Optical imaging lens

Abstract

The utility model provides an optical imaging lens. The optical imaging lens can be used for near-infrared band imaging, the optical imaging lens comprises a lens barrel, a lens group and a spacing element group, and the lens group comprises a first lens, a second lens, a third lens and a fourth lens; the spacing element group comprises a first spacing element and a second spacing element, and the effective focal length f2 of the second lens, the center thickness CT2 of the second lens on the optical axis and the distance EP12 between the image side surface of the first spacing element and the object side surface of the second spacing element in the extension direction of the optical axis meet the condition that f2 / (CT2 + EP12) is greater than or equal to 1.03 and less than or equal to 2.88; the curvature radius R3 of the object side surface of the second lens and the outer diameter D1m of the image side surface of the first spacing element satisfy the following relation:-1.93 < = R3 / D1m < =-0.41. According to the utility model, the problem of serious stray light caused by improvement of assembly stability of an optical imaging lens in the prior art is solved.

Description

TECHNICAL FIELD

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

[0002] With the development of electronic products, image system has a pivotal position in electronic products, and users demand more and more image functions of electronic products, especially in AR (Augmented Reality, Augmented Reality), VR (Virtual Reality, Virtual Reality) and other electronic products, the requirements of optical imaging lens are gradually increasing. In the VR / AR system, the eye movement is captured by the optical imaging lens, so that the correct instruction signal is quickly transmitted, which is an important part of the VR / AR system. Accurate signal transmission, stray light quality of optical imaging lens is particularly important. In the optical imaging lens applied to AR, VR products, the relationship between the center thickness and the edge thickness of the lens at the middle position is usually controlled to improve the assembly stability of the optical imaging lens, but it is easy to cause serious stray light.

[0003] That is, the optical imaging lens in the prior art has the problem of improving the assembly stability and causing serious stray light. UTILITY MODEL CONTENT

[0004] The main purpose of the utility model is to provide an optical imaging lens to solve the problem of improving the assembly stability and causing serious stray light in the prior art optical imaging lens.

[0005] In order to achieve the above purpose, according to one aspect of the utility model, an optical imaging lens is provided, the optical imaging lens is used for near-infrared waveband imaging, and the optical imaging lens comprises a lens barrel, a lens group and a spacer element group assembled in the lens barrel. The lens group comprises a first lens, a second lens, a third lens and a fourth lens in sequence from the object side to the image side along the optical axis; the spacer element group comprises 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 in contact with the image side surface of the first lens, and the second spacer element is located between the second lens and the third lens and in contact with the image side surface of the second lens; the effective focal length f2 of the second lens, the center thickness CT2 of the second lens on the optical axis, the distance EP12 between the image side surface of the first spacer element and the object side surface of the second spacer element in the extension direction of the optical axis satisfy: 1.03≤f2 / (CT2+EP12)≤2.88; the curvature radius R3 of the object side surface of the second lens and the outer diameter D1m of the image side surface of the first spacer element satisfy: -1.93≤R3 / D1m≤-0.41.

[0006] According to another aspect of the utility model, provide a kind of optical imaging lens, optical imaging lens is used for near-infrared waveband imaging, optical imaging lens includes lens barrel and the lens group and spacer element group assembled in lens barrel, lens group includes first lens with negative optical power, second lens with positive optical power, third lens with positive optical power and fourth lens with optical power in order from object side to image side along 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 with the image side surface portion of first lens contact;The curvature radius R1 of the object side surface of first lens, the inner diameter d0s of the object side end surface of lens barrel satisfy between-4.37≤R1 / d0s≤-0.66;The air interval T12 of first lens and second lens on optical axis, the central thickness CT1 of first lens, the maximum thickness CP1 of first spacer element satisfy between 0.71≤T12 / (CT1+CP1)≤3.13.

[0007] According to another aspect of the utility model, provide a kind of optical imaging lens, optical imaging lens is used for near-infrared waveband imaging, optical imaging lens includes lens barrel and the lens group and spacer element group assembled in lens barrel, lens group includes first lens with negative optical power, second lens with positive optical power, third lens with positive optical power and fourth lens with optical power in order from object side to image side along optical axis;Spacer element group at least includes second spacer element and third spacer element, second spacer element is located between second lens and third lens and with the image side surface portion of second lens contact, third spacer element is located between third lens and fourth lens and with the image side surface portion of third lens contact;The effective focal length f3 of third lens, the air interval T34 of third lens and fourth lens on optical axis, the distance EP23 between the image side surface of second spacer element and the object side surface of third spacer element in the extension direction of optical axis satisfy between 1.62≤f3 / (EP23+T34)≤14.81;The curvature radius R6 of the image side surface of third lens, the curvature radius R7 of the object side surface of fourth lens, the inner diameter d3s of the object side surface of third spacer element, the inner diameter d3m of the image side surface of third spacer element satisfy between-2.74≤R6 / d3s+R7 / d3m≤-1.65.

[0008] Further, the distance EP01 between the object side end surface of lens barrel and the object side surface of first spacer element in the extension direction of optical axis, the effective focal length f1 of first lens satisfy between-1.73≤f1 / EP01≤-1.34.

[0009] Further, the air interval T12 of first lens and second lens on optical axis, the central thickness CT1 of first lens, the maximum thickness CP1 of first spacer element satisfy between 0.71≤T12 / (CT1+CP1)≤3.13.

[0010] Further, a curvature radius R4 of an image side surface of the second lens, a refractive index N2 of the second lens, and an inner diameter d2s of an object side surface of the second spacer element satisfy -2.63 ≤ R4*N2 / d2s ≤ -0.61.

[0011] Further, an outer diameter D2m of an image side surface of the second spacer element, a curvature radius R6 of an image side surface of the third lens, and a refractive index N3 of the third lens satisfy -2.62 ≤ D2m / (R6*N3) ≤ -1.28.

[0012] Further, a central thickness CT3 of the third lens, an air separation T23 of the second lens and the third lens on the optical axis, and a maximum thickness CP2 of the second spacer element satisfy 0.96 ≤ CT3 / (T23+CP2) ≤ 4.33.

[0013] Further, an outer diameter D0s of an object side end surface of the lens barrel, an inner diameter d0s of the object side end surface of the lens barrel, an outer diameter D0m of an image side end surface of the lens barrel, and an inner diameter d0m of the image side end surface of the lens barrel satisfy 1.41 ≤ (D0m-d0m) / (D0s-d0s) ≤ 3.70.

[0014] Further, a maximum height L of the lens barrel and a sum ∑CT of the central thicknesses of all the lenses in the lens group satisfy 1.64 ≤ L / ∑CT ≤ 2.26.

[0015] Further, a curvature radius R1 of an object side surface of the first lens and an inner diameter d0s of the object side end surface of the lens barrel satisfy -4.37 ≤ R1 / d0s ≤ -0.66.

[0016] Further, the spacer element group further includes a third spacer element, the third spacer element is located between the third lens and the fourth lens and partially contacts an image side surface of the third lens, an effective focal length f3 of the third lens, an air separation T34 of the third lens and the fourth lens on the optical axis, and a distance EP23 of the image side surface of the second spacer element and an object side surface of the third spacer element in the extension direction of the optical axis satisfy 1.62 ≤ f3 / (EP23+T34) ≤ 14.81.

[0017] Further, the spacer element group further includes a third spacer element, the third spacer element is located between the third lens and the fourth lens and partially contacts an image side surface of the third lens, an inner diameter d3s of an object side surface of the third spacer element and a curvature radius R7 of an object side surface of the fourth lens satisfy -2.05 ≤ R7 / d3s ≤ -0.62.

[0018] Further, the first lens has a negative refractive power; the second lens has a positive refractive power; and the third lens has a positive refractive power.

[0019] Further, the object side surface of the first lens is a concave surface, the image side surface of the first lens is a concave surface; the object side surface of the second lens is a concave surface, the image side surface of the second lens is a convex surface; the object side surface of the third lens is a concave surface, the image side surface of the third lens is a convex surface; the object side surface of the fourth lens is a concave surface, the image side surface of the fourth lens is a convex surface.

[0020] The technical scheme of the utility model is applied to near-infrared wave band imaging, and the optical imaging lens comprises a lens barrel, a lens set and a spacer element set assembled in the lens barrel, the lens set comprises a first lens, a second lens, a third lens and a fourth lens in sequence from the object side to the image side along the optical axis, the spacer element set comprises 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 partially contacts the image side surface of the first lens, the second spacer element is located between the second lens and the third lens and partially contacts the image side surface of the second lens, the effective focal length f2 of the second lens, the central thickness CT2 of the second lens on the optical axis, the distance EP12 between the image side surface of the first spacer element and the object side surface of the second spacer element in the extension direction of the optical axis satisfy 1.03≤f2 / (CT2+EP12)≤2.88, and the curvature radius R3 of the object side surface of the second lens and the outer diameter D1m of the image side surface of the first spacer element satisfy -1.93≤R3 / D1m≤-0.41.

[0021] The optical imaging lens of the present application is composed of a lens barrel, four lenses and at least two spacer elements, and when the effective focal length f2 of the second lens, the central thickness CT2 of the second lens on the optical axis, and the distance EP12 between the image side surface of the first spacer element and the object side surface of the second spacer element in the extension direction of the optical axis satisfy 1.03≤f2 / (CT2+EP12)≤2.88, the thickness distribution of the second lens is relatively uniform through the optimization of the focal length, the central thickness of the second lens and the distance between the first spacer element and the second spacer element, which is beneficial to improve the stability of the structure of the second lens and further improve the assembly stability of the optical imaging lens. However, under this design, when the light passes through the second lens, stray light paths are easily generated, resulting in serious stray light. In order to reduce the stray light generated by the optical imaging lens at the second lens, the present application restricts R3 / D1m in a reasonable range to control the curved shape of the object side surface of the second lens, and ensures the transmission path of the light when it enters the second lens. If R3 / D1m is less than -1.93, D1m is small, the curvature radius of the object side surface of the second lens is small, the deflection angle of the light is reduced, and the stray light is easily reflected multiple times at the flange position of the first lens. If R3 / D1m is greater than -0.41, R3 is reduced, and D1m is large, the stray light path is easily directly reflected to the edge position of the image surface, and the stray light energy is high. By limiting R3 / D1m in the range of -1.93 to -0.41, the deflection degree of the light when it enters the second lens is ensured, and the outer diameter D1m of the image side surface of the first spacer element is matched, so that the first spacer element absorbs stray light, reduces the reflection of stray light inside the optical imaging lens, and achieves the purpose of reducing stray light. BRIEF DESCRIPTION OF DRAWINGS

[0022] The drawings accompanying the specification of the present application form a part thereof, serve to provide further understanding of the present application, and together with the specification explain the present application. The use of the same reference numerals in different drawings indicates similar or identical components.

[0023] Figure 1 A size marking diagram of the optical imaging lens of one optional embodiment of the present application is shown;

[0024] Figure 2 A structure schematic diagram of the optical imaging lens of embodiment 1-1 of the present application is shown;

[0025] Figure 3 A structure schematic diagram of the optical imaging lens of embodiment 1-2 of the present application is shown;

[0026] Figures 4 to 7 An on-axis chromatic aberration curve, an astigmatism curve, a distortion curve and a magnification chromatic aberration curve of the optical imaging lens of the embodiment one of the present application are shown respectively;

[0027] Figure 8 A structure schematic view of the optical imaging lens of the embodiment 2-1 of the utility model is shown;

[0028] Figure 9 A structure schematic view of the optical imaging lens of the embodiment 2-2 of the utility model is shown;

[0029] Figures 10 to 13 The on-axis chromatic aberration curve, astigmatism curve, distortion curve and magnification chromatic aberration curve of the optical imaging lens of the embodiment two of the utility model are shown respectively;

[0030] Figure 14 A structure schematic view of the optical imaging lens of the embodiment 3-1 of the utility model is shown;

[0031] Figure 15 A structure schematic view of the optical imaging lens of the embodiment 3-2 of the utility model is shown;

[0032] Figures 16 to 19 The on-axis chromatic aberration curve, astigmatism curve, distortion curve and magnification chromatic aberration curve of the optical imaging lens of the embodiment three of the utility model are shown respectively;

[0033] Figure 20 A structure schematic view of the optical imaging lens of the embodiment 4-1 of the utility model is shown;

[0034] Figure 21 A structure schematic view of the optical imaging lens of the embodiment 4-2 of the utility model is shown;

[0035] Figures 22 to 25 The on-axis chromatic aberration curve, astigmatism curve, distortion curve and magnification chromatic aberration curve of the optical imaging lens of the embodiment four of the utility model are shown respectively;

[0036] Figure 26 A light path diagram of the optical imaging lens of one optional embodiment of the utility model is shown;

[0037] Figure 27 A light path diagram of the optical imaging lens in one example is shown; Figure 26 A stray light spot diagram of the optical imaging lens shown is shown;

[0038] Figure 28 A light path diagram of the optical imaging lens in one example is shown;

[0039] Figure 29 A light path diagram of the optical imaging lens in one example is shown; Figure 28 A stray light spot diagram of the optical imaging lens shown is shown;

[0040] Figure 30 A light path diagram of the optical imaging lens in one example is shown;

[0041] Figure 31 The optical imaging lens is shown. Figure 30 The flare spot diagram of the optical imaging lens is shown.

[0042] In the above drawings, the following reference signs are used:

[0043] P0, lens barrel; E1, first lens; P1, first 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 DESCRIPTION

[0044] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with embodiments.

[0045] It should be noted that, unless otherwise specified, all technical and scientific terms used in the present application have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0046] In the present application, unless otherwise specified, the orientation words such as "upper", "lower", "top", "bottom" are generally directed to the directions shown in the drawings, or are directed to the vertical, perpendicular or gravity directions of the components themselves. Similarly, for the convenience of understanding and description, "inner" and "outer" refer to the inner and outer relative to the contour of each component itself, but the above orientation words are not used to limit the present application.

[0047] It should be noted that in the present specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, the first lens discussed below can also be referred to as the second lens or the third lens without departing from the teachings of the present application.

[0048] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for the convenience of explanation. Specifically, the shape of the spherical surface or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical surface or aspherical surface is not limited to the shape of the spherical surface or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn strictly to scale.

[0049] In the present disclosure, the near-axis region refers to a region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the near-axis region. If the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the near-axis region. The judgment of the surface shape in the near-axis region can be based on the judgment method of those skilled in the art. The convexity or concavity can be judged by the positive or negative value of R (R refers to the radius of curvature in the near-axis region, usually refers to the R value in the lens data of optical software). For the object side surface, when the R value is positive, it is judged as convex, and when the R value is negative, it is judged as concave. For the image side surface, when the R value is positive, it is judged as concave, and when the R value is negative, it is judged as convex. In the present application, the left side is the object side, and the right side is the image side.

[0050] In order to solve the problem of serious stray light caused by improving the assembly stability of the optical imaging lens in the prior art, the utility model provides an optical imaging lens.

[0051] As Figures 1 to 25 shown, the optical imaging lens is used for near-infrared band imaging, and the optical imaging lens comprises a lens barrel, a lens group and a spacer element group assembled in the lens barrel, the lens group comprises a first lens, a second lens, a third lens and a fourth lens in sequence from the object side to the image side along the optical axis, and the spacer element group comprises 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 is in contact with the image side surface part of the first lens, and the second spacer element is located between the second lens and the third lens and is in contact with the image side surface part of the second lens; the effective focal length f2 of the second lens, the central thickness CT2 of the second lens on the optical axis, the distance EP12 between the image side surface of the first spacer element and the object side surface of the second spacer element in the extension direction of the optical axis satisfy: 1.03≤f2 / (CT2+EP12)≤2.88; the curvature radius R3 of the object side surface of the second lens and the outer diameter D1m of the image side surface of the first spacer element satisfy: -1.93≤R3 / D1m≤-0.41.

[0052] The optical imaging lens of the present application is composed of a lens barrel, four lenses and at least two spacer elements. When the effective focal length f2 of the second lens, the central thickness CT2 of the second lens on the optical axis, and the distance EP12 between the image side surface of the first spacer element and the object side surface of the second spacer element in the extension direction of the optical axis satisfy 1.03≤f2 / (CT2+EP12)≤2.88, the thickness distribution of the second lens is relatively uniform through the optimization of the focal length, central thickness and distance between the first spacer element and the second spacer element of the second lens, which is beneficial to improve the stability of the second lens structure and further improve the assembly stability of the optical imaging lens. However, under this design, when the light passes through the second lens, stray light path is easily generated, which leads to serious stray light. In order to reduce the stray light generated by the optical imaging lens at the second lens, the present application restricts R3 / D1m in a reasonable range to control the curved shape of the object side surface of the second lens, which ensures the transmission path of the light when it enters the second lens. If R3 / D1m is less than -1.93, D1m is small, the curvature radius of the object side surface of the second lens is small, the deflection angle of the light is reduced, and the stray light is easily reflected multiple times at the flange position of the first lens. If R3 / D1m is greater than -0.41, R3 is reduced, and D1m is large, the stray light path is easily directly reflected to the edge position of the image surface, which easily leads to high stray light energy. By limiting R3 / D1m in the range of -1.93 to -0.41, the deflection degree of the light when it enters the second lens is ensured, and the outer diameter D1m of the image side surface of the first spacer element is matched, so that the first spacer element absorbs stray light, reduces the reflection of stray light inside the optical imaging lens, and achieves the purpose of reducing stray light.

[0053] In addition, referring to Table 1 and Figures 26 to 31 shown below, Figure 26 the optical imaging lens light path schematic diagram satisfying f2 / (CT2+EP12)=1.88, R3 / D1m=-0.45 is shown, Figure 27 isthe stray light schematic diagram of the optical imaging lens. Figure 26

[0054] Figure 28 the optical imaging lens light path schematic diagram satisfying f2 / (CT2+EP12)=1.88, R3 / D1m=-2.1 is shown, Figure 29 isthe stray light schematic diagram of the optical imaging lens. Figure 28 Figure 30 the optical imaging lens light path schematic diagram satisfying f2 / (CT2+EP12)=1.88, R3 / D1m=-0.3 is shown, Figure 31 isthe stray light schematic diagram of the optical imaging lens. Figure 30

[0055] Figures 26 to 31 ​It can be seen that when R3 / D1m=-0.45, the stray light energy is reduced, the stray light is improved, and the performance is better. When R3 / D1m=-2.1 is satisfied, stray light is easily generated at the position of the first spacer element, the stray light energy is strong, the stray light has a greater impact on the imaging quality, and the performance is poor. When R3 / D1m=-0.3 is satisfied, stray light is easily generated between the second lens and the first lens, the stray light energy is strong, the stray light has a greater impact on the imaging quality, and the performance is poor. It can be seen that when (R1*N1) / (D1s-d1s) is in the range of-4.13 to 0.89, the stray light improvement effect of the optical imaging lens is best. Therefore, by restricting-1.93≤R3 / D1m≤-0.41, the relationship between the curvature radius of the object side of the second lens and the inner diameter of the first spacer element is reasonably constrained, which is conducive to reducing the stray light generated at the second lens and the first spacer element, thereby weakening the influence of stray light on the imaging quality and ensuring the imaging quality of the optical imaging lens.

[0056]

[0057] Table 1

[0058] It should be noted that the present application limits R3 / D1m to a reasonable range to control the deflection degree of light at the object side of the second lens and the size of the first spacer element, improve the smoothness of the light path, and solve the stray light problem when f2 / (CT2+EP12) is in the range of 1.03 to 2.88. When R3 / D1m satisfies the above range, the purpose of reducing stray light can be achieved, and it does not depend on the optical power of the lens and the surface shape of the lens. The optical power and surface shape of the lens are further optimized on this basis. 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 be convex or concave according to the design requirements of the optical system. When the optical system satisfies 1.03≤f2 / (CT2+EP12)≤2.88 and-1.93≤R3 / D1m≤-0.41, the purpose of reducing stray light can be achieved.

[0059] For example, the first lens has a negative optical power, the second lens has a positive optical power, and the third lens has a positive optical power. For another example, the object side surface of the first lens is a concave surface, the image side surface of the first lens is a concave surface; the object side surface of the second lens is a concave surface, the image side surface of the second lens is a convex surface; the object side surface of the third lens is a concave surface, the image side surface of the third lens is a convex surface; the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a convex surface. The optical imaging lens can be simulated by software and / or tools such as ZEMAX, CODEV, etc. In the process of simulation by software and / or tools such as the above, the surface shape of each lens can be simulated according to the surface shape provided by the software and / or tools used and appropriately adjusted.

[0060] In some optional embodiments, the optical imaging lens is used for imaging light with a wavelength greater than or equal to 780 nm and less than or equal to 2526 nm, and the optical imaging lens can image light in the near-infrared band, thereby effectively increasing the application environment of the optical imaging lens.

[0061] In some optional embodiments, a distance EP01 between the object-side end surface of the lens barrel and the object-side surface of the first spacer element in the extension direction of the optical axis, and an effective focal length f1 of the first lens satisfy: -1.73≤f1 / EP01≤-1.34. By limiting f1 / EP01 within a reasonable range, the edge thickness of the first lens and the point gluing space reserved in front of the first lens can be guaranteed, while the degree of deflection of light in the first lens is controlled, which is conducive to being matched with the second lens having positive refractive power behind to ensure the smooth transition of light between the first lens and the second lens and to ensure the imaging quality. Reserving sufficient point gluing space in front of the first lens can prevent the lens from having appearance problems such as overflow, while guaranteeing the edge thickness of the first lens to ensure the molding quality of the first lens and reduce appearance problems in the molding of the first lens.

[0062] In some optional embodiments, an air gap T12 between the first lens and the second lens on the optical axis, a center thickness CT1 of the first lens, and a maximum thickness CP1 of the first spacer element satisfy: 0.71≤T12 / (CT1+CP1)≤3.13. By limiting T12 / (CT1+CP1) within a reasonable range, a larger spacing between the first lens and the second lens is guaranteed, which is conducive to preventing the first lens from floating after the optical imaging lens is baked and adversely affecting the assembly stability of the optical imaging lens, while limiting the center thickness of the first lens and the maximum thickness of the first spacer element, which is conducive to reducing the influence of the center thickness tolerance of the first lens and the sagitta tolerance of the image-side surface on the production yield of the optical imaging lens.

[0063] In some optional embodiments, a curvature radius R4 of the image-side surface of the second lens, a refractive index N2 of the second lens, and an inner diameter d2s of the object-side surface of the second spacer element satisfy: -2.63≤R4*N2 / d2s≤-0.61. By limiting R4*N2 / d2s within a reasonable range, the degree of deflection of light passing through the image-side surface of the second lens can be guaranteed, so that the imaging light smoothly passes through the second spacer element while the second spacer element effectively intercepts stray light generated at the flange surface of the second lens, thereby improving the improvement effect of the optical imaging lens on stray light. In addition, the image-side surface of the second lens is set as a convex surface, which is conducive to the convergence of light at the diaphragm.

[0064] In some alternative embodiments, an image-side surface outer diameter D2m of the second spacer element, a radius of curvature R6 of an image-side surface of the third lens, and a refractive index N3 of the third lens satisfy: -2.62≤D2m / (R6*N3)≤-1.28. By limiting D2m / (R6*N3) within a reasonable range, the reflected light from the second lens flange surface into the third lens can be weakened, while controlling the degree of deflection of light in the third lens, the ghost spot generated by the third lens can be minimized, and the imaging quality of the optical imaging lens is ensured.

[0065] In some alternative embodiments, a central thickness CT3 of the third lens, an air gap T23 of the second lens and the third lens on the optical axis, and a maximum thickness CP2 of the second spacer element satisfy: 0.96≤CT3 / (T23+CP2)≤4.33. Since the air gap between the second lens and the third lens is sensitive to the optical performance, mainly affecting the curvature of field in the outer field of view, by limiting the relationship between the central thickness of the third lens, the air gap between the second lens and the third lens on the optical axis, and the maximum thickness of the second spacer element, the sensitivity of the thickness of the third lens and the air gap between the second lens and the third lens to the optical performance can be reduced.

[0066] In some alternative embodiments, an outer diameter D0s of the object-side end surface of the lens barrel, an inner diameter d0s of the object-side end surface of the lens barrel, an outer diameter D0m of the image-side end surface of the lens barrel, and an inner diameter d0m of the image-side end surface of the lens barrel satisfy: 1.41≤(D0m-d0m) / (D0s-d0s)≤3.70. By restricting (D0m-d0m) / (D0s-d0s) within a reasonable range, the external shape of the optical imaging lens can be ensured, on the one hand, the small head feature can be realized, so that the optical imaging lens can be applied to more application scenarios, on the other hand, the outer diameter of the small head end lens barrel can be increased, and the assembly stability of the optical imaging lens can be improved.

[0067] In some alternative embodiments, a maximum height L of the lens barrel and a sum ∑CT of the central thicknesses of all lenses in the lens group satisfy: 1.64≤L / ∑CT≤2.26. By limiting L / ∑CT within a reasonable range, the proportion of the sum of the central thicknesses of the lenses in the lens group to the maximum height of the lens barrel can be ensured, the reasonable distribution of the air gap and the central thickness of the lens in the lens group is ensured, and the stability of the air gap of the optical imaging lens before and after baking is improved, and the optical performance of the optical imaging lens is ensured.

[0068] In some optional embodiments, a relationship between a radius of curvature R1 of the object side surface of the first lens and an inner diameter d0sof the object side end surface of the lens barrel satisfies -4.37≤R1 / d0s≤-0.66. By limiting R1 / d0s within a reasonable range, the bending degree of the object side surface of the first lens is guaranteed, the field angle of the optical imaging lens is guaranteed, and the inner diameter of the object side end surface of the lens barrel is limited to avoid the lens barrel intercepting light, affecting the imaging brightness, and guaranteeing the luminous flux of the optical imaging lens.

[0069] In some optional embodiments, the set of spacer elements further includes a third spacer element located between the third lens and the fourth lens and in contact with a part of the image side surface of the third lens, a relationship between an effective focal length f3 of the third lens, an air separation T34 of the third lens and the fourth lens on the optical axis, and a distance EP23 of the image side surface of the second spacer element and the object side surface of the third spacer element in the extension direction of the optical axis satisfies 1.62≤f3 / (EP23+T34)≤14.81. By limiting f3 / (EP23+T34) within a reasonable range, the degree of deflection of light in the third lens is controlled, and the air separation of the third lens and the fourth lens on the optical axis is matched to provide space for improving the stray light emitted by the third lens, guarantee the effect of stray light improvement of the optical imaging lens, and guarantee the molding of the third lens to guarantee the yield of the third lens.

[0070] In some optional embodiments, the set of spacer elements further includes a third spacer element located between the third lens and the fourth lens and in contact with a part of the image side surface of the third lens, a relationship between an inner diameter d3s of the object side surface of the third spacer element and a radius of curvature R7 of the object side surface of the fourth lens satisfies -2.05≤R7 / d3s≤-0.62. By limiting R7 / d3s within a reasonable range, the degree of deflection of light on the object side surface of the fourth lens is controlled, the stray light path emitted by the third lens is intercepted by the third spacer element to reduce the stray light reaching the imaging surface, and the imaging quality of the optical imaging lens is guaranteed.

[0071] In another optional embodiment of the present application, an optical imaging lens is also provided. The optical imaging lens is used for near-infrared band imaging. The optical imaging lens comprises a lens barrel, a lens set and a spacer element set assembled in the lens barrel. The lens set comprises, in sequence from the object side to the image side along the optical axis, a first lens with negative refractive power, a second lens with positive refractive power, a third lens with positive refractive power, and a fourth lens with refractive power. The spacer element set comprises at least a first spacer element. The first spacer element is located between the first lens and the second lens and is in contact with the image side surface of the first lens. The radius of curvature R1 of the object side surface of the first lens and the inner diameter d0s of the object side end surface of the lens barrel satisfy -4.37≤R1 / d0s≤-0.66. The air gap T12 of the first lens and the second lens on the optical axis, the center thickness CT1 of the first lens, and the maximum thickness CP1 of the first spacer element satisfy 0.71≤T12 / (CT1+CP1)≤3.13.

[0072] The optical imaging lens of the present application is composed of a lens barrel, four lenses and at least one spacer element. When the radius of curvature R1 of the object side surface of the first lens and the inner diameter d0s of the object side end surface of the lens barrel satisfy -4.37≤R1 / d0s≤-0.66, the curvature of the object side surface of the first lens and the inner diameter of the object side end surface of the lens barrel are optimized, so that the object side surface of the first lens can receive more light, which is beneficial to the incidence of large-angle light into the optical lens and the improvement of the imaging brightness and the field of view angle of the optical lens. However, due to the large inner diameter d0s of the object side end surface of the lens barrel, the first lens is prone to tilt and misalignment during installation, which affects the assembly stability of the optical imaging lens. By restricting T12 / (CT1+CP1) within a reasonable range, the present application ensures that the first lens and the second lens have a large spacing, which is beneficial to prevent the first lens from floating after the optical imaging lens is baked and affecting the assembly stability of the optical imaging lens. At the same time, the center thickness of the first lens and the thickness of the first spacer element are limited to ensure the support strength of the first lens and the structural strength of the first lens, which is beneficial to improve the stability of the first lens assembly.

[0073] Of course, the present embodiment can also include other parameter formulas in the above embodiments, which will not be described here.

[0074] In addition, in another optional embodiment of the present application, an optical imaging lens is also provided, the optical imaging lens is used for near-infrared wave band imaging, and the optical imaging lens comprises a lens barrel, a lens group and a spacer element group assembled in the lens barrel. The lens group comprises, in sequence from the object side to the image side along the optical axis, a first lens with negative refractive power, a second lens with positive refractive power, a third lens with positive refractive power and a fourth lens with refractive power. 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 is in contact with 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 the image side surface of the third lens. The effective focal length f3 of the third lens, the air interval T34 of the third lens and the fourth lens on the optical axis, and the distance EP23 between the image side surface of the second spacer element and the object side surface of the third spacer element in the extension direction of the optical axis satisfy: 1.62≤f3 / (EP23+T34)≤14.81. The curvature radius R6 of the image side surface of the third lens, the curvature radius R7 of the object side surface of the fourth lens, the inner diameter d3s of the object side surface of the third spacer element, and the inner diameter d3m of the image side surface of the third spacer element satisfy: -2.74≤R6 / d3s+R7 / d3m≤-1.65.

[0075] The optical imaging lens of the present application is composed of a lens barrel, four lenses and at least two spacer elements. When the effective focal length f3 of the third lens, the air interval T34 of the third lens and the fourth lens on the optical axis, and the distance EP23 between the image side surface of the second spacer element and the object side surface of the third spacer element in the extension direction of the optical axis satisfy: 1.62≤f3 / (EP23+T34)≤14.81, the optimization of the focal length of the third lens, the air interval between the third lens and the fourth lens, and the distance between the second spacer element and the third spacer element is beneficial to control the deflection degree of light when entering and exiting the third lens, while limiting the relationship between f3, EP23 and T34, which can ensure the molding of the third lens, ensure the yield of the third lens, and provide space for improving the stray light exiting the third lens. However, the constraint of f3 / (EP23+T34) in the above range has a poor effect on the improvement of stray light. The present application also constrains the relationship between the curvature radius of the image side surface of the third lens, the curvature radius of the object side surface of the fourth lens and the inner diameter of the third spacer element, which can optimize the exiting angle and direction of light from the third lens, and the incident angle and direction of light entering the fourth lens, and optimize the transmission path, angle and range of maximum light between the third lens and the fourth lens. In combination with the constraint of f3 / (EP23+T34) on the space between the third lens and the fourth lens, the stray light is further reduced, and the imaging quality of the optical imaging lens is improved.

[0076] Of course, other parameter expressions in the above embodiments can also be included in the present embodiment, which will not be described here.

[0077] In some alternative embodiments, the plurality of lenses can include at least one cut lens, the outer periphery of the cut lens can have a cut portion and a non-cut portion, and the outer diameter of the cut portion of the lens is smaller than the outer diameter of the non-cut portion of the lens. When the outer periphery of the lens has a cut portion, the outer diameter of the lens generally refers to the outer diameter of the non-cut portion of the lens.

[0078] In some alternative embodiments, the plurality of spacing elements can include at least one cut spacing element. The outer periphery of the cut spacing element can have a cut portion and a non-cut portion, and the outer diameter of the cut portion of the cut spacing element is smaller than the outer diameter of the non-cut portion of the cut spacing element. The outer diameter of the spacing element generally refers to the maximum outer diameter that is not cut by the cut portion.

[0079] Optionally, the optical imaging lens can further include a protective glass for protecting the photosensitive element located on the imaging surface.

[0080] The optical imaging lens in the present application can employ a plurality of lenses, for example, four lenses as described above. In the present application, at least one of the lens surfaces of each lens is a non-spherical lens surface. The characteristic of the non-spherical lens is that the curvature continuously changes from the center of the lens to the periphery of the lens. Unlike the spherical lens which has a constant curvature from the center of the lens to the periphery of the lens, the non-spherical lens has better curvature radius characteristics, which has the advantages of improving the distortion aberration and improving the astigmatism aberration. After using the non-spherical lens, the aberration that occurs during imaging can be eliminated as much as possible, thereby improving the imaging quality.

[0081] However, those skilled in the art should understand that the number of lenses constituting the optical imaging lens can be changed without departing from the technical solutions claimed by the present application, to obtain the various results and advantages described in the present specification. For example, although the four lenses are described as an example in the embodiments, the optical imaging lens is not limited to including four lenses. If necessary, the optical imaging lens can also include other numbers of lenses.

[0082] Figure 1 The size annotation diagram of one optical imaging lens of the present application is shown, Figure 1 The parameters D1m, d2s, D2m, d3s, d0s, d0m, D0s, D0m, CP1, CP2, EP01, EP12, EP23, L, etc. are marked in the figure, so that the meaning of the parameters can be clearly and intuitively understood. In order to facilitate the description of the optical imaging lens and the surface type of the specific lens, these parameters will not be embodied in the figure when the specific embodiments are described later.

[0083] The specific surface shape and parameters of the optical imaging lens applicable to the above embodiments are further described below with reference to the accompanying drawings.

[0084] It should be noted that there are two examples, example 1-1 and example 1-2, in the following embodiment one, two examples, example 2-1 and example 2-2, in the following embodiment two, two examples, example 3-1 and example 3-2, in the following embodiment three, and two examples, example 4-1 and example 4-2, in the following embodiment four. The curvature radius, center thickness and other parameters of the first lens to the fourth lens of the optical imaging lens in the two examples in the same embodiment are the same, but the thickness, inner diameter and outer diameter of the lens barrel, the first spacing element, the second spacing element and the third spacing element and the shape of part of the lens are different. Or, the main structure for imaging is the same, and the auxiliary structure for imaging is different.

[0085] It should be noted that any one of the following embodiments one to three is applicable to the present application.

[0086] Embodiment one

[0087] As shown in Figures 2 to 7 , the optical imaging lens of embodiment one is described. Figure 2 The structural schematic diagram of the optical imaging lens of example 1-1 is shown, Figure 3 The structural schematic diagram of the optical imaging lens of example 1-2 is shown.

[0088] As shown in Figure 2 and Figure 3 , the optical imaging lens includes a lens barrel P0, four lenses and a plurality of spacing elements, the lens barrel P0 includes, in order from the object side to the image side, a first lens E1, a first spacing element P1, a second lens E2, a second spacing element P2, a third lens E3, a third spacing element P3 and a fourth lens E4.

[0089] As shown in Figure 2 , the optical imaging lens includes a lens barrel P0, four lenses and a plurality of spacing elements, the lens barrel P0 includes, in order from the object side to the image side, a first lens E1, a first spacing element P1, a second lens E2, a second spacing element P2, a third lens E3, a third spacing element P3 and a fourth lens E4.As shown in FIG. 1, it is a structure schematic diagram of the optical imaging lens of embodiment 1-1. In embodiment 1-1, the spacer element group further comprises a second auxiliary spacer element P2b, and the second auxiliary spacer element P2b is located between the second spacer element P2 and the third lens E3. The object side S1 of the first lens is spaced apart from the lens barrel P0, and the outer annular surface of the first lens E1 partially abuts the inner wall surface of the lens barrel P0. The object side and the image side of the first spacer element P1 partially abut the image side S2 of the first lens and the object side S3 of the second lens, respectively. The object side and the image side of the second spacer element P2 partially abut the image side S4 of the second lens and the object side of the second auxiliary spacer element P2b, respectively, and the image side of the second auxiliary spacer element P2b partially abuts the object side S5 of the third lens. The object side and the image side of the third spacer element P3 partially abut the image side S6 of the third lens and the object side S7 of the fourth lens, respectively, and the image side S8 of the fourth lens partially abuts the lens barrel P0.

[0090] As shown in FIG. 2, it is a structure schematic diagram of the optical imaging lens of embodiment 1-2. In embodiment 1-2, the spacer element group does not have the second auxiliary spacer element P2b, but the spacer element group further comprises a third auxiliary spacer element P3b, and the third auxiliary spacer element P3b is located between the third spacer element P3 and the fourth lens E4. In embodiment 1-2, the image side of the second spacer element P2 partially abuts the object side S5 of the third lens. The object side and the image side of the third auxiliary spacer element P3b partially abut the image side of the third spacer element and the object side S7 of the fourth lens, respectively. The abutting modes of the other spacer elements are similar to those of embodiment 1-1, and the related descriptions in embodiment 1-1 can be referred to, which will not be described here. Figure 3

[0091] In embodiment one, the first lens has a negative focal power, the object side S1 of the first lens is a concave surface, and the image side S2 of the first lens is a concave surface. The second lens has a positive focal power, the object side S3 of the second lens is a concave surface, and the image side S4 of the second lens is a convex surface. The third lens has a positive focal power, the object side S5 of the third lens is a concave surface, and the image side S6 of the third lens is a convex surface. The fourth lens has a positive focal power, the object side S7 of the fourth lens is a concave surface, and the image side S8 of the fourth lens is a convex surface.

[0092] Table 2 shows the basic structure parameter table of the optical imaging lens of embodiment one, wherein the units of the curvature radius and the thickness / distance are millimeters (mm).

[0093]

[0094]

[0095] Table 2

[0096] ​In embodiment one, the object side and the image side of the first lens E1 to the fourth lens E4 are aspherical surfaces, and the surface shape of each aspherical surface can be defined by, but not limited to, the following aspherical surface formula:

[0097]

[0098] wherein x is the sag of the aspherical surface at a position along the optical axis with a height of h, c is the paraxial curvature of the aspherical surface, c = 1 / R, i.e., the paraxial curvature c is the inverse of the curvature radius R in Table 1 above, k is the conic coefficient, and Ai is the correction coefficient of the i-th order of the aspherical surface. Table 3 below provides the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28 that can be used for the aspherical surfaces S1-S8 in embodiment one.

[0099] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 A22 A24 A26 A28 S1 3.13E-01 -5.79E-02 1.10E-02 -4.10E-03 1.36E-03 -5.26E-04 1.69E-04 -8.79E-05 2.45E-05 -1.90E-06 5.24E-06 0.00E+00 0.00E+00 S2 1.44E-01 -2.32E-02 -7.42E-03 -4.32E-03 -1.13E-03 -2.66E-04 -3.55E-05 -5.67E-07 -1.86E-05 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S3 -2.76E-02 1.02E-03 1.97E-04 4.67E-05 2.39E-05 9.54E-06 7.27E-06 -1.18E-06 1.52E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S4 -3.13E-02 -4.56E-04 3.03E-04 -2.08E-04 8.25E-05 -2.82E-05 1.03E-05 -4.21E-06 1.84E-06 -9.17E-07 1.34E-07 0.00E+00 0.00E+00 S5 2.63E-02 -4.83E-03 6.21E-04 -1.98E-04 3.68E-05 -1.09E-05 1.93E-06 -6.11E-07 -7.12E-07 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S6 -1.31E-02 -1.18E-03 -3.14E-05 -4.86E-05 4.97E-06 -3.08E-06 -5.97E-07 2.57E-07 -1.98E-07 -4.99E-07 2.63E-07 0.00E+00 0.00E+00 S7 1.40E-02 2.61E-03 2.19E-04 8.15E-05 4.02E-05 8.98E-06 -3.19E-06 -3.11E-06 -1.29E-08 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S8 6.89E-02 8.39E-03 1.16E-03 3.67E-04 1.76E-04 5.32E-05 1.53E-05 1.35E-06 4.83E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00

[0100] Table 3

[0101] Figure 4 The axial chromatic aberration curve of the optical imaging lens in embodiment one is shown, which represents the deviation of the converging focal points of light rays of different wavelengths after passing through the optical imaging lens. Figure 5 The astigmatism curve of the optical imaging lens in embodiment one is shown, which represents the meridional image curvature and sagittal image curvature. Figure 6 The distortion curve of the optical imaging lens in embodiment one is shown, which represents the distortion size values corresponding to different field angles. Figure 7 The lateral chromatic aberration curve of the optical imaging lens in embodiment one is shown, which represents the deviation of the image height of light rays after passing through the lens.

[0102] According to Figures 4 to 7 It can be seen that the optical imaging lens given in embodiment one can achieve good imaging quality.

[0103] Embodiment two

[0104] As Figures 8 to 13 shown, the optical imaging lens in embodiment two is described. Figure 8 The structural schematic diagram of the optical imaging lens in embodiment 2-1 is shown, Figure 9 The structural schematic diagram of the optical imaging lens in embodiment 2-2 is shown.

[0105] As Figure 8 and Figure 9As shown, the optical imaging lens includes a lens barrel P0, four lenses and multiple spacer elements. The lens barrel P0 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.

[0106] like Figure 8 The diagram shows a schematic of the optical imaging lens in Embodiment 2-1. The object-side surface S1 of the first lens is spaced apart from the lens barrel P0, and the outer ring surface of the first lens E1 partially abuts against the inner wall surface of the lens barrel P0. The object-side surface and image-side surface of the first spacer element P1 partially 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 P2 partially 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 P3 partially 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 partially abuts against the lens barrel P0.

[0107] like Figure 9 The diagram shown is a structural schematic of the optical imaging lens of Embodiment 2-2. In Embodiment 2-2, the abutment and contact method of each spacer element is similar to that of Embodiment 2-1, and can be referred to the relevant description in Embodiment 2-1, which will not be repeated here.

[0108] In Embodiment 2, the first lens has negative optical power, and its object-side surface S1 and image-side surface S2 are both concave. The second lens has positive optical power, its object-side surface S3 is concave, and its image-side surface S4 is convex. The third lens has positive optical power, its object-side surface S5 is concave, and its image-side surface S6 is convex. The fourth lens has negative optical power, its object-side surface S7 is concave, and its image-side surface S8 is convex.

[0109] Table 4 shows the basic structural parameters of the optical imaging lens in Embodiment 2, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0110]

[0111] Table 4

[0112] Table 5 shows the higher-order coefficients that can be used for each aspherical mirror in Embodiment 2, wherein each aspherical surface shape can be defined by formula (1) given in Embodiment 1 above. In this embodiment, the object-side and image-side surfaces of the first to fourth lenses are all aspherical.

[0113] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 A22 A24 A26 A28 S1 3.29E-01 -5.98E-02 1.34E-02 -4.66E-03 1.83E-03 -5.91E-04 2.46E-04 -7.13E-05 6.07E-05 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S2 1.64E-01 -1.70E-02 -8.18E-03 -3.75E-03 -1.12E-04 5.67E-04 2.78E-04 5.59E-05 -2.26E-05 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S3 -2.17E-02 7.11E-04 7.96E-05 7.24E-05 -6.29E-06 -1.69E-07 3.02E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S4 4.99E-02 -2.44E-03 1.08E-03 -1.10E-04 4.67E-05 -7.74E-06 3.69E-07 -2.99E-06 -4.44E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S5 4.74E-02 -6.83E-03 9.27E-04 -2.95E-04 4.98E-05 -1.90E-05 2.78E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S6 6.52E-04 -8.88E-04 1.02E-04 -7.48E-05 1.30E-05 -5.66E-06 7.38E-07 2.61E-08 9.74E-07 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S7 1.71E-02 -8.47E-04 -2.33E-05 -3.20E-05 2.89E-05 6.01E-06 -1.81E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S8 5.07E-02 4.43E-05 -2.84E-04 -2.27E-05 3.57E-05 3.59E-06 -9.82E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00

[0114] Table 5

[0115] Figure 10 On-axis chromatic aberration curves of the optical imaging lens of embodiment two are shown, which represent the convergence point deviation of light rays of different wavelengths after passing through the optical imaging lens. Figure 11 Astigmatism curves of the optical imaging lens of embodiment two are shown, which represent the meridional image curvature and sagittal image curvature. Figure 12 Distortion curves of the optical imaging lens of embodiment two are shown, which represent the distortion size values corresponding to different field angles. Figure 13 Magnification chromatic aberration curves of the optical imaging lens of embodiment two are shown, which represent the deviation of different image heights of light rays on the imaging plane after passing through the lens.

[0116] According to Figures 10 to 13 It can be known that the optical imaging lens given by embodiment two can achieve good imaging quality.

[0117] Embodiment three

[0118] As Figures 14 to 19 shown, the optical imaging lens of embodiment three is described. Figure 14 A structural schematic diagram of the optical imaging lens of embodiment 3-1 is shown, Figure 15 A structural schematic diagram of the optical imaging lens of embodiment 3-2 is shown.

[0119] As Figure 14 and Figure 15 shown, the optical imaging lens includes a lens barrel P0, four lenses, and a plurality of spacer elements, the lens barrel P0 includes, in order from the object side to the image side, 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.

[0120] As Figure 14 shown, it is a structural schematic diagram of the optical imaging lens of embodiment 3-1. The object side surface S1 of the first lens is arranged apart from the lens barrel P0, and the outer annular surface of the first lens E1 partially abuts the inner wall surface of the lens barrel P0. The object side surface and the image side surface of the first spacer element P1 partially abut 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 the image side surface of the second spacer element P2 partially abut 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 the image side surface of the third spacer element P3 partially abut 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 partially abuts the lens barrel P0.

[0121] As Figure 15Fig. 3 shows a structure diagram of the optical imaging lens of embodiment 3-2. In embodiment 3-2, the spacer element group further comprises a third auxiliary spacer element P3b, which is located between the third spacer element P3 and the fourth lens E4. In embodiment 3-2, the image side surface of the second spacer element P2 partially abuts against the object side surface S5 of the third lens. The object side surface and the image side surface of the third auxiliary spacer element P3b partially abut against the image side surface of the third spacer element and the object side surface S7 of the fourth lens, respectively. The abutting modes of other spacer elements are similar to those of embodiment 3-1, and the related descriptions can be referred to embodiment 3-1, which will not be repeated here.

[0122] In embodiment three, the first lens has negative refractive power, the object side surface S1 of the first lens is concave, and the image side surface S2 of the first lens is concave. The second lens has positive refractive power, the object side surface S3 of the second lens is concave, and the image side surface S4 of the second lens is convex. The third lens has positive refractive power, the object side surface S5 of the third lens is concave, and the image side surface S6 of the third lens is convex. The fourth lens has positive refractive power, the object side surface S7 of the fourth lens is concave, and the image side surface S8 of the fourth lens is convex.

[0123] Table 6 shows the basic structure parameter table of the optical imaging lens of embodiment three, wherein the units of the curvature radius and the thickness / distance are millimeters (mm).

[0124]

[0125] Table 6

[0126] Table 7 shows the high-order term coefficients of the aspherical surfaces that can be used in embodiment three, wherein each aspherical surface can be defined by the formula (1) given in embodiment one. In this embodiment, the object side surface and the image side surface of the first lens to the fourth lens are aspherical surfaces.

[0127] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 A22 A24 A26 A28 S1 3.15E-01 -3.38E-02 7.99E-03 -2.16E-03 8.48E-04 -1.51E-04 8.62E-05 -3.29E-05 1.01E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S2 1.52E-01 -8.22E-03 6.71E-04 -2.42E-03 -2.57E-05 -1.23E-04 1.08E-04 -1.91E-05 1.03E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S3 -1.17E-03 1.84E-03 -1.92E-04 8.52E-06 -1.89E-07 2.05E-09 -8.59E-12 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S4 4.15E-02 -3.76E-04 9.52E-04 4.16E-05 6.97E-05 1.29E-05 7.39E-06 -2.51E-07 -1.36E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S5 2.52E-02 -3.72E-03 4.29E-04 -1.25E-04 1.41E-05 -9.63E-08 -3.34E-08 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S6 -1.84E-03 5.03E-04 7.47E-06 -4.19E-05 1.08E-05 -9.32E-07 -3.61E-09 5.16E-09 -2.22E-10 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S7 1.13E-02 4.09E-04 -6.51E-04 1.67E-05 5.24E-05 1.20E-05 -5.14E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S8 5.36E-02 -5.27E-04 -1.34E-03 7.18E-05 9.10E-05 -2.84E-06 -1.28E-05 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00

[0128] Table 7

[0129] Figure 16 Fig. 11 shows the axial chromatic aberration curve of the optical imaging lens of embodiment three, which represents the deviation of the converging focal points of light rays with different wavelengths after passing through the optical imaging lens. Figure 17 Fig. 12 shows the astigmatism curve of the optical imaging lens of embodiment three, which represents the meridional image surface curvature and the sagittal image surface curvature. Figure 18 Fig. 13 shows the distortion curve of the optical imaging lens of embodiment three, which represents the distortion size values corresponding to different field angles. Figure 19 Fig. 14 shows the magnification chromatic aberration curve of the optical imaging lens of embodiment three, which represents the deviation of the image height of light rays after passing through the lens.

[0130] According toFigures 16 to 19 It can be seen that the optical imaging lens provided in Embodiment Three can achieve good imaging quality.

[0131] Embodiment Four

[0132] As shown in Figures 20 to 25 , the optical imaging lens of Embodiment Four is described. Figure 20 A structural schematic diagram of the optical imaging lens of Embodiment 4-1 is shown, Figure 21 A structural schematic diagram of the optical imaging lens of Embodiment 4-2 is shown.

[0133] As shown in Figure 20 and Figure 21 , the optical imaging lens includes a lens barrel P0, four lenses, and multiple spacer elements, the lens barrel P0 includes, in order from the object side to the image side, 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.

[0134] As shown in Figure 20 , it is a structural schematic diagram of the optical imaging lens of Embodiment 4-1. The object side surface S1 of the first lens is arranged apart from the lens barrel P0, and the outer annular surface of the first lens E1 partially abuts the inner wall surface of the lens barrel P0. The object side surface and the image side surface of the first spacer element P1 partially abut 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 the image side surface of the second spacer element P2 partially abut the image side surface S4 of the second lens and the object side surface S5 of the third lens, respectively. The object side surface of the third spacer element P3 partially abuts the image side surface S6 of the third lens. The object side surface and the image side surface of the third auxiliary spacer element P3b partially abut the image side surface of the third spacer element P3 and the object side surface S7 of the fourth lens, respectively. The image side surface S8 of the fourth lens partially abuts the lens barrel P0.

[0135] As shown in Figure 21 , it is a structural schematic diagram of the optical imaging lens of Embodiment 4-2. In Embodiment 4-2, the abutting modes of the spacer elements are similar to those of Embodiment 4-1, and the relevant descriptions in Embodiment 4-1 can be referred to, which will not be repeated here.

[0136] In Embodiment Four, the first lens has a negative refractive power, the object side surface S1 of the first lens is a concave surface, and the image side surface S2 of the first lens is a concave surface. The second lens has a positive refractive power, the object side surface S3 of the second lens is a concave surface, and the image side surface S4 of the second lens is a convex surface. The third lens has a positive refractive power, the object side surface S5 of the third lens is a concave surface, and the image side surface S6 of the third lens is a convex surface. The fourth lens has a positive refractive power, the object side surface S7 of the fourth lens is a concave surface, and the image side surface S8 of the fourth lens is a convex surface.

[0137] Table 8 shows the basic structure parameters of the optical imaging lens of Example Four, wherein the units of the radius of curvature, thickness / distance are millimeter (mm).

[0138]

[0139]

[0140] Table 8

[0141] Table 9 shows the high order term coefficients of each aspherical surface that can be used in the optical imaging lens of Example Four, wherein each aspherical surface can be defined by the formula (1) given in Example One. In this example, the object side surface and the image side surface of the first lens to the fourth lens are aspherical surfaces.

[0142] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 A22 A24 A26 A28 S1 1.37E-01 -2.46E-02 5.51E-03 -1.41E-03 3.94E-04 -1.68E-04 4.78E-05 -1.36E-05 -4.56E-06 -5.05E-06 -4.00E-06 0.00E+00 0.00E+00 S2 1.11E-01 -1.75E-03 -4.12E-04 -5.80E-04 -4.44E-04 -2.03E-04 -1.57E-04 -2.77E-05 -3.20E-05 -1.70E-06 -1.17E-05 0.00E+00 0.00E+00 S3 5.12E-04 -1.92E-03 -5.78E-04 -1.92E-04 -1.05E-04 -3.30E-05 -2.13E-05 -6.93E-06 -5.44E-06 -1.56E-06 -2.86E-06 0.00E+00 0.00E+00 S4 2.57E-02 -6.56E-04 3.89E-04 1.40E-05 1.39E-05 5.70E-07 1.23E-06 3.01E-07 8.72E-07 -4.10E-07 2.11E-07 0.00E+00 0.00E+00 S5 1.79E-02 -2.56E-03 3.73E-04 -2.87E-05 7.67E-06 3.71E-06 -1.59E-06 1.50E-06 -1.23E-06 6.64E-07 -5.01E-07 0.00E+00 0.00E+00 S6 -1.35E-02 -1.51E-03 -1.43E-05 -1.02E-05 2.27E-05 1.47E-06 4.88E-06 -1.33E-06 6.56E-07 -8.76E-07 2.36E-07 0.00E+00 0.00E+00 S7 3.47E-02 -3.21E-03 -6.86E-04 2.32E-04 -2.65E-05 1.65E-05 -7.04E-06 -1.81E-06 -3.92E-06 5.14E-07 -1.84E-06 0.00E+00 0.00E+00 S8 5.48E-02 3.74E-04 -1.47E-03 3.42E-04 -4.27E-05 2.79E-05 -1.34E-05 -1.36E-05 -4.56E-06 -5.05E-06 -4.00E-06 0.00E+00 0.00E+00

[0143] Table 9

[0144] Figure 22 Figure 8 shows the axial chromatic aberration curve of the optical imaging lens of Example Four, which represents the deviation of the converging focal points of light rays of different wavelengths after passing through the optical imaging lens. Figure 23 Figure 9 shows the astigmatism curve of the optical imaging lens of Example Four, which represents the meridional image curvature and sagittal image curvature. Figure 24 Figure 10 shows the distortion curve of the optical imaging lens of Example Four, which represents the distortion size values corresponding to different field angles. Figure 25 Figure 11 shows the lateral chromatic aberration curve of the optical imaging lens of Example Four, which represents the deviation of the image height of light rays after passing through the lens.

[0145] According to Figures 22 to 25 It can be seen that the optical imaging lens given in Example Four can achieve good imaging quality.

[0146] In summary, the optical imaging lenses of Example One to Example Four respectively satisfy the relationships shown in Table 10.

[0147]

[0148]

[0149] Table 10

[0150] Table 11 shows the parameters (in mm) of each lens of the optical imaging lenses of Example One to Example Four.

[0151] Parameter / Embodiment 1-1 1-2 2-1 2-2 3-1 3-2 4-2 4-3 D1m 1.727 1.895 2.069 1.853 2.092 1.919 1.546 1.991 d2s 0.881 0.477 0.477 0.480 0.483 0.450 0.498 0.510 D2m 1.474 1.795 1.969 1.753 1.493 1.430 1.446 1.594 d3s 0.553 0.807 0.512 0.515 0.561 0.659 0.653 0.610 d0s 1.957 2.076 2.368 2.057 2.349 2.111 1.717 2.137 d0m 0.972 0.934 0.969 0.918 0.925 1.019 0.895 0.989 D0s 2.511 2.610 2.808 2.693 2.583 2.654 2.170 2.433 D0m 1.907 2.081 1.713 2.277 1.789 1.837 1.535 1.753 CP1 0.022 0.022 0.022 0.022 0.022 0.022 0.022 0.022 CP2 0.199 0.022 0.022 0.022 0.022 0.022 0.022 0.022 EP01 0.571 0.588 0.569 0.547 0.483 0.619 0.388 0.424 EP12 0.222 0.376 0.307 0.302 0.250 0.250 0.314 0.313 EP23 0.218 0.128 0.193 0.202 0.222 0.124 0.169 0.121 L 1.714 1.704 1.600 1.581 1.469 1.601 1.570 1.641 f1 -0.99 -0.99 -0.94 -0.94 -0.83 -0.83 -0.60 -0.60 f2 0.65 0.65 0.70 0.70 0.81 0.81 1.65 1.65 f3 4.50 4.50 1.96 1.96 1.27 1.27 0.78 0.78 f4 6.27 6.27 -30.54 -30.54 13.76 13.76 18.00 18.00

[0152] Table 11

[0153] The application also provides an imaging device, the electronic photosensitive element of which can be a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS). The imaging device can be a separate imaging device such as a digital camera, or an imaging module integrated on a mobile electronic device such as a mobile phone. The imaging device is equipped with the optical imaging lens described above.

[0154] Obviously, the above-described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the protection scope of the present application.

[0155] It should be noted that the terms used herein are only intended to describe specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, there is a feature, step, work, device, component and / or combination thereof.

[0156] It should be noted that the terms "first", "second", and the like used in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the application described herein can be implemented in an order other than those illustrated or described herein.

[0157] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. An optical imaging lens, characterized in that, The optical imaging lens can be used for near-infrared waveband imaging, and the optical imaging lens comprises a lens barrel, a lens group and a spacer element group assembled in the lens barrel, The lens group is composed of four lenses, and the lens group comprises a first lens, a second lens, a third lens and a fourth lens in sequence from the object side to the image side along the optical axis; The spacer element group comprises 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 is in contact with the image side surface of the first lens, and the second spacer element is located between the second lens and the third lens and is in contact with the image side surface of the second lens; The effective focal length f2 of the second lens, the central thickness CT2 of the second lens on the optical axis, the distance EP12 between the image side surface of the first spacer element and the object side surface of the second spacer element in the extension direction of the optical axis satisfy: 1.03≤f2 / (CT2+EP12)≤2.88; The curvature radius R3 of the object side surface of the second lens and the outer diameter D1m of the image side surface of the first spacer element satisfy: -1.93≤R3 / D1m≤-0.

41. 2.The optical imaging lens according to claim 1, wherein, The distance EP01 between the object side end surface of the lens barrel and the object side surface of the first spacer element in the extension direction of the optical axis and the effective focal length f1 of the first lens satisfy: -1.73≤f1 / EP01≤-1.

34. 3.The optical imaging lens according to claim 1, wherein, The air gap T12 of the first lens and the second lens on the optical axis, the central thickness CT1 of the first lens and the maximum thickness CP1 of the first spacer element satisfy: 0.71≤T12 / (CT1+CP1)≤3.

13. 4.The optical imaging lens according to claim 1, wherein, The curvature radius R4 of the image side surface of the second lens, the refractive index N2 of the second lens and the inner diameter d2s of the object side surface of the second spacer element satisfy: -2.63≤R4*N2 / d2s≤-0.

61.

5. The optical imaging lens according to claim 1, characterized in that, The outer diameter D2m of the image side surface of the second spacer element, the curvature radius R6 of the image side surface of the third lens and the refractive index N3 of the third lens satisfy: -2.62≤D2m / (R6*N3)≤-1.

28. 6.The optical imaging lens according to claim 1, wherein, The central thickness CT3 of the third lens, the air gap T23 of the second lens and the third lens on the optical axis and the maximum thickness CP2 of the second spacer element satisfy: 0.96≤CT3 / (T23+CP2)≤4.

33. 7.The optical imaging lens according to claim 1, wherein, The outer diameter D0s of the object side end surface of the lens barrel, the inner diameter d0s of the object side end surface of the lens barrel, the outer diameter D0m of the image side end surface of the lens barrel and the inner diameter d0m of the image side end surface of the lens barrel satisfy: 1.41≤(D0m-d0m) / (D0s-d0s)≤3.

70. 8.The optical imaging lens according to claim 1, wherein, The maximum height L of the lens barrel and the sum ∑CT of the central thicknesses of all lenses in the lens group satisfy: 1.64≤L / ∑CT≤2.

26. 9.The optical imaging lens according to claim 1, wherein, The curvature radius R1 of the object side surface of the first lens and the inner diameter d0s of the object side end surface of the lens barrel satisfy: -4.37≤R1 / d0s≤-0.

66.

10. The optical imaging lens according to any one of claims 1-9, wherein, The spacer element group further includes a third spacer element located between the third lens and the fourth lens and in contact with an image-side portion of the third lens, and between an effective focal length f3 of the third lens, an air interval T34 of the third lens and the fourth lens on the optical axis, a distance EP23 of an image-side surface of the second spacer element and an object-side surface of the third spacer element in the extension direction of the optical axis, the following is satisfied: 1.62 ≤ f3 / (EP23+T34) ≤ 14.

81.

11. The optical imaging lens according to any one of claims 1-9, wherein, The spacer element group further includes a third spacer element located between the third lens and the fourth lens and in contact with an image-side portion of the third lens, and between an inner diameter d3s of an object-side surface of the third spacer element and a curvature radius R7 of an object-side surface of the fourth lens, the following is satisfied: -2.05 ≤ R7 / d3s ≤ -0.

62.

12. The optical imaging lens according to any one of claims 1-9, wherein, The optical imaging lens satisfies at least one of the following, The first lens has negative refractive power; The second lens has positive refractive power; The third lens has positive refractive power.

13. The optical imaging lens according to any one of claims 1-9, wherein, The optical imaging lens satisfies at least one of the following, The object-side surface of the first lens is concave, and the image-side surface of the first lens is concave; The object-side surface of the second lens is concave, and the image-side surface of the second lens is convex; The object-side surface of the third lens is concave, and the image-side surface of the third lens is convex; The object-side surface of the fourth lens is concave, and the image-side surface of the fourth lens is convex.

Images