Optical imaging system

Abstract

The application provides an optical imaging system, comprising a lens barrel, and a lens set and a plurality of spacer elements accommodated in the lens barrel; the lens set comprises, in sequence from an object side to an image side along an optical axis direction: a first lens; a second lens; a third lens; a fourth lens; a fifth lens; a sixth lens; a seventh lens; and an eighth lens; the plurality of spacer elements comprises a seventh spacer element, the seventh spacer element is arranged between the seventh lens and the eighth lens, and an object side surface of the seventh spacer element is in contact with an image side surface of the seventh lens; the optical imaging system satisfies: 2.40 < L / (D0m-D0s) ≤ 5.51; 6.00 ≤ TD / T78 < 8.30; and 0.85 < (R14+R15) / D7s < 1.65.

Description

Technical Field

[0001] This application relates to the field of optical device technology, and in particular to an optical imaging system. Background Technology

[0002] With the rapid development of mobile imaging technology, the market has increasingly higher requirements for the compactness and stability of optical imaging systems. Among them, the eight-element optical imaging system, as a representative of high-performance imaging solutions, is widely used in high-end smartphones and other devices.

[0003] While pursuing high pixel count and large aperture, existing eight-element optical imaging systems not only struggle to meet the requirements of miniaturization, but also suffer from insufficient stability in the assembly of imaging system modules and are prone to deformation. As a result, once the imaging system experiences vibration or impact, its optical performance is easily drifted, thereby reducing image quality. Summary of the Invention

[0004] One advantage of this application is that it provides an eight-element optical imaging system. By rationally arranging the internal components of the lens barrel and designing the lens surface, it is possible to improve the mechanical stability and assembly feasibility of the imaging system while maintaining miniaturization, thereby improving the optical performance of the imaging system.

[0005] On one hand, this application provides an optical imaging system, including a lens barrel and a lens group and a plurality of spacer elements housed within the lens barrel; the lens group, along the optical axis from the object side to the image side, sequentially includes: a first lens with negative optical power, whose image side is concave; a second lens with optical power, whose image side is concave; a third lens with optical power, whose image side is convex; a fourth lens with positive optical power; a fifth lens with positive optical power, whose object side is convex; a sixth lens with positive optical power, whose object side is convex; a seventh lens with negative optical power, whose image side is concave; and an eighth lens with negative optical power, whose object side is convex and image side is concave; the plurality of spacer elements includes a seventh spacer element, which is positioned between the seventh lens and the eighth lens. The object-side surface of the seventh spacer element is in contact with the image-side surface of the seventh lens; the optical imaging system satisfies: 2.40 < L / (D0m-D0s) ≤ 5.51; 6.00 ≤ TD / T78 < 8.30; 0.85 < (R14+R15) / D7s < 1.65; where L is the maximum height of the lens barrel, D0m is the outer diameter of the image-side surface of the lens barrel, D0s is the outer diameter of the object-side surface of the lens barrel, TD is the axial distance from the object-side surface of the first lens to the image-side surface of the eighth lens, T78 is the air gap between the seventh lens and the eighth lens on the optical axis, R14 is the radius of curvature of the image-side surface of the seventh lens, R15 is the radius of curvature of the object-side surface of the eighth lens, and D7s is the outer diameter of the object-side surface of the seventh spacer element.

[0006] In some embodiments of this application, the optical imaging system satisfies: 3.92 < (d0s - DT0s) / CT1 < 7.40; where d0s is the inner diameter of the object side of the lens barrel, DT0s is the light-transmitting aperture of the object side of the lens barrel, and CT1 is the center thickness of the first lens.

[0007] In some embodiments of this application, the plurality of spacers includes a first spacer and a second spacer. The first spacer is positioned between the first lens and the second lens, and the object-side surface of the first spacer is in contact with the image-side surface of the first lens. The second spacer is positioned between the second lens and the third lens, and the object-side surface of the second spacer is in contact with the image-side surface of the second lens. The optical imaging system satisfies: 2.68≤(D1m-d1m) / EP12≤10.76; where D1m is the outer diameter of the image-side surface of the first spacer, d1m is the inner diameter of the image-side surface of the first spacer, and EP12 is the distance along the optical axis from the image-side surface of the first spacer to the object-side surface of the second spacer.

[0008] In some embodiments of this application, the plurality of spacers includes a first spacer and a second spacer. The first spacer is placed between the first lens and the second lens, and the object-side surface of the first spacer is in contact with the image-side surface of the first lens. The second spacer is placed between the second lens and the third lens, and the object-side surface of the second spacer is in contact with the image-side surface of the second lens. The optical imaging system satisfies: 1.45≤(T12+CT2) / EP12<2.30; where T12 is the air gap between the first lens and the second lens on the optical axis, CT2 is the center thickness of the second lens, and EP12 is the distance from the image-side surface of the first spacer to the object-side surface of the second spacer along the optical axis.

[0009] In some embodiments of this application, the optical imaging system satisfies: 1.05 < d1s / R2 < 1.65; where d1s is the inner diameter of the object side of the first spacer element, and R2 is the radius of curvature of the image side of the first lens.

[0010] In some embodiments of this application, the plurality of spacers includes a third spacer element, which is placed between the third lens and the fourth lens, and the object-side surface of the third spacer element contacts the image-side surface of the third lens; the optical imaging system satisfies: 2.70 < (CP3 + EP23) / T34 < 3.50; where CP3 is the maximum thickness of the third spacer element along the optical axis, EP23 is the distance from the image-side surface of the second spacer element to the object-side surface of the third spacer element along the optical axis, and T34 is the air gap between the third lens and the fourth lens on the optical axis.

[0011] In some embodiments of this application, the optical imaging system satisfies: -1.90 < d3s / R6 < -0.15; where d3s is the inner diameter of the object side of the third spacer element, and R6 is the radius of curvature of the image side of the third lens.

[0012] In some embodiments of this application, the plurality of spacers includes a fourth spacer, which is positioned between the fourth lens and the fifth lens, with the object-side surface of the fourth spacer in contact with the image-side surface of the fourth lens; the optical imaging system satisfies: 1.00 < EP34 / CT4 ≤ 1.60; where EP34 is the distance along the optical axis from the image-side surface of the third spacer to the object-side surface of the fourth spacer, and CT4 is the center thickness of the fourth lens.

[0013] In some embodiments of this application, the plurality of spacers includes a fifth spacer element, which is positioned between the fifth lens and the sixth lens, with the object-side surface of the fifth spacer element contacting the image-side surface of the fifth lens; the optical imaging system satisfies: 3.90 < f45 / EP45 ≤ 9.46; where f45 is the combined focal length of the fourth lens and the fifth lens, and EP45 is the distance along the optical axis from the image-side surface of the fourth spacer element to the object-side surface of the fifth spacer element.

[0014] In some embodiments of this application, the optical imaging system satisfies: 1.54≤EP45 / SAG51≤4.45; where EP45 is the distance along the optical axis from the image side of the fourth spacer element to the object side of the fifth spacer element, and SAG51 is the axial displacement from the intersection of the object side of the fifth lens and the optical axis to the vertex of the effective radius of the object side of the fifth lens.

[0015] In some embodiments of this application, the optical imaging system satisfies: -7.70≤f1 / (EP01+CT1)≤-1.19; where f1 is the effective focal length of the first lens, EP01 is the distance along the optical axis from the object side of the lens barrel to the object side of the first spacer element, and CT1 is the center thickness of the first lens.

[0016] In some embodiments of this application, the plurality of spacers includes a sixth spacer, which is positioned between the sixth lens and the seventh lens, with the object-side surface of the sixth spacer in contact with the image-side surface of the sixth lens; the optical imaging system satisfies: 1.80 < f6 / d6s ≤ 2.65; where f6 is the effective focal length of the sixth lens, and d6s is the inner diameter of the object-side surface of the sixth spacer.

[0017] In some embodiments of this application, the optical imaging system satisfies: 1.95≤Tr7r14 / (DP7-DP4)<3.95; where Tr7r14 is the distance on the optical axis from the object side of the fourth lens to the image side of the seventh lens, DP7 is the maximum diameter of the seventh lens, and DP4 is the maximum diameter of the fourth lens.

[0018] In some embodiments of this application, the plurality of spacers includes an eighth spacer, which is positioned on the image side of the eighth lens and the object side of the eighth spacer is in contact with the image side of the eighth lens; the optical imaging system satisfies: 0.80 < T78 / (CT7+CT8) < 1.85 and -4.05 ≤ d8s / f78 < -2.20; where T78 is the air gap between the seventh lens and the eighth lens on the optical axis, CT7 is the center thickness of the seventh lens, CT8 is the center thickness of the eighth lens, d8s is the inner diameter of the object side of the eighth spacer, and f78 is the combined focal length of the seventh lens and the eighth lens.

[0019] In some embodiments of this application, the optical imaging system satisfies: 0.89≤|SAG81| / |SAG82|≤2.36 and 0.49≤(d0m-D8m) / CT8≤3.61; where SAG81 is the axial displacement from the intersection of the object-side surface of the eighth lens and the optical axis to the vertex of the effective radius of the object-side surface of the eighth lens, SAG82 is the axial displacement from the intersection of the image-side surface of the eighth lens and the optical axis to the vertex of the effective radius of the image-side surface of the eighth lens, d0m is the inner diameter of the image-side surface of the lens barrel, D8m is the outer diameter of the image-side surface of the eighth spacer element, and CT8 is the center thickness of the eighth lens.

[0020] For the eight-element optical imaging system provided in this application, the size of the lens barrel is limited by controlling the maximum height L of the lens barrel, the outer diameter of the image side of the lens barrel D0m, and the outer diameter of the object side of the lens barrel D0s to satisfy the relationship 2.40<L / (D0m-D0s)≤5.51, thereby meeting the miniaturization design requirements of the optical imaging system. Under these conditions, the axial distance TD between the object side of the first lens and the image side of the eighth lens, the air gap T78 between the seventh and eighth lenses on the optical axis, the radius of curvature R14 of the image side of the seventh lens, the radius of curvature R15 of the object side of the eighth lens, and the outer diameter D7s of the object side of the seventh spacer element are further controlled to satisfy 6.00≤TD / T78<8.30 and 0.85<(R14+R15) / D7s<1.65. By optimizing the axial contact area and radial arrangement distance between the lens and the spacer element, the problem of local stress concentration can be effectively alleviated, thereby reducing the deformation of the rear lens of the imaging system during the assembly process, improving the assembly stability of the internal structure of the imaging system, thereby reducing the optical performance drift of the imaging system when it is vibrated or subjected to impact, and thus maintaining the high-resolution imaging of the full field of view of the imaging system.

[0021] In summary, the optical imaging system of this application improves the mechanical stability and assembly feasibility of the imaging system while maintaining miniaturization by rationally arranging the internal components of the lens barrel and designing the lens surface. Attached Figure Description

[0022] Figure 1A A schematic diagram showing a portion of the parameters of an optical imaging system according to one embodiment of this application is provided.

[0023] Figure 1B A schematic diagram showing another portion of the parameters of an optical imaging system according to one embodiment of this application is illustrated;

[0024] Figure 2 This is a schematic diagram of the structure of an optical imaging system according to Embodiment 1 of this application;

[0025] Figure 3 This is a schematic diagram of the structure of an optical imaging system according to Embodiment 2 of this application;

[0026] Figure 4 This is a schematic diagram of the structure of an optical imaging system according to Embodiment 3 of this application;

[0027] Figure 5 A schematic diagram of the on-axis chromatic aberration curves of the optical imaging systems according to Embodiment 1, Embodiment 2 and Embodiment 3 of this application is shown;

[0028] Figure 6 A schematic diagram of astigmatism curves of the optical imaging systems according to Embodiment 1, Embodiment 2 and Embodiment 3 of this application is shown;

[0029] Figure 7 The diagram shows the distortion curves of the optical imaging systems according to Embodiment 1, Embodiment 2 and Embodiment 3 of this application;

[0030] Figure 8 A schematic diagram of the magnification chromatic aberration curves of the optical imaging systems according to Embodiment 1, Embodiment 2 and Embodiment 3 of this application is shown;

[0031] Figure 9 This is a schematic diagram of the structure of an optical imaging system according to Embodiment 4 of this application;

[0032] Figure 10 This is a schematic diagram of the structure of an optical imaging system according to Embodiment 5 of this application;

[0033] Figure 11 This is a schematic diagram of the structure of an optical imaging system according to Embodiment Six of this application;

[0034] Figure 12A schematic diagram of the on-axis chromatic aberration curves of the optical imaging systems according to Embodiments 4, 5 and 6 of this application is shown;

[0035] Figure 13 A schematic diagram of astigmatism curves for optical imaging systems according to Embodiments 4, 5, and 6 of this application is shown.

[0036] Figure 14 Schematic diagrams of distortion curves of optical imaging systems according to Embodiments 4, 5 and 6 of this application are shown;

[0037] Figure 15 A schematic diagram of the magnification chromatic aberration curves of the optical imaging systems according to Embodiments 4, 5 and 6 of this application is shown;

[0038] Figure 16 This is a schematic diagram of the structure of an optical imaging system according to Embodiment Seven of this application;

[0039] Figure 17 This is a schematic diagram of the structure of an optical imaging system according to Embodiment 8 of this application;

[0040] Figure 18 This is a schematic diagram of the structure of an optical imaging system according to Embodiment Nine of this application;

[0041] Figure 19 A schematic diagram of the on-axis chromatic aberration curves of the optical imaging systems according to Embodiments 7, 8 and 9 of this application is shown;

[0042] Figure 20 A schematic diagram of astigmatism curves for optical imaging systems according to Embodiments 7, 8, and 9 of this application is shown.

[0043] Figure 21 A schematic diagram of the distortion curves of the optical imaging system according to Embodiments 7, 8 and 9 of this application is shown;

[0044] Figure 22 A schematic diagram of the magnification chromatic aberration curves of the optical imaging systems of Embodiments 7, 8 and 9 according to this application is shown.

[0045] Figure 23 An equivalent elastic strain simulation diagram is shown for an optical imaging system according to one embodiment of the present application when L / (D0m-D0s)=4.03, TD / T78=7.02, and (R14+R15) / D7s=1.52.

[0046] Figure 24The equivalent elastic strain simulation diagram of an optical imaging system is shown when L / (D0m-D0s)=4.03, TD / T78=9.20, and (R14+R15) / D7s=2.33.

[0047] Figure 25 The equivalent elastic strain simulation diagram of an optical imaging system is shown when L / (D0m-D0s)=4.03, TD / T78=4.82, and (R14+R15) / D7s=0.55. Detailed Implementation

[0048] 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.

[0049] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0050] 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.

[0051] In this paper, the paraxial region refers to the area near the optical axis. If the lens surface is convex and its location is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and its location is not defined, it means that the lens surface is concave at least in the paraxial region. The surface shape in the paraxial region is determined by the sign of the R value (R refers to the radius of curvature of the paraxial region). In this paper, the surface of each lens closest to the subject is called the object-side surface, and the surface of each lens closest to the imaging plane is called the image-side surface. For the object-side surface, a positive R value indicates a convex surface, and a negative R value indicates a concave surface; for the image-side surface, a positive R value indicates a concave surface, and a negative R value indicates a convex surface.

[0052] 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.

[0053] 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.

[0054] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other. The following embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this application. It should be pointed out that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0055] According to one aspect of this application, reference is made to Figure 1A and Figure 1B The diagram shows partial parameters of an optical imaging system, which may include a lens barrel P0 and a lens group and multiple spacer elements housed within the lens barrel P0.

[0056] The lens group, along the optical axis from the object side to the image side, includes: a first lens E1 with negative optical power, a second lens E2 with optical power, a third lens E3 with optical power, a fourth lens E4 with positive optical power, a fifth lens E5 with positive optical power, a sixth lens E6 with positive optical power, a seventh lens E7 with negative optical power, and an eighth lens E8 with negative optical power. The image-side surface of the first lens E1 is concave; the image-side surface of the second lens E2 is concave; the image-side surface of the third lens E3 is convex; the object-side surface of the fifth lens E5 is convex; the object-side surface of the sixth lens E6 is convex; the image-side surface of the seventh lens E7 is concave; the object-side surface of the eighth lens E8 is convex, and the image-side surface of the eighth lens E8 is concave.

[0057] The plurality of spacers includes a first spacer P1, a second spacer P2, a third spacer P3, a fourth spacer P4, a fifth spacer P5, a sixth spacer P6, a seventh spacer P7, and an eighth spacer P8. The first spacer P1 is positioned between the first lens E1 and the second lens E2, with its object-side surface contacting the image-side surface of the first lens E1. The second spacer P2 is positioned between the second lens E2 and the third lens E3, with its object-side surface contacting the image-side surface of the second lens E2. The third spacer P3 is positioned between the third lens E3 and the fourth lens E4, with its object-side surface contacting the image-side surface of the third lens E3. The fourth spacer P4 is positioned between the fourth lens... The fourth spacer element P4 is positioned between the fifth lens E4 and the fifth lens E5, with its object-side surface contacting the image-side surface of the fourth lens E4; the fifth spacer element P5 is positioned between the fifth lens E5 and the sixth lens E6, with its object-side surface contacting the image-side surface of the fifth lens E5; the sixth spacer element P6 is positioned between the sixth lens E6 and the seventh lens E7, with its object-side surface contacting the image-side surface of the sixth lens E6; the seventh spacer element P7 is positioned between the seventh lens E7 and the eighth lens E8, with its object-side surface contacting the image-side surface of the seventh lens E7; and the eighth spacer element P8 is positioned on the image side of the eighth lens E8, with its object-side surface contacting the image-side surface of the eighth lens E8.

[0058] The optical imaging system satisfies the following conditions: 2.40 < L / (D0m-D0s) ≤ 5.51; 6.00 ≤ TD / T78 < 8.30; 0.85 < (R14+R15) / D7s < 1.65; where L is the maximum height of the lens barrel, D0m is the outer diameter of the image side of the lens barrel, D0s is the outer diameter of the object side of the lens barrel, TD is the axial distance from the object side of the first lens to the image side of the eighth lens, T78 is the air gap between the seventh lens and the eighth lens on the optical axis, R14 is the radius of curvature of the image side of the seventh lens, R15 is the radius of curvature of the object side of the eighth lens, and D7s is the outer diameter of the object side of the seventh spacer element.

[0059] For the eight-element optical imaging system provided in this application, the size of the lens barrel is limited by controlling the maximum height L of the lens barrel, the outer diameter of the image side of the lens barrel D0m, and the outer diameter of the object side of the lens barrel D0s to satisfy the relationship 2.40<L / (D0m-D0s)≤5.51, thereby meeting the miniaturization design requirements of the optical imaging system. Under these conditions, the axial distance TD between the object side of the first lens and the image side of the eighth lens, the air gap T78 between the seventh and eighth lenses on the optical axis, the radius of curvature R14 of the image side of the seventh lens, the radius of curvature R15 of the object side of the eighth lens, and the outer diameter D7s of the object side of the seventh spacer element are further controlled to satisfy 6.00≤TD / T78<8.30 and 0.85<(R14+R15) / D7s<1.65. This optimizes the axial contact area and radial arrangement distance between the lens and the spacer element, alleviates the problem of local stress concentration, reduces the deformation of the rear lens of the imaging system during assembly, improves the stability of the internal structure assembly, reduces the optical performance drift of the imaging system when vibrated or subjected to impact, and thus maintains high-resolution imaging across the entire field of view of the imaging system.

[0060] For example, Figure 23 An equivalent elastic strain simulation diagram is shown for an optical imaging system according to one embodiment of this application, where L / (D0m-D0s)=4.03, TD / T78=7.02, and (R14+R15) / D7s=1.52. When the optical imaging system satisfies L / (D0m-D0s)=4.03, TD / T78=7.02, and (R14+R15) / D7s=1.52, the interference fit between the eighth lens E8 and the lens barrel P0 reaches 0.001mm, and the axial deformation of the eighth lens E8 is 0.36μm, which is less than 0.8μm. The lens deformation is small, and the structure is stable.

[0061] For example, Figure 24 The equivalent elastic strain simulation diagram of an optical imaging system is shown when L / (D0m-D0s)=4.03, TD / T78=9.20, and (R14+R15) / D7s=2.33. When the optical imaging system meets L / (D0m-D0s)=4.03, TD / T78=9.20, and (R14+R15) / D7s=2.33, the contact area between the seventh spacer element P7 and the seventh lens E7 is small, the interference fit between the eighth lens E8 and the lens barrel P0 reaches 0.001mm, and the axial deformation of the eighth lens E8 is 2.46μm, which is greater than 0.8μm. The large lens deformation easily leads to a significant deviation of optical performance from the design value.

[0062] For example, Figure 25The equivalent elastic strain simulation diagram of an optical imaging system is shown when L / (D0m-D0s)=4.03, TD / T78=4.82, and (R14+R15) / D7s=0.55. When the optical imaging system satisfies L / (D0m-D0s)=4.03, TD / T78=4.82, and (R14+R15) / D7s=0.55, the interference fit between the eighth lens E8 and the lens barrel P0 reaches 0.001mm, and the axial deformation of the eighth lens E8 is 2.49μm, which is greater than 0.8μm. The large lens deformation is likely to cause the optical performance to deviate significantly from the design value.

[0063] In some embodiments of this application, the optical imaging system satisfies: 3.92 < (d0s - DT0s) / CT1 < 7.40; where d0s is the inner diameter of the object side surface of the lens barrel P0, DT0s is the light-transmitting aperture of the object side surface of the lens barrel P0, and CT1 is the center thickness of the first lens E1. By controlling the range of (d0s - DT0s) / CT1, it can be ensured that the edge field rays are not blocked by the inner wall of the lens barrel P0 when passing through the edge of the first lens E1, thereby maintaining the uniformity of image plane illumination, and at the same time ensuring the assembly stability of the first lens E1 in the lens barrel P0.

[0064] In some embodiments of this application, the optical imaging system satisfies: 2.68 ≤ (D1m - d1m) / EP12 ≤ 10.76; where D1m is the outer diameter of the image-side surface of the first spacer element P1, d1m is the inner diameter of the image-side surface of the first spacer element P1, and EP12 is the distance along the optical axis from the image-side surface of the first spacer element P1 to the object-side surface of the second spacer element P2. By controlling (D1m - d1m) / EP12, the structural strength and light-shielding performance of the first spacer element P1 can be balanced. Specifically, the radial thickness (D1m - d1m) of the ring wall of the first spacer element P1 must reach a certain size to effectively block obliquely incident stray light and maintain its light-shielding ability. At the same time, by controlling the radial thickness (D1m - d1m), the size of the lens barrel P0 and the amount of material used can also be controlled, which is beneficial to the miniaturization and weight reduction of the imaging system.

[0065] In some embodiments of this application, the optical imaging system satisfies: 1.45 ≤ (T12 + CT2) / EP12 < 2.30; where T12 is the air gap between the first lens E1 and the second lens E2 on the optical axis, CT2 is the center thickness of the second lens E2, and EP12 is the distance along the optical axis from the image side of the first spacer element P1 to the object side of the second spacer element P2. By controlling (T12 + CT2) / EP12, the relationship between the physical thickness of the front lens of the imaging system and the spatial layout of the system can be coordinated, ensuring that the lens can be stably positioned, reducing insufficient mechanical strength, fragility, or deformation caused by difficulties in lens assembly, and ensuring the assembly yield of the optical imaging system.

[0066] In some embodiments of this application, the optical imaging system satisfies: 1.05 < d1s / R2 < 1.65; where d1s is the inner diameter of the object-side surface of the first spacer element P1, and R2 is the radius of curvature of the image-side surface of the first lens E1. By controlling the ratio of the two, the geometric matching relationship between the light-transmitting aperture of the first spacer element P1 and the curvature of the image-side surface of the first lens E1 can be controlled, avoiding mechanical interference, while also improving light-shielding performance and reducing stray light between the lens edge and the aperture of the spacer element.

[0067] In some embodiments of this application, the optical imaging system satisfies: 2.70 < (CP3 + EP23) / T34 < 3.50; where CP3 is the maximum thickness of the third spacer element P3 along the optical axis, EP23 is the distance along the optical axis from the image side of the second spacer element P2 to the object side of the third spacer element P3, and T34 is the air gap between the third lens E3 and the fourth lens E4 on the optical axis. By controlling (CP3 + EP23) / T34, the optical design and mechanical layout can be balanced, ensuring that while the optical air gap meets the aberration optimization conditions, the spacer element has sufficient axial space to achieve positioning, light blocking, and light leakage prevention functions.

[0068] In some embodiments of this application, the optical imaging system satisfies: -1.90 < d3s / R6 < -0.15; where d3s is the inner diameter of the object-side surface of the third spacer element P3, and R6 is the radius of curvature of the image-side surface of the third lens E3. By constraining d3s / R6, it can be ensured that the radius of curvature of the image-side surface of the third lens E3 is reasonably matched with the inner diameter of the object-side surface of the third spacer element P3, reducing unnecessary refraction or reflection of light in the system.

[0069] In some embodiments of this application, the optical imaging system satisfies: 1.00 < EP34 / CT4 ≤ 1.60; where EP34 is the distance along the optical axis from the image-side surface of the third spacer element P3 to the object-side surface of the fourth spacer element P4, and CT4 is the center thickness of the fourth lens E4. By controlling EP34 / CT4, the ratio between the edge thickness and the center thickness of the fourth lens E4 is limited, ensuring the feasibility of forming the fourth lens E4 and ensuring the mechanical strength of the middle part of the optical imaging system.

[0070] In some embodiments of this application, the optical imaging system satisfies: 3.90 < f45 / EP45 ≤ 9.46; where f45 is the combined focal length of the fourth lens E4 and the fifth lens E5, and EP45 is the distance along the optical axis from the image side of the fourth spacer element P4 to the object side of the fifth spacer element P5. By constraining f45 / EP45, the fourth lens E4 and the fifth lens E5 can be combined to perform the function of correcting chromatic aberration and aberrations, achieving synergistic optimization of the optical system's aberration correction capability, space utilization, and stray light control. If f45 / EP45 is too large, it indicates that f45 is too long, and the fourth lens E4 and the fifth lens E5 do not contribute enough to the optical power of the system, reducing the aberration correction effect of the fourth lens E4 and the fifth lens E5; if f45 / EP45 is too small, the resultant force application point of the lens group will be sensitive to the spacing error, resulting in large fluctuations in the system's optical performance.

[0071] In some embodiments of this application, the optical imaging system satisfies: 1.54 ≤ EP45 / SAG51 ≤ 4.45; where EP45 is the distance along the optical axis from the image-side surface of the fourth spacer element P4 to the object-side surface of the fifth spacer element P5, and SAG51 is the axial displacement from the intersection of the object-side surface of the fifth lens E5 and the optical axis to the vertex of the effective radius of the object-side surface of the fifth lens E5. By controlling EP45 / SAG51, not only can the optical system be made more compact, but also the synergistic optimization of lens forming and imaging performance can be achieved. If EP45 / SAG51 is too small, it indicates that EP45 is too small, which not only affects the structural strength of the edge portion of the fifth lens E5, but also indicates that the object-side surface of the fifth lens E5 may bulge too much, be sensitive to tolerances, and easily cause structural interference. If EP45 / SAG51 is too large, it will not be conducive to the miniaturization of the imaging system. On the other hand, it means that if EP45 is too large, external stray light can easily enter the gap between the image side of the fourth spacer element P4 and the object side of the fifth spacer element P5 from the side, and then produce ghosting after being reflected by the lens edge.

[0072] In some embodiments of this application, the optical imaging system satisfies: -7.70 ≤ f1 / (EP01+CT1) ≤ -1.19; where f1 is the effective focal length of the first lens E1, EP01 is the distance along the optical axis from the object-side surface of the lens barrel P0 to the object-side surface of the first spacer element P1, and CT1 is the center thickness of the first lens E1. By controlling f1 / (EP01+CT1), the optical power of the first lens E1 and the axial spatial arrangement of the front section of the lens barrel P0 can be controlled, the refraction angle of light passing through the first lens E1 can be controlled, allowing light to enter the subsequent lens group at a reasonable angle, reducing the pressure of aberration correction, and at the same time avoiding an excessively large overall length of the imaging system, which is beneficial for miniaturization.

[0073] In some embodiments of this application, the optical imaging system satisfies: 1.80 < f6 / d6s ≤ 2.65; where f6 is the effective focal length of the sixth lens E6, and d6s is the inner diameter of the object-side surface of the sixth spacer element P6. By controlling f6 / d6s, it can be ensured that the edge rays of the sixth lens E6 can be effectively blocked by the sixth spacer element P6, thereby improving the imaging quality.

[0074] In some embodiments of this application, the optical imaging system satisfies: 1.95 ≤ Tr7r14 / (DP7-DP4) < 3.95; where Tr7r14 is the distance on the optical axis from the object-side surface of the fourth lens E4 to the image-side surface of the seventh lens E7, DP7 is the maximum diameter of the seventh lens E7, and DP4 is the maximum diameter of the fourth lens E4. By controlling Tr7r14 / (DP7-DP4), the radial dimensional variation trend of the imaging system between the fourth lens E4 and the seventh lens E7 can be controlled, ensuring sufficient space for light to propagate in the axial direction, ensuring the smoothness of beam divergence or convergence, avoiding abrupt changes in aperture or excessively short axial direction that would generate a large number of high-order aberrations, and reducing stray light.

[0075] In some embodiments of this application, the optical imaging system satisfies: 0.80 < T78 / (CT7+CT8) < 1.85 and -4.05 ≤ d8s / f78 < -2.20; where T78 is the air gap between the seventh lens E7 and the eighth lens E8 on the optical axis, CT7 is the center thickness of the seventh lens E7, CT8 is the center thickness of the eighth lens E8, d8s is the inner diameter of the object side of the eighth spacer element P8, and f78 is the combined focal length of the seventh lens E7 and the eighth lens E8. Aberration problems are prone to occur in high-density eight-element optical imaging systems. By controlling T78 / (CT7+CT8), ensuring a reasonable axial arrangement of the seventh lens E7 and the eighth lens E8, further control is applied to d8s / f78 to ensure that the combined optical power of the seventh lens E7 and the eighth lens E8 is negative and of appropriate intensity, preventing severe vignetting due to excessive light divergence.

[0076] In some embodiments of this application, the optical imaging system satisfies: 0.89≤|SAG81| / |SAG82|≤2.36 and 0.49≤(d0m-D8m) / CT8≤3.61; where SAG81 is the axial displacement from the intersection of the object-side surface and the optical axis of the eighth lens E8 to the vertex of the effective radius of the object-side surface of the eighth lens E8, SAG82 is the axial displacement from the intersection of the image-side surface and the optical axis of the eighth lens E8 to the vertex of the effective radius of the image-side surface of the eighth lens E8, d0m is the inner diameter of the image-side surface of the lens barrel P0, D8m is the outer diameter of the image-side surface of the eighth spacer element P8, and CT8 is the center thickness of the eighth lens E8. By controlling |SAG81| / |SAG82| and (d0m-D8m) / CT8, it is possible to balance optical morphology and mechanical design, control the curvature of the object side and image side of the eighth lens E8, ensure the aberration correction capability and manufacturing feasibility of the end lens of the system, and control the mechanical structure near the eighth lens E8 and the thickness of the eighth lens E8 to ensure positioning accuracy while tolerating certain assembly tolerances and thermal expansion tolerances, and control stray light.

[0077] It should be noted that those skilled in the art should understand that the number of spacers constituting the optical imaging system can be changed to obtain the various results and advantages described in this specification without departing from the technical solutions claimed in this application, and this application does not specifically limit this. For example, the optical imaging system may also include other numbers of spacers than those described in the above embodiments, as needed. Some specific, non-limiting embodiments of the above embodiments of this application are described in more detail below with reference to the accompanying drawings.

[0078] For ease of description, in the following embodiments, OBJ represents the object plane, STO represents the aperture, S1 represents the object-side surface of the first lens E1, S2 represents the image-side surface of the first lens E1, S3 represents the object-side surface of the second lens E2, S4 represents the image-side surface of the second lens E2, S5 represents the object-side surface of the third lens E3, S6 represents the image-side surface of the third lens E3, S7 represents the object-side surface of the fourth lens E4, S8 represents the image-side surface of the fourth lens E4, S9 represents the object-side surface of the fifth lens E5, S10 represents the image-side surface of the fifth lens E5, S11 represents the object-side surface of the sixth lens E6, S12 represents the image-side surface of the sixth lens E6, S13 represents the object-side surface of the seventh lens E7, S14 represents the image-side surface of the seventh lens E7, S15 represents the object-side surface of the eighth lens E8, S16 represents the image-side surface of the eighth lens E8, S17 represents the object-side surface of the filter, S18 represents the image-side surface of the filter, and S19 represents the imaging plane (S17, S18, S19 are as follows). Figure 2 As shown in the attached figures, the rest are omitted.

[0079] Example 1

[0080] like Figure 2 As shown, in this embodiment, the optical imaging system includes a lens barrel P0 and a lens group and a plurality of spacer elements housed within the lens barrel P0. The lens group, along the optical axis from the object side to the image side, sequentially includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, and an eighth lens E8. The plurality of spacer elements includes: a first spacer element P1, a second spacer element P2, a third spacer element P3, a fourth spacer element P4, a fifth spacer element P5, a sixth spacer element P6, a seventh spacer element P7, and an eighth spacer element P8.

[0081] In this embodiment, the first lens E1 has negative optical power, the object-side surface S1 of the first lens E1 is convex, and the image-side surface S2 of the first lens E1 is concave; the second lens E2 has negative optical power, the object-side surface S3 of the second lens E2 is concave, and the image-side surface S4 of the second lens E2 is concave; the third lens E3 has positive optical power, the object-side surface S5 of the third lens E3 is convex, and the image-side surface S6 of the third lens E3 is convex; the fourth lens E4 has positive optical power, the object-side surface S7 of the fourth lens E4 is convex, and the image-side surface S8 of the fourth lens E4 is convex. The fifth lens E5 has positive optical power, its object-side surface S9 is convex, and its image-side surface S10 is concave. The sixth lens E6 has positive optical power, its object-side surface S11 is convex, and its image-side surface S12 is convex. The seventh lens E7 has negative optical power, its object-side surface S13 is convex, and its image-side surface S14 is concave. The eighth lens E8 has negative optical power, its object-side surface S15 is convex, and its image-side surface S16 is concave.

[0082] In this embodiment, the aperture STO of the optical imaging system is located between the third lens E3 and the fourth lens E4.

[0083] In addition, Table 1 shows the basic optical parameters of the optical imaging system of Embodiment 1, where the units of radius of curvature and thickness / distance are millimeters (mm).

[0084] Table 1

[0085]

[0086] In this embodiment, the object-side surface and image-side surface of any one of the first lens E1 to the eighth lens E8 are aspherical, and the surface shape x of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0087] ;

[0088] Where x is the distance vector from the vertex of the aspherical surface at a height h along the optical axis; c is the paraxial curvature of the aspherical surface, c = 1 / R (i.e., the paraxial curvature c is the reciprocal of the radius of curvature R in Table 1 above); k is the conic coefficient; Ai is the i-th order correction coefficient of the aspherical surface. Table 2 below gives the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for the aspherical mirrors S1 to S16 in Example 1.

[0089] Table 2

[0090]

[0091] Example 2

[0092] like Figure 3 As shown, in this embodiment, the optical imaging system includes a lens barrel P0 and a lens group and a plurality of spacer elements housed within the lens barrel P0. The lens group, along the optical axis from the object side to the image side, sequentially includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, and an eighth lens E8. The plurality of spacer elements includes: a first spacer element P1, a second spacer element P2, a third spacer element P3, a fourth spacer element P4, a fifth spacer element P5, a sixth spacer element P6, a seventh spacer element P7, and an eighth spacer element P8.

[0093] In this embodiment, the aperture STO of the optical imaging system is located between the third lens E3 and the fourth lens E4.

[0094] It is worth noting that, compared with Embodiment 1 above, the optical imaging system of Embodiment 2 has the same optical parameters, that is, the basic optical parameter table of the optical imaging system of Embodiment 2 is the same as Table 1, and the aspherical higher-order term coefficient table is the same as Table 2. The difference between Embodiment 2 and Embodiment 1 above is that the dimensional values ​​of some structural parameters in the optical imaging system are different. Specifically, the values ​​of various relevant structural parameters in Embodiment 2 and Embodiment 1 above are shown in Table 8.

[0095] Example 3

[0096] like Figure 4 As shown, in this embodiment, the optical imaging system includes a lens barrel P0 and a lens group and a plurality of spacer elements housed within the lens barrel P0. The lens group, along the optical axis from the object side to the image side, sequentially includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, and an eighth lens E8. The plurality of spacer elements includes: a first spacer element P1, a second spacer element P2, a third spacer element P3, a fourth spacer element P4, a fifth spacer element P5, a sixth spacer element P6, a seventh spacer element P7, and an eighth spacer element P8.

[0097] In this embodiment, the aperture STO of the optical imaging system is located between the third lens E3 and the fourth lens E4.

[0098] It is worth noting that, compared with Embodiment 1 above, the optical imaging system of Embodiment 3 has the same optical parameters, that is, the basic optical parameter table of the optical imaging system of Embodiment 3 is the same as Table 1, and the aspherical higher-order term coefficient table is the same as Table 2. The difference between Embodiment 3 and Embodiment 1 above lies in the different dimensional values ​​of some structural parameters in the optical imaging system. Specifically, the values ​​of each relevant structural parameter in Embodiment 3 are shown in Table 8.

[0099] The on-axis chromatic aberration curves of the optical imaging systems in Examples 1, 2, and 3 are as follows: Figure 5 As shown, this indicates the deviation of the focal point after light of different wavelengths passes through the optical imaging system; the astigmatism curves of the optical imaging systems in Embodiments 1, 2, and 3 are shown below. Figure 6 As shown, it represents the curvature of the meridional image plane and the curvature of the sagittal image plane; the distortion curves of the optical imaging systems in Embodiments 1, 2, and 3 are as follows. Figure 7 As shown, it represents the distortion magnitude corresponding to different image heights; the magnification chromatic aberration curves of the optical imaging systems in Examples 1, 2, and 3 are shown below. Figure 8 As shown, this represents the deviation in image height on the imaging plane after light passes through the optical imaging system. According to... Figures 5-8 It can be seen that the optical imaging systems in Embodiment 1, Embodiment 2 and Embodiment 3 can all achieve good imaging quality.

[0100] Example 4

[0101] like Figure 9 As shown, in this embodiment, the optical imaging system includes a lens barrel P0 and a lens group and a plurality of spacer elements housed within the lens barrel P0. The lens group, along the optical axis from the object side to the image side, sequentially includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, and an eighth lens E8. The plurality of spacer elements includes: a first spacer element P1, a second spacer element P2, a third spacer element P3, a fourth spacer element P4, a fifth spacer element P5, a sixth spacer element P6, a seventh spacer element P7, and an eighth spacer element P8.

[0102] In this embodiment, the first lens E1 has negative optical power, the object-side surface S1 of the first lens E1 is convex, and the image-side surface S2 of the first lens E1 is concave; the second lens E2 has negative optical power, the object-side surface S3 of the second lens E2 is concave, and the image-side surface S4 of the second lens E2 is concave; the third lens E3 has positive optical power, the object-side surface S5 of the third lens E3 is convex, and the image-side surface S6 of the third lens E3 is convex; the fourth lens E4 has positive optical power, the object-side surface S7 of the fourth lens E4 is convex, and the image-side surface S8 of the fourth lens E4 is concave. The fifth lens E5 has positive optical power, its object-side surface S9 is convex, and its image-side surface S10 is concave. The sixth lens E6 has positive optical power, its object-side surface S11 is convex, and its image-side surface S12 is concave. The seventh lens E7 has negative optical power, its object-side surface S13 is convex, and its image-side surface S14 is concave. The eighth lens E8 has negative optical power, its object-side surface S15 is convex, and its image-side surface S16 is concave.

[0103] In this embodiment, the aperture STO of the optical imaging system is located between the third lens E3 and the fourth lens E4.

[0104] In addition, Table 3 shows the basic optical parameters of the optical imaging system of Embodiment 4, where the units of radius of curvature and thickness / distance are millimeters (mm).

[0105] Table 3

[0106]

[0107] In this embodiment, the object-side surface and image-side surface of any one of the first lens E1 to the eighth lens E8 are aspherical, and the surface shape x of each aspherical lens can be defined using, but is not limited to, the aspherical formula in Embodiment 1.

[0108] Table 4 below shows the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for each aspherical mirror S1 to S16 in Example 4.

[0109] Table 4

[0110]

[0111] Example 5

[0112] like Figure 10As shown, in this embodiment, the optical imaging system includes a lens barrel P0 and a lens group and a plurality of spacer elements housed within the lens barrel P0. The lens group, along the optical axis from the object side to the image side, sequentially includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, and an eighth lens E8. The plurality of spacer elements includes: a first spacer element P1, a second spacer element P2, a third spacer element P3, a fourth spacer element P4, a fifth spacer element P5, a sixth spacer element P6, a seventh spacer element P7, and an eighth spacer element P8.

[0113] In this embodiment, the aperture STO of the optical imaging system is located between the third lens E3 and the fourth lens E4.

[0114] It is worth noting that, compared with Embodiment 4 above, the optical imaging system of Embodiment 5 has the same optical parameters, that is, the basic optical parameter table of the optical imaging system of Embodiment 5 is the same as Table 3, and the aspherical higher-order term coefficient table is the same as Table 4. The difference between Embodiment 5 and Embodiment 4 above is that the dimensional values ​​of some structural parameters in the optical imaging system are different. Specifically, the values ​​of various relevant structural parameters in Embodiment 5 and Embodiment 4 above are shown in Table 8.

[0115] Example 6

[0116] like Figure 11 As shown, in this embodiment, the optical imaging system includes a lens barrel P0 and a lens group and a plurality of spacer elements housed within the lens barrel P0. The lens group, along the optical axis from the object side to the image side, sequentially includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, and an eighth lens E8. The plurality of spacer elements includes: a first spacer element P1, a second spacer element P2, a third spacer element P3, a fourth spacer element P4, a fifth spacer element P5, a sixth spacer element P6, a seventh spacer element P7, and an eighth spacer element P8.

[0117] In this embodiment, the aperture STO of the optical imaging system is located between the third lens E3 and the fourth lens E4.

[0118] It is worth noting that, compared with Embodiment 4 above, the optical imaging system of Embodiment 6 has the same optical parameters, that is, the basic optical parameter table of the optical imaging system of Embodiment 6 is the same as Table 3, and the aspherical higher-order term coefficient table is the same as Table 4. The difference between Embodiment 6 and Embodiment 4 above is that the dimensional values ​​of some structural parameters in the optical imaging system are different. Specifically, the values ​​of each relevant structural parameter in Embodiment 6 are shown in Table 8.

[0119] The on-axis chromatic aberration curves of the optical imaging systems in Examples 4, 5, and 6 are as follows: Figure 12 As shown, this indicates the deviation of the focal point after light of different wavelengths passes through the optical imaging system; the astigmatism curves of the optical imaging systems in Examples 4, 5, and 6 are shown below. Figure 13 As shown, it represents the curvature of the meridional image plane and the curvature of the sagittal image plane; the distortion curves of the optical imaging systems in Examples 4, 5, and 6 are as follows. Figure 14 As shown, it represents the distortion magnitude corresponding to different image heights; the magnification chromatic aberration curves of the optical imaging systems in Examples 4, 5, and 6 are shown below. Figure 15 As shown, this represents the deviation in image height on the imaging plane after light passes through the optical imaging system. According to... Figures 12-15 It can be seen that the optical imaging systems in Embodiments 4, 5 and 6 can all achieve good imaging quality.

[0120] Example 7

[0121] like Figure 16 As shown, in this embodiment, the optical imaging system includes a lens barrel P0 and a lens group and a plurality of spacer elements housed within the lens barrel P0. The lens group, along the optical axis from the object side to the image side, sequentially includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, and an eighth lens E8. The plurality of spacer elements includes: a first spacer element P1, a second spacer element P2, a third spacer element P3, a fourth spacer element P4, a fifth spacer element P5, a sixth spacer element P6, a seventh spacer element P7, and an eighth spacer element P8.

[0122] In this embodiment, the first lens E1 has negative optical power, the object-side surface S1 of the first lens E1 is concave, and the image-side surface S2 of the first lens E1 is concave; the second lens E2 has positive optical power, the object-side surface S3 of the second lens E2 is convex, and the image-side surface S4 of the second lens E2 is concave; the third lens E3 has negative optical power, the object-side surface S5 of the third lens E3 is concave, and the image-side surface S6 of the third lens E3 is convex; the fourth lens E4 has positive optical power, the object-side surface S7 of the fourth lens E4 is concave, and the image-side surface S8 of the fourth lens E4 is convex. The fifth lens E5 has positive optical power, and its object-side surface S9 and image-side surface S10 are both convex. The sixth lens E6 has positive optical power, and its object-side surface S11 and image-side surface S12 are both convex. The seventh lens E7 has negative optical power, and its object-side surface S13 and image-side surface S14 are both concave. The eighth lens E8 has negative optical power, and its object-side surface S15 and image-side surface S16 are both convex.

[0123] In this embodiment, the aperture STO of the optical imaging system is located between the third lens E3 and the fourth lens E4.

[0124] In addition, Table 5 shows the basic optical parameters of the optical imaging system of Embodiment 7, where the units of radius of curvature and thickness / distance are millimeters (mm).

[0125] Table 5

[0126]

[0127] In this embodiment, the object-side surface and image-side surface of any one of the first lens E1 to the eighth lens E8 are aspherical, and the surface shape x of each aspherical lens can be defined using, but is not limited to, the aspherical formula in Embodiment 1.

[0128] Tables 6-1 and 6-2 below give the higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 that can be used for each aspherical mirror S1 to S16 in Example 7.

[0129] Table 6-1

[0130]

[0131] Table 6-2

[0132]

[0133] Example 8

[0134] like Figure 17 As shown, in this embodiment, the optical imaging system includes a lens barrel P0 and a lens group and a plurality of spacer elements housed within the lens barrel P0. The lens group, along the optical axis from the object side to the image side, sequentially includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, and an eighth lens E8. The plurality of spacer elements includes: a first spacer element P1, a second spacer element P2, a third spacer element P3, a fourth spacer element P4, a fifth spacer element P5, a sixth spacer element P6, a seventh spacer element P7, and an eighth spacer element P8.

[0135] In this embodiment, the aperture STO of the optical imaging system is located between the third lens E3 and the fourth lens E4.

[0136] It is worth noting that, compared with Embodiment Seven above, the optical imaging system of Embodiment Eight has the same optical parameters. That is, the basic optical parameter table of the optical imaging system of Embodiment Eight is the same as Table 5, and the aspherical higher-order term coefficient table is the same as Tables 6-1 and 6-2. The difference between Embodiment Eight and Embodiment Seven above is that the dimensional values ​​of some structural parameters in the optical imaging system are different. Specifically, the values ​​of various relevant structural parameters in Embodiment Seven and Embodiment Eight are shown in Table 8.

[0137] Example 9

[0138] like Figure 18 As shown, in this embodiment, the optical imaging system includes a lens barrel P0 and a lens group and a plurality of spacer elements housed within the lens barrel P0. The lens group, along the optical axis from the object side to the image side, sequentially includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, and an eighth lens E8. The plurality of spacer elements includes: a first spacer element P1, a second spacer element P2, a third spacer element P3, a fourth spacer element P4, a fifth spacer element P5, a sixth spacer element P6, a seventh spacer element P7, and an eighth spacer element P8.

[0139] In this embodiment, the aperture STO of the optical imaging system is located between the third lens E3 and the fourth lens E4.

[0140] It is worth noting that, compared with Embodiment Seven above, the optical imaging system of Embodiment Nine has the same optical parameters. That is, the basic optical parameter table of the optical imaging system of Embodiment Nine is the same as Table 5, and the aspherical higher-order term coefficient table is the same as Tables 6-1 and 6-2. The difference between Embodiment Nine and Embodiment Seven above is that the dimensional values ​​of some structural parameters in the optical imaging system are different. Specifically, the values ​​of each relevant structural parameter in Embodiment Nine are shown in Table 8.

[0141] The on-axis chromatic aberration curves of the optical imaging systems in Examples 7, 8, and 9 are as follows: Figure 19 As shown, this indicates the deviation of the focal point after light of different wavelengths passes through the optical imaging system; the astigmatism curves of the optical imaging systems in Embodiments 7, 8, and 9 are shown below. Figure 20 As shown, it represents the curvature of the meridional image plane and the curvature of the sagittal image plane; the distortion curves of the optical imaging systems in Embodiments 7, 8, and 9 are as follows. Figure 21 As shown, it represents the distortion magnitude corresponding to different image heights; the magnification chromatic aberration curves of the optical imaging systems in Examples 7, 8, and 9 are shown below. Figure 22 As shown, this represents the deviation in image height on the imaging plane after light passes through the optical imaging system. According to... Figures 19-22It can be seen that the optical imaging systems in Embodiments 7, 8 and 9 can all achieve good imaging quality.

[0142] In summary, the optical parameters of the optical imaging systems in Examples 1 to 9 are shown in Table 7 below.

[0143] Table 7

[0144]

[0145] In addition, the structural parameters of the optical imaging systems in Examples 1 to 9 are shown in Table 8, and the unit of each parameter is millimeters (mm).

[0146] Table 8

[0147]

[0148] In summary, the optical imaging systems in Examples 1 to 9 satisfy the relationships shown in Table 9, as detailed in Table 9.

[0149] Table 9

[0150]

Claims

1. An optical imaging system, characterized in that, Includes a lens barrel and a lens assembly and multiple spacer elements housed within the lens barrel; The lens group, along the optical axis from the object side to the image side, comprises: The first lens with negative optical power has a concave image-side surface. A second lens with optical power has a concave image-side surface. A third lens with optical power has a convex image-side surface; A fourth lens with positive optical power; The fifth lens with positive optical power has a convex object-side surface; The sixth lens has positive optical power and its object side is convex. The seventh lens has negative optical power and its image-side surface is concave. The eighth lens, which has negative optical power, has a convex object side and a concave image side. The plurality of spacers includes a seventh spacer, which is positioned between the seventh lens and the eighth lens, and the object side of the seventh spacer is in contact with the image side of the seventh lens; The optical imaging system satisfies: 2.40 < L / (D0m-D0s) ≤ 5.51; 6.00≤TD / T78<8.30; 0.85<(R14+R15) / D7s<1.65; Wherein, L is the maximum height of the lens barrel, D0m is the outer diameter of the image side of the lens barrel, D0s is the outer diameter of the object side of the lens barrel, TD is the axial distance from the object side of the first lens to the image side of the eighth lens, T78 is the air gap between the seventh lens and the eighth lens on the optical axis, R14 is the radius of curvature of the image side of the seventh lens, R15 is the radius of curvature of the object side of the eighth lens, and D7s is the outer diameter of the object side of the seventh spacer element.

2. The optical imaging system according to claim 1, characterized in that, The optical imaging system satisfies: 3.92 < (d0s - DT0s) / CT1 < 7.40; where d0s is the inner diameter of the object side of the lens barrel, DT0s is the light-transmitting aperture of the object side of the lens barrel, and CT1 is the center thickness of the first lens.

3. The optical imaging system according to claim 1, characterized in that, The plurality of spacers include a first spacer and a second spacer. The first spacer is positioned between the first lens and the second lens, and the object side of the first spacer is in contact with the image side of the first lens. The second spacer is positioned between the second lens and the third lens, and the object side of the second spacer is in contact with the image side of the second lens. The optical imaging system satisfies: 2.68≤(D1m-d1m) / EP12≤10.76; where D1m is the outer diameter of the image side of the first spacer element, d1m is the inner diameter of the image side of the first spacer element, and EP12 is the distance along the optical axis from the image side of the first spacer element to the object side of the second spacer element.

4. The optical imaging system according to claim 1, characterized in that, The plurality of spacers include a first spacer and a second spacer. The first spacer is positioned between the first lens and the second lens, and the object side of the first spacer is in contact with the image side of the first lens. The second spacer is positioned between the second lens and the third lens, and the object side of the second spacer is in contact with the image side of the second lens. The optical imaging system satisfies: 1.45≤(T12+CT2) / EP12<2.30; where T12 is the air gap between the first lens and the second lens on the optical axis, CT2 is the center thickness of the second lens, and EP12 is the distance along the optical axis from the image side of the first spacer element to the object side of the second spacer element.

5. The optical imaging system according to claim 1, characterized in that, The plurality of spacers includes a first spacer element, which is disposed between the first lens and the second lens, and the object side of the first spacer element contacts the image side of the first lens. The optical imaging system satisfies: 1.05 < d1s / R2 < 1.65; where d1s is the inner diameter of the object side of the first spacer element, and R2 is the radius of curvature of the image side of the first lens.

6. The optical imaging system according to claim 1, characterized in that, The plurality of spacers includes a second spacer and a third spacer. The second spacer is positioned between the second lens and the third lens, and the object side of the second spacer is in contact with the image side of the second lens. The third spacer is positioned between the third lens and the fourth lens, and the object side of the third spacer is in contact with the image side of the third lens. The optical imaging system satisfies: 2.70 < (CP3 + EP23) / T34 < 3.50; where CP3 is the maximum thickness of the third spacer element along the optical axis, EP23 is the distance from the image side of the second spacer element to the object side of the third spacer element along the optical axis, and T34 is the air gap between the third lens and the fourth lens on the optical axis.

7. The optical imaging system according to claim 1, characterized in that, The plurality of spacers includes a third spacer element, which is positioned between the third lens and the fourth lens, and the object side of the third spacer element contacts the image side of the third lens. The optical imaging system satisfies: -1.90 < d3s / R6 < -0.15; where d3s is the inner diameter of the object side of the third spacer element, and R6 is the radius of curvature of the image side of the third lens.

8. The optical imaging system according to claim 1, characterized in that, The plurality of spacers includes a third spacer and a fourth spacer. The third spacer is positioned between the third lens and the fourth lens, and the object side of the third spacer is in contact with the image side of the third lens. The fourth spacer is positioned between the fourth lens and the fifth lens, and the object side of the fourth spacer is in contact with the image side of the fourth lens. The optical imaging system satisfies: 1.00 < EP34 / CT4 ≤ 1.60; where EP34 is the distance along the optical axis from the image side of the third spacer element to the object side of the fourth spacer element, and CT4 is the center thickness of the fourth lens.

9. The optical imaging system according to claim 1, characterized in that, The plurality of spacers includes a fourth spacer and a fifth spacer. The fourth spacer is positioned between the fourth lens and the fifth lens, and the object side of the fourth spacer is in contact with the image side of the fourth lens. The fifth spacer is positioned between the fifth lens and the sixth lens, and the object side of the fifth spacer is in contact with the image side of the fifth lens. The optical imaging system satisfies: 3.90 < f45 / EP45 ≤ 9.46; where f45 is the combined focal length of the fourth lens and the fifth lens, and EP45 is the distance along the optical axis from the image side of the fourth spacer element to the object side of the fifth spacer element.

10. The optical imaging system according to claim 1, characterized in that, The plurality of spacers includes a fourth spacer and a fifth spacer. The fourth spacer is positioned between the fourth lens and the fifth lens, and the object side of the fourth spacer is in contact with the image side of the fourth lens. The fifth spacer is positioned between the fifth lens and the sixth lens, and the object side of the fifth spacer is in contact with the image side of the fifth lens. The optical imaging system satisfies: 1.54≤EP45 / SAG51≤4.45; where EP45 is the distance along the optical axis from the image side of the fourth spacer element to the object side of the fifth spacer element, and SAG51 is the axial displacement from the intersection of the object side of the fifth lens and the optical axis to the vertex of the effective radius of the object side of the fifth lens.

11. The optical imaging system according to claim 1, characterized in that, The plurality of spacers includes a first spacer element, which is disposed between the first lens and the second lens, and the object side of the first spacer element contacts the image side of the first lens. The optical imaging system satisfies: -7.70≤f1 / (EP01+CT1)≤-1.19; where f1 is the effective focal length of the first lens, EP01 is the distance along the optical axis from the object side of the lens barrel to the object side of the first spacer element, and CT1 is the center thickness of the first lens.

12. The optical imaging system according to claim 1, characterized in that, The plurality of spacers includes a sixth spacer, which is positioned between the sixth lens and the seventh lens, and the object side of the sixth spacer is in contact with the image side of the sixth lens; The optical imaging system satisfies: 1.80 < f6 / d6s ≤ 2.65; where f6 is the effective focal length of the sixth lens and d6s is the inner diameter of the object side of the sixth spacer element.

13. The optical imaging system according to claim 1, characterized in that, The optical imaging system satisfies: 1.95≤Tr7r14 / (DP7-DP4)<3.95; where Tr7r14 is the distance on the optical axis from the object side of the fourth lens to the image side of the seventh lens, DP7 is the maximum diameter of the seventh lens, and DP4 is the maximum diameter of the fourth lens.

14. The optical imaging system according to claim 1, characterized in that, The plurality of spacers includes an eighth spacer, which is positioned on the image side of the eighth lens and the object side of the eighth spacer is in contact with the image side of the eighth lens. The optical imaging system satisfies: 0.80 < T78 / (CT7+CT8) < 1.85 and -4.05 ≤ d8s / f78 < -2.20; where T78 is the air gap between the seventh lens and the eighth lens on the optical axis, CT7 is the center thickness of the seventh lens, CT8 is the center thickness of the eighth lens, d8s is the inner diameter of the object side of the eighth spacer element, and f78 is the combined focal length of the seventh lens and the eighth lens.

15. The optical imaging system according to claim 1, characterized in that, The plurality of spacers includes an eighth spacer, which is positioned on the image side of the eighth lens and the object side of the eighth spacer is in contact with the image side of the eighth lens. The optical imaging system satisfies: 0.89≤|SAG81| / |SAG82|≤2.36 and 0.49≤(d0m-D8m) / CT8≤3.61; where SAG81 is the axial displacement from the intersection of the object-side surface and the optical axis of the eighth lens to the vertex of the effective radius of the object-side surface of the eighth lens, SAG82 is the axial displacement from the intersection of the image-side surface and the optical axis of the eighth lens to the vertex of the effective radius of the image-side surface of the eighth lens, d0m is the inner diameter of the image-side surface of the lens barrel, D8m is the outer diameter of the image-side surface of the eighth spacer element, and CT8 is the center thickness of the eighth lens.

Images