Optical imaging lens including liquid lens

Abstract

The present invention relates to an optical imaging lens including a liquid lens, comprising first to fifth lenses, a liquid lens, and sixth to ninth lenses; the first lens has a positive refractive power, and its object-side surface is convex; the second lens has a negative refractive power, its object-side surface is convex, and its image-side surface is concave; the third lens has a negative refractive power, its object-side surface is concave, and its image-side surface is concave; the fourth lens has a positive refractive power, its object-side surface is concave, and its image-side surface is convex; the fifth lens has a positive refractive power, and its object-side surface is convex; the sixth lens has a positive refractive power, and its image-side surface is convex; the seventh lens has a negative refractive power, and its object-side surface is concave; the eighth lens has a positive refractive power, and its image-side surface is convex; the ninth lens has a positive refractive power, and its object-side surface is convex; the sixth and seventh lenses are glued together. The optical imaging lens of the present invention can achieve a fast focusing function and has a long service life.

Description

Technical Field

[0001] The present invention relates to the technical field of optical lenses, and in particular to an optical imaging lens comprising a liquid lens. Background Art

[0002] In machine vision, the field of view and working distance vary, requiring focus to change as well, otherwise image quality will be severely impacted. Lens focus has always been a difficult problem to solve. Previously, solutions have been used to change the focus by moving the lens, which simultaneously changes the field of view and focus.

[0003] In high-speed or precision applications that require rapid refocusing, traditional imaging lenses struggle to capture sharp, accurate images. Liquid lenses overcome these limitations by enabling rapid focus adjustment to accommodate objects at varying working distances or heights. Liquid lenses are small components containing an optical-grade liquid that changes shape when an electric current or voltage is applied. This change, occurring within milliseconds, causes the optical power of the lens to vary, altering the focal length and working distance. Integrating liquid lenses into imaging systems is an ideal solution for applications requiring fast focus, high throughput, and adaptability to depth of field and working distance.

[0004] In recent years, autofocus technology using curvature-variable liquid lenses has enhanced the capabilities of individual cameras, eliminating complex mechanical structures and transforming numerous industries and other applications, enabling them to instantly adapt to different distances and types of objects. Liquid lenses are far superior to any other method in terms of speed and ease of use.

[0005] Liquid lenses are also significantly smaller and lighter than mechanical lenses of comparable specifications. They require no focusing mechanism, nor do they require lens movement to change focus, thus reducing the camera's size and weight. Liquid lens cameras can be used in production lines and package handling applications where space constraints preclude the installation of traditional cameras.

[0006] While optical lenses with liquid lenses have begun to appear on the market in the past two years, they still have some shortcomings, such as low resolution and poor imaging quality. Therefore, there is still a need to improve the optical design of optical lenses with liquid lenses in the existing technology. Summary of the Invention

[0007] The main purpose of the present invention is to provide an optical imaging lens including a liquid lens, so as to solve the problem of poor imaging quality of optical imaging lenses in the prior art.

[0008] To achieve the above objectives, a first aspect of the present invention provides an optical imaging lens including a liquid lens. The optical imaging lens includes, from the object side to the image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a liquid lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens. The first to ninth lenses each include an object-side surface facing the object side and allowing imaging light to pass therethrough, and an image-side surface facing the image side and allowing the imaging light to pass therethrough.

[0009] The first lens has a positive refractive power, the object-side surface of the first lens is a convex surface, and the image-side surface of the first lens is a concave surface, a convex surface, or a flat surface;

[0010] The second lens has a negative refractive power, the object-side surface of the second lens is convex, and the image-side surface of the second lens is concave;

[0011] The third lens has a negative refractive power, the object side surface of the third lens is concave, and the image side surface of the third lens is concave;

[0012] The fourth lens has a positive refractive power, the object side surface of the fourth lens is concave, and the image side surface of the fourth lens is convex;

[0013] The fifth lens has a positive refractive power, the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a concave surface, a convex surface or a flat surface;

[0014] The sixth lens has a positive refractive power, the object side surface of the sixth lens is a concave surface, a convex surface or a flat surface, and the image side surface of the sixth lens is a convex surface;

[0015] The seventh lens element has a negative refractive power, the object side surface of the seventh lens element is concave, and the image side surface of the seventh lens element is concave, convex or flat;

[0016] The eighth lens has a positive refractive power, the object side surface of the eighth lens is concave, convex or flat, and the image side surface of the eighth lens is convex;

[0017] The ninth lens element has a positive refractive power, the object side surface of the ninth lens element is a convex surface, and the image side surface of the ninth lens element is a concave surface, a convex surface or a flat surface;

[0018] The sixth lens and the seventh lens are cemented to each other.

[0019] Preferably, the image-side surface of the first lens is concave;

[0020] The image side surface of the fifth lens is concave;

[0021] The object-side surface of the sixth lens is a plane;

[0022] The image side surface of the seventh lens is concave;

[0023] The image-side surface of the ninth lens is convex.

[0024] Further preferably, the object-side surface of the eighth lens is a concave surface close to a plane or a convex surface close to a plane;

[0025] Furthermore, it also includes an aperture, which is arranged on the liquid lens.

[0026] Furthermore, in the direction from the object side to the image side, the liquid lens includes, in sequence, a first transparent surface layer, a first liquid area, an elastic membrane layer, a second liquid area, and a second transparent surface layer, and the aperture is arranged on the image side surface of the first transparent surface layer, the object side surface of the first transparent surface layer, the image side surface of the second transparent surface layer, or the object side surface of the second transparent surface layer.

[0027] Furthermore, the object distance varies in association with physical parameters of the liquid lens, and the physical parameters of the liquid lens include a curvature radius of the elastic membrane layer, a center thickness of the first liquid area, and a center thickness of the second liquid area.

[0028] Furthermore, when the object distance is 700 mm, the curvature radius of the elastic membrane layer is 54.97 mm, the center thickness of the first liquid area is 0.542 mm, and the center thickness of the second liquid area is 1.928 mm;

[0029] When the object distance is 250 mm, the elastic membrane layer is flat, the center thickness of the first liquid area is 0.578 mm, and the center thickness of the second liquid area is 1.892 mm;

[0030] When the object distance is 150 mm, the curvature radius of the elastic membrane layer is -59.32 mm, the center thickness of the first liquid area is 0.612 mm, and the center thickness of the second liquid area is 1.858 mm.

[0031] Furthermore, the aperture is an ink layer.

[0032] Furthermore, the optical imaging lens meets the following requirements:

[0033] nd1>1.65, where nd1 is the refractive index of the first lens;

[0034] nd2>1.6, where nd2 is the refractive index of the second lens;

[0035] nd3>1.65, where nd3 is the refractive index of the third lens;

[0036] nd4>1.65, where nd4 is the refractive index of the fourth lens element;

[0037] nd5>1.68, where nd5 is the refractive index of the fifth lens element;

[0038] nd6<1.75, where nd6 is the refractive index of the sixth lens element;

[0039] nd7>1.7, where nd7 is the refractive index of the seventh lens element;

[0040] nd8>1.65, where nd8 is the refractive index of the eighth lens;

[0041] nd9>1.65, where nd9 is the refractive index of the ninth lens element.

[0042] Furthermore, the optical imaging lens also meets the following requirements:

[0043] Vd1<45, where Vd1 is the dispersion coefficient of the first lens;

[0044] Vd2>45, where Vd2 is the dispersion coefficient of the second lens;

[0045] Vd3<35, where Vd3 is the dispersion coefficient of the third lens;

[0046] Vd4>35, where Vd4 is the dispersion coefficient of the fourth lens;

[0047] Vd5<32, where Vd5 is the dispersion coefficient of the fifth lens;

[0048] Vd6>45, where Vd6 is the dispersion coefficient of the sixth lens;

[0049] Vd7<35, where Vd7 is the seventh lens dispersion coefficient;

[0050] Vd9<35, where Vd9 is the dispersion coefficient of the ninth lens.

[0051] Furthermore, the optical imaging lens further satisfies: 0.18≤BFL / TTL≤0.25; wherein BFL is the distance from the image side surface of the ninth lens element to the imaging plane on the optical axis, and TTL is the distance from the object side surface of the first lens element to the imaging plane on the optical axis.

[0052] Furthermore, the optical imaging lens also satisfies: 1≤f 后组 / f≤1.5; where f 后组 is the combined focal length of the sixth to ninth lenses, and f is the focal length of the optical imaging lens.

[0053] The optical imaging lens of the present invention, through the integration of a liquid lens, can rapidly adjust its focal length to accommodate objects with different working distances and depths of field requirements. This significantly improves imaging accuracy and speed, particularly in high-speed or precision imaging applications. Furthermore, through the refractive powers and surface curvatures of the first to ninth lenses, as well as the arrangement sequence between the lenses, the light transmission path and imaging quality are optimized, aberrations and distortion are reduced, and thus the lens resolution and imaging clarity are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 is a schematic structural diagram of an optical imaging lens in one embodiment;

[0055] Figure 2 Schematic diagram of the structure of a liquid lens in one embodiment;

[0056] Figure 3 is a diagram of the light spot focusing points of the optical imaging lens when the object distance is 150 mm in one embodiment;

[0057] Figure 4 2. A diagram showing the focal points of the optical imaging lens when the object distance is 250 mm in one embodiment;

[0058] Figure 5 FIG1 is a diagram of the light spot focusing points of the optical imaging lens when the object distance is 700 mm in one embodiment;

[0059] Figure 6 1. (a) astigmatism and (b) distortion curves of an optical imaging lens when the object distance is 150 mm in one embodiment;

[0060] Figure 7 1. (a) astigmatism and (b) distortion curves of an optical imaging lens when the object distance is 250 mm in one embodiment;

[0061] Figure 8 1 and 2 are (a) astigmatism and (b) distortion curves of an optical imaging lens when the object distance is 700 mm in one embodiment.

[0062] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0063] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which this invention belongs. The terms used in the specification of the application are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the accompanying drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of the present invention and the accompanying drawings are used to distinguish different objects, not to describe a specific order.

[0064] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0065] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0066] The lens mentioned in the embodiments of the present invention, if it has a positive refractive power (or negative refractive power), means that the paraxial refractive power calculated according to Gaussian optical theory is positive (or negative). The object side (or image side) of the lens specifically refers to the specific area on the lens surface where the imaging light penetrates. The concave and convex shape of the lens surface is determined according to the conventional judgment method of those skilled in the art, that is, it is determined based on the positive and negative signs of the radius of curvature (abbreviated as R value). R value is widely used in optical design software, such as Zemax or CodeV, and is commonly found in lens datasheets.

[0067] Specifically, for the object side, when the R value is positive, the object side is determined to be convex; when the R value is negative, the object side is determined to be concave. Correspondingly, for the image side, when the R value is positive, the image side is determined to be concave; when the R value is negative, the image side is determined to be convex.

[0068] Reference Figure 1 One embodiment of the present invention discloses an optical imaging lens including a liquid lens. The optical imaging lens includes, from the object side to the image side, a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a liquid lens 10, a sixth lens 6, a seventh lens 7, an eighth lens 8, and a ninth lens 9. The first lens 1 to the ninth lens 9 each include an object-side surface facing the object side and allowing imaging light to pass therethrough, and an image-side surface facing the image side and allowing the imaging light to pass therethrough.

[0069] The first lens 1 has a positive refractive power, the object-side surface 11 of the first lens is a convex surface, and the image-side surface 12 of the first lens is a concave surface, a convex surface or a flat surface;

[0070] The second lens 2 has a negative refractive power, the object-side surface 21 of the second lens is a convex surface, and the image-side surface 22 of the second lens is a concave surface;

[0071] The third lens 3 has a negative refractive power, the object side surface 31 of the third lens is a concave surface, and the image side surface 32 of the third lens is a concave surface;

[0072] The fourth lens element 4 has a positive refractive power, an object-side surface 41 of the fourth lens element is a concave surface, and an image-side surface 42 of the fourth lens element is a convex surface;

[0073] The fifth lens element 5 has a positive refractive power, the object-side surface 51 of the fifth lens element is a convex surface, and the image-side surface 52 of the fifth lens element is a concave surface, a convex surface or a flat surface;

[0074] The sixth lens element 6 has a positive refractive power, the object-side surface 61 of the sixth lens element is a concave surface, a convex surface or a flat surface, and the image-side surface 62 of the sixth lens element is a convex surface;

[0075] The seventh lens element 7 has a negative refractive power, the object-side surface 71 of the seventh lens element is concave, and the image-side surface 72 of the seventh lens element is concave, convex or flat;

[0076] The eighth lens element 8 has a positive refractive power, the object-side surface 81 of the eighth lens element is a concave surface, a convex surface or a flat surface, and the image-side surface 82 of the eighth lens element is a convex surface;

[0077] The ninth lens element 9 has a positive refractive power, the object-side surface 91 of the ninth lens element is a convex surface, and the image-side surface 92 of the ninth lens element is a concave surface, a convex surface or a flat surface;

[0078] The sixth lens 6 and the seventh lens 7 are glued to each other.

[0079] The above-mentioned optical imaging lens further includes a filter 01 and an image sensor 02 arranged on the image side of the ninth lens.

[0080] By integrating the liquid lens 10, the optical lens of the present invention can rapidly adjust its focal length to accommodate objects with varying working distances and depths of field requirements. This significantly improves imaging accuracy and speed, particularly in high-speed or precision imaging applications. Furthermore, the refractive powers, surface curvatures, and arrangement of the first through ninth lenses optimize the light transmission path and image quality, reducing aberrations and distortion, thereby enhancing the lens' resolution and image clarity.

[0081] This invention uses a liquid lens for focusing, without changing the optical or mechanical back focus of the lens. By using a voltage to drive the curvature radius of the liquid lens, the image can be refocused onto the optically sensitive surface of the camera detector for objects at different distances. The lack of a mechanical structure allows for rapid focusing and a long service life, capable of hundreds of millions of cycles.

[0082] As a preferred embodiment of the present invention, the image-side surface 12 of the first lens is a concave surface; the image-side surface 52 of the fifth lens is a concave surface; the object-side surface 61 of the sixth lens is a plane; the image-side surface 72 of the seventh lens is a concave surface; the object-side surface 81 of the eighth lens is a concave surface close to a plane or a convex surface close to a plane; and the image-side surface 92 of the ninth lens is a convex surface.

[0083] Reference Figure 2 In a specific embodiment, the optical lens 10 further includes a diaphragm 101, which is disposed on the liquid lens 10. The liquid lens 10 is located between the fifth lens 5 and the sixth lens 6, that is, in the middle of the entire optical lens. The diaphragm 101 is disposed on the liquid lens 10 to achieve a central diaphragm, which can maximize the use of the liquid lens aperture, increase the light transmission effect of the optical lens, ensure its compact structure, and reduce the total length. The liquid lens 10 used in the present invention can be obtained by selecting parameters from liquid lenses in the prior art. Its principle adopts the voltage control principle of a general liquid lens, which will not be elaborated in the present invention.

[0084] In one specific embodiment, the liquid lens 10 includes, in order from the object side to the image side, a first transparent surface layer 102, a first liquid area 103, an elastic film layer 104, a second liquid area 105, and a second transparent surface layer 106. The aperture 101 is disposed on the image side, object side, image side, or object side of the first transparent surface layer 102, the first transparent surface layer 102, the second transparent surface layer 106. As a more preferred embodiment, the aperture 101 is disposed on the object side or the image side of the second transparent surface layer 106, thereby reducing the aperture of the liquid area and improving the utilization rate of the liquid in the first and second liquid areas 103, 105. The first and second transparent surface layers 102, 106 are preferably made of glass. The liquids in the first and second liquid areas 103, 105 are selected from an oily solution and an aqueous solution, respectively. The elastic film layer 104 is made of a highly elastic and transparent material, such as silicone rubber or a specially formulated polymer film.

[0085] In a specific embodiment, the object distance varies in association with physical parameters of the liquid lens, where the physical parameters of the liquid lens include a curvature radius of the elastic membrane layer, a center thickness of the first liquid area, and a center thickness of the second liquid area.

[0086] In one embodiment, the liquid lens has the following characteristics:

[0087] When the object distance is 700 mm, the curvature radius of the elastic membrane layer is 54.97 mm, the center thickness of the first liquid area is 0.542 mm, and the center thickness of the second liquid area is 1.928 mm;

[0088] When the object distance is 250 mm, the elastic membrane layer is flat, the center thickness of the first liquid area is 0.578 mm, and the center thickness of the second liquid area is 1.892 mm;

[0089] When the object distance is 150 mm, the curvature radius of the elastic membrane layer is -59.32 mm, the center thickness of the first liquid area is 0.612 mm, and the center thickness of the second liquid area is 1.858 mm.

[0090] In a specific embodiment, the aperture is an ink layer.

[0091] The ink-layer diaphragm design simplifies the structure of optical imaging lenses, reducing the mechanical components and assembly processes required for traditional diaphragms, thereby lowering the manufacturing cost and complexity of the lens. Furthermore, the ink-layer diaphragm offers higher manufacturing precision, enabling finer control of the diaphragm pattern and opening size, thereby improving the imaging quality and performance of the lens.

[0092] In a specific embodiment, the optical imaging lens satisfies:

[0093] nd1>1.65, where nd1 is the refractive index of the first lens;

[0094] nd2>1.6, where nd2 is the refractive index of the second lens;

[0095] nd3>1.65, where nd3 is the refractive index of the third lens;

[0096] nd4>1.65, where nd4 is the refractive index of the fourth lens element;

[0097] nd5>1.68, where nd5 is the refractive index of the fifth lens element;

[0098] nd6<1.75, where nd6 is the refractive index of the sixth lens element;

[0099] nd7>1.7, where nd7 is the refractive index of the seventh lens element;

[0100] nd8>1.65, where nd8 is the refractive index of the eighth lens;

[0101] nd9>1.65, where nd9 is the refractive index of the ninth lens element.

[0102] In a specific embodiment, the optical imaging lens further meets the following requirements:

[0103] Vd1<45, where Vd1 is the dispersion coefficient of the first lens;

[0104] Vd2>45, where Vd2 is the dispersion coefficient of the second lens;

[0105] Vd3<35, where Vd3 is the dispersion coefficient of the third lens;

[0106] Vd4>35, where Vd4 is the dispersion coefficient of the fourth lens;

[0107] Vd5<32, where Vd5 is the dispersion coefficient of the fifth lens;

[0108] Vd6>45, where Vd6 is the dispersion coefficient of the sixth lens;

[0109] Vd7<35, where Vd7 is the seventh lens dispersion coefficient;

[0110] Vd9<35, where Vd9 is the dispersion coefficient of the ninth lens.

[0111] In a specific embodiment, the optical imaging lens further satisfies: 0.18≤BFL / TTL≤0.25; where BFL is the distance from the image side surface of the ninth lens element to the imaging plane on the optical axis, and TTL is the distance from the object side surface of the first lens element to the imaging plane on the optical axis.

[0112] In the present invention, the optical imaging lens within the above ratio range can maintain good aberration correction capabilities, ensuring imaging clarity and contrast. The lens can also minimize the size while ensuring imaging quality.

[0113] In a specific embodiment, the optical imaging lens further satisfies: 1≤f 后组 / f≤1.5; where f 后组 is the combined focal length of the sixth to ninth lenses, and f is the focal length of the optical imaging lens.

[0114] By controlling the focal length of the rear lens group within this range, aberrations, particularly field curvature and distortion, are minimized, maintaining good image quality at wider field angles. Furthermore, within this range, the focal length of the rear lens group is neither too long, making the lens excessively long, nor too short, making aberration correction difficult, contributing to a compact optical lens design.

[0115] The optical imaging lens including the liquid lens of the present invention is described in detail below with reference to specific embodiments.

[0116] Example 1

[0117] like Figure 1 As shown, an optical imaging lens including a liquid lens comprises, from the object side to the image side, a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a liquid lens 10, a sixth lens 6, a seventh lens 7, an eighth lens 8, and a ninth lens 9; the first lens 1 to the ninth lens 9 each include an object-side surface facing the object side and allowing imaging light to pass therethrough, and an image-side surface facing the image side and allowing the imaging light to pass therethrough;

[0118] The first lens 1 has a positive refractive power, the object-side surface 11 of the first lens is a convex surface, and the image-side surface 12 of the first lens is a concave surface;

[0119] The second lens 2 has a negative refractive power, the object-side surface 21 of the second lens is a convex surface, and the image-side surface 22 of the second lens is a concave surface;

[0120] The third lens 3 has a negative refractive power, the object side surface 31 of the third lens is a concave surface, and the image side surface 32 of the third lens is a concave surface;

[0121] The fourth lens element 4 has a positive refractive power, an object-side surface 41 of the fourth lens element is a concave surface, and an image-side surface 42 of the fourth lens element is a convex surface;

[0122] The fifth lens element 5 has a positive refractive power, an object-side surface 51 of the fifth lens element is a convex surface, and an image-side surface 52 of the fifth lens element is a concave surface;

[0123] The sixth lens element 6 has a positive refractive power, the object-side surface 61 of the sixth lens element is a flat surface, and the image-side surface 62 of the sixth lens element is a convex surface;

[0124] The seventh lens element 7 has a negative refractive power, the object-side surface 71 of the seventh lens element is concave, and the image-side surface 72 of the seventh lens element is concave;

[0125] The eighth lens element 8 has a positive refractive power, the object-side surface 81 of the eighth lens element is concave, and the image-side surface 82 of the eighth lens element is convex;

[0126] The ninth lens element 9 has a positive refractive power, an object-side surface 91 of the ninth lens element is a convex surface, and an image-side surface 92 of the ninth lens element is a convex surface;

[0127] The sixth lens 6 and the seventh lens 7 are glued to each other.

[0128] The detailed optical data of this embodiment 1 is shown in Table 1.

[0129] Table 1 Optical data list of Example 1

[0130]

[0131]

[0132] The values of D1 and D2 of the liquid lens 10 are shown in Table 2.

[0133] Table 2 Liquid lens parameters corresponding to different object distances

[0134]

[0135] The focus spot sizes of different working object distances (150mm, 250mm, 700mm) in this specific embodiment are detailed in Figure 3-Figure 5 , it can be seen that the focused spot size is small and the imaging clarity of the optical imaging lens is high.

[0136] The astigmatism and distortion curves for different working object distances (150mm, 250mm, 700mm) are detailed in Figure 6-Figure 8 It can be seen that the astigmatism and distortion of the optical imaging lens of this embodiment are relatively small, and the distortion amount is less than 1.4%.

[0137] In this specific embodiment, the BFL / TTL of the optical imaging lens is 0.22, f 后组 / f=1.29.

[0138] Obviously, the embodiments described above are only some embodiments of the present invention, rather than all embodiments. The preferred embodiments of the present invention are given in the accompanying drawings, but they do not limit the patent scope of the present invention. The present invention can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. Although the present invention has been described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions described in the aforementioned specific embodiments, or to make equivalent replacements for some of the technical features therein. Any equivalent structure made using the contents of the present invention specification and drawings, directly or indirectly used in other related technical fields, is also within the scope of patent protection of the present invention.

Claims

1. An optical imaging lens comprising a liquid lens, characterized in that: The optical imaging lens is composed of, from the object side to the image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a liquid lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens; the first to ninth lenses each include an object-side surface facing the object side and allowing imaging light to pass therethrough, and an image-side surface facing the image side and allowing the imaging light to pass therethrough; The first lens has a positive refractive power, the object-side surface of the first lens is a convex surface, and the image-side surface of the first lens is a concave surface, a convex surface, or a flat surface; The second lens has a negative refractive power, the object-side surface of the second lens is convex, and the image-side surface of the second lens is concave; The third lens has a negative refractive power, the object side surface of the third lens is concave, and the image side surface of the third lens is concave; The fourth lens has a positive refractive power, the object side surface of the fourth lens is concave, and the image side surface of the fourth lens is convex; The fifth lens has a positive refractive power, the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a concave surface, a convex surface or a flat surface; The sixth lens has a positive refractive power, the object side surface of the sixth lens is a concave surface, a convex surface or a flat surface, and the image side surface of the sixth lens is a convex surface; The seventh lens element has a negative refractive power, the object side surface of the seventh lens element is concave, and the image side surface of the seventh lens element is concave, convex or flat; The eighth lens has a positive refractive power, the object side surface of the eighth lens is concave, convex or flat, and the image side surface of the eighth lens is convex; The ninth lens element has a positive refractive power, the object side surface of the ninth lens element is a convex surface, and the image side surface of the ninth lens element is a concave surface, a convex surface or a flat surface; The sixth lens and the seventh lens are cemented to each other; The optical imaging lens further satisfies the following: 0.18≤BFL / TTL≤0.25; wherein BFL is the distance from the image side surface of the ninth lens element to the imaging surface on the optical axis, and TTL is the distance from the object side surface of the first lens element to the imaging surface on the optical axis.

2. The optical imaging lens comprising a liquid lens according to claim 1, wherein: It also includes an aperture, which is arranged on the liquid lens.

3. The optical imaging lens comprising a liquid lens according to claim 2, wherein: In the direction from the object side to the image side, the liquid lens includes a first transparent surface layer, a first liquid area, an elastic membrane layer, a second liquid area, and a second transparent surface layer in sequence, and the aperture is arranged on the image side surface of the first transparent surface layer, the object side surface of the first transparent surface layer, the image side surface of the second transparent surface layer, or the object side surface of the second transparent surface layer.

4. The optical imaging lens comprising a liquid lens according to claim 3, wherein: The object distance varies in association with physical parameters of the liquid lens, where the physical parameters of the liquid lens include a curvature radius of the elastic membrane layer, a center thickness of the first liquid area, and a center thickness of the second liquid area.

5. The optical imaging lens comprising a liquid lens according to claim 4, wherein: When the object distance is 700 mm, the curvature radius of the elastic membrane layer is 54.97 mm, the center thickness of the first liquid area is 0.542 mm, and the center thickness of the second liquid area is 1.928 mm; When the object distance is 250 mm, the elastic membrane layer is flat, the center thickness of the first liquid area is 0.578 mm, and the center thickness of the second liquid area is 1.892 mm; When the object distance is 150 mm, the curvature radius of the elastic membrane layer is -59.32 mm, the center thickness of the first liquid area is 0.612 mm, and the center thickness of the second liquid area is 1.858 mm.

6. The optical imaging lens comprising a liquid lens according to claim 2, wherein: The aperture is an ink layer.

7. The optical imaging lens comprising a liquid lens according to claim 1, wherein: The optical imaging lens meets the following requirements: nd1>1.65, where nd1 is the refractive index of the first lens; nd2>1.6, where nd2 is the refractive index of the second lens; nd3>1.65, where nd3 is the refractive index of the third lens; nd4>1.65, where nd4 is the refractive index of the fourth lens element; nd5>1.68, where nd5 is the refractive index of the fifth lens element; nd6<1.75, where nd6 is the refractive index of the sixth lens element; nd7>1.7, where nd7 is the refractive index of the seventh lens element; nd8>1.65, where nd8 is the refractive index of the eighth lens; nd9>1.65, where nd9 is the refractive index of the ninth lens element.

8. The optical imaging lens comprising a liquid lens according to claim 7, wherein: The optical imaging lens further meets the following requirements: Vd1<45, where Vd1 is the dispersion coefficient of the first lens; Vd2>45, where Vd2 is the dispersion coefficient of the second lens; Vd3<35, where Vd3 is the dispersion coefficient of the third lens; Vd4>35, where Vd4 is the dispersion coefficient of the fourth lens; Vd5<32, where Vd5 is the dispersion coefficient of the fifth lens; Vd6>45, where Vd6 is the dispersion coefficient of the sixth lens; Vd7<35, where Vd7 is the seventh lens dispersion coefficient; Vd9<35, where Vd9 is the dispersion coefficient of the ninth lens.

9. The optical imaging lens comprising a liquid lens according to claim 1, wherein: The optical imaging lens also satisfies: 1≤f 后组 / f≤1.5; where f 后组 is the combined focal length of the sixth to ninth lenses, and f is the focal length of the optical imaging lens.

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