Optical lens

Abstract

The utility model provides an optical lens. The optical lens comprises a lens barrel, and a first lens, a second lens, a third lens and a fourth lens which are sequentially arranged in the lens barrel from an object side to an image side; the spacing element group at least comprises a second spacing element and a third spacing element, and the inner diameter d0m of the image side end face of the lens barrel and the curvature radius R8 of the image side face of the fourth lens meet the condition that d0m / R8 is larger than or equal to 2.6 and smaller than or equal to 8.67; the combined focal length f34 of the third lens and the fourth lens, the center thickness CT4 of the fourth lens on the optical axis, and the minimum distance EP23 between the second spacing element and the third spacing element in the extension direction of the optical axis meet the condition that f34 (EP2 + CT4) is larger than or equal to 1.04 and smaller than or equal to 2.36. According to the utility model, the problem that the maximum angle of the optical lens when the light is converged to the chip is not matched with the chip in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to optical imaging equipment technical field, specifically, relate to an optical lens. BACKGROUND

[0002] With the development of science and technology, more and more electronic products have the function of taking pictures, and with the improvement of the demand of users for the electronic products, the requirement of optical lens carried on the electronic products is also gradually improved.For example, the optical lens is required to have a larger field of view. Part of the optical lens increases the light outlet diameter of the lens barrel and designs the last lens, so that the optical lens has a larger field of view, but it may cause the problem that the maximum angle (Chief Ray Angle, CRA) of light convergence to the chip is not matched with the chip, and then the imaging quality is poor.

[0003] That is, the optical lens in the prior art has the problem that the maximum angle of light convergence to the chip is not matched with the chip. UTILITY MODEL CONTENT

[0004] The main purpose of the utility model is to provide an optical lens to solve the problem that the maximum angle of light convergence to the chip is not matched with the chip in the prior art.

[0005] In order to achieve the above purpose, according to one aspect of the utility model, an optical lens is provided, the optical lens is suitable for near-infrared waveband imaging, and the optical lens comprises a lens barrel, a lens group and a spacer element group arranged in the lens barrel, the lens group is composed of four lenses, and the lens group is sequentially arranged from an object side to an image side along the extension direction of the optical axis as a first lens, a second lens, a third lens and a fourth lens; the spacer element group comprises at least a second spacer element and a third spacer element, the second spacer element is located between the second lens and the third lens and contacts a part of the image side surface of the second lens, and the third spacer element is located between the third lens and the fourth lens and contacts a part of the image side surface of the third lens; the inner diameter d0m of the image side end surface of the lens barrel and the curvature radius R8 of the image side surface of the fourth lens satisfy: 2.6≤d0m / |R8|≤8.67; the combined focal length f34 of the third lens and the fourth lens, the center thickness CT4 of the fourth lens on the optical axis and the minimum distance EP23 of the second spacer element and the third spacer element in the extension direction of the optical axis satisfy: 1.04≤f34(EP23+CT4)≤2.36.

[0006] According to another aspect of the utility model, provide a kind of optical lens, optical lens is suitable for near-infrared waveband imaging, optical lens includes: lens barrel and the lens group and spacer element group being arranged in lens barrel, lens group is made of four lenses, lens group is sequentially first lens, second lens, third lens and fourth lens from object side to image side along the extension direction of optical axis;Spacer element group at least includes first spacer element, and first spacer element is located between first lens and second lens and contact with the part of image side surface of first lens;The curvature radius R1 of object side surface of first lens, the outer diameter D0s of object side end surface of lens barrel satisfy between-2.49≤R1 / D0s≤-0.21;The curvature radius R3 of object side surface of second lens, the outer diameter D1m of image side surface of first spacer element, the inner diameter d1m of image side surface of first spacer element satisfy between 0.44≤R3 / (D1m-d1m)≤1.48.

[0007] According to another aspect of the utility model, provide a kind of optical lens, optical lens is suitable for near-infrared waveband imaging, optical lens includes: lens barrel and the lens group and spacer element group being arranged in lens barrel, lens group is made of four lenses, lens group is sequentially first lens, second lens, third lens and fourth lens from object side to image side along the extension direction of optical axis;Spacer element group at least includes first spacer element and second spacer element, first spacer element is located between first lens and second lens and contact with the part of image side surface of first lens, second spacer element is located between second lens and third lens and contact with the part of image side surface of second lens, third spacer element is located between third lens and fourth lens and contact with the part of image side surface of third lens;The combined focal length f23 of second lens and third lens, the central thickness CT2 of second lens on optical axis, the minimum distance EP23 of first spacer element and second spacer element in the extension direction of optical axis satisfy between 0.9≤f23 / (CT2+EP12)≤3.64;The curvature radius R4 of image side surface of second lens, the curvature radius R5 of object side surface of third lens, the inner diameter d2s of object side surface of second spacer element, the inner diameter d2m of image side surface of second spacer element satisfy between 2.86≤|R4| / d2s+|R5| / d2m≤4.08.

[0008] Further, the curvature radius R4 of image side surface of second lens, the refractive index N2 of second lens, the outer diameter D2s of object side surface of second spacer element satisfy between 0.84≤|R4*N2 / D2s|≤2.83.

[0009] Further, the curvature radius R5 of object side surface of third lens, the inner diameter d2m of image side surface of second spacer element satisfy between 0.18≤|R5| / d2m≤0.89.

[0010] Further, the radius of curvature R6 of the image side surface of the third lens, the outer diameter D3s of the object side surface of the third spacer element, and the inner diameter d3s of the object side surface of the third spacer element satisfy 0.28 ≤ |R6| / (D3s-d3s) ≤ 0.81.

[0011] Further, the central thickness CT3 of the third lens in the optical axis direction, the air interval T23 of the second lens and the third lens in the optical axis direction, and the minimum distance EP23 of the second spacer element and the third spacer element in the extension direction of the optical axis satisfy 0.56 ≤ (CT3+T23) / EP23 ≤ 2.06.

[0012] Further, the radius of curvature R1 of the object side surface of the first lens and the outer diameter D0s of the object side end surface of the lens barrel satisfy -2.49 ≤ R1 / D0s ≤ -0.21.

[0013] Further, the outer diameter D0m of the image side end surface of the lens barrel and the outer diameter D0s of the object side end surface of the lens barrel satisfy 0.22 mm ≤ D0m-D0s ≤ 0.99 mm.

[0014] Further, the spacer element group further includes a first spacer element which is located between the first lens and the second lens and which is in contact with a part of the image side surface of the first lens, and the minimum distance EP01 of the object side end surface of the lens barrel and the first spacer element in the extension direction of the optical axis and the central thickness CT1 of the first lens in the optical axis direction satisfy 1.9 ≤ EP01 / CT1 ≤ 2.68.

[0015] Further, the spacer element group further includes a first spacer element which is located between the first lens and the second lens and which is in contact with a part of the image side surface of the first lens, and the radius of curvature R1 of the object side surface of the first lens, the outer diameter D1s of the object side surface of the first spacer element, and the inner diameter d1s of the object side surface of the first spacer element satisfy -3.94 ≤ R1 / (D1s-d1s) ≤ -0.33.

[0016] Further, the spacer element group further includes a first spacer element which is located between the first lens and the second lens and which is in contact with a part of the image side surface of the first lens, and the inner diameter d1s of the object side surface of the first spacer element and the radius of curvature R2 of the image side surface of the first lens satisfy 1.27 ≤ |R2 / d1s| ≤ 6.63.

[0017] Furthermore, the spacer element group also includes a first spacer element, which is located between the first lens and the second lens and contacts a portion of the image side of the first lens. The air gap T12 between the first lens and the second lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, and the minimum distance EP12 between the first spacer element and the second spacer element in the extension direction of the optical axis satisfy the following: 1.12≤(T12+CT2) / EP12≤2.21.

[0018] Furthermore, the spacer element group also includes a first spacer element, which is located between the first lens and the second lens and contacts a portion of the image side surface of the first lens. The radius of curvature R3 of the object side surface of the second lens, the outer diameter D1m of the image side surface of the first spacer element, and the inner diameter d1m of the image side surface of the first spacer element satisfy the following: 0.44≤R3 / (D1m-d1m)≤1.48.

[0019] Furthermore, the optical lens satisfies at least one of the following:

[0020] The first lens has negative optical power;

[0021] The second lens has positive optical power.

[0022] Furthermore, the optical lens satisfies at least one of the following:

[0023] The object side of the first lens is concave;

[0024] The object-side surface of the second lens is convex.

[0025] Applying the technical solution of this utility model, the optical lens is suitable for near-infrared imaging. The optical lens includes: a lens barrel and a lens group and a spacer element group disposed within the lens barrel. The lens group consists of four lenses, which are arranged sequentially from the object side to the image side along the extension direction of the optical axis as a first lens, a second lens, a third lens, and a fourth lens. The spacer element group includes at least a second spacer element and a third spacer element. The second spacer element is located between the second and third lenses and contacts a portion of the image side surface of the second lens. The third spacer element is located between the third and fourth lenses and contacts a portion of the image side surface of the third lens. The inner diameter d0m of the image side end face of the lens barrel and the radius of curvature R8 of the image side surface of the fourth lens satisfy the following: 2.6≤d0m / |R8|≤8.67. The combined focal length f34 of the third and fourth lenses, the center thickness CT4 of the fourth lens on the optical axis, and the minimum distance EP23 between the second and third spacer elements in the extension direction of the optical axis satisfy the following: 1.04≤f34(EP23+CT4)≤2.36.

[0026] The optical lens of this application consists of a lens barrel, four lenses, and at least two spacer elements. By reasonably controlling the relationship between the inner diameter d0m of the image-side end face of the lens barrel and the radius of curvature R8 of the image-side surface of the fourth lens, the optical lens, when satisfying 2.6≤d0m / |R8|≤8.67, can not only guarantee the effective width of the flange position of the fourth lens, but also control the exit angle of light when passing through the image-side surface of the fourth lens, which is beneficial for large-angle light emission and improves the field of view of the optical lens. However, at the same time, it will cause a mismatch between the maximum angle at which light converges to the chip and the chip itself, thus leading to image quality problems. This application also reduces the influence of manufacturing tolerances and assembly precision of the third and fourth lenses on the optical transmission path by constraining the relationship between the combined focal length f34 of the third and fourth lenses, the center thickness CT4 of the fourth lens on the optical axis, and the minimum distance EP23 between the second and third spacers in the extension direction of the optical axis. This ensures that the light is transmitted along a preset path within the third and fourth lenses, avoiding the problem of the maximum angle of light converging on the chip not matching the chip due to changes in the distance between the lenses or the center thickness and edge thickness. Attached Figure Description

[0027] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0028] Figure 1 A dimensioned diagram of an optical lens according to an alternative embodiment of the present invention is shown;

[0029] Figure 2 A schematic diagram of the structure of the optical lens of Embodiment 1-1 of this utility model is shown;

[0030] Figure 3 A schematic diagram of the optical lens structure of Embodiments 1-2 of this utility model is shown;

[0031] Figure 4 The diagram shows the structural schematics of the optical lenses of embodiments 1-3 of this utility model;

[0032] Figures 5 to 8 The on-axis chromatic aberration, astigmatism curve, distortion curve, and magnification chromatic aberration curve of the optical lens of Embodiment 1 of this utility model are shown respectively.

[0033] Figure 9 A schematic diagram of the optical lens of Embodiment 2-1 of this utility model is shown;

[0034] Figure 10A schematic diagram of the optical lens of Embodiment 2-2 of this utility model is shown;

[0035] Figure 11 A schematic diagram of the optical lens structure of embodiments 2-3 of this utility model is shown;

[0036] Figures 12 to 15 The on-axis chromatic aberration, astigmatism curve, distortion curve, and magnification chromatic aberration curve of the optical lens of Embodiment 2 of this utility model are shown respectively.

[0037] Figure 16 A schematic diagram of the structure of the optical lens of Embodiment 3-1 of this utility model is shown;

[0038] Figure 17 A schematic diagram of the optical lens structure of Embodiment 3-2 of this utility model is shown;

[0039] Figure 18 A schematic diagram of the optical lens of Embodiment 3-3 of this utility model is shown;

[0040] Figures 19 to 22 The on-axis chromatic aberration, astigmatism curve, distortion curve, and magnification chromatic aberration curve of the optical lens of Embodiment 3 of this utility model are shown respectively.

[0041] Figure 23 This diagram illustrates the relationship between the maximum angle at which the optical lens converges onto the chip and the image height, according to an optional embodiment of the present invention.

[0042] Figure 24 A schematic diagram illustrating the relationship between the maximum angle at which an optical lens converges onto a chip and the image height is shown;

[0043] Figure 25 Another example is shown in the diagram illustrating the relationship between the maximum angle at which the optical lens converges onto the chip and the image height.

[0044] The above figures include the following reference numerals:

[0045] E1, First lens; P1, First spacer element; P1b, First auxiliary spacer element; E2, Second lens; P2, Second spacer element; P2b, Second auxiliary spacer element; E3, Third lens; P3, Third spacer element; P3b, Third auxiliary spacer element; E4, Fourth lens; S1, Object-side surface of the first lens; S2, Image-side surface of the first lens; S3, Object-side surface of the second lens; S4, Image-side surface of the second lens; S5, Object-side surface of the third lens; S6, Image-side surface of the third lens; S7, Object-side surface of the fourth lens; S8, Image-side surface of the fourth lens. Detailed Implementation

[0046] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0047] 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.

[0048] In this utility model, 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 used to limit this utility model.

[0049] 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.

[0050] 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.

[0051] 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 the judgment method commonly known in the art, using the R value (R refers to the radius of curvature of the paraxial region, usually the R value in the lens database of optical software) to determine concavity or convexity. For the object side, 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, 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. In this application, the left side is the object side, and the right side is the image side.

[0052] To address the problem in existing optical lenses where the maximum angle at which light converges onto the chip is not compatible with the chip's properties, this invention provides an optical lens.

[0053] like Figures 1 to 22As shown, the optical lens is suitable for near-infrared imaging. The optical lens includes: a lens barrel and a lens group and a spacer group disposed within the lens barrel. The lens group consists of four lenses, which are arranged sequentially from the object side to the image side along the optical axis as a first lens, a second lens, a third lens, and a fourth lens. The spacer group includes at least a second spacer and a third spacer. The second spacer is located between the second and third lenses and contacts a portion of the image side surface of the second lens. The third spacer is located between the third and fourth lenses and contacts a portion of the image side surface of the third lens. The inner diameter d0m of the image side end face of the lens barrel and the radius of curvature R8 of the image side surface of the fourth lens satisfy the following condition: 2.6≤d0m / |R8|≤8.67. The combined focal length f34 of the third and fourth lenses, the center thickness CT4 of the fourth lens on the optical axis, and the minimum distance EP23 between the second and third spacers in the optical axis extension direction satisfy the following condition: 1.04≤f34(EP23+CT4)≤2.36.

[0054] The optical lens of this application consists of a lens barrel, four lenses, and at least two spacer elements. By reasonably controlling the relationship between the inner diameter d0m of the image-side end face of the lens barrel and the radius of curvature R8 of the image-side surface of the fourth lens, the optical lens, when satisfying 2.6≤d0m / |R8|≤8.67, can not only guarantee the effective width of the flange position of the fourth lens, but also control the exit angle of light when passing through the image-side surface of the fourth lens, which is beneficial for large-angle light emission and improves the field of view of the optical lens. However, at the same time, it will cause a mismatch between the maximum angle at which light converges to the chip and the chip itself, thus leading to image quality problems. This application also reduces the influence of manufacturing tolerances and assembly precision of the third and fourth lenses on the optical transmission path by constraining the relationship between the combined focal length f34 of the third and fourth lenses, the center thickness CT4 of the fourth lens on the optical axis, and the minimum distance EP23 between the second and third spacers in the extension direction of the optical axis. This ensures that the light is transmitted along a preset path within the third and fourth lenses, avoiding the problem of the maximum angle of light converging on the chip not matching the chip due to changes in the distance between the lenses or the center thickness and edge thickness.

[0055] In addition, please refer to Table 1 below and Figures 23 to 25 As shown, Figure 23 The diagram illustrates the relationship between the maximum convergence angle of the optical lens onto the chip and the image height when d0m / |R8|=3.74 and f34(EP23+CT4)=1.24. Figure 24 The diagram illustrates the relationship between the maximum convergence angle of the optical lens onto the chip and the image height when d0m / |R8|=3.74 and f34(EP23+CT4)=0.9. Figure 25A schematic diagram showing the relationship between the maximum angle of convergence of the optical lens to the chip and the image height when d0m / |R8|=3.74 and f34(EP23+CT4)=2.5 is shown.

[0056] Depend on Figures 23 to 25 It can be seen that when f34(EP23+CT4) = 1.24, the maximum convergence angle to the chip and the image height are linearly related, indicating a good match between the maximum convergence angle and the chip. When f34(EP23+CT4) = 0.9, the maximum convergence angle and the image height are no longer linearly related, indicating a mismatch between the maximum convergence angle and the chip, resulting in poor performance. When f34(EP23+CT4) = 2.5, the maximum convergence angle and the image height are no longer linearly related, indicating a mismatch between the maximum convergence angle and the chip, resulting in poor performance. Therefore, when f34(EP23+CT4) is in the range of 1.04 to 2.36, the maximum convergence angle of the optical lens to the chip is well-matched with the chip. Therefore, by constraining 1.04≤f34(EP23+CT4)≤2.36, this application can ensure that the light is transmitted along a preset path within the third and fourth lenses, effectively reducing the influence of manufacturing tolerances and assembly precision of the third and fourth lenses on the optical transmission path, and avoiding the problem that the maximum angle of light converging on the chip is not compatible with the chip due to changes in the spacing or thickness of the lens combination.

[0057]

[0058] Table 1

[0059] It should be noted that this application limits f34(EP23+CT4) within a reasonable range to control light deflection, optimize the size of lenses and spacers, ensure the processing accuracy of parts, and improve the smoothness of the light path. This addresses the mismatch between the maximum convergence angle to the chip and the chip caused by d0m / |R8| being in the range of 2.6 to 8.67. When f34(EP23+CT4) meets the above-mentioned range, the goal of improving the matching degree between the maximum convergence angle to the chip and the chip can be achieved, without relying on the optical power and surface shape of the lens. The optical power and surface shape of the lens are further optimizations of the optical lens based on these factors. Each lens can be positive or negative according to the actual design requirements of the optical system, and the surface shape of each lens can also be convex or concave according to the design requirements of the optical system. When the optical system satisfies: 2.6≤d0m / |R8|≤8.67; 1.04≤f34(EP23+CT4)≤2.36, the maximum convergence angle of the optical lens to the chip can be matched with the chip.

[0060] For example, the first lens has negative optical power, and the second lens has positive optical power. Another example is that the object-side surface of the first lens is concave, and the object-side surface of the second lens is convex. Optical lenses can be simulated using software and / or tools such as ZEMAX and CODEV. Preferably, optical lenses can be simulated using CODEV. During simulation using software and / or tools as described above, the surface profiles of each lens can be simulated and appropriately adjusted according to the built-in surface profiles of the software and / or tools used.

[0061] In some optional embodiments, the radius of curvature R4 of the image-side surface of the second lens, the refractive index N2 of the second lens, and the outer diameter D2s of the object-side surface of the second spacer element satisfy the following relationship: 0.84 ≤ |R4*N2 / D2s| ≤ 2.83. If the angle of the emitted light from the second lens is unreasonable, or if the second lens and its refractive index are mismatched, strong stray light may be generated, forming a ghost image. By constraining the relationship between the radius of curvature of the image-side surface of the second lens, the refractive index of the second lens, and the outer diameter of the object-side surface of the second spacer element, it can be ensured that the light is transmitted at an appropriate angle after passing through the second lens, thereby optimizing the light path of the entire lens, reducing multiple reflections and refractions in the light path, and improving the light transmission efficiency. At the same time, matching with the refractive index of the second lens can control the energy of the ghost image spot, ensuring that its impact on imaging is minimized. Furthermore, by constraining |R4*N2 / D2s| within a reasonable range, the exit angle of light from the second lens is controlled. At the same time, the second spacer element can absorb some of the light rays that are deflected at large angles, reducing the light rays that hit the inner wall of the lens barrel, thereby reducing the generation of stray light and improving the imaging quality of the optical lens.

[0062] In some optional embodiments, the radius of curvature R5 of the object-side surface of the third lens and the inner diameter d2m of the image-side surface of the second spacer element satisfy the following condition: 0.18 ≤ |R5| / d2m ≤ 0.89. By constraining the relationship between the radius of curvature of the object-side surface of the third lens and the inner diameter of the image-side surface of the second spacer element, the deflection angle of light entering the third lens can be effectively controlled. At the same time, the second spacer element can block the edge of the effective diameter of the object-side surface of the third lens, avoiding reflection of light between the second and third lenses, which is beneficial to improving the imaging quality of the optical lens.

[0063] In some optional embodiments, the radius of curvature R6 of the image-side surface of the third lens, the outer diameter D3s of the object-side surface of the third spacer element, and the inner diameter d3s of the object-side surface of the third spacer element satisfy the following condition: 0.28 ≤ |R6| / (D3s-d3s) ≤ 0.81. By constraining |R6| / (D3s-d3s) within a reasonable range, the deflection angle of light passing through the image-side surface of the third lens can be controlled, which helps to reduce the energy of ghosting spots, improve image contrast and sharpness, and ensure that imaging light passes smoothly through the third spacer element. Furthermore, the third spacer element can absorb stray light reflected from the edge region of the image-side surface of the third lens, which is beneficial to improving the imaging quality of the optical lens.

[0064] In some optional embodiments, the center thickness CT3 of the third lens on the optical axis, the air gap T23 between the second and third lenses on the optical axis, and the minimum distance EP23 between the second and third spacer elements in the extending direction of the optical axis satisfy the following condition: 0.56 ≤ (CT3 + T23) / EP23 ≤ 2.06. By constraining (CT3 + T23) / EP23 within a reasonable range, it is beneficial to ensure the uniformity of the center and edge thickness distribution of the third lens, improve the overall thickness uniformity of the third lens, and ensure that the change in the air gap between the second and third lenses before and after baking is within a reasonable range, thus preventing significant differences in the optical performance of the optical lens.

[0065] In some optional embodiments, the radius of curvature R1 of the object-side surface of the first lens and the outer diameter D0s of the object-side end face of the lens barrel satisfy the following condition: -2.49 ≤ R1 / D0s ≤ -0.21. By constraining R1 / D0s within a reasonable range, it is beneficial to ensure the incident angle of light on the object-side surface of the first lens, to ensure the object-side field of view of the optical lens, to facilitate the incident of large-angle light into the optical lens, and to improve the imaging capability of the optical lens in dark environments. At the same time, ensuring the outer diameter of the object-side end face of the lens barrel is beneficial to the miniaturization of the optical lens, and also ensures the minimum width of the object-side end face of the lens barrel for assembly support, thus ensuring assembly stability.

[0066] In some optional embodiments, the outer diameter D0m of the image-side end face of the lens barrel and the outer diameter D0s of the object-side end face of the lens barrel satisfy the following condition: 0.22mm ≤ D0m - D0s ≤ 0.99mm. By constraining D0m-D0s within a reasonable range, a smaller difference is achieved between the outer diameters of the image-side and object-side end faces of the lens barrel, resulting in smaller step differences in the internal lenses. This helps improve assembly stability. Furthermore, with smaller outer diameters of both the image-side and object-side end faces of the lens barrel, a smaller head size can be achieved, making the optical lens suitable for a wider range of end devices.

[0067] In some optional embodiments, the spacer element group further includes a first spacer element located between the first lens and the second lens and in contact with a portion of the image-side surface of the first lens. The minimum distance EP01 between the object-side end face of the lens barrel and the first spacer element in the optical axis extension direction, and the center thickness CT1 of the first lens in the optical axis, satisfy the following: 1.9 ≤ EP01 / CT1 ≤ 2.68. By constraining EP01 / CT1 within a reasonable range, the structural strength of the lens barrel is ensured while preventing excessive differences between the center thickness and edge thickness of the first lens, thus ensuring the uniformity of the thickness of the first lens. This helps reduce the molding difficulty of the first lens and improves the assembly stability of the first lens, as well as the stability of the lens barrel structure.

[0068] In some optional embodiments, the spacer element group further includes a first spacer element located between the first lens and the second lens and in contact with a portion of the image-side surface of the first lens. The radius of curvature R1 of the object-side surface of the first lens, the outer diameter D1s of the object-side surface of the first spacer element, and the inner diameter d1s of the object-side surface of the first spacer element satisfy the following: -3.94 ≤ R1 / (D1s-d1s) ≤ -0.33. Constraining R1 / (D1s-d1s) within a reasonable range ensures the stability of the first lens while controlling the deflection angle of light entering the first lens, thereby guaranteeing the field of view of the optical lens. Furthermore, matching the outer and inner diameters of the object-side surface of the first spacer element helps reduce stray light generation.

[0069] In some optional embodiments, the spacer element group further includes a first spacer element located between the first lens and the second lens and in contact with a portion of the image-side surface of the first lens. The inner diameter d1s of the object-side surface of the first spacer element and the radius of curvature R2 of the image-side surface of the first lens satisfy the following condition: 1.27 ≤ |R2 / d1s| ≤ 6.63. Constraining |R2 / d1s| within a reasonable range can control the curvature of the effective diameter of the image-side surface of the first lens, and also control the position where the first spacer element blocks the effective diameter of the first lens. This effectively reduces light rays deflected towards the inner wall of the lens barrel, effectively reduces stray light generation, and improves the imaging quality of the optical lens.

[0070] In some optional embodiments, the spacer element group further includes a first spacer element located between the first lens and the second lens and in contact with a portion of the image-side surface of the first lens. The air gap T12 between the first and second lenses on the optical axis, the center thickness CT2 of the second lens on the optical axis, and the minimum distance EP12 between the first and second spacer elements in the extending direction of the optical axis satisfy the following condition: 1.12 ≤ (T12 + CT2) / EP12 ≤ 2.21. Constraining (T12 + CT2) / EP12 within a reasonable range can ensure the overall uniformity of the second lens, avoid excessive edge or center thickness of the second lens leading to second lens forming problems, reduce the risk of deformation of the second lens, and limit the air gap between the first and second lenses to prevent excessive air gap between the first and second lenses from causing the first and second lenses to be overly sensitive, effectively reducing the sensitivity of the first and second lenses.

[0071] In some optional embodiments, the spacer element group further includes a first spacer element located between the first lens and the second lens and in contact with a portion of the image-side surface of the first lens. The radius of curvature R3 of the object-side surface of the second lens, the outer diameter D1m of the image-side surface of the first spacer element, and the inner diameter d1m of the image-side surface of the first spacer element satisfy the following condition: 0.44 ≤ R3 / (D1m-d1m) ≤ 1.48. By constraining R3 / (D1m-d1m) within a reasonable range, the curvature of the object-side surface of the second lens can be constrained to control the degree of light deflection after passing through the object-side surface of the second lens. At the same time, limiting the outer and inner diameters of the image-side surface of the first spacer element can reduce stray light between the first and second lenses and improve the imaging quality of the optical lens.

[0072] In another embodiment of this utility model, an optical lens is provided. The optical lens is suitable for near-infrared imaging. The optical lens includes: a lens barrel and a lens group and a spacer element group disposed within the lens barrel. The lens group consists of four lenses, which are arranged sequentially from the object side to the image side along the extension direction of the optical axis as a first lens, a second lens, a third lens, and a fourth lens. The spacer element group includes at least a first spacer element, which is located between the first lens and the second lens and contacts a portion of the image side surface of the second lens. The radius of curvature R1 of the object side surface of the first lens and the outer diameter D0s of the object side end face of the lens barrel satisfy the following condition: -2.49≤R1 / D0s≤-0.21. The radius of curvature R3 of the object side surface of the second lens, the outer diameter D1m of the image side surface of the first spacer element, and the inner diameter d1m of the image side surface of the first spacer element satisfy the following condition: 0.44≤R3 / (D1m-d1m)≤1.48.

[0073] The optical lens of this application consists of a lens barrel, four lenses, and at least two spacer elements. By reasonably controlling the relationship between the radius of curvature R1 of the object side surface of the first lens and the outer diameter D0s of the object side end face of the lens barrel, the optical lens can not only have a small head when -2.49≤R1 / D0s≤-0.21, which is beneficial to the miniaturization of the optical lens, but also helps to ensure the incident angle of light on the object side surface of the first lens, thus ensuring the object side field of view of the optical lens. This also helps to allow large-angle light to enter the optical lens, which is beneficial to improving the imaging capability of the optical lens in dark environments. However, since the object side surface of the first lens has a diverging effect on light, some light is easily deflected towards the inner wall surface of the lens barrel, forming stray light. This application controls the deflection angle of light rays emitted from the first lens into the second lens by constraining R3 / (D1m-d1m) within a reasonable range, and controls the inner diameter of the image side of the first spacer element and the bearing width of the image side of the first spacer element. This effectively absorbs light rays deflected towards the inner wall of the lens barrel, reduces light rays deflected at large angles, and thus reduces the generation of stray light and lowers the energy of stray light.

[0074] In another embodiment of this utility model, an optical lens is provided, which is suitable for near-infrared imaging. The optical lens includes: a lens barrel and a lens group and a spacer element group disposed within the lens barrel. The lens group consists of four lenses, which are arranged sequentially from the object side to the image side along the extension direction of the optical axis as a first lens with negative optical power, a second lens with positive optical power, a third lens, and a fourth lens. The spacer element group includes at least a first spacer element and a second spacer element. The first spacer element is located between the first lens and the second lens and contacts a portion of the image-side surface of the first lens. The second spacer element is located between the second lens and the third lens and contacts a portion of the image-side surface of the second lens. The third spacer element is located between the third lens and the fourth lens and is in contact with a portion of the image-side surface of the third lens; the combined focal length f23 of the second lens and the third lens, the center thickness CT2 of the second lens on the optical axis, and the minimum distance EP23 between the first spacer element and the second spacer element in the extension direction of the optical axis satisfy: 0.9≤f23 / (CT2+EP12)≤3.64; the radius of curvature R4 of the image-side surface of the second lens, the radius of curvature R5 of the object-side surface of the third lens, the inner diameter d2s of the object-side surface of the second spacer element, and the inner diameter d2m of the image-side surface of the second spacer element satisfy: 2.86≤|R4| / d2s+|R5| / d2m≤4.08.

[0075] The optical lens of this application consists of a lens barrel, four lenses, and at least two spacer elements. By reasonably controlling the relationship between the combined focal length f23 of the second and third lenses, the center thickness CT2 of the second lens on the optical axis, and the minimum distance EP23 between the first and second spacer elements in the extension direction of the optical axis, the optical lens can satisfy 0.9≤f23 / (CT2+EP12)≤3.64. This allows control over the center thickness of the second lens and, by controlling the distance between the first and second spacer elements, limits the edge thickness of the second lens to a certain range, which helps ensure the structural strength of the second lens and improves assembly stability. However, this can easily lead to stray light reflection in the effective diameter structural area of ​​the second lens, affecting image quality. To reduce the occurrence of such reflected stray light, this application controls the deflection angle of light rays exiting from the image side of the second lens and the deflection angle of light rays entering the object side of the third lens by constraining the relationship between the radius of curvature R4 of the image side of the second lens, the radius of curvature R5 of the object side of the third lens, the inner diameter d2s of the object side of the second spacer element, and the inner diameter d2m of the image side of the second spacer element. This reduces the deflection of large-angle light rays. The restriction of the inner diameters of the object side and image side of the second spacer element can block the effective diameter edge positions of the second and third lenses, reducing the occurrence of reflected stray light and improving the imaging quality.

[0076] Of course, this embodiment may also include other parametric expressions as described in the above embodiments, which will not be elaborated here.

[0077] In some alternative embodiments, the above-mentioned multiple lenses may include at least one tangent lens. The outer peripheral surface of the tangent lens may have a tangent portion and a non-tangent portion, and the outer diameter of the tangent portion of the lens is smaller than the outer diameter of the non-tangent portion of the lens. When the outer peripheral surface of the lens has a tangent portion, the outer diameter of the lens usually refers to the outer diameter of the non-tangent portion of the lens.

[0078] In some alternative embodiments, at least one of the plurality of spacers described above may be a truncated spacer. The outer peripheral surface of the truncated spacer may have a truncated portion and a non-truncated portion, and the outer diameter of the truncated portion of the truncated spacer is smaller than the outer diameter of the non-truncated portion of the truncated spacer. The outer diameter of the spacer typically refers to the maximum outer diameter of the non-truncated portion.

[0079] Optionally, the aforementioned optical lens may also include protective glass for protecting the photosensitive element located on the imaging plane.

[0080] The optical lens in this application may employ multiple lenses, such as the four lenses described above. In this application, at least one of the mirror surfaces of each lens is an aspherical mirror surface. An aspherical lens is characterized by a continuously changing curvature from the lens center to the lens periphery. Unlike a spherical lens, which has a constant curvature from the lens center to the lens periphery, an aspherical lens has superior curvature radius characteristics, offering advantages in improving distortion aberrations and astigmatism. By using an aspherical lens, aberrations occurring during imaging can be eliminated as much as possible, thereby improving image quality.

[0081] However, those skilled in the art will understand that the number of lenses constituting the optical lens can be varied to obtain the various results and advantages described herein without departing from the technical solutions claimed in this application. For example, although four lenses have been described as an example in the embodiments, the optical lens is not limited to including four lenses. If necessary, the optical lens may also include other numbers of lenses.

[0082] Figure 1 A schematic diagram showing the dimensions of an optical lens according to this application is provided. Figure 1 The figures clearly indicate parameters such as d1s, d1m, D1s, D1m, d2m, D2s, d3s, D2m, d0s, d0m, D0s, D0m, CP1, CP2, EP12, and L to provide a clear and intuitive understanding of their meaning. To facilitate the description of the optical lens and the specific lens shape, these parameters will not be shown in the accompanying figures when describing specific embodiments.

[0083] The following description, with reference to the accompanying drawings, further illustrates examples of specific surface shapes and parameters of optical lenses applicable to the above embodiments.

[0084] 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 two examples within the same embodiment, the radii of curvature, center thickness, and other parameters of the first to fourth lenses, as well as the spacing distance and higher-order coefficients between the lenses, are the same. However, the thickness, inner diameter, and outer diameter of the lens barrel, the first spacer element, the second spacer element, and the third spacer element, and the shape of some lenses are different. In other words, the main structure used for imaging is the same, but the auxiliary structures used for imaging are different.

[0085] It should be noted that any one of the following embodiments, from Embodiment 1 to Embodiment 3, is applicable to all implementation methods of this application.

[0086] Example 1

[0087] like Figures 2 to 5 As shown, the optical lens of Embodiment 1 is described. Figure 2 A schematic diagram of the optical lens of Embodiment 1-1 is shown. Figure 3 A schematic diagram of the optical lens structure of Embodiments 1-2 is shown. Figure 4 A schematic diagram of the optical lens structure of Embodiments 1-3 is shown.

[0088] like Figures 2 to 4 As shown, the optical lens includes a lens barrel, four lenses and multiple spacer elements. The lens barrel includes a first lens E1, a first spacer element P1, a second lens E2, a second spacer element P2, a third lens E3, a third spacer element P3 and a fourth lens E4 arranged sequentially from the object side to the image side.

[0089] like Figure 2 The diagram shown is a schematic representation of the optical lens structure of Embodiment 1-1. In this example, the object-side surface S1 of the first lens abuts against the lens barrel portion. The object-side surface and image-side surface of the first spacer element P1 abut against the image-side surface S2 of the first lens and the object-side surface S3 of the second lens, respectively. The object-side surface and image-side surface of the second spacer element abut against the image-side surface S4 of the second lens and the object-side surface S5 of the third lens, respectively. The object-side surface and image-side surface of the third spacer element abut against the image-side surface S6 of the third lens and the object-side surface S7 of the fourth lens, respectively. The image-side surface S8 of the fourth lens is spaced apart from the lens barrel.

[0090] like Figure 3 The diagram shows a schematic of the optical lens structure of Embodiment 1-2. In this example, the optical lens also includes a second auxiliary spacer element P2b, which is located between the second spacer element P2 and the third lens E3. The object side and image side of the second auxiliary spacer element abut against the image side of the second spacer element and the object side S5 of the third lens, respectively. The abutment and contact methods of the other spacer elements are the same as in Embodiment 1-1, and can be referred to the relevant description in Embodiment 1-1, which will not be repeated here.

[0091] like Figure 4 The diagram shows the structure of the optical lens in Embodiments 1-3. In this example, the optical lens also includes a third auxiliary spacer element P3b, which is located between the third spacer element P3 and the fourth lens E4. The object side and image side of the third auxiliary spacer element abut against the image side of the third spacer element and the object side S7 of the fourth lens, respectively. The abutting and contacting methods of the other spacer elements are the same as in Embodiments 1-1. Please refer to the relevant description in Embodiments 1-1, which will not be repeated here.

[0092] In summary, the structural parameters of the optical lens of Embodiment 1 under Embodiments 1-1, 1-2, and 1-3 are shown in Table 9.

[0093] In Embodiment 1, the object-side surface S1 of the first lens is concave, and the image-side surface S2 of the first lens is concave. The object-side surface S3 of the second lens is convex, and the image-side surface S4 of the second lens is concave. The object-side surface S5 of the third lens is convex, and the image-side surface S6 of the third lens is convex. The object-side surface S7 of the fourth lens is convex, and the image-side surface S8 of the fourth lens is concave. In Table 2 below, S9 and S10 can be the surfaces of filters or protective glass, while S11 is the imaging surface, and STO is the aperture stop, not shown in the figure.

[0094] Table 2 shows the basic structural parameters of the optical lens in Embodiment 1, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0095]

[0096] Table 2

[0097] In Embodiment 1, the object-side surface and image-side surface of the first lens E1 to the fourth lens E4 are both aspherical surfaces. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0098]

[0099] 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. Table 3 below gives the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, and A28 that can be used for each aspherical mirror S1-S8 in Example 1.

[0100] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 A22 A24 A26 A28 S1 2.16E-01 -2.20E-02 4.23E-03 -1.23E-03 2.57E-04 -8.48E-05 1.77E-05 5.84E-07 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S2 5.65E-02 4.46E-03 9.14E-04 7.51E-05 -5.96E-05 -4.23E-05 -3.32E-05 -4.07E-06 -6.52E-07 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S3 -6.68E-04 -1.78E-05 7.82E-06 1.56E-05 -6.29E-06 1.02E-06 -6.15E-08 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S4 -7.87E-02 6.72E-03 -1.09E-03 2.96E-04 -4.66E-05 1.64E-06 1.10E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S5 -1.47E-01 4.55E-03 -3.06E-03 4.71E-04 -1.66E-04 2.42E-05 -6.03E-06 -3.57E-07 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S6 -1.38E-02 -2.02E-04 -2.58E-04 -3.28E-05 9.52E-05 -4.68E-05 1.10E-05 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S7 -1.97E-01 -3.48E-04 2.70E-03 -5.43E-04 7.86E-05 -3.26E-06 -7.55E-07 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S8 -2.02E-01 -1.79E-05 1.74E-03 -1.19E-03 3.62E-04 -6.70E-05 4.40E-06 -5.08E-08 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00

[0101] Table 3

[0102] Figure 5 The on-axis chromatic aberration curve of the optical lens of Embodiment 1 is shown, which indicates the deflection of the focal point of light of different wavelengths after passing through the optical lens. Figure 6 The astigmatism curve of the optical lens of Embodiment 1 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 7 The distortion curve of the optical lens of Embodiment 1 is shown, which represents the distortion magnitude value corresponding to different field of view angles. Figure 8The magnification chromatic aberration curve of the optical lens of Embodiment 1 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the lens.

[0103] according to Figures 5 to 8 As can be seen, the optical lens given in Example 1 can achieve good imaging quality.

[0104] Example 2

[0105] like Figures 9 to 15 As shown, the optical lens of Embodiment 2 is described. Figure 9 A schematic diagram of the optical lens of Embodiment 2-1 is shown. Figure 10 A schematic diagram of the optical lens of Embodiment 2-2 is shown. Figure 11 A schematic diagram of the optical lens of Embodiments 2-3 is shown.

[0106] like Figures 9 to 11 As shown, the optical lens includes a lens barrel, four lenses and multiple spacer elements. The lens barrel includes a first lens E1, a first spacer element P1, a second lens E2, a second spacer element P2, a third lens E3, a third spacer element P3 and a fourth lens E4 arranged sequentially from the object side to the image side.

[0107] like Figure 9 The diagram shows a schematic of the optical lens structure of Embodiment 2-1. In this example, the optical lens further includes a first auxiliary spacer element P1b, which is located between the first spacer element P1 and the second lens E2. The object-side surface S1 of the first lens abuts against the lens barrel. The object-side surface of the first spacer element P1 abuts against the image-side surface S2 of the first lens. The object-side surface and image-side surface of the first auxiliary spacer element P1b abut against the image-side surface of the first spacer element and the object-side surface S3 of the second lens, respectively. The object-side surface and image-side surface of the second spacer element abut against the image-side surface S4 of the second lens and the object-side surface S5 of the third lens, respectively. The object-side surface and image-side surface of the third spacer element abut against the image-side surface S6 of the third lens and the object-side surface S7 of the fourth lens, respectively. The image-side surface S8 of the fourth lens is spaced apart from the lens barrel.

[0108] like Figure 10 The diagram shown is a structural schematic of the optical lens in Embodiment 2-2. The abutment and contact methods of each spacer element are the same as in Embodiment 2-1, and can be referred to the relevant description in Embodiment 2-1, which will not be repeated here.

[0109] like Figure 11The diagram shown is a structural schematic of the optical lens in Embodiment 2-3. In this example, the optical lens does not have a first auxiliary spacer element P1b. The image side of the first spacer element abuts against the object side S3 of the second lens. The bearing and abutting methods of the other spacers are the same as in Embodiment 1-1. Please refer to the relevant description in Embodiment 1-1. It will not be repeated here.

[0110] In summary, the structural parameters of the optical lens of Embodiment 2 under Embodiments 2-1, 2-2, and 2-3 are shown in Table 9.

[0111] In Embodiment 2, the object-side surface S1 of the first lens is concave, and the image-side surface S2 of the first lens is convex. The object-side surface S3 of the second lens is convex, and the image-side surface S4 of the second lens is convex. The object-side surface S5 of the third lens is convex, and the image-side surface S6 of the third lens is concave. The object-side surface S7 of the fourth lens is concave, and the image-side surface S8 of the fourth lens is convex. In Table 4 below, S9 and S10 can be the surfaces of filters or protective glass, while S11 is the imaging surface, and STO is the aperture stop, not shown in the figure.

[0112] Table 4 shows the basic structural parameters of the optical lens in Embodiment 2, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0113]

[0114] Table 4

[0115] Table 5 below shows the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, and A28 that can be used for each aspherical mirror S1-S8 in Example 2. The aspherical surface shape can be defined by formula (1) given in Example 1 above.

[0116] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 A22 A24 A26 A28 S1 2.67E-01 -7.12E-03 4.84E-03 -2.72E-05 2.75E-04 3.54E-06 2.38E-05 3.16E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S2 5.93E-02 2.65E-04 3.79E-04 -4.05E-07 1.80E-05 -1.85E-06 -2.42E-07 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S3 2.29E-03 -1.03E-03 -2.25E-05 -7.81E-06 -6.92E-07 9.02E-08 -4.39E-07 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S4 -7.18E-02 1.16E-02 -2.41E-03 5.14E-04 -1.37E-04 3.64E-05 -6.95E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S5 -1.41E-01 9.29E-03 3.01E-05 4.10E-04 -1.33E-04 6.54E-06 3.36E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S6 -6.92E-02 1.67E-03 1.11E-03 2.18E-04 1.11E-04 6.27E-07 1.75E-05 3.72E-07 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S7 1.60E-01 -9.21E-03 -7.08E-03 9.29E-04 4.34E-05 -9.80E-05 4.40E-05 1.41E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S8 1.98E-01 9.25E-04 -1.16E-02 -9.84E-04 9.62E-04 -6.46E-05 -1.23E-04 -1.31E-05 -2.04E-06 -3.07E-07 0.00E+00 0.00E+00 0.00E+00

[0117] Table 5

[0118] Figure 12 The on-axis chromatic aberration curve of the optical lens of Embodiment 2 is shown, which indicates the deviation of the focal point of light of different wavelengths after passing through the optical lens. Figure 13 The astigmatism curve of the optical lens of Embodiment 2 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 14 The distortion curve of the optical lens in Embodiment 2 is shown, which represents the distortion magnitude value corresponding to different field of view angles. Figure 15 The magnification chromatic aberration curve of the optical lens of Embodiment 2 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the lens.

[0119] according toFigures 12 to 15 It can be seen that the optical lens given in Example 2 can achieve good imaging quality.

[0120] Example 3

[0121] like Figures 16 to 22 As shown, the optical lens of Embodiment 3 is described. Figure 16 A schematic diagram of the optical lens of Embodiment 3-1 is shown. Figure 17 A schematic diagram of the optical lens of Embodiment 3-2 is shown. Figure 18 A schematic diagram of the optical lens of Embodiment 3-3 is shown.

[0122] like Figures 16 to 18 As shown, the optical lens includes a lens barrel, four lenses, and multiple spacer elements. The lens barrel includes a first lens E1, a first spacer element P1, a second lens E2, a second spacer element P2, a third lens E3, a third spacer element P3, a third auxiliary spacer element P3b, and a fourth lens E4, arranged sequentially from the object side to the image side.

[0123] like Figure 16 The diagram shows a schematic of the optical lens structure of Embodiment 3-1. In this example, the object-side surface S1 of the first lens abuts against the lens barrel portion. The object-side surface and image-side surface of the first spacer element P1 abut against the image-side surface S2 of the first lens and the object-side surface S3 of the second lens, respectively. The object-side surface and image-side surface of the second spacer element abut against the image-side surface S4 of the second lens and the object-side surface S5 of the third lens, respectively. The object-side surface and image-side surface of the third spacer element abut against the image-side surface S6 of the third lens and the object-side surface of the third auxiliary spacer element, respectively. The image-side surface of the third auxiliary spacer element abuts against the object-side surface S7 of the fourth lens, and the image-side surface S8 of the fourth lens is spaced apart from the lens barrel.

[0124] like Figure 17 The diagram shown is a structural schematic of the optical lens in Embodiment 3-2. The abutment and contact methods of each spacer element are the same as in Embodiment 3-1, and can be referred to the relevant description in Embodiment 3-1, which will not be repeated here.

[0125] like Figure 18 The diagram shown is a structural schematic of the optical lens in Embodiment 3-3. The abutment and contact method of each spacer element is the same as in Embodiment 3-1, and can be referred to the relevant description in Embodiment 3-1, which will not be repeated here.

[0126] In summary, the structural parameters of the optical lens in Embodiment 3 under Embodiments 3-1, 3-2, and 3-3 are shown in Table 9.

[0127] In Embodiment 3, the object-side surface S1 of the first lens is concave, and the image-side surface S2 of the first lens is convex. The object-side surface S3 of the second lens is convex, and the image-side surface S4 of the second lens is convex. The object-side surface S5 of the third lens is concave, and the image-side surface S6 of the third lens is convex. The object-side surface S7 of the fourth lens is convex, and the image-side surface S8 of the fourth lens is convex. In Table 6 below, S9 and S10 can be the surfaces of filters or protective glass, while S11 is the imaging surface, and STO is the aperture stop, not shown in the figure.

[0128] Table 6 shows the basic structural parameters of the optical lens in Embodiment 3, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0129]

[0130]

[0131] Table 6

[0132] Table 7 below lists the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, and A28 that can be used for each aspherical mirror S1-S8 in Example 3. The surface shape of each aspherical surface can be defined by formula (1) given in Example 1 above.

[0133] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 A22 A24 A26 A28 S1 3.70E-01 -4.14E-02 1.02E-02 -3.66E-03 7.10E-04 -2.96E-04 4.36E-05 2.74E-07 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S2 2.02E-01 -2.76E-02 5.40E-03 -2.14E-03 5.59E-04 -1.49E-04 4.40E-05 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S3 -3.11E-03 -1.55E-04 -4.84E-05 4.21E-06 -1.99E-06 5.10E-06 6.97E-08 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S4 1.12E-01 5.65E-03 1.89E-03 6.49E-04 3.41E-04 1.36E-04 3.39E-05 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S5 2.20E-01 -3.01E-02 2.64E-03 -2.52E-03 2.34E-04 -1.17E-04 3.86E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S6 -4.41E-03 9.83E-03 3.27E-04 -2.49E-03 -8.44E-04 -1.02E-05 1.21E-04 2.09E-05 5.78E-06 1.81E-06 5.44E-07 2.17E-07 0.00E+00 S7 -5.93E-01 1.14E-01 -1.83E-02 4.68E-03 -1.63E-03 1.26E-03 -5.95E-04 -2.41E-05 -1.45E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S8 -5.55E-01 3.73E-02 4.16E-03 6.63E-04 -1.50E-03 1.08E-03 -2.14E-04 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00

[0134] Table 7

[0135] Figure 19 The on-axis chromatic aberration curve of the optical lens of Embodiment 3 is shown, which indicates the deviation of the focal point of light of different wavelengths after passing through the optical lens. Figure 20 The astigmatism curve of the optical lens of Embodiment 3 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 21 The distortion curve of the optical lens in Embodiment 3 is shown, which represents the distortion magnitude value corresponding to different field of view angles. Figure 22 The magnification chromatic aberration curve of the optical lens of Embodiment 3 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the lens.

[0136] according to Figures 19 to 22 It can be seen that the optical lens given in Example 3 can achieve good imaging quality.

[0137] In summary, the optical lenses of Embodiments 1 to 3 respectively satisfy the relationships shown in Table 8.

[0138]

[0139]

[0140] Table 8

[0141] Table 9 shows some parameters (unit: mm) of the optical lenses of Examples 1 to 3.

[0142] Example parameters 1-1 1-2 1-3 2-1 2-2 2-3 3-1 3-2 3-3 d1s 0.421 0.415 0.454 0.900 0.573 0.573 0.719 0.716 0.717 d1m 0.421 0.455 0.414 0.758 0.573 0.613 0.719 0.752 0.753 D1s 2.512 2.632 2.317 1.878 2.814 2.675 1.859 1.805 2.509 D1m 2.512 2.632 2.317 1.855 2.814 2.675 1.859 1.805 2.509 d2s 0.875 0.920 0.850 0.813 0.819 0.820 1.109 1.099 1.085 d2m 0.875 1.056 0.890 0.813 0.819 0.820 1.109 1.135 1.121 D2s 2.572 2.608 2.377 2.059 2.934 2.735 1.959 2.135 2.569 d3s 1.041 1.035 1.184 0.955 0.922 0.936 1.359 1.349 1.302 D3s 2.632 2.812 2.344 2.119 2.994 2.795 2.359 2.222 2.449 d0m 2.798 3.070 2.695 2.376 3.321 3.127 2.852 2.555 3.024 D0s 3.270 3.439 2.940 2.470 3.592 3.349 2.632 2.103 3.423 D0m 3.488 3.736 3.268 2.797 4.030 3.621 3.294 3.094 3.844 EP01 1.104 1.020 1.058 0.854 1.017 0.971 0.656 0.590 0.643 EP12 0.486 0.369 0.478 0.623 0.525 0.555 0.310 0.307 0.304 EP23 0.505 0.450 0.393 0.390 0.460 0.431 0.259 0.248 0.221 f1 -0.98 -0.98 -0.98 -2.47 -2.47 -2.47 -8.99 -8.99 -8.99 f2 77.30 77.30 77.30 1.23 1.23 1.23 1.11 1.11 1.11 f3 0.77 0.77 0.77 9.85 9.85 9.85 -3.15 -3.15 -3.15 f4 -29.68 -29.68 -29.68 1.73 1.73 1.73 1.32 1.32 1.32 f34 0.71 0.71 0.71 1.76 1.76 1.76 1.17 1.17 1.17 f23 0.79 0.79 0.79 1.02 1.02 1.02 2.23 2.23 2.23

[0143] Table 9

[0144] This application also provides an imaging device, whose electronic photosensitive element can be a photocoupled device (CCD) or a complementary metal oxide semiconductor device (CMOS). The imaging device can be a stand-alone imaging device such as a digital camera, or an imaging module integrated into a mobile electronic device such as a mobile phone. The imaging device is equipped with the optical lens described above.

[0145] Obviously, the embodiments described above are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0146] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0147] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0148] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An optical lens, characterized in that, The optical lens is suitable for near-infrared imaging, and includes: a lens barrel and a lens group and a spacer element group disposed within the lens barrel. The lens group consists of four lenses, which are arranged sequentially from the object side to the image side along the optical axis as a first lens, a second lens, a third lens, and a fourth lens. The spacer element group includes at least a second spacer element and a third spacer element, wherein the second spacer element is located between the second lens and the third lens and contacts a portion of the image-side surface of the second lens, and the third spacer element is located between the third lens and the fourth lens and contacts a portion of the image-side surface of the third lens; The inner diameter d0m of the image-side end face of the lens barrel and the radius of curvature R8 of the image-side surface of the fourth lens satisfy the following condition: 2.6≤d0m / |R8|≤8.67; The combined focal length f34 of the third lens and the fourth lens, the center thickness CT4 of the fourth lens on the optical axis, and the minimum distance EP23 between the second spacer element and the third spacer element in the extension direction of the optical axis satisfy the following: 1.04≤f34(EP23+CT4)≤2.

36.

2. The optical lens according to claim 1, characterized in that, The radius of curvature R4 of the image side of the second lens, the refractive index N2 of the second lens, and the outer diameter D2s of the object side of the second spacer element satisfy the following condition: 0.84≤|R4*N2 / D2s|≤2.

83.

3. The optical lens according to claim 1, characterized in that, The radius of curvature R5 of the object side of the third lens and the inner diameter d2m of the image side of the second spacer element satisfy the following condition: 0.18≤|R5| / d2m≤0.

89.

4. The optical lens according to claim 1, characterized in that, The radius of curvature R6 of the image side of the third lens, the outer diameter D3s of the object side of the third spacer element, and the inner diameter d3s of the object side of the third spacer element satisfy the following condition: 0.28≤|R6| / (D3s-d3s)≤0.

81.

5. The optical lens according to claim 1, characterized in that, The central thickness CT3 of the third lens on the optical axis, the air gap T23 between the second and third lenses on the optical axis, and the minimum distance EP23 between the second and third spacers in the extension direction of the optical axis satisfy the following condition: 0.56≤(CT3+T23) / EP23≤2.

06.

6. The optical lens according to claim 1, characterized in that, The radius of curvature R1 of the object side surface of the first lens and the outer diameter D0s of the object side end face of the lens barrel satisfy the following condition: -2.49≤R1 / D0s≤-0.

21.

7. The optical lens according to claim 1, characterized in that, The outer diameter D0m of the image-side end face of the lens tube and the outer diameter D0s of the object-side end face of the lens tube satisfy the following condition: 0.22mm≤D0m-D0s≤0.99mm.

8. The optical lens according to any one of claims 1 to 7, characterized in that, The spacer element group further includes a first spacer element, which is located between the first lens and the second lens and contacts a portion of the image side surface of the first lens. The minimum distance EP01 between the object side end face of the lens barrel and the first spacer element in the optical axis extension direction and the center thickness CT1 of the first lens in the optical axis satisfy the following: 1.9≤EP01 / CT1≤2.

68.

9. The optical lens according to any one of claims 1 to 7, characterized in that, The spacer element group further includes a first spacer element, which is located between the first lens and the second lens and contacts a portion of the image-side surface of the first lens. The radius of curvature R1 of the object-side surface of the first lens, the outer diameter D1s of the object-side surface of the first spacer element, and the inner diameter d1s of the object-side surface of the first spacer element satisfy the following: -3.94≤R1 / (D1s-d1s)≤-0.

33.

10. The optical lens according to any one of claims 1 to 7, characterized in that, The spacer element group further includes a first spacer element, which is located between the first lens and the second lens and contacts a portion of the image side surface of the first lens. The inner diameter d1s of the object side surface of the first spacer element and the radius of curvature R2 of the image side surface of the first lens satisfy the following condition: 1.27≤|R2 / d1s|≤6.

63.

11. The optical lens according to any one of claims 1 to 7, characterized in that, The spacer element group further includes a first spacer element, which is located between the first lens and the second lens and contacts a portion of the image side of the first lens. The air gap T12 between the first lens and the second lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, and the minimum distance EP12 between the first spacer element and the second spacer element in the extension direction of the optical axis satisfy the following: 1.12≤(T12+CT2) / EP12≤2.

21.

12. The optical lens according to any one of claims 1 to 7, characterized in that, The spacer element group further includes a first spacer element, which is located between the first lens and the second lens and contacts a portion of the image side surface of the first lens. The radius of curvature R3 of the object side surface of the second lens, the outer diameter D1m of the image side surface of the first spacer element, and the inner diameter d1m of the image side surface of the first spacer element satisfy the following: 0.44≤R3 / (D1m-d1m)≤1.

48.

13. The optical lens according to any one of claims 1 to 7, characterized in that, The optical lens satisfies at least one of the following: The first lens has negative optical power; The second lens has positive optical power.

14. The optical lens according to any one of claims 1 to 7, characterized in that, The optical lens satisfies at least one of the following: The object-side surface of the first lens is concave; The object-side surface of the second lens is convex.

Images