A continuous zoom optical system for a stereomicroscope and a stereomicroscope

Abstract

The application provides a continuous zoom optical system and a stereomicroscope for the stereomicroscope, and the optical lens unit comprises, in sequence along a main optical axis, an upper fixed lens group, a compensation lens group, a middle fixed lens group, a zoom lens group and a lower fixed lens group; a variable diaphragm is arranged between the middle fixed lens group and the zoom lens group along the main optical axis; the upper fixed lens group, the compensation lens group, the zoom lens group and the lower fixed lens group are all configured as double lens combinations, the focal length values of the upper fixed lens group and the zoom lens group are negative, and the focal length values of the compensation lens group and the lower fixed lens group are positive; the middle fixed lens group is configured as a double-concave single lens; the compensation lens group and the zoom lens group are axially moved along the main optical axis based on a first zoom fitting curve and a second zoom fitting curve respectively; and the advantages are that the system has smooth magnification, suppresses vignetting phenomenon, and dynamically adjusts the numerical aperture, the depth of field and the light throughput to adapt to different scene requirements.

Description

Technical Field

[0001] This application relates to the field of microscope optical system technology, specifically to a continuous zoom optical system for a stereo microscope and a stereo microscope. Background Technology

[0002] The development of microsurgical techniques has greatly expanded the visual capabilities of the human eye, enabling clinicians to more clearly identify and treat minute lesions, significantly improving the precision of surgical procedures and patient recovery outcomes. Surgical microscopes, with their stereoscopic vision, stable illumination, and precise mechanical structure, have become an indispensable core piece of equipment in microsurgery, driving rapid progress in this field.

[0003] However, current domestically produced high-end surgical microscopes still have significant shortcomings. First, the magnification adjustment mechanism generally adopts a discrete, stepped design, which makes it impossible to achieve a smooth and continuous magnification transition during surgery, affecting the fluency of operation and real-time adaptability. Second, the magnification adjustment process relies on manual operation by the surgeon, forcing the surgeon to interrupt the surgical procedure and put down sterile instruments, which not only prolongs the operation time but also increases the risk of instrument contamination and cross-infection. Third, at a specific magnification setting, the optical system is prone to producing a significant vignetting effect, causing light attenuation and uneven illumination in the edge areas of the field of view, severely weakening the surgeon's ability to observe surrounding tissues. In addition, at a fixed magnification, the system lacks the ability to dynamically adjust key parameters such as depth of field, resolution, and light transmission, making it difficult to flexibly match the needs according to changes in the surgical scenario. For example, shallow depth of field and high resolution are required for delicate suturing, while deep depth of field and wide field of view are required for large-scale tissue exposure.

[0004] These technical limitations restrict the applicability of surgical microscopes in complex clinical settings, reducing surgical efficiency and safety. Summary of the Invention

[0005] The purpose of this application is to provide a continuous zoom optical system and a stereo microscope for stereo microscopes, which have the advantages of smooth magnification, suppression of vignetting, and dynamic adjustment of numerical aperture, depth of field and light transmission of the system, so as to adapt to different scene requirements.

[0006] This application provides a continuous zoom optical system for a stereomicroscope. The system includes an optical lens unit and a variable aperture. The optical lens unit includes an upper fixed lens group, a compensation lens group, a middle fixed lens group, a zoom lens group, and a lower fixed lens group arranged sequentially along the principal optical axis. The variable aperture is positioned between the middle fixed lens group and the zoom lens group along the principal optical axis. The upper fixed lens group, the compensation lens group, the zoom lens group, and the lower fixed lens group are all configured as dual-lens combinations, wherein the focal lengths of the upper fixed lens group and the zoom lens group are negative, and the focal lengths of the compensation lens group and the lower fixed lens group are positive. The middle fixed lens group is configured as a biconcave single lens. The compensation lens group and the zoom lens group move along the principal optical axis based on a first zoom fitting curve and a second zoom fitting curve, respectively, to achieve continuous zoom.

[0007] Furthermore, each binocular lens assembly is formed by cementing two sub-lenses together; the ratio of the focal length of each binocular lens assembly to its individual sub-lenses has a different preset ratio range.

[0008] Furthermore, the upper fixed lens group includes a negative meniscus cemented lens, which is formed by cementing a biconcave lens and a biconvex lens; the compensation lens group includes a biconvex cemented lens, which is formed by cementing a negative meniscus lens and a biconvex lens; the zoom lens group includes a biconcave cemented lens, which is formed by cementing a biconcave lens and a positive meniscus lens; and the lower fixed lens group includes a biconvex cemented lens, which is formed by cementing a biconvex lens and a positive meniscus lens.

[0009] Furthermore, the specified focal length ranges for the upper fixed lens group, compensating lens group, middle fixed lens group, zoom lens group, and lower fixed lens group are respectively... .

[0010] Furthermore, the preset ratio ranges for the focal length ratios of the upper fixed lens group, the lower fixed lens group, and their respective sub-lenses are as follows: The preset ratio ranges for the ratio of the focal length of the compensating lens group to that of its individual sub-lenses are as follows: The preset ratio ranges for the focal length ratios of the zoom lens group and its individual sub-lenses are as follows: .

[0011] Furthermore, the total optical length of the system is less than or equal to 100 mm; the total optical length refers to the axial distance measured along the principal optical axis from the incident surface of the upper fixed lens group near the incident side of the light to the exit surface of the lower fixed lens group near the exit side of the light.

[0012] Furthermore, the microscope includes: a main microscope tube, a continuous zoom optical system, a zoom microscope tube, and a transmission system; the main microscope tube includes two independent optical paths symmetrically arranged based on the central axis of the main microscope tube; in either optical path, the continuous zoom optical system is disposed inside the main microscope tube, and the transmission system is disposed on the zoom microscope tube, which is nested on the outer wall of the main microscope tube based on the principal optical axis; the outer wall of the zoom microscope tube has a cam groove based on a first cam curve and a second cam curve, and the outer wall of the main microscope tube has an opening groove corresponding to the cam groove through it parallel to the principal optical axis; the transmission system is connected to the compensation lens group and the zoom lens group in sequence through the opening groove and the cam groove, so as to drive the compensation lens group and the zoom lens group to move axially along the principal optical axis; wherein, the first zoom fitting curve is obtained by fitting a smooth mechanical curve function to obtain the first cam curve; the second zoom fitting curve is obtained by fitting a smooth mechanical curve function to obtain the second cam curve.

[0013] Furthermore, the cam groove includes a first cam groove formed based on a first cam curve, the opening groove includes a first opening groove formed corresponding to the first cam groove, and the transmission system includes a first sliding screw; the sliding end of the first sliding screw is installed in the first cam groove, and the fixed end of the first sliding screw is fixedly connected to the compensation lens group through the first opening groove; similarly, the cam groove includes a second cam groove formed based on a second cam curve, the opening groove includes a second opening groove, the transmission system includes a second sliding screw, the sliding end of the second sliding screw is installed in the second cam groove, and the fixed end of the second sliding screw is fixedly connected to the zoom lens group.

[0014] Furthermore, the transmission system includes a zoom gear, which is fixedly connected to the zoom lens barrel; the zoom gear drives the zoom lens barrel to rotate based on the main optical axis, the first cam groove presses against the first sliding screw, and the first sliding screw drives the compensation lens group to move axially along the first open groove; similarly, the second sliding screw drives the zoom lens group to move axially along the second open groove.

[0015] Furthermore, a positioning component is provided inside the main lens barrel. The positioning component is connected to the sliding end of the first sliding screw and the sliding end of the second sliding screw, and is used to eliminate the reverse clearance between the first sliding screw, the second sliding screw and the cam groove when the zoom lens barrel changes the rotation direction.

[0016] In summary, this application provides a continuous zoom optical system for a stereomicroscope. In the stereomicroscope, the various lens groups and the variable aperture in the optical lens unit cooperate with each other. By compensating for the axial movement of the lens group and the zoom lens group based on the zoom fitting curve, a magnification of 0.406x to 2.463x under parfocal conditions is achieved. Moreover, the zooming is smooth and continuous, effectively suppressing vignetting throughout the zooming stroke and ensuring the uniformity of illumination at the edge of the field of view. In addition, the numerical aperture, depth of field, and light transmission of the system can be dynamically adjusted during the zooming process to adapt to different observation needs, further improving the smoothness and real-time adaptability of surgical operations. Attached Figure Description

[0017] Figure 1 This is a schematic diagram showing the positions of each lens group in the system provided in the embodiment of the present invention at different magnifications.

[0018] Figure 2 This is a schematic diagram of the first and second zoom fitting curves provided in an embodiment of the present invention.

[0019] Figure 3 The structure matrix dot diagram of the continuous zoom optical system provided in the embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of a microscope provided in an embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram of the first cam curve and the second cam curve provided for an embodiment of the present invention.

[0022] Figure 6 This is a schematic diagram illustrating the error between the theoretical value of the cam curve and its actual application, as provided in the embodiments of the present invention.

[0023] Figure 7 This is a schematic diagram of a zoom lens barrel with a cam groove provided in an embodiment of the present invention.

[0024] Figure 8 This is a schematic diagram of the optical assembly of a stereomicroscope provided in an embodiment of the present invention.

[0025] In the diagram, D1 represents the entrance pupil and the upper fixed lens group. The air gap between them; D2 is the upper fixed lens group. With compensating lens group The air gap between them; D3 is the compensating lens group. With fixed lens group The air gap between them; D4 is the central fixed lens group. The air gap between the aperture stop and the zoom lens group; D5 is the aperture stop (Stop) and zoom lens group. The air gap between them; D6 is the zoom lens group. With lower fixed lens group The air gap between them; D7 is the lower fixed lens group. The air gap between the exit pupil and the exit pupil; biconcave lens and biconvex lens It is an upper fixed lens group Sub-lens; negative meniscus lens and biconvex lens It is a compensating lens group Sub-lens; biconcave lens And positive meniscus lens It is a zoom lens group Sub-lens; biconvex lens And positive meniscus lens It is a lower fixed lens group Sub-lens; Used to indicate a lens The center thickness, and and Corresponding to sub-lenses and The center thickness; Used to indicate a lens The center thickness, and and Corresponding to sub-lenses and The center thickness; Used to indicate a lens The center thickness; Used to indicate a lens The center thickness, and and Corresponding to sub-lenses and The center thickness; Used to indicate a lens The center thickness, and and Corresponding to sub-lenses and The center thickness; 1-Upper fixed assembly, 2-Compensation assembly, 3-Intermediate fixed assembly, 4-Magnification assembly, 5-Electric adjustable aperture, 6-Lower fixed assembly, 7-Knurled set screw, 8-ZOOM lens barrel, 9-Cam retaining ring, 10-Spring, 11-Magnification gear, 12-Pulley screw, 13-Cam lens barrel, 101-Objective lens assembly, 102-Magnification assembly, 103-Eyepiece assembly, 104-Secondary lens assembly, 105-Illumination assembly. Detailed Implementation

[0026] The technical solutions in specific embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The components described and shown in the accompanying drawings of the present invention can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0027] The common English terms or letters used in this invention for the purpose of clarity are for illustrative purposes only and are not intended to be limiting or specific. They should not be used to limit the scope of protection of this invention based on their Chinese translations or specific letters.

[0028] In traditional surgical microscopes, the step-like design for magnification adjustment results in a discontinuous zoom process, making a smooth transition impossible. Magnification adjustment requires manual operation, forcing surgeons to put down their surgical instruments to make adjustments, increasing the risk of contamination in the surgical area. Furthermore, at certain magnifications, the optical system exhibits vignetting, causing a decrease in relative illumination at the edge of the field of view, affecting the consistency of image quality. Moreover, at fixed magnifications, parameters such as numerical aperture, depth of field, and light transmission cannot be adjusted independently, making it difficult to adapt to the needs of different surgical scenarios, thus limiting the system's flexibility and operational efficiency.

[0029] For example, in neurosurgical microsurgery, when doctors observe tiny structures, they need to adjust the microscope magnification. However, because the magnification adjustment is stepped, doctors cannot precisely adjust it to the required magnification and must manually operate the zoom mechanism, causing the surgical instruments to be temporarily removed, increasing the possibility of the sterile environment being compromised. At the same time, at a certain magnification, vignetting appears at the edge of the field of view, making it impossible for doctors to see the surrounding tissues clearly, increasing the risk of missing tiny lesions. In addition, because the depth of field cannot be adjusted, the image clarity cannot be maintained when the tissue depth changes, seriously affecting the precision and safety of the surgery.

[0030] If the above problems are not solved, the imaging quality during surgery will be unstable, the frequency of surgical interruptions will increase, and the workload of doctors will be increased, which will affect the accuracy and safety of the surgery. The hazy phenomenon will prevent doctors from fully observing the surgical area, increasing the risk of misdiagnosis or operational errors. Manual operation of magnification adjustment will prolong the operation time and may introduce external contaminants, which may harm the patient's health. The problem of uncontrollable parameters makes it difficult for the system to adapt to diverse surgical needs, limiting the application scenarios of microscopy.

[0031] In one embodiment, a continuous zoom optical system for a stereomicroscope is proposed. The system includes an optical lens unit and a variable aperture. The optical lens unit includes an upper fixed lens group, a compensation lens group, a middle fixed lens group, a zoom lens group, and a lower fixed lens group arranged sequentially along the principal optical axis. The variable aperture is positioned between the middle fixed lens group and the zoom lens group along the principal optical axis. The upper fixed lens group, the compensation lens group, the zoom lens group, and the lower fixed lens group are all configured as dual-lens combinations, wherein the focal lengths of the upper fixed lens group and the zoom lens group are negative, and the focal lengths of the compensation lens group and the lower fixed lens group are positive. The middle fixed lens group is configured as a biconcave single lens. The compensation lens group and the zoom lens group move axially along the principal optical axis based on a first zoom fitting curve and a second zoom fitting curve, respectively, to achieve continuous zoom.

[0032] For ease of understanding, the following explains some key terms in this embodiment: A stereomicroscope is a type of microscope with a binocular observation system. It provides the observer with a stereoscopic vision by offering slightly different images to the left and right eyes. This type of microscope is often used in scenarios requiring fine manipulation and three-dimensional perception, such as surgery, precision assembly, and materials analysis.

[0033] A continuous zoom optical system is an optical system that can smoothly change the magnification while keeping the focal plane constant, i.e., under parfocal conditions.

[0034] The principal optical axis is the central axis of all lenses in an optical system, along which light rays typically propagate. The setting and movement of optical elements are all based on this axis.

[0035] The optical lens unit is the core component of a continuous zoom optical system. It consists of multiple lens groups and is responsible for converging, diverging, imaging, and zooming light.

[0036] A variable aperture is a device that can adjust the size of the light-passing aperture. By changing the aperture size, the amount of light entering the optical system can be controlled, thereby affecting the brightness, depth of field, and resolution of the image.

[0037] The upper fixed lens group, compensation lens group, middle fixed lens group, zoom lens group, and lower fixed lens group are specific lens groups within an optical lens unit. The fixed lens group maintains its position during zooming, meaning it does not move along the principal optical axis. The movable lens groups, including the compensation lens group and the zoom lens group, move along the principal optical axis to achieve zooming and image plane shift calibration functions. "Upper," "middle," and "lower" are defined along the propagation direction of light from incident to exit.

[0038] A dual-lens combination is an optical element composed of two lenses. This combination is often used to correct aberrations, improve image quality, and achieve specific optical functions.

[0039] The first and second zoom fitting curves are mathematical curves used to guide the axial movement trajectories of the compensation lens group and the zoom lens group. These curves have been precisely calculated and optimized to ensure that the system remains parfocal and maintains good imaging performance throughout the zoom process.

[0040] This embodiment provides a continuous zoom optical system for a stereo microscope, wherein the designed wavelength of the continuous zoom optical system is [wavelength value missing]. ~ The visible light band can match the imaging characteristics of human tissues and the visual sensitivity of the human eye in clinical surgery, avoiding damage to tissues or imaging failure caused by non-visible light bands. The system aims to solve the technical problems of discontinuous magnification adjustment, manual operation risk, vignetting problem and uncontrollable parameters in the existing technology.

[0041] Specifically, the optical lens unit is responsible for light transmission, imaging, zooming, and calibration, while the variable aperture is used to adjust the amount of light and control imaging parameters.

[0042] The upper fixed lens group, compensating lens group, zoom lens group, and lower fixed lens group are all dual-lens assemblies. A dual-lens assembly can consist of two independent lenses mechanically fixed without adhesive layers, for example, by using spacers to maintain a fixed distance, or by mechanical clamping; alternatively, it can be fixed with adhesive layers, such as optically specialized adhesives, including traditional high-temperature optical bonding and epoxy bonding. This dual-lens assembly aims to provide superior aberration correction capabilities compared to a single lens.

[0043] The fixed lens group is a biconcave single lens. Biconcave single lenses have the ability to diverge light rays, and in optical systems they can be used to adjust the convergence of light beams or as aberration correction elements.

[0044] The focal lengths of the upper fixed lens group and the zoom lens group are negative, while the focal lengths of the compensation lens group and the lower fixed lens group are positive. This configuration of positive and negative focal lengths is used to achieve continuous zoom and parfocal conditions. Specifically, the desired focal length can be obtained by selecting lenses with specific radii of curvature and material refractive indices, or by combining different types of single lenses to form a dual-lens combination with the desired focal length characteristics.

[0045] The axial movement trajectories of the compensation lens group and the zoom lens group follow the first zoom fitting curve and the second zoom fitting curve, respectively, and the two are synchronized to achieve smooth and continuous zooming. Specifically, the core function of the first and second zoom fitting curves is to define the movement law of the two lens groups along the principal optical axis. In actual execution, precise guidance can be provided by a linear guide rail, and the drive mechanism drives the two lens groups to move along the principal optical axis. Moreover, the motion law of the drive mechanism can be pre-programmed to accurately reproduce the movement trajectory corresponding to the two fitting curves.

[0046] This embodiment presents a continuous zoom optical system for a stereomicroscope. When observing tissue structures of different sizes, the compensation lens group and the zoom lens group in the optical lens unit move axially along the principal optical axis according to preset first and second zoom fitting curves. This movement is smooth and continuous, ensuring that the image remains clear throughout the zoom process, avoiding the visual interruption and refocusing troubles caused by traditional stepped zoom. Therefore, when switching from macroscopic observation to microscopic detail observation, there is no need to interrupt the operation; seamless magnification switching can be achieved simply by driving the compensation lens group and the zoom lens group in conjunction with the system.

[0047] Furthermore, the variable aperture is cleverly positioned between the fixed lens group and the zoom lens group. When vignetting is observed at the image edges at a specific magnification, or when it is necessary to adjust the depth of field to observe tissues at different depths, the aperture size of the variable aperture can be adjusted for observation. Specifically, when the aperture is appropriately reduced to effectively decrease stray light entering the optical system, vignetting is eliminated, ensuring uniform illumination across the entire field of view. Simultaneously, the adjustment of the aperture allows for optimization of depth of field and resolution according to actual needs, matching different surgical scenarios and solving the problem of uncontrollable parameters at fixed magnification in traditional microscopes.

[0048] In summary, this embodiment achieves parfocal conditions by axially shifting the compensation lens group and the zoom lens group based on a preset fitting curve. ~ The continuous zoom allows for smooth adjustment of magnification without interrupting observation, improving operational fluency and efficiency. Furthermore, precise control of the coordinated movement of the compensation lens group and the zoom lens group provides a foundation for automated or semi-automated zooming, reducing the need for manual intervention and lowering the risk of contamination during surgery. Moreover, positioning the variable aperture between the fixed lens group and the zoom lens group, this optimized aperture position, combined with the specific configuration of the lens groups, effectively controls the beam path, reduces light obstruction, eliminates vignetting, and ensures uniform brightness and clarity across the entire field of view. The introduction of the variable aperture allows users to dynamically adjust the aperture diameter according to actual needs, greatly enhancing the system's adaptability and functionality.

[0049] Furthermore, each binocular lens assembly is formed by cementing two sub-lenses together; the ratio of the focal length of each binocular lens assembly to that of its individual sub-lenses has a different preset range.

[0050] A dual-lens assembly consists of two sub-lenses joined together using a cementing process. Cementing refers to bonding two or more sub-lenses together with optical adhesive to form a single lens assembly. Cemented lenses offer higher structural stability and are less susceptible to environmental changes. The cemented structure effectively reduces the air interface between the lenses, thereby reducing light reflection loss at the air-glass interface and improving light energy utilization. Furthermore, cemented lenses allow for more precise control over the relative positions of the lenses, reducing assembly errors.

[0051] Specifically, the lenses of each lens group can be made of conventional, high-volume environmentally friendly materials, and the two sub-lenses are bonded together using UV-cured optical adhesive or thermosetting optical adhesive to ensure that the adhesive layer is uniform and free of air bubbles in order to maintain optical performance; or optical contact can be used, that is, the surfaces of the two sub-lenses are made to achieve extremely high flatness through precision grinding and polishing, and then directly bonded together under the intermolecular forces.

[0052] By setting different preset ratio ranges for each pair of lenses, the optical performance of each lens group can be optimized in a targeted manner. Specifically, in a continuous zoom optical system, different lens groups perform different optical functions and have different aberration correction requirements. By setting the focal length ratio of each pair of lenses and its individual sub-lenses, various aberrations such as chromatic aberration, spherical aberration, and field curvature can be precisely balanced, ensuring that the system maintains excellent image quality, stable optical performance, and consistent system parameters throughout the entire zoom range. This provides high-quality and highly stable continuous zoom functionality for stereo microscopes.

[0053] In practical applications, the specific lens type of each lens group may affect aberration accumulation, vignetting, or imaging quality during continuous zooming, thus affecting the system's parfocality and edge illumination in the visible light band.

[0054] Furthermore, the upper fixed lens group Including negative meniscus cemented lenses, which are composed of biconcave lenses. and biconvex lens Cementing formation; compensating lens group Including biconvex cemented lenses, which consist of negative meniscus lenses. and biconvex lens Cemented construction; zoom lens group Including biconcave cemented lenses, which are composed of biconcave lenses And positive meniscus lens Adhesive bonding; lower fixed lens group Including biconvex cemented lenses, which are composed of biconvex lenses And positive meniscus lens Adhesion formation, specific composition as follows Figure 1 As shown, and the fixed lens group in the middle. It is a biconcave single lens.

[0055] Among them, the negative meniscus cemented lens with a fixed upper lens is a composite lens made of two sub-lenses cemented together. It exhibits negative focal length characteristics and is typically concave on one side and convex on the other, thinner in the center and thicker at the edges. Biconcave lenses are mainly used to provide the ability to diverge light and introduce negative spherical aberration, while biconvex lenses are used to provide the ability to converge light and introduce positive spherical aberration. By rationally designing the curvature and materials of these two sub-lenses, spherical aberration, coma, and axial chromatic aberration of the system can be effectively corrected, especially in the initial stage of light entering the optical system, providing a stable optical foundation for subsequent zooming processes.

[0056] A biconvex cemented lens with a compensating lens group is a composite lens composed of two sub-lenses cemented together. It exhibits a positive focal length overall, and both outer surfaces are convex. The negative meniscus lens provides additional aberration correction, particularly for field curvature and distortion, while the biconvex lens primarily provides converging power. This combination dynamically compensates for aberration changes caused by other moving lens groups during zooming, ensuring image sharpness and stability throughout the zoom range.

[0057] If the fixed lens group is a biconcave single lens, its focal length is negative. Its function is to act as an intermediate relay, assist in optical path alignment, and shape the light beam to ensure that the light can correctly enter the zoom lens group.

[0058] A biconcave cemented lens in a zoom lens group is a composite lens composed of two sub-lenses cemented together. It exhibits a negative focal length overall, with both outer surfaces being concave. The biconcave lens primarily provides divergence and a negative focal length, while the positive meniscus lens is used for fine-tuning the light and precisely correcting aberrations, particularly field curvature and distortion. This combination, through axial movement during zooming, effectively changes the overall focal length of the system while suppressing vignetting and ensuring uniform illumination at the field of view edges at different zoom levels.

[0059] A biconvex cemented lens with a fixed lower lens group is a composite lens composed of two sub-lenses cemented together. It exhibits positive focal length characteristics overall, and both outer surfaces are convex. The biconvex lens primarily converges light rays, while the positive meniscus lens further corrects residual aberrations, particularly by precisely controlling the parallelism or convergence of the outgoing rays to ensure final image quality. This combination, serving as the system's output, ensures uniform light distribution onto the imaging plane, improves relative illumination at the field of view edges, and maintains good resolution.

[0060] These specific lens combinations work together to ensure that the entire continuous zoom optical system maintains excellent parfocality, high resolution, and uniform edge illumination in the visible light band, regardless of the zoom level, thereby significantly improving the imaging quality and user experience of stereomicroscopes.

[0061] Furthermore, the specified focal length ranges for the upper fixed lens group, compensating lens group, middle fixed lens group, zoom lens group, and lower fixed lens group are respectively... Focal length can be precisely controlled by selecting a combination of glass materials with specific curvature and refractive index, or it can be fine-tuned by adjusting the lens thickness, diameter, and air gap between lenses to meet design requirements. It can also be further refined by applying a black matte varnish to the cylindrical surface (the outer circumferential side of the lens) and coating the polished surface (the front and back curved / cemented surfaces of the lens) with a coating. Visible light antireflection coatings are used to reduce reflection loss and increase light transmittance. The front curved surface is defined as the light incident surface; the back curved surface is defined as the light exit surface.

[0062] Specifically, the negative focal length range of the upper fixed lens group effectively controls the initial path and divergence of the incident light, laying the foundation for subsequent optical processing. The positive focal length range and axial movement capability of the compensation lens group enable it to dynamically cancel aberrations introduced by the zoom lens group during zooming and precisely maintain the parfocal condition of the image, thereby ensuring image sharpness and stability throughout the zoom range. The negative focal length range of the middle fixed lens group acts as an intermediate relay, further assisting in optical path alignment and beam shaping, avoiding imaging shift and resolution degradation. The negative focal length range and axial movement of the zoom lens group are the core of achieving continuous zoom, smoothly adjusting the magnification by changing the total focal length of the system. Finally, the positive focal length range of the lower fixed lens group fixes the output optical path, performing fine correction on the final imaging light, ensuring a balance between the quality and light transmission of the final image.

[0063] By precisely defining the focal lengths of the upper fixed lens group, compensation lens group, middle fixed lens group, zoom lens group, and lower fixed lens group, and combining the specific structure and movement mechanism of each lens group, the system can maintain excellent image quality throughout the entire zoom range, significantly reducing vignetting and ensuring image sharpness and stability. Furthermore, this approach allows for precise control and adjustment of key optical parameters such as numerical aperture and depth of field during continuous zooming, greatly enhancing the applicability and flexibility of the stereomicroscope and meeting the needs of various application scenarios.

[0064] Furthermore, the preset ratio ranges for the focal length ratios of the upper fixed lens group, the lower fixed lens group, and their respective sub-lenses are as follows: The preset ratio ranges for the ratio of the focal length of the compensating lens group to that of its individual sub-lenses are as follows: The preset ratio ranges for the focal length ratios of the zoom lens group and its individual sub-lenses are as follows: .

[0065] The preset ratio range of the focal length ratio of the upper fixed lens group and its individual sub-lenses aims to precisely control the optical characteristics of the lens group, such as its ability to correct aberrations like chromatic aberration and spherical aberration. The preset ratio range of the focal length ratio of the lower fixed lens group and its individual sub-lenses aims to optimize its converging or diverging characteristics of outgoing light rays and correct aberrations. The preset ratio range of the focal length ratio of the compensation lens group and its individual sub-lenses is crucial for maintaining parfocality and correcting aberrations during zooming. The preset ratio range of the focal length ratio of the zoom lens group and its individual sub-lenses directly affects the smoothness of zooming, the uniformity of image quality, and the control of vignetting. This can be achieved through computer-aided design and optical simulation software, iteratively optimizing the parameters of the sub-lenses to ensure that their ratios are within the preset range and meet zoom performance indicators. Alternatively, high-precision optical element manufacturing technology can be used to ensure the surface accuracy and thickness tolerance of the sub-lenses to achieve a precise focal length ratio.

[0066] By precisely setting the sub-lens ratio range of each lens group in the dual-lens combination, the optical characteristics of each lens group can be finely controlled. This refined parameter control enables the lens groups to more accurately achieve the expected optical functions when working together, thereby maintaining excellent image sharpness, reducing aberrations, effectively suppressing vignetting, and ensuring the smoothness of the continuous zoom process and the stability of image quality throughout the entire continuous zoom range.

[0067] In one specific embodiment, the air gap and each single lens - The radius of curvature, thickness, and corresponding refractive index N are shown in Table 1; where The thickness NA refers to the portion of the air gap that changes as the moving lens group moves; no specific value is specified here.

[0068] Table 1. Specific parameters of a continuous zoom optical system for a stereo microscope. Table 1 The continuous zoom optical system shown in Table 1 uses lenses. - The system's total focal length approaches infinity by rationally arranging the apertures along the main optical axis and precisely matching the air gaps D1-D7. It is also equipped with an adjustable aperture, which can achieve continuous zoom from 0.406X to 2.463X in parfocal mode. Furthermore, key optical parameters such as numerical aperture, depth of field, and light transmission are all controllable and adjustable in real time, and there is no vignetting phenomenon throughout the entire zoom range.

[0069] At different magnifications, the position of the moving lens group is as follows: Figure 1 As shown, the fitting curves for the first zoom level corresponding to the compensating lens group and the fitting curves for the second zoom level corresponding to the zoom lens group are as follows: Figure 2 As shown in the figure, the horizontal axis of the curve represents the magnification, and the vertical axis represents the movement distance, with the unit being mm.

[0070] Figure 3 The structure matrix dot plot generated in the optical software Zemax OpticStudio 17 for the above-mentioned continuous zoom optical system is used to evaluate the imaging quality of the system at different zoom levels and different fields of view. The position of the dot plot is referenced to the image point of the principal ray.

[0071] In this diagram, the blue plus sign and the number 0.486133, the green square and the number 0.588, and the red triangle and the number 0.656273 correspond to different visible light wavelengths. The spots in the image are matched with the aforementioned visible light wavelengths by their corresponding colors. For blue light, Yellow-green light It emits red light, covering the visible light band that the human eye is sensitive to.

[0072] Structures 1 to 9 represent the nine magnification configurations of this continuous zoom optical system, corresponding to... to Different usage ratios.

[0073] 0.0000 (degrees), 1.0000 (degrees), and 2.0000 (degrees) represent the object-side field of view; 0.0000 (degrees) is the on-axis field of view, indicating that the object point is located at the center of the optical axis; 1.0000 (degrees) and 2.0000 (degrees) are the off-axis field of view, indicating that the object point is located at different positions on both sides of the optical axis; the three together cover the effective observation field of view of the lens group.

[0074] The colored spots in the diagram represent the collection of points on the image plane where light rays of different wavelengths emitted from the same object point fall after passing through the system at the corresponding field of view and magnification. This is the core of the dot matrix diagram. The circles outside the spots represent the Airy disk radius. The Airy disk is the smallest spot size under the diffraction limit of an optical system and is the benchmark for judging whether the image quality meets the standard. The unit of measurement in the diagram is milliradians (mrad), and the Airy disk radius is... .

[0075] Figure 3 The imaging quality of this continuous zoom optical system is visually demonstrated: at all zoom levels, all effective fields of view, and the entire visible light spectrum, the spots in the dot plot are all smaller than the Airy disk radius, indicating that the lens group achieves the diffraction limit across the entire range of use and can provide the microscope system with good optical resolution, parfocality, minimal distortion, and uniform illumination.

[0076] In the process of achieving continuous magnification adjustment in a continuous zoom optical system, an excessively large system size may result in a bulky and inconvenient microscope, increasing operational complexity and the risk of contamination.

[0077] Furthermore, the total optical length of the system is less than or equal to The total optical length refers to the axial distance measured along the principal optical axis from the incident surface of the upper fixed lens group near the light incident side to the exit surface of the lower fixed lens group near the light exit side.

[0078] By strictly limiting the axial dimensions of the entire continuous zoom optical system along the principal optical axis, a compact system design is achieved, thereby reducing the overall size and weight of the microscope. For example, the structural design of the lens groups can be optimized by selecting high-refractive-index materials, using aspherical lenses, or employing a more compact lens arrangement to shorten the axial length of each lens group while maintaining optical performance. Furthermore, the air gaps between the lens groups can be finely adjusted to maximize the reduction of the overall axial dimensions while meeting optical imaging requirements such as aberration correction and zoom range.

[0079] For measuring the total optical length, for example, in optical design software, models of the incident surface of the foremost lens of the upper fixed lens group and the exit surface of the last lens of the lower fixed lens group can be accurately created, and the coordinate difference between these two surfaces along the principal optical axis can be directly read as the total optical length for design verification. In actual production and quality control, a high-precision laser rangefinder or coordinate measuring machine can be used to directly measure the physical distance between the incident surface of the foremost lens of the upper fixed lens group and the exit surface of the last lens of the lower fixed lens group on the assembled optical system, ensuring that this distance is strictly controlled within a specified range. Within.

[0080] The total optical length of the continuous zoom optical system is strictly limited to... The miniaturization, achieved by reducing the size or weight of stereomicroscopes and defining their measurement methods, has significantly reduced their overall dimensions and weight. This compact design greatly enhances the microscope's portability and ease of operation, allowing surgeons greater flexibility in adjusting the equipment during microsurgery and reducing the operational burden caused by bulky equipment. Simultaneously, the smaller footprint of the microscope reduces its potential contact with the surrounding environment, effectively minimizing the risk of contamination during surgery. This miniaturization, achieved while maintaining continuous zoom functionality and excellent optical performance, makes stereomicroscopes more practical and adaptable in clinical applications, providing medical professionals with a more efficient and safer operating experience.

[0081] Based on the aforementioned continuous zoom optical system, this application proposes a stereomicroscope, a microscopic observation device that provides stereoscopic vision and is typically used in scenarios requiring fine manipulation and three-dimensional perception. In one embodiment, Figure 4 This is a schematic diagram of an overall microscope. The stereo microscope mainly includes: objective lens assembly 101, zoom assembly 102, eyepiece assembly 103, secondary mirror assembly 104, and illumination assembly 105; wherein the zoom assembly is used to house a continuous zoom optical system.

[0082] The accuracy of the movement of the compensation lens group and the zoom lens group is the core factor that determines the zoom performance and imaging stability of a continuous zoom optical system. Therefore, the design of the mechanical transmission structure that drives the movement of the two lens groups becomes a key link in ensuring the accuracy of the system.

[0083] In this embodiment, the microscope includes a main microscope tube, a continuous zoom optical system, a zoom microscope tube, and a transmission system. The main microscope tube includes two independent optical paths symmetrically arranged along its central axis. In either optical path, the continuous zoom optical system is located inside the main microscope tube, and the transmission system is located on the zoom microscope tube, which is nested within the outer wall of the main microscope tube based on the principal optical axis. The outer wall of the zoom microscope tube has cam grooves formed based on a first cam curve and a second cam curve. The outer wall of the main microscope tube has an opening groove parallel to the principal optical axis, corresponding to the cam groove. The transmission system sequentially connects to the compensation lens group and the zoom lens group through the opening groove and the cam groove, thereby driving the compensation lens group and the zoom lens group to move axially along the principal optical axis. The first zoom fitting curve is obtained by fitting a smoothed mechanical curve function to obtain the first cam curve; the second zoom fitting curve is obtained by fitting a smoothed mechanical curve function to obtain the first cam curve.

[0084] The main microscope tube is the core structure of the microscope. It can be integrally formed from a high-strength metal alloy or assembled from multiple modular components. Its internal structure is designed to precisely fix optical elements and provide light transmission paths. The continuous zoom optical system is the optical component that enables the microscope's continuous zoom function. Its specific structure can be referred to in the continuous zoom optical system of the above embodiment, including optical lens units and a variable aperture. The compensation lens group and the zoom lens group are key movable components for achieving continuous zoom. The zoom tube is an external annular or cylindrical component, usually fitted outside the main microscope tube, and can rotate or slide relative to the main microscope tube. The transmission system is a mechanical mechanism responsible for converting external operations into precise axial movement of the compensation lens group and the zoom lens group, designed to ensure that the movement trajectory of the lens group precisely matches the preset zoom fitting curve. Inside the main microscope tube, two independent optical paths are symmetrically arranged based on its central axis, with off-axis distances set to... This ensures stereoscopic imaging during binocular observation. These two optical paths can be designed as parallel or slightly converging channels, each accommodating an identical set of optical components.

[0085] The continuous zoom optical system can be securely mounted inside the main lens barrel using threaded connections, snap-fit ​​fasteners, or precision clamps to ensure the stability and alignment accuracy of the optical system. The cam groove on the outer wall of the zoom lens barrel can be formed using CNC milling, laser engraving, or precision molding. Its contour is precisely calculated and designed based on the first and second cam curves to ensure that the transmission system can generate the required axial displacement when moving within the groove. The opening slot on the outer wall of the main lens barrel can be formed using wire cutting, milling, or stamping. It is parallel to the main optical axis and corresponds to the position of the cam groove on the zoom lens barrel, allowing the connecting components of the transmission system to pass through. The transmission system, through components such as pins, rollers, or sliders, passes through the opening slot of the main lens barrel and the cam groove on the zoom lens barrel, and engages with the fixing components of the moving lens group in the continuous zoom optical system, thereby converting the rotational motion of the zoom lens barrel into precise axial movement of the compensation lens group and the zoom lens group.

[0086] Specifically, the formulas for the first cam curve (1) and the second cam curve (2) are as follows: (1) (2) in, Figure 5 The diagram shows the first cam curve (1) and the second cam curve (2), where x is the horizontal axis representing the circumferential value of the zoom lens barrel, with its maximum value being the circumference of the lens barrel; and the vertical axis representing the height of the zoom lens barrel along the direction of light propagation; both units are in mm. Therefore, based on each circumferential value and the calculated height value, the position of the cam groove on the zoom lens barrel can be determined. Figure 7This is a schematic diagram of a zoom lens barrel with one cam groove, the principle of which is the same as that with two cam grooves.

[0087] The zoom principle of an optical system determines the motion law of each moving lens group at different magnifications: First, the spatial position parameters of the zoom lens group and the compensation lens group along the optical axis are obtained through optical theory calculations; then, these position parameters need to be converted into the cam groove profile curve on the zoom lens barrel, that is, the cam curve. Its essence is to establish the correspondence between the "circumferential rotation of the lens barrel" and the "axial displacement of the lens group", so as to ensure that when the zoom lens barrel rotates, the cam groove can cooperate with the pulley screw to drive the displacement of the lens group to keep synchronized with the zoom fitting curve of the optical design.

[0088] The specific process involves mapping the spatial coordinates of each moving lens group to a cam curve on the zoom lens barrel by fitting a smooth mechanical curve function. In this way, when the zoom lens barrel rotates, it can drive each moving lens group through the cam curve to complete the displacement strictly according to the motion law of the optical design.

[0089] The solution proposed in this application integrates a continuous zoom optical system inside the main tube of a stereomicroscope and introduces a precision mechanical transmission system to achieve automated and precise axial movement of the compensation lens group and the zoom lens group. Since the movement of the lens group is completed automatically by the machine, the risk of contamination and inaccurate positioning that may be caused by manual operation is avoided.

[0090] Furthermore, by optimizing the curve algorithm, the control precision of the moving lens group can be improved to the micrometer level. In a specific embodiment, the error between the theoretical value calculated based on the above formulas (1) and (2) and the value in actual application is as follows: Figure 6 As shown. Among them, Figure 6 In the equations 'a' and 'b', respectively, are the error curves corresponding to formulas (2) and (1), with both the horizontal and vertical axes in mm. The horizontal axis represents the circumferential position of the stereomicroscope's zoom tube, with its maximum value being the circumference of the tube; the vertical axis represents the control error. Figure 6 It can be seen that the error in practical applications can be controlled within... Within micrometers, this indicates that the system has extremely high control precision.

[0091] Furthermore, the cam groove includes a first cam groove based on the first zoom fitting curve, the opening groove includes a first opening groove corresponding to the first cam groove, and the transmission system includes a first sliding screw; the sliding end of the first sliding screw is installed in the first cam groove, and the fixed end of the first sliding screw is fixedly connected to the compensation lens group through the first opening groove; similarly, the cam groove includes a second cam groove based on the second zoom fitting curve, the opening groove includes a second opening groove, the transmission system includes a second sliding screw, the sliding end of the second sliding screw is installed in the second cam groove, and the fixed end of the second sliding screw is fixedly connected to the zoom lens group.

[0092] The first and second cam grooves are machined on the outer wall of the zoom lens barrel according to the first and second cam curves, respectively. The first and second opening grooves are opening grooves corresponding to the first and second cam grooves, respectively, for the first and second sliding screws to pass through the main lens barrel. The transmission system is responsible for converting external operations into axial movement of the lens group. In addition to the sliding screw, the transmission system may also include gears, racks, worm gears, linkage mechanisms, or stepper motors. The sliding end is the part where the sliding screw contacts the cam groove and moves relative to it. To reduce friction and wear, the sliding end can be designed with a structure containing balls, rollers, or low-friction materials. The fixed end is the part where the sliding screw connects to the compensation lens group or zoom lens group. It can be designed as a threaded connection, pin connection, snap-fit ​​connection, or glued connection. The sliding end is installed in the cam groove, and the fixed end is connected to the lens group. When the cam groove moves relative to the sliding screw, the sliding end of the sliding screw is guided by the shape of the cam groove, thereby driving the lens group connected to the fixed end to move axially along the main optical axis.

[0093] By precisely designing the shape of the cam groove based on the first and second cam curves, and using the first and second sliding screws to directly connect the compensation lens group and the zoom lens group, high-precision, backlash-free transmission between the rotational motion of the zoom lens barrel and the axial displacement of the lens group is achieved, effectively avoiding dead points in the cam groove. This direct and precise transmission method avoids the possibility of accumulated errors in traditional multi-stage transmission mechanisms, significantly improving the positioning accuracy and motion stability of the compensation lens group and the zoom lens group during continuous zooming. Therefore, during continuous zooming operations in a stereo microscope, it ensures that the optical system is always in optimal optical condition, effectively suppressing aberrations, focus drift, or blurred field edges that may occur during zooming, greatly improving the microscope's imaging quality and user experience.

[0094] This application achieves optimizations in at least the following three aspects to improve the accuracy and stability of the mirror assembly movement, ensuring that the stereo microscope better meets the requirements for high-precision use: Combining optical design and ergonomic requirements, the lens group's running trajectory is designed as a continuous and smooth curve to match the operator's operating habits. This reduces operating errors while ensuring the smoothness and comfort of the zoom process. The rigidity of the cam-related structures is enhanced. These structures include, but are not limited to, cam barrels and cam grooves. By optimizing the component configuration and dimensional parameters, the rigidity of the cam is improved, ensuring that the cam is not easily deformed during long-term, high-frequency use, thereby maintaining the long-term consistency of imaging effects. Based on the continuous and smooth curve, the cam curve groove obtained by the cam curve design in this application breaks through the limitations of traditional mechanical design. It not only effectively avoids the "dead point" of cam operation, reduces the motion tilt rate, and improves the self-locking performance of the structure, but also improves the motion control accuracy of the moving lens group to the micrometer level by optimizing the curve algorithm.

[0095] Furthermore, the transmission system includes a zoom gear, which is fixedly connected to the zoom lens barrel; the zoom gear drives the zoom lens barrel to rotate based on the main optical axis, the first cam groove presses against the first sliding screw, and the first sliding screw drives the compensation lens group to move axially along the first open groove; similarly, the second sliding screw drives the zoom lens group to move axially along the second open groove.

[0096] The zoom gear is a toothed mechanical component whose main function is to mesh with other toothed components to transmit rotational motion and torque. This zoom gear can serve as the power input to drive the zoom lens barrel's rotation; for example, it can be a spur gear, helical gear, or bevel gear. By connecting to the output shaft of a motor, precise rotational control can be achieved.

[0097] Furthermore, the zoom gear is engraved with an optical magnification mark, which is obtained based on the first zoom fitting curve and the second zoom fitting curve, so as to identify the zoom state of the current system.

[0098] Because the first sliding screw fixes the compensating lens group and the second sliding screw fixes the zoom lens group, axial movement of the compensating lens group and the zoom lens group along the principal optical axis is achieved, thus enabling continuous zooming. The introduction of a zoom gear into the transmission system allows the rotation of the cam tube to be driven by automated equipment such as a motor, eliminating the need for manual contact with the zoom mechanism by the operator. This significantly reduces the risk of contamination from manual operation during surgical microscope use, especially in sterile surgical environments. This mechanical transmission method ensures the precision and synchronization of lens group movement, making the entire zooming process smooth and controllable. Furthermore, the fixed connection between the zoom gear and the zoom tube, as well as the precise control of the sliding screw by the cam groove, ensures that the compensating lens group and the zoom lens group can move axially strictly according to the preset zoom fitting curve, thereby maintaining excellent optical performance and imaging quality throughout the entire zoom range.

[0099] Although a transmission system was proposed to drive the movement of the compensation lens group and the zoom lens group, in its implementation, the gap between the transmission screw and the cam groove may cause inaccurate movement and errors, affecting the stability and accuracy of the microscope zoom process.

[0100] Furthermore, a positioning component is provided inside the main lens barrel. The positioning component is connected to the sliding end of the first sliding screw and the sliding end of the second sliding screw, and is used to eliminate the reverse clearance between the first sliding screw, the second sliding screw and the cam groove when the zoom lens barrel changes the rotation direction.

[0101] A positioning assembly is a mechanism used to eliminate backlash or clearance in a mechanical transmission system. Its function is to apply a continuous preload or constraint force to moving parts to ensure that the parts always maintain close contact. Backlash mainly refers to the tiny gap that appears between the pulley screw and the mating surfaces of the cam groove when the zoom lens barrel changes its rotation direction. That is, in the initial stage of the cam lens barrel's rotation, the pulley screw is not immediately moved; instead, this gap is eliminated first, creating a play. Only after the mating surfaces are fully engaged will the compensation / zoom assembly be driven to move along the optical axis.

[0102] Specifically, the positioning assembly can consist of two independent spring plungers, each mounted inside the main lens barrel and corresponding to a sliding screw. For example, one spring plunger can be mounted on the inner wall of the main lens barrel, with its spring-loaded tip facing the sliding end of the first sliding screw, applying a constant lateral force to press it firmly against one side wall of the first cam groove. Similarly, the other spring plunger acts on the sliding end of the second sliding screw and the second cam groove in a similar manner. The spring forces of these spring plungers are precisely designed to eliminate transmission backlash without creating excessive resistance to the normal movement of the sliding screw. In this way, regardless of the rotation of the zoom lens barrel, there is no play between the pulley screw and the cam groove, ensuring that the movement of the lens group is completely synchronized with the rotation of the cam lens barrel, thereby ensuring accurate axial movement of the compensation lens group and the zoom lens group.

[0103] Of course, the positioning components can also take various forms to eliminate minute gaps or looseness between components in the drivetrain. For example, it could be a spring-loaded plunger mechanism that applies constant pressure to the sliding screw through the elastic deformation of the spring; or it could be an adjustable eccentric sleeve or wedge mechanism that precisely compensates for and eliminates gaps by adjusting its position. By eliminating these gaps, the immediacy and accuracy of motion transmission can be ensured, avoiding motion lag, jitter, or positional deviation caused by gaps, thereby significantly improving the smoothness and positioning accuracy of the zoom process.

[0104] By setting a positioning component inside the main tube to actively eliminate backlash, the compensation lens group and the zoom lens group can move smoothly, accurately and stably along the main optical axis, which greatly improves the accuracy and reliability of the continuous zoom process. It can also further avoid problems such as image jitter, focus drift or zoom discontinuity caused by mechanical backlash, thus significantly improving the imaging quality and operating experience of the microscope at different magnifications.

[0105] In a specific embodiment, such as Figure 8 As shown, the main tube of this stereomicroscope is a ZOOM tube 8. The incident end of the ZOOM tube 8 uses a microscope interface, such as a Zeiss universal interface, and is fixed by a knurled set screw 7. The incident end and the exit port of the light emission have the same diameter. The ZOOM tube 8 is a straight tube with a smooth inner wall and minimal surface runout. It is also machined with an opening groove and a positioning surface that meet parallelism requirements. The opening groove and positioning surface are used to ensure the coaxiality of each lens group during assembly to avoid aberrations and to provide precise guidance for moving lens groups to prevent them from deviating from the principal optical axis during movement.

[0106] The microscope interface provides a stable, coaxial, and quick-connect connection to the main microscope tube and other optical modules. The microscope tube connected to this interface is a high-precision, smooth-walled straight tube with machined openings and positioning surfaces requiring strict parallelism. This design not only ensures coaxiality of the lens groups during assembly to suppress aberrations, but also provides precise guidance for moving lens groups, preventing them from deviating from the principal optical axis during zooming, thus guaranteeing stable optical performance and image quality throughout the entire zoom range.

[0107] Along the direction of light incident to light exit, the opening on the inner side of the Zeiss interface of the ZOOM lens barrel 8 is secured with a high-precision coaxial thread to the upper fixing assembly 1, which houses the upper fixing lens assembly. It is fixed with a pressure ring; the compensation group 2 is coaxially nested below the upper fixing group 1, and has a built-in compensation lens group. It is fixed with adhesive; the intermediate fixing group 3 is coaxially nested below the compensation group 2, and has a built-in intermediate fixing lens group. It is fixed with adhesive; the electrically adjustable aperture 5 is coaxially fixed below the middle fixed group 3, and the zoom group 4 is coaxially nested below the electrically adjustable aperture 5, with a built-in zoom lens group. It is fixed with adhesive; the exit end opening direction is fixed with a high-precision coaxial thread for the lower fixing group 6, and the lower fixing group 6 is coaxially nested with the lower fixing lens group. The pressure ring is used; the pressure ring fixation facilitates disassembly and subsequent calibration and maintenance, while the glue fixation takes into account both fixation strength and stress-free assembly, ensuring stability.

[0108] Using a cam-type lens barrel as the zoom lens barrel and a spring as the positioning component, the cam-type lens barrel 13 is nested in the outer wall of the ZOOM lens barrel 8. One end of the cam-type lens barrel 13 has a cam pressure ring 9, which keeps it aligned with the end face of the exit end of the ZOOM lens barrel 8 through the cam pressure ring 9, ensuring that the cam-type lens barrel is coaxial with the main optical axis.

[0109] Two through-type cam grooves are opened on the wall of the cam lens barrel, corresponding to the pulley screws of the compensation group and the zoom group respectively; the fixed end of the pulley screw 12 is fixed to the movable lens group, the pulley end is located in the cam groove and is pulled by the spring 10, so that the pulley end is always in close contact with the inner wall of the cam groove, eliminating the back gap and avoiding jamming or trajectory deviation during zooming; the zoom gear 11 is coaxially fixed to the cam lens barrel 13 by the set screw, and the external driving force drives the cam lens barrel to rotate through gear meshing.

[0110] In addition, the moving contact parts of components such as the pressure ring, such as the inner and outer walls that contact the inner wall of the lens group / lens barrel, must be smooth with a surface roughness of ≤0.8μm to reduce frictional resistance and wear during movement, thereby extending service life while ensuring accuracy; while the non-contact parts are machined with matte threads and treated with sandblasting and black anodizing to significantly reduce the reflection and diffuse reflection of stray light and reduce its interference with imaging quality.

[0111] This stereomicroscope's continuous zoom lens assembly uses the ZOOM 8 lens barrel as its core support base and integrates a continuous zoom optical system. - The lens group, electrically adjustable aperture, and mechanical zoom linkage mechanism are modularly assembled to achieve precise imaging, continuous zoom, and adjustable parameters, adapting to the binocular stereoscopic observation needs of stereo microscopes.

[0112] In highly dynamic and precise minimally invasive surgical environments, although existing technologies offer electrically adjustable diaphragms to dynamically adjust depth of field and light transmission, surgeons still face a cognitive burden of continuously optimizing focal plane and depth of field settings during the procedure. For example, when performing multi-layered tissue dissections, handling pulsating blood vessels, or operating on irregular lesion margins, the depth information of the surgical field changes rapidly. Surgeons need to constantly adjust the focus and diaphragm manually or via foot pedals to ensure that critical areas are always in optimal focus and within the appropriate depth of field.

[0113] This frequent, real-time adjustment of optical parameters requires surgeons to allocate extra attention to the precise control of the microscope in addition to their highly focused surgical procedures. This not only increases the surgeon's mental fatigue and may slow down the surgical process, but also distracts the surgeon from the core surgical task at critical moments, potentially increasing surgical risks or affecting operational accuracy.

[0114] Therefore, this stereomicroscope can also integrate an electric focusing mechanism and a control system with built-in image processing algorithms to achieve intelligent and automated management of the focus plane and depth of field.

[0115] It should be noted that the collection, gathering, updating, analysis, processing, use, transmission, and storage of user personal information involved in the technical solutions provided in the embodiments of the present invention all comply with the provisions of relevant laws and regulations, are used for legitimate purposes, and do not violate public order and good morals. Necessary measures are taken to prevent unauthorized access to user personal information data and to safeguard user personal information security, network security, and national security.

[0116] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A continuous zoom optical system for a stereo microscope, characterized in that, The system includes: an optical lens unit and a variable aperture; The optical lens unit includes an upper fixed lens group, a compensation lens group, a middle fixed lens group, a zoom lens group, and a lower fixed lens group arranged sequentially along the main optical axis; the variable aperture is disposed between the middle fixed lens group and the zoom lens group along the main optical axis. The upper fixed lens group, the compensation lens group, the zoom lens group, and the lower fixed lens group are all configured as dual-lens combinations, wherein the focal lengths of the upper fixed lens group and the zoom lens group are negative, and the focal lengths of the compensation lens group and the lower fixed lens group are positive; the middle fixed lens group is configured as a biconcave single lens. The compensation lens group and the zoom lens group move along the main optical axis based on the first zoom fitting curve and the second zoom fitting curve, respectively, to achieve continuous zoom.

2. The system as described in claim 1, characterized in that, Each of the said dual-lens assemblies is formed by cementing two sub-lenses together; the ratio of the focal length of each dual-lens assembly to its individual sub-lenses has a different preset range.

3. The system as described in claim 2, characterized in that, The upper fixed lens group includes a negative meniscus cemented lens, which is formed by cementing a biconcave lens and a biconvex lens; the compensation lens group includes a biconvex cemented lens, which is formed by cementing a negative meniscus lens and a biconvex lens; the zoom lens group includes a biconcave cemented lens, which is formed by cementing a biconcave lens and a positive meniscus lens; the lower fixed lens group includes a biconvex cemented lens, which is formed by cementing a biconvex lens and a positive meniscus lens.

4. The system as described in claim 3, characterized in that, The focal length ranges of the upper fixed lens group, the compensation lens group, the middle fixed lens group, the zoom lens group, and the lower fixed lens group are respectively... .

5. The system as described in claim 2, characterized in that, The preset ratio ranges for the focal length ratios of the upper fixed lens group, the lower fixed lens group, and their respective sub-lenses are as follows: The preset ratio ranges for the ratio of the focal length of the compensation lens group to that of its individual sub-lenses are respectively... The preset ratio range of the ratio of the focal length of the zoom lens group to that of its individual sub-lenses are respectively... .

6. The system as described in claim 1, characterized in that, The total optical length of the system is less than or equal to 100 mm; the total optical length refers to the axial distance measured along the principal optical axis from the incident surface of the upper fixed lens group near the light incident side to the exit surface of the lower fixed lens group near the light exit side.

7. A stereomicroscope for use in the system as described in claims 1-6, characterized in that, The microscope includes: a main microscope tube, a continuous zoom optical system, a zoom microscope tube, and a transmission system; The main lens barrel includes two independent optical paths symmetrically arranged based on the central axis of the main lens barrel; In any optical path, the continuous zoom optical system is disposed inside the main lens barrel, the transmission system is disposed on the zoom lens barrel, and the zoom lens barrel is nested on the outer wall of the main lens barrel based on the main optical axis; The outer wall of the zoom lens barrel has a cam groove based on the first cam curve and the second cam curve. The outer wall of the main lens barrel has an opening groove corresponding to the cam groove through it parallel to the main optical axis. The transmission system is connected to the compensation lens group and the zoom lens group in sequence through the opening groove and the cam groove, so as to drive the compensation lens group and the zoom lens group to move along the main optical axis. The first zoom fitting curve is used to obtain the first cam curve by fitting a smooth mechanical curve function; the second zoom fitting curve is used to obtain the second cam curve by fitting a smooth mechanical curve function.

8. The microscope as described in claim 7, characterized in that, The cam groove includes a first cam groove formed based on the first cam curve, and the opening groove includes a first opening groove formed corresponding to the first cam groove. The transmission system includes a first sliding screw. The sliding end of the first sliding screw is installed in the first cam groove, and the fixed end of the first sliding screw is fixedly connected to the compensation lens group through the first opening groove. Similarly, the cam groove includes a second cam groove opened based on the second cam curve, the opening groove includes a second opening groove, the transmission system includes a second sliding screw, the sliding end of the second sliding screw is installed in the second cam groove, and the fixed end of the second sliding screw is fixedly connected to the zoom lens group.

9. The microscope as described in claim 8, characterized in that, The transmission system includes a zoom gear, which is fixedly connected to the zoom lens barrel. The zoom gear drives the zoom lens barrel to rotate based on the main optical axis. The first cam groove presses against the first sliding screw, and the first sliding screw drives the compensation lens group to move axially along the first opening groove. Similarly, the second sliding screw drives the zoom lens group to move axially along the second opening groove.

10. The microscope as claimed in claim 8, characterized in that, A positioning component is provided inside the main lens barrel. The positioning component is connected to the sliding end of the first sliding screw and the sliding end of the second sliding screw, and is used to eliminate the reverse clearance between the first sliding screw, the second sliding screw and the cam groove when the zoom lens barrel changes the rotation direction.

Images