Optical imaging device

Abstract

The utility model provides an optical imaging device, which comprises a lens group, a spacing element group and a lens barrel, and is characterized in that the inner diameter d0s of the object side end surface of the lens barrel and the curvature radius R1 of the object side surface of a first lens meet the following conditions:-0.9 lt; d0s / R1lt; -0.6%; the inner diameter d1s of the object side surface of the first spacing element and the curvature radius R2 of the image side surface of the first lens meet the following formula:-0.7 lt; d1s / R2lt; and-0.6. The problem of poor imaging effect caused by unreasonable front-end light distribution in an ultra-wide-angle and large-aperture optical imaging device in the prior art is solved.

Description

Technical Field

[0001] This utility model relates to the field of optical imaging equipment technology, and more specifically, to an optical imaging device. Background Technology

[0002] In current technological fields, optical imaging devices play a crucial role in applications such as wearable devices. The front-end lens of ultra-wide-angle, large-aperture optical imaging devices controls the overall imaging quality, directly affecting the initial refraction of light and the subsequent focusing path. Properly setting the optical parameters of the front-end lens can capture a wider field of view and provide better imaging performance in low-light environments, making it widely favored. However, when the curvature radii of the object-side and image-side of the front-end lens are similar, the lens is prone to optical problems such as insufficient light refraction, decreased focusing ability, and reduced MTF (modulation transfer function). Therefore, controlling the shape of the front-end lens, lens barrel, and spacer elements of ultra-wide-angle, large-aperture optical imaging devices, and adjusting the distribution of front-end light while improving imaging quality, is a very important issue. Utility Model Content

[0003] The main purpose of this invention is to provide an optical imaging device to solve the problem of poor imaging effect caused by unreasonable front-end light distribution in existing ultra-wide-angle and large-aperture optical imaging devices.

[0004] To achieve the above object, according to one aspect of the present utility model, an optical imaging device is provided. The number of lenses with optical power in the optical imaging device is eight. The optical imaging device includes: a lens group, from the object side to the image side of the optical imaging device, the lens group includes the first lens to the eighth lens arranged at intervals in sequence. The object side surface of the first lens is concave, and the image side surface of the first lens is convex; a spacer element group, the spacer element group at least includes a first spacer element located between the first lens and the second lens and at least partially contacting the image side surface of the first lens, a second spacer element located between the second lens and the third lens and at least partially contacting the image side surface of the second lens, and a third spacer element located between the third lens and the fourth lens and at least partially contacting the image side surface of the third lens; a lens barrel, the lens group and the spacer element group are accommodated in the lens barrel. Along the direction of the optical axis of the optical imaging device, the inner ring surface of the lens barrel is stepped; wherein, half of the maximum field angle of the optical imaging device Semi-FOV and the numerical aperture FNO of the optical imaging device satisfy: 3.25 < FNO × TAN(Semi-FOV) ≤ 4.3; the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens are both negative values, and the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: 0.85 < R1 / R2 ≤ 1.3; the inner diameter d0s of the object side end surface of the lens barrel and the radius of curvature R1 of the object side surface of the first lens satisfy: -0.9 < d0s / R1 < -0.6; the inner diameter d1s of the object side surface of the first spacer element and the radius of curvature R2 of the image side surface of the first lens satisfy: -0.7 < d1s / R2 < -0.6.

[0005] According to another aspect of the present utility model, an optical imaging device is provided. The number of lenses with optical power in the optical imaging device is eight. The optical imaging device includes: a lens group, from the object side to the image side of the optical imaging device, the lens group includes the first lens to the eighth lens arranged at intervals in sequence. The object side surface of the first lens is concave, and the image side surface of the first lens is convex; a spacer element group, the spacer element group at least includes a first spacer element located between the first lens and the second lens and at least partially contacting the image side surface of the first lens, a second spacer element located between the second lens and the third lens and at least partially contacting the image side surface of the second lens, and a third spacer element located between the third lens and the fourth lens and at least partially contacting the image side surface of the third lens; a lens barrel, the lens group and the spacer element group are accommodated in the lens barrel. Along the direction of the optical axis of the optical imaging device, the inner ring surface of the lens barrel is stepped; wherein, half of the maximum field angle of the optical imaging device Semi-FOV and the numerical aperture FNO of the optical imaging device satisfy: 3.25 < FNO × TAN(Semi-FOV) ≤ 4.3; the central thickness CT3 of the third lens on the optical axis and the effective focal length f3 of the third lens satisfy: 0.1346 ≤ CT3 / f3 ≤ 0.1698.

[0006] Further, the inner diameter d0s of the object side end surface of the lens barrel, the inner diameter d1s of the object side surface of the first spacer element, and the central thickness CT1 of the first lens on the optical axis satisfy: 0.3 ≤ (d0s - d1s) / CT1 < 2.5.

[0007] Further, the distance EP01 from the object side end surface of the lens barrel to the object side surface of the first spacer element along the optical axis, the curvature radius R1 of the object side surface of the first lens, and the curvature radius R2 of the image side surface of the first lens satisfy: -0.7 ≤ (R1 - R2) / EP01 < 0.3.

[0008] Further, the effective diameter DT11 of the object side surface of the first lens, the inner diameter d0s of the object side end surface of the lens barrel, and the entrance pupil diameter EPD of the optical imaging device satisfy: 1.05 < (DT11 - d0s) / EPD < 2.3.

[0009] Further, the inner diameter d1s of the object side surface of the first spacer element, the outer diameter D1s of the object side surface of the first spacer element, and the effective diameter DT12 of the image side surface of the first lens satisfy: 0.35 < (D1s - d1s) / DT12 < 0.6.

[0010] Further, the central thickness CT2 of the second lens on the optical axis is the largest among the lenses of the optical imaging device. The central thickness CT1 of the first lens on the optical axis, the central thickness CT2 of the second lens on the optical axis, and the central thickness CT3 of the third lens on the optical axis satisfy: 0.9 < CT2 / (CT1 + CT3) < 1.05.

[0011] Furthermore, the inner diameter d2s of the object side surface of the second spacer element, the inner diameter d1m of the image side surface of the first spacer element, and the central thickness CT2 of the second lens on the optical axis satisfy: 0 < (d1m - d2s) / CT2 < 0.2.

[0012] Furthermore, the outer diameter D1m of the image side surface of the first spacer element, the outer diameter D2s of the object side surface of the second spacer element, and the effective focal length f2 of the second lens satisfy: -15 < f2 / (D2s - D1m) < -8.

[0013] Furthermore, the inner diameter d2s of the object side surface of the second spacer element and the radius of curvature R4 of the image side surface of the second lens satisfy: 0.6 < d2s / R4 < 0.9; the inner diameter d2m of the image side surface of the second spacer element and the radius of curvature R5 of the object side surface of the third lens satisfy: 0.4 < d2m / R5 < 0.6.

[0014] Furthermore, the distance EP12 from the image side surface of the first spacer element to the object side surface of the second spacer element in the direction of the optical axis and the effective focal length f2 of the second lens satisfy: -0.2 < EP12 / f2 < -0.10; the distance EP23 from the image side surface of the second spacer element to the object side surface of the third spacer element in the direction of the optical axis and the effective focal length f3 of the third lens satisfy: 0.1 < EP23 / f3 < 0.2.

[0015] Furthermore, the inner diameter d3s of the object side surface of the third spacer element, the outer diameter D3s of the object side surface of the third spacer element, and the effective diameter DT32 of the image side surface of the third lens satisfy: 0.8 < (D3s - d3s) / DT32 < 2.3.

[0016] Furthermore, the inner diameter d3s of the object side surface of the third spacer element and the effective focal length f3 of the third lens satisfy: 0.3 < d3s / f3 < 0.4.

[0017] Furthermore, the distance L from the object-side end face of the lens barrel to the image-side end face of the lens barrel in the optical axis direction, and the on-axis distance TD from the object-side surface of the first lens to the image-side surface of the eighth lens satisfy: 1.35 ≤ L / TD < 1.6. Applying the technical solution of the present invention, the number of lenses with optical power in the optical imaging device is eight. The optical imaging device includes a lens group, a spacer element group, and a lens barrel. From the object side to the image side of the optical imaging device, the lens group includes the first lens to the eighth lens arranged at intervals in sequence. The object-side surface of the first lens is concave, and the image-side surface of the first lens is convex; the spacer element group at least includes a first spacer element located between the first lens and the second lens and at least partially contacting the image-side surface of the first lens, a second spacer element located between the second lens and the third lens and at least partially contacting the image-side surface of the second lens, and a third spacer element located between the third lens and the fourth lens and at least partially contacting the image-side surface of the third lens; the lens group and the spacer element group are accommodated in the lens barrel, and along the optical axis direction of the optical imaging device, the inner ring surface of the lens barrel is stepped; wherein, half of the maximum field angle of the optical imaging device Semi-FOV, and the numerical aperture FNO of the optical imaging device satisfy: 3.25 < FNO × TAN(Semi-FOV) ≤ 4.3; the curvature radius R1 of the object-side surface of the first lens and the curvature radius R2 of the image-side surface of the first lens are both negative values, and the curvature radius R1 of the object-side surface of the first lens and the curvature radius R2 of the image-side surface of the first lens satisfy: 0.85 < R1 / R2 ≤ 1.3; the inner diameter d0s of the object-side end face of the lens barrel and the curvature radius R1 of the object-side surface of the first lens satisfy: -0.9 < d0s / R1 < -0.6; the inner diameter d1s of the object-side surface of the first spacer element and the curvature radius R2 of the image-side surface of the first lens satisfy: -0.7 < d1s / R2 < -0.6.

[0018] The optical imaging device of the present application uses eight lenses with optical power, and the first lens to the eighth lens are arranged in sequence at intervals. By restricting 3.25 < FNO × TAN(Semi-FOV) ≤ 4.3, the optical imaging device of the present application becomes an ultra-wide-angle large-aperture lens. The object side of the first lens is concave, and the image side of the first lens is convex. To optimize the light collection and focusing capabilities of the ultra-wide-angle and large-aperture optical imaging device, it is ensured that the optical imaging device can provide high-quality imaging even at the maximum field of view angle and large aperture. At the same time, to optimize the ultra-wide-angle and large-aperture performance of the optical imaging device, it is necessary to satisfy that the curvature radius of the object side of the first lens and the curvature radius of the image side of the first lens are both negative and satisfy 0.85 < R1 / R2 ≤ 1.3. At this time, the curvature radii of the object side and the image side of the first lens are similar, which easily causes insufficient refraction of the light entering the optical imaging device by the first lens, and then insufficient focusing capabilities of the light in the meridional plane and sagittal plane of the first lens, resulting in unclear imaging of the optical imaging device and seriously reducing the MTF parameter of the imaging. At this time, by restricting the optical imaging device to satisfy -0.9 < d0s / R1 < -0.6 and -0.7 < d1s / R2 < -0.6, the relationship between the inner diameter of the object-side end face of the lens barrel and the curvature radius of the object side of the first lens and the relationship between the inner diameter of the object side of the first spacer element and the curvature radius of the image side of the first lens can be restricted synchronously. The step difference between the inner diameter of the object-side end face of the lens barrel and the inner diameter of the object side of the first spacer element can be controlled within a reasonable range, and the amount of light and the light distribution passing through the object side and the image side of the first lens can be further controlled, thereby improving the MTF of the optical imaging device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0020] Figure 1 It shows a partial parameter schematic diagram of the optical imaging device of any optional embodiment of the present invention;

[0021] Figure 2 It shows a schematic structural diagram of the optical imaging device of Embodiment 1 of the present invention;

[0022] Figure 3 It shows a schematic structural diagram of the optical imaging device of Embodiment 2 of the present invention;

[0023] Figure 4 It shows a schematic structural diagram of the optical imaging device of Embodiment 3 of the present invention;

[0024] Figures 5 to 7The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the optical imaging device of Embodiment 1 are shown respectively.

[0025] Figure 8 A schematic diagram of the structure of the optical imaging device according to Embodiment 4 of this utility model is shown;

[0026] Figure 9 A schematic diagram of the structure of the optical imaging device according to Embodiment 5 of this utility model is shown;

[0027] Figure 10 A schematic diagram of the structure of the optical imaging device according to Embodiment Six of this utility model is shown;

[0028] Figures 11 to 13 The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the optical imaging device of Embodiment 4 are shown respectively.

[0029] Figure 14 A schematic diagram of the structure of the optical imaging device according to Embodiment Seven of this utility model is shown;

[0030] Figure 15 A schematic diagram of the structure of the optical imaging device according to Embodiment 8 of this utility model is shown;

[0031] Figure 16 A schematic diagram of the structure of the optical imaging device according to Embodiment 9 of this utility model is shown;

[0032] Figures 17 to 19 The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the optical imaging device of Embodiment 7 are shown respectively.

[0033] Figure 20 The MTF curve of the optical imaging device of an optional embodiment of the present invention is shown under the conditions of FNO×TAN(Semi-FOV)=4.16, R1 / R2=1.30, d0s / R1=-0.81, and d1s / R2=-0.64.

[0034] Figure 21 The MTF curves of an optical imaging device in the prior art are shown under the conditions of FNO×TAN(Semi-FOV)=4.16, R1 / R2=1.30, d0s / R1=-0.38, and d1s / R2=-0.74.

[0035] Figure 22 The MTF curves of an optical imaging device in the prior art are shown under the conditions of FNO×TAN(Semi-FOV)=4.16, R1 / R2=1.30, d0s / R1=-1.24, and d1s / R2=-0.24.

[0036] The above figures include the following reference numerals:

[0037] P0, Lens tube; E1, First lens; P1, First spacer element; E2, Second lens; P2, Second spacer element; E3, Third lens; P3, Third spacer element; E4, Fourth lens; P4, Fourth spacer element; E5, Fifth lens; P5, Fifth spacer element; E6, Sixth lens; P6, Sixth spacer element; E7, Seventh lens; P7, Seventh spacer element; E8, Eighth lens; S1, Object-side surface of the first lens; S2, Image-side surface of the first lens; S3, Second... S4, the object-side surface of the second lens; S5, the object-side surface of the third lens; S6, the image-side surface of the third lens; S7, the object-side surface of the fourth lens; S8, the image-side surface of the fourth lens; S9, the object-side surface of the fifth lens; S10, the image-side surface of the fifth lens; S11, the object-side surface of the sixth lens; S12, the image-side surface of the sixth lens; S13, the object-side surface of the seventh lens; S14, the image-side surface of the seventh lens; S15, the object-side surface of the eighth lens; S16, the image-side surface of the eighth lens. Detailed Implementation

[0038] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0039] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0040] In this utility model, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not used to limit this utility model.

[0041] 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.

[0042] 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.

[0043] In this text, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface 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 position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The judgment of the surface shape in the paraxial region can be based on the judgment method of those with ordinary knowledge in this field, and the concavity and convexity are judged by the positive and negative values of the R value (R refers to the radius of curvature in the paraxial region, usually the R value on the lens database (lens data) in optical software). For the ocular side surface, when the R value is positive, it is judged as convex, and when the R value is negative, it is judged as concave; for the display side surface, when the R value is positive, it is judged as concave, and when the R value is negative, it is judged as convex.

[0044] In order to solve the problem that the light distribution at the front end in an ultra-wide-angle and large-aperture optical imaging device in the prior art is unreasonable, resulting in poor imaging effects, the present utility model provides an optical imaging device.

[0045] The first embodiment

[0046] As Figures 1 to 20 shown, the number of lenses with optical power in the optical imaging device is eight. The optical imaging device includes a lens group, a spacer element group, and a lens barrel. From the object side to the image side of the optical imaging device, the lens group includes the first lens to the eighth lens arranged at intervals in sequence. The object side surface of the first lens is concave, and the image side surface of the first lens is convex; the spacer element group at least includes a first spacer element located between the first lens and the second lens and at least partially contacting the image side surface of the first lens, a second spacer element located between the second lens and the third lens and at least partially contacting the image side surface of the second lens, and a third spacer element located between the third lens and the fourth lens and at least partially contacting the image side surface of the third lens; the lens group and the spacer element group are accommodated in the lens barrel. Along the direction of the optical axis of the optical imaging device, the inner ring surface of the lens barrel is stepped; wherein, half of the maximum field angle of the optical imaging device, Semi-FOV, and the numerical aperture of the optical imaging device, FNO, satisfy: 3.25 < FNO × TAN(Semi-FOV) ≤ 4.3; the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens are both negative values, and between the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens, it satisfies: 0.85 < R1 / R2 ≤ 1.3; between the inner diameter d0s of the object side end surface of the lens barrel and the radius of curvature R1 of the object side surface of the first lens, it satisfies: -0.9 < d0s / R1 < -0.6; between the inner diameter d1s of the object side surface of the first spacer element and the radius of curvature R2 of the image side surface of the first lens, it satisfies: -0.7 < d1s / R2 < -0.6.

[0047] The optical imaging device of the present application uses eight lenses with optical power, and the first lens to the eighth lens are arranged in sequence at intervals. By restricting 3.25 < FNO × TAN(Semi-FOV) ≤ 4.3, the optical imaging device of the present application becomes an ultra-wide-angle large-aperture lens. The object side of the first lens is concave, and the image side of the first lens is convex. To optimize the light collection and focusing ability of the ultra-wide-angle and large-aperture optical imaging device, it is ensured that the optical imaging device can provide high-quality imaging even at the maximum field angle and large aperture. At the same time, to optimize the ultra-wide-angle and large-aperture performance of the optical imaging device, it is necessary to satisfy that the curvature radius of the object side of the first lens and the curvature radius of the image side of the first lens are both negative and satisfy 0.85 < R1 / R2 ≤ 1.3. At this time, the curvature radii of the object side and the image side of the first lens are similar, which is likely to cause insufficient refraction of the light entering the optical imaging device by the first lens, and then the focusing ability of the light in the meridian plane and the sagittal plane of the first lens is insufficient, resulting in unclear imaging of the optical imaging device and seriously reducing the MTF parameter of the imaging. By restricting the optical imaging device to satisfy -0.9 < d0s / R1 < -0.6 and -0.7 < d1s / R2 < -0.6, the relationship between the inner diameter of the object-side end face of the lens barrel and the curvature radius of the object side of the first lens and the relationship between the inner diameter of the object side of the first spacer element and the curvature radius of the image side of the first lens can be synchronously restricted. The step difference between the inner diameter of the object-side end face of the lens barrel and the inner diameter of the object side of the first spacer element can be controlled within a reasonable range, and the amount and distribution of the light passing through the object side and the image side of the first lens can be further controlled, thereby improving the MTF of the optical imaging device.

[0048] Table 1 below gives the MTF curves of several optional embodiments of the present application and the optical imaging device in the prior art under different values of d0s / R1 and d1s / R2 under the conditions of FNO × TAN(Semi-FOV) = 4.16 and R1 / R2 = 1.30. The imaging quality of the optical imaging device can be visually evaluated through MTF analysis, and the imaging quality of the optical imaging device at different spatial frequencies is examined. The shape and height of the MTF curve reflect the transmission ability of the optical imaging device to different details.

[0049] Table 1

[0050] Scheme number Option 1 Option 2 Option 3 FNO×TAN(Semi-FOV) 4.16 4.16 4.16 R1 / R2 1.30 1.30 1.30 d0s / R1 -0.81 -0.38 -1.24 d1s / R2 -0.64 -0.74 -0.24 MTF curve Appendix Figure 20 Appendix Figure 21 Appendix Figure 22

[0051] The optical imaging devices shown in Solution 2 and Solution 3 belong to the prior art. For Solution 2, FNO × TAN(Semi-FOV) = 4.16, R1 / R2 = 1.30, d0s / R1 = -0.38, d1s / R2 = -0.74, as Figure 21As shown, the excessively large step difference between the inner diameter of the object-side end face of the lens barrel and the inner diameter of the object-side surface of the first spacer element leads to a large influx of light into the optical imaging device, resulting in a significant drop in the MTF curve. Scheme 3 has FNO×TAN(Semi-FOV) = 4.16, R1 / R2 = 1.30, d0s / R1 = -1.24, and d1s / R2 = -0.24. Figure 22 As shown, the step difference between the inner diameter of the object-side end face of the lens tube and the inner diameter of the object-side side face of the first spacer element is too small, resulting in a steeper light path and a significant decrease in the MTF curve.

[0052] The optical imaging device shown in Scheme 1 is an embodiment of this application. In Scheme 1, FNO×TAN(Semi-FOV) = 4.16, R1 / R2 = 1.30, d0s / R1 = -0.81, and d1s / R2 = -0.64. Figure 20 As shown, at this time, the difference between the inner diameter of the object-side end face of the lens tube and the inner diameter of the object-side side face of the first spacer element is reasonable, and the astigmatism of the optical imaging device is small.

[0053] In this embodiment, the inner diameter d0s of the object-side end face of the lens barrel, the inner diameter d1s of the object-side surface of the first spacer element, and the center thickness CT1 of the first lens on the optical axis satisfy the following condition: 0.3 ≤ (d0s - d1s) / CT1 < 2.5. If the value of (d0s - d1s) / CT1 is too large, the path angle of light entering the lens barrel and passing through the first spacer element becomes too steep, which will cause a large amount of scattering of edge light, thereby reducing the MTF value and affecting the image sharpness. If the value of (d0s - d1s) / CT1 is too small, the light path is too flat, resulting in insufficient reflection or refraction of light between the lenses, which also causes astigmatism and reduces image quality. By limiting (d0s-d1s) / CT1 within a reasonable range, the relationship between the inner diameter of the object-side end face of the lens barrel, the inner diameter of the object-side surface of the first spacer element, and the center thickness of the first lens on the optical axis can be constrained. This helps to intercept excess light entering the optical imaging device through the object-side end face of the lens barrel and the first spacer element, avoiding stray light generation in the lens structure area of ​​the optical imaging device. This effectively controls the brightness of the edge field of view, ensuring clear imaging even in dark environments and guaranteeing image quality. Furthermore, the center thickness of the first lens allows for better control of the air gap between the first and second lenses, effectively reducing imaging distortion.

[0054] In this embodiment, the distance EP01 from the object-side end face of the lens barrel to the object-side surface of the first spacer element along the optical axis, the radius of curvature R1 of the object-side surface of the first lens, and the radius of curvature R2 of the image-side surface of the first lens satisfy the following condition: -0.7 ≤ (R1-R2) / EP01 < 0.3. If the value of (R1-R2) / EP01 is too large, the difference in the radius of curvature between the object-side surface and the image-side surface of the first lens is too large, resulting in inaccurate focusing of light inside the lens barrel, causing spherical aberration and other aberrations, thereby affecting the image quality. If the value of (R1-R2) / EP01 is too small, the refractive power of the first lens is insufficient, the light path inside the lens barrel is poor, and aberrations are caused. By limiting (R1-R2) / EP01 within a reasonable range, the relationship between the distance along the optical axis from the object-side end face of the lens barrel to the object-side surface of the first spacer element, the radius of curvature of the object-side surface of the first lens, and the radius of curvature of the image-side surface of the first lens can be constrained. This helps to prevent the lens center of the object-side surface of the first lens from protruding beyond the object-side end face of the lens barrel, and avoids scratches or abrasions on the object-side surface of the first lens during assembly, transportation, and use, thus preventing a reduction in image quality. Furthermore, controlling the radius of curvature of both the object-side and image-side surfaces of the first lens helps to effectively focus light, effectively control spherical aberration, and improve image sharpness.

[0055] In this embodiment, the effective diameter DT11 of the object-side surface of the first lens, the inner diameter d0s of the object-side end face of the lens barrel, and the entrance pupil diameter EPD of the optical imaging device satisfy the following relationship: 1.05 < (DT11 - d0s) / EPD < 2.3. If the value of (DT11 - d0s) / EPD is too large, the optical imaging device cannot effectively intercept excess light, resulting in increased stray light in non-imaging areas and affecting the brightness and sharpness of the edge field of view. If the value of (DT11 - d0s) / EPD is too small, a large amount of light is intercepted when entering the lens barrel, and the entrance pupil diameter cannot be fully utilized, resulting in insufficient imaging light and affecting the brightness of the image. By limiting (DT11 - d0s) / EPD to a reasonable range, the relationship between the effective diameter of the object-side surface of the first lens, the inner diameter of the object-side end face of the lens barrel, and the entrance pupil diameter of the optical imaging device can be constrained, which helps to intercept excess light and allow the effective imaging beam to enter the optical imaging device. At the same time, adjusting the ratio between the effective diameter of the object side surface of the first lens and the inner diameter of the object side end face of the lens barrel can effectively reduce the risk of aberrations in the optical imaging device, such as spherical aberration, coma, and astigmatism, and further improve the imaging quality of the optical imaging device.

[0056] In this embodiment, the following relationship is satisfied among the inner diameter d1s of the object side surface of the first spacer element, the outer diameter D1s of the object side surface of the first spacer element, and the effective diameter DT12 of the image side surface of the first lens: 0.35 < (D1s - d1s) / DT12 < 0.6. If the value of (D1s - d1s) / DT12 is too large, the annulus width of the first spacer element is too wide, which not only increases the front aperture of the optical imaging device but also causes large aberrations in the transition region between the lens barrel and the lens, affecting the imaging quality. If the value of (D1s - d1s) / DT12 is too small, the annulus width of the first spacer element is too narrow, which not only results in insufficient structural strength of the first spacer element and a low yield rate in processing and forming but also leads to poor abutting stability between the first spacer element and the first lens. In addition, it is easy to cause light blocking in the transition region between the lenses, affecting the effective transmission of light. By restricting (D1s - d1s) / DT12 within a reasonable range, the relationship among the outer diameter of the object side surface of the first spacer element, the inner diameter of the object side surface of the first spacer element, and the effective diameter of the image side surface of the first lens can be constrained, which helps to effectively balance the relationship between the annulus width of the first spacer element and the effective diameter of the image side surface of the first lens on the premise of meeting mass production, ensuring the abutting stability while avoiding too small inner diameter of the first spacer element, resulting in interception of the effective imaging light at the edge of the first spacer element, causing incomplete imaging or edge vignetting.

[0057] In this embodiment, the central thickness CT2 of the second lens on the optical axis is the largest among the lenses of the optical imaging device. The following relationship is satisfied among the central thickness CT1 of the first lens on the optical axis, the central thickness CT2 of the second lens on the optical axis, and the central thickness CT3 of the third lens on the optical axis: 0.9 < CT2 / (CT1 + CT3) < 1.05. If the value of CT2 / (CT1 + CT3) is too large, the central thickness of the second lens is too large, the lens surfaces of adjacent lenses are too close, and the air gap is too small, resulting in interference between adjacent lens surfaces during the assembly or drop test. If the value of CT2 / (CT1 + CT3) is too small, it is not conducive to the aberration correction of the first three lenses. In addition, it is easy to cause light blocking in the transition region between the lenses, affecting the effective transmission of light. By restricting CT2 / (CT1 + CT3) within a reasonable range, the relationship among the central thicknesses of the first lens, the second lens, and the third lens can be constrained, and by adjusting their ratios, the effective focal length of a single lens can be accurately matched with the effective focal length of the optical imaging device, ensuring its high imaging quality.

[0058] In this embodiment, the inner diameter d2s of the object side surface of the second spacer element, the inner diameter d1m of the image side surface of the first spacer element, and the central thickness CT2 of the second lens on the optical axis satisfy: 0 < (d1m - d2s) / CT2 < 0.2. If the value of (d1m - d2s) / CT2 is too large, the light rays are significantly blocked in the transition region between the first spacer element and the second spacer element, resulting in a reduction in the amount of imaging light and affecting the clarity and brightness of the imaging. If the value of (d1m - d2s) / CT2 is too small, the light rays of adjacent lenses cannot be effectively isolated, resulting in light scattering in the transition region between the lenses. By restricting (d1m - d2s) / CT2 within a reasonable range, the relationship between the inner diameter of the image side surface of the first spacer element, the inner diameter of the object side surface of the second spacer element, and the central thickness of the second lens on the optical axis can be constrained, which helps to reduce the deviation of the imaging light rays between the lenses and further improve the relative illuminance and clarity of the imaging.

[0059] In this embodiment, the outer diameter D1m of the image side surface of the first spacer element, the outer diameter D2s of the object side surface of the second spacer element, and the effective focal length f2 of the second lens satisfy: -15 < f2 / (D2s - D1m) < -8. If the value of f2 / (D2s - D1m) is too large or too small, the effective focal length of the second lens does not match well with the overall focal length of the optical imaging device, causing aberration and affecting the clarity and accuracy of the imaging. By restricting f2 / (D2s - D1m) within a reasonable range, the relationship between the outer diameter of the image side surface of the first spacer element, the outer diameter of the object side surface of the second spacer element, and the effective focal length of the second lens can be constrained, which helps the effective focal length of the second lens to be accurately matched with the overall focal length of the optical imaging device and better enables the lens group to achieve high-quality imaging at a specific distance.

[0060] In this embodiment, the inner diameter d2s of the object side surface of the second spacer element and the radius of curvature R4 of the image side surface of the second lens satisfy: 0.6 < d2s / R4 < 0.9. If the value of d2s / R4 is too large, it will cause excessive divergence of light during the transition between the second lens and the third lens, increasing the risk of astigmatism and spherical aberration, and affecting the edge sharpness and overall contrast of the imaging device. At the same time, the light distribution inside the lens group may become uneven, further reducing the imaging quality. If the value of d2s / R4 is too small, when the light transitions from the second lens to the third lens, the light path becomes too steep, resulting in non-uniform distribution of light on the third lens, increasing the occurrence of coma and other aberrations, and affecting the imaging sharpness of the central field of view and the MTF value of the optical imaging device. By restricting d2s / R4 within a reasonable range, it is possible to ensure smooth transition of light between the second lens and the third lens, uniform light distribution, effectively reduce spherical aberration, coma and astigmatism, thereby improving the edge sharpness of the optical imaging device, the imaging quality of the central field of view, and the MTF value of the optical imaging device, achieving a high-definition and high-contrast imaging effect.

[0061] In the present embodiment, the inner diameter d2m of the image side surface of the second spacer element and the radius of curvature R5 of the object side surface of the third lens satisfy: 0.4 < d2m / R5 < 0.6. If the value of d2m / R5 is too large, the incident angle of light when entering the third lens becomes larger, increasing the risk of spherical aberration and coma. Especially for the light in the marginal field of view, it may not be effectively focused, reducing the imaging clarity and MTF value. If the value of d2m / R5 is too small, it limits the smooth transition of light from the second lens to the third lens, resulting in uneven distribution of light on the third lens, increasing astigmatism and other aberrations, and affecting the imaging effects of the central field of view and the marginal field of view. By restricting d2m / R5 within a reasonable range, it can ensure a gentle transition of light between the second spacer element and the third lens, and the light enters the third lens at a small incident angle, effectively reducing spherical aberration, coma and astigmatism, improving the imaging clarity and MTF value, and thus achieving high-quality imaging reproduction of the central field of view and the marginal field of view. In the present embodiment, the distance EP12 along the optical axis direction from the image side surface of the first spacer element to the object side surface of the second spacer element and the effective focal length f2 of the second lens satisfy: -0.2 < EP12 / f2 < -0.10. If the value of EP12 / f2 is too large, the focusing process of light on the second lens becomes too compact, reducing the focusing accuracy of light, increasing spherical aberration and astigmatism, and affecting the performance of the optical imaging device. If the value of EP12 / f2 is too small, it causes the focusing position of light on the second lens to deviate from the optimal position, affecting the imaging clarity and contrast. By restricting EP12 / f2 within a reasonable range, it can ensure that the focusing process of light on the second lens is neither too compact nor too loose, and the light is focused at the optimal path and angle, effectively controlling coma, spherical aberration and astigmatism, improving the imaging clarity, contrast and MTF value, and achieving high-quality imaging presentation.

[0062] In the present embodiment, the distance EP23 from the image side surface of the second spacer element to the object side surface of the third spacer element in the direction of the optical axis and the effective focal length f3 of the third lens satisfy: 0.1 < EP23 / f3 < 0.2. If the value of EP23 / f3 is too large, the position of the light ray deviates too much when entering the third lens, affecting the imaging clarity and the contrast of the central field of view. If the value of EP23 / f3 is too small, the focusing process of the light ray on the third lens becomes too compact, increasing astigmatism and other aberrations, affecting the imaging effect of the peripheral field of view. By restricting EP23 / f3 within a reasonable range, it can ensure a smooth transition of the light ray between the second spacer element and the third lens, the light ray enters the third lens with the optimal path and angle, effectively reducing spherical aberration, coma, and astigmatism, improving the imaging clarity, the contrast of the central field of view and the peripheral field of view, and achieving high-resolution and high-quality imaging presentation. In the present embodiment, the inner diameter d3s of the object side surface of the third spacer element, the outer diameter D3s of the object side surface of the third spacer element, and the effective diameter DT32 of the image side surface of the third lens satisfy: 0.8 < (D3s - d3s) / DT32 < 2.3. If the value of (D3s - d3s) / DT32 is too large, the annular width of the third spacer element is too wide, not only increasing the front aperture diameter of the optical imaging device, but also easily causing large aberrations in the transition region between the lenses, affecting the imaging quality. If the value of (D3s - d3s) / DT32 is too small, the annular width of the third spacer element is too narrow, the bearing area between the third spacer element and the third lens is too small, the assembly stability is poor, and it is also easy to cause light transmission obstruction, affecting the imaging clarity and brightness. By restricting (D3s - d3s) / DT32 within a reasonable range, the relationship between the outer diameter of the object side surface of the third spacer element, the inner diameter of the object side surface of the third spacer element, and the effective diameter of the image side surface of the third lens can be constrained, which helps to optimize the optical performance of the third lens, such as reducing coma, reducing astigmatism, and improving imaging resolution. At the same time, by restricting the third spacer element, it helps to make the optical imaging device thinner and lighter.

[0063] In the present embodiment, the inner diameter d3s of the object side surface of the third spacer element and the effective focal length f3 of the third lens satisfy: 0.3 < d3s / f3 < 0.4. If the value of d3s / f3 is too large, it is difficult to intercept the peripheral stray light between the third lens and the fourth lens, and at the same time, the focal length of the third lens cannot be fully utilized, resulting in light transmission obstruction, affecting the imaging clarity and brightness. If the value of d3s / f3 is too small, the third spacer element intercepts too much light, also affecting the imaging quality. By restricting d3s / f3 within a reasonable range, the relationship between the inner diameter of the object side surface of the third spacer element and the effective focal length of the third lens can be constrained, and the light ray emitted by the third lens is reasonably regulated by the third spacer element, avoiding the risk of serious astigmatism, blurred imaging, and low imaging quality caused by the third spacer element intercepting too much or too little light.

[0064] In this embodiment, the distance L from the object-side end face of the lens barrel to the image-side end face of the lens barrel along the optical axis, and the axial distance TD from the object-side surface of the first lens to the image-side surface of the eighth lens satisfy the following condition: 1.35 ≤ L / TD < 1.6. If the value of L / TD is too large, it will result in excessive protrusions at the object-side and image-side ends of the lens barrel, making them susceptible to damage during assembly, transportation, or use. Furthermore, it increases the risk of stray light generation at the object-side and image-side ends of the lens barrel, affecting image quality. If the value of L / TD is too small, the length of the lens barrel is insufficient to effectively protect the lens group. By limiting L / TD to a reasonable range, and by constraining the relationship between the distance from the object-side end face of the lens barrel to the image-side end face of the lens barrel along the optical axis, and the axial distance from the object-side surface of the first lens to the image-side surface of the eighth lens, it helps to reduce the risk of the object-side surface of the first lens and the image-side surface of the eighth lens protruding from the lens barrel. This avoids interference between the front and rear lenses and the assembly mold, preventing a decrease in reliability and image quality.

[0065] In this embodiment, the object-side surface of the first lens is concave, and the image-side surface of the first lens is convex. The second lens has negative optical power, the object-side surface of the second lens is convex, and the image-side surface of the second lens is concave. The third lens has positive optical power, the object-side surface of the third lens is convex, and the image-side surface of the third lens is convex. The object-side surface of the fourth lens is concave, and the image-side surface of the fourth lens is convex. The fifth lens has positive optical power, the object-side surface of the fifth lens is convex, and the image-side surface of the fifth lens is concave. The sixth lens has positive optical power, the object-side surface of the sixth lens is convex. The object-side surface of the seventh lens is convex, and the image-side surface of the seventh lens is concave. The eighth lens has positive optical power, the object-side surface of the eighth lens is concave, and the image-side surface of the eighth lens is convex.

[0066] In the design of optical imaging devices, the arrangement and surface shape of lens groups can optimize the trajectory and focusing effect of light to achieve high-quality imaging performance. Specifically, the object-side surface of the first lens is concave, causing the light to diverge initially upon entering the optical imaging device, thus appropriately widening the incident angle. The image-side surface of the first lens is convex, which helps in the initial focusing of light after it enters the optical imaging device. The second lens has negative optical power, a convex object-side surface, and a concave image-side surface, which further diverges the light, controls the light path, reduces aberrations, and helps to reduce spherical aberration and coma caused by the initial focusing of the first lens, ensuring a smooth transition of light to the third lens. The third lens has positive optical power, a convex object-side surface, and a convex image-side surface, which allows the light, after being diverged by the second lens, to be refocused by the third lens, further improving the converging effect of the light, helping to control the focusing of obliquely incident light, and improving the imaging quality of the meridional and sagittal planes. The fourth lens has a concave object-side surface and a convex image-side surface, allowing light rays to quickly refocus after diverging again upon reaching the third lens, reducing astigmatism and other higher-order aberrations. The fifth lens has positive optical power, a convex object-side surface, and a concave image-side surface, enabling it to refocus light rays, control the convergence point, and further reduce spherical and coma. The sixth lens also has positive optical power, with a convex object-side surface, facilitating fine-tuning of the light rays after passing through the fifth lens, improving focusing efficiency, reducing divergence at the final focusing point, and thus enhancing image sharpness and detail. The seventh lens has a convex object-side surface and a concave image-side surface, allowing for a final focusing adjustment of the light rays just before they reach the imaging surface, reducing divergence at the rear and ensuring a clear, sharp image on the imaging surface, improving contrast and resolution. Finally, the eighth lens has positive optical power. The object side of the eighth lens is concave, and the image side is convex. This avoids the diverging light rays from being too concentrated and producing an overly sharp focusing effect. By focusing through the convex surface of the image side of the eighth lens, it ensures that the light rays converge smoothly and accurately on the imaging surface, providing good focusing effect and imaging stability for the entire optical imaging device.

[0067] Optionally, the optical imaging device in the embodiments of this application can be simulated using software and / or tools such as ZEMAX and CODEV. Alternatively, the optical imaging device can be simulated using CODEV software. During the simulation process using software and / or tools as described above, the surface profile of each lens can be appropriately adjusted based on the surface profile of the software and / or tools used.

[0068] In this embodiment, each lens can be optionally set as a trimmed lens. The outer diameter surface of the trimmed lens has a trimmed structure and an untrimmed structure, and the outer diameter of the trimmed structure is smaller than that of the untrimmed structure. The outer diameter of the trimmed lens generally refers to the outer diameter of the untrimmed structure.

[0069] In this embodiment, each spacer element can be optionally set as a trimmed spacer element. The outer ring surface of the trimmed spacer element has a trimmed part and an untrimmed part, and the outer diameter of the trimmed part is smaller than that of the untrimmed part. The outer diameter of the trimmed spacer element generally refers to the maximum outer diameter of the untrimmed part.

[0070] Second Embodiment

[0071] As Figures 1 to 20 shown, the number of lenses with optical power in the optical imaging device is eight. The optical imaging device includes a lens group, a spacer element group, and a lens barrel. From the object side to the image side of the optical imaging device, the lens group includes the first lens to the eighth lens arranged at intervals in sequence; the spacer element group at least includes a first spacer element located between the first lens and the second lens and at least partially contacting the image side surface of the first lens, a second spacer element located between the second lens and the third lens and at least partially contacting the image side surface of the second lens, and a third spacer element located between the third lens and the fourth lens and at least partially contacting the image side surface of the third lens; the lens group and the spacer element group are accommodated in the lens barrel, and along the direction of the optical axis of the optical imaging device, the inner ring surface of the lens barrel is stepped; wherein, half of the maximum field angle Semi-FOV of the optical imaging device and the numerical aperture FNO of the optical imaging device satisfy: 3.25 < FNO × TAN(Semi-FOV) ≤ 4.3; the central thickness CT3 of the third lens on the optical axis and the effective focal length f3 of the third lens satisfy: 0.1346 ≤ CT3 / f3 ≤ 0.1698.

[0072] The optical imaging device of the present application uses eight lenses with optical power, and the first lens to the eighth lens are arranged and spaced in sequence. By restricting 3.25 < FNO × TAN(Semi-FOV) ≤ 4.3, the optical imaging device of the present application becomes an ultra-wide-angle large-aperture lens, which can optimize the light collection and focusing capabilities of the ultra-wide-angle and large-aperture optical imaging device, ensuring that the optical imaging device can provide high-quality imaging even at the maximum field angle and large aperture. However, problems such as uneven light collection, decreased focusing ability, and impaired imaging quality are likely to occur in ultra-wide-angle and large-aperture optical imaging devices due to the dispersion of the light path. By restricting CT3 / f3 within a reasonable range, the ratio of the central thickness of the third lens on the optical axis to the effective focal length of the third lens is constrained, which helps to more finely control the transition of light between the second lens and the third lens, and at the same time optimize the focusing effect of the third lens on light, reduce the aberration caused by the mismatch between the lens thickness and the focal length, and improve the imaging quality of the optical imaging device.

[0073] It should be noted that this embodiment also includes other conditional expressions from the above embodiments, which will not be elaborated here.

[0074] Optionally, the optical imaging device may further include protective glass for protecting the photosensitive element located on the imaging surface.

[0075] The optical imaging device in this application may employ multiple lenses, such as the eight lenses described above. In this application, at least one of the mirror surfaces of each lens is an aspherical mirror surface. An aspherical lens is characterized by a continuously changing curvature from its center to its periphery. Unlike a spherical lens, which has a constant curvature from its center to its periphery, an aspherical lens has superior curvature radius characteristics, offering advantages in improving distortion and astigmatism. By using aspherical lenses, aberrations occurring during imaging can be eliminated as much as possible, thereby improving image quality.

[0076] It should be noted that in the optical imaging device of this application, the spacer element located on the image side of the i-th lens and in at least partial contact with the image side of the i-th lens is the i-th spacer element, where i can be 1, 2, 3, 4, 5, 6, 7.

[0077] However, those skilled in the art will understand that the number of lenses constituting the optical imaging device can be varied to obtain the various results and advantages described herein without departing from the technical solutions claimed in this application. For example, although eight lenses have been described as an example in the embodiments, the optical imaging device is not limited to including eight lenses. If necessary, the optical imaging device may also include other numbers of lenses.

[0078] Figure 1 A schematic diagram showing the dimensions of an optical imaging device according to this application is provided. Figure 1 The parameters d1s, D2s, L, EP23, etc., are indicated to provide a clear and intuitive understanding of their meaning. To facilitate the description of the optical imaging device and the surface shape of specific lenses, these parameters will not be shown in the accompanying drawings when describing specific embodiments.

[0079] The following description, with reference to the accompanying drawings, further illustrates examples of specific surface shapes and parameters of the optical imaging apparatus applicable to the above embodiments.

[0080] It should be noted that any one of the examples in Embodiments 1 to 9 described below is applicable to all embodiments of this application.

[0081] Example 1

[0082] like Figure 2 The optical imaging apparatus of Embodiment 1 of this application is described in the figure. Figure 2 A schematic diagram of the optical imaging device of Embodiment 1 is shown.

[0083] like Figure 2 As shown, the optical imaging device includes, in sequence from the object side to the image side: a first lens E1, a first spacer element P1, a second lens E2, a second spacer element P2, a third lens E3, a third spacer element P3, a fourth lens E4, a fourth spacer element P4, a fifth lens E5, a fifth spacer element P5, a sixth lens E6, a sixth spacer element P6, a seventh lens E7, a seventh spacer element P7, and an eighth lens E8.

[0084] In this embodiment, the first lens E1 has positive optical power, its object-side surface S1 is concave, and its image-side surface S2 is convex. The second lens E2 has negative optical power, its object-side surface S3 is convex, and its image-side surface S4 is concave. The third lens E3 has positive optical power, its object-side surface S5 is convex, and its image-side surface S6 is convex. The fourth lens E4 has positive optical power, its object-side surface S7 is concave, and its image-side surface S8 is convex. The fifth lens E5 has positive optical power, its object-side surface S9 is convex, and its image-side surface S10 is concave. The sixth lens E6 has positive optical power, its object-side surface S11 is convex, and its image-side surface S12 is convex. The seventh lens E7 has negative optical power, its object-side surface S13 is convex, and its image-side surface S14 is concave. The eighth lens E8 has positive optical power. Its object-side surface S15 is concave, and its image-side surface S16 is convex. The optical imaging device also includes a filter with an object-side surface S17 and an image-side surface S18. Light rays from the object pass through S1 to S18 to reach the imaging plane IMG.

[0085] Table 2 shows the basic structural parameters of the optical imaging device in Embodiment 1, where the units for radius of curvature, thickness / distance, effective radius, and focal length are all millimeters (mm).

[0086] Table 2

[0087]

[0088]

[0089] 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. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0090]

[0091] Where x is the distance vector from the vertex of the aspherical surface along the optical axis at a height of h; c is the paraxial curvature of the aspherical surface, c = 1 / R (i.e., the paraxial curvature c is the reciprocal of the radius of curvature R in Table 2 above); k is the conic coefficient; Ai is the i-th order correction coefficient of the aspherical surface. Table 3 below gives the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24 and A26 that can be used for each aspherical mirror S1-S16 in Embodiment 1. The surface shape of each aspherical surface can be defined by formula (1) given in Embodiment 1 above. In this embodiment, the object-side surface and image-side surface of the first lens to the eighth lens are both aspherical surfaces.

[0092] Table 3

[0093]

[0094]

[0095] Figure 5 The on-axis chromatic aberration curve of the optical imaging device of Embodiment 1 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the optical imaging device. Figure 6 The astigmatism curves of the optical imaging device of Embodiment 1 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 7 The distortion curves of the optical imaging device of Embodiment 1 are shown, which represent the distortion magnitude values ​​corresponding to different field of view angles.

[0096] according to Figures 5 to 7 As can be seen, the optical imaging device given in Example 1 can achieve good imaging quality.

[0097] Example 2

[0098] like Figure 3 As shown, an optical imaging device according to Embodiment 2 of this application is described. The difference between Embodiment 1 and Embodiment 2 is that the distance and thickness between the various spacer elements, lenses, lens barrels P0, etc. are different.

[0099] Figure 3 A schematic diagram of the optical imaging device according to Embodiment 2 is shown. For the sake of brevity, descriptions similar to those in Embodiment 1 are omitted. In this embodiment, the rear end of the lens barrel is thinner, which is beneficial for the miniaturization and lightweight design of the optical imaging device.

[0100] Example 3

[0101] like Figure 4 As shown, an optical imaging device according to Embodiment 3 of this application is described. The difference between Embodiment 1 and Embodiment 3 is that the distance and thickness between the various spacer elements, lenses, lens barrels P0, etc. are different.

[0102] Figure 4 A schematic diagram of the optical imaging device according to Embodiment 3 is shown. For the sake of brevity, descriptions similar to those in Embodiment 1 are omitted. In this embodiment, the outer diameters of the object-side surface of the second spacer element and the third spacer element are moderately reduced, and the length of the image-side end of the lens tube is relatively short, which is beneficial for miniaturization of the optical imaging device.

[0103] Example 4

[0104] like Figure 8 As shown, an optical imaging device according to Embodiment 4 of this application is described. Figure 8 A schematic diagram of the optical imaging device of Embodiment 4 is shown.

[0105] like Figure 8 As shown, the optical imaging device includes, in sequence from the object side to the image side: a first lens E1, a first spacer element P1, a second lens E2, a second spacer element P2, a third lens E3, a third spacer element P3, a fourth lens E4, a fourth spacer element P4, a fifth lens E5, a fifth spacer element P5, a sixth lens E6, a sixth spacer element P6, a seventh lens E7, a seventh spacer element P7, and an eighth lens E8.

[0106] In this embodiment, the first lens E1 has negative optical power, its object-side surface S1 is concave, and its image-side surface S2 is convex. The second lens E2 has negative optical power, its object-side surface S3 is convex, and its image-side surface S4 is concave. The third lens E3 has positive optical power, its object-side surface S5 is convex, and its image-side surface S6 is convex. The fourth lens E4 has negative optical power, its object-side surface S7 is concave, and its image-side surface S8 is convex. The fifth lens E5 has positive optical power, its object-side surface S9 is convex, and its image-side surface S10 is concave. The sixth lens E6 has positive optical power, its object-side surface S11 is convex, and its image-side surface S12 is convex. The seventh lens E7 has positive optical power, its object-side surface S13 is convex, and its image-side surface S14 is concave. The eighth lens E8 has positive optical power, its object-side surface S15 is concave, and its image-side surface S16 is convex. The optical imaging device also includes a filter with an object-side surface S17 and an image-side surface S18. Light rays from the object pass through S1 to S18 to reach the imaging surface IMG. Table 4 shows the basic structural parameters of the optical imaging device in Embodiment 4, where the units for radius of curvature, thickness / distance, effective radius, and focal length are millimeters (mm).

[0107] Table 4

[0108] Face number Surface type radius of curvature thickness Refractive index Abbe number Effective radius Conic coefficient OBJ spherical endless endless S1 aspherical -1.9791 0.4625 1.61 61.10 1.8915 0.0000 S2 aspherical -2.2095 0.0571 1.6423 0.0000 S3 aspherical 2.9997 0.9813 1.67 19.20 1.5666 0.0000 S4 aspherical 1.5817 0.1306 0.9135 0.0000 S5 aspherical 2.1920 0.4885 1.54 56.00 0.8837 0.0000 S6 aspherical -5.4541 0.0801 0.7401 0.0000 STO spherical endless 0.1152 0.5256 0.0000 S7 aspherical -5.9871 0.4000 1.54 56.00 0.5985 0.0000 S8 aspherical -6.4248 0.0820 0.7052 0.0000 S9 aspherical 1.8398 0.4000 1.54 56.00 1.1312 0.0000 S10 aspherical 3.1017 0.1093 1.2638 0.0000 S11 aspherical 8.6763 0.4000 1.54 56.00 1.3077 0.0000 S12 aspherical -3.8242 0.0498 1.4968 0.0000 S13 aspherical 1.8354 0.4000 1.54 56.00 1.5665 0.0000 S14 aspherical 2.1646 0.3474 1.7233 0.0000 S15 aspherical -0.8443 0.4000 1.54 56.00 1.7601 -1.0000 S16 aspherical -0.7917 0.0665 1.9219 -1.0000 S17 spherical endless 0.2100 1.52 64.20 2.0401 0.0000 S18 spherical endless 0.2912 2.1001 0.0000 IMG spherical endless 0.0000 2.3008 0.0000

[0109] Table 5 shows the higher-order coefficients that can be used for each aspherical mirror in the embodiments, wherein the surface shape of each aspherical surface can be defined by formula (1) given in Embodiment 1 above. In this embodiment, the object-side surface and image-side surface of the first to eighth lenses are both aspherical.

[0110] Table 5

[0111] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 A22 S1 4.0172E-01 -4.2035E-01 4.0472E-01 -2.8246E-01 1.3513E-01 -4.3849E-02 9.3235E-03 -1.1732E-03 6.6254E-05 0.0000E+00 S2 5.6452E-01 -9.3177E-01 1.4351E+00 -1.4452E+00 9.2025E-01 -3.8064E-01 1.0136E-01 -1.5904E-02 1.0944E-03 7.1213E-06 S3 1.5919E-01 -8.9062E-01 2.4459E+00 -3.9065E+00 3.9686E+00 -2.6137E+00 1.0756E+00 -2.4994E-01 2.4934E-02 0.0000E+00 S4 -3.4399E-01 1.2596E+00 -1.1514E-01 -1.4466E+01 6.6852E+01 -1.5875E+02 2.0141E+02 -1.1777E+02 1.0381E+01 1.1643E+01 S5 -1.9677E-01 1.6890E+00 -5.2281E+00 5.4692E+00 2.7311E+01 -1.3946E+02 2.6928E+02 -2.4219E+02 8.4089E+01 0.0000E+00 S6 -1.7044E-02 1.2450E-02 -7.2236E-01 6.6304E+00 -4.3042E+01 1.6093E+02 -3.2772E+02 3.4107E+02 -1.4228E+02 0.0000E+00 S7 -1.6547E-01 -2.0270E+00 5.9460E+01 -9.6292E+02 8.8576E+03 -4.8539E+04 1.5661E+05 -2.7411E+05 2.0045E+05 0.0000E+00 S8 -5.8189E-01 1.4990E-01 8.0642E+00 -7.7741E+01 3.7449E+02 -1.0919E+03 1.9375E+03 -1.9177E+03 8.1133E+02 0.0000E+00 S9 -4.8101E-01 1.2023E+00 -2.5779E+00 3.6409E+00 -3.8250E+00 2.8338E+00 -1.0372E+00 -5.1221E-02 1.0464E-01 0.0000E+00 S10 2.3336E-01 -1.8680E+00 5.8273E+00 -1.0339E+01 1.1379E+01 -7.9609E+00 3.4448E+00 -8.3060E-01 7.8845E-02 2.4049E-03 S11 8.6927E-01 -3.1097E+00 6.3447E+00 -8.6407E+00 7.7117E+00 -4.3488E+00 1.4672E+00 -2.6376E-01 1.8215E-02 1.2835E-04 S12 1.0219E+00 -2.4944E+00 4.0783E+00 -4.5620E+00 3.4382E+00 -1.7115E+00 5.3792E-01 -9.6158E-02 7.2858E-03 4.1681E-05 S13 1.0231E-01 -1.3193E+00 2.2080E+00 -1.9206E+00 1.0149E+00 -3.3562E-01 6.6597E-02 -6.9484E-03 2.6068E-04 0.0000E+00 S14 4.2322E-01 -1.7163E+00 2.3125E+00 -1.6884E+00 7.2927E-01 -1.8620E-01 2.5835E-02 -1.4505E-03 -9.8751E-06 -1.1079E-07 S15 2.9876E+00 -7.6442E+00 1.0450E+01 -8.5731E+00 4.4693E+00 -1.4964E+00 3.1145E-01 -3.6459E-02 1.7777E-03 9.8189E-06 S16 3.2042E+00 -6.5048E+00 7.2697E+00 -5.0116E+00 2.2146E+00 -6.2728E-01 1.0967E-01 -1.0667E-02 4.2009E-04 3.0428E-06

[0112] Figure 11 The on-axis chromatic aberration curve of the optical imaging device of Embodiment 4 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the optical imaging device. Figure 12 The astigmatism curves of the optical imaging device of Embodiment 4 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 13 The distortion curves of the optical imaging device of Embodiment 4 are shown, which represent the distortion magnitude values ​​corresponding to different field of view angles.

[0113] according to Figures 11 to 13 It can be seen that the optical imaging device given in Example 4 can achieve good imaging quality.

[0114] Example 5

[0115] like Figure 9 As shown, an optical imaging device according to Embodiment 5 of this application is described. The difference between Embodiment 4 and Embodiment 5 is that the distance and thickness between the various spacer elements, lenses, lens barrels P0, etc. are different.

[0116] Figure 9 A schematic diagram of the optical imaging device according to Embodiment 5 is shown. For simplicity, descriptions similar to those in Embodiment 4 are omitted. In this embodiment, the third lens and the fourth lens are not interlocked; the object-side and image-side of the third spacer element directly contact the third lens and the fourth lens, respectively, improving the molding yield of the third lens and the fourth lens. Furthermore, the smaller wall thickness of the lens barrel facilitates miniaturization and weight reduction of the optical imaging device.

[0117] Example 6

[0118] like Figure 10 As shown, an optical imaging device according to Embodiment Six of this application is described. The difference between Embodiment Four and Embodiment Six is ​​that the distance and thickness between the various spacer elements, lenses, lens barrels P0, etc. are different.

[0119] Figure 10 A schematic diagram of the optical imaging device of Embodiment Six is ​​shown. For the sake of brevity, descriptions similar to those in Embodiment Four are omitted. In this embodiment, the overall thickness of the lens barrel is relatively small, which is beneficial for the miniaturization and weight reduction of the optical imaging device.

[0120] Example 7

[0121] like Figure 14 The optical imaging apparatus of Embodiment 7 of this application is described in the figure. Figure 14 A schematic diagram of the optical imaging device of Embodiment 7 is shown.

[0122] like Figure 14 As shown, the optical imaging device includes, in sequence from the object side to the image side: a first lens E1, a first spacer element P1, a second lens E2, a second spacer element P2, a third lens E3, a third spacer element P3, a fourth lens E4, a fourth spacer element P4, a fifth lens E5, a fifth spacer element P5, a sixth lens E6, a sixth spacer element P6, a seventh lens E7, a seventh spacer element P7, and an eighth lens E8.

[0123] In this embodiment, the first lens E1 has negative optical power, its object-side surface S1 is concave, and its image-side surface S2 is convex. The second lens E2 has negative optical power, its object-side surface S3 is convex, and its image-side surface S4 is concave. The third lens E3 has positive optical power, its object-side surface S5 is convex, and its image-side surface S6 is convex. The fourth lens E4 has negative optical power, its object-side surface S7 is concave, and its image-side surface S8 is convex. The fifth lens E5 has positive optical power, its object-side surface S9 is convex, and its image-side surface S10 is concave. The sixth lens E6 has positive optical power, its object-side surface S11 is convex, and its image-side surface S12 is concave. The seventh lens E7 has positive optical power, its object-side surface S13 is convex, and its image-side surface S14 is concave. The eighth lens E8 has positive optical power, its object-side surface S15 is concave, and its image-side surface S16 is convex. The optical imaging device also includes a filter with an object-side surface S17 and an image-side surface S18. Light rays from the object pass through S1 to S18 to reach the imaging surface IMG. Table 6 shows the basic structural parameters of the optical imaging device of Embodiment Seven, where the units for radius of curvature, thickness / distance, effective radius, and focal length are millimeters (mm).

[0124] Table 6

[0125]

[0126]

[0127] Table 7 shows the higher-order coefficients that can be used for each aspherical mirror in the embodiments, wherein the surface shape of each aspherical surface can be defined by formula (1) given in Embodiment 1 above. In this embodiment, the object-side surface and image-side surface of the first to eighth lenses are both aspherical.

[0128] Table 7

[0129] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 A22 S1 5.7586E-01 -8.3865E-01 9.1408E-01 -6.6976E-01 3.2534E-01 -1.0406E-01 2.1100E-02 -2.4580E-03 1.2531E-04 0.0000E+00 S2 1.1828E+00 -3.1446E+00 5.7897E+00 -6.7936E+00 5.1989E+00 -2.6153E+00 8.3593E-01 -1.5288E-01 1.1658E-02 1.4947E-04 S3 5.4388E-01 -2.7245E+00 7.1825E+00 -1.1524E+01 1.1985E+01 -8.1861E+00 3.5501E+00 -8.8526E-01 9.6444E-02 0.0000E+00 S4 -1.0121E-01 1.5238E-01 4.9419E+00 -2.6014E+01 6.9848E+01 -1.2213E+02 1.2960E+02 -6.2170E+01 -5.3702E+00 1.1352E+01 S5 2.0164E-02 2.1203E-01 5.3229E+00 -4.2981E+01 1.6127E+02 -3.6559E+02 4.9848E+02 -3.7072E+02 1.1484E+02 0.0000E+00 S6 6.6586E-03 -3.4473E-01 2.2838E+00 -1.2221E+01 4.2215E+01 -9.3751E+01 1.3298E+02 -1.1083E+02 4.1327E+01 0.0000E+00 S7 -2.2960E-01 1.0353E+00 -2.0881E+01 1.7796E+02 -7.0847E+02 8.0587E+01 9.5824E+03 -3.1028E+04 3.1414E+04 0.0000E+00 S8 -5.8796E-01 -5.3457E-01 1.8593E+01 -1.6232E+02 7.7100E+02 -2.2389E+03 3.9546E+03 -3.8997E+03 1.6488E+03 0.0000E+00 S9 -5.3643E-01 1.0924E+00 -9.6826E-01 -2.8705E+00 1.1014E+01 -1.8169E+01 1.6863E+01 -8.3542E+00 1.7047E+00 0.0000E+00 S10 4.0146E-01 -2.6896E+00 7.0682E+00 -1.0653E+01 1.0151E+01 -6.3173E+00 2.5241E+00 -5.9086E-01 5.9901E-02 8.0160E-04 S11 1.2268E+00 -4.2972E+00 9.4705E+00 -1.5014E+01 1.6324E+01 -1.1615E+01 5.1394E+00 -1.2778E+00 1.3411E-01 8.2199E-04 S12 -1.3297E-02 1.1527E+00 -2.9461E+00 3.7188E+00 -2.8450E+00 1.3773E+00 -4.1240E-01 6.9369E-02 -4.8768E-03 -3.3608E-05 S13 -6.7455E-01 8.3206E-01 -2.0097E+00 3.2611E+00 -2.9581E+00 1.5731E+00 -4.9242E-01 8.4348E-02 -6.1129E-03 0.0000E+00 S14 1.0146E+00 -3.2507E+00 4.6304E+00 -4.0203E+00 2.2803E+00 -8.4688E-01 1.9729E-01 -2.5995E-02 1.4705E-03 8.2461E-08 S15 3.6449E+00 -8.9247E+00 1.2510E+01 -1.0969E+01 6.2260E+00 -2.2799E+00 5.1626E-01 -6.4767E-02 3.2190E-03 3.9860E-05 S16 3.4369E+00 -7.0029E+00 8.0369E+00 -5.7115E+00 2.6003E+00 -7.5791E-01 1.3620E-01 -1.3617E-02 5.5695E-04 3.2137E-06

[0130] Figure 17 The on-axis chromatic aberration curve of the optical imaging device of Embodiment 7 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the optical imaging device. Figure 18 The astigmatism curves of the optical imaging device of Embodiment 7 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 19 The distortion curves of the optical imaging device of Embodiment 7 are shown, which represent the distortion magnitude values ​​corresponding to different field of view angles.

[0131] according to Figures 17 to 19 It can be seen that the optical imaging device given in Embodiment 7 can achieve good imaging quality.

[0132] Example 8

[0133] like Figure 15 As shown, an optical imaging device according to Embodiment 8 of this application is described. The difference between Embodiment 7 and Embodiment 8 is that the distance and thickness between the various spacer elements, lenses, lens barrels, etc. are different.

[0134] Figure 15 A schematic diagram of the optical imaging device of Embodiment 8 is shown. For the sake of brevity, descriptions similar to those in Embodiment 7 are omitted. In this embodiment, the aperture at the image-side end of the lens tube is smaller, which is beneficial for miniaturization of the optical imaging device.

[0135] Example 9

[0136] like Figure 16 As shown, an optical imaging device according to Embodiment Nine of this application is described. The difference between Embodiment Seven and Embodiment Nine is that the distance and thickness between the various spacer elements, lenses, lens barrels P0, etc. are different.

[0137] Figure 16 A schematic diagram of the optical imaging device of Embodiment Nine is shown. For the sake of brevity, descriptions similar to those in Embodiment Seven are omitted. In this embodiment, the apertures of both the object-side and image-side ends of the lens tube are relatively small, further achieving miniaturization and weight reduction of the optical imaging device.

[0138] In summary, Embodiments 1 to 9 of the optical imaging device respectively satisfy the relationships shown in Table 8.

[0139] Table 8

[0140] Conditional / Example 1 2 3 4 5 6 7 8 9 FNO×TAN(Semi-FOV) 4.16 4.16 4.16 4.30 4.30 4.30 3.29 3.29 3.29 R1 / R2 1.30 1.30 1.30 0.90 0.90 0.90 0.89 0.89 0.89 d0s / R1 -0.81 -0.78 -0.78 -0.70 -0.89 -0.88 -0.76 -0.76 -0.69 d1s / R2 -0.64 -0.64 -0.63 -0.52 -0.53 -0.52 -0.54 -0.55 -0.55 (d0s-d1s) / CT1 2.10 1.90 1.95 0.52 1.31 1.25 0.60 0.56 0.30 (R1-R2) / EP01 -0.69 -0.69 -0.70 0.27 0.21 0.21 0.25 0.25 0.25 (DT11-d0s) / EPD 1.08 1.14 1.14 2.16 1.83 1.86 2.17 2.18 2.29 (D1s-d1s) / DT12 0.52 0.46 0.37 0.54 0.48 0.46 0.58 0.47 0.50 CT2 / (CT1+CT3) 0.92 0.92 0.92 1.03 1.03 1.03 0.93 0.93 0.93 (d1m-d2s) / CT2 0.16 0.16 0.16 0.08 0.08 0.09 0.08 0.06 0.03 f2 / (D2s-D1m) -9.66 -8.08 -8.08 -14.41 -11.97 -11.45 -14.97 -14.97 -14.97 d2s / R4 0.84 0.85 0.83 0.68 0.68 0.68 0.63 0.64 0.66 d2m / R5 0.52 0.53 0.52 0.49 0.49 0.49 0.43 0.44 0.46 EP12 / f2 -0.18 -0.18 -0.18 -0.16 -0.16 -0.16 -0.13 -0.13 -0.13 EP23 / f3 0.16 0.16 0.16 0.17 0.17 0.17 0.14 0.14 0.14 (D3s-d3s) / DT32 1.77 1.72 1.52 0.83 1.67 1.65 2.23 1.97 2.02 d3s / f3 0.38 0.38 0.38 0.36 0.36 0.37 0.32 0.31 0.32 L / TD 1.58 1.54 1.45 1.42 1.42 1.42 1.35 1.35 1.35 CT3 / f3 0.17 0.17 0.17 0.17 0.17 0.17 0.13 0.13 0.13

[0141] Table 9 shows the effective focal lengths f1 to f8 of each lens in the optical imaging devices of Examples 1 to 9, in mm.

[0142] Table 9

[0143] Parameters / Examples 1 2 3 4 5 6 7 8 9 f 2.499 2.499 2.499 2.202 2.202 2.202 1.926 1.926 1.926 FNO 1.995 1.995 1.995 1.995 1.995 1.995 1.900 1.900 1.900 EPD 1.253 1.253 1.253 1.104 1.104 1.104 1.014 1.014 1.014 Semi-FOV 64.390 64.390 64.390 65.120 65.120 65.120 60.020 60.020 60.020 f1 12.853 12.853 12.853 -129.725 -129.725 -129.725 -102.963 -102.963 -102.963 f2 -4.929 -4.929 -4.929 -6.857 -6.857 -6.857 -7.125 -7.125 -7.125 f3 2.914 2.914 2.914 2.931 2.931 2.931 3.099 3.099 3.099 f4 80.853 80.853 80.853 -237.742 -237.742 -237.742 -30.932 -30.932 -30.932 f5 9.459 9.459 9.459 7.452 7.452 7.452 6.307 6.307 6.307 f6 4.627 4.627 4.627 4.919 4.919 4.919 85.441 85.441 85.441 f7 -19.008 -19.008 -19.008 15.473 15.473 15.473 2.473 2.473 2.473 f8 2176.105 2176.105 2176.105 6.320 6.320 6.320 7.128 7.128 7.128

[0144] Table 10 shows some structural parameters of the optical imaging devices in Examples 1 to 9, in mm.

[0145] Table 10

[0146] Parameters / Examples 1 2 3 4 5 6 7 8 9 d1s 1.280 1.290 1.270 1.153 1.161 1.156 1.062 1.068 1.075 d1m 1.280 1.290 1.270 1.153 1.161 1.156 1.062 1.068 1.075 D1s 2.930 2.760 2.460 2.929 2.732 2.676 2.929 2.596 2.696 D1m 2.930 2.760 2.460 2.929 2.732 2.676 2.929 2.596 2.696 d2s 1.150 1.160 1.140 1.073 1.078 1.068 1.000 1.020 1.050 d2m 1.150 1.160 1.140 1.073 1.078 1.068 1.000 1.020 1.050 D2s 3.440 3.370 3.070 3.405 3.305 3.275 3.405 3.072 3.172 d3s 1.110 1.120 1.100 1.056 1.060 1.070 0.985 0.965 1.002 D3s 3.700 3.630 3.330 2.279 3.536 3.506 3.636 3.303 3.403 d0s 2.120 2.050 2.050 1.395 1.766 1.736 1.324 1.316 1.207 EP01 0.880 0.880 0.870 0.864 1.089 1.087 0.864 0.864 0.864 EP12 0.900 0.900 0.910 1.114 1.114 1.102 0.931 0.931 0.931 EP23 0.460 0.460 0.460 0.510 0.510 0.502 0.422 0.422 0.440 L 7.040 6.860 6.450 6.957 6.952 6.952 6.096 6.096 6.096

[0147] Obviously, the embodiments described above are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0148] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0149] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0150] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An optical imaging device, characterized in that, The optical imaging device has eight lenses with optical power, and the optical imaging device includes: The lens group, from the object side to the image side of the optical imaging device, includes a first lens to an eighth lens arranged in sequence at intervals, wherein the object side of the first lens is concave and the image side of the first lens is convex. A group of spacers, the group of spacers including at least a first spacer located between the first lens and the second lens and in at least partial contact with the image side of the first lens, a second spacer located between the second lens and the third lens and in at least partial contact with the image side of the second lens, and a third spacer located between the third lens and the fourth lens and in at least partial contact with the image side of the third lens; The lens barrel, the lens group and the spacer element group are housed within the lens barrel, and the inner ring surface of the lens barrel is stepped along the direction of the optical axis of the optical imaging device; Wherein, the Semi-FOV (half of the maximum field of view) of the optical imaging device and the numerical aperture (FNO) of the optical imaging device satisfy the following condition: 3.25 <FNO×TAN(Semi-FOV)≤4.3; The radius of curvature R1 of the object-side surface of the first lens and the radius of curvature R2 of the image-side surface of the first lens are both negative, and the relationship between the radius of curvature R1 of the object-side surface and the radius of curvature R2 of the image-side surface of the first lens satisfies: 0.85 <R1 / R2≤1.3; The inner diameter d0s of the object-side end face of the lens barrel and the radius of curvature R1 of the object-side surface of the first lens satisfy the following relationship: -0.9 <d0s / R1<-0.6; The inner diameter d1s of the object-side surface of the first spacer element and the radius of curvature R2 of the image-side surface of the first lens satisfy the following relationship: -0.7 <d1s / R2<-0.6。 2. The optical imaging device according to claim 1, characterized in that, The inner diameter d0s of the object-side end face of the lens barrel, the inner diameter d1s of the object-side side face of the first spacer element, and the center thickness CT1 of the first lens on the optical axis satisfy the following condition: 0.3≤(d0s-d1s) / CT1<2.

5.

3. The optical imaging device according to claim 1, characterized in that, The distance EP01 from the object-side end face of the lens barrel to the object-side surface of the first spacer element along the optical axis, the radius of curvature R1 of the object-side surface of the first lens, and the radius of curvature R2 of the image-side surface of the first lens satisfy the following condition: -0.7≤(R1-R2) / EP01<0.

3.

4. The optical imaging device according to claim 1, characterized in that, The effective diameter DT11 of the object side of the first lens, the inner diameter d0s of the object side end face of the lens barrel, and the entrance pupil diameter EPD of the optical imaging device satisfy the following condition: 1.05 < (DT11 - d0s) / EPD < 2.

3.

5. The optical imaging device according to claim 1, characterized in that, The inner diameter d1s of the object side of the first spacer element, the outer diameter D1s of the object side of the first spacer element, and the effective diameter DT12 of the image side of the first lens satisfy the following condition: 0.35 < (D1s - d1s) / DT12 < 0.

6.

6. The optical imaging device according to claim 1, characterized in that, The central thickness CT2 of the second lens on the optical axis is the largest among the lenses of the optical imaging device, and the central thickness CT1 of the first lens on the optical axis, the central thickness CT2 of the second lens on the optical axis, and the central thickness CT3 of the third lens on the optical axis satisfy: 0.9 < CT2 / (CT1 + CT3) < 1.

05.

7. The optical imaging device according to claim 1, characterized in that, The inner diameter d2s of the object side surface of the second spacer element, the inner diameter d1m of the image side surface of the first spacer element, and the central thickness CT2 of the second lens on the optical axis satisfy: 0 < (d1m - d2s) / CT2 < 0.

2.

8. The optical imaging device according to claim 1, characterized in that, The outer diameter D1m of the image side surface of the first spacer element, the outer diameter D2s of the object side surface of the second spacer element, and the effective focal length f2 of the second lens satisfy: -15 < f2 / (D2s - D1m) < -8.

9. The optical imaging device according to claim 1, characterized in that, The inner diameter d2s of the object side surface of the second spacer element and the radius of curvature R4 of the image side surface of the second lens satisfy: 0.6 < d2s / R4 < 0.9; the inner diameter d2m of the image side surface of the second spacer element and the radius of curvature R5 of the object side surface of the third lens satisfy: 0.4 < d2m / R5 < 0.

6.

10. The optical imaging device according to claim 1, characterized in that, The distance EP12 from the image side surface of the first spacer element to the object side surface of the second spacer element along the optical axis direction and the effective focal length f2 of the second lens satisfy: -0.2 < EP12 / f2 < -0.10; the distance EP23 from the image side surface of the second spacer element to the object side surface of the third spacer element along the optical axis direction and the effective focal length f3 of the third lens satisfy: 0.1 < EP23 / f3 < 0.

2.

11. The optical imaging apparatus according to any one of claims 1 to 10, characterized in that, The inner diameter d3s of the object side surface of the third spacer element, the outer diameter D3s of the object side surface of the third spacer element, and the effective diameter DT32 of the image side surface of the third lens satisfy: 0.8 < (D3s - d3s) / DT32 < 2.

3.

12. The optical imaging apparatus according to any one of claims 1 to 10, characterized in that, The inner diameter d3s of the object side surface of the third spacer element and the effective focal length f3 of the third lens satisfy: 0.3 < d3s / f3 < 0.

4.

13. The optical imaging apparatus according to any one of claims 1 to 10, characterized in that, The distance L from the object side end face of the lens barrel to the image side end face of the lens barrel along the optical axis direction and the on-axis distance TD from the object side surface of the first lens to the image side surface of the eighth lens satisfy: 1.35 ≤ L / TD < 1.6.

Images