An optical imaging system

Abstract

This invention discloses an optical imaging system, comprising, sequentially from the object side to the image side along the optical axis: an aperture stop; a first lens with optical power, the image side of which is convex; a second lens with positive optical power; a third lens with optical power; a fourth lens with optical power; a fifth lens with optical power; a sixth lens with optical power; a seventh lens with positive optical power; and an eighth lens with optical power. The semi-field of view (FOV) of the optical imaging system satisfies: Semi-FOV < 20°. This achieves a more prominent effect on the subject, especially in portrait photography, making the subject appear more three-dimensional. This invention provides an eight-lens optical imaging system that achieves long focal length, large aperture, and high image quality imaging, effectively balancing various chromatic aberrations, resulting in clearer and purer image quality and excellent optical effects.

Description

Technical Field

[0001] This invention belongs to the field of optical imaging, and particularly relates to an optical imaging system comprising eight lenses. Background Technology

[0002] As smartphone cameras become increasingly powerful, people's demand for mobile photography has also expanded, adding many application scenarios that were not previously covered by mobile phone lenses, such as optical zoom, ultra-wide-angle, and high-definition portraits. In particular, there is a demand for high-definition portrait lenses, as people hope to be able to take "blockbuster" photos with ease, that is, to be able to take high-definition pictures with shallow depth of field, blurred backgrounds, and prominent subjects, thus meeting the growing aesthetic needs of the people.

[0003] Based on this strong demand, this invention proposes an optical imaging lens group composed of eight lenses, which can highlight the subject in the image and create a shallow depth of field background blur effect. With a large aperture structure, it can adapt to more varied environmental changes and capture great shots anytime, anywhere. Summary of the Invention

[0004] The present invention aims to provide an optical imaging system composed of eight lenses, which can highlight the subject in the image, create a shallow depth of field background blur effect, and with a large aperture structure, can adapt to more varied environmental changes, and take great pictures anytime, anywhere.

[0005] This invention provides an optical imaging system comprising, in sequence along the optical axis from the object side to the image side: an aperture stop; a first lens having optical power, the image side of which is convex; a second lens having positive optical power; a third lens having optical power; a fourth lens having optical power; a fifth lens having optical power; a sixth lens having optical power; a seventh lens having positive optical power; and an eighth lens having optical power; wherein, half of the maximum field of view (Semi-FOV) of the optical imaging system satisfies: Semi-FOV < 20°.

[0006] According to one embodiment of the present invention, the axial distance TTL from the side of the first lens to the imaging surface and half the diagonal length ImgH of the effective pixel area on the imaging surface satisfy: TTL / ImgH<3.5.

[0007] According to one embodiment of the present invention, the effective focal length f of the optical imaging system and the entrance pupil diameter EPD of the optical imaging system satisfy: f / EPD < 1.2.

[0008] According to one embodiment of the present invention, the effective focal length f1 of the first lens and the effective focal length f2 of the second lens satisfy: 2.0 < f2 / f1 < 3.0.

[0009] According to one embodiment of the present invention, the effective focal length f3 of the third lens and the effective focal length f of the optical imaging system satisfy: -1.0 < f3 / f < -0.5.

[0010] According to one embodiment of the present invention, the radius of curvature R3 of the object side of the second lens and the radius of curvature R4 of the image side of the second lens satisfy: 2.0 < (R4 + R3) / (R4 - R3) < 3.0.

[0011] According to one embodiment of the present invention, the radius of curvature R6 of the image side of the third lens and the radius of curvature R7 of the object side of the fourth lens satisfy: 3.5 < (R7 + R6) / (R7 - R6) < 5.0.

[0012] According to one embodiment of the present invention, the radius of curvature R8 of the image side of the fourth lens and the radius of curvature R9 of the object side of the fifth lens satisfy: 1.5 < (R8 + R9) / (R8 - R9) < 4.0.

[0013] According to one embodiment of the present invention, the radius of curvature R10 of the image side of the fifth lens and the radius of curvature R11 of the object side of the sixth lens satisfy: 2.5 < R11 / R10 ≤ 7.0.

[0014] According to one embodiment of the present invention, the radius of curvature R12 of the image side surface of the sixth lens and the radius of curvature R14 of the image side surface of the seventh lens satisfy: 1.5 < R12 / R14 < 4.5.

[0015] According to one embodiment of the present invention, the radius of curvature R13 of the object side of the seventh lens and the radius of curvature R16 of the image side of the eighth lens satisfy: 0.5 < R16 / R13 < 2.0.

[0016] According to one embodiment of the present invention, the center thickness CT1 of the first lens on the optical axis and the center thickness CT8 of the eighth lens on the optical axis satisfy: 3.5 < CT1 / CT8 < 10.5.

[0017] According to one embodiment of the present invention, the center thickness CT2 of the second lens on the optical axis and the center thickness CT7 of the seventh lens on the optical axis satisfy: 2.0≤CT2 / CT7<3.5.

[0018] According to one embodiment of the present invention, the air gap T56 between the fifth lens and the sixth lens on the optical axis and the air gap T78 between the seventh lens and the eighth lens on the optical axis satisfy: 1.5 < T56 / T78 ≤ 3.5.

[0019] According to one embodiment of the present invention, the air gap T34 between the third lens and the fourth lens on the optical axis and the air gap T67 between the sixth lens and the seventh lens on the optical axis satisfy: 1.5 < T34 / T67 < 2.5.

[0020] According to one embodiment of the present invention, the Abbe number V1 of the first lens and the Abbe number V2 of the second lens satisfy: V1 = V2.

[0021] According to one embodiment of the present invention, the Abbe number V1 of the first lens and the Abbe number V3 of the third lens satisfy: V1-V3>30.

[0022] According to one embodiment of the present invention, the Abbe number V7 of the seventh lens and the Abbe number V8 of the eighth lens satisfy: V8-V7>15.

[0023] The present invention also provides an optical imaging system comprising, in sequence along the optical axis from the object side to the image side: an aperture stop; a first lens having optical power, the image side of which is convex; a second lens having positive optical power; a third lens having optical power; a fourth lens having optical power; a fifth lens having optical power; a sixth lens having optical power; a seventh lens having positive optical power; and an eighth lens having optical power; wherein the effective focal length f1 of the first lens and the effective focal length f2 of the second lens satisfy: 2.0 < f2 / f1 < 3.0.

[0024] According to one embodiment of the present invention, the axial distance TTL from the side of the first lens to the imaging surface and half the diagonal length ImgH of the effective pixel area on the imaging surface satisfy: TTL / ImgH<3.5.

[0025] According to one embodiment of the present invention, the effective focal length f of the optical imaging system and the entrance pupil diameter EPD of the optical imaging system satisfy: f / EPD < 1.2.

[0026] According to one embodiment of the present invention, half of the maximum field of view (Semi-FOV) of the optical imaging system satisfies: Semi-FOV < 20°.

[0027] According to one embodiment of the present invention, the effective focal length f3 of the third lens and the effective focal length f of the optical imaging system satisfy: -1.0 < f3 / f < -0.5.

[0028] According to one embodiment of the present invention, the radius of curvature R3 of the object side of the second lens and the radius of curvature R4 of the image side of the second lens satisfy: 2.0 < (R4 + R3) / (R4 - R3) < 3.0.

[0029] According to one embodiment of the present invention, the radius of curvature R6 of the image side of the third lens and the radius of curvature R7 of the object side of the fourth lens satisfy: 3.5 < (R7 + R6) / (R7 - R6) < 5.0.

[0030] According to one embodiment of the present invention, the radius of curvature R8 of the image side of the fourth lens and the radius of curvature R9 of the object side of the fifth lens satisfy: 1.5 < (R8 + R9) / (R8 - R9) < 4.0.

[0031] According to one embodiment of the present invention, the radius of curvature R10 of the image side of the fifth lens and the radius of curvature R11 of the object side of the sixth lens satisfy: 2.5 < R11 / R10 ≤ 7.0.

[0032] According to one embodiment of the present invention, the radius of curvature R12 of the image side surface of the sixth lens and the radius of curvature R14 of the image side surface of the seventh lens satisfy: 1.5 < R12 / R14 < 4.5.

[0033] According to one embodiment of the present invention, the radius of curvature R13 of the object side of the seventh lens and the radius of curvature R16 of the image side of the eighth lens satisfy: 0.5 < R16 / R13 < 2.0.

[0034] According to one embodiment of the present invention, the center thickness CT1 of the first lens on the optical axis and the center thickness CT8 of the eighth lens on the optical axis satisfy: 3.5 < CT1 / CT8 < 10.5.

[0035] According to one embodiment of the present invention, the center thickness CT2 of the second lens on the optical axis and the center thickness CT7 of the seventh lens on the optical axis satisfy: 2.0≤CT2 / CT7<3.5.

[0036] According to one embodiment of the present invention, the air gap T56 between the fifth lens and the sixth lens on the optical axis and the air gap T78 between the seventh lens and the eighth lens on the optical axis satisfy: 1.5 < T56 / T78 ≤ 3.5.

[0037] According to one embodiment of the present invention, the air gap T34 between the third lens and the fourth lens on the optical axis and the air gap T67 between the sixth lens and the seventh lens on the optical axis satisfy: 1.5 < T34 / T67 < 2.5.

[0038] According to one embodiment of the present invention, the Abbe number V1 of the first lens and the Abbe number V2 of the second lens satisfy: V1 = V2.

[0039] According to one embodiment of the present invention, the Abbe number V1 of the first lens and the Abbe number V3 of the third lens satisfy: V1-V3>30.

[0040] According to one embodiment of the present invention, the Abbe number V7 of the seventh lens and the Abbe number V8 of the eighth lens satisfy: V8-V7>15.

[0041] The beneficial effects of this invention are:

[0042] The optical imaging system provided by this invention includes multiple lenses, such as the first lens to the eighth lens. By combining lenses with different optical powers and specular concavity / convexity, a long focal length, large aperture, and high image quality imaging lens group is achieved, which can effectively balance various chromatic aberrations, making the image quality clearer and purer, and has excellent optical effects. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a schematic diagram of the lens group structure of Embodiment 1 of the optical imaging system of the present invention;

[0045] Figures 2a to 2d These are the on-axis chromatic aberration curve, astigmatism curve, distortion curve, and magnification chromatic aberration curve of Embodiment 1 of the optical imaging system of the present invention, respectively.

[0046] Figure 3 This is a schematic diagram of the lens group structure of Embodiment 2 of the optical imaging system of the present invention;

[0047] Figures 4a to 4d These are the on-axis chromatic aberration curve, astigmatism curve, distortion curve, and magnification chromatic aberration curve of Embodiment 2 of the optical imaging system of the present invention, respectively.

[0048] Figure 5 This is a schematic diagram of the lens group structure of Embodiment 3 of the optical imaging system of the present invention;

[0049] Figures 6a to 6d These are the on-axis chromatic aberration curve, astigmatism curve, distortion curve, and magnification chromatic aberration curve of embodiment 3 of the optical imaging system of the present invention, respectively.

[0050] Figure 7 This is a schematic diagram of the lens group structure of Embodiment 4 of the optical imaging system of the present invention;

[0051] Figures 8a to 8dThese are the on-axis chromatic aberration curve, astigmatism curve, distortion curve, and magnification chromatic aberration curve of embodiment 4 of the optical imaging system of the present invention, respectively.

[0052] Figure 9 This is a schematic diagram of the lens group structure of Embodiment 5 of the optical imaging system of the present invention;

[0053] Figures 10a to 10d These are the on-axis chromatic aberration curve, astigmatism curve, distortion curve, and magnification chromatic aberration curve of embodiment 5 of the optical imaging system of the present invention, respectively.

[0054] Figure 11 This is a schematic diagram of the lens group structure of Embodiment 6 of the optical imaging system of the present invention;

[0055] Figures 12a to 12d These are, respectively, the on-axis chromatic aberration curve, astigmatism curve, distortion curve, and magnification chromatic aberration curve of Embodiment 6 of the optical imaging system of the present invention. Detailed Implementation

[0056] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] 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 the invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0058] 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.

[0059] 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.

[0060] In the description of this invention, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region. If the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object being photographed is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0061] 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 the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formalized manner unless expressly so specified herein.

[0062] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The features, principles, and other aspects of the present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0063] Exemplary Implementation

[0064] An exemplary embodiment of the optical imaging system of the present invention includes eight lenses, which are sequentially arranged along the optical axis from the object side to the image side as follows: 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, wherein each lens is independent of the others and there is an air gap between each lens on the optical axis.

[0065] In this exemplary embodiment, the lens comprises, sequentially from the object side to the image side along the optical axis: an aperture stop; a first lens with optical power, a second lens with a convex image side and positive optical power; a third lens with optical power; a fourth lens with optical power; a fifth lens with optical power; a sixth lens with optical power; a seventh lens with positive optical power; and an eighth lens with optical power. By combining lenses with different optical powers and specular concavity / convexity, a long focal length, large aperture, and high image quality imaging lens group is achieved, which can effectively balance various chromatic aberrations, resulting in clearer and purer image quality and excellent optical effects.

[0066] In this exemplary embodiment, the axial distance TTL from the side of the first lens to the imaging plane and half the diagonal length ImgH of the effective pixel area on the imaging plane satisfy: TTL / ImgH < 3.5. By compressing this ratio as much as possible, the lens assembly structure becomes more compact, facilitating integration into the mobile phone system, while ensuring a large image plane structure and guaranteeing excellent high-definition image quality output from the system. More specifically, the axial distance TTL from the side of the first lens to the imaging plane and half the diagonal length ImgH of the effective pixel area on the imaging plane satisfy: TTL / ImgH < 3.4.

[0067] In this exemplary embodiment, the effective focal length f of the optical imaging system and the entrance pupil diameter EPD of the optical imaging system satisfy the condition: f / EPD < 1.2. By limiting the range of this ratio, the lens can have a sufficient entrance pupil diameter value, allowing as much light as possible to reach the image plane, adapting to more varied shooting environments, and achieving good image quality even in dark environments. More specifically, in this exemplary embodiment, the effective focal length f of the optical imaging system and the entrance pupil diameter EPD of the optical imaging system satisfy the condition: f / EPD < 1.15.

[0068] In this exemplary embodiment, half of the maximum field of view (Semi-FOV) of the optical imaging system satisfies: Semi-FOV < 20°. Requiring the imaging lens to have a maximum semi-FOV of less than 20 degrees achieves a more prominent effect on the subject, especially in portrait photography, making the subject appear more three-dimensional. More specifically, half of the maximum field of view (Semi-FOV) of the optical imaging system satisfies: Semi-FOV < 19°.

[0069] In this exemplary embodiment, the effective focal length f1 of the first lens and the effective focal length f2 of the second lens satisfy: 2.0 < f2 / f1 < 3.0. By controlling the ratio range of the effective focal lengths of the first and second lenses, the focal lengths of the two adjacent lenses are controlled within a reasonable range, avoiding overly stringent tolerance requirements during manufacturing, thus enabling the lens of the present invention to have better yield performance in subsequent processes. More specifically, the effective focal length f1 of the first lens and the effective focal length f2 of the second lens satisfy: 2.1 < f2 / f1 < 2.9.

[0070] In this exemplary embodiment, the effective focal length f3 of the third lens and the effective focal length f of the optical imaging system satisfy the following condition: -1.0 < f3 / f < -0.5. By controlling the range of the ratio between the effective focal length of the third lens and the optical system, the effective focal length of the third lens can be reasonably configured, effectively reducing the sensitivity of the lens, avoiding overly stringent tolerance requirements, and enabling the lens group to have good imaging performance. More specifically, the effective focal length f3 of the third lens and the effective focal length f of the optical imaging system satisfy the following condition: -0.9 < f3 / f < -0.45.

[0071] In this exemplary embodiment, the radius of curvature R3 of the object-side surface of the second lens and the radius of curvature R4 of the image-side surface of the second lens satisfy: 2.0 < (R4 + R3) / (R4 - R3) < 3.0. By reasonably controlling the ratio of the radii of curvature of the object-side surface and the image-side surface of the second lens, the processing tilt angle of the lens is locked within a reasonable range, improving the sensitivity performance of the lens assembly and promoting subsequent yield optimization. More specifically, the radius of curvature R3 of the object-side surface of the second lens and the radius of curvature R4 of the image-side surface of the second lens satisfy: 1.9 < (R4 + R3) / (R4 - R3) < 2.9.

[0072] In this exemplary embodiment, the radius of curvature R6 of the image-side surface of the third lens and the radius of curvature R7 of the object-side surface of the fourth lens satisfy: 3.5 < (R7 + R6) / (R7 - R6) < 5.0. By reasonably controlling the ratio of the radii of curvature of the image-side surface of the third lens to the object-side surface of the fourth lens, the chromatic aberration performance of the lens group system is effectively balanced, making the front and rear lenses more design-related and balancing the relationship between sensitivity and design values. More specifically, the radius of curvature R6 of the image-side surface of the third lens and the radius of curvature R7 of the object-side surface of the fourth lens satisfy: 3.6 < (R7 + R6) / (R7 - R6) < 4.9.

[0073] In this exemplary embodiment, the radius of curvature R8 of the image-side surface of the fourth lens and the radius of curvature R9 of the object-side surface of the fifth lens satisfy: 1.5 < (R8 + R9) / (R8 - R9) < 4.0. By reasonably controlling the ratio of the radii of curvature of the image-side surface of the fourth lens to the object-side surface of the fifth lens, the lens combination in the middle of the lens group is correlated, which helps to converge the light at the edge of the lens, resulting in a purer and clearer image quality and achieving a beneficial balance in the aberration curve. The radius of curvature R8 of the image-side surface of the fourth lens and the radius of curvature R9 of the object-side surface of the fifth lens satisfy: 1.4 < (R8 + R9) / (R8 - R9) < 3.9.

[0074] In this exemplary embodiment, the radius of curvature R10 of the image-side surface of the fifth lens and the radius of curvature R11 of the object-side surface of the sixth lens satisfy the following ratio: 2.5 < R11 / R10 ≤ 7.0. By reasonably controlling the ratio of the radii of curvature of the image-side surface of the fifth lens to that of the object-side surface of the sixth lens, excessive changes in the processing angle are avoided, which would lead to processing difficulties and facilitate smoother light transmission. More specifically, the radius of curvature R10 of the image-side surface of the fifth lens and the radius of curvature R11 of the object-side surface of the sixth lens satisfy the following ratio: 2.6 < R11 / R10 ≤ 6.9.

[0075] In this exemplary embodiment, the radius of curvature R12 of the image-side surface of the sixth lens and the radius of curvature R14 of the image-side surface of the seventh lens satisfy the following condition: 1.5 < R12 / R14 < 4.5. By reasonably controlling the ratio of the radii of curvature of the image-side surface of the sixth lens to that of the seventh lens, the correlation between the front and rear lenses is increased, the manufacturing difficulty is reduced, and the risk of ghosting is lowered. More specifically, the radius of curvature R12 of the image-side surface of the sixth lens and the radius of curvature R14 of the image-side surface of the seventh lens satisfy the following condition: 1.6 < R12 / R14 < 4.4.

[0076] In this exemplary embodiment, the radius of curvature R13 of the object-side surface of the seventh lens and the radius of curvature R16 of the image-side surface of the eighth lens satisfy the following ratio: 0.5 < R16 / R13 < 2.0. By reasonably controlling the ratio of the radii of curvature of the object-side surface of the seventh lens to the image-side surface of the eighth lens, the light has a smaller incident angle before reaching the image plane, which better matches the incident angle size of the photosensitive element, allowing as much light as possible to reach the image plane, improving image quality, and adapting to more lighting environment requirements. More specifically, the radius of curvature R13 of the object-side surface of the seventh lens and the radius of curvature R16 of the image-side surface of the eighth lens satisfy the following ratio: 0.6 < R16 / R13 < 1.9.

[0077] In this exemplary embodiment, the center thickness CT1 of the first lens on the optical axis and the center thickness CT8 of the eighth lens on the optical axis satisfy: 3.5 < CT1 / CT8 < 10.5. By reasonably controlling the ratio range of the center thicknesses of the first and eighth lenses on the optical axis, the center thickness ranges of the incident and exit lenses can be balanced, avoiding excessive thickness differences. This combination can, to some extent, eliminate the risks of positive and negative spherical aberration and axial chromatic aberration. The center thickness CT1 of the first lens on the optical axis and the center thickness CT8 of the eighth lens on the optical axis satisfy: 3.6 < CT1 / CT8 < 10.4.

[0078] In this exemplary embodiment, the center thickness CT2 of the second lens on the optical axis and the center thickness CT7 of the seventh lens on the optical axis satisfy: 2.0 ≤ CT2 / CT7 < 3.5. By reasonably controlling the ratio range of the center thicknesses of the second and seventh lenses on the optical axis, keeping them within a small range facilitates the overall size optimization of the lens assembly, making the lens more compact and exhibiting better manufacturing performance. The center thickness CT2 of the second lens on the optical axis and the center thickness CT7 of the seventh lens on the optical axis satisfy: 2.1 ≤ CT2 / CT7 < 3.4.

[0079] In this exemplary embodiment, the air gap T56 between the fifth and sixth lenses on the optical axis and the air gap T78 between the seventh and eighth lenses on the optical axis satisfy the following condition: 1.5 < T56 / T78 ≤ 3.5. By reasonably controlling the ratio range of the air gap between the fifth and sixth lenses and the air gap between the seventh and eighth lenses, the lens structure is ensured to have a certain degree of manufacturability, making the spatial distribution between the lenses more uniform, which is beneficial for structural optimization and manufacturing. The air gap T56 between the fifth and sixth lenses on the optical axis and the air gap T78 between the seventh and eighth lenses on the optical axis satisfy the following condition: 1.6 < T56 / T78 ≤ 3.4.

[0080] In this exemplary embodiment, the air gap T34 between the third and fourth lenses on the optical axis and the air gap T67 between the sixth and seventh lenses on the optical axis satisfy the following ratio: 1.5 < T34 / T67 < 2.5. By reasonably controlling the ratio of the air gap between the third and fourth lenses to that between the sixth and seventh lenses and maintaining it within a small range, it is beneficial to arrange different lenses, making chromatic aberration easier to optimize and helping to avoid introducing new stray light during lens assembly. More specifically, the air gap T34 between the third and fourth lenses on the optical axis and the air gap T67 between the sixth and seventh lenses on the optical axis satisfy the following ratio: 1.6 < T34 / T67 < 2.4.

[0081] In this exemplary embodiment, the Abbe number V1 of the first lens and the Abbe number V2 of the second lens satisfy: V1 = V2. By controlling the first and second lenses to have the same Abbe number, the dispersion effect of the two lenses is made consistent, which is beneficial for light of different wavelengths to continue propagating in the same direction after incident, providing a better basis for subsequent elimination of various chromatic aberrations. At the same time, it can introduce light from different directions in accordance with the optical design requirements and maximize the entrance pupil diameter.

[0082] In this exemplary embodiment, the Abbe number V1 of the first lens and the Abbe number V3 of the third lens satisfy: V1 - V3 > 30. By controlling the difference in the Abbe numbers of the first and third lenses, light has good dispersion correction characteristics after passing through the lens structure, thus optimizing on-axis chromatic aberration and magnification chromatic aberration values. More specifically, the Abbe number V1 of the first lens and the Abbe number V3 of the third lens satisfy: V1 - V3 > 31.

[0083] In this exemplary embodiment, the Abbe number V7 of the seventh lens and the Abbe number V8 of the eighth lens satisfy: V8 - V7 > 15. By controlling the difference in the Abbe numbers of the seventh and eighth lenses, chromatic aberration is controlled within a good range before light enters the image plane. The eighth lens, with its higher Abbe number, can balance both chromatic aberration properties and the aforementioned processing properties, resulting in a better optimization and balance of various chromatic aberration values ​​in the lens group, achieving optimal imaging performance. More specifically, the Abbe number V7 of the seventh lens and the Abbe number V8 of the eighth lens satisfy: V8 - V7 > 16.

[0084] In this exemplary embodiment, the object-side surface and image-side surface of any one of the first lens E1 to the eighth lens E8 are aspherical surfaces, and the surface shape x of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0085]

[0086] 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); k is the conic coefficient; Ai is the correction coefficient of the i-th order of the aspherical surface.

[0087] In this exemplary embodiment, the optical imaging system may further include an aperture stop. The aperture stop may be disposed at an appropriate location as needed; for example, the aperture stop may be disposed between the object side and the first lens. Optionally, the optical imaging system may further include a filter for correcting color deviation and / or a protective glass for protecting the photosensitive element located on the imaging surface.

[0088] The optical imaging system according to the above embodiments of the present invention can employ multiple lenses, such as the eight lenses described above. By rationally allocating the optical power, surface shape, center thickness of each lens, and on-axis spacing between each lens, the optical imaging system has a large imaging surface, a wide imaging range, and high imaging quality, while ensuring the ultra-thinness of the mobile phone.

[0089] In an exemplary embodiment, at least one of the mirror surfaces of each lens is an aspherical mirror surface; that is, at least one mirror surface from the object-side surface of the first lens to the image-side surface of the seventh lens is an aspherical mirror surface. The characteristic of an aspherical lens is that its curvature changes continuously from the lens center to the lens periphery. Unlike a spherical lens, which has a constant curvature from the lens center to the lens periphery, an aspherical lens has better curvature radius characteristics, offering advantages in improving distortion aberrations and astigmatism. Using an aspherical lens can eliminate aberrations that occur during imaging as much as possible, thereby improving image quality. Optionally, at least one of the object-side and image-side surfaces of each of the first, second, third, fourth, fifth, sixth, seventh, and eighth lenses is an aspherical mirror surface. Optionally, both the object-side and image-side surfaces of each of the first, second, third, fourth, fifth, sixth, seventh, and eighth lenses are aspherical mirror surfaces.

[0090] However, those skilled in the art will understand that the number of lenses constituting the optical imaging system can be changed without departing from the technical solutions claimed in this application to obtain the various results and advantages described in this specification. For example, although seven lenses are described as an example in the embodiments, the optical imaging system is not limited to including seven lenses, and may include other numbers of lenses if necessary.

[0091] Specific embodiments of the optical imaging system applicable to the above embodiments are further described below with reference to the accompanying drawings. Specific Implementation Example 1

[0093] Figure 1 This is a schematic diagram of the lens group structure of Embodiment 1 of the optical imaging system of the present invention. The optical imaging system includes, in sequence from the object side to the image side along the optical axis: aperture stop STO, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, seventh lens E7, seventh lens E8, filter E9 and imaging surface S19.

[0094] The first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being convex. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has negative optical power, with its object-side surface S5 being concave and its image-side surface S6 being concave. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being concave. The sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being concave. The seventh lens E7 has positive optical power, with its object-side surface S13 being convex and its image-side surface S14 being concave. The eighth lens E8 has negative optical power, with its object-side surface S15 being concave and its image-side surface S16 being concave. The filter E9 has an object-side surface S17 and an image-side surface S18. Light from the object passes sequentially through the surfaces S1 to S19 and is finally imaged on the imaging surface S19.

[0095] Table 1 shows the basic parameters of the optical imaging system in Example 1, where the units for radius of curvature, thickness, and focal length are all millimeters (mm).

[0096]

[0097]

[0098] Table 1

[0099] As shown in Table 2, in Example 1, the total effective focal length of the optical imaging system is f = 9.50 mm, the distance TTL from the object side surface S1 of the first lens E1 to the imaging surface S19 of the optical imaging system on the optical axis is TTL = 10.60 mm, and half the diagonal length of the effective pixel area on the imaging surface S19 is ImgH = 3.31 mm. Half the maximum field of view of the optical imaging lens is Semi-FOV = 19.0°.

[0100]

[0101] Table 2

[0102] The optical imaging system in Example 1 satisfies:

[0103] TTL / ImgH = 3.20, where ImgH is half the diagonal length of the effective pixel area on the imaging plane, and TTL is the on-axis distance from the object side of the first lens to the imaging plane.

[0104] f / EPD = 1.10, where f is the effective focal length of the optical imaging lens and EPD is the entrance pupil diameter of the optical imaging system.

[0105] Semi-FOV = 19.00°, where Semi-FOV is half of the maximum field of view of the optical imaging system.

[0106] f2 / f1 = 2.54, where f1 is the effective focal length of the first lens and f2 is the effective focal length of the second lens.

[0107] f3 / f = -0.58, where f3 is the effective focal length of the third lens and f is the effective focal length of the optical imaging lens.

[0108] (R4+R3) / (R4-R3)=2.73, where R3 is the radius of curvature of the object side of the second lens and R4 is the radius of curvature of the image side of the second lens.

[0109] (R7+R6) / (R7-R6)=4.64, where R6 is the radius of curvature of the image side of the third lens and R7 is the radius of curvature of the object side of the fourth lens.

[0110] (R8+R9) / (R8-R9)=1.91, where R8 is the radius of curvature of the image side of the fourth lens and R9 is the radius of curvature of the object side of the fifth lens.

[0111] R11 / R10 = 6.95, where R10 is the radius of curvature of the image side of the fifth lens and R11 is the radius of curvature of the object side of the sixth lens.

[0112] R12 / R14 = 2.47, where R12 is the radius of curvature of the image side of the sixth lens and R14 is the radius of curvature of the image side of the seventh lens.

[0113] R16 / R13 = 1.46, where R13 is the radius of curvature of the object side of the seventh lens and R16 is the radius of curvature of the image side of the eighth lens.

[0114] CT1 / CT8 = 6.07, where CT1 is the center thickness of the first lens on the optical axis and CT8 is the center thickness of the eighth lens on the optical axis.

[0115] CT2 / CT7 = 3.03, where CT2 is the center thickness of the second lens on the optical axis and CT7 is the center thickness of the seventh lens on the optical axis.

[0116] T56 / T78 = 1.89, where T56 is the air gap between the fifth and sixth lenses on the optical axis, and T78 is the air gap between the seventh and eighth lenses on the optical axis.

[0117] T34 / T67 = 1.79, where T34 is the air gap between the third and fourth lenses on the optical axis, and T67 is the air gap between the sixth and seventh lenses on the optical axis.

[0118] V1 = V2 = 56.10, where V1 is the Abbe number of the first lens and V2 is the Abbe number of the second lens.

[0119] V1-V3=36.90, where V1 is the Abbe number of the first lens and V3 is the Abbe number of the third lens.

[0120] V8-V7=18.20, where V7 is the Abbe number of the seventh lens and V8 is the Abbe number of the eighth lens.

[0121] In Example 1, the object-side surface and image-side surface of any one of the lenses from the first lens E1 to the eighth lens E8 are aspherical. Table 3 shows the higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror S1-S16 in Example 1. 10 A 12 A 14 A 16 A 18 A 20 A 22 A 24 A 26 A 28 and A 30 .

[0122] Face number A4 A6 A8 A10 A12 A14 A16 S1 -6.8021E-01 -1.9174E-01 -4.8488E-02 -1.0949E-02 -2.6792E-03 -1.2448E-03 -6.9561E-04 S2 2.5773E-01 -3.6458E-02 5.1199E-03 4.1182E-03 -9.1713E-04 4.6242E-04 -2.5124E-04 S3 1.5364E-01 6.1660E-02 -7.3099E-03 -3.3406E-03 -4.4656E-03 -2.0260E-03 -8.7368E-04 S4 -4.1567E-01 6.8882E-02 -2.4375E-02 4.9352E-03 -2.2089E-03 -3.7559E-04 2.4634E-04 S5 5.5920E-01 -6.9169E-02 3.8426E-02 -9.0522E-03 5.1568E-03 -1.4849E-03 5.7773E-04 S6 3.3495E-01 -4.7762E-02 1.5209E-02 -2.6471E-03 1.4417E-03 3.4131E-04 -5.6138E-05 S7 -2.7385E-02 -3.1513E-02 1.1181E-03 -1.4250E-03 1.7614E-04 5.2572E-04 -1.1137E-04 S8 1.1912E-01 3.0235E-02 1.3959E-02 -9.5581E-04 6.6852E-04 4.6661E-04 -7.6005E-05 S9 -9.5312E-01 4.7767E-02 -9.5662E-03 -1.2767E-02 -2.2261E-03 -9.7589E-04 -3.7759E-04 S10 -9.7024E-01 9.5325E-03 -1.3656E-02 -9.6989E-03 -3.5612E-03 -1.7930E-03 -8.2891E-04 S11 -4.0923E-01 -1.2813E-02 3.0585E-03 2.8838E-03 9.2996E-04 -1.7282E-04 -4.2621E-04 S12 -8.6568E-01 5.7261E-02 -8.0173E-03 3.3923E-03 1.5316E-03 4.1447E-04 -3.8632E-04 S13 -1.6655E+00 9.5360E-02 1.6554E-02 2.1539E-03 2.6092E-03 -5.3553E-05 -2.0747E-03 S14 -1.6008E+00 1.2329E-01 1.7472E-02 1.2116E-02 2.1080E-03 -1.0901E-04 -1.9636E-03 S15 -1.1755E+00 4.2435E-01 -1.3800E-01 8.4622E-02 -2.9691E-02 1.2087E-02 -5.6817E-03 S16 -2.2210E+00 4.1737E-01 -1.9140E-01 9.8151E-02 -3.2032E-02 1.8089E-02 -4.8404E-03 Face number A18 A20 A22 A24 A26 A28 A30 S1 -3.9244E-04 -1.7650E-04 -7.3032E-05 -1.1228E-05 -9.2451E-06 -3.4610E-06 0.0000E+00 S2 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S3 -3.9692E-04 -3.8792E-05 2.4224E-05 3.8783E-05 2.7169E-06 2.5773E-07 0.0000E+00 S4 5.5444E-08 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S5 -5.6948E-06 8.1270E-06 1.5286E-05 2.3531E-06 0.0000E+00 0.0000E+00 0.0000E+00 S6 -3.0937E-05 -7.6348E-05 -4.0947E-05 -2.5351E-05 -2.1702E-06 0.0000E+00 0.0000E+00 S7 -5.6486E-05 -1.2249E-05 -9.0744E-06 1.1803E-05 0.0000E+00 0.0000E+00 0.0000E+00 S8 -1.5711E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S9 4.8847E-05 3.9760E-06 -5.1750E-06 -2.6923E-06 0.0000E+00 0.0000E+00 0.0000E+00 S10 -1.7709E-04 -5.5074E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S11 -2.5970E-04 -7.8736E-05 -3.4594E-05 -2.2868E-06 0.0000E+00 0.0000E+00 0.0000E+00 S12 -1.2033E-05 -5.5954E-07 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S13 4.5504E-04 4.0373E-04 -3.0180E-05 -3.2080E-06 2.2100E-08 6.4197E-09 0.0000E+00 S14 1.0286E-03 -2.2156E-04 -2.7660E-04 -1.9798E-06 -3.8687E-07 0.0000E+00 0.0000E+00 S15 6.5995E-04 -1.2209E-03 4.6249E-04 1.9678E-04 1.1800E-05 1.0166E-06 9.2602E-08 S16 1.9103E-03 -1.4544E-03 2.9275E-04 -3.8894E-04 -2.2088E-05 -1.7789E-06 0.0000E+00

[0123] Table 3

[0124] Figure 2a The on-axis chromatic aberration curve of the optical imaging system of Embodiment 1 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 2b The astigmatism curves of the optical imaging system of Embodiment 1 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 2c The distortion curves of the optical imaging system of Example 1 are shown, which represent the distortion magnitude values ​​corresponding to different image heights. Figure 2d The magnification chromatic aberration curve of the optical imaging system of Embodiment 1 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the lens. According to Figures 2a to 2d As can be seen from the figure, the optical imaging system given in Example 1 can achieve good imaging quality. Specific Implementation Example 2

[0126] Figure 3 This is a schematic diagram of the lens group structure of Embodiment 2 of the optical imaging system of the present invention. The optical imaging system includes, in sequence from the object side to the image side along the optical axis: aperture stop STO, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, seventh lens E7, seventh lens E8, filter E9 and imaging surface S19.

[0127] The first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being convex. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has negative optical power, with its object-side surface S5 being concave and its image-side surface S6 being concave. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. The fifth lens E5 has negative optical power, with its object-side surface S9 being convex and its image-side surface S10 being concave. The sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being concave. The seventh lens E7 has positive optical power, with its object-side surface S13 being convex and its image-side surface S14 being concave. The eighth lens E8 has negative optical power, with its object-side surface S15 being concave and its image-side surface S16 being concave. The filter E9 has an object-side surface S17 and an image-side surface S18. Light from the object passes sequentially through the surfaces S1 to S19 and is finally imaged on the imaging surface S19.

[0128] Table 4 shows the basic parameters of the optical imaging system in Example 2, where the units for radius of curvature, thickness, and focal length are all millimeters (mm).

[0129]

[0130] Table 4

[0131] As shown in Table 5, in Example 2, the total effective focal length of the optical imaging system is f = 9.40 mm, the distance TTL from the object side surface S1 of the first lens E1 to the imaging surface S19 of the optical imaging system on the optical axis is TTL = 10.50 mm, and half the diagonal length of the effective pixel area on the imaging surface S19 is ImgH = 3.31 mm. Half the maximum field of view of the optical imaging lens is Semi-FOV = 19.1°.

[0132]

[0133] In Example 2, the object-side surface and image-side surface of any one of the lenses from the first lens E1 to the eighth lens E8 are aspherical. Table 6 shows the higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror S1-S16 in Example 2. 10 A 12 A 14 A 16 A 18 A 20 A 22 A 24 A 26 A 28 and A 30 .

[0134]

[0135]

[0136] Table 6

[0137] Figure 4a The on-axis chromatic aberration curve of the optical imaging system of Embodiment 2 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 4b The astigmatism curves of the optical imaging system of Embodiment 2 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 4c The distortion curves of the optical imaging system of Example 2 are shown, which represent the distortion magnitude values ​​corresponding to different image heights. Figure 4d The magnification chromatic aberration curve of the optical imaging system of Embodiment 2 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the lens. According to Figures 4a to 4d As shown, the optical imaging system given in Example 2 can achieve good imaging quality. Specific Implementation Example 3

[0139] Figure 5 This is a schematic diagram of the lens group structure of embodiment 3 of the optical imaging system of the present invention. The optical imaging system includes, in sequence from the object side to the image side along the optical axis: aperture stop STO, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, seventh lens E7, seventh lens E8, filter E9 and imaging surface S19.

[0140] The first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being convex. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has negative optical power, with its object-side surface S5 being concave and its image-side surface S6 being concave. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being concave. The sixth lens E6 has negative optical power, with its object-side surface S11 being convex and its image-side surface S12 being concave. The seventh lens E7 has positive optical power, with its object-side surface S13 being convex and its image-side surface S14 being concave. The eighth lens E8 has negative optical power, with its object-side surface S15 being convex and its image-side surface S16 being concave. The filter E9 has an object-side surface S17 and an image-side surface S18. Light from the object passes sequentially through the surfaces S1 to S19 and is finally imaged on the imaging surface S19.

[0141] Table 7 shows the basic parameters of the optical imaging system in Example 3, where the units for radius of curvature, thickness, and focal length are all millimeters (mm).

[0142]

[0143]

[0144] Table 7

[0145] As shown in Table 8, in Example 3, the total effective focal length of the optical imaging system is f = 9.40 mm, the distance TTL from the object side surface S1 of the first lens E1 to the imaging surface S19 of the optical imaging system on the optical axis is TTL = 10.45 mm, and half the diagonal length of the effective pixel area on the imaging surface S19 is ImgH = 3.31 mm. Half the maximum field of view of the optical imaging lens is Semi-FOV = 19.3°.

[0146]

[0147] Table 8

[0148] In Example 3, the object-side surface and image-side surface of any one of the lenses from the first lens E1 to the eighth lens E8 are aspherical. Table 9 shows the higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror S1-S16 in Example 3. 10 A 12 A 14 A 16 A 18 A 20 A 22 A 24 A 26 A 28 and A 30 .

[0149]

[0150]

[0151] Table 9

[0152] Figure 6a The on-axis chromatic aberration curve of the optical imaging system of Embodiment 3 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 6b The astigmatism curves of the optical imaging system of Example 3 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 6c The distortion curves of the optical imaging system of Example 3 are shown, which represent the distortion magnitude values ​​corresponding to different image heights. Figure 6d The magnification chromatic aberration curve of the optical imaging system of Embodiment 3 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the lens. According to Figures 6a to 6d As shown, the optical imaging system given in Example 3 can achieve good imaging quality. Specific Implementation Example 4

[0154] Figure 7 This is a schematic diagram of the lens group structure of embodiment 4 of the optical imaging system of the present invention. The optical imaging system includes, in sequence from the object side to the image side along the optical axis: aperture stop STO, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, seventh lens E7, seventh lens E8, filter E9 and imaging surface S19.

[0155] The first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being convex. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has negative optical power, with its object-side surface S5 being concave and its image-side surface S6 being concave. The fourth lens E4 has negative optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being concave. The sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being concave. The seventh lens E7 has positive optical power, with its object-side surface S13 being convex and its image-side surface S14 being concave. The eighth lens E8 has negative optical power, with its object-side surface S15 being convex and its image-side surface S16 being concave. The filter E9 has an object-side surface S17 and an image-side surface S18. Light from the object passes sequentially through the surfaces S1 to S19 and is finally imaged on the imaging surface S19.

[0156] Table 10 shows the basic parameters of the optical imaging system in Example 4, where the units for radius of curvature, thickness, and focal length are all millimeters (mm).

[0157]

[0158] Table 10

[0159] As shown in Table 11, in Example 4, the total effective focal length of the optical imaging system is f = 9.38 mm, the distance TTL from the object side surface S1 of the first lens E1 to the imaging surface S19 of the optical imaging system on the optical axis is TTL = 10.40 mm, and half the diagonal length of the effective pixel area on the imaging surface S19 is ImgH = 3.31 mm. Half the maximum field of view of the optical imaging lens is Semi-FOV = 19.4°.

[0160]

[0161] Table 11

[0162] In Example 4, the object-side surface and image-side surface of any one of the lenses from the first lens E1 to the eighth lens E8 are aspherical. Table 12 shows the higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror S1-S16 in Example 4. 10 A12 A 14 A 16 A 18 A 20 A 22 A 24 A 26 A 28 and A 30 .

[0163] Face number A4 A6 A8 A10 A12 A14 A16 S1 -6.5614E-01 -1.8638E-01 -4.7951E-02 -1.0713E-02 -2.3772E-03 -1.0521E-03 -6.0925E-04 S2 2.4225E-01 -3.8363E-02 4.1217E-03 3.2936E-03 -6.7347E-04 4.5510E-04 -2.0104E-04 S3 1.6136E-01 5.6083E-02 -1.3810E-03 -5.5245E-04 -2.9794E-03 -1.5281E-03 -7.3607E-04 S4 -3.2082E-01 5.3212E-02 -1.7368E-02 5.0789E-03 -2.3308E-03 2.0746E-04 -1.5585E-04 S5 4.7830E-01 -5.7245E-02 3.1643E-02 -6.2878E-03 3.3575E-03 -6.1125E-04 2.1004E-04 S6 2.6613E-01 -3.2725E-02 9.2136E-03 -2.1203E-03 2.6775E-04 3.7684E-04 7.1154E-05 S7 -6.9313E-02 -1.8487E-02 -3.0203E-03 -1.8418E-03 -3.3585E-04 1.1686E-03 1.3358E-05 S8 4.5372E-02 4.7466E-02 1.0283E-02 1.0322E-03 -9.2160E-04 1.3153E-03 -8.7728E-05 S9 -8.9708E-01 4.7410E-02 -1.1216E-03 -5.6933E-03 -2.9061E-03 1.9687E-04 -6.1023E-04 S10 -8.2997E-01 1.8890E-02 1.1437E-03 -2.9874E-03 -1.1358E-03 -4.4841E-04 -4.9702E-04 S11 -4.2456E-01 -2.4966E-02 -2.3926E-03 3.1549E-03 1.5301E-03 7.5253E-04 -6.0875E-05 S12 -1.0172E+00 6.0534E-02 -1.1532E-02 9.1434E-03 3.3457E-03 2.7177E-03 9.3050E-05 S13 -1.9986E+00 1.3529E-01 1.4564E-02 9.8475E-03 4.1369E-03 2.4584E-03 -1.5500E-03 S14 -1.6915E+00 1.5417E-01 -5.2102E-03 1.3466E-02 2.0919E-04 1.5186E-03 -1.2287E-03 S15 -1.6179E+00 5.8808E-01 -2.3298E-01 1.2780E-01 -5.2241E-02 2.7579E-02 -1.0030E-02 S16 -2.8492E+00 5.2648E-01 -2.5018E-01 1.2945E-01 -5.2394E-02 3.0417E-02 -8.1832E-03 Face number A18 A20 A22 A24 A26 A28 A30 S1 -3.8808E-04 -1.9838E-04 -1.0044E-04 -3.0021E-05 -1.4955E-05 7.2164E-06 -1.4395E-07 S2 -2.3231E-05 -3.2378E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S3 -4.1355E-04 -1.3257E-04 -2.4408E-05 4.1857E-05 3.0070E-05 2.4728E-05 0.0000E+00 S4 6.4117E-05 5.3187E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S5 6.3855E-05 2.5343E-05 2.8014E-05 -6.0199E-06 6.4588E-06 -2.3100E-06 0.0000E+00 S6 7.0800E-05 -2.5679E-05 -8.3760E-06 -1.7988E-05 -7.4741E-06 -7.7350E-06 0.0000E+00 S7 -7.7891E-05 -1.3898E-04 -1.5026E-05 3.5564E-05 5.8236E-06 1.1499E-05 0.0000E+00 S8 1.8341E-04 -1.6173E-04 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S9 1.5026E-04 -1.3909E-04 6.3722E-05 -6.1661E-07 1.5373E-05 2.9277E-07 0.0000E+00 S10 -1.3150E-04 -7.6103E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S11 -1.7409E-04 -1.6340E-04 -8.7502E-05 -2.8256E-05 -3.7041E-06 9.8724E-06 0.0000E+00 S12 3.1110E-04 -5.5604E-05 2.6684E-05 -2.2355E-05 0.0000E+00 0.0000E+00 0.0000E+00 S13 1.5025E-03 7.2999E-04 1.1472E-05 -1.7751E-04 -5.7944E-05 -6.0618E-06 -1.9403E-05 S14 2.1218E-03 2.5425E-04 -6.0275E-06 2.8127E-05 2.7804E-04 2.3589E-04 7.9956E-05 S15 2.8811E-03 -2.7773E-03 3.6081E-04 4.8453E-05 3.6385E-04 6.6197E-05 -1.8760E-04 S16 5.1718E-03 -1.9146E-03 4.2833E-04 -9.3009E-04 -1.1373E-04 -5.5997E-05 0.0000E+00

[0164] Table 12

[0165] Figure 8a The on-axis chromatic aberration curve of the optical imaging system of Embodiment 4 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 8b The astigmatism curves of the optical imaging system of Example 4 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 8c The distortion curves of the optical imaging system of Example 4 are shown, which represent the distortion magnitude values ​​corresponding to different image heights. Figure 8d The magnification chromatic aberration curve of the optical imaging system of Embodiment 4 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the lens. According to Figures 8a to 8d As shown, the optical imaging system given in Example 4 can achieve good imaging quality. Specific Implementation Example 5

[0167] Figure 9 This is a schematic diagram of the lens group structure of embodiment 5 of the optical imaging system of the present invention. The optical imaging system includes, in sequence from the object side to the image side along the optical axis: aperture stop STO, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, seventh lens E7, seventh lens E8, filter E9 and imaging surface S19.

[0168] The first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has negative optical power, with its object-side surface S5 being convex and its image-side surface S6 being concave. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being concave. The sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being concave. The seventh lens E7 has positive optical power, with its object-side surface S13 being convex and its image-side surface S14 being concave. The eighth lens E8 has positive optical power, with its object-side surface S15 being convex and its image-side surface S16 being concave. The filter E9 has an object-side surface S17 and an image-side surface S18. Light from the object passes sequentially through the surfaces S1 to S19 and is finally imaged on the imaging surface S19.

[0169] Table 13 shows the basic parameters of the optical imaging system in Example 5, where the units for radius of curvature, thickness, and focal length are all millimeters (mm).

[0170]

[0171] Table 13

[0172] As shown in Table 14, in Example 5, the total effective focal length of the optical imaging system is f = 9.13 mm, the distance TTL from the object side surface S1 of the first lens E1 to the imaging surface S19 of the optical imaging system on the optical axis is 10.55 mm, and half the diagonal length of the effective pixel area on the imaging surface S19 is ImgH = 3.31 mm. Half the maximum field of view of the optical imaging lens is Semi-FOV = 19.6°.

[0173]

[0174] Table 14

[0175] In Example 5, the object-side surface and image-side surface of any one of the lenses from the first lens E1 to the eighth lens E8 are aspherical. Table 15 shows the higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror S1-S16 in Example 5. 10 A 12 A 14 A 16 A 18 A 20 A 22 A 24 A 26 A 28 and A 30 .

[0176]

[0177]

[0178] Table 15

[0179] Figure 10a The on-axis chromatic aberration curve of the optical imaging system of Embodiment 5 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 10b The astigmatism curves of the optical imaging system of Example 5 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 10c The distortion curves of the optical imaging system of Example 5 are shown, which represent the distortion magnitude values ​​corresponding to different image heights. Figure 10d The magnification chromatic aberration curve of the optical imaging system of Embodiment 5 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the lens. According to Figures 10a to 10d As shown, the optical imaging system given in Example 5 can achieve good imaging quality. Specific Implementation Example 6

[0181] Figure 11 This is a schematic diagram of the lens group structure of embodiment 6 of the optical imaging system of the present invention. The optical imaging system includes, in sequence from the object side to the image side along the optical axis: aperture stop STO, first lens E1, second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, seventh lens E7, seventh lens E8, filter E9 and imaging surface S19.

[0182] The first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being convex. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has negative optical power, with its object-side surface S5 being convex and its image-side surface S6 being concave. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being concave. The sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being concave. The seventh lens E7 has positive optical power, with its object-side surface S13 being convex and its image-side surface S14 being concave. The eighth lens E8 has negative optical power, with its object-side surface S15 being convex and its image-side surface S16 being concave. The filter E9 has an object-side surface S17 and an image-side surface S18. Light from the object passes sequentially through the surfaces S1 to S19 and is finally imaged on the imaging surface S19.

[0183] Table 16 shows the basic parameters of the optical imaging system of Example 6, where the units for radius of curvature, thickness, and focal length are all millimeters (mm).

[0184]

[0185]

[0186] Table 16

[0187] As shown in Table 17, in Example 6, the total effective focal length of the optical imaging system is f = 9.13 mm, the distance TTL from the object side surface S1 of the first lens E1 to the imaging surface S19 of the optical imaging system on the optical axis is 10.55 mm, and half the diagonal length of the effective pixel area on the imaging surface S19 is ImgH = 3.33 mm. Half the maximum field of view of the optical imaging lens is Semi-FOV = 19.7°.

[0188]

[0189] Table 17

[0190] In Example 6, the object-side surface and image-side surface of any one of the lenses from the first lens E1 to the eighth lens E8 are aspherical. Table 18 shows the higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror S1-S16 in Example 6. 10 A 12 A 14 A 16 A 18 A 20 A 22 A 24 A 25 A 28 and A 30 .

[0191]

[0192]

[0193] Table 18

[0194] Figure 12a The on-axis chromatic aberration curve of the optical imaging system of Embodiment 6 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 12b The astigmatism curves of the optical imaging system of Example 6 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 12c The distortion curves of the optical imaging system of Example 6 are shown, representing the distortion magnitude values ​​corresponding to different image heights. Figure 12d The magnification chromatic aberration curve of the optical imaging system of Embodiment 6 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the lens. According to Figures 12a to 12d As shown, the optical imaging system given in Example 6 can achieve good imaging quality.

[0195] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, improvements, or equivalent substitutions made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An optical imaging system, characterized in that, The optical imaging system has eight lenses with optical power, and the optical imaging system includes, in sequence from the object side to the image side along the optical axis: Aperture; A first lens with positive optical power has a convex object-side surface and a convex image-side surface; A second lens with positive optical power has a convex object-side surface and a concave image-side surface; The third lens with negative optical power has a concave image-side surface; The fourth lens with optical power has a convex object side and a concave image side. The fifth lens with optical power has a convex object side and a concave image side. The sixth lens, which has optical power, has a convex object-side surface and a concave image-side surface. A seventh lens with positive optical power has a convex object-side surface and a concave image-side surface; and The eighth lens, which has optical power, has a concave image-side surface; The eighth lens has positive optical power, and the fourth, fifth, and sixth lenses have positive optical power; or the eighth lens has negative optical power, and at most one of the fourth, fifth, and sixth lenses has negative optical power. Wherein, the effective focal length f1 of the first lens and the effective focal length f2 of the second lens satisfy: 2.0 < f2 / f1 ≤ 2.

54.

2. The optical imaging system according to claim 1, characterized in that: The axial distance TTL from the object side of the first lens to the imaging plane The value of ImgH, which is half the diagonal length of the effective pixel area on the imaging plane, satisfies: 3.14≤TTL / ImgH≤3.

2.

3. The optical imaging system according to claim 1, characterized in that: The effective focal length f of the optical imaging system and the entrance pupil diameter EPD of the optical imaging system satisfy: f / EPD = 1.

1.

4. The optical imaging system according to claim 1, characterized in that: Half of the maximum field of view of the optical imaging system Semi- The field of view (FOV) satisfies: 19° ≤ Semi-FOV ≤ 19.7°.

5. The optical imaging system according to claim 1, characterized in that: The effective focal length f3 of the third lens and the effective focal length f of the optical imaging system satisfy: -0.64≤f3 / f≤-0.

56.

6. The optical imaging system according to claim 1, characterized in that: The radius of curvature R3 of the object side of the second lens and the radius of curvature R4 of the image side of the second lens satisfy: 2.43≤(R4+R3) / (R4-R3)≤2.

73.

7. The optical imaging system according to claim 1, characterized in that: The radius of curvature R6 of the image side of the third lens and the radius of curvature R7 of the object side of the fourth lens satisfy: 3.62≤(R7+R6) / (R7-R6)≤4.

88.

8. The optical imaging system according to claim 1, characterized in that: The radius of curvature R8 of the image side of the fourth lens and the radius of curvature R9 of the object side of the fifth lens satisfy: 1.91≤(R8+R9) / (R8-R9)≤3.

44.

9. The optical imaging system according to claim 1, characterized in that: The radius of curvature R10 of the image side of the fifth lens and the radius of curvature R11 of the object side of the sixth lens satisfy: 2.95≤R11 / R10≤7.

0.

10. The optical imaging system according to claim 1, characterized in that: The radius of curvature R12 of the image side of the sixth lens and the radius of curvature R14 of the image side of the seventh lens satisfy: 1.57≤R12 / R14≤4.

43.

11. The optical imaging system according to claim 1, characterized in that: The radius of curvature R13 of the object side of the seventh lens and the radius of curvature R16 of the image side of the eighth lens satisfy: 0.91≤R16 / R13≤1.

79.

12. The optical imaging system according to claim 1, characterized in that: The center thickness CT1 of the first lens on the optical axis and the center thickness CT8 of the eighth lens on the optical axis satisfy: 4.09≤CT1 / CT8≤10.

25.

13. The optical imaging system according to claim 1, characterized in that: The center thickness CT2 of the second lens on the optical axis and the center thickness CT7 of the seventh lens on the optical axis satisfy: 2.45≤CT2 / CT7≤3.

37.

14. The optical imaging system according to claim 1, characterized in that: The air gap T56 between the fifth and sixth lenses on the optical axis and the air gap T78 between the seventh and eighth lenses on the optical axis satisfy the following condition: 1.68 ≤ T56 / T78 ≤ 3.

5.

15. The optical imaging system according to claim 1, characterized in that: The air gap T34 between the third and fourth lenses on the optical axis and the air gap T67 between the sixth and seventh lenses on the optical axis satisfy the following condition: 1.5 < T34 / T67 ≤ 1.

97.

16. The optical imaging system according to claim 1, characterized in that: The Abbe number V1 of the first lens and the Abbe number V2 of the second lens satisfy: V1 = V2.

17. The optical imaging system according to claim 1, characterized in that: The Abbe number V1 of the first lens and the Abbe number V3 of the third lens satisfy: V1-V3=36.

9.

18. The optical imaging system according to claim 1, characterized in that: The Abbe number V7 of the seventh lens and the Abbe number V8 of the eighth lens satisfy: V8-V7=18.2.

Images