A lens, a camera module and a terminal device

Abstract

The embodiment of the application discloses a lens, a camera module and a terminal device, in the embodiment of the application, the lens adds a liquid lens type focusing assembly on the basis of a lens assembly, and the focusing assembly can be located on the object side of the lens assembly. That is to say, external light can first enter the focusing assembly, the light refracted by the focusing assembly enters each lens of the lens assembly, and then is projected onto an image plane. The refractive index n1 of the first liquid layer and the refractive index n2 of the second liquid layer satisfy the following formula: n1 < n2; and the Abbe number of each layer of liquid is greater than or equal to 58, which is conducive to reducing the chromatic aberration introduced by the liquid lens focusing and obtaining better focusing performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical lenses, and in particular to a lens, a camera module, and a terminal device. BACKGROUND ART

[0002] In recent years, with the rapid development and widespread popularization of intelligent mobile terminals, users have increasingly higher requirements for the photographing performance and imaging quality of intelligent mobile terminals such as mobile phones in different scenarios. Conventional imaging modules require a motor to move the lens assembly to achieve focusing, which has a relatively complex structure, a focusing range limited by the load and travel of the motor, and a relatively low focusing speed.

[0003] How to ensure the imaging quality at different object distances while achieving fast focusing has become one of the problems to be solved in the industry at present. SUMMARY OF THE INVENTION

[0004] Embodiments of the present application provide a lens which has small aberration and a relatively large focusing range. Embodiments of the present application further provide a camera module and a terminal device comprising the above lens.

[0005] An embodiment of the present application provides a lens, comprising:

[0006] a lens assembly, wherein the lens assembly comprises at least three lenses;

[0007] a focusing assembly, wherein the focusing assembly comprises a flat substrate, at least three layers of liquid are sealed inside the flat substrate, the three layers of liquid are arranged along the direction from the object side to the image side, adjacent liquids have the same density and are immiscible with each other to form a curvature-adjustable interface, and in the direction from the object side to the image side, the curvature-adjustable interface comprises a first curvature-adjustable interface and a second curvature-adjustable interface; that is, the first curvature-adjustable interface and the second curvature-adjustable interface are sequentially arranged along the direction from the object side to the image side.

[0008] The curvature of the first curvature-adjustable interface and the curvature of the second curvature-adjustable interface can both be changed under the action of a voltage, so as to change the optical power of the focusing assembly, thereby realizing the autofocus function of the lens;

[0009] The liquids comprise a first liquid layer located on the object side of the first curvature-adjustable interface, and a second liquid layer located on the image side of the first curvature-adjustable interface, wherein the refractive index n1 of the first liquid layer and the refractive index n2 of the second liquid layer satisfy the following formula: n1<n2; and the Abbe number of each layer of liquid is ≥58.

[0010] In the embodiments of the present application, on the basis of the lens assembly, the camera lens is additionally provided with a focusing assembly in a liquid lens form, and the focusing assembly may be located on the object side of the lens assembly. That is, external light may first enter the focusing assembly, the light refracted by the focusing assembly then enters each lens of the lens assembly, and then is projected onto the image plane. The refractive index n1 of the first liquid layer and the refractive index n2 of the second liquid layer satisfy the following formula: n1<n2; the Abbe number of each liquid layer is ≥58, which is beneficial to reducing chromatic aberration introduced by focusing of the liquid lens, and obtaining better focusing performance.

[0011] In some optional embodiments, when the camera lens focuses on a macro distance, the effective focal length LF1 of the first curvature-adjustable interface and the effective focal length LF2 of the second curvature-adjustable interface satisfy the following formula: |LF1 / LF2|<2.1. In this way, the power distribution of the two curvature-adjustable interfaces can be effectively balanced, the field curvature introduced by the change of optical power is reduced, and the focusing performance is improved.

[0012] In some optional embodiments, the macro focusing distance d of the camera lens and the total effective focal length LF of the focusing assembly satisfy the following formula: 0.95<LF / d<1.05. This is beneficial to quickly evaluating the achievable focusing range of the focusing assembly, and better adapting to the focusing system.

[0013] In some optional embodiments, the total effective focal length f of the lens assembly and the total effective focal length LF of the focusing assembly when focusing at the macro distance satisfy the following formula: |f / LF|<0.1. In this way, the optical power of the lens assembly 2 and the focusing assembly 1 can be effectively balanced, the aberration introduced by the change of the optical power of the focusing assembly 1 can be corrected, and the imaging quality of the system can be improved.

[0014] In some optional embodiments, the lens assembly at least includes a first lens and a second lens, and the effective focal length f1 of the first lens and the effective focal length f2 of the second lens satisfy the following formula: |f1 / f2|<2. This is beneficial to reasonably distributing the optical power of the first lens and the second lens, making the light reasonably deflected at the first lens and the second lens, correcting system aberrations, and improving the imaging quality of the system.

[0015] In some optional embodiments, the lens assembly includes a first lens, and the distance TTL on the optical axis from the object side surface of the first lens to the image plane, the total effective focal length f of the lens assembly, and the aperture value FNO of the lens assembly satisfy the following formula: 2<(TTL / f)*FNO<4. This is beneficial to reasonably setting the length and the clear aperture of the lens assembly, and compressing the size of the lens assembly as much as possible while increasing the clear aperture.

[0016] In some optional embodiments, the lens assembly is configured to be a structure capable of imaging an object at an infinite object distance independently. This enables the focusing assembly to adapt to different lens assemblies without affecting the design of the lens assemblies.

[0017] In some optional implementations, when focusing on macro, the first curvature adjustable interface is either convex or concave, and the second curvature adjustable interface is either convex or concave. That is, the first curvature adjustable interface can bulge towards the first liquid layer to form a convex surface, or it can bulge towards the second liquid layer to form a concave surface. Similarly, when focusing on macro, the second curvature adjustable interface can also be either convex or concave; it can bulge towards the object side to form a convex surface, or it can bulge towards the image side to form a concave surface. The first and second curvature adjustable interfaces can form interfaces with different curvatures, meeting the needs of different macro focusing states, offering high flexibility and improving image quality.

[0018] In some alternative embodiments, the liquid further includes a third liquid layer located on the image side of the second liquid layer. The flat substrate has a sealed cavity, and the first, second, and third liquid layers are located inside the same sealed cavity. This results in a simpler focusing assembly structure, a smaller footprint, which is beneficial for lens miniaturization and makes the lens lighter.

[0019] In some alternative implementations, the refractive index n2 of the second liquid layer and the refractive index n3 of the third liquid layer satisfy the following formula: n2>n3.

[0020] In some alternative embodiments, along the object-to-image direction, the flat substrate includes a first and a second sealed cavity that are relatively isolated from each other, and the liquid further includes a third and a fourth liquid layer, with the first and second liquid layers located in the first sealed cavity and the third and fourth liquid layers located in the second sealed cavity. This facilitates the assembly of the liquid.

[0021] In some alternative embodiments, along the object-to-image direction, the flat substrate includes a first flat layer, a second flat layer, and a third flat layer. A first sealing cavity is formed between the first and second flat layers, and a second sealing cavity is formed between the second and third flat layers. In this embodiment, only three flat layers are needed to isolate the first and second sealing cavities along the optical axis. The number of flat substrate layers is relatively small, minimizing the impact on the focusing performance of the focusing assembly. Furthermore, the focusing assembly structure is relatively compact and occupies less space.

[0022] Alternatively, along the object-to-image direction, the flat substrate includes a first flat layer, a second flat layer, a third flat layer, and a fourth flat layer. A first sealing cavity is formed between the first and second flat layers, and a second sealing cavity is formed between the third and fourth flat layers. The second and third flat layers are bonded together. In this way, while achieving relative independence between the main bodies of the first and second sealing cavities, the flat substrate occupies a relatively small space, which is beneficial for miniaturizing the lens.

[0023] Alternatively, along the direction from the object side to the image side, the flat substrate comprises a first flat layer, a second flat layer, a third flat layer and a fourth flat layer, wherein the first sealed cavity is formed between the first flat layer and the second flat layer, the second sealed cavity is formed between the third flat layer and the fourth flat layer, and the second flat layer and the third flat layer have a predetermined spacing. The first sealed cavity and the second sealed cavity may be respectively formed by different flat plate structures, a single flat plate structure is relatively simple and easy to form, and the two flat plate structures are relatively independent and do not interfere with each other, so that the arrangement flexibility is relatively high.

[0024] In some optional embodiments, the fourth liquid layer is located on the image side of the third liquid layer, and the refractive index n3 of the third liquid layer and the refractive index n4 of the fourth liquid layer satisfy the following formula: n3<n4. In this embodiment, smaller optical aberration can be introduced, and better focusing performance can be obtained.

[0025] In some optional embodiments, the thickness of the flat substrate does not affect the focusing performance of the focusing assembly.

[0026] In some optional embodiments, the flat substrate comprises flat glass, flat plastic or flat ice. The flat glass may be optical grade glass with relatively high transparency. The flat plastic is low in price and light in weight.

[0027] An embodiment of the present application further provides a camera module, comprising the lens according to any one of the above embodiments.

[0028] An embodiment of the present application further provides a terminal device. The terminal device may specifically be a terminal device with an imaging function, such as a mobile phone, a camera, a smart watch, etc., which comprises a main body and the above-mentioned camera module.

[0029] Since the above lens has the above technical effects, the camera module and the terminal device having the lens should also have similar technical effects, and thus details are not described herein again. Brief Description of the Drawings

[0030] Figure 1 is a front view of a specific embodiment of the terminal device provided by the embodiment of the present application;

[0031] Figure 2 is Figure 1 a rear view of the above;

[0032] Figure 3 is a schematic structural diagram of a first embodiment of the lens provided by the embodiment of the present application;

[0033] Figure 4 is Figure 3 an MTF graph of the lens in the above when the focusing assembly focuses at 20cm;

[0034] Figure 5 for Figure 3 A schematic diagram of the lens assembly shown in the diagram, demonstrating its ability to image independently at a focusing distance of 20cm.

[0035] Figure 6 for Figure 5 The MTF curve of the lens assembly shown;

[0036] Figure 7 This is a schematic diagram of a second embodiment of the lens provided in this application.

[0037] Figure 8 for Figure 7 MTF curve of the medium lens at 30cm focusing distance using the focusing assembly;

[0038] Figure 9 for Figure 7 A schematic diagram of the lens assembly shown in the diagram, demonstrating its ability to image independently at a focusing distance of 30cm.

[0039] Figure 10 for Figure 9 The MTF curve of the lens assembly shown;

[0040] Figure 11 This is a schematic diagram of a third embodiment of the lens provided in this application.

[0041] Figure 12 for Figure 11 MTF curve of the medium lens at 50cm focusing with the focusing assembly;

[0042] Figure 13 for Figure 11 A schematic diagram of the lens assembly shown in the diagram, demonstrating its ability to image independently at a focusing distance of 50cm.

[0043] Figure 14 for Figure 13 The MTF curve of the lens assembly shown;

[0044] Figure 15 This is a schematic diagram of the fourth embodiment of the lens provided in this application.

[0045] Figure 16 for Figure 15 MTF curve of the medium lens at 20cm focusing distance using the focusing assembly;

[0046] Figure 17 for Figure 15 A schematic diagram of the lens assembly shown in the diagram, demonstrating its ability to image independently at a focusing distance of 20cm.

[0047] Figure 18 for Figure 17 The MTF curve of the lens assembly shown;

[0048] Figure 19 A schematic diagram illustrating the structure of a fifth embodiment of the lens provided in this application;

[0049] Figure 20 for Figure 19 MTF curve of the medium lens at 20cm focusing distance using the focusing assembly;

[0050] Figure 21 for Figure 19 A schematic diagram of the lens assembly shown in the diagram, demonstrating its ability to image independently at a focusing distance of 20cm.

[0051] Figure 22 for Figure 21 The MTF curve of the lens assembly shown.

[0052] Figures 1-22 The annotations in the accompanying drawings are explained as follows:

[0053] 100 Terminal equipment, 101 Housing, 102 Display screen, 103 Camera module, 104 Protective lens;

[0054] 1. Focusing assembly; 10. Flat substrate; 1-1 First flat layer; 1-2 Second flat layer; 1-3 Third flat layer, 1-4 Fourth flat layer; 11 First liquid layer; 12 Second liquid layer; 13 Third liquid layer; 14 Fourth liquid layer;

[0055] 2. Lens assembly; 20. Aperture; 21. First lens; 22. Second lens; 23. Third lens; 24. Fourth lens; 25. Fifth lens; 26. Filter; 27. Image plane; 28. Sixth lens; 29. ​​Seventh lens; 30. Prism; P1P2 imaging area Detailed Implementation

[0056] To enable those skilled in the art to better understand the technical solutions of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0057] For ease of understanding, some of the technical terms involved in the embodiments of this application will be explained and described below.

[0058] The optical axis is the direction in which light rays travel through an optical system, and is referenced to the principal ray at the center of the field of view. For symmetrical transmission systems, it generally coincides with the rotation center line of the optical system.

[0059] Focal length, also known as focal length, is a measure of the convergence or divergence of light in an optical system. It refers to the distance from the optical center of a lens to the focal point when a distant object is focused onto the focal plane. For fixed-focus lenses, the position of their optical center is fixed, therefore the focal length is fixed.

[0060] 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 rays. When the refractive index of air is approximately assumed to be 1, optical power is generally expressed as the reciprocal of the image-side focal length.

[0061] Using the lens as a boundary, the side where the subject is located is called the object side, and the surface of the lens closest to the object side can be called the object-side surface. Using the lens as a boundary, the side where the image of the subject is located is called the image side, and the surface of the lens closest to the image side can be called the image-side surface.

[0062] This application provides a terminal device, which may include a handheld device, an in-vehicle device, a wearable device, a computing device, or other processing devices connected to a wireless modem. It may also include cellular phones, smartphones, personal digital assistant (PDA) computers, tablet computers, laptop computers, cameras, video recorders, cameras, smartwatches, smart wristbands, in-vehicle computers, and other terminal devices with imaging capabilities. This application does not impose special limitations on the specific form of the aforementioned terminal device; for ease of understanding, the following description uses a mobile phone as an example.

[0063] Please refer to Figure 1 and Figure 2 , Figure 1 This is a front view of a specific embodiment of the terminal device provided in this application. Figure 2 for Figure 1 Rear view.

[0064] like Figure 1 As shown, the terminal device 100 may include a housing 101, a display screen 102, and a camera module 103.

[0065] The housing 101 has a receiving space for accommodating various components of the terminal device 100, such as the battery, antenna, circuit board, and the aforementioned camera module 103. Simultaneously, the housing 101 also serves to protect the terminal device 100. The display screen 102 can be mounted on one side of the housing 101. In some embodiments, the housing 101 includes a back cover and a mid-frame, with the display screen 102 and camera module 103 fixed to the mid-frame, and the display screen 102 and back cover located on opposite sides of the mid-frame. The material of the housing 101 can include one or more of metal, plastic, ceramic, or glass.

[0066] The display screen 102 can be a liquid crystal display (LCD) screen, an organic light emitting diode (OLED) screen, etc., where the OLED screen can be a flexible screen or a rigid screen. The display screen 102 can be a non-foldable screen or a foldable screen. For example, the terminal device 100 also includes a hinge mechanism. Under the action of the hinge mechanism, the two main parts of the display screen 102 can be folded or unfolded relative to each other. When the display screen 102 is in the folded state, the section of the display screen 102 near the hinge mechanism can be folded into an arc shape, a spherical shape, or a teardrop shape. The display screen 102 can be disposed on the front of the terminal device 100, the back of the terminal device 100, or both the front and back of the terminal device 100. The front of the terminal device 100 can be understood as the side facing the user when using the terminal device 100, specifically as follows... Figure 1 As shown; the back of the terminal device 100 can be understood as the side facing away from the user when using the terminal device 100, specifically as follows: Figure 2 As shown.

[0067] Taking the front of the terminal device 100 as an example, in terms of its arrangement range, the display screen 102 can cover the entire area of ​​the front of the terminal device 100. The display screen 102 not only has a display function but also typically has a touch function, meaning that the terminal device 100 can be operated by clicking on the display screen 102. Alternatively, the display screen 102 can only cover a partial area of ​​the front of the terminal device 100. In this case, the display screen 102 can have a touch function or only a display function. When it only has a display function, the area of ​​the housing 101 where the display screen 102 is not located can be configured with corresponding buttons or other human-machine interface elements to operate the terminal device 100. These human-machine interface elements can be located anywhere on the front, back, or side of the terminal device 100.

[0068] The camera module 103 is used to capture still images or videos. When the camera module 103 is disposed on the front of the terminal device 100, it can be used to capture scenes located on one side of the front of the terminal device 100. In some embodiments, the front-facing camera module 103 can be referred to as a front-facing camera. When the camera module 103 is disposed on the back of the terminal device 100, it can be used to capture scenes located on one side of the back of the terminal device 100. In some embodiments, the rear-facing camera module 103 can be referred to as a rear-facing camera. During shooting, the user can select the appropriate camera module 103 according to the shooting needs. The camera module 103 can be used to capture scenes at different distances, such as far away, near, or macro. This application embodiment does not impose any special limitations.

[0069] It should be understood that Figure 1 The installation position of the camera module 103 is merely illustrative. When the camera module 103 is used as a front-facing camera, the display screen 102 typically needs to have a light-passing hole to allow external light to enter the camera module 103. The front-facing camera can be installed in a suitable position, such as the left side of the earpiece, the upper middle of the terminal device 100, the lower part (or chin) of the terminal device 100, or the four corners of the terminal device 100. When the camera module 103 is used as a rear-facing camera, it can be installed in any position on the back of the terminal device 100, such as the upper left or upper right corner. In some other embodiments, the camera module 103 may not be installed on the main body of the terminal device 100, but on an edge protruding from the main body of the terminal device 100, or on a movable or rotatable component relative to the main body of the terminal device 100, which can extend, retract, or rotate from the main body of the terminal device 100. When the camera module 103 can rotate relative to the terminal device 100, the camera module 103 functions as both a front-facing camera and a rear-facing camera. That is, by rotating the same camera module 103, it can capture images from both the front and back sides of the terminal device 100. In other embodiments, for a foldable terminal device 100, when the display screen 102 can be folded, the camera module 103 can function as either a front-facing camera or a rear-facing camera as the display screen 102 folds.

[0070] This application embodiment does not limit the number of camera modules 103; it can be one, two, four, or even more. For example, one or more camera modules 103 can be set on the front of the terminal device 100, and / or one or more camera modules 103 can be set on the back of the terminal device 100. When multiple camera modules 103 are set, the multiple camera modules 103 can be completely identical or different. For example, the multiple camera modules 103 may have different lens optical parameters, different lens placement positions, different lens shapes, etc. This application embodiment also does not limit the relative positions of the multiple camera modules.

[0071] In this embodiment, the terminal device 100 may further include a protective lens 104 for protecting the camera module 103. The protective lens 104 is disposed on the housing 101 and covers the camera module 103. When the protective lens 104 is used to protect the front-facing camera, it may cover only the front-facing camera module or cover the entire front of the terminal device 100. When the protective lens 104 covers the entire front of the terminal device 100, it can simultaneously protect both the front-facing camera module and the display screen 102. The protective lens 104 is a cover glass (CG). When the protective lens 104 is used to protect the rear-facing camera, it may cover the entire back of the terminal device 100 or be disposed only at the corresponding position on the rear-facing camera module. The material of the protective lens 104 may be glass, sapphire, ceramic, etc., and this embodiment does not impose any special limitations. In some embodiments, the protective lens 104 is transparent, allowing external light from the terminal device 100 to pass through the protective lens 104 and enter the camera module 103.

[0072] in, Figure 1 The structure shown does not constitute a specific limitation on the terminal device 100. The terminal device 100 may include more or fewer components than shown in the figure. For example, the terminal device 100 may also include one or more components such as a battery, flash, fingerprint recognition module, earpiece, buttons, and sensors. The terminal device 100 may also have a different component arrangement than shown in the figure. For ease of understanding, all components in the terminal device 100 except for the camera module 103 can be referred to as the body. The camera module 103 can be installed on the body.

[0073] A camera module typically includes a lens assembly 2 consisting of multiple lenses, usually two or more. A motor assembly can move the lens barrel, which houses the lens assembly, a certain distance or rotate it by a certain angle, enabling autofocus and / or optical image stabilization. In addition to the lenses, the lens assembly 2 also includes an aperture 20, which limits the range of the light beam. The aperture 20 is typically a light aperture formed by overlapping small lobes inside the lens assembly 2; adjusting its opening and closing adjusts the amount of light received by the image sensor. A larger aperture 20 opening allows more light to pass through; a smaller aperture 20 opening allows less light to pass through. The size of the aperture 20 opening can be measured by the aperture value FNO; a larger FNO value indicates a smaller aperture, and a smaller FNO value indicates a larger aperture. Generally, under the same conditions, a larger aperture in the lens assembly 2 indicates that the lens assembly 2 can adapt to more types of environments, and correspondingly, the image quality of the lens assembly 2 is considered to be higher.

[0074] The image sensor includes a light sensor capable of receiving light to form an image. The light sensor generates a photoelectric effect when illuminated to create an image. The image sensor is located on the image plane. Types of light sensors can include charge-coupled devices (CCDs), complementary metal-oxide-semiconductor (CMOS) devices, and photodiodes, etc. Based on color, light sensors can be classified as color light sensors, monochromatic light sensors, infrared light sensors, and grayscale sensors, etc.

[0075] This application provides a lens that, in addition to a lens assembly 2, also includes a focusing assembly 1, which is a liquid lens. The focusing assembly 1 has at least two adjustable curvature interfaces formed by liquid. The curvature of each adjustable interface is adjustable under voltage to achieve focusing of optical power, realize the automatic focusing function of the lens, and thus improve the image quality of the lens.

[0076] The focusing assembly 1 provided in this embodiment includes a flat substrate 10, which can be flat glass, such as optical-grade glass with high transparency. The flat substrate 10 can also be flat plastic, such as polycarbonate or polymethyl methacrylate, which has low cost, strong impact resistance, and is lightweight. Of course, the flat substrate 10 can also be other materials, such as flat ice, whose transparency is close to that of glass.

[0077] In this embodiment, the flat substrate 10 is sealed with at least three layers of liquid, adjacent liquids having the same density and being immiscible, to form an adjustable curvature interface between them. From the object side to the image side, the adjustable curvature interface includes a first adjustable curvature interface and a second adjustable curvature interface. That is, the first and second adjustable curvature interfaces are arranged sequentially along the object side to the image side. The curvature of both the first and second adjustable curvature interfaces can be changed under voltage, thereby changing the optical power of the focusing assembly 1 to achieve the automatic focusing function of the lens.

[0078] Specifically, the liquid in the focusing assembly 1 includes a first liquid layer 11 and a second liquid layer 12. The adjacent interfaces of the first liquid layer 11 and the second liquid layer 12 form a first curvature adjustable interface. The first liquid layer 11 is located on the object side of the first curvature adjustable interface, and the second liquid layer 12 is located on the image side of the first curvature adjustable interface. That is, the first liquid layer 11 and the second liquid layer 12 are arranged sequentially along the object-to-image direction. At least one of the first liquid layer 11 and the second liquid layer 12 is a conductor, so that under the action of voltage, the shape of the first curvature adjustable interface can be changed, thereby changing the curvature of the first curvature adjustable interface. Figure 3where S3 is a first curvature-tunable interface located at the junction of the first liquid layer 11 and the second liquid layer 12. S6 is a second curvature-tunable interface located at the junction of the third liquid layer 13 and the fourth liquid layer 14.

[0079] The refractive index n1 of the first liquid layer 11 and the refractive index n2 of the second liquid layer 12 satisfy the following formula: n1<n2; the Abbe number of each liquid layer is ≥58, that is, the Abbe number of each liquid layer is any value greater than or equal to 58, such as 58, 59, 60, 65, 70, 75, 80, 85 and so on. The Abbe number vd is the dispersion coefficient of the material, and a larger Abbe number indicates lower material dispersion; vd≥58 is beneficial to reducing chromatic aberration introduced by focusing of the liquid lens and obtaining better focusing performance. In the embodiments of the present application, on the basis of the lens assembly 2, the lens is additionally provided with a liquid lens type focusing assembly 1, and the focusing assembly 1 may be located on the object side of the lens assembly 2. That is to say, external light may first enter the focusing assembly 1, the light refracted by the focusing assembly 1 then enters each lens of the lens assembly 2, and is then projected onto the image plane. The focusing assembly 1 facilitates the liquid lens to adjust the optical power while introducing smaller aberrations, so as to obtain better focusing performance.

[0080] For the lenses involved in the foregoing respective implementations, the embodiments of the present application below will further provide preferred conditions for some parameters of the lens, so as to maximize the improvement of the focusing performance of the lens involved in the embodiments of the present application.

[0081] In the embodiments of the present application, when the lens focuses on a macro distance, the effective focal length LF1 of the first curvature-tunable interface and the effective focal length LF2 of the second curvature-tunable interface satisfy the following formula: |LF1 / LF2|<2.1, which can effectively balance the optical power distribution of the two curvature-tunable interfaces, reduce field curvature introduced by optical power variation, and improve focusing performance.

[0082] In the embodiments of the present application, the macro focusing distance d of the lens and the total effective focal length LF of the focusing assembly 1 satisfy the following formula: 0.95<LF / d<1.05. This is beneficial for quickly evaluating the achievable focusing range of the focusing assembly 1, and better adapting to the focusing system.

[0083] In the embodiments of the present application, the total effective focal length f of the lens assembly 2 and the total effective focal length LF of the focusing assembly 1 at the macro focusing distance satisfy the following formula: |f / LF|<0.1, which can effectively balance the optical powers of the lens assembly 2 and the focusing assembly 1, correct aberrations introduced by the optical power variation of the focusing assembly 1, and improve the imaging quality of the system.

[0084] In this embodiment, the lens assembly 2 includes at least a first lens 21 and a second lens 22. The effective focal length f1 of the first lens 21 and the effective focal length f2 of the second lens 22 satisfy the following formula: |f1 / f2| < 2. This facilitates the reasonable allocation of the optical power of the first lens 21 and the second lens 22, allowing light to be reasonably deflected at the first lens 21 and the second lens 22, correcting system aberrations, and improving the system imaging quality.

[0085] In this embodiment, the lens assembly 2 includes a first lens 21. The distance TTL from the object side of the first lens 21 to the image plane on the optical axis, the total effective focal length f of the lens assembly 2, and the aperture value FNO of the lens assembly 2 satisfy the following formula: 2 < (TTL / f) * FNO < 4. This facilitates the rational setting of the length and aperture of the lens assembly 2, and minimizes the size of the lens assembly 2 while increasing the aperture.

[0086] In this embodiment, each lens in the lens assembly 2 is configured to individually image an object at infinity. This allows the focusing assembly to be adapted to different lens assemblies 2 without affecting the design of the lens assembly 2.

[0087] In this embodiment of the application, when focusing on macro, the first curvature adjustable interface is either convex or concave. That is, the first curvature adjustable interface can bulge towards the first liquid layer 11 to form a convex surface, or it can bulge towards the second liquid layer 12 to form a concave surface. Similarly, when focusing on macro, the second curvature adjustable interface can also be either convex or concave. The second curvature adjustable interface can bulge towards the object side to form a convex surface, or it can bulge towards the image side to form a concave surface.

[0088] For example, in the first example, when focusing on macro, both the first and second curvature adjustable interfaces are convex; in the second example, when focusing on macro, both the first and second curvature adjustable interfaces are convex and concave; in the third example, when focusing on macro, both the first and second curvature adjustable interfaces are concave and convex; and in the fourth example, when focusing on macro, both the first and second curvature adjustable interfaces are concave.

[0089] In this way, the first and second curvature adjustable interfaces can form interfaces with different curvatures, meeting the needs of different macro focusing conditions, providing high flexibility and also helping to improve image quality.

[0090] In the embodiments of the present application, the liquid further includes a third liquid layer 13, which is located on the image side of the second liquid layer 12. The flat substrate 10 has a sealed cavity (no reference numeral is shown in the figure), and the first liquid layer 11, the second liquid layer 12 and the third liquid layer 13 are located inside the same sealed cavity. In this way, the focusing assembly 1 has a relatively simple structure and occupies a relatively small space, which is beneficial to the miniaturization design of the lens, and the weight of the lens is relatively light. In the embodiments of the present application, the refractive index n1 of the first liquid layer 11, the refractive index n2 of the second liquid layer 12, and the refractive index n3 of the third liquid layer 13 satisfy the following formulas: n1<n2, and n2>n3. In this embodiment, smaller aberrations can be introduced, which facilitates flexible adjustment of the optical power of the focusing assembly 1 and achieves better focusing performance.

[0091] In an example, the refractive index of the first liquid layer 11 may be the same as that of the third liquid layer 13, for example, the first liquid layer 11 and the third liquid layer 13 are the same liquid. In this way, the types of liquids are relatively few.

[0092] Of course, each liquid may also be located inside different sealed cavities, and several embodiments of the focusing assembly 1 with different structures are given below.

[0093] In the embodiments of the present application, along the direction from the object side to the image side, the flat substrate 10 includes a first sealed cavity and a second sealed cavity (not labeled in the figure) that are relatively isolated. The liquid further includes a third liquid layer 13 and a fourth liquid layer 14. The first liquid layer 11 and the second liquid layer 12 are located in the first sealed cavity, and the third liquid layer 13 and the fourth liquid layer 14 are located in the second sealed cavity. This facilitates the assembly of the liquids.

[0094] In another embodiment, along the direction from the object side to the image side, the flat substrate 10 includes a first flat layer 1-1, a second flat layer 1-2 and a third flat layer 1-3. The first sealed cavity is formed between the first flat layer 1-1 and the second flat layer 1-2, and the second sealed cavity is formed between the second flat layer 1-2 and the third flat layer 1-3. In this embodiment, the isolation between the first sealed cavity and the second sealed cavity can be achieved with only three flat layers along the optical axis direction. The number of layers of the flat substrate 10 is relatively small, which minimizes the influence on the focusing performance of the focusing assembly 1. Moreover, the focusing assembly 1 has a relatively compact structure and occupies a relatively small space.

[0095] In another embodiment, along the direction from the object side to the image side, the flat substrate 10 includes a first flat plate layer 1-1, a second flat plate layer 1-2, a third flat plate layer 1-3 and a fourth flat plate layer 1-4. The first sealed cavity is formed between the first flat plate layer 1-1 and the second flat plate layer 1-2, the second sealed cavity is formed between the third flat plate layer 1-3 and the fourth flat plate layer 1-4, and the second flat plate layer 1-2 and the third flat plate layer 1-3 are arranged in close contact. In this way, on the basis of realizing that the main bodies of the first sealed cavity and the second sealed cavity are relatively independent, the space occupied by the flat substrate 10 is relatively small, which is beneficial to the miniaturization of the lens.

[0096] In another embodiment, along the direction from the object side to the image side, the flat substrate 10 includes a first flat plate layer 1-1, a second flat plate layer 1-2, a third flat plate layer 1-3 and a fourth flat plate layer 1-4. The first sealed cavity is formed between the first flat plate layer 1-1 and the second flat plate layer 1-2, the second sealed cavity is formed between the third flat plate layer 1-3 and the fourth flat plate layer 1-4, and the second flat plate layer 1-2 and the third flat plate layer 1-3 have a predetermined spacing. The structural member formed by the first flat plate layer 1-1 and the second flat plate layer 1-2 may be the same as the structural member formed by the third flat plate layer 1-3 and the fourth flat plate layer 1-4.

[0097] In the above two embodiments, the first sealed cavity and the second sealed cavity may be respectively formed by different flat plate structures. A single flat plate structure is relatively simple and easy to form, and the two flat plate structures are relatively independent without affecting each other, with relatively high layout flexibility.

[0098] In the embodiment of the present application, the fourth liquid layer 14 is located on the image side of the third liquid layer 13. The refractive index n1 of the first liquid layer 11, the refractive index n2 of the second liquid layer 12, the refractive index n3 of the third liquid layer 13, and the refractive index n4 of the fourth liquid layer 14, each parameter satisfies the following formulas: n1<n2, and n3<n4. In this embodiment, smaller optical aberrations can be introduced, and better focusing performance can be obtained.

[0099] Wherein, the first liquid layer 11 and the third liquid layer 13 may be the same liquid, and the second liquid layer 12 and the fourth liquid layer 14 may be the same liquid. In this way, the first flat plate layer 1-1, the second flat plate layer 1-2, the first liquid layer 11, and the second liquid layer 12 form a unit member, and the focusing assembly may be formed by two completely identical unit members arranged at intervals, with a simpler structure.

[0100] Of course, the refractive indices of the respective liquid layers may also be completely different, that is, the types of the respective liquids may be completely different.

[0101] In this embodiment, the thickness of the flat substrate 10 does not affect the focusing performance of the focusing assembly 1. That is, by reasonably setting the thickness of the flat substrate 10, the focusing performance of the focusing assembly 1 can be left unaffected. It should be noted that the thickness of the flat substrate is the distance from the object side surface of the flat substrate 10 to the image side surface of the flat substrate 10 in the optical axis (horizontal) direction.

[0102] The lens assembly 2 provided in this embodiment may further include an aperture stop 20, which can be disposed on the object side of the first lens 21, resulting in a simple structure. The aperture stop 20 may also be disposed between the first lens 21 and the second lens 22. The specific distance between the aperture stop 20 and the first lens 21 and the second lens 22 is not limited here; in practical applications, those skilled in the art can design it as needed. The aperture stop 20, located between the first lens 21 and the second lens 22, can limit the range of the light beam, thereby balancing the difference in lens aperture before and after the aperture stop 20. Furthermore, the placement of the aperture stop 20 between the first lens 21 and the second lens 22 enables the lens to have a larger aperture, achieving the performance requirements of a large aperture lens.

[0103] The lens assembly 2 provided in this embodiment may further include a filter 26, which may be disposed on the image side of the last lens. The filter 26 can filter out light beams of a specified wavelength, thereby highlighting light beams of other wavelengths and making the image more vivid.

[0104] Here, the embodiments of this application do not limit the type of filter 26. In practice, those skilled in the art can configure it according to actual needs. For example, the filter 26 can be an infrared cut-off filter to filter out infrared light in the infrared region, thereby reducing image distortion caused by infrared light and enabling the acquisition of higher quality color images; or, the filter 26 can also be a monochrome filter, thereby increasing the amount of light entering the filter to obtain a clearer image. This implementation is particularly suitable for use in low-light scenarios such as at night, such as in night vision devices.

[0105] In summary, the embodiments of this application employ a lens assembly 2 and a liquid lens combination, and with the aforementioned design conditions, through reasonable optical power allocation and optical performance optimization, the focusing performance can be further improved, and it has advantages such as compact structure and high imaging quality.

[0106] The following embodiments of this application will also illustrate several specific examples of lenses that satisfy the above conditions with reference to the accompanying drawings.

[0107] Example 1

[0108] Please refer to Figures 3-6 , Figure 3 This is a schematic diagram of the structure of a first embodiment of the lens provided in this application. Figure 4 for Figure 3 MTF curve of the medium lens at a focusing distance of 20cm using focusing assembly 1. Figure 5 for Figure 3 A schematic diagram of the structure of lens assembly 2 shown in the diagram, which forms an image independently at a focusing distance of 20cm. Figure 6 for Figure 5 The MTF curve of lens assembly 2 is shown; where Figure 4 and Figure 6 The solid line curve represents the meridional field curve T, and the dashed line curve represents the sagittal field curve S. The horizontal axis represents the Y field of view, and the vertical axis represents the MTF value.

[0109] like Figure 3 As shown, from the object side to the image side, the lens assembly 2 sequentially includes an aperture stop 20, a first lens 21, a second lens 22, a third lens 23, a fourth lens 24, a fifth lens 25, and a filter 26. The filter 26 can be an infrared cutoff filter. Figure 3 The imaging region P1P2 on the image plane 27 is also shown. The focusing assembly 1 is located on the object side of the lens assembly 2. The flat substrate 10 of the focusing assembly 1 is flat glass. Along the direction from the object side to the image side, the flat glass includes three layers: a first flat layer 1-1, a second flat layer 1-2, and a third flat layer 1-3. The focusing assembly 1 includes four liquid layers: a first liquid layer 11, a second liquid layer 12, a third liquid layer 13, and a fourth liquid layer 14. The first liquid layer 11 and the second liquid layer 12 are encapsulated between the first flat layer 1-1 and the second flat layer 1-2, and the third liquid layer 13 and the fourth liquid layer 14 are encapsulated between the second flat layer 1-2 and the third flat layer 1-3. That is, a first sealed cavity is formed between the first flat layer 1-1 and the second flat layer 1-2, and a second sealed cavity is formed between the second flat layer 1-2 and the third flat layer 1-3. The circumferential sealing of the first flat layer 1-1 and the second flat layer 1-2 can be achieved through the flat glass or through other materials. Similarly, the circumferential sealing of the second flat layer 1-2 and the third flat layer 1-3 can also be achieved using flat glass or other materials.

[0110] like Figure 3 S3 is the first adjustable curvature interface, located at the junction of the first liquid layer 11 and the second liquid layer 12. S6 is the second adjustable curvature interface, located at the junction of the third liquid layer 13 and the fourth liquid layer 14.

[0111] Table 1 below shows the relevant parameters of each lens in the lens and each structure in the focusing assembly 1 in Embodiment 1. The units for Y-radius (radius of curvature), thickness, and focal length are all mm. As can be seen from Table 1, the first lens 21 to the fifth lens 25 in Embodiment 1 are all aspherical lenses. The surface shape x of each aspherical lens can be calculated using the following formula (not limited to):

[0112]

[0113] Where x is the distance vector from the vertex of the aspherical surface at a height h along the optical axis; c is the paraxial curvature of the aspherical surface, c = 1 / R (i.e., the paraxial curvature c is the reciprocal of the radius of curvature in Table 1 above); k is the conic coefficient; Ai is the i-th order correction coefficient of the aspherical surface. Tables 2-1 and 2-2 below give the coefficients k, A4, A6, A8, A10, A12, A14, A16, A18, A20, and A22 that can be used on the object side / image side of each aspherical lens in Example 1.

[0114] Table 1. Parameters of focusing assembly 1, aperture 20, lenses, and filters in Example 1

[0115]

[0116]

[0117] In the table, f represents the total effective focal length of the lens assembly, FNO represents the aperture value of the lens assembly, TTL represents the distance on the optical axis from the object side of the first lens to the image plane, and FOV represents the field of view of the lens assembly. The virtual surface in the table refers to the first surface of the lens, not shown in the figure. The thickness corresponding to the virtual surface represents the distance from the aperture stop S20 to the first surface of the lens assembly 2. The thickness in the table represents the distance from this surface to the image plane.

[0118] The first lens 21 has an object-side surface S11 and an image-side surface S12; the second lens 22 has an object-side surface S13 and an image-side surface S14; the third lens 23 has an object-side surface S15 and an image-side surface S16; the fourth lens 24 has an object-side surface S17 and an image-side surface S18; the fifth lens 25 has an object-side surface S19 and an image-side surface S20; and the filter has an object-side surface IR1 and an image-side surface IR2. The first flat plate layer has an object-side surface S1 and an image-side surface S2; a first curvature-adjustable interface S3 is formed at the junction of the first liquid layer 11 and the second liquid layer 12; the second flat plate layer has an object-side surface S4 and an image-side surface S5; a first curvature-adjustable interface S6 is formed at the junction of the third liquid layer 13 and the fourth liquid layer 14; and the third flat plate layer has an object-side surface S7 and an image-side surface S8.

[0119] Table 2-1 Partial coefficients of each surface of the first to fifth lenses in Example 1

[0120]

[0121]

[0122] Table 2-2 shows another part of the correlation coefficients of each surface of the first to fifth lenses in Example 1.

[0123] Face number A14 A16 A18 A20 A22 S11 -7.54239E-06 1.03252E-06 -8.72539E-08 4.15314E-09 -8.56172E-11 S12 -1.18959E-05 1.72205E-06 -1.66718E-07 9.40107E-09 -2.29729E-10 S13 -8.55230E-06 2.74766E-06 -5.04571E-07 4.50967E-08 -1.58551E-09 S14 -1.77342E-04 5.72117E-05 -1.05001E-05 1.02408E-06 -4.15087E-08 S15 -3.72588E-04 9.24414E-05 -1.38998E-05 1.16081E-06 -4.14237E-08 S16 4.60642E-04 -1.44238E-04 2.85804E-05 -3.19017E-06 1.52820E-07 S17 -7.95315E-05 1.30527E-05 -8.84699E-07 -1.47125E-08 2.73938E-09 S18 4.74359E-04 -9.52502E-05 1.23584E-05 -9.16804E-07 2.87366E-08 S19 -6.82088E-04 1.28751E-04 -1.58257E-05 1.14403E-06 -3.68674E-08 S20 -8.90912E-05 1.20223E-05 -1.00237E-06 4.54345E-08 -7.68426E-10

[0124] Figure 4 and Figure 6 The curve shown can be seen that, Figure 4 The distance between the mid-arc sagittal field curve and the meridional field curve is relatively close, resulting in more consistent imaging in different directions and less astigmatism. The lens provided in this embodiment has good imaging quality.

[0125] Example 2

[0126] Please refer to Figures 7-10 , Figure 7 This is a schematic diagram of the structure of a second embodiment of the lens provided in this application. Figure 8 for Figure 7 MTF curve of the medium lens at 30cm focusing distance using the focusing assembly. Figure 9 for Figure 7 A schematic diagram of the lens assembly shown in the diagram, demonstrating its ability to image independently at a focusing distance of 30cm. Figure 10 for Figure 9 The MTF curve of the lens assembly shown is as follows; where Figure 7 and Figure 10 The solid line curve represents the meridional field curve T, and the dashed line curve represents the sagittal field curve S. The horizontal axis represents the Y field of view, and the vertical axis represents the MTF value.

[0127] like Figure 7 As shown, this application provides a second implementation method, in which the number of lenses in the lens assembly is the same as in the first embodiment, and will not be repeated here. The structure of the focusing assembly is also basically the same as in the embodiment, except that the shapes of the object side and image side of the lens are different, and the shapes of the first curvature adjustable interface and the second curvature adjustable interface are different.

[0128] like Figure 7 S3 is the first adjustable curvature interface, located at the junction of the first liquid layer 11 and the second liquid layer 12. S6 is the second adjustable curvature interface, located at the junction of the third liquid layer 13 and the fourth liquid layer 14.

[0129] Table 3 below shows the relevant parameters of the focusing assembly and each lens in Embodiment 2. The units for Y-radius, thickness, and focal length are all mm. As can be seen from Table 3, the first to fifth object lenses in Embodiment 2 are all aspherical lenses. The filter is an infrared cutoff filter. Tables 4-1 and 4-2 below give the coefficients k, A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used on the object-side / image-side surfaces of each aspherical lens in Embodiment 2.

[0130] Table 3. Parameters of the focusing assembly, lenses, and filters in Example 2

[0131]

[0132] Table 4-1 Partial coefficients of the first to fifth lenses in Example 2

[0133]

[0134]

[0135] Table 4-2 shows another set of coefficients for the first to fifth lenses in Example 2.

[0136] Face number A14 A16 A18 A20 S11 -3.54317E-09 1.29171E-10 -2.57806E-12 2.15023E-14 S12 1.12274E-07 -3.58894E-09 6.48490E-11 -5.08601E-13 S13 1.08294E-07 -3.49966E-09 6.39958E-11 -5.09074E-13 S14 -1.96860E-07 9.65908E-09 -2.52820E-10 2.73832E-12 S15 -1.72331E-07 8.12658E-09 -2.00416E-10 1.98658E-12 S16 5.92736E-07 -3.65495E-08 1.24512E-09 -1.79633E-11 S17 3.27745E-07 -2.13188E-08 7.58355E-10 -1.13421E-11 S18 -1.67543E-08 5.15516E-10 -3.59373E-12 -1.16971E-13 S19 -1.02140E-07 5.75527E-09 -1.76861E-10 2.11700E-12 S20 -1.12260E-07 6.70123E-09 -2.26510E-10 3.30742E-12

[0137] Figure 8 and Figure 10 The curve shown can be seen that, Figure 8 The distance between the mid-arc sagittal field curve and the meridional field curve is relatively close, resulting in more consistent imaging in different directions and less astigmatism. The lens provided in this embodiment has good imaging quality.

[0138] Example 3

[0139] Please refer to Figures 11-14 , Figure 11 This is a schematic diagram of a third embodiment of the lens provided in this application. Figure 12 for Figure 11 MTF curve of the medium lens at 50cm focusing distance using the focusing assembly. Figure 13 for Figure 11 A schematic diagram of the lens assembly shown in the diagram, demonstrating its ability to image independently at a focusing distance of 50cm. Figure 14 for Figure 13 The MTF curve of the lens assembly shown is as follows; where Figure 12 and Figure 14 The solid line curve represents the meridional field curve T, and the dashed line curve represents the sagittal field curve S. The horizontal axis represents the Y field of view, and the vertical axis represents the MTF value.

[0140] like Figure 11 As shown, this application provides a third implementation method, which differs from the first and second embodiments in that the structure of the lens assembly 2 and the focusing assembly are different. From the object side to the image side, the lens assembly 2 in this embodiment includes a first lens 21, a second lens 22, a third lens 23, a prism 30, and a filter 26. The prism 30 has an object side surface S19 and an image side surface S20. The first lens 21 is a spherical lens, all prisms 30 are spherical prisms, and the second lens 22 and the third lens 23 are aspherical lenses.

[0141] From the object side to the image side, the flat glass comprises four layers: a first flat layer 1-1, a second flat layer 1-2, a third flat layer 1-3, and a fourth flat layer 1-4. The focusing assembly 1 comprises four liquid layers: a first liquid layer 11, a second liquid layer 12, a third liquid layer 13, and a fourth liquid layer 14. The first liquid layer 11 and the second liquid layer 12 are encapsulated between the first flat layer 1-1 and the second flat layer 1-2, and the third liquid layer 13 and the fourth liquid layer 14 are encapsulated between the third flat layer 1-3 and the fourth flat layer 1-4. The second flat layer 1-2 and the third flat layer 1-3 are spaced apart by a predetermined distance. That is, there is an air layer or other medium between the second flat layer 1-2 and the third flat layer 1-3.

[0142] like Figure 11 S3 is the first adjustable curvature interface, located at the junction of the first liquid layer 11 and the second liquid layer 12. S8 is the second adjustable curvature interface, located at the junction of the third liquid layer 13 and the fourth liquid layer 14.

[0143] Table 5 below shows the relevant parameters of each lens in Example 3. The units for radius of curvature, thickness, and focal length are all mm. Tables 6-1 and 6-2 below give the coefficients k, A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used on the object side / image side of each lens in Example 3.

[0144] Table 5. Parameters of the focusing assembly, aperture, lenses, and filters in Example 3

[0145]

[0146]

[0147] Table 6-1 Partial coefficients of the first to third lenses in Example 3

[0148] Face number K A4 A6 A8 A10 S15 0.05 -4.24465E-04 2.33110E-04 -8.58279E-05 7.87316E-06 S16 64.15 1.37794E-04 5.23969E-04 -8.12737E-04 4.20656E-04 S17 6.81 9.08807E-04 -3.63522E-04 -3.32175E-04 2.82426E-04 S18 0.17 1.14197E-03 -1.29787E-03 9.79352E-04 -4.49793E-04

[0149] Table 6-2 shows another set of coefficients for the first to third lenses in Example 3.

[0150] Face number A12 A14 A16 A18 A20 S15 3.34807E-06 -1.08983E-06 1.34999E-07 -7.84530E-09 1.77539E-10 S16 -1.09897E-04 1.61923E-05 -1.36246E-06 6.11130E-08 -1.13428E-09 S17 -8.99104E-05 1.51072E-05 -1.41690E-06 7.02400E-08 -1.43824E-09 S18 1.26644E-04 -2.22717E-05 2.38795E-06 -1.42768E-07 3.63108E-09

[0151] Figure 12 and Figure 14 The curve shown can be seen that, Figure 12 The distance between the mid-arc sagittal field curve and the meridional field curve is relatively close, resulting in more consistent imaging in different directions and less astigmatism. The lens provided in this embodiment has good imaging quality.

[0152] Example 4

[0153] Please refer to Figures 15-18 , Figure 15 This is a schematic diagram of the fourth embodiment of the lens provided in this application. Figure 16 for Figure 15 MTF curve of the medium lens at 20cm focusing distance using the focusing assembly. Figure 17 for Figure 15 A schematic diagram of the lens assembly shown in the diagram, demonstrating its ability to image independently at a focusing distance of 20cm. Figure 18 for Figure 17 The MTF curve of the lens assembly shown is as follows; where Figure 16 and Figure 18 The solid line curve represents the meridional field curve T, and the dashed line curve represents the sagittal field curve S. The horizontal axis represents the Y field of view, and the vertical axis represents the MTF value.

[0154] like Figure 15 As shown in the embodiment, this application provides a fourth implementation. In this embodiment, the lens assembly includes seven lenses in the direction from the object side to the image side. The seven lenses are: first lens 21, second lens 22, third lens 23, fourth lens 24, fifth lens 25, sixth lens 28, and seventh lens 29. The structure of the focusing assembly is basically the same as that in the first example, except that the refractive index and Abbe number of the internal liquid are different.

[0155] like Figure 15 S3 is the first adjustable curvature interface, located at the junction of the first liquid layer 11 and the second liquid layer 12. S6 is the second adjustable curvature interface, located at the junction of the third liquid layer 13 and the fourth liquid layer 14.

[0156] Table 7 below shows the relevant parameters of each lens in Example 4. The units for Y-radius, thickness, and focal length are all mm. As can be seen from Table 7, all lenses in Example 4 are aspherical lenses. Tables 8-1, 8-2, and 8-3 below give the coefficients k, A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 for the object-side / image-side surfaces that can be used for each aspherical lens in Example 4.

[0157] Table 7. Parameters of the focusing assembly, aperture, lenses, and filters in Example 4

[0158]

[0159]

[0160] In Table 7, the virtual surface corresponding to surface number 15 is a light-blocking position between the second and third lenses.

[0161] Table 8-1 Partial coefficients of each surface of the first to seventh lenses in Example 4

[0162] Face number K A4 A6 A8 A10 A12 S11 0.00 -8.56229E-04 3.74661E-03 -8.68623E-03 1.28087E-02 -1.25378E-02 S12 0.00 -4.96576E-03 2.72463E-03 -9.32290E-03 2.09186E-02 -2.75586E-02 S13 0.00 -1.14810E-02 7.51618E-03 -1.15372E-02 1.56973E-02 -1.32597E-02 S14 0.00 -6.68648E-03 1.65823E-03 1.88192E-03 -2.51490E-03 -6.28257E-04 0.00 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 S16 0.00 -1.60282E-02 5.58241E-03 -2.12514E-02 4.45765E-02 -6.13403E-02 S17 0.00 -1.01955E-02 -6.57077E-03 8.07415E-03 -9.48749E-03 7.70945E-03 S18 0.00 3.68671E-04 -8.23787E-03 1.16105E-02 -1.47115E-02 1.26626E-02 S19 0.00 -6.64013E-03 -1.04219E-03 3.88743E-03 -5.70621E-03 5.14678E-03 S20 0.00 -1.99434E-02 8.66815E-03 -5.36020E-03 3.07172E-03 -1.35851E-03 S21 0.00 -4.17578E-02 1.76317E-02 -9.59948E-03 4.81862E-03 -1.87755E-03 S22 -1.00 -1.80944E-02 6.26414E-03 -2.72419E-03 9.08386E-04 -2.45062E-04 S23 0.00 4.88991E-03 2.60689E-04 -5.65945E-04 1.11863E-04 -9.75822E-06 S24 0.00 -5.27768E-02 9.32620E-03 -1.09839E-03 3.45823E-05 1.21095E-05 S25 -1.00 -5.69743E-02 1.28860E-02 -2.38752E-03 3.35062E-04 -3.54431E-05

[0163] Table 8-2 shows another set of coefficients for each surface of the first to seventh lenses in Example 4.

[0164]

[0165]

[0166] Table 8-3 shows another set of coefficients for each surface of the first to seventh lenses in Example 4.

[0167] Face number A24 A26 A28 A30 S11 -7.16252E-06 5.71822E-07 -2.70510E-08 5.74288E-10 S12 -4.67939E-05 4.33905E-06 -2.37884E-07 5.84350E-09 S13 1.93040E-05 -2.44040E-06 1.72414E-07 -5.27288E-09 S14 -2.21493E-04 3.08314E-05 -2.49118E-06 8.89619E-08 0.00000E+00 0.00000E+00 0.00000E+00 0.00000E+00 S16 -3.00002E-04 3.49281E-05 -2.42186E-06 7.57467E-08 S17 -2.06239E-06 2.69564E-07 -1.84211E-08 5.31284E-10 S18 2.23921E-06 -1.44166E-07 5.44011E-09 -9.06369E-11 S19 1.53159E-06 -1.09567E-07 4.64458E-09 -8.83018E-11 S20 -3.56366E-09 2.77501E-11 2.69505E-12 -7.25454E-14 S21 -7.94330E-09 2.89830E-10 -6.30093E-12 6.17462E-14 S22 -2.36384E-10 6.90429E-12 -1.19415E-13 9.23604E-16 S23 1.47578E-12 -3.02820E-14 3.63663E-16 -1.94367E-18 S24 2.50187E-13 -3.12863E-15 2.32193E-17 -7.75984E-20 S25 -1.01523E-13 1.14003E-15 -7.62456E-18 2.29434E-20

[0168] Figure 16 and Figure 18 The curve shown can be seen that, Figure 16 The distance between the mid-arc sagittal field curve and the meridional field curve is relatively close, resulting in more consistent imaging in different directions and less astigmatism. The lens provided in this embodiment has good imaging quality.

[0169] Example 5

[0170] Please refer to Figures 19-22 , Figure 19 This is a schematic diagram illustrating the structure of a fifth embodiment of the lens provided in this application. Figure 20 for Figure 19 MTF curve of the medium lens at 20cm focusing distance using the focusing assembly. Figure 21 for Figure 19 A schematic diagram of the lens assembly shown in the diagram, demonstrating its ability to image independently at a focusing distance of 20cm. Figure 22 for Figure 21 The MTF curve of the lens assembly shown is as follows; where Figure 20 and Figure 22 The solid line curve represents the meridional field curve T, and the dashed line curve represents the sagittal field curve S. The horizontal axis represents the Y field of view, and the vertical axis represents the MTF value.

[0171] like Figure 19 As shown, this application provides a fifth implementation method, which differs from the above embodiments in the structure of the lens number focusing assembly.

[0172] The lens assembly contains four lenses, while the focusing assembly includes only the first plate layer 1-1 and the second plate layer 1-2. There are three layers of liquid, arranged from the object side to the image side: a first liquid layer 11, a second liquid layer 12, and a third liquid layer 13. These three liquid layers are sealed between the first plate layer 1-1 and the second plate layer 1-2.

[0173] like Figure 19S3 is the first adjustable curvature interface, located at the junction of the first liquid layer 11 and the second liquid layer 12. S4 is the second adjustable curvature interface, located at the junction of the second liquid layer 12 and the third liquid layer 13.

[0174] Table 9 below shows the relevant parameters of the focusing assembly 1 and each lens in Embodiment 5. The units for radius of curvature, thickness, and focal length are all mm. As can be seen from Table 9, all lenses in Embodiment 5 are aspherical lenses, and the filters are infrared cut-off filters. Tables 10-1 and 10-2 below give the coefficients k, A4, A6, A8, A10, A12, A14, A16, and A18 that can be used on the object side / image side of each aspherical lens in Embodiment 5.

[0175] Table 9. Parameters of the focusing assembly, aperture, lenses, and filters in Example 5

[0176]

[0177] Table 10-1 Partial coefficients of each surface of the first to fourth lenses in Example 5

[0178] Face number K A4 A6 A8 A10 A12 S9 -0.44 3.85061E-02 3.23179E-02 -4.92780E-03 8.69425E-03 1.22647E-02 S10 -3.95 5.90590E-02 -6.76202E-03 -1.01751E-02 1.53736E-02 -5.07939E-04 S11 -40.51 -1.28734E-03 -7.24816E-04 1.69548E-04 6.08944E-05 -5.87954E-05 S12 0.38 -1.48800E-02 2.52328E-04 -9.67931E-05 2.88568E-04 -3.53563E-04 S13 -10.48 2.67838E-03 8.26588E-03 -4.33220E-03 2.43628E-03 -8.23753E-04 S14 -3.44 1.94277E-02 -4.61851E-03 1.20790E-03 2.62509E-04 -8.09065E-05 S15 -11.56 -2.38701E-02 1.28564E-03 -8.26545E-04 1.09403E-04 -1.44465E-05 S16 -17.21 -2.72648E-02 1.88603E-03 -3.65349E-04 -1.31000E-04 3.95579E-05

[0179] Table 10-2 shows another set of coefficients for each surface of the first to fourth lenses in Example 5.

[0180] Face number A14 A16 A18 S9 4.35551E-03 -1.38253E-02 8.63624E-03 S10 -1.46527E-02 1.12610E-02 -2.75937E-03 S11 1.41551E-05 -1.18062E-06 S12 1.22458E-04 -1.60200E-05 S13 1.78335E-04 -1.51703E-05 S14 -8.84371E-06 8.59785E-06 S15 3.80034E-06 -3.48737E-07 S16 -9.83698E-07 -6.80200E-07

[0181] Figure 20 and Figure 22 The curve shown can be seen that, Figure 20 The distance between the mid-arc sagittal field curve and the meridional field curve is relatively close, resulting in more consistent imaging in different directions and less astigmatism. The lens provided in this embodiment has good imaging quality.

[0182] Since the lens described above has the aforementioned technical effects, the terminal device equipped with the lens should also have similar technical effects, so it will not be elaborated here.

[0183] The above are merely preferred embodiments of this application. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A lens, characterized in that, comprising: a lens assembly, wherein the lens assembly comprises at least three lenses; a focusing assembly, wherein the focusing assembly comprises a flat substrate, at least three layers of liquid are sealed inside the flat substrate, adjacent liquids have the same density and are immiscible with each other to form curvature-adjustable interfaces, and in the direction from the object side to the image side, the curvature-adjustable interfaces include a first curvature-adjustable interface and a second curvature-adjustable interface; The curvature of the first curvature-adjustable interface and the curvature of the second curvature-adjustable interface can both be changed under the action of voltage, so as to change the optical power of the focusing assembly, thereby realizing the auto-focus function of the lens; The liquids include a first liquid layer located on the object side of the first curvature-adjustable interface, and a second liquid layer located on the image side of the first curvature-adjustable interface. The refractive index n1 of the first liquid layer and the refractive index n2 of the second liquid layer satisfy the following formula: n1<n2; the Abbe number of each layer of the liquid is ≥58.

2. The lens according to claim 1, characterized in that, When the lens is focused at a macro distance, the effective focal length LF1 of the first curvature-adjustable interface and the effective focal length LF2 of the second curvature-adjustable interface satisfy the following formula: |LF1 / LF2|<2.

1.

3. The lens according to claim 1 or 2, characterized in that, The macro focusing distance d of the lens and the total effective focal length LF of the focusing assembly satisfy the following formula: 0.95<LF / d<1.

05.

4. The lens according to any one of claims 1 to 3, characterized in that, The total effective focal length f of the lens assembly and the total effective focal length LF of the focusing assembly when focusing at the macro distance satisfy the following formula: |f / LF|<0.

1.

5. The lens according to any one of claims 1 to 4, characterized in that, The lens assembly at least includes a first lens and a second lens, and the effective focal length f1 of the first lens and the effective focal length f2 of the second lens satisfy the following formula: |f1 / f2|<2.

6. The lens according to any one of claims 1 to 5, characterized in that, The lens assembly includes a first lens, and the distance TTL on the optical axis from the object side surface of the first lens to the image plane, the total effective focal length f of the lens assembly, and the aperture value FNO of the lens assembly satisfy the following formula: 2<(TTL / f)*FNO<4.

7. The lens according to any one of claims 1 to 6, characterized in that, The lens assembly is configured as a structure capable of imaging an object at an infinite object distance independently.

8. The lens according to any one of claims 1 to 7, characterized in that, When focusing at the macro distance, the first curvature-adjustable interface is a convex surface or a concave surface, and the second curvature-adjustable interface is a convex surface or a concave surface.

9. The lens according to any one of claims 1 to 8, characterized in that, The liquids further include a third liquid layer, the third liquid layer is located on the image side of the second liquid layer, the flat substrate is provided with a sealed cavity, and the first liquid layer, the second liquid layer and the third liquid layer are located inside the same sealed cavity.

10. The lens according to claim 9, characterized in that, The refractive index n2 of the second liquid layer and the refractive index n3 of the third liquid layer satisfy the following formula: n2>n3.

11. The lens according to any one of claims 1 to 8, characterized in that, Along the direction from the object side to the image side, the flat substrate includes a first sealed cavity and a second sealed cavity which are isolated from each other, the liquids further include a third liquid layer and a fourth liquid layer, the first liquid layer and the second liquid layer are located in the first sealed cavity, and the third liquid layer and the fourth liquid layer are located in the second sealed cavity.

12. The lens according to claim 11, characterized in that, Along the object-to-image direction, the flat substrate includes a first flat layer, a second flat layer, and a third flat layer, with a first sealing cavity formed between the first flat layer and the second flat layer, and a second sealing cavity formed between the second flat layer and the third flat layer; Alternatively, along the object-to-image direction, the flat substrate includes a first flat layer, a second flat layer, a third flat layer, and a fourth flat layer, with the first sealing cavity formed between the first flat layer and the second flat layer, the second sealing cavity formed between the third flat layer and the fourth flat layer, and the second flat layer and the third flat layer being bonded together. Alternatively, along the object-to-image direction, the flat substrate includes a first flat layer, a second flat layer, a third flat layer, and a fourth flat layer, with a first sealing cavity formed between the first flat layer and the second flat layer, a second sealing cavity formed between the third flat layer and the fourth flat layer, and the second flat layer and the third flat layer having a predetermined spacing.

13. The lens according to claim 11 or 12, characterized in that, The fourth liquid layer is located on the image side of the third liquid layer, and the refractive index n3 of the third liquid layer and the refractive index n4 of the fourth liquid layer satisfy the following formula: n3 <n4。 14. The lens according to any one of claims 1 to 13, characterized in that, The thickness of the flat substrate does not affect the focusing performance of the focusing assembly.

15. The lens according to any one of claims 1 to 14, characterized in that, The flat substrate includes flat glass, flat plastic, or flat ice.

16. A camera module, characterized in that, Includes the lens described in any one of claims 1-15.

17. A terminal device, characterized in that, Includes the body and the camera module as described in claim 16.

Images