Optical imaging lens

Abstract

The invention provides an optical imaging lens and electronic equipment. The optical imaging lens sequentially comprises a first lens, a second lens, a third lens and a fourth lens from an object side to an image side along an optical axis, the optical imaging lens also comprises a plurality of spacing elements, the plurality of spacing elements comprise a first spacing element, a second spacing element and a third spacing element, and 0.30 < = f1 / R1lt; 0.70, 0.90 lt, 0.70, 0.90 lt; f34 / f2 is less than or equal to 1.25, 0.50 lt; eP01 / (EP12 + sigma CP1) lt; 1.25, f1 is the effective focal length of the first lens, R1 is the curvature radius of the object side surface of the first lens, f34 is the combined focal length of the third lens and the fourth lens, f2 is the effective focal length of the second lens, EP01 is the distance from the object side end surface of the lens barrel to the object side surface of the first spacing element along the optical axis direction, and R1 is the curvature radius of the object side surface of the first lens; eP12 is the spacing distance between the first spacing element and the second spacing element in the optical axis direction, and sigma CP1 is the sum of the maximum thicknesses of all the spacing elements between the first lens and the second lens in the optical axis direction. According to the optical imaging lens, the lens cracking possibility is reduced, and the production yield and the long-term stability of the lens are improved.

Description

Technical Field

[0001] This application relates to the field of optics, and more specifically, to an optical imaging lens. Background Technology

[0002] With the advancement of science and technology and social development, the application of optical imaging lenses is becoming increasingly widespread, which places higher demands on them. For example, increased security awareness and the growing prevalence of security monitoring facilities have led to higher requirements from consumers for the monitoring environment and the images displayed, who expect to capture clear images in various environments. To achieve superior optical performance such as high resolution and a wide field of view, the optical system design of optical imaging lenses has become increasingly complex. They typically require the assembly of multiple lenses with different curvatures and materials according to precise optical spacing and coaxiality requirements—a process known as high-precision assembly and adjustment. This assembly process is the core of optical imaging lens manufacturing; its assembly precision determines the final image quality of the lens, thus requiring extremely high levels of refinement and stability in the assembly process.

[0003] In the high-precision assembly of optical imaging lenses, the interaction between the lens material properties and the assembly environment makes stress concentration a common technical challenge in the industry. Cracking caused by stress concentration in the lens has a significant negative impact on the production and use of optical imaging lenses. Summary of the Invention

[0004] One aspect of an embodiment of the present application provides an optical imaging lens, which sequentially includes, along the optical axis from the object side to the image side: a first lens with a negative optical power, a second lens with a positive optical power, a third lens with a positive optical power, and a fourth lens with a negative optical power. The object side surface of the first lens is concave, and the image side surface of the first lens is concave; the object side surface of the second lens is convex, and the image side surface of the second lens is convex; the object side surface of the third lens is convex, and the image side surface of the third lens is convex; the object side surface of the fourth lens is concave, and the image side surface of the fourth lens is convex; there is an axial air gap between each adjacent lens among the first lens, the second lens, the third lens, and the fourth lens, and the axial air gap between the third lens and the fourth lens is the minimum value of the axial air gaps between each adjacent lens. The optical imaging lens further includes a plurality of spacer elements, and the plurality of spacer elements include a first spacer element, a second spacer element, and a third spacer element. The first spacer element is placed on the image side of the first lens and contacts the image side surface of the first lens; the second spacer element is placed on the image side of the second lens and contacts the image side surface of the second lens; the third spacer element is placed on the image side of the third lens and contacts the image side surface of the third lens; the plurality of spacer elements, the first lens, the second lens, the third lens, and the fourth lens are placed in a lens barrel, 0.30 ≤ f1 / R1 < 0.70, 0.90 < f34 / f2 ≤ 1.25, 0.50 < EP01 / (EP12 + ∑CP1) < 1.25, where f1 is the effective focal length of the first lens, R1 is the curvature radius of the object side surface of the first lens, f34 is the combined focal length of the third lens and the fourth lens, f2 is the effective focal length of the second lens, EP01 is the distance along the optical axis from the object side end face of the lens barrel to the object side surface of the first spacer element, EP12 is the axial spacing distance between the first spacer element and the second spacer element, and ∑CP1 is the sum of the maximum thicknesses of all spacer elements between the first lens and the second lens along the optical axis.

[0005] According to an embodiment of the present application, the central thickness CT2 of the second lens, the central thickness CT1 of the first lens, the sum ∑CP1 of the maximum thicknesses of all spacer elements between the first lens and the second lens along the optical axis, the sum ∑CP2 of the maximum thicknesses of all spacer elements between the second lens and the third lens along the optical axis, and the axial spacing distance EP12 between the first spacer element and the second spacer element satisfy: 1.65 < CT2 / CT1 ≤ 3.00, 1.25 ≤ (∑CP1 + ∑CP2) / EP12 < 6.00.

[0006] According to an embodiment of this application, the inner diameter d0s of the object-side end face of the lens barrel, the inner diameter d3s of the object-side surface of the third spacer element, and the entrance pupil diameter EPD of the optical imaging lens satisfy: 1.45 ≤ d0s / d3s < 2.30, 2.50 <d0s / EPD<4.00。

[0007] According to an embodiment of this application, the plurality of spacers further includes a fourth spacer element disposed on the image side of the fourth lens and in contact with the image side of the fourth lens. The effective focal length f3 of the third lens, the effective focal length f4 of the fourth lens, the air gap T34 between the third lens and the fourth lens on the optical axis, the spacing distance EP23 between the second spacer element and the third spacer element along the optical axis, and the spacing distance EP34 between the third spacer element and the fourth spacer element along the optical axis satisfy: -8.10≤(f3+f4) / T34<-5.50, 10.45≤(EP23+EP34) / T34<15.20.

[0008] According to an embodiment of this application, the effective focal length f1 of the first lens and the inner diameter d1s of the object-side surface of the first spacer element satisfy: -1.30 <f1 / d1s<-0.50。

[0009] According to an embodiment of this application, the effective focal length f1 of the first lens, the effective focal length f of the optical imaging lens, the distance EP01 from the object-side end face of the lens barrel to the object-side surface of the first spacer element along the optical axis, and the center thickness CT1 of the first lens satisfy: -1.30 <f1 / f<-0.95,3.90<EP01 / CT1<7.40。

[0010] According to an embodiment of this application, the air gap T12 between the first lens and the second lens on the optical axis, the air gap T23 between the second lens and the third lens on the optical axis, the air gap T34 between the third lens and the fourth lens on the optical axis, the maximum height L of the lens barrel, the sum of the maximum thicknesses of all spacers between the first lens and the second lens along the optical axis direction ∑CP1, and the sum of the maximum thicknesses of all spacers between the second lens and the third lens along the optical axis direction ∑CP2 satisfy: 19.75≤(T12+T23) / T34<34.45, 2.40≤L / (∑CP1+∑CP2)<4.45.

[0011] According to an embodiment of this application, the inner diameter d0m of the image-side end face of the lens barrel, the effective focal length f of the optical imaging lens, and half of the maximum field of view (Semi-FOV) of the optical imaging lens satisfy: 3.40 <d0m / (f tan(Semi-FOV)<4.75.

[0012] According to an embodiment of the present application, the air gap T23 between the second lens and the third lens on the optical axis and the maximum value CP2max of the maximum thickness of all spacer elements between the second lens and the third lens along the optical axis direction satisfy: 0.80 < T23 / CP2max < 1.20.

[0013] According to an embodiment of the present application, the outer diameter D3m of the image side surface of the third spacer element and the inner diameter d3s of the object side surface of the third spacer element satisfy: 2.05 < D3m / d3s < 4.25.

[0014] According to an embodiment of the present application, the effective focal length f3 of the third lens, the effective focal length f of the optical imaging lens, and the effective focal length f4 of the fourth lens satisfy: 0.60 ≤ f3 / f ≤ 0.75, -1.55 < f4 / f3 < -1.30.

[0015] According to an embodiment of the present application, the aperture number FNO of the optical imaging lens and half of the maximum field angle Semi-FOV of the optical imaging lens satisfy: 2.35 < FNO / tan(Semi-FOV) < 2.80.

[0016] According to the technical solution of an embodiment of the present application, by reasonably distributing the lens optical power and the effective focal length f1 of the first lens and the curvature radius R1 of the object side surface satisfy 0.30 ≤ f1 / R1 < 0.70, and the combined focal length of the third lens and the fourth lens and the effective focal length f2 of the second lens satisfy 0.90 < f34 / f2 ≤ 1.25. Due to the constraints of the focal lengths of each lens and the limitations on the focal length and surface shape of the first lens, the first lens is thinner in the middle and thicker at the edges. If the thickness of its non-light-transmitting area is set improperly, it will cause the first lens to crack. The present application can constrain the thickness of the non-light-transmitting area of the first lens by constraining the distance relationship among EP01, EP12, and ∑CP1, thereby controlling the overall shape of the first lens and reducing the possibility of cracking of the first lens caused by stress concentration during the assembly (i.e., high-precision assembly and adjustment) process, improving the production yield and the post-assembly stability of the lens. Description of the Drawings

[0017] With reference to the accompanying drawings, through the following detailed description of non-limiting embodiments, other features, objects, and advantages of the present application will become more apparent. In the drawings:

[0018] Figure 1 Shows a local stress diagram of the optical imaging lens when f1 / R1 = 0.57, f34 / f2 = 0.95, and EP01 / (EP12 + ∑CP1) = 0.35; Figure 2The local stress diagram of the optical imaging lens is shown when f1 / R1=0.57, f34 / f2=0.95 and EP01 / (EP12+∑CP1)=1.1; Figure 3 The local stress diagram of the optical imaging lens is shown when f1 / R1=0.57, f34 / f2=0.95 and EP01 / (EP12+∑CP1)=1.5; Figure 4 A schematic diagram showing the dimensions of an optical imaging lens according to this application is provided. Figure 5 A schematic diagram of multiple lenses of the optical imaging lens of Embodiment 1 provided in this application is shown; Figure 6 Example 1 is shown. A schematic diagram of the structure of an optical imaging lens; Figure 7 Example 1 is shown. Schematic diagram of the optical imaging lens of Figure 2; Figure 8 Example 1 is shown. A schematic diagram of the structure of the optical imaging lens of the 3rd generation; Figure 9 A schematic diagram of the on-axis chromatic aberration curve of the optical imaging lens of Embodiment 1 is shown; Figure 10 A schematic diagram of the astigmatism curve of the optical imaging lens of Embodiment 1 is shown. Figure 11 A schematic diagram of the magnification chromatic aberration curve of the optical imaging lens of Embodiment 1 is shown; Figure 12 A schematic diagram of multiple lenses of the optical imaging lens of Embodiment 2 provided in this application is shown; Figure 13 Example 2 is shown. A schematic diagram of the structure of an optical imaging lens; Figure 14 Example 2 is shown. Schematic diagram of the optical imaging lens of Figure 2; Figure 15 Example 2 is shown. A schematic diagram of the structure of the optical imaging lens of the 3rd generation; Figure 16 A schematic diagram of the on-axis chromatic aberration curve of the optical imaging lens of Embodiment 2 is shown; Figure 17 A schematic diagram of the astigmatism curve of the optical imaging lens of Embodiment 2 is shown; Figure 18 A schematic diagram of the magnification chromatic aberration curve of the optical imaging lens in Embodiment 2 is shown; Figure 19 A schematic diagram of multiple lenses of the optical imaging lens of Embodiment 3 provided in this application is shown; Figure 20 Example 3 is shown. A schematic diagram of the structure of an optical imaging lens; Figure 21 Example 3 is shown. Schematic diagram of the optical imaging lens of Figure 2; Figure 22 Example 3 is shown. A schematic diagram of the structure of the optical imaging lens of the 3rd generation; Figure 23 A schematic diagram of the on-axis chromatic aberration curve of the optical imaging lens of Embodiment 3 is shown; Figure 24 A schematic diagram of the astigmatism curve of the optical imaging lens of Embodiment 3 is shown; Figure 25 A schematic diagram of the magnification chromatic aberration curve of the optical imaging lens of Embodiment 3 is shown. Detailed Implementation

[0019] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0020] It should be noted that in this specification, the terms "first," "second," etc., are used only to distinguish one feature from another and do not imply any limitation on the feature.

[0021] 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 strictly to scale.

[0022] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0023] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having a meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formalized sense, unless expressly so specified herein.

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] The features, principles and other aspects of this application are described in detail below.

[0026] During the assembly process of an optical imaging lens, the lens is prone to cracking due to stress concentration, resulting in a low production yield of the optical imaging lens and poor long-term stability of the optical imaging lens. Therefore, an embodiment of the present application provides an optical imaging lens. By reasonably planning the thickness of the non-light-passing regions of the first lens and the second lens and the proportional combination between spacer elements, the problem of lens cracking is at least partially solved while ensuring clear imaging of the optical imaging lens. The optical imaging lens provided in the present application is applicable to large apertures. The optical imaging lens sequentially includes, from the object side to the image side along the optical axis: a first lens with a negative optical power, a second lens with a positive optical power, a third lens with a positive optical power, and a fourth lens with a negative optical power. The object side surface of the first lens is concave, and the image side surface of the first lens is concave; the object side surface of the second lens is convex, and the image side surface of the second lens is convex; the object side surface of the third lens is convex, and the image side surface of the third lens is convex; the object side surface of the fourth lens is concave, and the image side surface of the fourth lens is convex; there is an axial air gap between each adjacent lens among the first lens, the second lens, the third lens, and the fourth lens, and the axial air gap between the third lens and the fourth lens is the minimum value among the axial air gaps between each adjacent lens. The optical imaging lens further includes a plurality of spacer elements, and the plurality of spacer elements include a first spacer element, a second spacer element, and a third spacer element. The first spacer element is placed on the image side of the first lens and contacts the image side surface of the first lens; the second spacer element is placed on the image side of the second lens and contacts the image side surface of the second lens; the third spacer element is placed on the image side of the third lens and contacts the image side surface of the third lens; the plurality of spacer elements, the first lens, the second lens, the third lens, and the fourth lens are placed in a lens barrel, 0.30 ≤ f1 / R1 < 0.70, 0.90 < f34 / f2 ≤ 1.25, 0.50 < EP01 / (EP12 + ∑CP1) < 1.25, f1 is the effective focal length of the first lens, R1 is the curvature radius of the object side surface of the first lens, f34 is the combined focal length of the third lens and the fourth lens, f2 is the effective focal length of the second lens, EP01 is the distance along the optical axis from the object side end face of the lens barrel to the object side surface of the first spacer element, EP12 is the axial spacing distance between the first spacer element and the second spacer element, and ∑CP1 is the sum of the maximum thicknesses of all spacer elements along the optical axis between the first lens and the second lens.

[0027] Figure 1 Shows a local stress diagram of the optical imaging lens when f1 / R1 = 0.57, f34 / f2 = 0.95, and EP01 / (EP12 + ∑CP1) = 0.35; Figure 2 Shows a local stress diagram of the optical imaging lens when f1 / R1 = 0.57, f34 / f2 = 0.95, and EP01 / (EP12 + ∑CP1) = 1.1; Figure 3The local stress diagram of the optical imaging lens when f1 / R1 = 0.57, f34 / f2 = 0.95, and EP01 / (EP12 + ∑CP1) = 1.5 is shown.

[0028] As Figure 1 shown, the local stress was obtained under the conditions of f1 / R1 = 0.57, f34 / f2 = 0.95, and EP01 / (EP12 + ∑CP1) = 0.35, and the fitting clearance between the first lens and the lens barrel was 0.005 mm. After assembly, the maximum local stress of the first lens = 5.66 MP, the local stress is relatively large, the risk of cracking of the first lens during the assembly process is relatively large, and the assembly stability is relatively poor.

[0029] As Figure 2 shown, the local stress was obtained under the conditions of f1 / R1 = 0.57, f34 / f2 = 0.95, and EP01 / (EP12 + ∑CP1) = 1.1, and the fitting clearance between the first lens and the lens barrel was 0.005 mm. After assembly, the maximum local stress of the first lens is less than 3 MP, there is no risk of cracking of the first lens during the assembly process, and the stability is relatively good.

[0030] As Figure 3 shown, the local stress was obtained under the conditions of f1 / R1 = 0.57, f34 / f2 = 0.95, and EP01 / (EP12 + ∑CP1) = 1.5, and the fitting clearance between the first lens and the lens barrel was 0.005 mm. After assembly, the maximum local stress of the first lens = 5.03 MP, there is a risk of cracking of the first lens during the assembly process, and the stability is relatively poor.

[0031] The effective focal length of the first lens and the curvature radius of the object side surface satisfy 0.30 ≤ f1 / R1 < 0.70, and the combined focal length f34 of the third lens and the fourth lens and the effective focal length f2 of the second lens satisfy 0.90 < f34 / f2 ≤ 1.25. Due to the limitations of the focal length of each lens on the focal length and surface shape of the first lens, the first lens is thinner in the middle and thicker at the edges as a whole. If the thickness of its non-light-passing area is set improperly, it will cause cracking of the first lens. Based on Figure 1-3 the visible local stress diagram, the distance relationship among the light-passing constraints EP01, EP12, and ∑CP1 in this application can constrain the thickness of the non-light-passing area of the first lens, and further control the overall shape of the first lens, at least partially avoiding the cracking problem of the first lens caused by excessive stress during the assembly process, and improving the production yield and the long-term stability of the lens.

[0032] In the present application, ∑CP1 is the sum of the maximum thicknesses of all the spacer elements between the first lens and the second lens along the optical axis direction. For example, when all the spacer elements between the first lens and the second lens include not only the first spacer element, but also the first auxiliary spacer element and the first secondary auxiliary spacer element, the maximum thickness of the first spacer element along the optical axis direction is denoted as CP1, the maximum thickness of the first auxiliary spacer element along the optical axis direction is denoted as CP1b, and the maximum thickness of the first secondary auxiliary spacer element along the optical axis direction is denoted as CP1c. Then, ∑CP1 = CP1 + CP1b + CP1c. For specific details, please refer to Embodiment 1 below. Another example, when all the spacer elements between the first lens and the second lens include not only the first spacer element, but also the first auxiliary spacer element, then ∑CP1 = CP1 + CP1b. ∑CP2 is the sum of the maximum thicknesses of all the spacer elements between the second lens and the third lens along the optical axis direction, and by analogy with ∑CP1.

[0033] In an exemplary embodiment, the distance TD on the optical axis from the object side surface of the first lens to the image side surface of the fourth lens, the effective focal length f of the optical imaging lens, and half of the maximum field angle Semi - FOV of the optical imaging lens satisfy: 1.55 < TD / f tan(Semi - FOV) ≤ 1.85. By constraining the above conditional expressions within the range, this embodiment is beneficial for controlling the overall optical length of the lens and achieving the required field of view size, reducing the vignetting effect of marginal rays, and improving the brightness uniformity of the full - field imaging.

[0034] In an exemplary embodiment, the central thickness CT2 of the second lens, the central thickness CT1 of the first lens, the sum ∑CP1 of the maximum thicknesses of all the spacer elements between the first lens and the second lens along the optical axis direction, the sum ∑CP2 of the maximum thicknesses of all the spacer elements between the second lens and the third lens along the optical axis direction, and the axial spacing distance EP12 between the first spacer element and the second spacer element satisfy: 1.65 < CT2 / CT1 ≤ 3.00, 1.25 ≤ (∑CP1 + ∑CP2) / EP12 < 6.00. Since the on - axis air gap between the first lens and the second lens is relatively large and the central thickness of the second lens is greater than that of the first lens, by controlling the reasonable proportional relationship among ∑CP1, ∑CP2, and EP12, the spacer elements between the first lens and the second lens can effectively bear the weight of the lens and external forces, preventing the first lens and the second lens from shifting or deforming when the lens is subjected to vibrations, impacts, etc., thus ensuring the structural stability of the lens.

[0035] In an exemplary embodiment, the inner diameter d0s of the object-side end face of the lens barrel, the inner diameter d3s of the object-side face of the third spacer element, and the entrance pupil diameter EPD of the optical imaging lens satisfy: 1.45 ≤ d0s / d3s < 2.30, 2.50 < d0s / EPD < 4.00. By restricting the proportional relationship among the light-passing aperture d0s of the lens barrel, the light-passing aperture d3s of the rear lens group, and the entrance pupil diameter, it is beneficial to optimize the light-passing path of marginal rays, enabling the lens to achieve a more compact overall optical length layout and higher structural assembly stability at a large aperture, while taking into account the aberration correction and light-passing amount requirements for imaging at a large aperture.

[0036] In an exemplary embodiment, the plurality of spacer elements further includes a fourth spacer element disposed on the image side of the fourth lens and in contact with the image-side face of the fourth lens. The effective focal length f3 of the third lens, the effective focal length f4 of the fourth lens, the air gap T34 between the third lens and the fourth lens on the optical axis, the spacing distance EP23 between the second spacer element and the third spacer element along the optical axis, and the spacing distance EP34 between the third spacer element and the fourth spacer element along the optical axis satisfy: -8.10 ≤ (f3 + f4) / T34 < -5.50, 10.45 ≤ (EP23 + EP34) / T34 < 15.20. The distribution of the optical powers of the third lens and the fourth lens results in a relatively small on-axis gap between these two lenses. The above proportional relationship defines the relationship between the axial distances of the second spacer element, the third spacer element, and the fourth spacer element and the air gap between the third lens and the fourth lens, enabling the axial distances of the aforementioned three spacer elements and the air gap between the lenses to form a structurally cooperative relationship of mutual constraint and mutual limitation, avoiding light-axis deviation and out-of-control spacing distances caused by minor offsets of the spacer elements (such as machining / assembly tolerances) during the assembly process, and improving the assembly yield of the optical lens.

[0037] In an exemplary embodiment, the effective focal length f1 of the first lens and the inner diameter d1s of the object-side face of the first spacer element satisfy: -1.30 < f1 / d1s < -0.50. This embodiment helps to ensure that the light incident on the lens barrel can be effectively received by the second lens and continue to propagate after being refracted and diverged by the first lens, thus ensuring the coherence of the imaging optical path.

[0038] In an exemplary embodiment, the effective focal length f of the optical imaging lens and the entrance pupil diameter EPD of the optical imaging lens satisfy: 1.75 < f / EPD < 1.85. By restricting the effective focal length and the entrance pupil diameter of the optical imaging lens within this range, it is beneficial for the lens to have sufficient light-passing amount to capture clear images when used at night.

[0039] In an exemplary embodiment, the effective focal length f1 of the first lens, the effective focal length f of the optical imaging lens, the distance EP01 from the object-side end face of the lens barrel to the object-side surface of the first spacer element along the optical axis, and the central thickness CT1 of the first lens satisfy: -1.30 < f1 / f < -0.95, 3.90 < EP01 / CT1 < 7.40. By constraining the focal length ratio and thickness ratio of the first lens, this embodiment can facilitate better stability of the first lens in the face of different environmental conditions, such as temperature changes and mechanical vibrations, and reduce optical performance changes and imaging deviations caused by thermal expansion and contraction.

[0040] In an exemplary embodiment, the air gap T12 between the first lens and the second lens on the optical axis, the air gap T23 between the second lens and the third lens on the optical axis, the air gap T34 between the third lens and the fourth lens on the optical axis, the maximum height L of the lens barrel, the sum ∑CP1 of the maximum thicknesses of all spacer elements along the optical axis between the first lens and the second lens, and the sum ∑CP2 of the maximum thicknesses of all spacer elements along the optical axis between the second lens and the third lens satisfy: 19.75 ≤ (T12 + T23) / T34 < 34.45, 2.40 ≤ L / (∑CP1 + ∑CP2) < 4.45. In this embodiment, the relatively large air gaps between adjacent lenses of the first lens, the second lens, and the third lens can effectively correct aberrations, and at the same time, setting reasonable spacer element thicknesses between the lenses is beneficial for stable bearing between the lenses.

[0041] In an exemplary embodiment, the inner diameter d0m of the image-side end face of the lens barrel, the effective focal length f of the optical imaging lens, and half of the maximum field angle Semi-FOV of the optical imaging lens satisfy: 3.40 < d0m / (f tan(Semi-FOV) < 4.75. By constraining the inner diameter of the image-side end face of the lens barrel through the above conditional formula, it is avoided that the inner diameter of the lens barrel is too small to intercept the effective light rays hitting the image plane or too large to cause excessive light rays to exit and hit the imaging plane, affecting the final imaging quality.

[0042] In an exemplary embodiment, the air gap T23 between the second lens and the third lens on the optical axis and the maximum value CP2max of the maximum thicknesses of all spacer elements along the optical axis between the second lens and the third lens satisfy: 0.80 < T23 / CP2max < 1.20. By constraining the above conditional formula, the ratio of the air gap between the second lens and the third lens to the thickness of the spacer element is reasonably set, ensuring that when the lens is affected by external factors such as mechanical vibrations, shocks, and temperature changes, the relative positions between the second lens and the third lens and the structure of the lens are less likely to change, and better optical performance can be maintained.

[0043] In an exemplary embodiment, the outer diameter D3m of the image side of the third spacer element and the inner diameter d3s of the object side of the third spacer element satisfy: 2.05 < D3m / d3s < 4.25. This embodiment constrains the light-blocking effective annular surface of the third spacer element by restricting the ratio of the outer diameter of the image side to the inner diameter of the object side of the third spacer element, which is beneficial for finally absorbing the excess light at the edge and reducing the risk of stray light.

[0044] In an exemplary embodiment, the effective focal length f3 of the third lens, the effective focal length f of the optical imaging lens, and the effective focal length f4 of the fourth lens satisfy: 0.60 ≤ f3 / f ≤ 0.75, -1.55 < f4 / f3 < -1.30. By constraining the above conditional expressions, this embodiment helps to synergistically allocate the contributions of the third lens and the fourth lens in the lens to the convergence or divergence of light, optimize the incident angle and deflection state of light passing through the third lens and the fourth lens, avoid sudden changes in light deflection, scattering at the lens interface, and generation of stray light, and at the same time systematically correct aberrations, improving the imaging stability and imaging quality of the lens.

[0045] In an exemplary embodiment, the f-number FNO of the optical imaging lens and half of the maximum field angle Semi-FOV of the optical imaging lens satisfy: 2.35 < FNO / tan(Semi-FOV) < 2.80. This embodiment indirectly constrains the f-number through the above value range, ensuring that the lens has an appropriate light input while satisfying a certain imaging range (determined by the field angle), so as to obtain a clear and bright image.

[0046] In an exemplary embodiment, the combined focal length f34 of the third lens and the fourth lens and the effective focal length f of the optical imaging lens satisfy: 1.65 ≤ f34 / f ≤ 2.26. By restricting the ratio of the combined focal length of the third lens and the fourth lens to the effective focal length of the optical imaging lens, it is beneficial for the correction of aberrations and the improvement of imaging quality.

[0047] The optical imaging lens in the present application employs four lenses. In the present application, at least one of the mirror surfaces of the multiple lenses can be an aspherical mirror surface. The characteristics of an aspherical lens are that the curvature continuously changes from the center of the lens to the periphery of the lens. Different from a spherical lens with a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has better curvature radius characteristics and has the advantages of improving distortion aberration and astigmatism aberration. After using an aspherical lens, it is possible to eliminate the aberrations that occur during imaging as much as possible, thereby improving the imaging quality.

[0048] Figure 4 A schematic diagram of the dimension marking of an optical imaging lens of the present application is shown. Figure 4The inner diameter d0s of the object-side end face of the lens barrel, the inner diameter d1s of the object-side surface of the first spacer element, the inner diameter d3s of the object-side surface of the third spacer element, the outer diameter D3m of the image-side surface of the third spacer element, the inner diameter d0m of the image-side end face of the lens barrel, the distance EP01 from the object-side end face of the lens barrel to the object-side surface of the first spacer element along the optical axis, the spacing distance EP12 between the first and second spacer elements along the optical axis, the spacing distance EP23 between the second and third spacer elements along the optical axis, the spacing distance EP34 between the third and fourth spacer elements along the optical axis, and the maximum thickness CP2 of the second spacer element along the optical axis between the second and third lenses are indicated in the figures to clearly and intuitively explain the meaning of these parameters. To facilitate the description of the optical imaging lens and the specific lens shape, these parameters will not be shown in the accompanying drawings when describing specific embodiments.

[0049] The following description, with reference to the accompanying drawings, further illustrates examples of specific surface shapes and parameters of imaging lenses applicable to the above embodiments. It should be noted that Embodiment 1 is included in the following Embodiment 1. 1. Example 1 2. Example 1 Three examples in 3, Example 2 contains Example 2. 1. Example 2 2. Example 2 Three examples are given in Example 3, with Example 3 existing in Example 3. 1. Example 3 2. Example 3 Three examples of 3. In the three examples of the same embodiment, the first to fourth lenses of the optical imaging lens have the same parameters such as radius of curvature, center thickness and aspherical higher-order coefficients, but the structural parameters are different.

[0050] 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.

[0051] Example 1 The following is for reference Figures 5 to 11 This application describes an optical imaging lens according to Embodiment 1. Figure 5 A schematic diagram of the optical imaging lens of Embodiment 1 provided in this application is shown. Figure 6 Example 1 is shown. A schematic diagram of the structure of an optical imaging lens, 1. Figure 7 Example 1 is shown. A schematic diagram of the optical imaging lens of Figure 2. Figure 8 Example 1 is shown. A schematic diagram of the optical imaging lens of the 3.

[0052] like Figure 5 As shown, the optical imaging lens includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4 arranged sequentially along the optical axis from the object side to the image side.

[0053] The first lens E1 has negative optical power, and its object-side surface S1 and image-side surface S2 are both concave. The second lens E2 has positive optical power, and its object-side surface S3 and image-side surface S4 are both convex. The third lens E3 has positive optical power, and its object-side surface S5 and image-side surface S6 are both convex. The fourth lens E4 has negative optical power, and its object-side surface S7 and image-side surface S8 are both convex.

[0054] like Figure 5 As shown, the optical imaging lens may also include an aperture stop STO, which is disposed, for example, between the image side of the first lens E1 and the object side of the second lens E2.

[0055] like Figure 5 As shown, the optical imaging lens may also include a filter, which includes an object-side surface S9 and an image-side surface S10. The filter, for example, is an infrared cut-off filter, a thin, flat optical element used to filter near-infrared light and ensure color reproduction. After passing through multiple lenses and filters in sequence, light finally forms a clear image on the imaging plane S11. The imaging plane S11 of the optical imaging lens is, for example, the photosensitive surface of a sensor (CMOS / CCD).

[0056] like Figure 5 and 6 As shown, there is an on-axis air gap between each adjacent lens in the first lens E1, the second lens E2, the third lens E3 and the fourth lens E4, and the on-axis air gap between the third lens E3 and the fourth lens E4 is the minimum value among the on-axis air gaps between each adjacent lens.

[0057] like Figure 6 As shown, Example 1 The optical imaging lens of 1 includes Figure 5In addition to the various lenses, diaphragms, filters, and imaging planes shown, there are also a plurality of spacer elements, which include a first spacer element P1, a first auxiliary spacer element P1b, a first sub-auxiliary spacer element P1c, a second spacer element P2, a second auxiliary spacer element P2b, a third spacer element P3, and a fourth spacer element P4. The first auxiliary spacer element P1b is placed on the image side of the first spacer element P1 and is in contact with the image-side surface of the first spacer element P1. The first sub-auxiliary spacer element P1c is placed on the image side of the first auxiliary spacer element P1b and is in contact with the image-side surface of the first auxiliary spacer element P1b. The second auxiliary spacer element P2b is placed on the image side of the second spacer element P2 and is in contact with the image-side surface of the second spacer element P2.

[0058] As Figure 6 shown, a plurality of spacer elements, a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4 are placed inside the lens barrel P0.

[0059] In various embodiments of the optical imaging lens, 0.30 ≤ f1 / R1 < 0.70, 0.90 < f34 / f2 ≤ 1.25, 0.50 < EP01 / (EP12 + ∑CP1) < 1.25, where f1 is the effective focal length of the first lens, R1 is the radius of curvature of the object-side surface of the first lens, f34 is the combined focal length of the third lens and the fourth lens, f2 is the effective focal length of the second lens, EP01 is the distance from the object-side end face of the lens barrel to the object-side surface of the first spacer element along the optical axis direction, EP12 is the distance between the first spacer element and the second spacer element along the optical axis direction, and ∑CP1 is the sum of the maximum thicknesses of all spacer elements between the first lens and the second lens along the optical axis direction. In this embodiment, ∑CP1 = CP1 + CP1b + CP1c, where the maximum thickness of the first spacer element along the optical axis direction is denoted as CP1, the maximum thickness of the first auxiliary spacer element along the optical axis direction is denoted as CP1b, and the maximum thickness of the first sub-auxiliary spacer element along the optical axis direction is denoted as CP1c.

[0060] As Figure 7 shown, it is the structural schematic diagram of the optical imaging lens of Embodiment 1 2. As Figure 8 shown, it is the structural schematic diagram of the optical imaging lens of Embodiment 1 3. The optical imaging lenses of Embodiment 1 2 and Embodiments 1-3 have the same curvature radii, center thicknesses, etc. of the first lens to the fourth lens and the aspheric high-order term coefficients as those of the optical imaging lens of Embodiment 1 1, but there are differences in the structural parameters (please refer to Table 8 for details). In addition, for example, Embodiment 1 The shape, size, etc. of the lens barrel P0 in Example 2 and Examples 1-3 may differ from those of the lens barrel P0 in Examples 1-1. Regarding Example 1... The optical imaging lenses of Examples 2 and 1-3 can be referenced from Example 1. The relevant descriptions in section 1 will not be repeated here.

[0061] Table 1 shows the basic structural parameters of the optical imaging lens in Embodiment 1, where the units for radius of curvature and center thickness / gap are millimeters (mm).

[0062] Table 1

[0063] In this embodiment, the object-side surface S1 of the first lens E1, the image-side surface S2 of the first lens E1, the object-side surface S5 of the third lens E3, the image-side surface S6 of the third lens E3, the object-side surface S7 of the fourth lens E4, and the image-side surface S8 of the fourth lens E4 are aspherical surfaces. The surface shape of the aspherical lens can be limited by, but is not limited to, the following aspherical formula: (Formula 1) in, For an aspherical surface along the optical axis at a height of h When the position is such that the distance from the vertex of the non-spherical surface is the sag; c For the paraxial curvature of an aspherical surface, c =1 / R (i.e., paraxial curvature) c (The reciprocal of the radius of curvature R in Table 1 above). k The conic coefficient; Ai Is it an aspherical first i -th order correction coefficients. Table 2 below shows the higher-order coefficients A4, A6, A8, A10, and A12 that can be used for aspherical surfaces in this embodiment.

[0064] Table 2

[0065] Figure 9 A schematic diagram of the on-axis chromatic aberration curve of the optical imaging lens of Embodiment 1 is shown. The on-axis chromatic aberration curve represents the deviation of the focal point of light of different wavelengths after passing through the optical imaging lens. Figure 10 A schematic diagram of the astigmatism curve of the optical imaging lens of Embodiment 1 is shown. The astigmatism curve represents the curvature of the meridional image plane and the sagittal image plane. Figure 11 A schematic diagram of the chromatic aberration curve of the optical imaging lens of Embodiment 1 is shown. The chromatic aberration curve represents the deviation of different image heights on the imaging plane after light passes through the lens.

[0066] according to Figure 9-11As can be seen, the optical imaging lens given in Example 1 can achieve good imaging quality.

[0067] Example 2 The following is for reference Figures 12 to 18 The optical imaging lens of Embodiment 2 of this application is described. Figure 12 A schematic diagram of the optical imaging lens of Embodiment 2 provided in this application is shown. Figure 13 Example 2 is shown. A schematic diagram of the structure of an optical imaging lens, 1. Figure 14 Example 2 is shown. A schematic diagram of the optical imaging lens of Figure 2. Figure 15 Example 2 is shown. A schematic diagram of the optical imaging lens of the 3.

[0068] like Figure 12 As shown, the optical imaging lens includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4 arranged sequentially along the optical axis from the object side to the image side. The first lens E1 has negative optical power, and its object-side surface S1 and image-side surface S2 are both concave. The second lens E2 has positive optical power, and its object-side surface S3 and image-side surface S4 are both convex. The third lens E3 has positive optical power, its object-side surface S5 and image-side surface S6 are both convex. The fourth lens E4 has negative optical power, its object-side surface S7 is concave, and its image-side surface S8 is convex.

[0069] like Figure 12 As shown, the optical imaging lens may also include an aperture stop STO, which is disposed, for example, between the image side of the first lens E1 and the object side of the second lens E2.

[0070] like Figure 12 As shown, the optical imaging lens may also include a filter, which includes an object-side surface S9 and an image-side surface S10. Please refer to the description of Embodiment 1 above for details about the filter. After light passes through multiple lenses and the filter of the optical imaging lens in sequence, a clear image is finally formed on the imaging plane S11 (please refer to the description of Embodiment 1 above).

[0071] like Figure 12 and 13As shown, each adjacent lens in the first lens E1, second lens E2, third lens E3, and fourth lens E4 has an on-axis air gap, and the on-axis air gap between the third lens E3 and the fourth lens E4 is the minimum value among the on-axis air gaps between adjacent lenses. For details regarding the on-axis air gaps in the first lens E1, second lens E2, third lens E3, and fourth lens E4, please refer to the description in Embodiment 1 above.

[0072] like Figure 13 As shown, Example 2 1. Optical imaging lens, including Figure 12 In addition to the lenses, apertures, filters, and imaging planes shown, the system also includes multiple spacer elements, including a first spacer element P1, a first auxiliary spacer element P1b, a second spacer element P2, a second auxiliary spacer element P2b, a third spacer element P3, and a fourth spacer element P4. The first auxiliary spacer element P1b is positioned on the image side of the first spacer element P1 and contacts the image side of the first spacer element P1; the second auxiliary spacer element P2b is positioned on the image side of the second spacer element P2 and contacts the image side of the second spacer element P2. Please refer to the description of Embodiment 1 above for details regarding the multiple spacer elements.

[0073] like Figure 13 As shown, multiple spacer elements, a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4 are placed inside the lens barrel P0.

[0074] like Figure 14 As shown, this is Example 2. A schematic diagram of the optical imaging lens in Figure 2. Figure 15 As shown, this is Example 2. A schematic diagram of the optical imaging lens of Figure 3. Example 2 2 and Example 2 The optical imaging lens of 3 is the same as that of Example 2. The first to fourth lenses of the optical imaging lens in embodiment 1 have the same parameters such as radius of curvature, center thickness, and aspherical higher-order coefficients, but their structural parameters differ (see Table 8 for details). In addition, for example, in embodiment 2... Lens tube P0 of Example 2 and Example 2 The shape and size of the lens barrel P0 in Example 3 may also differ from those in Example 2-1. Regarding Example 2... 2 and Example 2 The optical imaging lens of 3 can be referred to in Example 2. The relevant descriptions in section 1 will not be repeated here.

[0075] Table 3 shows the basic structural parameters of the optical imaging lens in Embodiment 2, where the units for radius of curvature and center thickness / gap are millimeters (mm).

[0076] Table 3

[0077] In this embodiment, the object-side surface S1, the image-side surface S2, the object-side surface S5, the image-side surface S6, the object-side surface S7, and the image-side surface S8 of the fourth lens E4 are aspherical surfaces. The surface shape of the aspherical lens can be defined using, but is not limited to, Formula 1 (Aspherical Formula) in Embodiment 1. Table 4 below shows the higher-order coefficients A4, A6, A8, A10, A12, A14, and A16 that can be used for the aspherical surfaces in this embodiment.

[0078] Table 4

[0079] Figure 16 A schematic diagram of the on-axis chromatic aberration curve of the optical imaging lens of Embodiment 2 is shown. The on-axis chromatic aberration curve represents the deviation of the focal point of light of different wavelengths after passing through the optical imaging lens. Figure 17 A schematic diagram of the astigmatism curve of the optical imaging lens of Embodiment 2 is shown. The astigmatism curve represents the curvature of the meridional image plane and the sagittal image plane. Figure 18 A schematic diagram of the chromatic aberration curve of the optical imaging lens of Embodiment 2 is shown. The chromatic aberration curve represents the deviation of different image heights on the imaging plane after light passes through the lens.

[0080] according to Figure 16-18 It can be seen that the optical imaging lens given in Example 2 can achieve good imaging quality.

[0081] Example 3 The following is for reference Figures 19 to 25 The optical imaging lens of Embodiment 3 of this application is described. Figure 19 A schematic diagram of the optical imaging lens of Embodiment 3 provided in this application is shown. Figure 20 Example 3 is shown. A schematic diagram of the structure of an optical imaging lens, 1. Figure 21 Example 3 is shown. A schematic diagram of the optical imaging lens of Figure 2. Figure 22 Example 3 is shown. A schematic diagram of the optical imaging lens of the 3.

[0082] like Figure 19As shown, the optical imaging lens includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4 arranged sequentially along the optical axis from the object side to the image side. The first lens E1 has negative optical power, and its object-side surface S1 and image-side surface S2 are both concave. The second lens E2 has positive optical power, and its object-side surface S3 and image-side surface S4 are both convex. The third lens E3 has positive optical power, its object-side surface S5 and image-side surface S6 are both convex. The fourth lens E4 has negative optical power, its object-side surface S7 is concave, and its image-side surface S8 is convex.

[0083] like Figure 19 As shown, the optical imaging lens may also include an aperture stop STO, which is disposed, for example, between the image side of the first lens E1 and the object side of the second lens E2.

[0084] like Figure 19 As shown, the optical imaging lens may also include a filter, which includes an object-side surface S9 and an image-side surface S10. Please refer to the description of Embodiment 1 above for details about the filter. After light passes through multiple lenses and the filter of the optical imaging lens in sequence, a clear image is finally formed on the imaging plane S11 (please refer to the description of Embodiment 1 above).

[0085] like Figure 19 and 20 As shown, there is an on-axis air gap between each adjacent lens in the first lens E1, the second lens E2, the third lens E3 and the fourth lens E4, and the on-axis air gap between the third lens E3 and the fourth lens E4 is the minimum value among the on-axis air gaps between each adjacent lens.

[0086] like Figure 20 As shown, Example 3 1. Optical imaging lens, including Figure 19 In addition to the lenses, apertures, filters, and imaging planes shown, the system also includes multiple spacer elements, including a first spacer element P1, a first auxiliary spacer element P1b, a second spacer element P2, a second auxiliary spacer element P2b, a third spacer element P3, and a fourth spacer element P4. The first auxiliary spacer element P1b is positioned on the image side of the first spacer element P1 and contacts the image side of the first spacer element P1; the second auxiliary spacer element P2b is positioned on the image side of the second spacer element P2 and contacts the image side of the second spacer element P2. Please refer to the description of Embodiment 1 above for details regarding the multiple spacer elements.

[0087] like Figure 20 As shown, multiple spacer elements, a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4 are placed inside the lens barrel P0.

[0088] like Figure 21 As shown, this is Example 3. A schematic diagram of the optical imaging lens in Figure 2. Figure 22 As shown, this is Example 3. Schematic diagram of the optical imaging lens of Example 3. Example 2 and Example 3 The optical imaging lens of Example 3 is respectively compared with Example 3. The first to fourth lenses of the optical imaging lens 1 have the same parameters such as radius of curvature, center thickness, and aspherical higher-order coefficients, but their structural parameters differ (see Table 8 for details). In addition, for example, in Example 3... Lens tube P0 of Example 2 and Example 3 The shape and size of the lens barrel P0 in Example 3 may also differ from those in Example 3-1. Regarding Example 2... Example 2 and Example 3 The optical imaging lens of 3 can be referred to in Example 2. The relevant descriptions in section 1 will not be repeated here.

[0089] Table 5 shows the basic structural parameters of the optical imaging lens in Embodiment 3, where the units for radius of curvature and center thickness / gap are millimeters (mm).

[0090] Table 5

[0091] In this embodiment, the object-side surface S1 of the first lens E1, the image-side surface S2 of the first lens E1, the object-side surface S5 and image-side surface S6 of the third lens E3, the object-side surface S7 of the fourth lens E4, and the image-side surface S8 of the fourth lens E4 are aspherical surfaces. The surface shape of the aspherical lens can be defined using, but is not limited to, Formula 1 (Aspherical Formula) in Embodiment 1. Table 6 below shows the higher-order coefficients A4, A6, A8, A10, and A12 that can be used for the aspherical surfaces in this embodiment.

[0092] Table 6

[0093] Figure 23 A schematic diagram of the on-axis chromatic aberration curve of the optical imaging lens of Embodiment 3 is shown. The on-axis chromatic aberration curve represents the deviation of the focal point of light of different wavelengths after passing through the optical imaging lens. Figure 24 A schematic diagram of the astigmatism curve of the optical imaging lens of Embodiment 3 is shown. The astigmatism curve represents the curvature of the meridional image plane and the sagittal image plane. Figure 25 A schematic diagram of the chromatic aberration curve of the optical imaging lens of Embodiment 3 is shown. The chromatic aberration curve represents the deviation of different image heights on the imaging plane after light passes through the lens.

[0094] according to Figure 23-25 It can be seen that the optical imaging lens given in Example 3 can achieve good imaging quality.

[0095] Some optical parameters of the optical imaging lenses in Examples 1 to 3 are shown in Table 7. Structural data of the optical imaging lenses in Examples 1 to 3 are shown in Table 8 (unit: mm). The conditions satisfied by the optical imaging lenses in Examples 1 to 3 are shown in Table 9.

[0096] Table 7

[0097] Table 8

[0098] Table 9

[0099] Furthermore, this application also provides an electronic device that includes the optical imaging lens provided in any embodiment of this application. This electronic device may be, for example, a camera, a monitor, etc.

[0100] 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.

[0101] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of protection involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the concept of this application. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. An optical imaging lens, characterized in that, Along the optical axis from the object side to the image side, it sequentially includes: a first lens with negative optical power, a second lens with positive optical power, a third lens with positive optical power, and a fourth lens with negative optical power. Wherein, the object side of the first lens is concave, and the image side of the first lens is concave. The object-side surface of the second lens is convex, and the image-side surface of the second lens is also convex. The object-side surface of the third lens is convex, and the image-side surface of the third lens is convex. The object-side surface of the fourth lens is concave, and the image-side surface of the fourth lens is convex. Each of the first lens, the second lens, the third lens, and the fourth lens has an on-axis air gap between adjacent lenses, and the on-axis air gap between the third lens and the fourth lens is the minimum value among the on-axis air gaps between each adjacent lens. The optical imaging lens also includes multiple spacer elements, including a first spacer element, a second spacer element, and a third spacer element. The first spacer element is placed on the image side of the first lens and contacts the image side of the first lens; The second spacer element is placed on the image side of the second lens and contacts the image side of the second lens; The third spacer element is placed on the image side of the third lens and contacts the image side surface of the third lens; The plurality of spacer elements, the first lens, the second lens, the third lens, and the fourth lens are placed inside the lens barrel. Where 0.30≤f1 / R1<0.70, 0.90 <f34 / f2≤1.25,0.50<EP01 / (EP12+∑CP1)<1.25, f1 is the effective focal length of the first lens, R1 is the radius of curvature of the object side surface of the first lens, f34 is the combined focal length of the third lens and the fourth lens, f2 is the effective focal length of the second lens, EP01 is the distance from the object side end face of the lens barrel to the object side surface of the first spacer element along the optical axis, EP12 is the spacing distance between the first spacer element and the second spacer element along the optical axis, and ∑CP1 is the sum of the maximum thicknesses of all spacer elements between the first lens and the second lens along the optical axis.

2. The optical imaging lens according to claim 1, characterized in that, The center thickness CT2 of the second lens, the center thickness CT1 of the first lens, the sum of the maximum thicknesses of all spacers between the first and second lenses along the optical axis ∑CP1, the sum of the maximum thicknesses of all spacers between the second and third lenses along the optical axis ∑CP2, and the spacing EP12 between the first and second spacers along the optical axis satisfy: 1.65 <CT2 / CT1≤3.00,1.25≤(∑CP1+∑CP2) / EP12<6.00。 3. The optical imaging lens according to claim 1, characterized in that, The inner diameter d0s of the object-side end face of the lens barrel, the inner diameter d3s of the object-side surface of the third spacer element, and the entrance pupil diameter EPD of the optical imaging lens satisfy: 1.45 ≤ d0s / d3s < 2.30, 2.50 <d0s / EPD<4.00。 4. The optical imaging lens according to claim 1, characterized in that, The plurality of spacers also includes a fourth spacer element disposed on the image side of the fourth lens and in contact with the image side surface of the fourth lens. The effective focal length f3 of the third lens, the effective focal length f4 of the fourth lens, the air gap T34 between the third lens and the fourth lens on the optical axis, the spacing EP23 between the second spacer element and the third spacer element along the optical axis, and the spacing EP34 between the third spacer element and the fourth spacer element along the optical axis satisfy: -8.10≤(f3+f4) / T34<-5.50, 10.45≤(EP23+EP34) / T34<15.

20.

5. The optical imaging lens according to claim 1, characterized in that, The effective focal length f1 of the first lens and the inner diameter d1s of the object-side surface of the first spacer element satisfy: -1.30 <f1 / d1s<-0.50。 6. The optical imaging lens according to claim 1, characterized in that, The effective focal length f1 of the first lens, the effective focal length f of the optical imaging lens, the distance EP01 from the object-side end face of the lens barrel to the object-side surface of the first spacer element along the optical axis, and the center thickness CT1 of the first lens satisfy: -1.30 <f1 / f<-0.95,3.90<EP01 / CT1<7.40。 7. The optical imaging lens according to claim 1, characterized in that, The air gap T12 between the first lens and the second lens on the optical axis, the air gap T23 between the second lens and the third lens on the optical axis, the air gap T34 between the third lens and the fourth lens on the optical axis, the maximum height L of the lens barrel, the sum of the maximum thicknesses of all spacers between the first lens and the second lens along the optical axis ∑CP1, and the sum of the maximum thicknesses of all spacers between the second lens and the third lens along the optical axis ∑CP2 satisfy: 19.75≤(T12+T23) / T34<34.45, 2.40≤L / (∑CP1+∑CP2)<4.

45.

8. The optical imaging lens according to claim 1, characterized in that, The inner diameter d0m of the image-side end face of the lens barrel, the effective focal length f of the optical imaging lens, and half of the maximum field of view (Semi-FOV) of the optical imaging lens satisfy: 3.40 <d0m / (f tan(Semi-FOV))<4.

75.

9. The optical imaging lens according to claim 1, characterized in that, The air gap T23 between the second lens and the third lens on the optical axis, and the maximum value CP2max of the maximum thickness of all spacer elements between the second lens and the third lens along the optical axis, satisfy: 0.80 <T23 / CP2max<1.20。 10. The optical imaging lens according to claim 1, characterized in that, The outer diameter D3m of the image side of the third spacer element and the inner diameter d3s of the object side of the third spacer element satisfy: 2.05 <D3m / d3s<4.25。 11. The optical imaging lens according to claim 1, characterized in that, The effective focal length f3 of the third lens, the effective focal length f of the optical imaging lens, and the effective focal length f4 of the fourth lens satisfy: 0.60 ≤ f3 / f ≤ 0.75, -1.55 <f4 / f3<-1.30。 12. The optical imaging lens according to claim 1, characterized in that, The aperture number (FNO) of the optical imaging lens and half of the maximum field of view (Semi-FOV) of the optical imaging lens satisfy: 2.35 <FNO / tan(Semi-FOV)<2.80。

Images