An endoscope, endoscope assembly, and surgical microscope system

Abstract

The application provides an endoscope, an endoscope assembly and a surgical microscope system. Two or more light beams collected by two or more light collecting modules from different angles of an observation target are combined into coaxial propagation light beams by a beam combination module. An image sensor is arranged on an image side after beam combination to image the light beams collected from different angles of the observation target, so as to obtain stereoscopic image information of the endoscope observation target. The present application changes double optical path imaging into single optical path imaging by arranging the beam combination module, reduces part of the optical path, reduces the number of optical elements, reduces the cost of the endoscope, realizes miniaturization of the endoscope, and calibrates three-dimensional amplitude. Only the optical elements need to change the light propagation path physically, without the need for complex 3D image processing algorithms, and the number of optical elements that need to be precisely assembled and calibrated can be reduced, so as to reduce the complexity of imaging.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to an endoscope, an endoscope assembly, and a surgical microscope system. Background Technology

[0002] In the fields of medical and precision testing, 3D endoscopes, with their stereoscopic vision imaging capabilities, can provide richer spatial depth information, significantly improving the accuracy of observation and operation, and have important application value in scenarios such as minimally invasive surgery and internal structure inspection.

[0003] Currently, 3D endoscopes are implemented in the following ways: Figure 1 As shown, a dual-path optical imaging system is set up to observe the target from the left and right perspectives. The dual-path optical imaging system adopts a physically separated independent optical path design. Each beam imaging system includes an imaging lens group and an image sensor. Beams from different angles of the observed target enter the dual-path beam imaging system "parallel". The dual-path optical imaging system synchronously acquires left and right perspective images with a fixed baseline offset (about 5mm). In addition to time alignment, the back-end processor also needs to crop and stitch the images acquired by the two image sensors. Complex pixel-level spatial alignment and color calibration are required during stitching to obtain the 3D video stream image.

[0004] Although this solution can provide high-quality stereoscopic images, it has significant drawbacks: 1. The dual-path optical imaging system uses a physically separate design, which makes it difficult to miniaturize the endoscope due to its large diameter; 2. Each path in the dual-path optical imaging system requires a separate imaging lens group and image sensor, resulting in a large number of components and high costs; 3. The images obtained by the dual-path optical imaging system need to be cropped and stitched together, requiring complex pixel-level spatial alignment and color calibration, resulting in high algorithm complexity; 4. The optical components of each path in the dual-path optical imaging system require precise assembly and calibration, which involves a large workload. Summary of the Invention

[0005] The purpose of this application is to provide an endoscope, endoscope assembly, and surgical microscope system to solve the above-mentioned problems.

[0006] The first aspect of this application provides an endoscope, comprising: two or more light-collecting modules for collecting light beams from different angles of an endoscope-observed target; a beam-combining module including an optical element having a semi-transparent and semi-reflective surface; the beam-combining module being used to combine the light beams of the observed target collected by each light-collecting module into a coaxially propagating light beam through the semi-transparent and semi-reflective surface; and an image sensor for imaging the light beams collected by the light-collecting modules from different angles of the observed target, thereby obtaining stereoscopic image information of the endoscope-observed target.

[0007] In some embodiments, the beam combining module further comprises a mirror and / or a prism, and the light beams of the endoscopic observation target collected by different light collecting modules are adjusted to the semi-transmissive and semi-reflective surface through the mirror and / or the prism in combination with the position of the semi-transmissive and semi-reflective surface.

[0008] In some embodiments, the beam combining module comprises a first surface, a second surface, a third surface and a fourth surface; wherein the first surface, the second surface and the third surface are full reflective surfaces, and the fourth surface is a semi-transmissive and semi-reflective surface; the first surface and the third surface are used for reflecting the light beams of the observation target collected from different angles; the first surface is used for reflecting the light beams of the observation target to the second surface, and the second surface is used for reflecting the light beams to the fourth surface so that the light beams are transmitted out of the fourth surface; the third surface is used for reflecting the light beams of the observation target to the fourth surface, and the fourth surface reflects the light beams out, and the reflected light beams of the fourth surface coincide with the transmitted light beams.

[0009] In some embodiments, the angle difference between the first surface and the second surface and the angle difference between the third surface and the fourth surface are equal.

[0010] In some embodiments, the values of the two angle differences are determined according to the ratio of the double light path interval length to the calibration distance, wherein the double light path interval length is half of the distance between the centers of the front ends of the two light collecting modules, and the calibration distance is the distance between the connecting line of the centers of the front ends of the two light collecting modules and the observation target.

[0011] In some embodiments, the beam combining module comprises a plurality of prisms arranged in the objective lens barrel in a gapless manner; a semi-transmissive and semi-reflective film layer is coated on the contact surface of at least one pair of adjacent prisms; and the semi-transmissive and semi-reflective film layer is used for combining the light beams of the observation target collected by each light collecting module from different angles into coaxially propagating light beams.

[0012] In some embodiments, the beam combining module comprises a first prism, a second prism, a third prism and a fourth prism; the second prism and the third prism are located in the middle region of the cross section of the objective lens barrel and are used for collecting the light beams of the observation target from different angles, respectively, and the second prism is adjacent to the third prism; the second prism and the third prism have a first adjacent surface and a second adjacent surface, wherein the first adjacent surface is a full reflective surface, and the second adjacent surface is a semi-transmissive and semi-reflective surface; the adjacent surfaces of the first prism and the second prism reflect the light beams of the observation target collected by the second prism to the first adjacent surface, and the first adjacent surface reflects the light beams to the second adjacent surface, and the light beams are transmitted out of the second adjacent surface; the adjacent surfaces of the third prism and the fourth prism reflect the light beams of the observation target collected by the third prism to the second adjacent surface, and the second adjacent surface reflects the light beams out, and the reflected light beams of the second adjacent surface are parallel to the transmitted light beams.

[0013] In some embodiments, the endoscope further comprises a liquid lens arranged on the light propagation path between the beam combination module and the image sensor, and a focal length of the liquid lens is dynamically changed by regulating a shape of liquid in the liquid lens.

[0014] In some embodiments, the image sensor comprises a white light image sensor for white light imaging and a fluorescence sensor for fluorescence imaging; accordingly, the endoscope further comprises a beam splitter arranged on the light propagation path between the beam combination module and the image sensor; the beam splitter is used to separate the propagation directions of the white light and the fluorescence in the combined light beam, and the separated white light is incident on the white light sensor and the separated fluorescence is incident on the fluorescence sensor.

[0015] In some embodiments, the endoscope further comprises a parallel plate arranged on the light propagation path between the beam combination module and the image sensor, and the parallel plate is used to filter out the excitation light of the fluorescence.

[0016] In some embodiments, the light collecting module comprises a front group negative lens for condensing light and adjusting the direction of the incident light beam and adjusting the field of view range; and an optical switch arranged at the front end of the front group negative lens, used to control whether the light collecting module collects the light beam of the observation target of the endoscope.

[0017] The second aspect of the present application provides an endoscope assembly comprising the beam combination module in any of the endoscopes of the first aspect.

[0018] The third aspect of the present application provides a surgical microscope system comprising: the endoscope of any of the first aspect; and an image processing device used to process the stereoscopic image information of the observation target of the endoscope.

[0019] The endoscope, the endoscope assembly and the surgical microscope system provided by the present application combine the light beams collected by two or more light collecting modules from different angles of the observation target into coaxial light beams through the beam combination module, and the image sensor is arranged on the image side after beam combination to image the light beams collected from different angles of the observation target, thereby obtaining the stereoscopic image information of the observation target of the endoscope. The present application changes the double light path imaging into single light path imaging through the arrangement of the beam combination module, reduces part of the light path and thereby reduces the number of optical elements, reduces the cost of the endoscope and realizes the miniaturization of the endoscope; three-dimensional vergence calibration only needs to change the light propagation path physically by optical elements, without the need for complex 3D image processing algorithms (such as cropping, splicing, pixel-level spatial alignment and color calibration), and the number of optical elements that need to be precisely assembled and calibrated can be reduced, thereby reducing the complexity of imaging. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced. Obviously, the accompanying drawings in the following description only represent some embodiments described in the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without any creative effort.

[0021] Figure 1 A schematic diagram of the principle of an existing endoscope;

[0022] Figure 2 A schematic diagram of the principle of an endoscope provided by the present application;

[0023] Figure 3 A schematic diagram of the principle of another endoscope provided by the present application;

[0024] Figure 4 A schematic diagram of a beam combination module composed of four prisms and matched with two light receiving modules provided by the present application;

[0025] Figure 5 A schematic diagram of a 3D, 4K white light microscopic endoscope (0°) imaging system;

[0026] Figure 6 A schematic diagram of a 3D, 4K white light microscopic endoscope (30°) imaging system;

[0027] Figure 7 A 20mm MTF curve of a 3D, 4K white light microscopic endoscope (0° and 30°) imaging system;

[0028] Figure 8 A 50mm MTF curve of a 3D, 4K white light microscopic endoscope (0° and 30°) imaging system;

[0029] Figure 9 A 200mm MTF curve of a 3D, 4K white light microscopic endoscope (0° and 30°) imaging system;

[0030] Figure 10 A schematic diagram of a 3D, 4K white light-fluorescence endoscope imaging system (0°);

[0031] Figure 11 A schematic diagram of a 3D, 4K white light-fluorescence endoscope imaging system (30°);

[0032] Figure 12 A 20mm MTF curve of a 3D, 4K white light-fluorescence microscopic endoscope (0° and 30°) imaging system;

[0033] Figure 13MTF curve for 3D, 4K white light-fluorescence microscopic endoscope (0° and 30°) imaging system at 50mm;

[0034] Figure 14 MTF curve for 3D, 4K white light-fluorescence microscopic endoscope (0° and 30°) imaging system at 200mm. DETAILED DESCRIPTION

[0035] In order to enable persons skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described in the following with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by persons skilled in the art without creative labor should belong to the protection scope of the present application.

[0036] An endoscope is a precision optical instrument that enters the body through a natural body cavity or a small incision to observe, diagnose and treat internal structures.

[0037] The present application provides an endoscope, as shown in the accompanying drawings, the endoscope comprises a light receiving module 10, a beam combining module 20 and an image sensor 30. Figure 2

[0038] The light receiving module 10 comprises at least two, and the present application only takes an endoscope comprising two light receiving modules as an example to illustrate the endoscope provided by the present application. Two or more light receiving modules 10 are used to collect light beams of an endoscope observation target from different angles. The endoscope observation target can be a target tissue or a fluorescent target. The "light beams of the observation target" can be the light of a light source reflected by the endoscope observation target, can be the light emitted by the endoscope observation target itself, or can be the fluorescence generated by the endoscope observation target excited by an external light source.

[0039] The at least two light receiving modules 10 are located at different positions of the observation target, and the positions of the at least two light receiving modules 10 relative to the observation target can be relatively close and have small differences, but still have differences. The difference in the positions makes the light beams of the same point A on the observation target collected by the "different light receiving modules 10" intersect, i.e., converge at the point A on the observation target. The at least two light receiving modules 10 collect light beams of the observation target from different angles, which makes the finally formed image have information of different angles, so that the image presents a stereoscopic effect.

[0040] In the prior art, as shown in the accompanying drawings, Figure 1 ​As shown, in a dual-beam imaging system, the optical axes (i.e., reference axes) of the dual-beam imaging system are parallel. Therefore, each of the two optical imaging systems has a light-receiving module at its front end. However, the target beams received by the two light-receiving modules for imaging are parallel. In contrast, in this application, the target beams received by the two or more light-receiving modules 10 for imaging are not parallel, but intersecting.

[0041] In some embodiments, such as Figure 3 As shown, the light-gathering module 10 of the endoscope may include a front negative lens 11, which is a lens combination close to the observation target, used to focus light, adjust the direction of the incident beam, and adjust the field of view.

[0042] The front negative lens 11 directly receives the light beam from the observed target, which expands the system's field of view, effectively compensates for overall aberrations, and shares the optical power after the subsequent beam combining module 20.

[0043] In some embodiments, such as Figure 3 As shown, the light-receiving module 10 of the endoscope may further include an optical switch 12 for controlling whether the light-receiving module 10 collects the light beam of the endoscope's observation target. The optical switch 12 has an on state and an off state. In the on state, the light beam of the endoscope's observation target passes through the optical switch and enters the front negative lens 11; in the off state, the light beam of the endoscope's observation target is blocked and does not enter the front negative lens.

[0044] The optical switch 12 can specifically be a liquid crystal polarization switch. A liquid crystal switch is a miniature optical device that dynamically switches the polarization state of light by controlling the electric field based on the optical properties of liquid crystal materials. By precisely controlling the voltage applied to the liquid crystal cell, the alignment direction of the liquid crystal molecules can be actively and rapidly changed, thereby precisely controlling the state of polarized light passing through the lens (transmission or blocking), achieving a rapid optical switching function.

[0045] The beam combining module 20 includes an optical element with a semi-transparent and semi-reflective surface. The semi-transparent and semi-reflective surface allows some light beams to pass through and some to be reflected, thereby achieving beam splitting, beam combining, or beam redirection. The optical element with the semi-transparent and semi-reflective surface can be, for example, a plane beam splitter, a stereo beam splitter, a polarizing beam splitter, a thin-film beam splitter, an adjustable beam splitter, etc.

[0046] A semi-transparent and semi-reflective surface can be a surface that splits light according to energy or wavelength. Specifically, the semi-transparent and semi-reflective surface in beam combining module 20 can be a surface that splits light according to energy.

[0047] The semi-transmissive and semi-reflective surface can be configured to transmit a certain proportion of light and reflect the remaining proportion of light. Specifically, the proportion can be 50% or close to 50% so that the optical parameters (e.g. illumination intensity, color, etc.) of the observation target at different angles in the final image are relatively balanced.

[0048] The number of semi-transmissive and semi-reflective surfaces can be one or multiple. For example, in the case of two light collecting modules 10, only one semi-transmissive and semi-reflective surface can be used; in the case of three or more light collecting modules 10, two or more semi-transmissive and semi-reflective surfaces can be used. The optical element with the semi-transmissive and semi-reflective surface can also be a semi-transmissive and semi-reflective film coated on one surface of a prism, or a plate coated with a semi-transmissive and semi-reflective film.

[0049] In some embodiments, the beam combining module further comprises a mirror and / or a prism. The beam combining module 20 can be a combination of a mirror and an optical element with a semi-transmissive and semi-reflective surface, a combination of a prism and an optical element with a semi-transmissive and semi-reflective surface, or a combination of a mirror, a prism and an optical element with a semi-transmissive and semi-reflective surface. The light beams of the endoscopic observation target collected by different light collecting modules are adjusted to the semi-transmissive and semi-reflective surface by the combination of the position of the mirror and / or the prism and the semi-transmissive and semi-reflective surface.

[0050] The beam combining module 20 is used to combine the light beams of the observation target collected by each light collecting module 10 into a coaxial light beam by the semi-transmissive and semi-reflective surface. That is, the light beams of the observation target collected by each light collecting module 10 become a parallel light beam after passing through the beam combining module 20.

[0051] The image sensor 30 is arranged in the image side of the combined light beam and is used to image the light beams collected by the light collecting module 10 from different angles of the observation target, i.e. to image the light beam emitted from the beam combining module 20, thereby obtaining the stereoscopic image information of the endoscopic observation target. Since the light beam emitted from the beam combining module 20 is a parallel light beam, the image sensor 30 arranged on the propagation path of the parallel light beam can obtain a better imaging effect.

[0052] The endoscope provided in the application combines the light beams collected from different angles of the observation target into coaxial propagation light beams through the beam combining module, and sets an image sensor on the image side after beam combining to image the light beams collected from different angles of the observation target, so as to obtain the stereoscopic image information of the observation target of the endoscope. The present scheme changes the double optical path imaging into single optical path imaging through the setting of the beam combining module, reduces part of the optical path and thus reduces the number of optical elements, lowers the cost of the endoscope, and realizes the miniaturization of the endoscope; three-dimensional vergence calibration only needs to change the light propagation path physically through the optical element, without the need for complex 3D image processing algorithms (for example, cropping, splicing, pixel-level spatial alignment, color calibration), and the number of optical elements that need to be precisely assembled and calibrated can be reduced, so as to reduce the complexity of imaging.

[0053] The endoscope provided in the application combines the light beams collected from different angles of the observation target into coaxial propagation light beams through the beam combining module, and sets an image sensor on the image side after beam combining to image the light beams collected from different angles of the observation target, so as to obtain the stereoscopic image information of the observation target of the endoscope. The present scheme changes the double optical path imaging into single optical path imaging through the setting of the beam combining module, reduces part of the optical path and thus reduces the number of optical elements, lowers the cost of the endoscope, and realizes the miniaturization of the endoscope; three-dimensional vergence calibration only needs to change the light propagation path physically through the optical element, without the need for complex 3D image processing algorithms (for example, cropping, splicing, pixel-level spatial alignment, color calibration), and the number of optical elements that need to be precisely assembled and calibrated can be reduced, so as to reduce the complexity of imaging.

[0054] In some embodiments, the beam combining module 20 includes a first surface, a second surface, a third surface and a fourth surface. Among them, the first surface, the second surface and the third surface are total reflection surfaces, and the fourth surface is a semi-transparent and semi-reflective surface.

[0055] The first surface and the third surface are used for reflecting the light beams of the observation target collected from different angles.

[0056] The first surface is used for reflecting the light beams of the observation target to the second surface, and the second surface is used for reflecting the light beams to the fourth surface, so that the light beams are transmitted out of the fourth surface.

[0057] The third surface is used for reflecting the light beams of the observation target to the fourth surface, and the fourth surface is used for reflecting the light beams out, and the reflected light beams of the fourth surface coincide with the transmitted light beams.

[0058] The beam combining module 20 described above can realize the beam combining of the light beams of the observation target collected from different angles through light reflection and transmission. At the same time, the vergence calibration at the hardware level can be directly realized by physically adjusting the inclination angles of the surfaces, so that the light beams of the observation target collected from different angles naturally coincide on the image plane (i.e. the image sensor), and the integrity of the original image information is maximally preserved.

[0059] Figure 4FIG. 1 is a schematic diagram of a beam combining module 20 composed of four prisms matched with two light collecting modules, wherein the beam combining module 20 includes a first prism B1, a second prism B2, a third prism B3 and a fourth prism B4. The first prism B1 is arranged adjacent to the second prism B2, the second prism B2 is arranged adjacent to the third prism B3, and the third prism B3 is arranged adjacent to the fourth prism B4.

[0060] The second prism B2 and the third prism B3 are located in the middle region of the cross section of the objective lens barrel 40 and are used to collect light beams from the observation target at different angles, respectively. The second prism B2 is arranged adjacent to the third prism B3. The second prism B2 and the third prism have a first adjacent surface S3 and a second adjacent surface S4, wherein the first adjacent surface S3 is a total reflection surface, and the second adjacent surface S4 is a semi-transparent and semi-reflective surface.

[0061] The light beams of the measured object collected by the light collecting module are incident from the surface S1 of the second prism B2, reflected by the adjacent surface S2 of the first prism B1 and the second prism B2 to the first adjacent surface S3, then reflected by the first adjacent surface S3 to the second adjacent surface S4, and transmitted from the second adjacent surface S4 into the third prism B3, and then emitted from the surface S7 of the third prism B3.

[0062] The light beams of the measured object collected by the other light collecting module are incident from the surface S5 of the third prism B3, then reflected by the adjacent surface S6 of the third prism B3 and the fourth prism B4 to the second adjacent surface S4, and then reflected by the second adjacent surface S4. The reflected light is emitted from the surface S7 of the third prism B3. The light reflected by the second adjacent surface S4 is parallel to the light transmitted from the second adjacent surface S4.

[0063] Figure 4 The adjacent surface S2 of the first prism B1 and the second prism B2 in FIG. 1 is the first surface, the adjacent surface S6 of the third prism B3 and the fourth prism B4 is the third surface, the adjacent surface S3 of the second prism B2 and the third prism B3 is the second surface, and the adjacent surface S4 of the second prism B2 and the third prism B3 is the fourth surface, which is a semi-transparent and semi-reflective surface.

[0064] Figure 4 The beam combining module 20 in FIG. 1 is only an example. In some embodiments, the beam combining module 20 including the first surface, the second surface, the third surface and the fourth surface can also be implemented without prisms. For example, the surfaces S2, S3 and S6 in FIG. 1 can be replaced by total reflection mirrors, the surface S4 in FIG. 1 can be replaced by a semi-transparent and semi-reflective plate, and a beam combining module 20 without prisms can be obtained. Figure 4 Figure 4 The surface S4 in FIG. 1 can be replaced by a semi-transparent and semi-reflective plate, and a beam combining module 20 without prisms can be obtained. In some embodiments, only part of the surfaces in FIG. 1 can be replaced while part of the prisms are retained, and a beam combining module 20 including both mirrors and prisms can be obtained. Figure 4 ​​

[0065] In some embodiments, the angle difference between the first surface and the second surface, and the angle difference between the third surface and the fourth surface are equal. The values of the two angle differences are determined according to the ratio of the double light path interval and the calibration distance, wherein the double light path interval is half of the distance between the centers of the two light receiving modules, and the calibration distance is the distance between the line connecting the centers of the two light receiving modules and the observation target.

[0066] As shown in Figure 5 , A is the observation target, a represents the double light path interval length (which is equal to half the length of the line connecting the centers of the two light receiving modules), and b represents the distance between the line connecting the centers of the two light receiving modules and the observation target, Figure 5 , the angle θ is equal to the angle difference between the first surface and the second surface, and the angle difference between the third surface and the fourth surface. That is, the values of the angle difference between the first surface and the second surface, and the angle difference between the third surface and the fourth surface are θ = arctan(a / b), wherein θ is the angle difference between the first surface and the second surface, and also the angle difference between the third surface and the fourth surface.

[0067] In some embodiments, the beam combining module 20 can not only include the first surface, the second surface, the third surface, and the fourth surface described above, but can also need to set more reflecting surfaces and semi-reflecting surfaces on the light propagation path. The implementation of the beam combining module 20 cannot be exhausted.

[0068] In some embodiments, in combination with Figure 4 and Figure 5 , the beam combining module 20 includes a plurality of prisms arranged in a gapless manner in the objective lens barrel 40. The contact surface of at least one pair of adjacent prisms is coated with a semi-reflecting film layer. The semi-reflecting film layer is used to combine the light beams of the observation target collected by each light receiving module 10 from different angles into coaxially propagating light beams.

[0069] As shown in Figure 4 , the beam combining module 20 includes a plurality of prisms arranged in a gapless manner in the objective lens barrel 40. This structure simplifies the assembly process of the beam combining module 20, and omits the complex optical element calibration operation, making it easier to replace. Therefore, the endoscope can conveniently replace the beam combining module 20 to adapt to different observation angle requirements.

[0070] A main objective lens group T can be arranged on the light propagation path between the beam combining module 20 and the image sensor 30, which can specifically include a plurality of optical elements, such as convex lenses, concave lenses, etc.

[0071] In some embodiments, the endoscope further comprises a liquid lens 50 disposed on the light propagation path between the beam combination module 20 and the image sensor 30, and the focal length of the liquid lens is dynamically changed by regulating the shape of the liquid in the liquid lens.

[0072] A liquid lens is generally composed of two immiscible transparent liquids (such as oil and water), and the liquids are confined in a light-transmissive container (such as a glass or polymer cavity). By external control means (such as applying voltage, pressure or temperature change), the surface tension or stress state of the liquid can be changed, and then the curvature radius of the liquid interface (for example, the liquid surface changes from “flat” to “convex” or “concave”) or the refractive index is adjusted. Since the focal length of the lens is directly related to the curvature radius and the refractive index, the change of the curvature and the refractive index will change the focal length of the lens in real time, realizing the dynamic focusing without mechanical moving parts. Common regulation mechanisms of liquid transparency include: electro-wetting effect, gas or hydraulic drive, temperature regulation.

[0073] Specifically, the liquid lens 50 based on the electro-wetting effect can be used for regulation, which can realize millisecond-level accurate regulation and can perform instantaneous switching in the near-far focusing range. The focusing function can be realized without mechanical movement throughout the process, so that the endoscope can still output clear and enlarged endoscope images in real time when moving in a complex cavity environment.

[0074] For an endoscope, the larger the aperture F# is, the lower the light quantity is, the lower the image resolution is, the larger the depth of field is, and the larger the range that can be clearly seen is. Conversely, the smaller the aperture F# is, the larger the light quantity is, the higher the image resolution is, the smaller the depth of field is, and the smaller the range that can be clearly seen is. The current design of the endoscope cannot improve the depth of field range and the image resolution. When designing the endoscope, the depth of field range is usually prioritized over the image resolution and the light quantity.

[0075] The mainstream scheme of the current commercial 3D endoscope is a fixed focus design using a small aperture (f / 8-f / 16) to obtain a large depth of field (>50mm) to cover a conventional field of view. The structure is simple and reliable, but it cannot be finely focused and the light energy is low, and the performance is poor. The value of the aperture F# of the current endoscope is usually F6, which has the advantages of large depth of field and large visible range, but also has the defect of low resolution.

[0076] The application proposes that the liquid lens 50 disposed on the light propagation path between the beam combination module 20 and the image sensor 30 can significantly improve the resolution of the image at any position outside the depth of field, so that the endoscope can reduce the F# value (i.e., increase the depth of field) while improving the image resolution.

[0077] In some embodiments, the image sensor 30 includes a white light sensor 31 for white light imaging and a fluorescence sensor 32 for fluorescence imaging. Accordingly, the endoscope further includes a beam splitter 60 disposed on the light propagation path between the beam combining module 20 and the image sensor 30. The beam splitter 60 is configured to separate the propagation directions of the white light and the fluorescence in the combined light beam, and the separated white light is incident on the white light sensor 31 and the separated fluorescence is incident on the fluorescence sensor 32.

[0078] Further, in some embodiments, the endoscope further includes a parallel plate 70 disposed on the light propagation path between the beam combining module 20 and the image sensor 30, and the parallel plate 70 is configured to filter out the excitation light of the fluorescence.

[0079] In some embodiments, the endoscope further includes replaceable endoscope assemblies for achieving different observation angles, and the endoscope assemblies include the above-described beam combining module 20.

[0080] The endoscope provided in the present application can achieve clear observation of images in the range of 20-200 nm, and the F# of the aperture is less than F5, for example, F4.5, F4, F3.9, F3.5.

[0081] The present application further provides an endoscope assembly including the beam combining module in any of the above-described endoscopes, and different endoscope assemblies can be used to achieve different observation angles.

[0082] The present application further provides a surgical microscope system including any of the above-described endoscopes and an image processor, wherein the image processor is configured to process the stereoscopic image information of the observation target of the endoscope, such as displaying images, marking images according to user operations, etc.

[0083] The present application takes an endoscope including left and right light receiving modules as an example, and provides the following embodiments of the endoscope.

[0084] Embodiment 1

[0085] Figure 5It is a schematic diagram of 3D4K white light microscopic endoscope imaging system (0°). The endoscope imaging system is composed of the following components in order from the object side to the image side: front group negative lens (left light path and right light path), prism group (left light path and right light path), diaphragm (left light path and right light path share the same light path), main objective group (left light path and right light path share the same light path), spacer ring (left light path and right light path share the same light path), objective lens barrel (left light path and right light path share the same light path), and one piece of image sensor (white light). The main objective group includes: liquid lens group and fixed lens group, which is composed of: optical filter, spherical single lens, three-cemented spherical lens, double-cemented spherical lens, and parallel flat plate. The white light endoscope imaging system has a wavelength of 415nm-670nm, a half field angle of 48°, an F# of 3.9, and a binocular calibration distance of 50mm. The system can observe clear and enlarged images within a range of 20mm~200mm through liquid lens focusing.

[0086] Example 2

[0087] Figure 6 It is a schematic diagram of 3D4K white light microscopic endoscope imaging system (30°). The endoscope imaging system is composed of the following components in order from the object side to the image side: front group negative lens (left light path and right light path), prism group (left light path and right light path), diaphragm (left light path and right light path share the same light path), main objective group (left light path and right light path share the same light path), spacer ring (left light path and right light path share the same light path), objective lens barrel (left light path and right light path share the same light path), and one piece of image sensor (white light). The main objective group includes: liquid lens group and fixed lens group, which is composed of: optical filter, spherical single lens, three-cemented spherical lens, double-cemented spherical lens, and parallel flat plate. The white light endoscope imaging system has a wavelength of 415nm-670nm, a half field angle of 48°, an F# of 3.9, and a binocular calibration distance of 50mm. The system can observe clear and enlarged images within a range of 20mm~200mm through liquid lens focusing.

[0088] The above-mentioned examples 1 and 2 share the same light path. The difference between example 2 and example 1 is the prism group. In example 3, the prism group is designed through angles to meet the requirement of 30° viewing angle. The liquid lens in examples 1 and 2 is an optical element that realizes dynamic focusing by changing the surface curvature of the liquid. Its core principle is to use the electro-wetting effect or mechanical pressure driving technology to make the transparent liquid (such as conductive solution and insulating oil) in the sealed cavity deform. When voltage or pressure is applied, the liquid interface curvature changes in real time, thereby changing the light beam refraction path. Without mechanical moving parts, focusing can be completed within milliseconds. This technology has the advantages of miniaturization, low power consumption, and high response speed. The MTF imaging curves of the imaging system at 20mm, 50mm, and 200mm are as follows: Figure 7 、 Figure 8 、 Figure 9As shown, the 300 lp / mm resolution of both is greater than 0.2. Compared with the traditional fixed-focus endoscope (200 lp / mm), the resolving power of the imaging system is significantly improved.

[0089] Example 3

[0090] Figure 10 Figure 1 is a schematic diagram of a 3D4K white light-fluorescence endoscope imaging system (0°). The endoscope imaging system is composed of the following components in order from the object side to the image side: a front group negative lens (left light path and right light path), a prism group (left light path and right light path), a diaphragm (left light path and right light path share the light path), a main objective lens group (left light path and right light path share the light path), a spacer ring (left light path and right light path share the light path), an objective lens barrel (left light path and right light path share the light path), and two image sensors (a white light sensor and a fluorescence sensor). The main objective lens group includes a liquid lens group and a fixed lens group, which is composed of a filter, a spherical single lens, a three-cemented spherical lens, a double-cemented spherical lens, and a 45° light splitting prism. The light splitting prism is coated so that visible light is reflected and near-infrared light is transmitted.

[0091] Example 4

[0092] Figure 11 Figure 2 is a schematic diagram of a 3D4K white light-fluorescence endoscope imaging system (30°). The endoscope imaging system is composed of the following components in order from the object side to the image side: a front group negative lens (left light path and right light path), a prism group (left light path and right light path), a diaphragm (left light path and right light path share the light path), a main objective lens group (left light path and right light path share the light path), a spacer ring (left light path and right light path share the light path), an objective lens barrel (left light path and right light path share the light path), and two image sensors (a white light sensor and a fluorescence sensor). The main objective lens group includes a liquid lens group and a fixed lens group, which is composed of a filter, a spherical single lens, a three-cemented spherical lens, a double-cemented spherical lens, and a 45° light splitting prism. The light splitting prism is coated so that visible light is reflected and near-infrared light is transmitted.

[0093] The above-mentioned examples 3 and 4 share the light path. The difference between example 3 and example 4 is the prism group. The prism group in example 4 is designed by angle to meet the 30° viewing angle requirement. The liquid lens in examples 1 and 2 is an optical element that realizes dynamic focusing by changing the surface curvature of the liquid. The endoscope imaging system is in focus in the wavelength range of 415 nm-900 nm, with a half-field angle of 48°, an F# of 3.9, and a binocular calibration distance of 50 mm. By adjusting the liquid lens, clear and enlarged images can be observed in the range of 20 mm-200 mm. The MTF imaging curves of the imaging system at 20 mm, 50 mm, and 200 mm are as follows: Figure 12 、 Figure 13 、 Figure 14As shown, the 270 lp / mm resolution of each is greater than 0.2. Compared with the traditional fixed-focus fluorescence endoscope (170 lp / mm), the resolving power of the imaging system is significantly improved.

[0094] Each of the embodiments in the present application is described in a progressive manner, and the same or similar parts between each of the embodiments can be referred to each other. Each of the embodiments focuses on the difference from other embodiments. In particular, for the hardware+program type embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the part of the method embodiments.

[0095] The above describes specific embodiments of the present application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in a different order and still achieve desirable results. Additionally, the processes depicted in the figures do not necessarily require the particular order shown or sequential order in order to achieve the desired results. In some implementations, multitasking and parallel processing can be advantageous.

[0096] Those skilled in the art will also appreciate that, in addition to being implemented in purely computer readable program code means, the controller can be implemented with the method steps being logically programmed to cause the controller to perform the same functions in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers and embedded microcontrollers, etc. Therefore, such a controller can be considered as a hardware component, and the means included therein for implementing various functions can also be considered as structures within the hardware component. Alternatively, the means for implementing various functions can even be considered as both software modules implementing the method and structures within the hardware component.

[0097] The above only describes the embodiments of the present application and is not intended to limit the present application. Those skilled in the art can make various modifications and changes to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the scope of the claims of the present application.

Claims

1. An endoscope, characterized by, The endoscope comprises: two or more light collecting modules for collecting light beams of an observed object from different angles; a beam combining module comprising an optical element with a semi-transparent and semi-reflective surface; the beam combining module is configured to combine the light beams of the observed object collected by the light collecting modules into coaxially propagating light beams through the semi-transparent and semi-reflective surface; an image sensor configured to image the light beams collected by the light collecting modules from different angles of the observed object to obtain stereoscopic image information of the endoscope observed object; the beam combining module further comprises a mirror and / or a prism, and the light beams of the endoscope observed object collected by different light collecting modules are adjusted to the semi-transparent and semi-reflective surface through the mirror and / or the prism in combination with the position of the semi-transparent and semi-reflective surface.

2. The endoscope of claim 1, wherein, The beam combining module comprises a first surface, a second surface, a third surface and a fourth surface; wherein the first surface, the second surface and the third surface are total reflection surfaces, and the fourth surface is a semi-transparent and semi-reflective surface; the first surface and the third surface are configured to reflect the light beams of the observed object collected from different angles; the first surface is configured to reflect the light beams of the observed object to the second surface, and the second surface is configured to reflect the light beams to the fourth surface so that the light beams are transmitted out of the fourth surface; the third surface is configured to reflect the light beams of the observed object to the fourth surface, and the fourth surface reflects the light beams out, and the reflected light beams of the fourth surface coincide with the transmitted light beams.

3. The endoscope of claim 2, wherein, The angle difference between the first surface and the second surface is equal to the angle difference between the third surface and the fourth surface.

4. The endoscope of claim 2, wherein, The values of the two angle differences are determined according to the ratio of the double light path spacing length to the calibration distance, wherein the double light path spacing length is half of the distance between the centers of the front ends of the two light collecting modules, and the calibration distance is the distance between the connecting line of the centers of the front ends of the two light collecting modules and the observed object.

5. The endoscope of claim 1, wherein, The beam combining module comprises a plurality of prisms arranged in the objective lens barrel without gaps; at least one pair of adjacent prisms are coated with a semi-transparent and semi-reflective film layer on the contact surface; and the semi-transparent and semi-reflective film layer is configured to combine the light beams of the observed object collected by the light collecting modules from different angles into coaxially propagating light beams.

6. The endoscope of claim 1, wherein, The beam combining module comprises a first prism, a second prism, a third prism and a fourth prism; the second prism and the third prism are located in the middle region of the cross section of the objective lens barrel and are configured to collect light beams of the observed object from different angles, respectively, and the second prism is adjacent to the third prism; the second prism and the third prism have a first adjacent surface and a second adjacent surface, wherein the first adjacent surface is a total reflection surface, and the second adjacent surface is a semi-transparent and semi-reflective surface; the adjacent surfaces of the first prism and the second prism reflect the light beams of the observed object collected by the second prism to the first adjacent surface, and the first adjacent surface reflects the light beams to the second adjacent surface, and the light beams are transmitted out of the second adjacent surface; the adjacent surfaces of the third prism and the fourth prism reflect the light beams of the observed object collected by the third prism to the second adjacent surface, and the second adjacent surface reflects the light beams out, and the reflected light beams of the second adjacent surface are parallel to the projected light beams.

7. The endoscope of claim 1, wherein, The endoscope further comprises: A liquid lens is arranged on a light propagation path between the beam combination module and the image sensor, and the focal length of the liquid lens is dynamically changed by regulating the shape of the liquid in the liquid lens.

8. The endoscope of claim 1, wherein, The image sensor includes a white light image sensor for white light imaging and a fluorescence sensor for fluorescence imaging. Correspondingly, the endoscope further includes: A beam splitter is arranged on the light propagation path between the beam combination module and the image sensor, and the beam splitter is used to separate the propagation directions of the white light and the fluorescence in the combined light beam, and the separated white light is incident on the white light sensor, and the separated fluorescence is incident on the fluorescence sensor.

9. The endoscope of claim 1, wherein, The endoscope further includes: A parallel flat plate is arranged on the light propagation path between the beam combination module and the image sensor, and the parallel flat plate is used to filter out the excitation light of the fluorescence.

10. The endoscope of claim 1, wherein, The light collection module includes: A front group of negative lenses is used to realize light condensation, adjust the direction of the incident light beam, and adjust the field of view range; An optical switch is arranged at the front end of the front group of negative lenses, and is used to control whether the light collection module collects the light beam of the endoscope observation target.

11. An endoscope assembly comprising: The beam combination module in the endoscope of any one of claims 1 to 10.

12. A surgical microscope system, characterized by The endoscope of any one of claims 1 to 10; An image processing device is used to process the stereoscopic image information of the endoscope observation target. ​

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