Liquid zoom lens and robot

Abstract

The application discloses a liquid zoom lens and a robot, and relates to the field of lenses. The liquid zoom lens comprises a first lens, a second lens, a third lens, a fourth lens, a diaphragm, a liquid lens, a fifth lens, a sixth lens and a seventh lens arranged in sequence along an optical axis from an object side to an image side. The optical power of the first lens to the seventh lens is negative, negative, positive, positive, negative, positive and positive in sequence, and the optical power of the liquid lens is positive or negative. The technical scheme has the advantages that the lens can be focused at different distances, the focusing distance is shortened, the near distance focusing requirement is met, the lens can be applied to more application scenarios, the number of lenses is small, the lens cost and weight are reduced, the number of plastic aspheric lenses is reduced, the system reliability is improved, and the performance degradation under harsh working conditions is reduced.

Description

Technical Field

[0001] This application relates to the field of lens technology, and more particularly to a liquid zoom lens and a robot. Background Technology

[0002] With the rapid development of robotics technology, the visual perception system, as the core module for robots to perceive their environment, undertakes key tasks such as target recognition, spatial localization, and object grasping. When robots perform delicate operations such as grasping and assembly, the lens needs to maintain clear imaging at extremely close distances, a requirement that poses a severe challenge to traditional optical lenses.

[0003] Currently, automotive lenses have become the reference prototype for most robot vision solutions due to their advantages such as compact structure and moderate cost. However, existing automotive lenses have the following inherent defects: (1) fixed depth of field, which cannot meet the requirements of close-range focusing; (2) in order to reduce cost and weight, plastic aspherical lenses are often used to replace some glass components, resulting in performance degradation and limited service life under harsh working conditions such as high temperature and high humidity. Summary of the Invention

[0004] This application provides a liquid zoom lens and a robot to solve the above-mentioned technical problems.

[0005] According to one aspect of this application, a liquid zoom lens is provided, comprising: a first lens, a second lens, a third lens, a fourth lens, an aperture stop, a liquid lens, a fifth lens, a sixth lens, and a seventh lens arranged sequentially along the optical axis from the object side to the image side; The optical power of the first to seventh lenses is negative, negative, positive, positive, negative, positive, positive, and positive, respectively, while the optical power of the liquid lens is either positive or negative.

[0006] Optionally, all seven lenses are glass spherical lenses.

[0007] Optional, 5cm≤MOD≤200cm; MOD stands for the focusing distance of a liquid zoom lens.

[0008] Optionally, when MOD=5cm, the optical power of the liquid lens is positive; When MOD=200cm, the optical power of the liquid lens is negative.

[0009] Optionally, -4.27 ≤ φ(1) / φ(2) ≤ -4.13; Wherein, φ(1) represents the optical power of the liquid lens when MOD=5cm; φ(2) represents the optical power of the liquid lens when MOD=200cm.

[0010] Optionally, -0.195 ≤ φ1 ≤ -0.185; -0.216≤φ2≤-0.205; 0.116≤φ3≤0.123; 0.096≤φ4≤0.125; -0.167≤φ5≤-0.109; 0.377≤φ6≤0.438; 0.063≤φ7≤0.077; Wherein, φ1 to φ7 represent the optical power of the first lens to the seventh lens, respectively.

[0011] Optionally, 2.29mm ≤ f ≤ 2.34mm; Where f represents the focal length of the liquid zoom lens.

[0012] Optional, TTL≤25mm; TTL indicates the total length of the liquid zoom lens.

[0013] Optional, TTL / H≤3.644; Where H represents the image height of the liquid zoom lens.

[0014] According to another aspect of this application, a robot is provided, the robot including a visual perception system, the visual perception system including the liquid zoom lens provided in any embodiment of this application.

[0015] The technical solution of this application, by setting a liquid lens between the fourth and fifth lenses, enables the lens to focus at different distances, which helps to shorten the focusing distance, meet the needs of close-range focusing, and is applicable to more application scenarios. In addition, the liquid fixed-focus lens includes seven conventional lenses and one liquid lens. The number of lenses is small, which helps to reduce lens cost and weight, reduces the use of plastic aspherical lenses, helps to increase system reliability, and reduces performance degradation under harsh conditions.

[0016] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1This is a schematic diagram of the structure of a liquid zoom lens provided in Embodiment 1 of this application; Figure 2 This is a schematic diagram of the structure of a liquid lens; Figure 3 A relative illumination diagram of a liquid zoom lens provided in Embodiment 1 of this application when the focusing distance is 5cm; Figure 4 Field curvature distortion diagram of the liquid zoom lens provided in Embodiment 1 of this application when the focusing distance is 5cm; Figure 5 The MTF diagram of the liquid zoom lens provided in Embodiment 1 of this application when the focusing distance is 5cm; Figure 6 MTF chart of the liquid zoom lens provided in Embodiment 1 of this application at a focusing distance of 200cm; Figure 7 This is a schematic diagram of the structure of a liquid zoom lens provided in Embodiment 2 of this application; Figure 8 A relative illumination diagram of a liquid zoom lens provided in Embodiment 2 of this application when the focusing distance is 5cm; Figure 9 The field curvature distortion diagram of the liquid zoom lens provided in Embodiment 2 of this application when the focusing distance is 5cm; Figure 10 The MTF diagram of the liquid zoom lens provided in Embodiment 2 of this application when the focusing distance is 5cm; Figure 11 The MTF diagram of the liquid zoom lens provided in Embodiment 2 of this application when the focusing distance is 200cm; Figure 12 This is a schematic diagram of the structure of a liquid zoom lens provided in Embodiment 3 of this application; Figure 13 A relative illumination diagram of a liquid zoom lens provided in Embodiment 3 of this application when the focusing distance is 5cm; Figure 14 The field curvature distortion diagram of the liquid zoom lens provided in Embodiment 3 of this application when the focusing distance is 5cm; Figure 15 The MTF diagram of the liquid zoom lens provided in Embodiment 3 of this application when the focusing distance is 5cm; Figure 16 MTF chart of the liquid zoom lens provided in Embodiment 3 of this application at a focusing distance of 200cm; Figure 17 This is a schematic diagram of the structure of a robot provided in Embodiment 4 of this application. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present application.

[0020] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0021] It should be noted that the implementation methods provided in this application can be combined with each other without contradiction.

[0022] Implementation 1 Figure 1 This is a schematic diagram of the structure of a liquid zoom lens provided in Embodiment 1 of this application, with reference to... Figure 1 The liquid zoom lens 001 includes: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, an aperture stop STO, a liquid lens L0, a fifth lens L5, a sixth lens L6, and a seventh lens L7 arranged sequentially along the optical axis from the object side to the image side; wherein, the optical power of the first lens L1 to the seventh lens L7 is negative, negative, positive, positive, negative, positive, positive, and positive, respectively, and the optical power of the liquid lens L0 is positive or negative.

[0023] Optical power is equal to the difference between the convergence of the image-side beam and the convergence of the object-side beam; it characterizes the ability of an optical system to deflect light. The larger the absolute value of the optical power, the stronger its ability to bend light; the smaller the absolute value, the weaker its ability to bend light. When the optical power is positive, the refraction of light is converging; when the optical power is negative, the refraction of light is diverging. Optical power can be used to characterize a single refractive surface of a lens (i.e., one surface of the lens), a single lens, or a system of multiple lenses (i.e., a lens group).

[0024] Specifically, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the aperture stop STO, the liquid lens L0, the fifth lens L5, the sixth lens L6, and the seventh lens L7 can be arranged in one lens barrel. Figure 1 (Not shown in the image). The liquid lens L0 is a continuously adjustable optical element that uses a transparent optical liquid as its core light-transmitting medium. It operates without moving glass lenses and controls the curvature of the liquid surface via electrical / pressure control. During continuous focusing, the position of the liquid lens L0 remains unchanged; focusing is achieved solely through the liquid lens L0. The surface curvature of the liquid lens L0 can be continuously varied, resulting in high image quality. By changing the surface curvature of the liquid lens L0, the liquid zoom lens 001 can be focused at any time.

[0025] It is understandable that during the focusing process by changing the surface curvature of the liquid lens L0, the surface shape of the liquid lens L0 can change, and the liquid lens L0 can have different optical powers.

[0026] The aperture stop STO can adjust the propagation direction of the light beam, which helps to improve image quality. The first lens L1 and the second lens L2 have negative optical power, which ensures that the light has a larger aperture before entering the aperture stop. The aperture stop STO is placed on the side of the fourth lens L4 with positive optical power closer to the image plane, and the liquid lens L0 is placed on the side of the aperture stop STO closer to the image plane, which enables the aberration of the liquid zoom lens 001 to be controlled.

[0027] For example, continue to refer to Figure 1 Along the direction from the object plane to the image plane, a planar glass lens CG is also provided. The planar glass lens CG is located on one side of the image surface of the seventh lens L7. The planar glass lens CG can protect the photosensitive chip in the imaging sensor. The photosensitive chip is used to convert the light signal collected by the zoom lens into an electrical signal, thereby ensuring the imaging effect of the zoom lens.

[0028] In some embodiments, the object-side surface of the first lens L1 is convex, and the image-side surface is concave; the object-side surface of the second lens L2 is concave, and the image-side surface is concave; the object-side surface of the third lens L3 is convex, and the image-side surface is convex; the object-side surface of the fourth lens L4 is convex, and the image-side surface is concave; the object-side surface of the fifth lens L5 is convex, and the image-side surface is concave; the object-side surface of the sixth lens L6 is convex, and the image-side surface is convex; the object-side surface of the seventh lens L7 is convex, and the image-side surface is convex; the fifth lens L5 and the sixth lens L6 are cemented together. This arrangement allows light from the object side to pass smoothly through the lenses in the liquid zoom lens after entering, thereby effectively reducing optical distortion and improving image quality.

[0029] It should be noted that, Figure 1 The structural diagrams in the following embodiments only exemplarily show the structure of the liquid zoom lens 001, but are not limited thereto. In other optional embodiments, the liquid zoom lens 001 may also have other structures. The embodiments of this application do not limit the spherical, aspherical, or surface shape of the zoom lens.

[0030] The liquid fixed-focus lens provided in this application embodiment, by setting a liquid lens between the fourth and fifth lenses, can achieve focusing at different distances, which is beneficial to shorten the focusing distance, meet the needs of close-range focusing, and can be applied to more application scenarios. In addition, the liquid fixed-focus lens includes seven conventional lenses and one liquid lens. The number of lenses is small, which helps to reduce lens cost and weight, reduce plastic aspherical lenses, help increase system reliability, and reduce performance degradation under harsh conditions.

[0031] In an optional embodiment, the first lens L1 to the seventh lens L7 are all glass spherical lenses. By replacing plastic lenses with all glass lenses, the environmental stability of the system can be significantly improved while maintaining a compact size (comparable to automotive lenses), avoiding performance degradation caused by plastic lenses under high temperature / high humidity conditions. Furthermore, the all-glass spherical lens group exhibits relatively low light loss in the edge field of view areas with large incident angles, maintaining high edge brightness with a relative illuminance exceeding 75%, effectively preventing vignetting.

[0032] In an optional embodiment, 5cm ≤ MOD ≤ 200cm; where MOD represents the focusing distance of the liquid zoom lens 001. Specifically, the liquid lens L0 enables the lens to focus at different distances. Combined with the short focal length characteristic of the wide-angle lens, the closest focusing distance can be shortened from approximately 10cm to 30cm in existing automotive lenses to 5cm. This effectively improves close-range focusing capability, achieving a closest focusing distance of 5cm. When applied to robots, this can fill the optical gap in close-range visual perception for robots.

[0033] In one embodiment, the optical power of the liquid lens L0 is positive when MOD = 5cm; and negative when MOD = 200cm. Specifically, when the optical power of the liquid lens L0 is positive, it has a converging effect on light, which can shorten the equivalent focal length and the focusing distance MOD; when the optical power of the liquid lens L0 is negative, it has a diverging effect on light, which can increase the equivalent focal length and the focusing distance MOD.

[0034] In another embodiment, -4.27 ≤ φ(1) / φ(2) ≤ -4.13; where φ(1) represents the optical power of the liquid lens L0 when MOD = 5cm; and φ(2) represents the optical power L0 of the liquid lens L0 when MOD = 200cm. This is beneficial for shortening the focusing stroke, reducing aberrations, increasing the focusing range, and meeting the needs of use under more conditions.

[0035] In an optional embodiment, -0.195≤φ1≤-0.185; -0.216≤φ2≤-0.205; 0.116≤φ3≤0.123; 0.096≤φ4≤0.125; -0.167≤φ5≤-0.109; 0.377≤φ6≤0.438; 0.063≤φ7≤0.077; where φ1 to φ7 represent the optical power of the first lens L1 to the seventh lens L7, respectively. This allows for effective aberration correction, ensuring high resolution throughout the focusing process to meet usage requirements in various situations.

[0036] In an optional embodiment, 2.29mm ≤ f ≤ 2.34mm; where f represents the focal length of the liquid zoom lens 001.

[0037] Focal length characterizes the ability to deflect light; a larger focal length results in a weaker ability to deflect light, while a smaller focal length results in a stronger ability. When the focal length is positive, the refraction of light is converging; when the focal length is negative, the refraction of light is diverging. By controlling the focal length of the liquid zoom lens 001 and combining it with the target surface parameters, an ultra-wide-angle lens can be achieved. In some embodiments, the liquid zoom lens 001 provided in this application can be adapted to mainstream automotive camera modules.

[0038] In an optional embodiment, TTL ≤ 25mm; where TTL represents the total length of the liquid zoom lens 001. Through optical design optimization and the high integration of the liquid lens module, a compact structural design can be achieved, keeping the total length of the liquid zoom lens 001 within 25mm, comparable to automotive lenses. This facilitates adaptation to the mounting space of humanoid robot hands / heads, allowing for direct embedding into the robot's hand or head structure without significant modifications to the robot's overall design. Based on the above embodiment, TTL / H ≤ 3.644; where H represents the image height of the liquid zoom lens 001. This helps to limit the overall volume of the liquid zoom lens 001, giving it the advantage of a small size.

[0039] Table 1 shows the design parameters of the liquid zoom lens 001 provided in Embodiment 1 of this application, including lens surface type, radius of curvature, thickness, and material.

[0040] Table 1 shows a parameter design for each lens in Example 1. In Table 1, the surface numbers are assigned according to the surface sequence of each lens. For example, surface number 1 represents the object side of the first lens L1, surface number 2 represents the image side of the first lens L1, and so on. "STO" represents the aperture stop of the zoom lens. The radius of curvature represents the curvature of the corresponding lens surface in mm. A positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "Infinity" indicates that the surface is flat and the radius of curvature is infinite. The thickness represents the axial distance between the current surface and the next surface in mm. The refractive index represents the ability of the material between the current surface and the next surface to deflect light. A blank space indicates that the current position is air and the refractive index is 1. The Abbe number represents the ability of the material between the current surface and the next surface to disperse light. A blank space indicates that the current position is air and the Abbe number is 1.

[0041] Among them, surfaces numbered 10-15 are liquid lenses. Figure 2 This is a schematic diagram of the structure of a liquid lens, for reference. Figure 2 Surface number 10 and surface number 11 are the object side and image side of the film protecting the liquid lens. The liquid between surface number 11 and surface number 12 is the liquid of the liquid lens. Surface number 13 is a virtual surface. Surface number 14 and surface number 15 are the object side and image side of another film protecting the liquid lens. Surface number 10 (1) and surface number 11 (1) represent surface number 10 and surface number 11 when the focusing distance of the liquid zoom lens 001 is 5cm. Surface number 10 (2) and surface number 11 (2) represent surface number 10 and surface number 11 when the focusing distance of the liquid zoom lens 001 is 200cm. When the focusing distance is different, the radius of curvature of the surface of surface number 10 and surface number 11 can be different, and the surface shape can also be different.

[0042] In one embodiment, a liquid zoom lens with a focal length of 2.34mm, an F-number of 3.32, a half-image height of 3.43mm, and a DFOV of 176° can be obtained, where DFOV is the diagonal field of view of the liquid zoom lens.

[0043] Figure 3 The relative illumination diagram of a liquid zoom lens with a focusing distance of 5cm provided in Embodiment 1 of this application is for reference. Figure 3The relative illuminance diagram reflects the uniformity of illumination across the entire image area of ​​a wide-angle lens, i.e., the brightness difference between the edges and the center. It is an important indicator for evaluating the image quality of a lens, especially crucial for wide-angle lenses. The liquid zoom lens 001 provided in Embodiment 1 of this application has a relative illuminance of over 0.7 within a field of view of 0-88°, indicating that the liquid zoom lens 001 exhibits excellent uniformity of illumination across the entire image area, strong adaptability to the field of view, and effective transmission of edge light.

[0044] Figure 4 The image shows the field curvature distortion of the liquid zoom lens provided in Embodiment 1 of this application at a focusing distance of 5cm. Figure 4 In the left-hand coordinate system, the horizontal coordinate represents the magnitude of the field curvature in mm; the vertical coordinate represents the normalized image height, which has no unit; where T represents the meridion and S represents the sagitta; Figure 4 It can be seen that when the focusing distance of the liquid zoom lens 001 provided in this embodiment is 5cm, the field curvature is effectively controlled, that is, during imaging, the difference between the image quality in the center and the image quality in the periphery is small. Figure 4 In the right-hand coordinate system, the horizontal coordinate represents the magnitude of distortion, expressed as a percentage; the vertical coordinate represents the normalized image height, which has no unit. Figure 4 As can be seen, the distortion of the liquid zoom lens 001 provided in this embodiment 1 at a focusing distance of 5cm is well corrected, and the imaging distortion is small.

[0045] Figure 5 The image shows the MTF (Mean Transformer Graph) of the liquid zoom lens provided in Embodiment 1 of this application at a focusing distance of 5cm. Figure 6 This is the MTF (Mean Transformer Frequency) graph of the liquid zoom lens provided in Embodiment 1 of this application at a focusing distance of 200cm. MTF is one of the most commonly used methods for evaluating lens resolution in modern optical design. In the graph, the horizontal axis represents spatial frequency, and the vertical axis represents contrast, ranging from 0 to 1.0. Different colored lines represent MTF curves under different fields of view. S and T correspond to the sagittal and meridional of each frequency. Figure 5 , Figure 6 It can be seen that the system aberrations are well corrected and the field curvature is small. At the same time, the astigmatism of the system is also well corrected, thus ensuring that the optical system can achieve the high-resolution imaging requirements.

[0046] Example 2 Figure 7 This is a schematic diagram of the structure of a liquid zoom lens provided in Embodiment 2 of this application. The similarities with the previous description will not be repeated, and only the differences will be explained.

[0047] Table 2 shows the design parameters of the liquid zoom lens provided in Embodiment 2 of this application, including lens surface type, radius of curvature, thickness, and material.

[0048] Table 2 shows a parameter design for each lens in Example 2. In Table 2, the surface numbers are assigned according to the surface sequence of each lens. For example, surface number 1 represents the object side of the first lens L1, surface number 2 represents the image side of the first lens L1, and so on. "STO" represents the aperture stop of the zoom lens. The radius of curvature represents the curvature of the corresponding lens surface in mm. A positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "Infinity" indicates that the surface is flat and the radius of curvature is infinite. The thickness represents the axial distance between the current surface and the next surface in mm. The refractive index represents the ability of the material between the current surface and the next surface to deflect light. A blank space indicates that the current position is air and the refractive index is 1. The Abbe number represents the ability of the material between the current surface and the next surface to disperse light. A blank space indicates that the current position is air and the Abbe number is 1.

[0049] Surface number 10 and surface number 11 are the object side and image side of the thin film protecting the liquid lens. The liquid between surface number 11 and surface number 12 is the liquid of the liquid lens. Surface number 13 is a virtual surface. Surface number 14 and surface number 15 are the object side and image side of another thin film protecting the liquid lens. Surface number 10 (1) and surface number 11 (1) represent surface number 10 and surface number 11 when the focusing distance of the liquid zoom lens 001 is 5cm. Surface number 10 (2) and surface number 11 (2) represent surface number 10 and surface number 11 when the focusing distance of the liquid zoom lens 001 is 200cm. When the focusing distance is different, the radius of curvature of the surface of surface number 10 and surface number 11 can be different, and the surface shape can also be different.

[0050] In implementation two, a liquid zoom lens with a focal length of 2.29mm, an F number of 3.26, a half-image height of 3.43mm, and a DFOV of 176° can be obtained, where DFOV is the diagonal field of view of the liquid zoom lens.

[0051] Figure 8 This is a relative illumination diagram of a liquid zoom lens provided in Embodiment 2 of this application at a focusing distance of 5cm, for reference. Figure 8 The relative illuminance diagram reflects the uniformity of illumination across the entire image area of ​​a wide-angle lens, i.e., the brightness difference between the edges and the center. It is an important indicator for evaluating the image quality of a lens, especially crucial for wide-angle lenses. The liquid zoom lens 001 provided in Embodiment 2 of this application has a relative illuminance of over 0.7 within a field of view of 0-88°, indicating that the liquid zoom lens 001 exhibits excellent uniformity of illumination across the entire image area, strong adaptability to the field of view, and effective transmission of edge light.

[0052] Figure 9This is a field curvature distortion diagram of the liquid zoom lens provided in Embodiment 2 of this application at a focusing distance of 5cm. Figure 9 In the left-hand coordinate system, the horizontal coordinate represents the magnitude of the field curvature in mm; the vertical coordinate represents the normalized image height, which has no unit; where T represents the meridion and S represents the sagitta; Figure 9 It can be seen that when the focusing distance of the liquid zoom lens 001 provided in this embodiment is 5cm, the field curvature is effectively controlled, that is, during imaging, the difference between the image quality in the center and the image quality in the periphery is small. Figure 9 In the right-hand coordinate system, the horizontal coordinate represents the magnitude of distortion, expressed as a percentage; the vertical coordinate represents the normalized image height, which has no unit. Figure 9 It can be seen that the distortion of the liquid zoom lens 001 provided in this embodiment 2 is well corrected when the focusing distance is 5cm, and the imaging distortion is small.

[0053] Figure 10 The MTF chart is shown for the liquid zoom lens provided in Embodiment 2 of this application when the focusing distance is 5cm. Figure 11 This is the MTF (Mean Transformer Frequency) graph of the liquid zoom lens provided in Embodiment 2 of this application at a focusing distance of 200cm. MTF is one of the most commonly used methods for evaluating lens resolution in modern optical design. In the graph, the horizontal axis represents spatial frequency, and the vertical axis represents contrast, ranging from 0 to 1.0. Different colored lines represent MTF curves under different fields of view. S and T correspond to the sagittal and meridional of each frequency. Figure 10 , Figure 11 It can be seen that the system aberrations are well corrected and the field curvature is small. At the same time, the astigmatism of the system is also well corrected, thus ensuring that the optical system can achieve the high-resolution imaging requirements.

[0054] Example 3 Figure 12 This is a schematic diagram of the structure of a liquid zoom lens provided in Embodiment 3 of this application. The similarities with the previous description will not be repeated, and only the differences will be explained.

[0055] Table 3 shows the design parameters of the liquid zoom lens 001 provided in Embodiment 3 of this application, including lens surface type, radius of curvature, thickness, and material.

[0056] Table 3 shows a parameter design for each lens in Example 3. In Table 3, the surface numbers are assigned according to the surface sequence of each lens. For example, surface number 1 represents the object side of the first lens L1, surface number 2 represents the image side of the first lens L1, and so on. "STO" represents the aperture stop of the zoom lens. The radius of curvature represents the curvature of the corresponding lens surface in mm. A positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "Infinity" indicates that the surface is flat and the radius of curvature is infinite. The thickness represents the central axial distance between the current surface and the next surface in mm. The refractive index represents the ability of the material between the current surface and the next surface to deflect light. A blank space indicates that the current position is air and the refractive index is 1. The Abbe number represents the ability of the material between the current surface and the next surface to disperse light. A blank space indicates that the current position is air and the Abbe number is 1.

[0057] Surface number 10 and surface number 11 are the object side and image side of the thin film protecting the liquid lens. The liquid between surface number 11 and surface number 12 is the liquid of the liquid lens. Surface number 13 is a virtual surface. Surface number 14 and surface number 15 are the object side and image side of another thin film protecting the liquid lens. Surface number 10 (1) and surface number 11 (1) represent surface number 10 and surface number 11 when the focusing distance of the liquid zoom lens 001 is 5cm. Surface number 10 (2) and surface number 11 (2) represent surface number 10 and surface number 11 when the focusing distance of the liquid zoom lens 001 is 200cm. When the focusing distance is different, the radius of curvature of the surface of surface number 10 and surface number 11 can be different, and the surface shape can also be different.

[0058] In implementation three, a liquid zoom lens with a focal length of 2.30mm, an F-number of 3.25, a half-image height of 3.43mm, and a DFOV of 176° can be obtained, where DFOV is the diagonal field of view of the liquid zoom lens.

[0059] Figure 13 This is a relative illumination diagram of a liquid zoom lens provided in Embodiment 3 of this application at a focusing distance of 5cm, for reference. Figure 13 The relative illuminance diagram reflects the uniformity of illumination across the entire image area of ​​a wide-angle lens, i.e., the brightness difference between the edges and the center. It is an important indicator for evaluating the image quality of a lens, especially crucial for wide-angle lenses. The liquid zoom lens 001 provided in Embodiment 3 of this application has a relative illuminance of over 0.7 within a field of view of 0-88°, indicating that the liquid zoom lens 001 has excellent uniformity of illumination across the entire image area, strong adaptability to the field of view, and effective transmission of edge light.

[0060] Figure 14 This is a field curvature distortion diagram of the liquid zoom lens provided in Embodiment 3 of this application when the focusing distance is 5cm. Figure 14In the left-hand coordinate system, the horizontal coordinate represents the magnitude of the field curvature in mm; the vertical coordinate represents the normalized image height, which has no unit; where T represents the meridion and S represents the sagitta; Figure 14 It can be seen that when the focusing distance of the liquid zoom lens 001 provided in the three embodiments is 5cm, the field curvature is effectively controlled, that is, during imaging, the difference between the image quality in the center and the image quality in the periphery is small. Figure 14 In the right-hand coordinate system, the horizontal coordinate represents the magnitude of distortion, expressed as a percentage; the vertical coordinate represents the normalized image height, which has no unit. Figure 14 It can be seen that the distortion of the liquid zoom lens 001 provided in this embodiment 3 is well corrected when the focusing distance is 5cm, and the imaging distortion is small.

[0061] Figure 15 The MTF chart of the liquid zoom lens provided in Embodiment 3 of this application is shown when the focusing distance is 5cm. Figure 16 This is the MTF (Mean Transformer Frequency) graph of the liquid zoom lens provided in Embodiment 3 of this application at a focusing distance of 200cm. MTF is one of the most commonly used methods for evaluating lens resolution in modern optical design. In the graph, the horizontal axis represents spatial frequency, and the vertical axis represents contrast, ranging from 0 to 1.0. Different colored lines represent MTF curves under different fields of view. S and T correspond to the sagittal and meridional of each frequency. Figure 15 , Figure 16 It can be seen that the system aberrations are well corrected and the field curvature is small. At the same time, the astigmatism of the system is also well corrected, thus ensuring that the optical system can achieve the high-resolution imaging requirements.

[0062] Example 4 Figure 17 This is a schematic diagram of the structure of a robot provided in Embodiment 4 of this application, with reference to... Figure 17 The robot 003 includes a visual perception system 002, which includes the liquid zoom lens 001 provided in any embodiment of this application.

[0063] The robot 003 provided in this application embodiment includes, but is not limited to, humanoid robots, wheeled / tracked robots, fixed robotic arms, underwater / surface robots, snake-like robots, climbing robots, etc. When the robot provided in this application embodiment is a humanoid robot, the visual perception system 002 can be located at the head or hand of the humanoid robot.

[0064] Note that the above are merely preferred embodiments and the technical principles employed in this application. Those skilled in the art will understand that this application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of this application, the scope of which is determined by the scope of the appended claims.

Claims

1. A liquid zoom lens, characterized in that, include: The first lens, second lens, third lens, fourth lens, aperture, liquid lens, fifth lens, sixth lens, and seventh lens are arranged sequentially along the optical axis from the object side to the image side. The optical power of the first to seventh lenses is negative, negative, positive, positive, negative, positive, positive, and positive, respectively, and the optical power of the liquid lens is either positive or negative.

2. The liquid zoom lens according to claim 1, characterized in that, The first to the seventh lenses are all glass spherical lenses.

3. The liquid zoom lens according to claim 1, characterized in that, 5cm≤MOD≤200cm; MOD represents the focusing distance of the liquid zoom lens.

4. The liquid zoom lens according to claim 3, characterized in that, When MOD=5cm, the optical power of the liquid lens is positive; When MOD=200cm, the optical power of the liquid lens is negative.

5. The liquid zoom lens according to claim 3, characterized in that, -4.27≤φ(1) / φ(2)≤-4.13; Wherein, φ(1) represents the optical power of the liquid lens when MOD=5cm; φ(2) represents the optical power of the liquid lens when MOD=200cm.

6. The liquid zoom lens according to claim 1, characterized in that, -0.195≤φ1≤-0.185; -0.216≤φ2≤-0.205; 0.116≤φ3≤0.123; 0.096≤φ4≤0.125; -0.167≤φ5≤-0.109; 0.377≤φ6≤0.438; 0.063≤φ7≤0.077; Wherein, φ1 to φ7 represent the optical power of the first lens to the seventh lens, respectively.

7. The liquid zoom lens according to claim 1, characterized in that, 2.29mm≤f≤2.34mm; Where f represents the focal length of the liquid zoom lens.

8. The liquid zoom lens according to claim 1, characterized in that, TTL≤25mm; Wherein, TTL represents the total length of the liquid zoom lens.

9. The liquid zoom lens according to claim 8, characterized in that, TTL / H≤3.644; Wherein, H represents the image height of the liquid zoom lens.

10. A robot, characterized in that, The robot includes a visual perception system, which includes the liquid zoom lens according to any one of claims 1-9.

Images