Optical imaging system

Abstract

The application discloses an optical imaging system, which comprises: a lens group sequentially comprising 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 along an optical axis from an object side to an image side; a plurality of spacer elements, comprising a seventh spacer element disposed on an image side surface of the seventh lens and at least partially in contact with the seventh lens, wherein the maximum thickness of the seventh spacer element is greater than the maximum thickness of other spacer elements in the plurality of spacer elements; and a lens barrel for accommodating the lens group and the plurality of spacer elements, a side wall of the seventh spacer element being at least partially in contact with the lens barrel; the distance L of the front end surface of the lens barrel close to the object side to the rear end surface of the lens barrel close to the image side along the optical axis, the outer diameter D0m of the rear end surface of the lens barrel close to the image side, the inner diameter d0m of the rear end surface of the lens barrel close to the image side, and the distance TD of the object side surface of the first lens to the image side surface of the eighth lens on the optical axis satisfy: [L / (D0m / 2)+TD / (d0m / 2)] / 2<1.5.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical elements, in particular to an optical imaging system. BACKGROUND

[0002] With the popularity of mobile phones in daily life, people not only have higher and higher requirements for the imaging quality of lenses, but also strengthen the requirements for the appearance of mobile phones, so that the ultra-thin large-aperture mobile phone lens gradually becomes the development trend of the industry. However, the ultra-thin large-aperture lens usually has a limit on the barrel size, especially for multi-piece imaging lenses, which are difficult to design. For example, for an eight-piece ultra-thin large-aperture imaging lens, the increase in the number of lens pieces makes it difficult to reasonably achieve the demand for thinner lenses, and the size of the rear end of the barrel is difficult to control, which makes it difficult to better achieve the characteristics of a larger aperture. At the same time, when the rear end structure of the imaging lens is not reasonably designed, it is easy to cause problems such as poor optical transmission, unreasonable space matching, and unattractive appearance, thereby affecting the overall quality of the lens.

[0003] Therefore, how to make the optical imaging system meet the requirements of ultra-thin and miniaturization while ensuring the rationality of the structure, thereby reducing the influence of the rear end of the barrel on the realization of the characteristics of ultra-thin and large-aperture imaging, and improving the imaging quality, is one of the key research topics for designers. SUMMARY

[0004] The present application provides an optical imaging system, which comprises: a lens group comprising, in order from the object side to the image side along the optical axis, 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 the first lens, the third lens, the fifth lens, and the seventh lens have positive refractive power, and the second lens, the fourth lens, the sixth lens, and the eighth lens have negative refractive power; a plurality of spacer elements, comprising a seventh spacer element disposed on the image side of the seventh lens and at least partially in contact with the seventh lens, wherein the maximum thickness of the seventh spacer element along the optical axis is greater than the maximum thickness of other spacer elements in the plurality of spacer elements along the optical axis; and a barrel for accommodating the lens group and the plurality of spacer elements, the side wall of the seventh spacer element being at least partially in contact with the barrel; the distance L along the optical axis from the front end face of the barrel close to the object side to the rear end face of the barrel close to the image side, the outer diameter D0m of the rear end face of the barrel close to the image side, the inner diameter d0m of the rear end face of the barrel close to the image side, and the distance TD on the optical axis from the object side face of the first lens to the image side face of the eighth lens satisfy: [L / (D0m / 2)+TD / (d0m / 2)] / 2<1.5.

[0005] In one embodiment, the barrel has a plurality of outer diameters, the plurality of outer diameters having different size values in a direction perpendicular to the optical axis, and the outer diameter of the front end face of the barrel close to the object side is smaller than the outer diameter of the rear end face of the barrel close to the image side.

[0006] In one embodiment, the plurality of spacer elements further comprises a sixth spacer element disposed on the image side of the sixth lens and at least partially in contact with the sixth lens; wherein an outer diameter D7s of the object side surface of the seventh spacer element, an outer diameter D6s of the object side surface of the sixth spacer element, a central thickness CT7 of the seventh lens in the optical axis direction, and an air separation T78 of the seventh lens and the eighth lens in the optical axis direction satisfy: 5.0 < (D7s + D6s) / (CT7 + T78) < 8.0.

[0007] In one embodiment, the plurality of spacer elements further comprises a sixth spacer element disposed on the image side of the sixth lens and at least partially in contact with the sixth lens; wherein an inner diameter d6s of the object side surface of the sixth spacer element, a maximum thickness CP6 of the sixth spacer element in the optical axis direction, an inner diameter d7s of the object side surface of the seventh spacer element, a maximum thickness CP7 of the seventh spacer element in the optical axis direction, a central thickness CT7 of the seventh lens in the optical axis direction, and a central thickness CT8 of the eighth lens in the optical axis direction satisfy: 6.0 < [(d6s + d7s) / (CP6 + CP7)] / (CT7 / CT8) < 9.0.

[0008] In one embodiment, the plurality of spacer elements further comprises a second spacer element disposed on the image side of the second lens and at least partially in contact with the second lens, wherein an outer diameter D2s of the object side surface of the second spacer element, an inner diameter d2s of the object side surface of the second spacer element, a maximum thickness CP2 of the second spacer element in the optical axis direction, and a central thickness CT2 of the second lens in the optical axis direction satisfy: 3.0 < (D2s - d2s) / (CT2 - CP2) < 10.0.

[0009] In one embodiment, the plurality of spacer elements further comprises a first spacer element disposed on the image side of the first lens and at least partially in contact with the first lens, wherein an outer diameter D1s of the object side surface of the first spacer element, an inner diameter d1s of the object side surface of the first spacer element, a maximum thickness CP1 of the first spacer element in the optical axis direction, and a central thickness CT1 of the first lens in the optical axis direction satisfy: 0 < (D1s - d1s) / (CT1 - CP1) < 2.0.

[0010] In one embodiment, the object side surface and the image side surface of each of the first lens, the second lens, and the third lens have a concave-convex opposite surface shape.

[0011] In one embodiment, the plurality of spacer elements further comprises a first spacer element disposed on the image side of the first lens and in at least partial contact with the first lens, a second spacer element disposed on the image side of the second lens and in at least partial contact with the second lens, a third spacer element disposed on the image side of the third lens and in at least partial contact with the third lens, a fourth spacer element disposed on the image side of the fourth lens and in at least partial contact with the fourth lens, a fifth spacer element disposed on the image side of the fifth lens and in at least partial contact with the fifth lens, and a sixth spacer element disposed on the image side of the sixth lens and in at least partial contact with the sixth lens, the optical imaging system satisfies: -50.0 < (fi+fj) / (CPi+EPij) < 150.0, wherein i = 1, 2, 3, 4, or 5, j = i+1; wherein, when i is 1, j is 2, fi represents the effective focal length of the first lens, f2 represents the effective focal length of the second lens, CP1 represents the maximum thickness of the first spacer element along the optical axis direction, EP12 represents the air gap between the first spacer element and the second spacer element along the optical axis direction; when i is 2, j is 3, f2 represents the effective focal length of the second lens, f3 represents the effective focal length of the third lens, CP2 represents the maximum thickness of the second spacer element along the optical axis direction, EP23 represents the air gap between the second spacer element and the third spacer element along the optical axis direction; when i is 3, j is 4, f3 represents the effective focal length of the third lens, f4 represents the effective focal length of the fourth lens, CP3 represents the maximum thickness of the third spacer element along the optical axis direction, EP34 represents the air gap between the third spacer element and the fourth spacer element along the optical axis direction; when i is 4, j is 5, f4 represents the effective focal length of the fourth lens, f5 represents the effective focal length of the fifth lens, CP4 represents the maximum thickness of the fourth spacer element along the optical axis direction, EP45 represents the air gap between the fourth spacer element and the fifth spacer element along the optical axis direction; when i is 5, j is 6, f5 represents the effective focal length of the fifth lens, f6 represents the effective focal length of the sixth lens, CP5 represents the maximum thickness of the fifth spacer element along the optical axis direction, EP56 represents the air gap between the fifth spacer element and the sixth spacer element along the optical axis direction.

[0012] In one embodiment, the plurality of spacer elements further comprises a second spacer element disposed on the image side of the second lens and in at least partial contact with the second lens, and a third spacer element disposed on the image side of the third lens and in at least partial contact with the third lens; wherein the outer diameter of the object side surface of the second spacer element D2s, the outer diameter of the object side surface of the third spacer element D3s, the curvature radius of the object side surface of the second lens R3, the curvature radius of the image side surface of the second lens R4, the curvature radius of the object side surface of the third lens R5, and the curvature radius of the image side surface of the third lens R6 satisfy: 1.0 < (D2s / (R3-R4)+D3s / (R5-R6) < 7.0.

[0013] In one embodiment, the plurality of spacer elements further includes a first spacer element disposed on the image side of the first lens and in at least partial contact with the first lens, a second spacer element disposed on the image side of the second lens and in at least partial contact with the second lens, a third spacer element disposed on the image side of the third lens and in at least partial contact with the third lens, a fourth spacer element disposed on the image side of the fourth lens and in at least partial contact with the fourth lens, a fifth spacer element disposed on the image side of the fifth lens and in at least partial contact with the fifth lens, and a sixth spacer element disposed on the image side of the sixth lens and in at least partial contact with the sixth lens, wherein a distance EP01 on the optical axis from a front end surface of the barrel near the object side to an object side surface of the first spacer element, a sum ΣEP of air spacings along the optical axis between any two adjacent spacer elements among the first spacer element and the seventh spacer element, an air spacing T12 on the optical axis between the first lens and the second lens, and a sum ∑AT of air spacings on the optical axis between any two adjacent lenses among the first lens and the eighth lens satisfy: EP01 / ΣEP+T12 / ∑AT<1.0.

[0014] In one embodiment, the object side surface of the fourth lens is convex, and the image side surface of the fourth lens is concave; and the object side surface of the fifth lens is convex, and the image side surface of the fifth lens is concave.

[0015] In one embodiment, the plurality of spacer elements further includes a fourth spacer element disposed on the image side of the fourth lens and in at least partial contact with the fourth lens, wherein an outer diameter D4s of an object side surface of the fourth spacer element, an inner diameter d4s of the object side surface of the fourth spacer element, a curvature radius R7 of the object side surface of the fourth lens, a curvature radius R8 of the image side surface of the fourth lens, an effective focal length f4 of the fourth lens, and an effective focal length f5 of the fifth lens satisfy: -5.0<(f4+f5) / (R7 / D4s+R8 / d4s)<0 or 0<(f4+f5) / (R7 / D4s+R8 / d4s)<2.0.

[0016] In one embodiment, the plurality of spacer elements further includes a fifth spacer element disposed on the image side of the fifth lens and in at least partial contact with the fifth lens; wherein an outer diameter D5s of an object side surface of the fifth spacer element, an inner diameter d5s of the object side surface of the fifth spacer element, a curvature radius R9 of the object side surface of the fifth lens, a curvature radius R10 of the image side surface of the fifth lens, an effective focal length f4 of the fourth lens, and an effective focal length f5 of the fifth lens satisfy: 0<[(D5s-d5s) / (R9-R10)]x100 / (f5 / f4)<15.0.

[0017] In one embodiment, the object side surface of the sixth lens is concave, and the image side surface of the sixth lens is convex.

[0018] In one embodiment, the plurality of spacer elements further comprises a sixth spacer element disposed on the image side of the sixth lens and at least partially in contact with the sixth lens; wherein the outer diameter D6s of the object side surface of the sixth spacer element, the inner diameter d6s of the object side surface of the sixth spacer element, the radius of curvature R11 of the object side surface of the sixth lens, the radius of curvature R12 of the image side surface of the sixth lens and the effective focal length f6 of the sixth lens satisfy: 0 < (R12-R11) x (D6s-d6s) / f6 < 10.0.

[0019] In one embodiment, the effective focal length f of the optical imaging system, the entrance pupil diameter EPD of the optical imaging system and the inner diameter d0s of the front end surface of the barrel near the object side satisfy: (f / EPD+f / d0s) / 2 < 1.7.

[0020] In one embodiment, the object side surface of the seventh lens is convex, and the image side surface of the seventh lens is convex; the eighth lens has negative refractive power, and the image side surface of the eighth lens is concave.

[0021] In one embodiment, the plurality of spacer elements further comprises a fifth spacer element disposed on the image side of the fifth lens and at least partially in contact with the fifth lens and a sixth spacer element disposed on the image side of the sixth lens and at least partially in contact with the sixth lens; wherein the optical imaging system satisfies: -5.0 < (CTx+CPx) x 100 / (Ry-Rz) < 0 or 0 < (CTx+CPx) x 100 / (Ry-Rz) < 30.0, x = 5, 6 or 7, y = 2x-1, z = 2i; wherein when x is 5, y = 9, z = 10, CT5 represents the center thickness of the fifth lens on the optical axis, CP5 represents the maximum thickness of the fifth spacer element along the optical axis direction, R9 represents the radius of curvature of the object side surface of the fifth lens, and R10 represents the radius of curvature of the image side surface of the fifth lens; when x is 6, y = 11, z = 12, CT6 represents the center thickness of the sixth lens on the optical axis, CP6 represents the maximum thickness of the sixth spacer element along the optical axis direction, R11 represents the radius of curvature of the object side surface of the sixth lens, and R12 represents the radius of curvature of the image side surface of the sixth lens; when x is 7, y = 13, z = 14, CT7 represents the center thickness of the seventh lens on the optical axis, CP7 represents the maximum thickness of the seventh spacer element along the optical axis direction, R13 represents the radius of curvature of the object side surface of the seventh lens, and R14 represents the radius of curvature of the image side surface of the seventh lens.

[0022] In one embodiment, the optical imaging system further comprises an auxiliary spacer element disposed on the image side of the seventh spacer element and at least partially in contact with the seventh spacer element, wherein the radius of curvature R15 of the object side surface of the eighth lens, the inner diameter d7bm of the image side surface of the auxiliary spacer element, the effective focal length f of the optical imaging system and the effective focal length f8 of the eighth lens satisfy: 0 < |(R15 / d7bm) / (f8 / f)| < 55.0.

[0023] In one embodiment, the optical imaging system further comprises an auxiliary spacer element disposed on the image side of the seventh spacer element and at least partially in contact with the seventh spacer element, wherein a radius of curvature R16 of the image side of the eighth lens, an outer diameter D7bm of the image side of the auxiliary spacer element, an effective focal length f of the optical imaging system, and an effective focal length f8 of the eighth lens satisfy: -10.0 < (D7bm / R16) x (f / f8) < 0.

[0024] In one embodiment, a distance along the optical axis from a center of the effective diameter of the image side of the second lens to the rear end surface of the lens barrel near the image side is greater than a distance along the optical axis from an edge of the effective diameter of the image side of the second lens to the rear end surface of the lens barrel near the image side.

[0025] The optical imaging system provided in the application is composed of a plurality of imaging lenses, a plurality of spacer elements, and a lens barrel. The span of each gear of the lenses cooperating with the lens barrel is relatively uniform. In the scheme, the signs of the optical powers of two adjacent lenses are opposite. By reasonably matching the surface type and the optical power, the light converging capability is enhanced. The lenses have good processing feasibility, and the lens can be thinned. By reasonably designing the relevant dimensions of the rear end surface of the lens barrel, space is provided for the design of the shape of the lens, and more optical fiber transmission space is provided. This also helps to improve the imaging quality of the ultra-thin and large image surface imaging lens. At the same time, a thick spacer element is added at the position between the last two lenses with a large interval, and a thick spacer ring is used to assist the bearing of the lens barrel. This helps to reduce the deformation amount of the imaging system and the change amount of the air gap, reduces the influence of the assembly step difference on the performance, ensures the assembly stability, and improves the overall quality of the lens. BRIEF DESCRIPTION OF DRAWINGS

[0026] Other features, objects, and advantages of the application will become more apparent from the following detailed description of non-limiting embodiments made with reference to the following drawings:

[0027] Figure 1 The structural arrangement diagram of an optical imaging system according to the application and the schematic diagram of part of the parameters are shown;

[0028] Figures 2A to 2C The structural schematic diagram of an optical imaging system according to Embodiment 1 of the application is shown;

[0029] Figures 3A to 3D The on-axis chromatic aberration curve, the astigmatism curve, the distortion curve, and the magnification chromatic aberration curve of the optical imaging system according to Embodiment 1 of the application are respectively shown;

[0030] Figures 4A to 4C The structural schematic diagram of an optical imaging system according to Embodiment 2 of the application is shown;

[0031] Figures 5A to 5DOn-axis chromatic aberration curves, astigmatism curves, distortion curves, and magnification chromatic aberration curves of the optical imaging system according to Embodiment 2 of the present application are shown.

[0032] Figures 6A to 6C A structural schematic diagram of the optical imaging system according to Embodiment 3 of the present application is shown.

[0033] Figures 7A to 7D On-axis chromatic aberration curves, astigmatism curves, distortion curves, and magnification chromatic aberration curves of the optical imaging system according to Embodiment 3 of the present application are shown. DETAILED DESCRIPTION

[0034] For a better understanding of the present application, various aspects of the present application will be described in more detail below with reference to the accompanying drawings. It is to be noted that the detailed description is only a description of exemplary embodiments of the present application and is in no way intended to limit the scope of the present application. Throughout the specification, like reference numerals refer to like elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0035] It should be noted that, in the present specification, the expressions first, second, third, etc. are merely used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, the first lens discussed below can also be referred to as the second lens or the third lens without departing from the teachings of the present application.

[0036] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shape of the spherical surface or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical surface or aspherical surface is not limited to the shape of the spherical surface or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn strictly to scale.

[0037] In the present specification, the paraxial region refers to a region near the optical axis. If a lens surface is convex and the position of the convex surface is not specified, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the position of the concave surface is not specified, it means that the lens surface is concave at least in the paraxial region. The surface of each lens that is close to the object is referred to as the object side surface of the lens, and the surface of each lens that is close to the imaging plane is referred to as the image side surface of the lens.

[0038] It should also be understood that the words "comprise", "comprising", "include", "including", and / or "has", "having", when used in this specification, specify the presence of stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or groups thereof. In addition, when terms such as "at least one of", "one or more of", or "at least an of" are used in the detailed description or the claims, these terms are intended to mean that the description or claim includes at least one of the listed features, elements, or components, but not excluding others. In addition, when describing the embodiments of the present application, the word "may" means "one or more embodiments of the present application." Also, the word "exemplary" is intended to mean an example or an illustration.

[0039] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0040] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The following embodiments only express several embodiments of the present application, which are described in detail and specifically, but can not be understood as limitations to the scope of the patent of the present application. It should be noted that, for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application, for example, the lens group (i.e. the first lens to the eighth lens), the lens barrel and the spacer element in each embodiment of the present application can be combined arbitrarily, which is not limited to the combination of the lens group, the lens barrel, the spacer element and the like in the embodiment.

[0041] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. Among them, Figure 1 The structural arrangement diagram of an optical imaging system according to the present application and the schematic diagram of part of the parameters are shown. Those skilled in the art should understand that some parameters of lenses often used in the art, such as the center thickness CT7 of the seventh lens on the optical axis, are not shown in the drawings, Figure 1 Figure 1 Only part of the parameters of the lens barrel and the spacer element of an optical imaging system according to the present application are shown exemplarily, so as to better understand the present application, such as Figure 1 ​As shown, EP01 represents the distance on the optical axis from the front end surface of the barrel close to the object side to the object side surface of the first spacer element, EP12 represents the air interval between the first spacer element and the second spacer element in the direction of the optical axis, EP23 represents the interval distance of the second spacer element and the third spacer element in the direction of the optical axis, EP56 represents the air interval between the fifth spacer element and the sixth spacer element in the direction of the optical axis, CP1 represents the maximum thickness of the first spacer element in the direction of the optical axis, CP2 represents the maximum thickness of the second spacer element in the direction of the optical axis, CP7 represents the maximum thickness of the seventh spacer element in the direction of the optical axis, L represents the distance along the optical axis from the front end surface of the barrel close to the object side to the rear end surface of the barrel close to the image side (i.e. the total length of the barrel in the direction of the optical axis), d0s is the inner diameter of the front end surface of the barrel close to the object side, d1s is the inner diameter of the object side surface of the first spacer element, D1s is the outer diameter of the object side surface of the first spacer element, d2s is the inner diameter of the object side surface of the second spacer element, D2s is the outer diameter of the object side surface of the second spacer element, D3s is the outer diameter of the object side surface of the third spacer element, d6s is the inner diameter of the object side surface of the sixth spacer element, D6s is the outer diameter of the object side surface of the sixth spacer element, d7s is the inner diameter of the object side surface of the seventh spacer element, D7s is the outer diameter of the object side surface of the seventh spacer element, D0m is the outer diameter of the rear end surface of the barrel close to the image side, d0m is the inner diameter of the rear end surface of the barrel close to the image side.

[0042] The features, principles, and other aspects of the present application are described in detail below.

[0043] As shown in FIG. 1, the optical imaging system according to an exemplary embodiment of the present application includes a barrel P0 and a plurality of lens groups and a plurality of spacer elements disposed within the barrel P0. The plurality of lens groups includes a first lens group G1, a second lens group G2, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. 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 auxiliary spacer element P7b. The first lens group G1 includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4. The second lens group G2 includes a fifth lens E5. The third lens group G3 includes a sixth lens E6. The fourth lens group G4 includes a seventh lens E7. The fifth lens group G5 includes an eighth lens E8. Figures 2A to 2C Figures 4A to 4C As shown in FIG. 1, the optical imaging system according to an exemplary embodiment of the present application includes a barrel P0 and a plurality of lens groups and a plurality of spacer elements disposed within the barrel P0. The plurality of lens groups includes a first lens group G1, a second lens group G2, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. 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 auxiliary spacer element P7b. The first lens group G1 includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4. The second lens group G2 includes a fifth lens E5. The third lens group G3 includes a sixth lens E6. The fourth lens group G4 includes a seventh lens E7. The fifth lens group G5 includes an eighth lens E8. Figures 6A to 6C As shown in FIG. 1, the optical imaging system according to an exemplary embodiment of the present application includes a barrel P0 and a plurality of lens groups and a plurality of spacer elements disposed within the barrel P0. The plurality of lens groups includes a first lens group G1, a second lens group G2, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. 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 auxiliary spacer element P7b. The first lens group G1 includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4. The second lens group G2 includes a fifth lens E5. The third lens group G3 includes a sixth lens E6. The fourth lens group G4 includes a seventh lens E7. The fifth lens group G5 includes an eighth lens E8.

[0044] ​In an example embodiment, the first spacer element is disposed on the image side of the first lens and at least partially contacts the first lens; the second spacer element is disposed on the image side of the second lens and at least partially contacts the second lens; the third spacer element is disposed on the image side of the third lens and at least partially contacts the third lens; the fourth spacer element is disposed on the image side of the fourth lens and at least partially contacts the fourth lens; the fifth spacer element is disposed on the image side of the fifth lens and at least partially contacts the fifth lens; the sixth spacer element is disposed on the image side of the sixth lens and at least partially contacts the sixth lens; and the seventh spacer element is disposed on the image side of the seventh lens and at least partially contacts the seventh lens.

[0045] In an example embodiment, the auxiliary spacer element is disposed on the image side of the seventh spacer element and at least partially contacts the seventh spacer element.

[0046] In an example embodiment, the lens barrel has a plurality of outer diameters, the plurality of outer diameters have different size values in a direction perpendicular to the optical axis, and an outer diameter of a front end surface of the lens barrel close to the object side is smaller than an outer diameter of a rear end surface of the lens barrel close to the image side. Wherein the outer wall of the lens barrel has a plurality of outer diameter size values, the outer diameter of the front end surface of the lens barrel is smaller than the outer diameter of the rear end surface of the lens barrel, which helps to meet the appearance requirements of the lens, ensure the uniformity of the thickness of the lens barrel, meet the processing requirements, ensure that the related dimensions meet the design requirements, and improve the performance yield.

[0047] In an example embodiment, the side wall of the seventh spacer element at least partially contacts the lens barrel, and the maximum thickness of the seventh spacer element in the direction of the optical axis is greater than the maximum thickness of the other spacer elements in the direction of the optical axis. For example, the seventh spacer element disposed between the seventh lens and the eighth lens is a thick spacer element, and the seventh spacer element has at least one surface parallel to the optical axis and at least two surfaces perpendicular to the optical axis, wherein the outer side surface of the seventh spacer element parallel to the optical axis at least partially contacts the lens barrel, and the seventh spacer element and the lens barrel adopt an auxiliary abutting mode, which is beneficial to reduce the deformation amount and the variation amount of the air gap, thereby reducing the influence of the assembly step difference on the performance, further improving the assembly stability, and improving the performance yield.

[0048] In an example embodiment, the optical power of any two adjacent lenses in the lens group has different positive and negative properties, and the surface type and optical power are reasonably matched, which not only ensures good processing feasibility of the lens, but also realizes the ultra-thin design of the lens and provides space for the appearance design of the lens.

[0049] In an example embodiment, the image side surface of the second lens is a concave surface, which can effectively ensure that the chief ray of the optical imaging system has a small incidence angle when incident on the image surface, increase the relative luminance, help to weaken the refractive ability of the lens, and improve the imaging quality of the large image surface lens.

[0050] In the example embodiment, the object side surface and the image side surface of each of the first lens, the second lens and the third lens have opposite convex-concave surface types. For example, the first lens can have positive focal power, the object side surface of which is a convex surface and the image side surface of which is a concave surface; the second lens can have negative focal power, the object side surface of which is a convex surface and the image side surface of which is a concave surface; and the third lens can have positive focal power, the object side surface of which is a concave surface and the image side surface of which is a convex surface. Such a focal power and surface type arrangement is conducive to changing the propagation path of light in the first lens, the second lens and the third lens, thereby further improving the imaging quality of the overall optical imaging system. By reasonably allocating the positive and negative of the focal power of the lenses, the low-order aberration of the optical camera system can be effectively balanced and controlled, and the tolerance sensitivity can be reduced. This helps to improve the processability of the first lens, the second lens and the third lens, and avoids the problem of low performance yield due to poor lens forming.

[0051] In the example embodiment, the fourth lens can have negative focal power, the object side surface of which is a convex surface and the image side surface of which is a concave surface; and the fifth lens can have positive focal power, the object side surface of which is a convex surface and the image side surface of which is a concave surface. Reasonably matching the focal power and surface type of the fourth lens and the fifth lens can effectively increase the refractive power of the fourth lens and the fifth lens, improve the imaging quality of the large image surface lens, and achieve the characteristics of ultra-thin.

[0052] In the example embodiment, the sixth lens can have negative focal power, the object side surface of which is a concave surface and the image side surface of which is a convex surface. By controlling the focal power and surface type of the sixth lens, the aberrations generated by the front-end optics and the rear-end optics of the system can be balanced, and the processability and strength of the lens can be ensured.

[0053] In the example embodiment, the seventh lens has positive focal power, the object side surface of which is a convex surface and the image side surface of which is a convex surface; and the eighth lens has negative focal power, the image side surface of which is a concave surface. Such a focal power and surface type arrangement can effectively ensure that the chief ray of the optical imaging system has a small incidence angle when it is incident on the image surface, increase the relative luminance, and thereby improve the imaging quality.

[0054] In the example embodiment, the distance along the optical axis from the center of the effective diameter of the image side surface of the second lens to the rear end surface of the lens barrel close to the image side is greater than the distance along the optical axis from the edge of the effective diameter of the image side surface of the second lens to the rear end surface of the lens barrel close to the image side. This can effectively ensure that the chief ray of the optical imaging system has a small incidence angle when it is incident on the image surface, increase the relative luminance, help to weaken the refractive power of the lens, and improve the imaging quality of the large image surface lens.

[0055] In the example embodiments, the optical imaging system according to the present application can satisfy: 5.0 < (D7s+D6s) / (CT7+T78) < 8.0, where D6s is the outer diameter of the object side surface of the sixth spacer element, D7s is the outer diameter of the object side surface of the seventh spacer element, T78 is the air gap of the seventh lens and the eighth lens on the optical axis, and CT7 is the center thickness of the seventh lens on the optical axis. More specifically, D6s, D7s, CT7 and T78 can further satisfy: 5.3 < (D7s+D6s) / (CT7+T78) < 7.2. Satisfying 5.0 < (D7s+D6s) / (CT7+T78) < 8.0 is conducive to making the span of each gear of the lens and the lens barrel more uniform, enhancing the light converging ability, and improving the imaging quality of the ultra-thin and large image surface imaging lens. By adding a thick spacer element, i.e., the seventh spacer element, at the position where the last two lenses are spaced apart, this adoption of the thick spacer ring and the lens barrel auxiliary bearing mode helps to reduce the deformation amount and the air gap variation amount of the imaging system, can reduce the influence of the assembly section difference on the performance, ensure the assembly stability, and improve the overall quality of the lens.

[0056] In the example embodiments, the optical imaging system according to the present application can satisfy: 6.0 < [(d6s+d7s) / (CP6+CP7)] / (CT7 / CT8) < 9.0, where d6s is the inner diameter of the object side surface of the sixth spacer element, CP6 is the maximum thickness of the sixth spacer element along the optical axis direction, d7s is the inner diameter of the object side surface of the seventh spacer element, CP7 is the maximum thickness of the seventh spacer element along the optical axis direction, CT7 is the center thickness of the seventh lens on the optical axis, and CT8 is the center thickness of the eighth lens on the optical axis. More specifically, d6s, d7s, CP6, CP7, CT7 and CT8 can further satisfy: 7.2 < [(d6s+d7s) / (CP6+CP7)] / (CT7 / CT8) < 9.0. Satisfying 6.0 < [(d6s+d7s) / (CP6+CP7)] / (CT7 / CT8) < 9.0 is conducive to making the span of each gear of the lens and the lens barrel more uniform, enhancing the light converging ability, and improving the imaging quality of the ultra-thin and large image surface imaging lens. By adding a thick spacer element, i.e., the seventh spacer element, at the position where the last two lenses are spaced apart, this adoption of the thick spacer ring and the lens barrel auxiliary bearing mode helps to reduce the deformation amount and the air gap variation amount of the imaging system, can reduce the influence of the assembly section difference on the performance, ensure the assembly stability, and improve the overall quality of the lens.

[0057] In the example embodiments, the optical imaging system according to the present application can satisfy: [L / (D0m / 2)+TD / (d0m / 2)] / 2<1.5, where L is the distance along the optical axis from the front end surface of the barrel close to the object side to the rear end surface of the barrel close to the image side, D0m is the outer diameter of the rear end surface of the barrel close to the image side, d0m is the inner diameter of the rear end surface of the barrel close to the image side, and TD is the distance on the optical axis from the object side surface of the first lens to the image side surface of the eighth lens. More specifically, L, D0m, TD and d0m can further satisfy: 1.0<[L / (D0m / 2)+TD / (d0m / 2)] / 2<1.3. Satisfying [L / (D0m / 2)+TD / (d0m / 2)] / 2<1.5 is conducive to guaranteeing the performance and appearance of the optical imaging system. Under the condition of the wall thickness of the barrel, the larger the image height of the optical imaging system, the larger the outer diameter D0m of the rear end surface of the barrel, the larger the light transmission space, and the higher the imaging quality of the optical imaging system; the outer diameter D0m of the rear end surface of the barrel and the distance L from the front end surface of the barrel to the rear end surface thereof jointly determine the appearance style of the lens. Under the condition of satisfying the motor adaptation, the larger the appearance adjustment space of the lens, the more beautiful the lens is; by controlling the conditional formula, the size of the rear end of the large-aperture lens and the height of the barrel can be effectively controlled, which is conducive to guaranteeing the size of the large end of the lens and the overall height of the barrel, and helps to realize the characteristics of the ultra-thin lens.

[0058] In the example embodiments, the optical imaging system according to the present application can satisfy: 3.0<(D2s-d2s) / (CT2-CP2)<10.0, where D2s is the outer diameter of the object side surface of the second spacer element, d2s is the inner diameter of the object side surface of the second spacer element, CP2 is the maximum thickness of the second spacer element along the optical axis, and CT2 is the central thickness of the second lens on the optical axis. More specifically, D2s, d2s, CT2 and CP2 can further satisfy: 5.3<(D2s-d2s) / (CT2-CP2)<8.9. Satisfying 3.0<(D2s-d2s) / (CT2-CP2)<10.0 can help to control the central thickness of the second lens, thereby reasonably distributing the optical power and improving the upper limit of the performance of the optical imaging system; on the other hand, the thickness of the second spacer element can be guaranteed, thereby improving the uniformity and overall structural strength of the spacer element, and at the same time, the radial dimension of the spacer element perpendicular to the optical axis can be controlled, thereby blocking the reflected stray light generated by the non-effective radial part of the position of the second lens, thereby improving the overall stray light of the optical imaging system and improving the imaging quality.

[0059] In the example embodiments, the optical imaging system according to the present application can satisfy: 0 < (D1s-d1s) / (CT1-CP1) < 2.0, where D1s is the outer diameter of the object side surface of the first spacer element, d1s is the inner diameter of the object side surface of the first spacer element, CP1 is the maximum thickness of the first spacer element along the optical axis direction, and CT1 is the central thickness of the first lens on the optical axis. More specifically, D1s, d1s, CT1 and CP1 can further satisfy: 0.7 < (D1s-d1s) / (CT1-CP1) < 1.95. Satisfying 0 < (D1s-d1s) / (CT1-CP1) < 2.0, on one hand, helps to control the central thickness of the first lens, so that the optical power can be reasonably distributed, and the upper limit of the performance of the optical imaging system can be improved; on the other hand, the thickness of the first spacer element can be ensured, so that the uniformity of the spacer element and the overall structural strength can be improved, and at the same time, the radial dimension of the spacer element perpendicular to the optical axis can be controlled, so that the reflective stray light generated by the non-effective radial part of the first lens position is blocked, and thus the overall stray light of the optical imaging system can be improved, and the imaging quality can be improved.

[0060] In exemplary embodiments, the optical imaging system according to the present application can satisfy: -50.0 < (fi+fj) / (CPi+EPij) < 150.0, wherein i = 1, 2, 3, 4 or 5, j = i+1; wherein, when i takes 1, j = 2, fi represents the effective focal length of the first lens, f2 represents the effective focal length of the second lens, CP1 represents the maximum thickness of the first spacer element along the optical axis direction, EP12 represents the air gap between the first and second spacer elements along the optical axis direction; when i takes 2, j = 3, f2 represents the effective focal length of the second lens, f3 represents the effective focal length of the third lens, CP2 represents the maximum thickness of the second spacer element along the optical axis direction, EP23 represents the air gap between the second and third spacer elements along the optical axis direction; when i takes 3, j = 4, f3 represents the effective focal length of the third lens, f4 represents the effective focal length of the fourth lens, CP3 represents the maximum thickness of the third spacer element along the optical axis direction, EP34 represents the air gap between the third and fourth spacer elements along the optical axis direction; when i takes 4, j = 5, f4 represents the effective focal length of the fourth lens, f5 represents the effective focal length of the fifth lens, CP4 represents the maximum thickness of the fourth spacer element along the optical axis direction, EP45 represents the air gap between the fourth and fifth spacer elements along the optical axis direction; when i takes 5, j = 6, f5 represents the effective focal length of the fifth lens, f6 represents the effective focal length of the sixth lens, CP5 represents the maximum thickness of the fifth spacer element along the optical axis direction, EP56 represents the air gap between the fifth and sixth spacer elements along the optical axis direction. More specifically, the optical imaging system according to the present application can further satisfy: -40.0 < (fi+fj) / (CPi+EPij) < 137.9, wherein i = 1, 2, 3, 4 or 5, j = i+1. By controlling the thickness of the spacer elements between the lenses, the stability of the assembly and the performance stability are ensured, and in the actual production process, the performance can also be optimized by adjusting the air gap with spacer elements of different thicknesses, the lens edge thickness and the focal length of the lens are reasonably controlled, and the lens and lens effective diameter after assembly can also be prevented from interfering in the optical axis direction, avoiding the occurrence of lens appearance problems and performance abnormalities, improving the appearance and performance yield.

[0061] In exemplary embodiments, the optical imaging system according to the present application can satisfy: 1.0 < (D2s / (R3-R4) + D3s / (R5-R6) < 7.0, where D2s is the outer diameter of the object side surface of the second spacer element, D3s is the outer diameter of the object side surface of the third spacer element, R3 is the curvature radius of the object side surface of the second lens, R4 is the curvature radius of the image side surface of the second lens, R5 is the curvature radius of the object side surface of the third lens, and R6 is the curvature radius of the image side surface of the third lens. More specifically, D2s, R3, R4, D3s, R5 and R6 can further satisfy: 3.3 < (D2s / (R3-R4) + D3s / (R5-R6) < 4.9. Satisfying 1.0 < (D2s / (R3-R4) + D3s / (R5-R6) < 7.0 helps to ensure the machinability of the second lens and the third lens, and also helps to control the convex-concave variation of the surface shape of the second lens and the third lens, to ensure the size and smoothness of the surface shape of the second lens and the third lens, and to improve performance. In addition, the selection of the position of the spacer element helps to ensure that the optical parameters meet the requirements, and also helps to avoid the risk of stray light directly passing from the edge of the effective diameter of the second lens.

[0062] In exemplary embodiments, the optical imaging system according to the present application can satisfy: EP01 / ∑EP + T12 / ∑AT < 1.0, where EP01 is the distance on the optical axis from the front end surface of the lens barrel close to the object side to the object side surface of the first spacer element, ∑EP is the sum of the air spacings along the optical axis between any two adjacent spacer elements among the first spacer element to the seventh spacer element, T12 is the air spacing on the optical axis between the first lens and the second lens, and ∑AT is the sum of the air spacings on the optical axis between any two adjacent lenses among the first lens to the eighth lens. More specifically, EP01, ∑EP, T12 and ∑AT can further satisfy: 0.2 < EP01 / ∑EP + T12 / ∑AT < 0.8. Satisfying EP01 / ∑EP + T12 / ∑AT < 1.0 helps to reasonably use the spacer elements between the lenses, on the one hand to ensure the stability of the spacings and to improve the assembly stability of the lens, thereby improving the performance yield, and on the other hand to effectively ensure the thickness of the front end of the lens barrel by controlling the size of EP01, to prevent the occurrence of flocculent stray light at the sharp corners of the lens barrel.

[0063] In exemplary embodiments, the optical imaging system according to the present application can satisfy: -5.0 < (f4 + f5) / (R7 / D4s + R8 / d4s) < 0 or 0 < (f4 + f5) / (R7 / D4s + R8 / d4s) < 2.0, where D4s is the outer diameter of the object side surface of the fourth spacer element, d4s is the inner diameter of the object side surface of the fourth spacer element, R7 is the curvature radius of the object side surface of the fourth lens, R8 is the curvature radius of the image side surface of the fourth lens, f4 is the effective focal length of the fourth lens, and f5 is the effective focal length of the fifth lens. More specifically, D4s, d4s, R7, R8, f5 and f4 can further satisfy: -4.5 < (f4 + f5) / (R7 / D4s + R8 / d4s) < -1.50 or 0.5 < (f4 + f5) / (R7 / D4s + R8 / d4s) < 1.2. Satisfying -5.0 < (f4 + f5) / (R7 / D4s + R8 / d4s) < 0 or 0 < (f4 + f5) / (R7 / D4s + R8 / d4s) < 2.0 helps to reasonably control the effective focal lengths of the fourth lens and the fifth lens, and effectively increases the refractive power of the fourth lens and the fifth lens; by controlling the conditional expression, it helps to control the curvature radius of the fourth lens, which can reduce the deflection angle of light and improve the imaging quality of the optical system; in addition, it helps to control the inner and outer diameters of the fourth spacer element, which can effectively control the bearing width of the fourth spacer element and effectively block stray light passing from the effective diameter edge of the fourth lens, thereby improving the overall imaging quality.

[0064] In exemplary embodiments, the optical imaging system according to the present application can satisfy: 0 < [(D5s - d5s) / (R9 - R10)] x 100 / (f5 / f4) < 15.0, where D5s is the outer diameter of the object side surface of the fifth spacer element, d5s is the inner diameter of the object side surface of the fifth spacer element, R9 is the curvature radius of the object side surface of the fifth lens, R10 is the curvature radius of the image side surface of the fifth lens, f4 is the effective focal length of the fourth lens, and f5 is the effective focal length of the fifth lens. More specifically, D5s, d5s, R9, R10, f5 and f4 can further satisfy: 1.4 < [(D5s - d5s) / (R9 - R10)] x 100 / (f5 / f4) < 11.6. Satisfying 0 < [(D5s - d5s) / (R9 - R10)] x 100 / (f5 / f4) < 15.0 helps to reasonably control the effective focal lengths of the fourth lens and the fifth lens, and effectively increases the refractive power of the fourth lens and the fifth lens; by controlling the conditional expression, it helps to control the curvature radius of the fifth lens, which can reduce the deflection angle of light and improve the imaging quality of the optical system; in addition, it helps to control the inner and outer diameters of the fifth spacer element, which can effectively control the bearing width of the fifth spacer element and effectively block stray light passing from the effective diameter edge of the fifth lens, thereby improving the overall imaging quality.

[0065] In exemplary embodiments, the optical imaging system according to the present application can satisfy: 0 < (R12-R11) x (D6s-d6s) / f6<10.0, where D6s is an outer diameter of the object side surface of the sixth spacer element, d6s is an inner diameter of the object side surface of the sixth spacer element, R11 is a curvature radius of the object side surface of the sixth lens, R12 is a curvature radius of the image side surface of the sixth lens, and f6 is an effective focal length of the sixth lens. More specifically, R12, R11, D6s, d6s and f6 can further satisfy: 2.2 < (R12-R11) x (D6s-d6s) / f6<7.5. Satisfying 0 < (R12-R11) x (D6s-d6s) / f6<10.0 is conducive to satisfying the structural control requirement, and the difference between the curvature radius R11 of the object side surface of the sixth lens and the curvature radius R12 of the image side surface of the sixth lens can determine the size of the outer diameter of the object side surface of the sixth spacer element, and the difference between the inner and outer diameters of the spacer element determines the width of the annular surface of the object side surface of the spacer element, and overall control can effectively ensure the stray light effect of the spacer element and improve the imaging quality of the lens.

[0066] In exemplary embodiments, the optical imaging system according to the present application can satisfy: (f / EPD+f / d0s) / 2<1.7, where f is an effective focal length of the optical imaging system, EPD is an entrance pupil diameter of the optical imaging system, and d0s is an inner diameter of a front end surface of a lens barrel close to an object side. More specifically, f, EPD and d0s can further satisfy: 1.30 < (f / EPD+f / d0s) / 2<1.52. Satisfying (f / EPD+f / d0s) / 2<1.7 is conducive to meeting the needs of customers for night shooting, on the one hand, the night shooting demand requires a large amount of light, and by controlling this condition, it is helpful to increase the amount of light to make the shooting clearer; on the other hand, controlling the entrance pupil position and the structure design of the front end of the lens barrel can avoid the risk of stray light of the lens barrel.

[0067] In exemplary embodiments, the optical imaging system according to the present application can satisfy: -5.0 < (CTx+CPx) x 100 / (Ry-Rz) < 0 or 0 < (CTx+CPx) x 100 / (Ry-Rz) < 30.0, x = 5, 6 or 7, y = 2x-1, z = 2i; wherein, when x is 5, y = 9, z = 10, CT5 represents the center thickness of the fifth lens along the optical axis, CP5 represents the maximum thickness of the fifth spacer element along the optical axis, R9 represents the radius of curvature of the object side surface of the fifth lens, and R10 represents the radius of curvature of the image side surface of the fifth lens; when x is 6, y = 11, z = 12, CT6 represents the center thickness of the sixth lens along the optical axis, CP6 represents the maximum thickness of the sixth spacer element along the optical axis, R11 represents the radius of curvature of the object side surface of the sixth lens, and R12 represents the radius of curvature of the image side surface of the sixth lens; when x is 7, y = 13, z = 14, CT7 represents the center thickness of the seventh lens along the optical axis, CP7 represents the maximum thickness of the seventh spacer element along the optical axis, R13 represents the radius of curvature of the object side surface of the seventh lens, and R14 represents the radius of curvature of the image side surface of the seventh lens. More specifically, the optical imaging system can further satisfy: -1.3 < (CTx+CPx) x 100 / (Ry-Rz) < -0.1 and 3.0 < (CTx+CPx) x 100 / (Ry-Rz) < 25.0, x = 5, 6 or 7, y = 2x-1, z = 2i. Controlling the condition formula is conducive to reasonably controlling the lens radius of curvature and the center thickness of the lens along the optical axis, which can ensure that the fifth lens to the seventh lens have good machining feasibility, and effectively ensure the accuracy of the lens-to-lens abutting position after assembly, and the performance meets the customer's requirements; on the other hand, controlling the thickness of the spacer element helps to ensure the stray light effect of the spacer element itself, thereby improving the lens imaging quality.

[0068] In exemplary embodiments, the optical imaging system according to the present application can satisfy: 0 < |(R15 / d7bm) / (f8 / f)| < 55.0, where R15 is the curvature radius of the object side surface of the eighth lens, d7bm is the inner diameter of the image side surface of the auxiliary spacer element, f is the effective focal length of the optical imaging system, and f8 is the effective focal length of the eighth lens. More specifically, R15, d7bm, f8 and f can further satisfy: 16.0 < |(R15 / d7bm) / (f8 / f)| < 51.0. The optical imaging system according to the present application is an eight-piece large image surface lens, and the eighth lens is the lens with the largest outer diameter in the optical imaging system, which has a larger risk of molding and stray light. Satisfying 0 < |(R15 / d7bm) / (f8 / f)| < 55.0 can effectively control the surface shape of the eighth lens, ensure the smoothness of the surface shape of the image side surface of the eighth lens, make the sol gel wavefront curve relatively smooth during injection molding, avoid convergence wrapping, reduce the risk of weld lines, and thus reduce the risk of stray light and appearance caused by weld lines. In addition, the thick spacer element and the auxiliary spacer element are used between the seventh lens and the eighth lens due to the large step difference, the auxiliary spacer element can optimize the performance by different thicknesses during actual assembly, and can prevent stray light reflected from the filter to the thick spacer element.

[0069] In exemplary embodiments, the optical imaging system according to the present application can satisfy: -10.0 < (D7bm / R16) x (f / f8) < 0, where R16 is the curvature radius of the image side surface of the eighth lens, D7bm is the outer diameter of the image side surface of the auxiliary spacer element, f is the effective focal length of the optical imaging system, and f8 is the effective focal length of the eighth lens. More specifically, R16, D7bm, f8 and f can further satisfy: -5.5 < (D7bm / R16) x (f / f8) < -4.0. The optical imaging system according to the present application is an eight-piece large image surface lens, and the eighth lens is the lens with the largest outer diameter in the optical imaging system, which has a larger risk of molding and stray light. Satisfying -10.0 < (D7bm / R16) x (f / f8) < 0 can effectively control the surface shape of the eighth lens, ensure the smoothness of the surface shape of the image side surface of the eighth lens, make the sol gel wavefront curve relatively smooth during injection molding, avoid convergence wrapping, reduce the risk of weld lines, and thus reduce the risk of stray light and appearance caused by weld lines. In addition, the thick spacer element and the auxiliary spacer element are used between the seventh lens and the eighth lens due to the large step difference, the auxiliary spacer element can optimize the performance by different thicknesses during actual assembly, and can prevent stray light reflected from the filter to the thick spacer element.

[0070] In exemplary embodiments, the effective focal length f of the optical imaging system can be, for example, in the range of 8.4mm to 8.9mm, the effective focal length f1 of the first lens can be, for example, in the range of 8.8mm to 9.3mm, the effective focal length f2 of the second lens can be, for example, in the range of -29.3mm to -25.6mm, the effective focal length f3 of the third lens can be, for example, in the range of 41.4mm to 80.2mm, the effective focal length f4 of the fourth lens can be, for example, in the range of -47.1mm to -37.4mm, the effective focal length f5 of the fifth lens can be, for example, in the range of 21.2mm to 49.1mm, the effective focal length f6 of the sixth lens can be, for example, in the range of -7.8mm to -7.3mm, the effective focal length f7 of the seventh lens can be, for example, in the range of 5.1mm to 5.3mm, and the effective focal length f8 of the eighth lens can be, for example, in the range of 8.4mm to 8.9mm. The optical imaging system according to the present application can have a smaller total optical length, for example, the total optical length TTL of the optical imaging system can satisfy 10.8mm < TTL < 11.3mm, in the case of having a large image.

[0071] In exemplary embodiments, the total optical length TTL of the optical imaging system and the effective focal length f of the optical imaging system satisfy: 1.20 < TTL / f < 1.30, which reasonably controls the ratio of TTL and f of the optical imaging system, and is beneficial to maintain the miniaturization feature of the optical imaging system.

[0072] In exemplary embodiments, the optical imaging system according to the present application can satisfy: Semi-FOV > 32°, wherein Semi-FOV is the maximum half field angle of the optical imaging system. More specifically, the maximum half field angle Semi-FOV of the optical imaging system can be, for example, in the range of 32.8° to 43.8°.

[0073] In exemplary embodiments, the optical imaging system according to the present application can satisfy: f / EPD < 1.8, wherein f is the effective focal length of the optical imaging system, and EPD is the entrance pupil diameter of the optical imaging system. Exemplarily, f / EPD can be, for example, in the range of 1.65 to 1.80.

[0074] In the embodiments of the present application, at least one of the mirror surfaces of each lens is an aspherical mirror surface, i.e., at least one of the object side surface of the first lens to the image side surface of the eighth lens is an aspherical mirror surface. The aspherical lens is characterized in that the curvature is continuously changed from the center of the lens to the periphery of the lens. Unlike the spherical lens having a constant curvature from the center of the lens to the periphery of the lens, the aspherical lens has a better curvature radius characteristic, and has the advantages of improving the distortion aberration and improving the astigmatism aberration. After the aspherical lens is used, the aberration occurring during imaging can be eliminated as much as possible, thereby improving the imaging quality. Alternatively, the object side surface and the image side surface of all the lenses from the first lens to the eighth lens are aspherical mirror surfaces.

[0075] In the exemplary embodiments, the optical imaging system described above can further include a filter for correcting color deviation and / or a protective glass for protecting the photosensitive element located on the imaging surface.

[0076] The optical imaging system according to the above embodiments of the present application can use multiple lenses, for example, eight lenses as described above. By reasonably allocating the optical power of each lens, the surface shape, and the arrangement of each spacer element, etc., the span of each gear position of the lens and the lens barrel is relatively uniform, and the light converging ability is enhanced, thereby improving the imaging quality of the ultra-thin and large imaging surface imaging lens.

[0077] However, those skilled in the art should understand that the number of lenses constituting the optical imaging system can be changed without departing from the technical solutions claimed by the present application, to obtain the various results and advantages described in the specification. For example, although eight lenses are described in the embodiments, the optical imaging system is not limited to including eight lenses. If necessary, the optical imaging system can also include other numbers of lenses.

[0078] The specific embodiments of the optical imaging system applicable to the above embodiments are further described below with reference to the accompanying drawings.

[0079] Example 1

[0080] The following refers to Figures 2A to 3D The optical imaging system 1001, the optical imaging system 1002, and the optical imaging system 1003 according to the embodiment 1 of the present application are described. Figures 2A to 2C The structural schematic diagrams of the optical imaging system 1001, the optical imaging system 1002, and the optical imaging system 1003 according to the embodiment 1 of the present application are respectively shown.

[0081] As Figures 2A to 2C shown, the optical imaging system 1001, the optical imaging system 1002, and the optical imaging system 1003 each include a lens barrel P0, a lens group E1-E8, and a plurality of spacer elements P1-P7b.

[0082] like Figures 2A to 2C As shown, optical imaging systems 1001, 1002, and 1003 employ the same lens group, which, 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 spacer element E6, a seventh spacer element E7, and an eighth spacer element E8. Specifically, 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 negative optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has positive optical power, with its object-side surface S5 being concave and its image-side surface S6 being convex. 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 negative optical power, with its object-side surface S11 being concave and its image-side surface S12 being convex. The seventh lens E7 has positive optical power, with its object-side surface S13 being convex and its image-side surface S14 being convex. 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 each surface S1 to S18 and is finally imaged on the imaging surface S19.

[0083] Table 1 shows the basic parameters of the lens groups of optical imaging systems 1001, 1002 and 1003 of Embodiment 1, wherein the units of radius of curvature, thickness / distance and effective focal length are millimeters (mm).

[0084]

[0085] Table 1

[0086] In this example, the effective focal length f of optical imaging systems 1001, 1002, and 1003 is 8.89 mm, the maximum semi-field of view (Semi-FOV) of optical imaging systems 1001, 1002, and 1003 is 32.9°, the ratio f / EPD of the effective focal length f of optical imaging systems 1001, 1002, and 1003 to the entrance pupil diameter (EPD) is 1.66, and the total optical length (TTL) of optical imaging systems 1001, 1002, and 1003 is 11.28 mm.

[0087] In Embodiment 1, 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:

[0088]

[0089] 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. Tables 2-1 and 2-2 give the higher-order coefficients A4, A6, A8, A16, A27, A18, A19 ... 10 A 12 A 14 A 16 A 18 A 20 A 22 A 24 A 26 A 28 and A 30 .

[0090] Face number A4 A6 A8 A10 A12 A14 A16 S1 -8.0660E-02 -2.3386E-02 -1.0124E-02 -4.5045E-03 -1.9813E-03 -8.1426E-04 -3.4005E-04 S2 4.3428E-03 -8.5248E-03 -9.5188E-03 -7.4325E-05 -1.8593E-03 2.8945E-04 -2.5172E-04 S3 -1.0606E-01 3.3878E-02 -9.5820E-05 3.5690E-03 -9.5732E-04 2.3773E-04 -2.5510E-04 S4 -8.4459E-02 3.1504E-02 7.0140E-03 4.2208E-03 1.0828E-03 3.3465E-04 1.3397E-05 S5 -1.6151E-01 -1.8280E-03 5.5376E-03 2.0033E-03 8.8385E-05 -2.7989E-04 -2.5186E-04 S6 -3.1664E-01 3.5092E-02 1.9347E-03 2.2056E-03 4.6056E-04 -1.4718E-04 9.3979E-05 S7 -5.4983E-01 -9.8818E-04 2.8834E-03 4.2580E-03 1.8768E-03 6.4032E-04 3.9786E-04 S8 -4.6981E-01 1.0355E-02 1.2378E-02 5.6201E-03 1.9190E-03 5.6396E-04 2.7308E-04 S9 -6.8101E-01 9.9757E-02 1.2251E-03 -3.5579E-03 4.9589E-03 -1.1718E-04 1.2595E-04 S10 -5.0527E-01 -2.4436E-02 1.2487E-02 -1.5938E-03 7.7129E-03 -2.2211E-03 1.4602E-03 S11 1.0446E+00 -3.2181E-02 6.2463E-02 -8.4800E-03 -4.7321E-03 -6.0612E-03 4.7604E-03 S12 -9.8235E-01 3.5214E-01 9.3252E-03 -2.5320E-03 -1.5998E-02 -7.1026E-03 3.8468E-03 S13 -3.1961E+00 1.3799E-01 4.3321E-02 5.5514E-02 -1.0806E-02 -1.1898E-02 -5.5501E-03 S14 -4.6498E-01 2.5170E-02 1.3029E-01 -3.2889E-02 -1.9160E-02 -3.7697E-04 6.5454E-03

[0091] Table 2-1

[0092]

[0093]

[0094] Table 2-2

[0095] like Figures 2A to 2C As shown, optical imaging systems 1001, 1002, and 1003 each include seven spacer elements P1 to P7 and one auxiliary spacer element P7b. The first spacer element P1 is positioned on the image-side of the first lens and is at least partially in contact with it; the second spacer element P2 is positioned on the image-side of the second lens and is at least partially in contact with it; the third spacer element P3 is positioned on the image-side of the third lens and is at least partially in contact with it; the fourth spacer element P4 is positioned on the image-side of the fourth lens and is at least partially in contact with it; the fifth spacer element P5 is positioned on the image-side of the fifth lens and is at least partially in contact with it; the sixth spacer element P6 is positioned on the image-side of the sixth lens and is at least partially in contact with it; the seventh spacer element P7 is positioned on the image-side of the seventh lens and is at least partially in contact with it; and the auxiliary spacer element P7b is positioned on the image-side of the seventh spacer element P7 and is at least partially in contact with it.

[0096] In the present embodiment, the first to sixth spacer elements P1-P6 and the auxiliary spacer element P7b of the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003 are spacers, and the seventh spacer element P7 is a spacer ring. The above spacer elements can prevent external stray light from entering, make the lens better abut against the lens barrel, and enhance the structural stability of the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003.

[0097] Table 3 shows the basic parameters of the spacer elements and the lens barrel of the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003 of Embodiment 1. The units of the parameters in Table 3 are millimeters (mm). For example, the distance from the front end surface of the lens barrel close to the object side to the rear end surface of the lens barrel close to the image side along the optical axis (i.e., the total length of the lens barrel in the direction of the optical axis) L of the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003 is 10.2003 mm, and the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003 differ in the structural dimensions of the spacer elements.

[0098]

[0099]

[0100] Table 3

[0101] Figure 3A The on-axis chromatic aberration curves of the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003 of Embodiment 1 are shown, which represent the deviation of light rays of different wavelengths from the converging focal point after passing through the lens. Figure 3B The astigmatism curves of the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003 of Embodiment 1 are shown, which represent the meridional image curvature and the sagittal image curvature. Figure 3C The distortion curves of the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003 of Embodiment 1 are shown, which represent the distortion size values corresponding to different image heights. Figure 3D The magnification chromatic aberration curves of the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003 of Embodiment 1 are shown, which represent the deviation of light rays on the imaging surface after passing through the lens at different image heights. According to Figures 3A to 3D It can be seen that the optical imaging system 1001, the optical imaging system 1002 and the optical imaging system 1003 given in Embodiment 1 can achieve good imaging quality.

[0102] Example 2

[0103] The following refers toFigures 4A to 5D Optical imaging systems 2001, 2002 and 2003 according to Embodiment 2 of the present application are described. In this and the following embodiments, for the sake of brevity, some descriptions similar to Embodiment 1 will be omitted. Figures 4A to 4C Structural schematic diagrams of optical imaging systems 2001, 2002 and 2003 according to Embodiment 2 of the present application are shown respectively.

[0104] As shown in FIG. 2A, optical imaging system 2001 includes a lens barrel P0, lens groups E1-E8 and a plurality of spacer elements P1-P7b. Figures 4A to 4C As shown in FIG. 2A, optical imaging system 2001 includes a lens barrel P0, lens groups E1-E8 and a plurality of spacer elements P1-P7b.

[0105] As shown in FIG. 2A, optical imaging system 2001 includes a lens barrel P0, lens groups E1-E8 and a plurality of spacer elements P1-P7b. Figures 4A to 4C As shown in FIG. 2A, optical imaging system 2001 includes a lens barrel P0, lens groups E1-E8 and a plurality of spacer elements P1-P7b. The lens groups used by optical imaging systems 2001, 2002 and 2003 are the same, and include in order from the object side to the image side: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth spacer element E6, a seventh spacer element E7 and an eighth spacer element E8. The first lens E1 has positive refractive power, with a convex object side surface S1 and a concave image side surface S2. The second lens E2 has negative refractive power, with a convex object side surface S3 and a concave image side surface S4. The third lens E3 has positive refractive power, with a concave object side surface S5 and a convex image side surface S6. The fourth lens E4 has negative refractive power, with a convex object side surface S7 and a concave image side surface S8. The fifth lens E5 has positive refractive power, with a convex object side surface S9 and a concave image side surface S10. The sixth lens E6 has negative refractive power, with a concave object side surface S11 and a convex image side surface S12. The seventh lens E7 has positive refractive power, with a convex object side surface S13 and a convex image side surface S14. The eighth lens E8 has negative refractive power, with a concave object side surface S15 and a concave image side surface S16. The filter E9 has an object side surface S17 and an image side surface S18. Light from an object passes through the surfaces S1-S18 in order and is ultimately imaged on an image plane S19.

[0106] In this example, the effective focal length f of optical imaging systems 2001, 2002 and 2003 is 8.74 mm, the maximum half field angle Semi-FOV of optical imaging systems 2001, 2002 and 2003 is 42.9°, the ratio f / EPD of the effective focal length f to the entrance pupil diameter EPD of optical imaging systems 2001, 2002 and 2003 is 1.79, and the total optical length TTL of optical imaging systems 2001, 2002 and 2003 is 10.87 mm.

[0107] Table 4 shows the basic parameters of the lens groups of optical imaging systems 2001, 2002 and 2003 of Embodiment 2, wherein the units of radius of curvature, thickness / distance and effective focal length are millimeters (mm). Tables 5-1 and 5-2 show the higher-order coefficients that can be used for each aspherical mirror in Embodiment 2, wherein each aspherical surface shape can be defined by formula (1) given in Embodiment 1 above.

[0108]

[0109] Table 4

[0110]

[0111]

[0112] Table 5-1

[0113] Face number A18 A20 A22 A24 A26 A28 A30 S1 -4.3960E-05 -1.7312E-05 -3.7951E-06 -2.4479E-06 2.1121E-07 -1.8001E-07 1.3737E-06 S2 1.0989E-04 -2.6375E-05 1.0780E-05 -3.8011E-06 -1.7511E-06 -3.9287E-06 -2.4325E-06 S3 8.9919E-05 -6.7644E-06 8.8120E-06 2.2752E-06 3.5744E-06 -5.1852E-07 9.2688E-07 S4 -5.3015E-06 7.2449E-06 -2.9290E-06 2.1954E-06 1.3370E-06 1.7200E-06 -1.9040E-06 S5 -3.7940E-05 -2.0168E-05 8.3600E-06 6.2451E-07 2.1018E-06 2.6522E-07 2.0013E-06 S6 -2.3909E-05 -1.5950E-05 -1.0161E-07 8.7321E-06 2.8937E-06 3.4993E-06 1.3821E-07 S7 5.8741E-06 -7.5841E-07 -1.7062E-05 1.0404E-05 3.3951E-07 4.2475E-06 1.7968E-06 S8 -2.0140E-05 7.6664E-05 -8.2156E-05 5.3471E-05 -1.3656E-05 1.2303E-05 -6.7196E-06 S9 -6.3584E-04 3.0732E-04 -2.6267E-04 1.0080E-04 -1.2574E-05 7.2527E-06 -3.0420E-06 S10 -8.0606E-04 6.7195E-04 -2.9701E-04 5.7320E-05 -3.5936E-05 5.4343E-06 -4.6279E-06 S11 -3.1848E-04 6.9510E-04 -4.2107E-04 -1.1178E-05 1.6489E-05 4.5597E-05 -1.6670E-05 S12 -6.1620E-06 1.0103E-03 -3.1225E-04 9.1954E-05 -7.8591E-05 4.1848E-05 -1.3975E-05 S13 -1.4332E-03 7.2581E-04 4.0147E-04 4.7163E-04 4.4534E-05 -2.0023E-05 -6.3797E-05 S14 1.2968E-03 -1.2277E-03 -6.7512E-04 1.9184E-04 2.7348E-04 2.1190E-06 -3.2922E-05

[0114] Table 5-2

[0115] like Figures 4A to 4C As shown, optical imaging systems 2001, 2002, and 2003 each include seven spacer elements P1 to P7 and one auxiliary spacer element P7b. The first spacer element P1 is positioned on the image-side of the first lens and is at least partially in contact with it; the second spacer element P2 is positioned on the image-side of the second lens and is at least partially in contact with it; the third spacer element P3 is positioned on the image-side of the third lens and is at least partially in contact with it; the fourth spacer element P4 is positioned on the image-side of the fourth lens and is at least partially in contact with it; the fifth spacer element P5 is positioned on the image-side of the fifth lens and is at least partially in contact with it; the sixth spacer element P6 is positioned on the image-side of the sixth lens and is at least partially in contact with it; the seventh spacer element P7 is positioned on the image-side of the seventh lens and is at least partially in contact with it; and the auxiliary spacer element P7b is positioned on the image-side of the seventh spacer element P7 and is at least partially in contact with it.

[0116] In this embodiment, the first spacer element P1 to the sixth spacer element P6 and the auxiliary spacer element P7b of the optical imaging system 2001 are spacers, and the seventh spacer element P7 is a spacer ring. The aforementioned spacers can block excess external light from entering, allowing the lens to better support the lens barrel, and enhancing the structural stability of the optical imaging systems 2001, 2002, and 2003.

[0117] Table 6 shows the basic parameters of the spacer elements and the lens barrel of the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 of Example 2. The units of the parameters in Table 6 are millimeters (mm). Exemplarily, the distance from the front end surface of the lens barrel near the object side to the rear end surface of the lens barrel near the image side along the optical axis (i.e., the total length of the lens barrel in the direction of the optical axis) L of the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 is 10.2003 mm, and the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 differ in the structural dimensions of the spacer elements.

[0118] Parameter / optical imaging system Optical imaging system 2001 Optical imaging system 2002 Optical imaging system 2003 d1s 4.5660 4.6119 4.5660 D1s 6.8086 6.0197 5.9190 d2s 4.1580 4.1580 4.1580 D2s 6.9280 6.1790 6.1190 D3s 7.0480 6.3391 6.3190 d4s 5.1280 5.1750 5.1280 D4s 7.1680 7.6966 6.5180 d5s 5.8000 5.8362 5.8000 D5s 8.5930 8.8930 6.7180 d6s 6.6780 6.7524 6.6780 D6s 9.0400 9.3407 9.0400 d7s 8.2694 8.4640 8.2640 D7s 9.1710 14.5027 9.1712 d0s 7.1220 8.2408 7.1220 d0m 16.5674 16.9121 16.5674 D0m 17.7600 18.0916 17.7600 d7bm 12.6960 12.5995 12.6960 D7bm 15.5920 15.9339 15.5920 EP01 2.2669 2.2069 2.2669 CP1 0.0180 0.0180 0.0180 EP12 0.6166 6.6766 0.6166 CP2 0.0180 0.0180 0.0180 EP23 0.3653 0.4153 0.3653 CP3 0.0180 0.0180 0.0180 EP34 0.6002 0.5702 0.6002 CP4 0.0180 0.0180 0.0180 EP45 0.3837 0.3837 0.3837 CP5 0.0180 0.0180 0.0180 EP56 0.5935 0.6035 0.5935 CP6 0.0180 0.0180 0.0180 CP7 2.0070 1.9078 2.0070 L 10.2003 10.2003 10.2003 ∑EP 3.1041 9.1941 3.1042

[0119] Table 6

[0120] Figure 5A The on-axis chromatic aberration curves of the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 of Example 2 are shown, which represent the deviation of light rays of different wavelengths from the converging focal point after passing through the lens. Figure 5B The astigmatism curves of the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 of Example 2 are shown, which represent the meridional image curvature and the sagittal image curvature. Figure 5C The distortion curves of the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 of Example 2 are shown, which represent the distortion size values corresponding to different image heights. Figure 5D The magnification chromatic aberration curves of the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 of Example 2 are shown, which represent the deviation of light rays on the imaging surface after passing through the lens at different image heights. According to Figures 5A to 5D It can be seen that the optical imaging system 2001, the optical imaging system 2002 and the optical imaging system 2003 given in Example 2 can achieve good imaging quality.

[0121] Example 3

[0122] The following refers to Figures 6A to 7D The optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 according to Example 3 of the present application are described. Figures 6A to 6C The structural schematic diagrams of the optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 according to Example 3 of the present application are shown respectively.

[0123] As Figures 6A to 6CAs shown, optical imaging systems 3001, 3002 and 3003 each include a lens barrel P0, lens groups E1 to E8 and multiple spacer elements P1 to P7b.

[0124] like Figures 6A to 6C As shown, optical imaging systems 3001, 3002, and 3003 employ the same lens group, which, 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 spacer element E6, a seventh spacer element E7, and an eighth spacer element E8. Specifically, 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 negative optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has positive optical power, with its object-side surface S5 being concave and its image-side surface S6 being convex. 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 negative optical power, with its object-side surface S11 being concave and its image-side surface S12 being convex. The seventh lens E7 has positive optical power, with its object-side surface S13 being convex and its image-side surface S14 being convex. 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 each surface S1 to S18 and is finally imaged on the imaging surface S19.

[0125] In this example, the effective focal length f of optical imaging systems 3001, 3002, and 3003 is 8.49 mm, the maximum semi-field of view (Semi-FOV) of optical imaging systems 3001, 3002, and 3003 is 43.7°, the ratio f / EPD of the effective focal length f of optical imaging systems 3001, 3002, and 3003 to the entrance pupil diameter (EPD) is 1.66, and the total optical length (TTL) of optical imaging systems 3001, 3002, and 3003 is 10.91 mm.

[0126] Table 7 shows the basic parameters of the lens groups of optical imaging systems 3001, 3002, and 3003 in Embodiment 3, wherein the units of radius of curvature, thickness / distance, and effective focal length are millimeters (mm). Tables 8-1 and 8-2 show the higher-order coefficients that can be used for each aspherical mirror in Embodiment 3, wherein each aspherical surface shape can be defined by formula (1) given in Embodiment 1 above.

[0127]

[0128]

[0129] Table 7

[0130] Face number A4 A6 A8 A10 A12 A14 A16 S1 -6.6101E-02 -1.7319E-02 -6.6442E-03 -2.3983E-03 -9.0535E-04 -3.0426E-04 -1.4598E-04 S2 -1.1900E-02 -6.2405E-04 -7.0802E-03 1.6422E-03 -1.4528E-03 3.4339E-04 -3.1972E-04 S3 -1.0224E-01 3.0549E-02 5.5536E-04 4.3996E-03 -6.0561E-04 2.7840E-04 -3.0332E-04 S4 -8.5348E-02 2.2124E-02 5.6488E-03 4.1510E-03 1.4132E-03 5.5017E-04 1.3441E-04 S5 -1.4260E-01 -5.1871E-03 5.1538E-03 2.8104E-03 1.2211E-03 2.8710E-04 2.0421E-05 S6 -3.1975E-01 2.8273E-02 3.4406E-03 1.9810E-03 9.7740E-04 5.0262E-04 3.1798E-04 S7 -5.1817E-01 -1.7641E-02 3.4427E-03 4.5776E-03 1.3644E-03 1.3225E-03 6.2388E-04 S8 -4.6193E-01 3.3048E-03 1.3049E-02 6.6391E-03 5.1849E-04 1.1227E-03 2.5394E-04 S9 -7.1786E-01 1.1434E-01 3.8620E-04 -3.7969E-03 3.6788E-03 4.7985E-04 2.3140E-06 S10 -4.5556E-01 -2.5186E-02 1.1006E-02 -1.8014E-03 7.5524E-03 -1.9484E-03 7.1669E-04 S11 9.8520E-01 -1.0172E-01 6.1459E-02 -1.1756E-02 -3.6960E-03 -7.6555E-03 5.5572E-03 S12 -7.2854E-01 3.2191E-01 2.3234E-02 -1.0686E-02 -1.2654E-02 -1.0903E-02 5.8538E-03 S13 -3.1474E+00 1.3053E-01 5.9483E-02 4.9798E-02 -8.1181E-03 -1.6448E-02 -5.7578E-03 S14 -3.0525E-01 5.0009E-03 1.4052E-01 -4.3386E-02 -1.2904E-02 -6.8447E-04 5.7173E-03

[0131] Table 8-1

[0132]

[0133]

[0134] Table 8-2

[0135] like Figures 6A to 6C As shown, optical imaging systems 3001, 3002, and 3003 each include seven spacer elements P1 to P7 and one auxiliary spacer element P7b. The first spacer element P1 is positioned on the image-side of the first lens and is at least partially in contact with it; the second spacer element P2 is positioned on the image-side of the second lens and is at least partially in contact with it; the third spacer element P3 is positioned on the image-side of the third lens and is at least partially in contact with it; the fourth spacer element P4 is positioned on the image-side of the fourth lens and is at least partially in contact with it; the fifth spacer element P5 is positioned on the image-side of the fifth lens and is at least partially in contact with it; the sixth spacer element P6 is positioned on the image-side of the sixth lens and is at least partially in contact with it; the seventh spacer element P7 is positioned on the image-side of the seventh lens and is at least partially in contact with it; and the auxiliary spacer element P7b is positioned on the image-side of the seventh spacer element P7 and is at least partially in contact with it.

[0136] In this embodiment, the first spacer elements P1 to the sixth spacer element P6 and the auxiliary spacer element P7b of the optical imaging systems 3001, 3002, and 3003 are spacers, and the seventh spacer element P7 is a spacer ring. These spacers can block excess external light from entering, allowing the lens to better contact the lens barrel and enhancing the structural stability of the optical imaging systems 3001, 3002, and 3003.

[0137] Table 9 shows the basic parameters of the spacer elements and the lens barrel of the optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 of Embodiment 3. The units of the parameters in Table 9 are millimeters (mm). Exemplarily, the distance from the front end surface of the lens barrel of the optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 near the object side to the rear end surface of the lens barrel near the image side along the optical axis (i.e., the total length of the lens barrel in the direction of the optical axis) L is 10.2003 mm, and the optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 differ in the structural dimensions of the spacer elements.

[0138]

[0139]

[0140] Table 9

[0141] Figure 7A The on-axis chromatic aberration curves of the optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 of Embodiment 3 are shown, which represent the deviation of light rays of different wavelengths from the converging focal point after passing through the lens. Figure 7B The astigmatism curves of the optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 of Embodiment 3 are shown, which represent the meridional image curvature and the sagittal image curvature. Figure 7C The distortion curves of the optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 of Embodiment 3 are shown, which represent the distortion size values corresponding to different image heights. Figure 7D The magnification chromatic aberration curves of the optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 of Embodiment 3 are shown, which represent the deviation of light rays on the imaging surface after passing through the lens. According to Figures 7A to 7D It can be seen that the optical imaging system 3001, the optical imaging system 3002 and the optical imaging system 3003 given in Embodiment 3 can achieve good imaging quality.

[0142] In summary, the optical imaging systems 1001, 1002, 1003, 2001, 2002, 2003, 3001, 3002 and 3003 of Embodiment 1 to Embodiment 3 satisfy the relationships shown in Table 10.

[0143]

[0144]

[0145] Table 10

[0146] The application also provides an imaging device, the electronic photosensitive element of which can be a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). The imaging device can be a stand-alone imaging apparatus such as a digital camera, or an imaging module integrated on a mobile electronic device such as a mobile phone. The imaging device is equipped with the optical imaging system described above.

[0147] The above description is merely preferred embodiments of the present application and a description of the principles of the technology used. It should be understood by those skilled in the art that the scope of the application involved in the present application is not limited to the technical solutions formed by the specific combinations of the technical features described above, and should also cover other technical solutions formed by any combinations of the technical features described above or their equivalent features without departing from the inventive concept. For example, the technical solutions formed by the mutual replacement of the above-described features and the technical features disclosed in the present application (but not limited to) having similar functions.

Claims

1. An optical imaging system characterized by, The optical imaging system comprises: a lens group comprising, in order from an object side to an image side along an optical axis, 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 the first lens, the third lens, the fifth lens, and the seventh lens have positive refractive powers, and the second lens, the fourth lens, the sixth lens, and the eighth lens have negative refractive powers; a plurality of spacer elements, comprising a seventh spacer element disposed on an image side of the seventh lens and at least partially in contact with the seventh lens, wherein a maximum thickness of the seventh spacer element along the optical axis is greater than a maximum thickness of other spacer elements in the plurality of spacer elements along the optical axis; and a lens barrel for accommodating the lens group and the plurality of spacer elements, a side wall of the seventh spacer element being at least partially in contact with the lens barrel. The number of lenses having refractive power in the optical imaging system is eight. A distance L along the optical axis from a front end surface of the lens barrel near the object side to a rear end surface of the lens barrel near the image side, an outer diameter D0m of the rear end surface of the lens barrel near the image side, an inner diameter d0m of the rear end surface of the lens barrel near the image side, and a distance TD on the optical axis from an object side surface of the first lens to an image side surface of the eighth lens satisfy: 1.12≤[L / (D0m / 2)+TD / (d0m / 2)] / 2≤1.

16.

2. The optical imaging system of claim 1, wherein, The lens barrel has a plurality of outer diameters having different size values in a direction perpendicular to the optical axis, and an outer diameter of the front end surface of the lens barrel near the object side is smaller than an outer diameter of the rear end surface of the lens barrel near the image side.

3. The optical imaging system of claim 1, wherein, The plurality of spacer elements further comprises a sixth spacer element disposed on an image side of the sixth lens and at least partially in contact with the sixth lens; wherein An outer diameter D7s of an object side surface of the seventh spacer element, an outer diameter D6s of an object side surface of the sixth spacer element, a center thickness CT7 of the seventh lens on the optical axis, and an air separation T78 of the seventh lens and the eighth lens on the optical axis satisfy: 5.45≤(D7s+D6s) / (CT7+T78)≤7.

14.

4. The optical imaging system of claim 1, wherein, The plurality of spacer elements further comprises a sixth spacer element disposed on an image side of the sixth lens and at least partially in contact with the sixth lens; wherein An inner diameter d6s of an object side surface of the sixth spacer element, a maximum thickness CP6 of the sixth spacer element along the optical axis, an inner diameter d7s of an object side surface of the seventh spacer element, a maximum thickness CP7 of the seventh spacer element along the optical axis, a center thickness CT7 of the seventh lens on the optical axis, and a center thickness CT8 of the eighth lens on the optical axis satisfy: 7.28≤[(d6s+d7s) / (CP6+CP7)] / (CT7 / CT8)≤8.

89.

5. The optical imaging system of claim 1, wherein, The plurality of spacer elements further comprises a second spacer element disposed on an image side of the second lens and at least partially in contact with the second lens, wherein An outer diameter D2s of the object side surface of the second spacer element, an inner diameter d2s of the object side surface of the second spacer element, a maximum thickness CP2 of the second spacer element in the direction of the optical axis, and a central thickness CT2 of the second lens on the optical axis satisfy: 5.38 ≤ (D2s - d2s) / (CT2 - CP2) < 8.

9.

6. The optical imaging system of claim 1, wherein, The plurality of spacer elements further include a first spacer element disposed on an image side surface of the first lens and at least partially in contact with the first lens, wherein An outer diameter D1s of the object side surface of the first spacer element, an inner diameter d1s of the object side surface of the first spacer element, a maximum thickness CP1 of the first spacer element in the direction of the optical axis, and a central thickness CT1 of the first lens on the optical axis satisfy: 0.79 ≤ (D1s - d1s) / (CT1 - CP1) < 1.

95.

7. The optical imaging system according to any one of claims 1 to 6, wherein The object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface.

8. The optical imaging system of claim 1, wherein, The plurality of spacer elements further include a first spacer element disposed on an image side surface of the first lens and at least partially in contact with the first lens, a second spacer element disposed on an image side surface of the second lens and at least partially in contact with the second lens, a third spacer element disposed on an image side surface of the third lens and at least partially in contact with the third lens, a fourth spacer element disposed on an image side surface of the fourth lens and at least partially in contact with the fourth lens, a fifth spacer element disposed on an image side surface of the fifth lens and at least partially in contact with the fifth lens, and a sixth spacer element disposed on an image side surface of the sixth lens and at least partially in contact with the sixth lens, and the optical imaging system satisfies: -40.0 < (fi + fj) / (CPi + EPij) ≤ 137.81, wherein i = 1, 2, 3, 4, or 5, and j = i + 1; wherein, when i = 1, j = 2, fi represents the effective focal length of the first lens, f2 represents the effective focal length of the second lens, CP1 represents the maximum thickness of the first spacer element in the direction of the optical axis, and EP12 represents the air interval between the first spacer element and the second spacer element in the direction of the optical axis; when i = 2, j = 3, f2 represents the effective focal length of the second lens, f3 represents the effective focal length of the third lens, CP2 represents the maximum thickness of the second spacer element in the direction of the optical axis, and EP23 represents the air interval between the second spacer element and the third spacer element in the direction of the optical axis; when i = 3, j = 4, f3 represents the effective focal length of the third lens, f4 represents the effective focal length of the fourth lens, CP3 represents the maximum thickness of the third spacer element in the direction of the optical axis, and EP34 represents the air interval between the third spacer element and the fourth spacer element in the direction of the optical axis; i takes 4, j=5, f4 represents the effective focal length of the fourth lens, f5 represents the effective focal length of the fifth lens, CP4 represents the maximum thickness of the fourth spacer element along the optical axis, EP45 represents the air gap between the fourth spacer element and the fifth spacer element along the optical axis; i takes 5, j=6, f5 represents the effective focal length of the fifth lens, f6 represents the effective focal length of the sixth lens, CP5 represents the maximum thickness of the fifth spacer element along the optical axis, EP56 represents the air gap between the fifth spacer element and the sixth spacer element along the optical axis.

9. The optical imaging system of claim 1, wherein, The plurality of spacer elements further comprises a second spacer element disposed on the image side of the second lens and at least partially in contact with the second lens, and a third spacer element disposed on the image side of the third lens and at least partially in contact with the third lens; wherein, The outer diameter D2s of the object side of the second spacer element, the outer diameter D3s of the object side of the third spacer element, the curvature radius R3 of the object side of the second lens, the curvature radius R4 of the image side of the second lens, the curvature radius R5 of the object side of the third lens and the curvature radius R6 of the image side of the third lens satisfy: 3.3<(D2s / (R3-R4)+D3s / (R5-R6)≤4.

84.

10. The optical imaging system of claim 1, wherein, The plurality of spacer elements further comprises a first spacer element disposed on the image side of the first lens and at least partially in contact with the first lens, a second spacer element disposed on the image side of the second lens and at least partially in contact with the second lens, a third spacer element disposed on the image side of the third lens and at least partially in contact with the third lens, a fourth spacer element disposed on the image side of the fourth lens and at least partially in contact with the fourth lens, a fifth spacer element disposed on the image side of the fifth lens and at least partially in contact with the fifth lens, and a sixth spacer element disposed on the image side of the sixth lens and at least partially in contact with the sixth lens, wherein, The distance EP01 from the front end surface of the lens barrel close to the object side to the object side surface of the first spacer element on the optical axis, the sum ΣEP of the air gaps between any two adjacent spacer elements in the first spacer element and the seventh spacer element along the optical axis, the air gap T12 between the first lens and the second lens on the optical axis, and the total sum ∑AT of the air gaps between any two adjacent lenses from the first lens to the eighth lens on the optical axis satisfy: 0.25≤EP01 / ΣEP+T12 / ΣAT≤0.

74.

11. The optical imaging system according to any one of claims 1 to 6, 8 to 10, characterized in that, The object side surface of the fourth lens is convex, and the image side surface is concave; the object side surface of the fifth lens is convex, and the image side surface is concave.

12. The optical imaging system according to any one of claims 1 to 6, 8 to 10, characterized in that, The plurality of spacer elements further comprises a fourth spacer element disposed on the image side of the fourth lens and at least partially in contact with the fourth lens, wherein, The object side surface of the fourth lens is convex, and the image side surface is concave; the object side surface of the fifth lens is convex, and the image side surface is concave. An outer diameter D4s of an object side surface of the fourth spacer element, an inner diameter d4s of the object side surface of the fourth spacer element, a radius of curvature R7 of an object side surface of the fourth lens, a radius of curvature R8 of an image side surface of the fourth lens, and an effective focal length f4 of the fourth lens and an effective focal length f5 of the fifth lens satisfy: -4.42mm≤(f4+f5) / (R7 / D4s+R8 / d4s)≤-1.84mm or 1.01mm≤(f4+f5) / (R7 / D4s+R8 / d4s)≤1.10mm.

13. The optical imaging system according to any one of claims 1 to 6, 8 to 10, characterized in that, The plurality of spacer elements further include a fifth spacer element disposed on an image side surface of the fifth lens and at least partially in contact with the fifth lens; wherein, An outer diameter D5s of an object side surface of the fifth spacer element, an inner diameter d5s of the object side surface of the fifth spacer element, a radius of curvature R9 of an object side surface of the fifth lens, a radius of curvature R10 of an image side surface of the fifth lens, the effective focal length f4 of the fourth lens and the effective focal length f5 of the fifth lens satisfy: 1.48≤[(D5s-d5s) / (R9-R10)]×100 / (f5 / f4)≤11.

50.

14. The optical imaging system of any of claims 1 to 6, 8 to 10, wherein, An object side surface of the sixth lens is a concave surface, and an image side surface of the sixth lens is a convex surface.

15. The optical imaging system of any of claims 1 to 6, 8 to 10, wherein, The plurality of spacer elements further include a sixth spacer element disposed on an image side surface of the sixth lens and at least partially in contact with the sixth lens; wherein, An outer diameter D6s of an object side surface of the sixth spacer element, an inner diameter d6s of the object side surface of the sixth spacer element, a radius of curvature R11 of an object side surface of the sixth lens, a radius of curvature R12 of an image side surface of the sixth lens, and an effective focal length f6 of the sixth lens satisfy: 2.2mm<(R12-R11)×(D6s-d6s) / f6≤7.41mm.

16. The optical imaging system of any of claims 1 to 6, 8 to 10, wherein, An effective focal length f of the optical imaging system, an entrance pupil diameter EPD of the optical imaging system, and an inner diameter d0s of a front end surface of the lens barrel close to the object side surface satisfy: 1.40≤(f / EPD+f / d0s) / 2<1.

52.

17. The optical imaging system of any of claims 1 to 6, 8 to 10, wherein, An object side surface of the seventh lens is a convex surface, and an image side surface of the seventh lens is a convex surface; and an image side surface of the eighth lens is a concave surface.

18. The optical imaging system of any of claims 1 to 6, 8 to 10, wherein, The plurality of spacer elements further include a fifth spacer element disposed on an image side surface of the fifth lens and at least partially in contact with the fifth lens and a sixth spacer element disposed on an image side surface of the sixth lens and at least partially in contact with the sixth lens; wherein, The optical imaging system satisfies: -1.3<(CTx+CPx)×100 / (Ry-Rz)<-0.1 or 3.0<(CTx+CPx)×100 / (Ry-Rz)≤24.12, x=5, 6 or 7, y=2x-1, z=2x; When x is 5, y=9, z=10, CT5 represents a central thickness of the fifth lens along the optical axis, CP5 represents a maximum thickness of the fifth spacer element along the optical axis, R9 represents a radius of curvature of an object side surface of the fifth lens, and R10 represents a radius of curvature of an image side surface of the fifth lens; and When x is 5, y=9, z=10, CT5 represents a central thickness of the fifth lens along the optical axis, CP5 represents a maximum thickness of the fifth spacer element along the optical axis, R9 represents a radius of curvature of an object side surface of the fifth lens, and R10 represents a radius of curvature of an image side surface of the fifth lens; and x is 6, y=11, z=12, CT6 represents a central thickness of the sixth lens on the optical axis, CP6 represents a maximum thickness of the sixth spacer element along the direction of the optical axis, R11 represents a curvature radius of an object side surface of the sixth lens, and R12 represents a curvature radius of an image side surface of the sixth lens; x is 7, y=13, z=14, CT7 represents a central thickness of the seventh lens on the optical axis, CP7 represents a maximum thickness of the seventh spacer element along the direction of the optical axis, R13 represents a curvature radius of an object side surface of the seventh lens, and R14 represents a curvature radius of an image side surface of the seventh lens.

19. The optical imaging system of any of claims 1 to 6, 8 to 10, wherein, The optical imaging system further comprises an auxiliary spacer element disposed on the image side of the seventh spacer element and at least partially in contact with the seventh spacer element, wherein, a curvature radius R15 of the object side surface of the eighth lens, an inner diameter d7bm of the image side surface of the auxiliary spacer element, an effective focal length f of the optical imaging system, and an effective focal length f8 of the eighth lens satisfy: 16.74≤|(R15 / d7bm) / (f8 / f)|≤50.

46.

20. The optical imaging system of any of claims 1 to 6, 8 to 10, wherein, The optical imaging system further comprises an auxiliary spacer element disposed on the image side of the seventh spacer element and at least partially in contact with the seventh spacer element, wherein, a curvature radius R16 of the image side surface of the eighth lens, an outer diameter D7bm of the image side surface of the auxiliary spacer element, an effective focal length f of the optical imaging system, and an effective focal length f8 of the eighth lens satisfy: -5.00≤(D7bm / R16)×(f / f8)≤-4.

73.

21. The optical imaging system of any of claims 1 to 6, 8 to 10, wherein, A distance along the optical axis from a center of an effective diameter of the image side surface of the second lens to a rear end surface of the lens barrel close to the image side is greater than a distance along the optical axis from an edge of the effective diameter of the image side surface of the second lens to the rear end surface of the lens barrel close to the image side.

Images