Optical imaging lens

Abstract

The application discloses an optical imaging lens, which comprises a lens barrel and a lens set. The lens set comprises eight lenses and sequentially comprises 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 from the object side to the image side along the optical axis. The seventh lens has positive refractive power. The eighth lens has negative refractive power. At least one spacing element is arranged between the first lens and the fourth lens. At least two spacing elements are arranged between the sixth lens and the eighth lens. The at least two spacing elements comprise a sixth spacing element located on the image side of the sixth lens and at least partially in contact with the sixth lens and a seventh spacing element located on the image side of the seventh lens and at least partially in contact with the seventh lens. The center thickness CT7 of the seventh lens on the optical axis, the center thickness CT8 of the eighth lens on the optical axis, the spacing EP67 of the sixth spacing element and the seventh spacing element on the optical axis and the maximum thickness CP7 of the seventh spacing element satisfy 0 < (CT7 + CT8) / (EP67 + CP7) < 3.5.

Description

Technical Field

[0001] This application relates to the field of optical devices, specifically to an eight-element optical imaging lens. Background Technology

[0002] In recent years, with the rapid development of portable electronic products such as smartphones, the differences in shooting requirements for optical imaging lenses in smartphones have become increasingly apparent. For example, through optical design of optical imaging lenses, it is possible to achieve imaging effects similar to widescreen cinema imaging in smartphones.

[0003] To achieve higher imaging requirements, optical imaging lenses with a higher element count are needed to fulfill their functions. However, for optical imaging lenses with a higher element count, the design and assembly become more complex, and problems such as poor assembly stability and stray light are more likely to occur. For example, because lenses relatively close to the image side in an optical imaging lens are more sensitive, they are prone to light leakage, stray light, or poor assembly stability. At the same time, if the thickness and optical power of the spacer elements and lenses at this location are not designed properly, light leakage, stray light, or poor assembly stability will also occur, thus affecting the image quality of the optical imaging lens. Summary of the Invention

[0004] This application provides an optical imaging lens that can at least solve or partially solve at least one problem or other problems existing in the prior art.

[0005] One aspect of this application provides an optical imaging lens comprising a lens barrel and a lens group, the lens group comprising eight lenses, the eight lenses being sequentially arranged along the optical axis from the object side to the image side as a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens; the seventh lens having positive optical power; the eighth lens having negative optical power; at least one spacer element disposed between the first lens and the fourth lens; at least two spacer elements disposed between the sixth lens and the eighth lens, the at least two spacer elements including a sixth spacer element located on the image side side of the sixth lens and at least partially in contact with the sixth lens, and a seventh spacer element located on the image side side of the seventh lens and at least partially in contact with the seventh lens, wherein the center thickness CT7 of the seventh lens on the optical axis, the center thickness CT8 of the eighth lens on the optical axis, the spacing EP67 of the sixth and seventh spacer elements on the optical axis, and the maximum thickness CP7 of the seventh spacer element satisfy 0 < (CT7 + CT8) / (EP67 + CP7) < 3.5.

[0006] According to an exemplary embodiment of this application, at least one of the first to eighth lenses is a freeform lens.

[0007] According to an exemplary embodiment of this application, the lens barrel is a split lens barrel, which includes a front lens barrel and a rear lens barrel. Both the front lens barrel and the rear lens barrel have a front end face that is closest to the object side and perpendicular to the optical axis, and a rear end face that is closest to the image side and perpendicular to the optical axis.

[0008] According to an exemplary embodiment of this application, at least one of the first to eighth lenses is placed inside the front lens barrel, and the length La of the front lens barrel on the optical axis and the length Lb of the rear lens barrel on the optical axis satisfy 0.1. <La / Lb<0.9。

[0009] According to an exemplary embodiment of this application, the outer diameter D0m of the image side of the lens barrel, the inner diameter d0m of the image side of the lens barrel, and the length L of the lens barrel on the optical axis satisfy 0.8 < (D0m + d0m) / L < 3.0.

[0010] According to an exemplary embodiment of this application, the inner diameter d0am of the rear end face of the front lens barrel, the inner diameter d0bs of the front end face of the rear lens barrel, and the thickness T14 of the first to fourth lenses on the optical axis satisfy -2.0<(d0am-d0bs) / T14<2.0.

[0011] According to an exemplary embodiment of this application, the outer diameter D0am of the rear end face of the front lens barrel, the outer diameter D0bs of the front end face of the rear lens barrel, the effective focal length f1 of the first lens, the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, and the outer diameter D0s of the object side face of the lens barrel satisfy 1.0 < (D0am + D0bs) / (f2 + f3) - D0s / f1 < 5.0.

[0012] According to an exemplary embodiment of this application, the first lens has negative optical power, the second lens has positive optical power, and both the first lens and the second lens are freeform surface lenses.

[0013] According to an exemplary embodiment of this application, the third and fourth lenses have positive optical power, and the fifth and sixth lenses have negative optical power.

[0014] According to an exemplary embodiment of this application, the optical imaging lens further includes a fifth spacer element located on the image side of the fifth lens, and a sixth spacer element is the spacer element with the largest thickness among the spacer elements between the sixth lens and the eighth lens. The maximum thickness CP5 of the fifth spacer element, the maximum thickness CP6 of the sixth spacer element, the spacing EP56 between the fifth and sixth spacer elements on the optical axis, the center thickness CT5 of the fifth lens on the optical axis, the center thickness CT6 of the sixth lens on the optical axis, and the air spacing T56 between the fifth and sixth lenses on the optical axis satisfy 3.0 < (CP5 + CP6) / EP56 + (CT5 + CT6) / T56 < 10.0.

[0015] According to an exemplary embodiment of this application, the inner diameter d5m of the image-side surface of the fifth spacer element, the inner diameter d6s of the object-side surface of the sixth spacer element, the radius of curvature R10 of the image-side surface of the fifth lens, and the radius of curvature R11 of the object-side surface of the sixth lens satisfy -1.0. <d5m / R10+d6s / R11<0。

[0016] According to an exemplary embodiment of this application, the radius of curvature R12 of the image side of the sixth lens, the effective focal length f6 of the sixth lens, the outer diameter D6m of the image side of the sixth spacer element, the inner diameter d6m of the image side of the sixth spacer element, the outer diameter D5m of the image side of the fifth spacer element, and the inner diameter d5m of the image side of the fifth spacer element satisfy -20.0<(R12×f6) / [(D6m-d6m)×(D5m-d5m)]<-3.0.

[0017] According to an exemplary embodiment of this application, the optical imaging lens further includes a fourth spacer element located on the image side of the fourth lens, wherein the outer diameter D4m of the image side of the fourth spacer element, the outer diameter D5m of the image side of the fifth spacer element, and the combined focal length f345 of the third lens, the fourth lens, and the fifth lens satisfy 1.0 < (D4m + D5m) / f345 < 5.0.

[0018] According to an exemplary embodiment of this application, the optical imaging lens further includes a sixth auxiliary spacer element, which is located on the image side of the sixth spacer element and at least partially in contact with the sixth spacer element. The outer diameter D6bm of the image side of the sixth auxiliary spacer element, the inner diameter d6bm of the image side of the sixth auxiliary spacer element, the air gap T67 between the sixth lens and the seventh lens on the optical axis, and the center thickness CT7 of the seventh lens on the optical axis satisfy 3.0 < (D6bm + d6bm) / (T67 + CT7) < 6.0.

[0019] According to an exemplary embodiment of this application, the refractive index N7 of the seventh lens, the refractive index N8 of the eighth lens, the combined focal length f78 of the seventh and eighth lenses, the maximum thickness CP6b of the sixth auxiliary spacer element, and the spacing EP67 of the sixth and seventh spacers on the optical axis satisfy 5.0 < (N7 + N8) / (CP6b + EP67) × f78 < 20.0.

[0020] According to an exemplary embodiment of this application, the dispersion coefficient V7 of the seventh lens, the dispersion coefficient V8 of the eighth lens, the outer diameter D7m of the image side of the seventh spacer element, the inner diameter d7m of the image side of the seventh spacer element, and the air gap T78 between the seventh lens and the eighth lens on the optical axis satisfy 0 < (V7 - V8) / (D7m - d7m) × T78 < 2.0.

[0021] This application optimizes the optical parameters of the seventh lens, the eighth lens, the sixth spacer element, and the seventh spacer element. Without affecting the sensitivity of the optical imaging lens, it can limit the thickness of the seventh and eighth lenses to facilitate lens forming while ensuring strength. At the same time, it can also limit the thickness of the seventh spacer element and the spacing between the sixth and seventh spacer elements to improve assembly stability and avoid light leakage and stray light problems caused by unreasonable matching of the thickness and optical power of the seventh and eighth lenses, thereby improving the imaging quality of the optical imaging lens. Attached Figure Description

[0022] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0023] Figure 1 A schematic diagram of the structure of an optical imaging lens according to this application is shown;

[0024] Figure 2 A schematic diagram of the optical imaging lens in the Y-axis direction according to Embodiment 1 of the first embodiment of this application is shown;

[0025] Figure 3 A schematic diagram of the structure of an optical imaging lens in the X-axis direction according to Embodiment 1 of the first embodiment of this application is shown;

[0026] Figure 4 A schematic diagram of the optical imaging lens in the Y-axis direction according to Embodiment 2 of the first embodiment of this application is shown;

[0027] Figure 5 A schematic diagram of the structure of an optical imaging lens in the X-axis direction according to Embodiment 2 of the first embodiment of this application is shown;

[0028] Figure 6 A schematic diagram of the optical imaging lens in the Y-axis direction according to Embodiment 3 of the first embodiment of this application is shown;

[0029] Figure 7 A schematic diagram of the structure of the optical imaging lens in the X-axis direction according to Embodiment 3 of the first embodiment of this application is shown;

[0030] Figures 8A to 8C The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the optical imaging lens according to the first embodiment of this application are shown respectively.

[0031] Figure 9 A schematic diagram of the optical imaging lens in the Y-axis direction according to Embodiment 1 of the second embodiment of this application is shown;

[0032] Figure 10 A schematic diagram of the structure of the optical imaging lens in the X-axis direction according to Embodiment 1 of the second embodiment of this application is shown;

[0033] Figure 11 A schematic diagram of the optical imaging lens in the Y-axis direction according to Embodiment 2 of the second embodiment of this application is shown;

[0034] Figure 12 A schematic diagram of the structure of the optical imaging lens in the X-axis direction according to Embodiment 2 of the second embodiment of this application is shown;

[0035] Figure 13 A schematic diagram of the optical imaging lens in the Y-axis direction according to Embodiment 3 of the second embodiment of this application is shown;

[0036] Figure 14 A schematic diagram of the structure of the optical imaging lens in the X-axis direction according to Embodiment 3 of the second embodiment of this application is shown;

[0037] Figures 15A to 15C The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the optical imaging lens according to the second embodiment of this application are shown respectively.

[0038] Figure 16 A schematic diagram of the optical imaging lens in the Y-axis direction according to Embodiment 1 of the third embodiment of this application is shown;

[0039] Figure 17 A schematic diagram of the structure of an optical imaging lens in the X-axis direction according to Embodiment 1 of the third embodiment of this application is shown;

[0040] Figure 18 A schematic diagram of the optical imaging lens in the Y-axis direction according to Embodiment 2 of the third embodiment of this application is shown;

[0041] Figure 19 A schematic diagram of the structure of the optical imaging lens in the X-axis direction according to Embodiment 2 of the third embodiment of this application is shown;

[0042] Figure 20 A schematic diagram of the optical imaging lens in the Y-axis direction according to Embodiment 3 of the third embodiment of this application is shown;

[0043] Figure 21 A schematic diagram of the optical imaging lens in the X-axis direction according to Embodiment 3 of the third embodiment of this application is shown; and

[0044] Figures 22A to 22C The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the optical imaging lens according to the third embodiment of this application are shown respectively. Detailed Implementation

[0045] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements.

[0046] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0047] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not drawn strictly to scale.

[0048] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0049] In this paper, we define the direction parallel to the optical axis as the Z-axis, the direction perpendicular to the Z-axis and lying in the meridional plane as the Y-axis, and the direction perpendicular to the Z-axis and lying in the sagittal plane as the X-axis. Unless otherwise specified, all parameter symbols (e.g., optical power, etc.) in this paper, except for those relating to the field of view, represent characteristic parameter values ​​along the Y-axis direction of the optical imaging lens. For example, unless otherwise specified, Semi-FOVx represents half of the maximum field of view of the optical imaging lens along the X-axis, Semi-FOVy represents half of the maximum field of view of the optical imaging lens along the Y-axis, and f represents the total effective focal length of the optical imaging lens along the Y-axis, etc.

[0050] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising" as used in this specification indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0051] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formalized sense, unless expressly so specified herein.

[0052] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0053] The features, principles and other aspects of this application are described in detail below.

[0054] An optical imaging lens according to an exemplary embodiment of this application may include a lens barrel and a lens group, wherein the lens group may include eight lenses with optical power, namely 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. These eight lenses are arranged sequentially along the optical axis from the object side to the image side. Among the first to eighth lenses, there may be an air gap between any two adjacent lenses.

[0055] In an exemplary embodiment, the first lens may have negative optical power, and the second lens may have positive optical power. By controlling the optical power distribution between the first and second lenses, it is possible to effectively ensure that the principal ray of the optical imaging lens has a small incident angle, increase the relative illumination, and thus improve the imaging quality of the optical imaging lens.

[0056] In an exemplary embodiment, the third lens may have positive optical power, the fourth lens may have positive optical power, the fifth lens may have negative optical power, and the sixth lens may have negative optical power. By controlling the optical power of the third to sixth lenses, the refractive power of the lenses can be effectively increased, thereby improving the imaging quality of the optical imaging lens while achieving the characteristics of a large image plane, and enabling the optical imaging lens to be ultra-thin.

[0057] In an exemplary embodiment, the seventh lens may have a positive optical power, and the eighth lens may have a negative optical power. By controlling the optical power distribution of the seventh lens and the eighth lens, the focal length ratio of the optical imaging lens in the X-axis direction and the Y-axis direction can be ensured to achieve a wide-format imaging effect without affecting the sensitivity of the optical imaging lens.

[0058] In an exemplary embodiment, at least one of the first lens to the eighth lens is a free-form lens. By using the design of free-form lenses in the optical imaging lens, the optical imaging lens can have different focal length ratios in the X / Y-axis directions, and the ratio is large enough, that is, the optical imaging lens has different magnification ratios in the X-axis direction and the Y-axis direction, which is beneficial to achieving a wide-format imaging effect.

[0059] In an exemplary embodiment, any one of the first lens to the eighth lens is a free-form lens or an aspherical lens. For example, the first lens, the second lens, the seventh lens, and the eighth lens are all free-form lenses. By controlling that the first lens, the second lens, the seventh lens, and the eighth lens are all free-form lenses, it is beneficial to make the optical imaging lens have different focal length ratios in the X / Y-axis directions, and then achieve a wide-format imaging effect.

[0060] In an exemplary embodiment, the lens barrel is a split lens barrel, which includes a front lens barrel and a rear lens barrel. Both the front lens barrel and the rear lens barrel have a front end face closest to the object side and perpendicular to the optical axis, and a rear end face closest to the image side and perpendicular to the optical axis. The split lens barrel is beneficial to the molding and assembly in place of single parts. By using the split lens barrel, the lens group can be further assembled in the lens barrel in the form of a multi-group combination technology, which can avoid the risks caused by using a single lens barrel and improve the yield of the optical imaging lens. The multi-group combination means that the eight lenses in the lens group are combined in different numbers, and the eight lenses can be combined, for example, in the form of 1+7, 2+6, or 3+5.

[0061] In an exemplary embodiment, at least one of the first lens to the eighth lens is placed in the front lens barrel. For example, the first lens can be placed in the front lens barrel. The length La of the front lens barrel on the optical axis and the length Lb of the rear lens barrel on the optical axis satisfy 0.1 < La / Lb < 0.9. In an example, 0.2 < La / Lb < 0.7. By controlling that the length of the rear lens barrel on the optical axis is greater than the length of the front lens barrel on the optical axis, it can be ensured that the center position of the overall combination is located on the rear lens barrel, which is beneficial to the assembly of the lens group.

[0062] In an exemplary embodiment, the lens barrel has an object-side side and an image-side side. The outer diameter D0m of the image-side side (i.e., the rear end face of the rear lens barrel), the inner diameter d0m of the image-side side (i.e., the rear end face of the rear lens barrel), and the length L of the lens barrel on the optical axis satisfy 0.8 < (D0m + d0m) / L < 3.0. In the example, 1.7 < (D0m + d0m) / L < 2.5. By controlling the relationship between the outer diameter of the image-side side (i.e., the rear end face of the rear lens barrel), the inner diameter of the image-side side (i.e., the rear end face of the rear lens barrel), and the length of the lens barrel on the optical axis, the outer diameter of the lens barrel can be effectively controlled, which is beneficial for miniaturizing the optical imaging lens and also makes the assembly of the optical imaging lens easier.

[0063] In an exemplary embodiment, at least one of the rear end face of the front lens barrel and the front end face of the rear lens barrel has an extension. The extension includes at least one object-side face facing the object side and perpendicular to the optical axis, and at least one image-side face facing the image side and perpendicular to the optical axis. This extension ensures stable bonding between the front and rear lens barrels under relevant technologies, resulting in more stable reliability of the optical imaging lens barrel.

[0064] In an exemplary embodiment, the inner diameter d0am of the rear end face of the front lens barrel, the inner diameter d0bs of the front end face of the rear lens barrel, and the thickness T14 of the first to fourth lenses on the optical axis satisfy -2.0 < (d0am - d0bs) / T14 < 2.0, wherein the thickness T14 of the first to fourth lenses on the optical axis is equal to the sum of the air gap T12 between the first and second lenses on the optical axis, the center thickness CT2 of the second lens on the optical axis, the air gap T23 between the second and third lenses on the optical axis, the center thickness CT3 of the third lens on the optical axis, and the air gap T34 between the third and fourth lenses on the optical axis. By controlling the relationship between the inner diameter of the rear end face of the front lens barrel, the inner diameter of the front end face of the rear lens barrel, and the thickness of the first to fourth lenses on the optical axis, the matching between the rear end of the front lens barrel and the front end of the rear lens barrel can be ensured, thereby ensuring the subsequent performance bonding of multiple components.

[0065] In an exemplary embodiment, the outer diameter D0am of the rear end face of the front lens barrel, the outer diameter D0bs of the front end face of the rear lens barrel, the effective focal length f1 of the first lens, the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, and the outer diameter D0s of the object side face of the lens barrel satisfy 1.0 < (D0am + D0bs) / (f2 + f3) - D0s / f1 < 5.0. In the example, 2.5 < (D0am + D0bs) / (f2 + f3) - D0s / f1 < 4.0. By controlling the relationship between the outer diameter of the rear end face of the front lens barrel, the outer diameter of the front end face of the rear lens barrel, the effective focal length of the first lens, the effective focal length of the second lens, the effective focal length of the third lens, and the outer diameter of the object side face of the lens barrel, the outer diameter of each lens barrel can be effectively controlled, thereby achieving miniaturization of the optical imaging lens while meeting optical performance requirements.

[0066] In an exemplary embodiment, the optical imaging lens may include at least five spacer elements, wherein at least one spacer element is disposed between the first lens and the fourth lens, and at least two spacer elements are disposed between the sixth lens and the eighth lens. By disposing of at least one spacer element between the first lens and the fourth lens, stray light ingress can be minimized without sacrificing illumination. By disposing of at least two spacer elements between the sixth lens and the eighth lens, non-effective path light rays of the lens can be effectively blocked, preventing light leakage and the generation of other stray light, thereby improving the imaging quality of the optical imaging lens.

[0067] In an exemplary embodiment, the optical imaging lens may include a second spacer element located on the image-side side of the second lens and at least partially in contact with the second lens. By positioning the second spacer element close to the image-side side of the second lens, stray light ingress can be minimized without sacrificing illumination, thereby improving the imaging quality of the optical imaging lens.

[0068] In an exemplary embodiment, the optical imaging lens may include a third spacer element located on the image-side side of a third lens and in at least partial contact with the third lens. By positioning the third spacer element close to the image-side side of the third lens, stray light ingress can be minimized without sacrificing illumination, thereby improving the imaging quality of the optical imaging lens.

[0069] In an exemplary embodiment, the optical imaging lens may include a fourth spacer element located on the image-side surface of the fourth lens and at least partially in contact with the fourth lens. By positioning the fourth spacer element close to the image-side surface of the fourth lens, non-effective path light rays of the lens can be effectively blocked, preventing light leakage and the generation of other stray light, thereby improving the imaging quality of the optical imaging lens.

[0070] In an exemplary embodiment, the optical imaging lens may include a fifth spacer element located on the image-side surface of the fifth lens and at least partially in contact with the fifth lens. By positioning the fifth spacer element close to the image-side surface of the fifth lens, non-effective path light rays of the lens can be effectively blocked, preventing light leakage and the generation of other stray light, thereby improving the imaging quality of the optical imaging lens.

[0071] In an exemplary embodiment, a sixth spacer element and a seventh spacer element are disposed between the sixth lens and the eighth lens. The sixth spacer element is located on the image-side surface of the sixth lens and is at least partially in contact with the sixth lens, and the seventh spacer element is located on the image-side surface of the seventh lens and is at least partially in contact with the seventh lens. By providing at least one spacer element on the image-side surface of the sixth lens and the image-side surface of the seventh lens, non-effective path light rays of the lens can be effectively blocked, preventing light leakage and the generation of other stray light, thereby improving the imaging quality of the optical imaging lens.

[0072] In an exemplary embodiment, the center thickness CT7 of the seventh lens on the optical axis, the center thickness CT8 of the eighth lens on the optical axis, the spacing EP67 between the sixth and seventh spacers on the optical axis, and the maximum thickness CP7 of the seventh spacer satisfy 0 < (CT7 + CT8) / (EP67 + CP7) < 3.5. In the example, 1.8 < (CT7 + CT8) / (EP67 + CP7) ≤ 3. By reasonably controlling the relationship between the center thickness of the seventh lens on the optical axis, the center thickness of the eighth lens on the optical axis, the spacing between the sixth and seventh spacers on the optical axis, and the maximum thickness of the seventh spacer, the thickness of the seventh and eighth lenses can be controlled. This, in turn, is more conducive to lens forming while ensuring strength. Simultaneously, limiting the thickness of the seventh spacer is more beneficial for achieving assembly stability.

[0073] In an exemplary embodiment, the sixth spacer element is the spacer element with the largest thickness among the spacer elements between the sixth lens and the eighth lens. The maximum thickness CP5 of the fifth spacer element, the maximum thickness CP6 of the sixth spacer element, the spacing EP56 between the fifth spacer element and the sixth spacer element on the optical axis, the central thickness CT5 of the fifth lens on the optical axis, the central thickness CT6 of the sixth lens on the optical axis, and the air spacing T56 between the fifth lens and the sixth lens on the optical axis satisfy 3.0 < (CP5 + CP6) / EP56 + (CT5 + CT6) / T56 < 10.0. In an example, 6.0 < (CP5 + CP6) / EP56 + (CT5 + CT6) / T56 < 10.0. By controlling the interrelationship among the maximum thickness of the fifth spacer element, the maximum thickness of the sixth spacer element, the spacing between the fifth spacer element and the sixth spacer element on the optical axis, the central thickness of the fifth lens on the optical axis, the central thickness of the sixth lens on the optical axis, and the air spacing between the fifth lens and the sixth lens on the optical axis, the ratio of the thickness to the spacing of the fifth spacer element and the sixth spacer element and the ratio of the thickness to the air spacing of the fifth lens and the sixth lens can be restricted, thereby controlling the spacing size of the spacer element and the central thickness size of the lens, which is beneficial to the molding and assembly of the fifth lens and the sixth lens.

[0074] In an exemplary embodiment, the inner diameter d5m of the image side surface of the fifth spacer element, the inner diameter d6s of the object side surface of the sixth spacer element, the curvature radius R10 of the image side surface of the fifth lens, and the curvature radius R11 of the object side surface of the sixth lens satisfy -1.0 < d5m / R10 + d6s / R11 < 0. In an example, -0.85 < d5m / R10 + d6s / R11 < -0.30. By reasonably controlling the interrelationship among the inner diameter of the image side surface of the fifth spacer element, the inner diameter of the object side surface of the sixth spacer element, the curvature radius of the image side surface of the fifth lens, and the curvature radius of the object side surface of the sixth lens, the ratio of the inner diameter of the object side surface of the spacer element to the curvature radius of the lens can be restricted, thereby improving the shielding of the non-effective diameter light rays of the lens by the spacer element to reduce the generation of light leakage and other stray light.

[0075] In an exemplary embodiment, the radius of curvature R12 of the image-side surface of the sixth lens, the effective focal length f6 of the sixth lens, the outer diameter D6m of the image-side surface of the sixth spacer element, the inner diameter d6m of the image-side surface of the sixth spacer element, the outer diameter D5m of the image-side surface of the fifth spacer element, and the inner diameter d5m of the image-side surface of the fifth spacer element satisfy -20.0 < (R12 × f6) / [(D6m - d6m) × (D5m - d5m)] < -3.0. By reasonably controlling the relationships between the radius of curvature R12 of the image-side surface of the sixth lens, the effective focal length of the sixth lens, the outer diameter of the image-side surface of the sixth spacer element, the inner diameter of the image-side surface of the sixth spacer element, and the outer diameter of the image-side surface of the fifth spacer element, the inner diameter of the image-side surface of the fifth spacer element, and the inner diameter of the image-side surface of the fifth spacer element, the strength of the sixth lens can be improved, thereby improving the assembly stability of the sixth lens and the sixth spacer element, and mitigating the low yield problem caused by the fit between the fifth lens, the sixth lens, the fifth spacer element, and the sixth spacer element.

[0076] In an exemplary embodiment, the outer diameter D4m of the image-side surface of the fourth spacer element, the outer diameter D5m of the image-side surface of the fifth spacer element, and the combined focal length f345 of the third, fourth, and fifth lenses satisfy 1.0 < (D4m + D5m) / f345 < 5.0. In the example, 2.0 < (D4m + D5m) / f345 < 4.0. By controlling the relationship between the outer diameters of the image-side surfaces of the fourth and fifth spacers and the combined focal length of the third, fourth, and fifth lenses, it is possible to reduce the influence of the third to fifth lenses on chromatic aberration while improving stray light at the positions of the fourth and fifth lenses.

[0077] In an exemplary embodiment, the optical imaging lens further includes a sixth auxiliary spacer element, which is located on the image-side side of the sixth spacer element and at least partially in contact with it. The outer diameter D6bm of the image-side side of the sixth auxiliary spacer element, the inner diameter d6bm of the image-side side of the sixth auxiliary spacer element, the air gap T67 between the sixth and seventh lenses on the optical axis, and the center thickness CT7 of the seventh lens on the optical axis satisfy 3.0 < (D6bm + d6bm) / (T67 + CT7) < 6.0. In the example, 4.8 < (D6bm + d6bm) / (T67 + CT7) < 5.7. By controlling the ratio of the bandwidth of the sixth auxiliary spacer element to the sum of the air gap between the sixth and seventh lenses on the optical axis and the center thickness of the seventh lens on the optical axis, sufficient bearing contact space can be ensured for the sixth auxiliary spacer element, thereby improving the stability of the assembly.

[0078] In an exemplary embodiment, the refractive index N7 of the seventh lens, the refractive index N8 of the eighth lens, the combined focal length f78 of the seventh and eighth lenses, the maximum thickness CP6b of the sixth auxiliary spacer element, and the optical axis spacing EP67 of the sixth and seventh spacers satisfy 5.0 < (N7 + N8) / (CP6b + EP67) × f78 < 20.0. In the example, 9.0 < (N7 + N8) / (CP6b + EP67) × f78 < 17.0. By reasonably controlling the interrelationships between the refractive index of the seventh lens, the refractive index of the eighth lens, the combined focal length of the seventh and eighth lenses, the maximum thickness of the sixth auxiliary spacer element, and the optical axis spacing of the sixth and seventh spacers, the shape of the seventh and eighth lenses can be effectively controlled, ensuring lens manufacturability. Furthermore, by limiting the inner diameter of the object-side surfaces of the sixth and seventh spacers, and ensuring good chromatic aberration curvature, the probability of stray light generation at the location of the seventh and eighth lenses can be further reduced.

[0079] In an exemplary embodiment, the dispersion coefficient V7 of the seventh lens, the dispersion coefficient V8 of the eighth lens, the outer diameter D7m of the image-side surface of the seventh spacer element, the inner diameter d7m of the image-side surface of the seventh spacer element, and the air gap T78 between the seventh and eighth lenses on the optical axis satisfy 0 < (V7 - V8) / (D7m - d7m) × T78 < 2.0. In the example, 0.3 < (V7 - V8) / (D7m - d7m) × T78 < 1.5. By controlling the relationship between the dispersion coefficients of the seventh and eighth lenses, the outer diameter of the image-side surface of the seventh spacer element, the inner diameter of the image-side surface of the seventh spacer element, and the air gap between the seventh and eighth lenses on the optical axis, the optical path range through the exiting seventh lens and the incident eighth lens can be reasonably limited, eliminating light rays with poor edge quality, effectively improving the stability of the assembly of the seventh and eighth lenses, reducing the sensitivity of the inter-lens assembly structure, and thus improving the imaging quality of the optical imaging lens.

[0080] The optical imaging lens according to the above embodiments of this application can employ multiple lenses, such as the eight lenses mentioned above. By rationally allocating the optical power, surface shape, center thickness of each lens, air gap between each lens, and spacer elements, the size of the optical imaging lens can be effectively reduced, the sensitivity of the optical imaging lens can be decreased, and the imaging quality, manufacturability, and assembly stability of the optical imaging lens can be improved.

[0081] In embodiments of this application, at least one of the mirror surfaces of each of the first to eighth lenses is an aspherical mirror surface. An aspherical lens is characterized by a continuously changing curvature from the lens center to the lens periphery. Unlike a spherical lens, which has a constant curvature from the lens center to the lens periphery, an aspherical lens has better radius of curvature characteristics, offering advantages in improving distortion aberrations and astigmatism. By using an aspherical lens, aberrations occurring during imaging can be eliminated as much as possible, thereby improving image quality. Optionally, the object-side and image-side surfaces of each of the third to sixth lenses are aspherical mirror surfaces.

[0082] However, those skilled in the art will understand that the various results and advantages described herein can be obtained by changing the number of lenses and spacers constituting the optical imaging lens without departing from the technical solutions claimed in this application. For example, although an embodiment is described using eight lenses and six spacers as an example, the optical imaging lens is not limited to including eight lenses and six spacers. If desired, the optical imaging lens may also include other numbers of lenses.

[0083] The following describes in further detail, with reference to the accompanying drawings, specific embodiments of the optical imaging lens applicable to the above-described embodiments.

[0084] First embodiment

[0085] The following is for reference Figures 2 to 8C Describes an optical imaging lens according to a first embodiment of this application. Figure 2 , Figure 3 Schematic diagrams of the optical imaging lens of Embodiment 1 according to the first embodiment of this application are shown in the Y-axis direction and the X-axis direction, respectively; Figure 4 , Figure 5 Schematic diagrams of the optical imaging lens of Embodiment 2 according to the first embodiment of this application are shown in the Y-axis direction and the X-axis direction, respectively; Figure 6 , Figure 7 The diagrams show the structure of the optical imaging lens of Embodiment 3 according to the first embodiment of this application in the Y-axis direction and the X-axis direction, respectively.

[0086] like Figures 2 to 7 As shown, the optical imaging lens, from the object side to the image side, includes, in sequence: a first lens E1, a second lens E2, a second spacer element P2, a third lens E3, a third spacer element P3, a fourth lens E4, a fourth spacer element P4, a fifth lens E5, a fifth spacer element P5, a sixth lens E6, a sixth spacer element P6, a sixth auxiliary spacer element P6b, a seventh lens E7, an eighth lens E8, a filter, and an imaging surface. The aperture stop STO can be positioned between the third lens E3 and the fourth lens E4 as needed.

[0087] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being convex. The fifth lens E5 has negative optical power, with its object-side surface S9 being concave and its image-side surface S10 being convex. The sixth lens E6 has negative optical power, with its object-side surface S11 being concave and its image-side surface S12 being concave. The seventh lens E7 has positive optical power, with its object-side surface S13 being convex and its image-side surface S14 being convex. The eighth lens E8 has negative optical power, with its object-side surface S15 being concave and its image-side surface S16 being convex. The filter has an object-side surface S17 and an image-side surface S18 (not shown in the figure). Light from the object passes through each surface S1 to S18 in sequence and is finally imaged on the imaging surface S19 (not shown in the figure).

[0088] Table 1 shows the basic parameters of the optical imaging lens of the first embodiment, wherein the units of radius of curvature, thickness / distance and focal length are all millimeters (mm).

[0089]

[0090] Table 1

[0091] In this embodiment, the total effective focal length of the optical imaging lens is f = 1.92 mm, the semi-FOVx of the optical imaging lens in the X-axis direction is 42.3°, and the semi-FOVy of the optical imaging lens in the Y-axis direction is 53.00°.

[0092] In the first embodiment, the object-side surface and image-side surface of any one of the third lens E3 to the sixth lens E6 are aspherical, and the surface shape x of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0093]

[0094] 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, A12 that can be used for each aspherical mirror S5-S12 in the first embodiment. 10 A 12 A 14 A 16 A 18 A20 A 22 A 24 A 26 A 28 and A 30 .

[0095]

[0096]

[0097] Table 2-1

[0098] Face number A18 A20 A22 A24 A26 A28 A30 S5 9.2197E-06 -2.9889E-05 -2.6108E-05 -2.5133E-05 -7.1594E-06 -9.6840E-06 0.0000E+00 S6 -1.5167E-05 2.1039E-05 -2.2324E-05 5.0704E-06 -1.3150E-05 0.0000E+00 0.0000E+00 S7 2.1064E-05 -1.3561E-05 4.3263E-06 -5.1711E-06 3.3741E-06 -1.0639E-06 0.0000E+00 S8 -1.6606E-05 2.0922E-06 -2.6259E-05 -4.2052E-06 -5.3306E-06 0.0000E+00 0.0000E+00 S9 -1.6606E-05 2.0922E-06 -2.6259E-05 -4.2052E-06 -5.3306E-06 0.0000E+00 0.0000E+00 S10 -3.4377E-04 1.1341E-04 2.1880E-06 2.2090E-05 -4.0205E-05 1.1490E-05 7.9812E-07 S11 -3.4377E-04 1.1341E-04 2.1880E-06 2.2090E-05 -4.0205E-05 1.1490E-05 7.9812E-07 S12 -8.3676E-04 2.6546E-04 -1.6469E-05 1.2326E-04 -6.5534E-05 2.3973E-05 -3.3791E-05

[0099] Table 2-2

[0100] In the first embodiment, the object-side surface and image-side surface of any one of the first lens E1, the second lens E2, the seventh lens E7, and the eighth lens E8 are both Q2D freeform surfaces. The surface shape of the Q2D freeform surface can be defined by, but is not limited to, the following Q2D freeform surface equations:

[0101]

[0102] Formula (2) above includes the off-axis conical base surface plus the external Q-free polynomial deviation, where the variable with a tilde (~) represents the parameter in the off-axis coordinate system. The specific meanings of the parameters in formula (2) are as follows:

[0103] It represents the total sagitta of a specific coordinate origin on the lens conical base surface along the direction of the surface normal. The coordinate origin can move within the YZ plane based on the conical base surface.

[0104] This represents the coordinates of a point on the surface in the cylindrical coordinate system, given the off-axis coordinate system.

[0105] Let represent the coordinates of a point on the surface in Cartesian coordinates in an off-axis coordinate system, for a given .

[0106] Let r be a variable, representing the distance from the normalized radius r in off-axis coordinates. norm The increased radial distance of the aspherical surface off-center express The offset,

[0107] This represents the sag of the lens cone base surface in the direction of the normal at the specific coordinate point as described above;

[0108] This represents the incremental deviation of the sag of the cone base surface at the origin along the surface normal direction.

[0109] Tables 3-1 to 3-3 provide numerical values ​​for some parameters of the optical imaging lenses in Examples 1 to 3 of the first embodiment. The parameters listed in Tables 3-1 to 3-3 are based on... Figure 1 The parameters listed in Tables 3-1 to 3-3 are measured using the annotation method shown. The unit of measurement is millimeters (mm).

[0110]

[0111]

[0112] Table 3-1

[0113] Example / parameter D7m d0m D0s D0m d0am D0am d0bs D0bs CP5 1-1 6.0400 6.5356 6.8421 7.4000 6.4445 7.0104 3.3727 5.8216 0.0180 1-2 5.3242 5.8197 6.4934 6.8522 4.6920 5.4334 2.1778 4.3934 0.0180 1-3 5.1979 5.6935 6.3556 6.5893 1.5202 5.0993 5.2227 5.8087 0.0180

[0114] Table 3-2

[0115] Example / parameter L EP56 CP6 CP6b EP67 CP7 La Lb 1-1 7.0130 0.7915 0.4223 0.0180 0.6613 0.0180 1.7345 5.5301 1-2 7.1123 0.7252 0.4765 0.0180 0.5959 0.0180 2.8000 4.6323 1-3 7.1123 0.7409 0.4850 0.0180 0.6408 0.0180 2.9336 4.4193

[0116] Table 3-3

[0117] Figure 8A The on-axis chromatic aberration curve of the optical imaging lens of the first embodiment is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the optical imaging lens. Figure 8B The astigmatism curve of the optical imaging lens of the first embodiment is shown, which represents the meridional image plane curvature and sagittal image plane curvature corresponding to different field of view angles. Figure 8C The distortion curve of the optical imaging lens of the first embodiment is shown, representing the distortion magnitude corresponding to different field of view angles. According to... Figures 8A to 8C It can be seen that the optical imaging lens provided in the first embodiment can achieve good imaging quality.

[0118] Second embodiment

[0119] The following is for reference Figures 9 to 15C Describes an optical imaging lens according to a second embodiment of this application. Figure 9 , Figure 10 Schematic diagrams of the optical imaging lens of Embodiment 1 according to the second embodiment of this application are shown in the Y-axis direction and the X-axis direction, respectively; Figure 11 , Figure 12 Schematic diagrams of the optical imaging lens of Embodiment 2 according to the second embodiment of this application are shown in the Y-axis direction and the X-axis direction, respectively; Figure 13 , Figure 14 Schematic diagrams of the optical imaging lens of Embodiment 3 according to the second embodiment of this application are shown in the Y-axis direction and the X-axis direction, respectively.

[0120] like Figures 9 to 14 As shown, the optical imaging lens, from the object side to the image side, includes, in sequence: a first lens E1, a second lens E2, a second spacer element P2, a third lens E3, a third spacer element P3, a fourth lens E4, a fourth spacer element P4, a fifth lens E5, a fifth spacer element P5, a sixth lens E6, a sixth spacer element P6, a sixth auxiliary spacer element P6b, a seventh lens E7, an eighth lens E8, a filter, and an imaging surface. The aperture stop STO can be positioned between the third lens E3 and the fourth lens E4 as needed.

[0121] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being convex. The fifth lens E5 has negative optical power, with its object-side surface S9 being concave and its image-side surface S10 being convex. The sixth lens E6 has negative optical power, with its object-side surface S11 being convex and its image-side surface S12 being concave. The seventh lens E7 has positive optical power, with its object-side surface S13 being concave and its image-side surface S14 being convex. The eighth lens E8 has negative optical power, with its object-side surface S15 being concave and its image-side surface S16 being convex. The filter has an object-side surface S17 and an image-side surface S18 (not shown in the figure). Light from the object passes sequentially through each surface S1 to S18 and is finally imaged onto the imaging surface S19 (not shown in the figure).

[0122] Table 4 shows the basic parameters of the optical imaging lens of the second embodiment, where the units for radius of curvature, thickness / distance, and focal length are all millimeters (mm).

[0123]

[0124] Table 4

[0125] In this embodiment, the total effective focal length of the optical imaging lens is f = 1.50 mm, the semi-FOVx of the optical imaging lens in the X-axis direction is 40.8°, and the semi-FOVy of the optical imaging lens in the Y-axis direction is 63.47°.

[0126] In the second embodiment, the object-side surface and image-side surface of any one of the third lens E3 to the sixth lens E6 are aspherical. Tables 5-1 and 5-2 give the higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror S5-S12 in the second embodiment. 10 A 12 A 14 A16 A 18 A 20 A 22 A 24 A 26 A 28 and A 30 .

[0127]

[0128]

[0129] Table 5-1

[0130] Face number A18 A20 A22 A24 A26 A28 A30 S5 -2.3503E-06 -3.5971E-05 -4.4399E-05 -2.5023E-05 -7.0025E-06 -1.0810E-06 0.0000E+00 S6 1.0847E-07 -9.2843E-06 -9.0195E-06 -4.3937E-06 -1.5867E-06 0.0000E+00 0.0000E+00 S7 -8.1954E-06 4.0272E-07 1.1949E-06 5.5013E-07 -1.3490E-06 1.7460E-07 0.0000E+00 S8 4.7757E-06 -2.5692E-05 -2.1980E-05 -1.0742E-05 -1.7363E-06 0.0000E+00 0.0000E+00 S9 -6.5667E-05 -2.2537E-05 -1.2028E-05 -2.0668E-05 -1.1117E-05 -3.6260E-06 2.0840E-07 S10 -1.5672E-04 1.1097E-04 4.8104E-06 -3.6269E-05 -4.6470E-06 -3.9638E-07 8.2370E-06 S11 -1.6904E-04 3.4730E-04 6.2786E-05 1.8793E-05 -3.4912E-05 -1.1238E-05 6.6268E-06 S12 -2.1046E-04 -2.4554E-04 2.3748E-04 5.2037E-05 -2.7341E-05 -3.5153E-05 -2.6634E-06

[0131] Table 5-2

[0132] In the second embodiment, the object-side surface and image-side surface of any one of the first lens E1, the second lens E2, the seventh lens E7 and the eighth lens E8 are both Q2D freeform surfaces.

[0133] Tables 6-1 to 6-3 provide numerical values ​​for some parameters of the optical imaging lenses in Examples 1 to 3 of the second embodiment. The parameters listed in Tables 6-1 to 6-3 are based on... Figure 1 The parameters listed in Tables 6-1 to 6-3 are measured using the annotation method shown. The unit of measurement is millimeters (mm).

[0134] Example / parameter D4m d5m D5m d6s d6m D6m d6bm D6bm d7m 2-1 5.4200 1.8315 5.5800 3.4424 4.0316 5.6200 3.1349 5.8400 3.7055 2-2 5.2700 1.8982 5.4300 3.5406 4.1373 5.4700 3.1892 5.6900 3.6881 2-3 4.0044 1.9581 5.3700 3.6580 4.0547 5.4100 3.2433 5.6300 3.6781

[0135] Table 6-1

[0136] Example / parameter D7m d0m D0s D0m d0am D0am d0bs D0bs CP5 2-1 6.1000 6.5956 6.9021 7.4600 6.5045 7.0704 3.4327 5.8816 0.0180 2-2 5.9500 6.4456 7.0099 7.3600 6.5045 6.9885 3.5568 5.7959 0.0180 2-3 5.8900 6.3856 7.1230 7.3600 6.5045 7.0301 3.6369 5.7032 0.0180

[0137] Table 6-2

[0138] Example / parameter L EP56 CP6 CP6b EP67 CP7 La Lb 2-1 6.4084 0.5678 0.4245 0.0180 0.6613 0.0180 1.7345 4.9256 2-2 6.3539 0.5617 0.4215 0.0180 0.5877 0.0180 1.7345 4.8711 2-3 6.3932 0.5233 0.4593 0.0180 0.5114 0.0180 1.6267 4.9104

[0139] Table 6-3

[0140] Figure 15A The on-axis chromatic aberration curve of the optical imaging lens of the second embodiment is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the optical imaging lens. Figure 15B The astigmatism curve of the optical imaging lens of the second embodiment is shown, which represents the meridional image plane curvature and sagittal image plane curvature corresponding to different field of view angles. Figure 15C The distortion curve of the optical imaging lens of the second embodiment is shown, representing the distortion magnitude corresponding to different field of view angles. According to... Figures 15A to 15C It can be seen that the optical imaging lens provided in the second embodiment can achieve good imaging quality.

[0141] Third embodiment

[0142] The following is for reference Figures 16 to 22C Describes an optical imaging lens according to a third embodiment of this application. Figure 16 , Figure 17 Schematic diagrams of the optical imaging lens of Embodiment 1 according to the third embodiment of this application are shown in the Y-axis direction and the X-axis direction, respectively; Figure 18 , Figure 19 Schematic diagrams of the optical imaging lens of Embodiment 2 according to the third embodiment of this application are shown in the Y-axis direction and the X-axis direction, respectively; Figure 20 , Figure 21 Schematic diagrams of the optical imaging lens of Embodiment 3 according to the third embodiment of this application are shown in the Y-axis direction and the X-axis direction, respectively.

[0143] like Figures 16 to 21 As shown, the optical imaging lens, from the object side to the image side, includes, in sequence: a first lens E1, a second lens E2, a second spacer element P2, a third lens E3, a third spacer element P3, a fourth lens E4, a fourth spacer element P4, a fifth lens E5, a fifth spacer element P5, a sixth lens E6, a sixth spacer element P6, a sixth auxiliary spacer element P6b, a seventh lens E7, an eighth lens E8, a filter, and an imaging surface. The aperture stop STO can be positioned between the third lens E3 and the fourth lens E4 as needed.

[0144] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being convex. The fifth lens E5 has negative optical power, with its object-side surface S9 being concave and its image-side surface S10 being convex. The sixth lens E6 has negative optical power, with its object-side surface S11 being convex and its image-side surface S12 being concave. The seventh lens E7 has positive optical power, with its object-side surface S13 being concave and its image-side surface S14 being convex. The eighth lens E8 has negative optical power, with its object-side surface S15 being concave and its image-side surface S16 being convex. The filter has an object-side surface S17 and an image-side surface S18 (not shown in the figure). Light from the object passes sequentially through each surface S1 to S18 and is finally imaged onto the imaging surface S19 (not shown in the figure).

[0145] Table 7 shows the basic parameters of the optical imaging lens of the third embodiment, where the units for radius of curvature, thickness / distance, and focal length are all millimeters (mm).

[0146]

[0147]

[0148] Table 7

[0149] In this embodiment, the total effective focal length of the optical imaging lens is f = 1.55 mm, the semi-FOVx of the optical imaging lens in the X-axis direction is 41.5°, and the semi-FOVy of the optical imaging lens in the Y-axis direction is 57.50°.

[0150] In the third embodiment, the object-side surface and image-side surface of any one of the lenses, from the third lens E3 to the sixth lens E6, are aspherical. Tables 8-1 and 8-2 give the higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror S5-S12 in the third embodiment. 10 A 12 A 14 A 16 A 18 A 20 A 22 A 24 A 26 A 28 and A 30 .

[0151] Face number A4 A6 A8 A10 A12 A14 A16 S5 3.3230E-02 -8.8764E-03 9.4060E-04 8.8671E-04 1.0864E-04 -1.9370E-05 -2.8138E-05 S6 -2.4996E-02 1.9237E-03 2.0419E-04 -8.0511E-06 9.6518E-06 1.5102E-05 -1.0662E-05 S7 -1.7747E-02 2.0096E-04 1.0075E-04 7.5491E-05 3.7321E-05 1.4306E-05 1.6932E-05 S8 -1.3034E-01 -2.5029E-03 7.9652E-05 1.1153E-03 4.4534E-04 2.8118E-04 9.2387E-05 S9 -1.3216E-01 -2.0473E-03 -1.5798E-04 1.3440E-03 4.1384E-04 -9.7597E-05 -1.6944E-04 S10 4.1574E-02 -9.7306E-04 1.1488E-02 -4.8290E-03 2.3536E-03 -1.0365E-03 1.0137E-04 S11 -1.9961E-01 -5.8690E-02 6.9812E-03 -1.4873E-02 4.2538E-03 -1.9276E-03 1.3505E-03 S12 -9.0270E-01 6.3470E-02 -2.9421E-02 2.0352E-03 -2.6350E-03 6.9286E-04 1.0329E-03

[0152] Table 8-1

[0153] Face number A18 A20 A22 A24 A26 A28 A30 S5 -1.4863E-05 -1.7387E-05 -2.5818E-05 -3.0098E-05 -2.1734E-05 -7.3925E-06 0.0000E+00 S6 2.8413E-06 1.1801E-05 -4.9361E-06 -1.0960E-05 -4.7995E-06 0.0000E+00 0.0000E+00 S7 5.3280E-06 5.3440E-06 -3.1216E-06 -2.8935E-06 -3.2131E-06 -6.3610E-08 0.0000E+00 S8 -3.8009E-05 -2.3857E-05 -1.7690E-05 -1.0635E-05 -4.3007E-06 0.0000E+00 0.0000E+00 S9 -1.9373E-04 1.1548E-06 3.9497E-05 4.4631E-07 -2.0808E-05 -1.9379E-05 -5.1420E-06 S10 -3.7472E-04 3.1446E-04 -4.9939E-05 -3.3186E-05 -5.3627E-05 1.8007E-05 2.2580E-05 S11 -4.2912E-04 6.0277E-04 -7.3111E-05 1.0373E-04 -9.2184E-05 1.5505E-05 1.7064E-07 S12 -4.1506E-04 -3.7352E-04 2.4190E-04 2.7165E-04 -1.4335E-04 -2.8654E-05 -1.6589E-05

[0154] Table 8-2

[0155] In the third embodiment, the object-side surface and image-side surface of any one of the first lens E1, the second lens E2, the seventh lens E7 and the eighth lens E8 are both Q2D freeform surfaces.

[0156] Tables 9-1 to 9-3 provide numerical values ​​for some parameters of the optical imaging lenses in Embodiments 1 to 3 of the third implementation. The parameters listed in Tables 9-1 to 9-3 are based on... Figure 1 The parameters listed in Tables 9-1 and 9-2 are measured using the annotation method shown. The unit of measurement is millimeters (mm).

[0157]

[0158]

[0159] Table 9-1

[0160] Example / parameter D7m d0m D0s D0m d0am D0am d0bs D0bs CP5 3-1 6.0000 6.4556 7.1303 7.3600 6.4045 7.0607 2.9834 5.7096 0.0180 3-2 5.8736 6.3692 6.9276 7.3600 6.2209 6.6744 3.1319 5.4751 0.0180 3-3 6.0470 6.6127 7.4569 7.4225 6.7502 7.2037 3.3132 5.7794 0.0180

[0161] Table 9-2

[0162] Example / parameter L EP56 CP6 CP6b EP67 CP7 La Lb 3-1 7.1654 0.4468 0.3762 0.0180 0.9108 0.0180 1.8132 5.6039 3-2 7.1654 0.4038 0.3612 0.0180 0.9399 0.0180 1.8132 5.6039 3-3 7.1654 0.4062 0.3304 0.0180 0.9415 0.0180 1.1832 5.6039

[0163] Table 9-3

[0164] Figure 22A The on-axis chromatic aberration curve of the optical imaging lens of the third embodiment is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the optical imaging lens. Figure 22B The astigmatism curve of the optical imaging lens of the third embodiment is shown, which represents the meridional image plane curvature and sagittal image plane curvature corresponding to different field of view angles. Figure 22C The distortion curve of the optical imaging lens of the third embodiment is shown, which represents the distortion magnitude corresponding to different field of view angles. According to... Figures 22A to 22C It can be seen that the optical imaging lens provided in the third embodiment can achieve good imaging quality.

[0165] In summary, the conditional expressions of each embodiment in the first to third embodiments satisfy the relationships shown in Table 10.

[0166]

[0167] Table 10

[0168] This application also provides an imaging device, wherein the electronic photosensitive element can be a photocoupled device (CCD) or a complementary metal oxide semiconductor device (CMOS). The imaging device can be a stand-alone imaging device such as a digital camera, or an imaging module integrated into a mobile electronic device such as a mobile phone. The imaging device is equipped with the optical imaging lens described above.

[0169] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. An optical imaging lens, comprising a lens barrel and a lens group, the lens group comprising eight lenses, the eight lenses being sequentially arranged along the optical axis from the object side to the image side as 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; characterized in that, The first lens has negative optical power; The second lens has positive optical power; The third lens has positive optical power, and its object side is convex, as is its image side; The fourth lens has positive optical power, and its object side is convex, as is its image side; The fifth lens has negative optical power, and its object side is concave while its image side is convex. The sixth lens has negative optical power and its image-side surface is concave. The seventh lens has positive optical power; The eighth lens has negative optical power; The optical imaging lens has eight lenses with optical power. At least one spacer element is provided between the first lens and the fourth lens; At least three spacer elements are provided between the sixth lens and the eighth lens. The at least three spacer elements include a sixth spacer element located on the image side of the sixth lens and in at least partial contact with the sixth lens, a sixth auxiliary spacer element located on the image side of the sixth spacer element and in at least partial contact with the sixth spacer element, and a seventh spacer element located on the image side of the seventh lens and in at least partial contact with the seventh lens. Wherein, the center thickness CT7 of the seventh lens on the optical axis, the center thickness CT8 of the eighth lens on the optical axis, the spacing EP67 of the sixth and seventh spacers on the optical axis and the maximum thickness CP7 of the seventh spacer satisfy 1.8 < (CT7 + CT8) / (EP67 + CP7) ≤ 3; The outer diameter D6bm of the image side of the sixth auxiliary spacer element, the inner diameter d6bm of the image side of the sixth auxiliary spacer element, the air gap T67 between the sixth lens and the seventh lens on the optical axis, and the center thickness CT7 of the seventh lens on the optical axis satisfy 4.8 < (D6bm + d6bm) / (T67 + CT7) ≤ 5.

65.

2. The optical imaging lens according to claim 1, characterized in that, At least one of the first to the eighth lenses is a freeform lens.

3. The optical imaging lens according to claim 1, characterized in that, The lens barrel is a split lens barrel, which includes a front lens barrel and a rear lens barrel. Both the front lens barrel and the rear lens barrel have a front end face that is closest to the object side and perpendicular to the optical axis, and a rear end face that is closest to the image side and perpendicular to the optical axis.

4. The optical imaging lens according to claim 3, characterized in that, At least one of the first to the eighth lenses is placed inside the front lens barrel, and the length La of the front lens barrel on the optical axis and the length Lb of the rear lens barrel on the optical axis satisfy 0.

2. <La / Lb<0.7。 5. The optical imaging lens according to claim 3, characterized in that, The outer diameter D0m of the image side of the lens tube, the inner diameter d0m of the image side of the lens tube, and the length L of the lens tube on the optical axis satisfy 1.7 < (D0m + d0m) / L ≤ 2.

19.

6. The optical imaging lens according to claim 3, characterized in that, The inner diameter d0am of the rear end face of the front lens barrel, the inner diameter d0bs of the front end face of the rear lens barrel, and the thickness T14 of the first lens to the fourth lens on the optical axis satisfy -1.81≤(d0am-d0bs) / T14≤1.

63.

7. The optical imaging lens according to claim 3, characterized in that, The outer diameter D0am of the rear end face of the front lens barrel, the outer diameter D0bs of the front end face of the rear lens barrel, the effective focal length f1 of the first lens, the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, and the outer diameter D0s of the object side face of the lens barrel satisfy 2.88≤(D0am+D0bs) / (f2+f3)-D0s / f1≤3.

76.

8. The optical imaging lens according to claim 1, characterized in that, Both the first lens and the second lens are freeform surface lenses.

9. The optical imaging lens according to claim 1, characterized in that, The optical imaging lens further includes a fifth spacer element located on the image side of the fifth lens. The sixth spacer element is the thickest spacer element among the spacers between the sixth lens and the eighth lens. The maximum thickness CP5 of the fifth spacer element, the maximum thickness CP6 of the sixth spacer element, the optical axis spacing EP56 between the fifth and sixth spacers, the center thickness CT5 of the fifth lens on the optical axis, the center thickness CT6 of the sixth lens on the optical axis, and the air spacing T56 between the fifth and sixth lenses on the optical axis satisfy 6.15≤(CP5+CP6) / EP56+(CT5+CT6) / T56≤9.

66.

10. The optical imaging lens according to claim 9, characterized in that, The inner diameter d5m of the image-side surface of the fifth spacer element, the inner diameter d6s of the object-side surface of the sixth spacer element, the radius of curvature R10 of the image-side surface of the fifth lens, and the radius of curvature R11 of the object-side surface of the sixth lens satisfy -0.

85. <d5m / R10+d6s / R11≤-0.37。 11. The optical imaging lens according to claim 9, characterized in that, The radius of curvature R12 of the image-side surface of the sixth lens, the effective focal length f6 of the sixth lens, the outer diameter D6m of the image-side surface of the sixth spacer element, the inner diameter d6m of the image-side surface of the sixth spacer element, the outer diameter D5m of the image-side surface of the fifth spacer element, and the inner diameter d5m of the image-side surface of the fifth spacer element satisfy -12.71≤(R12×f6) / [(D6m-d6m)×(D5m-d5m)]≤-4.

50.

12. The optical imaging lens according to claim 9, characterized in that, The optical imaging lens also includes a fourth spacer element located on the image side of the fourth lens. The outer diameter D4m of the image side of the fourth spacer element, the outer diameter D5m of the image side of the fifth spacer element, and the combined focal length f345 of the third lens, the fourth lens, and the fifth lens satisfy 2.36≤(D4m+D5m) / f345≤3.

70.

13. The optical imaging lens according to claim 1, characterized in that, The refractive index N7 of the seventh lens, the refractive index N8 of the eighth lens, the combined focal length f78 of the seventh and eighth lenses, the maximum thickness CP6b of the sixth auxiliary spacer element, and the spacing EP67 of the sixth and seventh spacers on the optical axis satisfy 9.61≤(N7+N8) / (CP6b+EP67)×f78≤16.

52.

14. The optical imaging lens according to claim 1, characterized in that, The dispersion coefficient V7 of the seventh lens, the dispersion coefficient V8 of the eighth lens, the outer diameter D7m of the image-side surface of the seventh spacer element, the inner diameter d7m of the image-side surface of the seventh spacer element, and the air gap T78 between the seventh lens and the eighth lens on the optical axis satisfy 0.3 < (V7 - V8) / (D7m - d7m) × T78 ≤ 1.32.

Images