Endoscope lens assembly and endoscope

Abstract

Endoscope lens assembly and endoscope, the endoscope lens assembly comprising: a first lens group and a second lens group. The first lens group includes a first lens and a second lens; the second lens group is arranged axially with respect to the first lens group and includes a third lens; light for imaging enters the second lens group after passing through the first lens group; the first lens, the second lens, and the third lens are arranged in sequence along the axis, and the light for imaging passes through the first lens, the second lens, and the third lens in sequence; the distance between the light-emitting surface of the first lens and the light-incident surface of the second lens is a first distance, and the distance between the light-emitting surface of the second lens and the light-incident surface of the second lens group that is axially close to the first lens group is a second distance, and the first distance is greater than twice the second distance.

Description

Technical Field

[0001] The present invention belongs to the field of medical surgery and relates to an endoscope lens assembly and an endoscope. Background Art

[0002] Medical endoscopes are medical devices used to provide doctors with images of the internal structures of the human or animal body during clinical examinations, diagnoses, and treatments. In clinical practice, doctors can introduce the endoscope into the body through a surgical incision or a natural body orifice, such as into a target tissue (lesion site, such as an organ) or a target chamber, obtain an image of the target tissue, and observe the lesions of the target organ in the body through a window or a display. A disease diagnosis can be made directly, or a biopsy of the lesion can be taken for pathological diagnosis. At the same time, the disease can be treated in a timely manner or a therapeutic artificial product can be implanted.

[0003] With the wide application of endoscope technology in various surgeries, it is required not only to clearly see the surface layer of human tissues but also to see the tissues below the surface layer to provide more accurate images for the surgical process. In recent years, the fluorescence laparoscopy technology that combines intraoperative fluorescence imaging technology and laparoscopic minimally invasive technology has been gradually applied clinically. Fluorescence endoscopes have gradually developed and been widely used. For example, during the use of a fluorescence endoscope, an exogenous fluorescent dye (fluorescent imaging agent) can be injected into the target tissue (lesion site). The exogenous dye is selectively labeled on the target tissue, and the target tissue injected with the exogenous fluorescent dye is irradiated with near-infrared light to excite fluorescence. The fluorescence imaging system receives the fluorescence from the target tissue to obtain an image of the target tissue. Thus, structures or lesions that are not easily observable are visualized, helping doctors to see information that is invisible to the naked eye. Using a fluorescence endoscope, in addition to being able to provide an image of the surface layer of human tissues, it can also simultaneously achieve fluorescence imaging of tissues below the surface layer (such as cystic duct, lymphatic vessel, and blood vessel imaging, etc.), which plays a key role in accurate intraoperative positioning and reducing surgical risks, and realizes navigation during the surgical process. Summary of the Invention

[0004] At least one embodiment of the present invention provides an endoscope lens assembly, which includes: a first lens group and a second lens group. The first lens group includes a first lens and a second lens; the second lens group is arranged axially with the first lens group and includes a third lens; the light for imaging enters the second lens group after passing through the first lens group; the first lens, the second lens and the third lens are arranged in sequence along the axial direction, and the light for imaging passes through the first lens, the second lens and the third lens in sequence; the distance between the light-emitting surface of the first lens and the light-incident surface of the second lens is a first distance, and the distance between the light-emitting surface of the second lens and the light-incident surface of the second lens group close to the first lens group in the axial direction is a second distance, and the first distance is greater than twice the second distance. In this endoscope lens assembly, by increasing the distance between the light-emitting surface of the first lens and the light-incident surface of the second lens, it is possible to effectively reduce the stray light with too large an incident angle from the off-axis field of view from entering the field of view. These stray lights often include strong lights with high brightness, preventing these strong lights from participating in imaging through the lens assembly and causing bright spots with too high brightness in the user's field of view, interfering with imaging.

[0005] For example, in the endoscope lens assembly provided by at least one embodiment of the present invention, the first distance is 4.5 mm to 5 mm, and the curvature of the light-emitting surface of the first lens is R2, -0.72 ≤ R2 ≤ -0.55.

[0006] For example, in the endoscope lens assembly provided by at least one embodiment of the present invention, the first lens group further includes a dimming prism, and the dimming prism is located between the first lens and the second lens and is configured to change the propagation direction of the light from the first lens.

[0007] For example, in the endoscope lens assembly provided by at least one embodiment of the present invention, the light-incident surface of the dimming prism is perpendicular to the axial direction, the first lens is located on one side of the dimming prism in the longitudinal direction and faces the light-incident surface of the dimming prism, the longitudinal direction is perpendicular to the axial direction, the light-incident surface of the first lens is generally perpendicular to the axial direction, and the dimming prism is configured to change the propagation direction of the light emitted from the first lens by a target angle.

[0008] For example, in the endoscope lens assembly provided by at least one embodiment of the present invention, the target angle is 90°.

[0009] For example, in the endoscope lens assembly provided by at least one embodiment of the present invention, the second lens group further includes a beam splitting prism, the beam splitting prism is located at an end of the second lens group away from the first lens group in the axial direction, and includes an incident light surface, a first outgoing light surface, and a second outgoing light surface; the beam splitting prism is configured to disperse the light incident on the incident light surface of the beam splitting prism after passing through the lenses of the first lens group and the second lens group into visible light and infrared light, the visible light exits from the first outgoing light surface, and the infrared light exits from the second outgoing light surface.

[0010] For example, in the endoscope lens assembly provided by at least one embodiment of the present invention, the first outgoing light surface is perpendicular to the axial direction, and the second outgoing light surface is perpendicular to the first outgoing light surface.

[0011] For example, in the endoscope lens assembly provided by at least one embodiment of the present invention, it further includes a visible light photosensitive element and an infrared photosensitive element. The visible light photosensitive element is located on the outgoing light side of the first outgoing light surface and is configured to receive the visible light for imaging, and the infrared photosensitive element is located on the outgoing light side of the second outgoing light surface and is configured to receive the infrared light for imaging.

[0012] For example, the endoscope lens assembly provided by at least one embodiment of the present invention further includes: a first linear polarizer, a second linear polarizer, and a third linear polarizer; the first linear polarizer is located on the incident light side of the first lens, the second linear polarizer is a λ / 2 wave plate and is configured to cause a phase delay of π for the light passing through the first linear polarizer; the included angle between the main axis of the first linear polarizer and the main axis of the second linear polarizer is 15°; the main axis direction of the third linear polarizer is the same as the main axis direction of the first linear polarizer.

[0013] For example, in the endoscope lens assembly provided by at least one embodiment of the present invention, the first lens group has a negative optical power, and the second lens group has a positive optical power; the second lens group further includes a fourth lens and a fifth lens; the first lens has a negative optical power, the incident light surface of the first lens is a plane or a convex surface, and the outgoing light surface of the first lens is a concave surface; the second lens has a positive optical power, the incident light surface of the second lens is a convex surface, and the outgoing light surface of the second lens is a concave surface; the third lens has a positive optical power, the incident light surface of the third lens is a concave surface, and the outgoing light surface of the third lens is a convex surface; the fourth lens has a positive optical power, the incident light surface of the fourth lens is a convex surface, and the outgoing light surface of the fourth lens is a convex surface; the fifth lens has a negative optical power, the incident light surface of the fifth lens is a convex surface, and the outgoing light surface of the fourth lens is a convex surface.

[0014] For example, in the endoscope lens assembly provided by at least one embodiment of the present invention, the fourth lens is glued to the fifth lens, the refractive index of the fourth lens is less than that of the fifth lens, and the dispersion degree of the fifth lens is less than the refractive index of the fourth lens.

[0015] For example, the endoscope lens assembly provided by at least one embodiment of the present invention further includes a diaphragm, and the diaphragm is located between the second lens and the third lens, or the diaphragm is located between the first lens and the second lens.

[0016] At least one embodiment of the present invention further provides an endoscope lens assembly, which includes: a first lens group and a second lens group. The first lens group includes a first lens and a second lens; the second lens group is arranged axially with the first lens group and includes at least one lens, and the light for imaging enters the second lens group after passing through the first lens group; the first lens group further includes a dimming prism, and the dimming prism is located between the first lens and the second lens and is configured to change the propagation direction of the light from the first lens. In this endoscope lens assembly, the propagation direction of the light from the first lens can be changed through the dimming prism, so that the incident light surface of the light entering the first lens group is not perpendicular to the axis, for example, it can be substantially parallel to the axis, so that the light does not enter the first lens group as a whole along the axis from one end of the first lens group in the axial direction, but enters the first lens group from the side, which can shorten the size of the lens assembly in the axial direction.

[0017] For example, in the endoscope lens assembly provided by at least one embodiment of the present invention, the incident light surface of the first lens is perpendicular to the axis as a whole, and the dimming prism is configured to change the propagation direction of the light emitted from the first lens by 90°.

[0018] At least one embodiment of the present invention further provides an endoscope, which includes any one of the endoscope lens assemblies provided by the embodiments of the present invention.

[0019] For example, the endoscope provided by at least one embodiment of the present invention includes a main body, a plurality of sub-lenses that can be opened and closed, and a driving device. The plurality of sub-lenses are located at the front end of the main body, and each sub-lens includes the endoscope lens assembly and is configured to acquire image information; each sub-lens includes a housing, and the endoscope lens assembly is arranged in the housing; the driving device is at least partially located in the main body, is connected to the plurality of sub-lenses, and is configured to drive the plurality of sub-lenses to move relative to the main body so that the plurality of sub-lenses approach and move away from each other; the plurality of sub-lenses extend axially in the closed state, and the main body of the endoscope also extends along the axis.

[0020] For example, in the endoscope provided by at least one embodiment of the present invention, in the first lens group, a dimming prism is further included. The dimming prism is located between the first lens and the second lens. The incident surface of the dimming prism is perpendicular to the axial direction. The first lens is located on one side of the dimming prism in the longitudinal direction and faces the incident surface of the dimming prism. The longitudinal direction is perpendicular to the axial direction. The incident surface of the first lens is generally perpendicular to the axial direction. When the dimming prism is configured to change the propagation direction of the light emitted from the first lens by a target angle, for each of the sub-lenses, the incident surface of the first lens is substantially parallel to the incident surface of the sub-lens that is opposed to the incident surfaces of other sub-lenses in the closed state. Brief Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings described below only relate to some embodiments of the present invention and do not limit the present invention.

[0022] Figure 1 is a schematic structural diagram of an endoscope lens assembly provided by an embodiment of the present invention;

[0023] Figure 2 is Figure 1 a schematic diagram after adding an optical path on the basis of

[0024] Figure 3A is a schematic diagram of removing stray light by using the endoscope lens assembly provided by an embodiment of the present invention;

[0025] Figure 3B is a schematic diagram of an endoscope lens assembly that cannot remove stray light;

[0026] Figure 4 is a schematic structural diagram of another endoscope lens assembly provided by an embodiment of the present invention;

[0027] Figure 5 is a schematic structural diagram of yet another endoscope lens assembly provided by an embodiment of the present invention;

[0028] Figure 6 is a schematic structural diagram of still another endoscope lens assembly provided by an embodiment of the present invention;

[0029] Figure 7 is a schematic diagram of an endoscope provided by an embodiment of the present invention;

[0030] Figure 8A and Figure 8C is a schematic diagram of a foldable endoscope including a plurality of sub-lenses in the closed state provided by an embodiment of the present invention;

[0031] Figure 8B and Figure 8D is a schematic diagram of an openable endoscope including multiple sub-lenses in an open state provided by an embodiment of the present invention. Detailed implementation manners

[0032] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0033] Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings understood by those of ordinary skill in the art to which the present invention pertains. The "first", "second" and similar terms used in the specification and claims of this patent application of the present invention do not denote any order, quantity or importance, but are only used to distinguish different components. The terms such as "including" or "comprising" mean that the elements or objects appearing before this term cover the elements or objects listed after this term and their equivalents, without excluding other elements or objects. The terms such as "inside", "outside", "above", "below", etc. are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0034] The drawings in the present invention are not strictly drawn according to the actual proportions, and the specific dimensions of each structure can be determined according to actual needs. The number of multiple lens assemblies in the endoscope is not limited to the number shown in the figures. The drawings described in the present invention are only schematic diagrams of the structures.

[0035] The currently widely used fluorescence imaging agent in clinical practice is indocyanine green (ICG). ICG enters the human body through local tissue or intravenous injection and binds to plasma lipoproteins. After being irradiated by near-infrared light with a wavelength of about 805 nm, it emits fluorescence with a wavelength of about 835 nm. The fluorescence imaging system captures the fluorescence signal in real time and forms an image, which is accurately superimposed synchronously with the white light image of the same field of view to achieve the purpose of fluorescence localization and navigation.

[0036] When the endoscope is used for imaging in a cavity, the ambient light for imaging from the target tissue enters the endoscope and forms an image. This ambient light often includes stray light with too large an incident angle, especially strong stray light with a large brightness. If this kind of stray light enters the field of view and participates in imaging, it will cause bright spots with too large a brightness to appear in the field of view of the user (doctor), interfering with imaging and seriously affecting the user's observation of the target tissue such as the diseased tissue and subsequent surgical operations in actual applications.

[0037] In addition, if a lens that can sense both visible light and infrared light is to be provided on the endoscope, due to the large number of lenses and the too large size of the lens chip for sensing infrared light, it cannot be placed inside the endoscope tube, or the volume of the lens is too large, making it difficult to simultaneously provide a lens for sensing visible light and infrared light on one endoscope. In particular, the size of the chip (such as a CCD or COMS chip) of a fluorescence endoscope with high resolution (for example, both visible light imaging and infrared light imaging reach 4K resolution) is too large. Therefore, while achieving visible light imaging and infrared light imaging, the radial size and axial size of the endoscope lens are minimized as much as possible. Here, the axial direction refers to the extending direction of the barrel of the optical path system provided on the endoscope, and the radial direction is the direction perpendicular to the axial direction. The too large radial size of the barrel of the optical path system provided on the endoscope affects the size of the hole opened on the cavity surface (such as the abdominal cavity, thoracic cavity, etc.) of the target object (such as the surgical object) for the endoscope to pass through, and the too large axial size affects the space occupied and flexibility after the barrel enters the chamber of the target object.

[0038] The endoscope provided by the embodiment of the present invention can be applied to clinical examinations, diagnoses, and treatments to provide doctors with images of the internal structures of the human body or animal body.

[0039] At least one embodiment of the present invention provides an endoscope lens assembly, which includes: a first lens group and a second lens group. The first lens group includes a first lens and a second lens; the second lens group is arranged axially with respect to the first lens group and includes a third lens; the light for imaging enters the second lens group after passing through the first lens group; the first lens, the second lens, and the third lens are arranged in sequence along the axial direction, and the light for imaging passes through the first lens, the second lens, and the third lens in sequence; the distance between the light-emitting surface of the first lens and the light-incident surface of the second lens is a first distance, and the distance between the light-emitting surface of the second lens and the light-incident surface of the second lens group close to the first lens group in the axial direction is a second distance, and the first distance is greater than twice the second distance. In this endoscope lens assembly, by increasing the distance between the light-emitting surface of the first lens and the light-incident surface of the second lens, it is possible to effectively reduce the stray light with too large incident angles from the off-axis field of view from entering the field of view. These stray lights often include strong lights with high brightness, preventing these strong lights from participating in imaging through the lens assembly and causing too bright spots to appear in the user's field of view, interfering with imaging.

[0040] At least one embodiment of the present invention further provides an endoscope lens assembly, which includes: a first lens group and a second lens group. The first lens group includes a first lens and a second lens; the second lens group is arranged axially with the first lens group and includes at least one lens, and the light for imaging enters the second lens group after passing through the first lens group; the first lens group further includes a dimming prism, the dimming prism is located between the first lens and the second lens, and is configured to change the propagation direction of the light from the first lens. In this endoscope lens assembly, the propagation direction of the light from the first lens can be changed through the dimming prism, so that the incident surface of the light entering the first lens group is not perpendicular to the axis, for example, can be substantially parallel to the axis, so that the light does not enter the first lens group as a whole along the axis from one end of the first lens group in the axial direction, but enters the first lens group from the side, which can shorten the size of the lens assembly in the axial direction.

[0041] For example, the axis is the direction of the optical axis of the first lens group or the direction of the optical axis of the second lens group, for example, the direction of the optical axis of the first lens group is the same as the direction of the optical axis of the second lens group.

[0042] Exemplarily, Figure 1 is a schematic structural diagram of an endoscope lens assembly provided by an embodiment of the present invention, Figure 2 is in Figure 1 schematic diagram after adding an optical path on the basis. Referring to Figure 1-2 , an endoscope lens assembly 10 provided by an embodiment of the present invention includes: a first lens group FL and a second lens group RL. The first lens group FL includes a first lens L1 and a second lens L2; the second lens group RL is arranged axially on the first lens group FL in the axial direction D1 and includes a third lens L3, and the light for imaging enters the second lens group RL after passing through the first lens group FL; the first lens L1, the second lens L2, and the third lens L3 are arranged in sequence along the axial direction D1, and the light for imaging passes through the first lens L1, the second lens L2, and the third lens L3 in sequence; the distance between the light-emitting surface of the first lens L1 and the light-incident surface of the second lens L2 is a first distance l1 , the distance between the light-emitting surface of the second lens L2 and the light-incident surface of the second lens group RL close to the first lens group FL in the axial direction D1 is a second distance l2 , the first distance l1 is greater than the second distance l2Twice that amount. Thus, in the endoscopic lens assembly 10, by increasing the distance between the light-emitting surface of the first lens L1 and the light-incident surface of the second lens L2, it is possible to effectively reduce the large-angle stray light with too large an incident angle in the ambient light from the target tissue from entering the field of view. The incident angle of these stray lights on the light-incident surface of the first lens L1 is relatively large, for example, greater than 80° (of course, it is not limited to this numerical range), and often includes strong lights with relatively high brightness. These strong lights include, for example, specular reflections of tissue fluid from the target tissue or strong lights caused by other reasons, etc. Preventing these strong lights from participating in imaging through the lens assembly can prevent the appearance of highlights with too high brightness in the user's field of view, interfering with imaging.

[0043] Figure 3A is a schematic diagram of removing stray light by using the endoscopic lens assembly provided by an embodiment of the present invention; Figure 3B is a schematic diagram of an endoscopic lens assembly that cannot remove stray light. Refer to Figure 3A , the large-angle stray light from the ambient light is incident on the light-incident surface r3 of the second lens L2 close to L1 after passing through the first lens L1. Due to the above-mentioned first distance l1 is large enough. Thus, on the one hand, part of the stray light passes through the second lens L2, and the stray light passing through the second lens L2 deviates far from the axial direction D1 and basically does not enter the subsequent imaging optical path. On the other hand, part of the stray light is reflected by the light-incident surface r3 of the second lens L2. After being reflected by the light-incident surface r3 of the second lens L2, the stray light deviates from the axial direction and exits outside the optical path of the endoscopic lens assembly and will not be reflected by the first lens L1 and enter the optical path of the endoscopic lens assembly again. Thus, preventing these strong lights from participating in imaging through the lens assembly can prevent the appearance of highlights with too high brightness in the user's field of view, interfering with imaging. In practice, it can greatly improve the quality of the imaging field of view, which is of great significance for improving the processing efficiency of the doctor for the target tissue image and the accuracy of judgment. Conversely, refer to Figure 3B , if the above-mentioned first distance l1 is too small, it will cause the large-angle stray light from the ambient light, after passing through the first lens L1, the stray light incident on the second lens L2 is relatively close to the optical axis of the first lens group and the second lens group. Part of the stray light will pass through the second lens L2 and enter the subsequent imaging optical path, for example, continue to enter the second lens group RL. Part of the stray light is reflected by the light-incident surface r3 of the second lens L2 to the first lens L1 and then reflected back to the subsequent optical path by the light-emitting surface r2 of the first lens L1, thus unable to eliminate the interference of this part of the stray light on imaging.

[0044] It should be noted that the first distance l1 refers to the distance between the position on the axial direction D1 of the light-emitting surface of the first lens L1 that is farthest from the second lens L2 and the position on the axial direction D1 of the light-incident surface of the second lens L2 that is closest to the first lens L1.

[0045] For example, the first distance l1 is 4.5 mm to 5 mm, and the curvature of the light-emitting surface of the first lens L1 is R2, where -0.72 ≤ R2 ≤ -0.55. For the dimensions of the barrel for accommodating the endoscope lens assembly 10 of a commonly used endoscope, through experimental exploration, when the first distance l1 and and the curvature R2 of the light-emitting surface of the first lens L1 are within the above ranges, a better effect of removing stray light can be obtained. At the same time, the turning angle of the incident light for imaging can be appropriately constrained, and a better imaging effect can be obtained. If the curvature R2 of the light-emitting surface of the first lens L1 is too low, the distance between the first lens L1 and the second lens L2 will be reduced, leaving no space to install the prism P1 and possibly resulting in too much stray light. If the curvature R2 of the light-emitting surface of the first lens L1 is too large, the distance between the first lens L1 and the second lens L2 will be increased too much, increasing the total length of the endoscope lens assembly 10 in the axial direction D1. In actual applications, the lens is required to be as compact as possible, and the total length of the endoscope lens assembly 10 in the axial direction D1 should be minimized. For the specific reasons, please refer to the detailed introduction in the following text. Therefore, exploring the appropriate curvature of the light-emitting surface of the first lens L1 is very important for taking into account the effect of removing stray light and reducing the total length of the endoscope lens assembly 10 in the axial direction D1 in practical applications.

[0046] For example, as Figure 1 shown, the first lens group FL further includes a dimming prism P1. The dimming prism P1 is located between the first lens L1 and the second lens L2 and is configured to change the angle of the light from the first lens L1. For example, in Figure 1 the embodiment shown, the shape of the dimming prism P1 is a cuboid, and its cross-sectional shape is a rectangle, which can play a role in guiding light. At the same time, setting the dimming prism P1 can increase the distance between the first lens L1 and the second lens L2, meeting the requirements for the distance between the first lens L1 and the second lens L2.

[0047] For example, referring to Figure 1, the second lens group RL further includes a beam splitting prism P2. The beam splitting prism P2 is located at the end of the second lens group RL away from the first lens group FL on the axial direction D1, and includes an incident light surface S0, a first outgoing light surface S1, and a second outgoing light surface S2. During the operation of the endoscope, the light from the light source irradiates the target tissue. For example, the light from the light source includes infrared light and visible light. The visible light after optical processes such as reflection and refraction by the target tissue, as well as the infrared light generated by the target tissue being excited under infrared light irradiation or the infrared light generated by the exogenous fluorescent imaging agent injected into the target tissue being excited under infrared light irradiation, are incident on the first lens group RF together. For example, they enter the first lens group RF through the incident surface of the first lens L1, and finally are emitted by the beam splitting prism P2 and received by the photosensitive element for imaging. The beam splitting prism P2 is configured to disperse the light incident on the incident light surface S0 of the beam splitting prism P2 after passing through the lenses of the first lens group FL and the second lens group RL into visible light and infrared light. The visible light is emitted from the first outgoing light surface S1, and the infrared light is emitted from the second outgoing light surface S2. For example, the beam splitting prism P2 includes a beam splitting surface. The light incident on the beam splitting prism P2 is dispersed by the beam splitting surface into infrared light and visible light that are respectively emitted from the first outgoing light surface S1 and the second outgoing light surface S2. For example, the angles between the beam splitting surface and the first outgoing light surface S1 and the second outgoing light surface S2 are both 45°, which is convenient for design and reduces the manufacturing difficulty. A beam splitting film is coated on the beam splitting surface. The beam splitting film transmits visible light and reflects infrared light. Thus, the light emitted from the first outgoing light surface S1 is infrared light, and the light emitted from the second outgoing light surface S2 is visible light. For example, the wavelength band of the visible light transmitted by the beam splitting film is 425nm - 675nm, and the wavelength band of the infrared light reflected by the beam splitting film is 830nm - 880nm. In this way, a visible light photosensitive element and an infrared photosensitive element can be respectively arranged on the outgoing light sides of the first outgoing light surface S1 and the second outgoing light surface S2. For example, the endoscope lens assembly 10 further includes a visible light photosensitive element and an infrared photosensitive element. The visible light photosensitive element is located on the outgoing light side of the first outgoing light surface S1 and is configured to obtain a visible light image by imaging the visible light received from the first outgoing light surface S1; the infrared photosensitive element is located on the outgoing light side of the second outgoing light surface S2 and is configured to obtain an infrared light image by imaging the infrared light received from the second outgoing light surface S2. Thus, a visible light image and an infrared light image can be obtained simultaneously. For example, the two images within the same field of view can be synchronously and accurately superimposed. In addition to providing an image of the human tissue surface layer, it can also simultaneously realize the fluorescence imaging of the tissue below the surface layer (such as the imaging of the cystic duct, lymphatic vessels, and blood vessels, etc.), which plays a key role in accurate intraoperative positioning and reducing the surgical risk. During the diagnostic process and the surgical process, this endoscope can provide doctors with more accurate information about the target tissue and better navigation.

[0048] For example, the fluorescence imaging agent is indocyanine green (ICG). Its imaging principle is that ICG enters the human body through local tissue or intravenous injection and binds to plasma lipoproteins. After being irradiated with near-infrared light with a wavelength of about 805 nm, it emits fluorescence with a wavelength of about 835 nm. Of course, the fluorescence imaging agent is not limited to the above-listed types, and the wavelength of the emitted fluorescence is not limited to about 835 nm. This is only exemplary here, and the specific wavelength of the near-infrared light is not limited in the embodiments of the present invention.

[0049] For example, the first light-emitting surface S1 is perpendicular to the axis D1, and the second light-emitting surface S2 is perpendicular to the first light-emitting surface S1, which is convenient for design and layout of visible light photosensitive elements and infrared photosensitive elements, making the entire lens structure for the endoscope including the endoscope lens assembly 10 and the two photosensitive elements compact, and reducing the volume of the endoscope lens.

[0050] For example, as Figure 1 shown, the first lens group FL has a negative focal power, and the second lens group RL has a positive focal power, that is, Ff / F < 0, where Ff represents the focal length of the first lens group FL, and F represents the focal length of the system including the first lens group FL and the second lens group RL, so as to achieve a larger relative aperture and have a longer back focal length, which is convenient for placing the beam splitter prism P2.

[0051] The first lens L1 has a negative focal power. The first lens L1 has an incident surface r1 away from the second lens L2 and an exit surface r2 close to the second lens L2. The incident surface r1 of the first lens L1 is a plane or a convex surface, and the exit surface r2 of the first lens L1 is a concave surface; the incident surface r1 of the first lens L1 being a plane is beneficial to preventing interference with the front window (i.e., the incident glass of the housing for accommodating the endoscope lens assembly 10), improving the structural compactness of the endoscope lens assembly 10, reducing the total length of the endoscope lens assembly 10 along the axis D1, and reducing the design difficulty and assembly complexity. Thus, the first lens L1 is a plano-concave lens, and the exit surface r2 of the first lens L1 is a concave surface so that the angle between the incident light and the axis D1 becomes smaller, facilitating the light for imaging to enter the subsequent optical path. The curvature of the incident surface r1 of the first lens L1 being negative can achieve a larger field of view and a divergent light beam, and make the above-mentioned first distance l1 large enough, which is beneficial to eliminating the above-mentioned large-angle stray light and also has enough space to place the beam splitter prism P1.

[0052] For example, the second lens L2 has a positive focal power. The incident surface r3 of the second lens L2 is a convex surface, and the exit surface r4 of the second lens L2 is a concave surface; the third lens L3 has a positive focal power. The incident surface r5 of the third lens L3 is a concave surface, and the exit surface r6 of the third lens L3 is a convex surface.

[0053] For example, the second lens group RL further includes a fourth lens L4 and a fifth lens L5. The fourth lens L4 has a positive optical power. The incident surface r7 of the fourth lens L4 is a convex surface, and the exit surface r8 of the fourth lens L4 is a convex surface. The fifth lens L5 has a negative optical power, and the incident surface of the fifth lens L5, which is also the exit surface r8 of the fourth lens L4, is a convex surface.

[0054] It should be noted that Figure 1 r1 to r9 in respectively represent the exit surfaces and incident surfaces of the five lenses, namely the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5. Among them, the fourth lens L4 and the fifth lens L5 are cemented to each other. Therefore, the exit surface r8 of the fourth lens L4 is also the exit surface of the fifth lens L5, and the mark r8 is used here to represent both.

[0055] For example, the fourth lens L5 is cemented to the fifth lens L5. The refractive index of the fourth lens L5 is less than that of the fifth lens L5, and the dispersion degree of the fifth lens L5 is less than the refractive index of the fourth lens L5, so as to correct chromatic aberration by using the combination of the refractive index and dispersion of the materials.

[0056] For example, the endoscope lens assembly 10 further includes a diaphragm STO. The diaphragm STO is located between the second lens L2 and the third lens L3, or the diaphragm STO is located between the first lens L1 and the second lens L2 to reduce off-axis aberrations such as distortion, field curvature, and coma.

[0057] For example, Figure 4 is a schematic structural diagram of another endoscope lens assembly provided by an embodiment of the present invention. Figure 4 The shown endoscope lens assembly 10 includes: a first lens group FL and a second lens group RL. The first lens group FL includes a first lens L1 and a second lens L2. The second lens group RL is arranged axially with the first lens group FL and includes at least one lens (for example, includes a third lens L3), a fourth lens L4, and a fifth lens L5 (the third lens L3, the fourth lens L4, and the fifth lens L5 can all refer to the relevant descriptions in the previous embodiments). The light for imaging enters the second lens group RL after passing through the first lens group FL. The first lens group FL further includes a dimming prism P1. The dimming prism P1 is located between the first lens L1 and the second lens L2 and is configured to change the propagation direction of the light from the first lens L1. In this endoscope lens assembly 10, the propagation direction of the light from the first lens L1 can be changed through the dimming prism P1, so that the incident surface of the light entering the first lens group FL is not perpendicular to the axis, for example, can be substantially parallel to the axis D1, so that the light does not enter the first lens group FL as a whole along the axis from one end of the first lens group FL in the axial direction, but enters the first lens group FL from the side, which can shorten the size of the lens assembly in the axial direction D1.

[0058] Reference Figure 4 , the shape of the dimming prism P1 is triangular, for example, a right triangular prism. The longitudinal cross-sectional shape of the dimming prism P1 is a right triangle. This longitudinal cross-section is a cross-section made along the cross-section direction, and the cross-section direction is perpendicular to the axial direction and parallel to the arrangement direction of the first lens L1 and the dimming prism P1. For example, the incident surface of the dimming prism P1 and the arrangement direction of the dimming prism P1 are perpendicular to the axial direction D1. For example, in Figure 4 , the incident surface of the dimming prism P1 is a plane. In other embodiments, it can also be a curved surface. However, in both cases, the incident surface of the dimming prism P1 and the arrangement direction of the dimming prism P1 are perpendicular to the axial direction D1. For example, reference Figure 4 , the incident surface of the dimming prism P1 is perpendicular to the axial direction D1. The first lens L1 is located on one side of the dimming prism P1 in the longitudinal direction D2 and faces the incident surface of the dimming prism P1. The longitudinal direction D2 is perpendicular to the axial direction D1. The incident surface of the first lens L1 is perpendicular to the axial direction D1 as a whole. At this time, the dimming prism P1 is configured to change the propagation direction of the light incident on the incident surface of the first lens L1 by a target angle, that is, to change the propagation direction of the light emitted from the first lens L1 by the target angle. For example, the target angle is 90°. Thus, the propagation direction of the light from the first lens L1 can be changed by the dimming prism P1, so that the light can enter the incident surface of the first lens group FL and is not perpendicular to the axial direction. Of course, in the embodiments of the present invention, the target angle for changing the propagation direction of the light incident on the incident surface of the first lens L1 is not limited to 90°. A target angle of 90° is convenient for design, especially when the endoscope's end lens includes multiple sub-lenses. It can make the incident surface of the first lens L1 perpendicular to the axial direction and parallel to the surface of the corresponding sub-lens that is close to other sub-lenses in the closed state, which is conducive to the fitting of the opposite surfaces of the multiple sub-lenses in the closed state, reducing the radial size of the end lens composed of multiple closed sub-lenses and reducing the harm to the target object, such as the surgical object.

[0059] For example, the incident surface of the first lens group FL is the incident surface of the first lens L1, that is, Figure 4 the surface corresponding to the reference numeral r1 in

[0060] For example, the light from the target tissue enters the lens assembly 10 of the endoscope through the incident surface of the first lens L1 for imaging. Figure 4, the light incident surface of the first lens group FL can be substantially parallel to the axial direction D1, so that the light does not enter the first lens group FL as a whole along the axial direction from one end of the first lens group in the axial direction D1, but enters the first lens group FL from the side. Thus, the first lens L1 can be located on one side of the dimming prism P1 in the longitudinal direction D2 instead of being arranged along the axial direction D1 with the second lens L2. In this way, the final image plane of the endoscope lens assembly 10 is substantially perpendicular to the arrangement direction of the first lens L1 and the dimming prism P1, and the user's viewing direction is perpendicular to the arrangement direction of the first lens L1 and the dimming prism P1. In this way, on the one hand, the size of the endoscope lens assembly 10 in the axial direction D1 can be shortened, and the volume of the endoscope lens can be reduced. On the other hand, it can be suitable for application scenarios where the light incident surface of the first lens L1 has an angle with the axial direction D1, so that the light incident surface of the first lens L1 can be set on the surface of the endoscope end lens that can flexibly detect a larger range of target tissues, rather than being set on the surface perpendicular to the axial direction D1. For example, the rod body of a general endoscope extends along the direction consistent with the axial direction D1. Therefore, the end lens accommodating the endoscope lens assembly 10 generally enters the cavity where the target tissue is located along the direction consistent with the axial direction D1. In the case where the end lens includes a plurality of sub-lenses that can be opened and closed with each other, during the process of the end lens entering the cavity along the direction consistent with the axial direction D1, the plurality of sub-lenses are in a closed state close to each other, and the plurality of sub-lenses will be unfolded after entering the chamber. Each sub-lens extends along the axial direction D1, and each sub-lens includes the endoscope lens assembly 10. If the light incident surface of the first lens L1 is set to be substantially parallel to the end face of each sub-lens in the axial direction D1, that is, in each sub-lens, the various components of the endoscope lens assembly 10, including the first lens L1 and the dimming prism P1, are all arranged along the axial direction D1 (for example, as shown in Figure 1 ), then, after the plurality of sub-lenses are unfolded in the chamber, the light incident surfaces located at the ends will be away from each other, and it is difficult to be directly opposite to the target tissue, which is not conducive to obtaining an image of the target tissue. Instead, using the endoscope lens assembly 10 shown in Figure 4 , the arrangement direction of the first lens L1 and the dimming prism P1 can have an angle with the axial direction D1, for example, perpendicular to each other. Thus, the light incident surface of the first lens L1 can be set to be substantially parallel to the light incident surfaces of the plurality of sub-lenses that are opposed to each other. The other components of the endoscope lens assembly 10 except the first lens L1 are arranged along their respective corresponding axial directions D1 as shown in Figure 4 in each sub-lens, so that the light incident surface of the endoscope lens assembly 10 can be directly opposite to the target tissue. Even if it moves, it can very easily obtain the light from the target tissue, thus facilitating the acquisition of an image of the target tissue; and, shortening the length of each sub-lens in the axial direction can also make the plurality of sub-lenses move more flexibly in the chamber, meeting the higher requirements for reducing the volume of each sub-lens in the case of a plurality of sub-lenses.

[0061] For example, the range of the angle between the arrangement direction of the dimming prism P1 and the axial direction D1 can be 80° to 100°. For example, this angle is 90°, which is convenient for design and can obtain a better effect of acquiring images. Of course, in the embodiments of the present invention, this angle is not limited to the above-listed range and can be designed according to specific needs.

[0062] For example, the dimming prism P1 has a dimming surface R0, the angle between the dimming surface R0 and the axial direction D1 is 45°, and the incident surface of the first lens L1 is perpendicular to the arrangement direction of the dimming prism P1 and the axial direction D1. In this case, that is, the shape of the longitudinal section of the dimming prism P1 is a right triangle with a 45° apex angle, or in other words, the angle with the optical axis of the second lens L2 along the axial direction D1 is 45°. It is convenient for dimming design, and the effect of adjusting the optical path in practical applications is stable. Of course, in other embodiments, it is not limited that the angle between the dimming surface R0 and the axial direction D1 is 45°, and other angles can also be used in cooperation with the positional relationship between the dimming prism P1 and the first lens L1, as long as it can change the propagation direction of the light incident on the incident surface of the first lens L1 by a target angle such as 90° etc.

[0063] Figure 4 The endoscopic lens assembly 10 shown is the same as Figure 1-2 the other features and technical effects of the endoscopic lens assembly 10 shown, and reference can be made to the description of Figure 1-2 the embodiments shown, which will not be repeated here.

[0064] It should be noted that Figure 4 the embodiments shown may not satisfy Figure 1 the relationship between the first distance and the second distance shown. Of course, Figure 4 the embodiments shown may also satisfy Figure 1 the relationship between the first distance and the second distance shown.

[0065] Figure 5 is a schematic structural diagram of another endoscopic lens assembly provided by an embodiment of the present invention. Figure 5 The endoscopic lens assembly 10 shown is different from Figure 1-2 the endoscopic lens assembly 10 shown in the following aspects. Referring to Figure 5 , for example, the endoscopic lens assembly 10 further includes a first linear polarizer M1, a second linear polarizer M2, and a third linear polarizer M3; the first linear polarizer M1 is located on the incident side of the first lens L1, the second linear polarizer M2 is a λ / 2 wave plate, and is configured to cause a phase delay of π for the light passing through the first linear polarizer M1; the angle between the main axis of the first linear polarizer M1 and the main axis of the second linear polarizer M2 is 15°; the main axis direction of the third linear polarizer M3 is the same as the main axis direction of the first linear polarizer M1.

[0066] After the light from the target tissue passes through the first linear polarizer M1, linearly polarized light with a polarization direction consistent with that of the first linear polarizer M1 is formed. The second linear polarizer M2 is a λ / 2 wave plate. By setting the angle between the principal axis of the second linear polarizer M2 and the linearly polarized light, the rotation of the polarization direction of the linearly polarized light can be achieved. For example, if the angle between the principal axis of the second linear polarizer M2 and the polarization direction of the linearly polarized light after passing through the first linear polarizer M1 is θ, the linearly polarized light rotates by 2θ after passing through a λ / 2 wave plate once. Therefore, when the angle between the principal axis of the first linear polarizer M1 and the principal axis of the second linear polarizer M2 is 15°, after passing through the second linear polarizer M2 once, the polarization direction of the linearly polarized light rotates by 30° after passing through a λ / 2 wave plate once.

[0067] The light from the target tissue is converted into linearly polarized light after passing through the first linear polarizer M1. The polarization direction of this linearly polarized light is consistent with the principal axis of the first linear polarizer M1. Light with a polarization direction consistent with the principal axis direction of the second linear polarizer M2 will all pass through the second linear polarizer M2, and if its polarization direction forms a 90° angle with the principal axis direction of the second linear polarizer M2, it will be absorbed. Among them, the normal light (non-large-angle stray light) for imaging in the linearly polarized light passes through the second linear polarizer M2 and the third linear polarizer M3 at least partially, that is, it normally passes through the second linear polarizer M2 and the third linear polarizer M3. Since the polarization direction of the linearly polarized light passing through the first linear polarizer M1 is consistent with the direction M3, it can normally pass through the third linear polarizer M3 to enter the subsequent optical path for imaging; some large-angle stray light becomes linearly polarized light after passing through the first linear polarizer M1 and then passes through the incident surface of the dimming prism P1 in sequence. Some light is reflected by the surface of the incident surface of the dimming prism P1 and then passes through the second linear polarizer M2 again, and then is reflected by the exit surface r2 (rear surface) of the first lens L1 and passes through the second linear polarizer M2 again. The linearly polarized light passing through the first linear polarizer M1 passes through the second linear polarizer M2 three times in total. Therefore, the direction of this linearly polarized light rotates by 90°. At this time, the stray light in some of the linearly polarized light will be converted into vertically polarized light with a polarization direction forming a 90° angle with the principal axis direction of the first linear polarizer M1. When this light subsequently passes through the third linear polarizer M3, since the angle with the principal axis direction of the third linear polarizer M3 is 90°, it cannot pass through the third linear polarizer M3, thus better achieving the effect of eliminating the interference of the above-mentioned stray light.

[0068] Figure 5 The endoscopic lens assembly 10 shown and Figure 1-2 The other features and technical effects of the endoscopic lens assembly 10 shown are the same, and reference can be made to the description of Figure 1-2 the embodiment shown, which will not be repeated here.

[0069] Figure 5 is in Figure 1On the basis of the illustrated embodiment, a first linear polarizer M1, a second linear polarizer M2, and a third linear polarizer M3 are added. It is also possible to Figure 4 add a first linear polarizer M1, a second linear polarizer M2, and a third linear polarizer M3 to the illustrated embodiment. Figure 6 FIG. is a schematic structural diagram of another endoscope lens assembly provided by an embodiment of the present invention. Figure 6 The illustrated embodiment is to Figure 4 add a first linear polarizer M1, a second linear polarizer M2, and a third linear polarizer M3 to the illustrated embodiment. Figure 6 In the illustrated embodiment, the working principles and functions of the first linear polarizer M1, the second linear polarizer M2, and the third linear polarizer M3 Figure 4 are the same as those in [], and all solve the problem of how to better eliminate the interference of the above-mentioned stray light.

[0070] At least one embodiment of the present invention further provides an endoscope, which includes any one of the endoscope lens assemblies provided by the embodiments of the present invention.

[0071] For example, Figure 7 FIG. is a schematic diagram of an endoscope provided by an embodiment of the present invention. Referring to Figure 7 , an endoscope lens assembly 100 provided by an embodiment of the present invention includes a main body 1, the main body 1 extends along the axial direction D1, and one end of the main body 1 in the axial direction D1 is provided with an end lens 02. The end lens 02 includes, for example, a housing, and the endoscope lens assembly 100 provided by the embodiment of the present invention is arranged inside the housing.

[0072] Figure 8A and Figure 8C FIG. is a schematic diagram of a foldable endoscope including a plurality of sub-lenses in a folded state provided by an embodiment of the present invention; Figure 8B and Figure 8D FIG. is a schematic diagram of a foldable endoscope including a plurality of sub-lenses in an open state provided by an embodiment of the present invention. Referring to Figure 8A-8D , the endoscope 100 includes a main body 1, a plurality of foldable sub-lenses 2, and a driving device 3. The plurality of sub-lenses 2 are located at the front end of the main body 1, and each sub-lens 21 / 22 includes any one of the above-mentioned endoscope lens assemblies 10 and is configured to acquire image information. The front end is the working end. During the operation of the endoscope 10, the front end needs to be inserted into the surgical object, for example, through the natural channel or the artificially created hole channel of the surgical object into the surgical object. Each sub-lens 21 / 22 includes a housing, and the endoscope lens assembly 10 is arranged in the corresponding housing. The driving device 3 (such as Figure 8D), at least partially located within the main body 1, connected to a plurality of sub-lenses 21 / 22, and configured to drive the plurality of sub-lenses 21 / 22 to move relative to the main body 1 so that the plurality of sub-lenses 21 / 22 approach and move away from each other. The plurality of sub-lenses 21 / 22 extend along the axial direction D1 respectively in the closed state, and the main body 1 of the endoscope 100 also extends along the axial direction D1. The plurality of lens assemblies at the front end of the main body can move relative to the main body so that the plurality of lens assemblies approach and move away from each other, and the distance between the plurality of lens assemblies can be changed. Before inserting the front end of the endoscope into a surgical object (such as a human body, an animal body, etc.), the plurality of lens assemblies are closed, and the endoscope 100 is in the Figure 8A and Figure 8C closed state shown, so as to reduce the size of the front end, facilitate the front end of the endoscope to enter the surgical object through the natural passage or the artificially opened hole passage of the surgical object, reduce the harm to the surgical object, and, after inserting the front end of the endoscope into the surgical object, for example, after inserting it into the target tissue or the cavity where the organ to be operated is located, the plurality of lens assemblies can be moved relative to the main body to expand the plurality of lens assemblies, and the endoscope 100 is in the Figure 8B and Figure 8D opened state shown, so as to obtain different types of images through the plurality of lenses respectively. For example, the types of the lenses can be set differently, and images in multiple directions can be obtained through the plurality of lenses. In this way, even if the volume of each lens assembly is large, it is possible to arrange the plurality of lens assemblies at the front end (i.e., the working end) of the same endoscope without increasing the radial size of the endoscope and without increasing the harm to the surgical object (the radial direction is perpendicular to the axial direction), reducing the limitation of the lens size on arranging a plurality of lenses with different functions at the working end of the same endoscope, so that different types of images and images at different angles and different positions can be obtained through the plurality of lens assemblies without increasing the harm to the surgical object, providing more accurate and comprehensive image information for the doctor's diagnosis and treatment.

[0073] When the first lens group FL further includes the above-mentioned dimming prism P1, the dimming prism P1 is located between the first lens L1 and the second lens L2. The incident surface of the dimming prism P1 is perpendicular to the axial direction D1. The first lens L1 is located on one side of the dimming prism P1 in the longitudinal direction and faces the incident surface of the dimming prism P1. The longitudinal direction is perpendicular to the axial direction D1. The incident surface of the first lens L1 is generally perpendicular to the axial direction. When the dimming prism P1 is configured to change the propagation direction of the light emitted from the first lens L1 by a target angle, for each sub-lens, the incident surface of the first lens L1 is substantially parallel to the incident surface of the sub-lens that is opposed to other sub-lenses in the closed state. For example, refer to Figure 8D, taking the first sub-lens 21 as an example, the first sub-lens 21 includes a light incident surface 21a. In the first sub-lens 21, the light incident surface r1 of the first lens L1 is substantially parallel to the light incident surface 21a of the first sub-lens 21, and the light incident surface 21a of the first sub-lens 21 is opposed to the light incident surface 22a of the second sub-lens 22 in the closed state. The same is true for the second sub-lens 22. Thus, in each sub-lens, other components of the endoscope lens assembly 10 except the first lens L1 are arranged along their respective corresponding axial directions D1 as shown in Figure 4 . As a result, the light incident surface of the endoscope lens assembly 10 can be directly facing the target tissue, and even if it moves, it can very easily obtain the light from the target tissue, thereby facilitating the acquisition of an image of the target tissue; moreover, shortening the length of each sub-lens in the axial direction can also enable multiple sub-lenses to move more flexibly in the chamber, meeting the higher requirements for reducing the volume of each sub-lens in the case of multiple sub-lenses.

[0074] In the embodiment of the present invention, the rod body of the endoscope extends along a direction consistent with the axial direction D1. Thus, the end lens accommodating the endoscope lens assembly 10 generally enters the cavity where the target tissue is located along a direction consistent with the axial direction D1. In the case where the end lens includes a plurality of sub-lenses that can be opened and closed with each other, during the process of the end lens entering the cavity along a direction consistent with the axial direction D1, the plurality of sub-lenses are in a closed state close to each other, and the plurality of sub-lenses will be unfolded after entering the chamber. Each sub-lens extends along the axial direction D1, and each sub-lens includes the endoscope lens assembly 10. If the light incident surface of the first lens L1 is set to be substantially parallel to the end face of each sub-lens in the axial direction D1, that is, in each sub-lens, each component of the endoscope lens assembly 10, including the first lens L1 and the dimming prism P1, is arranged along the axial direction D1 (for example, as shown in Figure 1 ), then, after the plurality of sub-lenses are unfolded in the chamber, the light incident surfaces at the end will be away from each other, and it is difficult to directly face the target tissue, which is not conducive to obtaining an image of the target tissue. Instead, using the endoscope lens assembly 10 shown in Figure 4 , the arrangement direction of the first lens L1 and the dimming prism P1 can have an angle with the axial direction D1, for example, perpendicular to each other. Thus, the light incident surface of the first lens L1 can be set to be substantially parallel to the mutually opposed light incident surfaces of the plurality of sub-lenses, and other components of the endoscope lens assembly 10 except the first lens L1 are arranged along their respective corresponding axial directions D1 as shown in Figure 4The axial D1 arrangement shown is such that the light incident surface of the endoscopic lens assembly 10 can face the target tissue directly, and even if it moves, it can very easily obtain light from the target tissue, thus facilitating the acquisition of an image of the target tissue. Moreover, shortening the axial length of each sub-lens can also enable the multiple sub-lenses to move more flexibly in the chamber, meeting the higher requirements for reducing the volume of each sub-lens in the case of multiple sub-lenses.

[0075] For example, here, the structure of the endoscope is introduced by taking two lens assemblies as an example of multiple lens assemblies. In other embodiments, the number of multiple lens assemblies can be more than two, such as three, four, etc., and the number of multiple lens assemblies is not specifically limited.

[0076] For example, as Figure 8A and Figure 8B shown, the main body 1 is rod-shaped and extends along the axial direction D1. The main body 1 includes a rod-shaped main housing 1a that extends along the axial direction D1. The interior of the main housing 1a includes a hollow pipe, which is used as a channel for the driving device 3, a light source channel, a channel for surgical instruments, etc. For example, the main housing can be rigid or flexible. For example, the main housing is a cylindrical tube to reduce friction against the human body.

[0077] The driving device 3 is configured to drive the multiple lens assemblies 21 / 22 to move so as to switch the switchable lens device 2 between the closed state and the open state. For example, referring to Figure 8D , the driving device 3 includes a driving mechanism 30, a first transmission mechanism 31, and a second transmission mechanism 32. The driving mechanism 30 is at least partially located within the main housing 1a and extends along the axial direction D1. The first transmission mechanism 31 is connected to the driving mechanism 30 and the first end of the first sub-lens 21 that is close to the first end of the main body 1 along the axial direction D1. The second transmission mechanism 32 is connected to the driving mechanism 30 and the first end of the second sub-lens 22. The driving mechanism 30 is configured to be movable along the axial direction D1 to drive the first transmission mechanism 31 and the second transmission mechanism 32 to move, thereby driving the first sub-lens 21 and the second sub-lens 22 to move relative to the end of the main body 1.

[0078] For example, as Figure 8C-8D shown, the first sub-lens 21 further includes a first guiding lens 23 located on the first end face 230, and the second sub-lens 22 further includes a second guiding lens 24 located on the second end face 240. In the closed state, the light from the target tissue, the first guiding lens 23, and the second guiding lens 24 form an image. During the process of the endoscope 100 entering the surgical object through the natural channel of the surgical object or an artificial channel (such as an opening) opened on the surgical object, the endoscope 100 is in Figure 8CIn the closed state shown, the first guiding lens 23 and the second guiding lens 24 can transmit the images during the entry process to the doctor's observation end in real time. Through this real-time image, accurate positioning and the safety of the surgical object can be ensured in the closed state. After the openable lens device 2 of the endoscope 100 reaches the appropriate position, the first sub-lens 21 and the second sub-lens 22 are deployed, and the first guiding lens 23 and the second guiding lens 24 can stop working.

[0079] The front end 11 of the main body 1 includes a front end face 11S, and the front end face 11S has a light source opening OP2 communicating with the light source channel 5. For example, in the closed state and the open state, the plurality of lens assemblies expose the light source opening OP2, and the light from the light source exits through the light source channel 5 and the light source opening OP2. For example, when the plurality of lens assemblies are closest to each other, the plurality of lens assemblies still expose the light source opening OP2. As Figure 8A shown, the endoscope 100 further includes a light source introduction channel 1b. The light source introduction channel 1b has a light source inlet OP0. The light source introduction channel 1b is provided on the main body 1 and communicates with the light source channel 5 in the main housing 1a. The light source can be fed into the light source introduction channel 1b through the light source introduction channel 1b, and the light is transmitted to the light source opening OP2 through the light source channel 5 and exits from the light source opening OP2. For example, the light guiding optical fiber enters the light source introduction channel 1b through the light source introduction channel 1b, extends to the light source opening OP2 through the light source channel 5, and the light is transmitted to the light source opening OP2 through the light guiding optical fiber, so that the light exits from the light source opening OP2 to the observation field of the endoscope, that is, exits to the space where the target tissue is located.

[0080] The light from the light source is used for illuminating the field of view and for imaging. For example, the light source includes a visible light source and an infrared light source. Thus, the light from the light source includes visible light and infrared light to excite the target tissue injected with an exogenous fluorescent dye to emit fluorescence, so as to obtain the above-mentioned visible light image and infrared light image simultaneously.

[0081] For other structures of the endoscope 100, they can be designed as needed, and the embodiments of the present invention do not make limitations.

[0082] The above description is only an exemplary implementation manner of the present invention, rather than being used to limit the protection scope of the present invention. The protection scope of the present invention is determined by the appended claims.

Claims

1. An endoscope lens assembly, comprising: A first lens group includes a first lens and a second lens; as well as a second lens group, arranged axially with the first lens group and comprising a third lens, wherein light for imaging enters the second lens group after passing through the first lens group; The second lens and the third lens are sequentially arranged along the axial direction, the first lens is located on a side of the second lens away from the third lens in the axial direction, and light for imaging passes through the first lens, the second lens and the third lens sequentially; Along the overall propagation direction of light in the endoscope lens assembly, the distance between the light exit surface of the first lens and the light entrance surface of the second lens is a first distance, the distance between the light exit surface of the second lens and the light entrance surface of the second lens group close to the first lens group in the axial direction is a second distance, the first distance is greater than twice the second distance, and the first distance is 4.5 mm to 5 mm, and the curvature of the light exit surface of the first lens is R2, -0.72≤R2≤-0.55; The first lens group further includes a dimming prism, the dimming prism is located between the first lens and the second lens, and is configured to change the propagation direction of light from the first lens; The light incident surface of the dimming prism is perpendicular to the axial direction, the first lens is located on one side of the dimming prism in the longitudinal direction and faces the light incident surface of the dimming prism, the longitudinal direction is perpendicular to the axial direction, the light incident surface of the first lens is perpendicular to the axial direction as a whole, and the dimming prism is configured to change the propagation direction of light emitted by the first lens to a target angle; The light propagates from a first position on the light exit surface of the first lens to a second position on the light dimming surface of the light dimming prism along the longitudinal direction as a whole. After being adjusted by the light dimming surface, the propagation direction of the light propagates along the axial direction as a whole to a third position on the light entrance surface of the second lens. The first distance is the sum of the distance between the first position and the second position in the longitudinal direction and the distance between the second position and the third position in the axial direction. The first lens group has negative optical power, and the second lens group has positive optical power; The second lens group also includes a fourth lens and a fifth lens; The first lens has negative optical power, the light incident surface of the first lens is a plane or a convex surface, and the light exit surface of the first lens is a concave surface; The second lens has positive optical power, a light incident surface of the second lens is a convex surface, and a light exit surface of the second lens is a concave surface; The third lens has positive refractive power, the light incident surface of the third lens is a concave surface, and the light exit surface of the third lens is a convex surface; The fourth lens has positive refractive power, the light incident surface of the fourth lens is a convex surface, and the light exit surface of the fourth lens is a convex surface; The fifth lens has negative optical power, the light incident surface of the fifth lens is a convex surface, and the light exit surface of the fifth lens is a convex surface.

2. The endoscope lens assembly according to claim 1, wherein: The target angle is 90°.

3. The endoscope lens assembly according to claim 1, wherein: The second lens group further includes a beam splitter prism, which is located at an end of the second lens group far away from the first lens group in the axial direction and includes a light incident surface, a first light exit surface, and a second light exit surface; The beam splitter prism is configured to disperse light incident on a light incident surface of the beam splitter prism after passing through lenses of the first lens group and the second lens group into visible light and infrared light, wherein the visible light is emitted from the first light exit surface and the infrared light is emitted from the second light exit surface.

4. The endoscope lens assembly according to claim 3, wherein: The first light emitting surface is perpendicular to the axial direction, and the second light emitting surface is perpendicular to the first light emitting surface.

5. The endoscope lens assembly according to claim 3, wherein: It also includes a visible light sensing element and an infrared sensing element. The visible light sensing element is located on the light-emitting side of the first light-emitting surface and is configured to receive the visible light for imaging. The infrared sensing element is located on the light-emitting side of the second light-emitting surface and is configured to receive the infrared light for imaging.

6. The endoscope lens assembly according to any one of claims 1 to 5, further comprising: a first linear polarizer, a second linear polarizer, and a third linear polarizer; The first linear polarizer is located on the light incident side of the first lens, and the second linear polarizer is a λ / 2 wave plate configured to delay the phase of light passing through the first linear polarizer by π; The angle between the principal axis of the first linear polarizer and the principal axis of the second linear polarizer is 15°; The main axis direction of the third linear polarizer is consistent with the main axis direction of the first linear polarizer.

7. The endoscope lens assembly according to claim 1, wherein: The fourth lens is cemented with the fifth lens, the refractive index of the fourth lens is smaller than the refractive index of the fifth lens, and the dispersion of the fifth lens is smaller than the refractive index of the fourth lens.

8. The endoscope lens assembly according to claim 1, further comprising an aperture, wherein: The aperture stop is located between the second lens and the third lens, or the aperture stop is located between the first lens and the second lens.

9. An endoscope, comprising the endoscope lens assembly according to any one of claims 1-8.

10. The endoscope according to claim 9, comprising a main body, a plurality of sub-lenses that can be opened and closed, and a driving device, wherein: The plurality of sub-lenses are located at the front end of the main body, and each of the sub-lenses includes the endoscope lens assembly and is configured to acquire image information; each of the sub-lenses includes a housing, and the endoscope lens assembly is disposed in the housing; The driving device is at least partially located inside the main body, connected to the multiple sub-lenses, and configured to drive the multiple sub-lenses to move relative to the main body so that the multiple sub-lenses are close to and away from each other; the multiple sub-lenses extend axially respectively in a closed state, and the main body of the endoscope also extends along the axial direction.

11. The endoscope according to claim 10, wherein: The first lens group further includes a dimming prism, the dimming prism is located between the first lens and the second lens, the light incident surface of the dimming prism is perpendicular to the axial direction, the first lens is located on one side of the dimming prism in the longitudinal direction and faces the light incident surface of the dimming prism, the longitudinal direction is perpendicular to the axial direction, the light incident surface of the first lens is perpendicular to the axial direction as a whole, and the dimming prism is configured to change the propagation direction of the light emitted by the first lens to a target angle, For each of the sub-lenses, the light incident surface of the first lens is substantially parallel to the light incident surfaces of the sub-lens and other sub-lenses that are aligned with each other in a closed state.

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