Optical system, endoscope, and imaging system

Abstract

An optical system, an endoscope, and an imaging system. The optical system comprises an optical filter assembly and a first lens group comprising a plurality of lenses having focal power. The plurality of lenses are sequentially arranged along an optical axis from an object side to an image side. The first lens group is arranged on one side of the optical filter assembly proximal to the object side, and is used for altering the optical path of light provided by the object side so as to reduce the angle of incidence of light obliquely incident on the optical filter assembly. The optical filter assembly is arranged on one side of the first lens group proximal to the image side, and is used for cutting off light with wavelengths within a preset range.

Description

Optical systems, endoscopes and imaging systems

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 2024110588973, filed on August 2, 2024, and to Chinese Patent Application No. 2024220554540, filed on August 22, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of optical imaging technology, and more particularly to an optical system, an endoscope, and an imaging system. Background Technology

[0004] Minimally invasive surgery has many advantages, including less trauma to patients, reduced intraoperative pain, and shorter postoperative recovery time, and is widely used in various fields of surgical medicine. Medical endoscopes, as the main medical instruments used in minimally invasive surgery, allow doctors to directly observe the tissue morphology of internal organs.

[0005] In clinical surgery, the ability to accurately identify the edges of lesions for precise removal is crucial to surgical success. During the procedure, fluorescently labeling the lesion allows the fluorescent image to reflect its size and outline, while the visible light image reflects the background and location of the lesion. Fusing these two images in real-time provides a complementary view, offering surgeons a clear surgical field and aiding in the identification of lesion shape and other features, significantly improving surgical efficiency. However, the excitation light used to stimulate fluorescence in the lesion is also captured by the image sensor, resulting in image noise in both the final fluorescent and visible light images. This negatively impacts the endoscopic imaging quality and the effectiveness of fluorescence guidance during surgery.

[0006] Application content

[0007] In a first aspect, embodiments of this disclosure provide an optical system including a filter assembly and a first lens group. The first lens group includes a plurality of lenses with optical power, which are arranged sequentially from the object side to the image side along the optical axis. The first lens group is disposed on the side of the filter assembly closer to the object side and is used to change the optical path of the light provided by the object side to reduce the incident angle of the light obliquely incident on the filter assembly. The filter assembly is disposed on the side of the first lens group closer to the image side and is used to block light with wavelengths within a preset range.

[0008] In a second aspect, embodiments of this disclosure provide an optical system for use in an endoscope, comprising: a first sub-optical system for forming a first optical channel; and a second sub-optical system for forming a second optical channel, the second optical channel being arranged side-by-side with the first optical channel; wherein the first sub-optical system and the second sub-optical system share a steering prism.

[0009] Thirdly, embodiments of this disclosure provide an endoscope, including a barrel and the aforementioned optical system, wherein the optical system is disposed within the barrel.

[0010] Fourthly, embodiments of this disclosure provide an imaging system, comprising: an optical system, wherein the optical system is as described in any of the preceding embodiments, the optical system being used to receive light signals from a target area; and an image sensor disposed on the image side of the optical system, the image sensor being used to convert the light signals transmitted via the optical system into electrical signals to acquire an image of the target area.

[0011] Details of one or more embodiments of this application are set forth in the following drawings and description. Other features, objects, and advantages of this application will become apparent from the specification, drawings, and claims. Attached Figure Description

[0012] The accompanying drawings, which are incorporated in and form part of this disclosure, illustrate embodiments consistent with this disclosure and, together with the description, serve to illustrate the technical solutions of this disclosure.

[0013] Figure 1 is a schematic diagram of an optical system according to an embodiment of the present disclosure.

[0014] Figure 2 is a schematic diagram of the transmittance spectrum curve of the filter component according to an embodiment of the present disclosure.

[0015] Figure 3 is a first structural diagram of the optical system according to an embodiment of the present disclosure.

[0016] Figure 4 is a second structural diagram of the optical system according to an embodiment of the present disclosure.

[0017] Figure 5 is a third structural diagram of the optical system according to an embodiment of this disclosure.

[0018] Figure 6 is a fourth structural diagram of the optical system according to an embodiment of this disclosure.

[0019] Figure 7 is a fifth structural diagram of the optical system according to an embodiment of the present disclosure.

[0020] Figure 8 is a structural diagram of the first element in the optical system shown in Figure 4.

[0021] Figure 9 is a schematic diagram of the optical system of this disclosure applied to an endoscope.

[0022] Figure 10 is a structural diagram of an imaging system according to an embodiment of the present disclosure.

[0023] Figure 11 is a schematic diagram of the response intensity of the image sensor of this disclosure to light of different wavelengths.

[0024] Figure 12 is a structural diagram of an endoscope system according to an embodiment of the present disclosure.

[0025] Figure 13 is a structural diagram of a surgical robot system according to an embodiment of the present disclosure.

[0026] Detailed Implementation of This Application

[0027] The technical solutions in the embodiments of this disclosure will be clearly and completely described herein with reference to the accompanying drawings. In the following description, when referring to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0028] If this disclosure uses terms relating to directional indications or positional relationships (e.g., up, down, left, right, front, back, inside, outside, top, bottom, center, vertical, horizontal, longitudinal, transverse, length, width, counterclockwise, clockwise, axial, radial, circumferential, etc.), such terms are only used to explain the relative positional relationships and movements between components in a specific posture (as shown in the attached figures); if the specific posture changes, the directional indications or positional relationships will also change accordingly. Furthermore, terms such as "first" and "second" in this disclosure are used only for descriptive convenience and should not be construed as indicating or implying relative importance.

[0029] In related technologies, for objects within a target area that are difficult to observe directly with the naked eye, a specially designed imaging system can be used to excite and detect the special light emitted by the object, thereby achieving visualization. In practical applications, the target area may be illuminated by multiple light sources, providing various types of light. Based on these multiple light sources, the target area can be imaged to obtain an image of the target area, thus enabling visualization of objects within the target area. The target area may include multiple objects, and different objects have different light absorption and reflection characteristics, resulting in different image signals in the image. Based on the differences in the image signals corresponding to the regions of each object in the image, the regions corresponding to each object can be distinguished from the image.

[0030] One specific implementation of the aforementioned visualization process is fluorescence imaging. Fluorescence imaging refers to the method of visualizing objects that cannot be directly distinguished by labeling them with fluorescent dyes and then using a specially designed imaging system to excite and detect fluorescence. Currently, fluorescence imaging technology has applications in many fields. In some applications, fluorescent dyes can be injected into the target area through injection or application. The target area is then illuminated by a visible light source and an excitation light source. The target area reflects visible light under the illumination of the visible light source and emits fluorescence under the illumination of the excitation light source. Based on the visible light and fluorescence provided by the target area, visible light and fluorescence images of the target area can be obtained and analyzed. For example, when fluorescence imaging technology is applied to the field of surgery, the target area can be the surgical area. Images of the target area can help doctors identify normal and diseased tissues in the patient's body, thereby improving surgical accuracy.

[0031] The target area may include multiple objects, each with varying degrees of absorption of fluorescent dyes. Therefore, the intensity of fluorescence emitted by different objects under excitation light may also differ. For example, in surgery, multiple objects may include normal tissue and diseased tissue. The surgeon's ability to accurately distinguish the edges of diseased tissue for precise removal is crucial to surgical success. Compared to normal tissue, diseased tissue typically absorbs fluorescent dyes at a higher rate. Consequently, normal tissue emits weaker fluorescence under excitation light, while diseased tissue emits stronger fluorescence, resulting in different image signals for the areas corresponding to normal tissue and diseased tissue in the target area image. During surgery, by fluorescently labeling the target area, the fluorescent image reflects information such as the size and contour of the diseased tissue, while the visible light image reflects information such as the tissue background and scene location. By fusing these two feature information and displaying the fluorescent and visible light images of the target area in real time, the shortcomings of individual fluorescent and visible light images can be compensated for, providing the surgeon with a better surgical field of vision. This helps the surgeon identify the shape and other features of the diseased tissue, significantly improving surgical efficiency. However, the excitation light used to stimulate fluorescence in the target area is also captured by the image sensor, resulting in image noise caused by the excitation light in the final fluorescence image and visible light image. This leads to poor imaging quality of the target area and affects the fluorescence guidance effect during surgery.

[0032] It is understood that the above fluorescence imaging scenarios are merely illustrative examples. Other methods can be used to achieve visualization in other application scenarios, which will not be listed here. For ease of description, fluorescence imaging technology will be used as an example below.

[0033] To reduce image noise caused by excitation light in the image of the target area and improve the imaging quality of the target area, this disclosure provides an optical system. This optical system can be applied to various optical lenses, such as those used in fluorescence imaging scenarios, specifically, medical endoscopes used in minimally invasive surgery. Please refer to FIG1, which is a schematic diagram of the optical system according to an embodiment of this disclosure. The optical system 11 may include a filter assembly 110 and a first lens group 111.

[0034] The optical system 11 has an optical axis C, which passes through the center of the optical system 11 and serves as the axis of symmetry of the optical system 11. The first lens group 111 includes multiple lenses with optical power, arranged sequentially from the object side to the image side along the optical axis C. The first lens group 111 is positioned on the side of the filter assembly 110 closer to the object side, and is used to change the optical path of the light provided by the object side, thereby reducing the incident angle of the light incident on the filter assembly 110. This facilitates the filter assembly 110 in blocking unwanted light rays, such as excitation light, from the light rays incident on the filter assembly 110. The filter assembly 110 is positioned on the side of the first lens group 111 closer to the image side, and is used to block light rays with wavelengths within a preset range, thereby filtering out unwanted light rays, such as excitation light, from the light rays exiting the first lens group 111.

[0035] For filter components used in fluorescence imaging, it is necessary to ensure high transmittance of visible light and fluorescence while blocking the excitation light. The higher the cutoff depth of the excitation light, the less image noise caused by the excitation light. Filter components used for fluorescence imaging are usually reflective filters, and the excitation light incident on its surface is reflected. If the incident angle of light perpendicular to its surface is taken as 0 degrees, as the incident angle increases, its passband and cutoff band will shift towards shorter wavelengths, which is called blue shift. In this embodiment, the fluorescence emitted by indocyanine green (ICG) reagent is irradiated with excitation light of 785 nm as an example. The peak wavelength of fluorescence emitted by ICG is approximately 815 nm-830 nm. It is necessary to ensure high fluorescence transmittance while completely blocking the excitation light at the 785 nm wavelength. The higher the fluorescence transmittance, the higher the fluorescence intensity that the image sensor can sense, and the more obvious the fluorescence effect of the final image. However, due to the blue shift problem, as shown in Figure 2, which is a schematic diagram of the transmittance spectrum curve of the filter component in this embodiment, a blue shift occurs. At an incident angle of 0 degrees, the fluorescence transmittance at 815nm wavelength is greater than 90%, and the excitation cutoff depth at 785nm wavelength is greater than OD6. At an incident angle of 10 degrees, the excitation cutoff depth at 785nm wavelength decreases to approximately OD4; at an incident angle of 15 degrees, the excitation cutoff depth at 785nm wavelength decreases to approximately OD3. When the excitation cutoff depth is less than OD4, because the wavelengths of the excitation light and fluorescence are close and both belong to infrared light, they will be sensed by the same signal channel of the image sensor (such as the red signal channel). Therefore, the uncut excitation light will be directly collected by the image sensor as fluorescence, causing stray light interference to fluorescence imaging. The excitation light with an incident angle greater than 15 degrees transmits more energy through the filter component, resulting in stronger interference.

[0036] Therefore, if the incident angle of light incident on the filter assembly can be reduced in the optical design, or even the incident angle of all light incident on the filter assembly can be controlled within a preset angle, such as 15 degrees, it is possible to achieve high fluorescence transmittance while blocking excitation light to a certain extent, or even completely blocking excitation light. In the optical system 11 provided in this embodiment: by setting a first lens group 111 in the optical path before the filter assembly 110, the incident angle of light incident on the filter assembly 110 is reduced, so that the filter assembly 110 can block unwanted light, such as excitation light, to a certain extent while ensuring the required light, such as high fluorescence transmittance; and by setting a filter assembly 110 in the optical path after the first lens group 111 and before the image side, the light emitted from the first lens group 111 is filtered, blocking light with wavelengths within a preset range, such as excitation light, to a certain extent, reducing unwanted light, such as excitation light, in the image side, thereby reducing image noise in the image side, improving image quality, and improving performance.

[0037] In some embodiments, the optical power of the first lens group 111 is positive optical power. The first lens group 111 is used to reduce the incident angle of light rays from the tilted incident filter assembly 110, so that the incident angle of all light rays incident on the filter assembly 110 is less than a preset angle, such as less than 10 degrees, thereby ensuring that the filter assembly 110 completely cuts off the excitation light in the light rays exiting the first lens group 111. However, the preset angle of 10 degrees is only an example and is not limited to 10 degrees. It can be understood that the preset angle may vary depending on the different requirements for the cutoff depth of the excitation light in different application scenarios.

[0038] It should be noted that the optical power of the lens group is calculated by a certain algorithm for the optical power of each lens in the lens group. This algorithm is a known technology and will not be described in detail here. In this embodiment, the optical power of the first lens group 111 is calculated by the same algorithm for the optical power of each lens in the first lens group 111. When the optical power of the lens group is involved in the various embodiments of this disclosure, it is understood in the same way as in this embodiment, and will not be described in detail below.

[0039] In some embodiments, the optical system 11 may further include a second lens group 112 and a third lens group 113. Please refer to Figures 3 and 4. Figure 3 is a first structural diagram of the optical system according to an embodiment of the present disclosure, and Figure 4 is a second structural diagram of the optical system according to an embodiment of the present disclosure. The second lens group 112 is disposed near the object side, and the third lens group 113 is disposed near the image side. The filter assembly 110 and the first lens group 111 are disposed between the second lens group 112 and the third lens group 113. In other words, the second lens group 112, the first lens group 111, the filter assembly 110, and the third lens group 113 are arranged sequentially along the optical axis C from the object side to the image side. The second lens group 112 has a negative optical power, and the third lens group 113 has a negative optical power, but the optical power of the optical path formed by the first lens group 111, the filter assembly 110, and the third lens group 113 is a positive optical power.

[0040] In some embodiments, the focal length of the first lens group 111 is within a first range, the focal length of the second lens group 112 is within a second range, and the focal length of the third lens group 113 is within a third range. For example, the numerical relationship between the focal lengths F1 of the first lens group 111, F2 of the second lens group 112, and F3 of the third lens group 113 is shown in Table 1 below. However, Table 1 is only an example, and the focal lengths F1 of the first lens group 111, F2 of the second lens group 112, and F3 of the third lens group 113 are not limited to the values ​​shown in Table 1. It can be understood that, according to the different spectral characteristics corresponding to different filter components 110 and the different requirements for the cutoff depth of the excitation light in different application scenarios, the focal lengths F1 of the first lens group 111, F2 of the second lens group 112, and F3 of the third lens group 113 can vary with the specific scenario.

[0041] Table 1

[0042] The first lens group 111 may include at least one lens and / or cemented lens group with positive optical power. For example, the first lens group 111 may include multiple lenses with positive optical power, or it may include multiple cemented lens groups with positive optical power. The first lens group 111 may also include both one or more lenses with positive optical power and one or more cemented lens groups with positive optical power. The at least one lens and / or cemented lens group with positive optical power is arranged sequentially along the optical axis C from the object side to the image side. The lens or cemented lens group closest to the image side in the first lens group 111 is disposed on the side of the filter assembly 110 closest to the object side, so that the filter assembly 110 is located between the lens or cemented lens group closest to the image side in the first lens group 111 and the third lens group 113.

[0043] In some embodiments, the first lens group 111 may specifically include a first lens 1111, a second lens 1112, a third lens 1113, and a fourth lens 1114 arranged sequentially from the object side to the image side along the optical axis C. The first lens 1111, the second lens 1112, and the third lens 1113 are all lenses with positive optical power, and the fourth lens 1114 is a lens with negative optical power.

[0044] The first lens 1111, the second lens 1112, and the third lens 1113 can be biconvex lenses. For example, the object-side surface and the image-side surface of the first lens 1111, the second lens 1112, and the third lens 1113 can both be convex surfaces. The first lens 1111, the second lens 1112, and the third lens 1113 can also be plano-convex lenses. For example, one side of the object-side surface and the image-side surface of the first lens 1111, the second lens 1112, and the third lens 1113 can be convex and the other side can be planar. The first lens 1111, the second lens 1112, and the third lens 1113 can also be concave-convex lenses. For example, one side of the object-side surface and the image-side surface of the first lens 1111, the second lens 1112, and the third lens 1113 can be convex and the other side can be concave. The fourth lens 1114 can be a biconcave lens, a plano-concave lens, or a convex-concave lens. For example, the object-side surface and the image-side surface of the fourth lens 1114 can both be concave, or one side of the object-side surface and the other side can be concave and the other side can be planar, or one side of the object-side surface and the other side can be concave and the other side can be convex.

[0045] In this embodiment, the image-side surface of the third lens 1113 is adapted to the shape of the object-side surface of the fourth lens 1114 so that the third lens 1113 and the fourth lens 1114 can form a cemented lens group. For example, the image-side surface of the third lens 1113 can be convex, and the object-side surface of the fourth lens 1114 can be concave. It is understood that the image-side surface of the third lens 1113 can also be planar or concave, and the object-side surface of the fourth lens 1114 can also be planar or convex, as long as the shape of the image-side surface of the third lens 1113 and the object-side surface of the fourth lens 1114 is adapted. In this embodiment, the cemented lens group closest to the image side in the first lens group 111 is the cemented lens group composed of the third lens 1113 and the fourth lens 1114, and the lens closest to the image side in the first lens group 111 is the fourth lens 1114. Therefore, the filter assembly 110 is disposed on the side of the fourth lens 1114 closest to the image side and is located between the fourth lens 1114 and the third lens group 113.

[0046] The first lens group 111, comprising a first lens 1111, a second lens 1112, a third lens 1113, and a fourth lens 1114, is merely illustrative; the specific structure of the first lens group 111 is not limited to that described in the previous embodiment or shown in Figures 3 and 4. It is understood that the number of lenses included in the first lens group 111 and the specific structure of each lens can also have other variations.

[0047] For example, the first lens group 111 may include a cemented lens group consisting of the first lens 1111, the third lens 1113, and the fourth lens 1114, but does not include the second lens 1112. As shown in FIG5, FIG5 is a third structural diagram of the optical system according to an embodiment of the present disclosure. In the case shown in FIG5, the first lens 1111 is a lens with positive optical power whose object-side and image-side are both convex, the third lens 1113 is a lens with positive optical power whose object-side and image-side are both convex, and the fourth lens 1114 is a lens with negative optical power whose object-side and image-side are concave and convex, respectively.

[0048] For example, the first lens group 111 may include an additional lens 1110, the first lens 1111, and the second lens 1112, but does not include the cemented lens group composed of the third lens 1113 and the fourth lens 1114. As shown in FIG6, FIG6 is a fourth structural diagram of the optical system according to an embodiment of the present disclosure. In the case shown in FIG6, the additional lens 1110 is a lens with positive optical power whose object-side surface and image-side surface are respectively planar and convex, the first lens 1111 is a lens with positive optical power whose object-side surface and image-side surface are respectively planar and convex, and the second lens 1112 is a lens with positive optical power whose object-side surface and image-side surface are both convex.

[0049] For example, the first lens group 111 may include an additional lens 1110, a first lens 1111, a second lens 1112, a third lens 1113, and a fourth lens 1114 forming a cemented lens group. As shown in FIG7, FIG7 is a fifth structural diagram of the optical system according to an embodiment of the present disclosure. In the case shown in FIG7, the additional lens 1110 is a lens with positive optical power whose object-side surface and image-side surface are respectively planar and convex; the first lens 1111 is a lens with positive optical power whose object-side surface and image-side surface are respectively planar and convex; the second lens 1112 is a lens with positive optical power whose object-side surface and image-side surface are both convex; the third lens 1113 is a lens with positive optical power whose object-side surface and image-side surface are both convex; and the fourth lens 1114 is a lens with negative optical power whose object-side surface and image-side surface are respectively concave and planar.

[0050] In some embodiments, the optical system 11 may further include an aperture stop 114. Please continue referring to FIG1. ​​The aperture stop 114 is disposed between the first lens group 111 and the second lens group 112. The aperture stop 114 can be referred to in the description of aperture stops in the field of optics, and will not be repeated here. The second lens group 112 may include a first element 1121 and a fifth lens 1125. Wherein: the first element 1121 is a transparent optical element with zero optical power. For example, the first element 1121 can be a flat glass, or the first element 1121 can be a prism; the fifth lens 1125 is a lens with negative optical power. The specific shape of the fifth lens 1125 can be referred to the fourth lens 1114, and will not be repeated here.

[0051] In this embodiment, the fifth lens 1125 is positioned close to the object side to converge the light rays incident on it, thereby reducing the angle of incidence of the light rays after exiting the fifth lens 1125 and entering the first element 1121. The first element 1121 is positioned close to the aperture stop 114 to guide the light rays exiting the fifth lens 1125 into the first element 1121 and then through the aperture stop 114. In this embodiment, by setting the second lens group 112 before the aperture stop 114, the light rays provided by the object side can be converged, reducing the height of the light rays incident on the lens groups after the aperture stop 114, such as the first lens group 111 and the third lens group 113, which is beneficial for correcting aberrations.

[0052] In some embodiments, the principal axis of the fifth lens 1125 is arranged parallel to the optical axis C, and the object-side and image-side surfaces of the first element 1121 are also arranged perpendicular to the optical axis C, as shown in FIG3. In this embodiment, the normal of the object-side surface of the fifth lens 1125 is parallel to the optical axis C, the viewing angle of the optical system 11 is 0 degrees, and the first element 1121 can guide the light rays exiting the fifth lens 1125 to enter the first element 1121 and then pass through the aperture 114 without changing the optical path of the light rays exiting the fifth lens 1125. The first element 1121 can be a flat glass plate.

[0053] In some embodiments, the principal axis of the fifth lens 1125 is inclined to the optical axis C, and the object-side surface of the first element 1121 is inclined to the optical axis C, while the image-side surface is perpendicular to the optical axis C, as shown in FIG4. In this embodiment, there is a certain angle, such as 30 degrees, between the normal of the object-side surface of the fifth lens 1125 and the optical axis C. The viewing angle of the optical system 11 is not 0 degrees, but 30 degrees. The first element 1121 needs to change the optical path of the light rays exiting the fifth lens 1125 in order to guide the light rays exiting the fifth lens 1125 into the first element 1121 and then through the aperture 114. The first element 1121 can be a prism.

[0054] The first element 1121 may include a first prism 1122 and a second prism 1123. Please refer to Figure 8, which is a structural diagram of the first element in the optical system shown in Figure 4. The first prism 1122 guides the light rays exiting the fifth lens 1125 to the second prism 1123. The incident surface of the first prism 1122 is parallel to and opposite to the exit surface of the fifth lens 1125 to receive the light rays exiting from the exit surface of the fifth lens 1125; the exit surface of the first prism 1122 is inclined to the optical axis C to transmit the light rays incident on the first prism 1122 to the second prism 1123. The second prism 1123 guides the light rays exiting the first prism 1122 to the aperture 114. The incident surface of the second prism 1123 is parallel to and opposite to the exit surface of the first prism 1122 to receive light rays emitted from the exit surface of the first prism 1122; the exit surface of the second prism 1123 is perpendicular to the optical axis C to transmit light rays incident on the second prism 1123 to the aperture 114.

[0055] Specifically, the second prism 1123 has a first surface S1, a second surface S2, and a third surface S3 arranged adjacent to each other. The first surface S1 is the incident surface of the second prism 1123, used to receive light emitted from the first prism 1122 and transmit it to the second surface S2, and to receive light reflected from the second surface S2 and reflect it completely to the third surface S3; the second surface S2 is used to receive light transmitted from the first surface S1 and reflect it completely to the first surface S1; the third surface S3 is the exit surface of the second prism 1123, used to receive light reflected from the first surface S1 and transmit it to the first lens group 111.

[0056] The second lens group 112 includes a first element 1121 and a fifth lens 1125 as an example. The specific structure of the second lens group 112 is not limited to that described in this embodiment or shown in Figures 3 and 4. It is understood that the number of optical elements included in the second lens group 112 and the specific structure of each optical element can be varied. For example, the second lens group 112 may also include a cemented lens group consisting of a first element 1121 and two lenses with optical power, but without the fifth lens 1125. The second lens group 112 may also include a first element 1121, a fifth lens 1125, and another lens with optical power, which may be disposed on the side of the fifth lens 1125 near the object side or between the fifth lens 1125 and the first element 1121.

[0057] The third lens group 113 may include a sixth lens 1136. Specifically, the sixth lens 113 is positioned closer to the image side of the third lens group 113, and the filter assembly 110 is positioned between the first lens group 111 and the third lens group 113, specifically between the fourth lens 1114 and the sixth lens 1136. The sixth lens 1136 is a lens with negative optical power, used to adjust the light emitted from the filter assembly 110 to improve the image quality and image effect at the image side. The shape of the sixth lens 1136 can be referenced to that of the fourth lens 1114, and will not be described further here.

[0058] The inclusion of the sixth lens 1136 in the third lens group 113 is merely illustrative, and the specific structure of the third lens group 113 is not limited to that described in this embodiment or shown in Figures 3 and 4. It is understood that the number of lenses included in the third lens group 113 and the specific structure of each lens can have other variations. For example, the third lens group 113 may also include the sixth lens 1136 and another lens with optical power. The third lens group 113 may also include a cemented lens group consisting of the sixth lens 1136 and two lenses with optical power, as shown in Figure 6. This lens or the cemented lens group may be disposed on the side of the sixth lens 1136 near the image side or between the sixth lens 1136 and the filter assembly 110.

[0059] The filter assembly 110 may include a filter 1101 and a second element 1102. Specifically, the second element 1102 is disposed between the first lens group 111 and the third lens group 113, and more specifically, between the fourth lens 1114 and the sixth lens 1136. The filter 1101 is disposed on the surface of the second element 1102 facing the fourth lens 1114 and / or facing the sixth lens 1136. The filter 1101 is a reflective filter, which blocks unwanted light by reflecting it. The second element 1102 is a transparent optical element with zero optical power; for example, the second element 1102 can be a flat glass plate. The inclusion of the filter 1101 and the second element 1102 in the filter assembly 110 is merely illustrative, and the specific structure of the filter assembly 110 is not limited to that described in this embodiment. It is understood that the specific structure of the filter assembly 110 may have other variations. For example, the filter assembly 110 may include only the filter 1101 without the second element 1102, and select a fourth lens 1114 with a plane image side and / or a sixth lens 1136 with a plane object side, and directly place the filter 1101 on the image side of the fourth lens 1114 and / or the object side of the sixth lens 1136.

[0060] The optical system provided in this embodiment, in the optical path from the object side to the image side: light first passes through the second lens group 112, where the fifth lens 1125 of the second lens group 112 converges the light provided from the object side, reducing the height of the light from the lens group after the incident aperture 114, which is beneficial for correcting aberrations. The first element 1121 of the second lens group 112 guides the light exiting the fifth lens 1125 through the aperture 114. The light then passes through the first lens group 111, where the first lens 1111, second lens 1112, third lens 1113, and fourth lens 1114 of the first lens group 111 deflect the light after passing through the aperture 114, thereby reducing the incident light. The incident angle of all light rays in the filter assembly 110 is controlled within a preset angle, so that the filter assembly 110 can block unwanted light rays, such as excitation light, while ensuring the required light rays, such as high fluorescence transmittance. The light rays then pass through the filter assembly 110, and the filter 1101 of the filter assembly 110 filters the light rays incident on the filter assembly 110 to block unwanted light rays and prevent unwanted light rays from forming images on the image side, thereby reducing image noise on the image side. Finally, the light rays pass through the third lens group 113, and the sixth lens 1136 of the third lens group 113 adjusts the light rays exiting the filter assembly 110, thereby improving the image quality and image effect on the image side.

[0061] As a precision medical device integrating optics, mechanics, and electronics, the core function of an endoscope relies on the imaging quality of its optical system. It transmits optical signals from the lesion area within the body to the imaging element via an optical lens, which then processes the image and presents it to the doctor, enabling real-time, clear observation of the surgical area. Therefore, the rationality of the optical system's design not only determines key indicators such as image clarity and signal-to-noise ratio, but also directly relates to the endoscope's structural dimensions, manufacturing costs, and assembly difficulty.

[0062] However, endoscopes in related technologies have the following shortcomings in optical system design and application: Endoscopes typically include two independent sub-optical systems, resulting in a large outer diameter, usually above 10mm, leading to larger surgical incisions and hindering postoperative recovery. The lenses used in endoscopes typically have an outer diameter below 2.6mm, or even below 2.0mm, increasing the difficulty of lens manufacturing, reducing yield, and thus increasing the cost of mass-producing lenses. Furthermore, because existing endoscopes contain two independent sub-optical systems, each sub-optical system must be assembled separately before being assembled and calibrated using structural fixing, optical bonding, or both. For endoscopes with non-0° viewing angles, the binocular aberration introduced by the prism is difficult to guarantee.

[0063] To address this, an optical system 11 for use in endoscopes is proposed to improve or overcome at least one of the aforementioned problems.

[0064] As shown in Figure 9, the optical system 11 includes a first sub-optical system 11a and a second sub-optical system 11b. The first sub-optical system 11a forms a first optical channel 111a, and the second sub-optical system 11b forms a second optical channel 111b. The second optical channel 111b is arranged side by side with the first optical channel 111a. The first sub-optical system 11a and the second sub-optical system 11b share a steering prism 31.

[0065] When the optical system 11 is working, light can be transmitted through the first optical channel 111a and the second optical channel 111b, respectively. The second optical channel 111b is arranged side by side with the first optical channel 111a. The first optical channel 111a and the second optical channel 111b share a steering prism 31, and the light is deflected by the steering prism 31 when it is transmitted through the first optical channel 111a and the second optical channel 111b.

[0066] The two optical systems share a single steering prism 31 and a common endoscope tube. The reduced center-to-center distance between the two optical channels results in a smaller outer diameter of the endoscope tube, allowing the endoscope to be designed with a smaller overall size. This meets the clinical needs of surgical robots, resulting in smaller surgical incisions and better postoperative recovery compared to endoscopes with an outer diameter of 10mm or more.

[0067] Because the steering prism 31 is shared, the thickness of the isolation walls between the two sub-optical systems can be reduced, allowing for a smaller outer diameter of the lens barrel. This, in turn, enables a corresponding increase in the outer diameter of the lens in the optical design, ensuring a smaller outer diameter of the lens barrel. Increasing the outer diameter of the lens helps reduce the difficulty of lens processing, improves processing accuracy and yield, while ensuring good optical imaging quality and reducing batch costs.

[0068] In addition, the two optical systems are integrated into a whole. By assembling and calibrating this whole, the binocular aberration caused by the processing and assembly deviation of the independent prisms in the traditional solution can be eliminated, which greatly improves the 3D pairing yield.

[0069] Optionally, the portion of the steering prism 31 belonging to the first sub-optical system 11a and the portion belonging to the second sub-optical system 11b can have the same thickness. The steering prism 31 has a first mirror surface 32 and a second mirror surface 33, with the first mirror surface 32 facing away from the second mirror surface 33 in the thickness direction of the steering prism 31. The first mirror surface 32 is planar, and the second mirror surface 33 is also planar. With this arrangement, the steering angles of the first optical channel 111a and the second optical channel 111b can be designed to be the same. Of course, if needed and / or desired, the portion of the steering prism 31 belonging to the first sub-optical system 11a and the portion belonging to the second sub-optical system 11b can have different thicknesses. The first mirror surface 32 and the second mirror surface 33 are not arranged parallel; to achieve steering, the first mirror surface 32 and the second mirror surface 33 have an included angle α, where 0 < α ≤ 90°. The included angle α can be a suitable angle such as 5°, 10°, 12°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, or 90°. Therefore, an endoscope can have a non-zero viewing angle of less than or equal to 90°, and the viewing angle of the endoscope can be 5°, 10°, 12°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, or 90°.

[0070] Optionally, the central axis of the second optical channel 111b is parallel to the central axis of the first optical channel 111a. In this way, light can propagate along parallel optical path directions D in the two optical channels.

[0071] In some embodiments, the first sub-optical system 11a includes a first lens group 111 and a second lens group 112. The first lens group 111 is disposed close to the object side and is used to change the optical path of the light provided by the object side. The second lens group 112 is disposed on the side of the steering prism 31 away from the first lens group 111 and is disposed close to the object side.

[0072] The second sub-optical system 11b includes a third lens group 113 and a fourth lens group 114, which are located on opposite sides of the steering prism 31. The first lens group 111 and the third lens group 113 are located on the same side of the steering prism 31, and the second lens group 112 and the fourth lens group 114 are located on the same side of the steering prism 31.

[0073] Each of the lens groups 111, 112, 113, and 114 can include two or more lenses, or it can consist of a single lens. The first lens group 111 and the third lens group 113 are located on the same side of the steering prism 31, as are the second and fourth lens groups 112 and 114. The first optical channel 111a and the second optical channel 111b are formed by the lens groups both before and after the steering, allowing for the selection of different types of lenses according to the different light requirements before and after the steering.

[0074] Furthermore, the core technical features of the optical system 11, such as the optimized design of the filter component 110 and the control of the optical path angle, can also be adapted to the dual optical channel design of the endoscope optical system 11. For example, it can be applied to the first sub-optical system 11a and / or the second sub-optical system 11b of the endoscope optical system 11.

[0075] In some embodiments, the endoscope optical system 11 further includes a filter assembly 110, which is disposed on the side of the first lens group 111 and / or the third lens group 113 near the image side, for blocking light with wavelengths within a preset range.

[0076] In some embodiments, the filter assembly 110 includes a second element 1102 and a filter 1101. The second element 1102 is a transparent optical element and the optical power of the second element 1102 is zero. The filter 1101 is disposed on the surface of the second element 1102 and is used to reflect light with wavelengths within a preset range to block light with wavelengths within the preset range.

[0077] In some embodiments, the endoscope optical system 11 further includes an aperture 114, which is disposed between the first lens group 111 and the second lens group 112 and / or between the third lens group 113 and the fourth lens group 114. A steering prism 31 is disposed near the aperture 14 to guide the light rays emitted from the first lens group 111 and / or the third lens group 113 through the aperture 14.

[0078] In some embodiments, the steering prism 31 includes a first prism 1122 and a second prism 1123. The incident surface of the first prism 1122 is parallel to and opposite to the image-side surface of the first lens group 111 and / or the third lens group 113. The incident surface of the second prism 1123 is parallel to and opposite to the exit surface of the first prism 1122, and the exit surface is perpendicular to the optical axis. The second prism 1123 is used to make light rays that are perpendicularly incident on the first lens group 111 and / or the third lens group 113 enter the second prism 1123 and exit the second prism 1123 perpendicularly.

[0079] Furthermore, the second prism 1123 has a first surface S1, a second surface, and a third surface arranged adjacent to each other; the first surface S1 is the incident surface of the second prism 1123, used to receive light emitted from the first prism 1122 and transmit it to the second surface S2, and to receive light reflected from the second surface S2 and reflect it completely to the third surface S3; the second surface S2 is used to receive light transmitted from the first surface S1 and reflect it completely to the first surface S1; the third surface S3 is the exit surface of the second prism 1123, used to receive light reflected from the first surface S1 and transmit it to the first lens group 111 and / or the third lens group 113.

[0080] In some embodiments, the second lens group 112 and the fourth lens group 114 are located on the side where the first mirror 32 is located, and the first lens group 111 and the third lens group 113 are located on the side where the second mirror 33 is located.

[0081] In some embodiments, the second lens group 112 is located at the near end of the steering prism 31 along the optical path direction D, and the second lens group 112 includes at least one negative power lens. The first lens group 111 is located at the far end of the steering prism 31 along the optical path direction, and the first lens group 111 includes at least one positive power lens.

[0082] In some embodiments, the second lens group 112 includes a plano-concave negative power lens.

[0083] In some embodiments, along the optical path direction D from the near end to the far end, the first lens group 111 includes a first positive power lens group 41, a second positive power lens group 42, a third positive power lens group 43, and a fourth negative power lens group 44.

[0084] In this configuration, the second lens group 112 is located near the optical path direction D of the steering prism 31, and the first lens group 111 is located at the far end of the optical path direction D of the steering prism 31. The third lens group 113 is arranged and constructed identically to the first lens group 111, and the fourth lens group 114 is arranged and constructed identically to the third lens group 113. Specifically, in terms of arrangement, the fourth lens group 114 is located near the optical path direction D of the steering prism 31, and the third lens group 113 is located at the far end of the optical path direction D of the steering prism 31. For the sake of simplicity, the following description uses the first lens group 111 and the second lens group 112 as examples in terms of construction.

[0085] The second lens group 112 includes at least one negative power lens, and the first lens group 111 includes at least one positive power lens. In some embodiments, the second lens group 112 includes a plano-concave negative power lens. The first lens group 111 includes a first positive power lens group 41, a second positive power lens group 42, a third positive power lens group 43, and a fourth negative power lens group 44. The first positive power lens group 41, the second positive power lens group 42, the third positive power lens group 43, and the fourth negative power lens group 44 are arranged sequentially along the optical path direction D from the near end to the far end.

[0086] Of course, if needed and / or desired, any of these focal power lens groups can be replaced by a single focal power lens. Optionally, the first positive focal power lens group 41 can be replaced by a single positive focal power lens, the second positive focal power lens group 42 can be replaced by a single positive focal power lens, the third positive focal power lens group 43 can be replaced by a single positive focal power lens, and / or the fourth negative focal power lens group 44 can be replaced by a single negative focal power lens.

[0087] According to another aspect of this application, an endoscope is provided, the endoscope including a tube and the aforementioned optical system 11, the optical system 11 being disposed within the tube. Since the two optical channels in the optical system 11 share a single steering prism 31, the outer diameter of the tube can be set to be less than 8.8 mm.

[0088] This disclosure also provides an imaging system. Please refer to FIG10, which is a structural diagram of the imaging system according to an embodiment of this disclosure. The imaging system 10 may include a light source 101, an imaging module 102, and an image processor 103.

[0089] The light source 101 includes a first light source 101a and a second light source 101b capable of emitting light of different wavelengths. Both the first light source 101a and the second light source 101b can illuminate the target region S. The target region S receives first light under the illumination of the first light source 101a and second light under the illumination of the second light source 101b, and the first light and the second light have different wavelengths. The target region S includes a first object and a second object, and the first object and the second object provide light with different spectral characteristics under the illumination of the second light source 101b.

[0090] In some embodiments, the first light source 101a may be a visible light source, and the second light source 101b may be an excitation light source. The target region S provides visible light under the illumination of the visible light source and fluorescence under the illumination of the excitation light source, with the visible light and fluorescence having different wavelengths. However, the first light source 101a being a visible light source and the second light source 101b being an excitation light source is merely illustrative, and the first light source 101a and the second light source 101b are not limited to being a visible light source and an excitation light source, respectively. In the following description, the embodiments of this disclosure will be described using the first light source 101a as a visible light source and the second light source 101b as an excitation light source as examples. It can be understood that the principles of the embodiments of this disclosure are the same as when the first light source 101a and the second light source 101b are different light sources.

[0091] In some embodiments, the visible light source 101a can emit visible light La with a wavelength in the range of 380nm-780nm. Different wavelengths of visible light La can be selected according to different needs. For example, visible light La can be light with a wavelength between 600nm-660nm, such as red light; visible light La can also be light with a wavelength between 550nm-650nm, such as yellow light or amber light; and visible light La can also be light with a wavelength between 380nm-470nm, such as blue light.

[0092] In some embodiments, the excitation light source 101b can emit excitation light Lb, which can be any excitation light that can cause the target region S to emit fluorescence, such as infrared light, near-infrared light, or ultraviolet light.

[0093] When the target region S is irradiated by visible light La emitted from visible light source 101a, it can reflect visible light Lax, which is the first light. When the target region S is irradiated by excitation light Lb emitted from excitation light source 101b, it can also emit fluorescence Lby, which is the second light. The visible light Lax and the fluorescence Lby have different wavelengths. For example, the wavelength of visible light Lax is between 380nm and 780nm, while the wavelength of fluorescence Lby is between 800nm ​​and 900nm. It is understood that the values ​​in the above embodiments are merely illustrative and are not intended to limit this disclosure.

[0094] The target region S includes a first object O1 and a second object O2. Both the first object O1 and the second object O2 reflect visible light Lax when illuminated by visible light La emitted by visible light source 101a. The first object O1 and the second object O2 provide light with different spectral characteristics when illuminated by excitation light source 101b. For example, the first object O1 does not emit fluorescence Lby when illuminated by excitation light source 101b, while the second object O2 emits fluorescence Lby when illuminated by excitation light source 101b.

[0095] In some embodiments, the target area S is a target area in a surgical scenario, the first object O1 is an unfluorescently labeled tissue in the surgical scenario, such as normal tissue, and the second object O2 is a fluorescently labeled tissue in the surgical scenario, such as diseased tissue. Thus, the first object O1 does not fluoresce under the illumination of the excitation light source 101b, while the second object O2 fluoresces under the illumination of the excitation light source 101b, thereby enabling the first object O1 and the second object O2 to provide light with different spectral characteristics under the illumination of the excitation light source 101b.

[0096] In some embodiments, fluorescent markers such as indocyanine green, fluorescein, and rhodamine can be used to fluorescently label tissues in a surgical setting. For example, the first object O1 is normal tissue within the surgical area, and the second object O2 is diseased tissue, such as tumor tissue, within the surgical area. In other embodiments, the first object O1 and the second object O2 can also be other types of objects. Taking the first object O1 as normal tissue and the second object O2 as diseased tissue as an example, the diseased tissue within the target area S can be labeled using fluorescent markers (such as indocyanine green, fluorescein, and rhodamine). Normal tissue does not fluoresce under the illumination of the excitation light source 101b, while the diseased tissue labeled with the fluorescent marker fluoresces under the illumination of the excitation light source 101b.

[0097] Imaging module 102 acquires an image Is of target region S. Imaging module 102 may include lens 102a and image sensor 102b. Visible light Lax and fluorescence Lby from target region S can be captured by lens 102a and imaged by image sensor 102b to obtain image Is. Image Is includes a first region R1 corresponding to the first object O1 and a second region R2 corresponding to the second object O2. The first region R1 and the second region R2 have different image signals. In some embodiments, the image signal may include, but is not limited to, at least one of brightness, chroma, saturation, contrast, and boundary pixels of different regions. As an illustrative example, image sensor 102b may include, but is not limited to, a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) image sensor.

[0098] Imaging module 102 images the target region S based on the visible light Lax and fluorescence Lby provided by the target region S, obtaining the acquired image Is. Since the first object O1 and the second object O2 provide light with different spectral characteristics under the illumination of the excitation light source 101b, for example, the first object O1 does not emit fluorescence under the illumination of the excitation light source 101b, while the second object O2 emits fluorescence under the illumination of the excitation light source 101b, the first region R1 corresponding to the first object O1 in image Is does not include fluorescence signal (also called non-fluorescent region), while the second region R2 corresponding to the second object O2 in image Is includes fluorescence signal (also called fluorescent region), thus making the first region R1 corresponding to the first object O1 and the second region R2 corresponding to the second object O2 in image Is have different image signals. For example, the first object O1 is a tissue in a surgical scene that has not been fluorescently labeled, such as normal tissue, and the second object O2 is a tissue in a surgical scene that has been fluorescently labeled, such as diseased tissue. The first object O1 does not fluoresce under the illumination of the excitation light source 101b, while the second object O2 fluoresces under the illumination of the excitation light source 101b. This results in the first region R1 in the image Is corresponding to the first object O1 having no fluorescent signal (called the non-fluorescent region), and the second region R2 corresponding to the second object O2 having a fluorescent signal (called the fluorescent region). Thus, the first region R1 corresponding to the first object O1 and the second region R2 corresponding to the second object O2 in the image Is have different image signals.

[0099] In some embodiments, lens 102a can be an optical system 11, and image sensor 102b can be disposed on the image side of optical system 11. Lens 102a is used to receive light signals from target area S, and image sensor 102b is used to convert the light signals after passing through optical system 11 into electrical signals to obtain an image Is of target area S. In this embodiment, the light signals may include a first light (visible light Lax) and a second light (fluorescence Lby) provided by target area S under the synchronous illumination of visible light La emitted by visible light source 101a and excitation light Lb emitted by excitation light source 101b. The first light and the second light are imaged in the same image Is in image sensor 102b after passing through optical system 11. For the specific structure of lens 102a, please refer to the description of optical system 11 in the previous embodiment of this disclosure, which will not be repeated here.

[0100] In some embodiments, lens 102a may also be other optical systems capable of capturing visible light Lax and fluorescence Lby from target region S and entering image sensor 102b for imaging to obtain image Is, without limiting lens 102a in this regard.

[0101] The visible light Lax and / or fluorescence Lby from the target region S may also include excitation light Lbx reflected from the target region S under the illumination of excitation light Lb emitted by the excitation light source 101b. When imaging the target region S, the excitation light Lbx will form stray light and interfere with the imaging results. Therefore, by setting a filter 1101 in the optical system 11 (lens 102a) to filter out the excitation light Lbx included in the visible light Lax and / or fluorescence Lby from the target region S, the interference of excitation light Lbx on the imaging results is reduced, and the imaging quality is improved.

[0102] It should be noted that the filter 1101 of the optical system 11 is used to block light with wavelengths within a preset range. In order for the filter 1101 to block unwanted light, such as excitation light, while ensuring high transmittance of the required light, such as visible light and fluorescence, the wavelengths of the excitation light Lb emitted by the second light source 101b (excitation light source 101b) and the excitation light Lbx reflected by the target area S under the illumination of the excitation light Lb emitted by the excitation light source 101b are both within the preset range. However, the wavelengths of the visible light La emitted by the first light source 101a (visible light source 101a), the visible light Lax (first light) provided by the target area S under the illumination of the visible light La emitted by the visible light source 101a, and the fluorescence Lby (second light) provided by the target area S under the illumination of the excitation light Lb emitted by the excitation light source 101b are not within the preset range.

[0103] In some embodiments, the image sensor 102b is a single image sensor, meaning the number of image sensors 102b used to image the target region S can be equal to one. This single image sensor may include multiple signal channels. In some embodiments, each of these multiple signal channels can image the target region S based on both visible light (Lax) and fluorescence (Lby). In other embodiments, at least one of the multiple signal channels can image the target region S based on visible light (Lax), and at least one other signal channel can image the target region S based on fluorescence (Lby). As shown in FIG11, FIG11 is a schematic diagram of the response intensity of the image sensor of this disclosure to light in different wavelength bands.

[0104] The multiple signal channels may include at least two of a red (R) signal channel, a green (G) signal channel, and a blue (B) signal channel. The multiple signal channels may form a Bayer array, where each signal channel can sense color information in the red, green, or blue band of visible light (Lax). At least one of the red, green, and blue signal channels can sense fluorescence (Lby), or each of the red, green, and blue signal channels can sense fluorescence (Lby).

[0105] The multiple signal channels may also include at least two of a red (R) signal channel, a first green (Gr) signal channel, a second green (Gb) signal channel, and a blue (B) signal channel. The multiple signal channels can form a Bayer array, where each signal channel can sense color information from one of the red, first green, second green, or blue bands in visible light (Lax). At least one of the red, first green, second green, and blue signal channels can sense fluorescence (Lby), or each of the red, first green, second green, and blue signal channels can sense fluorescence (Lby).

[0106] When a single image sensor is used to image the target region S based on the visible light Lax and fluorescence Lby provided by the target region S, and the acquired image Is is obtained, since the first object O1 in the target region S only reflects visible light Lax and does not emit fluorescence Lby, while the second object O2 reflects both visible light Lax and emits fluorescence Lby, the single image sensor can sense both visible light Lax and fluorescence Lby. Therefore, in the image Is acquired by the single image sensor, the first region R1 corresponding to the first object O1 includes visible light signals but does not include fluorescence signals and is called the non-fluorescent region, and the second region R2 corresponding to the second object O2 includes both visible light signals and fluorescence signals and is called the fluorescent region. Thus, an image Is obtained by the single image sensor includes both fluorescent and non-fluorescent regions.

[0107] In some embodiments, if the visible light source 101a is red light with a wavelength between 600nm and 660nm, the target area S provides red light and fluorescence under the illumination of red light and excitation light. The imaging module 102 acquires an image Is of the target area S based on the red light and fluorescence provided by the target area S. Since the absorption rate of red light by the tissue in the target area is generally low in surgical scenarios, the image Is acquired by the imaging module 102 based on the red light and fluorescence provided by the target area S has high brightness.

[0108] In some embodiments, if the visible light source 101a is blue light with a wavelength between 380nm and 470nm, the target area S provides blue light and fluorescence under the illumination of blue light and excitation light. The imaging module 102 acquires an image Is of the target area S based on the blue light and fluorescence provided by the target area S. Since the tissue in the target area generally has a high absorption rate of blue light in surgical scenarios, the image Is acquired by the imaging module 102 based on the blue light and fluorescence provided by the target area S has high contrast and clarity.

[0109] In some embodiments, if the visible light source 101a is yellow light with a wavelength between 550nm and 650nm, the target area S provides yellow light and fluorescence under the illumination of yellow light and excitation light. The imaging module 102 acquires the image Is of the target area S based on the yellow light and fluorescence provided by the target area S. Since the absorption rate of yellow light by the tissue in the target area in the surgical scene is between that of blue light and red light, the image Is acquired by the imaging module 102 based on the yellow light and fluorescence provided by the target area S can ensure both image brightness and image clarity and contrast.

[0110] Image processor 103 performs enhancement processing on image Is to enhance the difference between the image signal of the first region R1 and the image signal of the second region R2 in image Is. The enhancement processing includes, but is not limited to, at least one of the following: white balance processing, linear color correction, and nonlinear color mapping.

[0111] In some embodiments, the image processor 103 directly enhances the image Is acquired by the imaging module 102 to obtain an enhanced image. That is, the image processor 103 does not perform any compositing processing on the image Is acquired by the imaging module 102 during the enhancement process. In this embodiment, the imaging module 102 uses a single image sensor to image the target region S based on visible light Lax and fluorescence Lby provided by the target region S, so that the resulting image Is includes both fluorescent and non-fluorescent regions. During the process of the image processor 103 directly enhancing the image Is acquired by the imaging module 102 to obtain the enhanced image, the enhancement processing is performed on only this single image Is. In this embodiment, the image processor 103 only performs enhancement processing on the image obtained by the image sensor 102b, without any compositing processing, to obtain an enhanced image that visually distinguishes the first region from the second region. In some embodiments, the enhanced image obtained by the image processor 103 is directly presented to the observer through a display device, allowing the observer to directly distinguish the first region from the second region from the presented enhanced image. In other embodiments, after the image processor 103 obtains the enhanced image, it can undergo image processing such as image merging and color adjustment before being presented to the observer through a display device.

[0112] In some embodiments, the image processor 103 performs white balance processing on the image Is, specifically by adjusting the ratios of each color channel in the image Is to amplify the image signal of the second region R2 in the image Is, such as amplifying the fluorescence signal of the fluorescent region in the image Is, thereby amplifying the color difference between the image signals of the first region R1 and the second region R2 in the image Is. Each color channel includes three color channels: R, G, and B.

[0113] In some embodiments, the linear color correction processing of image Is by image processor 103 specifically includes: image processor 103 correcting image Is using a linear color correction matrix to enhance the color difference between the first region R1 and the second region R2 in image Is. Specifically, a mapping relationship between the color space of the input image and the target color space can be established. Typically, for an RGB three-channel sensor, linear color correction uses a 3×3 linear color correction matrix. Each element of the linear color correction matrix represents the weight relationship between the input channel and the target color channel. The corrected color value is obtained by multiplying each pixel value of the input image with the linear color correction matrix. In this embodiment, by performing linear color correction on image Is, the color difference between fluorescent and non-fluorescent regions in the same image Is can be improved, and the color of the fluorescent region can be corrected to the target color, such as green or blue, while the color of the non-fluorescent region can be corrected to black and white, pseudo-color, or color with the highest possible color fidelity.

[0114] In some embodiments, the image processor 103 performs nonlinear color mapping processing on image Is, specifically including: establishing a color mapping table; and performing nonlinear transformation on the RGB values ​​of image Is based on the color mapping table and a preset nonlinear mapping algorithm to enhance the color difference between the first region R1 and the second region R2 in image Is, such as enhancing the color difference between fluorescent and non-fluorescent regions in image Is. Specifically, nonlinear three-dimensional color mapping processing is used to perform nonlinear color mapping processing on image Is. A color mapping table is established, and based on the RGB values ​​of image Is and the color mapping table, a target R'G'B' is output based on a preset nonlinear transformation algorithm, thereby obtaining an enhanced image. In this embodiment, by performing nonlinear three-dimensional color mapping on image Is, the color difference between fluorescent and non-fluorescent regions in the same image Is can be improved, and the color of the fluorescent region can be corrected to a target color, such as green or blue, and the color of the non-fluorescent region can be corrected to black and white, pseudo-color, or color with the highest possible color fidelity.

[0115] In some embodiments, the visible light source 101a and the excitation light source 101b can synchronously illuminate the target region S. The target region S receives mixed light under the synchronous illumination of the visible light source 101a and the excitation light source 101b. This mixed light includes visible light Lax and fluorescence Lby provided by the target region S under the synchronous illumination of the visible light source 101a and the excitation light source 101b. The lens 102a of the imaging module 102 receives the light signal from the target region S. The image sensor 102b converts the light signal transmitted through the lens 102a into an electrical signal to image the target region S, obtaining an image Is. The image processor 103 performs enhancement processing on the image Is obtained by the image sensor 102b to enhance the difference between the image signal of the first region R1 and the image signal of the second region R2.

[0116] In this embodiment, a visible light source 101a and an excitation light source 101b are simultaneously used to illuminate the target region S. The target region S can provide both visible light (Lax) and fluorescence (Lby) at the same time, ensuring that each frame image Is acquired by the image sensor 102b includes both the first region R1 and the second region R2. The first region R1 contains visible light information, and the second region R2 contains both visible light and fluorescence information. This ensures that each acquired frame image Is is free from motion blur and delay issues, improving image quality. Simultaneously, the image processor 103 enhances the image Is acquired by the image sensor 102b to improve the difference between the image signals of the first region R1 and the second region R2. Since the enhancement processing is performed directly on the image Is acquired by the image sensor 102b, without the processing and synthesis of multiple images, the complexity of the enhancement processing is simplified. Furthermore, since only one image needs to be enhanced, the complexity of the enhancement processing is further simplified, improving image processing efficiency. Since a single image sensor 102b can be used to obtain an image Is that includes both visible light and fluorescence information, it can effectively reduce hardware size and cost, and facilitate pipelined processing of multiple frames of images, thereby improving the efficiency and flexibility of the image processing process.

[0117] In some embodiments, the imaging system 10 further includes a controller (not shown) configured to control the imaging module 102 to image the target region S.

[0118] In some embodiments, the controller is further configured to control the light source 101 to adjust the intensity of the first light source 101a and / or the second light source 101b, thereby enhancing the difference between the image signal of the first region R1 and the image signal of the second region R2 of the image Is acquired by the imaging module 102. For example, under illumination by the first light source 101a and the second light source 101b of the same intensity, if the signal intensity of the first light Lax is relatively strong while the signal intensity of the second light Lby is relatively weak, the intensity of the first light source 101a can be reduced and / or the intensity of the second light source 101b can be increased.

[0119] This disclosure provides an endoscope system. Referring to Figure 12, which is a structural diagram of the endoscope system according to an embodiment of this disclosure, the endoscope system 20 may include a light source device 201, an imaging device 202, and an image processing device 203. The light source device 201 includes the light source 101 of the imaging system 10, the imaging device 202 includes the imaging module 102 of the imaging system 10, and the image processing device 203 includes the image processor 103 of the imaging system 10.

[0120] In some embodiments, the endoscope system 20 may further include a display unit (not shown) configured to receive and display an image processed by the image processing device 203.

[0121] In some embodiments, the endoscope system 20 may further include a controller (not shown) configured to control the imaging device 202 to image the target region S.

[0122] In some embodiments, the controller is further configured to control the light source device 201 to adjust the intensity of the first light source 101a and / or the second light source 101b, thereby enhancing the difference between the image signal of the first region R1 and the image signal of the second region R2 of the image Is acquired by the imaging module 102. For example, under illumination by the first light source 101a and the second light source 101b of the same intensity, if the signal intensity of the first light Lax is relatively strong while the signal intensity of the second light Lby is relatively weak, the intensity of the first light source 101a can be reduced and / or the intensity of the second light source 101b can be increased.

[0123] This disclosure provides a surgical robot system. Please refer to Figure 13, which is a structural diagram of the surgical robot system according to an embodiment of this disclosure. Both the imaging system 10 and the endoscope system 20 described above can be applied to the surgical robot system 00. The surgical robot system 00 may include the imaging system 10 and the display system 30. The display system 30 can receive and display the image Is processed by the image processor 103 sent by the imaging system 10. In some embodiments, the imaging module 102 of the imaging system 10 may be an endoscope or a microscope. The surgical robot system 00 may include a robotic arm system 40, which includes one or more robotic arms 400. The imaging module 102 can be held on any one of the robotic arms 400. By adjusting the position and posture of the end effector of the robotic arm 400, the posture of the imaging module 102 can be changed, thereby controlling the imaging module 102 to image the target area S in a specific posture. The surgical robot system 00 may also include a console 50, on which the surgeon can operate to adjust the position and posture of the end effector of the robotic arm 400. In some embodiments, the surgical robot system 00 may also include a controller (not shown) configured to control the imaging system 10 to image the target region S. This controller may be the console 50 of the surgical robot system 00, or it may be a control unit integrated into the imaging module 102. For example, when the imaging module 102 is an endoscope, the controller may be the main unit of the endoscope.

[0124] It should be noted that the technical solutions or features described in the above embodiments can be combined or complemented with each other without conflict. The scope of protection of this disclosure is not limited to the precise structures described in the above embodiments and shown in the accompanying drawings; all modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. An optical system comprising a filter assembly and a first lens group, the first lens group comprising a plurality of lenses having optical power, the plurality of lenses being arranged sequentially from the object side to the image side along an optical axis; the first lens group being disposed on the side of the filter assembly closer to the object side, for changing the optical path of light provided by the object side to reduce the incident angle of light incident obliquely on the filter assembly; the filter assembly being disposed on the side of the first lens group closer to the image side, for blocking light with wavelengths within a preset range.

2. The optical system according to claim 1, wherein, The first lens group has a positive optical power and is used to reduce the incident angle of light rays incident on the filter component at an angle, so that the incident angle of all light rays incident on the filter component is less than a preset angle.

3. The optical system according to claim 2, wherein, It also includes a second lens group disposed near the object side and a third lens group disposed near the image side, wherein the filter assembly and the first lens group are disposed between the second lens group and the third lens group; Wherein, the optical power of the second lens group is negative, the optical power of the third lens group is negative, and the optical power of the optical path formed by the first lens group, the filter component and the third lens group is positive.

4. The optical system according to claim 3, wherein, The first lens group includes at least one lens and / or a cemented lens group, which are arranged sequentially from the object side to the image side along the optical axis. The filter assembly is disposed between the lens or cemented lens group closest to the image side and the third lens group.

5. The optical system according to claim 4, wherein, The first lens group includes a first lens, a second lens, a third lens, and a fourth lens arranged sequentially from the object side to the image side along the optical axis, and the filter assembly is disposed on the side of the fourth lens closer to the image side.

6. The optical system according to claim 5, wherein, The first lens, the second lens, and the third lens are all lenses with positive optical power, and the fourth lens is a lens with negative optical power.

7. The optical system according to claim 6, wherein, The image-side surface of the third lens is adapted to the shape of the object-side surface of the fourth lens, and the third lens and the fourth lens are cemented together.

8. The optical system according to claim 7, wherein, The image-side surface of the third lens is convex, and the object-side surface of the fourth lens is concave.

9. The optical system according to any one of claims 3-8, wherein, It also includes an aperture stop, which is disposed between the first lens group and the second lens group; the second lens group includes a fifth lens and a first element; the fifth lens is disposed close to the object side and is used to converge the light rays incident on the fifth lens to reduce the incident angle of the light rays incident on the first element; the first element is disposed close to the aperture stop and is used to guide the light rays exiting the fifth lens through the aperture stop.

10. The optical system according to claim 9, wherein, The fifth lens has its main axis parallel to the optical axis, and the object side and image side of the first element are both perpendicular to the optical axis.

11. The optical system according to claim 9, wherein, The main axis of the fifth lens is inclined to the optical axis, the object side of the first element is inclined to the optical axis, and the image side of the first element is perpendicular to the optical axis.

12. The optical system according to claim 11, wherein, The first element includes: The first prism has its incident surface parallel to and opposite to the image side surface of the fifth lens. The second prism has an incident surface that is parallel to and opposite to the exit surface of the first prism, and the exit surface is perpendicular to the optical axis. The second prism is used to ensure that light rays that are perpendicularly incident on the fifth lens enter the second prism and exit the second prism perpendicularly.

13. The optical system according to claim 12, wherein, The second prism has a first surface, a second surface, and a third surface arranged adjacent to each other; the first surface is the incident surface of the second prism, used to receive light emitted from the first prism and transmit it to the second surface, and to receive light reflected from the second surface and reflect it totally to the third surface; the second surface is used to receive light transmitted from the first surface and reflect it totally to the first surface; the third surface is the exit surface of the second prism, used to receive light reflected from the first surface and transmit it to the first lens group.

14. The optical system according to any one of claims 1-13, wherein, The filter assembly includes: The second element is a transparent optical element and its optical power is zero. A filter is disposed on the surface of the second element, and the filter is used to reflect light with wavelengths within the preset range and to block light with wavelengths within the preset range.

15. An optical system for use in an endoscope, the optical system comprising: The first sub-optical system is used to form the first optical channel; as well as A second sub-optical system is used to form a second optical channel, which is arranged side by side with the first optical channel; The first sub-optical system and the second sub-optical system share a single steering prism.

16. The optical system according to claim 15, wherein, The portion of the steering prism belonging to the first sub-optical system and the portion of the steering prism belonging to the second sub-optical system have the same thickness.

17. The optical system according to claim 15 or 16, wherein, The first sub-optical system includes a first lens group and a second lens group. The first lens group is disposed close to the object side and is used to change the optical path of the light provided by the object side. The second lens group is disposed on the side of the steering prism opposite to the first lens group and is disposed close to the object side. The second sub-optical system includes a third lens group and a fourth lens group, which are located on both sides of the steering prism; The steering prism has a first mirror surface and a second mirror surface. The first mirror surface is opposite to the second mirror surface in the thickness direction of the steering prism. The first mirror surface and the second mirror surface have an angle α, where 0 < α ≤ 90°. The second lens group and the fourth lens group are located on the side where the first mirror surface is located, and the first lens group and the third lens group are located on the side where the second mirror surface is located.

18. The optical system according to claim 17, wherein, The optical system further includes a filter assembly, which is disposed on the side of the first lens group and / or the third lens group near the image side, and is used to block light with wavelengths within a preset range.

19. The optical system according to claim 18, wherein, It also includes an aperture stop, which is disposed between the first lens group and the second lens group and / or between the third lens group and the fourth lens group. The steering prism is disposed close to the aperture stop and is used to guide the light rays emitted from the first lens group and / or the third lens group through the aperture stop.

20. The optical system according to any one of claims 17-19, wherein, The steering prism includes: The first prism has its incident surface parallel to and opposite to the image-side surface of the first lens group and / or the third lens group. The second prism has an incident surface that is parallel to and opposite to the exit surface of the first prism, and an exit surface that is perpendicular to the optical axis. The second prism is used to allow light rays that are perpendicularly incident on the first lens group and / or the third lens group to enter the second prism and then exit the second prism perpendicularly.

21. The optical system according to claim 20, wherein, The second prism has a first surface, a second surface, and a third surface arranged adjacent to each other; the first surface is the incident surface of the second prism, used to receive light emitted from the first prism and transmit it to the second surface, and to receive light reflected from the second surface and reflect it totally to the third surface; the second surface is used to receive light transmitted from the first surface and reflect it totally to the first surface; the third surface is the exit surface of the second prism, used to receive light reflected from the first surface and transmit it to the first lens group and / or the third lens group.

22. The optical system according to any one of claims 18-21, wherein, The filter assembly includes: The second element is a transparent optical element and its optical power is zero. A filter is disposed on the surface of the second element, and the filter is used to reflect light with wavelengths within the preset range and to block light with wavelengths within the preset range.

23. The optical system according to any one of claims 17-22, wherein, The second lens group is located at the near end of the steering prism along the optical path direction, and the second lens group includes at least one negative power lens; the first lens group is located at the far end of the steering prism along the optical path direction, and the first lens group includes at least one positive power lens; and / or, The second lens group includes a plano-concave negative power lens; and / or, Along the optical path from near end to far end, the first lens group includes a first positive power lens group, a second positive power lens group, a third positive power lens group, and a fourth negative power lens group.

24. An endoscope comprising a barrel and an optical system according to any one of claims 15-23, the optical system being disposed within the barrel.

25. An imaging system, comprising: An optical system, wherein the optical system is the optical system as described in any one of claims 1-14 or 15-23, the optical system being used to receive optical signals from a target area; An image sensor, disposed on the image side of the optical system, is used to convert the light signal transmitted through the optical system into an electrical signal to obtain an image of the target area.

26. The imaging system according to claim 25, wherein, It also includes a light source that illuminates the target area. The light source includes a first light source and a second light source. The target area receives a first light under the illumination of the first light source and a second light under the illumination of the second light source. The optical signal includes the first light and the second light provided by the target area under synchronous illumination by the first light source and the second light source, and the first light and the second light are imaged in the same image in the image sensor after passing through the optical system.

27. The imaging system according to claim 26, wherein, The wavelengths of the light emitted by the first light source, the first light, and the second light are all outside the preset range, while the wavelength of the light emitted by the second light source is within the preset range; And / or, The first light is visible light, and the second light is fluorescence; the first light source can emit visible light to illuminate the target area; the second light source can emit excitation light to excite the target area to emit the fluorescence; and / or, The image sensor includes multiple signal channels, each of which can sense multiple different wavelengths in the first light, and at least one of the multiple signal channels can sense the second light.

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