An imaging lens

Abstract

The application relates to an imaging lens, comprising a lens barrel, a lens set and a plurality of spacer elements assembled in the lens barrel, the lens set comprising a first lens, a second lens, a third lens and a fourth lens, the plurality of spacer elements comprising a first spacer element arranged between the first lens and the second lens and abutting an image side surface of the first lens, a second spacer element arranged between the second lens and the third lens and abutting an image side surface of the second lens, and a third spacer element arranged between the third lens and the fourth lens and abutting an image side surface of the third lens, the second lens being a super lens and the image side surface of the second lens being a super surface, and the imaging lens further satisfying 8.8 < L / CT2 < 9.8, 7.3 < (D1m-d1m) / T12 < 11.8 and 1.85 < (d2s+d2m) / DR22 < 2.25.

Description

Technical Field

[0001] This invention relates to the field of optical device technology, and in particular to an imaging lens suitable for mobile devices. Background Technology

[0002] Imaging lenses are a crucial component of optical products. With the rapid development of mobile devices, users have increasingly higher demands for imaging lenses, seeking high-definition and high-contrast imaging effects approaching those of professional cameras. However, in actual shooting, lens stray light significantly impacts the image quality of mobile phones, becoming one of the key factors restricting the improvement of mobile phone photography performance.

[0003] Currently, the industry has conducted extensive research and practice to address the issue of stray light in mobile phone lenses. This includes technological advancements such as coating multiple layers of anti-reflective film on the lens surface to reduce light reflectivity and minimize stray light caused by internal reflections; and algorithmic approaches, with some mobile phone manufacturers utilizing AI image recognition technology to automatically detect and correct stray light areas. While these technologies alleviate the stray light problem to some extent, they still have significant shortcomings, such as increased cost, algorithm complexity, and processing time. Therefore, controlling stray light during the lens design phase is crucial. Summary of the Invention

[0004] The imaging lens provided in this application includes a lens barrel and a lens group and a plurality of spacers mounted within the lens barrel; the lens group, from the object side to the image side, sequentially includes: a first lens with positive optical power, a second lens with positive optical power, a third lens with negative optical power, and a fourth lens with negative optical power; the plurality of spacers, from the object side to the image side, sequentially includes: a first spacer, a second spacer, and a third spacer, wherein the first spacer is located between the first lens and the second lens and abuts against the image side of the first lens, the second spacer is located between the second lens and the third lens and abuts against the image side of the second lens, and the third spacer is located between the third lens and the fourth lens and abuts against the image side of the third lens; the second lens... The lens is a superlens, and the image-side surface of the second lens is a metasurface; the imaging lens satisfies: 8.8 < L / CT2 < 9.8, 7.3 < (D1m - d1m) / T12 < 11.8 and 1.85 < (d2s + d2m) / DR22 < 2.25, where L is the maximum height from the object-side surface of the lens barrel to the image-side surface of the lens barrel, CT2 is the center thickness of the second lens on the optical axis, D1m is the outer diameter of the image-side surface of the first spacer element, d1m is the inner diameter of the image-side surface of the first spacer element, T12 is the air gap between the first lens and the second lens on the optical axis, d2s is the inner diameter of the object-side surface of the second spacer element, d2m is the inner diameter of the image-side surface of the second spacer element, and DR22 is the effective diameter of the image-side surface of the second lens.

[0005] In some embodiments of this application, the metasurface includes a substrate and microstructures formed on the substrate, wherein the surface of the substrate is planar and the substrate is made of glass.

[0006] In some embodiments of this application, the imaging lens also satisfies: 3.30≤f / EP13≤3.84, where f is the system focal length of the imaging lens and EP13 is the distance along the optical axis from the object side of the first spacer element to the image side of the third spacer element.

[0007] In some embodiments of this application, the imaging lens also satisfies: 0.85 < f2 / (D2s+D2m) < 1.55, where f2 is the effective focal length of the second lens, D2s is the outer diameter of the object side of the second spacer element, and D2m is the outer diameter of the image side of the second spacer element.

[0008] In some embodiments of this application, the imaging lens also satisfies: 6.55 < f1 / EP01 < 7.7, where f1 is the effective focal length of the first lens, and EP01 is the distance along the optical axis from the side of the lens barrel to the side of the first spacer element.

[0009] In some embodiments of this application, the imaging lens also satisfies: 1.05 < (D0s - d0s) / R1 < 1.6, where D0s is the outer diameter of the side surface of the lens barrel, d0s is the inner diameter of the side surface of the lens barrel, and R1 is the radius of curvature of the side surface of the first lens.

[0010] In some embodiments of this application, the imaging lens also satisfies: 4.15≤d3s / T34≤6.88, where d3s is the inner diameter of the side of the third spacer element and T34 is the air gap between the third lens and the fourth lens on the optical axis.

[0011] In some embodiments of this application, the imaging lens also satisfies: 2.0 < (EP23 + CP3) / CT3 < 2.35, where EP23 is the distance from the image side of the second spacer element to the object side of the third spacer element along the optical axis, CP3 is the maximum thickness of the third spacer element along the optical axis, and CT3 is the center thickness of the third lens on the optical axis.

[0012] In some embodiments of this application, the imaging lens also satisfies: 1.9 < D3s / MD < 3.2, where D3s is the outer diameter of the object side of the third spacer element, and MD is the on-axis distance from the image side of the second lens to the image side of the fourth lens.

[0013] In some embodiments of this application, the imaging lens also satisfies: 1.05 < R2 / d1s < 1.5, where R2 is the radius of curvature of the image side of the first lens, and d1s is the inner diameter of the object side of the first spacer element.

[0014] In some embodiments of this application, the imaging lens also satisfies: 1.4 < D0m / D3m < 1.85, where D0m is the outer diameter of the image side of the lens barrel and D3m is the outer diameter of the image side of the third spacer element.

[0015] In some embodiments of this application, the imaging lens also satisfies: 5.34≤(D1s-d1s) / EP12≤7.30, where D1s is the outer diameter of the side surface of the first spacer element, d1s is the inner diameter of the side surface of the first spacer element, and EP12 is the distance from the image side surface of the first spacer element to the side surface of the second spacer element along the optical axis.

[0016] In some embodiments of this application, the imaging lens also satisfies: 3.05mm < R3 × (CP1 / CP2) < 4.45mm, where R3 is the radius of curvature of the side surface of the second lens, CP1 is the maximum thickness of the first spacer element along the optical axis, and CP2 is the maximum thickness of the second spacer element along the optical axis.

[0017] In some embodiments of this application, the imaging lens also satisfies: 4.35 < d0m / ∑CT < 4.75, where d0m is the inner diameter of the image side of the lens barrel, and ∑CT is the sum of the center thicknesses of the first lens, the second lens, the third lens, and the fourth lens on the optical axis.

[0018] In some embodiments of this application, the imaging lens also satisfies: -4.05 < f4 / d3m < -2.35, where f4 is the effective focal length of the fourth lens and d3m is the inner diameter of the image side of the third spacer element.

[0019] In summary, the imaging lens provided in this application, under the premise of satisfying 8.8 < L / CT2 < 9.8, aims to ensure the manufacturability, strength, and assembly stability of the second lens. Furthermore, due to the limitations of the small head size, the outer diameter of the second lens is relatively small. However, when light enters the second lens, it undergoes reflection, scattering, or diffraction, generating stray light. This stray light affects image quality, especially under high brightness or strong light source environments. By controlling the conditions 7.3 < (D1m - d1m) / T12 < 11.8 and 1.85 < (d2s + d2m) / DR22 < 2.25, the dimensions of the first and second spacer elements are ensured. This prevents internal reflection stray light generated by the edge of the second lens reflecting onto the second lens structure, and also effectively blocks stray light after reflection, thereby improving the stray light problem generated by the second lens itself and enhancing image quality. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structural parameters of an imaging lens according to one embodiment of this application;

[0021] Figure 2 yes Figure 1 The diagram shows other structural parameters of the imaging lens.

[0022] Figure 3 This is a schematic diagram of the imaging lens according to Embodiment 1 of this application;

[0023] Figure 4 This is a schematic diagram of the imaging lens according to Embodiment 2 of this application;

[0024] Figure 5 This is a schematic diagram of the imaging lens according to Embodiment 3 of this application;

[0025] Figure 6A A schematic diagram of the on-axis chromatic aberration curves of the imaging lenses according to the above-described Embodiment 1, Embodiment 2 and Embodiment 3 of this application is shown.

[0026] Figure 6BA schematic diagram of the astigmatism curves of the imaging lenses according to the above-described Embodiment 1, Embodiment 2 and Embodiment 3 of this application is shown.

[0027] Figure 6C The diagram shows the distortion curves of the imaging lenses according to Embodiment 1, Embodiment 2 and Embodiment 3 of this application.

[0028] Figure 7 This is a schematic diagram of the imaging lens according to Embodiment 4 of this application;

[0029] Figure 8 This is a schematic diagram of the imaging lens according to Embodiment 5 of this application;

[0030] Figure 9 This is a schematic diagram of the imaging lens according to Embodiment Six of this application;

[0031] Figure 10A A schematic diagram of the on-axis chromatic aberration curves of the imaging lenses according to Embodiments 4, 5 and 6 of this application is shown.

[0032] Figure 10B A schematic diagram of the astigmatism curves of the imaging lenses according to Embodiments 4, 5 and 6 of this application is shown.

[0033] Figure 10C A schematic diagram of the distortion curves of the imaging lenses according to Embodiments 4, 5 and 6 of this application is shown.

[0034] Figure 11 This is a schematic diagram of the imaging lens according to Embodiment Seven of this application;

[0035] Figure 12 This is a schematic diagram of the imaging lens according to Embodiment 8 of this application;

[0036] Figure 13 This is a schematic diagram of the imaging lens according to Embodiment Nine of this application;

[0037] Figure 14A A schematic diagram of the on-axis chromatic aberration curve of the imaging lens according to Embodiment 7, Embodiment 8 and Embodiment 9 of this application is shown.

[0038] Figure 14B A schematic diagram of the astigmatism curves of the imaging lenses according to Embodiments 7, 8 and 9 of this application is shown.

[0039] Figure 14C A schematic diagram of the distortion curves of the imaging lenses according to Embodiments 7, 8 and 9 of this application is shown.

[0040] Figure 15 The image spot pattern of the imaging lens is shown when (D1m-d1m) / T12=8.6 and (d2s+d2m) / DR22=2.03.

[0041] Figure 16 The image spot pattern of the imaging lens is shown when (D1m-d1m) / T12=5.2 and (d2s+d2m) / DR22=0.81.

[0042] Figure 17 The image spot pattern of the imaging lens is shown when (D1m-d1m) / T12=13.8 and (d2s+d2m) / DR22=3.6.

[0043] Figure label:

[0044] E1, First lens; E2, Second lens; E3, Third lens; E4, Fourth lens; P0, Lens tube; P1, First spacer element; P2, Second spacer element; P3, Third spacer element. Detailed Implementation

[0045] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0046] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0047] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0048] In this paper, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface shape in the paraxial region can be determined according to methods commonly used in the art, such as using the sign of the R value (R refers to the radius of curvature of the paraxial region) to determine concavity or convexity. In this paper, the surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens. For the object-side surface, when the R value is positive, it is determined to be convex, and when the R value is negative, it is determined to be concave; for the image-side surface, when the R value is positive, it is determined to be concave, and when the R value is negative, it is determined to be convex.

[0049] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0050] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having a meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formalized sense, unless expressly so specified herein.

[0051] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other. The following embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this application. It should be pointed out that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0052] According to one aspect of this application, such as Figure 1 and Figure 2As shown, one embodiment of this application proposes an imaging lens, which may include a lens barrel P0 and a lens group and a plurality of spacers mounted within the lens barrel P0; the lens group, from the object side to the image side, sequentially includes: a first lens E1 with positive optical power, a second lens E2 with positive optical power, a third lens E3 with negative optical power, and a fourth lens E4 with negative optical power; the plurality of spacers, from the object side to the image side, sequentially include: a first spacer P1, a second spacer P2, and a third spacer P3, wherein the first spacer P1 is located between the first lens E1 and the second lens E2 and abuts against the image side of the first lens E1, the second spacer P2 is located between the second lens E2 and the third lens E3 and abuts against the image side of the second lens E2, and the third spacer P3 is located between the third lens E3 and the fourth lens E4 and abuts against the image side of the first lens E1. The image-side surface of the third lens E3 is described; the second lens E2 is a superlens, and the image-side surface of the second lens E2 is a metasurface; the imaging lens satisfies: 8.8 < L / CT2 < 9.8, 7.3 < (D1m - d1m) / T12 < 11.8 and 1.85 < (d2s + d2m) / DR22 < 2.25, where L is the maximum height from the object-side surface of the lens barrel P0 to the image-side surface of the lens barrel P0, CT2 is the center thickness of the second lens E2 on the optical axis, D1m is the outer diameter of the image-side surface of the first spacer element P1, d1m is the inner diameter of the image-side surface of the first spacer element P1, T12 is the air gap between the first lens E1 and the second lens E2 on the optical axis, d2s is the inner diameter of the object-side surface of the second spacer element P2, d2m is the inner diameter of the image-side surface of the second spacer element P2, and DR22 is the effective diameter of the image-side surface of the second lens E2.

[0053] In summary, the imaging lens provided in this application, under the premise of satisfying 8.8 < L / CT2 < 9.8, aims to ensure the manufacturability, strength, and assembly stability of the second lens E2. Furthermore, due to the limitations of the small head size, the outer diameter of the second lens E2 is relatively small. However, when light enters the second lens E2, it undergoes reflection, scattering, or diffraction, generating stray light. This stray light affects image quality, especially under high brightness or strong light source environments. By controlling the conditions 7.3 < (D1m - d1m) / T12 < 11.8 and 1.85 < (d2s + d2m) / DR22 < 2.25, the dimensions of the first spacer element P1 and the second spacer element P2 are ensured. This prevents internal reflection stray light generated by the edge of the object side of the second lens E2 reflecting onto the structural part of the second lens E2, and also effectively blocks stray light after reflection, thereby improving the stray light problem generated by the second lens E2 itself and enhancing image quality.

[0054] For example, Figure 15The image shows the spot pattern of the imaging lens when (D1m-d1m) / T12=8.6 and (d2s+d2m) / DR22=2.03. It is easy to see from the figure that when the imaging lens is within the range of 7.3<(D1m-d1m) / T12<11.8 and 1.85<(d2s+d2m) / DR22<2.25, the optical path of the imaging lens is normal, no stray light is generated at the position of the reflecting structure, and the imaging quality is better. Figure 16 The image shows the spot pattern of the imaging lens when (D1m-d1m) / T12=5.2 and (d2s+d2m) / DR22=0.81. When the conditions (D1m-d1m) / T12 and (d2s+d2m) / DR22 satisfied by the imaging lens exceed their lower limits, stray light exists in the center of the light source in the image. The light is reflected from the object side edge of the first spacer element P1 and the second lens E2 to the structural part and undergoes multiple reflections, forming a large area of ​​haze, which affects the image quality. Figure 17 The image shows the spot pattern when the imaging lens satisfies (D1m-d1m) / T12=13.8 and (d2s+d2m) / DR22=3.6. When the conditions (D1m-d1m) / T12 and (d2s+d2m) / DR22 satisfied by the imaging lens exceed their upper limits, arc-shaped stray light appears below the light source in the image. This is because the light is reflected multiple times from the second lens E2 and exits through the edge of the second spacer element P2, forming a corner arc-shaped phenomenon, which affects the image quality.

[0055] According to some embodiments of this application, the metasurface includes a substrate and microstructures formed on the substrate, wherein the surface of the substrate is planar and the substrate is made of glass. In this way, using planar glass as the substrate of the metalens provides a stable support platform for microstructure fabrication, ensuring consistency and precision in its fabrication, thereby achieving precise control of the optical phase.

[0056] According to some embodiments of this application, the imaging lens also satisfies: 3.30 ≤ f / EP13 ≤ 3.84, where f is the system focal length of the imaging lens, and EP13 is the distance along the optical axis from the object-side surface of the first spacer element P1 to the image-side surface of the third spacer element P3. By reasonably controlling the ratio of the system focal length of the imaging lens to the distance along the optical axis from the object-side surface of the first spacer element P1 to the image-side surface of the third spacer element P3, it is helpful to control the image height and field of view, while ensuring the assembly stability of the optical system.

[0057] According to some embodiments of this application, the imaging lens also satisfies: 0.85 < f2 / (D2s+D2m) < 1.55, where f2 is the effective focal length of the second lens E2, D2s is the outer diameter of the object-side surface of the second spacer element P2, and D2m is the outer diameter of the image-side surface of the second spacer element P2. By reasonably controlling the ratio of the effective focal length of the second lens E2 to the outer diameter of the object-side surface of the second spacer element P2 and the outer diameter of the image-side surface of the second spacer element P2, the aberrations of the optical system can be reduced, and the temperature drift can be decreased. When the effective focal length of the second lens E2 is constant, by limiting the outer diameter of the object-side surface of the second spacer element P2 and the outer diameter of the image-side surface of the second spacer element P2, the waist size of the lens barrel P0 can be controlled, making the structure of the optical system more compact and improving space utilization.

[0058] According to some embodiments of this application, the imaging lens also satisfies: 6.55 < f1 / EP01 < 7.7, where f1 is the effective focal length of the first lens E1, and EP01 is the distance along the optical axis from the object side of the lens barrel P0 to the object side of the first spacer element P1. By reasonably controlling the ratio of the effective focal length of the first lens E1 to the distance along the optical axis from the object side of the lens barrel P0 to the object side of the first spacer element P1, it is beneficial to reasonably distribute the optical power, balance the aberrations of the optical system, and further control the edge thickness of the first lens E1 to ensure its manufacturability.

[0059] According to some embodiments of this application, the imaging lens also satisfies: 1.05 < (D0s - d0s) / R1 < 1.6, where D0s is the outer diameter of the object-side surface of the lens barrel P0, d0s is the inner diameter of the object-side surface of the lens barrel P0, and R1 is the radius of curvature of the object-side surface of the first lens E1. Reasonably controlling the ratio of the outer diameter of the object-side surface of the lens barrel P0, the inner diameter of the object-side surface of the lens barrel P0, and the radius of curvature of the object-side surface of the first lens E1 can, on the one hand, control the size of the lens barrel P0 head, ensuring its miniaturization; on the other hand, it is beneficial to control the shape of the first lens E1, thereby controlling the energy level of the ghosting effect and reducing the risk of ghosting.

[0060] According to some embodiments of this application, the imaging lens also satisfies: 4.15 ≤ d3s / T34 ≤ 6.88, where d3s is the inner diameter of the object side of the third spacer element P3, and T34 is the air gap between the third lens E3 and the fourth lens E4 on the optical axis. By reasonably limiting the ratio of the inner diameter of the object side of the third spacer element P3 to the air gap between the third lens E3 and the fourth lens E4 on the optical axis, the trajectory of light passing through the inner diameter of the third spacer element P3 can be controlled, while simultaneously controlling the amount of light passing through the edges, ensuring the illuminance at the edges, and thus achieving a better image effect with no overall illuminance reversal or sharp drops.

[0061] According to some embodiments of this application, the imaging lens also satisfies: 2.0 < (EP23 + CP3) / CT3 < 2.35, where EP23 is the distance from the image side of the second spacer element P2 to the object side of the third spacer element P3 along the optical axis, CP3 is the maximum thickness of the third spacer element P3 along the optical axis, and CT3 is the center thickness of the third lens E3 along the optical axis. By reasonably controlling the ratio of the distance from the image side of the second spacer element P2 to the object side of the third spacer element P3 along the optical axis, the maximum thickness of the third spacer element P3 along the optical axis, and the center thickness of the third lens E3 along the optical axis, it is possible to ensure that the edge thickness and center thickness of the third lens E3 meet the molding requirements, have good manufacturability, and avoid molding defects; it also makes the fit between the third lens E3 and the fourth lens E4 more stable, and better maintains optical performance when affected by external factors such as vibration and temperature changes.

[0062] According to some embodiments of this application, the imaging lens also satisfies: 1.9 < D3s / MD < 3.2, where D3s is the outer diameter of the object-side surface of the third spacer element P3, and MD is the axial distance from the image-side surface of the second lens E2 to the image-side surface of the fourth lens E4. Reasonably controlling the ratio of the outer diameter of the object-side surface of the third spacer element P3 to the axial distance from the image-side surface of the second lens E2 to the image-side surface of the fourth lens E4 helps control the trajectory of light passing through the third lens E3, ensuring relatively uniform light distribution when passing through the third lens E3, avoiding edge light loss, and preventing the edge portion of the image from being darker than the center portion, thus forming vignetting and affecting the overall image quality.

[0063] According to some embodiments of this application, the imaging lens also satisfies: 1.05 < R2 / d1s < 1.5, where R2 is the radius of curvature of the image-side surface of the first lens E1, and d1s is the inner diameter of the object-side surface of the first spacer element P1. By reasonably controlling the ratio of the radius of curvature of the image-side surface of the first lens E1 to the inner diameter of the object-side surface of the first spacer element P1, the shape of the image-side surface of the first lens E1 can be controlled. This not only reduces the risk of ghosting but also helps control the surface stability during processing. Simultaneously, it can remove stray light from the edges of the optical system, improving image quality.

[0064] According to some embodiments of this application, the imaging lens also satisfies: 1.4 < D0m / D3m < 1.85, where D0m is the outer diameter of the image-side surface of the lens barrel P0, and D3m is the outer diameter of the image-side surface of the third spacer element P3. Reasonably controlling the ratio of the outer diameter of the image-side surface of the lens barrel P0 to the outer diameter of the image-side surface of the third spacer element P3 can, to a certain extent, ensure the wall thickness of the lens barrel P0, which plays an important role in the stability of the lens barrel P0 structure, and at the same time, ensures the manufacturability of the lens barrel P0.

[0065] According to some embodiments of this application, the imaging lens also satisfies: 5.34 ≤ (D1s - d1s) / EP12 ≤ 7.30, where D1s is the outer diameter of the object-side surface of the first spacer element P1, d1s is the inner diameter of the object-side surface of the first spacer element P1, and EP12 is the distance along the optical axis between the image-side surface of the first spacer element P1 and the object-side surface of the second spacer element P2. By reasonably controlling the ratio of the outer diameter of the object-side surface of the first spacer element P1, the inner diameter of the object-side surface of the first spacer element P1, and the distance along the optical axis between the image-side surface of the first spacer element P1 and the object-side surface of the second spacer element P2, stable support can be ensured during the assembly of the second lens E2. Simultaneously, limiting the edge thickness of the second lens E2 can improve its manufacturing feasibility.

[0066] According to some embodiments of this application, the imaging lens also satisfies: 3.05mm < R3 × (CP1 / CP2) < 4.45mm, where R3 is the radius of curvature of the object side surface of the second lens E2, CP1 is the maximum thickness of the first spacer element P1 along the optical axis, and CP2 is the maximum thickness of the second spacer element P2 along the optical axis. Reasonably controlling the ratio of the radius of curvature of the object side surface of the second lens E2 to the maximum thicknesses of the first spacer element P1 and the second spacer element P2 along the optical axis can, on the one hand, control the overall shape of the second lens E2, making the transition light passing through the second lens E2 smoother and reducing lens sensitivity; on the other hand, it plays an important role in the assembly stability between the first lens E1, the second lens E2, and the third lens E3.

[0067] According to some embodiments of this application, the imaging lens also satisfies: 4.35 < d0m / ∑CT < 4.75, where d0m is the inner diameter of the image-side surface of the lens barrel P0, and ∑CT is the sum of the center thicknesses of the first lens E1, the second lens E2, the third lens E3, and the fourth lens E4 along the optical axis. Reasonably controlling the ratio of the inner diameter of the image-side surface of the lens barrel P0 to the sum of the center thicknesses of the first lens E1, the second lens E2, the third lens E3, and the fourth lens E4 along the optical axis helps to make the system structure more compact and reasonable while ensuring optical performance. A large ratio may make the entire lens structure appear too tall and occupy too much space; a small ratio may make the structure too loose, increasing the lateral dimension of the lens and hindering the miniaturization of the device.

[0068] According to some embodiments of this application, the imaging lens also satisfies: -4.05 < f4 / d3m < -2.35, where f4 is the effective focal length of the fourth lens E4, and d3m is the inner diameter of the image-side surface of the third spacer element P3. Reasonably controlling the ratio of the effective focal length of the fourth lens E4 to the inner diameter of the image-side surface of the third spacer element P3 makes the light passing through the fourth lens E4 more stable and can correct aberrations. Under a certain effective focal length of the fourth lens E4, if the inner diameter of the image-side surface of the third spacer element P3 is too large, it will introduce excess light, forming stray light and affecting image quality; if it is too small, it will intercept light, affecting illuminance, causing a sharp drop in illuminance at the edge of the image plane, forming vignetting, and affecting the imaging effect.

[0069] According to another aspect of this application, one embodiment of this application provides an imaging lens, which may include a lens barrel P0 and a lens group and a plurality of spacer elements assembled within the lens barrel P0.

[0070] The lens group, from the object side to the image side, includes, in sequence: a first lens E1 with positive optical power, a second lens E2 with positive optical power, a third lens E3 with negative optical power, and a fourth lens E4 with negative optical power.

[0071] The plurality of spacers, from the object side to the image side, sequentially include: a first spacer P1, a second spacer P2, and a third spacer P3, wherein the first spacer P1 is located between the first lens E1 and the second lens E2 and abuts against the image side of the first lens E1, the second spacer P2 is located between the second lens E2 and the third lens E3 and abuts against the image side of the second lens E2, and the third spacer P3 is located between the third lens E3 and the fourth lens E4 and abuts against the image side of the third lens E3;

[0072] The second lens E2 is a superlens, and the image-side surface of the second lens E2 is a metasurface;

[0073] The imaging lens satisfies the following conditions: 8.8 < L / CT2 < 9.8, 1.05 < R2 / d1s < 1.5, and 1.85 < (d2s + d2m) / DR22 < 2.25, where L is the maximum height from the object side of the lens barrel P0 to the image side of the lens barrel P0, CT2 is the center thickness of the second lens E2 on the optical axis, R2 is the radius of curvature of the image side of the first lens E1, d1s is the inner diameter of the object side of the first spacer element P1, d2s is the inner diameter of the object side of the second spacer element P2, d2m is the inner diameter of the image side of the second spacer element P2, and DR22 is the effective diameter of the image side of the second lens E2.

[0074] It is worth noting that, under the premise of satisfying 8.8 < L / CT2 < 9.8, the imaging lens provided in this application, in order to ensure the manufacturability, strength, and assembly stability of the second lens E2, and due to the limitations of the small head shape size, has a small outer diameter. However, when light enters the second lens E2, it will be reflected, scattered, or diffracted, generating stray light. This stray light will affect the image quality, especially in high-brightness or strong light source environments. By controlling the conditions 1.05 < R2 / d1s < 1.5 and 1.85 < (d2s + d2m) / DR22 < 2.25, on the one hand, the size of the first spacer element P1 and the second spacer element P2 are constrained, preventing the internal reflection stray light generated by the edge of the object side of the second lens E2 reflecting onto the structural parts of the first lens E1 and the second lens E2, and also effectively blocking the stray light after reflection. On the other hand, the shape of the first lens E1 and the second lens E2 is constrained, controlling the energy level of the ghost image. In this way, the quantity and energy of stray light are reduced simultaneously, which helps to significantly improve the image quality.

[0075] It should be noted that those skilled in the art should understand that, without departing from the technical solutions claimed in this application, the number of spacers constituting the imaging lens can be changed to obtain the various results and advantages described in this specification, and this application does not specifically limit this. For example, as needed, the optical imaging lens may also include other numbers of spacers than those described in the above embodiments.

[0076] The following describes in more detail some specific, non-limiting embodiments of the above-described embodiments of this application with reference to the accompanying drawings. For ease of description, in the following embodiments, OBJ represents the object plane of the imaging lens, STO represents the surface of the aperture stop, S1 represents the object-side plane of the first lens E1, S2 represents the image-side plane of the first lens E1, S3 represents the object-side plane of the second lens E2, S4 represents the image-side plane of the second lens E2, S5 represents the object-side plane of the third lens E3, S6 represents the image-side plane of the third lens E3, S7 represents the object-side plane of the fourth lens E4, S8 represents the image-side plane of the fourth lens E4, S9 represents the object-side plane of the filter E5, S10 represents the image-side plane of the filter E5, and S11 represents the image plane.

[0077] Example 1

[0078] like Figure 3As shown, in this embodiment, the imaging lens includes a lens barrel P0 and a lens group and a plurality of spacer elements housed in the lens barrel P0; the lens group includes a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4, wherein the second lens E2 is a superlens and the image-side surface of the second lens E2 is a metasurface; the plurality of spacer elements include a first spacer element P1 placed between the first lens E1 and the second lens E2 and abutting against the image-side surface of the first lens E1, a second spacer element P2 placed between the second lens E2 and the third lens E3 and abutting against the image-side surface of the second lens E2, and a third spacer element P3 placed between the third lens E3 and the fourth lens E4 and abutting against the image-side surface of the third lens E3.

[0079] In this embodiment, the first lens E1 has positive optical power, the object side of the first lens E1 is convex and the image side is concave; the second lens E2 has positive optical power, the object side of the second lens E2 is convex and the image side of the second lens E2 is flat; the third lens E3 has negative optical power, the object side of the third lens E3 is concave and the image side is convex; and the fourth lens E4 has negative optical power, the object side of the fourth lens E4 is convex and the image side is concave.

[0080] In addition, Table 1 shows the basic optical parameters of the optical imaging lens of Embodiment 1, where the units for radius of curvature and thickness are millimeters (mm).

[0081] Table 1

[0082]

[0083] In this embodiment, the object-side surface and image-side surface of any one of the first lens E1, the third lens E3, and the fourth lens E4 are aspherical, and the object-side surface of the second lens E2 is aspherical. The surface shape x of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0084] ;

[0085] 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 R 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 higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for the aspherical mirrors S1, S2, S3, S5, S6, S7, and S8 in Example 1.

[0086] Table 2-1

[0087]

[0088] Table 2-2

[0089]

[0090] In this embodiment, the image-side surface of the second lens E2 is a metasurface, which can be defined using, but is not limited to, the following metasurface phase equation:

[0091] ;

[0092] Where φ(r) is the phase profile, d is the diffraction order, λ0 is the reference wavelength, r is the radial coordinate, and Ci is the coefficient of the metasurface phase equation, i=1, 2, 3, 4, 5.

[0093] Table 3 below gives the coefficient values ​​of the metasurface phase equation applicable to S4 in this embodiment.

[0094] Table 3

[0095]

[0096] Example 2

[0097] like Figure 4 As shown, in this embodiment, the imaging lens includes a lens barrel P0 and a lens group and a plurality of spacer elements housed in the lens barrel P0; the lens group includes a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4, wherein the second lens E2 is a superlens and the image-side surface of the second lens E2 is a metasurface; the plurality of spacer elements include a first spacer element P1 placed between the first lens E1 and the second lens E2 and abutting against the image-side surface of the first lens E1, a second spacer element P2 placed between the second lens E2 and the third lens E3 and abutting against the image-side surface of the second lens E2, and a third spacer element P3 placed between the third lens E3 and the fourth lens E4 and abutting against the image-side surface of the third lens E3.

[0098] It is worth noting that, compared with Embodiment 1 above, the imaging lens of Embodiment 2 has the same optical parameters. That is, the basic optical parameter table of the imaging lens of Embodiment 2 is the same as Table 1, the aspherical coefficient table is the same as Tables 2-1 and 2-2, and the phase equation coefficient is the same as Table 3. However, the imaging lens of Embodiment 2 has different optical parameters from the imaging lens of Embodiment 1 above. That is, the difference between Embodiment 2 and Embodiment 1 above lies in the different dimensional values ​​of some structural parameters of the lens barrel P0 and multiple spacer elements in the imaging lens.

[0099] Specifically, the values ​​of the relevant structural parameters in Embodiment 2 and Embodiment 1 above are shown in Table 11 below. It should be understood that the units of the values ​​for each parameter shown in Table 11 are millimeters (mm), and the schematic diagrams of each parameter in the imaging lens structure are as follows... Figure 1 As shown.

[0100] Example 3

[0101] like Figure 5 As shown, in this embodiment, the imaging lens includes a lens barrel P0 and a lens group and a plurality of spacer elements housed in the lens barrel P0; the lens group includes a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4, wherein the second lens E2 is a superlens and the image-side surface of the second lens E2 is a metasurface; the plurality of spacer elements include a first spacer element P1 placed between the first lens E1 and the second lens E2 and abutting against the image-side surface of the first lens E1, a second spacer element P2 placed between the second lens E2 and the third lens E3 and abutting against the image-side surface of the second lens E2, and a third spacer element P3 placed between the third lens E3 and the fourth lens E4 and abutting against the image-side surface of the third lens E3.

[0102] It is worth noting that, compared with Embodiment 1 above, the imaging lens of Embodiment 3 has the same optical parameters. That is, the basic optical parameter table of the imaging lens of Embodiment 2 is the same as Table 1, the aspherical coefficient table is the same as Tables 2-1 and 2-2, and the phase equation coefficient is the same as Table 3. However, the imaging lens of Embodiment 3 has different optical parameters from the imaging lens of Embodiment 1 above. That is, the difference between Embodiment 3 and Embodiment 1 above lies in the different dimensional values ​​of some structural parameters of the lens barrel P0 and the spacer element in the imaging lens.

[0103] Specifically, the values ​​of the relevant structural parameters in Embodiment 3 and Embodiment 1 above are shown in Table 11 below. It should be understood that the units of the values ​​for each parameter shown in Table 11 are millimeters (mm), and the schematic diagrams of each parameter in the imaging lens structure are as follows... Figure 1 As shown.

[0104] The on-axis chromatic aberration curves of the imaging lenses in Examples 1, 2, and 3 are as follows: Figure 6A As shown, this represents the degree of deviation of the focal point after light of different wavelengths passes through the imaging lens; the astigmatism curves of the imaging lenses in Embodiments 1, 2, and 3 are shown below. Figure 6B As shown, it represents the curvature of the meridional image plane and the curvature of the sagittal image plane. The distortion curves of the imaging lenses in Embodiments 1, 2, and 3 are as follows: Figure 6C As shown, this indicates the relative deviation between the actual image and the ideal image captured by the imaging lens. According to... Figure 6A , Figure 6B and Figure 6C It can be seen that the imaging lenses in Embodiment 1, Embodiment 2 and Embodiment 3 can all achieve good imaging quality.

[0105] Example 4

[0106] like Figure 7 As shown, in this embodiment, the imaging lens includes a lens barrel P0 and a lens group and a plurality of spacer elements housed in the lens barrel P0; the lens group includes a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4, wherein the second lens E2 is a superlens and the image-side surface of the second lens E2 is a metasurface; the plurality of spacer elements include a first spacer element P1 placed between the first lens E1 and the second lens E2 and abutting against the image-side surface of the first lens E1, a second spacer element P2 placed between the second lens E2 and the third lens E3 and abutting against the image-side surface of the second lens E2, and a third spacer element P3 placed between the third lens E3 and the fourth lens E4 and abutting against the image-side surface of the third lens E3.

[0107] In this embodiment, the first lens E1 has positive optical power, the object side of the first lens E1 is convex and the image side is concave; the second lens E2 has positive optical power, the object side of the second lens E2 is convex and the image side of the second lens E2 is flat; the third lens E3 has negative optical power, the object side of the third lens E3 is concave and the image side is convex; and the fourth lens E4 has negative optical power, the object side of the fourth lens E4 is convex and the image side is concave.

[0108] In addition, Table 4 shows the basic optical parameters of the imaging lens of Embodiment 4, where the units for radius of curvature and thickness are millimeters (mm).

[0109] Table 4

[0110]

[0111] In this embodiment, the object-side surface and image-side surface of any one of the first lens E1, the third lens E3, and the fourth lens E4 are aspherical, and the object-side surface of the second lens E2 is aspherical. The surface shape x of each aspherical lens can be defined using, but is not limited to, the aspherical formula in this embodiment.

[0112] Tables 5-1 and 5-2 below give the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for each aspherical mirror S1, S2, S3, S5, S6, S7, and S8 in Example 4.

[0113] Table 5-1

[0114]

[0115] Table 5-2

[0116]

[0117] In this embodiment, the image-side surface of the second lens E2 is a metasurface, which can be defined using, but is not limited to, the metasurface phase equation in Embodiment 1.

[0118] Table 6 below gives the coefficient values ​​of the metasurface phase equation applicable to S4 in this embodiment.

[0119] Table 6

[0120]

[0121] Example 5

[0122] like Figure 8 As shown, in this embodiment, the imaging lens includes a lens barrel P0 and a lens group and a plurality of spacer elements housed in the lens barrel P0; the lens group includes a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4, wherein the second lens E2 is a superlens and the image-side surface of the second lens E2 is a metasurface; the plurality of spacer elements include a first spacer element P1 placed between the first lens E1 and the second lens E2 and abutting against the image-side surface of the first lens E1, a second spacer element P2 placed between the second lens E2 and the third lens E3 and abutting against the image-side surface of the second lens E2, and a third spacer element P3 placed between the third lens E3 and the fourth lens E4 and abutting against the image-side surface of the third lens E3.

[0123] It is worth noting that, compared with Embodiment 4 above, the imaging lens of Embodiment 5 has the same optical parameters. That is, the basic optical parameter table of the imaging lens of Embodiment 5 is the same as Table 4, the aspherical coefficient table is the same as Tables 5-1 and 5-2, and the phase equation coefficient is the same as Table 6. However, the imaging lens of Embodiment 5 has different optical parameters from the imaging lens of Embodiment 4 above. That is, the difference between Embodiment 5 and Embodiment 4 above lies in the different dimensional values ​​of some structural parameters of the lens barrel P0 and multiple spacer elements in the imaging lens.

[0124] Specifically, the values ​​of the relevant structural parameters in Embodiment 5 and Embodiment 4 above are shown in Table 11 below. It should be understood that the unit of the values ​​of each parameter shown in Table 11 is millimeters (mm), and the schematic diagram of each parameter in the imaging lens structure is shown below. Figure 1 As shown.

[0125] Example 6

[0126] like Figure 9As shown, in this embodiment, the imaging lens includes a lens barrel P0 and a lens group and a plurality of spacer elements housed in the lens barrel P0; the lens group includes a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4, wherein the second lens E2 is a superlens and the image-side surface of the second lens E2 is a metasurface; the plurality of spacer elements include a first spacer element P1 placed between the first lens E1 and the second lens E2 and abutting against the image-side surface of the first lens E1, a second spacer element P2 placed between the second lens E2 and the third lens E3 and abutting against the image-side surface of the second lens E2, and a third spacer element P3 placed between the third lens E3 and the fourth lens E4 and abutting against the image-side surface of the third lens E3.

[0127] It is worth noting that, compared with Embodiment 4 above, the imaging lens of Embodiment 6 has the same optical parameters. That is, the basic optical parameter table of the imaging lens of Embodiment 6 is the same as Table 4, the aspherical coefficient table is the same as Tables 5-1 and 5-2, and the phase equation coefficient is the same as Table 6. However, the imaging lens of Embodiment 6 has different optical parameters from the imaging lens of Embodiment 4 above. That is, the difference between Embodiment 6 and Embodiment 4 above lies in the different dimensional values ​​of some structural parameters of the lens barrel P0 and multiple spacer elements in the imaging lens.

[0128] Specifically, the values ​​of the relevant structural parameters in Embodiment Six and Embodiment Four are shown in Table 11 below. It should be understood that the units of the values ​​shown in Table 11 are millimeters (mm), and the schematic diagrams of the parameters in the imaging lens structure are as follows: Figure 1 and Figure 2 As shown.

[0129] The on-axis chromatic aberration curves of the imaging lenses in Examples 4, 5, and 6 are as follows: Figure 10A As shown, this represents the degree of deviation of the focal point after light of different wavelengths passes through the imaging lens; the astigmatism curves of the imaging lenses in Examples 4, 5, and 6 are shown below. Figure 10B As shown, it represents the curvature of the meridional image plane and the curvature of the sagittal image plane. The distortion curves of the imaging lenses in Examples 4, 5, and 6 are as follows: Figure 10C As shown, this indicates the relative deviation between the actual image and the ideal image captured by the imaging lens. According to... Figure 10A , Figure 10B and Figure 10C It can be seen that the imaging lenses in Embodiments 4, 5 and 6 can all achieve good imaging quality.

[0130] Example 7

[0131] like Figure 11As shown, in this embodiment, the imaging lens includes a lens barrel P0 and a lens group and a plurality of spacer elements housed in the lens barrel P0; the lens group includes a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4, wherein the second lens E2 is a superlens and the image-side surface of the second lens E2 is a metasurface; the plurality of spacer elements include a first spacer element P1 placed between the first lens E1 and the second lens E2 and abutting against the image-side surface of the first lens E1, a second spacer element P2 placed between the second lens E2 and the third lens E3 and abutting against the image-side surface of the second lens E2, and a third spacer element P3 placed between the third lens E3 and the fourth lens E4 and abutting against the image-side surface of the third lens E3.

[0132] In this embodiment, the first lens E1 has positive optical power, the object side of the first lens E1 is convex and the image side is concave; the second lens E2 has positive optical power, the object side of the second lens E2 is convex and the image side of the second lens E2 is flat; the third lens E3 has negative optical power, the object side of the third lens E3 is concave and the image side is convex; and the fourth lens E4 has negative optical power, the object side of the fourth lens E4 is convex and the image side is concave.

[0133] In addition, Table 7 shows the basic optical parameters of the imaging lens of Embodiment 7, where the units for radius of curvature and thickness are millimeters (mm).

[0134] Table 7

[0135]

[0136] In this embodiment, the object-side surface and image-side surface of any one of the first lens E1, the third lens E3, and the fourth lens E4 are aspherical, and the object-side surface of the second lens E2 is aspherical. The surface shape x of each aspherical lens can be defined using, but is not limited to, the aspherical formula in Embodiment 1.

[0137] Tables 8-1 and 8-2 below give the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for each aspherical mirror S1, S2, S3, S5, S6, S7, and S8 in Example 7.

[0138] Table 8-1

[0139]

[0140] Table 8-2

[0141]

[0142] In this embodiment, the image-side surface of the second lens E2 is a metasurface, which can be defined using, but is not limited to, the metasurface phase equation in Embodiment 1.

[0143] Table 9 below gives the coefficient values ​​of the metasurface phase equation applicable to S4 in this embodiment.

[0144] Table 9

[0145]

[0146] Example 8

[0147] like Figure 12 As shown, in this embodiment, the imaging lens includes a lens barrel P0 and a lens group and a plurality of spacer elements housed in the lens barrel P0; the lens group includes a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4, wherein the second lens E2 is a superlens and the image-side surface of the second lens E2 is a metasurface; the plurality of spacer elements include a first spacer element P1 placed between the first lens E1 and the second lens E2 and abutting against the image-side surface of the first lens E1, a second spacer element P2 placed between the second lens E2 and the third lens E3 and abutting against the image-side surface of the second lens E2, and a third spacer element P3 placed between the third lens E3 and the fourth lens E4 and abutting against the image-side surface of the third lens E3.

[0148] It is worth noting that, compared with Embodiment 7 above, the imaging lens of Embodiment 8 has the same optical parameters. That is, the basic optical parameter table of the imaging lens of Embodiment 8 is the same as Table 7, the aspherical coefficient table is the same as Tables 8-1 and 8-2, and the phase equation coefficient is the same as Table 9. However, the imaging lens of Embodiment 8 has different optical parameters from the imaging lens of Embodiment 7 above. That is, the difference between Embodiment 8 and Embodiment 7 is that the dimensions of some structural parameters of the lens barrel P0 and multiple spacer elements in the imaging lens are different.

[0149] Specifically, the values ​​of the relevant structural parameters in Embodiment 8 and Embodiment 7 are shown in Table 11 below. It should be understood that the units of the values ​​shown in Table 11 are millimeters (mm), and the schematic diagrams of the parameters in the imaging lens structure are as follows: Figure 1 As shown.

[0150] Example 9

[0151] like Figure 13As shown, in this embodiment, the imaging lens includes a lens barrel P0 and a lens group and a plurality of spacer elements housed in the lens barrel P0; the lens group includes a first lens E1, a second lens E2, a third lens E3 and a fourth lens E4, wherein the second lens E2 is a superlens and the image-side surface of the second lens E2 is a metasurface; the plurality of spacer elements include a first spacer element P1 placed between the first lens E1 and the second lens E2 and abutting against the image-side surface of the first lens E1, a second spacer element P2 placed between the second lens E2 and the third lens E3 and abutting against the image-side surface of the second lens E2, and a third spacer element P3 placed between the third lens E3 and the fourth lens E4 and abutting against the image-side surface of the third lens E3.

[0152] It is worth noting that, compared with Embodiment 7 above, the imaging lens of Embodiment 9 has the same optical parameters. That is, the basic optical parameter table of the imaging lens of Embodiment 9 is the same as Table 7, the aspherical coefficient table is the same as Tables 8-1 and 8-2, and the phase equation coefficient is the same as Table 9. However, the imaging lens of Embodiment 9 has different optical parameters from the imaging lens of Embodiment 7 above. That is, the difference between Embodiment 9 and Embodiment 7 is that the dimensional values ​​of some structural parameters of the lens barrel P0 and multiple spacer elements in the imaging lens are different.

[0153] Specifically, the values ​​of the relevant structural parameters in Embodiment Nine and Embodiment Seven above are shown in Table 11 below. It should be understood that the unit of the values ​​of each parameter shown in Table 11 is millimeters (mm), and the schematic diagram of each parameter in the imaging lens structure is shown below. Figure 1 As shown.

[0154] The on-axis chromatic aberration curves of the imaging lenses in Examples 7, 8, and 9 are as follows: Figure 14A As shown, this represents the degree of deviation of the focal point after light of different wavelengths passes through the imaging lens; the astigmatism curves of the imaging lenses in Examples 7, 8, and 9 are shown below. Figure 14B As shown, it represents the curvature of the meridional image plane and the curvature of the sagittal image plane. The distortion curves of the imaging lenses in Examples 7, 8, and 9 are as follows: Figure 14C As shown, this indicates the relative deviation between the actual image and the ideal image captured by the imaging lens. According to... Figure 14A , Figure 14B and Figure 14C It can be seen that the imaging lenses in Embodiments 7, 8 and 9 can all achieve good imaging quality.

[0155] In summary, in Examples 1 to 9, the effective focal length f of the imaging lens, the effective focal lengths f1 to f4 of the first lens E1 to the fourth lens E4 in the imaging lens, the sum of the center thicknesses ∑CT of the first lens E1, the second lens E2, the third lens E3 and the fourth lens E4 in the imaging lens, the axial distance MD from the image side of the second lens E2 to the image side of the fourth lens E4, and the effective diameter DR22 of the image side of the second lens E2 are shown in Table 10 below.

[0156] Table 10

[0157]

[0158] In addition, some structural parameters of the imaging lenses in Examples 1 to 9 are shown in Table 11.

[0159] Table 11

[0160]

[0161] In the table above, the structural parameters are defined as follows: d1s is the inner diameter of the object side of the first spacer element P1, d1m is the inner diameter of the image side of the first spacer element P1, D1s is the outer diameter of the object side of the first spacer element P1, D1m is the outer diameter of the image side of the first spacer element P1, d2s is the inner diameter of the object side of the second spacer element P2, d2m is the inner diameter of the image side of the second spacer element P2, D2s is the outer diameter of the object side of the second spacer element P2, d3s is the inner diameter of the object side of the third spacer element P3, d3m is the inner diameter of the image side of the third spacer element P3, D3s is the outer diameter of the object side of the third spacer element P3, D3m is the outer diameter of the image side of the third spacer element P3, d0s is the inner diameter of the object side of the lens barrel P0, D0s is the outer diameter of the object side of the lens barrel P0. D0m is the outer diameter of the image side of the lens barrel P0, EP01 is the distance from the object side of the lens barrel P0 to the object side of the first spacer element P1 along the optical axis, CP1 is the maximum thickness of the first spacer element P1 along the optical axis, EP12 is the distance from the image side of the first spacer element P1 to the object side of the second spacer element P2 along the optical axis, CP2 is the maximum thickness of the second spacer element P2 along the optical axis, EP23 is the distance from the image side of the second spacer element P2 to the object side of the third spacer element P3 along the optical axis, CP3 is the maximum thickness of the third spacer element P3 along the optical axis, L is the maximum height from the object side of the lens barrel P0 to the image side of the lens barrel P0, and EP13 is the distance from the object side of the first spacer element P1 to the image side of the third spacer element P3 along the optical axis.

[0162] In summary, the imaging lenses in Examples 1 to 9 satisfy the relationships shown in Table 12, as detailed in Table 12.

[0163] Table 12

[0164]

[0165] It is worth mentioning that, according to one aspect of this application, one embodiment of this application further provides a camera module, which may include the aforementioned imaging lens and a photosensitive element, the photosensitive element being disposed on the image side of the imaging lens for imaging. It is understood that the photosensitive element mentioned in this application may, but is not limited to, be implemented as a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) device, and this application will not elaborate further on this.

[0166] Furthermore, according to another aspect of this application, one embodiment of this application provides an electronic device that may include a camera module and a processor as described above. The camera module is communicatively connected to the processor for acquiring image data and inputting the image data into the processor for processing. It is understood that the electronic device mentioned in this application may, but is not limited to, a device such as a mobile phone equipped with the camera module, and this application will not elaborate further on this.

[0167] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0168] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An imaging lens, comprising a lens barrel and a lens group and a plurality of spacer elements mounted within the lens barrel, characterized in that, The lens group, from the object side to the image side, includes, in sequence: a first lens with positive optical power, a second lens with positive optical power, a third lens with negative optical power, and a fourth lens with negative optical power. The object-side surface and image-side surface of the first lens are convex and concave, respectively; the object-side surface and image-side surface of the second lens are convex and flat, respectively; the object-side surface and image-side surface of the third lens are concave and convex, respectively; and the object-side surface and image-side surface of the fourth lens are convex and concave, respectively. The imaging lens has four lenses with optical power. The plurality of spacers, from the object side to the image side, sequentially include: a first spacer, a second spacer, and a third spacer, wherein the first spacer is located between the first lens and the second lens and abuts against the image side of the first lens, the second spacer is located between the second lens and the third lens and abuts against the image side of the second lens, and the third spacer is located between the third lens and the fourth lens and abuts against the image side of the third lens. The second lens is a superlens, and the image-side surface of the second lens is a metasurface; The imaging lens satisfies the following conditions: 8.8 < L / CT2 < 9.8, 7.3 < (D1m - d1m) / T12 < 11.8, 1.85 < (d2s + d2m) / DR22 < 2.25, 0.85 < f2 / (D2s + D2m) < 1.55, and -4.05 < f4 / d3m < -2.35, where L is the maximum height from the object side of the lens barrel to the image side of the lens barrel, CT2 is the center thickness of the second lens on the optical axis, D1m is the outer diameter of the image side of the first spacer element, and d1m is the maximum thickness of the second lens on the optical axis. The inner diameter of the image side of the first spacer element, T12 is the air gap between the first lens and the second lens on the optical axis, d2s is the inner diameter of the object side of the second spacer element, d2m is the inner diameter of the image side of the second spacer element, DR22 is the effective diameter of the image side of the second lens, f2 is the effective focal length of the second lens, D2s is the outer diameter of the object side of the second spacer element, D2m is the outer diameter of the image side of the second spacer element, f4 is the effective focal length of the fourth lens, and d3m is the inner diameter of the image side of the third spacer element.

2. The imaging lens according to claim 1, characterized in that, The metasurface includes a substrate and microstructures formed on the substrate, wherein the surface of the substrate is planar and the substrate is made of glass.

3. The imaging lens according to claim 1, characterized in that, The imaging lens also satisfies: 3.30≤f / EP13≤3.84, where f is the system focal length of the imaging lens and EP13 is the distance along the optical axis from the object side of the first spacer element to the image side of the third spacer element.

4. The imaging lens according to claim 1, characterized in that, The imaging lens also satisfies: 6.55 < f1 / EP01 < 7.7, where f1 is the effective focal length of the first lens and EP01 is the distance along the optical axis from the side of the lens barrel to the side of the first spacer element.

5. The imaging lens according to claim 1, characterized in that, The imaging lens also satisfies: 1.05 < (D0s - d0s) / R1 < 1.6, where D0s is the outer diameter of the side surface of the lens barrel, d0s is the inner diameter of the side surface of the lens barrel, and R1 is the radius of curvature of the side surface of the first lens.

6. The imaging lens according to claim 1, characterized in that, The imaging lens also satisfies: 4.15≤d3s / T34≤6.88, where d3s is the inner diameter of the side of the third spacer element and T34 is the air gap between the third lens and the fourth lens on the optical axis.

7. The imaging lens according to claim 1, characterized in that, The imaging lens also satisfies: 2.0 < (EP23 + CP3) / CT3 < 2.35, where EP23 is the distance from the image side of the second spacer element to the object side of the third spacer element along the optical axis, CP3 is the maximum thickness of the third spacer element along the optical axis, and CT3 is the center thickness of the third lens on the optical axis.

8. The imaging lens according to claim 1, characterized in that, The imaging lens also satisfies: 1.9 < D3s / MD < 3.2, where D3s is the outer diameter of the object side of the third spacer element, and MD is the on-axis distance from the image side of the second lens to the image side of the fourth lens.

9. The imaging lens according to claim 1, characterized in that, The imaging lens also satisfies: 1.05 < R2 / d1s < 1.5, where R2 is the radius of curvature of the image side of the first lens and d1s is the inner diameter of the object side of the first spacer element.

10. The imaging lens according to claim 1, characterized in that, The imaging lens also satisfies: 1.4 < D0m / D3m < 1.85, where D0m is the outer diameter of the image side of the lens barrel and D3m is the outer diameter of the image side of the third spacer element.

11. The imaging lens according to claim 1, characterized in that, The imaging lens also satisfies: 5.34≤(D1s-d1s) / EP12≤7.30, where D1s is the outer diameter of the side surface of the first spacer element, d1s is the inner diameter of the side surface of the first spacer element, and EP12 is the distance from the image side surface of the first spacer element to the side surface of the second spacer element along the optical axis.

12. The imaging lens according to claim 1, characterized in that, The imaging lens also satisfies: 3.05mm < R3 × (CP1 / CP2) < 4.45mm, where R3 is the radius of curvature of the side surface of the second lens, CP1 is the maximum thickness of the first spacer element along the optical axis, and CP2 is the maximum thickness of the second spacer element along the optical axis.

13. The imaging lens according to claim 1, characterized in that, The imaging lens also satisfies: 4.35 < d0m / ∑CT < 4.75, where d0m is the inner diameter of the image side of the lens barrel, and ∑CT is the sum of the center thicknesses of the first lens, the second lens, the third lens, and the fourth lens on the optical axis.

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