wall of the near-infrared light field emission pressure ring B33. The emission end of the inner hole wall of the near-infrared light field emission pressure ring B33 is connected to the incident flange through a slope inclined towards the central axis of the lens barrel.

[0183] Since the near-infrared light field emission pressure ring B33 is located at the emission end of the near-infrared light field cemented convex lens B31, and the near-infrared light field cemented convex lens B31 is used to converge light, an incident flange is provided at the incident end of the inner wall of the light-transmitting aperture at the center of the near-infrared light field emission pressure ring B33. The inclined surface is set with the diameter of the inclined surface incident end being larger than the diameter of the inclined surface emission end, and the inclined surface incident end and the incident flange are smoothly connected. The inner diameter of the incident flange is set to correspond to the edge of the effective light, thereby blocking stray light that exceeds the edge range of the effective light and reducing the impact of stray light on the final image quality.

[0184] The other parts of this embodiment are the same as any one of the embodiments 1-17 above, so they will not be described again.

[0185] Example 19:

[0186] This embodiment is a further optimization based on any one of embodiments 1-18 above, such as... Figures 22-32As shown, the visible light imaging camera C includes a visible light incident lens group C1 and a visible light exiting lens group C3 arranged sequentially at the incident end of the lens barrel along the optical path. Inside the lens barrel, between the visible light incident lens group C1 and the visible light exiting lens group C3, a visible light intermediate lens group C2 is arranged. At least one grating structure for blocking stray light is arranged between the visible light incident lens group C1 and the visible light intermediate lens group C2, and between the visible light intermediate lens group C2 and the visible light exiting lens group C3. The exit end of the lens barrel is connected to a visible light imaging device C4 through a focusing unit, which is used to drive the visible light imaging device C4 to move axially relative to the exit end of the lens barrel.

[0187] The lens barrel is integrally molded, thus ensuring the coaxiality of the light transmission aperture inside the barrel. A visible light incident lens group C1 is detachably installed inside the incident end of the lens barrel, and a visible light exiting lens group C3 is detachably installed inside the exit end. A visible light intermediate lens group C2, coaxially matched with the visible light incident lens group C1 and the visible light exiting lens group C3, is detachably installed inside the lens barrel between the incident and exit ends, depending on the final imaging requirements. Through the integrated structure of the lens barrel itself and the internal positioning of the visible light incident lens group C1, the visible light intermediate lens group C2, and the visible light exiting lens group C3, the coaxiality among these three lens groups is ensured. By adjusting the focal length between the lens barrel and the visible light imaging device C4 through the focusing unit, the light reflected from the object is converged into the interior of the lens barrel through the visible light incident lens group C1. Then, the light path is adjusted by the cooperation of the visible light intermediate lens group C2 and the exit lens, so that the effective light reflected from the object can be concentrated and transmitted onto the target surface of the visible light imaging device C4, ultimately achieving high-definition and high-quality imaging. At the same time, as the effective light passes through the interior of the lens barrel, the grating structure inside the lens barrel blocks stray light that exceeds the edge of the effective light range, thereby effectively reducing the impact of stray light on the final imaging effect.

[0188] The other parts of this embodiment are the same as any one of the embodiments 1-18 above, so they will not be described again.

[0189] Example 20:

[0190] This embodiment is a further optimization based on any one of embodiments 1-19 above. A visible light blocking ring C5 is provided between the exit end of the visible light incident lens group C1 and the incident end of the visible light intermediate lens group C2, and a visible light blocking ring grating structure C51 is provided on the inner wall of the visible light blocking ring C5; a visible light intermediate pressure ring C6 is provided between the exit end of the visible light intermediate lens group C2 and the incident end of the visible light exiting lens group C3, and a visible light intermediate pressure ring grating structure C61 is provided on the inner wall of the visible light intermediate pressure ring C6; a visible light incident pressure ring C7 is provided inside the incident end of the lens barrel to axially press the visible light incident lens group C1 toward the visible light intermediate lens group C2, and a visible light incident pressure ring grating structure C71 is provided on the inner wall of the visible light incident pressure ring C7.

[0191] The visible light blocking ring C5 is coaxially positioned between the visible light incident lens group C1 and the visible light intermediate lens group C2. It is used to isolate the visible light incident lens group C1 and the visible light intermediate lens group C2. At the same time, the visible light blocking ring C5 axially limits the visible light incident lens group C1 and the visible light intermediate lens group C2, so that the visible light incident lens group C1 and the visible light intermediate lens group C2 remain stable inside the lens barrel.

[0192] A visible light blocking ring grating structure C51 is provided on the inner wall of the light-passing hole at the center of the visible light blocking ring C5. The inner diameter of the visible light blocking ring grating structure C51 is set to correspond to the edge contour of the effective light, so that the effective light can pass through the inner hole of the visible light blocking ring grating structure C51 normally. At the same time, the visible light blocking ring grating structure C51 can block stray light that exceeds the edge of the effective light, thereby reducing the influence of stray light on the effective light and improving the final image quality.

[0193] An internal thread is provided on the inner wall of the lens barrel between the exit end of the visible light intermediate lens group C2 and the incident end of the visible light exiting lens group C3. An external thread for the visible light intermediate retaining ring C6 is provided on the outer side of the retaining ring, which is threadedly engaged with the internal thread. By screwing the visible light intermediate retaining ring C6 onto the internal thread, the retaining ring C6 is installed inside the lens barrel. Simultaneously, by rotating the retaining ring C6, its end face axially presses against the visible light exiting lens group C3, thus axially positioning and fixing the visible light exiting lens group C3. In addition to axially pressing the visible light emitting lens group C3, the visible light intermediate pressure ring C6 also has a visible light intermediate pressure ring grating structure C61 on the inner wall of the light-transmitting hole at the center of the visible light intermediate pressure ring C6. The inner diameter of the visible light intermediate pressure ring grating structure C61 is set to correspond to the edge of the effective light, so that the effective light can pass through the inner hole of the visible light intermediate pressure ring grating structure C61 normally, but stray light that exceeds the edge of the effective light will be blocked by the visible light intermediate pressure ring grating structure C61.

[0194] An internal incident thread is provided on the inner wall of the incident end of the lens barrel, and an external incident thread is provided on the outer surface of the visible light incident pressure ring C7, which is threadedly engaged with the internal incident thread. By screwing the internal incident thread and the external incident thread, the visible light incident pressure ring C7 can be fixedly installed inside the lens barrel. At the same time, by rotating the visible light incident pressure ring C7, the visible light incident pressure ring C7 is axially moved towards the visible light intermediate lens group C2 to press the visible light incident lens group C1, thereby achieving axial positioning and fixation of the visible light incident lens group C1 and effectively preventing the visible light incident lens group C1 from shifting. Meanwhile, a visible light incident pressure ring grating structure C71 is provided on the inner wall of the light-transmitting hole at the center of the visible light incident pressure ring C7. The inner diameter of the visible light incident pressure ring grating structure C71 is set to correspond to the edge of the effective light, ensuring that the effective light can pass through the visible light incident pressure ring grating structure C71 normally, while blocking stray light that exceeds the effective light to the edge, reducing the impact of stray light on the final image quality.

[0195] The other parts of this embodiment are the same as any one of the embodiments 1-19 above, so they will not be described again.

[0196] Example 21:

[0197] This embodiment is a further optimization based on any one of the above embodiments 1-20. The visible light blocking ring grating structure C51 includes an incident flange and an exit flange. The incident flange is disposed at the incident end of the inner hole wall of the visible light blocking ring C5, and the exit flange is disposed at the exit end of the inner hole wall of the visible light blocking ring C5. The inner hole wall of the visible light blocking ring C5 is provided with a recessed portion in the direction of being recessed away from the central axis of the lens barrel at a position between the incident flange and the exit flange.

[0198] The inner diameter of the incident flange is 32mm-33.5mm, and the inner diameter of the exit flange is 30.5mm-32mm. Both the incident and exit flanges are positioned close to the edge of the light beam to block stray light that exceeds the edge. The diameter of the recess is 32mm-35mm. The recess reflects stray light, further weakening it, and also reduces the weight of the visible light blocking ring grating structure C51.

[0199] The axial thickness of the visible light blocking ring grating structure C51 is 3.8mm-4.4mm.

[0200] The other parts of this embodiment are the same as any one of the embodiments 1-20 above, so they will not be described again.

[0201] Example 22:

[0202] This embodiment is a further optimization based on any one of the above embodiments 1-21. The visible light intermediate pressure ring grating structure C61 includes an exit flange, which is disposed at the exit end of the inner hole wall of the visible light intermediate pressure ring C6. The incident end of the inner hole wall of the visible light intermediate pressure ring C6 is connected to the exit flange through a slope inclined towards the central axis of the lens barrel.

[0203] The inner diameter of the emission flange is 21.6mm-22.4mm. The emission flanges are all set close to the edge of the light to block stray light that exceeds the edge of the light. The axial length of the visible light intermediate pressure ring grating structure C61 is 2.8mm-3.3mm.

[0204] The other parts of this embodiment are the same as any one of the embodiments 1-21 above, so they will not be described again.

[0205] Example 23:

[0206] This embodiment is a further optimization based on any one of the above embodiments 1-22. The visible light incident pressure ring grating structure C71 includes an exit flange, which is disposed at the exit end of the inner hole wall of the visible light incident pressure ring C7. The incident end of the inner hole wall of the visible light incident pressure ring C7 is connected to the exit flange through a slope inclined towards the central axis of the lens barrel.

[0207] The inner diameter of the exit flange is 34.2mm-35.5mm, and the exit flange is set close to the edge of the light beam to block stray light that exceeds the edge of the light beam. The angle between the inclined plane and the central axis is 148°-152.15°.

[0208] The exit end face of the visible light incident pressure ring C7 is provided with a clearance groove to avoid interference with the lens. The diameter of the clearance groove is 36mm-38.5mm.

[0209] The other parts of this embodiment are the same as any one of the embodiments 1-22 above, so they will not be described again.

[0210] Example 24:

[0211] This embodiment is a further optimization based on any one of the above embodiments 1-23. The visible light incident lens group C1 includes a visible light incident biconvex lens C11 and a visible light incident plane mirror C12 arranged along the optical path. A visible light incident positioning step C13 is provided inside the incident end of the lens tube. The visible light incident plane mirror C12 and the visible light incident positioning step C13 are axially and circumferentially positioned and locked. A visible light incident spacer C14 is provided between the incident end of the visible light incident plane mirror C12 and the exit end of the visible light incident biconvex lens C11.

[0212] The end face of the visible light incident plane mirror C12, near the visible light intermediate lens group C2, abuts against the axial end face of the visible light incident positioning step C13, thereby achieving axial positioning of the visible light incident plane mirror C12. Simultaneously, the outer surface of the visible light incident plane mirror C12 circumferentially engages with the circumferential step ring of the visible light incident positioning step C13, achieving circumferential positioning of the visible light incident plane mirror C12. A visible light incident spacer C14 is coaxially positioned between the end face of the visible light incident plane mirror C12, away from the visible light intermediate lens group C2, and the visible light incident biconvex lens C11, thereby axially isolating the visible light incident biconvex lens C11 and the visible light incident plane mirror C12. The incident surface of the visible light incident biconvex lens C11 is axially pressed by the visible light incident pressure ring C7. The entire visible light incident lens group C1 is axially fixed by the cooperation between the visible light incident pressure ring C7 and the visible light incident positioning step C13.

[0213] The other parts of this embodiment are the same as any one of the embodiments 1-23 above, so they will not be described again.

[0214] Example 25:

[0215] This embodiment is a further optimization based on any one of the above embodiments 1-24. The visible light intermediate lens group C2 includes a visible light intermediate concave-convex lens C21 and a visible light intermediate concave lens C22 arranged sequentially along the optical path. A visible light intermediate positioning step C23 is provided inside the lens barrel between the incident end and the exit end. The visible light intermediate concave lens C22 and the visible light intermediate positioning step C23 are axially and circumferentially positioned and engaged. A visible light intermediate spacer C24 is provided between the visible light intermediate concave lens C22 and the visible light intermediate concave-convex lens C21.

[0216] The end face of the visible light intermediate concave lens C22, near the visible light exiting lens group C3, mates with the axial end face of the visible light intermediate positioning step C23, thereby achieving axial positioning of the visible light intermediate concave lens C22. Simultaneously, the outer surface of the visible light intermediate concave lens C22 circumferentially mates with the circumferential step of the visible light intermediate positioning step C23, achieving circumferential positioning of the visible light intermediate concave lens C22. A visible light intermediate spacer C24 is coaxially positioned between the end face of the visible light intermediate concave lens C22, away from the visible light exiting lens group C3, and the visible light intermediate concave-convex lens C21, axially isolating the visible light intermediate concave-convex lens C21 and the visible light intermediate concave lens C22. The incident surface of the visible light intermediate concave-convex lens C21 is axially pressed by the visible light tube retaining ring C5, and the engagement of the visible light tube retaining ring C5 with the visible light intermediate positioning step C23 achieves axial fixation of the entire visible light intermediate lens group C2.

[0217] The other parts of this embodiment are the same as any one of the embodiments 1-24 above, so they will not be described again.

[0218] Example 26:

[0219] This embodiment is a further optimization based on any one of the above embodiments 1-25. The visible light emitting lens group C3 includes a first visible light emitting concave-convex lens C31 and a second visible light emitting concave-convex lens C32 arranged sequentially along the optical path. A visible light emitting positioning step C33 is provided inside the lens barrel at the emitting end. The second visible light emitting concave-convex lens C32 is axially and circumferentially positioned and engaged with the visible light emitting positioning step C33. A visible light separator C34 is coaxially arranged between the first visible light emitting concave-convex lens C31 and the second visible light emitting concave-convex lens C32. At least one visible light separator grating structure C341 is provided on the inner wall of the visible light separator C34.

[0220] Inside the lens tube, at the exit end, there is a visible light emission positioning step C33. The second visible light emission concave-convex lens C32 is axially and circumferentially positioned and engaged with the visible light emission positioning step C33. A visible light separator C34 is coaxially arranged between the first visible light emission concave-convex lens C315 and the second visible light emission concave-convex lens C32.

[0221] The exit face of the second visible light emitting concave-convex lens C32 abuts against the axial face of the visible light emitting positioning step C33, thereby achieving axial positioning of the second visible light emitting concave-convex lens C32. Simultaneously, the outer surface of the second visible light emitting concave-convex lens C32 circumferentially engages with the circumferential step of the visible light emitting positioning step C33, achieving circumferential positioning of the second visible light emitting concave-convex lens C32. A visible light separator C34 is coaxially disposed between the incident end of the second visible light emitting concave-convex lens C32 and the exit end of the first visible light emitting concave-convex lens C315, isolating the first visible light emitting concave-convex lens C315 and the second visible light emitting concave-convex lens C32 through the visible light separator C34.

[0222] The other parts of this embodiment are the same as any one of the embodiments 1-25 above, so they will not be described again.

[0223] Example 27:

[0224] This embodiment is a further optimization based on any one of the above embodiments 1-26. The visible light grating structure C341 includes a grating step or a grating inclined surface that is inclined toward the central axis of the lens barrel and disposed on the inner wall of the visible light grating C34.

[0225] The other parts of this embodiment are the same as any one of the embodiments 1-26 above, so they will not be described again.

[0226] Example 28:

[0227] This embodiment is a further optimization based on any one of embodiments 1-27 above, such as... Figures 33-35 As shown, the infrared imaging camera D includes an infrared imaging device D3. A focusing unit is installed at the incident end of the infrared imaging device D3. The exit end of the focusing unit is coaxially connected to the incident end of the infrared imaging device D3. A lens assembly is installed at the incident end of the focusing unit with relative axial movement. At least one set of infrared incident lens group D1 is installed at the incident end of the lens assembly, and at least one set of infrared exit lens group D2 is installed at the exit end of the lens assembly. At least one set of grating structure is provided between the infrared incident lens group D1 and the infrared exit lens group D2.

[0228] The incident end of the infrared imaging device D3 is coaxially connected to a focusing connection part via a connecting bolt. The incident end of the focusing connection part is coaxially connected to a lens assembly. The axial distance between the infrared imaging device D3 and the lens assembly can be adjusted axially through the focusing connection part, thereby adjusting the final imaging focal length to obtain a clearer image quality.

[0229] Meanwhile, an outer support frame is provided at the bottom of the infrared imaging device D3. The bottom of the infrared imaging device D3 is connected to the outer support frame via connecting bolts, and the outer support frame provides stable support for the heavy infrared imaging device D3. Support legs are provided on both sides of the bottom of the outer support frame, and axial oblong grooves are provided on the support legs. Adjusting bolts are slidably inserted into the axial oblong grooves.

[0230] The lens assembly has at least one infrared incident lens group D1 at its incident end, and the infrared incident lens group D1 includes at least one incident lens unit. The lens assembly also has at least one infrared exiting lens group D2 at its exit end, and the infrared exiting lens group D2 includes at least one exiting lens unit. At least one level of optical filter grating structure is provided between the infrared incident lens group D1 and the infrared exiting lens group D2. This grating structure blocks stray light from the light source, and the infrared incident lens group D1 and the infrared exiting lens group D2 work together to adjust the optical path of the light, allowing the effective light to be concentrated and transmitted onto the detection surface of the infrared imaging device D3 to achieve a clear image.

[0231] The other parts of this embodiment are the same as any one of the embodiments 1-27 above, so they will not be described again.

[0232] Example 29:

[0233] This embodiment is a further optimization based on any one of embodiments 1-28 above. The lens assembly includes a lens barrel. The inner interior of the incident end of the lens barrel is coaxially provided with an infrared incident end positioning step D4 and an infrared incident end threaded retaining ring D5. An infrared incident lens group D1 is coaxially disposed between the infrared incident end positioning step D4 and the infrared incident end threaded retaining ring D5. The infrared incident end threaded retaining ring D5 presses against the infrared incident lens group D1 in a direction close to the infrared incident end positioning step D4. The inner interior of the exit end of the lens barrel is coaxially provided with an infrared exit end positioning step D6 and an infrared exit end threaded retaining ring D7. An infrared exit lens group D2 is coaxially disposed between the infrared exit end positioning step D6 and the infrared exit end threaded retaining ring D7. The infrared exit end threaded retaining ring D7 presses against the infrared exit lens group D2 in a direction close to the infrared exit end positioning step D6.

[0234] The inner wall of the incident end of the lens barrel is provided with an internal thread, and the outer surface of the infrared incident end threaded pressure ring D5 is provided with an external thread that engages with the internal thread. Inside the incident end of the lens barrel, on the side of the infrared incident end threaded pressure ring D5 near the exit end, is an infrared incident end positioning step D4. The infrared incident lens group D1 is coaxially positioned between the infrared incident end threaded pressure ring D5 and the infrared incident end positioning step D4. One end face of the infrared incident lens group D1 abuts against the axial positioning end face of the infrared incident end positioning step D4, while the other end face of the infrared incident lens group D1 abuts against the axial positioning end face of the infrared incident end threaded pressure ring D5. By rotating the infrared incident end threaded pressure ring D5, the axial positioning end face of the infrared incident end threaded pressure ring D5 is directed towards the infrared incident end positioning step D4, pressing the infrared incident lens group D1, thereby achieving axial positioning of the infrared incident lens group D1 inside the lens barrel. Meanwhile, the step ring surface of the infrared incident end positioning step D4 is circumferentially connected to the outer surface of the infrared incident lens group D1, thereby realizing the circumferential positioning of the infrared incident lens group D1, and ultimately preventing the infrared incident lens group D1 from moving circumferentially or axially inside the lens barrel, thus ensuring the stability of the infrared incident lens group D1.

[0235] The inner wall of the lens barrel's exit end is provided with an internal thread, and the outer surface of the infrared exit end threaded pressure ring D7 is provided with an external thread that engages with the internal thread. Inside the lens barrel's exit end, on the side of the infrared exit end threaded pressure ring D7 closest to the exit end, is an infrared exit end positioning step D6. The infrared exit lens group D1 is coaxially positioned between the infrared exit end threaded pressure ring D7 and the infrared exit end positioning step D6.

[0236] One end face of the infrared emitting lens group D2 abuts against the axial positioning end face of the infrared emitting end positioning step D6, while the other end face of the infrared emitting lens group D2 abuts against the axial positioning end face of the infrared emitting end threaded pressure ring D7. By rotating the infrared emitting end threaded pressure ring D7, the axial positioning end face of the infrared emitting end threaded pressure ring D7 is pressed against the infrared emitting lens group D2 in a direction closer to the infrared emitting end positioning step D6, thereby achieving axial positioning of the infrared emitting lens group D2 inside the lens barrel. At the same time, the stepped annular surface of the infrared emitting end positioning step D6 is circumferentially engaged with the outer surface of the infrared emitting lens group D2, thereby achieving circumferential positioning of the infrared emitting lens group D2. Ultimately, this prevents the infrared emitting lens group D2 from moving circumferentially or axially inside the lens barrel, ensuring the stability of the infrared emitting lens group D2.

[0237] The other parts of this embodiment are the same as any one of the embodiments 1-28 above, so they will not be described again.

[0238] Example 30:

[0239] This embodiment further optimizes any one of embodiments 1-29 above. An infrared multi-level grating structure D100 is provided on the inner wall of the threaded pressure ring D5 at the infrared incident end, and a grating inclined surface inclined towards the central axis of the lens barrel is provided at the inner hole of the positioning step D4 at the infrared incident end; an infrared multi-level grating structure D100 is provided on the inner wall of the threaded pressure ring D7 at the infrared exit end, and a grating inclined surface inclined towards the central axis of the lens barrel is provided at the inner hole of the positioning step D6 at the infrared exit end; the cooperation between the infrared multi-level grating structure D100 and the grating inclined surface can effectively block stray light in the light, avoiding stray light from adversely affecting the final imaging quality.

[0240] The infrared multi-level grating structure D100 includes three levels of stepped holes coaxially arranged on the inner wall of the pressure ring. The aperture of the three stepped holes decreases sequentially along the optical path, which can block stray light in the light step by step.

[0241] The other parts of this embodiment are the same as any one of the embodiments 1-29 above, so they will not be described again.

[0242] Example 31:

[0243] This embodiment further optimizes any one of embodiments 1-30 above. The infrared incident lens group D1 includes an infrared incident concave-convex lens D11, where the curvature of the incident convex surface and the exit concave surface of the infrared incident concave-convex lens D11 are different. The infrared exit lens group D2 includes an infrared exit concave-convex lens D21 and an infrared exit biconvex lens D22. The infrared exit concave-convex lens D21 is coaxially disposed between the infrared exit biconvex lens D22 and the infrared incident lens group D1. The curvature of the incident convex surface and the exit concave surface of the infrared exit concave-convex lens D21 are different, and the curvature of the incident convex surface and the exit convex surface of the infrared exit biconvex lens D22 are also different. Other parts of this embodiment are the same as any one of embodiments 1-30 above, and therefore will not be described again.

[0244] Example 32:

[0245] This embodiment is a further optimization based on any one of the above embodiments 1-31. An infrared spacer D23 is coaxially arranged between the infrared emitting concave-convex lens D21 and the infrared emitting biconvex lens D22. One end of the infrared spacer D23 is pressed against the infrared emitting concave-convex lens D21 in the direction close to the threaded pressure ring D7 of the infrared emitting end, and the other end of the infrared spacer D23 is pressed against the infrared emitting biconvex lens D22 in the direction close to the positioning step D6 of the infrared emitting end. At least one grating inclined surface is provided on the inner wall of the infrared spacer D23, which is inclined towards the central axis of the lens barrel. The cooperation between the infrared multi-level grating structure D100 and the grating inclined surface can effectively block stray light in the light, so as to avoid stray light from having an adverse effect on the final imaging quality.

[0246] The other parts of this embodiment are the same as any one of the embodiments 1-31 above, so they will not be described again.

[0247] Example 33:

[0248] This embodiment is a further optimization based on any one of embodiments 1-32 above:

[0249] (1) The parameters of the near-infrared multispectral imaging camera are shown in the table below:

[0250]

[0251]

[0252] By combining the above parameters, the field of view of the automatically filtered near-infrared multispectral imaging camera is 5.23°×4.19°; the imaging focal length is 138.6mm-141.4mm; the imaging wavelength is 650nm-1100nm; the aperture number is 3.5-3.7; the MTF is ≥0.35@100lp / mm; and the blur spot is ≤2 times the diffraction limit.

[0253] (2) The parameters of the near-infrared light field imaging camera are shown in the table below:

[0254]

[0255]

[0256] By combining the above parameters, the near-infrared light field imaging camera achieves a field of view of 5.64°×4.51°; an imaging focal length of 128.7mm-131.3mm; an imaging wavelength of 650nm-1100nm; an aperture of 3.5-3.7; an MTF ≥ 0.35@100lp / mm; and a diffusion spot ≤ 2 times the diffraction limit.

[0257] (3) The parameters of the visible light imaging camera are shown in the table below:

[0258]

[0259] By combining the above parameters, the visible light imaging camera achieves a field of view of 4.8°×3.6°; an imaging focal length of 85.14mm-86.86mm; an imaging wavelength of 450nm-6500nm; an aperture of 2.4-2.6; an MTF ≥ 0.5@100lp / mm; and a diffusion spot ≤ 2 times the diffraction limit.

[0260] (4) The parameters of the infrared imaging camera are shown in the table below:

[0261]

[0262] By combining the above parameters, the infrared imaging camera achieves a field of view of 11.3°×9.05°; an imaging focal length of 54.45-55.55mm; an imaging wavelength of 8μm-12μm; an aperture number of 1.2-1.3; an MTF ≥ 0.25@30lp / mm; and a spot size ≤ 2 times the diffraction limit.

[0263] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A four-channel polarization imaging system, comprising a housing, characterized in that, The encapsulation shell has four acquisition channels inside, and the four acquisition channels are respectively equipped with a near-infrared multispectral imaging camera (A), a near-infrared light field imaging camera (B), a visible light imaging camera (C), and an infrared imaging camera (D) to perform multi-dimensional imaging detection of objects. The near-infrared multispectral imaging camera (A) is equipped with an adjustable filter inside, through which light of different wavelengths is transmitted. The near-infrared light field imaging camera (B) is equipped with a polarization device, which polarizes the light to form an image. The near-infrared light field imaging camera (B) includes a near-infrared light field incident lens group (B1) and a near-infrared light field exit lens group (B3) disposed inside the lens barrel along the optical path direction. A near-infrared light field intermediate lens group (B2) is disposed inside the lens barrel between the incident end and the exit end. A polarization device (B4) is detachably disposed between the incident end of the near-infrared light field intermediate lens group (B2) and the exit end of the near-infrared light field incident lens group (B1). At least one grating structure for blocking stray light is disposed inside the lens barrel along the optical path direction. The exit end of the lens barrel is connected to a near-infrared light field imaging device (B5) through a focusing part. The focusing part is used to drive the exit end of the lens barrel to move axially relative to the incident end of the near-infrared light field imaging device (B5) to adjust the imaging focal length. The near-infrared light field incident lens group (B1) includes a first near-infrared light field incident concave-convex lens (B11) and a second near-infrared light field incident concave-convex lens (B12) arranged sequentially along the optical path. The incident surface of the first near-infrared light field incident concave-convex lens (B11) is convex, the exit surface is concave, and the curvature of the incident surface of the first near-infrared light field incident concave-convex lens (B11) is greater than or equal to the curvature of the exit surface of the first near-infrared light field incident concave-convex lens (B11). The incident surface of the second near-infrared light field incident concave-convex lens (B12) is convex, and the exit surface is concave. The curvature of the incident surface of the second near-infrared light field incident concave-convex lens (B12) is greater than or equal to the curvature of the exit surface of the second near-infrared light field incident concave-convex lens (B12). A near-infrared light field incident pressure ring (B45) is provided to axially press the second near-infrared light field incident concave-convex lens (B12), and a near-infrared light field incident grating structure (B451) is provided on the inner wall of the near-infrared light field incident pressure ring (B45). The near-infrared light field incident grating structure (B451) includes an exit flange, which is disposed at the exit end of the inner hole wall of the near-infrared light field incident pressure ring (B45). The incident end of the inner hole wall of the near-infrared light field incident pressure ring (B45) is transitionally connected to the exit flange through an inclined surface oriented towards the central axis of the lens barrel. The near-infrared light field intermediate lens group (B2) includes a near-infrared light field intermediate concave-convex lens (B21), with an incident surface that is concave and an exit surface that is convex. The near-infrared light field exit lens group (B3) includes a near-infrared light field cemented convex lens (B31). The visible light imaging camera (C) is used to collect and image light within the visible wavelength range; the infrared imaging camera (D) is used to collect and image light within the infrared wavelength range.

2. The four-channel polarization imaging system according to claim 1, characterized in that, The near-infrared multispectral imaging camera (A) includes a front lens assembly (A1), a filter assembly (A2), a rear lens assembly (A3), and a near-infrared multispectral imaging device (A4) coaxially arranged inside the lens barrel. The front lens assembly (A1) is used to adjust the light transmission to an angle of less than or equal to 1° with the axis. The filter assembly (A2) is used to automatically selectively transmit light within a specific wavelength range. The rear lens assembly (A3) is used to adjust the light to be within the effective imaging light range of the near-infrared multispectral imaging device (A4). The near-infrared multispectral imaging device (A4) is axially movable relative to the exit end of the rear lens assembly (A3) to achieve axial movement focusing imaging of the near-infrared multispectral imaging device (A4) itself. At least one grating structure for blocking stray light is arranged inside the lens barrel along the optical path.

3. A four-channel polarization imaging system according to claim 2, characterized in that, The incident end of the filter assembly (A2) is coaxially provided with a light hole and a threaded hole along the optical axis. The light hole is connected to the exit end shaft hole of the front lens assembly (A1), and the threaded hole is connected to the exit end of the front lens assembly (A1) with a thread. The exit end of the filter assembly (A2) is provided with a light hole, and the light hole is connected to the incident end shaft hole of the rear lens assembly (A3).

4. A four-channel polarization imaging system according to claim 3, characterized in that, The front lens assembly (A1) includes a front lens barrel, a convex lens group (A11), and a concave lens group (A12). The front lens barrel has an incident end with the convex lens group (A11), which includes a first near-infrared multispectral biconvex lens (A111) and a second near-infrared multispectral biconvex lens (A112) coaxially disposed at the incident end of the front lens barrel. A first positioning step is provided inside the incident end of the front lens barrel, and a second positioning step is provided inside the exit end of the front lens barrel. The first near-infrared multispectral biconvex lens (A111) and the first positioning step limit the axial and circumferential directions. The second near-infrared multispectral biconvex lens (A112) is axially and circumferentially engaged with the second positioning step; the front concave lens group (A12) includes a first near-infrared multispectral biconvex lens (A121) and a second near-infrared multispectral biconvex lens (A122) coaxially disposed at the exit end of the front lens barrel, and a third positioning step and a fourth positioning step are disposed inside the exit end of the front lens barrel. The first near-infrared multispectral biconvex lens (A121) is axially and circumferentially engaged with the third positioning step, and the second near-infrared multispectral biconvex lens (A122) is axially and circumferentially engaged with the fourth positioning step.

5. A four-channel polarization imaging system according to claim 4, characterized in that, The first near-infrared multispectral biconvex lens (A111) is provided with a first threaded retaining ring (A13) on the side away from the first positioning step, which presses the first near-infrared multispectral biconvex lens (A111) toward the first positioning step. The second near-infrared multispectral biconvex lens (A112) is provided with a second threaded retaining ring (A14) on the side away from the second positioning step, which presses the second near-infrared multispectral biconvex lens (A112) toward the second positioning step. The inner walls of the first threaded retaining ring (A13) and the second threaded retaining ring (A14) are each provided with a near-infrared multispectral retaining ring grating structure (A100). The near-infrared multispectral retaining ring grating structure (A100) includes a light-blocking flange provided on the inner wall of the first threaded retaining ring (A13) or the second threaded retaining ring (A14) and an inclined surface that transitions to and connects with the light-blocking flange.

6. A four-channel polarization imaging system according to claim 3, characterized in that, The rear lens assembly (A3) includes a rear lens barrel, with a rear convex lens group (A31) disposed inside the incident end of the rear lens barrel and a rear concave-convex lens group (A32) disposed inside the exit end of the rear lens barrel; the rear convex lens group (A31) includes a third near-infrared multispectral biconvex lens (A311) disposed at the incident end of the rear lens barrel, and the rear concave-convex lens group (A32) includes a near-infrared multispectral cemented concave-convex lens (A321) disposed at the exit end of the rear lens barrel; the exit end of the rear lens barrel is connected to the incident end of the imaging assembly (A4) through a focusing part, the focusing part being used to drive the imaging assembly (A4) to move axially closer to or away from the exit end of the rear lens barrel.

7. A four-channel polarization imaging system according to claim 6, characterized in that, The rear lens barrel has a fifth positioning step inside the incident end and a sixth positioning step inside the exit end. The third near-infrared multispectral biconvex lens (A311) is axially and circumferentially engaged with the fifth positioning step, and the near-infrared multispectral cemented concave-convex lens (A321) is axially and circumferentially engaged with the sixth positioning step.

8. A four-channel polarization imaging system according to claim 7, characterized in that, The third near-infrared multispectral biconvex lens (A311) is provided with a third threaded retaining ring (A15) on the side away from the fifth positioning step, which axially presses the third near-infrared multispectral biconvex lens (A311) toward the fifth positioning step; the near-infrared multispectral cemented concave-convex lens (A321) is provided with a fourth threaded retaining ring (A16) on the side away from the sixth positioning step, which axially presses the near-infrared multispectral cemented concave-convex lens (A321) toward the sixth positioning step; both the inner walls of the third threaded retaining ring (A15) and the fourth threaded retaining ring (A16) are provided with near-infrared multispectral retaining ring grating structures (A100); the near-infrared multispectral retaining ring grating structure (A100) includes a light-blocking flange provided on the inner wall of the third threaded retaining ring (A15) or the fourth threaded retaining ring (A16) and an inclined surface that transitions to and connects with the light-blocking flange.

9. A four-channel polarization imaging system according to claim 7, characterized in that, The filter assembly (A2) includes a filter base, and an adjustable filter (A21) or a switchable filter assembly (A22) is detachably disposed inside the filter base. The adjustable filter (A21) is used for automatic filtering, and the switchable filter assembly (A22) is used for manual filtering.

10. A four-channel polarization imaging system according to claim 7, characterized in that, The filter assembly (A2) includes a switching filter assembly (A22), which includes a switching cylinder (A221) detachably mounted on the filter base. The incident end of the switching cylinder (A221) is coaxially and detachably connected to the exit end of the front lens assembly (A1), and the exit end of the switching cylinder (A221) is coaxially and detachably connected to the incident end of the rear lens assembly (A3). A filter unit is detachably mounted inside the switching cylinder (A221), and the filter unit includes at least one bandpass filter (A222) and at least one flat lens (A223) coaxially mounted with the bandpass filter (A222).

11. A four-channel polarization imaging system according to claim 1, characterized in that, The polarization device (B4) includes a polarization frame (B41) and a polarizer (B42). The polarization frame (B41) is detachably installed between the incident end of the near-infrared light field intermediate lens group (B2) and the exit end of the near-infrared light field incident lens group (B1). A polarization mounting step hole (B43) is provided on the polarization frame (B41) corresponding to the optical path. The polarizer (B42) is installed inside the polarization mounting step hole (B43). A glue injection groove (B44) is provided on the hole wall of the polarization mounting step hole (B43) corresponding to the edge of the polarizer (B42).

12. A four-channel polarization imaging system according to claim 11, characterized in that, The incident end of the lens tube is provided with a plurality of fixing devices (B13) along the circumferential direction to hold the first near-infrared light field incident concave-convex lens (B11) tightly; a near-infrared light field incident positioning step (B14) is provided on one side of the second near-infrared light field incident concave-convex lens (B12).

13. A four-channel polarization imaging system according to claim 1, characterized in that, The lens barrel has a near-infrared light field intermediate positioning step (B22) located between the incident end and the exit end. The near-infrared light field intermediate concave-convex lens (B21) is axially and circumferentially limited and connected to the near-infrared light field intermediate positioning step (B22). A near-infrared light field intermediate pressure ring (B23) is coaxially arranged on one side of the near-infrared light field intermediate concave-convex lens (B21) to axially press the near-infrared light field intermediate concave-convex lens (B21) toward the near-infrared light field intermediate positioning step (B22). A near-infrared light field intermediate grating structure (B231) is provided on the inner wall of the near-infrared light field intermediate pressure ring (B23).

14. A four-channel polarization imaging system according to claim 13, characterized in that, The near-infrared light field intermediate grating structure (B231) includes an incident flange, which is disposed at the incident end of the inner hole wall of the near-infrared light field intermediate pressure ring (B23). The exit end of the inner hole wall of the near-infrared light field intermediate pressure ring (B23) is connected to the incident flange through a slope inclined towards the central axis of the lens barrel.

15. A four-channel polarization imaging system according to claim 1, characterized in that, The lens barrel has a near-infrared light field emission positioning step (B32) inside the emission end. The near-infrared light field cemented convex lens (B31) is axially and circumferentially limited and connected to the near-infrared light field emission positioning step (B32). A near-infrared light field emission pressure ring (B33) is provided on one side of the near-infrared light field cemented convex lens (B31) to axially press the near-infrared light field cemented convex lens (B31) toward the near-infrared light field emission positioning step (B32). A near-infrared light field emission grating structure (B331) is provided on the inner wall of the near-infrared light field emission pressure ring (B33).

16. A four-channel polarization imaging system according to claim 15, characterized in that, The near-infrared light field emission grating structure (B331) includes an incident flange, which is disposed at the incident end of the inner hole wall of the near-infrared light field emission pressure ring (B33). The emission end of the inner hole wall of the near-infrared light field emission pressure ring (B33) is transitionally connected to the incident flange through an inclined surface that is inclined toward the central axis of the lens barrel.

17. A four-channel polarization imaging system according to claim 1, characterized in that, The visible light imaging camera (C) includes a visible light incident lens group (C1) arranged sequentially along the optical path at the incident end of the lens barrel and a visible light exiting lens group (C3) arranged at the exit end of the lens barrel. A visible light intermediate lens group (C2) is arranged inside the lens barrel between the visible light incident lens group (C1) and the visible light exiting lens group (C3). At least one grating structure for blocking stray light is arranged between the visible light incident lens group (C1) and the visible light intermediate lens group (C2) and between the visible light intermediate lens group (C2) and the visible light exiting lens group (C3). A visible light imaging device (C4) is connected to the exit end of the lens barrel through a focusing part. The focusing part is used to drive the visible light imaging device (C4) to move axially relative to the exit end of the lens barrel.

18. A four-channel polarization imaging system according to claim 17, characterized in that, A visible light blocking ring (C5) is provided between the exit end of the visible light incident lens group (C1) and the incident end of the visible light intermediate lens group (C2), and a visible light blocking ring grating structure (C51) is provided on the inner wall of the visible light blocking ring (C5); a visible light intermediate pressure ring (C6) is provided between the exit end of the visible light intermediate lens group (C2) and the incident end of the visible light exit lens group (C3), and a visible light intermediate pressure ring grating structure (C61) is provided on the inner wall of the visible light intermediate pressure ring (C6); a visible light incident pressure ring (C7) is provided inside the incident end of the lens barrel to axially press the visible light incident lens group (C1) toward the visible light intermediate lens group (C2), and a visible light incident pressure ring grating structure (C71) is provided on the inner wall of the visible light incident pressure ring (C7).

19. A four-channel polarization imaging system according to claim 18, characterized in that, The visible light blocking ring grating structure (C51) includes an incident flange and an exit flange. The incident flange is disposed at the incident end of the inner hole wall of the visible light blocking ring (C5), and the exit flange is disposed at the exit end of the inner hole wall of the visible light blocking ring (C5). The inner hole wall of the visible light blocking ring (C5) is provided with a recessed portion in the direction away from the central axis of the lens barrel at a position between the incident flange and the exit flange.

20. A four-channel polarization imaging system according to claim 18, characterized in that, The visible light intermediate pressure ring grating structure (C61) includes an exit flange, which is disposed at the exit end of the inner hole wall of the visible light intermediate pressure ring (C6). The incident end of the inner hole wall of the visible light intermediate pressure ring (C6) is connected to the exit flange by a slope inclined towards the central axis of the lens barrel.

21. A four-channel polarization imaging system according to claim 18, characterized in that, The visible light incident pressure ring grating structure (C71) includes an exit flange, which is disposed at the exit end of the inner hole wall of the visible light incident pressure ring (C7). The incident end of the inner hole wall of the visible light incident pressure ring (C7) is connected to the exit flange by a slope inclined towards the central axis of the lens barrel.

22. A four-channel polarization imaging system according to claim 17, characterized in that, The visible light incident lens group (C1) includes a visible light incident biconvex lens (C11) and a visible light incident plane mirror (C12) arranged along the optical path; a visible light incident positioning step (C13) is provided inside the incident end of the lens tube; the visible light incident plane mirror (C12) and the visible light incident positioning step (C13) are axially and circumferentially positioned and locked; a visible light incident spacer (C14) is provided between the incident end of the visible light incident plane mirror (C12) and the exit end of the visible light incident biconvex lens (C11).

23. A four-channel polarization imaging system according to claim 17, characterized in that, The visible light intermediate lens group (C2) includes a visible light intermediate concave-convex lens (C21) and a visible light intermediate concave lens (C22) arranged sequentially along the optical path. A visible light intermediate positioning step (C23) is provided inside the lens barrel between the incident end and the exit end. The visible light intermediate concave lens (C22) and the visible light intermediate positioning step (C23) are axially and circumferentially positioned and engaged. A visible light intermediate spacer (C24) is provided between the visible light intermediate concave lens (C22) and the visible light intermediate concave-convex lens (C21).

24. A four-channel polarization imaging system according to claim 17, characterized in that, The visible light emitting lens group (C3) includes a first visible light emitting concave-convex lens (C31) and a second visible light emitting concave-convex lens (C32) arranged sequentially along the optical path. A visible light emitting positioning step (C33) is provided inside the lens barrel at the emitting end. The second visible light emitting concave-convex lens (C32) is axially and circumferentially positioned and engaged with the visible light emitting positioning step (C33). A visible light separator (C34) is coaxially arranged between the first visible light emitting concave-convex lens (C31) and the second visible light emitting concave-convex lens (C32). At least one visible light separator grating structure (C341) is provided on the inner wall of the visible light separator (C34).

25. A four-channel polarization imaging system according to claim 24, characterized in that, The visible light grating structure (C341) includes a grating step or a grating slope inclined toward the central axis of the lens barrel, which is disposed on the inner wall of the visible light grating (C34).

26. A four-channel polarization imaging system according to claim 1, characterized in that, The infrared imaging camera (D) includes an infrared imaging device (D3). A focusing unit is installed at the incident end of the infrared imaging device (D3). The exit end of the focusing unit is coaxially connected to the incident end of the infrared imaging device (D3). A lens assembly is mounted on the incident end of the focusing unit with relative axial movement. At least one set of infrared incident lens groups (D1) is installed at the incident end of the lens assembly, and at least one set of infrared exit lens groups (D2) is installed at the exit end of the lens assembly. At least one set of grating structures is provided between the infrared incident lens group (D1) and the infrared exit lens group (D2).

27. A four-channel polarization imaging system according to claim 26, characterized in that, The lens assembly includes a lens barrel. An infrared incident end positioning step (D4) and an infrared incident end threaded retaining ring (D5) are coaxially arranged inside the incident end of the lens barrel. An infrared incident lens group (D1) is coaxially arranged between the infrared incident end positioning step (D4) and the infrared incident end threaded retaining ring (D5). The infrared incident end threaded retaining ring (D5) presses against the infrared incident lens group (D1) towards the infrared incident end positioning step (D4). An infrared exit end positioning step (D6) and an infrared exit end threaded retaining ring (D7) are coaxially arranged inside the exit end of the lens barrel. An infrared exit lens group (D2) is coaxially arranged between the infrared exit end positioning step (D6) and the infrared exit end threaded retaining ring (D7). The infrared exit end threaded retaining ring (D7) presses against the infrared exit lens group (D2) towards the infrared exit end positioning step (D6).

28. A four-channel polarization imaging system according to claim 27, characterized in that, The inner wall of the infrared incident end threaded pressure ring (D5) is provided with an infrared multi-level grating structure (D100), and the inner hole of the infrared incident end positioning step (D4) is provided with an infrared grating inclined surface (D200) that is inclined toward the central axis of the lens barrel; the inner wall of the infrared exit end threaded pressure ring (D7) is provided with an infrared multi-level grating structure (D100), and the inner hole of the infrared exit end positioning step (D6) is provided with an infrared grating inclined surface (D200) that is inclined toward the central axis of the lens barrel.

29. A four-channel polarization imaging system according to claim 28, characterized in that, The infrared multi-level grating structure (D100) includes several stepped holes coaxially arranged on the inner wall of the threaded pressure ring (D5) at the infrared incident end or the threaded pressure ring (D7) at the infrared exit end, and the diameter of the stepped holes decreases sequentially along the optical path direction.

30. A four-channel polarization imaging system according to claim 27, characterized in that, The infrared incident lens group (D1) includes an infrared incident concave-convex lens (D11), wherein the curvature of the incident convex surface and the exit concave surface of the infrared incident concave-convex lens (D11) are different; the infrared exit lens group (D2) includes an infrared exit concave-convex lens (D21) and an infrared exit biconvex lens (D22), wherein the infrared exit concave-convex lens (D21) is coaxially disposed between the infrared exit biconvex lens (D22) and the infrared incident lens group (D1), wherein the curvature of the incident convex surface and the exit concave surface of the infrared exit concave-convex lens (D21) are different, and the curvature of the incident convex surface and the exit convex surface of the infrared exit biconvex lens (D22) are different.

31. A four-channel polarization imaging system according to claim 30, characterized in that, An infrared spacer (D23) is coaxially arranged between the infrared emitting concave-convex lens (D21) and the infrared emitting biconvex lens (D22). One end of the infrared spacer (D23) is pressed against the infrared emitting concave-convex lens (D21) in the direction close to the threaded pressure ring (D7) of the infrared emitting end, and the other end of the infrared spacer (D23) is pressed against the infrared emitting biconvex lens (D22) in the direction close to the positioning step (D6) of the infrared emitting end. At least one infrared grating inclined surface (D200) inclined towards the central axis of the lens barrel is provided on the inner wall of the infrared spacer (D23).

Images