Beam splitting prism structure, endoscope and endoscope system

Abstract

The invention provides a beam splitter prism structure, an endoscope and an endoscope system. The beam splitter prism structure comprises a first beam splitter prism and a prism group which are sequentially arranged along an optical axis, a first light-emitting surface of the first beam splitter prism is provided with a first light filter; a second light incident surface of a second beam splitter prism in the prism group and a first beam splitting surface of the first beam splitter prism are arranged in parallel and at an interval; the second light emitting surface of the prism group is provided with a second optical filter, and at least one of the first optical filter and the second optical filter intersects with the optical axis of the corresponding target reflection optical axis but is not perpendicular to the optical axis of the target reflection optical axis. When the beam splitter prism is used for imaging of the imaging module, by means of the arrangement, the propagation direction of stray light is changed, the area outside the imaging surface of the imaging module irradiated by the stray light is reduced, the probability that the stray light and a ghost image appear on the corresponding imaging surface is reduced, and therefore the imaging quality of the imaging module is indirectly improved.

Description

Technical Field

[0001] This application relates to the field of endoscopic imaging technology, and in particular to a beam splitter prism structure, an endoscope, and an endoscopic system. Background Technology

[0002] An electronic endoscope, or simply endoscope, is an instrument that can be inserted into the human body, allowing doctors to directly observe the tissue morphology and lesions of the body cavities and internal organs, and to make accurate diagnoses of diseases. Currently, endoscopes are widely used in various fields of clinical medicine, and play an irreplaceable role, especially in diagnosing intrauterine diseases.

[0003] In related technologies, the photosensitive element in the endoscope obtains the gray value of the corresponding band of each pixel by setting a color filter array. However, each pixel can only receive one of the three bands of red, green and blue (RGB). Then, the gray values ​​of the other two bands of each pixel are obtained by interpolation of the read gray values, and a color image is generated. However, this method filters out the light of the other two colors, which can easily cause ghosting and shadows on the imaging surface of the photosensitive element. Summary of the Invention

[0004] Embodiments of this application provide a beam splitter prism structure, an endoscope, and an endoscope system to solve the problem of ghosting and shadows easily appearing on the imaging surface of endoscopes in related technologies.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0006] In a first aspect, embodiments of this application provide a beam-splitting prism structure for use in an endoscope. The beam-splitting prism structure includes: a first beam-splitting prism and a prism group arranged sequentially along the principal optical axis; the first beam-splitting prism includes a first incident surface, a first beam-splitting surface, a first reflecting surface, and a first emitting surface, the first emitting surface being provided with a first filter, and the side of the first filter (12) away from the first emitting surface being used to set a first photosensitive element; the prism group includes a second beam-splitting prism, the second beam-splitting prism including a second incident surface, a second reflecting surface, and a second emitting surface; the second incident surface is parallel to and spaced apart from the first beam-splitting surface, so that the first light incident on the first beam-splitting prism after passing through the first incident surface and entering the first beam-splitting prism is sequentially split by the first beam-splitting surface and reflected by the first reflecting surface. The second light emitted from the first light-emitting surface passes sequentially through the first light-splitting surface and the second light-incident surface into the prism group, and is then reflected by the second reflective surface before emitting from the second light-emitting surface. The second light is the light ray split by the first light-splitting surface. The second light-emitting surface is provided with a second filter, at least one of the first filter and the second filter intersects but is not perpendicular to the corresponding target reflection optical axis. The side of the second filter away from the second light-emitting surface is used to set a second photosensitive element. The target reflection optical axis is the optical axis of the light ray emitted from the target light-emitting surface, the target light-emitting surface includes the first light-emitting surface and the second light-emitting surface, and the principal optical axis is the optical axis of the first light.

[0007] In some possible implementations, the second beam splitter further includes a second beam-splitting surface; the prism group further includes a third beam splitter; the third beam splitter is disposed on the side of the second beam splitter away from the first beam splitter; the third beam splitter includes a third incident surface and a third exiting surface; the third incident surface is parallel to and spaced from the second beam splitter, so that the second light incident on the second beam splitter, after being split by the second beam splitter and reflected by the second reflecting surface, exits from the second exiting surface, and the third light incident on the second beam splitter, after being split by the second beam splitter and reflected by the second reflecting surface, enters the third beam splitter and exits from the second exiting surface, and the third light incident on the second beam splitter, after being split by the second beam splitter and the third incident surface, enters the third beam splitter and exits from the second exiting surface. The light is emitted from a third light-emitting surface; the third light is the light ray split by the second light-emitting surface; the target light-emitting surface further includes a third light-emitting surface, the target reflected optical axis includes a first reflected optical axis in the first beam splitter, a second reflected optical axis in the second beam splitter, and a third reflected optical axis in the third beam splitter; the thickness direction of the first filter intersects with but is not perpendicular to the direction of the first reflected optical axis, and the thickness direction of the second filter intersects with but is not perpendicular to the direction of the second reflected optical axis; and / or; the third light-emitting surface is provided with a third filter, and the thickness direction of the third filter intersects with but is not perpendicular to the corresponding third reflected optical axis.

[0008] In some feasible embodiments, the second beam splitter further includes a second beam-splitting surface; the prism group further includes a third beam splitter and a fourth beam splitter, the fourth beam splitter being disposed between the third beam splitter and the second beam splitter; the third beam splitter includes a third incident surface, a third beam-splitting surface, and a third exit surface, the third beam-splitting surface and the third incident surface being located on the same plane; the fourth beam splitter includes a fourth incident surface, a fourth reflecting surface, and a fourth exit surface, the fourth reflecting surface being parallel to and spaced apart from the third beam splitter, the fourth incident surface being parallel to and spaced apart from the second beam splitter, so that the third light after being split by the second beam splitter is incident on the beam splitter and, after being split by the third beam splitter, a portion of the third light is reflected by the fourth reflecting surface and exits from the fourth exit surface; the other portion of the third light... The light passes sequentially through the third beam-splitting surface, the third light-incident surface, and the third light-exiting surface before exiting the third beam-splitting prism; the third light is the light ray split by the second light through the second beam-splitting surface; the target light-exiting surface further includes a third light-exiting surface and a fourth light-exiting surface; the target reflected optical axis includes a first reflected optical axis in the first beam-splitting prism, a second reflected optical axis in the second beam-splitting prism, a third reflected optical axis in the third beam-splitting prism, and a fourth reflected optical axis in the fourth beam-splitting prism; the thickness direction of the first filter intersects with but is not perpendicular to the direction of the first reflected optical axis, and the thickness direction of the second filter intersects with but is not perpendicular to the direction of the second reflected optical axis; and / or; the fourth light-exiting surface is provided with a fourth filter, and the thickness direction of the fourth filter intersects with but is not perpendicular to the corresponding fourth reflected optical axis.

[0009] In some feasible ways, the first reflective optical axis, the second reflective optical axis, and the third reflective optical axis are located in the same plane.

[0010] In some feasible embodiments, the fourth beam splitter has a pyramidal structure, and the prism group further includes an optical prism located between the fourth beam splitter and the second beam splitter, wherein two adjacent surfaces of the optical prism and the fourth beam splitter are parallel but spaced apart.

[0011] In some possible implementations, the first filter includes a first glass and a first filter layer disposed on the first glass, a first surface and a second surface of the first glass facing each other along its thickness direction, the first surface being parallel to the first light-emitting surface, the second surface being perpendicular to the first reflected optical axis, and the first surface intersecting the optical axis; and / or; the second filter includes a second glass and a second filter layer disposed on the second glass, a third surface and a fourth surface of the second glass facing each other along its thickness direction, the third surface being parallel to the second light-emitting surface, the fourth surface being perpendicular to the second reflected optical axis, and the third surface intersecting the second reflected optical axis.

[0012] In some possible implementations, the first surface is inclined relative to the second surface.

[0013] In some possible implementations, the third surface is inclined relative to the fourth surface.

[0014] In some possible implementations, the acute angle formed between the thickness direction of the first filter and the direction of the first reflected optical axis is a first included angle, which is 5° to 10°; and / or, the acute angle formed between the thickness direction of the second filter and the direction of the second reflected optical axis is a second included angle, which is 5° to 10°.

[0015] In some possible implementations, the first beam-splitting surface includes a beam-splitting region located near the first reflected optical axis and a light-absorbing region located away from the first reflected optical axis, the beam-splitting region being used to separate the first light and the second light, and the light-absorbing region being used to absorb light.

[0016] In some feasible embodiments, the first filter is bonded to the first light-emitting surface, and the second filter is bonded to the second light-emitting surface.

[0017] In some possible implementations, the first reflective surface is connected between the first incident surface and the first emitting surface, and the first reflective surface is at least partially located on the same plane as the first incident surface.

[0018] In some feasible embodiments, the non-light-transmitting surface of the beam-splitting prism structure is provided with a light-absorbing layer; and / or, the non-light-transmitting surface of the beam-splitting prism structure is provided with a groove.

[0019] Secondly, embodiments of this application also provide an endoscope, including the beam-splitting prism structure described in the first aspect above.

[0020] Thirdly, embodiments of this application also provide an endoscope system, including a light source host, an image processing device, and the endoscope described in the second aspect above.

[0021] The beneficial effect of the beam splitter structure provided in this application embodiment is that by having at least one of the first filter disposed on the first light-emitting surface of the first beam splitter and the second filter disposed on the second light-emitting surface of the prism group intersect but not perpendicular to the optical axis of the corresponding target reflection optical axis, when stray light passes through the beam splitter structure, the propagation direction of stray light other than the first light can be changed by the above arrangement, so that the stray light propagates in a direction away from the corresponding target reflection optical axis. When the beam splitter is used for endoscope imaging, the area of ​​stray light irradiating the imaging surface of the corresponding photosensitive element is reduced. That is, the image formation of stray light on the corresponding photosensitive element is reduced, and the probability of stray light and ghost images appearing on the imaging surface of the corresponding photosensitive element is reduced, thereby indirectly improving the imaging quality of the endoscope. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 Structural diagrams of beam-splitting prism structures provided in some embodiments of this application; Figure 2 for Figure 1 A structural diagram of the beam-splitting prism structure from one viewpoint; Figure 3 for Figure 1 A structural diagram of the beam-splitting prism structure from another perspective; Figure 4 Structural diagrams of beam-splitting prism structures provided in other embodiments of this application with grooves; Figure 5 Structural diagrams of beam-splitting prism structures provided in other embodiments of this application that do not have grooves; Figure 6 for Figure 5 A structural diagram of the beam-splitting prism structure from one viewpoint; Figure 7 for Figure 5 The structure of the beam-splitting prism in the image is shown from another perspective.

[0024] The following are the labeling elements in the figure: 10. First beam-splitting surface; 20. Second beam-splitting surface; 30. Third beam-splitting surface; 40. Groove; 11. First beam splitter; 12. First filter; 21. Second beam splitter; 22. Second filter; 31. Third beam splitter; 32. Third filter; 41. Fourth beam splitter; 42. Fourth filter; 51. Optical prism. Detailed Implementation

[0025] For ease of understanding, the English abbreviations and related technical terms used in the embodiments of this application will be explained and described below.

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more, unless otherwise explicitly specified.

[0028] An electronic endoscope, or simply endoscope, is an instrument that can be inserted into the human body, allowing doctors to directly observe the tissue morphology and changes in lesions of the body cavities and internal organs, and to make accurate diagnoses of diseases. Currently, endoscopes are widely used in various fields of clinical medicine, and play an irreplaceable role, especially in the diagnosis of intrauterine diseases.

[0029] In related technologies, the photosensitive element in the endoscope obtains the gray value of the corresponding band of each pixel by setting a color filter array. However, each pixel can only receive one of the three bands of red, green and blue (RGB). Then, the gray values ​​of the other two bands of each pixel are obtained by interpolation of the read gray values, and a color image is generated. However, this method filters out the light of the other two colors, which can easily cause ghosting and shadows on the imaging surface of the photosensitive element, thus reducing the image quality.

[0030] To address the aforementioned technical problems, this application provides a beam splitter structure and an imaging module. The imaging module includes an optical lens and a photosensitive element group. The optical lens is disposed on one side of the light-incident surface of the beam splitter structure, and the photosensitive element group is disposed on the light-outceasing side of the beam splitter structure. The beam splitter structure is located between the optical lens and the photosensitive element group.

[0031] The aforementioned imaging module can be applied to, but is not limited to, endoscopes.

[0032] The aforementioned beam splitter structure is used for beam splitting. Therefore, the aforementioned photosensitive element group includes two or more photosensitive elements. The specific number of photosensitive elements corresponds to the number of beams split by the beam splitter structure. That is, a photosensitive element needs to be set on each light-emitting surface of the beam splitter structure so that the light emitted from each light-emitting surface is imaged on the imaging surface of the corresponding photosensitive element.

[0033] The working principle of the aforementioned optical lens is as follows: light reflected from the subject passes through the optical lens to generate an optical image, which is projected onto the imaging surface of the photosensitive element. The photosensitive element converts the optical image into an electrical signal, i.e., an analog image signal, and transmits it to the processor. The photosensitive element (also called an image sensor) is a semiconductor chip containing hundreds of thousands to millions of photodiodes on its surface. When illuminated by light, these photodiodes generate electrical charges. The photosensitive element can be a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) device. A CCD is made of a highly sensitive semiconductor material that converts light into electrical charges. A charge-coupled device consists of many photosensitive units, typically measured in megapixels. When the surface of the photosensitive element is illuminated by light, each photosensitive unit reflects a charge onto the component. The signals generated by all the photosensitive units are added together to form a complete image.

[0034] The imaging module mainly utilizes the refraction principle of lenses in optical lenses to form images. That is, light from the scene passes through the imaging lens group to form a clear image on the focal plane, and the image of the scene is recorded by the photosensitive element located on the focal plane.

[0035] The aforementioned imaging module can be used in electronic devices with camera and image capture capabilities, such as optical endoscopes. Of course, besides optical endoscopes with imaging capabilities, these electronic devices can also be other electronic devices with imaging capabilities. The following explanation uses the application of the imaging module in an optical endoscope as an example, but it is not limited to this application.

[0036] refer to Figures 1 to 3The beam splitter structure includes: a first beam splitter 11 and a prism group arranged sequentially along the principal optical axis; the first beam splitter 11 includes a first incident surface, a first beam splitting surface 10, a first reflecting surface, and a first emitting surface, the first emitting surface is provided with a first filter 12, and the side of the first filter 12 away from the first emitting surface is used to set a first photosensitive element; the prism group includes a second beam splitter 21, the second beam splitter 21 includes a second incident surface, a second reflecting surface, and a second emitting surface; the second incident surface is parallel to and spaced apart from the first beam splitting surface 10, so that the first light incident on the first beam splitter 11 through the first incident surface... After being split by the first beam-splitting surface 10 and reflected by the first reflective surface, the second light incident on the first beam-splitting prism 11 passes through the first beam-splitting surface 10 and the second incident surface, enters the prism group, and is then reflected by the second reflective surface before exiting from the second light-emitting surface. The second light is the light ray that the first light is split by the first beam-splitting surface 10. The second light-emitting surface is provided with a second filter 22. At least one of the first filter 12 and the second filter 22 intersects but is not perpendicular to the corresponding target reflected optical axis. The side of the second filter 22 away from the second light-emitting surface is used to set the second photosensitive element.

[0037] The aforementioned principal optical axis is the optical axis of the first light.

[0038] The aforementioned target reflected optical axis is the optical axis of light emitted from the target light-emitting surface. The target light-emitting surface includes a first light-emitting surface and a second light-emitting surface. That is, the target reflected optical axis includes at least the first reflected optical axis in the first beam splitter 11 and the second reflected optical axis in the second beam splitter 21. At this time, at least one of the aforementioned first filter 12 and second filter 22 intersects with but is not perpendicular to the corresponding target reflected optical axis. The side of the second filter 22 away from the second light-emitting surface is used to set the second photosensitive element, including the first filter 12 having its thickness direction intersecting with but not perpendicular to the direction of the first reflected optical axis, and the second filter 22 having its thickness direction intersecting with but not perpendicular to the direction of the second reflected optical axis; it also includes the first filter 12 having its thickness direction intersecting with but not perpendicular to the direction of the first reflected optical axis, but the second filter 22 having its thickness direction perpendicular to the direction of the second reflected optical axis; it also includes the second filter 22 having its thickness direction intersecting with but not perpendicular to the direction of the second reflected optical axis, but the first filter 12 having its thickness direction perpendicular to the direction of the first reflected optical axis.

[0039] The first filter 12 can be bonded to the first light-emitting surface, but is not limited to this; the second filter 22 can be bonded to the second light-emitting surface, but is not limited to this. This not only helps to reduce the deflection angle of the light and reduce tolerance sensitivity, thereby indirectly improving the image quality, but also simplifies the assembly process of the beam splitter.

[0040] The first and second reflecting surfaces mentioned above can be, but are not limited to, total reflection surfaces, which helps to improve the utilization rate of light and thus improve brightness.

[0041] It should be noted that whether the first filter 12 and the second filter 22 are intersected but not perpendicular to the target reflected optical axis is different from the setting of the beam splitting surface of the corresponding beam splitter. For example, the first beam splitting surface 10 can be used to distinguish between fluorescence and visible light, so the first light includes fluorescence and visible light. When fluorescence imaging is performed on the imaging surface of the first photosensitive element of the beam splitter structure, the thickness direction of the first filter 12 can be parallel to the first reflected optical axis passing through the first light emitting surface, or the thickness direction of the first filter 12 can intersect but not be perpendicular to the first reflected optical axis passing through the first light emitting surface. The second light is visible light. When visible light imaging is performed on the imaging surface of the second photosensitive element of the beam splitter structure, the second light, whether it is visible light or visible light of a certain band or two bands, needs to be intersected but not perpendicular to the target reflected optical axis through one or more filters. In this way, the propagation path of stray light passing through the second filter 22 can be changed, causing the stray light to propagate in a direction away from the target reflection optical axis, thereby reducing the area entering the imaging surface of the corresponding photosensitive element. When this beam splitter structure is applied to an endoscope, it helps to reduce the generation of ghost images and shadows when the endoscope performs visible light imaging, thus helping to improve resolution.

[0042] The beam-splitting prism structure in this application, by having at least one of the first filter 12 disposed on the first light-emitting surface of the first beam-splitting prism 11 and the second filter 22 disposed on the second light-emitting surface of the prism group intersect but is not perpendicular to the corresponding target reflected optical axis, when stray light passes through the beam-splitting prism structure, the above-mentioned arrangement can change the propagation direction of the stray light, causing the stray light to propagate in a direction away from the corresponding target reflected optical axis. When the beam-splitting prism is used for imaging with an endoscope, the area of ​​stray light irradiating the imaging surface of the corresponding endoscope is reduced. In other words, the image formation of stray light on the corresponding photosensitive element is reduced, and the probability of stray light and ghost images appearing on the imaging surface of the corresponding photosensitive element is reduced, thereby indirectly improving the imaging quality of the imaging module.

[0043] The aforementioned beam-splitting prism structure can be a two-color beam-splitting prism capable of single-stage beam splitting. In this case, the prism group includes at least one beam-splitting prism, and this prism structure includes a beam-splitting surface. This beam-splitting surface can split the first light into two beams in one stage. Alternatively, the beam-splitting prism structure can be a three-color beam-splitting prism capable of double-stage beam splitting. In this case, the prism group includes at least two beam-splitting prisms, and this prism structure includes two beam-splitting surfaces. This prism structure can split the first light twice, sequentially passing it through the two beam-splitting surfaces, to form three beams. Finally, the beam-splitting prism structure can be a four-color beam-splitting prism capable of triple-stage beam splitting. In this case, the prism group includes at least three beam-splitting prisms, and this prism structure includes three beam-splitting surfaces. This prism structure can split a beam of light three times, sequentially passing it through the three beam-splitting surfaces, to form four beams.

[0044] The aforementioned beam-splitting prism structure can be used in endoscopes for visible light imaging, as well as in endoscopes for visible light and fluorescence imaging.

[0045] When the beam-splitting prism structure is used for two-color imaging in an imaging module for visible light imaging, the first light includes green light and a mixed light including red and blue light. When the beam-splitting prism structure is used for two-color imaging in an imaging module for visible light and fluorescence imaging, the first light may include fluorescence and visible light used for fluorescence imaging.

[0046] When the beam-splitting prism structure is used for 3-color imaging in an imaging module for visible light imaging, the first light can be visible light including RGB colors. When the beam-splitting prism structure is used for 3-color imaging in an imaging module for visible light and fluorescence imaging, the first light can be an excitation light for fluorescence imaging, a second light of green light, and a mixed light including red and blue light.

[0047] When the beam-splitting prism structure is used for 4-color imaging of an imaging module for visible light imaging, the first light can be visible light including RGB colors and yellow light. When the beam-splitting prism structure is used for 4-color imaging of an imaging module for visible light and fluorescence imaging, the first light can include fluorescence for fluorescence imaging and visible light including RGB colors.

[0048] It should be noted that the wavelength of visible light is the electromagnetic wave band that the human eye can perceive, and its range varies slightly in different literature. Generally, the wavelength of visible light is defined as 390nm-700nm. Red light has a wavelength of 625nm-740nm, yellow light 570nm-585nm, green light 577nm-492nm, and blue light 450nm-475nm.

[0049] Since fluorescence, as a known technique, can locate lesions for diagnosis and treatment, an imaging module containing a beam-splitting prism structure capable of simultaneously imaging visible light and fluorescence can achieve simultaneous imaging of visible light and fluorescence. This facilitates precise diagnosis of lesions, allowing doctors to better identify lesions and improve diagnostic efficiency. Because the emission wavelength of fluorescence typically falls within the visible or near-infrared band of 400nm to 900nm, the fluorescence wavelength in the embodiments of this application can be, but is not limited to, a laser with a wavelength of 400nm to 900nm.

[0050] For example, when the beam splitter structure is a two-color beam splitter, the above-mentioned beam splitter group includes a first beam splitter 11 and a second beam splitter 21. The second beam splitter 21 includes a second light-incident surface, a second reflective surface, and a second light-outceasing surface. The first beam is split into two beams after being split by the first beam-splitting surface 10 of the first beam-splitting prism 11. Part of the first beam continues to propagate in the first beam-splitting prism 11, is reflected by the first reflecting surface, and exits from the first beam-splitting surface 10. After passing through the first filter 12, it is imaged on the corresponding first photosensitive element. The second beam incident on the first beam-splitting prism 11 passes sequentially through the first beam-splitting surface 10 and the second incident surface, and is then incident on the second beam-splitting prism 21. It is propagated in the second beam-splitting prism 21, is reflected by the second reflecting surface, and exits from the second light-emitting surface. After passing through the second filter 22, it is imaged on the corresponding second photosensitive element. At the same time, the thickness direction of the first filter 12 intersects but is not perpendicular to the direction of the first reflected optical axis, and the thickness direction of the second filter 22 intersects but is not perpendicular to the direction of the second reflected optical axis. In this way, the two beams split from the first light can maintain their original light intensity as much as possible. While achieving fidelity and color preservation, when the two beams pass through the first filter 12 and the second filter 22 respectively and are imaged on the corresponding first and second photosensitive elements, stray light can be effectively reduced to illuminate the imaging surfaces of the first and second photosensitive elements. This reduces ghosting and shadows on the imaging surfaces of the first and second photosensitive elements, thereby improving the imaging quality of the imaging surfaces of the first and second photosensitive elements.

[0051] For example, when the beam splitter structure is a three-color beam splitter, the aforementioned prism group includes a first beam splitter 11, a second beam splitter 21, and a third beam splitter 31. The second beam splitter 21 includes a second incident surface, a second reflecting surface, a second beam splitting surface 20, and a second emitting surface. The third beam splitter 31 is disposed on the side of the second beam splitter 21 away from the first beam splitter 11. The third beam splitter 31 includes a third incident surface and a third emitting surface. The third incident surface is parallel to and spaced from the second beam splitting surface 20, so that the light incident on the second beam splitter 20... The second light on the beam-splitting surface 20 is split by the second beam-splitting surface 20 and reflected by the second reflecting surface, and then emitted from the second light-emitting surface. The third light incident on the second beam-splitting prism 21 passes through the second beam-splitting surface 20 and the third light-incident surface, and then enters the third beam-splitting prism 31 and is emitted from the third light-emitting surface. The third light is the light ray split by the second light through the second beam-splitting surface 20. The third light-emitting surface is provided with a third filter 32, and the side of the third filter 32 away from the third light-emitting surface is used to set the third photosensitive element.

[0052] In this embodiment, the target light-emitting surface further includes a third light-emitting surface, and the target reflected light axis includes the first reflected light axis in the first beam splitter 11, the second reflected light axis in the second beam splitter 21, and the third reflected light axis in the third beam splitter 31.

[0053] In some possible implementations of this embodiment, the thickness direction of the first filter 12 intersects but is not perpendicular to the direction of the first reflected optical axis; the thickness direction of the second filter 22 intersects but is not perpendicular to the direction of the second reflected optical axis; and the thickness direction of the third filter 32 intersects but is not perpendicular to the corresponding third reflected optical axis. With the above configuration, after the first light is split into three beams by the beam splitter structure, the three beams, after passing through the first filter 12, the second filter 22, and the third filter 32 respectively, can effectively reduce stray light irradiating the imaging areas of the first, second, and third photosensitive elements. This reduces the probability of ghosting and ghosting on the imaging surfaces of the first, second, and third photosensitive elements, thereby improving the imaging quality of these elements.

[0054] It should be noted that when one of the beams of the first light is fluorescent, the corresponding filter can be perpendicular to the reflected optical axis or intersect with it but not perpendicular; no specific limitation is made here.

[0055] For example, when the beam splitter structure is a 4-color beam splitter, the above-mentioned beam splitter group includes a second beam splitter 21, a third beam splitter 31, and a fourth beam splitter 41. The light-emitting side of the third beam splitter 31 is provided with a third filter 32, and the light-emitting side of the fourth beam splitter 41 is provided with a fourth filter 42. The principle is the same as that of the above-mentioned 3-color beam splitter, except that the beam splitting surface is increased by adding a fourth beam splitter 41 between the second beam splitter 21 and the third beam splitter 31, thereby splitting a beam of light into four beams. Then, the four beams pass through the corresponding filters and are imaged on the corresponding photosensitive elements.

[0056] The beam splitter structure in the imaging module described below will be illustrated using a four-color beam splitter structure that can simultaneously image RGB three-color light and fluorescence as an example.

[0057] refer to Figures 1 to 3 The third beam splitter 31 includes a third incident surface, a third beam splitting surface 30, and a third exiting surface, with the third beam splitting surface 30 and the third incident surface located on the same plane. The fourth beam splitter 41 includes a fourth incident surface, a fourth reflecting surface, and a fourth exiting surface, with the fourth reflecting surface parallel to and spaced apart from the third beam splitting surface 30, and the fourth incident surface parallel to and spaced apart from the second beam splitting surface 20, so that the third light after being split by the second beam splitting surface 20 is incident on the fourth beam splitter 41 and, after being split by the third beam splitting surface 30, a portion of the third light passes through... The third light is reflected from the fourth reflective surface and emitted from the fourth light-emitting surface; another part of the third light passes through the third beam-splitting surface 30, the third light-incident surface and the third light-emitting surface in sequence and then exits outside the third beam-splitting prism 31; the third light is the light ray emitted by the second light after being split by the second beam-splitting surface 20; the third light-emitting surface is provided with a third filter 32, and the side of the third filter 32 away from the third light-emitting surface is used to set the third photosensitive element; the fourth light-emitting surface is provided with a fourth filter 42, and the side of the fourth filter 42 away from the fourth light-emitting surface is used to set the fourth photosensitive element.

[0058] In this embodiment, the target light-emitting surface further includes a fourth light-emitting surface, and the target reflected light axis includes the first reflected light axis in the first beam splitter 11, the second reflected light axis in the second beam splitter 21, the third reflected light axis in the third beam splitter 31, and the fourth reflected light axis in the fourth beam splitter 41.

[0059] In some possible implementations of this embodiment, the thickness direction of the first filter 12 intersects but is not perpendicular to the direction of the first reflected optical axis; the thickness direction of the second filter 22 intersects but is not perpendicular to the direction of the second reflected optical axis; the thickness direction of the third filter 32 intersects but is not perpendicular to the corresponding third reflected optical axis; and the thickness direction of the fourth filter 42 intersects but is not perpendicular to the corresponding fourth reflected optical axis. With the above configuration, after the first light is split into four beams by the beam-splitting prism structure, the four beams, after passing through the first filter 12, the second filter 22, the third filter 32, and the fourth filter 42 respectively, form images on the corresponding four photosensitive elements. This effectively reduces stray light irradiating the imaging area of ​​the corresponding photosensitive element, greatly reducing the probability of ghosting on the imaging surfaces of the four photosensitive elements, thereby improving the imaging quality of all imaging surfaces.

[0060] It should be noted that whether the first filter 12, the second filter 22, the third filter 32, and the fourth filter 42 are intersecting but not perpendicular to the target reflected optical axis depends on the intensity of the imaging light. The intensity of fluorescence is weaker than that of visible light, and the same amount of stray light has a greater impact on the imaging quality of visible light imaging than on the imaging quality of fluorescence imaging. For example, the first beam-splitting surface 10 can be used to split the fluorescence and visible light, so the first light includes both fluorescence and visible light, and the second light is visible light. Then, when performing fluorescence imaging with this beam-splitting prism structure, the thickness direction of the first filter 12 can be parallel to the first reflected optical axis corresponding to the first light-emitting surface, and the thickness direction of the second filter 22 can also intersect but not be perpendicular to the second reflected optical axis corresponding to the second light-emitting surface. In other words, whether the first filter 12 needs to be intersecting but not parallel depends mainly on the imaging quality requirements, such as the resolution of fluorescence imaging. If the quality requirements for fluorescence imaging are high, then the thickness direction of the first filter 12 needs to intersect but not be perpendicular to the first reflected optical axis corresponding to the first light-emitting surface. If the quality requirements for fluorescence imaging are not high, then the thickness direction of the first filter 12 can be parallel to the first reflected optical axis corresponding to the first light-emitting surface; no specific limitation is made here. When performing visible light imaging with this beam-splitting prism structure, the second light, whether it is visible light or visible light of a certain band or two bands, needs to be intersecting but not perpendicular to the corresponding target reflected optical axis through one or more filters. In this way, the propagation path of stray light passing through the second filter 22 can be changed, causing the stray light to propagate in a direction away from the second reflective optical axis, thereby reducing the area entering the imaging surface of the corresponding second photosensitive element. When this beam splitter structure is applied to an endoscope, it helps to reduce the generation of ghost images and shadows in the visible light image, thereby reducing the impact of stray light and ghost images on the image quality, and thus helping to improve the imaging quality of visible light imaging.

[0061] refer to Figures 1 to 3 In some feasible implementations, the first, second, and third reflective optical axes are located in the same plane. That is, the light path when passing through the first beam splitter 11, the second beam splitter 21, and the third beam splitter 31 is transmitted in the same plane. This helps to reduce the volume of the beam splitter structure, thereby reducing the volume of the endoscope and facilitating the miniaturization design of the endoscope.

[0062] The aforementioned third and fourth reflection optical axes can be perpendicular, meaning the fourth reflection optical axis is perpendicular to the plane formed by the first, second, and third reflection optical axes. The aforementioned third beam splitter prism 31 and fourth beam splitter prism 41 together form a cuboid structure or a similar cuboid structure. (Refer to...) Figures 1 to 3 This design allows for a further reduction in the volume of the beam splitter structure, which in turn helps to further reduce the size of the endoscope. When the volume requirement for the beam splitter is not high, to reduce the difficulty of assembling the individual beam splitters and adapt to more scenarios, the third reflection optical axis can intersect but not be perpendicular to the fourth reflection optical axis, as shown in the reference. Figure 6 and Figure 7 No specific limitations are made here.

[0063] The structure of the filters in the beam splitter structure will be described in detail below, taking the structure of the first filter 12 and the second filter 22 as examples.

[0064] The two surfaces of the first filter 12 in its thickness direction may not be parallel, meaning the first filter 12 may also have a non-cubic block structure. The structure of the second filter 22 can be the same as that of the first filter 12, thus simplifying the manufacturing process and saving costs.

[0065] refer to Figure 2 In some feasible embodiments, the first filter 12 includes a first glass and a first filter layer disposed on the first glass. The first glass has a first surface and a second surface opposite each other along its thickness direction. The first surface is parallel to the first light-emitting surface, and the second surface is perpendicular to the first reflected optical axis, intersecting the optical axis. The second filter 22 includes a second glass and a second filter layer disposed on the second glass. The second glass has a third surface and a fourth surface opposite each other along its thickness direction. The third surface is parallel to the second light-emitting surface, and the fourth surface is perpendicular to the second reflected optical axis, intersecting the second reflected optical axis. The first and second surfaces can be parallel or intersecting but not perpendicular. The third and fourth surfaces can also be parallel or intersecting but not perpendicular.

[0066] The first filter layer described above can be, but is not limited to, a band-stop filter layer disposed on the first surface, which provides good filtering effect. The first filter layer may also include two sub-filter layers disposed on the first surface and the second surface, respectively, with the two sub-filter layers providing a filtering effect equivalent to the band-stop filter layer described above.

[0067] The filtering bands of the second filter layer and the first filter layer may partially overlap or not overlap. The first filter layer may, but is not limited to, a band-stop filter layer disposed on the third surface, resulting in good filtering performance. The second filter layer may also include two sub-filter layers disposed on the third and fourth surfaces, respectively, with the two sub-filter layers providing a filtering effect equivalent to the band-stop filter layer.

[0068] It should be noted that the aforementioned first glass can also be a cubic sheet structure, meaning that the two opposing surfaces of the first glass, namely the first face and the second face, are arranged parallel to each other, especially in the thickness direction of the first glass. The first face of the first glass refers to the surface closest to the first light-emitting surface, and this surface is parallel to the first light-emitting surface. The third face of the second glass refers to the surface closest to the second light-emitting surface, and this surface is parallel to the second light-emitting surface. The structural dimensions of the second glass can be the same as or different from those of the first glass; no specific limitations are imposed here.

[0069] With the above settings, different sizes of the first and second glass can be customized to suit different application scenarios.

[0070] In one feasible configuration, the first and second faces are arranged parallel to each other, and the third face is arranged to intersect with but not perpendicular to the fourth face, see reference. Figure 2 In another feasible approach, the first facet is positioned relative to the second facet but not perpendicular to it, and the third facet is positioned relative to the fourth facet but not perpendicular to it. This arrangement allows for arbitrary and free combination of the wavelengths of light splitting by the multiple beam-splitting faces of multiple beam-splitting prisms, reducing limitations on specific light sources such as fluorescence.

[0071] After multiple experiments, it was found that the acute angle formed between the thickness direction of the first filter 12 and the direction of the first reflected optical axis is the first included angle, which can be 5°, 6°, 7°, 8°, 9°, or 10°. In other words, the first included angle can be any angle from 5° to 10°.

[0072] The acute angle formed between the thickness direction of the second filter 22 and the direction of the second reflected optical axis is called the second included angle. The second included angle can be 5°, 6°, 7°, 8°, 9°, or 10°. That is, the second included angle can be any angle from 5° to 10°. This second included angle can be the same as the first included angle, so that the tilt angles of the first and second glass are the same, simplifying the process. Of course, the first included angle and the second included angle can also be different, which is not specifically limited here.

[0073] It should be noted that the structures of the third filter 32 and the fourth filter 42 can be the same as those of the first filter 12 and the second filter 22 in terms of structure and size. The structures and parameters of the first filter 12 and the second filter 22 can be referenced. For example, the acute angle formed between the thickness direction of the third filter 32 and the direction of the third reflected optical axis is the third included angle, and the acute angle formed between the thickness direction of the fourth filter 42 and the direction of the fourth reflected optical axis is the fourth included angle. The third included angle can be any angle from 5° to 10°, and the fourth included angle can be any angle from 5° to 10°. The first included angle, the second included angle, the third included angle, and the fourth included angle can be, but are not limited to, all the same. Furthermore, the connection methods between the third filter 32 and the fourth filter 42 and the corresponding third beam splitter 31 and fourth beam splitter 41 can also refer to the connection methods between the first filter 12 and the second filter 22 and the first beam splitter 11 and the second beam splitter 21, and will not be elaborated further here.

[0074] To improve image quality, in addition to designing the structural parameters of the filters as described above, the refractive index of the filters and the refractive index of the beam splitters are also important parameters affecting image quality. Through numerous experiments, it was found that the refractive indices of the filters can be 1.4, 1.5, and 1.6. The refractive indices of the first filter 12, the second filter 22, the third filter 32, and the fourth filter 42 can be the same. This means that multiple filters can use materials with the same refractive index, which helps save costs. Of course, the refractive indices of the multiple filters can also be different. The refractive indices of the beam splitters can be 1.5, 1.6, and 1.7. The refractive indices of the first beam splitter 11, the second beam splitter 21, the third beam splitter 31, and the fourth beam splitter 41 can be the same. This means that multiple beam splitters can use materials with the same refractive index, which helps save costs. Of course, the refractive indices of the multiple beam splitters can also be different.

[0075] To further improve imaging quality, the beam-splitting surface of the beam-splitting prism can be designed individually. Taking the first beam-splitting prism 11 as an example, not only does it need to have a beam-splitting layer set on the first beam-splitting surface 10 according to the beam-splitting band of the light to split the first light into two beams, but the first beam-splitting surface 10 can also be designed with partitions. In some feasible embodiments, the first beam-splitting surface 10 includes a beam-splitting region located near the optical axis and a light-absorbing region located away from the optical axis. The beam-splitting region is used to separate the first light and the second light, and the light-absorbing region is used to absorb the light.

[0076] The aforementioned beam-splitting area refers to the region through which the first light passes, i.e., the region where the beam-splitting layer is located. For example, when the first light passes through the beam-splitting area, it is split into its constituent beams. The light-absorbing area is the peripheral area of ​​the beam-splitting area, on which a light-absorbing layer is applied. It should be noted that the size of both the beam-splitting and light-absorbing areas must at least meet the optical requirements of the corresponding photosensitive element of the endoscope, such as brightness and resolution; however, specific limitations are not specified here.

[0077] By setting a light-absorbing area on the periphery of the beam-splitting area, stray light will be absorbed by the light-absorbing area after it shines on it. This helps to absorb non-imaging light such as stray light, thereby reducing the area of ​​stray light entering the imaging surface of the corresponding photosensitive element. This further reduces stray light and improves imaging quality.

[0078] In this embodiment, the first reflective surface is connected between the first incident light surface and the first emitting light surface, and at least part of the first reflective surface is located on the same plane as the first incident light surface. Alternatively, the entire first reflective surface may be located on the same plane as the first incident light surface, as shown in the reference. Figure 2 The first reflecting surface can also be partially located on the same plane as the first incident light surface. This arrangement simplifies the structure of the first beam splitter 11, simplifies the manufacturing process, and thus helps save costs.

[0079] It should be noted that, in this embodiment, in addition to the first beam-splitting surface 10 being designed in this way, one or both of the second beam-splitting surface 20 and the third beam-splitting surface 30 can also be partitioned as needed so that the imaging quality of the corresponding photosensitive elements meets the requirements.

[0080] In some feasible implementations, the non-light-transmitting surface of the beam-splitting prism structure is provided with a light-absorbing layer (not shown in the figure).

[0081] The aforementioned non-light-transmitting surface refers to a combination of surfaces through which light rays other than the first light, such as stray light, pass. The aforementioned non-light-transmitting surface may include a combination of multiple surface regions. For example, the non-light-transmitting surface in the first beam-splitting prism 11 includes the peripheral region of the first beam-splitting surface 10 excluding the central region near the optical axis, and also includes the peripheral region of the first reflecting surface excluding the central region near the optical axis.

[0082] The aforementioned light-absorbing layer can be a matte varnish, which can be carbon black / acrylic varnish or matte black epoxy varnish. This process is simple, mature, and low-cost. Alternatively, light absorption can be achieved by applying a surface microstructure light-absorbing material to the non-transparent surface.

[0083] By providing a light-absorbing layer on the non-light-transmitting surface of the beam-splitting prism structure, the area of ​​light entering the imaging surface of the corresponding photosensitive element through the non-light-transmitting surface is reduced. This helps to reduce the influence of light on the non-light-transmitting surface on the main imaging light, such as stray light, thereby indirectly improving the resolution.

[0084] refer to Figure 4 In some feasible ways, the non-light-transmitting surface of the beam-splitting prism structure is provided with a groove 40.

[0085] The groove 40 is a non-light-transmitting surface. In this way, the area of ​​the non-light-transmitting surface is increased within a limited structural range, which indirectly increases the absorption of non-imaging light such as stray light. At the same time, the surface of the groove 40 can also change the optical path of the non-imaging light, which helps to further reduce the area of ​​the non-imaging light entering the imaging surface of the corresponding photosensitive element, thereby indirectly improving the resolution of the imaging surface.

[0086] When the size requirement for the beam splitter is not high, in order to reduce the difficulty of assembling the various beam splitters and adapt to more scenarios, in some feasible ways, the prism assembly may also include one or more optical prisms 51. The aforementioned optical prisms 51 can serve to connect the various beam splitters.

[0087] This application embodiment also provides another beam-splitting prism structure, which is based on the prism group of the above embodiment including a second beam-splitting prism 21, a third beam-splitting prism 31, and a fourth beam-splitting prism 41. This prism group also includes an optical prism 51. The optical prism 51 may, but is not limited to, be disposed between the fourth beam-splitting prism 41 and the second beam-splitting prism 21. In this embodiment, reference... Figures 5 to 7 The fourth beam splitter 41 is designed with a pyramidal structure. The two surfaces of the optical prism 51 and the fourth beam splitter 41 are parallel but spaced apart. This beam splitter structure, while achieving four-color beam splitting, allows for the connection of the fourth beam splitter 41 with different shapes and the second beam splitter 21 by changing the shape and size of the optical prism 51. This broadens its application range and simplifies assembly. Furthermore, it reduces the design difficulty of the fourth beam splitter 41 and the second beam splitter 21, indirectly increasing the design flexibility of the prism assembly and thus indirectly saving costs.

[0088] It should be noted that the structure, materials, and other parameters of the first beam splitter 11, second beam splitter 21, third beam splitter 31, first filter 12, second filter 22, third filter 32, and fourth filter 42 in the beam splitter structure of this embodiment can refer to the above embodiments. Similarly, the refractive index of the optical prism 51 can also refer to the material and refractive index parameters of the beam splitter described above, and is not specifically limited here. The structures of the first filter 12, second filter 22, third filter 32, and fourth filter 42 in this embodiment are the same as those in the above embodiments in terms of structure and parameters.

[0089] This application also provides an endoscope including the beam-splitting prism structure of any of the above embodiments. The beneficial effects achieved by this endoscope are the same as those of the beam-splitting prism structure in the above embodiments, and will not be repeated here.

[0090] This application also provides an endoscope system, including a light source host, an image processing device, and an endoscope.

[0091] The aforementioned image processing device is communicatively connected to the light source host, and the light source host is detachably connected to the endoscope. For example, the light source host and the endoscope can be plugged in and disconnected. When the light source host and the image processing device are integrated into a single unit, there is no concept of a corresponding connection.

[0092] The endoscope system also includes a display that is communicatively connected to the image processing equipment. The display can be configured as a standalone device or integrated into the image processing equipment; no specific limitation is made here. The beneficial effects achieved by this endoscope system are the same as those of the endoscope in the above embodiments, and will not be repeated here.

[0093] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A beam-splitting prism structure, characterized in that, For use in endoscopes, the beam splitting prism structure includes: a first beam splitting prism (11) and a prism group arranged sequentially along the principal optical axis; The first beam splitter (11) includes a first light-incident surface, a first beam-splitting surface (10), a first reflective surface and a first light-emitting surface. The first light-emitting surface is provided with a first filter (12). The side of the first filter (12) away from the first light-emitting surface is used to set a first photosensitive element. The prism group includes a second beam splitter (21), which includes a second incident surface, a second reflecting surface, and a second emitting surface. The second incident surface is parallel to and spaced apart from the first beam splitting surface (10), so that the first light incident on the first beam splitting prism (11) after passing through the first incident surface is split by the first beam splitting surface (10) and reflected by the first reflecting surface, and then exits from the first exiting surface. The second light incident on the first beam splitting prism (11) passes through the first beam splitting surface (10) and the second incident surface, and then enters the prism group. After being reflected by the second reflecting surface, it exits from the second exiting surface. The second light is the light ray split by the first beam splitting surface (10) after passing through the first beam splitting surface (10). The second light-emitting surface is provided with a second filter (22), at least one of the first filter (12) and the second filter (22) intersects but is not perpendicular to the corresponding target reflected optical axis; the side of the second filter (22) away from the second light-emitting surface is used to set a second photosensitive element; Wherein, the target reflected optical axis is the optical axis of the light emitted from the target light-emitting surface, the target light-emitting surface includes the first light-emitting surface and the second light-emitting surface, and the main optical axis is the optical axis of the first light.

2. The beam-splitting prism structure according to claim 1, characterized in that, The second beam splitter (21) also includes a second beam splitting surface (20); The prism assembly also includes a third beam splitter (31). The third beam splitter (31) is disposed on the side of the second beam splitter (21) away from the first beam splitter (11); The third beam splitter (31) includes a third light-incident surface and a third light-outceasing surface; The third incident surface is parallel to and spaced from the second beam splitting surface (20), so that the second light incident on the second beam splitting surface (20) is split by the second beam splitting surface (20) and reflected by the second reflecting surface, and then exits from the second exiting surface. The third light incident on the second beam splitter (21) is split by the second beam splitting surface (20) and the third incident surface, and then enters the third beam splitter (31) and exits from the third exiting surface. The third light is the light ray split by the second beam splitting surface (20). The target light-emitting surface also includes a third light-emitting surface, and the target reflected optical axis includes the first reflected optical axis in the first beam splitter (11), the second reflected optical axis in the second beam splitter (21), and the third reflected optical axis in the third beam splitter (31). The thickness direction of the first filter (12) intersects with but is not perpendicular to the direction of the first reflected optical axis, and the thickness direction of the second filter (22) intersects with but is not perpendicular to the direction of the second reflected optical axis; and / or; The third light-emitting surface is provided with a third filter (32), and the thickness direction of the third filter (32) intersects with but is not perpendicular to the corresponding third reflective optical axis.

3. The beam-splitting prism structure according to claim 1, characterized in that, The second beam splitter (21) also includes a second beam splitting surface (20); The prism group also includes a third beam splitter (31) and a fourth beam splitter (41), wherein the fourth beam splitter (41) is disposed between the third beam splitter (31) and the second beam splitter (21); The third beam splitter (31) includes a third incident surface, a third beam splitter (30) and a third exit surface, wherein the third beam splitter (30) and the third incident surface are located on the same plane; The fourth beam splitter (41) includes a fourth incident surface, a fourth reflecting surface, and a fourth exiting surface. The fourth reflecting surface is parallel to and spaced apart from the third beam splitter (30), and the fourth incident surface is parallel to and spaced apart from the second beam splitter (20). This allows the third light, after being split by the second beam splitter (20), to enter the beam splitter (41) and be split by the third beam splitter (30). A portion of the third light is reflected by the fourth reflecting surface and exits from the fourth exiting surface; another portion of the third light passes sequentially through the third beam splitter (30), the third incident surface, and the third exiting surface before exiting the third beam splitter (31). The third light is the light ray split by the second light through the second beam splitter (20). The target light-emitting surface also includes a third light-emitting surface and a fourth light-emitting surface. The target reflected light axis includes the first reflected light axis in the first beam splitter (11), the second reflected light axis in the second beam splitter (21), the third reflected light axis in the third beam splitter (31), and the fourth reflected light axis in the fourth beam splitter (41). The thickness direction of the first filter (12) intersects with but is not perpendicular to the direction of the first reflected optical axis, and the thickness direction of the second filter (22) intersects with but is not perpendicular to the direction of the second reflected optical axis; and / or; The fourth light-emitting surface is provided with a fourth filter (42), and the thickness direction of the fourth filter (42) intersects with but is not perpendicular to the corresponding fourth reflective optical axis.

4. The beam-splitting prism structure according to claim 2 or 3, characterized in that, The first reflected optical axis, the second reflected optical axis, and the third reflected optical axis are located in the same plane.

5. The beam-splitting prism structure according to claim 3, characterized in that, The fourth beam splitter (41) has a pyramidal structure. The beam splitter group also includes an optical beam splitter (51). The optical beam splitter (51) is located between the fourth beam splitter (41) and the second beam splitter (21). The two surfaces of the optical beam splitter (51) and the fourth beam splitter (41) are parallel but spaced apart.

6. The beam-splitting prism structure according to claim 5, characterized in that, The first filter (12) includes a first glass and a first filter layer disposed on the first glass. The first glass has a first surface and a second surface opposite to each other along its thickness direction. The first surface is disposed parallel to the first light-emitting surface, and the second surface is perpendicular to the first reflected optical axis. The first surface intersects the optical axis. and / or; The second filter (22) includes a second glass and a second filter layer disposed on the second glass. The second glass has a third surface and a fourth surface opposite to each other along its thickness direction. The third surface is disposed parallel to the second light-emitting surface, the fourth surface is perpendicular to the second reflected light axis, and the third surface intersects with the first reflected light axis.

7. The beam-splitting prism structure according to claim 6, characterized in that, The first surface is inclined relative to the second surface.

8. The beam-splitting prism structure according to any one of claims 2-3 and 5-7, characterized in that, The acute angle formed between the thickness direction of the first filter (12) and the direction of the first reflected optical axis is the first included angle, which is 5° to 10°. And / or, the acute angle formed between the thickness direction of the second filter (22) and the direction of the second reflected optical axis is the second included angle, which is 5° to 10°.

9. The beam-splitting prism structure according to any one of claims 1-3 and 5-7, characterized in that, The first beam-splitting surface (10) includes a beam-splitting region located near the first reflective optical axis and a light-absorbing region located away from the first reflective optical axis. The beam-splitting region is used to separate the first light and the second light, and the light-absorbing region is used to absorb light. Alternatively, the first reflective surface is connected between the first incident light surface and the first emitting light surface, and the first reflective surface is at least partially located on the same plane as the first incident light surface.

10. The beam-splitting prism structure according to any one of claims 1-3 and 5-7, characterized in that, The non-light-transmitting surface of the beam splitter structure is provided with a light-absorbing layer; and / or, the non-light-transmitting surface of the beam splitter structure is provided with a groove (40).

11. An endoscope, characterized in that, include: The beam-splitting prism structure as described in any one of claims 1-10.

12. An endoscope system, characterized in that, include: The light source host, the image processing device, and the endoscope as described in claim 11.

Images