Optical imaging device

Abstract

The invention 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] The present invention relates to the technical field of optical imaging equipment, and in particular to an optical imaging device. Background Art

[0002] In the current technical field, optical imaging devices play a vital role in application scenarios such as wearable devices. The front-end lens of an ultra-wide-angle, large-aperture optical imaging device controls the imaging quality of the entire optical imaging device, directly affecting the initial refraction of light and the subsequent focusing path. Reasonable setting of the optical parameters of the front-end lens can capture a wider field of view and provide better imaging performance in dark environments, and is widely favored. However, when the radii of curvature of the object side and the image side of the front-end lens are similar, the front-end lens is prone to optical problems such as insufficient light refraction, decreased focusing ability, and reduced MTF (modulation transfer function). Therefore, how to control the shape of the front-end lens, lens barrel, and spacer elements of an ultra-wide-angle, large-aperture optical imaging device, adjust the distribution of the front-end light, and improve the imaging quality is a very important issue. Summary of the invention

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

[0004] To achieve the above object, according to one aspect of the present invention, 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 in contact with 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 in contact with 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 in contact with the image side surface of the third lens; a barrel, the lens group and the spacer element group are accommodated in the barrel. Along the direction of the optical axis of the optical imaging device, the inner ring surface of the barrel is stepped; wherein, half of the maximum field of view 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 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 surface of the 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.

[0005] According to another aspect of the present invention, 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 in contact with 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 in contact with 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 in contact with the image side surface of the third lens; a barrel, the lens group and the spacer element group are accommodated in the barrel. Along the direction of the optical axis of the optical imaging device, the inner ring surface of the barrel is stepped; wherein, half of the maximum field of view 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.

[0006] Furthermore, the following relationship is satisfied among 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 central thickness CT1 of the first lens on the optical axis: 0.3 ≤ (d0s - d1s) / CT1 < 2.5.

[0007] Furthermore, the following relationship is satisfied among 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 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: -0.7 ≤ (R1 - R2) / EP01 < 0.3.

[0008] Furthermore, the following relationship is satisfied among 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: 1.05 < (DT11 - d0s) / EPD < 2.3.

[0009] Furthermore, 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.

[0010] Furthermore, 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 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.

[0011] Furthermore, the following relationship is satisfied among 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: 0 < (d1m - d2s) / CT2 < 0.2.

[0012] Furthermore, the following relationship is satisfied among 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: -15 < f2 / (D2s - D1m) < -8.

[0013] Furthermore, the following relationship is satisfied between the inner diameter d2s of the object-side surface of the second spacer element and the curvature radius R4 of the image-side surface of the second lens: 0.6 < d2s / R4 < 0.9; and the following relationship is satisfied between the inner diameter d2m of the image-side surface of the second spacer element and the curvature radius R5 of the object-side surface of the third lens: 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 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 in the optical axis direction 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 in contact with 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 in contact with 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 in contact with the image side surface of the third lens; the lens group and the spacer element group are accommodated in the lens barrel. 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 of view 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 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 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 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 ability 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 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 light passing through the object side and 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 specification drawings forming a part of the present 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 of the present invention. In the drawings:

[0020] Figure 1 A partial parameter schematic diagram of the optical imaging device of any optional embodiment of the present invention is shown;

[0021] Figure 2 A structural schematic diagram of the optical imaging device of Embodiment 1 of the present invention is shown;

[0022] Figure 3 A structural schematic diagram of the optical imaging device of Embodiment 2 of the present invention is shown;

[0023] Figure 4 A structural schematic diagram of the optical imaging device of Embodiment 3 of the present invention is shown;

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

[0025] Figure 8 A schematic structural diagram of an optical imaging device according to a fourth embodiment of the present invention is shown;

[0026] Fig. 9 A schematic structural diagram of an optical imaging device according to a fifth embodiment of the present invention is shown;

[0027] Fig.10 A schematic structural diagram of an optical imaging device according to a sixth embodiment of the present invention is shown;

[0028] Figures 11 to 13 The axial chromatic aberration curve, astigmatism curve, and distortion curve of the optical imaging device of the fourth embodiment are respectively shown;

[0029] Fig.14 A schematic structural diagram of an optical imaging device according to a seventh embodiment of the present invention is shown;

[0030] Fig.15 A schematic structural diagram of an optical imaging device according to an eighth embodiment of the present invention is shown;

[0031] Fig.16 A schematic structural diagram of an optical imaging device according to a ninth embodiment of the present invention is shown;

[0032] Figures 17 to 19 The axial chromatic aberration curve, astigmatism curve, and distortion curve of the optical imaging device of Example 7 are respectively shown;

[0033] Fig. 20 An MTF curve of an 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, d1s / R2=-0.64;

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

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

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

[0037] P0, lens barrel; E1, first lens; P1, first spacing element; E2, second lens; P2, second spacing element; E3, third lens; P3, third spacing element; E4, fourth lens; P4, fourth spacing element; E5, fifth lens; P5, fifth spacing element; E6, sixth lens; P6, sixth spacing element; E7, seventh lens; P7, seventh spacing element; E8, eighth lens; S1, object side surface of first lens; S2, image side surface of first lens; S3, second The object side surface of the first lens; S4, the image 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 DESCRIPTION

[0038] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0039] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0040] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0041] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0042] In the 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 shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are for illustration 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 (the R value refers to the radius of curvature in the paraxial region, usually the R value on the lens database in optical software). Taking the eye side surface as an example, when the R value is positive, it is judged as convex, and when the R value is negative, it is judged as concave; taking the display side surface as an example, 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 of poor imaging effect caused by unreasonable front-end light distribution in the prior art in an ultra-wide-angle and large-aperture optical imaging device, the present invention 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 in contact with 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 in contact with 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 in contact with 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 of view 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 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 face 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 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 ability of the light in the meridian 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. 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 for different details.

[0049] Table 1

[0050] Program No. Solution 1 Solution 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 Attached Fig. 20 Attached Fig.21 Attached Fig. 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 Fig.21As shown in the figure, 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 face of the first spacing element is too large, a large amount of light enters the optical imaging device, and the MTF curve drops significantly. For scheme 3, FNO×TAN(Semi-FOV)=4.16, R1 / R2=1.30, d0s / R1=-1.24, d1s / R2=-0.24, as shown in the figure. Fig. 22 As shown, 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 face of the first spacing element is too small, the light trend is steep, and the MTF curve drops significantly.

[0052] The optical imaging device shown in Scheme 1 belongs to an embodiment of the present application. Scheme 1 has FNO×TAN(Semi-FOV)=4.16, R1 / R2=1.30, d0s / R1=-0.81, d1s / R2=-0.64. Fig. 20 As shown, at this time, 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 face of the first spacing 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 face of the first spacing element, and the center thickness CT1 of the first lens on the optical axis satisfy the following relationship: 0.3≤(d0s-d1s) / CT1<2.5. If the value of (d0s-d1s) / CT1 is too large, the path angle of the light becomes too steep when entering the lens barrel and passing through the first spacing element, which will cause a large amount of scattering of the edge light, thereby reducing the MTF value and affecting the clarity of the image. If the value of (d0s-d1s) / CT1 is too small, the light path is too flat, resulting in insufficient reflection or refraction of the light between the lenses, which also causes astigmatism and reduces the 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 face of the first spacing element, and the center thickness of the first lens on the optical axis can be constrained, which helps to intercept excess light entering the optical imaging device through the object side end face of the lens barrel and the first spacing element, avoids the generation of stray light in the lens structure area of ​​the optical imaging device, and effectively controls the brightness of the edge field of view, so that clear imaging can still be obtained in a dark environment, ensuring imaging quality. In addition, the center thickness of the first lens can better control the air gap between the first lens and the second lens, which can effectively reduce imaging distortion.

[0054] In this embodiment, the distance EP01 from the object side end face of the lens barrel to the object side face of the first spacing element along the direction of the optical axis, the radius of curvature R1 of the object side face of the first lens, and the radius of curvature R2 of the image side face of the first lens satisfy: -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 face of the first lens and the image side face of the first lens is too large, resulting in inaccurate focusing of the light inside the lens barrel, causing spherical aberration and other aberrations, thereby affecting the imaging quality. If the value of (R1-R2) / EP01 is too small, the first lens has insufficient refractive power for light, the light path inside the lens barrel is poor, and aberrations are caused. By limiting (R1-R2) / EP01 within a reasonable range, the distance from the object side end face of the lens barrel to the object side face of the first spacing element along the optical axis, the relationship between the radius of curvature of the object side face of the first lens and the radius of curvature of the image side face of the first lens can be constrained, which helps to prevent the lens center of the object side face of the first lens from protruding from the object side end face of the lens barrel, and prevents the object side face of the first lens from being scratched and reduced in the process of assembly, transportation, and use. On this basis, controlling the radius of curvature of the object side face of the first lens and the radius of curvature of the image side face of the first lens helps to effectively focus the light, effectively control the generation of spherical aberration, and improve the clarity of the image.

[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 surface 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 an increase in stray light in the non-imaging area, affecting the brightness and clarity 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, affecting the brightness of the imaging. By limiting (DT11-d0s) / EPD within 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 surface 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 an 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 surface of the lens barrel can effectively reduce the risk of aberrations of 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 abutment stability between the first spacer element and the first lens. In addition, it is easy to cause light to be blocked 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 abutment stability while avoiding too small an inner diameter of the first spacer element, resulting in the interception of effective imaging light at the edge of the first spacer element, causing incomplete imaging or vignetting at the edge.

[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 to be blocked 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 high imaging quality.

[0058] In the present 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 the present 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 and constraining 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, it 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 high-definition and high-contrast imaging effects.

[0061] In this embodiment, the inner diameter d2m of the image side surface of the second spacer element and the curvature radius 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, the smooth transition of light from the second lens to the third lens is restricted, 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 that the transition of light between the second spacer element and the third lens is gentle, 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 this 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, the focusing position of light on the second lens deviates 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 this 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 optical axis direction 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 rays 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 rays on the third lens becomes too compact, increasing astigmatism and other aberrations and affecting the imaging effect of the peripheral field of view. By restricting EP23 / f3 within a reasonable range, it is possible to ensure a smooth transition of the light rays between the second spacer element and the third lens, and the light rays enter the third lens with the best 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 this 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, which not only increases the front port diameter of the optical imaging device but also easily causes 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 contact 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 this 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 and affecting the imaging clarity and brightness. If the value of d3s / f3 is too small, the third spacer element intercepts too much light, which also affects 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 rays emitted by the third lens are 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 the present 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 direction of the optical axis, and the on-axis distance TD from the object side face of the first lens to the image side face of the eighth lens satisfy: 1.35≤L / TD<1.6. If the value of L / TD is too large, the protruding parts of the object side end and the image side end of the lens barrel are too many, which are easily damaged during assembly, transportation or use, and the risk of generating stray light at the object side end and the image side end of the lens barrel is high, affecting the imaging quality. If the value of L / TD is too small, the length of the lens barrel is not enough to effectively protect the lens group. By limiting L / TD within a reasonable range, by constraining the distance from the object side end face of the lens barrel to the image side end face of the lens barrel along the direction of the optical axis, and the on-axis distance from the object side face of the first lens to the image side face of the eighth lens, it is helpful to reduce the risk of the shape of the object side face of the first lens and the image side face of the eighth lens protruding from the lens barrel, and avoid the front lens and the rear lens from interfering with the assembly mold, resulting in the risk of reduced reliability and imaging quality.

[0065] In this embodiment, the object side surface of the first lens is concave, 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 the optical imaging device, the arrangement and surface shape of the lens group can optimize the trend and focusing effect of light to achieve high-quality imaging performance. Specifically, the object side surface of the first lens is a concave surface, so that the light is first diverged when entering the initial stage of the optical imaging device, thereby appropriately diffusing the incident angle of the light. The image side surface of the first lens is a convex surface, which helps to perform preliminary focusing after the light enters the optical imaging device. The second lens has a negative optical focal length, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface, which can further diverge the light, control the light path, reduce aberrations, and help reduce the spherical aberration and coma caused by the initial focusing of the first lens, ensuring that the light smoothly transitions to the third lens. The third lens has a positive optical focal length, the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a convex surface, which enables the light to be refocused by the third lens after being diverged by the second lens, further improving the convergence effect of the light, helping to control the focusing of oblique incident light, and improving the imaging quality of the meridian and sagittal planes. The object side surface of the fourth lens is concave, and the image side surface of the fourth lens is convex, so that the light can be quickly focused after it diverges again after reaching the third lens, reducing astigmatism and other high-order aberrations. 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, which can focus the light again, control the convergence point of the light, and further reduce spherical aberration and coma. The sixth lens also has positive optical power, and the object side surface of the sixth lens is convex, which helps to fine-tune the light after passing through the fifth lens, improve the light gathering efficiency, reduce the divergence of the light when focusing at the end, and thus improve the clarity and details of the image. The object side surface of the seventh lens is convex, and the image side surface of the seventh lens is concave, which can make the last focusing adjustment of the light before the light reaches the imaging surface, reduce the divergence of the light at the rear end, ensure that the light forms a clear and sharp image on the imaging surface, and improve the contrast and resolution of the imaging. Finally, the eighth lens has positive focal power, the object side surface of the eighth lens is concave, and the image side surface of the eighth lens is convex, which diverges the light to avoid it being too concentrated and producing an overly sharp focusing effect. It is focused through the convex surface of the image side surface of the eighth lens to ensure that the light is smoothly and accurately converged 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 embodiment of the present application can be simulated by software and / or tools such as ZEMAX, CODEV, etc. Optionally, the optical imaging device can be simulated by CODEV software. In the process of simulation using the above software and / or tools, the surface shape of each lens can be appropriately adjusted according to the surface shape of the software and / or tool 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 circumferential surface of the trimmed spacer element has a trimmed portion and an untrimmed portion, and the outer diameter of the trimmed portion is smaller than that of the untrimmed portion. The outer diameter of the trimmed spacer element generally refers to the maximum outer diameter of the untrimmed portion.

[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; at least the first spacer element located between the first lens and the second lens and at least partially in contact with the image side surface of the first lens, the second spacer element located between the second lens and the third lens and at least partially in contact with the image side surface of the second lens, and the third spacer element located between the third lens and the fourth lens and at least partially in contact with the image side surface of the third lens are included in the spacer element group; 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 circumferential surface of the lens barrel is stepped; wherein, half of the maximum field of view 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 of view 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, while optimizing the focusing effect of the third lens on light, reducing the aberration caused by the mismatch between the lens thickness and the focal length, and improving the imaging quality of the optical imaging device.

[0073] It should be noted that this embodiment also includes other conditional expressions in the above embodiment, which will not be described one by one here.

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

[0075] The optical imaging device in the present application may use multiple lenses, such as the eight lenses mentioned above. In the present application, at least one of the mirror surfaces of each lens is an aspherical mirror surface. The characteristics of an aspherical lens are: the curvature changes continuously from the center of the lens to the periphery of the lens. Unlike a spherical lens with a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has a better curvature radius characteristic, and has the advantages of improving distortion aberration and improving astigmatism aberration. After using an aspherical lens, the aberration that occurs during imaging can be eliminated as much as possible, thereby improving the imaging quality.

[0076] It should be noted that, in the optical imaging device in the present application, the spacer element in the spacer element group that is located on the image side of the i-th lens and at least partially in contact with the image side surface 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 should understand that, without departing from the technical solution claimed in the present application, the number of lenses constituting the optical imaging device can be changed to obtain the various results and advantages described in this specification. For example, although eight lenses are 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 of dimension marking of an optical imaging device of the present application is shown. Figure 1 Parameters such as d1s, D2s, L, and EP23 are marked in the figure to clearly and intuitively understand the meaning of the parameters. In order to facilitate the description of the optical imaging device and the surface shape of the specific lens, these parameters will no longer be reflected in the drawings when describing the specific embodiments later.

[0079] The following further describes examples of specific surface shapes and parameters of the optical imaging device applicable to the above-mentioned embodiments with reference to the accompanying drawings.

[0080] It should be noted that any one of the following embodiments 1 to 9 is applicable to all embodiments of the present application.

[0081] Embodiment 1

[0082] like Figure 2 As shown, the optical imaging device of the first embodiment of the present application is described. Figure 2 A schematic structural diagram of the optical imaging device of the first embodiment is shown.

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

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

[0085] Table 2 shows the basic structural parameters of the optical imaging device of Example 1, wherein the units of the curvature radius, 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 the image side surface of any lens from the first lens E1 to the eighth lens E8 are both aspherical surfaces, and the surface shape of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0090]

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

[0092] Table 3

[0093]

[0094]

[0095] Figure 5 The axial chromatic aberration curve of the optical imaging device of the first embodiment is shown, which indicates the deviation of the focusing point of light of different wavelengths after passing through the optical imaging device. Figure 6 The astigmatism curve of the optical imaging device of the first embodiment is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 7 The distortion curve of the optical imaging device of the first embodiment is shown, which indicates the distortion magnitude values ​​corresponding to different field of view angles.

[0096] according to Figures 5 to 7 It can be seen that the optical imaging device provided in the first embodiment can achieve good imaging quality.

[0097] Embodiment 2

[0098] like Figure 3 As shown, an optical imaging device according to the second embodiment of the present application is described, which differs from the first embodiment in that the distances and thicknesses between the spacer elements, lenses, lens barrel P0, etc. are different.

[0099] Figure 3 The structure diagram of the optical imaging device of the second embodiment is shown. For the sake of brevity, some descriptions similar to those of the first embodiment are omitted. In this embodiment, the thickness of the rear end of the lens barrel is relatively thin, which is conducive to the miniaturization and lightweight design of the optical imaging device.

[0100] Embodiment 3

[0101] like Figure 4 As shown, the optical imaging device of the third embodiment of the present application is described, which differs from the first embodiment in that the distances and thicknesses between the various spacing elements, lenses, lens barrel P0, etc. are different.

[0102] Figure 4 The schematic diagram of the structure of the optical imaging device of the third embodiment is shown. For the sake of brevity, some descriptions similar to those of the first embodiment are omitted. In this embodiment, the outer diameter of the object side surface of the second spacing element and the outer diameter of the object side surface of the third spacing element are moderately reduced, and the length of the image side end of the lens barrel is relatively short, which is conducive to the miniaturization of the optical imaging device.

[0103] Embodiment 4

[0104] like Figure 8 As shown, the optical imaging device of the fourth embodiment of the present application is described. Figure 8 A schematic structural diagram of an optical imaging device according to a fourth embodiment is shown.

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

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

[0107] Table 4

[0108] Face number Surface type Radius of curvature thickness Refractive Index Abbe number Effective radius Cone coefficient OBJ Spherical endless endless S1 Aspheric -1.9791 0.4625 1.61 61.10 1.8915 0.0000 S2 Aspheric -2.2095 0.0571 1.6423 0.0000 S3 Aspheric 2.9997 0.9813 1.67 19.20 1.5666 0.0000 S4 Aspheric 1.5817 0.1306 0.9135 0.0000 S5 Aspheric 2.1920 0.4885 1.54 56.00 0.8837 0.0000 S6 Aspheric -5.4541 0.0801 0.7401 0.0000 STO Spherical endless 0.1152 0.5256 0.0000 S7 Aspheric -5.9871 0.4000 1.54 56.00 0.5985 0.0000 S8 Aspheric -6.4248 0.0820 0.7052 0.0000 S9 Aspheric 1.8398 0.4000 1.54 56.00 1.1312 0.0000 S10 Aspheric 3.1017 0.1093 1.2638 0.0000 S11 Aspheric 8.6763 0.4000 1.54 56.00 1.3077 0.0000 S12 Aspheric -3.8242 0.0498 1.4968 0.0000 S13 Aspheric 1.8354 0.4000 1.54 56.00 1.5665 0.0000 S14 Aspheric 2.1646 0.3474 1.7233 0.0000 S15 Aspheric -0.8443 0.4000 1.54 56.00 1.7601 -1.0000 S16 Aspheric -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 high-order coefficients that can be used for each aspherical mirror surface in the embodiment, wherein the surface shape of each aspherical surface can be defined by the formula (1) given in the above embodiment 1. In this embodiment, the object side surface and the image side surface of the first lens to the eighth lens are all aspherical surfaces.

[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] Fig.11 The axial chromatic aberration curve of the optical imaging device of the fourth embodiment is shown, which indicates the deviation of the focusing point of light of different wavelengths after passing through the optical imaging device. Fig.12 The astigmatism curve of the optical imaging device of Example 4 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Fig.13 The distortion curve of the optical imaging device of the fourth embodiment is shown, which represents 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 provided in the fourth embodiment can achieve good imaging quality.

[0114] Embodiment 5

[0115] like Fig. 9 As shown, the optical imaging device of the fifth embodiment of the present application is described, which differs from the fourth embodiment in that the distances and thicknesses between the various spacing elements, lenses, lens barrel P0, etc. are different.

[0116] Fig. 9 The schematic diagram of the structure of the optical imaging device of the fifth embodiment is shown. For the sake of brevity, some descriptions similar to those of the fourth embodiment are omitted. In this embodiment, the third lens and the fourth lens are not arranged to be snapped together, and the object side surface and the image side surface of the third spacer element are directly in contact with the third lens and the fourth lens, respectively, which improves the molding yield of the third lens and the fourth lens. In addition, the wall of the lens barrel is small, which is conducive to the miniaturization and lightweight of the optical imaging device.

[0117] Embodiment 6

[0118] like Fig.10 As shown, the optical imaging device of the sixth embodiment of the present application is described, which differs from the fourth embodiment in that the distances and thicknesses between the various spacing elements, lenses, lens barrel P0, etc. are different.

[0119] Fig.10 The structure diagram of the optical imaging device of the sixth embodiment is shown. For the sake of brevity, some descriptions similar to those of the fourth embodiment are omitted. In this embodiment, the overall thickness of the lens barrel is relatively small, which is conducive to the miniaturization and lightness of the optical imaging device.

[0120] Embodiment 7

[0121] like Fig.14 As shown, the optical imaging device of embodiment 7 of the present application is described. Fig.14 A schematic structural diagram of an optical imaging device of Embodiment 7 is shown.

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

[0123] In this embodiment, the first lens E1 has negative power, the object side surface S1 of the first lens is concave, and the image side surface S2 of the first lens is convex. The second lens E2 has negative power, the object side surface S3 of the second lens is convex, and the image side surface S4 of the second lens is concave. The third lens E3 has positive power, the object side surface S5 of the third lens is convex, and the image side surface S6 of the third lens is convex. The fourth lens E4 has negative power, the object side surface S7 of the fourth lens is concave, and the image side surface S8 of the fourth lens is convex. The fifth lens E5 has positive power, the object side surface S9 of the fifth lens is convex, and the image side surface S10 of the fifth lens is concave. The sixth lens E6 has positive power, the object side surface S11 of the sixth lens is convex, and the image side surface S12 of the sixth lens is concave. The seventh lens E7 has positive power, the object side surface S13 of the seventh lens is convex, and the image side surface S14 of the seventh lens is concave. The eighth lens E8 has positive focal power, the object side surface S15 of the eighth lens is concave, and the image side surface S16 of the eighth lens is convex. The optical imaging device also has a filter, and the filter has an object side surface S17 of the filter and an image side surface S18 of the filter. Light from the object passes through S1 to S18 to reach the imaging surface IMG. Table 6 shows the basic structural parameters of the optical imaging device of Example 7, wherein the units of the radius of curvature, thickness / distance, effective radius and focal length are all millimeters (mm).

[0124] Table 6

[0125]

[0126]

[0127] Table 7 shows the coefficients of the higher order terms that can be used for each aspheric mirror surface in the embodiment, wherein the surface shape of each aspheric surface can be defined by the formula (1) given in the above embodiment 1. In this embodiment, the object side surface and the image side surface of the first lens to the eighth lens are all aspheric surfaces.

[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] Fig.17 The axial chromatic aberration curve of the optical imaging device of the seventh embodiment is shown, which indicates the deviation of the focal point of light of different wavelengths after passing through the optical imaging device. Fig.18 The astigmatism curve of the optical imaging device of Example 7 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Fig.19 The distortion curve of the optical imaging device of Example 7 is shown, which represents the distortion magnitude values ​​corresponding to different field angles.

[0131] according to Figures 17 to 19 It can be seen that the optical imaging device provided in the seventh embodiment can achieve good imaging quality.

[0132] Embodiment 8

[0133] like Fig.15 As shown, an optical imaging device according to Embodiment 8 of the present application is described, which differs from Embodiment 7 in that the distances and thicknesses between the various spacing elements, lenses, lens barrel P0, etc. are different.

[0134] Fig.15 The structure diagram of the optical imaging device of the eighth embodiment is shown. For the sake of brevity, some descriptions similar to those of the seventh embodiment are omitted. In this embodiment, the aperture of the image side end of the lens barrel is smaller, which is conducive to the miniaturization of the optical imaging device.

[0135] Embodiment 9

[0136] like Fig.16 As shown, an optical imaging device according to Embodiment 9 of the present application is described, which differs from Embodiment 7 in that the distances and thicknesses between the various spacing elements, lenses, lens barrel P0, etc. are different.

[0137] Fig.16 FIG. 1 is a schematic diagram of the structure of the optical imaging device of Embodiment 9. For the sake of brevity, some descriptions similar to those of Embodiment 7 are omitted. In this embodiment, the apertures of the object side end and the image side end of the lens barrel are both small, further realizing the miniaturization and lightness of the optical imaging device.

[0138] In summary, embodiments 1 to 9 of the optical imaging device respectively satisfy the relationship 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 the lenses of the optical imaging devices of Examples 1 to 9, etc., 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 gives some structural parameters of the optical imaging devices of Examples 1 to 9, in units of 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 above-described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0148] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

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

[0150] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

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: A lens group, wherein the lens group comprises a first lens to an eighth lens arranged in sequence from the object side to the image side of the optical imaging device, the object side surface of the first lens is a concave surface, and the image side surface of the first lens is a convex surface; a spacer element group, the spacer element group at least comprising a first spacer element located between the first lens and the second lens and at least partially in contact with 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 in contact with 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 in contact with the image side surface of the third lens; A lens barrel, wherein the lens group and the spacer element group are accommodated in the lens barrel, and the inner annular surface of the lens barrel is stepped along the direction of the optical axis of the optical imaging device; Wherein, the half of the maximum field of view angle Semi-FOV of the optical imaging device and the numerical aperture FNO of the optical imaging device satisfy the following conditions: 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 surface 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。 2. The optical imaging device according to claim 1, characterized in that: 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 center thickness CT1 of the first lens on the optical axis satisfy the following: 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 face of the first spacer element along the direction of the optical axis, the curvature radius R1 of the object side face of the first lens, and the curvature radius R2 of the image side face of the first lens satisfy: -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 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 the following: 1.05<(DT11-d0s) / EPD<2.

3.

5. The optical imaging device according to claim 1, characterized in that: An inner diameter d1s of the object side surface of the first spacer element, an outer diameter D1s of the object side surface of the first spacer element, and an effective diameter DT12 of the image side surface of the first lens satisfy the following: 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 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.

7. The optical imaging device according to claim 1, characterized in that: The following relationship is satisfied among 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: 0 < (d1m - d2s) / CT2 < 0.

2.

8. The optical imaging device according to claim 1, characterized in that: The following relationship is satisfied among 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: -15 < f2 / (D2s - D1m) < -8.

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

6.

10. The optical imaging device according to claim 1, characterized in that: The following relationship is satisfied between 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: -0.2 < EP12 / f2 < -0.10; the following relationship is satisfied between 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: 0.1 < EP23 / f3 < 0.

2.

11. The optical imaging device according to any one of claims 1 to 10, characterized in that: The following relationship is satisfied among 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: 0.8 < (D3s - d3s) / DT32 < 2.

3.

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

4.

13. The optical imaging device according to any one of claims 1 to 10, characterized in that: The following relationship is satisfied between 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: 1.35 ≤ L / TD < 1.6.

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