Optical lens

Abstract

The utility model provides an optical lens. The optical lens comprises a lens barrel, and a lens group and a spacing element group which are assembled in the lens barrel, wherein the lens group sequentially comprises a first lens to a fourth lens from an object side to an image side along an optical axis; the spacing element group at least comprises a third spacing element; the third spacing element is positioned between the third lens and the fourth lens and is in contact with the object side surface part of the fourth lens; the effective focal length f of the optical lens, the effective focal length f3 of the third lens and the effective focal length f4 of the fourth lens meet the condition of 0.40 lt; f3 / f + f4 / f < = 0.75; the combined focal length f34 of the third lens and the fourth lens, the inner diameter d0m of the end face, closest to the image side, of the lens barrel and the inner diameter d3m of the image side face of the third spacing element meet the following formula:-0.05 lt; (d0m-d3m) / f < 34lt >; and 0.05%. According to the utility model, the problem of serious stray light caused by the fact that an optical lens in the prior art meets the long-focus requirement is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of optical imaging devices, and more particularly to an optical lens. Background Art

[0002] With the development of electronic products, the imaging system plays a crucial role in electronic products. Users have an increasing demand for the camera function of electronic products and require that electronic devices can meet diverse photography needs. Most products from mainstream mid-range to top flagship models of various brands have main camera lenses and wide-angle lenses, but telephoto lenses have become exclusive to high-end flagship models. With the higher requirements for the practical application of the imaging system in smartphones, there is a trend of full-scale popularization of telephoto lenses in the configuration of smartphones. However, in existing telephoto lenses, light is prone to large deflection at the end of the lens barrel, resulting in light being directed towards the end of the lens barrel, generating reflected stray light and affecting the imaging performance of the optical lens.

[0003] That is to say, the existing optical lens has the problem that meeting the telephoto requirement leads to serious stray light. Summary of the Utility Model

[0004] The main object of the present utility model is to provide an optical lens to solve the problem in the prior art that the existing optical lens has serious stray light when meeting the telephoto requirement.

[0005] To achieve the above object, according to one aspect of the present utility model, there is provided an optical lens, including a lens barrel, a lens group and a spacer element group assembled in the lens barrel. The lens group includes, in order from the object side to the image side along the optical axis, a first lens, a second lens, a third lens with a negative optical power, and a fourth lens with a positive optical power; the spacer element group includes at least a third spacer element, the third spacer element is located between the third lens and the fourth lens and partially contacts the object side surface of the fourth lens; the following relationships are satisfied among the effective focal length f of the optical lens, the effective focal length f3 of the third lens, and the effective focal length f4 of the fourth lens: 0.40 < f3 / f + f4 / f ≤ 0.75; the following relationship is satisfied between the combined focal length f34 of the third lens and the fourth lens, the inner diameter d0m of the end face of the lens barrel closest to the image side, and the inner diameter d3m of the image side surface of the third spacer element: -0.05 < (d0m - d3m) / f34 < 0.05.

[0006] According to another aspect of the present utility model, an optical lens is provided. The optical lens includes a lens barrel, a lens group, and a spacer element group assembled within the lens barrel. The lens group sequentially includes a first lens, a second lens, a third lens with a negative focal power, and a fourth lens with a positive focal power along the optical axis from the object side to the image side. 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 lens and the third lens and partially contacts the object side surface of the third lens. The third spacer element is located between the third lens and the fourth lens and partially contacts the object side surface of the fourth lens. The following relationships are satisfied among the effective focal length f of the optical lens, the effective focal length f3 of the third lens, and the effective focal length f4 of the fourth lens: 0.40 < f3 / f + f4 / f ≤ 0.75; the following relationships are satisfied among the inner diameter d2m of the image side surface of the second spacer element, the inner diameter d3m of the image side surface of the third spacer element, the curvature radius R5 of the object side surface of the third lens, and the curvature radius R7 of the object side surface of the fourth lens: 0.55 < d2m / R5 + d3m / R7 < 0.85.

[0007] According to another aspect of the present utility model, an optical lens is provided. The optical lens includes a lens barrel, a lens group, and a spacer element group assembled within the lens barrel. The lens group sequentially includes a first lens, a second lens, a third lens with a negative focal power, and a fourth lens with a positive focal power along the optical axis from the object side to the image side. 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 lens and the third lens and partially contacts the object side surface of the third lens. The third spacer element is located between the third lens and the fourth lens and partially contacts the object side surface of the fourth lens. The following relationships are satisfied among the inner diameter d0s of the end face of the lens barrel closest to the object side, the inner diameter d0m of the end face of the lens barrel closest to the image side, and the effective focal length f of the optical lens: 0.15 < (d0s - d0m) / f ≤ 0.25. The following relationships are satisfied among the curvature radius R4 of the image side surface of the second lens, the inner diameter d2s of the object side surface of the second spacer element, the curvature radius R6 of the image side surface of the third lens, and the inner diameter d3s of the object side surface of the third spacer element: 2.25 < R4 / d2s + R6 / d3s < 3.95.

[0008] Further, the following relationship is satisfied among the height L of the lens barrel, the central thickness CT3 of the third lens, the air gap T34 between the third lens and the fourth lens on the optical axis, and the central thickness CT4 of the fourth lens: 2.20 ≤ L / (CT3 + T34 + CT4) < 2.65.

[0009] Further, the following relationship is satisfied among the curvature radius R8 of the image side surface of the fourth lens, the outer diameter D0m of the end face of the lens barrel closest to the image side, and the inner diameter d0m of the end face of the lens barrel closest to the image side: -2.60 < R8 / (D0m - d0m) < -1.85.

[0010] Furthermore, the radius of curvature R7 of the object side of the fourth lens, the radius of curvature R8 of the image side of the fourth lens, and the inner diameter d0s of the end face of the lens barrel closest to the object side satisfy the following condition: -6.90 < (R7 + R8) / d0s < 2.55.

[0011] Furthermore, the maximum thickness CP3 of the third spacer element along the optical axis and the air gap T34 between the third and fourth lenses on the optical axis satisfy the following: 0 <CP3 / T34<0.25。

[0012] Furthermore, the outer diameter D0m of the end face closest to the image side of the lens barrel, the maximum effective radius DT42 of the image side of the fourth lens, and the center thickness CT4 of the fourth lens satisfy the following condition: 9.85 < (D0m - DT42) / CT4 ≤ 11.

[0013] Furthermore, the lens barrel has a bearing surface, which abuts against the lens closest to the image side of the lens group or the spacer closest to the image side of the spacer group. The maximum distance Y between the end face of the lens barrel closest to the image side and the bearing surface along the optical axis satisfies: 0.25 <Y<0.55。

[0014] Furthermore, the inner diameter d0s of the end face of the lens barrel closest to the object side, the inner diameter d0m of the end face of the lens barrel closest to the image side, and the effective focal length f of the optical lens satisfy the following condition: 0.15 < (d0s - d0m) / f ≤ 0.25.

[0015] Furthermore, the radius of curvature R5 of the object side of the third lens, the radius of curvature R6 of the image side of the third lens, and the inner diameter d3s of the object side of the third spacer element satisfy the following condition: 1.95 < (R5 + R6) / d3s ≤ 2.60.

[0016] Furthermore, the spacer group includes at least a second spacer element, which is located between the second lens and the third lens and contacts the object-side portion of the third lens;

[0017] The air gap T34 between the third and fourth lenses on the optical axis and the center thickness CT3 of the third lens satisfy the following condition: 1.00 <T34 / CT3<2.05;

[0018] The center thickness CT3 of the third lens and the distance EP23 between the image-side surface of the second spacer element and the object-side surface of the third spacer element along the optical axis extension direction satisfy: 2.50 <EP23 / CT3≤3.30。

[0019] Furthermore, the spacer element group at least includes a second spacer element, which is located between the second lens and the third lens and partially contacts the object side surface of the third lens; the following relationship is satisfied among the maximum effective radius DT31 of the object side surface of the third lens, the maximum effective radius DT32 of the image side surface of the third lens, and the spacing EP23 between the image side surface of the second spacer element and the object side surface of the third spacer element in the optical axis extension direction: 0.20 < (DT31 - DT32) / EP23 < 0.35.

[0020] Furthermore, the spacer element group at least includes a second spacer element, which is located between the second lens and the third lens and partially contacts the object side surface of the third lens; the following relationship is satisfied among the effective focal length f3 of the third lens and the spacing EP23 between the image side surface of the second spacer element and the object side surface of the third spacer element in the optical axis extension direction: -5.40 < f3 / EP23 < -3.25.

[0021] Furthermore, the spacer element group at least includes a second spacer element, which is located between the second lens and the third lens and partially contacts the object side surface of the third lens; the following relationship is satisfied among the inner diameter d2m of the image side surface of the second spacer element, the inner diameter d3m of the image side surface of the third spacer element, the curvature radius R5 of the object side surface of the third lens, and the curvature radius R7 of the object side surface of the fourth lens: 0.55 < d2m / R5 + d3m / R7 < 0.85.

[0022] Furthermore, the spacer element group at least includes a second spacer element, which is located between the second lens and the third lens and partially contacts the object side surface of the third lens; the following relationship is satisfied between the inner diameter d3s of the object side surface of the third spacer element and the inner diameter d2s of the object side surface of the second spacer element: 0.85 < d3s / d2s ≤ 0.95.

[0023] Applying the technical solution of the present utility model, an optical lens includes a lens barrel, a lens group, and a spacer element group assembled in the lens barrel. The lens group sequentially includes a first lens, a second lens, a third lens with a negative optical power, and a fourth lens with a positive optical power along the optical axis from the object side to the image side. The spacer element group at least includes a third spacer element, which is located between the third lens and the fourth lens and partially contacts the object side surface of the fourth lens. The following relationships are satisfied among the effective focal length f of the optical lens, the effective focal length f3 of the third lens, and the effective focal length f4 of the fourth lens: 0.40 < f3 / f + f4 / f ≤ 0.75. The following relationship is satisfied between the combined focal length f34 of the third lens and the fourth lens and the inner diameter d0m of the end face of the lens barrel closest to the image side and the inner diameter d3m of the image side surface of the third spacer element: -0.05 < (d0m - d3m) / f34 < 0.05.

[0024] The optical lens of the present application consists of a lens barrel, four lenses, and at least one spacer element. When the effective focal length f of the optical lens, the effective focal length f3 of the third lens, and the effective focal length f4 of the fourth lens satisfy 0.40 < f3 / f + f4 / f ≤ 0.75, by optimizing the focal lengths of the third lens, the fourth lens, and the effective focal length of the optical lens, the degree of refraction of light is controlled, so that the optical lens has the characteristics of a long focal length. Since the third lens and the fourth lens are located at the end of the optical lens and are the last two lenses that the light passes through when leaving the optical system, the light is easily deflected to the end of the lens barrel to form reflected stray light, resulting in serious stray light.

[0025] In order to reduce the stray light generated at the end of the lens barrel of the optical lens, the present application constrains (d0m - d3m) / f34 within a reasonable range to control the apertures of the third lens and the fourth lens, reduce the light deflected at large angles, and thus reduce the light incident on the inner wall of the lens barrel, minimizing the generation of stray light at the end of the lens barrel, while ensuring that the inner diameter d0m of the end face of the lens barrel closest to the image side is within a reasonable range to ensure the imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings forming a part of this application are used to provide a further understanding of the present utility model. The schematic embodiments and descriptions thereof are used to explain the present utility model and do not constitute an improper limitation to the present utility model. In the drawings:

[0027] Figure 1 It shows the dimension marking diagram of the optical lens of an optional embodiment of the present utility model;

[0028] Figure 2 It shows the structural schematic diagram of the optical lens of Embodiment 1-1 of the present utility model;

[0029] Figure 3 It shows the structural schematic diagram of the optical lens of Embodiment 1-2 of the present utility model;

[0030] Figure 4 It shows the structural schematic diagram of the optical lens of Embodiment 1-3 of the present utility model;

[0031] Figures 5 to 7 It respectively shows the axial chromatic aberration, astigmatism curve, and distortion curve of the optical lens of Embodiment 2 of the present utility model;

[0032] Figure 8 It shows the structural schematic diagram of the optical lens of Embodiment 2-1 of the present utility model;

[0033] Figure 9 It shows the structural schematic diagram of the optical lens of Embodiment 2-2 of the present utility model;

[0034] Figure 10 A schematic diagram of the optical lens structure of embodiments 2-3 of this utility model is shown;

[0035] Figures 11 to 13 The on-axis chromatic aberration, astigmatism curves, and distortion curves of the optical lens of Embodiment 2 of this utility model are shown respectively.

[0036] Figure 14 A schematic diagram of the structure of the optical lens of Embodiment 3-1 of this utility model is shown;

[0037] Figure 15 A schematic diagram of the optical lens structure of Embodiment 3-2 of this utility model is shown;

[0038] Figure 16 A schematic diagram of the optical lens of Embodiment 3-3 of this utility model is shown;

[0039] Figures 17 to 19 The on-axis chromatic aberration, astigmatism curves, and distortion curves of the optical lens of Embodiment 3 of this utility model are shown respectively.

[0040] Figure 20 A stray light spot diagram of an optical lens according to an optional embodiment of the present invention is shown;

[0041] Figure 21 A stray light path diagram of an example optical lens is shown;

[0042] Figure 22 It shows Figure 21 A stray light pattern of the optical lens in the image;

[0043] Figure 23 Another example of a stray light path diagram for an optical lens is shown;

[0044] Figure 24 It shows Figure 23 A stray light pattern of the optical lens in the image. Detailed Implementation

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] In order to solve the problem of severe stray light caused by optical lenses in the prior art when meeting telephoto requirements, this utility model provides an optical lens.

[0052] like Figures 1 to 19As shown, the optical lens includes a lens barrel, a lens group and a spacer element group assembled in the lens barrel. The lens group includes, in order from the object side to the image side along the optical axis, a first lens, a second lens, a third lens with negative optical power, and a fourth lens with positive optical power; the spacer element group includes at least a third spacer element, and the third spacer element is located between the third lens and the fourth lens and is in partial contact with the object side surface of the fourth lens; the effective focal length f of the optical lens, the effective focal length f3 of the third lens, and the effective focal length f4 of the fourth lens satisfy: 0.40 < f3 / f + f4 / f ≤ 0.75; the combined focal length f34 of the third lens and the fourth lens, the inner diameter d0m of the end face of the lens barrel closest to the image side, and the inner diameter d3m of the image side surface of the third spacer element satisfy: -0.05 < (d0m - d3m) / f34 < 0.05.

[0053] The optical lens of the present application is composed of a lens barrel, four lenses and at least one spacer element. When 0.40 < f3 / f + f4 / f ≤ 0.75 is satisfied among the effective focal length f of the optical lens, the effective focal length f3 of the third lens, and the effective focal length f4 of the fourth lens, by optimizing the focal length of the third lens, the focal length of the fourth lens, and the effective focal length of the optical lens, the degree of refraction of light is controlled, so that the optical lens has the characteristics of a long focal length. Since the third lens and the fourth lens are located at the end of the optical lens and are the last two lenses that the light passes through when leaving the optical system, the light is prone to deflect to the end of the lens barrel to form reflected stray light, resulting in serious stray light.

[0054] In order to reduce the stray light generated at the end of the lens barrel of the optical lens, the present application confines (d0m - d3m) / f34 within a reasonable range to control the apertures of the third lens and the fourth lens, reduce the light deflected at large angles, and further reduce the light hitting the inner wall of the lens barrel, minimizing the generation of stray light at the end of the lens barrel, while ensuring that the inner diameter d0m of the end face of the lens barrel closest to the image side is within a reasonable range to ensure the imaging quality.

[0055] Table 1 below gives a comparison of the stray light results between an optional embodiment of the present application and an optical lens in the prior art.

[0056]

[0057]

[0058] Table 1

[0059] In addition, referring to Table 1 and Figures 20 to 24 as shown, Figure 20 shows an optical stray light spot diagram when f3 / f + f4 / f = 0.53 and (d0m - d3m) / f34 = -0.04. From Figure 20As can be seen, there is no obvious stray light. Lenses 1 and 3 in Table 1 are optical lenses in the prior art. Figure 21 and Figure 22 respectively show the stray light optical path diagram and the stray light spot diagram that satisfy f3 / f + f4 / f = 0.53 and (d0m - d3m) / f34 = -0.13. Figure 23 and Figure 24 respectively show the stray light optical path diagram and the stray light spot diagram that satisfy f3 / f + f4 / f = 0.53 and (d0m - d3m) / f34 = 0.12.

[0060] From Figures 20 to 24 it can be seen that when (d0m - d3m) / f34 = -0.04 is satisfied, the stray light energy weakens, the stray light is improved, and the performance is better. When (d0m - d3m) / f34 = -0.13 is satisfied, the stray light energy is stronger, the stray light has a greater impact on the imaging quality, and the performance is worse. When (d0m - d3m) / f34 = 0.12 is satisfied, the stray light energy is stronger, the stray light has a greater impact on the imaging quality, and the performance is worse. Thus, it can be seen that when (d0m - d3m) / f34 is within the range of -0.1 to 0.1, the improvement effect of the stray light of the optical lens is the best. Therefore, in this application, by restricting -0.05 < (d0m - d3m) / f34 < 0.05, the apertures of the third lens and the fourth lens are reasonably restricted to reduce the light rays with large-angle deflection, and further reduce the light rays hitting the inner wall of the lens barrel, so as to minimize the generation of stray light at the end of the lens barrel.

[0061] It should be noted that in this application, (d0m - d3m) / f34 is restricted within a reasonable range to control the apertures of the third lens and the fourth lens, and further to control and reduce the light rays with large-angle deflection, so as to solve the stray light problem brought about when f3 / f + f4 / f is within the range of 0.40 to 0.75. It is particularly applicable to the design of telephoto lenses. When (d0m - d3m) / f34 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 the surface shape of the lens are further optimizations of the optical lens on this basis. Each lens can be positive or negative according to the design requirements of the actual optical system, and the surface shape of each lens can also be convex or concave according to the design requirements of the optical system, as long as the optical system satisfies: 0.40 < f3 / f + f4 / f ≤ 0.75; -0.05 < (d0m - d3m) / f34 < 0.05, the stray light can be reduced while meeting the telephoto requirements.

[0062] For example, the first lens has a positive optical power, the second lens has a positive optical power, the third lens has a negative optical power, and the fourth lens has a positive optical power. Another example is that the object side surface of the first lens is convex, the object side surface of the second lens is convex, the image side surface of the second lens is concave, the object side surface of the third lens is convex, the image side surface of the third lens is concave, and the image side surface of the fourth lens is convex. The stray light simulation of the optical lens can be performed by software and / or tools such as LIGHTOOS, ASAP, etc. The optical lens in this application uses ASAP for simulation. During the simulation using software and / or tools such as the above, the surface profiles of each lens can be simulated according to the built-in surface profiles of the software and / or tools used and adjusted appropriately.

[0063] In some alternative embodiments, the height L of the lens barrel, the central thickness CT3 of the third lens, the air gap T34 between the third lens and the fourth lens on the optical axis, and the central thickness CT4 of the fourth lens satisfy: 2.20 ≤ L / (CT3 + T34 + CT4) < 2.65. By controlling L / (CT3 + T34 + CT4) within a reasonable range, the central thicknesses of the third lens and the fourth lens and the interval therebetween can be reasonably allocated, thereby optimizing the path of light passing through the entire optical system, reducing aberration, improving imaging quality, and at the same time being beneficial to improving assembly stability and reducing performance fluctuations caused by external environmental differences. By restricting the central thicknesses of the third lens and the fourth lens and the interval therebetween, it is not only beneficial to a compact structure but also beneficial to the smooth transition of light between the third lens and the fourth lens, reducing light loss while meeting the long focal length performance and reducing the generation of stray light.

[0064] In some alternative embodiments, the radius of curvature R8 of the image side surface of the fourth lens, the outer diameter D0m of the end face of the lens barrel closest to the image side, and the inner diameter d0m of the end face of the lens barrel closest to the image side satisfy: -2.60 < R8 / (D0m - d0m) < -1.85. By restricting R8 / (D0m - d0m) within a reasonable range, it is beneficial to control the exit angle of light from the image side surface of the fourth lens, reducing the reflection of light to the end face of the lens barrel closest to the image side before reaching the imaging surface after exiting the fourth lens, further reducing the stray light generated at the end face of the lens barrel closest to the image side, further reducing the generation of stray light, and improving imaging quality.

[0065] It should be noted that after the light exits the fourth lens and before reaching the imaging surface, it may be reflected by some structures in the electronic device to the end face of the lens barrel closest to the image side.

[0066] In some optional embodiments, the radius of curvature R7 of the object side surface of the fourth lens, the radius of curvature R8 of the image side surface of the fourth lens, and the inner diameter d0s of the end face of the lens barrel closest to the object side satisfy: -6.90 < (R7 + R8) / d0s < 2.55. By limiting (R7 + R8) / d0s within a reasonable range, while ensuring the light incident amount of the optical lens, the deflection angle of light within the fourth lens can also be ensured, so as to meet the performance requirements of long-distance telephoto imaging, reduce light loss, and thus improve the imaging quality.

[0067] In some optional embodiments, the maximum thickness CP3 of the third spacer element in the extending direction along the optical axis and the air gap T34 between the third lens and the fourth lens on the optical axis satisfy: 0 < CP3 / T34 < 0.25. By limiting CP3 / T34 within a reasonable range, it is beneficial to the spatial control of the performance requirements of the air gap from the third lens to the fourth lens and its spacer element. The spacer element within a reasonable thickness range not only meets the requirement of blocking marginal light but also ensures the stability requirement of the assembled structure. The appropriate air gap between the third lens and the fourth lens on the optical axis reserves sufficient space for the transition of light refraction change, meeting the actual requirements of telephoto imaging.

[0068] In some optional embodiments, the outer diameter D0m of the end face of the lens barrel closest to the image side, the maximum effective radius DT42 of the image side surface of the fourth lens, and the central thickness CT4 of the fourth lens satisfy: 9.85 < (D0m - DT42) / CT4 ≤ 11. By limiting (D0m - DT42) / CT4 within a reasonable range, it can ensure that the light penetrates through the fourth lens and reaches the imaging surface at an appropriate angle and light density, ensuring the imaging quality and the performance requirements of the telephoto lens.

[0069] In some optional embodiments, the lens barrel has a bearing surface that bears against the lens closest to the image side of the lens group or the spacer element closest to the image side of the spacer element group. The maximum distance Y in the extending direction along the optical axis between the end face of the lens barrel closest to the image side and the bearing surface satisfies: 0.25 < Y < 0.55. If the maximum distance Y in the extending direction along the optical axis between the end face of the lens barrel closest to the image side and the bearing surface is less than 0.25 mm, it will lead to poor structural strength at the rear end of the lens barrel, which is not conducive to bearing against the fourth lens and is prone to the risk of deformation. If the maximum distance Y in the extending direction along the optical axis between the end face of the lens barrel closest to the image side and the bearing surface is greater than 0.55 mm, stray light is likely to be generated on the inner wall surface between the bearing surface and the end face of the lens barrel closest to the image side, and it also increases the weight of the optical lens, reducing the design freedom of the optical lens. Limiting the maximum distance Y in the extending direction along the optical axis between the end face of the lens barrel closest to the image side and the bearing surface within the range of 0.25 to 0.55 mm can reduce the risk of stray light while ensuring the structural strength at the rear end of the lens barrel, and is also beneficial to the lightweight of the optical lens.

[0070] In some optional embodiments, the inner diameter d0s of the end face of the lens barrel closest to the object side, the inner diameter d0m of the end face of the lens barrel closest to the image side, and the effective focal length f of the optical lens satisfy: 0.15 < (d0s - d0m) / f ≤ 0.25. By restricting (d0s - d0m) / f within a reasonable range, while ensuring the light flux, it is beneficial to reduce the field angle of the optical lens, which is conducive to the optical lens being able to capture distant scenes more clearly and achieving long focal length performance.

[0071] In some optional embodiments, the radius of curvature R5 of the object side surface of the third lens, the radius of curvature R6 of the image side surface of the third lens, and the inner diameter d3s of the object side surface of the third spacer element satisfy: 1.95 < (R5 + R6) / d3s ≤ 2.60. By controlling (R5 + R6) / d3s within a reasonable range, it is beneficial to control the degree of deflection of light when entering the third lens and the degree of deflection of light when exiting the third lens, so as to ensure that light enters the fourth lens within the range of the inner diameter d3s of the object side surface of the third spacer element, which is conducive to reducing the stray light of light.

[0072] In some optional embodiments, the spacer element group at least includes a second spacer element, the second spacer element is located between the second lens and the third lens and is in partial contact with the object side surface of the third lens; the air gap T34 between the third lens and the fourth lens on the optical axis and the central thickness CT3 of the third lens satisfy: 1.00 < T34 / CT3 < 2.05; the central thickness CT3 of the third lens, the interval EP23 between the image side surface of the second spacer element and the object side surface of the third spacer element in the extending direction of the optical axis satisfy: 2.50 < EP23 / CT3 ≤ 3.30. By controlling the air gap T34 between the third lens and the fourth lens on the optical axis, the central thickness CT3 of the third lens, and the interval EP23 between the image side surface of the second spacer element and the object side surface of the third spacer element in the extending direction of the optical axis within a reasonable range, while the light is smoothly transitioning between the third lens and the fourth lens, it is beneficial to control the thickness ratio of the third lens, avoid the appearance defects and abnormal stray light generated during the actual processing, and further improve the overall imaging quality of the optical lens.

[0073] In some optional embodiments, the spacer element group at least includes a second spacer element, the second spacer element is located between the second lens and the third lens and is in partial contact with the object side surface of the third lens; the maximum effective radius DT31 of the object side surface of the third lens, the maximum effective radius DT32 of the image side surface of the third lens, and the spacing EP23 between the image side surface of the second spacer element and the object side surface of the third spacer element in the optical axis extension direction satisfy: 0.20 < (DT31 - DT32) / EP23 < 0.35. By controlling (DT31 - DT32) / EP23 within a reasonable range, the shape and edge thickness of the third lens can be effectively controlled, which is beneficial to the processing and molding of the third lens. At the same time, by controlling the maximum effective radii of the object side surface and the image side surface of the third lens, the optical performance of the optical lens can also be taken into account, which is beneficial to reducing optical distortion and the thickness sensitivity of the lens, and further achieving the purpose of correcting field curvature.

[0074] In some optional embodiments, the spacer element group at least includes a second spacer element, the second spacer element is located between the second lens and the third lens and is in partial contact with the object side surface of the third lens; the effective focal length f3 of the third lens and the spacing EP23 between the image side surface of the second spacer element and the object side surface of the third spacer element in the optical axis extension direction satisfy: -5.40 < f3 / EP23 < -3.25. By controlling f3 / EP23 within a reasonable range, it helps to reduce imaging quality problems such as aberration and distortion caused by improper spacing between elements near the third lens and mismatch with the focal length of the third lens. At the same time, it can ensure that light can pass through the optical lens in the expected manner and form a clear and accurate image on the imaging surface.

[0075] In some optional embodiments, the inner diameter d2m of the image side surface of the second spacer element, the inner diameter d3m of the image side surface of the third spacer element, the curvature radius R5 of the object side surface of the third lens, and the curvature radius R7 of the object side surface of the fourth lens satisfy: 0.55 < d2m / R5 + d3m / R7 < 0.85. By controlling d2m / R5 + d3m / R7 within a reasonable range, it is beneficial for light to smoothly enter the object side surface of the third lens and the object side surface of the fourth lens, thereby reducing light loss and improving imaging quality. At the same time, it is beneficial to reasonably control the propagation path and light distribution of light between the third lens and the fourth lens to meet the performance requirements of telephoto imaging.

[0076] In some alternative embodiments, the spacer element group at least includes a second spacer element, the second spacer element is located between the second lens and the third lens and is in partial contact with the object side surface of the third lens; the inner diameter d3s of the object side surface of the third spacer element and the inner diameter d2s of the object side surface of the second spacer element satisfy: 0.85 < d3s / d2s ≤ 0.95. By controlling d3s / d2s within a reasonable range, it is ensured that marginal rays pass through the third lens and the third spacer element at an appropriate angle, so as to ensure that the marginal rays participate in imaging, which is conducive to improving the imaging quality of the optical lens.

[0077] In addition, in another alternative embodiment of the present application, an optical lens is further provided. The optical lens includes a lens barrel and a lens group and a spacer element group assembled in the lens barrel. The lens group sequentially includes a first lens with a positive optical power, a second lens with a positive optical power, a third lens with a negative optical power, and a fourth lens with a positive optical power along the optical axis from the object side to the image side. The object side surface of the first lens is convex, the object side surface of the second lens is convex, the image side surface of the second lens is concave, the object side surface of the third lens is convex, the image side surface of the third lens is concave, and the image side surface of the fourth lens is convex; the spacer element group at least includes 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 partial contact with the object side surface of the third lens. The third spacer element is located between the third lens and the fourth lens and is in partial contact with the object side surface of the fourth lens; the effective focal length f of the optical lens, the effective focal length f3 of the third lens, and the effective focal length f4 of the fourth lens satisfy: 0.40 < f3 / f + f4 / f ≤ 0.75; the inner diameter d2m of the image side surface of the second spacer element, the inner diameter d3m of the image side surface of the third spacer element, the curvature radius R5 of the object side surface of the third lens, and the curvature radius R7 of the object side surface of the fourth lens satisfy: 0.55 < d2m / R5 + d3m / R7 < 0.85.

[0078] The optical lens of the present application consists of a lens barrel, four lenses and at least one spacer element. When the effective focal length f of the optical lens, the effective focal length f3 of the third lens, and the effective focal length f4 of the fourth lens satisfy 0.40 < f3 / f + f4 / f ≤ 0.75, by optimizing the focal length of the third lens, the focal length of the fourth lens, and the effective focal length of the optical lens, the optical lens has the characteristics of a long focal length. Since the third lens and the fourth lens are located at the end of the optical lens and are the last two lenses that the light passes through when leaving the optical system, the light is easily deflected to the end of the lens barrel to form reflected stray light, resulting in serious stray light. To reduce the stray light generated at the end of the lens barrel of the optical lens, the present application constrains d2m / R5 + d3m / R7 within a reasonable range to control the deflection angle of the light when entering the object side surfaces of the third lens and the fourth lens, reduce the deflection of large-angle light, ensure that the light passes through the second spacer element and the third spacer element smoothly, reduce the reflected stray light generated at the spacer element and the inner wall of the lens barrel, and improve the imaging quality. At the same time, it is beneficial to reasonably control the propagation path and light distribution of the light between the third lens and the fourth lens to meet the performance requirements of long focal length imaging.

[0079] In addition, in another optional embodiment of the present application, an optical lens is further provided. The optical lens includes a lens barrel, a lens group and a spacer element group assembled in the lens barrel. The lens group includes a first lens with a positive optical power, a second lens with a positive optical power, a third lens with a negative optical power, and a fourth lens with a positive optical power in sequence along the optical axis from the object side to the image side. The object side surface of the first lens is convex, the object side surface of the second lens is convex, the image side surface of the second lens is concave, the object side surface of the third lens is convex, the image side surface of the third lens is concave, and the image side surface of the fourth lens is convex; 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 lens and the third lens and is in partial contact with the object side surface of the third lens. The third spacer element is located between the third lens and the fourth lens and is in partial contact with the object side surface of the fourth lens; the inner diameter d0s of the end surface of the lens barrel closest to the object side, the inner diameter d0m of the end surface of the lens barrel closest to the image side, and the effective focal length f of the optical lens satisfy: 0.15 < (d0s - d0m) / f ≤ 0.25. The radius of curvature R4 of the image side surface of the second lens, the inner diameter d2s of the object side surface of the second spacer element, the radius of curvature R6 of the image side surface of the third lens, and the inner diameter d3s of the object side surface of the third spacer element satisfy: 2.25 < R4 / d2s + R6 / d3s < 3.95.

[0080] The optical lens of this application consists of a lens barrel, four lenses, and at least one spacer element. The inner diameter d0s of the end face of the lens barrel closest to the object side, the inner diameter d0m of the end face of the lens barrel closest to the image side, and the effective focal length f of the optical lens satisfy the following condition: 0.15 < (d0s - d0m) / f ≤ 0.25. This ensures sufficient light throughput while reducing the field of view of the optical lens, allowing it to capture distant scenes more clearly and achieve telephoto performance. However, because the value of d0s - d0m is relatively large, it easily leads to large-angle deflection of light within the lens group, causing multiple reflections and resulting in severe stray light. To reduce stray light generated within the lens group, this application constrains R4 / d2s + R6 / d3s within a reasonable range to control the deflection angle of light at the intermediate lens. This facilitates a smooth transition of light between the second and third lenses, reduces large-angle deflection at the intermediate lens position, decreases multiple reflections of stray light at the inner wall of the lens barrel, and improves image quality.

[0081] Of course, this embodiment may also include other parametric expressions as described in the above embodiments, which will not be elaborated here.

[0082] Optionally, the aforementioned optical lens may also include protective glass for protecting the photosensitive element located on the imaging plane.

[0083] 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.

[0084] 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.

[0085] Figure 1 A schematic diagram showing the dimensions of an optical lens according to this application is provided. Figure 1 The parameters d2s, d2m, d3s, d3m, d0s, d0m, D0m, CP3, EP23, L, and Y are clearly and intuitively indicated to provide a clear 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 drawings when describing specific embodiments.

[0086] 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.

[0087] 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 2-3. In the three examples within the same embodiment, the radii of curvature, center thickness, and other parameters of the optical lenses from the first to the fourth lens, as well as the spacing distance between the lenses and the higher-order coefficients, 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.

[0088] It should be noted that any one of the examples in Embodiments 1 to 3 described below is applicable to all embodiments of this application.

[0089] Example 1

[0090] like Figures 2 to 7 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.

[0091] like Figures 2 to 4 As shown, the optical 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 first auxiliary spacer element P1b, 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.

[0092] like Figure 2The diagram shows a schematic of the optical lens structure of Embodiment 1-1. In this example, 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 of the first spacer element P1 partially 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 partially abut against the image-side surface of the first spacer element P1 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 S6 of the third lens abuts against the bearing surface of the lens barrel P0.

[0093] like Figure 3 The diagram shows a schematic representation of the optical lens in Embodiments 1-2. In Embodiments 1-2, the optical lens further includes a second auxiliary spacer element P1c. The object-side and image-side surfaces of the second auxiliary spacer element P1c abut against the image-side surface of the first auxiliary spacer element P1b and the object-side surface S3 portion of the second lens, respectively. The abutment and contact methods of the other spacer elements are similar to those in Embodiment 1-1, and can be found in the relevant descriptions in Embodiment 1-1; they will not be repeated here.

[0094] like Figure 4 The diagram shown is a structural schematic of the optical lens in Embodiments 1-3. In Embodiments 1-3, the abutment and contact method of each spacer element is similar to that in Embodiment 1-1, and can be referred to the relevant description in Embodiment 1-1, which will not be repeated here.

[0095] 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 2. (Unit: mm)

[0096] Parameters / Examples 1-1 1-2 1-3 d2s 5.14 5.06 5.12 d2m 5.10 5.02 5.08 d3s 4.43 4.50 4.60 d3m 4.39 4.46 4.56 d0s 7.98 8.20 7.85 d0m 4.78 4.54 4.38 D0m 8.84 8.64 8.44 EP23 1.31 1.19 1.17 CP3 0.01 0.01 0.06 L 4.17 4.07 4.22 Y 0.40 0.28 0.45

[0097] Table 2

[0098] In Embodiment 1, the first lens has positive optical power, and its object-side surface S1 and image-side surface S2 are both convex. The second lens has positive optical power, its object-side surface S3 is convex, and its image-side surface S4 is concave. The third lens has negative optical power, its object-side surface S5 is convex, and its image-side surface S6 is concave. The fourth lens has positive optical power, its object-side surface S7 is convex, and its image-side surface S8 is convex.

[0099] Table 3 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).

[0100]

[0101] Table 3

[0102] In Embodiment 1, the object-side surface and image-side surface of the second lens E2 to the fourth lens E4 are both aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0103]

[0104] 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 4 below gives the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 that can be used for each aspherical mirror S3-S8 in Example 1.

[0105]

[0106]

[0107] Table 4

[0108] 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.

[0109] according to Figures 5 to 7 As can be seen, the optical lens given in Example 1 can achieve good imaging quality.

[0110] Example 2

[0111] like Figures 8 to 13 As shown, the optical lens of Embodiment 2 is described. Figure 8 A schematic diagram of the optical lens of Embodiment 2-1 is shown. Figure 9 A schematic diagram of the optical lens of Embodiment 2-2 is shown. Figure 10 A schematic diagram of the optical lens of Embodiments 2-3 is shown.

[0112] like Figures 8 to 10As shown, the optical lens includes a lens barrel P0, four lenses and multiple spacer elements. The lens barrel P0 includes a first lens E1, a second auxiliary spacer element P1c, a first spacer element P1, a first auxiliary spacer element P1b, 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.

[0113] like Figure 8 The diagram shows a schematic of the optical lens structure of Embodiment 2-1. In this example, 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 abut against the image-side surface S2 of the first lens and the object-side surface of the first auxiliary spacer element P1b, respectively. The image-side surface of the second auxiliary spacer element P1c abuts against the image-side surface of the first auxiliary spacer element P1b 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 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 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 S6 of the third lens abuts against the bearing surface of the lens barrel P0.

[0114] like Figure 9 The image shown is a schematic diagram of the optical lens structure in Example 2-2. Figure 10 The diagram shown is a structural schematic of the optical lens in Embodiment 2-3. In Embodiments 2-2 and 2-3, the abutment and contact methods of each spacer element are similar to those in Embodiment 2-1, and can be referred to the relevant description in Embodiment 2-1, which will not be repeated here.

[0115] In summary, the structural parameters of the optical lens in Embodiment 2 under Embodiments 2-1, 2-2, and 2-3 are shown in Table 5. (Unit: mm)

[0116]

[0117]

[0118] Table 5

[0119] In Embodiment 2, the first lens has positive optical power, its object-side surface S1 is convex, and its image-side surface S2 is flat. The second lens has positive optical power, its object-side surface S3 is convex, and its image-side surface S4 is concave. The third lens has negative optical power, its object-side surface S5 is convex, and its image-side surface S6 is concave; the fourth lens has positive optical power, its object-side surface S7 is convex, and its image-side surface S8 is convex.

[0120] Table 6 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).

[0121]

[0122] Table 6

[0123] Table 7 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.

[0124]

[0125]

[0126] Table 7

[0127] Figure 11 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 12 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 13 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.

[0128] according to Figures 11 to 13 It can be seen that the optical lens given in Example 2 can achieve good imaging quality.

[0129] Example 3

[0130] like Figures 14 to 19 As shown, the optical lens of Embodiment 3 is described. Figure 14 A schematic diagram of the optical lens of Embodiment 3-1 is shown. Figure 15 A schematic diagram of the optical lens of Embodiment 3-2 is shown. Figure 16 A schematic diagram of the optical lens of Embodiment 3-3 is shown.

[0131] like Figures 14 to 16 As shown, the optical 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 first auxiliary spacer element P1b, 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.

[0132] like Figure 14The 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 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 of the first spacer element P1 partially 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 partially abut against the image-side surface of the first spacer element P1 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 S6 of the third lens abuts against the bearing surface of the lens barrel P0.

[0133] like Figure 15 The diagram shown is a schematic representation of the optical lens structure of Embodiment 3-2. In Embodiment 3-2, the abutment and contact method of each spacer element is similar to that of Embodiment 3-1, and can be referred to the relevant description in Embodiment 3-1, which will not be repeated here.

[0134] like Figure 16 The diagram shown is a structural schematic of the optical lens in Embodiment 3-3. In Embodiments 3-2 and 3-3, the optical lens further includes a second auxiliary spacer element P1c. The object-side and image-side surfaces of the second auxiliary spacer element P1c are respectively connected to the image-side surface of the first auxiliary spacer element P1b and the object-side surface S3 of the second lens. The contact methods of the other spacer elements are similar to those in Embodiment 1-1, and can be referred to the relevant descriptions in Embodiment 1-1, which will not be repeated here.

[0135] 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 8. (Unit: mm)

[0136] Parameters / Examples 3-1 3-2 3-3 d2s 5.37 5.39 5.25 d2m 5.33 5.35 5.21 d3s 4.74 4.76 4.97 d3m 4.70 4.72 4.93 d0s 7.95 8.14 7.70 d0m 4.80 4.70 4.86 D0m 8.78 8.68 8.50 EP23 1.14 1.01 1.26 CP3 0.07 0.01 0.02 L 4.01 4.04 3.85 Y 0.40 0.43 0.34

[0137] Table 8

[0138] In Embodiment 3, the first lens has positive optical power, its object-side surface S1 is convex, and its image-side surface S2 is convex. The second lens has positive optical power, its object-side surface S3 is convex, and its image-side surface S4 is concave. The third lens has negative optical power, its object-side surface S5 is convex, and its image-side surface S6 is concave. The fourth lens has positive optical power, its object-side surface S7 is concave, and its image-side surface S8 is convex.

[0139] Table 9 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).

[0140]

[0141] Table 9

[0142] Table 10 shows the higher-order coefficients that can be used for each aspherical mirror in Embodiment 3, 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.

[0143]

[0144]

[0145] Table 10

[0146] Figure 17 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 18 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 19 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.

[0147] according to Figures 17 to 19 It can be seen that the optical lens given in Example 3 can achieve good imaging quality.

[0148] In summary, the optical lenses of Examples 1 to 3 respectively satisfy the relationships shown in Table 11.

[0149] Conditional / Example 1-1 1-2 1-3 2-1 2-2 2-3 3-1 3-2 3-3 f3 / f+f4 / f 0.53 0.53 0.53 0.42 0.42 0.42 0.75 0.75 0.75 (d0m-d3m) / f34 -0.04 -0.01 0.02 -0.02 -0.02 0.00 -0.01 0.00 0.01 L / (CT3+T34+CT4) 2.51 2.45 2.54 2.52 2.61 2.54 2.30 2.31 2.20 T34 / CT3 1.49 1.49 1.49 1.04 1.04 1.04 2.04 2.04 2.04 EP23 / CT3 3.09 2.81 2.76 2.77 2.73 2.54 2.98 2.65 3.30 (DT31-DT32) / EP23 0.21 0.24 0.24 0.25 0.25 0.27 0.28 0.31 0.25 R8 / (D0m-d0m) -2.22 -2.19 -2.22 -2.34 -2.57 -2.33 -1.89 -1.89 -2.07 (R7+R8) / d0s 2.50 2.43 2.54 0.88 0.86 0.88 -6.68 -6.52 -6.89 CP3 / T34 0.02 0.02 0.09 0.24 0.17 0.13 0.09 0.02 0.02 f3 / EP23 -3.74 -4.12 -4.18 -3.27 -3.32 -3.57 -4.80 -5.39 -4.33 d2m / R5+d3m / R7 0.77 0.76 0.77 0.81 0.82 0.83 0.61 0.61 0.59 (D0m-DT42) / CT4 11.00 10.67 10.34 10.26 9.89 10.08 10.95 10.78 10.48 d3s / d2s 0.86 0.89 0.90 0.87 0.90 0.86 0.88 0.88 0.95 Y 0.40 0.28 0.45 0.44 0.51 0.47 0.40 0.43 0.34 (d0s-d0m) / f 0.22 0.25 0.24 0.22 0.22 0.23 0.22 0.24 0.19 R4 / d2s+R6 / d3s 2.85 2.87 2.84 3.93 3.93 3.87 2.29 2.28 2.31

[0150] Table 11

[0151] Table 12 shows the effective focal length (unit: mm) of each lens of the optical lens in Examples 1 to 3.

[0152]

[0153]

[0154] Table 12

[0155] 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.

[0156] 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.

[0157] 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.

[0158] 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.

[0159] 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, It includes a lens barrel and a lens assembly and a spacer assembly assembled within the lens barrel. The lens group includes, along the optical axis from the object side to the image side, a first lens, a second lens, a third lens with negative optical power, and a fourth lens with positive optical power. The spacer group includes at least a third spacer element, which is located between the third lens and the fourth lens and contacts the object-side surface of the fourth lens; The effective focal length f of the optical lens, the effective focal length f3 of the third lens, and the effective focal length of the fourth lens The condition f4 satisfies: 0.40 <f3 / f+f4 / f≤0.75; The combined focal length f34 of the third lens and the fourth lens, the inner diameter d0m of the end face of the lens barrel closest to the image side, and the inner diameter d3m of the image side of the third spacer element satisfy the following condition: -0.05 < (d0m - d3m) / f34 < 0.

05.

2. The optical lens according to claim 1, characterized in that, The height L of the lens barrel, the center thickness CT3 of the third lens, the air gap T34 between the third lens and the fourth lens on the optical axis, and the center thickness CT4 of the fourth lens satisfy the following condition: 2.20≤L / (CT3+T34+CT4)<2.

65.

3. The optical lens according to claim 1, characterized in that, The radius of curvature R8 of the image-side surface of the fourth lens, the outer diameter D0m of the end face of the lens barrel closest to the image side, and the inner diameter d0m of the end face of the lens barrel closest to the image side satisfy the following condition: -2.60 <R8 / (D0m-d0m)<-1.85。 4. The optical lens according to claim 1, characterized in that, The radius of curvature R7 of the object-side surface of the fourth lens, the radius of curvature R8 of the image-side surface of the fourth lens, and the inner diameter d0s of the end face of the lens barrel closest to the object side satisfy the following: -6.90<(R7+R8) / d0s<2.

55.

5. The optical lens according to claim 1, characterized in that, The maximum thickness CP3 of the third spacer element along the extension direction of the optical axis and the air gap T34 between the third lens and the fourth lens on the optical axis satisfy: 0 <CP3 / T34<0.25。 6. The optical lens according to claim 1, characterized in that, The outer diameter D0m of the end face closest to the image side of the lens barrel, the maximum effective radius DT42 of the image side surface of the fourth lens, and the center thickness CT4 of the fourth lens satisfy the following condition: 9.85 < (D0m - DT42) / CT4 ≤ 11.

7. The optical lens according to claim 1, characterized in that, The lens barrel has a bearing surface that abuts against the lens closest to the image side of the lens group or the spacer element closest to the image side of the spacer element group. The maximum distance Y between the end face of the lens barrel closest to the image side and the bearing surface along the optical axis satisfies: 0.

25. <Y<0.55。 8. The optical lens according to claim 1, characterized in that, The inner diameter d0s of the end face of the lens barrel closest to the object side, the inner diameter d0m of the end face of the lens barrel closest to the image side, and the effective focal length f of the optical lens satisfy the following condition: 0.15 < (d0s - d0m) / f ≤ 0.

25.

9. The optical lens according to claim 1, characterized in that, The radius of curvature R5 of the object side of the third lens, the radius of curvature R6 of the image side of the third lens, and the inner diameter d3s of the object side of the third spacer element satisfy the following condition: 1.95 < (R5 + R6) / d3s ≤ 2.

60.

10. The optical lens according to any one of claims 1 to 9, characterized in that, The spacer group includes at least a second spacer element, which is located between the second lens and the third lens and contacts the object-side portion of the third lens; The air gap T34 between the third lens and the fourth lens on the optical axis, and the center thickness CT3 of the third lens, satisfy the following condition: 1.00 <T34 / CT3<2.05; The center thickness CT3 of the third lens, the image-side surface of the second spacer element, and the object-side surface of the third spacer element satisfy the following condition within the distance EP23 along the optical axis: 2.

50. <EP23 / CT3≤3.30。 11. The optical lens according to any one of claims 1 to 9, characterized in that, The spacer group includes at least a second spacer element, which is located between the second lens and the third lens and contacts the object-side surface of the third lens. The maximum effective radius DT31 of the object-side surface of the third lens, the maximum effective radius DT32 of the image-side surface of the third lens, 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 optical axis extension direction satisfy: 0.20 < (DT31 - DT32) / EP23 < 0.

35.

12. The optical lens according to any one of claims 1 to 9, characterized in that, The spacer group includes at least a second spacer element, which is located between the second lens and the third lens and contacts the object-side surface of the third lens; the effective focal length f3 of the third lens, the image-side surface of the second spacer element, and the object-side surface of the third spacer element satisfy the following conditions within the interval EP23 along the optical axis: -5.40 <f3 / EP23<-3.25。 13. The optical lens according to any one of claims 1 to 9, characterized in that, The spacer group includes at least a second spacer element, which is located between the second lens and the third lens and contacts the object-side surface of the third lens. The inner diameter d2m of the image-side surface of the second spacer element, the inner diameter d3m of the image-side surface of the third spacer element, the radius of curvature R5 of the object-side surface of the third lens, and the radius of curvature R7 of the object-side surface of the fourth lens satisfy the following condition: 0.55 <d2m / R5+d3m / R7<0.85。 14. The optical lens according to any one of claims 1 to 9, characterized in that, The spacer group includes at least a second spacer element, which is located between the second lens and the third lens and contacts the object-side surface of the third lens; the inner diameter d3s of the object-side surface of the third spacer element and the inner diameter d2s of the object-side surface of the second spacer element satisfy the following condition: 0.85 <d3s / d2s≤0.95。

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