Optical lens

Abstract

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

Description

Technical Field

[0001] The present invention relates to the technical field of optical imaging equipment, and in particular to an optical lens. Background Art

[0002] With the development of science and technology, more and more electronic products have camera functions. As users' demand for camera functions of electronic products increases, the requirements for optical lenses installed in electronic products are also gradually increasing. For example, optical lenses are required to have a larger field of view. Some optical lenses have a larger field of view by increasing the light output aperture of the lens barrel and designing the last lens. However, the maximum angle (Chief Ray Angel, CRA) when the light converges to the chip may not match the chip, resulting in poor image quality.

[0003] That is to say, the optical lens in the prior art has the problem that the maximum angle at which light converges onto the chip is not compatible with the chip. Summary of the invention

[0004] The main purpose of the present invention is to provide an optical lens to solve the problem in the prior art that the maximum angle of the optical lens when light converges to the chip is not compatible with the chip.

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

[0006] According to another aspect of the present invention, an optical lens is provided, which is suitable for imaging in the near-infrared band. The optical lens comprises: a lens barrel, and a lens group and a spacer element group arranged in the lens barrel, wherein the lens group consists of four lenses, and the lens group is sequentially a first lens, a second lens, a third lens and a fourth lens from the object side to the image side along the extension direction of the optical axis; the spacer element group comprises at least a first spacer element, and the first spacer element is located between the first lens and the second lens and contacts a part of the image side surface of the first lens; the curvature radius R1 of the object side surface of the first lens and the outer diameter D0s of the object side end surface of the lens barrel satisfy the following relationship: -2.49≤R1 / D0s≤-0.21; the curvature radius R3 of the object side surface of the second lens, the outer diameter D1m of the image side surface of the first spacer element, and the inner diameter d1m of the image side surface of the first spacer element satisfy the following relationship: 0.44≤R3 / (D1m-d1m)≤1.48.

[0007] According to another aspect of the present invention, an optical lens is provided, which is suitable for imaging in the near-infrared band. The optical lens comprises: a lens barrel, and a lens group and a spacer element group arranged in the lens barrel, wherein the lens group consists of four lenses, and the lens group comprises a first lens with negative optical power, a second lens with positive optical power, a third lens and a fourth lens in sequence from the object side to the image side along the extension direction of 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 contacts a portion of the image side surface of the first lens, the second spacer element is located between the second lens and the third lens and contacts a portion of the image side surface of the second lens, and the third spacer element is located between the second lens and the third lens and contacts a portion of the image side surface of the second lens. The three spacer elements are located between the third lens and the fourth lens and contact a portion of the image side surface of the third lens; the combined focal length f23 of the second lens and the third lens, the center thickness CT2 of the second lens on the optical axis, and the minimum distance EP23 between the first spacer element and the second spacer element in the extension direction of the optical axis satisfy: 0.9≤f23 / (CT2+EP12)≤3.64; the curvature radius R4 of the image side surface of the second lens, the curvature radius R5 of the object side surface of the third lens, the inner diameter d2s of the object side surface of the second spacer element, and the inner diameter d2m of the image side surface of the second spacer element satisfy: 2.86≤|R4| / d2s+|R5| / d2m≤4.08.

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

[0009] Furthermore, a curvature radius R5 of the object-side surface of the third lens and an inner diameter d2m of the image-side surface of the second spacing element satisfy: 0.18≤|R5| / d2m≤0.89.

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

[0011] Further, the center thickness CT3 of the third lens on the optical axis, the air gap T23 between the second lens and the third lens on the optical axis, and the minimum distance EP23 between the second spacing element and the third spacing element in the extending direction of the optical axis satisfy: 0.56≤(CT3+T23) / EP23≤2.06.

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

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

[0014] Furthermore, the spacer element group also includes a first spacer element, which is located between the first lens and the second lens and contacts a portion of the image side surface of the first lens. The minimum distance EP01 between the object side end surface of the lens barrel and the first spacer element in the extension direction of the optical axis and the center thickness CT1 of the first lens on the optical axis satisfy: 1.9≤EP01 / CT1≤2.68.

[0015] Furthermore, the spacer element group also includes a first spacer element, which is located between the first lens and the second lens and contacts a portion of the image side surface of the first lens, and the curvature radius R1 of the object side surface of the first lens, the outer diameter D1s of the object side surface of the first spacer element, and the inner diameter d1s of the object side surface of the first spacer element satisfy: -3.94≤R1 / (D1s-d1s)≤-0.33.

[0016] Furthermore, the spacer element group also includes a first spacer element, which is located between the first lens and the second lens and contacts a portion of the image side surface of the first lens, and the inner diameter d1s of the object side surface of the first spacer element and the curvature radius R2 of the image side surface of the first lens satisfy: 1.27≤|R2 / d1s|≤6.63.

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

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

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

[0020] The first lens has negative optical power;

[0021] The second lens has positive refractive power.

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

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

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

[0025] By applying the technical solution of the present invention, the optical lens is suitable for imaging in the near-infrared band. The optical lens comprises: a lens barrel, a lens group and a spacer element group arranged in the lens barrel, the lens group consists of four lenses, and the lens group is sequentially composed of a first lens, a second lens, a third lens and a fourth lens along the extension direction of the optical axis from the object side to the image side; the spacer element group comprises at least a second spacer element and a third spacer element, the second spacer element is located between the second lens and the third lens and contacts a part of the image side surface of the second lens, and the third spacer element is located between the third lens and the fourth lens and contacts a part of the image side surface of the third lens; the inner diameter d0m of the image side end surface of the lens barrel and the curvature radius R8 of the image side surface of the fourth lens satisfy the following conditions: 2.6≤d0m / |R8|≤8.67; the combined focal length f34 of the third lens and the fourth lens, the center thickness CT4 of the fourth lens on the optical axis, and the minimum distance EP23 between the second spacer element and the third spacer element in the extension direction of the optical axis satisfy the following conditions: 1.04≤f34(EP23+CT4)≤2.36.

[0026] The optical lens of the present application is composed of a lens barrel, four lenses and at least two spacer elements. By reasonably controlling the relationship between the inner diameter d0m of the image side end face of the lens barrel and the curvature radius R8 of the image side face of the fourth lens, the optical lens can not only ensure the effective width of the flange position of the fourth lens when satisfying 2.6≤d0m / |R8|≤8.67, but also control the emission angle of the light when passing through the image side face of the fourth lens, which is conducive to the emission of large-angle light and the improvement of the field of view of the optical lens. However, at the same time, it will cause a mismatch between the maximum angle of light convergence to the chip and the chip, which will lead to imaging quality problems. The present application can also reduce the impact of factors such as manufacturing tolerance and assembly accuracy of the third lens and the fourth lens on the optical transmission path by constraining the relationship between the combined focal length f34 of the third lens and the fourth lens, the center thickness CT4 of the fourth lens on the optical axis, and the minimum distance EP23 between the second spacer element and the third spacer element in the extension direction of the optical axis, thereby ensuring that the light in the third lens and the fourth lens is transmitted along a preset path and avoiding the problem of the maximum angle of light converging to the chip not matching the chip due to changes in the distance between the lenses or the center thickness, edge thickness, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0028] Figure 1 A dimensioning diagram of an optical lens of an optional embodiment of the present invention is shown;

[0029] Figure 2 A schematic structural diagram of an optical lens according to Embodiment 1-1 of the present invention is shown;

[0030] Figure 3 A schematic structural diagram of an optical lens according to Embodiment 1-2 of the present invention is shown;

[0031] Figure 4 A schematic diagram showing the structure of an optical lens according to embodiments 1 to 3 of the present invention is shown;

[0032] Figures 5 to 8 The axial chromatic aberration, astigmatism curve, distortion curve and magnification chromatic aberration curve of the optical lens of the first embodiment of the present invention are respectively shown;

[0033] Fig. 9 A schematic structural diagram of an optical lens according to Embodiment 2-1 of the present invention is shown;

[0034] Fig.10 A schematic structural diagram of an optical lens according to Embodiment 2-2 of the present invention is shown;

[0035] Fig.11 A schematic structural diagram of an optical lens according to Embodiment 2-3 of the present invention is shown;

[0036] Figures 12 to 15 The axial chromatic aberration, astigmatism curve, distortion curve and magnification chromatic aberration curve of the optical lens of the second embodiment of the present invention are respectively shown;

[0037] Fig.16 A schematic structural diagram of an optical lens according to Embodiment 3-1 of the present invention is shown;

[0038] Fig.17 A schematic structural diagram of an optical lens according to Embodiment 3-2 of the present invention is shown;

[0039] Fig.18 A schematic structural diagram of an optical lens according to Embodiment 3-3 of the present invention is shown;

[0040] Figures 19 to 22 The axial chromatic aberration, astigmatism curve, distortion curve and magnification chromatic aberration curve of the optical lens of the third embodiment of the present invention are respectively shown;

[0041] Fig.23 A schematic diagram showing the relationship between the maximum angle at which the optical lens converges to the chip and the image height according to an optional embodiment of the present invention;

[0042] Fig.24 A schematic diagram showing the relationship between the maximum angle at which an optical lens converges to a chip and the image height is shown;

[0043] Fig.25 A schematic diagram showing the relationship between the maximum angle at which an optical lens converges to a chip and the image height is shown in another example.

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

[0045] E1, first lens; P1, first spacing element; P1b, first auxiliary spacing element; E2, second lens; P2, second spacing element; P2b, second auxiliary spacing element; E3, third lens; P3, third spacing element; P3b, third auxiliary spacing 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

[0046] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0047] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0048] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0049] It should be noted that in this 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, without departing from the teaching of the present application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0050] In the 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 shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0051] In this article, the paraxial area refers to the area 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 paraxial area; 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 paraxial area. The judgment of the surface shape in the paraxial area can be based on the judgment method of the general knowledge in this field, and the positive and negative R value (R refers to the radius of curvature of the paraxial area, usually refers to the R value on the lens database (lens data) in the optical software) is used to judge the convexity and concavity. For the object side, when the R value is positive, it is judged as a convex surface, and when the R value is negative, it is judged as a concave surface; for the image side, when the R value is positive, it is judged as a concave surface, and when the R value is negative, it is judged as a convex surface. In the present application, the left side is the object side and the right side is the image side.

[0052] In order to solve the problem in the prior art that the maximum angle of the optical lens when light is converged to the chip is not compatible with the chip, the present invention provides an optical lens.

[0053] like Figures 1 to 22As shown, the optical lens is suitable for near-infrared band imaging, and the optical lens includes: a lens barrel, a lens group and a spacer element group arranged in the lens barrel, the lens group consists of four lenses, and the lens group is sequentially composed of a first lens, a second lens, a third lens and a fourth lens along the extension direction of 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 contacts a part of the image side surface of the second lens, and the third spacer element is located between the third lens and the fourth lens and contacts a part of the image side surface of the third lens; the inner diameter d0m of the image side end surface of the lens barrel and the curvature radius R8 of the image side surface of the fourth lens satisfy: 2.6≤d0m / |R8|≤8.67; the combined focal length f34 of the third lens and the fourth lens, the center thickness CT4 of the fourth lens on the optical axis, and the minimum distance EP23 between the second spacer element and the third spacer element in the extension direction of the optical axis satisfy: 1.04≤f34(EP23+CT4)≤2.36.

[0054] The optical lens of the present application is composed of a lens barrel, four lenses and at least two spacer elements. By reasonably controlling the relationship between the inner diameter d0m of the image side end face of the lens barrel and the curvature radius R8 of the image side face of the fourth lens, the optical lens can not only ensure the effective width of the flange position of the fourth lens when satisfying 2.6≤d0m / |R8|≤8.67, but also control the emission angle of the light when passing through the image side face of the fourth lens, which is conducive to the emission of large-angle light and the improvement of the field of view of the optical lens. However, at the same time, it will cause a mismatch between the maximum angle of light convergence to the chip and the chip, which will lead to imaging quality problems. The present application can also reduce the impact of factors such as manufacturing tolerance and assembly accuracy of the third lens and the fourth lens on the optical transmission path by constraining the relationship between the combined focal length f34 of the third lens and the fourth lens, the center thickness CT4 of the fourth lens on the optical axis, and the minimum distance EP23 between the second spacer element and the third spacer element in the extension direction of the optical axis, thereby ensuring that the light in the third lens and the fourth lens is transmitted along a preset path and avoiding the problem of the maximum angle of light converging to the chip not matching the chip due to changes in the distance between the lenses or the center thickness, edge thickness, etc.

[0055] In addition, refer to Table 1 and Figure 23 to Figure 25 As shown, Fig.23 The figure shows the relationship between the maximum angle of the optical lens converging to the chip and the image height when d0m / |R8|=3.74 and f34(EP23+CT4)=1.24. Fig.24 The figure shows the relationship between the maximum angle of the optical lens converging to the chip and the image height when d0m / |R8|=3.74 and f34(EP23+CT4)=0.9. Fig.25The figure shows the relationship between the maximum angle of the optical lens converging to the chip and the image height when d0m / |R8|=3.74 and f34(EP23+CT4)=2.5.

[0056] Depend on Figure 23 to Figure 25 It can be seen that when f34(EP23+CT4)=1.24, the maximum angle converged to the chip is linearly related to the image height, indicating that the maximum angle converged to the chip matches the chip, and the performance is better. When f34(EP23+CT4)=0.9 is satisfied, the maximum angle converged to the chip is no longer linearly related to the image height, indicating that the maximum angle converged to the chip and the chip will not match, and the performance is poor. When f34(EP23+CT4)=2.5 is satisfied, the maximum angle converged to the chip is no longer linearly related to the image height, indicating that the maximum angle converged to the chip and the chip will not match, and the performance is poor. It can be seen that when f34(EP23+CT4) is in the range of 1.04 to 2.36, the maximum angle of the optical lens converging to the chip matches the chip. Therefore, the present application can ensure that the light is transmitted along a preset path in the third lens and the fourth lens by constraining 1.04≤f34(EP23+CT4)≤2.36, thereby effectively reducing the impact of factors such as manufacturing tolerance and assembly accuracy of the third lens and the fourth lens on the optical transmission path, and avoiding the problem of the maximum angle of light converging to the chip being incompatible with the chip due to changes in the spacing or thickness of the lens combination.

[0057]

[0058] Table 1

[0059] It should be noted that the present application limits f34 (EP23 + CT4) within a reasonable range to control the deflection of light, optimize the size of the lens and the spacing element, ensure the processing accuracy of the parts, and improve the smoothness of the light path to solve the problem of mismatch between the maximum angle of convergence to the chip and the chip when d0m / |R8| is in the range of 2.6 to 8.67. When f34 (EP23 + CT4) meets the above range, the purpose of improving the matching degree between the maximum angle of convergence to the chip and the chip can be achieved, and it does not depend on the focal length of the lens and the surface shape of the lens. The focal length and surface shape of the lens are further optimization of the optical lens 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. The optical system meets: 2.6≤d0m / |R8|≤8.67; 1.04≤f34 (EP23 + CT4)≤2.36, when the maximum angle of convergence to the chip of the optical lens can match the chip.

[0060] For example, the first lens has negative focal power, and the second lens has positive focal power. For another example, the object side surface of the first lens is a concave surface, and the object side surface of the second lens is a convex surface. The optical lens can be simulated by software and / or tools such as ZEMAX and CODEV. Preferably, the optical lens can be simulated by CODEV. In the process of simulation using software and / or tools such as the above, the surface shape of each lens can be simulated and appropriately adjusted according to the surface shape of the software and / or tools used.

[0061] In some optional embodiments, the radius of curvature R4 of the image side surface of the second lens, the refractive index N2 of the second lens, and the outer diameter D2s of the object side surface of the second spacing element satisfy: 0.84≤|R4*N2 / D2s|≤2.83. If the angle of the outgoing light of the second lens is unreasonable, or the second lens does not match its refractive index, strong stray light may be generated, forming a ghost image. By constraining the relationship between the radius of curvature of the image side surface of the second lens, the refractive index of the second lens, and the outer diameter of the object side surface of the second spacing element, it can be ensured that the light is transmitted at an appropriate angle after passing through the second lens, thereby optimizing the light path of the entire lens, reducing multiple reflections and refractions in the light path, and improving the transmission efficiency of the light. At the same time, matching with the refractive index of the second lens can control the energy of the ghost image spot to ensure that its impact on imaging is minimized. In addition, |R4*N2 / D2s| is constrained within a reasonable range to control the exit angle of light from the second lens. At the same time, the second spacing element can absorb part of the light deflected at a large angle and reduce the light directed to the inner wall of the lens barrel, thereby reducing the generation of stray light and improving the imaging quality of the optical lens.

[0062] In some optional embodiments, the curvature radius R5 of the object side surface of the third lens and the inner diameter d2m of the image side surface of the second spacing element satisfy: 0.18≤|R5| / d2m≤0.89. By constraining the relationship between the curvature radius of the object side surface of the third lens and the inner diameter of the image side surface of the second spacing element, the deflection angle of the light when entering the third lens can be effectively controlled, and the second spacing element can block the edge of the effective diameter of the object side surface of the third lens to avoid the light from being reflected between the second lens and the third lens, which is beneficial to improving the imaging quality of the optical lens.

[0063] In some optional embodiments, the curvature radius R6 of the image side surface of the third lens, the outer diameter D3s of the object side surface of the third spacing element, and the inner diameter d3s of the object side surface of the third spacing element satisfy: 0.28≤|R6| / (D3s-d3s)≤0.81. By constraining |R6| / (D3s-d3s) within a reasonable range, the deflection angle of the light passing through the image side surface of the third lens can be controlled, which helps to reduce the energy of the ghost image spot, improve the contrast and clarity of the image, and ensure that the imaging light passes through the third spacing element smoothly. At the same time, the third spacing element can also absorb the reflected stray light generated by the edge area of ​​the image side surface of the third lens, which is beneficial to improving the imaging quality of the optical lens.

[0064] In some optional embodiments, the center thickness CT3 of the third lens on the optical axis, the air gap T23 between the second lens and the third lens on the optical axis, and the minimum distance EP23 between the second spacing element and the third spacing element in the extension direction of the optical axis satisfy: 0.56≤(CT3+T23) / EP23≤2.06. By constraining (CT3+T23) / EP23 within a reasonable range, it is helpful to ensure the uniformity of the center thickness and edge thickness distribution of the third lens, and to improve the uniformity of the overall thickness of the third lens. At the same time, it is ensured that the change of the air gap between the second lens and the third lens before and after baking of the optical lens is within a reasonable range, so as to prevent a large difference in the optical performance of the optical lens.

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

[0066] In some optional embodiments, the outer diameter D0m of the image side end surface of the lens barrel and the outer diameter D0s of the object side end surface of the lens barrel satisfy: 0.22mm≤D0m-D0s≤0.99mm. By constraining D0m-D0s within a reasonable range, so that there is a small difference between the outer diameter of the image side end surface of the lens barrel and the outer diameter of the object side end surface of the lens barrel, the step difference of the internal lens is also small, which helps to improve the assembly stability. At the same time, when the outer diameter of the image side end surface of the lens barrel and the outer diameter of the object side end surface of the lens barrel are small, the effect of a small head can be achieved, which facilitates the optical lens to be applicable to more terminal devices.

[0067] In some optional embodiments, the spacer element group further includes a first spacer element, the first spacer element is located between the first lens and the second lens and contacts a portion of the image side surface of the first lens, and the minimum distance EP01 between the object side end surface of the lens barrel and the first spacer element in the direction of extension of the optical axis and the center thickness CT1 of the first lens on the optical axis satisfy: 1.9≤EP01 / CT1≤2.68. By constraining EP01 / CT1 within a reasonable range, the difference between the center thickness and the edge thickness of the first lens is not too large while ensuring the structural strength of the lens barrel, and the uniformity of the thickness of the first lens at various locations is ensured, which is conducive to reducing the molding difficulty of the first lens, and at the same time improving the assembly stability of the first lens and the stability of the lens barrel structure.

[0068] In some optional embodiments, the spacer element group further includes a first spacer element, the first spacer element is located between the first lens and the second lens and contacts a portion of the image side surface of the first lens, and the curvature radius R1 of the object side surface of the first lens, the outer diameter D1s of the object side surface of the first spacer element, and the inner diameter d1s of the object side surface of the first spacer element satisfy: -3.94≤R1 / (D1s-d1s)≤-0.33. R1 / (D1s-d1s) is constrained within a reasonable range, while ensuring the stability of the first lens, the deflection angle of the light entering the first lens is controlled to ensure the field of view of the optical lens, and at the same time, it is matched with the outer diameter and inner diameter of the object side surface of the first spacer element, which is conducive to reducing the generation of stray light.

[0069] In some optional embodiments, the spacer element group further includes a first spacer element, the first spacer element is located between the first lens and the second lens and contacts a portion of the image side surface of the first lens, and the inner diameter d1s of the object side surface of the first spacer element and the curvature radius R2 of the image side surface of the first lens satisfy: 1.27≤|R2 / d1s|≤6.63. By constraining |R2 / d1s| within a reasonable range, the curvature degree of the effective diameter of the image side surface of the first lens can be controlled, and the effective diameter position of the first lens blocked by the first spacer element can be controlled, which can effectively reduce the light deflected toward the inner wall of the lens barrel, effectively reduce the generation of stray light, and improve the imaging quality of the optical lens.

[0070] In some optional embodiments, the spacer element group further includes a first spacer element, the first spacer element is located between the first lens and the second lens and contacts a portion of the image side surface of the first lens, and the air gap T12 between the first lens and the second lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, and the minimum distance EP12 between the first spacer element and the second spacer element in the extension direction of the optical axis satisfy: 1.12≤(T12+CT2) / EP12≤2.21. Constraining (T12+CT2) / EP12 within a reasonable range can ensure the uniformity of the entire second lens, avoid the second lens molding problem caused by the excessive edge thickness or center thickness of the second lens, reduce the risk of deformation of the second lens, and limit the air gap between the first lens and the second lens, prevent the air gap between the first lens and the second lens from being too large, which makes the first lens and the second lens more sensitive, and effectively reduce the sensitivity of the first lens and the second lens.

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

[0072] In addition, in another embodiment of the present invention, an optical lens is provided, which is suitable for imaging in the near-infrared band. The optical lens includes: a lens barrel and a lens group and a spacer element group arranged in the lens barrel, the lens group consists of four lenses, and the lens group is 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 extension direction of the optical axis; the spacer element group includes at least a first spacer element, and the first spacer element is located between the first lens and the second lens and contacts a portion of the image side surface of the second lens; the curvature radius R1 of the object side surface of the first lens and the outer diameter D0s of the object side end surface of the lens barrel satisfy: -2.49≤R1 / D0s≤-0.21; the curvature radius R3 of the object side surface of the second lens, the outer diameter D1m of the image side surface of the first spacer element, and the inner diameter d1m of the image side surface of the first spacer element satisfy: 0.44≤R3 / (D1m-d1m)≤1.48.

[0073] The optical lens of the present application is composed of a lens barrel, four lenses and at least two spacer elements. By reasonably controlling the relationship between the curvature radius R1 of the object side surface of the first lens and the outer diameter D0s of the object side end surface of the lens barrel, the optical lens can not only have a small head when satisfying -2.49≤R1 / D0s≤-0.21, which is beneficial to miniaturization of the optical lens, but also helps to ensure the incident angle of light incident on the object side surface of the first lens, ensure the object side field of view of the optical lens, facilitate large-angle light to be incident on the optical lens, and improve the imaging ability of the optical lens in a dark environment. However, since the object side surface of the first lens diverges the light, it is easy to cause part of the light to be deflected toward the inner wall surface of the lens barrel to form stray light. The present application controls the deflection angle of the light emitted through the first lens when entering the second lens by constraining R3 / (D1m-d1m) within a reasonable range, and controls the inner diameter of the image side surface of the first spacing element and the supporting width of the image side surface of the first spacing element, thereby effectively absorbing the light deflected toward the inner wall surface of the lens barrel, reducing the light deflected at a large angle, thereby reducing the generation of stray light and reducing the energy of stray light.

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

[0075] The optical lens of the present application is composed of a lens barrel, four lenses and at least two spacer elements. By reasonably controlling the relationship between the combined focal length f23 of the second lens and the third lens, the center thickness CT2 of the second lens on the optical axis, and the minimum distance EP23 between the first spacer element and the second spacer element in the extension direction of the optical axis, the optical lens satisfies 0.9≤f23 / (CT2+EP12)≤3.64, the center thickness of the second lens can be controlled, and by controlling the distance between the first spacer element and the second spacer element, the edge thickness of the second lens can be limited to a certain range, which is conducive to ensuring the structural strength of the second lens and improving the assembly stability. However, it is easy to cause reflected stray light in the effective diameter structure area of ​​the second lens, affecting the imaging quality. In order to reduce the occurrence of such reflected stray light, the present application controls the relationship between the curvature radius R4 of the image side surface of the second lens, the curvature radius R5 of the object side surface of the third lens, the inner diameter d2s of the object side surface of the second spacer element, and the inner diameter d2m of the image side surface of the second spacer element, thereby controlling the deflection angle of the light when it is emitted through the image side surface of the second lens, and the deflection angle when it enters the object side surface of the third lens, so as to reduce the deflection of light at large angles. The restriction of the inner diameters of the object side surface and the image side surface of the second spacer element can block the edge positions of the effective diameters of the second lens and the third lens, thereby reducing the occurrence of reflected stray light and improving the imaging quality.

[0076] Of course, this embodiment may also include other parameter formulas in the above embodiment, which will not be described one by one here.

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

[0078] In some optional embodiments, at least one trimming spacer element may be included in the plurality of spacer elements. The outer circumference of the trimming spacer element may have a trimming portion and a non-trimming portion, and the outer diameter of the trimming portion of the trimming spacer element is smaller than the outer diameter of the non-trimming portion of the trimming spacer element, and the outer diameter of the spacer element generally refers to the maximum outer diameter of the non-trimmed portion.

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

[0080] The optical lens in the present application may use multiple lenses, such as the four lenses mentioned above. In the present application, at least one of the mirror surfaces of each lens is an aspherical mirror surface. The characteristics of an aspherical lens are: the curvature changes continuously from the center of the lens to the periphery of the lens. Unlike a spherical lens with a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has a better curvature radius characteristic, and has the advantages of improving distortion aberration and improving astigmatism aberration. After using an aspherical 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, without departing from the technical solution claimed in the present application, the number of lenses constituting the optical lens can be changed to obtain the various results and advantages described in this specification. For example, although four lenses are described as an example in the embodiments, the optical lens is not limited to including four lenses. If necessary, the optical lens may also include other numbers of lenses.

[0082] Figure 1 A schematic diagram of the dimensions of an optical lens of the present application is shown. Figure 1 Parameters such as d1s, d1m, D1s, D1m, d2m, D2s, d3s, D2m, d0s, d0m, D0s, D0m, CP1, CP2, EP12, and L are indicated in the figure to clearly and intuitively understand the meaning of the parameters. In order to facilitate the description of the optical lens and the surface shape of the specific lens, these parameters will no longer be reflected in the drawings when describing the specific embodiments later.

[0083] The following further describes examples of specific surface shapes and parameters of the optical lens applicable to the above-mentioned embodiments with reference to the accompanying drawings.

[0084] It should be noted that in the following embodiment 1, there are three examples, namely, embodiment 1-1, embodiment 1-2, and embodiment 1-3; in embodiment 2, there are three examples, namely, embodiment 2-1, embodiment 2-2, and embodiment 2-3; and in embodiment 3, there are three examples, namely, embodiment 3-1, embodiment 3-2, and embodiment 3-3. In the two examples of the same embodiment, the parameters such as the radius of curvature, the center thickness, the spacing distance between the lenses, and the coefficients of the higher-order terms of the optical lenses of the first to fourth lenses are the same, but the parameters such as the thickness, the inner diameter, and the outer diameter of the lens barrel, the first spacing element, the second spacing element, and the third spacing element, as well as the shapes of some lenses are different. In other words, the main structures for imaging are the same, but the auxiliary structures for imaging are different.

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

[0086] Embodiment 1

[0087] like Figures 2 to 5 As shown, the optical lens of embodiment 1 is described. Figure 2 The structure diagram of the optical lens of Example 1-1 is shown. Figure 3 The structure diagram of the optical lens of Example 1-2 is shown. Figure 4 The schematic diagrams of the structures of the optical lenses of Examples 1-3 are shown.

[0088] like Figures 2 to 4 As shown, the optical lens includes a lens barrel, four lenses and multiple spacing elements. The lens barrel includes 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, which are arranged in sequence from the object side to the image side.

[0089] like Figure 2 1-1, is the structural representation of the optical lens of embodiment 1-1. In this example, the object side surface S1 of the first lens partially abuts with the lens barrel. The object side surface and the image side surface of the first spacing element P1 partially abut with 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 spacing element partially abut with 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 spacing element partially abut with the image side surface S6 of the third lens and the object side surface S7 of the fourth lens respectively, and the image side surface S8 of the fourth lens is spaced apart from the lens barrel.

[0090] like Figure 3 , which is a schematic diagram of the structure of the optical lens of Example 1-2. In this example, the optical lens further includes a second auxiliary spacing element P2b, which is located between the second spacing element P2 and the third lens E3, and the object side surface and image side surface of the second auxiliary spacing element are respectively abutted against the image side surface of the second spacing element and the object side surface S5 of the third lens, and the abutting manner of other spacing elements is the same as that of Example 1-1, and reference may be made to the relevant description in Example 1-1, which will not be repeated here.

[0091] like Figure 4 As shown, it is a schematic diagram of the structure of the optical lens of Example 1-3. In this example, the optical lens further includes a third auxiliary spacing element P3b, and the third auxiliary spacing element P3b is located between the third spacing element P3 and the fourth lens E4. The object side surface and the image side surface of the third auxiliary spacing element are respectively abutted against the image side surface of the third spacing element and the object side surface S7 of the fourth lens. The supporting and abutting manner of other spacing elements is the same as that of Example 1-1. Please refer to the relevant description in Example 1-1 and will not be repeated here.

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

[0093] In the first embodiment, 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 object side S3 of the second lens is a convex surface, and the image side S4 of the second lens is a concave surface. The object side S5 of the third lens is a convex surface, and the image side S6 of the third lens is a convex surface. The object side S7 of the fourth lens is a convex surface, and the image side S8 of the fourth lens is a concave surface. S9 and S10 in the following table 2 can be the surface of a filter or a protective glass, while S11 is an imaging surface, and STO is a stop, which is not shown in the figure.

[0094] Table 2 shows the basic structural parameters of the optical lens of Example 1, wherein the units of the radius of curvature and thickness / distance are all millimeters.

[0095]

[0096] Table 2

[0097] In the first embodiment, the object side surface and the image side surface of the first lens E1 to the fourth lens E4 are all aspherical surfaces, and the surface shape of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0098]

[0099] Wherein, x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface, c=1 / R, that is, the paraxial curvature c is the reciprocal of the curvature radius R in the above Table 1; k is the cone coefficient; Ai is the correction coefficient of the i-th order of the aspheric surface. The following Table 3 lists the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, and A28 that can be used for each aspheric mirror surface S1-S8 in Example 1.

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

[0101] Table 3

[0102] Figure 5 The axial chromatic aberration curve of the optical lens of the first embodiment is shown, which indicates the deviation of the focusing point of light rays of different wavelengths after passing through the optical lens. Figure 6 The astigmatism curve of the optical lens of Example 1 is shown, which represents the meridional image curvature and the sagittal image curvature. Figure 7 The distortion curve of the optical lens of the first embodiment is shown, which indicates the distortion magnitude values ​​corresponding to different field angles. Figure 8The magnification chromatic aberration curve of the optical lens of Example 1 is shown, which represents the deviation of different image heights on the imaging surface after the light passes through the lens.

[0103] according to Figures 5 to 8 It can be seen that the optical lens provided in the first embodiment can achieve good imaging quality.

[0104] Embodiment 2

[0105] like Figures 9 to 15 As shown, the optical lens of the second embodiment is described. Fig. 9 The structure diagram of the optical lens of Example 2-1 is shown. Fig.10 FIG. 2 shows a schematic structural diagram of an optical lens of Example 2-2. Fig.11 A schematic structural diagram of the optical lens of Example 2-3 is shown.

[0106] like Figures 9 to 11 As shown, the optical lens includes a lens barrel, four lenses and multiple spacing elements. The lens barrel includes 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, which are arranged in sequence from the object side to the image side.

[0107] like Fig. 9 , it is a structural schematic diagram of the optical lens of embodiment 2-1. In this example, the optical lens also includes a first auxiliary spacing element P1b, the first auxiliary spacing element P1b is located between the first spacing element P1 and the second lens E2, and the object side surface S1 of the first lens partially abuts with the lens barrel. The object side surface of the first spacing element P1 partially abuts with the image side surface S2 of the first lens. The object side surface and the image side surface of the first auxiliary spacing element P1b partially abut with the image side surface of the first spacing element and the object side surface S3 of the second lens respectively. The object side surface and the image side surface of the second spacing element partially abut with 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 spacing element partially abut with the image side surface S6 of the third lens and the object side surface S7 of the fourth lens respectively, and the image side surface S8 of the fourth lens is spaced apart from the lens barrel.

[0108] like Fig.10 The structure diagram of the optical lens of Example 2-2 is shown in FIG. The supporting and abutting manner of each spacing element is the same as that of Example 2-1, and the relevant description in Example 2-1 may be referred to, and will not be repeated here.

[0109] like Fig.11As shown, it is a schematic diagram of the structure of the optical lens of Example 2-3. In this example, the optical lens does not have a first auxiliary spacing element P1b, and the image side surface of the first spacing element is partially abutted against the object side surface S3 of the second lens. The supporting and abutting manner of other spacing elements is the same as that of Example 1-1. Please refer to the relevant description in Example 1-1 and will not be repeated here.

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

[0111] In the second embodiment, 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 convex surface. The object side surface S3 of the second lens is a convex surface, and the image side surface S4 of the second lens is a convex surface. The object side surface S5 of the third lens is a convex surface, and the image side surface S6 of the third lens is a concave surface. 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. S9 and S10 in the following table 4 can be the surface of a filter or a protective glass, while S11 is an imaging surface, and STO is a stop, which is not shown in the figure.

[0112] Table 4 shows the basic structural parameters of the optical lens of Example 2, wherein the units of the radius of curvature and thickness / distance are all millimeters.

[0113]

[0114] Table 4

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

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

[0117] Table 5

[0118] Fig.12 The axial chromatic aberration curve of the optical lens of the second embodiment is shown, which indicates the deviation of the focusing point of light rays of different wavelengths after passing through the optical lens. Fig.13 The astigmatism curve of the optical lens of Example 2 is shown, which represents the meridional image curvature and the sagittal image curvature. Fig.14 The distortion curve of the optical lens of the second embodiment is shown, which indicates the distortion magnitude values ​​corresponding to different field angles. Fig.15 The magnification chromatic aberration curve of the optical lens of Example 2 is shown, which represents the deviation of different image heights on the imaging surface after the light passes through the lens.

[0119] according to Figures 12 to 15 It can be seen that the optical lens provided in the second embodiment can achieve good imaging quality.

[0120] Embodiment 3

[0121] like Figures 16 to 22 As shown, the optical lens of embodiment 3 is described. Fig.16 The structure diagram of the optical lens of Example 3-1 is shown. Fig.17 FIG. 3 is a schematic diagram showing the structure of the optical lens of Example 3-2. Fig.18 A schematic structural diagram of the optical lens of Example 3-3 is shown.

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

[0123] like Fig.16 3-1. It is a schematic diagram of the structure of the optical lens of embodiment 3-1. In this example, the object side surface S1 of the first lens partially abuts against the lens barrel. The object side surface and the image side surface of the first spacing 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 the image side surface of the second spacing element 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 the image side surface of the third spacing element partially abut against the image side surface S6 of the third lens and the object side surface of the third auxiliary spacing element respectively. The image side surface of the third auxiliary spacing element partially abuts against the object side surface S7 of the fourth lens, and the image side surface S8 of the fourth lens is spaced apart from the lens barrel.

[0124] like Fig.17 The structure diagram of the optical lens of Example 3-2 is shown in FIG. The supporting and abutting manner of each spacing element is the same as that of Example 3-1, and the relevant description in Example 3-1 may be referred to, and will not be repeated here.

[0125] like Fig.18 The structure diagram of the optical lens of Example 3-3 is shown in FIG. The supporting and abutting manner of each spacing element is the same as that of Example 3-1, and the relevant description in Example 3-1 may be referred to, and will not be repeated here.

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

[0127] In embodiment three, 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 convex surface. The object side surface S3 of the second lens is a convex surface, and the image side surface S4 of the second lens is a convex surface. 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 object side surface S7 of the fourth lens is a convex surface, and the image side surface S8 of the fourth lens is a convex surface. S9 and S10 in the following table 6 can be the surface of a filter or a protective glass, while S11 is an imaging surface, and STO is a stop, which is not shown in the figure.

[0128] Table 6 shows the basic structural parameters of the optical lens of Example 3, wherein the units of the radius of curvature and thickness / distance are all millimeters.

[0129]

[0130] Table 6

[0131] Table 7 below gives the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, and A28 that can be used for the aspheric mirror surfaces S1-S8 in Example 3. The surface shape of each aspheric surface can be defined by the formula (1) given in the above-mentioned Example 1.

[0132] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 A22 A24 A26 A28 S1 3.70E-01 -4.14E-02 1.02E-02 -3.66E-03 7.10E-04 -2.96E-04 4.36E-05 2.74E-07 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S2 2.02E-01 -2.76E-02 5.40E-03 -2.14E-03 5.59E-04 -1.49E-04 4.40E-05 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S3 -3.11E-03 -1.55E-04 -4.84E-05 4.21E-06 -1.99E-06 5.10E-06 6.97E-08 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S4 1.12E-01 5.65E-03 1.89E-03 6.49E-04 3.41E-04 1.36E-04 3.39E-05 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S5 2.20E-01 -3.01E-02 2.64E-03 -2.52E-03 2.34E-04 -1.17E-04 3.86E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S6 -4.41E-03 9.83E-03 3.27E-04 -2.49E-03 -8.44E-04 -1.02E-05 1.21E-04 2.09E-05 5.78E-06 1.81E-06 5.44E-07 2.17E-07 0.00E+00 S7 -5.93E-01 1.14E-01 -1.83E-02 4.68E-03 -1.63E-03 1.26E-03 -5.95E-04 -2.41E-05 -1.45E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S8 -5.55E-01 3.73E-02 4.16E-03 6.63E-04 -1.50E-03 1.08E-03 -2.14E-04 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00

[0133] Table 7

[0134] Fig.19 The axial chromatic aberration curve of the optical lens of the third embodiment is shown, which indicates the deviation of the focusing point of light rays of different wavelengths after passing through the optical lens. Fig. 20 The astigmatism curve of the optical lens of Example 3 is shown, which represents the meridional image curvature and the sagittal image curvature. Fig.21 The distortion curve of the optical lens of the third embodiment is shown, which indicates the distortion magnitude values ​​corresponding to different field angles. Fig. 22 The magnification chromatic aberration curve of the optical lens of Example 3 is shown, which represents the deviation of different image heights on the imaging surface after the light passes through the lens.

[0135] according to Figures 19 to 22 It can be seen that the optical lens provided in the third embodiment can achieve good imaging quality.

[0136] In summary, the optical lenses of Embodiments 1 to 3 respectively satisfy the relationship shown in Table 8.

[0137] Conditional / Example 1-1 1-2 1-3 2-1 2-2 2-3 3-1 3-2 3-3 EP01 / CT1 2.21 2.04 2.12 2.25 2.682 2.56 2.12 1.90 2.08 R1 / (D1s-d1s) -3.50 -3.31 -3.93 -0.77 -0.334 -0.36 -2.05 -2.14 -1.30 |R2 / d1s| 1.37 1.39 1.27 2.26 3.547 3.55 6.60 6.63 6.62 (T12+CT2) / EP12 1.68 2.21 1.71 1.53 1.81 1.71 1.12 1.13 1.14 R3 / (D1m-d1m) 1.34 1.29 1.48 0.90 0.44 0.48 0.76 0.83 0.50 |R4*N2 / D2s| 1.73 1.71 1.88 1.21 0.85 0.91 2.83 2.60 2.16 |R5| / d2m 0.65 0.54 0.64 0.89 0.89 0.89 0.18 0.18 0.18 |R6| / (D3s-d3s) 0.59 0.53 0.81 0.63 0.35 0.39 0.32 0.37 0.28 (CT3+T23) / EP23 1.27 1.43 1.63 0.67 0.56 0.60 1.76 1.84 2.06 f34(EP23+CT4) 1.04 1.13 1.24 2.36 2.16 2.24 1.25 1.26 1.30 d0m / |R8| 3.88 4.26 3.74 6.20 8.67 8.17 2.91 2.60 3.08 R1 / D0s -2.24 -2.13 -2.49 -0.30 -0.21 -0.22 -0.89 -1.11 -0.68 D0m-D0s 0.22 0.30 0.33 0.33 0.44 0.27 0.66 0.99 0.42 F23 / (CT2+EP12) 1.05 1.25 1.06 0.90 0.99 0.96 3.60 3.62 3.64 |R4| / d2s+|R5| / d2m 3.99 3.72 4.08 2.88 2.86 2.86 3.23 3.25 3.29

[0138] Table 8

[0139] Table 9 shows some parameters of the optical lenses of Examples 1 to 3 (unit: mm).

[0140] Example parameters 1-1 1-2 1-3 2-1 2-2 2-3 3-1 3-2 3-3 d1s 0.421 0.415 0.454 0.900 0.573 0.573 0.719 0.716 0.717 d1m 0.421 0.455 0.414 0.758 0.573 0.613 0.719 0.752 0.753 D1s 2.512 2.632 2.317 1.878 2.814 2.675 1.859 1.805 2.509 D1m 2.512 2.632 2.317 1.855 2.814 2.675 1.859 1.805 2.509 d2s 0.875 0.920 0.850 0.813 0.819 0.820 1.109 1.099 1.085 d2m 0.875 1.056 0.890 0.813 0.819 0.820 1.109 1.135 1.121 D2s 2.572 2.608 2.377 2.059 2.934 2.735 1.959 2.135 2.569 d3s 1.041 1.035 1.184 0.955 0.922 0.936 1.359 1.349 1.302 D3s 2.632 2.812 2.344 2.119 2.994 2.795 2.359 2.222 2.449 d0m 2.798 3.070 2.695 2.376 3.321 3.127 2.852 2.555 3.024 D0s 3.270 3.439 2.940 2.470 3.592 3.349 2.632 2.103 3.423 D0m 3.488 3.736 3.268 2.797 4.030 3.621 3.294 3.094 3.844 EP01 1.104 1.020 1.058 0.854 1.017 0.971 0.656 0.590 0.643 EP12 0.486 0.369 0.478 0.623 0.525 0.555 0.310 0.307 0.304 EP23 0.505 0.450 0.393 0.390 0.460 0.431 0.259 0.248 0.221 f1 -0.98 -0.98 -0.98 -2.47 -2.47 -2.47 -8.99 -8.99 -8.99 f2 77.30 77.30 77.30 1.23 1.23 1.23 1.11 1.11 1.11 f3 0.77 0.77 0.77 9.85 9.85 9.85 -3.15 -3.15 -3.15 f4 -29.68 -29.68 -29.68 1.73 1.73 1.73 1.32 1.32 1.32 f34 0.71 0.71 0.71 1.76 1.76 1.76 1.17 1.17 1.17 f23 0.79 0.79 0.79 1.02 1.02 1.02 2.23 2.23 2.23

[0141] Table 9

[0142] The present application also provides an imaging device, whose electronic photosensitive element can be a photosensitive coupled device (CCD) or a complementary metal oxide semiconductor element (CMOS). The imaging device can be an independent imaging device such as a digital camera, or an imaging module integrated in a mobile electronic device such as a mobile phone. The imaging device is equipped with the optical lens described above.

[0143] Obviously, the above-described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0144] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0145] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0146] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

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

36.

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

83.

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

89.

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

81.

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

06.

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

21.

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

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

68.

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

33.

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

63.

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

21.

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

48.

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

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

Images