An imaging lens

Abstract

The application discloses an imaging lens, which is composed of five lenses, at least one interval element is arranged between the first lens and the second lens and between the second lens and the third lens, the effective focal length f1 of the first lens, the effective focal length f2 of the second lens and the effective focal length f of the imaging lens satisfy 0.85<(f1+f2) / f<1.85, the sum of the maximum thicknesses of all interval elements between the first lens and the second lens along the optical axis direction is ∑CP1, the sum of the maximum thicknesses of all interval elements between the second lens and the third lens along the optical axis direction is ∑CP2, and the interval distance EP12 of the first interval element and the second interval element along the optical axis direction satisfies 0.90<(∑CP1+∑CP2) / EP12<1.95. The imaging lens can effectively inhibit stray light and improve imaging quality.

Description

Technical Field

[0001] This application generally relates to the field of optical equipment technology. More specifically, this application relates to an imaging lens. Background Technology

[0002] With the increasing demands for all-weather imaging and adaptability to complex environments in the security monitoring field, five-element lenses have been increasingly widely used in security scenarios due to their core advantages of controllable cost and miniaturized structure. Their miniaturization allows for flexible adaptation to the diverse installation needs of security front-end equipment, while their cost-effectiveness aligns with the practical demands of large-scale deployments in the security sector. The core value of security monitoring lies in clearly capturing target details to achieve identity recognition and event tracing, thus placing stringent requirements on image quality.

[0003] In existing five-element lens designs, due to the distribution of lens power, the air gaps between the first, second, and third lenses are often relatively large. Therefore, thicker spacer elements are needed in these gaps to block stray light. However, current technology lacks reasonable constraints on the thickness of the spacer elements and their spacing, making thick spacer elements prone to generating stray light. This results in blurred surveillance images, loss of critical details, and severely impacts the effectiveness of security monitoring.

[0004] In view of this, there is an urgent need to provide an imaging lens to reduce the risk of stray light in the imaging system, improve the imaging quality, and thus meet the application requirements of security monitoring for high-resolution imaging. Summary of the Invention

[0005] In order to at least solve one or more of the technical problems mentioned above, this application proposes the following imaging lens, which aims to effectively reduce the stray light risk of the imaging system and improve the imaging quality by reasonably constraining the optical power distribution of the lens and the thickness and spacing of the spacer elements, thereby meeting the application requirements of security monitoring for high-resolution imaging.

[0006] The imaging lens provided in this application includes a lens barrel and a lens group disposed in the lens barrel;

[0007] The lens group consists of five lenses, which are arranged sequentially from the object side to the image side along the optical axis as a first lens with negative optical power, a second lens with positive optical power, a third lens with positive optical power, a fourth lens with negative optical power, and a fifth lens with positive optical power. The first lens has a convex object-side surface and a concave image-side surface; the second lens has a concave object-side surface and a convex image-side surface; the third lens has both a convex object-side surface and an image-side surface; the fourth lens has a convex object-side surface and a concave image-side surface; and the fifth lens has both a convex object-side surface and an image-side surface. At least one spacer element is provided between the first lens and the second lens, and between the second lens and the third lens; the spacer element between the first lens and the second lens includes a first spacer element that contacts the image side of the first lens; the spacer element between the second lens and the third lens includes a second spacer element that contacts the image side of the second lens. The effective focal length f1 of the first lens, the effective focal length f2 of the second lens, and the effective focal length f of the imaging lens satisfy the following condition: 0.85 < (f1 + f2) / f < 1.85; The sum of the maximum thicknesses of all spacers between the first lens and the second lens along the optical axis, ∑CP1, the sum of the maximum thicknesses of all spacers between the second lens and the third lens along the optical axis, ∑CP2, and the spacing distance EP12 between the first spacer and the second spacer along the optical axis satisfy the following condition: 0.90 < (∑CP1 + ∑CP2) / EP12 < 1.95.

[0008] In some embodiments, the effective focal length f of the imaging lens and the entrance pupil diameter EPD of the imaging lens satisfy the following condition: 1.50 ≤ f / EPD ≤ 1.70; The minimum inner diameter d0smin of the object side surface of the lens barrel and the inner diameter d1s of the object side surface of the first spacer element satisfy the following condition: 1.15 <d0smin / d1s<1.55。

[0009] In some embodiments, the aperture number FNO of the imaging lens and half of the maximum field of view (Semi-FOV) of the imaging lens satisfy the following condition: 2.10 <FNO / TAN(Semi-FOV)<2.65。

[0010] In some embodiments, the spacing between the first spacer element and the second spacer element along the optical axis direction, EP12, the maximum thickness of the first spacer element along the optical axis direction, CP1, and the center thickness of the second lens, CT2, satisfy the following condition: 1.05 < (EP12 + CP1) / CT2 < 1.55.

[0011] In some embodiments, the effective half-aperture DT11 of the object-side surface of the first lens and the effective half-aperture DT21 of the object-side surface of the second lens satisfy the following condition: 1.60 <DT11 / DT21≤1.75; The effective focal length f1 of the first lens, the inner diameter d0s of the object-side end face of the lens barrel, and the inner diameter d1s of the object-side surface of the first spacer element satisfy the following condition: -7.85 <f1 / (d0s-d1s)<-4.95。

[0012] In some embodiments, a third spacer element is provided between the third lens and the fourth lens, and the third spacer element is in contact with the image side of the third lens; The spacing between the second spacer element and the third spacer element along the optical axis is EP23, the maximum thickness of the second spacer element along the optical axis is CP2, and the air gap T23 between the second lens and the third lens on the optical axis satisfies: 2.20 < (EP23 + CP2) / T23 < 3.25.

[0013] In some embodiments, a fourth spacer element is provided between the fourth lens and the fifth lens, and the fourth spacer element is in contact with the image side of the fourth lens; The effective focal length f4 of the fourth lens and the spacing EP34 between the third and fourth spacers along the optical axis satisfy the following condition: -2.65 <f4 / EP34<-2.00。

[0014] In some embodiments, the combined focal length f345 of the third lens, the fourth lens, and the fifth lens, 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 the following condition: 1.35 <f345 / (EP23+EP34)<3.25。

[0015] In some embodiments, 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, and the center thickness CT2 of the second lens satisfy the following condition: 2.25 < (T12 + T23) / CT2 < 2.45; 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 the condition: 0.35 < ∑CP1 / ∑CP2 < 0.60.

[0016] In some embodiments, the effective focal length f1 of the first lens and the radius of curvature R1 of the object-side surface of the first lens satisfy the following condition: -6.00 <f1 / R1<-4.30; The displacement SAG12 between the intersection of the image-side surface of the first lens on the optical axis and the vertex of the effective half-aperture of the image-side surface of the first lens, the displacement SAG21 between the intersection of the object-side surface of the second lens on the optical axis and the vertex of the effective half-aperture of the object-side surface of the second lens, and the sum of the maximum thicknesses of all spacers between the first lens and the second lens along the optical axis direction ∑CP1 satisfy: 1.85<(SAG12+|SAG21|) / ∑CP1<3.05.

[0017] In some embodiments, the displacement SAG11 between the intersection of the object-side surface of the first lens on the optical axis and the vertex of the effective half-aperture of the object-side surface of the first lens, and the spacing EP01 between the object-side end face of the lens barrel and the object-side surface of the first spacer element along the optical axis, satisfy: 0.60 <SAG11 / EP01<0.75。

[0018] In some embodiments, the radius of curvature R3 of the object-side surface of the second lens and the inner diameter d2s of the object-side surface of the second spacer element satisfy: -0.80 <R3 / d2s<-0.60。

[0019] With the imaging lens provided above, the ratio of the sum of the effective focal lengths of the first and second lenses to the total focal length of the imaging lens satisfies 0.85 < (f1 + f2) / f < 1.85, resulting in a reasonable distribution of optical power in the front lens group. However, a large air gap is formed between the first, second, and third lenses, requiring thicker spacer elements to accommodate the optical power distribution and structural assembly requirements. However, this thick spacer element structure is prone to stray light issues. Therefore, this application further controls the total thickness ∑CP1 of all spacer elements between the first and second lenses, the total thickness ∑CP2 of all spacer elements between the second and third lenses, and the distance EP12 between the first and second spacer elements along the optical axis to ensure that it satisfies 0.90 < (∑CP1 + ∑CP2) / EP12 < 1.95. By constraining this conditional expression, the matching relationship between the thickness and spacing of the spacer elements between the first lens, the second lens, and the third lens can be optimized. This reduces the risk of stray light caused by reflection of light at the corners of the second spacer element and the non-transparent area of ​​the second lens due to mismatch between the lens and the spacer element spacing. A reasonable spacer element thickness can block non-imaging light and suppress stray light generation, thereby improving the clarity of the image and meeting the application requirements of high-resolution imaging in the security monitoring field. Attached Figure Description

[0020] The above and other objects, features, and advantages of exemplary embodiments of this application will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of this application are illustrated by way of example and not limitation, and the same or corresponding reference numerals denote the same or corresponding parts, wherein: Figure 1 An exemplary dimensioning diagram of an imaging lens according to an embodiment of this application is shown; Figure 2 The dimensions of the imaging lens (SAG11, DT11, SAG12) according to an embodiment of this application are shown in the diagram. Figure 3 The dimensions of the imaging lens DT21 and SAG21 according to an embodiment of this application are shown in the diagram. Figure 4 A schematic diagram of the optical structure of an imaging lens according to an embodiment of this application is shown; Figure 5a and 5b The light spot diagram and optical path diagram of the embodiments of this application satisfying (f1+f2) / f=1.81 and (∑CP1+∑CP2) / EP12=0.77 are shown. Figure 6a and 6b The light spot diagram and optical path diagram of the embodiments of this application satisfying (f1+f2) / f=1.81 and (∑CP1+∑CP2) / EP12=1.91 are shown. Figure 7a and 7b The light spot diagram and optical path diagram of the embodiments of this application satisfying (f1+f2) / f=1.81 and (∑CP1+∑CP2) / EP12=2.86 are shown. Figure 8 A schematic diagram of the imaging lens of Embodiment 1-1 of this application is shown; Figure 9 A schematic diagram of the imaging lens of Embodiments 1-2 of this application is shown; Figure 10 Schematic diagrams of the imaging lenses of embodiments 1-3 of this application are shown; Figure 11 The on-axis chromatic aberration curve of the imaging lens of Embodiment 1 of this application is shown; Figure 12 The astigmatism curve of the imaging lens of Embodiment 1 of this application is shown; Figure 13 A schematic diagram of the imaging lens of Embodiment 2-1 of this application is shown; Figure 14 A schematic diagram of the imaging lens of Embodiment 2-2 of this application is shown; Figure 15A schematic diagram of the imaging lens of Embodiments 2-3 of this application is shown; Figure 16 The on-axis chromatic aberration curve of the imaging lens of Embodiment 2 of this application is shown; Figure 17 The astigmatism curve of the imaging lens of Embodiment 2 of this application is shown; Figure 18 A schematic diagram of the imaging lens of Embodiment 3-1 of this application is shown; Figure 19 A schematic diagram of the imaging lens of Embodiment 3-2 of this application is shown; Figure 20 A schematic diagram of the imaging lens of Embodiment 3-3 of this application is shown; Figure 21 The on-axis chromatic aberration curve of the imaging lens of Embodiment 3 of this application is shown; Figure 22 The astigmatism curve of the imaging lens of Embodiment 3 of this application is shown. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] It should be understood that the terms "comprising" and "including" used in the specification and claims of this application indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0023] It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application. As used in this specification and claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this specification and claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations.

[0024] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0025] In this application, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not intended to limit this application.

[0026] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the feature.

[0027] In the accompanying drawings, for ease of illustration, the thickness, size, and shape of the lenses (hereinafter referred to as lens elements) have been slightly exaggerated. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not drawn strictly to scale.

[0028] Unless otherwise specified in this specification, the following terms have the following meanings: Effective half-aperture: refers to the maximum radial radius of the area on the object side or image side of the lens that can transmit effective imaging light rays, which is also the radial half-aperture of the light-transmitting area of ​​the lens surface; the area on the lens surface that exceeds the effective half-aperture is a non-light-transmitting area, which is only used for lens installation and positioning, and the light rays passing through this area do not participate in effective imaging.

[0029] In this manual, the concavity or convexity of the lens surface is determined by the sign of the radius of curvature R: a positive R value on the object side indicates a convex surface, and a negative R value indicates a concave surface; a positive R value on the image side indicates a concave surface, and a negative R value indicates a convex surface.

[0030] In this application, the object side refers to the side of the imaging lens facing the object being photographed (not shown in the figure), and the image side refers to the side of the imaging lens facing the imaging plane. In the following text, the object side of the lens refers to the surface of the lens facing the object being photographed (not shown in the figure), and the image side of the lens refers to the surface of the lens facing the imaging plane. In the structural schematic diagram shown in this application, the left side is the object side, and the right side is the image side.

[0031] To facilitate understanding, let's first combine... Figures 1 to 3 The dimensions of some parts of the imaging lens of this application are described in detail to provide a clear and intuitive understanding of what these dimensions refer to. For ease of description, the surface shapes of each lens in the imaging lens will be described later in specific embodiments, and these parameters will not be shown here.

[0032] Figure 1 An exemplary dimensioning diagram of an imaging lens according to an embodiment of this application is shown. Figure 1As shown, d0s is the inner diameter of the object-side end face of the lens barrel, d0smin is the minimum inner diameter of the object-side side face of the lens barrel, d2s is the inner diameter of the object-side side face of the second spacer element, d1s is the inner diameter of the object-side side face of the first spacer element, EP01 is the distance between the object-side end face of the lens barrel and the object-side side face of the first spacer element along the optical axis, EP12 is the distance between the first spacer element and the second spacer element along the optical axis, EP23 is the distance between the second spacer element and the third spacer element along the optical axis, EP34 is the distance between the third spacer element and the fourth spacer element along the optical axis, CP1 is the maximum thickness of the first spacer element along the optical axis, and CP2 is the maximum thickness of the second spacer element along the optical axis.

[0033] Figure 2 Another exemplary dimensioning diagram of the imaging lens according to an embodiment of this application is shown. For example... Figure 2 As shown, SAG11 is the displacement between the intersection of the object side of the first lens on the optical axis and the vertex of the effective half-aperture of the object side of the first lens, SAG12 is the displacement between the intersection of the image side of the first lens on the optical axis and the vertex of the effective half-aperture of the image side of the first lens, and DT11 is the effective half-aperture of the object side of the first lens.

[0034] Figure 3 A further exemplary dimensioning diagram of the imaging lens according to an embodiment of this application is shown. For example... Figure 3 As shown, DT21 is the effective half-aperture of the object side of the second lens, and SAG21 is the displacement between the intersection of the object side of the second lens on the optical axis and the vertex of the effective half-aperture of the object side of the second lens.

[0035] It should be noted that embodiments of this application may also include those without bonding. Figures 1 to 3 Other dimensions described will not be repeated here. Furthermore, the optical axis mentioned above and below specifically refers to the central axis of symmetry of the imaging lens, around which all lenses are arranged coaxially. The axial distance mentioned above and below refers to the straight-line distance along the optical axis of the imaging lens.

[0036] The imaging lens provided in this application will now be described in detail. The imaging lens of this application includes a lens barrel and a lens group and multiple spacer elements disposed within the lens barrel. The lens barrel includes an object-side end face, an image-side end face, an outer annular surface, and an inner annular surface, wherein the inner annular surface is stepped.

[0037] The optical layout of the lens group can be seen in Figure 4It consists of five lenses, arranged sequentially along the optical axis from the object side to the image side: lens E1, lens E2, lens E3, lens E4, and lens E5. Lens E1 has negative optical power, lens E2 has positive optical power, lens E3 has positive optical power, lens E4 has negative optical power, and lens E5 has positive optical power. Each lens has an object-side surface facing the object and an image-side surface facing the image, and there is an air gap between adjacent lenses.

[0038] like Figure 4 As shown, the lens surfaces are labeled as follows: S1 is the object-side surface of the first lens E1, S2 is the image-side surface of the first lens E1, S3 is the object-side surface of the second lens E2, S4 is the image-side surface of the second lens E2, S5 is the object-side surface of the third lens E3, S6 is the image-side surface of the third lens E3, S7 is the object-side surface of the fourth lens E4, S8 is the image-side surface of the fourth lens E4, S9 is the object-side surface of the fifth lens E5, and S10 is the image-side surface of the fifth lens E5. The surface shapes of each lens surface are as follows: S1 is convex, S2 is concave; S3 is concave, S4 is convex; S5 is convex, S6 is convex; S7 is convex, S8 is concave; S9 is convex, S10 is convex. Furthermore, Figure 4 In the diagram, S11 is the object side of the filter or protective glass, S12 can be the image side of the filter or protective glass, and S13 is the imaging surface.

[0039] At least one spacer element is provided between the first lens E1 and the second lens E2, and between the second lens E2 and the third lens E3. Specifically, the spacer element between the first lens E1 and the second lens E2 includes a first spacer element that contacts the image-side surface S2 of the first lens E1; the spacer element between the second lens E2 and the third lens E3 includes a second spacer element that contacts the image-side surface S4 of the second lens E2.

[0040] Furthermore, the effective focal length f1 of the first lens, the effective focal length f2 of the second lens, and the effective focal length f of the imaging lens satisfy the condition 0.85 < (f1 + f2) / f < 1.85; the sum of the maximum thicknesses of all spacers along the optical axis between the first and second lenses, ∑CP1, the sum of the maximum thicknesses of all spacers along the optical axis between the second and third lenses, ∑CP2, and the distance EP12 between the first and second spacers along the optical axis satisfy the condition 0.90 < (∑CP1 + ∑CP2) / EP12 < 1.95. It should be noted that when multiple spacers are provided within the gap between two lenses (e.g., ... Figure 9 , Figure 10 When ∑CP1 or ∑CP2 is taken as the sum of the maximum thicknesses of each spacer element, a specific example can be found in the description of Embodiment 1 below.

[0041] To demonstrate the specific impact of the above parameter constraints on stray light suppression, the following is a detailed explanation. Figures 5a-7b An analysis was conducted. While maintaining the ratio (f1+f2) / f at 1.81, the performance of the imaging lens was analyzed when (∑CP1+∑CP2) / EP12 took different values. Figures 5a to 7b The light spot diagram and optical path diagram are shown for an incident ray angle of 15° when (∑CP1+∑CP2) / EP12 takes different values. Figure 5a , Figure 6a and Figure 7a In this diagram, Geometrical Ray Spots represents the geometric ray spot pattern, X mm and Y mm represent the spatial positions on the image plane, and FLUX / sq-MM represents the flux per square millimeter.

[0042] Such as light spots Figure 5a He Guanglu Figure 5b As shown, when (f1+f2) / f is 1.81 and (∑CP1+∑CP2) / EP12 is 0.77, the distance between the image side of the first spacer element and the second spacer element along the optical axis is relatively large. In this case, part of the imaging light from the 15° incident light passes through the aperture of the first spacer element and illuminates the edge of the light-transmitting area of ​​the second lens E2. After reflection, it undergoes a secondary reflection on the image side of the first lens E1. This reflection fails to be effectively absorbed by the spacer element in the subsequent path, ultimately forming an arc-shaped stray light on the image surface, leading to a decrease in image quality.

[0043] Such as light spots Figure 6a He Guanglu Figure 6b As shown, when (f1+f2) / f is 1.81 and (∑CP1+∑CP2) / EP12 is 1.91, the thickness and spacing of the spacers between the first and second lenses, and between the second and third lenses, are reasonably configured. For incident light at 15°, while effectively suppressing reflection on the second spacer, it also intercepts stray light rays heading towards the edge of the second lens, thereby effectively reducing stray light and ensuring image clarity.

[0044] Such as light spots Figure 7a He Guanglu Figure 7b As shown, when (f1+f2) / f is 1.81 and (∑CP1+∑CP2) / EP12 is 2.86, the distance between the first and second spacers along the optical axis is too small. An incident light beam at a 15° angle will be reflected at the corner of the second spacer, forming point-like stray light, which also negatively impacts image quality.

[0045] From the above comparative analysis, it can be seen that for the imaging lens provided in this application, the ratio of the sum of the effective focal lengths of the first lens and the second lens to the total focal length of the imaging lens satisfies 0.85 < (f1 + f2) / f < 1.85. The optical power of the front group of lenses is reasonably distributed. However, a relatively large air gap is formed between the first lens, the second lens, and the third lens, and a relatively thick spacer element needs to be provided in the corresponding gap to adapt to the requirements of optical power distribution and structural assembly. However, under this structure, the thick spacer element is likely to cause stray light problems. Based on this, in this application, further control is performed on the total thickness ∑CP1 of all spacer elements between the first lens and the second lens, the total thickness ∑CP2 of all spacer elements between the second lens and the third lens, and the axial spacing distance EP12 between the first spacer element and the second spacer element, so that 0.90 < (∑CP1 + ∑CP2) / EP12 < 1.95. Through the constraint of this conditional formula, the adaptation relationship between the thickness and the spacing of the spacer elements between the first lens, the second lens, and the third lens can be optimized, reducing the risk of stray light caused by the mismatch of the spacing and the reflection of light at the corners of the second spacer element and the non-light-transmitting area of the second lens. The reasonable thickness of the spacer element can block non-imaging light and suppress the generation of stray light, improving the clarity of the imaging picture and adapting to the application requirements of high-resolution imaging in the field of security monitoring.

[0046] In some embodiments of this application, the effective focal length f of the imaging lens and the entrance pupil diameter EPD of the imaging lens satisfy the conditional formula 1.50 ≤ f / EPD ≤ 1.70; the minimum inner diameter d0smin of the object side of the lens barrel and the inner diameter d1s of the object side of the first spacer element satisfy the conditional formula 1.15 < d0smin / d1s < 1.55. Through the constraint of the above two conditional formulas, the large-aperture design requirements of the imaging lens can be met, while ensuring the light-passing ability of the lens in a low-illumination environment, reducing the risk that the effective light is blocked when entering the lens barrel, and reducing the risk of occurrence of stray light and glare ghosts introduced by the edge of the lens barrel or the non-light-transmitting area of the lens, which helps to improve the contrast of the imaging picture.

[0047] In some embodiments of this application, the aperture number FNO of the imaging lens and half of the maximum field angle Semi-FOV of the imaging lens satisfy the conditional formula 2.10 < FNO / TAN(Semi-FOV) < 2.65. This conditional formula constrains the ratio of the aperture number to the tangent value of the half field angle, which can reduce off-axis aberrations such as coma and field curvature caused by the change of the field angle, and then improve the imaging consistency between the edge area and the central area of the picture, and improve the imaging uniformity of the imaging lens within the full field of view under large-aperture conditions.

[0048] In some embodiments of the present application, the spacing distance EP12 between the first spacer element and the second spacer element along the optical axis direction, the maximum thickness CP1 of the first spacer element along the optical axis direction, and the central thickness CT2 of the second lens satisfy the conditional formula 1.05 < (EP12 + CP1) / CT2 < 1.55. Through the constraint of this conditional formula, the arrangement position of the first spacer element and the thickness of the second lens are reasonably set, which can optimize the structural layout of the first lens and the second lens of the lens, reduce the aberration problem caused by improper size setting, and thus improve the imaging quality.

[0049] In some embodiments of the present application, the effective semi-aperture DT11 of the object side surface of the first lens and the effective semi-aperture DT21 of the object side surface of the second lens satisfy the conditional formula 1.60 < DT11 / DT21 ≤ 1.75. At the same time, the effective focal length f1 of the first lens, the inner diameter d0s of the object side end surface of the lens barrel, and the inner diameter d1s of the object side surface of the first spacer element satisfy the conditional formula -7.85 < f1 / (d0s - d1s) < -4.95. By constraining the above two conditional formulas, the light passing apertures of the first lens and the second lens and the aperture sizes of the optical power of the first lens, the lens barrel and the first spacer element are reasonably configured, which can control the incident angle and the change of the light passing aperture of the light after refraction by the first lens, so that the first spacer element can block the non-imaging light rays refracted by the first lens and directed to the edge region, reduce the probability of reflection or scattering of this part of the light rays inside the lens barrel, and thus suppress the generation of stray light and improve the purity of the imaging picture.

[0050] In some embodiments of the present application, a third spacer element is provided between the third lens and the fourth lens, and the third spacer element is in partial contact with the image side surface of the third lens. The spacing distance EP23 between the second spacer element and the third spacer element along the optical axis direction, the maximum thickness CP2 of the second spacer element along the optical axis direction, and the air gap T23 between the second lens and the third lens on the optical axis satisfy the conditional formula 2.20 < (EP23 + CP2) / T23 < 3.25. This conditional formula is beneficial to the size distribution of the lens in the optical axis direction by defining the ratio relationship between the arrangement position of the second spacer element, the axial thickness of the second spacer element and the air gap between the second and third lenses, and improves the assembly adaptability and axial stability of the lens structure.

[0051] In some embodiments of the present application, a fourth spacer element is provided between the fourth lens and the fifth lens, and the fourth spacer element is in contact with the image-side surface portion of the fourth lens. The effective focal length f4 of the fourth lens and the axial spacing distance EP34 between the third spacer element and the fourth spacer element satisfy the conditional expression -2.65 < f4 / EP34 < -2.00. By constraining the optical power of the fourth lens and the axial distance between the third and fourth spacer elements through this conditional expression, the optical characteristics of the fourth lens and the layout positions of the third and fourth spacer elements are further defined, which is conducive to the third spacer element and the fourth spacer element blocking the obliquely incident stray light, reducing the risk of generating glare and ghost images, and improving the purity of the imaging picture.

[0052] In some embodiments of the present application, the combined focal length f345 of the third lens, the fourth lens and the fifth lens, the axial spacing distance EP23 between the second spacer element and the third spacer element, and the axial spacing distance EP34 between the third spacer element and the fourth spacer element satisfy the conditional expression 1.35 < f345 / (EP23 + EP34) < 3.25. By constraining the combined focal length of the third, fourth and fifth lenses and the axial distances of the spacer elements between these lenses through this conditional expression, it is conducive to adjusting the propagation path of the non-imaging light rays refracted or reflected by the third lens and the fourth lens and directed to the edge region. The third spacer element and the fourth spacer element can intercept the non-imaging light rays, reducing the possibility of them finally reaching the imaging surface to form stray light or ghost images, and thus improving the purity of the imaging picture.

[0053] In some embodiments of the present 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, and the central thickness CT2 of the second lens satisfy the conditional expression 2.25 < (T12 + T23) / CT2 < 2.45. At the same time, the sum ∑CP1 of the maximum thicknesses of all spacer elements between the first lens and the second lens along the optical axis and the sum ∑CP2 of the maximum thicknesses of all spacer elements between the second lens and the third lens along the optical axis satisfy the conditional expression 0.35 < ∑CP1 / ∑CP2 < 0.60. By constraining the ratio of the on-axis air gaps of the first lens, the second lens and the third lens to the central thickness of the second lens and the ratio of the axial thicknesses of the spacer elements between the first lens, the second lens and the third lens, a reasonable proportional relationship is formed among the foregoing axial distances to meet the design requirements of a larger air gap in the front section of the lens, which is conducive to controlling the propagation path of the light rays refracted by the foregoing lenses, reducing the light scattering caused by improper settings of the lens sizes and the axial thicknesses of the spacer elements, taking into account the light-shielding effect of the spacer elements and the compactness of the axial layout in the front section of the lens, and improving the structural stability of the optical system.

[0054] In some embodiments of the present application, between the effective focal length f1 of the first lens and the radius of curvature R1 of the object side surface of the first lens, the conditional formula -6.00 < f1 / R1 < -4.30 is satisfied. At the same time, between the displacement SAG12 from the intersection point of the image side surface of the first lens on the optical axis to the vertex of the effective semi-aperture of the image side surface of the first lens, the displacement SAG21 from the intersection point of the object side surface of the second lens on the optical axis to the vertex of the effective semi-aperture of the object side surface of the second lens, and the sum ∑CP1 of the maximum thicknesses of all spacer elements between the first lens and the second lens along the optical axis direction, the conditional formula 1.85 < (SAG12 + |SAG21|) / ∑CP1 < 3.05 is satisfied. Through the constraints of the above two conditional formulas, the surface type parameters of the first lens, the sag heights of the adjacent surfaces of the first lens and the second lens, and the sum of the axial thicknesses of the spacer elements between the two lenses can be reasonably set, so that the surface types of the first and second lenses and the thicknesses of the spacer elements form a reasonable correspondence, which is beneficial to restricting the optical path refracted by the first lens, enabling the spacer elements to intercept the non-imaging light rays emitted from the edge of the first lens, reducing the entry of non-imaging light rays into the second lens, and improving the imaging quality.

[0055] In some embodiments of the present application, between the displacement SAG11 from the intersection point of the object side surface of the first lens on the optical axis to the vertex of the effective semi-aperture of the object side surface of the first lens and the spacer distance EP01 along the optical axis from the object side end face of the lens barrel to the object side surface of the first spacer element, the conditional formula 0.60 < SAG11 / EP01 < 0.75 is satisfied. Through this conditional formula, the sag height of the object side surface of the first lens and the axial spacer between the object side end face of the lens barrel and the first spacer element are restricted, adapting the bending degree of the object side surface of the first lens to the spatial layout between the object side end face of the lens barrel and the first spacer element, optimizing the fitting relationship between the first lens and the object side end of the lens barrel, and enhancing the assembly adaptability and axial stability of the overall structure of the lens.

[0056] In some embodiments of the present application, between the radius of curvature R3 of the object side surface of the second lens and the inner diameter d2s of the object side surface of the second spacer element, the conditional formula -0.80 < R3 / d2s < -0.60 is satisfied. Through this conditional formula, the radius of curvature of the object side surface of the second lens and the inner diameter of the object side surface of the second spacer element are restricted, which is beneficial for the second spacer element to block the non-imaging light rays passing through the edge region of the second lens, reducing the possibility of this part of the light rays continuing to propagate to the imaging surface to form stray light or ghost images, and thus enhancing the purity of the imaging picture.

[0057] [[ID=!9]]The following further describes with reference to the accompanying drawings examples of the specific surface types and parameters of the imaging lens applicable to the above embodiments. !

[0058] It should be noted that in the following Embodiment 1, there are three examples: Embodiment 1-1, Embodiment 1-2, and Embodiment 1-3; in Embodiment 2, there are three examples: Embodiment 2-1, Embodiment 2-2, and Embodiment 2-3; and in Embodiment 3, there are three examples: Embodiment 3-1, Embodiment 3-2, and Embodiment 3-3.

[0059] The imaging lenses in the three examples under the same embodiment maintain consistent lens surface parameters, higher-order coefficients of aspherical surfaces, and core optical parameters, while exhibiting differentiated structural parameters such as lens barrels and spacers. Therefore, the values ​​of the conditional expressions differ between different examples within the same embodiment, and between different examples in different embodiments, and all values ​​fall within the range defined by the aforementioned conditional expressions.

[0060] It should be noted that any one of the examples in Embodiments 1 to 3 described below is applicable to all implementations of this application.

[0061] Example 1 Figure 8 A schematic diagram of the imaging lens of Embodiment 1-1 is shown. Figure 9 A schematic diagram of the imaging lens in Embodiments 1-2 is shown. Figure 10 A schematic diagram of the imaging lens of Embodiments 1-3 is shown.

[0062] like Figure 8 As shown, the imaging lens of Embodiment 1-1 includes a lens barrel P0 and 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 fourth lens E4, a fourth spacer element P4, and a fifth lens E5, which are sequentially arranged along the optical axis from the object side to the image side in the lens barrel P0. Specifically, the first spacer element P1 is located between the first lens E1 and the second lens E2, and contacts the image-side surface S2 of the first lens E1; the second spacer element P2 is located between the second lens E2 and the third lens E3, and contacts the image-side surface S4 of the second lens E2; the third spacer element P3 is located between the third lens E3 and the fourth lens E4, and contacts the image-side surface S6 of the third lens E3; and the fourth spacer element P4 is located between the fourth lens E4 and the fifth lens E5, and contacts the image-side surface S8 of the fourth lens E4.

[0063] The surface shapes of each lens are as follows: S1 and S2 are the object-side and image-side surfaces of the first lens E1, respectively, with S1 being convex and S2 being concave; S3 and S4 are the object-side and image-side surfaces of the second lens E2, respectively, with S3 being concave and S4 being convex; S5 and S6 are the object-side and image-side surfaces of the third lens E3, respectively, with both S5 and S6 being convex; S7 and S8 are the object-side and image-side surfaces of the fourth lens E4, respectively, with S7 being convex and S8 being concave; S9 and S10 are the object-side and image-side surfaces of the fifth lens E5, respectively, with both S9 and S10 being convex.

[0064] like Figure 9 The imaging lenses of Examples 1-2 shown are, with Figure 8 Compared to the imaging lens of Embodiment 1-1, the main difference is that the imaging lens of Embodiment 1-2 further includes a first auxiliary spacer element P1b and a second auxiliary spacer element P2b. The first auxiliary spacer element P1b is located between the first spacer element P1 and the second lens E2, and contacts the image-side surface of the first spacer element P1; the second auxiliary spacer element P2b is located between the second spacer element P2 and the third lens E3, and contacts the image-side surface of the second spacer element P2. The remaining contact relationships and element arrangements are consistent with Embodiment 1-1.

[0065] like Figure 10 The imaging lenses of Examples 1-3 shown are, with Figure 8 Compared to the imaging lens of Embodiment 1-1, the main difference lies in that the imaging lens of Embodiment 1-3 further includes a first auxiliary spacer element P1b, a first auxiliary spacer element P1c, a second auxiliary spacer element P2b, and a second auxiliary spacer element P2c. Specifically, the first auxiliary spacer element P1b is located between the first spacer element P1 and the second lens E2, and contacts the image-side surface of the first spacer element P1; the first auxiliary spacer element P1c is located between the first auxiliary spacer element P1b and the second lens E2, and contacts the image-side surface of the first auxiliary spacer element P1b; the second auxiliary spacer element P2b is located between the second spacer element P2 and the third lens E3, and contacts the image-side surface of the second spacer element P2; the second auxiliary spacer element P2c is located between the second auxiliary spacer element P2b and the third lens E3, and contacts the image-side surface of the second auxiliary spacer element P2b. The remaining contact relationships and element arrangements are consistent with Embodiment 1-1.

[0066] Based on the above structure, in this application, ∑CP1 represents the sum of the maximum thicknesses of all spacer elements between the first lens E1 and the second lens E2, and ∑CP2 represents the sum of the maximum thicknesses of all spacer elements between the second lens E2 and the third lens E3. Specifically: In Embodiment 1-1, ∑CP1 represents the maximum thickness of the first spacer element P1 along the optical axis, and ∑CP2 represents the maximum thickness of the second spacer element P2 along the optical axis. In Embodiment 1-2, ∑CP1 represents the sum of the maximum thicknesses of the first spacer element P1 and the first auxiliary spacer element P1b along the optical axis, and ∑CP2 represents the sum of the maximum thicknesses of the second spacer element P2 and the second auxiliary spacer element P2b along the optical axis. In Embodiment 1-3, ∑CP1 represents the sum of the maximum thicknesses of the first spacer element P1, the first auxiliary spacer element P1b, and the first auxiliary spacer element P1c along the optical axis, and ∑CP2 represents the sum of the maximum thicknesses of the second spacer element P2, the second auxiliary spacer element P2b, and the second auxiliary spacer element P2c along the optical axis. Other embodiments of this application can be deduced similarly.

[0067] Table 1 below shows the basic structural parameters of the imaging lens of Embodiment 1 under Embodiments 1-1, 1-2, and 1-3. The units for radius of curvature and center thickness / spacing are millimeters (mm). In Table 1, OBJ (not shown in the figure) represents the object plane, and STO (such as...) represents the surface plane. Figure 4 (As shown) is the aperture.

[0068] Table 1

[0069] As shown in Table 1, in Embodiment 1, the object-side and image-side surfaces of the first lens E1, the second lens E2, and the fourth to fifth lenses E5 are all aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0070] Where x is the distance vector from the vertex of the aspherical surface along the optical axis at a height of h; c is the paraxial curvature of the aspherical surface, c=1 / R, that is, the paraxial curvature c is the reciprocal of the radius of curvature R in Table 1 above; k is the conic coefficient. These are the i-th order correction coefficients for aspherical surfaces. Tables 2-1 and 2-2 below give the higher-order coefficients A4, A6...A30 that can be used for each aspherical mirror in Example 1.

[0071] Table 2-1

[0072] Table 2-2

[0073] In Embodiment 1, the first lens E1 has negative optical power, the second lens E2 has positive optical power, the third lens E3 has positive optical power, the fourth lens E4 has negative optical power, and the fifth lens E5 has positive optical power. The optical parameters of the imaging lens in Embodiment 1 under Embodiments 1-1, 1-2, and 1-3 are shown in Table 7 below, the structural parameters are shown in Table 8 below (unit: mm), and the values ​​of each conditional expression are shown in Table 9 below.

[0074] Figure 11 The on-axis chromatic aberration curve of the imaging lens of Embodiment 1 is shown, which represents the deflection of the focal point of light of different wavelengths after passing through the imaging lens. Figure 12 The astigmatism curve of the imaging lens in Embodiment 1 is shown, representing the curvature of the meridional and sagittal image planes. Figure 11 and Figure 12 As can be seen, the imaging lens of Embodiment 1 has good control over on-axis chromatic aberration and astigmatism, and the imaging lens given in Embodiment 1 can achieve good imaging quality.

[0075] Example 2 Figure 13 A schematic diagram of the imaging lens in Embodiment 2-1 is shown. Figure 14 A schematic diagram of the imaging lens in Embodiment 2-2 is shown. Figure 15 A schematic diagram of the imaging lens of Embodiments 2-3 is shown.

[0076] like Figure 13 As shown, the imaging lens of Embodiment 2-1 includes a lens barrel P0 and 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 fourth lens E4, a fourth spacer element P4, and a fifth lens E5, which are sequentially arranged along the optical axis from the object side to the image side in the lens barrel P0. Specifically, the first spacer element P1 is located between the first lens E1 and the second lens E2, and contacts the image-side surface S2 of the first lens E1; the second spacer element P2 is located between the second lens E2 and the third lens E3, and contacts the image-side surface S4 of the second lens E2; the third spacer element P3 is located between the third lens E3 and the fourth lens E4, and contacts the image-side surface S6 of the third lens E3; and the fourth spacer element P4 is located between the fourth lens E4 and the fifth lens E5, and contacts the image-side surface S8 of the fourth lens E4.

[0077] S1 and S2 are the object-side and image-side surfaces of the first lens E1, respectively, with S1 being convex and S2 being concave; S3 and S4 are the object-side and image-side surfaces of the second lens E2, respectively, with S3 being concave and S4 being convex; S5 and S6 are the object-side and image-side surfaces of the third lens E3, respectively, with both S5 and S6 being convex; S7 and S8 are the object-side and image-side surfaces of the fourth lens E4, respectively, with S7 being convex and S8 being concave; S9 and S10 are the object-side and image-side surfaces of the fifth lens E5, respectively, with both S9 and S10 being convex.

[0078] like Figure 14 The imaging lens of Embodiment 2-2 shown, and as shown Figure 15 The imaging lenses of Examples 2-3 shown are, with Figure 13 Compared to the imaging lens of Embodiment 2-1, the main difference lies in that the imaging lenses of Embodiments 2-2 and 2-3 further include a first auxiliary spacer element P1b, a first auxiliary spacer element P1c, and a second auxiliary spacer element P2b. Specifically, the first auxiliary spacer element P1b is located between the first spacer element P1 and the second lens E2, and contacts the image-side surface of the first spacer element P1; the first auxiliary spacer element P1c is located between the first auxiliary spacer element P1b and the second lens E2, and contacts the image-side surface of the first auxiliary spacer element P1b; the second auxiliary spacer element P2b is located between the second spacer element P2 and the third lens E3, and contacts the image-side surface of the second spacer element P2. The remaining contact relationships and element arrangements are consistent with Embodiment 2-1.

[0079] Table 3 below shows the basic structural parameters of the imaging lens of Embodiment 2 under Embodiments 2-1, 2-2, and 2-3. The units for radius of curvature and center thickness / spacing are millimeters (mm). In Table 3, OBJ (not shown in the figure) represents the object plane, and STO (such as...) represents the surface plane. Figure 4 (As shown) is the aperture.

[0080] Table 3

[0081] As shown in Table 3, in Embodiment 2, the object-side and image-side surfaces of the first lens E1, the second lens E2, the fourth lens E4 to the fifth lens E5 are all aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the aforementioned formula (1). Tables 4-1 and 4-2 below give the higher-order coefficients A4, A6...A30 that can be used for each aspherical mirror in Embodiment 2.

[0082] Table 4-1

[0083] Table 4-2

[0084] In Embodiment 2, the first lens E1 has negative optical power, the second lens E2 has positive optical power, the third lens E3 has positive optical power, the fourth lens E4 has negative optical power, and the fifth lens E5 has positive optical power. The optical parameters of the imaging lens in Embodiment 2 under Embodiments 2-1, 2-2, and 2-3 are shown in Table 7 below, the structural parameters are shown in Table 8 below (unit: mm), and the values ​​of each conditional expression are shown in Table 9 below.

[0085] Figure 16 The on-axis chromatic aberration curve of the imaging lens of Embodiment 2 is shown, which indicates the deviation of the focal point of light of different wavelengths after passing through the imaging lens. Figure 17 The astigmatism curve of the imaging lens in Embodiment 2 is shown, representing the curvature of the meridional and sagittal image planes. Figure 16 and Figure 17 As can be seen, the imaging lens of Embodiment 2 has good control over on-axis chromatic aberration and astigmatism, and the imaging lens given in Embodiment 2 can achieve good imaging quality.

[0086] Example 3 Figure 18 A schematic diagram of the imaging lens of Embodiment 3-1 is shown. Figure 19 A schematic diagram of the imaging lens of Embodiment 3-2 is shown. Figure 20 A schematic diagram of the imaging lens of Embodiment 3-3 is shown.

[0087] like Figure 18 As shown, the imaging lens of Embodiment 3-1 includes a lens barrel P0 and 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 fourth lens E4, a fourth spacer element P4, and a fifth lens E5, which are sequentially arranged along the optical axis from the object side to the image side in the lens barrel P0. Specifically, the first spacer element P1 is located between the first lens E1 and the second lens E2, and contacts the image-side surface S2 of the first lens E1; the second spacer element P2 is located between the second lens E2 and the third lens E3, and contacts the image-side surface S4 of the second lens E2; the third spacer element P3 is located between the third lens E3 and the fourth lens E4, and contacts the image-side surface S6 of the third lens E3; and the fourth spacer element P4 is located between the fourth lens E4 and the fifth lens E5, and contacts the image-side surface S8 of the fourth lens E4.

[0088] S1 and S2 are the object-side and image-side surfaces of the first lens E1, respectively, with S1 being convex and S2 being concave; S3 and S4 are the object-side and image-side surfaces of the second lens E2, respectively, with S3 being concave and S4 being convex; S5 and S6 are the object-side and image-side surfaces of the third lens E3, respectively, with both S5 and S6 being convex; S7 and S8 are the object-side and image-side surfaces of the fourth lens E4, respectively, with S7 being convex and S8 being concave; S9 and S10 are the object-side and image-side surfaces of the fifth lens E5, respectively, with both S9 and S10 being convex.

[0089] like Figure 19 The imaging lens shown in Embodiment 3-2 and Figure 18 Compared to the imaging lens of Embodiment 3-1, the main difference is that the imaging lens of Embodiment 3-2 further includes a first auxiliary spacer element P1b and a second auxiliary spacer element P2b. The first auxiliary spacer element P1b is located between the first spacer element P1 and the second lens E2, and contacts the image-side surface of the first spacer element P1; the second auxiliary spacer element P2b is located between the second spacer element P2 and the third lens E3, and contacts the image-side surface of the second spacer element P2. The remaining contact relationships and element arrangements are consistent with Embodiment 3-1.

[0090] like Figure 20 The imaging lens shown in Embodiment 3-3, and Figure 18 Compared to the imaging lens of Embodiment 3-1, the main difference in Embodiment 3-3 is that the imaging lens further includes a first auxiliary spacer element P1b, a first auxiliary spacer element P1c, a second auxiliary spacer element P2b, and a second auxiliary spacer element P2c. Specifically, the first auxiliary spacer element P1b is located between the first spacer element P1 and the second lens E2, and contacts the image-side surface of the first spacer element P1; the first auxiliary spacer element P1c is located between the first auxiliary spacer element P1b and the second lens E2, and contacts the image-side surface of the first auxiliary spacer element P1b; the second auxiliary spacer element P2b is located between the second spacer element P2 and the third lens E3, and contacts the image-side surface of the second spacer element P2; the second auxiliary spacer element P2c is located between the second auxiliary spacer element P2b and the third lens E3, and contacts the image-side surface of the second auxiliary spacer element P2b. The remaining contact relationships and element arrangements are consistent with Embodiment 3-1.

[0091] Table 5 below shows the basic structural parameters of the imaging lens of Embodiment 3 under Embodiments 3-1, 3-2, and 3-3. The units for radius of curvature and center thickness / spacing are millimeters (mm). In Table 5, OBJ (not shown in the figure) represents the object plane, and STO (such as...) represents the surface plane. Figure 4 (As shown) is the aperture.

[0092] Table 5

[0093] As shown in Table 5, in Embodiment 3, the object-side and image-side surfaces of the first lens E1, the second lens E2, the fourth lens E4 to the fifth lens E5 are all aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the aforementioned formula (1). Tables 6-1 and 6-2 below give the higher-order coefficients A4, A6...A30 that can be used for each aspherical mirror in Embodiment 3.

[0094] Table 6-1

[0095] Table 6-2

[0096] In Embodiment 3, the first lens E1 has negative optical power, the second lens E2 has positive optical power, the third lens E3 has positive optical power, the fourth lens E4 has negative optical power, and the fifth lens E5 has positive optical power. The optical parameters of the imaging lens in Embodiment 3 under Embodiments 3-1, 3-2, and 3-3 are shown in Table 7 below, the structural parameters are shown in Table 8 below (unit: mm), and the values ​​of each conditional expression are shown in Table 9 below.

[0097] Figure 21 The on-axis chromatic aberration curve of the imaging lens of Embodiment 3 is shown, which indicates the deviation of the focal point of light of different wavelengths after passing through the imaging lens. Figure 22 The astigmatism curve of the imaging lens in Embodiment 3 is shown, representing the curvature of the meridional and sagittal image planes. Figure 21 and Figure 22 As can be seen, the imaging lens of Embodiment 3 has good control over on-axis chromatic aberration and astigmatism, and the imaging lens given in Embodiment 3 can achieve good imaging quality.

[0098] Table 7

[0099] Table 8

[0100] Table 9

[0101] It should be understood that the structure or architecture described above is merely exemplary, and the implementation methods and entities of this application are not limited thereto, but can be modified without departing from the spirit of this application. It is understood that the descriptions of the various embodiments in this application emphasize the differences between the various embodiments, while their similarities or corresponding parts can be referred to mutually. For the sake of brevity, this application will not elaborate on each one.

[0102] While numerous embodiments of this application have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will arise for those skilled in the art without departing from the spirit and intent of this application. It should be understood that various alternatives to the embodiments of this application described herein may be employed in the practice of this application. The appended claims are intended to define the scope of protection of this application and therefore cover equivalents or alternatives within the scope of these claims.

Claims

1. An imaging lens, characterized in that, Includes a lens barrel and a lens assembly disposed within the lens barrel; The lens group consists of five lenses, which are arranged sequentially from the object side to the image side along the optical axis as a first lens with negative optical power, a second lens with positive optical power, a third lens with positive optical power, a fourth lens with negative optical power, and a fifth lens with positive optical power. The first lens has a convex object-side surface and a concave image-side surface; the second lens has a concave object-side surface and a convex image-side surface; the third lens has both a convex object-side surface and an image-side surface; the fourth lens has a convex object-side surface and a concave image-side surface; and the fifth lens has both a convex object-side surface and an image-side surface. At least one spacer element is provided between the first lens and the second lens, and between the second lens and the third lens; the spacer element between the first lens and the second lens includes a first spacer element that contacts the image side of the first lens; the spacer element between the second lens and the third lens includes a second spacer element that contacts the image side of the second lens. The effective focal length f1 of the first lens, the effective focal length f2 of the second lens, and the effective focal length f of the imaging lens satisfy the following condition: 0.85 < (f1 + f2) / f < 1.85; The sum of the maximum thicknesses of all spacers between the first lens and the second lens along the optical axis, ∑CP1, the sum of the maximum thicknesses of all spacers between the second lens and the third lens along the optical axis, ∑CP2, and the spacing distance EP12 between the first spacer and the second spacer along the optical axis satisfy the following condition: 0.90 < (∑CP1 + ∑CP2) / EP12 < 1.

95.

2. The imaging lens according to claim 1, characterized in that, The effective focal length f of the imaging lens and the entrance pupil diameter EPD of the imaging lens satisfy the following condition: 1.50 ≤ f / EPD ≤ 1.70; The minimum inner diameter d0smin of the object side surface of the lens barrel and the inner diameter d1s of the object side surface of the first spacer element satisfy the following condition: 1.15 <d0smin / d1s<1.55。 3. The imaging lens according to claim 1, characterized in that, The aperture number (FNO) of the imaging lens and half of the maximum field of view (Semi-FOV) of the imaging lens satisfy the following condition: 2.10 <FNO / TAN(Semi-FOV)<2.65。 4. The imaging lens according to claim 1, characterized in that, The distance EP12 between the first spacer element and the second spacer element along the optical axis, the maximum thickness CP1 of the first spacer element along the optical axis, and the center thickness CT2 of the second lens satisfy the following condition: 1.05 < (EP12 + CP1) / CT2 < 1.

55.

5. The imaging lens according to claim 1, characterized in that, The effective half-aperture DT11 of the object side of the first lens and the effective half-aperture DT21 of the object side of the second lens satisfy the following condition: 1.60 <DT11 / DT21≤1.75; The effective focal length f1 of the first lens, the inner diameter d0s of the object-side end face of the lens barrel, and the inner diameter d1s of the object-side surface of the first spacer element satisfy the following condition: -7.85 <f1 / (d0s-d1s)<-4.95。 6. The imaging lens according to claim 1, characterized in that, A third spacer element is provided between the third lens and the fourth lens, and the third spacer element is in contact with the image side of the third lens; The spacing between the second spacer element and the third spacer element along the optical axis is EP23, the maximum thickness of the second spacer element along the optical axis is CP2, and the air gap T23 between the second lens and the third lens on the optical axis satisfies: 2.20 < (EP23 + CP2) / T23 < 3.

25.

7. The imaging lens according to claim 6, characterized in that, A fourth spacer element is provided between the fourth lens and the fifth lens, and the fourth spacer element is in contact with the image side of the fourth lens; The effective focal length f4 of the fourth lens and the spacing EP34 between the third and fourth spacers along the optical axis satisfy the following condition: -2.65 <f4 / EP34<-2.00。 8. The imaging lens according to claim 7, characterized in that, The combined focal length of the third lens, the fourth lens, and the fifth lens is f345. The spacing between the second spacer element and the third spacer element along the optical axis, EP23, and the spacing between the third spacer element and the fourth spacer element along the optical axis, EP34, satisfy the following condition: 1.

35. <f345 / (EP23+EP34)<3.25。 9. The 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, and the center thickness CT2 of the second lens satisfy the following condition: 2.25 < (T12 + T23) / CT2 < 2.45; 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 the condition: 0.35 < ∑CP1 / ∑CP2 < 0.

60.

10. The imaging lens according to any one of claims 1-9, characterized in that, The effective focal length f1 of the first lens and the radius of curvature R1 of the object-side surface of the first lens satisfy the following condition: -6.00 <f1 / R1<-4.30; The displacement SAG12 between the intersection of the image-side surface of the first lens on the optical axis and the vertex of the effective half-aperture of the image-side surface of the first lens, the displacement SAG21 between the intersection of the object-side surface of the second lens on the optical axis and the vertex of the effective half-aperture of the object-side surface of the second lens, and the sum of the maximum thicknesses of all spacers between the first lens and the second lens along the optical axis direction ∑CP1 satisfy: 1.85<(SAG12+|SAG21|) / ∑CP1<3.

05.

11. The imaging lens according to any one of claims 1-9, characterized in that, The displacement SAG11 between the intersection of the object-side surface of the first lens on the optical axis and the vertex of the effective half-aperture of the object-side surface of the first lens, and the spacing EP01 between the object-side end face of the lens barrel and the object-side surface of the first spacer element along the optical axis, satisfy: 0.60 <SAG11 / EP01<0.75。 12. The imaging lens according to any one of claims 1-9, characterized in that, The radius of curvature R3 of the object-side surface of the second lens and the inner diameter d2s of the object-side surface of the second spacer element satisfy: -0.80 <R3 / d2s<-0.60。

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