An optical imaging lens

Abstract

The application discloses an optical imaging lens, wherein the center thickness CT1 of the first lens, the center thickness CT2 of the second lens, and the air interval T12 of the first lens and the second lens on the optical axis satisfy 1.00<(CT1+CT2) / T12≤1.70; the distance EP01 of the object side of the lens barrel to the object side of the first interval element along the optical axis direction, and the center thickness CT1 of the first lens satisfy 4.10≤EP01 / CT1≤4.87; the object side outer diameter D1s of the first interval element, the object side outer diameter D2s of the second interval element, and the distance EP12 of the image side of the first interval element to the object side of the second interval element along the optical axis direction satisfy 0.11≤|D1s-D2s| / EP12<0.90. The optical imaging lens disclosed by the application strengthens the mechanical strength by reasonably controlling the structural size of the lens and the interval element, and ensures the stable performance of the lens in the assembling process.

Description

Technical Field

[0001] This application generally relates to the field of optical imaging equipment technology. More specifically, this application relates to an optical imaging lens. Background Technology

[0002] With the continuous advancement of electronic technology, high-end flagship smartphones have widely entered the consumer market, and consumers' demands for smartphone photography functions are increasing daily. In the field of imaging, eight-element imaging lenses, with their unique structural advantages and potential for performance improvement, have gradually become a research hotspot in the industry and have received widespread attention.

[0003] However, the increase in the number of lens elements is a double-edged sword. While it brings performance improvements to eight-element imaging lenses, the increase in the number of lens elements poses a severe challenge to the stability of lens assembly. Among them, the precise control of the inner and outer diameters of the spacer elements and the reasonable design of the bearing structure between the lens elements and the lens barrel are key factors affecting the assembly performance and production yield of the lens.

[0004] In view of this, this application provides an optical imaging lens that enhances mechanical strength and ensures stable performance of the lens during assembly by reasonably controlling the structural dimensions of the lens and the spacer element. Summary of the Invention

[0005] In order to at least solve one or more of the technical problems mentioned above, this application proposes an optical imaging lens in the following aspects.

[0006] In a first aspect, this application provides an optical imaging lens, including a lens barrel and a lens group and a plurality of spacers disposed in the lens barrel, wherein at least one spacer is disposed between any two adjacent lenses in the lens group; the lens group includes, in sequence along the optical axis from the object side to the image side: a first lens having negative optical power, the image side of which is concave; a second lens having positive optical power; a third lens having either positive or negative optical power, the object side of which is convex and the image side of which is concave; a fourth lens having positive optical power, both the object side and the image side of which are convex; a fifth lens having positive optical power, the image side of which is convex; a sixth lens having positive optical power, the image side of which is convex; a seventh lens having negative optical power, the image side of which is concave; and an eighth lens having negative optical power, the object side of which is convex and the image side of which is concave; the plurality of spacers include a first spacer and a second spacer; the first spacer is disposed between the first lens and the second lens, and the object side of the first spacer is concave and the image side of the second lens are concave and convex. The image-side surface of the first lens is in contact with the third lens; the second spacer element is disposed between the second lens and the third lens, and the object-side surface of the second spacer element is in contact with the image-side surface of the second lens; the center thickness CT1 of the first lens, the center thickness CT2 of the second lens, and the air gap T12 between the first lens and the second lens on the optical axis satisfy: 1.00 < (CT1 + CT2) / T12 ≤ 1.70; the distance EP01 from the object-side surface of the lens barrel to the object-side surface of the first spacer element along the optical axis, and the center thickness CT1 of the first lens satisfy: 4.10 ≤ EP01 / CT1 ≤ 4.87; the outer diameter D1s of the object-side surface of the first spacer element, the outer diameter D2s of the object-side surface of the second spacer element, and the distance EP12 from the image-side surface of the first spacer element to the object-side surface of the second spacer element along the optical axis satisfy: 0.11 ≤ |D1s - D2s| / EP12 < 0.90.

[0007] In some embodiments, the outer diameter D2s of the object side of the second spacer, the inner diameter d2s of the object side of the second spacer, and the maximum thickness CP2 of the second spacer along the optical axis satisfy the following: 2.35 < (D2s - d2s) / CP2 ≤ 10.72.

[0008] In some embodiments, the air gap T23 between the second lens and the third lens on the optical axis, and the maximum thickness CP2 of the second spacer element along the optical axis direction, satisfy the following condition: 0.57 ≤ T23 / CP2 < 1.85.

[0009] In some embodiments, the plurality of spacers includes a second auxiliary spacer; the second auxiliary spacer is disposed between the second spacer and the third lens, and the object side of the second auxiliary spacer partially contacts the image side of the second spacer; the outer diameter D2bs of the object side of the second auxiliary spacer, the inner diameter d2bs of the object side of the second auxiliary spacer, the outer diameter D2m of the image side of the second spacer, and the inner diameter d2m of the image side of the second spacer satisfy the following: 3.30 < (D2bs - d2bs) / (D2m - d2m) < 5.15.

[0010] In some embodiments, the plurality of spacers further includes a third spacer and a fourth spacer; the third spacer is disposed between the third lens and the fourth lens, and the object-side surface of the third spacer is in contact with the image-side surface of the third lens; the fourth spacer is disposed between the fourth lens and the fifth lens, and the object-side surface of the fourth spacer is in contact with the image-side surface of the fourth lens; the outer diameter of the object-side surface of the fourth spacer D4s, the outer diameter of the image-side surface of the third spacer D3m, and the combined focal length f34 of the third lens and the fourth lens satisfy the following: 2.45 < (D4s + D3m) / f34 ≤ 3.51.

[0011] In some embodiments, the plurality of spacers further includes a fourth spacer and a fifth spacer; the fourth spacer is disposed between the fourth lens and the fifth lens, and the object-side surface of the fourth spacer is in contact with the image-side surface of the fourth lens; the fifth spacer is disposed between the fifth lens and the sixth lens, and the object-side surface of the fifth spacer is in contact with the image-side surface of the fifth lens; the outer diameter D4m of the image-side surface of the fourth spacer, the outer diameter D5s of the object-side surface of the fifth lens, and the distance EP45 from the image-side surface of the fourth spacer to the object-side surface of the fifth spacer along the optical axis satisfy the following: 2.00 ≤ EP45 / (D4m-D5s) < 9.30.

[0012] In some embodiments, the plurality of spacers further includes a fifth spacer element disposed between the fifth lens and the sixth lens, wherein the object-side surface of the fifth spacer element is in contact with the image-side surface of the fifth lens; the effective focal length f5 of the fifth lens and the inner diameter d5s of the object-side surface of the fifth spacer element satisfy the following: 1.59 ≤ f5 / d5s < 3.60.

[0013] In some embodiments, the plurality of spacers further includes a sixth spacer and a seventh spacer; the sixth spacer is disposed between the sixth lens and the seventh lens, and the object-side surface of the sixth spacer is in contact with the image-side surface of the sixth lens; the seventh spacer is disposed between the seventh lens and the eighth lens, and the object-side surface of the seventh spacer is in contact with the image-side surface of the seventh lens; the distance EP67 between the image-side surface of the sixth spacer and the object-side surface of the seventh spacer along the optical axis, the maximum thickness CP7 of the seventh spacer along the optical axis, the air gap T67 between the sixth lens and the seventh lens on the optical axis, and the center thickness CT7 of the seventh lens satisfy the following: 2.10 < (EP67 + CP7) / (T67 + CT7) < 3.75.

[0014] In some embodiments, the plurality of spacers further includes a seventh spacer; the seventh spacer is disposed between the seventh lens and the eighth lens, and the object-side surface of the seventh spacer is in contact with the image-side surface of the seventh lens; the radius of curvature R15 of the object-side surface of the eighth lens, the radius of curvature R16 of the image-side surface of the eighth lens, and the center thickness CT8 of the eighth lens satisfy the following: 22.89≤(R15+R16) / CT8≤27.88; the inner diameter d7s of the object-side surface of the seventh spacer and the radius of curvature R15 of the object-side surface of the eighth lens satisfy the following: 0.50≤d7s / R15≤1.58.

[0015] In some embodiments, the maximum height L of the lens barrel satisfies the following relationship with the distance Tr7r12 on the optical axis from the object side of the fourth lens to the image side of the sixth lens: 3.90 < L / Tr7r12 < 4.75.

[0016] In some embodiments, the plurality of spacers further includes a seventh spacer and a seventh auxiliary spacer; the seventh spacer is disposed between the seventh lens and the eighth lens, and the object-side surface of the seventh spacer is in contact with the image-side surface of the seventh lens; the seventh auxiliary spacer is disposed between the seventh spacer and the eighth lens, and the object-side surface of the seventh auxiliary spacer is in contact with the image-side surface of the seventh spacer; the radius of curvature R14 of the image-side surface of the seventh lens and the inner diameter d7bs of the object-side surface of the seventh auxiliary spacer satisfy the following condition: 0.53 ≤ R14 / d7bs < 1.60.

[0017] In some embodiments, the plurality of spacers further includes a seventh spacer; the seventh spacer is disposed between the seventh lens and the eighth lens, and the object side of the seventh spacer is in contact with the image side of the seventh lens; the effective focal length f7 of the seventh lens and the maximum thickness CP7 of the seventh spacer along the optical axis satisfy the following: -15.40 < f7 / CP7 ≤ -7.24.

[0018] In some embodiments, the plurality of spacers further includes an eighth spacer; the eighth spacer is disposed on the mirror side of the eighth lens, and the object side of the eighth spacer is in partial contact with the mirror side of the eighth lens; the inner diameter d8m of the image side of the eighth spacer, the inner diameter d1s of the object side of the first spacer, and the effective focal length f of the optical imaging lens satisfy the following: 1.55 < (d8m - d1s) / f ≤ 2.16.

[0019] In some embodiments, the axial distance TD between the object side of the first lens and the image side of the eighth lens, the outer diameter D0m of the image side of the lens barrel, and the outer diameter D0s of the object side of the lens barrel satisfy the following: 2.13≤TD / (D0m-D0s)≤8.75.

[0020] Using the optical imaging lens provided above, this application sets the lens group to eight lenses arranged sequentially along the optical axis from the object side to the image side, each with a specific optical power and surface shape. At least one spacer element is placed between any two adjacent lenses, with the first and second spacers located between the first and second lenses, and between the second and third lenses, respectively, and in contact with the image-side portion of the corresponding object-side lens. Simultaneously, by controlling 1.00 < (CT1 + CT2) / T12 ≤ 1.70, a reference is provided for the axial positioning of the first and second lenses. Furthermore, by controlling 4.10 ≤ EP01 / CT1 ≤ 4.87 and 0.11 ≤ |D1s - D2s| / EP12 < The 0.90 guideline for the tapered or stepped design of the lens barrel front end simplifies the lens barrel manufacturing process and ensures that the inner diameter of the lens barrel matches the dimensions of the first lens and spacer elements, reducing assembly difficulties or component interference caused by size mismatch. At the same time, it can optimize the outer diameter difference of the spacer elements, enhance the mechanical strength of the spacer elements, and effectively optimize the situation where the local stress of the second lens is too large due to the excessive fit between the first and second spacer elements during assembly. It also reduces lens deformation or damage caused by external forces, thereby solving the assembly stability challenge faced by eight-lens imaging devices due to the increase in the number of lenses, ensuring that the lens maintains stable performance during assembly, and improving the lens assembly performance and production yield. Attached Figure Description

[0021] The above and other objects, features, and advantages of exemplary embodiments of this application will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of this application are illustrated by way of example and not limitation, and the same or corresponding reference numerals denote the same or corresponding parts, wherein:

[0022] Figure 1 A partial structural schematic diagram of an optical imaging lens according to an optional embodiment of this application is shown;

[0023] Figure 2 A partial dimension annotation of the optical imaging lens of one alternative embodiment of this application is shown;

[0024] Figure 3 The following is an optional example of the stress diagram of the second lens satisfying (CT1+CT2) / T12=1.25, EP01 / CT1=3.86, and |D1s-D2s| / EP12=0.05:

[0025] Figure 4 A local stress diagram of a second lens is shown, which satisfies (CT1+CT2) / T12=1.25, EP01 / CT1=4.32, and |D1s-D2s| / EP12=0.26, according to another optional example of this application.

[0026] Figure 5 The following is an alternative example of the second lens local stress diagram that satisfies (CT1+CT2) / T12=1.25, EP01 / CT1=4.60, and |D1s-D2s| / EP12=0.87;

[0027] Figure 6 The following is an alternative example of the second lens local stress diagram that satisfies (CT1+CT2) / T12=1.25, EP01 / CT1=5.21, and |D1s-D2s| / EP12=1.02;

[0028] Figure 7 A partial structural schematic diagram of the optical imaging lens of Embodiment 1-1 of this application is shown;

[0029] Figure 8 A partial structural schematic diagram of the optical imaging lens of Embodiments 1-2 of this application is shown;

[0030] Figure 9 A partial structural schematic diagram of the optical imaging lens of Embodiments 1-3 of this application is shown;

[0031] Figure 10 The on-axis chromatic aberration curve of the optical imaging lens of Embodiment 1 of this application is shown;

[0032] Figure 11 The astigmatism curve of the optical imaging lens of Embodiment 1 of this application is shown;

[0033] Figure 12 The distortion curve of the optical imaging lens of Embodiment 1 of this application is shown;

[0034] Figure 13 A partial structural schematic diagram of the optical imaging lens of Embodiment 2-1 of this application is shown;

[0035] Figure 14 A partial structural schematic diagram of the optical imaging lens of Embodiment 2-2 of this application is shown;

[0036] Figure 15 A partial structural schematic diagram of the optical imaging lens of Embodiments 2-3 of this application is shown;

[0037] Figure 16 The on-axis chromatic aberration curve of the optical imaging lens of Embodiment 2 of this application is shown;

[0038] Figure 17 The astigmatism curve of the optical imaging lens of Embodiment 2 of this application is shown;

[0039] Figure 18 The distortion curve of the optical imaging lens of Embodiment 2 of this application is shown;

[0040] Figure 19 A partial structural schematic diagram of the optical imaging lens of Embodiment 3-1 of this application is shown;

[0041] Figure 20 A partial structural schematic diagram of the optical imaging lens of Embodiment 3-2 of this application is shown;

[0042] Figure 21 A partial structural schematic diagram of the optical imaging lens of Embodiment 3-3 of this application is shown;

[0043] Figure 22 The on-axis chromatic aberration curve of the optical imaging lens of Embodiment 3 of this application is shown;

[0044] Figure 23 The astigmatism curve of the optical imaging lens of Embodiment 3 of this application is shown;

[0045] Figure 24 The distortion curve of the optical imaging lens of Embodiment 3 of this application is shown. Detailed Implementation

[0046] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] It should be understood that the terms "comprising" and "including" used in the specification and claims of this application indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0048] It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application. As used in this specification and claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this specification and claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations.

[0049] As used in this specification and claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if [described condition or event] is detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once [described condition or event] is detected," or "in response to detection of [described condition or event]."

[0050] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0051] In this application, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not intended to limit this application.

[0052] 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 feature.

[0053] 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 drawn strictly to scale.

[0054] In this specification, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of that 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 that concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface shape of the paraxial region is determined by the sign of the R value (R refers to the radius of curvature of the paraxial region, usually the R value in the lens data database of optical software). For the object side, a positive R value indicates a convex surface, and a negative R value indicates a concave surface; for the image side, a positive R value indicates a concave surface, and a negative R value indicates a convex surface.

[0055] In this application, the object side refers to the side of the optical imaging lens facing the object being photographed (not shown in the figure), and the image side refers to the side of the optical imaging lens facing the imaging plane. In the following text, the object side of a lens refers to the surface of the lens facing the object being photographed (not shown in the figure), and the image side of a lens refers to the surface of the lens facing the imaging plane.

[0056] To facilitate understanding, let's first combine... Figure 1 and Figure 2 The various components and dimensions of the optical imaging lens mentioned below will be described in detail. For ease of description, the surface shape of the optical imaging lens and specific lenses will be described in specific embodiments later, and these parameters will not be shown here.

[0057] like Figure 1As shown, E1 is the first lens, E2 is the second lens, E3 is the third lens, E4 is the fourth lens, E5 is the fifth lens, E6 is the sixth lens, E7 is the seventh lens, and E8 is the eighth lens; P0 is the lens barrel, P1 is the first spacer element, P2 is the second spacer element, P2b is the second auxiliary spacer element, P3 is the third spacer element, P4 is the fourth spacer element, P5 is the fifth spacer element, P6 is the sixth spacer element, P7 is the seventh spacer element, P7b is the seventh auxiliary spacer element, and P8 is the eighth spacer element; S1 is the object side of the first lens. S11 is the object-side surface of the first lens, S2 is the image-side surface of the second lens, S3 is the object-side surface of the second lens, S4 is the image-side surface of the second lens, S5 is the object-side surface of the third lens, S6 is the image-side surface of the third lens, S7 is the object-side surface of the fourth lens, S8 is the image-side surface of the fourth lens, S9 is the object-side surface of the fifth lens, S10 is the image-side surface of the fifth lens, S11 is the object-side surface of the sixth lens, S12 is the image-side surface of the sixth lens, S13 is the object-side surface of the seventh lens, S14 is the image-side surface of the seventh lens, S15 is the object-side surface of the eighth lens, S16 is the image-side surface of the eighth lens, S17 and S18 are the object-side surface and image-side surface of the filter or protective glass, respectively, and S19 is the imaging surface.

[0058] like Figure 2 As shown, EP01 is the distance along the optical axis from the object side of the lens barrel to the object side of the first spacer element; EP45 is the distance along the optical axis from the image side of the fourth spacer element to the object side of the fifth spacer element; and EP67 is the distance along the optical axis from the image side of the sixth spacer element to the object side of the seventh spacer element.

[0059] d1s is the inner diameter of the object side of the first spacer element, 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, d2bs is the inner diameter of the object side of the second auxiliary spacer element, d5s is the inner diameter of the object side of the fifth spacer element, d7s is the inner diameter of the object side of the seventh spacer element, d7bs is the inner diameter of the object side of the seventh auxiliary spacer element, and d8m is the inner diameter of the image side of the eighth spacer element.

[0060] D0s is the outer diameter of the object side of the lens barrel, 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, D2bs is the outer diameter of the object side of the second auxiliary spacer element, D3s is the outer diameter of the object side of the third spacer element, D4s is the outer diameter of the object side of the fourth spacer element, D4m is the outer diameter of the image side of the fourth spacer element, D5s is the outer diameter of the object side of the fifth lens, and D0m is the outer diameter of the image side of the lens barrel.

[0061] L is the maximum height of the lens barrel, CP2 is the maximum thickness of the second spacer element along the optical axis, and CP7 is the maximum thickness of the seventh spacer element along the optical axis.

[0062] It should be noted that embodiments of this application may also include those without bonding. Figure 1 and Figure 2 Other components and dimensions described herein will not be repeated here. Furthermore, the optical axis mentioned above and below specifically refers to the central axis of symmetry of the optical imaging lens, around which all lenses are arranged coaxially. The axial distance mentioned above and below refers to the direction of the optical axis of the optical imaging lens, the straight-line distance between two optical surfaces (or structural features).

[0063] Next, the optical imaging lens provided in this application will be described in detail. The optical imaging lens includes a lens barrel and a lens group and a plurality of spacer elements disposed in the lens barrel. The lens group consists of eight lenses. Each of the first to eighth lenses has at least an object-side surface facing the subject and an image-side surface facing the imaging surface. At least one spacer element is provided between any two adjacent lenses.

[0064] The eight lenses, arranged sequentially along the optical axis from the object side to the image side, include: a first lens with negative optical power, whose image side is concave; a second lens with positive optical power; a third lens with either positive or negative optical power, whose object side is convex and image side is concave; a fourth lens with positive optical power, whose object side and image side are both convex; a fifth lens with positive optical power, whose image side is convex; a sixth lens with positive optical power, whose image side is convex; a seventh lens with negative optical power, whose image side is concave; and an eighth lens with negative optical power, whose object side is convex and image side is concave.

[0065] The plurality of spacers include a first spacer and a second spacer. The first spacer is disposed between the first lens and the second lens, and the object side of the first spacer is in contact with the image side of the first lens. The second spacer is disposed between the second lens and the third lens, and the object side of the second spacer is in contact with the image side of the second lens.

[0066] Meanwhile, the following conditions are met: the center thickness CT1 of the first lens, the center thickness CT2 of the second lens, and the air gap T12 between the first and second lenses on the optical axis satisfy: 1.00 < (CT1 + CT2) / T12 ≤ 1.70; the distance EP01 from the object side of the lens barrel to the object side of the first spacer element along the optical axis, and the center thickness CT1 of the first lens satisfy: 4.10 ≤ EP01 / CT1 ≤ 4.87; the outer diameter D1s of the object side of the first spacer element, the outer diameter D2s of the object side of the second spacer element, and the distance EP12 from the image side of the first spacer element to the object side of the second spacer element along the optical axis satisfy: 0.11 ≤ |D1s - D2s| / EP12 < 0.90.

[0067] Next, refer to Figures 3 to 6To understand the impact of different values ​​of the condition EP01 / CT1 and |D1s-D2s| / EP12 on the local stress of the second lens during assembly, under the premise that the optical imaging lens satisfies 1.00 < (CT1+CT2) / T12 ≤ 1.70, for example, (CT1+CT2) / T12 = 1.25.

[0068] Figure 3 A local stress diagram of a second lens, representing an optional example of this application, is shown. Specifically, in this embodiment, the optical imaging lens satisfies EP01 / CT1 = 3.86 and |D1s-D2s| / EP12 = 0.05, exceeding the lower limits of the aforementioned conditional expressions 4.10 ≤ EP01 / CT1 ≤ 4.87 and 0.11 ≤ |D1s-D2s| / EP12 < 0.90. This example is hereinafter referred to as Example 1. Figure 3 As can be seen in Example 1, when (CT1+CT2) / T12=1.25, EP01 / CT1=3.86, and |D1s-D2s| / EP12=0.05, the maximum stress of the second lens is 3.702MPa, which is greater than 3MPa, indicating excessive local stress in the lens. Therefore, when the fit is greater than 0.005mm, there is a risk of cracking of the second lens during assembly.

[0069] Figure 4 A local stress diagram of the second lens, representing another alternative example of this application, is shown. Specifically, in this embodiment, the optical imaging lens satisfies EP01 / CT1 = 4.32 and |D1s-D2s| / EP12 = 0.26, that is, it satisfies the above conditions 4.10 ≤ EP01 / CT1 ≤ 4.87 and 0.11 ≤ |D1s-D2s| / EP12 < 0.90. This example is hereinafter referred to as Example 2. Figure 4 As can be seen in Example 2, when (CT1+CT2) / T12=1.25, EP01 / CT1=4.32, and |D1s-D2s| / EP12=0.26, with a fitting allowance of 0.005mm, the maximum stress of the second lens is 0.825MPa, which is less than 3MPa, and the overall stress of the lens is relatively uniform. Therefore, when the fitting allowance is greater than 0.005mm, there is no risk of the second lens cracking during assembly.

[0070] Figure 5 A second lens local stress diagram of another optional example of this application is shown. Specifically, in this embodiment, the optical imaging lens satisfies EP01 / CT1=4.60, |D1s-D2s| / EP12=0.87, that is, it satisfies the above conditions 4.10≤EP01 / CT1≤4.87 and 0.11≤|D1s-D2s| / EP12<0.90. This example is hereinafter referred to as Example 3. Figure 5As can be seen in Example 3, when (CT1+CT2) / T12=1.25, EP01 / CT1=4.60, and |D1s-D2s| / EP12=0.87, with a fitting allowance of 0.005mm, the maximum stress of the second lens is 1.794MPa, which is less than 3MPa, indicating that the overall stress of the lens is relatively uniform. Therefore, when the fitting allowance is greater than 0.005mm, there is no risk of the second lens cracking during assembly.

[0071] Figure 6 A second lens local stress diagram of another optional example of this application is shown. Specifically, in this embodiment, the optical imaging lens satisfies EP01 / CT1=5.21, |D1s-D2s| / EP12=1.02, which exceeds the upper limit of the above-mentioned conditional expressions 4.10≤EP01 / CT1≤4.87 and 0.11≤|D1s-D2s| / EP12<0.90. This example is hereinafter referred to as Example 4. Figure 5 As can be seen in Example 4, when (CT1+CT2) / T12=1.25, EP01 / CT1=5.21, and |D1s-D2s| / EP12=1.02, the maximum stress of the second lens is 4.166MPa, which is greater than 3MPa, indicating excessive local stress in the lens. Therefore, when the fit is greater than 0.005mm, there is a risk of cracking of the second lens during assembly.

[0072] The optical imaging lens of this application comprises eight lenses arranged sequentially along the optical axis, each with a specific optical power and surface shape. At least one spacer element is placed between any two adjacent lenses. The first and second spacers are located between the first and second lenses, and between the second and third lenses, respectively, and are in contact with the corresponding lens portions. Simultaneously, 1.00 < (CT1 + CT2) / T12 ≤ 1.70 provides a reference for the axial positioning of the first and second lenses. 4.10 ≤ EP01 / CT1 ≤ 4.87 and 0.11 ≤ |D1s - D2s| / EP12 < 0.90 guide the front end of the lens barrel. The tapered or stepped design simplifies the lens barrel manufacturing process and ensures that the inner diameter of the lens barrel matches the dimensions of the first lens and spacer elements, reducing assembly difficulties or component interference caused by size mismatch. At the same time, it can optimize the outer diameter difference of the spacer elements, enhance the mechanical strength of the spacer elements, and effectively optimize the situation where the local stress of the second lens is too large due to the excessive fit between the first and second spacer elements during assembly. It also reduces lens deformation or damage caused by external forces, thereby solving the assembly stability challenge faced by eight-element optical imaging lenses due to the increase in the number of lenses, ensuring that the lens maintains stable performance during assembly, and improving the lens assembly performance and production yield.

[0073] In some embodiments of this application, the outer diameter D2s of the object side of the aforementioned second spacer element, the inner diameter d2s of the object side of the second spacer element, and the maximum thickness CP2 of the second spacer element along the optical axis satisfy the following ratio: 2.35 < (D2s - d2s) / CP2 ≤ 10.72. This proportional relationship can effectively control the ratio of the difference between the inner and outer diameters of the second spacer element to the maximum thickness, ensuring sufficient mechanical strength of the second spacer element. This ensures structural stability under external forces (such as vibration or impact) or thermal stress caused by temperature changes, thereby maintaining the relative positional accuracy between optical elements and ultimately ensuring the imaging quality of the optical system.

[0074] In some embodiments of this application, the air gap T23 between the second and third lenses on the optical axis, and the maximum thickness CP2 of the second spacer element along the optical axis, satisfy the following ratio: 0.57 ≤ T23 / CP2 < 1.85. By limiting the ratio of T23 to CP to between 0.57 and 1.85, a coordinated adaptation between the air gap and the thickness of the spacer element can be achieved. If the ratio is less than 0.57, the air gap will be too short or the spacer element will be too thick, easily leading to optical path restriction between the two lenses and stress concentration during thermal expansion. If the ratio is greater than or equal to 1.85, the air gap will be too long or the spacer element will be too thin, making it difficult to maintain optical axis alignment accuracy. This proportional control can effectively balance the effects of thermal expansion and mechanical stress, ensuring that the coordinated change of the spacer element thickness and the air gap always maintains optical axis alignment accuracy, thereby guaranteeing imaging quality.

[0075] In some embodiments of this application, the plurality of spacers further includes a second auxiliary spacer. The second auxiliary spacer is provided to further refine the axial positioning accuracy between the second lens and the third lens, share the supporting pressure of a single spacer, and form a more stable assembly structure. Specifically, the second auxiliary spacer is disposed between the second spacer and the third lens, and the object side of the second auxiliary spacer is in contact with the image side of the second spacer.

[0076] Furthermore, the outer diameter D2bs of the object side of the second auxiliary spacer element, the inner diameter d2bs of the object side of the second auxiliary spacer element, the outer diameter D2m of the image side of the second spacer element, and the inner diameter d2m of the image side of the second spacer element satisfy the following ratio: 3.30 < (D2bs - d2bs) / (D2m - d2m) < 5.15. This proportional relationship ensures that the second spacer element and the second auxiliary spacer element have sufficient mechanical strength to jointly resist external forces such as vibration and impact, preventing deformation or damage due to insufficient strength of one component, and ensuring that the optical performance of the lens is not affected. At the same time, this matching of structural strengths also makes it easier to achieve coaxial alignment during assembly, reducing assembly errors caused by size mismatch and effectively improving the overall assembly yield of the lens.

[0077] In some embodiments of this application, the multiple spacer elements further include a third spacer element and a fourth spacer element. The third lens and the fourth lens are key aberration correction units in the lens group. The third spacer element is disposed between them to maintain the relative position stability of the two lenses and ensure that their aberration correction function works normally. The fourth lens and the fifth lens play an important role in light convergence. The fourth spacer element is disposed between them to avoid optical surface damage or performance impairment caused by direct contact between the two lenses. Specifically, the assembly relationship is as follows: the third spacer element is disposed between the third lens and the fourth lens, and the object side of the third spacer element is in contact with the image side of the third lens; the fourth spacer element is disposed between the fourth lens and the fifth lens, and the object side of the fourth spacer element is in contact with the image side of the fourth lens.

[0078] Furthermore, the outer diameter of the object side of the fourth spacer element (D4s), the outer diameter of the image side of the third spacer element (D3m), and the combined focal length of the third and fourth lenses (f34) satisfy the following condition: 2.45 < (D4s + D3m) / f34 ≤ 3.51. When this condition is limited to between 2.45 and 3.50, the radial dimension of the spacer element and the combined focal length of the lenses can be matched, guiding light rays from different fields of view to enter and exit the two lenses at appropriate angles, avoiding energy loss due to excessive divergence or aberrations such as spherical aberration and field curvature caused by excessive convergence. This optimization allows light rays to converge accurately on the imaging plane, improving image sharpness while reducing stray light generation and improving light utilization efficiency.

[0079] In some embodiments of this application, the plurality of spacers further includes a fifth spacer element; the fifth spacer element is disposed between the fifth lens and the sixth lens, and the object-side surface of the fifth spacer element is in contact with the image-side surface of the fifth lens. Simultaneously, the outer diameter D4m of the image-side surface of the fourth spacer element, the outer diameter D5s of the object-side surface of the fifth lens, and the distance EP45 from the image-side surface of the fourth spacer element to the object-side surface of the fifth spacer element along the optical axis satisfy the following condition: 2.00 ≤ EP45 / (D4m-D5s) < 9.30. This ratio condition has an adjusting effect on the focusing of light in the meridional and sagittal planes. A suitable ratio can balance aberrations on these two planes, correct astigmatism and field curvature, and ensure that the image maintains a clear and accurate shape under different viewing fields; at the same time, it can ensure the stability of the focal length during the design and use of the lens, avoid focal length drift caused by changes in structural parameters, optimize the assembly process, prevent loose lens structure, ensure mechanical strength, and reduce the impact of assembly tolerances on light performance.

[0080] In some embodiments of this application, the effective focal length f5 of the fifth lens and the inner diameter d5s of the object-side surface of the fifth spacer element satisfy the condition 1.59 ≤ f5 / d5s < 3.60. If this ratio is too large, i.e., the effective focal length f5 is too large or the inner diameter d5s of the object-side surface of the fifth spacer element is too small, it will restrict the passage of edge light and cause vignetting, affecting image sharpness. If this ratio is too small, i.e., the effective focal length f5 is too small or the inner diameter d5s of the fifth spacer element is too large, it will weaken the light-blocking effect at that position and increase the risk of stray light. By controlling this ratio between 1.59 and 3.60, the optical path convergence of the fifth lens can be moderate, ensuring the correction effect of aberrations such as spherical aberration and coma, thereby ensuring the clarity and uniformity of the imaging quality across the entire field of view.

[0081] In some embodiments of this application, the plurality of spacers further include a sixth spacer and a seventh spacer; the sixth lens is a positive power lens, which performs the function of further converging light rays; the sixth spacer is disposed between the sixth lens and the seventh lens, and the object side of the sixth spacer is in contact with the image side of the sixth lens to maintain the relative position stability of the two lenses; the seventh lens is a negative power lens, which is used to correct the aberrations generated by the preceding lens; both the seventh lens and the eighth lens are negative power lenses; the seventh spacer is disposed between the seventh lens and the eighth lens, and the object side of the seventh spacer is in contact with the image side of the seventh lens to avoid the superposition of aberrations caused by direct contact between the two lenses.

[0082] Simultaneously, the following conditions must be met: the distance EP67 between the image side of the sixth spacer element and the object side of the seventh spacer element along the optical axis; the maximum thickness CP7 of the seventh spacer element along the optical axis; the air gap T67 between the sixth and seventh lenses along the optical axis; and the center thickness CT7 of the seventh lens: 2.10 < (EP67 + CP7) / (T67 + CT7) < 3.75. By controlling this conditional expression, the propagation path of light in the lens can be optimized, allowing for more rational distribution and focusing of light, thus improving imaging performance. Furthermore, it ensures the stable support and fixation of the sixth and seventh spacer elements, as well as the sixth and seventh lenses, within the lens, preventing displacement or tilting during use, thereby ensuring that the optical performance of the lens remains unaffected. In addition, a reasonable proportion provides positioning and guidance during assembly, reducing assembly errors.

[0083] In some embodiments of this application, the radius of curvature R15 of the object side of the eighth lens, the radius of curvature R16 of the image side of the eighth lens, and the center thickness CT8 of the eighth lens satisfy the following: 22.89≤(R15+R16) / CT8≤27.88; the inner diameter d7s of the object side of the seventh spacer element and the radius of curvature R15 of the object side of the eighth lens satisfy the following: 0.50≤d7s / R15≤1.58.

[0084] Given that the object-side surface of the eighth lens is convex and the image-side surface is concave, its structural parameters are crucial to the overall optical performance and assembly stability as the last lens in the lens group. Controlling the ratio of (R15+R16) to CT8 between 22.89 and 27.88 ensures that the eighth lens is less prone to warping or cracking during manufacturing, balancing manufacturing feasibility and structural strength. This also ensures a more uniform stress distribution under external forces, reducing deformation or damage caused by stress concentration. While ensuring the manufacturing feasibility of the eighth lens, to avoid interference with the seventh spacer element, controlling the ratio of d7s to R15 between 0.50 and 1.58 ensures that the inner diameter of the seventh spacer element matches the curvature of the object-side surface of the eighth lens, allowing for proper installation inside the lens. This avoids component interference or installation difficulties due to dimensional mismatch, effectively improving assembly yield.

[0085] In some embodiments of this application, the maximum height L of the lens barrel and the distance Tr7r12 on the optical axis from the object side of the fourth lens to the image side of the sixth lens satisfy the following ratio: 3.90 < L / Tr7r12 < 4.75. This ratio helps to rationally arrange the spatial positions of the components inside the lens while meeting optical performance requirements: if the ratio is too small, it will lead to insufficient lens barrel space, which may easily cause interference and collision between the lens barrel and the lens and spacer elements; if the ratio is too large, it will cause waste of lens barrel space, which is not conducive to lens miniaturization. Controlling the ratio between 3.90 and 4.75 can maintain an appropriate distance between the lens barrel and other components, which can avoid component interference and realize the miniaturization and compact design of the lens, which is in line with the development trend of thinner and lighter electronic devices.

[0086] In some embodiments of this application, the plurality of spacers further includes a seventh auxiliary spacer. The seventh auxiliary spacer is used to further refine the axial positioning accuracy between the seventh and eighth lenses, avoiding instability issues that may occur with a single spacer support. In this case, the seventh auxiliary spacer is positioned between the seventh and eighth lenses, with the object-side surface of the seventh auxiliary spacer in contact with the image-side surface of the seventh spacer. Simultaneously, the radius of curvature R14 of the image-side surface of the seventh lens and the inner diameter d7bs of the object-side surface of the seventh auxiliary spacer satisfy the following ratio: 0.53 ≤ R14 / d7bs < 1.60. This ratio controls the refraction path of light after passing through the seventh lens, effectively reducing spherical aberration. Specifically, a suitable ratio avoids abnormal light refraction caused by R14 being too large or too small, ensuring that light can be transmitted to the eighth lens along a preset path, thereby guaranteeing image clarity and reducing blurring and distortion at image edges.

[0087] In some embodiments of this application, the effective focal length f7 of the seventh lens and the maximum thickness CP7 of the seventh spacer element along the optical axis satisfy the condition -15.40 < f7 / CP7 ≤ -7.24. It is known that the seventh lens has a negative optical power, and light rays diverge after passing through it. If the absolute value of f7 is too small, the divergence will be too strong, potentially causing structural interference with surrounding components and overcorrecting aberrations of preceding lenses. If the absolute value of f7 is too large, the divergence will be insufficient, failing to effectively counteract the converging effect of preceding lenses and resulting in residual aberrations. By controlling the ratio of f7 to CP7 between -15.40 and -7.24, the divergence capability of the seventh lens can be matched with the support thickness of the seventh spacer element. This optimizes the correction effect of aberrations such as spherical aberration and coma through reasonable divergence, avoids structural interference caused by excessive divergence, and ensures stable support of the seventh lens by the seventh spacer element, guaranteeing a smooth optical path.

[0088] In some embodiments of this application, the plurality of spacers further includes an eighth spacer. The eighth spacer is disposed on the image side of the eighth lens, and the object side of the eighth spacer partially contacts the image side of the eighth lens, serving to protect the optical surface of the eighth lens and simultaneously assisting in fixing the overall position of the lens group within the lens barrel. Simultaneously, the inner diameter d8m of the image side of the eighth spacer, the inner diameter d1s of the object side of the first spacer, and the effective focal length f of the optical imaging lens satisfy the following condition: 1.55 < (d8m - d1s) / f ≤ 2.16. This conditional expression allows control over the size of the incident and exit apertures of light, guiding light transmission along a preset path. A reasonable proportional range effectively suppresses field curvature and astigmatism, reducing image edge blurring caused by field curvature and image distortion caused by astigmatism. Simultaneously, it balances the edge illumination and central field resolution of the optical path, ensuring consistent imaging quality across the entire field of view and guaranteeing a clear and uniform image.

[0089] In some embodiments of this application, the axial distance TD between the object-side surface of the first lens and the image-side surface of the eighth lens, the outer diameter D0m of the image-side surface of the lens barrel, and the outer diameter D0s of the object-side surface of the lens barrel satisfy the following ratio: 2.13 ≤ TD / (D0m-D0s) ≤ 8.75. This ratio allows for a gradually expanding design of the lens barrel, enabling it to adapt to different lens arrangement requirements: when the ratio is between 2.13 and 8.75, the internal space of the lens barrel can be maximized, making the layout of components such as lenses and spacers more reasonable and reducing space waste or component interference; at the same time, this gradually expanding structure can also effectively buffer the influence of temperature and humidity changes on the lens barrel and lenses, ensuring that both have stable dimensions and performance under different environments, reducing structural deformation caused by thermal expansion and contraction, and improving the reliability of the lens.

[0090] The following description, with reference to the accompanying drawings, further illustrates examples of specific surface shapes and parameters of optical imaging lenses applicable to the above embodiments.

[0091] It should be noted that in the following Embodiment 1, there are three examples: Embodiment 1-1, Embodiment 1-2, and Embodiment 1-3; in Embodiment 2, there are three examples: Embodiment 2-1, Embodiment 2-2, and Embodiment 2-3; and in Embodiment 3, there are three examples: Embodiment 3-1, Embodiment 3-2, and Embodiment 3-3. In the three examples within the same embodiment, the optical imaging lens has the same optical parameters, that is, the basic optical parameter table and the aspherical higher-order coefficient table are the same. However, the structural parameters are different, that is, the dimensional values ​​of some structural parameters of the lens barrel and multiple spacer elements in the optical imaging lens are different.

[0092] It should be noted that any one of the examples in Embodiments 1 to 3 described below is applicable to all implementations of this application.

[0093] Example 1

[0094] Figure 7 A partial structural schematic diagram of the optical imaging lens of Embodiment 1-1 is shown. Figure 8 A partial structural schematic diagram of the optical imaging lens of Embodiments 1-2 is shown. Figure 9 A partial structural schematic diagram of the optical imaging lens of Embodiments 1-3 is shown.

[0095] like Figures 7 to 9 As shown, the optical imaging lens includes a lens barrel P0 and a first lens E1, a first spacer P1, a second lens E2, a second spacer P2, a second auxiliary spacer P2b, a third lens E3, a third spacer P3, a fourth lens E4, a fourth spacer P4, a fifth lens E5, a fifth spacer P5, a sixth lens E6, a sixth spacer P6, a seventh lens E7, a seventh spacer P7, a seventh auxiliary spacer P7b, an eighth lens E8, and an eighth spacer P8, arranged sequentially along the optical axis from the object side to the image side in the lens barrel P0.

[0096] like Figure 7The diagram shows a partial structural schematic of the optical imaging lens in Embodiment 1-1. In this example, the first spacer element P1 is disposed between the first lens E1 and the second lens E2, and the object-side surface of the first spacer element P1 is in contact with the image-side surface S2 of the first lens. The second spacer element P2 is disposed between the second lens E2 and the third lens E3, and the object-side surface of the second spacer element P2 is in contact with the image-side surface S4 of the second lens. The second auxiliary spacer element P2b is disposed between the second spacer element P2 and the third lens E3, and the object-side surface of the second auxiliary spacer element P2b is in contact with the image-side surface of the second spacer element P2. The third spacer element P3 is disposed between the third lens E3 and the fourth lens E4, and the object-side surface of the third spacer element P3 is in contact with the image-side surface S6 of the third lens. The fourth spacer element P4 is disposed between the fourth lens E4 and the fifth lens E5, and the object-side surface of the fourth spacer element P4 is in contact with the image-side surface S8 of the fourth lens. The fifth spacer element P5 is disposed between the fifth lens E5 and the sixth lens E6, and the object-side surface of the fifth spacer element P5 is in contact with the image-side surface S10 of the fifth lens. The sixth spacer element P6 is disposed between the sixth lens E6 and the seventh lens E7, and the object-side surface of the sixth spacer element P6 is in contact with the image-side surface S12 of the sixth lens. The seventh spacer element P7 is disposed between the seventh lens E7 and the eighth lens E8, and the object-side surface of the seventh spacer element P7 is in contact with the image-side surface S14 of the seventh lens. The seventh auxiliary spacer element P7b is disposed between the seventh spacer element P7 and the eighth lens E8, and the object-side surface of the seventh auxiliary spacer element P7b is in contact with the image-side surface of the seventh spacer element P7. The eighth spacer element P8 is disposed on the image side of the eighth lens E8, and the object-side surface of the eighth spacer element P8 is in contact with the image-side surface S16 of the eighth lens.

[0097] It is understood that the contact method of each spacer element in Embodiments 1-2 and 1-3 is the same as that in Embodiment 1-1, and can be referred to the relevant description in Embodiment 1-1, which will not be repeated here. Table 1 below shows the basic optical parameters of the optical imaging lens of Embodiment 1 under Embodiments 1-1, 1-2, and 1-3, where the units of radius of curvature and thickness / distance are millimeters (mm). In Table 1, OBJ (not shown in the figure) is the object plane, STO (not shown in the figure) is the aperture, and the aperture is located between the second lens E2 and the third lens E3. S17 and S18 (as shown in the figure) Figure 7 As shown in the figures (other figures omitted), S19 represents the object side and image side of the filter or protective glass, respectively. Figure 7 As shown in the figure (other figures omitted), this is the imaging plane.

[0098] Table 1

[0099]

[0100] As shown in Table 1, in Embodiment 1, the object-side and image-side surfaces of the first lens E1 to the eighth lens E8 are all aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0101] Formula (1)

[0102] Where x is the distance vector from the vertex of the aspherical surface along the optical axis at a height of h; c is the paraxial curvature of the aspherical surface, c=1 / R, that is, the paraxial curvature c is the reciprocal of the radius of curvature R in Table 1 above; k is the conic coefficient. These are the correction coefficients of the i-th order for aspherical surfaces. Tables 2-1 and 2-2 below give the higher-order coefficients A4, A6...A20 that can be used for each aspherical mirror S1-S16 in Example 1.

[0103] Table 2-1

[0104]

[0105] Table 2-2

[0106]

[0107] In Embodiment 1, the first lens E1 has negative optical power, the second lens E2 has positive optical power, the third lens E3 has positive optical power, the fourth lens E4 has positive optical power, the fifth lens E5 has positive optical power, the sixth lens E6 has positive optical power, the seventh lens E7 has negative optical power, and the eighth lens E8 has negative optical power. The optical parameters of the optical imaging lens in Embodiment 1 under Embodiments 1-1, 1-2, and 1-3 are shown in Table 7 below (unit: mm), the structural parameters are shown in Table 8 below (unit: mm), and the values ​​of each conditional expression are shown in Table 9 below.

[0108] Figure 10 The on-axis chromatic aberration curve of the optical imaging lens of Embodiment 1 is shown, which represents the deflection of the focal point of light of different wavelengths after passing through the optical imaging lens. Figure 11 The astigmatism curve of the optical imaging lens of Embodiment 1 is shown, which represents the curvature of the meridional and sagittal image planes. Figure 12 The distortion curve of the optical imaging lens of Embodiment 1 is shown, representing the distortion magnitude corresponding to different image heights. Figures 10 to 12 As can be seen, the on-axis chromatic aberration, astigmatism, and distortion are well controlled, and the optical imaging lens given in Example 1 can achieve good imaging quality.

[0109] Example 2

[0110] Figure 13 A schematic diagram of the optical imaging lens of Embodiment 2-1 is shown. Figure 14 A schematic diagram of the optical imaging lens of Embodiment 2-2 is shown. Figure 15 A schematic diagram of the optical imaging lens of Embodiments 2-3 is shown.

[0111] like Figures 13 to 15 As shown, the optical imaging lens includes a lens barrel P0 and a first lens E1, a first spacer P1, a second lens E2, a second spacer P2, a second auxiliary spacer P2b, a third lens E3, a third spacer P3, a fourth lens E4, a fourth spacer P4, a fifth lens E5, a fifth spacer P5, a sixth lens E6, a sixth spacer P6, a seventh lens E7, a seventh spacer P7, a seventh auxiliary spacer P7b, an eighth lens E8, and an eighth spacer P8, arranged sequentially along the optical axis from the object side to the image side in the lens barrel P0.

[0112] like Figure 13 The diagram shows a partial structural schematic of the optical imaging lens in Embodiment 2-1. In this example, the first spacer element P1 is disposed between the first lens E1 and the second lens E2, and the object-side surface of the first spacer element P1 is in contact with the image-side surface S2 of the first lens. The second spacer element P2 is disposed between the second lens E2 and the third lens E3, and the object-side surface of the second spacer element P2 is in contact with the image-side surface S4 of the second lens. The second auxiliary spacer element P2b is disposed between the second spacer element P2 and the third lens E3, and the object-side surface of the second auxiliary spacer element P2b is in contact with the image-side surface of the second spacer element P2. The third spacer element P3 is disposed between the third lens E3 and the fourth lens E4, and the object-side surface of the third spacer element P3 is in contact with the image-side surface S6 of the third lens. The fourth spacer element P4 is disposed between the fourth lens E4 and the fifth lens E5, and the object-side surface of the fourth spacer element P4 is in contact with the image-side surface S8 of the fourth lens. The fifth spacer element P5 is disposed between the fifth lens E5 and the sixth lens E6, and the object-side surface of the fifth spacer element P5 is in contact with the image-side surface S10 of the fifth lens. The sixth spacer element P6 is disposed between the sixth lens E6 and the seventh lens E7, and the object-side surface of the sixth spacer element P6 is in contact with the image-side surface S12 of the sixth lens. The seventh spacer element P7 is disposed between the seventh lens E7 and the eighth lens E8, and the object-side surface of the seventh spacer element P7 is in contact with the image-side surface S14 of the seventh lens. The seventh auxiliary spacer element P7b is disposed between the seventh spacer element P7 and the eighth lens E8, and the object-side surface of the seventh auxiliary spacer element P7b is in contact with the image-side surface of the seventh spacer element P7. The eighth spacer element P8 is disposed on the image side of the eighth lens E8, and the object-side surface of the eighth spacer element P8 is in contact with the image-side surface S16 of the eighth lens.

[0113] It is understood that the contact method of each spacer element in Embodiments 2-2 and 2-3 is the same as that in Embodiment 2-1, and can be referred to the relevant description in Embodiment 2-1, which will not be repeated here. Table 3 below shows the basic optical parameters of the optical imaging lens of Embodiment 2, in which the units of radius of curvature and thickness / distance are millimeters (mm). In Table 3, OBJ (not shown in the figure) is the object plane, STO (not shown in the figure) is the aperture, and the aperture is located between the third lens and the fourth lens. S17 and S18 are the object side and image side of the filter or protective glass, respectively, and S19 is the imaging plane.

[0114] Table 3

[0115]

[0116] As shown in Table 3, in Embodiment 2, the object-side surface and image-side surface of the first lens E1 to the eighth lens E8 are both aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the aforementioned formula (1). Tables 4-1 and 4-2 below give the higher-order coefficients A4, A6...A20 that can be used for each aspherical mirror S1-S16 in Embodiment 2.

[0117] Table 4-1

[0118]

[0119] Table 4-2

[0120]

[0121] In Embodiment 2, the first lens E1 has negative optical power, the second lens E2 has positive optical power, the third lens E3 has negative optical power, the fourth lens E4 has positive optical power, the fifth lens E5 has positive optical power, the sixth lens E6 has positive optical power, the seventh lens has negative optical power, and the eighth lens has negative optical power. The optical parameters of the optical imaging lens in Embodiment 2 under Embodiments 2-1, 2-2, and 2-3 are shown in Table 7 below (unit: mm), the structural parameters are shown in Table 8 below (unit: mm), and the values ​​of each conditional expression are shown in Table 9 below.

[0122] Figure 16 The on-axis chromatic aberration curve of the optical imaging lens of Embodiment 2 is shown, which indicates the deviation of the focal point of light of different wavelengths after passing through the optical imaging lens. Figure 17 The astigmatism curve of the optical imaging lens of Embodiment 2 is shown, which represents the curvature of the meridional and sagittal image planes. Figure 18 The distortion curve of the optical imaging lens in Embodiment 2 is shown, representing the distortion magnitude corresponding to different half-field angles. According to... Figures 16 to 18As can be seen, the curves are balanced, and chromatic aberration, astigmatism and distortion are well controlled. In other words, the optical imaging lens given in Example 2 can achieve good imaging quality.

[0123] Example 3

[0124] Figure 19 A schematic diagram of the optical imaging lens of Embodiment 3-1 is shown. Figure 20 A schematic diagram of the optical imaging lens of Embodiment 3-2 is shown. Figure 21 A schematic diagram of the optical imaging lens of Embodiment 3-3 is shown.

[0125] like Figures 19 to 21 As shown, the optical imaging lens includes a lens barrel P0 and a first lens E1, a first spacer P1, a second lens E2, a second spacer P2, a second auxiliary spacer P2b, a third lens E3, a third spacer P3, a fourth lens E4, a fourth spacer P4, a fifth lens E5, a fifth spacer P5, a sixth lens E6, a sixth spacer P6, a seventh lens E7, a seventh spacer P7, a seventh auxiliary spacer P7b, an eighth lens E8, and an eighth spacer P8, arranged sequentially along the optical axis from the object side to the image side in the lens barrel P0.

[0126] like Figure 19The diagram shows a partial structural schematic of the optical imaging lens in Embodiment 3-1. In this example, the first spacer element P1 is disposed between the first lens E1 and the second lens E2, and the object-side surface of the first spacer element P1 is in contact with the image-side surface S2 of the first lens. The second spacer element P2 is disposed between the second lens E2 and the third lens E3, and the object-side surface of the second spacer element P2 is in contact with the image-side surface S4 of the second lens. The second auxiliary spacer element P2b is disposed between the second spacer element P2 and the third lens E3, and the object-side surface of the second auxiliary spacer element P2b is in contact with the image-side surface of the second spacer element P2. The third spacer element P3 is disposed between the third lens E3 and the fourth lens E4, and the object-side surface of the third spacer element P3 is in contact with the image-side surface S6 of the third lens. The fourth spacer element P4 is disposed between the fourth lens E4 and the fifth lens E5, and the object-side surface of the fourth spacer element P4 is in contact with the image-side surface S8 of the fourth lens. The fifth spacer element P5 is disposed between the fifth lens E5 and the sixth lens E6, and the object-side surface of the fifth spacer element P5 is in contact with the image-side surface S10 of the fifth lens. The sixth spacer element P6 is disposed between the sixth lens E6 and the seventh lens E7, and the object-side surface of the sixth spacer element P6 is in contact with the image-side surface S12 of the sixth lens. The seventh spacer element P7 is disposed between the seventh lens E7 and the eighth lens E8, and the object-side surface of the seventh spacer element P7 is in contact with the image-side surface S14 of the seventh lens. The seventh auxiliary spacer element P7b is disposed between the seventh spacer element P7 and the eighth lens E8, and the object-side surface of the seventh auxiliary spacer element P7b is in contact with the image-side surface of the seventh spacer element P7. The eighth spacer element P8 is disposed on the image side of the eighth lens E8, and the object-side surface of the eighth spacer element P8 is in contact with the image-side surface S16 of the eighth lens.

[0127] It is understood that the contact method of each spacer element in Embodiments 3-2 and 3-3 is the same as that in Embodiment 3-1, and can be referred to the relevant description in Embodiment 3-1, which will not be repeated here. Table 5 below shows the basic optical parameters of the optical imaging lens of Embodiment 3, in which the units of radius of curvature and thickness / distance are millimeters (mm). In Table 5, OBJ (not shown in the figure) is the object plane, STO (not shown in the figure) is the aperture, and the aperture is located between the second lens and the third lens. S17 and S18 are the object side and image side of the filter or protective glass, respectively, and S19 is the imaging plane.

[0128] Table 5

[0129]

[0130] As shown in Table 5, in Embodiment 3, the object-side surface and image-side surface of the first lens E1 to the eighth lens E8 are both aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the aforementioned formula (1). Tables 6-1 and 6-2 below give the higher-order coefficients A4, A6...A20 that can be used for each aspherical mirror S1-S16 in Embodiment 3.

[0131] Table 6-1

[0132]

[0133] Table 6-2

[0134]

[0135] In Embodiment 3, the first lens E1 has negative optical power, the second lens E2 has positive optical power, the third lens E3 has positive optical power, the fourth lens E4 has positive optical power, the fifth lens E5 has positive optical power, the sixth lens E6 has positive optical power, the seventh lens has negative optical power, and the eighth lens has negative optical power. The optical parameters of the optical imaging lens in Embodiment 3 under Embodiments 3-1, 3-2, and 3-3 are shown in Table 7 below (unit: mm), the structural parameters are shown in Table 8 below (unit: mm), and the values ​​of each conditional expression are shown in Table 9 below.

[0136] Figure 22 The on-axis chromatic aberration curve of the optical imaging lens of Embodiment 3 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the optical imaging lens. Figure 23 The astigmatism curve of the optical imaging lens of Embodiment 3 is shown, which represents the curvature of the meridional and sagittal image planes. Figure 24 The distortion curve of the optical imaging lens in Embodiment 3 is shown, representing the distortion magnitude corresponding to different half-field angles. According to... Figures 22 to 24 As can be seen, the curves are balanced, and chromatic aberration, astigmatism and distortion are well controlled. In other words, the optical imaging lens given in Example 3 can achieve good imaging quality.

[0137] Table 7

[0138]

[0139] Table 8

[0140]

[0141] Table 9

[0142]

[0143] It should be understood that the structure or architecture described above is merely exemplary, and the implementation methods and entities of this application are not limited thereto, but can be modified without departing from the spirit of this application. It is understood that the description of the various embodiments in this disclosure emphasizes the differences between the various embodiments, and their similarities or corresponding parts can be referred to mutually. For the purpose of brevity, this disclosure will not elaborate on each one.

[0144] While numerous embodiments of this application have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will arise for those skilled in the art without departing from the spirit and intent of this application. It should be understood that various alternatives to the embodiments of this application described herein may be employed in the practice of this application. The appended claims are intended to define the scope of protection of this application and therefore cover equivalents or alternatives within the scope of these claims.

Claims

1. An optical imaging lens, characterized in that, It includes a lens barrel and a lens group and a plurality of spacer elements disposed in the lens barrel, and at least one spacer element is provided between any two adjacent lenses in the lens group; The lens group comprises, in sequence along the optical axis from the object side to the image side: a first lens with negative optical power, the image side of which is concave; a second lens with positive optical power; a third lens with either positive or negative optical power, the object side of which is convex and the image side of which is concave; a fourth lens with positive optical power, both the object side and the image side of which are convex; a fifth lens with positive optical power, the image side of which is convex; a sixth lens with positive optical power, the image side of which is convex; a seventh lens with negative optical power, the image side of which is concave; and an eighth lens with negative optical power, the object side of which is convex and the image side of which is concave. The plurality of spacers includes a first spacer and a second spacer; the first spacer is disposed between the first lens and the second lens, and the object side of the first spacer is in contact with the image side of the first lens; the second spacer is disposed between the second lens and the third lens, and the object side of the second spacer is in contact with the image side of the second lens. The center thickness CT1 of the first lens, the center thickness CT2 of the second lens, and the air gap T12 between the first lens and the second lens on the optical axis satisfy the following: 1.00 < (CT1 + CT2) / T12 ≤ 1.70; The distance EP01 from the object side of the lens barrel to the object side of the first spacer element along the optical axis satisfies the following condition with respect to the center thickness CT1 of the first lens: 4.10≤EP01 / CT1≤4.

87. The outer diameter of the object side of the first spacer element, D1s, the outer diameter of the object side of the second spacer element, and the distance EP12 from the image side of the first spacer element to the object side of the second spacer element along the optical axis satisfy the following condition: 0.11≤|D1s-D2s| / EP12<0.

90.

2. The optical imaging lens according to claim 1, characterized in that, The outer diameter D2s of the object side of the second spacer, the inner diameter d2s of the object side of the second spacer, and the maximum thickness CP2 of the second spacer along the optical axis satisfy the following condition: 2.35 < (D2s - d2s) / CP2 ≤ 10.

72.

3. The optical imaging lens according to claim 1, characterized in that, The air gap T23 between the second lens and the third lens on the optical axis, and the maximum thickness CP2 of the second spacer element along the optical axis direction, satisfy the following condition: 0.57 ≤ T23 / CP2 < 1.

85.

4. The optical imaging lens according to claim 1, characterized in that, The plurality of spacers includes a second auxiliary spacer; the second auxiliary spacer is disposed between the second spacer and the third lens, and the object side of the second auxiliary spacer is in contact with the image side of the second spacer. The outer diameter D2bs of the object side of the second auxiliary spacer element, the inner diameter d2bs of the object side of the second auxiliary spacer element, the outer diameter D2m of the image side of the second spacer element, and the inner diameter d2m of the image side of the second spacer element satisfy the following condition: 3.30 < (D2bs - d2bs) / (D2m - d2m) < 5.

15.

5. The optical imaging lens according to claim 1, characterized in that, The plurality of spacers further includes a third spacer and a fourth spacer; the third spacer is disposed between the third lens and the fourth lens, and the object side of the third spacer is in contact with the image side of the third lens; the fourth spacer is disposed between the fourth lens and the fifth lens, and the object side of the fourth spacer is in contact with the image side of the fourth lens. The outer diameter of the object side of the fourth spacer element, D4s, the outer diameter of the image side of the third spacer element, D3m, and the combined focal length f34 of the third lens and the fourth lens satisfy the following condition: 2.45 < (D4s + D3m) / f34 ≤ 3.

51.

6. The optical imaging lens according to claim 1, characterized in that, The plurality of spacers further includes a fourth spacer and a fifth spacer; the fourth spacer is disposed between the fourth lens and the fifth lens, and the object side of the fourth spacer is in contact with the image side of the fourth lens; the fifth spacer is disposed between the fifth lens and the sixth lens, and the object side of the fifth spacer is in contact with the image side of the fifth lens. The outer diameter of the image side of the fourth spacer element, D4m, the outer diameter of the object side of the fifth lens, D5s, and the distance EP45 from the image side of the fourth spacer element to the object side of the fifth spacer element along the optical axis satisfy the following condition: 2.00≤EP45 / (D4m-D5s)<9.

30.

7. The optical imaging lens according to claim 1, characterized in that, The plurality of spacers also includes a fifth spacer, which is disposed between the fifth lens and the sixth lens, and the object side of the fifth spacer is in contact with the image side of the fifth lens. The effective focal length f5 of the fifth lens and the inner diameter d5s of the object side of the fifth spacer element satisfy the following condition: 1.59 ≤ f5 / d5s < 3.

60.

8. The optical imaging lens according to claim 1, characterized in that, The plurality of spacers further includes a sixth spacer and a seventh spacer; the sixth spacer is disposed between the sixth lens and the seventh lens, and the object side of the sixth spacer is in contact with the image side of the sixth lens; the seventh spacer is disposed between the seventh lens and the eighth lens, and the object side of the seventh spacer is in contact with the image side of the seventh lens. The distance EP67 between the image side of the sixth spacer element and the object side of the seventh spacer element along the optical axis, the maximum thickness CP7 of the seventh spacer element along the optical axis, the air gap T67 between the sixth lens and the seventh lens on the optical axis, and the center thickness CT7 of the seventh lens satisfy the following condition: 2.10 < (EP67 + CP7) / (T67 + CT7) < 3.

75.

9. The optical imaging lens according to claim 1, characterized in that, The plurality of spacers also includes a seventh spacer; the seventh spacer is disposed between the seventh lens and the eighth lens, and the object side of the seventh spacer is in contact with the image side of the seventh lens. The radius of curvature R15 of the object side of the eighth lens, the radius of curvature R16 of the image side of the eighth lens, and the center thickness CT8 of the eighth lens satisfy the following condition: 22.89≤(R15+R16) / CT8≤27.

88. The inner diameter d7s of the object side surface of the seventh spacer element and the radius of curvature R15 of the object side surface of the eighth lens satisfy the following condition: 0.50≤d7s / R15≤1.

58.

10. The optical imaging lens according to claim 1, characterized in that, The maximum height L of the lens barrel and the distance Tr7r12 on the optical axis from the object side of the fourth lens to the image side of the sixth lens satisfy the following condition: 3.90 < L / Tr7r12 < 4.

75.

11. The optical imaging lens according to claim 1, characterized in that, The plurality of spacers also includes a seventh spacer and a seventh auxiliary spacer; the seventh spacer is disposed between the seventh lens and the eighth lens, and the object side of the seventh spacer is in contact with the image side of the seventh lens; the seventh auxiliary spacer is disposed between the seventh spacer and the eighth lens, and the object side of the seventh auxiliary spacer is in contact with the image side of the seventh spacer. The radius of curvature R14 of the image side of the seventh lens and the inner diameter d7bs of the object side of the seventh auxiliary spacer element satisfy the following condition: 0.53≤R14 / d7bs<1.

60.

12. The optical imaging lens according to claim 1, characterized in that, The plurality of spacers also includes a seventh spacer; the seventh spacer is disposed between the seventh lens and the eighth lens, and the object side of the seventh spacer is in contact with the image side of the seventh lens. The effective focal length f7 of the seventh lens and the maximum thickness CP7 of the seventh spacer element along the optical axis satisfy the following condition: -15.40 < f7 / CP7 ≤ -7.

24.

13. The optical imaging lens according to claim 1, characterized in that, The plurality of spacers also includes an eighth spacer; the eighth spacer is disposed on the image side of the eighth lens, and the object side of the eighth spacer is in contact with the image side of the eighth lens. The inner diameter d8m of the image side of the eighth spacer element, the inner diameter d1s of the object side of the first spacer element, and the effective focal length f of the optical imaging lens satisfy the following condition: 1.55 < (d8m - d1s) / f ≤ 2.

16.

14. The optical imaging lens according to claim 1, characterized in that, The axial distance TD between the object side surface of the first lens and the image side surface of the eighth lens, the outer diameter D0m of the image side surface of the lens barrel, and the outer diameter D0s of the object side surface of the lens barrel satisfy the following condition: 2.13≤TD / (D0m-D0s)≤8.75.

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