A dual-optical-path, wide-band, multispectral optical imaging system

Abstract

The present invention relates to a dual-optical path wide-band multispectral optical imaging system. By separating wide-band multispectral illumination and imaging into a visible light band imaging light path and a near-infrared band imaging light path, the spectral width of the visible light band imaging light path and the near-infrared band imaging light path are reduced, which also helps to reduce the difficulty of correcting chromatic aberration in the wide-band multispectral optical imaging system and obtain high-quality fundus multispectral images and color images. At the same time, the present application adopts polarization elimination reflection technology, which only requires the respective bands of visible light and near-infrared light to simultaneously obtain visible light band images and near-infrared band multispectral images, reducing the difficulty of eliminating stray light. The design scheme of the visible light band imaging light path and the near-infrared band imaging light path also makes the coating range of the lenses and polarization elimination reflection devices in the two optical paths narrower, simplifies the design, and improves the performance.

Description

Technical Field

[0001] The present invention relates to the technical field of wide-band optical imaging systems, and in particular to a dual-light-path wide-band multi-spectral optical imaging system. Background Art

[0002] Among existing new optical imaging technologies, multispectral imaging is widely used, especially in many biomedical diagnostic and industrial inspection methods, which require multiple narrow spectral bands of illumination light and multispectral images. Existing multispectral imaging of the human eye can be used for the diagnosis and treatment of ophthalmic diseases. It allows direct and non-invasive observation of blood vessels in the body, providing information about a patient's overall health and specific eye diseases. It can also be used to screen for systemic diseases such as diabetes and provide information about eye-specific diseases such as age-related macular degeneration and glaucoma, which are leading causes of blindness. Early detection of these changes is key for doctors to intervene and treat them promptly, effectively slowing or preventing further visual damage.

[0003] Existing multispectral optical imaging systems have a narrow target detection range. Fundus multispectral imaging, however, involves a wide range of visible and near-infrared wavelengths, leading to significant chromatic aberration in the system. This makes it difficult for images from different wavelengths to converge at the same location, resulting in suboptimal imaging. Furthermore, existing techniques employ wide-band coating on polarizers, a complex and costly process. Summary of the Invention

[0004] The technical problem to be solved by the present invention is how to overcome the chromatic aberration and unsatisfactory imaging effects caused by a wide wavelength range and synchronously obtain multispectral images of the visible light band and the near-infrared band.

[0005] The present invention provides a dual-light-path, wide-band, multi-spectral optical imaging system, comprising a common optical element, wherein the common optical element comprises an eyepiece objective lens group and a dichroic mirror sequentially arranged along the line of sight of a human eye, wherein the dichroic mirror is used to transmit near-infrared light and reflect visible light; and further comprising:

[0006] The visible light band imaging optical path is configured to collect visible light band images by polarization-eliminating reflections;

[0007] The near-infrared band imaging optical path is set to collect near-infrared band multispectral images by polarization elimination of reflections.

[0008] Compared with the existing technology, the present application has the following advantages: by separating wide-band multispectral illumination and imaging into visible light band imaging optical path and near-infrared band imaging optical path, the spectral width of the visible light band imaging optical path and the near-infrared band imaging optical path is reduced, which also helps to reduce the difficulty of correcting chromatic aberration in the wide-band multispectral optical imaging system and obtain high-quality fundus multispectral images and color images; at the same time, the present application adopts polarization elimination reflection technology, and only requires the respective bands of visible light and near-infrared light to simultaneously obtain visible light band images and near-infrared band multispectral images, reducing the difficulty of eliminating stray light. The design scheme of the visible light band imaging optical path and the near-infrared band imaging optical path also makes the coating range of the lenses and polarization elimination reflection devices in the two optical paths narrower, simplifies the design, and has better performance.

[0009] In a possible embodiment, the visible light band imaging optical path includes a visible light polarization splitter prism, a first linear polarizer, a second linear polarizer, a visible light imaging module and a visible light illumination module for reflecting visible light illumination light and transmitting visible light imaging light, and the visible light illumination module, the second linear polarizer, the visible light polarization splitter prism and the common optical element are arranged in sequence along the propagation path of the visible light illumination light, and at the same time, the common optical element, the visible light polarization splitter prism, the first linear polarizer and the visible light imaging module are arranged in sequence along the propagation path of the visible light imaging light; the visible light The illumination optical axis of the polarization beam splitter prism is arranged to coincide with the optical axes of the second linear polarizer and the visible light illumination module; the imaging optical axis of the visible light polarization beam splitter prism is arranged to coincide with the optical axes of the first linear polarizer and the visible light imaging module; the illumination optical axis and the imaging optical axis of the visible light polarization beam splitter prism are perpendicular to each other; multispectral fundus images of the human eye in the visible light band are obtained; at the same time, the visible light polarization beam splitter prism is combined with the first linear polarizer and the second linear polarizer to achieve polarization elimination of stray light in the visible light illumination light and the visible light imaging light, thereby improving imaging quality and reducing the frame rate requirement of the visible light imaging module.

[0010] In a possible implementation, the visible light imaging module includes a visible light detector and a visible light imaging lens assembly, and the visible light imaging lens assembly is located between the visible light detector and the first linear polarizer.

[0011] In one possible embodiment, the visible light illumination module includes a visible light illumination light source and a visible light illumination lens group, wherein the visible light illumination lens group is arranged between the visible light illumination light source and the second linear polarizer; when the visible light illumination light source emits wide-band LED white light, the visible light detector is a visible light color camera; when the visible light illumination light source emits a monochromatic light source within the visible light range, the visible light detector is a visible light black and white camera; combining the wide-band LED white light with the visible light color camera can obtain clear fundus color images; combining the monochromatic light source within the visible light range with the visible light black and white camera can obtain high-quality multispectral fundus black and white images.

[0012] In a possible embodiment, the near-infrared band imaging light path includes a near-infrared polarizing beam splitter prism, a third linear polarizer, a fourth linear polarizer, a near-infrared imaging module and a near-infrared illumination module for reflecting near-infrared illumination light and transmitting near-infrared imaging light. The near-infrared illumination module, the fourth linear polarizer, the near-infrared polarizing beam splitter prism and the common optical element are arranged in sequence along the propagation path of the near-infrared illumination light. At the same time, the common optical element, the near-infrared polarizing beam splitter prism, the third linear polarizer and the near-infrared imaging module are arranged in sequence along the propagation path of the near-infrared imaging light. The near-infrared polarizer The illumination optical axis of the polarization beam splitter prism is arranged to coincide with the optical axes of the fourth linear polarizer and the near-infrared illumination module, and the imaging optical axis of the near-infrared polarization beam splitter prism is arranged to coincide with the optical axes of the third linear polarizer and the near-infrared imaging module. The imaging optical axis of the near-infrared polarization beam splitter prism and the illumination optical axis are perpendicular to each other, so as to obtain a near-infrared multispectral fundus image of the human eye in the near-infrared band; at the same time, the near-infrared polarization beam splitter prism is combined with the third linear polarizer and the fourth linear polarizer to achieve polarization elimination of stray light in the near-infrared illumination light and the near-infrared imaging light, thereby improving imaging quality and reducing the frame rate requirement of the near-infrared imaging module.

[0013] In a possible implementation, the illumination optical axis of the visible light polarization beam splitter prism is parallel to the imaging optical axis of the near-infrared polarization beam splitter prism, and the imaging optical axis of the visible light polarization beam splitter prism is parallel to the illumination optical axis of the near-infrared polarization beam splitter prism.

[0014] In a possible implementation, the dichroic mirror is a long-pass dichroic mirror, thereby having the effects of high reflectivity at short wavelengths and high transmittance at long wavelengths.

[0015] In one possible embodiment, the near-infrared imaging module includes a near-infrared imaging lens group and a near-infrared imaging detector, and the near-infrared imaging lens group is arranged between the near-infrared imaging detector and the third linear polarizer; the near-infrared lighting module includes a near-infrared lighting light source and a near-infrared lighting lens group, and the near-infrared lighting lens group is arranged between the near-infrared lighting light source and the fourth linear polarizer.

[0016] In one possible embodiment, a linkage focusing mechanism is further included, which is connected to the near-infrared imaging lens group and the visible light imaging lens group, and is used to adjust the near-infrared imaging lens group and the visible light imaging lens group for synchronous focusing, thereby ensuring that when the near-infrared band imaging light path is focused, the visible light band imaging light path is focused on the fundus of the human eye; thereby ensuring that the two light paths are focused at the same time, without adding a light source for focusing to the visible light band imaging light path, thereby reducing the number of focusing times.

[0017] In a possible implementation, the first linear polarizer and the third linear polarizer are adjusted to pass only P-polarized light during imaging, and the second linear polarizer and the fourth linear polarizer are adjusted to pass only S-polarized light during imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the system structure of Example 1 of the present invention;

[0019] Figure 2 This is a schematic diagram of the system structure of Example 2 of the present invention.

[0020] Description of reference numerals:

[0021] 1. Common optical elements; 1-1. Eyepiece objective lens group; 1-2. Dichroic mirror; 2. Visible light polarizing beam splitter; 3. First linear polarizer; 4. Second linear polarizer; 5. Visible light imaging module; 5-1. Visible light imaging lens group; 5-2. Visible light detector; 6. Visible light illumination module; 6-1. Visible light illumination light source; 6-2. Visible light illumination lens group; 7. Near-infrared polarizing beam splitter; 8. Third linear polarizer; 9. Fourth linear polarizer; 10. Near-infrared imaging module; 10-1. Near-infrared imaging lens group; 10-2. Near-infrared imaging detector; 11. Near-infrared illumination module; 11-1. Near-infrared illumination light source; 11-2. Near-infrared illumination lens group; 12. Illumination fiber; 13. Linked focusing mechanism. DETAILED DESCRIPTION

[0022] First, those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the embodiments of the present application and are not intended to limit the scope of protection of the embodiments of the present application. Those skilled in the art may adjust them as needed to suit specific application scenarios.

[0023] In the description of the embodiments of this application, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of this application based on the specific circumstances.

[0024] In the embodiments of the present application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0025] Traditional fundus color photography only captures images covering the visible light range, which has a narrow wavelength range. Multispectral fundus cameras, on the other hand, capture images covering both visible and near-infrared wavelengths, a wider wavelength range. This inevitably leads to significant chromatic aberration in the system, making it difficult for images from different wavelengths to converge at the same location, resulting in suboptimal imaging. Correcting chromatic aberration is difficult and costly. Furthermore, the polarization-eliminating reflective coating required for traditional wide-band multispectral image acquisition requires a large coating area, resulting in a complex and costly coating process.

[0026] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Example 1

[0028] See also Figure 1 The present invention discloses a dual-optical-path, wide-band, multi-spectral optical imaging system.

[0029] A dual-light-path, wide-band, multi-spectral optical imaging system comprises a common optical element 1, wherein the common optical element 1 comprises an eyepiece objective lens group 1-1 and a dichroic mirror 1-2, which are sequentially arranged along the line of sight of a human eye. The eyepiece objective lens group 1-1 is composed of one or more spherical or aspherical lenses to achieve an imaging function. The dichroic mirror 1-2 is used to transmit near-infrared light, reflect visible light, and reduce energy loss. The dichroic mirror 1-2 is a long-pass dichroic mirror. To this end, the angle of incidence (AOI) of the dichroic mirror 1-2 is 45°. This allows the optical path of the dual-light-path, wide-band, multi-spectral optical imaging system to be compactly folded, facilitates alignment of the dichroic mirror 1-2 with other optical elements, simplifies manufacturing and debugging, and simplifies calculation and design. In this embodiment, the dichroic mirror 1-2 has a central wavelength of 780 nm, and light sources with wavelengths below 780 nm are reflected, while light sources with wavelengths above 780 nm are transmitted.

[0030] The dual-light-path, wide-band, multi-spectral optical imaging system further includes a visible light band imaging light path, a near-infrared band imaging light path, and a linkage focusing mechanism 13, wherein:

[0031] The visible light band imaging optical path is configured to collect visible light band images by polarization-eliminating reflections; specifically, it includes:

[0032] The visible light band imaging optical path includes a visible light polarization beam splitter prism 2 for reflecting visible light illumination light and transmitting visible light imaging light, a first linear polarizer 3, a second linear polarizer 4, a visible light imaging module 5, and a visible light illumination module 6. In this embodiment, the visible light polarization beam splitter prism 2 uses a visible light band anti-reflection film. The visible light illumination light generated by the visible light illumination module 6, upon reaching the pupil of the human eye, propagates through the human eye, illuminates the fundus area, and is reflected to form visible light imaging light.

[0033] In order to eliminate stray light in the visible light illumination light and the visible light imaging light and improve the imaging quality, the visible light illumination module 6, the second linear polarizer 4, the visible light polarization beam splitter prism 2, and the common optical element 1 are arranged in sequence along the propagation path of the visible light illumination light. At the same time, the common optical element 1, the visible light polarization beam splitter prism 2, the first linear polarizer 3, and the visible light imaging module 5 are arranged in sequence along the propagation path of the visible light imaging light; the illumination optical axis of the visible light polarization beam splitter prism 2 is arranged to coincide with the optical axis of the second linear polarizer 4 and the visible light illumination module 6; the imaging optical axis of the visible light polarization beam splitter prism 2 is arranged to coincide with the optical axis of the first linear polarizer 3 and the visible light imaging module 5; the illumination optical axis and the imaging optical axis of the visible light polarization beam splitter prism 2 are perpendicular to each other; thereby obtaining a multispectral fundus image of the human eye in the visible light band; at the same time, the frame rate requirement of the visible light imaging module 5 is also reduced;

[0034] The visible light imaging module 5 includes a visible light detector 5-2 and a visible light imaging lens group 5-1. The visible light imaging lens group 5-1 is located between the visible light detector 5-2 and the first linear polarizer 3. The optical axes of the first linear polarizer 3 and the visible light imaging lens group 5-1 are arranged to coincide with each other. In this embodiment, the visible light illumination module 6 includes a visible light illumination source 6-1 and a visible light illumination lens group 6-2. The visible light illumination source 6-1 emits wide-band LED white light. The corresponding visible light detector 5-2 is a visible light color camera. In addition, the first linear polarizer 3 is adjusted to pass only P-polarized light during imaging, and the second linear polarizer 4 is adjusted to pass only S-polarized light during imaging.

[0035] The near-infrared band imaging optical path is configured to collect near-infrared band multispectral images by polarization elimination of reflection, specifically including:

[0036] The near-infrared band imaging optical path includes a near-infrared polarizing beam splitter 7 for reflecting near-infrared illumination light and transmitting near-infrared imaging light, a third linear polarizer 8, a fourth linear polarizer 9, a near-infrared imaging module 10, and a near-infrared illumination module 11. In this embodiment, the near-infrared polarizing beam splitter 7 uses a near-infrared band anti-reflection film. The near-infrared illumination light generated by the near-infrared illumination module 11 reaches the pupil of the human eye, propagates through the human eye, illuminates the fundus area, and is reflected to form near-infrared imaging light.

[0037] In order to eliminate stray light in the near-infrared illumination light and the near-infrared imaging light and improve the imaging quality, the near-infrared illumination module 11, the fourth linear polarizer 9, the near-infrared polarizing beam splitter prism 7, and the common optical element 1 are arranged in sequence along the propagation path of the near-infrared illumination light. At the same time, the common optical element 1, the near-infrared polarizing beam splitter prism 7, the third linear polarizer 8, and the near-infrared imaging module 10 are arranged in sequence along the propagation path of the near-infrared imaging light; the illumination optical axis of the near-infrared polarizing beam splitter prism 7 coincides with the optical axis of the fourth linear polarizer 9 and the near-infrared illumination module 11, and the imaging optical axis of the near-infrared polarizing beam splitter prism 7 coincides with the optical axis of the third linear polarizer 8 and the near-infrared imaging module 10. The optical axes of the imaging module 10 are arranged to coincide with each other, and the imaging optical axis of the near-infrared polarizing beam splitter prism 7 is perpendicular to the illumination optical axis, thereby obtaining a near-infrared multispectral fundus image of the human eye in the near-infrared band; at the same time, the near-infrared polarizing beam splitter prism 7 is combined with the third linear polarizer 8 and the fourth linear polarizer 9 to achieve polarization elimination of stray light in the near-infrared illumination light and the near-infrared imaging light, thereby improving the imaging quality and reducing the frame rate requirement of the near-infrared imaging module; at the same time, the illumination optical axis of the visible light polarizing beam splitter prism 2 is parallel to the imaging optical axis of the near-infrared polarizing beam splitter prism 7, and the imaging optical axis of the visible light polarizing beam splitter prism 2 is parallel to the illumination optical axis of the near-infrared polarizing beam splitter prism 7.

[0038] The near-infrared imaging module 10 includes a near-infrared imaging lens group 10-1 and a near-infrared imaging detector 10-2. The near-infrared imaging lens group 10-1 is arranged between the near-infrared imaging detector 10-2 and the third linear polarizer 8. The third linear polarizer 8 is arranged to coincide with the optical axis of the near-infrared imaging lens group 10-1. The near-infrared lighting module 11 includes a near-infrared lighting source 11-1 and a near-infrared lighting lens group 11-2. The near-infrared lighting source 11-1 in this embodiment includes an LED light source lamp with wavelengths of 780nm, 840nm, and 880nm. An illumination fiber 12 is provided on the top, and a ring light source is obtained by coupling the illumination fiber 12. The illumination fiber 12 is an optical fiber bundle composed of multiple optical fibers, the input end face of which is circular or square, and the output end face is ring-shaped. The illumination fiber 12 can achieve a uniform light effect without the need for a complex optical path, and the cost is low. The light sources of each band will not cause uneven light intensity distribution due to different positions, and the stray light of the human cornea is eliminated. At the same time, the use of the illumination fiber 12 can reduce the size of the light source, so that the size of the subsequent illumination light path is reduced, and the cost is reduced. In addition, the beam shaping is simple, and the illumination fiber 12 at the ring output port obtains a ring light spot, which is low in cost.

[0039] Meanwhile, the third linear polarizing plate 8 is adjusted to a state of passing only P-polarized light during imaging, and the fourth linear polarizing plate 9 is adjusted to a state of passing only S-polarized light during imaging.

[0040] In addition, since the focusing relies on a near-infrared light source, the human eye is not sensitive to the near-infrared light source and the pupil will not contract due to stimulation, so the focusing relies on the near-infrared light source. The linkage focusing mechanism 13 is connected to the near-infrared imaging lens group 10-1 and the visible light imaging lens group 5-1, and is used to adjust the near-infrared imaging lens group 10-1 and the visible light imaging lens group 5-1 for synchronous focusing, so that when the near-infrared band imaging light path is focused, the visible light band imaging light path is focused on the fundus of the human eye, thereby ensuring that the two light paths are focused at the same time, reducing the number of focusing times.

[0041] The entire principle of the visible light band imaging optical path is as follows:

[0042] The visible light illumination lens group is arranged between the visible light illumination source 6-1 and the second linear polarizer 4, and is used to output the visible light output by the visible light illumination source 6-1. After being transmitted through the second linear polarizer 4, the visible light is sequentially reflected by the visible light polarization splitter prism 2 and transmitted by the dichroic mirror 1-2. After passing through the eyepiece objective lens group 1-1, an annular light spot is formed at the pupil of the human eye. After propagating inside the human eye, the fundus area is illuminated and reflected. The eyepiece objective lens group 1-1 receives the fundus visible light reflection image, and after being reflected by the dichroic mirror 1-2 and transmitted by the first linear polarizer 3, it is imaged on the visible light color camera through the visible light imaging lens group 5-1, thereby obtaining a fundus color image.

[0043] The imaging principle of the near-infrared band imaging optical path is as follows:

[0044] The near-infrared illumination lens group 11-2 collects the near-infrared light output by the near-infrared illumination light source 11-1, and after being sequentially transmitted through the fourth linear polarizer 9, reflected by the near-infrared polarizing beam splitter prism 7, and transmitted by the dichroic mirror 1-2, the light then passes through the eyepiece objective lens group 1-1 to form an annular light spot at the pupil of the human eye. After propagating inside the human eye, the light illuminates the fundus area and is reflected. Then, the eyepiece objective lens group 1-1 receives the near-infrared reflected image of the fundus, and after being transmitted through the dichroic mirror 1-2 and the third linear polarizer 8, the light is imaged on the near-infrared imaging detector through the near-infrared imaging lens group 10-1 to obtain a multispectral black-and-white image of the fundus.

[0045] The operating method of the dual-optical-path, wide-band, multi-spectral optical imaging system of this embodiment includes:

[0046] Step 1: Turn on the near-infrared illumination module 11 and the visible light detector 5-2, and adjust the optical system so that it is aligned with the pupil of the human eye, while ensuring that the distance between the front surface of the eyepiece lens group 1-1 and the ocular surface of the human eye is constant;

[0047] Step 2: Use the linkage focusing mechanism 13 to simultaneously adjust the near-infrared imaging lens assembly 10-1 and the visible light imaging lens assembly 5-1 to achieve focusing;

[0048] Step 3: Turn on the visible light illumination source 6-1, the near-infrared illumination source 11-1, the visible light detector 5-2 and the near-infrared imaging detector in sequence;

[0049] Step 4: Expose the near-infrared illumination source 11-1 and the visible light illumination source 6-1 in sequence, collect data through the near-infrared imaging detector 10-2 and the visible light detector 5-2, and obtain a multispectral black-and-white fundus image and a fundus color image.

[0050] Example 2

[0051] The difference between Example 2 of the present application and Example 1 is that the visible light illumination source 6-1 is an LED light source lamp including 550nm, 600nm, and 660nm bands, and the visible light illumination source 6-1 is provided with an illumination optical fiber 12. Accordingly, the visible light detector 5-2 is a visible light black and white camera with a CCD or CMOS black and white monochrome sensor, which is used to capture multispectral fundus images; the near-infrared light source is an LED light source lamp including 740nm, 780nm, and 830nm bands. The visible light band imaging optical path of this embodiment obtains a visible light band multispectral black and white image of the fundus, and the near-infrared band multispectral black and white image of the fundus is obtained through the near-infrared band imaging optical path.

[0052] The operating method of the dual-optical-path, wide-band, multi-spectral optical imaging system of this embodiment includes:

[0053] Step 1: Turn on the near-infrared illumination source 11-1 and the visible light detector 5-2, and adjust the optical system so that it is aligned with the pupil of the human eye, while ensuring that the distance from the front surface of the eyepiece objective lens group to the ocular surface of the human eye is constant.

[0054] Step 2: Utilize the linkage focusing mechanism 13 to simultaneously adjust the near-infrared imaging lens assembly 10 - 1 and the visible light imaging lens assembly 5 - 1 to achieve focusing.

[0055] Step 3: Turn on the visible light illumination source 6-1 and the near-infrared imaging detector 10-2 in sequence.

[0056] Step 4: sequentially expose the near-infrared illumination source 11-1 and the visible light illumination source 6-1, collect data through the near-infrared imaging detector and the visible light detector 5-2, and obtain a wide-band multispectral black-and-white fundus image.

[0057] In the above two embodiments, wide-band fundus multispectral imaging is achieved by separating the visible light band imaging optical path and the near-infrared band imaging optical path; and simultaneous acquisition of near-infrared multispectral images and visible light multispectral images is achieved through a synchronous focusing mechanism, thereby reducing image acquisition time and lowering the frame rate requirements of the visible light detector 5-2 and the near-infrared imaging detector 10-2.

[0058] The dual-light path solution of this application makes the coating range of the two light path lenses and the polarization anti-reflection device narrower, simplifies the design, and improves the performance, requiring only the respective wavelength bands of visible light and near-infrared light.

[0059] In the description of the embodiments of the present application, it should be noted that in the description of the present application, terms such as "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present application.

[0060] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "in the present embodiment", "specific example", or "some examples" means that the specific features, mechanisms, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0061] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A dual-optical-path, wide-band, multi-spectral optical imaging system, characterized in that: The invention comprises a common optical element (1), wherein the common optical element (1) comprises an eyepiece objective lens group (1-1) and a dichroic mirror (1-2) arranged in sequence along the direction of the human eye's line of sight, wherein the dichroic mirror (1-2) is used for transmitting near-infrared light and reflecting visible light; and further comprises: A visible light band imaging optical path is configured to collect visible light band images by polarization elimination of reflections; the visible light band imaging optical path comprises a visible light polarization beam splitter prism (2), a first linear polarizer (3), a second linear polarizer (4), a visible light imaging module (5), and a visible light illumination module (6) for reflecting visible light illumination light and transmitting visible light imaging light; the visible light illumination module (6), the second linear polarizer (4), the visible light polarization beam splitter prism (2), and a common optical element (1) are sequentially arranged along the propagation path of the visible light illumination light; and at the same time, the common optical element (1), the visible light polarization beam splitter prism (2), the first linear polarizer (3), and the visible light imaging module (5) are sequentially arranged along the propagation path of the visible light imaging light; the illumination optical axis and the imaging optical axis of the visible light polarization beam splitter prism (2) are perpendicular to each other; A near-infrared band imaging optical path is configured to collect near-infrared band multispectral images by polarization elimination of reflection; the near-infrared band imaging optical path comprises a near-infrared polarization beam splitter prism (7), a third linear polarizer (8), a fourth linear polarizer (9), a near-infrared imaging module (10), and a near-infrared illumination module (11) for reflecting near-infrared illumination light and transmitting near-infrared imaging light; the near-infrared illumination module (11), the fourth linear polarizer (9), the near-infrared polarization beam splitter prism (7), and a common optical element (1) are sequentially arranged along the propagation path of the near-infrared illumination light; and at the same time, the common optical element (1), the near-infrared polarization beam splitter prism (7), the third linear polarizer (8), and the near-infrared imaging module (10) are sequentially arranged along the propagation path of the near-infrared imaging light; the imaging optical axis of the near-infrared polarization beam splitter prism (7) and the illumination optical axis are perpendicular to each other; The first linear polarizing plate (3) and the third linear polarizing plate (8) are adjusted to a state of only passing P-polarized light during imaging, and the second linear polarizing plate (4) and the fourth linear polarizing plate (9) are adjusted to a state of only passing S-polarized light during imaging.

2. The dual-optical-path, wide-band, multi-spectral optical imaging system according to claim 1, characterized in that: The illumination optical axis of the visible light polarization beam splitter (2) is arranged to coincide with the optical axis of the second linear polarizer (4) and the visible light illumination module (6); and the imaging optical axis of the visible light polarization beam splitter (2) is arranged to coincide with the optical axis of the first linear polarizer (3) and the visible light imaging module (5).

3. The dual-light-path, wide-band, multi-spectral optical imaging system according to claim 2, characterized in that: The visible light imaging module (5) comprises a visible light detector (5-2) and a visible light imaging lens group (5-1), wherein the visible light imaging lens group (5-1) is located between the visible light detector (5-2) and the first linear polarizer (3).

4. The dual-optical-path, wide-band, multi-spectral optical imaging system according to claim 3, characterized in that: The visible light illumination module (6) comprises a visible light illumination light source (6-1) and a visible light illumination lens group (6-2), wherein the visible light illumination lens group (6-2) is arranged between the visible light illumination light source (6-1) and a second linear polarizer (4); when the visible light illumination light source (6-1) emits wide-band LED white light, the visible light detector (5-2) is a visible light color camera; when the visible light illumination light source (6-1) emits a monochromatic light source within the visible light range, the visible light detector (5-2) is a visible light black-and-white camera.

5. The dual-optical-path, wide-band, multi-spectral optical imaging system according to claim 4, characterized in that: The illumination optical axis of the near-infrared polarizing beam splitter prism (7) is arranged to coincide with the optical axis of the fourth linear polarizing plate (9) and the near-infrared illumination module (11); and the imaging optical axis of the near-infrared polarizing beam splitter prism (7) is arranged to coincide with the optical axis of the third linear polarizing plate (8) and the near-infrared imaging module.

6. The dual-optical-path, wide-band, multi-spectral optical imaging system according to claim 5, characterized in that: The illumination optical axis of the visible light polarization beam splitting prism (2) is parallel to the imaging optical axis of the near-infrared polarization beam splitting prism (7), and the imaging optical axis of the visible light polarization beam splitting prism (2) is parallel to the illumination optical axis of the near-infrared polarization beam splitting prism (7).

7. The dual-light-path, wide-band, multi-spectral optical imaging system according to claim 1 or 6, characterized in that: The dichroic mirror (1-2) is a long-pass dichroic mirror.

8. The dual-light-path, wide-band, multi-spectral optical imaging system according to claim 6, characterized in that: The near-infrared imaging module (10) comprises a near-infrared imaging lens group (10-1) and a near-infrared imaging detector (10-2), wherein the near-infrared imaging lens group (10-1) is arranged between the near-infrared imaging detector (10-2) and a third linear polarizer (8); and the near-infrared lighting module (11) comprises a near-infrared lighting light source (11-1) and a near-infrared lighting lens group (11-2), wherein the near-infrared lighting lens group (11-2) is arranged between the near-infrared lighting light source (11-1) and a fourth linear polarizer (9).

9. The dual-light-path, wide-band, multi-spectral optical imaging system according to claim 8, characterized in that: The invention also includes a linkage focusing mechanism (13), which is connected to the near-infrared imaging lens group (10-1) and the visible light imaging lens group (5-1) and is used to adjust the near-infrared imaging lens group (10-1) and the visible light imaging lens group (5-1) to perform synchronous focusing.

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